[lit] Add instructions to run lit's test suite

[modocache]

Oops, forgot a backslash.

[modocache]

@ddunbar I looked around but couldn't determine whether these tests run as part of LLVM's test suite. Is there anything in place to make sure these don't regress? Or is it up to contributors to ensure they pass?

Also, could you confirm for me that these all currently pass?

[• ddunbar]

LGTM, thanks!

I believe they do all pass, but they are *not* (IIRC) wired up to run as part of LLVM's tests. We should definitely do that.

One long term project I am interested in is moving lit out into its own project that LLVM just has a process for adopting. That will require some coordination with the community, but should help with lit development.

[beanz]

@cmatthews may remember, but I think there was a discussion about adding lit's tests to check-llvm in the last year or so. I don't remember why it wasn't done.

At the very least we should wire up a CMake target to run the lit tests.

[• ddunbar]

I think we should just wire it up with all the other tests, from lits perspective it would just be another test suite (like we do with the regular tests and the unit tests).

[• ddunbar]

https://llvm.org/svn/llvm-project/llvm/trunk@282525

[beanz]

Since we have CMake wired up to create targets for every sub directory under tests, we should really have a 'check-lit' target too.

[• ddunbar]

Ah, got it... that's a new feature to me, I am so out of the loop. :/

utils/lit/README.txt

 ===============================
  lit - A Software Testing Tool
 ===============================
 
 lit is a portable tool for executing LLVM and Clang style test suites,
 summarizing their results, and providing indication of failures. lit is designed
 to be a lightweight testing tool with as simple a user interface as possible.
 
+=====================
+ Contributing to lit
+=====================
+
+Please read the TODO file in this directory for ideas on what to work on.
+Before submitting patches, run the test suite to ensure nothing has regressed:
+
+    # From within your LLVM source directory.
+    utils/lit/lit.py \
+        --path /path/to/your/llvm/build/bin \
+        utils/lit/tests
+
+Note that lit's tests depend on 'not' and 'FileCheck', LLVM utilities.
+You will need to have built LLVM tools in order to run lit's test suite
+successfully.
+