SQLite

sqlite3_result_value
sqlite3_rollback_hook
sqlite3_set_authorizer
sqlite3_set_auxdata
sqlite3_snprintf
sqlite3_soft_heap_limit
sqlite3_step
sqlite3_thread_cleanup
sqlite3_total_changes
sqlite3_trace
sqlite3_transfer_bindings
sqlite3_update_hook
sqlite3_user_data
sqlite3_value_blob
sqlite3_value_bytes

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.16 2006/01/11 21:41:21 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.

  char *zName = 0;          /* NULL-terminated version of pName */ 
  sqlite3 *db = pParse->db; /* Database connection */
  Vdbe *v;
#ifndef SQLITE_OMIT_TRIGGER
  char *zWhere = 0;         /* Where clause to locate temp triggers */
#endif
  
  if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto exit_rename_table;
  assert( pSrc->nSrc==1 );

  pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
  if( !pTab ) goto exit_rename_table;
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  zDb = db->aDb[iDb].zName;

  Vdbe *v;
  int iDb;
  int i;
  int nAlloc;

  /* Look up the table being altered. */
  assert( pParse->pNewTable==0 );
  if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto exit_begin_add_column;
  pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
  if( !pTab ) goto exit_begin_add_column;

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

/*
** 2003 April 6
**
** 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 code used to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.46 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
** identifiers are treated as strings, not possible column names or aliases.

  int rc;
  NameContext sName;
  Vdbe *v;
  FuncDef *pFunc;
  sqlite3* db = pParse->db;

#ifndef SQLITE_OMIT_AUTHORIZATION
  assert( sqlite3ThreadDataReadOnly()->mallocFailed || pAuthArg );
  if( pAuthArg ){
    char *zAuthArg = sqlite3NameFromToken(&pAuthArg->span);
    if( !zAuthArg ){
      goto attach_end;
    }
    rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
    sqliteFree(zAuthArg);

  }

  v = sqlite3GetVdbe(pParse);
  sqlite3ExprCode(pParse, pFilename);
  sqlite3ExprCode(pParse, pDbname);
  sqlite3ExprCode(pParse, pKey);

  assert(v || sqlite3ThreadDataReadOnly()->mallocFailed);
  if( v ){
    sqlite3VdbeAddOp(v, OP_Function, 0, nFunc);
    pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);
    sqlite3VdbeChangeP3(v, -1, (char *)pFunc, P3_FUNCDEF);

    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
    ** statement only). For DETACH, set it to false (expire all existing

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.291 2006/01/11 21:41:22 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

/*
** Save the positions of all cursors except pExcept open on the table 
** with root-page iRoot. Usually, this is called just before cursor
** pExcept is used to modify the table (BtreeDelete() or BtreeInsert()).
*/
static int saveAllCursors(BtShared *pBt, Pgno iRoot, BtCursor *pExcept){
  BtCursor *p;
  if( sqlite3ThreadDataReadOnly()->useSharedData ){
    for(p=pBt->pCursor; p; p=p->pNext){
      if( p!=pExcept && p->pgnoRoot==iRoot && p->eState==CURSOR_VALID ){
        int rc = saveCursorPosition(p);
        if( SQLITE_OK!=rc ){
          return rc;
        }
      }

** If the second argument argument - doSeek - is false, then instead of 
** returning the cursor to it's saved position, any saved position is deleted
** and the cursor state set to CURSOR_INVALID.
*/
static int restoreCursorPosition(BtCursor *pCur, int doSeek){
  int rc = SQLITE_OK;
  if( pCur->eState==CURSOR_REQUIRESEEK ){
    assert( sqlite3ThreadDataReadOnly()->useSharedData );
    if( doSeek ){
      rc = sqlite3BtreeMoveto(pCur, pCur->pKey, pCur->nKey, &pCur->skip);
    }else{
      pCur->eState = CURSOR_INVALID;
    }
    if( rc==SQLITE_OK ){
      sqliteFree(pCur->pKey);

** SQLITE_LOCKED if not.
*/
static int queryTableLock(Btree *p, Pgno iTab, u8 eLock){
  BtShared *pBt = p->pBt;
  BtLock *pIter;

  /* This is a no-op if the shared-cache is not enabled */
  if( 0==sqlite3ThreadDataReadOnly()->useSharedData ){
    return SQLITE_OK;
  }

  /* This (along with lockTable()) is where the ReadUncommitted flag is
  ** dealt with. If the caller is querying for a read-lock and the flag is
  ** set, it is unconditionally granted - even if there are write-locks
  ** on the table. If a write-lock is requested, the ReadUncommitted flag

*/
static int lockTable(Btree *p, Pgno iTable, u8 eLock){
  BtShared *pBt = p->pBt;
  BtLock *pLock = 0;
  BtLock *pIter;

  /* This is a no-op if the shared-cache is not enabled */
  if( 0==sqlite3ThreadDataReadOnly()->useSharedData ){
    return SQLITE_OK;
  }

  assert( SQLITE_OK==queryTableLock(p, iTable, eLock) );

  /* If the read-uncommitted flag is set and a read-lock is requested,
  ** return early without adding an entry to the BtShared.pLock list. See

static void unlockAllTables(Btree *p){
  BtLock **ppIter = &p->pBt->pLock;

  /* If the shared-cache extension is not enabled, there should be no
  ** locks in the BtShared.pLock list, making this procedure a no-op. Assert
  ** that this is the case.
  */
  assert( sqlite3ThreadDataReadOnly()->useSharedData || 0==*ppIter );

  while( *ppIter ){
    BtLock *pLock = *ppIter;
    if( pLock->pBtree==p ){
      *ppIter = pLock->pNext;
      sqliteFree(pLock);
    }else{

  int flags               /* Options */
){
  BtShared *pBt;          /* Shared part of btree structure */
  Btree *p;               /* Handle to return */
  int rc;
  int nReserve;
  unsigned char zDbHeader[100];
#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
  const ThreadData *pTsdro;
#endif

  /* Set the variable isMemdb to true for an in-memory database, or 
  ** false for a file-based database. This symbol is only required if
  ** either of the shared-data or autovacuum features are compiled 
  ** into the library.
  */

    return SQLITE_NOMEM;
  }
  p->inTrans = TRANS_NONE;
  p->pSqlite = pSqlite;

  /* Try to find an existing Btree structure opened on zFilename. */
#if !defined(SQLITE_OMIT_SHARED_CACHE) && !defined(SQLITE_OMIT_DISKIO)
  pTsdro = sqlite3ThreadDataReadOnly();
  if( pTsdro->useSharedData && zFilename && !isMemdb ){
    char *zFullPathname = sqlite3OsFullPathname(zFilename);
    if( !zFullPathname ){
      sqliteFree(p);
      return SQLITE_NOMEM;
    }
    for(pBt=pTsdro->pBtree; pBt; pBt=pBt->pNext){
      assert( pBt->nRef>0 );
      if( 0==strcmp(zFullPathname, sqlite3pager_filename(pBt->pPager)) ){
        p->pBt = pBt;
        *ppBtree = p;
        pBt->nRef++;
        sqliteFree(zFullPathname);
        return SQLITE_OK;

  }
  pBt->usableSize = pBt->pageSize - nReserve;
  assert( (pBt->pageSize & 7)==0 );  /* 8-byte alignment of pageSize */
  sqlite3pager_set_pagesize(pBt->pPager, pBt->pageSize);

#ifndef SQLITE_OMIT_SHARED_CACHE
  /* Add the new btree to the linked list starting at ThreadData.pBtree */
  if( pTsdro->useSharedData && zFilename && !isMemdb ){
    pBt->pNext = pTsdro->pBtree;
    sqlite3ThreadData()->pBtree = pBt;
  }
#endif
  pBt->nRef = 1;
  *ppBtree = p;
  return SQLITE_OK;
}

/*
** Close an open database and invalidate all cursors.
*/
int sqlite3BtreeClose(Btree *p){
  BtShared *pBt = p->pBt;
  BtCursor *pCur;

#ifndef SQLITE_OMIT_SHARED_CACHE
  ThreadData *pTsd;
#endif

  /* Drop any table-locks */
  unlockAllTables(p);

