[LLVMdev] DWARF validation?

[David Blaikie]

On Thu, Mar 12, 2015 at 1:06 PM, Talin <viridia at gmail.com> wrote:

> When developing an LLVM-based frontend, is there a way to automatically
> verify that the DWARF metadata being emitted is correct? Specifically, I'd
> like to be able to write some sort of unit test that will fail if the DWARF
> is invalid. I don't just want to test whether the LLVM metadata statements
> are well-formed - if I make a change that will cause lldb or gdb to barf, I
> would like to have at least a 50% chance to catch this beforehand. I can't
> really run the debugger in a unit test, and even if I could the resulting
> error message is likely to be poor. This means that the validator would
> have to incorporate knowledge of the DWARF standard. Is there such a thing?
>
> Trying to ensure that DWARF is correct is one of the reasons why I
> abandoned my earlier LLVM project a few years ago, it was simply too hard
> then. I'm just wondering if the situation has improved in the last several
> years.
>

Not substantially, that I know of - you can verify the debug info metadata
itself (there's a DebugInfoVerifier - I forget what flag you need to pass
to run it) & it'll warn and drop the metadata if it's ill-formed, but that
doesn't guarantee that a debugger will like what LLVM generates from that
metadata.

We have a buildbot that runs GDB's test suite against Clang to verify that
the debug info provided is usefully debuggable.

- David


>
>
> --
> -- Talin
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150312/5b07f8de/attachment.html>