SQLite Android Bindings

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.42.0.  By combining all the individual C code files into this
** single large file, the entire code can be compiled as a single translation
** unit.  This allows many compilers to do optimizations that would not be
** possible if the files were compiled separately.  Performance improvements
** of 5% or more are commonly seen when SQLite is compiled as a single
** translation unit.
**
** This file is all you need to compile SQLite.  To use SQLite in other

#endif /* defined(_MSC_VER) */

#if defined(_MSC_VER) && !defined(_WIN64)
#undef SQLITE_4_BYTE_ALIGNED_MALLOC
#define SQLITE_4_BYTE_ALIGNED_MALLOC
#endif /* defined(_MSC_VER) && !defined(_WIN64) */

#if !defined(HAVE_LOG2) && defined(_MSC_VER) && _MSC_VER<1800
#define HAVE_LOG2 0
#endif /* !defined(HAVE_LOG2) && defined(_MSC_VER) && _MSC_VER<1800 */

#endif /* SQLITE_MSVC_H */

/************** End of msvc.h ************************************************/
/************** Continuing where we left off in sqliteInt.h ******************/

/*
** Special setup for VxWorks

** been edited in any way since it was last checked in, then the last
** four hexadecimal digits of the hash may be modified.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.42.0"
#define SQLITE_VERSION_NUMBER 3042000
#define SQLITE_SOURCE_ID      "2023-05-16 12:36:15 831d0fb2836b71c9bc51067c49fee4b8f18047814f2ff22d817d25195cf350b0"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

** applications and so this routine is usually not necessary.  It is
** provided to support rare applications with unusual needs.
**
** <b>The sqlite3_config() interface is not threadsafe. The application
** must ensure that no other SQLite interfaces are invoked by other
** threads while sqlite3_config() is running.</b>
**








** The first argument to sqlite3_config() is an integer
** [configuration option] that determines
** what property of SQLite is to be configured.  Subsequent arguments
** vary depending on the [configuration option]
** in the first argument.
**
** For most configuration options, the sqlite3_config() interface
** may only be invoked prior to library initialization using
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
** The exceptional configuration options that may be invoked at any time
** are called "anytime configuration options".
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
** [sqlite3_shutdown()] with a first argument that is not an anytime
** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
** Note, however, that ^sqlite3_config() can be called as part of the
** implementation of an application-defined [sqlite3_os_init()].
**
** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
** ^If the option is unknown or SQLite is unable to set the option
** then this routine returns a non-zero [error code].
*/
SQLITE_API int sqlite3_config(int, ...);

/*
** CAPI3REF: Configuration Options
** KEYWORDS: {configuration option}
**
** These constants are the available integer configuration options that
** can be passed as the first argument to the [sqlite3_config()] interface.
**
** Most of the configuration options for sqlite3_config()
** will only work if invoked prior to [sqlite3_initialize()] or after
** [sqlite3_shutdown()].  The few exceptions to this rule are called
** "anytime configuration options".
** ^Calling [sqlite3_config()] with a first argument that is not an
** anytime configuration option in between calls to [sqlite3_initialize()] and
** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
**
** The set of anytime configuration options can change (by insertions
** and/or deletions) from one release of SQLite to the next.
** As of SQLite version 3.42.0, the complete set of anytime configuration
** options is:
** <ul>
** <li> SQLITE_CONFIG_LOG
** <li> SQLITE_CONFIG_PCACHE_HDRSZ
** </ul>
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
** should check the return code from [sqlite3_config()] to make sure that
** the call worked.  The [sqlite3_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.

** size can be adjusted up or down for individual databases using the
** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control].  If this
** configuration setting is never used, then the default maximum is determined
** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option.  If that
** compile-time option is not set, then the default maximum is 1073741824.
** </dl>
*/
#define SQLITE_CONFIG_SINGLETHREAD         1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD          2  /* nil */
#define SQLITE_CONFIG_SERIALIZED           3  /* nil */
#define SQLITE_CONFIG_MALLOC               4  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_GETMALLOC            5  /* sqlite3_mem_methods* */
#define SQLITE_CONFIG_SCRATCH              6  /* No longer used */
#define SQLITE_CONFIG_PAGECACHE            7  /* void*, int sz, int N */
#define SQLITE_CONFIG_HEAP                 8  /* void*, int nByte, int min */
#define SQLITE_CONFIG_MEMSTATUS            9  /* boolean */
#define SQLITE_CONFIG_MUTEX               10  /* sqlite3_mutex_methods* */
#define SQLITE_CONFIG_GETMUTEX            11  /* sqlite3_mutex_methods* */
/* previously SQLITE_CONFIG_CHUNKALLOC    12 which is now unused. */
#define SQLITE_CONFIG_LOOKASIDE           13  /* int int */
#define SQLITE_CONFIG_PCACHE              14  /* no-op */
#define SQLITE_CONFIG_GETPCACHE           15  /* no-op */
#define SQLITE_CONFIG_LOG                 16  /* xFunc, void* */
#define SQLITE_CONFIG_URI                 17  /* int */
#define SQLITE_CONFIG_PCACHE2             18  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_GETPCACHE2          19  /* sqlite3_pcache_methods2* */
#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20  /* int */
#define SQLITE_CONFIG_SQLLOG              21  /* xSqllog, void* */
#define SQLITE_CONFIG_MMAP_SIZE           22  /* sqlite3_int64, sqlite3_int64 */
#define SQLITE_CONFIG_WIN32_HEAPSIZE      23  /* int nByte */
#define SQLITE_CONFIG_PCACHE_HDRSZ        24  /* int *psz */
#define SQLITE_CONFIG_PMASZ               25  /* unsigned int szPma */
#define SQLITE_CONFIG_STMTJRNL_SPILL      26  /* int nByte */
#define SQLITE_CONFIG_SMALL_MALLOC        27  /* boolean */
#define SQLITE_CONFIG_SORTERREF_SIZE      28  /* int nByte */
#define SQLITE_CONFIG_MEMDB_MAXSIZE       29  /* sqlite3_int64 */

** behaves as it did prior to [version 3.24.0] (2018-06-04).  See the
** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
** additional information. This feature can also be turned on and off
** using the [PRAGMA legacy_alter_table] statement.
** </dd>
**
** [[SQLITE_DBCONFIG_DQS_DML]]
** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
** the legacy [double-quoted string literal] misfeature for DML statements
** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
** default value of this setting is determined by the [-DSQLITE_DQS]
** compile-time option.
** </dd>
**
** [[SQLITE_DBCONFIG_DQS_DDL]]
** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
** the legacy [double-quoted string literal] misfeature for DDL statements,
** such as CREATE TABLE and CREATE INDEX. The
** default value of this setting is determined by the [-DSQLITE_DQS]
** compile-time option.
** </dd>
**
** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
** assume that database schemas are untainted by malicious content.
** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
** takes additional defensive steps to protect the application from harm
** including:
** <ul>
** <li> Prohibit the use of SQL functions inside triggers, views,
** CHECK constraints, DEFAULT clauses, expression indexes,
** partial indexes, or generated columns
** unless those functions are tagged with [SQLITE_INNOCUOUS].
** <li> Prohibit the use of virtual tables inside of triggers or views
** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
** </ul>
** This setting defaults to "on" for legacy compatibility, however
** all applications are advised to turn it off if possible. This setting
** can also be controlled using the [PRAGMA trusted_schema] statement.
** </dd>
**
** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
** the legacy file format flag.  When activated, this flag causes all newly
** created database file to have a schema format version number (the 4-byte
** integer found at offset 44 into the database header) of 1.  This in turn
** means that the resulting database file will be readable and writable by
** any SQLite version back to 3.0.0 ([dateof:3.0.0]).  Without this setting,
** newly created databases are generally not understandable by SQLite versions
** prior to 3.3.0 ([dateof:3.3.0]).  As these words are written, there
** is now scarcely any need to generate database files that are compatible
** all the way back to version 3.0.0, and so this setting is of little
** practical use, but is provided so that SQLite can continue to claim the
** ability to generate new database files that are compatible with  version
** 3.0.0.
** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
** the [VACUUM] command will fail with an obscure error when attempting to
** process a table with generated columns and a descending index.  This is
** not considered a bug since SQLite versions 3.3.0 and earlier do not support
** either generated columns or decending indexes.
** </dd>
**
** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
** statistics. For statistics to be collected, the flag must be set on
** the database handle both when the SQL statement is prepared and when it
** is stepped. The flag is set (collection of statistics is enabled)
** by default.  This option takes two arguments: an integer and a pointer to
** an integer..  The first argument is 1, 0, or -1 to enable, disable, or
** leave unchanged the statement scanstatus option.  If the second argument
** is not NULL, then the value of the statement scanstatus setting after
** processing the first argument is written into the integer that the second
** argument points to.
** </dd>
**
** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
** in which tables and indexes are scanned so that the scans start at the end
** and work toward the beginning rather than starting at the beginning and
** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
** same as setting [PRAGMA reverse_unordered_selects].  This option takes
** two arguments which are an integer and a pointer to an integer.  The first
** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
** reverse scan order flag, respectively.  If the second argument is not NULL,
** then 0 or 1 is written into the integer that the second argument points to
** depending on if the reverse scan order flag is set after processing the
** first argument.
** </dd>
**
** </dl>
*/
#define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
#define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
#define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
#define SQLITE_DBCONFIG_DEFENSIVE             1010 /* int int* */
#define SQLITE_DBCONFIG_WRITABLE_SCHEMA       1011 /* int int* */
#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    1012 /* int int* */
#define SQLITE_DBCONFIG_DQS_DML               1013 /* int int* */
#define SQLITE_DBCONFIG_DQS_DDL               1014 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_VIEW           1015 /* int int* */
#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT    1016 /* int int* */
#define SQLITE_DBCONFIG_TRUSTED_SCHEMA        1017 /* int int* */
#define SQLITE_DBCONFIG_STMT_SCANSTATUS       1018 /* int int* */
#define SQLITE_DBCONFIG_REVERSE_SCANORDER     1019 /* int int* */
#define SQLITE_DBCONFIG_MAX                   1019 /* Largest DBCONFIG */

/*
** CAPI3REF: Enable Or Disable Extended Result Codes
** METHOD: sqlite3
**
** ^The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. ^The extended result

** requested from the operating system is returned.
**
** ^SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.  If the xSleep() method
** of the default VFS is not implemented correctly, or not implemented at
** all, then the behavior of sqlite3_sleep() may deviate from the description
** in the previous paragraphs.
**
** If a negative argument is passed to sqlite3_sleep() the results vary by
** VFS and operating system.  Some system treat a negative argument as an
** instruction to sleep forever.  Others understand it to mean do not sleep
** at all. ^In SQLite version 3.42.0 and later, a negative
** argument passed into sqlite3_sleep() is changed to zero before it is relayed
** down into the xSleep method of the VFS.
*/
SQLITE_API int sqlite3_sleep(int);

/*
** CAPI3REF: Name Of The Folder Holding Temporary Files
**
** ^(If this global variable is made to point to a string which is

** behavior.)^
**
** ^The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.   The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.
**
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
** then any of the four routines behaves as a no-op.
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);

** prohibits that virtual table from being used from within triggers and
** views.
** </dd>
**
** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
** <dd>Calls of the form
** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
** the [xConnect] or [xCreate] methods of a [virtual table] implementation
** identify that virtual table as being safe to use from within triggers
** and views.  Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
** virtual table can do no serious harm even if it is controlled by a
** malicious hacker.  Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
** flag unless absolutely necessary.
** </dd>
**
** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
** <dd>Calls of the form
** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
** the [xConnect] or [xCreate] methods of a [virtual table] implementation
** instruct the query planner to begin at least a read transaction on
** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
** virtual table is used.
** </dd>
** </dl>
*/
#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
#define SQLITE_VTAB_INNOCUOUS          2
#define SQLITE_VTAB_DIRECTONLY         3
#define SQLITE_VTAB_USES_ALL_SCHEMAS   4

/*
** CAPI3REF: Determine The Virtual Table Conflict Policy
**
** This function may only be called from within a call to the [xUpdate] method
** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],

** Session objects must be deleted before the database handle to which they
** are attached is closed. Refer to the documentation for
** [sqlite3session_create()] for details.
*/
SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);

/*
** CAPI3REF: Configure a Session Object
** METHOD: sqlite3_session
**
** This method is used to configure a session object after it has been
** created. At present the only valid values for the second parameter are
** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
**
*/
SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);

/*
** CAPI3REF: Options for sqlite3session_object_config
**
** The following values may passed as the the 2nd parameter to
** sqlite3session_object_config().
**
** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
**   This option is used to set, clear or query the flag that enables
**   the [sqlite3session_changeset_size()] API. Because it imposes some
**   computational overhead, this API is disabled by default. Argument
**   pArg must point to a value of type (int). If the value is initially
**   0, then the sqlite3session_changeset_size() API is disabled. If it
**   is greater than 0, then the same API is enabled. Or, if the initial
**   value is less than zero, no change is made. In all cases the (int)
**   variable is set to 1 if the sqlite3session_changeset_size() API is
**   enabled following the current call, or 0 otherwise.
**
**   It is an error (SQLITE_MISUSE) to attempt to modify this setting after
**   the first table has been attached to the session object.
**
** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
**   This option is used to set, clear or query the flag that enables
**   collection of data for tables with no explicit PRIMARY KEY.
**
**   Normally, tables with no explicit PRIMARY KEY are simply ignored
**   by the sessions module. However, if this flag is set, it behaves
**   as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
**   as their leftmost columns.
**
**   It is an error (SQLITE_MISUSE) to attempt to modify this setting after
**   the first table has been attached to the session object.
*/
#define SQLITE_SESSION_OBJCONFIG_SIZE  1
#define SQLITE_SESSION_OBJCONFIG_ROWID 2

/*
** CAPI3REF: Enable Or Disable A Session Object
** METHOD: sqlite3_session
**
** Enable or disable the recording of changes by a session object. When
** enabled, a session object records changes made to the database. When

**   caller has an open transaction or savepoint when apply_v2() is called,
**   it may revert the partially applied changeset by rolling it back.
**
** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
**   Invert the changeset before applying it. This is equivalent to inverting
**   a changeset using sqlite3changeset_invert() before applying it. It is
**   an error to specify this flag with a patchset.
**
** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
**   Do not invoke the conflict handler callback for any changes that
**   would not actually modify the database even if they were applied.
**   Specifically, this means that the conflict handler is not invoked
**   for:
**    <ul>
**    <li>a delete change if the row being deleted cannot be found,
**    <li>an update change if the modified fields are already set to
**        their new values in the conflicting row, or
**    <li>an insert change if all fields of the conflicting row match
**        the row being inserted.
**    </ul>
*/
#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT   0x0001
#define SQLITE_CHANGESETAPPLY_INVERT        0x0002
#define SQLITE_CHANGESETAPPLY_IGNORENOOP    0x0004

/*
** CAPI3REF: Constants Passed To The Conflict Handler
**
** Values that may be passed as the second argument to a conflict-handler.
**
** <dl>

#pragma warn -ccc /* Condition is always true or false */
#pragma warn -aus /* Assigned value is never used */
#pragma warn -csu /* Comparing signed and unsigned */
#pragma warn -spa /* Suspicious pointer arithmetic */
#endif

/*
** A few places in the code require atomic load/store of aligned
** integer values.
*/
#ifndef __has_extension
# define __has_extension(x) 0     /* compatibility with non-clang compilers */
#endif
#if GCC_VERSION>=4007000 || __has_extension(c_atomic)
# define SQLITE_ATOMIC_INTRINSICS 1
# define AtomicLoad(PTR)       __atomic_load_n((PTR),__ATOMIC_RELAXED)

# define SQLITE_PTR_TO_INT(X)  ((int)(((char*)X)-(char*)0))
#else                          /* Generates a warning - but it always works */
# define SQLITE_INT_TO_PTR(X)  ((void*)(X))
# define SQLITE_PTR_TO_INT(X)  ((int)(X))
#endif

/*
** Macros to hint to the compiler that a function should or should not be
** inlined.
*/
#if defined(__GNUC__)
#  define SQLITE_NOINLINE  __attribute__((noinline))
#  define SQLITE_INLINE    __attribute__((always_inline)) inline
#elif defined(_MSC_VER) && _MSC_VER>=1310
#  define SQLITE_NOINLINE  __declspec(noinline)
#  define SQLITE_INLINE    __forceinline
#else
#  define SQLITE_NOINLINE
#  define SQLITE_INLINE
#endif
#if defined(SQLITE_COVERAGE_TEST) || defined(__STRICT_ANSI__)
# undef SQLITE_INLINE
# define SQLITE_INLINE
#endif

/*
** Make sure that the compiler intrinsics we desire are enabled when
** compiling with an appropriate version of MSVC unless prevented by
** the SQLITE_DISABLE_INTRINSIC define.
*/

# define sqlite3VdbeScanStatusRange(a,b,c,d)
# define sqlite3VdbeScanStatusCounters(a,b,c,d)
#endif

#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
SQLITE_PRIVATE void sqlite3VdbePrintOp(FILE*, int, VdbeOp*);
#endif

#if defined(SQLITE_ENABLE_CURSOR_HINTS) && defined(SQLITE_DEBUG)
SQLITE_PRIVATE int sqlite3CursorRangeHintExprCheck(Walker *pWalker, Expr *pExpr);
#endif

#endif /* SQLITE_VDBE_H */

/************** End of vdbe.h ************************************************/
/************** Continuing where we left off in sqliteInt.h ******************/
/************** Include pcache.h in the middle of sqliteInt.h ****************/
/************** Begin file pcache.h ******************************************/

  u16 flags;                     /* PGHDR flags defined below */

  /**********************************************************************
  ** Elements above, except pCache, are public.  All that follow are
  ** private to pcache.c and should not be accessed by other modules.
  ** pCache is grouped with the public elements for efficiency.
  */
  i64 nRef;                      /* Number of users of this page */
  PgHdr *pDirtyNext;             /* Next element in list of dirty pages */
  PgHdr *pDirtyPrev;             /* Previous element in list of dirty pages */
                          /* NB: pDirtyNext and pDirtyPrev are undefined if the
                          ** PgHdr object is not dirty */
};

/* Bit values for PgHdr.flags */

/* Clear flags from pages of the page cache */
SQLITE_PRIVATE void sqlite3PcacheClearSyncFlags(PCache *);

/* Discard the contents of the cache */
SQLITE_PRIVATE void sqlite3PcacheClear(PCache*);

/* Return the total number of outstanding page references */
SQLITE_PRIVATE i64 sqlite3PcacheRefCount(PCache*);

/* Increment the reference count of an existing page */
SQLITE_PRIVATE void sqlite3PcacheRef(PgHdr*);

SQLITE_PRIVATE i64 sqlite3PcachePageRefcount(PgHdr*);

/* Return the total number of pages stored in the cache */
SQLITE_PRIVATE int sqlite3PcachePagecount(PCache*);

#if defined(SQLITE_CHECK_PAGES) || defined(SQLITE_DEBUG)
/* Iterate through all dirty pages currently stored in the cache. This
** interface is only available if SQLITE_CHECK_PAGES is defined when the

#define SQLITE_CacheSpill     0x00000020  /* OK to spill pager cache */
#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
#define SQLITE_TrustedSchema  0x00000080  /* Allow unsafe functions and
                                          ** vtabs in the schema definition */
#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                          /*   result set is empty */
#define SQLITE_IgnoreChecks   0x00000200  /* Do not enforce check constraints */
#define SQLITE_StmtScanStatus 0x00000400  /* Enable stmt_scanstats() counters */
#define SQLITE_NoCkptOnClose  0x00000800  /* No checkpoint on close()/DETACH */
#define SQLITE_ReverseOrder   0x00001000  /* Reverse unordered SELECTs */
#define SQLITE_RecTriggers    0x00002000  /* Enable recursive triggers */
#define SQLITE_ForeignKeys    0x00004000  /* Enforce foreign key constraints  */
#define SQLITE_AutoIndex      0x00008000  /* Enable automatic indexes */
#define SQLITE_LoadExtension  0x00010000  /* Enable load_extension */
#define SQLITE_LoadExtFunc    0x00020000  /* Enable load_extension() SQL func */

#define SQLITE_DqsDDL         0x20000000  /* dbl-quoted strings allowed in DDL*/
#define SQLITE_DqsDML         0x40000000  /* dbl-quoted strings allowed in DML*/
#define SQLITE_EnableView     0x80000000  /* Enable the use of views */
#define SQLITE_CountRows      HI(0x00001) /* Count rows changed by INSERT, */
                                          /*   DELETE, or UPDATE and return */
                                          /*   the count using a callback. */
#define SQLITE_CorruptRdOnly  HI(0x00002) /* Prohibit writes due to error */
#define SQLITE_ReadUncommit   HI(0x00004) /* READ UNCOMMITTED in shared-cache */

/* Flags used only if debugging */
#ifdef SQLITE_DEBUG
#define SQLITE_SqlTrace       HI(0x0100000) /* Debug print SQL as it executes */
#define SQLITE_VdbeListing    HI(0x0200000) /* Debug listings of VDBE progs */
#define SQLITE_VdbeTrace      HI(0x0400000) /* True to trace VDBE execution */
#define SQLITE_VdbeAddopTrace HI(0x0800000) /* Trace sqlite3VdbeAddOp() calls */

#define SQLITE_BloomPulldown  0x00100000 /* Run Bloom filters early */
#define SQLITE_BalancedMerge  0x00200000 /* Balance multi-way merges */
#define SQLITE_ReleaseReg     0x00400000 /* Use OP_ReleaseReg for testing */
#define SQLITE_FlttnUnionAll  0x00800000 /* Disable the UNION ALL flattener */
   /* TH3 expects this value  ^^^^^^^^^^ See flatten04.test */
#define SQLITE_IndexedExpr    0x01000000 /* Pull exprs from index when able */
#define SQLITE_Coroutines     0x02000000 /* Co-routines for subqueries */
#define SQLITE_NullUnusedCols 0x04000000 /* NULL unused columns in subqueries */
#define SQLITE_AllOpts        0xffffffff /* All optimizations */

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

*/
struct VTable {
  sqlite3 *db;              /* Database connection associated with this table */
  Module *pMod;             /* Pointer to module implementation */
  sqlite3_vtab *pVtab;      /* Pointer to vtab instance */
  int nRef;                 /* Number of pointers to this structure */
  u8 bConstraint;           /* True if constraints are supported */
  u8 bAllSchemas;           /* True if might use any attached schema */
  u8 eVtabRisk;             /* Riskiness of allowing hacker access */
  int iSavepoint;           /* Depth of the SAVEPOINT stack */
  VTable *pNext;            /* Next in linked list (see above) */
};

/* Allowed values for VTable.eVtabRisk
*/

  unsigned bNoQuery:1;     /* Do not use this index to optimize queries */
  unsigned bAscKeyBug:1;   /* True if the bba7b69f9849b5bf bug applies */
  unsigned bHasVCol:1;     /* Index references one or more VIRTUAL columns */
  unsigned bHasExpr:1;     /* Index contains an expression, either a literal
                           ** expression, or a reference to a VIRTUAL column */
#ifdef SQLITE_ENABLE_STAT4
  int nSample;             /* Number of elements in aSample[] */
  int mxSample;            /* Number of slots allocated to aSample[] */
  int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
  tRowcnt *aAvgEq;         /* Average nEq values for keys not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
  tRowcnt *aiRowEst;       /* Non-logarithmic stat1 data for this index */
  tRowcnt nRowEst0;        /* Non-logarithmic number of rows in the index */
#endif
  Bitmask colNotIdxed;     /* Unindexed columns in pTab */

#define NC_AllowAgg  0x000001 /* Aggregate functions are allowed here */
#define NC_PartIdx   0x000002 /* True if resolving a partial index WHERE */
#define NC_IsCheck   0x000004 /* True if resolving a CHECK constraint */
#define NC_GenCol    0x000008 /* True for a GENERATED ALWAYS AS clause */
#define NC_HasAgg    0x000010 /* One or more aggregate functions seen */
#define NC_IdxExpr   0x000020 /* True if resolving columns of CREATE INDEX */
#define NC_SelfRef   0x00002e /* Combo: PartIdx, isCheck, GenCol, and IdxExpr */
#define NC_Subquery  0x000040 /* A subquery has been seen */
#define NC_UEList    0x000080 /* True if uNC.pEList is used */
#define NC_UAggInfo  0x000100 /* True if uNC.pAggInfo is used */
#define NC_UUpsert   0x000200 /* True if uNC.pUpsert is used */
#define NC_UBaseReg  0x000400 /* True if uNC.iBaseReg is used */
#define NC_MinMaxAgg 0x001000 /* min/max aggregates seen.  See note above */
#define NC_Complex   0x002000 /* True if a function or subquery seen */
#define NC_AllowWin  0x004000 /* Window functions are allowed here */

  u8 okConstFactor;    /* OK to factor out constants */
  u8 disableLookaside; /* Number of times lookaside has been disabled */
  u8 prepFlags;        /* SQLITE_PREPARE_* flags */
  u8 withinRJSubrtn;   /* Nesting level for RIGHT JOIN body subroutines */
#if defined(SQLITE_DEBUG) || defined(SQLITE_COVERAGE_TEST)
  u8 earlyCleanup;     /* OOM inside sqlite3ParserAddCleanup() */
#endif
#ifdef SQLITE_DEBUG
  u8 ifNotExists;      /* Might be true if IF NOT EXISTS.  Assert()s only */
#endif
  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table associated with an index on expr, or negative

    struct WindowRewrite *pRewrite;           /* Window rewrite context */
    struct WhereConst *pConst;                /* WHERE clause constants */
    struct RenameCtx *pRename;                /* RENAME COLUMN context */
    struct Table *pTab;                       /* Table of generated column */
    struct CoveringIndexCheck *pCovIdxCk;     /* Check for covering index */
    SrcItem *pSrcItem;                        /* A single FROM clause item */
    DbFixer *pFix;                            /* See sqlite3FixSelect() */
    Mem *aMem;                                /* See sqlite3BtreeCursorHint() */
  } u;
};

/*
** The following structure contains information used by the sqliteFix...
** routines as they walk the parse tree to make database references
** explicit.

