track 3.7.12

2026-08-31 06:21:07 +00:00 · 2012-05-15 19:05:34 -04:00
parent d09051a1f2
commit c8c482ab80
214 changed files with 13008 additions and 2633 deletions
@@ -484,23 +484,55 @@ Expr *sqlite3PExpr(
  Expr *pRight,           /* Right operand */
  const Token *pToken     /* Argument token */
 ){
-  Expr *p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
-  sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
+  Expr *p;
+  if( op==TK_AND && pLeft && pRight ){
+    /* Take advantage of short-circuit false optimization for AND */
+    p = sqlite3ExprAnd(pParse->db, pLeft, pRight);
+  }else{
+    p = sqlite3ExprAlloc(pParse->db, op, pToken, 1);
+    sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
+  }
  if( p ) {
    sqlite3ExprCheckHeight(pParse, p->nHeight);
  }
  return p;
 }

+/*
+** Return 1 if an expression must be FALSE in all cases and 0 if the
+** expression might be true.  This is an optimization.  If is OK to
+** return 0 here even if the expression really is always false (a 
+** false negative).  But it is a bug to return 1 if the expression
+** might be true in some rare circumstances (a false positive.)
+**
+** Note that if the expression is part of conditional for a
+** LEFT JOIN, then we cannot determine at compile-time whether or not
+** is it true or false, so always return 0.
+*/
+static int exprAlwaysFalse(Expr *p){
+  int v = 0;
+  if( ExprHasProperty(p, EP_FromJoin) ) return 0;
+  if( !sqlite3ExprIsInteger(p, &v) ) return 0;
+  return v==0;
+}
+
 /*
 ** Join two expressions using an AND operator.  If either expression is
 ** NULL, then just return the other expression.
+**
+** If one side or the other of the AND is known to be false, then instead
+** of returning an AND expression, just return a constant expression with
+** a value of false.
 */
 Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
  if( pLeft==0 ){
    return pRight;
  }else if( pRight==0 ){
    return pLeft;
+  }else if( exprAlwaysFalse(pLeft) || exprAlwaysFalse(pRight) ){
+    sqlite3ExprDelete(db, pLeft);
+    sqlite3ExprDelete(db, pRight);
+    return sqlite3ExprAlloc(db, TK_INTEGER, &sqlite3IntTokens[0], 0);
  }else{
    Expr *pNew = sqlite3ExprAlloc(db, TK_AND, 0, 0);
    sqlite3ExprAttachSubtrees(db, pNew, pLeft, pRight);
@@ -856,8 +888,9 @@ ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->iECursor = 0;
-  pNew->nExpr = pNew->nAlloc = p->nExpr;
-  pNew->a = pItem = sqlite3DbMallocRaw(db,  p->nExpr*sizeof(p->a[0]) );
+  pNew->nExpr = i = p->nExpr;
+  if( (flags & EXPRDUP_REDUCE)==0 ) for(i=1; i<p->nExpr; i+=i){}
+  pNew->a = pItem = sqlite3DbMallocRaw(db,  i*sizeof(p->a[0]) );
  if( pItem==0 ){
    sqlite3DbFree(db, pNew);
    return 0;
@@ -925,12 +958,15 @@ IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
  if( p==0 ) return 0;
  pNew = sqlite3DbMallocRaw(db, sizeof(*pNew) );
  if( pNew==0 ) return 0;
-  pNew->nId = pNew->nAlloc = p->nId;
+  pNew->nId = p->nId;
  pNew->a = sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
  if( pNew->a==0 ){
    sqlite3DbFree(db, pNew);
    return 0;
  }
+  /* Note that because the size of the allocation for p->a[] is not
+  ** necessarily a power of two, sqlite3IdListAppend() may not be called
+  ** on the duplicate created by this function. */
  for(i=0; i<p->nId; i++){
    struct IdList_item *pNewItem = &pNew->a[i];
    struct IdList_item *pOldItem = &p->a[i];
@@ -992,17 +1028,16 @@ ExprList *sqlite3ExprListAppend(
    if( pList==0 ){
      goto no_mem;
    }
-    assert( pList->nAlloc==0 );
-  }
-  if( pList->nAlloc<=pList->nExpr ){
+    pList->a = sqlite3DbMallocRaw(db, sizeof(pList->a[0]));
+    if( pList->a==0 ) goto no_mem;
+  }else if( (pList->nExpr & (pList->nExpr-1))==0 ){
    struct ExprList_item *a;
-    int n = pList->nAlloc*2 + 4;
-    a = sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
+    assert( pList->nExpr>0 );
+    a = sqlite3DbRealloc(db, pList->a, pList->nExpr*2*sizeof(pList->a[0]));
    if( a==0 ){
      goto no_mem;
    }
    pList->a = a;
-    pList->nAlloc = sqlite3DbMallocSize(db, a)/sizeof(a[0]);
  }
  assert( pList->a!=0 );
  if( 1 ){
@@ -1093,8 +1128,7 @@ void sqlite3ExprListDelete(sqlite3 *db, ExprList *pList){
  int i;
  struct ExprList_item *pItem;
  if( pList==0 ) return;
-  assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
-  assert( pList->nExpr<=pList->nAlloc );
+  assert( pList->a!=0 || pList->nExpr==0 );
  for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
    sqlite3ExprDelete(db, pItem->pExpr);
    sqlite3DbFree(db, pItem->zName);
@@ -2030,15 +2064,6 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
  */
 #ifndef NDEBUG
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
-#if 0 /* This code wold remove the entry from the cache if it existed */
-    if( p->iReg && p->iTable==iTab && p->iColumn==iCol ){
-      cacheEntryClear(pParse, p);
-      p->iLevel = pParse->iCacheLevel;
-      p->iReg = iReg;
-      p->lru = pParse->iCacheCnt++;
-      return;
-    }
-#endif
    assert( p->iReg==0 || p->iTable!=iTab || p->iColumn!=iCol );
  }
 #endif
@@ -2173,7 +2198,8 @@ int sqlite3ExprCodeGetColumn(
  Table *pTab,     /* Description of the table we are reading from */
  int iColumn,     /* Index of the table column */
  int iTable,      /* The cursor pointing to the table */
-  int iReg         /* Store results here */
+  int iReg,        /* Store results here */
+  u8 p5            /* P5 value for OP_Column */
 ){
  Vdbe *v = pParse->pVdbe;
  int i;
@@ -2188,7 +2214,11 @@ int sqlite3ExprCodeGetColumn(
  }  
  assert( v!=0 );
  sqlite3ExprCodeGetColumnOfTable(v, pTab, iTable, iColumn, iReg);
-  sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
+  if( p5 ){
+    sqlite3VdbeChangeP5(v, p5);
+  }else{   
+    sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);
+  }
  return iReg;
 }

