c++: Fix up parameter pack diagnostics on xobj vs. varargs functions [PR113802]

The simple presence of ellipsis as next token after the parameter
declaration doesn't imply it is a parameter pack, it sometimes is, e.g.
if its type is a pack, but sometimes is not and in that case it acts
the same as if the next tokens were , ... instead of just ...
The xobj param cannot be a function parameter pack though treats both
the declarator->parameter_pack_p and token->type == CPP_ELLIPSIS as
sufficient conditions for the error.  The conditions for CPP_ELLIPSIS
are done a little bit later in the same function and complex enough that
IMHO shouldn't be repeated, on the other side for the
declarator->parameter_pack_p case we clear that flag for xobj params
for error recovery reasons.

This patch just moves the diagnostics later (after the CPP_ELLIPSIS handling)
and changes the error recovery behavior by pretending the this specifier
didn't appear if an error is reported.

2024-03-08  Jakub Jelinek  <jakub@redhat.com>

	PR c++/113802
	* parser.cc (cp_parser_parameter_declaration): Move the xobj_param_p
	pack diagnostics after ellipsis handling and if an error is reported,
	pretend this specifier didn't appear.  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.  Expect extra diagnostics in error
	recovery for g and gd member function templates.

0 files changed, 0 insertions, 0 deletions