reactos/lib/3rdparty/mingw/crt1.c

   1 /*
   2  * crt1.c
   3  * This file has no copyright assigned and is placed in the Public Domain.
   4  * This file is a part of the mingw-runtime package.
   5  * No warranty is given; refer to the file DISCLAIMER within the package.
   6  *
   7  * Source code for the startup proceedures used by all programs. This code
   8  * is compiled to make crt1.o, which should be located in the library path.
   9  *
  10  */
  11
  12 /* Hide the declaration of _fmode with dllimport attribute in stdlib.h to
  13    avoid problems with older GCC. */
  14 #define __IN_MINGW_RUNTIME
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <io.h>
  18 #include <process.h>
  19 #include <float.h>
  20 #define WIN32_LEAN_AND_MEAN
  21 #include <windows.h>
  22 #include <signal.h>
  23
  24 /* NOTE: The code for initializing the _argv, _argc, and environ variables
  25  *       has been moved to a separate .c file which is included in both
  26  *       crt1.c and dllcrt1.c. This means changes in the code don't have to
  27  *       be manually synchronized, but it does lead to this not-generally-
  28  *       a-good-idea use of include. */
  29 #include "init.c"
  30 #include "cpu_features.h"
  31
  32 extern void _pei386_runtime_relocator (void);
  33
  34 extern int main (int, char **, char **);
  35
  36 /*
  37  * Must have the correct app type for MSVCRT.
  38  */
  39
  40 #ifdef __MSVCRT__
  41 #define __UNKNOWN_APP    0
  42 #define __CONSOLE_APP    1
  43 #define __GUI_APP        2
  44 __MINGW_IMPORT void __set_app_type(int);
  45 #endif /* __MSVCRT__ */
  46
  47 /*  Global _fmode for this .exe, not the one in msvcrt.dll,
  48     The default is set in txtmode.o in libmingw32.a */
  49 /* Override the dllimport'd declarations in stdlib.h */
  50 #undef _fmode
  51 extern int _fmode;
  52 #ifdef __MSVCRT__
  53 extern int* __p__fmode(void); /* To access the dll _fmode */
  54 #endif
  55
  56 /*
  57  * Setup the default file handles to have the _CRT_fmode mode, as well as
  58  * any new files created by the user.
  59  */
  60 extern int _CRT_fmode;
  61
  62 static void
  63 _mingw32_init_fmode (void)
  64 {
  65   /* Don't set the std file mode if the user hasn't set any value for it. */
  66   if (_CRT_fmode)
  67     {
  68       _fmode = _CRT_fmode;
  69
  70       /*
  71        * This overrides the default file mode settings for stdin,
  72        * stdout and stderr. At first I thought you would have to
  73        * test with isatty, but it seems that the DOS console at
  74        * least is smart enough to handle _O_BINARY stdout and
  75        * still display correctly.
  76        */
  77       if (stdin)
  78         {
  79           _setmode (_fileno (stdin), _CRT_fmode);
  80         }
  81       if (stdout)
  82         {
  83           _setmode (_fileno (stdout), _CRT_fmode);
  84         }
  85       if (stderr)
  86         {
  87           _setmode (_fileno (stderr), _CRT_fmode);
  88         }
  89     }
  90
  91     /*  Now sync  the dll _fmode to the  one for this .exe.  */
  92 #ifdef __MSVCRT__
  93     *__p__fmode() = _fmode;
  94 #else
  95     *_imp___fmode_dll = _fmode;
  96 #endif
  97 }
  98
  99 /* This function will be called when a trap occurs. Thanks to Jacob
 100    Navia for his contribution. */
 101 static LONG CALLBACK
 102 _gnu_exception_handler (EXCEPTION_POINTERS * exception_data)
 103 {
 104   void (*old_handler) (int);
 105   LONG action = EXCEPTION_CONTINUE_SEARCH;
 106   int reset_fpu = 0;
 107
 108   switch (exception_data->ExceptionRecord->ExceptionCode)
 109     {
 110     case EXCEPTION_ACCESS_VIOLATION:
 111       /* test if the user has set SIGSEGV */
 112       old_handler = signal (SIGSEGV, SIG_DFL);
 113       if (old_handler == SIG_IGN)
 114         {
 115           /* this is undefined if the signal was raised by anything other
 116              than raise ().  */
 117           signal (SIGSEGV, SIG_IGN);
 118           action = EXCEPTION_CONTINUE_EXECUTION;
 119         }
 120       else if (old_handler != SIG_DFL)
 121         {
 122           /* This means 'old' is a user defined function. Call it */
 123           (*old_handler) (SIGSEGV);
 124           action = EXCEPTION_CONTINUE_EXECUTION;
 125         }
 126       break;
 127
 128     case EXCEPTION_ILLEGAL_INSTRUCTION:
 129     case EXCEPTION_PRIV_INSTRUCTION:
 130       /* test if the user has set SIGILL */
 131       old_handler = signal (SIGILL, SIG_DFL);
 132       if (old_handler == SIG_IGN)
 133         {
