From: Tom Lane Date: Fri, 3 Jun 2016 23:12:29 +0000 (-0400) Subject: Fix grammar's AND/OR flattening to work with operator_precedence_warning. X-Git-Tag: REL9_6_BETA2~112 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=05104f693646c0a4ae446e79cb89057497da17e4;p=postgresql 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: --- diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 20384db2fb..ad338d3ddb 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -14643,10 +14643,16 @@ 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) { @@ -14660,10 +14666,16 @@ 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) {