$(TCLSH_CMD) $(TOP)/tool/vdbe-compress.tcl $(OPTS) <tsrc/vdbe.c >vdbe.new
	mv vdbe.new tsrc/vdbe.c
	cp fts5.c fts5.h tsrc
	touch .target_source

sqlite3.c:	.target_source $(TOP)/tool/mksqlite3c.tcl
	$(TCLSH_CMD) $(TOP)/tool/mksqlite3c.tcl
	cp tsrc/shell.c tsrc/sqlite3ext.h .
	cp $(TOP)/ext/session/sqlite3session.h .

sqlite3ext.h:	.target_source
	cp tsrc/sqlite3ext.h .

tclsqlite3.c:	sqlite3.c
	echo '#ifndef USE_SYSTEM_SQLITE' >tclsqlite3.c
................................................................................

sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(TEXE): sqlite3_analyzer.c
	$(LTLINK) sqlite3_analyzer.c -o $@ $(LIBTCL) $(TLIBS)

















dbdump$(TEXE): $(TOP)/ext/misc/dbdump.c sqlite3.lo
	$(LTLINK) -DDBDUMP_STANDALONE -o $@ \
           $(TOP)/ext/misc/dbdump.c sqlite3.lo $(TLIBS)

showdb$(TEXE):	$(TOP)/tool/showdb.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showdb.c sqlite3.lo $(TLIBS)

................................................................................

showjournal$(TEXE):	$(TOP)/tool/showjournal.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showjournal.c sqlite3.lo $(TLIBS)

showwal$(TEXE):	$(TOP)/tool/showwal.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showwal.c sqlite3.lo $(TLIBS)




changeset$(TEXE):	$(TOP)/ext/session/changeset.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/ext/session/changeset.c sqlite3.lo $(TLIBS)

rollback-test$(TEXE):	$(TOP)/tool/rollback-test.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/rollback-test.c sqlite3.lo $(TLIBS)

LogEst$(TEXE):	$(TOP)/tool/logest.c sqlite3.h

	$(TCLSH_CMD) $(TOP)/tool/vdbe-compress.tcl $(OPTS) <tsrc/vdbe.c >vdbe.new
	mv vdbe.new tsrc/vdbe.c
	cp fts5.c fts5.h tsrc
	touch .target_source

sqlite3.c:	.target_source $(TOP)/tool/mksqlite3c.tcl
	$(TCLSH_CMD) $(TOP)/tool/mksqlite3c.tcl
	cp tsrc/sqlite3ext.h .
	cp $(TOP)/ext/session/sqlite3session.h .

sqlite3ext.h:	.target_source
	cp tsrc/sqlite3ext.h .

tclsqlite3.c:	sqlite3.c
	echo '#ifndef USE_SYSTEM_SQLITE' >tclsqlite3.c
................................................................................

sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(TEXE): sqlite3_analyzer.c
	$(LTLINK) sqlite3_analyzer.c -o $@ $(LIBTCL) $(TLIBS)

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/ext/repair/sqlite3_checker.c.in >$@

sqlite3_checker$(TEXE):	sqlite3_checker.c
	$(LTLINK) sqlite3_checker.c -o $@ $(LIBTCL) $(TLIBS)

dbdump$(TEXE): $(TOP)/ext/misc/dbdump.c sqlite3.lo
	$(LTLINK) -DDBDUMP_STANDALONE -o $@ \
           $(TOP)/ext/misc/dbdump.c sqlite3.lo $(TLIBS)

showdb$(TEXE):	$(TOP)/tool/showdb.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showdb.c sqlite3.lo $(TLIBS)

................................................................................

showjournal$(TEXE):	$(TOP)/tool/showjournal.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showjournal.c sqlite3.lo $(TLIBS)

showwal$(TEXE):	$(TOP)/tool/showwal.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showwal.c sqlite3.lo $(TLIBS)

showshm$(TEXE):	$(TOP)/tool/showshm.c
	$(LTLINK) -o $@ $(TOP)/tool/showshm.c

changeset$(TEXE):	$(TOP)/ext/session/changeset.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/ext/session/changeset.c sqlite3.lo $(TLIBS)

rollback-test$(TEXE):	$(TOP)/tool/rollback-test.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/rollback-test.c sqlite3.lo $(TLIBS)

LogEst$(TEXE):	$(TOP)/tool/logest.c sqlite3.h

# executables needed for testing
#
TESTPROGS = \
  testfixture.exe \
  $(SQLITE3EXE) \
  sqlite3_analyzer.exe \

  sqldiff.exe \
  dbhash.exe

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)\test\fuzzdata1.db \
................................................................................
	del /Q tsrc\sqlite.h.in tsrc\parse.y 2>NUL
	$(TCLSH_CMD) $(TOP)\tool\vdbe-compress.tcl $(OPTS) < tsrc\vdbe.c > vdbe.new
	move vdbe.new tsrc\vdbe.c
	echo > .target_source

sqlite3.c:	.target_source sqlite3ext.h $(MKSQLITE3C_TOOL)
	$(TCLSH_CMD) $(MKSQLITE3C_TOOL) $(MKSQLITE3C_ARGS)
	copy tsrc\shell.c .
	copy $(TOP)\ext\session\sqlite3session.h .

sqlite3-all.c:	sqlite3.c $(TOP)\tool\split-sqlite3c.tcl
	$(TCLSH_CMD) $(TOP)\tool\split-sqlite3c.tcl
# <</mark>>

# Rule to build the amalgamation
................................................................................
sqlite3_analyzer.c:	$(SQLITE3C) $(SQLITE3H) $(TOP)\src\tclsqlite.c $(TOP)\tool\spaceanal.tcl $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in $(SQLITE_TCL_DEP)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in > $@

sqlite3_analyzer.exe:	sqlite3_analyzer.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_analyzer.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)


















dbdump.exe:	$(TOP)\ext\misc\dbdump.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DDBDUMP_STANDALONE $(TOP)\ext\misc\dbdump.c $(SQLITE3C) \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS)

testloadext.lo:	$(TOP)\src\test_loadext.c
	$(LTCOMPILE) $(NO_WARN) -c $(TOP)\src\test_loadext.c

................................................................................
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
		$(TOP)\tool\showjournal.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

showwal.exe:	$(TOP)\tool\showwal.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
		$(TOP)\tool\showwal.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)




changeset.exe:	$(TOP)\ext\session\changeset.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
		-DSQLITE_ENABLE_SESSION=1 -DSQLITE_ENABLE_PREUPDATE_HOOK=1 \
		$(TOP)\ext\session\changeset.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

fts3view.exe:	$(TOP)\ext\fts3\tool\fts3view.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \

# executables needed for testing
#
TESTPROGS = \
  testfixture.exe \
  $(SQLITE3EXE) \
  sqlite3_analyzer.exe \
  sqlite3_checker.exe \
  sqldiff.exe \
  dbhash.exe

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)\test\fuzzdata1.db \
................................................................................
	del /Q tsrc\sqlite.h.in tsrc\parse.y 2>NUL
	$(TCLSH_CMD) $(TOP)\tool\vdbe-compress.tcl $(OPTS) < tsrc\vdbe.c > vdbe.new
	move vdbe.new tsrc\vdbe.c
	echo > .target_source

sqlite3.c:	.target_source sqlite3ext.h $(MKSQLITE3C_TOOL)
	$(TCLSH_CMD) $(MKSQLITE3C_TOOL) $(MKSQLITE3C_ARGS)

	copy $(TOP)\ext\session\sqlite3session.h .

sqlite3-all.c:	sqlite3.c $(TOP)\tool\split-sqlite3c.tcl
	$(TCLSH_CMD) $(TOP)\tool\split-sqlite3c.tcl
# <</mark>>

# Rule to build the amalgamation
................................................................................
sqlite3_analyzer.c:	$(SQLITE3C) $(SQLITE3H) $(TOP)\src\tclsqlite.c $(TOP)\tool\spaceanal.tcl $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in $(SQLITE_TCL_DEP)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in > $@

sqlite3_analyzer.exe:	sqlite3_analyzer.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_analyzer.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\ext\repair\sqlite3_checker.c.in > $@

sqlite3_checker.exe:	sqlite3_checker.c $(LIBRESOBJS)
	$(LTLINK) $(NO_WARN) -DBUILD_sqlite -I$(TCLINCDIR) sqlite3_checker.c \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)

dbdump.exe:	$(TOP)\ext\misc\dbdump.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DDBDUMP_STANDALONE $(TOP)\ext\misc\dbdump.c $(SQLITE3C) \
		/link $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS)

testloadext.lo:	$(TOP)\src\test_loadext.c
	$(LTCOMPILE) $(NO_WARN) -c $(TOP)\src\test_loadext.c

................................................................................
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
		$(TOP)\tool\showjournal.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

showwal.exe:	$(TOP)\tool\showwal.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
		$(TOP)\tool\showwal.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

showshm.exe:	$(TOP)\tool\showshm.c
	$(LTLINK) $(NO_WARN)	$(TOP)\tool\showshm.c /link $(LDFLAGS) $(LTLINKOPTS)

changeset.exe:	$(TOP)\ext\session\changeset.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \
		-DSQLITE_ENABLE_SESSION=1 -DSQLITE_ENABLE_PREUPDATE_HOOK=1 \
		$(TOP)\ext\session\changeset.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

fts3view.exe:	$(TOP)\ext\fts3\tool\fts3view.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION \

3.21.0

3.22.0

libsqlite3_la_LDFLAGS = -no-undefined -version-info 8:6:8

bin_PROGRAMS = sqlite3
sqlite3_SOURCES = shell.c sqlite3.h
EXTRA_sqlite3_SOURCES = sqlite3.c
sqlite3_LDADD = @EXTRA_SHELL_OBJ@ @READLINE_LIBS@
sqlite3_DEPENDENCIES = @EXTRA_SHELL_OBJ@
sqlite3_CFLAGS = $(AM_CFLAGS) -DSQLITE_ENABLE_EXPLAIN_COMMENTS

include_HEADERS = sqlite3.h sqlite3ext.h

EXTRA_DIST = sqlite3.1 tea Makefile.msc sqlite3.rc README.txt Replace.cs
pkgconfigdir = ${libdir}/pkgconfig
pkgconfig_DATA = sqlite3.pc

man_MANS = sqlite3.1

libsqlite3_la_LDFLAGS = -no-undefined -version-info 8:6:8

bin_PROGRAMS = sqlite3
sqlite3_SOURCES = shell.c sqlite3.h
EXTRA_sqlite3_SOURCES = sqlite3.c
sqlite3_LDADD = @EXTRA_SHELL_OBJ@ @READLINE_LIBS@
sqlite3_DEPENDENCIES = @EXTRA_SHELL_OBJ@
sqlite3_CFLAGS = $(AM_CFLAGS) -DSQLITE_ENABLE_EXPLAIN_COMMENTS -DSQLITE_ENABLE_DBPAGE_VTAB -DSQLITE_ENABLE_STMTVTAB -DSQLITE_ENABLE_DBSTAT_VTAB

include_HEADERS = sqlite3.h sqlite3ext.h

EXTRA_DIST = sqlite3.1 tea Makefile.msc sqlite3.rc README.txt Replace.cs
pkgconfigdir = ${libdir}/pkgconfig
pkgconfig_DATA = sqlite3.pc

man_MANS = sqlite3.1

# Rule to build the Win32 resources object file.
#
!IF $(USE_RC)!=0
_HASHCHAR=^#
!IF ![echo !IFNDEF VERSION > rcver.vc] && \
    ![for /F "delims=" %V in ('type "$(SQLITE3H)" ^| find "$(_HASHCHAR)define SQLITE_VERSION "') do (echo VERSION = ^^%V >> rcver.vc)] && \
    ![echo !ENDIF >> rcver.vc]
!INCLUDE rcver.vc
!ENDIF

RESOURCE_VERSION = $(VERSION:^#=)
RESOURCE_VERSION = $(RESOURCE_VERSION:define=)
RESOURCE_VERSION = $(RESOURCE_VERSION:SQLITE_VERSION=)

# Rule to build the Win32 resources object file.
#
!IF $(USE_RC)!=0
_HASHCHAR=^#
!IF ![echo !IFNDEF VERSION > rcver.vc] && \
    ![for /F "delims=" %V in ('type "$(SQLITE3H)" ^| "%SystemRoot%\System32\find.exe" "$(_HASHCHAR)define SQLITE_VERSION "') do (echo VERSION = ^^%V >> rcver.vc)] && \
    ![echo !ENDIF >> rcver.vc]
!INCLUDE rcver.vc
!ENDIF

RESOURCE_VERSION = $(VERSION:^#=)
RESOURCE_VERSION = $(RESOURCE_VERSION:define=)
RESOURCE_VERSION = $(RESOURCE_VERSION:SQLITE_VERSION=)

#   --enable-static-shell
#   --enable-dynamic-extensions
#

AC_PREREQ(2.61)
AC_INIT(sqlite, --SQLITE-VERSION--, http://www.sqlite.org)
AC_CONFIG_SRCDIR([sqlite3.c])


# Use automake.
AM_INIT_AUTOMAKE([foreign])

AC_SYS_LARGEFILE

# Check for required programs.

#   --enable-static-shell
#   --enable-dynamic-extensions
#

AC_PREREQ(2.61)
AC_INIT(sqlite, --SQLITE-VERSION--, http://www.sqlite.org)
AC_CONFIG_SRCDIR([sqlite3.c])
AC_CONFIG_AUX_DIR([.])

# Use automake.
AM_INIT_AUTOMAKE([foreign])

AC_SYS_LARGEFILE

# Check for required programs.

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.69 for sqlite 3.21.0.
#
#
# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
#
#
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.
................................................................................
subdirs=
MFLAGS=
MAKEFLAGS=

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.21.0'
PACKAGE_STRING='sqlite 3.21.0'
PACKAGE_BUGREPORT=''
PACKAGE_URL=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H
................................................................................
#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.21.0 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.
................................................................................
  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.21.0:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
................................................................................
    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.21.0
generated by GNU Autoconf 2.69

Copyright (C) 2012 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit
................................................................................
  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno

} # ac_fn_c_check_header_mongrel
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.21.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{
................................................................................
test $as_write_fail = 0 && chmod +x $CONFIG_STATUS || ac_write_fail=1

cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
# Save the log message, to keep $0 and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.21.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@
................................................................................

Report bugs to the package provider."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
ac_cs_version="\\
sqlite config.status 3.21.0
configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

Copyright (C) 2012 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

#! /bin/sh
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.69 for sqlite 3.22.0.
#
#
# Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
#
#
# This configure script is free software; the Free Software Foundation
# gives unlimited permission to copy, distribute and modify it.
................................................................................
subdirs=
MFLAGS=
MAKEFLAGS=

# Identity of this package.
PACKAGE_NAME='sqlite'
PACKAGE_TARNAME='sqlite'
PACKAGE_VERSION='3.22.0'
PACKAGE_STRING='sqlite 3.22.0'
PACKAGE_BUGREPORT=''
PACKAGE_URL=''

# Factoring default headers for most tests.
ac_includes_default="\
#include <stdio.h>
#ifdef HAVE_SYS_TYPES_H
................................................................................
#
# Report the --help message.
#
if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
\`configure' configures sqlite 3.22.0 to adapt to many kinds of systems.

Usage: $0 [OPTION]... [VAR=VALUE]...

To assign environment variables (e.g., CC, CFLAGS...), specify them as
VAR=VALUE.  See below for descriptions of some of the useful variables.

Defaults for the options are specified in brackets.
................................................................................
  --build=BUILD     configure for building on BUILD [guessed]
  --host=HOST       cross-compile to build programs to run on HOST [BUILD]
_ACEOF
fi

if test -n "$ac_init_help"; then
  case $ac_init_help in
     short | recursive ) echo "Configuration of sqlite 3.22.0:";;
   esac
  cat <<\_ACEOF

Optional Features:
  --disable-option-checking  ignore unrecognized --enable/--with options
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
................................................................................
    cd "$ac_pwd" || { ac_status=$?; break; }
  done
fi

test -n "$ac_init_help" && exit $ac_status
if $ac_init_version; then
  cat <<\_ACEOF
sqlite configure 3.22.0
generated by GNU Autoconf 2.69

Copyright (C) 2012 Free Software Foundation, Inc.
This configure script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it.
_ACEOF
  exit
................................................................................
  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno

} # ac_fn_c_check_header_mongrel
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by sqlite $as_me 3.22.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@

_ACEOF
exec 5>>config.log
{
................................................................................
test $as_write_fail = 0 && chmod +x $CONFIG_STATUS || ac_write_fail=1

cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
# Save the log message, to keep $0 and so on meaningful, and to
# report actual input values of CONFIG_FILES etc. instead of their
# values after options handling.
ac_log="
This file was extended by sqlite $as_me 3.22.0, which was
generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
  CONFIG_HEADERS  = $CONFIG_HEADERS
  CONFIG_LINKS    = $CONFIG_LINKS
  CONFIG_COMMANDS = $CONFIG_COMMANDS
  $ $0 $@
................................................................................

Report bugs to the package provider."

_ACEOF
cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
ac_cs_version="\\
sqlite config.status 3.22.0
configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

Copyright (C) 2012 Free Software Foundation, Inc.
This config.status script is free software; the Free Software Foundation
gives unlimited permission to copy, distribute and modify it."

             $(LSMDIR)/lsm-test/lsmtest_main.c $(LSMDIR)/lsm-test/lsmtest_mem.c \
             $(LSMDIR)/lsm-test/lsmtest_tdb.c $(LSMDIR)/lsm-test/lsmtest_tdb3.c \
             $(LSMDIR)/lsm-test/lsmtest_util.c $(LSMDIR)/lsm-test/lsmtest_win32.c


# all: lsm.so

LSMOPTS += -DLSM_MUTEX_PTHREADS=1 -I$(LSMDIR)

lsm.so:	$(LSMOBJ)
	$(TCCX) -shared -o lsm.so $(LSMOBJ)

%.o:	$(LSMDIR)/%.c $(LSMHDR) sqlite3.h
	$(TCCX) $(LSMOPTS) -c $<
	
lsmtest$(EXE): $(LSMOBJ) $(LSMTESTSRC) $(LSMTESTHDR) sqlite3.o
	# $(TCPPX) -c $(TOP)/lsm-test/lsmtest_tdb2.cc
	$(TCCX) $(LSMOPTS) $(LSMTESTSRC) $(LSMOBJ) sqlite3.o -o lsmtest$(EXE) $(THREADLIB)

             $(LSMDIR)/lsm-test/lsmtest_main.c $(LSMDIR)/lsm-test/lsmtest_mem.c \
             $(LSMDIR)/lsm-test/lsmtest_tdb.c $(LSMDIR)/lsm-test/lsmtest_tdb3.c \
             $(LSMDIR)/lsm-test/lsmtest_util.c $(LSMDIR)/lsm-test/lsmtest_win32.c


# all: lsm.so

LSMOPTS += -DLSM_MUTEX_PTHREADS=1 -I$(LSMDIR) -DHAVE_ZLIB

lsm.so:	$(LSMOBJ)
	$(TCCX) -shared -o lsm.so $(LSMOBJ)

%.o:	$(LSMDIR)/%.c $(LSMHDR) sqlite3.h
	$(TCCX) $(LSMOPTS) -c $<
	
lsmtest$(EXE): $(LSMOBJ) $(LSMTESTSRC) $(LSMTESTHDR) sqlite3.o
	# $(TCPPX) -c $(TOP)/lsm-test/lsmtest_tdb2.cc
	$(TCCX) $(LSMOPTS) $(LSMTESTSRC) $(LSMOBJ) sqlite3.o -o lsmtest$(EXE) $(THREADLIB) -lz

*/
int lsmFsSortedPadding(
  FileSystem *pFS, 
  Snapshot *pSnapshot,
  Segment *pSeg
){
  int rc = LSM_OK;
  if( pFS->pCompress ){
    Pgno iLast2;
    Pgno iLast = pSeg->iLastPg;     /* Current last page of segment */
    int nPad;                       /* Bytes of padding required */
    u8 aSz[3];

    iLast2 = (1 + iLast/pFS->szSector) * pFS->szSector - 1;
    assert( fsPageToBlock(pFS, iLast)==fsPageToBlock(pFS, iLast2) );

*/
int lsmFsSortedPadding(
  FileSystem *pFS, 
  Snapshot *pSnapshot,
  Segment *pSeg
){
  int rc = LSM_OK;
  if( pFS->pCompress && pSeg->iFirst ){
    Pgno iLast2;
    Pgno iLast = pSeg->iLastPg;     /* Current last page of segment */
    int nPad;                       /* Bytes of padding required */
    u8 aSz[3];

    iLast2 = (1 + iLast/pFS->szSector) * pFS->szSector - 1;
    assert( fsPageToBlock(pFS, iLast)==fsPageToBlock(pFS, iLast2) );

  const int nUsMax = 100000;      /* Max value for nUs */
  int nUs = 1000;                 /* us to wait between DMS1 attempts */
  int rc;

  /* Obtain a pointer to the shared-memory header */
  assert( pDb->pShmhdr==0 );
  assert( pDb->bReadonly==0 );
  rc = lsmShmCacheChunks(pDb, 1);
  if( rc!=LSM_OK ) return rc;
  pDb->pShmhdr = (ShmHeader *)pDb->apShm[0];

  /* Block for an exclusive lock on DMS1. This lock serializes all calls
  ** to doDbConnect() and doDbDisconnect() across all processes.  */
  while( 1 ){
    rc = lsmShmLock(pDb, LSM_LOCK_DMS1, LSM_LOCK_EXCL, 1);
    if( rc!=LSM_BUSY ) break;
    lsmEnvSleep(pDb->pEnv, nUs);
    nUs = nUs * 2;
    if( nUs>nUsMax ) nUs = nUsMax;
  }
  if( rc!=LSM_OK ){
    pDb->pShmhdr = 0;
    return rc;
  }



  /* Try an exclusive lock on DMS2/DMS3. If successful, this is the first 
  ** and only connection to the database. In this case initialize the 
  ** shared-memory and run log file recovery.  */
  assert( LSM_LOCK_DMS3==1+LSM_LOCK_DMS2 );
  rc = lsmShmTestLock(pDb, LSM_LOCK_DMS2, 2, LSM_LOCK_EXCL);
  if( rc==LSM_OK ){
................................................................................
    rc = lsmFsOpen(pDb, zName, p->bReadonly);
  }

  /* If the db handle is read-write, then connect to the system now. Run
  ** recovery as necessary. Or, if this is a read-only database handle,
  ** defer attempting to connect to the system until a read-transaction
  ** is opened.  */
  if( pDb->bReadonly==0 ){
    if( rc==LSM_OK ){
      rc = lsmFsConfigure(pDb);
    }
    if( rc==LSM_OK ){
      rc = doDbConnect(pDb);
    }
  }

  return rc;
}

static void dbDeferClose(lsm_db *pDb){
  if( pDb->pFS ){

  const int nUsMax = 100000;      /* Max value for nUs */
  int nUs = 1000;                 /* us to wait between DMS1 attempts */
  int rc;

  /* Obtain a pointer to the shared-memory header */
  assert( pDb->pShmhdr==0 );
  assert( pDb->bReadonly==0 );




  /* Block for an exclusive lock on DMS1. This lock serializes all calls
  ** to doDbConnect() and doDbDisconnect() across all processes.  */
  while( 1 ){
    rc = lsmShmLock(pDb, LSM_LOCK_DMS1, LSM_LOCK_EXCL, 1);
    if( rc!=LSM_BUSY ) break;
    lsmEnvSleep(pDb->pEnv, nUs);
    nUs = nUs * 2;
    if( nUs>nUsMax ) nUs = nUsMax;
  }
  if( rc==LSM_OK ){
    rc = lsmShmCacheChunks(pDb, 1);

  }
  if( rc!=LSM_OK ) return rc;
  pDb->pShmhdr = (ShmHeader *)pDb->apShm[0];

  /* Try an exclusive lock on DMS2/DMS3. If successful, this is the first 
  ** and only connection to the database. In this case initialize the 
  ** shared-memory and run log file recovery.  */
  assert( LSM_LOCK_DMS3==1+LSM_LOCK_DMS2 );
  rc = lsmShmTestLock(pDb, LSM_LOCK_DMS2, 2, LSM_LOCK_EXCL);
  if( rc==LSM_OK ){
................................................................................
    rc = lsmFsOpen(pDb, zName, p->bReadonly);
  }

  /* If the db handle is read-write, then connect to the system now. Run
  ** recovery as necessary. Or, if this is a read-only database handle,
  ** defer attempting to connect to the system until a read-transaction
  ** is opened.  */

  if( rc==LSM_OK ){
    rc = lsmFsConfigure(pDb);
  }
  if( rc==LSM_OK && pDb->bReadonly==0 ){
    rc = doDbConnect(pDb);

  }

  return rc;
}

static void dbDeferClose(lsm_db *pDb){
  if( pDb->pFS ){

/*
** 2017-10-24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains an implementation of the "sqlite_btreeinfo" virtual table.
**
** The sqlite_btreeinfo virtual table is a read-only eponymous-only virtual
** table that shows information about all btrees in an SQLite database file.
** The schema is like this:
**
** CREATE TABLE sqlite_btreeinfo(
**    type TEXT,                   -- "table" or "index"
**    name TEXT,                   -- Name of table or index for this btree.
**    tbl_name TEXT,               -- Associated table
**    rootpage INT,                -- The root page of the btree
**    sql TEXT,                    -- SQL for this btree - from sqlite_master
**    hasRowid BOOLEAN,            -- True if the btree has a rowid
**    nEntry INT,                  -- Estimated number of enteries
**    nPage INT,                   -- Estimated number of pages
**    depth INT,                   -- Depth of the btree
**    szPage INT,                  -- Size of each page in bytes
**    zSchema TEXT HIDDEN          -- The schema to which this btree belongs
** );
**
** The first 5 fields are taken directly from the sqlite_master table.
** Considering only the first 5 fields, the only difference between 
** this virtual table and the sqlite_master table is that this virtual
** table omits all entries that have a 0 or NULL rowid - in other words
** it omits triggers and views.
**
** The value added by this table comes in the next 5 fields.
**
** Note that nEntry and nPage are *estimated*.  They are computed doing
** a single search from the root to a leaf, counting the number of cells
** at each level, and assuming that unvisited pages have a similar number
** of cells.
**
** The sqlite_dbpage virtual table must be available for this virtual table
** to operate.
**
** USAGE EXAMPLES:
**
** Show the table btrees in a schema order with the tables with the most
** rows occuring first:
**
**      SELECT name, nEntry
**        FROM sqlite_btreeinfo
**       WHERE type='table'
**       ORDER BY nEntry DESC, name;
**
** Show the names of all WITHOUT ROWID tables: 
**
**      SELECT name FROM sqlite_btreeinfo
**       WHERE type='table' AND NOT hasRowid;
*/
#if !defined(SQLITEINT_H)
#include "sqlite3ext.h"
#endif
SQLITE_EXTENSION_INIT1
#include <string.h>
#include <assert.h>

/* Columns available in this virtual table */
#define BINFO_COLUMN_TYPE         0
#define BINFO_COLUMN_NAME         1
#define BINFO_COLUMN_TBL_NAME     2
#define BINFO_COLUMN_ROOTPAGE     3
#define BINFO_COLUMN_SQL          4
#define BINFO_COLUMN_HASROWID     5
#define BINFO_COLUMN_NENTRY       6
#define BINFO_COLUMN_NPAGE        7
#define BINFO_COLUMN_DEPTH        8
#define BINFO_COLUMN_SZPAGE       9
#define BINFO_COLUMN_SCHEMA      10

/* Forward declarations */
typedef struct BinfoTable BinfoTable;
typedef struct BinfoCursor BinfoCursor;

/* A cursor for the sqlite_btreeinfo table */
struct BinfoCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_stmt *pStmt;            /* Query against sqlite_master */
  int rc;                         /* Result of previous sqlite_step() call */
  int hasRowid;                   /* hasRowid value.  Negative if unknown. */
  sqlite3_int64 nEntry;           /* nEntry value */
  int nPage;                      /* nPage value */
  int depth;                      /* depth value */
  int szPage;                     /* size of a btree page.  0 if unknown */
  char *zSchema;                  /* Schema being interrogated */
};

/* The sqlite_btreeinfo table */
struct BinfoTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The databse connection */
};

/*
** Connect to the sqlite_btreeinfo virtual table.
*/
static int binfoConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  BinfoTable *pTab = 0;
  int rc = SQLITE_OK;
  rc = sqlite3_declare_vtab(db, 
      "CREATE TABLE x(\n"
      " type TEXT,\n"
      " name TEXT,\n"
      " tbl_name TEXT,\n"
      " rootpage INT,\n"
      " sql TEXT,\n"
      " hasRowid BOOLEAN,\n"
      " nEntry INT,\n"
      " nPage INT,\n"
      " depth INT,\n"
      " szPage INT,\n"
      " zSchema TEXT HIDDEN\n"
      ")");
  if( rc==SQLITE_OK ){
    pTab = (BinfoTable *)sqlite3_malloc64(sizeof(BinfoTable));
    if( pTab==0 ) rc = SQLITE_NOMEM;
  }
  assert( rc==SQLITE_OK || pTab==0 );
  if( pTab ){
    pTab->db = db;
  }
  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
** Disconnect from or destroy a btreeinfo virtual table.
*/
static int binfoDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** idxNum:
**
**     0     Use "main" for the schema
**     1     Schema identified by parameter ?1
*/
static int binfoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int i;
  pIdxInfo->estimatedCost = 10000.0;  /* Cost estimate */
  pIdxInfo->estimatedRows = 100;
  for(i=0; i<pIdxInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
    if( p->usable
     && p->iColumn==BINFO_COLUMN_SCHEMA
     && p->op==SQLITE_INDEX_CONSTRAINT_EQ
    ){
      pIdxInfo->estimatedCost = 1000.0;
      pIdxInfo->idxNum = 1;
      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
      pIdxInfo->aConstraintUsage[i].omit = 1;
      break;
    }
  }
  return SQLITE_OK;
}

/*
** Open a new btreeinfo cursor.
*/
static int binfoOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  BinfoCursor *pCsr;

  pCsr = (BinfoCursor *)sqlite3_malloc64(sizeof(BinfoCursor));
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }else{
    memset(pCsr, 0, sizeof(BinfoCursor));
    pCsr->base.pVtab = pVTab;
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

/*
** Close a btreeinfo cursor.
*/
static int binfoClose(sqlite3_vtab_cursor *pCursor){
  BinfoCursor *pCsr = (BinfoCursor *)pCursor;
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->zSchema);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Move a btreeinfo cursor to the next entry in the file.
*/
static int binfoNext(sqlite3_vtab_cursor *pCursor){
  BinfoCursor *pCsr = (BinfoCursor *)pCursor;
  pCsr->rc = sqlite3_step(pCsr->pStmt);
  pCsr->hasRowid = -1;
  return pCsr->rc==SQLITE_ERROR ? SQLITE_ERROR : SQLITE_OK;
}

/* We have reached EOF if previous sqlite3_step() returned
** anything other than SQLITE_ROW;
*/
static int binfoEof(sqlite3_vtab_cursor *pCursor){
  BinfoCursor *pCsr = (BinfoCursor *)pCursor;
  return pCsr->rc!=SQLITE_ROW;
}

/* Position a cursor back to the beginning.
*/
static int binfoFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  BinfoCursor *pCsr = (BinfoCursor *)pCursor;
  BinfoTable *pTab = (BinfoTable *)pCursor->pVtab;
  char *zSql;
  int rc;

  sqlite3_free(pCsr->zSchema);
  if( idxNum==1 && sqlite3_value_type(argv[0])!=SQLITE_NULL ){
    pCsr->zSchema = sqlite3_mprintf("%s", sqlite3_value_text(argv[0]));
  }else{
    pCsr->zSchema = sqlite3_mprintf("main");
  }
  zSql = sqlite3_mprintf(
      "SELECT 0, 'table','sqlite_master','sqlite_master',1,NULL "
      "UNION ALL "
      "SELECT rowid, type, name, tbl_name, rootpage, sql"
      " FROM \"%w\".sqlite_master WHERE rootpage>=1",
       pCsr->zSchema);
  sqlite3_finalize(pCsr->pStmt);
  pCsr->pStmt = 0;
  pCsr->hasRowid = -1;
  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
  sqlite3_free(zSql);
  if( rc==SQLITE_OK ){
    rc = binfoNext(pCursor);
  }
  return rc;
}

/* Decode big-endian integers */
static unsigned int get_uint16(unsigned char *a){
  return (a[0]<<8)|a[1];
}
static unsigned int get_uint32(unsigned char *a){
  return (a[0]<<24)|(a[1]<<16)|(a[2]<<8)|a[3];
}

/* Examine the b-tree rooted at pgno and estimate its size.
** Return non-zero if anything goes wrong.
*/
static int binfoCompute(sqlite3 *db, int pgno, BinfoCursor *pCsr){
  sqlite3_int64 nEntry = 1;
  int nPage = 1;
  unsigned char *aData;
  sqlite3_stmt *pStmt = 0;
  int rc = SQLITE_OK;
  int pgsz = 0;
  int nCell;
  int iCell;

  rc = sqlite3_prepare_v2(db, 
           "SELECT data FROM sqlite_dbpage('main') WHERE pgno=?1", -1,
           &pStmt, 0);
  if( rc ) return rc;
  pCsr->depth = 1;
  while(1){
    sqlite3_bind_int(pStmt, 1, pgno);
    rc = sqlite3_step(pStmt);
    if( rc!=SQLITE_ROW ){
      rc = SQLITE_ERROR;
      break;
    }
    pCsr->szPage = pgsz = sqlite3_column_bytes(pStmt, 0);
    aData = (unsigned char*)sqlite3_column_blob(pStmt, 0);
    if( aData==0 ){    
      rc = SQLITE_NOMEM;
      break;
    }
    if( pgno==1 ){
      aData += 100;
      pgsz -= 100;
    }
    pCsr->hasRowid = aData[0]!=2 && aData[0]!=10;
    nCell = get_uint16(aData+3);
    nEntry *= (nCell+1);
    if( aData[0]==10 || aData[0]==13 ) break;
    nPage *= (nCell+1);
    if( nCell<=1 ){
      pgno = get_uint32(aData+8);
    }else{
      iCell = get_uint16(aData+12+2*(nCell/2));
      if( pgno==1 ) iCell -= 100;
      if( iCell<=12 || iCell>=pgsz-4 ){
        rc = SQLITE_CORRUPT;
        break;
      }
      pgno = get_uint32(aData+iCell);
    }
    pCsr->depth++;
    sqlite3_reset(pStmt);
  }
  sqlite3_finalize(pStmt);
  pCsr->nPage = nPage;
  pCsr->nEntry = nEntry;
  if( rc==SQLITE_ROW ) rc = SQLITE_OK;
  return rc;
}

/* Return a column for the sqlite_btreeinfo table */
static int binfoColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  BinfoCursor *pCsr = (BinfoCursor *)pCursor;
  if( i>=BINFO_COLUMN_HASROWID && i<=BINFO_COLUMN_SZPAGE && pCsr->hasRowid<0 ){
    int pgno = sqlite3_column_int(pCsr->pStmt, BINFO_COLUMN_ROOTPAGE+1);
    sqlite3 *db = sqlite3_context_db_handle(ctx);
    int rc = binfoCompute(db, pgno, pCsr);
    if( rc ){
      return rc;
    }
  }
  switch( i ){
    case BINFO_COLUMN_NAME:
    case BINFO_COLUMN_TYPE:
    case BINFO_COLUMN_TBL_NAME:
    case BINFO_COLUMN_ROOTPAGE:
    case BINFO_COLUMN_SQL: {
      sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pStmt, i+1));
      break;
    }
    case BINFO_COLUMN_HASROWID: {
      sqlite3_result_int(ctx, pCsr->hasRowid);
      break;
    }
    case BINFO_COLUMN_NENTRY: {
      sqlite3_result_int64(ctx, pCsr->nEntry);
      break;
    }
    case BINFO_COLUMN_NPAGE: {
      sqlite3_result_int(ctx, pCsr->nPage);
      break;
    }
    case BINFO_COLUMN_DEPTH: {
      sqlite3_result_int(ctx, pCsr->depth);
      break;
    }
    case BINFO_COLUMN_SCHEMA: {
      sqlite3_result_text(ctx, pCsr->zSchema, -1, SQLITE_STATIC);
      break;
    }
  }
  return SQLITE_OK;
}

/* Return the ROWID for the sqlite_btreeinfo table */
static int binfoRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  BinfoCursor *pCsr = (BinfoCursor *)pCursor;
  *pRowid = sqlite3_column_int64(pCsr->pStmt, 0);
  return SQLITE_OK;
}

/*
** Invoke this routine to register the "sqlite_btreeinfo" virtual table module
*/
int sqlite3BinfoRegister(sqlite3 *db){
  static sqlite3_module binfo_module = {
    0,                           /* iVersion */
    0,                           /* xCreate */
    binfoConnect,                /* xConnect */
    binfoBestIndex,              /* xBestIndex */
    binfoDisconnect,             /* xDisconnect */
    0,                           /* xDestroy */
    binfoOpen,                   /* xOpen - open a cursor */
    binfoClose,                  /* xClose - close a cursor */
    binfoFilter,                 /* xFilter - configure scan constraints */
    binfoNext,                   /* xNext - advance a cursor */
    binfoEof,                    /* xEof - check for end of scan */
    binfoColumn,                 /* xColumn - read data */
    binfoRowid,                  /* xRowid - read data */
    0,                           /* xUpdate */
    0,                           /* xBegin */
    0,                           /* xSync */
    0,                           /* xCommit */
    0,                           /* xRollback */
    0,                           /* xFindMethod */
    0,                           /* xRename */
    0,                           /* xSavepoint */
    0,                           /* xRelease */
    0,                           /* xRollbackTo */
  };
  return sqlite3_create_module(db, "sqlite_btreeinfo", &binfo_module, 0);
}

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_btreeinfo_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return sqlite3BinfoRegister(db);
}

*/
static int editDist3Install(sqlite3 *db){
  int rc;
  EditDist3Config *pConfig = sqlite3_malloc64( sizeof(*pConfig) );
  if( pConfig==0 ) return SQLITE_NOMEM;
  memset(pConfig, 0, sizeof(*pConfig));
  rc = sqlite3_create_function_v2(db, "editdist3",

              2, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function_v2(db, "editdist3",

                3, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function_v2(db, "editdist3",
                1, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0,
                editDist3ConfigDelete);
  }else{
    sqlite3_free(pConfig);
  }
  return rc;
}
/* End configurable cost unicode edit distance routines
******************************************************************************
................................................................................

/*
** Register the various functions and the virtual table.
*/
static int spellfix1Register(sqlite3 *db){
  int rc = SQLITE_OK;
  int i;
  rc = sqlite3_create_function(db, "spellfix1_translit", 1, SQLITE_UTF8, 0,

                                  transliterateSqlFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_editdist", 2, SQLITE_UTF8, 0,

                                  editdistSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_phonehash", 1, SQLITE_UTF8, 0,

                                  phoneticHashSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_scriptcode", 1, SQLITE_UTF8, 0,

                                  scriptCodeSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0);
  }
  if( rc==SQLITE_OK ){
    rc = editDist3Install(db);

*/
static int editDist3Install(sqlite3 *db){
  int rc;
  EditDist3Config *pConfig = sqlite3_malloc64( sizeof(*pConfig) );
  if( pConfig==0 ) return SQLITE_NOMEM;
  memset(pConfig, 0, sizeof(*pConfig));
  rc = sqlite3_create_function_v2(db, "editdist3",
              2, SQLITE_UTF8|SQLITE_DETERMINISTIC, pConfig,
              editDist3SqlFunc, 0, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function_v2(db, "editdist3",
                3, SQLITE_UTF8|SQLITE_DETERMINISTIC, pConfig,
                editDist3SqlFunc, 0, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function_v2(db, "editdist3",
                1, SQLITE_UTF8|SQLITE_DETERMINISTIC, pConfig,
                editDist3SqlFunc, 0, 0, editDist3ConfigDelete);
  }else{
    sqlite3_free(pConfig);
  }
  return rc;
}
/* End configurable cost unicode edit distance routines
******************************************************************************
................................................................................

/*
** Register the various functions and the virtual table.
*/
static int spellfix1Register(sqlite3 *db){
  int rc = SQLITE_OK;
  int i;
  rc = sqlite3_create_function(db, "spellfix1_translit", 1,
                               SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                transliterateSqlFunc, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_editdist", 2,
                                 SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                  editdistSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_phonehash", 1,
                                 SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                  phoneticHashSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "spellfix1_scriptcode", 1,
                                  SQLITE_UTF8|SQLITE_DETERMINISTIC, 0,
                                  scriptCodeSqlFunc, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0);
  }
  if( rc==SQLITE_OK ){
    rc = editDist3Install(db);

  rc = sqlite3_prepare_v2(db, zTrunk, -1, &pTrunk, 0);
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_bind_text(pTrunk, 1, zDb, -1, SQLITE_STATIC);
  while( rc==SQLITE_OK && sqlite3_step(pTrunk)==SQLITE_ROW ){
    u32 i;
    u32 iTrunk = (u32)sqlite3_column_int(pTrunk, 0);
    const u8 *aData = (const u8*)sqlite3_column_blob(pTrunk, 1);
    int nData = sqlite3_column_bytes(pTrunk, 1);
    u32 iNext = get4byte(&aData[0]);
    u32 nLeaf = get4byte(&aData[4]);

    if( nLeaf>((nData/4)-2-6) ){
      rc = checkFreelistError(pzOut, 
          "leaf count out of range (%d) on trunk page %d", 
          (int)nLeaf, (int)iTrunk

  rc = sqlite3_prepare_v2(db, zTrunk, -1, &pTrunk, 0);
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_bind_text(pTrunk, 1, zDb, -1, SQLITE_STATIC);
  while( rc==SQLITE_OK && sqlite3_step(pTrunk)==SQLITE_ROW ){
    u32 i;
    u32 iTrunk = (u32)sqlite3_column_int(pTrunk, 0);
    const u8 *aData = (const u8*)sqlite3_column_blob(pTrunk, 1);
    u32 nData = (u32)sqlite3_column_bytes(pTrunk, 1);
    u32 iNext = get4byte(&aData[0]);
    u32 nLeaf = get4byte(&aData[4]);

    if( nLeaf>((nData/4)-2-6) ){
      rc = checkFreelistError(pzOut, 
          "leaf count out of range (%d) on trunk page %d", 
          (int)nLeaf, (int)iTrunk

/*
** 2017 October 27
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
*/

#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1

/*
** Stuff that is available inside the amalgamation, but which we need to
** declare ourselves if this module is compiled separately.
*/
#ifndef SQLITE_AMALGAMATION
# include <string.h>
# include <stdio.h>
# include <stdlib.h>
# include <assert.h>
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
#define get4byte(x) (        \
    ((u32)((x)[0])<<24) +    \
    ((u32)((x)[1])<<16) +    \
    ((u32)((x)[2])<<8) +     \
    ((u32)((x)[3]))          \
)
#endif

typedef struct CidxTable CidxTable;
typedef struct CidxCursor CidxCursor;

struct CidxTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;
};

struct CidxCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_int64 iRowid;           /* Row number of the output */
  char *zIdxName;                 /* Copy of the index_name parameter */
  char *zAfterKey;                /* Copy of the after_key parameter */
  sqlite3_stmt *pStmt;            /* SQL statement that generates the output */
};

typedef struct CidxColumn CidxColumn;
struct CidxColumn {
  char *zExpr;                    /* Text for indexed expression */
  int bDesc;                      /* True for DESC columns, otherwise false */
  int bKey;                       /* Part of index, not PK */
};

typedef struct CidxIndex CidxIndex;
struct CidxIndex {
  char *zWhere;                   /* WHERE clause, if any */
  int nCol;                       /* Elements in aCol[] array */
  CidxColumn aCol[1];             /* Array of indexed columns */
};

static void *cidxMalloc(int *pRc, int n){
  void *pRet = 0;
  assert( n!=0 );
  if( *pRc==SQLITE_OK ){
    pRet = sqlite3_malloc(n);
    if( pRet ){
      memset(pRet, 0, n);
    }else{
      *pRc = SQLITE_NOMEM;
    }
  }
  return pRet;
}

static void cidxCursorError(CidxCursor *pCsr, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  assert( pCsr->base.pVtab->zErrMsg==0 );
  pCsr->base.pVtab->zErrMsg = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
}

/*
** Connect to the incremental_index_check virtual table.
*/
static int cidxConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  int rc = SQLITE_OK;
  CidxTable *pRet;

#define IIC_ERRMSG        0
#define IIC_CURRENT_KEY   1
#define IIC_INDEX_NAME    2
#define IIC_AFTER_KEY     3
#define IIC_SCANNER_SQL   4
  rc = sqlite3_declare_vtab(db,
      "CREATE TABLE xyz("
      " errmsg TEXT,"            /* Error message or NULL if everything is ok */
      " current_key TEXT,"       /* SQLite quote() text of key values */
      " index_name HIDDEN,"      /* IN: name of the index being scanned */
      " after_key HIDDEN,"       /* IN: Start scanning after this key */
      " scanner_sql HIDDEN"      /* debuggingn info: SQL used for scanner */
      ")"
  );
  pRet = cidxMalloc(&rc, sizeof(CidxTable));
  if( pRet ){
    pRet->db = db;
  }

  *ppVtab = (sqlite3_vtab*)pRet;
  return rc;
}

/*
** Disconnect from or destroy an incremental_index_check virtual table.
*/
static int cidxDisconnect(sqlite3_vtab *pVtab){
  CidxTable *pTab = (CidxTable*)pVtab;
  sqlite3_free(pTab);
  return SQLITE_OK;
}

/*
** idxNum and idxStr are not used.  There are only three possible plans,
** which are all distinguished by the number of parameters.
**
**   No parameters:         A degenerate plan.  The result is zero rows.
**   1 Parameter:           Scan all of the index starting with first entry
**   2 parameters:          Scan the index starting after the "after_key".    
**
** Provide successively smaller costs for each of these plans to encourage
** the query planner to select the one with the most parameters.
*/
static int cidxBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pInfo){
  int iIdxName = -1;
  int iAfterKey = -1;
  int i;

  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pInfo->aConstraint[i];
    if( p->usable==0 ) continue;
    if( p->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;

    if( p->iColumn==IIC_INDEX_NAME ){
      iIdxName = i;
    }
    if( p->iColumn==IIC_AFTER_KEY ){
      iAfterKey = i;
    }
  }

  if( iIdxName<0 ){
    pInfo->estimatedCost = 1000000000.0;
  }else{
    pInfo->aConstraintUsage[iIdxName].argvIndex = 1;
    pInfo->aConstraintUsage[iIdxName].omit = 1;
    if( iAfterKey<0 ){
      pInfo->estimatedCost = 1000000.0;
    }else{
      pInfo->aConstraintUsage[iAfterKey].argvIndex = 2;
      pInfo->aConstraintUsage[iAfterKey].omit = 1;
      pInfo->estimatedCost = 1000.0;
    }
  }

  return SQLITE_OK;
}

/*
** Open a new btreeinfo cursor.
*/
static int cidxOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  CidxCursor *pRet;
  int rc = SQLITE_OK;

  pRet = cidxMalloc(&rc, sizeof(CidxCursor));

  *ppCursor = (sqlite3_vtab_cursor*)pRet;
  return rc;
}

/*
** Close a btreeinfo cursor.
*/
static int cidxClose(sqlite3_vtab_cursor *pCursor){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->zIdxName);
  sqlite3_free(pCsr->zAfterKey);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Move a btreeinfo cursor to the next entry in the file.
*/
static int cidxNext(sqlite3_vtab_cursor *pCursor){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  int rc = sqlite3_step(pCsr->pStmt);
  if( rc!=SQLITE_ROW ){
    rc = sqlite3_finalize(pCsr->pStmt);
    pCsr->pStmt = 0;
    if( rc!=SQLITE_OK ){
      sqlite3 *db = ((CidxTable*)pCsr->base.pVtab)->db;
      cidxCursorError(pCsr, "Cursor error: %s", sqlite3_errmsg(db));
    }
  }else{
    pCsr->iRowid++;
    rc = SQLITE_OK;
  }
  return rc;
}

/* We have reached EOF if previous sqlite3_step() returned
** anything other than SQLITE_ROW;
*/
static int cidxEof(sqlite3_vtab_cursor *pCursor){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  return pCsr->pStmt==0;
}

static char *cidxMprintf(int *pRc, const char *zFmt, ...){
  char *zRet = 0;
  va_list ap;
  va_start(ap, zFmt);
  zRet = sqlite3_vmprintf(zFmt, ap);
  if( *pRc==SQLITE_OK ){
    if( zRet==0 ){
      *pRc = SQLITE_NOMEM;
    }
  }else{
    sqlite3_free(zRet);
    zRet = 0;
  }
  va_end(ap);
  return zRet;
}

static sqlite3_stmt *cidxPrepare(
  int *pRc, CidxCursor *pCsr, const char *zFmt, ...
){
  sqlite3_stmt *pRet = 0;
  char *zSql;
  va_list ap;                     /* ... printf arguments */
  va_start(ap, zFmt);

  zSql = sqlite3_vmprintf(zFmt, ap);
  if( *pRc==SQLITE_OK ){
    if( zSql==0 ){
      *pRc = SQLITE_NOMEM;
    }else{
      sqlite3 *db = ((CidxTable*)pCsr->base.pVtab)->db;
      *pRc = sqlite3_prepare_v2(db, zSql, -1, &pRet, 0);
      if( *pRc!=SQLITE_OK ){
        cidxCursorError(pCsr, "SQL error: %s", sqlite3_errmsg(db));
      }
    }
  }
  sqlite3_free(zSql);
  va_end(ap);

  return pRet;
}

static void cidxFinalize(int *pRc, sqlite3_stmt *pStmt){
  int rc = sqlite3_finalize(pStmt);
  if( *pRc==SQLITE_OK ) *pRc = rc;
}

char *cidxStrdup(int *pRc, const char *zStr){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    int n = (int)strlen(zStr);
    zRet = cidxMalloc(pRc, n+1);
    if( zRet ) memcpy(zRet, zStr, n+1);
  }
  return zRet;
}

static void cidxFreeIndex(CidxIndex *pIdx){
  if( pIdx ){
    int i;
    for(i=0; i<pIdx->nCol; i++){
      sqlite3_free(pIdx->aCol[i].zExpr);
    }
    sqlite3_free(pIdx->zWhere);
    sqlite3_free(pIdx);
  }
}

static int cidx_isspace(char c){
  return c==' ' || c=='\t' || c=='\r' || c=='\n';
}

static int cidx_isident(char c){
  return c<0 
    || (c>='0' && c<='9') || (c>='a' && c<='z') 
    || (c>='A' && c<='Z') || c=='_';
}

#define CIDX_PARSE_EOF   0
#define CIDX_PARSE_COMMA 1      /*  "," */
#define CIDX_PARSE_OPEN  2      /*  "(" */
#define CIDX_PARSE_CLOSE 3      /*  ")" */

/*
** Argument zIn points into the start, middle or end of a CREATE INDEX
** statement. If argument pbDoNotTrim is non-NULL, then this function
** scans the input until it finds EOF, a comma (",") or an open or
** close parenthesis character. It then sets (*pzOut) to point to said
** character and returns a CIDX_PARSE_XXX constant as appropriate. The
** parser is smart enough that special characters inside SQL strings
** or comments are not returned for.
**
** Or, if argument pbDoNotTrim is NULL, then this function sets *pzOut
** to point to the first character of the string that is not whitespace
** or part of an SQL comment and returns CIDX_PARSE_EOF.
**
** Additionally, if pbDoNotTrim is not NULL and the element immediately
** before (*pzOut) is an SQL comment of the form "-- comment", then
** (*pbDoNotTrim) is set before returning. In all other cases it is
** cleared.
*/
static int cidxFindNext(
  const char *zIn, 
  const char **pzOut,
  int *pbDoNotTrim                /* OUT: True if prev is -- comment */
){
  const char *z = zIn;

  while( 1 ){
    while( cidx_isspace(*z) ) z++;
    if( z[0]=='-' && z[1]=='-' ){
      z += 2;
      while( z[0]!='\n' ){
        if( z[0]=='\0' ) return CIDX_PARSE_EOF;
        z++;
      }
      while( cidx_isspace(*z) ) z++;
      if( pbDoNotTrim ) *pbDoNotTrim = 1;
    }else
    if( z[0]=='/' && z[1]=='*' ){
      z += 2;
      while( z[0]!='*' || z[1]!='/' ){
        if( z[1]=='\0' ) return CIDX_PARSE_EOF;
        z++;
      }
      z += 2;
    }else{
      *pzOut = z;
      if( pbDoNotTrim==0 ) return CIDX_PARSE_EOF;
      switch( *z ){
        case '\0':
          return CIDX_PARSE_EOF;
        case '(':
          return CIDX_PARSE_OPEN;
        case ')':
          return CIDX_PARSE_CLOSE;
        case ',':
          return CIDX_PARSE_COMMA;
  
        case '"': 
        case '\'': 
        case '`': {
          char q = *z;
          z++;
          while( *z ){
            if( *z==q ){
              z++;
              if( *z!=q ) break;
            }
            z++;
          }
          break;
        }
  
        case '[':
          while( *z++!=']' );
          break;
  
        default:
          z++;
          break;
      }
      *pbDoNotTrim = 0;
    }
  }

  assert( 0 );
  return -1;
}

static int cidxParseSQL(CidxCursor *pCsr, CidxIndex *pIdx, const char *zSql){
  const char *z = zSql;
  const char *z1;
  int e;
  int rc = SQLITE_OK;
  int nParen = 1;
  int bDoNotTrim = 0;
  CidxColumn *pCol = pIdx->aCol;

  e = cidxFindNext(z, &z, &bDoNotTrim);
  if( e!=CIDX_PARSE_OPEN ) goto parse_error;
  z1 = z+1;
  z++;
  while( nParen>0 ){
    e = cidxFindNext(z, &z, &bDoNotTrim);
    if( e==CIDX_PARSE_EOF ) goto parse_error;
    if( (e==CIDX_PARSE_COMMA || e==CIDX_PARSE_CLOSE) && nParen==1 ){
      const char *z2 = z;
      if( pCol->zExpr ) goto parse_error;

      if( bDoNotTrim==0 ){
        while( cidx_isspace(z[-1]) ) z--;
        if( !sqlite3_strnicmp(&z[-3], "asc", 3) && 0==cidx_isident(z[-4]) ){
          z -= 3;
          while( cidx_isspace(z[-1]) ) z--;
        }else
          if( !sqlite3_strnicmp(&z[-4], "desc", 4) && 0==cidx_isident(z[-5]) ){
            z -= 4;
            while( cidx_isspace(z[-1]) ) z--;
          }
        while( cidx_isspace(z1[0]) ) z1++;
      }

      pCol->zExpr = cidxMprintf(&rc, "%.*s", z-z1, z1);
      pCol++;
      z = z1 = z2+1;
    }
    if( e==CIDX_PARSE_OPEN ) nParen++;
    if( e==CIDX_PARSE_CLOSE ) nParen--;
    z++;
  }

  /* Search for a WHERE clause */
  cidxFindNext(z, &z, 0);
  if( 0==sqlite3_strnicmp(z, "where", 5) ){
    pIdx->zWhere = cidxMprintf(&rc, "%s\n", &z[5]);
  }else if( z[0]!='\0' ){
    goto parse_error;
  }

  return rc;

 parse_error:
  cidxCursorError(pCsr, "Parse error in: %s", zSql);
  return SQLITE_ERROR;
}

static int cidxLookupIndex(
  CidxCursor *pCsr,               /* Cursor object */
  const char *zIdx,               /* Name of index to look up */
  CidxIndex **ppIdx,              /* OUT: Description of columns */
  char **pzTab                    /* OUT: Table name */
){
  int rc = SQLITE_OK;
  char *zTab = 0;
  CidxIndex *pIdx = 0;

  sqlite3_stmt *pFindTab = 0;
  sqlite3_stmt *pInfo = 0;
    
