SQLite

  int *pnList,                    /* OUT: List length pointer */
  u8 *pbEof                       /* OUT: End-of-file flag */
){
  char *p = *ppIter;

  assert( nDoclist>0 );
  assert( *pbEof==0 );
  assert( p || *piDocid==0 );
  assert_fts3_nc( p || *piDocid==0 );
  assert( !p || (p>aDoclist && p<&aDoclist[nDoclist]) );

  if( p==0 ){
    sqlite3_int64 iDocid = 0;
    char *pNext = 0;
    char *pDocid = aDoclist;
    char *pEnd = &aDoclist[nDoclist];

  /* Version 3.34.0 and later */
  sqlite3_txn_state,
  /* Version 3.36.1 and later */
  sqlite3_changes64,
  sqlite3_total_changes64,
  /* Version 3.37.0 and later */
  sqlite3_autovacuum_pages,
  /* Version 3.38.0 and later */
  sqlite3_error_offset,
};

/* True if x is the directory separator character
*/
#if SQLITE_OS_WIN
# define DirSep(X)  ((X)=='/'||(X)=='\\')
#else

    if( z==0 ){
      z = sqlite3ErrStr(db->errCode);
    }
  }
  sqlite3_mutex_leave(db->mutex);
  return z;
}

/*
** Return the byte offset of the most recent error
*/
int sqlite3_error_offset(sqlite3 *db){
  int iOffset = -1;
  if( db && sqlite3SafetyCheckSickOrOk(db) && db->errCode ){
    sqlite3_mutex_enter(db->mutex);
    iOffset = db->errByteOffset;
    sqlite3_mutex_leave(db->mutex);
  }
  return iOffset;
}

#ifndef SQLITE_OMIT_UTF16
/*
** Return UTF-16 encoded English language explanation of the most recent
** error.
*/
const void *sqlite3_errmsg16(sqlite3 *db){

      case etTOKEN: {
        Token *pToken;
        if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;
        pToken = va_arg(ap, Token*);
        assert( bArgList==0 );
        if( pToken && pToken->n ){
          sqlite3_str_append(pAccum, (const char*)pToken->z, pToken->n);
          sqlite3RecordErrorByteOffset(pAccum->db, pToken->z);
        }
        length = width = 0;
        break;
      }
      case etSRCITEM: {
        SrcItem *pItem;
        if( (pAccum->printfFlags & SQLITE_PRINTF_INTERNAL)==0 ) return;

    if( zExtra ){
      sqlite3DbFree(pAccum->db, zExtra);
      zExtra = 0;
    }
  }/* End for loop over the format string */
} /* End of function */


/*
** The z string points to the first character of a token that is
** associated with an error.  If db does not already have an error
** byte offset recorded, try to compute the error byte offset for
** z and set the error byte offset in db.
*/
void sqlite3RecordErrorByteOffset(sqlite3 *db, const char *z){
  const Parse *pParse;
  const char *zText;
  const char *zEnd;
  assert( z!=0 );
  if( NEVER(db==0) ) return;
  if( db->errByteOffset!=(-2) ) return;
  pParse = db->pParse;
  if( NEVER(pParse==0) ) return;
  zText =pParse->zTail;
  if( NEVER(zText==0) ) return;
  zEnd = &zText[strlen(zText)];
  if( SQLITE_WITHIN(z,zText,zEnd) ){
    db->errByteOffset = (int)(z-zText);
  }
}

/*
** Enlarge the memory allocation on a StrAccum object so that it is
** able to accept at least N more bytes of text.
**
** Return the number of bytes of text that StrAccum is able to accept
** after the attempted enlargement.  The value returned might be zero.
*/

    z[n++] = zName[i];
    if( zName[i]==cQuote ) z[n++] = cQuote;
  }
  if( cQuote ) z[n++] = cQuote;
  z[n] = 0;
}

