testing

Testing gccrs in the wild

Requirements

ftf >= 0.4

cargo install ftf

submodules

Either clone the repository using the --recursive flag, or initialize the submodules afterwards using the following command:

git submodule update --init

Generate the parsing test-suite

The test-suite adaptor is a simple program in charge of generating a sensible test-suite for gccrs from rustc's test-suite, as well as making sure our testsuite is valid rust code. For now, there are two "passes" available:

1. A parsing test-suite, where the application launches rustc with the -Z parse-only flag and keeps track of the exit code, in order to make sure that gccrs with the -fsyntax-only flag has the same behavior.

2. A validation test-suite, where we make sure that rustc can compile gccrs' dejagnu test-suite. This helps in ensuring that our tests are proper rust code.

Running the adaptor is time consuming: It takes roughly 5 minutes to generate the parsing test-suite on a powerful machine.

It also absolutely hammers your computer by launching $(nproc) instances of rustc to create the test-suite baseline.

You can run the application either in debug or release mode: As it is extremely IO-intensive, it does not benefit a lot from the extra optimizations (for now!).

You can generate a testsuite using the following arguments:

--gccrs,-g

The gccrs executable you want to test. The command will be launched similarly to how an executable is launched from the shell, so you can either specify a relative path to an executable, an absolute path, or simply the name of an executable present in your path.

One way to do this is to copy a freshly built rust1 from your gccrs local copy, and pass --gccrs './rust1' as an argument. If you've copied your whole build directory, the argument would look something like --gccrs './build/gcc/rust1.

If you have gccrs installed on your system, you can also simply pass --gccrs gccrs. Be careful in that running the testsuite with a full compiler driver will obviously be much longer.

--rustc,-r

rustc executable to use and test. Similar rules apply.

--rust-path

Path to the cloned rustc repository to extract test cases from.

--gccrs-path

Path to the cloned gccrs repository to extract test cases from.

--output-dir,-o

Directory to create and in which to store the adapted test cases. The directory will be created by the application.

--yaml,-y

Path of the ftf test-suite file to create.

--pass,-p

Pass to run and generate a test suite from. The currently available passes are

Pass	Description
gccrs-parsing	Tests gccrs's parser. This allows testing gccrs against rustc in parsing-mode (-Z parse-only and -fsyntax-only)
rustc-dejagnu	Launch rustc against our dejagnu testsuite. This allows validating gccrs's testsuite, making sure that tests are proper rust code
gccrs-rustc-success	Launch gccrs against all successful testcases in the rustc testsuite
gccrs-rustc-success-no-std	Launch gccrs against all successful testcases in the rustc testsuite in #[no_std] mode
gccrs-rustc-success-no-core	Launch gccrs against all successful testcases in the rustc testsuite in #[no_core] mode
blake3	Launch gccrs on the Blake3 cryptography project
libcore	Launch gccrs on various version of the core library
ast-export	Make sure gccrs exports valid Rust code

Running the test-suite

If everything went smoothly, you should simply be able to run ftf on the generated YAML file:

ftf -f <generated_yaml>

Typical first invocation

> cargo run -- \
	--gccrs 'path/to/crab1' --rustc rustc \
	--gccrs-path path/to/gccrs/ --rust-path path/to/rust/ \
	--output-dir sources/ --yaml testsuite.yml \
	--pass gccrs-parsing
> ftf -f testsuite.yml -j$(nproc)

Running ftf on a single thread (default behavior if you do not pass a -j/--jobs argument) is not recommended as running through the whole parsing test-suite will easily take tens of minutes.

Re-running the test-suite with an updated compiler

If you have already generated a test-suite and would simply like to run an updated version of gccrs, you can reuse the same YAML file.

> cp <your-gccrs-build-dir>/gcc/rust1 ./rust1
> ftf -f testsuite.yml -j$(nproc)