SQLite

  va_start(ap, zFormat);
  z = sqlite3VMPrintf(db, zFormat, ap);
  va_end(ap);
  sqlite3DbFree(db, *pz);
  *pz = z;
}

/*
** Take actions at the end of an API call to indicate an OOM error
*/
static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
  db->mallocFailed = 0;
  sqlite3Error(db, SQLITE_NOMEM);
  return SQLITE_NOMEM;
}

/*
** This function must be called before exiting any API function (i.e. 
** returning control to the user) that has called sqlite3_malloc or
** sqlite3_realloc.
**
** The returned value is normally a copy of the second argument to this
** function. However, if a malloc() failure has occurred since the previous
** invocation SQLITE_NOMEM is returned instead. 
**
** If the first argument, db, is not NULL and a malloc() error has occurred,
** then the connection error-code (the value returned by sqlite3_errcode())
** is set to SQLITE_NOMEM.
*/
int sqlite3ApiExit(sqlite3* db, int rc){
  /* If the db handle is not NULL, then we must hold the connection handle
  ** mutex here. Otherwise the read (and possible write) of db->mallocFailed 
  ** is unsafe, as is the call to sqlite3Error().
  */
  assert( !db || sqlite3_mutex_held(db->mutex) );
  if( db==0 ) return rc & 0xff;
  if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
    return apiOomError(db);


  }
  return rc & db->errMask;
}