Stack traces, etc.

Tue Dec 3 07:58:00 GMT 2002

Tom Tromey writes:
 > >>>>> "Andrew" == Andrew Haley <aph@redhat.com> writes:
 > 
 > Andrew> Revised, VMThrowable reinstated, testing now. Checkin
 > Andrew> tomorrow unless anyone complains.
 > 
 > No complaint here.
 > 
 > Andrew> + #ifdef INTERPRETER
 > Andrew> + extern void _Jv_StartOfInterpreter (void);
 > Andrew> + extern void _Jv_EndOfInterpreter (void);
 > 
 > Anthony, you once said your stack trace patch used the address of the
 > libffi stub to keep track of interpreted frames. Can you tell me how
 > to do this? How do I find the size of the stub?
 > 
 > This seems like a cleaner implementation, provided we get the GC
 > behavior correct. And it will fix PR 8170 (we need a hack similar to
 > the above for JNI methods).
The Right Way to do it is something like this
 _Jv_frame_info *frame = GET_FRAME (n);
 void *p = _Unwind_FindEnclosingFunction (frame->addr);
 if (p == &interpreterf1 
 || p == &interpreterf2 ...
or, alternatively something like
 _Jv_frame_info *frame = GET_FRAME (n);
 gnu::gcj::runtime::MethodRef *ref 
 = getCompiledMethodRef ((gnu::gcj::RawData *)frame->addr);
 if (ref && ref->klass == &gnu::gcj::interpreter)
 ... it's an interpreter function ...
Andrew.