On 05/22/12 15:12, Richard Guenther wrote:
But I wonder why CONSTRUCTORs do not inherit TREE_SIDE_EFFECTS
properly ...
the attached patch fixes the ICE and causes no regressions on i686-pc-linux-gnu.
ok?
nathan
2012-05-23 Nathan Sidwell <nat...@acm.org>
* tree.c (build_constructor): Propagate TREE_SIDE_EFFECTS.
* gcc.dg/stmt-expr-4.c: New.
Index: tree.c
===================================================================
--- tree.c (revision 187628)
+++ tree.c (working copy)
@@ -1416,17 +1416,24 @@ build_constructor (tree type, VEC(constr
unsigned int i;
constructor_elt *elt;
bool constant_p = true;
+ bool side_effects_p = false;
TREE_TYPE (c) = type;
CONSTRUCTOR_ELTS (c) = vals;
FOR_EACH_VEC_ELT (constructor_elt, vals, i, elt)
- if (!TREE_CONSTANT (elt->value))
- {
+ {
+ /* Mostly ctors will have elts that don't have side-effects, so
+ the usual case is to scan all the elements. Hence a single
+ loop for both const and side effects, rather than one loop
+ each (with early outs). */
+ if (!TREE_CONSTANT (elt->value))
constant_p = false;
- break;
- }
+ if (TREE_SIDE_EFFECTS (elt->value))
+ side_effects_p = true;
+ }
+ TREE_SIDE_EFFECTS (c) = side_effects_p;
TREE_CONSTANT (c) = constant_p;
return c;
Index: testsuite/gcc.dg/stmt-expr-4.c
===================================================================
--- testsuite/gcc.dg/stmt-expr-4.c (revision 0)
+++ testsuite/gcc.dg/stmt-expr-4.c (revision 0)
@@ -0,0 +1,22 @@
+
+/* { dg-options "-O2 -std=gnu99" } */
+/* Internal compiler error in iterative_hash_expr */
+
+struct tree_string
+{
+ char str[1];
+};
+
+union tree_node
+{
+ struct tree_string string;
+};
+
+char *Foo (union tree_node * num_string)
+{
+ char *str = ((union {const char * _q; char * _nq;})
+ ((const char *)(({ __typeof (num_string) const __t
+ = num_string; __t; })
+ ->string.str)))._nq;
+ return str;
+}