  /* Find the table for this index. */
  pFindTab = cidxPrepare(&rc, pCsr, 
      "SELECT tbl_name, sql FROM sqlite_master WHERE name=%Q AND type='index'",
      zIdx
  );
  if( rc==SQLITE_OK && sqlite3_step(pFindTab)==SQLITE_ROW ){
    const char *zSql = (const char*)sqlite3_column_text(pFindTab, 1);
    zTab = cidxStrdup(&rc, (const char*)sqlite3_column_text(pFindTab, 0));

    pInfo = cidxPrepare(&rc, pCsr, "PRAGMA index_xinfo(%Q)", zIdx);
    if( rc==SQLITE_OK ){
      int nAlloc = 0;
      int iCol = 0;

      while( sqlite3_step(pInfo)==SQLITE_ROW ){
        const char *zName = (const char*)sqlite3_column_text(pInfo, 2);
        const char *zColl = (const char*)sqlite3_column_text(pInfo, 4);
        CidxColumn *p;
        if( zName==0 ) zName = "rowid";
        if( iCol==nAlloc ){
          int nByte = sizeof(CidxIndex) + sizeof(CidxColumn)*(nAlloc+8);
          pIdx = (CidxIndex*)sqlite3_realloc(pIdx, nByte);
          nAlloc += 8;
        }
        p = &pIdx->aCol[iCol++];
        p->bDesc = sqlite3_column_int(pInfo, 3);
        p->bKey = sqlite3_column_int(pInfo, 5);
        if( zSql==0 || p->bKey==0 ){
          p->zExpr = cidxMprintf(&rc, "\"%w\" COLLATE %s",zName,zColl);
        }else{
          p->zExpr = 0;
        }
        pIdx->nCol = iCol;
        pIdx->zWhere = 0;
      }
      cidxFinalize(&rc, pInfo);
    }

    if( rc==SQLITE_OK && zSql ){
      rc = cidxParseSQL(pCsr, pIdx, zSql);
    }
  }

  cidxFinalize(&rc, pFindTab);
  if( rc==SQLITE_OK && zTab==0 ){
    rc = SQLITE_ERROR;
  }
  
  if( rc!=SQLITE_OK ){
    sqlite3_free(zTab);
    cidxFreeIndex(pIdx);
  }else{
    *pzTab = zTab;
    *ppIdx = pIdx;
  }

  return rc;
}

static int cidxDecodeAfter(
  CidxCursor *pCsr, 
  int nCol, 
  const char *zAfterKey, 
  char ***pazAfter
){
  char **azAfter;
  int rc = SQLITE_OK;
  int nAfterKey = (int)strlen(zAfterKey);

  azAfter = cidxMalloc(&rc, sizeof(char*)*nCol + nAfterKey+1);
  if( rc==SQLITE_OK ){
    int i;
    char *zCopy = (char*)&azAfter[nCol];
    char *p = zCopy;
    memcpy(zCopy, zAfterKey, nAfterKey+1);
    for(i=0; i<nCol; i++){
      while( *p==' ' ) p++;

      /* Check NULL values */
      if( *p=='N' ){
        if( memcmp(p, "NULL", 4) ) goto parse_error;
        p += 4;
      }

      /* Check strings and blob literals */
      else if( *p=='X' || *p=='\'' ){
        azAfter[i] = p;
        if( *p=='X' ) p++;
        if( *p!='\'' ) goto parse_error;
        p++;
        while( 1 ){
          if( *p=='\0' ) goto parse_error;
          if( *p=='\'' ){
            p++;
            if( *p!='\'' ) break;
          }
          p++;
        }
      }

      /* Check numbers */
      else{
        azAfter[i] = p;
        while( (*p>='0' && *p<='9') 
            || *p=='.' || *p=='+' || *p=='-' || *p=='e' || *p=='E'
        ){
          p++;
        }
      }

      while( *p==' ' ) p++;
      if( *p!=(i==(nCol-1) ? '\0' : ',') ){
        goto parse_error;
      }
      *p++ = '\0';
    }
  }

  *pazAfter = azAfter;
  return rc;

 parse_error:
  sqlite3_free(azAfter);
  *pazAfter = 0;
  cidxCursorError(pCsr, "%s", "error parsing after value");
  return SQLITE_ERROR;
}

static char *cidxWhere(
  int *pRc, CidxColumn *aCol, char **azAfter, int iGt, int bLastIsNull
){
  char *zRet = 0;
  const char *zSep = "";
  int i;

  for(i=0; i<iGt; i++){
    zRet = cidxMprintf(pRc, "%z%s(%s) IS %s", zRet, 
        zSep, aCol[i].zExpr, (azAfter[i] ? azAfter[i] : "NULL")
    );
    zSep = " AND ";
  }

  if( bLastIsNull ){
    zRet = cidxMprintf(pRc, "%z%s(%s) IS NULL", zRet, zSep, aCol[iGt].zExpr);
  }
  else if( azAfter[iGt] ){
    zRet = cidxMprintf(pRc, "%z%s(%s) %s %s", zRet, 
        zSep, aCol[iGt].zExpr, (aCol[iGt].bDesc ? "<" : ">"), 
        azAfter[iGt]
    );
  }else{
    zRet = cidxMprintf(pRc, "%z%s(%s) IS NOT NULL", zRet, zSep,aCol[iGt].zExpr);
  }

  return zRet;
}

#define CIDX_CLIST_ALL         0
#define CIDX_CLIST_ORDERBY     1
#define CIDX_CLIST_CURRENT_KEY 2
#define CIDX_CLIST_SUBWHERE    3
#define CIDX_CLIST_SUBEXPR     4

/*
** This function returns various strings based on the contents of the
** CidxIndex structure and the eType parameter.
*/
static char *cidxColumnList(
  int *pRc,                       /* IN/OUT: Error code */
  const char *zIdx,
  CidxIndex *pIdx,                /* Indexed columns */
  int eType                       /* True to include ASC/DESC */
){
  char *zRet = 0;
  if( *pRc==SQLITE_OK ){
    const char *aDir[2] = {"", " DESC"};
    int i;
    const char *zSep = "";

    for(i=0; i<pIdx->nCol; i++){
      CidxColumn *p = &pIdx->aCol[i];
      assert( pIdx->aCol[i].bDesc==0 || pIdx->aCol[i].bDesc==1 );
      switch( eType ){

        case CIDX_CLIST_ORDERBY:
          zRet = cidxMprintf(pRc, "%z%s%d%s", zRet, zSep, i+1, aDir[p->bDesc]);
          zSep = ",";
          break;

        case CIDX_CLIST_CURRENT_KEY:
          zRet = cidxMprintf(pRc, "%z%squote(i%d)", zRet, zSep, i);
          zSep = "||','||";
          break;

        case CIDX_CLIST_SUBWHERE:
          if( p->bKey==0 ){
            zRet = cidxMprintf(pRc, "%z%s%s IS i.i%d", zRet, 
                zSep, p->zExpr, i
            );
            zSep = " AND ";
          }
          break;

        case CIDX_CLIST_SUBEXPR:
          if( p->bKey==1 ){
            zRet = cidxMprintf(pRc, "%z%s%s IS i.i%d", zRet, 
                zSep, p->zExpr, i
            );
            zSep = " AND ";
          }
          break;

        default:
          assert( eType==CIDX_CLIST_ALL );
          zRet = cidxMprintf(pRc, "%z%s(%s) AS i%d", zRet, zSep, p->zExpr, i);
          zSep = ", ";
          break;
      }
    }
  }

  return zRet;
}

/*
** Generate SQL (in memory obtained from sqlite3_malloc()) that will
** continue the index scan for zIdxName starting after zAfterKey.
*/
int cidxGenerateScanSql(
  CidxCursor *pCsr,           /* The cursor which needs the new statement */
  const char *zIdxName,       /* index to be scanned */
  const char *zAfterKey,      /* start after this key, if not NULL */
  char **pzSqlOut             /* OUT: Write the generated SQL here */
){
  int rc;
  char *zTab = 0;
  char *zCurrentKey = 0;
  char *zOrderBy = 0;
  char *zSubWhere = 0;
  char *zSubExpr = 0;
  char *zSrcList = 0;
  char **azAfter = 0;
  CidxIndex *pIdx = 0;

  *pzSqlOut = 0;
  rc = cidxLookupIndex(pCsr, zIdxName, &pIdx, &zTab);

  zOrderBy = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_ORDERBY);
  zCurrentKey = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_CURRENT_KEY);
  zSubWhere = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_SUBWHERE);
  zSubExpr = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_SUBEXPR);
  zSrcList = cidxColumnList(&rc, zIdxName, pIdx, CIDX_CLIST_ALL);

  if( rc==SQLITE_OK && zAfterKey ){
    rc = cidxDecodeAfter(pCsr, pIdx->nCol, zAfterKey, &azAfter);
  }

  if( rc==SQLITE_OK ){
    if( zAfterKey==0 ){
      *pzSqlOut = cidxMprintf(&rc,
          "SELECT (SELECT %s FROM %Q AS t WHERE %s), %s "
          "FROM (SELECT %s FROM %Q INDEXED BY %Q %s%sORDER BY %s) AS i",
          zSubExpr, zTab, zSubWhere, zCurrentKey, 
          zSrcList, zTab, zIdxName, 
          (pIdx->zWhere ? "WHERE " : ""), (pIdx->zWhere ? pIdx->zWhere : ""),
          zOrderBy
      );
    }else{
      const char *zSep = "";
      char *zSql;
      int i;
  
      zSql = cidxMprintf(&rc, 
          "SELECT (SELECT %s FROM %Q WHERE %s), %s FROM (",
          zSubExpr, zTab, zSubWhere, zCurrentKey
      );
      for(i=pIdx->nCol-1; i>=0; i--){
        int j;
        if( pIdx->aCol[i].bDesc && azAfter[i]==0 ) continue;
        for(j=0; j<2; j++){
          char *zWhere = cidxWhere(&rc, pIdx->aCol, azAfter, i, j);
          zSql = cidxMprintf(&rc, "%z"
              "%sSELECT * FROM ("
                "SELECT %s FROM %Q INDEXED BY %Q WHERE %s%s%z ORDER BY %s"
              ")",
              zSql, zSep, zSrcList, zTab, zIdxName, 
              pIdx->zWhere ? pIdx->zWhere : "",
              pIdx->zWhere ? " AND " : "",
              zWhere, zOrderBy
          );
          zSep = " UNION ALL ";
          if( pIdx->aCol[i].bDesc==0 ) break;
        }
      }
      *pzSqlOut = cidxMprintf(&rc, "%z) AS i", zSql);
    }
  }

  sqlite3_free(zTab);
  sqlite3_free(zCurrentKey);
  sqlite3_free(zOrderBy);
  sqlite3_free(zSubWhere);
  sqlite3_free(zSubExpr);
  sqlite3_free(zSrcList);
  cidxFreeIndex(pIdx);
  sqlite3_free(azAfter);
  return rc;
}


/* 
** Position a cursor back to the beginning.
*/
static int cidxFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  int rc = SQLITE_OK;
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  const char *zIdxName = 0;
  const char *zAfterKey = 0;

  sqlite3_free(pCsr->zIdxName);
  pCsr->zIdxName = 0;
  sqlite3_free(pCsr->zAfterKey);
  pCsr->zAfterKey = 0;
  sqlite3_finalize(pCsr->pStmt);
  pCsr->pStmt = 0;

  if( argc>0 ){
    zIdxName = (const char*)sqlite3_value_text(argv[0]);
    if( argc>1 ){
      zAfterKey = (const char*)sqlite3_value_text(argv[1]);
    }
  }

  if( zIdxName ){
    char *zSql = 0;
    pCsr->zIdxName = sqlite3_mprintf("%s", zIdxName);
    pCsr->zAfterKey = zAfterKey ? sqlite3_mprintf("%s", zAfterKey) : 0;
    rc = cidxGenerateScanSql(pCsr, zIdxName, zAfterKey, &zSql);
    if( zSql ){
      pCsr->pStmt = cidxPrepare(&rc, pCsr, "%z", zSql);
    }
  }

  if( pCsr->pStmt ){
    assert( rc==SQLITE_OK );
    rc = cidxNext(pCursor);
  }
  pCsr->iRowid = 1;
  return rc;
}

/* 
** Return a column value.
*/
static int cidxColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int iCol
){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  assert( iCol>=IIC_ERRMSG && iCol<=IIC_SCANNER_SQL );
  switch( iCol ){
    case IIC_ERRMSG: {
      const char *zVal = 0;
      if( sqlite3_column_type(pCsr->pStmt, 0)==SQLITE_INTEGER ){
        if( sqlite3_column_int(pCsr->pStmt, 0)==0 ){
          zVal = "row data mismatch";
        }
      }else{
        zVal = "row missing";
      }
      sqlite3_result_text(ctx, zVal, -1, SQLITE_STATIC);
      break;
    }
    case IIC_CURRENT_KEY: {
      sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pStmt, 1));
      break;
    }
    case IIC_INDEX_NAME: {
      sqlite3_result_text(ctx, pCsr->zIdxName, -1, SQLITE_TRANSIENT);
      break;
    }
    case IIC_AFTER_KEY: {
      sqlite3_result_text(ctx, pCsr->zAfterKey, -1, SQLITE_TRANSIENT);
      break;
    }
    case IIC_SCANNER_SQL: {
      char *zSql = 0;
      cidxGenerateScanSql(pCsr, pCsr->zIdxName, pCsr->zAfterKey, &zSql);
      sqlite3_result_text(ctx, zSql, -1, sqlite3_free);
      break;
    }
  }
  return SQLITE_OK;
}

/* Return the ROWID for the sqlite_btreeinfo table */
static int cidxRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  CidxCursor *pCsr = (CidxCursor*)pCursor;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}

/*
** Register the virtual table modules with the database handle passed
** as the only argument.
*/
static int ciInit(sqlite3 *db){
  static sqlite3_module cidx_module = {
    0,                            /* iVersion */
    0,                            /* xCreate */
    cidxConnect,                  /* xConnect */
    cidxBestIndex,                /* xBestIndex */
    cidxDisconnect,               /* xDisconnect */
    0,                            /* xDestroy */
    cidxOpen,                     /* xOpen - open a cursor */
    cidxClose,                    /* xClose - close a cursor */
    cidxFilter,                   /* xFilter - configure scan constraints */
    cidxNext,                     /* xNext - advance a cursor */
    cidxEof,                      /* xEof - check for end of scan */
    cidxColumn,                   /* xColumn - read data */
    cidxRowid,                    /* xRowid - read data */
    0,                            /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
  };
  return sqlite3_create_module(db, "incremental_index_check", &cidx_module, 0);
}

/*
** Extension load function.
*/
#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_checkindex_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return ciInit(db);
}

/*
** Read an SQLite database file and analyze its space utilization.  Generate
** text on standard output.
*/
#define TCLSH_INIT_PROC sqlite3_checker_init_proc
#define SQLITE_ENABLE_DBPAGE_VTAB 1
#define SQLITE_ENABLE_JSON1 1
#undef SQLITE_THREADSAFE
#define SQLITE_THREADSAFE 0
#undef SQLITE_ENABLE_COLUMN_METADATA
#define SQLITE_OMIT_DECLTYPE 1
#define SQLITE_OMIT_DEPRECATED 1
#define SQLITE_OMIT_PROGRESS_CALLBACK 1
#define SQLITE_OMIT_SHARED_CACHE 1
#define SQLITE_DEFAULT_MEMSTATUS 0
#define SQLITE_MAX_EXPR_DEPTH 0
INCLUDE sqlite3.c
INCLUDE $ROOT/src/tclsqlite.c
INCLUDE $ROOT/ext/misc/btreeinfo.c
INCLUDE $ROOT/ext/repair/checkindex.c
INCLUDE $ROOT/ext/repair/checkfreelist.c

/*
** Decode a pointer to an sqlite3 object.
*/
int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){
  struct SqliteDb *p;
  Tcl_CmdInfo cmdInfo;
  if( Tcl_GetCommandInfo(interp, zA, &cmdInfo) ){
    p = (struct SqliteDb*)cmdInfo.objClientData;
    *ppDb = p->db;
    return TCL_OK;
  }else{
    *ppDb = 0;
    return TCL_ERROR;
  }
  return TCL_OK;
}

/*
**   sqlite3_imposter db main rootpage {CREATE TABLE...}  ;# setup an imposter
**   sqlite3_imposter db main                             ;# rm all imposters
*/
static int sqlite3_imposter(
  void *clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  const char *zSchema;
  int iRoot;
  const char *zSql;

  if( objc!=3 && objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB SCHEMA [ROOTPAGE SQL]");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  zSchema = Tcl_GetString(objv[2]);
  if( objc==3 ){
    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, zSchema, 0, 1);
  }else{
    if( Tcl_GetIntFromObj(interp, objv[3], &iRoot) ) return TCL_ERROR;
    zSql = Tcl_GetString(objv[4]);
    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, zSchema, 1, iRoot);
    sqlite3_exec(db, zSql, 0, 0, 0);
    sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, zSchema, 0, 0);
  }
  return TCL_OK;
}

#include <stdio.h>

const char *sqlite3_checker_init_proc(Tcl_Interp *interp){
  Tcl_CreateObjCommand(interp, "sqlite3_imposter", 
                       (Tcl_ObjCmdProc*)sqlite3_imposter, 0, 0);
  sqlite3_auto_extension((void(*)(void))sqlite3_btreeinfo_init);
  sqlite3_auto_extension((void(*)(void))sqlite3_checkindex_init);
  sqlite3_auto_extension((void(*)(void))sqlite3_checkfreelist_init);
  return
BEGIN_STRING
INCLUDE $ROOT/ext/repair/sqlite3_checker.tcl
END_STRING
;
}

# This TCL script is the main driver script for the sqlite3_checker utility
# program.
#

# Special case:
#
#      sqlite3_checker --test FILENAME ARGS
#
# uses FILENAME in place of this script.
#
if {[lindex $argv 0]=="--test" && [llength $argv]>1} {
  set ::argv0 [lindex $argv 1]
  set argv [lrange $argv 2 end]
  source $argv0
  exit 0
}

# Emulate a TCL shell
#
proc tclsh {} {
  set line {}
  while {![eof stdin]} {
    if {$line!=""} {
      puts -nonewline "> "
    } else {
      puts -nonewline "% "
    }
    flush stdout
    append line [gets stdin]
    if {[info complete $line]} {
      if {[catch {uplevel #0 $line} result]} {
        puts stderr "Error: $result"
      } elseif {$result!=""} {
        puts $result
      }
      set line {}
    } else {
      append line \n
    }
  }
}

# Do an incremental integrity check of a single index
#
proc check_index {idxname batchsize bTrace} {
  set i 0
  set more 1
  set nerr 0
  set pct 00.0
  set max [db one {SELECT nEntry FROM sqlite_btreeinfo('main')
                    WHERE name=$idxname}]
  puts -nonewline "$idxname: $i of $max rows ($pct%)\r"
  flush stdout
  if {$bTrace} {
    set sql {SELECT errmsg, current_key AS key,
                    CASE WHEN rowid=1 THEN scanner_sql END AS traceOut
               FROM incremental_index_check($idxname)
              WHERE after_key=$key
              LIMIT $batchsize}
  } else {
    set sql {SELECT errmsg, current_key AS key, NULL AS traceOut
               FROM incremental_index_check($idxname)
              WHERE after_key=$key
              LIMIT $batchsize}
  }
  while {$more} {
    set more 0
    db eval $sql {
      set more 1
      if {$errmsg!=""} {
        incr nerr
        puts "$idxname: key($key): $errmsg"
      } elseif {$traceOut!=""} {
        puts "$idxname: $traceOut"
      }
      incr i
      
    }
    set x [format {%.1f} [expr {($i*100.0)/$max}]]
    if {$x!=$pct} {
      puts -nonewline "$idxname: $i of $max rows ($pct%)\r"
      flush stdout
      set pct $x
    }
  }
  puts "$idxname: $nerr errors out of $i entries"
}

# Print a usage message on standard error, then quit.
#
proc usage {} {
  set argv0 [file rootname [file tail [info nameofexecutable]]]
  puts stderr "Usage: $argv0 OPTIONS database-filename"
  puts stderr {
Do sanity checking on a live SQLite3 database file specified by the
"database-filename" argument.

Options:

   --batchsize N     Number of rows to check per transaction

   --freelist        Perform a freelist check

   --index NAME      Run a check of the index NAME

   --summary         Print summary information about the database

   --table NAME      Run a check of all indexes for table NAME

   --tclsh           Run the built-in TCL interpreter (for debugging)

   --trace           (Debugging only:) Output trace information on the scan

   --version         Show the version number of SQLite
}
  exit 1
}

set file_to_analyze {}
append argv {}
set bFreelistCheck 0
set bSummary 0
set zIndex {}
set zTable {}
set batchsize 1000
set bAll 1
set bTrace 0
set argc [llength $argv]
for {set i 0} {$i<$argc} {incr i} {
  set arg [lindex $argv $i]
  if {[regexp {^-+tclsh$} $arg]} {
    tclsh
    exit 0
  }
  if {[regexp {^-+version$} $arg]} {
    sqlite3 mem :memory:
    puts [mem one {SELECT sqlite_version()||' '||sqlite_source_id()}]
    mem close
    exit 0
  }
  if {[regexp {^-+freelist$} $arg]} {
    set bFreelistCheck 1
    set bAll 0
    continue
  }
  if {[regexp {^-+summary$} $arg]} {
    set bSummary 1
    set bAll 0
    continue
  }
  if {[regexp {^-+trace$} $arg]} {
    set bTrace 1
    continue
  }
  if {[regexp {^-+batchsize$} $arg]} {
    incr i
    if {$i>=$argc} {
      puts stderr "missing argument on $arg"
      exit 1
    }
    set batchsize [lindex $argv $i]
    continue
  }
  if {[regexp {^-+index$} $arg]} {
    incr i
    if {$i>=$argc} {
      puts stderr "missing argument on $arg"
      exit 1
    }
    set zIndex [lindex $argv $i]
    set bAll 0
    continue
  }
  if {[regexp {^-+table$} $arg]} {
    incr i
    if {$i>=$argc} {
      puts stderr "missing argument on $arg"
      exit 1
    }
    set zTable [lindex $argv $i]
    set bAll 0
    continue
  }
  if {[regexp {^-} $arg]} {
    puts stderr "Unknown option: $arg"
    usage
  }
  if {$file_to_analyze!=""} {
    usage
  } else {
    set file_to_analyze $arg
  }
}
if {$file_to_analyze==""} usage

# If a TCL script is specified on the command-line, then run that
# script.
#
if {[file extension $file_to_analyze]==".tcl"} {
  source $file_to_analyze
  exit 0
}

set root_filename $file_to_analyze
regexp {^file:(//)?([^?]*)} $file_to_analyze all x1 root_filename
if {![file exists $root_filename]} {
  puts stderr "No such file: $root_filename"
  exit 1
}
if {![file readable $root_filename]} {
  puts stderr "File is not readable: $root_filename"
  exit 1
}

if {[catch {sqlite3 db $file_to_analyze} res]} {
  puts stderr "Cannot open datababase $root_filename: $res"
  exit 1
}

if {$bFreelistCheck || $bAll} {
  puts -nonewline "freelist-check: "
  flush stdout
  puts [db one {SELECT checkfreelist('main')}]
}
if {$bSummary} {
  set scale 0
  set pgsz [db one {PRAGMA page_size}]
  db eval {SELECT nPage*$pgsz AS sz, name, tbl_name
             FROM sqlite_btreeinfo
            WHERE type='index'
            ORDER BY 1 DESC, name} {
    if {$scale==0} {
      if {$sz>10000000} {
        set scale 1000000.0
        set unit MB
      } else {
        set scale 1000.0
        set unit KB
      }
    }
    puts [format {%7.1f %s index %s of table %s} \
            [expr {$sz/$scale}] $unit $name $tbl_name]
  }
}
if {$zIndex!=""} {
  check_index $zIndex $batchsize $bTrace
}
if {$zTable!=""} {
  foreach idx [db eval {SELECT name FROM sqlite_master
                         WHERE type='index' AND rootpage>0
                           AND tbl_name=$zTable}] {
    check_index $idx $batchsize $bTrace
  }
}
if {$bAll} {
  set allidx [db eval {SELECT name FROM sqlite_btreeinfo('main')
                        WHERE type='index' AND rootpage>0
                        ORDER BY nEntry}]
  foreach idx $allidx {
    check_index $idx $batchsize $bTrace
  }
}

To run these tests, first build sqlite3_checker:


>     make sqlite3_checker


Then run the "test.tcl" script using:


>     ./sqlite3_checker --test $path/test.tcl


Optionally add the full pathnames of individual *.test modules

# 2017-10-11

set testprefix checkfreelist

do_execsql_test 1.0 {
  PRAGMA page_size=1024;
  CREATE TABLE t1(a, b);
}

do_execsql_test 1.2 { SELECT checkfreelist('main') } {ok}
do_execsql_test 1.3 {
  WITH s(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10000
  )
  INSERT INTO t1 SELECT randomblob(400), randomblob(400) FROM s;
  DELETE FROM t1 WHERE rowid%3;
  PRAGMA freelist_count;
} {6726}

do_execsql_test 1.4 { SELECT checkfreelist('main') } {ok}
do_execsql_test 1.5 {
  WITH freelist_trunk(i, d, n) AS (
    SELECT 1, NULL, sqlite_readint32(data, 32) FROM sqlite_dbpage WHERE pgno=1
      UNION ALL
    SELECT n, data, sqlite_readint32(data) 
    FROM freelist_trunk, sqlite_dbpage WHERE pgno=n
  )
  SELECT i FROM freelist_trunk WHERE i!=1;
} {
  10009 9715 9343 8969 8595 8222 7847 7474 7102 6727 6354 5982 5608 5234
  4860 4487 4112 3740 3367 2992 2619 2247 1872 1499 1125 752 377 5
}

do_execsql_test 1.6 { SELECT checkfreelist('main') } {ok}

proc set_int {blob idx newval} {
  binary scan $blob I* ints
  lset ints $idx $newval
  binary format I* $ints
}
db func set_int set_int

proc get_int {blob idx} {
  binary scan $blob I* ints
  lindex $ints $idx
}
db func get_int get_int

do_execsql_test 1.7 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 1, get_int(data, 1)-1) 
      WHERE pgno=4860;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{free-list count mismatch: actual=6725 header=6726}}

do_execsql_test 1.8 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 5, (SELECT * FROM pragma_page_count)+1)
      WHERE pgno=4860;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 10092 is out of range (child 3 of trunk page 4860)}}

do_execsql_test 1.9 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 5, 0)
      WHERE pgno=4860;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 0 is out of range (child 3 of trunk page 4860)}}

do_execsql_test 1.10 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, get_int(data, 1)+1, 0)
      WHERE pgno=5;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 0 is out of range (child 247 of trunk page 5)}}

do_execsql_test 1.11 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 1, 249)
      WHERE pgno=5;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf count out of range (249) on trunk page 5}}

# 2017-10-11
#
set testprefix checkindex

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  CREATE INDEX i1 ON t1(a);
  INSERT INTO t1 VALUES('one', 2);
  INSERT INTO t1 VALUES('two', 4);
  INSERT INTO t1 VALUES('three', 6);
  INSERT INTO t1 VALUES('four', 8);
  INSERT INTO t1 VALUES('five', 10);

  CREATE INDEX i2 ON t1(a DESC);
} {}

proc incr_index_check {idx nStep} {
  set Q {
    SELECT errmsg, current_key FROM incremental_index_check($idx, $after)
    LIMIT $nStep
  }

  set res [list]
  while {1} {
    unset -nocomplain current_key
    set res1 [db eval $Q]
    if {[llength $res1]==0} break
    set res [concat $res $res1]
    set after [lindex $res end]
  }

  return $res
}

proc do_index_check_test {tn idx res} {
  uplevel [list do_execsql_test $tn.1 "
    SELECT errmsg, current_key FROM incremental_index_check('$idx');
  " $res]

  uplevel [list do_test $tn.2 "incr_index_check $idx 1" [list {*}$res]]
  uplevel [list do_test $tn.3 "incr_index_check $idx 2" [list {*}$res]]
  uplevel [list do_test $tn.4 "incr_index_check $idx 5" [list {*}$res]]
}


do_execsql_test 1.2.1 {
  SELECT rowid, errmsg IS NULL, current_key FROM incremental_index_check('i1');
} {
  1 1 'five',5
  2 1 'four',4
  3 1 'one',1
  4 1 'three',3
  5 1 'two',2
}
do_execsql_test 1.2.2 {
  SELECT errmsg IS NULL, current_key, index_name, after_key, scanner_sql
    FROM incremental_index_check('i1') LIMIT 1;
} {
  1
  'five',5
  i1
  {}
  {SELECT (SELECT a IS i.i0 FROM 't1' AS t WHERE "rowid" COLLATE BINARY IS i.i1), quote(i0)||','||quote(i1) FROM (SELECT (a) AS i0, ("rowid" COLLATE BINARY) AS i1 FROM 't1' INDEXED BY 'i1' ORDER BY 1,2) AS i}
}

do_index_check_test 1.3 i1 {
  {} 'five',5
  {} 'four',4
  {} 'one',1
  {} 'three',3
  {} 'two',2
}

do_index_check_test 1.4 i2 {
  {} 'two',2
  {} 'three',3
  {} 'one',1
  {} 'four',4
  {} 'five',5
}

do_test 1.5 {
  set tblroot [db one { SELECT rootpage FROM sqlite_master WHERE name='t1' }]
  sqlite3_imposter db main $tblroot {CREATE TABLE xt1(a,b)}
  db eval {
    UPDATE xt1 SET a='six' WHERE rowid=3;
    DELETE FROM xt1 WHERE rowid = 5;
  }
  sqlite3_imposter db main
} {}

do_index_check_test 1.6 i1 {
  {row missing} 'five',5
  {} 'four',4
  {} 'one',1
  {row data mismatch} 'three',3
  {} 'two',2
}

do_index_check_test 1.7 i2 {
  {} 'two',2
  {row data mismatch} 'three',3
  {} 'one',1
  {} 'four',4
  {row missing} 'five',5
}

#--------------------------------------------------------------------------
do_execsql_test 2.0 {

  CREATE TABLE t2(a INTEGER PRIMARY KEY, b, c, d);

  INSERT INTO t2 VALUES(1, NULL, 1, 1);
  INSERT INTO t2 VALUES(2, 1, NULL, 1);
  INSERT INTO t2 VALUES(3, 1, 1, NULL);

  INSERT INTO t2 VALUES(4, 2, 2, 1);
  INSERT INTO t2 VALUES(5, 2, 2, 2);
  INSERT INTO t2 VALUES(6, 2, 2, 3);

  INSERT INTO t2 VALUES(7, 2, 2, 1);
  INSERT INTO t2 VALUES(8, 2, 2, 2);
  INSERT INTO t2 VALUES(9, 2, 2, 3);

  CREATE INDEX i3 ON t2(b, c, d);
  CREATE INDEX i4 ON t2(b DESC, c DESC, d DESC);
  CREATE INDEX i5 ON t2(d, c DESC, b);
} {}

do_index_check_test 2.1 i3 {
  {} NULL,1,1,1 
  {} 1,NULL,1,2 
  {} 1,1,NULL,3 
  {} 2,2,1,4 
  {} 2,2,1,7 
  {} 2,2,2,5
  {} 2,2,2,8 
  {} 2,2,3,6 
  {} 2,2,3,9
}

do_index_check_test 2.2 i4 {
  {} 2,2,3,6 
  {} 2,2,3,9
  {} 2,2,2,5
  {} 2,2,2,8 
  {} 2,2,1,4 
  {} 2,2,1,7 
  {} 1,1,NULL,3 
  {} 1,NULL,1,2 
  {} NULL,1,1,1 
}

do_index_check_test 2.3 i5 {
  {} NULL,1,1,3 
  {} 1,2,2,4 
  {} 1,2,2,7 
  {} 1,1,NULL,1 
  {} 1,NULL,1,2 
  {} 2,2,2,5 
  {} 2,2,2,8 
  {} 3,2,2,6 
  {} 3,2,2,9
}

#--------------------------------------------------------------------------
do_execsql_test 3.0 {

  CREATE TABLE t3(w, x, y, z PRIMARY KEY) WITHOUT ROWID;
  CREATE INDEX t3wxy ON t3(w, x, y);
  CREATE INDEX t3wxy2 ON t3(w DESC, x DESC, y DESC);

  INSERT INTO t3 VALUES(NULL, NULL, NULL, 1);
  INSERT INTO t3 VALUES(NULL, NULL, NULL, 2);
  INSERT INTO t3 VALUES(NULL, NULL, NULL, 3);

  INSERT INTO t3 VALUES('a', NULL, NULL, 4);
  INSERT INTO t3 VALUES('a', NULL, NULL, 5);
  INSERT INTO t3 VALUES('a', NULL, NULL, 6);

  INSERT INTO t3 VALUES('a', 'b', NULL, 7);
  INSERT INTO t3 VALUES('a', 'b', NULL, 8);
  INSERT INTO t3 VALUES('a', 'b', NULL, 9);

} {}

do_index_check_test 3.1 t3wxy {
  {} NULL,NULL,NULL,1 {} NULL,NULL,NULL,2 {} NULL,NULL,NULL,3 
  {} 'a',NULL,NULL,4  {} 'a',NULL,NULL,5  {} 'a',NULL,NULL,6 
  {} 'a','b',NULL,7   {} 'a','b',NULL,8   {} 'a','b',NULL,9 
}
do_index_check_test 3.2 t3wxy2 {
  {} 'a','b',NULL,7   {} 'a','b',NULL,8   {} 'a','b',NULL,9 
  {} 'a',NULL,NULL,4  {} 'a',NULL,NULL,5  {} 'a',NULL,NULL,6 
  {} NULL,NULL,NULL,1 {} NULL,NULL,NULL,2 {} NULL,NULL,NULL,3 
}

#--------------------------------------------------------------------------
# Test with an index that uses non-default collation sequences.
#
do_execsql_test 4.0 {
  CREATE TABLE t4(a INTEGER PRIMARY KEY, c1 TEXT, c2 TEXT);
  INSERT INTO t4 VALUES(1, 'aaa', 'bbb');
  INSERT INTO t4 VALUES(2, 'AAA', 'CCC');
  INSERT INTO t4 VALUES(3, 'aab', 'ddd');
  INSERT INTO t4 VALUES(4, 'AAB', 'EEE');

  CREATE INDEX t4cc ON t4(c1 COLLATE nocase, c2 COLLATE nocase);
}

do_index_check_test 4.1 t4cc {
  {} 'aaa','bbb',1 
  {} 'AAA','CCC',2 
  {} 'aab','ddd',3 
  {} 'AAB','EEE',4
}

do_test 4.2 {
  set tblroot [db one { SELECT rootpage FROM sqlite_master WHERE name='t4' }]
  sqlite3_imposter db main $tblroot \
     {CREATE TABLE xt4(a INTEGER PRIMARY KEY, c1 TEXT, c2 TEXT)}

  db eval {
    UPDATE xt4 SET c1='hello' WHERE rowid=2;
    DELETE FROM xt4 WHERE rowid = 3;
  }
  sqlite3_imposter db main
} {}

do_index_check_test 4.3 t4cc {
  {} 'aaa','bbb',1 
  {row data mismatch} 'AAA','CCC',2 
  {row missing} 'aab','ddd',3 
  {} 'AAB','EEE',4
}

#--------------------------------------------------------------------------
# Test an index on an expression.
#
do_execsql_test 5.0 {
  CREATE TABLE t5(x INTEGER PRIMARY KEY, y TEXT, UNIQUE(y));
  INSERT INTO t5 VALUES(1, '{"x":1, "y":1}');
  INSERT INTO t5 VALUES(2, '{"x":2, "y":2}');
  INSERT INTO t5 VALUES(3, '{"x":3, "y":3}');
  INSERT INTO t5 VALUES(4, '{"w":4, "z":4}');
  INSERT INTO t5 VALUES(5, '{"x":5, "y":5}');

  CREATE INDEX t5x ON t5( json_extract(y, '$.x') );
  CREATE INDEX t5y ON t5( json_extract(y, '$.y') DESC );
}

do_index_check_test 5.1.1 t5x {
  {} NULL,4 {} 1,1 {} 2,2 {} 3,3 {} 5,5
}

do_index_check_test 5.1.2 t5y {
  {} 5,5 {} 3,3 {} 2,2 {} 1,1 {} NULL,4
}

do_index_check_test 5.1.3 sqlite_autoindex_t5_1 {
  {} {'{"w":4, "z":4}',4} 
  {} {'{"x":1, "y":1}',1} 
  {} {'{"x":2, "y":2}',2} 
  {} {'{"x":3, "y":3}',3} 
  {} {'{"x":5, "y":5}',5}
}

do_test 5.2 {
  set tblroot [db one { SELECT rootpage FROM sqlite_master WHERE name='t5' }]
  sqlite3_imposter db main $tblroot \
      {CREATE TABLE xt5(a INTEGER PRIMARY KEY, c1 TEXT);}
  db eval {
    UPDATE xt5 SET c1='{"x":22, "y":11}' WHERE rowid=1;
    DELETE FROM xt5 WHERE rowid = 4;
  }
  sqlite3_imposter db main
} {}

do_index_check_test 5.3.1 t5x {
  {row missing} NULL,4 
  {row data mismatch} 1,1 
  {} 2,2 
  {} 3,3 
  {} 5,5
}

do_index_check_test 5.3.2 sqlite_autoindex_t5_1 {
  {row missing} {'{"w":4, "z":4}',4} 
  {row data mismatch} {'{"x":1, "y":1}',1} 
  {} {'{"x":2, "y":2}',2} 
  {} {'{"x":3, "y":3}',3} 
  {} {'{"x":5, "y":5}',5}
}

#-------------------------------------------------------------------------
#
do_execsql_test 6.0 {
  CREATE TABLE t6(x INTEGER PRIMARY KEY, y, z);
  CREATE INDEX t6x1 ON t6(y, /* one,two,three */ z);
  CREATE INDEX t6x2 ON t6(z, -- hello,world,
  y);

  CREATE INDEX t6x3 ON t6(z -- hello,world
  , y);

  INSERT INTO t6 VALUES(1, 2, 3);
  INSERT INTO t6 VALUES(4, 5, 6);
}

do_index_check_test 6.1 t6x1 {
  {} 2,3,1 
  {} 5,6,4
}
do_index_check_test 6.2 t6x2 {
  {} 3,2,1 
  {} 6,5,4
}
do_index_check_test 6.2 t6x3 {
  {} 3,2,1 
  {} 6,5,4
}

#-------------------------------------------------------------------------
#
do_execsql_test 7.0 {
  CREATE TABLE t7(x INTEGER PRIMARY KEY, y, z);
  INSERT INTO t7 VALUES(1, 1, 1);
  INSERT INTO t7 VALUES(2, 2, 0);
  INSERT INTO t7 VALUES(3, 3, 1);
  INSERT INTO t7 VALUES(4, 4, 0);

  CREATE INDEX t7i1 ON t7(y) WHERE z=1;
  CREATE INDEX t7i2 ON t7(y) /* hello,world */ WHERE z=1;
  CREATE INDEX t7i3 ON t7(y) WHERE -- yep 
  z=1;
  CREATE INDEX t7i4 ON t7(y) WHERE z=1 -- yep;
}
do_index_check_test 7.1 t7i1 {
  {} 1,1 {} 3,3
}
do_index_check_test 7.2 t7i2 {
  {} 1,1 {} 3,3
}
do_index_check_test 7.3 t7i3 {
  {} 1,1 {} 3,3
}
do_index_check_test 7.4 t7i4 {
  {} 1,1 {} 3,3
}

# Run this script using
#
#       sqlite3_checker --test $thisscript $testscripts
#
# The $testscripts argument is optional.  If omitted, all *.test files
# in the same directory as $thisscript are run.
#
set NTEST 0
set NERR  0


# Invoke the do_test procedure to run a single test
#
# The $expected parameter is the expected result.  The result is the return
# value from the last TCL command in $cmd.
#
# Normally, $expected must match exactly.  But if $expected is of the form
# "/regexp/" then regular expression matching is used.  If $expected is
# "~/regexp/" then the regular expression must NOT match.  If $expected is
# of the form "#/value-list/" then each term in value-list must be numeric
# and must approximately match the corresponding numeric term in $result.
# Values must match within 10%.  Or if the $expected term is A..B then the
# $result term must be in between A and B.
#
proc do_test {name cmd expected} {
  if {[info exists ::testprefix]} {
    set name "$::testprefix$name"
  }

  incr ::NTEST
  puts -nonewline $name...
  flush stdout

  if {[catch {uplevel #0 "$cmd;\n"} result]} {
    puts -nonewline $name...
    puts "\nError: $result"
    incr ::NERR
  } else {
    set ok [expr {[string compare $result $expected]==0}]
    if {!$ok} {
      puts "\n!  $name expected: \[$expected\]\n! $name got:      \[$result\]"
      incr ::NERR
    } else {
      puts " Ok"
    }
  }
  flush stdout
}

#
#   do_execsql_test TESTNAME SQL RES
#
proc do_execsql_test {testname sql {result {}}} {
  uplevel [list do_test $testname [list db eval $sql] [list {*}$result]]
}

if {[llength $argv]==0} {
  set dir [file dirname $argv0]
  set argv [glob -nocomplain $dir/*.test]
}
foreach testfile $argv {
  file delete -force test.db
  sqlite3 db test.db
  source $testfile
  catch {db close}
}
puts "$NERR errors out of $NTEST tests"

#define RTREE_REINSERT(p) RTREE_MINCELLS(p)
#define RTREE_MAXCELLS 51

/*
** The smallest possible node-size is (512-64)==448 bytes. And the largest
** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).
** Therefore all non-root nodes must contain at least 3 entries. Since 
** 2^40 is greater than 2^64, an r-tree structure always has a depth of
** 40 or less.
*/
#define RTREE_MAX_DEPTH 40


/*
** Number of entries in the cursor RtreeNode cache.  The first entry is
................................................................................
  ){
    sqlite3_result_error(ctx, "Invalid argument to rtreedepth()", -1); 
  }else{
    u8 *zBlob = (u8 *)sqlite3_value_blob(apArg[0]);
    sqlite3_result_int(ctx, readInt16(zBlob));
  }
}










































































































































































































































































































































































































































































/*
** Register the r-tree module with database handle db. This creates the
** virtual table module "rtree" and the debugging/analysis scalar 
** function "rtreenode".
*/
int sqlite3RtreeInit(sqlite3 *db){
................................................................................
  const int utf8 = SQLITE_UTF8;
  int rc;

  rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
  }



  if( rc==SQLITE_OK ){
#ifdef SQLITE_RTREE_INT_ONLY
    void *c = (void *)RTREE_COORD_INT32;
#else
    void *c = (void *)RTREE_COORD_REAL32;
#endif
    rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);

#define RTREE_REINSERT(p) RTREE_MINCELLS(p)
#define RTREE_MAXCELLS 51

/*
** The smallest possible node-size is (512-64)==448 bytes. And the largest
** supported cell size is 48 bytes (8 byte rowid + ten 4 byte coordinates).
** Therefore all non-root nodes must contain at least 3 entries. Since 
** 3^40 is greater than 2^64, an r-tree structure always has a depth of
** 40 or less.
*/
#define RTREE_MAX_DEPTH 40


/*
** Number of entries in the cursor RtreeNode cache.  The first entry is
................................................................................
  ){
    sqlite3_result_error(ctx, "Invalid argument to rtreedepth()", -1); 
  }else{
    u8 *zBlob = (u8 *)sqlite3_value_blob(apArg[0]);
    sqlite3_result_int(ctx, readInt16(zBlob));
  }
}

/*
** Context object passed between the various routines that make up the
** implementation of integrity-check function rtreecheck().
*/
typedef struct RtreeCheck RtreeCheck;
struct RtreeCheck {
  sqlite3 *db;                    /* Database handle */
  const char *zDb;                /* Database containing rtree table */
  const char *zTab;               /* Name of rtree table */
  int bInt;                       /* True for rtree_i32 table */
  int nDim;                       /* Number of dimensions for this rtree tbl */
  sqlite3_stmt *pGetNode;         /* Statement used to retrieve nodes */
  sqlite3_stmt *aCheckMapping[2]; /* Statements to query %_parent/%_rowid */
  int nLeaf;                      /* Number of leaf cells in table */
  int nNonLeaf;                   /* Number of non-leaf cells in table */
  int rc;                         /* Return code */
  char *zReport;                  /* Message to report */
  int nErr;                       /* Number of lines in zReport */
};

#define RTREE_CHECK_MAX_ERROR 100

/*
** Reset SQL statement pStmt. If the sqlite3_reset() call returns an error,
** and RtreeCheck.rc==SQLITE_OK, set RtreeCheck.rc to the error code.
*/
static void rtreeCheckReset(RtreeCheck *pCheck, sqlite3_stmt *pStmt){
  int rc = sqlite3_reset(pStmt);
  if( pCheck->rc==SQLITE_OK ) pCheck->rc = rc;
}

/*
** The second and subsequent arguments to this function are a format string
** and printf style arguments. This function formats the string and attempts
** to compile it as an SQL statement.
**
** If successful, a pointer to the new SQL statement is returned. Otherwise,
** NULL is returned and an error code left in RtreeCheck.rc.
*/
static sqlite3_stmt *rtreeCheckPrepare(
  RtreeCheck *pCheck,             /* RtreeCheck object */
  const char *zFmt, ...           /* Format string and trailing args */
){
  va_list ap;
  char *z;
  sqlite3_stmt *pRet = 0;

  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);

  if( pCheck->rc==SQLITE_OK ){
    if( z==0 ){
      pCheck->rc = SQLITE_NOMEM;
    }else{
      pCheck->rc = sqlite3_prepare_v2(pCheck->db, z, -1, &pRet, 0);
    }
  }

  sqlite3_free(z);
  va_end(ap);
  return pRet;
}

/*
** The second and subsequent arguments to this function are a printf()
** style format string and arguments. This function formats the string and
** appends it to the report being accumuated in pCheck.
*/
static void rtreeCheckAppendMsg(RtreeCheck *pCheck, const char *zFmt, ...){
  va_list ap;
  va_start(ap, zFmt);
  if( pCheck->rc==SQLITE_OK && pCheck->nErr<RTREE_CHECK_MAX_ERROR ){
    char *z = sqlite3_vmprintf(zFmt, ap);
    if( z==0 ){
      pCheck->rc = SQLITE_NOMEM;
    }else{
      pCheck->zReport = sqlite3_mprintf("%z%s%z", 
          pCheck->zReport, (pCheck->zReport ? "\n" : ""), z
      );
      if( pCheck->zReport==0 ){
        pCheck->rc = SQLITE_NOMEM;
      }
    }
    pCheck->nErr++;
  }
  va_end(ap);
}

/*
** This function is a no-op if there is already an error code stored
** in the RtreeCheck object indicated by the first argument. NULL is
** returned in this case.
**
** Otherwise, the contents of rtree table node iNode are loaded from
** the database and copied into a buffer obtained from sqlite3_malloc().
** If no error occurs, a pointer to the buffer is returned and (*pnNode)
** is set to the size of the buffer in bytes.
**
** Or, if an error does occur, NULL is returned and an error code left
** in the RtreeCheck object. The final value of *pnNode is undefined in
** this case.
*/
static u8 *rtreeCheckGetNode(RtreeCheck *pCheck, i64 iNode, int *pnNode){
  u8 *pRet = 0;                   /* Return value */

  assert( pCheck->rc==SQLITE_OK );
  if( pCheck->pGetNode==0 ){
    pCheck->pGetNode = rtreeCheckPrepare(pCheck,
        "SELECT data FROM %Q.'%q_node' WHERE nodeno=?", 
        pCheck->zDb, pCheck->zTab
    );
  }

  if( pCheck->rc==SQLITE_OK ){
    sqlite3_bind_int64(pCheck->pGetNode, 1, iNode);
    if( sqlite3_step(pCheck->pGetNode)==SQLITE_ROW ){
      int nNode = sqlite3_column_bytes(pCheck->pGetNode, 0);
      const u8 *pNode = (const u8*)sqlite3_column_blob(pCheck->pGetNode, 0);
      pRet = sqlite3_malloc(nNode);
      if( pRet==0 ){
        pCheck->rc = SQLITE_NOMEM;
      }else{
        memcpy(pRet, pNode, nNode);
        *pnNode = nNode;
      }
    }
    rtreeCheckReset(pCheck, pCheck->pGetNode);
    if( pCheck->rc==SQLITE_OK && pRet==0 ){
      rtreeCheckAppendMsg(pCheck, "Node %lld missing from database", iNode);
    }
  }

  return pRet;
}

/*
** This function is used to check that the %_parent (if bLeaf==0) or %_rowid
** (if bLeaf==1) table contains a specified entry. The schemas of the
** two tables are:
**
**   CREATE TABLE %_parent(nodeno INTEGER PRIMARY KEY, parentnode INTEGER)
**   CREATE TABLE %_rowid(rowid INTEGER PRIMARY KEY, nodeno INTEGER)
**
** In both cases, this function checks that there exists an entry with
** IPK value iKey and the second column set to iVal.
**
*/
static void rtreeCheckMapping(
  RtreeCheck *pCheck,             /* RtreeCheck object */
  int bLeaf,                      /* True for a leaf cell, false for interior */
  i64 iKey,                       /* Key for mapping */
  i64 iVal                        /* Expected value for mapping */
){
  int rc;
  sqlite3_stmt *pStmt;
  const char *azSql[2] = {
    "SELECT parentnode FROM %Q.'%q_parent' WHERE nodeno=?",
    "SELECT nodeno FROM %Q.'%q_rowid' WHERE rowid=?"
  };

  assert( bLeaf==0 || bLeaf==1 );
  if( pCheck->aCheckMapping[bLeaf]==0 ){
    pCheck->aCheckMapping[bLeaf] = rtreeCheckPrepare(pCheck,
        azSql[bLeaf], pCheck->zDb, pCheck->zTab
    );
  }
  if( pCheck->rc!=SQLITE_OK ) return;

  pStmt = pCheck->aCheckMapping[bLeaf];
  sqlite3_bind_int64(pStmt, 1, iKey);
  rc = sqlite3_step(pStmt);
  if( rc==SQLITE_DONE ){
    rtreeCheckAppendMsg(pCheck, "Mapping (%lld -> %lld) missing from %s table",
        iKey, iVal, (bLeaf ? "%_rowid" : "%_parent")
    );
  }else if( rc==SQLITE_ROW ){
    i64 ii = sqlite3_column_int64(pStmt, 0);
    if( ii!=iVal ){
      rtreeCheckAppendMsg(pCheck, 
          "Found (%lld -> %lld) in %s table, expected (%lld -> %lld)",
          iKey, ii, (bLeaf ? "%_rowid" : "%_parent"), iKey, iVal
      );
    }
  }
  rtreeCheckReset(pCheck, pStmt);
}

/*
** Argument pCell points to an array of coordinates stored on an rtree page.
** This function checks that the coordinates are internally consistent (no
** x1>x2 conditions) and adds an error message to the RtreeCheck object
** if they are not.
**
** Additionally, if pParent is not NULL, then it is assumed to point to
** the array of coordinates on the parent page that bound the page 
** containing pCell. In this case it is also verified that the two
** sets of coordinates are mutually consistent and an error message added
** to the RtreeCheck object if they are not.
*/
static void rtreeCheckCellCoord(
  RtreeCheck *pCheck, 
  i64 iNode,                      /* Node id to use in error messages */
  int iCell,                      /* Cell number to use in error messages */
  u8 *pCell,                      /* Pointer to cell coordinates */
  u8 *pParent                     /* Pointer to parent coordinates */
){
  RtreeCoord c1, c2;
  RtreeCoord p1, p2;
  int i;

  for(i=0; i<pCheck->nDim; i++){
    readCoord(&pCell[4*2*i], &c1);
    readCoord(&pCell[4*(2*i + 1)], &c2);

    /* printf("%e, %e\n", c1.u.f, c2.u.f); */
    if( pCheck->bInt ? c1.i>c2.i : c1.f>c2.f ){
      rtreeCheckAppendMsg(pCheck, 
          "Dimension %d of cell %d on node %lld is corrupt", i, iCell, iNode
      );
    }

    if( pParent ){
      readCoord(&pParent[4*2*i], &p1);
      readCoord(&pParent[4*(2*i + 1)], &p2);

      if( (pCheck->bInt ? c1.i<p1.i : c1.f<p1.f) 
       || (pCheck->bInt ? c2.i>p2.i : c2.f>p2.f)
      ){
        rtreeCheckAppendMsg(pCheck, 
            "Dimension %d of cell %d on node %lld is corrupt relative to parent"
            , i, iCell, iNode
        );
      }
    }
  }
}

/*
** Run rtreecheck() checks on node iNode, which is at depth iDepth within
** the r-tree structure. Argument aParent points to the array of coordinates
** that bound node iNode on the parent node.
**
** If any problems are discovered, an error message is appended to the
** report accumulated in the RtreeCheck object.
*/
static void rtreeCheckNode(
  RtreeCheck *pCheck,
  int iDepth,                     /* Depth of iNode (0==leaf) */
  u8 *aParent,                    /* Buffer containing parent coords */
  i64 iNode                       /* Node to check */
){
  u8 *aNode = 0;
  int nNode = 0;

  assert( iNode==1 || aParent!=0 );
  assert( pCheck->nDim>0 );

  aNode = rtreeCheckGetNode(pCheck, iNode, &nNode);
  if( aNode ){
    if( nNode<4 ){
      rtreeCheckAppendMsg(pCheck, 
          "Node %lld is too small (%d bytes)", iNode, nNode
      );
    }else{
      int nCell;                  /* Number of cells on page */
      int i;                      /* Used to iterate through cells */
      if( aParent==0 ){
        iDepth = readInt16(aNode);
        if( iDepth>RTREE_MAX_DEPTH ){
          rtreeCheckAppendMsg(pCheck, "Rtree depth out of range (%d)", iDepth);
          sqlite3_free(aNode);
          return;
        }
      }
      nCell = readInt16(&aNode[2]);
      if( (4 + nCell*(8 + pCheck->nDim*2*4))>nNode ){
        rtreeCheckAppendMsg(pCheck, 
            "Node %lld is too small for cell count of %d (%d bytes)", 
            iNode, nCell, nNode
        );
      }else{
        for(i=0; i<nCell; i++){
          u8 *pCell = &aNode[4 + i*(8 + pCheck->nDim*2*4)];
          i64 iVal = readInt64(pCell);
          rtreeCheckCellCoord(pCheck, iNode, i, &pCell[8], aParent);

          if( iDepth>0 ){
            rtreeCheckMapping(pCheck, 0, iVal, iNode);
            rtreeCheckNode(pCheck, iDepth-1, &pCell[8], iVal);
            pCheck->nNonLeaf++;
          }else{
            rtreeCheckMapping(pCheck, 1, iVal, iNode);
            pCheck->nLeaf++;
          }
        }
      }
    }
    sqlite3_free(aNode);
  }
}

