common/win_main_utf8.h

   1 #ifndef WIN_MAIN_UTF8_H
   2 #define WIN_MAIN_UTF8_H
   3
   4 /* For Windows systems this provides a way to get UTF-8 encoded argv strings,
   5  * and also overrides fopen to accept UTF-8 filenames. Working with wmain
   6  * directly complicates cross-platform compatibility, while normal main() in
   7  * Windows uses the current codepage (which has limited availability of
   8  * characters).
   9  *
  10  * For MinGW, you must link with -municode
  11  */
  12 #ifdef _WIN32
  13 #define WIN32_LEAN_AND_MEAN
  14 #include <windows.h>
  15 #include <shellapi.h>
  16 #include <wchar.h>
  17
  18 #ifdef __cplusplus
  19 #include <memory>
  20
  21 #define STATIC_CAST(...) static_cast<__VA_ARGS__>
  22 #define REINTERPRET_CAST(...) reinterpret_cast<__VA_ARGS__>
  23 #define MAYBE_UNUSED [[maybe_unused]]
  24
  25 #else
  26
  27 #define STATIC_CAST(...) (__VA_ARGS__)
  28 #define REINTERPRET_CAST(...) (__VA_ARGS__)
  29 #ifdef __GNUC__
  30 #define MAYBE_UNUSED __attribute__((__unused__))
  31 #else
  32 #define MAYBE_UNUSED
  33 #endif
  34 #endif
  35
  36 MAYBE_UNUSED static FILE *my_fopen(const char *fname, const char *mode)
  37 {
  38     wchar_t *wname=NULL, *wmode=NULL;
  39     int namelen, modelen;
  40     FILE *file = NULL;
  41     errno_t err;
  42
  43     namelen = MultiByteToWideChar(CP_UTF8, 0, fname, -1, NULL, 0);
  44     modelen = MultiByteToWideChar(CP_UTF8, 0, mode, -1, NULL, 0);
  45
  46     if(namelen <= 0 || modelen <= 0)
  47     {
  48         fprintf(stderr, "Failed to convert UTF-8 fname \"%s\", mode \"%s\"\n", fname, mode);
  49         return NULL;
  50     }
  51
  52 #ifdef __cplusplus
  53     auto strbuf = std::make_unique<wchar_t[]>(static_cast<size_t>(namelen) +
  54         static_cast<size_t>(modelen));
  55     wname = strbuf.get();
  56 #else
  57     wname = (wchar_t*)calloc(sizeof(wchar_t), (size_t)namelen + (size_t)modelen);
  58 #endif
  59     wmode = wname + namelen;
  60     MultiByteToWideChar(CP_UTF8, 0, fname, -1, wname, namelen);
  61     MultiByteToWideChar(CP_UTF8, 0, mode, -1, wmode, modelen);
  62
  63     err = _wfopen_s(&file, wname, wmode);
  64     if(err)
  65     {
  66         errno = err;
  67         file = NULL;
  68     }
  69
  70 #ifndef __cplusplus
  71     free(wname);
  72 #endif
  73     return file;
  74 }
  75 #define fopen my_fopen
  76
  77
  78 /* SDL overrides main and provides UTF-8 args for us. */
  79 #if !defined(SDL_MAIN_NEEDED) && !defined(SDL_MAIN_AVAILABLE)
  80 int my_main(int, char**);
  81 #define main my_main
  82
  83 #ifdef __cplusplus
  84 extern "C"
  85 #endif
  86 int wmain(int argc, wchar_t **wargv)
  87 {
  88     char **argv;
  89     size_t total;
  90     int i;
  91
  92     total = sizeof(*argv) * STATIC_CAST(size_t)(argc);
  93     for(i = 0;i < argc;i++)
  94         total += STATIC_CAST(size_t)(WideCharToMultiByte(CP_UTF8, 0, wargv[i], -1, NULL, 0, NULL,
  95             NULL));
  96
  97 #ifdef __cplusplus
  98     auto argbuf = std::make_unique<char[]>(total);
  99     argv = reinterpret_cast<char**>(argbuf.get());
 100 #else
 101     argv = (char**)calloc(1, total);
 102 #endif
 103     argv[0] = REINTERPRET_CAST(char*)(argv + argc);
 104     for(i = 0;i < argc-1;i++)
 105     {
 106         int len = WideCharToMultiByte(CP_UTF8, 0, wargv[i], -1, argv[i], 65535, NULL, NULL);
 107         argv[i+1] = argv[i] + len;
 108     }
 109     WideCharToMultiByte(CP_UTF8, 0, wargv[i], -1, argv[i], 65535, NULL, NULL);
 110
 111 #ifdef __cplusplus
 112     return main(argc, argv);
 113 #else
 114     i = main(argc, argv);
 115
 116     free(argv);
 117     return i;
 118 #endif
 119 }
 120 #endif /* !defined(SDL_MAIN_NEEDED) && !defined(SDL_MAIN_AVAILABLE) */
 121
 122 #endif /* _WIN32 */
 123
 124 #endif /* WIN_MAIN_UTF8_H */