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

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

jdenny added a comment.

In https://reviews.llvm.org/D47114#1170378, @george.karpenkov wrote:

> @dblaikie @probinson @jdenny In practice it seems hard to modify a command line arg for FileCheck, since it requires changing all tests.
>  I recently did a similar option in https://reviews.llvm.org/D49328, but used an environment variable instead.
>  Independently, `lit` has `-v` and `-vv` options which are also hard to set through the `ninja` invocation.
>
> Should we try to standardize on an environment variable, e.g. `DEBUG=1/2/3/4`? Ideally, it could be done automatically when the user does `ninja -v`, but AFAIK it does not set any environment variable which could be set from LIT.


A simple scheme that would give full control is LIT_FLAGS and FILECHECK_FLAGS.

I've not studied how lit and FileCheck handle conflicting flags, but some thought should be given to whether precedence is given to environment variables (whatever scheme we choose for those) or flags actually specified on the command line.


Repository:
  rL LLVM

https://reviews.llvm.org/D47114