rustc: Tweak expansion of #[proc_macro] for 2018
The syntactical expansion of `#[proc_macro]` and related attributes currently
contains absolute paths which conflicts with a lint for the 2018 edition,
causing issues like #52214. This commit puts a band-aid on the issue by ensuring
that procedural macros can also migrate to the 2018 edition for now by tweaking
the expansion based on what features are activated. A more long-term solution
would probably tweak the edition hygiene of spans, but this should do the trick
for now.
Closes#52214
Remove most of `PartialEq` and `Hash` impls from AST and HIR structures
Continuation of https://github.com/rust-lang/rust/pull/49326, prerequisite for removing `PartialEq` for `Ident`.
Now also the documentations of `subsec_millis`, `subsec_micros`, `as_millis` and `as_micros` make clear that the fractional nanosecond component is rounded down to whole units.
Set opt-level = 3 the third time.
This PR reverts #51165 (set -O2 for fixing #50867),
which reverted #50329 (set -O3),
which was second attempt of #48204 (set -O3, closed due to Windows segfault that is fixed now),
which reverted #42123 (set -O2 to fix spurious Windows segfaults),
which reverted #41967 (set -O3).
Since we have found the root cause of #50867, this optimization could be tried again.
Last time we've found that setting -O3 regressed the wall time of NLL (https://github.com/rust-lang/rust/pull/50329#issuecomment-388084894), so we may need another perf run to confirm. I'd like to check this *after* the LLVM 7 upgrade #51966 has been merged, so marking this as <kbd>S-blocked</kbd> for now.
Don't display default generic parameters in diagnostics that compare types
In errors like:
```
expected type: `RawVec<foo, Global>`
found type: `foo`
```
`RawVec` being defined as `RawVec<T, A: Alloc = Global>`, the error is better written as
```
expected type: `RawVec<foo>`
found type: `foo`
```
In fact, that is already what happens when `foo` is not an ADT, because in that case, the diagnostic handler doesn't try to highlight something, and just uses the `Display` trait instead of its own logic.
e.g.
```
expected type: `RawVec<usize>`
found type: `usize`
```
Previously we'd attempt to recompile them and that would fail since
we've essentially not built the entire compiler yet, or we're faking
that fact. This commit should make us ignore the codegen backend build
as well.
Unlike the other compile steps, there is no CodegenBackendLink step that
we run here, because that is done later as a part of assembling the
final compiler and as an explicit function call.
Add the `amdgpu-kernel` ABI.
Technically, there are requirements imposed by the LLVM
`AMDGPUTargetMachine` on functions with this ABI (eg, the return type
must be void), but I'm unsure exactly where this should be enforced.
Technically, there are requirements imposed by the LLVM
`AMDGPUTargetMachine` on functions with this ABI (eg, the return type
must be void), but I'm unsure exactly where this should be enforced.
Preliminary work for incremental ThinLTO.
Since implementing incremental ThinLTO is a bit more involved than I initially thought, I'm splitting out some of the things that already work. This PR (1) adds a way accessing some ThinLTO information in `rustc` and (2) does some cleanup around CGU/object file naming (which makes things quite a bit nicer).
This is probably best reviewed one commit at a time.
Don't silently ignore invalid data in target spec
This is technically a breaking change, but only because invalid data was previously silently being ignored.
task: remove wrong comments about non-existent LocalWake trait
~~A `LocalWaker` is specifically `!Send `, and the unsafety comment around
`LocalWaker::new` only specifies that it be safe to call `wake_local`.
One could then accidentally promote a `LocalWaker` into a `Waker`, which
is universally `Send`, simply via `Waker::from(local_waker)`. A
`LocalWaker` the was built expecting to not be `Send`, such as using
`Rc`, could be sent to other threads safely.~~
~~Separately, though somewhat related, `Context` holds a `&LocalWaker`
internally, and exposes a `waker() -> &Waker` method. This simply
transmutes the `&LocalWaker` to `&Waker`, which would be unsound, except
that you can't "send" a `&Waker`, you'd need to clone it first. Since
`UnsafeWake::clone_raw` requires that it return a `Waker`, the transmute
is not unsound. The transmuted `LocalWaker` will be promoted to a
`Waker` correctly.~~
~~That would mean that if `UnsafeWake::clone_raw` were to be changed, such
as returning `Self` instead of `Waker`, this would no longer be sound.
Thus, this also adds a comment to `clone_raw` to remember this.~~
r? @cramertj
Deny bare trait objects in the rest of rust
Add `#![deny(bare_trait_objects)]` to all the modules not covered before (those did not require code changes) that I consider applicable (I left out shims) in order to futureproof them.
