SQLite

/*
** 2014-09-08
**
** 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 the application interface definitions for the
** user-authentication extension feature.
**
** To compile with the user-authentication feature, append this file to
** end of an SQLite amalgamation header file ("sqlite3.h"), then add
** the SQLITE_USER_AUTHENTICATION compile-time option.  See the
** user-auth.txt file in the same source directory as this file for
** additional information.
*/
#ifdef SQLITE_USER_AUTHENTICATION

/*
** If a database contains the SQLITE_USER table, then the
** sqlite3_user_authenticate() interface must be invoked with an
** appropriate username and password prior to enable read and write
** access to the database.
**
** Return SQLITE_OK on success or SQLITE_ERROR if the username/password
** combination is incorrect or unknown.
**
** If the SQLITE_USER table is not present in the database file, then
** this interface is a harmless no-op returnning SQLITE_OK.
*/
int sqlite3_user_authenticate(
  sqlite3 *db,           /* The database connection */
  const char *zUsername, /* Username */
  const char *aPW,       /* Password or credentials */
  int nPW                /* Number of bytes in aPW[] */
);

/*
** The sqlite3_user_add() interface can be used (by an admin user only)
** to create a new user.  When called on a no-authentication-required
** database, this routine converts the database into an authentication-
** required database, automatically makes the added user an
** administrator, and logs in the current connection as that user.
** The sqlite3_user_add() interface only works for the "main" database, not
** for any ATTACH-ed databases.  Any call to sqlite3_user_add() by a
** non-admin user results in an error.
*/
int sqlite3_user_add(
  sqlite3 *db,           /* Database connection */
  const char *zUsername, /* Username to be added */
  const char *aPW,       /* Password or credentials */
  int nPW,               /* Number of bytes in aPW[] */
  int isAdmin            /* True to give new user admin privilege */
);

/*
** The sqlite3_user_change() interface can be used to change a users
** login credentials or admin privilege.  Any user can change their own
** login credentials.  Only an admin user can change another users login
** credentials or admin privilege setting.  No user may change their own 
** admin privilege setting.
*/
int sqlite3_user_change(
  sqlite3 *db,           /* Database connection */
  const char *zUsername, /* Username to change */
  const char *aPW,       /* New password or credentials */
  int nPW,               /* Number of bytes in aPW[] */
  int isAdmin            /* Modified admin privilege for the user */
);

/*
** The sqlite3_user_delete() interface can be used (by an admin user only)
** to delete a user.  The currently logged-in user cannot be deleted,
** which guarantees that there is always an admin user and hence that
** the database cannot be converted into a no-authentication-required
** database.
*/
int sqlite3_user_delete(
  sqlite3 *db,           /* Database connection */
  const char *zUsername  /* Username to remove */
);

#endif /* SQLITE_USER_AUTHENTICATION */

Activate the user authentication logic by including the
ext/userauth/userauth.c source code file in the build and
adding the -DSQLITE_USER_AUTHENTICATION compile-time option.
The ext/userauth/sqlite3userauth.h header file is available to
applications to define the interface.

When using the SQLite amalgamation, it is sufficient to append
the ext/userauth/userauth.c source file onto the end of the
amalgamation.

The following new APIs are available when user authentication is
activated:

   int sqlite3_user_authenticate(
     sqlite3 *db,           /* The database connection */
     const char *zUsername, /* Username */
     const char *aPW,       /* Password or credentials */
     int nPW                /* Number of bytes in aPW[] */
   );
   
   int sqlite3_user_add(
     sqlite3 *db,           /* Database connection */
     const char *zUsername, /* Username to be added */
     const char *aPW,       /* Password or credentials */
     int nPW,               /* Number of bytes in aPW[] */
     int isAdmin            /* True to give new user admin privilege */
   );
   
   int sqlite3_user_change(
     sqlite3 *db,           /* Database connection */
     const char *zUsername, /* Username to change */
     const void *aPW,       /* Modified password or credentials */
     int nPW,               /* Number of bytes in aPW[] */
     int isAdmin            /* Modified admin privilege for the user */
   );
   
   int sqlite3_user_delete(
     sqlite3 *db,           /* Database connection */
     const char *zUsername  /* Username to remove */
   );

With this extension, a database can be marked as requiring authentication.
By default a database does not require authentication.

The sqlite3_open(), sqlite3_open16(), and sqlite3_open_v2() interfaces
work as before: they open a new database connection.  However, if the
database being opened requires authentication, then attempts to read
or write from the database will fail with an SQLITE_AUTH error until 
after sqlite3_user_authenticate() has been called successfully.  The 
sqlite3_user_authenticate() call will return SQLITE_OK if the 
authentication credentials are accepted and SQLITE_ERROR if not.

Calling sqlite3_user_authenticate() on a no-authentication-required
database connection is a harmless no-op.  

If the database is encrypted, then sqlite3_key_v2() must be called first,
with the correct decryption key, prior to invoking sqlite3_user_authenticate().

To recapitulate: When opening an existing unencrypted authentication-
required database, the call sequence is:

    sqlite3_open_v2()
    sqlite3_user_authenticate();
    /* Database is now usable */

To open an existing, encrypted, authentication-required database, the
call sequence is:

    sqlite3_open_v2();
    sqlite3_key_v2();
    sqlite3_user_authenticate();
    /* Database is now usable */

When opening a no-authentication-required database, the database
connection is treated as if it was authenticated as an admin user.

When ATTACH-ing new database files to a connection, each newly attached
database that is an authentication-required database is checked using
the same username and password as supplied to the main database.  If that
check fails, then the ATTACH command fails with an SQLITE_AUTH error.

The sqlite3_user_add() interface can be used (by an admin user only)
to create a new user.  When called on a no-authentication-required
database and when A is true, the sqlite3_user_add(D,U,P,N,A) routine
converts the database into an authentication-required database and
logs in the database connection D as user U with password P,N.
To convert a no-authentication-required database into an authentication-
required database, the isAdmin parameter must be true.  If
sqlite3_user_add(D,U,P,N,A) is called on a no-authentication-required
database and A is false, then the call fails with an SQLITE_AUTH error.

Any call to sqlite3_user_add() by a non-admin user results in an error.

Hence, to create a new, unencrypted, authentication-required database,
the call sequence is:

    sqlite3_open_v2();
    sqlite3_user_add();

And to create a new, encrypted, authentication-required database, the call
sequence is:

    sqlite3_open_v2();
    sqlite3_key_v2();
    sqlite3_user_add();

The sqlite3_user_delete() interface can be used (by an admin user only)
to delete a user.  The currently logged-in user cannot be deleted,
which guarantees that there is always an admin user and hence that
the database cannot be converted into a no-authentication-required
database.

The sqlite3_user_change() interface can be used to change a users
login credentials or admin privilege.  Any user can change their own
password.  Only an admin user can change another users login
credentials or admin privilege setting.  No user may change their own 
admin privilege setting.

The sqlite3_set_authorizer() callback is modified to take a 7th parameter
which is the username of the currently logged in user, or NULL for a
no-authentication-required database.

-----------------------------------------------------------------------------
Implementation notes:

An authentication-required database is identified by the presence of a
new table:

    CREATE TABLE sqlite_user(
      uname TEXT PRIMARY KEY,
      isAdmin BOOLEAN,
      pw BLOB
    ) WITHOUT ROWID;

The sqlite_user table is inaccessible (unreadable and unwriteable) to
non-admin users and is read-only for admin users.  However, if the same
database file is opened by a version of SQLite that omits
the -DSQLITE_USER_AUTHENTICATION compile-time option, then the sqlite_user
table will be readable by anybody and writeable by anybody if
the "PRAGMA writable_schema=ON" statement is run first.

The sqlite_user.pw field is encoded by a built-in SQL function
"sqlite_crypt(X,Y)".  The two arguments are both BLOBs.  The first argument
is the plaintext password supplied to the sqlite3_user_authenticate()
interface.  The second argument is the sqlite_user.pw value and is supplied
so that the function can extract the "salt" used by the password encoder.
The result of sqlite_crypt(X,Y) is another blob which is the value that
ends up being stored in sqlite_user.pw.  To verify credentials X supplied
by the sqlite3_user_authenticate() routine, SQLite runs:

    sqlite_user.pw == sqlite_crypt(X, sqlite_user.pw)

To compute an appropriate sqlite_user.pw value from a new or modified
password X, sqlite_crypt(X,NULL) is run.  A new random salt is selected
when the second argument is NULL.

The built-in version of of sqlite_crypt() uses a simple Ceasar-cypher
which prevents passwords from being revealed by searching the raw database
for ASCII text, but is otherwise trivally broken.  For better password
security, the database should be encrypted using the SQLite Encryption
Extension or similar technology.  Or, the application can use the
sqlite3_create_function() interface to provide an alternative
implementation of sqlite_crypt() that computes a stronger password hash,
perhaps using a cryptographic hash function like SHA1.

/*
** 2014-09-08
**
** 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 the bulk of the implementation of the
** user-authentication extension feature.  Some parts of the user-
** authentication code are contained within the SQLite core (in the
** src/ subdirectory of the main source code tree) but those parts
** that could reasonable be separated out are moved into this file.
**
** To compile with the user-authentication feature, append this file to
** end of an SQLite amalgamation, then add the SQLITE_USER_AUTHENTICATION
** compile-time option.  See the user-auth.txt file in the same source
** directory as this file for additional information.
*/
#ifdef SQLITE_USER_AUTHENTICATION
#ifndef _SQLITEINT_H_
# include "sqliteInt.h"
#endif

/*
** Prepare an SQL statement for use by the user authentication logic.
** Return a pointer to the prepared statement on success.  Return a
** NULL pointer if there is an error of any kind.
*/
static sqlite3_stmt *sqlite3UserAuthPrepare(
  sqlite3 *db,
  const char *zFormat,
  ...
){
  sqlite3_stmt *pStmt;
  char *zSql;
  int rc;
  va_list ap;
  int savedFlags = db->flags;

  va_start(ap, zFormat);
  zSql = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
  if( zSql==0 ) return 0;
  db->flags |= SQLITE_WriteSchema;
  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
  db->flags = savedFlags;
  sqlite3_free(zSql);
  if( rc ){
    sqlite3_finalize(pStmt);
    pStmt = 0;
  }
  return pStmt;
}

/*
** Check to see if the sqlite_user table exists in database zDb.
*/
static int userTableExists(sqlite3 *db, const char *zDb){
  int rc;
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  if( db->init.busy==0 ){
    char *zErr = 0;
    sqlite3Init(db, &zErr);
    sqlite3DbFree(db, zErr);
  }
  rc = sqlite3FindTable(db, "sqlite_user", zDb)!=0;
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Check to see if database zDb has a "sqlite_user" table and if it does
** whether that table can authenticate zUser with nPw,zPw.  Write one of
** the UAUTH_* user authorization level codes into *peAuth and return a
** result code.
*/
static int userAuthCheckLogin(
  sqlite3 *db,               /* The database connection to check */
  const char *zDb,           /* Name of specific database to check */
  u8 *peAuth                 /* OUT: One of UAUTH_* constants */
){
  sqlite3_stmt *pStmt;
  int rc;

  *peAuth = UAUTH_Unknown;
  if( !userTableExists(db, "main") ){
    *peAuth = UAUTH_Admin;  /* No sqlite_user table.  Everybody is admin. */
    return SQLITE_OK;
  }
  if( db->auth.zAuthUser==0 ){
    *peAuth = UAUTH_Fail;
    return SQLITE_OK;
  }
  pStmt = sqlite3UserAuthPrepare(db,
            "SELECT pw=sqlite_crypt(?1,pw), isAdmin FROM \"%w\".sqlite_user"
            " WHERE uname=?2", zDb);
  if( pStmt==0 ) return SQLITE_NOMEM;
  sqlite3_bind_blob(pStmt, 1, db->auth.zAuthPW, db->auth.nAuthPW,SQLITE_STATIC);
  sqlite3_bind_text(pStmt, 2, db->auth.zAuthUser, -1, SQLITE_STATIC);
  rc = sqlite3_step(pStmt);
  if( rc==SQLITE_ROW && sqlite3_column_int(pStmt,0) ){
    *peAuth = sqlite3_column_int(pStmt, 1) + UAUTH_User;
  }else{
    *peAuth = UAUTH_Fail;
  }
  return sqlite3_finalize(pStmt);
}
int sqlite3UserAuthCheckLogin(
  sqlite3 *db,               /* The database connection to check */
  const char *zDb,           /* Name of specific database to check */
  u8 *peAuth                 /* OUT: One of UAUTH_* constants */
){
  int rc;
  u8 savedAuthLevel;
  assert( zDb!=0 );
  assert( peAuth!=0 );
  savedAuthLevel = db->auth.authLevel;
  db->auth.authLevel = UAUTH_Admin;
  rc = userAuthCheckLogin(db, zDb, peAuth);
  db->auth.authLevel = savedAuthLevel;
  return rc;
}

/*
** If the current authLevel is UAUTH_Unknown, the take actions to figure
** out what authLevel should be
*/
void sqlite3UserAuthInit(sqlite3 *db){
  if( db->auth.authLevel==UAUTH_Unknown ){
    u8 authLevel = UAUTH_Fail;
    sqlite3UserAuthCheckLogin(db, "main", &authLevel);
    db->auth.authLevel = authLevel;
    if( authLevel<UAUTH_Admin ) db->flags &= ~SQLITE_WriteSchema;
  }
}

/*
** Implementation of the sqlite_crypt(X,Y) function.
**
** If Y is NULL then generate a new hash for password X and return that
** hash.  If Y is not null, then generate a hash for password X using the
** same salt as the previous hash Y and return the new hash.
*/
void sqlite3CryptFunc(
  sqlite3_context *context,
  int NotUsed,
  sqlite3_value **argv
){
  const char *zIn;
  int nIn, ii;
  u8 *zOut;
  char zSalt[8];
  zIn = sqlite3_value_blob(argv[0]);
  nIn = sqlite3_value_bytes(argv[0]);
  if( sqlite3_value_type(argv[1])==SQLITE_BLOB
   && sqlite3_value_bytes(argv[1])==nIn+sizeof(zSalt)
  ){
    memcpy(zSalt, sqlite3_value_blob(argv[1]), sizeof(zSalt));
  }else{
    sqlite3_randomness(sizeof(zSalt), zSalt);
  }
  zOut = sqlite3_malloc( nIn+sizeof(zSalt) );
  if( zOut==0 ){
    sqlite3_result_error_nomem(context);
  }else{
    memcpy(zOut, zSalt, sizeof(zSalt));
    for(ii=0; ii<nIn; ii++){
      zOut[ii+sizeof(zSalt)] = zIn[ii]^zSalt[ii&0x7];
    }
    sqlite3_result_blob(context, zOut, nIn+sizeof(zSalt), sqlite3_free);
  }
}

/*
** If a database contains the SQLITE_USER table, then the
** sqlite3_user_authenticate() interface must be invoked with an
** appropriate username and password prior to enable read and write
** access to the database.
**
** Return SQLITE_OK on success or SQLITE_ERROR if the username/password
** combination is incorrect or unknown.
**
** If the SQLITE_USER table is not present in the database file, then
** this interface is a harmless no-op returnning SQLITE_OK.
*/
int sqlite3_user_authenticate(
  sqlite3 *db,           /* The database connection */
  const char *zUsername, /* Username */
  const char *zPW,       /* Password or credentials */
  int nPW                /* Number of bytes in aPW[] */
){
  int rc;
  u8 authLevel = UAUTH_Fail;
  db->auth.authLevel = UAUTH_Unknown;
  sqlite3_free(db->auth.zAuthUser);
  sqlite3_free(db->auth.zAuthPW);
  memset(&db->auth, 0, sizeof(db->auth));
  db->auth.zAuthUser = sqlite3_mprintf("%s", zUsername);
  if( db->auth.zAuthUser==0 ) return SQLITE_NOMEM;
  db->auth.zAuthPW = sqlite3_malloc( nPW+1 );
  if( db->auth.zAuthPW==0 ) return SQLITE_NOMEM;
  memcpy(db->auth.zAuthPW,zPW,nPW);
  db->auth.nAuthPW = nPW;
  rc = sqlite3UserAuthCheckLogin(db, "main", &authLevel);
  db->auth.authLevel = authLevel;
  sqlite3ExpirePreparedStatements(db);
  if( rc ){
    return rc;           /* OOM error, I/O error, etc. */
  }
  if( authLevel<UAUTH_User ){
    return SQLITE_AUTH;  /* Incorrect username and/or password */
  }
  return SQLITE_OK;      /* Successful login */
}

/*
** The sqlite3_user_add() interface can be used (by an admin user only)
** to create a new user.  When called on a no-authentication-required
** database, this routine converts the database into an authentication-
** required database, automatically makes the added user an
** administrator, and logs in the current connection as that user.
** The sqlite3_user_add() interface only works for the "main" database, not
** for any ATTACH-ed databases.  Any call to sqlite3_user_add() by a
** non-admin user results in an error.
*/
int sqlite3_user_add(
  sqlite3 *db,           /* Database connection */
  const char *zUsername, /* Username to be added */
  const char *aPW,       /* Password or credentials */
  int nPW,               /* Number of bytes in aPW[] */
  int isAdmin            /* True to give new user admin privilege */
){
  sqlite3_stmt *pStmt;
  int rc;
  sqlite3UserAuthInit(db);
  if( db->auth.authLevel<UAUTH_Admin ) return SQLITE_AUTH;
  if( !userTableExists(db, "main") ){
    if( !isAdmin ) return SQLITE_AUTH;
    pStmt = sqlite3UserAuthPrepare(db, 
              "CREATE TABLE sqlite_user(\n"
              "  uname TEXT PRIMARY KEY,\n"
              "  isAdmin BOOLEAN,\n"
              "  pw BLOB\n"
              ") WITHOUT ROWID;");
    if( pStmt==0 ) return SQLITE_NOMEM;
    sqlite3_step(pStmt);
    rc = sqlite3_finalize(pStmt);
    if( rc ) return rc;
  }
  pStmt = sqlite3UserAuthPrepare(db, 
            "INSERT INTO sqlite_user(uname,isAdmin,pw)"
            " VALUES(%Q,%d,sqlite_crypt(?1,NULL))",
            zUsername, isAdmin!=0);
  if( pStmt==0 ) return SQLITE_NOMEM;
  sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);
  sqlite3_step(pStmt);
  rc = sqlite3_finalize(pStmt);
  if( rc ) return rc;
  if( db->auth.zAuthUser==0 ){
    assert( isAdmin!=0 );
    sqlite3_user_authenticate(db, zUsername, aPW, nPW);
  }
  return SQLITE_OK;
}

/*
** The sqlite3_user_change() interface can be used to change a users
** login credentials or admin privilege.  Any user can change their own
** login credentials.  Only an admin user can change another users login
** credentials or admin privilege setting.  No user may change their own 
** admin privilege setting.
*/
int sqlite3_user_change(
  sqlite3 *db,           /* Database connection */
  const char *zUsername, /* Username to change */
  const char *aPW,       /* Modified password or credentials */
  int nPW,               /* Number of bytes in aPW[] */
  int isAdmin            /* Modified admin privilege for the user */
){
  sqlite3_stmt *pStmt;
  int rc;
  u8 authLevel;

  authLevel = db->auth.authLevel;
  if( authLevel<UAUTH_User ){
    /* Must be logged in to make a change */
    return SQLITE_AUTH;
  }
  if( strcmp(db->auth.zAuthUser, zUsername)!=0 ){
    if( db->auth.authLevel<UAUTH_Admin ){
      /* Must be an administrator to change a different user */
      return SQLITE_AUTH;
    }
  }else if( isAdmin!=(authLevel==UAUTH_Admin) ){
    /* Cannot change the isAdmin setting for self */
    return SQLITE_AUTH;
  }
  db->auth.authLevel = UAUTH_Admin;
  if( !userTableExists(db, "main") ){
    /* This routine is a no-op if the user to be modified does not exist */
  }else{
    pStmt = sqlite3UserAuthPrepare(db,
              "UPDATE sqlite_user SET isAdmin=%d, pw=sqlite_crypt(?1,NULL)"
              " WHERE uname=%Q", isAdmin, zUsername);
    if( pStmt==0 ){
      rc = SQLITE_NOMEM;
    }else{
      sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);
      sqlite3_step(pStmt);
      rc = sqlite3_finalize(pStmt);
    }
  }
  db->auth.authLevel = authLevel;
  return rc;
}

/*
** The sqlite3_user_delete() interface can be used (by an admin user only)
** to delete a user.  The currently logged-in user cannot be deleted,
** which guarantees that there is always an admin user and hence that
** the database cannot be converted into a no-authentication-required
** database.
*/
int sqlite3_user_delete(
  sqlite3 *db,           /* Database connection */
  const char *zUsername  /* Username to remove */
){
  sqlite3_stmt *pStmt;
  if( db->auth.authLevel<UAUTH_Admin ){
    /* Must be an administrator to delete a user */
    return SQLITE_AUTH;
  }
  if( strcmp(db->auth.zAuthUser, zUsername)==0 ){
    /* Cannot delete self */
    return SQLITE_AUTH;
  }
  if( !userTableExists(db, "main") ){
    /* This routine is a no-op if the user to be deleted does not exist */
    return SQLITE_OK;
  }
  pStmt = sqlite3UserAuthPrepare(db,
              "DELETE FROM sqlite_user WHERE uname=%Q", zUsername);
  if( pStmt==0 ) return SQLITE_NOMEM;
  sqlite3_step(pStmt);
  return sqlite3_finalize(pStmt);
}

#endif /* SQLITE_USER_AUTHENTICATION */

# build the SQLite library and testing tools.
################################################################################

# This is how we compile
#
TCCX =  $(TCC) $(OPTS) -I. -I$(TOP)/src -I$(TOP) 
TCCX += -I$(TOP)/ext/rtree -I$(TOP)/ext/icu -I$(TOP)/ext/fts3
TCCX += -I$(TOP)/ext/async -I$(TOP)/ext/userauth

# Object files for the SQLite library.
#
LIBOBJ+= vdbe.o parse.o \
         alter.o analyze.o attach.o auth.o \
         backup.o bitvec.o btmutex.o btree.o build.o \
         callback.o complete.o ctime.o date.o delete.o expr.o fault.o fkey.o \
         fts3.o fts3_aux.o fts3_expr.o fts3_hash.o fts3_icu.o fts3_porter.o \
         fts3_snippet.o fts3_tokenizer.o fts3_tokenizer1.o \
         fts3_tokenize_vtab.o \
	 fts3_unicode.o fts3_unicode2.o \
         fts3_write.o func.o global.o hash.o \
         icu.o insert.o journal.o legacy.o loadext.o \
         main.o malloc.o mem0.o mem1.o mem2.o mem3.o mem5.o \
         memjournal.o \
         mutex.o mutex_noop.o mutex_unix.o mutex_w32.o \
         notify.o opcodes.o os.o os_unix.o os_win.o \
         pager.o pcache.o pcache1.o pragma.o prepare.o printf.o \
         random.o resolve.o rowset.o rtree.o select.o status.o \
         table.o threads.o tokenize.o trigger.o \
         update.o userauth.o util.o vacuum.o \
         vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbesort.o \
	 vdbetrace.o wal.o walker.o where.o utf.o vtab.o



# All of the source code files.
#

SRC += \
  $(TOP)/ext/icu/sqliteicu.h \
  $(TOP)/ext/icu/icu.c
SRC += \
  $(TOP)/ext/rtree/sqlite3rtree.h \
  $(TOP)/ext/rtree/rtree.h \
  $(TOP)/ext/rtree/rtree.c
SRC += \
  $(TOP)/ext/userauth/userauth.c \
  $(TOP)/ext/userauth/sqlite3userauth.h

# Generated source code files
#
SRC += \
  keywordhash.h \
  opcodes.c \
  opcodes.h \

  $(TOP)/ext/fts3/fts3Int.h \
  $(TOP)/ext/fts3/fts3_hash.h \
  $(TOP)/ext/fts3/fts3_tokenizer.h
EXTHDR += \
  $(TOP)/ext/rtree/rtree.h
EXTHDR += \
  $(TOP)/ext/icu/sqliteicu.h
EXTHDR += \
  $(TOP)/ext/userauth/sqlite3userauth.h

