Now that `if let` chains have been introduced, the `if_chain` external
crate is no longer necessary. Dropping special support for it also
alleviates the need to keep the crate as a dependency in tests.
This is a cleanup PR.
changelog: none
base check
same fields different struct
reordered fields
different paths to the same struct
same for tuple structs
style: use `zip`-the-function all over the place
makes the code a bit more concise by removing the need for explicit
`.iter()`
style: move precondition checking to the match guard
the match arms above put the "sanity" checks in the guard, and call only
`check_pat` in the body. With this commit, the (tuple) struct cases
follow that convention as well. Well, almost -- I think the ident check
belongs to the second category of checks, so I put it in the body as
well
misc: use `None` in the pattern directly
this'll probably be marginally faster thanks to the equality check being
now structural
move the tests to the right file
When an expression is made of a `!` or `-` unary operator which does not
change the type of the expression, use a new variant in `Sugg` to denote
it. This allows replacing an extra application of the same operator by
the removal of the original operator instead.
Some suggestions will now be shown as `x` instead of `!!x`. Right now,
no suggestion seems to produce `--x`.
changelog: none
When an expression is made of a `!` or `-` unary operator which does not
change the type of the expression, use a new variant in `Sugg` to denote
it. This allows replacing an extra application of the same operator by
the removal of the original operator instead.
Also, when adding a unary operator to a suggestion, do not enclose the
operator argument in parentheses if it starts with a unary operator
itself unless it is a binary operation (including `as`), because in this
case parentheses are required to not bind the lhs only.
Some suggestions will now be shown as `x` instead of `!!x`. Right now,
no suggestion seems to produce `--x`.
Now that `if let` chains have been introduced, the `if_chain` external
crate is no longer necessary. Dropping special support for it also
alleviates the need to keep the crate as a dependency in tests.
The useless_attribute lint was incorrectly flagging #[expect(redundant_imports)]
as useless when applied to macro re-exports. This occurred because the lint
didn't recognize 'redundant_imports' as a valid rustc lint name.
This commit:
- Adds 'redundant_imports' to the list of known rustc lints in sym.rs
- Updates the useless_attribute lint to properly handle this case
- Adds a regression test to prevent future false positives
There are many places that join path segments with `::` to produce a
string. A lot of these use `join("::")`. Many in rustdoc use
`join_with_double_colon`, and a few use `.joined("..")`. One in Clippy
uses `itertools::join`. A couple of them look for `kw::PathRoot` in the
first segment, which can be important.
This commit introduces `rustc_ast::join_path_{syms,ident}` to do the
joining for everyone. `rustc_ast` is as good a location for these as
any, being the earliest-running of the several crates with a `Path`
type. Two functions are needed because `Ident` printing is more complex
than simple `Symbol` printing.
The commit also removes `join_with_double_colon`, and
`estimate_item_path_byte_length` with it.
There are still a handful of places that join strings with "::" that are
unchanged. They are not that important: some of them are in tests, and
some of them first split a path around "::" and then rejoin with "::".
This fixes one test case where `{{root}}` shows up in an error message.
Fix several issues with `manual_is_multiple_of`
- `&a % &b == 0` compiles, but requires dereferencing `b` when replacing
with `a.is_multiple_of(b)`.
- In `a % b == 0`, if type of `a` is not certain, `a.is_multiple_of(b)`
might not be typable.
- In `a % b == 0`, `a` and `b` must be unsigned integers, not any
arbitrary types implementing `Rem` and outputing an integer.
Those fixes have required increasing the precision of type certainty
determination in the two first patches.
Fixesrust-lang/rust-clippy#15203Fixesrust-lang/rust-clippy#15204
changelog: [`manual_is_multiple_of`]: fix various false positive
de-duplicate condition scoping logic between AST→HIR lowering and `ScopeTree` construction
There was some overlap between `rustc_ast_lowering::LoweringContext::lower_cond` and `rustc_hir_analysis::check::region::resolve_expr`, so I've removed the former and migrated its logic to the latter, with some simplifications.
Consequences:
- For `while` and `if` expressions' `let`-chains, this changes the `HirId`s for the `&&`s to properly correspond to their AST nodes. This is how guards were handled already.
- This makes match guards share previously-duplicated logic with `if`/`while` expressions. This will also be used by guard pattern[^1] guards.
- Aside from legacy syntax extensions (e.g. some builtin macros) that directly feed AST to the compiler, it's currently impossible to put attributes directly on `&&` operators in `let` chains[^2]. Nonetheless, attributes on `&&` operators in `let` chains in `if`/`while` expression conditions are no longer silently ignored and will be lowered.
- This no longer wraps conditions in `DropTemps`, so the HIR and THIR will be slightly smaller.
- `DesugaringKind::CondTemporary` is now gone. It's no longer applied to any spans, and all uses of it were dead since they were made to account for `if` and `while` being desugared to `match` on a boolean scrutinee.
- Should be a marginal perf improvement beyond that due to leveraging [`ScopeTree` construction](5e749eb66f/compiler/rustc_hir_analysis/src/check/region.rs (L312-L355))'s clever handling of `&&` and `||`:
- This removes some unnecessary terminating scopes that were placed around top-level `&&` and `||` operators in conditions. When lowered to MIR, logical operator chains don't create intermediate boolean temporaries, so there's no temporary to drop. The linked snippet handles wrapping the operands in terminating scopes as necessary, in case they create temporaries.
