| Message ID | CADzB+2m4o-ADUwUh3bgQ8yvQnLVxUkRRmP8u9QB5h6JBZFRm2Q@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | C++ PATCH for c++/85264, ICE with extra template parameter list | expand |
Hi, On 09/04/2018 21:39, Jason Merrill wrote: > cp_parser_check_template_parameters is supposed to catch when we have > the wrong number of template parameter lists, but it wasn't diagnosing > this case. Fixed by checking whether the thing we're declaring used a > template-id; the case of declaring a primary template, when we allow > one more template parameter list, uses a plain identifier. Nice, it looks like this also fixes the prehistoric c++/24314, which I still had assigned. When I worked a bit on it, relatively recently, in 2012, I failed to properly follow-up to your feedback on the mailing list, but I don't think we really nailed the problem, did we? https://gcc.gnu.org/ml/gcc-patches/2012-09/msg00504.html Or maybe we just tried to do too much, like doing away completely with cp_parser_check_template_parameters in favor of a bit of additional checking in maybe_process_partial_specialization. Paolo.
On Mon, Apr 9, 2018 at 6:55 PM, Paolo Carlini <paolo.carlini@oracle.com> wrote: > On 09/04/2018 21:39, Jason Merrill wrote: >> >> cp_parser_check_template_parameters is supposed to catch when we have >> the wrong number of template parameter lists, but it wasn't diagnosing >> this case. Fixed by checking whether the thing we're declaring used a >> template-id; the case of declaring a primary template, when we allow >> one more template parameter list, uses a plain identifier. > > Nice, it looks like this also fixes the prehistoric c++/24314, which I still > had assigned. Great! > When I worked a bit on it, relatively recently, in 2012, I > failed to properly follow-up to your feedback on the mailing list, but I > don't think we really nailed the problem, did we? > > https://gcc.gnu.org/ml/gcc-patches/2012-09/msg00504.html > > Or maybe we just tried to do too much, like doing away completely with > cp_parser_check_template_parameters in favor of a bit of additional checking > in maybe_process_partial_specialization. I'm sure late checking like we discussed there can also work, but this ended up being a simple way to make the current code work better... Jason
On Tue, Apr 10, 2018 at 9:50 AM, Jason Merrill <jason@redhat.com> wrote: > On Mon, Apr 9, 2018 at 6:55 PM, Paolo Carlini <paolo.carlini@oracle.com> wrote: >> On 09/04/2018 21:39, Jason Merrill wrote: >>> >>> cp_parser_check_template_parameters is supposed to catch when we have >>> the wrong number of template parameter lists, but it wasn't diagnosing >>> this case. Fixed by checking whether the thing we're declaring used a >>> template-id; the case of declaring a primary template, when we allow >>> one more template parameter list, uses a plain identifier. >> >> Nice, it looks like this also fixes the prehistoric c++/24314, which I still >> had assigned. > > Great! > >> When I worked a bit on it, relatively recently, in 2012, I >> failed to properly follow-up to your feedback on the mailing list, but I >> don't think we really nailed the problem, did we? >> >> https://gcc.gnu.org/ml/gcc-patches/2012-09/msg00504.html >> >> Or maybe we just tried to do too much, like doing away completely with >> cp_parser_check_template_parameters in favor of a bit of additional checking >> in maybe_process_partial_specialization. > > I'm sure late checking like we discussed there can also work, but this > ended up being a simple way to make the current code work better... But as discussed in that thread, we should still improve the comment: commit 2072134d123d64535baac00ea4bb6ffbce045caf Author: Jason Merrill <jason@redhat.com> Date: Tue Apr 10 09:42:54 2018 -0400 * parser.c (cp_parser_check_template_parameters): Improve comment. diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index d4b62c75c44..849a75a1a51 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -26452,8 +26452,8 @@ cp_parser_check_template_parameters (cp_parser* parser, lists, that's OK. */ if (parser->num_template_parameter_lists == num_templates) return true; - /* If there are more, but only one more, then we are referring to a - member template. That's OK too. */ + /* If there are more, but only one more, and the name ends in an identifier, + then we are declaring a primary template. That's OK too. */ if (!template_id_p && parser->num_template_parameter_lists == num_templates + 1) return true;
commit 770f6eaf7320d908cd39ace3aa155e7ec829982d
Author: Jason Merrill <jason@redhat.com>
Date: Mon Apr 9 14:03:15 2018 -0400
PR c++/85264 - ICE with excess template-parameter-list.