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	sqlite3.h libsqlite3.a sqlite3$(EXE)

libsqlite3.a:	$(LIBOBJ)

	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_unicode2.c

fts3_write.o:	$(TOP)/ext/fts3/fts3_write.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_write.c

rtree.o:	$(TOP)/ext/rtree/rtree.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/rtree/rtree.c

userauth.o:	$(TOP)/ext/userauth/userauth.c $(HDR) $(EXTHDR)
	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/userauth/userauth.c


# Rules for building test programs and for running tests
#
tclsqlite3:	$(TOP)/src/tclsqlite.c libsqlite3.a
	$(TCCX) $(TCL_FLAGS) -DTCLSH=1 -o tclsqlite3 \
		$(TOP)/src/tclsqlite.c libsqlite3.a $(LIBTCL) $(THREADLIB)

  int len = 0;
  char *zRet;
  sqlite3 *db = sqlite3_context_db_handle(context);

  UNUSED_PARAMETER(NotUsed);

  /* The principle used to locate the table name in the CREATE TRIGGER 
  ** statement is that the table name is the first token that is immediately
  ** preceded by either TK_ON or TK_DOT and immediately followed by one
  ** of TK_WHEN, TK_BEGIN or TK_FOR.
  */
  if( zSql ){
    do {

      if( !*zCsr ){
        /* Ran out of input before finding the table name. Return NULL. */

** SQLITE_ENABLE_STAT3 defined.  The functionality of sqlite_stat3
** is a superset of sqlite_stat2.  The sqlite_stat4 is an enhanced
** version of sqlite_stat3 and is only available when compiled with
** SQLITE_ENABLE_STAT4 and in SQLite versions 3.8.1 and later.  It is
** not possible to enable both STAT3 and STAT4 at the same time.  If they
** are both enabled, then STAT4 takes precedence.
**
** For most applications, sqlite_stat1 provides all the statistics required
** for the query planner to make good choices.
**
** Format of sqlite_stat1:
**
** There is normally one row per index, with the index identified by the
** name in the idx column.  The tbl column is the name of the table to
** which the index belongs.  In each such row, the stat column will be

**
** For indexes on ordinary rowid tables, N==K+1.  But for indexes on
** WITHOUT ROWID tables, N=K+P where P is the number of columns in the
** PRIMARY KEY of the table.  The covering index that implements the
** original WITHOUT ROWID table as N==K as a special case.
**
** This routine allocates the Stat4Accum object in heap memory. The return 
** value is a pointer to the Stat4Accum object.  The datatype of the
** return value is BLOB, but it is really just a pointer to the Stat4Accum
** object.
*/
static void statInit(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv

      tRowcnt nSum = 0;         /* Number of terms contributing to sumEq */
      tRowcnt avgEq = 0;
      tRowcnt nDLt = pFinal->anDLt[iCol];

      /* Set nSum to the number of distinct (iCol+1) field prefixes that
      ** occur in the stat4 table for this index before pFinal. Set
      ** sumEq to the sum of the nEq values for column iCol for the same
      ** set (adding the value only once where there exist duplicate 
      ** prefixes).  */
      for(i=0; i<(pIdx->nSample-1); i++){
        if( aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol] ){
          sumEq += aSample[i].anEq[iCol];
          nSum++;
        }
      }

  ** we found it.
  */
  if( rc==SQLITE_OK ){
    sqlite3BtreeEnterAll(db);
    rc = sqlite3Init(db, &zErrDyn);
    sqlite3BtreeLeaveAll(db);
  }
#ifdef SQLITE_USER_AUTHENTICATION
  if( rc==SQLITE_OK ){
    u8 newAuth = 0;
    rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth);
    if( newAuth<db->auth.authLevel ){
      rc = SQLITE_AUTH_USER;
    }
  }
#endif
  if( rc ){
    int iDb = db->nDb - 1;
    assert( iDb>=2 );
    if( db->aDb[iDb].pBt ){
      sqlite3BtreeClose(db->aDb[iDb].pBt);
      db->aDb[iDb].pBt = 0;
      db->aDb[iDb].pSchema = 0;

*/
int sqlite3_set_authorizer(
  sqlite3 *db,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pArg
){
  sqlite3_mutex_enter(db->mutex);
  db->xAuth = (sqlite3_xauth)xAuth;
  db->pAuthArg = pArg;
  sqlite3ExpirePreparedStatements(db);
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*

  const char *zCol,               /* Column name */
  int iDb                         /* Index of containing database. */
){
  sqlite3 *db = pParse->db;       /* Database handle */
  char *zDb = db->aDb[iDb].zName; /* Name of attached database */
  int rc;                         /* Auth callback return code */

  rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext
#ifdef SQLITE_USER_AUTHENTICATION
                 ,db->auth.zAuthUser
#endif
                );
  if( rc==SQLITE_DENY ){
    if( db->nDb>2 || iDb!=0 ){
      sqlite3ErrorMsg(pParse, "access to %s.%s.%s is prohibited",zDb,zTab,zCol);
    }else{
      sqlite3ErrorMsg(pParse, "access to %s.%s is prohibited", zTab, zCol);
    }
    pParse->rc = SQLITE_AUTH;

  if( db->init.busy || IN_DECLARE_VTAB ){
    return SQLITE_OK;
  }

  if( db->xAuth==0 ){
    return SQLITE_OK;
  }
  rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext
#ifdef SQLITE_USER_AUTHENTICATION
                 ,db->auth.zAuthUser
#endif
                );
  if( rc==SQLITE_DENY ){
    sqlite3ErrorMsg(pParse, "not authorized");
    pParse->rc = SQLITE_AUTH;
  }else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
    rc = SQLITE_DENY;
    sqliteAuthBadReturnCode(pParse);
  }

** and thus help the sqlite3BtreeLock() routine to run much faster
** in the common case.
*/
static void SQLITE_NOINLINE btreeLockCarefully(Btree *p){
  Btree *pLater;

  /* In most cases, we should be able to acquire the lock we
  ** want without having to go through the ascending lock
  ** procedure that follows.  Just be sure not to block.
  */
  if( sqlite3_mutex_try(p->pBt->mutex)==SQLITE_OK ){
    p->pBt->db = p->db;
    p->locked = 1;
    return;
  }

/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file implements an external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

/*
** The header string that appears at the beginning of every

  /* If this is an intKey table, then the above call to BtreeKeySize()
  ** stores the integer key in pCur->nKey. In this case this value is
  ** all that is required. Otherwise, if pCur is not open on an intKey
  ** table, then malloc space for and store the pCur->nKey bytes of key 
  ** data.
  */
  if( 0==pCur->apPage[0]->intKey ){
    void *pKey = sqlite3Malloc( pCur->nKey );
    if( pKey ){
      rc = sqlite3BtreeKey(pCur, 0, (int)pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }

** Defragment the page given.  All Cells are moved to the
** end of the page and all free space is collected into one
** big FreeBlk that occurs in between the header and cell
** pointer array and the cell content area.
*/
static int defragmentPage(MemPage *pPage){
  int i;                     /* Loop counter */
  int pc;                    /* Address of the i-th cell */
  int hdr;                   /* Offset to the page header */
  int size;                  /* Size of a cell */
  int usableSize;            /* Number of usable bytes on a page */
  int cellOffset;            /* Offset to the cell pointer array */
  int cbrk;                  /* Offset to the cell content area */
  int nCell;                 /* Number of cells on the page */
  unsigned char *data;       /* The page data */

** in assert() expressions, so it is only compiled if NDEBUG is not
** defined.
**
** Only write cursors are counted if wrOnly is true.  If wrOnly is
** false then all cursors are counted.
**
** For the purposes of this routine, a cursor is any cursor that
** is capable of reading or writing to the database.  Cursors that
** have been tripped into the CURSOR_FAULT state are not counted.
*/
static int countValidCursors(BtShared *pBt, int wrOnly){
  BtCursor *pCur;
  int r = 0;
  for(pCur=pBt->pCursor; pCur; pCur=pCur->pNext){
    if( (wrOnly==0 || (pCur->curFlags & BTCF_WriteFlag)!=0)

/*
** Perform a single step of an incremental-vacuum. If successful, return
** SQLITE_OK. If there is no work to do (and therefore no point in 
** calling this function again), return SQLITE_DONE. Or, if an error 
** occurs, return some other error code.
**
** More specifically, this function attempts to re-organize the database so 
** that the last page of the file currently in use is no longer in use.
**
** Parameter nFin is the number of pages that this database would contain
** were this function called until it returns SQLITE_DONE.
**
** If the bCommit parameter is non-zero, this function assumes that the 
** caller will keep calling incrVacuumStep() until it returns SQLITE_DONE 
** or an error. bCommit is passed true for an auto-vacuum-on-commit 
** operation, or false for an incremental vacuum.
*/
static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg, int bCommit){
  Pgno nFreeList;           /* Number of pages still on the free-list */
  int rc;

  assert( sqlite3_mutex_held(pBt->mutex) );

  btreeEndTransaction(p);
  sqlite3BtreeLeave(p);
  return rc;
}

/*
** Start a statement subtransaction. The subtransaction can be rolled
** back independently of the main transaction. You must start a transaction 
** before starting a subtransaction. The subtransaction is ended automatically 
** if the main transaction commits or rolls back.
**
** Statement subtransactions are used around individual SQL statements
** that are contained within a BEGIN...COMMIT block.  If a constraint
** error occurs within the statement, the effect of that one statement

** BtCursor.info is a cache of the information in the current cell.
** Using this cache reduces the number of calls to btreeParseCell().
**
** 2007-06-25:  There is a bug in some versions of MSVC that cause the
** compiler to crash when getCellInfo() is implemented as a macro.
** But there is a measureable speed advantage to using the macro on gcc
** (when less compiler optimizations like -Os or -O0 are used and the
** compiler is not doing aggressive inlining.)  So we use a real function
** for MSVC and a macro for everything else.  Ticket #2457.
*/
#ifndef NDEBUG
  static void assertCellInfo(BtCursor *pCur){
    CellInfo info;
    int iPage = pCur->iPage;
    memset(&info, 0, sizeof(info));

** Data is read to or from the buffer pBuf.
**
** The content being read or written might appear on the main page
** or be scattered out on multiple overflow pages.
**
** If the current cursor entry uses one or more overflow pages and the
** eOp argument is not 2, this function may allocate space for and lazily 
** populates the overflow page-list cache array (BtCursor.aOverflow). 
** Subsequent calls use this cache to make seeking to the supplied offset 
** more efficient.
**
** Once an overflow page-list cache has been allocated, it may be
** invalidated if some other cursor writes to the same table, or if
** the cursor is moved to a different row. Additionally, in auto-vacuum
** mode, the following events may invalidate an overflow page-list cache.

    return SQLITE_CORRUPT_BKPT;
  }
  return rc;
}

/*
** Read part of the key associated with cursor pCur.  Exactly
** "amt" bytes will be transferred into pBuf[].  The transfer
** begins at "offset".
**
** The caller must ensure that pCur is pointing to a valid row
** in the table.
**
** Return SQLITE_OK on success or an error code if anything goes
** wrong.  An error is returned if "offset+amt" is larger than

}

/*
** Add a list of cells to a page.  The page should be initially empty.
** The cells are guaranteed to fit on the page.
*/
static void assemblePage(
  MemPage *pPage,   /* The page to be assembled */
  int nCell,        /* The number of cells to add to this page */
  u8 **apCell,      /* Pointers to cell bodies */
  u16 *aSize        /* Sizes of the cells */
){
  int i;            /* Loop counter */
  u8 *pCellptr;     /* Address of next cell pointer */
  int cellbody;     /* Address of next cell body */

    if( rc ) goto balance_cleanup;
    releasePage(apOld[i]);
    apOld[i] = 0;
    i++;
  }

  /*
  ** Put the new pages in ascending order.  This helps to
  ** keep entries in the disk file in order so that a scan
  ** of the table is a linear scan through the file.  That
  ** in turn helps the operating system to deliver pages
  ** from the disk more rapidly.
  **
  ** An O(n^2) insertion sort algorithm is used, but since
  ** n is never more than NB (a small constant), that should

         && pPage->aiOvfl[0]==pPage->nCell
         && pParent->pgno!=1
         && pParent->nCell==iIdx
        ){
          /* Call balance_quick() to create a new sibling of pPage on which
          ** to store the overflow cell. balance_quick() inserts a new cell
          ** into pParent, which may cause pParent overflow. If this
          ** happens, the next iteration of the do-loop will balance pParent 
          ** use either balance_nonroot() or balance_deeper(). Until this
          ** happens, the overflow cell is stored in the aBalanceQuickSpace[]
          ** buffer. 
          **
          ** The purpose of the following assert() is to check that only a
          ** single call to balance_quick() is made for each call to this
          ** function. If this were not verified, a subtle bug involving reuse

** For an INTKEY table, only the nKey value of the key is used.  pKey is
** ignored.  For a ZERODATA table, the pData and nData are both ignored.
**
** If the seekResult parameter is non-zero, then a successful call to
** MovetoUnpacked() to seek cursor pCur to (pKey, nKey) has already
** been performed. seekResult is the search result returned (a negative
** number if pCur points at an entry that is smaller than (pKey, nKey), or
** a positive value if pCur points at an entry that is larger than 
** (pKey, nKey)). 
**
** If the seekResult parameter is non-zero, then the caller guarantees that
** cursor pCur is pointing at the existing copy of a row that is to be
** overwritten.  If the seekResult parameter is 0, then cursor pCur may
** point to any entry or to no entry at all and so this function has to seek
** the cursor before the new key can be inserted.

end_insert:
  return rc;
}

/*
** Delete the entry that the cursor is pointing to.  The cursor
** is left pointing at an arbitrary location.
*/
int sqlite3BtreeDelete(BtCursor *pCur){
  Btree *p = pCur->pBtree;
  BtShared *pBt = p->pBt;              
  int rc;                              /* Return code */
  MemPage *pPage;                      /* Page to delete cell from */
  unsigned char *pCell;                /* Pointer to cell to delete */

  pCheck->aPgRef[iPg/8] |= (1 << (iPg & 0x07));
}


/*
** Add 1 to the reference count for page iPage.  If this is the second
** reference to the page, add an error message to pCheck->zErrMsg.
** Return 1 if there are 2 or more references to the page and 0 if
** if this is the first reference to the page.
**
** Also check that the page number is in bounds.
*/
static int checkRef(IntegrityCk *pCheck, Pgno iPage, char *zContext){
  if( iPage==0 ) return 1;
  if( iPage>pCheck->nPage ){

/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file implements an external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
**
** The basic idea is that each page of the file contains N database

**      3       2      number of cells on this page
**      5       2      first byte of the cell content area
**      7       1      number of fragmented free bytes
**      8       4      Right child (the Ptr(N) value).  Omitted on leaves.
**
** The flags define the format of this btree page.  The leaf flag means that
** this page has no children.  The zerodata flag means that this page carries
** only keys and no data.  The intkey flag means that the key is an integer
** which is stored in the key size entry of the cell header rather than in
** the payload area.
**
** The cell pointer array begins on the first byte after the page header.
** The cell pointer array contains zero or more 2-byte numbers which are
** offsets from the beginning of the page to the cell content in the cell
** content area.  The cell pointers occur in sorted order.  The system strives

**   The table that this cursor was opened on still exists, but has been 
**   modified since the cursor was last used. The cursor position is saved
**   in variables BtCursor.pKey and BtCursor.nKey. When a cursor is in 
**   this state, restoreCursorPosition() can be called to attempt to
**   seek the cursor to the saved position.
**
** CURSOR_FAULT:
**   An unrecoverable error (an I/O error or a malloc failure) has occurred
**   on a different connection that shares the BtShared cache with this
**   cursor.  The error has left the cache in an inconsistent state.
**   Do nothing else with this cursor.  Any attempt to use the cursor
**   should return the error code stored in BtCursor.skip
*/
#define CURSOR_INVALID           0
#define CURSOR_VALID             1

  */
  v = sqlite3GetVdbe(pParse);
  assert( !pParse->isMultiWrite 
       || sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));
  if( v ){
    while( sqlite3VdbeDeletePriorOpcode(v, OP_Close) ){}
    sqlite3VdbeAddOp0(v, OP_Halt);

#if SQLITE_USER_AUTHENTICATION
    if( pParse->nTableLock>0 && db->init.busy==0 ){
      sqlite3UserAuthInit(db);
      if( db->auth.authLevel<UAUTH_User ){
        pParse->rc = SQLITE_AUTH_USER;
        sqlite3ErrorMsg(pParse, "user not authenticated");
        return;
      }
    }
#endif

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */

  sqlite3RunParser(pParse, zSql, &zErrMsg);
  sqlite3DbFree(db, zErrMsg);
  sqlite3DbFree(db, zSql);
  memcpy(&pParse->nVar, saveBuf, SAVE_SZ);
  pParse->nested--;
}

#if SQLITE_USER_AUTHENTICATION
/*
** Return TRUE if zTable is the name of the system table that stores the
** list of users and their access credentials.
*/
int sqlite3UserAuthTable(const char *zTable){
  return sqlite3_stricmp(zTable, "sqlite_user")==0;
}
#endif

/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table.  Return NULL if not found.
**
** If zDatabase is 0, all databases are searched for the table and the
** first matching table is returned.  (No checking for duplicate table
** names is done.)  The search order is TEMP first, then MAIN, then any
** auxiliary databases added using the ATTACH command.
**
** See also sqlite3LocateTable().
*/
Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
  Table *p = 0;
  int i;
  assert( zName!=0 );
  /* All mutexes are required for schema access.  Make sure we hold them. */
  assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
#if SQLITE_USER_AUTHENTICATION
  /* Only the admin user is allowed to know that the sqlite_user table
  ** exists */
  if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
    return 0;
  }
#endif
  for(i=OMIT_TEMPDB; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;   /* Search TEMP before MAIN */
    if( zDatabase!=0 && sqlite3StrICmp(zDatabase, db->aDb[j].zName) ) continue;
    assert( sqlite3SchemaMutexHeld(db, j, 0) );
    p = sqlite3HashFind(&db->aDb[j].pSchema->tblHash, zName);
    if( p ) break;
  }

    if( zDbase ){
      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
    }else{
      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
    }
    pParse->checkSchema = 1;
  }
#if SQLITE_USER_AUTHENICATION
  else if( pParse->db->auth.authLevel<UAUTH_User ){
    sqlite3ErrorMsg(pParse, "user not authenticated");
    p = 0;
  }
#endif
  return p;
}

/*
** Locate the table identified by *p.
**
** This is a wrapper around sqlite3LocateTable(). The difference between

** are appropriate for a WITHOUT ROWID table instead of a rowid table.
** Changes include:
**
**     (1)  Convert the OP_CreateTable into an OP_CreateIndex.  There is
**          no rowid btree for a WITHOUT ROWID.  Instead, the canonical
**          data storage is a covering index btree.
**     (2)  Bypass the creation of the sqlite_master table entry
**          for the PRIMARY KEY as the primary key index is now
**          identified by the sqlite_master table entry of the table itself.
**     (3)  Set the Index.tnum of the PRIMARY KEY Index object in the
**          schema to the rootpage from the main table.
**     (4)  Set all columns of the PRIMARY KEY schema object to be NOT NULL.
**     (5)  Add all table columns to the PRIMARY KEY Index object
**          so that the PRIMARY KEY is a covering index.  The surplus
**          columns are part of KeyInfo.nXField and are not used for
**          sorting or lookup or uniqueness checks.
**     (6)  Replace the rowid tail on all automatically generated UNIQUE
**          indices with the PRIMARY KEY columns.
*/
static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
  Index *pIdx;
  Index *pPk;
  int nPk;
  int i, j;
  sqlite3 *db = pParse->db;
  Vdbe *v = pParse->pVdbe;

  /* Convert the OP_CreateTable opcode that would normally create the
  ** root-page for the table into an OP_CreateIndex opcode.  The index
  ** created will become the PRIMARY KEY index.
  */
  if( pParse->addrCrTab ){
    assert( v );
    sqlite3VdbeGetOp(v, pParse->addrCrTab)->opcode = OP_CreateIndex;
  }

*/
int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
  Table *pSelTab;   /* A fake table from which we get the result set */
  Select *pSel;     /* Copy of the SELECT that implements the view */
  int nErr = 0;     /* Number of errors encountered */
  int n;            /* Temporarily holds the number of cursors assigned */
  sqlite3 *db = pParse->db;  /* Database connection for malloc errors */
  sqlite3_xauth xAuth;       /* Saved xAuth pointer */

  assert( pTable );

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( sqlite3VtabCallConnect(pParse, pTable) ){
    return SQLITE_ERROR;
  }

  int iSorter;                   /* Cursor opened by OpenSorter (if in use) */
  int addr1;                     /* Address of top of loop */
  int addr2;                     /* Address to jump to for next iteration */
  int tnum;                      /* Root page of index */
  int iPartIdxLabel;             /* Jump to this label to skip a row */
  Vdbe *v;                       /* Generate code into this virtual machine */
  KeyInfo *pKey;                 /* KeyInfo for index */
  int regRecord;                 /* Register holding assembled index record */
  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
      db->aDb[iDb].zName ) ){
    return;

    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  }
  pDb = &db->aDb[iDb];

  assert( pTab!=0 );
  assert( pParse->nErr==0 );
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 
       && db->init.busy==0
#if SQLITE_USER_AUTHENTICATION
       && sqlite3UserAuthTable(pTab->zName)==0
#endif
       && sqlite3StrNICmp(&pTab->zName[7],"altertab_",9)!=0 ){
    sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
    goto exit_create_index;
  }
#ifndef SQLITE_OMIT_VIEW
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "views may not be indexed");

  return pRet;
}

/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**
** aiRowEst[0] is supposed to contain the number of elements in the index.
** Since we do not know, guess 1 million.  aiRowEst[1] is an estimate of the
** number of rows in the table that match any particular value of the
** first column of the index.  aiRowEst[2] is an estimate of the number
** of rows that match any particular combination of the first 2 columns
** of the index.  And so forth.  It must always be the case that
*
**           aiRowEst[N]<=aiRowEst[N-1]

/*
** This routine is called by the parser to add a new term to the
** end of a growing FROM clause.  The "p" parameter is the part of
** the FROM clause that has already been constructed.  "p" is NULL
** if this is the first term of the FROM clause.  pTable and pDatabase
** are the name of the table and database named in the FROM clause term.
** pDatabase is NULL if the database name qualifier is missing - the
** usual case.  If the term has an alias, then pAlias points to the
** alias token.  If the term is a subquery, then pSubquery is the
** SELECT statement that the subquery encodes.  The pTable and
** pDatabase parameters are NULL for subqueries.  The pOn and pUsing
** parameters are the content of the ON and USING clauses.
**
** Return a new SrcList which encodes is the FROM with the new
** term added.

/*
** Locate and return an entry from the db.aCollSeq hash table. If the entry
** specified by zName and nName is not found and parameter 'create' is
** true, then create a new entry. Otherwise return NULL.
**
** Each pointer stored in the sqlite3.aCollSeq hash table contains an
** array of three CollSeq structures. The first is the collation sequence
** preferred for UTF-8, the second UTF-16le, and the third UTF-16be.
**
** Stored immediately after the three collation sequences is a copy of
** the collation sequence name. A pointer to this string is stored in
** each collation sequence structure.
*/
static CollSeq *findCollSeqEntry(
  sqlite3 *db,          /* Database connection */

**   (2) NORMAL    We are in the middle of statement which ends with a single
**                 semicolon.
**
**   (3) EXPLAIN   The keyword EXPLAIN has been seen at the beginning of 
**                 a statement.
**
**   (4) CREATE    The keyword CREATE has been seen at the beginning of a
**                 statement, possibly preceded by EXPLAIN and/or followed by
**                 TEMP or TEMPORARY
**
**   (5) TRIGGER   We are in the middle of a trigger definition that must be
**                 ended by a semicolon, the keyword END, and another semicolon.
**
**   (6) SEMI      We've seen the first semicolon in the ";END;" that occurs at
**                 the end of a trigger definition.
**
**   (7) END       We've seen the ";END" of the ";END;" that occurs at the end
**                 of a trigger definition.
**
** Transitions between states above are determined by tokens extracted
** from the input.  The following tokens are significant:
**
**   (0) tkSEMI      A semicolon.
**   (1) tkWS        Whitespace.
**   (2) tkOTHER     Any other SQL token.

