https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99456
--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Unfortunately the #c9 patch caused +FAIL: g++.dg/cpp1y/constexpr-82304.C -std=c++14 (test for errors, line 9) +FAIL: g++.dg/cpp1y/constexpr-82304.C -std=c++17 (test for errors, line 9) +FAIL: g++.dg/cpp1y/constexpr-82304.C -std=c++2a (test for errors, line 9) +FAIL: g++.dg/ext/vla22.C -std=gnu++11 (test for excess errors) +FAIL: g++.dg/ext/vla22.C -std=gnu++14 (test for excess errors) +FAIL: g++.dg/ext/vla22.C -std=gnu++17 (test for excess errors) +FAIL: g++.dg/ext/vla22.C -std=gnu++2a (test for excess errors) +FAIL: g++.dg/template/pr79650.C -std=gnu++11 (test for errors, line 15) +FAIL: g++.dg/template/pr79650.C -std=gnu++11 (test for errors, line 17) +FAIL: g++.dg/template/pr79650.C -std=gnu++14 (test for errors, line 15) +FAIL: g++.dg/template/pr79650.C -std=gnu++14 (test for errors, line 17) +FAIL: g++.dg/template/pr79650.C -std=gnu++17 (test for errors, line 15) +FAIL: g++.dg/template/pr79650.C -std=gnu++17 (test for errors, line 17) +FAIL: g++.dg/template/pr79650.C -std=gnu++2a (test for errors, line 15) +FAIL: g++.dg/template/pr79650.C -std=gnu++2a (test for errors, line 17) regressions. I think the first one is about the non-strict optimizations being applied even to initializers of variables of automatic variables in constexpr functions. I guess we need to avoid doing that before we copy the body for constexpr evaluation purposes. vla22.C emits extra -Wnarrowing warning on the invalid code, dunno, perhaps it is ok to adjust the testcase? And pr79650.C is yet another thing, in that case it is about non-type template argument and the expected error disappearing there.
