[cfe-dev] How to report bug when compiler hangs

[Joerg Sonnenberger via cfe-dev]

On Thu, Sep 28, 2017 at 01:03:12PM -0700, Steven Peters via cfe-dev wrote:
> I've been digging into a compilation problem using the version of clang
> distrubuted with XCode 9 on macOS High Sierra. I narrowed the problem down
> to the transition from `-O1` to `-O2` for a target cpu of core2, and then I
> further narrowed it down to the `-vectorize-loops` option for clang. The
> challenge is that this problem manifests with clang failing to terminate. I
> don't know if it's a deadlock or getting stuck in an infinite loop, but I
> didn't see any guidance in the support documents about how to submit a bug
> report in a case like this.

Run the failing command with -save-temps, so that the preprocessed
source can be used to reproduce it. Double check that it fails with
upstream clang. If yes, submit a PR and attach the preprocessed source
together with any special flags needed to trigger it.

Joerg