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
Restrict `use_self` on nested items
Fixes#3637Fixes#3463
These changes make it so that nested items aren't visited any more by the `use_self` lint.
I think visiting nested items should be possible (so that it uses a different `item_path` for the nested item), but I'm not sure whether it's viable and what the best approach would be.
- Can `item_path` be changed to a new `Self` path before visiting the item, and then changing it back afterwards?
- Alternatively, could a new visitor be created, re-using `check_trait_method_impl_decl`?
Revert the random_state lint.
Remove the random_state lint until it or rustc has been fixed to no longer crash with debug assertions (see #3628)
We can't update clippy in the rustc repo because of this which is blocking nightlies because toolstate is already broken.
fixes#3628
Add run-rustfix where it already works
This PR adds `// run-rustfix` headers to tests for `MachineApplicable` lints where
applying the suggestions works without any errors.
Trigger `use_self` lint in local macros
Closes#2098
The test currently only covers local macros. #2098 suggested this:
> You could add the macro in question into the `mini_macro` subcrate
But that doesn't work for a `macro_rules`:
```
error: cannot export macro_rules! macros from a `proc-macro` crate type currently
```
So I suggest leaving out the test for external macros, as using `in_external_macro` seems straigtforward enough. Alternatives would be to use to add an additional crate (overkill if you ask me), or test with a `proc-macro`.
UI test cleanup: Extract lint from methods.rs test
Extracts the `result_map_unwrap_or_else` lint into a separate test file.
This also extracts the `IteratorFalsePositives` struct and impl into
`auxiliary/option_helpers.rs`.
cc #2038
Integrate rustfix into Clippy test suite
Once the [PR to compiletest-rs](https://github.com/laumann/compiletest-rs/pull/151) is reviewed and merged this fixes#2376.
I will create a separate tracking issue for adding `run-rustfix` to all tests.
Only trigger `infinite_iter` lint for infinitely allocating `collect()` calls
Fixes #3538
~Oh, I guess this should actually check other methods like `count` as well, not only `collect()`.~
Never mind, `collect` is the only of these functions that allocates a data structure.
Fix if_same_then_else false positive
This fixes false positive in #3559.
The problem was that `SpanlessEq` does not check patterns in declarations. So this two blocks considered equal.
```rust
if true {
let (x, y) = foo();
} else {
let (y, x) = foo();
}
```
Not sure if the proposed change is safe as `SpanlessEq` is used extensively in other lints, but I tried hard to come up with counterexample and failed.
Merge new_without_default_derive into new_without_default
Closes#3525, deprecating new_without_default_derive and moving both lints into new_without_default.
Teach `suspicious_else_formatting` about `if .. {..} {..}`
We essentially treat bare blocks `{..}` identically to `if .. {..}`, except for different lint messages.
Fixes#3044
There is no map_unit_fn.rs whose output would be diffed with map_unit_fn.stderr
map_unit_fn.stderr was renamed 8 months ago from option_map_unit_fn.stderr
but option_map_unit_fn.{stderr,rs} both remain and are in use.
Implements lint for order comparisons against bool (#3438)
As described on issue #3438, this change implements linting for `>` and `<` comparisons against both `boolean` literals and between expressions.
Adds lint for Vec<Box<T: Sized>>
This adds, and subsequently closes#3530. This is the first time I've ever worked with anything remotely close to internal Rust code, so I'm very much unsure about the if_chain! to figure this out!
I can't get rustfmt working on WSL with nightly 2018-12-07:
`error: component 'rustfmt' for target 'x86_64-unknown-linux-gnu' is unavailable for download`
Lint redundant clone of fields
Makes `redundant_clone` warn on unnecessary `foo.field.clone()` sometimes (it can detect an unnecessary clone only if the base of projection, `foo` in this case, is not used at all after that). This is enough for cases like `returns_tuple().0.clone()`.
Instead of searching for all the successive expressions after a vector
allocation, check only the first expression.
This is done to minimize the amount of false positives of the lint.
Add lint to detect slow zero-filled vector initialization. It detects
when a vector is zero-filled with extended with `repeat(0).take(len)`
or `resize(len, 0)`.
This zero-fillings are usually slower than simply using `vec![0; len]`.