  /* Close all cursors opened via this handle.  */
  pCur = pBt->pCursor;

  assert( pBt->nRef>0 );
  pBt->nRef--;
  if( pBt->nRef ){
    return SQLITE_OK;
  }

  /* Remove the shared-btree from the thread wide list */
  pTsd = sqlite3ThreadData();
  if( pTsd->pBtree==pBt ){
    pTsd->pBtree = pBt->pNext;
  }else{
    BtShared *pPrev;
    for(pPrev=pTsd->pBtree; pPrev && pPrev->pNext!=pBt; pPrev=pPrev->pNext);
    if( pPrev ){
      pPrev->pNext = pBt->pNext;

  if( rc==SQLITE_OK ){
    rc = lockTable(p, iTab, lockType);
  }
#endif
  return rc;
}

/*
** The following debugging interface has to be in this file (rather
** than in, for example, test1.c) so that it can get access to
** the definition of BtShared.
*/
#if defined(SQLITE_TEST) && defined(TCLSH)
#include <tcl.h>
int sqlite3_shared_cache_report(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  const ThreadData *pTd = sqlite3ThreadDataReadOnly();
  if( pTd->useSharedData ){
    BtShared *pBt;
    Tcl_Obj *pRet = Tcl_NewObj();
    for(pBt=pTd->pBtree; pBt; pBt=pBt->pNext){
      const char *zFile = sqlite3pager_filename(pBt->pPager);
      Tcl_ListObjAppendElement(interp, pRet, Tcl_NewStringObj(zFile, -1));
      Tcl_ListObjAppendElement(interp, pRet, Tcl_NewIntObj(pBt->nRef));
    }
    Tcl_SetObjResult(interp, pRet);
  }
  return TCL_OK;
}
#endif

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.377 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.

  int iTab, 
  u8 isWriteLock,  
  const char *zName
){
  int i;
  int nBytes;
  TableLock *p;


  if( 0==sqlite3ThreadDataReadOnly()->useSharedData || iDb<0 ){
    return;
  }

  for(i=0; i<pParse->nTableLock; i++){
    p = &pParse->aTableLock[i];
    if( p->iDb==iDb && p->iTab==iTab ){
      p->isWriteLock = (p->isWriteLock || isWriteLock);

/*
** Code an OP_TableLock instruction for each table locked by the
** statement (configured by calls to sqlite3TableLock()).
*/
static void codeTableLocks(Parse *pParse){
  int i;
  Vdbe *pVdbe; 
  assert( sqlite3ThreadDataReadOnly()->useSharedData || pParse->nTableLock==0 );

  if( 0==(pVdbe = sqlite3GetVdbe(pParse)) ){
    return;
  }

  for(i=0; i<pParse->nTableLock; i++){
    TableLock *p = &pParse->aTableLock[i];

** Note that if an error occurred, it might be the case that
** no VDBE code was generated.
*/
void sqlite3FinishCoding(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( sqlite3ThreadDataReadOnly()->mallocFailed ) return;
  if( pParse->nested ) return;
  if( !pParse->pVdbe ){
    if( pParse->rc==SQLITE_OK && pParse->nErr ){
      pParse->rc = SQLITE_ERROR;
    }
    return;
  }

  Select *pSelect         /* Select from a "CREATE ... AS SELECT" */
){
  Table *p;
  sqlite3 *db = pParse->db;
  int iDb;

  if( (pEnd==0 && pSelect==0) || 
      pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ) {
    return;
  }
  p = pParse->pNewTable;
  if( p==0 ) return;

  assert( !db->init.busy || !pSelect );

  /* Make a copy of the entire SELECT statement that defines the view.
  ** This will force all the Expr.token.z values to be dynamically
  ** allocated rather than point to the input string - which means that
  ** they will persist after the current sqlite3_exec() call returns.
  */
  p->pSelect = sqlite3SelectDup(pSelect);
  sqlite3SelectDelete(pSelect);
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return;
  }
  if( !pParse->db->init.busy ){
    sqlite3ViewGetColumnNames(pParse, p);
  }

  /* Locate the end of the CREATE VIEW statement.  Make sEnd point to

*/
void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
  Table *pTab;
  Vdbe *v;
  sqlite3 *db = pParse->db;
  int iDb;

  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto exit_drop_table;
  }
  assert( pName->nSrc==1 );
  pTab = sqlite3LocateTable(pParse, pName->a[0].zName, pName->a[0].zDatabase);

  if( pTab==0 ){
    if( noErr ){
      sqlite3ErrorClear(pParse);
    }

  int iDb;             /* Index of the database that is being written */
  Token *pName = 0;    /* Unqualified name of the index to create */
  struct ExprList_item *pListItem; /* For looping over pList */
  int nCol;
  int nExtra = 0;
  char *zExtra;

  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto exit_create_index;
  }

  /*
  ** Find the table that is to be indexed.  Return early if not found.
  */
  if( pTblName!=0 ){

      sizeof(int)*nCol +           /* Index.aiColumn   */
      sizeof(int)*(nCol+1) +       /* Index.aiRowEst   */
      sizeof(char *)*nCol +        /* Index.azColl     */
      sizeof(u8)*nCol +            /* Index.aSortOrder */
      nName + 1 +                  /* Index.zName      */
      nExtra                       /* Collation sequence names */
  );
  if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto exit_create_index;
  pIndex->aiColumn = (int *)(&pIndex[1]);
  pIndex->aiRowEst = (int *)(&pIndex->aiColumn[nCol]);
  pIndex->azColl = (char **)(&pIndex->aiRowEst[nCol+1]);
  pIndex->aSortOrder = (u8 *)(&pIndex->azColl[nCol]);
  pIndex->zName = (char *)(&pIndex->aSortOrder[nCol]);
  zExtra = (char *)(&pIndex->zName[nName+1]);
  strcpy(pIndex->zName, zName);

*/
void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){
  Index *pIndex;
  Vdbe *v;
  sqlite3 *db = pParse->db;
  int iDb;

  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto exit_drop_index;
  }
  assert( pName->nSrc==1 );
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto exit_drop_index;
  }
  pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);

/*
** Assign cursors to all tables in a SrcList
*/
void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
  int i;
  struct SrcList_item *pItem;
  assert(pList || sqlite3ThreadDataReadOnly()->mallocFailed);
  if( pList ){
    for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
      if( pItem->iCursor>=0 ) break;
      pItem->iCursor = pParse->nTab++;
      if( pItem->pSelect ){
        sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);
      }

*/
void sqlite3BeginTransaction(Parse *pParse, int type){
  sqlite3 *db;
  Vdbe *v;
  int i;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  if( type!=TK_DEFERRED ){
    for(i=0; i<db->nDb; i++){
      sqlite3VdbeAddOp(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
    }
  }
  sqlite3VdbeAddOp(v, OP_AutoCommit, 0, 0);
}

/*
** Commit a transaction
*/
void sqlite3CommitTransaction(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 0);
  }
}

/*
** Rollback a transaction
*/
void sqlite3RollbackTransaction(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 1);
  }
}

  if( pParse->nErr ){
    sqliteFree(pKey);
    pKey = 0;
  }
  return pKey;
}

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains functions used to access the internal hash tables
** of user defined functions and collation sequences.
**
** $Id: callback.c,v 1.11 2006/01/11 21:41:22 drh Exp $
*/

#include "sqliteInt.h"

/*
** Invoke the 'collation needed' callback to request a collation sequence
** in the database text encoding of name zName, length nName.

      pColl[0].zName[nName] = 0;
      pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, nName, pColl);

      /* If a malloc() failure occured in sqlite3HashInsert(), it will 
      ** return the pColl pointer to be deleted (because it wasn't added
      ** to the hash table).
      */
      assert( !pDel ||
              (sqlite3ThreadDataReadOnly()->mallocFailed && pDel==pColl) );
      sqliteFree(pDel);
    }
  }
  return pColl;
}

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.118 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.

