Immediately purge entries from the column cache when the associated register

undergoes an affinity change.  Ticket [eb5548a849].  Enhance the
SQLITE_TESTCTRL_OPTIMIZATIONS setting of sqlite3_test_control so that it
can disable the column cache for testing purposes, in an effort to prevent
future problems of a similar nature to this one.

FossilOrigin-Name: ea4e57e1c1b6663ceb12872e31a8503f6c14e3d8

1 files changed, 25 insertions, 49 deletions

diff --git a/src/expr.c b/src/expr.c
index aee2b7409..7e9eb4170 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -228,30 +228,6 @@ CollSeq *sqlite3BinaryCompareCollSeq(
 }
 
 /*
-** Generate the operands for a comparison operation.  Before
-** generating the code for each operand, set the EP_AnyAff
-** flag on the expression so that it will be able to used a
-** cached column value that has previously undergone an
-** affinity change.
-*/
-static void codeCompareOperands(
-  Parse *pParse,    /* Parsing and code generating context */
-  Expr *pLeft,      /* The left operand */
-  int *pRegLeft,    /* Register where left operand is stored */
-  int *pFreeLeft,   /* Free this register when done */
-  Expr *pRight,     /* The right operand */
-  int *pRegRight,   /* Register where right operand is stored */
-  int *pFreeRight   /* Write temp register for right operand there */
-){
-  while( pLeft->op==TK_UPLUS ) pLeft = pLeft->pLeft;
-  pLeft->flags |= EP_AnyAff;
-  *pRegLeft = sqlite3ExprCodeTemp(pParse, pLeft, pFreeLeft);
-  while( pRight->op==TK_UPLUS ) pRight = pRight->pLeft;
-  pRight->flags |= EP_AnyAff;
-  *pRegRight = sqlite3ExprCodeTemp(pParse, pRight, pFreeRight);
-}
-
-/*
 ** Generate code for a comparison operator.
 */
 static int codeCompare(
@@ -1982,13 +1958,18 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
   assert( iReg>0 );  /* Register numbers are always positive */
   assert( iCol>=-1 && iCol<32768 );  /* Finite column numbers */
 
+  /* The SQLITE_ColumnCache flag disables the column cache.  This is used
+  ** for testing only - to verify that SQLite always gets the same answer
+  ** with and without the column cache.
+  */
+  if( pParse->db->flags & SQLITE_ColumnCache ) return;
+
   /* First replace any existing entry */
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
     if( p->iReg && p->iTable==iTab && p->iColumn==iCol ){
       cacheEntryClear(pParse, p);
       p->iLevel = pParse->iCacheLevel;
       p->iReg = iReg;
-      p->affChange = 0;
       p->lru = pParse->iCacheCnt++;
       return;
     }
@@ -2001,7 +1982,6 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
       p->iTable = iTab;
       p->iColumn = iCol;
       p->iReg = iReg;
-      p->affChange = 0;
       p->tempReg = 0;
       p->lru = pParse->iCacheCnt++;
       return;
@@ -2023,7 +2003,6 @@ void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
     p->iTable = iTab;
     p->iColumn = iCol;
     p->iReg = iReg;
-    p->affChange = 0;
     p->tempReg = 0;
     p->lru = pParse->iCacheCnt++;
     return;
@@ -2109,16 +2088,14 @@ 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 allowAffChng /* True if prior affinity changes are OK */
+  int iReg         /* Store results here */
 ){
   Vdbe *v = pParse->pVdbe;
   int i;
   struct yColCache *p;
 
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
-    if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn
-           && (!p->affChange || allowAffChng) ){
+    if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
       p->lru = pParse->iCacheCnt++;
       sqlite3ExprCachePinRegister(pParse, p->iReg);
       return p->iReg;
@@ -2162,7 +2139,8 @@ void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
   for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
     int r = p->iReg;
     if( r>=iStart && r<=iEnd ){
-      p->affChange = 1;
+      cacheEntryClear(pParse, p);
+      p->iReg = 0;
     }
   }
 }
@@ -2329,10 +2307,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
         assert( pParse->ckBase>0 );
         inReg = pExpr->iColumn + pParse->ckBase;
       }else{
-        testcase( (pExpr->flags & EP_AnyAff)!=0 );
         inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
-                                 pExpr->iColumn, pExpr->iTable, target,
-                                 pExpr->flags & EP_AnyAff);
+                                 pExpr->iColumn, pExpr->iTable, target);
       }
       break;
     }
@@ -2449,8 +2425,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       testcase( op==TK_GE );
       testcase( op==TK_EQ );
       testcase( op==TK_NE );
-      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
-                                  pExpr->pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, inReg, SQLITE_STOREP2);
       testcase( regFree1==0 );
@@ -2461,8 +2437,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
     case TK_ISNOT: {
       testcase( op==TK_IS );
       testcase( op==TK_ISNOT );
-      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
-                                  pExpr->pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       op = (op==TK_IS) ? TK_EQ : TK_NE;
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, inReg, SQLITE_STOREP2 | SQLITE_NULLEQ);
@@ -2702,8 +2678,8 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       struct ExprList_item *pLItem = pExpr->x.pList->a;
       Expr *pRight = pLItem->pExpr;
 
-      codeCompareOperands(pParse, pLeft, &r1, &regFree1,
-                                  pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pRight, &regFree2);
       testcase( regFree1==0 );
       testcase( regFree2==0 );
       r3 = sqlite3GetTempReg(pParse);
@@ -3238,8 +3214,8 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
       testcase( op==TK_EQ );
       testcase( op==TK_NE );
       testcase( jumpIfNull==0 );
-      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
-                                  pExpr->pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, dest, jumpIfNull);
       testcase( regFree1==0 );
@@ -3250,8 +3226,8 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
     case TK_ISNOT: {
       testcase( op==TK_IS );
       testcase( op==TK_ISNOT );
-      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
-                                  pExpr->pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       op = (op==TK_IS) ? TK_EQ : TK_NE;
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, dest, SQLITE_NULLEQ);
@@ -3381,8 +3357,8 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
       testcase( op==TK_EQ );
       testcase( op==TK_NE );
       testcase( jumpIfNull==0 );
-      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
-                                  pExpr->pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, dest, jumpIfNull);
       testcase( regFree1==0 );
@@ -3393,8 +3369,8 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
     case TK_ISNOT: {
       testcase( pExpr->op==TK_IS );
       testcase( pExpr->op==TK_ISNOT );
-      codeCompareOperands(pParse, pExpr->pLeft, &r1, &regFree1,
-                                  pExpr->pRight, &r2, &regFree2);
+      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
+      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                   r1, r2, dest, SQLITE_NULLEQ);