re PR c++/51827 (Error: 'FOO' conflicts with a previous declaration, with PCH/LTO/C++11)

	PR c++/51827
	* mangle.c (mangle_decl): Don't mangle uninstantiated templates.

From-SVN: r183221

gcc/cp/ChangeLog

 2012-01-16  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51827
+	* mangle.c (mangle_decl): Don't mangle uninstantiated templates.
+
 	PR c++/51868
 	* typeck.c (build_static_cast_1): Handle bit-fields properly.
 

gcc/cp/mangle.c

@@ -3330,7 +3330,21 @@ get_mangled_id (tree decl)
 void
 mangle_decl (const tree decl)
 {
-  tree id = get_mangled_id (decl);
+  tree id;
+  bool dep;
+
+  /* Don't bother mangling uninstantiated templates.  */
+  ++processing_template_decl;
+  if (TREE_CODE (decl) == TYPE_DECL)
+    dep = dependent_type_p (TREE_TYPE (decl));
+  else
+    dep = (DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl)
+	   && any_dependent_template_arguments_p (DECL_TI_ARGS (decl)));
+  --processing_template_decl;
+  if (dep)
+    return;
+
+  id = get_mangled_id (decl);
   SET_DECL_ASSEMBLER_NAME (decl, id);
 
   if (G.need_abi_warning

gcc/testsuite/ChangeLog

+2012-01-16  Jason Merrill  <jason@redhat.com>
+
+	PR c++/51827
+	* g++.dg/pch/mangle1.{C,Hs}: New.
+
 2012-01-16  Mikael Morin  <mikael@gcc.gnu.org>
 	    Tobias Burnus  <burnus@net-b.de>
 

gcc/testsuite/g++.dg/pch/mangle1.C

+// { dg-options -std=c++11 }
+
+#include "mangle1.Hs"

gcc/testsuite/g++.dg/pch/mangle1.Hs

+// PR c++/51827
+// { dg-options "-flto -std=c++0x" }
+
+template<typename X> struct S { };
+template<typename Y> struct T {
+  template <typename ... A> T(S <A ...>);
+};
+inline void f(T<int>) { }