Question

I need to translate structured exceptions manually, using the current translator.

How do I ‘get’ the value someone has set by _set_se_translator?

Answer 1

Better (new) way

I didn’t realize this at first, but the SE translator is thread-local, not process-wide.

So this is actually the best (and easiest) solution:

_se_translator_function _get_se_translator(void) {
    _se_translator_function translator = _set_se_translator(NULL);  // temporary
    _set_se_translator(translator);  // Restore the old value
    return translator;
}

Hacky (old) way

There is no direct way to do this, but if you’re going to risk some incompatibility and delve into the Visual C runtime’s internals, you can hack up a solution like this:

_se_translator_function __cdecl _get_se_translator(void) {
    unsigned char const *p = (unsigned char const *)(&__uncaught_exception);
    struct _tiddata {
        unsigned long _tid;
        void *_thandle;
        int _terrno; unsigned long _tdoserrno;
        unsigned int _fpds;
        unsigned long _holdrand;
        char *_token; wchar_t *_wtoken;
        unsigned char *_mtoken;
        char *_errmsg; wchar_t *_werrmsg;
        char *_namebuf0; wchar_t *_wnamebuf0;
        char *_namebuf1; wchar_t *_wnamebuf1;
        char *_asctimebuf; wchar_t *_wasctimebuf;
        void *_gmtimebuf;
        char *_cvtbuf;
        unsigned char _con_ch_buf[5];
        unsigned short _ch_buf_used;
        void *_initaddr; void *_initarg;
        void *_pxcptacttab;
        void *_tpxcptinfoptrs;
        int _tfpecode;
        void *ptmbcinfo; void *ptlocinfo;
        int _ownlocale;
        unsigned long _NLG_dwCode;
        void *_terminate; void *_unexpected;
        _se_translator_function _translator;
    };
    if (p[0] == 0x48) /* sub RSP, 0x28 */ { p += 4; }  // x64 only
    if (p[0] == 0xE8) /* call _getpid */ { ++p; }  // must be true
    void const *_getptd = p + *(long *)p + sizeof(long);
    return ((struct _tiddata *(__cdecl *)(void))_getptd)()->_translator;
}