https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112556
--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Joseph Myers <js...@gcc.gnu.org>: https://gcc.gnu.org/g:3d525fce70fa0ffa0b22af6e213643e1ceca5ab5 commit r15-5431-g3d525fce70fa0ffa0b22af6e213643e1ceca5ab5 Author: Joseph Myers <josmy...@redhat.com> Date: Mon Nov 18 22:24:48 2024 +0000 c: Allow bool and enum null pointer constants [PR112556] As reported in bug 112556, GCC wrongly rejects conversion of null pointer constants with bool or enum type to pointers in convert_for_assignment (assignment, initialization, argument passing, return). Fix the code there to allow BOOLEAN_TYPE and ENUMERAL_TYPE; it already allowed INTEGER_TYPE and BITINT_TYPE. This bug (together with -std=gnu23 meaning false has type bool rather than int) has in turn resulted in people thinking they need to fix code using false as a null pointer constant for C23 compatibility. While such a usage is certainly questionable, it has nothing to do with C23 compatibility and the right place for warnings about such usage is -Wzero-as-null-pointer-constant. I think it would be appropriate to extend -Wzero-as-null-pointer-constant to cover BOOLEAN_TYPE, ENUMERAL_TYPE and BITINT_TYPE (in all the various contexts in which that option generates warnings), though this patch doesn't do anything about that option. Bootstrapped with no regressions for x86-64-pc-linux-gnu. PR c/112556 gcc/c/ * c-typeck.cc (convert_for_assignment): Allow conversion of ENUMERAL_TYPE and BOOLEAN_TYPE null pointer constants to pointers. gcc/testsuite/ * gcc.dg/c11-null-pointer-constant-1.c, gcc.dg/c23-null-pointer-constant-1.c: New tests.
