tokens) and it honors the same commenting conventions as C and C++.</p>

<h3>Terminals and Nonterminals</h3>

<p>A terminal symbol (token) is any string of alphanumeric
and underscore characters
that begins with an upper case letter.
A terminal can contain lower class letters after the first character,
but the usual convention is to make terminals all upper case.
A nonterminal, on the other hand, is any string of alphanumeric
and underscore characters than begins with a lower case letter.
Again, the usual convention is to make nonterminals use all lower
case letters.</p>

<p>In Lemon, terminal and nonterminal symbols do not need to 

tokens) and it honors the same commenting conventions as C and C++.</p>

<h3>Terminals and Nonterminals</h3>

<p>A terminal symbol (token) is any string of alphanumeric
and underscore characters
that begins with an upper case letter.
A terminal can contain lowercase letters after the first character,
but the usual convention is to make terminals all upper case.
A nonterminal, on the other hand, is any string of alphanumeric
and underscore characters than begins with a lower case letter.
Again, the usual convention is to make nonterminals use all lower
case letters.</p>

<p>In Lemon, terminal and nonterminal symbols do not need to 

** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#ifdef SQLITE_DEBUG



int sqlite3OSTrace = 0;
#define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
#define OSTRACE(X)
#endif

/*
** Macros for performance tracing.  Normally turned off.  Only works

** switch.  The following code should catch this problem at compile-time.
*/
#ifdef MEMORY_DEBUG
# error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
#endif

#ifdef SQLITE_DEBUG
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
# define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
#else
# define OSTRACE(X)
#endif

/*
** Macros for performance tracing.  Normally turned off.  Only works

};

/*
** Allowed values for the unixFile.ctrlFlags bitmask:
*/
#define UNIXFILE_EXCL   0x01     /* Connections from one process only */
#define UNIXFILE_RDONLY 0x02     /* Connection is read only */


/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*
................................................................................
** file-control operation.
**
** If the user has configured a chunk-size for this file, it could be
** that the file needs to be extended at this point. Otherwise, the
** SQLITE_FCNTL_SIZE_HINT operation is a no-op for Unix.
*/
static int fcntlSizeHint(unixFile *pFile, i64 nByte){
  if( pFile->szChunk ){
    i64 nSize;                    /* Required file size */

    struct stat buf;              /* Used to hold return values of fstat() */
   
    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;

    nSize = ((nByte+pFile->szChunk-1) / pFile->szChunk) * pFile->szChunk;





    if( nSize>(i64)buf.st_size ){

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
      /* The code below is handling the return value of osFallocate() 
      ** correctly. posix_fallocate() is defined to "returns zero on success, 
      ** or an error number on  failure". See the manpage for details. */
      int err;
................................................................................
  return SQLITE_OK;
}

/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){

  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = ((unixFile*)id)->eFileLock;
      return SQLITE_OK;
    }
    case SQLITE_LAST_ERRNO: {
      *(int*)pArg = ((unixFile*)id)->lastErrno;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      ((unixFile*)id)->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      return fcntlSizeHint((unixFile *)id, *(i64 *)pArg);











    }
#ifndef NDEBUG
    /* The pager calls this method to signal that it has done
    ** a rollback and that the database is therefore unchanged and
    ** it hence it is OK for the transaction change counter to be
    ** unchanged.
    */
................................................................................
  ** almost certain that an open() call on the same path will also fail.
  ** For this reason, if an error occurs in the stat() call here, it is
  ** ignored and -1 is returned. The caller will try to open a new file
  ** descriptor on the same path, fail, and return an error to SQLite.
  **
  ** Even if a subsequent open() call does succeed, the consequences of
  ** not searching for a resusable file descriptor are not dire.  */
  if( 0==stat(zPath, &sStat) ){
    unixInodeInfo *pInode;

    unixEnterMutex();
    pInode = inodeList;
    while( pInode && (pInode->fileId.dev!=sStat.st_dev
                     || pInode->fileId.ino!=sStat.st_ino) ){
       pInode = pInode->pNext;
................................................................................
    */
    nDb = sqlite3Strlen30(zPath) - 1; 
    while( nDb>0 && zPath[nDb]!='-' ) nDb--;
    if( nDb==0 ) return SQLITE_OK;
    memcpy(zDb, zPath, nDb);
    zDb[nDb] = '\0';

    if( 0==stat(zDb, &sStat) ){
      *pMode = sStat.st_mode & 0777;
    }else{
      rc = SQLITE_IOERR_FSTAT;
    }
  }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){
    *pMode = 0600;
  }
................................................................................

