…pty enum lint

…n` lint

The core issue was the usage of `reference_file_path.file_name()`, which
provided a non-existent path if the file to be updated was in a
subdirectory.

Instead we have to provide the whole path after 'tests/ui/' as the
'filename'. This part of the path is called `test_name` in the code now.

This should make the code slightly more understandable

fixes rust-lang#6522

changelog: field_reassign_with_default: don't expand macros in lint suggestion (rust-lang#6522)

Update CHANGELOG for Rust 1.50

changelog: none

r? `@flip1995`

field_reassign_with_default: don't expand macros in suggestion

fixes rust-lang#6522

changelog: field_reassign_with_default: don't expand macros in lint suggestion (rust-lang#6522)

Ensure `Copy` exception in trait definition for `wrong_self_conventio…

Add a test case to ensure `Copy` exception is preserved also in trait definition, when passing `self` by value.

Follow up of rust-lang#6316

changelog: none

Fix blessing of test output in subdirectories

The core issue was the usage of `reference_file_path.file_name()`, which
provided a non-existent path if the file to be updated was in a
subdirectory.

Instead we have to provide the whole path after 'tests/ui/' as the
'filename'. This part of the path is called `test_name` in the code now.

changelog: none

… enable/disable it particularly

This splits up clippy::collapsible_if into collapsible_if for
if x {
  if y { }
}
=>
if x && y { }

and collapsible_else_if for

if x {
} else {
 if y { }
}

=>
if x {

} else if y {

}

so that we can lint for only the latter but not the first if we desire.

changelog: collapsible_if: split up linting for if x {} else { if y {} } into collapsible_else_if lint

collapsible_if: split collapsible_else_if into its own lint so we can enable/disable it particularly

This splits up clippy::collapsible_if into collapsible_if for
if x {
  if y { }
}
=>
if x && y { }

and collapsible_else_if for

if x {
} else {
 if y { }
}

=>
if x {

} else if y {

}

so that we can lint for only the latter but not the first if we desire.

changelog: collapsible_if: split up linting for if x {} else { if y {} } into collapsible_else_if lint

Needless Question Mark Lint

Fixes rust-lang#6410, i.e the needless question mark lint

changelog: [`needless_question_mark`] New lint

Add ui-internal to cargo dev bless

changelog: internal

New lint: vec_init_then_push

fixes: rust-lang#1483

This will trigger on `new`, `default`, and `with_capacity` when the given capacity is less than or equal to the number of push calls. Is there anything else this should trigger on?

changelog: Added lint: `vec_init_then_push`

which checks for `as` casts between raw pointers
without changing its mutability
and suggest replacing it with `pointer::cast`.

Curse outdated test output

changelog: internal

Change `cargo dev bless` to only include test output that was generated since the last build of clippy. This is especially useful when running tests with `TESTNAME=...`. The feature may be disabled by `cargo dev bless --ignore-timestamp`.

…pe, r=flip1995

Fix: Empty enum never type suggested only if the feature is enabled

This PR addresses [Issue 6422](rust-lang/rust-clippy#6422). Instead of always recommending `never type` for empty enums, Clippy would only recommend [the lint](https://rust-lang.github.io/rust-clippy/master/index.html#empty_enum) if [LatePass.TyCtxt](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/context/struct.TyCtxt.html) has `features().never_type` enabled.

- \[ ] Followed [lint naming conventions][lint_naming]
- \[x] Added passing UI tests (including committed `.stderr` file)
- \[x] `cargo test` passes locally
- \[x] Executed `cargo dev update_lints`
- \[x] Added lint documentation
- \[x] Run `cargo dev fmt`
---

*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: Only trigger [`empty_enum`] lint if `never_type` feature is enabled.

Add a new lint `ptr_as_ptr`

This PR adds a new lint `ptr_as_ptr` which checks for `as` casts between raw pointers without changing its mutability and suggest replacing it with `pointer::cast`. Closes rust-lang#5890.

Open question: should this lint be `pedantic` or `style`? I set it `pedantic` for now because the original post suggests using it, but I think the lint also fits well to `style`.

