https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178
--- Comment #28 from GCC 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:622968990beee7499e951590258363545b4a3b57 commit r15-7900-g622968990beee7499e951590258363545b4a3b57 Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Mar 7 23:59:34 2025 +0100 c: do not warn about truncating NUL char when initializing nonstring arrays [PR117178] When initializing a nonstring char array when compiled with -Wunterminated-string-initialization the warning trips even when truncating the trailing NUL character from the string constant. Only warn about this when running under -Wc++-compat since under C++ we should not initialize nonstrings from C strings. This patch separates the -Wunterminated-string-initialization and -Wc++-compat warnings, they are now independent option, the former implied by -Wextra, the latter not implied by anything. If -Wc++-compat is in effect, it takes precedence over -Wunterminated-string-initialization and warns regardless of nonstring attribute, otherwise if -Wunterminated-string-initialization is enabled, it warns only if there isn't nonstring attribute. In all cases, the warnings and also pedwarn_init for even larger sizes now provide details on the lengths. 2025-03-07 Kees Cook <k...@kernel.org> Jakub Jelinek <ja...@redhat.com> PR c/117178 gcc/ * doc/invoke.texi (Wunterminated-string-initialization): Document the new interaction between this warning and -Wc++-compat and that initialization of decls with nonstring attribute aren't warned about. gcc/c-family/ * c.opt (Wunterminated-string-initialization): Don't depend on -Wc++-compat. gcc/c/ * c-typeck.cc (digest_init): Add DECL argument. Adjust wording of pedwarn_init for too long strings and provide details on the lengths, for string literals where just the trailing NULL doesn't fit warn for warn_cxx_compat with OPT_Wc___compat, wording which mentions "for C++" and provides details on lengths, otherwise for warn_unterminated_string_initialization adjust the warning, provide details on lengths and don't warn if get_attr_nonstring_decl (decl). (build_c_cast, store_init_value, output_init_element): Adjust digest_init callers. gcc/testsuite/ * gcc.dg/Wunterminated-string-initialization.c: Add additional test coverage. * gcc.dg/Wcxx-compat-14.c: Check in dg-warning for "for C++" part of the diagnostics. * gcc.dg/Wcxx-compat-23.c: New test. * gcc.dg/Wcxx-compat-24.c: New test. Signed-off-by: Kees Cook <k...@kernel.org>