# define sqlite3Isspace(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x01)
# define sqlite3Isalnum(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x06)
# define sqlite3Isalpha(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x02)
# define sqlite3Isdigit(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x04)
# define sqlite3Isxdigit(x)  (sqlite3CtypeMap[(unsigned char)(x)]&0x08)
# define sqlite3Tolower(x)   (sqlite3UpperToLower[(unsigned char)(x)])
# define sqlite3Isquote(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x80)
# define sqlite3JsonId1(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x42)
# define sqlite3JsonId2(x)   (sqlite3CtypeMap[(unsigned char)(x)]&0x46)
#else
# define sqlite3Toupper(x)   toupper((unsigned char)(x))
# define sqlite3Isspace(x)   isspace((unsigned char)(x))
# define sqlite3Isalnum(x)   isalnum((unsigned char)(x))
# define sqlite3Isalpha(x)   isalpha((unsigned char)(x))
# define sqlite3Isdigit(x)   isdigit((unsigned char)(x))
# define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
# define sqlite3Tolower(x)   tolower((unsigned char)(x))
# define sqlite3Isquote(x)   ((x)=='"'||(x)=='\''||(x)=='['||(x)=='`')
# define sqlite3JsonId1(x)   (sqlite3IsIdChar(x)&&(x)<'0')
# define sqlite3JsonId2(x)   sqlite3IsIdChar(x)
#endif
SQLITE_PRIVATE int sqlite3IsIdChar(u8);

/*
** Internal function prototypes
*/
SQLITE_PRIVATE int sqlite3StrICmp(const char*,const char*);

SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*);
SQLITE_PRIVATE void sqlite3FinishCoding(Parse*);
SQLITE_PRIVATE int sqlite3GetTempReg(Parse*);
SQLITE_PRIVATE void sqlite3ReleaseTempReg(Parse*,int);
SQLITE_PRIVATE int sqlite3GetTempRange(Parse*,int);
SQLITE_PRIVATE void sqlite3ReleaseTempRange(Parse*,int,int);
SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse*);
SQLITE_PRIVATE void sqlite3TouchRegister(Parse*,int);
#if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
SQLITE_PRIVATE int sqlite3FirstAvailableRegister(Parse*,int);
#endif
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse*,int,int);
#endif
SQLITE_PRIVATE Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
SQLITE_PRIVATE Expr *sqlite3Expr(sqlite3*,int,const char*);
SQLITE_PRIVATE void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);
SQLITE_PRIVATE Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*);

                          Expr*, int, int, u8);
SQLITE_PRIVATE void sqlite3DropIndex(Parse*, SrcList*, int);
SQLITE_PRIVATE int sqlite3Select(Parse*, Select*, SelectDest*);
SQLITE_PRIVATE Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
                         Expr*,ExprList*,u32,Expr*);
SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3*, Select*);
SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse*, SrcList*);
SQLITE_PRIVATE int sqlite3IsReadOnly(Parse*, Table*, Trigger*);
SQLITE_PRIVATE void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
SQLITE_PRIVATE Expr *sqlite3LimitWhere(Parse*,SrcList*,Expr*,ExprList*,Expr*,char*);
#endif
SQLITE_PRIVATE void sqlite3CodeChangeCount(Vdbe*,int,const char*);
SQLITE_PRIVATE void sqlite3DeleteFrom(Parse*, SrcList*, Expr*, ExprList*, Expr*);
SQLITE_PRIVATE void sqlite3Update(Parse*, SrcList*, ExprList*,Expr*,int,ExprList*,Expr*,

SQLITE_PRIVATE int sqlite3ExprIdToTrueFalse(Expr*);
SQLITE_PRIVATE int sqlite3ExprTruthValue(const Expr*);
SQLITE_PRIVATE int sqlite3ExprIsConstant(Expr*);
SQLITE_PRIVATE int sqlite3ExprIsConstantNotJoin(Expr*);
SQLITE_PRIVATE int sqlite3ExprIsConstantOrFunction(Expr*, u8);
SQLITE_PRIVATE int sqlite3ExprIsConstantOrGroupBy(Parse*, Expr*, ExprList*);
SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr*,int);
SQLITE_PRIVATE int sqlite3ExprIsSingleTableConstraint(Expr*,const SrcList*,int);
#ifdef SQLITE_ENABLE_CURSOR_HINTS
SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr*);
#endif
SQLITE_PRIVATE int sqlite3ExprIsInteger(const Expr*, int*);
SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr*);
SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
SQLITE_PRIVATE int sqlite3IsRowid(const char*);

SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse*, Token*);
SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse*, Table*);
SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3*, int, const char *);
SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *, VTable *);

SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);


SQLITE_PRIVATE void sqlite3VtabUsesAllSchemas(Parse*);

SQLITE_PRIVATE sqlite3_int64 sqlite3StmtCurrentTime(sqlite3_context*);
SQLITE_PRIVATE int sqlite3VdbeParameterIndex(Vdbe*, const char*, int);
SQLITE_PRIVATE int sqlite3TransferBindings(sqlite3_stmt *, sqlite3_stmt *);
SQLITE_PRIVATE void sqlite3ParseObjectInit(Parse*,sqlite3*);
SQLITE_PRIVATE void sqlite3ParseObjectReset(Parse*);
SQLITE_PRIVATE void *sqlite3ParserAddCleanup(Parse*,void(*)(sqlite3*,void*),void*);
#ifdef SQLITE_ENABLE_NORMALIZE

#endif

#if defined(VDBE_PROFILE) \
 || defined(SQLITE_PERFORMANCE_TRACE) \
 || defined(SQLITE_ENABLE_STMT_SCANSTATUS)
SQLITE_PRIVATE sqlite3_uint64 sqlite3Hwtime(void);
#endif

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
# define IS_STMT_SCANSTATUS(db) (db->flags & SQLITE_StmtScanStatus)
#else
# define IS_STMT_SCANSTATUS(db) 0
#endif

#endif /* SQLITEINT_H */

/************** End of sqliteInt.h *******************************************/
/************** Begin file os_common.h ***************************************/
/*
** 2004 May 22

**
**   isspace()                        0x01
**   isalpha()                        0x02
**   isdigit()                        0x04
**   isalnum()                        0x06
**   isxdigit()                       0x08
**   toupper()                        0x20
**   SQLite identifier character      0x40   $, _, or non-ascii
**   Quote character                  0x80
**
** Bit 0x20 is set if the mapped character requires translation to upper
** case. i.e. if the character is a lower-case ASCII character.
** If x is a lower-case ASCII character, then its upper-case equivalent
** is (x - 0x20). Therefore toupper() can be implemented as:
**

#endif
   0,                         /* bLocaltimeFault */
   0,                         /* xAltLocaltime */
   0x7ffffffe,                /* iOnceResetThreshold */
   SQLITE_DEFAULT_SORTERREF_SIZE,   /* szSorterRef */
   0,                         /* iPrngSeed */
#ifdef SQLITE_DEBUG
   {0,0,0,0,0,0},             /* aTune */
#endif
};

/*
** Hash table for global functions - functions common to all
** database connections.  After initialization, this table is
** read-only.

  char validJD;       /* True (1) if iJD is valid */
  char rawS;          /* Raw numeric value stored in s */
  char validYMD;      /* True (1) if Y,M,D are valid */
  char validHMS;      /* True (1) if h,m,s are valid */
  char validTZ;       /* True (1) if tz is valid */
  char tzSet;         /* Timezone was set explicitly */
  char isError;       /* An overflow has occurred */
  char useSubsec;     /* Display subsecond precision */
};


/*
** Convert zDate into one or more integers according to the conversion
** specifier zFormat.
**

  }else if( parseHhMmSs(zDate, p)==0 ){
    return 0;
  }else if( sqlite3StrICmp(zDate,"now")==0 && sqlite3NotPureFunc(context) ){
    return setDateTimeToCurrent(context, p);
  }else if( sqlite3AtoF(zDate, &r, sqlite3Strlen30(zDate), SQLITE_UTF8)>0 ){
    setRawDateNumber(p, r);
    return 0;
  }else if( (sqlite3StrICmp(zDate,"subsec")==0
             || sqlite3StrICmp(zDate,"subsecond")==0)
           && sqlite3NotPureFunc(context) ){
    p->useSubsec = 1;
    return setDateTimeToCurrent(context, p);
  }
  return 1;
}

/* The julian day number for 9999-12-31 23:59:59.999 is 5373484.4999999.
** Multiplying this by 86400000 gives 464269060799999 as the maximum value
** for DateTime.iJD.

    }
    case 's': {
      /*
      **    start of TTTTT
      **
      ** Move the date backwards to the beginning of the current day,
      ** or month or year.
      **
      **    subsecond
      **    subsec
      **
      ** Show subsecond precision in the output of datetime() and
      ** unixepoch() and strftime('%s').
      */
      if( sqlite3_strnicmp(z, "start of ", 9)!=0 ){
        if( sqlite3_stricmp(z, "subsec")==0
         || sqlite3_stricmp(z, "subsecond")==0
        ){
          p->useSubsec = 1;
          rc = 0;
        }
        break;
      }
      if( !p->validJD && !p->validYMD && !p->validHMS ) break;
      z += 9;
      computeYMD(p);
      p->validHMS = 1;
      p->h = p->m = 0;
      p->s = 0.0;
      p->rawS = 0;

  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    computeJD(&x);
    if( x.useSubsec ){
      sqlite3_result_double(context, (x.iJD - 21086676*(i64)10000000)/1000.0);
    }else{
      sqlite3_result_int64(context, x.iJD/1000 - 21086676*(i64)10000);
    }
  }
}

/*
**    datetime( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD HH:MM:SS
*/
static void datetimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    int Y, s, n;
    char zBuf[32];
    computeYMD_HMS(&x);
    Y = x.Y;
    if( Y<0 ) Y = -Y;
    zBuf[1] = '0' + (Y/1000)%10;
    zBuf[2] = '0' + (Y/100)%10;
    zBuf[3] = '0' + (Y/10)%10;
    zBuf[4] = '0' + (Y)%10;
    zBuf[5] = '-';
    zBuf[6] = '0' + (x.M/10)%10;
    zBuf[7] = '0' + (x.M)%10;
    zBuf[8] = '-';
    zBuf[9] = '0' + (x.D/10)%10;
    zBuf[10] = '0' + (x.D)%10;
    zBuf[11] = ' ';
    zBuf[12] = '0' + (x.h/10)%10;
    zBuf[13] = '0' + (x.h)%10;
    zBuf[14] = ':';
    zBuf[15] = '0' + (x.m/10)%10;
    zBuf[16] = '0' + (x.m)%10;
    zBuf[17] = ':';
    if( x.useSubsec ){
      s = (int)1000.0*x.s;
      zBuf[18] = '0' + (s/10000)%10;
      zBuf[19] = '0' + (s/1000)%10;
      zBuf[20] = '.';
      zBuf[21] = '0' + (s/100)%10;
      zBuf[22] = '0' + (s/10)%10;
      zBuf[23] = '0' + (s)%10;
      zBuf[24] = 0;
      n = 24;
    }else{
      s = (int)x.s;
      zBuf[18] = '0' + (s/10)%10;
      zBuf[19] = '0' + (s)%10;
      zBuf[20] = 0;
      n = 20;
    }
    if( x.Y<0 ){
      zBuf[0] = '-';
      sqlite3_result_text(context, zBuf, n, SQLITE_TRANSIENT);
    }else{
      sqlite3_result_text(context, &zBuf[1], n-1, SQLITE_TRANSIENT);
    }
  }
}

/*
**    time( TIMESTRING, MOD, MOD, ...)
**
** Return HH:MM:SS
*/
static void timeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  if( isDate(context, argc, argv, &x)==0 ){
    int s, n;
    char zBuf[16];
    computeHMS(&x);
    zBuf[0] = '0' + (x.h/10)%10;
    zBuf[1] = '0' + (x.h)%10;
    zBuf[2] = ':';
    zBuf[3] = '0' + (x.m/10)%10;
    zBuf[4] = '0' + (x.m)%10;
    zBuf[5] = ':';
    if( x.useSubsec ){
      s = (int)1000.0*x.s;
      zBuf[6] = '0' + (s/10000)%10;
      zBuf[7] = '0' + (s/1000)%10;
      zBuf[8] = '.';
      zBuf[9] = '0' + (s/100)%10;
      zBuf[10] = '0' + (s/10)%10;
      zBuf[11] = '0' + (s)%10;
      zBuf[12] = 0;
      n = 12;
    }else{
      s = (int)x.s;
      zBuf[6] = '0' + (s/10)%10;
      zBuf[7] = '0' + (s)%10;
      zBuf[8] = 0;
      n = 8;
    }
    sqlite3_result_text(context, zBuf, n, SQLITE_TRANSIENT);
  }
}

/*
**    date( TIMESTRING, MOD, MOD, ...)
**
** Return YYYY-MM-DD

        break;
      }
      case 'M': {
        sqlite3_str_appendf(&sRes,"%02d",x.m);
        break;
      }
      case 's': {
        if( x.useSubsec ){
          sqlite3_str_appendf(&sRes,"%.3f",
                (x.iJD - 21086676*(i64)10000000)/1000.0);
        }else{
          i64 iS = (i64)(x.iJD/1000 - 21086676*(i64)10000);
          sqlite3_str_appendf(&sRes,"%lld",iS);
        }
        break;
      }
      case 'S': {
        sqlite3_str_appendf(&sRes,"%02d",(int)x.s);
        break;
      }
      case 'w': {

  d = digit;
  digit += '0';
  *val = (*val - d)*10.0;
  return (char)digit;
}
#endif /* SQLITE_OMIT_FLOATING_POINT */

#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** "*val" is a u64.  *msd is a divisor used to extract the
** most significant digit of *val.  Extract that most significant
** digit and return it.
*/
static char et_getdigit_int(u64 *val, u64 *msd){
  u64 x = (*val)/(*msd);
  *val -= x*(*msd);
  if( *msd>=10 ) *msd /= 10;
  return '0' + (char)(x & 15);
}
#endif /* SQLITE_OMIT_FLOATING_POINT */

/*
** Set the StrAccum object to an error mode.
*/
SQLITE_PRIVATE void sqlite3StrAccumSetError(StrAccum *p, u8 eError){
  assert( eError==SQLITE_NOMEM || eError==SQLITE_TOOBIG );
  p->accError = eError;
  if( p->mxAlloc ) sqlite3_str_reset(p);

  etByte done;               /* Loop termination flag */
  etByte cThousand;          /* Thousands separator for %d and %u */
  etByte xtype = etINVALID;  /* Conversion paradigm */
  u8 bArgList;               /* True for SQLITE_PRINTF_SQLFUNC */
  char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
  sqlite_uint64 longvalue;   /* Value for integer types */
  LONGDOUBLE_TYPE realvalue; /* Value for real types */
  sqlite_uint64 msd;         /* Divisor to get most-significant-digit
                             ** of longvalue */
  const et_info *infop;      /* Pointer to the appropriate info structure */
  char *zOut;                /* Rendering buffer */
  int nOut;                  /* Size of the rendering buffer */
  char *zExtra = 0;          /* Malloced memory used by some conversion */
#ifndef SQLITE_OMIT_FLOATING_POINT
  int  exp, e2;              /* exponent of real numbers */
  int nsd;                   /* Number of significant digits returned */

#endif
        if( realvalue<0.0 ){
          realvalue = -realvalue;
          prefix = '-';
        }else{
          prefix = flag_prefix;
        }
        exp = 0;
        if( xtype==etGENERIC && precision>0 ) precision--;
        testcase( precision>0xfff );
        if( realvalue<1.0e+16
         && realvalue==(LONGDOUBLE_TYPE)(longvalue = (u64)realvalue)
        ){
          /* Number is a pure integer that can be represented as u64 */
          for(msd=1; msd*10<=longvalue; msd *= 10, exp++){}
          if( exp>precision && xtype!=etFLOAT ){
            u64 rnd = msd/2;
            int kk = precision;
            while( kk-- > 0 ){  rnd /= 10; }
            longvalue += rnd;
          }
        }else{
          msd = 0;
          longvalue = 0;  /* To prevent a compiler warning */
          idx = precision & 0xfff;
          rounder = arRound[idx%10];
          while( idx>=10 ){ rounder *= 1.0e-10; idx -= 10; }
          if( xtype==etFLOAT ){
            double rx = (double)realvalue;
            sqlite3_uint64 u;
            int ex;
            memcpy(&u, &rx, sizeof(u));
            ex = -1023 + (int)((u>>52)&0x7ff);
            if( precision+(ex/3) < 15 ) rounder += realvalue*3e-16;
            realvalue += rounder;
          }


          if( sqlite3IsNaN((double)realvalue) ){
            if( flag_zeropad ){
              bufpt = "null";
              length = 4;
            }else{
              bufpt = "NaN";
              length = 3;
            }
            break;
          }

          /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
          if( ALWAYS(realvalue>0.0) ){
            LONGDOUBLE_TYPE scale = 1.0;
            while( realvalue>=1e100*scale && exp<=350){ scale*=1e100;exp+=100;}
            while( realvalue>=1e10*scale && exp<=350 ){ scale*=1e10; exp+=10; }
            while( realvalue>=10.0*scale && exp<=350 ){ scale *= 10.0; exp++; }
            realvalue /= scale;
            while( realvalue<1e-8 ){ realvalue *= 1e8; exp-=8; }
            while( realvalue<1.0 ){ realvalue *= 10.0; exp--; }
            if( exp>350 ){
              if( flag_zeropad ){
                realvalue = 9.0;
                exp = 999;
              }else{
                bufpt = buf;
                buf[0] = prefix;
                memcpy(buf+(prefix!=0),"Inf",4);
                length = 3+(prefix!=0);
                break;
              }
            }
            if( xtype!=etFLOAT ){
              realvalue += rounder;
              if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
            }
          }
        }

        /*
        ** If the field type is etGENERIC, then convert to either etEXP
        ** or etFLOAT, as appropriate.
        */




        if( xtype==etGENERIC ){
          flag_rtz = !flag_alternateform;
          if( exp<-4 || exp>precision ){
            xtype = etEXP;
          }else{
            precision = precision - exp;
            xtype = etFLOAT;
          }
        }else{
          flag_rtz = flag_altform2;
        }
        if( xtype==etEXP ){
          e2 = 0;
        }else{
          e2 = exp;
        }
        nsd = 16 + flag_altform2*10;
        bufpt = buf;
        {
          i64 szBufNeeded;           /* Size of a temporary buffer needed */
          szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;
          if( cThousand && e2>0 ) szBufNeeded += (e2+2)/3;
          if( szBufNeeded > etBUFSIZE ){
            bufpt = zExtra = printfTempBuf(pAccum, szBufNeeded);
            if( bufpt==0 ) return;
          }
        }
        zOut = bufpt;

        flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
        /* The sign in front of the number */
        if( prefix ){
          *(bufpt++) = prefix;
        }
        /* Digits prior to the decimal point */
        if( e2<0 ){
          *(bufpt++) = '0';
        }else if( msd>0 ){
          for(; e2>=0; e2--){
            *(bufpt++) = et_getdigit_int(&longvalue,&msd);
            if( cThousand && (e2%3)==0 && e2>1 ) *(bufpt++) = ',';
          }
        }else{
          for(; e2>=0; e2--){
            *(bufpt++) = et_getdigit(&realvalue,&nsd);
            if( cThousand && (e2%3)==0 && e2>1 ) *(bufpt++) = ',';
          }
        }
        /* The decimal point */
        if( flag_dp ){
          *(bufpt++) = '.';
        }
        /* "0" digits after the decimal point but before the first
        ** significant digit of the number */
        for(e2++; e2<0; precision--, e2++){
          assert( precision>0 );
          *(bufpt++) = '0';
        }
        /* Significant digits after the decimal point */
        if( msd>0 ){
          while( (precision--)>0 ){
            *(bufpt++) = et_getdigit_int(&longvalue,&msd);
          }
        }else{
          while( (precision--)>0 ){
            *(bufpt++) = et_getdigit(&realvalue,&nsd);
          }
        }
        /* Remove trailing zeros and the "." if no digits follow the "." */
        if( flag_rtz && flag_dp ){
          while( bufpt[-1]=='0' ) *(--bufpt) = 0;
          assert( bufpt>zOut );
          if( bufpt[-1]=='.' ){
            if( flag_altform2 ){

#endif
  sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
  sqlite3_str_vappendf(&acc, zFormat, ap);
  zBuf[acc.nChar] = 0;
  return zBuf;
}
SQLITE_API char *sqlite3_snprintf(int n, char *zBuf, const char *zFormat, ...){
  StrAccum acc;
  va_list ap;
  if( n<=0 ) return zBuf;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( zBuf==0 || zFormat==0 ) {
    (void)SQLITE_MISUSE_BKPT;
    if( zBuf ) zBuf[0] = 0;
    return zBuf;
  }
#endif
  sqlite3StrAccumInit(&acc, 0, zBuf, n, 0);
  va_start(ap,zFormat);
  sqlite3_str_vappendf(&acc, zFormat, ap);
  va_end(ap);
  zBuf[acc.nChar] = 0;
  return zBuf;
}

/*
** This is the routine that actually formats the sqlite3_log() message.
** We house it in a separate routine from sqlite3_log() to avoid using
** stack space on small-stack systems when logging is disabled.
**

  if( v<0 ){
    x = (v==SMALLEST_INT64) ? ((u64)1)<<63 : (u64)-v;
  }else{
    x = v;
  }
  i = sizeof(zTemp)-2;
  zTemp[sizeof(zTemp)-1] = 0;

  while( 1 /*exit-by-break*/ ){
    zTemp[i] = (x%10) + '0';
    x = x/10;
    if( x==0 ) break;
    i--;
  };
  if( v<0 ) zTemp[--i] = '-';
  memcpy(zOut, &zTemp[i], sizeof(zTemp)-i);
  return sizeof(zTemp)-1-i;
}

/*
** Compare the 19-character string zNum against the text representation
** value 2^63:  9223372036854775808.  Return negative, zero, or positive
** if zNum is less than, equal to, or greater than the string.
** Note that zNum must contain exactly 19 characters.

    u64 u = 0;
    int i, k;
    for(i=2; z[i]=='0'; i++){}
    for(k=i; sqlite3Isxdigit(z[k]); k++){
      u = u*16 + sqlite3HexToInt(z[k]);
    }
    memcpy(pOut, &u, 8);
    if( k-i>16 ) return 2;
    if( z[k]!=0 ) return 1;
    return 0;
  }else
#endif /* SQLITE_OMIT_HEX_INTEGER */
  {
    return sqlite3Atoi64(z, pOut, sqlite3Strlen30(z), SQLITE_UTF8);
  }
}

  else if( zNum[0]=='0'
        && (zNum[1]=='x' || zNum[1]=='X')
        && sqlite3Isxdigit(zNum[2])
  ){
    u32 u = 0;
    zNum += 2;
    while( zNum[0]=='0' ) zNum++;
    for(i=0; i<8 && sqlite3Isxdigit(zNum[i]); i++){
      u = u*16 + sqlite3HexToInt(zNum[i]);
    }
    if( (u&0x80000000)==0 && sqlite3Isxdigit(zNum[i])==0 ){
      memcpy(pValue, &u, 4);
      return 1;
    }else{
      return 0;

#    define SQLITE_ENABLE_LOCKING_STYLE 1
#  else
#    define SQLITE_ENABLE_LOCKING_STYLE 0
#  endif
#endif

/* Use pread() and pwrite() if they are available */
#if defined(__APPLE__) || defined(__linux__)
# define HAVE_PREAD 1
# define HAVE_PWRITE 1
#endif
#if defined(HAVE_PREAD64) && defined(HAVE_PWRITE64)
# undef USE_PREAD
# define USE_PREAD64 1
#elif defined(HAVE_PREAD) && defined(HAVE_PWRITE)

** are gather together into this division.
*/

/*
** Seek to the offset passed as the second argument, then read cnt
** bytes into pBuf. Return the number of bytes actually read.
**






** 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;
  int prior = 0;
#if (!defined(USE_PREAD) && !defined(USE_PREAD64))

                        dwShareMode,
                        dwCreationDisposition,
                        &extendedParameters);
      if( h!=INVALID_HANDLE_VALUE ) break;
      if( isReadWrite ){
        int rc2, isRO = 0;
        sqlite3BeginBenignMalloc();
        rc2 = winAccess(pVfs, zUtf8Name, SQLITE_ACCESS_READ, &isRO);
        sqlite3EndBenignMalloc();
        if( rc2==SQLITE_OK && isRO ) break;
      }
    }while( winRetryIoerr(&cnt, &lastErrno) );
#else
    do{
      h = osCreateFileW((LPCWSTR)zConverted,
                        dwDesiredAccess,
                        dwShareMode, NULL,
                        dwCreationDisposition,
                        dwFlagsAndAttributes,
                        NULL);
      if( h!=INVALID_HANDLE_VALUE ) break;
      if( isReadWrite ){
        int rc2, isRO = 0;
        sqlite3BeginBenignMalloc();
        rc2 = winAccess(pVfs, zUtf8Name, SQLITE_ACCESS_READ, &isRO);
        sqlite3EndBenignMalloc();
        if( rc2==SQLITE_OK && isRO ) break;
      }
    }while( winRetryIoerr(&cnt, &lastErrno) );
#endif
  }
#ifdef SQLITE_WIN32_HAS_ANSI
  else{
    do{
      h = osCreateFileA((LPCSTR)zConverted,
                        dwDesiredAccess,
                        dwShareMode, NULL,
                        dwCreationDisposition,
                        dwFlagsAndAttributes,
                        NULL);
      if( h!=INVALID_HANDLE_VALUE ) break;
      if( isReadWrite ){
        int rc2, isRO = 0;
        sqlite3BeginBenignMalloc();
        rc2 = winAccess(pVfs, zUtf8Name, SQLITE_ACCESS_READ, &isRO);
        sqlite3EndBenignMalloc();
        if( rc2==SQLITE_OK && isRO ) break;
      }
    }while( winRetryIoerr(&cnt, &lastErrno) );
  }
#endif
  winLogIoerr(cnt, __LINE__);

  DWORD lastErrno = 0;
  void *zConverted;
  UNUSED_PARAMETER(pVfs);

  SimulateIOError( return SQLITE_IOERR_ACCESS; );
  OSTRACE(("ACCESS name=%s, flags=%x, pResOut=%p\n",
           zFilename, flags, pResOut));

  if( zFilename==0 ){
    *pResOut = 0;
    OSTRACE(("ACCESS name=%s, pResOut=%p, *pResOut=%d, rc=SQLITE_OK\n",
             zFilename, pResOut, *pResOut));
    return SQLITE_OK;
  }

  zConverted = winConvertFromUtf8Filename(zFilename);
  if( zConverted==0 ){
    OSTRACE(("ACCESS name=%s, rc=SQLITE_IOERR_NOMEM\n", zFilename));
    return SQLITE_IOERR_NOMEM_BKPT;
  }
  if( osIsNT() ){

**   clear PGHDR_NEED_SYNC flag or to a page that is older than this one
**   (so that the right page to eject can be found by following pDirtyPrev
**   pointers).
*/
struct PCache {
  PgHdr *pDirty, *pDirtyTail;         /* List of dirty pages in LRU order */
  PgHdr *pSynced;                     /* Last synced page in dirty page list */
  i64 nRefSum;                        /* Sum of ref counts over all pages */
  int szCache;                        /* Configured cache size */
  int szSpill;                        /* Size before spilling occurs */
  int szPage;                         /* Size of every page in this cache */
  int szExtra;                        /* Size of extra space for each page */
  u8 bPurgeable;                      /* True if pages are on backing store */
  u8 eCreate;                         /* eCreate value for for xFetch() */
  int (*xStress)(void*,PgHdr*);       /* Call to try make a page clean */

  int sqlite3PcacheTrace = 2;       /* 0: off  1: simple  2: cache dumps */
  int sqlite3PcacheMxDump = 9999;   /* Max cache entries for pcacheDump() */
# define pcacheTrace(X) if(sqlite3PcacheTrace){sqlite3DebugPrintf X;}
  static void pcachePageTrace(int i, sqlite3_pcache_page *pLower){
    PgHdr *pPg;
    unsigned char *a;
    int j;
    if( pLower==0 ){
      printf("%3d: NULL\n", i);
    }else{
      pPg = (PgHdr*)pLower->pExtra;
      printf("%3d: nRef %2lld flgs %02x data ", i, pPg->nRef, pPg->flags);
      a = (unsigned char *)pLower->pBuf;
      for(j=0; j<12; j++) printf("%02x", a[j]);
      printf(" ptr %p\n", pPg);
    }
  }
  static void pcacheDump(PCache *pCache){
    int N;
    int i;
    sqlite3_pcache_page *pLower;

    if( sqlite3PcacheTrace<2 ) return;
    if( pCache->pCache==0 ) return;
    N = sqlite3PcachePagecount(pCache);
    if( N>sqlite3PcacheMxDump ) N = sqlite3PcacheMxDump;
    for(i=1; i<=N; i++){
       pLower = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, i, 0);

       pcachePageTrace(i, pLower);
       if( pLower && ((PgHdr*)pLower)->pPage==0 ){
         sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, pLower, 0);
       }
    }
  }
#else
# define pcacheTrace(X)
# define pcachePageTrace(PGNO, X)

/*
** Return the total number of references to all pages held by the cache.
**
** This is not the total number of pages referenced, but the sum of the
** reference count for all pages.
*/
SQLITE_PRIVATE i64 sqlite3PcacheRefCount(PCache *pCache){
  return pCache->nRefSum;
}

/*
** Return the number of references to the page supplied as an argument.
*/
SQLITE_PRIVATE i64 sqlite3PcachePageRefcount(PgHdr *p){
  return p->nRef;
}

/*
** Return the total number of pages in the cache.
*/
SQLITE_PRIVATE int sqlite3PcachePagecount(PCache *pCache){

** If successful, return SQLITE_OK. If an IO error occurs while modifying
** the database file, return the error code to the caller.
*/
static int pager_truncate(Pager *pPager, Pgno nPage){
  int rc = SQLITE_OK;
  assert( pPager->eState!=PAGER_ERROR );
  assert( pPager->eState!=PAGER_READER );
  PAGERTRACE(("Truncate %d npage %u\n", PAGERID(pPager), nPage));


  if( isOpen(pPager->fd)
   && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)
  ){
    i64 currentSize, newSize;
    int szPage = pPager->pageSize;
    assert( pPager->eLock==EXCLUSIVE_LOCK );

    pPg->pPager = pPager;

    assert( !isOpen(pPager->fd) || !MEMDB );
    if( !isOpen(pPager->fd) || pPager->dbSize<pgno || noContent ){
      if( pgno>pPager->mxPgno ){
        rc = SQLITE_FULL;
        if( pgno<=pPager->dbSize ){
          sqlite3PcacheRelease(pPg);
          pPg = 0;
        }
        goto pager_acquire_err;
      }
      if( noContent ){
        /* Failure to set the bits in the InJournal bit-vectors is benign.
        ** It merely means that we might do some extra work to journal a
        ** page that does not need to be journaled.  Nevertheless, be sure
        ** to test the case where a malloc error occurs while trying to set

  if( pPage==0 ) return 0;
  return sqlite3PcacheFetchFinish(pPager->pPCache, pgno, pPage);
}

