Is nexti confused by pushq?

Tom Tromey tom@tromey.com
Tue Feb 26 19:05:00 GMT 2019


>>>>> "David" == David Griffiths <dgriffiths@undo.io> writes:

David> Ok, so in my case this is generated code with no debug info (Java JIT
David> generated) so does that mean I shouldn't attempt to use nexti? (I've got
David> other issues which probably preclude using nexti anyway but just curious)

There are a few options to deal with this sort of problem.

As Jan said, the JIT could generate debug info using one of the
gdb-provided JIT interfaces.  That's kind of heavyweight but gives a lot
of control.

Another option is to write an unwinder in Python.  The crucial thing
here is to ensure that the frame ID is constant for the duration of a
frame.  In DWARF this is done by using the CFA as part of the identity;
for the JIT you'd want to do something similar.  I thought there was
already such an unwinder for OpenJDK at least... ?

Tom



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