     /* 4  CREATE: */ {    1,  4,     2,       2,      2,    4,       5,   2, },
     /* 5 TRIGGER: */ {    6,  5,     5,       5,      5,    5,       5,   5, },
     /* 6    SEMI: */ {    6,  6,     5,       5,      5,    5,       5,   7, },
     /* 7     END: */ {    1,  7,     5,       5,      5,    5,       5,   5, },
  };
#else
  /* If triggers are not supported by this compile then the statement machine
  ** used to detect the end of a statement is much simpler
  */
  static const u8 trans[3][3] = {
                     /* Token:           */
     /* State:       **  SEMI  WS  OTHER */
     /* 0 INVALID: */ {    1,  0,     2, },
     /* 1   START: */ {    1,  1,     2, },
     /* 2  NORMAL: */ {    1,  2,     2, },

  "TEST",
#endif
#if defined(SQLITE_THREADSAFE)
  "THREADSAFE=" CTIMEOPT_VAL(SQLITE_THREADSAFE),
#endif
#ifdef SQLITE_USE_ALLOCA
  "USE_ALLOCA",
#endif
#ifdef SQLITE_USER_AUTHENTICATION
  "USER_AUTHENTICATION",
#endif
#ifdef SQLITE_WIN32_MALLOC
  "WIN32_MALLOC",
#endif
#ifdef SQLITE_ZERO_MALLOC
  "ZERO_MALLOC"
#endif

** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system. 
**
** 1970-01-01 00:00:00 is JD 2440587.5
** 2000-01-01 00:00:00 is JD 2451544.5
**
** This implementation requires years to be expressed as a 4-digit number
** which means that only dates between 0000-01-01 and 9999-12-31 can
** be represented, even though julian day numbers allow a much wider
** range of dates.
**
** The Gregorian calendar system is used for all dates and times,
** even those that predate the Gregorian calendar.  Historians usually
** use the Julian calendar for dates prior to 1582-10-15 and for some

** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
void sqlite3MaterializeView(
  Parse *pParse,       /* Parsing context */
  Table *pView,        /* View definition */
  Expr *pWhere,        /* Optional WHERE clause to be added */
  int iCur             /* Cursor number for ephemeral table */
){
  SelectDest dest;
  Select *pSel;
  SrcList *pFrom;
  sqlite3 *db = pParse->db;
  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
  pWhere = sqlite3ExprDup(db, pWhere, 0);

  int iKey;              /* Memory cell holding key of row to be deleted */
  i16 nKey;              /* Number of memory cells in the row key */
  int iEphCur = 0;       /* Ephemeral table holding all primary key values */
  int iRowSet = 0;       /* Register for rowset of rows to delete */
  int addrBypass = 0;    /* Address of jump over the delete logic */
  int addrLoop = 0;      /* Top of the delete loop */
  int addrDelete = 0;    /* Jump directly to the delete logic */
  int addrEphOpen = 0;   /* Instruction to open the Ephemeral table */
 
#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  Trigger *pTrigger;           /* List of table triggers, if required */
#endif

  memset(&sContext, 0, sizeof(sContext));

  if( v==0 ){
    goto delete_from_cleanup;
  }
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, 1, iDb);

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

    if( HasRowid(pTab) ){
      /* For a rowid table, initialize the RowSet to an empty set */
      pPk = 0;
      nPk = 1;
      iRowSet = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
    }else{
      /* For a WITHOUT ROWID table, create an ephemeral table used to
      ** hold all primary keys for rows to be deleted. */
      pPk = sqlite3PrimaryKeyIndex(pTab);
      assert( pPk!=0 );
      nPk = pPk->nKeyCol;
      iPk = pParse->nMem+1;
      pParse->nMem += nPk;
      iEphCur = pParse->nTab++;

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

** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the 
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expressions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/

      pRoot->flags |= EP_Collate & pLeft->flags;
    }
    exprSetHeight(pRoot);
  }
}

/*
** Allocate an Expr node which joins as many as two subtrees.
**
** One or both of the subtrees can be NULL.  Return a pointer to the new
** Expr node.  Or, if an OOM error occurs, set pParse->db->mallocFailed,
** free the subtrees and return NULL.
*/
Expr *sqlite3PExpr(
  Parse *pParse,          /* Parsing context */

**
** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
** sure "nnn" is not too be to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
** as the previous instance of the same wildcard.  Or if this is the first
** instance of the wildcard, the next sequential variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;
  const char *z;

  if( pExpr==0 ) return;

** return value with EP_Reduced|EP_TokenOnly.
**
** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
** (unreduced) Expr objects as they or originally constructed by the parser.
** During expression analysis, extra information is computed and moved into
** later parts of teh Expr object and that extra information might get chopped
** off if the expression is reduced.  Note also that it does not work to
** make an EXPRDUP_REDUCE copy of a reduced expression.  It is only legal
** to reduce a pristine expression tree from the parser.  The implementation
** of dupedExprStructSize() contain multiple assert() statements that attempt
** to enforce this constraint.
*/
static int dupedExprStructSize(Expr *p, int flags){
  int nSize;
  assert( flags==EXPRDUP_REDUCE || flags==0 ); /* Only one flag value allowed */

}

/*
** This function is similar to sqlite3ExprDup(), except that if pzBuffer 
** is not NULL then *pzBuffer is assumed to point to a buffer large enough 
** to store the copy of expression p, the copies of p->u.zToken
** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
** if any. Before returning, *pzBuffer is set to the first byte past the
** portion of the buffer copied into by this function.
*/
static Expr *exprDup(sqlite3 *db, Expr *p, int flags, u8 **pzBuffer){
  Expr *pNew = 0;                      /* Value to return */
  if( p ){
    const int isReduced = (flags&EXPRDUP_REDUCE);
    u8 *zAlloc;

** An existing b-tree might be used if the RHS expression pX is a simple
** subquery such as:
**
**     SELECT <column> FROM <table>
**
** If the RHS of the IN operator is a list or a more complex subquery, then
** an ephemeral table might need to be generated from the RHS and then
** pX->iTable made to point to the ephemeral table instead of an
** existing table.
**
** The inFlags parameter must contain exactly one of the bits
** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP.  If inFlags contains
** IN_INDEX_MEMBERSHIP, then the generated table will be used for a
** fast membership test.  When the IN_INDEX_LOOP bit is set, the
** IN index will be used to loop over all values of the RHS of the

    }
  }

  /* If no preexisting index is available for the IN clause
  ** and IN_INDEX_NOOP is an allowed reply
  ** and the RHS of the IN operator is a list, not a subquery
  ** and the RHS is not contant or has two or fewer terms,
  ** then it is not worth creating an ephemeral table to evaluate
  ** the IN operator so return IN_INDEX_NOOP.
  */
  if( eType==0
   && (inFlags & IN_INDEX_NOOP_OK)
   && !ExprHasProperty(pX, EP_xIsSelect)
   && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
  ){

}

/*
** Generate code to move content from registers iFrom...iFrom+nReg-1
** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
*/
void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){


  assert( iFrom>=iTo+nReg || iFrom+nReg<=iTo );
  sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);


  sqlite3ExprCacheRemove(pParse, iFrom, nReg);



}

#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
/*
** Return true if any register in the range iFrom..iTo (inclusive)
** is used as part of the column cache.
**

      pDef = sqlite3FindFunction(db, zId, nId, nFarg, enc, 0);
      if( pDef==0 || pDef->xFunc==0 ){
        sqlite3ErrorMsg(pParse, "unknown function: %.*s()", nId, zId);
        break;
      }

      /* Attempt a direct implementation of the built-in COALESCE() and
      ** IFNULL() functions.  This avoids unnecessary evaluation of
      ** arguments past the first non-NULL argument.
      */
      if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){
        int endCoalesce = sqlite3VdbeMakeLabel(v);
        assert( nFarg>=2 );
        sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
        for(i=1; i<nFarg; i++){

    sqlite3ExprCodeAtInit(pParse, pExpr, target, 0);
  }else{
    sqlite3ExprCode(pParse, pExpr, target);
  }
}

/*
** Generate code that evaluates the given expression and puts the result
** in register target.
**
** Also make a copy of the expression results into another "cache" register
** and modify the expression so that the next time it is evaluated,
** the result is a copy of the cache register.
**
** This routine is used for expressions that are used multiple 

**    x BETWEEN y AND z
**
** The above is equivalent to 
**
**    x>=y AND x<=z
**
** Code it as such, taking care to do the common subexpression
** elimination of x.
*/
static void exprCodeBetween(
  Parse *pParse,    /* Parsing and code generating context */
  Expr *pExpr,      /* The BETWEEN expression */
  int dest,         /* Jump here if the jump is taken */
  int jumpIfTrue,   /* Take the jump if the BETWEEN is true */
  int jumpIfNull    /* Take the jump if the BETWEEN is NULL */

}

/*
** Deallocate a register, making available for reuse for some other
** purpose.
**
** If a register is currently being used by the column cache, then
** the deallocation is deferred until the column cache line that uses
** the register becomes stale.
*/
void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
  if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
    int i;
    struct yColCache *p;
    for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){

**
**   3) No parent key columns were provided explicitly as part of the
**      foreign key definition, and the parent table does not have a
**      PRIMARY KEY, or
**
**   4) No parent key columns were provided explicitly as part of the
**      foreign key definition, and the PRIMARY KEY of the parent table 
**      consists of a different number of columns to the child key in 
**      the child table.
**
** then non-zero is returned, and a "foreign key mismatch" error loaded
** into pParse. If an OOM error occurs, non-zero is returned and the
** pParse->db->mallocFailed flag is set.
*/
int sqlite3FkLocateIndex(

/*
** 2002 February 23
**
** 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 the C-language implementations for many of the SQL
** functions of SQLite.  (Some function, and in particular the date and
** time functions, are implemented separately.)
*/
#include "sqliteInt.h"
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

    while( *z && p1 ){
      SQLITE_SKIP_UTF8(z);
      p1--;
    }
    for(z2=z; *z2 && p2; p2--){
      SQLITE_SKIP_UTF8(z2);
    }
    sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT,
                          SQLITE_UTF8);
  }else{
    if( p1+p2>len ){
      p2 = len-p1;
      if( p2<0 ) p2 = 0;
    }
    sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT);
  }
}

/*
** Implementation of the round() function
*/
#ifndef SQLITE_OMIT_FLOATING_POINT

  assert( nByte>0 );
  testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH] );
  testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH]+1 );
  if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
    sqlite3_result_error_toobig(context);
    z = 0;
  }else{
    z = sqlite3Malloc(nByte);
    if( !z ){
      sqlite3_result_error_nomem(context);
    }
  }
  return z;
}

    }else{
      *zOut++ = 0xF0 + (u8)((c>>18) & 0x07);
      *zOut++ = 0x80 + (u8)((c>>12) & 0x3F);
      *zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
      *zOut++ = 0x80 + (u8)(c & 0x3F);
    }                                                    \
  }
  sqlite3_result_text64(context, (char*)z, zOut-z, sqlite3_free, SQLITE_UTF8);
}

/*
** The hex() function.  Interpret the argument as a blob.  Return
** a hexadecimal rendering as text.
*/
static void hexFunc(

  assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
  assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
  *pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
  return 1;
}

/*
** All of the FuncDef structures in the aBuiltinFunc[] array above
** to the global function hash table.  This occurs at start-time (as
** a consequence of calling sqlite3_initialize()).
**
** After this routine runs
*/
void sqlite3RegisterGlobalFunctions(void){
  /*

    FUNCTION(ltrim,              2, 1, 0, trimFunc         ),
    FUNCTION(rtrim,              1, 2, 0, trimFunc         ),
    FUNCTION(rtrim,              2, 2, 0, trimFunc         ),
    FUNCTION(trim,               1, 3, 0, trimFunc         ),
    FUNCTION(trim,               2, 3, 0, trimFunc         ),
    FUNCTION(min,               -1, 0, 1, minmaxFunc       ),
    FUNCTION(min,                0, 0, 1, 0                ),
    AGGREGATE2(min,              1, 0, 1, minmaxStep,      minMaxFinalize,
                                          SQLITE_FUNC_MINMAX ),
    FUNCTION(max,               -1, 1, 1, minmaxFunc       ),
    FUNCTION(max,                0, 1, 1, 0                ),
    AGGREGATE2(max,              1, 1, 1, minmaxStep,      minMaxFinalize,
                                          SQLITE_FUNC_MINMAX ),
    FUNCTION2(typeof,            1, 0, 0, typeofFunc,  SQLITE_FUNC_TYPEOF),
    FUNCTION2(length,            1, 0, 0, lengthFunc,  SQLITE_FUNC_LENGTH),
    FUNCTION(instr,              2, 0, 0, instrFunc        ),
    FUNCTION(substr,             2, 0, 0, substrFunc       ),
    FUNCTION(substr,             3, 0, 0, substrFunc       ),
    FUNCTION(printf,            -1, 0, 0, printfFunc       ),
    FUNCTION(unicode,            1, 0, 0, unicodeFunc      ),

    FUNCTION2(likely,            1, 0, 0, noopFunc,  SQLITE_FUNC_UNLIKELY),
    VFUNCTION(random,            0, 0, 0, randomFunc       ),
    VFUNCTION(randomblob,        1, 0, 0, randomBlob       ),
    FUNCTION(nullif,             2, 0, 1, nullifFunc       ),
    FUNCTION(sqlite_version,     0, 0, 0, versionFunc      ),
    FUNCTION(sqlite_source_id,   0, 0, 0, sourceidFunc     ),
    FUNCTION(sqlite_log,         2, 0, 0, errlogFunc       ),
#if SQLITE_USER_AUTHENTICATION
    FUNCTION(sqlite_crypt,       2, 0, 0, sqlite3CryptFunc ),
#endif
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
    FUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc  ),
    FUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc  ),
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
    FUNCTION(quote,              1, 0, 0, quoteFunc        ),
    VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
    VFUNCTION(changes,           0, 0, 0, changes          ),
    VFUNCTION(total_changes,     0, 0, 0, total_changes    ),
    FUNCTION(replace,            3, 0, 0, replaceFunc      ),
    FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),
  #ifdef SQLITE_SOUNDEX
    FUNCTION(soundex,            1, 0, 0, soundexFunc      ),
  #endif
  #ifndef SQLITE_OMIT_LOAD_EXTENSION
    FUNCTION(load_extension,     1, 0, 0, loadExt          ),
    FUNCTION(load_extension,     2, 0, 0, loadExt          ),
  #endif
    AGGREGATE(sum,               1, 0, 0, sumStep,         sumFinalize    ),
    AGGREGATE(total,             1, 0, 0, sumStep,         totalFinalize    ),
    AGGREGATE(avg,               1, 0, 0, sumStep,         avgFinalize    ),
    AGGREGATE2(count,            0, 0, 0, countStep,       countFinalize,
               SQLITE_FUNC_COUNT  ),
    AGGREGATE(count,             1, 0, 0, countStep,       countFinalize  ),
    AGGREGATE(group_concat,      1, 0, 0, groupConcatStep, groupConcatFinalize),
    AGGREGATE(group_concat,      2, 0, 0, groupConcatStep, groupConcatFinalize),
  
    LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
  #ifdef SQLITE_CASE_SENSITIVE_LIKE
    LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),

/*
** 2008 June 13
**
** 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 definitions of global variables and constants.
*/
#include "sqliteInt.h"

/* An array to map all upper-case characters into their corresponding
** lower-case character. 
**
** SQLite only considers US-ASCII (or EBCDIC) characters.  We do not

**         insert the select result into <table> from R..R+n
**         goto C
**      D: cleanup
**
** The 4th template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT.  In the third form,
** we have to use an intermediate table to store the results of
** the select.  The template is like this:
**
**         X <- A
**         goto B
**      A: setup for the SELECT
**         loop over the tables in the SELECT
**           load value into register R..R+n

  /* If this is an AUTOINCREMENT table, look up the sequence number in the
  ** sqlite_sequence table and store it in memory cell regAutoinc.
  */
  regAutoinc = autoIncBegin(pParse, iDb, pTab);

  /* Allocate registers for holding the rowid of the new row,
  ** the content of the new row, and the assembled row record.
  */
  regRowid = regIns = pParse->nMem+1;
  pParse->nMem += pTab->nCol + 1;
  if( IsVirtual(pTab) ){
    regRowid++;
    pParse->nMem++;
  }

  sqlite3ExprListDelete(db, pList);
  sqlite3SelectDelete(db, pSelect);
  sqlite3IdListDelete(db, pColumn);
  sqlite3DbFree(db, aRegIdx);
}

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

  Index *pIdx;         /* Pointer to one of the indices */
  Index *pPk = 0;      /* The PRIMARY KEY index */
  sqlite3 *db;         /* Database connection */
  int i;               /* loop counter */
  int ix;              /* Index loop counter */
  int nCol;            /* Number of columns */
  int onError;         /* Conflict resolution strategy */
  int j1;              /* Address of jump instruction */
  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
  int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
  int ipkTop = 0;      /* Top of the rowid change constraint check */
  int ipkBottom = 0;   /* Bottom of the rowid change constraint check */
  u8 isUpdate;         /* True if this is an UPDATE operation */
  u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
  int regRowid = -1;   /* Register holding ROWID value */

  int appendBias,     /* True if this is likely to be an append */
  int useSeekResult   /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
){
  Vdbe *v;            /* Prepared statements under construction */
  Index *pIdx;        /* An index being inserted or updated */
  u8 pik_flags;       /* flag values passed to the btree insert */
  int regData;        /* Content registers (after the rowid) */
  int regRec;         /* Register holding assembled record for the table */
  int i;              /* Loop counter */
  u8 bAffinityDone = 0; /* True if OP_Affinity has been run already */

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){

#ifdef SQLITE_TEST
/*
** The following global variable is incremented whenever the
** transfer optimization is used.  This is used for testing
** purposes only - to make sure the transfer optimization really
** is happening when it is supposed to.
*/
int sqlite3_xferopt_count;
#endif /* SQLITE_TEST */


#ifndef SQLITE_OMIT_XFER_OPT
/*

/*
** Attempt the transfer optimization on INSERTs of the form
**
**     INSERT INTO tab1 SELECT * FROM tab2;
**
** The xfer optimization transfers raw records from tab2 over to tab1.  
** Columns are not decoded and reassembled, which greatly improves
** performance.  Raw index records are transferred in the same way.
**
** The xfer optimization is only attempted if tab1 and tab2 are compatible.
** There are lots of rules for determining compatibility - see comments
** embedded in the code for details.
**
** This routine returns TRUE if the optimization is guaranteed to be used.

  }

exec_out:
  if( pStmt ) sqlite3VdbeFinalize((Vdbe *)pStmt);
  sqlite3DbFree(db, azCols);

  rc = sqlite3ApiExit(db, rc);
  if( rc!=SQLITE_OK && pzErrMsg ){
    int nErrMsg = 1 + sqlite3Strlen30(sqlite3_errmsg(db));
    *pzErrMsg = sqlite3Malloc(nErrMsg);
    if( *pzErrMsg ){
      memcpy(*pzErrMsg, sqlite3_errmsg(db), nErrMsg);
    }else{
      rc = SQLITE_NOMEM;
      sqlite3Error(db, SQLITE_NOMEM);

** Inputs:
** A pointer to the function used to allocate memory.
**
** Outputs:
** A pointer to a parser.  This pointer is used in subsequent calls
** to Parse and ParseFree.
*/
void *ParseAlloc(void *(*mallocProc)(u64)){
  yyParser *pParser;
  pParser = (yyParser*)(*mallocProc)( (u64)sizeof(yyParser) );
  if( pParser ){
    pParser->yyidx = -1;
#ifdef YYTRACKMAXSTACKDEPTH
    pParser->yyidxMax = 0;
#endif
#if YYSTACKDEPTH<=0
    pParser->yystack = NULL;

  sqlite3_stmt_busy,
  sqlite3_stmt_readonly,
  sqlite3_stricmp,
  sqlite3_uri_boolean,
  sqlite3_uri_int64,
  sqlite3_uri_parameter,
  sqlite3_vsnprintf,
  sqlite3_wal_checkpoint_v2,
  /* Version 3.8.7 and later */
  sqlite3_auto_extension,
  sqlite3_bind_blob64,
  sqlite3_bind_text64,
  sqlite3_cancel_auto_extension,
  sqlite3_load_extension,
  sqlite3_malloc64,
  sqlite3_msize,
  sqlite3_realloc64,
  sqlite3_reset_auto_extension,
  sqlite3_result_blob64,
  sqlite3_result_text64,
  sqlite3_strglob
};

/*
** Attempt to load an SQLite extension library contained in the file
** zFile.  The entry point is zProc.  zProc may be 0 in which case a
** default entry point name (sqlite3_extension_init) is used.  Use
** of the default name is recommended.