/*
** Release a page reference.
**
** The sqlite3PagerUnref() and sqlite3PagerUnrefNotNull() may only be used
** if we know that the page being released is not the last reference to page1.
** The btree layer always holds page1 open until the end, so these first
** two routines can be used to release any page other than BtShared.pPage1.
** The assert() at tag-20230419-2 proves that this constraint is always
** honored.
**
** Use sqlite3PagerUnrefPageOne() to release page1.  This latter routine
** checks the total number of outstanding pages and if the number of
** pages reaches zero it drops the database lock.
*/
SQLITE_PRIVATE void sqlite3PagerUnrefNotNull(DbPage *pPg){
  TESTONLY( Pager *pPager = pPg->pPager; )
  assert( pPg!=0 );
  if( pPg->flags & PGHDR_MMAP ){
    assert( pPg->pgno!=1 );  /* Page1 is never memory mapped */
    pagerReleaseMapPage(pPg);
  }else{
    sqlite3PcacheRelease(pPg);
  }
  /* Do not use this routine to release the last reference to page1 */
  assert( sqlite3PcacheRefCount(pPager->pPCache)>0 ); /* tag-20230419-2 */
}
SQLITE_PRIVATE void sqlite3PagerUnref(DbPage *pPg){
  if( pPg ) sqlite3PagerUnrefNotNull(pPg);
}
SQLITE_PRIVATE void sqlite3PagerUnrefPageOne(DbPage *pPg){
  Pager *pPager;
  assert( pPg!=0 );

/*
** Attempt to take an exclusive lock on the database file. If a PENDING lock
** is obtained instead, immediately release it.
*/
static int pagerExclusiveLock(Pager *pPager){
  int rc;                         /* Return code */
  u8 eOrigLock;                   /* Original lock */

  assert( pPager->eLock>=SHARED_LOCK );
  eOrigLock = pPager->eLock;
  rc = pagerLockDb(pPager, EXCLUSIVE_LOCK);
  if( rc!=SQLITE_OK ){
    /* If the attempt to grab the exclusive lock failed, release the
    ** pending lock that may have been obtained instead.  */
    pagerUnlockDb(pPager, eOrigLock);
  }

  return rc;
}

/*
** Call sqlite3WalOpen() to open the WAL handle. If the pager is in

  }else{
    s1 = s2 = 0;
  }

  assert( nByte>=8 );
  assert( (nByte&0x00000007)==0 );
  assert( nByte<=65536 );
  assert( nByte%4==0 );

  if( !nativeCksum ){





    do {
      s1 += BYTESWAP32(aData[0]) + s2;
      s2 += BYTESWAP32(aData[1]) + s1;
      aData += 2;
    }while( aData<aEnd );
  }else if( nByte%64==0 ){
    do {
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
    }while( aData<aEnd );
  }else{
    do {
      s1 += *aData++ + s2;
      s2 += *aData++ + s1;
    }while( aData<aEnd );
  }
  assert( aData==aEnd );

  aOut[0] = s1;
  aOut[1] = s2;
}

/*
** If there is the possibility of concurrent access to the SHM file

    **     https://sqlite.org/src/info/ff5be73dee
    */
    if( pWal->syncHeader ){
      rc = sqlite3OsSync(pWal->pWalFd, CKPT_SYNC_FLAGS(sync_flags));
      if( rc ) return rc;
    }
  }
  if( (int)pWal->szPage!=szPage ){
    return SQLITE_CORRUPT_BKPT;  /* TH3 test case: cov1/corrupt155.test */
  }

  /* Setup information needed to write frames into the WAL */
  w.pWal = pWal;
  w.pFd = pWal->pWalFd;
  w.iSyncPoint = 0;
  w.syncFlags = sync_flags;
  w.szPage = szPage;

** contiguous or in order, but cell pointers are contiguous and in order.
**
** Cell content makes use of variable length integers.  A variable
** length integer is 1 to 9 bytes where the lower 7 bits of each
** byte are used.  The integer consists of all bytes that have bit 8 set and
** the first byte with bit 8 clear.  The most significant byte of the integer
** appears first.  A variable-length integer may not be more than 9 bytes long.
** As a special case, all 8 bits of the 9th byte are used as data.  This
** allows a 64-bit integer to be encoded in 9 bytes.
**
**    0x00                      becomes  0x00000000
**    0x7f                      becomes  0x0000007f
**    0x81 0x00                 becomes  0x00000080
**    0x82 0x00                 becomes  0x00000100
**    0x80 0x7f                 becomes  0x0000007f

/*
** Legal values for BtCursor.curFlags
*/
#define BTCF_WriteFlag    0x01   /* True if a write cursor */
#define BTCF_ValidNKey    0x02   /* True if info.nKey is valid */
#define BTCF_ValidOvfl    0x04   /* True if aOverflow is valid */
#define BTCF_AtLast       0x08   /* Cursor is pointing to the last entry */
#define BTCF_Incrblob     0x10   /* True if an incremental I/O handle */
#define BTCF_Multiple     0x20   /* Maybe another cursor on the same btree */
#define BTCF_Pinned       0x40   /* Cursor is busy and cannot be moved */

/*
** Potential values for BtCursor.eState.
**

  u8 *aPgRef;       /* 1 bit per page in the db (see above) */
  Pgno nPage;       /* Number of pages in the database */
  int mxErr;        /* Stop accumulating errors when this reaches zero */
  int nErr;         /* Number of messages written to zErrMsg so far */
  int rc;           /* SQLITE_OK, SQLITE_NOMEM, or SQLITE_INTERRUPT */
  u32 nStep;        /* Number of steps into the integrity_check process */
  const char *zPfx; /* Error message prefix */
  Pgno v0;          /* Value for first %u substitution in zPfx (root page) */
  Pgno v1;          /* Value for second %u substitution in zPfx (current pg) */
  int v2;           /* Value for third %d substitution in zPfx */
  StrAccum errMsg;  /* Accumulate the error message text here */
  u32 *heap;        /* Min-heap used for analyzing cell coverage */
  sqlite3 *db;      /* Database connection running the check */
};

/*
** Routines to read or write a two- and four-byte big-endian integer values.

** normally produced as a side-effect of SQLITE_CORRUPT_BKPT is augmented
** with the page number and filename associated with the (MemPage*).
*/
#ifdef SQLITE_DEBUG
int corruptPageError(int lineno, MemPage *p){
  char *zMsg;
  sqlite3BeginBenignMalloc();
  zMsg = sqlite3_mprintf("database corruption page %u of %s",
             p->pgno, sqlite3PagerFilename(p->pBt->pPager, 0)
  );
  sqlite3EndBenignMalloc();
  if( zMsg ){
    sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
  }
  sqlite3_free(zMsg);
  return SQLITE_CORRUPT_BKPT;

/*
** Provide hints to the cursor.  The particular hint given (and the type
** and number of the varargs parameters) is determined by the eHintType
** parameter.  See the definitions of the BTREE_HINT_* macros for details.
*/
SQLITE_PRIVATE void sqlite3BtreeCursorHint(BtCursor *pCur, int eHintType, ...){
  /* Used only by system that substitute their own storage engine */
#ifdef SQLITE_DEBUG
  if( ALWAYS(eHintType==BTREE_HINT_RANGE) ){
    va_list ap;
    Expr *pExpr;
    Walker w;
    memset(&w, 0, sizeof(w));
    w.xExprCallback = sqlite3CursorRangeHintExprCheck;
    va_start(ap, eHintType);
    pExpr = va_arg(ap, Expr*);
    w.u.aMem = va_arg(ap, Mem*);
    va_end(ap);
    assert( pExpr!=0 );
    assert( w.u.aMem!=0 );
    sqlite3WalkExpr(&w, pExpr);
  }
#endif /* SQLITE_DEBUG */
}
#endif /* SQLITE_ENABLE_CURSOR_HINTS */


/*
** Provide flag hints to the cursor.
*/
SQLITE_PRIVATE void sqlite3BtreeCursorHintFlags(BtCursor *pCur, unsigned x){
  assert( x==BTREE_SEEK_EQ || x==BTREE_BULKLOAD || x==0 );
  pCur->hints = x;

    *pRC = SQLITE_CORRUPT_BKPT;
    goto ptrmap_exit;
  }
  assert( offset <= (int)pBt->usableSize-5 );
  pPtrmap = (u8 *)sqlite3PagerGetData(pDbPage);

  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=parent ){
    TRACE(("PTRMAP_UPDATE: %u->(%u,%u)\n", key, eType, parent));
    *pRC= rc = sqlite3PagerWrite(pDbPage);
    if( rc==SQLITE_OK ){
      pPtrmap[offset] = eType;
      put4byte(&pPtrmap[offset+1], parent);
    }
  }

  **
  ** The code is inlined and the loop is unrolled for performance.
  ** This routine is a high-runner.
  */
  iKey = *pIter;
  if( iKey>=0x80 ){
    u8 x;
    iKey = (iKey<<7) ^ (x = *++pIter);
    if( x>=0x80 ){
      iKey = (iKey<<7) ^ (x = *++pIter);
      if( x>=0x80 ){
        iKey = (iKey<<7) ^ 0x10204000 ^ (x = *++pIter);
        if( x>=0x80 ){
          iKey = (iKey<<7) ^ 0x4000 ^ (x = *++pIter);
          if( x>=0x80 ){
            iKey = (iKey<<7) ^ 0x4000 ^ (x = *++pIter);
            if( x>=0x80 ){
              iKey = (iKey<<7) ^ 0x4000 ^ (x = *++pIter);
              if( x>=0x80 ){
                iKey = (iKey<<7) ^ 0x4000 ^ (x = *++pIter);
                if( x>=0x80 ){
                  iKey = (iKey<<8) ^ 0x8000 ^ (*++pIter);
                }
              }
            }
          }
        }
      }else{
        iKey ^= 0x204000;
      }
    }else{
      iKey ^= 0x4000;
    }
  }
  pIter++;

  pInfo->nKey = *(i64*)&iKey;
  pInfo->nPayload = nPayload;
  pInfo->pPayload = pIter;

** Compute the total number of bytes that a Cell needs in the cell
** data area of the btree-page.  The return number includes the cell
** data header and the local payload, but not any overflow page or
** the space used by the cell pointer.
**
** cellSizePtrNoPayload()    =>   table internal nodes
** cellSizePtrTableLeaf()    =>   table leaf nodes
** cellSizePtr()             =>   index internal nodes
** cellSizeIdxLeaf()         =>   index leaf nodes
*/
static u16 cellSizePtr(MemPage *pPage, u8 *pCell){
  u8 *pIter = pCell + 4;                   /* For looping over bytes of pCell */
  u8 *pEnd;                                /* End mark for a varint */
  u32 nSize;                               /* Size value to return */

#ifdef SQLITE_DEBUG
  /* The value returned by this function should always be the same as
  ** the (CellInfo.nSize) value found by doing a full parse of the
  ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
  ** this function verifies that this invariant is not violated. */
  CellInfo debuginfo;
  pPage->xParseCell(pPage, pCell, &debuginfo);
#endif

  assert( pPage->childPtrSize==4 );
  nSize = *pIter;
  if( nSize>=0x80 ){
    pEnd = &pIter[8];
    nSize &= 0x7f;
    do{
      nSize = (nSize<<7) | (*++pIter & 0x7f);
    }while( *(pIter)>=0x80 && pIter<pEnd );
  }
  pIter++;
  testcase( nSize==pPage->maxLocal );
  testcase( nSize==(u32)pPage->maxLocal+1 );
  if( nSize<=pPage->maxLocal ){
    nSize += (u32)(pIter - pCell);
    assert( nSize>4 );
  }else{
    int minLocal = pPage->minLocal;
    nSize = minLocal + (nSize - minLocal) % (pPage->pBt->usableSize - 4);
    testcase( nSize==pPage->maxLocal );
    testcase( nSize==(u32)pPage->maxLocal+1 );
    if( nSize>pPage->maxLocal ){
      nSize = minLocal;
    }
    nSize += 4 + (u16)(pIter - pCell);
  }
  assert( nSize==debuginfo.nSize || CORRUPT_DB );
  return (u16)nSize;
}
static u16 cellSizePtrIdxLeaf(MemPage *pPage, u8 *pCell){
  u8 *pIter = pCell;                       /* For looping over bytes of pCell */
  u8 *pEnd;                                /* End mark for a varint */
  u32 nSize;                               /* Size value to return */

#ifdef SQLITE_DEBUG
  /* The value returned by this function should always be the same as
  ** the (CellInfo.nSize) value found by doing a full parse of the
  ** cell. If SQLITE_DEBUG is defined, an assert() at the bottom of
  ** this function verifies that this invariant is not violated. */
  CellInfo debuginfo;
  pPage->xParseCell(pPage, pCell, &debuginfo);
#endif

  assert( pPage->childPtrSize==0 );
  nSize = *pIter;
  if( nSize>=0x80 ){
    pEnd = &pIter[8];
    nSize &= 0x7f;
    do{
      nSize = (nSize<<7) | (*++pIter & 0x7f);
    }while( *(pIter)>=0x80 && pIter<pEnd );

      pAddr = &data[cellOffset + i*2];
      pc = get2byte(pAddr);
      testcase( pc==iCellFirst );
      testcase( pc==iCellLast );
      /* These conditions have already been verified in btreeInitPage()
      ** if PRAGMA cell_size_check=ON.
      */
      if( pc>iCellLast ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      assert( pc>=0 && pc<=iCellLast );
      size = pPage->xCellSize(pPage, &src[pc]);
      cbrk -= size;
      if( cbrk<iCellStart || pc+size>usableSize ){
        return SQLITE_CORRUPT_PAGE(pPage);
      }
      assert( cbrk+size<=usableSize && cbrk>=iCellStart );
      testcase( cbrk+size==usableSize );

** The caller guarantees that there is sufficient space to make the
** allocation.  This routine might need to defragment in order to bring
** all the space together, however.  This routine will avoid using
** the first two bytes past the cell pointer area since presumably this
** allocation is being made in order to insert a new cell, so we will
** also end up needing a new cell pointer.
*/
static SQLITE_INLINE int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
  const int hdr = pPage->hdrOffset;    /* Local cache of pPage->hdrOffset */
  u8 * const data = pPage->aData;      /* Local cache of pPage->aData */
  int top;                             /* First byte of cell content area */
  int rc = SQLITE_OK;                  /* Integer return code */
  u8 *pTmp;                            /* Temp ptr into data[] */
  int gap;        /* First byte of gap between cell pointers and cell content */

  /* EVIDENCE-OF: R-29356-02391 If the database uses a 65536-byte page size
  ** and the reserved space is zero (the usual value for reserved space)
  ** then the cell content offset of an empty page wants to be 65536.
  ** However, that integer is too large to be stored in a 2-byte unsigned
  ** integer, so a value of 0 is used in its place. */
  pTmp = &data[hdr+5];
  top = get2byte(pTmp);

  if( gap>top ){
    if( top==0 && pPage->pBt->usableSize==65536 ){
      top = 65536;
    }else{
      return SQLITE_CORRUPT_PAGE(pPage);
    }
  }else if( top>(int)pPage->pBt->usableSize ){
    return SQLITE_CORRUPT_PAGE(pPage);
  }

  /* If there is enough space between gap and top for one more cell pointer,
  ** and if the freelist is not empty, then search the
  ** freelist looking for a slot big enough to satisfy the request.
  */
  testcase( gap+2==top );

  assert( pPage->pBt!=0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( CORRUPT_DB || iStart>=pPage->hdrOffset+6+pPage->childPtrSize );
  assert( CORRUPT_DB || iEnd <= pPage->pBt->usableSize );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( iSize>=4 );   /* Minimum cell size is 4 */
  assert( CORRUPT_DB || iStart<=pPage->pBt->usableSize-4 );

  /* The list of freeblocks must be in ascending order.  Find the
  ** spot on the list where iStart should be inserted.
  */
  hdr = pPage->hdrOffset;
  iPtr = hdr + 1;
  if( data[iPtr+1]==0 && data[iPtr]==0 ){

      }
    }
    if( nFrag>data[hdr+7] ) return SQLITE_CORRUPT_PAGE(pPage);
    data[hdr+7] -= nFrag;
  }
  pTmp = &data[hdr+5];
  x = get2byte(pTmp);
  if( pPage->pBt->btsFlags & BTS_FAST_SECURE ){
    /* Overwrite deleted information with zeros when the secure_delete
    ** option is enabled */
    memset(&data[iStart], 0, iSize);
  }
  if( iStart<=x ){
    /* The new freeblock is at the beginning of the cell content area,
    ** so just extend the cell content area rather than create another
    ** freelist entry */
    if( iStart<x ) return SQLITE_CORRUPT_PAGE(pPage);
    if( iPtr!=hdr+1 ) return SQLITE_CORRUPT_PAGE(pPage);
    put2byte(&data[hdr+1], iFreeBlk);
    put2byte(&data[hdr+5], iEnd);
  }else{
    /* Insert the new freeblock into the freelist */
    put2byte(&data[iPtr], iStart);






    put2byte(&data[iStart], iFreeBlk);
    put2byte(&data[iStart+2], iSize);
  }
  pPage->nFree += iOrigSize;
  return SQLITE_OK;
}

/*
** Decode the flags byte (the first byte of the header) for a page
** and initialize fields of the MemPage structure accordingly.

      pPage->xParseCell = btreeParseCellPtr;
      pPage->intKey = 1;
      pPage->maxLocal = pBt->maxLeaf;
      pPage->minLocal = pBt->minLeaf;
    }else if( flagByte==(PTF_ZERODATA | PTF_LEAF) ){
      pPage->intKey = 0;
      pPage->intKeyLeaf = 0;
      pPage->xCellSize = cellSizePtrIdxLeaf;
      pPage->xParseCell = btreeParseCellPtrIndex;
      pPage->maxLocal = pBt->maxLocal;
      pPage->minLocal = pBt->minLocal;
    }else{
      pPage->intKey = 0;
      pPage->intKeyLeaf = 0;
      pPage->xCellSize = cellSizePtrIdxLeaf;
      pPage->xParseCell = btreeParseCellPtrIndex;
      return SQLITE_CORRUPT_PAGE(pPage);
    }
  }else{
    pPage->childPtrSize = 4;
    pPage->leaf = 0;
    if( flagByte==(PTF_ZERODATA) ){

  assert( eType==PTRMAP_OVERFLOW2 || eType==PTRMAP_OVERFLOW1 ||
      eType==PTRMAP_BTREE || eType==PTRMAP_ROOTPAGE );
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( pDbPage->pBt==pBt );
  if( iDbPage<3 ) return SQLITE_CORRUPT_BKPT;

  /* Move page iDbPage from its current location to page number iFreePage */
  TRACE(("AUTOVACUUM: Moving %u to free page %u (ptr page %u type %u)\n",
      iDbPage, iFreePage, iPtrPage, eType));
  rc = sqlite3PagerMovepage(pPager, pDbPage->pDbPage, iFreePage, isCommit);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pDbPage->pgno = iFreePage;

      pCur->eState = CURSOR_VALID;
      if( pCur->skipNext>0 ) return SQLITE_OK;
    }
  }

  pPage = pCur->pPage;
  idx = ++pCur->ix;
  if( sqlite3FaultSim(412) ) pPage->isInit = 0;
  if( !pPage->isInit ){
    return SQLITE_CORRUPT_BKPT;
  }

  if( idx>=pPage->nCell ){
    if( !pPage->leaf ){
      rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
      if( rc ) return rc;

        if( rc ){
          goto end_allocate_page;
        }
        *pPgno = iTrunk;
        memcpy(&pPage1->aData[32], &pTrunk->aData[0], 4);
        *ppPage = pTrunk;
        pTrunk = 0;
        TRACE(("ALLOCATE: %u trunk - %u free pages left\n", *pPgno, n-1));
      }else if( k>(u32)(pBt->usableSize/4 - 2) ){
        /* Value of k is out of range.  Database corruption */
        rc = SQLITE_CORRUPT_PGNO(iTrunk);
        goto end_allocate_page;
#ifndef SQLITE_OMIT_AUTOVACUUM
      }else if( searchList
            && (nearby==iTrunk || (iTrunk<nearby && eMode==BTALLOC_LE))

            if( rc ){
              goto end_allocate_page;
            }
            put4byte(&pPrevTrunk->aData[0], iNewTrunk);
          }
        }
        pTrunk = 0;
        TRACE(("ALLOCATE: %u trunk - %u free pages left\n", *pPgno, n-1));
#endif
      }else if( k>0 ){
        /* Extract a leaf from the trunk */
        u32 closest;
        Pgno iPage;
        unsigned char *aData = pTrunk->aData;
        if( nearby>0 ){

        }
        testcase( iPage==mxPage );
        if( !searchList
         || (iPage==nearby || (iPage<nearby && eMode==BTALLOC_LE))
        ){
          int noContent;
          *pPgno = iPage;
          TRACE(("ALLOCATE: %u was leaf %u of %u on trunk %u"
                 ": %u more free pages\n",
                 *pPgno, closest+1, k, pTrunk->pgno, n-1));
          rc = sqlite3PagerWrite(pTrunk->pDbPage);
          if( rc ) goto end_allocate_page;
          if( closest<k-1 ){
            memcpy(&aData[8+closest*4], &aData[4+k*4], 4);
          }
          put4byte(&aData[4], k-1);

#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && PTRMAP_ISPAGE(pBt, pBt->nPage) ){
      /* If *pPgno refers to a pointer-map page, allocate two new pages
      ** at the end of the file instead of one. The first allocated page
      ** becomes a new pointer-map page, the second is used by the caller.
      */
      MemPage *pPg = 0;
      TRACE(("ALLOCATE: %u from end of file (pointer-map page)\n", pBt->nPage));
      assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );
      rc = btreeGetUnusedPage(pBt, pBt->nPage, &pPg, bNoContent);
      if( rc==SQLITE_OK ){
        rc = sqlite3PagerWrite(pPg->pDbPage);
        releasePage(pPg);
      }
      if( rc ) return rc;

    rc = btreeGetUnusedPage(pBt, *pPgno, ppPage, bNoContent);
    if( rc ) return rc;
    rc = sqlite3PagerWrite((*ppPage)->pDbPage);
    if( rc!=SQLITE_OK ){
      releasePage(*ppPage);
      *ppPage = 0;
    }
    TRACE(("ALLOCATE: %u from end of file\n", *pPgno));
  }

  assert( CORRUPT_DB || *pPgno!=PENDING_BYTE_PAGE(pBt) );

end_allocate_page:
  releasePage(pTrunk);
  releasePage(pPrevTrunk);

        put4byte(&pTrunk->aData[4], nLeaf+1);
        put4byte(&pTrunk->aData[8+nLeaf*4], iPage);
        if( pPage && (pBt->btsFlags & BTS_SECURE_DELETE)==0 ){
          sqlite3PagerDontWrite(pPage->pDbPage);
        }
        rc = btreeSetHasContent(pBt, iPage);
      }
      TRACE(("FREE-PAGE: %u leaf on trunk page %u\n",pPage->pgno,pTrunk->pgno));
      goto freepage_out;
    }
  }

  /* If control flows to this point, then it was not possible to add the
  ** the page being freed as a leaf page of the first trunk in the free-list.
  ** Possibly because the free-list is empty, or possibly because the
  ** first trunk in the free-list is full. Either way, the page being freed
  ** will become the new first trunk page in the free-list.
  */
  if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0)) ){
    goto freepage_out;
  }
  rc = sqlite3PagerWrite(pPage->pDbPage);
  if( rc!=SQLITE_OK ){
    goto freepage_out;
  }
  put4byte(pPage->aData, iTrunk);
  put4byte(&pPage->aData[4], 0);
  put4byte(&pPage1->aData[32], iPage);
  TRACE(("FREE-PAGE: %u new trunk page replacing %u\n", pPage->pgno, iTrunk));

freepage_out:
  if( pPage ){
    pPage->isInit = 0;
  }
  releasePage(pPage);
  releasePage(pTrunk);

** If the cell content will fit on the page, then put it there.  If it
** will not fit, then make a copy of the cell content into pTemp if
** pTemp is not null.  Regardless of pTemp, allocate a new entry
** in pPage->apOvfl[] and make it point to the cell content (either
** in pTemp or the original pCell) and also record its index.
** Allocating a new entry in pPage->aCell[] implies that
** pPage->nOverflow is incremented.
**
** The insertCellFast() routine below works exactly the same as
** insertCell() except that it lacks the pTemp and iChild parameters
** which are assumed zero.  Other than that, the two routines are the
** same.
**
** Fixes or enhancements to this routine should be reflected in
** insertCellFast()!
*/
static int insertCell(
  MemPage *pPage,   /* Page into which we are copying */
  int i,            /* New cell becomes the i-th cell of the page */
  u8 *pCell,        /* Content of the new cell */
  int sz,           /* Bytes of content in pCell */
  u8 *pTemp,        /* Temp storage space for pCell, if needed */

  assert( MX_CELL(pPage->pBt)<=10921 );
  assert( pPage->nCell<=MX_CELL(pPage->pBt) || CORRUPT_DB );
  assert( pPage->nOverflow<=ArraySize(pPage->apOvfl) );
  assert( ArraySize(pPage->apOvfl)==ArraySize(pPage->aiOvfl) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( sz==pPage->xCellSize(pPage, pCell) || CORRUPT_DB );
  assert( pPage->nFree>=0 );
  assert( iChild>0 );
  if( pPage->nOverflow || sz+2>pPage->nFree ){
    if( pTemp ){
      memcpy(pTemp, pCell, sz);
      pCell = pTemp;
    }

    put4byte(pCell, iChild);
    j = pPage->nOverflow++;
    /* Comparison against ArraySize-1 since we hold back one extra slot
    ** as a contingency.  In other words, never need more than 3 overflow
    ** slots but 4 are allocated, just to be safe. */
    assert( j < ArraySize(pPage->apOvfl)-1 );
    pPage->apOvfl[j] = pCell;
    pPage->aiOvfl[j] = (u16)i;

    /* When multiple overflows occur, they are always sequential and in
    ** sorted order.  This invariants arise because multiple overflows can
    ** only occur when inserting divider cells into the parent page during
    ** balancing, and the dividers are adjacent and sorted.
    */
    assert( j==0 || pPage->aiOvfl[j-1]<(u16)i ); /* Overflows in sorted order */
    assert( j==0 || i==pPage->aiOvfl[j-1]+1 );   /* Overflows are sequential */
  }else{
    int rc = sqlite3PagerWrite(pPage->pDbPage);
    if( NEVER(rc!=SQLITE_OK) ){
      return rc;
    }
    assert( sqlite3PagerIswriteable(pPage->pDbPage) );
    data = pPage->aData;
    assert( &data[pPage->cellOffset]==pPage->aCellIdx );
    rc = allocateSpace(pPage, sz, &idx);
    if( rc ){ return rc; }
    /* The allocateSpace() routine guarantees the following properties
    ** if it returns successfully */
    assert( idx >= 0 );
    assert( idx >= pPage->cellOffset+2*pPage->nCell+2 || CORRUPT_DB );
    assert( idx+sz <= (int)pPage->pBt->usableSize );
    pPage->nFree -= (u16)(2 + sz);
    /* In a corrupt database where an entry in the cell index section of
    ** a btree page has a value of 3 or less, the pCell value might point
    ** as many as 4 bytes in front of the start of the aData buffer for
    ** the source page.  Make sure this does not cause problems by not
    ** reading the first 4 bytes */
    memcpy(&data[idx+4], pCell+4, sz-4);
    put4byte(&data[idx], iChild);
    pIns = pPage->aCellIdx + i*2;
    memmove(pIns+2, pIns, 2*(pPage->nCell - i));
    put2byte(pIns, idx);
    pPage->nCell++;
    /* increment the cell count */
    if( (++data[pPage->hdrOffset+4])==0 ) data[pPage->hdrOffset+3]++;
    assert( get2byte(&data[pPage->hdrOffset+3])==pPage->nCell || CORRUPT_DB );
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pPage->pBt->autoVacuum ){
      int rc2 = SQLITE_OK;
      /* The cell may contain a pointer to an overflow page. If so, write
      ** the entry for the overflow page into the pointer map.
      */
      ptrmapPutOvflPtr(pPage, pPage, pCell, &rc2);
      if( rc2 ) return rc2;
    }
#endif
  }
  return SQLITE_OK;
}