@@ -2316,7 +2346,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
        inReg = pExpr->iColumn + pParse->ckBase;
      }else{
        inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
-                                 pExpr->iColumn, pExpr->iTable, target);
+                                 pExpr->iColumn, pExpr->iTable, target,
+                                 pExpr->op2);
      }
      break;
    }
@@ -2593,6 +2624,25 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){

      if( pFarg ){
        r1 = sqlite3GetTempRange(pParse, nFarg);
+
+        /* For length() and typeof() functions with a column argument,
+        ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
+        ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
+        ** loading.
+        */
+        if( (pDef->flags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){
+          u8 exprOp;
+          assert( nFarg==1 );
+          assert( pFarg->a[0].pExpr!=0 );
+          exprOp = pFarg->a[0].pExpr->op;
+          if( exprOp==TK_COLUMN || exprOp==TK_AGG_COLUMN ){
+            assert( SQLITE_FUNC_LENGTH==OPFLAG_LENGTHARG );
+            assert( SQLITE_FUNC_TYPEOF==OPFLAG_TYPEOFARG );
+            testcase( pDef->flags==SQLITE_FUNC_LENGTH );
+            pFarg->a[0].pExpr->op2 = pDef->flags;
+          }
+        }
+
        sqlite3ExprCachePush(pParse);     /* Ticket 2ea2425d34be */
        sqlite3ExprCodeExprList(pParse, pFarg, r1, 1);
        sqlite3ExprCachePop(pParse, 1);   /* Ticket 2ea2425d34be */
@@ -3728,7 +3778,7 @@ int sqlite3ExprCompare(Expr *pA, Expr *pB){
    if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
      return 2;
    }
-  }else if( pA->op!=TK_COLUMN && pA->u.zToken ){
+  }else if( pA->op!=TK_COLUMN && pA->op!=TK_AGG_COLUMN && pA->u.zToken ){
    if( ExprHasProperty(pB, EP_IntValue) || NEVER(pB->u.zToken==0) ) return 2;
    if( strcmp(pA->u.zToken,pB->u.zToken)!=0 ){
      return 2;
@@ -3765,6 +3815,41 @@ int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
  return 0;
 }

