PR c++/70627

	* decl.c (start_enum): Don't change an existing ENUM_UNDERLYING_TYPE.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@234956 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 38 insertions, 1 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 8f1ae231521..837a58c338f 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2016-04-13  Jason Merrill  <jason@redhat.com>
+
+	PR c++/70627
+	* decl.c (start_enum): Don't change an existing ENUM_UNDERLYING_TYPE.
+
 2016-04-13  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/70635
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 2ac5c4b1fbf..380bc79ea53 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -13253,7 +13253,10 @@ start_enum (tree name, tree enumtype, tree underlying_type,
 
   if (underlying_type)
     {
-      if (CP_INTEGRAL_TYPE_P (underlying_type))
+      if (ENUM_UNDERLYING_TYPE (enumtype))
+	/* We already checked that it matches, don't change it to a different
+	   typedef variant.  */;
+      else if (CP_INTEGRAL_TYPE_P (underlying_type))
         {
 	  copy_type_enum (enumtype, underlying_type);
           ENUM_UNDERLYING_TYPE (enumtype) = underlying_type;
diff --git a/gcc/testsuite/g++.dg/cpp0x/enum_base3.C b/gcc/testsuite/g++.dg/cpp0x/enum_base3.C
new file mode 100644
index 00000000000..3cb2d6d8186
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/enum_base3.C
@@ -0,0 +1,29 @@
+// PR c++/70627
+// { dg-do compile { target c++11 } }
+
+struct D;
+struct A
+{
+  D *operator->();
+};
+struct B
+{
+  template <typename... T> void foo (T &&...) {}
+};
+typedef unsigned char G;
+enum class H : G;
+struct C
+{
+};
+struct D : C
+{
+  B foo () const { B a; a.foo (d); }
+  H d;
+};
+struct F : C
+{
+  void foo ();
+  A f;
+};
+enum class H : unsigned char;
+void F::foo () { B b = f->foo (); }