Fossil

*/
static char *shell_strncpy(char *dest, const char *src, size_t n){
  size_t i;
  for(i=0; i<n-1 && src[i]!=0; i++) dest[i] = src[i];
  dest[i] = 0;
  return dest;
}

/*
** strcpy() workalike to squelch an unwarranted link-time warning
** from OpenBSD.
*/
static void shell_strcpy(char *dest, const char *src){
  while( (*(dest++) = *(src++))!=0 ){}
}

/*
** Optionally disable dynamic continuation prompt.
** Unless disabled, the continuation prompt shows open SQL lexemes if any,
** or open parentheses level if non-zero, or continuation prompt as set.
** This facility interacts with the scanner and process_input() where the
** below 5 macros are used.

      || (dynPrompt.zScannerAwaits==0 && dynPrompt.inParenLevel == 0) ){
    return continuePrompt;
  }else{
    if( dynPrompt.zScannerAwaits ){
      size_t ncp = strlen(continuePrompt);
      size_t ndp = strlen(dynPrompt.zScannerAwaits);
      if( ndp > ncp-3 ) return continuePrompt;
      shell_strcpy(dynPrompt.dynamicPrompt, dynPrompt.zScannerAwaits);
      while( ndp<3 ) dynPrompt.dynamicPrompt[ndp++] = ' ';
      shell_strncpy(dynPrompt.dynamicPrompt+3, continuePrompt+3,
              PROMPT_LEN_MAX-4);
    }else{
      if( dynPrompt.inParenLevel>9 ){
        shell_strncpy(dynPrompt.dynamicPrompt, "(..", 4);
      }else if( dynPrompt.inParenLevel<0 ){

** start, stop, and step columns, and if present, it uses those constraints
** to bound the sequence of generated values.  If the equality constraints
** are missing, it uses 0 for start, 4294967295 for stop, and 1 for step.
** xBestIndex returns a small cost when both start and stop are available,
** and a very large cost if either start or stop are unavailable.  This
** encourages the query planner to order joins such that the bounds of the
** series are well-defined.
**
** Update on 2024-08-22:
** xBestIndex now also looks for equality and inequality constraints against
** the value column and uses those constraints as additional bounds against
** the sequence range.  Thus, a query like this:
**
**     SELECT value FROM generate_series($SA,$EA)
**      WHERE value BETWEEN $SB AND $EB;
**
** Is logically the same as:
**
**     SELECT value FROM generate_series(max($SA,$SB),min($EA,$EB));
**
** Constraints on the value column can server as substitutes for constraints
** on the hidden start and stop columns.  So, the following two queries
** are equivalent:
**
**     SELECT value FROM generate_series($S,$E);
**     SELECT value FROM generate_series WHERE value BETWEEN $S and $E;
**
*/
/* #include "sqlite3ext.h" */
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>
#include <limits.h>

  }
  return smBase + ((sqlite3_int64)ix)*smStep;
}

/* typedef unsigned char u8; */

typedef struct SequenceSpec {
  sqlite3_int64 iOBase;        /* Original starting value ("start") */
  sqlite3_int64 iOTerm;        /* Original terminal value ("stop") */
  sqlite3_int64 iBase;         /* Starting value to actually use */
  sqlite3_int64 iTerm;         /* Terminal value to actually use */
  sqlite3_int64 iStep;         /* Increment ("step") */
  sqlite3_uint64 uSeqIndexMax; /* maximum sequence index (aka "n") */
  sqlite3_uint64 uSeqIndexNow; /* Current index during generation */
  sqlite3_int64 iValueNow;     /* Current value during generation */
  u8 isNotEOF;                 /* Sequence generation not exhausted */
  u8 isReversing;              /* Sequence is being reverse generated */
} SequenceSpec;

  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  series_cursor *pCur = (series_cursor*)cur;
  sqlite3_int64 x = 0;
  switch( i ){
    case SERIES_COLUMN_START:  x = pCur->ss.iOBase;     break;
    case SERIES_COLUMN_STOP:   x = pCur->ss.iOTerm;     break;
    case SERIES_COLUMN_STEP:   x = pCur->ss.iStep;      break;
    default:                   x = pCur->ss.iValueNow;  break;
  }
  sqlite3_result_int64(ctx, x);
  return SQLITE_OK;
}

#ifndef LARGEST_UINT64
#define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
#define LARGEST_UINT64 (0xffffffff|(((sqlite3_uint64)0xffffffff)<<32))
#define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
** Return the rowid for the current row, logically equivalent to n+1 where
** "n" is the ascending integer in the aforesaid production definition.
*/
static int seriesRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){

** once prior to any call to seriesColumn() or seriesRowid() or
** seriesEof().
**
** The query plan selected by seriesBestIndex is passed in the idxNum
** parameter.  (idxStr is not used in this implementation.)  idxNum
** is a bitmask showing which constraints are available:
**
**   0x0001:    start=VALUE
**   0x0002:    stop=VALUE
**   0x0004:    step=VALUE
**   0x0008:    descending order
**   0x0010:    ascending order
**   0x0020:    LIMIT  VALUE
**   0x0040:    OFFSET  VALUE
**   0x0080:    value=VALUE
**   0x0100:    value>=VALUE
**   0x0200:    value>VALUE
**   0x1000:    value<=VALUE
**   0x2000:    value<VALUE
**
** This routine should initialize the cursor and position it so that it
** is pointing at the first row, or pointing off the end of the table
** (so that seriesEof() will return true) if the table is empty.
*/
static int seriesFilter(
  sqlite3_vtab_cursor *pVtabCursor,
  int idxNum, const char *idxStrUnused,
  int argc, sqlite3_value **argv
){
  series_cursor *pCur = (series_cursor *)pVtabCursor;
  int i = 0;
  int returnNoRows = 0;
  sqlite3_int64 iMin = SMALLEST_INT64;
  sqlite3_int64 iMax = LARGEST_INT64;
  sqlite3_int64 iLimit = 0;
  sqlite3_int64 iOffset = 0;

  (void)idxStrUnused;
  if( idxNum & 0x01 ){
    pCur->ss.iBase = sqlite3_value_int64(argv[i++]);
  }else{
    pCur->ss.iBase = 0;
  }
  if( idxNum & 0x02 ){

      pCur->ss.iStep = 1;
    }else if( pCur->ss.iStep<0 ){
      if( (idxNum & 0x10)==0 ) idxNum |= 0x08;
    }
  }else{
    pCur->ss.iStep = 1;
  }

  /* If there are constraints on the value column but there are
  ** no constraints on  the start, stop, and step columns, then
  ** initialize the default range to be the entire range of 64-bit signed
  ** integers.  This range will contracted by the value column constraints
  ** further below.
  */
  if( (idxNum & 0x05)==0 && (idxNum & 0x0380)!=0 ){
    pCur->ss.iBase = SMALLEST_INT64;
  }
  if( (idxNum & 0x06)==0 && (idxNum & 0x3080)!=0 ){
    pCur->ss.iTerm = LARGEST_INT64;
  }
  pCur->ss.iOBase = pCur->ss.iBase;
  pCur->ss.iOTerm = pCur->ss.iTerm;

  /* Extract the LIMIT and OFFSET values, but do not apply them yet.
  ** The range must first be constrained by the limits on value.
  */
  if( idxNum & 0x20 ){
    iLimit = sqlite3_value_int64(argv[i++]);
    if( idxNum & 0x40 ){
      iOffset = sqlite3_value_int64(argv[i++]);
    }
  }

  if( idxNum & 0x3380 ){
    /* Extract the maximum range of output values determined by
    ** constraints on the "value" column.
    */
    if( idxNum & 0x0080 ){
      iMin = iMax = sqlite3_value_int64(argv[i++]);
    }else{
      if( idxNum & 0x0300 ){
        iMin = sqlite3_value_int64(argv[i++]);
        if( idxNum & 0x0200 ){
          if( iMin==LARGEST_INT64 ){
            returnNoRows = 1;
          }else{
            iMin++;
          }
        }
      }
      if( idxNum & 0x3000 ){
        iMax = sqlite3_value_int64(argv[i++]);
        if( idxNum & 0x2000 ){
          if( iMax==SMALLEST_INT64 ){
            returnNoRows = 1;
          }else{
            iMax--;
          }
        }
      }
      if( iMin>iMax ){
        returnNoRows = 1;
      }
    }

    /* Try to reduce the range of values to be generated based on
    ** constraints on the "value" column.
    */
    if( pCur->ss.iStep>0 ){
      sqlite3_int64 szStep = pCur->ss.iStep;
      if( pCur->ss.iBase<iMin ){
        sqlite3_uint64 d = iMin - pCur->ss.iBase;
        pCur->ss.iBase += ((d+szStep-1)/szStep)*szStep;
      }
      if( pCur->ss.iTerm>iMax ){
        sqlite3_uint64 d = pCur->ss.iTerm - iMax;
        pCur->ss.iTerm -= ((d+szStep-1)/szStep)*szStep;
      }
    }else{
      sqlite3_int64 szStep = -pCur->ss.iStep;
      assert( szStep>0 );
      if( pCur->ss.iBase>iMax ){
        sqlite3_uint64 d = pCur->ss.iBase - iMax;
        pCur->ss.iBase -= ((d+szStep-1)/szStep)*szStep;
      }
      if( pCur->ss.iTerm<iMin ){
        sqlite3_uint64 d = iMin - pCur->ss.iTerm;
        pCur->ss.iTerm += ((d+szStep-1)/szStep)*szStep;
      }
    }
  }

  /* Apply LIMIT and OFFSET constraints, if any */
  if( idxNum & 0x20 ){
    if( iOffset>0 ){
      pCur->ss.iBase += pCur->ss.iStep*iOffset;
    }

    if( iLimit>=0 ){
      sqlite3_int64 iTerm;
      iTerm = pCur->ss.iBase + (iLimit - 1)*pCur->ss.iStep;
      if( pCur->ss.iStep<0 ){
        if( iTerm>pCur->ss.iTerm ) pCur->ss.iTerm = iTerm;
      }else{
        if( iTerm<pCur->ss.iTerm ) pCur->ss.iTerm = iTerm;
      }
    }
  }


  for(i=0; i<argc; i++){
    if( sqlite3_value_type(argv[i])==SQLITE_NULL ){
      /* If any of the constraints have a NULL value, then return no rows.
      ** See ticket https://www.sqlite.org/src/info/fac496b61722daf2 */
      returnNoRows = 1;


      break;
    }
  }
  if( returnNoRows ){
    pCur->ss.iBase = 1;
    pCur->ss.iTerm = 0;
    pCur->ss.iStep = 1;
  }
  if( idxNum & 0x08 ){
    pCur->ss.isReversing = pCur->ss.iStep > 0;
  }else{
    pCur->ss.isReversing = pCur->ss.iStep < 0;
  }
  setupSequence( &pCur->ss );
  return SQLITE_OK;
}

/*
** SQLite will invoke this method one or more times while planning a query
** that uses the generate_series virtual table.  This routine needs to create
** a query plan for each invocation and compute an estimated cost for that
** plan.
**
** In this implementation idxNum is used to represent the
** query plan.  idxStr is unused.
**
** The query plan is represented by bits in idxNum:
**
**   0x0001  start = $num
**   0x0002  stop = $num
**   0x0004  step = $num
**   0x0008  output is in descending order
**   0x0010  output is in ascending order
**   0x0020  LIMIT $num
**   0x0040  OFFSET $num
**   0x0080  value = $num
**   0x0100  value >= $num
**   0x0200  value > $num
**   0x1000  value <= $num
**   0x2000  value < $num
**
** Only one of 0x0100 or 0x0200 will be returned.  Similarly, only
** one of 0x1000 or 0x2000 will be returned.  If the 0x0080 is set, then
** none of the 0xff00 bits will be set.
**
** The order of parameters passed to xFilter is as follows:
**
**    * The argument to start= if bit 0x0001 is in the idxNum mask
**    * The argument to stop= if bit 0x0002 is in the idxNum mask
**    * The argument to step= if bit 0x0004 is in the idxNum mask
**    * The argument to LIMIT if bit 0x0020 is in the idxNum mask
**    * The argument to OFFSET if bit 0x0040 is in the idxNum mask
**    * The argument to value=, or value>= or value> if any of
**      bits 0x0380 are in the idxNum mask
**    * The argument to value<= or value< if either of bits 0x3000
**      are in the mask
**
*/
static int seriesBestIndex(
  sqlite3_vtab *pVTab,
  sqlite3_index_info *pIdxInfo
){
  int i, j;              /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
  int bStartSeen = 0;    /* EQ constraint seen on the START column */
#endif
  int unusableMask = 0;  /* Mask of unusable constraints */
  int nArg = 0;          /* Number of arguments that seriesFilter() expects */
  int aIdx[7];           /* Constraints on start, stop, step, LIMIT, OFFSET,
                         ** and value.  aIdx[5] covers value=, value>=, and
                         ** value>,  aIdx[6] covers value<= and value< */
  const struct sqlite3_index_constraint *pConstraint;

  /* This implementation assumes that the start, stop, and step columns
  ** are the last three columns in the virtual table. */
  assert( SERIES_COLUMN_STOP == SERIES_COLUMN_START+1 );
  assert( SERIES_COLUMN_STEP == SERIES_COLUMN_START+2 );

  aIdx[0] = aIdx[1] = aIdx[2] = aIdx[3] = aIdx[4] = aIdx[5] = aIdx[6] = -1;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    int iCol;    /* 0 for start, 1 for stop, 2 for step */
    int iMask;   /* bitmask for those column */
    int op = pConstraint->op;
    if( op>=SQLITE_INDEX_CONSTRAINT_LIMIT
     && op<=SQLITE_INDEX_CONSTRAINT_OFFSET
    ){
      if( pConstraint->usable==0 ){
        /* do nothing */
      }else if( op==SQLITE_INDEX_CONSTRAINT_LIMIT ){
        aIdx[3] = i;
        idxNum |= 0x20;
      }else{
        assert( op==SQLITE_INDEX_CONSTRAINT_OFFSET );
        aIdx[4] = i;
        idxNum |= 0x40;
      }
      continue;
    }
    if( pConstraint->iColumn==SERIES_COLUMN_VALUE ){
      switch( op ){
        case SQLITE_INDEX_CONSTRAINT_EQ:
        case SQLITE_INDEX_CONSTRAINT_IS: {
          idxNum |=  0x0080;
          idxNum &= ~0x3300;
          aIdx[5] = i;
          aIdx[6] = -1;
          bStartSeen = 1;
          break;
        }
        case SQLITE_INDEX_CONSTRAINT_GE: {
          if( idxNum & 0x0080 ) break;
          idxNum |=  0x0100;
          idxNum &= ~0x0200;
          aIdx[5] = i;
          bStartSeen = 1;
          break;
        }
        case SQLITE_INDEX_CONSTRAINT_GT: {
          if( idxNum & 0x0080 ) break;
          idxNum |=  0x0200;
          idxNum &= ~0x0100;
          aIdx[5] = i;
          bStartSeen = 1;
          break;
        }
        case SQLITE_INDEX_CONSTRAINT_LE: {
          if( idxNum & 0x0080 ) break;
          idxNum |=  0x1000;
          idxNum &= ~0x2000;
          aIdx[6] = i;
          break;
        }
        case SQLITE_INDEX_CONSTRAINT_LT: {
          if( idxNum & 0x0080 ) break;
          idxNum |=  0x2000;
          idxNum &= ~0x1000;
          aIdx[6] = i;
          break;
        }
      }
      continue;
    }
    iCol = pConstraint->iColumn - SERIES_COLUMN_START;
    assert( iCol>=0 && iCol<=2 );
    iMask = 1 << iCol;
#ifndef ZERO_ARGUMENT_GENERATE_SERIES
    if( iCol==0 && op==SQLITE_INDEX_CONSTRAINT_EQ ){
      bStartSeen = 1;
    }

    }
  }
  if( aIdx[3]==0 ){
    /* Ignore OFFSET if LIMIT is omitted */
    idxNum &= ~0x60;
    aIdx[4] = 0;
  }
  for(i=0; i<7; i++){
    if( (j = aIdx[i])>=0 ){
      pIdxInfo->aConstraintUsage[j].argvIndex = ++nArg;
      pIdxInfo->aConstraintUsage[j].omit =
         !SQLITE_SERIES_CONSTRAINT_VERIFY || i>=3;
    }
  }
  /* The current generate_column() implementation requires at least one

  }else{
    /* If either boundary is missing, we have to generate a huge span
    ** of numbers.  Make this case very expensive so that the query
    ** planner will work hard to avoid it. */
    pIdxInfo->estimatedRows = 2147483647;
  }
  pIdxInfo->idxNum = idxNum;
#ifdef SQLITE_INDEX_SCAN_HEX
  pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_HEX;
#endif
  return SQLITE_OK;
}

/*
** This following structure defines all the methods for the 
** generate_series virtual table.
*/

  sqlite3_free(zSchemaTab);
  sqlite3_file_control(p->db, zDb, SQLITE_FCNTL_DATA_VERSION, &iDataVersion);
  oputf("%-20s %u\n", "data version", iDataVersion);
  return 0;
}
#endif /* SQLITE_SHELL_HAVE_RECOVER */

/*
** Print the given string as an error message.
*/
static void shellEmitError(const char *zErr){
  eputf("Error: %s\n", zErr);
}
/*
** Print the current sqlite3_errmsg() value to stderr and return 1.
*/
static int shellDatabaseError(sqlite3 *db){
  shellEmitError(sqlite3_errmsg(db));

  return 1;
}

/*
** Compare the pattern in zGlob[] against the text in z[].  Return TRUE
** if they match and FALSE (0) if they do not match.
**

*/
static int arErrorMsg(ArCommand *pAr, const char *zFmt, ...){
  va_list ap;
  char *z;
  va_start(ap, zFmt);
  z = sqlite3_vmprintf(zFmt, ap);
  va_end(ap);
  shellEmitError(z);
  if( pAr->fromCmdLine ){
    eputz("Use \"-A\" for more help\n");
  }else{
    eputz("Use \".archive --help\" for more help\n");
  }
  sqlite3_free(z);
  return SQLITE_ERROR;

    if( bAsync ){
      sqlite3_exec(pDest, "PRAGMA synchronous=OFF; PRAGMA journal_mode=OFF;",
                   0, 0, 0);
    }
    open_db(p, 0);
    pBackup = sqlite3_backup_init(pDest, "main", p->db, zDb);
    if( pBackup==0 ){
      shellDatabaseError(pDest);
      close_db(pDest);
      return 1;
    }
    while(  (rc = sqlite3_backup_step(pBackup,100))==SQLITE_OK ){}
    sqlite3_backup_finish(pBackup);
    if( rc==SQLITE_DONE ){
      rc = 0;
    }else{
      shellDatabaseError(pDest);
      rc = 1;
    }
    close_db(pDest);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='b' && n>=3 && cli_strncmp(azArg[0], "bail", n)==0 ){

    char **azName = 0;
    int nName = 0;
    sqlite3_stmt *pStmt;
    int i;
    open_db(p, 0);
    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
    if( rc ){
      shellDatabaseError(p->db);
      rc = 1;
    }else{
      while( sqlite3_step(pStmt)==SQLITE_ROW ){
        const char *zSchema = (const char *)sqlite3_column_text(pStmt,1);
        const char *zFile = (const char*)sqlite3_column_text(pStmt,2);
        if( zSchema==0 || zFile==0 ) continue;
        azName = sqlite3_realloc(azName, (nName+1)*2*sizeof(char*));

      shell_out_of_memory();
    }
    rc =  sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    zSql = 0;
    if( rc ){
      if (pStmt) sqlite3_finalize(pStmt);
      shellDatabaseError(p->db);
      import_cleanup(&sCtx);
      rc = 1;
      goto meta_command_exit;
    }
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      nCol = sqlite3_column_int(pStmt, 0);
    }else{

    if( eVerbose>=2 ){
      oputf("Insert using: %s\n", zSql);
    }
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    sqlite3_free(zSql);
    zSql = 0;
    if( rc ){
      shellDatabaseError(p->db);
      if (pStmt) sqlite3_finalize(pStmt);
      import_cleanup(&sCtx);
      rc = 1;
      goto meta_command_exit;
    }
    needCommit = sqlite3_get_autocommit(p->db);
    if( needCommit ) sqlite3_exec(p->db, "BEGIN", 0, 0, 0);

      goto meta_command_exit;
    }
    zFile = azArg[1];
    zProc = nArg>=3 ? azArg[2] : 0;
    open_db(p, 0);
    rc = sqlite3_load_extension(p->db, zFile, zProc, &zErrMsg);
    if( rc!=SQLITE_OK ){
      shellEmitError(zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }
  }else
#endif

  if( c=='l' && cli_strncmp(azArg[0], "log", n)==0 ){

      eputf("Error: cannot open \"%s\"\n", zSrcFile);
      close_db(pSrc);
      return 1;
    }
    open_db(p, 0);
    pBackup = sqlite3_backup_init(p->db, zDb, pSrc, "main");
    if( pBackup==0 ){
      shellDatabaseError(p->db);
      close_db(pSrc);
      return 1;
    }
    while( (rc = sqlite3_backup_step(pBackup,100))==SQLITE_OK
          || rc==SQLITE_BUSY  ){
      if( rc==SQLITE_BUSY ){
        if( nTimeout++ >= 3 ) break;
        sqlite3_sleep(100);
      }
    }
    sqlite3_backup_finish(pBackup);
    if( rc==SQLITE_DONE ){
      rc = 0;
    }else if( rc==SQLITE_BUSY || rc==SQLITE_LOCKED ){
      eputz("Error: source database is busy\n");
      rc = 1;
    }else{
      shellDatabaseError(p->db);
      rc = 1;
    }
    close_db(pSrc);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='s' && cli_strncmp(azArg[0], "scanstats", n)==0 ){

      }
    }
    if( zDiv ){
      sqlite3_stmt *pStmt = 0;
      rc = sqlite3_prepare_v2(p->db, "SELECT name FROM pragma_database_list",
                              -1, &pStmt, 0);
      if( rc ){
        shellDatabaseError(p->db);
        sqlite3_finalize(pStmt);
        rc = 1;
        goto meta_command_exit;
      }
      appendText(&sSelect, "SELECT sql FROM", 0);
      iSchema = 0;
      while( sqlite3_step(pStmt)==SQLITE_ROW ){

        oputf("SQL: %s;\n", sSelect.z);
      }else{
        rc = sqlite3_exec(p->db, sSelect.z, callback, &data, &zErrMsg);
      }
      freeText(&sSelect);
    }
    if( zErrMsg ){
      shellEmitError(zErrMsg);
      sqlite3_free(zErrMsg);
      rc = 1;
    }else if( rc != SQLITE_OK ){
      eputz("Error: querying schema information\n");
      rc = 1;
    }else{
      rc = 0;

    {"fault_install",      SQLITE_TESTCTRL_FAULT_INSTALL, 1,"args..."       },
    {"fk_no_action",       SQLITE_TESTCTRL_FK_NO_ACTION, 0, "BOOLEAN"       },
    {"imposter",         SQLITE_TESTCTRL_IMPOSTER,1,"SCHEMA ON/OFF ROOTPAGE"},
    {"internal_functions", SQLITE_TESTCTRL_INTERNAL_FUNCTIONS,0,""          },
    {"json_selfcheck",     SQLITE_TESTCTRL_JSON_SELFCHECK ,0,"BOOLEAN"      },
    {"localtime_fault",    SQLITE_TESTCTRL_LOCALTIME_FAULT,0,"BOOLEAN"      },
    {"never_corrupt",      SQLITE_TESTCTRL_NEVER_CORRUPT,1, "BOOLEAN"       },
    {"optimizations",      SQLITE_TESTCTRL_OPTIMIZATIONS,0,"DISABLE-MASK ..."},
#ifdef YYCOVERAGE
    {"parser_coverage",    SQLITE_TESTCTRL_PARSER_COVERAGE,0,""             },
#endif
    {"pending_byte",       SQLITE_TESTCTRL_PENDING_BYTE,1, "OFFSET  "       },
    {"prng_restore",       SQLITE_TESTCTRL_PRNG_RESTORE,0, ""               },
    {"prng_save",          SQLITE_TESTCTRL_PRNG_SAVE,   0, ""               },
    {"prng_seed",          SQLITE_TESTCTRL_PRNG_SEED,   0, "SEED ?db?"      },

      }
    }
    if( testctrl<0 ){
      eputf("Error: unknown test-control: %s\n"
            "Use \".testctrl --help\" for help\n", zCmd);
    }else{
      switch(testctrl){

        /* Special processing for .testctrl opt MASK ...
        ** Each MASK argument can be one of:
        **
        **      +LABEL       Enable the named optimization 
        **
        **      -LABEL       Disable the named optimization
        **
        **      INTEGER      Mask of optimizations to disable
        */
        case SQLITE_TESTCTRL_OPTIMIZATIONS: {
          static const struct {
             unsigned int mask;    /* Mask for this optimization */
             unsigned int bDsply;  /* Display this on output */
             const char *zLabel;   /* Name of optimization */
          } aLabel[] = {
            { 0x00000001, 1, "QueryFlattener" },
            { 0x00000001, 0, "Flatten" },
            { 0x00000002, 1, "WindowFunc" },
            { 0x00000004, 1, "GroupByOrder" },
            { 0x00000008, 1, "FactorOutConst" },
            { 0x00000010, 1, "DistinctOpt" },
            { 0x00000020, 1, "CoverIdxScan" },
            { 0x00000040, 1, "OrderByIdxJoin" },
            { 0x00000080, 1, "Transitive" },
            { 0x00000100, 1, "OmitNoopJoin" },
            { 0x00000200, 1, "CountOfView" },
            { 0x00000400, 1, "CurosrHints" },
            { 0x00000800, 1, "Stat4" },
            { 0x00001000, 1, "PushDown" },
            { 0x00002000, 1, "SimplifyJoin" },
            { 0x00004000, 1, "SkipScan" },
            { 0x00008000, 1, "PropagateConst" },
            { 0x00010000, 1, "MinMaxOpt" },
            { 0x00020000, 1, "SeekScan" },
            { 0x00040000, 1, "OmitOrderBy" },
            { 0x00080000, 1, "BloomFilter" },
            { 0x00100000, 1, "BloomPulldown" },
            { 0x00200000, 1, "BalancedMerge" },
            { 0x00400000, 1, "ReleaseReg" },
            { 0x00800000, 1, "FlttnUnionAll" },
            { 0x01000000, 1, "IndexedEXpr" },
            { 0x02000000, 1, "Coroutines" },
            { 0x04000000, 1, "NullUnusedCols" },
            { 0x08000000, 1, "OnePass" },
            { 0x10000000, 1, "OrderBySubq" },
            { 0xffffffff, 0, "All" },
          };
          unsigned int curOpt;
          unsigned int newOpt;
          int ii;
          sqlite3_test_control(SQLITE_TESTCTRL_GETOPT, p->db, &curOpt);
          newOpt = curOpt;
          for(ii=2; ii<nArg; ii++){
            const char *z = azArg[ii];
            int useLabel = 0;
            const char *zLabel;
            if( (z[0]=='+'|| z[0]=='-') && !IsDigit(z[1]) ){
              useLabel = z[0];
              zLabel = &z[1];
            }else if( !IsDigit(z[0]) && z[0]!=0 && !IsDigit(z[1]) ){
              useLabel = '+';
              zLabel = z;
            }else{
              newOpt = (unsigned int)strtol(z,0,0);
            }
            if( useLabel ){
              int jj;
              for(jj=0; jj<ArraySize(aLabel); jj++){
                if( sqlite3_stricmp(zLabel, aLabel[jj].zLabel)==0 ) break;
              }
              if( jj>=ArraySize(aLabel) ){
                eputf("Error: no such optimization: \"%s\"\n", zLabel);
                eputf("Should be one of:");
                for(jj=0; jj<ArraySize(aLabel); jj++){
                  eputf(" %s", aLabel[jj].zLabel);
                }
                eputf("\n");
                rc = 1;
                goto meta_command_exit;
              }
              if( useLabel=='+' ){
                newOpt &= ~aLabel[jj].mask;
              }else{
                newOpt |= aLabel[jj].mask;
              }
            }
          }
          if( curOpt!=newOpt ){
            sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,p->db,newOpt);
          }else if( nArg<3 ){
            curOpt = ~newOpt;
          }
          if( newOpt==0 ){
            oputf("+All\n");
          }else if( newOpt==0xffffffff ){
            oputf("-All\n");
          }else{
            int jj;
            for(jj=0; jj<ArraySize(aLabel); jj++){
              unsigned int m = aLabel[jj].mask;
              if( !aLabel[jj].bDsply  ) continue;
              if( (curOpt&m)!=(newOpt&m) ){
                oputf("%c%s\n", (newOpt & m)==0 ? '+' : '-',
                      aLabel[jj].zLabel);
              }
            }
          }
          rc2 = isOk = 3;
          break;
        }

        /* sqlite3_test_control(int, db, int) */
        case SQLITE_TESTCTRL_FK_NO_ACTION:
          if( nArg==3 ){
            unsigned int opt = (unsigned int)strtol(azArg[2], 0, 0);
            rc2 = sqlite3_test_control(testctrl, p->db, opt);
            isOk = 3;
          }
          break;

      if( z[0]=='.' ){
        rc = do_meta_command(z, &data);
        if( rc && bail_on_error ) return rc==2 ? 0 : rc;
      }else{
        open_db(&data, 0);
        rc = shell_exec(&data, z, &zErrMsg);
        if( zErrMsg!=0 ){
          shellEmitError(zErrMsg);
          if( bail_on_error ) return rc!=0 ? rc : 1;
        }else if( rc!=0 ){
          eputf("Error: unable to process SQL \"%s\"\n", z);
          if( bail_on_error ) return rc;
        }
      }
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_HAVE_ZLIB)

        }
      }else{
        open_db(&data, 0);
        echo_group_input(&data, azCmd[i]);
        rc = shell_exec(&data, azCmd[i], &zErrMsg);
        if( zErrMsg || rc ){
          if( zErrMsg!=0 ){
            shellEmitError(zErrMsg);
          }else{
            eputf("Error: unable to process SQL: %s\n", azCmd[i]);
          }
          sqlite3_free(zErrMsg);
          if( rc==0 ) rc = 1;
          goto shell_main_exit;
        }

** the text of this file.  Search for "Begin file sqlite3.h" to find the start
** of the embedded sqlite3.h header file.) Additional code files may be needed
** if you want a wrapper to interface SQLite with your choice of programming
** language. The code for the "sqlite3" command-line shell is also in a
** separate file. This file contains only code for the core SQLite library.
**
** The content in this amalgamation comes from Fossil check-in
** 9a9d0f6301faefe324261f03543023ffb6a9 with changes in files:
**
**    src/shell.c.in
*/
#define SQLITE_CORE 1
#define SQLITE_AMALGAMATION 1
#ifndef SQLITE_PRIVATE
# define SQLITE_PRIVATE static
#endif
/************** Begin file sqliteInt.h ***************************************/

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.47.0"
#define SQLITE_VERSION_NUMBER 3047000
#define SQLITE_SOURCE_ID      "2024-08-23 17:40:29 9a9d0f6301faefe324261f03543023ffb6a90823349c6946abb0df2f69b3alt1"