#ifndef SQLITE_OMIT_TRIGGER
  int isView;                  /* True if attempting to delete from a view */
  int triggers_exist = 0;      /* True if any triggers exist */
#endif

  sContext.pParse = 0;
  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto delete_from_cleanup;
  }
  db = pParse->db;
  assert( pTabList->nSrc==1 );

  /* Locate the table which we want to delete.  This table has to be
  ** put in an SrcList structure because some of the subroutines we

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.248 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

/*
** Set the Expr.span field of the given expression to span all
** text between the two given tokens.
*/
void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
  assert( pRight!=0 );
  assert( pLeft!=0 );
  if( !sqlite3ThreadDataReadOnly()->mallocFailed && pRight->z && pLeft->z ){
    assert( pLeft->dyn==0 || pLeft->z[pLeft->n]==0 );
    if( pLeft->dyn==0 && pRight->dyn==0 ){
      pExpr->span.z = pLeft->z;
      pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
    }else{
      pExpr->span.z = 0;
    }

    if( i>=pParse->nVarExpr ){
      pExpr->iTable = ++pParse->nVar;
      if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
        pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
        sqlite3ReallocOrFree((void**)&pParse->apVarExpr,
                       pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) );
      }
      if( !sqlite3ThreadDataReadOnly()->mallocFailed ){
        assert( pParse->apVarExpr!=0 );
        pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
      }
    }
  } 
}

    if( pOldExpr->span.z!=0 && pNewExpr ){
      /* Always make a copy of the span for top-level expressions in the
      ** expression list.  The logic in SELECT processing that determines
      ** the names of columns in the result set needs this information */
      sqlite3TokenCopy(&pNewExpr->span, &pOldExpr->span);
    }
    assert( pNewExpr==0 || pNewExpr->span.z!=0 
            || pOldExpr->span.z==0
            || sqlite3ThreadDataReadOnly()->mallocFailed );
    pItem->zName = sqliteStrDup(pOldItem->zName);
    pItem->sortOrder = pOldItem->sortOrder;
    pItem->isAgg = pOldItem->isAgg;
    pItem->done = 0;
  }
  return pNew;
}

  struct SrcList_item *pMatch = 0;  /* The matching pSrcList item */
  NameContext *pTopNC = pNC;        /* First namecontext in the list */

  assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
  zDb = sqlite3NameFromToken(pDbToken);
  zTab = sqlite3NameFromToken(pTableToken);
  zCol = sqlite3NameFromToken(pColumnToken);
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto lookupname_end;
  }

  pExpr->iTable = -1;
  while( pNC && cnt==0 ){
    ExprList *pEList;
    SrcList *pSrcList = pNC->pSrcList;

  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
    int mem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
    testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
    assert( testAddr>0 || sqlite3ThreadDataReadOnly()->mallocFailed );
    sqlite3VdbeAddOp(v, OP_MemInt, 1, mem);
  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;
      KeyInfo keyInfo;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.157 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:

  int triggers_exist = 0;     /* True if there are FOR EACH ROW triggers */
#endif

#ifndef SQLITE_OMIT_AUTOINCREMENT
  int counterRowid;     /* Memory cell holding rowid of autoinc counter */
#endif

  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto insert_cleanup;
  }
  db = pParse->db;

  /* Locate the table into which we will be inserting new information.
  */
  assert( pTabList->nSrc==1 );
  zTab = pTabList->a[0].zName;
  if( zTab==0 ) goto insert_cleanup;

    int rc, iInitCode;
    iInitCode = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    iSelectLoop = sqlite3VdbeCurrentAddr(v);
    iInsertBlock = sqlite3VdbeMakeLabel(v);

    /* Resolve the expressions in the SELECT statement and execute it. */
    rc = sqlite3Select(pParse, pSelect, SRT_Subroutine, iInsertBlock,0,0,0,0);
    if( rc || pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
      goto insert_cleanup;
    }

    iCleanup = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Goto, 0, iCleanup);
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: legacy.c,v 1.11 2006/01/11 21:41:22 drh Exp $
*/

#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*

    azCols = 0;
  }

exec_out:
  if( pStmt ) sqlite3_finalize(pStmt);
  if( azCols ) sqliteFree(azCols);

  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    rc = SQLITE_NOMEM;
    sqlite3MallocClearFailed();
  }

  if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){
    *pzErrMsg = malloc(1+strlen(sqlite3_errmsg(db)));
    if( *pzErrMsg ){

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.323 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and

  /* The temp-database schema is allocated differently from the other schema
  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
  ** So it needs to be freed here. Todo: Why not roll the temp schema into
  ** the same sqliteMalloc() as the one that allocates the database 
  ** structure?
  */
  sqliteFree(db->aDb[1].pSchema);

  sqliteFree(db);
  sqlite3MallocAllow();
  sqlite3ReleaseThreadData();
  return SQLITE_OK;
}

/*
** Rollback all database files.
*/
void sqlite3RollbackAll(sqlite3 *db){

/*
** Return UTF-8 encoded English language explanation of the most recent
** error.
*/
const char *sqlite3_errmsg(sqlite3 *db){
  const char *z;
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return sqlite3ErrStr(SQLITE_NOMEM);
  }
  if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE ){
    return sqlite3ErrStr(SQLITE_MISUSE);
  }
  z = (char*)sqlite3_value_text(db->pErr);
  if( z==0 ){

    0, 'c', 0, 'a', 0, 'l', 0, 'l', 0, 'e', 0, 'd', 0, ' ', 
    0, 'o', 0, 'u', 0, 't', 0, ' ', 
    0, 'o', 0, 'f', 0, ' ', 
    0, 's', 0, 'e', 0, 'q', 0, 'u', 0, 'e', 0, 'n', 0, 'c', 0, 'e', 0, 0, 0
  };

  const void *z;
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return (void *)(&outOfMemBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
  }
  if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE ){
    return (void *)(&misuseBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
  }
  z = sqlite3_value_text16(db->pErr);
  if( z==0 ){
    sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
         SQLITE_UTF8, SQLITE_STATIC);
    z = sqlite3_value_text16(db->pErr);
  }
  return z;
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Return the most recent error code generated by an SQLite routine. If NULL is
** passed to this function, we assume a malloc() failed during sqlite3_open().
*/
int sqlite3_errcode(sqlite3 *db){
  if( !db || sqlite3ThreadDataReadOnly()->mallocFailed ){
    return SQLITE_NOMEM;
  }
  if( sqlite3SafetyCheck(db) ){
    return SQLITE_MISUSE;
  }
  return db->errCode;
}

  const char *zFilename, /* Database filename UTF-8 encoded */
  sqlite3 **ppDb         /* OUT: Returned database handle */
){
  sqlite3 *db;
  int rc;
  CollSeq *pColl;

  assert( !sqlite3ThreadDataReadOnly()->mallocFailed );

  /* Allocate the sqlite data structure */
  db = sqliteMalloc( sizeof(sqlite3) );
  if( db==0 ) goto opendb_out;
  db->priorNewRowid = 0;
  db->magic = SQLITE_MAGIC_BUSY;
  db->nDb = 2;

  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb);
    if( rc==SQLITE_OK && *ppDb ){
      rc = sqlite3_exec(*ppDb, "PRAGMA encoding = 'UTF-16'", 0, 0, 0);
    }
  }else{
    assert( sqlite3ThreadDataReadOnly()->mallocFailed );
    sqlite3MallocClearFailed();
  }
  sqlite3ValueFree(pVal);

  return rc;
}
#endif /* SQLITE_OMIT_UTF16 */

  */
  if( pTd->pBtree && !enable ){
    assert( pTd->useSharedData );
    return SQLITE_MISUSE;
  }

  pTd->useSharedData = enable;
  sqlite3ReleaseThreadData();
  return SQLITE_OK;
}
#endif

/*
** This is a convenience routine that makes sure that all thread-specific
** data for this thread has been deallocated.
*/
void sqlite3_thread_cleanup(void){
  ThreadData *pTd = sqlite3ThreadData();
  memset(pTd, 0, sizeof(*pTd));
  sqlite3ReleaseThreadData();
}

int sqlite3OsTempFileName(char*);
int sqlite3OsRandomSeed(char*);
int sqlite3OsSleep(int ms);
int sqlite3OsCurrentTime(double*);
void sqlite3OsEnterMutex(void);
void sqlite3OsLeaveMutex(void);
int sqlite3OsInMutex(void);
ThreadData *sqlite3OsThreadSpecificData(int);
void *sqlite3OsMalloc(int);
void *sqlite3OsRealloc(void *, int);
void sqlite3OsFree(void *);
int sqlite3OsAllocationSize(void *);

