Add initial version of const_fn lint
This adds an initial version of a lint that can tell if a function could be `const`.
TODO:
- [x] Finish up the docs
- [x] Fix the ICE
cc #2440
Prevent incorrect cast_lossless suggestion in const_fn
`::from` is not a const fn, so applying the suggestion of
`cast_lossless` would fail to compile. The fix is to skip the lint if
the cast is found inside a const fn.
Fixes#3656
`::from` is not a const fn, so applying the suggestion of
`cast_lossless` would fail to compile. The fix is to skip the lint if
the cast is found inside a const fn.
* master: (58 commits)
Rustfmt all the things
Don't make decisions on values that don't represent the decision
Improving comments.
Rustup
Added rustfix to the test.
Improve span shortening.
Added "make_return" and "blockify" convenience methods in Sugg and used them in "needless_bool".
Actually check for constants.
Fixed potential mistakes with nesting. Added tests.
formatting fix
Update clippy_lints/src/needless_bool.rs
formatting fix
Fixing typo in CONTRIBUTING.md
Fix breakage due to rust-lang/rust#57651
needless bool lint suggestion is wrapped in brackets if it is an "else" clause of an "if-else" statement
Fix automatic suggestion on `use_self`.
Remove negative integer literal checks.
Fix `implicit_return` false positives.
Run rustfmt
Fixed breakage due to rust-lang/rust#57489
...
Fix automatic suggestion on `use_self`.
In an example like this:
```rust
impl Example {
fn fun_1() { }
fn fun_2() {
Example::fun_1();
}
}
```
Clippy tries to replace `Example::fun_1` with `Self`, loosing `::fun_1` in the process, it should rather try to replace `Example` with `Self`.
**Question**
- There may be other paths that need the same treatment, but I'm not sure I understand them fully:
- e648adf086/clippy_lints/src/use_self.rs (L94-L96)
- e648adf086/clippy_lints/src/use_self.rs (L225-L229)
Fix `implicit_return` false positives.
Fixes the following false positives:
- linting on `if let` without `else` in a `loop` even with a present `return`
- linting on `unreachable!()`
Catch up with `format_args` change
Catches up with a change in rust-lang/rust#57537. (Since the optimization is optional, this clippy PR can be merged before the rustc PR.)
Happened to fix a bug in `expect_fun_call`, that is the lint ignores more than
one arguments to `format`.
```
warning: use of `expect` followed by a function call
--> src/main.rs:2:17
|
2 | Some("foo").expect(format!("{} {}", 1, 2).as_ref());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| panic!("{} {}", 1))`
|
```
Catches up with a change in rust-lang/rust#57537
Happened to fix a bug in `expect_fun_call`, that is the lint ignores more than
one arguments to `format`.
`cloned` requires that the elements of the iterator must be references. This
change determines if that is the case by examining the type of the closure
argument and suggesting `.cloned` only if it is a reference. When the closure
argument is not a reference, it suggests removing the `map` call instead.
A minor problem with this change is that the new check sometimes overlaps
with the `clone_on_copy` lint.
Fixes#498