/*
** 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

** indicates that the expense of the operation is similar to that of a
** binary search on a unique indexed field of an SQLite table with N rows.
**
** ^The estimatedRows value is an estimate of the number of rows that
** will be returned by the strategy.
**
** The xBestIndex method may optionally populate the idxFlags field with a
** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
** output to show the idxNum has hex instead of as decimal.  Another flag is
** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
** return at most one row.
**
** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
** SQLite also assumes that if a call to the xUpdate() method is made as
** part of the same statement to delete or update a virtual table row and the
** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
** any database changes. In other words, if the xUpdate() returns
** SQLITE_CONSTRAINT, the database contents must be exactly as they were

/*
** CAPI3REF: Virtual Table Scan Flags
**
** Virtual table implementations are allowed to set the
** [sqlite3_index_info].idxFlags field to some combination of
** these bits.
*/
#define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
#define SQLITE_INDEX_SCAN_HEX    0x00000002 /* Display idxNum as hex */
                                            /* in EXPLAIN QUERY PLAN */

/*
** CAPI3REF: Virtual Table Constraint Operator Codes
**
** These macros define the allowed values for the
** [sqlite3_index_info].aConstraint[].op field.  Each value represents
** an operator that is part of a constraint term in the WHERE clause of

#define SQLITE_TESTCTRL_PENDING_BYTE            11
#define SQLITE_TESTCTRL_ASSERT                  12
#define SQLITE_TESTCTRL_ALWAYS                  13
#define SQLITE_TESTCTRL_RESERVE                 14  /* NOT USED */
#define SQLITE_TESTCTRL_JSON_SELFCHECK          14
#define SQLITE_TESTCTRL_OPTIMIZATIONS           15
#define SQLITE_TESTCTRL_ISKEYWORD               16  /* NOT USED */
#define SQLITE_TESTCTRL_GETOPT                  16
#define SQLITE_TESTCTRL_SCRATCHMALLOC           17  /* NOT USED */
#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS      17
#define SQLITE_TESTCTRL_LOCALTIME_FAULT         18
#define SQLITE_TESTCTRL_EXPLAIN_STMT            19  /* NOT USED */
#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD    19
#define SQLITE_TESTCTRL_NEVER_CORRUPT           20
#define SQLITE_TESTCTRL_VDBE_COVERAGE           21

**
**   The output text is not a copy of the document text that was tokenized.
**   It is the output of the tokenizer module. For tokendata=1 tables, this
**   includes any embedded 0x00 and trailing data.
**
**   This API can be quite slow if used with an FTS5 table created with the
**   "detail=none" or "detail=column" option.
**
** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
**   If parameter iCol is less than zero, or greater than or equal to the
**   number of columns in the table, SQLITE_RANGE is returned.
**
**   Otherwise, this function attempts to retrieve the locale associated
**   with column iCol of the current row. Usually, there is no associated
**   locale, and output parameters (*pzLocale) and (*pnLocale) are set
**   to NULL and 0, respectively. However, if the fts5_locale() function
**   was used to associate a locale with the value when it was inserted
**   into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
**   buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
**   is set to the size in bytes of the buffer, not including the
**   nul-terminator.
**
**   If successful, SQLITE_OK is returned. Or, if an error occurs, an
**   SQLite error code is returned. The final value of the output parameters
**   is undefined in this case.
**
** xTokenize_v2:
**   Tokenize text using the tokenizer belonging to the FTS5 table. This
**   API is the same as the xTokenize() API, except that it allows a tokenizer
**   locale to be specified.
*/
struct Fts5ExtensionApi {
  int iVersion;                   /* Currently always set to 4 */

  void *(*xUserData)(Fts5Context*);

  int (*xColumnCount)(Fts5Context*);
  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

  /* Below this point are iVersion>=3 only */
  int (*xQueryToken)(Fts5Context*,
      int iPhrase, int iToken,
      const char **ppToken, int *pnToken
  );
  int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);

  /* Below this point are iVersion>=4 only */
  int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
  int (*xTokenize_v2)(Fts5Context*,
    const char *pText, int nText,      /* Text to tokenize */
    const char *pLocale, int nLocale,  /* Locale to pass to tokenizer */
    void *pCtx,                        /* Context passed to xToken() */
    int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
  );
};

/*
** CUSTOM AUXILIARY FUNCTIONS
*************************************************************************/

/*************************************************************************
** CUSTOM TOKENIZERS
**
** Applications may also register custom tokenizer types. A tokenizer
** is registered by providing fts5 with a populated instance of the
** following structure. All structure methods must be defined, setting
**
** any member of the fts5_tokenizer struct to NULL leads to undefined
** behaviour. The structure methods are expected to function as follows:
**
** xCreate:
**   This function is used to allocate and initialize a tokenizer instance.
**   A tokenizer instance is required to actually tokenize text.
**
**   The first argument passed to this function is a copy of the (void*)
**   pointer provided by the application when the fts5_tokenizer_v2 object
**   was registered with FTS5 (the third argument to xCreateTokenizer()).
**   The second and third arguments are an array of nul-terminated strings
**   containing the tokenizer arguments, if any, specified following the
**   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
**   to create the FTS5 table.
**
**   The final argument is an output variable. If successful, (*ppOut)

**
** xTokenize:
**   This function is expected to tokenize the nText byte string indicated
**   by argument pText. pText may or may not be nul-terminated. The first
**   argument passed to this function is a pointer to an Fts5Tokenizer object
**   returned by an earlier call to xCreate().
**
**   The third argument indicates the reason that FTS5 is requesting
**   tokenization of the supplied text. This is always one of the following
**   four values:
**
**   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
**            or removed from the FTS table. The tokenizer is being invoked to
**            determine the set of tokens to add to (or delete from) the
**            FTS index.

**            returned by the tokenizer will be treated as a token prefix.
**
**       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
**            satisfy an fts5_api.xTokenize() request made by an auxiliary
**            function. Or an fts5_api.xColumnSize() request made by the same
**            on a columnsize=0 database.
**   </ul>
**
**   The sixth and seventh arguments passed to xTokenize() - pLocale and
**   nLocale - are a pointer to a buffer containing the locale to use for
**   tokenization (e.g. "en_US") and its size in bytes, respectively. The
**   pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
**   which case nLocale is always 0) to indicate that the tokenizer should
**   use its default locale.
**
**   For each token in the input string, the supplied callback xToken() must
**   be invoked. The first argument to it should be a copy of the pointer
**   passed as the second argument to xTokenize(). The third and fourth
**   arguments are a pointer to a buffer containing the token text, and the
**   size of the token in bytes. The 4th and 5th arguments are the byte offsets
**   of the first byte of and first byte immediately following the text from

**   If an xToken() callback returns any value other than SQLITE_OK, then
**   the tokenization should be abandoned and the xTokenize() method should
**   immediately return a copy of the xToken() return value. Or, if the
**   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
**   if an error occurs with the xTokenize() implementation itself, it
**   may abandon the tokenization and return any error code other than
**   SQLITE_OK or SQLITE_DONE.
**
**   If the tokenizer is registered using an fts5_tokenizer_v2 object,
**   then the xTokenize() method has two additional arguments - pLocale
**   and nLocale. These specify the locale that the tokenizer should use
**   for the current request. If pLocale and nLocale are both 0, then the
**   tokenizer should use its default locale. Otherwise, pLocale points to
**   an nLocale byte buffer containing the name of the locale to use as utf-8
**   text. pLocale is not nul-terminated.
**
** FTS5_TOKENIZER
**
** There is also an fts5_tokenizer object. This is an older version of
** fts5_tokenizer_v2. It is similar except that:
**
**  <ul>
**    <li> There is no "iVersion" field, and
**    <li> The xTokenize() method does not take a locale argument.
**  </ul>
**
** fts5_tokenizer tokenizers should be registered with the xCreateTokenizer()
** function, instead of xCreateTokenizer_v2(). Tokenizers implementations
** registered using either API may be retrieved using both xFindTokenizer()
** and xFindTokenizer_v2().
**
** SYNONYM SUPPORT
**
**   Custom tokenizers may also support synonyms. Consider a case in which a
**   user wishes to query for a phrase such as "first place". Using the
**   built-in tokenizers, the FTS5 query 'first + place' will match instances
**   of "first place" within the document set, but not alternative forms

**
**   When using methods (2) or (3), it is important that the tokenizer only
**   provide synonyms when tokenizing document text (method (3)) or query
**   text (method (2)), not both. Doing so will not cause any errors, but is
**   inefficient.
*/
typedef struct Fts5Tokenizer Fts5Tokenizer;
typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
struct fts5_tokenizer_v2 {
  int iVersion;             /* Currently always 2 */

  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
  void (*xDelete)(Fts5Tokenizer*);
  int (*xTokenize)(Fts5Tokenizer*,
      void *pCtx,
      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
      const char *pText, int nText,
      const char *pLocale, int nLocale,
      int (*xToken)(
        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
        int tflags,         /* Mask of FTS5_TOKEN_* flags */
        const char *pToken, /* Pointer to buffer containing token */
        int nToken,         /* Size of token in bytes */
        int iStart,         /* Byte offset of token within input text */
        int iEnd            /* Byte offset of end of token within input text */
      )
  );
};

/*
** New code should use the fts5_tokenizer_v2 type to define tokenizer
** implementations. The following type is included for legacy applications
** that still use it.
*/
typedef struct fts5_tokenizer fts5_tokenizer;
struct fts5_tokenizer {
  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
  void (*xDelete)(Fts5Tokenizer*);
  int (*xTokenize)(Fts5Tokenizer*,
      void *pCtx,
      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
      const char *pText, int nText,
      int (*xToken)(
        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
        int tflags,         /* Mask of FTS5_TOKEN_* flags */
        const char *pToken, /* Pointer to buffer containing token */
        int nToken,         /* Size of token in bytes */
        int iStart,         /* Byte offset of token within input text */
        int iEnd            /* Byte offset of end of token within input text */
      )
  );
};


/* Flags that may be passed as the third argument to xTokenize() */
#define FTS5_TOKENIZE_QUERY     0x0001
#define FTS5_TOKENIZE_PREFIX    0x0002
#define FTS5_TOKENIZE_DOCUMENT  0x0004
#define FTS5_TOKENIZE_AUX       0x0008

/* Flags that may be passed by the tokenizer implementation back to FTS5
** as the third argument to the supplied xToken callback. */
#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */

/*
** END OF CUSTOM TOKENIZERS
*************************************************************************/

/*************************************************************************
** FTS5 EXTENSION REGISTRATION API
*/
typedef struct fts5_api fts5_api;
struct fts5_api {
  int iVersion;                   /* Currently always set to 3 */

  /* Create a new tokenizer */
  int (*xCreateTokenizer)(
    fts5_api *pApi,
    const char *zName,
    void *pUserData,
    fts5_tokenizer *pTokenizer,

  int (*xCreateFunction)(
    fts5_api *pApi,
    const char *zName,
    void *pUserData,
    fts5_extension_function xFunction,
    void (*xDestroy)(void*)
  );

  /* APIs below this point are only available if iVersion>=3 */

  /* Create a new tokenizer */
  int (*xCreateTokenizer_v2)(
    fts5_api *pApi,
    const char *zName,
    void *pUserData,
    fts5_tokenizer_v2 *pTokenizer,
    void (*xDestroy)(void*)
  );

  /* Find an existing tokenizer */
  int (*xFindTokenizer_v2)(
    fts5_api *pApi,
    const char *zName,
    void **ppUserData,
    fts5_tokenizer_v2 **ppTokenizer
  );
};

/*
** END OF REGISTRATION API
*************************************************************************/

#if 0

typedef struct RenameToken RenameToken;
typedef struct Returning Returning;
typedef struct RowSet RowSet;
typedef struct Savepoint Savepoint;
typedef struct Select Select;
typedef struct SQLiteThread SQLiteThread;
typedef struct SelectDest SelectDest;
typedef struct Subquery Subquery;
typedef struct SrcItem SrcItem;
typedef struct SrcList SrcList;
typedef struct sqlite3_str StrAccum; /* Internal alias for sqlite3_str */
typedef struct Table Table;
typedef struct TableLock TableLock;
typedef struct Token Token;
typedef struct TreeView TreeView;

** Allowed values for IdList.eType, which determines which value of the a.u4
** is valid.
*/
#define EU4_NONE   0   /* Does not use IdList.a.u4 */
#define EU4_IDX    1   /* Uses IdList.a.u4.idx */
#define EU4_EXPR   2   /* Uses IdList.a.u4.pExpr -- NOT CURRENTLY USED */

/*
** Details of the implementation of a subquery.
*/
struct Subquery {
  Select *pSelect;  /* A SELECT statement used in place of a table name */
  int addrFillSub;  /* Address of subroutine to initialize a subquery */
  int regReturn;    /* Register holding return address of addrFillSub */
  int regResult;    /* Registers holding results of a co-routine */
};

/*
** The SrcItem object represents a single term in the FROM clause of a query.
** The SrcList object is mostly an array of SrcItems.
**
** The jointype starts out showing the join type between the current table
** and the next table on the list.  The parser builds the list this way.
** But sqlite3SrcListShiftJoinType() later shifts the jointypes so that each
** jointype expresses the join between the table and the previous table.
**
** In the colUsed field, the high-order bit (bit 63) is set if the table
** contains more than 63 columns and the 64-th or later column is used.
**
** Aggressive use of "union" helps keep the size of the object small.  This
** has been shown to boost performance, in addition to saving memory.
** Access to union elements is gated by the following rules which should
** always be checked, either by an if-statement or by an assert().
**
**    Field              Only access if this is true
**    ---------------    -----------------------------------
**    u1.zIndexedBy      fg.isIndexedBy
**    u1.pFuncArg        fg.isTabFunc
**    u1.nRow            !fg.isTabFunc  && !fg.isIndexedBy
**
**    u2.pIBIndex        fg.isIndexedBy
**    u2.pCteUse         fg.isCte
**
**    u3.pOn             !fg.isUsing
**    u3.pUsing          fg.isUsing
**
**    u4.zDatabase       !fg.fixedSchema && !fg.isSubquery
**    u4.pSchema         fg.fixedSchema
**    u4.pSubq           fg.isSubquery
**
** See also the sqlite3SrcListDelete() routine for assert() statements that
** check invariants on the fields of this object, especially the flags
** inside the fg struct.
*/
struct SrcItem {


  char *zName;      /* Name of the table */
  char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
  Table *pSTab;     /* Table object for zName. Mnemonic: Srcitem-TABle */




  struct {
    u8 jointype;      /* Type of join between this table and the previous */
    unsigned notIndexed :1;    /* True if there is a NOT INDEXED clause */
    unsigned isIndexedBy :1;   /* True if there is an INDEXED BY clause */
    unsigned isSubquery :1;    /* True if this term is a subquery */
    unsigned isTabFunc :1;     /* True if table-valued-function syntax */
    unsigned isCorrelated :1;  /* True if sub-query is correlated */
    unsigned isMaterialized:1; /* This is a materialized view */
    unsigned viaCoroutine :1;  /* Implemented as a co-routine */
    unsigned isRecursive :1;   /* True for recursive reference in WITH */
    unsigned fromDDL :1;       /* Comes from sqlite_schema */
    unsigned isCte :1;         /* This is a CTE */
    unsigned notCte :1;        /* This item may not match a CTE */
    unsigned isUsing :1;       /* u3.pUsing is valid */
    unsigned isOn :1;          /* u3.pOn was once valid and non-NULL */
    unsigned isSynthUsing :1;  /* u3.pUsing is synthesized from NATURAL */
    unsigned isNestedFrom :1;  /* pSelect is a SF_NestedFrom subquery */
    unsigned rowidUsed :1;     /* The ROWID of this table is referenced */
    unsigned fixedSchema :1;   /* Uses u4.pSchema, not u4.zDatabase */
    unsigned hadSchema :1;     /* Had u4.zDatabase before u4.pSchema */
  } fg;
  int iCursor;      /* The VDBE cursor number used to access this table */




  Bitmask colUsed;  /* Bit N set if column N used. Details above for N>62 */
  union {
    char *zIndexedBy;    /* Identifier from "INDEXED BY <zIndex>" clause */
    ExprList *pFuncArg;  /* Arguments to table-valued-function */
    u32 nRow;            /* Number of rows in a VALUES clause */
  } u1;
  union {
    Index *pIBIndex;  /* Index structure corresponding to u1.zIndexedBy */
    CteUse *pCteUse;  /* CTE Usage info when fg.isCte is true */
  } u2;
  union {
    Expr *pOn;        /* fg.isUsing==0 =>  The ON clause of a join */
    IdList *pUsing;   /* fg.isUsing==1 =>  The USING clause of a join */
  } u3;
  union {
    Schema *pSchema;  /* Schema to which this item is fixed */
    char *zDatabase;  /* Name of database holding this table */
    Subquery *pSubq;  /* Description of a subquery */
  } u4;
};

/*
** The OnOrUsing object represents either an ON clause or a USING clause.
** It can never be both at the same time, but it can be neither.
*/
struct OnOrUsing {

#define SF_PushDown      0x1000000 /* Modified by WHERE-clause push-down opt */
#define SF_MultiPart     0x2000000 /* Has multiple incompatible PARTITIONs */
#define SF_CopyCte       0x4000000 /* SELECT statement is a copy of a CTE */
#define SF_OrderByReqd   0x8000000 /* The ORDER BY clause may not be omitted */
#define SF_UpdateFrom   0x10000000 /* Query originates with UPDATE FROM */
#define SF_Correlated   0x20000000 /* True if references the outer context */

/* True if SrcItem X is a subquery that has SF_NestedFrom */
#define IsNestedFrom(X) \
   ((X)->fg.isSubquery && \
    ((X)->u4.pSubq->pSelect->selFlags&SF_NestedFrom)!=0)

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

#endif
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 *sqlite3SrcListAppendList(Parse *pParse, SrcList *p1, SrcList *p2);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(Parse*, SrcList*, Token*, Token*);
SQLITE_PRIVATE void sqlite3SubqueryDelete(sqlite3*,Subquery*);
SQLITE_PRIVATE Select *sqlite3SubqueryDetach(sqlite3*,SrcItem*);
SQLITE_PRIVATE int sqlite3SrcItemAttachSubquery(Parse*, SrcItem*, Select*, int);
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(Parse*, SrcList*, Token*, Token*,
                                      Token*, Select*, OnOrUsing*);
SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *, SrcList *, Token *);
SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse*, SrcList*, ExprList*);
SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *, SrcItem *);
SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(Parse*,SrcList*);
SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse*, SrcList*);

    datetimeError(p);
    return;
  }
  if( M<=2 ){
    Y--;
    M += 12;
  }
  A = (Y+4800)/100;
  B = 38 - A + (A/4);
  X1 = 36525*(Y+4716)/100;
  X2 = 306001*(M+1)/10000;
  p->iJD = (sqlite3_int64)((X1 + X2 + D + B - 1524.5 ) * 86400000);
  p->validJD = 1;
  if( p->validHMS ){
    p->iJD += p->h*3600000 + p->m*60000 + (sqlite3_int64)(p->s*1000 + 0.5);
    if( p->tz ){

  return iJD>=0 && iJD<=INT_464269060799999;
}

/*
** Compute the Year, Month, and Day from the julian day number.
*/
static void computeYMD(DateTime *p){
  int Z, alpha, A, B, C, D, E, X1;
  if( p->validYMD ) return;
  if( !p->validJD ){
    p->Y = 2000;
    p->M = 1;
    p->D = 1;
  }else if( !validJulianDay(p->iJD) ){
    datetimeError(p);
    return;
  }else{
    Z = (int)((p->iJD + 43200000)/86400000);
    alpha = (int)((Z + 32044.75)/36524.25) - 52;
    A = Z + 1 + alpha - ((alpha+100)/4) + 25;
    B = A + 1524;
    C = (int)((B - 122.1)/365.25);
    D = (36525*(C&32767))/100;
    E = (int)((B-D)/30.6001);
    X1 = (int)(30.6001*E);
    p->D = B - D - X1;
    p->M = E<14 ? E-1 : E-13;

        SrcItem *pItem;
        if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
        pItem = va_arg(ap, SrcItem*);
        assert( bArgList==0 );
        if( pItem->zAlias && !flag_altform2 ){
          sqlite3_str_appendall(pAccum, pItem->zAlias);
        }else if( pItem->zName ){
          if( pItem->fg.fixedSchema==0
           && pItem->fg.isSubquery==0
           && pItem->u4.zDatabase!=0
          ){
            sqlite3_str_appendall(pAccum, pItem->u4.zDatabase);
            sqlite3_str_append(pAccum, ".", 1);
          }
          sqlite3_str_appendall(pAccum, pItem->zName);
        }else if( pItem->zAlias ){
          sqlite3_str_appendall(pAccum, pItem->zAlias);
        }else if( ALWAYS(pItem->fg.isSubquery) ){/* Because of tag-20240424-1 */
          Select *pSel = pItem->u4.pSubq->pSelect;
          assert( pSel!=0 );
          if( pSel->selFlags & SF_NestedFrom ){
            sqlite3_str_appendf(pAccum, "(join-%u)", pSel->selId);
          }else if( pSel->selFlags & SF_MultiValue ){
            assert( !pItem->fg.isTabFunc && !pItem->fg.isIndexedBy );
            sqlite3_str_appendf(pAccum, "%u-ROW VALUES CLAUSE",
                                pItem->u1.nRow);
          }else{

    const SrcItem *pItem = &pSrc->a[i];
    StrAccum x;
    int n = 0;
    char zLine[1000];
    sqlite3StrAccumInit(&x, 0, zLine, sizeof(zLine), 0);
    x.printfFlags |= SQLITE_PRINTF_INTERNAL;
    sqlite3_str_appendf(&x, "{%d:*} %!S", pItem->iCursor, pItem);
    if( pItem->pSTab ){
      sqlite3_str_appendf(&x, " tab=%Q nCol=%d ptr=%p used=%llx%s",
           pItem->pSTab->zName, pItem->pSTab->nCol, pItem->pSTab,
           pItem->colUsed,
           pItem->fg.rowidUsed ? "+rowid" : "");
    }
    if( (pItem->fg.jointype & (JT_LEFT|JT_RIGHT))==(JT_LEFT|JT_RIGHT) ){
      sqlite3_str_appendf(&x, " FULL-OUTER-JOIN");
    }else if( pItem->fg.jointype & JT_LEFT ){
      sqlite3_str_appendf(&x, " LEFT-JOIN");

    }
    if( pItem->fg.isTabFunc )      sqlite3_str_appendf(&x, " isTabFunc");
    if( pItem->fg.isCorrelated )   sqlite3_str_appendf(&x, " isCorrelated");
    if( pItem->fg.isMaterialized ) sqlite3_str_appendf(&x, " isMaterialized");
    if( pItem->fg.viaCoroutine )   sqlite3_str_appendf(&x, " viaCoroutine");
    if( pItem->fg.notCte )         sqlite3_str_appendf(&x, " notCte");
    if( pItem->fg.isNestedFrom )   sqlite3_str_appendf(&x, " isNestedFrom");
    if( pItem->fg.fixedSchema )    sqlite3_str_appendf(&x, " fixedSchema");
    if( pItem->fg.hadSchema )      sqlite3_str_appendf(&x, " hadSchema");
    if( pItem->fg.isSubquery )     sqlite3_str_appendf(&x, " isSubquery");

    sqlite3StrAccumFinish(&x);
    sqlite3TreeViewItem(pView, zLine, i<pSrc->nSrc-1);
    n = 0;
    if( pItem->fg.isSubquery ) n++;
    if( pItem->fg.isTabFunc ) n++;
    if( pItem->fg.isUsing ) n++;
    if( pItem->fg.isUsing ){
      sqlite3TreeViewIdList(pView, pItem->u3.pUsing, (--n)>0, "USING");
    }
    if( pItem->fg.isSubquery ){
      assert( n==1 );
      if( pItem->pSTab ){
        Table *pTab = pItem->pSTab;
        sqlite3TreeViewColumnList(pView, pTab->aCol, pTab->nCol, 1);
      }
      assert( (int)pItem->fg.isNestedFrom == IsNestedFrom(pItem) );
      sqlite3TreeViewPush(&pView, 0);
      sqlite3TreeViewLine(pView, "SUBQUERY");
      sqlite3TreeViewPop(&pView);
      sqlite3TreeViewSelect(pView, pItem->u4.pSubq->pSelect, 0);
    }
    if( pItem->fg.isTabFunc ){
      sqlite3TreeViewExprList(pView, pItem->u1.pFuncArg, 0, "func-args:");
    }
    sqlite3TreeViewPop(&pView);
  }
}

/*
** Allowed values for the unixFile.ctrlFlags bitmask:
*/
#define UNIXFILE_EXCL        0x01     /* Connections from one process only */
#define UNIXFILE_RDONLY      0x02     /* Connection is read only */
#define UNIXFILE_PERSIST_WAL 0x04     /* Persistent WAL mode */
#if !defined(SQLITE_DISABLE_DIRSYNC) && !defined(_AIX)
# define UNIXFILE_DIRSYNC    0x08     /* Directory sync needed */
#else
# define UNIXFILE_DIRSYNC    0x00
#endif
#define UNIXFILE_PSOW        0x10     /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
#define UNIXFILE_DELETE      0x20     /* Delete on close */
#define UNIXFILE_URI         0x40     /* Filename might have query parameters */

    sqlite3VdbeMemRealify(pIn1);
    REGISTER_TRACE(pOp->p1, pIn1);
  }
  break;
}
#endif

#if !defined(SQLITE_OMIT_CAST) || !defined(SQLITE_OMIT_ANALYZE)
/* Opcode: Cast P1 P2 * * *
** Synopsis: affinity(r[P1])
**
** Force the value in register P1 to be the type defined by P2.
**
** <ul>
** <li> P2=='A' &rarr; BLOB

  SrcList *pSrc;
  int i;
  SrcItem *pItem;

  pSrc = p->pSrc;
  if( ALWAYS(pSrc) ){
    for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
      if( pItem->fg.isSubquery
       && sqlite3WalkSelect(pWalker, pItem->u4.pSubq->pSelect)
      ){
        return WRC_Abort;
      }
      if( pItem->fg.isTabFunc
       && sqlite3WalkExprList(pWalker, pItem->u1.pFuncArg)
      ){
        return WRC_Abort;
      }

  SrcItem *pMatch,        /* Source table containing the column */
  i16 iColumn             /* The column number */
){
  Expr *pNew = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0);
  if( pNew ){
    pNew->iTable = pMatch->iCursor;
    pNew->iColumn = iColumn;
    pNew->y.pTab = pMatch->pSTab;
    assert( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 );
    ExprSetProperty(pNew, EP_CanBeNull);
    *ppList = sqlite3ExprListAppend(pParse, *ppList, pNew);
  }
}

/*

  do{
    ExprList *pEList;
    SrcList *pSrcList = pNC->pSrcList;

    if( pSrcList ){
      for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
        u8 hCol;
        pTab = pItem->pSTab;
        assert( pTab!=0 && pTab->zName!=0 );
        assert( pTab->nCol>0 || pParse->nErr );
        assert( (int)pItem->fg.isNestedFrom == IsNestedFrom(pItem));
        if( pItem->fg.isNestedFrom ){
          /* In this case, pItem is a subquery that has been formed from a
          ** parenthesized subset of the FROM clause terms.  Example:
          **   .... FROM t1 LEFT JOIN (t2 RIGHT JOIN t3 USING(x)) USING(y) ...
          **                          \_________________________/
          **             This pItem -------------^
          */
          int hit = 0;
          Select *pSel;
          assert( pItem->fg.isSubquery );
          assert( pItem->u4.pSubq!=0 );
          pSel = pItem->u4.pSubq->pSelect;
          assert( pSel!=0 );
          pEList = pSel->pEList;
          assert( pEList!=0 );
          assert( pEList->nExpr==pTab->nCol );
          for(j=0; j<pEList->nExpr; j++){
            int bRowid = 0;       /* True if possible rowid match */
            if( !sqlite3MatchEName(&pEList->a[j], zCol, zTab, zDb, &bRowid) ){
              continue;
            }

          ** if there is a single VIEW candidate or if there is a single
          ** non-VIEW candidate plus multiple VIEW candidates.  In other
          ** words non-VIEW candidate terms take precedence over VIEWs.
          */
          if( cntTab==0
           || (cntTab==1
               && ALWAYS(pMatch!=0)
               && ALWAYS(pMatch->pSTab!=0)
               && (pMatch->pSTab->tabFlags & TF_Ephemeral)!=0
               && (pTab->tabFlags & TF_Ephemeral)==0)
          ){
            cntTab = 1;
            pMatch = pItem;
          }else{
            cntTab++;
          }
#else
          /* The (much more common) non-SQLITE_ALLOW_ROWID_IN_VIEW case is
          ** simpler since we require exactly one candidate, which will
          ** always be a non-VIEW
          */
          cntTab++;
          pMatch = pItem;
#endif
        }
      }
      if( pMatch ){
        pExpr->iTable = pMatch->iCursor;
        assert( ExprUseYTab(pExpr) );
        pExpr->y.pTab = pMatch->pSTab;
        if( (pMatch->fg.jointype & (JT_LEFT|JT_LTORJ))!=0 ){
          ExprSetProperty(pExpr, EP_CanBeNull);
        }
        pSchema = pExpr->y.pTab->pSchema;
      }
    } /* if( pSrcList ) */

        }
      }
#endif /* SQLITE_OMIT_TRIGGER */
#ifndef SQLITE_OMIT_UPSERT
      if( (pNC->ncFlags & NC_UUpsert)!=0 && zTab!=0 ){
        Upsert *pUpsert = pNC->uNC.pUpsert;
        if( pUpsert && sqlite3StrICmp("excluded",zTab)==0 ){
          pTab = pUpsert->pUpsertSrc->a[0].pSTab;
          pExpr->iTable = EXCLUDED_TABLE_NUMBER;
        }
      }
#endif /* SQLITE_OMIT_UPSERT */

      if( pTab ){
        int iCol;

    ** Perhaps the name is a reference to the ROWID
    */
    if( cnt==0
     && cntTab>=1
     && pMatch
     && (pNC->ncFlags & (NC_IdxExpr|NC_GenCol))==0
     && sqlite3IsRowid(zCol)
     && ALWAYS(VisibleRowid(pMatch->pSTab) || pMatch->fg.isNestedFrom)
    ){
      cnt = cntTab;
#if SQLITE_ALLOW_ROWID_IN_VIEW+0==2
      if( pMatch->pSTab!=0 && IsView(pMatch->pSTab) ){
        eNewExprOp = TK_NULL;
      }
#endif
      if( pMatch->fg.isNestedFrom==0 ) pExpr->iColumn = -1;
      pExpr->affExpr = SQLITE_AFF_INTEGER;
    }

*/
SQLITE_PRIVATE Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){
  Expr *p = sqlite3ExprAlloc(db, TK_COLUMN, 0, 0);
  if( p ){
    SrcItem *pItem = &pSrc->a[iSrc];
    Table *pTab;
    assert( ExprUseYTab(p) );
    pTab = p->y.pTab = pItem->pSTab;
    p->iTable = pItem->iCursor;
    if( p->y.pTab->iPKey==iCol ){
      p->iColumn = -1;
    }else{
      p->iColumn = (ynVar)iCol;
      if( (pTab->tabFlags & TF_HasGenerated)!=0
       && (pTab->aCol[iCol].colFlags & COLFLAG_GENERATED)!=0

    case TK_ROW: {
      SrcList *pSrcList = pNC->pSrcList;
      SrcItem *pItem;
      assert( pSrcList && pSrcList->nSrc>=1 );
      pItem = pSrcList->a;
      pExpr->op = TK_COLUMN;
      assert( ExprUseYTab(pExpr) );
      pExpr->y.pTab = pItem->pSTab;
      pExpr->iTable = pItem->iCursor;
      pExpr->iColumn--;
      pExpr->affExpr = SQLITE_AFF_INTEGER;
      break;
    }