    default:
      assert(!"Invalid flags argument");
  }
  *pResOut = (osAccess(zPath, amode)==0);
  if( flags==SQLITE_ACCESS_EXISTS && *pResOut ){
    struct stat buf;
    if( 0==stat(zPath, &buf) && buf.st_size==0 ){
      *pResOut = 0;
    }
  }
  return SQLITE_OK;
}

};

/*
** 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 */

/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"

/*
................................................................................
** file-control operation.
**
** If the user has configured a chunk-size for this file, it could be
** that the file needs to be extended at this point. Otherwise, the
** SQLITE_FCNTL_SIZE_HINT operation is a no-op for Unix.
*/
static int fcntlSizeHint(unixFile *pFile, i64 nByte){
  { /* preserve indentation of removed "if" */
    i64 nSize;                    /* Required file size */
    i64 szChunk;                  /* Chunk size */
    struct stat buf;              /* Used to hold return values of fstat() */
   
    if( osFstat(pFile->h, &buf) ) return SQLITE_IOERR_FSTAT;

    szChunk = pFile->szChunk;
    if( szChunk==0 ){
      nSize = nByte;
    }else{
      nSize = ((nByte+szChunk-1) / szChunk) * szChunk;
    }
    if( nSize>(i64)buf.st_size ){

#if defined(HAVE_POSIX_FALLOCATE) && HAVE_POSIX_FALLOCATE
      /* The code below is handling the return value of osFallocate() 
      ** correctly. posix_fallocate() is defined to "returns zero on success, 
      ** or an error number on  failure". See the manpage for details. */
      int err;
................................................................................
  return SQLITE_OK;
}

/*
** Information and control of an open file handle.
*/
static int unixFileControl(sqlite3_file *id, int op, void *pArg){
  unixFile *pFile = (unixFile*)id;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = pFile->eFileLock;
      return SQLITE_OK;
    }
    case SQLITE_LAST_ERRNO: {
      *(int*)pArg = pFile->lastErrno;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      return fcntlSizeHint(pFile, *(i64 *)pArg);
    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = (pFile->ctrlFlags & UNIXFILE_PERSIST_WAL)!=0;
      }else if( bPersist==0 ){
        pFile->ctrlFlags &= ~UNIXFILE_PERSIST_WAL;
      }else{
        pFile->ctrlFlags |= UNIXFILE_PERSIST_WAL;
      }
      return SQLITE_OK;
    }
#ifndef NDEBUG
    /* The pager calls this method to signal that it has done
    ** a rollback and that the database is therefore unchanged and
    ** it hence it is OK for the transaction change counter to be
    ** unchanged.
    */
................................................................................
  ** almost certain that an open() call on the same path will also fail.
  ** For this reason, if an error occurs in the stat() call here, it is
  ** ignored and -1 is returned. The caller will try to open a new file
  ** descriptor on the same path, fail, and return an error to SQLite.
  **
  ** Even if a subsequent open() call does succeed, the consequences of
  ** not searching for a resusable file descriptor are not dire.  */
  if( 0==osStat(zPath, &sStat) ){
    unixInodeInfo *pInode;

    unixEnterMutex();
    pInode = inodeList;
    while( pInode && (pInode->fileId.dev!=sStat.st_dev
                     || pInode->fileId.ino!=sStat.st_ino) ){
       pInode = pInode->pNext;
................................................................................
    */
    nDb = sqlite3Strlen30(zPath) - 1; 
    while( nDb>0 && zPath[nDb]!='-' ) nDb--;
    if( nDb==0 ) return SQLITE_OK;
    memcpy(zDb, zPath, nDb);
    zDb[nDb] = '\0';

    if( 0==osStat(zDb, &sStat) ){
      *pMode = sStat.st_mode & 0777;
    }else{
      rc = SQLITE_IOERR_FSTAT;
    }
  }else if( flags & SQLITE_OPEN_DELETEONCLOSE ){
    *pMode = 0600;
  }
................................................................................

    default:
      assert(!"Invalid flags argument");
  }
  *pResOut = (osAccess(zPath, amode)==0);
  if( flags==SQLITE_ACCESS_EXISTS && *pResOut ){
    struct stat buf;
    if( 0==osStat(zPath, &buf) && buf.st_size==0 ){
      *pResOut = 0;
    }
  }
  return SQLITE_OK;
}

** portability layer.
*/
typedef struct winFile winFile;
struct winFile {
  const sqlite3_io_methods *pMethod; /*** Must be first ***/
  sqlite3_vfs *pVfs;      /* The VFS used to open this file */
  HANDLE h;               /* Handle for accessing the file */
  unsigned char locktype; /* Type of lock currently held on this file */
  short sharedLockByte;   /* Randomly chosen byte used as a shared lock */

