[`missing_const_for_fn`]: Ensure dropped locals are `~const Destruct`
this will check every local for `TerminatorKind::Drop` to ensure they can be evaluated at compile time, not sure if this is the best way to do this but MIR is confusing and it works so...
fixes#10617
changelog: [`missing_const_for_fn`]: Ensure dropped locals are `~const Destruct`
Extend `explicit_iter_loop` and `explicit_into_iter_loop`
fixes#1518
Some included cleanups
* Split `for_loop` test into different files for each lint (partially).
* Move handling of some `into_iter` cases from `explicit_into_iter`.
---
changelog: Enhancement: [`explicit_iter_loop`]: Now also handles types that implement `IntoIterator`.
[#10416](https://github.com/rust-lang/rust-clippy/pull/10416)
changelog: Sugg: [`explicit_into_iter_loop`]: The suggestion now works on mutable references.
[#10416](https://github.com/rust-lang/rust-clippy/pull/10416)
<!-- changelog_checked -->
[`unnecessary_lazy_eval`]: don't lint on types with deref impl
Fixes#10437.
This PR changes clippy's util module `eager_or_lazy` to also consider deref expressions whose type has a non-builtin deref impl and not suggest replacing it as that might have observable side effects.
A prominent example might be the `lazy_static` macro, which creates a newtype with a `Deref` impl that you need to go through to get access to the inner value. Going from lazy to eager can make a difference there.
changelog: [`unnecessary_lazy_eval`]: don't lint on types with non-builtin deref impl
[`allow_attributes`, `allow_attributes_without_reason`]: Ignore attributes from procedural macros
I use `lint_reasons` and `clap`, which is a bit overzealous when it comes to preventing warnings in its macros; it uses a ton of allow attributes on everything to, as ironic as it is, silence warnings. These two now ignore anything from procedural macros.
PS, I think `allow_attributes.rs` should be merged with `attrs.rs` in the future.
fixes#10377
changelog: [`allow_attributes`, `allow_attributes_without_reason`]: Ignore attributes from procedural macros
move some strings into consts, more tests
s/missing_field_in_debug/missing_fields_in_debug
dont trigger in macro expansions
make dogfood tests happy
minor cleanups
replace HashSet with FxHashSet
replace match_def_path with match_type
if_chain -> let chains, fix markdown, allow newtype pattern
fmt
consider string literal in `.field()` calls as used
don't intern defined symbol, remove mentions of 'debug_tuple'
special-case PD, account for field access through `Deref`
Each of `{D,Subd}iagnosticMessage::{Str,Eager}` has a comment:
```
// FIXME(davidtwco): can a `Cow<'static, str>` be used here?
```
This commit answers that question in the affirmative. It's not the most
compelling change ever, but it might be worth merging.
This requires changing the `impl<'a> From<&'a str>` impls to `impl
From<&'static str>`, which involves a bunch of knock-on changes that
require/result in call sites being a little more precise about exactly
what kind of string they use to create errors, and not just `&str`. This
will result in fewer unnecessary allocations, though this will not have
any notable perf effects given that these are error paths.
Note that I was lazy within Clippy, using `to_string` in a few places to
preserve the existing string imprecision. I could have used `impl
Into<{D,Subd}iagnosticMessage>` in various places as is done in the
compiler, but that would have required changes to *many* call sites
(mostly changing `&format("...")` to `format!("...")`) which didn't seem
worthwhile.
[`default_constructed_unit_structs`]: do not lint on type alias paths
Fixes#10755.
Type aliases cannot be used as a constructor, so this lint should not trigger in those cases.
I also changed `clippy_utils::is_ty_alias` to also consider associated types since [they kinda are type aliases too](48ec50ae39/compiler/rustc_resolve/src/late/diagnostics.rs (L1520)).
changelog: [`default_constructed_unit_structs`]: do not lint on type alias paths
Add new lint `ptr_cast_constness`
This adds a new lint which functions as the opposite side of the coin to `ptr_as_ptr`. Rather than linting only as casts that don't change constness, this lints only constness; suggesting to use `pointer::cast_const` or `pointer::cast_mut` instead.
changelog: new lint [`ptr_cast_constness`]
* Don't consider expansions of different macros to be the same, even if they expand to the same tokens
* Don't consider `cfg!` expansions to be equal if they check different configs.
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