/*
** If the SQLITE_ENABLE_REDEF_IO macro is defined, then the OS-layer

  int (*xRandomSeed)(char*);
  int (*xSleep)(int ms);
  int (*xCurrentTime)(double*);

  void (*xEnterMutex)(void);
  void (*xLeaveMutex)(void);
  int (*xInMutex)(void);
  ThreadData *(*xThreadSpecificData)(int);

  void *(*xMalloc)(int);
  void *(*xRealloc)(void *, int);
  void (*xFree)(void *);
  int (*xAllocationSize)(void *);
};

** Return TRUE if we are currently within the mutex and FALSE if not.
*/
int sqlite3UnixInMutex(){
  return inMutex;
}

/*
** If called with allocateFlag==1, then return a pointer to thread
** specific data for the current thread.  Allocate and zero the
** thread-specific data if it does not already exist necessary.
**


** If called with allocateFlag==0, then check the current thread






** specific data.  If it exists and is all zeros, then deallocate it.


** Return a pointer to the thread specific data or NULL if it is
** unallocated.



*/
ThreadData *sqlite3UnixThreadSpecificData(int allocateFlag){
  static const ThreadData zeroData;
#ifdef SQLITE_UNIX_THREADS
  static pthread_key_t key;
  static int keyInit = 0;
  ThreadData *pTsd;

  if( !keyInit ){
    sqlite3OsEnterMutex();
    if( !keyInit ){
      int rc;
      rc = pthread_key_create(&key, 0);
      if( rc ){
        sqlite3OsLeaveMutex();
        return 0;
      }
      keyInit = 1;
    }
    sqlite3OsLeaveMutex();
  }

  pTsd = pthread_getspecific(key);
  if( allocateFlag ){
    if( pTsd==0 ){
      pTsd = sqlite3OsMalloc(sizeof(zeroData));
      if( pTsd ){
        *pTsd = zeroData;
        pthread_setspecific(key, pTsd);
      }
    }
  }else if( pTsd!=0 && memcmp(pTsd, &zeroData, sizeof(zeroData))==0 ){
    sqlite3OsFree(pTsd);
    pthread_setspecific(key, 0);
    pTsd = 0;
  }
  return pTsd;
#else
  static ThreadData *pTsd = 0;
  if( allocateFlag ){
    if( pTsd==0 ){
      pTsd = sqlite3OsMalloc( sizeof(zeroData) );
      if( pTsd ){
        *pTsd = zeroData;
      }
    }
  }else if( pTsd!=0 && memcmp(pTsd, &zeroData, sizeof(zeroData))==0 ){
    sqlite3OsFree(pTsd);
    pTsd = 0;
  }
  return pTsd;
#endif
}

/*
** The following variable, if set to a non-zero value, becomes the result

  if( sqlite3_current_time ){
    *prNow = sqlite3_current_time/86400.0 + 2440587.5;
  }
#endif
  return 0;
}

/*

** If called with allocateFlag==1, then return a pointer to thread
** specific data for the current thread.  Allocate and zero the
** thread-specific data if it does not already exist necessary.
**
** If called with allocateFlag==0, then check the current thread
** specific data.  If it exists and is all zeros, then deallocate it.
** Return a pointer to the thread specific data or NULL if it is
** unallocated.
*/
void *sqlite3WinThreadSpecificData(int allocateFlag){
  static void *pTsd = 0;
  static int key;
  static int keyInit = 0;
  static const ThreadData zeroData;

  if( !keyInit ){
    sqlite3OsEnterMutex();
    if( !keyInit ){
      key = TlsAlloc();
      if( key==0xffffffff ){
        sqlite3OsLeaveMutex();
        return 0;
      }
      keyInit = 1;
    }
    sqlite3OsLeaveMutex();
  }
  pTsd = TlsGetValue(key);
  if( allocateFlag ){
    if( !pTsd ){
      pTsd = sqlite3OsMalloc(nByte);
      if( pTsd ){
        *pTsd = zeroData;
        TlsSetValue(key, pTsd);
      }
    }
  }else if( pTsd!=0 && memcmp(pTsd, &zeroData, sizeof(zeroData))==0 ){
    sqlite3OsFree(pTsd);
    TlsSetValue(key, 0);
    pTsd = 0;
  }
  return pTsd;
}
#endif /* OS_WIN */

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.236 2006/01/11 21:41:22 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  int nRead,nWrite;           /* Database pages read/written */
#endif
  void (*xDestructor)(void*,int); /* Call this routine when freeing pages */
  void (*xReiniter)(void*,int);   /* Call this routine when reloading pages */
  void (*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
  void *pCodecArg;            /* First argument to xCodec() */
  PgHdr *aHash[N_PG_HASH];    /* Hash table to map page number to PgHdr */
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  Pager *pNext;               /* Linked list of pagers in this thread */
#endif
};

/*
** If SQLITE_TEST is defined then increment the variable given in
** the argument

  int i;
  int tempFile = 0;
  int memDb = 0;
  int readOnly = 0;
  int useJournal = (flags & PAGER_OMIT_JOURNAL)==0;
  int noReadlock = (flags & PAGER_NO_READLOCK)!=0;
  char zTemp[SQLITE_TEMPNAME_SIZE];
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  const ThreadData *pTsdro = sqlite3ThreadDataReadOnly();
#endif

  /* If malloc() has already failed return SQLITE_NOMEM. Before even
  ** testing for this, set *ppPager to NULL so the caller knows the pager
  ** structure was never allocated. 
  */
  *ppPager = 0;
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return SQLITE_NOMEM;
  }
  memset(&fd, 0, sizeof(fd));

  /* Open the pager file and set zFullPathname to point at malloc()ed 
  ** memory containing the complete filename (i.e. including the directory).
  */

  pPager->pFirstSynced = 0;
  pPager->pLast = 0;
  pPager->nExtra = FORCE_ALIGNMENT(nExtra);
  pPager->sectorSize = PAGER_SECTOR_SIZE;
  pPager->pBusyHandler = 0;
  memset(pPager->aHash, 0, sizeof(pPager->aHash));
  *ppPager = pPager;
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( pTsdro->useMemoryManagement ){
    ThreadData *pTsd = sqlite3ThreadData();
    pPager->pNext = pTsd->pPager;
    pTsd->pPager = pPager;
  }
#endif
  return SQLITE_OK;
}

** This function always succeeds. If a transaction is active an attempt
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
int sqlite3pager_close(Pager *pPager){
  PgHdr *pPg, *pNext;
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  const ThreadData *pTsd = sqlite3ThreadDataReadOnly();
#endif

  switch( pPager->state ){
    case PAGER_RESERVED:
    case PAGER_SYNCED: 
    case PAGER_EXCLUSIVE: {
      /* We ignore any IO errors that occur during the rollback

  sqlite3OsClose(&pPager->fd);
  /* Temp files are automatically deleted by the OS
  ** if( pPager->tempFile ){
  **   sqlite3OsDelete(pPager->zFilename);
  ** }
  */

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  /* Remove the pager from the linked list of pagers starting at 
  ** ThreadData.pPager if memory-management is enabled.
  */
  if( pTsd->useMemoryManagement ){
    if( pPager==pTsd->pPager ){
      pTsd->pPager = pPager->pNext;
    }else{

** by the current thread may be sqliteFree()ed.
**
** nReq is the number of bytes of memory required. Once this much has
** been released, the function returns. A negative value for nReq means
** free as much memory as possible. The return value is the total number 
** of bytes of memory released.
*/
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
int sqlite3pager_release_memory(int nReq){
  const ThreadData *pTsdro = sqlite3ThreadDataReadOnly();
  Pager *p;
  int nReleased = 0;
  int i;

  /* If the the global mutex is held, this subroutine becomes a
  ** o-op; zero bytes of memory are freed.  This is because
  ** some of the code invoked by this function may also

  ** iteration (which only runs if the first failed to free nReq bytes of
  ** memory) is permitted to call fsync(). This is of course much more 
  ** expensive.
  */
  for(i=0; i<=1; i++){

    /* Loop through all the SQLite pagers opened by the current thread. */
    for(p=pTsdro->pPager; p && (nReq<0 || nReleased<nReq); p=p->pNext){
      PgHdr *pPg;
      int rc;