  }
  sqlite3HashClear(&db->aModule);
#endif

  sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
  sqlite3ValueFree(db->pErr);
  sqlite3CloseExtensions(db);
#if SQLITE_USER_AUTHENTICATION
  sqlite3_free(db->auth.zAuthUser);
  sqlite3_free(db->auth.zAuthPW);
#endif

  db->magic = SQLITE_MAGIC_ERROR;

  /* The temp-database schema is allocated differently from the other schema
  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
  ** So it needs to be freed here. Todo: Why not roll the temp schema into
  ** the same sqliteMalloc() as the one that allocates the database 

    }
    sqlite3Error(db, rc);
    goto opendb_out;
  }
  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);


  /* The default safety_level for the main database is 'full'; for the temp
  ** database it is 'NONE'. This matches the pager layer defaults.  
  */
  db->aDb[0].zName = "main";
  db->aDb[0].safety_level = 3;
  db->aDb[1].zName = "temp";
  db->aDb[1].safety_level = 1;

** by the next COMMIT or ROLLBACK.
*/
int sqlite3_get_autocommit(sqlite3 *db){
  return db->autoCommit;
}

/*
** The following routines are substitutes for constants SQLITE_CORRUPT,
** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
** constants.  They serve two purposes:
**
**   1.  Serve as a convenient place to set a breakpoint in a debugger
**       to detect when version error conditions occurs.
**
**   2.  Invoke sqlite3_log() to provide the source code location where
**       a low-level error is first detected.
*/

    ** Set the PENDING byte to the value in the argument, if X>0.
    ** Make no changes if X==0.  Return the value of the pending byte
    ** as it existing before this routine was called.
    **
    ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
    ** an incompatible database file format.  Changing the PENDING byte
    ** while any database connection is open results in undefined and
    ** deleterious behavior.
    */
    case SQLITE_TESTCTRL_PENDING_BYTE: {
      rc = PENDING_BYTE;
#ifndef SQLITE_OMIT_WSD
      {
        unsigned int newVal = va_arg(ap, unsigned int);
        if( newVal ) sqlite3PendingByte = newVal;

  return nFull;
}

/*
** Allocate memory.  This routine is like sqlite3_malloc() except that it
** assumes the memory subsystem has already been initialized.
*/
void *sqlite3Malloc(u64 n){
  void *p;

  if( n==0 || n>=0x7fffff00 ){

    /* A memory allocation of a number of bytes which is near the maximum
    ** signed integer value might cause an integer overflow inside of the
    ** xMalloc().  Hence we limit the maximum size to 0x7fffff00, giving
    ** 255 bytes of overhead.  SQLite itself will never use anything near
    ** this amount.  The only way to reach the limit is with sqlite3_malloc() */
    p = 0;
  }else if( sqlite3GlobalConfig.bMemstat ){
    sqlite3_mutex_enter(mem0.mutex);
    mallocWithAlarm(n, &p);
    sqlite3_mutex_leave(mem0.mutex);
  }else{
    p = sqlite3GlobalConfig.m.xMalloc((int)n);
  }
  assert( EIGHT_BYTE_ALIGNMENT(p) );  /* IMP: R-04675-44850 */
  return p;
}

/*
** This version of the memory allocation is for use by the application.
** First make sure the memory subsystem is initialized, then do the
** allocation.
*/
void *sqlite3_malloc(int n){
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  return n<=0 ? 0 : sqlite3Malloc(n);
}
void *sqlite3_malloc64(sqlite3_uint64 n){
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  return sqlite3Malloc(n);
}

/*
** Each thread may only have a single outstanding allocation from
** xScratchMalloc().  We verify this constraint in the single-threaded
** case by setting scratchAllocOut to 1 when an allocation

  }else{
    assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
    assert( sqlite3MemdebugHasType(p, MEMTYPE_LOOKASIDE|MEMTYPE_HEAP) );
    assert( db!=0 || sqlite3MemdebugNoType(p, MEMTYPE_LOOKASIDE) );
    return sqlite3GlobalConfig.m.xSize(p);
  }
}
sqlite3_uint64 sqlite3_msize(void *p){
  return (sqlite3_uint64)sqlite3GlobalConfig.m.xSize(p);
}

/*
** Free memory previously obtained from sqlite3Malloc().
*/
void sqlite3_free(void *p){
  if( p==0 ) return;  /* IMP: R-49053-54554 */
  assert( sqlite3MemdebugNoType(p, MEMTYPE_DB) );

  sqlite3MemdebugSetType(p, MEMTYPE_HEAP);
  sqlite3_free(p);
}

/*
** Change the size of an existing memory allocation
*/
void *sqlite3Realloc(void *pOld, u64 nBytes){
  int nOld, nNew, nDiff;
  void *pNew;
  if( pOld==0 ){
    return sqlite3Malloc(nBytes); /* IMP: R-28354-25769 */
  }
  if( nBytes==0 ){
    sqlite3_free(pOld); /* IMP: R-31593-10574 */
    return 0;
  }
  if( nBytes>=0x7fffff00 ){
    /* The 0x7ffff00 limit term is explained in comments on sqlite3Malloc() */
    return 0;
  }
  nOld = sqlite3MallocSize(pOld);
  /* IMPLEMENTATION-OF: R-46199-30249 SQLite guarantees that the second
  ** argument to xRealloc is always a value returned by a prior call to
  ** xRoundup. */
  nNew = sqlite3GlobalConfig.m.xRoundup((int)nBytes);
  if( nOld==nNew ){
    pNew = pOld;
  }else if( sqlite3GlobalConfig.bMemstat ){
    sqlite3_mutex_enter(mem0.mutex);
    sqlite3StatusSet(SQLITE_STATUS_MALLOC_SIZE, nBytes);
    nDiff = nNew - nOld;
    if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 

** The public interface to sqlite3Realloc.  Make sure that the memory
** subsystem is initialized prior to invoking sqliteRealloc.
*/
void *sqlite3_realloc(void *pOld, int n){
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  if( n<0 ) n = 0;
  return sqlite3Realloc(pOld, n);
}
void *sqlite3_realloc64(void *pOld, sqlite3_uint64 n){
#ifndef SQLITE_OMIT_AUTOINIT
  if( sqlite3_initialize() ) return 0;
#endif
  return sqlite3Realloc(pOld, n);
}


/*
** Allocate and zero memory.
*/ 
void *sqlite3MallocZero(u64 n){
  void *p = sqlite3Malloc(n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate and zero memory.  If the allocation fails, make
** the mallocFailed flag in the connection pointer.
*/
void *sqlite3DbMallocZero(sqlite3 *db, u64 n){
  void *p = sqlite3DbMallocRaw(db, n);
  if( p ){
    memset(p, 0, n);
  }
  return p;
}

**         int *a = (int*)sqlite3DbMallocRaw(db, 100);
**         int *b = (int*)sqlite3DbMallocRaw(db, 200);
**         if( b ) a[10] = 9;
**
** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
** that all prior mallocs (ex: "a") worked too.
*/
void *sqlite3DbMallocRaw(sqlite3 *db, u64 n){
  void *p;
  assert( db==0 || sqlite3_mutex_held(db->mutex) );
  assert( db==0 || db->pnBytesFreed==0 );
#ifndef SQLITE_OMIT_LOOKASIDE
  if( db ){
    LookasideSlot *pBuf;
    if( db->mallocFailed ){

  return p;
}

/*
** Resize the block of memory pointed to by p to n bytes. If the
** resize fails, set the mallocFailed flag in the connection object.
*/
void *sqlite3DbRealloc(sqlite3 *db, void *p, u64 n){
  void *pNew = 0;
  assert( db!=0 );
  assert( sqlite3_mutex_held(db->mutex) );
  if( db->mallocFailed==0 ){
    if( p==0 ){
      return sqlite3DbMallocRaw(db, n);
    }

  return pNew;
}

/*
** Attempt to reallocate p.  If the reallocation fails, then free p
** and set the mallocFailed flag in the database connection.
*/
void *sqlite3DbReallocOrFree(sqlite3 *db, void *p, u64 n){
  void *pNew;
  pNew = sqlite3DbRealloc(db, p, n);
  if( !pNew ){
    sqlite3DbFree(db, p);
  }
  return pNew;
}

  assert( (n&0x7fffffff)==n );
  zNew = sqlite3DbMallocRaw(db, (int)n);
  if( zNew ){
    memcpy(zNew, z, n);
  }
  return zNew;
}
char *sqlite3DbStrNDup(sqlite3 *db, const char *z, u64 n){
  char *zNew;
  if( z==0 ){
    return 0;
  }
  assert( (n&0x7fffffff)==n );
  zNew = sqlite3DbMallocRaw(db, n+1);
  if( zNew ){

/*
** Like realloc().  Resize an allocation previously obtained from
** sqlite3MemMalloc().
**
** For this low-level interface, we know that pPrior!=0.  Cases where
** pPrior==0 while have been intercepted by higher-level routine and
** redirected to xMalloc.  Similarly, we know that nByte>0 because
** cases where nByte<=0 will have been intercepted by higher-level
** routines and redirected to xFree.
*/
static void *sqlite3MemRealloc(void *pPrior, int nByte){
#ifdef SQLITE_MALLOCSIZE
  void *p = SQLITE_REALLOC(pPrior, nByte);
  if( p==0 ){

** in the build only if SQLITE_ENABLE_MEMSYS5 is defined.
**
** This memory allocator uses the following algorithm:
**
**   1.  All memory allocations sizes are rounded up to a power of 2.
**
**   2.  If two adjacent free blocks are the halves of a larger block,
**       then the two blocks are coalesced into the single larger block.
**
**   3.  New memory is allocated from the first available free block.
**
** This algorithm is described in: J. M. Robson. "Bounds for Some Functions
** Concerning Dynamic Storage Allocation". Journal of the Association for
** Computing Machinery, Volume 21, Number 8, July 1974, pages 491-499.
** 

typedef struct FileChunk FileChunk;

/* Space to hold the rollback journal is allocated in increments of
** this many bytes.
**
** The size chosen is a little less than a power of two.  That way,
** the FileChunk object will have a size that almost exactly fills
** a power-of-two allocation.  This minimizes wasted space in power-of-two
** memory allocators.
*/
#define JOURNAL_CHUNKSIZE ((int)(1024-sizeof(FileChunk*)))

/*
** The rollback journal is composed of a linked list of these structures.
*/

*/


/*
** Figure out what version of the code to use.  The choices are
**
**   SQLITE_MUTEX_OMIT         No mutex logic.  Not even stubs.  The
**                             mutexes implementation cannot be overridden
**                             at start-time.
**
**   SQLITE_MUTEX_NOOP         For single-threaded applications.  No
**                             mutual exclusion is provided.  But this
**                             implementation can be overridden at
**                             start-time.
**

**
** The following #defines specify the range of bytes used for locking.
** SHARED_SIZE is the number of bytes available in the pool from which
** a random byte is selected for a shared lock.  The pool of bytes for
** shared locks begins at SHARED_FIRST. 
**
** The same locking strategy and
** byte ranges are used for Unix.  This leaves open the possibility of having
** clients on win95, winNT, and unix all talking to the same shared file
** and all locking correctly.  To do so would require that samba (or whatever
** tool is being used for file sharing) implements locks correctly between
** windows and unix.  I'm guessing that isn't likely to happen, but by
** using the same locking range we are at least open to the possibility.
**
** Locking in windows is manditory.  For this reason, we cannot store

# if defined(__linux__) && defined(_GNU_SOURCE)
#  define HAVE_MREMAP 1
# else
#  define HAVE_MREMAP 0
# endif
#endif

/*
** Explicitly call the 64-bit version of lseek() on Android. Otherwise, lseek()
** is the 32-bit version, even if _FILE_OFFSET_BITS=64 is defined.
*/
#ifdef __ANDROID__
# define lseek lseek64
#endif

/*
** Different Unix systems declare open() in different ways.  Same use
** open(const char*,int,mode_t).  Others use open(const char*,int,...).
** The difference is important when using a pointer to the function.
**
** The safest way to deal with the problem is to always use this wrapper
** which always has the same well-defined interface.

}
#endif


#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
/*
** Helper function for printing out trace information from debugging
** binaries. This returns the string representation of the supplied
** integer lock-type.
*/
static const char *azFileLock(int eFileLock){
  switch( eFileLock ){
    case NO_LOCK: return "NONE";
    case SHARED_LOCK: return "SHARED";
    case RESERVED_LOCK: return "RESERVED";

}
#undef osFcntl
#define osFcntl lockTrace
#endif /* SQLITE_LOCK_TRACE */

/*
** Retry ftruncate() calls that fail due to EINTR
**
** All calls to ftruncate() within this file should be made through this wrapper.
** On the Android platform, bypassing the logic below could lead to a corrupt
** database.
*/
static int robust_ftruncate(int h, sqlite3_int64 sz){
  int rc;
#ifdef __ANDROID__
  /* On Android, ftruncate() always uses 32-bit offsets, even if 
  ** _FILE_OFFSET_BITS=64 is defined. This means it is unsafe to attempt to
  ** truncate a file to any size larger than 2GiB. Silently ignore any
  ** such attempts.  */
  if( sz>(sqlite3_int64)0x7FFFFFFF ){
    rc = SQLITE_OK;
  }else
#endif
  do{ rc = osFtruncate(h,sz); }while( rc<0 && errno==EINTR );
  return rc;
}

/*
** This routine translates a standard POSIX errno code into something
** useful to the clients of the sqlite3 functions.  Specifically, it is

/*
** Seek to the offset passed as the second argument, then read cnt 
** bytes into pBuf. Return the number of bytes actually read.
**
** NB:  If you define USE_PREAD or USE_PREAD64, then it might also
** be necessary to define _XOPEN_SOURCE to be 500.  This varies from
** one system to another.  Since SQLite does not define USE_PREAD
** in any form by default, we will not attempt to define _XOPEN_SOURCE.
** See tickets #2741 and #2681.
**
** To avoid stomping the errno value on a failed read the lastErrno value
** is set before returning.
*/
static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
  int got;

  ** actual file size after the operation may be larger than the requested
  ** size).
  */
  if( pFile->szChunk>0 ){
    nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
  }

  rc = robust_ftruncate(pFile->h, nByte);
  if( rc ){
    pFile->lastErrno = errno;
    return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
  }else{
#ifdef SQLITE_DEBUG
    /* If we are doing a normal write to a database file (as opposed to
    ** doing a hot-journal rollback or a write to some file other than a

  }
#endif

  return SQLITE_OK;
}

/*
** If *pArg is initially negative then this is a query.  Set *pArg to
** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
**
** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
*/
static void unixModeBit(unixFile *pFile, unsigned char mask, int *pArg){
  if( *pArg<0 ){
    *pArg = (pFile->ctrlFlags & mask)!=0;

}
#endif /* __QNXNTO__ */

/*
** Return the device characteristics for the file.
**
** This VFS is set up to return SQLITE_IOCAP_POWERSAFE_OVERWRITE by default.
** However, that choice is controversial since technically the underlying
** file system does not always provide powersafe overwrites.  (In other
** words, after a power-loss event, parts of the file that were never
** written might end up being altered.)  However, non-PSOW behavior is very,
** very rare.  And asserting PSOW makes a large reduction in the amount
** of required I/O for journaling, since a lot of padding is eliminated.
**  Hence, while POWERSAFE_OVERWRITE is on by default, there is a file-control
** available to turn it off and URI query parameter available to turn it off.

** the correct finder-function for that VFS.
**
** Most finder functions return a pointer to a fixed sqlite3_io_methods
** object.  The only interesting finder-function is autolockIoFinder, which
** looks at the filesystem type and tries to guess the best locking
** strategy from that.
**
** For finder-function F, two objects are created:
**
**    (1) The real finder-function named "FImpt()".
**
**    (2) A constant pointer to this function named just "F".
**
**
** A pointer to the F pointer is used as the pAppData value for VFS

}
static const sqlite3_io_methods 
  *(*const autolockIoFinder)(const char*,unixFile*) = autolockIoFinderImpl;

#endif /* OS_VXWORKS && SQLITE_ENABLE_LOCKING_STYLE */

/*
** An abstract type for a pointer to an IO method finder function:
*/
typedef const sqlite3_io_methods *(*finder_type)(const char*,unixFile*);


/****************************************************************************
**************************** sqlite3_vfs methods ****************************
**

  /* A stat() call may fail for various reasons. If this happens, it is
  ** almost certain that an open() call on the same path will also fail.
  ** For this reason, if an error occurs in the stat() call here, it is
  ** ignored and -1 is returned. The caller will try to open a new file
  ** descriptor on the same path, fail, and return an error to SQLite.
  **
  ** Even if a subsequent open() call does succeed, the consequences of
  ** not searching for a reusable file descriptor are not dire.  */
  if( 0==osStat(zPath, &sStat) ){
    unixInodeInfo *pInode;

    unixEnterMutex();
    pInode = inodeList;
    while( pInode && (pInode->fileId.dev!=sStat.st_dev
                     || pInode->fileId.ino!=sStat.st_ino) ){

/*
** This function is called by unixOpen() to determine the unix permissions
** to create new files with. If no error occurs, then SQLITE_OK is returned
** and a value suitable for passing as the third argument to open(2) is
** written to *pMode. If an IO error occurs, an SQLite error code is 
** returned and the value of *pMode is not modified.
**
** In most cases, this routine sets *pMode to 0, which will become
** an indication to robust_open() to create the file using
** SQLITE_DEFAULT_FILE_PERMISSIONS adjusted by the umask.
** But if the file being opened is a WAL or regular journal file, then 
** this function queries the file-system for the permissions on the 
** corresponding database file and sets *pMode to this value. Whenever 
** possible, WAL and journal files are created using the same permissions 
** as the associated database file.

**
** The conch file - to use a proxy file, sqlite must first "hold the conch"
** by taking an sqlite-style shared lock on the conch file, reading the
** contents and comparing the host's unique host ID (see below) and lock
** proxy path against the values stored in the conch.  The conch file is
** stored in the same directory as the database file and the file name
** is patterned after the database file name as ".<databasename>-conch".
** If the conch file does not exist, or its contents do not match the
** host ID and/or proxy path, then the lock is escalated to an exclusive
** lock and the conch file contents is updated with the host ID and proxy
** path and the lock is downgraded to a shared lock again.  If the conch
** is held by another process (with a shared lock), the exclusive lock
** will fail and SQLITE_BUSY is returned.
**
** The proxy file - a single-byte file used for all advisory file locks

**       lock proxy files, only used when LOCKPROXYDIR is not set.
**    
**    
** As mentioned above, when compiled with SQLITE_PREFER_PROXY_LOCKING,
** setting the environment variable SQLITE_FORCE_PROXY_LOCKING to 1 will
** force proxy locking to be used for every database file opened, and 0
** will force automatic proxy locking to be disabled for all database
** files (explicitly calling the SQLITE_SET_LOCKPROXYFILE pragma or
** sqlite_file_control API is not affected by SQLITE_FORCE_PROXY_LOCKING).
*/

/*
** Proxy locking is only available on MacOSX 
*/
#if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE

  assert( sleepObj!=NULL );
  osWaitForSingleObjectEx(sleepObj, milliseconds, FALSE);
#else
  osSleep(milliseconds);
#endif
}

#if SQLITE_MAX_WORKER_THREADS>0 && !SQLITE_OS_WINRT && SQLITE_THREADSAFE>0
DWORD sqlite3Win32Wait(HANDLE hObject){
  DWORD rc;
  while( (rc = osWaitForSingleObjectEx(hObject, INFINITE,
                                       TRUE))==WAIT_IO_COMPLETION ){}
  return rc;
}
#endif

/*
** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
** or WinCE.  Return false (zero) for Win95, Win98, or WinME.
**
** Here is an interesting observation:  Win95, Win98, and WinME lack
** the LockFileEx() API.  But we can still statically link against that

  pFile->locktype = (u8)locktype;
  OSTRACE(("UNLOCK file=%p, lock=%d, rc=%s\n",
           pFile->h, pFile->locktype, sqlite3ErrName(rc)));
  return rc;
}

/*
** If *pArg is initially negative then this is a query.  Set *pArg to
** 1 or 0 depending on whether or not bit mask of pFile->ctrlFlags is set.
**
** If *pArg is 0 or 1, then clear or set the mask bit of pFile->ctrlFlags.
*/
static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
  if( *pArg<0 ){
    *pArg = (pFile->ctrlFlags & mask)!=0;

           osGetCurrentProcessId(), pFd, iOff, p));

  if( p ){
    pFd->nFetchOut--;
  }else{
    /* FIXME:  If Windows truly always prevents truncating or deleting a
    ** file while a mapping is held, then the following winUnmapfile() call
    ** is unnecessary can be omitted - potentially improving
    ** performance.  */
    winUnmapfile(pFd);
  }

  assert( pFd->nFetchOut>=0 );
#endif

** 
** (6) If a master journal file is used, then all writes to the database file
**     are synced prior to the master journal being deleted.
** 
** Definition: Two databases (or the same database at two points it time)
** are said to be "logically equivalent" if they give the same answer to
** all queries.  Note in particular the content of freelist leaf
** pages can be changed arbitrarily without affecting the logical equivalence
** of the database.
** 
** (7) At any time, if any subset, including the empty set and the total set,
**     of the unsynced changes to a rollback journal are removed and the 
**     journal is rolled back, the resulting database file will be logically
**     equivalent to the database file at the beginning of the transaction.
** 
** (8) When a transaction is rolled back, the xTruncate method of the VFS
**     is called to restore the database file to the same size it was at
**     the beginning of the transaction.  (In some VFSes, the xTruncate
**     method is a no-op, but that does not change the fact the SQLite will
**     invoke it.)

**
** This is usually safe. If an xUnlock fails or appears to fail, there may 
** be a few redundant xLock() calls or a lock may be held for longer than
** required, but nothing really goes wrong.
**
** The exception is when the database file is unlocked as the pager moves
** from ERROR to OPEN state. At this point there may be a hot-journal file 
** in the file-system that needs to be rolled back (as part of an OPEN->SHARED
** transition, by the same pager or any other). If the call to xUnlock()
** fails at this point and the pager is left holding an EXCLUSIVE lock, this
** can confuse the call to xCheckReservedLock() call made later as part
** of hot-journal detection.
**
** xCheckReservedLock() is defined as returning true "if there is a RESERVED 
** lock held by this process or any others". So xCheckReservedLock may 

** Bits of the Pager.doNotSpill flag.  See further description below.
*/
#define SPILLFLAG_OFF         0x01      /* Never spill cache.  Set via pragma */
#define SPILLFLAG_ROLLBACK    0x02      /* Current rolling back, so do not spill */
#define SPILLFLAG_NOSYNC      0x04      /* Spill is ok, but do not sync */

/*
** An open page cache is an instance of struct Pager. A description of
** some of the more important member variables follows:
**
** eState
**
**   The current 'state' of the pager object. See the comment and state
**   diagram above for a description of the pager state.
**

  u8 noLock;                  /* Do not lock (except in WAL mode) */
  u8 readOnly;                /* True for a read-only database */
  u8 memDb;                   /* True to inhibit all file I/O */
  u8 otaMode;                 /* True if in ota_mode */

  /**************************************************************************
  ** The following block contains those class members that change during
  ** routine operation.  Class members not in this block are either fixed
  ** when the pager is first created or else only change when there is a
  ** significant mode change (such as changing the page_size, locking_mode,
  ** or the journal_mode).  From another view, these class members describe
  ** the "state" of the pager, while other class members describe the
  ** "configuration" of the pager.
  */
  u8 eState;                  /* Pager state (OPEN, READER, WRITER_LOCKED..) */

  ** sqlite3_malloc() and pointed to by zMasterJournal.   Also obtain
  ** sufficient space (in zMasterPtr) to hold the names of master
  ** journal files extracted from regular rollback-journals.
  */
  rc = sqlite3OsFileSize(pMaster, &nMasterJournal);
  if( rc!=SQLITE_OK ) goto delmaster_out;
  nMasterPtr = pVfs->mxPathname+1;
  zMasterJournal = sqlite3Malloc(nMasterJournal + nMasterPtr + 1);
  if( !zMasterJournal ){
    rc = SQLITE_NOMEM;
    goto delmaster_out;
  }
  zMasterPtr = &zMasterJournal[nMasterJournal+1];
  rc = sqlite3OsRead(pMaster, zMasterJournal, (int)nMasterJournal, 0);
  if( rc!=SQLITE_OK ) goto delmaster_out;

**
** If the main database file is not open, or the pager is not in either
** DBMOD or OPEN state, this function is a no-op. Otherwise, the size 
** of the file is changed to nPage pages (nPage*pPager->pageSize bytes). 
** If the file on disk is currently larger than nPage pages, then use the VFS
** xTruncate() method to truncate it.
**
** Or, it might be the case that the file on disk is smaller than 
** nPage pages. Some operating system implementations can get confused if 
** you try to truncate a file to some size that is larger than it 
** currently is, so detect this case and write a single zero byte to 
** the end of the new file instead.
**
** If successful, return SQLITE_OK. If an IO error occurs while modifying
** the database file, return the error code to the caller.