---

changelog: New lint `ptr_as_ptr`

* Renames `sym.rs` to `sym_helper.rs` so that the `sym as rustc_sym` is no longer needed.
* Removes one needless `symbol` from a path

Tiny Symbol cleanup

* Renames `sym.rs` to `sym_helper.rs` so that the `sym as rustc_sym` is no longer needed.
* Removes one needless `symbol` from a path

changelog: none

…itance-self, r=Mark-Simulacrum"

This reverts commit b4def89, reversing
changes made to 7dc1e85.

An ICE happens when certain code is compiled in incremental compilation
mode and there are two `Ident`s that have the same `StableHash` value
but are considered different by `Eq` and `Hash`.

…cros, r=flip1995

Fix derive and macro related false positives in `field_reassign_with_default`

Closes rust-lang#6545

changelog: Fix derive and macro related false positives in [`field_reassign_with_default`]

Fix typo: `which which can be` -> `which can be`

Fixed a typo in the explanation of https://rust-lang.github.io/rust-clippy/master/index.html#large_types_passed_by_value : `which which can be` -> `which can be`

changelog: none

This changes the variable used for testing Clippy in the internal test
suite:

```
CLIPPY_TESTS -> __CLIPPY_INTERNAL_TESTS
```

`CLIPPY_TESTS` is understandably used in environments of Clippy users,
so we shouldn't use it in our test suite.

Fix typo: `irrevelent` -> `irrelevant`

changelog: none

add stuff on pointer::cast` to the document for `cast_ptr_alignment`
and fix line numbers in the test.

…_into, r=Manishearth

Reduce the span in `from_over_into` to impl header

A follow up of rust-lang/rust-clippy#6476 (comment)
> That item might be quite large. We may want to reduce the span to the `impl` header.

changelog: none

…earth

Internal lint symbol comparisons

changelog: none

* Added awareness of `rustc_span::symbol::kw::*` symbols.
* Compare with const symbols: `symbol.as_str() == "self"` => `symbol == kw::SelfLower`
* Don't compare symbols by string: `a.as_str() == b.as_str()` => `a == b`
* Lint comparing with `to_ident_string` or `to_string` instead of `Symbol::as_str`.

Fix FP for `boxed_local` lint in default trait fn impl

Fix FP on default trait function implementation on `boxed_local` lint.

Maybe I checked too much when looking if `self` is carrying `Self` in its bound type.
I can't find a good test case for this, so it could be too much conservative.
Let me know if you think only detecting `self` parameter is enough.

Fixes: rust-lang#4804

changelog: none

…ss_question_mark, r=phansch

Small fixes of doc in `needless_question_mark`

changelog: none

Change env var used for testing Clippy

This changes the variable used for testing Clippy in the internal test
suite:

```
CLIPPY_TESTS -> __CLIPPY_INTERNAL_TESTS
```

`CLIPPY_TESTS` is understandably used in environments of Clippy users,
so we shouldn't use it in our test suite.

changelog: Fix oversight which caused Clippy to lint deps in some environments.

Once again fixes rust-lang/rust-clippy#3874

…, r=phansch

Catch `pointer::cast` too in `cast_ptr_alignment`

Fixes rust-lang#4708

Although there were some discussion in the issue, this PR implements the original feature. I think `cast_ptr_alignment` should exist as it is, separated from `ptr_as_ptr`.

---

changelog: Extend `cast_ptr_alignment` lint for the `pointer::cast` method

…llercup,Manishearth,oli-obk,matthiaskrgr,phansch,mikerite,mcarton,yaahc,ebroto

Roadmap for 2021

[Rendered](https://github.com/flip1995/rust-clippy/blob/roadmap/doc/roadmap-2021.md)

This is the first time Clippy gets its own roadmap. The reason for this roadmap is, that with the Rust language growing, also Clippy is growing. With this keeping track of and implementing bigger projects gets quite hard. This roadmap should help in exactly this regard.

After having the approval of this roadmap by the Clippy team, we want to know from the community:

- What do you think in general about this roadmap?
- Are there any pain points in Clippy, that should be included here?
- What of the points listed here has the highest priority for you?

