https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82099
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:af362af18f405c34840d820143aa3a94f72fce4d commit r11-6476-gaf362af18f405c34840d820143aa3a94f72fce4d Author: Marek Polacek <pola...@redhat.com> Date: Thu Dec 10 15:00:58 2020 -0500 c++: ICE with deferred noexcept when deducing targs [PR82099] In this test we ICE in type_throw_all_p because it got a deferred noexcept which it shouldn't. Here's the story: In noexcept61.C, we call bar, so we perform overload resolution. When adding the (only) candidate, we need to deduce template arguments, so call fn_type_unification as usually. That deduces U to void (*) (int &, int &) which is correct, but its noexcept-spec is deferred_noexcept. Then we call add_function_candidate (bar), wherein we try to create an implicit conversion sequence for every argument. Since baz<int> is of unknown type, we instantiate_type it; it is a TEMPLATE_ID_EXPR so that calls resolve_address_of_overloaded_function. But we crash there, because target_type contains the deferred_noexcept. So we need to maybe_instantiate_noexcept before we can compare types. resolve_overloaded_unification seemed like the appropriate spot, now fn_type_unification produces the function type with its noexcept-spec instantiated. This shouldn't go against CWG 1330 because here we really need to instantiate the noexcept-spec. This also fixes class-deduction76.C, a dg-ice test I recently added, therefore this fix also fixes c++/90799, yay. gcc/cp/ChangeLog: PR c++/82099 * pt.c (resolve_overloaded_unification): Call maybe_instantiate_noexcept after instantiating the function decl. gcc/testsuite/ChangeLog: PR c++/82099 * g++.dg/cpp1z/class-deduction76.C: Remove dg-ice. * g++.dg/cpp0x/noexcept61.C: New test.
