Reduce the size of the stack required by the codeOneLoopStart() function in

where.c.

FossilOrigin-Name: eb6d4278b8516e0571269049d1eaa55066f51b1a

manifest

@@ -1,5 +1,5 @@
-C For\sthe\sMSVC\smakefile,\srecompile\svdbe.lo\sand\sparse.lo\sfirst.
-D 2013-07-29T19:03:20.408
+C Reduce\sthe\ssize\sof\sthe\sstack\srequired\sby\sthe\scodeOneLoopStart()\sfunction\sin\nwhere.c.
+D 2013-07-30T15:10:32.747
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -290,7 +290,7 @@ F src/vtab.c 2e8b489db47e20ae36cd247932dc671c9ded0624
 F src/wal.c 7dc3966ef98b74422267e7e6e46e07ff6c6eb1b4
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 4fa43583d0a84b48f93b1e88f11adf2065be4e73
-F src/where.c 1a26c37b7b54d198e2ec9aa127d22c3dcfe89de8
+F src/where.c a55e27475c3d4c72c8bf1aaf9ece70e47e8731cf
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -1103,7 +1103,7 @@ F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P c0809b5e32c2ca0600098447a573e718eaeb319f
-R acca2317d80cadebf01ca0291e013836
-U mistachkin
-Z 6eb4dac3f80be1a20108b92a7b5da831
+P 9e819f0f12b6f2a8e0e7a90251b3115ff1595f25
+R 8a77f3488eeca7f033bc07ab4b9db562
+U drh
+Z 51b3ad13ced3eb326ea64314852a899d

manifest.uuid

@@ -1 +1 @@
-9e819f0f12b6f2a8e0e7a90251b3115ff1595f25
+eb6d4278b8516e0571269049d1eaa55066f51b1a

src/where.c

@@ -3250,6 +3250,7 @@ static Bitmask codeOneLoopStart(
   WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
   WhereTerm *pTerm;               /* A WHERE clause term */
   Parse *pParse;                  /* Parsing context */
+  sqlite3 *db;                    /* Database connection */
   Vdbe *v;                        /* The prepared stmt under constructions */
   struct SrcList_item *pTabItem;  /* FROM clause term being coded */
   int addrBrk;                    /* Jump here to break out of the loop */
@@ -3261,6 +3262,7 @@ static Bitmask codeOneLoopStart(
   pParse = pWInfo->pParse;
   v = pParse->pVdbe;
   pWC = &pWInfo->sWC;
+  db = pParse->db;
   pLevel = &pWInfo->a[iLevel];
   pLoop = pLevel->pWLoop;
   pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
@@ -3551,7 +3553,7 @@ static Bitmask codeOneLoopStart(
     ** starting at regBase.
     */
     regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
-    zEndAff = sqlite3DbStrDup(pParse->db, zStartAff);
+    zEndAff = sqlite3DbStrDup(db, zStartAff);
     addrNxt = pLevel->addrNxt;
 
     /* If we are doing a reverse order scan on an ascending index, or
@@ -3636,8 +3638,8 @@ static Bitmask codeOneLoopStart(
       nConstraint++;
       testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
     }
-    sqlite3DbFree(pParse->db, zStartAff);
-    sqlite3DbFree(pParse->db, zEndAff);
+    sqlite3DbFree(db, zStartAff);
+    sqlite3DbFree(db, zEndAff);
 
     /* Top of the loop body */
     pLevel->p2 = sqlite3VdbeCurrentAddr(v);
@@ -3764,7 +3766,7 @@ static Bitmask codeOneLoopStart(
       int nNotReady;                 /* The number of notReady tables */
       struct SrcList_item *origSrc;     /* Original list of tables */
       nNotReady = pWInfo->nLevel - iLevel - 1;
-      pOrTab = sqlite3StackAllocRaw(pParse->db,
+      pOrTab = sqlite3StackAllocRaw(db,
                             sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
       if( pOrTab==0 ) return notReady;
       pOrTab->nAlloc = (u8)(nNotReady + 1);
@@ -3818,8 +3820,8 @@ static Bitmask codeOneLoopStart(
         if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
         if( pWC->a[iTerm].wtFlags & (TERM_ORINFO) ) continue;
         if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
-        pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
-        pAndExpr = sqlite3ExprAnd(pParse->db, pAndExpr, pExpr);
+        pExpr = sqlite3ExprDup(db, pExpr, 0);
+        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
       }
       if( pAndExpr ){
         pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
@@ -3839,7 +3841,7 @@ static Bitmask codeOneLoopStart(
         pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
                         WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY |
                         WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY, iCovCur);
-        assert( pSubWInfo || pParse->nErr || pParse->db->mallocFailed );
+        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
         if( pSubWInfo ){
           WhereLoop *pSubLoop;
           explainOneScan(
@@ -3894,13 +3896,13 @@ static Bitmask codeOneLoopStart(
     if( pCov ) pLevel->iIdxCur = iCovCur;
     if( pAndExpr ){
       pAndExpr->pLeft = 0;
-      sqlite3ExprDelete(pParse->db, pAndExpr);
+      sqlite3ExprDelete(db, pAndExpr);
     }
     sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
     sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
     sqlite3VdbeResolveLabel(v, iLoopBody);
 
-    if( pWInfo->nLevel>1 ) sqlite3StackFree(pParse->db, pOrTab);
+    if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
     if( !untestedTerms ) disableTerm(pLevel, pTerm);
   }else
 #endif /* SQLITE_OMIT_OR_OPTIMIZATION */
@@ -3955,9 +3957,8 @@ static Bitmask codeOneLoopStart(
   ** the implied "t1.a=123" constraint.
   */
   for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
-    Expr *pE;
+    Expr *pE, *pEAlt;
     WhereTerm *pAlt;
-    Expr sEq;
     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
     if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue;
     if( pTerm->leftCursor!=iCur ) continue;
@@ -3971,9 +3972,13 @@ static Bitmask codeOneLoopStart(
     testcase( pAlt->eOperator & WO_EQ );
     testcase( pAlt->eOperator & WO_IN );
     VdbeNoopComment((v, "begin transitive constraint"));
-    sEq = *pAlt->pExpr;
-    sEq.pLeft = pE->pLeft;
-    sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL);
+    pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
+    if( pEAlt ){
+      *pEAlt = *pAlt->pExpr;
+      pEAlt->pLeft = pE->pLeft;
+      sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
+      sqlite3StackFree(db, pEAlt);
+    }
   }
 
   /* For a LEFT OUTER JOIN, generate code that will record the fact that