https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #25 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-14 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:a805de33f7be4f6886906ca5f4da493f3b743c76 commit r14-10193-ga805de33f7be4f6886906ca5f4da493f3b743c76 Author: Jakub Jelinek <ja...@redhat.com> Date: Fri May 10 09:21:38 2024 +0200 c++, mingw: Fix up types of dtor hooks to __cxa_{,thread_}atexit/__cxa_throw on mingw ia32 [PR114968] __cxa_atexit/__cxa_thread_atexit/__cxa_throw functions accept function pointers to usually directly destructors rather than wrappers around them. Now, mingw ia32 uses implicitly __attribute__((thiscall)) calling conventions for METHOD_TYPE (where the this pointer is passed in %ecx register, the rest on the stack), so these functions use: in config/os/mingw32/os_defines.h: #if defined (__i386__) #define _GLIBCXX_CDTOR_CALLABI __thiscall #endif in libsupc++/cxxabi.h __cxa_atexit(void (_GLIBCXX_CDTOR_CALLABI *)(void*), void*, void*) _GLIBCXX_NOTHROW; __cxa_thread_atexit(void (_GLIBCXX_CDTOR_CALLABI *)(void*), void*, void *) _GLIBCXX_NOTHROW; __cxa_throw(void*, std::type_info*, void (_GLIBCXX_CDTOR_CALLABI *) (void *)) __attribute__((__noreturn__)); Now, mingw for some weird reason uses #define TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT hook_bool_void_true so it never actually uses __cxa_atexit, but does use __cxa_thread_atexit and __cxa_throw. Recent changes for modules result in more detailed __cxa_*atexit/__cxa_throw prototypes precreated by the compiler, and if that happens and one also includes <cxxabi.h>, the compiler complains about mismatches in the prototypes. One thing is the missing thiscall attribute on the FUNCTION_TYPE, the other problem is that all of atexit/__cxa_atexit/__cxa_thread_atexit get function pointer types created by a single function, get_atexit_fn_ptr_type (), which creates it depending on if atexit or __cxa_atexit will be used as either void(*)(void) or void(*)(void *), but when using atexit and __cxa_thread_atexit it uses the wrong function type for __cxa_thread_atexit. The following patch adds a target hook to add the thiscall attribute to the function pointers, and splits the get_atexit_fn_ptr_type () function into get_atexit_fn_ptr_type () and get_cxa_atexit_fn_ptr_type (), the former always creates shared void(*)(void) type, the latter creates either void(*)(void*) (on most targets) or void(__attribute__((thiscall))*)(void*) (on mingw ia32). So that we don't waiste another GTY global tree for it, because cleanup_type used for the same purpose for __cxa_throw should be the same, the code changes it to use that type too. In register_dtor_fn then based on the decision whether to use atexit, __cxa_atexit or __cxa_thread_atexit it picks the right function pointer type, and also if it decides to emit a __tcf_* wrapper for the cleanup, uses that type for that wrapper so that it agrees on calling convention. 2024-05-10 Jakub Jelinek <ja...@redhat.com> PR target/114968 gcc/ * target.def (use_atexit_for_cxa_atexit): Remove spurious space from comment. (adjust_cdtor_callabi_fntype): New cxx target hook. * targhooks.h (default_cxx_adjust_cdtor_callabi_fntype): Declare. * targhooks.cc (default_cxx_adjust_cdtor_callabi_fntype): New function. * doc/tm.texi.in (TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Add. * doc/tm.texi: Regenerate. * config/i386/i386.cc (ix86_cxx_adjust_cdtor_callabi_fntype): New function. (TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Redefine. gcc/cp/ * cp-tree.h (atexit_fn_ptr_type_node, cleanup_type): Adjust macro comments. (get_cxa_atexit_fn_ptr_type): Declare. * decl.cc (get_atexit_fn_ptr_type): Adjust function comment, only build type for atexit argument. (get_cxa_atexit_fn_ptr_type): New function. (get_atexit_node): Call get_cxa_atexit_fn_ptr_type rather than get_atexit_fn_ptr_type when using __cxa_atexit. (get_thread_atexit_node): Call get_cxa_atexit_fn_ptr_type rather than get_atexit_fn_ptr_type. (start_cleanup_fn): Add ob_parm argument, call get_cxa_atexit_fn_ptr_type or get_atexit_fn_ptr_type depending on it and create PARM_DECL also based on that argument. (register_dtor_fn): Adjust start_cleanup_fn caller, use get_cxa_atexit_fn_ptr_type rather than get_atexit_fn_ptr_type for use_dtor casts. * except.cc (build_throw): Use get_cxa_atexit_fn_ptr_type (). (cherry picked from commit e5d8fd9ce05611093191d500ebc39f150d0ece2b)
