[llvm-dev] Consolidating copies of google/benchmark in the repo (Was: Proposal: introduce dependency on abseil when building benchmarks)

[Michael Kruse via llvm-dev]

Am Di., 12. Okt. 2021 um 17:09 Uhr schrieb Mircea Trofin <mtrofin at google.com>:
> We can probably have a set of steps we try on the llvm-test-suite to find the dependency, like:
> 1 one of: user-specified `benchmark` dir,  user-specified llvm dir, or user specified directive to 'check installed' or to 'fetch latest'

That sounds fine.

> 2 try a heuristic: either ../llvm/utils/benchmark, or, if that's not there, try fetching it, and if this fails, ok, can't build
> Probably looking at ../llvm would 'just work' on the build bots, too? (meaning, without needing to change buildbot scripts)

No, sources are at different directories relative to the build
directory. Typically, this is '../llvm.src/llvm' [1,2], but I am not
sure for all builders, but others might be different [3]. Builds by
LNT might be more complicated [4].

Generally, I also don't really like hardcoding paths, makes
reproducing problems more difficult.

[1] https://github.com/llvm/llvm-zorg/blob/529cab62b53092cafe42c0a127480bede2806206/zorg/buildbot/builders/PollyBuilder.py#L23
[2] https://github.com/llvm/llvm-zorg/blob/529cab62b53092cafe42c0a127480bede2806206/zorg/buildbot/builders/OpenMPBuilder.py#L34
[3] https://github.com/llvm/llvm-zorg/blob/529cab62b53092cafe42c0a127480bede2806206/zorg/buildbot/builders/ClangBuilder.py#L267
[4] https://github.com/llvm/llvm-zorg/blob/529cab62b53092cafe42c0a127480bede2806206/zorg/buildbot/builders/ClangBuilder.py#L551

Michael