      /* For each pager, try to free as many pages as possible (without 
      ** calling fsync() if this is the first iteration of the outermost 
      ** loop).
      */

        pager_error(p, rc);
      }
    }
  }

  return nReleased;
}
#endif /* SQLITE_ENABLE_MEMORY_MANAGEMENT */

/*
** Acquire a page.
**
** A read lock on the disk file is obtained when the first page is acquired. 
** This read lock is dropped when the last page is released.
**

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.20 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(InitData *pData, const char *zExtra){
  if( !sqlite3ThreadDataReadOnly()->mallocFailed ){
    sqlite3SetString(pData->pzErrMsg, "malformed database schema",
       zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0);
  }
}

/*
** This is the callback routine for the code that initializes the

**
*/
int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){
  InitData *pData = (InitData*)pInit;
  sqlite3 *db = pData->db;
  int iDb;

  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return SQLITE_NOMEM;
  }

  assert( argc==4 );
  if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
  if( argv[1]==0 || argv[3]==0 ){
    corruptSchema(pData, 0);

#ifndef SQLITE_OMIT_ANALYZE
    if( rc==SQLITE_OK ){
      sqlite3AnalysisLoad(db, iDb);
    }
#endif
    sqlite3BtreeCloseCursor(curMain);
  }
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    sqlite3SetString(pzErrMsg, "out of memory", (char*)0);
    rc = SQLITE_NOMEM;
    sqlite3ResetInternalSchema(db, 0);
  }
  if( rc==SQLITE_OK ){
    DbSetProperty(db, iDb, DB_SchemaLoaded);
  }else{

  const char** pzTail       /* OUT: End of parsed string */
){
  Parse sParse;
  char *zErrMsg = 0;
  int rc = SQLITE_OK;
  int i;

  assert( !sqlite3ThreadDataReadOnly()->mallocFailed );

  assert( ppStmt );
  *ppStmt = 0;
  if( sqlite3SafetyOn(db) ){
    return SQLITE_MISUSE;
  }

    }
  }
  
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  sqlite3RunParser(&sParse, zSql, &zErrMsg);

  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    sParse.rc = SQLITE_NOMEM;
  }
  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
  if( sParse.checkSchema && !schemaIsValid(db) ){
    sParse.rc = SQLITE_SCHEMA;
  }
  if( sParse.rc==SQLITE_SCHEMA ){

  }else{
    sqlite3Error(db, rc, 0);
  }

  /* We must check for malloc failure last of all, in case malloc() failed
  ** inside of the sqlite3Error() call above or something.
  */
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    rc = SQLITE_NOMEM;
    sqlite3Error(db, rc, 0);
  }

  sqlite3MallocClearFailed();
  return rc;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.293 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.

  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  assert( v!=0 );
  if( pParse->colNamesSet || v==0
     || sqlite3ThreadDataReadOnly()->mallocFailed ) return;
  pParse->colNamesSet = 1;
  fullNames = (db->flags & SQLITE_FullColNames)!=0;
  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
    Expr *p;
    p = pEList->a[i].pExpr;

      /* Use the original text of the column expression as its name */
      zName = sqlite3MPrintf("%T", &p->span);
    }else{
      /* If all else fails, make up a name */
      zName = sqlite3MPrintf("column%d", i+1);
    }
    sqlite3Dequote(zName);
    if( sqlite3ThreadDataReadOnly()->mallocFailed ){
      sqliteFree(zName);
      sqlite3DeleteTable(0, pTab);
      return 0;
    }

    /* Make sure the column name is unique.  If the name is not unique,
    ** append a integer to the name so that it becomes unique.

static int prepSelectStmt(Parse *pParse, Select *p){
  int i, j, k, rc;
  SrcList *pTabList;
  ExprList *pEList;
  Table *pTab;
  struct SrcList_item *pFrom;

  if( p==0 || p->pSrc==0 || sqlite3ThreadDataReadOnly()->mallocFailed ){
    return 1;
  }
  pTabList = p->pSrc;
  pEList = p->pEList;

  /* Make sure cursor numbers have been assigned to all entries in
  ** the FROM clause of the SELECT statement.
  */
  sqlite3SrcListAssignCursors(pParse, p->pSrc);

  int isDistinct;        /* True if the DISTINCT keyword is present */
  int distinct;          /* Table to use for the distinct set */
  int rc = 1;            /* Value to return from this function */
  int addrSortIndex;     /* Address of an OP_OpenVirtual instruction */
  AggInfo sAggInfo;      /* Information used by aggregate queries */
  int iEnd;              /* Address of the end of the query */

  if( p==0 || sqlite3ThreadDataReadOnly()->mallocFailed || pParse->nErr ){
    return 1;
  }
  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
  memset(&sAggInfo, 0, sizeof(sAggInfo));

#ifndef SQLITE_OMIT_COMPOUND_SELECT
  /* If there is are a sequence of queries, do the earlier ones first.
  */
  if( p->pPrior ){

    }
    sAggInfo.nAccumulator = sAggInfo.nColumn;
    for(i=0; i<sAggInfo.nFunc; i++){
      if( sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->pList) ){
        goto select_end;
      }
    }
    if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto select_end;

    /* Processing for aggregates with GROUP BY is very different and
    ** much more complex tha aggregates without a GROUP BY.
    */
    if( pGroupBy ){
      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.155 2006/01/11 21:41:22 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

** This function is only available if the library is compiled without
** the SQLITE_OMIT_SHARED_CACHE macro defined. It is used to enable or
** disable (if the argument is true or false, respectively) the 
** "shared pager" feature.
*/
int sqlite3_enable_shared_cache(int);










/*
** Attempt to free N bytes of heap memory by deallocating non-essential
** memory allocations held by the database library (example: memory 
** used to cache database pages to improve performance).
**
** This function is not a part of standard builds.  It is only created
** if SQLite is compiled with the SQLITE_ENABLE_MEMORY_MANAGEMENT macro.
*/
int sqlite3_release_memory(int);

/*
** Place a "soft" limit on the amount of heap memory that may be allocated by
** SQLite within the current thread. If an internal allocation is requested 
** that would exceed the specified limit, sqlite3_release_memory() is invoked
** one or more times to free up some space before the allocation is made.
**
** The limit is called "soft", because if sqlite3_release_memory() cannot free
** sufficient memory to prevent the limit from being exceeded, the memory is
** allocated anyway and the current operation proceeds.
**
** This function is only available if the library was compiled with the 
** SQLITE_ENABLE_MEMORY_MANAGEMENT option set.
** memory-management has been enabled.
*/
void sqlite3_soft_heap_limit(int);

/*
** This routine makes sure that all thread-local storage has been
** deallocated for the current thread.
**
** This routine is not technically necessary.  All thread-local storage
** will be automatically deallocated once memory-management and
** shared-cache are disabled and the soft heap limit has been set
** to zero.  This routine is provided as a convenience for users who
** want to make absolutely sure they have not forgotten something
** prior to killing off a thread.
*/
void sqlite3_thread_cleanup(void);

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.462 2006/01/11 21:41:22 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/

#endif

#define sqliteFree(x)          sqlite3FreeX(x)
#define sqliteAllocSize(x)     sqlite3AllocSize(x)

/*
** An instance of this structure might be allocated to store information
** specific to a single thread.
**
** To avoid a memory leak on windows, the content of this structure is
** checked at the conclusion of each API call.  If it is all zero, it
** is deallocated.
*/
struct ThreadData {

  u8 mallocFailed;         /* True after a malloc() has failed */

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT

  int nSoftHeapLimit;      /* Suggested max mem allocation.  No limit if <0 */
  int nAlloc;              /* Number of bytes currently allocated */
  Pager *pPager;           /* Linked list of all pagers in this thread */
#endif

#ifndef SQLITE_OMIT_SHARED_CACHE
  u8 useSharedData;        /* True if shared pagers and schemas are enabled */
  BtShared *pBtree;        /* Linked list of all currently open BTrees */
#endif

