[Bug c++/107437] nested generic lambdas fail requiring unneded captures

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107437

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:4cf64d9cc2faf4001f037a50a350abd0f95f3e29

commit r14-2170-g4cf64d9cc2faf4001f037a50a350abd0f95f3e29
Author: Patrick Palka <ppalka@redhat.com>
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<ar, as> ahead of time means we strip it of
    typedefs, yielding m<typename C<i>::q, typename C<j>::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) <case TEMPLATE_ID_EXPR>: 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.