On Fri, Feb 16, 2024 at 10:20:26PM +0100, Jakub Jelinek wrote:
> I've tried that (see below), but am getting
> Excess errors:
> /usr/src/gcc/gcc/testsuite/g++.dg/cpp23/explicit-obj-diagnostics3.C:33:29:
> error: parameter packs not expanded with '...':
And the reason for those is that e.g. on the reduced
struct S0 {
void j(this auto... selves) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
};
with the first posted patch we first do:
if (xobj_param_p && (declarator && declarator->parameter_pack_p))
and clear declarator->parameter_pack_p there.
Then comes
if (parser->implicit_template_parms
&& ((token->type == CPP_ELLIPSIS
&& declarator_can_be_parameter_pack (declarator))
|| (declarator && declarator->parameter_pack_p)))
which is true only with the second patch and not the first.
Adding
if (parser->implicit_template_parms
&& ((token->type == CPP_ELLIPSIS
&& declarator_can_be_parameter_pack (declarator))
- || (declarator && declarator->parameter_pack_p)))
+ || (declarator && declarator->parameter_pack_p && !xobj_param_p)))
{
int latest_template_parm_idx = TREE_VEC_LENGTH
(INNERMOST_TEMPLATE_PARMS (current_template_parms));
fixes some of the excess errors, but not all of them, e.g. on
struct S1 {
void h(this auto&...) {} // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
};
it still remains. The problem in there is that apparently we
need declarator->parameter_pack_p cleared on the xobj diagnostics
iff it was previously set before the CPP_ELLIPSIS handling above it,
but not if it was set in that handling. I'm afraid I have no idea
why though.
The following patch works.
2024-02-16 Jakub Jelinek <ja...@redhat.com>
PR c++/113802
* parser.cc (cp_parser_parameter_declaration): Move the xobj_param_p
pack diagnostics after ellipsis handling, but only clear
declarator->parameter_pack_p for it if it was set before CPP_ELLIPSIS
handling. Ignore declarator->parameter_pack_p if xobj_param_p.
Formatting fix.
* g++.dg/cpp23/explicit-obj-diagnostics3.C (S0, S1, S2, S3, S4): Don't
expect any diagnostics on f and fd member function templates, add
similar templates with ...Selves instead of Selves as k and kd and
expect diagnostics for those.
--- gcc/cp/parser.cc.jj 2024-02-16 17:38:27.802845433 +0100
+++ gcc/cp/parser.cc 2024-02-16 22:42:38.393896067 +0100
@@ -25734,39 +25734,25 @@ cp_parser_parameter_declaration (cp_pars
decl_specifiers.locations[ds_this] = 0;
}
- if (xobj_param_p
- && ((declarator && declarator->parameter_pack_p)
- || cp_lexer_next_token_is (parser->lexer, CPP_ELLIPSIS)))
- {
- location_t xobj_param
- = make_location (decl_specifiers.locations[ds_this],
- decl_spec_token_start->location,
- input_location);
- error_at (xobj_param,
- "an explicit object parameter cannot "
- "be a function parameter pack");
- /* Suppress errors that occur down the line. */
- if (declarator)
- declarator->parameter_pack_p = false;
- }
-
/* If a function parameter pack was specified and an implicit template
parameter was introduced during cp_parser_parameter_declaration,
change any implicit parameters introduced into packs. */
if (parser->implicit_template_parms
&& ((token->type == CPP_ELLIPSIS
&& declarator_can_be_parameter_pack (declarator))
- || (declarator && declarator->parameter_pack_p)))
+ || (declarator && declarator->parameter_pack_p && !xobj_param_p)))
{
int latest_template_parm_idx = TREE_VEC_LENGTH
(INNERMOST_TEMPLATE_PARMS (current_template_parms));
if (latest_template_parm_idx != template_parm_idx)
- decl_specifiers.type = convert_generic_types_to_packs
- (decl_specifiers.type,
- template_parm_idx, latest_template_parm_idx);
+ decl_specifiers.type
+ = convert_generic_types_to_packs (decl_specifiers.type,
+ template_parm_idx,
+ latest_template_parm_idx);
}
+ bool prev_parameter_pack_p = declarator && declarator->parameter_pack_p;
if (cp_lexer_next_token_is (parser->lexer, CPP_ELLIPSIS))
{
tree type = decl_specifiers.type;
@@ -25794,6 +25780,22 @@ cp_parser_parameter_declaration (cp_pars
}
}
+ if (xobj_param_p
+ && (declarator ? declarator->parameter_pack_p
+ : PACK_EXPANSION_P (decl_specifiers.type)))
+ {
+ location_t xobj_param
+ = make_location (decl_specifiers.locations[ds_this],
+ decl_spec_token_start->location,
+ input_location);
+ error_at (xobj_param,
+ "an explicit object parameter cannot "
+ "be a function parameter pack");
+ /* Suppress errors that occur down the line. */
+ if (declarator)
+ declarator->parameter_pack_p = !prev_parameter_pack_p;
+ }
+
/* The restriction on defining new types applies only to the type
of the parameter, not to the default argument. */
parser->type_definition_forbidden_message = saved_message;
--- gcc/testsuite/g++.dg/cpp23/explicit-obj-diagnostics3.C.jj 2024-02-15
20:01:40.349239387 +0100
+++ gcc/testsuite/g++.dg/cpp23/explicit-obj-diagnostics3.C 2024-02-16
21:57:48.269851483 +0100
@@ -24,7 +24,7 @@ void S::f12(this S s = {}) {} // { dg-er
struct S0 {
template<typename Selves>
- void f(this Selves...) {} // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
+ void f(this Selves...) {}
template<typename Selves>
void g(this Selves... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
@@ -32,19 +32,25 @@ struct S0 {
void h(this auto...) {} // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