We're looking forward to getting your feedback!

changelog: Add roadmap for Clippy 2021

r? `@rust-lang/clippy`

This makes it possible to pass the `Impl` directly to functions, instead
of having to pass each of the many fields one at a time. It also
simplifies matches in many cases.

…nks, r=llogiq

Make a reference a link in doc

I think it's incovenient that references in doc are just a text.

changelog: none

Rework diagnostics for wrong number of generic args (fixes rust-lang#66228 and rust-lang#71924)

This PR reworks the `wrong number of {} arguments` message, so that it provides more details and contextual hints.

Reintroduce hir::ExprKind::If

Basically copied and paste rust-lang#59288/rust-lang/rust-clippy#4080 with some modifications.

The vast majority of tests were fixed and now there are only a few remaining. Since I am still unable to figure out the missing pieces, any help with the following list is welcome.

- [ ] **Unnecessary `typeck` exception**: [Cheated on this one to make CI green.](https://github.com/rust-lang/rust/pull/79328/files#diff-3faee9ba23fc54a12b7c43364ba81f8c5660045c7e1d7989a02a0cee1c5b2051)
- [x] **Incorrect span**: [Span should reference `then` and `else` separately.](https://github.com/rust-lang/rust/pull/79328/files#diff-cf2c46e82222ee4b1037a68fff8a1af3c4f1de7a6b3fd798aacbf3c0475abe3d)
- [x] **New note regarding `assert!`**: [Modified but not "wrong". Maybe can be a good thing?](https://github.com/rust-lang/rust/pull/79328/files#diff-9e0d7c89ed0224e2b62060c957177c27db43c30dfe3c2974cb6b5091cda9cfb5)
- [x] **Inverted report location**: [Modified but not "wrong". Locations were inverted.](https://github.com/rust-lang/rust/pull/79328/files#diff-f637ce7c1f68d523a165aa9651765df05e36c4d7d279194b1a6b28b48a323691)
- [x] **`src/test/ui/point-to-type-err-cause-on-impl-trait-return.rs` has weird errors**: [Not sure why this is happening.](https://github.com/rust-lang/rust/pull/79328/files#diff-c823c09660f5b112f95e97e8ff71f1797b6c7f37dbb3d16f8e98bbaea8072e95)
- [x] **Missing diagnostic**: [???](https://github.com/rust-lang/rust/pull/79328/files#diff-6b8ab09360d725ba4513933827f9796b42ff9522b0690f80b76de067143af2fc)

Rustup

r? `@ghost`

changelog: FP fix: [`needless_return`] no longer triggers inside macros.

- Don't ignore packaging `llvm/lib/` for `rust-dev` when LLVM is linked
statically
- Add `link-type.txt` so bootstrap knows whether llvm was linked
  statically or dynamically
- Don't assume CI LLVM is linked dynamically in `bootstrap::config`
- Fall back to dynamic linking if `link-type.txt` doesn't exist
- Fix existing bug that split the output of `llvm-config` on lines, not spaces
- Enable building LLVM tests

  This works around the following llvm bug:

  ```
  llvm-config: error: component libraries and shared library

  llvm-config: error: missing: /home/joshua/rustc2/build/x86_64-unknown-linux-gnu/llvm/build/lib/libgtest.a
  llvm-config: error: missing: /home/joshua/rustc2/build/x86_64-unknown-linux-gnu/llvm/build/lib/libgtest_main.a
  llvm-config: error: missing: /home/joshua/rustc2/build/x86_64-unknown-linux-gnu/llvm/build/lib/libLLVMTestingSupport.a
  thread 'main' panicked at 'command did not execute successfully: "/home/joshua/rustc2/build/x86_64-unknown-linux-gnu/llvm/build/bin/llvm-config" "--libfiles"
  ```

  I'm not sure why llvm-config thinks these are required, but to avoid
  the error, this builds them anyway.

- Temporarily set windows as the try builder. This should be reverted
  before merging.

- Bump version of `download-ci-llvm-stamp`

  `src/llvm-project` hasn't changed, but the generated tarball has.

