[LLVMdev] DWARF 2/3 backwards compatibility?

Robinson, Paul Paul.Robinson at am.sony.com
Thu Oct 18 14:58:54 PDT 2012

> > Since GDB already has a good and standard test infrastructure, it'd
> > likely get a good chunk of bad Dwarf our of the way before you start
> > worrying about Lauterbach's specifics.
> The gdb testsuite is pretty good as a "what's expected" set of tests,
> however, one thing to keep in mind is that a lot of the checks aren't
> particularly fuzzy. I.e. it checks what's expected but it's not
> necessarily valid dwarf that it's looking for but a particular
> behavior.

And that behavior is not necessarily related to the DWARF.  My Ubuntu
workstation consistently gets flakey results from the multi-threaded
GDB tests, which have exactly zero relation to what's in the DWARF.

(consistently flakey... ooh, dear.)

> > A bad/confused dwarf record fails multiple tests without a way to map a
> > failure back to dwarf.
> >
> I'm not sure what you mean here.

I don't know what Rick has experienced, but I've seen that a DWARF
problem can lead to an arbitrary number of GDB failures, none of which
necessarily make it obvious what the problem is with the DWARF.
For example, when tweaking the placement of the end_prologue flag
in the line table made the "list" command break.  Eh???  In that case at
least I knew what I'd tweaked; coming on it cold, there's no way to know
what's going on.


More information about the llvm-dev mailing list