https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96241
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:da76d98f1d547950e4e344016104a42cff2818de commit r10-8942-gda76d98f1d547950e4e344016104a42cff2818de Author: Marek Polacek <pola...@redhat.com> Date: Thu Oct 15 16:10:45 2020 -0400 c++: Fix verify_ctor_sanity ICE [PR96241] The code added in r10-6437 caused us to create a CONSTRUCTOR when we're {}-initializing an aggregate. Then we pass this new CONSTRUCTOR down to cxx_eval_constant_expression which, if the CONSTRUCTOR isn't TREE_CONSTANT or reduced_constant_expression_p, calls cxx_eval_bare_aggregate. In this case the CONSTRUCTOR wasn't reduced_constant_expression_p because for r_c_e_p a CONST_DECL isn't good enough so it returns false. So we go to cxx_eval_bare_aggregate where we crash, because ctx->ctor wasn't set up properly. So my fix is to do so. Since we're value-initializing, I'm not setting CONSTRUCTOR_NO_CLEARING. To avoid keeping a garbage constructor around, I call free_constructor in case the evaluation did not use it. gcc/cp/ChangeLog: PR c++/96241 * constexpr.c (cxx_eval_array_reference): Set up ctx->ctor if we are initializing an aggregate. Call free_constructor on the new CONSTRUCTOR if it isn't returned from cxx_eval_constant_expression. gcc/testsuite/ChangeLog: PR c++/96241 * g++.dg/cpp0x/constexpr-96241.C: New test. * g++.dg/cpp1y/constexpr-96241.C: New test. (cherry picked from commit 0df73beea03f9dc124dc6e98ec4bdeacca7a2eea)
