[C++ Patch] PR 69095

[C++ Patch] PR 69095

[Paolo Carlini]

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Hi,

finally sending a patch for this issue. As noticed by submitter himself, 
it appears to boil down to a rather straightforward case of not 
rejecting unexpanded parameter packs in default arguments. In order to 
handle all the combinations (in/out of class, template 
parameter/function parameter) I added calls of 
check_for_bare_parameter_packs both to cp_parser_default_argument and 
cp_parser_late_parsing_default_args (to have a meaningful location for 
the latter, the patchlet which I sent earlier today is a must). Tested 
x86_64-linux.

Thanks,
Paolo.

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/cp
2016-05-22  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/69095
	* parser.c (cp_parser_default_argument): Call
	check_for_bare_parameter_packs.
	(cp_parser_late_parsing_default_args): Likewise.

/testsuite
2016-05-22  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/69095
	* g++.dg/cpp0x/variadic168.C: New.

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Index: cp/parser.c
===================================================================
--- cp/parser.c	(revision 236569)
+++ cp/parser.c	(working copy)
@@ -20673,6 +20673,8 @@ cp_parser_default_argument (cp_parser *parser, boo
     }
   if (BRACE_ENCLOSED_INITIALIZER_P (default_argument))
     maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
+  if (check_for_bare_parameter_packs (default_argument))
+    default_argument = error_mark_node;
   if (template_parm_p)
     pop_deferring_access_checks ();
   parser->greater_than_is_operator_p = saved_greater_than_is_operator_p;
@@ -26403,6 +26405,9 @@ cp_parser_late_parsing_default_args (cp_parser *pa
 	  continue;
 	}
 
+      if (check_for_bare_parameter_packs (parsed_arg))
+	parsed_arg = error_mark_node;
+
       TREE_PURPOSE (parm) = parsed_arg;
 
       /* Update any instantiations we've already created.  */
Index: testsuite/g++.dg/cpp0x/variadic168.C
===================================================================
--- testsuite/g++.dg/cpp0x/variadic168.C	(revision 0)
+++ testsuite/g++.dg/cpp0x/variadic168.C	(working copy)
@@ -0,0 +1,18 @@
+// PR c++/69095
+// { dg-do compile { target c++11 } }
+
+struct B1 {
+  template <typename Ret, typename... Args, unsigned = sizeof(Args)> // { dg-error "parameter packs not expanded" }
+  void insert(Ret);
+};
+
+struct B2 {
+  template <typename Ret, typename... Args>
+  void insert(Ret, unsigned = sizeof(Args)); // { dg-error "parameter packs not expanded" }
+};
+
+template <typename Ret, typename... Args, unsigned = sizeof(Args)> // { dg-error "parameter packs not expanded" }
+void insert1(Ret);
+
+template <typename Ret, typename... Args>
+void insert2(Ret, unsigned = sizeof(Args)); // { dg-error "parameter packs not expanded" }

Re: [C++ Patch] PR 69095

[Jason Merrill]

On 05/22/2016 02:26 PM, Paolo Carlini wrote:
> finally sending a patch for this issue. As noticed by submitter himself,
> it appears to boil down to a rather straightforward case of not
> rejecting unexpanded parameter packs in default arguments. In order to
> handle all the combinations (in/out of class, template
> parameter/function parameter) I added calls of
> check_for_bare_parameter_packs both to cp_parser_default_argument and
> cp_parser_late_parsing_default_args

Hmm, would it make sense to check in cp_parser_initializer?

Jason

Re: [C++ Patch] PR 69095

[Paolo Carlini]

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Hi,

On 23/05/2016 15:32, Jason Merrill wrote:
> On 05/22/2016 02:26 PM, Paolo Carlini wrote:
>> finally sending a patch for this issue. As noticed by submitter himself,
>> it appears to boil down to a rather straightforward case of not
>> rejecting unexpanded parameter packs in default arguments. In order to
>> handle all the combinations (in/out of class, template
>> parameter/function parameter) I added calls of
>> check_for_bare_parameter_packs both to cp_parser_default_argument and
>> cp_parser_late_parsing_default_args
>
> Hmm, would it make sense to check in cp_parser_initializer?
Oh yes. The below is already past g++.dg/tm...

Thanks!
Paolo.

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Index: cp/parser.c
===================================================================
--- cp/parser.c	(revision 236592)
+++ cp/parser.c	(working copy)
@@ -20800,6 +20800,9 @@ cp_parser_initializer (cp_parser* parser, bool* is
       init = error_mark_node;
     }
 
+  if (check_for_bare_parameter_packs (init))
+    init = error_mark_node;
+
   return init;
 }
 
Index: testsuite/g++.dg/cpp0x/variadic168.C
===================================================================
--- testsuite/g++.dg/cpp0x/variadic168.C	(revision 0)
+++ testsuite/g++.dg/cpp0x/variadic168.C	(working copy)
@@ -0,0 +1,18 @@
+// PR c++/69095
+// { dg-do compile { target c++11 } }
+
+struct B1 {
+  template <typename Ret, typename... Args, unsigned = sizeof(Args)> // { dg-error "parameter packs not expanded" }
+  void insert(Ret);
+};
+
+struct B2 {
+  template <typename Ret, typename... Args>
+  void insert(Ret, unsigned = sizeof(Args)); // { dg-error "parameter packs not expanded" }
+};
+
+template <typename Ret, typename... Args, unsigned = sizeof(Args)> // { dg-error "parameter packs not expanded" }
+void insert1(Ret);
+
+template <typename Ret, typename... Args>
+void insert2(Ret, unsigned = sizeof(Args)); // { dg-error "parameter packs not expanded" }

Re: [C++ Patch] PR 69095

[Jason Merrill]

On 05/23/2016 11:25 AM, Paolo Carlini wrote:
> On 23/05/2016 15:32, Jason Merrill wrote:
>> On 05/22/2016 02:26 PM, Paolo Carlini wrote:
>>> finally sending a patch for this issue. As noticed by submitter himself,
>>> it appears to boil down to a rather straightforward case of not
>>> rejecting unexpanded parameter packs in default arguments. In order to
>>> handle all the combinations (in/out of class, template
>>> parameter/function parameter) I added calls of
>>> check_for_bare_parameter_packs both to cp_parser_default_argument and
>>> cp_parser_late_parsing_default_args
>>
>> Hmm, would it make sense to check in cp_parser_initializer?
> Oh yes. The below is already past g++.dg/tm...

OK if testing passes.

Jason