/*
** The second argument to this function must be either "_rowid" or
** "_parent". This function checks that the number of entries in the
** %_rowid or %_parent table is exactly nExpect. If not, it adds
** an error message to the report in the RtreeCheck object indicated
** by the first argument.
*/
static void rtreeCheckCount(RtreeCheck *pCheck, const char *zTbl, i64 nExpect){
  if( pCheck->rc==SQLITE_OK ){
    sqlite3_stmt *pCount;
    pCount = rtreeCheckPrepare(pCheck, "SELECT count(*) FROM %Q.'%q%s'",
        pCheck->zDb, pCheck->zTab, zTbl
    );
    if( pCount ){
      if( sqlite3_step(pCount)==SQLITE_ROW ){
        i64 nActual = sqlite3_column_int64(pCount, 0);
        if( nActual!=nExpect ){
          rtreeCheckAppendMsg(pCheck, "Wrong number of entries in %%%s table"
              " - expected %lld, actual %lld" , zTbl, nExpect, nActual
          );
        }
      }
      pCheck->rc = sqlite3_finalize(pCount);
    }
  }
}

/*
** This function does the bulk of the work for the rtree integrity-check.
** It is called by rtreecheck(), which is the SQL function implementation.
*/
static int rtreeCheckTable(
  sqlite3 *db,                    /* Database handle to access db through */
  const char *zDb,                /* Name of db ("main", "temp" etc.) */
  const char *zTab,               /* Name of rtree table to check */
  char **pzReport                 /* OUT: sqlite3_malloc'd report text */
){
  RtreeCheck check;               /* Common context for various routines */
  sqlite3_stmt *pStmt = 0;        /* Used to find column count of rtree table */
  int bEnd = 0;                   /* True if transaction should be closed */

  /* Initialize the context object */
  memset(&check, 0, sizeof(check));
  check.db = db;
  check.zDb = zDb;
  check.zTab = zTab;

  /* If there is not already an open transaction, open one now. This is
  ** to ensure that the queries run as part of this integrity-check operate
  ** on a consistent snapshot.  */
  if( sqlite3_get_autocommit(db) ){
    check.rc = sqlite3_exec(db, "BEGIN", 0, 0, 0);
    bEnd = 1;
  }

  /* Find number of dimensions in the rtree table. */
  pStmt = rtreeCheckPrepare(&check, "SELECT * FROM %Q.%Q", zDb, zTab);
  if( pStmt ){
    int rc;
    check.nDim = (sqlite3_column_count(pStmt) - 1) / 2;
    if( check.nDim<1 ){
      rtreeCheckAppendMsg(&check, "Schema corrupt or not an rtree");
    }else if( SQLITE_ROW==sqlite3_step(pStmt) ){
      check.bInt = (sqlite3_column_type(pStmt, 1)==SQLITE_INTEGER);
    }
    rc = sqlite3_finalize(pStmt);
    if( rc!=SQLITE_CORRUPT ) check.rc = rc;
  }

  /* Do the actual integrity-check */
  if( check.nDim>=1 ){
    if( check.rc==SQLITE_OK ){
      rtreeCheckNode(&check, 0, 0, 1);
    }
    rtreeCheckCount(&check, "_rowid", check.nLeaf);
    rtreeCheckCount(&check, "_parent", check.nNonLeaf);
  }

  /* Finalize SQL statements used by the integrity-check */
  sqlite3_finalize(check.pGetNode);
  sqlite3_finalize(check.aCheckMapping[0]);
  sqlite3_finalize(check.aCheckMapping[1]);

  /* If one was opened, close the transaction */
  if( bEnd ){
    int rc = sqlite3_exec(db, "END", 0, 0, 0);
    if( check.rc==SQLITE_OK ) check.rc = rc;
  }
  *pzReport = check.zReport;
  return check.rc;
}

/*
** Usage:
**
**   rtreecheck(<rtree-table>);
**   rtreecheck(<database>, <rtree-table>);
**
** Invoking this SQL function runs an integrity-check on the named rtree
** table. The integrity-check verifies the following:
**
**   1. For each cell in the r-tree structure (%_node table), that:
**
**       a) for each dimension, (coord1 <= coord2).
**
**       b) unless the cell is on the root node, that the cell is bounded
**          by the parent cell on the parent node.
**
**       c) for leaf nodes, that there is an entry in the %_rowid 
**          table corresponding to the cell's rowid value that 
**          points to the correct node.
**
**       d) for cells on non-leaf nodes, that there is an entry in the 
**          %_parent table mapping from the cell's child node to the
**          node that it resides on.
**
**   2. That there are the same number of entries in the %_rowid table
**      as there are leaf cells in the r-tree structure, and that there
**      is a leaf cell that corresponds to each entry in the %_rowid table.
**
**   3. That there are the same number of entries in the %_parent table
**      as there are non-leaf cells in the r-tree structure, and that 
**      there is a non-leaf cell that corresponds to each entry in the 
**      %_parent table.
*/
static void rtreecheck(
  sqlite3_context *ctx, 
  int nArg, 
  sqlite3_value **apArg
){
  if( nArg!=1 && nArg!=2 ){
    sqlite3_result_error(ctx, 
        "wrong number of arguments to function rtreecheck()", -1
    );
  }else{
    int rc;
    char *zReport = 0;
    const char *zDb = (const char*)sqlite3_value_text(apArg[0]);
    const char *zTab;
    if( nArg==1 ){
      zTab = zDb;
      zDb = "main";
    }else{
      zTab = (const char*)sqlite3_value_text(apArg[1]);
    }
    rc = rtreeCheckTable(sqlite3_context_db_handle(ctx), zDb, zTab, &zReport);
    if( rc==SQLITE_OK ){
      sqlite3_result_text(ctx, zReport ? zReport : "ok", -1, SQLITE_TRANSIENT);
    }else{
      sqlite3_result_error_code(ctx, rc);
    }
    sqlite3_free(zReport);
  }
}


/*
** Register the r-tree module with database handle db. This creates the
** virtual table module "rtree" and the debugging/analysis scalar 
** function "rtreenode".
*/
int sqlite3RtreeInit(sqlite3 *db){
................................................................................
  const int utf8 = SQLITE_UTF8;
  int rc;

  rc = sqlite3_create_function(db, "rtreenode", 2, utf8, 0, rtreenode, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "rtreedepth", 1, utf8, 0,rtreedepth, 0, 0);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "rtreecheck", -1, utf8, 0,rtreecheck, 0,0);
  }
  if( rc==SQLITE_OK ){
#ifdef SQLITE_RTREE_INT_ONLY
    void *c = (void *)RTREE_COORD_INT32;
#else
    void *c = (void *)RTREE_COORD_REAL32;
#endif
    rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);

    set res(1) {1 {UNIQUE constraint failed: t1.idx}}
    set res(2) {1 {rtree constraint failed: t1.(x1<=x2)}}

    do_catchsql_test $testname.1 $sql $res($error)
    do_test $testname.2 [list sql_uses_stmt db $sql] $uses
    do_execsql_test $testname.3 { SELECT * FROM t1 ORDER BY idx } $data

    do_test $testname.4 { rtree_check db t1 } 0
    db close
  }
}

#-------------------------------------------------------------------------
# Test that bug [d2889096e7bdeac6d] has been fixed.
#

    set res(1) {1 {UNIQUE constraint failed: t1.idx}}
    set res(2) {1 {rtree constraint failed: t1.(x1<=x2)}}

    do_catchsql_test $testname.1 $sql $res($error)
    do_test $testname.2 [list sql_uses_stmt db $sql] $uses
    do_execsql_test $testname.3 { SELECT * FROM t1 ORDER BY idx } $data

    do_rtree_integrity_test $testname.4 t1
    db close
  }
}

#-------------------------------------------------------------------------
# Test that bug [d2889096e7bdeac6d] has been fixed.
#

      if {$rc != 1} {
        puts $t1
        puts $t2
      }
      set rc
    } {1}
  
    do_test rtree2-$module.$nDim.3 {
      rtree_check db t1
    } 0
  
    set OPS [list < > <= >= =]
    for {set ii 0} {$ii < $::NSELECT} {incr ii} {
      do_test rtree2-$module.$nDim.4.$ii.1 {
        set where [list]
        foreach look_three_dots! {. . .} {
          set colidx [expr int(rand()*($nDim*2+1))-1]
................................................................................
        set rc [expr {$t1 eq $t2}]
        if {$rc != 1} {
          puts $t1
          puts $t2
        }
        set rc
      } {1}
      do_test rtree2-$module.$nDim.5.$ii.2 {
        rtree_check db t1
      } {0}
    }
  
    do_test rtree2-$module.$nDim.6 {
      execsql {
        DROP TABLE t1;
        DROP TABLE t2;
      }
    } {}
  }
}

finish_test

      if {$rc != 1} {
        puts $t1
        puts $t2
      }
      set rc
    } {1}
  
    do_rtree_integrity_test rtree2-$module.$nDim.3 t1


  
    set OPS [list < > <= >= =]
    for {set ii 0} {$ii < $::NSELECT} {incr ii} {
      do_test rtree2-$module.$nDim.4.$ii.1 {
        set where [list]
        foreach look_three_dots! {. . .} {
          set colidx [expr int(rand()*($nDim*2+1))-1]
................................................................................
        set rc [expr {$t1 eq $t2}]
        if {$rc != 1} {
          puts $t1
          puts $t2
        }
        set rc
      } {1}
      do_rtree_integrity_test rtree2-$module.$nDim.5.$ii.2 t1


    }
  
    do_test rtree2-$module.$nDim.6 {
      execsql {
        DROP TABLE t1;
        DROP TABLE t2;
      }
    } {}
  }
}

finish_test

#
# Randomized test cases for the rtree extension.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

................................................................................
    }
    set where "WHERE [join [scramble $where] { AND }]"
    do_test rtree4-$nDim.2.$i.8 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]
  }


}

finish_test

#
# Randomized test cases for the rtree extension.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

................................................................................
    }
    set where "WHERE [join [scramble $where] { AND }]"
    do_test rtree4-$nDim.2.$i.8 {
      list $where [db eval "SELECT id FROM rx $where ORDER BY id"]
    } [list $where [db eval "SELECT id FROM bx $where ORDER BY id"]]
  }

  do_rtree_integrity_test rtree4-$nDim.3 rx
}

finish_test

# The focus of this file is testing the r-tree extension when it is
# configured to store values as 32 bit integers.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

................................................................................
do_test rtree5-1.13 { 
  execsql { 
    SELECT * FROM t1 WHERE 
        x1=2147483643 AND x2=2147483647 AND 
        y1=-2147483648 AND y2=-2147483643
  }
} {2 2147483643 2147483647 -2147483648 -2147483643}


finish_test

# The focus of this file is testing the r-tree extension when it is
# configured to store values as 32 bit integers.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl

ifcapable !rtree {
  finish_test
  return
}

................................................................................
do_test rtree5-1.13 { 
  execsql { 
    SELECT * FROM t1 WHERE 
        x1=2147483643 AND x2=2147483647 AND 
        y1=-2147483648 AND y2=-2147483643
  }
} {2 2147483643 2147483647 -2147483648 -2147483643}
do_rtree_integrity_test rtree5-1.14 t1

finish_test

# database page-size is modified. At one point (3.6.22), this was causing
# malfunctions.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl

ifcapable !rtree||!vacuum {
  finish_test
  return
}

................................................................................
do_test rtree7-1.5 {
  execsql_intout { 
    PRAGMA page_size = 512;
    VACUUM;
    SELECT sum(x1), sum(x2), sum(y1), sum(y2) FROM rt
  }
} {51 102 153 204}



finish_test

# database page-size is modified. At one point (3.6.22), this was causing
# malfunctions.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl

ifcapable !rtree||!vacuum {
  finish_test
  return
}

................................................................................
do_test rtree7-1.5 {
  execsql_intout { 
    PRAGMA page_size = 512;
    VACUUM;
    SELECT sum(x1), sum(x2), sum(y1), sum(y2) FROM rt
  }
} {51 102 153 204}

do_rtree_integrity_test rtree7-1.6 rt

finish_test

#***********************************************************************
# 
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

#-------------------------------------------------------------------------
# The following block of tests - rtree8-1.* - feature reading and writing
# an r-tree table while there exist open cursors on it.
#
................................................................................
do_test rtree8-1.2.2 { nested_select 1 } {51}

# This test runs many SELECT queries simultaneously against a large 
# table, causing a collision in the hash-table used to store r-tree 
# nodes internally.
#
populate_t1 1500

do_execsql_test rtree8-1.3.1 { SELECT max(nodeno) FROM t1_node } {164}
do_test rtree8-1.3.2 {
  set rowids [execsql {SELECT min(rowid) FROM t1_rowid GROUP BY nodeno}]
  set stmt_list [list]
  foreach row $rowids {
    set stmt [sqlite3_prepare db "SELECT * FROM t1 WHERE id = $row" -1 tail]
    sqlite3_step $stmt
................................................................................
    execsql { INSERT INTO t2 VALUES($i, 100, 101) }
  }
  for {set i 100} {$i < 200} {incr i} {
    execsql { INSERT INTO t2 VALUES($i, 1000, 1001) }
  }
  execsql COMMIT
} {}

do_test rtree8-5.3 {
  execsql BEGIN
  for {set i 0} {$i < 200} {incr i} {
    execsql { DELETE FROM t2 WHERE id = $i }
  }
  execsql COMMIT
} {}



finish_test

#***********************************************************************
# 
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

#-------------------------------------------------------------------------
# The following block of tests - rtree8-1.* - feature reading and writing
# an r-tree table while there exist open cursors on it.
#
................................................................................
do_test rtree8-1.2.2 { nested_select 1 } {51}

# This test runs many SELECT queries simultaneously against a large 
# table, causing a collision in the hash-table used to store r-tree 
# nodes internally.
#
populate_t1 1500
do_rtree_integrity_test rtree8-1.3.0 t1
do_execsql_test rtree8-1.3.1 { SELECT max(nodeno) FROM t1_node } {164}
do_test rtree8-1.3.2 {
  set rowids [execsql {SELECT min(rowid) FROM t1_rowid GROUP BY nodeno}]
  set stmt_list [list]
  foreach row $rowids {
    set stmt [sqlite3_prepare db "SELECT * FROM t1 WHERE id = $row" -1 tail]
    sqlite3_step $stmt
................................................................................
    execsql { INSERT INTO t2 VALUES($i, 100, 101) }
  }
  for {set i 100} {$i < 200} {incr i} {
    execsql { INSERT INTO t2 VALUES($i, 1000, 1001) }
  }
  execsql COMMIT
} {}
do_rtree_integrity_test rtree8-5.3 t2
do_test rtree8-5.4 {
  execsql BEGIN
  for {set i 0} {$i < 200} {incr i} {
    execsql { DELETE FROM t2 WHERE id = $i }
  }
  execsql COMMIT
} {}
do_rtree_integrity_test rtree8-5.5 t2


finish_test

# This file contains tests for the r-tree module. Specifically, it tests
# that custom r-tree queries (geometry callbacks) work.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }
ifcapable rtree_int_only { finish_test; return }

register_cube_geom db

do_execsql_test rtree9-1.1 {
................................................................................

for {set i 0} {$i < 1000} {incr i} {
  set x [expr $i%10]
  set y [expr ($i/10)%10]
  set z [expr ($i/100)%10]
  execsql { INSERT INTO rt VALUES($i, $x, $x+1, $y, $y+1, $z, $z+1) }
}

do_execsql_test rtree9-2.1 {
  SELECT id FROM rt WHERE id MATCH cube(2.5, 2.5, 2.5, 1, 1, 1) ORDER BY id;
} {222 223 232 233 322 323 332 333}
do_execsql_test rtree9-2.2 {
  SELECT id FROM rt WHERE id MATCH cube(5.5, 5.5, 5.5, 1, 1, 1) ORDER BY id;
} {555 556 565 566 655 656 665 666}


do_execsql_test rtree9-3.1 {
  CREATE VIRTUAL TABLE rt32 USING rtree_i32(id, x1, x2, y1, y2, z1, z2);
} {} 
for {set i 0} {$i < 1000} {incr i} {
  set x [expr $i%10]
  set y [expr ($i/10)%10]
  set z [expr ($i/100)%10]
  execsql { INSERT INTO rt32 VALUES($i, $x, $x+1, $y, $y+1, $z, $z+1) }
}

do_execsql_test rtree9-3.2 {
  SELECT id FROM rt32 WHERE id MATCH cube(3, 3, 3, 1, 1, 1) ORDER BY id;
} {222 223 224 232 233 234 242 243 244 322 323 324 332 333 334 342 343 344 422 423 424 432 433 434 442 443 444}
do_execsql_test rtree9-3.3 {
  SELECT id FROM rt32 WHERE id MATCH cube(5.5, 5.5, 5.5, 1, 1, 1) ORDER BY id;
} {555 556 565 566 655 656 665 666}

................................................................................
  SELECT id FROM rt2 WHERE id MATCH circle(0.0, 0.0, 2.0);
} {1 2 3 4 13 14 15 16 17}

do_execsql_test rtree9-5.3 {
  UPDATE rt2 SET xmin=xmin+5, ymin=ymin+5, xmax=xmax+5, ymax=ymax+5;
  SELECT id FROM rt2 WHERE id MATCH circle(5.0, 5.0, 2.0);
} {1 2 3 4 13 14 15 16 17}


finish_test

# This file contains tests for the r-tree module. Specifically, it tests
# that custom r-tree queries (geometry callbacks) work.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }
ifcapable rtree_int_only { finish_test; return }

register_cube_geom db

do_execsql_test rtree9-1.1 {
................................................................................

for {set i 0} {$i < 1000} {incr i} {
  set x [expr $i%10]
  set y [expr ($i/10)%10]
  set z [expr ($i/100)%10]
  execsql { INSERT INTO rt VALUES($i, $x, $x+1, $y, $y+1, $z, $z+1) }
}
do_rtree_integrity_test rtree9-2.0 rt
do_execsql_test rtree9-2.1 {
  SELECT id FROM rt WHERE id MATCH cube(2.5, 2.5, 2.5, 1, 1, 1) ORDER BY id;
} {222 223 232 233 322 323 332 333}
do_execsql_test rtree9-2.2 {
  SELECT id FROM rt WHERE id MATCH cube(5.5, 5.5, 5.5, 1, 1, 1) ORDER BY id;
} {555 556 565 566 655 656 665 666}


do_execsql_test rtree9-3.0 {
  CREATE VIRTUAL TABLE rt32 USING rtree_i32(id, x1, x2, y1, y2, z1, z2);
} {} 
for {set i 0} {$i < 1000} {incr i} {
  set x [expr $i%10]
  set y [expr ($i/10)%10]
  set z [expr ($i/100)%10]
  execsql { INSERT INTO rt32 VALUES($i, $x, $x+1, $y, $y+1, $z, $z+1) }
}
do_rtree_integrity_test rtree9-3.1 rt32
do_execsql_test rtree9-3.2 {
  SELECT id FROM rt32 WHERE id MATCH cube(3, 3, 3, 1, 1, 1) ORDER BY id;
} {222 223 224 232 233 234 242 243 244 322 323 324 332 333 334 342 343 344 422 423 424 432 433 434 442 443 444}
do_execsql_test rtree9-3.3 {
  SELECT id FROM rt32 WHERE id MATCH cube(5.5, 5.5, 5.5, 1, 1, 1) ORDER BY id;
} {555 556 565 566 655 656 665 666}

................................................................................
  SELECT id FROM rt2 WHERE id MATCH circle(0.0, 0.0, 2.0);
} {1 2 3 4 13 14 15 16 17}

do_execsql_test rtree9-5.3 {
  UPDATE rt2 SET xmin=xmin+5, ymin=ymin+5, xmax=xmax+5, ymax=ymax+5;
  SELECT id FROM rt2 WHERE id MATCH circle(5.0, 5.0, 2.0);
} {1 2 3 4 13 14 15 16 17}
do_rtree_integrity_test rtree9-5.4 rt2

finish_test

do_corruption_tests rtreeA-1.1 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
  4   "SELECT * FROM t1 WHERE x1<10 AND x2>12"
}







do_execsql_test  rtreeA-1.2.0 { DROP TABLE t1_node } {}
do_corruption_tests rtreeA-1.2 -error "database disk image is malformed" {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
  4   "SELECT * FROM t1 WHERE x1<10 AND x2>12"
}
................................................................................
do_test rtreeA-3.1.0.1 { set_tree_depth t1 } {1}
do_test rtreeA-3.1.0.2 { set_tree_depth t1 3 } {3}
do_corruption_tests rtreeA-3.1 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
}





do_test rtreeA-3.2.0 { set_tree_depth t1 1000 } {1000}
do_corruption_tests rtreeA-3.2 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
}
................................................................................
} {65535}
do_corruption_tests rtreeA-3.3 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
}







#-------------------------------------------------------------------------
# Set the "number of entries" field on some nodes incorrectly.
#
create_t1
populate_t1
do_test rtreeA-4.1.0 { 
  set_entry_count t1 1 4000
................................................................................
create_t1
populate_t1
do_execsql_test rtreeA-5.1.0 { DELETE FROM t1_parent } {}
do_corruption_tests rtreeA-5.1 {
  1   "DELETE FROM t1 WHERE rowid = 5"
  2   "DELETE FROM t1"
}





#-------------------------------------------------------------------------
# Add some bad entries to the %_parent table.
#
create_t1
populate_t1
do_execsql_test rtreeA-6.1.0 { 
  UPDATE t1_parent set parentnode = parentnode+1
} {}
do_corruption_tests rtreeA-6.1 {
  1   "DELETE FROM t1 WHERE rowid = 5"
  2   "UPDATE t1 SET x1=x1+1, x2=x2+1"
}





#-------------------------------------------------------------------------
# Truncated blobs in the _node table.
#
create_t1
populate_t1
sqlite3 db test.db
................................................................................
  SELECT * FROM t1 WHERE x1>0 AND x1<100 AND x2>0 AND x2<100;
} {1 {undersize RTree blobs in "t1_node"}}
do_test rtreeA-7.120 {
  sqlite3_extended_errcode db
} {SQLITE_CORRUPT_VTAB}



finish_test

do_corruption_tests rtreeA-1.1 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
  4   "SELECT * FROM t1 WHERE x1<10 AND x2>12"
}

do_execsql_test rtreeA-1.1.1 {
  SELECT rtreecheck('main', 't1')
} {{Node 1 missing from database
Wrong number of entries in %_rowid table - expected 0, actual 500
Wrong number of entries in %_parent table - expected 0, actual 23}}

do_execsql_test  rtreeA-1.2.0 { DROP TABLE t1_node } {}
do_corruption_tests rtreeA-1.2 -error "database disk image is malformed" {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
  4   "SELECT * FROM t1 WHERE x1<10 AND x2>12"
}
................................................................................
do_test rtreeA-3.1.0.1 { set_tree_depth t1 } {1}
do_test rtreeA-3.1.0.2 { set_tree_depth t1 3 } {3}
do_corruption_tests rtreeA-3.1 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
}

do_execsql_test rtreeA-3.1.0.3 {
  SELECT rtreecheck('main', 't1')!="ok"
} {1}

do_test rtreeA-3.2.0 { set_tree_depth t1 1000 } {1000}
do_corruption_tests rtreeA-3.2 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
}
................................................................................
} {65535}
do_corruption_tests rtreeA-3.3 {
  1   "SELECT * FROM t1"
  2   "SELECT * FROM t1 WHERE rowid=5"
  3   "INSERT INTO t1 VALUES(1000, 1, 2, 3, 4)"
}

do_execsql_test rtreeA-3.3.3.4 {
  SELECT rtreecheck('main', 't1')
} {{Rtree depth out of range (65535)
Wrong number of entries in %_rowid table - expected 0, actual 499
Wrong number of entries in %_parent table - expected 0, actual 23}}

#-------------------------------------------------------------------------
# Set the "number of entries" field on some nodes incorrectly.
#
create_t1
populate_t1
do_test rtreeA-4.1.0 { 
  set_entry_count t1 1 4000
................................................................................
create_t1
populate_t1
do_execsql_test rtreeA-5.1.0 { DELETE FROM t1_parent } {}
do_corruption_tests rtreeA-5.1 {
  1   "DELETE FROM t1 WHERE rowid = 5"
  2   "DELETE FROM t1"
}

do_execsql_test rtreeA-5.2 {
  SELECT rtreecheck('main', 't1')!="ok"
} {1}

#-------------------------------------------------------------------------
# Add some bad entries to the %_parent table.
#
create_t1
populate_t1
do_execsql_test rtreeA-6.1.0 { 
  UPDATE t1_parent set parentnode = parentnode+1
} {}
do_corruption_tests rtreeA-6.1 {
  1   "DELETE FROM t1 WHERE rowid = 5"
  2   "UPDATE t1 SET x1=x1+1, x2=x2+1"
}

do_execsql_test rtreeA-6.2 {
  SELECT rtreecheck('main', 't1')!="ok"
} {1}

#-------------------------------------------------------------------------
# Truncated blobs in the _node table.
#
create_t1
populate_t1
sqlite3 db test.db
................................................................................
  SELECT * FROM t1 WHERE x1>0 AND x1<100 AND x2>0 AND x2<100;
} {1 {undersize RTree blobs in "t1_node"}}
do_test rtreeA-7.120 {
  sqlite3_extended_errcode db
} {SQLITE_CORRUPT_VTAB}



finish_test

# Make sure the rtreenode() testing function can handle entries with
# 64-bit rowids.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

ifcapable rtree_int_only {
  do_test rtreeB-1.1-intonly {
    db eval {
      CREATE VIRTUAL TABLE t1 USING rtree(ii, x0, y0, x1, y1);
................................................................................
      INSERT INTO t1 VALUES(4294967296, 0.0, 0.0, 300.0, 300.0);
      INSERT INTO t1 VALUES(8589934592, 20.0, 20.0, 150.0, 150.0);
      INSERT INTO t1 VALUES(9223372036854775807, 150, 150, 400, 400);
      SELECT rtreenode(2, data) FROM t1_node;
    }
  } {{{1073741824 0 0 100 100} {2147483646 0 0 200 200} {4294967296 0 0 300 300} {8589934592 20 20 150 150} {9223372036854775807 150 150 400 400}}}
}



finish_test

# Make sure the rtreenode() testing function can handle entries with
# 64-bit rowids.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

ifcapable rtree_int_only {
  do_test rtreeB-1.1-intonly {
    db eval {
      CREATE VIRTUAL TABLE t1 USING rtree(ii, x0, y0, x1, y1);
................................................................................
      INSERT INTO t1 VALUES(4294967296, 0.0, 0.0, 300.0, 300.0);
      INSERT INTO t1 VALUES(8589934592, 20.0, 20.0, 150.0, 150.0);
      INSERT INTO t1 VALUES(9223372036854775807, 150, 150, 400, 400);
      SELECT rtreenode(2, data) FROM t1_node;
    }
  } {{{1073741824 0 0 100 100} {2147483646 0 0 200 200} {4294967296 0 0 300 300} {8589934592 20 20 150 150} {9223372036854775807 150 150 400 400}}}
}

do_rtree_integrity_test rtreeB-1.2 t1

finish_test

# Make sure the rtreenode() testing function can handle entries with
# 64-bit rowids.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }
set testprefix rtreeC

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE r_tree USING rtree(id, min_x, max_x, min_y, max_y);
  CREATE TABLE t(x, y);
................................................................................
  INSERT INTO t1(x) SELECT x+64 FROM t1;  -- 128
  INSERT INTO t1(x) SELECT x+128 FROM t1; -- 256
  INSERT INTO t1(x) SELECT x+256 FROM t1; -- 512
  INSERT INTO t1(x) SELECT x+512 FROM t1; --1024

  INSERT INTO rt SELECT x, x, x+1 FROM t1 WHERE x<=5;
}


# First test a query with no ANALYZE data at all. The outer loop is
# real table "t1".
#
do_eqp_test 5.2 {
  SELECT * FROM t1, rt WHERE x==id;
} {

# Make sure the rtreenode() testing function can handle entries with
# 64-bit rowids.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }
set testprefix rtreeC

do_execsql_test 1.0 {
  CREATE VIRTUAL TABLE r_tree USING rtree(id, min_x, max_x, min_y, max_y);
  CREATE TABLE t(x, y);
................................................................................
  INSERT INTO t1(x) SELECT x+64 FROM t1;  -- 128
  INSERT INTO t1(x) SELECT x+128 FROM t1; -- 256
  INSERT INTO t1(x) SELECT x+256 FROM t1; -- 512
  INSERT INTO t1(x) SELECT x+512 FROM t1; --1024

  INSERT INTO rt SELECT x, x, x+1 FROM t1 WHERE x<=5;
}
do_rtree_integrity_test 5.1.1 rt

# First test a query with no ANALYZE data at all. The outer loop is
# real table "t1".
#
do_eqp_test 5.2 {
  SELECT * FROM t1, rt WHERE x==id;
} {

# This file contains tests for the r-tree module. Specifically, it tests
# that new-style custom r-tree queries (geometry callbacks) work.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }
ifcapable rtree_int_only { finish_test; return }


#-------------------------------------------------------------------------
# Test the example 2d "circle" geometry callback.
#
register_circle_geom db

do_execsql_test rtreeE-1.1 {
  PRAGMA page_size=512;
  CREATE VIRTUAL TABLE rt1 USING rtree(id,x0,x1,y0,y1);
  
  /* A tight pattern of small boxes near 0,0 */
  WITH RECURSIVE
    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
................................................................................

  /* A looser pattern of larger boxes near 0, 200 */
  WITH RECURSIVE
    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
  INSERT INTO rt1 SELECT 200+x+5*y, x*7, x*7+15, y*7+200, y*7+215 FROM x, y;
} {}


# Queries against each of the three clusters */
do_execsql_test rtreeE-1.1 {
  SELECT id FROM rt1 WHERE id MATCH Qcircle(0.0, 0.0, 50.0, 3) ORDER BY id;
} {0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24}
do_execsql_test rtreeE-1.1x {
  SELECT id FROM rt1 WHERE id MATCH Qcircle('x:0 y:0 r:50.0 e:3') ORDER BY id;
................................................................................
    db eval {INSERT INTO t2 VALUES($id,$x0,$x1,$y0,$y1)}
  }
  db eval {
    INSERT INTO rt2 SELECT * FROM t2;
    COMMIT;
  }
} {}


for {set i 1} {$i<=200} {incr i} {
  set dx [expr {int(rand()*100)}]
  set dy [expr {int(rand()*100)}]
  set x0 [expr {int(rand()*(10000 - $dx))}]
  set x1 [expr {$x0+$dx}]
  set y0 [expr {int(rand()*(10000 - $dy))}]

# This file contains tests for the r-tree module. Specifically, it tests
# that new-style custom r-tree queries (geometry callbacks) work.
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }
ifcapable rtree_int_only { finish_test; return }


#-------------------------------------------------------------------------
# Test the example 2d "circle" geometry callback.
#
register_circle_geom db

do_execsql_test rtreeE-1.0.0 {
  PRAGMA page_size=512;
  CREATE VIRTUAL TABLE rt1 USING rtree(id,x0,x1,y0,y1);
  
  /* A tight pattern of small boxes near 0,0 */
  WITH RECURSIVE
    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
................................................................................

  /* A looser pattern of larger boxes near 0, 200 */
  WITH RECURSIVE
    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
  INSERT INTO rt1 SELECT 200+x+5*y, x*7, x*7+15, y*7+200, y*7+215 FROM x, y;
} {}
do_rtree_integrity_test rtreeE-1.0.1 rt1

# Queries against each of the three clusters */
do_execsql_test rtreeE-1.1 {
  SELECT id FROM rt1 WHERE id MATCH Qcircle(0.0, 0.0, 50.0, 3) ORDER BY id;
} {0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24}
do_execsql_test rtreeE-1.1x {
  SELECT id FROM rt1 WHERE id MATCH Qcircle('x:0 y:0 r:50.0 e:3') ORDER BY id;
................................................................................
    db eval {INSERT INTO t2 VALUES($id,$x0,$x1,$y0,$y1)}
  }
  db eval {
    INSERT INTO rt2 SELECT * FROM t2;
    COMMIT;
  }
} {}
do_rtree_integrity_test rtreeE-2.1.1 rt2

for {set i 1} {$i<=200} {incr i} {
  set dx [expr {int(rand()*100)}]
  set dy [expr {int(rand()*100)}]
  set x0 [expr {int(rand()*(10000 - $dx))}]
  set x1 [expr {$x0+$dx}]
  set y0 [expr {int(rand()*(10000 - $dy))}]

#     END;
#     DELETE FROM t2 WHERE y=1;
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

do_execsql_test rtreeF-1.1 {
  CREATE TABLE t1(x);
  CREATE TABLE t2(y);
  CREATE VIRTUAL TABLE t3 USING rtree(a,b,c);
................................................................................
do_execsql_test rtreeF-1.5 {
  DELETE FROM t2 WHERE y=2;

  SELECT a FROM t3 ORDER BY a;
  SELECT '|';
  SELECT y FROM t2 ORDER BY y;
} {1 4 5 | 1 4}



finish_test

#     END;
#     DELETE FROM t2 WHERE y=1;
# 

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

do_execsql_test rtreeF-1.1 {
  CREATE TABLE t1(x);
  CREATE TABLE t2(y);
  CREATE VIRTUAL TABLE t3 USING rtree(a,b,c);
................................................................................
do_execsql_test rtreeF-1.5 {
  DELETE FROM t2 WHERE y=2;

  SELECT a FROM t3 ORDER BY a;
  SELECT '|';
  SELECT y FROM t2 ORDER BY y;
} {1 4 5 | 1 4}

do_rtree_integrity_test rtreeF-1.6 t3

finish_test

# This file contains tests for the r-tree module.
#
# Verify that no invalid SQL is run during initialization

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 

source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

db close
sqlite3_shutdown
test_sqlite3_log [list lappend ::log]
set ::log [list]
................................................................................
  set ::log
} {}

do_execsql_test rtreeG-1.2 {
  INSERT INTO t1 VALUES(1,10,15,5,23),(2,20,21,5,23),(3,10,15,20,30);
  SELECT id from t1 WHERE x0>8 AND x1<16 AND y0>2 AND y1<25;
} {1}

do_test rtreeG-1.2log {
  set ::log
} {}

db close
sqlite3 db test.db
do_execsql_test rtreeG-1.3 {

# This file contains tests for the r-tree module.
#
# Verify that no invalid SQL is run during initialization

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] rtree_util.tcl]
source $testdir/tester.tcl
ifcapable !rtree { finish_test ; return }

db close
sqlite3_shutdown
test_sqlite3_log [list lappend ::log]
set ::log [list]
................................................................................
  set ::log
} {}

do_execsql_test rtreeG-1.2 {
  INSERT INTO t1 VALUES(1,10,15,5,23),(2,20,21,5,23),(3,10,15,20,30);
  SELECT id from t1 WHERE x0>8 AND x1<16 AND y0>2 AND y1<25;
} {1}
do_rtree_integrity_test rtreeG-1.2.integrity t1
do_test rtreeG-1.2log {
  set ::log
} {}

db close
sqlite3 db test.db
do_execsql_test rtreeG-1.3 {

  set ret
}

proc rtree_treedump {db zTab} {
  set d [rtree_depth $db $zTab]
  rtree_nodetreedump $db $zTab "" $d 1
}

  set ret
}

proc rtree_treedump {db zTab} {
  set d [rtree_depth $db $zTab]
  rtree_nodetreedump $db $zTab "" $d 1
}

proc do_rtree_integrity_test {tn tbl} {
  uplevel [list do_execsql_test $tn "SELECT rtreecheck('$tbl')" ok]
}

# 2017 August 17
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
#


if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl
set testprefix rtreecheck

ifcapable !rtree {
  finish_test
  return
}

proc swap_int32 {blob i0 i1} {
  binary scan $blob I* L

  set a [lindex $L $i0]
  set b [lindex $L $i1]

  lset L $i0 $b
  lset L $i1 $a

  binary format I* $L
}

proc set_int32 {blob idx val} {
  binary scan $blob I* L
  lset L $idx $val
  binary format I* $L
}

do_catchsql_test 1.0 {
  SELECT rtreecheck();
} {1 {wrong number of arguments to function rtreecheck()}}

do_catchsql_test 1.1 {
  SELECT rtreecheck(0,0,0);
} {1 {wrong number of arguments to function rtreecheck()}}


proc setup_simple_db {{module rtree}} {
  reset_db
  db func swap_int32 swap_int32
  execsql "
    CREATE VIRTUAL TABLE r1 USING $module (id, x1, x2, y1, y2);
    INSERT INTO r1 VALUES(1,  5, 5, 5, 5);  --  3
    INSERT INTO r1 VALUES(2,  6, 6, 6, 6);  --  9
    INSERT INTO r1 VALUES(3,  7, 7, 7, 7);  -- 15
    INSERT INTO r1 VALUES(4,  8, 8, 8, 8);  -- 21
    INSERT INTO r1 VALUES(5,  9, 9, 9, 9);  -- 27
  "
}

setup_simple_db
do_execsql_test 2.1 { 
  SELECT rtreecheck('r1') 
} {ok}

do_execsql_test 2.2 {
  UPDATE r1_node SET data = swap_int32(data, 3, 9);
  UPDATE r1_node SET data = swap_int32(data, 23, 29);
}

do_execsql_test 2.3 { 
  SELECT rtreecheck('r1') 
} {{Dimension 0 of cell 0 on node 1 is corrupt
Dimension 1 of cell 3 on node 1 is corrupt}}

setup_simple_db
do_execsql_test 2.4 {
  DELETE FROM r1_rowid WHERE rowid = 3;
  SELECT rtreecheck('r1') 
} {{Mapping (3 -> 1) missing from %_rowid table
Wrong number of entries in %_rowid table - expected 5, actual 4}}

setup_simple_db
do_execsql_test 2.5 {
  UPDATE r1_rowid SET nodeno=2 WHERE rowid=3;
  SELECT rtreecheck('r1') 
} {{Found (3 -> 2) in %_rowid table, expected (3 -> 1)}}

reset_db
do_execsql_test 3.0 { 
  CREATE VIRTUAL TABLE r1 USING rtree_i32(id, x1, x2);
  INSERT INTO r1 VALUES(1, 0x7FFFFFFF*-1, 0x7FFFFFFF);
  INSERT INTO r1 VALUES(2, 0x7FFFFFFF*-1, 5);
  INSERT INTO r1 VALUES(3, -5, 5);
  INSERT INTO r1 VALUES(4, 5, 0x11111111);
  INSERT INTO r1 VALUES(5, 5, 0x00800000);
  INSERT INTO r1 VALUES(6, 5, 0x00008000);
  INSERT INTO r1 VALUES(7, 5, 0x00000080);
  INSERT INTO r1 VALUES(8, 5, 0x40490fdb);
  INSERT INTO r1 VALUES(9, 0x7f800000, 0x7f900000);
  SELECT rtreecheck('r1') 
} {ok}

do_execsql_test 3.1 { 
  CREATE VIRTUAL TABLE r2 USING rtree_i32(id, x1, x2);
  INSERT INTO r2 VALUES(2, -1*(1<<31), -1*(1<<31)+5);
  SELECT rtreecheck('r2') 
} {ok}

do_execsql_test 3.2 {
  BEGIN;
    UPDATE r2_node SET data = X'123456';
    SELECT rtreecheck('r2')!="ok";
} {1}

do_execsql_test 3.3 {
  ROLLBACK;
  UPDATE r2_node SET data = X'00001234';
  SELECT rtreecheck('r2')!="ok";
} {1}

do_execsql_test 4.0 {
  CREATE TABLE notanrtree(i);
  SELECT rtreecheck('notanrtree');
} {{Schema corrupt or not an rtree}}

#-------------------------------------------------------------------------
#
reset_db
db func set_int32 set_int32
do_execsql_test 5.0 {
  CREATE VIRTUAL TABLE r3 USING rtree_i32(id, x1, x2, y1, y2);
  WITH x(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM x WHERE i<1000
  )
  INSERT INTO r3 SELECT i, i, i, i, i FROM x;
}
do_execsql_test 5.1 {
  BEGIN;
    UPDATE r3_node SET data = set_int32(data, 3, 5000);
    UPDATE r3_node SET data = set_int32(data, 4, 5000);
    SELECT rtreecheck('r3')=='ok'
} 0
do_execsql_test 5.2 {
  ROLLBACK;
  BEGIN;
    UPDATE r3_node SET data = set_int32(data, 3, 0);
    UPDATE r3_node SET data = set_int32(data, 4, 0);
    SELECT rtreecheck('r3')=='ok'
} 0

finish_test

# executables needed for testing
#
TESTPROGS = \
  testfixture$(EXE) \
  sqlite3$(EXE) \
  sqlite3_analyzer$(EXE) \

  sqldiff$(EXE) \
  dbhash$(EXE)

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)/test/fuzzdata1.db \
................................................................................
	tclsh $(TOP)/tool/vdbe-compress.tcl $(OPTS) <tsrc/vdbe.c >vdbe.new
	mv vdbe.new tsrc/vdbe.c
	cp fts5.c fts5.h tsrc
	touch target_source

sqlite3.c:	target_source $(TOP)/tool/mksqlite3c.tcl
	tclsh $(TOP)/tool/mksqlite3c.tcl
	cp tsrc/shell.c tsrc/sqlite3ext.h .
	cp $(TOP)/ext/session/sqlite3session.h .
	echo '#ifndef USE_SYSTEM_SQLITE' >tclsqlite3.c
	cat sqlite3.c >>tclsqlite3.c
	echo '#endif /* USE_SYSTEM_SQLITE */' >>tclsqlite3.c
	cat $(TOP)/src/tclsqlite.c >>tclsqlite3.c

sqlite3ext.h:	target_source
................................................................................

sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/sqlite3_analyzer.c.in $(TOP)/tool/mkccode.tcl
	tclsh $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(EXE): sqlite3_analyzer.c
	$(TCCX) $(TCL_FLAGS) sqlite3_analyzer.c -o $@ $(LIBTCL) $(THREADLIB) 

















dbdump$(EXE):	$(TOP)/ext/misc/dbdump.c sqlite3.o
	$(TCCX) -DDBDUMP_STANDALONE -o dbdump$(EXE) \
            $(TOP)/ext/misc/dbdump.c sqlite3.o $(THREADLIB)

# Rules to build the 'testfixture' application.
#
TESTFIXTURE_FLAGS  = -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
................................................................................
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o showjournal$(EXE) \
		$(TOP)/tool/showjournal.c sqlite3.o $(THREADLIB)

showwal$(EXE):	$(TOP)/tool/showwal.c sqlite3.o
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o showwal$(EXE) \
		$(TOP)/tool/showwal.c sqlite3.o $(THREADLIB)




changeset$(EXE):	$(TOP)/ext/session/changeset.c sqlite3.o
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o changeset$(EXE) \
		$(TOP)/ext/session/changeset.c sqlite3.o $(THREADLIB)

fts3view$(EXE):	$(TOP)/ext/fts3/tool/fts3view.c sqlite3.o
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o fts3view$(EXE) \
		$(TOP)/ext/fts3/tool/fts3view.c sqlite3.o $(THREADLIB)

# executables needed for testing
#
TESTPROGS = \
  testfixture$(EXE) \
  sqlite3$(EXE) \
  sqlite3_analyzer$(EXE) \
  sqlite3_checker$(EXE) \
  sqldiff$(EXE) \
  dbhash$(EXE)

# Databases containing fuzzer test cases
#
FUZZDATA = \
  $(TOP)/test/fuzzdata1.db \
................................................................................
	tclsh $(TOP)/tool/vdbe-compress.tcl $(OPTS) <tsrc/vdbe.c >vdbe.new
	mv vdbe.new tsrc/vdbe.c
	cp fts5.c fts5.h tsrc
	touch target_source

sqlite3.c:	target_source $(TOP)/tool/mksqlite3c.tcl
	tclsh $(TOP)/tool/mksqlite3c.tcl
	cp tsrc/sqlite3ext.h .
	cp $(TOP)/ext/session/sqlite3session.h .
	echo '#ifndef USE_SYSTEM_SQLITE' >tclsqlite3.c
	cat sqlite3.c >>tclsqlite3.c
	echo '#endif /* USE_SYSTEM_SQLITE */' >>tclsqlite3.c
	cat $(TOP)/src/tclsqlite.c >>tclsqlite3.c

sqlite3ext.h:	target_source
................................................................................

sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/sqlite3_analyzer.c.in $(TOP)/tool/mkccode.tcl
	tclsh $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

sqlite3_analyzer$(EXE): sqlite3_analyzer.c
	$(TCCX) $(TCL_FLAGS) sqlite3_analyzer.c -o $@ $(LIBTCL) $(THREADLIB) 

CHECKER_DEPS =\
  $(TOP)/tool/mkccode.tcl \
  sqlite3.c \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/ext/repair/sqlite3_checker.tcl \
  $(TOP)/ext/repair/checkindex.c \
  $(TOP)/ext/repair/checkfreelist.c \
  $(TOP)/ext/misc/btreeinfo.c \
  $(TOP)/ext/repair/sqlite3_checker.c.in

sqlite3_checker.c:	$(CHECKER_DEPS)
	tclsh $(TOP)/tool/mkccode.tcl $(TOP)/ext/repair/sqlite3_checker.c.in >$@

sqlite3_checker$(TEXE):	sqlite3_checker.c
	$(TCCX) $(TCL_FLAGS) sqlite3_checker.c -o $@ $(LIBTCL) $(THREADLIB)

dbdump$(EXE):	$(TOP)/ext/misc/dbdump.c sqlite3.o
	$(TCCX) -DDBDUMP_STANDALONE -o dbdump$(EXE) \
            $(TOP)/ext/misc/dbdump.c sqlite3.o $(THREADLIB)

# Rules to build the 'testfixture' application.
#
TESTFIXTURE_FLAGS  = -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
................................................................................
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o showjournal$(EXE) \
		$(TOP)/tool/showjournal.c sqlite3.o $(THREADLIB)

showwal$(EXE):	$(TOP)/tool/showwal.c sqlite3.o
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o showwal$(EXE) \
		$(TOP)/tool/showwal.c sqlite3.o $(THREADLIB)

showshm$(EXE):	$(TOP)/tool/showshm.c
	$(TCC) -o showshm$(EXE) $(TOP)/tool/showshm.c

changeset$(EXE):	$(TOP)/ext/session/changeset.c sqlite3.o
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o changeset$(EXE) \
		$(TOP)/ext/session/changeset.c sqlite3.o $(THREADLIB)

fts3view$(EXE):	$(TOP)/ext/fts3/tool/fts3view.c sqlite3.o
	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o fts3view$(EXE) \
		$(TOP)/ext/fts3/tool/fts3view.c sqlite3.o $(THREADLIB)

    }
    if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pLimit) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pOffset) ){
      return 1;
    }
    pSelect = pSelect->pPrior;
  }
  return 0;
}
int sqlite3FixExpr(
  DbFixer *pFix,     /* Context of the fixation */
  Expr *pExpr        /* The expression to be fixed to one database */

    }
    if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){
      return 1;
    }
    if( sqlite3FixExpr(pFix, pSelect->pLimit) ){
      return 1;
    }



    pSelect = pSelect->pPrior;
  }
  return 0;
}
int sqlite3FixExpr(
  DbFixer *pFix,     /* Context of the fixation */
  Expr *pExpr        /* The expression to be fixed to one database */

  Table *p;
  int i;
  char *z;
  char *zType;
  Column *pCol;
  sqlite3 *db = pParse->db;
  if( (p = pParse->pNewTable)==0 ) return;
#if SQLITE_MAX_COLUMN
  if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
    return;
  }
#endif
  z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
  if( z==0 ) return;
  memcpy(z, pName->z, pName->n);
  z[pName->n] = 0;
  sqlite3Dequote(z);
  for(i=0; i<p->nCol; i++){
    if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){
................................................................................
  if( !p && (pOn || pUsing) ){
    sqlite3ErrorMsg(pParse, "a JOIN clause is required before %s", 
      (pOn ? "ON" : "USING")
    );
    goto append_from_error;
  }
  p = sqlite3SrcListAppend(db, p, pTable, pDatabase);
  if( p==0 || NEVER(p->nSrc==0) ){
    goto append_from_error;
  }

  pItem = &p->a[p->nSrc-1];
  assert( pAlias!=0 );
  if( pAlias->n ){
    pItem->zAlias = sqlite3NameFromToken(db, pAlias);
  }
  pItem->pSelect = pSubquery;
  pItem->pOn = pOn;

  Table *p;
  int i;
  char *z;
  char *zType;
  Column *pCol;
  sqlite3 *db = pParse->db;
  if( (p = pParse->pNewTable)==0 ) return;

  if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
    return;
  }

  z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
  if( z==0 ) return;
  memcpy(z, pName->z, pName->n);
  z[pName->n] = 0;
  sqlite3Dequote(z);
  for(i=0; i<p->nCol; i++){
    if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){
................................................................................
  if( !p && (pOn || pUsing) ){
    sqlite3ErrorMsg(pParse, "a JOIN clause is required before %s", 
      (pOn ? "ON" : "USING")
    );
    goto append_from_error;
  }
  p = sqlite3SrcListAppend(db, p, pTable, pDatabase);
  if( p==0 ){
    goto append_from_error;
  }
  assert( p->nSrc>0 );
  pItem = &p->a[p->nSrc-1];
  assert( pAlias!=0 );
  if( pAlias->n ){
    pItem->zAlias = sqlite3NameFromToken(db, pAlias);
  }
  pItem->pSelect = pSubquery;
  pItem->pOn = pOn;

typedef struct DbpageTable DbpageTable;
typedef struct DbpageCursor DbpageCursor;

struct DbpageCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  int pgno;                       /* Current page number */
  int mxPgno;                     /* Last page to visit on this scan */




};

struct DbpageTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The database */
  Pager *pPager;                  /* Pager being read/written */
  int iDb;                        /* Index of database to analyze */
  int szPage;                     /* Size of each page in bytes */
  int nPage;                      /* Number of pages in the file */
};








/*
** Connect to or create a dbpagevfs virtual table.
*/
static int dbpageConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  DbpageTable *pTab = 0;
  int rc = SQLITE_OK;
  int iDb;

  if( argc>=4 ){
    Token nm;
    sqlite3TokenInit(&nm, (char*)argv[3]);
    iDb = sqlite3FindDb(db, &nm);
    if( iDb<0 ){
      *pzErr = sqlite3_mprintf("no such schema: %s", argv[3]);
      return SQLITE_ERROR;
    }
  }else{
    iDb = 0;
  }
  rc = sqlite3_declare_vtab(db, 
          "CREATE TABLE x(pgno INTEGER PRIMARY KEY, data BLOB, schema HIDDEN)");
  if( rc==SQLITE_OK ){
    pTab = (DbpageTable *)sqlite3_malloc64(sizeof(DbpageTable));
    if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;
  }

  assert( rc==SQLITE_OK || pTab==0 );
  if( rc==SQLITE_OK ){
    Btree *pBt = db->aDb[iDb].pBt;
    memset(pTab, 0, sizeof(DbpageTable));
    pTab->db = db;
    pTab->iDb = iDb;
    pTab->pPager = pBt ? sqlite3BtreePager(pBt) : 0;
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
................................................................................
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** idxNum:
**
**     0     full table scan
**     1     pgno=?1


*/
static int dbpageBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int i;

























  pIdxInfo->estimatedCost = 1.0e6;  /* Initial cost estimate */


  for(i=0; i<pIdxInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
    if( p->usable && p->iColumn<=0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      pIdxInfo->estimatedRows = 1;
      pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;
      pIdxInfo->estimatedCost = 1.0;
      pIdxInfo->idxNum = 1;
      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
      pIdxInfo->aConstraintUsage[i].omit = 1;

      break;
    }
  }


  if( pIdxInfo->nOrderBy>=1
   && pIdxInfo->aOrderBy[0].iColumn<=0
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }
  return SQLITE_OK;
................................................................................
}

/*
** Close a dbpagevfs cursor.
*/
static int dbpageClose(sqlite3_vtab_cursor *pCursor){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Move a dbpagevfs cursor to the next entry in the file.
*/
................................................................................
}

static int dbpageEof(sqlite3_vtab_cursor *pCursor){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  return pCsr->pgno > pCsr->mxPgno;
}











static int dbpageFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  DbpageTable *pTab = (DbpageTable *)pCursor->pVtab;
  int rc = SQLITE_OK;

  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;

















  pTab->szPage = sqlite3BtreeGetPageSize(pBt);
  pTab->nPage = sqlite3BtreeLastPage(pBt);
  if( idxNum==1 ){

    pCsr->pgno = sqlite3_value_int(argv[0]);
    if( pCsr->pgno<1 || pCsr->pgno>pTab->nPage ){
      pCsr->pgno = 1;
      pCsr->mxPgno = 0;
    }else{
      pCsr->mxPgno = pCsr->pgno;
    }
  }else{
    pCsr->pgno = 1;
    pCsr->mxPgno = pTab->nPage;
  }


  return rc;
}

static int dbpageColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  DbpageTable *pTab = (DbpageTable *)pCursor->pVtab;
  int rc = SQLITE_OK;
  switch( i ){
    case 0: {           /* pgno */
      sqlite3_result_int(ctx, pCsr->pgno);
      break;
    }
    case 1: {           /* data */
      DbPage *pDbPage = 0;
      rc = sqlite3PagerGet(pTab->pPager, pCsr->pgno, (DbPage**)&pDbPage, 0);
      if( rc==SQLITE_OK ){
        sqlite3_result_blob(ctx, sqlite3PagerGetData(pDbPage), pTab->szPage,
                            SQLITE_TRANSIENT);
      }
      sqlite3PagerUnref(pDbPage);
      break;
    }
    default: {          /* schema */
      sqlite3 *db = sqlite3_context_db_handle(ctx);
      sqlite3_result_text(ctx, db->aDb[pTab->iDb].zDbSName, -1, SQLITE_STATIC);
      break;
    }
  }
  return SQLITE_OK;
}

static int dbpageRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
................................................................................
static int dbpageUpdate(
  sqlite3_vtab *pVtab,
  int argc,
  sqlite3_value **argv,
  sqlite_int64 *pRowid
){
  DbpageTable *pTab = (DbpageTable *)pVtab;
  int pgno;
  DbPage *pDbPage = 0;
  int rc = SQLITE_OK;
  char *zErr = 0;






  if( argc==1 ){
    zErr = "cannot delete";
    goto update_fail;
  }
  pgno = sqlite3_value_int(argv[0]);
  if( pgno<1 || pgno>pTab->nPage ){
    zErr = "bad page number";
    goto update_fail;
  }
  if( sqlite3_value_int(argv[1])!=pgno ){
    zErr = "cannot insert";
    goto update_fail;
  }












  if( sqlite3_value_type(argv[3])!=SQLITE_BLOB 
   || sqlite3_value_bytes(argv[3])!=pTab->szPage 
  ){
    zErr = "bad page value";
    goto update_fail;
  }

  rc = sqlite3PagerGet(pTab->pPager, pgno, (DbPage**)&pDbPage, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3PagerWrite(pDbPage);
    if( rc==SQLITE_OK ){
      memcpy(sqlite3PagerGetData(pDbPage),
             sqlite3_value_blob(argv[3]),
             pTab->szPage);
    }
  }
  sqlite3PagerUnref(pDbPage);
  return rc;

update_fail:
  sqlite3_free(pVtab->zErrMsg);
  pVtab->zErrMsg = sqlite3_mprintf("%s", zErr);
  return SQLITE_ERROR;
}

















/*
** Invoke this routine to register the "dbpage" virtual table module
*/
int sqlite3DbpageRegister(sqlite3 *db){
  static sqlite3_module dbpage_module = {
    0,                            /* iVersion */
................................................................................
    dbpageClose,                  /* xClose - close a cursor */
    dbpageFilter,                 /* xFilter - configure scan constraints */
    dbpageNext,                   /* xNext - advance a cursor */
    dbpageEof,                    /* xEof - check for end of scan */
    dbpageColumn,                 /* xColumn - read data */
    dbpageRowid,                  /* xRowid - read data */
    dbpageUpdate,                 /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */

typedef struct DbpageTable DbpageTable;
typedef struct DbpageCursor DbpageCursor;

struct DbpageCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  int pgno;                       /* Current page number */
  int mxPgno;                     /* Last page to visit on this scan */
  Pager *pPager;                  /* Pager being read/written */
  DbPage *pPage1;                 /* Page 1 of the database */
  int iDb;                        /* Index of database to analyze */
  int szPage;                     /* Size of each page in bytes */
};

struct DbpageTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The database */




