SQLite Android Bindings

/******************************************************************************
** This file is an amalgamation of many separate C source files from SQLite
** version 3.27.0.  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

** 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        "3.27.0"
#define SQLITE_VERSION_NUMBER 3027000
#define SQLITE_SOURCE_ID      "2019-02-07 17:02:52 97744701c3bd414e6c9d7182639d8c2ce7cf124c4fce625071ae65658ac61713"

/*
** 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

** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
** layer a hint of how large the database file will grow to be during the
** current transaction.  This hint is not guaranteed to be accurate but it
** is often close.  The underlying VFS might choose to preallocate database
** file space based on this hint in order to help writes to the database
** file run faster.
**
** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
** implements [sqlite3_deserialize()] to set an upper bound on the size
** of the in-memory database.  The argument is a pointer to a [sqlite3_int64].
** If the integer pointed to is negative, then it is filled in with the
** current limit.  Otherwise the limit is set to the larger of the value
** of the integer pointed to and the current database size.  The integer
** pointed to is set to the new limit.
**
** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
** extends and truncates the database file in chunks of a size specified
** by the user. The fourth argument to [sqlite3_file_control()] should 
** point to an integer (type int) containing the new chunk-size to use
** for the nominated database. Allocating database file space in large
** chunks (say 1MB at a time), may reduce file-system fragmentation and

#define SQLITE_FCNTL_WIN32_GET_HANDLE       29
#define SQLITE_FCNTL_PDB                    30
#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE     31
#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
#define SQLITE_FCNTL_LOCK_TIMEOUT           34
#define SQLITE_FCNTL_DATA_VERSION           35
#define SQLITE_FCNTL_SIZE_LIMIT             36

/* deprecated names */
#define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
#define SQLITE_SET_LOCKPROXYFILE      SQLITE_FCNTL_SET_LOCKPROXYFILE
#define SQLITE_LAST_ERRNO             SQLITE_FCNTL_LAST_ERRNO

** than the configured sorter-reference size threshold - then a reference
** is stored in each sorted record and the required column values loaded
** from the database as records are returned in sorted order. The default
** value for this option is to never use this optimization. Specifying a 
** negative value for this option restores the default behaviour.
** This option is only available if SQLite is compiled with the
** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
**
** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
** [sqlite3_int64] parameter which is the default maximum size for an in-memory
** database created using [sqlite3_deserialize()].  This default maximum
** 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_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 */

/*
** CAPI3REF: Database Connection Configuration Options
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**

** ^The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  ^The profile callback contains
** the original statement text and an estimate of wall-clock time
** of how long that statement took to run.  ^The profile callback
** time is in units of nanoseconds, however the current implementation
** is only capable of millisecond resolution so the six least significant
** digits in the time are meaningless.  Future versions of SQLite
** might provide greater resolution on the profiler callback.  Invoking
** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
** profile callback.
*/
SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
   void(*xTrace)(void*,const char*), void*);
SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

/*

** zero is returned.
** 
** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
** is not a database file pathname pointer that SQLite passed into the xOpen
** VFS method, then the behavior of this routine is undefined and probably
** undesirable.
**
** See the [URI filename] documentation for additional information.
*/
SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);


/*

** and [sqlite3_prepare16_v3()] assume that the prepared statement will 
** be used just once or at most a few times and then destroyed using
** [sqlite3_finalize()] relatively soon. The current implementation acts
** on this hint by avoiding the use of [lookaside memory] so as not to
** deplete the limited store of lookaside memory. Future versions of
** SQLite may act on this hint differently.
**
** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used

** to be required for any prepared statement that wanted to use the
** [sqlite3_normalized_sql()] interface.  However, the
** [sqlite3_normalized_sql()] interface is now available to all
** prepared statements, regardless of whether or not they use this
** flag.
**
** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
** to return an error (error code SQLITE_ERROR) if the statement uses
** any virtual tables.
** </dl>
*/
#define SQLITE_PREPARE_PERSISTENT              0x01
#define SQLITE_PREPARE_NORMALIZE               0x02
#define SQLITE_PREPARE_NO_VTAB                 0x04

/*
** CAPI3REF: Compiling An SQL Statement
** KEYWORDS: {SQL statement compiler}
** METHOD: sqlite3
** CONSTRUCTOR: sqlite3_stmt
**

**
** If argument pzTab is not NULL, then *pzTab is set to point to a
** nul-terminated utf-8 encoded string containing the name of the table
** affected by the current change. The buffer remains valid until either
** sqlite3changeset_next() is called on the iterator or until the 
** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 
** set to the number of columns in the table affected by the change. If
** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
** is an indirect change, or false (0) otherwise. See the documentation for
** [sqlite3session_indirect()] for a description of direct and indirect
** changes. Finally, if pOp is not NULL, then *pOp is set to one of 
** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 
** type of change that the iterator currently points to.
**
** If no error occurs, SQLITE_OK is returned. If an error does occur, an

**   Query for the details of phrase match iIdx within the current row.
**   Phrase matches are numbered starting from zero, so the iIdx argument
**   should be greater than or equal to zero and smaller than the value
**   output by xInstCount().
**
**   Usually, output parameter *piPhrase is set to the phrase number, *piCol
**   to the column in which it occurs and *piOff the token offset of the




**   first token of the phrase. Returns SQLITE_OK if successful, or an error
**   code (i.e. SQLITE_NOMEM) if an error occurs.
**
**   This API can be quite slow if used with an FTS5 table created with the
**   "detail=none" or "detail=column" option. 
**
** xRowid:
**   Returns the rowid of the current row.
**

**            same token for inputs "first" and "1st". Say that token is in
**            fact "first", so that when the user inserts the document "I won
**            1st place" entries are added to the index for tokens "i", "won",
**            "first" and "place". If the user then queries for '1st + place',
**            the tokenizer substitutes "first" for "1st" and the query works
**            as expected.
**
**       <li> By querying the index for all synonyms of each query term
**            separately. In this case, when tokenizing query text, the
**            tokenizer may provide multiple synonyms for a single term 
**            within the document. FTS5 then queries the index for each 
**            synonym individually. For example, faced with the query:
**
**   <codeblock>
**     ... MATCH 'first place'</codeblock>
**
**            the tokenizer offers both "1st" and "first" as synonyms for the
**            first token in the MATCH query and FTS5 effectively runs a query 
**            similar to:

**            Using this method, when tokenizing document text, the tokenizer
**            provides multiple synonyms for each token. So that when a 
**            document such as "I won first place" is tokenized, entries are
**            added to the FTS index for "i", "won", "first", "1st" and
**            "place".
**
**            This way, even if the tokenizer does not provide synonyms
**            when tokenizing query text (it should not - to do so would be
**            inefficient), it doesn't matter if the user queries for 
**            'first + place' or '1st + place', as there are entries in the
**            FTS index corresponding to both forms of the first token.
**   </ol>
**
**   Whether it is parsing document or query text, any call to xToken that
**   specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit

SQLITE_PRIVATE i64 sqlite3BtreeIntegerKey(BtCursor*);
#ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
SQLITE_PRIVATE i64 sqlite3BtreeOffset(BtCursor*);
#endif
SQLITE_PRIVATE int sqlite3BtreePayload(BtCursor*, u32 offset, u32 amt, void*);
SQLITE_PRIVATE const void *sqlite3BtreePayloadFetch(BtCursor*, u32 *pAmt);
SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor*);
SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeMaxRecordSize(BtCursor*);

SQLITE_PRIVATE char *sqlite3BtreeIntegrityCheck(Btree*, int *aRoot, int nRoot, int, int*);
SQLITE_PRIVATE struct Pager *sqlite3BtreePager(Btree*);
SQLITE_PRIVATE i64 sqlite3BtreeRowCountEst(BtCursor*);

#ifndef SQLITE_OMIT_INCRBLOB
SQLITE_PRIVATE int sqlite3BtreePayloadChecked(BtCursor*, u32 offset, u32 amt, void*);

#   define COLNAME_N      1      /* Store only the name */
# else
#   define COLNAME_N      2      /* Store the name and decltype */
# endif
#endif

/*
** The following macro converts a label returned by sqlite3VdbeMakeLabel()
** into an index into the Parse.aLabel[] array that contains the resolved

** address of that label.
*/
#define ADDR(X)  (~(X))

/*
** The makefile scans the vdbe.c source file and creates the "opcodes.h"
** header file that defines a number for each opcode used by the VDBE.
*/
/************** Include opcodes.h in the middle of vdbe.h ********************/
/************** Begin file opcodes.h *****************************************/

# define ExplainQueryPlan(P)        sqlite3VdbeExplain P
# define ExplainQueryPlanPop(P)     sqlite3VdbeExplainPop(P)
# define ExplainQueryPlanParent(P)  sqlite3VdbeExplainParent(P)
#else
# define ExplainQueryPlan(P)
# define ExplainQueryPlanPop(P)
# define ExplainQueryPlanParent(P) 0
# define sqlite3ExplainBreakpoint(A,B) /*no-op*/
#endif
#if defined(SQLITE_DEBUG) && !defined(SQLITE_OMIT_EXPLAIN)
SQLITE_PRIVATE   void sqlite3ExplainBreakpoint(const char*,const char*);
#else
# define sqlite3ExplainBreakpoint(A,B) /*no-op*/
#endif
SQLITE_PRIVATE void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
SQLITE_PRIVATE void sqlite3VdbeChangeOpcode(Vdbe*, u32 addr, u8);
SQLITE_PRIVATE void sqlite3VdbeChangeP1(Vdbe*, u32 addr, int P1);
SQLITE_PRIVATE void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
SQLITE_PRIVATE void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
SQLITE_PRIVATE void sqlite3VdbeChangeP5(Vdbe*, u16 P5);
SQLITE_PRIVATE void sqlite3VdbeJumpHere(Vdbe*, int addr);
SQLITE_PRIVATE int sqlite3VdbeChangeToNoop(Vdbe*, int addr);
SQLITE_PRIVATE int sqlite3VdbeDeletePriorOpcode(Vdbe*, u8 op);
SQLITE_PRIVATE void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
SQLITE_PRIVATE void sqlite3VdbeAppendP4(Vdbe*, void *pP4, int p4type);
SQLITE_PRIVATE void sqlite3VdbeSetP4KeyInfo(Parse*, Index*);
SQLITE_PRIVATE void sqlite3VdbeUsesBtree(Vdbe*, int);
SQLITE_PRIVATE VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Parse*);
SQLITE_PRIVATE void sqlite3VdbeRunOnlyOnce(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeReusable(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeDelete(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeClearObject(sqlite3*,Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeMakeReady(Vdbe*,Parse*);
SQLITE_PRIVATE int sqlite3VdbeFinalize(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe*, int);
SQLITE_PRIVATE int sqlite3VdbeCurrentAddr(Vdbe*);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE   int sqlite3VdbeAssertMayAbort(Vdbe *, int);
#endif
SQLITE_PRIVATE void sqlite3VdbeResetStepResult(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeRewind(Vdbe*);
SQLITE_PRIVATE int sqlite3VdbeReset(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeSetNumCols(Vdbe*,int);
SQLITE_PRIVATE int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
SQLITE_PRIVATE void sqlite3VdbeCountChanges(Vdbe*);
SQLITE_PRIVATE sqlite3 *sqlite3VdbeDb(Vdbe*);
SQLITE_PRIVATE u8 sqlite3VdbePrepareFlags(Vdbe*);
SQLITE_PRIVATE void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
#ifdef SQLITE_ENABLE_NORMALIZE
SQLITE_PRIVATE void sqlite3VdbeAddDblquoteStr(sqlite3*,Vdbe*,const char*);
SQLITE_PRIVATE int sqlite3VdbeUsesDoubleQuotedString(Vdbe*,const char*);
#endif
SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe*,Vdbe*);
SQLITE_PRIVATE VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
SQLITE_PRIVATE sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
SQLITE_PRIVATE void sqlite3VdbeSetVarmask(Vdbe*, int);
#ifndef SQLITE_OMIT_TRACE
SQLITE_PRIVATE   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
#endif

                               const char*);
#endif

#ifndef SQLITE_OMIT_DEPRECATED
/* This is an extra SQLITE_TRACE macro that indicates "legacy" tracing
** in the style of sqlite3_trace()
*/
#define SQLITE_TRACE_LEGACY          0x40     /* Use the legacy xTrace */
#define SQLITE_TRACE_XPROFILE        0x80     /* Use the legacy xProfile */
#else
#define SQLITE_TRACE_LEGACY          0
#define SQLITE_TRACE_XPROFILE        0
#endif /* SQLITE_OMIT_DEPRECATED */
#define SQLITE_TRACE_NONLEGACY_MASK  0x0f     /* Normal flags */


/*
** Each database connection is an instance of the following structure.
*/
struct sqlite3 {
  sqlite3_vfs *pVfs;            /* OS Interface */

  int nVdbeWrite;               /* Number of active VDBEs that read and write */
  int nVdbeExec;                /* Number of nested calls to VdbeExec() */
  int nVDestroy;                /* Number of active OP_VDestroy operations */
  int nExtension;               /* Number of loaded extensions */
  void **aExtension;            /* Array of shared library handles */
  int (*xTrace)(u32,void*,void*,void*);     /* Trace function */
  void *pTraceArg;                          /* Argument to the trace function */
#ifndef SQLITE_OMIT_DEPRECATED
  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
  void *pProfileArg;                        /* Argument to profile function */
#endif
  void *pCommitArg;                 /* Argument to xCommitCallback() */
  int (*xCommitCallback)(void*);    /* Invoked at every commit. */
  void *pRollbackArg;               /* Argument to xRollbackCallback() */
  void (*xRollbackCallback)(void*); /* Invoked at every commit. */
  void *pUpdateArg;
  void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK

#define HI(X)  ((u64)(X)<<32)
#ifdef SQLITE_DEBUG
#define SQLITE_SqlTrace       HI(0x0001)  /* Debug print SQL as it executes */
#define SQLITE_VdbeListing    HI(0x0002)  /* Debug listings of VDBE progs */
#define SQLITE_VdbeTrace      HI(0x0004)  /* True to trace VDBE execution */
#define SQLITE_VdbeAddopTrace HI(0x0008)  /* Trace sqlite3VdbeAddOp() calls */
#define SQLITE_VdbeEQP        HI(0x0010)  /* Debug EXPLAIN QUERY PLAN */
#define SQLITE_ParserTrace    HI(0x0020)  /* PRAGMA parser_trace=ON */
#endif

/*
** Allowed values for sqlite3.mDbFlags
*/
#define DBFLAG_SchemaChange   0x0001  /* Uncommitted Hash table changes */
#define DBFLAG_PreferBuiltin  0x0002  /* Preference to built-in funcs */

/*
** The schema for each SQL table and view is represented in memory
** by an instance of the following structure.
*/
struct Table {
  char *zName;         /* Name of the table or view */
  Column *aCol;        /* Information about each column */



  Index *pIndex;       /* List of SQL indexes on this table. */
  Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
  FKey *pFKey;         /* Linked list of all foreign keys in this table */
  char *zColAff;       /* String defining the affinity of each column */
  ExprList *pCheck;    /* All CHECK constraints */
                       /*   ... also used as column name list in a VIEW */
  int tnum;            /* Root BTree page for this table */

  Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
  ExprList *aColExpr;      /* Column expressions */
  int tnum;                /* DB Page containing root of this index */
  LogEst szIdxRow;         /* Estimated average row size in bytes */
  u16 nKeyCol;             /* Number of columns forming the key */
  u16 nColumn;             /* Number of columns stored in the index */
  u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
  unsigned idxType:2;      /* 0:Normal 1:UNIQUE, 2:PRIMARY KEY, 3:IPK */
  unsigned bUnordered:1;   /* Use this index for == or IN queries only */
  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
  unsigned isResized:1;    /* True if resizeIndexObject() has been called */
  unsigned isCovering:1;   /* True if this is a covering index */
  unsigned noSkipScan:1;   /* Do not try to use skip-scan if true */
  unsigned hasStat1:1;     /* aiRowLogEst values come from sqlite_stat1 */
  unsigned bNoQuery:1;     /* Do not use this index to optimize queries */

/*
** Allowed values for Index.idxType
*/
#define SQLITE_IDXTYPE_APPDEF      0   /* Created using CREATE INDEX */
#define SQLITE_IDXTYPE_UNIQUE      1   /* Implements a UNIQUE constraint */
#define SQLITE_IDXTYPE_PRIMARYKEY  2   /* Is the PRIMARY KEY for the table */
#define SQLITE_IDXTYPE_IPK         3   /* INTEGER PRIMARY KEY index */

/* Return true if index X is a PRIMARY KEY index */
#define IsPrimaryKeyIndex(X)  ((X)->idxType==SQLITE_IDXTYPE_PRIMARYKEY)

/* Return true if index X is a UNIQUE index */
#define IsUniqueIndex(X)      ((X)->onError!=OE_None)

                         ** TK_COLUMN: the value of p5 for OP_Column
                         ** TK_AGG_FUNCTION: nesting depth */
  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  union {
    Table *pTab;           /* TK_COLUMN: Table containing column. Can be NULL
                           ** for a column of an index on an expression */
    Window *pWin;          /* TK_FUNCTION: Window definition for the func */
    struct {               /* TK_IN, TK_SELECT, and TK_EXISTS */
      int iAddr;             /* Subroutine entry address */
      int regReturn;         /* Register used to hold return address */
    } sub;
  } y;
};

/*
** The following are the meanings of bits in the Expr.flags field.
*/
#define EP_FromJoin  0x000001 /* Originates in ON/USING clause of outer join */

#define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
#define EP_Alias     0x400000 /* Is an alias for a result set column */
#define EP_Leaf      0x800000 /* Expr.pLeft, .pRight, .u.pSelect all NULL */
#define EP_WinFunc  0x1000000 /* TK_FUNCTION with Expr.y.pWin set */
#define EP_Subrtn   0x2000000 /* Uses Expr.y.sub. TK_IN, _SELECT, or _EXISTS */
#define EP_Quoted   0x4000000 /* TK_ID was originally quoted */

/*
** The EP_Propagate mask is a set of properties that automatically propagate
** upwards into parent nodes.
*/
#define EP_Propagate (EP_Collate|EP_Subquery|EP_HasFunc)

  u8 nested;           /* Number of nested calls to the parser/code generator */
  u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
  u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
  u8 mayAbort;         /* True if statement may throw an ABORT exception */
  u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
  u8 okConstFactor;    /* OK to factor out constants */
  u8 disableLookaside; /* Number of times lookaside has been disabled */
  u8 disableVtab;      /* Disable all virtual tables for this parse */
  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
                       ** of the base register during check-constraint eval */
  int nLabel;          /* The *negative* of the number of labels used */
  int nLabelAlloc;     /* Number of slots in aLabel */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */
  yDbMask writeMask;   /* Start a write transaction on these databases */
  yDbMask cookieMask;  /* Bitmask of schema verified databases */
  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
  int regRoot;         /* Register holding root page number for new objects */

#ifndef SQLITE_OMIT_EXPLAIN
  int addrExplain;          /* Address of current OP_Explain opcode */
#endif
  VList *pVList;            /* Mapping between variable names and numbers */
  Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
  const char *zTail;        /* All SQL text past the last semicolon parsed */
  Table *pNewTable;         /* A table being constructed by CREATE TABLE */
  Index *pNewIndex;         /* An index being constructed by CREATE INDEX.
                            ** Also used to hold redundant UNIQUE constraints
                            ** during a RENAME COLUMN */
  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Token sArg;               /* Complete text of a module argument */
  Table **apVtabLock;       /* Pointer to virtual tables needing locking */
#endif
  Table *pZombieTab;        /* List of Table objects to delete after code gen */

*/
typedef struct {
  sqlite3 *db;        /* The database being initialized */
  char **pzErrMsg;    /* Error message stored here */
  int iDb;            /* 0 for main database.  1 for TEMP, 2.. for ATTACHed */
  int rc;             /* Result code stored here */
  u32 mInitFlags;     /* Flags controlling error messages */
  u32 nInitRow;       /* Number of rows processed */
} InitData;

/*
** Allowed values for mInitFlags
*/
#define INITFLAG_AlterTable   0x0001  /* This is a reparse after ALTER TABLE */

#ifdef SQLITE_VDBE_COVERAGE
  /* The following callback (if not NULL) is invoked on every VDBE branch
  ** operation.  Set the callback using SQLITE_TESTCTRL_VDBE_COVERAGE.
  */
  void (*xVdbeBranch)(void*,unsigned iSrcLine,u8 eThis,u8 eMx);  /* Callback */
  void *pVdbeBranchArg;                                     /* 1st argument */
#endif
#ifdef SQLITE_ENABLE_DESERIALIZE
  sqlite3_int64 mxMemdbSize;        /* Default max memdb size */
#endif
#ifndef SQLITE_UNTESTABLE
  int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */
#endif
  int bLocaltimeFault;              /* True to fail localtime() calls */
  int bInternalFunctions;           /* Internal SQL functions are visible */
  int iOnceResetThreshold;          /* When to reset OP_Once counters */
  u32 szSorterRef;                  /* Min size in bytes to use sorter-refs */

#endif
#endif


SQLITE_PRIVATE void sqlite3SetString(char **, sqlite3*, const char*);
SQLITE_PRIVATE void sqlite3ErrorMsg(Parse*, const char*, ...);
SQLITE_PRIVATE void sqlite3Dequote(char*);
SQLITE_PRIVATE void sqlite3DequoteExpr(Expr*);
SQLITE_PRIVATE void sqlite3TokenInit(Token*,char*);
SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char*, int);
SQLITE_PRIVATE int sqlite3RunParser(Parse*, const char*, 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 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
SQLITE_PRIVATE ExprList *sqlite3ExprListAppendVector(Parse*,ExprList*,IdList*,Expr*);
SQLITE_PRIVATE void sqlite3ExprListSetSortOrder(ExprList*,int);
SQLITE_PRIVATE void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
SQLITE_PRIVATE void sqlite3ExprListSetSpan(Parse*,ExprList*,const char*,const char*);
SQLITE_PRIVATE void sqlite3ExprListDelete(sqlite3*, ExprList*);
SQLITE_PRIVATE u32 sqlite3ExprListFlags(const ExprList*);
SQLITE_PRIVATE int sqlite3IndexHasDuplicateRootPage(Index*);
SQLITE_PRIVATE int sqlite3Init(sqlite3*, char**);
SQLITE_PRIVATE int sqlite3InitCallback(void*, int, char**, char**);
SQLITE_PRIVATE int sqlite3InitOne(sqlite3*, int, char**, u32);
SQLITE_PRIVATE void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
#ifndef SQLITE_OMIT_VIRTUALTABLE
SQLITE_PRIVATE Module *sqlite3PragmaVtabRegister(sqlite3*,const char *zName);
#endif

SQLITE_PRIVATE void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
SQLITE_PRIVATE void sqlite3AddCheckConstraint(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3AddDefaultValue(Parse*,Expr*,const char*,const char*);
SQLITE_PRIVATE void sqlite3AddCollateType(Parse*, Token*);
SQLITE_PRIVATE void sqlite3EndTable(Parse*,Token*,Token*,u8,Select*);
SQLITE_PRIVATE int sqlite3ParseUri(const char*,const char*,unsigned int*,
                    sqlite3_vfs**,char**,char **);
#ifdef SQLITE_HAS_CODEC
SQLITE_PRIVATE   int sqlite3CodecQueryParameters(sqlite3*,const char*,const char*);
#else
# define sqlite3CodecQueryParameters(A,B,C) 0
#endif
SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3*,const char*);

#ifdef SQLITE_UNTESTABLE
# define sqlite3FaultSim(X) SQLITE_OK
#else
SQLITE_PRIVATE   int sqlite3FaultSim(int);
#endif

# define sqlite3AutoincrementBegin(X)
# define sqlite3AutoincrementEnd(X)
#endif
SQLITE_PRIVATE void sqlite3Insert(Parse*, SrcList*, Select*, IdList*, int, Upsert*);
SQLITE_PRIVATE void *sqlite3ArrayAllocate(sqlite3*,void*,int,int*,int*);
SQLITE_PRIVATE IdList *sqlite3IdListAppend(Parse*, IdList*, Token*);
SQLITE_PRIVATE int sqlite3IdListIndex(IdList*,const char*);
SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(Parse*, SrcList*, int, int);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(Parse*, SrcList*, Token*, Token*);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
                                      Token*, Select*, Expr*, IdList*);
SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);
SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *, struct SrcList_item *);
SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList*);
SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);

#define LOCATE_VIEW    0x01
#define LOCATE_NOERR   0x02
SQLITE_PRIVATE Table *sqlite3LocateTable(Parse*,u32 flags,const char*, const char*);
SQLITE_PRIVATE Table *sqlite3LocateTableItem(Parse*,u32 flags,struct SrcList_item *);
SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
SQLITE_PRIVATE void sqlite3Vacuum(Parse*,Token*,Expr*);
SQLITE_PRIVATE int sqlite3RunVacuum(char**, sqlite3*, int, sqlite3_value*);
SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3*, Token*);
SQLITE_PRIVATE int sqlite3ExprCompare(Parse*,Expr*, Expr*, int);
SQLITE_PRIVATE int sqlite3ExprCompareSkip(Expr*, Expr*, int);
SQLITE_PRIVATE int sqlite3ExprListCompare(ExprList*, ExprList*, int);
SQLITE_PRIVATE int sqlite3ExprImpliesExpr(Parse*,Expr*, Expr*, int);
SQLITE_PRIVATE int sqlite3ExprImpliesNonNullRow(Expr*,int);
SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);

#ifdef SQLITE_ENABLE_CURSOR_HINTS
SQLITE_PRIVATE int sqlite3ExprContainsSubquery(Expr*);
#endif
SQLITE_PRIVATE int sqlite3ExprIsInteger(Expr*, int*);
SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr*);
SQLITE_PRIVATE int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
SQLITE_PRIVATE int sqlite3IsRowid(const char*);



SQLITE_PRIVATE void sqlite3GenerateRowDelete(
    Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);
SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*, int);
SQLITE_PRIVATE int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*,Index*,int);
SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse*,int);
SQLITE_PRIVATE int sqlite3ExprReferencesUpdatedColumn(Expr*,int*,int);
SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,

