[PATCH] Fix ICE with mangling aliases (PR c++/67354, take 2)

[Jakub Jelinek <jakub at redhat dot com>]

On Wed, Nov 18, 2015 at 04:22:21PM -0500, Jason Merrill wrote:
> On 11/18/2015 03:52 AM, Jakub Jelinek wrote:
> >If changing at_eof for this is too big hack, perhaps we could have a
> >different bool just to affect the mangling aliases (and set it to true
> >in generate_mangling_aliases or so).
> 
> Let's do that.

Here it is.  Bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk/5.3?

2015-11-19  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.
	(c_parse_final_cleanups): 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.

--- gcc/cp/cp-tree.h.jj	2015-11-18 11:19:20.956770209 +0100
+++ gcc/cp/cp-tree.h	2015-11-19 09:58:00.355009161 +0100
@@ -4842,6 +4842,11 @@ extern GTY(()) vec<tree, va_gc> *local_c
 
 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
@@ -5768,6 +5773,7 @@ extern tree cxx_maybe_build_cleanup		(tr
 
 /* 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);
--- gcc/cp/decl2.c.jj	2015-11-18 11:19:12.866884363 +0100
+++ gcc/cp/decl2.c	2015-11-19 10:12:24.423695746 +0100
@@ -102,6 +102,11 @@ static GTY(()) vec<tree, va_gc> *manglin
 /* 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
 #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))
@@ -4502,6 +4509,7 @@ c_parse_final_cleanups (void)
 
   locus_at_end_of_parsing = input_location;
   at_eof = 1;
+  defer_mangling_aliases = false;
 
   /* Bad parse errors.  Just forget about it.  */
   if (! global_bindings_p () || current_class_type
--- gcc/cp/optimize.c.jj	2015-11-18 11:19:12.935883389 +0100
+++ gcc/cp/optimize.c	2015-11-19 10:12:24.423695746 +0100
@@ -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;
--- gcc/testsuite/g++.dg/abi/mangle67.C.jj	2015-11-19 09:54:51.644701162 +0100
+++ gcc/testsuite/g++.dg/abi/mangle67.C	2015-11-19 09:54:51.644701162 +0100
@@ -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>;


	Jakub