};

/* Columns */
#define DBPAGE_COLUMN_PGNO    0
#define DBPAGE_COLUMN_DATA    1
#define DBPAGE_COLUMN_SCHEMA  2



/*
** Connect to or create a dbpagevfs virtual table.
*/
static int dbpageConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  DbpageTable *pTab = 0;
  int rc = SQLITE_OK;













  rc = sqlite3_declare_vtab(db, 
          "CREATE TABLE x(pgno INTEGER PRIMARY KEY, data BLOB, schema HIDDEN)");
  if( rc==SQLITE_OK ){
    pTab = (DbpageTable *)sqlite3_malloc64(sizeof(DbpageTable));
    if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;
  }

  assert( rc==SQLITE_OK || pTab==0 );
  if( rc==SQLITE_OK ){

    memset(pTab, 0, sizeof(DbpageTable));
    pTab->db = db;


  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
................................................................................
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/*
** idxNum:
**
**     0     schema=main, full table scan
**     1     schema=main, pgno=?1
**     2     schema=?1, full table scan
**     3     schema=?1, pgno=?2
*/
static int dbpageBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int i;
  int iPlan = 0;

  /* If there is a schema= constraint, it must be honored.  Report a
  ** ridiculously large estimated cost if the schema= constraint is
  ** unavailable
  */
  for(i=0; i<pIdxInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
    if( p->iColumn!=DBPAGE_COLUMN_SCHEMA ) continue;
    if( p->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    if( !p->usable ){
      /* No solution.  Use the default SQLITE_BIG_DBL cost */
      pIdxInfo->estimatedRows = 0x7fffffff;
      return SQLITE_OK;
    }
    iPlan = 2;
    pIdxInfo->aConstraintUsage[i].argvIndex = 1;
    pIdxInfo->aConstraintUsage[i].omit = 1;
    break;
  }

  /* If we reach this point, it means that either there is no schema=
  ** constraint (in which case we use the "main" schema) or else the
  ** schema constraint was accepted.  Lower the estimated cost accordingly
  */
  pIdxInfo->estimatedCost = 1.0e6;

  /* Check for constraints against pgno */
  for(i=0; i<pIdxInfo->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
    if( p->usable && p->iColumn<=0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      pIdxInfo->estimatedRows = 1;
      pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;
      pIdxInfo->estimatedCost = 1.0;

      pIdxInfo->aConstraintUsage[i].argvIndex = iPlan ? 2 : 1;
      pIdxInfo->aConstraintUsage[i].omit = 1;
      iPlan |= 1;
      break;
    }
  }
  pIdxInfo->idxNum = iPlan;

  if( pIdxInfo->nOrderBy>=1
   && pIdxInfo->aOrderBy[0].iColumn<=0
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }
  return SQLITE_OK;
................................................................................
}

/*
** Close a dbpagevfs cursor.
*/
static int dbpageClose(sqlite3_vtab_cursor *pCursor){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  if( pCsr->pPage1 ) sqlite3PagerUnrefPageOne(pCsr->pPage1);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/*
** Move a dbpagevfs cursor to the next entry in the file.
*/
................................................................................
}

static int dbpageEof(sqlite3_vtab_cursor *pCursor){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  return pCsr->pgno > pCsr->mxPgno;
}

/*
** idxNum:
**
**     0     schema=main, full table scan
**     1     schema=main, pgno=?1
**     2     schema=?1, full table scan
**     3     schema=?1, pgno=?2
**
** idxStr is not used
*/
static int dbpageFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  DbpageTable *pTab = (DbpageTable *)pCursor->pVtab;
  int rc;
  sqlite3 *db = pTab->db;
  Btree *pBt;

  /* Default setting is no rows of result */
  pCsr->pgno = 1; 
  pCsr->mxPgno = 0;

  if( idxNum & 2 ){
    const char *zSchema;
    assert( argc>=1 );
    zSchema = (const char*)sqlite3_value_text(argv[0]);
    pCsr->iDb = sqlite3FindDbName(db, zSchema);
    if( pCsr->iDb<0 ) return SQLITE_OK;
  }else{
    pCsr->iDb = 0;
  }
  pBt = db->aDb[pCsr->iDb].pBt;
  if( pBt==0 ) return SQLITE_OK;
  pCsr->pPager = sqlite3BtreePager(pBt);
  pCsr->szPage = sqlite3BtreeGetPageSize(pBt);
  pCsr->mxPgno = sqlite3BtreeLastPage(pBt);
  if( idxNum & 1 ){
    assert( argc>(idxNum>>1) );
    pCsr->pgno = sqlite3_value_int(argv[idxNum>>1]);
    if( pCsr->pgno<1 || pCsr->pgno>pCsr->mxPgno ){
      pCsr->pgno = 1;
      pCsr->mxPgno = 0;
    }else{
      pCsr->mxPgno = pCsr->pgno;
    }
  }else{
    assert( pCsr->pgno==1 );

  }
  if( pCsr->pPage1 ) sqlite3PagerUnrefPageOne(pCsr->pPage1);
  rc = sqlite3PagerGet(pCsr->pPager, 1, &pCsr->pPage1, 0);
  return rc;
}

static int dbpageColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;

  int rc = SQLITE_OK;
  switch( i ){
    case 0: {           /* pgno */
      sqlite3_result_int(ctx, pCsr->pgno);
      break;
    }
    case 1: {           /* data */
      DbPage *pDbPage = 0;
      rc = sqlite3PagerGet(pCsr->pPager, pCsr->pgno, (DbPage**)&pDbPage, 0);
      if( rc==SQLITE_OK ){
        sqlite3_result_blob(ctx, sqlite3PagerGetData(pDbPage), pCsr->szPage,
                            SQLITE_TRANSIENT);
      }
      sqlite3PagerUnref(pDbPage);
      break;
    }
    default: {          /* schema */
      sqlite3 *db = sqlite3_context_db_handle(ctx);
      sqlite3_result_text(ctx, db->aDb[pCsr->iDb].zDbSName, -1, SQLITE_STATIC);
      break;
    }
  }
  return SQLITE_OK;
}

static int dbpageRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
................................................................................
static int dbpageUpdate(
  sqlite3_vtab *pVtab,
  int argc,
  sqlite3_value **argv,
  sqlite_int64 *pRowid
){
  DbpageTable *pTab = (DbpageTable *)pVtab;
  Pgno pgno;
  DbPage *pDbPage = 0;
  int rc = SQLITE_OK;
  char *zErr = 0;
  const char *zSchema;
  int iDb;
  Btree *pBt;
  Pager *pPager;
  int szPage;

  if( argc==1 ){
    zErr = "cannot delete";
    goto update_fail;
  }
  pgno = sqlite3_value_int(argv[0]);




  if( (Pgno)sqlite3_value_int(argv[1])!=pgno ){
    zErr = "cannot insert";
    goto update_fail;
  }
  zSchema = (const char*)sqlite3_value_text(argv[4]);
  iDb = zSchema ? sqlite3FindDbName(pTab->db, zSchema) : -1;
  if( iDb<0 ){
    zErr = "no such schema";
    goto update_fail;
  }
  pBt = pTab->db->aDb[iDb].pBt;
  if( pgno<1 || pBt==0 || pgno>(int)sqlite3BtreeLastPage(pBt) ){
    zErr = "bad page number";
    goto update_fail;
  }
  szPage = sqlite3BtreeGetPageSize(pBt);
  if( sqlite3_value_type(argv[3])!=SQLITE_BLOB 
   || sqlite3_value_bytes(argv[3])!=szPage
  ){
    zErr = "bad page value";
    goto update_fail;
  }
  pPager = sqlite3BtreePager(pBt);
  rc = sqlite3PagerGet(pPager, pgno, (DbPage**)&pDbPage, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3PagerWrite(pDbPage);
    if( rc==SQLITE_OK ){
      memcpy(sqlite3PagerGetData(pDbPage),
             sqlite3_value_blob(argv[3]),
             szPage);
    }
  }
  sqlite3PagerUnref(pDbPage);
  return rc;

update_fail:
  sqlite3_free(pVtab->zErrMsg);
  pVtab->zErrMsg = sqlite3_mprintf("%s", zErr);
  return SQLITE_ERROR;
}

/* Since we do not know in advance which database files will be
** written by the sqlite_dbpage virtual table, start a write transaction
** on them all.
*/
static int dbpageBegin(sqlite3_vtab *pVtab){
  DbpageTable *pTab = (DbpageTable *)pVtab;
  sqlite3 *db = pTab->db;
  int i;
  for(i=0; i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ) sqlite3BtreeBeginTrans(pBt, 1);
  }
  return SQLITE_OK;
}


/*
** Invoke this routine to register the "dbpage" virtual table module
*/
int sqlite3DbpageRegister(sqlite3 *db){
  static sqlite3_module dbpage_module = {
    0,                            /* iVersion */
................................................................................
    dbpageClose,                  /* xClose - close a cursor */
    dbpageFilter,                 /* xFilter - configure scan constraints */
    dbpageNext,                   /* xNext - advance a cursor */
    dbpageEof,                    /* xEof - check for end of scan */
    dbpageColumn,                 /* xColumn - read data */
    dbpageRowid,                  /* xRowid - read data */
    dbpageUpdate,                 /* xUpdate */
    dbpageBegin,                  /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */

** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
  Parse *pParse,       /* Parsing context */
  Table *pView,        /* View definition */
  Expr *pWhere,        /* Optional WHERE clause to be added */


  int iCur             /* Cursor number for ephemeral table */
){
  SelectDest dest;
  Select *pSel;
  SrcList *pFrom;
  sqlite3 *db = pParse->db;
  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
................................................................................
  if( pFrom ){
    assert( pFrom->nSrc==1 );
    pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
    assert( pFrom->a[0].pOn==0 );
    assert( pFrom->a[0].pUsing==0 );
  }
  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 
                          SF_IncludeHidden, 0, 0);
  sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
  sqlite3Select(pParse, pSel, &dest);
  sqlite3SelectDelete(db, pSel);
}
#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */

#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
................................................................................
*/
Expr *sqlite3LimitWhere(
  Parse *pParse,               /* The parser context */
  SrcList *pSrc,               /* the FROM clause -- which tables to scan */
  Expr *pWhere,                /* The WHERE clause.  May be null */
  ExprList *pOrderBy,          /* The ORDER BY clause.  May be null */
  Expr *pLimit,                /* The LIMIT clause.  May be null */
  Expr *pOffset,               /* The OFFSET clause.  May be null */
  char *zStmtType              /* Either DELETE or UPDATE.  For err msgs. */
){

  Expr *pWhereRowid = NULL;    /* WHERE rowid .. */
  Expr *pInClause = NULL;      /* WHERE rowid IN ( select ) */
  Expr *pSelectRowid = NULL;   /* SELECT rowid ... */
  ExprList *pEList = NULL;     /* Expression list contaning only pSelectRowid */
  SrcList *pSelectSrc = NULL;  /* SELECT rowid FROM x ... (dup of pSrc) */
  Select *pSelect = NULL;      /* Complete SELECT tree */


  /* Check that there isn't an ORDER BY without a LIMIT clause.
  */
  if( pOrderBy && (pLimit == 0) ) {
    sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
    goto limit_where_cleanup;


  }

  /* We only need to generate a select expression if there
  ** is a limit/offset term to enforce.
  */
  if( pLimit == 0 ) {
    /* if pLimit is null, pOffset will always be null as well. */
    assert( pOffset == 0 );
    return pWhere;
  }

  /* Generate a select expression tree to enforce the limit/offset 
  ** term for the DELETE or UPDATE statement.  For example:
  **   DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
  ** becomes:
  **   DELETE FROM table_a WHERE rowid IN ( 
  **     SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
  **   );
  */



  pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0);
  if( pSelectRowid == 0 ) goto limit_where_cleanup;













  pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid);
  if( pEList == 0 ) goto limit_where_cleanup;








  /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
  ** and the SELECT subtree. */

  pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
  if( pSelectSrc == 0 ) {
    sqlite3ExprListDelete(pParse->db, pEList);
    goto limit_where_cleanup;


  }

  /* generate the SELECT expression tree. */
  pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0,
                             pOrderBy,0,pLimit,pOffset);
  if( pSelect == 0 ) return 0;


  /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
  pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0);
  pInClause = pWhereRowid ? sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0) : 0;
  sqlite3PExprAddSelect(pParse, pInClause, pSelect);
  return pInClause;

limit_where_cleanup:
  sqlite3ExprDelete(pParse->db, pWhere);
  sqlite3ExprListDelete(pParse->db, pOrderBy);
  sqlite3ExprDelete(pParse->db, pLimit);
  sqlite3ExprDelete(pParse->db, pOffset);
  return 0;
}
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
       /*      && !defined(SQLITE_OMIT_SUBQUERY) */

/*
** Generate code for a DELETE FROM statement.
**
................................................................................
**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
**                 \________/       \________________/
**                  pTabList              pWhere
*/
void sqlite3DeleteFrom(
  Parse *pParse,         /* The parser context */
  SrcList *pTabList,     /* The table from which we should delete things */
  Expr *pWhere           /* The WHERE clause.  May be null */


){
  Vdbe *v;               /* The virtual database engine */
  Table *pTab;           /* The table from which records will be deleted */
  int i;                 /* Loop counter */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Index *pIdx;           /* For looping over indices of the table */
  int iTabCur;           /* Cursor number for the table */
................................................................................

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
    goto delete_from_cleanup;
  }
  assert( pTabList->nSrc==1 );


  /* Locate the table which we want to delete.  This table has to be
  ** put in an SrcList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect
  ** an SrcList* parameter instead of just a Table* parameter.
  */
  pTab = sqlite3SrcListLookup(pParse, pTabList);
................................................................................
# define pTrigger 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif











  /* If pTab is really a view, make sure it has been initialized.
  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto delete_from_cleanup;
  }

................................................................................
  sqlite3BeginWriteOperation(pParse, 1, iDb);

  /* If we are trying to delete from a view, realize that view into
  ** an ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, pWhere, iTabCur);


    iDataCur = iIdxCur = iTabCur;


  }
#endif

  /* Resolve the column names in the WHERE clause.
  */
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pParse;
................................................................................
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
  }

delete_from_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprDelete(db, pWhere);




  sqlite3DbFree(db, aToOpen);
  return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation).  */
#ifdef isView

** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
  Parse *pParse,       /* Parsing context */
  Table *pView,        /* View definition */
  Expr *pWhere,        /* Optional WHERE clause to be added */
  ExprList *pOrderBy,  /* Optional ORDER BY clause */
  Expr *pLimit,        /* Optional LIMIT clause */
  int iCur             /* Cursor number for ephemeral table */
){
  SelectDest dest;
  Select *pSel;
  SrcList *pFrom;
  sqlite3 *db = pParse->db;
  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
................................................................................
  if( pFrom ){
    assert( pFrom->nSrc==1 );
    pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
    assert( pFrom->a[0].pOn==0 );
    assert( pFrom->a[0].pUsing==0 );
  }
  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, pOrderBy, 
                          SF_IncludeHidden, pLimit);
  sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
  sqlite3Select(pParse, pSel, &dest);
  sqlite3SelectDelete(db, pSel);
}
#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */

#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
................................................................................
*/
Expr *sqlite3LimitWhere(
  Parse *pParse,               /* The parser context */
  SrcList *pSrc,               /* the FROM clause -- which tables to scan */
  Expr *pWhere,                /* The WHERE clause.  May be null */
  ExprList *pOrderBy,          /* The ORDER BY clause.  May be null */
  Expr *pLimit,                /* The LIMIT clause.  May be null */

  char *zStmtType              /* Either DELETE or UPDATE.  For err msgs. */
){
  sqlite3 *db = pParse->db;
  Expr *pLhs = NULL;           /* LHS of IN(SELECT...) operator */
  Expr *pInClause = NULL;      /* WHERE rowid IN ( select ) */

  ExprList *pEList = NULL;     /* Expression list contaning only pSelectRowid */
  SrcList *pSelectSrc = NULL;  /* SELECT rowid FROM x ... (dup of pSrc) */
  Select *pSelect = NULL;      /* Complete SELECT tree */
  Table *pTab;

  /* Check that there isn't an ORDER BY without a LIMIT clause.
  */
  if( pOrderBy && pLimit==0 ) {
    sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
    sqlite3ExprDelete(pParse->db, pWhere);
    sqlite3ExprListDelete(pParse->db, pOrderBy);
    return 0;
  }

  /* We only need to generate a select expression if there
  ** is a limit/offset term to enforce.
  */
  if( pLimit == 0 ) {


    return pWhere;
  }

  /* Generate a select expression tree to enforce the limit/offset 
  ** term for the DELETE or UPDATE statement.  For example:
  **   DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
  ** becomes:
  **   DELETE FROM table_a WHERE rowid IN ( 
  **     SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
  **   );
  */

  pTab = pSrc->a[0].pTab;
  if( HasRowid(pTab) ){
    pLhs = sqlite3PExpr(pParse, TK_ROW, 0, 0);

    pEList = sqlite3ExprListAppend(
        pParse, 0, sqlite3PExpr(pParse, TK_ROW, 0, 0)
    );
  }else{
    Index *pPk = sqlite3PrimaryKeyIndex(pTab);
    if( pPk->nKeyCol==1 ){
      const char *zName = pTab->aCol[pPk->aiColumn[0]].zName;
      pLhs = sqlite3Expr(db, TK_ID, zName);
      pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, zName));
    }else{
      int i;
      for(i=0; i<pPk->nKeyCol; i++){
        Expr *p = sqlite3Expr(db, TK_ID, pTab->aCol[pPk->aiColumn[i]].zName);
        pEList = sqlite3ExprListAppend(pParse, pEList, p);

      }
      pLhs = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);
      if( pLhs ){
        pLhs->x.pList = sqlite3ExprListDup(db, pEList, 0);
      }
    }
  }

  /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
  ** and the SELECT subtree. */
  pSrc->a[0].pTab = 0;
  pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);



  pSrc->a[0].pTab = pTab;
  pSrc->a[0].pIBIndex = 0;


  /* generate the SELECT expression tree. */
  pSelect = sqlite3SelectNew(pParse, pEList, pSelectSrc, pWhere, 0 ,0, 
      pOrderBy,0,pLimit

  );

  /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
  pInClause = sqlite3PExpr(pParse, TK_IN, pLhs, 0);

  sqlite3PExprAddSelect(pParse, pInClause, pSelect);
  return pInClause;







}
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
       /*      && !defined(SQLITE_OMIT_SUBQUERY) */

/*
** Generate code for a DELETE FROM statement.
**
................................................................................
**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
**                 \________/       \________________/
**                  pTabList              pWhere
*/
void sqlite3DeleteFrom(
  Parse *pParse,         /* The parser context */
  SrcList *pTabList,     /* The table from which we should delete things */
  Expr *pWhere,          /* The WHERE clause.  May be null */
  ExprList *pOrderBy,    /* ORDER BY clause. May be null */
  Expr *pLimit           /* LIMIT clause. May be null */
){
  Vdbe *v;               /* The virtual database engine */
  Table *pTab;           /* The table from which records will be deleted */
  int i;                 /* Loop counter */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Index *pIdx;           /* For looping over indices of the table */
  int iTabCur;           /* Cursor number for the table */
................................................................................

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
    goto delete_from_cleanup;
  }
  assert( pTabList->nSrc==1 );


  /* Locate the table which we want to delete.  This table has to be
  ** put in an SrcList structure because some of the subroutines we
  ** will be calling are designed to work with multiple tables and expect
  ** an SrcList* parameter instead of just a Table* parameter.
  */
  pTab = sqlite3SrcListLookup(pParse, pTabList);
................................................................................
# define pTrigger 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  if( !isView ){
    pWhere = sqlite3LimitWhere(
        pParse, pTabList, pWhere, pOrderBy, pLimit, "DELETE"
    );
    pOrderBy = 0;
    pLimit = 0;
  }
#endif

  /* If pTab is really a view, make sure it has been initialized.
  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto delete_from_cleanup;
  }

................................................................................
  sqlite3BeginWriteOperation(pParse, 1, iDb);

  /* If we are trying to delete from a view, realize that view into
  ** an ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, 
        pWhere, pOrderBy, pLimit, iTabCur
    );
    iDataCur = iIdxCur = iTabCur;
    pOrderBy = 0;
    pLimit = 0;
  }
#endif

  /* Resolve the column names in the WHERE clause.
  */
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pParse;
................................................................................
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
  }

delete_from_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) 
  sqlite3ExprListDelete(db, pOrderBy);
  sqlite3ExprDelete(db, pLimit);
#endif
  sqlite3DbFree(db, aToOpen);
  return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation).  */
#ifdef isView

  }
}
static void heightOfSelect(Select *p, int *pnHeight){
  if( p ){
    heightOfExpr(p->pWhere, pnHeight);
    heightOfExpr(p->pHaving, pnHeight);
    heightOfExpr(p->pLimit, pnHeight);
    heightOfExpr(p->pOffset, pnHeight);
    heightOfExprList(p->pEList, pnHeight);
    heightOfExprList(p->pGroupBy, pnHeight);
    heightOfExprList(p->pOrderBy, pnHeight);
    heightOfSelect(p->pPrior, pnHeight);
  }
}

................................................................................
  assert( pToken );
  pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
  if( pNew==0 ){
    sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
    return 0;
  }
  pNew->x.pList = pList;

  assert( !ExprHasProperty(pNew, EP_xIsSelect) );
  sqlite3ExprSetHeightAndFlags(pParse, pNew);
  return pNew;
}

/*
** Assign a variable number to an expression that encodes a wildcard
................................................................................
    pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
    pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
    pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
    pNew->op = p->op;
    pNew->pNext = pNext;
    pNew->pPrior = 0;
    pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);
    pNew->pOffset = sqlite3ExprDup(db, p->pOffset, flags);
    pNew->iLimit = 0;
    pNew->iOffset = 0;
    pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
    pNew->addrOpenEphm[0] = -1;
    pNew->addrOpenEphm[1] = -1;
    pNew->nSelectRow = p->nSelectRow;
    pNew->pWith = withDup(db, p->pWith);
................................................................................
  if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
    testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
    testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
    return 0; /* No DISTINCT keyword and no aggregate functions */
  }
  assert( p->pGroupBy==0 );              /* Has no GROUP BY clause */
  if( p->pLimit ) return 0;              /* Has no LIMIT clause */
  assert( p->pOffset==0 );               /* No LIMIT means no OFFSET */
  if( p->pWhere ) return 0;              /* Has no WHERE clause */
  pSrc = p->pSrc;
  assert( pSrc!=0 );
  if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
  if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */
  pTab = pSrc->a[0].pTab;
  assert( pTab!=0 );
................................................................................
          assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
          pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
        }

        /* Loop through each expression in <exprlist>. */
        r1 = sqlite3GetTempReg(pParse);
        r2 = sqlite3GetTempReg(pParse);
        if( isRowid ) sqlite3VdbeAddOp2(v, OP_Null, 0, r2);
        for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
          Expr *pE2 = pItem->pExpr;
          int iValToIns;

          /* If the expression is not constant then we will need to
          ** disable the test that was generated above that makes sure
          ** this code only executes once.  Because for a non-constant
................................................................................
      **
      ** In both cases, the query is augmented with "LIMIT 1".  Any 
      ** preexisting limit is discarded in place of the new LIMIT 1.
      */
      Select *pSel;                         /* SELECT statement to encode */
      SelectDest dest;                      /* How to deal with SELECT result */
      int nReg;                             /* Registers to allocate */


      testcase( pExpr->op==TK_EXISTS );
      testcase( pExpr->op==TK_SELECT );
      assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
      assert( ExprHasProperty(pExpr, EP_xIsSelect) );

      pSel = pExpr->x.pSelect;
................................................................................
        sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
        VdbeComment((v, "Init EXISTS result"));
      }


      sqlite3ExprDelete(pParse->db, pSel->pLimit);


      pSel->pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,
                                  &sqlite3IntTokens[1], 0);

      pSel->iLimit = 0;
      pSel->selFlags &= ~SF_MultiValue;
      if( sqlite3Select(pParse, pSel, &dest) ){
        return 0;
      }
      rReg = dest.iSDParm;
      ExprSetVVAProperty(pExpr, EP_NoReduce);

  }
}
static void heightOfSelect(Select *p, int *pnHeight){
  if( p ){
    heightOfExpr(p->pWhere, pnHeight);
    heightOfExpr(p->pHaving, pnHeight);
    heightOfExpr(p->pLimit, pnHeight);

    heightOfExprList(p->pEList, pnHeight);
    heightOfExprList(p->pGroupBy, pnHeight);
    heightOfExprList(p->pOrderBy, pnHeight);
    heightOfSelect(p->pPrior, pnHeight);
  }
}

................................................................................
  assert( pToken );
  pNew = sqlite3ExprAlloc(db, TK_FUNCTION, pToken, 1);
  if( pNew==0 ){
    sqlite3ExprListDelete(db, pList); /* Avoid memory leak when malloc fails */
    return 0;
  }
  pNew->x.pList = pList;
  ExprSetProperty(pNew, EP_HasFunc);
  assert( !ExprHasProperty(pNew, EP_xIsSelect) );
  sqlite3ExprSetHeightAndFlags(pParse, pNew);
  return pNew;
}

/*
** Assign a variable number to an expression that encodes a wildcard
................................................................................
    pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy, flags);
    pNew->pHaving = sqlite3ExprDup(db, p->pHaving, flags);
    pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, flags);
    pNew->op = p->op;
    pNew->pNext = pNext;
    pNew->pPrior = 0;
    pNew->pLimit = sqlite3ExprDup(db, p->pLimit, flags);

    pNew->iLimit = 0;
    pNew->iOffset = 0;
    pNew->selFlags = p->selFlags & ~SF_UsesEphemeral;
    pNew->addrOpenEphm[0] = -1;
    pNew->addrOpenEphm[1] = -1;
    pNew->nSelectRow = p->nSelectRow;
    pNew->pWith = withDup(db, p->pWith);
................................................................................
  if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
    testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
    testcase( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
    return 0; /* No DISTINCT keyword and no aggregate functions */
  }
  assert( p->pGroupBy==0 );              /* Has no GROUP BY clause */
  if( p->pLimit ) return 0;              /* Has no LIMIT clause */

  if( p->pWhere ) return 0;              /* Has no WHERE clause */
  pSrc = p->pSrc;
  assert( pSrc!=0 );
  if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
  if( pSrc->a[0].pSelect ) return 0;     /* FROM is not a subquery or view */
  pTab = pSrc->a[0].pTab;
  assert( pTab!=0 );
................................................................................
          assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
          pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
        }

        /* Loop through each expression in <exprlist>. */
        r1 = sqlite3GetTempReg(pParse);
        r2 = sqlite3GetTempReg(pParse);
        if( isRowid ) sqlite3VdbeAddOp4(v, OP_Blob, 0, r2, 0, "", P4_STATIC);
        for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
          Expr *pE2 = pItem->pExpr;
          int iValToIns;

          /* If the expression is not constant then we will need to
          ** disable the test that was generated above that makes sure
          ** this code only executes once.  Because for a non-constant
................................................................................
      **
      ** In both cases, the query is augmented with "LIMIT 1".  Any 
      ** preexisting limit is discarded in place of the new LIMIT 1.
      */
      Select *pSel;                         /* SELECT statement to encode */
      SelectDest dest;                      /* How to deal with SELECT result */
      int nReg;                             /* Registers to allocate */
      Expr *pLimit;                         /* New limit expression */

      testcase( pExpr->op==TK_EXISTS );
      testcase( pExpr->op==TK_SELECT );
      assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
      assert( ExprHasProperty(pExpr, EP_xIsSelect) );

      pSel = pExpr->x.pSelect;
................................................................................
        sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
        VdbeComment((v, "Init EXISTS result"));
      }
      pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[1], 0);
      if( pSel->pLimit ){
        sqlite3ExprDelete(pParse->db, pSel->pLimit->pLeft);
        pSel->pLimit->pLeft = pLimit;
      }else{
        pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);

      }
      pSel->iLimit = 0;
      pSel->selFlags &= ~SF_MultiValue;
      if( sqlite3Select(pParse, pSel, &dest) ){
        return 0;
      }
      rReg = dest.iSDParm;
      ExprSetVVAProperty(pExpr, EP_NoReduce);

      }
      if( !p ) return;
      iSkip = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);
    }

    pParse->disableTriggers = 1;
    sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), 0);
    pParse->disableTriggers = 0;

    /* If the DELETE has generated immediate foreign key constraint 
    ** violations, halt the VDBE and return an error at this point, before
    ** any modifications to the schema are made. This is because statement
    ** transactions are not able to rollback schema changes.  
    **
................................................................................
      if( pRaise ){
        pRaise->affinity = OE_Abort;
      }
      pSelect = sqlite3SelectNew(pParse, 
          sqlite3ExprListAppend(pParse, 0, pRaise),
          sqlite3SrcListAppend(db, 0, &tFrom, 0),
          pWhere,
          0, 0, 0, 0, 0, 0
      );
      pWhere = 0;
    }

    /* Disable lookaside memory allocation */
    db->lookaside.bDisable++;

      }
      if( !p ) return;
      iSkip = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);
    }

    pParse->disableTriggers = 1;
    sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), 0, 0, 0);
    pParse->disableTriggers = 0;

    /* If the DELETE has generated immediate foreign key constraint 
    ** violations, halt the VDBE and return an error at this point, before
    ** any modifications to the schema are made. This is because statement
    ** transactions are not able to rollback schema changes.  
    **
................................................................................
      if( pRaise ){
        pRaise->affinity = OE_Abort;
      }
      pSelect = sqlite3SelectNew(pParse, 
          sqlite3ExprListAppend(pParse, 0, pRaise),
          sqlite3SrcListAppend(db, 0, &tFrom, 0),
          pWhere,
          0, 0, 0, 0, 0
      );
      pWhere = 0;
    }

    /* Disable lookaside memory allocation */
    db->lookaside.bDisable++;

      ** that point.
      **
      ** For a case-insensitive search, set variable cx to be the same as
      ** c but in the other case and search the input string for either
      ** c or cx.
      */
      if( c<=0x80 ){
        u32 cx;
        int bMatch;
        if( noCase ){
          cx = sqlite3Toupper(c);
          c = sqlite3Tolower(c);

        }else{
          cx = c;

        }



        while( (c2 = *(zString++))!=0 ){
          if( c2!=c && c2!=cx ) continue;
          bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
          if( bMatch!=SQLITE_NOMATCH ) return bMatch;
        }
      }else{
        int bMatch;
        while( (c2 = Utf8Read(zString))!=0 ){
          if( c2!=c ) continue;

      ** that point.
      **
      ** For a case-insensitive search, set variable cx to be the same as
      ** c but in the other case and search the input string for either
      ** c or cx.
      */
      if( c<=0x80 ){
        char zStop[3];
        int bMatch;
        if( noCase ){
          zStop[0] = sqlite3Toupper(c);
          zStop[1] = sqlite3Tolower(c);
          zStop[2] = 0;
        }else{
          zStop[0] = c;
          zStop[1] = 0;
        }
        while(1){
          zString += strcspn((const char*)zString, zStop);
          if( zString[0]==0 ) break;
          zString++;

          bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
          if( bMatch!=SQLITE_NOMATCH ) return bMatch;
        }
      }else{
        int bMatch;
        while( (c2 = Utf8Read(zString))!=0 ){
          if( c2!=c ) continue;

        sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
        pOp = sqlite3VdbeGetOp(v, -1);

        if( ALWAYS(pOp) && pOp->opcode==OP_Null && !IsVirtual(pTab) ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;
          pOp->p1 = iDataCur;
          pOp->p2 = regRowid;
          pOp->p3 = regAutoinc;
        }
      }
................................................................................
  ** there is no ORDER BY, we will get an error. */
  if( pSelect->pGroupBy ){
    return 0;   /* SELECT may not have a GROUP BY clause */
  }
  if( pSelect->pLimit ){
    return 0;   /* SELECT may not have a LIMIT clause */
  }
  assert( pSelect->pOffset==0 );  /* Must be so if pLimit==0 */
  if( pSelect->pPrior ){
    return 0;   /* SELECT may not be a compound query */
  }
  if( pSelect->selFlags & SF_Distinct ){
    return 0;   /* SELECT may not be DISTINCT */
  }
  pEList = pSelect->pEList;

        sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
        pOp = sqlite3VdbeGetOp(v, -1);
        assert( pOp!=0 );
        if( pOp->opcode==OP_Null && !IsVirtual(pTab) ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;
          pOp->p1 = iDataCur;
          pOp->p2 = regRowid;
          pOp->p3 = regAutoinc;
        }
      }
................................................................................
  ** there is no ORDER BY, we will get an error. */
  if( pSelect->pGroupBy ){
    return 0;   /* SELECT may not have a GROUP BY clause */
  }
  if( pSelect->pLimit ){
    return 0;   /* SELECT may not have a LIMIT clause */
  }

  if( pSelect->pPrior ){
    return 0;   /* SELECT may not be a compound query */
  }
  if( pSelect->selFlags & SF_Distinct ){
    return 0;   /* SELECT may not be DISTINCT */
  }
  pEList = pSelect->pEList;

      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
      case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;

      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
      case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;

#if defined(HAVE_LSTAT)
  { "lstat",         (sqlite3_syscall_ptr)lstat,          0 },
#else
  { "lstat",         (sqlite3_syscall_ptr)0,              0 },
#endif
#define osLstat      ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)


  { "ioctl",         (sqlite3_syscall_ptr)ioctl,          0 },



#define osIoctl ((int(*)(int,int,...))aSyscall[28].pCurrent)

}; /* End of the overrideable system calls */


/*
** On some systems, calls to fchown() will trigger a message in a security
................................................................................
  unixInodeInfo *pInode;     /* unixInodeInfo that owns this SHM node */
  sqlite3_mutex *mutex;      /* Mutex to access this object */
  char *zFilename;           /* Name of the mmapped file */
  int h;                     /* Open file descriptor */
  int szRegion;              /* Size of shared-memory regions */
  u16 nRegion;               /* Size of array apRegion */
  u8 isReadonly;             /* True if read-only */

  char **apRegion;           /* Array of mapped shared-memory regions */
  int nRef;                  /* Number of unixShm objects pointing to this */
  unixShm *pFirst;           /* All unixShm objects pointing to this */
#ifdef SQLITE_DEBUG
  u8 exclMask;               /* Mask of exclusive locks held */
  u8 sharedMask;             /* Mask of shared locks held */
  u8 nextShmId;              /* Next available unixShm.id value */
................................................................................
      robust_close(pFd, p->h, __LINE__);
      p->h = -1;
    }
    p->pInode->pShmNode = 0;
    sqlite3_free(p);
  }
}



























































/*
** Open a shared-memory area associated with open database file pDbFd.  
** This particular implementation uses mmapped files.
**
** The file used to implement shared-memory is in the same directory
** as the open database file and has the same name as the open database
................................................................................
** that no other processes are able to read or write the database.  In
** that case, we do not really need shared memory.  No shared memory
** file is created.  The shared memory will be simulated with heap memory.
*/
static int unixOpenSharedMemory(unixFile *pDbFd){
  struct unixShm *p = 0;          /* The connection to be opened */
  struct unixShmNode *pShmNode;   /* The underlying mmapped file */
  int rc;                         /* Result code */
  unixInodeInfo *pInode;          /* The inode of fd */
  char *zShmFilename;             /* Name of the file used for SHM */
  int nShmFilename;               /* Size of the SHM filename in bytes */

  /* Allocate space for the new unixShm object. */
  p = sqlite3_malloc64( sizeof(*p) );
  if( p==0 ) return SQLITE_NOMEM_BKPT;
  memset(p, 0, sizeof(*p));
  assert( pDbFd->pShm==0 );
................................................................................
#endif
    pShmNode = sqlite3_malloc64( sizeof(*pShmNode) + nShmFilename );
    if( pShmNode==0 ){
      rc = SQLITE_NOMEM_BKPT;
      goto shm_open_err;
    }
    memset(pShmNode, 0, sizeof(*pShmNode)+nShmFilename);
    zShmFilename = pShmNode->zFilename = (char*)&pShmNode[1];
#ifdef SQLITE_SHM_DIRECTORY
    sqlite3_snprintf(nShmFilename, zShmFilename, 
                     SQLITE_SHM_DIRECTORY "/sqlite-shm-%x-%x",
                     (u32)sStat.st_ino, (u32)sStat.st_dev);
#else
    sqlite3_snprintf(nShmFilename, zShmFilename, "%s-shm", zBasePath);
    sqlite3FileSuffix3(pDbFd->zPath, zShmFilename);
#endif
    pShmNode->h = -1;
    pDbFd->pInode->pShmNode = pShmNode;
    pShmNode->pInode = pDbFd->pInode;
    if( sqlite3GlobalConfig.bCoreMutex ){
      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
      if( pShmNode->mutex==0 ){
        rc = SQLITE_NOMEM_BKPT;
        goto shm_open_err;
      }
    }

    if( pInode->bProcessLock==0 ){
      int openFlags = O_RDWR | O_CREAT;
      if( sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
        openFlags = O_RDONLY;
        pShmNode->isReadonly = 1;

      }

      pShmNode->h = robust_open(zShmFilename, openFlags, (sStat.st_mode&0777));
      if( pShmNode->h<0 ){
        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
        goto shm_open_err;


      }

      /* If this process is running as root, make sure that the SHM file
      ** is owned by the same user that owns the original database.  Otherwise,
      ** the original owner will not be able to connect.
      */
      robustFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);
  
      /* Check to see if another process is holding the dead-man switch.
      ** If not, truncate the file to zero length. 
      */
      rc = SQLITE_OK;
      if( unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
        if( robust_ftruncate(pShmNode->h, 0) ){
          rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
        }
      }
      if( rc==SQLITE_OK ){
        rc = unixShmSystemLock(pDbFd, F_RDLCK, UNIX_SHM_DMS, 1);
      }
      if( rc ) goto shm_open_err;
    }
  }

  /* Make the new connection a child of the unixShmNode */
  p->pShmNode = pShmNode;
#ifdef SQLITE_DEBUG
  p->id = pShmNode->nextShmId++;
................................................................................
  ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex 
  ** mutex.
  */
  sqlite3_mutex_enter(pShmNode->mutex);
  p->pNext = pShmNode->pFirst;
  pShmNode->pFirst = p;
  sqlite3_mutex_leave(pShmNode->mutex);
  return SQLITE_OK;

  /* Jump here on any error */
shm_open_err:
  unixShmPurge(pDbFd);       /* This call frees pShmNode if required */
  sqlite3_free(p);
  unixLeaveMutex();
  return rc;
................................................................................
    rc = unixOpenSharedMemory(pDbFd);
    if( rc!=SQLITE_OK ) return rc;
  }

  p = pDbFd->pShm;
  pShmNode = p->pShmNode;
  sqlite3_mutex_enter(pShmNode->mutex);





  assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
  assert( pShmNode->pInode==pDbFd->pInode );
  assert( pShmNode->h>=0 || pDbFd->pInode->bProcessLock==1 );
  assert( pShmNode->h<0 || pDbFd->pInode->bProcessLock==0 );

  /* Minimum number of regions required to be mapped. */
  nReqRegion = ((iRegion+nShmPerMap) / nShmPerMap) * nShmPerMap;

#if defined(HAVE_LSTAT)
  { "lstat",         (sqlite3_syscall_ptr)lstat,          0 },
#else
  { "lstat",         (sqlite3_syscall_ptr)0,              0 },
#endif
#define osLstat      ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)

#if defined(__linux__) && defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
  { "ioctl",         (sqlite3_syscall_ptr)ioctl,          0 },
#else
  { "ioctl",         (sqlite3_syscall_ptr)0,              0 },
#endif
#define osIoctl ((int(*)(int,int,...))aSyscall[28].pCurrent)

}; /* End of the overrideable system calls */


/*
** On some systems, calls to fchown() will trigger a message in a security
................................................................................
  unixInodeInfo *pInode;     /* unixInodeInfo that owns this SHM node */
  sqlite3_mutex *mutex;      /* Mutex to access this object */
  char *zFilename;           /* Name of the mmapped file */
  int h;                     /* Open file descriptor */
  int szRegion;              /* Size of shared-memory regions */
  u16 nRegion;               /* Size of array apRegion */
  u8 isReadonly;             /* True if read-only */
  u8 isUnlocked;             /* True if no DMS lock held */
  char **apRegion;           /* Array of mapped shared-memory regions */
  int nRef;                  /* Number of unixShm objects pointing to this */
  unixShm *pFirst;           /* All unixShm objects pointing to this */
#ifdef SQLITE_DEBUG
  u8 exclMask;               /* Mask of exclusive locks held */
  u8 sharedMask;             /* Mask of shared locks held */
  u8 nextShmId;              /* Next available unixShm.id value */
................................................................................
      robust_close(pFd, p->h, __LINE__);
      p->h = -1;
    }
    p->pInode->pShmNode = 0;
    sqlite3_free(p);
  }
}

/*
** The DMS lock has not yet been taken on shm file pShmNode. Attempt to
** take it now. Return SQLITE_OK if successful, or an SQLite error
** code otherwise.
**
** If the DMS cannot be locked because this is a readonly_shm=1 
** connection and no other process already holds a lock, return
** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.
*/
static int unixLockSharedMemory(unixFile *pDbFd, unixShmNode *pShmNode){
  struct flock lock;
  int rc = SQLITE_OK;

  /* Use F_GETLK to determine the locks other processes are holding
  ** on the DMS byte. If it indicates that another process is holding
  ** a SHARED lock, then this process may also take a SHARED lock
  ** and proceed with opening the *-shm file. 
  **
  ** Or, if no other process is holding any lock, then this process
  ** is the first to open it. In this case take an EXCLUSIVE lock on the
  ** DMS byte and truncate the *-shm file to zero bytes in size. Then
  ** downgrade to a SHARED lock on the DMS byte.
  **
  ** If another process is holding an EXCLUSIVE lock on the DMS byte,
  ** return SQLITE_BUSY to the caller (it will try again). An earlier
  ** version of this code attempted the SHARED lock at this point. But
  ** this introduced a subtle race condition: if the process holding
  ** EXCLUSIVE failed just before truncating the *-shm file, then this
  ** process might open and use the *-shm file without truncating it.
  ** And if the *-shm file has been corrupted by a power failure or
  ** system crash, the database itself may also become corrupt.  */
  lock.l_whence = SEEK_SET;
  lock.l_start = UNIX_SHM_DMS;
  lock.l_len = 1;
  lock.l_type = F_WRLCK;
  if( osFcntl(pShmNode->h, F_GETLK, &lock)!=0 ) {
    rc = SQLITE_IOERR_LOCK;
  }else if( lock.l_type==F_UNLCK ){
    if( pShmNode->isReadonly ){
      pShmNode->isUnlocked = 1;
      rc = SQLITE_READONLY_CANTINIT;
    }else{
      rc = unixShmSystemLock(pDbFd, F_WRLCK, UNIX_SHM_DMS, 1);
      if( rc==SQLITE_OK && robust_ftruncate(pShmNode->h, 0) ){
        rc = unixLogError(SQLITE_IOERR_SHMOPEN,"ftruncate",pShmNode->zFilename);
      }
    }
  }else if( lock.l_type==F_WRLCK ){
    rc = SQLITE_BUSY;
  }

  if( rc==SQLITE_OK ){
    assert( lock.l_type==F_UNLCK || lock.l_type==F_RDLCK );
    rc = unixShmSystemLock(pDbFd, F_RDLCK, UNIX_SHM_DMS, 1);
  }
  return rc;
}

/*
** Open a shared-memory area associated with open database file pDbFd.  
** This particular implementation uses mmapped files.
**
** The file used to implement shared-memory is in the same directory
** as the open database file and has the same name as the open database
................................................................................
** that no other processes are able to read or write the database.  In
** that case, we do not really need shared memory.  No shared memory
** file is created.  The shared memory will be simulated with heap memory.
*/
static int unixOpenSharedMemory(unixFile *pDbFd){
  struct unixShm *p = 0;          /* The connection to be opened */
  struct unixShmNode *pShmNode;   /* The underlying mmapped file */
  int rc = SQLITE_OK;             /* Result code */
  unixInodeInfo *pInode;          /* The inode of fd */
  char *zShm;             /* Name of the file used for SHM */
  int nShmFilename;               /* Size of the SHM filename in bytes */

  /* Allocate space for the new unixShm object. */
  p = sqlite3_malloc64( sizeof(*p) );
  if( p==0 ) return SQLITE_NOMEM_BKPT;
  memset(p, 0, sizeof(*p));
  assert( pDbFd->pShm==0 );
................................................................................
#endif
    pShmNode = sqlite3_malloc64( sizeof(*pShmNode) + nShmFilename );
    if( pShmNode==0 ){
      rc = SQLITE_NOMEM_BKPT;
      goto shm_open_err;
    }
    memset(pShmNode, 0, sizeof(*pShmNode)+nShmFilename);
    zShm = pShmNode->zFilename = (char*)&pShmNode[1];
#ifdef SQLITE_SHM_DIRECTORY
    sqlite3_snprintf(nShmFilename, zShm, 
                     SQLITE_SHM_DIRECTORY "/sqlite-shm-%x-%x",
                     (u32)sStat.st_ino, (u32)sStat.st_dev);
#else
    sqlite3_snprintf(nShmFilename, zShm, "%s-shm", zBasePath);
    sqlite3FileSuffix3(pDbFd->zPath, zShm);
#endif
    pShmNode->h = -1;
    pDbFd->pInode->pShmNode = pShmNode;
    pShmNode->pInode = pDbFd->pInode;
    if( sqlite3GlobalConfig.bCoreMutex ){
      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
      if( pShmNode->mutex==0 ){
        rc = SQLITE_NOMEM_BKPT;
        goto shm_open_err;
      }
    }

    if( pInode->bProcessLock==0 ){

      if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){


        pShmNode->h = robust_open(zShm, O_RDWR|O_CREAT, (sStat.st_mode&0777));
      }
      if( pShmNode->h<0 ){
        pShmNode->h = robust_open(zShm, O_RDONLY, (sStat.st_mode&0777));
        if( pShmNode->h<0 ){
          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShm);
          goto shm_open_err;
        }
        pShmNode->isReadonly = 1;
      }

      /* If this process is running as root, make sure that the SHM file
      ** is owned by the same user that owns the original database.  Otherwise,
      ** the original owner will not be able to connect.
      */
      robustFchown(pShmNode->h, sStat.st_uid, sStat.st_gid);

      rc = unixLockSharedMemory(pDbFd, pShmNode);











      if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;
    }
  }

  /* Make the new connection a child of the unixShmNode */
  p->pShmNode = pShmNode;
#ifdef SQLITE_DEBUG
  p->id = pShmNode->nextShmId++;
................................................................................
  ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex 
  ** mutex.
  */
  sqlite3_mutex_enter(pShmNode->mutex);
  p->pNext = pShmNode->pFirst;
  pShmNode->pFirst = p;
  sqlite3_mutex_leave(pShmNode->mutex);
  return rc;

  /* Jump here on any error */
shm_open_err:
  unixShmPurge(pDbFd);       /* This call frees pShmNode if required */
  sqlite3_free(p);
  unixLeaveMutex();
  return rc;
................................................................................
    rc = unixOpenSharedMemory(pDbFd);
    if( rc!=SQLITE_OK ) return rc;
  }

  p = pDbFd->pShm;
  pShmNode = p->pShmNode;
  sqlite3_mutex_enter(pShmNode->mutex);
  if( pShmNode->isUnlocked ){
    rc = unixLockSharedMemory(pDbFd, pShmNode);
    if( rc!=SQLITE_OK ) goto shmpage_out;
    pShmNode->isUnlocked = 0;
  }
  assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );
  assert( pShmNode->pInode==pDbFd->pInode );
  assert( pShmNode->h>=0 || pDbFd->pInode->bProcessLock==1 );
  assert( pShmNode->h<0 || pDbFd->pInode->bProcessLock==0 );

  /* Minimum number of regions required to be mapped. */
  nReqRegion = ((iRegion+nShmPerMap) / nShmPerMap) * nShmPerMap;

struct winShmNode {
  sqlite3_mutex *mutex;      /* Mutex to access this object */
  char *zFilename;           /* Name of the file */
  winFile hFile;             /* File handle from winOpen */

  int szRegion;              /* Size of shared-memory regions */
  int nRegion;               /* Size of array apRegion */



  struct ShmRegion {
    HANDLE hMap;             /* File handle from CreateFileMapping */
    void *pMap;
  } *aRegion;
  DWORD lastErrno;           /* The Windows errno from the last I/O error */

  int nRef;                  /* Number of winShm objects pointing to this */
................................................................................
      sqlite3_free(p->aRegion);
      sqlite3_free(p);
    }else{
      pp = &p->pNext;
    }
  }
}
































/*
** Open the shared-memory area associated with database file pDbFd.
**
** When opening a new shared-memory file, if no other instances of that
** file are currently open, in this process or in other processes, then
** the file must be truncated to zero length or have its header cleared.
*/
static int winOpenSharedMemory(winFile *pDbFd){
  struct winShm *p;                  /* The connection to be opened */
  struct winShmNode *pShmNode = 0;   /* The underlying mmapped file */
  int rc;                            /* Result code */

  struct winShmNode *pNew;           /* Newly allocated winShmNode */
  int nName;                         /* Size of zName in bytes */

  assert( pDbFd->pShm==0 );    /* Not previously opened */

  /* Allocate space for the new sqlite3_shm object.  Also speculatively
  ** allocate space for a new winShmNode and filename.
  */
................................................................................
      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
      if( pShmNode->mutex==0 ){
        rc = SQLITE_IOERR_NOMEM_BKPT;
        goto shm_open_err;
      }
    }

    rc = winOpen(pDbFd->pVfs,
                 pShmNode->zFilename,             /* Name of the file (UTF-8) */
                 (sqlite3_file*)&pShmNode->hFile,  /* File handle here */
                 SQLITE_OPEN_WAL | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
                 0);
    if( SQLITE_OK!=rc ){
      goto shm_open_err;
    }

    /* Check to see if another process is holding the dead-man switch.
    ** If not, truncate the file to zero length.
    */
    if( winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1)==SQLITE_OK ){
      rc = winTruncate((sqlite3_file *)&pShmNode->hFile, 0);
      if( rc!=SQLITE_OK ){
        rc = winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
                         "winOpenShm", pDbFd->zPath);
      }
    }
    if( rc==SQLITE_OK ){
      winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
      rc = winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
    }
    if( rc ) goto shm_open_err;
  }

  /* Make the new connection a child of the winShmNode */
  p->pShmNode = pShmNode;
#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
  p->id = pShmNode->nextShmId++;
#endif
................................................................................
  ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
  ** mutex.
  */
  sqlite3_mutex_enter(pShmNode->mutex);
  p->pNext = pShmNode->pFirst;
  pShmNode->pFirst = p;
  sqlite3_mutex_leave(pShmNode->mutex);
  return SQLITE_OK;

  /* Jump here on any error */
shm_open_err:
  winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
  winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
  sqlite3_free(p);
  sqlite3_free(pNew);
................................................................................
  int szRegion,                   /* Size of regions */
  int isWrite,                    /* True to extend file if necessary */
  void volatile **pp              /* OUT: Mapped memory */
){
  winFile *pDbFd = (winFile*)fd;
  winShm *pShm = pDbFd->pShm;
  winShmNode *pShmNode;


  int rc = SQLITE_OK;

  if( !pShm ){
    rc = winOpenSharedMemory(pDbFd);
    if( rc!=SQLITE_OK ) return rc;
    pShm = pDbFd->pShm;
  }
  pShmNode = pShm->pShmNode;

  sqlite3_mutex_enter(pShmNode->mutex);





  assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );

  if( pShmNode->nRegion<=iRegion ){
    struct ShmRegion *apNew;           /* New aRegion[] array */
    int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
    sqlite3_int64 sz;                  /* Current size of wal-index file */

................................................................................
        pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
    );
    if( !apNew ){
      rc = SQLITE_IOERR_NOMEM_BKPT;
      goto shmpage_out;
    }
    pShmNode->aRegion = apNew;






    while( pShmNode->nRegion<=iRegion ){
      HANDLE hMap = NULL;         /* file-mapping handle */
      void *pMap = 0;             /* Mapped memory region */

#if SQLITE_OS_WINRT
      hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
          NULL, PAGE_READWRITE, nByte, NULL
      );
#elif defined(SQLITE_WIN32_HAS_WIDE)
      hMap = osCreateFileMappingW(pShmNode->hFile.h,
          NULL, PAGE_READWRITE, 0, nByte, NULL
      );
#elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
      hMap = osCreateFileMappingA(pShmNode->hFile.h,
          NULL, PAGE_READWRITE, 0, nByte, NULL
      );
#endif
      OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
               osGetCurrentProcessId(), pShmNode->nRegion, nByte,
               hMap ? "ok" : "failed"));
      if( hMap ){
        int iOffset = pShmNode->nRegion*szRegion;
        int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
#if SQLITE_OS_WINRT
        pMap = osMapViewOfFileFromApp(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
            iOffset - iOffsetShift, szRegion + iOffsetShift
        );
#else
        pMap = osMapViewOfFile(hMap, FILE_MAP_WRITE | FILE_MAP_READ,
            0, iOffset - iOffsetShift, szRegion + iOffsetShift
        );
#endif
        OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
                 osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
                 szRegion, pMap ? "ok" : "failed"));
      }
................................................................................
    int iOffset = iRegion*szRegion;
    int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
    char *p = (char *)pShmNode->aRegion[iRegion].pMap;
    *pp = (void *)&p[iOffsetShift];
  }else{
    *pp = 0;
  }

  sqlite3_mutex_leave(pShmNode->mutex);
  return rc;
}

#else
# define winShmMap     0
# define winShmLock    0

struct winShmNode {
  sqlite3_mutex *mutex;      /* Mutex to access this object */
  char *zFilename;           /* Name of the file */
  winFile hFile;             /* File handle from winOpen */

  int szRegion;              /* Size of shared-memory regions */
  int nRegion;               /* Size of array apRegion */
  u8 isReadonly;             /* True if read-only */
  u8 isUnlocked;             /* True if no DMS lock held */

  struct ShmRegion {
    HANDLE hMap;             /* File handle from CreateFileMapping */
    void *pMap;
  } *aRegion;
  DWORD lastErrno;           /* The Windows errno from the last I/O error */

  int nRef;                  /* Number of winShm objects pointing to this */
................................................................................
      sqlite3_free(p->aRegion);
      sqlite3_free(p);
    }else{
      pp = &p->pNext;
    }
  }
}

