unwind.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

#define WIN32_NO_STATUS
#include <precomp.h>
#include <windows.h>
#define NTOS_MODE_USER
#include <ndk/umtypes.h>
#include <ndk/extypes.h>
#include <ndk/rtlfuncs.h>

/*
 * @implemented
 */
void __cdecl
_global_unwind2(PEXCEPTION_REGISTRATION_RECORD RegistrationFrame)
{
#ifdef __GNUC__
   RtlUnwind(RegistrationFrame, &&__ret_label, NULL, 0);
__ret_label:
   // return is important
   return;
#else
#endif
}


/* VC++ extensions to Win32 SEH */
typedef struct _SCOPETABLE
{
  int previousTryLevel;
  int (*lpfnFilter)(PEXCEPTION_POINTERS);
  int (*lpfnHandler)(void);
} SCOPETABLE, *PSCOPETABLE;

typedef struct _MSVCRT_EXCEPTION_FRAME
{
  PEXCEPTION_REGISTRATION_RECORD *prev;
  void (*handler)(PEXCEPTION_RECORD, PEXCEPTION_REGISTRATION_RECORD,
                  PCONTEXT, PEXCEPTION_RECORD);
  PSCOPETABLE scopetable;
  int trylevel;
  int _ebp;
  PEXCEPTION_POINTERS xpointers;
} MSVCRT_EXCEPTION_FRAME;


typedef struct __JUMP_BUFFER
{
    unsigned long Ebp;
    unsigned long Ebx;
    unsigned long Edi;
    unsigned long Esi;
    unsigned long Esp;
    unsigned long Eip;
    unsigned long Registration;
    unsigned long TryLevel;
    /* Start of new struct members */
    unsigned long Cookie;
    unsigned long UnwindFunc;
    unsigned long UnwindData[6];
} _JUMP_BUFFER;

void
_local_unwind2(MSVCRT_EXCEPTION_FRAME *RegistrationFrame,
		      LONG TryLevel);

/*
 * @implemented
*/

void __stdcall _seh_longjmp_unwind(_JUMP_BUFFER *jmp)
{
    _local_unwind2((MSVCRT_EXCEPTION_FRAME*) jmp->Registration, jmp->TryLevel);
}