https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89442
--- Comment #2 from CVS Commits ---
The master branch has been updated by Patrick Palka :
https://gcc.gnu.org/g:4cf64d9cc2faf4001f037a50a350abd0f95f3e29
commit r14-2170-g4cf64d9cc2faf4001f037a50a350abd0f95f3e29
Author: Patrick Palka
Date: Wed Jun 28 15:43:33 2023 -0400
c++: ahead of time variable template-id coercion [PR89442]
This patch makes us coerce the arguments of a variable template-id ahead
of time, as we do for class template-ids, which causes us to immediately
diagnose template parm/arg kind mismatches and arity mismatches.
Unfortunately this causes a regression in cpp1z/constexpr-if20.C: coercing
the variable template-id m ahead of time means we strip it of
typedefs, yielding m::q, typename C::q>, but in this
stripped form we're directly using 'i' and so we expect to have captured
it. This is a variable template version of PR107437.
PR c++/89442
PR c++/107437
gcc/cp/ChangeLog:
* cp-tree.h (lookup_template_variable): Add complain parameter.
* parser.cc (cp_parser_template_id): Pass tf_warning_or_error
to lookup_template_variable.
* pt.cc (lookup_template_variable): Add complain parameter.
Coerce template arguments here ...
(finish_template_variable): ... instead of here.
(lookup_and_finish_template_variable): Check for error_mark_node
result from lookup_template_variable.
(tsubst_copy) : Pass complain to
lookup_template_variable.
(instantiate_template): Use build2 instead of
lookup_template_variable to build a TEMPLATE_ID_EXPR
for most_specialized_partial_spec.
gcc/testsuite/ChangeLog:
* g++.dg/cpp/pr64127.C: Expect "expected unqualified-id at end
of input" error.
* g++.dg/cpp0x/alias-decl-ttp1.C: Fix template parameter/argument
kind mismatch for variable template has_P_match_V.
* g++.dg/cpp1y/pr72759.C: Expect "template argument 1 is invalid"
error.
* g++.dg/cpp1z/constexpr-if20.C: XFAIL test due to bogus "'i' is
not captured" error.
* g++.dg/cpp1z/noexcept-type21.C: Fix arity of variable template d.
* g++.dg/diagnostic/not-a-function-template-1.C: Add default
template argument to variable template A so that A<> is valid.
* g++.dg/parse/error56.C: Don't expect "ISO C++ forbids
declaration with no type" error.
* g++.dg/parse/template30.C: Don't expect "parse error in
template argument list" error.
* g++.dg/cpp1y/var-templ82.C: New test.
