Am Montag, 23. September 2024 um 13:10:23 MESZ hat LIU Hao <lh_mo...@126.com> Folgendes geschrieben:
> 在 2024-09-23 18:48, Martin Storsjö 写道: > > Well, as Liu Hao showed, using (void*) casts can get warned about, if we > > compile it with all > > available warning flags. But we don't build mingw-w64-crt that way. > > > > Anyway, Liu Hao, you mentioned that you wanted to try to touch up this > > patch in some way (moving > > some declaration into a header or similar), feel free to pick it up and do > > that. Or should we go > > with it as is, or with a simpler void* which is fine given how > > mingw-w64-crt is compiled in > > practice, or intptr_t? > > We currently have three options: > > 1. Cast the result from `GetProcAddress()` once to `void*`, and let it convert > to the target type implicitly. > 2. Double-cast the result via `void (*)(void)`. > 3. Double-cast the result via `intptr_t`. > > Jacek is suggesting 1, this patch does 2, and my previous suggestion was 3. > > > My concern is that if today a compiler starts to warn about casts between > incompatible function > pointers (which are perfectly okay though), then someday it may start to warn > about implicit > conversions between `void*` and function pointers, and we will have to patch > these casts again. > > 2 is the standard solution, but it looks verbose. I suggest that we move the > `_PVFV` typedef to a > common header, and reuse it. > > 3 is my first suggestion. As with 1 it works in practice, and I believe it > shouldn't cause warnings > in reasonable future. Note that it's also possible to patch gcc to ignore function casts involving FARPROC types, that's what I did in my gcc build: From: Hannes Domani <ssb...@yahoo.de> Date: Sun, 28 Mar 2021 14:35:56 +0200 Subject: [PATCH] Don't warn for function casts involving FARPROC --- gcc/c/c-typeck.cc | 5 +++++ gcc/cp/typeck.cc | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc index 4567b114734..43c974597ef 100644 --- a/gcc/c/c-typeck.cc +++ b/gcc/c/c-typeck.cc @@ -6131,6 +6131,11 @@ c_safe_function_type_cast_p (tree t1, tree t2) TYPE_ARG_TYPES (t2) == void_list_node) return true; + /* FARPROC */ + if (TREE_CODE (TYPE_MAIN_VARIANT (TREE_TYPE (t2))) == INTEGER_TYPE && + TYPE_ARG_TYPES (t2) == NULL_TREE) + return true; + if (!c_safe_arg_type_equiv_p (TREE_TYPE (t1), TREE_TYPE (t2))) return false; diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc index 21436f836fa..5b31f8c8b0f 100644 --- a/gcc/cp/typeck.cc +++ b/gcc/cp/typeck.cc @@ -1399,6 +1399,11 @@ cxx_safe_function_type_cast_p (tree t1, tree t2) TYPE_ARG_TYPES (t2) == void_list_node) return true; + /* FARPROC */ + if (TREE_CODE (TYPE_MAIN_VARIANT (TREE_TYPE (t2))) == INTEGER_TYPE && + TYPE_ARG_TYPES (t2) == void_list_node) + return true; + if (!cxx_safe_arg_type_equiv_p (TREE_TYPE (t1), TREE_TYPE (t2))) return false; -- 2.39.1.windows.1 _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