SQLITE_PRIVATE void sqlite3UniqueConstraint(Parse*, int, Index*);
SQLITE_PRIVATE void sqlite3RowidConstraint(Parse*, int, Table*);
SQLITE_PRIVATE Expr *sqlite3ExprDup(sqlite3*,Expr*,int);
SQLITE_PRIVATE ExprList *sqlite3ExprListDup(sqlite3*,ExprList*,int);
SQLITE_PRIVATE SrcList *sqlite3SrcListDup(sqlite3*,SrcList*,int);
SQLITE_PRIVATE IdList *sqlite3IdListDup(sqlite3*,IdList*);
SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3*,Select*,int);

SQLITE_PRIVATE FuncDef *sqlite3FunctionSearch(int,const char*);

SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(FuncDef*,int);
SQLITE_PRIVATE FuncDef *sqlite3FindFunction(sqlite3*,const char*,int,u8,u8);
SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void);
SQLITE_PRIVATE void sqlite3RegisterDateTimeFunctions(void);
SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3*);
SQLITE_PRIVATE int sqlite3SafetyCheckOk(sqlite3*);
SQLITE_PRIVATE int sqlite3SafetyCheckSickOrOk(sqlite3*);

#endif
SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3*, int, int, int);
SQLITE_PRIVATE void sqlite3Reindex(Parse*, Token*, Token*);
SQLITE_PRIVATE void sqlite3AlterFunctions(void);
SQLITE_PRIVATE void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
SQLITE_PRIVATE void sqlite3AlterRenameColumn(Parse*, SrcList*, Token*, Token*);
SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *, int *);



SQLITE_PRIVATE void sqlite3NestedParse(Parse*, const char*, ...);
SQLITE_PRIVATE void sqlite3ExpirePreparedStatements(sqlite3*, int);
SQLITE_PRIVATE void sqlite3CodeRhsOfIN(Parse*, Expr*, int, int);
SQLITE_PRIVATE int sqlite3CodeSubselect(Parse*, Expr*);
SQLITE_PRIVATE void sqlite3SelectPrep(Parse*, Select*, NameContext*);
SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
SQLITE_PRIVATE int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
SQLITE_PRIVATE int sqlite3ResolveExprNames(NameContext*, Expr*);
SQLITE_PRIVATE int sqlite3ResolveExprListNames(NameContext*, ExprList*);
SQLITE_PRIVATE void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
SQLITE_PRIVATE int sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);
SQLITE_PRIVATE int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
SQLITE_PRIVATE void sqlite3AlterFinishAddColumn(Parse *, Token *);
SQLITE_PRIVATE void sqlite3AlterBeginAddColumn(Parse *, SrcList *);
SQLITE_PRIVATE void *sqlite3RenameTokenMap(Parse*, void*, Token*);
SQLITE_PRIVATE void sqlite3RenameTokenRemap(Parse*, void *pTo, void *pFrom);
SQLITE_PRIVATE void sqlite3RenameExprUnmap(Parse*, Expr*);

SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *, VTable *);
SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(sqlite3 *,FuncDef*, int nArg, Expr*);
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 sqlite3ParserReset(Parse*);
#ifdef SQLITE_ENABLE_NORMALIZE
SQLITE_PRIVATE char *sqlite3Normalize(Vdbe*, const char*);
#endif
SQLITE_PRIVATE int sqlite3Reprepare(Vdbe*);
SQLITE_PRIVATE void sqlite3ExprListCheckLength(Parse*, ExprList*, const char*);
SQLITE_PRIVATE CollSeq *sqlite3BinaryCompareCollSeq(Parse *, Expr *, Expr *);
SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3*);
SQLITE_PRIVATE const char *sqlite3JournalModename(int);
#ifndef SQLITE_OMIT_WAL

#define IN_INDEX_NOOP         5   /* No table available. Use comparisons */
/*
** Allowed flags for the 3rd parameter to sqlite3FindInIndex().
*/
#define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
#define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
#define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
SQLITE_PRIVATE int sqlite3FindInIndex(Parse *, Expr *, u32, int*, int*, int*);

SQLITE_PRIVATE int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
SQLITE_PRIVATE int sqlite3JournalSize(sqlite3_vfs *);
#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
 || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
SQLITE_PRIVATE   int sqlite3JournalCreate(sqlite3_file *);
#endif

** sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE);
*/
#ifndef SQLITE_DEFAULT_LOOKASIDE
# define SQLITE_DEFAULT_LOOKASIDE 1200,100
#endif


/* The default maximum size of an in-memory database created using
** sqlite3_deserialize()
*/
#ifndef SQLITE_MEMDB_DEFAULT_MAXSIZE
# define SQLITE_MEMDB_DEFAULT_MAXSIZE 1073741824
#endif

/*
** The following singleton contains the global configuration for
** the SQLite library.
*/
SQLITE_PRIVATE SQLITE_WSD struct Sqlite3Config sqlite3Config = {
   SQLITE_DEFAULT_MEMSTATUS,  /* bMemstat */
   1,                         /* bCoreMutex */

   0,                         /* xSqllog */
   0,                         /* pSqllogArg */
#endif
#ifdef SQLITE_VDBE_COVERAGE
   0,                         /* xVdbeBranch */
   0,                         /* pVbeBranchArg */
#endif
#ifdef SQLITE_ENABLE_DESERIALIZE
   SQLITE_MEMDB_DEFAULT_MAXSIZE,   /* mxMemdbSize */
#endif
#ifndef SQLITE_UNTESTABLE
   0,                         /* xTestCallback */
#endif
   0,                         /* bLocaltimeFault */
   0,                         /* bInternalFunctions */
   0x7ffffffe,                /* iOnceResetThreshold */
   SQLITE_DEFAULT_SORTERREF_SIZE,   /* szSorterRef */
};

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

};

/* A bitfield type for use inside of structures.  Always follow with :N where
** N is the number of bits.
*/
typedef unsigned bft;  /* Bit Field Type */

/* The ScanStatus object holds a single value for the
** sqlite3_stmt_scanstatus() interface.
*/
typedef struct ScanStatus ScanStatus;
struct ScanStatus {
  int addrExplain;                /* OP_Explain for loop */
  int addrLoop;                   /* Address of "loops" counter */
  int addrVisit;                  /* Address of "rows visited" counter */
  int iSelectID;                  /* The "Select-ID" for this loop */
  LogEst nEst;                    /* Estimated output rows per loop */
  char *zName;                    /* Name of table or index */
};

/* The DblquoteStr object holds the text of a double-quoted
** string for a prepared statement.  A linked list of these objects
** is constructed during statement parsing and is held on Vdbe.pDblStr.
** When computing a normalized SQL statement for an SQL statement, that
** list is consulted for each double-quoted identifier to see if the
** identifier should really be a string literal.
*/
typedef struct DblquoteStr DblquoteStr;
struct DblquoteStr {
  DblquoteStr *pNextStr;   /* Next string literal in the list */
  char z[8];               /* Dequoted value for the string */
};

/*
** An instance of the virtual machine.  This structure contains the complete
** state of the virtual machine.
**
** The "sqlite3_stmt" structure pointer that is returned by sqlite3_prepare()
** is really a pointer to an instance of this structure.
*/
struct Vdbe {
  sqlite3 *db;            /* The database connection that owns this statement */
  Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
  Parse *pParse;          /* Parsing context used to create this Vdbe */
  ynVar nVar;             /* Number of entries in aVar[] */
  u32 magic;              /* Magic number for sanity checking */
  int nMem;               /* Number of memory locations currently allocated */
  int nCursor;            /* Number of slots in apCsr[] */
  u32 cacheCtr;           /* VdbeCursor row cache generation counter */
  int pc;                 /* The program counter */
  int rc;                 /* Value to return */
  int nChange;            /* Number of db changes made since last reset */
  int iStatement;         /* Statement number (or 0 if has no opened stmt) */
  i64 iCurrentTime;       /* Value of julianday('now') for this statement */
  i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
  i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
  Mem *aMem;              /* The memory locations */
  Mem **apArg;            /* Arguments to currently executing user function */
  VdbeCursor **apCsr;     /* One element of this array for each open cursor */
  Mem *aVar;              /* Values for the OP_Variable opcode. */

  /* When allocating a new Vdbe object, all of the fields below should be
  ** initialized to zero or NULL */

  Op *aOp;                /* Space to hold the virtual machine's program */
  int nOp;                /* Number of instructions in the program */
  int nOpAlloc;           /* Slots allocated for aOp[] */
  Mem *aColName;          /* Column names to return */
  Mem *pResultSet;        /* Pointer to an array of results */
  char *zErrMsg;          /* Error message written here */


  VList *pVList;          /* Name of variables */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */
#endif

#ifdef SQLITE_DEBUG
  int rcApp;              /* errcode set by sqlite3_result_error_code() */
  u32 nWrite;             /* Number of write operations that have occurred */
#endif
  u16 nResColumn;         /* Number of columns in one row of the result set */
  u8 errorAction;         /* Recovery action to do in case of an error */
  u8 minWriteFileFormat;  /* Minimum file format for writable database files */

  bft bIsReader:1;        /* True for statements that read */
  yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
  yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
  u32 aCounter[7];        /* Counters used by sqlite3_stmt_status() */
  char *zSql;             /* Text of the SQL statement that generated this */
#ifdef SQLITE_ENABLE_NORMALIZE
  char *zNormSql;         /* Normalization of the associated SQL statement */
  DblquoteStr *pDblStr;   /* List of double-quoted string literals */
#endif
  void *pFree;            /* Free this when deleting the vdbe */
  VdbeFrame *pFrame;      /* Parent frame */
  VdbeFrame *pDelFrame;   /* List of frame objects to free on VM reset */
  int nFrame;             /* Number of frames in pFrame list */
  u32 expmask;            /* Binding to these vars invalidates VM */
  SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */

  return sqlite3_value_double(p->apArg[p->nUsed++]);
}
static char *getTextArg(PrintfArguments *p){
  if( p->nArg<=p->nUsed ) return 0;
  return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
}

/*
** Allocate memory for a temporary buffer needed for printf rendering.
**
** If the requested size of the temp buffer is larger than the size
** of the output buffer in pAccum, then cause an SQLITE_TOOBIG error.
** Do the size check before the memory allocation to prevent rogue
** SQL from requesting large allocations using the precision or width
** field of the printf() function.
*/
static char *printfTempBuf(sqlite3_str *pAccum, sqlite3_int64 n){
  char *z;
  if( n>pAccum->nAlloc && n>pAccum->mxAlloc ){
    setStrAccumError(pAccum, SQLITE_TOOBIG);
    return 0;
  }
  z = sqlite3DbMallocRaw(pAccum->db, n);
  if( z==0 ){
    setStrAccumError(pAccum, SQLITE_NOMEM);
  }
  return z;
}

/*
** On machines with a small stack size, you can redefine the
** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
*/
#ifndef SQLITE_PRINT_BUF_SIZE
# define SQLITE_PRINT_BUF_SIZE 70

      sqlite3_str_append(pAccum, "%", 1);
      break;
    }
    /* Find out what flags are present */
    flag_leftjustify = flag_prefix = cThousand =
     flag_alternateform = flag_altform2 = flag_zeropad = 0;
    done = 0;
    width = 0;
    flag_long = 0;
    precision = -1;
    do{
      switch( c ){
        case '-':   flag_leftjustify = 1;     break;
        case '+':   flag_prefix = '+';        break;
        case ' ':   flag_prefix = ' ';        break;
        case '#':   flag_alternateform = 1;   break;
        case '!':   flag_altform2 = 1;        break;
        case '0':   flag_zeropad = 1;         break;
        case ',':   cThousand = ',';          break;
        default:    done = 1;                 break;
        case 'l': {
          flag_long = 1;
          c = *++fmt;
          if( c=='l' ){
            c = *++fmt;
            flag_long = 2;
          }
          done = 1;
          break;
        }
        case '1': case '2': case '3': case '4': case '5':
        case '6': case '7': case '8': case '9': {
          unsigned wx = c - '0';
          while( (c = *++fmt)>='0' && c<='9' ){
            wx = wx*10 + c - '0';
          }
          testcase( wx>0x7fffffff );
          width = wx & 0x7fffffff;
#ifdef SQLITE_PRINTF_PRECISION_LIMIT
          if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
            width = SQLITE_PRINTF_PRECISION_LIMIT;
          }
#endif
          if( c!='.' && c!='l' ){
            done = 1;
          }else{
            fmt--;
          }
          break;
        }
        case '*': {
          if( bArgList ){
            width = (int)getIntArg(pArgList);
          }else{
            width = va_arg(ap,int);
          }
          if( width<0 ){
            flag_leftjustify = 1;
            width = width >= -2147483647 ? -width : 0;
          }
#ifdef SQLITE_PRINTF_PRECISION_LIMIT
          if( width>SQLITE_PRINTF_PRECISION_LIMIT ){
            width = SQLITE_PRINTF_PRECISION_LIMIT;
          }
#endif
          if( (c = fmt[1])!='.' && c!='l' ){
            c = *++fmt;
            done = 1;
          }
          break;
        }
        case '.': {
          c = *++fmt;
          if( c=='*' ){
            if( bArgList ){
              precision = (int)getIntArg(pArgList);
            }else{
              precision = va_arg(ap,int);
            }
            if( precision<0 ){
              precision = precision >= -2147483647 ? -precision : -1;
            }
            c = *++fmt;
          }else{
            unsigned px = 0;
            while( c>='0' && c<='9' ){
              px = px*10 + c - '0';
              c = *++fmt;
            }
            testcase( px>0x7fffffff );
            precision = px & 0x7fffffff;
          }
#ifdef SQLITE_PRINTF_PRECISION_LIMIT
          if( precision>SQLITE_PRINTF_PRECISION_LIMIT ){
            precision = SQLITE_PRINTF_PRECISION_LIMIT;
          }
#endif
          if( c=='l' ){
            --fmt;
          }else{
            done = 1;
          }
          break;
        }
      }
    }while( !done && (c=(*++fmt))!=0 );








































































    /* Fetch the info entry for the field */
    infop = &fmtinfo[0];
    xtype = etINVALID;
    for(idx=0; idx<ArraySize(fmtinfo); idx++){
      if( c==fmtinfo[idx].fmttype ){
        infop = &fmtinfo[idx];
        xtype = infop->type;

        if( flag_zeropad && precision<width-(prefix!=0) ){
          precision = width-(prefix!=0);
        }
        if( precision<etBUFSIZE-10-etBUFSIZE/3 ){
          nOut = etBUFSIZE;
          zOut = buf;
        }else{
          u64 n;
          n = (u64)precision + 10;
          if( cThousand ) n += precision/3;
          zOut = zExtra = printfTempBuf(pAccum, n);
          if( zOut==0 ) return;



          nOut = (int)n;
        }
        bufpt = &zOut[nOut-1];
        if( xtype==etORDINAL ){
          static const char zOrd[] = "thstndrd";
          int x = (int)(longvalue % 10);
          if( x>=4 || (longvalue/10)%10==1 ){

          flag_rtz = flag_altform2;
        }
        if( xtype==etEXP ){
          e2 = 0;
        }else{
          e2 = exp;
        }
        {
          i64 szBufNeeded;           /* Size of a temporary buffer needed */
          szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;
          if( szBufNeeded > etBUFSIZE ){
            bufpt = zExtra = printfTempBuf(pAccum, szBufNeeded);

            if( bufpt==0 ) return;


          }
        }
        zOut = bufpt;
        nsd = 16 + flag_altform2*10;
        flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
        /* The sign in front of the number */
        if( prefix ){

          if( flag_altform2 && (ch&0xc0)==0xc0 ){
            while( (escarg[i+1]&0xc0)==0x80 ){ i++; }
          }
        }
        needQuote = !isnull && xtype==etSQLESCAPE2;
        n += i + 3;
        if( n>etBUFSIZE ){
          bufpt = zExtra = printfTempBuf(pAccum, n);
          if( bufpt==0 ) return;



        }else{
          bufpt = buf;
        }
        j = 0;
        if( needQuote ) bufpt[j++] = q;
        k = i;
        for(i=0; i<k; i++){

    sqlite3_str_appendf(&x, "{%d,*}", pItem->iCursor);
    if( pItem->zDatabase ){
      sqlite3_str_appendf(&x, " %s.%s", pItem->zDatabase, pItem->zName);
    }else if( pItem->zName ){
      sqlite3_str_appendf(&x, " %s", pItem->zName);
    }
    if( pItem->pTab ){
      sqlite3_str_appendf(&x, " tab=%Q nCol=%d ptr=%p",
           pItem->pTab->zName, pItem->pTab->nCol, pItem->pTab);
    }
    if( pItem->zAlias ){
      sqlite3_str_appendf(&x, " (AS %s)", pItem->zAlias);
    }
    if( pItem->fg.jointype & JT_LEFT ){
      sqlite3_str_appendf(&x, " LEFT-JOIN");
    }

** The input string must be zero-terminated.  A new zero-terminator
** is added to the dequoted string.
**
** The return value is -1 if no dequoting occurs or the length of the
** dequoted string, exclusive of the zero terminator, if dequoting does
** occur.
**
** 2002-02-14: This routine is extended to remove MS-Access style
** brackets from around identifiers.  For example:  "[a-b-c]" becomes
** "a-b-c".
*/
SQLITE_PRIVATE void sqlite3Dequote(char *z){
  char quote;
  int i, j;
  if( z==0 ) return;

        break;
      }
    }else{
      z[j++] = z[i];
    }
  }
  z[j] = 0;
}
SQLITE_PRIVATE void sqlite3DequoteExpr(Expr *p){
  assert( sqlite3Isquote(p->u.zToken[0]) );
  p->flags |= p->u.zToken[0]=='"' ? EP_Quoted|EP_DblQuoted : EP_Quoted;
  sqlite3Dequote(p->u.zToken);
}

/*
** Generate a Token object from a string
*/
SQLITE_PRIVATE void sqlite3TokenInit(Token *p, char *z){
  p->z = z;

    ** 0x9e3779b1 is 2654435761 which is the closest prime number to
    ** (2**32)*golden_ratio, where golden_ratio = (sqrt(5) - 1)/2. */
    h += sqlite3UpperToLower[c];
    h *= 0x9e3779b1;
  }
  return h;
}
















/* Link pNew element into the hash table pH.  If pEntry!=0 then also
** insert pNew into the pEntry hash bucket.
*/
static void insertElement(
  Hash *pH,              /* The complete hash table */

    if( sqlite3StrICmp(elem->pKey,pKey)==0 ){ 
      return elem;
    }
    elem = elem->next;
  }
  return &nullElement;
}



































/* Remove a single entry from the hash table given a pointer to that
** element and a hash on the element's key.
*/
static void removeElementGivenHash(
  Hash *pH,         /* The pH containing "elem" */
  HashElem* elem,   /* The element to be removed from the pH */

** found, or NULL if there is no match.
*/
SQLITE_PRIVATE void *sqlite3HashFind(const Hash *pH, const char *pKey){
  assert( pH!=0 );
  assert( pKey!=0 );
  return findElementWithHash(pH, pKey, 0)->data;
}









/* Insert an element into the hash table pH.  The key is pKey
** and the data is "data".
**
** If no element exists with a matching key, then a new
** element is created and NULL is returned.
**

*/
#define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData))

/* An open file */
struct MemFile {
  sqlite3_file base;              /* IO methods */
  sqlite3_int64 sz;               /* Size of the file */
  sqlite3_int64 szAlloc;          /* Space allocated to aData */
  sqlite3_int64 szMax;            /* Maximum allowed size of the file */
  unsigned char *aData;           /* content of the file */
  int nMmap;                      /* Number of memory mapped pages */
  unsigned mFlags;                /* Flags */
  int eLock;                      /* Most recent lock against this file */
};

/*

** Try to enlarge the memory allocation to hold at least sz bytes
*/
static int memdbEnlarge(MemFile *p, sqlite3_int64 newSz){
  unsigned char *pNew;
  if( (p->mFlags & SQLITE_DESERIALIZE_RESIZEABLE)==0 || p->nMmap>0 ){
    return SQLITE_FULL;
  }
  if( newSz>p->szMax ){
    return SQLITE_FULL;
  }
  newSz *= 2;
  if( newSz>p->szMax ) newSz = p->szMax;
  pNew = sqlite3_realloc64(p->aData, newSz);
  if( pNew==0 ) return SQLITE_NOMEM;
  p->aData = pNew;
  p->szAlloc = newSz;
  return SQLITE_OK;
}

/*
** Write data to an memdb-file.
*/
static int memdbWrite(
  sqlite3_file *pFile,
  const void *z,
  int iAmt,
  sqlite_int64 iOfst
){
  MemFile *p = (MemFile *)pFile;
  if( NEVER(p->mFlags & SQLITE_DESERIALIZE_READONLY) ) return SQLITE_READONLY;
  if( iOfst+iAmt>p->sz ){
    int rc;
    if( iOfst+iAmt>p->szAlloc
     && (rc = memdbEnlarge(p, iOfst+iAmt))!=SQLITE_OK
    ){
      return rc;
    }
    if( iOfst>p->sz ) memset(p->aData+p->sz, 0, iOfst-p->sz);
    p->sz = iOfst+iAmt;
  }
  memcpy(p->aData+iOfst, z, iAmt);

}

/*
** Lock an memdb-file.
*/
static int memdbLock(sqlite3_file *pFile, int eLock){
  MemFile *p = (MemFile *)pFile;
  if( eLock>SQLITE_LOCK_SHARED 
   && (p->mFlags & SQLITE_DESERIALIZE_READONLY)!=0
  ){
    return SQLITE_READONLY;
  }
  p->eLock = eLock;
  return SQLITE_OK;
}

#if 0 /* Never used because memdbAccess() always returns false */
/*
** Check if another file-handle holds a RESERVED lock on an memdb-file.

*/
static int memdbFileControl(sqlite3_file *pFile, int op, void *pArg){
  MemFile *p = (MemFile *)pFile;
  int rc = SQLITE_NOTFOUND;
  if( op==SQLITE_FCNTL_VFSNAME ){
    *(char**)pArg = sqlite3_mprintf("memdb(%p,%lld)", p->aData, p->sz);
    rc = SQLITE_OK;
  }
  if( op==SQLITE_FCNTL_SIZE_LIMIT ){
    sqlite3_int64 iLimit = *(sqlite3_int64*)pArg;
    if( iLimit<p->sz ){
      if( iLimit<0 ){
        iLimit = p->szMax;
      }else{
        iLimit = p->sz;
      }
    }
    p->szMax = iLimit;
    *(sqlite3_int64*)pArg = iLimit;
    rc = SQLITE_OK;
  }
  return rc;
}

#if 0  /* Not used because of SQLITE_IOCAP_POWERSAFE_OVERWRITE */
/*
** Return the sector-size in bytes for an memdb-file.

static int memdbFetch(
  sqlite3_file *pFile,
  sqlite3_int64 iOfst,
  int iAmt,
  void **pp
){
  MemFile *p = (MemFile *)pFile;
  if( iOfst+iAmt>p->sz ){
    *pp = 0;
  }else{
    p->nMmap++;
    *pp = (void*)(p->aData + iOfst);
  }
  return SQLITE_OK;
}

/* Release a memory-mapped page */
static int memdbUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
  MemFile *p = (MemFile *)pFile;
  p->nMmap--;

    return ORIGVFS(pVfs)->xOpen(ORIGVFS(pVfs), zName, pFile, flags, pOutFlags);
  }
  memset(p, 0, sizeof(*p));
  p->mFlags = SQLITE_DESERIALIZE_RESIZEABLE | SQLITE_DESERIALIZE_FREEONCLOSE;
  assert( pOutFlags!=0 );  /* True because flags==SQLITE_OPEN_MAIN_DB */
  *pOutFlags = flags | SQLITE_OPEN_MEMORY;
  p->base.pMethods = &memdb_io_methods;
  p->szMax = sqlite3GlobalConfig.mxMemdbSize;
  return SQLITE_OK;
}

#if 0 /* Only used to delete rollback journals, master journals, and WAL
      ** files, none of which exist in memdb.  So this routine is never used */
/*
** Delete the file located at zPath. If the dirSync argument is true,

  }
  p = memdbFromDbSchema(db, zSchema);
  if( p==0 ){
    rc = SQLITE_ERROR;
  }else{
    p->aData = pData;
    p->sz = szDb;
    p->szAlloc = szBuf;
    p->szMax = szBuf;
    if( p->szMax<sqlite3GlobalConfig.mxMemdbSize ){
      p->szMax = sqlite3GlobalConfig.mxMemdbSize;
    }
    p->mFlags = mFlags;
    rc = SQLITE_OK;
  }

end_deserialize:
  sqlite3_finalize(pStmt);
  sqlite3_mutex_leave(db->mutex);

typedef struct PGroup PGroup;

/*
** Each cache entry is represented by an instance of the following 
** structure. Unless SQLITE_PCACHE_SEPARATE_HEADER is defined, a buffer of
** PgHdr1.pCache->szPage bytes is allocated directly before this structure 
** in memory.
**
** Note: Variables isBulkLocal and isAnchor were once type "u8". That works,
** but causes a 2-byte gap in the structure for most architectures (since 
** pointers must be either 4 or 8-byte aligned). As this structure is located
** in memory directly after the associated page data, if the database is
** corrupt, code at the b-tree layer may overread the page buffer and 
** read part of this structure before the corruption is detected. This
** can cause a valgrind error if the unitialized gap is accessed. Using u16
** ensures there is no such gap, and therefore no bytes of unitialized memory
** in the structure.
*/
struct PgHdr1 {
  sqlite3_pcache_page page;      /* Base class. Must be first. pBuf & pExtra */
  unsigned int iKey;             /* Key value (page number) */
  u16 isBulkLocal;               /* This page from bulk local storage */
  u16 isAnchor;                  /* This is the PGroup.lru element */
  PgHdr1 *pNext;                 /* Next in hash table chain */
  PCache1 *pCache;               /* Cache that currently owns this page */
  PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
  PgHdr1 *pLruPrev;              /* Previous in LRU list of unpinned pages */
                                 /* NB: pLruPrev is only valid if pLruNext!=0 */
};

/*
** A page is pinned if it is not on the LRU list.  To be "pinned" means
** that the page is in active use and must not be deallocated.
*/
#define PAGE_IS_PINNED(p)    ((p)->pLruNext==0)

  int szExtra;                        /* sizeof(MemPage)+sizeof(PgHdr) */
  int szAlloc;                        /* Total size of one pcache line */
  int bPurgeable;                     /* True if cache is purgeable */
  unsigned int nMin;                  /* Minimum number of pages reserved */
  unsigned int nMax;                  /* Configured "cache_size" value */
  unsigned int n90pct;                /* nMax*9/10 */
  unsigned int iMaxKey;               /* Largest key seen since xTruncate() */
  unsigned int nPurgeableDummy;       /* pnPurgeable points here when not used*/

