Bug 54552 is a C front-end regression involving ICEs when an
expression involving C_MAYBE_CONST_EXPR, such as a compound literal of
variably modified type, is cast to a variably modified type. This
patch fixes it by doing the appropriate folding before creating the
outer C_MAYBE_CONST_EXPR.
Bootstrapped with no regressions on x86_64-unknown-linux-gnu. Applied
to mainline. Will apply to 4.7 (when not frozen) and 4.6 branches
subject to testing there.
c:
2012-09-14 Joseph Myers <jos...@codesourcery.com>
PR c/54552
* c-typeck.c (c_cast_expr): When casting to a type requiring
C_MAYBE_CONST_EXPR to be created, pass the inner expression to
c_fully_fold first.
testsuite:
2012-09-14 Joseph Myers <jos...@codesourcery.com>
PR c/54552
* gcc.c-torture/compile/pr54552-1.c: New test.
Index: c/c-typeck.c
===================================================================
--- c/c-typeck.c (revision 191305)
+++ c/c-typeck.c (working copy)
@@ -4779,8 +4779,11 @@ c_cast_expr (location_t loc, struct c_type_name *t
ret = build_c_cast (loc, type, expr);
if (type_expr)
{
+ bool inner_expr_const = true;
+ ret = c_fully_fold (ret, require_constant_value, &inner_expr_const);
ret = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (ret), type_expr, ret);
- C_MAYBE_CONST_EXPR_NON_CONST (ret) = !type_expr_const;
+ C_MAYBE_CONST_EXPR_NON_CONST (ret) = !(type_expr_const
+ && inner_expr_const);
SET_EXPR_LOCATION (ret, loc);
}
Index: testsuite/gcc.c-torture/compile/pr54552-1.c
===================================================================
--- testsuite/gcc.c-torture/compile/pr54552-1.c (revision 0)
+++ testsuite/gcc.c-torture/compile/pr54552-1.c (revision 0)
@@ -0,0 +1,8 @@
+void
+f (void)
+{
+ unsigned n = 10;
+
+ typedef double T[n];
+ (double (*)[n])((unsigned char (*)[sizeof (T)]){ 0 });
+}
--
Joseph S. Myers
jos...@codesourcery.com