/*
** This variant of insertCell() assumes that the pTemp and iChild
** parameters are both zero.  Use this variant in sqlite3BtreeInsert()
** for performance improvement, and also so that this variant is only
** called from that one place, and is thus inlined, and thus runs must
** faster.
**
** Fixes or enhancements to this routine should be reflected into
** the insertCell() routine.
*/
static int insertCellFast(
  MemPage *pPage,   /* Page into which we are copying */
  int i,            /* New cell becomes the i-th cell of the page */
  u8 *pCell,        /* Content of the new cell */
  int sz            /* Bytes of content in pCell */
){
  int idx = 0;      /* Where to write new cell content in data[] */
  int j;            /* Loop counter */
  u8 *data;         /* The content of the whole page */
  u8 *pIns;         /* The point in pPage->aCellIdx[] where no cell inserted */

  assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
  assert( MX_CELL(pPage->pBt)<=10921 );
  assert( pPage->nCell<=MX_CELL(pPage->pBt) || CORRUPT_DB );
  assert( pPage->nOverflow<=ArraySize(pPage->apOvfl) );
  assert( ArraySize(pPage->apOvfl)==ArraySize(pPage->aiOvfl) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( sz==pPage->xCellSize(pPage, pCell) || CORRUPT_DB );
  assert( pPage->nFree>=0 );
  assert( pPage->nOverflow==0 );
  if( sz+2>pPage->nFree ){
    j = pPage->nOverflow++;
    /* Comparison against ArraySize-1 since we hold back one extra slot
    ** as a contingency.  In other words, never need more than 3 overflow
    ** slots but 4 are allocated, just to be safe. */
    assert( j < ArraySize(pPage->apOvfl)-1 );
    pPage->apOvfl[j] = pCell;
    pPage->aiOvfl[j] = (u16)i;

    if( rc ){ return rc; }
    /* The allocateSpace() routine guarantees the following properties
    ** if it returns successfully */
    assert( idx >= 0 );
    assert( idx >= pPage->cellOffset+2*pPage->nCell+2 || CORRUPT_DB );
    assert( idx+sz <= (int)pPage->pBt->usableSize );
    pPage->nFree -= (u16)(2 + sz);









    memcpy(&data[idx], pCell, sz);

    pIns = pPage->aCellIdx + i*2;
    memmove(pIns+2, pIns, 2*(pPage->nCell - i));
    put2byte(pIns, idx);
    pPage->nCell++;
    /* increment the cell count */
    if( (++data[pPage->hdrOffset+4])==0 ) data[pPage->hdrOffset+3]++;
    assert( get2byte(&data[pPage->hdrOffset+3])==pPage->nCell || CORRUPT_DB );

  u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
  u8 *pData;
  int k;                          /* Current slot in pCArray->apEnd[] */
  u8 *pSrcEnd;                    /* Current pCArray->apEnd[k] value */

  assert( i<iEnd );
  j = get2byte(&aData[hdr+5]);
  if( NEVER(j>(u32)usableSize) ){ j = 0; }
  memcpy(&pTmp[j], &aData[j], usableSize - j);

  for(k=0; pCArray->ixNx[k]<=i && ALWAYS(k<NB*2); k++){}
  pSrcEnd = pCArray->apEnd[k];

  pData = pEnd;
  while( 1/*exit by break*/ ){

  int nCell,                      /* Cells to delete */
  CellArray *pCArray              /* Array of cells */
){
  u8 * const aData = pPg->aData;
  u8 * const pEnd = &aData[pPg->pBt->usableSize];
  u8 * const pStart = &aData[pPg->hdrOffset + 8 + pPg->childPtrSize];
  int nRet = 0;
  int i, j;
  int iEnd = iFirst + nCell;
  int nFree = 0;
  int aOfst[10];
  int aAfter[10];

  for(i=iFirst; i<iEnd; i++){
    u8 *pCell = pCArray->apCell[i];
    if( SQLITE_WITHIN(pCell, pStart, pEnd) ){
      int sz;
      int iAfter;
      int iOfst;
      /* No need to use cachedCellSize() here.  The sizes of all cells that
      ** are to be freed have already been computing while deciding which
      ** cells need freeing */
      sz = pCArray->szCell[i];  assert( sz>0 );
      iOfst = (u16)(pCell - aData);
      iAfter = iOfst+sz;
      for(j=0; j<nFree; j++){
        if( aOfst[j]==iAfter ){
          aOfst[j] = iOfst;
          break;
        }else if( aAfter[j]==iOfst ){
          aAfter[j] = iAfter;
          break;
        }
      }
      if( j>=nFree ){
        if( nFree>=(int)(sizeof(aOfst)/sizeof(aOfst[0])) ){
          for(j=0; j<nFree; j++){
            freeSpace(pPg, aOfst[j], aAfter[j]-aOfst[j]);
          }

          nFree = 0;


        }



        aOfst[nFree] = iOfst;
        aAfter[nFree] = iAfter;
        if( &aData[iAfter]>pEnd ) return 0;
        nFree++;
      }
      nRet++;
    }
  }
  for(j=0; j<nFree; j++){

    freeSpace(pPg, aOfst[j], aAfter[j]-aOfst[j]);
  }
  return nRet;
}

/*
** pCArray contains pointers to and sizes of all cells in the page being
** balanced.  The current page, pPg, has pPg->nCell cells starting with

  }
  if( iNewEnd < iOldEnd ){
    int nTail = pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);
    assert( nCell>=nTail );
    nCell -= nTail;
  }

  pData = &aData[get2byte(&aData[hdr+5])];
  if( pData<pBegin ) goto editpage_fail;
  if( NEVER(pData>pPg->aDataEnd) ) goto editpage_fail;

  /* Add cells to the start of the page */
  if( iNew<iOld ){
    int nAdd = MIN(nNew,iOld-iNew);
    assert( (iOld-iNew)<nNew || nCell==0 || CORRUPT_DB );
    assert( nAdd>=0 );
    pCellptr = pPg->aCellIdx;

  ** must be true:
  **    (1) We found one or more cells (cntNew[0])>0), or
  **    (2) pPage is a virtual root page.  A virtual root page is when
  **        the real root page is page 1 and we are the only child of
  **        that page.
  */
  assert( cntNew[0]>0 || (pParent->pgno==1 && pParent->nCell==0) || CORRUPT_DB);
  TRACE(("BALANCE: old: %u(nc=%u) %u(nc=%u) %u(nc=%u)\n",
    apOld[0]->pgno, apOld[0]->nCell,
    nOld>=2 ? apOld[1]->pgno : 0, nOld>=2 ? apOld[1]->nCell : 0,
    nOld>=3 ? apOld[2]->pgno : 0, nOld>=3 ? apOld[2]->nCell : 0
  ));

  /*
  ** Allocate k new pages.  Reuse old pages where possible.

      sqlite3PagerRekey(apNew[iB]->pDbPage, pgnoA, fgA);
      sqlite3PagerRekey(apNew[i]->pDbPage, pgnoB, fgB);
      apNew[i]->pgno = pgnoB;
      apNew[iB]->pgno = pgnoA;
    }
  }

  TRACE(("BALANCE: new: %u(%u nc=%u) %u(%u nc=%u) %u(%u nc=%u) "
         "%u(%u nc=%u) %u(%u nc=%u)\n",
    apNew[0]->pgno, szNew[0], cntNew[0],
    nNew>=2 ? apNew[1]->pgno : 0, nNew>=2 ? szNew[1] : 0,
    nNew>=2 ? cntNew[1] - cntNew[0] - !leafData : 0,
    nNew>=3 ? apNew[2]->pgno : 0, nNew>=3 ? szNew[2] : 0,
    nNew>=3 ? cntNew[2] - cntNew[1] - !leafData : 0,
    nNew>=4 ? apNew[3]->pgno : 0, nNew>=4 ? szNew[3] : 0,
    nNew>=4 ? cntNew[3] - cntNew[2] - !leafData : 0,

    for(i=0; i<nNew; i++){
      u32 key = get4byte(&apNew[i]->aData[8]);
      ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i]->pgno, &rc);
    }
  }

  assert( pParent->isInit );
  TRACE(("BALANCE: finished: old=%u new=%u cells=%u\n",
          nOld, nNew, b.nCell));

  /* Free any old pages that were not reused as new pages.
  */
  for(i=nNew; i<nOld; i++){
    freePage(apOld[i], &rc);
  }

    releasePage(pChild);
    return rc;
  }
  assert( sqlite3PagerIswriteable(pChild->pDbPage) );
  assert( sqlite3PagerIswriteable(pRoot->pDbPage) );
  assert( pChild->nCell==pRoot->nCell || CORRUPT_DB );

  TRACE(("BALANCE: copy root %u into %u\n", pRoot->pgno, pChild->pgno));

  /* Copy the overflow cells from pRoot to pChild */
  memcpy(pChild->aiOvfl, pRoot->aiOvfl,
         pRoot->nOverflow*sizeof(pRoot->aiOvfl[0]));
  memcpy(pChild->apOvfl, pRoot->apOvfl,
         pRoot->nOverflow*sizeof(pRoot->apOvfl[0]));
  pChild->nOverflow = pRoot->nOverflow;

        x2.nData = pX->nKey;
        x2.nZero = 0;
        return btreeOverwriteCell(pCur, &x2);
      }
    }
  }
  assert( pCur->eState==CURSOR_VALID
       || (pCur->eState==CURSOR_INVALID && loc) || CORRUPT_DB );

  pPage = pCur->pPage;
  assert( pPage->intKey || pX->nKey>=0 || (flags & BTREE_PREFORMAT) );
  assert( pPage->leaf || !pPage->intKey );
  if( pPage->nFree<0 ){
    if( NEVER(pCur->eState>CURSOR_INVALID) ){
     /* ^^^^^--- due to the moveToRoot() call above */
      rc = SQLITE_CORRUPT_BKPT;
    }else{
      rc = btreeComputeFreeSpace(pPage);
    }
    if( rc ) return rc;
  }

  TRACE(("INSERT: table=%u nkey=%lld ndata=%u page=%u %s\n",
          pCur->pgnoRoot, pX->nKey, pX->nData, pPage->pgno,
          loc==0 ? "overwrite" : "new entry"));
  assert( pPage->isInit || CORRUPT_DB );
  newCell = p->pBt->pTmpSpace;
  assert( newCell!=0 );
  assert( BTREE_PREFORMAT==OPFLAG_PREFORMAT );
  if( flags & BTREE_PREFORMAT ){

  }else{
    rc = fillInCell(pPage, newCell, pX, &szNew);
    if( rc ) goto end_insert;
  }
  assert( szNew==pPage->xCellSize(pPage, newCell) );
  assert( szNew <= MX_CELL_SIZE(p->pBt) );
  idx = pCur->ix;
  pCur->info.nSize = 0;
  if( loc==0 ){
    CellInfo info;
    assert( idx>=0 );
    if( idx>=pPage->nCell ){
      return SQLITE_CORRUPT_BKPT;
    }
    rc = sqlite3PagerWrite(pPage->pDbPage);

  }else if( loc<0 && pPage->nCell>0 ){
    assert( pPage->leaf );
    idx = ++pCur->ix;
    pCur->curFlags &= ~BTCF_ValidNKey;
  }else{
    assert( pPage->leaf );
  }
  rc = insertCellFast(pPage, idx, newCell, szNew);
  assert( pPage->nOverflow==0 || rc==SQLITE_OK );
  assert( rc!=SQLITE_OK || pPage->nCell>0 || pPage->nOverflow>0 );

  /* If no error has occurred and pPage has an overflow cell, call balance()
  ** to redistribute the cells within the tree. Since balance() may move
  ** the cursor, zero the BtCursor.info.nSize and BTCF_ValidNKey
  ** variables.

  ** happen while processing an "INSERT INTO ... SELECT" statement), it
  ** is advantageous to leave the cursor pointing to the last entry in
  ** the b-tree if possible. If the cursor is left pointing to the last
  ** entry in the table, and the next row inserted has an integer key
  ** larger than the largest existing key, it is possible to insert the
  ** row without seeking the cursor. This can be a big performance boost.
  */

  if( pPage->nOverflow ){
    assert( rc==SQLITE_OK );
    pCur->curFlags &= ~(BTCF_ValidNKey);
    rc = balance(pCur);

    /* Must make sure nOverflow is reset to zero even if the balance()
    ** fails. Internal data structure corruption will result otherwise.

  pPage = pCur->pPage;
  if( pPage->nCell<=iCellIdx ){
    return SQLITE_CORRUPT_BKPT;
  }
  pCell = findCell(pPage, iCellIdx);
  if( pPage->nFree<0 && btreeComputeFreeSpace(pPage) ){
    return SQLITE_CORRUPT_BKPT;
  }
  if( pCell<&pPage->aCellIdx[pPage->nCell] ){
    return SQLITE_CORRUPT_BKPT;
  }

  /* If the BTREE_SAVEPOSITION bit is on, then the cursor position must
  ** be preserved following this delete operation. If the current delete
  ** will cause a b-tree rebalance, then this is done by saving the cursor
  ** key and leaving the cursor in CURSOR_REQUIRESEEK state before
  ** returning.

  pCheck->mxErr--;
  pCheck->nErr++;
  va_start(ap, zFormat);
  if( pCheck->errMsg.nChar ){
    sqlite3_str_append(&pCheck->errMsg, "\n", 1);
  }
  if( pCheck->zPfx ){
    sqlite3_str_appendf(&pCheck->errMsg, pCheck->zPfx,
                        pCheck->v0, pCheck->v1, pCheck->v2);
  }
  sqlite3_str_vappendf(&pCheck->errMsg, zFormat, ap);
  va_end(ap);
  if( pCheck->errMsg.accError==SQLITE_NOMEM ){
    checkOom(pCheck);
  }
}

** 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){
  if( iPage>pCheck->nPage || iPage==0 ){
    checkAppendMsg(pCheck, "invalid page number %u", iPage);
    return 1;
  }
  if( getPageReferenced(pCheck, iPage) ){
    checkAppendMsg(pCheck, "2nd reference to page %u", iPage);
    return 1;
  }
  setPageReferenced(pCheck, iPage);
  return 0;
}

#ifndef SQLITE_OMIT_AUTOVACUUM

  int rc;
  u8 ePtrmapType;
  Pgno iPtrmapParent;

  rc = ptrmapGet(pCheck->pBt, iChild, &ePtrmapType, &iPtrmapParent);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ) checkOom(pCheck);
    checkAppendMsg(pCheck, "Failed to read ptrmap key=%u", iChild);
    return;
  }

  if( ePtrmapType!=eType || iPtrmapParent!=iParent ){
    checkAppendMsg(pCheck,
      "Bad ptr map entry key=%u expected=(%u,%u) got=(%u,%u)",
      iChild, eType, iParent, ePtrmapType, iPtrmapParent);
  }
}
#endif

/*
** Check the integrity of the freelist or of an overflow page list.

  int nErrAtStart = pCheck->nErr;
  while( iPage!=0 && pCheck->mxErr ){
    DbPage *pOvflPage;
    unsigned char *pOvflData;
    if( checkRef(pCheck, iPage) ) break;
    N--;
    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
      checkAppendMsg(pCheck, "failed to get page %u", iPage);
      break;
    }
    pOvflData = (unsigned char *)sqlite3PagerGetData(pOvflPage);
    if( isFreeList ){
      u32 n = (u32)get4byte(&pOvflData[4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
      if( pCheck->pBt->autoVacuum ){
        checkPtrmap(pCheck, iPage, PTRMAP_FREEPAGE, 0);
      }
#endif
      if( n>pCheck->pBt->usableSize/4-2 ){
        checkAppendMsg(pCheck,
           "freelist leaf count too big on page %u", iPage);
        N--;
      }else{
        for(i=0; i<(int)n; i++){
          Pgno iFreePage = get4byte(&pOvflData[8+i*4]);
#ifndef SQLITE_OMIT_AUTOVACUUM
          if( pCheck->pBt->autoVacuum ){
            checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0);

    }
#endif
    iPage = get4byte(pOvflData);
    sqlite3PagerUnref(pOvflPage);
  }
  if( N && nErrAtStart==pCheck->nErr ){
    checkAppendMsg(pCheck,
      "%s is %u but should be %u",
      isFreeList ? "size" : "overflow list length",
      expected-N, expected);
  }
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/*

  */
  checkProgress(pCheck);
  if( pCheck->mxErr==0 ) goto end_of_check;
  pBt = pCheck->pBt;
  usableSize = pBt->usableSize;
  if( iPage==0 ) return 0;
  if( checkRef(pCheck, iPage) ) return 0;
  pCheck->zPfx = "Tree %u page %u: ";
  pCheck->v0 = pCheck->v1 = iPage;
  if( (rc = btreeGetPage(pBt, iPage, &pPage, 0))!=0 ){
    checkAppendMsg(pCheck,
       "unable to get the page. error code=%d", rc);
    goto end_of_check;
  }

  /* Clear MemPage.isInit to make sure the corruption detection code in

    checkAppendMsg(pCheck, "free space corruption", rc);
    goto end_of_check;
  }
  data = pPage->aData;
  hdr = pPage->hdrOffset;

  /* Set up for cell analysis */
  pCheck->zPfx = "Tree %u page %u cell %u: ";
  contentOffset = get2byteNotZero(&data[hdr+5]);
  assert( contentOffset<=usableSize );  /* Enforced by btreeInitPage() */

  /* EVIDENCE-OF: R-37002-32774 The two-byte integer at offset 3 gives the
  ** number of cells on the page. */
  nCell = get2byte(&data[hdr+3]);
  assert( pPage->nCell==nCell );

  /* EVIDENCE-OF: R-23882-45353 The cell pointer array of a b-tree page
  ** immediately follows the b-tree page header. */
  cellStart = hdr + 12 - 4*pPage->leaf;
  assert( pPage->aCellIdx==&data[cellStart] );
  pCellIdx = &data[cellStart + 2*(nCell-1)];

  if( !pPage->leaf ){
    /* Analyze the right-child page of internal pages */
    pgno = get4byte(&data[hdr+8]);
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum ){
      pCheck->zPfx = "Tree %u page %u right child: ";
      checkPtrmap(pCheck, pgno, PTRMAP_BTREE, iPage);
    }
#endif
    depth = checkTreePage(pCheck, pgno, &maxKey, maxKey);
    keyCanBeEqual = 0;
  }else{
    /* For leaf pages, the coverage check will occur in the same loop

    /* Check cell size */
    pCheck->v2 = i;
    assert( pCellIdx==&data[cellStart + i*2] );
    pc = get2byteAligned(pCellIdx);
    pCellIdx -= 2;
    if( pc<contentOffset || pc>usableSize-4 ){
      checkAppendMsg(pCheck, "Offset %u out of range %u..%u",
                             pc, contentOffset, usableSize-4);
      doCoverageCheck = 0;
      continue;
    }
    pCell = &data[pc];
    pPage->xParseCell(pPage, pCell, &info);
    if( pc+info.nSize>usableSize ){

    /* EVIDENCE-OF: R-43263-13491 The total number of bytes in all fragments
    ** is stored in the fifth field of the b-tree page header.
    ** EVIDENCE-OF: R-07161-27322 The one-byte integer at offset 7 gives the
    ** number of fragmented free bytes within the cell content area.
    */
    if( heap[0]==0 && nFrag!=data[hdr+7] ){
      checkAppendMsg(pCheck,
          "Fragmentation of %u bytes reported as %u on page %u",
          nFrag, data[hdr+7], iPage);
    }
  }

end_of_check:
  if( !doCoverageCheck ) pPage->isInit = savedIsInit;
  releasePage(pPage);

  i = PENDING_BYTE_PAGE(pBt);
  if( i<=sCheck.nPage ) setPageReferenced(&sCheck, i);

  /* Check the integrity of the freelist
  */
  if( bCkFreelist ){
    sCheck.zPfx = "Freelist: ";
    checkList(&sCheck, 1, get4byte(&pBt->pPage1->aData[32]),
              get4byte(&pBt->pPage1->aData[36]));
    sCheck.zPfx = 0;
  }

  /* Check all the tables.
  */
#ifndef SQLITE_OMIT_AUTOVACUUM
  if( !bPartial ){
    if( pBt->autoVacuum ){
      Pgno mx = 0;
      Pgno mxInHdr;
      for(i=0; (int)i<nRoot; i++) if( mx<aRoot[i] ) mx = aRoot[i];
      mxInHdr = get4byte(&pBt->pPage1->aData[52]);
      if( mx!=mxInHdr ){
        checkAppendMsg(&sCheck,
          "max rootpage (%u) disagrees with header (%u)",
          mx, mxInHdr
        );
      }
    }else if( get4byte(&pBt->pPage1->aData[64])!=0 ){
      checkAppendMsg(&sCheck,
        "incremental_vacuum enabled with a max rootpage of zero"
      );

  /* Make sure every page in the file is referenced
  */
  if( !bPartial ){
    for(i=1; i<=sCheck.nPage && sCheck.mxErr; i++){
#ifdef SQLITE_OMIT_AUTOVACUUM
      if( getPageReferenced(&sCheck, i)==0 ){
        checkAppendMsg(&sCheck, "Page %u: never used", i);
      }
#else
      /* If the database supports auto-vacuum, make sure no tables contain
      ** references to pointer-map pages.
      */
      if( getPageReferenced(&sCheck, i)==0 &&
         (PTRMAP_PAGENO(pBt, i)!=i || !pBt->autoVacuum) ){
        checkAppendMsg(&sCheck, "Page %u: never used", i);
      }
      if( getPageReferenced(&sCheck, i)!=0 &&
         (PTRMAP_PAGENO(pBt, i)==i && pBt->autoVacuum) ){
        checkAppendMsg(&sCheck, "Page %u: pointer map referenced", i);
      }
#endif
    }
  }

  /* Clean  up and report errors.
  */

  i64 iOff;

  assert( sqlite3BtreeGetReserveNoMutex(p->pSrc)>=0 );
  assert( p->bDestLocked );
  assert( !isFatalError(p->rc) );
  assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
  assert( zSrcData );




  assert( nSrcPgsz==nDestPgsz || sqlite3PagerIsMemdb(pDestPager)==0 );



  /* This loop runs once for each destination page spanned by the source
  ** page. For each iteration, variable iOff is set to the byte offset
  ** of the destination page.
  */
  for(iOff=iEnd-(i64)nSrcPgsz; rc==SQLITE_OK && iOff<iEnd; iOff+=nDestPgsz){
    DbPage *pDestPg = 0;

    }

    /* Do not allow backup if the destination database is in WAL mode
    ** and the page sizes are different between source and destination */
    pgszSrc = sqlite3BtreeGetPageSize(p->pSrc);
    pgszDest = sqlite3BtreeGetPageSize(p->pDest);
    destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest));
    if( SQLITE_OK==rc
     && (destMode==PAGER_JOURNALMODE_WAL || sqlite3PagerIsMemdb(pDestPager))
     && pgszSrc!=pgszDest
    ){
      rc = SQLITE_READONLY;
    }

    /* Now that there is a read-lock on the source database, query the
    ** source pager for the number of pages in the database.
    */
    nSrcPage = (int)sqlite3BtreeLastPage(p->pSrc);

*/
SQLITE_PRIVATE int sqlite3VdbeMemValidStrRep(Mem *p){
  Mem tmp;
  char zBuf[100];
  char *z;
  int i, j, incr;
  if( (p->flags & MEM_Str)==0 ) return 1;
  if( p->db && p->db->mallocFailed ) return 1;
  if( p->flags & MEM_Term ){
    /* Insure that the string is properly zero-terminated.  Pay particular
    ** attention to the case where p->n is odd */
    if( p->szMalloc>0 && p->z==p->zMalloc ){
      assert( p->enc==SQLITE_UTF8 || p->szMalloc >= ((p->n+1)&~1)+2 );
      assert( p->enc!=SQLITE_UTF8 || p->szMalloc >= p->n+1 );
    }

  if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
    pMem->enc = 0;
    return SQLITE_NOMEM_BKPT;
  }

  vdbeMemRenderNum(nByte, pMem->z, pMem);
  assert( pMem->z!=0 );
  assert( pMem->n==(int)sqlite3Strlen30NN(pMem->z) );
  pMem->enc = SQLITE_UTF8;
  pMem->flags |= MEM_Str|MEM_Term;
  if( bForce ) pMem->flags &= ~(MEM_Int|MEM_Real|MEM_IntReal);
  sqlite3VdbeChangeEncoding(pMem, enc);
  return SQLITE_OK;
}

  assert( pCtx!=0 );
  assert( (p->flags & EP_TokenOnly)==0 );
  assert( ExprUseXList(p) );
  pList = p->x.pList;
  if( pList ) nVal = pList->nExpr;
  assert( !ExprHasProperty(p, EP_IntValue) );
  pFunc = sqlite3FindFunction(db, p->u.zToken, nVal, enc, 0);
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
  if( pFunc==0 ) return SQLITE_OK;
#endif
  assert( pFunc );
  if( (pFunc->funcFlags & (SQLITE_FUNC_CONSTANT|SQLITE_FUNC_SLOCHNG))==0
   || (pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)
  ){
    return SQLITE_OK;
  }

  pFunc->xSFunc(&ctx, nVal, apVal);
  if( ctx.isError ){
    rc = ctx.isError;
    sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));
  }else{
    sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
    assert( rc==SQLITE_OK );




    rc = sqlite3VdbeChangeEncoding(pVal, enc);
    if( NEVER(rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal)) ){
      rc = SQLITE_TOOBIG;
      pCtx->pParse->nErr++;
    }

  }

 value_from_function_out:
  if( rc!=SQLITE_OK ){
    pVal = 0;
    pCtx->pParse->rc = rc;
  }

  if( op==TK_CAST ){
    u8 aff;
    assert( !ExprHasProperty(pExpr, EP_IntValue) );
    aff = sqlite3AffinityType(pExpr->u.zToken,0);
    rc = valueFromExpr(db, pExpr->pLeft, enc, aff, ppVal, pCtx);
    testcase( rc!=SQLITE_OK );
    if( *ppVal ){
#ifdef SQLITE_ENABLE_STAT4
      rc = ExpandBlob(*ppVal);
#else
      /* zero-blobs only come from functions, not literal values.  And
      ** functions are only processed under STAT4 */
      assert( (ppVal[0][0].flags & MEM_Zero)==0 );
#endif
      sqlite3VdbeMemCast(*ppVal, aff, enc);
      sqlite3ValueApplyAffinity(*ppVal, affinity, enc);
    }
    return rc;
  }

  /* Handle negative integers in a single step.  This is needed in the

** Add a new OP_Explain opcode.
**
** If the bPush flag is true, then make this opcode the parent for
** subsequent Explains until sqlite3VdbeExplainPop() is called.
*/
SQLITE_PRIVATE int sqlite3VdbeExplain(Parse *pParse, u8 bPush, const char *zFmt, ...){
  int addr = 0;
#if !defined(SQLITE_DEBUG)
  /* Always include the OP_Explain opcodes if SQLITE_DEBUG is defined.
  ** But omit them (for performance) during production builds */
  if( pParse->explain==2 || IS_STMT_SCANSTATUS(pParse->db) )
#endif
  {
    char *zMsg;
    Vdbe *v;
    va_list ap;
    int iThis;
    va_start(ap, zFmt);

** coordinated with changes to mkopcodeh.tcl.
*/
static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
  int nMaxArgs = *pMaxFuncArgs;
  Op *pOp;
  Parse *pParse = p->pParse;
  int *aLabel = pParse->aLabel;

  assert( pParse->db->mallocFailed==0 ); /* tag-20230419-1 */
  p->readOnly = 1;
  p->bIsReader = 0;
  pOp = &p->aOp[p->nOp-1];
  assert( p->aOp[0].opcode==OP_Init );
  while( 1 /* Loop termates when it reaches the OP_Init opcode */ ){
    /* Only JUMP opcodes and the short list of special opcodes in the switch
    ** below need to be considered.  The mkopcodeh.tcl generator script groups

        default: {
          if( pOp->p2<0 ){
            /* The mkopcodeh.tcl script has so arranged things that the only
            ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to
            ** have non-negative values for P2. */
            assert( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 );
            assert( ADDR(pOp->p2)<-pParse->nLabel );
            assert( aLabel!=0 );  /* True because of tag-20230419-1 */
            pOp->p2 = aLabel[ADDR(pOp->p2)];
          }
          break;
        }
      }
      /* The mkopcodeh.tcl script has so arranged things that the only
      ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to

  Vdbe *p,                        /* VM to add scanstatus() to */
  int addrExplain,                /* Address of OP_Explain (or 0) */
  int addrLoop,                   /* Address of loop counter */
  int addrVisit,                  /* Address of rows visited counter */
  LogEst nEst,                    /* Estimated number of output rows */
  const char *zName               /* Name of table or index being scanned */
){
  if( IS_STMT_SCANSTATUS(p->db) ){
    sqlite3_int64 nByte = (p->nScan+1) * sizeof(ScanStatus);
    ScanStatus *aNew;
    aNew = (ScanStatus*)sqlite3DbRealloc(p->db, p->aScan, nByte);
    if( aNew ){
      ScanStatus *pNew = &aNew[p->nScan++];
      memset(pNew, 0, sizeof(ScanStatus));
      pNew->addrExplain = addrExplain;
      pNew->addrLoop = addrLoop;
      pNew->addrVisit = addrVisit;
      pNew->nEst = nEst;
      pNew->zName = sqlite3DbStrDup(p->db, zName);
      p->aScan = aNew;
    }
  }
}