+/*
+** This is the expression callback for sqlite3FunctionUsesOtherSrc().
+**
+** Determine if an expression references any table other than one of the
+** tables in pWalker->u.pSrcList and abort if it does.
+*/
+static int exprUsesOtherSrc(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
+    int i;
+    SrcList *pSrc = pWalker->u.pSrcList;
+    for(i=0; i<pSrc->nSrc; i++){
+      if( pExpr->iTable==pSrc->a[i].iCursor ) return WRC_Continue;
+    }
+    return WRC_Abort;
+  }else{
+    return WRC_Continue;
+  }
+}
+
+/*
+** Determine if any of the arguments to the pExpr Function references
+** any SrcList other than pSrcList.  Return true if they do.  Return
+** false if pExpr has no argument or has only constant arguments or
+** only references tables named in pSrcList.
+*/
+static int sqlite3FunctionUsesOtherSrc(Expr *pExpr, SrcList *pSrcList){
+  Walker w;
+  assert( pExpr->op==TK_AGG_FUNCTION );
+  memset(&w, 0, sizeof(w));
+  w.xExprCallback = exprUsesOtherSrc;
+  w.u.pSrcList = pSrcList;
+  if( sqlite3WalkExprList(&w, pExpr->x.pList)!=WRC_Continue ) return 1;
+  return 0;
+}
+
 /*
 ** Add a new element to the pAggInfo->aCol[] array.  Return the index of
 ** the new element.  Return a negative number if malloc fails.
@@ -3775,9 +3860,7 @@ static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
       db,
       pInfo->aCol,
       sizeof(pInfo->aCol[0]),
-       3,
       &pInfo->nColumn,
-       &pInfo->nColumnAlloc,
       &i
  );
  return i;
@@ -3793,9 +3876,7 @@ static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
       db, 
       pInfo->aFunc,
       sizeof(pInfo->aFunc[0]),
-       3,
       &pInfo->nFunc,
-       &pInfo->nFuncAlloc,
       &i
  );
  return i;
@@ -3884,9 +3965,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
      return WRC_Prune;
    }
    case TK_AGG_FUNCTION: {
-      /* The pNC->nDepth==0 test causes aggregate functions in subqueries
-      ** to be ignored */
-      if( pNC->nDepth==0 ){
+      if( !sqlite3FunctionUsesOtherSrc(pExpr, pSrcList) ){
        /* Check to see if pExpr is a duplicate of another aggregate 
        ** function that is already in the pAggInfo structure
        */
@@ -3930,15 +4009,9 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
  return WRC_Continue;
 }
 static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
-  NameContext *pNC = pWalker->u.pNC;
-  if( pNC->nDepth==0 ){
-    pNC->nDepth++;
-    sqlite3WalkSelect(pWalker, pSelect);
-    pNC->nDepth--;
-    return WRC_Prune;
-  }else{
-    return WRC_Continue;
-  }
+  UNUSED_PARAMETER(pWalker);
+  UNUSED_PARAMETER(pSelect);
+  return WRC_Continue;
 }

 /*
@@ -3951,6 +4024,7 @@ static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
 */
 void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
  Walker w;
+  memset(&w, 0, sizeof(w));
  w.xExprCallback = analyzeAggregate;
  w.xSelectCallback = analyzeAggregatesInSelect;
  w.u.pNC = pNC;