  /* Hash table of all pages. The following variables may only be accessed
  ** when the accessor is holding the PGroup mutex.
  */
  unsigned int nRecyclable;           /* Number of pages in the LRU list */
  unsigned int nPage;                 /* Total number of pages in apHash */
  unsigned int nHash;                 /* Number of slots in apHash[] */

    do{
      PgHdr1 *pX = (PgHdr1*)&zBulk[pCache->szPage];
      pX->page.pBuf = zBulk;
      pX->page.pExtra = &pX[1];
      pX->isBulkLocal = 1;
      pX->isAnchor = 0;
      pX->pNext = pCache->pFree;
      pX->pLruPrev = 0;           /* Initializing this saves a valgrind error */
      pCache->pFree = pX;
      zBulk += pCache->szAlloc;
    }while( --nBulk );
  }
  return pCache->pFree!=0;
}

/*
** Malloc function used by SQLite to obtain space from the buffer configured
** using sqlite3_config(SQLITE_CONFIG_PAGECACHE) option. If no such buffer
** exists, this function falls back to sqlite3Malloc().
*/
SQLITE_PRIVATE void *sqlite3PageMalloc(int sz){
  /* During rebalance operations on a corrupt database file, it is sometimes
  ** (rarely) possible to overread the temporary page buffer by a few bytes.
  ** Enlarge the allocation slightly so that this does not cause problems. */
  return pcache1Alloc(sz);
}

/*
** Free an allocated buffer obtained from sqlite3PageMalloc().
*/
SQLITE_PRIVATE void sqlite3PageFree(void *p){

  assert( PAGE_IS_UNPINNED(pPage) );
  assert( pPage->pLruNext );
  assert( pPage->pLruPrev );
  assert( sqlite3_mutex_held(pPage->pCache->pGroup->mutex) );
  pPage->pLruPrev->pLruNext = pPage->pLruNext;
  pPage->pLruNext->pLruPrev = pPage->pLruPrev;
  pPage->pLruNext = 0;
  /* pPage->pLruPrev = 0;
  ** No need to clear pLruPrev as it is never accessed if pLruNext is 0 */
  assert( pPage->isAnchor==0 );
  assert( pPage->pCache->pGroup->lru.isAnchor==1 );
  pPage->pCache->nRecyclable--;
  return pPage;
}

    pcache1ResizeHash(pCache);
    if( bPurgeable ){
      pCache->nMin = 10;
      pGroup->nMinPage += pCache->nMin;
      pGroup->mxPinned = pGroup->nMaxPage + 10 - pGroup->nMinPage;
      pCache->pnPurgeable = &pGroup->nPurgeable;
    }else{

      pCache->pnPurgeable = &pCache->nPurgeableDummy;
    }
    pcache1LeaveMutex(pGroup);
    if( pCache->nHash==0 ){
      pcache1Destroy((sqlite3_pcache*)pCache);
      pCache = 0;
    }
  }

  if( pPage ){
    unsigned int h = iKey % pCache->nHash;
    pCache->nPage++;
    pPage->iKey = iKey;
    pPage->pNext = pCache->apHash[h];
    pPage->pCache = pCache;
    pPage->pLruNext = 0;
    /* pPage->pLruPrev = 0;
    ** No need to clear pLruPrev since it is not accessed when pLruNext==0 */
    *(void **)pPage->page.pExtra = 0;
    pCache->apHash[h] = pPage;
    if( iKey>pCache->iMaxKey ){
      pCache->iMaxKey = iKey;
    }
  }
  return pPage;

 
  assert( pPage->pCache==pCache );
  pcache1EnterMutex(pGroup);

  /* It is an error to call this function if the page is already 
  ** part of the PGroup LRU list.
  */
  assert( pPage->pLruNext==0 );
  assert( PAGE_IS_PINNED(pPage) );

  if( reuseUnlikely || pGroup->nPurgeable>pGroup->nMaxPage ){
    pcache1RemoveFromHash(pPage, 1);
  }else{
    /* Add the page to the PGroup LRU list. */
    PgHdr1 **ppFirst = &pGroup->lru.pLruNext;

** Regardless of mxPage, return the current maximum page count.
*/
SQLITE_PRIVATE int sqlite3PagerMaxPageCount(Pager *pPager, int mxPage){
  if( mxPage>0 ){
    pPager->mxPgno = mxPage;
  }
  assert( pPager->eState!=PAGER_OPEN );      /* Called only by OP_MaxPgcnt */
  /* assert( pPager->mxPgno>=pPager->dbSize ); */
  /* OP_MaxPgcnt ensures that the parameter passed to this function is not
  ** less than the total number of valid pages in the database. But this
  ** may be less than Pager.dbSize, and so the assert() above is not valid */
  return pPager->mxPgno;
}

/*
** The following set of routines are used to disable the simulated
** I/O error mechanism.  These routines are used to avoid simulated
** errors in places where we do not care about errors.

** but cursors cannot be shared.  Each cursor is associated with a
** particular database connection identified BtCursor.pBtree.db.
**
** Fields in this structure are accessed under the BtShared.mutex
** found at self->pBt->mutex. 
**
** skipNext meaning:
** The meaning of skipNext depends on the value of eState:
**
**   eState            Meaning of skipNext
**   VALID             skipNext is meaningless and is ignored
**   INVALID           skipNext is meaningless and is ignored
**   SKIPNEXT          sqlite3BtreeNext() is a no-op if skipNext>0 and
**                     sqlite3BtreePrevious() is no-op if skipNext<0.
**   REQUIRESEEK       restoreCursorPosition() restores the cursor to
**                     eState=SKIPNEXT if skipNext!=0
**   FAULT             skipNext holds the cursor fault error code.
*/
struct BtCursor {
  u8 eState;                /* One of the CURSOR_XXX constants (see below) */
  u8 curFlags;              /* zero or more BTCF_* flags defined below */
  u8 curPagerFlags;         /* Flags to send to sqlite3PagerGet() */
  u8 hints;                 /* As configured by CursorSetHints() */
  int skipNext;    /* Prev() is noop if negative. Next() is noop if positive.

  assert( 0==pCur->pKey );
  assert( cursorHoldsMutex(pCur) );

  if( pCur->curIntKey ){
    /* Only the rowid is required for a table btree */
    pCur->nKey = sqlite3BtreeIntegerKey(pCur);
  }else{
    /* For an index btree, save the complete key content. It is possible
    ** that the current key is corrupt. In that case, it is possible that
    ** the sqlite3VdbeRecordUnpack() function may overread the buffer by
    ** up to the size of 1 varint plus 1 8-byte value when the cursor 
    ** position is restored. Hence the 17 bytes of padding allocated 
    ** below. */
    void *pKey;
    pCur->nKey = sqlite3BtreePayloadSize(pCur);
    pKey = sqlite3Malloc( pCur->nKey + 9 + 8 );
    if( pKey ){
      rc = sqlite3BtreePayload(pCur, 0, (int)pCur->nKey, pKey);
      if( rc==SQLITE_OK ){
        memset(((u8*)pKey)+pCur->nKey, 0, 9+8);
        pCur->pKey = pKey;
      }else{
        sqlite3_free(pKey);
      }
    }else{
      rc = SQLITE_NOMEM_BKPT;
    }

  int bias,           /* Bias search to the high end */
  int *pRes           /* Write search results here */
){
  int rc;                    /* Status code */
  UnpackedRecord *pIdxKey;   /* Unpacked index key */

  if( pKey ){
    KeyInfo *pKeyInfo = pCur->pKeyInfo;
    assert( nKey==(i64)(int)nKey );
    pIdxKey = sqlite3VdbeAllocUnpackedRecord(pKeyInfo);
    if( pIdxKey==0 ) return SQLITE_NOMEM_BKPT;
    sqlite3VdbeRecordUnpack(pKeyInfo, (int)nKey, pKey, pIdxKey);
    if( pIdxKey->nField==0 || pIdxKey->nField>pKeyInfo->nAllField ){
      rc = SQLITE_CORRUPT_BKPT;
      goto moveto_done;
    }
  }else{
    pIdxKey = 0;
  }
  rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias, pRes);

  }
  pCur->eState = CURSOR_INVALID;
  rc = btreeMoveto(pCur, pCur->pKey, pCur->nKey, 0, &skipNext);
  if( rc==SQLITE_OK ){
    sqlite3_free(pCur->pKey);
    pCur->pKey = 0;
    assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
    if( skipNext ) pCur->skipNext = skipNext;
    if( pCur->skipNext && pCur->eState==CURSOR_VALID ){
      pCur->eState = CURSOR_SKIPNEXT;
    }
  }
  return rc;
}

  if( rc ){
    *pDifferentRow = 1;
    return rc;
  }
  if( pCur->eState!=CURSOR_VALID ){
    *pDifferentRow = 1;
  }else{

    *pDifferentRow = 0;
  }
  return SQLITE_OK;
}

#ifdef SQLITE_ENABLE_CURSOR_HINTS
/*

    return;
  }
  iPtrmap = PTRMAP_PAGENO(pBt, key);
  rc = sqlite3PagerGet(pBt->pPager, iPtrmap, &pDbPage, 0);
  if( rc!=SQLITE_OK ){
    *pRC = rc;
    return;
  }
  if( ((char*)sqlite3PagerGetExtra(pDbPage))[0]!=0 ){
    /* The first byte of the extra data is the MemPage.isInit byte.
    ** If that byte is set, it means this page is also being used
    ** as a btree page. */
    *pRC = SQLITE_CORRUPT_BKPT;
    goto ptrmap_exit;
  }
  offset = PTRMAP_PTROFFSET(iPtrmap, key);
  if( offset<0 ){
    *pRC = SQLITE_CORRUPT_BKPT;
    goto ptrmap_exit;
  }
  assert( offset <= (int)pBt->usableSize-5 );

  if( *pEType<1 || *pEType>5 ) return SQLITE_CORRUPT_PGNO(iPtrmap);
  return SQLITE_OK;
}

#else /* if defined SQLITE_OMIT_AUTOVACUUM */
  #define ptrmapPut(w,x,y,z,rc)
  #define ptrmapGet(w,x,y,z) SQLITE_OK
  #define ptrmapPutOvflPtr(x, y, z, rc)
#endif

/*
** Given a btree page and a cell index (0 means the first cell on
** the page, 1 means the second cell, and so forth) return a pointer
** to the cell content.
**

static u16 cellSize(MemPage *pPage, int iCell){
  return pPage->xCellSize(pPage, findCell(pPage, iCell));
}
#endif

#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** The cell pCell is currently part of page pSrc but will ultimately be part
** of pPage.  (pSrc and pPager are often the same.)  If pCell contains a
** pointer to an overflow page, insert an entry into the pointer-map for
** the overflow page that will be valid after pCell has been moved to pPage.
*/
static void ptrmapPutOvflPtr(MemPage *pPage, MemPage *pSrc, u8 *pCell,int *pRC){
  CellInfo info;
  if( *pRC ) return;
  assert( pCell!=0 );
  pPage->xParseCell(pPage, pCell, &info);
  if( info.nLocal<info.nPayload ){
    Pgno ovfl;
    if( SQLITE_WITHIN(pSrc->aDataEnd, pCell, pCell+info.nLocal) ){
      testcase( pSrc!=pPage );
      *pRC = SQLITE_CORRUPT_BKPT;
      return;
    }
    ovfl = get4byte(&pCell[info.nSize-4]);
    ptrmapPut(pPage->pBt, ovfl, PTRMAP_OVERFLOW1, pPage->pgno, pRC);
  }
}
#endif


/*

  /* This block handles pages with two or fewer free blocks and nMaxFrag
  ** or fewer fragmented bytes. In this case it is faster to move the
  ** two (or one) blocks of cells using memmove() and add the required
  ** offsets to each pointer in the cell-pointer array than it is to 
  ** reconstruct the entire page.  */
  if( (int)data[hdr+7]<=nMaxFrag ){
    int iFree = get2byte(&data[hdr+1]);





    /* If the initial freeblock offset were out of bounds, that would
    ** have been detected by btreeInitPage() when it was computing the
    ** number of free bytes on the page. */



    assert( iFree<=usableSize-4 );
    if( iFree ){
      int iFree2 = get2byte(&data[iFree]);
      if( iFree2>usableSize-4 ) return SQLITE_CORRUPT_PAGE(pPage);
      if( 0==iFree2 || (data[iFree2]==0 && data[iFree2+1]==0) ){
        u8 *pEnd = &data[cellOffset + nCell*2];
        u8 *pAddr;
        int sz2 = 0;
        int sz = get2byte(&data[iFree+2]);
        int top = get2byte(&data[hdr+5]);
        if( top>=iFree ){
          return SQLITE_CORRUPT_PAGE(pPage);
        }
        if( iFree2 ){
          if( iFree+sz>iFree2 ) return SQLITE_CORRUPT_PAGE(pPage);
          sz2 = get2byte(&data[iFree2+2]);
          if( iFree2+sz2 > usableSize ) return SQLITE_CORRUPT_PAGE(pPage);
          memmove(&data[iFree+sz+sz2], &data[iFree+sz], iFree2-(iFree+sz));
          sz += sz2;
        }
        cbrk = top+sz;
        assert( cbrk+(iFree-top) <= usableSize );
        memmove(&data[cbrk], &data[top], iFree-top);
        for(pAddr=&data[cellOffset]; pAddr<pEnd; pAddr+=2){

** well-formed database file, then SQLITE_CORRUPT is returned.
** SQLITE_BUSY is returned if the database is locked.  SQLITE_NOMEM
** is returned if we run out of memory. 
*/
static int lockBtree(BtShared *pBt){
  int rc;              /* Result code from subfunctions */
  MemPage *pPage1;     /* Page 1 of the database file */
  u32 nPage;           /* Number of pages in the database */
  u32 nPageFile = 0;   /* Number of pages in the database file */
  u32 nPageHeader;     /* Number of pages in the database according to hdr */

  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( pBt->pPage1==0 );
  rc = sqlite3PagerSharedLock(pBt->pPager);
  if( rc!=SQLITE_OK ) return rc;
  rc = btreeGetPage(pBt, 1, &pPage1, 0);
  if( rc!=SQLITE_OK ) return rc;

  /* Do some checking to help insure the file we opened really is
  ** a valid database file. 
  */
  nPage = nPageHeader = get4byte(28+(u8*)pPage1->aData);
  sqlite3PagerPagecount(pBt->pPager, (int*)&nPageFile);
  if( nPage==0 || memcmp(24+(u8*)pPage1->aData, 92+(u8*)pPage1->aData,4)!=0 ){
    nPage = nPageFile;
  }
  if( (pBt->db->flags & SQLITE_ResetDatabase)!=0 ){
    nPage = 0;
  }
  if( nPage>0 ){

    ** between 512 and 65536 inclusive. */
    if( ((pageSize-1)&pageSize)!=0
     || pageSize>SQLITE_MAX_PAGE_SIZE 
     || pageSize<=256 
    ){
      goto page1_init_failed;
    }
    pBt->btsFlags |= BTS_PAGESIZE_FIXED;
    assert( (pageSize & 7)==0 );
    /* EVIDENCE-OF: R-59310-51205 The "reserved space" size in the 1-byte
    ** integer at offset 20 is the number of bytes of space at the end of
    ** each page to reserve for extensions. 
    **
    ** EVIDENCE-OF: R-37497-42412 The size of the reserved region is
    ** determined by the one-byte unsigned integer found at an offset of 20

  rc = pPage->isInit ? SQLITE_OK : btreeInitPage(pPage);
  if( rc!=SQLITE_OK ) return rc;
  nCell = pPage->nCell;

  for(i=0; i<nCell; i++){
    u8 *pCell = findCell(pPage, i);

    ptrmapPutOvflPtr(pPage, pPage, pCell, &rc);

    if( !pPage->leaf ){
      Pgno childPgno = get4byte(pCell);
      ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno, &rc);
    }
  }

      }while( ALWAYS(pPrev) );
    }
    btreeReleaseAllCursorPages(pCur);
    unlockBtreeIfUnused(pBt);
    sqlite3_free(pCur->aOverflow);
    sqlite3_free(pCur->pKey);
    sqlite3BtreeLeave(pBtree);
    pCur->pBtree = 0;
  }
  return SQLITE_OK;
}

/*
** Make sure the BtCursor* given in the argument has a valid
** BtCursor.info structure.  If it is not already valid, call

*/
SQLITE_PRIVATE u32 sqlite3BtreePayloadSize(BtCursor *pCur){
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  getCellInfo(pCur);
  return pCur->info.nPayload;
}

/*
** Return an upper bound on the size of any record for the table
** that the cursor is pointing into.
**
** This is an optimization.  Everything will still work if this
** routine always returns 2147483647 (which is the largest record
** that SQLite can handle) or more.  But returning a smaller value might
** prevent large memory allocations when trying to interpret a
** corrupt datrabase.
**
** The current implementation merely returns the size of the underlying
** database file.
*/
SQLITE_PRIVATE sqlite3_int64 sqlite3BtreeMaxRecordSize(BtCursor *pCur){
  assert( cursorHoldsMutex(pCur) );
  assert( pCur->eState==CURSOR_VALID );
  return pCur->pBt->pageSize * (sqlite3_int64)pCur->pBt->nPage;
}

/*
** Given the page number of an overflow page in the database (parameter
** ovfl), this function finds the page number of the next page in the 
** linked list of overflow pages. If possible, it uses the auto-vacuum
** pointer-map data instead of reading the content of page ovfl to do so. 
**

        *pRes = -1;
        return SQLITE_OK;
      }
      /* If the requested key is one more than the previous key, then
      ** try to get there using sqlite3BtreeNext() rather than a full
      ** binary search.  This is an optimization only.  The correct answer
      ** is still obtained without this case, only a little more slowely */
      if( pCur->info.nKey+1==intKey ){
        *pRes = 0;
        rc = sqlite3BtreeNext(pCur, 0);
        if( rc==SQLITE_OK ){
          getCellInfo(pCur);
          if( pCur->info.nKey==intKey ){
            return SQLITE_OK;
          }

          u8 * const pCellBody = pCell - pPage->childPtrSize;
          pPage->xParseCell(pPage, pCellBody, &pCur->info);
          nCell = (int)pCur->info.nKey;
          testcase( nCell<0 );   /* True if key size is 2^32 or more */
          testcase( nCell==0 );  /* Invalid key size:  0x80 0x80 0x00 */
          testcase( nCell==1 );  /* Invalid key size:  0x80 0x80 0x01 */
          testcase( nCell==2 );  /* Minimum legal index key size */
          if( nCell<2 || nCell/pCur->pBt->usableSize>pCur->pBt->nPage ){
            rc = SQLITE_CORRUPT_PAGE(pPage);
            goto moveto_finish;
          }
          pCellKey = sqlite3Malloc( nCell+18 );
          if( pCellKey==0 ){
            rc = SQLITE_NOMEM_BKPT;
            goto moveto_finish;

*/
static SQLITE_NOINLINE int btreeNext(BtCursor *pCur){
  int rc;
  int idx;
  MemPage *pPage;

  assert( cursorOwnsBtShared(pCur) );

  if( pCur->eState!=CURSOR_VALID ){
    assert( (pCur->curFlags & BTCF_ValidOvfl)==0 );
    rc = restoreCursorPosition(pCur);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    if( CURSOR_INVALID==pCur->eState ){
      return SQLITE_DONE;
    }

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




    }
  }

  pPage = pCur->pPage;
  idx = ++pCur->ix;
  if( !pPage->isInit ){
    /* The only known way for this to happen is for there to be a

  }
}
SQLITE_PRIVATE int sqlite3BtreeNext(BtCursor *pCur, int flags){
  MemPage *pPage;
  UNUSED_PARAMETER( flags );  /* Used in COMDB2 but not native SQLite */
  assert( cursorOwnsBtShared(pCur) );
  assert( flags==0 || flags==1 );

  pCur->info.nSize = 0;
  pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
  if( pCur->eState!=CURSOR_VALID ) return btreeNext(pCur);
  pPage = pCur->pPage;
  if( (++pCur->ix)>=pPage->nCell ){
    pCur->ix--;
    return btreeNext(pCur);

** use this hint, but COMDB2 does.
*/
static SQLITE_NOINLINE int btreePrevious(BtCursor *pCur){
  int rc;
  MemPage *pPage;

  assert( cursorOwnsBtShared(pCur) );

  assert( (pCur->curFlags & (BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey))==0 );
  assert( pCur->info.nSize==0 );
  if( pCur->eState!=CURSOR_VALID ){
    rc = restoreCursorPosition(pCur);
    if( rc!=SQLITE_OK ){
      return rc;
    }
    if( CURSOR_INVALID==pCur->eState ){
      return SQLITE_DONE;
    }

    if( CURSOR_SKIPNEXT==pCur->eState ){
      pCur->eState = CURSOR_VALID;
      if( pCur->skipNext<0 ) return SQLITE_OK;




    }
  }

  pPage = pCur->pPage;
  assert( pPage->isInit );
  if( !pPage->leaf ){
    int idx = pCur->ix;

    }
  }
  return rc;
}
SQLITE_PRIVATE int sqlite3BtreePrevious(BtCursor *pCur, int flags){
  assert( cursorOwnsBtShared(pCur) );
  assert( flags==0 || flags==1 );

  UNUSED_PARAMETER( flags );  /* Used in COMDB2 but not native SQLite */
  pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidOvfl|BTCF_ValidNKey);
  pCur->info.nSize = 0;
  if( pCur->eState!=CURSOR_VALID
   || pCur->ix==0
   || pCur->pPage->leaf==0
  ){

    if( rc!=SQLITE_OK ){
      releasePage(*ppPage);
      *ppPage = 0;
    }
    TRACE(("ALLOCATE: %d from end of file\n", *pPgno));
  }

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

end_allocate_page:
  releasePage(pTrunk);
  releasePage(pPrevTrunk);
  assert( rc!=SQLITE_OK || sqlite3PagerPageRefcount((*ppPage)->pDbPage)<=1 );
  assert( rc!=SQLITE_OK || (*ppPage)->isInit==0 );
  return rc;

    if( rc ){ *pRC = rc; return; }
    /* 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);

    if( iChild ){
      /* 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);
    }else{
      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 );
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pPage->pBt->autoVacuum ){
      /* 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, pRC);
    }
#endif
  }
}

/*
** The following parameters determine how many adjacent pages get involved
** in a balancing operation.  NN is the number of neighbors on either side
** of the page that participate in the balancing operation.  NB is the
** total number of pages that participate, including the target page and
** NN neighbors on either side.
**
** The minimum value of NN is 1 (of course).  Increasing NN above 1
** (to 2 or 3) gives a modest improvement in SELECT and DELETE performance
** in exchange for a larger degradation in INSERT and UPDATE performance.
** The value of NN appears to give the best results overall.
**
** (Later:) The description above makes it seem as if these values are
** tunable - as if you could change them and recompile and it would all work.
** But that is unlikely.  NB has been 3 since the inception of SQLite and
** we have never tested any other value.
*/
#define NN 1             /* Number of neighbors on either side of pPage */
#define NB 3             /* (NN*2+1): Total pages involved in the balance */

/*
** A CellArray object contains a cache of pointers and sizes for a
** consecutive sequence of cells that might be held on multiple pages.
**
** The cells in this array are the divider cell or cells from the pParent
** page plus up to three child pages.  There are a total of nCell cells.
**
** pRef is a pointer to one of the pages that contributes cells.  This is
** used to access information such as MemPage.intKey and MemPage.pBt->pageSize
** which should be common to all pages that contribute cells to this array.
**
** apCell[] and szCell[] hold, respectively, pointers to the start of each
** cell and the size of each cell.  Some of the apCell[] pointers might refer
** to overflow cells.  In other words, some apCel[] pointers might not point
** to content area of the pages.
**
** A szCell[] of zero means the size of that cell has not yet been computed.
**
** The cells come from as many as four different pages:
**
**             -----------
**             | Parent  |
**             -----------
**            /     |     \
**           /      |      \
**  ---------   ---------   ---------
**  |Child-1|   |Child-2|   |Child-3|
**  ---------   ---------   ---------
**
** The order of cells is in the array is for an index btree is:
**
**       1.  All cells from Child-1 in order
**       2.  The first divider cell from Parent
**       3.  All cells from Child-2 in order
**       4.  The second divider cell from Parent
**       5.  All cells from Child-3 in order
**
** For a table-btree (with rowids) the items 2 and 4 are empty because
** content exists only in leaves and there are no divider cells.
**
** For an index btree, the apEnd[] array holds pointer to the end of page
** for Child-1, the Parent, Child-2, the Parent (again), and Child-3,
** respectively. The ixNx[] array holds the number of cells contained in
** each of these 5 stages, and all stages to the left.  Hence:
**
**    ixNx[0] = Number of cells in Child-1.
**    ixNx[1] = Number of cells in Child-1 plus 1 for first divider.
**    ixNx[2] = Number of cells in Child-1 and Child-2 + 1 for 1st divider.
**    ixNx[3] = Number of cells in Child-1 and Child-2 + both divider cells
**    ixNx[4] = Total number of cells.
**
** For a table-btree, the concept is similar, except only apEnd[0]..apEnd[2]
** are used and they point to the leaf pages only, and the ixNx value are:
**
**    ixNx[0] = Number of cells in Child-1.
**    ixNx[1] = Number of cells in Child-1 and Child-2 + 1 for 1st divider.
**    ixNx[2] = Number of cells in Child-1 and Child-2 + both divider cells
*/
typedef struct CellArray CellArray;
struct CellArray {
  int nCell;              /* Number of cells in apCell[] */
  MemPage *pRef;          /* Reference page */
  u8 **apCell;            /* All cells begin balanced */
  u16 *szCell;            /* Local size of all cells in apCell[] */
  u8 *apEnd[NB*2];        /* MemPage.aDataEnd values */
  int ixNx[NB*2];         /* Index of at which we move to the next apEnd[] */
};

/*
** Make sure the cell sizes at idx, idx+1, ..., idx+N-1 have been
** computed.
*/
static void populateCellCache(CellArray *p, int idx, int N){

** function works around problems caused by this by making a copy of any 
** such cells before overwriting the page data.
**
** The MemPage.nFree field is invalidated by this function. It is the 
** responsibility of the caller to set it correctly.
*/
static int rebuildPage(
  CellArray *pCArray,             /* Content to be added to page pPg */
  int iFirst,                     /* First cell in pCArray to use */
  int nCell,                      /* Final number of cells on page */

  MemPage *pPg                    /* The page to be reconstructed */
){
  const int hdr = pPg->hdrOffset;          /* Offset of header on pPg */
  u8 * const aData = pPg->aData;           /* Pointer to data for pPg */
  const int usableSize = pPg->pBt->usableSize;
  u8 * const pEnd = &aData[usableSize];
  int i = iFirst;                 /* Which cell to copy from pCArray*/
  u32 j;                          /* Start of cell content area */
  int iEnd = i+nCell;             /* Loop terminator */
  u8 *pCellptr = pPg->aCellIdx;
  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*/ ){
    u8 *pCell = pCArray->apCell[i];
    u16 sz = pCArray->szCell[i];
    assert( sz>0 );
    if( SQLITE_WITHIN(pCell,aData,pEnd) ){
      if( ((uptr)(pCell+sz))>(uptr)pEnd ) return SQLITE_CORRUPT_BKPT;
      pCell = &pTmp[pCell - aData];
    }else if( (uptr)(pCell+sz)>(uptr)pSrcEnd
           && (uptr)(pCell)<(uptr)pSrcEnd
    ){
      return SQLITE_CORRUPT_BKPT;
    }

    pData -= sz;
    put2byte(pCellptr, (pData - aData));
    pCellptr += 2;
    if( pData < pCellptr ) return SQLITE_CORRUPT_BKPT;
    memcpy(pData, pCell, sz);
    assert( sz==pPg->xCellSize(pPg, pCell) || CORRUPT_DB );
    testcase( sz!=pPg->xCellSize(pPg,pCell) );
    i++;
    if( i>=iEnd ) break;
    if( pCArray->ixNx[k]<=i ){
      k++;
      pSrcEnd = pCArray->apEnd[k];
    }
  }

  /* The pPg->nFree field is now set incorrectly. The caller will fix it. */
  pPg->nCell = nCell;
  pPg->nOverflow = 0;

  put2byte(&aData[hdr+1], 0);
  put2byte(&aData[hdr+3], pPg->nCell);
  put2byte(&aData[hdr+5], pData - aData);
  aData[hdr+7] = 0x00;
  return SQLITE_OK;
}

/*
** The pCArray objects contains pointers to b-tree cells and the cell sizes.