  }
  return iRet;
}

/*
** Set the value of the Pager.sectorSize variable for the given
** pager based on the value returned by the xSectorSize method
** of the open database file. The sector size will be used 
** to determine the size and alignment of journal header and 
** master journal pointers within created journal files.
**
** For temporary files the effective sector size is always 512 bytes.
**
** Otherwise, for non-temporary files, the effective sector size is
** the value returned by the xSectorSize() method rounded up to 32 if

    if( rc==SQLITE_OK ){
      pNew = (char *)sqlite3PageMalloc(pageSize);
      if( !pNew ) rc = SQLITE_NOMEM;
    }

    if( rc==SQLITE_OK ){
      pager_reset(pPager);


      sqlite3PageFree(pPager->pTmpSpace);
      pPager->pTmpSpace = pNew;
      rc = sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);
    }
    if( rc==SQLITE_OK ){
      pPager->dbSize = (Pgno)((nByte+pageSize-1)/pageSize);
      pPager->pageSize = pageSize;
    }
  }

  *pPageSize = pPager->pageSize;
  if( rc==SQLITE_OK ){
    if( nReserve<0 ) nReserve = pPager->nReserve;
    assert( nReserve>=0 && nReserve<1000 );
    pPager->nReserve = (i16)nReserve;

** the lock. If the lock is obtained successfully, set the Pager.state 
** variable to locktype before returning.
*/
static int pager_wait_on_lock(Pager *pPager, int locktype){
  int rc;                              /* Return code */

  /* Check that this is either a no-op (because the requested lock is 
  ** already held), or one of the transitions that the busy-handler
  ** may be invoked during, according to the comment above
  ** sqlite3PagerSetBusyhandler().
  */
  assert( (pPager->eLock>=locktype)
       || (pPager->eLock==NO_LOCK && locktype==SHARED_LOCK)
       || (pPager->eLock==RESERVED_LOCK && locktype==EXCLUSIVE_LOCK)
  );

  ** pages belonging to the same sector.
  **
  ** The doNotSpill ROLLBACK and OFF bits inhibits all cache spilling
  ** regardless of whether or not a sync is required.  This is set during
  ** a rollback or by user request, respectively.
  **
  ** Spilling is also prohibited when in an error state since that could
  ** lead to database corruption.   In the current implementation it 
  ** is impossible for sqlite3PcacheFetch() to be called with createFlag==3
  ** while in the error state, hence it is impossible for this routine to
  ** be called in the error state.  Nevertheless, we include a NEVER()
  ** test for the error state as a safeguard against future changes.
  */
  if( NEVER(pPager->errCode) ) return SQLITE_OK;
  testcase( pPager->doNotSpill & SPILLFLAG_ROLLBACK );

            }
            if( !jrnlOpen ){
              sqlite3OsClose(pPager->jfd);
            }
            *pExists = (first!=0);
          }else if( rc==SQLITE_CANTOPEN ){
            /* If we cannot open the rollback journal file in order to see if
            ** it has a zero header, that might be due to an I/O error, or
            ** it might be due to the race condition described above and in
            ** ticket #3883.  Either way, assume that the journal is hot.
            ** This might be a false positive.  But if it is, then the
            ** automatic journal playback and recovery mechanism will deal
            ** with it under an EXCLUSIVE lock where we do not need to
            ** worry so much with race conditions.
            */

# define expensive_assert(X)  assert(X)
#else
# define expensive_assert(X)
#endif

/********************************** Linked List Management ********************/


















/* Allowed values for second argument to pcacheManageDirtyList() */
#define PCACHE_DIRTYLIST_REMOVE   1    /* Remove pPage from dirty list */
#define PCACHE_DIRTYLIST_ADD      2    /* Add pPage to the dirty list */
#define PCACHE_DIRTYLIST_FRONT    3    /* Move pPage to the front of the list */

/*
** Manage pPage's participation on the dirty list.  Bits of the addRemove

      if( p->pDirty==0 && p->bPurgeable ){
        assert( p->eCreate==1 );
        p->eCreate = 2;
      }
    }
    pPage->pDirtyNext = 0;
    pPage->pDirtyPrev = 0;

  }
  if( addRemove & PCACHE_DIRTYLIST_ADD ){
    assert( pPage->pDirtyNext==0 && pPage->pDirtyPrev==0 && p->pDirty!=pPage );
  
    pPage->pDirtyNext = p->pDirty;
    if( pPage->pDirtyNext ){
      assert( pPage->pDirtyNext->pDirtyPrev==0 );
      pPage->pDirtyNext->pDirtyPrev = pPage;
    }else{
      p->pDirtyTail = pPage;
      if( p->bPurgeable ){
        assert( p->eCreate==2 );
        p->eCreate = 1;
      }



    }
    p->pDirty = pPage;
    if( !p->pSynced && 0==(pPage->flags&PGHDR_NEED_SYNC) ){
      p->pSynced = pPage;
    }

  }
}

/*
** Wrapper around the pluggable caches xUnpin method. If the cache is
** being used for an in-memory database, this function is a no-op.
*/

  /* Find a dirty page to write-out and recycle. First try to find a 
  ** page that does not require a journal-sync (one with PGHDR_NEED_SYNC
  ** cleared), but if that is not possible settle for any other 
  ** unreferenced dirty page.
  */

  for(pPg=pCache->pSynced; 
      pPg && (pPg->nRef || (pPg->flags&PGHDR_NEED_SYNC)); 
      pPg=pPg->pDirtyPrev
  );
  pCache->pSynced = pPg;
  if( !pPg ){
    for(pPg=pCache->pDirtyTail; pPg && pPg->nRef; pPg=pPg->pDirtyPrev);

    pCache->pPage1 = pPgHdr;
  }
  return pPgHdr;
}

/*
** Decrement the reference count on a page. If the page is clean and the
** reference count drops to 0, then it is made eligible for recycling.
*/
void SQLITE_NOINLINE sqlite3PcacheRelease(PgHdr *p){
  assert( p->nRef>0 );
  p->nRef--;
  if( p->nRef==0 ){
    p->pCache->nRef--;
    if( (p->flags&PGHDR_DIRTY)==0 ){
      pcacheUnpin(p);
    }else if( p->pDirtyPrev!=0 ){
      /* Move the page to the head of the dirty list. */
      pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
    }
  }
}

/*

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file implements the default page cache implementation (the
** sqlite3_pcache interface). It also contains part of the implementation
** of the SQLITE_CONFIG_PAGECACHE and sqlite3_release_memory() features.
** If the default page cache implementation is overridden, then neither of
** these two features are available.
*/

#include "sqliteInt.h"

typedef struct PCache1 PCache1;
typedef struct PgHdr1 PgHdr1;
typedef struct PgFreeslot PgFreeslot;
typedef struct PGroup PGroup;

/* Each page cache (or PCache) belongs to a PGroup.  A PGroup is a set 
** of one or more PCaches that are able to recycle each other's unpinned
** pages when they are under memory pressure.  A PGroup is an instance of
** the following object.
**
** This page cache implementation works in one of two modes:
**
**   (1)  Every PCache is the sole member of its own PGroup.  There is
**        one PGroup per PCache.

    }else{
      int mask = aPragmaNames[mid].iArg;    /* Mask of bits to set or clear. */
      if( db->autoCommit==0 ){
        /* Foreign key support may not be enabled or disabled while not
        ** in auto-commit mode.  */
        mask &= ~(SQLITE_ForeignKeys);
      }
#if SQLITE_USER_AUTHENTICATION
      if( db->auth.authLevel==UAUTH_User ){
        /* Do not allow non-admin users to modify the schema arbitrarily */
        mask &= ~(SQLITE_WriteSchema);
      }
#endif

      if( sqlite3GetBoolean(zRight, 0) ){
        db->flags |= mask;
      }else{
        db->flags &= ~mask;
        if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
      }

  {
    char *zSql;
    zSql = sqlite3MPrintf(db, 
        "SELECT name, rootpage, sql FROM '%q'.%s ORDER BY rowid",
        db->aDb[iDb].zName, zMasterName);
#ifndef SQLITE_OMIT_AUTHORIZATION
    {
      sqlite3_xauth xAuth;
      xAuth = db->xAuth;
      db->xAuth = 0;
#endif
      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
#ifndef SQLITE_OMIT_AUTHORIZATION
      db->xAuth = xAuth;
    }

** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
  int i, rc;
  int commit_internal = !(db->flags&SQLITE_InternChanges);
  
  assert( sqlite3_mutex_held(db->mutex) );
  assert( db->init.busy==0 );
  rc = SQLITE_OK;
  db->init.busy = 1;
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
    rc = sqlite3InitOne(db, i, pzErrMsg);
    if( rc ){
      sqlite3ResetOneSchema(db, i);
    }
  }

  /* Once all the other databases have been initialized, load the schema
  ** for the TEMP database. This is loaded last, as the TEMP database
  ** schema may contain references to objects in other databases.
  */
#ifndef SQLITE_OMIT_TEMPDB
  assert( db->nDb>1 );
  if( rc==SQLITE_OK && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
    rc = sqlite3InitOne(db, 1, pzErrMsg);
    if( rc ){
      sqlite3ResetOneSchema(db, 1);
    }
  }
#endif

  z = sqlite3VMPrintf(db, zFormat, ap);
  va_end(ap);
  return z;
}

/*
** Like sqlite3MPrintf(), but call sqlite3DbFree() on zStr after formatting
** the string and before returning.  This routine is intended to be used
** to modify an existing string.  For example:
**
**       x = sqlite3MPrintf(db, x, "prefix %s suffix", x);
**
*/
char *sqlite3MAppendf(sqlite3 *db, char *zStr, const char *zFormat, ...){
  va_list ap;

            ** likelihood(X,0.9375).
            ** EVIDENCE-OF: R-53436-40973 The likely(X) function is equivalent to
            ** likelihood(X,0.9375). */
            /* TUNING: unlikely() probability is 0.0625.  likely() is 0.9375 */
            pExpr->iTable = pDef->zName[0]=='u' ? 62 : 938;
          }             
        }

#ifndef SQLITE_OMIT_AUTHORIZATION

        auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
        if( auth!=SQLITE_OK ){
          if( auth==SQLITE_DENY ){
            sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
                                    pDef->zName);
            pNC->nErr++;
          }
          pExpr->op = TK_NULL;
          return WRC_Prune;
        }
#endif
        if( pDef->funcFlags & SQLITE_FUNC_CONSTANT ) ExprSetProperty(pExpr,EP_Constant);
      }

      if( is_agg && (pNC->ncFlags & NC_AllowAgg)==0 ){
        sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
        pNC->nErr++;
        is_agg = 0;
      }else if( no_such_func && pParse->db->init.busy==0 ){
        sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
        pNC->nErr++;

        NameContext *pNC2 = pNC;
        pExpr->op = TK_AGG_FUNCTION;
        pExpr->op2 = 0;
        while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
          pExpr->op2++;
          pNC2 = pNC2->pNext;
        }
        assert( pDef!=0 );
        if( pNC2 ){
          assert( SQLITE_FUNC_MINMAX==NC_MinMaxAgg );
          testcase( (pDef->funcFlags & SQLITE_FUNC_MINMAX)!=0 );
          pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);

        }
        pNC->ncFlags |= NC_AllowAgg;
      }
      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function 
      */
      return WRC_Prune;
    }

      }
    }
  }
  return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType);
}

/*
** Resolve names in the SELECT statement p and all of its descendants.
*/
static int resolveSelectStep(Walker *pWalker, Select *p){
  NameContext *pOuterNC;  /* Context that contains this SELECT */
  NameContext sNC;        /* Name context of this SELECT */
  int isCompound;         /* True if p is a compound select */
  int nCompound;          /* Number of compound terms processed so far */
  Parse *pParse;          /* Parsing context */

  
    /* If there are no aggregate functions in the result-set, and no GROUP BY 
    ** expression, do not allow aggregates in any of the other expressions.
    */
    assert( (p->selFlags & SF_Aggregate)==0 );
    pGroupBy = p->pGroupBy;
    if( pGroupBy || (sNC.ncFlags & NC_HasAgg)!=0 ){
      assert( NC_MinMaxAgg==SF_MinMaxAgg );
      p->selFlags |= SF_Aggregate | (sNC.ncFlags&NC_MinMaxAgg);
    }else{
      sNC.ncFlags &= ~NC_AllowAgg;
    }
  
    /* If a HAVING clause is present, then there must be a GROUP BY clause.
    */
    if( p->pHaving && !pGroupBy ){

** An error message is left in pParse if anything is amiss.  The number
** if errors is returned.
*/
int sqlite3ResolveExprNames( 
  NameContext *pNC,       /* Namespace to resolve expressions in. */
  Expr *pExpr             /* The expression to be analyzed. */
){
  u16 savedHasAgg;
  Walker w;

  if( pExpr==0 ) return 0;
#if SQLITE_MAX_EXPR_DEPTH>0
  {
    Parse *pParse = pNC->pParse;
    if( sqlite3ExprCheckHeight(pParse, pExpr->nHeight+pNC->pParse->nHeight) ){
      return 1;
    }
    pParse->nHeight += pExpr->nHeight;
  }
#endif
  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
  memset(&w, 0, sizeof(w));
  w.xExprCallback = resolveExprStep;
  w.xSelectCallback = resolveSelectStep;
  w.pParse = pNC->pParse;
  w.u.pNC = pNC;
  sqlite3WalkExpr(&w, pExpr);
#if SQLITE_MAX_EXPR_DEPTH>0
  pNC->pParse->nHeight -= pExpr->nHeight;
#endif
  if( pNC->nErr>0 || w.pParse->nErr>0 ){
    ExprSetProperty(pExpr, EP_Error);
  }
  if( pNC->ncFlags & NC_HasAgg ){
    ExprSetProperty(pExpr, EP_Agg);


  }
  pNC->ncFlags |= savedHasAgg;
  return ExprHasProperty(pExpr, EP_Error);
}


/*
** Resolve all names in all expressions of a SELECT and in all
** decendents of the SELECT, including compounds off of p->pPrior,

** value added by the INSERT will not be visible to the second TEST.
** The initial batch number is zero, so if the very first TEST contains
** a non-zero batch number, it will see all prior INSERTs.
**
** No INSERTs may occurs after a SMALLEST.  An assertion will fail if
** that is attempted.
**
** The cost of an INSERT is roughly constant.  (Sometimes new memory
** has to be allocated on an INSERT.)  The cost of a TEST with a new
** batch number is O(NlogN) where N is the number of elements in the RowSet.
** The cost of a TEST using the same batch number is O(logN).  The cost
** of the first SMALLEST is O(NlogN).  Second and subsequent SMALLEST
** primitives are constant time.  The cost of DESTROY is O(N).
**
** There is an added cost of O(N) when switching between TEST and

  }
}

/*
** Check to see if element iRowid was inserted into the rowset as
** part of any insert batch prior to iBatch.  Return 1 or 0.
**
** If this is the first test of a new batch and if there exist entries
** on pRowSet->pEntry, then sort those entries into the forest at
** pRowSet->pForest so that they can be tested.
*/
int sqlite3RowSetTest(RowSet *pRowSet, int iBatch, sqlite3_int64 iRowid){
  struct RowSetEntry *p, *pTree;

  /* This routine is never called after sqlite3RowSetNext() */
  assert( pRowSet!=0 && (pRowSet->rsFlags & ROWSET_NEXT)==0 );

    pParse->nMem += nBase;
  }
  sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, SQLITE_ECEL_DUP);
  if( bSeq ){
    sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
  }
  if( nPrefixReg==0 ){
    sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
  }

  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regRecord);
  if( nOBSat>0 ){
    int regPrevKey;   /* The first nOBSat columns of the previous row */
    int addrFirst;    /* Address of the OP_IfNot opcode */
    int addrJmp;      /* Address of the OP_Jump opcode */

    addrJmp = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
    pSort->labelBkOut = sqlite3VdbeMakeLabel(v);
    pSort->regReturn = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
    sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
    sqlite3VdbeJumpHere(v, addrFirst);
    sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
    sqlite3VdbeJumpHere(v, addrJmp);
  }
  if( pSort->sortFlags & SORTFLAG_UseSorter ){
    op = OP_SorterInsert;
  }else{
    op = OP_IdxInsert;
  }

**
** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
** KeyInfo structure is appropriate for initializing a virtual index to
** implement that clause.  If the ExprList is the result set of a SELECT
** then the KeyInfo structure is appropriate for initializing a virtual
** index to implement a DISTINCT test.
**
** Space to hold the KeyInfo structure is obtained from malloc.  The calling
** function is responsible for seeing that this structure is eventually
** freed.
*/
static KeyInfo *keyInfoFromExprList(
  Parse *pParse,       /* Parsing context */
  ExprList *pList,     /* Form the KeyInfo object from this ExprList */
  int iStart,          /* Begin with this column of pList */

      sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);
    }
  }
  generateColumnTypes(pParse, pTabList, pEList);
}

/*
** Given an expression list (which is really the list of expressions
** that form the result set of a SELECT statement) compute appropriate
** column names for a table that would hold the expression list.
**
** All column names will be unique.
**
** Only the column names are computed.  Column.zType, Column.zColl,
** and other fields of Column are zeroed.

    }
    if( db->mallocFailed ){
      sqlite3DbFree(db, zName);
      break;
    }

    /* Make sure the column name is unique.  If the name is not unique,
    ** append an integer to the name so that it becomes unique.
    */
    nName = sqlite3Strlen30(zName);
    for(j=cnt=0; j<i; j++){
      if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
        char *zNewName;
        int k;
        for(k=nName-1; k>1 && sqlite3Isdigit(zName[k]); k--){}

** optimized.
**
** This routine attempts to rewrite queries such as the above into
** a single flat select, like this:
**
**     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
**
** The code generated for this simplification gives the same result
** but only has to scan the data once.  And because indices might 
** exist on the table t1, a complete scan of the data might be
** avoided.
**
** Flattening is only attempted if all of the following are true:
**
**   (1)  The subquery and the outer query do not both use aggregates.

**        single NULL.
**
**   (8)  The subquery does not use LIMIT or the outer query is not a join.
**
**   (9)  The subquery does not use LIMIT or the outer query does not use
**        aggregates.
**
**  (**)  Restriction (10) was removed from the code on 2005-02-05 but we
**        accidently carried the comment forward until 2014-09-15.  Original
**        text: "The subquery does not use aggregates or the outer query does not
**        use LIMIT."
**
**  (11)  The subquery and the outer query do not both have ORDER BY clauses.
**
**  (**)  Not implemented.  Subsumed into restriction (3).  Was previously
**        a separate restriction deriving from ticket #350.
**
**  (13)  The subquery and outer query do not both use LIMIT.

**  (22)  The subquery is not a recursive CTE.
**
**  (23)  The parent is not a recursive CTE, or the sub-query is not a
**        compound query. This restriction is because transforming the
**        parent to a compound query confuses the code that handles
**        recursive queries in multiSelect().
**
**  (24)  The subquery is not an aggregate that uses the built-in min() or 
**        or max() functions.  (Without this restriction, a query like:
**        "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
**        return the value X for which Y was maximal.)
**
**
** In this routine, the "p" parameter is a pointer to the outer query.
** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
**
** If flattening is not attempted, this routine is a no-op and returns 0.
** If flattening is attempted this routine returns 1.

  pSub = pSubitem->pSelect;
  assert( pSub!=0 );
  if( isAgg && subqueryIsAgg ) return 0;                 /* Restriction (1)  */
  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;          /* Restriction (2)  */
  pSubSrc = pSub->pSrc;
  assert( pSubSrc );
  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
  ** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
  ** became arbitrary expressions, we were forced to add restrictions (13)
  ** and (14). */
  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
  if( pSub->pOffset ) return 0;                          /* Restriction (14) */
  if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
    return 0;                                            /* Restriction (15) */

     return 0;                                           /* Restriction (11) */
  }
  if( isAgg && pSub->pOrderBy ) return 0;                /* Restriction (16) */
  if( pSub->pLimit && p->pWhere ) return 0;              /* Restriction (19) */
  if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
     return 0;         /* Restriction (21) */
  }
  testcase( pSub->selFlags & SF_Recursive );
  testcase( pSub->selFlags & SF_MinMaxAgg );
  if( pSub->selFlags & (SF_Recursive|SF_MinMaxAgg) ){
    return 0; /* Restrictions (22) and (24) */
  }
  if( (p->selFlags & SF_Recursive) && pSub->pPrior ){
    return 0; /* Restriction (23) */
  }

  /* OBSOLETE COMMENT 1:
  ** Restriction 3:  If the subquery is a join, make sure the subquery is 
  ** not used as the right operand of an outer join.  Examples of why this
  ** is not allowed:
  **
  **         t1 LEFT OUTER JOIN (t2 JOIN t3)

  assert( *ppMinMax==0 || (*ppMinMax)->nExpr==1 );
  return eRet;
}

/*
** The select statement passed as the first argument is an aggregate query.
** The second argument is the associated aggregate-info object. This 
** function tests if the SELECT is of the form:
**
**   SELECT count(*) FROM <tbl>
**
** where table is a database table, not a sub-select or view. If the query
** does match this pattern, then a pointer to the Table object representing
** <tbl> is returned. Otherwise, 0 is returned.

**         element of the FROM clause.
**
**    (2)  Fill in the pTabList->a[].pTab fields in the SrcList that 
**         defines FROM clause.  When views appear in the FROM clause,
**         fill pTabList->a[].pSelect with a copy of the SELECT statement
**         that implements the view.  A copy is made of the view's SELECT
**         statement so that we can freely modify or delete that statement
**         without worrying about messing up the persistent representation
**         of the view.
**
**    (3)  Add terms to the WHERE clause to accommodate the NATURAL keyword
**         on joins and the ON and USING clause of joins.
**
**    (4)  Scan the list of columns in the result set (pEList) looking
**         for instances of the "*" operator or the TABLE.* operator.
**         If found, expand each "*" to be every column in every table
**         and TABLE.* to be every column in TABLE.
**

#endif

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include "sqlite3.h"
#if SQLITE_USER_AUTHENTICATION
# include "sqlite3userauth.h"
#endif
#include <ctype.h>
#include <stdarg.h>

#if !defined(_WIN32) && !defined(WIN32)
# include <signal.h>
# if !defined(__RTP__) && !defined(_WRS_KERNEL)
#  include <pwd.h>

      sqlite3_trace(p->db, 0, 0);
    }else{
      sqlite3_trace(p->db, sql_trace_callback, p->traceOut);
    }
#endif
  }else

#if SQLITE_USER_AUTHENTICATION
  if( c=='u' && strncmp(azArg[0], "user", n)==0 ){
    if( nArg<2 ){
      fprintf(stderr, "Usage: .user SUBCOMMAND ...\n");
      rc = 1;
      goto meta_command_exit;
    }
    open_db(p, 0);
    if( strcmp(azArg[1],"login")==0 ){
      if( nArg!=4 ){
        fprintf(stderr, "Usage: .user login USER PASSWORD\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_authenticate(p->db, azArg[2], azArg[3],
                                    (int)strlen(azArg[3]));
      if( rc ){
        fprintf(stderr, "Authentication failed for user %s\n", azArg[2]);
        rc = 1;
      }
    }else if( strcmp(azArg[1],"add")==0 ){
      if( nArg!=5 ){
        fprintf(stderr, "Usage: .user add USER PASSWORD ISADMIN\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_add(p->db, azArg[2],
                            azArg[3], (int)strlen(azArg[3]),
                            booleanValue(azArg[4]));
      if( rc ){
        fprintf(stderr, "User-Add failed: %d\n", rc);
        rc = 1;
      }
    }else if( strcmp(azArg[1],"edit")==0 ){
      if( nArg!=5 ){
        fprintf(stderr, "Usage: .user edit USER PASSWORD ISADMIN\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_change(p->db, azArg[2],
                              azArg[3], (int)strlen(azArg[3]),
                              booleanValue(azArg[4]));
      if( rc ){
        fprintf(stderr, "User-Edit failed: %d\n", rc);
        rc = 1;
      }
    }else if( strcmp(azArg[1],"delete")==0 ){
      if( nArg!=3 ){
        fprintf(stderr, "Usage: .user delete USER\n");
        rc = 1;
        goto meta_command_exit;
      }
      rc = sqlite3_user_delete(p->db, azArg[2]);
      if( rc ){
        fprintf(stderr, "User-Delete failed: %d\n", rc);
        rc = 1;
      }
    }else{
      fprintf(stderr, "Usage: .user login|add|edit|delete ...\n");
      rc = 1;
      goto meta_command_exit;
    }    
  }else
#endif /* SQLITE_USER_AUTHENTICATION */

  if( c=='v' && strncmp(azArg[0], "version", n)==0 ){
    fprintf(p->out, "SQLite %s %s\n" /*extra-version-info*/,
        sqlite3_libversion(), sqlite3_sourceid());
  }else

  if( c=='v' && strncmp(azArg[0], "vfsname", n)==0 ){
    const char *zDbName = nArg==2 ? azArg[1] : "main";

#define SQLITE_CONSTRAINT_TRIGGER      (SQLITE_CONSTRAINT | (7<<8))
#define SQLITE_CONSTRAINT_UNIQUE       (SQLITE_CONSTRAINT | (8<<8))
#define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
#define SQLITE_CONSTRAINT_ROWID        (SQLITE_CONSTRAINT |(10<<8))
#define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
#define SQLITE_AUTH_USER               (SQLITE_AUTH | (1<<8))

/*
** CAPI3REF: Flags For File Open Operations
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the [sqlite3_vfs.xOpen] method.

** the handler returns 0 which causes [sqlite3_step()] to return
** [SQLITE_BUSY].
**
** ^Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** ^(There can only be a single busy handler for a particular
** [database connection] at any given moment.  If another busy handler
** was defined  (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.)^
**
** See also:  [PRAGMA busy_timeout]
*/
int sqlite3_busy_timeout(sqlite3*, int ms);

**
** ^The sqlite3_malloc() routine returns a pointer to a block
** of memory at least N bytes in length, where N is the parameter.
** ^If sqlite3_malloc() is unable to obtain sufficient free
** memory, it returns a NULL pointer.  ^If the parameter N to
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
** a NULL pointer.
**
** ^The sqlite3_malloc64(N) routine works just like
** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
** of a signed 32-bit integer.
**
** ^Calling sqlite3_free() with a pointer previously returned
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
** that it might be reused.  ^The sqlite3_free() routine is
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
** to sqlite3_free() is harmless.  After being freed, memory
** should neither be read nor written.  Even reading previously freed
** memory might result in a segmentation fault or other severe error.
** Memory corruption, a segmentation fault, or other severe error
** might result if sqlite3_free() is called with a non-NULL pointer that
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
**
** ^The sqlite3_realloc(X,N) interface attempts to resize a
** prior memory allocation X to be at least N bytes.