/*
** The DMS lock has not yet been taken on shm file pShmNode. Attempt to
** take it now. Return SQLITE_OK if successful, or an SQLite error
** code otherwise.
**
** If the DMS cannot be locked because this is a readonly_shm=1
** connection and no other process already holds a lock, return
** SQLITE_READONLY_CANTINIT and set pShmNode->isUnlocked=1.
*/
static int winLockSharedMemory(winShmNode *pShmNode){
  int rc = winShmSystemLock(pShmNode, WINSHM_WRLCK, WIN_SHM_DMS, 1);

  if( rc==SQLITE_OK ){
    if( pShmNode->isReadonly ){
      pShmNode->isUnlocked = 1;
      winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
      return SQLITE_READONLY_CANTINIT;
    }else if( winTruncate((sqlite3_file*)&pShmNode->hFile, 0) ){
      winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
      return winLogError(SQLITE_IOERR_SHMOPEN, osGetLastError(),
                         "winLockSharedMemory", pShmNode->zFilename);
    }
  }

  if( rc==SQLITE_OK ){
    winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
  }

  return winShmSystemLock(pShmNode, WINSHM_RDLCK, WIN_SHM_DMS, 1);
}

/*
** Open the shared-memory area associated with database file pDbFd.
**
** When opening a new shared-memory file, if no other instances of that
** file are currently open, in this process or in other processes, then
** the file must be truncated to zero length or have its header cleared.
*/
static int winOpenSharedMemory(winFile *pDbFd){
  struct winShm *p;                  /* The connection to be opened */
  winShmNode *pShmNode = 0;          /* The underlying mmapped file */
  int rc = SQLITE_OK;                /* Result code */
  int rc2 = SQLITE_ERROR;            /* winOpen result code */
  winShmNode *pNew;                  /* Newly allocated winShmNode */
  int nName;                         /* Size of zName in bytes */

  assert( pDbFd->pShm==0 );    /* Not previously opened */

  /* Allocate space for the new sqlite3_shm object.  Also speculatively
  ** allocate space for a new winShmNode and filename.
  */
................................................................................
      pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
      if( pShmNode->mutex==0 ){
        rc = SQLITE_IOERR_NOMEM_BKPT;
        goto shm_open_err;
      }
    }

    if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
      rc2 = winOpen(pDbFd->pVfs,
                    pShmNode->zFilename,
                    (sqlite3_file*)&pShmNode->hFile,
                    SQLITE_OPEN_WAL|SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE,
                    0);
    }
    if( rc2!=SQLITE_OK ){
      rc2 = winOpen(pDbFd->pVfs,
                    pShmNode->zFilename,
                    (sqlite3_file*)&pShmNode->hFile,
                    SQLITE_OPEN_WAL|SQLITE_OPEN_READONLY,
                    0);
      if( rc2!=SQLITE_OK ){
        rc = winLogError(rc2, osGetLastError(), "winOpenShm",
                         pShmNode->zFilename);
        goto shm_open_err;
      }
      pShmNode->isReadonly = 1;
    }

    rc = winLockSharedMemory(pShmNode);
    if( rc!=SQLITE_OK && rc!=SQLITE_READONLY_CANTINIT ) goto shm_open_err;

  }

  /* Make the new connection a child of the winShmNode */
  p->pShmNode = pShmNode;
#if defined(SQLITE_DEBUG) || defined(SQLITE_HAVE_OS_TRACE)
  p->id = pShmNode->nextShmId++;
#endif
................................................................................
  ** at pShmNode->pFirst. This must be done while holding the pShmNode->mutex
  ** mutex.
  */
  sqlite3_mutex_enter(pShmNode->mutex);
  p->pNext = pShmNode->pFirst;
  pShmNode->pFirst = p;
  sqlite3_mutex_leave(pShmNode->mutex);
  return rc;

  /* Jump here on any error */
shm_open_err:
  winShmSystemLock(pShmNode, WINSHM_UNLCK, WIN_SHM_DMS, 1);
  winShmPurge(pDbFd->pVfs, 0);      /* This call frees pShmNode if required */
  sqlite3_free(p);
  sqlite3_free(pNew);
................................................................................
  int szRegion,                   /* Size of regions */
  int isWrite,                    /* True to extend file if necessary */
  void volatile **pp              /* OUT: Mapped memory */
){
  winFile *pDbFd = (winFile*)fd;
  winShm *pShm = pDbFd->pShm;
  winShmNode *pShmNode;
  DWORD protect = PAGE_READWRITE;
  DWORD flags = FILE_MAP_WRITE | FILE_MAP_READ;
  int rc = SQLITE_OK;

  if( !pShm ){
    rc = winOpenSharedMemory(pDbFd);
    if( rc!=SQLITE_OK ) return rc;
    pShm = pDbFd->pShm;
  }
  pShmNode = pShm->pShmNode;

  sqlite3_mutex_enter(pShmNode->mutex);
  if( pShmNode->isUnlocked ){
    rc = winLockSharedMemory(pShmNode);
    if( rc!=SQLITE_OK ) goto shmpage_out;
    pShmNode->isUnlocked = 0;
  }
  assert( szRegion==pShmNode->szRegion || pShmNode->nRegion==0 );

  if( pShmNode->nRegion<=iRegion ){
    struct ShmRegion *apNew;           /* New aRegion[] array */
    int nByte = (iRegion+1)*szRegion;  /* Minimum required file size */
    sqlite3_int64 sz;                  /* Current size of wal-index file */

................................................................................
        pShmNode->aRegion, (iRegion+1)*sizeof(apNew[0])
    );
    if( !apNew ){
      rc = SQLITE_IOERR_NOMEM_BKPT;
      goto shmpage_out;
    }
    pShmNode->aRegion = apNew;

    if( pShmNode->isReadonly ){
      protect = PAGE_READONLY;
      flags = FILE_MAP_READ;
    }

    while( pShmNode->nRegion<=iRegion ){
      HANDLE hMap = NULL;         /* file-mapping handle */
      void *pMap = 0;             /* Mapped memory region */

#if SQLITE_OS_WINRT
      hMap = osCreateFileMappingFromApp(pShmNode->hFile.h,
          NULL, protect, nByte, NULL
      );
#elif defined(SQLITE_WIN32_HAS_WIDE)
      hMap = osCreateFileMappingW(pShmNode->hFile.h,
          NULL, protect, 0, nByte, NULL
      );
#elif defined(SQLITE_WIN32_HAS_ANSI) && SQLITE_WIN32_CREATEFILEMAPPINGA
      hMap = osCreateFileMappingA(pShmNode->hFile.h,
          NULL, protect, 0, nByte, NULL
      );
#endif
      OSTRACE(("SHM-MAP-CREATE pid=%lu, region=%d, size=%d, rc=%s\n",
               osGetCurrentProcessId(), pShmNode->nRegion, nByte,
               hMap ? "ok" : "failed"));
      if( hMap ){
        int iOffset = pShmNode->nRegion*szRegion;
        int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
#if SQLITE_OS_WINRT
        pMap = osMapViewOfFileFromApp(hMap, flags,
            iOffset - iOffsetShift, szRegion + iOffsetShift
        );
#else
        pMap = osMapViewOfFile(hMap, flags,
            0, iOffset - iOffsetShift, szRegion + iOffsetShift
        );
#endif
        OSTRACE(("SHM-MAP-MAP pid=%lu, region=%d, offset=%d, size=%d, rc=%s\n",
                 osGetCurrentProcessId(), pShmNode->nRegion, iOffset,
                 szRegion, pMap ? "ok" : "failed"));
      }
................................................................................
    int iOffset = iRegion*szRegion;
    int iOffsetShift = iOffset % winSysInfo.dwAllocationGranularity;
    char *p = (char *)pShmNode->aRegion[iRegion].pMap;
    *pp = (void *)&p[iOffsetShift];
  }else{
    *pp = 0;
  }
  if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;
  sqlite3_mutex_leave(pShmNode->mutex);
  return rc;
}

#else
# define winShmMap     0
# define winShmLock    0

#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
  int dc;                           /* Device characteristics */

  assert( isOpen(pPager->fd) );
  dc = sqlite3OsDeviceCharacteristics(pPager->fd);


#endif

#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
  if( dc&SQLITE_IOCAP_BATCH_ATOMIC ){
    return -1;
  }
#endif

#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
  int dc;                           /* Device characteristics */

  assert( isOpen(pPager->fd) );
  dc = sqlite3OsDeviceCharacteristics(pPager->fd);
#else
  UNUSED_PARAMETER(pPager);
#endif

#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE
  if( dc&SQLITE_IOCAP_BATCH_ATOMIC ){
    return -1;
  }
#endif

/*
** Alternative datatype for the argument to the malloc() routine passed
** into sqlite3ParserAlloc().  The default is size_t.
*/
#define YYMALLOCARGTYPE  u64

/*
** An instance of this structure holds information about the
** LIMIT clause of a SELECT statement.
*/
struct LimitVal {
  Expr *pLimit;    /* The LIMIT expression.  NULL if there is no limit */
  Expr *pOffset;   /* The OFFSET expression.  NULL if there is none */
};

/*
** An instance of the following structure describes the event of a
** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
** TK_DELETE, or TK_INSTEAD.  If the event is of the form
**
**      UPDATE ON (a,b,c)
**
................................................................................
  Select *pLhs = A;
  if( pRhs && pRhs->pPrior ){
    SrcList *pFrom;
    Token x;
    x.n = 0;
    parserDoubleLinkSelect(pParse, pRhs);
    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0,0);
  }
  if( pRhs ){
    pRhs->op = (u8)Y;
    pRhs->pPrior = pLhs;
    if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;
    pRhs->selFlags &= ~SF_MultiValue;
    if( Y!=TK_ALL ) pParse->hasCompound = 1;
................................................................................
multiselect_op(A) ::= EXCEPT|INTERSECT(OP).  {A = @OP; /*A-overwrites-OP*/}
%endif SQLITE_OMIT_COMPOUND_SELECT
oneselect(A) ::= SELECT(S) distinct(D) selcollist(W) from(X) where_opt(Y)
                 groupby_opt(P) having_opt(Q) orderby_opt(Z) limit_opt(L). {
#if SELECTTRACE_ENABLED
  Token s = S; /*A-overwrites-S*/
#endif
  A = sqlite3SelectNew(pParse,W,X,Y,P,Q,Z,D,L.pLimit,L.pOffset);
#if SELECTTRACE_ENABLED
  /* Populate the Select.zSelName[] string that is used to help with
  ** query planner debugging, to differentiate between multiple Select
  ** objects in a complex query.
  **
  ** If the SELECT keyword is immediately followed by a C-style comment
  ** then extract the first few alphanumeric characters from within that
................................................................................
#endif /* SELECTRACE_ENABLED */
}
oneselect(A) ::= values(A).

%type values {Select*}
%destructor values {sqlite3SelectDelete(pParse->db, $$);}
values(A) ::= VALUES LP nexprlist(X) RP. {
  A = sqlite3SelectNew(pParse,X,0,0,0,0,0,SF_Values,0,0);
}
values(A) ::= values(A) COMMA LP exprlist(Y) RP. {
  Select *pRight, *pLeft = A;
  pRight = sqlite3SelectNew(pParse,Y,0,0,0,0,0,SF_Values|SF_MultiValue,0,0);
  if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;
  if( pRight ){
    pRight->op = TK_ALL;
    pRight->pPrior = pLeft;
    A = pRight;
  }else{
    A = pLeft;
................................................................................
        pOld->zName = pOld->zDatabase = 0;
        pOld->pSelect = 0;
      }
      sqlite3SrcListDelete(pParse->db, F);
    }else{
      Select *pSubquery;
      sqlite3SrcListShiftJoinType(F);
      pSubquery = sqlite3SelectNew(pParse,0,F,0,0,0,0,SF_NestedFrom,0,0);
      A = sqlite3SrcListAppendFromTerm(pParse,A,0,0,&Z,pSubquery,N,U);
    }
  }
%endif  SQLITE_OMIT_SUBQUERY

%type dbnm {Token}
dbnm(A) ::= .          {A.z=0; A.n=0;}
................................................................................
groupby_opt(A) ::= GROUP BY nexprlist(X). {A = X;}

%type having_opt {Expr*}
%destructor having_opt {sqlite3ExprDelete(pParse->db, $$);}
having_opt(A) ::= .                {A = 0;}
having_opt(A) ::= HAVING expr(X).  {A = X.pExpr;}

%type limit_opt {struct LimitVal}

// The destructor for limit_opt will never fire in the current grammar.
// The limit_opt non-terminal only occurs at the end of a single production
// rule for SELECT statements.  As soon as the rule that create the 
// limit_opt non-terminal reduces, the SELECT statement rule will also
// reduce.  So there is never a limit_opt non-terminal on the stack 
// except as a transient.  So there is never anything to destroy.
//
//%destructor limit_opt {
//  sqlite3ExprDelete(pParse->db, $$.pLimit);
//  sqlite3ExprDelete(pParse->db, $$.pOffset);
//}
limit_opt(A) ::= .                    {A.pLimit = 0; A.pOffset = 0;}
limit_opt(A) ::= LIMIT expr(X).       {A.pLimit = X.pExpr; A.pOffset = 0;}
limit_opt(A) ::= LIMIT expr(X) OFFSET expr(Y). 
                                      {A.pLimit = X.pExpr; A.pOffset = Y.pExpr;}
limit_opt(A) ::= LIMIT expr(X) COMMA expr(Y). 
                                      {A.pOffset = X.pExpr; A.pLimit = Y.pExpr;}

/////////////////////////// The DELETE statement /////////////////////////////
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W) 
        orderby_opt(O) limit_opt(L). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  W = sqlite3LimitWhere(pParse, X, W, O, L.pLimit, L.pOffset, "DELETE");
  sqlite3DeleteFrom(pParse,X,W);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3DeleteFrom(pParse,X,W);
}
%endif

%type where_opt {Expr*}
%destructor where_opt {sqlite3ExprDelete(pParse->db, $$);}

where_opt(A) ::= .                    {A = 0;}
................................................................................
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W) orderby_opt(O) limit_opt(L).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  W = sqlite3LimitWhere(pParse, X, W, O, L.pLimit, L.pOffset, "UPDATE");
  sqlite3Update(pParse,X,Y,W,R);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  sqlite3Update(pParse,X,Y,W,R);
}
%endif

%type setlist {ExprList*}
%destructor setlist {sqlite3ExprListDelete(pParse->db, $$);}

setlist(A) ::= setlist(A) COMMA nm(X) EQ expr(Y). {
................................................................................
    A.pExpr = sqlite3PExpr(pParse, TK_IN, A.pExpr, 0);
    sqlite3PExprAddSelect(pParse, A.pExpr, Y);
    exprNot(pParse, N, &A);
    A.zEnd = &E.z[E.n];
  }
  expr(A) ::= expr(A) in_op(N) nm(Y) dbnm(Z) paren_exprlist(E). [IN] {
    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&Y,&Z);
    Select *pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
    if( E )  sqlite3SrcListFuncArgs(pParse, pSelect ? pSrc : 0, E);
    A.pExpr = sqlite3PExpr(pParse, TK_IN, A.pExpr, 0);
    sqlite3PExprAddSelect(pParse, A.pExpr, pSelect);
    exprNot(pParse, N, &A);
    A.zEnd = Z.z ? &Z.z[Z.n] : &Y.z[Y.n];
  }
  expr(A) ::= EXISTS(B) LP select(Y) RP(E). {

/*
** Alternative datatype for the argument to the malloc() routine passed
** into sqlite3ParserAlloc().  The default is size_t.
*/
#define YYMALLOCARGTYPE  u64










/*
** An instance of the following structure describes the event of a
** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
** TK_DELETE, or TK_INSTEAD.  If the event is of the form
**
**      UPDATE ON (a,b,c)
**
................................................................................
  Select *pLhs = A;
  if( pRhs && pRhs->pPrior ){
    SrcList *pFrom;
    Token x;
    x.n = 0;
    parserDoubleLinkSelect(pParse, pRhs);
    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0);
  }
  if( pRhs ){
    pRhs->op = (u8)Y;
    pRhs->pPrior = pLhs;
    if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;
    pRhs->selFlags &= ~SF_MultiValue;
    if( Y!=TK_ALL ) pParse->hasCompound = 1;
................................................................................
multiselect_op(A) ::= EXCEPT|INTERSECT(OP).  {A = @OP; /*A-overwrites-OP*/}
%endif SQLITE_OMIT_COMPOUND_SELECT
oneselect(A) ::= SELECT(S) distinct(D) selcollist(W) from(X) where_opt(Y)
                 groupby_opt(P) having_opt(Q) orderby_opt(Z) limit_opt(L). {
#if SELECTTRACE_ENABLED
  Token s = S; /*A-overwrites-S*/
#endif
  A = sqlite3SelectNew(pParse,W,X,Y,P,Q,Z,D,L);
#if SELECTTRACE_ENABLED
  /* Populate the Select.zSelName[] string that is used to help with
  ** query planner debugging, to differentiate between multiple Select
  ** objects in a complex query.
  **
  ** If the SELECT keyword is immediately followed by a C-style comment
  ** then extract the first few alphanumeric characters from within that
................................................................................
#endif /* SELECTRACE_ENABLED */
}
oneselect(A) ::= values(A).

%type values {Select*}
%destructor values {sqlite3SelectDelete(pParse->db, $$);}
values(A) ::= VALUES LP nexprlist(X) RP. {
  A = sqlite3SelectNew(pParse,X,0,0,0,0,0,SF_Values,0);
}
values(A) ::= values(A) COMMA LP exprlist(Y) RP. {
  Select *pRight, *pLeft = A;
  pRight = sqlite3SelectNew(pParse,Y,0,0,0,0,0,SF_Values|SF_MultiValue,0);
  if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;
  if( pRight ){
    pRight->op = TK_ALL;
    pRight->pPrior = pLeft;
    A = pRight;
  }else{
    A = pLeft;
................................................................................
        pOld->zName = pOld->zDatabase = 0;
        pOld->pSelect = 0;
      }
      sqlite3SrcListDelete(pParse->db, F);
    }else{
      Select *pSubquery;
      sqlite3SrcListShiftJoinType(F);
      pSubquery = sqlite3SelectNew(pParse,0,F,0,0,0,0,SF_NestedFrom,0);
      A = sqlite3SrcListAppendFromTerm(pParse,A,0,0,&Z,pSubquery,N,U);
    }
  }
%endif  SQLITE_OMIT_SUBQUERY

%type dbnm {Token}
dbnm(A) ::= .          {A.z=0; A.n=0;}
................................................................................
groupby_opt(A) ::= GROUP BY nexprlist(X). {A = X;}

%type having_opt {Expr*}
%destructor having_opt {sqlite3ExprDelete(pParse->db, $$);}
having_opt(A) ::= .                {A = 0;}
having_opt(A) ::= HAVING expr(X).  {A = X.pExpr;}

%type limit_opt {Expr*}

// The destructor for limit_opt will never fire in the current grammar.
// The limit_opt non-terminal only occurs at the end of a single production
// rule for SELECT statements.  As soon as the rule that create the 
// limit_opt non-terminal reduces, the SELECT statement rule will also
// reduce.  So there is never a limit_opt non-terminal on the stack 
// except as a transient.  So there is never anything to destroy.
//
//%destructor limit_opt {sqlite3ExprDelete(pParse->db, $$);}
limit_opt(A) ::= .       {A = 0;}
limit_opt(A) ::= LIMIT expr(X).
                         {A = sqlite3PExpr(pParse,TK_LIMIT,X.pExpr,0);}
limit_opt(A) ::= LIMIT expr(X) OFFSET expr(Y). 
                         {A = sqlite3PExpr(pParse,TK_LIMIT,X.pExpr,Y.pExpr);}
limit_opt(A) ::= LIMIT expr(X) COMMA expr(Y). 
                         {A = sqlite3PExpr(pParse,TK_LIMIT,Y.pExpr,X.pExpr);}



/////////////////////////// The DELETE statement /////////////////////////////
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W) 
        orderby_opt(O) limit_opt(L). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);

  sqlite3DeleteFrom(pParse,X,W,O,L);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) DELETE FROM fullname(X) indexed_opt(I) where_opt(W). {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3DeleteFrom(pParse,X,W,0,0);
}
%endif

%type where_opt {Expr*}
%destructor where_opt {sqlite3ExprDelete(pParse->db, $$);}

where_opt(A) ::= .                    {A = 0;}
................................................................................
//
%ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W) orderby_opt(O) limit_opt(L).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 

  sqlite3Update(pParse,X,Y,W,R,O,L);
}
%endif
%ifndef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
cmd ::= with(C) UPDATE orconf(R) fullname(X) indexed_opt(I) SET setlist(Y)
        where_opt(W).  {
  sqlite3WithPush(pParse, C, 1);
  sqlite3SrcListIndexedBy(pParse, X, &I);
  sqlite3ExprListCheckLength(pParse,Y,"set list"); 
  sqlite3Update(pParse,X,Y,W,R,0,0);
}
%endif

%type setlist {ExprList*}
%destructor setlist {sqlite3ExprListDelete(pParse->db, $$);}

setlist(A) ::= setlist(A) COMMA nm(X) EQ expr(Y). {
................................................................................
    A.pExpr = sqlite3PExpr(pParse, TK_IN, A.pExpr, 0);
    sqlite3PExprAddSelect(pParse, A.pExpr, Y);
    exprNot(pParse, N, &A);
    A.zEnd = &E.z[E.n];
  }
  expr(A) ::= expr(A) in_op(N) nm(Y) dbnm(Z) paren_exprlist(E). [IN] {
    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&Y,&Z);
    Select *pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0);
    if( E )  sqlite3SrcListFuncArgs(pParse, pSelect ? pSrc : 0, E);
    A.pExpr = sqlite3PExpr(pParse, TK_IN, A.pExpr, 0);
    sqlite3PExprAddSelect(pParse, A.pExpr, pSelect);
    exprNot(pParse, N, &A);
    A.zEnd = Z.z ? &Z.z[Z.n] : &Y.z[Y.n];
  }
  expr(A) ::= EXISTS(B) LP select(Y) RP(E). {

/*
** Make sure the page is marked as clean. If it isn't clean already,
** make it so.
*/
void sqlite3PcacheMakeClean(PgHdr *p){
  assert( sqlite3PcachePageSanity(p) );
  if( ALWAYS((p->flags & PGHDR_DIRTY)!=0) ){
    assert( (p->flags & PGHDR_CLEAN)==0 );
    pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
    p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE);
    p->flags |= PGHDR_CLEAN;
    pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno));
    assert( sqlite3PcachePageSanity(p) );
    if( p->nRef==0 ){
      pcacheUnpin(p);
    }
  }
}

/*
** Make every page in the cache clean.
*/
void sqlite3PcacheCleanAll(PCache *pCache){

/*
** Make sure the page is marked as clean. If it isn't clean already,
** make it so.
*/
void sqlite3PcacheMakeClean(PgHdr *p){
  assert( sqlite3PcachePageSanity(p) );
  assert( (p->flags & PGHDR_DIRTY)!=0 );
  assert( (p->flags & PGHDR_CLEAN)==0 );
  pcacheManageDirtyList(p, PCACHE_DIRTYLIST_REMOVE);
  p->flags &= ~(PGHDR_DIRTY|PGHDR_NEED_SYNC|PGHDR_WRITEABLE);
  p->flags |= PGHDR_CLEAN;
  pcacheTrace(("%p.CLEAN %d\n",p->pCache,p->pgno));
  assert( sqlite3PcachePageSanity(p) );
  if( p->nRef==0 ){
    pcacheUnpin(p);

  }
}

/*
** Make every page in the cache clean.
*/
void sqlite3PcacheCleanAll(PCache *pCache){

  ** We return -1000000 instead of the more usual -1 simply because using
  ** -1000000 as the incorrect index into db->aDb[] is much 
  ** more likely to cause a segfault than -1 (of course there are assert()
  ** statements too, but it never hurts to play the odds).
  */
  assert( sqlite3_mutex_held(db->mutex) );
  if( pSchema ){
    for(i=0; ALWAYS(i<db->nDb); i++){

      if( db->aDb[i].pSchema==pSchema ){
        break;
      }
    }
    assert( i>=0 && i<db->nDb );
  }
  return i;

  ** We return -1000000 instead of the more usual -1 simply because using
  ** -1000000 as the incorrect index into db->aDb[] is much 
  ** more likely to cause a segfault than -1 (of course there are assert()
  ** statements too, but it never hurts to play the odds).
  */
  assert( sqlite3_mutex_held(db->mutex) );
  if( pSchema ){
    for(i=0; 1; i++){
      assert( i<db->nDb );
      if( db->aDb[i].pSchema==pSchema ){
        break;
      }
    }
    assert( i>=0 && i<db->nDb );
  }
  return i;

  StrAccum acc;
  char zBuf[500];
  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
  va_start(ap,zFormat);
  sqlite3VXPrintf(&acc, zFormat, ap);
  va_end(ap);
  sqlite3StrAccumFinish(&acc);






  fprintf(stdout,"%s", zBuf);
  fflush(stdout);

}
#endif


/*
** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.

  StrAccum acc;
  char zBuf[500];
  sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
  va_start(ap,zFormat);
  sqlite3VXPrintf(&acc, zFormat, ap);
  va_end(ap);
  sqlite3StrAccumFinish(&acc);
#ifdef SQLITE_OS_TRACE_PROC
  {
    extern void SQLITE_OS_TRACE_PROC(const char *zBuf, int nBuf);
    SQLITE_OS_TRACE_PROC(zBuf, sizeof(zBuf));
  }
#else
  fprintf(stdout,"%s", zBuf);
  fflush(stdout);
#endif
}
#endif


/*
** variable-argument wrapper around sqlite3VXPrintf().  The bFlags argument
** can contain the bit SQLITE_PRINTF_INTERNAL enable internal formats.

    ** column in the FROM clause.  This is used by the LIMIT and ORDER BY
    ** clause processing on UPDATE and DELETE statements.
    */
    case TK_ROW: {
      SrcList *pSrcList = pNC->pSrcList;
      struct SrcList_item *pItem;
      assert( pSrcList && pSrcList->nSrc==1 );
      pItem = pSrcList->a; 

      pExpr->op = TK_COLUMN;
      pExpr->pTab = pItem->pTab;
      pExpr->iTable = pItem->iCursor;
      pExpr->iColumn = -1;
      pExpr->affinity = SQLITE_AFF_INTEGER;
      break;
    }
................................................................................
  ExprList *pEList;
  sqlite3 *db;
  int moreToDo = 1;

  pOrderBy = pSelect->pOrderBy;
  if( pOrderBy==0 ) return 0;
  db = pParse->db;
#if SQLITE_MAX_COLUMN
  if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
    return 1;
  }
#endif
  for(i=0; i<pOrderBy->nExpr; i++){
    pOrderBy->a[i].done = 0;
  }
  pSelect->pNext = 0;
  while( pSelect->pPrior ){
    pSelect->pPrior->pNext = pSelect;
    pSelect = pSelect->pPrior;
................................................................................
){
  int i;
  sqlite3 *db = pParse->db;
  ExprList *pEList;
  struct ExprList_item *pItem;

  if( pOrderBy==0 || pParse->db->mallocFailed ) return 0;
#if SQLITE_MAX_COLUMN
  if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
    return 1;
  }
#endif
  pEList = pSelect->pEList;
  assert( pEList!=0 );  /* sqlite3SelectNew() guarantees this */
  for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
    if( pItem->u.x.iOrderByCol ){
      if( pItem->u.x.iOrderByCol>pEList->nExpr ){
        resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
        return 1;
................................................................................
    p->selFlags |= SF_Resolved;

    /* Resolve the expressions in the LIMIT and OFFSET clauses. These
    ** are not allowed to refer to any names, so pass an empty NameContext.
    */
    memset(&sNC, 0, sizeof(sNC));
    sNC.pParse = pParse;
    if( sqlite3ResolveExprNames(&sNC, p->pLimit) ||
        sqlite3ResolveExprNames(&sNC, p->pOffset) ){
      return WRC_Abort;
    }

    /* If the SF_Converted flags is set, then this Select object was
    ** was created by the convertCompoundSelectToSubquery() function.
    ** In this case the ORDER BY clause (p->pOrderBy) should be resolved
    ** as if it were part of the sub-query, not the parent. This block

    ** column in the FROM clause.  This is used by the LIMIT and ORDER BY
    ** clause processing on UPDATE and DELETE statements.
    */
    case TK_ROW: {
      SrcList *pSrcList = pNC->pSrcList;
      struct SrcList_item *pItem;
      assert( pSrcList && pSrcList->nSrc==1 );
      pItem = pSrcList->a;
      assert( HasRowid(pItem->pTab) && pItem->pTab->pSelect==0 );
      pExpr->op = TK_COLUMN;
      pExpr->pTab = pItem->pTab;
      pExpr->iTable = pItem->iCursor;
      pExpr->iColumn = -1;
      pExpr->affinity = SQLITE_AFF_INTEGER;
      break;
    }
................................................................................
  ExprList *pEList;
  sqlite3 *db;
  int moreToDo = 1;

  pOrderBy = pSelect->pOrderBy;
  if( pOrderBy==0 ) return 0;
  db = pParse->db;

  if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
    return 1;
  }

  for(i=0; i<pOrderBy->nExpr; i++){
    pOrderBy->a[i].done = 0;
  }
  pSelect->pNext = 0;
  while( pSelect->pPrior ){
    pSelect->pPrior->pNext = pSelect;
    pSelect = pSelect->pPrior;
................................................................................
){
  int i;
  sqlite3 *db = pParse->db;
  ExprList *pEList;
  struct ExprList_item *pItem;

  if( pOrderBy==0 || pParse->db->mallocFailed ) return 0;

  if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
    return 1;
  }

  pEList = pSelect->pEList;
  assert( pEList!=0 );  /* sqlite3SelectNew() guarantees this */
  for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
    if( pItem->u.x.iOrderByCol ){
      if( pItem->u.x.iOrderByCol>pEList->nExpr ){
        resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
        return 1;
................................................................................
    p->selFlags |= SF_Resolved;

    /* Resolve the expressions in the LIMIT and OFFSET clauses. These
    ** are not allowed to refer to any names, so pass an empty NameContext.
    */
    memset(&sNC, 0, sizeof(sNC));
    sNC.pParse = pParse;
    if( sqlite3ResolveExprNames(&sNC, p->pLimit) ){

      return WRC_Abort;
    }

    /* If the SF_Converted flags is set, then this Select object was
    ** was created by the convertCompoundSelectToSubquery() function.
    ** In this case the ORDER BY clause (p->pOrderBy) should be resolved
    ** as if it were part of the sub-query, not the parent. This block

    sqlite3ExprListDelete(db, p->pEList);
    sqlite3SrcListDelete(db, p->pSrc);
    sqlite3ExprDelete(db, p->pWhere);
    sqlite3ExprListDelete(db, p->pGroupBy);
    sqlite3ExprDelete(db, p->pHaving);
    sqlite3ExprListDelete(db, p->pOrderBy);
    sqlite3ExprDelete(db, p->pLimit);
    sqlite3ExprDelete(db, p->pOffset);
    if( OK_IF_ALWAYS_TRUE(p->pWith) ) sqlite3WithDelete(db, p->pWith);
    if( bFree ) sqlite3DbFreeNN(db, p);
    p = pPrior;
    bFree = 1;
  }
}

................................................................................
  ExprList *pEList,     /* which columns to include in the result */
  SrcList *pSrc,        /* the FROM clause -- which tables to scan */
  Expr *pWhere,         /* the WHERE clause */
  ExprList *pGroupBy,   /* the GROUP BY clause */
  Expr *pHaving,        /* the HAVING clause */
  ExprList *pOrderBy,   /* the ORDER BY clause */
  u32 selFlags,         /* Flag parameters, such as SF_Distinct */
  Expr *pLimit,         /* LIMIT value.  NULL means not used */
  Expr *pOffset         /* OFFSET value.  NULL means no offset */
){
  Select *pNew;
  Select standin;
  pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
  if( pNew==0 ){
    assert( pParse->db->mallocFailed );
    pNew = &standin;
................................................................................
  pNew->pWhere = pWhere;
  pNew->pGroupBy = pGroupBy;
  pNew->pHaving = pHaving;
  pNew->pOrderBy = pOrderBy;
  pNew->pPrior = 0;
  pNew->pNext = 0;
  pNew->pLimit = pLimit;
  pNew->pOffset = pOffset;
  pNew->pWith = 0;
  assert( pOffset==0 || pLimit!=0 || pParse->nErr>0
                     || pParse->db->mallocFailed!=0 );
  if( pParse->db->mallocFailed ) {
    clearSelect(pParse->db, pNew, pNew!=&standin);
    pNew = 0;
  }else{
    assert( pNew->pSrc!=0 || pParse->nErr>0 );
  }
  assert( pNew!=&standin );
................................................................................
  Hash ht;                    /* Hash table of column names */

  sqlite3HashInit(&ht);
  if( pEList ){
    nCol = pEList->nExpr;
    aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
    testcase( aCol==0 );

  }else{
    nCol = 0;
    aCol = 0;
  }
  assert( nCol==(i16)nCol );
  *pnCol = nCol;
  *paCol = aCol;
................................................................................
  }
  return sqlite3VdbeCreate(pParse);
}


/*
** Compute the iLimit and iOffset fields of the SELECT based on the
** pLimit and pOffset expressions.  pLimit and pOffset hold the expressions
** that appear in the original SQL statement after the LIMIT and OFFSET
** keywords.  Or NULL if those keywords are omitted. iLimit and iOffset 
** are the integer memory register numbers for counters used to compute 
** the limit and offset.  If there is no limit and/or offset, then 
** iLimit and iOffset are negative.
**
** This routine changes the values of iLimit and iOffset only if
** a limit or offset is defined by pLimit and pOffset.  iLimit and
** iOffset should have been preset to appropriate default values (zero)
** prior to calling this routine.
**
** The iOffset register (if it exists) is initialized to the value
** of the OFFSET.  The iLimit register is initialized to LIMIT.  Register
** iOffset+1 is initialized to LIMIT+OFFSET.
**
** Only if pLimit!=0 or pOffset!=0 do the limit registers get
** redefined.  The UNION ALL operator uses this property to force
** the reuse of the same limit and offset registers across multiple
** SELECT statements.
*/
static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
  Vdbe *v = 0;
  int iLimit = 0;
  int iOffset;
  int n;


  if( p->iLimit ) return;

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** controversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
  */
  sqlite3ExprCacheClear(pParse);
  assert( p->pOffset==0 || p->pLimit!=0 );
  if( p->pLimit ){

    p->iLimit = iLimit = ++pParse->nMem;
    v = sqlite3GetVdbe(pParse);
    assert( v!=0 );
    if( sqlite3ExprIsInteger(p->pLimit, &n) ){
      sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
      VdbeComment((v, "LIMIT counter"));
      if( n==0 ){
        sqlite3VdbeGoto(v, iBreak);
      }else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){
        p->nSelectRow = sqlite3LogEst((u64)n);
        p->selFlags |= SF_FixedLimit;
      }
    }else{
      sqlite3ExprCode(pParse, p->pLimit, iLimit);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
      VdbeComment((v, "LIMIT counter"));
      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
    }
    if( p->pOffset ){
      p->iOffset = iOffset = ++pParse->nMem;
      pParse->nMem++;   /* Allocate an extra register for limit+offset */
      sqlite3ExprCode(pParse, p->pOffset, iOffset);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
      VdbeComment((v, "OFFSET counter"));
      sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);
      VdbeComment((v, "LIMIT+OFFSET"));
    }
  }
}
................................................................................
  int iQueue;                   /* The Queue table */
  int iDistinct = 0;            /* To ensure unique results if UNION */
  int eDest = SRT_Fifo;         /* How to write to Queue */
  SelectDest destQueue;         /* SelectDest targetting the Queue table */
  int i;                        /* Loop counter */
  int rc;                       /* Result code */
  ExprList *pOrderBy;           /* The ORDER BY clause */
  Expr *pLimit, *pOffset;       /* Saved LIMIT and OFFSET */
  int regLimit, regOffset;      /* Registers used by LIMIT and OFFSET */

  /* Obtain authorization to do a recursive query */
  if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;

  /* Process the LIMIT and OFFSET clauses, if they exist */
  addrBreak = sqlite3VdbeMakeLabel(v);
  p->nSelectRow = 320;  /* 4 billion rows */
  computeLimitRegisters(pParse, p, addrBreak);
  pLimit = p->pLimit;
  pOffset = p->pOffset;
  regLimit = p->iLimit;
  regOffset = p->iOffset;
  p->pLimit = p->pOffset = 0;
  p->iLimit = p->iOffset = 0;
  pOrderBy = p->pOrderBy;

  /* Locate the cursor number of the Current table */
  for(i=0; ALWAYS(i<pSrc->nSrc); i++){
    if( pSrc->a[i].fg.isRecursive ){
      iCurrent = pSrc->a[i].iCursor;
................................................................................
  sqlite3VdbeGoto(v, addrTop);
  sqlite3VdbeResolveLabel(v, addrBreak);

end_of_recursive_query:
  sqlite3ExprListDelete(pParse->db, p->pOrderBy);
  p->pOrderBy = pOrderBy;
  p->pLimit = pLimit;
  p->pOffset = pOffset;
  return;
}
#endif /* SQLITE_OMIT_CTE */

/* Forward references */
static int multiSelectOrderBy(
  Parse *pParse,        /* Parsing context */
................................................................................
  int nRow = 1;
  int rc = 0;
  assert( p->selFlags & SF_MultiValue );
  do{
    assert( p->selFlags & SF_Values );
    assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
    assert( p->pLimit==0 );
    assert( p->pOffset==0 );
    assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
    if( p->pPrior==0 ) break;
    assert( p->pPrior->pNext==p );
    p = p->pPrior;
    nRow++;
  }while(1);
  while( p ){
................................................................................
    case TK_ALL: {
      int addr = 0;
      int nLimit;
      assert( !pPrior->pLimit );
      pPrior->iLimit = p->iLimit;
      pPrior->iOffset = p->iOffset;
      pPrior->pLimit = p->pLimit;
      pPrior->pOffset = p->pOffset;
      explainSetInteger(iSub1, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, pPrior, &dest);
      p->pLimit = 0;
      p->pOffset = 0;
      if( rc ){
        goto multi_select_end;
      }
      p->pPrior = 0;
      p->iLimit = pPrior->iLimit;
      p->iOffset = pPrior->iOffset;
      if( p->iLimit ){
................................................................................
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &dest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
      p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
      if( pPrior->pLimit
       && sqlite3ExprIsInteger(pPrior->pLimit, &nLimit)
       && nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit) 
      ){
        p->nSelectRow = sqlite3LogEst((u64)nLimit);
      }
      if( addr ){
        sqlite3VdbeJumpHere(v, addr);
      }
................................................................................
      break;
    }
    case TK_EXCEPT:
    case TK_UNION: {
      int unionTab;    /* Cursor number of the temporary table holding result */
      u8 op = 0;       /* One of the SRT_ operations to apply to self */
      int priorOp;     /* The SRT_ operation to apply to prior selects */
      Expr *pLimit, *pOffset; /* Saved values of p->nLimit and p->nOffset */
      int addr;
      SelectDest uniondest;

      testcase( p->op==TK_EXCEPT );
      testcase( p->op==TK_UNION );
      priorOp = SRT_Union;
      if( dest.eDest==priorOp ){
        /* We can reuse a temporary table generated by a SELECT to our
        ** right.
        */
        assert( p->pLimit==0 );      /* Not allowed on leftward elements */
        assert( p->pOffset==0 );     /* Not allowed on leftward elements */
        unionTab = dest.iSDParm;
      }else{
        /* We will need to create our own temporary table to hold the
        ** intermediate results.
        */
        unionTab = pParse->nTab++;
        assert( p->pOrderBy==0 );
................................................................................
      }else{
        assert( p->op==TK_UNION );
        op = SRT_Union;
      }
      p->pPrior = 0;
      pLimit = p->pLimit;
      p->pLimit = 0;
      pOffset = p->pOffset;
      p->pOffset = 0;
      uniondest.eDest = op;
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &uniondest);
      testcase( rc!=SQLITE_OK );
      /* Query flattening in sqlite3Select() might refill p->pOrderBy.
      ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
      sqlite3ExprListDelete(db, p->pOrderBy);
................................................................................
      p->pPrior = pPrior;
      p->pOrderBy = 0;
      if( p->op==TK_UNION ){
        p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
      }
      sqlite3ExprDelete(db, p->pLimit);
      p->pLimit = pLimit;
      p->pOffset = pOffset;
      p->iLimit = 0;
      p->iOffset = 0;

      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */
      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
................................................................................
        sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
      }
      break;
    }
    default: assert( p->op==TK_INTERSECT ); {
      int tab1, tab2;
      int iCont, iBreak, iStart;
      Expr *pLimit, *pOffset;
      int addr;
      SelectDest intersectdest;
      int r1;

      /* INTERSECT is different from the others since it requires
      ** two temporary tables.  Hence it has its own case.  Begin
      ** by allocating the tables we will need.
................................................................................
      */
      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
      assert( p->addrOpenEphm[1] == -1 );
      p->addrOpenEphm[1] = addr;
      p->pPrior = 0;
      pLimit = p->pLimit;
      p->pLimit = 0;
      pOffset = p->pOffset;
      p->pOffset = 0;
      intersectdest.iSDParm = tab2;
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &intersectdest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
      if( p->nSelectRow>pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
      sqlite3ExprDelete(db, p->pLimit);
      p->pLimit = pLimit;
      p->pOffset = pOffset;

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
................................................................................
                                  regLimitA);
    sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);
  }else{
    regLimitA = regLimitB = 0;
  }
  sqlite3ExprDelete(db, p->pLimit);
  p->pLimit = 0;
  sqlite3ExprDelete(db, p->pOffset);
  p->pOffset = 0;

  regAddrA = ++pParse->nMem;
  regAddrB = ++pParse->nMem;
  regOutA = ++pParse->nMem;
  regOutB = ++pParse->nMem;
  sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
  sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
................................................................................
**  (18)  If the sub-query is a compound select, then all terms of the
**        ORDER BY clause of the parent must be simple references to 
**        columns of the sub-query.
**
**  (19)  If the subquery uses LIMIT then the outer query may not
**        have a WHERE clause.
**
**  (**)  Subsumed into (17d3).  Was: If the sub-query is a compound select,
**        then it must not use an ORDER BY clause - Ticket #3773.  Because
**        of (17d3), then only way to have a compound subquery is if it is
**        the only term in the FROM clause of the outer query.  But if the
**        only term in the FROM clause has an ORDER BY, then it will be
**        implemented as a co-routine and the flattener will never be called.
**
**  (21)  If the subquery uses LIMIT then the outer query may not be
**        DISTINCT.  (See ticket [752e1646fc]).
**
**  (22)  The subquery may not be a recursive CTE.
**
**  (**)  Subsumed into restriction (17d3).  Was: If the outer query is
................................................................................
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
  ** became arbitrary expressions, we were forced to add restrictions (13)
  ** and (14). */
  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
  if( pSub->pOffset ) return 0;                          /* Restriction (14) */
  if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
    return 0;                                            /* Restriction (15) */
  }
  if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
  if( pSub->selFlags & SF_Distinct ) return 0;           /* Restriction (4)  */
  if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){
     return 0;         /* Restrictions (8)(9) */
................................................................................

  /* Restriction (17): If the sub-query is a compound SELECT, then it must
  ** use only the UNION ALL operator. And none of the simple select queries
  ** that make up the compound SELECT are allowed to be aggregate or distinct
  ** queries.
  */
  if( pSub->pPrior ){



    if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){
      return 0; /* (17d1), (17d2), or (17d3) */
    }
    for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
      assert( pSub->pSrc!=0 );
................................................................................
  ** The only way that the recursive part of a CTE can contain a compound
  ** subquery is for the subquery to be one term of a join.  But if the
  ** subquery is a join, then the flattening has already been stopped by
  ** restriction (17d3)
  */
  assert( (p->selFlags & SF_Recursive)==0 || pSub->pPrior==0 );

  /* Ex-restriction (20):
  ** A compound subquery must be the only term in the FROM clause of the
  ** outer query by restriction (17d3).  But if that term also has an
  ** ORDER BY clause, then the subquery will be implemented by co-routine
  ** and so the flattener will never be invoked.  Hence, it is not possible
  ** for the subquery to be a compound and have an ORDER BY clause.
  */
  assert( pSub->pPrior==0 || pSub->pOrderBy==0 );

  /***** If we reach this point, flattening is permitted. *****/
  SELECTTRACE(1,pParse,p,("flatten %s.%p from term %d\n",
                   pSub->zSelName, pSub, iFrom));

  /* Authorize the subquery */
  pParse->zAuthContext = pSubitem->zName;
  TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
................................................................................
  **
  ** We call this the "compound-subquery flattening".
  */
  for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
    Select *pNew;
    ExprList *pOrderBy = p->pOrderBy;
    Expr *pLimit = p->pLimit;
    Expr *pOffset = p->pOffset;
    Select *pPrior = p->pPrior;
    p->pOrderBy = 0;
    p->pSrc = 0;
    p->pPrior = 0;
    p->pLimit = 0;
    p->pOffset = 0;
    pNew = sqlite3SelectDup(db, p, 0);
    sqlite3SelectSetName(pNew, pSub->zSelName);
    p->pOffset = pOffset;
    p->pLimit = pLimit;
    p->pOrderBy = pOrderBy;
    p->pSrc = pSrc;
    p->op = TK_ALL;
    if( pNew==0 ){
      p->pPrior = pPrior;
    }else{
................................................................................
    }
  }
  return nChng;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

/*
** Based on the contents of the AggInfo structure indicated by the first
** argument, this function checks if the following are true:
**
**    * the query contains just a single aggregate function,
**    * the aggregate function is either min() or max(), and
**    * the argument to the aggregate function is a column value.
**
** If all of the above are true, then WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX
** is returned as appropriate. Also, *ppMinMax is set to point to the 
** list of arguments passed to the aggregate before returning.
**
** Or, if the conditions above are not met, *ppMinMax is set to 0 and
** WHERE_ORDERBY_NORMAL is returned.
*/
static u8 minMaxQuery(AggInfo *pAggInfo, ExprList **ppMinMax){
  int eRet = WHERE_ORDERBY_NORMAL;          /* Return value */

  *ppMinMax = 0;
  if( pAggInfo->nFunc==1 ){
    Expr *pExpr = pAggInfo->aFunc[0].pExpr; /* Aggregate function */
    ExprList *pEList = pExpr->x.pList;      /* Arguments to agg function */

    assert( pExpr->op==TK_AGG_FUNCTION );
    if( pEList && pEList->nExpr==1 && pEList->a[0].pExpr->op==TK_AGG_COLUMN ){
      const char *zFunc = pExpr->u.zToken;
      if( sqlite3StrICmp(zFunc, "min")==0 ){
        eRet = WHERE_ORDERBY_MIN;
        *ppMinMax = pEList;
      }else if( sqlite3StrICmp(zFunc, "max")==0 ){
        eRet = WHERE_ORDERBY_MAX;
        *ppMinMax = pEList;
      }
    }
  }

  assert( *ppMinMax==0 || (*ppMinMax)->nExpr==1 );


  return eRet;
}

/*
** The select statement passed as the first argument is an aggregate query.
** The second argument is the associated aggregate-info object. This 
** function tests if the SELECT is of the form:
................................................................................
  p->pWith = 0;
  p->selFlags &= ~SF_Compound;
  assert( (p->selFlags & SF_Converted)==0 );
  p->selFlags |= SF_Converted;
  assert( pNew->pPrior!=0 );
  pNew->pPrior->pNext = pNew;
  pNew->pLimit = 0;
  pNew->pOffset = 0;
  return WRC_Continue;
}

/*
** Check to see if the FROM clause term pFrom has table-valued function
** arguments.  If it does, leave an error message in pParse and return
** non-zero, since pFrom is not allowed to be a table-valued function.
................................................................................
  int i, j, k;
  SrcList *pTabList;
  ExprList *pEList;
  struct SrcList_item *pFrom;
  sqlite3 *db = pParse->db;
  Expr *pE, *pRight, *pExpr;
  u16 selFlags = p->selFlags;


  p->selFlags |= SF_Expanded;
  if( db->mallocFailed  ){
    return WRC_Abort;
  }

  if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){
    return WRC_Prune;
  }
  pTabList = p->pSrc;
  pEList = p->pEList;
  if( OK_IF_ALWAYS_TRUE(p->pWith) ){
    sqlite3WithPush(pParse, p->pWith, 0);
  }
................................................................................
  */
  for(k=0; k<pEList->nExpr; k++){
    pE = pEList->a[k].pExpr;
    if( pE->op==TK_ASTERISK ) break;
    assert( pE->op!=TK_DOT || pE->pRight!=0 );
    assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
    if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;

  }
  if( k<pEList->nExpr ){
    /*
    ** If we get here it means the result set contains one or more "*"
    ** operators that need to be expanded.  Loop through each expression
    ** in the result set and expand them one by one.
    */
................................................................................
    ExprList *pNew = 0;
    int flags = pParse->db->flags;
    int longNames = (flags & SQLITE_FullColNames)!=0
                      && (flags & SQLITE_ShortColNames)==0;

    for(k=0; k<pEList->nExpr; k++){
      pE = a[k].pExpr;

      pRight = pE->pRight;
      assert( pE->op!=TK_DOT || pRight!=0 );
      if( pE->op!=TK_ASTERISK
       && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
      ){
        /* This particular expression does not need to be expanded.
        */
................................................................................
          }
        }
      }
    }
    sqlite3ExprListDelete(db, pEList);
    p->pEList = pNew;
  }
#if SQLITE_MAX_COLUMN
  if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
    sqlite3ErrorMsg(pParse, "too many columns in result set");
    return WRC_Abort;
  }
#endif



  return WRC_Continue;
}

/*
** No-op routine for the parse-tree walker.
**
** When this routine is the Walker.xExprCallback then expression trees
................................................................................
  Expr *pHaving;         /* The HAVING clause.  May be NULL */
  int rc = 1;            /* Value to return from this function */
  DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */
  SortCtx sSort;         /* Info on how to code the ORDER BY clause */
  AggInfo sAggInfo;      /* Information used by aggregate queries */
  int iEnd;              /* Address of the end of the query */
  sqlite3 *db;           /* The database connection */



#ifndef SQLITE_OMIT_EXPLAIN
  int iRestoreSelectId = pParse->iSelectId;
  pParse->iSelectId = pParse->iNextSelectId++;
#endif

  db = pParse->db;
................................................................................
    ** is not a join.  But if the outer query is not a join, then the subquery
    ** will be implemented as a co-routine and there is no advantage to
    ** flattening in that case.
    */
    if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
    assert( pSub->pGroupBy==0 );



    /* If the subquery contains an ORDER BY clause and if
    ** it will be implemented as a co-routine, then do not flatten.  This
    ** restriction allows SQL constructs like this:
    **
    **  SELECT expensive_function(x)
    **    FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
    **
    ** The expensive_function() is only computed on the 10 rows that
    ** are output, rather than every row of the table.