3353: float support added for mistyped_literal_suffixes lint r=mikerite a=Maxgy
I implemented the mistyped_literal_suffixes lint for float literals.
```
#![allow(unused_variables)]
fn main() {
let x = 1E2_32;
let x = 75.22_64;
}
```
Given the above, the additional check suggests the variables to be written as `let x = 1E2_f32` and `let x = 75.22_f64`.
Fixes#3167
Co-authored-by: Maxwell Anderson <maxwell.brayden.anderson@gmail.com>
`possible_missing_comma` should only trigger when the binary operator has
unary equivalent. Otherwise, it's not possible to insert a comma without
breaking compilation. The operators identified were `+`, `&`, `*` and `-`.
This fixes the specific examples given in issues #3244 and #3396
but doesn't address the conflict this lint has with the style of starting
a line with a binary operator.
3397: UI test cleanup: Extract expect_fun_call tests r=matthiaskrgr a=phansch
Note that the new stderr file does not include a `shadow-unrelated`
error, because the new UI test file does not use `#![warn(clippy::all)]`
cc #2038
3398: UI test cleanup: Extract match_overlapping_arm tests r=matthiaskrgr a=phansch
cc #2038
Co-authored-by: Philipp Hansch <dev@phansch.net>
3217: Fix string_lit_as_bytes lint for macros r=phansch a=yaahallo
Prior to this change, string_lit_as_bytes would trigger for constructs
like `include_str!("filename").as_bytes()` and would recommend fixing it
by rewriting as `binclude_str!("filename")`.
This change updates the lint to act as an EarlyLintPass lint. It then
differentiates between string literals and macros that have bytes
yielding alternatives.
Closes#3205
3366: Don't expand macros in some suggestions r=oli-obk a=phansch
Fixes#1148Fixes#1628Fixes#2455Fixes#3023Fixes#3333Fixes#3360
Co-authored-by: Jane Lusby <jlusby42@gmail.com>
Co-authored-by: Philipp Hansch <dev@phansch.net>
Prior to this change, string_lit_as_bytes would trigger for constructs
like `include_str!("filename").as_bytes()` and would recommend fixing it
by rewriting as `binclude_str!("filename")`.
This change updates the lint to act as an EarlyLintPass lint. It then
differentiates between string literals and macros that have bytes
yielding alternatives.
Closes#3205
3355: Lint to remove redundant `clone()`s r=oli-obk a=sinkuu
This PR adds lint `redundant_clone`. It suggests to remove redundant `clone()` that clones a owned value that will be dropped without any usage after that.
Real-world example: https://github.com/rust-lang/rust/compare/7b0735a..sinkuu:redundant_clone2
Co-authored-by: Shotaro Yamada <sinkuu@sinkuu.xyz>
3331: Disable arithmetic lints in constant items r=oli-obk a=pengowen123
Currently this will not catch cases in associated constants. I'm not sure whether checking spans is the best way to solve this issue, but I don't think it will cause any problems.
Fixes#1858
Co-authored-by: Owen Sanchez <pengowen816@gmail.com>
3338: new_ret_no_self false positives r=flip1995 a=JoshMcguigan
~~WORK IN PROGRESS~~
I plan to fix all of the false positives in #3313 in this PR, but I wanted to open it now to start gathering feedback.
In this first commit, I've updated the lint to allow tuple return types as long as `Self` shows up at least once, in any position of the tuple. I believe this is the broadest possible interpretation of what should be allowed for tuple return types, but I would certainly be okay making the lint more strict.
fixes#3313
Co-authored-by: Josh Mcguigan <joshmcg88@gmail.com>
3350: Don't emit `new_without_default_derive` if an impl of Default exists regardless of generics r=oli-obk a=pengowen123
Fixes#2226
Co-authored-by: Owen Sanchez <pengowen816@gmail.com>
Boxes are a bit magic in that they need to use `*` to get an owned value
out of the box. They implement `Deref` but that only returns a
reference. This means an easy way to convert an `Option<Box<T>>` to an
`<Option<T>` is:
```
box_option.map(|b| *b)
```
However, since b36bb0a6 the `map_clone` lint is detecting this as an
attempt to copy the box. Fix by excluding boxes completely from the
deref part of this lint.
Fixes#3274