/*
** Maybe construct two lines of text that point out the position of a
** syntax error.  Return a pointer to the text, in memory obtained from
** sqlite3_malloc().  Or, if the most recent error does not involve a
** specific token that we can point to, return an empty string.
**
** In all cases, the memory returned is obtained from sqlite3_malloc64()
** and should be released by the caller invoking sqlite3_free().
*/
static char *shell_error_context(const char *zSql, sqlite3 *db){
  int iOffset;
  size_t len;
  char *zCode;
  char *zMsg;
  int i;
  if( db==0
   || zSql==0
   || (iOffset = sqlite3_error_offset(db))<0
  ){
    return sqlite3_mprintf("");
  }
  while( iOffset>50 ){
    iOffset--;
    zSql++;
    while( (zSql[0]&0xc0)==0x80 ){ zSql++; iOffset--; }
  }
  len = strlen(zSql);
  if( len>78 ){
    len = 78;
    while( (zSql[len]&0xc0)==0x80 ) len--;
  }
  zCode = sqlite3_mprintf("%.*s", len, zSql);
  for(i=0; zCode[i]; i++){ if( IsSpace(zSql[i]) ) zCode[i] = ' '; }
  if( iOffset<25 ){
    zMsg = sqlite3_mprintf("\n  %z\n  %*s^--- error here", zCode, iOffset, "");
  }else{
    zMsg = sqlite3_mprintf("\n  %z\n  %*serror here ---^", zCode, iOffset-14, "");
  }
  return zMsg;
}


/*
** Execute a query statement that will generate SQL output.  Print
** the result columns, comma-separated, on a line and then add a
** semicolon terminator to the end of that line.
**
** If the number of columns is 1 and that column contains text "--"

  sqlite3_stmt *pSelect;
  int rc;
  int nResult;
  int i;
  const char *z;
  rc = sqlite3_prepare_v2(p->db, zSelect, -1, &pSelect, 0);
  if( rc!=SQLITE_OK || !pSelect ){
    char *zContext = shell_error_context(zSelect, p->db);
    utf8_printf(p->out, "/**** ERROR: (%d) %s *****/\n", rc,
                sqlite3_errmsg(p->db));
    utf8_printf(p->out, "/**** ERROR: (%d) %s *****/\n%s", rc,
                sqlite3_errmsg(p->db), zContext);
    sqlite3_free(zContext);
    if( (rc&0xff)!=SQLITE_CORRUPT ) p->nErr++;
    return rc;
  }
  rc = sqlite3_step(pSelect);
  nResult = sqlite3_column_count(pSelect);
  while( rc==SQLITE_ROW ){
    z = (const char*)sqlite3_column_text(pSelect, 0);

/*
** Allocate space and save off string indicating current error.
*/
static char *save_err_msg(
  sqlite3 *db,           /* Database to query */
  const char *zWhen,     /* Qualifier (format) wrapper */
  int rc                 /* Error code returned from API */
  int rc,                /* Error code returned from API */
  const char *zSql       /* SQL string, or NULL */
){
  char *zErr;
  char *zContext;
  if( zWhen==0 ) zWhen = "%s (%d)";
  zErr = sqlite3_mprintf(zWhen, sqlite3_errmsg(db), rc);
  if( zWhen==0 ) zWhen = "%s (%d)%s";
  zContext = shell_error_context(zSql, db);
  zErr = sqlite3_mprintf(zWhen, sqlite3_errmsg(db), rc, zContext);
  shell_check_oom(zErr);
  sqlite3_free(zContext);
  return zErr;
}

#ifdef __linux__
/*
** Attempt to display I/O stats on Linux using /proc/PID/io
*/

#endif

  while( zSql[0] && (SQLITE_OK == rc) ){
    static const char *zStmtSql;
    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
    if( SQLITE_OK != rc ){
      if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db, "in prepare, %s (%d)", rc);
        *pzErrMsg = save_err_msg(db, "in prepare, %s (%d)%s", rc, zSql);
      }
    }else{
      if( !pStmt ){
        /* this happens for a comment or white-space */
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
        continue;

