Extend `unused_must_use` to cover block exprs
Given code like
```rust
#[must_use]
fn foo() -> i32 {
42
}
fn warns() {
{
foo();
}
}
fn does_not_warn() {
{
foo()
};
}
fn main() {
warns();
does_not_warn();
}
```
### Before This PR
```
warning: unused return value of `foo` that must be used
--> test.rs:8:9
|
8 | foo();
| ^^^^^
|
= note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
|
8 | let _ = foo();
| +++++++
warning: 1 warning emitted
```
### After This PR
```
warning: unused return value of `foo` that must be used
--> test.rs:8:9
|
8 | foo();
| ^^^^^
|
= note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
|
8 | let _ = foo();
| +++++++
warning: unused return value of `foo` that must be used
--> test.rs:14:9
|
14 | foo()
| ^^^^^
|
help: use `let _ = ...` to ignore the resulting value
|
14 | let _ = foo();
| +++++++ +
warning: 2 warnings emitted
```
Fixes#104253.
This commit reverts a change made in #111425.
It was believed that this change was necessary for implementing type privacy lints, but #111801 showed that it was not necessary.
Quite opposite, the revert fixes some issues.
This is apparently where it's busting stack, and the comments for `ensure_sufficient_stack` say that
> E.g. almost any call to visit_expr or equivalent can benefit from this.
Uplift `clippy::cmp_nan` lint
This PR aims at uplifting the `clippy::cmp_nan` lint into rustc.
## `invalid_nan_comparisons`
~~(deny-by-default)~~ (warn-by-default)
The `invalid_nan_comparisons` lint checks comparison with `f32::NAN` or `f64::NAN` as one of the operand.
### Example
```rust,compile_fail
let a = 2.3f32;
if a == f32::NAN {}
```
### Explanation
NaN does not compare meaningfully to anything – not even itself – so those comparisons are always false.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
Rollup of 3 pull requests
Successful merges:
- #112260 (Improve document of `unsafe_code` lint)
- #112429 ([rustdoc] List matching impls on type aliases)
- #112442 (Deduplicate identical region constraints in new solver)
r? `@ghost`
`@rustbot` modify labels: rollup
Uplift `clippy::undropped_manually_drops` lint
This PR aims at uplifting the `clippy::undropped_manually_drops` lint.
## `undropped_manually_drops`
(warn-by-default)
The `undropped_manually_drops` lint check for calls to `std::mem::drop` with a value of `std::mem::ManuallyDrop` which doesn't drop.
### Example
```rust
struct S;
drop(std::mem::ManuallyDrop::new(S));
```
### Explanation
`ManuallyDrop` does not drop it's inner value so calling `std::mem::drop` will not drop the inner value of the `ManuallyDrop` either.
-----
Mostly followed the instructions for uplifting an clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
-----
For Clippy:
changelog: Moves: Uplifted `clippy::undropped_manually_drops` into rustc
Extra context for unreachable_pub lint
While experienced Rustaceans no doubt know this sort of thing already, as more of a newbie I had trouble understanding why I was triggering the lint. Hopefully this expanded explanation saves someone else some head-scratching.
Fixes#110922
Uplift `clippy::invalid_utf8_in_unchecked` lint
This PR aims at uplifting the `clippy::invalid_utf8_in_unchecked` lint into two lints.
## `invalid_from_utf8_unchecked`
(deny-by-default)
The `invalid_from_utf8_unchecked` lint checks for calls to `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut` with an invalid UTF-8 literal.
### Example
```rust
unsafe {
std::str::from_utf8_unchecked(b"cl\x82ippy");
}
```
### Explanation
Creating such a `str` would result in undefined behavior as per documentation for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.
## `invalid_from_utf8`
(warn-by-default)
The `invalid_from_utf8` lint checks for calls to `std::str::from_utf8` and `std::str::from_utf8_mut` with an invalid UTF-8 literal.
### Example
```rust
std::str::from_utf8(b"ru\x82st");
```
### Explanation
Trying to create such a `str` would always return an error as per documentation for `std::str::from_utf8` and `std::str::from_utf8_mut`.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
````@rustbot```` label: +I-lang-nominated
r? compiler
-----
For Clippy:
changelog: Moves: Uplifted `clippy::invalid_utf8_in_unchecked` into rustc
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most
compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl
From<&'static str>`, which involves a bunch of knock-on changes that
require/result in call sites being a little more precise about exactly
what kind of string they use to create errors, and not just `&str`. This
will result in fewer unnecessary allocations, though this will not have
any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to
preserve the existing string imprecision. I could have used `impl
Into<{D,Subd}iagnosticMessage>` in various places as is done in the
compiler, but that would have required changes to *many* call sites
(mostly changing `&format("...")` to `format!("...")`) which didn't seem
worthwhile.
Add warn-by-default lint when local binding shadows exported glob re-export item
This PR introduces a warn-by-default rustc lint for when a local binding (a use statement, or a type declaration) produces a name which shadows an exported glob re-export item, causing the name from the exported glob re-export to be hidden (see #111336).