    /* An optimization:  Attempt to convert

    /* If the SF_Converted flags is set, then this Select object was
    ** was created by the convertCompoundSelectToSubquery() function.
    ** In this case the ORDER BY clause (p->pOrderBy) should be resolved
    ** as if it were part of the sub-query, not the parent. This block
    ** moves the pOrderBy down to the sub-query. It will be moved back
    ** after the names have been resolved.  */
    if( p->selFlags & SF_Converted ){
      Select *pSub;
      assert( p->pSrc->a[0].fg.isSubquery );
      assert( p->pSrc->a[0].u4.pSubq!=0 );
      pSub = p->pSrc->a[0].u4.pSubq->pSelect;
      assert( pSub!=0 );
      assert( p->pSrc->nSrc==1 && p->pOrderBy );
      assert( pSub->pPrior && pSub->pOrderBy==0 );
      pSub->pOrderBy = p->pOrderBy;
      p->pOrderBy = 0;
    }

    /* Recursively resolve names in all subqueries in the FROM clause
    */
    if( pOuterNC ) pOuterNC->nNestedSelect++;
    for(i=0; i<p->pSrc->nSrc; i++){
      SrcItem *pItem = &p->pSrc->a[i];
      assert( pItem->zName!=0
              || pItem->fg.isSubquery );  /* Test of tag-20240424-1*/
      if( pItem->fg.isSubquery
       && (pItem->u4.pSubq->pSelect->selFlags & SF_Resolved)==0
      ){
        int nRef = pOuterNC ? pOuterNC->nRef : 0;
        const char *zSavedContext = pParse->zAuthContext;

        if( pItem->zName ) pParse->zAuthContext = pItem->zName;
        sqlite3ResolveSelectNames(pParse, pItem->u4.pSubq->pSelect, pOuterNC);
        pParse->zAuthContext = zSavedContext;
        if( pParse->nErr ) return WRC_Abort;
        assert( db->mallocFailed==0 );

        /* If the number of references to the outer context changed when
        ** expressions in the sub-select were resolved, the sub-select
        ** is correlated. It is not required to check the refcount on any

    /* If this is a converted compound query, move the ORDER BY clause from
    ** the sub-query back to the parent query. At this point each term
    ** within the ORDER BY clause has been transformed to an integer value.
    ** These integers will be replaced by copies of the corresponding result
    ** set expressions by the call to resolveOrderGroupBy() below.  */
    if( p->selFlags & SF_Converted ){
      Select *pSub;
      assert( p->pSrc->a[0].fg.isSubquery );
      pSub = p->pSrc->a[0].u4.pSubq->pSelect;
      assert( pSub!=0 );
      p->pOrderBy = pSub->pOrderBy;
      pSub->pOrderBy = 0;
    }

    /* Process the ORDER BY clause for singleton SELECT statements.
    ** The ORDER BY clause for compounds SELECT statements is handled
    ** below, after all of the result-sets for all of the elements of

  assert( type==NC_IsCheck || type==NC_PartIdx || type==NC_IdxExpr
          || type==NC_GenCol || 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].pSTab = pTab;
    sSrc.a[0].iCursor = -1;
    if( pTab->pSchema!=pParse->db->aDb[1].pSchema ){
      /* Cause EP_FromDDL to be set on TK_FUNCTION nodes of non-TEMP
      ** schema elements */
      type |= NC_FromDDL;
    }
  }

  pNew = sqlite3DbMallocRawNN(db, nByte );
  if( pNew==0 ) return 0;
  pNew->nSrc = pNew->nAlloc = p->nSrc;
  for(i=0; i<p->nSrc; i++){
    SrcItem *pNewItem = &pNew->a[i];
    const SrcItem *pOldItem = &p->a[i];
    Table *pTab;
    pNewItem->fg = pOldItem->fg;
    if( pOldItem->fg.isSubquery ){
      Subquery *pNewSubq = sqlite3DbMallocRaw(db, sizeof(Subquery));
      if( pNewSubq==0 ){
        assert( db->mallocFailed );
        pNewItem->fg.isSubquery = 0;
      }else{
        memcpy(pNewSubq, pOldItem->u4.pSubq, sizeof(*pNewSubq));
        pNewSubq->pSelect = sqlite3SelectDup(db, pNewSubq->pSelect, flags);
        if( pNewSubq->pSelect==0 ){
          sqlite3DbFree(db, pNewSubq);
          pNewSubq = 0;
          pNewItem->fg.isSubquery = 0;
        }
      }
      pNewItem->u4.pSubq = pNewSubq;
    }else if( pOldItem->fg.fixedSchema ){
      pNewItem->u4.pSchema = pOldItem->u4.pSchema;
    }else{
      pNewItem->u4.zDatabase = sqlite3DbStrDup(db, pOldItem->u4.zDatabase);
    }
    pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
    pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);

    pNewItem->iCursor = pOldItem->iCursor;



    if( pNewItem->fg.isIndexedBy ){
      pNewItem->u1.zIndexedBy = sqlite3DbStrDup(db, pOldItem->u1.zIndexedBy);
    }else if( pNewItem->fg.isTabFunc ){
      pNewItem->u1.pFuncArg =
          sqlite3ExprListDup(db, pOldItem->u1.pFuncArg, flags);
    }else{
      pNewItem->u1.nRow = pOldItem->u1.nRow;
    }
    pNewItem->u2 = pOldItem->u2;
    if( pNewItem->fg.isCte ){
      pNewItem->u2.pCteUse->nUse++;
    }
    pTab = pNewItem->pSTab = pOldItem->pSTab;
    if( pTab ){
      pTab->nTabRef++;
    }

    if( pOldItem->fg.isUsing ){
      assert( pNewItem->fg.isUsing );
      pNewItem->u3.pUsing = sqlite3IdListDup(db, pOldItem->u3.pUsing);
    }else{
      pNewItem->u3.pOn = sqlite3ExprDup(db, pOldItem->u3.pOn, flags);
    }
    pNewItem->colUsed = pOldItem->colUsed;

      sqlite3SelectDelete(db, pNew);
      break;
    }
    *pp = pNew;
    pp = &pNew->pPrior;
    pNext = pNew;
  }

  return pRet;
}
#else
SQLITE_PRIVATE Select *sqlite3SelectDup(sqlite3 *db, const Select *p, int flags){
  assert( p==0 );
  return 0;
}

  }
  assert( p->pGroupBy==0 );              /* Has no GROUP BY clause */
  if( p->pLimit ) return 0;              /* Has no LIMIT clause */
  if( p->pWhere ) return 0;              /* Has no WHERE clause */
  pSrc = p->pSrc;
  assert( pSrc!=0 );
  if( pSrc->nSrc!=1 ) return 0;          /* Single term in FROM clause */
  if( pSrc->a[0].fg.isSubquery) return 0;/* FROM is not a subquery or view */
  pTab = pSrc->a[0].pSTab;
  assert( pTab!=0 );
  assert( !IsView(pTab)  );              /* FROM clause is not a view */
  if( IsVirtual(pTab) ) return 0;        /* FROM clause not a virtual table */
  pEList = p->pEList;
  assert( pEList!=0 );
  /* All SELECT results must be columns. */
  for(i=0; i<pEList->nExpr; i++){

    int iDb;                               /* Database idx for pTab */
    ExprList *pEList = p->pEList;
    int nExpr = pEList->nExpr;

    assert( p->pEList!=0 );             /* Because of isCandidateForInOpt(p) */
    assert( p->pEList->a[0].pExpr!=0 ); /* Because of isCandidateForInOpt(p) */
    assert( p->pSrc!=0 );               /* Because of isCandidateForInOpt(p) */
    pTab = p->pSrc->a[0].pSTab;

    /* Code an OP_Transaction and OP_TableLock for <table>. */
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    assert( iDb>=0 && iDb<SQLITE_MAX_DB );
    sqlite3CodeVerifySchema(pParse, iDb);
    sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

          pSel->pSrc = 0;
          sqlite3SelectDelete(db, pSel);
        }
        if( pStep->pFrom ){
          int i;
          for(i=0; i<pStep->pFrom->nSrc && rc==SQLITE_OK; i++){
            SrcItem *p = &pStep->pFrom->a[i];
            if( p->fg.isSubquery ){
              assert( p->u4.pSubq!=0 );
              sqlite3SelectPrep(pParse, p->u4.pSubq->pSelect, 0);
            }
          }
        }

        if(  db->mallocFailed ){
          rc = SQLITE_NOMEM;
        }

      sqlite3WalkExprList(pWalker, pUpsert->pUpsertTarget);
      sqlite3WalkExprList(pWalker, pUpsert->pUpsertSet);
      sqlite3WalkExpr(pWalker, pUpsert->pUpsertWhere);
      sqlite3WalkExpr(pWalker, pUpsert->pUpsertTargetWhere);
    }
    if( pStep->pFrom ){
      int i;
      SrcList *pFrom = pStep->pFrom;
      for(i=0; i<pFrom->nSrc; i++){
        if( pFrom->a[i].fg.isSubquery ){
          assert( pFrom->a[i].u4.pSubq!=0 );
          sqlite3WalkSelect(pWalker, pFrom->a[i].u4.pSubq->pSelect);
        }
      }
    }
  }
}

/*
** Free the contents of Parse object (*pParse). Do not free the memory

  }
  if( NEVER(pSrc==0) ){
    assert( pWalker->pParse->db->mallocFailed );
    return WRC_Abort;
  }
  for(i=0; i<pSrc->nSrc; i++){
    SrcItem *pItem = &pSrc->a[i];
    if( pItem->pSTab==p->pTab ){
      renameTokenFind(pWalker->pParse, p, pItem->zName);
    }
  }
  renameWalkWith(pWalker, pSelect);

  return WRC_Continue;
}

  SrcItem *pItem;
  sqlite3 *db = pFix->pParse->db;
  int iDb = sqlite3FindDbName(db, pFix->zDb);
  SrcList *pList = pSelect->pSrc;

  if( NEVER(pList==0) ) return WRC_Continue;
  for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
    if( pFix->bTemp==0 && pItem->fg.isSubquery==0 ){
      if( pItem->fg.fixedSchema==0 && pItem->u4.zDatabase!=0 ){
        if( iDb!=sqlite3FindDbName(db, pItem->u4.zDatabase) ){
          sqlite3ErrorMsg(pFix->pParse,
              "%s %T cannot reference objects in database %s",
              pFix->zType, pFix->pName, pItem->u4.zDatabase);
          return WRC_Abort;
        }
        sqlite3DbFree(db, pItem->u4.zDatabase);

        pItem->fg.notCte = 1;
        pItem->fg.hadSchema = 1;
      }
      pItem->u4.pSchema = pFix->pSchema;
      pItem->fg.fromDDL = 1;
      pItem->fg.fixedSchema = 1;
    }
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
    if( pList->a[i].fg.isUsing==0
     && sqlite3WalkExpr(&pFix->w, pList->a[i].u3.pOn)
    ){
      return WRC_Abort;
    }

  if( pExpr->op==TK_TRIGGER ){
    pTab = pParse->pTriggerTab;
  }else{
    assert( pTabList );
    for(iSrc=0; iSrc<pTabList->nSrc; iSrc++){
      if( pExpr->iTable==pTabList->a[iSrc].iCursor ){
        pTab = pTabList->a[iSrc].pSTab;
        break;
      }
    }
  }
  iCol = pExpr->iColumn;
  if( pTab==0 ) return;

*/
SQLITE_PRIVATE Table *sqlite3LocateTableItem(
  Parse *pParse,
  u32 flags,
  SrcItem *p
){
  const char *zDb;

  if( p->fg.fixedSchema ){
    int iDb = sqlite3SchemaToIndex(pParse->db, p->u4.pSchema);
    zDb = pParse->db->aDb[iDb].zDbSName;
  }else{
    assert( !p->fg.isSubquery );
    zDb = p->u4.zDatabase;
  }
  return sqlite3LocateTable(pParse, flags, p->zName, zDb);
}

/*
** Return the preferred table name for system tables.  Translate legacy
** names into the new preferred names, as appropriate.

  int iDb;

  if( db->mallocFailed ){
    goto exit_drop_table;
  }
  assert( pParse->nErr==0 );
  assert( pName->nSrc==1 );
  assert( pName->a[0].fg.fixedSchema==0 );
  assert( pName->a[0].fg.isSubquery==0 );
  if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;
  if( noErr ) db->suppressErr++;
  assert( isView==0 || isView==LOCATE_VIEW );
  pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);
  if( noErr ) db->suppressErr--;

  if( pTab==0 ){
    if( noErr ){
      sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].u4.zDatabase);
      sqlite3ForceNotReadOnly(pParse);
    }
    goto exit_drop_table;
  }
  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
  assert( iDb>=0 && iDb<db->nDb );

  int iDb;

  if( db->mallocFailed ){
    goto exit_drop_index;
  }
  assert( pParse->nErr==0 );   /* Never called with prior non-OOM errors */
  assert( pName->nSrc==1 );
  assert( pName->a[0].fg.fixedSchema==0 );
  assert( pName->a[0].fg.isSubquery==0 );
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto exit_drop_index;
  }
  pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].u4.zDatabase);
  if( pIndex==0 ){
    if( !ifExists ){
      sqlite3ErrorMsg(pParse, "no such index: %S", pName->a);
    }else{
      sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].u4.zDatabase);
      sqlite3ForceNotReadOnly(pParse);
    }
    pParse->checkSchema = 1;
    goto exit_drop_index;
  }
  if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){
    sqlite3ErrorMsg(pParse, "index associated with UNIQUE "

      pList = pNew;
    }
  }
  pItem = &pList->a[pList->nSrc-1];
  if( pDatabase && pDatabase->z==0 ){
    pDatabase = 0;
  }
  assert( pItem->fg.fixedSchema==0 );
  assert( pItem->fg.isSubquery==0 );
  if( pDatabase ){
    pItem->zName = sqlite3NameFromToken(db, pDatabase);
    pItem->u4.zDatabase = sqlite3NameFromToken(db, pTable);
  }else{
    pItem->zName = sqlite3NameFromToken(db, pTable);
    pItem->u4.zDatabase = 0;
  }
  return pList;
}

/*
** Assign VdbeCursor index numbers to all tables in a SrcList
*/
SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
  int i;
  SrcItem *pItem;
  assert( pList || pParse->db->mallocFailed );
  if( ALWAYS(pList) ){
    for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
      if( pItem->iCursor>=0 ) continue;
      pItem->iCursor = pParse->nTab++;
      if( pItem->fg.isSubquery ){
        assert( pItem->u4.pSubq!=0 );
        assert( pItem->u4.pSubq->pSelect!=0 );
        assert( pItem->u4.pSubq->pSelect->pSrc!=0 );
        sqlite3SrcListAssignCursors(pParse, pItem->u4.pSubq->pSelect->pSrc);
      }
    }
  }
}

/*
** Delete a Subquery object and its substructure.
*/
SQLITE_PRIVATE void sqlite3SubqueryDelete(sqlite3 *db, Subquery *pSubq){
  assert( pSubq!=0 && pSubq->pSelect!=0 );
  sqlite3SelectDelete(db, pSubq->pSelect);
  sqlite3DbFree(db, pSubq);
}

/*
** Remove a Subquery from a SrcItem.  Return the associated Select object.
** The returned Select becomes the responsibility of the caller.
*/
SQLITE_PRIVATE Select *sqlite3SubqueryDetach(sqlite3 *db, SrcItem *pItem){
  Select *pSel;
  assert( pItem!=0 );
  assert( pItem->fg.isSubquery );
  pSel = pItem->u4.pSubq->pSelect;
  sqlite3DbFree(db, pItem->u4.pSubq);
  pItem->u4.pSubq = 0;
  pItem->fg.isSubquery = 0;
  return pSel;
}

/*
** Delete an entire SrcList including all its substructure.
*/
SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
  int i;
  SrcItem *pItem;
  assert( db!=0 );
  if( pList==0 ) return;
  for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){

    /* Check invariants on SrcItem */
    assert( !pItem->fg.isIndexedBy || !pItem->fg.isTabFunc );
    assert( !pItem->fg.isCte || !pItem->fg.isIndexedBy );
    assert( !pItem->fg.fixedSchema || !pItem->fg.isSubquery );
    assert( !pItem->fg.isSubquery || (pItem->u4.pSubq!=0 &&
                                      pItem->u4.pSubq->pSelect!=0) );

    if( pItem->zName ) sqlite3DbNNFreeNN(db, pItem->zName);
    if( pItem->zAlias ) sqlite3DbNNFreeNN(db, pItem->zAlias);
    if( pItem->fg.isSubquery ){
      sqlite3SubqueryDelete(db, pItem->u4.pSubq);
    }else if( pItem->fg.fixedSchema==0 && pItem->u4.zDatabase!=0 ){
      sqlite3DbNNFreeNN(db, pItem->u4.zDatabase);
    }
    if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
    if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
    sqlite3DeleteTable(db, pItem->pSTab);

    if( pItem->fg.isUsing ){
      sqlite3IdListDelete(db, pItem->u3.pUsing);
    }else if( pItem->u3.pOn ){
      sqlite3ExprDelete(db, pItem->u3.pOn);
    }
  }
  sqlite3DbNNFreeNN(db, pList);
}

/*
** Attach a Subquery object to pItem->uv.pSubq.  Set the
** pSelect value but leave all the other values initialized
** to zero.
**
** A copy of the Select object is made if dupSelect is true, and the
** SrcItem takes responsibility for deleting the copy.  If dupSelect is
** false, ownership of the Select passes to the SrcItem.  Either way,
** the SrcItem will take responsibility for deleting the Select.
**
** When dupSelect is zero, that means the Select might get deleted right
** away if there is an OOM error.  Beware.
**
** Return non-zero on success.  Return zero on an OOM error.
*/
SQLITE_PRIVATE int sqlite3SrcItemAttachSubquery(
  Parse *pParse,     /* Parsing context */
  SrcItem *pItem,    /* Item to which the subquery is to be attached */
  Select *pSelect,   /* The subquery SELECT.  Must be non-NULL */
  int dupSelect      /* If true, attach a copy of pSelect, not pSelect itself.*/
){
  Subquery *p;
  assert( pSelect!=0 );
  assert( pItem->fg.isSubquery==0 );
  if( pItem->fg.fixedSchema ){
    pItem->u4.pSchema = 0;
    pItem->fg.fixedSchema = 0;
  }else if( pItem->u4.zDatabase!=0 ){
    sqlite3DbFree(pParse->db, pItem->u4.zDatabase);
    pItem->u4.zDatabase = 0;
  }
  if( dupSelect ){
    pSelect = sqlite3SelectDup(pParse->db, pSelect, 0);
    if( pSelect==0 ) return 0;
  }
  p = pItem->u4.pSubq = sqlite3DbMallocRawNN(pParse->db, sizeof(Subquery));
  if( p==0 ){
    sqlite3SelectDelete(pParse->db, pSelect);
    return 0;
  }
  pItem->fg.isSubquery = 1;
  p->pSelect = pSelect;
  assert( offsetof(Subquery, pSelect)==0 );
  memset(((char*)p)+sizeof(p->pSelect), 0, sizeof(*p)-sizeof(p->pSelect));
  return 1;
}


/*
** This routine is called by the parser to add a new term to the
** end of a growing FROM clause.  The "p" parameter is the part of
** the FROM clause that has already been constructed.  "p" is NULL
** if this is the first term of the FROM clause.  pTable and pDatabase
** are the name of the table and database named in the FROM clause term.

    Token *pToken = (ALWAYS(pDatabase) && pDatabase->z) ? pDatabase : pTable;
    sqlite3RenameTokenMap(pParse, pItem->zName, pToken);
  }
  assert( pAlias!=0 );
  if( pAlias->n ){
    pItem->zAlias = sqlite3NameFromToken(db, pAlias);
  }
  assert( pSubquery==0 || pDatabase==0 );
  if( pSubquery ){
    if( sqlite3SrcItemAttachSubquery(pParse, pItem, pSubquery, 0) ){
      if( pSubquery->selFlags & SF_NestedFrom ){
        pItem->fg.isNestedFrom = 1;
      }
    }
  }
  assert( pOnUsing==0 || pOnUsing->pOn==0 || pOnUsing->pUsing==0 );
  assert( pItem->fg.isUsing==0 );
  if( pOnUsing==0 ){
    pItem->u3.pOn = 0;
  }else if( pOnUsing->pUsing ){

** the name of a single table, as one might find in an INSERT, DELETE,
** or UPDATE statement.  Look up that table in the symbol table and
** return a pointer.  Set an error message and return NULL if the table
** name is not found or if any other error occurs.
**
** The following fields are initialized appropriate in pSrc:
**
**    pSrc->a[0].spTab        Pointer to the Table object
**    pSrc->a[0].u2.pIBIndex  Pointer to the INDEXED BY index, if there is one
**
*/
SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
  SrcItem *pItem = pSrc->a;
  Table *pTab;
  assert( pItem && pSrc->nSrc>=1 );
  pTab = sqlite3LocateTableItem(pParse, 0, pItem);
  if( pItem->pSTab ) sqlite3DeleteTable(pParse->db, pItem->pSTab);
  pItem->pSTab = pTab;
  pItem->fg.notCte = 1;
  if( pTab ){
    pTab->nTabRef++;
    if( pItem->fg.isIndexedBy && sqlite3IndexedByLookup(pParse, pItem) ){
      pTab = 0;
    }
  }

  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);
    assert( pFrom->a[0].fg.fixedSchema==0 && pFrom->a[0].fg.isSubquery==0 );
    pFrom->a[0].u4.zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
    assert( pFrom->a[0].fg.isUsing==0 );
    assert( pFrom->a[0].u3.pOn==0 );
  }
  pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, pOrderBy,
                          SF_IncludeHidden, pLimit);
  sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
  sqlite3Select(pParse, pSel, &dest);

  **   DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
  ** becomes:
  **   DELETE FROM table_a WHERE rowid IN (
  **     SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
  **   );
  */

  pTab = pSrc->a[0].pSTab;
  if( HasRowid(pTab) ){
    pLhs = sqlite3PExpr(pParse, TK_ROW, 0, 0);
    pEList = sqlite3ExprListAppend(
        pParse, 0, sqlite3PExpr(pParse, TK_ROW, 0, 0)
    );
  }else{
    Index *pPk = sqlite3PrimaryKeyIndex(pTab);

        pLhs->x.pList = sqlite3ExprListDup(db, pEList, 0);
      }
    }
  }

  /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
  ** and the SELECT subtree. */
  pSrc->a[0].pSTab = 0;
  pSelectSrc = sqlite3SrcListDup(db, pSrc, 0);
  pSrc->a[0].pSTab = pTab;
  if( pSrc->a[0].fg.isIndexedBy ){
    assert( pSrc->a[0].fg.isCte==0 );
    pSrc->a[0].u2.pIBIndex = 0;
    pSrc->a[0].fg.isIndexedBy = 0;
    sqlite3DbFree(db, pSrc->a[0].u1.zIndexedBy);
  }else if( pSrc->a[0].fg.isCte ){
    pSrc->a[0].u2.pCteUse->nUse++;

    assert( aiCol || pFKey->nCol==1 );

    /* Create a SrcList structure containing the child table.  We need the
    ** child table as a SrcList for sqlite3WhereBegin() */
    pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
    if( pSrc ){
      SrcItem *pItem = pSrc->a;
      pItem->pSTab = pFKey->pFrom;
      pItem->zName = pFKey->pFrom->zName;
      pItem->pSTab->nTabRef++;
      pItem->iCursor = pParse->nTab++;

      if( regNew!=0 ){
        fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
      }
      if( regOld!=0 ){
        int eAction = pFKey->aAction[aChange!=0];

      if( pRaise ){
        pRaise->affExpr = OE_Abort;
      }
      pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
      if( pSrc ){
        assert( pSrc->nSrc==1 );
        pSrc->a[0].zName = sqlite3DbStrDup(db, zFrom);
        assert( pSrc->a[0].fg.fixedSchema==0 && pSrc->a[0].fg.isSubquery==0 );
        pSrc->a[0].u4.zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
      }
      pSelect = sqlite3SelectNew(pParse,
          sqlite3ExprListAppend(pParse, 0, pRaise),
          pSrc,
          pWhere,
          0, 0, 0, 0, 0
      );

** If argument pVal is a Select object returned by an sqlite3MultiValues()
** that was able to use the co-routine optimization, finish coding the
** co-routine.
*/
SQLITE_PRIVATE void sqlite3MultiValuesEnd(Parse *pParse, Select *pVal){
  if( ALWAYS(pVal) && pVal->pSrc->nSrc>0 ){
    SrcItem *pItem = &pVal->pSrc->a[0];
    assert( (pItem->fg.isSubquery && pItem->u4.pSubq!=0) || pParse->nErr );
    if( pItem->fg.isSubquery ){
      sqlite3VdbeEndCoroutine(pParse->pVdbe, pItem->u4.pSubq->regReturn);
      sqlite3VdbeJumpHere(pParse->pVdbe, pItem->u4.pSubq->addrFillSub - 1);
    }
  }
}

/*
** Return true if all expressions in the expression-list passed as the
** only argument are constant.
*/

      ** the correct text encoding.  */
      if( (pParse->db->mDbFlags & DBFLAG_SchemaKnownOk)==0 ){
        sqlite3ReadSchema(pParse);
      }

      if( pRet ){
        SelectDest dest;
        Subquery *pSubq;
        pRet->pSrc->nSrc = 1;
        pRet->pPrior = pLeft->pPrior;
        pRet->op = pLeft->op;
        if( pRet->pPrior ) pRet->selFlags |= SF_Values;
        pLeft->pPrior = 0;
        pLeft->op = TK_SELECT;
        assert( pLeft->pNext==0 );
        assert( pRet->pNext==0 );
        p = &pRet->pSrc->a[0];

        p->fg.viaCoroutine = 1;


        p->iCursor = -1;
        assert( !p->fg.isIndexedBy && !p->fg.isTabFunc );
        p->u1.nRow = 2;
        if( sqlite3SrcItemAttachSubquery(pParse, p, pLeft, 0) ){
          pSubq = p->u4.pSubq;
          pSubq->addrFillSub = sqlite3VdbeCurrentAddr(v) + 1;
          pSubq->regReturn = ++pParse->nMem;
          sqlite3VdbeAddOp3(v, OP_InitCoroutine,
                            pSubq->regReturn, 0, pSubq->addrFillSub);
          sqlite3SelectDestInit(&dest, SRT_Coroutine, pSubq->regReturn);

          /* Allocate registers for the output of the co-routine. Do so so
          ** that there are two unused registers immediately before those
          ** used by the co-routine. This allows the code in sqlite3Insert()
          ** to use these registers directly, instead of copying the output
          ** of the co-routine to a separate array for processing.  */
          dest.iSdst = pParse->nMem + 3;
          dest.nSdst = pLeft->pEList->nExpr;
          pParse->nMem += 2 + dest.nSdst;

          pLeft->selFlags |= SF_MultiValue;
          sqlite3Select(pParse, pLeft, &dest);
          pSubq->regResult = dest.iSdst;
          assert( pParse->nErr || dest.iSdst>0 );
        }
        pLeft = pRet;
      }
    }else{
      p = &pLeft->pSrc->a[0];
      assert( !p->fg.isTabFunc && !p->fg.isIndexedBy );
      p->u1.nRow++;
    }

    if( pParse->nErr==0 ){
      Subquery *pSubq;
      assert( p!=0 );
      assert( p->fg.isSubquery );
      pSubq = p->u4.pSubq;
      assert( pSubq!=0 );
      assert( pSubq->pSelect!=0 );
      assert( pSubq->pSelect->pEList!=0 );
      if( pSubq->pSelect->pEList->nExpr!=pRow->nExpr ){
        sqlite3SelectWrongNumTermsError(pParse, pSubq->pSelect);
      }else{
        sqlite3ExprCodeExprList(pParse, pRow, pSubq->regResult, 0, 0);
        sqlite3VdbeAddOp1(pParse->pVdbe, OP_Yield, pSubq->regReturn);
      }
    }
    sqlite3ExprListDelete(pParse->db, pRow);
  }

  return pLeft;
}

    int rc;             /* Result code */

    if( pSelect->pSrc->nSrc==1
     && pSelect->pSrc->a[0].fg.viaCoroutine
     && pSelect->pPrior==0
    ){
      SrcItem *pItem = &pSelect->pSrc->a[0];
      Subquery *pSubq;
      assert( pItem->fg.isSubquery );
      pSubq = pItem->u4.pSubq;
      dest.iSDParm = pSubq->regReturn;
      regFromSelect = pSubq->regResult;
      assert( pSubq->pSelect!=0 );
      assert( pSubq->pSelect->pEList!=0 );
      nColumn = pSubq->pSelect->pEList->nExpr;
      ExplainQueryPlan((pParse, 0, "SCAN %S", pItem));
      if( bIdListInOrder && nColumn==pTab->nCol ){
        regData = regFromSelect;
        regRowid = regData - 1;
        regIns = regRowid - (IsVirtual(pTab) ? 1 : 0);
      }
    }else{

    if( pDest->iPKey>=0 ) onError = pDest->keyConf;
    if( onError==OE_Default ) onError = OE_Abort;
  }
  assert(pSelect->pSrc);   /* allocated even if there is no FROM clause */
  if( pSelect->pSrc->nSrc!=1 ){
    return 0;   /* FROM clause must have exactly one term */
  }
  if( pSelect->pSrc->a[0].fg.isSubquery ){
    return 0;   /* FROM clause cannot contain a subquery */
  }
  if( pSelect->pWhere ){
    return 0;   /* SELECT may not have a WHERE clause */
  }
  if( pSelect->pOrderBy ){
    return 0;   /* SELECT may not have an ORDER BY clause */

}

/*
** Mark a subquery result column as having been used.
*/
SQLITE_PRIVATE void sqlite3SrcItemColumnUsed(SrcItem *pItem, int iCol){
  assert( pItem!=0 );
  assert( (int)pItem->fg.isNestedFrom == IsNestedFrom(pItem) );
  if( pItem->fg.isNestedFrom ){
    ExprList *pResults;
    assert( pItem->fg.isSubquery );
    assert( pItem->u4.pSubq!=0 );
    assert( pItem->u4.pSubq->pSelect!=0 );
    pResults = pItem->u4.pSubq->pSelect->pEList;
    assert( pResults!=0 );
    assert( iCol>=0 && iCol<pResults->nExpr );
    pResults->a[iCol].fg.bUsed = 1;
  }
}

