refactor `AttributeGate` and `rustc_attr!` to emit notes during feature checking
First commit changes the following:
- `AttributeGate ` from an enum with (four) tuple fields to (five) named fields
- adds a `notes` fields that is emitted as notes in the `PostExpansionVisitor` pass
- removes the `this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date` note if the feature gate is `rustc_attrs`.
- various phrasing changes and touchups
- and finally, the reason why I went down this path to begin with: tell people they can use the diagnostic namespace when they hit the rustc_on_unimplemented feature gate 🙈
Second commit removes unused machinery for deprecated attributes
Add a new `mismatched-lifetime-syntaxes` lint
The lang-team [discussed this](https://hackmd.io/nf4ZUYd7Rp6rq-1svJZSaQ) and I attempted to [summarize](https://github.com/rust-lang/rust/pull/120808#issuecomment-2701863833) their decision. The summary-of-the-summary is:
- Using two different kinds of syntax for elided lifetimes is confusing. In rare cases, it may even [lead to unsound code](https://github.com/rust-lang/rust/issues/48686)! Some examples:
```rust
// Lint will warn about these
fn(v: ContainsLifetime) -> ContainsLifetime<'_>;
fn(&'static u8) -> &u8;
```
- Matching up references with no lifetime syntax, references with anonymous lifetime syntax, and paths with anonymous lifetime syntax is an exception to the simplest possible rule:
```rust
// Lint will not warn about these
fn(&u8) -> &'_ u8;
fn(&'_ u8) -> &u8;
fn(&u8) -> ContainsLifetime<'_>;
```
- Having a lint for consistent syntax of elided lifetimes will make the [future goal](https://github.com/rust-lang/rust/issues/91639) of warning-by-default for paths participating in elision much simpler.
---
This new lint attempts to accomplish the goal of enforcing consistent syntax. In the process, it supersedes and replaces the existing `elided-named-lifetimes` lint, which means it starts out life as warn-by-default.
Use `cfg_attr_trace` in AST with a placeholder attribute for accurate suggestion
In rust-lang/rust#138515, we insert a placeholder attribute so that checks for attributes can still know about the placement of `cfg` attributes. When we suggest removing items with `cfg_attr`s (fixrust-lang/rust#56328) and make them verbose. We tweak the wording of the existing "unused `extern crate`" lint.
```
warning: unused `extern crate`
--> $DIR/removing-extern-crate.rs:9:1
|
LL | extern crate removing_extern_crate as foo;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unused
|
note: the lint level is defined here
--> $DIR/removing-extern-crate.rs:6:9
|
LL | #![warn(rust_2018_idioms)]
| ^^^^^^^^^^^^^^^^
= note: `#[warn(unused_extern_crates)]` implied by `#[warn(rust_2018_idioms)]`
help: remove the unused `extern crate`
|
LL - #[cfg_attr(test, macro_use)]
LL - extern crate removing_extern_crate as foo;
|
```
r? `@petrochenkov`
try-job: x86_64-gnu-aux
PR 138515, we insert a placeholder attribute so that checks for attributes can still know about the placement of `cfg` attributes. When we suggest removing items with `cfg_attr`s (fix Issue 56328) and make them verbose. We tweak the wording of the existing "unused `extern crate`" lint.
```
warning: unused extern crate
--> $DIR/removing-extern-crate.rs:9:1
|
LL | extern crate removing_extern_crate as foo;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unused
|
note: the lint level is defined here
--> $DIR/removing-extern-crate.rs:6:9
|
LL | #![warn(rust_2018_idioms)]
| ^^^^^^^^^^^^^^^^
= note: `#[warn(unused_extern_crates)]` implied by `#[warn(rust_2018_idioms)]`
help: remove the unused `extern crate`
|
LL - #[cfg_attr(test, macro_use)]
LL - extern crate removing_extern_crate as foo;
LL +
|
```
Make two transmute-related MIR lints into HIR lint
Make `PTR_TO_INTEGER_TRANSMUTE_IN_CONSTS` (rust-lang/rust#130540) and `UNNECESSARY_TRANSMUTES` (rust-lang/rust#136083) into "normal" HIR-based lints.