** This function attempts to add the cells stored in the array to page pPg.
** If it cannot (because the page needs to be defragmented before the cells
** will fit), non-zero is returned. Otherwise, if the cells are added
** successfully, zero is returned.
**
** Argument pCellptr points to the first entry in the cell-pointer array
** (part of page pPg) to populate. After cell apCell[0] is written to the
** page body, a 16-bit offset is written to pCellptr. And so on, for each
** cell in the array. It is the responsibility of the caller to ensure
** that it is safe to overwrite this part of the cell-pointer array.
**

** all cells - not just those inserted by the current call). If the content
** area must be extended to before this point in order to accomodate all
** cells in apCell[], then the cells do not fit and non-zero is returned.
*/
static int pageInsertArray(
  MemPage *pPg,                   /* Page to add cells to */
  u8 *pBegin,                     /* End of cell-pointer array */
  u8 **ppData,                    /* IN/OUT: Page content-area pointer */
  u8 *pCellptr,                   /* Pointer to cell-pointer area */
  int iFirst,                     /* Index of first cell to add */
  int nCell,                      /* Number of cells to add to pPg */
  CellArray *pCArray              /* Array of cells */
){
  int i = iFirst;                 /* Loop counter - cell index to insert */
  u8 *aData = pPg->aData;         /* Complete page */
  u8 *pData = *ppData;            /* Content area.  A subset of aData[] */
  int iEnd = iFirst + nCell;      /* End of loop. One past last cell to ins */
  int k;                          /* Current slot in pCArray->apEnd[] */
  u8 *pEnd;                       /* Maximum extent of cell data */
  assert( CORRUPT_DB || pPg->hdrOffset==0 );    /* Never called on page 1 */
  if( iEnd<=iFirst ) return 0;
  for(k=0; pCArray->ixNx[k]<=i && ALWAYS(k<NB*2); k++){}
  pEnd = pCArray->apEnd[k];
  while( 1 /*Exit by break*/ ){
    int sz, rc;
    u8 *pSlot;
    sz = cachedCellSize(pCArray, i);
    if( (aData[1]==0 && aData[2]==0) || (pSlot = pageFindSlot(pPg,sz,&rc))==0 ){
      if( (pData - pBegin)<sz ) return 1;
      pData -= sz;
      pSlot = pData;
    }
    /* pSlot and pCArray->apCell[i] will never overlap on a well-formed
    ** database.  But they might for a corrupt database.  Hence use memmove()
    ** since memcpy() sends SIGABORT with overlapping buffers on OpenBSD */
    assert( (pSlot+sz)<=pCArray->apCell[i]
         || pSlot>=(pCArray->apCell[i]+sz)
         || CORRUPT_DB );
    if( (uptr)(pCArray->apCell[i]+sz)>(uptr)pEnd
     && (uptr)(pCArray->apCell[i])<(uptr)pEnd
    ){
      assert( CORRUPT_DB );
      (void)SQLITE_CORRUPT_BKPT;
      return 1;
    }
    memmove(pSlot, pCArray->apCell[i], sz);
    put2byte(pCellptr, (pSlot - aData));
    pCellptr += 2;
    i++;
    if( i>=iEnd ) break;
    if( pCArray->ixNx[k]<=i ){
      k++;
      pEnd = pCArray->apEnd[k];
    }
  }
  *ppData = pData;
  return 0;
}

/*
** The pCArray object contains pointers to b-tree cells and their sizes.
**
** This function adds the space associated with each cell in the array
** that is currently stored within the body of pPg to the pPg free-list.
** The cell-pointers and other fields of the page are not updated.
**
** This function returns the total number of cells added to the free-list.
*/
static int pageFreeArray(
  MemPage *pPg,                   /* Page to edit */
  int iFirst,                     /* First cell to delete */
  int nCell,                      /* Cells to delete */

    assert( pFree>aData && (pFree - aData)<65536 );
    freeSpace(pPg, (u16)(pFree - aData), szFree);
  }
  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
** pCArray->apCell[iOld].  After balancing, this page should hold nNew cells
** starting at apCell[iNew].
**
** This routine makes the necessary adjustments to pPg so that it contains
** the correct cells after being balanced.
**
** The pPg->nFree field is invalid when this function returns. It is the
** responsibility of the caller to set it correctly.

#ifdef SQLITE_DEBUG
  u8 *pTmp = sqlite3PagerTempSpace(pPg->pBt->pPager);
  memcpy(pTmp, aData, pPg->pBt->usableSize);
#endif

  /* Remove cells from the start and end of the page */
  assert( nCell>=0 );
  if( iOld<iNew ){
    int nShift = pageFreeArray(pPg, iOld, iNew-iOld, pCArray);
    if( nShift>nCell ) return SQLITE_CORRUPT_BKPT;
    memmove(pPg->aCellIdx, &pPg->aCellIdx[nShift*2], nCell*2);
    nCell -= nShift;
  }
  if( iNewEnd < iOldEnd ){
    int nTail = pageFreeArray(pPg, iNewEnd, iOldEnd - iNewEnd, pCArray);
    assert( nCell>=nTail );
    nCell -= nTail;
  }

  pData = &aData[get2byteNotZero(&aData[hdr+5])];
  if( pData<pBegin ) 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;
    memmove(&pCellptr[nAdd*2], pCellptr, nCell*2);
    if( pageInsertArray(
          pPg, pBegin, &pData, pCellptr,
          iNew, nAdd, pCArray
    ) ) goto editpage_fail;
    nCell += nAdd;
  }

  /* Add any overflow cells */
  for(i=0; i<pPg->nOverflow; i++){
    int iCell = (iOld + pPg->aiOvfl[i]) - iNew;
    if( iCell>=0 && iCell<nNew ){
      pCellptr = &pPg->aCellIdx[iCell * 2];
      assert( nCell>=iCell );
      memmove(&pCellptr[2], pCellptr, (nCell - iCell) * 2);
      nCell++;
      if( pageInsertArray(
            pPg, pBegin, &pData, pCellptr,
            iCell+iNew, 1, pCArray
      ) ) goto editpage_fail;
    }
  }

  /* Append cells to the end of the page */
  assert( nCell>=0 );
  pCellptr = &pPg->aCellIdx[nCell*2];
  if( pageInsertArray(
        pPg, pBegin, &pData, pCellptr,
        iNew+nCell, nNew-nCell, pCArray
  ) ) goto editpage_fail;

  pPg->nCell = nNew;

  }
#endif

  return SQLITE_OK;
 editpage_fail:
  /* Unable to edit this page. Rebuild it from scratch instead. */
  populateCellCache(pCArray, iNew, nNew);
  return rebuildPage(pCArray, iNew, nNew, pPg);
}

















#ifndef SQLITE_OMIT_QUICKBALANCE
/*
** This version of balance() handles the common special case where
** a new entry is being inserted on the extreme right-end of the
** tree, in other words, when the new entry will become the largest

  int rc;                              /* Return Code */
  Pgno pgnoNew;                        /* Page number of pNew */

  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  assert( sqlite3PagerIswriteable(pParent->pDbPage) );
  assert( pPage->nOverflow==1 );


  if( pPage->nCell==0 ) return SQLITE_CORRUPT_BKPT;  /* dbfuzz001.test */

  /* Allocate a new page. This page will become the right-sibling of 
  ** pPage. Make the parent page writable, so that the new divider cell
  ** may be inserted. If both these operations are successful, proceed.
  */
  rc = allocateBtreePage(pBt, &pNew, &pgnoNew, 0, 0);

  if( rc==SQLITE_OK ){

    u8 *pOut = &pSpace[4];
    u8 *pCell = pPage->apOvfl[0];
    u16 szCell = pPage->xCellSize(pPage, pCell);
    u8 *pStop;
    CellArray b;

    assert( sqlite3PagerIswriteable(pNew->pDbPage) );
    assert( CORRUPT_DB || pPage->aData[0]==(PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF) );
    zeroPage(pNew, PTF_INTKEY|PTF_LEAFDATA|PTF_LEAF);
    b.nCell = 1;
    b.pRef = pPage;
    b.apCell = &pCell;
    b.szCell = &szCell;
    b.apEnd[0] = pPage->aDataEnd;
    b.ixNx[0] = 2;
    rc = rebuildPage(&b, 0, 1, pNew);
    if( NEVER(rc) ){
      releasePage(pNew);
      return rc;
    }
    pNew->nFree = pBt->usableSize - pNew->cellOffset - 2 - szCell;

    /* If this is an auto-vacuum database, update the pointer map
    ** with entries for the new page, and any pointer from the 
    ** cell on the page to an overflow page. If either of these
    ** operations fails, the return code is set, but the contents
    ** of the parent page are still manipulated by thh code below.
    ** That is Ok, at this point the parent page is guaranteed to
    ** be marked as dirty. Returning an error code will cause a
    ** rollback, undoing any changes made to the parent page.
    */
    if( ISAUTOVACUUM ){
      ptrmapPut(pBt, pgnoNew, PTRMAP_BTREE, pParent->pgno, &rc);
      if( szCell>pNew->minLocal ){
        ptrmapPutOvflPtr(pNew, pNew, pCell, &rc);
      }
    }
  
    /* Create a divider cell to insert into pParent. The divider cell
    ** consists of a 4-byte page number (the page number of pPage) and
    ** a variable length key value (which must be the same value as the
    ** largest key on pPage).

  memset(abDone, 0, sizeof(abDone));
  b.nCell = 0;
  b.apCell = 0;
  pBt = pParent->pBt;
  assert( sqlite3_mutex_held(pBt->mutex) );
  assert( sqlite3PagerIswriteable(pParent->pDbPage) );





  /* At this point pParent may have at most one overflow cell. And if
  ** this overflow cell is present, it must be the cell with 
  ** index iParentIdx. This scenario comes about when this function
  ** is called (indirectly) from sqlite3BtreeDelete().
  */
  assert( pParent->nOverflow==0 || pParent->nOverflow==1 );
  assert( pParent->nOverflow==0 || pParent->aiOvfl[0]==iParentIdx );

  **    szNew[i]: Spaced used on the i-th sibling page.
  **   cntNew[i]: Index in b.apCell[] and b.szCell[] for the first cell to
  **              the right of the i-th sibling page.
  ** usableSpace: Number of bytes of space available on each sibling.
  ** 
  */
  usableSpace = pBt->usableSize - 12 + leafCorrection;
  for(i=k=0; i<nOld; i++, k++){
    MemPage *p = apOld[i];
    b.apEnd[k] = p->aDataEnd;
    b.ixNx[k] = cntOld[i];
    if( !leafData ){
      k++;
      b.apEnd[k] = pParent->aDataEnd;
      b.ixNx[k] = cntOld[i]+1;
    }
    szNew[i] = usableSpace - p->nFree;
    for(j=0; j<p->nOverflow; j++){
      szNew[i] += 2 + p->xCellSize(p, p->apOvfl[j]);
    }
    cntNew[i] = cntOld[i];
  }
  k = nOld;

  **
  ** If the sibling pages are not leaves, then the pointer map entry 
  ** associated with the right-child of each sibling may also need to be 
  ** updated. This happens below, after the sibling pages have been 
  ** populated, not here.
  */
  if( ISAUTOVACUUM ){
    MemPage *pOld;
    MemPage *pNew = pOld = apNew[0];
    u8 *aOld = pNew->aData;
    int cntOldNext = pNew->nCell + pNew->nOverflow;
    int usableSize = pBt->usableSize;
    int iNew = 0;
    int iOld = 0;

    for(i=0; i<b.nCell; i++){
      u8 *pCell = b.apCell[i];
      if( i==cntOldNext ){
        pOld = (++iOld)<nNew ? apNew[iOld] : apOld[iOld];
        cntOldNext += pOld->nCell + pOld->nOverflow + !leafData;
        aOld = pOld->aData;
      }
      if( i==cntNew[iNew] ){
        pNew = apNew[++iNew];
        if( !leafData ) continue;
      }

       || pNew->pgno!=aPgno[iOld]
       || !SQLITE_WITHIN(pCell,aOld,&aOld[usableSize])
      ){
        if( !leafCorrection ){
          ptrmapPut(pBt, get4byte(pCell), PTRMAP_BTREE, pNew->pgno, &rc);
        }
        if( cachedCellSize(&b,i)>pNew->minLocal ){
          ptrmapPutOvflPtr(pNew, pOld, pCell, &rc);
        }
        if( rc ) goto balance_cleanup;
      }
    }
  }

  /* Insert new divider cells into pParent. */

                                 iAmt-nData);
      if( rc ) return rc;
      iAmt = nData;
    }
    if( memcmp(pDest, ((u8*)pX->pData) + iOffset, iAmt)!=0 ){
      int rc = sqlite3PagerWrite(pPage->pDbPage);
      if( rc ) return rc;
      /* In a corrupt database, it is possible for the source and destination
      ** buffers to overlap.  This is harmless since the database is already
      ** corrupt but it does cause valgrind and ASAN warnings.  So use
      ** memmove(). */
      memmove(pDest, ((u8*)pX->pData) + iOffset, iAmt);
    }
  }
  return SQLITE_OK;
}

/*
** Overwrite the cell that cursor pCur is pointing to with fresh content

  **
  ** Or, if the current delete will not cause a rebalance, then the cursor
  ** will be left in CURSOR_SKIPNEXT state pointing to the entry immediately
  ** before or after the deleted entry. In this case set bSkipnext to true.  */
  if( bPreserve ){
    if( !pPage->leaf 
     || (pPage->nFree+cellSizePtr(pPage,pCell)+2)>(int)(pBt->usableSize*2/3)
     || pPage->nCell==1  /* See dbfuzz001.test for a test case */
    ){
      /* A b-tree rebalance will be required after deleting this entry.
      ** Save the cursor key.  */
      rc = saveCursorKey(pCur);
      if( rc ) return rc;
    }else{
      bSkipnext = 1;

    N--;
    if( sqlite3PagerGet(pCheck->pPager, (Pgno)iPage, &pOvflPage, 0) ){
      checkAppendMsg(pCheck, "failed to get page %d", 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 %d", 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
          checkRef(pCheck, iFreePage);

  int nRoot,    /* Number of entries in aRoot[] */
  int mxErr,    /* Stop reporting errors after this many */
  int *pnErr    /* Write number of errors seen to this variable */
){
  Pgno i;
  IntegrityCk sCheck;
  BtShared *pBt = p->pBt;
  u64 savedDbFlags = pBt->db->flags;
  char zErr[100];
  VVA_ONLY( int nRef );

  sqlite3BtreeEnter(p);
  assert( p->inTrans>TRANS_NONE && pBt->inTransaction>TRANS_NONE );
  VVA_ONLY( nRef = sqlite3PagerRefcount(pBt->pPager) );
  assert( nRef>=0 );

  }else if( get4byte(&pBt->pPage1->aData[64])!=0 ){
    checkAppendMsg(&sCheck,
      "incremental_vacuum enabled with a max rootpage of zero"
    );
  }
#endif
  testcase( pBt->db->flags & SQLITE_CellSizeCk );
  pBt->db->flags &= ~(u64)SQLITE_CellSizeCk;
  for(i=0; (int)i<nRoot && sCheck.mxErr; i++){
    i64 notUsed;
    if( aRoot[i]==0 ) continue;
#ifndef SQLITE_OMIT_AUTOVACUUM
    if( pBt->autoVacuum && aRoot[i]>1 ){
      checkPtrmap(&sCheck, aRoot[i], PTRMAP_ROOTPAGE, 0);
    }

** and MEM_Blob values may be discarded, MEM_Int, MEM_Real, and MEM_Null
** values are preserved.
**
** Return SQLITE_OK on success or an error code (probably SQLITE_NOMEM)
** if unable to complete the resizing.
*/
SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int szNew){
  assert( CORRUPT_DB || szNew>0 );
  assert( (pMem->flags & MEM_Dyn)==0 || pMem->szMalloc==0 );
  if( pMem->szMalloc<szNew ){
    return sqlite3VdbeMemGrow(pMem, szNew, 0);
  }
  assert( (pMem->flags & MEM_Dyn)==0 );
  pMem->z = pMem->zMalloc;
  pMem->flags &= (MEM_Null|MEM_Int|MEM_Real);

  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  u32 offset,       /* Offset from the start of data to return bytes from. */
  u32 amt,          /* Number of bytes to return. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  int rc;
  pMem->flags = MEM_Null;
  if( sqlite3BtreeMaxRecordSize(pCur)<offset+amt ){
    return SQLITE_CORRUPT_BKPT;
  }
  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+1)) ){
    rc = sqlite3BtreePayload(pCur, offset, amt, pMem->z);
    if( rc==SQLITE_OK ){
      pMem->z[amt] = 0;   /* Overrun area used when reading malformed records */
      pMem->flags = MEM_Blob;
      pMem->n = (int)amt;
    }else{

#endif
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
  else if( op==TK_FUNCTION && pCtx!=0 ){
    rc = valueFromFunction(db, pExpr, enc, affinity, &pVal, pCtx);
  }
#endif
  else if( op==TK_TRUEFALSE ){
    pVal = valueNew(db, pCtx);
    if( pVal ){
      pVal->flags = MEM_Int;
      pVal->u.i = pExpr->u.zToken[4]==0;
    }
  }

  *ppVal = pVal;
  return rc;

no_mem:
#ifdef SQLITE_ENABLE_STAT3_OR_STAT4

  p->pPrev = 0;
  db->pVdbe = p;
  p->magic = VDBE_MAGIC_INIT;
  p->pParse = pParse;
  pParse->pVdbe = p;
  assert( pParse->aLabel==0 );
  assert( pParse->nLabel==0 );
  assert( p->nOpAlloc==0 );
  assert( pParse->szOpAlloc==0 );
  sqlite3VdbeAddOp2(p, OP_Init, 0, 1);
  return p;
}

/*
** Change the error string stored in Vdbe.zErrMsg

  if( p==0 ) return;
  p->prepFlags = prepFlags;
  if( (prepFlags & SQLITE_PREPARE_SAVESQL)==0 ){
    p->expmask = 0;
  }
  assert( p->zSql==0 );
  p->zSql = sqlite3DbStrNDup(p->db, z, n);
}

#ifdef SQLITE_ENABLE_NORMALIZE
/*
** Add a new element to the Vdbe->pDblStr list.
*/
SQLITE_PRIVATE void sqlite3VdbeAddDblquoteStr(sqlite3 *db, Vdbe *p, const char *z){
  if( p ){

    int n = sqlite3Strlen30(z);
    DblquoteStr *pStr = sqlite3DbMallocRawNN(db,
                            sizeof(*pStr)+n+1-sizeof(pStr->z));
    if( pStr ){
      pStr->pNextStr = p->pDblStr;
      p->pDblStr = pStr;
      memcpy(pStr->z, z, n+1);
    }
  }
}
#endif

#ifdef SQLITE_ENABLE_NORMALIZE
/*
** zId of length nId is a double-quoted identifier.  Check to see if
** that identifier is really used as a string literal.
*/
SQLITE_PRIVATE int sqlite3VdbeUsesDoubleQuotedString(
  Vdbe *pVdbe,            /* The prepared statement */
  const char *zId         /* The double-quoted identifier, already dequoted */
){
  DblquoteStr *pStr;
  assert( zId!=0 );
  if( pVdbe->pDblStr==0 ) return 0;
  for(pStr=pVdbe->pDblStr; pStr; pStr=pStr->pNextStr){
    if( strcmp(zId, pStr->z)==0 ) return 1;
  }
  return 0;
}
#endif

/*
** Swap all content between two VDBE structures.
*/
SQLITE_PRIVATE void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
  Vdbe tmp, *pTmp;
  char *zTmp;
  assert( pA->db==pB->db );
  tmp = *pA;
  *pA = *pB;
  *pB = tmp;
  pTmp = pA->pNext;
  pA->pNext = pB->pNext;
  pB->pNext = pTmp;
  pTmp = pA->pPrev;
  pA->pPrev = pB->pPrev;
  pB->pPrev = pTmp;
  zTmp = pA->zSql;
  pA->zSql = pB->zSql;
  pB->zSql = zTmp;
#if 0
  zTmp = pA->zNormSql;
  pA->zNormSql = pB->zNormSql;
  pB->zNormSql = zTmp;
#endif
  pB->expmask = pA->expmask;
  pB->prepFlags = pA->prepFlags;
  memcpy(pB->aCounter, pA->aCounter, sizeof(pB->aCounter));
  pB->aCounter[SQLITE_STMTSTATUS_REPREPARE]++;
}

/*
** Resize the Vdbe.aOp array so that it is at least nOp elements larger 
** than its current size. nOp is guaranteed to be less than or equal
** to 1024/sizeof(Op).
**
** If an out-of-memory error occurs while resizing the array, return
** SQLITE_NOMEM. In this case Vdbe.aOp and Vdbe.nOpAlloc remain 
** unchanged (this is so that any opcodes already allocated can be 
** correctly deallocated along with the rest of the Vdbe).
*/
static int growOpArray(Vdbe *v, int nOp){
  VdbeOp *pNew;
  Parse *p = v->pParse;

  /* The SQLITE_TEST_REALLOC_STRESS compile-time option is designed to force
  ** more frequent reallocs and hence provide more opportunities for 
  ** simulated OOM faults.  SQLITE_TEST_REALLOC_STRESS is generally used
  ** during testing only.  With SQLITE_TEST_REALLOC_STRESS grow the op array
  ** by the minimum* amount required until the size reaches 512.  Normal
  ** operation (without SQLITE_TEST_REALLOC_STRESS) is to double the current
  ** size of the op array or add 1KB of space, whichever is smaller. */
#ifdef SQLITE_TEST_REALLOC_STRESS
  int nNew = (v->nOpAlloc>=512 ? v->nOpAlloc*2 : v->nOpAlloc+nOp);
#else
  int nNew = (v->nOpAlloc ? v->nOpAlloc*2 : (int)(1024/sizeof(Op)));
  UNUSED_PARAMETER(nOp);
#endif

  /* Ensure that the size of a VDBE does not grow too large */
  if( nNew > p->db->aLimit[SQLITE_LIMIT_VDBE_OP] ){
    sqlite3OomFault(p->db);
    return SQLITE_NOMEM;
  }

  assert( nOp<=(1024/sizeof(Op)) );
  assert( nNew>=(v->nOpAlloc+nOp) );
  pNew = sqlite3DbRealloc(p->db, v->aOp, nNew*sizeof(Op));
  if( pNew ){
    p->szOpAlloc = sqlite3DbMallocSize(p->db, pNew);
    v->nOpAlloc = p->szOpAlloc/sizeof(Op);
    v->aOp = pNew;
  }
  return (pNew ? SQLITE_OK : SQLITE_NOMEM_BKPT);
}

#ifdef SQLITE_DEBUG
/* This routine is just a convenient place to set a breakpoint that will

**    p1, p2, p3      Operands
**
** Use the sqlite3VdbeResolveLabel() function to fix an address and
** the sqlite3VdbeChangeP4() function to change the value of the P4
** operand.
*/
static SQLITE_NOINLINE int growOp3(Vdbe *p, int op, int p1, int p2, int p3){
  assert( p->nOpAlloc<=p->nOp );
  if( growOpArray(p, 1) ) return 1;
  assert( p->nOpAlloc>p->nOp );
  return sqlite3VdbeAddOp3(p, op, p1, p2, p3);
}
SQLITE_PRIVATE int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  assert( op>=0 && op<0xff );
  if( p->nOpAlloc<=i ){
    return growOp3(p, op, p1, p2, p3);
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = (u8)op;
  pOp->p5 = 0;
  pOp->p1 = p1;

  VdbeOp *pOp;
  if( pParse->addrExplain==0 ) return 0;
  pOp = sqlite3VdbeGetOp(pParse->pVdbe, pParse->addrExplain);
  return pOp->p2;
}

/*
** Set a debugger breakpoint on the following routine in order to
** monitor the EXPLAIN QUERY PLAN code generation.
*/
#if defined(SQLITE_DEBUG)
SQLITE_PRIVATE void sqlite3ExplainBreakpoint(const char *z1, const char *z2){
  (void)z1;
  (void)z2;
}
#endif

/*
** Add a new OP_ opcode.
**
** If the bPush flag is true, then make this opcode the parent for
** subsequent Explains until sqlite3VdbeExplainPop() is called.
*/
SQLITE_PRIVATE void sqlite3VdbeExplain(Parse *pParse, u8 bPush, const char *zFmt, ...){
#ifndef 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 )
#endif
  {
    char *zMsg;
    Vdbe *v;
    va_list ap;
    int iThis;
    va_start(ap, zFmt);
    zMsg = sqlite3VMPrintf(pParse->db, zFmt, ap);
    va_end(ap);
    v = pParse->pVdbe;
    iThis = v->nOp;
    sqlite3VdbeAddOp4(v, OP_Explain, iThis, pParse->addrExplain, 0,
                      zMsg, P4_DYNAMIC);
    sqlite3ExplainBreakpoint(bPush?"PUSH":"", sqlite3VdbeGetOp(v,-1)->p4.z);
    if( bPush){
      pParse->addrExplain = iThis;
    }
  }
}

/*
** Pop the EXPLAIN QUERY PLAN stack one level.
*/
SQLITE_PRIVATE void sqlite3VdbeExplainPop(Parse *pParse){
  sqlite3ExplainBreakpoint("POP", 0);
  pParse->addrExplain = sqlite3VdbeExplainParent(pParse);
}
#endif /* SQLITE_OMIT_EXPLAIN */

/*
** Add an OP_ParseSchema opcode.  This routine is broken out from
** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees

** the label is resolved to a specific address, the VDBE will scan
** through its operation list and change all values of P2 which match
** the label into the resolved address.
**
** The VDBE knows that a P2 value is a label because labels are
** always negative and P2 values are suppose to be non-negative.
** Hence, a negative P2 value is a label that has yet to be resolved.
** (Later:) This is only true for opcodes that have the OPFLG_JUMP
** property.
**
** Variable usage notes:
**
**     Parse.aLabel[x]     Stores the address that the x-th label resolves
**                         into.  For testing (SQLITE_DEBUG), unresolved
**                         labels stores -1, but that is not required.
**     Parse.nLabelAlloc   Number of slots allocated to Parse.aLabel[]
**     Parse.nLabel        The *negative* of the number of labels that have
**                         been issued.  The negative is stored because
**                         that gives a performance improvement over storing
**                         the equivalent positive value.
*/
SQLITE_PRIVATE int sqlite3VdbeMakeLabel(Parse *pParse){

  return --pParse->nLabel;









}

/*
** Resolve label "x" to be the address of the next instruction to
** be inserted.  The parameter "x" must have been obtained from
** a prior call to sqlite3VdbeMakeLabel().
*/
static SQLITE_NOINLINE void resizeResolveLabel(Parse *p, Vdbe *v, int j){
  int nNewSize = 10 - p->nLabel;
  p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
                     nNewSize*sizeof(p->aLabel[0]));
  if( p->aLabel==0 ){
    p->nLabelAlloc = 0;
  }else{
#ifdef SQLITE_DEBUG
    int i;
    for(i=p->nLabelAlloc; i<nNewSize; i++) p->aLabel[i] = -1;
#endif
    p->nLabelAlloc = nNewSize;
    p->aLabel[j] = v->nOp;
  }
}
SQLITE_PRIVATE void sqlite3VdbeResolveLabel(Vdbe *v, int x){
  Parse *p = v->pParse;
  int j = ADDR(x);
  assert( v->magic==VDBE_MAGIC_INIT );
  assert( j<-p->nLabel );
  assert( j>=0 );

#ifdef SQLITE_DEBUG
  if( p->db->flags & SQLITE_VdbeAddopTrace ){
    printf("RESOLVE LABEL %d to %d\n", x, v->nOp);
  }
#endif
  if( p->nLabelAlloc + p->nLabel < 0 ){
    resizeResolveLabel(p,v,j);
  }else{
    assert( p->aLabel[j]==(-1) ); /* Labels may only be resolved once */
    p->aLabel[j] = v->nOp;
  }
}

/*
** Mark the VDBE as one that can only be run one time.

