Implement `MappedMutexGuard`, `MappedRwLockReadGuard`, and `MappedRwLockWriteGuard`.
ACP: https://github.com/rust-lang/libs-team/issues/260
Tracking issue: https://github.com/rust-lang/rust/issues/117108
<details> <summary> (Outdated) </summary>
`MutexState`/`RwLockState` structs
~~Having `sys::(Mutex|RwLock)` and `poison::Flag` as separate fields in the `Mutex`/`RwLock` would require `MappedMutexGuard`/`MappedRwLockWriteGuard` to hold an additional pointer, so I combined the two fields into a `MutexState`/`RwLockState` struct. This should not noticeably affect perf or layout, but requires an additional field projection when accessing the former `.inner` or `.poison` fields (now `.state.inner` and `.state.poison`).~~ If this is not desired, then `MappedMutexGuard`/`MappedRwLockWriteGuard` can instead hold separate pointers to the two fields.
</details>
The doc-comments are mostly copied from the existing `*Guard` doc-comments, with some parts from `lock_api::Mapped*Guard`'s doc-comments.
Unresolved question: Are more tests needed?
`get_path_for_executable` will now first check `$CARGO_HOME` before falling back to searching `$PATH`.
rustup is the recommended way to manage rust toolchains, therefore should be picked before the
system toolchain.
Add short flag -V for consistency with other rust tooling
Minor change to add the `-V` short flag to `rust-analyzer` to bring it in-line with other rust tooling such as:
> rustc -V
```bash
rustc 1.76.0 (07dca489a 2024-02-04)
```
> rustup -V
```bash
rustup 1.26.0 (5af9b9484 2023-04-05)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.76.0 (07dca489a 2024-02-04)`
```
> cargo -V
```bash
cargo 1.76.0 (c84b36747 2024-01-18)
```
fix: Recompiles due to RUSTC_BOOTSTRAP
Some packages (e.g. thiserror) force a recompile if the value of the `RUSTC_BOOTSTRAP` env var changes. RA sets the variable to 1 in order to enable rustc / cargo unstable options. This causes flapping recompiles when building outside of RA.
Fixes#15057
internal: Optimize salsa memory usage
Reduces memory on self by ~20mb for me, there is a few more mb to save here if we made LRU caching opt-in, as currently every entry in a memoized query will store an `AtomicUsize` for the LRU.
fix: Fix proc-macro server not accounting for string delimiters correctly
Fixes https://github.com/rust-lang/rust-analyzer/issues/16622
Note that this is a bug a in the proc-macro server, so this won't be fixed until the next subtree sync
Make intrinsic fallback bodies cross-crate inlineable
This change was prompted by the stage1 compiler spending 4% of its time when compiling the polymorphic-recursion MIR opt test in `unlikely`.
Intrinsic fallback bodies like `unlikely` should always be inlined, it's very silly if they are not. To do this, we enable the fallback bodies to be cross-crate inlineable. Not that this matters for our workloads since the compiler never actually _uses_ the "fallback bodies", it just uses whatever was cfg(bootstrap)ped, so I've also added `#[inline]` to those.
See the comments for more information.
r? oli-obk
Remove useless `'static` bounds on `Box` allocator
#79327 added `'static` bounds to the allocator parameter for various `Box` + `Pin` APIs to ensure soundness. But it was a bit overzealous, some of the bounds aren't actually needed.
Add "algebraic" fast-math intrinsics, based on fast-math ops that cannot return poison
Setting all of LLVM's fast-math flags makes our fast-math intrinsics very dangerous, because some inputs are UB. This set of flags permits common algebraic transformations, but according to the [LangRef](https://llvm.org/docs/LangRef.html#fastmath), only the flags `nnan` (no nans) and `ninf` (no infs) can produce poison.
And this uses the algebraic float ops to fix https://github.com/rust-lang/rust/issues/120720
cc `@orlp`
`cargo rustc -- <args>` first builds dependencies then calls `rustc <args>` for the current package. Here, we don't want to build dependencies, we just want to call `rustc --print`. An unstable `cargo rustc` `--print` command bypasses building dependencies first. This speeds up execution of this code path and ensures RA doesn't recompile dependencies with the `RUSTC_BOOTSRAP=1` env var flag set.
Note that we must pass `-Z unstable-options` twice, first to enable the `cargo` unstable `--print` flag, then later to enable the unstable `rustc` `target-spec-json` print request.
match lowering: simplify empty candidate selection
In match lowering, `match_simplified_candidates` is tasked with removing candidates that are fully matched and linking them up properly. The code that does that was needlessly complicated; this PR simplifies it.
The overall change isn't big but I split it up into tiny commits to convince myself that I was correctly preserving behavior. The test changes are all due to the first commit. Let me know if you'd prefer me to split up the PR to make reviewing easier.
r? `@matthewjasper`
match lowering: eagerly simplify match pairs
This removes one important complication from match lowering. Before this, match pair simplification (which includes collecting bindings and type ascriptions) was intertwined with the whole match lowering algorithm.
I'm avoiding this by storing in each `MatchPair` the sub-`MatchPair`s that correspond to its subfields. This makes it possible to simplify everything (except or-patterns) in `Candidate::new()`.
This should open up further simplifications. It will also give us proper control over the order of bindings.
r? `@matthewjasper`
Some packages (e.g. thiserror) force a recompile if the value of the `RUSTC_BOOTSTRAP` env var changes. RA sets the variable to 1 in order to enable rustc / cargo unstable options it uses. This causes flapping recompiles when building outside of RA.
As of Cargo 1.75 the `--keep-going` flag is stable. This change uses the flag without `RUSTC_BOOTSTRAP` if the Cargo version is >= 1.75, and drops `--keep-going` otherwise. This fixes build script recompilation.
internal: Attempt to add a timeout to rustc-tests
Looks like some new test is stuck, this might help with figuring that out, though it unfortunately won't if its a chalk hang (which is the most likely)
