最近在调试几个问题时，发现跟abort函数有关，以前只是简单使用，现在却发现不简单，就多留意了下。
简介
abort中止当前进程并返回错误代码。异常终止一个进程。中止当前进程，返回一个错误代码。错误代码的缺省值是3。
代码
/***
*abort.c - abort a program by raising SIGABRT
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines abort() - print a message and raise SIGABRT.
*
*******************************************************************************/
#include <cruntime.h>
#include <stdlib.h>
#include <internal.h>
#include <awint.h>
#include <rterr.h>
#include <signal.h>
#include <oscalls.h>
#include <mtdll.h>
#include <dbgint.h>
#ifdef _DEBUG
#define _INIT_ABORT_BEHAVIOR _WRITE_ABORT_MSG
#else /* _DEBUG */
#define _INIT_ABORT_BEHAVIOR _CALL_REPORTFAULT
#endif /* _DEBUG */
unsigned int __abort_behavior = _INIT_ABORT_BEHAVIOR;
/***
*void abort() - abort the current program by raising SIGABRT
*
*Purpose:
* print out an abort message and raise the SIGABRT signal. If the user
* hasn't defined an abort handler routine, terminate the program
* with exit status of 3 without cleaning up.
*
* Multi-thread version does not raise SIGABRT -- this isn't supported
* under multi-thread.
*
*Entry:
* None.
*
*Exit:
* Does not return.
*
*Uses:
*
*Exceptions:
*
*******************************************************************************/
void __cdecl abort (
void
)
{
_PHNDLR sigabrt_act = SIG_DFL;
#ifdef _DEBUG
if (__abort_behavior & _WRITE_ABORT_MSG)
{
/* write the abort message */
_NMSG_WRITE(_RT_ABORT);
}
#endif /* _DEBUG */
/* Check if the user installed a handler for SIGABRT.
* We need to read the user handler atomically in the case
* another thread is aborting while we change the signal
* handler.
*/
sigabrt_act = __get_sigabrt();
if (sigabrt_act != SIG_DFL)
{
raise(SIGABRT);
}
/* If there is no user handler for SIGABRT or if the user
* handler returns, then exit from the program anyway
*/
if (__abort_behavior & _CALL_REPORTFAULT)
{
#if defined (_M_ARM) || defined (_CRT_APP)
__fastfail(FAST_FAIL_FATAL_APP_EXIT);
#else /* defined (_M_ARM) || defined (_CRT_APP) */
if (IsProcessorFeaturePresent(PF_FASTFAIL_AVAILABLE))
__fastfail(FAST_FAIL_FATAL_APP_EXIT);
_call_reportfault(_CRT_DEBUGGER_ABORT, STATUS_FATAL_APP_EXIT, EXCEPTION_NONCONTINUABLE);
#endif /* defined (_M_ARM) || defined (_CRT_APP) */
}
/* If we don't want to call ReportFault, then we call _exit(3), which is the
* same as invoking the default handler for SIGABRT
*/
_exit(3);
}
/***
*unsigned int _set_abort_behavior(unsigned int, unsigned int) - set the behavior on abort
*
*Purpose:
*
*Entry:
* unsigned int flags - the flags we want to set
* unsigned int mask - mask the flag values
*
*Exit:
* Return the old behavior flags
*
*Exceptions:
* None
*
*******************************************************************************/
unsigned int __cdecl _set_abort_behavior(unsigned int flags, unsigned int mask)
{
unsigned int oldflags = __abort_behavior;
__abort_behavior = oldflags & (~mask) | flags & mask;
return oldflags;
}
流程
从上面代码，我可以看到，abort的流程如下：
如果是调试版，且__abort_behavior为_WRITE_ABORT_MSG，则调用_NMSG_WRITE(_RT_ABORT);弹出crt异常提示框
点"中止"进程直接退出，点"忽略"后，就判断sigabrt_act的值，不等于SIG_DFL的话调用raise发送信号SIGABRT，然后调用_exit(3)退出
release版则会检测本机支不支持PF_FASTFAIL_AVAILABLE，支持就走windows快速失败机制，不支持就执行 _call_reportfault(_CRT_DEBUGGER_ABORT, STATUS_FATAL_APP_EXIT, EXCEPTION_NONCONTINUABLE);然后退出。
隐藏的秘密
上面讲的那些我相信大家都了解，但是，其实这个函数里，可能会引发多个异常。
调用_NMSG_WRITE(_RT_ABORT)，会引发异常0x4001000A或0x40010006：
调用__fastfail(FAST_FAIL_FATAL_APP_EXIT);会引发异常0xc0000409子代码为FAST_FAIL_FATAL_APP_EXIT：
而调用_call_reportfault会引发异常STATUS_FATAL_APP_EXIT(0x40000015)：
#if (defined (_M_IX86) || defined (_M_X64)) && !defined (_CRT_APP)
void __cdecl _call_reportfault(
int nDbgHookCode,
DWORD dwExceptionCode,
DWORD dwExceptionFlags
)
{
// Notify the debugger if attached.