** ^If the X parameter to sqlite3_realloc(X,N)
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N).
** ^If the N parameter to sqlite3_realloc(X,N) is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(X).
** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
** of at least N bytes in size or NULL if insufficient memory is available.
** ^If M is the size of the prior allocation, then min(N,M) bytes
** of the prior allocation are copied into the beginning of buffer returned
** by sqlite3_realloc(X,N) and the prior allocation is freed.
** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
** prior allocation is not freed.
**
** ^The sqlite3_realloc64(X,N) interfaces works the same as
** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
** of a 32-bit signed integer.
**
** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
** sqlite3_msize(X) returns the size of that memory allocation in bytes.
** ^The value returned by sqlite3_msize(X) might be larger than the number
** of bytes requested when X was allocated.  ^If X is a NULL pointer then
** sqlite3_msize(X) returns zero.  If X points to something that is not
** the beginning of memory allocation, or if it points to a formerly
** valid memory allocation that has now been freed, then the behavior
** of sqlite3_msize(X) is undefined and possibly harmful.
**
** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
** sqlite3_malloc64(), and sqlite3_realloc64()
** is always aligned to at least an 8 byte boundary, or to a
** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
** option is used.
**
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
** implementation of these routines to be omitted.  That capability

** not yet been released.
**
** The application must not read or write any part of
** a block of memory after it has been released using
** [sqlite3_free()] or [sqlite3_realloc()].
*/
void *sqlite3_malloc(int);
void *sqlite3_malloc64(sqlite3_uint64);
void *sqlite3_realloc(void*, int);
void *sqlite3_realloc64(void*, sqlite3_uint64);
void sqlite3_free(void*);
sqlite3_uint64 sqlite3_msize(void*);

/*
** CAPI3REF: Memory Allocator Statistics
**
** SQLite provides these two interfaces for reporting on the status
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
** routines, which form the built-in memory allocation subsystem.

** number of <u>bytes</u> in the value, not the number of characters.)^
** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
** is negative, then the length of the string is
** the number of bytes up to the first zero terminator.
** If the fourth parameter to sqlite3_bind_blob() is negative, then
** the behavior is undefined.
** If a non-negative fourth parameter is provided to sqlite3_bind_text()
** or sqlite3_bind_text16() or sqlite3_bind_text64() then
** that parameter must be the byte offset
** where the NUL terminator would occur assuming the string were NUL
** terminated.  If any NUL characters occur at byte offsets less than 
** the value of the fourth parameter then the resulting string value will
** contain embedded NULs.  The result of expressions involving strings
** with embedded NULs is undefined.
**
** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
** string after SQLite has finished with it.  ^The destructor is called
** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
** sqlite3_bind_text(), or sqlite3_bind_text16() fails.  
** ^If the fifth argument is
** the special value [SQLITE_STATIC], then SQLite assumes that the
** information is in static, unmanaged space and does not need to be freed.
** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
** SQLite makes its own private copy of the data immediately, before
** the sqlite3_bind_*() routine returns.
**
** ^The sixth argument to sqlite3_bind_text64() must be one of
** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
** to specify the encoding of the text in the third parameter.  If
** the sixth argument to sqlite3_bind_text64() is not how of the
** allowed values shown above, or if the text encoding is different
** from the encoding specified by the sixth parameter, then the behavior
** is undefined.
**
** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
** (just an integer to hold its size) while it is being processed.
** Zeroblobs are intended to serve as placeholders for BLOBs whose
** content is later written using
** [sqlite3_blob_open | incremental BLOB I/O] routines.

** result is undefined and probably harmful.
**
** ^Bindings are not cleared by the [sqlite3_reset()] routine.
** ^Unbound parameters are interpreted as NULL.
**
** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
** [error code] if anything goes wrong.
** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
** [SQLITE_MAX_LENGTH].
** ^[SQLITE_RANGE] is returned if the parameter
** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.
**
** See also: [sqlite3_bind_parameter_count()],
** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
*/
int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
                        void(*)(void*));
int sqlite3_bind_double(sqlite3_stmt*, int, double);
int sqlite3_bind_int(sqlite3_stmt*, int, int);
int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
int sqlite3_bind_null(sqlite3_stmt*, int);
int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
                         void(*)(void*), unsigned char encoding);
int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

/*
** CAPI3REF: Number Of SQL Parameters
**
** ^This routine can be used to find the number of [SQL parameters]

** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.
**
** ^These routines work just like the corresponding [column access functions]
** except that these routines take a single [protected sqlite3_value] object
** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
**
** ^The sqlite3_value_text16() interface extracts a UTF-16 string
** in the native byte-order of the host machine.  ^The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF-16 strings as big-endian and little-endian respectively.
**

** of the application-defined function to be the 64-bit signed integer
** value given in the 2nd argument.
**
** ^The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** ^The sqlite3_result_text(), sqlite3_result_text16(),
** sqlite3_result_text16le(), and sqlite3_result_text16be()
** set the return value of the application-defined function to be
** a text string which is represented as UTF-8, UTF-16 native byte order,
** UTF-16 little endian, or UTF-16 big endian, respectively.
** ^The sqlite3_result_text64() interface sets the return value of an
** application-defined function to be a text string in an encoding
** specified by the fifth (and last) parameter, which must be one
** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
** ^SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
** is negative, then SQLite takes result text from the 2nd parameter
** through the first zero character.
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
** is non-negative, then as many bytes (not characters) of the text

** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread
** than the one containing the application-defined function that received
** the [sqlite3_context] pointer, the results are undefined.
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_blob64(sqlite3_context*,const void*,sqlite3_uint64,void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
void sqlite3_result_error_code(sqlite3_context*, int);
void sqlite3_result_int(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
void sqlite3_result_null(sqlite3_context*);
void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
                           void(*)(void*), unsigned char encoding);
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);

/*

** <dd>This parameter returns the number malloc attempts that might have
** been satisfied using lookaside memory but failed due to all lookaside
** memory already being in use.
** Only the high-water value is meaningful;
** the current value is always zero.)^
**
** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
** <dd>This parameter returns the approximate number of bytes of heap
** memory used by all pager caches associated with the database connection.)^
** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
**
** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
** <dd>This parameter returns the approximate number of bytes of heap
** memory used to store the schema for all databases associated
** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 
** ^The full amount of memory used by the schemas is reported, even if the
** schema memory is shared with other database connections due to
** [shared cache mode] being enabled.
** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
**
** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
** <dd>This parameter returns the approximate number of bytes of heap
** and lookaside memory used by all prepared statements associated with
** the database connection.)^
** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
** </dd>
**
** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
** <dd>This parameter returns the number of pager cache hits that have

/*
** The following structure holds pointers to all of the SQLite API
** routines.
**
** WARNING:  In order to maintain backwards compatibility, add new
** interfaces to the end of this structure only.  If you insert new
** interfaces in the middle of this structure, then older different
** versions of SQLite will not be able to load each other's shared
** libraries!
*/
struct sqlite3_api_routines {
  void * (*aggregate_context)(sqlite3_context*,int nBytes);
  int  (*aggregate_count)(sqlite3_context*);
  int  (*bind_blob)(sqlite3_stmt*,int,const void*,int n,void(*)(void*));
  int  (*bind_double)(sqlite3_stmt*,int,double);

  int (*stmt_readonly)(sqlite3_stmt*);
  int (*stricmp)(const char*,const char*);
  int (*uri_boolean)(const char*,const char*,int);
  sqlite3_int64 (*uri_int64)(const char*,const char*,sqlite3_int64);
  const char *(*uri_parameter)(const char*,const char*);
  char *(*vsnprintf)(int,char*,const char*,va_list);
  int (*wal_checkpoint_v2)(sqlite3*,const char*,int,int*,int*);
  /* Version 3.8.7 and later */
  int (*auto_extension)(void(*)(void));
  int (*bind_blob64)(sqlite3_stmt*,int,const void*,sqlite3_uint64,
                     void(*)(void*));
  int (*bind_text64)(sqlite3_stmt*,int,const char*,sqlite3_uint64,
                      void(*)(void*),unsigned char);
  int (*cancel_auto_extension)(void(*)(void));
  int (*load_extension)(sqlite3*,const char*,const char*,char**);
  void *(*malloc64)(sqlite3_uint64);
  sqlite3_uint64 (*msize)(void*);
  void *(*realloc64)(void*,sqlite3_uint64);
  void (*reset_auto_extension)(void);
  void (*result_blob64)(sqlite3_context*,const void*,sqlite3_uint64,
                        void(*)(void*));
  void (*result_text64)(sqlite3_context*,const char*,sqlite3_uint64,
                         void(*)(void*), unsigned char);
  int (*strglob)(const char*,const char*);
};

/*
** The following macros redefine the API routines so that they are
** redirected through the global sqlite3_api structure.
**
** This header file is also used by the loadext.c source file
** (part of the main SQLite library - not an extension) so that
** it can get access to the sqlite3_api_routines structure
** definition.  But the main library does not want to redefine
** the API.  So the redefinition macros are only valid if the
** SQLITE_CORE macros is undefined.

#define sqlite3_stmt_readonly          sqlite3_api->stmt_readonly
#define sqlite3_stricmp                sqlite3_api->stricmp
#define sqlite3_uri_boolean            sqlite3_api->uri_boolean
#define sqlite3_uri_int64              sqlite3_api->uri_int64
#define sqlite3_uri_parameter          sqlite3_api->uri_parameter
#define sqlite3_uri_vsnprintf          sqlite3_api->vsnprintf
#define sqlite3_wal_checkpoint_v2      sqlite3_api->wal_checkpoint_v2
/* Version 3.8.7 and later */
#define sqlite3_auto_extension         sqlite3_api->auto_extension
#define sqlite3_bind_blob64            sqlite3_api->bind_blob64
#define sqlite3_bind_text64            sqlite3_api->bind_text64
#define sqlite3_cancel_auto_extension  sqlite3_api->cancel_auto_extension
#define sqlite3_load_extension         sqlite3_api->load_extension
#define sqlite3_malloc64               sqlite3_api->malloc64
#define sqlite3_msize                  sqlite3_api->msize
#define sqlite3_realloc64              sqlite3_api->realloc64
#define sqlite3_reset_auto_extension   sqlite3_api->reset_auto_extension
#define sqlite3_result_blob64          sqlite3_api->result_blob64
#define sqlite3_result_text64          sqlite3_api->result_text64
#define sqlite3_strglob                sqlite3_api->strglob
#endif /* SQLITE_CORE */

#ifndef SQLITE_CORE
  /* This case when the file really is being compiled as a loadable 
  ** extension */
# define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;
# define SQLITE_EXTENSION_INIT2(v)  sqlite3_api=v;

# define NEVER(X)       ((X)?(assert(0),1):0)
#else
# define ALWAYS(X)      (X)
# define NEVER(X)       (X)
#endif

/*
** Return true (non-zero) if the input is an integer that is too large
** to fit in 32-bits.  This macro is used inside of various testcase()
** macros to verify that we have tested SQLite for large-file support.
*/
#define IS_BIG_INT(X)  (((X)&~(i64)0xffffffff)!=0)

/*
** The macro unlikely() is a hint that surrounds a boolean

/*
** Assert that the pointer X is aligned to an 8-byte boundary.  This
** macro is used only within assert() to verify that the code gets
** all alignment restrictions correct.
**
** Except, if SQLITE_4_BYTE_ALIGNED_MALLOC is defined, then the
** underlying malloc() implementation might return us 4-byte aligned
** pointers.  In that case, only verify 4-byte alignment.
*/
#ifdef SQLITE_4_BYTE_ALIGNED_MALLOC
# define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&3)==0)
#else
# define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
#endif

**
** Hash each FuncDef structure into one of the FuncDefHash.a[] slots.
** Collisions are on the FuncDef.pHash chain.
*/
struct FuncDefHash {
  FuncDef *a[23];       /* Hash table for functions */
};

#ifdef SQLITE_USER_AUTHENTICATION
/*
** Information held in the "sqlite3" database connection object and used
** to manage user authentication.
*/
typedef struct sqlite3_userauth sqlite3_userauth;
struct sqlite3_userauth {
  u8 authLevel;                 /* Current authentication level */
  int nAuthPW;                  /* Size of the zAuthPW in bytes */
  char *zAuthPW;                /* Password used to authenticate */
  char *zAuthUser;              /* User name used to authenticate */
};

/* Allowed values for sqlite3_userauth.authLevel */
#define UAUTH_Unknown     0     /* Authentication not yet checked */
#define UAUTH_Fail        1     /* User authentication failed */
#define UAUTH_User        2     /* Authenticated as a normal user */
#define UAUTH_Admin       3     /* Authenticated as an administrator */

/* Functions used only by user authorization logic */
int sqlite3UserAuthTable(const char*);
int sqlite3UserAuthCheckLogin(sqlite3*,const char*,u8*);
void sqlite3UserAuthInit(sqlite3*);
void sqlite3CryptFunc(sqlite3_context*,int,sqlite3_value**);

#endif /* SQLITE_USER_AUTHENTICATION */

/*
** typedef for the authorization callback function.
*/
#ifdef SQLITE_USER_AUTHENTICATION
  typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,
                               const char*, const char*);
#else
  typedef int (*sqlite3_xauth)(void*,int,const char*,const char*,const char*,
                               const char*);
#endif


/*
** Each database connection is an instance of the following structure.
*/
struct sqlite3 {
  sqlite3_vfs *pVfs;            /* OS Interface */
  struct Vdbe *pVdbe;           /* List of active virtual machines */

  sqlite3_value *pErr;          /* Most recent error message */
  union {
    volatile int isInterrupted; /* True if sqlite3_interrupt has been called */
    double notUsed1;            /* Spacer */
  } u1;
  Lookaside lookaside;          /* Lookaside malloc configuration */
#ifndef SQLITE_OMIT_AUTHORIZATION

  sqlite3_xauth xAuth;          /* Access authorization function */
  void *pAuthArg;               /* 1st argument to the access auth function */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int (*xProgress)(void *);     /* The progress callback */
  void *pProgressArg;           /* Argument to the progress callback */
  unsigned nProgressOps;        /* Number of opcodes for progress callback */
#endif

  Savepoint *pSavepoint;        /* List of active savepoints */
  int busyTimeout;              /* Busy handler timeout, in msec */
  int nSavepoint;               /* Number of non-transaction savepoints */
  int nStatement;               /* Number of nested statement-transactions  */
  i64 nDeferredCons;            /* Net deferred constraints this transaction. */
  i64 nDeferredImmCons;         /* Net deferred immediate constraints */
  int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */

#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
  /* The following variables are all protected by the STATIC_MASTER 
  ** mutex, not by sqlite3.mutex. They are used by code in notify.c. 
  **
  ** When X.pUnlockConnection==Y, that means that X is waiting for Y to
  ** unlock so that it can proceed.
  **
  ** When X.pBlockingConnection==Y, that means that something that X tried
  ** tried to do recently failed with an SQLITE_LOCKED error due to locks
  ** held by Y.
  */
  sqlite3 *pBlockingConnection; /* Connection that caused SQLITE_LOCKED */
  sqlite3 *pUnlockConnection;           /* Connection to watch for unlock */
  void *pUnlockArg;                     /* Argument to xUnlockNotify */
  void (*xUnlockNotify)(void **, int);  /* Unlock notify callback */
  sqlite3 *pNextBlocked;        /* Next in list of all blocked connections */
#endif
#ifdef SQLITE_USER_AUTHENTICATION
  sqlite3_userauth auth;        /* User authentication information */
#endif
};

/*
** A macro to discover the encoding of a database.
*/
#define ENC(db) ((db)->aDb[0].pSchema->enc)

#define SQLITE_DistinctOpt    0x0020   /* DISTINCT using indexes */
#define SQLITE_CoverIdxScan   0x0040   /* Covering index scans */
#define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
#define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
#define SQLITE_Transitive     0x0200   /* Transitive constraints */
#define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
#define SQLITE_Stat3          0x0800   /* Use the SQLITE_STAT3 table */

#define SQLITE_AllOpts        0xffff   /* All optimizations */

/*
** Macros for testing whether or not optimizations are enabled or disabled.
*/
#ifndef SQLITE_OMIT_BUILTIN_TEST
#define OptimizationDisabled(db, mask)  (((db)->dbOptFlags&(mask))!=0)

#define SQLITE_FUNC_NEEDCOLL 0x020 /* sqlite3GetFuncCollSeq() might be called */
#define SQLITE_FUNC_LENGTH   0x040 /* Built-in length() function */
#define SQLITE_FUNC_TYPEOF   0x080 /* Built-in typeof() function */
#define SQLITE_FUNC_COUNT    0x100 /* Built-in count(*) aggregate */
#define SQLITE_FUNC_COALESCE 0x200 /* Built-in coalesce() or ifnull() */
#define SQLITE_FUNC_UNLIKELY 0x400 /* Built-in unlikely() function */
#define SQLITE_FUNC_CONSTANT 0x800 /* Constant inputs give a constant output */
#define SQLITE_FUNC_MINMAX  0x1000 /* True for min() and max() aggregates */

/*
** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
** used to create the initializers for the FuncDef structures.
**
**   FUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Used to create a scalar function definition of a function zName 

  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|(bNC*SQLITE_FUNC_NEEDCOLL), \
   pArg, 0, xFunc, 0, 0, #zName, 0, 0}
#define LIKEFUNC(zName, nArg, arg, flags) \
  {nArg, SQLITE_FUNC_CONSTANT|SQLITE_UTF8|flags, \
   (void *)arg, 0, likeFunc, 0, 0, #zName, 0, 0}
#define AGGREGATE(zName, nArg, arg, nc, xStep, xFinal) \
  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL), \
   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}
#define AGGREGATE2(zName, nArg, arg, nc, xStep, xFinal, extraFlags) \
  {nArg, SQLITE_UTF8|(nc*SQLITE_FUNC_NEEDCOLL)|extraFlags, \
   SQLITE_INT_TO_PTR(arg), 0, 0, xStep,xFinal,#zName,0,0}

/*
** All current savepoints are stored in a linked list starting at
** sqlite3.pSavepoint. The first element in the list is the most recently
** opened savepoint. Savepoints are added to the list by the vdbe
** OP_Savepoint instruction.

  Parse *pParse;       /* The parser */
  SrcList *pSrcList;   /* One or more tables used to resolve names */
  ExprList *pEList;    /* Optional list of result-set columns */
  AggInfo *pAggInfo;   /* Information about aggregates at this level */
  NameContext *pNext;  /* Next outer name context.  NULL for outermost */
  int nRef;            /* Number of names resolved by this context */
  int nErr;            /* Number of errors encountered while resolving names */
  u16 ncFlags;         /* Zero or more NC_* flags defined below */
};

/*
** Allowed values for the NameContext, ncFlags field.
**
** Note:  NC_MinMaxAgg must have the same value as SF_MinMaxAgg and
** SQLITE_FUNC_MINMAX.
** 
*/
#define NC_AllowAgg  0x0001  /* Aggregate functions are allowed here */
#define NC_HasAgg    0x0002  /* One or more aggregate functions seen */
#define NC_IsCheck   0x0004  /* True if resolving names in a CHECK constraint */
#define NC_InAggFunc 0x0008  /* True if analyzing arguments to an agg func */
#define NC_PartIdx   0x0010  /* True if resolving a partial index WHERE */
#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**
** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
** If there is a LIMIT clause, the parser sets nLimit to the value of the

*/
#define SF_Distinct        0x0001  /* Output should be DISTINCT */
#define SF_Resolved        0x0002  /* Identifiers have been resolved */
#define SF_Aggregate       0x0004  /* Contains aggregate functions */
#define SF_UsesEphemeral   0x0008  /* Uses the OpenEphemeral opcode */
#define SF_Expanded        0x0010  /* sqlite3SelectExpand() called on this */
#define SF_HasTypeInfo     0x0020  /* FROM subqueries have Table metadata */
#define SF_Compound        0x0040  /* Part of a compound query */
#define SF_Values          0x0080  /* Synthesized from VALUES clause */
                    /*     0x0100  NOT USED */
#define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
#define SF_MaybeConvert    0x0400  /* Need convertCompoundSelectToSubquery() */
#define SF_Recursive       0x0800  /* The recursive part of a recursive CTE */
#define SF_MinMaxAgg       0x1000  /* Aggregate containing min() or max() */


/*
** The results of a SELECT can be distributed in several ways, as defined
** by one of the following macros.  The "SRT" prefix means "SELECT Result
** Type".
**

#define SQLITE_CORRUPT_BKPT sqlite3CorruptError(__LINE__)
#define SQLITE_MISUSE_BKPT sqlite3MisuseError(__LINE__)
#define SQLITE_CANTOPEN_BKPT sqlite3CantopenError(__LINE__)


/*
** FTS4 is really an extension for FTS3.  It is enabled using the
** SQLITE_ENABLE_FTS3 macro.  But to avoid confusion we also call
** the SQLITE_ENABLE_FTS4 macro to serve as an alias for SQLITE_ENABLE_FTS3.
*/
#if defined(SQLITE_ENABLE_FTS4) && !defined(SQLITE_ENABLE_FTS3)
# define SQLITE_ENABLE_FTS3
#endif

/*
** The ctype.h header is needed for non-ASCII systems.  It is also

*/
#define sqlite3StrICmp sqlite3_stricmp
int sqlite3Strlen30(const char*);
#define sqlite3StrNICmp sqlite3_strnicmp

int sqlite3MallocInit(void);
void sqlite3MallocEnd(void);
void *sqlite3Malloc(u64);
void *sqlite3MallocZero(u64);
void *sqlite3DbMallocZero(sqlite3*, u64);
void *sqlite3DbMallocRaw(sqlite3*, u64);
char *sqlite3DbStrDup(sqlite3*,const char*);
char *sqlite3DbStrNDup(sqlite3*,const char*, u64);
void *sqlite3Realloc(void*, u64);
void *sqlite3DbReallocOrFree(sqlite3 *, void *, u64);
void *sqlite3DbRealloc(sqlite3 *, void *, u64);
void sqlite3DbFree(sqlite3*, void*);
int sqlite3MallocSize(void*);
int sqlite3DbMallocSize(sqlite3*, void*);
void *sqlite3ScratchMalloc(int);
void sqlite3ScratchFree(void*);
void *sqlite3PageMalloc(int);
void sqlite3PageFree(void*);

void sqlite3Stat4ProbeFree(UnpackedRecord*);
int sqlite3Stat4Column(sqlite3*, const void*, int, int, sqlite3_value**);
#endif

/*
** The interface to the LEMON-generated parser
*/
void *sqlite3ParserAlloc(void*(*)(u64));
void sqlite3ParserFree(void*, void(*)(void*));
void sqlite3Parser(void*, int, Token, Parse*);
#ifdef YYTRACKMAXSTACKDEPTH
  int sqlite3ParserStackPeak(void*);
#endif

void sqlite3AutoLoadExtensions(sqlite3*);

/*
** This structure is used to pass data from sqlite3_get_table() through
** to the callback function is uses to build the result.
*/
typedef struct TabResult {
  char **azResult;   /* Accumulated output */
  char *zErrMsg;     /* Error message text, if an error occurs */
  u32 nAlloc;        /* Slots allocated for azResult[] */
  u32 nRow;          /* Number of rows in the result */
  u32 nColumn;       /* Number of columns in the result */
  u32 nData;         /* Slots used in azResult[].  (nRow+1)*nColumn */
  int rc;            /* Return code from sqlite3_exec() */
} TabResult;

/*
** This routine is called once for each row in the result table.  Its job
** is to fill in the TabResult structure appropriately, allocating new
** memory as necessary.

    need = nCol*2;
  }else{
    need = nCol;
  }
  if( p->nData + need > p->nAlloc ){
    char **azNew;
    p->nAlloc = p->nAlloc*2 + need;
    azNew = sqlite3_realloc64( p->azResult, sizeof(char*)*p->nAlloc );
    if( azNew==0 ) goto malloc_failed;
    p->azResult = azNew;
  }

  /* If this is the first row, then generate an extra row containing
  ** the names of all columns.
  */

  return rc;
}

/*
** This routine frees the space the sqlite3_get_table() malloced.
*/
void sqlite3_free_table(
  char **azResult            /* Result returned from sqlite3_get_table() */
){
  if( azResult ){
    int i, n;
    azResult--;
    assert( azResult!=0 );
    n = SQLITE_PTR_TO_INT(azResult[0]);
    for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
    sqlite3_free(azResult);
  }
}