  DWORD lastErrno;        /* The Windows errno from the last I/O error */
  DWORD sectorSize;       /* Sector size of the device file is on */
  winShm *pShm;           /* Instance of shared memory on this file */
  const char *zPath;      /* Full pathname of this file */
  int szChunk;            /* Chunk size configured by FCNTL_CHUNK_SIZE */
#if SQLITE_OS_WINCE
  WCHAR *zDeleteOnClose;  /* Name of file to delete when closing */
................................................................................
  return rc;
}

/*
** Control and query of the open file handle.
*/
static int winFileControl(sqlite3_file *id, int op, void *pArg){

  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = ((winFile*)id)->locktype;
      return SQLITE_OK;
    }
    case SQLITE_LAST_ERRNO: {
      *(int*)pArg = (int)((winFile*)id)->lastErrno;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      ((winFile*)id)->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      sqlite3_int64 sz = *(sqlite3_int64*)pArg;
      SimulateIOErrorBenign(1);
      winTruncate(id, sz);
      SimulateIOErrorBenign(0);
      return SQLITE_OK;









    }
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_WIN32_AV_RETRY: {
      int *a = (int*)pArg;
      if( a[0]>0 ){
................................................................................

  SimulateIOError( return SQLITE_IOERR_ACCESS; );
  zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return SQLITE_NOMEM;
  }
  if( isNT() ){

    WIN32_FILE_ATTRIBUTE_DATA sAttrData;
    memset(&sAttrData, 0, sizeof(sAttrData));
    if( GetFileAttributesExW((WCHAR*)zConverted,
                             GetFileExInfoStandard, 
                             &sAttrData) ){

      /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
      ** as if it does not exist.
      */
      if(    flags==SQLITE_ACCESS_EXISTS
          && sAttrData.nFileSizeHigh==0 
          && sAttrData.nFileSizeLow==0 ){
        attr = INVALID_FILE_ATTRIBUTES;
      }else{
        attr = sAttrData.dwFileAttributes;
      }
    }else{

      if( GetLastError()!=ERROR_FILE_NOT_FOUND ){
        winLogError(SQLITE_IOERR_ACCESS, "winAccess", zFilename);
        free(zConverted);
        return SQLITE_IOERR_ACCESS;
      }else{
        attr = INVALID_FILE_ATTRIBUTES;
      }
................................................................................
  free(zConverted);
  switch( flags ){
    case SQLITE_ACCESS_READ:
    case SQLITE_ACCESS_EXISTS:
      rc = attr!=INVALID_FILE_ATTRIBUTES;
      break;
    case SQLITE_ACCESS_READWRITE:

      rc = (attr & FILE_ATTRIBUTE_READONLY)==0;
      break;
    default:
      assert(!"Invalid flags argument");
  }
  *pResOut = rc;
  return SQLITE_OK;
}

** portability layer.
*/
typedef struct winFile winFile;
struct winFile {
  const sqlite3_io_methods *pMethod; /*** Must be first ***/
  sqlite3_vfs *pVfs;      /* The VFS used to open this file */
  HANDLE h;               /* Handle for accessing the file */
  u8 locktype;            /* Type of lock currently held on this file */
  short sharedLockByte;   /* Randomly chosen byte used as a shared lock */
  u8 bPersistWal;         /* True to persist WAL files */
  DWORD lastErrno;        /* The Windows errno from the last I/O error */
  DWORD sectorSize;       /* Sector size of the device file is on */
  winShm *pShm;           /* Instance of shared memory on this file */
  const char *zPath;      /* Full pathname of this file */
  int szChunk;            /* Chunk size configured by FCNTL_CHUNK_SIZE */
#if SQLITE_OS_WINCE
  WCHAR *zDeleteOnClose;  /* Name of file to delete when closing */
................................................................................
  return rc;
}

/*
** Control and query of the open file handle.
*/
static int winFileControl(sqlite3_file *id, int op, void *pArg){
  winFile *pFile = (winFile*)id;
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = pFile->locktype;
      return SQLITE_OK;
    }
    case SQLITE_LAST_ERRNO: {
      *(int*)pArg = (int)pFile->lastErrno;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SIZE_HINT: {
      sqlite3_int64 sz = *(sqlite3_int64*)pArg;
      SimulateIOErrorBenign(1);
      winTruncate(id, sz);
      SimulateIOErrorBenign(0);
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_PERSIST_WAL: {
      int bPersist = *(int*)pArg;
      if( bPersist<0 ){
        *(int*)pArg = pFile->bPersistWal;
      }else{
        pFile->bPersistWal = bPersist!=0;
      }
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_SYNC_OMITTED: {
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_WIN32_AV_RETRY: {
      int *a = (int*)pArg;
      if( a[0]>0 ){
................................................................................