  VdbeOpIter sIter;
  memset(&sIter, 0, sizeof(sIter));
  sIter.v = v;

  while( (pOp = opIterNext(&sIter))!=0 ){
    int opcode = pOp->opcode;
    if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 
     || opcode==OP_VDestroy
     || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
      && ((pOp->p1)!=SQLITE_OK && pOp->p2==OE_Abort))
    ){
      hasAbort = 1;
      break;
    }
    if( opcode==OP_CreateBtree && pOp->p3==BTREE_INTKEY ) hasCreateTable = 1;
    if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;
#ifndef SQLITE_OMIT_FOREIGN_KEY

#endif
        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 );
            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

** SQLITE_TEST_REALLOC_STRESS).  This interface is used during testing
** to verify that certain calls to sqlite3VdbeAddOpList() can never
** fail due to a OOM fault and hence that the return value from
** sqlite3VdbeAddOpList() will always be non-NULL.
*/
#if defined(SQLITE_DEBUG) && !defined(SQLITE_TEST_REALLOC_STRESS)
SQLITE_PRIVATE void sqlite3VdbeVerifyNoMallocRequired(Vdbe *p, int N){
  assert( p->nOp + N <= p->nOpAlloc );
}
#endif

/*
** Verify that the VM passed as the only argument does not contain
** an OP_ResultRow opcode. Fail an assert() if it does. This is used
** by code in pragma.c to ensure that the implementation of certain

  VdbeOpList const *aOp,       /* The opcodes to be added */
  int iLineno                  /* Source-file line number of first opcode */
){
  int i;
  VdbeOp *pOut, *pFirst;
  assert( nOp>0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOp + nOp > p->nOpAlloc && growOpArray(p, nOp) ){
    return 0;
  }
  pFirst = pOut = &p->aOp[p->nOp];
  for(i=0; i<nOp; i++, aOp++, pOut++){
    pOut->opcode = aOp->opcode;
    pOut->p1 = aOp->p1;
    pOut->p2 = aOp->p2;

  ** requirements by reusing the opcode array tail, then the second
  ** pass will fill in the remainder using a fresh memory allocation.  
  **
  ** This two-pass approach that reuses as much memory as possible from
  ** the leftover memory at the end of the opcode array.  This can significantly
  ** reduce the amount of memory held by a prepared statement.
  */

  x.nNeeded = 0;
  p->aMem = allocSpace(&x, 0, nMem*sizeof(Mem));
  p->aVar = allocSpace(&x, 0, nVar*sizeof(Mem));
  p->apArg = allocSpace(&x, 0, nArg*sizeof(Mem*));
  p->apCsr = allocSpace(&x, 0, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  p->anExec = allocSpace(&x, 0, p->nOp*sizeof(i64));
#endif
  if( x.nNeeded ){
    x.pSpace = p->pFree = sqlite3DbMallocRawNN(db, x.nNeeded);
    x.nFree = x.nNeeded;
    if( !db->mallocFailed ){
      p->aMem = allocSpace(&x, p->aMem, nMem*sizeof(Mem));
      p->aVar = allocSpace(&x, p->aVar, nVar*sizeof(Mem));
      p->apArg = allocSpace(&x, p->apArg, nArg*sizeof(Mem*));
      p->apCsr = allocSpace(&x, p->apCsr, nCursor*sizeof(VdbeCursor*));
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
      p->anExec = allocSpace(&x, p->anExec, p->nOp*sizeof(i64));
#endif
    }
  }

  p->pVList = pParse->pVList;
  pParse->pVList =  0;
  p->explain = pParse->explain;
  if( db->mallocFailed ){
    p->nVar = 0;
    p->nCursor = 0;

        }else if( rc!=SQLITE_OK ){
          p->rc = rc;
          sqlite3RollbackAll(db, SQLITE_OK);
          p->nChange = 0;
        }else{
          db->nDeferredCons = 0;
          db->nDeferredImmCons = 0;
          db->flags &= ~(u64)SQLITE_DeferFKs;
          sqlite3CommitInternalChanges(db);
        }
      }else{
        sqlite3RollbackAll(db, SQLITE_OK);
        p->nChange = 0;
      }
      db->nStatement = 0;

    sqlite3DbFree(db, p->pFree);
  }
  vdbeFreeOpArray(db, p->aOp, p->nOp);
  sqlite3DbFree(db, p->aColName);
  sqlite3DbFree(db, p->zSql);
#ifdef SQLITE_ENABLE_NORMALIZE
  sqlite3DbFree(db, p->zNormSql);
  {
    DblquoteStr *pThis, *pNext;
    for(pThis=p->pDblStr; pThis; pThis=pNext){
      pNext = pThis->pNextStr;
      sqlite3DbFree(db, pThis);
    }
  }
#endif
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  {
    int i;
    for(i=0; i<p->nScan; i++){
      sqlite3DbFree(db, p->aScan[i].zName);
    }

SQLITE_PRIVATE void sqlite3VdbeRecordUnpack(
  KeyInfo *pKeyInfo,     /* Information about the record format */
  int nKey,              /* Size of the binary record */
  const void *pKey,      /* The binary record */
  UnpackedRecord *p      /* Populate this structure before returning. */
){
  const unsigned char *aKey = (const unsigned char *)pKey;
  u32 d; 
  u32 idx;                        /* Offset in aKey[] to read from */
  u16 u;                          /* Unsigned loop counter */
  u32 szHdr;
  Mem *pMem = p->aMem;

  p->default_rc = 0;
  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
  idx = getVarint32(aKey, szHdr);
  d = szHdr;
  u = 0;
  while( idx<szHdr && d<=(u32)nKey ){
    u32 serial_type;

    idx += getVarint32(&aKey[idx], serial_type);
    pMem->enc = pKeyInfo->enc;
    pMem->db = pKeyInfo->db;
    /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
    pMem->szMalloc = 0;
    pMem->z = 0;
    d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
    pMem++;
    if( (++u)>=p->nField ) break;
  }
  if( d>(u32)nKey && u ){
    assert( CORRUPT_DB );
    /* In a corrupt record entry, the last pMem might have been set up using 
    ** uninitialized memory. Overwrite its value with NULL, to prevent
    ** warnings from MSAN. */
    sqlite3VdbeMemSetNull(pMem-1);
  }
  assert( u<=pKeyInfo->nKeyField + 1 );
  p->nField = u;
}

#ifdef SQLITE_DEBUG
/*
** This function compares two index or table record keys in the same way

    /* Verify that there is enough key space remaining to avoid
    ** a buffer overread.  The "d1+serial_type1+2" subexpression will
    ** always be greater than or equal to the amount of required key space.
    ** Use that approximation to avoid the more expensive call to
    ** sqlite3VdbeSerialTypeLen() in the common case.
    */
    if( d1+(u64)serial_type1+2>(u64)nKey1
     && d1+(u64)sqlite3VdbeSerialTypeLen(serial_type1)>(u64)nKey1 
    ){
      break;
    }

    /* Extract the values to be compared.
    */
    d1 += sqlite3VdbeSerialGet(&aKey1[d1], serial_type1, &mem1);

    /* Do the comparison
    */
    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i],
                           pKeyInfo->nAllField>i ? pKeyInfo->aColl[i] : 0);
    if( rc!=0 ){
      assert( mem1.szMalloc==0 );  /* See comment below */
      if( pKeyInfo->aSortOrder[i] ){
        rc = -rc;  /* Invert the result for DESC sort order. */
      }
      goto debugCompareEnd;
    }

    szHdr1 = aKey1[0];
    d1 = szHdr1 + sqlite3VdbeSerialTypeLen(s1);
    i = 1;
    pRhs++;
  }else{
    idx1 = getVarint32(aKey1, szHdr1);
    d1 = szHdr1;
    i = 0;
  }
  if( d1>(unsigned)nKey1 ){ 
    pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
    return 0;  /* Corruption */
  }



  VVA_ONLY( mem1.szMalloc = 0; ) /* Only needed by assert() statements */
  assert( pPKey2->pKeyInfo->nAllField>=pPKey2->nField 
       || CORRUPT_DB );
  assert( pPKey2->pKeyInfo->aSortOrder!=0 );
  assert( pPKey2->pKeyInfo->nKeyField>0 );
  assert( idx1<=szHdr1 || CORRUPT_DB );

        rc = -1;
      }else if( !(serial_type & 0x01) ){
        rc = +1;
      }else{
        mem1.n = (serial_type - 12) / 2;
        testcase( (d1+mem1.n)==(unsigned)nKey1 );
        testcase( (d1+mem1.n+1)==(unsigned)nKey1 );
        if( (d1+mem1.n) > (unsigned)nKey1
         || (pKeyInfo = pPKey2->pKeyInfo)->nAllField<=i
        ){
          pPKey2->errCode = (u8)SQLITE_CORRUPT_BKPT;
          return 0;                /* Corruption */
        }else if( pKeyInfo->aColl[i] ){
          mem1.enc = pKeyInfo->enc;
          mem1.db = pKeyInfo->db;
          mem1.flags = MEM_Str;
          mem1.z = (char*)&aKey1[d1];
          rc = vdbeCompareMemString(
              &mem1, pRhs, pKeyInfo->aColl[i], &pPKey2->errCode
          );

** Invoke the profile callback.  This routine is only called if we already
** know that the profile callback is defined and needs to be invoked.
*/
static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
  sqlite3_int64 iNow;
  sqlite3_int64 iElapse;
  assert( p->startTime>0 );
  assert( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0 );
  assert( db->init.busy==0 );
  assert( p->zSql!=0 );
  sqlite3OsCurrentTimeInt64(db->pVfs, &iNow);
  iElapse = (iNow - p->startTime)*1000000;
#ifndef SQLITE_OMIT_DEPRECATED  	
  if( db->xProfile ){
    db->xProfile(db->pProfileArg, p->zSql, iElapse);
  }
#endif
  if( db->mTrace & SQLITE_TRACE_PROFILE ){
    db->xTrace(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
  }
  p->startTime = 0;
}
/*
** The checkProfileCallback(DB,P) macro checks to see if a profile callback

  /* Check that malloc() has not failed. If it has, return early. */
  db = p->db;
  if( db->mallocFailed ){
    p->rc = SQLITE_NOMEM;
    return SQLITE_NOMEM_BKPT;
  }

  if( p->pc<0 && p->expired ){
    p->rc = SQLITE_SCHEMA;
    rc = SQLITE_ERROR;
    goto end_of_step;
  }
  if( p->pc<0 ){
    /* If there are no other statements currently running, then
    ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
    ** from interrupting a statement that has not yet started.
    */
    if( db->nVdbeActive==0 ){
      db->u1.isInterrupted = 0;
    }

    assert( db->nVdbeWrite>0 || db->autoCommit==0 
        || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
    );

#ifndef SQLITE_OMIT_TRACE
    if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
        && !db->init.busy && p->zSql ){
      sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
    }else{
      assert( p->startTime==0 );
    }
#endif

#endif /* SQLITE_OMIT_EXPLAIN */
  {
    db->nVdbeExec++;
    rc = sqlite3VdbeExec(p);
    db->nVdbeExec--;
  }

  if( rc!=SQLITE_ROW ){
#ifndef SQLITE_OMIT_TRACE
    /* If the statement completed successfully, invoke the profile callback */
    checkProfileCallback(db, p);
#endif

    if( rc==SQLITE_DONE && db->autoCommit ){
      assert( p->rc==SQLITE_OK );
      p->rc = doWalCallbacks(db);
      if( p->rc!=SQLITE_OK ){
        rc = SQLITE_ERROR;
      }
    }
  }

  db->errCode = rc;
  if( SQLITE_NOMEM==sqlite3ApiExit(p->db, p->rc) ){
    p->rc = SQLITE_NOMEM_BKPT;
  }
end_of_step:
  /* At this point local variable rc holds the value that should be 
  ** returned if this statement was compiled using the legacy 
  ** sqlite3_prepare() interface. According to the docs, this can only
  ** be one of the values in the first assert() below. Variable p->rc 
  ** contains the value that would be returned if sqlite3_finalize() 
  ** were called on statement p.
  */
  assert( rc==SQLITE_ROW  || rc==SQLITE_DONE   || rc==SQLITE_ERROR 
       || (rc&0xff)==SQLITE_BUSY || rc==SQLITE_MISUSE
  );
  assert( (p->rc!=SQLITE_ROW && p->rc!=SQLITE_DONE) || p->rc==p->rcApp );

  if( rc!=SQLITE_ROW 
   && rc!=SQLITE_DONE
   && (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0
  ){
    /* If this statement was prepared using saved SQL and an 
    ** error has occurred, then return the error code in p->rc to the
    ** caller. Set the error code in the database handle to the same value.
    */ 
    rc = sqlite3VdbeTransferError(p);
  }

    sqlite3_mutex_leave(p->db->mutex);
    return SQLITE_RANGE;
  }
  i--;
  pVar = &p->aVar[i];
  sqlite3VdbeMemRelease(pVar);
  pVar->flags = MEM_Null;
  p->db->errCode = SQLITE_OK;

  /* If the bit corresponding to this variable in Vdbe.expmask is set, then 
  ** binding a new value to this variable invalidates the current query plan.
  **
  ** IMPLEMENTATION-OF: R-48440-37595 If the specific value bound to host
  ** parameter in the WHERE clause might influence the choice of query plan
  ** for a statement, then the statement will be automatically recompiled,

#ifdef SQLITE_ENABLE_NORMALIZE
/*
** Return the normalized SQL associated with a prepared statement.
*/
SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt){
  Vdbe *p = (Vdbe *)pStmt;
  if( p==0 ) return 0;
  if( p->zNormSql==0 && ALWAYS(p->zSql!=0) ){
    sqlite3_mutex_enter(p->db->mutex);
    p->zNormSql = sqlite3Normalize(p, p->zSql);
    sqlite3_mutex_leave(p->db->mutex);
  }
  return p->zNormSql;
}
#endif /* SQLITE_ENABLE_NORMALIZE */

#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
/*
** Allocate and populate an UnpackedRecord structure based on the serialized
** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure

  VdbeCursor *pCx = 0;
  nByte = 
      ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 
      (eCurType==CURTYPE_BTREE?sqlite3BtreeCursorSize():0);

  assert( iCur>=0 && iCur<p->nCursor );
  if( p->apCsr[iCur] ){ /*OPTIMIZATION-IF-FALSE*/
    /* Before calling sqlite3VdbeFreeCursor(), ensure the isEphemeral flag
    ** is clear. Otherwise, if this is an ephemeral cursor created by 
    ** OP_OpenDup, the cursor will not be closed and will still be part
    ** of a BtShared.pCursor list.  */
    p->apCsr[iCur]->isEphemeral = 0;
    sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
    p->apCsr[iCur] = 0;
  }
  if( SQLITE_OK==sqlite3VdbeMemClearAndResize(pMem, nByte) ){
    p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;
    memset(pCx, 0, offsetof(VdbeCursor,pAltCursor));
    pCx->eCurType = eCurType;

** interpret as a string if we want to).  Compute its corresponding
** numeric type, if has one.  Set the pMem->u.r and pMem->u.i fields
** accordingly.
*/
static u16 SQLITE_NOINLINE computeNumericType(Mem *pMem){
  assert( (pMem->flags & (MEM_Int|MEM_Real))==0 );
  assert( (pMem->flags & (MEM_Str|MEM_Blob))!=0 );
  ExpandBlob(pMem);
  if( sqlite3AtoF(pMem->z, &pMem->u.r, pMem->n, pMem->enc)==0 ){
    return 0;
  }
  if( sqlite3Atoi64(pMem->z, &pMem->u.i, pMem->n, pMem->enc)==0 ){
    return MEM_Int;
  }
  return MEM_Real;

      case OP_Divide: {
        /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
        if( rA==(double)0 ) goto arithmetic_result_is_null;
        rB /= rA;
        break;
      }
      default: {
        iA = sqlite3VdbeIntValue(pIn1);
        iB = sqlite3VdbeIntValue(pIn2);
        if( iA==0 ) goto arithmetic_result_is_null;
        if( iA==-1 ) iA = 1;
        rB = (double)(iB % iA);
        break;
      }
    }
#ifdef SQLITE_OMIT_FLOATING_POINT

    if( pOp->p5 & SQLITE_NULLEQ ){
      /* If SQLITE_NULLEQ is set (which will only happen if the operator is
      ** OP_Eq or OP_Ne) then take the jump or not depending on whether
      ** or not both operands are null.
      */
      assert( pOp->opcode==OP_Eq || pOp->opcode==OP_Ne );
      assert( (flags1 & MEM_Cleared)==0 );
      assert( (pOp->p5 & SQLITE_JUMPIFNULL)==0 || CORRUPT_DB );
      testcase( (pOp->p5 & SQLITE_JUMPIFNULL)!=0 );
      if( (flags1&flags3&MEM_Null)!=0
       && (flags3&MEM_Cleared)==0
      ){
        res = 0;  /* Operands are equal */
      }else{
        res = 1;  /* Operands are not equal */
      }

  pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  pCx->isEphemeral = 1;
  pCx->pKeyInfo = pOrig->pKeyInfo;
  pCx->isTable = pOrig->isTable;
  pCx->pgnoRoot = pOrig->pgnoRoot;
  rc = sqlite3BtreeCursor(pOrig->pBtx, pCx->pgnoRoot, BTREE_WRCSR,
                          pCx->pKeyInfo, pCx->uc.pCursor);
  /* The sqlite3BtreeCursor() routine can only fail for the first cursor
  ** opened for a database.  Since there is already an open cursor when this
  ** opcode is run, the sqlite3BtreeCursor() cannot fail */
  assert( rc==SQLITE_OK );
  break;
}


/* Opcode: OpenEphemeral P1 P2 * P4 P5
** Synopsis: nColumn=P2
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if 
** the main database is read-only.  The ephemeral
** table is deleted automatically when the cursor is closed.
**
** If the cursor P1 is already opened on an ephemeral table, the table
** is cleared (all content is erased).
**
** P2 is the number of columns in the ephemeral table.
** The cursor points to a BTree table if P4==0 and to a BTree index
** if P4 is not 0.  If P4 is not NULL, it points to a KeyInfo structure
** that defines the format of keys in the index.
**
** The P5 parameter can be a mask of the BTREE_* flags defined

      SQLITE_OPEN_READWRITE |
      SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE |
      SQLITE_OPEN_DELETEONCLOSE |
      SQLITE_OPEN_TRANSIENT_DB;
  assert( pOp->p1>=0 );
  assert( pOp->p2>=0 );
  pCx = p->apCsr[pOp->p1];
  if( pCx ){
    /* If the ephermeral table is already open, erase all existing content
    ** so that the table is empty again, rather than creating a new table. */
    rc = sqlite3BtreeClearTable(pCx->pBtx, pCx->pgnoRoot, 0);
  }else{
    pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, CURTYPE_BTREE);
    if( pCx==0 ) goto no_mem;
    pCx->nullRow = 1;
    pCx->isEphemeral = 1;
    rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBtx, 
                          BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5,
                          vfsFlags);
    if( rc==SQLITE_OK ){
      rc = sqlite3BtreeBeginTrans(pCx->pBtx, 1, 0);
    }
    if( rc==SQLITE_OK ){
      /* If a transient index is required, create it by calling
      ** sqlite3BtreeCreateTable() with the BTREE_BLOBKEY flag before
      ** opening it. If a transient table is required, just use the
      ** automatically created table with root-page 1 (an BLOB_INTKEY table).
      */
      if( (pCx->pKeyInfo = pKeyInfo = pOp->p4.pKeyInfo)!=0 ){

        assert( pOp->p4type==P4_KEYINFO );
        rc = sqlite3BtreeCreateTable(pCx->pBtx, (int*)&pCx->pgnoRoot,
                                     BTREE_BLOBKEY | pOp->p5); 
        if( rc==SQLITE_OK ){
          assert( pCx->pgnoRoot==MASTER_ROOT+1 );
          assert( pKeyInfo->db==db );
          assert( pKeyInfo->enc==ENC(db) );
          rc = sqlite3BtreeCursor(pCx->pBtx, pCx->pgnoRoot, BTREE_WRCSR,
                                  pKeyInfo, pCx->uc.pCursor);
        }
        pCx->isTable = 0;
      }else{
        pCx->pgnoRoot = MASTER_ROOT;
        rc = sqlite3BtreeCursor(pCx->pBtx, MASTER_ROOT, BTREE_WRCSR,
                                0, pCx->uc.pCursor);
        pCx->isTable = 1;
      }
    }
    pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  }
  if( rc ) goto abort_due_to_error;

  break;
}

/* Opcode: SorterOpen P1 P2 P3 P4 *
**
** This opcode works like OP_OpenEphemeral except that it opens
** a transient index that is specifically designed to sort large

case OP_NotExists:          /* jump, in3 */
  pIn3 = &aMem[pOp->p3];
  assert( (pIn3->flags & MEM_Int)!=0 || pOp->opcode==OP_SeekRowid );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
#ifdef SQLITE_DEBUG
  if( pOp->opcode==OP_SeekRowid ) pC->seekOp = OP_SeekRowid;
#endif
  assert( pC->isTable );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  res = 0;
  iKey = pIn3->u.i;

  assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );

  /* The Next opcode is only used after SeekGT, SeekGE, Rewind, and Found.
  ** The Prev opcode is only used after SeekLT, SeekLE, and Last. */
  assert( pOp->opcode!=OP_Next
       || pC->seekOp==OP_SeekGT || pC->seekOp==OP_SeekGE
       || pC->seekOp==OP_Rewind || pC->seekOp==OP_Found 
       || pC->seekOp==OP_NullRow|| pC->seekOp==OP_SeekRowid);
  assert( pOp->opcode!=OP_Prev
       || pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE
       || pC->seekOp==OP_Last 
       || pC->seekOp==OP_NullRow);

  rc = pOp->p4.xAdvance(pC->uc.pCursor, pOp->p3);
next_tail:

       db->aDb[iDb].zDbSName, zMaster, pOp->p4.z);
    if( zSql==0 ){
      rc = SQLITE_NOMEM_BKPT;
    }else{
      assert( db->init.busy==0 );
      db->init.busy = 1;
      initData.rc = SQLITE_OK;
      initData.nInitRow = 0;
      assert( !db->mallocFailed );
      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
      if( rc==SQLITE_OK ) rc = initData.rc;
      if( rc==SQLITE_OK && initData.nInitRow==0 ){
        /* The OP_ParseSchema opcode with a non-NULL P4 argument should parse
        ** at least one SQL statement. Any less than that indicates that
        ** the sqlite_master table is corrupt. */
        rc = SQLITE_CORRUPT_BKPT;
      }
      sqlite3DbFreeNN(db, zSql);
      db->init.busy = 0;
    }
  }
  if( rc ){
    sqlite3ResetAllSchemasOfConnection(db);
    if( rc==SQLITE_NOMEM ){

  p->apCsr = (VdbeCursor **)&aMem[p->nMem];
  pFrame->aOnce = (u8*)&p->apCsr[pProgram->nCsr];
  memset(pFrame->aOnce, 0, (pProgram->nOp + 7)/8);
  p->aOp = aOp = pProgram->aOp;
  p->nOp = pProgram->nOp;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  p->anExec = 0;
#endif
#ifdef SQLITE_DEBUG
  /* Verify that second and subsequent executions of the same trigger do not
  ** try to reuse register values from the first use. */
  {
    int i;
    for(i=0; i<p->nMem; i++){
      aMem[i].pScopyFrom = 0;  /* Prevent false-positive AboutToChange() errs */
      aMem[i].flags |= MEM_Undefined; /* Cause a fault if this reg is reused */
    }
  }
#endif
  pOp = &aOp[-1];

  break;
}

/* Opcode: Param P1 P2 * * *

  sqlite3VdbeChangeEncoding(pOut, encoding);
  if( rc ) goto abort_due_to_error;
  break;
};
#endif /* SQLITE_OMIT_PRAGMA */

