return 0就是正常结束，非零的其他值表示出现错误。
跟大小没有什么关系呀！楼主这么纠结？！
跟大小没有什么关系呀！楼主这么纠结？！
其实我很想知道系统对函数调用一些知识。
这个问题可以延伸一下
2012-04-11 14:30
2012-04-11 18:22
2012-04-11 18:33
2012-04-11 18:39
2012-04-11 18:40
2012-04-11 20:45
2012-04-11 20:53
2012-04-11 21:00
程序代码：
/***
*crt0.c - C runtime initialization routine
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
*Purpose:
* This is the actual startup routine for apps. It calls the user's main
* routine [w]main() or [w]WinMain after performing C Run-Time Library
* initialization.
*
* With ifdefs, this source file also provides the source code for:
* wcrt0.c the startup routine for console apps with wide chars
* wincrt0.c the startup routine for Windows apps
* wwincrt0.c the startup routine for Windows apps with wide chars
*
*******************************************************************************/
#ifndef CRTDLL
#include <cruntime.h>
#include <dos.h>
#include <internal.h>
#include <process.h>
#include <stdlib.h>
#include <string.h>
#include <rterr.h>
#include <rtcapi.h>
#include <windows.h>
#include <awint.h>
#include <tchar.h>
#include <dbgint.h>
#include <locale.h>
#include <sect_attribs.h>
#if defined (_WIN64) && defined (_M_IA64)
#pragma section(".base", long, read)
__declspec(allocate(".base"))
extern
IMAGE_DOS_HEADER __ImageBase;
#else /* defined (_WIN64) && defined (_M_IA64) */
extern
IMAGE_DOS_HEADER __ImageBase;
#endif /* defined (_WIN64) && defined (_M_IA64) */
/*
* This has been moved from unhandld.cpp to here because, we only
* want to set the UnhandledExceptionFilter when this crt is loaded
* by an EXE (ie. not loaded by a DLL)
*/
int __cdecl __CxxSetUnhandledExceptionFilter(void);
_CRTALLOC(".CRT$XIY") static _PIFV pinit = &__CxxSetUnhandledExceptionFilter;
#ifdef WPRFLAG
_TUCHAR * __cdecl _wwincmdln(void);
#else /* WPRFLAG */
_TUCHAR * __cdecl _wincmdln(void);
#endif /* WPRFLAG */
/*
* command line, environment, and a few other globals
*/
#ifdef WPRFLAG
wchar_t *_wcmdln; /* points to wide command line */
#else /* WPRFLAG */
char *_acmdln; /* points to command line */
#endif /* WPRFLAG */
char *_aenvptr = NULL; /* points to environment block */
wchar_t *_wenvptr = NULL; /* points to wide environment block */
static void __cdecl fast_error_exit(int); /* Error exit via ExitProcess */
static int __cdecl check_managed_app(void); /* Determine if a managed app */
/*
* _error_mode and _apptype, together, determine how error messages are
* written out.
*/
int __error_mode = _OUT_TO_DEFAULT;
#ifdef _WINMAIN_
int __app_type = _GUI_APP;
#else /* _WINMAIN_ */
int __app_type = _CONSOLE_APP;
#endif /* _WINMAIN_ */
/***
*mainCRTStartup(void)
*wmainCRTStartup(void)
*WinMainCRTStartup(void)
*wWinMainCRTStartup(void)
*
*Purpose:
* These routines do the C runtime initialization, call the appropriate
* user entry function, and handle termination cleanup. For a managed
* app, they then return the exit code back to the calling routine, which
* is the managed startup code. For an unmanaged app, they call exit and
* never return.
*
* Function: User entry called:
* mainCRTStartup main
* wmainCRTStartup wmain
* WinMainCRTStartup WinMain
* wWinMainCRTStartup wWinMain
*
*Entry:
*
*Exit:
* Managed app: return value from main() et al, or the exception code if
* execution was terminated by the __except guarding the call
* to main().
* Unmanaged app: never return.
*
*******************************************************************************/
#ifdef _WINMAIN_
#ifdef WPRFLAG
#define _tmainCRTStartup wWinMainCRTStartup
#else /* WPRFLAG */
#define _tmainCRTStartup WinMainCRTStartup
#endif /* WPRFLAG */
#else /* _WINMAIN_ */
#ifdef WPRFLAG
#define _tmainCRTStartup wmainCRTStartup
#else /* WPRFLAG */
#define _tmainCRTStartup mainCRTStartup
#endif /* WPRFLAG */
#endif /* _WINMAIN_ */
#ifdef WPRFLAG
#define _twincmdln _wwincmdln
#define _tinitenv __winitenv
#define _targv __wargv
#define _tcmdln _wcmdln
#define _tenvptr _wenvptr
#define _tsetargv _wsetargv
#define _tsetenvp _wsetenvp
#define GetCommandLineT __crtGetCommandLineW
#define GetEnvironmentStringsT __crtGetEnvironmentStringsW
#else /* WPRFLAG */
#define _twincmdln _wincmdln
#define _tinitenv __initenv
#define _targv __argv
#define _tcmdln _acmdln
#define _tenvptr _aenvptr
#define _tsetargv _setargv
#define _tsetenvp _setenvp
#define GetCommandLineT GetCommandLineA
#define GetEnvironmentStringsT __crtGetEnvironmentStringsA
#endif /* WPRFLAG */
static
int
__tmainCRTStartup(
void
);
int
_tmainCRTStartup(
void
)
{
/*
* The /GS security cookie must be initialized before any exception
* handling targetting the current image is registered. No function
* using exception handling can be called in the current image until
* after __security_init_cookie has been called.
