https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99031
--- Comment #1 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:a8db7887dfbf502b7e60d64bfeebd0de592d2d45 commit r11-7176-ga8db7887dfbf502b7e60d64bfeebd0de592d2d45 Author: Jakub Jelinek <ja...@redhat.com> Date: Wed Feb 10 19:31:15 2021 +0100 c++: Consider addresses of heap artificial vars always non-NULL [PR98988, PR99031] With -fno-delete-null-pointer-checks which is e.g. implied by -fsanitize=undefined or default on some embedded targets, the middle-end folder doesn't consider addresses of global VAR_DECLs to be non-NULL, as one of them could have address 0. Still, I think malloc/operator new (at least the nonthrowing) relies on NULL returns meaning allocation failure rather than success. Furthermore, the artificial VAR_DECLs we create for constexpr new never actually live in the address space of the program, so we can pretend they will never be NULL too. > I'm surprised that nonzero_address has such a limited set of things it will > actually believe have non-zero addresses with > -fno-delete-null-pointer-checks. But it seems that we should be able to > arrange to satisfy > > > if (definition && !DECL_EXTERNAL (decl) > > since these "variables" are indeed defined within the current translation > unit. Doing that seems to work and as added benefit it fixes another PR that has been filed recently. I need to create the varpool node explicitly and call a method that sets the definition member in there, but I can also unregister those varpool nodes at the end of constexpr processing, as the processing ensured they don't leak outside of the processing. 2021-02-10 Jakub Jelinek <ja...@redhat.com> PR c++/98988 PR c++/99031 * constexpr.c: Include cgraph.h. (cxx_eval_call_expression): Call varpool_node::finalize_decl on heap artificial vars. (cxx_eval_outermost_constant_expr): Remove varpool nodes for heap artificial vars. * g++.dg/cpp2a/constexpr-new16.C: New test. * g++.dg/cpp2a/constexpr-new17.C: New test.
