@matheusbsbs / matheus-bagliano / commits / 396ff7547d

mingw: replace mingw_startup() hack

Git for Windows has special code to retrieve the command-line parameters (and even the environment) in UTF-16 encoding, so that they can be converted to UTF-8. This is necessary because Git for Windows wants to use UTF-8 encoded strings throughout its code, and the main() function does not get the parameters in that encoding. To do that, we used the __wgetmainargs() function, which is not even a Win32 API function, but provided by the MINGW "runtime" instead. Obviously, this method would not work with any compiler other than GCC, and in preparation for compiling with Visual C++, we would like to avoid precisely that. Lucky us, there is a much more elegant way: we can simply implement the UTF-16 variant of `main()`: `wmain()`. To make that work, we need to link with -municode. The command-line parameters are passed to `wmain()` encoded in UTF-16, as desired, and this method also works with GCC, and also with Visual C++ after adjusting the MSVC linker flags to force it to use `wmain()`. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Jun 19, 2019 at 14:05 UTC 396ff7547d8b3f6a933069f048d09380d515a10b

3 files changed +47 -31

compat/mingw.c

+34 -19

@@ -2301,18 +2301,13 @@ static void setup_windows_environment(void)

2301 setenv("TERM", "cygwin", 1);

2302 }

2303

2304 +#if !defined(_MSC_VER)

2305 /*

2306 * Disable MSVCRT command line wildcard expansion (__getmainargs called from

2307 * mingw startup code, see init.c in mingw runtime).

2308 */

2309 int _CRT_glob = 0;

2309 -

2310 -typedef struct {

2311 - int newmode;

2312 -} _startupinfo;

2313 -

2314 -extern int __wgetmainargs(int *argc, wchar_t ***argv, wchar_t ***env, int glob,

2315 - _startupinfo *si);

2310 +#endif

2311

2312 static NORETURN void die_startup(void)

2313 {

@@ -2390,22 +2385,25 @@ static void maybe_redirect_std_handles(void)

2385 GENERIC_WRITE, FILE_FLAG_NO_BUFFERING);

2386 }

2387

2393 -void mingw_startup(void)

2388 +/*

2389 + * We implement wmain() and compile with -municode, which would

2390 + * normally ignore main(), but we call the latter from the former

2391 + * so that we can handle non-ASCII command-line parameters

2392 + * appropriately.

2393 + *

2394 + * To be more compatible with the core git code, we convert

2395 + * argv into UTF8 and pass them directly to main().

2396 + */

2397 +int wmain(int argc, const wchar_t **wargv)

2398 {

2395 - int i, maxlen, argc;

2396 - char *buffer;

2397 - wchar_t **wenv, **wargv;

2398 - _startupinfo si;

2399 + int i, maxlen, exit_status;

2400 + char *buffer, **save;

2401 + const char **argv;

2402

2403 trace2_initialize_clock();

2404

2405 maybe_redirect_std_handles();

2406

2404 - /* get wide char arguments and environment */

2405 - si.newmode = 0;

2406 - if (__wgetmainargs(&argc, &wargv, &wenv, _CRT_glob, &si) < 0)

2407 - die_startup();

2408 -

2407 /* determine size of argv and environ conversion buffer */

2408 maxlen = wcslen(wargv[0]);

2409 for (i = 1; i < argc; i++)

@@ -2415,9 +2413,16 @@ void mingw_startup(void)

2413 maxlen = 3 * maxlen + 1;

2414 buffer = malloc_startup(maxlen);

2415

2418 - /* convert command line arguments and environment to UTF-8 */

2416 + /*

2417 + * Create a UTF-8 version of w_argv. Also create a "save" copy

2418 + * to remember all the string pointers because parse_options()

2419 + * will remove claimed items from the argv that we pass down.

2420 + */

2421 + ALLOC_ARRAY(argv, argc + 1);

2422 + ALLOC_ARRAY(save, argc + 1);

2423 for (i = 0; i < argc; i++)

2420 - __argv[i] = wcstoutfdup_startup(buffer, wargv[i], maxlen);

2424 + argv[i] = save[i] = wcstoutfdup_startup(buffer, wargv[i], maxlen);

2425 + argv[i] = save[i] = NULL;

2426 free(buffer);

2427

2428 /* fix Windows specific environment settings */

@@ -2436,6 +2441,16 @@ void mingw_startup(void)

2441

2442 /* initialize Unicode console */

2443 winansi_init();

2444 +

2445 + /* invoke the real main() using our utf8 version of argv. */

2446 + exit_status = main(argc, argv);

2447 +

2448 + for (i = 0; i < argc; i++)

2449 + free(save[i]);

2450 + free(save);

2451 + free(argv);

2452 +

2453 + return exit_status;

2454 }

2455

2456 int uname(struct utsname *buf)

compat/mingw.h

+11 -11

@@ -562,18 +562,18 @@ int xwcstoutf(char *utf, const wchar_t *wcs, size_t utflen);

562 extern CRITICAL_SECTION pinfo_cs;

563

564 /*

565 - * A replacement of main() that adds win32 specific initialization.

565 + * Git, like most portable C applications, implements a main() function. On

566 + * Windows, this main() function would receive parameters encoded in the

567 + * current locale, but Git for Windows would prefer UTF-8 encoded parameters.

568 + *

569 + * To make that happen, we still declare main() here, and then declare and

570 + * implement wmain() (which is the Unicode variant of main()) and compile with

571 + * -municode. This wmain() function reencodes the parameters from UTF-16 to

572 + * UTF-8 format, sets up a couple of other things as required on Windows, and

573 + * then hands off to the main() function.

574 */

567 -

568 -void mingw_startup(void);

569 -#define main(c,v) dummy_decl_mingw_main(void); \

570 -static int mingw_main(c,v); \

571 -int main(int argc, const char **argv) \

572 -{ \

573 - mingw_startup(); \

574 - return mingw_main(__argc, (void *)__argv); \

575 -} \

576 -static int mingw_main(c,v)

575 +int wmain(int argc, const wchar_t **w_argv);

576 +int main(int argc, const char **argv);

577

578 /*

579 * Used by Pthread API implementation for Windows

config.mak.uname

+2 -1

@@ -401,7 +401,7 @@ ifeq ($(uname_S),Windows)

401 compat/win32/trace2_win32_process_info.o \

402 compat/win32/dirent.o

403 COMPAT_CFLAGS = -D__USE_MINGW_ACCESS -DNOGDI -DHAVE_STRING_H -Icompat -Icompat/regex -Icompat/win32 -DSTRIP_EXTENSION=\".exe\"

404 - BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -SUBSYSTEM:CONSOLE

404 + BASIC_LDFLAGS = -IGNORE:4217 -IGNORE:4049 -NOLOGO -ENTRY:wmainCRTStartup -SUBSYSTEM:CONSOLE

405 EXTLIBS = user32.lib advapi32.lib shell32.lib wininet.lib ws2_32.lib invalidcontinue.obj

406 PTHREAD_LIBS =

407 lib =

@@ -548,6 +548,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))

548 ETAGS_TARGET = ETAGS

549 NO_POSIX_GOODIES = UnfortunatelyYes

550 DEFAULT_HELP_FORMAT = html

551 + BASIC_LDFLAGS += -municode

552 COMPAT_CFLAGS += -DNOGDI -Icompat -Icompat/win32

553 COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"

554 COMPAT_OBJS += compat/mingw.o compat/winansi.o \