#ifdef SQLITE_MEMDEBUG
  int nMaxAlloc;           /* High water mark of ThreadData.nAlloc */
  int mallocDisallowed;    /* assert() in sqlite3Malloc() if set */
  int isFail;              /* True if all malloc() calls should fail */
  const char *zFile;       /* Filename to associate debugging info with */
  int iLine;               /* Line number to associate debugging info with */
  void *pFirst;            /* Pointer to linked list of allocations */
#endif
};

void sqlite3Analyze(Parse*, Token*, Token*);
int sqlite3InvokeBusyHandler(BusyHandler*);
int sqlite3FindDb(sqlite3*, Token*);
void sqlite3AnalysisLoad(sqlite3*,int iDB);
void sqlite3DefaultRowEst(Index*);
void sqlite3RegisterLikeFunctions(sqlite3*, int);
int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
ThreadData *sqlite3ThreadData(void);
const ThreadData *sqlite3ThreadDataReadOnly(void);
void sqlite3ReleaseThreadData(void);
void sqlite3AttachFunctions(sqlite3 *);
void sqlite3MinimumFileFormat(Parse*, int, int);
void sqlite3SchemaFree(void *);
Schema *sqlite3SchemaGet(Btree *);
int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.188 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

  ClientData clientData,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int objc,              /* Number of arguments */
  Tcl_Obj *CONST objv[]  /* Command arguments */
){
  extern int sqlite3OutstandingMallocs(Tcl_Interp *interp);

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( objc==2 ){
    const ThreadData *pTd = sqlite3ThreadDataReadOnly();
    const char *zArg = Tcl_GetString(objv[1]);
    if( 0==strcmp(zArg, "-bytes") ){
      Tcl_SetObjResult(interp, Tcl_NewIntObj(pTd->nAlloc));
    }else if( 0==strcmp(zArg, "-maxbytes") ){
      Tcl_SetObjResult(interp, Tcl_NewWideIntObj(pTd->nMaxAlloc));
    }else if( 0==strcmp(zArg, "-clearmaxbytes") ){
      pTd->nMaxAlloc = pTd->nAlloc;

  return sqlite3OutstandingMallocs(interp);
}
#endif

/*
** Usage: sqlite3_enable_shared_cache      BOOLEAN

**
*/
#if !defined(SQLITE_OMIT_SHARED_CACHE)
static int test_enable_shared(
  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 */
){
  int rc;
  int enable;
  int ret = 0;














  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "BOOLEAN");
    return TCL_ERROR;
  }
  if( Tcl_GetBooleanFromObj(interp, objv[1], &enable) ){
    return TCL_ERROR;
  }
  ret = sqlite3ThreadDataReadOnly()->useSharedData;
  rc = sqlite3_enable_shared_cache(enable);
  if( rc!=SQLITE_OK ){
    Tcl_SetResult(interp, (char *)sqlite3ErrStr(rc), TCL_STATIC);
    return TCL_ERROR;
  }
  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(ret));
  return TCL_OK;
}

*/
static int test_release_memory(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
  int N;
  int amt;
  if( objc!=1 && objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?N?");
    return TCL_ERROR;
  }
  if( objc==2 ){

*/
static int test_soft_heap_limit(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
  int amt;
  if( objc!=1 && objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "?N?");
    return TCL_ERROR;
  }
  amt = sqlite3ThreadDataReadOnly()->nSoftHeapLimit;
  if( objc==2 ){
    int N;
    if( Tcl_GetIntFromObj(interp, objv[1], &N) ) return TCL_ERROR;
    sqlite3_soft_heap_limit(N);
  }
  Tcl_SetObjResult(interp, Tcl_NewIntObj(amt));
#endif

#ifdef SQLITE_OMIT_MEMORYDB
  Tcl_SetVar2(interp, "sqlite_options", "memorydb", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "memorydb", "1", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  Tcl_SetVar2(interp, "sqlite_options", "memorymanage", "1", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "memorymanage", "0", TCL_GLOBAL_ONLY);
#endif

#ifdef SQLITE_OMIT_OR_OPTIMIZATION
  Tcl_SetVar2(interp, "sqlite_options", "or_opt", "0", TCL_GLOBAL_ONLY);
#else
  Tcl_SetVar2(interp, "sqlite_options", "or_opt", "1", TCL_GLOBAL_ONLY);
#endif

#endif
#ifdef SQLITE_MEMDEBUG
     { "sqlite_malloc_outstanding", sqlite_malloc_outstanding, 0},
#endif
     { "sqlite3_test_errstr",     test_errstr, 0             },
     { "tcl_variable_type",       tcl_variable_type, 0       },
#ifndef SQLITE_OMIT_SHARED_CACHE
     { "sqlite3_enable_shared_cache", test_enable_shared, 0  },




#endif
  };
  static int bitmask_size = sizeof(Bitmask)*8;
  int i;
  extern int sqlite3_os_trace;
  extern int sqlite3_where_trace;
  extern int sqlite3_sync_count, sqlite3_fullsync_count;

*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.113 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*

  assert( pParse->pNewTable==0 );
  assert( pParse->pNewTrigger==0 );
  assert( pParse->nVar==0 );
  assert( pParse->nVarExpr==0 );
  assert( pParse->nVarExprAlloc==0 );
  assert( pParse->apVarExpr==0 );
  pParse->zTail = pParse->zSql = zSql;
  while( sqlite3ThreadDataReadOnly()->mallocFailed==0 && zSql[i]!=0 ){
    assert( i>=0 );
    pParse->sLastToken.z = (u8*)&zSql[i];
    assert( pParse->sLastToken.dyn==0 );
    pParse->sLastToken.n = getToken((unsigned char*)&zSql[i],&tokenType);
    i += pParse->sLastToken.n;
    switch( tokenType ){
      case TK_SPACE:

    if( lastTokenParsed!=TK_SEMI ){
      sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
      pParse->zTail = &zSql[i];
    }
    sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
  }
  sqlite3ParserFree(pEngine, sqlite3FreeX);
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    pParse->rc = SQLITE_NOMEM;
  }
  if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
    sqlite3SetString(&pParse->zErrMsg, sqlite3ErrStr(pParse->rc), (char*)0);
  }
  if( pParse->zErrMsg ){
    if( pzErrMsg && *pzErrMsg==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( !pTableName || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto trigger_cleanup;
  }
  pTab = sqlite3SrcListLookup(pParse, pTableName);
  if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
    iDb = 1;
  }

  /* Ensure the table name matches database name and that the table exists */
  if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto trigger_cleanup;
  assert( pTableName->nSrc==1 );
  if( sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName) && 
      sqlite3FixSrcList(&sFix, pTableName) ){
    goto trigger_cleanup;
  }
  pTab = sqlite3SrcListLookup(pParse, pTableName);
  if( !pTab ){

  if( db->init.busy ){
    int n;
    Table *pTab;
    Trigger *pDel;
    pDel = sqlite3HashInsert(&db->aDb[iDb].pSchema->trigHash, 
                     pTrig->name, strlen(pTrig->name)+1, pTrig);
    if( pDel ){
      assert( sqlite3ThreadDataReadOnly()->mallocFailed && pDel==pTrig );
      goto triggerfinish_cleanup;
    }
    n = strlen(pTrig->table) + 1;
    pTab = sqlite3HashFind(&pTrig->pTabSchema->tblHash, pTrig->table, n);
    assert( pTab!=0 );
    pTrig->pNext = pTab->pTrigger;
    pTab->pTrigger = pTrig;

  Trigger *pTrigger = 0;
  int i;
  const char *zDb;
  const char *zName;
  int nName;
  sqlite3 *db = pParse->db;

  if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto drop_trigger_cleanup;
  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto drop_trigger_cleanup;
  }

  assert( pName->nSrc==1 );
  zDb = pName->a[0].zDatabase;
  zName = pName->a[0].zName;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.120 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** The most recently coded instruction was an OP_Column to retrieve the
** i-th column of table pTab. This routine sets the P3 parameter of the 
** OP_Column to the default value, if any.

  int triggers_exist = 0;      /* True if any row triggers exist */
#endif

  int newIdx      = -1;  /* index of trigger "new" temp table       */
  int oldIdx      = -1;  /* index of trigger "old" temp table       */

  sContext.pParse = 0;
  if( pParse->nErr || sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto update_cleanup;
  }
  db = pParse->db;
  assert( pTabList->nSrc==1 );

  /* Locate the table which we want to update. 
  */
  pTab = sqlite3SrcListLookup(pParse, pTabList);
  if( pTab==0 ) goto update_cleanup;

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.168 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*