/*

  int iCol;            /* Index of column matching zCol */

  assert( iEnd<pSrc->nSrc );
  assert( iStart>=0 );
  assert( (piTab==0)==(piCol==0) );  /* Both or neither are NULL */

  for(i=iStart; i<=iEnd; i++){
    iCol = sqlite3ColumnIndex(pSrc->a[i].pSTab, zCol);
    if( iCol>=0
     && (bIgnoreHidden==0 || IsHiddenColumn(&pSrc->a[i].pSTab->aCol[iCol])==0)
    ){
      if( piTab ){
        sqlite3SrcItemColumnUsed(&pSrc->a[i], iCol);
        *piTab = i;
        *piCol = iCol;
      }
      return 1;

  SrcItem *pLeft;                 /* Left table being joined */
  SrcItem *pRight;                /* Right table being joined */

  pSrc = p->pSrc;
  pLeft = &pSrc->a[0];
  pRight = &pLeft[1];
  for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
    Table *pRightTab = pRight->pSTab;
    u32 joinType;

    if( NEVER(pLeft->pSTab==0 || pRightTab==0) ) continue;
    joinType = (pRight->fg.jointype & JT_OUTER)!=0 ? EP_OuterON : EP_InnerON;

    /* If this is a NATURAL join, synthesize an appropriate USING clause
    ** to specify which columns should be joined.
    */
    if( pRight->fg.jointype & JT_NATURAL ){
      IdList *pUsing = 0;

      Table *pTab = 0;            /* Table structure column is extracted from */
      Select *pS = 0;             /* Select the column is extracted from */
      int iCol = pExpr->iColumn;  /* Index of column in pTab */
      while( pNC && !pTab ){
        SrcList *pTabList = pNC->pSrcList;
        for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
        if( j<pTabList->nSrc ){
          pTab = pTabList->a[j].pSTab;
          if( pTabList->a[j].fg.isSubquery ){
            pS = pTabList->a[j].u4.pSubq->pSelect;
          }else{
            pS = 0;
          }
        }else{
          pNC = pNC->pNext;
        }
      }

      if( pTab==0 ){
        /* At one time, code such as "SELECT new.x" within a trigger would

    substExprList(pSubst, p->pGroupBy);
    substExprList(pSubst, p->pOrderBy);
    p->pHaving = substExpr(pSubst, p->pHaving);
    p->pWhere = substExpr(pSubst, p->pWhere);
    pSrc = p->pSrc;
    assert( pSrc!=0 );
    for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
      if( pItem->fg.isSubquery ){
        substSelect(pSubst, pItem->u4.pSubq->pSelect, 1);
      }
      if( pItem->fg.isTabFunc ){
        substExprList(pSubst, pItem->u1.pFuncArg);
      }
    }
  }while( doPrior && (p = p->pPrior)!=0 );
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */

  return WRC_Continue;
}
static void recomputeColumnsUsed(
  Select *pSelect,                 /* The complete SELECT statement */
  SrcItem *pSrcItem                /* Which FROM clause item to recompute */
){
  Walker w;
  if( NEVER(pSrcItem->pSTab==0) ) return;
  memset(&w, 0, sizeof(w));
  w.xExprCallback = recomputeColumnsUsedExpr;
  w.xSelectCallback = sqlite3SelectWalkNoop;
  w.u.pSrcItem = pSrcItem;
  pSrcItem->colUsed = 0;
  sqlite3WalkSelect(&w, pSelect);
}

    if( i!=iExcept ){
      Select *p;
      assert( pItem->iCursor < aCsrMap[0] );
      if( !pItem->fg.isRecursive || aCsrMap[pItem->iCursor+1]==0 ){
        aCsrMap[pItem->iCursor+1] = pParse->nTab++;
      }
      pItem->iCursor = aCsrMap[pItem->iCursor+1];
      if( pItem->fg.isSubquery ){
        for(p=pItem->u4.pSubq->pSelect; p; p=p->pPrior){
          srclistRenumberCursors(pParse, aCsrMap, p->pSrc, -1);
        }
      }
    }
  }
}

/*
** *piCursor is a cursor number.  Change it if it needs to be mapped.

  assert( p!=0 );
  assert( p->pPrior==0 );
  if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
  pSrc = p->pSrc;
  assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
  pSubitem = &pSrc->a[iFrom];
  iParent = pSubitem->iCursor;
  assert( pSubitem->fg.isSubquery );
  pSub = pSubitem->u4.pSubq->pSelect;
  assert( pSub!=0 );

#ifndef SQLITE_OMIT_WINDOWFUNC
  if( p->pWin || pSub->pWin ) return 0;                  /* Restriction (25) */
#endif

  pSubSrc = pSub->pSrc;

  **
  ** which is not at all the same thing.
  **
  ** See also tickets #306, #350, and #3300.
  */
  if( (pSubitem->fg.jointype & (JT_OUTER|JT_LTORJ))!=0 ){
    if( pSubSrc->nSrc>1                        /* (3a) */
     || IsVirtual(pSubSrc->a[0].pSTab)         /* (3b) */
     || (p->selFlags & SF_Distinct)!=0         /* (3d) */
     || (pSubitem->fg.jointype & JT_RIGHT)!=0  /* (26) */
    ){
      return 0;
    }
    isOuterJoin = 1;
  }

  /* Authorize the subquery */
  pParse->zAuthContext = pSubitem->zName;
  TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
  testcase( i==SQLITE_DENY );
  pParse->zAuthContext = zSavedAuthContext;

  /* Delete the transient structures associated with the subquery */

  if( ALWAYS(pSubitem->fg.isSubquery) ){
    pSub1 = sqlite3SubqueryDetach(db, pSubitem);
  }else{
    pSub1 = 0;
  }
  assert( pSubitem->fg.isSubquery==0 );
  assert( pSubitem->fg.fixedSchema==0 );
  sqlite3DbFree(db, pSubitem->zName);
  sqlite3DbFree(db, pSubitem->zAlias);

  pSubitem->zName = 0;
  pSubitem->zAlias = 0;

  assert( pSubitem->fg.isUsing!=0 || pSubitem->u3.pOn==0 );

  /* If the sub-query is a compound SELECT statement, then (by restrictions
  ** 17 and 18 above) it must be a UNION ALL and the parent query must
  ** be of the form:
  **
  **     SELECT <expr-list> FROM (<sub-query>) <where-clause>

  ** We call this the "compound-subquery flattening".
  */
  for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
    Select *pNew;
    ExprList *pOrderBy = p->pOrderBy;
    Expr *pLimit = p->pLimit;
    Select *pPrior = p->pPrior;
    Table *pItemTab = pSubitem->pSTab;
    pSubitem->pSTab = 0;
    p->pOrderBy = 0;
    p->pPrior = 0;
    p->pLimit = 0;
    pNew = sqlite3SelectDup(db, p, 0);
    p->pLimit = pLimit;
    p->pOrderBy = pOrderBy;
    p->op = TK_ALL;
    pSubitem->pSTab = pItemTab;
    if( pNew==0 ){
      p->pPrior = pPrior;
    }else{
      pNew->selId = ++pParse->nSelect;
      if( aCsrMap && ALWAYS(db->mallocFailed==0) ){
        renumberCursors(pParse, pNew, iFrom, aCsrMap);
      }
      pNew->pPrior = pPrior;
      if( pPrior ) pPrior->pNext = pNew;
      pNew->pNext = p;
      p->pPrior = pNew;
      TREETRACE(0x4,pParse,p,("compound-subquery flattener"
                              " creates %u as peer\n",pNew->selId));
    }
    assert( pSubitem->fg.isSubquery==0 );
  }
  sqlite3DbFree(db, aCsrMap);
  if( db->mallocFailed ){
    assert( pSubitem->fg.fixedSchema==0 );
    assert( pSubitem->fg.isSubquery==0 );
    assert( pSubitem->u4.zDatabase==0 );
    sqlite3SrcItemAttachSubquery(pParse, pSubitem, pSub1, 0);
    return 1;
  }

  /* Defer deleting the Table object associated with the
  ** subquery until code generation is
  ** complete, since there may still exist Expr.pTab entries that
  ** refer to the subquery even after flattening.  Ticket #3346.
  **
  ** pSubitem->pTab is always non-NULL by test restrictions and tests above.
  */
  if( ALWAYS(pSubitem->pSTab!=0) ){
    Table *pTabToDel = pSubitem->pSTab;
    if( pTabToDel->nTabRef==1 ){
      Parse *pToplevel = sqlite3ParseToplevel(pParse);
      sqlite3ParserAddCleanup(pToplevel, sqlite3DeleteTableGeneric, pTabToDel);
      testcase( pToplevel->earlyCleanup );
    }else{
      pTabToDel->nTabRef--;
    }
    pSubitem->pSTab = 0;
  }

  /* The following loop runs once for each term in a compound-subquery
  ** flattening (as described above).  If we are doing a different kind
  ** of flattening - a flattening other than a compound-subquery flattening -
  ** then this loop only runs once.
  **

    }

    /* Transfer the FROM clause terms from the subquery into the
    ** outer query.
    */
    for(i=0; i<nSubSrc; i++){
      SrcItem *pItem = &pSrc->a[i+iFrom];
      assert( pItem->fg.isTabFunc==0 );
      assert( pItem->fg.isSubquery
           || pItem->fg.fixedSchema
           || pItem->u4.zDatabase==0 );
      if( pItem->fg.isUsing ) sqlite3IdListDelete(db, pItem->u3.pUsing);
      *pItem = pSubSrc->a[i];
      pItem->fg.jointype |= ltorj;
      iNewParent = pSubSrc->a[i].iCursor;
      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
    }
    pSrc->a[iFrom].fg.jointype &= JT_LTORJ;
    pSrc->a[iFrom].fg.jointype |= jointype | ltorj;

  int nChng = 0;     /* Number of columns converted to NULL */
  Bitmask colUsed;   /* Columns that may not be NULLed out */

  assert( pItem!=0 );
  if( pItem->fg.isCorrelated || pItem->fg.isCte ){
    return 0;
  }
  assert( pItem->pSTab!=0 );
  pTab = pItem->pSTab;
  assert( pItem->fg.isSubquery );
  pSub = pItem->u4.pSubq->pSelect;
  assert( pSub->pEList->nExpr==pTab->nCol );
  for(pX=pSub; pX; pX=pX->pPrior){
    if( (pX->selFlags & (SF_Distinct|SF_Aggregate))!=0 ){
      testcase( pX->selFlags & SF_Distinct );
      testcase( pX->selFlags & SF_Aggregate );
      return 0;
    }

  Expr *pExpr;

  assert( !p->pGroupBy );

  if( p->pWhere
   || p->pEList->nExpr!=1
   || p->pSrc->nSrc!=1
   || p->pSrc->a[0].fg.isSubquery
   || pAggInfo->nFunc!=1
   || p->pHaving
  ){
    return 0;
  }
  pTab = p->pSrc->a[0].pSTab;
  assert( pTab!=0 );
  assert( !IsView(pTab) );
  if( !IsOrdinaryTable(pTab) ) return 0;
  pExpr = p->pEList->a[0].pExpr;
  assert( pExpr!=0 );
  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
  if( pExpr->pAggInfo!=pAggInfo ) return 0;

** If the source-list item passed as an argument was augmented with an
** INDEXED BY clause, then try to locate the specified index. If there
** was such a clause and the named index cannot be found, return
** SQLITE_ERROR and leave an error in pParse. Otherwise, populate
** pFrom->pIndex and return SQLITE_OK.
*/
SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *pParse, SrcItem *pFrom){
  Table *pTab = pFrom->pSTab;
  char *zIndexedBy = pFrom->u1.zIndexedBy;
  Index *pIdx;
  assert( pTab!=0 );
  assert( pFrom->fg.isIndexedBy!=0 );

  for(pIdx=pTab->pIndex;
      pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy);

  pParse = pWalker->pParse;
  db = pParse->db;
  pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
  if( pNew==0 ) return WRC_Abort;
  memset(&dummy, 0, sizeof(dummy));
  pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0);
  assert( pNewSrc!=0 || pParse->nErr );
  if( pParse->nErr ){
    sqlite3SrcListDelete(db, pNewSrc);
    return WRC_Abort;
  }
  *pNew = *p;
  p->pSrc = pNewSrc;
  p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ASTERISK, 0));
  p->op = TK_SELECT;
  p->pWhere = 0;
  pNew->pGroupBy = 0;
  pNew->pHaving = 0;

static struct Cte *searchWith(
  With *pWith,                    /* Current innermost WITH clause */
  SrcItem *pItem,                 /* FROM clause element to resolve */
  With **ppContext                /* OUT: WITH clause return value belongs to */
){
  const char *zName = pItem->zName;
  With *p;
  assert( pItem->fg.fixedSchema || pItem->u4.zDatabase==0 );
  assert( zName!=0 );
  for(p=pWith; p; p=p->pOuter){
    int i;
    for(i=0; i<p->nCte; i++){
      if( sqlite3StrICmp(zName, p->a[i].zName)==0 ){
        *ppContext = p;
        return &p->a[i];

  Parse *pParse,                  /* The parsing context */
  Walker *pWalker,                /* Current tree walker */
  SrcItem *pFrom                  /* The FROM clause term to check */
){
  Cte *pCte;               /* Matched CTE (or NULL if no match) */
  With *pWith;             /* The matching WITH */

  assert( pFrom->pSTab==0 );
  if( pParse->pWith==0 ){
    /* There are no WITH clauses in the stack.  No match is possible */
    return 0;
  }
  if( pParse->nErr ){
    /* Prior errors might have left pParse->pWith in a goofy state, so
    ** go no further. */
    return 0;
  }
  assert( pFrom->fg.hadSchema==0 || pFrom->fg.notCte!=0 );
  if( pFrom->fg.fixedSchema==0 && pFrom->u4.zDatabase!=0 ){
    /* The FROM term contains a schema qualifier (ex: main.t1) and so
    ** it cannot possibly be a CTE reference. */
    return 0;
  }
  if( pFrom->fg.notCte ){
    /* The FROM term is specifically excluded from matching a CTE.
    **   (1)  It is part of a trigger that used to have zDatabase but had

    ** In this case, proceed.  */
    if( pCte->zCteErr ){
      sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
      return 2;
    }
    if( cannotBeFunction(pParse, pFrom) ) return 2;

    assert( pFrom->pSTab==0 );
    pTab = sqlite3DbMallocZero(db, sizeof(Table));
    if( pTab==0 ) return 2;
    pCteUse = pCte->pUse;
    if( pCteUse==0 ){
      pCte->pUse = pCteUse = sqlite3DbMallocZero(db, sizeof(pCteUse[0]));
      if( pCteUse==0
       || sqlite3ParserAddCleanup(pParse,sqlite3DbFree,pCteUse)==0
      ){
        sqlite3DbFree(db, pTab);
        return 2;
      }
      pCteUse->eM10d = pCte->eM10d;
    }
    pFrom->pSTab = pTab;
    pTab->nTabRef = 1;
    pTab->zName = sqlite3DbStrDup(db, pCte->zName);
    pTab->iPKey = -1;
    pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
    pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
    sqlite3SrcItemAttachSubquery(pParse, pFrom, pCte->pSelect, 1);
    if( db->mallocFailed ) return 2;
    assert( pFrom->fg.isSubquery && pFrom->u4.pSubq );
    pSel = pFrom->u4.pSubq->pSelect;
    assert( pSel!=0 );
    pSel->selFlags |= SF_CopyCte;

    if( pFrom->fg.isIndexedBy ){
      sqlite3ErrorMsg(pParse, "no such index: \"%s\"", pFrom->u1.zIndexedBy);
      return 2;
    }
    assert( !pFrom->fg.isIndexedBy );
    pFrom->fg.isCte = 1;
    pFrom->u2.pCteUse = pCteUse;
    pCteUse->nUse++;

    /* Check if this is a recursive CTE. */
    pRecTerm = pSel;
    bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
    while( bMayRecursive && pRecTerm->op==pSel->op ){
      int i;
      SrcList *pSrc = pRecTerm->pSrc;
      assert( pRecTerm->pPrior!=0 );
      for(i=0; i<pSrc->nSrc; i++){
        SrcItem *pItem = &pSrc->a[i];
        if( pItem->zName!=0
         && !pItem->fg.hadSchema
         && ALWAYS( !pItem->fg.isSubquery )
         && (pItem->fg.fixedSchema || pItem->u4.zDatabase==0)
         && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
        ){
          pItem->pSTab = pTab;
          pTab->nTabRef++;
          pItem->fg.isRecursive = 1;
          if( pRecTerm->selFlags & SF_Recursive ){
            sqlite3ErrorMsg(pParse,
               "multiple references to recursive table: %s", pCte->zName
            );
            return 2;

** The SrcItem structure passed as the second argument represents a
** sub-query in the FROM clause of a SELECT statement. This function
** allocates and populates the SrcItem.pTab object. If successful,
** SQLITE_OK is returned. Otherwise, if an OOM error is encountered,
** SQLITE_NOMEM.
*/
SQLITE_PRIVATE int sqlite3ExpandSubquery(Parse *pParse, SrcItem *pFrom){
  Select *pSel;
  Table *pTab;

  assert( pFrom->fg.isSubquery );
  assert( pFrom->u4.pSubq!=0 );
  pSel = pFrom->u4.pSubq->pSelect;
  assert( pSel );
  pFrom->pSTab = pTab = sqlite3DbMallocZero(pParse->db, sizeof(Table));
  if( pTab==0 ) return SQLITE_NOMEM;
  pTab->nTabRef = 1;
  if( pFrom->zAlias ){
    pTab->zName = sqlite3DbStrDup(pParse->db, pFrom->zAlias);
  }else{
    pTab->zName = sqlite3MPrintf(pParse->db, "%!S", pFrom);
  }

  /* Look up every table named in the FROM clause of the select.  If
  ** an entry of the FROM clause is a subquery instead of a table or view,
  ** then create a transient table structure to describe the subquery.
  */
  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
    Table *pTab;
    assert( pFrom->fg.isRecursive==0 || pFrom->pSTab!=0 );
    if( pFrom->pSTab ) continue;
    assert( pFrom->fg.isRecursive==0 );
    if( pFrom->zName==0 ){
#ifndef SQLITE_OMIT_SUBQUERY
      Select *pSel;
      assert( pFrom->fg.isSubquery && pFrom->u4.pSubq!=0 );
      pSel = pFrom->u4.pSubq->pSelect;
      /* A sub-query in the FROM clause of a SELECT */
      assert( pSel!=0 );
      assert( pFrom->pSTab==0 );
      if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
      if( sqlite3ExpandSubquery(pParse, pFrom) ) return WRC_Abort;
#endif
#ifndef SQLITE_OMIT_CTE
    }else if( (rc = resolveFromTermToCte(pParse, pWalker, pFrom))!=0 ){
      if( rc>1 ) return WRC_Abort;
      pTab = pFrom->pSTab;
      assert( pTab!=0 );
#endif
    }else{
      /* An ordinary table or view name in the FROM clause */
      assert( pFrom->pSTab==0 );
      pFrom->pSTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
      if( pTab==0 ) return WRC_Abort;
      if( pTab->nTabRef>=0xffff ){
        sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
           pTab->zName);
        pFrom->pSTab = 0;
        return WRC_Abort;
      }
      pTab->nTabRef++;
      if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){
        return WRC_Abort;
      }
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
      if( !IsOrdinaryTable(pTab) ){
        i16 nCol;
        u8 eCodeOrig = pWalker->eCode;
        if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
        assert( pFrom->fg.isSubquery==0 );
        if( IsView(pTab) ){
          if( (db->flags & SQLITE_EnableView)==0
           && pTab->pSchema!=db->aDb[1].pSchema
          ){
            sqlite3ErrorMsg(pParse, "access to view \"%s\" prohibited",
              pTab->zName);
          }
          sqlite3SrcItemAttachSubquery(pParse, pFrom, pTab->u.view.pSelect, 1);
        }
#ifndef SQLITE_OMIT_VIRTUALTABLE
        else if( ALWAYS(IsVirtual(pTab))
         && pFrom->fg.fromDDL
         && ALWAYS(pTab->u.vtab.p!=0)
         && pTab->u.vtab.p->eVtabRisk > ((db->flags & SQLITE_TrustedSchema)!=0)
        ){
          sqlite3ErrorMsg(pParse, "unsafe use of virtual table \"%s\"",
                                  pTab->zName);
        }
        assert( SQLITE_VTABRISK_Normal==1 && SQLITE_VTABRISK_High==2 );
#endif
        nCol = pTab->nCol;
        pTab->nCol = -1;
        pWalker->eCode = 1;  /* Turn on Select.selId renumbering */
        if( pFrom->fg.isSubquery ){
          sqlite3WalkSelect(pWalker, pFrom->u4.pSubq->pSelect);
        }
        pWalker->eCode = eCodeOrig;
        pTab->nCol = nCol;
      }
#endif
    }

    /* Locate the index named by the INDEXED BY clause, if any. */

          iErrOfst = pE->pRight->w.iOfst;
        }else{
          assert( ExprUseWOfst(pE) );
          iErrOfst = pE->w.iOfst;
        }
        for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
          int nAdd;                    /* Number of cols including rowid */
          Table *pTab = pFrom->pSTab;  /* Table for this data source */
          ExprList *pNestedFrom;       /* Result-set of a nested FROM clause */
          char *zTabName;              /* AS name for this data source */
          const char *zSchemaName = 0; /* Schema name for this data source */
          int iDb;                     /* Schema index for this data src */
          IdList *pUsing;              /* USING clause for pFrom[1] */

          if( (zTabName = pFrom->zAlias)==0 ){
            zTabName = pTab->zName;
          }
          if( db->mallocFailed ) break;
          assert( (int)pFrom->fg.isNestedFrom == IsNestedFrom(pFrom) );
          if( pFrom->fg.isNestedFrom ){
            assert( pFrom->fg.isSubquery && pFrom->u4.pSubq );
            assert( pFrom->u4.pSubq->pSelect!=0 );
            pNestedFrom = pFrom->u4.pSubq->pSelect->pEList;
            assert( pNestedFrom!=0 );
            assert( pNestedFrom->nExpr==pTab->nCol );
            assert( VisibleRowid(pTab)==0 || ViewCanHaveRowid );
          }else{
            if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
              continue;
            }

  if( p->selFlags & SF_HasTypeInfo ) return;
  p->selFlags |= SF_HasTypeInfo;
  pParse = pWalker->pParse;
  assert( (p->selFlags & SF_Resolved) );
  pTabList = p->pSrc;
  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
    Table *pTab = pFrom->pSTab;
    assert( pTab!=0 );
    if( (pTab->tabFlags & TF_Ephemeral)!=0 && pFrom->fg.isSubquery ){
      /* A sub-query in the FROM clause of a SELECT */
      Select *pSel = pFrom->u4.pSubq->pSelect;

      sqlite3SubqueryColumnTypes(pParse, pTab, pSel, SQLITE_AFF_NONE);

    }
  }
}
#endif


/*

static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pF;
  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    ExprList *pList;
    assert( ExprUseXList(pF->pFExpr) );
    if( pParse->nErr ) return;
    pList = pF->pFExpr->x.pList;
    if( pF->iOBTab>=0 ){
      /* For an ORDER BY aggregate, calls to OP_AggStep were deferred.  Inputs
      ** were stored in emphermal table pF->iOBTab.  Here, we extract those
      ** inputs (in ORDER BY order) and make all calls to OP_AggStep
      ** before doing the OP_AggFinal call. */
      int iTop;        /* Start of loop for extracting columns */

      sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)nArg);
      sqlite3ReleaseTempRange(pParse, regAgg, nArg);
    }
    if( addrNext ){
      sqlite3VdbeResolveLabel(v, addrNext);
    }
    if( pParse->nErr ) return;
  }
  if( regHit==0 && pAggInfo->nAccumulator ){
    regHit = regAcc;
  }
  if( regHit ){
    addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pCExpr, AggInfoColumnReg(pAggInfo,i));
    if( pParse->nErr ) return;
  }

  pAggInfo->directMode = 0;
  if( addrHitTest ){
    sqlite3VdbeJumpHereOrPopInst(v, addrHitTest);
  }
}

*/
static SrcItem *isSelfJoinView(
  SrcList *pTabList,           /* Search for self-joins in this FROM clause */
  SrcItem *pThis,              /* Search for prior reference to this subquery */
  int iFirst, int iEnd        /* Range of FROM-clause entries to search. */
){
  SrcItem *pItem;
  Select *pSel;
  assert( pThis->fg.isSubquery );
  pSel = pThis->u4.pSubq->pSelect;
  assert( pSel!=0 );
  if( pSel->selFlags & SF_PushDown ) return 0;
  while( iFirst<iEnd ){
    Select *pS1;
    pItem = &pTabList->a[iFirst++];
    if( !pItem->fg.isSubquery ) continue;
    if( pItem->fg.viaCoroutine ) continue;
    if( pItem->zName==0 ) continue;
    assert( pItem->pSTab!=0 );
    assert( pThis->pSTab!=0 );
    if( pItem->pSTab->pSchema!=pThis->pSTab->pSchema ) continue;
    if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;
    pS1 = pItem->u4.pSubq->pSelect;
    if( pItem->pSTab->pSchema==0 && pSel->selId!=pS1->selId ){
      /* The query flattener left two different CTE tables with identical
      ** names in the same FROM clause. */
      continue;
    }
    if( pS1->selFlags & SF_PushDown ){
      /* The view was modified by some other optimization such as
      ** pushDownWhereTerms() */
      continue;
    }
    return pItem;
  }
  return 0;

** Return TRUE if the optimization is undertaken.
*/
static int countOfViewOptimization(Parse *pParse, Select *p){
  Select *pSub, *pPrior;
  Expr *pExpr;
  Expr *pCount;
  sqlite3 *db;
  SrcItem *pFrom;
  if( (p->selFlags & SF_Aggregate)==0 ) return 0;   /* This is an aggregate */
  if( p->pEList->nExpr!=1 ) return 0;               /* Single result column */
  if( p->pWhere ) return 0;
  if( p->pHaving ) return 0;
  if( p->pGroupBy ) return 0;
  if( p->pOrderBy ) return 0;
  pExpr = p->pEList->a[0].pExpr;
  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;        /* Result is an aggregate */
  assert( ExprUseUToken(pExpr) );
  if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0;  /* Is count() */
  assert( ExprUseXList(pExpr) );
  if( pExpr->x.pList!=0 ) return 0;                 /* Must be count(*) */
  if( p->pSrc->nSrc!=1 ) return 0;                  /* One table in FROM  */
  if( ExprHasProperty(pExpr, EP_WinFunc) ) return 0;/* Not a window function */
  pFrom = p->pSrc->a;
  if( pFrom->fg.isSubquery==0 ) return 0;    /* FROM is a subquery */
  pSub = pFrom->u4.pSubq->pSelect;
  if( pSub->pPrior==0 ) return 0;                   /* Must be a compound */
  if( pSub->selFlags & SF_CopyCte ) return 0;       /* Not a CTE */
  do{
    if( pSub->op!=TK_ALL && pSub->pPrior ) return 0;  /* Must be UNION ALL */
    if( pSub->pWhere ) return 0;                      /* No WHERE clause */
    if( pSub->pLimit ) return 0;                      /* No LIMIT clause */
    if( pSub->selFlags & SF_Aggregate ) return 0;     /* Not an aggregate */
    assert( pSub->pHaving==0 );  /* Due to the previous */
    pSub = pSub->pPrior;                              /* Repeat over compound */
  }while( pSub );

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

  db = pParse->db;
  pCount = pExpr;
  pExpr = 0;
  pSub = sqlite3SubqueryDetach(db, pFrom);

  sqlite3SrcListDelete(db, p->pSrc);
  p->pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*p->pSrc));
  while( pSub ){
    Expr *pTerm;
    pPrior = pSub->pPrior;
    pSub->pPrior = 0;
    pSub->pNext = 0;

** Otherwise return false.
*/
static int sameSrcAlias(SrcItem *p0, SrcList *pSrc){
  int i;
  for(i=0; i<pSrc->nSrc; i++){
    SrcItem *p1 = &pSrc->a[i];
    if( p1==p0 ) continue;
    if( p0->pSTab==p1->pSTab && 0==sqlite3_stricmp(p0->zAlias, p1->zAlias) ){
      return 1;
    }
    if( p1->fg.isSubquery
     && (p1->u4.pSubq->pSelect->selFlags & SF_NestedFrom)!=0
     && sameSrcAlias(p0, p1->u4.pSubq->pSelect->pSrc)
    ){
      return 1;
    }
  }
  return 0;
}

  }
  if( selFlags & SF_UpdateFrom ) return 0;                        /* (1c-iii) */
  while( 1 /*exit-by-break*/ ){
    if( pItem->fg.jointype & (JT_OUTER|JT_CROSS)  ) return 0;     /* (1c-ii) */
    if( i==0 ) break;
    i--;
    pItem--;
    if( pItem->fg.isSubquery ) return 0;                          /* (1c-i) */
  }
  return 1;
}

/*
** Generate byte-code for the SELECT statement given in the p argument.
**
** The results are returned according to the SelectDest structure.
** See comments in sqliteInt.h for further information.
**
** This routine returns the number of errors.  If any errors are
** encountered, then an appropriate error message is left in
** pParse->zErrMsg.
**
** This routine does NOT free the Select structure passed in.  The
** calling function needs to do that.
**
** This is a long function.  The following is an outline of the processing
** steps, with tags referencing various milestones:
**
**  *  Resolve names and similar preparation                tag-select-0100
**  *  Scan of the FROM clause                              tag-select-0200
**      +  OUTER JOIN strength reduction                      tag-select-0220
**      +  Sub-query ORDER BY removal                         tag-select-0230
**      +  Query flattening                                   tag-select-0240
**  *  Separate subroutine for compound-SELECT              tag-select-0300
**  *  WHERE-clause constant propagation                    tag-select-0330
**  *  Count()-of-VIEW optimization                         tag-select-0350
**  *  Scan of the FROM clause again                        tag-select-0400
**      +  Authorize unreferenced tables                      tag-select-0410
**      +  Predicate push-down optimization                   tag-select-0420
**      +  Omit unused subquery columns optimization          tag-select-0440
**      +  Generate code to implement subqueries              tag-select-0480
**         -  Co-routines                                       tag-select-0482
**         -  Reuse previously computed CTE                     tag-select-0484
**         -  REuse previously computed VIEW                    tag-select-0486
**         -  Materialize a VIEW or CTE                         tag-select-0488
**  *  DISTINCT ORDER BY -> GROUP BY optimization           tag-select-0500
**  *  Set up for ORDER BY                                  tag-select-0600
**  *  Create output table                                  tag-select-0630
**  *  Prepare registers for LIMIT                          tag-select-0650
**  *  Setup for DISTINCT                                   tag-select-0680
**  *  Generate code for non-aggregate and non-GROUP BY     tag-select-0700
**  *  Generate code for aggregate and/or GROUP BY          tag-select-0800
**      +  GROUP BY queries                                   tag-select-0810
**      +  non-GROUP BY queries                               tag-select-0820
**         -  Special case of count() w/o GROUP BY              tag-select-0821
**         -  General case of non-GROUP BY aggregates           tag-select-0822
**  *  Sort results, as needed                              tag-select-0900
**  *  Internal self-checks                                 tag-select-1000
*/
SQLITE_PRIVATE int sqlite3Select(
  Parse *pParse,         /* The parser context */
  Select *p,             /* The SELECT statement being coded. */
  SelectDest *pDest      /* What to do with the query results */
){
  int i, j;              /* Loop counters */

      sqlite3TreeViewLine(0, "In sqlite3Select() at %s:%d",
                           __FILE__, __LINE__);
    }
    sqlite3ShowSelect(p);
  }
#endif

