[llvm-dev] [RFC] Compiled regression tests.

[David Greene via llvm-dev]

Hal Finkel via llvm-dev <llvm-dev at lists.llvm.org> writes:

> I definitely agree that we should not be trying to do this kind of 
> checking using textual metadata-node matching in FileCheck. The 
> alternative already available is to add an analysis pass with some kind 
> of verifier output. This output, not the raw metadata itself, can be 
> checked by FileCheck. We also need to check the verification code, but 
> at least that's something we can keep just in one place. For parallel 
> annotations, we already have such a thing (we can run opt -loops 
> -analyze; e.g., in 
> test/Analysis/LoopInfo/annotated-parallel-complex.ll). We also do this 
> kind of thing for the cost model (by running with -cost-model -analyze). 
> To what extent would making more-extensive use of this technique address 
> the use cases you're trying to address?

Analysis tests are definitely useful but I don't think they're
sufficient.  By their nature, analysis tests run in a "sanitized"
environment.  The test specifies exactly what is analyzed and no other
passes are run.

>From my quick glance at Michael's example test, it's checking that the
inlining pass does something specific with metadata:

; Check that the access groups (llvm.access.group) are correctly merged.

I suppose one could create an "analysis" that just dumps out metadata
information.  Is that what you have in mind?  That seems like a lot of
overhead just to write a test to check metadata.

                      -David