**     * Guardposts to detect overwrites.
**     * Ability to cause a specific Malloc() or Realloc() to fail.
**     * Audit outstanding memory allocations (i.e check for leaks).
*/

#define MAX(x,y) ((x)>(y)?(x):(y))

#if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
/*
** Set the soft heap-size limit for the current thread. Passing a negative
** value indicates no limit.
*/
void sqlite3_soft_heap_limit(int n){
  sqlite3ThreadData()->nSoftHeapLimit = n;
  sqlite3ReleaseThreadData();
}

/*
** Release memory held by SQLite instances created by the current thread.
*/
int sqlite3_release_memory(int n){
  return sqlite3pager_release_memory(n);
}
#else
/* If SQLITE_ENABLE_MEMORY_MANAGEMENT is not defined, then define a version
** of sqlite3_release_memory() to be used by other code in this file.
** This is done for no better reason than to reduce the number of 
** pre-processor #ifndef statements.
*/
#define sqlite3_release_memory(x) 0    /* 0 == no memory freed */
#endif

#endif

/*
** Number of 32-bit guard words.  This should probably be a multiple of
** 2 since on 64-bit machines we want the value returned by sqliteMalloc()
** to be 8-byte aligned.
*/
#ifndef TESTALLOC_NGUARD
# define TESTALLOC_NGUARD 2
#endif

/*
** Size reserved for storing file-name along with each malloc()ed blob.
*/
#define TESTALLOC_FILESIZE 64

/*

}
#endif

/*
** This is the test layer's wrapper around sqlite3OsMalloc().
*/
static void * OSMALLOC(int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  ThreadData *pTsd = sqlite3ThreadData();
  pTsd->nMaxAlloc = MAX(pTsd->nMaxAlloc, pTsd->nAlloc);
#endif
  assert( !sqlite3ThreadData()->mallocDisallowed );
  if( !failMalloc() ){
    u32 *p;
    p = (u32 *)sqlite3OsMalloc(n + TESTALLOC_OVERHEAD);
    assert(p);
    sqlite3_nMalloc++;
    applyGuards(p);
    linkAlloc(p);

  sqlite3_nFree++;
}

/*
** This is the test layer's wrapper around sqlite3OsRealloc().
*/
static void * OSREALLOC(void *pRealloc, int n){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  ThreadData *pTsd = sqlite3ThreadData();
  pTsd->nMaxAlloc = MAX(pTsd->nMaxAlloc, pTsd->nAlloc);
#endif
  assert( !sqlite3ThreadData()->mallocDisallowed );
  if( !failMalloc() ){
    u32 *p = (u32 *)getOsPointer(pRealloc);
    checkGuards(p);
    p = sqlite3OsRealloc(p, n + TESTALLOC_OVERHEAD);
    applyGuards(p);
    relinkAlloc(p);
    return (void *)(&p[TESTALLOC_NGUARD + 2*sizeof(void *)/sizeof(u32)]);

** extra bytes about to be allocated (for Realloc() this means the size of the
** new allocation less the size of the old allocation). If the extra allocation
** means that the total memory allocated to SQLite in this thread would exceed
** the limit set by sqlite3_soft_heap_limit(), then sqlite3_release_memory() is
** called to try to avoid this. No indication of whether or not this is
** successful is returned to the caller.
**
** If SQLITE_ENABLE_MEMORY_MANAGEMENT is not defined, this routine is
** a no-op
*/
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
static void handleSoftLimit(int n){
  ThreadData *pTsd = sqlite3ThreadData();
  pTsd->nAlloc += n;
  assert( pTsd->nAlloc>=0 );
  if( n>0 && pTsd->nSoftHeapLimit>0 ){
    while( pTsd->nAlloc>pTsd->nSoftHeapLimit && sqlite3_release_memory(n) );
  }else if( pTsd->nAlloc==0 && pTsd->nSoftHeapLimit==0 ){
    sqlite3ReleaseThreadData();
  }
}
#else
#define handleSoftLimit(x)
#endif

/*
** Allocate and return N bytes of uninitialised memory by calling
** sqlite3OsMalloc(). If the Malloc() call fails, attempt to free memory 
** by calling sqlite3_release_memory().
*/
void *sqlite3MallocRaw(int n){

  void *p = 0;
  if( n>0 && !sqlite3ThreadDataReadOnly()->mallocFailed ){
    handleSoftLimit(n);
    while( !(p = OSMALLOC(n)) && sqlite3_release_memory(n) );
    if( !p ){
      /* If the allocation failed, call handleSoftLimit() again, this time
      ** with the additive inverse of the argument passed to 
      ** handleSoftLimit() above. This is so the ThreadData.nAlloc variable is
      ** still correct after a malloc() failure. 

/*
** Resize the allocation at p to n bytes by calling sqlite3OsRealloc(). The
** pointer to the new allocation is returned.  If the Realloc() call fails,
** attempt to free memory by calling sqlite3_release_memory().
*/
void *sqlite3Realloc(void *p, int n){

  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return 0;
  }

  if( !p ){
    return sqlite3Malloc(n);
  }else{
    void *np = 0;
    handleSoftLimit(n - OSSIZEOF(p));
    while( !(np = OSREALLOC(p, n)) && sqlite3_release_memory(n) );
    if( !np ){
      /* If the allocation failed, call handleSoftLimit() again, this time
      ** with the additive inverse of the argument passed to 
      ** handleSoftLimit() above. This is so the ThreadData.nAlloc variable is
      ** still correct after a malloc() failure. 
      */
      handleSoftLimit(OSSIZEOF(p) - n);
      sqlite3ThreadData()->mallocFailed = 1;
      OSMALLOC_FAILED();
    }
    return np;
  }
}

/*

}
#endif

/*
** Return a pointer to the ThreadData associated with the calling thread.
*/
ThreadData *sqlite3ThreadData(){
  return (ThreadData*)sqlite3OsThreadSpecificData(1);
}



/*
** Return a pointer to the ThreadData associated with the calling thread.
** If no ThreadData has been allocated to this thread yet, return a pointer
** to a substitute ThreadData structure that is all zeros. 

*/
const ThreadData *sqlite3ThreadDataReadOnly(){
  static const ThreadData zeroData;
  const ThreadData *pTd = sqlite3OsThreadSpecificData(0);
  return pTd ? pTd : &zeroData;
}

/*
** Check to see if the ThreadData for this thread is all zero.  If it
** is, then deallocate it. 
*/
void sqlite3ReleaseThreadData(){
  sqlite3OsThreadSpecificData(0);
}

/*
** Clear the "mallocFailed" flag. This should be invoked before exiting any
** entry points that may have called sqliteMalloc().
*/
void sqlite3MallocClearFailed(){
  ThreadData *pTd = sqlite3OsThreadSpecificData(0);
  if( pTd && pTd->mallocFailed ){

    pTd->mallocFailed = 0;






    sqlite3OsThreadSpecificData(0);







  }


}


#ifndef NDEBUG
/*
** This function sets a flag in the thread-specific-data structure that will
** cause an assert to fail if sqliteMalloc() or sqliteRealloc() is called.
*/
void sqlite3MallocDisallow(){
  assert(!sqlite3ThreadData()->mallocDisallowed);
  sqlite3ThreadData()->mallocDisallowed = 1;
}

/*
** This function clears the flag set in the thread-specific-data structure set
** by sqlite3MallocDisallow().
*/
void sqlite3MallocAllow(){
  assert(sqlite3ThreadData()->mallocDisallowed);
  sqlite3ThreadData()->mallocDisallowed = 0;
}
#endif

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.523 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

  }
  p->resOnStack = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  for(pc=p->pc; rc==SQLITE_OK; pc++){
    assert( pc>=0 && pc<p->nOp );
    assert( pTos<=&p->aStack[pc] );
    if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto no_mem;
#ifdef VDBE_PROFILE
    origPc = pc;
    start = hwtime();
#endif
    pOp = &p->aOp[pc];

    /* Only allow tracing if SQLITE_DEBUG is defined.

