From c82037e372394ee046e278887c8f938591ca7406 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 3 Jun 2016 19:12:30 -0400 Subject: [PATCH] Fix grammar's AND/OR flattening to work with operator_precedence_warning. It'd be good for "(x AND y) AND z" to produce a three-child AND node whether or not operator_precedence_warning is on, but that failed to happen when it's on because makeAndExpr() didn't look through the added AEXPR_PAREN node. This has no effect on generated plans because prepqual.c would flatten the AND nest anyway; but it does affect the number of parens printed in ruleutils.c, for example. I'd already fixed some similar hazards in parse_expr.c in commit abb164655, but didn't think to search gram.y for problems of this ilk. Per gripe from Jean-Pierre Pelletier. Report: --- src/backend/parser/gram.y | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index c46914d87b..c554e634fb 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -14512,10 +14512,16 @@ doNegateFloat(Value *v) static Node * makeAndExpr(Node *lexpr, Node *rexpr, int location) { + Node *lexp = lexpr; + + /* Look through AEXPR_PAREN nodes so they don't affect flattening */ + while (IsA(lexp, A_Expr) && + ((A_Expr *) lexp)->kind == AEXPR_PAREN) + lexp = ((A_Expr *) lexp)->lexpr; /* Flatten "a AND b AND c ..." to a single BoolExpr on sight */ - if (IsA(lexpr, BoolExpr)) + if (IsA(lexp, BoolExpr)) { - BoolExpr *blexpr = (BoolExpr *) lexpr; + BoolExpr *blexpr = (BoolExpr *) lexp; if (blexpr->boolop == AND_EXPR) { @@ -14529,10 +14535,16 @@ makeAndExpr(Node *lexpr, Node *rexpr, int location) static Node * makeOrExpr(Node *lexpr, Node *rexpr, int location) { + Node *lexp = lexpr; + + /* Look through AEXPR_PAREN nodes so they don't affect flattening */ + while (IsA(lexp, A_Expr) && + ((A_Expr *) lexp)->kind == AEXPR_PAREN) + lexp = ((A_Expr *) lexp)->lexpr; /* Flatten "a OR b OR c ..." to a single BoolExpr on sight */ - if (IsA(lexpr, BoolExpr)) + if (IsA(lexp, BoolExpr)) { - BoolExpr *blexpr = (BoolExpr *) lexpr; + BoolExpr *blexpr = (BoolExpr *) lexp; if (blexpr->boolop == OR_EXPR) {