 134           /* this is undefined if the signal was raised by anything other
 135              than raise ().  */
 136           signal (SIGILL, SIG_IGN);
 137           action = EXCEPTION_CONTINUE_EXECUTION;
 138         }
 139       else if (old_handler != SIG_DFL)
 140         {
 141           /* This means 'old' is a user defined function. Call it */
 142           (*old_handler) (SIGILL);
 143           action = EXCEPTION_CONTINUE_EXECUTION;
 144         }
 145       break;
 146
 147     case EXCEPTION_FLT_INVALID_OPERATION:
 148     case EXCEPTION_FLT_DIVIDE_BY_ZERO:
 149     case EXCEPTION_FLT_DENORMAL_OPERAND:
 150     case EXCEPTION_FLT_OVERFLOW:
 151     case EXCEPTION_FLT_UNDERFLOW:
 152     case EXCEPTION_FLT_INEXACT_RESULT:
 153       reset_fpu = 1;
 154       /* fall through. */
 155
 156     case EXCEPTION_INT_DIVIDE_BY_ZERO:
 157       /* test if the user has set SIGFPE */
 158       old_handler = signal (SIGFPE, SIG_DFL);
 159       if (old_handler == SIG_IGN)
 160         {
 161           signal (SIGFPE, SIG_IGN);
 162           if (reset_fpu)
 163             _fpreset ();
 164           action = EXCEPTION_CONTINUE_EXECUTION;
 165         }
 166       else if (old_handler != SIG_DFL)
 167         {
 168           /* This means 'old' is a user defined function. Call it */
 169           (*old_handler) (SIGFPE);
 170           action = EXCEPTION_CONTINUE_EXECUTION;
 171         }
 172       break;
 173
 174     default:
 175       break;
 176     }
 177   return action;
 178 }
 179
 180 /*
 181  * The function mainCRTStartup is the entry point for all console programs.
 182  */
 183 static void  __attribute__((noreturn))
 184 __mingw_CRTStartup (void)
 185 {
 186   int nRet;
 187
 188   /*
 189    * Set up the top-level exception handler so that signal handling
 190    * works as expected. The mapping between ANSI/POSIX signals and
 191    * Win32 SE is not 1-to-1, so caveat emptore.
 192    *
 193    */
 194   SetUnhandledExceptionFilter (_gnu_exception_handler);
 195
 196   /*
 197    * Initialize floating point unit.
 198    */
 199   __cpu_features_init ();       /* Do we have SSE, etc.*/
 200   _fpreset ();                  /* Supplied by the runtime library. */
 201
 202   /*
 203    * Set up __argc, __argv and _environ.
 204    */
 205   _mingw32_init_mainargs ();
 206
 207   /*
 208    * Sets the default file mode.
 209    * If _CRT_fmode is set, also set mode for stdin, stdout
 210    * and stderr, as well
 211    * NOTE: DLLs don't do this because that would be rude!
 212    */
 213   _mingw32_init_fmode ();
 214
 215    /* Adust references to dllimported data that have non-zero offsets.  */
 216   _pei386_runtime_relocator ();
 217
 218   /* Align the stack to 16 bytes for the sake of SSE ops in main
 219      or in functions inlined into main.  */
 220   asm  __volatile__  ("andl $-16, %%esp" : : : "%esp");
 221
 222   /*
 223    * Call the main function. If the user does not supply one
 224    * the one in the 'libmingw32.a' library will be linked in, and
 225    * that one calls WinMain. See main.c in the 'lib' dir
 226    * for more details.
 227    */
 228   nRet = main (_argc, _argv, _environ);
 229
 230   /*
 231    * Perform exit processing for the C library. This means
 232    * flushing output and calling 'atexit' registered functions.
 233    */
 234   _cexit ();
 235
 236   ExitProcess (nRet);
 237 }
 238
 239 /*
 240  * The function mainCRTStartup is the entry point for all console programs.
 241  */
 242 void
 243 mainCRTStartup (void)
 244 {
 245 #ifdef __MSVCRT__
 246   __set_app_type (__CONSOLE_APP);
 247 #endif
 248   __mingw_CRTStartup ();
 249 }
 250
 251 /*
 252  * For now the GUI startup function is the same as the console one.
 253  * This simply gets rid of the annoying warning about not being able
 254  * to find WinMainCRTStartup when linking GUI applications.
 255  */
 256 void
 257 WinMainCRTStartup (void)
 258 {
 259 #ifdef __MSVCRT__
 260   __set_app_type (__GUI_APP);
 261 #endif
 262   __mingw_CRTStartup ();
 263 }
 264
 265 #if 0
 266 /*
 267  *  We force use of library version of atexit, which is only
 268  *  visible in import lib as _imp__atexit
 269  */
 270 extern int (*_imp__atexit)(void (*)(void));
 271 int atexit (void (* pfn )(void) )
 272 {
 273   return ( (*_imp__atexit)(pfn));
 274 }
 275
 276 /* Likewise for non-ANSI _onexit */
 277 extern _onexit_t (*_imp___onexit)(_onexit_t);
 278 _onexit_t
 279 _onexit (_onexit_t pfn )
 280 {
 281   return (*_imp___onexit)(pfn);
 282 }
 283 #endif