Rewrite on_unimplemented format string parser.
This PR rewrites the format string parser for `rustc_on_unimplemented` and `diagnostic::on_unimplemented`. I plan on moving this code (and more) into the new attribute parsing system soon and wanted to PR it separately.
This PR introduces some minor differences though:
- `rustc_on_unimplemented` on trait *implementations* is no longer checked/used - this is actually never used (outside of some tests) so I plan on removing it in the future.
- for `rustc_on_unimplemented`, it introduces the `{This}` argument in favor of `{ThisTraitname}` (to be removed later). It'll be easier to parse.
- for `rustc_on_unimplemented`, `Self` can now consistently be used as a filter, rather than just `_Self`. It used to not match correctly on for example `Self = "[{integer}]"`
- Some error messages now have better spans.
Fixes https://github.com/rust-lang/rust/issues/130627
This is serves as a collection of crashes so that accidental ICE fixes are tracked.
This was formally done at https://github.com/rust-lang/glacier but doing it inside
the rustc testsuite is more convenient.
It is imperative that a test in the suite causes an internal compiler error/panic
or makes rustc crash in some other way.
A test will "pass" if rustc exits with something other than 1 or 0.
When adding crashes from https://github.com/rust-lang/rust/issues, the
issue number should be noted in the file name (12345.rs should suffice)
and also inside the file via //@ known-bug #4321 if possible.
If you happen to fix one of the crashes, please move it to a fitting
subdirectory in tests/ui and give it a meaningful name.
Also please add a doc comment at the top of the file explaining why
this test exists. :)
Adding
Fixes #NNNNN
Fixes #MMMMM
to the description of your pull request will ensure the
corresponding tickets will be closed automatically upon merge.
The ticket ids can be found in the file name or the known-bug annotation
inside the testfile.
Please do not re-report any crashes that you find here!