d039af3309
See the discussion in PR https://github.com/llvm/llvm-project/pull/131650 on why we need to clear the errno at the beginning of some tests, and outlining the various solutions. Introduce ErrnoCheckingTest base class and use it for unlink_test as an example.
The LLVM libc unit test framework
This directory contains a lightweight implementation of a gtest like unit test framework for LLVM libc.
Why not gtest?
While gtest is great, featureful and time tested, it uses the C and C++ standard libraries. Hence, using it to test LLVM libc (which is also an implementation of the C standard libraries) causes various kinds of mixup/conflict problems.
How is it different from gtest?
LLVM libc's unit test framework is much less featureful as compared to gtest. But, what is available strives to be exactly like gtest.
Will it be made as featureful as gtest in future?
It is not clear if LLVM libc needs/will need every feature of gtest. We only intend to extend it on an as needed basis. Hence, it might never be as featureful as gtest.