#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
/* Opcode: Vacuum P1 P2 * * *
**
** Vacuum the entire database P1.  P1 is 0 for "main", and 2 or more
** for an attached database.  The "temp" database may not be vacuumed.
**
** If P2 is not zero, then it is a register holding a string which is
** the file into which the result of vacuum should be written.  When
** P2 is zero, the vacuum overwrites the original database.
*/
case OP_Vacuum: {
  assert( p->readOnly==0 );
  rc = sqlite3RunVacuum(&p->zErrMsg, db, pOp->p1,
                        pOp->p2 ? &aMem[pOp->p2] : 0);
  if( rc ) goto abort_due_to_error;
  break;
}
#endif

#if !defined(SQLITE_OMIT_AUTOVACUUM)
/* Opcode: IncrVacuum P1 P2 * * *

** P4 is the name of a virtual table in database P1.  Call the xDestroy method
** of that table.
*/
case OP_VDestroy: {
  db->nVDestroy++;
  rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
  db->nVDestroy--;
  assert( p->errorAction==OE_Abort && p->usesStmtJournal );
  if( rc ) goto abort_due_to_error;
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VOpen P1 * * P4 *

  assert( pName->flags & MEM_Str );
  testcase( pName->enc==SQLITE_UTF8 );
  testcase( pName->enc==SQLITE_UTF16BE );
  testcase( pName->enc==SQLITE_UTF16LE );
  rc = sqlite3VdbeChangeEncoding(pName, SQLITE_UTF8);
  if( rc ) goto abort_due_to_error;
  rc = pVtab->pModule->xRename(pVtab, pName->z);
  if( isLegacy==0 ) db->flags &= ~(u64)SQLITE_LegacyAlter;
  sqlite3VtabImportErrmsg(p, pVtab);
  p->expired = 0;
  if( rc ) goto abort_due_to_error;
  break;
}
#endif

** an SQL statement.
*/
/* #include "sqliteInt.h" */
/* #include <stdlib.h> */
/* #include <string.h> */


#if !defined(SQLITE_OMIT_WINDOWFUNC)
/*
** Walk all expressions linked into the list of Window objects passed
** as the second argument.
*/
static int walkWindowList(Walker *pWalker, Window *pList){
  Window *pWin;
  for(pWin=pList; pWin; pWin=pWin->pNextWin){
    if( sqlite3WalkExprList(pWalker, pWin->pOrderBy) ) return WRC_Abort;
    if( sqlite3WalkExprList(pWalker, pWin->pPartition) ) return WRC_Abort;
    if( sqlite3WalkExpr(pWalker, pWin->pFilter) ) return WRC_Abort;
  }
  return WRC_Continue;
}
#endif

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

      }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
      }else if( pExpr->x.pList ){
        if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
      }
#ifndef SQLITE_OMIT_WINDOWFUNC
      if( ExprHasProperty(pExpr, EP_WinFunc) ){



        if( walkWindowList(pWalker, pExpr->y.pWin) ) return WRC_Abort;
      }
#endif
    }
    break;
  }
  return WRC_Continue;
}

SQLITE_PRIVATE int sqlite3WalkSelectExpr(Walker *pWalker, Select *p){
  if( sqlite3WalkExprList(pWalker, p->pEList) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pWhere) ) return WRC_Abort;
  if( sqlite3WalkExprList(pWalker, p->pGroupBy) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pHaving) ) return WRC_Abort;
  if( sqlite3WalkExprList(pWalker, p->pOrderBy) ) return WRC_Abort;
  if( sqlite3WalkExpr(pWalker, p->pLimit) ) return WRC_Abort;
#if !defined(SQLITE_OMIT_WINDOWFUNC) && !defined(SQLITE_OMIT_ALTERTABLE)
  {
    Parse *pParse = pWalker->pParse;
    if( pParse && IN_RENAME_OBJECT ){
      int rc = walkWindowList(pWalker, p->pWinDefn);
      assert( rc==WRC_Continue );
      return rc;
    }
  }
#endif
  return WRC_Continue;
}

/*
** Walk the parse trees associated with all subqueries in the
** FROM clause of SELECT statement p.  Do not invoke the select
** callback on p, but do invoke it on each FROM clause subquery

  db = pParse->db;
  pDup = sqlite3ExprDup(db, pOrig, 0);
  if( pDup!=0 ){
    if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery);
    if( pExpr->op==TK_COLLATE ){
      pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken);
    }


    /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This 
    ** prevents ExprDelete() from deleting the Expr structure itself,
    ** allowing it to be repopulated by the memcpy() on the following line.
    ** The pExpr->u.zToken might point into memory that will be freed by the
    ** sqlite3DbFree(db, pDup) on the last line of this block, so be sure to
    ** make a copy of the token before doing the sqlite3DbFree().

  **
  ** Because no reference was made to outer contexts, the pNC->nRef
  ** fields are not changed in any context.
  */
  if( cnt==0 && zTab==0 ){
    assert( pExpr->op==TK_ID );
    if( ExprHasProperty(pExpr,EP_DblQuoted) ){
      /* If a double-quoted identifier does not match any known column name,
      ** then treat it as a string.
      **
      ** This hack was added in the early days of SQLite in a misguided attempt
      ** to be compatible with MySQL 3.x, which used double-quotes for strings.
      ** I now sorely regret putting in this hack. The effect of this hack is
      ** that misspelled identifier names are silently converted into strings
      ** rather than causing an error, to the frustration of countless
      ** programmers. To all those frustrated programmers, my apologies.
      **
      ** Someday, I hope to get rid of this hack. Unfortunately there is
      ** a huge amount of legacy SQL that uses it. So for now, we just
      ** issue a warning.
      */
      sqlite3_log(SQLITE_WARNING,
        "double-quoted string literal: \"%w\"", zCol);
#ifdef SQLITE_ENABLE_NORMALIZE
      sqlite3VdbeAddDblquoteStr(db, pParse->pVdbe, zCol);
#endif
      pExpr->op = TK_STRING;
      pExpr->y.pTab = 0;
      return WRC_Prune;
    }
    if( sqlite3ExprIdToTrueFalse(pExpr) ){
      return WRC_Prune;
    }

        }
      }
      sqlite3WalkExprList(pWalker, pList);
      if( is_agg ){
#ifndef SQLITE_OMIT_WINDOWFUNC
        if( pExpr->y.pWin ){
          Select *pSel = pNC->pWinSelect;
          sqlite3WindowUpdate(pParse, pSel->pWinDefn, pExpr->y.pWin, pDef);
          sqlite3WalkExprList(pWalker, pExpr->y.pWin->pPartition);
          sqlite3WalkExprList(pWalker, pExpr->y.pWin->pOrderBy);
          sqlite3WalkExpr(pWalker, pExpr->y.pWin->pFilter);

          if( 0==pSel->pWin 
           || 0==sqlite3WindowCompare(pParse, pSel->pWin, pExpr->y.pWin) 
          ){
            pExpr->y.pWin->pNextWin = pSel->pWin;
            pSel->pWin = pExpr->y.pWin;
          }
          pNC->ncFlags |= NC_AllowWin;

        if( iCol<=0 || iCol>pEList->nExpr ){
          resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
          return 1;
        }
      }else{
        iCol = resolveAsName(pParse, pEList, pE);
        if( iCol==0 ){
          /* Now test if expression pE matches one of the values returned
          ** by pSelect. In the usual case this is done by duplicating the 
          ** expression, resolving any symbols in it, and then comparing
          ** it against each expression returned by the SELECT statement.
          ** Once the comparisons are finished, the duplicate expression
          ** is deleted.
          **
          ** Or, if this is running as part of an ALTER TABLE operation,
          ** resolve the symbols in the actual expression, not a duplicate.
          ** And, if one of the comparisons is successful, leave the expression
          ** as is instead of transforming it to an integer as in the usual
          ** case. This allows the code in alter.c to modify column
          ** refererences within the ORDER BY expression as required.  */
          if( IN_RENAME_OBJECT ){
            pDup = pE;
          }else{
            pDup = sqlite3ExprDup(db, pE, 0);
          }
          if( !db->mallocFailed ){
            assert(pDup);
            iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup);
          }
          if( !IN_RENAME_OBJECT ){
            sqlite3ExprDelete(db, pDup);
          }
        }
      }
      if( iCol>0 ){
        /* Convert the ORDER BY term into an integer column number iCol,
        ** taking care to preserve the COLLATE clause if it exists */
        if( !IN_RENAME_OBJECT ){
          Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
          if( pNew==0 ) return 1;
          pNew->flags |= EP_IntValue;
          pNew->u.iValue = iCol;
          if( pItem->pExpr==pE ){
            pItem->pExpr = pNew;
          }else{
            Expr *pParent = pItem->pExpr;
            assert( pParent->op==TK_COLLATE );
            while( pParent->pLeft->op==TK_COLLATE ) pParent = pParent->pLeft;
            assert( pParent->pLeft==pE );
            pParent->pLeft = pNew;
          }
          sqlite3ExprDelete(db, pE);
          pItem->u.x.iOrderByCol = (u16)iCol;
        }
        pItem->done = 1;
      }else{
        moreToDo = 1;
      }
    }
    pSelect = pSelect->pNext;
  }

        if( ExprHasProperty(pItem->pExpr, EP_Agg) ){
          sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "
              "the GROUP BY clause");
          return WRC_Abort;
        }
      }
    }

    if( IN_RENAME_OBJECT ){
      Window *pWin;
      for(pWin=p->pWinDefn; pWin; pWin=pWin->pNextWin){
        if( sqlite3ResolveExprListNames(&sNC, pWin->pOrderBy)
         || sqlite3ResolveExprListNames(&sNC, pWin->pPartition)
        ){
          return WRC_Abort;
        }
      }
    }

    /* If this is part of a compound SELECT, check that it has the right
    ** number of expressions in the select list. */
    if( p->pNext && p->pEList->nExpr!=p->pNext->pEList->nExpr ){
      sqlite3SelectWrongNumTermsError(pParse, p->pNext);
      return WRC_Abort;
    }

  w.xSelectCallback2 = 0;
  w.pParse = pParse;
  w.u.pNC = pOuterNC;
  sqlite3WalkSelect(&w, p);
}

/*
** Resolve names in expressions that can only reference a single table
** or which cannot reference any tables at all.  Examples:
**
**    (1)   CHECK constraints
**    (2)   WHERE clauses on partial indices
**    (3)   Expressions in indexes on expressions
**    (4)   Expression arguments to VACUUM INTO.
**
** In all cases except (4), the Expr.iTable value for Expr.op==TK_COLUMN
** nodes of the expression is set to -1 and the Expr.iColumn value is
** set to the column number.  In case (4), TK_COLUMN nodes cause an error.
**
** Any errors cause an error message to be set in pParse.
*/
SQLITE_PRIVATE int sqlite3ResolveSelfReference(
  Parse *pParse,      /* Parsing context */
  Table *pTab,        /* The table being referenced, or NULL */
  int type,           /* NC_IsCheck or NC_PartIdx or NC_IdxExpr, or 0 */
  Expr *pExpr,        /* Expression to resolve.  May be NULL. */
  ExprList *pList     /* Expression list to resolve.  May be NULL. */
){
  SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
  NameContext sNC;                /* Name context for pParse->pNewTable */
  int rc;

  assert( type==0 || pTab!=0 );
  assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr || pTab==0 );
  memset(&sNC, 0, sizeof(sNC));
  memset(&sSrc, 0, sizeof(sSrc));
  if( pTab ){
    sSrc.nSrc = 1;
    sSrc.a[0].zName = pTab->zName;
    sSrc.a[0].pTab = pTab;
    sSrc.a[0].iCursor = -1;
  }
  sNC.pParse = pParse;
  sNC.pSrcList = &sSrc;
  sNC.ncFlags = type;
  if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc;
  if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList);
  return rc;
}

/************** End of resolve.c *********************************************/
/************** Begin file expr.c ********************************************/
/*
** 2001 September 15
**

SQLITE_PRIVATE CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
  sqlite3 *db = pParse->db;
  CollSeq *pColl = 0;
  Expr *p = pExpr;
  while( p ){
    int op = p->op;
    if( p->flags & EP_Generic ) break;
    if( op==TK_REGISTER ) op = p->op2;
    if( (op==TK_AGG_COLUMN || op==TK_COLUMN || op==TK_TRIGGER)

     && p->y.pTab!=0
    ){
      /* op==TK_REGISTER && p->y.pTab!=0 happens when pExpr was originally
      ** a TK_COLUMN but was previously evaluated and cached in a register */
      int j = p->iColumn;
      if( j>=0 ){
        const char *zColl = p->y.pTab->aCol[j].zColl;
        pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
      }
      break;
    }
    if( op==TK_CAST || op==TK_UPLUS ){
      p = p->pLeft;
      continue;
    }
    if( op==TK_COLLATE ){
      pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
      break;
    }
    if( p->flags & EP_Collate ){
      if( p->pLeft && (p->pLeft->flags & EP_Collate)!=0 ){
        p = p->pLeft;
      }else{

      pRet->iColumn = iField;
      pRet->pLeft = pVector;
    }
    assert( pRet==0 || pRet->iTable==0 );
  }else{
    if( pVector->op==TK_VECTOR ) pVector = pVector->x.pList->a[iField].pExpr;
    pRet = sqlite3ExprDup(pParse->db, pVector, 0);
    sqlite3RenameTokenRemap(pParse, pRet, pVector);
  }
  return pRet;
}

/*
** If expression pExpr is of type TK_SELECT, generate code to evaluate
** it. Return the register in which the result is stored (or, if the 
** sub-select returns more than one column, the first in an array
** of registers in which the result is stored).
**
** If pExpr is not a TK_SELECT expression, return 0.
*/
static int exprCodeSubselect(Parse *pParse, Expr *pExpr){
  int reg = 0;
#ifndef SQLITE_OMIT_SUBQUERY
  if( pExpr->op==TK_SELECT ){
    reg = sqlite3CodeSubselect(pParse, pExpr);
  }
#endif
  return reg;
}

/*
** Argument pVector points to a vector expression - either a TK_VECTOR

  Expr *pLeft = pExpr->pLeft;
  Expr *pRight = pExpr->pRight;
  int nLeft = sqlite3ExprVectorSize(pLeft);
  int i;
  int regLeft = 0;
  int regRight = 0;
  u8 opx = op;
  int addrDone = sqlite3VdbeMakeLabel(pParse);

  if( nLeft!=sqlite3ExprVectorSize(pRight) ){
    sqlite3ErrorMsg(pParse, "row value misused");
    return;
  }
  assert( pExpr->op==TK_EQ || pExpr->op==TK_NE 
       || pExpr->op==TK_IS || pExpr->op==TK_ISNOT 

        pNew->u.iValue = iValue;
      }else{
        pNew->u.zToken = (char*)&pNew[1];
        assert( pToken->z!=0 || pToken->n==0 );
        if( pToken->n ) memcpy(pNew->u.zToken, pToken->z, pToken->n);
        pNew->u.zToken[pToken->n] = 0;
        if( dequote && sqlite3Isquote(pNew->u.zToken[0]) ){

          sqlite3DequoteExpr(pNew);
        }
      }
    }
#if SQLITE_MAX_EXPR_DEPTH>0
    pNew->nHeight = 1;
#endif  
  }

SQLITE_PRIVATE Expr *sqlite3PExpr(
  Parse *pParse,          /* Parsing context */
  int op,                 /* Expression opcode */
  Expr *pLeft,            /* Left operand */
  Expr *pRight            /* Right operand */
){
  Expr *p;
  if( op==TK_AND && pParse->nErr==0 && !IN_RENAME_OBJECT ){
    /* Take advantage of short-circuit false optimization for AND */
    p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
  }else{
    p = sqlite3DbMallocRawNN(pParse->db, sizeof(Expr));
    if( p ){
      memset(p, 0, sizeof(Expr));
      p->op = op & TKFLG_MASK;

** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
*/
static int exprStructSize(Expr *p){
  if( ExprHasProperty(p, EP_TokenOnly) ) return EXPR_TOKENONLYSIZE;
  if( ExprHasProperty(p, EP_Reduced) ) return EXPR_REDUCEDSIZE;
  return EXPR_FULLSIZE;
}

/*
** Copy the complete content of an Expr node, taking care not to read
** past the end of the structure for a reduced-size version of the source
** Expr.
*/
static void exprNodeCopy(Expr *pDest, Expr *pSrc){
  memset(pDest, 0, sizeof(Expr));
  memcpy(pDest, pSrc, exprStructSize(pSrc));
}

/*
** The dupedExpr*Size() routines each return the number of bytes required
** to store a copy of an expression or expression tree.  They differ in
** how much of the tree is measured.
**
**     dupedExprStructSize()     Size of only the Expr structure 

    }
  }
  return pRet;
}
#else
# define withDup(x,y) 0
#endif

#ifndef SQLITE_OMIT_WINDOWFUNC
/*
** The gatherSelectWindows() procedure and its helper routine
** gatherSelectWindowsCallback() are used to scan all the expressions
** an a newly duplicated SELECT statement and gather all of the Window
** objects found there, assembling them onto the linked list at Select->pWin.
*/
static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_FUNCTION && pExpr->y.pWin!=0 ){
    assert( ExprHasProperty(pExpr, EP_WinFunc) );
    pExpr->y.pWin->pNextWin = pWalker->u.pSelect->pWin;
    pWalker->u.pSelect->pWin = pExpr->y.pWin;
  }
  return WRC_Continue;
}
static int gatherSelectWindowsSelectCallback(Walker *pWalker, Select *p){
  return p==pWalker->u.pSelect ? WRC_Continue : WRC_Prune;
}
static void gatherSelectWindows(Select *p){
  Walker w;
  w.xExprCallback = gatherSelectWindowsCallback;
  w.xSelectCallback = gatherSelectWindowsSelectCallback;
  w.xSelectCallback2 = 0;
  w.pParse = 0;
  w.u.pSelect = p;
  sqlite3WalkSelect(&w, p);
}
#endif


/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements.  The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**

    pNew->addrOpenEphm[0] = -1;
    pNew->addrOpenEphm[1] = -1;
    pNew->nSelectRow = p->nSelectRow;
    pNew->pWith = withDup(db, p->pWith);
#ifndef SQLITE_OMIT_WINDOWFUNC
    pNew->pWin = 0;
    pNew->pWinDefn = sqlite3WindowListDup(db, p->pWinDefn);
    if( p->pWin ) gatherSelectWindows(pNew);
#endif
    pNew->selId = p->selId;
    *pp = pNew;
    pp = &pNew->pPrior;
    pNext = pNew;
  }

    /* Remember the size of the LHS in iTable so that we can check that
    ** the RHS and LHS sizes match during code generation. */
    pFirst->iTable = pColumns->nId;
  }

vector_append_error:
  if( IN_RENAME_OBJECT ){
    sqlite3RenameExprUnmap(pParse, pExpr);
  }
  sqlite3ExprDelete(db, pExpr);
  sqlite3IdListDelete(db, pColumns);
  return pList;
}

/*
** Set the sort order for the last element on the given ExprList.

/*
** If the input expression is an ID with the name "true" or "false"
** then convert it into an TK_TRUEFALSE term.  Return non-zero if
** the conversion happened, and zero if the expression is unaltered.
*/
SQLITE_PRIVATE int sqlite3ExprIdToTrueFalse(Expr *pExpr){
  assert( pExpr->op==TK_ID || pExpr->op==TK_STRING );
  if( !ExprHasProperty(pExpr, EP_Quoted)
   && (sqlite3StrICmp(pExpr->u.zToken, "true")==0
       || sqlite3StrICmp(pExpr->u.zToken, "false")==0)
  ){
    pExpr->op = TK_TRUEFALSE;
    return 1;
  }
  return 0;
}

** be a small performance hit but is otherwise harmless.  On the other
** hand, a false negative (returning FALSE when the result could be NULL)
** will likely result in an incorrect answer.  So when in doubt, return
** TRUE.
*/
SQLITE_PRIVATE int sqlite3ExprCanBeNull(const Expr *p){
  u8 op;
  while( p->op==TK_UPLUS || p->op==TK_UMINUS ){
    p = p->pLeft;
  }
  op = p->op;
  if( op==TK_REGISTER ) op = p->op2;
  switch( op ){
    case TK_INTEGER:
    case TK_STRING:
    case TK_FLOAT:
    case TK_BLOB:

*/
SQLITE_PRIVATE int sqlite3IsRowid(const char *z){
  if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
  if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
  if( sqlite3StrICmp(z, "OID")==0 ) return 1;
  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 manifested into a transient
** table, then return NULL.

*/
#ifndef SQLITE_OMIT_SUBQUERY
SQLITE_PRIVATE int sqlite3FindInIndex(
  Parse *pParse,             /* Parsing context */
  Expr *pX,                  /* The right-hand side (RHS) of the IN operator */
  u32 inFlags,               /* IN_INDEX_LOOP, _MEMBERSHIP, and/or _NOOP_OK */
  int *prRhsHasNull,         /* Register holding NULL status.  See notes */
  int *aiMap,                /* Mapping from Index fields to RHS fields */
  int *piTab                 /* OUT: index to use */
){
  Select *p;                            /* SELECT to the right of IN operator */
  int eType = 0;                        /* Type of RHS table. IN_INDEX_* */
  int iTab = pParse->nTab++;            /* Cursor of the RHS table */
  int mustBeUnique;                     /* True if RHS must be unique */
  Vdbe *v = sqlite3GetVdbe(pParse);     /* Virtual machine being coded */

      if( affinity_ok ){
        /* Search for an existing index that will work for this IN operator */
        for(pIdx=pTab->pIndex; pIdx && eType==0; pIdx=pIdx->pNext){
          Bitmask colUsed;      /* Columns of the index used */
          Bitmask mCol;         /* Mask for the current column */
          if( pIdx->nColumn<nExpr ) continue;
          if( pIdx->pPartIdxWhere!=0 ) continue;
          /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
          ** BITMASK(nExpr) without overflowing */
          testcase( pIdx->nColumn==BMS-2 );
          testcase( pIdx->nColumn==BMS-1 );
          if( pIdx->nColumn>=BMS-1 ) continue;
          if( mustBeUnique ){
            if( pIdx->nKeyCol>nExpr

      pParse->nQueryLoop = 0;
      if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
        eType = IN_INDEX_ROWID;
      }
    }else if( prRhsHasNull ){
      *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
    }
    assert( pX->op==TK_IN );
    sqlite3CodeRhsOfIN(pParse, pX, iTab, eType==IN_INDEX_ROWID);
    if( rMayHaveNull ){
      sqlite3SetHasNullFlag(v, iTab, rMayHaveNull);
    }
    pParse->nQueryLoop = savedNQueryLoop;


  }

  if( aiMap && eType!=IN_INDEX_INDEX_ASC && eType!=IN_INDEX_INDEX_DESC ){
    int i, n;
    n = sqlite3ExprVectorSize(pX->pLeft);
    for(i=0; i<n; i++) aiMap[i] = i;
  }
  *piTab = iTab;
  return eType;
}
#endif

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Argument pExpr is an (?, ?...) IN(...) expression. This 

  }else
#endif
  {
    sqlite3ErrorMsg(pParse, "row value misused");
  }
}

#ifndef SQLITE_OMIT_SUBQUERY
/*
** Generate code that will construct an ephemeral table containing all terms
** in the RHS of an IN operator.  The IN operator can be in either of two
** forms:
**


**     x IN (4,5,11)              -- IN operator with list on right-hand side
**     x IN (SELECT a FROM b)     -- IN operator with subquery on the right
**
** The pExpr parameter is the IN operator.  The cursor number for the
** constructed ephermeral table is returned.  The first time the ephemeral
** table is computed, the cursor number is also stored in pExpr->iTable,
** however the cursor number returned might not be the same, as it might
** have been duplicated using OP_OpenDup.
**
** If parameter isRowid is non-zero, then LHS of the IN operator is guaranteed
** to be a non-null integer. In this case, the ephemeral table can be an
** table B-Tree that keyed by only integers.  The more general cases uses
** an index B-Tree which can have arbitrary keys, but is slower to both
** read and write.
**
** If the LHS expression ("x" in the examples) is a column value, or
** the SELECT statement returns a column value, then the affinity of that
** column is used to build the index keys. If both 'x' and the
** SELECT... statement are columns, then numeric affinity is used
** if either column has NUMERIC or INTEGER affinity. If neither
** 'x' nor the SELECT... statement are columns, then numeric affinity
** is used.
*/
SQLITE_PRIVATE void sqlite3CodeRhsOfIN(
  Parse *pParse,          /* Parsing context */
  Expr *pExpr,            /* The IN operator */
  int iTab,               /* Use this cursor number */
  int isRowid             /* If true, LHS is a rowid */
){
  int addrOnce = 0;           /* Address of the OP_Once instruction at top */
  int addr;                   /* Address of OP_OpenEphemeral instruction */
  Expr *pLeft;                /* the LHS of the IN operator */
  KeyInfo *pKeyInfo = 0;      /* Key information */
  int nVal;                   /* Size of vector pLeft */
  Vdbe *v;                    /* The prepared statement under construction */

  v = pParse->pVdbe;
  assert( v!=0 );