/*
** Add the range of instructions from addrStart to addrEnd (inclusive) to
** the set of those corresponding to the sqlite3_stmt_scanstatus() counters
** associated with the OP_Explain instruction at addrExplain. The
** sum of the sqlite3Hwtime() values for each of these instructions
** will be returned for SQLITE_SCANSTAT_NCYCLE requests.
*/
SQLITE_PRIVATE void sqlite3VdbeScanStatusRange(
  Vdbe *p,
  int addrExplain,
  int addrStart,
  int addrEnd
){
  if( IS_STMT_SCANSTATUS(p->db) ){
    ScanStatus *pScan = 0;
    int ii;
    for(ii=p->nScan-1; ii>=0; ii--){
      pScan = &p->aScan[ii];
      if( pScan->addrExplain==addrExplain ) break;
      pScan = 0;
    }
    if( pScan ){
      if( addrEnd<0 ) addrEnd = sqlite3VdbeCurrentAddr(p)-1;
      for(ii=0; ii<ArraySize(pScan->aAddrRange); ii+=2){
        if( pScan->aAddrRange[ii]==0 ){
          pScan->aAddrRange[ii] = addrStart;
          pScan->aAddrRange[ii+1] = addrEnd;
          break;
        }
      }
    }
  }
}

/*
** Set the addresses for the SQLITE_SCANSTAT_NLOOP and SQLITE_SCANSTAT_NROW
** counters for the query element associated with the OP_Explain at
** addrExplain.
*/
SQLITE_PRIVATE void sqlite3VdbeScanStatusCounters(
  Vdbe *p,
  int addrExplain,
  int addrLoop,
  int addrVisit
){
  if( IS_STMT_SCANSTATUS(p->db) ){
    ScanStatus *pScan = 0;
    int ii;
    for(ii=p->nScan-1; ii>=0; ii--){
      pScan = &p->aScan[ii];
      if( pScan->addrExplain==addrExplain ) break;
      pScan = 0;
    }
    if( pScan ){
      pScan->addrLoop = addrLoop;
      pScan->addrVisit = addrVisit;
    }
  }
}
#endif /* defined(SQLITE_ENABLE_STMT_SCANSTATUS) */


/*
** Change the value of the opcode, or P1, P2, P3, or P5 operands
** for a specific instruction.
*/
SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe *p, int addr, u8 iNewOpcode){

  }else{
    return &p->aOp[addr];
  }
}

/* Return the most recently added opcode
*/
SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetLastOp(Vdbe *p){
  return sqlite3VdbeGetOp(p, p->nOp - 1);
}

#if defined(SQLITE_ENABLE_EXPLAIN_COMMENTS)
/*
** Return an integer value for one of the parameters to the opcode pOp
** determined by character c.

          p->nChange = 0;
        }else{
          db->nDeferredCons = 0;
          db->nDeferredImmCons = 0;
          db->flags &= ~(u64)SQLITE_DeferFKs;
          sqlite3CommitInternalChanges(db);
        }
      }else if( p->rc==SQLITE_SCHEMA && db->nVdbeActive>1 ){
        p->nChange = 0;
      }else{
        sqlite3RollbackAll(db, SQLITE_OK);
        p->nChange = 0;
      }
      db->nStatement = 0;
    }else if( eStatementOp==0 ){
      if( p->rc==SQLITE_OK || p->errorAction==OE_Fail ){

    if( p->pFree ) sqlite3DbNNFreeNN(db, p->pFree);
  }
  vdbeFreeOpArray(db, p->aOp, p->nOp);
  if( p->zSql ) sqlite3DbNNFreeNN(db, p->zSql);
#ifdef SQLITE_ENABLE_NORMALIZE
  sqlite3DbFree(db, p->zNormSql);
  {
    DblquoteStr *pThis, *pNxt;
    for(pThis=p->pDblStr; pThis; pThis=pNxt){
      pNxt = pThis->pNextStr;
      sqlite3DbFree(db, pThis);
    }
  }
#endif
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  {
    int i;

    sqlite3_result_error(pCtx, zMsg, -1);
    sqlite3_free(zMsg);
    return 0;
  }
  return 1;
}

#if defined(SQLITE_ENABLE_CURSOR_HINTS) && defined(SQLITE_DEBUG)
/*
** This Walker callback is used to help verify that calls to
** sqlite3BtreeCursorHint() with opcode BTREE_HINT_RANGE have
** byte-code register values correctly initialized.
*/
SQLITE_PRIVATE int sqlite3CursorRangeHintExprCheck(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_REGISTER ){
    assert( (pWalker->u.aMem[pExpr->iTable].flags & MEM_Undefined)==0 );
  }
  return WRC_Continue;
}
#endif /* SQLITE_ENABLE_CURSOR_HINTS && SQLITE_DEBUG */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
** in memory obtained from sqlite3DbMalloc).
*/
SQLITE_PRIVATE void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){

  int iBlobWrite
){
  sqlite3 *db = v->db;
  i64 iKey2;
  PreUpdate preupdate;
  const char *zTbl = pTab->zName;
  static const u8 fakeSortOrder = 0;
#ifdef SQLITE_DEBUG
  int nRealCol;
  if( pTab->tabFlags & TF_WithoutRowid ){
    nRealCol = sqlite3PrimaryKeyIndex(pTab)->nColumn;
  }else if( pTab->tabFlags & TF_HasVirtual ){
    nRealCol = pTab->nNVCol;
  }else{
    nRealCol = pTab->nCol;
  }
#endif

  assert( db->pPreUpdate==0 );
  memset(&preupdate, 0, sizeof(PreUpdate));
  if( HasRowid(pTab)==0 ){
    iKey1 = iKey2 = 0;
    preupdate.pPk = sqlite3PrimaryKeyIndex(pTab);
  }else{
    if( op==SQLITE_UPDATE ){
      iKey2 = v->aMem[iReg].u.i;
    }else{
      iKey2 = iKey1;
    }
  }

  assert( pCsr!=0 );
  assert( pCsr->eCurType==CURTYPE_BTREE );
  assert( pCsr->nField==nRealCol
       || (pCsr->nField==nRealCol+1 && op==SQLITE_DELETE && iReg==-1)
  );

  preupdate.v = v;
  preupdate.pCsr = pCsr;
  preupdate.op = op;
  preupdate.iNewReg = iReg;
  preupdate.keyinfo.db = db;

     SQLITE_NULL,     /* 0x1b (not possible) */
     SQLITE_INTEGER,  /* 0x1c (not possible) */
     SQLITE_NULL,     /* 0x1d (not possible) */
     SQLITE_INTEGER,  /* 0x1e (not possible) */
     SQLITE_NULL,     /* 0x1f (not possible) */
     SQLITE_FLOAT,    /* 0x20 INTREAL */
     SQLITE_NULL,     /* 0x21 (not possible) */
     SQLITE_FLOAT,    /* 0x22 INTREAL + TEXT */
     SQLITE_NULL,     /* 0x23 (not possible) */
     SQLITE_FLOAT,    /* 0x24 (not possible) */
     SQLITE_NULL,     /* 0x25 (not possible) */
     SQLITE_FLOAT,    /* 0x26 (not possible) */
     SQLITE_NULL,     /* 0x27 (not possible) */
     SQLITE_FLOAT,    /* 0x28 (not possible) */
     SQLITE_NULL,     /* 0x29 (not possible) */

#endif
  ret = 0;
  p = (Vdbe *)pStmt;
  db = p->db;
  assert( db!=0 );
  n = sqlite3_column_count(pStmt);
  if( N<n && N>=0 ){
    u8 prior_mallocFailed = db->mallocFailed;
    N += useType*n;
    sqlite3_mutex_enter(db->mutex);

#ifndef SQLITE_OMIT_UTF16
    if( useUtf16 ){
      ret = sqlite3_value_text16((sqlite3_value*)&p->aColName[N]);
    }else
#endif
    {
      ret = sqlite3_value_text((sqlite3_value*)&p->aColName[N]);
    }
    /* A malloc may have failed inside of the _text() call. If this
    ** is the case, clear the mallocFailed flag and return NULL.
    */
    assert( db->mallocFailed==0 || db->mallocFailed==1 );
    if( db->mallocFailed > prior_mallocFailed ){
      sqlite3OomClear(db);
      ret = 0;
    }
    sqlite3_mutex_leave(db->mutex);
  }
  return ret;
}

  sqlite3_stmt *pStmt,            /* Prepared statement being queried */
  int iScan,                      /* Index of loop to report on */
  int iScanStatusOp,              /* Which metric to return */
  int flags,
  void *pOut                      /* OUT: Write the answer here */
){
  Vdbe *p = (Vdbe*)pStmt;
  VdbeOp *aOp = p->aOp;
  int nOp = p->nOp;
  ScanStatus *pScan = 0;
  int idx;

  if( p->pFrame ){
    VdbeFrame *pFrame;
    for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
    aOp = pFrame->aOp;
    nOp = pFrame->nOp;
  }

  if( iScan<0 ){
    int ii;
    if( iScanStatusOp==SQLITE_SCANSTAT_NCYCLE ){
      i64 res = 0;
      for(ii=0; ii<nOp; ii++){
        res += aOp[ii].nCycle;
      }
      *(i64*)pOut = res;
      return 0;
    }
    return 1;
  }
  if( flags & SQLITE_SCANSTAT_COMPLEX ){

    }
  }
  if( idx>=p->nScan ) return 1;

  switch( iScanStatusOp ){
    case SQLITE_SCANSTAT_NLOOP: {
      if( pScan->addrLoop>0 ){
        *(sqlite3_int64*)pOut = aOp[pScan->addrLoop].nExec;
      }else{
        *(sqlite3_int64*)pOut = -1;
      }
      break;
    }
    case SQLITE_SCANSTAT_NVISIT: {
      if( pScan->addrVisit>0 ){
        *(sqlite3_int64*)pOut = aOp[pScan->addrVisit].nExec;
      }else{
        *(sqlite3_int64*)pOut = -1;
      }
      break;
    }
    case SQLITE_SCANSTAT_EST: {
      double r = 1.0;

    }
    case SQLITE_SCANSTAT_NAME: {
      *(const char**)pOut = pScan->zName;
      break;
    }
    case SQLITE_SCANSTAT_EXPLAIN: {
      if( pScan->addrExplain ){
        *(const char**)pOut = aOp[ pScan->addrExplain ].p4.z;
      }else{
        *(const char**)pOut = 0;
      }
      break;
    }
    case SQLITE_SCANSTAT_SELECTID: {
      if( pScan->addrExplain ){
        *(int*)pOut = aOp[ pScan->addrExplain ].p1;
      }else{
        *(int*)pOut = -1;
      }
      break;
    }
    case SQLITE_SCANSTAT_PARENTID: {
      if( pScan->addrExplain ){
        *(int*)pOut = aOp[ pScan->addrExplain ].p2;
      }else{
        *(int*)pOut = -1;
      }
      break;
    }
    case SQLITE_SCANSTAT_NCYCLE: {
      i64 res = 0;
      if( pScan->aAddrRange[0]==0 ){
        res = -1;
      }else{
        int ii;
        for(ii=0; ii<ArraySize(pScan->aAddrRange); ii+=2){
          int iIns = pScan->aAddrRange[ii];
          int iEnd = pScan->aAddrRange[ii+1];
          if( iIns==0 ) break;
          if( iIns>0 ){
            while( iIns<=iEnd ){
              res += aOp[iIns].nCycle;
              iIns++;
            }
          }else{
            int iOp;
            for(iOp=0; iOp<nOp; iOp++){
              Op *pOp = &aOp[iOp];
              if( pOp->p1!=iEnd ) continue;
              if( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_NCYCLE)==0 ){
                continue;
              }
              res += aOp[iOp].nCycle;
            }
          }
        }
      }
      *(i64*)pOut = res;
      break;
    }

  for(i=pOp->p3, mx=i+pOp->p4.i; i<mx; i++){
    const Mem *p = &aMem[i];
    if( p->flags & (MEM_Int|MEM_IntReal) ){
      h += p->u.i;
    }else if( p->flags & MEM_Real ){
      h += sqlite3VdbeIntValue(p);
    }else if( p->flags & (MEM_Str|MEM_Blob) ){
      /* All strings have the same hash and all blobs have the same hash,
      ** though, at least, those hashes are different from each other and
      ** from NULL. */
      h += 4093 + (p->flags & (MEM_Str|MEM_Blob));
    }
  }
  return h;
}

/*
** Return the symbolic name for the data type of a pMem

  Mem *aMem = p->aMem;       /* Copy of p->aMem */
  Mem *pIn1 = 0;             /* 1st input operand */
  Mem *pIn2 = 0;             /* 2nd input operand */
  Mem *pIn3 = 0;             /* 3rd input operand */
  Mem *pOut = 0;             /* Output operand */
#if defined(SQLITE_ENABLE_STMT_SCANSTATUS) || defined(VDBE_PROFILE)
  u64 *pnCycle = 0;
  int bStmtScanStatus = IS_STMT_SCANSTATUS(db)!=0;
#endif
  /*** INSERT STACK UNION HERE ***/

  assert( p->eVdbeState==VDBE_RUN_STATE );  /* sqlite3_step() verifies this */
  if( DbMaskNonZero(p->lockMask) ){
    sqlite3VdbeEnter(p);
  }

  for(pOp=&aOp[p->pc]; 1; pOp++){
    /* Errors are detected by individual opcodes, with an immediate
    ** jumps to abort_due_to_error. */
    assert( rc==SQLITE_OK );

    assert( pOp>=aOp && pOp<&aOp[p->nOp]);
    nVmStep++;

#if defined(VDBE_PROFILE)
    pOp->nExec++;
    pnCycle = &pOp->nCycle;

    if( sqlite3NProfileCnt==0 ) *pnCycle -= sqlite3Hwtime();
#elif defined(SQLITE_ENABLE_STMT_SCANSTATUS)
    if( bStmtScanStatus ){
      pOp->nExec++;
      pnCycle = &pOp->nCycle;
      *pnCycle -= sqlite3Hwtime();
    }
#endif

    /* Only allow tracing if SQLITE_DEBUG is defined.
    */
#ifdef SQLITE_DEBUG
    if( db->flags & SQLITE_VdbeTrace ){
      sqlite3VdbePrintOp(stdout, (int)(pOp - aOp), pOp);

  assert( pOp[1].opcode==OP_Jump );
  break;
}

/* Opcode: Jump P1 P2 P3 * *
**
** Jump to the instruction at address P1, P2, or P3 depending on whether
** in the most recent OP_Compare instruction the P1 vector was less than,
** equal to, or greater than the P2 vector, respectively.
**
** This opcode must immediately follow an OP_Compare opcode.
*/
case OP_Jump: {             /* jump */
  assert( pOp>aOp && pOp[-1].opcode==OP_Compare );
  assert( iCompareIsInit );

** If P1 is -1, then P3 is a register number and the datatype is taken
** from the value in that register.
**
** P5 is a bitmask of data types.  SQLITE_INTEGER is the least significant
** (0x01) bit. SQLITE_FLOAT is the 0x02 bit. SQLITE_TEXT is 0x04.
** SQLITE_BLOB is 0x08.  SQLITE_NULL is 0x10.
**
** WARNING: This opcode does not reliably distinguish between NULL and REAL
** when P1>=0.  If the database contains a NaN value, this opcode will think
** that the datatype is REAL when it should be NULL.  When P1<0 and the value
** is already stored in register P3, then this opcode does reliably
** distinguish between NULL and REAL.  The problem only arises then P1>=0.
**
** Take the jump to address P2 if and only if the datatype of the
** value determined by P1 and P3 corresponds to one of the bits in the
** P5 bitmask.
**
*/
case OP_IsType: {        /* jump */
  VdbeCursor *pC;

**
** If P1 is not an open cursor, then this opcode is a no-op.
*/
case OP_IfNullRow: {         /* jump */
  VdbeCursor *pC;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  if( pC && pC->nullRow ){
    sqlite3VdbeMemSetNull(aMem + pOp->p3);
    goto jump_to_p2;
  }
  break;
}

#ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC

      testcase( pIn1->u.i==-140737488355329LL );
      if( pIn1->u.i<=140737488355327LL && pIn1->u.i>=-140737488355328LL ){
        pIn1->flags |= MEM_IntReal;
        pIn1->flags &= ~MEM_Int;
      }else{
        pIn1->u.r = (double)pIn1->u.i;
        pIn1->flags |= MEM_Real;
        pIn1->flags &= ~(MEM_Int|MEM_Str);
      }
    }
    REGISTER_TRACE((int)(pIn1-aMem), pIn1);
    zAffinity++;
    if( zAffinity[0]==0 ) break;
    pIn1++;
  }

        printf("... fall through after %d steps\n", pOp->p1);
      }
#endif
      VdbeBranchTaken(0,3);
      break;
    }
    nStep--;
    pC->cacheStatus = CACHE_STALE;
    rc = sqlite3BtreeNext(pC->uc.pCursor, 0);
    if( rc ){
      if( rc==SQLITE_DONE ){
        rc = SQLITE_OK;
        goto seekscan_search_fail;
      }else{
        goto abort_due_to_error;

  if( rc ){
    sqlite3VdbeError(p, "%s", sqlite3_value_text(pMem));
    goto abort_due_to_error;
  }
  sqlite3VdbeChangeEncoding(pMem, encoding);
  UPDATE_MAX_BLOBSIZE(pMem);
  REGISTER_TRACE((int)(pMem-aMem), pMem);
  break;
}

#ifndef SQLITE_OMIT_WAL
/* Opcode: Checkpoint P1 P2 P3 * *
**
** Checkpoint database P1. This is a no-op if P1 is not currently in

*****************************************************************************/
    }

#if defined(VDBE_PROFILE)
    *pnCycle += sqlite3NProfileCnt ? sqlite3NProfileCnt : sqlite3Hwtime();
    pnCycle = 0;
#elif defined(SQLITE_ENABLE_STMT_SCANSTATUS)
    if( pnCycle ){
      *pnCycle += sqlite3Hwtime();
      pnCycle = 0;
    }
#endif

    /* The following code adds nothing to the actual functionality
    ** of the program.  It is only here for testing and debugging.
    ** On the other hand, it does burn CPU cycles every time through
    ** the evaluator loop.  So we can leave it out when NDEBUG is defined.
    */

blob_open_out:
  if( rc==SQLITE_OK && db->mallocFailed==0 ){
    *ppBlob = (sqlite3_blob *)pBlob;
  }else{
    if( pBlob && pBlob->pStmt ) sqlite3VdbeFinalize((Vdbe *)pBlob->pStmt);
    sqlite3DbFree(db, pBlob);
  }
  sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : (char*)0), zErr);
  sqlite3DbFree(db, zErr);
  sqlite3ParseObjectReset(&sParse);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

    */
    rc = SQLITE_ABORT;
  }else{
    char *zErr;
    ((Vdbe*)p->pStmt)->rc = SQLITE_OK;
    rc = blobSeekToRow(p, iRow, &zErr);
    if( rc!=SQLITE_OK ){
      sqlite3ErrorWithMsg(db, rc, (zErr ? "%s" : (char*)0), zErr);
      sqlite3DbFree(db, zErr);
    }
    assert( rc!=SQLITE_SCHEMA );
  }

  rc = sqlite3ApiExit(db, rc);
  assert( rc==SQLITE_OK || p->pStmt==0 );

      pTab = 0;
#ifndef SQLITE_OMIT_TRIGGER
      if( pParse->pTriggerTab!=0 ){
        int op = pParse->eTriggerOp;
        assert( op==TK_DELETE || op==TK_UPDATE || op==TK_INSERT );
        if( pParse->bReturning ){
          if( (pNC->ncFlags & NC_UBaseReg)!=0
           && ALWAYS(zTab==0
                     || sqlite3StrICmp(zTab,pParse->pTriggerTab->zName)==0)
          ){
            pExpr->iTable = op!=TK_DELETE;
            pTab = pParse->pTriggerTab;
          }
        }else if( op!=TK_DELETE && zTab && sqlite3StrICmp("new",zTab) == 0 ){
          pExpr->iTable = 1;
          pTab = pParse->pTriggerTab;

          notValidImpl(pParse, pNC, "subqueries", pExpr, pExpr);
        }else{
          sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
        }
        assert( pNC->nRef>=nRef );
        if( nRef!=pNC->nRef ){
          ExprSetProperty(pExpr, EP_VarSelect);

        }
        pNC->ncFlags |= NC_Subquery;
      }
      break;
    }
    case TK_VARIABLE: {
      testcase( pNC->ncFlags & NC_IsCheck );
      testcase( pNC->ncFlags & NC_PartIdx );
      testcase( pNC->ncFlags & NC_IdxExpr );

    }
    if( p->flags & EP_Collate ){
      if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
        p = p->pLeft;
      }else{
        Expr *pNext  = p->pRight;
        /* The Expr.x union is never used at the same time as Expr.pRight */

        assert( !ExprUseXList(p) || p->x.pList==0 || p->pRight==0 );
        if( ExprUseXList(p) && p->x.pList!=0 && !db->mallocFailed ){
          int i;
          for(i=0; i<p->x.pList->nExpr; i++){
            if( ExprHasProperty(p->x.pList->a[i].pExpr, EP_Collate) ){
              pNext = p->x.pList->a[i].pExpr;
              break;
            }
          }
        }
        p = pNext;

  return pRet;
}

/*
** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
**
** If one side or the other of the AND is known to be false, and neither side
** is part of an ON clause, then instead of returning an AND expression,
** just return a constant expression with a value of false.
*/
SQLITE_PRIVATE Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
  sqlite3 *db = pParse->db;
  if( pLeft==0  ){
    return pRight;
  }else if( pRight==0 ){
    return pLeft;
  }else{
    u32 f = pLeft->flags | pRight->flags;
    if( (f&(EP_OuterON|EP_InnerON|EP_IsFalse))==EP_IsFalse
     && !IN_RENAME_OBJECT
    ){
      sqlite3ExprDeferredDelete(pParse, pLeft);
      sqlite3ExprDeferredDelete(pParse, pRight);
      return sqlite3Expr(db, TK_INTEGER, "0");
    }else{
      return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
    }
  }
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/

** table other than iCur.
*/
SQLITE_PRIVATE int sqlite3ExprIsTableConstant(Expr *p, int iCur){
  return exprIsConst(p, 3, iCur);
}

/*
** Check pExpr to see if it is an constraint on the single data source
** pSrc = &pSrcList->a[iSrc].  In other words, check to see if pExpr
** constrains pSrc but does not depend on any other tables or data
** sources anywhere else in the query.  Return true (non-zero) if pExpr
** is a constraint on pSrc only.
**
** This is an optimization.  False negatives will perhaps cause slower
** queries, but false positives will yield incorrect answers.  So when in
** doubt, return 0.
**
** To be an single-source constraint, the following must be true:
**
**   (1)  pExpr cannot refer to any table other than pSrc->iCursor.
**
**   (2)  pExpr cannot use subqueries or non-deterministic functions.
**
**   (3)  pSrc cannot be part of the left operand for a RIGHT JOIN.
**        (Is there some way to relax this constraint?)
**
**   (4)  If pSrc is the right operand of a LEFT JOIN, then...
**         (4a)  pExpr must come from an ON clause..
**         (4b)  and specifically the ON clause associated with the LEFT JOIN.
**
**   (5)  If pSrc is not the right operand of a LEFT JOIN or the left
**        operand of a RIGHT JOIN, then pExpr must be from the WHERE
**        clause, not an ON clause.
**
**   (6) Either:
**
**       (6a) pExpr does not originate in an ON or USING clause, or
**
**       (6b) The ON or USING clause from which pExpr is derived is
**            not to the left of a RIGHT JOIN (or FULL JOIN).
**
**       Without this restriction, accepting pExpr as a single-table
**       constraint might move the the ON/USING filter expression
**       from the left side of a RIGHT JOIN over to the right side,
**       which leads to incorrect answers.  See also restriction (9)
**       on push-down.
*/
SQLITE_PRIVATE int sqlite3ExprIsSingleTableConstraint(
  Expr *pExpr,                 /* The constraint */
  const SrcList *pSrcList,     /* Complete FROM clause */
  int iSrc                     /* Which element of pSrcList to use */
){
  const SrcItem *pSrc = &pSrcList->a[iSrc];
  if( pSrc->fg.jointype & JT_LTORJ ){
    return 0;  /* rule (3) */
  }
  if( pSrc->fg.jointype & JT_LEFT ){
    if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0;   /* rule (4a) */
    if( pExpr->w.iJoin!=pSrc->iCursor ) return 0;         /* rule (4b) */
  }else{
    if( ExprHasProperty(pExpr, EP_OuterON) ) return 0;    /* rule (5) */
  }
  if( ExprHasProperty(pExpr, EP_OuterON|EP_InnerON)  /* (6a) */
   && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0     /* Fast pre-test of (6b) */
  ){
    int jj;
    for(jj=0; jj<iSrc; jj++){
      if( pExpr->w.iJoin==pSrcList->a[jj].iCursor ){
        if( (pSrcList->a[jj].fg.jointype & JT_LTORJ)!=0 ){
          return 0;  /* restriction (6) */
        }
        break;
      }
    }
  }
  return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor); /* rules (1), (2) */
}


/*
** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().

  return 0;
}

/*
** pX is the RHS of an IN operator.  If pX is a SELECT statement
** that can be simplified to a direct table access, then return
** a pointer to the SELECT statement.  If pX is not a SELECT statement,
** or if the SELECT statement needs to be materialized into a transient
** table, then return NULL.
*/
#ifndef SQLITE_OMIT_SUBQUERY
static Select *isCandidateForInOpt(const Expr *pX){
  Select *p;
  SrcList *pSrc;
  ExprList *pEList;

          colUsed = 0;   /* Columns of index used so far */
          for(i=0; i<nExpr; i++){
            Expr *pLhs = sqlite3VectorFieldSubexpr(pX->pLeft, i);
            Expr *pRhs = pEList->a[i].pExpr;
            CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
            int j;


            for(j=0; j<nExpr; j++){
              if( pIdx->aiColumn[j]!=pRhs->iColumn ) continue;
              assert( pIdx->azColl[j] );
              if( pReq!=0 && sqlite3StrICmp(pReq->zName, pIdx->azColl[j])!=0 ){
                continue;
              }
              break;

  Parse *pParse,     /* Parsing context */
  Table *pTab,       /* Table containing the generated column */
  Column *pCol,      /* The generated column */
  int regOut         /* Put the result in this register */
){
  int iAddr;
  Vdbe *v = pParse->pVdbe;
  int nErr = pParse->nErr;
  assert( v!=0 );
  assert( pParse->iSelfTab!=0 );
  if( pParse->iSelfTab>0 ){
    iAddr = sqlite3VdbeAddOp3(v, OP_IfNullRow, pParse->iSelfTab-1, 0, regOut);
  }else{
    iAddr = 0;
  }
  sqlite3ExprCodeCopy(pParse, sqlite3ColumnExpr(pTab,pCol), regOut);
  if( pCol->affinity>=SQLITE_AFF_TEXT ){
    sqlite3VdbeAddOp4(v, OP_Affinity, regOut, 1, 0, &pCol->affinity, 1);
  }
  if( iAddr ) sqlite3VdbeJumpHere(v, iAddr);
  if( pParse->nErr>nErr ) pParse->db->errByteOffset = -1;
}
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */

/*
** Generate code to extract the value of the iCol-th column of a table.
*/
SQLITE_PRIVATE void sqlite3ExprCodeGetColumnOfTable(
  Vdbe *v,        /* Parsing context */
  Table *pTab,    /* The table containing the value */
  int iTabCur,    /* The table cursor.  Or the PK cursor for WITHOUT ROWID */
  int iCol,       /* Index of the column to extract */
  int regOut      /* Extract the value into this register */
){
  Column *pCol;
  assert( v!=0 );
  assert( pTab!=0 );
  assert( iCol!=XN_EXPR );
  if( iCol<0 || iCol==pTab->iPKey ){
    sqlite3VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
    VdbeComment((v, "%s.rowid", pTab->zName));
  }else{
    int op;
    int x;
    if( IsVirtual(pTab) ){

    op = pExpr->op;
  }
  switch( op ){
    case TK_AGG_COLUMN: {
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol;
      assert( pAggInfo!=0 );
      assert( pExpr->iAgg>=0 );
      if( pExpr->iAgg>=pAggInfo->nColumn ){
        /* Happens when the left table of a RIGHT JOIN is null and
        ** is using an expression index */
        sqlite3VdbeAddOp2(v, OP_Null, 0, target);
#ifdef SQLITE_VDBE_COVERAGE
        /* Verify that the OP_Null above is exercised by tests
        ** tag-20230325-2 */
        sqlite3VdbeAddOp2(v, OP_NotNull, target, 1);
        VdbeCoverageNeverTaken(v);
#endif
        break;
      }
      pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        return AggInfoColumnReg(pAggInfo, pExpr->iAgg);
      }else if( pAggInfo->useSortingIdx ){
        Table *pTab = pCol->pTab;
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                              pCol->iSorterColumn, target);

