Re: Debugging a NullPointerException in fstack

[Tom Tromey <tromey@redhat.com>]

>>>>> "Ray" == Ray Ruvinskiy <rruvinsk@sybase.com> writes:

Ray> I was able to successfully step through the code in gdb but not
Ray> to print out object contents.

Yeah, there are oddities here sometimes.  I just call the debug
printers instead:

call _Jv_Debug(obj)  # print OBJ
call _Jv_DeepDebug(obj, depth)  # print OBJ and sub-objects to DEPTH
call _Jv_StaticDeepDebug(obj, depth) # like _Jv_DeepDebug, but also
                                     # show static fields

Ray> (gdb) p pid
Ray> $12 = Expected a negative vbase offset (old compiler?)

I never remember what this means.  Basically the gcj support in gdb is
ok but not super.  So, you'll run into problems on occasion.

Ray> Also, gdb displayed many warnings along the following lines:

Ray> warning: Missing the separate debug info file: /usr/lib/debug/.build- 
Ray> id/fa/841219472d35412ad631ad0f0fabb78e5c1957.debug

You are missing debuginfo for various system libraries.
This is harmless unless you want to step into one of them.
Often, having info for libgcj is helpful.

Tom