  SimulateIOError( return SQLITE_IOERR_ACCESS; );
  zConverted = convertUtf8Filename(zFilename);
  if( zConverted==0 ){
    return SQLITE_NOMEM;
  }
  if( isNT() ){
    int cnt = 0;
    WIN32_FILE_ATTRIBUTE_DATA sAttrData;
    memset(&sAttrData, 0, sizeof(sAttrData));
    while( !(rc = GetFileAttributesExW((WCHAR*)zConverted,
                             GetFileExInfoStandard, 
                             &sAttrData)) && retryIoerr(&cnt) ){}
    if( rc ){
      /* For an SQLITE_ACCESS_EXISTS query, treat a zero-length file
      ** as if it does not exist.
      */
      if(    flags==SQLITE_ACCESS_EXISTS
          && sAttrData.nFileSizeHigh==0 
          && sAttrData.nFileSizeLow==0 ){
        attr = INVALID_FILE_ATTRIBUTES;
      }else{
        attr = sAttrData.dwFileAttributes;
      }
    }else{
      logIoerr(cnt);
      if( GetLastError()!=ERROR_FILE_NOT_FOUND ){
        winLogError(SQLITE_IOERR_ACCESS, "winAccess", zFilename);
        free(zConverted);
        return SQLITE_IOERR_ACCESS;
      }else{
        attr = INVALID_FILE_ATTRIBUTES;
      }
................................................................................
  free(zConverted);
  switch( flags ){
    case SQLITE_ACCESS_READ:
    case SQLITE_ACCESS_EXISTS:
      rc = attr!=INVALID_FILE_ATTRIBUTES;
      break;
    case SQLITE_ACCESS_READWRITE:
      rc = attr!=INVALID_FILE_ATTRIBUTES &&
             (attr & FILE_ATTRIBUTE_READONLY)==0;
      break;
    default:
      assert(!"Invalid flags argument");
  }
  *pResOut = rc;
  return SQLITE_OK;
}

** within the same process.  The argument is a pointer to an array of two
** integers where the first integer i the new retry count and the second
** integer is the delay.  If either integer is negative, then the setting
** is not changed but instead the prior value of that setting is written
** into the array entry, allowing the current retry settings to be
** interrogated.  The zDbName parameter is ignored.
** 














*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4
#define SQLITE_FCNTL_SIZE_HINT        5
#define SQLITE_FCNTL_CHUNK_SIZE       6
#define SQLITE_FCNTL_FILE_POINTER     7
#define SQLITE_FCNTL_SYNC_OMITTED     8
#define SQLITE_FCNTL_WIN32_AV_RETRY   9


/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

** within the same process.  The argument is a pointer to an array of two
** integers where the first integer i the new retry count and the second
** integer is the delay.  If either integer is negative, then the setting
** is not changed but instead the prior value of that setting is written
** into the array entry, allowing the current retry settings to be
** interrogated.  The zDbName parameter is ignored.
**
** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
** persistent [WAL | Write AHead Log] setting.  By default, the auxiliary
** write ahead log and shared memory files used for transaction control
** are automatically deleted when the latest connection to the database
** closes.  Setting persistent WAL mode causes those files to persist after
** close.  Persisting the files is useful when other processes that do not
** have write permission on the directory containing the database file want
** to read the database file, as the WAL and shared memory files must exist
** in order for the database to be readable.  The fourth parameter to
** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
** WAL mode.  If the integer is -1, then it is overwritten with the current
** WAL persistence setting.
** 
*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4
#define SQLITE_FCNTL_SIZE_HINT        5
#define SQLITE_FCNTL_CHUNK_SIZE       6
#define SQLITE_FCNTL_FILE_POINTER     7
#define SQLITE_FCNTL_SYNC_OMITTED     8
#define SQLITE_FCNTL_WIN32_AV_RETRY   9
#define SQLITE_FCNTL_PERSIST_WAL     10

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

  if( Tcl_GetIntFromObj(interp, objv[3], &a[1]) ) return TCL_ERROR;
  rc = sqlite3_file_control(db, NULL, SQLITE_FCNTL_WIN32_AV_RETRY, (void*)a);
  sqlite3_snprintf(sizeof(z), z, "%d %d %d", rc, a[0], a[1]);
  Tcl_AppendResult(interp, z, (char*)0);
  return TCL_OK;  
}


































/*
** tclcmd:   sqlite3_vfs_list
**
**   Return a tcl list containing the names of all registered vfs's.
*/
static int vfs_list(
................................................................................
     { "vfs_reregister_all",         vfs_reregister_all,  0   },
     { "file_control_test",          file_control_test,   0   },
     { "file_control_lasterrno_test", file_control_lasterrno_test,  0   },
     { "file_control_lockproxy_test", file_control_lockproxy_test,  0   },
     { "file_control_chunksize_test", file_control_chunksize_test,  0   },
     { "file_control_sizehint_test",  file_control_sizehint_test,   0   },
     { "file_control_win32_av_retry", file_control_win32_av_retry,  0   },

