Hi!
On the following patch -fpack-struct forces TYPE_PACKED on all the classes
and their variants, but we then create a variant of a class instantiation
(const) which doesn't have the TYPE_PACKED set and later finalize the
template main variant, but don't propagate that to the already created
variants.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
ok for trunk?
2018-11-26 Jakub Jelinek <ja...@redhat.com>
PR c++/88181
* class.c (fixup_attribute_variants): Also propagate TYPE_PACKED
to variants.
* g++.dg/debug/pr88181.C: New test.
--- gcc/cp/class.c.jj 2018-11-01 13:30:55.805803718 +0100
+++ gcc/cp/class.c 2018-11-26 15:07:59.555553144 +0100
@@ -1951,6 +1951,7 @@ fixup_attribute_variants (tree t)
unsigned align = TYPE_ALIGN (t);
bool user_align = TYPE_USER_ALIGN (t);
bool may_alias = lookup_attribute ("may_alias", attrs);
+ bool packed = TYPE_PACKED (t);
if (may_alias)
fixup_may_alias (t);
@@ -1968,6 +1969,7 @@ fixup_attribute_variants (tree t)
else
TYPE_USER_ALIGN (variants) = user_align;
SET_TYPE_ALIGN (variants, valign);
+ TYPE_PACKED (variants) = packed;
if (may_alias)
fixup_may_alias (variants);
}
--- gcc/testsuite/g++.dg/debug/pr88181.C.jj 2018-11-26 15:17:56.272765972
+0100
+++ gcc/testsuite/g++.dg/debug/pr88181.C 2018-11-26 15:17:44.745955023
+0100
@@ -0,0 +1,29 @@
+// PR c++/88181
+// { dg-do compile }
+// { dg-options "-fpack-struct -g -std=c++11" }
+
+template <typename T> struct A { typedef T B; };
+template <typename...> class C;
+template <typename e> struct D { constexpr D (e) {} };
+template <int, typename...> struct E;
+template <int N, typename T, typename... U>
+struct E<N, T, U...> : E<1, U...>, D<T> {
+ constexpr E (T x, U... y) : E<1, U...>(y...), D<T>(x) {}
+};
+template <int N, typename T> struct E<N, T> : D<T> {
+ constexpr E (T x) : D<T>(x) {}
+};
+template <typename T, typename U> struct C<T, U> : E<0, T, U> {
+ constexpr C (T x, U y) : E<0, T, U>(x, y) {}
+ void operator= (typename A<const C>::B);
+};
+struct F {};
+struct G {};
+
+int
+main ()
+{
+ F f;
+ G g;
+ constexpr C<F, G> c(f, g);
+}
Jakub
