I refactored the code:
- Removed handling of methods, as it felt entirely unnecessary
- Removed clippy utils (obviously...)
- Used some shiny compiler features
(let-else is very handy for lints 👀)
- I also renamed the lint to `for_loop_over_fallibles` (note: no `s`).
I'm not sure what's the naming convention here, so maybe I'm wrong.
On later stages, the feature is already stable.
Result of running:
rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
Add warning against unexpected --cfg with --check-cfg
This PR adds a warning when an unexpected `--cfg` is specified but not in the specified list of `--check-cfg`.
This is the follow-up PR I mentioned in https://github.com/rust-lang/rust/pull/99519.
r? `@petrochenkov`
Uplift the `let_underscore` lints from clippy into rustc.
This PR resolves#97241.
This PR adds three lints from clippy--`let_underscore_drop`, `let_underscore_lock`, and `let_underscore_must_use`, which are meant to capture likely-incorrect uses of `let _ = ...` bindings (in particular, doing this on a type with a non-trivial `Drop` causes the `Drop` to occur immediately, instead of at the end of the scope. For a type like `MutexGuard`, this effectively releases the lock immediately, which is almost certainly the wrong behavior)
In porting the lints from clippy I had to copy over a bunch of utility functions from `clippy_util` that these lints also relied upon. Is that the right approach?
Note that I've set the `must_use` and `drop` lints to Allow by default and set `lock` to Deny by default (this matches the same settings that clippy has). In talking with `@estebank` he informed me to do a Crater run (I am not sure what type of Crater run to request here--I think it's just "check only"?)
On the linked issue, there's some discussion about using `must_use` and `Drop` together as a heuristic for when to warn--I did not implement this yet.
r? `@estebank`
Add `special_module_name` lint
Declaring `lib` as a module is one of the most common beginner mistakes when trying to setup a binary and library target in the same crate. `special_module_name` lints against it, as well as `mod main;`
```
warning: found module declaration for main.rs
--> $DIR/special_module_name.rs:4:1
|
LL | mod main;
| ^^^^^^^^^
|
= note: a binary crate cannot be used as library
warning: found module declaration for lib.rs
--> $DIR/special_module_name.rs:1:1
|
LL | mod lib;
| ^^^^^^^^
|
= note: `#[warn(special_module_name)]` on by default
= note: lib.rs is the root of this crate's library target
= help: to refer to it from other targets, use the library's name as the path
```
Note that the help message is not the best in that it doesn't provide an example of an import path (`the_actual_crate_name::`), and doesn't check whether the current file is part of a library/binary target to provide more specific error messages. I'm not sure where this lint would have to be run to access that information.
Streamline lint checking
The early (AST) and late (HIR) lint checkers have a number of functions that aren't used by rustc or clippy. Might as well remove them -- it's not like there's a canonical API here, as shown by the ad hoc use of `check_foo`/`check_foo_post` combinations.
r? `@cjgillot`
Some command-line options accessible through `sess.opts` are best
accessed through wrapper functions on `Session`, `TyCtxt` or otherwise,
rather than through field access on the option struct in the `Session`.
Adds a new lint which triggers on those options that should be accessed
through a wrapper function so that this is prohibited. Options are
annotated with a new attribute `rustc_lint_opt_deny_field_access` which
can specify the error message (i.e. "use this other function instead")
to be emitted.
A simpler alternative would be to simply rename the options in the
option type so that it is clear they should not be used, however this
doesn't prevent uses, just discourages them. Another alternative would
be to make the option fields private, and adding accessor functions on
the option types, however the wrapper functions sometimes rely on
additional state from `Session` or `TyCtxt` which wouldn't be available
in an function on the option type, so the accessor would simply make the
field available and its use would be discouraged too.
Signed-off-by: David Wood <david.wood@huawei.com>
Add a brief comment explaining why the diagnostic migration lints aren't
included in the `rustc::internal` diagnostic group.
Signed-off-by: David Wood <david.wood@huawei.com>
Introduce allow-by-default lints for checking whether diagnostics are
written in `SessionDiagnostic`/`AddSubdiagnostic` impls and whether
diagnostics are translatable. These lints can be denied for modules once
they are fully migrated to impls and translation.
Signed-off-by: David Wood <david.wood@huawei.com>
Similar to `let_underscore_drop`, this lint checks for statements similar
to `let _ = foo`, where `foo` is a lock guard. These types of let
statements are especially problematic because the lock gets released
immediately, instead of at the end of the scope. This behavior is almost
always the wrong thing.
This lint checks for statements similar to `let _ = foo`, where `foo` is
a type that implements `Drop`. These types of let statements cause the
expression in them to be dropped immediately, instead of at the end of
the scope. Such behavior can be surprizing, especially if you are
relying on the value to be dropped at the end of the scope. Instead, the
binding should be an underscore prefixed name (like `_unused`) or the
value should explicitly be passed to `std::mem::drop()` if the value
really should be dropped immediately.
Implement a lint to warn about unused macro rules
This implements a new lint to warn about unused macro rules (arms/matchers), similar to the `unused_macros` lint added by #41907 that warns about entire macros.
```rust
macro_rules! unused_empty {
(hello) => { println!("Hello, world!") };
() => { println!("empty") }; //~ ERROR: 1st rule of macro `unused_empty` is never used
}
fn main() {
unused_empty!(hello);
}
```
Builds upon #96149 and #96156.
Fixes#73576
Remove mutable_borrow_reservation_conflict lint and allow the code pattern
This was the only breaking issue with the NLL stabilization PR. Lang team decided to go ahead and allow this.
r? `@nikomatsakis`
Closes#59159Closes#56254
Use consistent function parameter order for early context construction and early linting
Rename some functions to make it clear that they do not necessarily work on the whole crate
Transition unsupported naked functions future incompatibility lint into
an error:
* Naked functions must contain a single inline assembly block.
Introduced as future incompatibility lint in 1.50 #79653.
Change into an error fixes a soundness issue described in #32489.
* Naked functions must not use any forms of inline attribute.
Introduced as future incompatibility lint in 1.56 #87652.
