Revert fix for PR c++/30044

gcc/cp/ChangeLog:

	Revert:
	2015-06-23  Patrick Palka  <ppalka@gcc.gnu.org>

	PR c++/30044
	* parser.c (cp_parser_template_parameter_list): Update
	current_template_parms right after processing a paramater.
	* pt.c (template_parms_to_args): Remove obsolete hack for
	giving template template arguments the proper level.
	(check_default_tmpl_args): Account for tested template
	parameter_lists.
	(splite_late_return_type): Remove obsolete hack for giving
	template template arguments the proper level.

gcc/testsuite/ChangeLog:

	Revert:
	2015-06-23  Patrick Palka  <ppalka@gcc.gnu.org>

	PR c++/30044
	* g++.dg/cpp0x/auto45.C: New test.
	* g++.dg/template/pr30044.C: New test.
	* g++.dg/template/crash83.C: Accept any error string.
	* g++.dg/cpp0x/variadic18.C: Adjust to not shadow template
	parameters.
	* g++.dg/cpp0x/variadic18.C: Likewise
	* g++.dg/template/canon-type-13.C: Likewise.
	* g++.old-deja/g++.pt/ttp42.C: Likewise.

From-SVN: r224896

3 files changed, 39 insertions, 34 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 03f0989..4b27519 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,18 @@
+2015-06-24  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	Revert:
+	2015-06-23  Patrick Palka  <ppalka@gcc.gnu.org>
+
+	PR c++/30044
+	* parser.c (cp_parser_template_parameter_list): Update
+	current_template_parms right after processing a paramater.
+	* pt.c (template_parms_to_args): Remove obsolete hack for
+	giving template template arguments the proper level.
+	(check_default_tmpl_args): Account for tested template
+	parameter_lists.
+	(splite_late_return_type): Remove obsolete hack for giving
+	template template arguments the proper level.
+
 2015-06-24  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/65811
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 98f0fb9..9a1cbd8 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -13273,11 +13273,6 @@ cp_parser_template_parameter_list (cp_parser* parser)
 
   begin_template_parm_list ();
 
-  current_template_parms
-    = tree_cons (size_int (processing_template_decl),
-		 make_tree_vec (0),
-		 current_template_parms);
-
   /* The loop below parses the template parms.  We first need to know
      the total number of template parms to be able to compute proper
      canonical types of each dependent type. So after the loop, when
@@ -13290,7 +13285,6 @@ cp_parser_template_parameter_list (cp_parser* parser)
       bool is_non_type;
       bool is_parameter_pack;
       location_t parm_loc;
-      tree parameter_vec;
 
       /* Parse the template-parameter.  */
       parm_loc = cp_lexer_peek_token (parser->lexer)->location;
@@ -13315,27 +13309,8 @@ cp_parser_template_parameter_list (cp_parser* parser)
 	break;
       /* Otherwise, consume the `,' token.  */
       cp_lexer_consume_token (parser->lexer);
-
-      /* Add the parameter we just processed to current_template_parms.  */
-
-      parameter_vec = make_tree_vec
-	(TREE_VEC_LENGTH (TREE_VALUE (current_template_parms)) + 1);
-
-      for (int i = 0; i < TREE_VEC_LENGTH (parameter_vec) - 1; i++)
-	TREE_VEC_ELT (parameter_vec, i)
-	  = TREE_VEC_ELT (TREE_VALUE (current_template_parms), i);
-
-      TREE_VEC_ELT (parameter_vec, TREE_VEC_LENGTH (parameter_vec) - 1)
-	= tree_last (parameter_list);
-
-      current_template_parms
-	= tree_cons (TREE_PURPOSE (current_template_parms),
-		     parameter_vec,
-		     TREE_CHAIN (current_template_parms));
     }
 
-  current_template_parms = TREE_CHAIN (current_template_parms);
-
   return end_template_parm_list (parameter_list);
 }
 
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 953a4da..8800af8 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3989,6 +3989,21 @@ template_parms_to_args (tree parms)
 	args = a;
     }
 
+    if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
+      /* This can happen for template parms of a template template
+	 parameter, e.g:
+
+	 template<template<class T, class U> class TT> struct S;
+
+	 Consider the level of the parms of TT; T and U both have
+	 level 2; TT has no template parm of level 1. So in this case
+	 the first element of full_template_args is NULL_TREE. If we
+	 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
+	 of 2. This will make tsubst wrongly consider that T and U
+	 have level 1. Instead, let's create a dummy vector as the
+	 first element of full_template_args so that TMPL_ARGS_DEPTH
+	 returns the correct depth for args.  */
+      TREE_VEC_ELT (args, 0) = make_tree_vec (1);
   return args;
 }
 
@@ -4631,9 +4646,6 @@ check_default_tmpl_args (tree decl, tree parms, bool is_primary,
   else
     msg = G_("default argument for template parameter for class enclosing %qD");
 
-  /* By default check everything.  */
-  last_level_to_check = 1;
-
   if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
     /* If we're inside a class definition, there's no need to
        examine the parameters to the class itself.  On the one
@@ -4643,12 +4655,10 @@ check_default_tmpl_args (tree decl, tree parms, bool is_primary,
 	 struct S { template <class U> void f(U); };
        Here the default argument for `S' has no bearing on the
        declaration of `f'.  */
-    last_level_to_check += template_class_depth (current_class_type);
-
-  if (processing_template_parmlist)
-    /* Likewise for parameters outside of the nested parameter list we have
-       just finished defining.  */
-    last_level_to_check += processing_template_parmlist;
+    last_level_to_check = template_class_depth (current_class_type) + 1;
+  else
+    /* Check everything.  */
+    last_level_to_check = 0;
 
   for (parm_level = parms;
        parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
@@ -22382,6 +22392,11 @@ splice_late_return_type (tree type, tree late_return_type)
     return type;
   argvec = make_tree_vec (1);
   TREE_VEC_ELT (argvec, 0) = late_return_type;
+  if (processing_template_parmlist)
+    /* For a late-specified return type in a template type-parameter, we
+       need to add a dummy argument level for its parmlist.  */
+    argvec = add_to_template_args
+      (make_tree_vec (processing_template_parmlist), argvec);
   if (current_template_parms)
     argvec = add_to_template_args (current_template_args (), argvec);
   return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);