      ** next statement to execute. */
      rc2 = sqlite3_finalize(pStmt);
      if( rc!=SQLITE_NOMEM ) rc = rc2;
      if( rc==SQLITE_OK ){
        zSql = zLeftover;
        while( IsSpace(zSql[0]) ) zSql++;
      }else if( pzErrMsg ){
        *pzErrMsg = save_err_msg(db, "stepping, %s (%d)", rc);
        *pzErrMsg = save_err_msg(db, "stepping, %s (%d)", rc, 0);
      }

      /* clear saved stmt handle */
      if( pArg ){
        pArg->pStmt = NULL;
      }
    }

  "   --limit N                 Interrupt after N progress callbacks",
  "   --once                    Do no more than one progress interrupt",
  "   --quiet|-q                No output except at interrupts",
  "   --reset                   Reset the count for each input and interrupt",
#endif
  ".prompt MAIN CONTINUE    Replace the standard prompts",
  ".quit                    Exit this program",
  ".read FILE               Read input from FILE",
  ".read FILE               Read input from FILE or command output",
  "    If FILE begins with \"|\", it is a command that generates the input.",
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_ENABLE_DBPAGE_VTAB)
  ".recover                 Recover as much data as possible from corrupt db.",
  "   --freelist-corrupt       Assume the freelist is corrupt",
  "   --recovery-db NAME       Store recovery metadata in database file NAME",
  "   --lost-and-found TABLE   Alternative name for the lost-and-found table",
  "   --no-rowids              Do not attempt to recover rowid values",
  "                            that are not also INTEGER PRIMARY KEYs",

** [extended result code] even when extended result codes are
** disabled.
**
** The values returned by sqlite3_errcode() and/or
** sqlite3_extended_errcode() might change with each API call.
** Except, there are some interfaces that are guaranteed to never
** change the value of the error code.  The error-code preserving
** interfaces are:
** interfaces include the following:
**
** <ul>
** <li> sqlite3_errcode()
** <li> sqlite3_extended_errcode()
** <li> sqlite3_errmsg()
** <li> sqlite3_errmsg16()
** <li> sqlite3_error_offset()
** </ul>
**
** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF-8 or UTF-16 respectively.
** ^(Memory to hold the error message string is managed internally.
** The application does not need to worry about freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.)^
**
** ^The sqlite3_errstr() interface returns the English-language text
** that describes the [result code], as UTF-8.
** ^(Memory to hold the error message string is managed internally
** and must not be freed by the application)^.
**
** ^If the most recent error references a specific token in the input
** SQL, the sqlite3_error_offset() interface returns the byte offset
** of the start of that token.  ^The byte offset returned by
** sqlite3_error_offset() assumes that the input SQL is UTF8.
** ^If the most error does not reference a specific token in the input
** SQL, then the sqlite3_error_offset() function returns -1.
**
** When the serialized [threading mode] is in use, it might be the
** case that a second error occurs on a separate thread in between
** the time of the first error and the call to these interfaces.
** When that happens, the second error will be reported since these
** interfaces always report the most recent result.  To avoid
** this, each thread can obtain exclusive use of the [database connection] D
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
** all calls to the interfaces listed here are completed.
**
** If an interface fails with SQLITE_MISUSE, that means the interface
** was invoked incorrectly by the application.  In that case, the
** error code and message may or may not be set.
*/
int sqlite3_errcode(sqlite3 *db);
int sqlite3_extended_errcode(sqlite3 *db);
const char *sqlite3_errmsg(sqlite3*);
const void *sqlite3_errmsg16(sqlite3*);
const char *sqlite3_errstr(int);
int sqlite3_error_offset(sqlite3 *db);

/*
** CAPI3REF: Prepared Statement Object
** KEYWORDS: {prepared statement} {prepared statements}
**
** An instance of this object represents a single SQL statement that
** has been compiled into binary form and is ready to be evaluated.