    */
    if( pSub->pOrderBy!=0
     && i==0

     && (pTabList->nSrc==1
         || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)
    ){
      continue;
    }

    if( flattenSubquery(pParse, p, i, isAgg) ){
................................................................................
        assert( pWhere==p->pWhere );
        havingToWhere(pParse, pGroupBy, pHaving, &p->pWhere);
        pWhere = p->pWhere;
      }
      sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
    }
    sAggInfo.nAccumulator = sAggInfo.nColumn;





    for(i=0; i<sAggInfo.nFunc; i++){
      assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) );
      sNC.ncFlags |= NC_InAggFunc;
      sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);
      sNC.ncFlags &= ~NC_InAggFunc;
    }
    sAggInfo.mxReg = pParse->nMem;
    if( db->mallocFailed ) goto select_end;



















    /* Processing for aggregates with GROUP BY is very different and
    ** much more complex than aggregates without a GROUP BY.
    */
    if( pGroupBy ){
      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
      int addr1;          /* A-vs-B comparision jump */
................................................................................
      */
      sqlite3VdbeResolveLabel(v, addrReset);
      resetAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp1(v, OP_Return, regReset);
     
    } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */
    else {
      ExprList *pDel = 0;
#ifndef SQLITE_OMIT_BTREECOUNT
      Table *pTab;
      if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){
        /* If isSimpleCount() returns a pointer to a Table structure, then
        ** the SQL statement is of the form:
        **
        **   SELECT count(*) FROM <tbl>
................................................................................
        }
        sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
        sqlite3VdbeAddOp1(v, OP_Close, iCsr);
        explainSimpleCount(pParse, pTab, pBest);
      }else
#endif /* SQLITE_OMIT_BTREECOUNT */
      {
        /* Check if the query is of one of the following forms:
        **
        **   SELECT min(x) FROM ...
        **   SELECT max(x) FROM ...
        **
        ** If it is, then ask the code in where.c to attempt to sort results
        ** as if there was an "ORDER ON x" or "ORDER ON x DESC" clause. 
        ** If where.c is able to produce results sorted in this order, then
        ** add vdbe code to break out of the processing loop after the 
        ** first iteration (since the first iteration of the loop is 
        ** guaranteed to operate on the row with the minimum or maximum 
        ** value of x, the only row required).
        **
        ** A special flag must be passed to sqlite3WhereBegin() to slightly
        ** modify behavior as follows:
        **
        **   + If the query is a "SELECT min(x)", then the loop coded by
        **     where.c should not iterate over any values with a NULL value
        **     for x.
        **
        **   + The optimizer code in where.c (the thing that decides which
        **     index or indices to use) should place a different priority on 
        **     satisfying the 'ORDER BY' clause than it does in other cases.
        **     Refer to code and comments in where.c for details.
        */
        ExprList *pMinMax = 0;
        u8 flag = WHERE_ORDERBY_NORMAL;
        
        assert( p->pGroupBy==0 );
        assert( flag==0 );
        if( p->pHaving==0 ){
          flag = minMaxQuery(&sAggInfo, &pMinMax);
        }
        assert( flag==0 || (pMinMax!=0 && pMinMax->nExpr==1) );

        if( flag ){
          pMinMax = sqlite3ExprListDup(db, pMinMax, 0);
          pDel = pMinMax;
          assert( db->mallocFailed || pMinMax!=0 );
          if( !db->mallocFailed ){
            pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0;
            pMinMax->a[0].pExpr->op = TK_COLUMN;
          }
        }
  
        /* This case runs if the aggregate has no GROUP BY clause.  The
        ** processing is much simpler since there is only a single row
        ** of output.
        */

        resetAccumulator(pParse, &sAggInfo);









        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMax, 0,flag,0);

        if( pWInfo==0 ){
          sqlite3ExprListDelete(db, pDel);
          goto select_end;
        }
        updateAccumulator(pParse, &sAggInfo);
        assert( pMinMax==0 || pMinMax->nExpr==1 );
        if( sqlite3WhereIsOrdered(pWInfo)>0 ){
          sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));
          VdbeComment((v, "%s() by index",
                (flag==WHERE_ORDERBY_MIN?"min":"max")));
        }
        sqlite3WhereEnd(pWInfo);
        finalizeAggFunctions(pParse, &sAggInfo);
      }

      sSort.pOrderBy = 0;
      sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
      selectInnerLoop(pParse, p, -1, 0, 0, 
                      pDest, addrEnd, addrEnd);
      sqlite3ExprListDelete(db, pDel);
    }
    sqlite3VdbeResolveLabel(v, addrEnd);
    
  } /* endif aggregate query */

  if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
    explainTempTable(pParse, "DISTINCT");
................................................................................
  rc = (pParse->nErr>0);

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  explainSetInteger(pParse->iSelectId, iRestoreSelectId);

  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
#if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p,("end processing\n"));
  pParse->nSelectIndent--;
#endif
  return rc;
}

    sqlite3ExprListDelete(db, p->pEList);
    sqlite3SrcListDelete(db, p->pSrc);
    sqlite3ExprDelete(db, p->pWhere);
    sqlite3ExprListDelete(db, p->pGroupBy);
    sqlite3ExprDelete(db, p->pHaving);
    sqlite3ExprListDelete(db, p->pOrderBy);
    sqlite3ExprDelete(db, p->pLimit);

    if( OK_IF_ALWAYS_TRUE(p->pWith) ) sqlite3WithDelete(db, p->pWith);
    if( bFree ) sqlite3DbFreeNN(db, p);
    p = pPrior;
    bFree = 1;
  }
}

................................................................................
  ExprList *pEList,     /* which columns to include in the result */
  SrcList *pSrc,        /* the FROM clause -- which tables to scan */
  Expr *pWhere,         /* the WHERE clause */
  ExprList *pGroupBy,   /* the GROUP BY clause */
  Expr *pHaving,        /* the HAVING clause */
  ExprList *pOrderBy,   /* the ORDER BY clause */
  u32 selFlags,         /* Flag parameters, such as SF_Distinct */
  Expr *pLimit          /* LIMIT value.  NULL means not used */

){
  Select *pNew;
  Select standin;
  pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
  if( pNew==0 ){
    assert( pParse->db->mallocFailed );
    pNew = &standin;
................................................................................
  pNew->pWhere = pWhere;
  pNew->pGroupBy = pGroupBy;
  pNew->pHaving = pHaving;
  pNew->pOrderBy = pOrderBy;
  pNew->pPrior = 0;
  pNew->pNext = 0;
  pNew->pLimit = pLimit;

  pNew->pWith = 0;


  if( pParse->db->mallocFailed ) {
    clearSelect(pParse->db, pNew, pNew!=&standin);
    pNew = 0;
  }else{
    assert( pNew->pSrc!=0 || pParse->nErr>0 );
  }
  assert( pNew!=&standin );
................................................................................
  Hash ht;                    /* Hash table of column names */

  sqlite3HashInit(&ht);
  if( pEList ){
    nCol = pEList->nExpr;
    aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
    testcase( aCol==0 );
    if( nCol>32767 ) nCol = 32767;
  }else{
    nCol = 0;
    aCol = 0;
  }
  assert( nCol==(i16)nCol );
  *pnCol = nCol;
  *paCol = aCol;
................................................................................
  }
  return sqlite3VdbeCreate(pParse);
}


/*
** Compute the iLimit and iOffset fields of the SELECT based on the
** pLimit expressions.  pLimit->pLeft and pLimit->pRight hold the expressions
** that appear in the original SQL statement after the LIMIT and OFFSET
** keywords.  Or NULL if those keywords are omitted. iLimit and iOffset 
** are the integer memory register numbers for counters used to compute 
** the limit and offset.  If there is no limit and/or offset, then 
** iLimit and iOffset are negative.
**
** This routine changes the values of iLimit and iOffset only if
** a limit or offset is defined by pLimit->pLeft and pLimit->pRight.  iLimit
** and iOffset should have been preset to appropriate default values (zero)
** prior to calling this routine.
**
** The iOffset register (if it exists) is initialized to the value
** of the OFFSET.  The iLimit register is initialized to LIMIT.  Register
** iOffset+1 is initialized to LIMIT+OFFSET.
**
** Only if pLimit->pLeft!=0 do the limit registers get
** redefined.  The UNION ALL operator uses this property to force
** the reuse of the same limit and offset registers across multiple
** SELECT statements.
*/
static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
  Vdbe *v = 0;
  int iLimit = 0;
  int iOffset;
  int n;
  Expr *pLimit = p->pLimit;

  if( p->iLimit ) return;

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** controversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
  */
  sqlite3ExprCacheClear(pParse);
  if( pLimit ){
    assert( pLimit->op==TK_LIMIT );
    assert( pLimit->pLeft!=0 );
    p->iLimit = iLimit = ++pParse->nMem;
    v = sqlite3GetVdbe(pParse);
    assert( v!=0 );
    if( sqlite3ExprIsInteger(pLimit->pLeft, &n) ){
      sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
      VdbeComment((v, "LIMIT counter"));
      if( n==0 ){
        sqlite3VdbeGoto(v, iBreak);
      }else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){
        p->nSelectRow = sqlite3LogEst((u64)n);
        p->selFlags |= SF_FixedLimit;
      }
    }else{
      sqlite3ExprCode(pParse, pLimit->pLeft, iLimit);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
      VdbeComment((v, "LIMIT counter"));
      sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
    }
    if( pLimit->pRight ){
      p->iOffset = iOffset = ++pParse->nMem;
      pParse->nMem++;   /* Allocate an extra register for limit+offset */
      sqlite3ExprCode(pParse, pLimit->pRight, iOffset);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
      VdbeComment((v, "OFFSET counter"));
      sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);
      VdbeComment((v, "LIMIT+OFFSET"));
    }
  }
}
................................................................................
  int iQueue;                   /* The Queue table */
  int iDistinct = 0;            /* To ensure unique results if UNION */
  int eDest = SRT_Fifo;         /* How to write to Queue */
  SelectDest destQueue;         /* SelectDest targetting the Queue table */
  int i;                        /* Loop counter */
  int rc;                       /* Result code */
  ExprList *pOrderBy;           /* The ORDER BY clause */
  Expr *pLimit;                 /* Saved LIMIT and OFFSET */
  int regLimit, regOffset;      /* Registers used by LIMIT and OFFSET */

  /* Obtain authorization to do a recursive query */
  if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;

  /* Process the LIMIT and OFFSET clauses, if they exist */
  addrBreak = sqlite3VdbeMakeLabel(v);
  p->nSelectRow = 320;  /* 4 billion rows */
  computeLimitRegisters(pParse, p, addrBreak);
  pLimit = p->pLimit;

  regLimit = p->iLimit;
  regOffset = p->iOffset;
  p->pLimit = 0;
  p->iLimit = p->iOffset = 0;
  pOrderBy = p->pOrderBy;

  /* Locate the cursor number of the Current table */
  for(i=0; ALWAYS(i<pSrc->nSrc); i++){
    if( pSrc->a[i].fg.isRecursive ){
      iCurrent = pSrc->a[i].iCursor;
................................................................................
  sqlite3VdbeGoto(v, addrTop);
  sqlite3VdbeResolveLabel(v, addrBreak);

end_of_recursive_query:
  sqlite3ExprListDelete(pParse->db, p->pOrderBy);
  p->pOrderBy = pOrderBy;
  p->pLimit = pLimit;

  return;
}
#endif /* SQLITE_OMIT_CTE */

/* Forward references */
static int multiSelectOrderBy(
  Parse *pParse,        /* Parsing context */
................................................................................
  int nRow = 1;
  int rc = 0;
  assert( p->selFlags & SF_MultiValue );
  do{
    assert( p->selFlags & SF_Values );
    assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
    assert( p->pLimit==0 );

    assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
    if( p->pPrior==0 ) break;
    assert( p->pPrior->pNext==p );
    p = p->pPrior;
    nRow++;
  }while(1);
  while( p ){
................................................................................
    case TK_ALL: {
      int addr = 0;
      int nLimit;
      assert( !pPrior->pLimit );
      pPrior->iLimit = p->iLimit;
      pPrior->iOffset = p->iOffset;
      pPrior->pLimit = p->pLimit;

      explainSetInteger(iSub1, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, pPrior, &dest);
      p->pLimit = 0;

      if( rc ){
        goto multi_select_end;
      }
      p->pPrior = 0;
      p->iLimit = pPrior->iLimit;
      p->iOffset = pPrior->iOffset;
      if( p->iLimit ){
................................................................................
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &dest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
      p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
      if( pPrior->pLimit
       && sqlite3ExprIsInteger(pPrior->pLimit->pLeft, &nLimit)
       && nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit) 
      ){
        p->nSelectRow = sqlite3LogEst((u64)nLimit);
      }
      if( addr ){
        sqlite3VdbeJumpHere(v, addr);
      }
................................................................................
      break;
    }
    case TK_EXCEPT:
    case TK_UNION: {
      int unionTab;    /* Cursor number of the temporary table holding result */
      u8 op = 0;       /* One of the SRT_ operations to apply to self */
      int priorOp;     /* The SRT_ operation to apply to prior selects */
      Expr *pLimit;    /* Saved values of p->nLimit  */
      int addr;
      SelectDest uniondest;

      testcase( p->op==TK_EXCEPT );
      testcase( p->op==TK_UNION );
      priorOp = SRT_Union;
      if( dest.eDest==priorOp ){
        /* We can reuse a temporary table generated by a SELECT to our
        ** right.
        */
        assert( p->pLimit==0 );      /* Not allowed on leftward elements */

        unionTab = dest.iSDParm;
      }else{
        /* We will need to create our own temporary table to hold the
        ** intermediate results.
        */
        unionTab = pParse->nTab++;
        assert( p->pOrderBy==0 );
................................................................................
      }else{
        assert( p->op==TK_UNION );
        op = SRT_Union;
      }
      p->pPrior = 0;
      pLimit = p->pLimit;
      p->pLimit = 0;


      uniondest.eDest = op;
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &uniondest);
      testcase( rc!=SQLITE_OK );
      /* Query flattening in sqlite3Select() might refill p->pOrderBy.
      ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
      sqlite3ExprListDelete(db, p->pOrderBy);
................................................................................
      p->pPrior = pPrior;
      p->pOrderBy = 0;
      if( p->op==TK_UNION ){
        p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
      }
      sqlite3ExprDelete(db, p->pLimit);
      p->pLimit = pLimit;

      p->iLimit = 0;
      p->iOffset = 0;

      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */
      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
................................................................................
        sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
      }
      break;
    }
    default: assert( p->op==TK_INTERSECT ); {
      int tab1, tab2;
      int iCont, iBreak, iStart;
      Expr *pLimit;
      int addr;
      SelectDest intersectdest;
      int r1;

      /* INTERSECT is different from the others since it requires
      ** two temporary tables.  Hence it has its own case.  Begin
      ** by allocating the tables we will need.
................................................................................
      */
      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
      assert( p->addrOpenEphm[1] == -1 );
      p->addrOpenEphm[1] = addr;
      p->pPrior = 0;
      pLimit = p->pLimit;
      p->pLimit = 0;


      intersectdest.iSDParm = tab2;
      explainSetInteger(iSub2, pParse->iNextSelectId);
      rc = sqlite3Select(pParse, p, &intersectdest);
      testcase( rc!=SQLITE_OK );
      pDelete = p->pPrior;
      p->pPrior = pPrior;
      if( p->nSelectRow>pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
      sqlite3ExprDelete(db, p->pLimit);
      p->pLimit = pLimit;


      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
................................................................................
                                  regLimitA);
    sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);
  }else{
    regLimitA = regLimitB = 0;
  }
  sqlite3ExprDelete(db, p->pLimit);
  p->pLimit = 0;



  regAddrA = ++pParse->nMem;
  regAddrB = ++pParse->nMem;
  regOutA = ++pParse->nMem;
  regOutB = ++pParse->nMem;
  sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
  sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
................................................................................
**  (18)  If the sub-query is a compound select, then all terms of the
**        ORDER BY clause of the parent must be simple references to 
**        columns of the sub-query.
**
**  (19)  If the subquery uses LIMIT then the outer query may not
**        have a WHERE clause.
**
**  (20)  If the sub-query is a compound select, then it must not use
**        an ORDER BY clause.  Ticket #3773.  We could relax this constraint
**        somewhat by saying that the terms of the ORDER BY clause must
**        appear as unmodified result columns in the outer query.  But we
**        have other optimizations in mind to deal with that case.

**
**  (21)  If the subquery uses LIMIT then the outer query may not be
**        DISTINCT.  (See ticket [752e1646fc]).
**
**  (22)  The subquery may not be a recursive CTE.
**
**  (**)  Subsumed into restriction (17d3).  Was: If the outer query is
................................................................................
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
  ** became arbitrary expressions, we were forced to add restrictions (13)
  ** and (14). */
  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
  if( pSub->pLimit && pSub->pLimit->pRight ) return 0;   /* Restriction (14) */
  if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
    return 0;                                            /* Restriction (15) */
  }
  if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
  if( pSub->selFlags & SF_Distinct ) return 0;           /* Restriction (4)  */
  if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){
     return 0;         /* Restrictions (8)(9) */
................................................................................

  /* Restriction (17): If the sub-query is a compound SELECT, then it must
  ** use only the UNION ALL operator. And none of the simple select queries
  ** that make up the compound SELECT are allowed to be aggregate or distinct
  ** queries.
  */
  if( pSub->pPrior ){
    if( pSub->pOrderBy ){
      return 0;  /* Restriction (20) */
    }
    if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){
      return 0; /* (17d1), (17d2), or (17d3) */
    }
    for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
      testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
      assert( pSub->pSrc!=0 );
................................................................................
  ** The only way that the recursive part of a CTE can contain a compound
  ** subquery is for the subquery to be one term of a join.  But if the
  ** subquery is a join, then the flattening has already been stopped by
  ** restriction (17d3)
  */
  assert( (p->selFlags & SF_Recursive)==0 || pSub->pPrior==0 );










  /***** If we reach this point, flattening is permitted. *****/
  SELECTTRACE(1,pParse,p,("flatten %s.%p from term %d\n",
                   pSub->zSelName, pSub, iFrom));

  /* Authorize the subquery */
  pParse->zAuthContext = pSubitem->zName;
  TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
................................................................................
  **
  ** We call this the "compound-subquery flattening".
  */
  for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
    Select *pNew;
    ExprList *pOrderBy = p->pOrderBy;
    Expr *pLimit = p->pLimit;

    Select *pPrior = p->pPrior;
    p->pOrderBy = 0;
    p->pSrc = 0;
    p->pPrior = 0;
    p->pLimit = 0;

    pNew = sqlite3SelectDup(db, p, 0);
    sqlite3SelectSetName(pNew, pSub->zSelName);

    p->pLimit = pLimit;
    p->pOrderBy = pOrderBy;
    p->pSrc = pSrc;
    p->op = TK_ALL;
    if( pNew==0 ){
      p->pPrior = pPrior;
    }else{
................................................................................
    }
  }
  return nChng;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

/*
** The pFunc is the only aggregate function in the query.  Check to see
** if the query is a candidate for the min/max optimization. 
**
** If the query is a candidate for the min/max optimization, then set
** *ppMinMax to be an ORDER BY clause to be used for the optimization
** and return either WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX depending on
** whether pFunc is a min() or max() function.
**
** If the query is not a candidate for the min/max optimization, return
** WHERE_ORDERBY_NORMAL (which must be zero).
**
** This routine must be called after aggregate functions have been
** located but before their arguments have been subjected to aggregate
** analysis.
*/
static u8 minMaxQuery(sqlite3 *db, Expr *pFunc, ExprList **ppMinMax){
  int eRet = WHERE_ORDERBY_NORMAL;      /* Return value */
  ExprList *pEList = pFunc->x.pList;    /* Arguments to agg function */
  const char *zFunc;                    /* Name of aggregate function pFunc */
  ExprList *pOrderBy;
  u8 sortOrder;

  assert( *ppMinMax==0 );
  assert( pFunc->op==TK_AGG_FUNCTION );
  if( pEList==0 || pEList->nExpr!=1 ) return eRet;
  zFunc = pFunc->u.zToken;
  if( sqlite3StrICmp(zFunc, "min")==0 ){
    eRet = WHERE_ORDERBY_MIN;
    sortOrder = SQLITE_SO_ASC;
  }else if( sqlite3StrICmp(zFunc, "max")==0 ){
    eRet = WHERE_ORDERBY_MAX;
    sortOrder = SQLITE_SO_DESC;
  }else{
    return eRet;
  }
  *ppMinMax = pOrderBy = sqlite3ExprListDup(db, pEList, 0);
  assert( pOrderBy!=0 || db->mallocFailed );
  if( pOrderBy ) pOrderBy->a[0].sortOrder = sortOrder;
  return eRet;
}

/*
** The select statement passed as the first argument is an aggregate query.
** The second argument is the associated aggregate-info object. This 
** function tests if the SELECT is of the form:
................................................................................
  p->pWith = 0;
  p->selFlags &= ~SF_Compound;
  assert( (p->selFlags & SF_Converted)==0 );
  p->selFlags |= SF_Converted;
  assert( pNew->pPrior!=0 );
  pNew->pPrior->pNext = pNew;
  pNew->pLimit = 0;

  return WRC_Continue;
}

/*
** Check to see if the FROM clause term pFrom has table-valued function
** arguments.  If it does, leave an error message in pParse and return
** non-zero, since pFrom is not allowed to be a table-valued function.
................................................................................
  int i, j, k;
  SrcList *pTabList;
  ExprList *pEList;
  struct SrcList_item *pFrom;
  sqlite3 *db = pParse->db;
  Expr *pE, *pRight, *pExpr;
  u16 selFlags = p->selFlags;
  u32 elistFlags = 0;

  p->selFlags |= SF_Expanded;
  if( db->mallocFailed  ){
    return WRC_Abort;
  }
  assert( p->pSrc!=0 );
  if( (selFlags & SF_Expanded)!=0 ){
    return WRC_Prune;
  }
  pTabList = p->pSrc;
  pEList = p->pEList;
  if( OK_IF_ALWAYS_TRUE(p->pWith) ){
    sqlite3WithPush(pParse, p->pWith, 0);
  }
................................................................................
  */
  for(k=0; k<pEList->nExpr; k++){
    pE = pEList->a[k].pExpr;
    if( pE->op==TK_ASTERISK ) break;
    assert( pE->op!=TK_DOT || pE->pRight!=0 );
    assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
    if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;
    elistFlags |= pE->flags;
  }
  if( k<pEList->nExpr ){
    /*
    ** If we get here it means the result set contains one or more "*"
    ** operators that need to be expanded.  Loop through each expression
    ** in the result set and expand them one by one.
    */
................................................................................
    ExprList *pNew = 0;
    int flags = pParse->db->flags;
    int longNames = (flags & SQLITE_FullColNames)!=0
                      && (flags & SQLITE_ShortColNames)==0;

    for(k=0; k<pEList->nExpr; k++){
      pE = a[k].pExpr;
      elistFlags |= pE->flags;
      pRight = pE->pRight;
      assert( pE->op!=TK_DOT || pRight!=0 );
      if( pE->op!=TK_ASTERISK
       && (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
      ){
        /* This particular expression does not need to be expanded.
        */
................................................................................
          }
        }
      }
    }
    sqlite3ExprListDelete(db, pEList);
    p->pEList = pNew;
  }
  if( p->pEList ){
    if( p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
      sqlite3ErrorMsg(pParse, "too many columns in result set");
      return WRC_Abort;
    }
    if( (elistFlags & (EP_HasFunc|EP_Subquery))!=0 ){
      p->selFlags |= SF_ComplexResult;
    }
  }
  return WRC_Continue;
}

/*
** No-op routine for the parse-tree walker.
**
** When this routine is the Walker.xExprCallback then expression trees
................................................................................
  Expr *pHaving;         /* The HAVING clause.  May be NULL */
  int rc = 1;            /* Value to return from this function */
  DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */
  SortCtx sSort;         /* Info on how to code the ORDER BY clause */
  AggInfo sAggInfo;      /* Information used by aggregate queries */
  int iEnd;              /* Address of the end of the query */
  sqlite3 *db;           /* The database connection */
  ExprList *pMinMaxOrderBy = 0;  /* Added ORDER BY for min/max queries */
  u8 minMaxFlag;                 /* Flag for min/max queries */

#ifndef SQLITE_OMIT_EXPLAIN
  int iRestoreSelectId = pParse->iSelectId;
  pParse->iSelectId = pParse->iNextSelectId++;
#endif

  db = pParse->db;
................................................................................
    ** is not a join.  But if the outer query is not a join, then the subquery
    ** will be implemented as a co-routine and there is no advantage to
    ** flattening in that case.
    */
    if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
    assert( pSub->pGroupBy==0 );

    /* If the outer query contains a "complex" result set (that is,
    ** if the result set of the outer query uses functions or subqueries)
    ** and if the subquery contains an ORDER BY clause and if
    ** it will be implemented as a co-routine, then do not flatten.  This
    ** restriction allows SQL constructs like this:
    **
    **  SELECT expensive_function(x)
    **    FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
    **
    ** The expensive_function() is only computed on the 10 rows that
    ** are output, rather than every row of the table.
    **
    ** The requirement that the outer query have a complex result set
    ** means that flattening does occur on simpler SQL constraints without
    ** the expensive_function() like:
    **
    **  SELECT x FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
    */
    if( pSub->pOrderBy!=0
     && i==0
     && (p->selFlags & SF_ComplexResult)!=0
     && (pTabList->nSrc==1
         || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)
    ){
      continue;
    }

    if( flattenSubquery(pParse, p, i, isAgg) ){
................................................................................
        assert( pWhere==p->pWhere );
        havingToWhere(pParse, pGroupBy, pHaving, &p->pWhere);
        pWhere = p->pWhere;
      }
      sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
    }
    sAggInfo.nAccumulator = sAggInfo.nColumn;
    if( p->pGroupBy==0 && p->pHaving==0 && sAggInfo.nFunc==1 ){
      minMaxFlag = minMaxQuery(db, sAggInfo.aFunc[0].pExpr, &pMinMaxOrderBy);
    }else{
      minMaxFlag = WHERE_ORDERBY_NORMAL;
    }
    for(i=0; i<sAggInfo.nFunc; i++){
      assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) );
      sNC.ncFlags |= NC_InAggFunc;
      sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList);
      sNC.ncFlags &= ~NC_InAggFunc;
    }
    sAggInfo.mxReg = pParse->nMem;
    if( db->mallocFailed ) goto select_end;
#if SELECTTRACE_ENABLED
    if( sqlite3SelectTrace & 0x400 ){
      int ii;
      SELECTTRACE(0x400,pParse,p,("After aggregate analysis:\n"));
      sqlite3TreeViewSelect(0, p, 0);
      for(ii=0; ii<sAggInfo.nColumn; ii++){
        sqlite3DebugPrintf("agg-column[%d] iMem=%d\n",
            ii, sAggInfo.aCol[ii].iMem);
        sqlite3TreeViewExpr(0, sAggInfo.aCol[ii].pExpr, 0);
      }
      for(ii=0; ii<sAggInfo.nFunc; ii++){
        sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",
            ii, sAggInfo.aFunc[ii].iMem);
        sqlite3TreeViewExpr(0, sAggInfo.aFunc[ii].pExpr, 0);
      }
    }
#endif


    /* Processing for aggregates with GROUP BY is very different and
    ** much more complex than aggregates without a GROUP BY.
    */
    if( pGroupBy ){
      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
      int addr1;          /* A-vs-B comparision jump */
................................................................................
      */
      sqlite3VdbeResolveLabel(v, addrReset);
      resetAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp1(v, OP_Return, regReset);
     
    } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */
    else {

#ifndef SQLITE_OMIT_BTREECOUNT
      Table *pTab;
      if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){
        /* If isSimpleCount() returns a pointer to a Table structure, then
        ** the SQL statement is of the form:
        **
        **   SELECT count(*) FROM <tbl>
................................................................................
        }
        sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem);
        sqlite3VdbeAddOp1(v, OP_Close, iCsr);
        explainSimpleCount(pParse, pTab, pBest);
      }else
#endif /* SQLITE_OMIT_BTREECOUNT */
      {













































        /* This case runs if the aggregate has no GROUP BY clause.  The
        ** processing is much simpler since there is only a single row
        ** of output.
        */
        assert( p->pGroupBy==0 );
        resetAccumulator(pParse, &sAggInfo);

        /* If this query is a candidate for the min/max optimization, then
        ** minMaxFlag will have been previously set to either
        ** WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX and pMinMaxOrderBy will
        ** be an appropriate ORDER BY expression for the optimization.
        */
        assert( minMaxFlag==WHERE_ORDERBY_NORMAL || pMinMaxOrderBy!=0 );
        assert( pMinMaxOrderBy==0 || pMinMaxOrderBy->nExpr==1 );

        pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
                                   0, minMaxFlag, 0);
        if( pWInfo==0 ){

          goto select_end;
        }
        updateAccumulator(pParse, &sAggInfo);

        if( sqlite3WhereIsOrdered(pWInfo)>0 ){
          sqlite3VdbeGoto(v, sqlite3WhereBreakLabel(pWInfo));
          VdbeComment((v, "%s() by index",
                (minMaxFlag==WHERE_ORDERBY_MIN?"min":"max")));
        }
        sqlite3WhereEnd(pWInfo);
        finalizeAggFunctions(pParse, &sAggInfo);
      }

      sSort.pOrderBy = 0;
      sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
      selectInnerLoop(pParse, p, -1, 0, 0, 
                      pDest, addrEnd, addrEnd);

    }
    sqlite3VdbeResolveLabel(v, addrEnd);
    
  } /* endif aggregate query */

  if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
    explainTempTable(pParse, "DISTINCT");
................................................................................
  rc = (pParse->nErr>0);

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  explainSetInteger(pParse->iSelectId, iRestoreSelectId);
  sqlite3ExprListDelete(db, pMinMaxOrderBy);
  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
#if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p,("end processing\n"));
  pParse->nSelectIndent--;
#endif
  return rc;
}

    }
  }
  if( bSep ){
    utf8_printf(p->out, "%s", p->colSeparator);
  }
}

#ifdef SIGINT
/*
** This routine runs when the user presses Ctrl-C
*/
static void interrupt_handler(int NotUsed){
  UNUSED_PARAMETER(NotUsed);
  seenInterrupt++;
  if( seenInterrupt>2 ) exit(1);
  if( globalDb ) sqlite3_interrupt(globalDb);
}














#endif

#ifndef SQLITE_OMIT_AUTHORIZATION
/*
** When the ".auth ON" is set, the following authorizer callback is
** invoked.  It always returns SQLITE_OK.
*/
................................................................................
  Argv0 = argv[0];

  /* Make sure we have a valid signal handler early, before anything
  ** else is done.
  */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);


#endif

#ifdef SQLITE_SHELL_DBNAME_PROC
  {
    /* If the SQLITE_SHELL_DBNAME_PROC macro is defined, then it is the name
    ** of a C-function that will provide the name of the database file.  Use
    ** this compile-time option to embed this shell program in larger

    }
  }
  if( bSep ){
    utf8_printf(p->out, "%s", p->colSeparator);
  }
}


/*
** This routine runs when the user presses Ctrl-C
*/
static void interrupt_handler(int NotUsed){
  UNUSED_PARAMETER(NotUsed);
  seenInterrupt++;
  if( seenInterrupt>2 ) exit(1);
  if( globalDb ) sqlite3_interrupt(globalDb);
}

#if (defined(_WIN32) || defined(WIN32)) && !defined(_WIN32_WCE)
/*
** This routine runs for console events (e.g. Ctrl-C) on Win32
*/
static BOOL WINAPI ConsoleCtrlHandler(
  DWORD dwCtrlType /* One of the CTRL_*_EVENT constants */
){
  if( dwCtrlType==CTRL_C_EVENT ){
    interrupt_handler(0);
    return TRUE;
  }
  return FALSE;
}
#endif

#ifndef SQLITE_OMIT_AUTHORIZATION
/*
** When the ".auth ON" is set, the following authorizer callback is
** invoked.  It always returns SQLITE_OK.
*/
................................................................................
  Argv0 = argv[0];

  /* Make sure we have a valid signal handler early, before anything
  ** else is done.
  */
#ifdef SIGINT
  signal(SIGINT, interrupt_handler);
#elif (defined(_WIN32) || defined(WIN32)) && !defined(_WIN32_WCE)
  SetConsoleCtrlHandler(ConsoleCtrlHandler, TRUE);
#endif

#ifdef SQLITE_SHELL_DBNAME_PROC
  {
    /* If the SQLITE_SHELL_DBNAME_PROC macro is defined, then it is the name
    ** of a C-function that will provide the name of the database file.  Use
    ** this compile-time option to embed this shell program in larger

#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))

#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))

#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
................................................................................
** CAPI3REF: OS Interface Object
**
** An instance of the sqlite3_vfs object defines the interface between
** the SQLite core and the underlying operating system.  The "vfs"
** in the name of the object stands for "virtual file system".  See
** the [VFS | VFS documentation] for further information.
**
** The value of the iVersion field is initially 1 but may be larger in






** future versions of SQLite.  Additional fields may be appended to this
** object when the iVersion value is increased.  Note that the structure
** of the sqlite3_vfs object changes in the transaction between

** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
** modified.
**
** The szOsFile field is the size of the subclassed [sqlite3_file]
** structure used by this VFS.  mxPathname is the maximum length of
** a pathname in this VFS.
**
** Registered sqlite3_vfs objects are kept on a linked list formed by
** the pNext pointer.  The [sqlite3_vfs_register()]

#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
#define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
#define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
#define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
#define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
#define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
#define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8))
#define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
#define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
#define SQLITE_READONLY_CANTINIT       (SQLITE_READONLY | (5<<8))
#define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
#define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
#define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
#define SQLITE_CONSTRAINT_FOREIGNKEY   (SQLITE_CONSTRAINT | (3<<8))
#define SQLITE_CONSTRAINT_FUNCTION     (SQLITE_CONSTRAINT | (4<<8))
#define SQLITE_CONSTRAINT_NOTNULL      (SQLITE_CONSTRAINT | (5<<8))
#define SQLITE_CONSTRAINT_PRIMARYKEY   (SQLITE_CONSTRAINT | (6<<8))
................................................................................
** CAPI3REF: OS Interface Object
**
** An instance of the sqlite3_vfs object defines the interface between
** the SQLite core and the underlying operating system.  The "vfs"
** in the name of the object stands for "virtual file system".  See
** the [VFS | VFS documentation] for further information.
**
** The VFS interface is sometimes extended by adding new methods onto
** the end.  Each time such an extension occurs, the iVersion field
** is incremented.  The iVersion value started out as 1 in
** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6].  Additional fields
** may be appended to the sqlite3_vfs object and the iVersion value
** may increase again in future versions of SQLite.
** Note that the structure
** of the sqlite3_vfs object changes in the transition from
** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
** and yet the iVersion field was not modified.

**
** The szOsFile field is the size of the subclassed [sqlite3_file]
** structure used by this VFS.  mxPathname is the maximum length of
** a pathname in this VFS.
**
** Registered sqlite3_vfs objects are kept on a linked list formed by
** the pNext pointer.  The [sqlite3_vfs_register()]

};

/*
** The following are the meanings of bits in the Expr.flags field.
*/
#define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */
#define EP_Agg       0x000002 /* Contains one or more aggregate functions */
                  /* 0x000004 // available for use */
                  /* 0x000008 // available for use */
#define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
#define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
#define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
#define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */
#define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */
................................................................................
#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
#define EP_Alias     0x400000 /* Is an alias for a result set column */
#define EP_Leaf      0x800000 /* Expr.pLeft, .pRight, .u.pSelect all NULL */

/*
** Combinations of two or more EP_* flags

*/
#define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */

/*
** These macros can be used to test, set, or clear bits in the
** Expr.flags field.
*/
#define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)
#define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))
................................................................................
#define NC_PartIdx   0x0002  /* True if resolving a partial index WHERE */
#define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
#define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
#define NC_HasAgg    0x0010  /* One or more aggregate functions seen */
#define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */
#define NC_VarSelect 0x0040  /* A correlated subquery has been seen */
#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */


/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
** If there is a LIMIT clause, the parser sets nLimit to the value of the
................................................................................
  Expr *pWhere;          /* The WHERE clause */
  ExprList *pGroupBy;    /* The GROUP BY clause */
  Expr *pHaving;         /* The HAVING clause */
  ExprList *pOrderBy;    /* The ORDER BY clause */
  Select *pPrior;        /* Prior select in a compound select statement */
  Select *pNext;         /* Next select to the left in a compound */
  Expr *pLimit;          /* LIMIT expression. NULL means not used. */
  Expr *pOffset;         /* OFFSET expression. NULL means not used. */
  With *pWith;           /* WITH clause attached to this select. Or NULL. */
};

/*
** Allowed values for Select.selFlags.  The "SF" prefix stands for
** "Select Flag".
**
................................................................................
#define SF_NestedFrom     0x00800  /* Part of a parenthesized FROM clause */
#define SF_MinMaxAgg      0x01000  /* Aggregate containing min() or max() */
#define SF_Recursive      0x02000  /* The recursive part of a recursive CTE */
#define SF_FixedLimit     0x04000  /* nSelectRow set by a constant LIMIT */
#define SF_MaybeConvert   0x08000  /* Need convertCompoundSelectToSubquery() */
#define SF_Converted      0x10000  /* By convertCompoundSelectToSubquery() */
#define SF_IncludeHidden  0x20000  /* Include hidden columns in output */



/*
** The results of a SELECT can be distributed in several ways, as defined
** by one of the following macros.  The "SRT" prefix means "SELECT Result
** Type".
**
................................................................................
void sqlite3SrcListDelete(sqlite3*, SrcList*);
Index *sqlite3AllocateIndexObject(sqlite3*,i16,int,char**);
void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                          Expr*, int, int, u8);
void sqlite3DropIndex(Parse*, SrcList*, int);
int sqlite3Select(Parse*, Select*, SelectDest*);
Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,u32,Expr*,Expr*);
void sqlite3SelectDelete(sqlite3*, Select*);
Table *sqlite3SrcListLookup(Parse*, SrcList*);
int sqlite3IsReadOnly(Parse*, Table*, int);
void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,Expr*,char*);
#endif
void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
void sqlite3WhereEnd(WhereInfo*);
LogEst sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereOrderedInnerLoop(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);
................................................................................
void sqlite3RegisterDateTimeFunctions(void);
void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);
int sqlite3SafetyCheckOk(sqlite3*);
int sqlite3SafetyCheckSickOrOk(sqlite3*);
void sqlite3ChangeCookie(Parse*, int);

#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
void sqlite3MaterializeView(Parse*, Table*, Expr*, int);
#endif

#ifndef SQLITE_OMIT_TRIGGER
  void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
                           Expr*,int, int);
  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
  void sqlite3DropTrigger(Parse*, SrcList*, int);

};

/*
** The following are the meanings of bits in the Expr.flags field.
*/
#define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */
#define EP_Agg       0x000002 /* Contains one or more aggregate functions */
#define EP_HasFunc   0x000004 /* Contains one or more functions of any kind */
                  /* 0x000008 // available for use */
#define EP_Distinct  0x000010 /* Aggregate function with DISTINCT keyword */
#define EP_VarSelect 0x000020 /* pSelect is correlated, not constant */
#define EP_DblQuoted 0x000040 /* token.z was originally in "..." */
#define EP_InfixFunc 0x000080 /* True for an infix function: LIKE, GLOB, etc */
#define EP_Collate   0x000100 /* Tree contains a TK_COLLATE operator */
#define EP_Generic   0x000200 /* Ignore COLLATE or affinity on this tree */
................................................................................
#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
#define EP_Alias     0x400000 /* Is an alias for a result set column */
#define EP_Leaf      0x800000 /* Expr.pLeft, .pRight, .u.pSelect all NULL */

/*
** The EP_Propagate mask is a set of properties that automatically propagate
** upwards into parent nodes.
*/
#define EP_Propagate (EP_Collate|EP_Subquery|EP_HasFunc)

/*
** These macros can be used to test, set, or clear bits in the
** Expr.flags field.
*/
#define ExprHasProperty(E,P)     (((E)->flags&(P))!=0)
#define ExprHasAllProperty(E,P)  (((E)->flags&(P))==(P))
................................................................................
#define NC_PartIdx   0x0002  /* True if resolving a partial index WHERE */
#define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
#define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
#define NC_HasAgg    0x0010  /* One or more aggregate functions seen */
#define NC_IdxExpr   0x0020  /* True if resolving columns of CREATE INDEX */
#define NC_VarSelect 0x0040  /* A correlated subquery has been seen */
#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */
#define NC_Complex   0x2000  /* True if a function or subquery seen */

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
** If there is a LIMIT clause, the parser sets nLimit to the value of the
................................................................................
  Expr *pWhere;          /* The WHERE clause */
  ExprList *pGroupBy;    /* The GROUP BY clause */
  Expr *pHaving;         /* The HAVING clause */
  ExprList *pOrderBy;    /* The ORDER BY clause */
  Select *pPrior;        /* Prior select in a compound select statement */
  Select *pNext;         /* Next select to the left in a compound */
  Expr *pLimit;          /* LIMIT expression. NULL means not used. */

  With *pWith;           /* WITH clause attached to this select. Or NULL. */
};

/*
** Allowed values for Select.selFlags.  The "SF" prefix stands for
** "Select Flag".
**
................................................................................
#define SF_NestedFrom     0x00800  /* Part of a parenthesized FROM clause */
#define SF_MinMaxAgg      0x01000  /* Aggregate containing min() or max() */
#define SF_Recursive      0x02000  /* The recursive part of a recursive CTE */
#define SF_FixedLimit     0x04000  /* nSelectRow set by a constant LIMIT */
#define SF_MaybeConvert   0x08000  /* Need convertCompoundSelectToSubquery() */
#define SF_Converted      0x10000  /* By convertCompoundSelectToSubquery() */
#define SF_IncludeHidden  0x20000  /* Include hidden columns in output */
#define SF_ComplexResult  0x40000  /* Result set contains subquery or function */


/*
** The results of a SELECT can be distributed in several ways, as defined
** by one of the following macros.  The "SRT" prefix means "SELECT Result
** Type".
**
................................................................................
void sqlite3SrcListDelete(sqlite3*, SrcList*);
Index *sqlite3AllocateIndexObject(sqlite3*,i16,int,char**);
void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
                          Expr*, int, int, u8);
void sqlite3DropIndex(Parse*, SrcList*, int);
int sqlite3Select(Parse*, Select*, SelectDest*);
Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,u32,Expr*);
void sqlite3SelectDelete(sqlite3*, Select*);
Table *sqlite3SrcListLookup(Parse*, SrcList*);
int sqlite3IsReadOnly(Parse*, Table*, int);
void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,char*);
#endif
void sqlite3DeleteFrom(Parse*, SrcList*, Expr*, ExprList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*,Expr*,int,ExprList*,Expr*);
WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
void sqlite3WhereEnd(WhereInfo*);
LogEst sqlite3WhereOutputRowCount(WhereInfo*);
int sqlite3WhereIsDistinct(WhereInfo*);
int sqlite3WhereIsOrdered(WhereInfo*);
int sqlite3WhereOrderedInnerLoop(WhereInfo*);
int sqlite3WhereIsSorted(WhereInfo*);
................................................................................
void sqlite3RegisterDateTimeFunctions(void);
void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);
int sqlite3SafetyCheckOk(sqlite3*);
int sqlite3SafetyCheckSickOrOk(sqlite3*);
void sqlite3ChangeCookie(Parse*, int);

#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
void sqlite3MaterializeView(Parse*, Table*, Expr*, ExprList*,Expr*,int);
#endif

#ifndef SQLITE_OMIT_TRIGGER
  void sqlite3BeginTrigger(Parse*, Token*,Token*,int,int,IdList*,SrcList*,
                           Expr*,int, int);
  void sqlite3FinishTrigger(Parse*, TriggerStep*, Token*);
  void sqlite3DropTrigger(Parse*, SrcList*, int);

#endif

#ifdef SQLITE_ENABLE_JSON1
  Tcl_SetVar2(interp, "sqlite_options", "json1", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "json1", "0", TCL_GLOBAL_ONLY);
#endif







#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  Tcl_SetVar2(interp, "sqlite_options", "like_match_blobs", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "like_match_blobs", "1", TCL_GLOBAL_ONLY);
#endif

#endif

#ifdef SQLITE_ENABLE_JSON1
  Tcl_SetVar2(interp, "sqlite_options", "json1", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "json1", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_HAS_CODEC
  Tcl_SetVar2(interp, "sqlite_options", "has_codec", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "has_codec", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  Tcl_SetVar2(interp, "sqlite_options", "like_match_blobs", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "like_match_blobs", "1", TCL_GLOBAL_ONLY);
#endif

      n = 0;
      if( p->pSrc && p->pSrc->nSrc ) n++;
      if( p->pWhere ) n++;
      if( p->pGroupBy ) n++;
      if( p->pHaving ) n++;
      if( p->pOrderBy ) n++;
      if( p->pLimit ) n++;
      if( p->pOffset ) n++;
    }
    sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set");
    if( p->pSrc && p->pSrc->nSrc ){
      int i;
      pView = sqlite3TreeViewPush(pView, (n--)>0);
      sqlite3TreeViewLine(pView, "FROM");
      for(i=0; i<p->pSrc->nSrc; i++){
................................................................................
      sqlite3TreeViewPop(pView);
    }
    if( p->pOrderBy ){
      sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY");
    }
    if( p->pLimit ){
      sqlite3TreeViewItem(pView, "LIMIT", (n--)>0);



      sqlite3TreeViewExpr(pView, p->pLimit, 0);
      sqlite3TreeViewPop(pView);
    }
    if( p->pOffset ){
      sqlite3TreeViewItem(pView, "OFFSET", (n--)>0);
      sqlite3TreeViewExpr(pView, p->pOffset, 0);
      sqlite3TreeViewPop(pView);
    }
    if( p->pPrior ){
      const char *zOp = "UNION";
      switch( p->op ){
        case TK_ALL:         zOp = "UNION ALL";  break;
        case TK_INTERSECT:   zOp = "INTERSECT";  break;

      n = 0;
      if( p->pSrc && p->pSrc->nSrc ) n++;
      if( p->pWhere ) n++;
      if( p->pGroupBy ) n++;
      if( p->pHaving ) n++;
      if( p->pOrderBy ) n++;
      if( p->pLimit ) n++;

    }
    sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set");
    if( p->pSrc && p->pSrc->nSrc ){
      int i;
      pView = sqlite3TreeViewPush(pView, (n--)>0);
      sqlite3TreeViewLine(pView, "FROM");
      for(i=0; i<p->pSrc->nSrc; i++){
................................................................................
      sqlite3TreeViewPop(pView);
    }
    if( p->pOrderBy ){
      sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY");
    }
    if( p->pLimit ){
      sqlite3TreeViewItem(pView, "LIMIT", (n--)>0);
      sqlite3TreeViewExpr(pView, p->pLimit->pLeft, p->pLimit->pRight!=0);
      if( p->pLimit->pRight ){
        sqlite3TreeViewItem(pView, "OFFSET", (n--)>0);
        sqlite3TreeViewExpr(pView, p->pLimit->pRight, 0);
        sqlite3TreeViewPop(pView);
      }



      sqlite3TreeViewPop(pView);
    }
    if( p->pPrior ){
      const char *zOp = "UNION";
      switch( p->op ){
        case TK_ALL:         zOp = "UNION ALL";  break;
        case TK_INTERSECT:   zOp = "INTERSECT";  break;

    switch( pStep->op ){
      case TK_UPDATE: {
        sqlite3Update(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3ExprDup(db, pStep->pWhere, 0), 
          pParse->eOrconf
        );
        break;
      }
      case TK_INSERT: {
        sqlite3Insert(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3SelectDup(db, pStep->pSelect, 0), 
................................................................................
          pParse->eOrconf
        );
        break;
      }
      case TK_DELETE: {
        sqlite3DeleteFrom(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprDup(db, pStep->pWhere, 0)
        );
        break;
      }
      default: assert( pStep->op==TK_SELECT ); {
        SelectDest sDest;
        Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
        sqlite3SelectDestInit(&sDest, SRT_Discard, 0);

    switch( pStep->op ){
      case TK_UPDATE: {
        sqlite3Update(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprListDup(db, pStep->pExprList, 0), 
          sqlite3ExprDup(db, pStep->pWhere, 0), 
          pParse->eOrconf, 0, 0
        );
        break;
      }
      case TK_INSERT: {
        sqlite3Insert(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3SelectDup(db, pStep->pSelect, 0), 
................................................................................
          pParse->eOrconf
        );
        break;
      }
      case TK_DELETE: {
        sqlite3DeleteFrom(pParse, 
          targetSrcList(pParse, pStep),
          sqlite3ExprDup(db, pStep->pWhere, 0), 0, 0
        );
        break;
      }
      default: assert( pStep->op==TK_SELECT ); {
        SelectDest sDest;
        Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
        sqlite3SelectDestInit(&sDest, SRT_Discard, 0);

*            onError   pTabList      pChanges             pWhere
*/
void sqlite3Update(
  Parse *pParse,         /* The parser context */
  SrcList *pTabList,     /* The table in which we should change things */
  ExprList *pChanges,    /* Things to be changed */
  Expr *pWhere,          /* The WHERE clause.  May be null */
  int onError            /* How to handle constraint errors */


){
  int i, j;              /* Loop counters */
  Table *pTab;           /* The table to be updated */
  int addrTop = 0;       /* VDBE instruction address of the start of the loop */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Vdbe *v;               /* The virtual database engine */
  Index *pIdx;           /* For looping over indices */
................................................................................
# define isView 0
# define tmask 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif











  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto update_cleanup;
  }
  if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
    goto update_cleanup;
  }
................................................................................
  }

  /* If we are trying to update a view, realize that view into
  ** an ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur);




  }
#endif

  /* Resolve the column names in all the expressions in the
  ** WHERE clause.
  */
  if( sqlite3ResolveExprNames(&sNC, pWhere) ){
................................................................................

update_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprListDelete(db, pChanges);
  sqlite3ExprDelete(db, pWhere);




  return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation).  */
#ifdef isView
 #undef isView

*            onError   pTabList      pChanges             pWhere
*/
void sqlite3Update(
  Parse *pParse,         /* The parser context */
  SrcList *pTabList,     /* The table in which we should change things */
  ExprList *pChanges,    /* Things to be changed */
  Expr *pWhere,          /* The WHERE clause.  May be null */
  int onError,           /* How to handle constraint errors */
  ExprList *pOrderBy,    /* ORDER BY clause. May be null */
  Expr *pLimit           /* LIMIT clause. May be null */
){
  int i, j;              /* Loop counters */
  Table *pTab;           /* The table to be updated */
  int addrTop = 0;       /* VDBE instruction address of the start of the loop */
  WhereInfo *pWInfo;     /* Information about the WHERE clause */
  Vdbe *v;               /* The virtual database engine */
  Index *pIdx;           /* For looping over indices */
................................................................................
# define isView 0
# define tmask 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif

#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  if( !isView ){
    pWhere = sqlite3LimitWhere(
        pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE"
    );
    pOrderBy = 0;
    pLimit = 0;
  }
#endif

  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto update_cleanup;
  }
  if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
    goto update_cleanup;
  }
................................................................................
  }

  /* If we are trying to update a view, realize that view into
  ** an ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, 
        pWhere, pOrderBy, pLimit, iDataCur
    );
    pOrderBy = 0;
    pLimit = 0;
  }
#endif

  /* Resolve the column names in all the expressions in the
  ** WHERE clause.
  */
  if( sqlite3ResolveExprNames(&sNC, pWhere) ){
................................................................................

update_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprListDelete(db, pChanges);
  sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) 
  sqlite3ExprListDelete(db, pOrderBy);
  sqlite3ExprDelete(db, pLimit);
#endif
  return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation).  */
#ifdef isView
 #undef isView

  }else if( *z=='+' ){
    z+=incr;
  }

  /* copy max significant digits to significand */
  while( z<zEnd && sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){
    s = s*10 + (*z - '0');
    z+=incr, nDigits++;
  }

  /* skip non-significant significand digits
  ** (increase exponent by d to shift decimal left) */
  while( z<zEnd && sqlite3Isdigit(*z) ) z+=incr, nDigits++, d++;
  if( z>=zEnd ) goto do_atof_calc;

  /* if decimal point is present */
  if( *z=='.' ){
    z+=incr;
    /* copy digits from after decimal to significand
    ** (decrease exponent by d to shift decimal right) */
    while( z<zEnd && sqlite3Isdigit(*z) ){
      if( s<((LARGEST_INT64-9)/10) ){
        s = s*10 + (*z - '0');
        d--;
      }
      z+=incr, nDigits++;
    }
  }
  if( z>=zEnd ) goto do_atof_calc;

  /* if exponent is present */
  if( *z=='e' || *z=='E' ){
    z+=incr;

  }else if( *z=='+' ){
    z+=incr;
  }

  /* copy max significant digits to significand */
  while( z<zEnd && sqlite3Isdigit(*z) && s<((LARGEST_INT64-9)/10) ){
    s = s*10 + (*z - '0');
    z+=incr; nDigits++;
  }

  /* skip non-significant significand digits
  ** (increase exponent by d to shift decimal left) */
  while( z<zEnd && sqlite3Isdigit(*z) ){ z+=incr; nDigits++; d++; }
  if( z>=zEnd ) goto do_atof_calc;

  /* if decimal point is present */
  if( *z=='.' ){
    z+=incr;
    /* copy digits from after decimal to significand
    ** (decrease exponent by d to shift decimal right) */
    while( z<zEnd && sqlite3Isdigit(*z) ){
      if( s<((LARGEST_INT64-9)/10) ){
        s = s*10 + (*z - '0');
        d--;
      }
      z+=incr; nDigits++;
    }
  }
  if( z>=zEnd ) goto do_atof_calc;

  /* if exponent is present */
  if( *z=='e' || *z=='E' ){
    z+=incr;

    sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, x.nKey, pOp->p2);
  }
  if( pOp->p5 & OPFLAG_ISNOOP ) break;
#endif

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = x.nKey;
  if( pData->flags & MEM_Null ){
    x.pData = 0;
    x.nData = 0;
  }else{
    assert( pData->flags & (MEM_Blob|MEM_Str) );
    x.pData = pData->z;
    x.nData = pData->n;
  }
  seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
  if( pData->flags & MEM_Zero ){
    x.nZero = pData->u.nZero;
  }else{
    x.nZero = 0;
  }
  x.pKey = 0;

    sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, x.nKey, pOp->p2);
  }
  if( pOp->p5 & OPFLAG_ISNOOP ) break;
#endif

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = x.nKey;




  assert( pData->flags & (MEM_Blob|MEM_Str) );
  x.pData = pData->z;
  x.nData = pData->n;

  seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
  if( pData->flags & MEM_Zero ){
    x.nZero = pData->u.nZero;
  }else{
    x.nZero = 0;
  }
  x.pKey = 0;

/*
** Delete an entire VDBE.
*/
void sqlite3VdbeDelete(Vdbe *p){
  sqlite3 *db;

  if( NEVER(p==0) ) return;
  db = p->db;
  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3VdbeClearObject(db, p);
  if( p->pPrev ){
    p->pPrev->pNext = p->pNext;
  }else{
    assert( db->pVdbe==p );

/*
** Delete an entire VDBE.
*/
void sqlite3VdbeDelete(Vdbe *p){
  sqlite3 *db;

  assert( p!=0 );
  db = p->db;
  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3VdbeClearObject(db, p);
  if( p->pPrev ){
    p->pPrev->pNext = p->pNext;
  }else{
    assert( db->pVdbe==p );

  /* Set the value of register r[1] in the SQL statement to integer iRow. 
  ** This is done directly as a performance optimization
  */
  v->aMem[1].flags = MEM_Int;
  v->aMem[1].u.i = iRow;

  /* If the statement has been run before (and is paused at the OP_ResultRow)
  ** then back it up to the point where it does the OP_SeekRowid.  This could
  ** have been down with an extra OP_Goto, but simply setting the program
  ** counter is faster. */
  if( v->pc>3 ){
    v->pc = 3;

    rc = sqlite3VdbeExec(v);
  }else{
    rc = sqlite3_step(p->pStmt);
  }
  if( rc==SQLITE_ROW ){
    VdbeCursor *pC = v->apCsr[0];
    u32 type = pC->nHdrParsed>p->iCol ? pC->aType[p->iCol] : 0;

  /* Set the value of register r[1] in the SQL statement to integer iRow. 
  ** This is done directly as a performance optimization
  */
  v->aMem[1].flags = MEM_Int;
  v->aMem[1].u.i = iRow;

  /* If the statement has been run before (and is paused at the OP_ResultRow)
  ** then back it up to the point where it does the OP_NotExists.  This could
  ** have been down with an extra OP_Goto, but simply setting the program
  ** counter is faster. */
  if( v->pc>4 ){
    v->pc = 4;
    assert( v->aOp[v->pc].opcode==OP_NotExists );
    rc = sqlite3VdbeExec(v);
  }else{
    rc = sqlite3_step(p->pStmt);
  }
  if( rc==SQLITE_ROW ){
    VdbeCursor *pC = v->apCsr[0];
    u32 type = pC->nHdrParsed>p->iCol ? pC->aType[p->iCol] : 0;

** This routine calls the finalize method for that function.  The
** result of the aggregate is stored back into pMem.
**
** Return SQLITE_ERROR if the finalizer reports an error.  SQLITE_OK
** otherwise.
*/
int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){
  int rc = SQLITE_OK;
  if( ALWAYS(pFunc && pFunc->xFinalize) ){
    sqlite3_context ctx;
    Mem t;


    assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
    assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
    memset(&ctx, 0, sizeof(ctx));
    memset(&t, 0, sizeof(t));
    t.flags = MEM_Null;
    t.db = pMem->db;
    ctx.pOut = &t;
    ctx.pMem = pMem;
    ctx.pFunc = pFunc;
    pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
    assert( (pMem->flags & MEM_Dyn)==0 );
    if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
    memcpy(pMem, &t, sizeof(t));
    rc = ctx.isError;
  }
  return rc;
}

/*
** If the memory cell contains a value that must be freed by
** invoking the external callback in Mem.xDel, then this routine
** will free that value.  It also sets Mem.flags to MEM_Null.
**

** This routine calls the finalize method for that function.  The
** result of the aggregate is stored back into pMem.
**
** Return SQLITE_ERROR if the finalizer reports an error.  SQLITE_OK
** otherwise.
*/
int sqlite3VdbeMemFinalize(Mem *pMem, FuncDef *pFunc){


  sqlite3_context ctx;
  Mem t;
  assert( pFunc!=0 );
  assert( pFunc->xFinalize!=0 );
  assert( (pMem->flags & MEM_Null)!=0 || pFunc==pMem->u.pDef );
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  memset(&ctx, 0, sizeof(ctx));
  memset(&t, 0, sizeof(t));
  t.flags = MEM_Null;
  t.db = pMem->db;
  ctx.pOut = &t;
  ctx.pMem = pMem;
  ctx.pFunc = pFunc;
  pFunc->xFinalize(&ctx); /* IMP: R-24505-23230 */
  assert( (pMem->flags & MEM_Dyn)==0 );
  if( pMem->szMalloc>0 ) sqlite3DbFreeNN(pMem->db, pMem->zMalloc);
  memcpy(pMem, &t, sizeof(t));
  return ctx.isError;


}

/*
** If the memory cell contains a value that must be freed by
** invoking the external callback in Mem.xDel, then this routine
** will free that value.  It also sets Mem.flags to MEM_Null.
**

** WAL-INDEX FORMAT
**
** Conceptually, the wal-index is shared memory, though VFS implementations
** might choose to implement the wal-index using a mmapped file.  Because
** the wal-index is shared memory, SQLite does not support journal_mode=WAL 
** on a network filesystem.  All users of the database must be able to
** share memory.




**
** The wal-index is transient.  After a crash, the wal-index can (and should
** be) reconstructed from the original WAL file.  In fact, the VFS is required
** to either truncate or zero the header of the wal-index when the last
** connection to it closes.  Because the wal-index is transient, it can
** use an architecture-specific format; it does not have to be cross-platform.
** Hence, unlike the database and WAL file formats which store all values
................................................................................
** WALINDEX_MAX_VERSION, then no read-transaction is opened and SQLite
** returns SQLITE_CANTOPEN.
*/
#define WAL_MAX_VERSION      3007000
#define WALINDEX_MAX_VERSION 3007000

/*
** Indices of various locking bytes.   WAL_NREADER is the number
** of available reader locks and should be at least 3.  The default
** is SQLITE_SHM_NLOCK==8 and  WAL_NREADER==5.