#endif /* SQLITE_OMIT_GET_TABLE */

    Tcl_IncrRefCount(pCmd);
    rc = Tcl_EvalObjEx(p->interp, pCmd, 0);
    Tcl_DecrRefCount(pCmd);
  }else{
    /* If there are arguments to the function, make a shallow copy of the
    ** script object, lappend the arguments, then evaluate the copy.
    **
    ** By "shallow" copy, we mean only the outer list Tcl_Obj is duplicated.
    ** The new Tcl_Obj contains pointers to the original list elements. 
    ** That way, when Tcl_EvalObjv() is run and shimmers the first element
    ** of the list to tclCmdNameType, that alternate representation will
    ** be preserved and reused on the next invocation.
    */
    Tcl_Obj **aArg;
    int nArg;

static int auth_callback(
  void *pArg,
  int code,
  const char *zArg1,
  const char *zArg2,
  const char *zArg3,
  const char *zArg4
#ifdef SQLITE_USER_AUTHENTICATION
  ,const char *zArg5
#endif
){
  const char *zCode;
  Tcl_DString str;
  int rc;
  const char *zReply;
  SqliteDb *pDb = (SqliteDb*)pArg;
  if( pDb->disableAuth ) return SQLITE_OK;

  Tcl_DStringInit(&str);
  Tcl_DStringAppend(&str, pDb->zAuth, -1);
  Tcl_DStringAppendElement(&str, zCode);
  Tcl_DStringAppendElement(&str, zArg1 ? zArg1 : "");
  Tcl_DStringAppendElement(&str, zArg2 ? zArg2 : "");
  Tcl_DStringAppendElement(&str, zArg3 ? zArg3 : "");
  Tcl_DStringAppendElement(&str, zArg4 ? zArg4 : "");
#ifdef SQLITE_USER_AUTHENTICATION
  Tcl_DStringAppendElement(&str, zArg5 ? zArg5 : "");
#endif  
  rc = Tcl_GlobalEval(pDb->interp, Tcl_DStringValue(&str));
  Tcl_DStringFree(&str);
  zReply = rc==TCL_OK ? Tcl_GetStringResult(pDb->interp) : "SQLITE_DENY";
  if( strcmp(zReply,"SQLITE_OK")==0 ){
    rc = SQLITE_OK;
  }else if( strcmp(zReply,"SQLITE_DENY")==0 ){
    rc = SQLITE_DENY;

      if( zAuth && len>0 ){
        pDb->zAuth = Tcl_Alloc( len + 1 );
        memcpy(pDb->zAuth, zAuth, len+1);
      }else{
        pDb->zAuth = 0;
      }
      if( pDb->zAuth ){
        typedef int (*sqlite3_auth_cb)(
           void*,int,const char*,const char*,
           const char*,const char*);
        pDb->interp = interp;
        sqlite3_set_authorizer(pDb->db,(sqlite3_auth_cb)auth_callback,pDb);
      }else{
        sqlite3_set_authorizer(pDb->db, 0, 0);
      }
    }
#endif
    break;
  }

**   "test_collate <enc> <lhs> <rhs>"
**
** The <lhs> and <rhs> are the two values being compared, encoded in UTF-8.
** The <enc> parameter is the encoding of the collation function that
** SQLite selected to call. The TCL test script implements the
** "test_collate" proc.
**
** Note that this will only work with one interpreter at a time, as the
** interp pointer to use when evaluating the TCL script is stored in
** pTestCollateInterp.
*/
static Tcl_Interp* pTestCollateInterp;
static int test_collate_func(
  void *pCtx, 
  int nA, const void *zA,

  return TCL_OK;
}

/*
** Usage: sqlite3_prepare_tkt3134 DB
**
** Generate a prepared statement for a zero-byte string as a test
** for ticket #3134.  The string should be preceded by a zero byte.
*/
static int test_prepare_tkt3134(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){

    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
    return TCL_ERROR;
  }

  return TCL_OK;
}

#ifdef SQLITE_USER_AUTHENTICATION
#include "sqlite3userauth.h"
/*
** tclcmd:  sqlite3_user_authenticate DB USERNAME PASSWORD
*/
static int test_user_authenticate(
  ClientData clientData, /* Unused */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  char *zUser = 0;
  char *zPasswd = 0;
  int nPasswd = 0;
  sqlite3 *db;
  int rc;

  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB USERNAME PASSWORD");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  zUser = Tcl_GetString(objv[2]);
  zPasswd = Tcl_GetStringFromObj(objv[3], &nPasswd);
  rc = sqlite3_user_authenticate(db, zUser, zPasswd, nPasswd);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}
#endif /* SQLITE_USER_AUTHENTICATION */

#ifdef SQLITE_USER_AUTHENTICATION
/*
** tclcmd:  sqlite3_user_add DB USERNAME PASSWORD ISADMIN
*/
static int test_user_add(
  ClientData clientData, /* Unused */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  char *zUser = 0;
  char *zPasswd = 0;
  int nPasswd = 0;
  int isAdmin = 0;
  sqlite3 *db;
  int rc;

  if( objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB USERNAME PASSWORD ISADMIN");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  zUser = Tcl_GetString(objv[2]);
  zPasswd = Tcl_GetStringFromObj(objv[3], &nPasswd);
  Tcl_GetBooleanFromObj(interp, objv[4], &isAdmin);
  rc = sqlite3_user_add(db, zUser, zPasswd, nPasswd, isAdmin);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}
#endif /* SQLITE_USER_AUTHENTICATION */

#ifdef SQLITE_USER_AUTHENTICATION
/*
** tclcmd:  sqlite3_user_change DB USERNAME PASSWORD ISADMIN
*/
static int test_user_change(
  ClientData clientData, /* Unused */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  char *zUser = 0;
  char *zPasswd = 0;
  int nPasswd = 0;
  int isAdmin = 0;
  sqlite3 *db;
  int rc;

  if( objc!=5 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB USERNAME PASSWORD ISADMIN");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  zUser = Tcl_GetString(objv[2]);
  zPasswd = Tcl_GetStringFromObj(objv[3], &nPasswd);
  Tcl_GetBooleanFromObj(interp, objv[4], &isAdmin);
  rc = sqlite3_user_change(db, zUser, zPasswd, nPasswd, isAdmin);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}
#endif /* SQLITE_USER_AUTHENTICATION */

#ifdef SQLITE_USER_AUTHENTICATION
/*
** tclcmd:  sqlite3_user_delete DB USERNAME
*/
static int test_user_delete(
  ClientData clientData, /* Unused */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  char *zUser = 0;
  sqlite3 *db;
  int rc;

  if( objc!=3 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB USERNAME");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  zUser = Tcl_GetString(objv[2]);
  rc = sqlite3_user_delete(db, zUser);
  Tcl_SetResult(interp, (char *)t1ErrorName(rc), TCL_STATIC);
  return TCL_OK;
}
#endif /* SQLITE_USER_AUTHENTICATION */

/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest1_Init(Tcl_Interp *interp){
  extern int sqlite3_search_count;
  extern int sqlite3_found_count;
  extern int sqlite3_interrupt_count;

     { "getrusage", test_getrusage },
#endif
     { "load_static_extension", tclLoadStaticExtensionCmd },
     { "sorter_test_fakeheap", sorter_test_fakeheap },
     { "sorter_test_sort4_helper", sorter_test_sort4_helper },
     { "sqlite3_transaction_save",    testTransactionSave },
     { "sqlite3_transaction_restore", testTransactionRestore },
#ifdef SQLITE_USER_AUTHENTICATION
     { "sqlite3_user_authenticate", test_user_authenticate, 0 },
     { "sqlite3_user_add",          test_user_add,          0 },
     { "sqlite3_user_change",       test_user_change,       0 },
     { "sqlite3_user_delete",       test_user_delete,       0 },
#endif
  };

  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;
  extern int sqlite3_opentemp_count;
  extern int sqlite3_like_count;
  extern int sqlite3_xferopt_count;
  extern int sqlite3_pager_readdb_count;

#endif

#ifdef SQLITE_SECURE_DELETE
  Tcl_SetVar2(interp, "sqlite_options", "secure_delete", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "secure_delete", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_USER_AUTHENTICATION
  Tcl_SetVar2(interp, "sqlite_options", "userauth", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "userauth", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_MULTIPLEX_EXT_OVWR
  Tcl_SetVar2(interp, "sqlite_options", "multiplex_ext_overwrite", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "multiplex_ext_overwrite", "0", TCL_GLOBAL_ONLY);
#endif

  void (*xFree)(void*);     /* Function used to free a[] */
};

/* Objects used internally by the virtual table implementation */
typedef struct intarray_vtab intarray_vtab;
typedef struct intarray_cursor intarray_cursor;

/* An intarray table object */
struct intarray_vtab {
  sqlite3_vtab base;            /* Base class */
  sqlite3_intarray *pContent;   /* Content of the integer array */
};

/* An intarray cursor object */
struct intarray_cursor {
  sqlite3_vtab_cursor base;    /* Base class */
  int i;                       /* Current cursor position */
};

/*
** None of this works unless we have virtual tables.

    return TCL_ERROR;
  }
  nPending = faultsimPending();
  Tcl_SetObjResult(interp, Tcl_NewIntObj(nPending));
  return TCL_OK;
}

/*
** The following global variable keeps track of the number of tests
** that have run.  This variable is only useful when running in the
** debugger.
*/
static int sqlite3_memdebug_title_count = 0;

/*
** Usage:    sqlite3_memdebug_settitle TITLE
**
** Set a title string stored with each allocation.  The TITLE is
** typically the name of the test that was running when the
** allocation occurred.  The TITLE is stored with the allocation
** and can be used to figure out which tests are leaking memory.
**
** Each title overwrite the previous.
*/
static int test_memdebug_settitle(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3_memdebug_title_count++;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "TITLE");
    return TCL_ERROR;
  }
#ifdef SQLITE_MEMDEBUG
  {
    const char *zTitle;

}

/*
** Usage:    sqlite3_config_scratch SIZE N
**
** Set the scratch memory buffer using SQLITE_CONFIG_SCRATCH.
** The buffer is static and is of limited size.  N might be
** adjusted downward as needed to accommodate the requested size.
** The revised value of N is returned.
**
** A negative SIZE causes the buffer pointer to be NULL.
*/
static int test_config_scratch(
  void * clientData,
  Tcl_Interp *interp,

}

/*
** Usage:    sqlite3_config_pagecache SIZE N
**
** Set the page-cache memory buffer using SQLITE_CONFIG_PAGECACHE.
** The buffer is static and is of limited size.  N might be
** adjusted downward as needed to accommodate the requested size.
** The revised value of N is returned.
**
** A negative SIZE causes the buffer pointer to be NULL.
*/
static int test_config_pagecache(
  void * clientData,
  Tcl_Interp *interp,

      while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){
        rc = finalize(&pCur->pDbList);
        goto next_exit;
      }

      /* Set zSql to the SQL to pull the list of tables from the 
      ** sqlite_master (or sqlite_temp_master) table of the database
      ** identified by the row pointed to by the SQL statement pCur->pDbList
      ** (iterating through a "PRAGMA database_list;" statement).
      */
      if( sqlite3_column_int(pCur->pDbList, 0)==1 ){
        zSql = sqlite3_mprintf(
            "SELECT name FROM sqlite_temp_master WHERE type='table'"
        );
      }else{

** allowed in an identifier.  For 7-bit characters, 
** sqlite3IsIdChar[X] must be 1.
**
** For EBCDIC, the rules are more complex but have the same
** end result.
**
** Ticket #1066.  the SQL standard does not allow '$' in the
** middle of identifiers.  But many SQL implementations do. 
** SQLite will allow '$' in identifiers for compatibility.
** But the feature is undocumented.
*/
#ifdef SQLITE_ASCII
#define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
#endif
#ifdef SQLITE_EBCDIC

  if( db->nVdbeActive==0 ){
    db->u1.isInterrupted = 0;
  }
  pParse->rc = SQLITE_OK;
  pParse->zTail = zSql;
  i = 0;
  assert( pzErrMsg!=0 );
  pEngine = sqlite3ParserAlloc(sqlite3Malloc);
  if( pEngine==0 ){
    db->mallocFailed = 1;
    return SQLITE_NOMEM;
  }
  assert( pParse->pNewTable==0 );
  assert( pParse->pNewTrigger==0 );
  assert( pParse->nVar==0 );

  /* A long-standing parser bug is that this syntax was allowed:
  **
  **    CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
  **                                                 ^^^^^^^^
  **
  ** To maintain backwards compatibility, ignore the database
  ** name on pTableName if we are reparsing out of SQLITE_MASTER.
  */
  if( db->init.busy && iDb!=1 ){
    sqlite3DbFree(db, pTableName->a[0].zDatabase);
    pTableName->a[0].zDatabase = 0;
  }

  /* If the trigger name was unqualified, and the table is a temp table,

  /* Start the view context. */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

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

    }
    if( chngRowid==0 && pPk==0 ){
      sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
    }
  }

  /* Populate the array of registers beginning at regNew with the new
  ** row data. This array is used to check constants, create the new
  ** table and index records, and as the values for any new.* references
  ** made by triggers.
  **
  ** If there are one or more BEFORE triggers, then do not populate the
  ** registers associated with columns that are (a) not modified by
  ** this UPDATE statement and (b) not accessed by new.* references. The
  ** values for registers not modified by the UPDATE must be reloaded from 

  sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
  sqlite3SrcListDelete(db, pTabList);
  sqlite3ExprListDelete(db, pChanges);
  sqlite3ExprDelete(db, pWhere);
  return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation).  */
#ifdef isView
 #undef isView
#endif
#ifdef pTrigger
 #undef pTrigger
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Generate code for an UPDATE of a virtual table.
**
** The strategy is that we create an ephemeral table that contains
** for each row to be changed:
**
**   (A)  The original rowid of that row.
**   (B)  The revised rowid for the row. (note1)
**   (C)  The content of every column in the row.
**
** Then we loop over this ephemeral table and for each row in
** the ephemeral table call VUpdate.
**
** When finished, drop the ephemeral table.
**
** (note1) Actually, if we know in advance that (A) is always the same
** as (B) we only store (A), then duplicate (A) when pulling
** it out of the ephemeral table before calling VUpdate.
*/

** is added to the dequoted string.
**
** The return value is -1 if no dequoting occurs or the length of the
** dequoted string, exclusive of the zero terminator, if dequoting does
** occur.
**
** 2002-Feb-14: This routine is extended to remove MS-Access style
** brackets from around identifiers.  For example:  "[a-b-c]" becomes
** "a-b-c".
*/
int sqlite3Dequote(char *z){
  char quote;
  int i, j;
  if( z==0 ) return -1;
  quote = z[0];

**        original database.
**
** The transient database requires temporary disk space approximately
** equal to the size of the original database.  The copy operation of
** step (3) requires additional temporary disk space approximately equal
** to the size of the original database for the rollback journal.
** Hence, temporary disk space that is approximately 2x the size of the
** original database is required.  Every page of the database is written
** approximately 3 times:  Once for step (2) and twice for step (3).
** Two writes per page are required in step (3) because the original
** database content must be written into the rollback journal prior to
** overwriting the database with the vacuumed content.
**
** Only 1x temporary space and only 1x writes would be required if
** the copy of step (3) were replace by deleting the original database

  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
  **
  ** Data(0) is taken from register P1.  Data(1) comes from register P1+1
  ** and so forth.
  **
  ** Each type field is a varint representing the serial type of the 
  ** corresponding data element (see sqlite3VdbeSerialType()). The
  ** hdr-size field is also a varint which is the offset from the beginning
  ** of the record to data0.
  */
  nData = 0;         /* Number of bytes of data space */

  pC->nullRow = 0;
#ifdef SQLITE_DEBUG
  pC->seekOp = pOp->opcode;
#endif
  if( pC->isTable ){
    /* The input value in P3 might be of any type: integer, real, string,
    ** blob, or NULL.  But it needs to be an integer before we can do
    ** the seek, so convert it. */
    pIn3 = &aMem[pOp->p3];
    if( (pIn3->flags & (MEM_Int|MEM_Real))==0 ){
      applyNumericAffinity(pIn3, 0);
    }
    iKey = sqlite3VdbeIntValue(pIn3);
    pC->rowidIsValid = 0;

** is for use inside assert() statements only.
*/
#ifdef SQLITE_DEBUG
#define memIsValid(M)  ((M)->flags & MEM_Undefined)==0
#endif

/*
** Each auxiliary data pointer stored by a user defined function 
** implementation calling sqlite3_set_auxdata() is stored in an instance
** of this structure. All such structures associated with a single VM
** are stored in a linked list headed at Vdbe.pAuxData. All are destroyed
** when the VM is halted (if not before).
*/
struct AuxData {
  int iOp;                        /* Instruction number of OP_Function opcode */
  int iArg;                       /* Index of function argument. */
  void *pAux;                     /* Aux data pointer */
  void (*xDelete)(void *);        /* Destructor for the aux data */
  AuxData *pNext;                 /* Next element in list */
};

/*
** The "context" argument for an installable function.  A pointer to an
** instance of this structure is the first argument to the routines used
** implement the SQL functions.
**
** There is a typedef for this structure in sqlite.h.  So all routines,
** even the public interface to SQLite, can use a pointer to this structure.
** But this file is the only place where the internal details of this
** structure are known.

  return aType[pVal->flags&MEM_AffMask];
}

/**************************** sqlite3_result_  *******************************
** The following routines are used by user-defined functions to specify
** the function result.
**
** The setStrOrError() function calls sqlite3VdbeMemSetStr() to store the
** result as a string or blob but if the string or blob is too large, it
** then sets the error code to SQLITE_TOOBIG
**
** The invokeValueDestructor(P,X) routine invokes destructor function X()
** on value P is not going to be used and need to be destroyed.
*/
static void setResultStrOrError(
  sqlite3_context *pCtx,  /* Function context */
  const char *z,          /* String pointer */
  int n,                  /* Bytes in string, or negative */
  u8 enc,                 /* Encoding of z.  0 for BLOBs */
  void (*xDel)(void*)     /* Destructor function */
){
  if( sqlite3VdbeMemSetStr(pCtx->pOut, z, n, enc, xDel)==SQLITE_TOOBIG ){
    sqlite3_result_error_toobig(pCtx);
  }
}
static int invokeValueDestructor(
  const void *p,             /* Value to destroy */
  void (*xDel)(void*),       /* The destructor */
  sqlite3_context *pCtx      /* Set a SQLITE_TOOBIG error if no NULL */
){
  assert( xDel!=SQLITE_DYNAMIC );
  if( xDel==0 ){
    /* noop */
  }else if( xDel==SQLITE_TRANSIENT ){
    /* noop */
  }else{
    xDel((void*)p);
  }
  if( pCtx ) sqlite3_result_error_toobig(pCtx);
  return SQLITE_TOOBIG;
}
void sqlite3_result_blob(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)
){
  assert( n>=0 );
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  setResultStrOrError(pCtx, z, n, 0, xDel);
}
void sqlite3_result_blob64(
  sqlite3_context *pCtx, 
  const void *z, 
  sqlite3_uint64 n,
  void (*xDel)(void *)
){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  assert( xDel!=SQLITE_DYNAMIC );
  if( n>0x7fffffff ){
    (void)invokeValueDestructor(z, xDel, pCtx);
  }else{
    setResultStrOrError(pCtx, z, (int)n, 0, xDel);
  }
}
void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  sqlite3VdbeMemSetDouble(pCtx->pOut, rVal);
}
void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );

  sqlite3_context *pCtx, 
  const char *z, 
  int n,
  void (*xDel)(void *)
){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  setResultStrOrError(pCtx, z, n, SQLITE_UTF8, xDel);
}
void sqlite3_result_text64(
  sqlite3_context *pCtx, 
  const char *z, 
  sqlite3_uint64 n,
  void (*xDel)(void *),
  unsigned char enc
){
  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  assert( xDel!=SQLITE_DYNAMIC );
  if( n>0x7fffffff ){
    (void)invokeValueDestructor(z, xDel, pCtx);
  }else{
    setResultStrOrError(pCtx, z, (int)n, enc, xDel);
  }
}
#ifndef SQLITE_OMIT_UTF16
void sqlite3_result_text16(
  sqlite3_context *pCtx, 
  const void *z, 
  int n, 
  void (*xDel)(void *)

    return createAggContext(p, nByte);
  }else{
    return (void*)p->pMem->z;
  }
}

/*
** Return the auxiliary data pointer, if any, for the iArg'th argument to
** the user-function defined by pCtx.
*/
void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
  AuxData *pAuxData;

  assert( sqlite3_mutex_held(pCtx->pOut->db->mutex) );
  for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
  }

  return (pAuxData ? pAuxData->pAux : 0);
}

/*
** Set the auxiliary data pointer and delete function, for the iArg'th
** argument to the user-function defined by pCtx. Any previous value is
** deleted by calling the delete function specified when it was set.
*/
void sqlite3_set_auxdata(
  sqlite3_context *pCtx, 
  int iArg, 
  void *pAux, 

  if( xDelete ){
    xDelete(pAux);
  }
}

#ifndef SQLITE_OMIT_DEPRECATED
/*
** Return the number of times the Step function of an aggregate has been 
** called.
**
** This function is deprecated.  Do not use it for new code.  It is
** provide only to avoid breaking legacy code.  New aggregate function
** implementations should keep their own counts within their aggregate
** context.
*/

#endif /* SQLITE_OMIT_UTF16 */
#endif /* SQLITE_OMIT_DECLTYPE */

#ifdef SQLITE_ENABLE_COLUMN_METADATA
/*
** Return the name of the database from which a result column derives.
** NULL is returned if the result column is an expression or constant or
** anything else which is not an unambiguous reference to a database column.
*/
const char *sqlite3_column_database_name(sqlite3_stmt *pStmt, int N){
  return columnName(
      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_DATABASE);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_column_database_name16(sqlite3_stmt *pStmt, int N){
  return columnName(
      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_DATABASE);
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Return the name of the table from which a result column derives.
** NULL is returned if the result column is an expression or constant or
** anything else which is not an unambiguous reference to a database column.
*/
const char *sqlite3_column_table_name(sqlite3_stmt *pStmt, int N){
  return columnName(
      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_TABLE);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_column_table_name16(sqlite3_stmt *pStmt, int N){
  return columnName(
      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text16, COLNAME_TABLE);
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Return the name of the table column from which a result column derives.
** NULL is returned if the result column is an expression or constant or
** anything else which is not an unambiguous reference to a database column.
*/
const char *sqlite3_column_origin_name(sqlite3_stmt *pStmt, int N){
  return columnName(
      pStmt, N, (const void*(*)(Mem*))sqlite3_value_text, COLNAME_COLUMN);
}
#ifndef SQLITE_OMIT_UTF16
const void *sqlite3_column_origin_name16(sqlite3_stmt *pStmt, int N){

  sqlite3_stmt *pStmt, 
  int i, 
  const void *zData, 
  int nData, 
  void (*xDel)(void*)
){
  return bindText(pStmt, i, zData, nData, xDel, 0);
}
int sqlite3_bind_blob64(
  sqlite3_stmt *pStmt, 
  int i, 
  const void *zData, 
  sqlite3_uint64 nData, 
  void (*xDel)(void*)
){
  assert( xDel!=SQLITE_DYNAMIC );
  if( nData>0x7fffffff ){
    return invokeValueDestructor(zData, xDel, 0);
  }else{
    return bindText(pStmt, i, zData, nData, xDel, 0);
  }
}
int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
  rc = vdbeUnbind(p, i);
  if( rc==SQLITE_OK ){
    sqlite3VdbeMemSetDouble(&p->aVar[i-1], rValue);

  sqlite3_stmt *pStmt, 
  int i, 
  const char *zData, 
  int nData, 
  void (*xDel)(void*)
){
  return bindText(pStmt, i, zData, nData, xDel, SQLITE_UTF8);
}
int sqlite3_bind_text64( 
  sqlite3_stmt *pStmt, 
  int i, 
  const char *zData, 
  sqlite3_uint64 nData, 
  void (*xDel)(void*),
  unsigned char enc
){
  assert( xDel!=SQLITE_DYNAMIC );
  if( nData>0x7fffffff ){
    return invokeValueDestructor(zData, xDel, 0);
  }else{
    if( enc==SQLITE_UTF16 ) enc = SQLITE_UTF16NATIVE;
    return bindText(pStmt, i, zData, nData, xDel, enc);
  }
}
#ifndef SQLITE_OMIT_UTF16
int sqlite3_bind_text16(
  sqlite3_stmt *pStmt, 
  int i, 
  const void *zData, 
  int nData, 

