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Take care that the code is not generated for the same Select object more

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than once, as transformations that apply during the first pass might
cause problems for the second pass.
dbsqlfuzz 836b625cd8a41809ef80fc7ebaa6554357bcb463.

FossilOrigin-Name: f30fb19ff763a7cbe768ea49954704e14d6400f69bb4257c9c890e1564e14835
This commit is contained in:
drh
2021-05-26 18:46:51 +00:00
parent 151446e793
commit 14c4d42874
5 changed files with 43 additions and 51 deletions
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54
src/expr.c
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@@ -2985,19 +2985,23 @@ void sqlite3CodeRhsOfIN(
/* If the LHS and RHS of the IN operator do not match, that
** error will have been caught long before we reach this point. */
if( ALWAYS(pEList->nExpr==nVal) ){
Select *pCopy;
SelectDest dest;
int i;
int rc;
sqlite3SelectDestInit(&dest, SRT_Set, iTab);
dest.zAffSdst = exprINAffinity(pParse, pExpr);
pSelect->iLimit = 0;
testcase( pSelect->selFlags & SF_Distinct );
testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
if( sqlite3Select(pParse, pSelect, &dest) ){
sqlite3DbFree(pParse->db, dest.zAffSdst);
pCopy = sqlite3SelectDup(pParse->db, pSelect, 0);
rc = pParse->db->mallocFailed ? 1 :sqlite3Select(pParse, pCopy, &dest);
sqlite3SelectDelete(pParse->db, pCopy);
sqlite3DbFree(pParse->db, dest.zAffSdst);
if( rc ){
sqlite3KeyInfoUnref(pKeyInfo);
return;
}
sqlite3DbFree(pParse->db, dest.zAffSdst);
}
assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
assert( pEList!=0 );
assert( pEList->nExpr>0 );
@@ -3103,6 +3107,23 @@ int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
assert( ExprHasProperty(pExpr, EP_xIsSelect) );
pSel = pExpr->x.pSelect;
/* If this routine has already been coded, then invoke it as a
** subroutine. */
if( ExprHasProperty(pExpr, EP_Subrtn) ){
ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
pExpr->y.sub.iAddr);
return pExpr->iTable;
}
/* Begin coding the subroutine */
ExprSetProperty(pExpr, EP_Subrtn);
pExpr->y.sub.regReturn = ++pParse->nMem;
pExpr->y.sub.iAddr =
sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
VdbeComment((v, "return address"));
/* The evaluation of the EXISTS/SELECT must be repeated every time it
** is encountered if any of the following is true:
**
@@ -3114,22 +3135,6 @@ int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
** save the results, and reuse the same result on subsequent invocations.
*/
if( !ExprHasProperty(pExpr, EP_VarSelect) ){
/* If this routine has already been coded, then invoke it as a
** subroutine. */
if( ExprHasProperty(pExpr, EP_Subrtn) ){
ExplainQueryPlan((pParse, 0, "REUSE SUBQUERY %d", pSel->selId));
sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
pExpr->y.sub.iAddr);
return pExpr->iTable;
}
/* Begin coding the subroutine */
ExprSetProperty(pExpr, EP_Subrtn);
pExpr->y.sub.regReturn = ++pParse->nMem;
pExpr->y.sub.iAddr =
sqlite3VdbeAddOp2(v, OP_Integer, 0, pExpr->y.sub.regReturn) + 1;
VdbeComment((v, "return address"));
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
@@ -3188,13 +3193,12 @@ int sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
ExprSetVVAProperty(pExpr, EP_NoReduce);
if( addrOnce ){
sqlite3VdbeJumpHere(v, addrOnce);
/* Subroutine return */
sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
sqlite3ClearTempRegCache(pParse);
}
/* Subroutine return */
sqlite3VdbeAddOp1(v, OP_Return, pExpr->y.sub.regReturn);
sqlite3VdbeChangeP1(v, pExpr->y.sub.iAddr-1, sqlite3VdbeCurrentAddr(v)-1);
sqlite3ClearTempRegCache(pParse);
return rReg;
}
#endif /* SQLITE_OMIT_SUBQUERY */