re PR c++/67354 (internal compiler error: in add_to_same_comdat_group, at symtab.c:421)

	PR c++/67354
	* cp-tree.h (defer_mangling_aliases): Declare.
	(generate_mangling_aliases): New prototype.
	* decl2.c (defer_mangling_aliases): New variable.
	(note_mangling_alias): Use !defer_mangling_aliases
	instead of at_eof.
	(generate_mangling_aliases): No longer static. Clear
	defer_mangling_aliases.
	* optimize.c (maybe_thunk_body): Defer emitting mangling aliases
	if !defer_mangling_aliases until the fns are put into the same
	comdat group.

	* g++.dg/abi/mangle67.C: New test.

From-SVN: r230646

6 files changed, 63 insertions, 2 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index cf436d7..0428c3c 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,17 @@
+2015-11-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/67354
+	* cp-tree.h (defer_mangling_aliases): Declare.
+	(generate_mangling_aliases): New prototype.
+	* decl2.c (defer_mangling_aliases): New variable.
+	(note_mangling_alias): Use !defer_mangling_aliases
+	instead of at_eof.
+	(generate_mangling_aliases): No longer static. Clear
+	defer_mangling_aliases.
+	* optimize.c (maybe_thunk_body): Defer emitting mangling aliases
+	if !defer_mangling_aliases until the fns are put into the same
+	comdat group.
+
 2015-11-19  David Malcolm  <dmalcolm@redhat.com>
 
 	* cp-tree.h (lookup_member_fuzzy): New decl.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 38bd7dd..1672291 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -4846,6 +4846,11 @@ extern GTY(()) vec<tree, va_gc> *local_classes;
 
 extern int at_eof;
 
+/* True if note_mangling_alias should enqueue mangling aliases for
+   later generation, rather than emitting them right away.  */
+
+extern bool defer_mangling_aliases;
+
 /* A list of namespace-scope objects which have constructors or
    destructors which reside in the global scope.  The decl is stored
    in the TREE_VALUE slot and the initializer is stored in the
@@ -5772,6 +5777,7 @@ extern tree cxx_maybe_build_cleanup		(tree, tsubst_flags_t);
 
 /* in decl2.c */
 extern void note_mangling_alias			(tree, tree);
+extern void generate_mangling_aliases		(void);
 extern bool check_java_method			(tree);
 extern tree build_memfn_type			(tree, tree, cp_cv_quals, cp_ref_qualifier);
 extern tree build_pointer_ptrmemfn_type	(tree);
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 47c9ec9..2cc51d6 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -102,6 +102,11 @@ static GTY(()) vec<tree, va_gc> *mangling_aliases;
 /* Nonzero if we're done parsing and into end-of-file activities.  */
 
 int at_eof;
+
+/* True if note_mangling_alias should enqueue mangling aliases for
+   later generation, rather than emitting them right away.  */
+
+bool defer_mangling_aliases = true;
 
 
 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
@@ -4389,7 +4394,7 @@ void
 note_mangling_alias (tree decl ATTRIBUTE_UNUSED, tree id2 ATTRIBUTE_UNUSED)
 {
 #ifdef ASM_OUTPUT_DEF
-  if (at_eof)
+  if (!defer_mangling_aliases)
     generate_mangling_alias (decl, id2);
   else
     {
@@ -4399,7 +4404,9 @@ note_mangling_alias (tree decl ATTRIBUTE_UNUSED, tree id2 ATTRIBUTE_UNUSED)
 #endif
 }
 
-static void
+/* Emit all mangling aliases that were deferred up to this point.  */
+
+void
 generate_mangling_aliases ()
 {
   while (!vec_safe_is_empty (mangling_aliases))
@@ -4408,6 +4415,7 @@ generate_mangling_aliases ()
       tree decl = mangling_aliases->pop();
       generate_mangling_alias (decl, id2);
     }
+  defer_mangling_aliases = false;
 }
 
 /* The entire file is now complete.  If requested, dump everything
diff --git a/gcc/cp/optimize.c b/gcc/cp/optimize.c
index c4e7020..a5f84a0 100644
--- a/gcc/cp/optimize.c
+++ b/gcc/cp/optimize.c
@@ -270,7 +270,11 @@ maybe_thunk_body (tree fn, bool force)
     }
   else if (HAVE_COMDAT_GROUP)
     {
+      /* At eof, defer creation of mangling aliases temporarily.  */
+      bool save_defer_mangling_aliases = defer_mangling_aliases;
+      defer_mangling_aliases = true;
       tree comdat_group = cdtor_comdat_group (fns[1], fns[0]);
+      defer_mangling_aliases = save_defer_mangling_aliases;
       cgraph_node::get_create (fns[0])->set_comdat_group (comdat_group);
       cgraph_node::get_create (fns[1])->add_to_same_comdat_group
 	(cgraph_node::get_create (fns[0]));
@@ -281,6 +285,9 @@ maybe_thunk_body (tree fn, bool force)
 	   virtual, it goes into the same comdat group as well.  */
 	cgraph_node::get_create (fns[2])->add_to_same_comdat_group
 	  (symtab_node::get (fns[0]));
+      /* Emit them now that the thunks are same comdat group aliases.  */
+      if (!save_defer_mangling_aliases)
+	generate_mangling_aliases ();
       TREE_PUBLIC (fn) = false;
       DECL_EXTERNAL (fn) = false;
       DECL_INTERFACE_KNOWN (fn) = true;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e1e88fa..75ea160 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-11-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/67354
+	* g++.dg/abi/mangle67.C: New test.
+
 2015-11-20  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	* gcc.target/s390/bswap-1.c: New test.
diff --git a/gcc/testsuite/g++.dg/abi/mangle67.C b/gcc/testsuite/g++.dg/abi/mangle67.C
new file mode 100644
index 0000000..69ca90b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/abi/mangle67.C
@@ -0,0 +1,21 @@
+// PR c++/67354
+// { dg-do compile { target c++11 } }
+// { dg-options "-fabi-version=5 -Os" }
+
+class A
+{
+};
+
+template <typename T>
+void
+foo ()
+{
+  T ();
+}
+
+struct B : virtual A
+{
+  template <typename...> B () {}
+};
+
+auto f = foo<B>;