  /* The evaluation of the IN must be repeated every time it
  ** is encountered if any of the following is true:
  **
  **    *  The right-hand side is a correlated subquery
  **    *  The right-hand side is an expression list containing variables
  **    *  We are inside a trigger
  **
  ** If all of the above are false, then we can compute the RHS just once
  ** and reuse it many names.
  */
  if( !ExprHasProperty(pExpr, EP_VarSelect) && pParse->iSelfTab==0 ){
    /* Reuse of the RHS is allowed */
    /* If this routine has already been coded, but the previous code
    ** might not have been invoked yet, so invoke it now as a subroutine. 
    */
    if( ExprHasProperty(pExpr, EP_Subrtn) ){
      addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
        ExplainQueryPlan((pParse, 0, "REUSE LIST SUBQUERY %d",
              pExpr->x.pSelect->selId));
      }
      sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
                        pExpr->y.sub.iAddr);
      sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
      sqlite3VdbeJumpHere(v, addrOnce);
      return;
    }

    /* Begin coding the subroutine */
    ExprSetProperty(pExpr, EP_Subrtn);
    pExpr->y.sub.regReturn = ++pParse->nMem;
    pExpr->y.sub.iAddr =
      sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
    VdbeComment((v, "return address"));

    addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
  }

  /* Check to see if this is a vector IN operator */
  pLeft = pExpr->pLeft;
  nVal = sqlite3ExprVectorSize(pLeft);
  assert( !isRowid || nVal==1 );

  /* Construct the ephemeral table that will contain the content of
  ** RHS of the IN operator.
  */
  pExpr->iTable = iTab;
  addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, 
      pExpr->iTable, (isRowid?0:nVal));
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
  if( ExprHasProperty(pExpr, EP_xIsSelect) ){
    VdbeComment((v, "Result of SELECT %u", pExpr->x.pSelect->selId));
  }else{
    VdbeComment((v, "RHS of IN operator"));
  }
#endif
  pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, nVal, 1);

  if( ExprHasProperty(pExpr, EP_xIsSelect) ){
    /* Case 1:     expr IN (SELECT ...)
    **
    ** Generate code to write the results of the select into the temporary
    ** table allocated and opened above.
    */
    Select *pSelect = pExpr->x.pSelect;
    ExprList *pEList = pSelect->pEList;

    ExplainQueryPlan((pParse, 1, "%sLIST SUBQUERY %d",
        addrOnce?"":"CORRELATED ", pSelect->selId
    ));
    assert( !isRowid );
    /* If the LHS and RHS of the IN operator do not match, that
    ** error will have been caught long before we reach this point. */
    if( ALWAYS(pEList->nExpr==nVal) ){
      SelectDest dest;
      int i;
      sqlite3SelectDestInit(&dest, SRT_Set, iTab);
      dest.zAffSdst = exprINAffinity(pParse, pExpr);
      pSelect->iLimit = 0;
      testcase( pSelect->selFlags & SF_Distinct );
      testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
      if( sqlite3Select(pParse, pSelect, &dest) ){
        sqlite3DbFree(pParse->db, dest.zAffSdst);
        sqlite3KeyInfoUnref(pKeyInfo);
        return;
      }
      sqlite3DbFree(pParse->db, dest.zAffSdst);
      assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
      assert( pEList!=0 );
      assert( pEList->nExpr>0 );
      assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
      for(i=0; i<nVal; i++){
        Expr *p = sqlite3VectorFieldSubexpr(pLeft, i);
        pKeyInfo->aColl[i] = sqlite3BinaryCompareCollSeq(
            pParse, p, pEList->a[i].pExpr
        );
      }
    }
  }else if( ALWAYS(pExpr->x.pList!=0) ){
    /* Case 2:     expr IN (exprlist)
    **
    ** For each expression, build an index key from the evaluation and
    ** store it in the temporary table. If <expr> is a column, then use
    ** that columns affinity when building index keys. If <expr> is not
    ** a column, use numeric affinity.
    */
    char affinity;            /* Affinity of the LHS of the IN */
    int i;
    ExprList *pList = pExpr->x.pList;
    struct ExprList_item *pItem;
    int r1, r2, r3;
    affinity = sqlite3ExprAffinity(pLeft);
    if( !affinity ){
      affinity = SQLITE_AFF_BLOB;
    }
    if( pKeyInfo ){
      assert( sqlite3KeyInfoIsWriteable(pKeyInfo) );
      pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
    }

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

      /* If the expression is not constant then we will need to
      ** disable the test that was generated above that makes sure
      ** this code only executes once.  Because for a non-constant
      ** expression we need to rerun this code each time.
      */
      if( addrOnce && !sqlite3ExprIsConstant(pE2) ){
        sqlite3VdbeChangeToNoop(v, addrOnce);
        addrOnce = 0;
      }

      /* Evaluate the expression and insert it into the temp table */
      if( isRowid && sqlite3ExprIsInteger(pE2, &iValToIns) ){
        sqlite3VdbeAddOp3(v, OP_InsertInt, iTab, r2, iValToIns);
      }else{
        r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);
        if( isRowid ){
          sqlite3VdbeAddOp2(v, OP_MustBeInt, r3,
                            sqlite3VdbeCurrentAddr(v)+2);
          VdbeCoverage(v);
          sqlite3VdbeAddOp3(v, OP_Insert, iTab, r2, r3);
        }else{
          sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
          sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r2, r3, 1);
        }
      }
    }
    sqlite3ReleaseTempReg(pParse, r1);
    sqlite3ReleaseTempReg(pParse, r2);
  }
  if( pKeyInfo ){
    sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO);
  }
  if( addrOnce ){
    sqlite3VdbeJumpHere(v, addrOnce);
    /* Subroutine return */
    sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
    sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
  }
}
#endif /* SQLITE_OMIT_SUBQUERY */

/*
** Generate code for scalar subqueries used as a subquery expression
** or EXISTS operator:
**
**     (SELECT a FROM b)          -- subquery
**     EXISTS (SELECT a FROM b)   -- EXISTS subquery
**
** The pExpr parameter is the SELECT or EXISTS operator to be coded.
**
** The register that holds the result.  For a multi-column SELECT, 
** the result is stored in a contiguous array of registers and the
** return value is the register of the left-most result column.
** Return 0 if an error occurs.
*/
#ifndef SQLITE_OMIT_SUBQUERY
SQLITE_PRIVATE int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
  int addrOnce = 0;           /* Address of OP_Once at top of subroutine */

  int rReg = 0;               /* Register storing resulting */
  Select *pSel;               /* SELECT statement to encode */
  SelectDest dest;            /* How to deal with SELECT result */

  int nReg;                   /* Registers to allocate */
  Expr *pLimit;               /* New limit expression */

  Vdbe *v = pParse->pVdbe;
  assert( v!=0 );
  testcase( pExpr->op==TK_EXISTS );
  testcase( pExpr->op==TK_SELECT );
  assert( pExpr->op==TK_EXISTS || pExpr->op==TK_SELECT );
  assert( ExprHasProperty(pExpr, EP_xIsSelect) );
  pSel = pExpr->x.pSelect;

  /* The evaluation of the EXISTS/SELECT must be repeated every time it
  ** is encountered if any of the following is true:
  **
  **    *  The right-hand side is a correlated subquery
  **    *  The right-hand side is an expression list containing variables
  **    *  We are inside a trigger
  **
  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasProperty(pExpr, EP_VarSelect) ){


    /* If this routine has already been coded, then invoke it as a






    ** subroutine. */





















    if( ExprHasProperty(pExpr, EP_Subrtn) ){








      ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));








      sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
                        pExpr->y.sub.iAddr);






      return pExpr->iTable;
    }

































    /* Begin coding the subroutine */







    ExprSetProperty(pExpr, EP_Subrtn);









    pExpr->y.sub.regReturn = ++pParse->nMem;


    pExpr->y.sub.iAddr =



      sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;

    VdbeComment((v, "return address"));











    addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
  }

  







  /* For a SELECT, generate code to put the values for all columns of
  ** the first row into an array of registers and return the index of
  ** the first register.
  **
  ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
  ** into a register and return that register number.
  **
  ** In both cases, the query is augmented with "LIMIT 1".  Any 
  ** preexisting limit is discarded in place of the new LIMIT 1.
  */











  ExplainQueryPlan((pParse, 1, "%sSCALAR SUBQUERY %d",
        addrOnce?"":"CORRELATED ", pSel->selId));
  nReg = pExpr->op==TK_SELECT ? pSel->pEList->nExpr : 1;
  sqlite3SelectDestInit(&dest, 0, pParse->nMem+1);
  pParse->nMem += nReg;
  if( pExpr->op==TK_SELECT ){
    dest.eDest = SRT_Mem;
    dest.iSdst = dest.iSDParm;
    dest.nSdst = nReg;
    sqlite3VdbeAddOp3(v, OP_Null, 0, dest.iSDParm, dest.iSDParm+nReg-1);
    VdbeComment((v, "Init subquery result"));
  }else{
    dest.eDest = SRT_Exists;
    sqlite3VdbeAddOp2(v, OP_Integer, 0, dest.iSDParm);
    VdbeComment((v, "Init EXISTS result"));
  }
  pLimit = sqlite3ExprAlloc(pParse->db, TK_INTEGER,&sqlite3IntTokens[1], 0);
  if( pSel->pLimit ){
    sqlite3ExprDelete(pParse->db, pSel->pLimit->pLeft);
    pSel->pLimit->pLeft = pLimit;
  }else{
    pSel->pLimit = sqlite3PExpr(pParse, TK_LIMIT, pLimit, 0);
  }
  pSel->iLimit = 0;
  if( sqlite3Select(pParse, pSel, &dest) ){
    return 0;
  }
  pExpr->iTable = rReg = dest.iSDParm;
  ExprSetVVAProperty(pExpr, EP_NoReduce);



  if( addrOnce ){

    sqlite3VdbeJumpHere(v, addrOnce);

    /* Subroutine return */

    sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
    sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
  }

  return rReg;
}
#endif /* SQLITE_OMIT_SUBQUERY */

#ifndef SQLITE_OMIT_SUBQUERY

  Expr *pLeft;          /* The LHS of the IN operator */
  int i;                /* loop counter */
  int destStep2;        /* Where to jump when NULLs seen in step 2 */
  int destStep6 = 0;    /* Start of code for Step 6 */
  int addrTruthOp;      /* Address of opcode that determines the IN is true */
  int destNotNull;      /* Jump here if a comparison is not true in step 6 */
  int addrTop;          /* Top of the step-6 loop */ 
  int iTab = 0;         /* Index to use */

  pLeft = pExpr->pLeft;
  if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
  zAff = exprINAffinity(pParse, pExpr);
  nVector = sqlite3ExprVectorSize(pExpr->pLeft);
  aiMap = (int*)sqlite3DbMallocZero(
      pParse->db, nVector*(sizeof(int) + sizeof(char)) + 1
  );
  if( pParse->db->mallocFailed ) goto sqlite3ExprCodeIN_oom_error;

  /* Attempt to compute the RHS. After this step, if anything other than
  ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
  ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
  ** the RHS has not yet been coded.  */
  v = pParse->pVdbe;
  assert( v!=0 );       /* OOM detected prior to this routine */
  VdbeNoopComment((v, "begin IN expr"));
  eType = sqlite3FindInIndex(pParse, pExpr,
                             IN_INDEX_MEMBERSHIP | IN_INDEX_NOOP_OK,
                             destIfFalse==destIfNull ? 0 : &rRhsHasNull,
                             aiMap, &iTab);

  assert( pParse->nErr || nVector==1 || eType==IN_INDEX_EPH
       || eType==IN_INDEX_INDEX_ASC || eType==IN_INDEX_INDEX_DESC 
  );
#ifdef SQLITE_DEBUG
  /* Confirm that aiMap[] contains nVector integer values between 0 and
  ** nVector-1. */

  ** sequence of comparisons.
  **
  ** This is step (1) in the in-operator.md optimized algorithm.
  */
  if( eType==IN_INDEX_NOOP ){
    ExprList *pList = pExpr->x.pList;
    CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
    int labelOk = sqlite3VdbeMakeLabel(pParse);
    int r2, regToFree;
    int regCkNull = 0;
    int ii;
    assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
    if( destIfNull!=destIfFalse ){
      regCkNull = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp3(v, OP_BitAnd, rLhs, rLhs, regCkNull);

  /* Step 2: Check to see if the LHS contains any NULL columns.  If the
  ** LHS does contain NULLs then the result must be either FALSE or NULL.
  ** We will then skip the binary search of the RHS.
  */
  if( destIfNull==destIfFalse ){
    destStep2 = destIfFalse;
  }else{
    destStep2 = destStep6 = sqlite3VdbeMakeLabel(pParse);
  }
  for(i=0; i<nVector; i++){
    Expr *p = sqlite3VectorFieldSubexpr(pExpr->pLeft, i);
    if( sqlite3ExprCanBeNull(p) ){
      sqlite3VdbeAddOp2(v, OP_IsNull, rLhs+i, destStep2);
      VdbeCoverage(v);
    }
  }

  /* Step 3.  The LHS is now known to be non-NULL.  Do the binary search
  ** of the RHS using the LHS as a probe.  If found, the result is
  ** true.
  */
  if( eType==IN_INDEX_ROWID ){
    /* In this case, the RHS is the ROWID of table b-tree and so we also
    ** know that the RHS is non-NULL.  Hence, we combine steps 3 and 4
    ** into a single opcode. */
    sqlite3VdbeAddOp3(v, OP_SeekRowid, iTab, destIfFalse, rLhs);
    VdbeCoverage(v);
    addrTruthOp = sqlite3VdbeAddOp0(v, OP_Goto);  /* Return True */
  }else{
    sqlite3VdbeAddOp4(v, OP_Affinity, rLhs, nVector, 0, zAff, nVector);
    if( destIfFalse==destIfNull ){
      /* Combine Step 3 and Step 5 into a single opcode */
      sqlite3VdbeAddOp4Int(v, OP_NotFound, iTab, destIfFalse,
                           rLhs, nVector); VdbeCoverage(v);
      goto sqlite3ExprCodeIN_finished;
    }
    /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
    addrTruthOp = sqlite3VdbeAddOp4Int(v, OP_Found, iTab, 0,
                                      rLhs, nVector); VdbeCoverage(v);
  }

  /* Step 4.  If the RHS is known to be non-NULL and we did not find
  ** an match on the search above, then the result must be FALSE.
  */
  if( rRhsHasNull && nVector==1 ){

  ** If any comparison is NULL, then the result is NULL.  If all
  ** comparisons are FALSE then the final result is FALSE.
  **
  ** For a scalar LHS, it is sufficient to check just the first row
  ** of the RHS.
  */
  if( destStep6 ) sqlite3VdbeResolveLabel(v, destStep6);
  addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, destIfFalse);
  VdbeCoverage(v);
  if( nVector>1 ){
    destNotNull = sqlite3VdbeMakeLabel(pParse);
  }else{
    /* For nVector==1, combine steps 6 and 7 by immediately returning
    ** FALSE if the first comparison is not NULL */
    destNotNull = destIfFalse;
  }
  for(i=0; i<nVector; i++){
    Expr *p;
    CollSeq *pColl;
    int r3 = sqlite3GetTempReg(pParse);
    p = sqlite3VectorFieldSubexpr(pLeft, i);
    pColl = sqlite3ExprCollSeq(pParse, p);
    sqlite3VdbeAddOp3(v, OP_Column, iTab, i, r3);
    sqlite3VdbeAddOp4(v, OP_Ne, rLhs+i, destNotNull, r3,
                      (void*)pColl, P4_COLLSEQ);
    VdbeCoverage(v);
    sqlite3ReleaseTempReg(pParse, r3);
  }
  sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfNull);
  if( nVector>1 ){
    sqlite3VdbeResolveLabel(v, destNotNull);
    sqlite3VdbeAddOp2(v, OP_Next, iTab, addrTop+1);
    VdbeCoverage(v);

    /* Step 7:  If we reach this point, we know that the result must
    ** be false. */
    sqlite3VdbeAddOp2(v, OP_Goto, 0, destIfFalse);
  }

    iResult = sqlite3ExprCodeTemp(pParse, p, piFreeable);
  }else{
    *piFreeable = 0;
    if( p->op==TK_SELECT ){
#if SQLITE_OMIT_SUBQUERY
      iResult = 0;
#else
      iResult = sqlite3CodeSubselect(pParse, p);
#endif
    }else{
      int i;
      iResult = pParse->nMem+1;
      pParse->nMem += nResult;
      for(i=0; i<nResult; i++){
        sqlite3ExprCodeFactorable(pParse, p->x.pList->a[i].pExpr, i+iResult);

      }

      /* Attempt a direct implementation of the built-in COALESCE() and
      ** IFNULL() functions.  This avoids unnecessary evaluation of
      ** arguments past the first non-NULL argument.
      */
      if( pDef->funcFlags & SQLITE_FUNC_COALESCE ){
        int endCoalesce = sqlite3VdbeMakeLabel(pParse);
        assert( nFarg>=2 );
        sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
        for(i=1; i<nFarg; i++){
          sqlite3VdbeAddOp2(v, OP_NotNull, target, endCoalesce);
          VdbeCoverage(v);
          sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
        }

    case TK_SELECT: {
      int nCol;
      testcase( op==TK_EXISTS );
      testcase( op==TK_SELECT );
      if( op==TK_SELECT && (nCol = pExpr->x.pSelect->pEList->nExpr)!=1 ){
        sqlite3SubselectError(pParse, nCol, 1);
      }else{
        return sqlite3CodeSubselect(pParse, pExpr);
      }
      break;
    }
    case TK_SELECT_COLUMN: {
      int n;
      if( pExpr->pLeft->iTable==0 ){
        pExpr->pLeft->iTable = sqlite3CodeSubselect(pParse, pExpr->pLeft);
      }
      assert( pExpr->iTable==0 || pExpr->pLeft->op==TK_SELECT );
      if( pExpr->iTable
       && pExpr->iTable!=(n = sqlite3ExprVectorSize(pExpr->pLeft)) 
      ){
        sqlite3ErrorMsg(pParse, "%d columns assigned %d values",
                                pExpr->iTable, n);
      }
      return pExpr->pLeft->iTable + pExpr->iColumn;
    }
    case TK_IN: {
      int destIfFalse = sqlite3VdbeMakeLabel(pParse);
      int destIfNull = sqlite3VdbeMakeLabel(pParse);
      sqlite3VdbeAddOp2(v, OP_Null, 0, target);
      sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
      sqlite3VdbeResolveLabel(v, destIfFalse);
      sqlite3VdbeAddOp2(v, OP_AddImm, target, 0);
      sqlite3VdbeResolveLabel(v, destIfNull);
      return target;

      Expr *pTest = 0;                  /* X==Ei (form A) or just Ei (form B) */

      assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
      assert(pExpr->x.pList->nExpr > 0);
      pEList = pExpr->x.pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(pParse);
      if( (pX = pExpr->pLeft)!=0 ){
        exprNodeCopy(&tempX, pX);
        testcase( pX->op==TK_COLUMN );
        exprToRegister(&tempX, exprCodeVector(pParse, &tempX, &regFree1));
        testcase( regFree1==0 );
        memset(&opCompare, 0, sizeof(opCompare));
        opCompare.op = TK_EQ;
        opCompare.pLeft = &tempX;
        pTest = &opCompare;
        /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
        ** The value in regFree1 might get SCopy-ed into the file result.
        ** So make sure that the regFree1 register is not reused for other
        ** purposes and possibly overwritten.  */
        regFree1 = 0;
      }
      for(i=0; i<nExpr-1; i=i+2){
        if( pX ){
          assert( pTest!=0 );
          opCompare.pRight = aListelem[i].pExpr;
        }else{
          pTest = aListelem[i].pExpr;
        }
        nextCase = sqlite3VdbeMakeLabel(pParse);
        testcase( pTest->op==TK_COLUMN );
        sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
        testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
        sqlite3VdbeGoto(v, endLabel);
        sqlite3VdbeResolveLabel(v, nextCase);
      }

){
 Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
  Expr compLeft;    /* The  x>=y  term */
  Expr compRight;   /* The  x<=z  term */
  Expr exprX;       /* The  x  subexpression */
  int regFree1 = 0; /* Temporary use register */


  memset(&compLeft, 0, sizeof(Expr));
  memset(&compRight, 0, sizeof(Expr));
  memset(&exprAnd, 0, sizeof(Expr));

  assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
  exprNodeCopy(&exprX, pExpr->pLeft);
  exprAnd.op = TK_AND;
  exprAnd.pLeft = &compLeft;
  exprAnd.pRight = &compRight;
  compLeft.op = TK_GE;
  compLeft.pLeft = &exprX;
  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
  compRight.op = TK_LE;

  assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
  if( NEVER(v==0) )     return;  /* Existence of VDBE checked by caller */
  if( NEVER(pExpr==0) ) return;  /* No way this can happen */
  op = pExpr->op;
  switch( op ){
    case TK_AND: {
      int d2 = sqlite3VdbeMakeLabel(pParse);
      testcase( jumpIfNull==0 );
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
      sqlite3VdbeResolveLabel(v, d2);
      break;
    }
    case TK_OR: {

    case TK_BETWEEN: {
      testcase( jumpIfNull==0 );
      exprCodeBetween(pParse, pExpr, dest, sqlite3ExprIfTrue, jumpIfNull);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_IN: {
      int destIfFalse = sqlite3VdbeMakeLabel(pParse);
      int destIfNull = jumpIfNull ? dest : destIfFalse;
      sqlite3ExprCodeIN(pParse, pExpr, destIfFalse, destIfNull);
      sqlite3VdbeGoto(v, dest);
      sqlite3VdbeResolveLabel(v, destIfFalse);
      break;
    }
#endif

    case TK_AND: {
      testcase( jumpIfNull==0 );
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
      break;
    }
    case TK_OR: {
      int d2 = sqlite3VdbeMakeLabel(pParse);
      testcase( jumpIfNull==0 );
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
      sqlite3VdbeResolveLabel(v, d2);
      break;
    }
    case TK_NOT: {

      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_IN: {
      if( jumpIfNull ){
        sqlite3ExprCodeIN(pParse, pExpr, dest, dest);
      }else{
        int destIfNull = sqlite3VdbeMakeLabel(pParse);
        sqlite3ExprCodeIN(pParse, pExpr, dest, destIfNull);
        sqlite3VdbeResolveLabel(v, destIfNull);
      }
      break;
    }
#endif
    default: {

  combinedFlags = pA->flags | pB->flags;
  if( combinedFlags & EP_IntValue ){
    if( (pA->flags&pB->flags&EP_IntValue)!=0 && pA->u.iValue==pB->u.iValue ){
      return 0;
    }
    return 2;
  }
  if( pA->op!=pB->op || pA->op==TK_RAISE ){
    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA->pLeft,pB,iTab)<2 ){
      return 1;
    }
    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pParse, pA,pB->pLeft,iTab)<2 ){
      return 1;
    }
    return 2;

      ** if we reach this point, either A and B both window functions or
      ** neither are a window functions. */
      assert( ExprHasProperty(pA,EP_WinFunc)==ExprHasProperty(pB,EP_WinFunc) );
      if( ExprHasProperty(pA,EP_WinFunc) ){
        if( sqlite3WindowCompare(pParse,pA->y.pWin,pB->y.pWin)!=0 ) return 2;
      }
#endif
    }else if( pA->op==TK_NULL ){
      return 0;
    }else if( pA->op==TK_COLLATE ){
      if( sqlite3_stricmp(pA->u.zToken,pB->u.zToken)!=0 ) return 2;
    }else if( ALWAYS(pB->u.zToken!=0) && strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return 2;
    }
  }
  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
  if( (combinedFlags & EP_TokenOnly)==0 ){
    if( combinedFlags & EP_xIsSelect ) return 2;
    if( (combinedFlags & EP_FixedCol)==0
     && sqlite3ExprCompare(pParse, pA->pLeft, pB->pLeft, iTab) ) return 2;
    if( sqlite3ExprCompare(pParse, pA->pRight, pB->pRight, iTab) ) return 2;
    if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;

    if( pA->op!=TK_STRING
     && pA->op!=TK_TRUEFALSE
     && (combinedFlags & EP_Reduced)==0
    ){
      if( pA->iColumn!=pB->iColumn ) return 2;
      if( pA->iTable!=pB->iTable 
       && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
    }
  }
  return 0;
}

  testcase( pExpr->op==TK_AGG_COLUMN );
  testcase( pExpr->op==TK_AGG_FUNCTION );
  if( ExprHasProperty(pExpr, EP_FromJoin) ) return WRC_Prune;
  switch( pExpr->op ){
    case TK_ISNOT:
    case TK_NOT:
    case TK_ISNULL:
    case TK_NOTNULL:
    case TK_IS:
    case TK_OR:
    case TK_CASE:
    case TK_IN:
    case TK_FUNCTION:
      testcase( pExpr->op==TK_ISNOT );
      testcase( pExpr->op==TK_NOT );
      testcase( pExpr->op==TK_ISNULL );
      testcase( pExpr->op==TK_NOTNULL );
      testcase( pExpr->op==TK_IS );
      testcase( pExpr->op==TK_OR );
      testcase( pExpr->op==TK_CASE );
      testcase( pExpr->op==TK_IN );
      testcase( pExpr->op==TK_FUNCTION );
      return WRC_Prune;
    case TK_COLUMN:

SQLITE_PRIVATE void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
  Walker w;
  w.xExprCallback = analyzeAggregate;
  w.xSelectCallback = analyzeAggregatesInSelect;
  w.xSelectCallback2 = analyzeAggregatesInSelectEnd;
  w.walkerDepth = 0;
  w.u.pNC = pNC;
  w.pParse = 0;
  assert( pNC->pSrcList!=0 );
  sqlite3WalkExpr(&w, pExpr);
}

/*
** Call sqlite3ExprAnalyzeAggregates() for every expression in an
** expression list.  Return the number of errors.

