[Bug c++/57943] [c++11] invalid decltype expression accepted in template default type

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57943

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>:

https://gcc.gnu.org/g:115232b778943be075fc4df991e03d9387563114

commit r11-434-g115232b778943be075fc4df991e03d9387563114
Author: Patrick Palka <ppa...@redhat.com>
Date:   Fri May 15 18:51:11 2020 -0400

    c++: decltype of invalid non-dependent expr [PR57943]

    We sometimes fail to reject an invalid non-dependent operand to decltype
    when inside a template, because finish_decltype_type resolves the
    decltype to the TREE_TYPE of the operand before we ever instantiate and
    fully process the operand.  Fix this by adding a call to
    instantiate_non_dependent_expr_sfinae in finish_decltype_type.

    gcc/cp/ChangeLog:

            PR c++/57943
            * semantics.c (finish_decltype_type): Call
            instantiate_non_dependent_expr_sfinae on the expression.

    gcc/testsuite/ChangeLog:

            PR c++/57943
            * g++.dg/cpp0x/decltype76.C: New test.