     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },

     /* Functions from os.h */
#ifndef SQLITE_OMIT_UTF16
     { "add_test_collate",        test_collate, 0            },
     { "add_test_collate_needed", test_collate_needed, 0     },

  if( Tcl_GetIntFromObj(interp, objv[3], &a[1]) ) return TCL_ERROR;
  rc = sqlite3_file_control(db, NULL, SQLITE_FCNTL_WIN32_AV_RETRY, (void*)a);
  sqlite3_snprintf(sizeof(z), z, "%d %d %d", rc, a[0], a[1]);
  Tcl_AppendResult(interp, z, (char*)0);
  return TCL_OK;  
}

/*
** tclcmd:   file_control_persist_wal DB PERSIST-FLAG
**
** This TCL command runs the sqlite3_file_control interface with
** the SQLITE_FCNTL_PERSIST_WAL opcode.
*/
static int file_control_persist_wal(
  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  sqlite3 *db;
  int rc;
  int bPersist;
  char z[100];

  if( objc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " DB FLAG", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ){
    return TCL_ERROR;
  }
  if( Tcl_GetIntFromObj(interp, objv[2], &bPersist) ) return TCL_ERROR;
  rc = sqlite3_file_control(db, NULL, SQLITE_FCNTL_PERSIST_WAL, (void*)&bPersist);
  sqlite3_snprintf(sizeof(z), z, "%d %d", rc, bPersist);
  Tcl_AppendResult(interp, z, (char*)0);
  return TCL_OK;  
}


/*
** tclcmd:   sqlite3_vfs_list
**
**   Return a tcl list containing the names of all registered vfs's.
*/
static int vfs_list(
................................................................................
     { "vfs_reregister_all",         vfs_reregister_all,  0   },
     { "file_control_test",          file_control_test,   0   },
     { "file_control_lasterrno_test", file_control_lasterrno_test,  0   },
     { "file_control_lockproxy_test", file_control_lockproxy_test,  0   },
     { "file_control_chunksize_test", file_control_chunksize_test,  0   },
     { "file_control_sizehint_test",  file_control_sizehint_test,   0   },
     { "file_control_win32_av_retry", file_control_win32_av_retry,  0   },
     { "file_control_persist_wal",    file_control_persist_wal,     0   },
     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },

     /* Functions from os.h */
#ifndef SQLITE_OMIT_UTF16
     { "add_test_collate",        test_collate, 0            },
     { "add_test_collate_needed", test_collate_needed, 0     },

static void multiplexSubClose(
  multiplexGroup *pGroup,
  int iChunk,
  sqlite3_vfs *pOrigVfs
){
  sqlite3_file *pSubOpen = pGroup->aReal[iChunk].p;
  if( pSubOpen ){
    if( pOrigVfs ) pOrigVfs->xDelete(pOrigVfs, pGroup->aReal[iChunk].z, 0);
    pSubOpen->pMethods->xClose(pSubOpen);

    sqlite3_free(pGroup->aReal[iChunk].p);
  }
  sqlite3_free(pGroup->aReal[iChunk].z);
  memset(&pGroup->aReal[iChunk], 0, sizeof(pGroup->aReal[iChunk]));
}

/*

static void multiplexSubClose(
  multiplexGroup *pGroup,
  int iChunk,
  sqlite3_vfs *pOrigVfs
){
  sqlite3_file *pSubOpen = pGroup->aReal[iChunk].p;
  if( pSubOpen ){

    pSubOpen->pMethods->xClose(pSubOpen);
    if( pOrigVfs ) pOrigVfs->xDelete(pOrigVfs, pGroup->aReal[iChunk].z, 0);
    sqlite3_free(pGroup->aReal[iChunk].p);
  }
  sqlite3_free(pGroup->aReal[iChunk].z);
  memset(&pGroup->aReal[iChunk], 0, sizeof(pGroup->aReal[iChunk]));
}

/*

    assert( pOut<=&aMem[p->nMem] );
    assert( pIn1<=&aMem[p->nMem] );
    assert( memIsValid(pIn1) );
    memAboutToChange(p, pOut);
    zMalloc = pOut->zMalloc;
    pOut->zMalloc = 0;
    sqlite3VdbeMemMove(pOut, pIn1);





    pIn1->zMalloc = zMalloc;
    REGISTER_TRACE(p2++, pOut);
    pIn1++;
    pOut++;
  }
  break;
}

    assert( pOut<=&aMem[p->nMem] );
    assert( pIn1<=&aMem[p->nMem] );
    assert( memIsValid(pIn1) );
    memAboutToChange(p, pOut);
    zMalloc = pOut->zMalloc;
    pOut->zMalloc = 0;
    sqlite3VdbeMemMove(pOut, pIn1);
#ifdef SQLITE_DEBUG
    if( pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrom<&aMem[p1+pOp->p3] ){
      pOut->pScopyFrom += p1 - pOp->p2;
    }
#endif
    pIn1->zMalloc = zMalloc;
    REGISTER_TRACE(p2++, pOut);
    pIn1++;
    pOut++;
  }
  break;
}