*/
__security_init_cookie();
return __tmainCRTStartup();
}
__declspec(noinline)
int
__tmainCRTStartup(
void
)
{
int initret;
int mainret=0;
int managedapp;
#ifdef _WINMAIN_
_TUCHAR *lpszCommandLine;
STARTUPINFO StartupInfo;
__try {
/*
Note: MSDN specifically notes that GetStartupInfo returns no error, and throws unspecified SEH if it fails, so
the very general exception handler below is appropriate
*/
GetStartupInfo( &StartupInfo );
} __except(EXCEPTION_EXECUTE_HANDLER) {
return 255;
}
#endif /* _WINMAIN_ */
/*
* Determine if this is a managed application
*/
managedapp = check_managed_app();
if ( !_heap_init(1) ) /* initialize heap */
fast_error_exit(_RT_HEAPINIT); /* write message and die */
if( !_mtinit() ) /* initialize multi-thread */
fast_error_exit(_RT_THREAD); /* write message and die */
/* Enable buffer count checking if linking against static lib */
_CrtSetCheckCount(TRUE);
/*
* Initialize the Runtime Checks stuff
*/
#ifdef _RTC
_RTC_Initialize();
#endif /* _RTC */
/*
* Guard the remainder of the initialization code and the call
* to user's main, or WinMain, function in a __try/__except
* statement.
*/
__try {
if ( _ioinit() < 0 ) /* initialize lowio */
_amsg_exit(_RT_LOWIOINIT);
/* get wide cmd line info */
_tcmdln = (_TSCHAR *)GetCommandLineT();
/* get wide environ info */
_tenvptr = (_TSCHAR *)GetEnvironmentStringsT();
if ( _tsetargv() < 0 )
_amsg_exit(_RT_SPACEARG);
if ( _tsetenvp() < 0 )
_amsg_exit(_RT_SPACEENV);
initret = _cinit(TRUE); /* do C data initialize */
if (initret != 0)
_amsg_exit(initret);
#ifdef _WINMAIN_
lpszCommandLine = _twincmdln();
mainret = _tWinMain( (HINSTANCE)&__ImageBase,
NULL,
lpszCommandLine,
StartupInfo.dwFlags & STARTF_USESHOWWINDOW
? StartupInfo.wShowWindow
: SW_SHOWDEFAULT
);
#else /* _WINMAIN_ */
_tinitenv = _tenviron;
mainret = _tmain(__argc, _targv, _tenviron);
#endif /* _WINMAIN_ */
if ( !managedapp )
exit(mainret);
_cexit();
}
__except ( _XcptFilter(GetExceptionCode(), GetExceptionInformation()) )
{
/*
* Should never reach here
*/
mainret = GetExceptionCode();
if ( !managedapp )
_exit(mainret);
_c_exit();
} /* end of try - except */
return mainret;
}
/***
*fast_error_exit(rterrnum) - Faster exit fatal errors
*
*Purpose:
* Exit the process with error code of 255 and appropriate error
* message.
*
*Entry:
* int rterrnum - error message number (amsg_exit only).
*
*Exit:
* Calls ExitProcess (through __crtExitProcess).
*
*Exceptions:
*
*******************************************************************************/
static void __cdecl fast_error_exit (
int rterrnum
)
{
/*
* Note that here there is no other option other then to use __error_mode
* as even if we use _set_error_mode, there is very slim possiblity if
* proper _ser_error_mode forwarding is really working.
*/
#ifdef _WINMAIN_
if ( __error_mode == _OUT_TO_STDERR )
#else /* _WINMAIN_ */
if ( __error_mode != _OUT_TO_MSGBOX )
#endif /* _WINMAIN_ */
_FF_MSGBANNER(); /* write run-time error banner */
_NMSG_WRITE(rterrnum); /* write message */
__crtExitProcess(255); /* normally _exit(255) */
}
/***
*check_managed_app() - Check for a managed executable
*
*Purpose:
* Determine if the EXE the startup code is linked into is a managed app
* by looking for the COM Runtime Descriptor in the Image Data Directory
* of the PE or PE+ header.
*
*Entry:
* None
*
*Exit:
* 1 if managed app, 0 if not.
*
*Exceptions:
*
*******************************************************************************/
static int __cdecl check_managed_app (
void
)
{
PIMAGE_DOS_HEADER pDOSHeader;
PIMAGE_NT_HEADERS pPEHeader;
pDOSHeader = &__ImageBase;
if ( pDOSHeader == NULL || pDOSHeader->e_magic != IMAGE_DOS_SIGNATURE )
return 0;
pPEHeader = (PIMAGE_NT_HEADERS)((char *)pDOSHeader +
pDOSHeader->e_lfanew);
if ( pPEHeader->Signature != IMAGE_NT_SIGNATURE )
return 0;
if (pPEHeader->OptionalHeader.Magic != IMAGE_NT_OPTIONAL_HDR_MAGIC)
return 0;
/* prefast assumes we are overflowing __ImageBase */
#pragma warning(push)
#pragma warning(disable:26000)
if (pPEHeader->OptionalHeader.NumberOfRvaAndSizes <= IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR)
return 0;
#pragma warning(push)
return pPEHeader->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_COM_DESCRIPTOR].VirtualAddress != 0;
}
#ifndef WPRFLAG
#endif /* WPRFLAG */
#endif /* CRTDLL */
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2012-04-11 21:15