*/
#define WAL_WRITE_LOCK         0
#define WAL_ALL_BUT_WRITE      1
#define WAL_CKPT_LOCK          1
#define WAL_RECOVER_LOCK       2
#define WAL_READ_LOCK(I)       (3+(I))
#define WAL_NREADER            (SQLITE_SHM_NLOCK-3)
................................................................................
#define WALINDEX_LOCK_OFFSET (sizeof(WalIndexHdr)*2+offsetof(WalCkptInfo,aLock))
#define WALINDEX_HDR_SIZE    (sizeof(WalIndexHdr)*2+sizeof(WalCkptInfo))

/* Size of header before each frame in wal */
#define WAL_FRAME_HDRSIZE 24

/* Size of write ahead log header, including checksum. */
/* #define WAL_HDRSIZE 24 */
#define WAL_HDRSIZE 32

/* WAL magic value. Either this value, or the same value with the least
** significant bit also set (WAL_MAGIC | 0x00000001) is stored in 32-bit
** big-endian format in the first 4 bytes of a WAL file.
**
** If the LSB is set, then the checksums for each frame within the WAL
................................................................................
  u8 exclusiveMode;          /* Non-zero if connection is in exclusive mode */
  u8 writeLock;              /* True if in a write transaction */
  u8 ckptLock;               /* True if holding a checkpoint lock */
  u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
  u8 truncateOnCommit;       /* True to truncate WAL file on commit */
  u8 syncHeader;             /* Fsync the WAL header if true */
  u8 padToSectorBoundary;    /* Pad transactions out to the next sector */

  WalIndexHdr hdr;           /* Wal-index header for current transaction */
  u32 minFrame;              /* Ignore wal frames before this one */
  u32 iReCksum;              /* On commit, recalculate checksums from here */
  const char *zWalName;      /* Name of WAL file */
  u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
#ifdef SQLITE_DEBUG
  u8 lockError;              /* True if a locking error has occurred */
................................................................................
    sizeof(ht_slot)*HASHTABLE_NSLOT + HASHTABLE_NPAGE*sizeof(u32) \
)

/*
** Obtain a pointer to the iPage'th page of the wal-index. The wal-index
** is broken into pages of WALINDEX_PGSZ bytes. Wal-index pages are
** numbered from zero.





**
** If this call is successful, *ppPage is set to point to the wal-index
** page and SQLITE_OK is returned. If an error (an OOM or VFS error) occurs,
** then an SQLite error code is returned and *ppPage is set to 0.
*/
static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
  int rc = SQLITE_OK;
................................................................................
    if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){
      pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);
      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;
    }else{
      rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
          pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
      );


      if( rc==SQLITE_READONLY ){
        pWal->readOnly |= WAL_SHM_RDONLY;

        rc = SQLITE_OK;

      }
    }
  }

  *ppPage = pWal->apWiData[iPage];
  assert( iPage==0 || *ppPage || rc!=SQLITE_OK );
  return rc;
................................................................................
** the necessary locks, this routine returns SQLITE_BUSY.
*/
static int walIndexRecover(Wal *pWal){
  int rc;                         /* Return Code */
  i64 nSize;                      /* Size of log file */
  u32 aFrameCksum[2] = {0, 0};
  int iLock;                      /* Lock offset to lock for checkpoint */
  int nLock;                      /* Number of locks to hold */

  /* Obtain an exclusive lock on all byte in the locking range not already
  ** locked by the caller. The caller is guaranteed to have locked the
  ** WAL_WRITE_LOCK byte, and may have also locked the WAL_CKPT_LOCK byte.
  ** If successful, the same bytes that are locked here are unlocked before
  ** this function returns.
  */
  assert( pWal->ckptLock==1 || pWal->ckptLock==0 );
  assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );
  assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );
  assert( pWal->writeLock );
  iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;
  nLock = SQLITE_SHM_NLOCK - iLock;
  rc = walLockExclusive(pWal, iLock, nLock);






  if( rc ){
    return rc;
  }

  WALTRACE(("WAL%p: recovery begin...\n", pWal));

  memset(&pWal->hdr, 0, sizeof(WalIndexHdr));

  rc = sqlite3OsFileSize(pWal->pWalFd, &nSize);
  if( rc!=SQLITE_OK ){
    goto recovery_error;
................................................................................
          pWal->hdr.mxFrame, pWal->zWalName
      );
    }
  }

recovery_error:
  WALTRACE(("WAL%p: recovery %s\n", pWal, rc ? "failed" : "ok"));
  walUnlockExclusive(pWal, iLock, nLock);

  return rc;
}

/*
** Close an open wal-index.
*/
static void walIndexClose(Wal *pWal, int isDelete){
  if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){
    int i;
    for(i=0; i<pWal->nWiData; i++){
      sqlite3_free((void *)pWal->apWiData[i]);
      pWal->apWiData[i] = 0;
    }
  }else{

    sqlite3OsShmUnmap(pWal->pDbFd, isDelete);
  }
}

/* 
** Open a connection to the WAL file zWalName. The database file must 
** already be opened on connection pDbFd. The buffer that zWalName points
................................................................................
    testcase( pWal->szPage>=65536 );
  }

  /* The header was successfully read. Return zero. */
  return 0;
}







/*
** Read the wal-index header from the wal-index and into pWal->hdr.
** If the wal-header appears to be corrupt, try to reconstruct the
** wal-index from the WAL before returning.
**
** Set *pChanged to 1 if the wal-index header value in pWal->hdr is
** changed by this operation.  If pWal->hdr is unchanged, set *pChanged
................................................................................

  /* Ensure that page 0 of the wal-index (the page that contains the 
  ** wal-index header) is mapped. Return early if an error occurs here.
  */
  assert( pChanged );
  rc = walIndexPage(pWal, 0, &page0);
  if( rc!=SQLITE_OK ){
    return rc;
  };








  assert( page0 || pWal->writeLock==0 );














  /* If the first page of the wal-index has been mapped, try to read the
  ** wal-index header immediately, without holding any lock. This usually
  ** works, but may fail if the wal-index header is corrupt or currently 
  ** being modified by another thread or process.
  */
  badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);

  /* If the first attempt failed, it might have been due to a race
  ** with a writer.  So get a WRITE lock and try again.
  */
  assert( badHdr==0 || pWal->writeLock==0 );
  if( badHdr ){
    if( pWal->readOnly & WAL_SHM_RDONLY ){
      if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
        walUnlockShared(pWal, WAL_WRITE_LOCK);
        rc = SQLITE_READONLY_RECOVERY;
      }
    }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
      pWal->writeLock = 1;
      if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
................................................................................
  /* If the header is read successfully, check the version number to make
  ** sure the wal-index was not constructed with some future format that
  ** this version of SQLite cannot understand.
  */
  if( badHdr==0 && pWal->hdr.iVersion!=WALINDEX_MAX_VERSION ){
    rc = SQLITE_CANTOPEN_BKPT;
  }













  return rc;
}

/*
** This is the value that walTryBeginRead returns when it needs to
** be retried.

























*/
























































































#define WAL_RETRY  (-1)
























































/*
** Attempt to start a read transaction.  This might fail due to a race or
** other transient condition.  When that happens, it returns WAL_RETRY to
** indicate to the caller that it is safe to retry immediately.
**
** On success return SQLITE_OK.  On a permanent failure (such an
................................................................................
** recovery) return a positive error code.
**
** The useWal parameter is true to force the use of the WAL and disable
** the case where the WAL is bypassed because it has been completely
** checkpointed.  If useWal==0 then this routine calls walIndexReadHdr() 
** to make a copy of the wal-index header into pWal->hdr.  If the 
** wal-index header has changed, *pChanged is set to 1 (as an indication 
** to the caller that the local paget cache is obsolete and needs to be 
** flushed.)  When useWal==1, the wal-index header is assumed to already
** be loaded and the pChanged parameter is unused.
**
** The caller must set the cnt parameter to the number of prior calls to
** this routine during the current read attempt that returned WAL_RETRY.
** This routine will start taking more aggressive measures to clear the
** race conditions after multiple WAL_RETRY returns, and after an excessive
................................................................................
  int mxI;                        /* Index of largest aReadMark[] value */
  int i;                          /* Loop counter */
  int rc = SQLITE_OK;             /* Return code  */
  u32 mxFrame;                    /* Wal frame to lock to */

  assert( pWal->readLock<0 );     /* Not currently locked */




  /* Take steps to avoid spinning forever if there is a protocol error.
  **
  ** Circumstances that cause a RETRY should only last for the briefest
  ** instances of time.  No I/O or other system calls are done while the
  ** locks are held, so the locks should not be held for very long. But 
  ** if we are unlucky, another process that is holding a lock might get
  ** paged out or take a page-fault that is time-consuming to resolve, 
................................................................................
      return SQLITE_PROTOCOL;
    }
    if( cnt>=10 ) nDelay = (cnt-9)*(cnt-9)*39;
    sqlite3OsSleep(pWal->pVfs, nDelay);
  }

  if( !useWal ){


    rc = walIndexReadHdr(pWal, pChanged);

    if( rc==SQLITE_BUSY ){
      /* If there is not a recovery running in another thread or process
      ** then convert BUSY errors to WAL_RETRY.  If recovery is known to
      ** be running, convert BUSY to BUSY_RECOVERY.  There is a race here
      ** which might cause WAL_RETRY to be returned even if BUSY_RECOVERY
      ** would be technically correct.  But the race is benign since with
      ** WAL_RETRY this routine will be called again and will probably be
................................................................................
      }else if( rc==SQLITE_BUSY ){
        rc = SQLITE_BUSY_RECOVERY;
      }
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }


  }




  pInfo = walCkptInfo(pWal);
  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame 
#ifdef SQLITE_ENABLE_SNAPSHOT
   && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0
     || 0==memcmp(&pWal->hdr, pWal->pSnapshot, sizeof(WalIndexHdr)))
#endif
  ){
    /* The WAL has been completely backfilled (or it is empty).
    ** and can be safely ignored.
................................................................................
      }else if( rc!=SQLITE_BUSY ){
        return rc;
      }
    }
  }
  if( mxI==0 ){
    assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
    return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
  }

  rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
  if( rc ){
    return rc==SQLITE_BUSY ? WAL_RETRY : rc;
  }
  /* Now that the read-lock has been obtained, check that neither the
................................................................................

  /* If the "last page" field of the wal-index header snapshot is 0, then
  ** no data will be read from the wal under any circumstances. Return early
  ** in this case as an optimization.  Likewise, if pWal->readLock==0, 
  ** then the WAL is ignored by the reader so return early, as if the 
  ** WAL were empty.
  */
  if( iLast==0 || pWal->readLock==0 ){
    *piRead = 0;
    return SQLITE_OK;
  }

  /* Search the hash table or tables for an entry matching page number
  ** pgno. Each iteration of the following for() loop searches one
  ** hash table (each hash table indexes up to HASHTABLE_NPAGE frames).
................................................................................
#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
  /* If expensive assert() statements are available, do a linear search
  ** of the wal-index file content. Make sure the results agree with the
  ** result obtained using the hash indexes above.  */
  {
    u32 iRead2 = 0;
    u32 iTest;
    assert( pWal->minFrame>0 );
    for(iTest=iLast; iTest>=pWal->minFrame; iTest--){
      if( walFramePgno(pWal, iTest)==pgno ){
        iRead2 = iTest;
        break;
      }
    }
    assert( iRead==iRead2 );
  }
................................................................................
  ** locks are taken in this case). Nor should the pager attempt to
  ** upgrade to exclusive-mode following such an error.
  */
  assert( pWal->readLock>=0 || pWal->lockError );
  assert( pWal->readLock>=0 || (op<=0 && pWal->exclusiveMode==0) );

  if( op==0 ){
    if( pWal->exclusiveMode ){
      pWal->exclusiveMode = 0;
      if( walLockShared(pWal, WAL_READ_LOCK(pWal->readLock))!=SQLITE_OK ){
        pWal->exclusiveMode = 1;
      }
      rc = pWal->exclusiveMode==0;
    }else{
      /* Already in locking_mode=NORMAL */
      rc = 0;
    }
  }else if( op>0 ){
    assert( pWal->exclusiveMode==0 );
    assert( pWal->readLock>=0 );
    walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock));
    pWal->exclusiveMode = 1;
    rc = 1;
  }else{
    rc = pWal->exclusiveMode==0;
  }
  return rc;
}

/* 
** Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the

** WAL-INDEX FORMAT
**
** Conceptually, the wal-index is shared memory, though VFS implementations
** might choose to implement the wal-index using a mmapped file.  Because
** the wal-index is shared memory, SQLite does not support journal_mode=WAL 
** on a network filesystem.  All users of the database must be able to
** share memory.
**
** In the default unix and windows implementation, the wal-index is a mmapped
** file whose name is the database name with a "-shm" suffix added.  For that
** reason, the wal-index is sometimes called the "shm" file.
**
** The wal-index is transient.  After a crash, the wal-index can (and should
** be) reconstructed from the original WAL file.  In fact, the VFS is required
** to either truncate or zero the header of the wal-index when the last
** connection to it closes.  Because the wal-index is transient, it can
** use an architecture-specific format; it does not have to be cross-platform.
** Hence, unlike the database and WAL file formats which store all values
................................................................................
** WALINDEX_MAX_VERSION, then no read-transaction is opened and SQLite
** returns SQLITE_CANTOPEN.
*/
#define WAL_MAX_VERSION      3007000
#define WALINDEX_MAX_VERSION 3007000

/*
** Index numbers for various locking bytes.   WAL_NREADER is the number
** of available reader locks and should be at least 3.  The default
** is SQLITE_SHM_NLOCK==8 and  WAL_NREADER==5.
**
** Technically, the various VFSes are free to implement these locks however
** they see fit.  However, compatibility is encouraged so that VFSes can
** interoperate.  The standard implemention used on both unix and windows
** is for the index number to indicate a byte offset into the
** WalCkptInfo.aLock[] array in the wal-index header.  In other words, all
** locks are on the shm file.  The WALINDEX_LOCK_OFFSET constant (which
** should be 120) is the location in the shm file for the first locking
** byte.
*/
#define WAL_WRITE_LOCK         0
#define WAL_ALL_BUT_WRITE      1
#define WAL_CKPT_LOCK          1
#define WAL_RECOVER_LOCK       2
#define WAL_READ_LOCK(I)       (3+(I))
#define WAL_NREADER            (SQLITE_SHM_NLOCK-3)
................................................................................
#define WALINDEX_LOCK_OFFSET (sizeof(WalIndexHdr)*2+offsetof(WalCkptInfo,aLock))
#define WALINDEX_HDR_SIZE    (sizeof(WalIndexHdr)*2+sizeof(WalCkptInfo))

/* Size of header before each frame in wal */
#define WAL_FRAME_HDRSIZE 24

/* Size of write ahead log header, including checksum. */

#define WAL_HDRSIZE 32

/* WAL magic value. Either this value, or the same value with the least
** significant bit also set (WAL_MAGIC | 0x00000001) is stored in 32-bit
** big-endian format in the first 4 bytes of a WAL file.
**
** If the LSB is set, then the checksums for each frame within the WAL
................................................................................
  u8 exclusiveMode;          /* Non-zero if connection is in exclusive mode */
  u8 writeLock;              /* True if in a write transaction */
  u8 ckptLock;               /* True if holding a checkpoint lock */
  u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
  u8 truncateOnCommit;       /* True to truncate WAL file on commit */
  u8 syncHeader;             /* Fsync the WAL header if true */
  u8 padToSectorBoundary;    /* Pad transactions out to the next sector */
  u8 bShmUnreliable;         /* SHM content is read-only and unreliable */
  WalIndexHdr hdr;           /* Wal-index header for current transaction */
  u32 minFrame;              /* Ignore wal frames before this one */
  u32 iReCksum;              /* On commit, recalculate checksums from here */
  const char *zWalName;      /* Name of WAL file */
  u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
#ifdef SQLITE_DEBUG
  u8 lockError;              /* True if a locking error has occurred */
................................................................................
    sizeof(ht_slot)*HASHTABLE_NSLOT + HASHTABLE_NPAGE*sizeof(u32) \
)

/*
** Obtain a pointer to the iPage'th page of the wal-index. The wal-index
** is broken into pages of WALINDEX_PGSZ bytes. Wal-index pages are
** numbered from zero.
**
** If the wal-index is currently smaller the iPage pages then the size
** of the wal-index might be increased, but only if it is safe to do
** so.  It is safe to enlarge the wal-index if pWal->writeLock is true
** or pWal->exclusiveMode==WAL_HEAPMEMORY_MODE.
**
** If this call is successful, *ppPage is set to point to the wal-index
** page and SQLITE_OK is returned. If an error (an OOM or VFS error) occurs,
** then an SQLite error code is returned and *ppPage is set to 0.
*/
static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
  int rc = SQLITE_OK;
................................................................................
    if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE ){
      pWal->apWiData[iPage] = (u32 volatile *)sqlite3MallocZero(WALINDEX_PGSZ);
      if( !pWal->apWiData[iPage] ) rc = SQLITE_NOMEM_BKPT;
    }else{
      rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
          pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
      );
      assert( pWal->apWiData[iPage]!=0 || rc!=SQLITE_OK || pWal->writeLock==0 );
      testcase( pWal->apWiData[iPage]==0 && rc==SQLITE_OK );
      if( (rc&0xff)==SQLITE_READONLY ){
        pWal->readOnly |= WAL_SHM_RDONLY;
        if( rc==SQLITE_READONLY ){
          rc = SQLITE_OK;
        }
      }
    }
  }

  *ppPage = pWal->apWiData[iPage];
  assert( iPage==0 || *ppPage || rc!=SQLITE_OK );
  return rc;
................................................................................
** the necessary locks, this routine returns SQLITE_BUSY.
*/
static int walIndexRecover(Wal *pWal){
  int rc;                         /* Return Code */
  i64 nSize;                      /* Size of log file */
  u32 aFrameCksum[2] = {0, 0};
  int iLock;                      /* Lock offset to lock for checkpoint */


  /* Obtain an exclusive lock on all byte in the locking range not already
  ** locked by the caller. The caller is guaranteed to have locked the
  ** WAL_WRITE_LOCK byte, and may have also locked the WAL_CKPT_LOCK byte.
  ** If successful, the same bytes that are locked here are unlocked before
  ** this function returns.
  */
  assert( pWal->ckptLock==1 || pWal->ckptLock==0 );
  assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );
  assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );
  assert( pWal->writeLock );
  iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;

  rc = walLockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);
  if( rc==SQLITE_OK ){
    rc = walLockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
    if( rc!=SQLITE_OK ){
      walUnlockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);
    }
  }
  if( rc ){
    return rc;
  }

  WALTRACE(("WAL%p: recovery begin...\n", pWal));

  memset(&pWal->hdr, 0, sizeof(WalIndexHdr));

  rc = sqlite3OsFileSize(pWal->pWalFd, &nSize);
  if( rc!=SQLITE_OK ){
    goto recovery_error;
................................................................................
          pWal->hdr.mxFrame, pWal->zWalName
      );
    }
  }

recovery_error:
  WALTRACE(("WAL%p: recovery %s\n", pWal, rc ? "failed" : "ok"));
  walUnlockExclusive(pWal, iLock, WAL_READ_LOCK(0)-iLock);
  walUnlockExclusive(pWal, WAL_READ_LOCK(1), WAL_NREADER-1);
  return rc;
}

/*
** Close an open wal-index.
*/
static void walIndexClose(Wal *pWal, int isDelete){
  if( pWal->exclusiveMode==WAL_HEAPMEMORY_MODE || pWal->bShmUnreliable ){
    int i;
    for(i=0; i<pWal->nWiData; i++){
      sqlite3_free((void *)pWal->apWiData[i]);
      pWal->apWiData[i] = 0;
    }
  }
  if( pWal->exclusiveMode!=WAL_HEAPMEMORY_MODE ){
    sqlite3OsShmUnmap(pWal->pDbFd, isDelete);
  }
}

/* 
** Open a connection to the WAL file zWalName. The database file must 
** already be opened on connection pDbFd. The buffer that zWalName points
................................................................................
    testcase( pWal->szPage>=65536 );
  }

  /* The header was successfully read. Return zero. */
  return 0;
}

/*
** This is the value that walTryBeginRead returns when it needs to
** be retried.
*/
#define WAL_RETRY  (-1)

/*
** Read the wal-index header from the wal-index and into pWal->hdr.
** If the wal-header appears to be corrupt, try to reconstruct the
** wal-index from the WAL before returning.
**
** Set *pChanged to 1 if the wal-index header value in pWal->hdr is
** changed by this operation.  If pWal->hdr is unchanged, set *pChanged
................................................................................

  /* Ensure that page 0 of the wal-index (the page that contains the 
  ** wal-index header) is mapped. Return early if an error occurs here.
  */
  assert( pChanged );
  rc = walIndexPage(pWal, 0, &page0);
  if( rc!=SQLITE_OK ){
    assert( rc!=SQLITE_READONLY ); /* READONLY changed to OK in walIndexPage */

    if( rc==SQLITE_READONLY_CANTINIT ){
      /* The SQLITE_READONLY_CANTINIT return means that the shared-memory
      ** was openable but is not writable, and this thread is unable to
      ** confirm that another write-capable connection has the shared-memory
      ** open, and hence the content of the shared-memory is unreliable,
      ** since the shared-memory might be inconsistent with the WAL file
      ** and there is no writer on hand to fix it. */
      assert( page0==0 );
      assert( pWal->writeLock==0 );
      assert( pWal->readOnly & WAL_SHM_RDONLY );
      pWal->bShmUnreliable = 1;
      pWal->exclusiveMode = WAL_HEAPMEMORY_MODE;
      *pChanged = 1;
    }else{
      return rc; /* Any other non-OK return is just an error */
    }
  }else{
    /* page0 can be NULL if the SHM is zero bytes in size and pWal->writeLock
    ** is zero, which prevents the SHM from growing */
    testcase( page0!=0 );
  }
  assert( page0!=0 || pWal->writeLock==0 );

  /* If the first page of the wal-index has been mapped, try to read the
  ** wal-index header immediately, without holding any lock. This usually
  ** works, but may fail if the wal-index header is corrupt or currently 
  ** being modified by another thread or process.
  */
  badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);

  /* If the first attempt failed, it might have been due to a race
  ** with a writer.  So get a WRITE lock and try again.
  */
  assert( badHdr==0 || pWal->writeLock==0 );
  if( badHdr ){
    if( pWal->bShmUnreliable==0 && (pWal->readOnly & WAL_SHM_RDONLY) ){
      if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
        walUnlockShared(pWal, WAL_WRITE_LOCK);
        rc = SQLITE_READONLY_RECOVERY;
      }
    }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
      pWal->writeLock = 1;
      if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
................................................................................
  /* If the header is read successfully, check the version number to make
  ** sure the wal-index was not constructed with some future format that
  ** this version of SQLite cannot understand.
  */
  if( badHdr==0 && pWal->hdr.iVersion!=WALINDEX_MAX_VERSION ){
    rc = SQLITE_CANTOPEN_BKPT;
  }
  if( pWal->bShmUnreliable ){
    if( rc!=SQLITE_OK ){
      walIndexClose(pWal, 0);
      pWal->bShmUnreliable = 0;
      assert( pWal->nWiData>0 && pWal->apWiData[0]==0 );
      /* walIndexRecover() might have returned SHORT_READ if a concurrent
      ** writer truncated the WAL out from under it.  If that happens, it
      ** indicates that a writer has fixed the SHM file for us, so retry */
      if( rc==SQLITE_IOERR_SHORT_READ ) rc = WAL_RETRY;
    }
    pWal->exclusiveMode = WAL_NORMAL_MODE;
  }

  return rc;
}

/*


** Open a transaction in a connection where the shared-memory is read-only
** and where we cannot verify that there is a separate write-capable connection
** on hand to keep the shared-memory up-to-date with the WAL file.
**
** This can happen, for example, when the shared-memory is implemented by
** memory-mapping a *-shm file, where a prior writer has shut down and
** left the *-shm file on disk, and now the present connection is trying
** to use that database but lacks write permission on the *-shm file.
** Other scenarios are also possible, depending on the VFS implementation.
**
** Precondition:
**
**    The *-wal file has been read and an appropriate wal-index has been
**    constructed in pWal->apWiData[] using heap memory instead of shared
**    memory. 
**
** If this function returns SQLITE_OK, then the read transaction has
** been successfully opened. In this case output variable (*pChanged) 
** is set to true before returning if the caller should discard the
** contents of the page cache before proceeding. Or, if it returns 
** WAL_RETRY, then the heap memory wal-index has been discarded and 
** the caller should retry opening the read transaction from the 
** beginning (including attempting to map the *-shm file). 
**
** If an error occurs, an SQLite error code is returned.
*/
static int walBeginShmUnreliable(Wal *pWal, int *pChanged){
  i64 szWal;                      /* Size of wal file on disk in bytes */
  i64 iOffset;                    /* Current offset when reading wal file */
  u8 aBuf[WAL_HDRSIZE];           /* Buffer to load WAL header into */
  u8 *aFrame = 0;                 /* Malloc'd buffer to load entire frame */
  int szFrame;                    /* Number of bytes in buffer aFrame[] */
  u8 *aData;                      /* Pointer to data part of aFrame buffer */
  volatile void *pDummy;          /* Dummy argument for xShmMap */
  int rc;                         /* Return code */
  u32 aSaveCksum[2];              /* Saved copy of pWal->hdr.aFrameCksum */

  assert( pWal->bShmUnreliable );
  assert( pWal->readOnly & WAL_SHM_RDONLY );
  assert( pWal->nWiData>0 && pWal->apWiData[0] );

  /* Take WAL_READ_LOCK(0). This has the effect of preventing any
  ** writers from running a checkpoint, but does not stop them
  ** from running recovery.  */
  rc = walLockShared(pWal, WAL_READ_LOCK(0));
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_BUSY ) rc = WAL_RETRY;
    goto begin_unreliable_shm_out;
  }
  pWal->readLock = 0;

  /* Check to see if a separate writer has attached to the shared-memory area,
  ** thus making the shared-memory "reliable" again.  Do this by invoking
  ** the xShmMap() routine of the VFS and looking to see if the return
  ** is SQLITE_READONLY instead of SQLITE_READONLY_CANTINIT.
  **
  ** If the shared-memory is now "reliable" return WAL_RETRY, which will
  ** cause the heap-memory WAL-index to be discarded and the actual
  ** shared memory to be used in its place.
  **
  ** This step is important because, even though this connection is holding
  ** the WAL_READ_LOCK(0) which prevents a checkpoint, a writer might
  ** have already checkpointed the WAL file and, while the current
  ** is active, wrap the WAL and start overwriting frames that this
  ** process wants to use.
  **
  ** Once sqlite3OsShmMap() has been called for an sqlite3_file and has
  ** returned any SQLITE_READONLY value, it must return only SQLITE_READONLY
  ** or SQLITE_READONLY_CANTINIT or some error for all subsequent invocations,
  ** even if some external agent does a "chmod" to make the shared-memory
  ** writable by us, until sqlite3OsShmUnmap() has been called.
  ** This is a requirement on the VFS implementation.
   */
  rc = sqlite3OsShmMap(pWal->pDbFd, 0, WALINDEX_PGSZ, 0, &pDummy);
  assert( rc!=SQLITE_OK ); /* SQLITE_OK not possible for read-only connection */
  if( rc!=SQLITE_READONLY_CANTINIT ){
    rc = (rc==SQLITE_READONLY ? WAL_RETRY : rc);
    goto begin_unreliable_shm_out;
  }

  /* We reach this point only if the real shared-memory is still unreliable.
  ** Assume the in-memory WAL-index substitute is correct and load it
  ** into pWal->hdr.
  */
  memcpy(&pWal->hdr, (void*)walIndexHdr(pWal), sizeof(WalIndexHdr));

  /* Make sure some writer hasn't come in and changed the WAL file out
  ** from under us, then disconnected, while we were not looking.
  */
  rc = sqlite3OsFileSize(pWal->pWalFd, &szWal);
  if( rc!=SQLITE_OK ){
    goto begin_unreliable_shm_out;
  }
  if( szWal<WAL_HDRSIZE ){
    /* If the wal file is too small to contain a wal-header and the
    ** wal-index header has mxFrame==0, then it must be safe to proceed
    ** reading the database file only. However, the page cache cannot
    ** be trusted, as a read/write connection may have connected, written
    ** the db, run a checkpoint, truncated the wal file and disconnected
    ** since this client's last read transaction.  */
    *pChanged = 1;
    rc = (pWal->hdr.mxFrame==0 ? SQLITE_OK : WAL_RETRY);
    goto begin_unreliable_shm_out;
  }

  /* Check the salt keys at the start of the wal file still match. */
  rc = sqlite3OsRead(pWal->pWalFd, aBuf, WAL_HDRSIZE, 0);
  if( rc!=SQLITE_OK ){
    goto begin_unreliable_shm_out;
  }
  if( memcmp(&pWal->hdr.aSalt, &aBuf[16], 8) ){
    /* Some writer has wrapped the WAL file while we were not looking.
    ** Return WAL_RETRY which will cause the in-memory WAL-index to be
    ** rebuilt. */
    rc = WAL_RETRY;
    goto begin_unreliable_shm_out;
  }

  /* Allocate a buffer to read frames into */
  szFrame = pWal->hdr.szPage + WAL_FRAME_HDRSIZE;
  aFrame = (u8 *)sqlite3_malloc64(szFrame);
  if( aFrame==0 ){
    rc = SQLITE_NOMEM_BKPT;
    goto begin_unreliable_shm_out;
  }
  aData = &aFrame[WAL_FRAME_HDRSIZE];

  /* Check to see if a complete transaction has been appended to the
  ** wal file since the heap-memory wal-index was created. If so, the
  ** heap-memory wal-index is discarded and WAL_RETRY returned to
  ** the caller.  */
  aSaveCksum[0] = pWal->hdr.aFrameCksum[0];
  aSaveCksum[1] = pWal->hdr.aFrameCksum[1];
  for(iOffset=walFrameOffset(pWal->hdr.mxFrame+1, pWal->hdr.szPage); 
      iOffset+szFrame<=szWal; 
      iOffset+=szFrame
  ){
    u32 pgno;                   /* Database page number for frame */
    u32 nTruncate;              /* dbsize field from frame header */

    /* Read and decode the next log frame. */
    rc = sqlite3OsRead(pWal->pWalFd, aFrame, szFrame, iOffset);
    if( rc!=SQLITE_OK ) break;
    if( !walDecodeFrame(pWal, &pgno, &nTruncate, aData, aFrame) ) break;

    /* If nTruncate is non-zero, then a complete transaction has been
    ** appended to this wal file. Set rc to WAL_RETRY and break out of
    ** the loop.  */
    if( nTruncate ){
      rc = WAL_RETRY;
      break;
    }
  }
  pWal->hdr.aFrameCksum[0] = aSaveCksum[0];
  pWal->hdr.aFrameCksum[1] = aSaveCksum[1];

 begin_unreliable_shm_out:
  sqlite3_free(aFrame);
  if( rc!=SQLITE_OK ){
    int i;
    for(i=0; i<pWal->nWiData; i++){
      sqlite3_free((void*)pWal->apWiData[i]);
      pWal->apWiData[i] = 0;
    }
    pWal->bShmUnreliable = 0;
    sqlite3WalEndReadTransaction(pWal);
    *pChanged = 1;
  }
  return rc;
}

/*
** Attempt to start a read transaction.  This might fail due to a race or
** other transient condition.  When that happens, it returns WAL_RETRY to
** indicate to the caller that it is safe to retry immediately.
**
** On success return SQLITE_OK.  On a permanent failure (such an
................................................................................
** recovery) return a positive error code.
**
** The useWal parameter is true to force the use of the WAL and disable
** the case where the WAL is bypassed because it has been completely
** checkpointed.  If useWal==0 then this routine calls walIndexReadHdr() 
** to make a copy of the wal-index header into pWal->hdr.  If the 
** wal-index header has changed, *pChanged is set to 1 (as an indication 
** to the caller that the local page cache is obsolete and needs to be 
** flushed.)  When useWal==1, the wal-index header is assumed to already
** be loaded and the pChanged parameter is unused.
**
** The caller must set the cnt parameter to the number of prior calls to
** this routine during the current read attempt that returned WAL_RETRY.
** This routine will start taking more aggressive measures to clear the
** race conditions after multiple WAL_RETRY returns, and after an excessive
................................................................................
  int mxI;                        /* Index of largest aReadMark[] value */
  int i;                          /* Loop counter */
  int rc = SQLITE_OK;             /* Return code  */
  u32 mxFrame;                    /* Wal frame to lock to */

  assert( pWal->readLock<0 );     /* Not currently locked */

  /* useWal may only be set for read/write connections */
  assert( (pWal->readOnly & WAL_SHM_RDONLY)==0 || useWal==0 );

  /* Take steps to avoid spinning forever if there is a protocol error.
  **
  ** Circumstances that cause a RETRY should only last for the briefest
  ** instances of time.  No I/O or other system calls are done while the
  ** locks are held, so the locks should not be held for very long. But 
  ** if we are unlucky, another process that is holding a lock might get
  ** paged out or take a page-fault that is time-consuming to resolve, 
................................................................................
      return SQLITE_PROTOCOL;
    }
    if( cnt>=10 ) nDelay = (cnt-9)*(cnt-9)*39;
    sqlite3OsSleep(pWal->pVfs, nDelay);
  }

  if( !useWal ){
    assert( rc==SQLITE_OK );
    if( pWal->bShmUnreliable==0 ){
      rc = walIndexReadHdr(pWal, pChanged);
    }
    if( rc==SQLITE_BUSY ){
      /* If there is not a recovery running in another thread or process
      ** then convert BUSY errors to WAL_RETRY.  If recovery is known to
      ** be running, convert BUSY to BUSY_RECOVERY.  There is a race here
      ** which might cause WAL_RETRY to be returned even if BUSY_RECOVERY
      ** would be technically correct.  But the race is benign since with
      ** WAL_RETRY this routine will be called again and will probably be
................................................................................
      }else if( rc==SQLITE_BUSY ){
        rc = SQLITE_BUSY_RECOVERY;
      }
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
    else if( pWal->bShmUnreliable ){
      return walBeginShmUnreliable(pWal, pChanged);
    }
  }

  assert( pWal->nWiData>0 );
  assert( pWal->apWiData[0]!=0 );
  pInfo = walCkptInfo(pWal);
  if( !useWal && pInfo->nBackfill==pWal->hdr.mxFrame
#ifdef SQLITE_ENABLE_SNAPSHOT
   && (pWal->pSnapshot==0 || pWal->hdr.mxFrame==0
     || 0==memcmp(&pWal->hdr, pWal->pSnapshot, sizeof(WalIndexHdr)))
#endif
  ){
    /* The WAL has been completely backfilled (or it is empty).
    ** and can be safely ignored.
................................................................................
      }else if( rc!=SQLITE_BUSY ){
        return rc;
      }
    }
  }
  if( mxI==0 ){
    assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
    return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTINIT;
  }

  rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
  if( rc ){
    return rc==SQLITE_BUSY ? WAL_RETRY : rc;
  }
  /* Now that the read-lock has been obtained, check that neither the
................................................................................

  /* If the "last page" field of the wal-index header snapshot is 0, then
  ** no data will be read from the wal under any circumstances. Return early
  ** in this case as an optimization.  Likewise, if pWal->readLock==0, 
  ** then the WAL is ignored by the reader so return early, as if the 
  ** WAL were empty.
  */
  if( iLast==0 || (pWal->readLock==0 && pWal->bShmUnreliable==0) ){
    *piRead = 0;
    return SQLITE_OK;
  }

  /* Search the hash table or tables for an entry matching page number
  ** pgno. Each iteration of the following for() loop searches one
  ** hash table (each hash table indexes up to HASHTABLE_NPAGE frames).
................................................................................
#ifdef SQLITE_ENABLE_EXPENSIVE_ASSERT
  /* If expensive assert() statements are available, do a linear search
  ** of the wal-index file content. Make sure the results agree with the
  ** result obtained using the hash indexes above.  */
  {
    u32 iRead2 = 0;
    u32 iTest;
    assert( pWal->bShmUnreliable || pWal->minFrame>0 );
    for(iTest=iLast; iTest>=pWal->minFrame && iTest>0; iTest--){
      if( walFramePgno(pWal, iTest)==pgno ){
        iRead2 = iTest;
        break;
      }
    }
    assert( iRead==iRead2 );
  }
................................................................................
  ** locks are taken in this case). Nor should the pager attempt to
  ** upgrade to exclusive-mode following such an error.
  */
  assert( pWal->readLock>=0 || pWal->lockError );
  assert( pWal->readLock>=0 || (op<=0 && pWal->exclusiveMode==0) );

  if( op==0 ){
    if( pWal->exclusiveMode!=WAL_NORMAL_MODE ){
      pWal->exclusiveMode = WAL_NORMAL_MODE;
      if( walLockShared(pWal, WAL_READ_LOCK(pWal->readLock))!=SQLITE_OK ){
        pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
      }
      rc = pWal->exclusiveMode==WAL_NORMAL_MODE;
    }else{
      /* Already in locking_mode=NORMAL */
      rc = 0;
    }
  }else if( op>0 ){
    assert( pWal->exclusiveMode==WAL_NORMAL_MODE );
    assert( pWal->readLock>=0 );
    walUnlockShared(pWal, WAL_READ_LOCK(pWal->readLock));
    pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
    rc = 1;
  }else{
    rc = pWal->exclusiveMode==WAL_NORMAL_MODE;
  }
  return rc;
}

/* 
** Return true if the argument is non-NULL and the WAL module is using
** heap-memory for the wal-index. Otherwise, if the argument is NULL or the

int sqlite3WalkSelectExpr(Walker *pWalker, Select *p){
  if( sqlite3WalkExprList(pWalker, p->pEList) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pWhere) ) return WRC_Abort;
  if( sqlite3WalkExprList(pWalker, p->pGroupBy) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pHaving) ) return WRC_Abort;
  if( sqlite3WalkExprList(pWalker, p->pOrderBy) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pLimit) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pOffset) ) return WRC_Abort;
  return WRC_Continue;
}

/*
** Walk the parse trees associated with all subqueries in the
** FROM clause of SELECT statement p.  Do not invoke the select
** callback on p, but do invoke it on each FROM clause subquery
................................................................................
*/
int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
  SrcList *pSrc;
  int i;
  struct SrcList_item *pItem;

  pSrc = p->pSrc;
  if( ALWAYS(pSrc) ){
    for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
      if( pItem->pSelect && sqlite3WalkSelect(pWalker, pItem->pSelect) ){
        return WRC_Abort;
      }
      if( pItem->fg.isTabFunc
       && sqlite3WalkExprList(pWalker, pItem->u1.pFuncArg)
      ){
        return WRC_Abort;
      }
    }
  }
  return WRC_Continue;
} 

/*
** Call sqlite3WalkExpr() for every expression in Select statement p.

int sqlite3WalkSelectExpr(Walker *pWalker, Select *p){
  if( sqlite3WalkExprList(pWalker, p->pEList) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pWhere) ) return WRC_Abort;
  if( sqlite3WalkExprList(pWalker, p->pGroupBy) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pHaving) ) return WRC_Abort;
  if( sqlite3WalkExprList(pWalker, p->pOrderBy) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pLimit) ) return WRC_Abort;

  return WRC_Continue;
}

/*
** Walk the parse trees associated with all subqueries in the
** FROM clause of SELECT statement p.  Do not invoke the select
** callback on p, but do invoke it on each FROM clause subquery
................................................................................
*/
int sqlite3WalkSelectFrom(Walker *pWalker, Select *p){
  SrcList *pSrc;
  int i;
  struct SrcList_item *pItem;

  pSrc = p->pSrc;
  assert( pSrc!=0 );
  for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
    if( pItem->pSelect && sqlite3WalkSelect(pWalker, pItem->pSelect) ){
      return WRC_Abort;
    }
    if( pItem->fg.isTabFunc
     && sqlite3WalkExprList(pWalker, pItem->u1.pFuncArg)
    ){
      return WRC_Abort;

    }
  }
  return WRC_Continue;
} 

/*
** Call sqlite3WalkExpr() for every expression in Select statement p.

  sqlite3DbFreeNN(db, p);
}

/*
** Free a WhereInfo structure
*/
static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
  if( ALWAYS(pWInfo) ){
    int i;

    for(i=0; i<pWInfo->nLevel; i++){
      WhereLevel *pLevel = &pWInfo->a[i];
      if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){
        sqlite3DbFree(db, pLevel->u.in.aInLoop);
      }
    }
    sqlite3WhereClauseClear(&pWInfo->sWC);
    while( pWInfo->pLoops ){
      WhereLoop *p = pWInfo->pLoops;
      pWInfo->pLoops = p->pNextLoop;
      whereLoopDelete(db, p);
    }
    sqlite3DbFreeNN(db, pWInfo);
  }
}

/*
** Return TRUE if all of the following are true:
**
**   (1)  X has the same or lower cost that Y
**   (2)  X uses fewer WHERE clause terms than Y
................................................................................
        pNew->prereq = mPrereq | pTerm->prereqRight;
        rc = whereLoopInsert(pBuilder, pNew);
      }
    }
  }
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

  /* Loop over all indices
  */
  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){


    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }
    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
................................................................................
      pTab->tabFlags |= TF_StatsUsed;
    }
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3Stat4ProbeFree(pBuilder->pRec);
    pBuilder->nRecValid = 0;
    pBuilder->pRec = 0;
#endif

    /* If there was an INDEXED BY clause, then only that one index is
    ** considered. */
    if( pSrc->pIBIndex ) break;
  }
  return rc;
}

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*

  sqlite3DbFreeNN(db, p);
}

/*
** Free a WhereInfo structure
*/
static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){

  int i;
  assert( pWInfo!=0 );
  for(i=0; i<pWInfo->nLevel; i++){
    WhereLevel *pLevel = &pWInfo->a[i];
    if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){
      sqlite3DbFree(db, pLevel->u.in.aInLoop);
    }
  }
  sqlite3WhereClauseClear(&pWInfo->sWC);
  while( pWInfo->pLoops ){
    WhereLoop *p = pWInfo->pLoops;
    pWInfo->pLoops = p->pNextLoop;
    whereLoopDelete(db, p);
  }
  sqlite3DbFreeNN(db, pWInfo);

}

/*
** Return TRUE if all of the following are true:
**
**   (1)  X has the same or lower cost that Y
**   (2)  X uses fewer WHERE clause terms than Y
................................................................................
        pNew->prereq = mPrereq | pTerm->prereqRight;
        rc = whereLoopInsert(pBuilder, pNew);
      }
    }
  }
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */

  /* Loop over all indices. If there was an INDEXED BY clause, then only 
  ** consider index pProbe.  */
  for(; rc==SQLITE_OK && pProbe; 
      pProbe=(pSrc->pIBIndex ? 0 : pProbe->pNext), iSortIdx++
  ){
    if( pProbe->pPartIdxWhere!=0
     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
      continue;  /* Partial index inappropriate for this query */
    }
    rSize = pProbe->aiRowLogEst[0];
    pNew->u.btree.nEq = 0;
................................................................................
      pTab->tabFlags |= TF_StatsUsed;
    }
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
    sqlite3Stat4ProbeFree(pBuilder->pRec);
    pBuilder->nRecValid = 0;
    pBuilder->pRec = 0;
#endif




  }
  return rc;
}

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*

** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
** The TERM_LIKECOND marking indicates that the term should be coded inside
** a conditional such that is only evaluated on the second pass of a
** LIKE-optimization loop, when scanning BLOBs instead of strings.
*/
static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
  int nLoop = 0;
  while( ALWAYS(pTerm!=0)
      && (pTerm->wtFlags & TERM_CODED)==0
      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
      && (pLevel->notReady & pTerm->prereqAll)==0
  ){
    if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
      pTerm->wtFlags |= TERM_LIKECOND;
    }else{
      pTerm->wtFlags |= TERM_CODED;
    }
    if( pTerm->iParent<0 ) break;
    pTerm = &pTerm->pWC->a[pTerm->iParent];

    pTerm->nChild--;
    if( pTerm->nChild!=0 ) break;
    nLoop++;
  }
}

/*

** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
** The TERM_LIKECOND marking indicates that the term should be coded inside
** a conditional such that is only evaluated on the second pass of a
** LIKE-optimization loop, when scanning BLOBs instead of strings.
*/
static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
  int nLoop = 0;
  assert( pTerm!=0 );
  while( (pTerm->wtFlags & TERM_CODED)==0
      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
      && (pLevel->notReady & pTerm->prereqAll)==0
  ){
    if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
      pTerm->wtFlags |= TERM_LIKECOND;
    }else{
      pTerm->wtFlags |= TERM_CODED;
    }
    if( pTerm->iParent<0 ) break;
    pTerm = &pTerm->pWC->a[pTerm->iParent];
    assert( pTerm!=0 );
    pTerm->nChild--;
    if( pTerm->nChild!=0 ) break;
    nLoop++;
  }
}

/*

  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
  int noCase = 0;                  /* uppercase equivalent to lowercase */
  int op;                          /* Top-level operator.  pExpr->op */
  Parse *pParse = pWInfo->pParse;  /* Parsing context */
  sqlite3 *db = pParse->db;        /* Database connection */
  unsigned char eOp2;              /* op2 value for LIKE/REGEXP/GLOB */
  int nLeft;                       /* Number of elements on left side vector */

  if( db->mallocFailed ){
    return;
  }
  pTerm = &pWC->a[idxTerm];
  pMaskSet = &pWInfo->sMaskSet;
................................................................................
  ** not normally optimized for ordinary tables.  In other words, OP
  ** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL.
  ** This information is used by the xBestIndex methods of
  ** virtual tables.  The native query optimizer does not attempt
  ** to do anything with MATCH functions.
  */
  if( pWC->op==TK_AND ){
    Expr *pRight, *pLeft;
    int res = isAuxiliaryVtabOperator(pExpr, &eOp2, &pLeft, &pRight);
    while( res-- > 0 ){
      int idxNew;
      WhereTerm *pNewTerm;
      Bitmask prereqColumn, prereqExpr;

      prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);

  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
  int noCase = 0;                  /* uppercase equivalent to lowercase */
  int op;                          /* Top-level operator.  pExpr->op */
  Parse *pParse = pWInfo->pParse;  /* Parsing context */
  sqlite3 *db = pParse->db;        /* Database connection */
  unsigned char eOp2 = 0;          /* op2 value for LIKE/REGEXP/GLOB */
  int nLeft;                       /* Number of elements on left side vector */

  if( db->mallocFailed ){
    return;
  }
  pTerm = &pWC->a[idxTerm];
  pMaskSet = &pWInfo->sMaskSet;
................................................................................
  ** not normally optimized for ordinary tables.  In other words, OP
  ** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL.
  ** This information is used by the xBestIndex methods of
  ** virtual tables.  The native query optimizer does not attempt
  ** to do anything with MATCH functions.
  */
  if( pWC->op==TK_AND ){
    Expr *pRight = 0, *pLeft = 0;
    int res = isAuxiliaryVtabOperator(pExpr, &eOp2, &pLeft, &pRight);
    while( res-- > 0 ){
      int idxNew;
      WhereTerm *pNewTerm;
      Bitmask prereqColumn, prereqExpr;

      prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);

# 2017-10-11
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the checkfreelist extension.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix checkfreelist

ifcapable !vtab||!compound {
  finish_test
  return
}

if {[file exists ../checkfreelist.so]==0} {
  finish_test
  return
}

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
}

db enable_load_extension 1
do_execsql_test 1.1 {
  SELECT load_extension('../checkfreelist.so');
} {{}}

do_execsql_test 1.2 { SELECT checkfreelist('main') } {ok}
do_execsql_test 1.3 {
  WITH s(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10000
  )
  INSERT INTO t1 SELECT randomblob(400), randomblob(400) FROM s;
  DELETE FROM t1 WHERE rowid%3;
  PRAGMA freelist_count;
} {6726}

do_execsql_test 1.4 { SELECT checkfreelist('main') } {ok}
do_execsql_test 1.5 {
  WITH freelist_trunk(i, d, n) AS (
    SELECT 1, NULL, sqlite_readint32(data, 32) FROM sqlite_dbpage WHERE pgno=1
      UNION ALL
    SELECT n, data, sqlite_readint32(data) 
    FROM freelist_trunk, sqlite_dbpage WHERE pgno=n
  )
  SELECT i FROM freelist_trunk WHERE i!=1;
} {
  10010 9716 9344 8970 8596 8223 7848 7475 7103 6728 6355 5983 5609 5235
  4861 4488 4113 3741 3368 2993 2620 2248 1873 1500 1126 753 378 5
}

do_execsql_test 1.6 { SELECT checkfreelist('main') } {ok}

proc set_int {blob idx newval} {
  binary scan $blob I* ints
  lset ints $idx $newval
  binary format I* $ints
}
db func set_int set_int

proc get_int {blob idx} {
  binary scan $blob I* ints
  lindex $ints $idx
}
db func get_int get_int

do_execsql_test 1.7 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 1, get_int(data, 1)-1) 
      WHERE pgno=4861;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{free-list count mismatch: actual=6725 header=6726}}

do_execsql_test 1.8 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 5, (SELECT * FROM pragma_page_count)+1)
      WHERE pgno=4861;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 10093 is out of range (child 3 of trunk page 4861)}}

do_execsql_test 1.9 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 5, 0)
      WHERE pgno=4861;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 0 is out of range (child 3 of trunk page 4861)}}

do_execsql_test 1.10 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, get_int(data, 1)+1, 0)
      WHERE pgno=5;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf page 0 is out of range (child 247 of trunk page 5)}}

do_execsql_test 1.11 {
  BEGIN;
    UPDATE sqlite_dbpage 
      SET data = set_int(data, 1, 249)
      WHERE pgno=5;
    SELECT checkfreelist('main');
  ROLLBACK;
} {{leaf count out of range (249) on trunk page 5}}

finish_test

do_catchsql_test 2.3 {
  INSERT INTO t1 VALUES(randomblob(900));
} {1 {database disk image is malformed}}

#-------------------------------------------------------------------------




proc hex2blob {hex} {
  # Split on newlines:
  set bytes [list]
  foreach l [split $hex "\n"] {
    if {[string is space $l]} continue
    set L [list]
    foreach b [split $l] {
      if {[string is xdigit $b] && [string length $b]==2} { 
        lappend L [expr "0x$b"]
      }
    }
    if {[llength $L]!=16} {
      error "Badly formed hex (1)"
    }
    set bytes [concat $bytes $L]
  }

  binary format c* $bytes
}

reset_db
db func hex2blob hex2blob

do_execsql_test 3.1 {
  PRAGMA page_size=1024;
  CREATE TABLE t1(a, b, c);
  CREATE TABLE t2(a, b, c);
  CREATE TABLE t3(a, b, c);
  CREATE TABLE t4(a, b, c);
  CREATE TABLE t5(a, b, c);
}

do_execsql_test 3.2 {
  UPDATE sqlite_dbpage SET data = hex2blob('
 000: 53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00 SQLite format 3.
 010: 04 00 01 01 20 40 20 20 00 00 3e d9 00 00 00 06 .... @  ..>.....
 020: 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 04 ................
 030: 0f 00 00 00 00 00 00 00 00 00 00 01 00 00 83 00 ................
 040: 00 00 00 00 00 00 00 00 00 00 00 00 00 38 00 00 .............8..
 050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3e d9 ..............>.
 060: 00 2d e6 07 0d 00 00 00 01 03 a0 00 03 e0 00 00 .-..............
 070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 0a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 0b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 0c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 0d0: 00 00 00 00 00 c1 00 00 00 00 00 00 00 00 00 00 ................
 0e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 0f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 160: 00 83 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 180: 00 00 00 00 00 00 00 00 00 00 07 00 30 00 00 00 ............0...
 190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 1a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 1b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 1c0: 02 00 00 00 00 00 00 00 00 00 00 02 00 00 00 00 ................
 1d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 1e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 1f0: 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 220: 00 00 0e 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 230: 0c 00 00 00 00 00 00 60 00 00 00 06 00 00 c3 00 .......`........
 240: 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 250: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 260: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 270: 00 00 00 18 00 00 00 00 00 00 00 00 00 00 00 00 ................
 280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 290: 04 00 0e 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 2a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 2b0: 00 00 00 00 83 00 8c 00 00 00 00 00 00 00 00 00 ................
 2c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 2d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 2e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 2f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 310: 00 78 00 00 00 00 00 00 00 00 00 00 00 00 70 00 .x............p.
 320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 330: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 340: 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 00 ................
 350: 00 00 00 00 00 68 00 00 00 00 00 00 00 00 00 00 .....h..........
 360: 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 ................
 370: 00 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00 ................
 380: 00 00 00 00 70 00 00 00 00 00 00 00 00 00 00 00 ....p...........
 390: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 3a0: 5e 01 07 17 1b 1b 01 81 13 74 61 62 6c 65 73 65 ^........tablese
 3b0: 6e 73 6f 32 73 73 65 6e 73 6f 72 73 02 43 52 45 nso2ssensors.CRE
 3c0: 41 54 45 20 54 41 42 4c 45 20 73 65 6e 73 6f 72 ATE TABLE sensor
 3d0: 73 20 0a 20 20 24 20 20 20 20 20 20 20 20 20 20 s .  $          
 3e0: b8 6e 61 6d 65 21 74 65 78 74 2c 20 79 61 6c 20 .name!text, yal 
 3f0: 72 65 61 6c 2c 20 74 69 6d 65 20 74 65 78 74 29 real, time text)
  ') WHERE pgno=1
}

db close
sqlite3 db test.db

do_catchsql_test 3.3 {
  PRAGMA integrity_check;
} {1 {database disk image is malformed}}






finish_test

do_catchsql_test 2.3 {
  INSERT INTO t1 VALUES(randomblob(900));
} {1 {database disk image is malformed}}

#-------------------------------------------------------------------------

ifcapable vtab {
if {[permutation]!="inmemory_journal"} {

  proc hex2blob {hex} {
    # Split on newlines:
    set bytes [list]
    foreach l [split $hex "\n"] {
      if {[string is space $l]} continue
      set L [list]
      foreach b [split $l] {
        if {[string is xdigit $b] && [string length $b]==2} { 
          lappend L [expr "0x$b"]
        }
      }
      if {[llength $L]!=16} {
        error "Badly formed hex (1)"
      }
      set bytes [concat $bytes $L]
    }
  
    binary format c* $bytes
  }
  
  reset_db
  db func hex2blob hex2blob
  
  do_execsql_test 3.1 {
    PRAGMA page_size=1024;
    CREATE TABLE t1(a, b, c);
    CREATE TABLE t2(a, b, c);
    CREATE TABLE t3(a, b, c);
    CREATE TABLE t4(a, b, c);
    CREATE TABLE t5(a, b, c);
  }
  
  do_execsql_test 3.2 {
    UPDATE sqlite_dbpage SET data = hex2blob('
   000: 53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00 SQLite format 3.
   010: 04 00 01 01 20 40 20 20 00 00 3e d9 00 00 00 06 .... @  ..>.....
   020: 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 04 ................
   030: 0f 00 00 00 00 00 00 00 00 00 00 01 00 00 83 00 ................
   040: 00 00 00 00 00 00 00 00 00 00 00 00 00 38 00 00 .............8..
   050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3e d9 ..............>.
   060: 00 2d e6 07 0d 00 00 00 01 03 a0 00 03 e0 00 00 .-..............
   070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   0a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   0b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   0c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   0d0: 00 00 00 00 00 c1 00 00 00 00 00 00 00 00 00 00 ................
   0e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   0f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   130: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   160: 00 83 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   180: 00 00 00 00 00 00 00 00 00 00 07 00 30 00 00 00 ............0...
   190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   1a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   1b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   1c0: 02 00 00 00 00 00 00 00 00 00 00 02 00 00 00 00 ................
   1d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   1e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   1f0: 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   210: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   220: 00 00 0e 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   230: 0c 00 00 00 00 00 00 60 00 00 00 06 00 00 c3 00 .......`........
   240: 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   250: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   260: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   270: 00 00 00 18 00 00 00 00 00 00 00 00 00 00 00 00 ................
   280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   290: 04 00 0e 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   2a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   2b0: 00 00 00 00 83 00 8c 00 00 00 00 00 00 00 00 00 ................
   2c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   2d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   2e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   2f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   310: 00 78 00 00 00 00 00 00 00 00 00 00 00 00 70 00 .x............p.
   320: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   330: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   340: 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 00 ................
   350: 00 00 00 00 00 68 00 00 00 00 00 00 00 00 00 00 .....h..........
   360: 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 ................
   370: 00 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00 ................
   380: 00 00 00 00 70 00 00 00 00 00 00 00 00 00 00 00 ....p...........
   390: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
   3a0: 5e 01 07 17 1b 1b 01 81 13 74 61 62 6c 65 73 65 ^........tablese
   3b0: 6e 73 6f 32 73 73 65 6e 73 6f 72 73 02 43 52 45 nso2ssensors.CRE
   3c0: 41 54 45 20 54 41 42 4c 45 20 73 65 6e 73 6f 72 ATE TABLE sensor
   3d0: 73 20 0a 20 20 24 20 20 20 20 20 20 20 20 20 20 s .  $          
   3e0: b8 6e 61 6d 65 21 74 65 78 74 2c 20 79 61 6c 20 .name!text, yal 
   3f0: 72 65 61 6c 2c 20 74 69 6d 65 20 74 65 78 74 29 real, time text)
    ') WHERE pgno=1
  }
  
  db close
  sqlite3 db test.db
  
  do_catchsql_test 3.3 {
    PRAGMA integrity_check;
  } {1 {database disk image is malformed}}

