newlib/winsup/mingw/crt1.c

261 lines
6.6 KiB
C

/*
* crt1.c
* This file has no copyright assigned and is placed in the Public Domain.
* This file is a part of the mingw-runtime package.
* No warranty is given; refer to the file DISCLAIMER within the package.
*
* Source code for the startup proceedures used by all programs. This code
* is compiled to make crt1.o, which should be located in the library path.
*
*/
/* Hide the declaration of _fmode with dllimport attribute in stdlib.h to
avoid problems with older GCC. */
#define __IN_MINGW_RUNTIME
#include <stdlib.h>
#include <stdio.h>
#include <io.h>
#include <process.h>
#include <float.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <signal.h>
/* NOTE: The code for initializing the _argv, _argc, and environ variables
* has been moved to a separate .c file which is included in both
* crt1.c and dllcrt1.c. This means changes in the code don't have to
* be manually synchronized, but it does lead to this not-generally-
* a-good-idea use of include. */
#include "init.c"
extern void _pei386_runtime_relocator (void);
extern int main (int, char **, char **);
/*
* Must have the correct app type for MSVCRT.
*/
#ifdef __MSVCRT__
#define __UNKNOWN_APP 0
#define __CONSOLE_APP 1
#define __GUI_APP 2
__MINGW_IMPORT void __set_app_type(int);
#endif /* __MSVCRT__ */
/* Global _fmode for this .exe, not the one in msvcrt.dll,
The default is set in txtmode.o in libmingw32.a */
/* Override the dllimport'd declarations in stdlib.h */
#undef _fmode
extern int _fmode;
#ifdef __MSVCRT__
extern int* __p__fmode(void); /* To access the dll _fmode */
#endif
/*
* Setup the default file handles to have the _CRT_fmode mode, as well as
* any new files created by the user.
*/
extern int _CRT_fmode;
static void
_mingw32_init_fmode (void)
{
/* Don't set the std file mode if the user hasn't set any value for it. */
if (_CRT_fmode)
{
_fmode = _CRT_fmode;
/*
* This overrides the default file mode settings for stdin,
* stdout and stderr. At first I thought you would have to
* test with isatty, but it seems that the DOS console at
* least is smart enough to handle _O_BINARY stdout and
* still display correctly.
*/
if (stdin)
{
_setmode (_fileno (stdin), _CRT_fmode);
}
if (stdout)
{
_setmode (_fileno (stdout), _CRT_fmode);
}
if (stderr)
{
_setmode (_fileno (stderr), _CRT_fmode);
}
}
/* Now sync the dll _fmode to the one for this .exe. */
#ifdef __MSVCRT__
*__p__fmode() = _fmode;
#else
*_imp___fmode_dll = _fmode;
#endif
}
/* This function will be called when a trap occurs. Thanks to Jacob
Navia for his contribution. */
static CALLBACK long
_gnu_exception_handler (EXCEPTION_POINTERS * exception_data)
{
void (*old_handler) (int);
long action = EXCEPTION_CONTINUE_SEARCH;
int reset_fpu = 0;
switch (exception_data->ExceptionRecord->ExceptionCode)
{
case EXCEPTION_ACCESS_VIOLATION:
/* test if the user has set SIGSEGV */
old_handler = signal (SIGSEGV, SIG_DFL);
if (old_handler == SIG_IGN)
{
/* this is undefined if the signal was raised by anything other
than raise (). */
signal (SIGSEGV, SIG_IGN);
action = EXCEPTION_CONTINUE_EXECUTION;
}
else if (old_handler != SIG_DFL)
{
/* This means 'old' is a user defined function. Call it */
(*old_handler) (SIGSEGV);
action = EXCEPTION_CONTINUE_EXECUTION;
}
break;
case EXCEPTION_FLT_INVALID_OPERATION:
case EXCEPTION_FLT_DIVIDE_BY_ZERO:
case EXCEPTION_FLT_DENORMAL_OPERAND:
case EXCEPTION_FLT_OVERFLOW:
case EXCEPTION_FLT_UNDERFLOW:
case EXCEPTION_FLT_INEXACT_RESULT:
reset_fpu = 1;
/* fall through. */
case EXCEPTION_INT_DIVIDE_BY_ZERO:
/* test if the user has set SIGFPE */
old_handler = signal (SIGFPE, SIG_DFL);
if (old_handler == SIG_IGN)
{
signal (SIGFPE, SIG_IGN);
if (reset_fpu)
_fpreset ();
action = EXCEPTION_CONTINUE_EXECUTION;
}
else if (old_handler != SIG_DFL)
{
/* This means 'old' is a user defined function. Call it */
(*old_handler) (SIGFPE);
action = EXCEPTION_CONTINUE_EXECUTION;
}
break;
default:
break;
}
return action;
}
/*
* The function mainCRTStartup is the entry point for all console programs.
*/
static void __attribute__((noreturn))
__mingw_CRTStartup (void)
{
int nRet;
/*
* Set up the top-level exception handler so that signal handling
* works as expected. The mapping between ANSI/POSIX signals and
* Win32 SE is not 1-to-1, so caveat emptore.
*
*/
SetUnhandledExceptionFilter (_gnu_exception_handler);
/*
* Initialize floating point unit.
*/
_fpreset (); /* Supplied by the runtime library. */
/*
* Set up __argc, __argv and _environ.
*/
_mingw32_init_mainargs ();
/*
* Sets the default file mode.
* If _CRT_fmode is set, also set mode for stdin, stdout
* and stderr, as well
* NOTE: DLLs don't do this because that would be rude!
*/
_mingw32_init_fmode ();
/* Adust references to dllimported data that have non-zero offsets. */
_pei386_runtime_relocator ();
/* Align the stack to 16 bytes for the sake of SSE ops in main
or in functions inlined into main. */
asm __volatile__ ("andl $-16, %%esp" : : : "%esp");
/*
* Call the main function. If the user does not supply one
* the one in the 'libmingw32.a' library will be linked in, and
* that one calls WinMain. See main.c in the 'lib' dir
* for more details.
*/
nRet = main (_argc, _argv, environ);
/*
* Perform exit processing for the C library. This means
* flushing output and calling 'atexit' registered functions.
*/
_cexit ();
ExitProcess (nRet);
}
/*
* The function mainCRTStartup is the entry point for all console programs.
*/
void
mainCRTStartup (void)
{
#ifdef __MSVCRT__
__set_app_type (__CONSOLE_APP);
#endif
__mingw_CRTStartup ();
}
/*
* For now the GUI startup function is the same as the console one.
* This simply gets rid of the annoying warning about not being able
* to find WinMainCRTStartup when linking GUI applications.
*/
void
WinMainCRTStartup (void)
{
#ifdef __MSVCRT__
__set_app_type (__GUI_APP);
#endif
__mingw_CRTStartup ();
}
/*
* We force use of library version of atexit, which is only
* visible in import lib as _imp__atexit
*/
extern int (*_imp__atexit)(void (*)(void));
int atexit (void (* pfn )(void) )
{
return ( (*_imp__atexit)(pfn));
}
/* Likewise for non-ANSI _onexit */
extern _onexit_t (*_imp___onexit)(_onexit_t);
_onexit_t
_onexit (_onexit_t pfn )
{
return (*_imp___onexit)(pfn);
}