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[C PATCH] Don't leak C_MAYBE_CONST_EXPRs into GIMPLE (PR c/59891)
- From: Marek Polacek <polacek at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Jakub Jelinek <jakub at redhat dot com>, "Joseph S. Myers" <joseph at codesourcery dot com>
- Date: Wed, 22 Jan 2014 22:04:11 +0100
- Subject: [C PATCH] Don't leak C_MAYBE_CONST_EXPRs into GIMPLE (PR c/59891)
- Authentication-results: sourceware.org; auth=none
As mentioned in the PR, C FE leaked C_MAYBE_CONST_EXPR into GIMPLE.
This happened because remove_c_maybe_const_expr doesn't look for
nested C_MAYBE_CONST_EXPRs. But c_fully_fold will fold these away,
so use that.
Regtested/bootstrapped on x86_64-linux, ok for trunk and 4.8?
Alternatively, we could in if (int_operands) look at op1/op2, and
call c_fully_fold only if C_MAYBE_CONST_EXPR isn't the top level
expression.
2014-01-22 Marek Polacek <polacek@redhat.com>
PR c/59891
c/
* c-typeck.c (build_conditional_expr): Call c_fully_fold instead
of remove_c_maybe_const_expr on op1 and op2.
testsuite/
* gcc.dg/torture/pr59891.c: New test.
--- gcc/c/c-typeck.c.mp3 2014-01-22 18:47:36.812358319 +0100
+++ gcc/c/c-typeck.c 2014-01-22 18:45:10.298692933 +0100
@@ -4708,8 +4708,10 @@ build_conditional_expr (location_t colon
{
if (int_operands)
{
- op1 = remove_c_maybe_const_expr (op1);
- op2 = remove_c_maybe_const_expr (op2);
+ /* Use c_fully_fold here, since C_MAYBE_CONST_EXPR might be
+ nested inside of the expression. */
+ op1 = c_fully_fold (op1, false, NULL);
+ op2 = c_fully_fold (op2, false, NULL);
}
ret = build3 (COND_EXPR, result_type, ifexp, op1, op2);
if (int_operands)
--- gcc/testsuite/gcc.dg/torture/pr59891.c.mp3 2014-01-22 19:16:34.000000000 +0100
+++ gcc/testsuite/gcc.dg/torture/pr59891.c 2014-01-22 19:19:23.996129684 +0100
@@ -0,0 +1,9 @@
+/* PR c/59891 */
+
+unsigned int a;
+
+int
+main ()
+{
+ return (0 ? a : 0) ? : 0 % 0; /* { dg-warning "division by zero" } */
+}
Marek