re PR c++/60033 ([c++1y] ICE in retrieve_specialization while compiling recursive generic lambda)

Fix PR c++/60033

	PR c++/60033
	* pt.c (tsubst_copy): When retrieving a capture pack from a generic
	lambda, remove the lambda's own template argument list prior to fetching
	the specialization.

	PR c++/60033
	* g++.dg/cpp1y/pr60033.C: New testcase.

From-SVN: r208427

gcc/cp/ChangeLog

 2014-03-08  Adam Butcher  <adam@jessamine.co.uk>
 
+	PR c++/60033
+	* pt.c (tsubst_copy): When retrieving a capture pack from a generic
+	lambda, remove the lambda's own template argument list prior to fetching
+	the specialization.
+
 	PR c++/60393
 	* parser.c (cp_parser_parameter_declaration_clause): Move generic
 	function template unwinding on error into a more general location, ...

gcc/cp/pt.c

@@ -12565,14 +12565,22 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	{
 	  /* Check for a local specialization set up by
 	     tsubst_pack_expansion.  */
-	  tree r = retrieve_local_specialization (t);
-	  if (r)
+	  if (tree r = retrieve_local_specialization (t))
 	    {
 	      if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
 		r = ARGUMENT_PACK_SELECT_ARG (r);
 	      return r;
 	    }
 
+	  /* When retrieving a capture pack from a generic lambda, remove the
+	     lambda call op's own template argument list from ARGS.  Only the
+	     template arguments active for the closure type should be used to
+	     retrieve the pack specialization.  */
+	  if (LAMBDA_FUNCTION_P (current_function_decl)
+	      && (template_class_depth (DECL_CONTEXT (t))
+		  != TMPL_ARGS_DEPTH (args)))
+	    args = strip_innermost_template_args (args, 1);
+
 	  /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
 	     tsubst_decl put in the hash table.  */
 	  return retrieve_specialization (t, args, 0);

gcc/testsuite/ChangeLog

 2014-03-08  Adam Butcher  <adam@jessamine.co.uk>
 
+	PR c++/60033
+	* g++.dg/cpp1y/pr60033.C: New testcase.
+
 	PR c++/60393
 	* g++.dg/cpp1y/pr60393.C: New testcase.
 

gcc/testsuite/g++.dg/cpp1y/pr60033.C

+// PR c++/60033
+// { dg-options -std=c++1y }
+
+template <typename... T>
+auto f(T&&... ts)
+{
+   return sizeof...(ts);
+}
+
+template <typename... T>
+auto g(T&&... ts) {
+  return [&] (auto v) {
+    return f(ts...);
+  };
+}
+
+int main()
+{
+   return g(1,2,3,4)(5) == 4 ? 0 : 1;
+}