From: Junio C Hamano Date: Sun, 08 Jan 2023 07:28:48 GMT Subject: Re: [PATCH v2 2/4] do full type check in BARF_UNLESS_COPYABLE Message-ID: In-Reply-To: <4f161041-b299-f79a-e01b-cc00e2880850@web.de> René Scharfe writes: > Use __builtin_types_compatible_p to perform a full type check if > possible. Otherwise fall back to the old size comparison, but add a > non-evaluated assignment to catch more type mismatches. It doesn't flag > copies between arrays with different signedness, but that's as close to > a full type check as it gets without the builtin, as far as I can see. This seems to unfortunately break builds for compat/mingw.c cf. https://github.com/git/git/actions/runs/3865788736/jobs/6589504628#step:4:374 1848 | COPY_ARRAY(&argv2[1], &argv[1], argc); where the two arrays are "char *const *argv" in the parameter list, and a local variable #ifndef _MSC_VER const #endif char **argv2; It seems that (const char **) and (char **) are compatible but the pointers themselves being const breaks the type compatibility? Perhaps the latter should be "(optionally const) char *const *argv2"?