    }
    case TK_REGISTER: {
      return pExpr->iTable;
    }
#ifndef SQLITE_OMIT_CAST
    case TK_CAST: {
      /* Expressions of the form:   CAST(pLeft AS token) */
      sqlite3ExprCode(pParse, pExpr->pLeft, target);
      assert( inReg==target );



      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      sqlite3VdbeAddOp2(v, OP_Cast, target,
                        sqlite3AffinityType(pExpr->u.zToken, 0));
      return inReg;
    }
#endif /* SQLITE_OMIT_CAST */
    case TK_IS:

      if( !ExprHasProperty(pExpr, EP_Collate) ){
        /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
        ** "SOFT-COLLATE" that is added to constraints that are pushed down
        ** from outer queries into sub-queries by the push-down optimization.
        ** Clear subtypes as subtypes may not cross a subquery boundary.
        */
        assert( pExpr->pLeft );
        sqlite3ExprCode(pParse, pExpr->pLeft, target);




        sqlite3VdbeAddOp1(v, OP_ClrSubtype, target);
        return target;
      }else{
        pExpr = pExpr->pLeft;
        goto expr_code_doover; /* 2018-04-28: Prevent deep recursion. */
      }
    }
    case TK_SPAN:
    case TK_UPLUS: {

      ** NULL.  So we have to ensure that the result register is not a value
      ** that is suppose to be a constant.  Two defenses are needed:
      **   (1)  Temporarily disable factoring of constant expressions
      **   (2)  Make sure the computed value really is stored in register
      **        "target" and not someplace else.
      */
      pParse->okConstFactor = 0;   /* note (1) above */
      sqlite3ExprCode(pParse, pExpr->pLeft, target);
      assert( target==inReg );
      pParse->okConstFactor = okConstFactor;




      sqlite3VdbeJumpHere(v, addrINR);
      break;
    }

    /*
    ** Form A:
    **   CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END

  assert( pExpr==0 || !ExprHasVVAProperty(pExpr,EP_Immutable) );
  assert( target>0 && target<=pParse->nMem );
  assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
  if( pParse->pVdbe==0 ) return;
  inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
  if( inReg!=target ){
    u8 op;
    if( ALWAYS(pExpr)
     && (ExprHasProperty(pExpr,EP_Subquery) || pExpr->op==TK_REGISTER)
    ){
      op = OP_Copy;
    }else{
      op = OP_SCopy;
    }
    sqlite3VdbeAddOp2(pParse->pVdbe, op, inReg, target);
  }
}

  if( ALWAYS(!ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced))
   && pExpr->pAggInfo!=0
  ){
    AggInfo *pAggInfo = pExpr->pAggInfo;
    int iAgg = pExpr->iAgg;
    Parse *pParse = pWalker->pParse;
    sqlite3 *db = pParse->db;
    assert( iAgg>=0 );
    if( pExpr->op!=TK_AGG_FUNCTION ){
      if( iAgg<pAggInfo->nColumn
       && pAggInfo->aCol[iAgg].pCExpr==pExpr
      ){
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        if( pExpr ){
          pAggInfo->aCol[iAgg].pCExpr = pExpr;
          sqlite3ExprDeferredDelete(pParse, pExpr);
        }
      }
    }else{
      assert( pExpr->op==TK_AGG_FUNCTION );
      if( ALWAYS(iAgg<pAggInfo->nFunc)
       && pAggInfo->aFunc[iAgg].pFExpr==pExpr
      ){
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        if( pExpr ){
          pAggInfo->aFunc[iAgg].pFExpr = pExpr;
          sqlite3ExprDeferredDelete(pParse, pExpr);
        }
      }
    }

      for(pIEpr=pParse->pIdxEpr; pIEpr; pIEpr=pIEpr->pIENext){
        int iDataCur = pIEpr->iDataCur;
        if( iDataCur<0 ) continue;
        if( sqlite3ExprCompare(0, pExpr, pIEpr->pExpr, iDataCur)==0 ) break;
      }
      if( pIEpr==0 ) break;
      if( NEVER(!ExprUseYTab(pExpr)) ) break;
      for(i=0; i<pSrcList->nSrc; i++){
         if( pSrcList->a[0].iCursor==pIEpr->iDataCur ) break;
      }
      if( i>=pSrcList->nSrc ) break;
      if( NEVER(pExpr->pAggInfo!=0) ) break; /* Resolved by outer context */
      if( pParse->nErr ){ return WRC_Abort; }

      /* If we reach this point, it means that expression pExpr can be
      ** translated into a reference to an index column as described by
      ** pIEpr.
      */
      memset(&tmp, 0, sizeof(tmp));
      tmp.op = TK_AGG_COLUMN;
      tmp.iTable = pIEpr->iIdxCur;
      tmp.iColumn = pIEpr->iIdxCol;
      findOrCreateAggInfoColumn(pParse, pAggInfo, &tmp);
      if( pParse->nErr ){ return WRC_Abort; }
      assert( pAggInfo->aCol!=0 );
      assert( tmp.iAgg<pAggInfo->nColumn );
      pAggInfo->aCol[tmp.iAgg].pCExpr = pExpr;
      pExpr->pAggInfo = pAggInfo;
      pExpr->iAgg = tmp.iAgg;
      return WRC_Prune;
    }
    case TK_IF_NULL_ROW:
    case TK_AGG_COLUMN:

          assert( !ExprHasProperty(pExpr, EP_TokenOnly|EP_Reduced) );
          if( pExpr->iTable==pItem->iCursor ){
            findOrCreateAggInfoColumn(pParse, pAggInfo, pExpr);
            break;
          } /* endif pExpr->iTable==pItem->iCursor */
        } /* end loop over pSrcList */
      }
      return WRC_Continue;
    }
    case TK_AGG_FUNCTION: {
      if( (pNC->ncFlags & NC_InAggFunc)==0
       && pWalker->walkerDepth==pExpr->op2
      ){
        /* Check to see if pExpr is a duplicate of another aggregate
        ** function that is already in the pAggInfo structure

** invokes the sub/co-routine.
*/
SQLITE_PRIVATE void sqlite3ClearTempRegCache(Parse *pParse){
  pParse->nTempReg = 0;
  pParse->nRangeReg = 0;
}

/*
** Make sure sufficient registers have been allocated so that
** iReg is a valid register number.
*/
SQLITE_PRIVATE void sqlite3TouchRegister(Parse *pParse, int iReg){
  if( pParse->nMem<iReg ) pParse->nMem = iReg;
}

#if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
/*
** Return the latest reusable register in the set of all registers.
** The value returned is no less than iMin.  If any register iMin or
** greater is in permanent use, then return one more than that last
** permanent register.
*/
SQLITE_PRIVATE int sqlite3FirstAvailableRegister(Parse *pParse, int iMin){
  const ExprList *pList = pParse->pConstExpr;
  if( pList ){
    int i;
    for(i=0; i<pList->nExpr; i++){
      if( pList->a[i].u.iConstExprReg>=iMin ){
        iMin = pList->a[i].u.iConstExprReg + 1;
      }
    }
  }
  pParse->nTempReg = 0;
  pParse->nRangeReg = 0;
  return iMin;
}
#endif /* SQLITE_ENABLE_STAT4 || SQLITE_DEBUG */

/*
** Validate that no temporary register falls within the range of
** iFirst..iLast, inclusive.  This routine is only call from within assert()
** statements.
*/
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE int sqlite3NoTempsInRange(Parse *pParse, int iFirst, int iLast){
  int i;
  if( pParse->nRangeReg>0
   && pParse->iRangeReg+pParse->nRangeReg > iFirst
   && pParse->iRangeReg <= iLast
  ){
     return 0;
  }
  for(i=0; i<pParse->nTempReg; i++){
    if( pParse->aTempReg[i]>=iFirst && pParse->aTempReg[i]<=iLast ){
      return 0;
    }
  }
  if( pParse->pConstExpr ){
    ExprList *pList = pParse->pConstExpr;
    for(i=0; i<pList->nExpr; i++){
      int iReg = pList->a[i].u.iConstExprReg;
      if( iReg==0 ) continue;
      if( iReg>=iFirst && iReg<=iLast ) return 0;
    }
  }
  return 1;
}
#endif /* SQLITE_DEBUG */

/************** End of expr.c ************************************************/
/************** Begin file alter.c *******************************************/

  }else{
    rc = SQLITE_NOMEM;
  }

  sqlite3_free(zQuot);
  return rc;
}

/*
** Set all pEList->a[].fg.eEName fields in the expression-list to val.
*/
static void renameSetENames(ExprList *pEList, int val){
  if( pEList ){
    int i;
    for(i=0; i<pEList->nExpr; i++){
      assert( val==ENAME_NAME || pEList->a[i].fg.eEName==ENAME_NAME );
      pEList->a[i].fg.eEName = val;
    }
  }
}

/*
** Resolve all symbols in the trigger at pParse->pNewTrigger, assuming
** it was read from the schema of database zDb. Return SQLITE_OK if
** successful. Otherwise, return an SQLite error code and leave an error
** message in the Parse object.
*/

            pParse, pStep->pExprList, pSrc, 0, 0, 0, 0, 0, 0
        );
        if( pSel==0 ){
          pStep->pExprList = 0;
          pSrc = 0;
          rc = SQLITE_NOMEM;
        }else{
          /* pStep->pExprList contains an expression-list used for an UPDATE
          ** statement. So the a[].zEName values are the RHS of the
          ** "<col> = <expr>" clauses of the UPDATE statement. So, before
          ** running SelectPrep(), change all the eEName values in
          ** pStep->pExprList to ENAME_SPAN (from their current value of
          ** ENAME_NAME). This is to prevent any ids in ON() clauses that are
          ** part of pSrc from being incorrectly resolved against the
          ** a[].zEName values as if they were column aliases.  */
          renameSetENames(pStep->pExprList, ENAME_SPAN);
          sqlite3SelectPrep(pParse, pSel, 0);
          renameSetENames(pStep->pExprList, ENAME_NAME);
          rc = pParse->nErr ? SQLITE_ERROR : SQLITE_OK;
          assert( pStep->pExprList==0 || pStep->pExprList==pSel->pEList );
          assert( pSrc==pSel->pSrc );
          if( pStep->pExprList ) pSel->pEList = 0;
          pSel->pSrc = 0;
          sqlite3SelectDelete(db, pSel);
        }

  int regRowid = iMem++;       /* Rowid argument passed to stat_push() */
  int regTemp = iMem++;        /* Temporary use register */
  int regTemp2 = iMem++;       /* Second temporary use register */
  int regTabname = iMem++;     /* Register containing table name */
  int regIdxname = iMem++;     /* Register containing index name */
  int regStat1 = iMem++;       /* Value for the stat column of sqlite_stat1 */
  int regPrev = iMem;          /* MUST BE LAST (see below) */
#ifdef SQLITE_ENABLE_STAT4
  int doOnce = 1;              /* Flag for a one-time computation */
#endif
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
  Table *pStat1 = 0;
#endif

  sqlite3TouchRegister(pParse, iMem);
  assert( sqlite3NoTempsInRange(pParse, regNewRowid, iMem) );
  v = sqlite3GetVdbe(pParse);
  if( v==0 || NEVER(pTab==0) ){
    return;
  }
  if( !IsOrdinaryTable(pTab) ){
    /* Do not gather statistics on views or virtual tables */
    return;

    **  end_of_scan:
    */

    /* Make sure there are enough memory cells allocated to accommodate
    ** the regPrev array and a trailing rowid (the rowid slot is required
    ** when building a record to insert into the sample column of
    ** the sqlite_stat4 table.  */
    sqlite3TouchRegister(pParse, regPrev+nColTest);

    /* Open a read-only cursor on the index being analyzed. */
    assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) );
    sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb);
    sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
    VdbeComment((v, "%s", pIdx->zName));

      int regSample = regStat1+3;
      int regCol = regStat1+4;
      int regSampleRowid = regCol + nCol;
      int addrNext;
      int addrIsNull;
      u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound;

      if( doOnce ){
        int mxCol = nCol;
        Index *pX;

        /* Compute the maximum number of columns in any index */
        for(pX=pTab->pIndex; pX; pX=pX->pNext){
          int nColX;                     /* Number of columns in pX */
          if( !HasRowid(pTab) && IsPrimaryKeyIndex(pX) ){
            nColX = pX->nKeyCol;
          }else{
            nColX = pX->nColumn;
          }
          if( nColX>mxCol ) mxCol = nColX;
        }

        /* Allocate space to compute results for the largest index */
        sqlite3TouchRegister(pParse, regCol+mxCol);
        doOnce = 0;
#ifdef SQLITE_DEBUG
        /* Verify that the call to sqlite3ClearTempRegCache() below
        ** really is needed.
        ** https://sqlite.org/forum/forumpost/83cb4a95a0 (2023-03-25)
        */
        testcase( !sqlite3NoTempsInRange(pParse, regEq, regCol+mxCol) );
#endif
        sqlite3ClearTempRegCache(pParse);  /* tag-20230325-1 */
        assert( sqlite3NoTempsInRange(pParse, regEq, regCol+mxCol) );
      }
      assert( sqlite3NoTempsInRange(pParse, regEq, regCol+nCol) );

      addrNext = sqlite3VdbeCurrentAddr(v);
      callStatGet(pParse, regStat, STAT_GET_ROWID, regSampleRowid);
      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid);
      VdbeCoverage(v);
      callStatGet(pParse, regStat, STAT_GET_NEQ, regEq);
      callStatGet(pParse, regStat, STAT_GET_NLT, regLt);

  openStatTable(pParse, iDb, iStatCur, 0, 0);
  iMem = pParse->nMem+1;
  iTab = pParse->nTab;
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
    Table *pTab = (Table*)sqliteHashData(k);
    analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab);
#ifdef SQLITE_ENABLE_STAT4
    iMem = sqlite3FirstAvailableRegister(pParse, iMem);
#else
    assert( iMem==sqlite3FirstAvailableRegister(pParse,iMem) );
#endif
  }
  loadAnalysis(pParse, iDb);
}

/*
** Generate code that will do an analysis of a single table in
** a database.  If pOnlyIdx is not NULL then it is a single index

    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    nSample = sqlite3_column_int(pStmt, 1);
    pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
    assert( pIdx==0 || pIdx->nSample==0 );
    if( pIdx==0 ) continue;
    if( pIdx->aSample!=0 ){
      /* The same index appears in sqlite_stat4 under multiple names */
      continue;
    }
    assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 );
    if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){
      nIdxCol = pIdx->nKeyCol;
    }else{
      nIdxCol = pIdx->nColumn;
    }
    pIdx->nSampleCol = nIdxCol;
    pIdx->mxSample = nSample;
    nByte = sizeof(IndexSample) * nSample;
    nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample;
    nByte += nIdxCol * sizeof(tRowcnt);     /* Space for Index.aAvgEq[] */

    pIdx->aSample = sqlite3DbMallocZero(db, nByte);
    if( pIdx->aSample==0 ){
      sqlite3_finalize(pStmt);

    Index *pIdx;                  /* Pointer to the index object */
    int nCol = 1;                 /* Number of columns in index */

    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
    if( pIdx==0 ) continue;
    if( pIdx->nSample>=pIdx->mxSample ){
      /* Too many slots used because the same index appears in
      ** sqlite_stat4 using multiple names */
      continue;
    }
    /* This next condition is true if data has already been loaded from
    ** the sqlite_stat4 table. */
    nCol = pIdx->nSampleCol;
    if( pIdx!=pPrevIdx ){
      initAvgEq(pPrevIdx);
      pPrevIdx = pIdx;
    }

** the Index.aSample[] arrays of all indices.
*/
static int loadStat4(sqlite3 *db, const char *zDb){
  int rc = SQLITE_OK;             /* Result codes from subroutines */
  const Table *pStat4;

  assert( db->lookaside.bDisable );
  if( OptimizationEnabled(db, SQLITE_Stat4)
   && (pStat4 = sqlite3FindTable(db, "sqlite_stat4", zDb))!=0
   && IsOrdinaryTable(pStat4)
  ){
    rc = loadStatTbl(db,
      "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx COLLATE nocase",
      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
      zDb
    );
  }
  return rc;
}
#endif /* SQLITE_ENABLE_STAT4 */

    }
    sqlite3FreeIndex(db, pIndex);
  }

  if( IsOrdinaryTable(pTable) ){
    sqlite3FkDelete(db, pTable);
  }
#ifndef SQLITE_OMIT_VIRTUALTABLE
  else if( IsVirtual(pTable) ){
    sqlite3VtabClear(db, pTable);
  }
#endif
  else{
    assert( IsView(pTable) );
    sqlite3SelectDelete(db, pTable->u.view.pSelect);

SQLITE_PRIVATE void sqlite3AddReturning(Parse *pParse, ExprList *pList){
  Returning *pRet;
  Hash *pHash;
  sqlite3 *db = pParse->db;
  if( pParse->pNewTrigger ){
    sqlite3ErrorMsg(pParse, "cannot use RETURNING in a trigger");
  }else{
    assert( pParse->bReturning==0 || pParse->ifNotExists );
  }
  pParse->bReturning = 1;
  pRet = sqlite3DbMallocZero(db, sizeof(*pRet));
  if( pRet==0 ){
    sqlite3ExprListDelete(db, pList);
    return;
  }

  pRet->retTrig.pSchema = db->aDb[1].pSchema;
  pRet->retTrig.pTabSchema = db->aDb[1].pSchema;
  pRet->retTrig.step_list = &pRet->retTStep;
  pRet->retTStep.op = TK_RETURNING;
  pRet->retTStep.pTrig = &pRet->retTrig;
  pRet->retTStep.pExprList = pList;
  pHash = &(db->aDb[1].pSchema->trigHash);
  assert( sqlite3HashFind(pHash, RETURNING_TRIGGER_NAME)==0
          || pParse->nErr  || pParse->ifNotExists );
  if( sqlite3HashInsert(pHash, RETURNING_TRIGGER_NAME, &pRet->retTrig)
          ==&pRet->retTrig ){
    sqlite3OomFault(db);
  }
}

/*

SQLITE_PRIVATE void sqlite3SetTextEncoding(sqlite3 *db, u8 enc){
  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
  db->enc = enc;
  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
  ** strings is BINARY.
  */
  db->pDfltColl = sqlite3FindCollSeq(db, enc, sqlite3StrBINARY, 0);
  sqlite3ExpirePreparedStatements(db, 1);
}

/*
** This function is responsible for invoking the collation factory callback
** or substituting a collation sequence of a different encoding when the
** requested collation sequence is not available in the desired encoding.
**

/*
** Check to make sure the given table is writable.
**
** If pTab is not writable  ->  generate an error message and return 1.
** If pTab is writable but other errors have occurred -> return 1.
** If pTab is writable and no prior errors -> return 0;
*/
SQLITE_PRIVATE int sqlite3IsReadOnly(Parse *pParse, Table *pTab, Trigger *pTrigger){
  if( tabIsReadOnly(pParse, pTab) ){
    sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
    return 1;
  }
#ifndef SQLITE_OMIT_VIEW
  if( IsView(pTab)
   && (pTrigger==0 || (pTrigger->bReturning && pTrigger->pNext==0))
  ){
    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
    return 1;
  }
#endif
  return 0;
}

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

  if( sqlite3IsReadOnly(pParse, pTab, pTrigger) ){
    goto delete_from_cleanup;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb<db->nDb );
  rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0,
                            db->aDb[iDb].zDbSName);
  assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );

        sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
      }
    }
  }else
#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
  {
    u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
    if( sNC.ncFlags & NC_Subquery ) bComplex = 1;
    wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
    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);

}


#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
/*
** The "unknown" function is automatically substituted in place of
** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN
** when the SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION compile-time option is used.
** When the "sqlite3" command-line shell is built using this functionality,
** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries
** involving application-defined functions to be examined in a generic
** sqlite3 shell.
*/
static void unknownFunc(
  sqlite3_context *context,

    sqlite3DbFree(db, aiCol);

    zFrom = pFKey->pFrom->zName;
    nFrom = sqlite3Strlen30(zFrom);

    if( action==OE_Restrict ){
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      SrcList *pSrc;

      Expr *pRaise;






      pRaise = sqlite3Expr(db, TK_RAISE, "FOREIGN KEY constraint failed");
      if( pRaise ){
        pRaise->affExpr = OE_Abort;
      }
      pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
      if( pSrc ){
        assert( pSrc->nSrc==1 );
        pSrc->a[0].zName = sqlite3DbStrDup(db, zFrom);
        pSrc->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
      }
      pSelect = sqlite3SelectNew(pParse,
          sqlite3ExprListAppend(pParse, 0, pRaise),
          pSrc,
          pWhere,
          0, 0, 0, 0, 0
      );
      pWhere = 0;
    }

    /* Disable lookaside memory allocation */

** An extra 'D' is appended to the end of the string to cover the
** rowid that appears as the last column in every index.
**
** Memory for the buffer containing the column index affinity string
** is managed along with the rest of the Index structure. It will be
** released when sqlite3DeleteIndex() is called.
*/
static SQLITE_NOINLINE const char *computeIndexAffStr(sqlite3 *db, Index *pIdx){

  /* The first time a column affinity string for a particular index is
  ** required, it is allocated and populated here. It is then stored as
  ** a member of the Index structure for subsequent use.
  **
  ** The column affinity string will eventually be deleted by
  ** sqliteDeleteIndex() when the Index structure itself is cleaned
  ** up.
  */
  int n;
  Table *pTab = pIdx->pTable;
  pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
  if( !pIdx->zColAff ){
    sqlite3OomFault(db);
    return 0;
  }
  for(n=0; n<pIdx->nColumn; n++){
    i16 x = pIdx->aiColumn[n];
    char aff;
    if( x>=0 ){
      aff = pTab->aCol[x].affinity;
    }else if( x==XN_ROWID ){
      aff = SQLITE_AFF_INTEGER;
    }else{
      assert( x==XN_EXPR );
      assert( pIdx->bHasExpr );
      assert( pIdx->aColExpr!=0 );
      aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
    }
    if( aff<SQLITE_AFF_BLOB ) aff = SQLITE_AFF_BLOB;
    if( aff>SQLITE_AFF_NUMERIC) aff = SQLITE_AFF_NUMERIC;
    pIdx->zColAff[n] = aff;
  }
  pIdx->zColAff[n] = 0;
  return pIdx->zColAff;
}
SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
  if( !pIdx->zColAff ) return computeIndexAffStr(db, pIdx);
  return pIdx->zColAff;
}


/*
** Compute an affinity string for a table.   Space is obtained
** from sqlite3DbMalloc().  The caller is responsible for freeing
** the space when done.
*/
SQLITE_PRIVATE char *sqlite3TableAffinityStr(sqlite3 *db, const Table *pTab){

  */
  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto insert_cleanup;
  }

  /* Cannot insert into a read-only table.
  */
  if( sqlite3IsReadOnly(pParse, pTab, pTrigger) ){
    goto insert_cleanup;
  }

  /* Allocate a VDBE
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto insert_cleanup;

      addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
      sqlite3VdbeJumpHere(v, addr1);
      sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
    }

    /* Copy the new data already generated. */
    assert( pTab->nNVCol>0 || pParse->nErr>0 );
    sqlite3VdbeAddOp3(v, OP_Copy, regRowid+1, regCols+1, pTab->nNVCol-1);

#ifndef SQLITE_OMIT_GENERATED_COLUMNS
    /* Compute the new value for generated columns after all other
    ** columns have already been computed.  This must be done after
    ** computing the ROWID in case one of the generated columns
    ** refers to the ROWID. */

  }

  zEntry = zProc ? zProc : "sqlite3_extension_init";

  /* tag-20210611-1.  Some dlopen() implementations will segfault if given
  ** an oversize filename.  Most filesystems have a pathname limit of 4K,
  ** so limit the extension filename length to about twice that.
  ** https://sqlite.org/forum/forumpost/08a0d6d9bf
  **
  ** Later (2023-03-25): Save an extra 6 bytes for the filename suffix.
  ** See https://sqlite.org/forum/forumpost/24083b579d.
  */
  if( nMsg>SQLITE_MAX_PATHLEN ) goto extension_not_found;

  handle = sqlite3OsDlOpen(pVfs, zFile);
#if SQLITE_OS_UNIX || SQLITE_OS_WIN
  for(ii=0; ii<ArraySize(azEndings) && handle==0; ii++){
    char *zAltFile = sqlite3_mprintf("%s.%s", zFile, azEndings[ii]);
    if( zAltFile==0 ) return SQLITE_NOMEM_BKPT;
    if( nMsg+strlen(azEndings[ii])+1<=SQLITE_MAX_PATHLEN ){
      handle = sqlite3OsDlOpen(pVfs, zAltFile);
    }
    sqlite3_free(zAltFile);
  }
#endif
  if( handle==0 ) goto extension_not_found;
  xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);

  /* If no entry point was specified and the default legacy

        k = sqliteHashNext(k);
      }
      if( pTab==0 || !IsOrdinaryTable(pTab) || pTab->u.tab.pFKey==0 ) continue;
      iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      zDb = db->aDb[iDb].zDbSName;
      sqlite3CodeVerifySchema(pParse, iDb);
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
      sqlite3TouchRegister(pParse, pTab->nCol+regRow);
      sqlite3OpenTable(pParse, 0, iDb, pTab, OP_OpenRead);
      sqlite3VdbeLoadString(v, regResult, pTab->zName);
      assert( IsOrdinaryTable(pTab) );
      for(i=1, pFK=pTab->u.tab.pFKey; pFK; i++, pFK=pFK->pNextFrom){
        pParent = sqlite3FindTable(db, pFK->zTo, zDb);
        if( pParent==0 ) continue;
        pIdx = 0;

        }
        addrOk = sqlite3VdbeMakeLabel(pParse);

        /* Generate code to read the child key values into registers
        ** regRow..regRow+n. If any of the child key values are NULL, this
        ** row cannot cause an FK violation. Jump directly to addrOk in
        ** this case. */
        sqlite3TouchRegister(pParse, regRow + pFK->nCol);
        for(j=0; j<pFK->nCol; j++){
          int iCol = aiCols ? aiCols[j] : pFK->aCol[j].iFrom;
          sqlite3ExprCodeGetColumnOfTable(v, pTab, 0, iCol, regRow+j);
          sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);
        }

        /* Generate code to query the parent index for a matching parent

      int cnt = 0;     /* Number of entries in aRoot[] */
      int mxIdx = 0;   /* Maximum number of indexes for any table */

      if( OMIT_TEMPDB && i==1 ) continue;
      if( iDb>=0 && i!=iDb ) continue;

      sqlite3CodeVerifySchema(pParse, i);
      pParse->okConstFactor = 0;  /* tag-20230327-1 */

      /* Do an integrity check of the B-Tree
      **
      ** Begin by finding the root pages numbers
      ** for all tables and indices in the database.
      */
      assert( sqlite3SchemaMutexHeld(db, i, 0) );

        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          aRoot[++cnt] = pIdx->tnum;
        }
      }
      aRoot[0] = cnt;

      /* Make sure sufficient number of registers have been allocated */
      sqlite3TouchRegister(pParse, 8+mxIdx);
      sqlite3ClearTempRegCache(pParse);

      /* Do the b-tree integrity checks */
      sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);
      sqlite3VdbeChangeP5(v, (u8)i);
      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,

            }
          }

          labelError = sqlite3VdbeMakeLabel(pParse);
          labelOk = sqlite3VdbeMakeLabel(pParse);
          if( pCol->notNull ){
            /* (1) NOT NULL columns may not contain a NULL */
            int jmp3;
            int jmp2 = sqlite3VdbeAddOp4Int(v, OP_IsType, p1, labelOk, p3, p4);
            VdbeCoverage(v);
            if( p1<0 ){
              sqlite3VdbeChangeP5(v, 0x0f); /* INT, REAL, TEXT, or BLOB */
              jmp3 = jmp2;
            }else{
              sqlite3VdbeChangeP5(v, 0x0d); /* INT, TEXT, or BLOB */
              /* OP_IsType does not detect NaN values in the database file
              ** which should be treated as a NULL.  So if the header type
              ** is REAL, we have to load the actual data using OP_Column
              ** to reliably determine if the value is a NULL. */
              sqlite3VdbeAddOp3(v, OP_Column, p1, p3, 3);
              jmp3 = sqlite3VdbeAddOp2(v, OP_NotNull, 3, labelOk);
              VdbeCoverage(v);
            }
            zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,
                                pCol->zCnName);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
            if( doTypeCheck ){
              sqlite3VdbeGoto(v, labelError);
              sqlite3VdbeJumpHere(v, jmp2);
              sqlite3VdbeJumpHere(v, jmp3);
            }else{
              /* VDBE byte code will fall thru */
            }
          }
          if( bStrict && doTypeCheck ){
            /* (2) Datatype must be exact for non-ANY columns in STRICT tables*/
            static unsigned char aStdTypeMask[] = {