  /* tag-select-0100 */
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo );
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
  if( IgnorableDistinct(pDest) ){
    assert(pDest->eDest==SRT_Exists     || pDest->eDest==SRT_Union ||
           pDest->eDest==SRT_Except     || pDest->eDest==SRT_Discard ||

  ** which is just confusing. To avoid this, we follow PG's lead and
  ** disallow it altogether.  */
  if( p->selFlags & SF_UFSrcCheck ){
    SrcItem *p0 = &p->pSrc->a[0];
    if( sameSrcAlias(p0, p->pSrc) ){
      sqlite3ErrorMsg(pParse,
          "target object/alias may not appear in FROM clause: %s",
          p0->zAlias ? p0->zAlias : p0->pSTab->zName
      );
      goto select_end;
    }

    /* Clear the SF_UFSrcCheck flag. The check has already been performed,
    ** and leaving this flag set can cause errors if a compound sub-query
    ** in p->pSrc is flattened into this query and this function called

  pTabList = p->pSrc;
  isAgg = (p->selFlags & SF_Aggregate)!=0;
  memset(&sSort, 0, sizeof(sSort));
  sSort.pOrderBy = p->pOrderBy;

  /* Try to do various optimizations (flattening subqueries, and strength
  ** reduction of join operators) in the FROM clause up into the main query
  ** tag-select-0200
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    SrcItem *pItem = &pTabList->a[i];
    Select *pSub = pItem->fg.isSubquery ? pItem->u4.pSubq->pSelect : 0;
    Table *pTab = pItem->pSTab;

    /* The expander should have already created transient Table objects
    ** even for FROM clause elements such as subqueries that do not correspond
    ** to a real table */
    assert( pTab!=0 );

    /* Try to simplify joins:
    **
    **      LEFT JOIN  ->  JOIN
    **     RIGHT JOIN  ->  JOIN
    **      FULL JOIN  ->  RIGHT JOIN
    **
    ** If terms of the i-th table are used in the WHERE clause in such a
    ** way that the i-th table cannot be the NULL row of a join, then
    ** perform the appropriate simplification. This is called
    ** "OUTER JOIN strength reduction" in the SQLite documentation.
    ** tag-select-0220
    */
    if( (pItem->fg.jointype & (JT_LEFT|JT_LTORJ))!=0
     && sqlite3ExprImpliesNonNullRow(p->pWhere, pItem->iCursor,
                                     pItem->fg.jointype & JT_LTORJ)
     && OptimizationEnabled(db, SQLITE_SimplifyJoin)
    ){
      if( pItem->fg.jointype & JT_LEFT ){

    ** is not a join.  But if the outer query is not a join, then the subquery
    ** will be implemented as a co-routine and there is no advantage to
    ** flattening in that case.
    */
    if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
    assert( pSub->pGroupBy==0 );

    /* tag-select-0230:
    ** If a FROM-clause subquery has an ORDER BY clause that is not
    ** really doing anything, then delete it now so that it does not
    ** interfere with query flattening.  See the discussion at
    ** https://sqlite.org/forum/forumpost/2d76f2bcf65d256a
    **
    ** Beware of these cases where the ORDER BY clause may not be safely
    ** omitted:
    **

     && (p->selFlags & SF_ComplexResult)!=0
     && (pTabList->nSrc==1
         || (pTabList->a[1].fg.jointype&(JT_OUTER|JT_CROSS))!=0)
    ){
      continue;
    }

    /* tag-select-0240 */
    if( flattenSubquery(pParse, p, i, isAgg) ){
      if( pParse->nErr ) goto select_end;
      /* This subquery can be absorbed into its parent. */
      i = -1;
    }
    pTabList = p->pSrc;
    if( db->mallocFailed ) goto select_end;
    if( !IgnorableOrderby(pDest) ){
      sSort.pOrderBy = p->pOrderBy;
    }
  }
#endif

#ifndef SQLITE_OMIT_COMPOUND_SELECT
  /* Handle compound SELECT statements using the separate multiSelect()
  ** procedure.  tag-select-0300
  */
  if( p->pPrior ){
    rc = multiSelect(pParse, p, pDest);
#if TREETRACE_ENABLED
    TREETRACE(0x400,pParse,p,("end compound-select processing\n"));
    if( (sqlite3TreeTrace & 0x400)!=0 && ExplainQueryPlanParent(pParse)==0 ){
      sqlite3TreeViewSelect(0, p, 0);
    }
#endif
    if( p->pNext==0 ) ExplainQueryPlanPop(pParse);
    return rc;
  }
#endif

  /* Do the WHERE-clause constant propagation optimization if this is
  ** a join.  No need to spend time on this operation for non-join queries
  ** as the equivalent optimization will be handled by query planner in
  ** sqlite3WhereBegin().  tag-select-0330
  */
  if( p->pWhere!=0
   && p->pWhere->op==TK_AND
   && OptimizationEnabled(db, SQLITE_PropagateConst)
   && propagateConstants(pParse, p)
  ){
#if TREETRACE_ENABLED
    if( sqlite3TreeTrace & 0x2000 ){
      TREETRACE(0x2000,pParse,p,("After constant propagation:\n"));
      sqlite3TreeViewSelect(0, p, 0);
    }
#endif
  }else{
    TREETRACE(0x2000,pParse,p,("Constant propagation not helpful\n"));
  }

  /* tag-select-0350 */
  if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)
   && countOfViewOptimization(pParse, p)
  ){
    if( db->mallocFailed ) goto select_end;
    pTabList = p->pSrc;
  }

  /* Loop over all terms in the FROM clause and do two things for each term:
  **
  **   (1) Authorize unreferenced tables
  **   (2) Generate code for all sub-queries
  **
  ** tag-select-0400
  */
  for(i=0; i<pTabList->nSrc; i++){
    SrcItem *pItem = &pTabList->a[i];
    SrcItem *pPrior;
    SelectDest dest;
    Subquery *pSubq;
    Select *pSub;
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
    const char *zSavedAuthContext;
#endif

    /* Authorized unreferenced tables.  tag-select-0410
    **
    ** Issue SQLITE_READ authorizations with a fake column name for any
    ** tables that are referenced but from which no values are extracted.
    ** Examples of where these kinds of null SQLITE_READ authorizations
    ** would occur:
    **
    **     SELECT count(*) FROM t1;   -- SQLITE_READ t1.""
    **     SELECT t1.* FROM t1, t2;   -- SQLITE_READ t2.""
    **
    ** The fake column name is an empty string.  It is possible for a table to
    ** have a column named by the empty string, in which case there is no way to
    ** distinguish between an unreferenced table and an actual reference to the
    ** "" column. The original design was for the fake column name to be a NULL,
    ** which would be unambiguous.  But legacy authorization callbacks might
    ** assume the column name is non-NULL and segfault.  The use of an empty
    ** string for the fake column name seems safer.
    */
    if( pItem->colUsed==0 && pItem->zName!=0 ){
      const char *zDb;
      if( pItem->fg.fixedSchema ){
        int iDb = sqlite3SchemaToIndex(pParse->db, pItem->u4.pSchema);
        zDb = db->aDb[iDb].zDbSName;
      }else if( pItem->fg.isSubquery ){
        zDb = 0;
      }else{
        zDb = pItem->u4.zDatabase;
      }
      sqlite3AuthCheck(pParse, SQLITE_READ, pItem->zName, "", zDb);
    }

#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
    /* Generate code for all sub-queries in the FROM clause
    */
    if( pItem->fg.isSubquery==0 ) continue;
    pSubq = pItem->u4.pSubq;
    assert( pSubq!=0 );
    pSub = pSubq->pSelect;

    /* The code for a subquery should only be generated once. */
    if( pSubq->addrFillSub!=0 ) continue;

    /* Increment Parse.nHeight by the height of the largest expression
    ** tree referred to by this, the parent select. The child select
    ** may contain expression trees of at most
    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
    ** more conservative than necessary, but much easier than enforcing
    ** an exact limit.
    */
    pParse->nHeight += sqlite3SelectExprHeight(p);

    /* Make copies of constant WHERE-clause terms in the outer query down
    ** inside the subquery.  This can help the subquery to run more efficiently.
    ** This is the "predicate push-down optimization".  tag-select-0420
    */
    if( OptimizationEnabled(db, SQLITE_PushDown)
     && (pItem->fg.isCte==0
         || (pItem->u2.pCteUse->eM10d!=M10d_Yes && pItem->u2.pCteUse->nUse<2))
     && pushDownWhereTerms(pParse, pSub, p->pWhere, pTabList, i)
    ){
#if TREETRACE_ENABLED
      if( sqlite3TreeTrace & 0x4000 ){
        TREETRACE(0x4000,pParse,p,
            ("After WHERE-clause push-down into subquery %d:\n", pSub->selId));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
      assert( pSubq->pSelect && (pSub->selFlags & SF_PushDown)!=0 );
    }else{
      TREETRACE(0x4000,pParse,p,("WHERE-lcause push-down not possible\n"));
    }

    /* Convert unused result columns of the subquery into simple NULL
    ** expressions, to avoid unneeded searching and computation.
    ** tag-select-0440
    */
    if( OptimizationEnabled(db, SQLITE_NullUnusedCols)
     && disableUnusedSubqueryResultColumns(pItem)
    ){
#if TREETRACE_ENABLED
      if( sqlite3TreeTrace & 0x4000 ){
        TREETRACE(0x4000,pParse,p,
            ("Change unused result columns to NULL for subquery %d:\n",
             pSub->selId));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
    }

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

    /* Generate byte-code to implement the subquery  tag-select-0480
    */
    if( fromClauseTermCanBeCoroutine(pParse, pTabList, i, p->selFlags) ){
      /* Implement a co-routine that will return a single row of the result
      ** set on each invocation.  tag-select-0482
      */
      int addrTop = sqlite3VdbeCurrentAddr(v)+1;

      pSubq->regReturn = ++pParse->nMem;
      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pSubq->regReturn, 0, addrTop);
      VdbeComment((v, "%!S", pItem));
      pSubq->addrFillSub = addrTop;
      sqlite3SelectDestInit(&dest, SRT_Coroutine, pSubq->regReturn);
      ExplainQueryPlan((pParse, 1, "CO-ROUTINE %!S", pItem));
      sqlite3Select(pParse, pSub, &dest);
      pItem->pSTab->nRowLogEst = pSub->nSelectRow;
      pItem->fg.viaCoroutine = 1;
      pSubq->regResult = dest.iSdst;
      sqlite3VdbeEndCoroutine(v, pSubq->regReturn);
      VdbeComment((v, "end %!S", pItem));
      sqlite3VdbeJumpHere(v, addrTop-1);
      sqlite3ClearTempRegCache(pParse);
    }else if( pItem->fg.isCte && pItem->u2.pCteUse->addrM9e>0 ){
      /* This is a CTE for which materialization code has already been
      ** generated.  Invoke the subroutine to compute the materialization,
      ** then make the pItem->iCursor be a copy of the ephemeral table that
      ** holds the result of the materialization. tag-select-0484 */
      CteUse *pCteUse = pItem->u2.pCteUse;
      sqlite3VdbeAddOp2(v, OP_Gosub, pCteUse->regRtn, pCteUse->addrM9e);
      if( pItem->iCursor!=pCteUse->iCur ){
        sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pCteUse->iCur);
        VdbeComment((v, "%!S", pItem));
      }
      pSub->nSelectRow = pCteUse->nRowEst;
    }else if( (pPrior = isSelfJoinView(pTabList, pItem, 0, i))!=0 ){
      /* This view has already been materialized by a prior entry in
      ** this same FROM clause.  Reuse it.  tag-select-0486 */
      Subquery *pPriorSubq;
      assert( pPrior->fg.isSubquery );
      pPriorSubq = pPrior->u4.pSubq;
      assert( pPriorSubq!=0 );
      if( pPriorSubq->addrFillSub ){
        sqlite3VdbeAddOp2(v, OP_Gosub, pPriorSubq->regReturn,
                                       pPriorSubq->addrFillSub);
      }
      sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor);
      pSub->nSelectRow = pPriorSubq->pSelect->nSelectRow;
    }else{
      /* Materialize the view.  If the view is not correlated, generate a
      ** subroutine to do the materialization so that subsequent uses of
      ** the same view can reuse the materialization.  tag-select-0488 */
      int topAddr;
      int onceAddr = 0;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
      int addrExplain;
#endif

      pSubq->regReturn = ++pParse->nMem;
      topAddr = sqlite3VdbeAddOp0(v, OP_Goto);
      pSubq->addrFillSub = topAddr+1;
      pItem->fg.isMaterialized = 1;
      if( pItem->fg.isCorrelated==0 ){
        /* If the subquery is not correlated and if we are not inside of
        ** a trigger, then we only need to compute the value of the subquery
        ** once. */
        onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
        VdbeComment((v, "materialize %!S", pItem));
      }else{
        VdbeNoopComment((v, "materialize %!S", pItem));
      }
      sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);

      ExplainQueryPlan2(addrExplain, (pParse, 1, "MATERIALIZE %!S", pItem));
      sqlite3Select(pParse, pSub, &dest);
      pItem->pSTab->nRowLogEst = pSub->nSelectRow;
      if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
      sqlite3VdbeAddOp2(v, OP_Return, pSubq->regReturn, topAddr+1);
      VdbeComment((v, "end %!S", pItem));
      sqlite3VdbeScanStatusRange(v, addrExplain, addrExplain, -1);
      sqlite3VdbeJumpHere(v, topAddr);
      sqlite3ClearTempRegCache(pParse);
      if( pItem->fg.isCte && pItem->fg.isCorrelated==0 ){
        CteUse *pCteUse = pItem->u2.pCteUse;
        pCteUse->addrM9e = pSubq->addrFillSub;
        pCteUse->regRtn = pSubq->regReturn;
        pCteUse->iCur = pItem->iCursor;
        pCteUse->nRowEst = pSub->nSelectRow;
      }
    }
    if( db->mallocFailed ) goto select_end;
    pParse->nHeight -= sqlite3SelectExprHeight(p);
    pParse->zAuthContext = zSavedAuthContext;

#if TREETRACE_ENABLED
  if( sqlite3TreeTrace & 0x8000 ){
    TREETRACE(0x8000,pParse,p,("After all FROM-clause analysis:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif

  /* tag-select-0500
  **
  ** If the query is DISTINCT with an ORDER BY but is not an aggregate, and
  ** if the select-list is the same as the ORDER BY list, then this query
  ** can be rewritten as a GROUP BY. In other words, this:
  **
  **     SELECT DISTINCT xyz FROM ... ORDER BY xyz
  **
  ** is transformed to:
  **

  /* If there is an ORDER BY clause, then create an ephemeral index to
  ** do the sorting.  But this sorting ephemeral index might end up
  ** being unused if the data can be extracted in pre-sorted order.
  ** If that is the case, then the OP_OpenEphemeral instruction will be
  ** changed to an OP_Noop once we figure out that the sorting index is
  ** not needed.  The sSort.addrSortIndex variable is used to facilitate
  ** that change.  tag-select-0600
  */
  if( sSort.pOrderBy ){
    KeyInfo *pKeyInfo;
    pKeyInfo = sqlite3KeyInfoFromExprList(
        pParse, sSort.pOrderBy, 0, pEList->nExpr);
    sSort.iECursor = pParse->nTab++;
    sSort.addrSortIndex =
      sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
          sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,
          (char*)pKeyInfo, P4_KEYINFO
      );
  }else{
    sSort.addrSortIndex = -1;
  }

  /* If the output is destined for a temporary table, open that table.
  ** tag-select-0630
  */
  if( pDest->eDest==SRT_EphemTab ){
    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iSDParm, pEList->nExpr);
    if( p->selFlags & SF_NestedFrom ){
      /* Delete or NULL-out result columns that will never be used */
      int ii;
      for(ii=pEList->nExpr-1; ii>0 && pEList->a[ii].fg.bUsed==0; ii--){
        sqlite3ExprDelete(db, pEList->a[ii].pExpr);
        sqlite3DbFree(db, pEList->a[ii].zEName);
        pEList->nExpr--;
      }
      for(ii=0; ii<pEList->nExpr; ii++){
        if( pEList->a[ii].fg.bUsed==0 ) pEList->a[ii].pExpr->op = TK_NULL;
      }
    }
  }

  /* Set the limiter.  tag-select-0650
  */
  iEnd = sqlite3VdbeMakeLabel(pParse);
  if( (p->selFlags & SF_FixedLimit)==0 ){
    p->nSelectRow = 320;  /* 4 billion rows */
  }
  if( p->pLimit ) computeLimitRegisters(pParse, p, iEnd);
  if( p->iLimit==0 && sSort.addrSortIndex>=0 ){
    sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);
    sSort.sortFlags |= SORTFLAG_UseSorter;
  }

  /* Open an ephemeral index to use for the distinct set. tag-select-0680
  */
  if( p->selFlags & SF_Distinct ){
    sDistinct.tabTnct = pParse->nTab++;
    sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
                       sDistinct.tabTnct, 0, 0,
                       (char*)sqlite3KeyInfoFromExprList(pParse, p->pEList,0,0),
                       P4_KEYINFO);
    sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
    sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
  }else{
    sDistinct.eTnctType = WHERE_DISTINCT_NOOP;
  }

  if( !isAgg && pGroupBy==0 ){
    /* No aggregate functions and no GROUP BY clause.  tag-select-0700 */
    u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0)
                   | (p->selFlags & SF_FixedLimit);
#ifndef SQLITE_OMIT_WINDOWFUNC
    Window *pWin = p->pWin;      /* Main window object (or NULL) */
    if( pWin ){
      sqlite3WindowCodeInit(pParse, p);
    }

      /* End the database scan loop.
      */
      TREETRACE(0x2,pParse,p,("WhereEnd\n"));
      sqlite3WhereEnd(pWInfo);
    }
  }else{
    /* This case is for when there exist aggregate functions or a GROUP BY
    ** clause or both.  tag-select-0800 */
    NameContext sNC;    /* Name context for processing aggregate information */
    int iAMem;          /* First Mem address for storing current GROUP BY */
    int iBMem;          /* First Mem address for previous GROUP BY */
    int iUseFlag;       /* Mem address holding flag indicating that at least
                        ** one row of the input to the aggregator has been
                        ** processed */
    int iAbortFlag;     /* Mem address which causes query abort if positive */

      }
      printAggInfo(pAggInfo);
    }
#endif


    /* Processing for aggregates with GROUP BY is very different and
    ** much more complex than aggregates without a GROUP BY.  tag-select-0810
    */
    if( pGroupBy ){
      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
      int addr1;          /* A-vs-B comparison jump */
      int addrOutputRow;  /* Start of subroutine that outputs a result row */
      int regOutputRow;   /* Return address register for output subroutine */
      int addrSetAbort;   /* Set the abort flag and return */

      if( distFlag!=0 && eDist!=WHERE_DISTINCT_NOOP ){
        struct AggInfo_func *pF = &pAggInfo->aFunc[0];
        fixDistinctOpenEph(pParse, eDist, pF->iDistinct, pF->iDistAddr);
      }
    } /* endif pGroupBy.  Begin aggregate queries without GROUP BY: */
    else {
      /* Aggregate functions without GROUP BY. tag-select-0820 */
      Table *pTab;
      if( (pTab = isSimpleCount(p, pAggInfo))!=0 ){
        /* tag-select-0821
        **
        ** If isSimpleCount() returns a pointer to a Table structure, then
        ** the SQL statement is of the form:
        **
        **   SELECT count(*) FROM <tbl>
        **
        ** where the Table structure returned represents table <tbl>.
        **
        ** This statement is so common that it is optimized specially. The

          sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
        }
        assignAggregateRegisters(pParse, pAggInfo);
        sqlite3VdbeAddOp2(v, OP_Count, iCsr, AggInfoFuncReg(pAggInfo,0));
        sqlite3VdbeAddOp1(v, OP_Close, iCsr);
        explainSimpleCount(pParse, pTab, pBest);
      }else{
        /* The general case of an aggregate query without GROUP BY
        ** tag-select-0822 */
        int regAcc = 0;           /* "populate accumulators" flag */
        ExprList *pDistinct = 0;
        u16 distFlag = 0;
        int eDist;

        /* If there are accumulator registers but no min() or max() functions
        ** without FILTER clauses, allocate register regAcc. Register regAcc

  } /* endif aggregate query */

  if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
    explainTempTable(pParse, "DISTINCT");
  }

  /* If there is an ORDER BY clause, then we need to sort the results
  ** and send them to the callback one by one.  tag-select-0900
  */
  if( sSort.pOrderBy ){
    assert( p->pEList==pEList );
    generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);
  }

  /* Jump here to skip this query

  ** successful coding of the SELECT.
  */
select_end:
  assert( db->mallocFailed==0 || db->mallocFailed==1 );
  assert( db->mallocFailed==0 || pParse->nErr!=0 );
  sqlite3ExprListDelete(db, pMinMaxOrderBy);
#ifdef SQLITE_DEBUG
  /* Internal self-checks.  tag-select-1000 */
  if( pAggInfo && !db->mallocFailed ){
#if TREETRACE_ENABLED
    if( sqlite3TreeTrace & 0x20 ){
      TREETRACE(0x20,pParse,p,("Finished with AggInfo\n"));
      printAggInfo(pAggInfo);
    }
#endif

  **    CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
  **                                                 ^^^^^^^^
  **
  ** To maintain backwards compatibility, ignore the database
  ** name on pTableName if we are reparsing out of the schema table
  */
  if( db->init.busy && iDb!=1 ){
    assert( pTableName->a[0].fg.fixedSchema==0 );
    assert( pTableName->a[0].fg.isSubquery==0 );
    sqlite3DbFree(db, pTableName->a[0].u4.zDatabase);
    pTableName->a[0].u4.zDatabase = 0;
  }

  /* If the trigger name was unqualified, and the table is a temp table,
  ** then set iDb to 1 to create the trigger in the temporary database.
  ** If sqlite3SrcListLookup() returns 0, indicating the table does not
  ** exist, the error is caught by the block below.
  */

  if( db->mallocFailed ) goto drop_trigger_cleanup;
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto drop_trigger_cleanup;
  }

  assert( pName->nSrc==1 );
  assert( pName->a[0].fg.fixedSchema==0 && pName->a[0].fg.isSubquery==0 );
  zDb = pName->a[0].u4.zDatabase;
  zName = pName->a[0].zName;
  assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
  for(i=OMIT_TEMPDB; i<db->nDb; i++){
    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
    if( zDb && sqlite3DbIsNamed(db, j, zDb)==0 ) continue;
    assert( sqlite3SchemaMutexHeld(db, j, 0) );
    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);

  pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
  assert( pSrc==0 || pSrc->nSrc==1 );
  assert( zName || pSrc==0 );
  if( pSrc ){
    Schema *pSchema = pStep->pTrig->pSchema;
    pSrc->a[0].zName = zName;
    if( pSchema!=db->aDb[1].pSchema ){
      assert( pSrc->a[0].fg.fixedSchema || pSrc->a[0].u4.zDatabase==0 );
      pSrc->a[0].u4.pSchema = pSchema;
      pSrc->a[0].fg.fixedSchema = 1;
    }
    if( pStep->pFrom ){
      SrcList *pDup = sqlite3SrcListDup(db, pStep->pFrom, 0);
      if( pDup && pDup->nSrc>1 && !IN_RENAME_OBJECT ){
        Select *pSubquery;
        Token as;
        pSubquery = sqlite3SelectNew(pParse,0,pDup,0,0,0,0,SF_NestedFrom,0);

static int sqlite3ReturningSubqueryCorrelated(Walker *pWalker, Select *pSelect){
  int i;
  SrcList *pSrc;
  assert( pSelect!=0 );
  pSrc = pSelect->pSrc;
  assert( pSrc!=0 );
  for(i=0; i<pSrc->nSrc; i++){
    if( pSrc->a[i].pSTab==pWalker->u.pTab ){
      testcase( pSelect->selFlags & SF_Correlated );
      pSelect->selFlags |= SF_Correlated;
      pWalker->eCode = 1;
      break;
    }
  }
  return WRC_Continue;

    return;
  }
  memset(&sSelect, 0, sizeof(sSelect));
  memset(&sFrom, 0, sizeof(sFrom));
  sSelect.pEList = sqlite3ExprListDup(db, pReturning->pReturnEL, 0);
  sSelect.pSrc = &sFrom;
  sFrom.nSrc = 1;
  sFrom.a[0].pSTab = pTab;
  sFrom.a[0].zName = pTab->zName; /* tag-20240424-1 */
  sFrom.a[0].iCursor = -1;
  sqlite3SelectPrep(pParse, &sSelect, 0);
  if( pParse->nErr==0 ){
    assert( db->mallocFailed==0 );
    sqlite3GenerateColumnNames(pParse, &sSelect);
  }

  SelectDest dest;
  Select *pSelect = 0;
  ExprList *pList = 0;
  ExprList *pGrp = 0;
  Expr *pLimit2 = 0;
  ExprList *pOrderBy2 = 0;
  sqlite3 *db = pParse->db;
  Table *pTab = pTabList->a[0].pSTab;
  SrcList *pSrc;
  Expr *pWhere2;
  int eDest;

#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
  if( pOrderBy && pLimit==0 ) {
    sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on UPDATE");

  pSrc = sqlite3SrcListDup(db, pTabList, 0);
  pWhere2 = sqlite3ExprDup(db, pWhere, 0);

  assert( pTabList->nSrc>1 );
  if( pSrc ){
    assert( pSrc->a[0].fg.notCte );
    pSrc->a[0].iCursor = -1;
    pSrc->a[0].pSTab->nTabRef--;
    pSrc->a[0].pSTab = 0;
  }
  if( pPk ){
    for(i=0; i<pPk->nKeyCol; i++){
      Expr *pNew = exprRowColumn(pParse, pPk->aiColumn[i]);
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
      if( pLimit ){
        pGrp = sqlite3ExprListAppend(pParse, pGrp, sqlite3ExprDup(db, pNew, 0));

  ExprList *pTarget;      /* The conflict-target clause */
  Expr *pTerm;            /* One term of the conflict-target clause */
  NameContext sNC;        /* Context for resolving symbolic names */
  Expr sCol[2];           /* Index column converted into an Expr */
  int nClause = 0;        /* Counter of ON CONFLICT clauses */

  assert( pTabList->nSrc==1 );
  assert( pTabList->a[0].pSTab!=0 );
  assert( pUpsert!=0 );
  assert( pUpsert->pUpsertTarget!=0 );

  /* Resolve all symbolic names in the conflict-target clause, which
  ** includes both the list of columns and the optional partial-index
  ** WHERE clause.
  */
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pParse;
  sNC.pSrcList = pTabList;
  for(; pUpsert && pUpsert->pUpsertTarget;
        pUpsert=pUpsert->pNextUpsert, nClause++){
    rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);
    if( rc ) return rc;
    rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);
    if( rc ) return rc;

    /* Check to see if the conflict target matches the rowid. */
    pTab = pTabList->a[0].pSTab;
    pTarget = pUpsert->pUpsertTarget;
    iCursor = pTabList->a[0].iCursor;
    if( HasRowid(pTab)
     && pTarget->nExpr==1
     && (pTerm = pTarget->a[0].pExpr)->op==TK_COLUMN
     && pTerm->iColumn==XN_ROWID
    ){

      Index *pIndex;         /* Index used, or NULL */
      ExprList *pOrderBy;    /* ORDER BY clause if this is really a subquery */
    } btree;
    struct {               /* Information for virtual tables */
      int idxNum;            /* Index number */
      u32 needFree : 1;      /* True if sqlite3_free(idxStr) is needed */
      u32 bOmitOffset : 1;   /* True to let virtual table handle offset */
      u32 bIdxNumHex : 1;    /* Show idxNum as hex in EXPLAIN QUERY PLAN */
      i8 isOrdered;          /* True if satisfies ORDER BY */
      u16 omitMask;          /* Terms that may be omitted */
      char *idxStr;          /* Index identifier string */
      u32 mHandleIn;         /* Terms to handle as IN(...) instead of == */
    } vtab;
  } u;
  u32 wsFlags;          /* WHERE_* flags describing the plan */

    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
      const char *zFmt = 0;
      Index *pIdx;

      assert( pLoop->u.btree.pIndex!=0 );
      pIdx = pLoop->u.btree.pIndex;
      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
      if( !HasRowid(pItem->pSTab) && IsPrimaryKeyIndex(pIdx) ){
        if( isSearch ){
          zFmt = "PRIMARY KEY";
        }
      }else if( flags & WHERE_PARTIALIDX ){
        zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
      }else if( flags & WHERE_AUTO_INDEX ){
        zFmt = "AUTOMATIC COVERING INDEX";

        assert( flags&WHERE_TOP_LIMIT);
        cRangeOp = '<';
      }
      sqlite3_str_appendf(&str, "%c?)", cRangeOp);
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
      sqlite3_str_appendall(&str, " VIRTUAL TABLE INDEX ");
      sqlite3_str_appendf(&str,
                  pLoop->u.vtab.bIdxNumHex ? "0x%x:%s" : "%d:%s",
                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
    }
#endif
    if( pItem->fg.jointype & JT_LEFT ){
      sqlite3_str_appendf(&str, " LEFT-JOIN");
    }
#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS

  char zBuf[100];               /* Initial space for EQP output string */

  sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
  str.printfFlags = SQLITE_PRINTF_INTERNAL;
  sqlite3_str_appendf(&str, "BLOOM FILTER ON %S (", pItem);
  pLoop = pLevel->pWLoop;
  if( pLoop->wsFlags & WHERE_IPK ){
    const Table *pTab = pItem->pSTab;
    if( pTab->iPKey>=0 ){
      sqlite3_str_appendf(&str, "%s=?", pTab->aCol[pTab->iPKey].zCnName);
    }else{
      sqlite3_str_appendf(&str, "rowid=?");
    }
  }else{
    for(i=pLoop->nSkip; i<pLoop->u.btree.nEq; i++){

      if( (wsFlags & (WHERE_MULTI_OR|WHERE_AUTO_INDEX))==0 ){
        sqlite3VdbeScanStatusRange(v, addrExplain, -1, pLvl->iTabCur);
      }
      if( wsFlags & WHERE_INDEXED ){
        sqlite3VdbeScanStatusRange(v, addrExplain, -1, pLvl->iIdxCur);
      }
    }else{
      int addr;
      assert( pSrclist->a[pLvl->iFrom].fg.isSubquery );
      addr = pSrclist->a[pLvl->iFrom].u4.pSubq->addrFillSub;
      VdbeOp *pOp = sqlite3VdbeGetOp(v, addr-1);
      assert( sqlite3VdbeDb(v)->mallocFailed || pOp->opcode==OP_InitCoroutine );
      assert( sqlite3VdbeDb(v)->mallocFailed || pOp->p2>addr );
      sqlite3VdbeScanStatusRange(v, addrExplain, addr, pOp->p2-1);
    }
  }
}

  pWC = &pWInfo->sWC;
  db = pParse->db;
  pLoop = pLevel->pWLoop;
  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
  iCur = pTabItem->iCursor;
  pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
  bRev = (pWInfo->revMask>>iLevel)&1;
  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",
                     iLevel, pTabItem->pSTab->zName));
#if WHERETRACE_ENABLED /* 0x4001 */
  if( sqlite3WhereTrace & 0x1 ){
    sqlite3DebugPrintf("Coding level %d of %d:  notReady=%llx  iFrom=%d\n",
       iLevel, pWInfo->nLevel, (u64)notReady, pLevel->iFrom);
    if( sqlite3WhereTrace & 0x1000 ){
      sqlite3WhereLoopPrint(pLoop, pWC);
    }

    if( pWInfo->a[j].iLeftJoin ) break;
    if( pWInfo->a[j].pRJ ) break;
  }
  addrHalt = pWInfo->a[j].addrBrk;