* parser.c (cp_parser_check_template_parameters): Add template_id_p
parameter. Don't allow an extra template header if true.
(cp_parser_class_head): Pass template_id_p.
(cp_parser_elaborated_type_specifier): Likewise.
(cp_parser_alias_declaration): Likewise.
(cp_parser_check_declarator_template_parameters): Likewise.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 0ffa13de537..0e469259008 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -2498,7 +2498,7 @@ static tree cp_parser_maybe_treat_template_as_class
static bool cp_parser_check_declarator_template_parameters
(cp_parser *, cp_declarator *, location_t);
static bool cp_parser_check_template_parameters
- (cp_parser *, unsigned, location_t, cp_declarator *);
+ (cp_parser *, unsigned, bool, location_t, cp_declarator *);
static cp_expr cp_parser_simple_cast_expression
(cp_parser *);
static tree cp_parser_global_scope_opt
@@ -17917,6 +17917,7 @@ cp_parser_elaborated_type_specifier (cp_parser* parser,
if (template_parm_lists_apply
&& !cp_parser_check_template_parameters (parser,
/*num_templates=*/0,
+ /*template_id*/false,
token->location,
/*declarator=*/NULL))
return error_mark_node;
@@ -18971,6 +18972,7 @@ cp_parser_alias_declaration (cp_parser* parser)
if (parser->num_template_parameter_lists
&& !cp_parser_check_template_parameters (parser,
/*num_templates=*/0,
+ /*template_id*/false,
id_location,
/*declarator=*/NULL))
return error_mark_node;
@@ -23117,6 +23119,7 @@ cp_parser_class_head (cp_parser* parser,
/* Make sure that the right number of template parameters were
present. */
if (!cp_parser_check_template_parameters (parser, num_templates,
+ template_id_p,
type_start_token->location,
/*declarator=*/NULL))
{
@@ -26391,17 +26394,22 @@ cp_parser_check_declarator_template_parameters (cp_parser* parser,
{
unsigned num_templates = 0;
tree scope = declarator->u.id.qualifying_scope;
+ bool template_id_p = false;
if (scope)
num_templates = num_template_headers_for_class (scope);
else if (TREE_CODE (declarator->u.id.unqualified_name)
== TEMPLATE_ID_EXPR)
- /* If the DECLARATOR has the form `X<y>' then it uses one
- additional level of template parameters. */
- ++num_templates;
+ {
+ /* If the DECLARATOR has the form `X<y>' then it uses one
+ additional level of template parameters. */
+ ++num_templates;
+ template_id_p = true;
+ }
return cp_parser_check_template_parameters
- (parser, num_templates, declarator_location, declarator);
+ (parser, num_templates, template_id_p, declarator_location,
+ declarator);
}
case cdk_function:
@@ -26430,6 +26438,7 @@ cp_parser_check_declarator_template_parameters (cp_parser* parser,
static bool
cp_parser_check_template_parameters (cp_parser* parser,
unsigned num_templates,
+ bool template_id_p,
location_t location,
cp_declarator *declarator)
{
@@ -26439,7 +26448,8 @@ cp_parser_check_template_parameters (cp_parser* parser,
return true;
/* If there are more, but only one more, then we are referring to a
member template. That's OK too. */
- if (parser->num_template_parameter_lists == num_templates + 1)
+ if (!template_id_p
+ && parser->num_template_parameter_lists == num_templates + 1)
return true;
/* If there are more template classes than parameter lists, we have
something like:
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic176.C b/gcc/testsuite/g++.dg/cpp0x/variadic176.C
new file mode 100644
index 00000000000..1d6e3c2f10a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic176.C
@@ -0,0 +1,10 @@
+// PR c++/85264
+// { dg-do compile { target c++11 } }
+
+template<typename> struct A {};
+
+template<int>
+template<typename... T>
+struct A<void(T...)> {}; // { dg-error "too many template-parameter-lists" }
+
+A<void(int)> a;