Add benchmark tests for mbe

[edwin0cheng]

This PR add more real world tests dumped from rust-analyzer analysis-stats . to benchmark its performance.

cc #7513

r? @matklad

[edwin0cheng]

CI had passed. I forgot I have to ignore some tidy tests in test fixtures :)

[matklad]

Hm, 6mb file seems a bit excessive to keep in git repo 🤣

It was generated by some code, right? Lets' maybe ignore this file via .gitignore, but commit the code to create it. So that benchmargks look like this:

#[test]
fn benchmark_foo() {
    if skip_slow_tests() { return; }
    // Uses Once to create `target/bench_data/lotsofrust.rs`
    let bf = BenchmarkFixtures::new();
    let file: String = bf.get("many-macros.rs").
}

I think it does make sense to write to disk, so that benchmark generation doesn't affect profiles

[edwin0cheng]

Its generated by some hacky awk scripts and adhoc dbg output... but well, I agree that it is too large :)

Let me try to write a proper generation code and see how’s it is.

[edwin0cheng]

Instead of a large file for macro invocation fixtures, I am able to generate invocations from MacroRules. The generate code itself is quite fast (and dirty) so I decided no need to write it back to disk.

It is ready to review again :)

[matklad]

bors r+

Nice!

[bors]

Build succeeded:

• Rust (macos-latest)
• Rust (ubuntu-latest)
• Rust (windows-latest)
• TypeScript (ubuntu-latest)
• TypeScript (windows-latest)