pt.c (tsubst_copy): Cope with tsubst_pack_expansion returning a pack expansion...

2008-03-27  Douglas Gregor  <doug.gregor@gmail.com>

	* pt.c (tsubst_copy) <case SIZEOF_EXPR>: Cope with
	tsubst_pack_expansion returning a pack expansion, or a TREE_VEC
	ending in a pack expansion, both of which can occur when
	substituting into a nested template.
	(tsubst_copy_and_build) <case SIZEOF_EXPR>: When we're
	instantiating the sizeof...(X) form, make tsubst_copy do the work.
	* parser.c (cp_parser_template_parameter): Deal with unnamed
	non-type template parameter packs identified by pack expansions in
	the parameter type.

2008-03-27  Douglas Gregor  <doug.gregor@gmail.com>

       * g++.dg/cpp0x/variadic91.C: New.

From-SVN: r133642

gcc/cp/ChangeLog

+2008-03-27  Douglas Gregor  <doug.gregor@gmail.com>
+
+	* pt.c (tsubst_copy) <case SIZEOF_EXPR>: Cope with
+	tsubst_pack_expansion returning a pack expansion, or a TREE_VEC
+	ending in a pack expansion, both of which can occur when
+	substituting into a nested template.
+	(tsubst_copy_and_build) <case SIZEOF_EXPR>: When we're
+	instantiating the sizeof...(X) form, make tsubst_copy do the work.
+	* parser.c (cp_parser_template_parameter): Deal with unnamed
+	non-type template parameter packs identified by pack expansions in
+	the parameter type.
+
 2008-03-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/35546

gcc/cp/parser.c

@@ -9435,29 +9435,41 @@ cp_parser_template_parameter (cp_parser* parser, bool *is_non_type,
       maybe_warn_variadic_templates ();
       
       *is_parameter_pack = true;
+    }
+  /* We might end up with a pack expansion as the type of the non-type
+     template parameter, in which case this is a non-type template
+     parameter pack.  */
+  else if (parameter_declarator
+	   && parameter_declarator->decl_specifiers.type
+	   && PACK_EXPANSION_P (parameter_declarator->decl_specifiers.type))
+    {
+      *is_parameter_pack = true;
+      parameter_declarator->decl_specifiers.type = 
+	PACK_EXPANSION_PATTERN (parameter_declarator->decl_specifiers.type);
+    }
 
+  if (*is_parameter_pack && cp_lexer_next_token_is (parser->lexer, CPP_EQ))
+    {
       /* Parameter packs cannot have default arguments.  However, a
 	 user may try to do so, so we'll parse them and give an
 	 appropriate diagnostic here.  */
-      if (cp_lexer_next_token_is (parser->lexer, CPP_EQ))
-	{
-	  /* Consume the `='.  */
-	  cp_lexer_consume_token (parser->lexer);
 
-	  /* Find the name of the parameter pack.  */     
-	  id_declarator = parameter_declarator->declarator;
-	  while (id_declarator && id_declarator->kind != cdk_id)
-	    id_declarator = id_declarator->declarator;
-	  
-	  if (id_declarator && id_declarator->kind == cdk_id)
-	    error ("template parameter pack %qD cannot have a default argument",
-		   id_declarator->u.id.unqualified_name);
-	  else
-	    error ("template parameter pack cannot have a default argument");
-
-          /* Parse the default argument, but throw away the result.  */
-          cp_parser_default_argument (parser, /*template_parm_p=*/true);
-	}
+      /* Consume the `='.  */
+      cp_lexer_consume_token (parser->lexer);
+      
+      /* Find the name of the parameter pack.  */     
+      id_declarator = parameter_declarator->declarator;
+      while (id_declarator && id_declarator->kind != cdk_id)
+	id_declarator = id_declarator->declarator;
+      
+      if (id_declarator && id_declarator->kind == cdk_id)
+	error ("template parameter pack %qD cannot have a default argument",
+	       id_declarator->u.id.unqualified_name);
+      else
+	error ("template parameter pack cannot have a default argument");
+      
+      /* Parse the default argument, but throw away the result.  */
+      cp_parser_default_argument (parser, /*template_parm_p=*/true);
     }
 
   parm = grokdeclarator (parameter_declarator->declarator,

gcc/cp/pt.c

@@ -9916,9 +9916,30 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
           /* We only want to compute the number of arguments.  */
           tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
                                                 complain, in_decl);
+	  int len;
+
+	  if (TREE_CODE (expanded) == TREE_VEC)
+	    len = TREE_VEC_LENGTH (expanded);
+
 	  if (expanded == error_mark_node)
 	    return error_mark_node;
-          return build_int_cst (size_type_node, TREE_VEC_LENGTH (expanded));
+	  else if (PACK_EXPANSION_P (expanded)
+		   || (TREE_CODE (expanded) == TREE_VEC
+		       && len > 0
+		       && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
+	    {
+	      if (TREE_CODE (expanded) == TREE_VEC)
+		expanded = TREE_VEC_ELT (expanded, len - 1);
+
+	      if (TYPE_P (expanded))
+		return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR, 
+						   complain & tf_error);
+	      else
+		return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
+                                                   complain & tf_error);
+	    }
+	  else
+	    return build_int_cst (size_type_node, len);
         }
       /* Fall through */
 
@@ -10918,14 +10939,7 @@ tsubst_copy_and_build (tree t,
 
     case SIZEOF_EXPR:
       if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
-        {
-          /* We only want to compute the number of arguments.  */
-          tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
-                                                complain, in_decl);
-	  if (expanded == error_mark_node)
-	    return error_mark_node;
-          return build_int_cst (size_type_node, TREE_VEC_LENGTH (expanded));
-        }
+	return tsubst_copy (t, args, complain, in_decl);
       /* Fall through */
       
     case ALIGNOF_EXPR:
@@ -12920,7 +12934,7 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict)
 	    tree parmvec = TYPE_TI_ARGS (parm);
 	    tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
 	    tree parm_parms 
-	      = DECL_INNERMOST_TEMPLATE_PARMS 
+              = DECL_INNERMOST_TEMPLATE_PARMS
 	          (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
 	    int i, len;
             int parm_variadic_p = 0;

gcc/testsuite/ChangeLog

+2008-03-27  Douglas Gregor  <doug.gregor@gmail.com>
+
+       * g++.dg/cpp0x/variadic91.C: New.
+
 2008-03-27  Zdenek Dvorak  <ook@ucw.cz>
 
 	* gcc.dg/tree-ssa/loop-32.c: New testcase.

gcc/testsuite/g++.dg/cpp0x/variadic91.C

+// { dg-options "-std=c++0x" }
+template<int N> struct Int2Type { };
+
+template<typename... T>
+struct Outer {
+  template<typename... U>
+  void foo(Int2Type<sizeof...(T)>, Int2Type<sizeof...(U)>);
+};
+
+
+Outer<short, int, long> outer;
+
+void g4() {
+  outer.foo<float, double>(Int2Type<3>(), Int2Type<2>());
+}
+
+template<typename... T, template<T...> class X> void f1();