- Only special case MacOS when dynamic linking. Static linking works fine.
- Store `link-type.txt` to the top-level of the tarball

  This allows writing the link type unconditionally. Previously, bootstrap
  had to keep track of whether the file IO *would* succeed (it would fail
  if `lib/` didn't exist), which was prone to bugs.

- Make `link-type.txt` required

  Anyone downloading this from CI should be using a version of bootstrap
  that matches the version of the uploaded artifacts. So a missing
  link-type indicates a bug in x.py.

... and update the comment in `config.toml.example`

Fixes rust-lang#81006

correctly deal with late-bound lifetimes in anon consts

adds support for using late bound lifetimes of the parent context in anon consts.
```rust
#![feature(const_generics)]
const fn inner<'a>() -> usize where &'a (): Sized { 3 }

fn test<'a>() {
    let _: [u8; inner::<'a>()];
}
```
The lifetime `'a` is late bound in `test` so it's not included in its generics but is instead dealt with separately in borrowck.
This didn't previously work for anon consts as they have to use the late bound lifetimes of their parent which has
to be explicitly handled.

r? `@matthewjasper` cc `@varkor` `@eddyb`

resolve: Reject ambiguity built-in attr vs different built-in attr

Fixes rust-lang#79798.

Resolution ensures that inert attributes cannot be used through imports like this, but built-in attributes don't go through initial resolution (only through resolution validation), so we have to keep some extra data (the built-in attribute name) to prevent it from happening.

…mbol, r=nikomatsakis`

Improve diagnostics when closure doesn't meet trait bound

Improves the diagnostics when closure doesn't meet trait bound by modifying `TypeckResuts::closure_kind_origins` such that `hir::Place` is used instead of `Symbol`. Using `hir::Place` to describe which capture influenced the decision of selecting a trait a closure satisfies to (Fn/FnMut/FnOnce, Copy) allows us to show precise path in the diagnostics when `capture_disjoint_field` feature is enabled.

Closes rust-lang/project-rfc-2229/issues/21

r? `@nikomatsakis`

… r=nikomatsakis

Allow Trait inheritance with cycles on associated types take 2

This reverts the revert of rust-lang#79209 and fixes the ICEs that's occasioned by that PR exposing some problems that are addressed in rust-lang#80648 and rust-lang#79811.
For easier review I'd say, check only the last commit, the first one is just a revert of the revert of rust-lang#79209 which was already approved.

This also could be considered part or the actual fix of rust-lang#79560 but I guess for that to be closed and fixed completely we would need to land rust-lang#80648 and rust-lang#79811 too.

r? `@nikomatsakis`
cc `@Aaron1011`

…ewjasper

resolve: Simplify collection of traits in scope

"Traits in scope" for a given location are collected by walking all scopes in type namespace, collecting traits in them and pruning traits that don't have an associated item with the given name and namespace.

Previously we tried to prune traits using some kind of hygienic resolution for associated items, but that was complex and likely incorrect, e.g. in rust-lang#80762 correction to visibilites of trait items caused some traits to not be in scope anymore.
I previously had some comments and concerns about this in rust-lang#65351.

In this PR we are doing some much simpler pruning based on `Symbol` and `Namespace` comparisons, it should be enough to throw away 99.9% of unnecessary traits.
It is not necessary for pruning to be precise because for trait aliases, for example, we don't do any pruning at all, and precise hygienic resolution for associated items needs to be done in typeck anyway.

The somewhat unexpected effect is that trait imports introduced by macros 2.0 now bring traits into scope due to the removed hygienic check on associated item names.
I'm not sure whether it is desirable or not, but I think it's acceptable for now.
The old check was certainly incorrect because macros 2.0 did bring trait aliases into scope.
If doing this is not desirable, then we should come up with some other way to avoid bringing traits from macros 2.0 into scope, that would accommodate for trait aliases as well.

---

The PR also contains a couple of pure refactorings
- Scope walk is done by using `visit_scopes` instead of a hand-rolled version.
- Code is restructured to accomodate for rustdoc that also wants to query traits in scope, but doesn't want to filter them by associated items at all.

r? `@matthewjasper`