  /* Version 3.36.1 and later */
  sqlite3_int64 (*changes64)(sqlite3*);
  sqlite3_int64 (*total_changes64)(sqlite3*);
  /* Version 3.37.0 and later */
  int (*autovacuum_pages)(sqlite3*,
     unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
     void*, void(*)(void*));
  /* Version 3.38.0 and later */
  int (*error_offset)(sqlite3*);
};

/*
** This is the function signature used for all extension entry points.  It
** is also defined in the file "loadext.c".
*/
typedef int (*sqlite3_loadext_entry)(

/* Version 3.34.0 and later */
#define sqlite3_txn_state              sqlite3_api->txn_state
/* Version 3.36.1 and later */
#define sqlite3_changes64              sqlite3_api->changes64
#define sqlite3_total_changes64        sqlite3_api->total_changes64
/* Version 3.37.0 and later */
#define sqlite3_autovacuum_pages       sqlite3_api->autovacuum_pages
/* Version 3.38.0 and later */
#define sqlite3_error_offset           sqlite3_api->error_offset
#endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */

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

  u32 mDbFlags;                 /* flags recording internal state */
  u64 flags;                    /* flags settable by pragmas. See below */
  i64 lastRowid;                /* ROWID of most recent insert (see above) */
  i64 szMmap;                   /* Default mmap_size setting */
  u32 nSchemaLock;              /* Do not reset the schema when non-zero */
  unsigned int openFlags;       /* Flags passed to sqlite3_vfs.xOpen() */
  int errCode;                  /* Most recent error code (SQLITE_*) */
  int errByteOffset;            /* Byte offset of error in SQL statement */
  int errMask;                  /* & result codes with this before returning */
  int iSysErrno;                /* Errno value from last system error */
  u32 dbOptFlags;               /* Flags to enable/disable optimizations */
  u8 enc;                       /* Text encoding */
  u8 autoCommit;                /* The auto-commit flag. */
  u8 temp_store;                /* 1: file 2: memory 0: default */
  u8 mallocFailed;              /* True if we have seen a malloc failure */

void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
int sqlite3StrAccumEnlarge(StrAccum*, int);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumSetError(StrAccum*, u8);
void sqlite3ResultStrAccum(sqlite3_context*,StrAccum*);
void sqlite3SelectDestInit(SelectDest*,int,int);
Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);
void sqlite3RecordErrorByteOffset(sqlite3*,const char*);

void sqlite3BackupRestart(sqlite3_backup *);
void sqlite3BackupUpdate(sqlite3_backup *, Pgno, const u8 *);

#ifndef SQLITE_OMIT_SUBQUERY
int sqlite3ExprCheckIN(Parse*, Expr*);
#else

  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;

  zErr = sqlite3_errmsg(db);
  Tcl_SetObjResult(interp, Tcl_NewStringObj(zErr, -1));
  return TCL_OK;
}


/*
** Usage:   sqlite3_error_offset DB
**
** Return the byte offset into the input UTF8 SQL for the most recent
** error, or -1 of the error does not refer to a specific token.
*/
static int SQLITE_TCLAPI test_error_offset(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  int iByteOffset;

  if( objc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", 
       Tcl_GetString(objv[0]), " DB", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;

  iByteOffset = sqlite3_error_offset(db);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(iByteOffset));
  return TCL_OK;
}

/*
** Usage:   test_errmsg16 DB
**
** Returns the UTF-16 representation of the error message string for the
** most recent sqlite3_* API call. This is a byte array object at the TCL 
** level, and it includes the 0x00 0x00 terminator bytes at the end of the
** UTF-16 string.