** Parameter zName is the name of a table that is about to be altered
** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).
** If the table is a system table, this function leaves an error message
** in pParse->zErr (system tables may not be altered) and returns non-zero.
**
** Or, if zName is not a system table, zero is returned.
*/
static int isAlterableTable(Parse *pParse, Table *pTab){
  if( 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) 
#ifndef SQLITE_OMIT_VIRTUALTABLE
   || ( (pTab->tabFlags & TF_Shadow) 
     && (pParse->db->flags & SQLITE_Defensive)
     && pParse->db->nVdbeExec==0
   )
#endif
  ){
    sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
    return 1;
  }
  return 0;
}

/*
** Generate code to verify that the schemas of database zDb and, if

        "there is already another table or index with this name: %s", zName);
    goto exit_rename_table;
  }

  /* Make sure it is not a system table being altered, or a reserved name
  ** that the table is being renamed to.
  */
  if( SQLITE_OK!=isAlterableTable(pParse, pTab) ){
    goto exit_rename_table;
  }
  if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto
    exit_rename_table;
  }

#ifndef SQLITE_OMIT_VIEW

#endif

  /* Make sure this is not an attempt to ALTER a view. */
  if( pTab->pSelect ){
    sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
    goto exit_begin_add_column;
  }
  if( SQLITE_OK!=isAlterableTable(pParse, pTab) ){
    goto exit_begin_add_column;
  }

  assert( pTab->addColOffset>0 );
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);

  /* Put a copy of the Table struct in Parse.pNewTable for the

  int bQuote;                     /* True to quote the new name */

  /* Locate the table to be altered */
  pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
  if( !pTab ) goto exit_rename_column;

  /* Cannot alter a system table */
  if( SQLITE_OK!=isAlterableTable(pParse, pTab) ) goto exit_rename_column;
  if( SQLITE_OK!=isRealTable(pParse, pTab) ) goto exit_rename_column;

  /* Which schema holds the table to be altered */  
  iSchema = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iSchema>=0 );
  zDb = db->aDb[iSchema].zDbSName;

      pToken->pNext = pCtx->pList;
      pCtx->pList = pToken;
      pCtx->nList++;
      break;
    }
  }
}

/*
** Iterate through the Select objects that are part of WITH clauses attached
** to select statement pSelect.
*/
static void renameWalkWith(Walker *pWalker, Select *pSelect){
  if( pSelect->pWith ){
    int i;
    for(i=0; i<pSelect->pWith->nCte; i++){
      Select *p = pSelect->pWith->a[i].pSelect;
      NameContext sNC;
      memset(&sNC, 0, sizeof(sNC));
      sNC.pParse = pWalker->pParse;
      sqlite3SelectPrep(sNC.pParse, p, &sNC);
      sqlite3WalkSelect(pWalker, p);
    }
  }
}

/*
** This is a Walker select callback. It does nothing. It is only required
** because without a dummy callback, sqlite3WalkExpr() and similar do not
** descend into sub-select statements.
*/
static int renameColumnSelectCb(Walker *pWalker, Select *p){
  renameWalkWith(pWalker, p);

  return WRC_Continue;
}

/*
** This is a Walker expression callback.
**
** For every TK_COLUMN node in the expression tree, search to see

  memset(p, 0, sizeof(Parse));
  p->eParseMode = (bTable ? PARSE_MODE_RENAME_TABLE : PARSE_MODE_RENAME_COLUMN);
  p->db = db;
  p->nQueryLoop = 1;
  rc = sqlite3RunParser(p, zSql, &zErr);
  assert( p->zErrMsg==0 );
  assert( rc!=SQLITE_OK || zErr==0 );

  p->zErrMsg = zErr;
  if( db->mallocFailed ) rc = SQLITE_NOMEM;
  if( rc==SQLITE_OK 
   && p->pNewTable==0 && p->pNewIndex==0 && p->pNewTrigger==0 
  ){
    rc = SQLITE_CORRUPT_BKPT;
  }

            rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertWhere);
          }
          if( rc==SQLITE_OK ){
            rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);
          }
          sNC.ncFlags = 0;
        }
        sNC.pSrcList = 0;
      }
    }
  }
  return rc;
}

/*

/*
** Free the contents of Parse object (*pParse). Do not free the memory
** occupied by the Parse object itself.
*/
static void renameParseCleanup(Parse *pParse){
  sqlite3 *db = pParse->db;
  Index *pIdx;
  if( pParse->pVdbe ){
    sqlite3VdbeFinalize(pParse->pVdbe);
  }
  sqlite3DeleteTable(db, pParse->pNewTable);
  while( (pIdx = pParse->pNewIndex)!=0 ){
    pParse->pNewIndex = pIdx->pNext;
    sqlite3FreeIndex(db, pIdx);
  }
  sqlite3DeleteTrigger(db, pParse->pNewTrigger);
  sqlite3DbFree(db, pParse->zErrMsg);
  renameTokenFree(db, pParse->pRename);
  sqlite3ParserReset(pParse);
}

/*

        if( sCtx.iCol<0 ){
          renameTokenFind(&sParse, &sCtx, (void*)&sParse.pNewTable->iPKey);
        }
        sqlite3WalkExprList(&sWalker, sParse.pNewTable->pCheck);
        for(pIdx=sParse.pNewTable->pIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3WalkExprList(&sWalker, pIdx->aColExpr);
        }
        for(pIdx=sParse.pNewIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3WalkExprList(&sWalker, pIdx->aColExpr);
        }
      }

      for(pFKey=sParse.pNewTable->pFKey; pFKey; pFKey=pFKey->pNextFrom){
        for(i=0; i<pFKey->nCol; i++){
          if( bFKOnly==0 && pFKey->aCol[i].iFrom==iCol ){
            renameTokenFind(&sParse, &sCtx, (void*)&pFKey->aCol[i]);
          }

/*
** Walker select callback used by "RENAME TABLE". 
*/
static int renameTableSelectCb(Walker *pWalker, Select *pSelect){
  int i;
  RenameCtx *p = pWalker->u.pRename;
  SrcList *pSrc = pSelect->pSrc;
  if( pSrc==0 ){
    assert( pWalker->pParse->db->mallocFailed );
    return WRC_Abort;
  }
  for(i=0; i<pSrc->nSrc; i++){
    struct SrcList_item *pItem = &pSrc->a[i];
    if( pItem->pTab==p->pTab ){
      renameTokenFind(pWalker->pParse, p, pItem->zName);
    }
  }
  renameWalkWith(pWalker, pSelect);

  return WRC_Continue;
}


/*
** This C function implements an SQL user function that is used by SQL code

    */
    addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur);
    VdbeCoverage(v);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng);
    addrNextRow = sqlite3VdbeCurrentAddr(v);

    if( nColTest>0 ){
      int endDistinctTest = sqlite3VdbeMakeLabel(pParse);
      int *aGotoChng;               /* Array of jump instruction addresses */
      aGotoChng = sqlite3DbMallocRawNN(db, sizeof(int)*nColTest);
      if( aGotoChng==0 ) continue;

      /*
      **  next_row:
      **   regChng = 0

      sqlite3_result_error(context, zErr, -1);
      sqlite3_free(zErr);
      return;
    }
    assert( pVfs );
    flags |= SQLITE_OPEN_MAIN_DB;
    rc = sqlite3BtreeOpen(pVfs, zPath, db, &pNew->pBt, 0, flags);

    db->nDb++;
    pNew->zDbSName = sqlite3DbStrDup(db, zName);
  }
  db->noSharedCache = 0;
  if( rc==SQLITE_CONSTRAINT ){
    rc = SQLITE_ERROR;
    zErrDyn = sqlite3MPrintf(db, "database is already attached");
  }else if( rc==SQLITE_OK ){
    Pager *pPager;

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    sqlite3BtreeSetPagerFlags(pNew->pBt,
                      PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
#endif
    sqlite3BtreeLeave(pNew->pBt);
  }
  pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;

  if( rc==SQLITE_OK && pNew->zDbSName==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }


#ifdef SQLITE_HAS_CODEC
  if( rc==SQLITE_OK ){

      case SQLITE_BLOB:
        nKey = sqlite3_value_bytes(argv[2]);
        zKey = (char *)sqlite3_value_blob(argv[2]);
        rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
        break;

      case SQLITE_NULL:
        /* No key specified.  Use the key from URI filename, or if none,
        ** use the key from the main database. */
        if( sqlite3CodecQueryParameters(db, zName, zPath)==0 ){
          sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
          if( nKey || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
            rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
          }
        }
        break;
    }
  }
#endif
  sqlite3_free( zPath );

  /* If the file was opened successfully, read the schema for the new database.
  ** If this fails, or if opening the file failed, then close the file and 
  ** remove the entry from the db->aDb[] array. i.e. put everything back the
  ** way we found it.
  */
  if( rc==SQLITE_OK ){

  /* Get the VDBE program ready for execution
  */
  if( v && pParse->nErr==0 && !db->mallocFailed ){
    /* A minimum of one cursor is required if autoincrement is used
    *  See ticket [a696379c1f08866] */
    assert( pParse->pAinc==0 || pParse->nTab>0 );
    sqlite3VdbeMakeReady(v, pParse);
    pParse->rc = SQLITE_DONE;
  }else{
    pParse->rc = SQLITE_ERROR;
  }
}

   && SQLITE_OK!=sqlite3ReadSchema(pParse)
  ){
    return 0;
  }

  p = sqlite3FindTable(db, zName, zDbase);
  if( p==0 ){

#ifndef SQLITE_OMIT_VIRTUALTABLE
    /* If zName is the not the name of a table in the schema created using
    ** CREATE, then check to see if it is the name of an virtual table that
    ** can be an eponymous virtual table. */
    if( pParse->disableVtab==0 ){
      Module *pMod = (Module*)sqlite3HashFind(&db->aModule, zName);
      if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){
        pMod = sqlite3PragmaVtabRegister(db, zName);
      }
      if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
        return pMod->pEpoTab;
      }
    }
#endif
    if( flags & LOCATE_NOERR ) return 0;
    pParse->checkSchema = 1;
  }else if( IsVirtual(p) && pParse->disableVtab ){
    p = 0;
  }

  if( p==0 ){
    const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";
    if( zDbase ){
      sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
    }else{
      sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);


    }
  }

  return p;
}

/*

  }

  /* Delete any foreign keys attached to this table. */
  sqlite3FkDelete(db, pTable);

  /* Delete the Table structure itself.
  */






  sqlite3DeleteColumnNames(db, pTable);
  sqlite3DbFree(db, pTable->zName);
  sqlite3DbFree(db, pTable->zColAff);
  sqlite3SelectDelete(db, pTable->pSelect);
  sqlite3ExprListDelete(db, pTable->pCheck);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3VtabClear(db, pTable);

  }

  /* Remove the table entry from SQLite's internal schema and modify
  ** the schema cookie.
  */
  if( IsVirtual(pTab) ){
    sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);
    sqlite3MayAbort(pParse);
  }
  sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
  sqlite3ChangeCookie(pParse, iDb);
  sqliteViewResetAll(db, iDb);
}

/*

                "conflicting ON CONFLICT clauses specified", 0);
          }
          if( pIdx->onError==OE_Default ){
            pIdx->onError = pIndex->onError;
          }
        }
        if( idxType==SQLITE_IDXTYPE_PRIMARYKEY ) pIdx->idxType = idxType;
        if( IN_RENAME_OBJECT ){
          pIndex->pNext = pParse->pNewIndex;
          pParse->pNewIndex = pIndex;
          pIndex = 0;
        }
        goto exit_create_index;
      }
    }
  }

  if( !IN_RENAME_OBJECT ){

    /* Link the new Index structure to its table and to the other
    ** in-memory database structures. 
    */
    assert( pParse->nErr==0 );
    if( db->init.busy ){
      Index *p;
      assert( !IN_SPECIAL_PARSE );
      assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
      if( pTblName!=0 ){
        pIndex->tnum = db->init.newTnum;
        if( sqlite3IndexHasDuplicateRootPage(pIndex) ){
          sqlite3ErrorMsg(pParse, "invalid rootpage");
          pParse->rc = SQLITE_CORRUPT_BKPT;
          goto exit_create_index;
        }
      }
      p = sqlite3HashInsert(&pIndex->pSchema->idxHash, 
          pIndex->zName, pIndex);
      if( p ){
        assert( p==pIndex );  /* Malloc must have failed */
        sqlite3OomFault(db);
        goto exit_create_index;
      }
      db->mDbFlags |= DBFLAG_SchemaChange;



    }

    /* If this is the initial CREATE INDEX statement (or CREATE TABLE if the
    ** index is an implied index for a UNIQUE or PRIMARY KEY constraint) then
    ** emit code to allocate the index rootpage on disk and make an entry for
    ** the index in the sqlite_master table and populate the index with
    ** content.  But, do not do this if we are simply reading the sqlite_master

  if( pList==0 ) return -1;
  for(i=0; i<pList->nId; i++){
    if( sqlite3StrICmp(pList->a[i].zName, zName)==0 ) return i;
  }
  return -1;
}

/*
** Maximum size of a SrcList object.
** The SrcList object is used to represent the FROM clause of a
** SELECT statement, and the query planner cannot deal with more
** than 64 tables in a join.  So any value larger than 64 here
** is sufficient for most uses.  Smaller values, like say 10, are
** appropriate for small and memory-limited applications.
*/
#ifndef SQLITE_MAX_SRCLIST
# define SQLITE_MAX_SRCLIST 200
#endif

/*
** Expand the space allocated for the given SrcList object by
** creating nExtra new slots beginning at iStart.  iStart is zero based.
** New slots are zeroed.
**
** For example, suppose a SrcList initially contains two entries: A,B.
** To append 3 new entries onto the end, do this:
**
**    sqlite3SrcListEnlarge(db, pSrclist, 3, 2);
**
** After the call above it would contain:  A, B, nil, nil, nil.
** If the iStart argument had been 1 instead of 2, then the result
** would have been:  A, nil, nil, nil, B.  To prepend the new slots,
** the iStart value would be 0.  The result then would
** be: nil, nil, nil, A, B.
**
** If a memory allocation fails or the SrcList becomes too large, leave
** the original SrcList unchanged, return NULL, and leave an error message
** in pParse.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(

  Parse *pParse,     /* Parsing context into which errors are reported */
  SrcList *pSrc,     /* The SrcList to be enlarged */
  int nExtra,        /* Number of new slots to add to pSrc->a[] */
  int iStart         /* Index in pSrc->a[] of first new slot */
){
  int i;

  /* Sanity checking on calling parameters */
  assert( iStart>=0 );
  assert( nExtra>=1 );
  assert( pSrc!=0 );
  assert( iStart<=pSrc->nSrc );

  /* Allocate additional space if needed */
  if( (u32)pSrc->nSrc+nExtra>pSrc->nAlloc ){
    SrcList *pNew;
    int nAlloc = pSrc->nSrc*2+nExtra;
    sqlite3 *db = pParse->db;

    if( pSrc->nSrc+nExtra>=SQLITE_MAX_SRCLIST ){
      sqlite3ErrorMsg(pParse, "too many FROM clause terms, max: %d",
                      SQLITE_MAX_SRCLIST);
      return 0;
    }
    if( nAlloc>SQLITE_MAX_SRCLIST ) nAlloc = SQLITE_MAX_SRCLIST;
    pNew = sqlite3DbRealloc(db, pSrc,
               sizeof(*pSrc) + (nAlloc-1)*sizeof(pSrc->a[0]) );
    if( pNew==0 ){
      assert( db->mallocFailed );
      return 0;
    }
    pSrc = pNew;

    pSrc->nAlloc = nAlloc;
  }

  /* Move existing slots that come after the newly inserted slots
  ** out of the way */
  for(i=pSrc->nSrc-1; i>=iStart; i--){
    pSrc->a[i+nExtra] = pSrc->a[i];
  }

}


/*
** Append a new table name to the given SrcList.  Create a new SrcList if
** need be.  A new entry is created in the SrcList even if pTable is NULL.
**
** A SrcList is returned, or NULL if there is an OOM error or if the
** SrcList grows to large.  The returned
** SrcList might be the same as the SrcList that was input or it might be
** a new one.  If an OOM error does occurs, then the prior value of pList
** that is input to this routine is automatically freed.
**
** If pDatabase is not null, it means that the table has an optional
** database name prefix.  Like this:  "database.table".  The pDatabase
** points to the table name and the pTable points to the database name.

**
**         sqlite3SrcListAppend(D,A,0,C);
**
** Both pTable and pDatabase are assumed to be quoted.  They are dequoted
** before being added to the SrcList.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(
  Parse *pParse,      /* Parsing context, in which errors are reported */
  SrcList *pList,     /* Append to this SrcList. NULL creates a new SrcList */
  Token *pTable,      /* Table to append */
  Token *pDatabase    /* Database of the table */
){
  struct SrcList_item *pItem;
  sqlite3 *db;
  assert( pDatabase==0 || pTable!=0 );  /* Cannot have C without B */
  assert( pParse!=0 );
  assert( pParse->db!=0 );
  db = pParse->db;
  if( pList==0 ){
    pList = sqlite3DbMallocRawNN(pParse->db, sizeof(SrcList) );
    if( pList==0 ) return 0;
    pList->nAlloc = 1;
    pList->nSrc = 1;
    memset(&pList->a[0], 0, sizeof(pList->a[0]));
    pList->a[0].iCursor = -1;
  }else{
    SrcList *pNew = sqlite3SrcListEnlarge(pParse, pList, 1, pList->nSrc);

    if( pNew==0 ){
      sqlite3SrcListDelete(db, pList);
      return 0;
    }else{
      pList = pNew;
    }
  }
  pItem = &pList->a[pList->nSrc-1];
  if( pDatabase && pDatabase->z==0 ){
    pDatabase = 0;
  }
  if( pDatabase ){
    pItem->zName = sqlite3NameFromToken(db, pDatabase);

  sqlite3 *db = pParse->db;
  if( !p && (pOn || pUsing) ){
    sqlite3ErrorMsg(pParse, "a JOIN clause is required before %s", 
      (pOn ? "ON" : "USING")
    );
    goto append_from_error;
  }
  p = sqlite3SrcListAppend(pParse, p, pTable, pDatabase);
  if( p==0 ){
    goto append_from_error;
  }
  assert( p->nSrc>0 );
  pItem = &p->a[p->nSrc-1];
  assert( (pTable==0)==(pDatabase==0) );
  assert( pItem->zName==0 || pDatabase!=0 );

/*
** Recompute all indices of pTab that use the collating sequence pColl.
** If pColl==0 then recompute all indices of pTab.
*/
#ifndef SQLITE_OMIT_REINDEX
static void reindexTable(Parse *pParse, Table *pTab, char const *zColl){
  if( !IsVirtual(pTab) ){
    Index *pIndex;              /* An index associated with pTab */

    for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
      if( zColl==0 || collationMatch(zColl, pIndex) ){
        int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
        sqlite3BeginWriteOperation(pParse, 0, iDb);
        sqlite3RefillIndex(pParse, pIndex, -1);
      }
    }
  }
}
#endif

/*
** Recompute all indices of all tables in all databases where the

  return match;
}

/*
** Search a FuncDefHash for a function with the given name.  Return
** a pointer to the matching FuncDef if found, or 0 if there is no match.
*/
SQLITE_PRIVATE FuncDef *sqlite3FunctionSearch(
  int h,               /* Hash of the name */
  const char *zFunc    /* Name of function */
){
  FuncDef *p;
  for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){
    if( sqlite3StrICmp(p->zName, zFunc)==0 ){
      return p;
    }
  }
  return 0;
}
















/*
** Insert a new FuncDef into a FuncDefHash hash table.
*/
SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(
  FuncDef *aDef,      /* List of global functions to be inserted */
  int nDef            /* Length of the apDef[] list */
){
  int i;
  for(i=0; i<nDef; i++){
    FuncDef *pOther;
    const char *zName = aDef[i].zName;
    int nName = sqlite3Strlen30(zName);
    int h = SQLITE_FUNC_HASH(zName[0], nName);
    assert( zName[0]>='a' && zName[0]<='z' );
    pOther = sqlite3FunctionSearch(h, zName);
    if( pOther ){
      assert( pOther!=&aDef[i] && pOther->pNext!=&aDef[i] );
      aDef[i].pNext = pOther->pNext;
      pOther->pNext = &aDef[i];
    }else{
      aDef[i].pNext = 0;
      aDef[i].u.pHash = sqlite3BuiltinFunctions.a[h];

  ** have fields overwritten with new information appropriate for the
  ** new function.  But the FuncDefs for built-in functions are read-only.
  ** So we must not search for built-ins when creating a new function.
  */ 
  if( !createFlag && (pBest==0 || (db->mDbFlags & DBFLAG_PreferBuiltin)!=0) ){
    bestScore = 0;
    h = SQLITE_FUNC_HASH(sqlite3UpperToLower[(u8)zName[0]], nName);
    p = sqlite3FunctionSearch(h, zName);
    while( p ){
      int score = matchQuality(p, nArg, enc);
      if( score>bestScore ){
        pBest = p;
        bestScore = score;
      }
      p = p->pNext;

){
  SelectDest dest;
  Select *pSel;
  SrcList *pFrom;
  sqlite3 *db = pParse->db;
  int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
  pWhere = sqlite3ExprDup(db, pWhere, 0);
  pFrom = sqlite3SrcListAppend(pParse, 0, 0, 0);
  if( pFrom ){
    assert( pFrom->nSrc==1 );
    pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
    pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
    assert( pFrom->a[0].pOn==0 );
    assert( pFrom->a[0].pUsing==0 );
  }

        sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
      }
    }
  
    /* If this DELETE cannot use the ONEPASS strategy, this is the 
    ** end of the WHERE loop */
    if( eOnePass!=ONEPASS_OFF ){
      addrBypass = sqlite3VdbeMakeLabel(pParse);
    }else{
      sqlite3WhereEnd(pWInfo);
    }
  
    /* Unless this is a view, open cursors for the table we are 
    ** deleting from and all its indices. If this is a view, then the
    ** only effect this statement has is to fire the INSTEAD OF 

  assert( v );
  VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",
                         iDataCur, iIdxCur, iPk, (int)nPk));

  /* Seek cursor iCur to the row to delete. If this row no longer exists 
  ** (this can happen if a trigger program has already deleted it), do
  ** not attempt to delete it or fire any DELETE triggers.  */
  iLabel = sqlite3VdbeMakeLabel(pParse);
  opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
  if( eMode==ONEPASS_OFF ){
    sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
    VdbeCoverageIf(v, opSeek==OP_NotExists);
    VdbeCoverageIf(v, opSeek==OP_NotFound);
  }
 

  Vdbe *v = pParse->pVdbe;
  int j;
  int regBase;
  int nCol;

  if( piPartIdxLabel ){
    if( pIdx->pPartIdxWhere ){
      *piPartIdxLabel = sqlite3VdbeMakeLabel(pParse);
      pParse->iSelfTab = iDataCur + 1;
      sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
                            SQLITE_JUMPIFNULL);
      pParse->iSelfTab = 0;
    }else{
      *piPartIdxLabel = 0;
    }

  const unsigned char *zHaystack;
  const unsigned char *zNeedle;
  int nHaystack;
  int nNeedle;
  int typeHaystack, typeNeedle;
  int N = 1;
  int isText;
  unsigned char firstChar;

  UNUSED_PARAMETER(argc);
  typeHaystack = sqlite3_value_type(argv[0]);
  typeNeedle = sqlite3_value_type(argv[1]);
  if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;
  nHaystack = sqlite3_value_bytes(argv[0]);
  nNeedle = sqlite3_value_bytes(argv[1]);
  if( nNeedle>0 ){
    if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
      zHaystack = sqlite3_value_blob(argv[0]);
      zNeedle = sqlite3_value_blob(argv[1]);
      isText = 0;
    }else{
      zHaystack = sqlite3_value_text(argv[0]);
      zNeedle = sqlite3_value_text(argv[1]);
      isText = 1;
    }
    if( zNeedle==0 || (nHaystack && zHaystack==0) ) return;
    firstChar = zNeedle[0];
    while( nNeedle<=nHaystack
       && (zHaystack[0]!=firstChar || memcmp(zHaystack, zNeedle, nNeedle)!=0)
    ){
      N++;
      do{
        nHaystack--;
        zHaystack++;
      }while( isText && (zHaystack[0]&0xc0)==0x80 );
    }
    if( nNeedle>nHaystack ) N = 0;

** that is N bytes long.
*/
static void randomBlob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_int64 n;
  unsigned char *p;
  assert( argc==1 );
  UNUSED_PARAMETER(argc);
  n = sqlite3_value_int64(argv[0]);
  if( n<1 ){
    n = 1;
  }
  p = contextMalloc(context, n);
  if( p ){
    sqlite3_randomness(n, p);
    sqlite3_result_blob(context, (char*)p, n, sqlite3_free);

  int regData,          /* Address of array containing child table row */
  int nIncr,            /* Increment constraint counter by this */
  int isIgnore          /* If true, pretend pTab contains all NULL values */
){
  int i;                                    /* Iterator variable */
  Vdbe *v = sqlite3GetVdbe(pParse);         /* Vdbe to add code to */
  int iCur = pParse->nTab - 1;              /* Cursor number to use */
  int iOk = sqlite3VdbeMakeLabel(pParse);   /* jump here if parent key found */

  sqlite3VdbeVerifyAbortable(v,
    (!pFKey->isDeferred
      && !(pParse->db->flags & SQLITE_DeferFKs)
      && !pParse->pToplevel 
      && !pParse->isMultiWrite) ? OE_Abort : OE_Ignore);

  ** to the WHERE clause that prevent this entry from being scanned.
  ** The added WHERE clause terms are like this:
  **
  **     $current_rowid!=rowid
  **     NOT( $current_a==a AND $current_b==b AND ... )
  **
  ** The first form is used for rowid tables.  The second form is used
  ** for WITHOUT ROWID tables. In the second form, the *parent* key is
  ** (a,b,...). Either the parent or primary key could be used to 
  ** uniquely identify the current row, but the parent key is more convenient
  ** as the required values have already been loaded into registers
  ** by the caller.
  */
  if( pTab==pFKey->pFrom && nIncr>0 ){
    Expr *pNe;                    /* Expression (pLeft != pRight) */
    Expr *pLeft;                  /* Value from parent table row */
    Expr *pRight;                 /* Column ref to child table */
    if( HasRowid(pTab) ){
      pLeft = exprTableRegister(pParse, pTab, regData, -1);
      pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, -1);
      pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight);
    }else{
      Expr *pEq, *pAll = 0;

      assert( pIdx!=0 );
      for(i=0; i<pIdx->nKeyCol; i++){
        i16 iCol = pIdx->aiColumn[i];
        assert( iCol>=0 );
        pLeft = exprTableRegister(pParse, pTab, regData, iCol);
        pRight = sqlite3Expr(db, TK_ID, pTab->aCol[iCol].zName);
        pEq = sqlite3PExpr(pParse, TK_IS, pLeft, pRight);
        pAll = sqlite3ExprAnd(db, pAll, pEq);
      }
      pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0);
    }
    pWhere = sqlite3ExprAnd(db, pWhere, pNe);
  }