re PR c++/52043 ([C++0x] ICE: SIGSEGV in tsubst_copy (pt.c:12081) with -Wreturn-type)

	PR c++/52043
	* cp-tree.h (PACK_EXPANSION_LOCAL_P): New.
	* pt.c (make_pack_expansion, tsubst_initializer_list): Set it.
	(tsubst_pack_expansion): Check it.

From-SVN: r183768

gcc/cp/ChangeLog

+2012-01-31  Jason Merrill  <jason@redhat.com>
+
+	PR c++/52043
+	* cp-tree.h (PACK_EXPANSION_LOCAL_P): New.
+	* pt.c (make_pack_expansion, tsubst_initializer_list): Set it.
+	(tsubst_pack_expansion): Check it.
+
 2012-01-29  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/51327

gcc/cp/cp-tree.h

@@ -76,6 +76,7 @@ c-common.h, not after.
       TRANSACTION_EXPR_IS_STMT (in TRANSACTION_EXPR)
       CONVERT_EXPR_VBASE_PATH (in CONVERT_EXPR)
       OVL_ARG_DEPENDENT (in OVERLOAD)
+      PACK_EXPANSION_LOCAL_P (in *_PACK_EXPANSION)
    1: IDENTIFIER_VIRTUAL_P (in IDENTIFIER_NODE)
       TI_PENDING_TEMPLATE_FLAG.
       TEMPLATE_PARMS_FOR_INLINE.
@@ -2839,6 +2840,9 @@ extern void decl_shadowed_for_var_insert (tree, tree);
     ? &TYPE_MAXVAL (NODE)			\
     : &TREE_OPERAND ((NODE), 2))
 
+/* True iff this pack expansion is within a function context.  */
+#define PACK_EXPANSION_LOCAL_P(NODE) TREE_LANG_FLAG_0 (NODE)
+
 /* Determine if this is an argument pack.  */
 #define ARGUMENT_PACK_P(NODE)                          \
   (TREE_CODE (NODE) == TYPE_ARGUMENT_PACK              \

gcc/cp/pt.c

@@ -3238,6 +3238,8 @@ make_pack_expansion (tree arg)
     }
   PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
 
+  PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
+
   return result;
 }
 
@@ -9340,7 +9342,7 @@ tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
        }
       if (TREE_CODE (parm_pack) == PARM_DECL)
 	{
-	  if (at_function_scope_p ())
+	  if (PACK_EXPANSION_LOCAL_P (t))
 	    arg_pack = retrieve_local_specialization (parm_pack);
 	  else
 	    {
@@ -18905,6 +18907,7 @@ tsubst_initializer_list (tree t, tree argvec)
           /* Build a dummy EXPR_PACK_EXPANSION that will be used to
              expand each argument in the TREE_VALUE of t.  */
           expr = make_node (EXPR_PACK_EXPANSION);
+	  PACK_EXPANSION_LOCAL_P (expr) = true;
           PACK_EXPANSION_PARAMETER_PACKS (expr) =
             PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
 

gcc/testsuite/ChangeLog

+2012-01-31  Jason Merrill  <jason@redhat.com>
+
+	PR c++/52043
+	* g++.dg/cpp0x/variadic122.C: New.
+
 2012-01-31  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/52012

gcc/testsuite/g++.dg/cpp0x/variadic122.C

+// PR c++/52043
+// { dg-options "-std=c++11 -Wreturn-type" }
+
+template < class T > struct Container
+{
+  T f ();
+};
+
+template < class T >
+T deref (T)
+{}				// { dg-warning "no return" }
+
+template < class T, class ... Args >
+auto deref (T u, int, Args ... args)->decltype (deref (u.f (), args ...))
+{}				// { dg-warning "no return" }
+
+void
+foo ()
+{
+  Container < Container < int > > v;
+  deref (v, 2);
+}