From 9f7fb685d9173285be6507805ced732d360c09be Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Wed, 29 Apr 2015 16:51:05 -0400
Subject: [PATCH] re PR c++/50800 (Internal compiler error in
 finish_member_declarations, possibly related to may_alias attribute)

	PR c++/50800
	* tree.c (apply_identity_attributes): Fix handling of classes.

From-SVN: r222591
---
 gcc/cp/ChangeLog                      |  5 +++++
 gcc/cp/tree.c                         |  7 +++++++
 gcc/testsuite/g++.dg/cpp0x/alignas3.C | 20 ++++++++++++++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/alignas3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 9442faa9c40..d78b22f1955 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2015-04-29  Jason Merrill  <jason@redhat.com>
+
+	PR c++/50800
+	* tree.c (apply_identity_attributes): Fix handling of classes.
+
 2015-04-29  Thomas Schwinge  <thomas@codesourcery.com>
 
 	* parser.c (cp_parser_oacc_enter_exit_data): Use
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index d00f0d7eab1..ec9be8c2bc4 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -1187,6 +1187,13 @@ apply_identity_attributes (tree result, tree attribs, bool *remove_attributes)
   tree new_attribs = NULL_TREE;
   tree *p = &new_attribs;
 
+  if (OVERLOAD_TYPE_P (result))
+    {
+      /* On classes and enums all attributes are ingrained.  */
+      gcc_assert (attribs == TYPE_ATTRIBUTES (result));
+      return result;
+    }
+
   for (tree a = attribs; a; a = TREE_CHAIN (a))
     {
       const attribute_spec *as
diff --git a/gcc/testsuite/g++.dg/cpp0x/alignas3.C b/gcc/testsuite/g++.dg/cpp0x/alignas3.C
new file mode 100644
index 00000000000..aa62e5afb2d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alignas3.C
@@ -0,0 +1,20 @@
+// PR c++/50800
+// { dg-do compile { target c++11 } }
+
+template <typename> struct A;
+template <typename _Up> struct A<_Up *> { typedef _Up type; };
+template <typename T> struct B { typedef typename A<T>::type type; };
+template <typename> struct C;
+template <typename From> struct C<const From> {
+  typedef typename B<From>::type SimpleType;
+};
+template <class> struct D { typedef int ret_type; };
+template <class From> struct F {
+  typedef typename D<typename C<From>::SimpleType>::ret_type ret_type;
+};
+template <class, class Y> typename F<Y>::ret_type cast(Y &);
+class CompoundStmt;
+class alignas(8) Stmt {
+  Stmt *Children[1];
+  CompoundStmt *getBlock() const { cast<CompoundStmt>(Children[0]); }
+};
-- 
2.30.2