re PR c++/53498 (Compiler crashes during C++11 template magic compilation)

	PR c++/53498
	PR c++/53305
	* pt.c (tsubst_decl) [PARM_DECL]: Don't recurse into DECL_CHAIN
	if cp_unevaluated_operand is set.
	(tsubst_copy) [PARM_DECL]: Don't copy before tsubsting.

From-SVN: r188973

gcc/cp/ChangeLog

 2012-06-25  Jason Merrill  <jason@redhat.com>
 
+	PR c++/53498
+	PR c++/53305
+	* pt.c (tsubst_decl) [PARM_DECL]: Don't recurse into DECL_CHAIN
+	if cp_unevaluated_operand is set.
+	(tsubst_copy) [PARM_DECL]: Don't copy before tsubsting.
+
 	PR c++/52988
 	* typeck.c (decay_conversion): Don't discard side-effects from
 	expressions of nullptr_t.

gcc/cp/pt.c

@@ -10497,7 +10497,9 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
               DECL_CHAIN (prev_r) = r;
           }
 
-	if (DECL_CHAIN (t))
+	/* If cp_unevaluated_operand is set, we're just looking for a
+	   single dummy parameter, so don't keep going.  */
+	if (DECL_CHAIN (t) && !cp_unevaluated_operand)
 	  DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
 				   complain, DECL_CHAIN (t));
 
@@ -12078,8 +12080,6 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 
       if (r == NULL_TREE)
 	{
-	  tree c;
-
 	  /* We get here for a use of 'this' in an NSDMI.  */
 	  if (DECL_NAME (t) == this_identifier
 	      && at_function_scope_p ()
@@ -12090,12 +12090,7 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	     declaration (such as in a late-specified return type).  Just
 	     make a dummy decl, since it's only used for its type.  */
 	  gcc_assert (cp_unevaluated_operand != 0);
-	  /* We copy T because want to tsubst the PARM_DECL only,
-	     not the following PARM_DECLs that are chained to T.  */
-	  c = copy_node (t);
-	  r = tsubst_decl (c, args, complain);
-	  if (r == NULL_TREE)
-	    return error_mark_node;
+	  r = tsubst_decl (t, args, complain);
 	  /* Give it the template pattern as its context; its true context
 	     hasn't been instantiated yet and this is good enough for
 	     mangling.  */

gcc/testsuite/ChangeLog

+2012-06-25  Jason Merrill  <jason@redhat.com>
+
+	PR c++/53498
+	PR c++/53305
+	* g++.dg/cpp0x/decltype38.C: New.
+	* g++.dg/cpp0x/variadic132.C: Remove dg-error.
+
 2012-06-25  Janis Johnson  <janisjo@codesourcery.com>
 
 	* lib/target-supports-dg.exp (testname-for-summary): New.

gcc/testsuite/g++.dg/cpp0x/decltype38.C

+// PR c++/53498
+// { dg-do compile { target c++11 } }
+
+template<typename... Args>
+struct B
+{
+  template<typename U>
+  static
+  void b(const U& u, const Args&... args,
+	 decltype(u.f(args...)) dummy)
+  {
+  }
+};
+
+int main() {
+  B<int> b;
+}

gcc/testsuite/g++.dg/cpp0x/variadic132.C

@@ -9,11 +9,11 @@ struct funct
   int operator()(argTs...);
 };
 
-template<class...> class test;
+template<class...> struct test;
 
 template<template <class...> class tp,
 	 class... arg1Ts, class... arg2Ts>
-class test<tp<arg1Ts...>, tp<arg2Ts...>>
+struct test<tp<arg1Ts...>, tp<arg2Ts...>>
 {
   template<class func, class...arg3Ts>
     auto test2(func fun, arg1Ts... arg1s, arg3Ts... arg3s)
@@ -23,5 +23,5 @@ class test<tp<arg1Ts...>, tp<arg2Ts...>>
 int main()
 {
   test<tuple<>, tuple<char,int>> t2;
-  t2.test2(funct(), 'a', 2);  // { dg-error "no matching function" }
+  t2.test2(funct(), 'a', 2);
 }