SQLite

	$(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)

showstat4$(TEXE):	$(TOP)/tool/showstat4.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/tool/showstat4.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 \
  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 \

3.22.0

AM_CFLAGS = @THREADSAFE_FLAGS@ @DYNAMIC_EXTENSION_FLAGS@ @FTS5_FLAGS@ @JSON1_FLAGS@ @SESSION_FLAGS@ -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE

lib_LTLIBRARIES = libsqlite3.la
libsqlite3_la_SOURCES = sqlite3.c
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

# 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])
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 3.22.0.
#
#
# 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) -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 && 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 );




  /* 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|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);
    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 
** 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_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_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 [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 [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 [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 [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 [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-1.1.1 {
  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)"
}

create_t1
populate_t1
do_test rtreeA-3.3.0 { 
  execsql { DELETE FROM t1 WHERE rowid = 0 }
  set_tree_depth t1 65535
} {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
do_execsql_test rtreeA-7.100 { 
  UPDATE t1_node SET data=x'' WHERE rowid=1;
} {}
do_catchsql_test rtreeA-7.110 {
  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 [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 [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 [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 [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 [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
}

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$(EXE) \
  sqlite3_checker$(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;
    }



    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( 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 */
  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;
}

/*
** Disconnect from or destroy a dbpagevfs virtual table.
*/
static int dbpageDisconnect(sqlite3_vtab *pVtab){
  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 dbpageNext(sqlite3_vtab_cursor *pCursor){
  int rc = SQLITE_OK;
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  pCsr->pgno++;
  return rc;
}

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){
  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
  *pRowid = pCsr->pgno;
  return SQLITE_OK;
}

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 */
    dbpageConnect,                /* xCreate */
    dbpageConnect,                /* xConnect */
    dbpageBestIndex,              /* xBestIndex */
    dbpageDisconnect,             /* xDisconnect */
    dbpageDisconnect,             /* xDestroy */
    dbpageOpen,                   /* xOpen - open a cursor */
    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 */
  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);
  pWhere = sqlite3ExprDup(db, pWhere, 0);
  pFrom = sqlite3SrcListAppend(db, 0, 0, 0);
  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);

    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, 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 ){
        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);
        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_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)

#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 */
  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);
#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 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;}
where_opt(A) ::= WHERE expr(X).       {A = X.pExpr;}

////////////////////////// The UPDATE command ////////////////////////////////
//
%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) );
  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; 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);
#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;
      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);

    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);
      pDelete = p->pPrior;
      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.
    */
    struct ExprList_item *a = pEList->a;
    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>