Hello,
this issue fixes a type-overflow issue caused by trying to cast a UHWI
via tree_to_shwi.
As soon as value gets larger then SHWI_MAX, we get an error for it.
So we need to cast it
via tree_to_uhwi, and then casting it to the signed variant.
ChangeLog
2014-11-20 Kai Tietz <kti...@redhat.com>
PR c++/63904
* constexpr.c (cxx_eval_vec_init_1): Avoid
type-overflow issue.
2014-11-20 Kai Tietz <kti...@redhat.com>
PR c++/63904
* g++.dg/cpp0x/pr63904.C: New.
Regression tested for x86_64-unknown-linux-gnu. Ok for apply?
Regards,
Kai
Index: gcc/gcc/cp/constexpr.c
===================================================================
--- gcc.orig/gcc/cp/constexpr.c
+++ gcc/gcc/cp/constexpr.c
@@ -2006,12 +2050,12 @@ cxx_eval_vec_init_1 (const constexpr_ctx
bool *non_constant_p, bool *overflow_p)
{
tree elttype = TREE_TYPE (atype);
- int max = tree_to_shwi (array_type_nelts (atype));
+ HOST_WIDE_INT max = (HOST_WIDE_INT) tree_to_uhwi (array_type_nelts (atype));
verify_ctor_sanity (ctx, atype);
vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor);
vec_alloc (*p, max + 1);
bool pre_init = false;
- int i;
+ HOST_WIDE_INT i;
/* For the default constructor, build up a call to the default
constructor of the element type. We only need to handle class types
Index: gcc/gcc/testsuite/g++.dg/cpp0x/pr63904.C
===================================================================
--- /dev/null
+++ gcc/gcc/testsuite/g++.dg/cpp0x/pr63904.C
@@ -0,0 +1,13 @@
+// { dg-do compile { target c++11 } }
+
+template<int N>
+struct foo {
+ constexpr foo() : a() {}
+ int a[N];
+};
+
+int main() {
+ foo< (foo<1>{}).a[0] > f;
+ return 0;
+}
+
