once cell renamings
This PR does the renamings proposed in https://github.com/rust-lang/rust/issues/74465#issuecomment-1153703128
- Move/rename `lazy::{OnceCell, Lazy}` to `cell::{OnceCell, LazyCell}`
- Move/rename `lazy::{SyncOnceCell, SyncLazy}` to `sync::{OnceLock, LazyLock}`
(I used `Lazy...` instead of `...Lazy` as it seems to be more consistent, easier to pronounce, etc)
```@rustbot``` label +T-libs-api -T-libs
Since RFC 3052 soft deprecated the authors field anyway, hiding it from
crates.io, docs.rs, and making Cargo not add it by default, and it is
not generally up to date/useful information, we should remove it from
crates in this repo.
- Add clippy_dev to the rust workspace
Before, it would give an error that it wasn't either included or
excluded from the workspace:
```
error: current package believes it's in a workspace when it's not:
current: /home/joshua/rustc/src/tools/clippy/clippy_dev/Cargo.toml
workspace: /home/joshua/rustc/Cargo.toml
this may be fixable by adding `src/tools/clippy/clippy_dev` to the `workspace.members` array of the manifest located at: /home/joshua/rustc/Cargo.toml
Alternatively, to keep it out of the workspace, add the package to the `workspace.exclude` array, or add an empty `[workspace]` table to the package's manifest.
```
- Change clippy's copy of compiletest not to special-case
rust-lang/rust. Using OUT_DIR confused `clippy_dev` and it couldn't find
the test outputs. This is one of the reasons why `cargo dev bless` used
to silently do nothing (the others were that `CARGO_TARGET_DIR` and
`PROFILE` weren't set appropriately).
- Run clippy_dev on test failure
I tested this by removing a couple lines from a stderr file, and they
were correctly replaced.
- Fix clippy_dev warnings
Deprecate util/dev in favor of cargo alias
This means one less shell script and a bit more cross-platform support
for contributors.
If you've been using `./util/dev` before, this now becomes `cargo dev`.
The key part of this change is found in `.cargo/config` where an alias for calling the `clippy_dev` binary is defined.
changelog: none
This allows us to use the method in both `fmt.rs` and `lib.rs` in
multiple places. The downside is that we panic inside the method now,
instead of using the error handling in `fmt.rs`. We may want to
centralize the error handling for clippy_dev at some point, though.
If you've been using `./util/dev` before, this now becomes `cargo dev`.
The key part of this change is found in `.cargo/config`.
This means one less shell script and a bit more cross-platform support
for contributors.
`must_use_unit` lints unit-returning functions with a `#[must_use]`
attribute, suggesting to remove it.
`double_must_use` lints functions with a plain `#[must_use]`
attribute, but which return a type which is already `#[must_use]`,
so the attribute has no benefit.
`must_use_candidate` is a pedantic lint that lints functions and
methods that return some non-unit type that is not already
`#[must_use]` and suggests to add the annotation.
account for doc visibility
This fixes#4608.
Also I noticed that the lint failed to look at trait and impl items. There's a small bit of fallout in the code, too, but not enough to warrant its own commit.
changelog: check docs of trait items and impl items, also make `missing_safety_doc` account for visibility
Fix false-positive of redundant_clone and move to clippy::perf
This PR introduces dataflow analysis to `redundant_clone` lint to filter out borrowed variables, which had been incorrectly detected.
Depends on https://github.com/rust-lang/rust/pull/64207.
changelog: Moved `redundant_clone` lint to `perf` group
# What this lint catches
## `clone`/`to_owned`
```rust
let s = String::new();
let t = s.clone();
```
```rust
// MIR
_1 = String::new();
_2 = &_1;
_3 = clone(_2); // (*)
```
We can turn this `clone` call into a move if
1. `_2` is the sole borrow of `_1` at the statement `(*)`
2. `_1` is not used hereafter
## `Deref` + type-specific `to_owned` method
```rust
let s = std::path::PathBuf::new();
let t = s.to_path_buf();
```
```rust
// MIR
_1 = PathBuf::new();
_2 = &1;
_3 = call deref(_2);
_4 = _3; // Copies borrow
StorageDead(_2);
_5 = Path::to_path_buf(_4); // (*)
```
We can turn this `to_path_buf` call into a move if
1. `_3` `_4` are the sole borrow of `_1` at `(*)`
2. `_1` is not used hereafter
# What this PR introduces
1. `MaybeStorageLive` that determines whether a local lives at a particular location
2. `PossibleBorrowerVisitor` that constructs [`TransitiveRelation`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_data_structures/transitive_relation/struct.TransitiveRelation.html) of possible borrows, e.g. visiting `_2 = &1; _3 = &_2:` will result in `_3 -> _2 -> _1` relation. Then `_3` and `_2` will be counted as possible borrowers of `_1` in the sole-borrow analysis above.
