[PATCH v14 0/4] MR9265: crt: Run MSVC constructors and destructors
There are several motivations to enable ctor/dtor support: 1. ASan. This is not just about my wine-asan work, this is important for @bernhardu's PE asan work as well. The compiler generates ctors that poisons memory around global variables so misuses of them can be caught. This is the same both of our implementations of ASan. 2. Building third-party codebases against wine's CRT. This is not necessary for mingw-gcc or llvm-mingw, but the MSVC frontend of clang is another option for cross-compiling to Windows. However right now that requires Windows SDK. Bringing wine CRT to the point of being functional enough will give us another option. Could be useful for things like Proton. 3. (Controversial) Many dlls perform init/deinit tasks in `DllMain`. Some of them might benefit from a conversion to ctor/dtor. Since nothing in wine uses ctor/dtor right now, this change shouldn't have any impact by itself. -- v14: crt: Run MSVC constructors and destructors. winecrt0: Add fallback initterm and initterm_e implementations. https://gitlab.winehq.org/wine/wine/-/merge_requests/9265
From: Yuxuan Shui <yshui@codeweavers.com> --- tools/winebuild/build.h | 1 + tools/winebuild/spec16.c | 1 + tools/winebuild/spec32.c | 27 +++++++++++++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/tools/winebuild/build.h b/tools/winebuild/build.h index 3acf987aab2..0cabc4648db 100644 --- a/tools/winebuild/build.h +++ b/tools/winebuild/build.h @@ -301,6 +301,7 @@ extern void output_imports( DLLSPEC *spec ); extern void output_import_lib( DLLSPEC *spec, struct strarray files ); extern void output_static_lib( const char *output_name, struct strarray files, int create ); extern void output_exports( DLLSPEC *spec ); +extern void output_crt_sections(void); extern int load_res32_file( const char *name, DLLSPEC *spec ); extern void output_resources( DLLSPEC *spec ); extern void output_bin_resources( DLLSPEC *spec, unsigned int start_rva ); diff --git a/tools/winebuild/spec16.c b/tools/winebuild/spec16.c index face1c551d9..d16e97eabe6 100644 --- a/tools/winebuild/spec16.c +++ b/tools/winebuild/spec16.c @@ -790,6 +790,7 @@ void output_spec16_file( DLLSPEC *spec16 ) output_stubs( spec16 ); output_exports( spec32 ); output_imports( spec16 ); + output_crt_sections(); if (!strcmp( spec16->dll_name, "kernel" )) output_asm_relays16(); if (needs_get_pc_thunk) output_get_pc_thunk(); if (spec16->main_module) diff --git a/tools/winebuild/spec32.c b/tools/winebuild/spec32.c index 7099e82e0f6..ef280b7f51e 100644 --- a/tools/winebuild/spec32.c +++ b/tools/winebuild/spec32.c @@ -703,6 +703,32 @@ static void output_load_config(void) } +void output_crt_sections(void) +{ + /* Generate the start/end symbols for .CRT$X?? sections. The start symbol is put into + * .CRT$X?A, the end .CRT$X?Z. Since the linker sort .CRT$X?? sections by name, these symbols + * will end up at the right location.*/ + static const char sections[] = "ict"; + int i; + for (i = 0; sections[i]; i++) + { + char *symbol_name = strmake( "__x%c_a", sections[i] ); + output( "\t.section .CRT$X%cA\n", toupper( sections[i] ) ); + output( "\t.globl %s\n", asm_name( symbol_name ) ); + output( "\t.balign %u\n", get_ptr_size() ); + output( "%s:\n", asm_name( symbol_name ) ); + output( "\t%s 0\n", get_asm_ptr_keyword() ); + + symbol_name = strmake( "__x%c_z", sections[i] ); + output( "\t.section .CRT$X%cZ\n", toupper( sections[i] ) ); + output( "\t.globl %s\n", asm_name( symbol_name ) ); + output( "\t.balign %u\n", get_ptr_size() ); + output( "%s:\n", asm_name( symbol_name ) ); + output( "\t%s 0\n", get_asm_ptr_keyword() ); + } +} + + /******************************************************************* * output_module * @@ -841,6 +867,7 @@ void output_spec32_file( DLLSPEC *spec ) output_imports( spec ); if (needs_get_pc_thunk) output_get_pc_thunk(); output_load_config(); + output_crt_sections(); output_resources( spec ); output_gnu_stack_note(); close_output_file(); -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/9265
From: Yuxuan Shui <yshui@codeweavers.com> On mingw targets this is already done by ld's linker script. --- tools/winegcc/winegcc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/winegcc/winegcc.c b/tools/winegcc/winegcc.c index f8651804fa2..f5eb2a81d83 100644 --- a/tools/winegcc/winegcc.c +++ b/tools/winegcc/winegcc.c @@ -628,6 +628,9 @@ static struct strarray get_link_args( const char *output_name ) strarray_add( &link_args, strmake( "-Wl,-filealign:%s,-align:%s,-driver", file_align, section_align )); + /* Merge .CRT sections into .rdata */ + strarray_add( &link_args, "-Wl,-merge:.CRT=.rdata" ); + strarray_addall( &link_args, flags ); return link_args; -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/9265
From: Yuxuan Shui <yshui@codeweavers.com> --- dlls/winecrt0/Makefile.in | 2 ++ dlls/winecrt0/initterm.c | 42 +++++++++++++++++++++++++++++++ dlls/winecrt0/initterm_e.c | 43 ++++++++++++++++++++++++++++++++ include/msvcrt/corecrt_startup.h | 1 + 4 files changed, 88 insertions(+) create mode 100644 dlls/winecrt0/initterm.c create mode 100644 dlls/winecrt0/initterm_e.c diff --git a/dlls/winecrt0/Makefile.in b/dlls/winecrt0/Makefile.in index 29cd88f8637..e594e532929 100644 --- a/dlls/winecrt0/Makefile.in +++ b/dlls/winecrt0/Makefile.in @@ -18,6 +18,8 @@ SOURCES = \ exe_main.c \ exe_wentry.c \ exe_wmain.c \ + initterm.c \ + initterm_e.c \ register.c \ setjmp.c \ stub.c \ diff --git a/dlls/winecrt0/initterm.c b/dlls/winecrt0/initterm.c new file mode 100644 index 00000000000..5fabba2e7db --- /dev/null +++ b/dlls/winecrt0/initterm.c @@ -0,0 +1,42 @@ +/* + * _initterm fallback implementation + * + * Copyright 2025 Yuxuan Shui for CodeWeavers + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +#define _ACRTIMP + +#include <process.h> +#include "minwindef.h" + +#include "wine/asm.h" + +/* This is a fallback version of msvcrt's _initterm. Since _initterm is used in winecrt0, + * if the final object is linked with a version of msvcrt without the _initterm function, this + * version will be used. */ +void CDECL _initterm( _PVFV *start,_PVFV *end ) +{ + _PVFV *current = start; + + while (current < end) + { + if (*current) (**current)(); + current++; + } +} + +__ASM_GLOBAL_IMPORT(_initterm) diff --git a/dlls/winecrt0/initterm_e.c b/dlls/winecrt0/initterm_e.c new file mode 100644 index 00000000000..bb4d3d2ef02 --- /dev/null +++ b/dlls/winecrt0/initterm_e.c @@ -0,0 +1,43 @@ +/* + * _initterm_e fallback implementation + * + * Copyright 2025 Yuxuan Shui for CodeWeavers + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +#define _ACRTIMP + +#include <process.h> +#include "minwindef.h" + +#include "wine/asm.h" + +/* This is a fallback version of msvcrt's _initterm_e. Since _initterm_e is used in winecrt0, + * if the final object is linked with a version of msvcrt without the _initterm_e function, this + * version will be used. */ +int CDECL _initterm_e( _PIFV *table, _PIFV *end ) +{ + int res = 0; + + while (!res && table < end) + { + if (*table) res = (**table)(); + table++; + } + return res; +} + +__ASM_GLOBAL_IMPORT(_initterm_e) diff --git a/include/msvcrt/corecrt_startup.h b/include/msvcrt/corecrt_startup.h index c1c519da618..4094cb16150 100644 --- a/include/msvcrt/corecrt_startup.h +++ b/include/msvcrt/corecrt_startup.h @@ -26,6 +26,7 @@ typedef void (__cdecl *_PVFV)(void); typedef int (__cdecl *_PIFV)(void); typedef void (__cdecl *_PVFI)(int); +_ACRTIMP void __cdecl _initterm(_PVFV *, _PVFV *); _ACRTIMP int __cdecl _initterm_e(_PIFV *, _PIFV *); typedef struct _onexit_table_t { -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/9265
From: Yuxuan Shui <yshui@codeweavers.com> --- dlls/msvcrt/crt_init.h | 64 +++++++++++++++++++++++++++++++++++++ dlls/msvcrt/crt_main.c | 4 +-- dlls/msvcrt/crt_wmain.c | 4 +-- dlls/msvcrt/data.c | 5 +++ dlls/winecrt0/crt_dllmain.c | 21 +++++++++++- 5 files changed, 93 insertions(+), 5 deletions(-) create mode 100644 dlls/msvcrt/crt_init.h diff --git a/dlls/msvcrt/crt_init.h b/dlls/msvcrt/crt_init.h new file mode 100644 index 00000000000..508efb7aaf3 --- /dev/null +++ b/dlls/msvcrt/crt_init.h @@ -0,0 +1,64 @@ +/* + * Copyright 2025 Yuxuan Shui for CodeWeavers + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +#if 0 +#pragma makedep implib +#endif + +#include <process.h> +#include <stdlib.h> +#include "minwindef.h" + +extern _PIFV __xi_a[]; +extern _PIFV __xi_z[]; +extern _PVFV __xc_a[]; +extern _PVFV __xc_z[]; +extern _PVFV __xt_a[]; +extern _PVFV __xt_z[]; + +static inline int INIT_initterm_e(_PIFV *table, _PIFV *end) +{ +#if _MSVCR_VER<80 + int res = 0; + while (!res && table < end) { + if (*table) + res = (**table)(); + table++; + } + return res; +#else + return _initterm_e(table, end); +#endif +} + +static __cdecl void do_global_dtors(void) +{ + _initterm(__xt_a, __xt_z); +} + +static void do_global_ctors(void) +{ + if (INIT_initterm_e(__xi_a, __xi_z) != 0) return; + _initterm(__xc_a, __xc_z); + +#ifdef _UCRT + _crt_atexit(do_global_dtors); +#else + _onexit((_onexit_t)do_global_dtors); +#endif +} diff --git a/dlls/msvcrt/crt_main.c b/dlls/msvcrt/crt_main.c index eb785e30bb0..fe900295cf1 100644 --- a/dlls/msvcrt/crt_main.c +++ b/dlls/msvcrt/crt_main.c @@ -23,12 +23,11 @@ #endif #include <stdarg.h> -#include <stdlib.h> -#include <process.h> #include "windef.h" #include "winbase.h" #include "winternl.h" +#include "crt_init.h" int __cdecl main(int argc, char **argv, char **env); @@ -54,6 +53,7 @@ int __cdecl mainCRTStartup(void) __getmainargs(&argc, &argv, &env, 0, &new_mode); #endif _set_app_type(get_nt_header()->OptionalHeader.Subsystem == IMAGE_SUBSYSTEM_WINDOWS_GUI ? _crt_gui_app : _crt_console_app); + do_global_ctors(); ret = main(argc, argv, env); diff --git a/dlls/msvcrt/crt_wmain.c b/dlls/msvcrt/crt_wmain.c index 79755d1a6e9..c3ea3fffd6f 100644 --- a/dlls/msvcrt/crt_wmain.c +++ b/dlls/msvcrt/crt_wmain.c @@ -23,12 +23,11 @@ #endif #include <stdarg.h> -#include <stdlib.h> -#include <process.h> #include "windef.h" #include "winbase.h" #include "winternl.h" +#include "crt_init.h" int __cdecl wmain(int argc, WCHAR **argv, WCHAR **env); @@ -54,6 +53,7 @@ int __cdecl wmainCRTStartup(void) __wgetmainargs(&argc, &argv, &env, 0, &new_mode); #endif _set_app_type(get_nt_header()->OptionalHeader.Subsystem == IMAGE_SUBSYSTEM_WINDOWS_GUI ? _crt_gui_app : _crt_console_app); + do_global_ctors(); ret = wmain(argc, argv, env); diff --git a/dlls/msvcrt/data.c b/dlls/msvcrt/data.c index 6e764e52eae..5b3d78009e9 100644 --- a/dlls/msvcrt/data.c +++ b/dlls/msvcrt/data.c @@ -22,6 +22,7 @@ #include <math.h> #include "msvcrt.h" #include <winnls.h> +#include "wine/asm.h" #include "wine/debug.h" WINE_DEFAULT_DEBUG_CHANNEL(msvcrt); @@ -557,6 +558,8 @@ void CDECL _initterm(_INITTERMFUN *start,_INITTERMFUN *end) } } +__ASM_GLOBAL_IMPORT(_initterm) + /********************************************************************* * _initterm_e (MSVCRT.