[PATCH] D47114: [FileCheck] Implement -v and -vv for tracing matches

[Joel E. Denny via Phabricator via llvm-commits]

jdenny added a comment.

Maybe:

  Default: same as now
  LIT_DEBUG=1: LIT is passed -vv
  LIT_DEBUG=2: FileCheck is passed -v
  LIT_DEBUG=3: FileCheck is passed FILECHECK_VERBOSE (dumps all input on failure), plus same as above

That is, there might be cases where you want to know (1) what command ran and failed but you don't need to see (2) every single match for a long sequence of FileCheck directives.  The failing match might be sufficient.  What do you think?  In general, it's not clear to me how annoying unnecessary verbosity might become here.

Would buildbots be encouraged to set LIT_DEBUG at one of these levels?  What about ninja check targets?

LIT_FLAGS and FILECHECK_FLAGS could still offer a way to fine-tune debugging and other flags when running lit via ninja.  It seems logical for LIT_DEBUG to be applied first (as a coarse-grained setting), and then *_FLAGS would fine-tune it.  That is, if flags are processed left-to-right, then LIT_DEBUG prepends to *_FLAGS.  What do you think?

I see you dropped FileCheck -vv from your LIT_DEBUG list.  Given that FileCheck -vv is probably rarely useful when debugging tests (as opposed to debugging FileCheck itself), and given that FILECHECK_FLAGS could be used to add it, I think I agree with that decision.


Repository:
  rL LLVM

https://reviews.llvm.org/D47114