  /* Special case of a FROM clause subquery implemented as a co-routine */
  if( pTabItem->fg.viaCoroutine ){
    int regYield;
    Subquery *pSubq;
    assert( pTabItem->fg.isSubquery && pTabItem->u4.pSubq!=0 );
    pSubq = pTabItem->u4.pSubq;
    regYield = pSubq->regReturn;
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pSubq->addrFillSub);
    pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
    VdbeCoverage(v);
    VdbeComment((v, "next row of %s", pTabItem->pSTab->zName));
    pLevel->op = OP_Goto;
  }else

#ifndef SQLITE_OMIT_VIRTUALTABLE
  if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
    /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext
    **          to access the data.

    int regRowset = 0;                        /* Register for RowSet object */
    int regRowid = 0;                         /* Register holding rowid */
    int iLoopBody = sqlite3VdbeMakeLabel(pParse);/* Start of loop body */
    int iRetInit;                             /* Address of regReturn init */
    int untestedTerms = 0;             /* Some terms not completely tested */
    int ii;                            /* Loop counter */
    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
    Table *pTab = pTabItem->pSTab;

    pTerm = pLoop->aLTerm[0];
    assert( pTerm!=0 );
    assert( pTerm->eOperator & WO_OR );
    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
    pOrWc = &pTerm->u.pOrInfo->wc;
    pLevel->op = OP_Return;

    WhereRightJoin *pRJ = pLevel->pRJ;

    /* pTab is the right-hand table of the RIGHT JOIN.  Generate code that
    ** will record that the current row of that table has been matched at
    ** least once.  This is accomplished by storing the PK for the row in
    ** both the iMatch index and the regBloom Bloom filter.
    */
    pTab = pWInfo->pTabList->a[pLevel->iFrom].pSTab;
    if( HasRowid(pTab) ){
      r = sqlite3GetTempRange(pParse, 2);
      sqlite3ExprCodeGetColumnOfTable(v, pTab, pLevel->iTabCur, -1, r+1);
      nPk = 1;
    }else{
      int iPk;
      Index *pPk = sqlite3PrimaryKeyIndex(pTab);

  WhereInfo *pSubWInfo;
  WhereLoop *pLoop = pLevel->pWLoop;
  SrcItem *pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
  SrcList sFrom;
  Bitmask mAll = 0;
  int k;

  ExplainQueryPlan((pParse, 1, "RIGHT-JOIN %s", pTabItem->pSTab->zName));
  sqlite3VdbeNoJumpsOutsideSubrtn(v, pRJ->addrSubrtn, pRJ->endSubrtn,
                                  pRJ->regReturn);
  for(k=0; k<iLevel; k++){
    int iIdxCur;
    SrcItem *pRight;
    assert( pWInfo->a[k].pWLoop->iTab == pWInfo->a[k].iFrom );
    pRight = &pWInfo->pTabList->a[pWInfo->a[k].iFrom];
    mAll |= pWInfo->a[k].pWLoop->maskSelf;
    if( pRight->fg.viaCoroutine ){
      Subquery *pSubq;
      assert( pRight->fg.isSubquery && pRight->u4.pSubq!=0 );
      pSubq = pRight->u4.pSubq;
      assert( pSubq->pSelect!=0 && pSubq->pSelect->pEList!=0 );
      sqlite3VdbeAddOp3(
          v, OP_Null, 0, pSubq->regResult,
          pSubq->regResult + pSubq->pSelect->pEList->nExpr-1
      );
    }
    sqlite3VdbeAddOp1(v, OP_NullRow, pWInfo->a[k].iTabCur);
    iIdxCur = pWInfo->a[k].iIdxCur;
    if( iIdxCur ){
      sqlite3VdbeAddOp1(v, OP_NullRow, iIdxCur);
    }

                                WHERE_RIGHT_JOIN, 0);
  if( pSubWInfo ){
    int iCur = pLevel->iTabCur;
    int r = ++pParse->nMem;
    int nPk;
    int jmp;
    int addrCont = sqlite3WhereContinueLabel(pSubWInfo);
    Table *pTab = pTabItem->pSTab;
    if( HasRowid(pTab) ){
      sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, -1, r);
      nPk = 1;
    }else{
      int iPk;
      Index *pPk = sqlite3PrimaryKeyIndex(pTab);
      nPk = pPk->nKeyCol;

    assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
  }else if( op==TK_STRING ){
    assert( !ExprHasProperty(pRight, EP_IntValue) );
     z = (u8*)pRight->u.zToken;
  }
  if( z ){

    /* Count the number of prefix characters prior to the first wildcard.
    ** If the underlying database has a UTF16LE encoding, then only consider
    ** ASCII characters.  Note that the encoding of z[] is UTF8 - we are
    ** dealing with only UTF8 here in this code, but the database engine
    ** itself might be processing content using a different encoding. */
    cnt = 0;
    while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
      cnt++;
      if( c==wc[3] && z[cnt]!=0 ){
        cnt++;
      }else if( c>=0x80 && ENC(db)==SQLITE_UTF16LE ){
         cnt--;
         break;
      }
    }

    /* The optimization is possible only if (1) the pattern does not begin
    ** with a wildcard and if (2) the non-wildcard prefix does not end with
    ** an (illegal 0xff) character, or (3) the pattern does not consist of
    ** a single escape character. The second condition is necessary so
    ** that we can increment the prefix key to find an upper bound for the
    ** range search. The third is because the caller assumes that the pattern
    ** consists of at least one character after all escapes have been
    ** removed.  */
    if( (cnt>1 || (cnt>0 && z[0]!=wc[3])) && 255!=(u8)z[cnt-1] ){
      Expr *pPrefix;

      /* A "complete" match if the pattern ends with "*" or "%" */
      *pisComplete = c==wc[0] && z[cnt+1]==0 && ENC(db)!=SQLITE_UTF16LE;

      /* Get the pattern prefix.  Remove all escapes from the prefix. */
      pPrefix = sqlite3Expr(db, TK_STRING, (char*)z);
      if( pPrefix ){
        int iFrom, iTo;
        char *zNew;
        assert( !ExprHasProperty(pPrefix, EP_IntValue) );

    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);
    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);
    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);
    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);
    if( ALWAYS(pSrc!=0) ){
      int i;
      for(i=0; i<pSrc->nSrc; i++){
        if( pSrc->a[i].fg.isSubquery ){
          mask |= exprSelectUsage(pMaskSet, pSrc->a[i].u4.pSubq->pSelect);
        }
        if( pSrc->a[i].fg.isUsing==0 ){
          mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].u3.pOn);
        }
        if( pSrc->a[i].fg.isTabFunc ){
          mask |= sqlite3WhereExprListUsage(pMaskSet, pSrc->a[i].u1.pFuncArg);
        }
      }

  int j                  /* Start looking with the j-th pFrom entry */
){
  Index *pIdx;
  int i;
  int iCur;
  do{
    iCur = pFrom->a[j].iCursor;
    for(pIdx=pFrom->a[j].pSTab->pIndex; pIdx; pIdx=pIdx->pNext){
      if( pIdx->aColExpr==0 ) continue;
      for(i=0; i<pIdx->nKeyCol; i++){
        if( pIdx->aiColumn[i]!=XN_EXPR ) continue;
        assert( pIdx->bHasExpr );
        if( sqlite3ExprCompareSkip(pExpr,pIdx->aColExpr->a[i].pExpr,iCur)==0
         && !sqlite3ExprIsConstant(0,pIdx->aColExpr->a[i].pExpr)
        ){

    aiCurCol[0] = pExpr->iTable;
    aiCurCol[1] = pExpr->iColumn;
    return 1;
  }

  for(i=0; i<pFrom->nSrc; i++){
    Index *pIdx;
    for(pIdx=pFrom->a[i].pSTab->pIndex; pIdx; pIdx=pIdx->pNext){
      if( pIdx->aColExpr ){
        return exprMightBeIndexed2(pFrom,aiCurCol,pExpr,i);
      }
    }
  }
  return 0;
}

** exist only so that they may be passed to the xBestIndex method of the
** single virtual table in the FROM clause of the SELECT.
*/
SQLITE_PRIVATE void SQLITE_NOINLINE sqlite3WhereAddLimit(WhereClause *pWC, Select *p){
  assert( p!=0 && p->pLimit!=0 );                 /* 1 -- checked by caller */
  if( p->pGroupBy==0
   && (p->selFlags & (SF_Distinct|SF_Aggregate))==0             /* 2 */
   && (p->pSrc->nSrc==1 && IsVirtual(p->pSrc->a[0].pSTab))      /* 3 */
  ){
    ExprList *pOrderBy = p->pOrderBy;
    int iCsr = p->pSrc->a[0].iCursor;
    int ii;

    /* Check condition (4). Return early if it is not met. */
    for(ii=0; ii<pWC->nTerm; ii++){

){
  Table *pTab;
  int j, k;
  ExprList *pArgs;
  Expr *pColRef;
  Expr *pTerm;
  if( pItem->fg.isTabFunc==0 ) return;
  pTab = pItem->pSTab;
  assert( pTab!=0 );
  pArgs = pItem->u1.pFuncArg;
  if( pArgs==0 ) return;
  for(j=k=0; j<pArgs->nExpr; j++){
    Expr *pRhs;
    u32 joinType;
    while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}

  int iBase;

  /* If there is more than one table or sub-select in the FROM clause of
  ** this query, then it will not be possible to show that the DISTINCT
  ** clause is redundant. */
  if( pTabList->nSrc!=1 ) return 0;
  iBase = pTabList->a[0].iCursor;
  pTab = pTabList->a[0].pSTab;

  /* If any of the expressions is an IPK column on table iBase, then return
  ** true. Note: The (p->iTable==iBase) part of this test may be false if the
  ** current SELECT is a correlated sub-query.
  */
  for(i=0; i<pDistinct->nExpr; i++){
    Expr *p = sqlite3ExprSkipCollateAndLikely(pDistinct->a[i].pExpr);

  ){
    return 0;  /* See https://sqlite.org/forum/forumpost/51e6959f61 */
  }
  if( (pTerm->prereqRight & notReady)!=0 ) return 0;
  assert( (pTerm->eOperator & (WO_OR|WO_AND))==0 );
  leftCol = pTerm->u.x.leftColumn;
  if( leftCol<0 ) return 0;
  aff = pSrc->pSTab->aCol[leftCol].affinity;
  if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
  testcase( pTerm->pExpr->op==TK_IS );
  return columnIsGoodIndexCandidate(pSrc->pSTab, leftCol);
}
#endif


#ifndef SQLITE_OMIT_AUTOMATIC_INDEX

#ifdef SQLITE_ENABLE_STMT_SCANSTATUS

  addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  /* Count the number of columns that will be added to the index
  ** and used to match WHERE clause constraints */
  nKeyCol = 0;
  pTabList = pWC->pWInfo->pTabList;
  pSrc = &pTabList->a[pLevel->iFrom];
  pTable = pSrc->pSTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    Expr *pExpr = pTerm->pExpr;
    /* Make the automatic index a partial index if there are terms in the
    ** WHERE clause (or the ON clause of a LEFT join) that constrain which

    pLevel->regFilter = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Blob, 10000, pLevel->regFilter);
  }

  /* Fill the automatic index with content */
  assert( pSrc == &pWC->pWInfo->pTabList->a[pLevel->iFrom] );
  if( pSrc->fg.viaCoroutine ){
    int regYield;
    Subquery *pSubq;
    assert( pSrc->fg.isSubquery );
    pSubq = pSrc->u4.pSubq;
    assert( pSubq!=0 );
    regYield = pSubq->regReturn;
    addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pSubq->addrFillSub);
    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
    VdbeCoverage(v);
    VdbeComment((v, "next row of %s", pSrc->pSTab->zName));
  }else{
    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
  }
  if( pPartial ){
    iContinue = sqlite3VdbeMakeLabel(pParse);
    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
    pLoop->wsFlags |= WHERE_PARTIALIDX;

                         regBase, pLoop->u.btree.nEq);
  }
  sqlite3VdbeScanStatusCounters(v, addrExp, addrExp, sqlite3VdbeCurrentAddr(v));
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
  if( pSrc->fg.viaCoroutine ){
    assert( pSrc->fg.isSubquery && pSrc->u4.pSubq!=0 );
    sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
    testcase( pParse->db->mallocFailed );
    assert( pLevel->iIdxCur>0 );
    translateColumnToCopy(pParse, addrTop, pLevel->iTabCur,
                          pSrc->u4.pSubq->regResult, pLevel->iIdxCur);
    sqlite3VdbeGoto(v, addrTop);
    pSrc->fg.viaCoroutine = 0;
  }else{
    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
    sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
  }
  sqlite3VdbeJumpHere(v, addrTop);

    ** testing complicated.  By basing the blob size on the value in the
    ** sqlite_stat1 table, testing is much easier.
    */
    pTabList = pWInfo->pTabList;
    iSrc = pLevel->iFrom;
    pItem = &pTabList->a[iSrc];
    assert( pItem!=0 );
    pTab = pItem->pSTab;
    assert( pTab!=0 );
    sz = sqlite3LogEstToInt(pTab->nRowLogEst);
    if( sz<10000 ){
      sz = 10000;
    }else if( sz>10000000 ){
      sz = 10000000;
    }

      sqlite3ReleaseTempReg(pParse, r1);
    }else{
      Index *pIdx = pLoop->u.btree.pIndex;
      int n = pLoop->u.btree.nEq;
      int r1 = sqlite3GetTempRange(pParse, n);
      int jj;
      for(jj=0; jj<n; jj++){
        assert( pIdx->pTable==pItem->pSTab );
        sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iCur, jj, r1+jj);
      }
      sqlite3VdbeAddOp4Int(v, OP_FilterAdd, pLevel->regFilter, 0, r1, n);
      sqlite3ReleaseTempRange(pParse, r1, n);
    }
    sqlite3VdbeResolveLabel(v, addrCont);
    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1);

  u16 mNoOmit = 0;
  const Table *pTab;
  int eDistinct = 0;
  ExprList *pOrderBy = pWInfo->pOrderBy;
  WhereClause *p;

  assert( pSrc!=0 );
  pTab = pSrc->pSTab;
  assert( pTab!=0 );
  assert( IsVirtual(pTab) );

  /* Find all WHERE clause constraints referring to this virtual table.
  ** Mark each term with the TERM_OK flag.  Set nTerm to the number of
  ** terms found.
  */

**     1.002.001         t2.t2xy              2 f 010241 N 2 cost 0,56,31
*/
SQLITE_PRIVATE void sqlite3WhereLoopPrint(const WhereLoop *p, const WhereClause *pWC){
  if( pWC ){
    WhereInfo *pWInfo = pWC->pWInfo;
    int nb = 1+(pWInfo->pTabList->nSrc+3)/4;
    SrcItem *pItem = pWInfo->pTabList->a + p->iTab;
    Table *pTab = pItem->pSTab;
    Bitmask mAll = (((Bitmask)1)<<(nb*4)) - 1;
    sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
                       p->iTab, nb, p->maskSelf, nb, p->prereq & mAll);
    sqlite3DebugPrintf(" %12s",
                       pItem->zAlias ? pItem->zAlias : pTab->zName);
  }else{
    sqlite3DebugPrintf("%c%2d.%03llx.%03llx %c%d",

    /* Set rCostIdx to the estimated cost of visiting selected rows in the
    ** index.  The estimate is the sum of two values:
    **   1.  The cost of doing one search-by-key to find the first matching
    **       entry
    **   2.  Stepping forward in the index pNew->nOut times to find all
    **       additional matching entries.
    */
    assert( pSrc->pSTab->szTabRow>0 );
    if( pProbe->idxType==SQLITE_IDXTYPE_IPK ){
      /* The pProbe->szIdxRow is low for an IPK table since the interior
      ** pages are small.  Thus szIdxRow gives a good estimate of seek cost.
      ** But the leaf pages are full-size, so pProbe->szIdxRow would badly
      ** under-estimate the scanning cost. */
      rCostIdx = pNew->nOut + 16;
    }else{
      rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pSTab->szTabRow;
    }
    rCostIdx = sqlite3LogEstAdd(rLogSize, rCostIdx);

    /* Estimate the cost of running the loop.  If all data is coming
    ** from the index, then this is just the cost of doing the index
    ** lookup and scan.  But if some data is coming out of the main table,
    ** we also have to add in the cost of doing pNew->nOut searches to

  WhereClause *pWC;           /* The parsed WHERE clause */
  Table *pTab;                /* Table being queried */

  pNew = pBuilder->pNew;
  pWInfo = pBuilder->pWInfo;
  pTabList = pWInfo->pTabList;
  pSrc = pTabList->a + pNew->iTab;
  pTab = pSrc->pSTab;
  pWC = pBuilder->pWC;
  assert( !IsVirtual(pSrc->pSTab) );

  if( pSrc->fg.isIndexedBy ){
    assert( pSrc->fg.isCte==0 );
    /* An INDEXED BY clause specifies a particular index to use */
    pProbe = pSrc->u2.pIBIndex;
  }else if( !HasRowid(pTab) ){
    pProbe = pTab->pIndex;

    sPk.aiRowLogEst = aiRowEstPk;
    sPk.onError = OE_Replace;
    sPk.pTable = pTab;
    sPk.szIdxRow = 3;  /* TUNING: Interior rows of IPK table are very small */
    sPk.idxType = SQLITE_IDXTYPE_IPK;
    aiRowEstPk[0] = pTab->nRowLogEst;
    aiRowEstPk[1] = 0;
    pFirst = pSrc->pSTab->pIndex;
    if( pSrc->fg.notIndexed==0 ){
      /* The real indices of the table are only considered if the
      ** NOT INDEXED qualifier is omitted from the FROM clause */
      sPk.pNext = pFirst;
    }
    pProbe = &sPk;
  }

#ifdef SQLITE_ENABLE_STAT4
      pNew->rRun = rSize + 16 - 2*((pTab->tabFlags & TF_HasStat4)!=0);
#else
      pNew->rRun = rSize + 16;
#endif
      ApplyCostMultiplier(pNew->rRun, pTab->costMult);
      whereLoopOutputAdjust(pWC, pNew, rSize);
      if( pSrc->fg.isSubquery ){
        if( pSrc->fg.viaCoroutine ) pNew->wsFlags |= WHERE_COROUTINE;
        pNew->u.btree.pOrderBy = pSrc->u4.pSubq->pSelect->pOrderBy;
      }
      rc = whereLoopInsert(pBuilder, pNew);
      pNew->nOut = rSize;
      if( rc ) break;
    }else{
      Bitmask m;
      if( pProbe->isCovering ){

  pIdxInfo->orderByConsumed = 0;
  pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
  pIdxInfo->estimatedRows = 25;
  pIdxInfo->idxFlags = 0;
  pHidden->mHandleIn = 0;

  /* Invoke the virtual table xBestIndex() method */
  rc = vtabBestIndex(pParse, pSrc->pSTab, pIdxInfo);
  if( rc ){
    if( rc==SQLITE_CONSTRAINT ){
      /* If the xBestIndex method returns SQLITE_CONSTRAINT, that means
      ** that the particular combination of parameters provided is unusable.
      ** Make no entries in the loop table.
      */
      WHERETRACE(0xffffffff, ("  ^^^^--- non-viable plan rejected!\n"));

      int j = pIdxCons->iTermOffset;
      if( iTerm>=nConstraint
       || j<0
       || (pTerm = termFromWhereClause(pWC, j))==0
       || pNew->aLTerm[iTerm]!=0
       || pIdxCons->usable==0
      ){
        sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pSTab->zName);
        freeIdxStr(pIdxInfo);
        return SQLITE_ERROR;
      }
      testcase( iTerm==nConstraint-1 );
      testcase( j==0 );
      testcase( j==pWC->nTerm-1 );
      pNew->prereq |= pTerm->prereqRight;

  }

  pNew->nLTerm = mxTerm+1;
  for(i=0; i<=mxTerm; i++){
    if( pNew->aLTerm[i]==0 ){
      /* The non-zero argvIdx values must be contiguous.  Raise an
      ** error if they are not */
      sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pSTab->zName);
      freeIdxStr(pIdxInfo);
      return SQLITE_ERROR;
    }
  }
  assert( pNew->nLTerm<=pNew->nLSlot );
  pNew->u.vtab.idxNum = pIdxInfo->idxNum;
  pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
  pIdxInfo->needToFreeIdxStr = 0;
  pNew->u.vtab.idxStr = pIdxInfo->idxStr;
  pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
      pIdxInfo->nOrderBy : 0);
  pNew->u.vtab.bIdxNumHex = (pIdxInfo->idxFlags&SQLITE_INDEX_SCAN_HEX)!=0;
  pNew->rSetup = 0;
  pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
  pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);

  /* Set the WHERE_ONEROW flag if the xBestIndex() method indicated
  ** that the scan will visit at most one row. Clear it otherwise. */
  if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){

  assert( (mPrereq & mUnusable)==0 );
  pWInfo = pBuilder->pWInfo;
  pParse = pWInfo->pParse;
  pWC = pBuilder->pWC;
  pNew = pBuilder->pNew;
  pSrc = &pWInfo->pTabList->a[pNew->iTab];
  assert( IsVirtual(pSrc->pSTab) );
  p = allocateIndexInfo(pWInfo, pWC, mUnusable, pSrc, &mNoOmit);
  if( p==0 ) return SQLITE_NOMEM_BKPT;
  pNew->rSetup = 0;
  pNew->wsFlags = WHERE_VIRTUALTABLE;
  pNew->nLTerm = 0;
  pNew->u.vtab.needFree = 0;
  nConstraint = p->nConstraint;
  if( whereLoopResize(pParse->db, pNew, nConstraint) ){
    freeIndexInfo(pParse->db, p);
    return SQLITE_NOMEM_BKPT;
  }

  /* First call xBestIndex() with all constraints usable. */
  WHERETRACE(0x800, ("BEGIN %s.addVirtual()\n", pSrc->pSTab->zName));
  WHERETRACE(0x800, ("  VirtualOne: all usable\n"));
  rc = whereLoopAddVirtualOne(
      pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn, &bRetry
  );
  if( bRetry ){
    assert( rc==SQLITE_OK );
    rc = whereLoopAddVirtualOne(

      WHERETRACE(0x800, ("  VirtualOne: all disabled and w/o IN\n"));
      rc = whereLoopAddVirtualOne(
          pBuilder, mPrereq, mPrereq, WO_IN, p, mNoOmit, &bIn, 0);
    }
  }

  freeIndexInfo(pParse->db, p);
  WHERETRACE(0x800, ("END %s.addVirtual(), rc=%d\n", pSrc->pSTab->zName, rc));
  return rc;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** Add WhereLoop entries to handle OR terms.  This works for either
** btrees or virtual tables.

        WHERETRACE(0x400, ("OR-term %d of %p has %d subterms:\n",
                   (int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));
        if( sqlite3WhereTrace & 0x20000 ){
          sqlite3WhereClausePrint(sSubBuild.pWC);
        }
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
        if( IsVirtual(pItem->pSTab) ){
          rc = whereLoopAddVirtual(&sSubBuild, mPrereq, mUnusable);
        }else
#endif
        {
          rc = whereLoopAddBtree(&sSubBuild, mPrereq);
        }
        if( rc==SQLITE_OK ){

      if( pItem->fg.jointype & JT_LTORJ ) hasRightJoin = 1;
      mPrereq |= mPrior;
      bFirstPastRJ = (pItem->fg.jointype & JT_RIGHT)!=0;
    }else if( !hasRightJoin ){
      mPrereq = 0;
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pItem->pSTab) ){
      SrcItem *p;
      for(p=&pItem[1]; p<pEnd; p++){
        if( mUnusable || (p->fg.jointype & (JT_OUTER|JT_CROSS)) ){
          mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);
        }
      }
      rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);

      }
      if( nDep<=3 ) continue;
      rDelta = 15*(nDep-3);
#ifdef WHERETRACE_ENABLED /* 0x4 */
      if( sqlite3WhereTrace&0x4 ){
         SrcItem *pItem = pWInfo->pTabList->a + iLoop;
         sqlite3DebugPrintf("Fact-table %s: %d dimensions, cost reduced %d\n",
             pItem->zAlias ? pItem->zAlias : pItem->pSTab->zName,
             nDep, rDelta);
      }
#endif
      if( pWInfo->nOutStarDelta==0 ){
        for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
          pWLoop->rStarDelta = 0;
        }

  Index *pIdx;
  WhereScan scan;

  pWInfo = pBuilder->pWInfo;
  if( pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE ) return 0;
  assert( pWInfo->pTabList->nSrc>=1 );
  pItem = pWInfo->pTabList->a;
  pTab = pItem->pSTab;
  if( IsVirtual(pTab) ) return 0;
  if( pItem->fg.isIndexedBy || pItem->fg.notIndexed ){
    testcase( pItem->fg.isIndexedBy );
    testcase( pItem->fg.notIndexed );
    return 0;
  }
  iCur = pItem->iCursor;

  assert( pWInfo->nLevel>=2 );
  assert( OptimizationEnabled(pWInfo->pParse->db, SQLITE_BloomFilter) );
  for(i=0; i<pWInfo->nLevel; i++){
    WhereLoop *pLoop = pWInfo->a[i].pWLoop;
    const unsigned int reqFlags = (WHERE_SELFCULL|WHERE_COLUMN_EQ);
    SrcItem *pItem = &pWInfo->pTabList->a[pLoop->iTab];
    Table *pTab = pItem->pSTab;
    if( (pTab->tabFlags & TF_HasStat1)==0 ) break;
    pTab->tabFlags |= TF_MaybeReanalyze;
    if( i>=1
     && (pLoop->wsFlags & reqFlags)==reqFlags
     /* vvvvvv--- Always the case if WHERE_COLUMN_EQ is defined */
     && ALWAYS((pLoop->wsFlags & (WHERE_IPK|WHERE_INDEXED))!=0)
    ){

*/
static SQLITE_NOINLINE void whereReverseScanOrder(WhereInfo *pWInfo){
  int ii;
  for(ii=0; ii<pWInfo->pTabList->nSrc; ii++){
    SrcItem *pItem = &pWInfo->pTabList->a[ii];
    if( !pItem->fg.isCte
     || pItem->u2.pCteUse->eM10d!=M10d_Yes
     || NEVER(pItem->fg.isSubquery==0)
     || pItem->u4.pSubq->pSelect->pOrderBy==0
    ){
      pWInfo->revMask |= MASKBIT(ii);
    }
  }
}

/*

  ** use a one-pass approach, and this is not set accurately for scans
  ** that use the OR optimization.
  */
  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
    int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
    int bOnerow = (wsFlags & WHERE_ONEROW)!=0;
    assert( !(wsFlags&WHERE_VIRTUALTABLE) || IsVirtual(pTabList->a[0].pSTab) );
    if( bOnerow || (
        0!=(wctrlFlags & WHERE_ONEPASS_MULTIROW)
     && !IsVirtual(pTabList->a[0].pSTab)
     && (0==(wsFlags & WHERE_MULTI_OR) || (wctrlFlags & WHERE_DUPLICATES_OK))
     && OptimizationEnabled(db, SQLITE_OnePass)
    )){
      pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
      if( HasRowid(pTabList->a[0].pSTab) && (wsFlags & WHERE_IDX_ONLY) ){
        if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){
          bFordelete = OPFLAG_FORDELETE;
        }
        pWInfo->a[0].pWLoop->wsFlags = (wsFlags & ~WHERE_IDX_ONLY);
      }
    }
  }

  /* Open all tables in the pTabList and any indices selected for
  ** searching those tables.
  */
  for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
    Table *pTab;     /* Table to open */
    int iDb;         /* Index of database containing table/index */
    SrcItem *pTabItem;

    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pSTab;
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    pLoop = pLevel->pWLoop;
    if( (pTab->tabFlags & TF_Ephemeral)!=0 || IsView(pTab) ){
      /* Do nothing */
    }else
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){

       && (wctrlFlags & WHERE_OR_SUBCLAUSE)!=0
      ){
        /* This is one term of an OR-optimization using the PRIMARY KEY of a
        ** WITHOUT ROWID table.  No need for a separate index */
        iIndexCur = pLevel->iTabCur;
        op = 0;
      }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
        Index *pJ = pTabItem->pSTab->pIndex;
        iIndexCur = iAuxArg;
        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
        while( ALWAYS(pJ) && pJ!=pIx ){
          iIndexCur++;
          pJ = pJ->pNext;
        }
        op = OP_OpenWrite;

    ){
      WhereRightJoin *pRJ = pLevel->pRJ;
      pRJ->iMatch = pParse->nTab++;
      pRJ->regBloom = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Blob, 65536, pRJ->regBloom);
      pRJ->regReturn = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, pRJ->regReturn);
      assert( pTab==pTabItem->pSTab );
      if( HasRowid(pTab) ){
        KeyInfo *pInfo;
        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pRJ->iMatch, 1);
        pInfo = sqlite3KeyInfoAlloc(pParse->db, 1, 0);
        if( pInfo ){
          pInfo->aColl[0] = 0;
          pInfo->aSortFlags[0] = 0;

    int wsFlags;
    SrcItem *pSrc;
    if( pParse->nErr ) goto whereBeginError;
    pLevel = &pWInfo->a[ii];
    wsFlags = pLevel->pWLoop->wsFlags;
    pSrc = &pTabList->a[pLevel->iFrom];
    if( pSrc->fg.isMaterialized ){
      Subquery *pSubq;
      int iOnce = 0;
      assert( pSrc->fg.isSubquery );
      pSubq = pSrc->u4.pSubq;
      if( pSrc->fg.isCorrelated==0 ){
        iOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
      }else{
        iOnce = 0;
      }
      sqlite3VdbeAddOp2(v, OP_Gosub, pSubq->regReturn, pSubq->addrFillSub);
      VdbeComment((v, "materialize %!S", pSrc));
      if( iOnce )  sqlite3VdbeJumpHere(v, iOnce);

    }
    assert( pTabList == pWInfo->pTabList );
    if( (wsFlags & (WHERE_AUTO_INDEX|WHERE_BLOOMFILTER))!=0 ){
      if( (wsFlags & WHERE_AUTO_INDEX)!=0 ){
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
        constructAutomaticIndex(pParse, &pWInfo->sWC, notReady, pLevel);
#endif

      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
      assert( (ws & WHERE_IDX_ONLY)==0 || (ws & WHERE_INDEXED)!=0 );
      if( (ws & WHERE_IDX_ONLY)==0 ){
        SrcItem *pSrc = &pTabList->a[pLevel->iFrom];
        assert( pLevel->iTabCur==pSrc->iCursor );
        if( pSrc->fg.viaCoroutine ){
          int m, n;
          assert( pSrc->fg.isSubquery );
          n = pSrc->u4.pSubq->regResult;
          assert( pSrc->pSTab!=0 );
          m = pSrc->pSTab->nCol;
          sqlite3VdbeAddOp3(v, OP_Null, 0, n, n+m-1);
        }
        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iTabCur);
      }
      if( (ws & WHERE_INDEXED)
       || ((ws & WHERE_MULTI_OR) && pLevel->u.pCoveringIdx)
      ){

        sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);
      }else{
        sqlite3VdbeGoto(v, pLevel->addrFirst);
      }
      sqlite3VdbeJumpHere(v, addr);
    }
    VdbeModuleComment((v, "End WHERE-loop%d: %s", i,
                     pWInfo->pTabList->a[pLevel->iFrom].pSTab->zName));
  }

  assert( pWInfo->nLevel<=pTabList->nSrc );
  for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
    int k, last;
    VdbeOp *pOp, *pLastOp;
    Index *pIdx = 0;
    SrcItem *pTabItem = &pTabList->a[pLevel->iFrom];
    Table *pTab = pTabItem->pSTab;
    assert( pTab!=0 );
    pLoop = pLevel->pWLoop;

    /* Do RIGHT JOIN processing.  Generate code that will output the
    ** unmatched rows of the right operand of the RIGHT JOIN with
    ** all of the columns of the left operand set to NULL.
    */
    if( pLevel->pRJ ){
      sqlite3WhereRightJoinLoop(pWInfo, i, pLevel);
      continue;
    }

    /* For a co-routine, change all OP_Column references to the table of
    ** the co-routine into OP_Copy of result contained in a register.
    ** OP_Rowid becomes OP_Null.
    */
    if( pTabItem->fg.viaCoroutine ){
      testcase( pParse->db->mallocFailed );
      assert( pTabItem->fg.isSubquery );
      assert( pTabItem->u4.pSubq->regResult>=0 );
      translateColumnToCopy(pParse, pLevel->addrBody, pLevel->iTabCur,
                            pTabItem->u4.pSubq->regResult, 0);
      continue;
    }

    /* If this scan uses an index, make VDBE code substitutions to read data
    ** from the index instead of from the table where possible.  In some cases
    ** this optimization prevents the table from ever being read, which can
    ** yield a significant performance boost.

