don't point at nonexisting code beyond EOF when warning about delims
Previously we would show this:
```
warning: unnecessary braces around block return value
--> /tmp/bad.rs:1:8
|
1 | fn a(){{{
| ^ ^
|
= note: `#[warn(unused_braces)]` on by default
help: remove these braces
|
1 - fn a(){{{
1 + fn a(){{
|
```
which is now hidden in this case.
We would create a span spanning between the pair of redundant {}s but there is only EOF instead of the `}` so we would previously point at nothing. This would cause the debug assertion ice to trigger. I would have loved to just only point at the second delim and say "you can remove that" but I'm not sure how to do that without refactoring the entire diagnostic which seems tricky. :( But given that this does not seem to regress any other tests we have, I think this edge-casey enough be acceptable.
Fixes https://github.com/rust-lang/rust/issues/107423
r? `@compiler-errors`
Especially when trying to diagnose runaway future sizes, it might be
more intuitive to sort the variants according to the control flow
(aka their yield points) rather than the size of the variants.
Change wording from "nullable" to "default".
Introduce a trait `IsDefault` for detecting values that are encoded as zeros or not encoded at all.
Add panics to impossible cases.
Some other minor cleanups.
Less import overhead for errors
This removes huge (3+ lines) import lists found in files that had their error reporting migrated. These lists are bad for developer workflows as adding, removing, or editing a single error's name might cause a chain reaction that bloats the git diff. As the error struct names are long, the likelihood of such chain reactions is high.
Follows the suggestion by `@Nilstrieb` in the [zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/147480-t-compiler.2Fwg-diagnostics/topic/massive.20use.20statements) to replace the `use errors::{FooErr, BarErr};` with `use errors;` and then changing to `errors::FooErr` on the usage sites.
I have used sed to do most of the changes, i.e. something like:
```
sed -i -E 's/(create_err|create_feature_err|emit_err|create_note|emit_fatal|emit_warning)\(([[:alnum:]]+|[A-Z][[:alnum:]:]*)( \{|\))/\1(errors::\2\3/' path/to/file.rs
```
& then I manually fixed the errors that occured. Most manual changes were required in `compiler/rustc_parse/src/parser/expr.rs`.
r? `@compiler-errors`
Move code in `rustc_driver` out to a new `rustc_driver_impl` crate to allow pipelining
That adds a `rustc_shared` library which contains all the rustc library crates in a single dylib. It takes over this role from `rustc_driver`. This is done so that `rustc_driver` can be compiled in parallel with other crates. `rustc_shared` is intentionally left empty so it only does linking.
An alternative could be to move the code currently in `rustc_driver` into a new crate to avoid changing the name of the distributed library.
Previously we would show this:
```
warning: unnecessary braces around block return value
--> /tmp/bad.rs:1:8
|
1 | fn a(){{{
| ^ ^
|
= note: `#[warn(unused_braces)]` on by default
help: remove these braces
|
1 - fn a(){{{
1 + fn a(){{
|
```
which is now hidden in this case.
We would create a span spanning between the pair of redundant {}s but there is only EOF instead of the `}` so we would previously point at nothing.
This would cause the debug assertion ice to trigger.
I would have loved to just only point at the second delim and say "you can remove that" but I'm not sure how to do that without refactoring the entire diagnostic which seems tricky. :(
But given that this does not seem to regress any other tests we have, I think this edge-casey enough be acceptable.
Fixes https://github.com/rust-lang/rust/issues/107423
r? @compiler-errors
Retry opening proc-macro DLLs a few times on Windows.
On Windows, the compiler [sometimes](https://users.rust-lang.org/t/error-loadlibraryexw-failed/77603) fails with the message `error: LoadLibraryExW failed` when trying to load a proc-macro crate. The error seems to occur intermittently, similar to https://github.com/rust-lang/rust/issues/86929, however, it seems to be almost impossible to reproduce outside of CI environments and thus very hard to debug. The fact that the error only occurs intermittently makes me think that this is a timing related issue.
This PR is an attempt to mitigate the issue by letting the compiler retry a few times when encountering this specific error (which resolved the issue described in https://github.com/rust-lang/rust/issues/86929).