if (nDbgHookCode != _CRT_DEBUGGER_IGNORE)
_CRT_DEBUGGER_HOOK(nDbgHookCode);
/* Fake an exception to call reportfault. */
EXCEPTION_RECORD ExceptionRecord = {0};
CONTEXT ContextRecord;
EXCEPTION_POINTERS ExceptionPointers = {&ExceptionRecord, &ContextRecord};
BOOL wasDebuggerPresent = FALSE;
DWORD ret = 0;
#if defined (_M_IX86)
__asm {
mov dword ptr [ContextRecord.Eax], eax
mov dword ptr [ContextRecord.Ecx], ecx
mov dword ptr [ContextRecord.Edx], edx
mov dword ptr [ContextRecord.Ebx], ebx
mov dword ptr [ContextRecord.Esi], esi
mov dword ptr [ContextRecord.Edi], edi
mov word ptr [ContextRecord.SegSs], ss
mov word ptr [ContextRecord.SegCs], cs
mov word ptr [ContextRecord.SegDs], ds
mov word ptr [ContextRecord.SegEs], es
mov word ptr [ContextRecord.SegFs], fs
mov word ptr [ContextRecord.SegGs], gs
pushfd
pop [ContextRecord.EFlags]
}
ContextRecord.ContextFlags = CONTEXT_CONTROL;
#pragma warning(push)
#pragma warning(disable:4311)
ContextRecord.Eip = (ULONG)_ReturnAddress();
ContextRecord.Esp = (ULONG)_AddressOfReturnAddress();
#pragma warning(pop)
ContextRecord.Ebp = *((ULONG *)_AddressOfReturnAddress()-1);
#elif defined (_M_X64)
__crtCaptureCurrentContext(&ContextRecord);
ContextRecord.Rip = (ULONGLONG) _ReturnAddress();
ContextRecord.Rsp = (ULONGLONG) _AddressOfReturnAddress()+8;
#endif /* defined (_M_X64) */
ExceptionRecord.ExceptionCode = dwExceptionCode;
ExceptionRecord.ExceptionFlags = dwExceptionFlags;
ExceptionRecord.ExceptionAddress = _ReturnAddress();
wasDebuggerPresent = IsDebuggerPresent();
/* Raises an exception that bypasses all exception handlers. */
ret = __crtUnhandledException(&ExceptionPointers);
// if no handler found and no debugger previously attached
// the execution must stop into the debugger hook.
if (ret == EXCEPTION_CONTINUE_SEARCH && !wasDebuggerPresent && nDbgHookCode != _CRT_DEBUGGER_IGNORE) {
_CRT_DEBUGGER_HOOK(nDbgHookCode);
}
}
来源：https://www.cnblogs.com/yilang/p/12036034.html