### Unresolved Questions
- [x] ~~Is this approach correct? While it passes the UI tests, I'm not entirely convinced it is correct.~~ Seems to be ok now.
- [x] ~~What should the lint be called / how should it be worded? I don't like calling `use x::*;` or `struct Foo;` a "local binding" but they are `NameBinding`s internally if I'm not mistaken.~~ ~~The lint is called `local_binding_shadows_glob_reexport` for now, unless a better name is suggested.~~ `hidden_glob_reexports`.
Fixes#111336.
Ensure Fluent messages are in alphabetical order
Fixes#111847
This adds a tidy check to ensure Fluent messages are in alphabetical order, as well as sorting all existing messages. I think the error could be worded better, would appreciate suggestions.
<details>
<summary>Script used to sort files</summary>
```py
import sys
import re
fn = sys.argv[1]
with open(fn, 'r') as f:
data = f.read().split("\n")
chunks = []
cur = ""
for line in data:
if re.match(r"^([a-zA-Z0-9_]+)\s*=\s*", line):
chunks.append(cur)
cur = ""
cur += line + "\n"
chunks.append(cur)
chunks.sort()
with open(fn, 'w') as f:
f.write(''.join(chunks).strip("\n\n") + "\n")
```
</details>
Consider lint check attributes on match arms
Currently, lint check attributes on match arms have no effect for some lints. This PR makes some lint passes to take those attributes into account.
- `LateContextAndPass` for late lint doesn't update `last_node_with_lint_attrs` when it visits match arms. This leads to lint check attributes on match arms taking no effects on late lints that operate on the arms' pattern:
```rust
match value {
#[deny(non_snake_case)]
PAT => {} // `non_snake_case` only warned due to default lint level
}
```
To be honest, I'm not sure whether this is intentional or just an oversight. I've dug the implementation history and searched up issues/PRs but couldn't find any discussion on this.
- `MatchVisitor` doesn't update its lint level when it visits match arms. This leads to check lint attributes on match arms taking no effect on some lints handled by this visitor, namely: `bindings_with_variant_name` and `irrefutable_let_patterns`.
This seems to be a fallout from #108504. Before 05082f57af, when the visitor operated on HIR rather than THIR, check lint attributes for the said lints were effective. [This playground][play] compiles successfully on current stable (1.69) but fails on current beta and nightly.
I wasn't sure where best to place the test for this. Let me know if there's a better place.
[play]: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=38432b79e535cb175f8f7d6d236d29c3
[play-match]: https://play.rust-lang.org/?version=beta&mode=debug&edition=2021&gist=629aa71b7c84b269beadeba664e2221d
Dont check `must_use` on nested `impl Future` from fn
Fixes (but does not close, per beta policy) #111484
Also fixes a `FIXME` left in the code about (presumably) false-positives on non-async `#[must_use] fn() -> impl Future` cases, though if that's not desirable to include in the beta backport then I can certainly revert it.
Beta nominating as it fixes a beta ICE.
Document that `missing_copy_implementations` and `missing_debug_implementations` only apply to public items.
I encountered #111359 (fixed) and noticed that the documentation didn't say that it was _intended_ that `missing_debug_implementations` only applies to public items. This PR fixes that, and makes the same wording change to `missing_copy_implementations` which has the same condition.
I chose the words to also be similar to `missing_docs` which already had such a remark.
Introduce `DynSend` and `DynSync` auto trait for parallel compiler
part of parallel-rustc #101566
This PR introduces `DynSend / DynSync` trait and `FromDyn / IntoDyn` structure in rustc_data_structure::marker. `FromDyn` can dynamically check data structures for thread safety when switching to parallel environments (such as calling `par_for_each_in`). This happens only when `-Z threads > 1` so it doesn't affect single-threaded mode's compile efficiency.
r? `@cjgillot`
Uplift `clippy::{drop,forget}_{ref,copy}` lints
This PR aims at uplifting the `clippy::drop_ref`, `clippy::drop_copy`, `clippy::forget_ref` and `clippy::forget_copy` lints.
Those lints are/were declared in the correctness category of clippy because they lint on useless and most probably is not what the developer wanted.
## `drop_ref` and `forget_ref`
The `drop_ref` and `forget_ref` lint checks for calls to `std::mem::drop` or `std::mem::forget` with a reference instead of an owned value.
### Example
```rust
let mut lock_guard = mutex.lock();
std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
// still locked
operation_that_requires_mutex_to_be_unlocked();
```
### Explanation
Calling `drop` or `forget` on a reference will only drop the reference itself, which is a no-op. It will not call the `drop` or `forget` method on the underlying referenced value, which is likely what was intended.
## `drop_copy` and `forget_copy`
The `drop_copy` and `forget_copy` lint checks for calls to `std::mem::forget` or `std::mem::drop` with a value that derives the Copy trait.
