Currently there is no testing for ClangTypeParser even though it's used in
production. This is because adding integration tests is very hard: they require
testing the build time behaviour at runtime, or else they'd be build failures
intead of test failures. There's a PR available for integration tests but it's
incomplete.
In contrast ClangTypeParser can be sort of unit tested. This follows the
structure of `test/test_drgn_parser.cpp` with some differences. There is a
tonne of boilerplate for setting up the Clang tool, and this set of testing
operates on type names instead of OID functions. The new tests are also
incredibly slow as they compile the entire `integration_test_target.cpp` (which
is huge) for every test case. I don't think this is avoidable without
compromising the separation of the tests somewhat due to the way Clang tooling
forces the code to be structured.
Currently I can't run these tests locally on a Meta devserver due to some
weirdness with the internal build and the `compile_commands.json` file. They
run in the CI and on any other open source machine though so I'm happy to merge
it - it's still useful. I'm going to close the PR to change the devserver build
given I'll be unable to follow up if it ends up being bad.
Test plan:
- CI
a014cdd4de