This commit modifies the `substitute_normalize_and_test_predicates`
query, renaming it to `impossible_predicates` and only checking
predicates which do not require substs. By making this change,
polymorphization doesn't have to explicitly support vtables.
Signed-off-by: David Wood <david@davidtw.co>
Ignore not really redundant clones of ManuallyDrop
"Redundant" clones of `ManuallyDrop` are sometimes used for the side effect of
invoking the clone, without running the drop implementation of the inner type.
In other words, they aren't really redundant. For example, futures-rs crate:
```rust
#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant.
unsafe fn increase_refcount<T: ArcWake>(data: *const ()) {
// Retain Arc, but don't touch refcount by wrapping in ManuallyDrop
let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
// Now increase refcount, but don't drop new refcount either
let _arc_clone: mem::ManuallyDrop<_> = arc.clone();
}
```
changelog: Ignore redundant clone lint for ManuallyDrop.
"Redundant" clones of `ManuallyDrop` are sometimes used for the side effect of
invoking the clone, without running the drop implementation of the inner type.
In other words, they aren't really redundant. For example, futures-rs crate:
```rust
#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant.
unsafe fn increase_refcount<T: ArcWake>(data: *const ()) {
// Retain Arc, but don't touch refcount by wrapping in ManuallyDrop
let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
// Now increase refcount, but don't drop new refcount either
let _arc_clone: mem::ManuallyDrop<_> = arc.clone();
}
```
Ignore redundant clone lint for ManuallyDrop.
redundant_closure_call - don't lint when used more than once
Fixes#3354.
changelog: fix redundant_closure_call false positive when closure called more than once
Panic multiple args
changelog: Fixes bug with `panic` lint reported in #5767. I also did the same changes to the lints for `todo`, `unimplemented` and `unreachable`, so those lints should now also detect calls to those macros with a message.
Removing RHS snippet from SHADOW_UNRELATED message.
Fixes#5703
I am not sure if I reinvented the wheel here, but I could not really find a snippet function that did this truncation, so I created the function. Please tell me if there was a more obvious way to do this, I am new here. 😄
changelog: Truncates multi-line RHS in shadow_unrelated message if it has more than 5 lines.
improve advice in iter_nth_zero
fixes#5783
*Please keep the line below*
changelog: For iter_nth_zero, the "use .next()" replacement advice is on the last line of the code snippet, where it is vulnerable to truncation. Display that advice at the beginning instead.
Reprise: new lint: Unintentional return of unit from closures expecting Ord
This lint catches cases where the last statement of a closure expecting
an instance of Ord has a trailing semi-colon. It compiles since the
closure ends up return () which also implements Ord but causes
unexpected results in cases such as sort_by_key.
Fixes#5080
Reprise of #5348 where I addressed all the comments there
changelog: add lint [`unit_return_expecting_ord`]
This lint catches cases where the last statement of a closure expecting
an instance of Ord has a trailing semi-colon. It compiles since the
closure ends up return () which also implements Ord but causes
unexpected results in cases such as sort_by_key.
Fixes#5080
reprise: rebase, update and address all concerns