### Example
```rust
let x: i32 = 42; // i32 implements Copy
std::mem::forget(x) // A copy of x is passed to the function, leaving the
// original unaffected
```
### Explanation
Calling `std::mem::forget` [does nothing for types that implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the value will be copied and moved into the function on invocation.
-----
Followed the instructions for uplift a clippy describe here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
cc `@m-ou-se` (as T-libs-api leader because the uplifting was discussed in a recent meeting)
While experienced Rustaceans no doubt know this sort of thing already, as more of a newbie I had trouble understanding why I was triggering the lint.
Hopefully this expanded explanation saves someone else some head-scratching.
Introduce `AliasKind::Inherent` for inherent associated types
Allows us to check (possibly generic) inherent associated types for well-formedness.
Type inference now also works properly.
Follow-up to #105961. Supersedes #108430.
Fixes#106722.
Fixes#108957.
Fixes#109768.
Fixes#109789.
Fixes#109790.
~Not to be merged before #108860 (`AliasKind::Weak`).~
CC `@jackh726`
r? `@compiler-errors`
`@rustbot` label T-types F-inherent_associated_types
Emit while_true lint spanning the entire loop condition
The lint that suggests `loop {}` instead of `while true {}` has functionality to 'pierce' parenthesis in cases like `while (true) {}`. In these cases, the emitted span only went to the hi of the `true` itself, not spanning the entire loop condition.
Before:
```
warning: denote infinite loops with `loop { ... }`
--> /tmp/foobar.rs:2:5
|
2 | while ((((((true)))))) {}
| ^^^^^^^^^^^^^^^^ help: use `loop`
|
= note: `#[warn(while_true)]` on by default
```
After:
```
warning: denote infinite loops with `loop { ... }`
--> /tmp/foobar.rs:2:5
|
2 | while ((((((true)))))) {}
| ^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
|
= note: `#[warn(while_true)]` on by default
```
This is especially a problem for rustfix.
added TraitAlias to check_item() for missing_docs
As in issue #111025 the `missing_docs` was not being triggered for trait aliases. I added `TraitAlias` to the pattern match for check_item(), and the lint seems to be behaving appropriately
The lint that suggests `loop {}` instead of `while true {}` has functionality to 'pierce' parenthesis
in cases like `while (true) {}`. In these cases, the emitted span only went to the hi of the `true`
itself, not spanning the entire loop condition.
Before:
```
warning: denote infinite loops with `loop { ... }`
--> /tmp/foobar.rs:2:5
|
2 | while ((((((true)))))) {}
| ^^^^^^^^^^^^^^^^ help: use `loop`
|
= note: `#[warn(while_true)]` on by default
```
After:
```
warning: denote infinite loops with `loop { ... }`
--> /tmp/foobar.rs:2:5
|
2 | while ((((((true)))))) {}
| ^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
|
= note: `#[warn(while_true)]` on by default
```
This is done to simplify to relationship between names() and values()
but also make thing clearer (having an Any to represent that any values
are allowed) but also to allow the (none) + values expected cases that
wasn't possible before.
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
Add lint to deny diagnostics composed of static strings
r? ghost
I'm hoping to have a lint that semi-automatically converts simple diagnostics such as `struct_span_err(span, "msg").help("msg").span_note(span2, "msg").emit()` to typed session diagnostics. It's quite hacky and not entirely working because of problems with `x fix` but should hopefully help reduce some of the work.
I'm going to start trying to apply what I can from this, but opening this as a draft in case anyone wants to develop on it.
cc #100717
Switch to `EarlyBinder` for `explicit_item_bounds`
Part of the work to finish https://github.com/rust-lang/rust/issues/105779.
This PR adds `EarlyBinder` to the return type of the `explicit_item_bounds` query and removes `bound_explicit_item_bounds`.
r? `@compiler-errors` (hope it's okay to request you, since you reviewed #110299 and #110498😃)
fix lint regression in `non_upper_case_globals`
Fixes#110573
The issue also exists for inherent associated types (where I copied my impl from). `EarlyContext` is more involved to fix in this way, so I'll leave it be for now (note it's unstable so that's not urgent).
r? `@compiler-errors`
Add `rustc_fluent_macro` to decouple fluent from `rustc_macros`
Fluent, with all the icu4x it brings in, takes quite some time to compile. `fluent_messages!` is only needed in further downstream rustc crates, but is blocking more upstream crates like `rustc_index`. By splitting it out, we allow `rustc_macros` to be compiled earlier, which speeds up `x check compiler` by about 5 seconds (and even more after the needless dependency on `serde_json` is removed from `rustc_data_structures`).
Fluent, with all the icu4x it brings in, takes quite some time to
compile. `fluent_messages!` is only needed in further downstream rustc
crates, but is blocking more upstream crates like `rustc_index`. By
splitting it out, we allow `rustc_macros` to be compiled earlier, which
speeds up `x check compiler` by about 5 seconds (and even more after the
needless dependency on `serde_json` is removed from
`rustc_data_structures`).