    ** the database. In this case checkpoint the database and unlink both
    ** the wal and wal-index files.
    **
    ** The EXCLUSIVE lock is not released before returning.
    */
    rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE);
    if( rc==SQLITE_OK ){

      if( pWal->exclusiveMode==WAL_NORMAL_MODE ){
        pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
      }
      rc = sqlite3WalCheckpoint(
          pWal, SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
      );

      if( rc==SQLITE_OK ){
        isDelete = 1;
      }
    }

    walIndexClose(pWal, isDelete);
    sqlite3OsClose(pWal->pWalFd);
    if( isDelete ){

    ** the database. In this case checkpoint the database and unlink both
    ** the wal and wal-index files.
    **
    ** The EXCLUSIVE lock is not released before returning.
    */
    rc = sqlite3OsLock(pWal->pDbFd, SQLITE_LOCK_EXCLUSIVE);
    if( rc==SQLITE_OK ){
      int bPersistWal = -1;
      if( pWal->exclusiveMode==WAL_NORMAL_MODE ){
        pWal->exclusiveMode = WAL_EXCLUSIVE_MODE;
      }
      rc = sqlite3WalCheckpoint(
          pWal, SQLITE_CHECKPOINT_PASSIVE, 0, 0, sync_flags, nBuf, zBuf, 0, 0
      );
      sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_PERSIST_WAL, &bPersistWal);
      if( rc==SQLITE_OK && bPersistWal!=1 ){
        isDelete = 1;
      }
    }

    walIndexClose(pWal, isDelete);
    sqlite3OsClose(pWal->pWalFd);
    if( isDelete ){

  ** to this virtual table */
  for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( pTerm->leftCursor != pSrc->iCursor ) continue;
    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
    testcase( pTerm->eOperator==WO_IN );
    testcase( pTerm->eOperator==WO_ISNULL );
    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;

    nTerm++;
  }

  /* If the ORDER BY clause contains only columns in the current 
  ** virtual table then allocate space for the aOrderBy part of
  ** the sqlite3_index_info structure.
  */
................................................................................

  for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( pTerm->leftCursor != pSrc->iCursor ) continue;
    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
    testcase( pTerm->eOperator==WO_IN );
    testcase( pTerm->eOperator==WO_ISNULL );
    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;

    pIdxCons[j].iColumn = pTerm->u.leftColumn;
    pIdxCons[j].iTermOffset = i;
    pIdxCons[j].op = (u8)pTerm->eOperator;
    /* The direct assignment in the previous line is possible only because
    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
    ** following asserts verify this fact. */
    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );

  ** to this virtual table */
  for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( pTerm->leftCursor != pSrc->iCursor ) continue;
    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
    testcase( pTerm->eOperator==WO_IN );
    testcase( pTerm->eOperator==WO_ISNULL );
    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
    if( pTerm->wtFlags & TERM_VNULL ) continue;
    nTerm++;
  }

  /* If the ORDER BY clause contains only columns in the current 
  ** virtual table then allocate space for the aOrderBy part of
  ** the sqlite3_index_info structure.
  */
................................................................................

  for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( pTerm->leftCursor != pSrc->iCursor ) continue;
    assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 );
    testcase( pTerm->eOperator==WO_IN );
    testcase( pTerm->eOperator==WO_ISNULL );
    if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue;
    if( pTerm->wtFlags & TERM_VNULL ) continue;
    pIdxCons[j].iColumn = pTerm->u.leftColumn;
    pIdxCons[j].iTermOffset = i;
    pIdxCons[j].op = (u8)pTerm->eOperator;
    /* The direct assignment in the previous line is possible only because
    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
    ** following asserts verify this fact. */
    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );

  e_fts3.test fts3cov.test fts3malloc.test fts3rnd.test
  fts3snippet.test

  # Exclude test scripts that use tcl IO to access journal files or count
  # the number of fsync() calls.
  pager.test exclusive.test jrnlmode.test sync.test misc1.test 
  journal1.test conflict.test crash8.test tkt3457.test io.test
  journal3.test

  pager1.test async4.test corrupt.test filefmt.test pager2.test
  corrupt5.test corruptA.test pageropt.test

