https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97427
--- Comment #4 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:4a8a0d38b128d36a0cf1ac6a7879307b937418ee commit r10-9204-g4a8a0d38b128d36a0cf1ac6a7879307b937418ee Author: Marek Polacek <pola...@redhat.com> Date: Tue Jan 5 16:27:30 2021 -0500 c++: Fix wrong error with constexpr destructor [PR97427] When I implemented the code to detect modifying const objects in constexpr contexts, we couldn't have constexpr destructors, so I didn't consider them. But now we can and that caused a bogus error in this testcase: [class.dtor]p5 says that "const and volatile semantics are not applied on an object under destruction. They stop being in effect when the destructor for the most derived object starts." so we have to clear the TREE_READONLY flag we set on the object after the constructors have been called to mark it as no-longer-under-construction. In the ~Foo call it's now an object under destruction, so don't report those errors. gcc/cp/ChangeLog: PR c++/97427 * constexpr.c (cxx_set_object_constness): New function. (cxx_eval_call_expression): Set new_obj for destructors too. Call cxx_set_object_constness to set/unset TREE_READONLY of the object under construction/destruction. gcc/testsuite/ChangeLog: PR c++/97427 * g++.dg/cpp2a/constexpr-dtor10.C: New test.