}

#ifndef SQLITE_OMIT_DEPRECATED
/*
** Deprecated external interface.  Internal/core SQLite code
** should call sqlite3TransferBindings.
**
** It is misuse to call this routine with statements from different
** database connections.  But as this is a deprecated interface, we
** will not bother to check for that condition.
**
** If the two statements contain a different number of bindings, then
** an SQLITE_ERROR is returned.  Nothing else can go wrong, so otherwise
** SQLITE_OK is returned.
*/

** Return the opcode for a given address.  If the address is -1, then
** return the most recently inserted opcode.
**
** If a memory allocation error has occurred prior to the calling of this
** routine, then a pointer to a dummy VdbeOp will be returned.  That opcode
** is readable but not writable, though it is cast to a writable value.
** The return of a dummy opcode allows the call to continue functioning
** after an OOM fault without having to check to see if the return from 
** this routine is a valid pointer.  But because the dummy.opcode is 0,
** dummy will never be written to.  This is verified by code inspection and
** by running with Valgrind.
*/
VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
  /* C89 specifies that the constant "dummy" will be initialized to all
  ** zeros, which is correct.  MSVC generates a warning, nevertheless. */

/*
** Prepare a virtual machine for execution for the first time after
** creating the virtual machine.  This involves things such
** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqlite3VdbeExec().  
**
** This function may be called exactly once on each virtual machine.
** After this routine is called the VM has been "packaged" and is ready
** to run.  After this routine is called, further calls to 
** sqlite3VdbeAddOp() functions are prohibited.  This routine disconnects
** the Vdbe from the Parse object that helped generate it so that the
** the Vdbe becomes an independent entity and the Parse object can be
** destroyed.
**
** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back
** to its initial state after it has been run.

    if( rc==SQLITE_OK ){
      sqlite3VtabCommit(db);
    }
  }

  /* The complex case - There is a multi-file write-transaction active.
  ** This requires a master journal file to ensure the transaction is
  ** committed atomically.
  */
#ifndef SQLITE_OMIT_DISKIO
  else{
    sqlite3_vfs *pVfs = db->pVfs;
    int needSync = 0;
    char *zMaster = 0;   /* File-name for the master journal */
    char const *zMainFile = sqlite3BtreeGetFilename(db->aDb[0].pBt);

** function invoked by the OP_Function opcode at instruction iOp of 
** VM pVdbe, and only then if:
**
**    * the associated function parameter is the 32nd or later (counting
**      from left to right), or
**
**    * the corresponding bit in argument mask is clear (where the first
**      function parameter corresponds to bit 0 etc.).
*/
void sqlite3VdbeDeleteAuxData(Vdbe *pVdbe, int iOp, int mask){
  AuxData **pp = &pVdbe->pAuxData;
  while( *pp ){
    AuxData *pAux = *pp;
    if( (iOp<0)
     || (pAux->iOp==iOp && (pAux->iArg>31 || !(mask & MASKBIT32(pAux->iArg))))

  return SQLITE_OK;
}

/*
** Something has moved cursor "p" out of place.  Maybe the row it was
** pointed to was deleted out from under it.  Or maybe the btree was
** rebalanced.  Whatever the cause, try to restore "p" to the place it
** is supposed to be pointing.  If the row was deleted out from under the
** cursor, set the cursor to point to a NULL row.
*/
static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
  int isDifferentRow, rc;
  assert( p->pCursor!=0 );
  assert( sqlite3BtreeCursorHasMoved(p->pCursor) );
  rc = sqlite3BtreeCursorRestore(p->pCursor, &isDifferentRow);

  /* No memory allocation is ever used on mem1.  Prove this using
  ** the following assert().  If the assert() fails, it indicates a
  ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).
  */
  assert( mem1.zMalloc==0 );

  /* rc==0 here means that one of the keys ran out of fields and
  ** all the fields up to that point were equal. Return the default_rc
  ** value.  */
  rc = pPKey2->default_rc;

debugCompareEnd:
  if( desiredResult==0 && rc==0 ) return 1;
  if( desiredResult<0 && rc<0 ) return 1;
  if( desiredResult>0 && rc>0 ) return 1;

}

/*
** This function compares the two table rows or index records
** specified by {nKey1, pKey1} and pPKey2.  It returns a negative, zero
** or positive integer if key1 is less than, equal to or 
** greater than key2.  The {nKey1, pKey1} key must be a blob
** created by the OP_MakeRecord opcode of the VDBE.  The pPKey2
** key must be a parsed key such as obtained from
** sqlite3VdbeParseRecord.
**
** If argument bSkip is non-zero, it is assumed that the caller has already
** determined that the first fields of the keys are equal.
**
** Key1 and Key2 do not have to contain the same number of fields. If all 

  /* No memory allocation is ever used on mem1.  Prove this using
  ** the following assert().  If the assert() fails, it indicates a
  ** memory leak and a need to call sqlite3VdbeMemRelease(&mem1).  */
  assert( mem1.zMalloc==0 );

  /* rc==0 here means that one or both of the keys ran out of fields and
  ** all the fields up to that point were equal. Return the default_rc
  ** value.  */
  assert( CORRUPT_DB 
       || vdbeRecordCompareDebug(nKey1, pKey1, pPKey2, pPKey2->default_rc) 
       || pKeyInfo->db->mallocFailed
  );
  return pPKey2->default_rc;
}

  assert( (p->flags & MEM_Dyn)!=0 || p->xDel==0 );

  /* If p holds a string or blob, the Mem.z must point to exactly
  ** one of the following:
  **
  **   (1) Memory in Mem.zMalloc and managed by the Mem object
  **   (2) Memory to be freed using Mem.xDel
  **   (3) An ephemeral string or blob
  **   (4) A static string or blob
  */
  if( (p->flags & (MEM_Str|MEM_Blob)) && p->z!=0 ){
    assert( 
      ((p->z==p->zMalloc)? 1 : 0) +
      ((p->flags&MEM_Dyn)!=0 ? 1 : 0) +
      ((p->flags&MEM_Ephem)!=0 ? 1 : 0) +

** Existing representations MEM_Int and MEM_Real are invalidated if
** bForce is true but are retained if bForce is false.
**
** A MEM_Null value will never be passed to this function. This function is
** used for converting values to text for returning to the user (i.e. via
** sqlite3_value_text()), or for ensuring that values to be used as btree
** keys are strings. In the former case a NULL pointer is returned the
** user and the latter is an internal programming error.
*/
int sqlite3VdbeMemStringify(Mem *pMem, u8 enc, u8 bForce){
  int fg = pMem->flags;
  const int nByte = 32;

  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( !(fg&MEM_Zero) );

/*
** Return some kind of integer value which is the best we can do
** at representing the value that *pMem describes as an integer.
** If pMem is an integer, then the value is exact.  If pMem is
** a floating-point then the value returned is the integer part.
** If pMem is a string or blob, then we make an attempt to convert
** it into an integer and return that.  If pMem represents an
** an SQL-NULL value, return 0.
**
** If pMem represents a string value, its encoding might be changed.
*/
i64 sqlite3VdbeIntValue(Mem *pMem){
  int flags;
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

    return n>p->db->aLimit[SQLITE_LIMIT_LENGTH];
  }
  return 0; 
}

#ifdef SQLITE_DEBUG
/*
** This routine prepares a memory cell for modification by breaking
** its link to a shallow copy and by marking any current shallow
** copies of this cell as invalid.
**
** This is used for testing and debugging only - to make sure shallow
** copies are not misused.
*/
void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){

               );
  pReader->pIncr->pTask->bDone = 1;
  return pRet;
}

/*
** Use a background thread to invoke vdbePmaReaderIncrMergeInit(INCRINIT_TASK) 
** on the PmaReader object passed as the first argument.
**
** This call will initialize the various fields of the pReadr->pIncr 
** structure and, if it is a multi-threaded IncrMerger, launch a 
** background thread to populate aFile[1].
*/
static int vdbePmaReaderBgIncrInit(PmaReader *pReadr){
  void *pCtx = (void*)pReadr;

**
** The calling function is responsible for making sure the memory returned
** is eventually freed.
**
** ALGORITHM:  Scan the input string looking for host parameters in any of
** these forms:  ?, ?N, $A, @A, :A.  Take care to avoid text within
** string literals, quoted identifier names, and comments.  For text forms,
** the host parameter index is found by scanning the prepared
** statement for the corresponding OP_Variable opcode.  Once the host
** parameter index is known, locate the value in p->aVar[].  Then render
** the value as a literal in place of the host parameter name.
*/
char *sqlite3VdbeExpandSql(
  Vdbe *p,                 /* The prepared statement being evaluated */
  const char *zRawSql      /* Raw text of the SQL statement */

  return (volatile WalIndexHdr*)pWal->apWiData[0];
}

/*
** The argument to this macro must be of type u32. On a little-endian
** architecture, it returns the u32 value that results from interpreting
** the 4 bytes as a big-endian value. On a big-endian architecture, it
** returns the value that would be produced by interpreting the 4 bytes
** of the input value as a little-endian integer.
*/
#define BYTESWAP32(x) ( \
    (((x)&0x000000FF)<<24) + (((x)&0x0000FF00)<<8)  \
  + (((x)&0x00FF0000)>>8)  + (((x)&0xFF000000)>>24) \
)

    int idx;                      /* Value to write to hash-table slot */
    int nCollide;                 /* Number of hash collisions */

    idx = iFrame - iZero;
    assert( idx <= HASHTABLE_NSLOT/2 + 1 );
    
    /* If this is the first entry to be added to this hash-table, zero the
    ** entire hash table and aPgno[] array before proceeding. 
    */
    if( idx==1 ){
      int nByte = (int)((u8 *)&aHash[HASHTABLE_NSLOT] - (u8 *)&aPgno[1]);
      memset((void*)&aPgno[1], 0, nByte);
    }

    /* If the entry in aPgno[] is already set, then the previous writer

**
** Fsync is also called on the database file if (and only if) the entire
** WAL content is copied into the database file.  This second fsync makes
** it safe to delete the WAL since the new content will persist in the
** database file.
**
** This routine uses and updates the nBackfill field of the wal-index header.
** This is the only routine that will increase the value of nBackfill.  
** (A WAL reset or recovery will revert nBackfill to zero, but not increase
** its value.)
**
** The caller must be holding sufficient locks to ensure that no other
** checkpoint is running (in any other thread or process) at the same
** time.
*/

/*
** Read the wal-index header from the wal-index and into pWal->hdr.
** If the wal-header appears to be corrupt, try to reconstruct the
** wal-index from the WAL before returning.
**
** Set *pChanged to 1 if the wal-index header value in pWal->hdr is
** changed by this operation.  If pWal->hdr is unchanged, set *pChanged
** to 0.
**
** If the wal-index header is successfully read, return SQLITE_OK. 
** Otherwise an SQLite error code.
*/
static int walIndexReadHdr(Wal *pWal, int *pChanged){
  int rc;                         /* Return code */

    walShmBarrier(pWal);
    if( rc==SQLITE_OK ){
      if( memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr)) ){
        /* It is not safe to allow the reader to continue here if frames
        ** may have been appended to the log before READ_LOCK(0) was obtained.
        ** When holding READ_LOCK(0), the reader ignores the entire log file,
        ** which implies that the database file contains a trustworthy
        ** snapshot. Since holding READ_LOCK(0) prevents a checkpoint from
        ** happening, this is usually correct.
        **
        ** However, if frames have been appended to the log (or if the log 
        ** is wrapped and written for that matter) before the READ_LOCK(0)
        ** is obtained, that is not necessarily true. A checkpointer may
        ** have started to backfill the appended frames but crashed before
        ** it finished. Leaving a corrupt image in the database file.

  }

  /* If this is the end of a transaction, then we might need to pad
  ** the transaction and/or sync the WAL file.
  **
  ** Padding and syncing only occur if this set of frames complete a
  ** transaction and if PRAGMA synchronous=FULL.  If synchronous==NORMAL
  ** or synchronous==OFF, then no padding or syncing are needed.
  **
  ** If SQLITE_IOCAP_POWERSAFE_OVERWRITE is defined, then padding is not
  ** needed and only the sync is done.  If padding is needed, then the
  ** final frame is repeated (with its commit mark) until the next sector
  ** boundary is crossed.  Only the part of the WAL prior to the last
  ** sector boundary is synced; the part of the last frame that extends
  ** past the sector boundary is written after the sync.

#include "sqliteInt.h"
#include <stdlib.h>
#include <string.h>


/*
** Walk an expression tree.  Invoke the callback once for each node
** of the expression, while descending.  (In other words, the callback
** is invoked before visiting children.)
**
** The return value from the callback should be one of the WRC_*
** constants to specify how to proceed with the walk.
**
**    WRC_Continue      Continue descending down the tree.
**

        Vdbe *v = pParse->pVdbe;
        sqlite3VdbeSetVarmask(v, pRight->iColumn);
        if( *pisComplete && pRight->u.zToken[1] ){
          /* If the rhs of the LIKE expression is a variable, and the current
          ** value of the variable means there is no need to invoke the LIKE
          ** function, then no OP_Variable will be added to the program.
          ** This causes problems for the sqlite3_bind_parameter_name()
          ** API. To work around them, add a dummy OP_Variable here.
          */ 
          int r1 = sqlite3GetTempReg(pParse);
          sqlite3ExprCodeTarget(pParse, pRight, r1);
          sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
          sqlite3ReleaseTempReg(pParse, r1);
        }
      }

** From another point of view, "indexable" means that the subterm could
** potentially be used with an index if an appropriate index exists.
** This analysis does not consider whether or not the index exists; that
** is decided elsewhere.  This analysis only looks at whether subterms
** appropriate for indexing exist.
**
** All examples A through E above satisfy case 2.  But if a term
** also satisfies case 1 (such as B) we know that the optimizer will
** always prefer case 1, so in that case we pretend that case 2 is not
** satisfied.
**
** It might be the case that multiple tables are indexable.  For example,
** (E) above is indexable on tables P, Q, and R.
**
** Terms that satisfy case 2 are candidates for lookup by using

          /* This is the 2-bit case and we are on the second iteration and
          ** current term is from the first iteration.  So skip this term. */
          assert( j==1 );
          continue;
        }
        if( (chngToIN & getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){
          /* This term must be of the form t1.a==t2.b where t2 is in the
          ** chngToIN set but t1 is not.  This term will be either preceded
          ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 
          ** and use its inversion. */
          testcase( pOrTerm->wtFlags & TERM_COPIED );
          testcase( pOrTerm->wtFlags & TERM_VIRTUAL );
          assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );
          continue;
        }

  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
  ** an index for tables to the left of the join.
  */
  pTerm->prereqRight |= extraRight;
}

/*
** This function searches pList for an entry that matches the iCol-th column
** of index pIdx.
**
** If such an expression is found, its index in pList->a[] is returned. If
** no expression is found, -1 is returned.
*/
static int findIndexCol(
  Parse *pParse,                  /* Parse context */

**
** then nEq is set to 0.
**
** When this function is called, *pnOut is set to the sqlite3LogEst() of the
** number of rows that the index scan is expected to visit without 
** considering the range constraints. If nEq is 0, this is the number of 
** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
** to account for the range constraints pLower and pUpper.
** 
** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
** used, a single range inequality reduces the search space by a factor of 4. 
** and a pair of constraints (x>? AND x<?) reduces the expected number of
** rows visited by a factor of 64.
*/
static int whereRangeScanEst(

    **       A: <loop body>                 # Return data, whatever.
    **
    **          Return     2                # Jump back to the Gosub
    **
    **       B: <after the loop>
    **
    ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
    ** use an ephemeral index instead of a RowSet to record the primary
    ** keys of the rows we have already seen.
    **
    */
    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
    Index *pCov = 0;             /* Potential covering index (or NULL) */
    int iCovCur = pParse->nTab++;  /* Cursor used for index scans (if any) */

        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
      }
    }else{
      pOrTab = pWInfo->pTabList;
    }

    /* Initialize the rowset register to contain NULL. An SQL NULL is 
    ** equivalent to an empty rowset.  Or, create an ephemeral index
    ** capable of holding primary keys in the case of a WITHOUT ROWID.
    **
    ** Also initialize regReturn to contain the address of the instruction 
    ** immediately following the OP_Return at the bottom of the loop. This
    ** is required in a few obscure LEFT JOIN cases where control jumps
    ** over the top of the loop into the body of it. In this case the 
    ** correct response for the end-of-loop code (the OP_Return) is to 

** WHERE clause that reference the loop but which are not used by an
** index.
**
** In the current implementation, the first extra WHERE clause term reduces
** the number of output rows by a factor of 10 and each additional term
** reduces the number of output rows by sqrt(2).
*/
static void whereLoopOutputAdjust(
  WhereClause *pWC,      /* The WHERE clause */
  WhereLoop *pLoop,      /* The loop to adjust downward */
  LogEst nRow            /* Number of rows in the entire table */
){
  WhereTerm *pTerm, *pX;
  Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
  int i, j;
  int nEq = 0;    /* Number of = constraints not within likely()/unlikely() */



  for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
    if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
    if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
    if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
    for(j=pLoop->nLTerm-1; j>=0; j--){
      pX = pLoop->aLTerm[j];
      if( pX==0 ) continue;
      if( pX==pTerm ) break;
      if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
    }
    if( j<0 ){
      if( pTerm->truthProb<=0 ){
        pLoop->nOut += pTerm->truthProb;
      }else{
        pLoop->nOut--;
        if( pTerm->eOperator&WO_EQ ) nEq++;
      }
    }
  }
  /* TUNING:  If there is at least one equality constraint in the WHERE
  ** clause that does not have a likelihood() explicitly assigned to it
  ** then do not let the estimated number of output rows exceed half 
  ** the number of rows in the table. */
  if( nEq && pLoop->nOut>nRow-10 ){
    pLoop->nOut = nRow - 10;
  }
}

/*
** Adjust the cost C by the costMult facter T.  This only occurs if
** compiled with -DSQLITE_ENABLE_COSTMULT
*/

  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
  u16 saved_nSkip;                /* Original value of pNew->u.btree.nSkip */
  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
  LogEst saved_nOut;              /* Original value of pNew->nOut */
  int iCol;                       /* Index of the column in the table */
  int rc = SQLITE_OK;             /* Return code */
  LogEst rSize;                   /* Number of rows in the table */
  LogEst rLogSize;                /* Logarithm of table size */
  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */

  pNew = pBuilder->pNew;
  if( db->mallocFailed ) return SQLITE_NOMEM;

  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );

  saved_nEq = pNew->u.btree.nEq;
  saved_nSkip = pNew->u.btree.nSkip;
  saved_nLTerm = pNew->nLTerm;
  saved_wsFlags = pNew->wsFlags;
  saved_prereq = pNew->prereq;
  saved_nOut = pNew->nOut;
  pNew->rSetup = 0;
  rSize = pProbe->aiRowLogEst[0];
  rLogSize = estLog(rSize);

  /* Consider using a skip-scan if there are no WHERE clause constraints
  ** available for the left-most terms of the index, and if the average
  ** number of repeats in the left-most terms is at least 18. 
  **
  ** The magic number 18 is selected on the basis that scanning 17 rows
  ** is almost always quicker than an index seek (even though if the index

      pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
    }
    ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);

    nOutUnadjusted = pNew->nOut;
    pNew->rRun += nInMul + nIn;
    pNew->nOut += nInMul + nIn;
    whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);
    rc = whereLoopInsert(pBuilder, pNew);

    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
      pNew->nOut = saved_nOut;
    }else{
      pNew->nOut = nOutUnadjusted;
    }

        /* TUNING: One-time cost for computing the automatic index is
        ** approximately 7*N*log2(N) where N is the number of rows in
        ** the table being indexed. */
        pNew->rSetup = rLogSize + rSize + 28;  assert( 28==sqlite3LogEst(7) );
        ApplyCostMultiplier(pNew->rSetup, pTab->costMult);
        /* TUNING: Each index lookup yields 20 rows in the table.  This
        ** is more than the usual guess of 10 rows, since we have no way
        ** of knowing how selective the index will ultimately be.  It would
        ** not be unreasonable to make this value much larger. */
        pNew->nOut = 43;  assert( 43==sqlite3LogEst(20) );
        pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);
        pNew->wsFlags = WHERE_AUTO_INDEX;
        pNew->prereq = mExtra | pTerm->prereqRight;
        rc = whereLoopInsert(pBuilder, pNew);
      }

      pNew->wsFlags = WHERE_IPK;

      /* Full table scan */
      pNew->iSortIdx = b ? iSortIdx : 0;
      /* TUNING: Cost of full table scan is (N*3.0). */
      pNew->rRun = rSize + 16;
      ApplyCostMultiplier(pNew->rRun, pTab->costMult);
      whereLoopOutputAdjust(pWC, pNew, rSize);
      rc = whereLoopInsert(pBuilder, pNew);
      pNew->nOut = rSize;
      if( rc ) break;
    }else{
      Bitmask m;
      if( pProbe->isCovering ){
        pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;

        ** index and table rows. If this is a non-covering index scan,
        ** also add the cost of visiting table rows (N*3.0).  */
        pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
        if( m!=0 ){
          pNew->rRun = sqlite3LogEstAdd(pNew->rRun, rSize+16);
        }
        ApplyCostMultiplier(pNew->rRun, pTab->costMult);
        whereLoopOutputAdjust(pWC, pNew, rSize);
        rc = whereLoopInsert(pBuilder, pNew);
        pNew->nOut = rSize;
        if( rc ) break;
      }
    }

    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);

**   N==0:  No terms of the ORDER BY clause are satisfied
**   N<0:   Unknown yet how many terms of ORDER BY might be satisfied.   
**
** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
** strict.  With GROUP BY and DISTINCT the only requirement is that
** equivalent rows appear immediately adjacent to one another.  GROUP BY
** and DISTINCT do not require rows to appear in any particular order as long
** as equivalent rows are grouped together.  Thus for GROUP BY and DISTINCT
** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
** pOrderBy terms must be matched in strict left-to-right order.
*/
static i8 wherePathSatisfiesOrderBy(
  WhereInfo *pWInfo,    /* The WHERE clause */
  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
  WherePath *pPath,     /* The WherePath to check */

** Then a WherePath object is a path through the graph that visits some
** or all of the WhereLoop objects once.
**
** The "solver" works by creating the N best WherePath objects of length
** 1.  Then using those as a basis to compute the N best WherePath objects
** of length 2.  And so forth until the length of WherePaths equals the
** number of nodes in the FROM clause.  The best (lowest cost) WherePath
** at the end is the chosen query plan.
*/
struct WherePath {
  Bitmask maskLoop;     /* Bitmask of all WhereLoop objects in this path */
  Bitmask revLoop;      /* aLoop[]s that should be reversed for ORDER BY */
  LogEst nRow;          /* Estimated number of rows generated by this path */
  LogEst rCost;         /* Total cost of this path */
  LogEst rUnsorted;     /* Total cost of this path ignoring sorting costs */

    INSERT INTO t2 VALUES(1);
    SELECT
     (SELECT sum(value2==xyz) FROM t2)
    FROM
     (SELECT value1 as xyz, max(x1) AS pqr
        FROM t1
       GROUP BY id1);
    SELECT
     (SELECT sum(value2<>xyz) FROM t2)
    FROM
     (SELECT value1 as xyz, max(x1) AS pqr
        FROM t1
       GROUP BY id1);
  }
} {1 0}
do_test aggnested-3.3 {
  db eval {
    DROP TABLE IF EXISTS t1;
    DROP TABLE IF EXISTS t2;
    CREATE TABLE t1(id1, value1);
    INSERT INTO t1 VALUES(4469,2),(4469,1);
    CREATE TABLE t2 (value2);