    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3;
  }
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  (*ctx.pFunc->xFunc)(&ctx, n, apVal);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( sqlite3ThreadDataReadOnly()->mallocFailed ) goto no_mem;
  popStack(&pTos, n);

  /* If any auxilary data functions have been called by this user function,
  ** immediately call the destructor for any non-static values.
  */
  if( ctx.pVdbeFunc ){
    sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);

  zSql = sqlite3MPrintf(
     "SELECT name, rootpage, sql, %d FROM '%q'.%s WHERE %s",
     pOp->p1, db->aDb[iDb].zName, zMaster, pOp->p3);
  if( zSql==0 ) goto no_mem;
  sqlite3SafetyOff(db);
  assert( db->init.busy==0 );
  db->init.busy = 1;
  assert(0==sqlite3ThreadDataReadOnly()->mallocFailed);
  rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
  sqliteFree(zSql);
  db->init.busy = 0;
  sqlite3SafetyOn(db);
  if( rc==SQLITE_NOMEM ){
    sqlite3ThreadData()->mallocFailed = 1;
    goto no_mem;

  /* Fall thru into abort_due_to_error */

  /* Jump to here for any other kind of fatal error.  The "rc" variable
  ** should hold the error number.
  */
abort_due_to_error:
  if( p->zErrMsg==0 ){
    if( sqlite3ThreadDataReadOnly()->mallocFailed ) rc = SQLITE_NOMEM;
    sqlite3SetString(&p->zErrMsg, sqlite3ErrStr(rc), (char*)0);
  }
  goto vdbe_halt;

  /* Jump to here if the sqlite3_interrupt() API sets the interrupt
  ** flag.
  */

** statement is completely executed or an error occurs.
*/
int sqlite3_step(sqlite3_stmt *pStmt){
  Vdbe *p = (Vdbe*)pStmt;
  sqlite3 *db;
  int rc;

  assert(!sqlite3ThreadDataReadOnly()->mallocFailed);

  if( p==0 || p->magic!=VDBE_MAGIC_RUN ){
    return SQLITE_MISUSE;
  }
  if( p->aborted ){
    return SQLITE_ABORT;
  }

static void columnMallocFailure(sqlite3_stmt *pStmt)
{
  /* If malloc() failed during an encoding conversion within an
  ** sqlite3_column_XXX API, then set the return code of the statement to
  ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
  ** and _finalize() will return NOMEM.
  */
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    ((Vdbe *)pStmt)->rc = SQLITE_NOMEM;
    sqlite3MallocClearFailed();
  }
}

/**************************** sqlite3_column_  *******************************
** The following routines are used to access elements of the current row

  int i;
  VdbeOp *pOp;

  i = p->nOp;
  p->nOp++;
  assert( p->magic==VDBE_MAGIC_INIT );
  resizeOpArray(p, i+1);
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return 0;
  }
  pOp = &p->aOp[i];
  pOp->opcode = op;
  pOp->p1 = p1;
  pOp->p2 = p2;
  pOp->p3 = 0;

** Add a whole list of operations to the operation stack.  Return the
** address of the first operation added.
*/
int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
  int addr;
  assert( p->magic==VDBE_MAGIC_INIT );
  resizeOpArray(p, p->nOp + nOp);
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    return 0;
  }
  addr = p->nOp;
  if( nOp>0 ){
    int i;
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){

** the Vdbe. In these cases we can just copy the pointer.
**
** If addr<0 then change P3 on the most recently inserted instruction.
*/
void sqlite3VdbeChangeP3(Vdbe *p, int addr, const char *zP3, int n){
  Op *pOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p==0 || p->aOp==0 || sqlite3ThreadDataReadOnly()->mallocFailed ){
    if (n != P3_KEYINFO) {
      freeP3(n, (void*)*(char**)&zP3);
    }
    return;
  }
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;

/*
** Replace the P3 field of the most recently coded instruction with
** comment text.
*/
void sqlite3VdbeComment(Vdbe *p, const char *zFormat, ...){
  va_list ap;
  assert( p->nOp>0 );
  assert( p->aOp==0 || p->aOp[p->nOp-1].p3==0 
          || sqlite3ThreadDataReadOnly()->mallocFailed );
  va_start(ap, zFormat);
  sqlite3VdbeChangeP3(p, -1, sqlite3VMPrintf(zFormat, ap), P3_DYNAMIC);
  va_end(ap);
}
#endif

/*

        nStack*sizeof(p->aStack[0])    /* aStack */
      + nArg*sizeof(Mem*)              /* apArg */
      + nVar*sizeof(Mem)               /* aVar */
      + nVar*sizeof(char*)             /* azVar */
      + nMem*sizeof(Mem)               /* aMem */
      + nCursor*sizeof(Cursor*)        /* apCsr */
    );
    if( !sqlite3ThreadDataReadOnly()->mallocFailed ){
      p->aMem = &p->aStack[nStack];
      p->nMem = nMem;
      p->aVar = &p->aMem[nMem];
      p->nVar = nVar;
      p->okVar = 0;
      p->apArg = (Mem**)&p->aVar[nVar];
      p->azVar = (char**)&p->apArg[nArg];

** the string is freed using sqliteFree() when the vdbe is finished with
** it. Otherwise, N bytes of zName are copied.
*/
int sqlite3VdbeSetColName(Vdbe *p, int idx, const char *zName, int N){
  int rc;
  Mem *pColName;
  assert( idx<(2*p->nResColumn) );
  if( sqlite3ThreadDataReadOnly()->mallocFailed ) return SQLITE_NOMEM;
  assert( p->aColName!=0 );
  pColName = &(p->aColName[idx]);
  if( N==P3_DYNAMIC || N==P3_STATIC ){
    rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, SQLITE_STATIC);
  }else{
    rc = sqlite3VdbeMemSetStr(pColName, zName, N, SQLITE_UTF8,SQLITE_TRANSIENT);
  }

** means the close did not happen and needs to be repeated.
*/
int sqlite3VdbeHalt(Vdbe *p){
  sqlite3 *db = p->db;
  int i;
  int (*xFunc)(Btree *pBt) = 0;  /* Function to call on each btree backend */

  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    p->rc = SQLITE_NOMEM;
  }

  if( p->magic!=VDBE_MAGIC_RUN ){
    /* Already halted.  Nothing to do. */
    assert( p->magic==VDBE_MAGIC_HALT );
    return SQLITE_OK;

    return 0;
  }
  if( pVal->flags&MEM_Str ){
    sqlite3VdbeChangeEncoding(pVal, enc);
  }else if( !(pVal->flags&MEM_Blob) ){
    sqlite3VdbeMemStringify(pVal, enc);
  }
  assert(pVal->enc==enc || sqlite3ThreadDataReadOnly()->mallocFailed);
  return (const void *)(pVal->enc==enc ? (pVal->z) : 0);
}

/*
** Create a new sqlite3_value object.
*/
sqlite3_value* sqlite3ValueNew(void){

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.194 2006/01/11 21:41:22 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

  WhereTerm *pTerm = &pWC->a[idxTerm];
  Expr *pExpr = pTerm->pExpr;
  Bitmask prereqLeft;
  Bitmask prereqAll;
  int nPattern;
  int isComplete;

  if( sqlite3ThreadDataReadOnly()->mallocFailed ) return;
  prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
  if( pExpr->op==TK_IN ){
    assert( pExpr->pRight==0 );
    pTerm->prereqRight = exprListTableUsage(pMaskSet, pExpr->pList)
                          | exprSelectTableUsage(pMaskSet, pExpr->pSelect);
  }else{
    pTerm->prereqRight = exprTableUsage(pMaskSet, pExpr->pRight);

  whereClauseInit(&wc, pParse);
  whereSplit(&wc, pWhere, TK_AND);
    
  /* Allocate and initialize the WhereInfo structure that will become the
  ** return value.
  */
  pWInfo = sqliteMalloc( sizeof(WhereInfo) + pTabList->nSrc*sizeof(WhereLevel));
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto whereBeginNoMem;
  }
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);

  /* Special case: a WHERE clause that is constant.  Evaluate the

  ** want to analyze these virtual terms, so start analyzing at the end
  ** and work forward so that the added virtual terms are never processed.
  */
  for(i=0; i<pTabList->nSrc; i++){
    createMask(&maskSet, pTabList->a[i].iCursor);
  }
  exprAnalyzeAll(pTabList, &maskSet, &wc);
  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
    goto whereBeginNoMem;
  }

  /* Chose the best index to use for each table in the FROM clause.
  **
  ** This loop fills in the following fields:
  **