} ;# [permutation]!="inmemory_journal"
} ;# ifcapable vtab



finish_test

set testprefix dbpage

ifcapable !vtab||!compound {
  finish_test
  return
}

do_execsql_test 100 {


  PRAGMA page_size=4096;
  PRAGMA journal_mode=WAL;


  CREATE TABLE t1(a,b);
  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100)
  INSERT INTO t1(a,b) SELECT x, printf('%d-x%.*c',x,x,'x') FROM c;
  PRAGMA integrity_check;

} {wal ok}
do_execsql_test 110 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage('main') ORDER BY pgno;
} {1 X'53514C6974' 2 X'0500000001' 3 X'0D0000004E' 4 X'0D00000016'}
do_execsql_test 120 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage WHERE pgno=2;
} {2 X'0500000001'}
do_execsql_test 130 {
................................................................................
} {4 X'0D00000016'}
do_execsql_test 140 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage WHERE pgno=5;
} {}
do_execsql_test 150 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage WHERE pgno=0;
} {}
















do_execsql_test 200 {
  CREATE TEMP TABLE saved_content(x);
  INSERT INTO saved_content(x) SELECT data FROM sqlite_dbpage WHERE pgno=4;
  UPDATE sqlite_dbpage SET data=zeroblob(4096) WHERE pgno=4;
} {}
do_catchsql_test 210 {
................................................................................
} {1 X'53514C6974' 2 X'0500000001' 3 X'0D0000004E' 4 X'0000000000'}
do_execsql_test 230 {
  UPDATE sqlite_dbpage SET data=(SELECT x FROM saved_content) WHERE pgno=4;
} {}
do_catchsql_test 230 {
  PRAGMA integrity_check;
} {0 ok}






















finish_test

set testprefix dbpage

ifcapable !vtab||!compound {
  finish_test
  return
}

do_test 100 {
  execsql {
    PRAGMA auto_vacuum=0;
    PRAGMA page_size=4096;
    PRAGMA journal_mode=WAL;
  }
  execsql { 
    CREATE TABLE t1(a,b);
    WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100)
      INSERT INTO t1(a,b) SELECT x, printf('%d-x%.*c',x,x,'x') FROM c;
    PRAGMA integrity_check;
  }
} {ok}
do_execsql_test 110 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage('main') ORDER BY pgno;
} {1 X'53514C6974' 2 X'0500000001' 3 X'0D0000004E' 4 X'0D00000016'}
do_execsql_test 120 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage WHERE pgno=2;
} {2 X'0500000001'}
do_execsql_test 130 {
................................................................................
} {4 X'0D00000016'}
do_execsql_test 140 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage WHERE pgno=5;
} {}
do_execsql_test 150 {
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage WHERE pgno=0;
} {}
do_execsql_test 160 {
  ATTACH ':memory:' AS aux1;
  PRAGMA aux1.page_size=4096;
  CREATE TABLE aux1.t2(a,b,c);
  INSERT INTO t2 VALUES(11,12,13);
  SELECT pgno, quote(substr(data,1,5)) FROM sqlite_dbpage('aux1');
} {1 X'53514C6974' 2 X'0D00000001'}
do_execsql_test 170 {
  CREATE TABLE aux1.x3(x,y,z);
  INSERT INTO x3(x,y,z) VALUES(1,'main',1),(2,'aux1',1);
  SELECT pgno, schema, substr(data,1,6)
    FROM sqlite_dbpage, x3
   WHERE sqlite_dbpage.schema=x3.y AND sqlite_dbpage.pgno=x3.z
   ORDER BY x3.x;
} {1 main SQLite 1 aux1 SQLite}

do_execsql_test 200 {
  CREATE TEMP TABLE saved_content(x);
  INSERT INTO saved_content(x) SELECT data FROM sqlite_dbpage WHERE pgno=4;
  UPDATE sqlite_dbpage SET data=zeroblob(4096) WHERE pgno=4;
} {}
do_catchsql_test 210 {
................................................................................
} {1 X'53514C6974' 2 X'0500000001' 3 X'0D0000004E' 4 X'0000000000'}
do_execsql_test 230 {
  UPDATE sqlite_dbpage SET data=(SELECT x FROM saved_content) WHERE pgno=4;
} {}
do_catchsql_test 230 {
  PRAGMA integrity_check;
} {0 ok}
do_execsql_test 240 {
  DELETE FROM saved_content;
  INSERT INTO saved_content(x) 
     SELECT data FROM sqlite_dbpage WHERE schema='aux1' AND pgno=2;
} {}
do_execsql_test 241 {
  UPDATE sqlite_dbpage SET data=zeroblob(4096) WHERE pgno=2 AND schema='aux1';
} {}
do_catchsql_test 250 {
  PRAGMA aux1.integrity_check;
} {1 {database disk image is malformed}}
do_execsql_test 260 {
  UPDATE sqlite_dbpage SET data=(SELECT x FROM saved_content)
   WHERE pgno=2 AND schema='aux1';
} {}
do_catchsql_test 270 {
  PRAGMA aux1.integrity_check;
} {0 ok}




finish_test

} {1 1 3}
do_execsql_test 11.9 {
  SELECT a,b,c FROM x2 INDEXED BY x2i WHERE a=1 AND b=1 AND c='3.0';
} {1 1 3}
do_eqp_test 11.10 {
  SELECT a,b,c FROM x2 INDEXED BY x2i WHERE a=1 AND b=1 AND c='3.0';
} {0 0 0 {SEARCH TABLE x2 USING COVERING INDEX x2i (a=? AND b=? AND rowid=?)}}






















finish_test

} {1 1 3}
do_execsql_test 11.9 {
  SELECT a,b,c FROM x2 INDEXED BY x2i WHERE a=1 AND b=1 AND c='3.0';
} {1 1 3}
do_eqp_test 11.10 {
  SELECT a,b,c FROM x2 INDEXED BY x2i WHERE a=1 AND b=1 AND c='3.0';
} {0 0 0 {SEARCH TABLE x2 USING COVERING INDEX x2i (a=? AND b=? AND rowid=?)}}

#-------------------------------------------------------------------------
# Check INDEXED BY works (throws an exception) with partial indexes that 
# cannot be used.
do_execsql_test 12.1 {
  CREATE TABLE o1(x INTEGER PRIMARY KEY, y, z);
  CREATE INDEX p1 ON o1(z);
  CREATE INDEX p2 ON o1(y) WHERE z=1;
}
do_catchsql_test 12.2 {
  SELECT * FROM o1 INDEXED BY p2 ORDER BY 1;
} {1 {no query solution}}
do_execsql_test 12.3 {
  DROP INDEX p1;
  DROP INDEX p2;
  CREATE INDEX p2 ON o1(y) WHERE z=1;
  CREATE INDEX p1 ON o1(z);
}
do_catchsql_test 12.4 {
  SELECT * FROM o1 INDEXED BY p2 ORDER BY 1;
} {1 {no query solution}}

finish_test

  /* } */
} {1}
do_execsql_test json-11.3 {
  /* Too deep by one { */
  SELECT json_valid(replace(printf('%.2001c0%.2001c','[','}'),'[','{"a":'));
  /* } */
} {0}









































finish_test

  /* } */
} {1}
do_execsql_test json-11.3 {
  /* Too deep by one { */
  SELECT json_valid(replace(printf('%.2001c0%.2001c','[','}'),'[','{"a":'));
  /* } */
} {0}

# 2017-10-27.  Demonstrate the ability to access an element from
# a json structure even though the element name constains a "."
# character, by quoting the element name in the path.
#
do_execsql_test json-12.100 {
  CREATE TABLE t12(x);
  INSERT INTO t12(x) VALUES(
    '{"settings":
        {"layer2":
           {"hapax.legomenon":
              {"forceDisplay":true,
               "transliterate":true,
               "add.footnote":true,
               "summary.report":true},
            "dis.legomenon":
              {"forceDisplay":true,
               "transliterate":false,
               "add.footnote":false,
               "summary.report":true},
            "tris.legomenon":
              {"forceDisplay":true,
               "transliterate":false,
               "add.footnote":false,
               "summary.report":false}
           }
        }
     }');
} {}
do_execsql_test json-12.110 {
  SELECT json_remove(x, '$.settings.layer2."dis.legomenon".forceDisplay')
    FROM t12;
} {{{"settings":{"layer2":{"hapax.legomenon":{"forceDisplay":true,"transliterate":true,"add.footnote":true,"summary.report":true},"dis.legomenon":{"transliterate":false,"add.footnote":false,"summary.report":true},"tris.legomenon":{"forceDisplay":true,"transliterate":false,"add.footnote":false,"summary.report":false}}}}}}
do_execsql_test json-12.120 {
  SELECT json_extract(x, '$.settings.layer2."tris.legomenon"."summary.report"')
    FROM t12;
} {0}




finish_test

}
do_test minmax2-10.12 {
  execsql {
    SELECT min(x), max(x) FROM t6;
  }
} {{} {}}




































finish_test

}
do_test minmax2-10.12 {
  execsql {
    SELECT min(x), max(x) FROM t6;
  }
} {{} {}}

# 2017-10-26.  Extend the min/max optimization to indexes on expressions
#
do_execsql_test minmax2-11.100 {
  CREATE TABLE t11(a,b,c);
  INSERT INTO t11(a,b,c) VALUES(1,10,5),(2,8,11),(3,1,4),(4,20,1),(5,16,4);
  CREATE INDEX t11bc ON t11(b+c);
  SELECT max(b+c) FROM t11;
} {21}
do_execsql_test minmax2-11.110 {
  SELECT a, max(b+c) FROM t11;
} {4 21}
do_test minmax2-11.111 {
  db eval {SELECT max(b+c) FROM t11}
  db status step
} {0}
do_test minmax2-11.112 {
  db eval {SELECT max(c+b) FROM t11}
  db status step
} {4}
do_execsql_test minmax2-11.120 {
  SELECT a, min(b+c) FROM t11;
} {3 5}
do_test minmax2-11.121 {
  db eval {SELECT min(b+c) FROM t11}
  db status step
} {0}
do_test minmax2-11.122 {
  db eval {SELECT min(c+b) FROM t11}
  db status step
} {4}
do_execsql_test minmax2-11.130 {
  INSERT INTO t11(a,b,c) VALUES(6,NULL,0),(7,0,NULL);
  SELECT a, min(b+c) FROM t11;
} {3 5}

finish_test

  }
  db2 eval {
    PRAGMA foreign_key_list(t2);
  }
} {0 0 t1 y {} {NO ACTION} {NO ACTION} NONE}
db2 close


reset_db
do_execsql_test 24.0 {
  PRAGMA page_size = 1024;
  CREATE TABLE t1(a, b, c);
  CREATE INDEX i1 ON t1(b);
  INSERT INTO t1 VALUES('a', 'b', 'c');
  PRAGMA integrity_check;
} {ok}

set r [db one {SELECT rootpage FROM sqlite_master WHERE name = 't1'}]
db close
hexio_write test.db [expr $r*1024 - 16] 000000000000000701040f0f1f616263

sqlite3 db test.db
do_catchsql_test 24.1 {
  SELECT * FROM t1;
} {1 {database disk image is malformed}}
do_catchsql_test 24.2 {
  PRAGMA integrity_check;
} {0 {{database disk image is malformed}}}

database_never_corrupt
finish_test

  }
  db2 eval {
    PRAGMA foreign_key_list(t2);
  }
} {0 0 t1 y {} {NO ACTION} {NO ACTION} NONE}
db2 close

ifcapable !has_codec {
  reset_db
  do_execsql_test 24.0 {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(a, b, c);
    CREATE INDEX i1 ON t1(b);
    INSERT INTO t1 VALUES('a', 'b', 'c');
    PRAGMA integrity_check;
  } {ok}
  
  set r [db one {SELECT rootpage FROM sqlite_master WHERE name = 't1'}]
  db close
  hexio_write test.db [expr $r*1024 - 16] 000000000000000701040f0f1f616263
  
  sqlite3 db test.db
  do_catchsql_test 24.1 {
    SELECT * FROM t1;
  } {1 {database disk image is malformed}}
  do_catchsql_test 24.2 {
    PRAGMA integrity_check;
  } {0 {{database disk image is malformed}}}
}  
database_never_corrupt
finish_test

# names, white-space, and formatting of the CREATE TABLE statement should
# produce identical table content.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix schema6


# Command:   check_same_database_content TESTNAME SQL1 SQL2 SQL3 ...
#
# This command creates fresh databases using SQL1 and subsequent arguments
# and checks to make sure the content of all database files is byte-for-byte
# identical.  Page 1 of the database files is allowed to be different, since
# page 1 contains the sqlite_master table which is expected to vary.

# names, white-space, and formatting of the CREATE TABLE statement should
# produce identical table content.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set ::testprefix schema6
do_not_use_codec

# Command:   check_same_database_content TESTNAME SQL1 SQL2 SQL3 ...
#
# This command creates fresh databases using SQL1 and subsequent arguments
# and checks to make sure the content of all database files is byte-for-byte
# identical.  Page 1 of the database files is allowed to be different, since
# page 1 contains the sqlite_master table which is expected to vary.

# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab


ifcapable !vtab {
  finish_test
  return
}

load_static_extension db unionvtab
................................................................................
} {}

do_catchsql_test 3.3.2 { SELECT * FROM xyz } {1 {fetch_db error!}}



finish_test

# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab
do_not_use_codec

ifcapable !vtab {
  finish_test
  return
}

load_static_extension db unionvtab
................................................................................
} {}

do_catchsql_test 3.3.2 { SELECT * FROM xyz } {1 {fetch_db error!}}



finish_test

# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab


ifcapable !vtab {
  finish_test
  return
}

# This file implements regression tests for SQLite library.  The
# focus of this file is the "swarmvtab" extension
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix swarmvtab
do_not_use_codec

ifcapable !vtab {
  finish_test
  return
}

  finish_test
  return
}

proc fetch_db {file} {
  forcedelete $file
  sqlite3 dbX $file

  dbX eval { CREATE TABLE t1(a INTEGER PRIMARY KEY, b) }

  dbX close

}

forcedelete test.db1


do_execsql_test 1.0 {
  ATTACH 'test.db1' AS aux;
  CREATE TABLE aux.t1(a INTEGER PRIMARY KEY, b);
  INSERT INTO aux.t1 VALUES(1, NULL);
  INSERT INTO aux.t1 VALUES(2, NULL);
  INSERT INTO aux.t1 VALUES(9, NULL);
  DETACH aux;

  finish_test
  return
}

proc fetch_db {file} {
  forcedelete $file
  sqlite3 dbX $file
  set rc [catch {
    dbX eval { CREATE TABLE t1(a INTEGER PRIMARY KEY, b) }
  } res]
  dbX close
  if {$rc!=0} {error $res}
}

forcedelete test.db1
forcedelete test.db2

do_execsql_test 1.0 {
  ATTACH 'test.db1' AS aux;
  CREATE TABLE aux.t1(a INTEGER PRIMARY KEY, b);
  INSERT INTO aux.t1 VALUES(1, NULL);
  INSERT INTO aux.t1 VALUES(2, NULL);
  INSERT INTO aux.t1 VALUES(9, NULL);
  DETACH aux;

  }
} {4 10}
do_test wal2-1.1 {
  execsql { SELECT count(a), sum(a) FROM t1 } db2
} {4 10}

set RECOVER [list                                      \
  {0 1 lock exclusive}   {1 7 lock exclusive}          \
  {1 7 unlock exclusive} {0 1 unlock exclusive}        \
]
set READ [list                                         \
  {4 1 lock shared}    {4 1 unlock shared}             \
]
set INITSLOT [list                                     \
  {4 1 lock exclusive} {4 1 unlock exclusive}          \
]
................................................................................
# UPDATE: This has now changed. When running a checkpoint, if recovery is
# required the client grabs all exclusive locks (just as it would for a
# recovery performed as a pre-cursor to a normal database transaction).
#
set expected_locks [list]
lappend expected_locks {1 1 lock exclusive}   ;# Lock checkpoint
lappend expected_locks {0 1 lock exclusive}   ;# Lock writer
lappend expected_locks {2 6 lock exclusive}   ;# Lock recovery & all aReadMark[]

lappend expected_locks {2 6 unlock exclusive} ;# Unlock recovery & aReadMark[]

lappend expected_locks {0 1 unlock exclusive} ;# Unlock writer
lappend expected_locks {3 1 lock exclusive}   ;# Lock aReadMark[0]
lappend expected_locks {3 1 unlock exclusive} ;# Unlock aReadMark[0]
lappend expected_locks {1 1 unlock exclusive} ;# Unlock checkpoint
do_test wal2-5.1 {
  proc tvfs_cb {method args} {
    set ::shm_file [lindex $args 0]
................................................................................
  testvfs tvfs
  tvfs script tvfs_cb
  sqlite3 db test.db -vfs tvfs
  set {} {}
} {}

set RECOVERY {
  {0 1 lock exclusive} {1 7 lock exclusive} 
  {1 7 unlock exclusive} {0 1 unlock exclusive}
}
set READMARK0_READ {
  {3 1 lock shared} {3 1 unlock shared}
}
set READMARK0_WRITE {
  {3 1 lock shared} 
  {0 1 lock exclusive} {3 1 unlock shared} 
................................................................................
    list [file exists test.db-shm] [file exists test.db-wal]
  } {1 1}
  faultsim_save_and_close

  foreach {tn db_perm wal_perm shm_perm can_open can_read can_write} {
    2   00644   00644   00644   1   1   1
    3   00644   00400   00644   1   1   0
    4   00644   00644   00400   1   0   0
    5   00400   00644   00644   1   1   0

    7   00644   00000   00644   1   0   0
    8   00644   00644   00000   1   0   0
    9   00000   00644   00644   0   0   0
  } {
    faultsim_restore

  }
} {4 10}
do_test wal2-1.1 {
  execsql { SELECT count(a), sum(a) FROM t1 } db2
} {4 10}

set RECOVER [list                                      \
  {0 1 lock exclusive}   {1 2 lock exclusive} {4 4 lock exclusive} \
  {1 2 unlock exclusive} {4 4 unlock exclusive} {0 1 unlock exclusive}  \
]
set READ [list                                         \
  {4 1 lock shared}    {4 1 unlock shared}             \
]
set INITSLOT [list                                     \
  {4 1 lock exclusive} {4 1 unlock exclusive}          \
]
................................................................................
# UPDATE: This has now changed. When running a checkpoint, if recovery is
# required the client grabs all exclusive locks (just as it would for a
# recovery performed as a pre-cursor to a normal database transaction).
#
set expected_locks [list]
lappend expected_locks {1 1 lock exclusive}   ;# Lock checkpoint
lappend expected_locks {0 1 lock exclusive}   ;# Lock writer
lappend expected_locks {2 1 lock exclusive}   ;# Lock recovery
lappend expected_locks {4 4 lock exclusive}   ;# Lock all aReadMark[]
lappend expected_locks {2 1 unlock exclusive} ;# Unlock recovery 
lappend expected_locks {4 4 unlock exclusive} ;# Unlock all aReadMark[] 
lappend expected_locks {0 1 unlock exclusive} ;# Unlock writer
lappend expected_locks {3 1 lock exclusive}   ;# Lock aReadMark[0]
lappend expected_locks {3 1 unlock exclusive} ;# Unlock aReadMark[0]
lappend expected_locks {1 1 unlock exclusive} ;# Unlock checkpoint
do_test wal2-5.1 {
  proc tvfs_cb {method args} {
    set ::shm_file [lindex $args 0]
................................................................................
  testvfs tvfs
  tvfs script tvfs_cb
  sqlite3 db test.db -vfs tvfs
  set {} {}
} {}

set RECOVERY {
  {0 1 lock exclusive} {1 2 lock exclusive} {4 4 lock exclusive}
  {1 2 unlock exclusive} {4 4 unlock exclusive} {0 1 unlock exclusive}
}
set READMARK0_READ {
  {3 1 lock shared} {3 1 unlock shared}
}
set READMARK0_WRITE {
  {3 1 lock shared} 
  {0 1 lock exclusive} {3 1 unlock shared} 
................................................................................
    list [file exists test.db-shm] [file exists test.db-wal]
  } {1 1}
  faultsim_save_and_close

  foreach {tn db_perm wal_perm shm_perm can_open can_read can_write} {
    2   00644   00644   00644   1   1   1
    3   00644   00400   00644   1   1   0
    4   00644   00644   00400   1   1   0
    5   00400   00644   00644   1   1   0

    7   00644   00000   00644   1   0   0
    8   00644   00644   00000   1   0   0
    9   00000   00644   00644   0   0   0
  } {
    faultsim_restore

  do_test 1.1.13  { sql2 "INSERT INTO t1 VALUES('i', 'j')" } {}

  do_test 1.2.1 {
    code2 { db2 close }
    code1 { db close }
    list [file exists test.db-wal] [file exists test.db-shm]
  } {1 1}

  do_test 1.2.2 {
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    sql1 { SELECT * FROM t1 }
  } {a b c d e f g h i j}

  do_test 1.2.3 {
    code1 { db close }
    file attributes test.db-shm -permissions rw-r--r--
    hexio_write test.db-shm 0 01020304 
    file attributes test.db-shm -permissions r--r--r--
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM t1 }
  } {1 {attempt to write a readonly database}}
  do_test 1.2.4 {
    code1 { sqlite3_extended_errcode db } 
  } {SQLITE_READONLY_RECOVERY}

  do_test 1.2.5 {
    file attributes test.db-shm -permissions rw-r--r--
    code2 { sqlite3 db2 test.db }
    sql2 "SELECT * FROM t1" 
  } {a b c d e f g h i j}
  file attributes test.db-shm -permissions r--r--r--
................................................................................
    set {} {}
  } {}
  do_test 1.2.8 { sql1 "SELECT * FROM t1" } {a b c d e f g h i j k l}

  # Now check that if the readonly_shm option is not supplied, or if it
  # is set to zero, it is not possible to connect to the database without
  # read-write access to the shm.




  do_test 1.3.1 {
    code1 { db close }
    code1 { sqlite3 db test.db }
    csql1 { SELECT * FROM t1 }
  } {1 {unable to open database file}}

  # Also test that if the -shm file can be opened for read/write access,
  # it is not if readonly_shm=1 is present in the URI.
  do_test 1.3.2.1 {
    code1 { db close }
    code2 { db2 close }
    file exists test.db-shm
................................................................................
  } {1 {unable to open database file}}
  do_test 1.3.2.3 {
    code1 { db close }
    close [open test.db-shm w]
    file attributes test.db-shm -permissions r--r--r--
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM t1 }
  } {1 {attempt to write a readonly database}}
  do_test 1.3.2.4 {
    code1 { sqlite3_extended_errcode db } 
  } {SQLITE_READONLY_RECOVERY}

  #-----------------------------------------------------------------------
  # Test cases 1.4.* check that checkpoints and log wraps don't prevent
  # read-only connections from reading the database.
  do_test 1.4.1 {
    code1 { db close }
    forcedelete test.db-shm

  do_test 1.1.13  { sql2 "INSERT INTO t1 VALUES('i', 'j')" } {}

  do_test 1.2.1 {
    code2 { db2 close }
    code1 { db close }
    list [file exists test.db-wal] [file exists test.db-shm]
  } {1 1}

  do_test 1.2.2 {
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    list [catch { sql1 { SELECT * FROM t1 } } msg] $msg
  } {0 {a b c d e f g h i j}}

  do_test 1.2.3 {
    code1 { db close }
    file attributes test.db-shm -permissions rw-r--r--
    hexio_write test.db-shm 0 01020304 
    file attributes test.db-shm -permissions r--r--r--
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM t1 }
  } {0 {a b c d e f g h i j}}
  do_test 1.2.4 {
    code1 { sqlite3_extended_errcode db } 
  } {SQLITE_OK}

  do_test 1.2.5 {
    file attributes test.db-shm -permissions rw-r--r--
    code2 { sqlite3 db2 test.db }
    sql2 "SELECT * FROM t1" 
  } {a b c d e f g h i j}
  file attributes test.db-shm -permissions r--r--r--
................................................................................
    set {} {}
  } {}
  do_test 1.2.8 { sql1 "SELECT * FROM t1" } {a b c d e f g h i j k l}

  # Now check that if the readonly_shm option is not supplied, or if it
  # is set to zero, it is not possible to connect to the database without
  # read-write access to the shm.
  # 
  # UPDATE: os_unix.c now opens the *-shm file in readonly mode 
  # automatically.
  #
  do_test 1.3.1 {
    code1 { db close }
    code1 { sqlite3 db test.db }
    csql1 { SELECT * FROM t1 }
  } {0 {a b c d e f g h i j k l}}

  # Also test that if the -shm file can be opened for read/write access,
  # it is not if readonly_shm=1 is present in the URI.
  do_test 1.3.2.1 {
    code1 { db close }
    code2 { db2 close }
    file exists test.db-shm
................................................................................
  } {1 {unable to open database file}}
  do_test 1.3.2.3 {
    code1 { db close }
    close [open test.db-shm w]
    file attributes test.db-shm -permissions r--r--r--
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    csql1 { SELECT * FROM t1 }
  } {0 {a b c d e f g h i j k l}}
  do_test 1.3.2.4 {
    code1 { sqlite3_extended_errcode db } 
  } {SQLITE_OK}

  #-----------------------------------------------------------------------
  # Test cases 1.4.* check that checkpoints and log wraps don't prevent
  # read-only connections from reading the database.
  do_test 1.4.1 {
    code1 { db close }
    forcedelete test.db-shm

# 2011 May 09
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains tests for using WAL databases in read-only mode.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
set ::testprefix walro2

# And only if the build is WAL-capable.
#
ifcapable !wal {
  finish_test
  return
}

proc copy_to_test2 {bZeroShm} {
  forcecopy test.db test.db2
  forcecopy test.db-wal test.db2-wal
  if {$bZeroShm} {
    forcedelete test.db2-shm
    set fd [open test.db2-shm w]
    seek $fd [expr [file size test.db-shm]-1]
    puts -nonewline $fd "\0"
    close $fd
  } else {
    forcecopy test.db-shm test.db2-shm
  }
}

foreach bZeroShm {0 1} {
set TN [expr $bZeroShm+1]
do_multiclient_test tn {
  
  # Close all connections and delete the database.
  #
  code1 { db close  }
  code2 { db2 close }
  code3 { db3 close }
  forcedelete test.db
  
  # Do not run tests with the connections in the same process.
  #
  if {$tn==2} continue

  foreach c {code1 code2 code3} {
    $c {
      sqlite3_shutdown
      sqlite3_config_uri 1
    }
  }

  do_test $TN.1.1 {
    code2 { sqlite3 db2 test.db }
    sql2 { 
      CREATE TABLE t1(x, y);
      PRAGMA journal_mode = WAL;
      INSERT INTO t1 VALUES('a', 'b');
      INSERT INTO t1 VALUES('c', 'd');
    }
    file exists test.db-shm
  } {1}

  do_test $TN.1.2.1 {
    copy_to_test2 $bZeroShm
    code1 {
      sqlite3 db file:test.db2?readonly_shm=1
    }

    sql1 { SELECT * FROM t1 }
  } {a b c d}
  do_test $TN.1.2.2 {
    sql1 { SELECT * FROM t1 }
  } {a b c d}

  do_test $TN.1.3.1 {
    code3 { sqlite3 db3 test.db2 }
    sql3 { SELECT * FROM t1 }
  } {a b c d}

  do_test $TN.1.3.2 {
    sql1 { SELECT * FROM t1 }
  } {a b c d}

  code1 { db close  }
  code2 { db2 close }
  code3 { db3 close }

  do_test $TN.2.1 {
    code2 { sqlite3 db2 test.db }
    sql2 { 
      INSERT INTO t1 VALUES('e', 'f');
      INSERT INTO t1 VALUES('g', 'h');
    }
    file exists test.db-shm
  } {1}

  do_test $TN.2.2 {
    copy_to_test2 $bZeroShm
    code1 {
      sqlite3 db file:test.db2?readonly_shm=1
    }
    sql1 { 
      BEGIN;
      SELECT * FROM t1;
    }
  } {a b c d e f g h}

  do_test $TN.2.3.1 {
    code3 { sqlite3 db3 test.db2 }
    sql3 { SELECT * FROM t1 }
  } {a b c d e f g h}
  do_test $TN.2.3.2 {
    sql3 { INSERT INTO t1 VALUES('i', 'j') }
    code3 { db3 close }
    sql1 { COMMIT } 
  } {}
  do_test $TN.2.3.3 {
    sql1 { SELECT * FROM t1 }
  } {a b c d e f g h i j}


  #-----------------------------------------------------------------------
  # 3.1.*: That a readonly_shm connection can read a database file if both
  #        the *-wal and *-shm files are zero bytes in size.
  #
  # 3.2.*: That it flushes the cache if, between transactions on a db with a
  #        zero byte *-wal file, some other connection modifies the db, then
  #        does "PRAGMA wal_checkpoint=truncate" to truncate the wal file
  #        back to zero bytes in size.
  #
  # 3.3.*: That, if between transactions some other process wraps the wal
  #        file, the readonly_shm client reruns recovery.
  #
  catch { code1 { db close } }
  catch { code2 { db2 close } }
  catch { code3 { db3 close } }
  do_test $TN.3.1.0 {
    list [file exists test.db-wal] [file exists test.db-shm]
  } {0 0}
  do_test $TN.3.1.1 {
    close [open test.db-wal w]
    close [open test.db-shm w]
    code1 {
      sqlite3 db file:test.db?readonly_shm=1
    }
    sql1 { SELECT * FROM t1 }
  } {a b c d e f g h}

  do_test $TN.3.2.0 {
    list [file size test.db-wal] [file size test.db-shm]
  } {0 0}
  do_test $TN.3.2.1 {
    code2 { sqlite3 db2 test.db }
    sql2 { INSERT INTO t1 VALUES(1, 2) ; PRAGMA wal_checkpoint=truncate }
    code2 { db2 close }
    sql1 { SELECT * FROM t1 }
  } {a b c d e f g h 1 2}
  do_test $TN.3.2.2 {
    list [file size test.db-wal] [file size test.db-shm]
  } {0 32768}

  do_test $TN.3.3.0 {
    code2 { sqlite3 db2 test.db }
    sql2 { 
      INSERT INTO t1 VALUES(3, 4);
      INSERT INTO t1 VALUES(5, 6);
      INSERT INTO t1 VALUES(7, 8);
      INSERT INTO t1 VALUES(9, 10);
    }
    code2 { db2 close }
    code1 { db close }
    list [file size test.db-wal] [file size test.db-shm]
  } [list [wal_file_size 4 1024] 32768]
  do_test $TN.3.3.1 {
    code1 { sqlite3 db file:test.db?readonly_shm=1 }
    sql1 { SELECT * FROM t1 }
  } {a b c d e f g h 1 2 3 4 5 6 7 8 9 10}
  do_test $TN.3.3.2 {
    code2 { sqlite3 db2 test.db }
    sql2 { 
      PRAGMA wal_checkpoint; 
      DELETE FROM t1;
      INSERT INTO t1 VALUES('i', 'ii');
    }
    code2 { db2 close }
    list [file size test.db-wal] [file size test.db-shm]
  } [list [wal_file_size 4 1024] 32768]
  do_test $TN.3.3.3 {
    sql1 { SELECT * FROM t1 }
  } {i ii}

  #-----------------------------------------------------------------------
  #
  #
  catch { code1 { db close } }
  catch { code2 { db2 close } }
  catch { code3 { db3 close } }

  do_test $TN.4.0 {
    code1 { forcedelete test.db }
    code1 { sqlite3 db test.db }
    sql1 {
      PRAGMA journal_mode = wal;
      CREATE TABLE t1(x);
      INSERT INTO t1 VALUES('hello');
      INSERT INTO t1 VALUES('world');
    }

    copy_to_test2 $bZeroShm

    code1 { db close }
  } {}

  do_test $TN.4.1.1 {
    code2 { sqlite3 db2 file:test.db2?readonly_shm=1 }
    sql2 { SELECT * FROM t1 }
  } {hello world}

  do_test $TN.4.1.2 {
    code3 { sqlite3 db3 test.db2 }
    sql3 {
      INSERT INTO t1 VALUES('!');
      PRAGMA wal_checkpoint = truncate;
    }
    code3 { db3 close }
  } {}
  do_test $TN.4.1.3 {
    sql2 { SELECT * FROM t1 }
  } {hello world !}

  catch { code1 { db close } }
  catch { code2 { db2 close } }
  catch { code3 { db3 close } }

  do_test $TN.4.2.1 {
    code1 { sqlite3 db test.db }
    sql1 {
      INSERT INTO t1 VALUES('!');
      INSERT INTO t1 VALUES('!');

      PRAGMA cache_size = 10;
      CREATE TABLE t2(x);

      BEGIN;
        WITH s(i) AS (
          SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<500
          )
        INSERT INTO t2 SELECT randomblob(500) FROM s;
        SELECT count(*) FROM t2;
    } 
  } {500}
  do_test $TN.4.2.2 {
    file size test.db-wal
  } {461152}
  do_test $TN.4.2.4 {
    file_control_persist_wal db 1; db close

    copy_to_test2 $bZeroShm
    code2 { sqlite3 db2 file:test.db2?readonly_shm=1 }
    sql2 {
      SELECT * FROM t1;
      SELECT count(*) FROM t2;
    }
  } {hello world ! ! 0}

  #-----------------------------------------------------------------------
  #
  #
  catch { code1 { db close } }
  catch { code2 { db2 close } }
  catch { code3 { db3 close } }

  do_test $TN.5.0 {
    code1 { forcedelete test.db }
    code1 { sqlite3 db test.db }
    sql1 {
      PRAGMA journal_mode = wal;
      CREATE TABLE t1(x);
      INSERT INTO t1 VALUES('hello');
      INSERT INTO t1 VALUES('world');
      INSERT INTO t1 VALUES('!');
      INSERT INTO t1 VALUES('world');
      INSERT INTO t1 VALUES('hello');
    }

    copy_to_test2 $bZeroShm
    
    code1 { db close }
  } {}

  do_test $TN.5.1 {
    code2 { sqlite3 db2 file:test.db2?readonly_shm=1 }
    sql2 {
      SELECT * FROM t1;
    }
  } {hello world ! world hello}

  do_test $TN.5.2 {
    code1 {
      proc handle_read {op args} {
        if {$op=="xRead" && [file tail [lindex $args 0]]=="test.db2-wal"} {
          set ::res2 [sql2 { SELECT * FROM t1 }]
        }
        puts "$msg xRead $args"
        return "SQLITE_OK"
      }
      testvfs tvfs -fullshm 1

      sqlite3 db file:test.db2?vfs=tvfs
      db eval { SELECT * FROM sqlite_master }

      tvfs filter xRead
      tvfs script handle_read
    }
    sql1 {
      PRAGMA wal_checkpoint = truncate;
    }
    code1 { set ::res2 }
  } {hello world ! world hello}

  do_test $TN.5.3 {
    code1 { db close }
    code1 { tvfs delete }
  } {}

  #-----------------------------------------------------------------------
  #
  #
  catch { code1 { db close } }
  catch { code2 { db2 close } }
  catch { code3 { db3 close } }

  do_test $TN.6.1 {
    code1 { forcedelete test.db }
    code1 { sqlite3 db test.db }
    sql1 {
      PRAGMA journal_mode = wal;
      CREATE TABLE t1(x);
      INSERT INTO t1 VALUES('hello');
      INSERT INTO t1 VALUES('world');
      INSERT INTO t1 VALUES('!');
      INSERT INTO t1 VALUES('world');
      INSERT INTO t1 VALUES('hello');
    }

    copy_to_test2 $bZeroShm
    
    code1 { db close }
  } {}

  do_test $TN.6.2 {
    code1 {
      set ::nRem 5
      proc handle_read {op args} {
        if {$op=="xRead" && [file tail [lindex $args 0]]=="test.db2-wal"} {
          incr ::nRem -1
          if {$::nRem==0} {
            code2 { sqlite3 db2 test.db2 }
            sql2  { PRAGMA wal_checkpoint = truncate }
          }
        }
        return "SQLITE_OK"
      }
      testvfs tvfs -fullshm 1

      tvfs filter xRead
      tvfs script handle_read

      sqlite3 db file:test.db2?readonly_shm=1&vfs=tvfs
      db eval { SELECT * FROM t1 }
    }
  } {hello world ! world hello}

  do_test $TN.6.3 {
    code1 { db close }
    code1 { tvfs delete }
  } {}
}
} ;# foreach bZeroShm

finish_test

# 2011 May 09
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains tests for using WAL databases in read-only mode.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl
set ::testprefix walro2

# And only if the build is WAL-capable.
#
ifcapable !wal {
  finish_test
  return
}

db close
sqlite3_shutdown
sqlite3_config_uri 1
sqlite3 db test.db

do_execsql_test 1.0 {
  CREATE TABLE t1(b);
  PRAGMA journal_mode = wal;
  INSERT INTO t1 VALUES('hello');
  INSERT INTO t1 VALUES('world');
  INSERT INTO t1 VALUES('!');
  INSERT INTO t1 VALUES('world');
  INSERT INTO t1 VALUES('hello');
  PRAGMA cache_size = 10;
  BEGIN;
    WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<30 ) 
    INSERT INTO t1(b) SELECT randomblob(800) FROM s;
} {wal}
file_control_persist_wal db 1; db close
faultsim_save_and_close

do_faultsim_test 1 -faults oom* -prep {
  catch { db close }
  faultsim_restore
  sqlite3 db file:test.db?readonly_shm=1
} -body {
  execsql { SELECT * FROM t1 }
} -test {
  faultsim_test_result {0 {hello world ! world hello}}
}



finish_test

# 2008 October 6
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing fault-injection with the 
# LIMIT ... OFFSET ... clause of UPDATE and DELETE statements.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/malloc_common.tcl
set testprefix wherelfault

ifcapable !update_delete_limit {
  finish_test
  return
}

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(1, 'f');
  INSERT INTO t1 VALUES(2, 'e');
  INSERT INTO t1 VALUES(3, 'd');
  INSERT INTO t1 VALUES(4, 'c');
  INSERT INTO t1 VALUES(5, 'b');
  INSERT INTO t1 VALUES(6, 'a');

  CREATE VIEW v1 AS SELECT a,b FROM t1;
  CREATE TABLE log(op, a);

  CREATE TRIGGER v1del INSTEAD OF DELETE ON v1 BEGIN
    INSERT INTO log VALUES('delete', old.a);
  END;

  CREATE TRIGGER v1upd INSTEAD OF UPDATE ON v1 BEGIN
    INSERT INTO log VALUES('update', old.a);
  END;
}

faultsim_save_and_close
do_faultsim_test 1.1 -prep {
  faultsim_restore_and_reopen
  db eval {SELECT * FROM sqlite_master}
} -body {
  execsql { DELETE FROM v1 ORDER BY a LIMIT 3; }
} -test {
  faultsim_test_result {0 {}} 
}

do_faultsim_test 1.2 -prep {
  faultsim_restore_and_reopen
  db eval {SELECT * FROM sqlite_master}
} -body {
  execsql { UPDATE v1 SET b = 555 ORDER BY a LIMIT 3 }
} -test {
  faultsim_test_result {0 {}} 
}

#-------------------------------------------------------------------------
sqlite3 db test.db
do_execsql_test 2.1.0 {
  CREATE TABLE t2(a, b, c, PRIMARY KEY(a, b)) WITHOUT ROWID;
}
faultsim_save_and_close

do_faultsim_test 2.1 -prep {
  faultsim_restore_and_reopen
  db eval {SELECT * FROM sqlite_master}
} -body {
  execsql { DELETE FROM t2 WHERE c=? ORDER BY a DESC LIMIT 10 }
} -test {
  faultsim_test_result {0 {}} 
}

finish_test

    COMMIT;
  }
  return {}
}

ifcapable {update_delete_limit} {



  # check syntax error support
  do_test wherelimit-0.1 {
    catchsql {DELETE FROM t1 ORDER BY x}
  } {1 {ORDER BY without LIMIT on DELETE}}
  do_test wherelimit-0.2 {
    catchsql {DELETE FROM t1 WHERE x=1 ORDER BY x}
  } {1 {ORDER BY without LIMIT on DELETE}}
  do_test wherelimit-0.3 {
    catchsql {UPDATE t1 SET y=1 WHERE x=1 ORDER BY x}
  } {1 {ORDER BY without LIMIT on UPDATE}}



  # no AS on table sources
  do_test wherelimit-0.4 {
    catchsql {DELETE FROM t1 AS a WHERE x=1}
  } {1 {near "AS": syntax error}}
  do_test wherelimit-0.5 {
    catchsql {UPDATE t1 AS a SET y=1 WHERE x=1}
................................................................................
    execsql {UPDATE t1 SET y=1 WHERE x=2 ORDER BY x LIMIT 30, 50}
    execsql {SELECT count(*) FROM t1 WHERE y=1}
  } {6}
  do_test wherelimit-3.13 {
    execsql {UPDATE t1 SET y=1 WHERE x=3 ORDER BY x LIMIT 50 OFFSET 50}
    execsql {SELECT count(*) FROM t1 WHERE y=1}
  } {6}





































}


finish_test

    COMMIT;
  }
  return {}
}

ifcapable {update_delete_limit} {

  execsql { CREATE TABLE t1(x, y) }

  # check syntax error support
  do_test wherelimit-0.1 {
    catchsql {DELETE FROM t1 ORDER BY x}
  } {1 {ORDER BY without LIMIT on DELETE}}
  do_test wherelimit-0.2 {
    catchsql {DELETE FROM t1 WHERE x=1 ORDER BY x}
  } {1 {ORDER BY without LIMIT on DELETE}}
  do_test wherelimit-0.3 {
    catchsql {UPDATE t1 SET y=1 WHERE x=1 ORDER BY x}
  } {1 {ORDER BY without LIMIT on UPDATE}}

  execsql { DROP TABLE t1 }

  # no AS on table sources
  do_test wherelimit-0.4 {
    catchsql {DELETE FROM t1 AS a WHERE x=1}
  } {1 {near "AS": syntax error}}
  do_test wherelimit-0.5 {
    catchsql {UPDATE t1 AS a SET y=1 WHERE x=1}
................................................................................
    execsql {UPDATE t1 SET y=1 WHERE x=2 ORDER BY x LIMIT 30, 50}
    execsql {SELECT count(*) FROM t1 WHERE y=1}
  } {6}
  do_test wherelimit-3.13 {
    execsql {UPDATE t1 SET y=1 WHERE x=3 ORDER BY x LIMIT 50 OFFSET 50}
    execsql {SELECT count(*) FROM t1 WHERE y=1}
  } {6}

  # Cannot use a LIMIT for UPDATE or DELETE against a WITHOUT ROWID table
  # or a VIEW.  (We should fix this someday).
  #
  db close
  sqlite3 db :memory:
  do_execsql_test wherelimit-4.1 {
    CREATE TABLE t1(a int);
    INSERT INTO t1 VALUES(1);
    INSERT INTO t1 VALUES(2);
    INSERT INTO t1 VALUES(3);
    CREATE TABLE t2(a int);
    INSERT INTO t2 SELECT a+100 FROM t1;
    CREATE VIEW tv(r,a) AS
       SELECT rowid, a FROM t2 UNION ALL SELECT rowid, a FROM t1;
    CREATE TRIGGER tv_del INSTEAD OF DELETE ON tv
    BEGIN
      DELETE FROM t1 WHERE rowid=old.r;
      DELETE FROM t2 WHERE rowid=old.r;
    END;
  } {}
  do_catchsql_test wherelimit-4.2 {
    DELETE FROM tv WHERE 1 LIMIT 2;
  } {0 {}}
  do_catchsql_test wherelimit-4.3 {
    DELETE FROM tv WHERE 1 ORDER BY a LIMIT 2;
  } {0 {}}
  do_execsql_test wherelimit-4.10 {
    CREATE TABLE t3(a,b,c,d TEXT, PRIMARY KEY(a,b)) WITHOUT ROWID;
    INSERT INTO t3(a,b,c,d) VALUES(1,2,3,4),(5,6,7,8),(9,10,11,12);
  } {}
  do_catchsql_test wherelimit-4.11 {
    DELETE FROM t3 WHERE a=5 LIMIT 2;
  } {0 {}}
  do_execsql_test wherelimit-4.12 {
    SELECT a,b,c,d FROM t3 ORDER BY 1;
  } {1 2 3 4 9 10 11 12}

}

finish_test

# 2008 October 6
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the LIMIT ... OFFSET ... clause
#  of UPDATE and DELETE statements.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix wherelimit2

ifcapable !update_delete_limit {
  finish_test
  return
}

#-------------------------------------------------------------------------
# Test with views and INSTEAD OF triggers.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(1, 'f');
  INSERT INTO t1 VALUES(2, 'e');
  INSERT INTO t1 VALUES(3, 'd');
  INSERT INTO t1 VALUES(4, 'c');
  INSERT INTO t1 VALUES(5, 'b');
  INSERT INTO t1 VALUES(6, 'a');

  CREATE VIEW v1 AS SELECT a,b FROM t1;
  CREATE TABLE log(op, a);

  CREATE TRIGGER v1del INSTEAD OF DELETE ON v1 BEGIN
    INSERT INTO log VALUES('delete', old.a);
  END;

  CREATE TRIGGER v1upd INSTEAD OF UPDATE ON v1 BEGIN
    INSERT INTO log VALUES('update', old.a);
  END;
}

do_execsql_test 1.1 {
  DELETE FROM v1 ORDER BY a LIMIT 3;
  SELECT * FROM log; DELETE FROM log;
} {
  delete 1 delete 2 delete 3
}
do_execsql_test 1.2 {
  DELETE FROM v1 ORDER BY b LIMIT 3;
  SELECT * FROM log; DELETE FROM log;
} {
  delete 6 delete 5 delete 4
}
do_execsql_test 1.3 {
  UPDATE v1 SET b = 555 ORDER BY a LIMIT 3;
  SELECT * FROM log; DELETE FROM log;
} {
  update 1 update 2 update 3
}
do_execsql_test 1.4 {
  UPDATE v1 SET b = 555 ORDER BY b LIMIT 3;
  SELECT * FROM log; DELETE FROM log;
} {
  update 6 update 5 update 4
}

#-------------------------------------------------------------------------
# Simple test using WITHOUT ROWID table.
#
do_execsql_test 2.1.0 {
  CREATE TABLE t2(a, b, c, PRIMARY KEY(a, b)) WITHOUT ROWID;
  INSERT INTO t2 VALUES(1, 1, 'h');
  INSERT INTO t2 VALUES(1, 2, 'g');
  INSERT INTO t2 VALUES(2, 1, 'f');
  INSERT INTO t2 VALUES(2, 2, 'e');
  INSERT INTO t2 VALUES(3, 1, 'd');
  INSERT INTO t2 VALUES(3, 2, 'c');
  INSERT INTO t2 VALUES(4, 1, 'b');
  INSERT INTO t2 VALUES(4, 2, 'a');
}

do_execsql_test 2.1.1 {
  BEGIN;
    DELETE FROM t2 WHERE b=1 ORDER BY c LIMIT 2;
    SELECT c FROM t2 ORDER BY 1;
  ROLLBACK;
} {a c e f g h}

do_execsql_test 2.1.2 {
  BEGIN;
    UPDATE t2 SET c=NULL ORDER BY a, b DESC LIMIT 3 OFFSET 1;
    SELECT a, b, c FROM t2;
  ROLLBACK;
} {
  1 1 {} 
  1 2 g 
  2 1 {} 
  2 2 {} 
  3 1 d 
  3 2 c 
  4 1 b 
  4 2 a
}

do_execsql_test 2.2.0 {
  DROP TABLE t2;
  CREATE TABLE t2(a INTEGER PRIMARY KEY, b, c) WITHOUT ROWID;
  INSERT INTO t2 VALUES(1, 1, 'h');
  INSERT INTO t2 VALUES(2, 2, 'g');
  INSERT INTO t2 VALUES(3, 1, 'f');
  INSERT INTO t2 VALUES(4, 2, 'e');
  INSERT INTO t2 VALUES(5, 1, 'd');
  INSERT INTO t2 VALUES(6, 2, 'c');
  INSERT INTO t2 VALUES(7, 1, 'b');
  INSERT INTO t2 VALUES(8, 2, 'a');
}

do_execsql_test 2.2.1 {
  BEGIN;
    DELETE FROM t2 WHERE b=1 ORDER BY c LIMIT 2;
    SELECT c FROM t2 ORDER BY 1;
  ROLLBACK;
} {a c e f g h}

do_execsql_test 2.2.2 {
  BEGIN;
    UPDATE t2 SET c=NULL ORDER BY a DESC LIMIT 3 OFFSET 1;
    SELECT a, b, c FROM t2;
  ROLLBACK;
} {
  1 1 h
  2 2 g 
  3 1 f
  4 2 e
  5 1 {}
  6 2 {} 
  7 1 {} 
  8 2 a
}

#-------------------------------------------------------------------------
# Test using a virtual table
#
ifcapable fts5 {
  do_execsql_test 3.0 {
    CREATE VIRTUAL TABLE ft USING fts5(x);
    INSERT INTO ft(rowid, x) VALUES(-45,   'a a');
    INSERT INTO ft(rowid, x) VALUES(12,    'a b');
    INSERT INTO ft(rowid, x) VALUES(444,   'a c');
    INSERT INTO ft(rowid, x) VALUES(12300, 'a d');
    INSERT INTO ft(rowid, x) VALUES(25400, 'a c');
    INSERT INTO ft(rowid, x) VALUES(25401, 'a b');
    INSERT INTO ft(rowid, x) VALUES(50000, 'a a');
  }

  do_execsql_test 3.1.1 {
    BEGIN;
      DELETE FROM ft ORDER BY rowid LIMIT 3;
      SELECT x FROM ft;
    ROLLBACK;
  } {{a d} {a c} {a b} {a a}}

  do_execsql_test 3.1.2 {
    BEGIN;
      DELETE FROM ft WHERE ft MATCH 'a' ORDER BY rowid LIMIT 3;
      SELECT x FROM ft;
    ROLLBACK;
  } {{a d} {a c} {a b} {a a}}
  
  do_execsql_test 3.1.3 {
    BEGIN;
      DELETE FROM ft WHERE ft MATCH 'b' ORDER BY rowid ASC LIMIT 1 OFFSET 1;
      SELECT rowid FROM ft;
    ROLLBACK;
  } {-45 12 444 12300 25400 50000}

  do_execsql_test 3.2.1 {
    BEGIN;
      UPDATE ft SET x='hello' ORDER BY rowid LIMIT 2 OFFSET 2;
      SELECT x FROM ft;
    ROLLBACK;
  } {{a a} {a b} hello hello {a c} {a b} {a a}}

  do_execsql_test 3.2.2 {
    BEGIN;
      UPDATE ft SET x='hello' WHERE ft MATCH 'a' 
          ORDER BY rowid DESC LIMIT 2 OFFSET 2;
      SELECT x FROM ft;
    ROLLBACK;
  } {{a a} {a b} {a c} hello hello {a b} {a a}}
} ;# fts5

#-------------------------------------------------------------------------
# Test using INDEXED BY clauses.
#
do_execsql_test 4.0 {
  CREATE TABLE x1(a INTEGER PRIMARY KEY, b, c, d);
  CREATE INDEX x1bc ON x1(b, c);
  INSERT INTO x1 VALUES(1,1,1,1);
  INSERT INTO x1 VALUES(2,1,2,2);
  INSERT INTO x1 VALUES(3,2,1,3);
  INSERT INTO x1 VALUES(4,2,2,3);
  INSERT INTO x1 VALUES(5,3,1,2);
  INSERT INTO x1 VALUES(6,3,2,1);
}

do_execsql_test 4.1 {
  BEGIN;
    DELETE FROM x1 ORDER BY a LIMIT 2;
    SELECT a FROM x1;
  ROLLBACK;
} {3 4 5 6}

do_catchsql_test 4.2 {
  DELETE FROM x1 INDEXED BY x1bc WHERE d=3 LIMIT 1;
} {1 {no query solution}}

do_execsql_test 4.3 {
  DELETE FROM x1 INDEXED BY x1bc WHERE b=3 LIMIT 1;
  SELECT a FROM x1;
} {1 2 3 4 6}

do_catchsql_test 4.4 {
  UPDATE x1 INDEXED BY x1bc SET d=5 WHERE d=3 LIMIT 1;
} {1 {no query solution}}

do_execsql_test 4.5 {
  UPDATE x1 INDEXED BY x1bc SET d=5 WHERE b=2 LIMIT 1;
  SELECT a, d FROM x1;
} {1 1 2 2 3 5 4 3 6 1}

#-------------------------------------------------------------------------
# Test using object names that require quoting.
#
do_execsql_test 5.0 {
  CREATE TABLE "x y"("a b" PRIMARY KEY, "c d") WITHOUT ROWID;
  CREATE INDEX xycd ON "x y"("c d");

  INSERT INTO "x y" VALUES('a', 'a');
  INSERT INTO "x y" VALUES('b', 'b');
  INSERT INTO "x y" VALUES('c', 'c');
  INSERT INTO "x y" VALUES('d', 'd');
  INSERT INTO "x y" VALUES('e', 'a');
  INSERT INTO "x y" VALUES('f', 'b');
  INSERT INTO "x y" VALUES('g', 'c');
  INSERT INTO "x y" VALUES('h', 'd');
}

do_execsql_test 5.1 {
  BEGIN;
    DELETE FROM "x y" WHERE "c d"!='e' ORDER BY "c d" LIMIT 2 OFFSET 2;
    SELECT * FROM "x y" ORDER BY 1;
  ROLLBACK;
} {
  a a c c d d e a g c h d
}

do_execsql_test 5.2 {
  BEGIN;
    UPDATE "x y" SET "c d"='e' WHERE "c d"!='e' ORDER BY "c d" LIMIT 2 OFFSET 2;
    SELECT * FROM "x y" ORDER BY 1;
  ROLLBACK;
} {
  a a b e c c d d e a f e g c h d
}

proc log {args} { lappend ::log {*}$args }
db func log log
do_execsql_test 5.3 {
  CREATE VIEW "v w" AS SELECT * FROM "x y";
  CREATE TRIGGER tr1 INSTEAD OF DELETE ON "v w" BEGIN
    SELECT log(old."a b", old."c d");
  END;
  CREATE TRIGGER tr2 INSTEAD OF UPDATE ON "v w" BEGIN
    SELECT log(new."a b", new."c d");
  END;
}

do_test 5.4 {
  set ::log {}
  execsql { DELETE FROM "v w" ORDER BY "a b" LIMIT 3 }
  set ::log
} {a a b b c c}

do_test 5.5 {
  set ::log {}
  execsql { UPDATE "v w" SET "a b" = "a b" || 'x' ORDER BY "a b" LIMIT 5; }
  set ::log
} {ax a bx b cx c dx d ex a}


finish_test