void j(this auto... selves) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ template<typename ...Selves>
+ void k(this Selves...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+
template<typename Selves>
- void fd(this Selves...); // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
+ void fd(this Selves...);
template<typename Selves>
void gd(this Selves... selves); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
void hd(this auto...); // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
void jd(this auto... selves); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+
+ template<typename ...Selves>
+ void kd(this Selves...); // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
};
struct S1 {
template<typename Selves>
- void f(this Selves&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ void f(this Selves&...) {}
template<typename Selves>
void g(this Selves&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
@@ -52,19 +58,25 @@ struct S1 {
void h(this auto&...) {} // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
void j(this auto&... selves) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ template<typename ...Selves>
+ void k(this Selves&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+
template<typename Selves>
- void fd(this Selves&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ void fd(this Selves&...);
template<typename Selves>
void gd(this Selves&... selves); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
void hd(this auto&...); // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
void jd(this auto&... selves); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+
+ template<typename ...Selves>
+ void kd(this Selves&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
};
struct S2 {
template<typename Selves>
- void f(this Selves&&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ void f(this Selves&&...) {}
template<typename Selves>
void g(this Selves&&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
@@ -72,19 +84,25 @@ struct S2 {
void h(this auto&&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
void j(this auto&&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+ template<typename ...Selves>
+ void k(this Selves&&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+
template<typename Selves>
- void fd(this Selves&&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ void fd(this Selves&&...);
template<typename Selves>
void gd(this Selves&&... selves); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
void hd(this auto&&...); // { dg-error "an explicit object parameter cannot
be a function parameter pack" }
void jd(this auto&&... selves); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+
+ template<typename ...Selves>
+ void kd(this Selves&&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
};
struct S3 {
template<typename Selves>
- void f(this Selves const&...) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+ void f(this Selves const&...) {}
template<typename Selves>
void g(this Selves const&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
@@ -92,19 +110,25 @@ struct S3 {
void h(this auto const&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
void j(this auto const&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+ template<typename ...Selves>
+ void k(this Selves const&...) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+
template<typename Selves>
- void fd(this Selves const&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
+ void fd(this Selves const&...);
template<typename Selves>
void gd(this Selves const&... selves); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
void hd(this auto const&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
void jd(this auto const&... selves); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+
+ template<typename ...Selves>
+ void kd(this Selves const&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
};
struct S4 {
template<typename Selves>
- void f(this Selves const&&...) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+ void f(this Selves const&&...) {}
template<typename Selves>
void g(this Selves const&&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
@@ -112,13 +136,18 @@ struct S4 {
void h(this auto const&&...) {} // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
void j(this auto const&&... selves) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+ template<typename ...Selves>
+ void k(this Selves const&&...) {} // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+
template<typename Selves>
- void fd(this Selves const&&...); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+ void fd(this Selves const&&...);
template<typename Selves>
void gd(this Selves const&&... selves); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
void hd(this auto const&&...); // { dg-error "an explicit object parameter
cannot be a function parameter pack" }
void jd(this auto const&&... selves); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
-};
+ template<typename ...Selves>
+ void kd(this Selves const&&...); // { dg-error "an explicit object
parameter cannot be a function parameter pack" }
+};
Jakub
