https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99132
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:3bfa96895b3219afd93a7038850baef4b63c1f82 commit r11-7279-g3bfa96895b3219afd93a7038850baef4b63c1f82 Author: Jakub Jelinek <ja...@redhat.com> Date: Thu Feb 18 16:21:52 2021 +0100 c++: Fix -std=c++20 ICE on virtual method call [PR99132] On the following testcase we ICE in C++20 mode during cp_get_callee_fndecl -> constexpr evaluation. It is only in C++20 mode on this testcase because virtual methods can't be constexpr in C++17 and earlier and so potential_constant_expression_1 rejects it earlier. And the ICE is caused by genericization changing the h PARM_DECL from having B<C *> type to B<C *> & DECL_BY_REFERENCE and the constexpr evaluation not being able to deal with that. I think this just shows that we shouldn't do the constexpr evaluation during genericization and later, and other spots e.g. during gimplification also don't call cp_get_callee_fndecl but cp_get_callee_fndecl_nofold. After all, cp_fold has already been run and it did the folding if there was any opportunity to do so. And furthermore, what that cp_genericize_r spot does is check for any left-over immediate function calls (which can be ATM just std::source_location::current() call) and immediate functions outside of immediate functions can't have addresses leaked into the IL, so it will be always a direct call anyway. And immediate functions themselves don't make it into genericization/gimplification. 2021-02-18 Jakub Jelinek <ja...@redhat.com> PR c++/99132 * cp-gimplify.c (cp_genericize_r) <case CALL_EXPR>: Use cp_get_callee_fndecl_nofold instead of cp_get_callee_fndecl to check for immediate function calls. * g++.dg/cpp2a/constexpr-virtual18.C: New test.
