diff mbox series

[C++] Propagate TYPE_PACKED to template variants (PR c++/88181)

Message ID 20181126205459.GK12380@tucnak
State New
Headers show
Series [C++] Propagate TYPE_PACKED to template variants (PR c++/88181) | expand

Commit Message

Jakub Jelinek Nov. 26, 2018, 8:54 p.m. UTC 
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  <jakub@redhat.com>

	PR c++/88181
	* class.c (fixup_attribute_variants): Also propagate TYPE_PACKED
	to variants.

	* g++.dg/debug/pr88181.C: New test.


	Jakub

Comments

Jason Merrill Nov. 27, 2018, 9:02 p.m. UTC | #1 
On 11/26/18 3:54 PM, Jakub Jelinek wrote:
> 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  <jakub@redhat.com>
> 
> 	PR c++/88181
> 	* class.c (fixup_attribute_variants): Also propagate TYPE_PACKED
> 	to variants.

OK.

Jason
diff mbox series

Patch

--- 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);
+}