            ** that extracts the rowid off the end of the index record.
            ** But it only works correctly if index record does not have
            ** any extra bytes at the end.  Verify that this is the case. */
            if( HasRowid(pTab) ){
              int jmp7;
              sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur+j, 3);
              jmp7 = sqlite3VdbeAddOp3(v, OP_Eq, 3, 0, r1+pIdx->nColumn-1);
              VdbeCoverageNeverNull(v);
              sqlite3VdbeLoadString(v, 3,
                 "rowid not at end-of-record for row ");
              sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
              sqlite3VdbeLoadString(v, 4, " of index ");
              sqlite3VdbeGoto(v, jmp5-1);
              sqlite3VdbeJumpHere(v, jmp7);
            }

#ifndef SQLITE_OMIT_UTF16
      /* If opening the main database, set ENC(db). */
      encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
      if( encoding==0 ) encoding = SQLITE_UTF8;
#else
      encoding = SQLITE_UTF8;
#endif
      if( db->nVdbeActive>0 && encoding!=ENC(db)
       && (db->mDbFlags & DBFLAG_Vacuum)==0
      ){
        rc = SQLITE_LOCKED;
        goto initone_error_out;
      }else{
        sqlite3SetTextEncoding(db, encoding);
      }
    }else{
      /* If opening an attached database, the encoding much match ENC(db) */

  memset(PARSE_HDR(&sParse), 0, PARSE_HDR_SZ);
  memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ);
  sParse.pOuterParse = db->pParse;
  db->pParse = &sParse;
  sParse.db = db;
  sParse.pReprepare = pReprepare;
  assert( ppStmt && *ppStmt==0 );
  if( db->mallocFailed ){
    sqlite3ErrorMsg(&sParse, "out of memory");
    db->errCode = rc = SQLITE_NOMEM;
    goto end_prepare;
  }
  assert( sqlite3_mutex_held(db->mutex) );

  /* For a long-term use prepared statement avoid the use of
  ** lookaside memory.
  */
  if( prepFlags & SQLITE_PREPARE_PERSISTENT ){
    sParse.disableLookaside++;

  /* Three cases:
  **   (1) The data to be sorted has already been packed into a Record
  **       by a prior OP_MakeRecord.  In this case nData==1 and regData
  **       will be completely unrelated to regOrigData.
  **   (2) All output columns are included in the sort record.  In that
  **       case regData==regOrigData.
  **   (3) Some output columns are omitted from the sort record due to
  **       the SQLITE_ENABLE_SORTER_REFERENCES optimization, or due to the
  **       SQLITE_ECEL_OMITREF optimization, or due to the
  **       SortCtx.pDeferredRowLoad optimiation.  In any of these cases
  **       regOrigData is 0 to prevent this routine from trying to copy
  **       values that might not yet exist.
  */
  assert( nData==1 || regData==regOrigData || regOrigData==0 );

  struct ExprList_item *a;
  NameContext sNC;

  assert( pSelect!=0 );
  assert( (pSelect->selFlags & SF_Resolved)!=0 );
  assert( pTab->nCol==pSelect->pEList->nExpr || pParse->nErr>0 );
  assert( aff==SQLITE_AFF_NONE || aff==SQLITE_AFF_BLOB );
  if( db->mallocFailed || IN_RENAME_OBJECT ) return;
  while( pSelect->pPrior ) pSelect = pSelect->pPrior;
  a = pSelect->pEList->a;
  memset(&sNC, 0, sizeof(sNC));
  sNC.pSrcList = pSelect->pSrc;
  for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
    const char *zType;
    i64 n;

        zType = 0;
        for(j=1; j<SQLITE_N_STDTYPE; j++){
          if( sqlite3StdTypeAffinity[j]==pCol->affinity ){
            zType = sqlite3StdType[j];
            break;
          }
        }
      }
    }
    if( zType ){
      i64 m = sqlite3Strlen30(zType);
      n = sqlite3Strlen30(pCol->zCnName);
      pCol->zCnName = sqlite3DbReallocOrFree(db, pCol->zCnName, n+m+2);
      pCol->colFlags &= ~(COLFLAG_HASTYPE|COLFLAG_HASCOLL);
      if( pCol->zCnName ){
        memcpy(&pCol->zCnName[n+1], zType, m+1);
        pCol->colFlags |= COLFLAG_HASTYPE;



      }
    }
    pColl = sqlite3ExprCollSeq(pParse, p);
    if( pColl ){
      assert( pTab->pIndex==0 );
      sqlite3ColumnSetColl(db, pCol, pColl->zName);
    }

      Expr ifNullRow;
      assert( pSubst->pEList!=0 && iColumn<pSubst->pEList->nExpr );
      assert( pExpr->pRight==0 );
      if( sqlite3ExprIsVector(pCopy) ){
        sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
      }else{
        sqlite3 *db = pSubst->pParse->db;
        if( pSubst->isOuterJoin
         && (pCopy->op!=TK_COLUMN || pCopy->iTable!=pSubst->iNewTable)
        ){
          memset(&ifNullRow, 0, sizeof(ifNullRow));
          ifNullRow.op = TK_IF_NULL_ROW;
          ifNullRow.pLeft = pCopy;
          ifNullRow.iTable = pSubst->iNewTable;
          ifNullRow.iColumn = -99;
          ifNullRow.flags = EP_IfNullRow;
          pCopy = &ifNullRow;

**              (17d2) DISTINCT
**        (17e) the subquery may not contain window functions, and
**        (17f) the subquery must not be the RHS of a LEFT JOIN.
**        (17g) either the subquery is the first element of the outer
**              query or there are no RIGHT or FULL JOINs in any arm
**              of the subquery.  (This is a duplicate of condition (27b).)
**        (17h) The corresponding result set expressions in all arms of the
**              compound must have the same affinity.

**
**        The parent and sub-query may contain WHERE clauses. Subject to
**        rules (11), (13) and (14), they may also contain ORDER BY,
**        LIMIT and OFFSET clauses.  The subquery cannot use any compound
**        operator other than UNION ALL because all the other compound
**        operators have an implied DISTINCT which is disallowed by
**        restriction (4).

**       be materialized.  (This restriction is implemented in the calling
**       routine.)
**
**   (8) If the subquery is a compound that uses UNION, INTERSECT,
**       or EXCEPT, then all of the result set columns for all arms of
**       the compound must use the BINARY collating sequence.
**
**   (9) All three of the following are true:
**
**       (9a) The WHERE clause expression originates in the ON or USING clause
**            of a join (either an INNER or an OUTER join), and
**
**       (9b) The subquery is to the right of the ON/USING clause
**
**       (9c) There is a RIGHT JOIN (or FULL JOIN) in between the ON/USING
**            clause and the subquery.
**
**       Without this restriction, the push-down optimization might move
**       the ON/USING filter expression from the left side of a RIGHT JOIN
**       over to the right side, which leads to incorrect answers.  See
**       also restriction (6) in sqlite3ExprIsSingleTableConstraint().
**
**  (10) The inner query is not the right-hand table of a RIGHT JOIN.
**
**  (11) The subquery is not a VALUES clause
**
** Return 0 if no changes are made and non-zero if one or more WHERE clause
** terms are duplicated into the subquery.
*/
static int pushDownWhereTerms(
  Parse *pParse,        /* Parse context (for malloc() and error reporting) */
  Select *pSubq,        /* The subquery whose WHERE clause is to be augmented */
  Expr *pWhere,         /* The WHERE clause of the outer query */
  SrcList *pSrcList,    /* The complete from clause of the outer query */
  int iSrc              /* Which FROM clause term to try to push into  */
){
  Expr *pNew;
  SrcItem *pSrc;        /* The subquery FROM term into which WHERE is pushed */
  int nChng = 0;
  pSrc = &pSrcList->a[iSrc];
  if( pWhere==0 ) return 0;
  if( pSubq->selFlags & (SF_Recursive|SF_MultiPart) ){
    return 0;           /* restrictions (2) and (11) */
  }
  if( pSrc->fg.jointype & (JT_LTORJ|JT_RIGHT) ){
    return 0;           /* restrictions (10) */
  }

  if( pSubq->pPrior ){
    Select *pSel;
    int notUnionAll = 0;
    for(pSel=pSubq; pSel; pSel=pSel->pPrior){
      u8 op = pSel->op;
      assert( op==TK_ALL || op==TK_SELECT
           || op==TK_UNION || op==TK_INTERSECT || op==TK_EXCEPT );
      if( op!=TK_ALL && op!=TK_SELECT ){
        notUnionAll = 1;
      }
#ifndef SQLITE_OMIT_WINDOWFUNC
      if( pSel->pWin ) return 0;    /* restriction (6b) */
#endif
    }



    if( notUnionAll ){
      /* If any of the compound arms are connected using UNION, INTERSECT,
      ** or EXCEPT, then we must ensure that none of the columns use a
      ** non-BINARY collating sequence. */
      for(pSel=pSubq; pSel; pSel=pSel->pPrior){
        int ii;
        const ExprList *pList = pSel->pEList;

  }
#endif

  if( pSubq->pLimit!=0 ){
    return 0; /* restriction (3) */
  }
  while( pWhere->op==TK_AND ){
    nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight, pSrcList, iSrc);
    pWhere = pWhere->pLeft;
  }

#if 0 /* These checks now done by sqlite3ExprIsSingleTableConstraint() */
  if( ExprHasProperty(pWhere, EP_OuterON|EP_InnerON) /* (9a) */
   && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0     /* Fast pre-test of (9c) */
  ){
    int jj;
    for(jj=0; jj<iSrc; jj++){
      if( pWhere->w.iJoin==pSrcList->a[jj].iCursor ){
        /* If we reach this point, both (9a) and (9b) are satisfied.
        ** The following loop checks (9c):
        */
        for(jj++; jj<iSrc; jj++){
          if( (pSrcList->a[jj].fg.jointype & JT_RIGHT)!=0 ){
            return 0;  /* restriction (9) */
          }
        }
      }
    }
  }
  if( isLeftJoin
   && (ExprHasProperty(pWhere,EP_OuterON)==0
         || pWhere->w.iJoin!=iCursor)
  ){
    return 0; /* restriction (4) */
  }
  if( ExprHasProperty(pWhere,EP_OuterON)
   && pWhere->w.iJoin!=iCursor
  ){
    return 0; /* restriction (5) */
  }
#endif

  if( sqlite3ExprIsSingleTableConstraint(pWhere, pSrcList, iSrc) ){
    nChng++;
    pSubq->selFlags |= SF_PushDown;
    while( pSubq ){
      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      unsetJoinExpr(pNew, -1, 1);
      x.pParse = pParse;

      }
      pSubq = pSubq->pPrior;
    }
  }
  return nChng;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

/*
** Check to see if a subquery contains result-set columns that are
** never used.  If it does, change the value of those result-set columns
** to NULL so that they do not cause unnecessary work to compute.
**
** Return the number of column that were changed to NULL.
*/
static int disableUnusedSubqueryResultColumns(SrcItem *pItem){
  int nCol;
  Select *pSub;      /* The subquery to be simplified */
  Select *pX;        /* For looping over compound elements of pSub */
  Table *pTab;       /* The table that describes the subquery */
  int j;             /* Column number */
  int nChng = 0;     /* Number of columns converted to NULL */
  Bitmask colUsed;   /* Columns that may not be NULLed out */

  assert( pItem!=0 );
  if( pItem->fg.isCorrelated || pItem->fg.isCte ){
    return 0;
  }
  assert( pItem->pTab!=0 );
  pTab = pItem->pTab;
  assert( pItem->pSelect!=0 );
  pSub = pItem->pSelect;
  assert( pSub->pEList->nExpr==pTab->nCol );
  if( (pSub->selFlags & (SF_Distinct|SF_Aggregate))!=0 ){
    testcase( pSub->selFlags & SF_Distinct );
    testcase( pSub->selFlags & SF_Aggregate );
    return 0;
  }
  for(pX=pSub; pX; pX=pX->pPrior){
    if( pX->pPrior && pX->op!=TK_ALL ){
      /* This optimization does not work for compound subqueries that
      ** use UNION, INTERSECT, or EXCEPT.  Only UNION ALL is allowed. */
      return 0;
    }
#ifndef SQLITE_OMIT_WINDOWFUNC
    if( pX->pWin ){
      /* This optimization does not work for subqueries that use window
      ** functions. */
      return 0;
    }
#endif
  }
  colUsed = pItem->colUsed;
  if( pSub->pOrderBy ){
    ExprList *pList = pSub->pOrderBy;
    for(j=0; j<pList->nExpr; j++){
      u16 iCol = pList->a[j].u.x.iOrderByCol;
      if( iCol>0 ){
        iCol--;
        colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);
      }
    }
  }
  nCol = pTab->nCol;
  for(j=0; j<nCol; j++){
    Bitmask m = j<BMS-1 ? MASKBIT(j) : TOPBIT;
    if( (m & colUsed)!=0 ) continue;
    for(pX=pSub; pX; pX=pX->pPrior) {
      Expr *pY = pX->pEList->a[j].pExpr;
      if( pY->op==TK_NULL ) continue;
      pY->op = TK_NULL;
      ExprClearProperty(pY, EP_Skip|EP_Unlikely);
      pX->selFlags |= SF_PushDown;
      nChng++;
    }
  }
  return nChng;
}


/*
** The pFunc is the only aggregate function in the query.  Check to see
** if the query is a candidate for the min/max optimization.
**
** If the query is a candidate for the min/max optimization, then set
** *ppMinMax to be an ORDER BY clause to be used for the optimization

  NameContext *pNC        /* Name context used to resolve agg-func args */
){
  assert( pAggInfo->iFirstReg==0 );
  assert( pSelect!=0 );
  assert( pSelect->pGroupBy!=0 );
  pAggInfo->nColumn = pAggInfo->nAccumulator;
  if( ALWAYS(pAggInfo->nSortingColumn>0) ){

    int mx = pSelect->pGroupBy->nExpr - 1;

    int j, k;
    for(j=0; j<pAggInfo->nColumn; j++){
      k = pAggInfo->aCol[j].iSorterColumn;
      if( k>mx ) mx = k;
    }
    pAggInfo->nSortingColumn = mx+1;
  }
  analyzeAggFuncArgs(pAggInfo, pNC);
#if TREETRACE_ENABLED
  if( sqlite3TreeTrace & 0x20 ){
    IndexedExpr *pIEpr;
    TREETRACE(0x20, pParse, pSelect,
        ("AggInfo (possibly) adjusted for Indexed Exprs\n"));

  struct AggInfo_col *pCol;
  UNUSED_PARAMETER(pWalker);
  if( pExpr->pAggInfo==0 ) return WRC_Continue;
  if( pExpr->op==TK_AGG_COLUMN ) return WRC_Continue;
  if( pExpr->op==TK_AGG_FUNCTION ) return WRC_Continue;
  if( pExpr->op==TK_IF_NULL_ROW ) return WRC_Continue;
  pAggInfo = pExpr->pAggInfo;
  if( NEVER(pExpr->iAgg>=pAggInfo->nColumn) ) return WRC_Continue;
  assert( pExpr->iAgg>=0 );
  pCol = &pAggInfo->aCol[pExpr->iAgg];
  pExpr->op = TK_AGG_COLUMN;
  pExpr->iTable = pCol->iTable;
  pExpr->iColumn = pCol->iColumn;
  ExprClearProperty(pExpr, EP_Skip|EP_Collate);
  return WRC_Prune;
}

/*
** Convert every pAggInfo->aFunc[].pExpr such that any node within
** those expressions that has pAppInfo set is changed into a TK_AGG_COLUMN
** opcode.

*/
static void agginfoFree(sqlite3 *db, AggInfo *p){
  sqlite3DbFree(db, p->aCol);
  sqlite3DbFree(db, p->aFunc);
  sqlite3DbFreeNN(db, p);
}


/*
** Attempt to transform a query of the form
**
**    SELECT count(*) FROM (SELECT x FROM t1 UNION ALL SELECT y FROM t2)
**
** Into this:
**

  Select *pSub, *pPrior;
  Expr *pExpr;
  Expr *pCount;
  sqlite3 *db;
  if( (p->selFlags & SF_Aggregate)==0 ) return 0;   /* This is an aggregate */
  if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */
  if( p->pWhere ) return 0;
  if( p->pHaving ) return 0;
  if( p->pGroupBy ) return 0;
  if( p->pOrderBy ) return 0;
  pExpr = p->pEList->a[0].pExpr;
  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */
  assert( ExprUseUToken(pExpr) );
  if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0;  /* Is count() */
  assert( ExprUseXList(pExpr) );
  if( pExpr->x.pList!=0 ) return 0;                 /* Must be count(*) */
  if( p->pSrc->nSrc!=1 ) return 0;                  /* One table in FROM  */
  if( ExprHasProperty(pExpr, EP_WinFunc) ) return 0;/* Not a window function */
  pSub = p->pSrc->a[0].pSelect;
  if( pSub==0 ) return 0;                           /* The FROM is a subquery */
  if( pSub->pPrior==0 ) return 0;                   /* Must be a compound */
  if( pSub->selFlags & SF_CopyCte ) return 0;       /* Not a CTE */
  do{
    if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */
    if( pSub->pWhere ) return 0;                      /* No WHERE clause */
    if( pSub->pLimit ) return 0;                      /* No LIMIT clause */
    if( pSub->selFlags & SF_Aggregate ) return 0;     /* Not an aggregate */
    assert( pSub->pHaving==0 );  /* Due to the previous */
   pSub = pSub->pPrior;                              /* Repeat over compound */
  }while( pSub );

  /* If we reach this point then it is OK to perform the transformation */

  db = pParse->db;
  pCount = pExpr;
  pExpr = 0;

  if( sqlite3TreeTrace & 0x200 ){
    TREETRACE(0x200,pParse,p,("After count-of-view optimization:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif
  return 1;
}


/*
** If any term of pSrc, or any SF_NestedFrom sub-query, is not the same
** as pSrcItem but has the same alias as p0, then return true.
** Otherwise return false.
*/
static int sameSrcAlias(SrcItem *p0, SrcList *pSrc){

                ("LEFT-JOIN simplifies to JOIN on term %d\n",i));
      pItem->fg.jointype &= ~(JT_LEFT|JT_OUTER);
      assert( pItem->iCursor>=0 );
      unsetJoinExpr(p->pWhere, pItem->iCursor,
                    pTabList->a[0].fg.jointype & JT_LTORJ);
    }

    /* No futher action if this term of the FROM clause is not a subquery */
    if( pSub==0 ) continue;

    /* Catch mismatch in the declared columns of a view and the number of
    ** columns in the SELECT on the RHS */
    if( pTab->nCol!=pSub->pEList->nExpr ){
      sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
                      pTab->nCol, pTab->zName, pSub->pEList->nExpr);

      sqlite3TreeViewSelect(0, p, 0);
    }
#endif
  }else{
    TREETRACE(0x2000,pParse,p,("Constant propagation not helpful\n"));
  }


  if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)
   && countOfViewOptimization(pParse, p)
  ){
    if( db->mallocFailed ) goto select_end;
    pTabList = p->pSrc;
  }


  /* For each term in the FROM clause, do two things:
  ** (1) Authorized unreferenced tables
  ** (2) Generate code for all sub-queries
  */
  for(i=0; i<pTabList->nSrc; i++){
    SrcItem *pItem = &pTabList->a[i];

    /* Make copies of constant WHERE-clause terms in the outer query down
    ** inside the subquery.  This can help the subquery to run more efficiently.
    */
    if( OptimizationEnabled(db, SQLITE_PushDown)
     && (pItem->fg.isCte==0
         || (pItem->u2.pCteUse->eM10d!=M10d_Yes && pItem->u2.pCteUse->nUse<2))
     && pushDownWhereTerms(pParse, pSub, p->pWhere, pTabList, i)
    ){
#if TREETRACE_ENABLED
      if( sqlite3TreeTrace & 0x4000 ){
        TREETRACE(0x4000,pParse,p,
            ("After WHERE-clause push-down into subquery %d:\n", pSub->selId));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
      assert( pItem->pSelect && (pItem->pSelect->selFlags & SF_PushDown)!=0 );
    }else{
      TREETRACE(0x4000,pParse,p,("Push-down not possible\n"));
    }

    /* Convert unused result columns of the subquery into simple NULL
    ** expressions, to avoid unneeded searching and computation.
    */
    if( OptimizationEnabled(db, SQLITE_NullUnusedCols)
     && disableUnusedSubqueryResultColumns(pItem)
    ){
#if TREETRACE_ENABLED
      if( sqlite3TreeTrace & 0x4000 ){
        TREETRACE(0x4000,pParse,p,
            ("Change unused result columns to NULL for subquery %d:\n",
             pSub->selId));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
    }

    zSavedAuthContext = pParse->zAuthContext;
    pParse->zAuthContext = pItem->zName;

    /* Generate code to implement the subquery
    */
    if( fromClauseTermCanBeCoroutine(pParse, pTabList, i, p->selFlags) ){

  if( !IN_RENAME_OBJECT ){
    if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){
      if( !noErr ){
        sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
      }else{
        assert( !db->init.busy );
        sqlite3CodeVerifySchema(pParse, iDb);
        VVA_ONLY( pParse->ifNotExists = 1; )
      }
      goto trigger_cleanup;
    }
  }

  /* Do not create a trigger on a system table */
  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){

  int orconf           /* Default ON CONFLICT policy for trigger steps */
){
  const int op = pChanges ? TK_UPDATE : TK_DELETE;
  u32 mask = 0;
  Trigger *p;

  assert( isNew==1 || isNew==0 );
  if( IsView(pTab) ){
    return 0xffffffff;
  }
  for(p=pTrigger; p; p=p->pNext){
    if( p->op==op
     && (tr_tm&p->tr_tm)
     && checkColumnOverlap(p->pColumns,pChanges)
    ){
      if( p->bReturning ){
        mask = 0xffffffff;

    pLimit = 0;
  }
#endif

  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
    goto update_cleanup;
  }
  if( sqlite3IsReadOnly(pParse, pTab, pTrigger) ){
    goto update_cleanup;
  }

  /* Allocate a cursors for the main database table and for all indices.
  ** The index cursors might not be used, but if they are used they
  ** need to occur right after the database cursor.  So go ahead and
  ** allocate enough space, just in case.

      eOnePass = ONEPASS_SINGLE;
      sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL);
      bFinishSeek = 0;
    }else{
      /* Begin the database scan.
      **
      ** Do not consider a single-pass strategy for a multi-row update if
      ** there is anything that might disrupt the cursor being used to do
      ** the UPDATE:
      **   (1) This is a nested UPDATE
      **   (2) There are triggers
      **   (3) There are FOREIGN KEY constraints
      **   (4) There are REPLACE conflict handlers


      **   (5) There are subqueries in the WHERE clause
      */
      flags = WHERE_ONEPASS_DESIRED;
      if( !pParse->nested
       && !pTrigger
       && !hasFK
       && !chngKey
       && !bReplace
       && (sNC.ncFlags & NC_Subquery)==0
      ){
        flags |= WHERE_ONEPASS_MULTIROW;
      }
      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,0,0,flags,iIdxCur);
      if( pWInfo==0 ) goto update_cleanup;

      /* A one-pass strategy that might update more than one row may not
      ** be used if any column of the index used for the scan is being

  assert( &db->pVtabCtx );
  assert( xConstruct );
  sCtx.pTab = pTab;
  sCtx.pVTable = pVTable;
  sCtx.pPrior = db->pVtabCtx;
  sCtx.bDeclared = 0;
  db->pVtabCtx = &sCtx;
  pTab->nTabRef++;
  rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
  sqlite3DeleteTable(db, pTab);
  db->pVtabCtx = sCtx.pPrior;
  if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
  assert( sCtx.pTab==pTab );

  if( SQLITE_OK!=rc ){
    if( zErr==0 ){
      *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);

            xMethod = pMod->xRollbackTo;
            break;
          default:
            xMethod = pMod->xRelease;
            break;
        }
        if( xMethod && pVTab->iSavepoint>iSavepoint ){
          u64 savedFlags = (db->flags & SQLITE_Defensive);
          db->flags &= ~(u64)SQLITE_Defensive;
          rc = xMethod(pVTab->pVtab, iSavepoint);
          db->flags |= savedFlags;
        }
        sqlite3VtabUnlock(pVTab);
      }
    }
  }
  return rc;
}

      case SQLITE_VTAB_INNOCUOUS: {
        p->pVTable->eVtabRisk = SQLITE_VTABRISK_Low;
        break;
      }
      case SQLITE_VTAB_DIRECTONLY: {
        p->pVTable->eVtabRisk = SQLITE_VTABRISK_High;
        break;
      }
      case SQLITE_VTAB_USES_ALL_SCHEMAS: {
        p->pVTable->bAllSchemas = 1;
        break;
      }
      default: {
        rc = SQLITE_MISUSE_BKPT;
        break;
      }
    }
    va_end(ap);

    explainAppendTerm(pStr, pIndex, pLoop->u.btree.nTop, j, i, "<");
  }
  sqlite3_str_append(pStr, ")", 1);
}

/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
** command, or if stmt_scanstatus_v2() stats are enabled, or if SQLITE_DEBUG
** was defined at compile-time. If it is not a no-op, a single OP_Explain
** opcode is added to the output to describe the table scan strategy in pLevel.
**
** If an OP_Explain opcode is added to the VM, its address is returned.
** Otherwise, if no OP_Explain is coded, zero is returned.
*/
SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
  Parse *pParse,                  /* Parse context */
  SrcList *pTabList,              /* Table list this loop refers to */
  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
){
  int ret = 0;
#if !defined(SQLITE_DEBUG)
  if( sqlite3ParseToplevel(pParse)->explain==2 || IS_STMT_SCANSTATUS(pParse->db) )
#endif
  {
    SrcItem *pItem = &pTabList->a[pLevel->iFrom];
    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
    sqlite3 *db = pParse->db;     /* Database handle */
    int isSearch;                 /* True for a SEARCH. False for SCAN. */
    WhereLoop *pLoop;             /* The controlling WhereLoop object */

*/
SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
  int addrExplain                 /* Address of OP_Explain (or 0) */
){
  if( IS_STMT_SCANSTATUS( sqlite3VdbeDb(v) ) ){
    const char *zObj = 0;
    WhereLoop *pLoop = pLvl->pWLoop;
    int wsFlags = pLoop->wsFlags;
    int viaCoroutine = 0;

    if( (wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){
      zObj = pLoop->u.btree.pIndex->zName;
    }else{
      zObj = pSrclist->a[pLvl->iFrom].zName;
      viaCoroutine = pSrclist->a[pLvl->iFrom].fg.viaCoroutine;
    }
    sqlite3VdbeScanStatus(
        v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
    );

    if( viaCoroutine==0 ){
      if( (wsFlags & (WHERE_MULTI_OR|WHERE_AUTO_INDEX))==0 ){
        sqlite3VdbeScanStatusRange(v, addrExplain, -1, pLvl->iTabCur);
      }
      if( wsFlags & WHERE_INDEXED ){
        sqlite3VdbeScanStatusRange(v, addrExplain, -1, pLvl->iIdxCur);
      }
    }
  }
}
#endif


/*

** Also, if the node is a TK_COLUMN that does access the table idenified
** by pCCurHint.iTabCur, and an index is being used (which we will
** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into
** an access of the index rather than the original table.
*/
static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
  int rc = WRC_Continue;
  int reg;
  struct CCurHint *pHint = pWalker->u.pCCurHint;
  if( pExpr->op==TK_COLUMN ){
    if( pExpr->iTable!=pHint->iTabCur ){
      reg = ++pWalker->pParse->nMem;   /* Register for column value */
      reg = sqlite3ExprCodeTarget(pWalker->pParse, pExpr, reg);
      pExpr->op = TK_REGISTER;
      pExpr->iTable = reg;
    }else if( pHint->pIdx!=0 ){
      pExpr->iTable = pHint->iIdxCur;
      pExpr->iColumn = sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn);
      assert( pExpr->iColumn>=0 );
    }
  }else if( pExpr->pAggInfo ){
    rc = WRC_Prune;
    reg = ++pWalker->pParse->nMem;   /* Register for column value */
    reg = sqlite3ExprCodeTarget(pWalker->pParse, pExpr, reg);

    pExpr->op = TK_REGISTER;
    pExpr->iTable = reg;
  }else if( pExpr->op==TK_TRUEFALSE ){
    /* Do not walk disabled expressions.  tag-20230504-1 */

    return WRC_Prune;
  }
  return rc;
}

/*
** Insert an OP_CursorHint instruction if it is appropriate to do so.
*/

    }

    /* If we survive all prior tests, that means this term is worth hinting */
    pExpr = sqlite3ExprAnd(pParse, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
  }
  if( pExpr!=0 ){
    sWalker.xExprCallback = codeCursorHintFixExpr;
    if( pParse->nErr==0 ) sqlite3WalkExpr(&sWalker, pExpr);
    sqlite3VdbeAddOp4(v, OP_CursorHint,
                      (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
                      (const char*)pExpr, P4_EXPR);
  }
}
#else
# define codeCursorHint(A,B,C,D)  /* No-op */