    TREETRACE(0x40,pParse,pSub,
       ("New window-function subquery in FROM clause of (%u/%p)\n",
       p->selId, p));
    p->pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
    assert( pSub!=0 || p->pSrc==0 ); /* Due to db->mallocFailed test inside
                                     ** of sqlite3DbMallocRawNN() called from
                                     ** sqlite3SrcListAppend() */
    if( p->pSrc==0 ){
      sqlite3SelectDelete(db, pSub);
    }else if( sqlite3SrcItemAttachSubquery(pParse, &p->pSrc->a[0], pSub, 0) ){
      Table *pTab2;

      p->pSrc->a[0].fg.isCorrelated = 1;
      sqlite3SrcListAssignCursors(pParse, p->pSrc);
      pSub->selFlags |= SF_Expanded|SF_OrderByReqd;
      pTab2 = sqlite3ResultSetOfSelect(pParse, pSub, SQLITE_AFF_NONE);
      pSub->selFlags |= (selFlags & SF_Aggregate);
      if( pTab2==0 ){
        /* Might actually be some other kind of error, but in that case
        ** pParse->nErr will be set, so if SQLITE_NOMEM is set, we will get
        ** the correct error message regardless. */
        rc = SQLITE_NOMEM;
      }else{
        memcpy(pTab, pTab2, sizeof(Table));
        pTab->tabFlags |= TF_Ephemeral;
        p->pSrc->a[0].pSTab = pTab;
        pTab = pTab2;
        memset(&w, 0, sizeof(w));
        w.xExprCallback = sqlite3WindowExtraAggFuncDepth;
        w.xSelectCallback = sqlite3WalkerDepthIncrease;
        w.xSelectCallback2 = sqlite3WalkerDepthDecrease;
        sqlite3WalkSelect(&w, pSub);
      }


    }
    if( db->mallocFailed ) rc = SQLITE_NOMEM;

    /* Defer deleting the temporary table pTab because if an error occurred,
    ** there could still be references to that table embedded in the
    ** result-set or ORDER BY clause of the SELECT statement p.  */
    sqlite3ParserAddCleanup(pParse, sqlite3DbFree, pTab);

/*
** This is called by code in select.c before it calls sqlite3WhereBegin()
** to begin iterating through the sub-query results. It is used to allocate
** and initialize registers and cursors used by sqlite3WindowCodeStep().
*/
SQLITE_PRIVATE void sqlite3WindowCodeInit(Parse *pParse, Select *pSelect){
  Window *pWin;
  int nEphExpr;
  Window *pMWin;
  Vdbe *v;

  assert( pSelect->pSrc->a[0].fg.isSubquery );
  nEphExpr = pSelect->pSrc->a[0].u4.pSubq->pSelect->pEList->nExpr;
  pMWin = pSelect->pWin;
  v = sqlite3GetVdbe(pParse);

  sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pMWin->iEphCsr, nEphExpr);
  sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->iEphCsr+1, pMWin->iEphCsr);
  sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->iEphCsr+2, pMWin->iEphCsr);
  sqlite3VdbeAddOp2(v, OP_OpenDup, pMWin->iEphCsr+3, pMWin->iEphCsr);

  /* Allocate registers to use for PARTITION BY values, if any. Initialize

  int addrGosub                   /* OP_Gosub here to return each row */
){
  Window *pMWin = p->pWin;
  ExprList *pOrderBy = pMWin->pOrderBy;
  Vdbe *v = sqlite3GetVdbe(pParse);
  int csrWrite;                   /* Cursor used to write to eph. table */
  int csrInput = p->pSrc->a[0].iCursor;     /* Cursor of sub-select */
  int nInput = p->pSrc->a[0].pSTab->nCol;   /* Number of cols returned by sub */
  int iInput;                               /* To iterate through sub cols */
  int addrNe;                     /* Address of OP_Ne */
  int addrGosubFlush = 0;         /* Address of OP_Gosub to flush: */
  int addrInteger = 0;            /* Address of OP_Integer */
  int addrEmpty;                  /* Address of OP_Rewind in flush: */
  int regNew;                     /* Array of registers holding new input row */
  int regRecord;                  /* regNew array in record form */

    if( yymsp[-5].minor.yy203==0 && yymsp[-1].minor.yy0.n==0 && yymsp[0].minor.yy269.pOn==0 && yymsp[0].minor.yy269.pUsing==0 ){
      yymsp[-5].minor.yy203 = yymsp[-3].minor.yy203;
    }else if( ALWAYS(yymsp[-3].minor.yy203!=0) && yymsp[-3].minor.yy203->nSrc==1 ){
      yymsp[-5].minor.yy203 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-5].minor.yy203,0,0,&yymsp[-1].minor.yy0,0,&yymsp[0].minor.yy269);
      if( yymsp[-5].minor.yy203 ){
        SrcItem *pNew = &yymsp[-5].minor.yy203->a[yymsp[-5].minor.yy203->nSrc-1];
        SrcItem *pOld = yymsp[-3].minor.yy203->a;
        assert( pOld->fg.fixedSchema==0 );
        pNew->zName = pOld->zName;
        assert( pOld->fg.fixedSchema==0 );
        if( pOld->fg.isSubquery ){
          pNew->fg.isSubquery = 1;
          pNew->u4.pSubq = pOld->u4.pSubq;
          pOld->u4.pSubq = 0;
          pOld->fg.isSubquery = 0;
          assert( pNew->u4.pSubq!=0 && pNew->u4.pSubq->pSelect!=0 );
          if( (pNew->u4.pSubq->pSelect->selFlags & SF_NestedFrom)!=0 ){
            pNew->fg.isNestedFrom = 1;
          }
        }else{
          pNew->u4.zDatabase = pOld->u4.zDatabase;
          pOld->u4.zDatabase = 0;
        }
        if( pOld->fg.isTabFunc ){
          pNew->u1.pFuncArg = pOld->u1.pFuncArg;
          pOld->u1.pFuncArg = 0;
          pOld->fg.isTabFunc = 0;
          pNew->fg.isTabFunc = 1;
        }
        pOld->zName = 0;

      }
      sqlite3SrcListDelete(pParse->db, yymsp[-3].minor.yy203);
    }else{
      Select *pSubquery;
      sqlite3SrcListShiftJoinType(pParse,yymsp[-3].minor.yy203);
      pSubquery = sqlite3SelectNew(pParse,0,yymsp[-3].minor.yy203,0,0,0,0,SF_NestedFrom,0);
      yymsp[-5].minor.yy203 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-5].minor.yy203,0,0,&yymsp[-1].minor.yy0,pSubquery,&yymsp[0].minor.yy269);

    ** is obtained in every case.
    */
    case SQLITE_TESTCTRL_OPTIMIZATIONS: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      db->dbOptFlags = va_arg(ap, u32);
      break;
    }

    /*  sqlite3_test_control(SQLITE_TESTCTRL_GETOPT, sqlite3 *db, int *N)
    **
    ** Write the current optimization settings into *N.  A zero bit means that
    ** the optimization is on, and a 1 bit means that the optimization is off.
    */
    case SQLITE_TESTCTRL_GETOPT: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      int *pN = va_arg(ap, int*);
      *pN = db->dbOptFlags;
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, onoff, xAlt);
    **
    ** If parameter onoff is 1, subsequent calls to localtime() fail.
    ** If 2, then invoke xAlt() instead of localtime().  If 0, normal
    ** processing.
    **

     && pIdxInfo->aOrderBy[1].iColumn==1
     && pIdxInfo->aOrderBy[1].desc==0
     )
  ){
    pIdxInfo->orderByConsumed = 1;
    pIdxInfo->idxNum |= 0x08;
  }
  pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_HEX;

  return SQLITE_OK;
}

/*
** Open a new DBSTAT cursor.
*/

**
**   The output text is not a copy of the document text that was tokenized.
**   It is the output of the tokenizer module. For tokendata=1 tables, this
**   includes any embedded 0x00 and trailing data.
**
**   This API can be quite slow if used with an FTS5 table created with the
**   "detail=none" or "detail=column" option.
**
** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
**   If parameter iCol is less than zero, or greater than or equal to the
**   number of columns in the table, SQLITE_RANGE is returned.
**
**   Otherwise, this function attempts to retrieve the locale associated
**   with column iCol of the current row. Usually, there is no associated
**   locale, and output parameters (*pzLocale) and (*pnLocale) are set
**   to NULL and 0, respectively. However, if the fts5_locale() function
**   was used to associate a locale with the value when it was inserted
**   into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
**   buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
**   is set to the size in bytes of the buffer, not including the
**   nul-terminator.
**
**   If successful, SQLITE_OK is returned. Or, if an error occurs, an
**   SQLite error code is returned. The final value of the output parameters
**   is undefined in this case.
**
** xTokenize_v2:
**   Tokenize text using the tokenizer belonging to the FTS5 table. This
**   API is the same as the xTokenize() API, except that it allows a tokenizer
**   locale to be specified.
*/
struct Fts5ExtensionApi {
  int iVersion;                   /* Currently always set to 4 */

  void *(*xUserData)(Fts5Context*);

  int (*xColumnCount)(Fts5Context*);
  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

  /* Below this point are iVersion>=3 only */
  int (*xQueryToken)(Fts5Context*,
      int iPhrase, int iToken,
      const char **ppToken, int *pnToken
  );
  int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);

  /* Below this point are iVersion>=4 only */
  int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
  int (*xTokenize_v2)(Fts5Context*,
    const char *pText, int nText,      /* Text to tokenize */
    const char *pLocale, int nLocale,  /* Locale to pass to tokenizer */
    void *pCtx,                        /* Context passed to xToken() */
    int (*xToken)(void*, int, const char*, int, int, int)       /* Callback */
  );
};

/*
** CUSTOM AUXILIARY FUNCTIONS
*************************************************************************/

/*************************************************************************
** CUSTOM TOKENIZERS
**
** Applications may also register custom tokenizer types. A tokenizer
** is registered by providing fts5 with a populated instance of the
** following structure. All structure methods must be defined, setting
**
** any member of the fts5_tokenizer struct to NULL leads to undefined
** behaviour. The structure methods are expected to function as follows:
**
** xCreate:
**   This function is used to allocate and initialize a tokenizer instance.
**   A tokenizer instance is required to actually tokenize text.
**
**   The first argument passed to this function is a copy of the (void*)
**   pointer provided by the application when the fts5_tokenizer_v2 object
**   was registered with FTS5 (the third argument to xCreateTokenizer()).
**   The second and third arguments are an array of nul-terminated strings
**   containing the tokenizer arguments, if any, specified following the
**   tokenizer name as part of the CREATE VIRTUAL TABLE statement used
**   to create the FTS5 table.
**
**   The final argument is an output variable. If successful, (*ppOut)

**
** xTokenize:
**   This function is expected to tokenize the nText byte string indicated
**   by argument pText. pText may or may not be nul-terminated. The first
**   argument passed to this function is a pointer to an Fts5Tokenizer object
**   returned by an earlier call to xCreate().
**
**   The third argument indicates the reason that FTS5 is requesting
**   tokenization of the supplied text. This is always one of the following
**   four values:
**
**   <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
**            or removed from the FTS table. The tokenizer is being invoked to
**            determine the set of tokens to add to (or delete from) the
**            FTS index.

**            returned by the tokenizer will be treated as a token prefix.
**
**       <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
**            satisfy an fts5_api.xTokenize() request made by an auxiliary
**            function. Or an fts5_api.xColumnSize() request made by the same
**            on a columnsize=0 database.
**   </ul>
**
**   The sixth and seventh arguments passed to xTokenize() - pLocale and
**   nLocale - are a pointer to a buffer containing the locale to use for
**   tokenization (e.g. "en_US") and its size in bytes, respectively. The
**   pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
**   which case nLocale is always 0) to indicate that the tokenizer should
**   use its default locale.
**
**   For each token in the input string, the supplied callback xToken() must
**   be invoked. The first argument to it should be a copy of the pointer
**   passed as the second argument to xTokenize(). The third and fourth
**   arguments are a pointer to a buffer containing the token text, and the
**   size of the token in bytes. The 4th and 5th arguments are the byte offsets
**   of the first byte of and first byte immediately following the text from

**   If an xToken() callback returns any value other than SQLITE_OK, then
**   the tokenization should be abandoned and the xTokenize() method should
**   immediately return a copy of the xToken() return value. Or, if the
**   input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
**   if an error occurs with the xTokenize() implementation itself, it
**   may abandon the tokenization and return any error code other than
**   SQLITE_OK or SQLITE_DONE.
**
**   If the tokenizer is registered using an fts5_tokenizer_v2 object,
**   then the xTokenize() method has two additional arguments - pLocale
**   and nLocale. These specify the locale that the tokenizer should use
**   for the current request. If pLocale and nLocale are both 0, then the
**   tokenizer should use its default locale. Otherwise, pLocale points to
**   an nLocale byte buffer containing the name of the locale to use as utf-8
**   text. pLocale is not nul-terminated.
**
** FTS5_TOKENIZER
**
** There is also an fts5_tokenizer object. This is an older version of
** fts5_tokenizer_v2. It is similar except that:
**
**  <ul>
**    <li> There is no "iVersion" field, and
**    <li> The xTokenize() method does not take a locale argument.
**  </ul>
**
** fts5_tokenizer tokenizers should be registered with the xCreateTokenizer()
** function, instead of xCreateTokenizer_v2(). Tokenizers implementations
** registered using either API may be retrieved using both xFindTokenizer()
** and xFindTokenizer_v2().
**
** SYNONYM SUPPORT
**
**   Custom tokenizers may also support synonyms. Consider a case in which a
**   user wishes to query for a phrase such as "first place". Using the
**   built-in tokenizers, the FTS5 query 'first + place' will match instances
**   of "first place" within the document set, but not alternative forms

**
**   When using methods (2) or (3), it is important that the tokenizer only
**   provide synonyms when tokenizing document text (method (3)) or query
**   text (method (2)), not both. Doing so will not cause any errors, but is
**   inefficient.
*/
typedef struct Fts5Tokenizer Fts5Tokenizer;
typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
struct fts5_tokenizer_v2 {
  int iVersion;             /* Currently always 2 */

  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
  void (*xDelete)(Fts5Tokenizer*);
  int (*xTokenize)(Fts5Tokenizer*,
      void *pCtx,
      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
      const char *pText, int nText,
      const char *pLocale, int nLocale,
      int (*xToken)(
        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
        int tflags,         /* Mask of FTS5_TOKEN_* flags */
        const char *pToken, /* Pointer to buffer containing token */
        int nToken,         /* Size of token in bytes */
        int iStart,         /* Byte offset of token within input text */
        int iEnd            /* Byte offset of end of token within input text */
      )
  );
};

/*
** New code should use the fts5_tokenizer_v2 type to define tokenizer
** implementations. The following type is included for legacy applications
** that still use it.
*/
typedef struct fts5_tokenizer fts5_tokenizer;
struct fts5_tokenizer {
  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
  void (*xDelete)(Fts5Tokenizer*);
  int (*xTokenize)(Fts5Tokenizer*,
      void *pCtx,
      int flags,            /* Mask of FTS5_TOKENIZE_* flags */
      const char *pText, int nText,
      int (*xToken)(
        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
        int tflags,         /* Mask of FTS5_TOKEN_* flags */
        const char *pToken, /* Pointer to buffer containing token */
        int nToken,         /* Size of token in bytes */
        int iStart,         /* Byte offset of token within input text */
        int iEnd            /* Byte offset of end of token within input text */
      )
  );
};


/* Flags that may be passed as the third argument to xTokenize() */
#define FTS5_TOKENIZE_QUERY     0x0001
#define FTS5_TOKENIZE_PREFIX    0x0002
#define FTS5_TOKENIZE_DOCUMENT  0x0004
#define FTS5_TOKENIZE_AUX       0x0008

/* Flags that may be passed by the tokenizer implementation back to FTS5
** as the third argument to the supplied xToken callback. */
#define FTS5_TOKEN_COLOCATED    0x0001      /* Same position as prev. token */

/*
** END OF CUSTOM TOKENIZERS
*************************************************************************/

/*************************************************************************
** FTS5 EXTENSION REGISTRATION API
*/
typedef struct fts5_api fts5_api;
struct fts5_api {
  int iVersion;                   /* Currently always set to 3 */

  /* Create a new tokenizer */
  int (*xCreateTokenizer)(
    fts5_api *pApi,
    const char *zName,
    void *pUserData,
    fts5_tokenizer *pTokenizer,

  int (*xCreateFunction)(
    fts5_api *pApi,
    const char *zName,
    void *pUserData,
    fts5_extension_function xFunction,
    void (*xDestroy)(void*)
  );

  /* APIs below this point are only available if iVersion>=3 */

  /* Create a new tokenizer */
  int (*xCreateTokenizer_v2)(
    fts5_api *pApi,
    const char *zName,
    void *pUserData,
    fts5_tokenizer_v2 *pTokenizer,
    void (*xDestroy)(void*)
  );

  /* Find an existing tokenizer */
  int (*xFindTokenizer_v2)(
    fts5_api *pApi,
    const char *zName,
    void **ppUserData,
    fts5_tokenizer_v2 **ppTokenizer
  );
};

/*
** END OF REGISTRATION API
*************************************************************************/

#if 0

*/

typedef struct Fts5Config Fts5Config;
typedef struct Fts5TokenizerConfig Fts5TokenizerConfig;

struct Fts5TokenizerConfig {
  Fts5Tokenizer *pTok;
  fts5_tokenizer_v2 *pApi2;
  fts5_tokenizer *pApi1;
  const char **azArg;
  int nArg;
  int ePattern;                   /* FTS_PATTERN_XXX constant */
  const char *pLocale;            /* Current locale to use */
  int nLocale;                    /* Size of pLocale in bytes */
};

/*
** An instance of the following structure encodes all information that can
** be gleaned from the CREATE VIRTUAL TABLE statement.
**
** And all information loaded from the %_config table.

**
** bPrefixIndex:
**   This is only used for debugging. If set to false, any prefix indexes
**   are ignored. This value is configured using:
**
**       INSERT INTO tbl(tbl, rank) VALUES('prefix-index', $bPrefixIndex);
**
** bLocale:
**   Set to true if locale=1 was specified when the table was created.
*/
struct Fts5Config {
  sqlite3 *db;                    /* Database handle */
  Fts5Global *pGlobal;            /* Global fts5 object for handle db */
  char *zDb;                      /* Database holding FTS index (e.g. "main") */
  char *zName;                    /* Name of FTS index */
  int nCol;                       /* Number of columns */
  char **azCol;                   /* Column names */
  u8 *abUnindexed;                /* True for unindexed columns */
  int nPrefix;                    /* Number of prefix indexes */
  int *aPrefix;                   /* Sizes in bytes of nPrefix prefix indexes */
  int eContent;                   /* An FTS5_CONTENT value */
  int bContentlessDelete;         /* "contentless_delete=" option (dflt==0) */
  char *zContent;                 /* content table */
  char *zContentRowid;            /* "content_rowid=" option value */
  int bColumnsize;                /* "columnsize=" option value (dflt==1) */
  int bTokendata;                 /* "tokendata=" option value (dflt==0) */
  int bLocale;                    /* "locale=" option value (dflt==0) */
  int eDetail;                    /* FTS5_DETAIL_XXX value */
  char *zContentExprlist;
  Fts5TokenizerConfig t;
  int bLock;                      /* True when table is preparing statement */


  /* Values loaded from the %_config table */
  int iVersion;                   /* fts5 file format 'version' */
  int iCookie;                    /* Incremented when %_config is modified */
  int pgsz;                       /* Approximate page size used in %_data */
  int nAutomerge;                 /* 'automerge' setting */
  int nCrisisMerge;               /* Maximum allowed segments per level */

static int sqlite3Fts5ConfigLoad(Fts5Config*, int);

/* Set the value of a single config attribute */
static int sqlite3Fts5ConfigSetValue(Fts5Config*, const char*, sqlite3_value*, int*);

static int sqlite3Fts5ConfigParseRank(const char*, char**, char**);

static void sqlite3Fts5ConfigErrmsg(Fts5Config *pConfig, const char *zFmt, ...);

/*
** End of interface to code in fts5_config.c.
**************************************************************************/

/**************************************************************************
** Interface to code in fts5_buffer.c.
*/

    sqlite3Fts5BufferSize((pRc),(pBuf),(nn)+(pBuf)->n) \
)

/* Write and decode big-endian 32-bit integer values */
static void sqlite3Fts5Put32(u8*, int);
static int sqlite3Fts5Get32(const u8*);

#define FTS5_POS2COLUMN(iPos) (int)((iPos >> 32) & 0x7FFFFFFF)
#define FTS5_POS2OFFSET(iPos) (int)(iPos & 0x7FFFFFFF)

typedef struct Fts5PoslistReader Fts5PoslistReader;
struct Fts5PoslistReader {
  /* Variables used only by sqlite3Fts5PoslistIterXXX() functions. */
  const u8 *a;                    /* Position list to iterate through */
  int n;                          /* Size of buffer at a[] in bytes */

static int sqlite3Fts5LoadTokenizer(Fts5Config *pConfig);

static Fts5Table *sqlite3Fts5TableFromCsrid(Fts5Global*, i64);

static int sqlite3Fts5FlushToDisk(Fts5Table*);

static int sqlite3Fts5ExtractText(
  Fts5Config *pConfig,
  sqlite3_value *pVal,            /* Value to extract text from */
  int bContent,                   /* Loaded from content table */
  int *pbResetTokenizer,          /* OUT: True if ClearLocale() required */
  const char **ppText,            /* OUT: Pointer to text buffer */
  int *pnText                     /* OUT: Size of (*ppText) in bytes */
);

static void sqlite3Fts5ClearLocale(Fts5Config *pConfig);

/*
** End of interface to code in fts5.c.
**************************************************************************/

/**************************************************************************
** Interface to code in fts5_hash.c.
*/

static int sqlite3Fts5StorageOpen(Fts5Config*, Fts5Index*, int, Fts5Storage**, char**);
static int sqlite3Fts5StorageClose(Fts5Storage *p);
static int sqlite3Fts5StorageRename(Fts5Storage*, const char *zName);

static int sqlite3Fts5DropAll(Fts5Config*);
static int sqlite3Fts5CreateTable(Fts5Config*, const char*, const char*, int, char **);

static int sqlite3Fts5StorageDelete(Fts5Storage *p, i64, sqlite3_value**, int);
static int sqlite3Fts5StorageContentInsert(Fts5Storage *p, sqlite3_value**, i64*);
static int sqlite3Fts5StorageIndexInsert(Fts5Storage *p, sqlite3_value**, i64);

static int sqlite3Fts5StorageIntegrity(Fts5Storage *p, int iArg);

static int sqlite3Fts5StorageStmt(Fts5Storage *p, int eStmt, sqlite3_stmt**, char**);
static void sqlite3Fts5StorageStmtRelease(Fts5Storage *p, int eStmt, sqlite3_stmt*);

static int sqlite3Fts5StorageDeleteAll(Fts5Storage *p);
static int sqlite3Fts5StorageRebuild(Fts5Storage *p);
static int sqlite3Fts5StorageOptimize(Fts5Storage *p);
static int sqlite3Fts5StorageMerge(Fts5Storage *p, int nMerge);
static int sqlite3Fts5StorageReset(Fts5Storage *p);

static void sqlite3Fts5StorageReleaseDeleteRow(Fts5Storage*);
static int sqlite3Fts5StorageFindDeleteRow(Fts5Storage *p, i64 iDel);

/*
** End of interface to code in fts5_storage.c.
**************************************************************************/


/**************************************************************************
** Interface to code in fts5_expr.c.

    }
    fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
    p->iOff = iEndOff;
  }

  return rc;
}


/*
** Implementation of highlight() function.
*/
static void fts5HighlightFunction(
  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
  Fts5Context *pFts,              /* First arg to pass to pApi functions */

  ctx.zClose = (const char*)sqlite3_value_text(apVal[2]);
  ctx.iRangeEnd = -1;
  rc = pApi->xColumnText(pFts, iCol, &ctx.zIn, &ctx.nIn);
  if( rc==SQLITE_RANGE ){
    sqlite3_result_text(pCtx, "", -1, SQLITE_STATIC);
    rc = SQLITE_OK;
  }else if( ctx.zIn ){
    const char *pLoc = 0;         /* Locale of column iCol */
    int nLoc = 0;                 /* Size of pLoc in bytes */
    if( rc==SQLITE_OK ){
      rc = fts5CInstIterInit(pApi, pFts, iCol, &ctx.iter);
    }

    if( rc==SQLITE_OK ){
      rc = pApi->xColumnLocale(pFts, iCol, &pLoc, &nLoc);
    }
    if( rc==SQLITE_OK ){
      rc = pApi->xTokenize_v2(
          pFts, ctx.zIn, ctx.nIn, pLoc, nLoc, (void*)&ctx, fts5HighlightCb
      );
    }
    if( ctx.bOpen ){
      fts5HighlightAppend(&rc, &ctx, ctx.zClose, -1);
    }
    fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);

    if( rc==SQLITE_OK ){

  if( rc==SQLITE_OK ){
    rc = pApi->xInstCount(pFts, &nInst);
  }

  memset(&sFinder, 0, sizeof(Fts5SFinder));
  for(i=0; i<nCol; i++){
    if( iCol<0 || iCol==i ){
      const char *pLoc = 0;       /* Locale of column iCol */
      int nLoc = 0;               /* Size of pLoc in bytes */
      int nDoc;
      int nDocsize;
      int ii;
      sFinder.iPos = 0;
      sFinder.nFirst = 0;
      rc = pApi->xColumnText(pFts, i, &sFinder.zDoc, &nDoc);
      if( rc!=SQLITE_OK ) break;
      rc = pApi->xColumnLocale(pFts, i, &pLoc, &nLoc);
      if( rc!=SQLITE_OK ) break;
      rc = pApi->xTokenize_v2(pFts,
          sFinder.zDoc, nDoc, pLoc, nLoc, (void*)&sFinder, fts5SentenceFinderCb
      );
      if( rc!=SQLITE_OK ) break;
      rc = pApi->xColumnSize(pFts, i, &nDocsize);
      if( rc!=SQLITE_OK ) break;

      for(ii=0; rc==SQLITE_OK && ii<nInst; ii++){
        int ip, ic, io;

  if( rc==SQLITE_OK ){
    rc = pApi->xColumnText(pFts, iBestCol, &ctx.zIn, &ctx.nIn);
  }
  if( rc==SQLITE_OK && nColSize==0 ){
    rc = pApi->xColumnSize(pFts, iBestCol, &nColSize);
  }
  if( ctx.zIn ){
    const char *pLoc = 0;         /* Locale of column iBestCol */
    int nLoc = 0;                 /* Bytes in pLoc */

    if( rc==SQLITE_OK ){
      rc = fts5CInstIterInit(pApi, pFts, iBestCol, &ctx.iter);
    }

    ctx.iRangeStart = iBestStart;
    ctx.iRangeEnd = iBestStart + nToken - 1;

    if( iBestStart>0 ){
      fts5HighlightAppend(&rc, &ctx, zEllips, -1);
    }

    /* Advance iterator ctx.iter so that it points to the first coalesced
    ** phrase instance at or following position iBestStart. */
    while( ctx.iter.iStart>=0 && ctx.iter.iStart<iBestStart && rc==SQLITE_OK ){
      rc = fts5CInstIterNext(&ctx.iter);
    }

    if( rc==SQLITE_OK ){
      rc = pApi->xColumnLocale(pFts, iBestCol, &pLoc, &nLoc);
    }
    if( rc==SQLITE_OK ){
      rc = pApi->xTokenize_v2(
          pFts, ctx.zIn, ctx.nIn, pLoc, nLoc, (void*)&ctx,fts5HighlightCb
      );
    }
    if( ctx.bOpen ){
      fts5HighlightAppend(&rc, &ctx, ctx.zClose, -1);
    }
    if( ctx.iRangeEnd>=(nColSize-1) ){
      fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);
    }else{

      );
    }
    sqlite3_result_double(pCtx, -1.0 * score);
  }else{
    sqlite3_result_error_code(pCtx, rc);
  }
}

/*
** Implementation of fts5_get_locale() function.
*/
static void fts5GetLocaleFunction(
  const Fts5ExtensionApi *pApi,   /* API offered by current FTS version */
  Fts5Context *pFts,              /* First arg to pass to pApi functions */
  sqlite3_context *pCtx,          /* Context for returning result/error */
  int nVal,                       /* Number of values in apVal[] array */
  sqlite3_value **apVal           /* Array of trailing arguments */
){
  int iCol = 0;
  int eType = 0;
  int rc = SQLITE_OK;
  const char *zLocale = 0;
  int nLocale = 0;