     { "sqlite3_bind_parameter_name",   test_bind_parameter_name,  0},
     { "sqlite3_bind_parameter_index",  test_bind_parameter_index, 0},
     { "sqlite3_clear_bindings",        test_clear_bindings, 0},
     { "sqlite3_sleep",                 test_sleep,          0},
     { "sqlite3_errcode",               test_errcode       ,0 },
     { "sqlite3_extended_errcode",      test_ex_errcode    ,0 },
     { "sqlite3_errmsg",                test_errmsg        ,0 },
     { "sqlite3_error_offset",          test_error_offset  ,0 },
     { "sqlite3_errmsg16",              test_errmsg16      ,0 },
     { "sqlite3_open",                  test_open          ,0 },
     { "sqlite3_open16",                test_open16        ,0 },
     { "sqlite3_open_v2",               test_open_v2       ,0 },
     { "sqlite3_complete16",            test_complete16    ,0 },
     { "sqlite3_normalize",             test_normalize     ,0 },

** Set the current error code to err_code and clear any prior error message.
** Also set iSysErrno (by calling sqlite3System) if the err_code indicates
** that would be appropriate.
*/
void sqlite3Error(sqlite3 *db, int err_code){
  assert( db!=0 );
  db->errCode = err_code;
  if( err_code || db->pErr ) sqlite3ErrorFinish(db, err_code);
  if( err_code || db->pErr ){
    sqlite3ErrorFinish(db, err_code);
  }else{
    db->errByteOffset = -1;
  }
}

/*
** The equivalent of sqlite3Error(db, SQLITE_OK).  Clear the error state
** and error message.
*/
void sqlite3ErrorClear(sqlite3 *db){
  assert( db!=0 );
  db->errCode = SQLITE_OK;
  db->errByteOffset = -1;
  if( db->pErr ) sqlite3ValueSetNull(db->pErr);
}

/*
** Load the sqlite3.iSysErrno field if that is an appropriate thing
** to do based on the SQLite error code in rc.
*/
void sqlite3SystemError(sqlite3 *db, int rc){
  if( rc==SQLITE_IOERR_NOMEM ) return;
  rc &= 0xff;
  if( rc==SQLITE_CANTOPEN || rc==SQLITE_IOERR ){
    db->iSysErrno = sqlite3OsGetLastError(db->pVfs);
  }
}

/*
** Set the most recent error code and error string for the sqlite
** handle "db". The error code is set to "err_code".
**
** If it is not NULL, string zFormat specifies the format of the
** error string in the style of the printf functions: The following
** format characters are allowed:
**
**      %s      Insert a string
**      %z      A string that should be freed after use
**      %d      Insert an integer
**      %T      Insert a token
**      %S      Insert the first element of a SrcList
**
** zFormat and any string tokens that follow it are assumed to be
** encoded in UTF-8.
** error string.  zFormat and any string tokens that follow it are
** assumed to be encoded in UTF-8.
**
** To clear the most recent error for sqlite handle "db", sqlite3Error
** should be called with err_code set to SQLITE_OK and zFormat set
** to NULL.
*/
void sqlite3ErrorWithMsg(sqlite3 *db, int err_code, const char *zFormat, ...){
  assert( db!=0 );

    va_end(ap);
    sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
  }
}

/*
** Add an error message to pParse->zErrMsg and increment pParse->nErr.
** The following formatting characters are allowed:
**
**      %s      Insert a string
**      %z      A string that should be freed after use
**      %d      Insert an integer
**      %T      Insert a token
**      %S      Insert the first element of a SrcList
**
** This function should be used to report any error that occurs while
** compiling an SQL statement (i.e. within sqlite3_prepare()). The
** last thing the sqlite3_prepare() function does is copy the error
** stored by this function into the database handle using sqlite3Error().
** Functions sqlite3Error() or sqlite3ErrorWithMsg() should be used
** during statement execution (sqlite3_step() etc.).
*/
void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){
  char *zMsg;
  va_list ap;
  sqlite3 *db = pParse->db;
  db->errByteOffset = -2;
  va_start(ap, zFormat);
  zMsg = sqlite3VMPrintf(db, zFormat, ap);
  va_end(ap);
  if( db->errByteOffset<-1 ) db->errByteOffset = -1;
  if( db->suppressErr ){
    sqlite3DbFree(db, zMsg);
  }else{
    pParse->nErr++;
    sqlite3DbFree(db, pParse->zErrMsg);
    pParse->zErrMsg = zMsg;
    pParse->rc = SQLITE_ERROR;