Funny enough this came up in the review of the latter (https://github.com/rust-lang/rust/pull/136083#issuecomment-2614301413), but I guess it just was overlooked.
But anywyas, there's no reason for these to be MIR lints; in fact, it makes the suggestions for them a bit more complicated than necessary.
Note that there's probably a few more simplifications and improvements to be done here. Follow-ups can be done in a separate PR, especially if they're about the messaging and suggestions themselves, which I didn't write.
Improve `ambiguous_wide_pointer_comparisons` lint compare diagnostics
This PR improves the `ambiguous_wide_pointer_comparisons` lint compare diagnostics: `cmp`/`partial_cmp`, but also the operators `<`/`>`/`>=`/`<=`, by:
1. removing the reference to `std::ptr::addr_eq` which only works for equality
2. and adding an `#[expect]` suggestion for keeping the current behavior
Fixesrust-lang/rust#141510
Rollup of 7 pull requests
Successful merges:
- #140056 (Fix a wrong error message in 2024 edition)
- #140220 (Fix detection of main function if there are expressions around it)
- #140249 (Remove `weak` alias terminology)
- #140316 (Introduce `BoxMarker` to improve pretty-printing correctness)
- #140347 (ci: clean more disk space in codebuild)
- #140349 (ci: use aws codebuild for the `dist-x86_64-linux` job)
- #140379 (rustc-dev-guide subtree update)
r? `@ghost`
`@rustbot` modify labels: rollup
```
warning: cannot find macro `in_root` in the crate root
--> $DIR/key-value-expansion-scope.rs:1:10
|
LL | #![doc = in_root!()]
| ^^^^^^^ not found in the crate root
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #124535 <https://github.com/rust-lang/rust/issues/124535>
= help: import `macro_rules` with `use` to make it callable above its definition
= note: `#[warn(out_of_scope_macro_calls)]` on by default
```
Make the wasm_c_abi future compat warning a hard error
This is the next step in getting rid of the broken C abi for wasm32-unknown-unknown.
The lint was made deny-by-default in https://github.com/rust-lang/rust/pull/129534 3 months ago. This still keeps the `-Zwasm-c-abi` flag set to `legacy` by default. It will be flipped in a future PR.
cc https://github.com/rust-lang/rust/issues/122532
[AIX] Lint on structs that have a different alignment in AIX's C ABI
This PR adds a linting diagnostic on AIX for repr(C) structs that are required to follow
the power alignment rule. A repr(C) struct needs to follow the power alignment rule if
the struct:
- Has a floating-point data type (greater than 4-bytes) as its first member, or
- The first member of the struct is an aggregate, whose recursively first member is a
floating-point data type (greater than 4-bytes).
The power alignment rule for eligible structs is currently unimplemented, so a linting
diagnostic is produced when such a struct is encountered.
`CheckAttrVisitor::check_doc_keyword` checks `#[doc(keyword = "..")]`
attributes to ensure they are on an empty module, and that the value is
a non-empty identifier.
The `rustc::existing_doc_keyword` lint checks these attributes to ensure
that the value is the name of a keyword.
It's silly to have two different checking mechanisms for these
attributes. This commit does the following.
- Changes `check_doc_keyword` to check that the value is the name of a
keyword (avoiding the need for the identifier check, which removes a
dependency on `rustc_lexer`).
- Removes the lint.
- Updates tests accordingly.
There is one hack: the `SelfTy` FIXME case used to used to be handled by
disabling the lint, but now is handled with a special case in
`is_doc_keyword`. That hack will go away if/when the FIXME is fixed.
Co-Authored-By: Guillaume Gomez <guillaume1.gomez@gmail.com>
Add external macros specific diagnostics for check-cfg
This PR adds specific check-cfg diagnostics for unexpected cfg in external macros.
As well as hiding the some of the Cargo specific help/suggestions as they distraction for external macros and are generally not the right solution.
Follow-up to #132577
`@rustbot` label +L-unexpected_cfgs
r? compiler
