compat-libgfortran-48/gcc48-pr80129.patch

46 lines
1.3 KiB
Diff
Raw Normal View History

2021-01-21 00:56:15 +00:00
2017-05-30 Jakub Jelinek <jakub@redhat.com>
Backported from mainline
2017-03-22 Jakub Jelinek <jakub@redhat.com>
PR c++/80129
* gimplify.c (gimplify_modify_expr_rhs) <case COND_EXPR>: Clear
TREE_READONLY on result if writing it more than once.
* g++.dg/torture/pr80129.C: New test.
--- gcc/gimplify.c
+++ gcc/gimplify.c
@@ -4293,6 +4293,14 @@ gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p,
if (ret != GS_ERROR)
ret = GS_OK;
+ /* If we are going to write RESULT more than once, clear
+ TREE_READONLY flag, otherwise we might incorrectly promote
+ the variable to static const and initialize it at compile
+ time in one of the branches. */
+ if (TREE_CODE (result) == VAR_DECL
+ && TREE_TYPE (TREE_OPERAND (cond, 1)) != void_type_node
+ && TREE_TYPE (TREE_OPERAND (cond, 2)) != void_type_node)
+ TREE_READONLY (result) = 0;
if (TREE_TYPE (TREE_OPERAND (cond, 1)) != void_type_node)
TREE_OPERAND (cond, 1)
= build2 (code, void_type_node, result,
--- /dev/null
+++ gcc/testsuite/g++.dg/torture/pr80129.C
@@ -0,0 +1,14 @@
+// PR c++/80129
+// { dg-do run }
+// { dg-options "-std=c++11" }
+
+struct A { bool a; int b; };
+
+int
+main ()
+{
+ bool c = false;
+ const A x = c ? A {true, 1} : A {false, 0};
+ if (x.a)
+ __builtin_abort ();
+}