  /* xColumnLocale() must be available */
  assert( pApi->iVersion>=4 );

  if( nVal!=1 ){
    const char *z = "wrong number of arguments to function fts5_get_locale()";
    sqlite3_result_error(pCtx, z, -1);
    return;
  }

  eType = sqlite3_value_numeric_type(apVal[0]);
  if( eType!=SQLITE_INTEGER ){
    const char *z = "non-integer argument passed to function fts5_get_locale()";
    sqlite3_result_error(pCtx, z, -1);
    return;
  }

  iCol = sqlite3_value_int(apVal[0]);
  if( iCol<0 || iCol>=pApi->xColumnCount(pFts) ){
    sqlite3_result_error_code(pCtx, SQLITE_RANGE);
    return;
  }

  rc = pApi->xColumnLocale(pFts, iCol, &zLocale, &nLocale);
  if( rc!=SQLITE_OK ){
    sqlite3_result_error_code(pCtx, rc);
    return;
  }

  sqlite3_result_text(pCtx, zLocale, nLocale, SQLITE_TRANSIENT);
}

static int sqlite3Fts5AuxInit(fts5_api *pApi){
  struct Builtin {
    const char *zFunc;            /* Function name (nul-terminated) */
    void *pUserData;              /* User-data pointer */
    fts5_extension_function xFunc;/* Callback function */
    void (*xDestroy)(void*);      /* Destructor function */
  } aBuiltin [] = {
    { "snippet",         0, fts5SnippetFunction,   0 },
    { "highlight",       0, fts5HighlightFunction, 0 },
    { "bm25",            0, fts5Bm25Function,      0 },
    { "fts5_get_locale", 0, fts5GetLocaleFunction, 0 },
  };
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* To iterate through builtin functions */

  for(i=0; rc==SQLITE_OK && i<ArraySize(aBuiltin); i++){
    rc = pApi->xCreateFunction(pApi,
        aBuiltin[i].zFunc,

      *pzErr = sqlite3_mprintf("malformed columnsize=... directive");
      rc = SQLITE_ERROR;
    }else{
      pConfig->bColumnsize = (zArg[0]=='1');
    }
    return rc;
  }

  if( sqlite3_strnicmp("locale", zCmd, nCmd)==0 ){
    if( (zArg[0]!='0' && zArg[0]!='1') || zArg[1]!='\0' ){
      *pzErr = sqlite3_mprintf("malformed locale=... directive");
      rc = SQLITE_ERROR;
    }else{
      pConfig->bLocale = (zArg[0]=='1');
    }
    return rc;
  }

  if( sqlite3_strnicmp("detail", zCmd, nCmd)==0 ){
    const Fts5Enum aDetail[] = {
      { "none", FTS5_DETAIL_NONE },
      { "full", FTS5_DETAIL_FULL },
      { "columns", FTS5_DETAIL_COLUMNS },
      { 0, 0 }

/*
** Free the configuration object passed as the only argument.
*/
static void sqlite3Fts5ConfigFree(Fts5Config *pConfig){
  if( pConfig ){
    int i;
    if( pConfig->t.pTok ){
      if( pConfig->t.pApi1 ){
        pConfig->t.pApi1->xDelete(pConfig->t.pTok);
      }else{
        pConfig->t.pApi2->xDelete(pConfig->t.pTok);
      }
    }
    sqlite3_free((char*)pConfig->t.azArg);
    sqlite3_free(pConfig->zDb);
    sqlite3_free(pConfig->zName);
    for(i=0; i<pConfig->nCol; i++){
      sqlite3_free(pConfig->azCol[i]);
    }

){
  int rc = SQLITE_OK;
  if( pText ){
    if( pConfig->t.pTok==0 ){
      rc = sqlite3Fts5LoadTokenizer(pConfig);
    }
    if( rc==SQLITE_OK ){
      if( pConfig->t.pApi1 ){
        rc = pConfig->t.pApi1->xTokenize(
            pConfig->t.pTok, pCtx, flags, pText, nText, xToken
        );
      }else{
        rc = pConfig->t.pApi2->xTokenize(pConfig->t.pTok, pCtx, flags,
            pText, nText, pConfig->t.pLocale, pConfig->t.nLocale, xToken
        );
      }
    }
  }
  return rc;
}

/*
** Argument pIn points to the first character in what is expected to be

  }

  if( rc==SQLITE_OK
   && iVersion!=FTS5_CURRENT_VERSION
   && iVersion!=FTS5_CURRENT_VERSION_SECUREDELETE
  ){
    rc = SQLITE_ERROR;


    sqlite3Fts5ConfigErrmsg(pConfig, "invalid fts5 file format "
        "(found %d, expected %d or %d) - run 'rebuild'",
        iVersion, FTS5_CURRENT_VERSION, FTS5_CURRENT_VERSION_SECUREDELETE
    );

  }else{
    pConfig->iVersion = iVersion;
  }

  if( rc==SQLITE_OK ){
    pConfig->iCookie = iCookie;
  }
  return rc;
}

/*
** Set (*pConfig->pzErrmsg) to point to an sqlite3_malloc()ed buffer
** containing the error message created using printf() style formatting
** string zFmt and its trailing arguments.
*/
static void sqlite3Fts5ConfigErrmsg(Fts5Config *pConfig, const char *zFmt, ...){
  va_list ap;                     /* ... printf arguments */
  char *zMsg = 0;

  va_start(ap, zFmt);
  zMsg = sqlite3_vmprintf(zFmt, ap);
  if( pConfig->pzErrmsg ){
    assert( *pConfig->pzErrmsg==0 );
    *pConfig->pzErrmsg = zMsg;
  }else{
    sqlite3_free(zMsg);
  }

  va_end(ap);
}



/*
** 2014 May 31
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**

  do {
    t = fts5ExprGetToken(&sParse, &z, &token);
    sqlite3Fts5Parser(pEngine, t, token, &sParse);
  }while( sParse.rc==SQLITE_OK && t!=FTS5_EOF );
  sqlite3Fts5ParserFree(pEngine, fts5ParseFree);

  assert( sParse.pExpr || sParse.rc!=SQLITE_OK );
  assert_expr_depth_ok(sParse.rc, sParse.pExpr);

  /* If the LHS of the MATCH expression was a user column, apply the
  ** implicit column-filter.  */
  if( sParse.rc==SQLITE_OK && iCol<pConfig->nCol ){
    int n = sizeof(Fts5Colset);
    Fts5Colset *pColset = (Fts5Colset*)sqlite3Fts5MallocZero(&sParse.rc, n);
    if( pColset ){
      pColset->nCol = 1;
      pColset->aiCol[0] = iCol;
      sqlite3Fts5ParseSetColset(&sParse, sParse.pExpr, pColset);
    }
  }

  assert( sParse.rc!=SQLITE_OK || sParse.zErr==0 );
  if( sParse.rc==SQLITE_OK ){
    *ppNew = pNew = sqlite3_malloc(sizeof(Fts5Expr));
    if( pNew==0 ){
      sParse.rc = SQLITE_NOMEM;
      sqlite3Fts5ParseNodeFree(sParse.pExpr);
    }else{







      pNew->pRoot = sParse.pExpr;

      pNew->pIndex = 0;
      pNew->pConfig = pConfig;
      pNew->apExprPhrase = sParse.apPhrase;
      pNew->nPhrase = sParse.nPhrase;
      pNew->bDesc = 0;
      sParse.apPhrase = 0;
    }

          if( fts5ExprSynonymAdvanceto(pTerm, bDesc, &iLast, &rc) ){
            pNode->bNomatch = 0;
            pNode->bEof = 1;
            return rc;
          }
        }else{
          Fts5IndexIter *pIter = pPhrase->aTerm[j].pIter;
          if( pIter->iRowid==iLast ) continue;
          bMatch = 0;
          if( fts5ExprAdvanceto(pIter, bDesc, &iLast, &rc, &pNode->bEof) ){
            return rc;
          }
        }
      }
    }

  Fts5ExprNearset *pNear,         /* Existing nearset, or NULL */
  Fts5ExprPhrase *pPhrase         /* Recently parsed phrase */
){
  const int SZALLOC = 8;
  Fts5ExprNearset *pRet = 0;

  if( pParse->rc==SQLITE_OK ){



    if( pNear==0 ){
      sqlite3_int64 nByte;
      nByte = sizeof(Fts5ExprNearset) + SZALLOC * sizeof(Fts5ExprPhrase*);
      pRet = sqlite3_malloc64(nByte);
      if( pRet==0 ){
        pParse->rc = SQLITE_NOMEM;
      }else{

  Fts5Auxiliary *pNext;           /* Next registered auxiliary function */
};

/*
** Each tokenizer module registered with the FTS5 module is represented
** by an object of the following type. All such objects are stored as part
** of the Fts5Global.pTok list.
**
** bV2Native:
**  True if the tokenizer was registered using xCreateTokenizer_v2(), false
**  for xCreateTokenizer(). If this variable is true, then x2 is populated
**  with the routines as supplied by the caller and x1 contains synthesized
**  wrapper routines. In this case the user-data pointer passed to
**  x1.xCreate should be a pointer to the Fts5TokenizerModule structure,
**  not a copy of pUserData.
**
**  Of course, if bV2Native is false, then x1 contains the real routines and
**  x2 the synthesized ones. In this case a pointer to the Fts5TokenizerModule
**  object should be passed to x2.xCreate.
**
**  The synthesized wrapper routines are necessary for xFindTokenizer(_v2)
**  calls.
*/
struct Fts5TokenizerModule {
  char *zName;                    /* Name of tokenizer */
  void *pUserData;                /* User pointer passed to xCreate() */
  int bV2Native;                  /* True if v2 native tokenizer */
  fts5_tokenizer x1;              /* Tokenizer functions */
  fts5_tokenizer_v2 x2;           /* V2 tokenizer functions */
  void (*xDestroy)(void*);        /* Destructor function */
  Fts5TokenizerModule *pNext;     /* Next registered tokenizer module */
};

struct Fts5FullTable {
  Fts5Table p;                    /* Public class members from fts5Int.h */
  Fts5Storage *pStorage;          /* Document store */

  sqlite3_value **apRankArg;      /* Array of trailing arguments */
  sqlite3_stmt *pRankArgStmt;     /* Origin of objects in apRankArg[] */

  /* Auxiliary data storage */
  Fts5Auxiliary *pAux;            /* Currently executing extension function */
  Fts5Auxdata *pAuxdata;          /* First in linked list of saved aux-data */

  /* Cache used by auxiliary API functions xInst() and xInstCount() */
  Fts5PoslistReader *aInstIter;   /* One for each phrase */
  int nInstAlloc;                 /* Size of aInst[] array (entries / 3) */
  int nInstCount;                 /* Number of phrase instances */
  int *aInst;                     /* 3 integers per phrase instance */
};

/*

#define FTS5CSR_FREE_ZRANK        0x10
#define FTS5CSR_REQUIRE_RESEEK    0x20
#define FTS5CSR_REQUIRE_POSLIST   0x40

#define BitFlagAllTest(x,y) (((x) & (y))==(y))
#define BitFlagTest(x,y)    (((x) & (y))!=0)

/*
** The subtype value and header bytes used by fts5_locale().
*/
#define FTS5_LOCALE_SUBTYPE ((unsigned int)'L')
#define FTS5_LOCALE_HEADER  "\x00\xE0\xB2\xEB"


/*
** Macros to Set(), Clear() and Test() cursor flags.
*/
#define CsrFlagSet(pCsr, flag)   ((pCsr)->csrflags |= (flag))
#define CsrFlagClear(pCsr, flag) ((pCsr)->csrflags &= ~(flag))
#define CsrFlagTest(pCsr, flag)  ((pCsr)->csrflags & (flag))

        ** unusable plan. Return SQLITE_CONSTRAINT. */
        return SQLITE_CONSTRAINT;
      }else{
        if( iCol==nCol+1 ){
          if( bSeenRank ) continue;
          idxStr[iIdxStr++] = 'r';
          bSeenRank = 1;
        }else{
          nSeenMatch++;
          idxStr[iIdxStr++] = 'M';
          sqlite3_snprintf(6, &idxStr[iIdxStr], "%d", iCol);
          idxStr += strlen(&idxStr[iIdxStr]);
          assert( idxStr[iIdxStr]=='\0' );
        }
        pInfo->aConstraintUsage[i].argvIndex = ++iCons;

  zSql = sqlite3_vmprintf(zFmt, ap);
  if( zSql==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3_prepare_v3(pConfig->db, zSql, -1,
                            SQLITE_PREPARE_PERSISTENT, &pRet, 0);
    if( rc!=SQLITE_OK ){
      sqlite3Fts5ConfigErrmsg(pConfig, "%s", sqlite3_errmsg(pConfig->db));
    }
    sqlite3_free(zSql);
  }

  va_end(ap);
  *ppStmt = pRet;
  return rc;

  va_list ap;                     /* ... printf arguments */
  va_start(ap, zFormat);
  sqlite3_free(p->p.base.zErrMsg);
  p->p.base.zErrMsg = sqlite3_vmprintf(zFormat, ap);
  va_end(ap);
}

/*
** Arrange for subsequent calls to sqlite3Fts5Tokenize() to use the locale
** specified by pLocale/nLocale. The buffer indicated by pLocale must remain
** valid until after the final call to sqlite3Fts5Tokenize() that will use
** the locale.
*/
static void fts5SetLocale(
  Fts5Config *pConfig,
  const char *zLocale,
  int nLocale
){
  Fts5TokenizerConfig *pT = &pConfig->t;
  pT->pLocale = zLocale;
  pT->nLocale = nLocale;
}

/*
** Clear any locale configured by an earlier call to fts5SetLocale() or
** sqlite3Fts5ExtractText().
*/
static void sqlite3Fts5ClearLocale(Fts5Config *pConfig){
  fts5SetLocale(pConfig, 0, 0);
}

/*
** This function is used to extract utf-8 text from an sqlite3_value. This
** is usually done in order to tokenize it. For example, when:
**
**     * a value is written to an fts5 table,
**     * a value is deleted from an FTS5_CONTENT_NORMAL table,
**     * a value containing a query expression is passed to xFilter()
**
** and so on.
**
** This function handles 2 cases:
**
**   1) Ordinary values. The text can be extracted from these using
**      sqlite3_value_text().
**
**   2) Combination text/locale blobs created by fts5_locale(). There
**      are several cases for these:
**
**        * Blobs tagged with FTS5_LOCALE_SUBTYPE.
**        * Blobs read from the content table of a locale=1 external-content
**          table, and
**        * Blobs read from the content table of a locale=1 regular
**          content table.
**
**      The first two cases above should have the 4 byte FTS5_LOCALE_HEADER
**      header. It is an error if a blob with the subtype or a blob read
**      from the content table of an external content table does not have
**      the required header. A blob read from the content table of a regular
**      locale=1 table does not have the header. This is to save space.
**
** If successful, SQLITE_OK is returned and output parameters (*ppText)
** and (*pnText) are set to point to a buffer containing the extracted utf-8
** text and its length in bytes, respectively. The buffer is not
** nul-terminated. It has the same lifetime as the sqlite3_value object
** from which it is extracted.
**
** Parameter bContent must be true if the value was read from an indexed
** column (i.e. not UNINDEXED) of the on disk content.
**
** If pbResetTokenizer is not NULL and if case (2) is used, then
** fts5SetLocale() is called to ensure subsequent sqlite3Fts5Tokenize() calls
** use the locale. In this case (*pbResetTokenizer) is set to true before
** returning, to indicate that the caller must call sqlite3Fts5ClearLocale()
** to clear the locale after tokenizing the text.
*/
static int sqlite3Fts5ExtractText(
  Fts5Config *pConfig,
  sqlite3_value *pVal,            /* Value to extract text from */
  int bContent,                   /* True if indexed table content */
  int *pbResetTokenizer,          /* OUT: True if xSetLocale(NULL) required */
  const char **ppText,            /* OUT: Pointer to text buffer */
  int *pnText                     /* OUT: Size of (*ppText) in bytes */
){
  const char *pText = 0;
  int nText = 0;
  int rc = SQLITE_OK;
  int bDecodeBlob = 0;

  assert( pbResetTokenizer==0 || *pbResetTokenizer==0 );
  assert( bContent==0 || pConfig->eContent!=FTS5_CONTENT_NONE );
  assert( bContent==0 || sqlite3_value_subtype(pVal)==0 );

  if( sqlite3_value_type(pVal)==SQLITE_BLOB ){
    if( sqlite3_value_subtype(pVal)==FTS5_LOCALE_SUBTYPE
     || (bContent && pConfig->bLocale)
    ){
      bDecodeBlob = 1;
    }
  }

  if( bDecodeBlob ){
    const int SZHDR = sizeof(FTS5_LOCALE_HEADER)-1;
    const u8 *pBlob = sqlite3_value_blob(pVal);
    int nBlob = sqlite3_value_bytes(pVal);

    /* Unless this blob was read from the %_content table of an
    ** FTS5_CONTENT_NORMAL table, it should have the 4 byte fts5_locale()
    ** header. Check for this. If it is not found, return an error.  */
    if( (!bContent || pConfig->eContent!=FTS5_CONTENT_NORMAL) ){
      if( nBlob<SZHDR || memcmp(FTS5_LOCALE_HEADER, pBlob, SZHDR) ){
        rc = SQLITE_ERROR;
      }else{
        pBlob += 4;
        nBlob -= 4;
      }
    }

    if( rc==SQLITE_OK ){
      int nLocale = 0;

      for(nLocale=0; nLocale<nBlob; nLocale++){
        if( pBlob[nLocale]==0x00 ) break;
      }
      if( nLocale==nBlob || nLocale==0 ){
        rc = SQLITE_ERROR;
      }else{
        pText = (const char*)&pBlob[nLocale+1];
        nText = nBlob-nLocale-1;

        if( pbResetTokenizer ){
          fts5SetLocale(pConfig, (const char*)pBlob, nLocale);
          *pbResetTokenizer = 1;
        }
      }
    }

  }else{
    pText = (const char*)sqlite3_value_text(pVal);
    nText = sqlite3_value_bytes(pVal);
  }

  *ppText = pText;
  *pnText = nText;
  return rc;
}

/*
** Argument pVal is the text of a full-text search expression. It may or
** may not have been wrapped by fts5_locale(). This function extracts
** the text of the expression, and sets output variable (*pzText) to
** point to a nul-terminated buffer containing the expression.
**
** If pVal was an fts5_locale() value, then fts5SetLocale() is called to
** set the tokenizer to use the specified locale.
**
** If output variable (*pbFreeAndReset) is set to true, then the caller
** is required to (a) call sqlite3Fts5ClearLocale() to reset the tokenizer
** locale, and (b) call sqlite3_free() to free (*pzText).
*/
static int fts5ExtractExprText(
  Fts5Config *pConfig,            /* Fts5 configuration */
  sqlite3_value *pVal,            /* Value to extract expression text from */
  char **pzText,                  /* OUT: nul-terminated buffer of text */
  int *pbFreeAndReset             /* OUT: Free (*pzText) and clear locale */
){
  const char *zText = 0;
  int nText = 0;
  int rc = SQLITE_OK;
  int bReset = 0;

  *pbFreeAndReset = 0;
  rc = sqlite3Fts5ExtractText(pConfig, pVal, 0, &bReset, &zText, &nText);
  if( rc==SQLITE_OK ){
    if( bReset ){
      *pzText = sqlite3Fts5Mprintf(&rc, "%.*s", nText, zText);
      if( rc!=SQLITE_OK ){
        sqlite3Fts5ClearLocale(pConfig);
      }else{
        *pbFreeAndReset = 1;
      }
    }else{
      *pzText = (char*)zText;
    }
  }

  return rc;
}


/*
** This is the xFilter interface for the virtual table.  See
** the virtual table xFilter method documentation for additional
** information.
**
** There are three possible query strategies:

  sqlite3_value *pRowidGe = 0;    /* rowid >= ? expression (or NULL) */
  int iCol;                       /* Column on LHS of MATCH operator */
  char **pzErrmsg = pConfig->pzErrmsg;
  int i;
  int iIdxStr = 0;
  Fts5Expr *pExpr = 0;

  assert( pConfig->bLock==0 );






  if( pCsr->ePlan ){
    fts5FreeCursorComponents(pCsr);
    memset(&pCsr->ePlan, 0, sizeof(Fts5Cursor) - ((u8*)&pCsr->ePlan-(u8*)pCsr));
  }

  assert( pCsr->pStmt==0 );
  assert( pCsr->pExpr==0 );

  /* Decode the arguments passed through to this function. */
  for(i=0; i<nVal; i++){
    switch( idxStr[iIdxStr++] ){
      case 'r':
        pRank = apVal[i];
        break;
      case 'M': {
        char *zText = 0;
        int bFreeAndReset = 0;
        int bInternal = 0;

        rc = fts5ExtractExprText(pConfig, apVal[i], &zText, &bFreeAndReset);
        if( rc!=SQLITE_OK ) goto filter_out;
        if( zText==0 ) zText = "";

        iCol = 0;
        do{
          iCol = iCol*10 + (idxStr[iIdxStr]-'0');
          iIdxStr++;
        }while( idxStr[iIdxStr]>='0' && idxStr[iIdxStr]<='9' );

        if( zText[0]=='*' ){
          /* The user has issued a query of the form "MATCH '*...'". This
          ** indicates that the MATCH expression is not a full text query,
          ** but a request for an internal parameter.  */
          rc = fts5SpecialMatch(pTab, pCsr, &zText[1]);
          bInternal = 1;
        }else{
          char **pzErr = &pTab->p.base.zErrMsg;
          rc = sqlite3Fts5ExprNew(pConfig, 0, iCol, zText, &pExpr, pzErr);
          if( rc==SQLITE_OK ){
            rc = sqlite3Fts5ExprAnd(&pCsr->pExpr, pExpr);
            pExpr = 0;
          }
        }

        if( bFreeAndReset ){
          sqlite3_free(zText);
          sqlite3Fts5ClearLocale(pConfig);
        }

        if( bInternal || rc!=SQLITE_OK ) goto filter_out;

        break;
      }
      case 'L':
      case 'G': {
        int bGlob = (idxStr[iIdxStr-1]=='G');
        const char *zText = (const char*)sqlite3_value_text(apVal[i]);
        iCol = 0;

  Fts5FullTable *pTab,
  sqlite3_value **apVal
){
  int rc = SQLITE_OK;
  int eType1 = sqlite3_value_type(apVal[1]);
  if( eType1==SQLITE_INTEGER ){
    sqlite3_int64 iDel = sqlite3_value_int64(apVal[1]);
    rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, &apVal[2], 0);
  }
  return rc;
}

static void fts5StorageInsert(
  int *pRc,
  Fts5FullTable *pTab,

      );
      rc = SQLITE_ERROR;
    }

    /* DELETE */
    else if( nArg==1 ){
      i64 iDel = sqlite3_value_int64(apVal[0]);  /* Rowid to delete */
      rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, 0, 0);
      bUpdateOrDelete = 1;
    }

    /* INSERT or UPDATE */
    else{
      int eType1 = sqlite3_value_numeric_type(apVal[1]);

      /* Ensure that no fts5_locale() values are written to locale=0 tables.
      ** And that no blobs except fts5_locale() blobs are written to indexed
      ** (i.e. not UNINDEXED) columns of locale=1 tables. */
      int ii;
      for(ii=0; ii<pConfig->nCol; ii++){
        if( sqlite3_value_type(apVal[ii+2])==SQLITE_BLOB ){
          int bSub = (sqlite3_value_subtype(apVal[ii+2])==FTS5_LOCALE_SUBTYPE);
          if( (pConfig->bLocale && !bSub && pConfig->abUnindexed[ii]==0)
           || (pConfig->bLocale==0 && bSub)
          ){
            if( pConfig->bLocale==0 ){
              fts5SetVtabError(pTab, "fts5_locale() requires locale=1");
            }
            rc = SQLITE_MISMATCH;
            goto update_out;
          }
        }
      }

      if( eType0!=SQLITE_INTEGER ){
        /* An INSERT statement. If the conflict-mode is REPLACE, first remove
        ** the current entry (if any). */
        if( eConflict==SQLITE_REPLACE && eType1==SQLITE_INTEGER ){
          i64 iNew = sqlite3_value_int64(apVal[1]);  /* Rowid to delete */
          rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0, 0);
          bUpdateOrDelete = 1;
        }
        fts5StorageInsert(&rc, pTab, apVal, pRowid);
      }

      /* UPDATE */
      else{
        i64 iOld = sqlite3_value_int64(apVal[0]);  /* Old rowid */
        i64 iNew = sqlite3_value_int64(apVal[1]);  /* New rowid */
        if( eType1!=SQLITE_INTEGER ){
          rc = SQLITE_MISMATCH;
        }else if( iOld!=iNew ){
          if( eConflict==SQLITE_REPLACE ){
            rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0, 1);
            if( rc==SQLITE_OK ){
              rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0, 0);
            }
            fts5StorageInsert(&rc, pTab, apVal, pRowid);
          }else{
            rc = sqlite3Fts5StorageFindDeleteRow(pTab->pStorage, iOld);
            if( rc==SQLITE_OK ){
              rc = sqlite3Fts5StorageContentInsert(pTab->pStorage,apVal,pRowid);
            }
            if( rc==SQLITE_OK ){
              rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0, 1);
            }
            if( rc==SQLITE_OK ){
              rc = sqlite3Fts5StorageIndexInsert(pTab->pStorage, apVal,*pRowid);
            }
          }
        }else{
          rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0, 1);
          fts5StorageInsert(&rc, pTab, apVal, pRowid);
        }
        bUpdateOrDelete = 1;
        sqlite3Fts5StorageReleaseDeleteRow(pTab->pStorage);
      }

    }
  }

  if( rc==SQLITE_OK
   && bUpdateOrDelete
   && pConfig->bSecureDelete
   && pConfig->iVersion==FTS5_CURRENT_VERSION
  ){
    rc = sqlite3Fts5StorageConfigValue(
        pTab->pStorage, "version", 0, FTS5_CURRENT_VERSION_SECUREDELETE
    );
    if( rc==SQLITE_OK ){
      pConfig->iVersion = FTS5_CURRENT_VERSION_SECUREDELETE;
    }
  }

 update_out:
  pTab->p.pConfig->pzErrmsg = 0;
  return rc;
}

/*
** Implementation of xSync() method.
*/

static int fts5ApiRowCount(Fts5Context *pCtx, i64 *pnRow){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  Fts5FullTable *pTab = (Fts5FullTable*)(pCsr->base.pVtab);
  return sqlite3Fts5StorageRowCount(pTab->pStorage, pnRow);
}

/*
** Implementation of xTokenize_v2() API.
*/
static int fts5ApiTokenize_v2(
  Fts5Context *pCtx,
  const char *pText, int nText,
  const char *pLoc, int nLoc,
  void *pUserData,
  int (*xToken)(void*, int, const char*, int, int, int)
){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
  int rc = SQLITE_OK;

  fts5SetLocale(pTab->pConfig, pLoc, nLoc);
  rc = sqlite3Fts5Tokenize(pTab->pConfig,
      FTS5_TOKENIZE_AUX, pText, nText, pUserData, xToken
  );
  fts5SetLocale(pTab->pConfig, 0, 0);

  return rc;
}

/*
** Implementation of xTokenize() API. This is just xTokenize_v2() with NULL/0
** passed as the locale.
*/
static int fts5ApiTokenize(
  Fts5Context *pCtx,
  const char *pText, int nText,
  void *pUserData,
  int (*xToken)(void*, int, const char*, int, int, int)
){



  return fts5ApiTokenize_v2(pCtx, pText, nText, 0, 0, pUserData, xToken);

}

static int fts5ApiPhraseCount(Fts5Context *pCtx){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  return sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
}

  int iCol,
  const char **pz,
  int *pn
){
  int rc = SQLITE_OK;
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);

  assert( pCsr->ePlan!=FTS5_PLAN_SPECIAL );
  if( iCol<0 || iCol>=pTab->pConfig->nCol ){
    rc = SQLITE_RANGE;
  }else if( fts5IsContentless((Fts5FullTable*)(pCsr->base.pVtab)) ){


    *pz = 0;
    *pn = 0;
  }else{
    rc = fts5SeekCursor(pCsr, 0);
    if( rc==SQLITE_OK ){
      Fts5Config *pConfig = pTab->pConfig;
      int bContent = (pConfig->abUnindexed[iCol]==0);
      sqlite3_value *pVal = sqlite3_column_value(pCsr->pStmt, iCol+1);
      sqlite3Fts5ExtractText(pConfig, pVal, bContent, 0, pz, pn);
    }
  }
  return rc;
}

/*
** This is called by various API functions - xInst, xPhraseFirst,
** xPhraseFirstColumn etc. - to obtain the position list for phrase iPhrase
** of the current row. This function works for both detail=full tables (in
** which case the position-list was read from the fts index) or for other
** detail= modes if the row content is available.
*/
static int fts5CsrPoslist(
  Fts5Cursor *pCsr,               /* Fts5 cursor object */
  int iPhrase,                    /* Phrase to find position list for */
  const u8 **pa,                  /* OUT: Pointer to position list buffer */
  int *pn                         /* OUT: Size of (*pa) in bytes */
){
  Fts5Config *pConfig = ((Fts5Table*)(pCsr->base.pVtab))->pConfig;
  int rc = SQLITE_OK;
  int bLive = (pCsr->pSorter==0);

  if( iPhrase<0 || iPhrase>=sqlite3Fts5ExprPhraseCount(pCsr->pExpr) ){
    rc = SQLITE_RANGE;
  }else if( pConfig->eDetail!=FTS5_DETAIL_FULL
         && pConfig->eContent==FTS5_CONTENT_NONE
  ){
    *pa = 0;
    *pn = 0;
    return SQLITE_OK;
  }else if( CsrFlagTest(pCsr, FTS5CSR_REQUIRE_POSLIST) ){
    if( pConfig->eDetail!=FTS5_DETAIL_FULL ){
      Fts5PoslistPopulator *aPopulator;
      int i;

      aPopulator = sqlite3Fts5ExprClearPoslists(pCsr->pExpr, bLive);
      if( aPopulator==0 ) rc = SQLITE_NOMEM;
      if( rc==SQLITE_OK ){
        rc = fts5SeekCursor(pCsr, 0);
      }
      for(i=0; i<pConfig->nCol && rc==SQLITE_OK; i++){
        sqlite3_value *pVal = sqlite3_column_value(pCsr->pStmt, i+1);
        const char *z = 0;
        int n = 0;
        int bReset = 0;
        rc = sqlite3Fts5ExtractText(pConfig, pVal, 1, &bReset, &z, &n);
        if( rc==SQLITE_OK ){
          rc = sqlite3Fts5ExprPopulatePoslists(
              pConfig, pCsr->pExpr, aPopulator, i, z, n
          );
        }
        if( bReset ) sqlite3Fts5ClearLocale(pConfig);
      }
      sqlite3_free(aPopulator);

      if( pCsr->pSorter ){
        sqlite3Fts5ExprCheckPoslists(pCsr->pExpr, pCsr->pSorter->iRowid);
      }
    }

    }else{
      *pn = sqlite3Fts5ExprPoslist(pCsr->pExpr, iPhrase, pa);
    }
  }else{
    *pa = 0;
    *pn = 0;
  }


  return rc;
}

/*
** Ensure that the Fts5Cursor.nInstCount and aInst[] variables are populated
** correctly for the current view. Return SQLITE_OK if successful, or an

          }
        }

        aInst = &pCsr->aInst[3 * (nInst-1)];
        aInst[0] = iBest;
        aInst[1] = FTS5_POS2COLUMN(aIter[iBest].iPos);
        aInst[2] = FTS5_POS2OFFSET(aIter[iBest].iPos);
        assert( aInst[1]>=0 );
        if( aInst[1]>=nCol ){
          rc = FTS5_CORRUPT;
          break;
        }
        sqlite3Fts5PoslistReaderNext(&aIter[iBest]);
      }
    }