  # Exclude stmt.test, which expects sub-journals to use temporary files.
  stmt.test

  # WAL mode is different.
  wal* tkt-2d1a5c67d.test
}]

ifcapable mem3 {
  test_suite "memsys3" -description {
    Run tests using the allocator in mem3.c.
  } -files [test_set $::allquicktests -exclude {
    autovacuum.test           delete3.test              manydb.test
................................................................................
} -initialize {
  catch {db close}
  register_jt_vfs -default ""
} -shutdown {
  unregister_jt_vfs
} -files [test_set $::allquicktests -exclude {
  wal* incrvacuum.test ioerr.test corrupt4.test io.test crash8.test 
  async4.test bigfile.test
}]

if {[info commands register_demovfs] != ""} {
  test_suite "demovfs" -description {
    Check that the demovfs (code in test_demovfs.c) more or less works.
  } -initialize {
    register_demovfs
................................................................................
      if {[llength $argv]>1} { set extra [list -files [lrange $argv 1 end]] }
      eval run_tests $suite $::testspec($suite) $extra
    }
  }
  main $argv
  finish_test
}

  e_fts3.test fts3cov.test fts3malloc.test fts3rnd.test
  fts3snippet.test

  # Exclude test scripts that use tcl IO to access journal files or count
  # the number of fsync() calls.
  pager.test exclusive.test jrnlmode.test sync.test misc1.test 
  journal1.test conflict.test crash8.test tkt3457.test io.test
  journal3.test 8_3_names.test

  pager1.test async4.test corrupt.test filefmt.test pager2.test
  corrupt5.test corruptA.test pageropt.test

  # Exclude stmt.test, which expects sub-journals to use temporary files.
  stmt.test

  # WAL mode is different.
  wal* tkt-2d1a5c67d.test backcompat.test
}]

ifcapable mem3 {
  test_suite "memsys3" -description {
    Run tests using the allocator in mem3.c.
  } -files [test_set $::allquicktests -exclude {
    autovacuum.test           delete3.test              manydb.test
................................................................................
} -initialize {
  catch {db close}
  register_jt_vfs -default ""
} -shutdown {
  unregister_jt_vfs
} -files [test_set $::allquicktests -exclude {
  wal* incrvacuum.test ioerr.test corrupt4.test io.test crash8.test 
  async4.test bigfile.test backcompat.test
}]

if {[info commands register_demovfs] != ""} {
  test_suite "demovfs" -description {
    Check that the demovfs (code in test_demovfs.c) more or less works.
  } -initialize {
    register_demovfs
................................................................................
      if {[llength $argv]>1} { set extra [list -files [lrange $argv 1 end]] }
      eval run_tests $suite $::testspec($suite) $extra
    }
  }
  main $argv
  finish_test
}

# 2011 August 3
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing that bug [d63523637517386191d634e]
# has been fixed.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

set ::testprefix tkt-d635236375

do_test 1.0 {
  execsql {
    CREATE TABLE t1(id1 INTEGER PRIMARY KEY);
    INSERT INTO t1 VALUES(9999);
    CREATE TABLE t2(id2 INTEGER PRIMARY KEY);
    INSERT INTO t2 VALUES(12345);
    INSERT INTO t2 VALUES(54321);
    SELECT DISTINCT id1 AS x, id1 AS y FROM t1, t2;
  }
} {9999 9999}
do_test 1.1 {
  execsql {
    SELECT count(*) FROM t1, t2 GROUP BY id1, id1;
  }
} {2}


finish_test

# 2011 Aug 1
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library. 
# This file checks to make sure IS NOT NULL constraints work on
# virtual tables.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !vtab||!schema_pragmas { finish_test ; return }

# Register the echo module
register_echo_module [sqlite3_connection_pointer db]

do_test vtabE-1.1 {
  execsql {
    CREATE TABLE t1(a, b);
    CREATE INDEX i1 ON t1(a);
    CREATE INDEX i2 ON t1(b);
    INSERT INTO t1 VALUES(10,110);
    INSERT INTO t1 VALUES(11,111);
    INSERT INTO t1 SELECT a+2, b+2 FROM t1;
    INSERT INTO t1 SELECT null, b+4 FROM t1;
    INSERT INTO t1 SELECT null, b+8 FROM t1;
    INSERT INTO t1 SELECT null, b+16 FROM t1;
    ANALYZE;
    CREATE VIRTUAL TABLE tv1 USING echo(t1);
    SELECT b FROM t1 WHERE a IS NOT NULL;
  }
} {110 111 112 113}
do_test vtabE-1.2 {
  execsql {SELECT b FROM tv1 WHERE a IS NOT NULL}
} {110 111 112 113}