- The linked snippet takes care of letting `let` temporaries live and terminating other operands, so we don't need separate traversals of `&&` chains for that.
[^1]: rust-lang/rust#129967
[^2]: Case-by-case, here's my justification: `#[attr] e1 && e2` applies the attribute to `e1`. In `#[attr] (e1 && e2)` , the attribute is on the parentheses in the AST, plus it'd fail to parse if `e1` or `e2` contains a `let`. In `#[attr] expands_to_let_chain!()`, the attribute would already be ignored (rust-lang/rust#63221) and it'd fail to parse anyway; even if the expansion site is a condition, the expansion wouldn't be parsed with `Restrictions::ALLOW_LET`. If it *was* allowed, the notion of a "reparse context" from https://github.com/rust-lang/rust/issues/61733#issuecomment-509626449 would be necessary in order to make `let`-chains left-associative; multiple places in the compiler assume they are.
fix: Include frontmatter in -Zunpretty output
In the implementation (rust-lang/rust#140035), this was left as an open question for
the tracking issue (rust-lang/rust#136889). My assumption is that this should be
carried over.
The test was carried over from rust-lang/rust#137193 which was superseded by rust-lang/rust#140035.
Thankfully, either way, `-Zunpretty` is unstable and we can always
change it even if we stabilize frontmatter.
<strike>blocked on rust-lang/rust-clippy#15073</strike>
Lint method calls inside `map_or` too, so for this, lint will be showed:
```rust
Some(4).map_or("asd".to_string().len() as i32, f);
```
previously it worked only for:
```rust
Some(4).map_or(slow_fun(), f);
```
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2024&gist=bfcda42a6af446e69bc883a8b45eb13c
Sorry for multiple `or_fun_call` PRs.
changelog: [`or_fun_call`]: lint method calls inside map_or first arg
Allow custom default address spaces and parse `p-` specifications in the datalayout string
Some targets, such as CHERI, use as default an address space different from the "normal" default address space `0` (in the case of CHERI, [200 is used](https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-877.pdf)). Currently, `rustc` does not allow to specify custom address spaces and does not take into consideration [`p-` specifications in the datalayout string](https://llvm.org/docs/LangRef.html#langref-datalayout).
This patch tries to mitigate these problems by allowing targets to define a custom default address space (while keeping the default value to address space `0`) and adding the code to parse the `p-` specifications in `rustc_abi`. The main changes are that `TargetDataLayout` now uses functions to refer to pointer-related informations, instead of having specific fields for the size and alignment of pointers in the default address space; furthermore, the two `pointer_size` and `pointer_align` fields in `TargetDataLayout` are replaced with an `FxHashMap` that holds info for all the possible address spaces, as parsed by the `p-` specifications.
The potential performance drawbacks of not having ad-hoc fields for the default address space will be tested in this PR's CI run.
r? workingjubilee
compiler: rename BareFn to FnPtr
At some point "BareFn" was the chosen name for a "bare" function, without the niceties of `~fn`, `&fn`, or a few other ways of writing a function type. However, at some point the syntax for a "bare function" and any other function diverged even more. We started calling them what they are: function pointers, denoted by their own syntax.
However, we never changed the *internal* name for these, as this divergence was very gradual. Personally, I have repeatedly searched for "FnPtr" and gotten confused until I find the name is BareFn, only to forget this until the next time, since I don't routinely interact with the higher-level AST and HIR. But even tools that interact with these internal types only touch on them in a few places, making a migration easy enough. Let's use a more intuitive and obvious name, as this 12+ year old name has little to do with current Rust.
The `TyCtxt::hir_get_fn_id_for_return_block()` function was too broad,
as it will return positively even when given part of an expression that
can be used as a return value. A new
`potential_return_of_enclosing_body()` utility function has been made to
represent the fact that an expression might be directly returned from
its enclosing body.
changelog: [`return_and_then`]: prevent false positives in case of a
partially used expression
Fixesrust-lang/rust-clippy#15111Fixesrust-lang/rust-clippy#14927
<!-- TRIAGEBOT_START -->
<!-- TRIAGEBOT_SUMMARY_START -->
### Summary Notes
-
[Beta-nomination](https://github.com/rust-lang/rust-clippy/pull/15115#issuecomment-2996222332)
by [samueltardieu](https://github.com/samueltardieu)
*Managed by `@rustbot`—see
[help](https://forge.rust-lang.org/triagebot/note.html) for details*
<!-- TRIAGEBOT_SUMMARY_END -->
<!-- TRIAGEBOT_END -->
Fixes: rust-lang/rust-clippy#14897, rust-lang/rust-clippy#10015
This is not a perfect solution, but it fixes the issue. Happy to discuss
further with the clippy team.
This PR refines check_mul_add to avoid false positives on ambiguous
float types (e.g., f32 vs f64). It improves type detection and ensures
mul_add is only suggested when the type is clear.
Changes:
- Improved detection of ambiguous float types
- Refined mul_add suggestion logic
- Added tests for ambiguous cases
## Example
Before this change, expressions like:
```rust
let x = 1.0; // ambiguous type
let _ = x * 2.0 + 0.5; // could incorrectly suggest mul_add
```
----
changelog: [`suboptimal_flops`]: improve handling of ambiguous float
types in mul_add suggestions
