[llvm-dev] Passes to add/validate synthetic debug info

[Davide Italiano via llvm-dev]

On Mon, Dec 4, 2017 at 1:44 PM, Vedant Kumar <vsk at apple.com> wrote:
> Hi,
>
> I've prototyped a pair of passes which 1) add synthetic debug info to a
> Module and 2) determine how much of that info is lost. The idea is to make
> it easier to write targeted test cases for debug info preservation. For
> example, here is a quick way to test that Mem2Reg doesn't drop debug info
> from one test input:
>
> ; RUN: opt < %s -debugify -mem2reg -check-debugify -S 2>&1 | FileCheck %s
> ; CHECK: CheckDebugify: PASS
>
>
> So far, I've used this utility to identify problems in LSR and instcombine
> (haven't gotten around to filing bugs yet). There's some more discussion
> about this utility on the thread "RFC: [GlobalISel] Towards a generic MI
> combiner framework", where Amara and Daniel suggested trying something
> similar at the MI level.
>
> I've put the passes up for review here https://reviews.llvm.org/D40512. I
> just wanted to ping llvm-dev to raise awareness about the proposed passes,
> and to see if anyone in the community has concerns/feedback.
>
> thanks,
> vedant

After you addressed all my comments, this is pretty close to me. I'll
take another look today or tomorrow but I'm confident we can iterate
in tree.
In other words, +1 from me (you may want to wait a week or so before
committing so that people have a chance to take a look).


-- 
Davide

"There are no solved problems; there are only problems that are more
or less solved" -- Henri Poincare