finish_test

    } {}
    do_test 2.3.$tn.2 { file_page_counts } {1 5 1 5}
    do_test 2.3.$tn.3 { sql2 { BEGIN; SELECT * FROM t1 } } {1 2}
    do_test 2.3.$tn.4 { sql1 { INSERT INTO t1 VALUES(3, 4) } } {}
    do_test 2.3.$tn.5 { sql1 { INSERT INTO t2 VALUES(3, 4) } } {}
    do_test 2.3.$tn.6 { file_page_counts } {1 7 1 7}
    do_test 2.3.$tn.7 { code1 { do_wal_checkpoint db -mode full } } {1 7 5}
    if {$tcl_platform(platform) == "windows"} {
        # on unix, the size_hint is a no-op if no chunk size is set.
        # the windows implementation does not have a similar check,
        # and because of this, the db file size has an extra page.
        do_test 2.3.$tn.8 { file_page_counts } {2 7 2 7}
    } {
        do_test 2.3.$tn.8 { file_page_counts } {1 7 2 7}
    }
  }

  # Check that checkpoints block on the correct locks. And respond correctly
  # if they cannot obtain those locks. There are three locks that a checkpoint
  # may block on (in the following order):
  #
  #   1. The writer lock: FULL and RESTART checkpoints block until any writer
................................................................................

    do_test 3.$tn.6 { code3 { do_wal_checkpoint db3 } } {0 0 0}
  }
}


finish_test

    } {}
    do_test 2.3.$tn.2 { file_page_counts } {1 5 1 5}
    do_test 2.3.$tn.3 { sql2 { BEGIN; SELECT * FROM t1 } } {1 2}
    do_test 2.3.$tn.4 { sql1 { INSERT INTO t1 VALUES(3, 4) } } {}
    do_test 2.3.$tn.5 { sql1 { INSERT INTO t2 VALUES(3, 4) } } {}
    do_test 2.3.$tn.6 { file_page_counts } {1 7 1 7}
    do_test 2.3.$tn.7 { code1 { do_wal_checkpoint db -mode full } } {1 7 5}




    do_test 2.3.$tn.8 { file_page_counts } {2 7 2 7}



  }

  # Check that checkpoints block on the correct locks. And respond correctly
  # if they cannot obtain those locks. There are three locks that a checkpoint
  # may block on (in the following order):
  #
  #   1. The writer lock: FULL and RESTART checkpoints block until any writer
................................................................................

    do_test 3.$tn.6 { code3 { do_wal_checkpoint db3 } } {0 0 0}
  }
}


finish_test

# 2011 July 26
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains tests for using WAL with persistent WAL file mode.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
set ::testprefix walpersist

do_test walpersist-1.0 {
  db eval {
    PRAGMA journal_mode=WAL;
    CREATE TABLE t1(a);
    INSERT INTO t1 VALUES(randomblob(5000));
  }
  file exists test.db-wal
} {1}
do_test walpersist-1.1 {
  file exists test.db-shm
} {1}
do_test walpersist-1.2 {
  db close
  list [file exists test.db] [file exists test.db-wal] [file exists test.db-shm]
} {1 0 0}
do_test walpersist-1.3 {
  sqlite3 db test.db
  db eval {SELECT length(a) FROM t1}
} {5000}
do_test walpersist-1.4 {
  list [file exists test.db] [file exists test.db-wal] [file exists test.db-shm]
} {1 1 1}
do_test walpersist-1.5 {
  file_control_persist_wal db -1
} {0 0}
do_test walpersist-1.6 {
  file_control_persist_wal db 1
} {0 1}
do_test walpersist-1.7 {
  file_control_persist_wal db -1
} {0 1}
do_test walpersist-1.8 {
  file_control_persist_wal db 0
} {0 0}
do_test walpersist-1.9 {
  file_control_persist_wal db -1
} {0 0}
do_test walpersist-1.10 {
  file_control_persist_wal db 1
} {0 1}
do_test walpersist-1.11 {
  db close
  list [file exists test.db] [file exists test.db-wal] [file exists test.db-shm]
} {1 1 1}

  


finish_test

       set ::msg
    } {disk I/O error}
    break
  } else {
    do_test win32lock-1.2-$delay1 {
       set ::msg
    } {1 100000 2 50000 3 25000 4 12500}
    if {$::log!=""} {
      do_test win32lock-1.2-$delay1-log1 {
        regsub {\d+} $::log # x
        set x
      } {{delayed #ms for lock/sharing conflict}}
    }
    incr delay1 50
  }

       set ::msg
    } {disk I/O error}
    break
  } else {
    do_test win32lock-1.2-$delay1 {
       set ::msg
    } {1 100000 2 50000 3 25000 4 12500}
    if {[info exists ::log] && $::log!=""} {
      do_test win32lock-1.2-$delay1-log1 {
        regsub {\d+} $::log # x
        set x
      } {{delayed #ms for lock/sharing conflict}}
    }
    incr delay1 50
  }