Should tests be run with julia --check-bounds=yes?

[ali-ramadhan]

The codebase makes extensive use of @inbounds, for good reason and usually pretty safely. But does it make sense to run the tests with --check-bounds=yes to catch any cases of out-of-bounds memory accesses?

Out of bounds accesses don't always produce an error and can silently lead to undefined behavior.

This may lead to slightly slower tests, although I doubt it would slow them down by much as most of the time is spend on compiling.

Might help with discovering certain issues sooner. Probably #3615 but maybe not #3320.

X-Ref: #3682 (comment)

[simone-silvestri]

The tests should run with --check-bounds=yes automatically. I think that when calling Pkg.test() the testing environment automatically activates the 0 optimization flag (-O0) and the bounds checking flag --check-bounds=yes, but I cannot find a reference at the moment.

[ali-ramadhan]

Ah you're right! I forgot that Pkg.test() did that. I found the docs for it: https://pkgdocs.julialang.org/v1/api/#Pkg.test

I think the -O0 flag is something Oceananigans.jl does on Buildkite though: https://github.com/CliMA/Oceananigans.jl/blob/main/.buildkite/pipeline.yml