@) * @@ -581,6 +584,8 @@ int CDECL _initterm_e(_INITTERM_E_FN *table, _INITTERM_E_FN *end) return res; } +__ASM_GLOBAL_IMPORT(_initterm_e) + /********************************************************************* * __set_app_type (MSVCRT.@) */ diff --git a/dlls/winecrt0/crt_dllmain.c b/dlls/winecrt0/crt_dllmain.c index 181760c884a..08a3336a9cc 100644 --- a/dlls/winecrt0/crt_dllmain.c +++ b/dlls/winecrt0/crt_dllmain.c @@ -22,12 +22,31 @@ #include <stdarg.h> #include <stdio.h> +#include <process.h> #include "windef.h" #include "winbase.h" +extern _PIFV __xi_a[]; +extern _PIFV __xi_z[]; +extern _PVFV __xc_a[]; +extern _PVFV __xc_z[]; +extern _PVFV __xt_a[]; +extern _PVFV __xt_z[]; + BOOL WINAPI DllMainCRTStartup( HINSTANCE inst, DWORD reason, void *reserved ) { - return DllMain( inst, reason, reserved ); + BOOL ret; + + if (reason == DLL_PROCESS_ATTACH) + { + if (_initterm_e( __xi_a, __xi_z ) != 0) return FALSE; + _initterm( __xc_a, __xc_z ); + } + + ret = DllMain( inst, reason, reserved ); + + if (reason == DLL_PROCESS_DETACH) _initterm( __xt_a, __xt_z ); + return ret; } #endif -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/9265
Yeah, if CRT functions were in winecrt0, then they could take precedence over imported ones.
~~as long as the code being linked uses anything from msvcrt, its implib will be pulled in and `winecrt0` will get the version from msvcrt. i think that should cover most of the dlls/exes.~~ -- https://gitlab.winehq.org/wine/wine/-/merge_requests/9265#note_127329
force pushed to fix build failure. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/9265#note_127330
On Mon Jan 19 15:35:26 2026 +0000, Yuxuan Shui wrote:
Yeah, if CRT functions were in winecrt0, then they could take precedence over imported ones. ~~as long as the code being linked uses anything from msvcrt, its implib will be pulled in and `winecrt0` will get the version from msvcrt. i think that should cover most of the dlls/exes.~~ ah, no, foiled by link order again. crt comes _after_ winecrt0 in most linker arguments, so winecrt0 will take precedence.
in that case I'd say `winecrtend` is probably the best solution if you still want to use the initterm from msvcrt when possible. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/9265#note_127331
ntdll already serves as a CRT of last resort. From a CRT perspective, treating initterm like, for example, sprintf and expecting it to always be available seems reasonable to me. That said, it is a bit of a complexity trade-off, so sure, we can avoid that.
Well, `sprintf` is exported from ntdll, but `initterm` isn't. In this case the last resort would be kernelbase. Obviously that wouldn't work for modules that don't import kernelbase, but I don't think it justifies adding a static import lib to ntdll. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/9265#note_127332
participants (3)
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Alexandre Julliard (＠julliard) -
Yuxuan Shui
-
Yuxuan Shui (＠yshui)