        ** should we try before giving up and going with a seek.  The cost
        ** of a seek is proportional to the logarithm of the of the number
        ** of entries in the tree, so basing the number of steps to try
        ** on the estimated number of rows in the btree seems like a good
        ** guess. */
        addrSeekScan = sqlite3VdbeAddOp1(v, OP_SeekScan,
                                         (pIdx->aiRowLogEst[0]+9)/10);
        if( pRangeStart || pRangeEnd ){
          sqlite3VdbeChangeP5(v, 1);
          sqlite3VdbeChangeP2(v, addrSeekScan, sqlite3VdbeCurrentAddr(v)+1);
          addrSeekScan = 0;
        }
        VdbeCoverage(v);
      }
      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);

    /* Load the value for the inequality constraint at the end of the
    ** range (if any).
    */
    nConstraint = nEq;
    assert( pLevel->p2==0 );
    if( pRangeEnd ){
      Expr *pRight = pRangeEnd->pExpr->pRight;
      assert( addrSeekScan==0 );









      codeExprOrVector(pParse, pRight, regBase+nEq, nTop);
      whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
      if( (pRangeEnd->wtFlags & TERM_VNULL)==0
       && sqlite3ExprCanBeNull(pRight)
      ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
        VdbeCoverage(v);

      }
      nConstraint++;
    }
    if( zStartAff ) sqlite3DbNNFreeNN(db, zStartAff);
    if( zEndAff ) sqlite3DbNNFreeNN(db, zEndAff);

    /* Top of the loop body */
    pLevel->p2 = sqlite3VdbeCurrentAddr(v);

    /* Check if the index cursor is past the end of the range. */
    if( nConstraint ){
      if( regBignull ){
        /* Except, skip the end-of-range check while doing the NULL-scan */
        sqlite3VdbeAddOp2(v, OP_IfNot, regBignull, sqlite3VdbeCurrentAddr(v)+3);
        VdbeComment((v, "If NULL-scan 2nd pass"));

      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
    }else
    if( op==TK_ISNULL
     && !ExprHasProperty(pExpr,EP_OuterON)
     && 0==sqlite3ExprCanBeNull(pLeft)
    ){
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      pExpr->op = TK_TRUEFALSE;  /* See tag-20230504-1 */
      pExpr->u.zToken = "false";
      ExprSetProperty(pExpr, EP_IsFalse);
      pTerm->prereqAll = 0;
      pTerm->eOperator = 0;
    }
  }

    pColRef->iColumn = k++;
    assert( ExprUseYTab(pColRef) );
    pColRef->y.pTab = pTab;
    pItem->colUsed |= sqlite3ExprColUsed(pColRef);
    pRhs = sqlite3PExpr(pParse, TK_UPLUS,
        sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
    pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef, pRhs);
    if( pItem->fg.jointype & (JT_LEFT|JT_RIGHT) ){
      testcase( pItem->fg.jointype & JT_LEFT );  /* testtag-20230227a */
      testcase( pItem->fg.jointype & JT_RIGHT ); /* testtag-20230227b */
      joinType = EP_OuterON;
    }else{
      testcase( pItem->fg.jointype & JT_LTORJ ); /* testtag-20230227c */
      joinType = EP_InnerON;
    }
    sqlite3SetJoinExpr(pTerm, pItem->iCursor, joinType);
    whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);
  }
}

*/
static void explainAutomaticIndex(
  Parse *pParse,
  Index *pIdx,                    /* Automatic index to explain */
  int bPartial,                   /* True if pIdx is a partial index */
  int *pAddrExplain               /* OUT: Address of OP_Explain */
){
  if( IS_STMT_SCANSTATUS(pParse->db) && pParse->explain!=2 ){
    Table *pTab = pIdx->pTable;
    const char *zSep = "";
    char *zText = 0;
    int ii = 0;
    sqlite3_str *pStr = sqlite3_str_new(pParse->db);
    sqlite3_str_appendf(pStr,"CREATE AUTOMATIC INDEX ON %s(", pTab->zName);
    assert( pIdx->nColumn>1 );

/*
** Generate code to construct the Index object for an automatic index
** and to set up the WhereLevel object pLevel so that the code generator
** makes use of the automatic index.
*/
static SQLITE_NOINLINE void constructAutomaticIndex(
  Parse *pParse,              /* The parsing context */
  WhereClause *pWC,           /* The WHERE clause */

  const Bitmask notReady,     /* Mask of cursors that are not available */
  WhereLevel *pLevel          /* Write new index here */
){
  int nKeyCol;                /* Number of columns in the constructed index */
  WhereTerm *pTerm;           /* A single term of the WHERE clause */
  WhereTerm *pWCEnd;          /* End of pWC->a[] */
  Index *pIdx;                /* Object describing the transient index */
  Vdbe *v;                    /* Prepared statement under construction */
  int addrInit;               /* Address of the initialization bypass jump */
  Table *pTable;              /* The table being indexed */
  int addrTop;                /* Top of the index fill loop */
  int regRecord;              /* Register holding an index record */
  int n;                      /* Column counter */
  int i;                      /* Loop counter */
  int mxBitCol;               /* Maximum column in pSrc->colUsed */
  CollSeq *pColl;             /* Collating sequence to on a column */
  WhereLoop *pLoop;           /* The Loop object */
  char *zNotUsed;             /* Extra space on the end of pIdx */
  Bitmask idxCols;            /* Bitmap of columns used for indexing */
  Bitmask extraCols;          /* Bitmap of additional columns */
  u8 sentWarning = 0;         /* True if a warning has been issued */
  u8 useBloomFilter = 0;      /* True to also add a Bloom filter */
  Expr *pPartial = 0;         /* Partial Index Expression */
  int iContinue = 0;          /* Jump here to skip excluded rows */
  SrcList *pTabList;          /* The complete FROM clause */
  SrcItem *pSrc;              /* The FROM clause term to get the next index */
  int addrCounter = 0;        /* Address where integer counter is initialized */
  int regBase;                /* Array of registers where record is assembled */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  int addrExp = 0;            /* Address of OP_Explain */
#endif

  /* Generate code to skip over the creation and initialization of the
  ** transient index on 2nd and subsequent iterations of the loop. */
  v = pParse->pVdbe;
  assert( v!=0 );
  addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  /* Count the number of columns that will be added to the index
  ** and used to match WHERE clause constraints */
  nKeyCol = 0;
  pTabList = pWC->pWInfo->pTabList;
  pSrc = &pTabList->a[pLevel->iFrom];
  pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    Expr *pExpr = pTerm->pExpr;
    /* Make the automatic index a partial index if there are terms in the
    ** WHERE clause (or the ON clause of a LEFT join) that constrain which
    ** rows of the target table (pSrc) that can be used. */
    if( (pTerm->wtFlags & TERM_VIRTUAL)==0
     && sqlite3ExprIsSingleTableConstraint(pExpr, pTabList, pLevel->iFrom)
    ){
      pPartial = sqlite3ExprAnd(pParse, pPartial,
                                sqlite3ExprDup(pParse->db, pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol;
      Bitmask cMask;

  ** covering index.  A "covering index" is an index that contains all
  ** columns that are needed by the query.  With a covering index, the
  ** original table never needs to be accessed.  Automatic indices must
  ** be a covering index because the index will not be updated if the
  ** original table changes and the index and table cannot both be used
  ** if they go out of sync.
  */
  if( IsView(pTable) ){
    extraCols = ALLBITS;
  }else{
    extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
  }
  mxBitCol = MIN(BMS-1,pTable->nCol);
  testcase( pTable->nCol==BMS-1 );
  testcase( pTable->nCol==BMS-2 );
  for(i=0; i<mxBitCol; i++){
    if( extraCols & MASKBIT(i) ) nKeyCol++;
  }
  if( pSrc->colUsed & MASKBIT(BMS-1) ){

        Expr *pX = pTerm->pExpr;
        idxCols |= cMask;
        pIdx->aiColumn[n] = pTerm->u.x.leftColumn;
        pColl = sqlite3ExprCompareCollSeq(pParse, pX);
        assert( pColl!=0 || pParse->nErr>0 ); /* TH3 collate01.800 */
        pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;
        n++;
        if( ALWAYS(pX->pLeft!=0)
         && sqlite3ExprAffinity(pX->pLeft)!=SQLITE_AFF_TEXT
        ){
          /* TUNING: only use a Bloom filter on an automatic index
          ** if one or more key columns has the ability to hold numeric
          ** values, since strings all have the same hash in the Bloom
          ** filter implementation and hence a Bloom filter on a text column
          ** is not usually helpful. */
          useBloomFilter = 1;
        }
      }
    }
  }
  assert( (u32)n==pLoop->u.btree.nEq );

  /* Add additional columns needed to make the automatic index into
  ** a covering index */

  /* Create the automatic index */
  explainAutomaticIndex(pParse, pIdx, pPartial!=0, &addrExp);
  assert( pLevel->iIdxCur>=0 );
  pLevel->iIdxCur = pParse->nTab++;
  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
  VdbeComment((v, "for %s", pTable->zName));
  if( OptimizationEnabled(pParse->db, SQLITE_BloomFilter) && useBloomFilter ){
    sqlite3WhereExplainBloomFilter(pParse, pWC->pWInfo, pLevel);
    pLevel->regFilter = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Blob, 10000, pLevel->regFilter);
  }

  /* Fill the automatic index with content */
  assert( pSrc == &pWC->pWInfo->pTabList->a[pLevel->iFrom] );
  if( pSrc->fg.viaCoroutine ){
    int regYield = pSrc->regReturn;
    addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pSrc->addrFillSub);
    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
    VdbeCoverage(v);
    VdbeComment((v, "next row of %s", pSrc->pTab->zName));
  }else{
    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
  }
  if( pPartial ){
    iContinue = sqlite3VdbeMakeLabel(pParse);
    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
    pLoop->wsFlags |= WHERE_PARTIALIDX;
  }
  regRecord = sqlite3GetTempReg(pParse);
  regBase = sqlite3GenerateIndexKey(
      pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0
  );
  if( pLevel->regFilter ){
    sqlite3VdbeAddOp4Int(v, OP_FilterAdd, pLevel->regFilter, 0,
                         regBase, pLoop->u.btree.nEq);
  }
  sqlite3VdbeScanStatusCounters(v, addrExp, addrExp, sqlite3VdbeCurrentAddr(v));
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
  if( pSrc->fg.viaCoroutine ){
    sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
    testcase( pParse->db->mallocFailed );
    assert( pLevel->iIdxCur>0 );
    translateColumnToCopy(pParse, addrTop, pLevel->iTabCur,
                          pSrc->regResult, pLevel->iIdxCur);
    sqlite3VdbeGoto(v, addrTop);
    pSrc->fg.viaCoroutine = 0;
  }else{
    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
    sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
  }
  sqlite3VdbeJumpHere(v, addrTop);
  sqlite3ReleaseTempReg(pParse, regRecord);

  int addrCont;                        /* Jump here to skip a row */
  const WhereTerm *pTerm;              /* For looping over WHERE clause terms */
  const WhereTerm *pWCEnd;             /* Last WHERE clause term */
  Parse *pParse = pWInfo->pParse;      /* Parsing context */
  Vdbe *v = pParse->pVdbe;             /* VDBE under construction */
  WhereLoop *pLoop = pLevel->pWLoop;   /* The loop being coded */
  int iCur;                            /* Cursor for table getting the filter */
  IndexedExpr *saved_pIdxEpr;          /* saved copy of Parse.pIdxEpr */

  saved_pIdxEpr = pParse->pIdxEpr;
  pParse->pIdxEpr = 0;

  assert( pLoop!=0 );
  assert( v!=0 );
  assert( pLoop->wsFlags & WHERE_BLOOMFILTER );

  addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
  do{
    const SrcList *pTabList;
    const SrcItem *pItem;
    const Table *pTab;
    u64 sz;
    int iSrc;
    sqlite3WhereExplainBloomFilter(pParse, pWInfo, pLevel);
    addrCont = sqlite3VdbeMakeLabel(pParse);
    iCur = pLevel->iTabCur;
    pLevel->regFilter = ++pParse->nMem;

    /* The Bloom filter is a Blob held in a register.  Initialize it
    ** to zero-filled blob of at least 80K bits, but maybe more if the
    ** estimated size of the table is larger.  We could actually
    ** measure the size of the table at run-time using OP_Count with
    ** P3==1 and use that value to initialize the blob.  But that makes
    ** testing complicated.  By basing the blob size on the value in the
    ** sqlite_stat1 table, testing is much easier.
    */
    pTabList = pWInfo->pTabList;
    iSrc = pLevel->iFrom;
    pItem = &pTabList->a[iSrc];
    assert( pItem!=0 );
    pTab = pItem->pTab;
    assert( pTab!=0 );
    sz = sqlite3LogEstToInt(pTab->nRowLogEst);
    if( sz<10000 ){
      sz = 10000;
    }else if( sz>10000000 ){
      sz = 10000000;
    }
    sqlite3VdbeAddOp2(v, OP_Blob, (int)sz, pLevel->regFilter);

    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
    pWCEnd = &pWInfo->sWC.a[pWInfo->sWC.nTerm];
    for(pTerm=pWInfo->sWC.a; pTerm<pWCEnd; pTerm++){
      Expr *pExpr = pTerm->pExpr;
      if( (pTerm->wtFlags & TERM_VIRTUAL)==0
       && sqlite3ExprIsSingleTableConstraint(pExpr, pTabList, iSrc)
      ){
        sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
      }
    }
    if( pLoop->wsFlags & WHERE_IPK ){
      int r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);
      sqlite3VdbeAddOp4Int(v, OP_FilterAdd, pLevel->regFilter, 0, r1, 1);
      sqlite3ReleaseTempReg(pParse, r1);
    }else{
      Index *pIdx = pLoop->u.btree.pIndex;
      int n = pLoop->u.btree.nEq;
      int r1 = sqlite3GetTempRange(pParse, n);
      int jj;
      for(jj=0; jj<n; jj++){

        assert( pIdx->pTable==pItem->pTab );
        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iCur, jj, r1+jj);
      }
      sqlite3VdbeAddOp4Int(v, OP_FilterAdd, pLevel->regFilter, 0, r1, n);
      sqlite3ReleaseTempRange(pParse, r1, n);
    }
    sqlite3VdbeResolveLabel(v, addrCont);
    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1);
    VdbeCoverage(v);

        ** not able to do early evaluation of bloom filters that make use of
        ** the IN operator */
        break;
      }
    }
  }while( iLevel < pWInfo->nLevel );
  sqlite3VdbeJumpHere(v, addrOnce);
  pParse->pIdxEpr = saved_pIdxEpr;
}


#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Allocate and populate an sqlite3_index_info structure. It is the
** responsibility of the caller to eventually release the structure

      sqlite3OomFault(pParse->db);
    }else if( !pVtab->zErrMsg ){
      sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
    }else{
      sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
    }
  }
  if( pTab->u.vtab.p->bAllSchemas ){
    sqlite3VtabUsesAllSchemas(pParse);
  }
  sqlite3_free(pVtab->zErrMsg);
  pVtab->zErrMsg = 0;
  return rc;
}
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */

#ifdef SQLITE_ENABLE_STAT4

#ifndef SQLITE_DEBUG
  UNUSED_PARAMETER( pParse );
#endif
  assert( pRec!=0 );
  assert( pIdx->nSample>0 );
  assert( pRec->nField>0 );


  /* Do a binary search to find the first sample greater than or equal
  ** to pRec. If pRec contains a single field, the set of samples to search
  ** is simply the aSample[] array. If the samples in aSample[] contain more
  ** than one fields, all fields following the first are ignored.
  **
  ** If pRec contains N fields, where N is more than one, then as well as the

  ** equal to the previous sample in the array. For example, in the above,
  ** sample 2 is the first sample of a block of N samples, so at first it
  ** appears that it should be 1 field in size. However, that would make it
  ** smaller than sample 1, so the binary search would not work. As a result,
  ** it is extended to two fields. The duplicates that this creates do not
  ** cause any problems.
  */
  if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){
    nField = pIdx->nKeyCol;
  }else{
    nField = pIdx->nColumn;
  }
  nField = MIN(pRec->nField, nField);
  iCol = 0;
  iSample = pIdx->nSample * nField;
  do{
    int iSamp;                    /* Index in aSample[] of test sample */
    int n;                        /* Number of fields in test sample */

    iTest = (iMin+iSample)/2;

    }
  }
#else
  UNUSED_PARAMETER(pParse);
  UNUSED_PARAMETER(pBuilder);
  assert( pLower || pUpper );
#endif
  assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 || pParse->nErr>0 );
  nNew = whereRangeAdjust(pLower, nOut);
  nNew = whereRangeAdjust(pUpper, nNew);

  /* TUNING: If there is both an upper and lower limit and neither limit
  ** has an application-defined likelihood(), assume the range is
  ** reduced by an additional 75%. This means that, by default, an open-ended
  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the

*/
SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info *pIdxInfo){
  HiddenIndexInfo *pHidden = (HiddenIndexInfo*)&pIdxInfo[1];
  assert( pHidden->eDistinct>=0 && pHidden->eDistinct<=3 );
  return pHidden->eDistinct;
}



/*
** Cause the prepared statement that is associated with a call to
** xBestIndex to potentially use all schemas.  If the statement being
** prepared is read-only, then just start read transactions on all
** schemas.  But if this is a write operation, start writes on all
** schemas.
**
** This is used by the (built-in) sqlite_dbpage virtual table.
*/
SQLITE_PRIVATE void sqlite3VtabUsesAllSchemas(Parse *pParse){


  int nDb = pParse->db->nDb;
  int i;
  for(i=0; i<nDb; i++){
    sqlite3CodeVerifySchema(pParse, i);
  }
  if( DbMaskNonZero(pParse->writeMask) ){
    for(i=0; i<nDb; i++){
      sqlite3BeginWriteOperation(pParse, 0, i);
    }
  }
}


/*
** Add all WhereLoop objects for a table of the join identified by
** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
**
** If there are no LEFT or CROSS JOIN joins in the query, both mPrereq and
** mUnusable are set to 0. Otherwise, mPrereq is a mask of all FROM clause

  pWInfo->bOrderedInnerLoop = 0;
  if( pWInfo->pOrderBy ){
    pWInfo->nOBSat = pFrom->isOrdered;
    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
      if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
        pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
      }
      if( pWInfo->pSelect->pOrderBy
       && pWInfo->nOBSat > pWInfo->pSelect->pOrderBy->nExpr ){
        pWInfo->nOBSat = pWInfo->pSelect->pOrderBy->nExpr;
      }
    }else{
      pWInfo->revMask = pFrom->revLoop;
      if( pWInfo->nOBSat<=0 ){
        pWInfo->nOBSat = 0;
        if( nLoop>0 ){
          u32 wsFlags = pFrom->aLoop[nLoop-1]->wsFlags;
          if( (wsFlags & WHERE_ONEROW)==0

**   1) The query must not be an aggregate.
**   2) The table must be the RHS of a LEFT JOIN.
**   3) Either the query must be DISTINCT, or else the ON or USING clause
**      must contain a constraint that limits the scan of the table to
**      at most a single row.
**   4) The table must not be referenced by any part of the query apart
**      from its own USING or ON clause.
**   5) The table must not have an inner-join ON or USING clause if there is
**      a RIGHT JOIN anywhere in the query.  Otherwise the ON/USING clause
**      might move from the right side to the left side of the RIGHT JOIN.
**      Note: Due to (2), this condition can only arise if the table is
**      the right-most table of a subquery that was flattened into the
**      main query and that subquery was the right-hand operand of an
**      inner join that held an ON or USING clause.
**
** For example, given:
**
**     CREATE TABLE t1(ipk INTEGER PRIMARY KEY, v1);
**     CREATE TABLE t2(ipk INTEGER PRIMARY KEY, v2);
**     CREATE TABLE t3(ipk INTEGER PRIMARY KEY, v3);
**

*/
static SQLITE_NOINLINE Bitmask whereOmitNoopJoin(
  WhereInfo *pWInfo,
  Bitmask notReady
){
  int i;
  Bitmask tabUsed;
  int hasRightJoin;

  /* Preconditions checked by the caller */
  assert( pWInfo->nLevel>=2 );
  assert( OptimizationEnabled(pWInfo->pParse->db, SQLITE_OmitNoopJoin) );

  /* These two preconditions checked by the caller combine to guarantee
  ** condition (1) of the header comment */
  assert( pWInfo->pResultSet!=0 );
  assert( 0==(pWInfo->wctrlFlags & WHERE_AGG_DISTINCT) );

  tabUsed = sqlite3WhereExprListUsage(&pWInfo->sMaskSet, pWInfo->pResultSet);
  if( pWInfo->pOrderBy ){
    tabUsed |= sqlite3WhereExprListUsage(&pWInfo->sMaskSet, pWInfo->pOrderBy);
  }
  hasRightJoin = (pWInfo->pTabList->a[0].fg.jointype & JT_LTORJ)!=0;
  for(i=pWInfo->nLevel-1; i>=1; i--){
    WhereTerm *pTerm, *pEnd;
    SrcItem *pItem;
    WhereLoop *pLoop;
    pLoop = pWInfo->a[i].pWLoop;
    pItem = &pWInfo->pTabList->a[pLoop->iTab];
    if( (pItem->fg.jointype & (JT_LEFT|JT_RIGHT))!=JT_LEFT ) continue;

      if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){
        if( !ExprHasProperty(pTerm->pExpr, EP_OuterON)
         || pTerm->pExpr->w.iJoin!=pItem->iCursor
        ){
          break;
        }
      }
      if( hasRightJoin
       && ExprHasProperty(pTerm->pExpr, EP_InnerON)
       && pTerm->pExpr->w.iJoin==pItem->iCursor
      ){
        break;  /* restriction (5) */
      }
    }
    if( pTerm<pEnd ) continue;
    WHERETRACE(0xffffffff, ("-> drop loop %c not used\n", pLoop->cId));
    notReady &= ~pLoop->maskSelf;
    for(pTerm=pWInfo->sWC.a; pTerm<pEnd; pTerm++){
      if( (pTerm->prereqAll & pLoop->maskSelf)!=0 ){
        pTerm->wtFlags |= TERM_CODED;

  /* Analyze all of the subexpressions. */
  sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
  if( pSelect && pSelect->pLimit ){
    sqlite3WhereAddLimit(&pWInfo->sWC, pSelect);
  }
  if( pParse->nErr ) goto whereBeginError;

  /* The False-WHERE-Term-Bypass optimization:
  **
  ** If there are WHERE terms that are false, then no rows will be output,
  ** so skip over all of the code generated here.
  **
  ** Conditions:
  **
  **   (1)  The WHERE term must not refer to any tables in the join.
  **   (2)  The term must not come from an ON clause on the
  **        right-hand side of a LEFT or FULL JOIN.
  **   (3)  The term must not come from an ON clause, or there must be
  **        no RIGHT or FULL OUTER joins in pTabList.
  **   (4)  If the expression contains non-deterministic functions
  **        that are not within a sub-select. This is not required
  **        for correctness but rather to preserves SQLite's legacy
  **        behaviour in the following two cases:
  **
  **          WHERE random()>0;           -- eval random() once per row
  **          WHERE (SELECT random())>0;  -- eval random() just once overall
  **
  ** Note that the Where term need not be a constant in order for this
  ** optimization to apply, though it does need to be constant relative to
  ** the current subquery (condition 1).  The term might include variables
  ** from outer queries so that the value of the term changes from one
  ** invocation of the current subquery to the next.
  */
  for(ii=0; ii<sWLB.pWC->nBase; ii++){
    WhereTerm *pT = &sWLB.pWC->a[ii];  /* A term of the WHERE clause */
    Expr *pX;                          /* The expression of pT */
    if( pT->wtFlags & TERM_VIRTUAL ) continue;
    pX = pT->pExpr;
    assert( pX!=0 );
    assert( pT->prereqAll!=0 || !ExprHasProperty(pX, EP_OuterON) );
    if( pT->prereqAll==0                           /* Conditions (1) and (2) */
     && (nTabList==0 || exprIsDeterministic(pX))   /* Condition (4) */
     && !(ExprHasProperty(pX, EP_InnerON)          /* Condition (3) */
          && (pTabList->a[0].fg.jointype & JT_LTORJ)!=0 )
    ){
      sqlite3ExprIfFalse(pParse, pX, pWInfo->iBreak, SQLITE_JUMPIFNULL);
      pT->wtFlags |= TERM_CODED;
    }
  }

  if( wctrlFlags & WHERE_WANT_DISTINCT ){
    if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
      /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via

        Bitmask b = pTabItem->colUsed;
        int n = 0;
        for(; b; b=b>>1, n++){}
        sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(n), P4_INT32);
        assert( n<=pTab->nCol );
      }
#ifdef SQLITE_ENABLE_CURSOR_HINTS
      if( pLoop->u.btree.pIndex!=0 && (pTab->tabFlags & TF_WithoutRowid)==0 ){
        sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ|bFordelete);
      }else
#endif
      {
        sqlite3VdbeChangeP5(v, bFordelete);
      }
#ifdef SQLITE_ENABLE_COLUMN_USED_MASK

        sqlite3VdbeAddOp2(v, OP_Gosub, pSrc->regReturn, pSrc->addrFillSub);
      }else{
        int iOnce = sqlite3VdbeAddOp0(v, OP_Once);  VdbeCoverage(v);
        sqlite3VdbeAddOp2(v, OP_Gosub, pSrc->regReturn, pSrc->addrFillSub);
        sqlite3VdbeJumpHere(v, iOnce);
      }
    }
    assert( pTabList == pWInfo->pTabList );
    if( (wsFlags & (WHERE_AUTO_INDEX|WHERE_BLOOMFILTER))!=0 ){
      if( (wsFlags & WHERE_AUTO_INDEX)!=0 ){
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
        constructAutomaticIndex(pParse, &pWInfo->sWC, notReady, pLevel);

#endif
      }else{
        sqlite3ConstructBloomFilter(pWInfo, ii, pLevel, notReady);
      }
      if( db->mallocFailed ) goto whereBeginError;
    }
    addrExplain = sqlite3WhereExplainOneScan(

          }
          p = p->pIENext;
        }
      }
      k = pLevel->addrBody + 1;
#ifdef SQLITE_DEBUG
      if( db->flags & SQLITE_VdbeAddopTrace ){
        printf("TRANSLATE cursor %d->%d in opcode range %d..%d\n",
                pLevel->iTabCur, pLevel->iIdxCur, k, last-1);
      }
      /* Proof that the "+1" on the k value above is safe */
      pOp = sqlite3VdbeGetOp(v, k - 1);
      assert( pOp->opcode!=OP_Column || pOp->p1!=pLevel->iTabCur );
      assert( pOp->opcode!=OP_Rowid  || pOp->p1!=pLevel->iTabCur );
      assert( pOp->opcode!=OP_IfNullRow || pOp->p1!=pLevel->iTabCur );
#endif

            assert( pWin->pOwner==pExpr );
            return WRC_Prune;
          }
        }
      }
      /* no break */ deliberate_fall_through

    case TK_IF_NULL_ROW:
    case TK_AGG_FUNCTION:
    case TK_COLUMN: {
      int iCol = -1;
      if( pParse->db->mallocFailed ) return WRC_Abort;
      if( p->pSub ){
        int i;
        for(i=0; i<p->pSub->nExpr; i++){

#define sqlite3ParserARG_STORE
#define sqlite3ParserCTX_SDECL Parse *pParse;
#define sqlite3ParserCTX_PDECL ,Parse *pParse
#define sqlite3ParserCTX_PARAM ,pParse
#define sqlite3ParserCTX_FETCH Parse *pParse=yypParser->pParse;
#define sqlite3ParserCTX_STORE yypParser->pParse=pParse;
#define YYFALLBACK 1
#define YYNSTATE             575
#define YYNRULE              403
#define YYNRULE_WITH_ACTION  340
#define YYNTOKEN             185
#define YY_MAX_SHIFT         574
#define YY_MIN_SHIFTREDUCE   833
#define YY_MAX_SHIFTREDUCE   1235
#define YY_ERROR_ACTION      1236
#define YY_ACCEPT_ACTION     1237
#define YY_NO_ACTION         1238
#define YY_MIN_REDUCE        1239
#define YY_MAX_REDUCE        1641
/************* End control #defines *******************************************/
#define YY_NLOOKAHEAD ((int)(sizeof(yy_lookahead)/sizeof(yy_lookahead[0])))

/* Define the yytestcase() macro to be a no-op if is not already defined
** otherwise.
**
** Applications can choose to define yytestcase() in the %include section