Stop bailing out from compilation just because there were incoherent traits
fixes#120343
but also has a lot of "type annotations needed" fallout. Some are fixed in the second commit.
Improve the diagnostics for unused generic parameters
* Don't emit two errors (namely E0091 *and* E0392) for unused type parameters on *lazy* type aliases
* Fix the diagnostic help message of E0392 for *lazy* type aliases: Don't talk about the “fields” of lazy type aliases (use the term “body” instead) and don't suggest `PhantomData` for them, it doesn't make much sense
* Consolidate the diagnostics for E0091 (unused type parameters in type aliases) and E0392 (unused generic parameters due to bivariance) and make it translatable
* Still keep the error codes distinct (for now)
* Naturally leads to better diagnostics for E0091
r? ```@oli-obk``` (to ballast your review load :P) or compiler
```
error[E0277]: the size for values of type `[i32]` cannot be known at compilation time
--> f100.rs:2:33
|
2 | let _ = std::mem::size_of::<[i32]>();
| ^^^^^ doesn't have a size known at compile-time
|
= help: the trait `Sized` is not implemented for `[i32]`
note: required by an implicit `Sized` bound in `std::mem::size_of`
--> /home/gh-estebank/rust/library/core/src/mem/mod.rs:312:22
|
312 | pub const fn size_of<T>() -> usize {
| ^ required by the implicit `Sized` requirement on this bound in `size_of`
```
Fix#120178.
Expand the primary span of E0277 when the immediate unmet bound is not what the user wrote:
```
error[E0277]: the trait bound `i32: Bar` is not satisfied
--> f100.rs:6:6
|
6 | <i32 as Foo>::foo();
| ^^^ the trait `Bar` is not implemented for `i32`, which is required by `i32: Foo`
|
help: this trait has no implementations, consider adding one
--> f100.rs:2:1
|
2 | trait Bar {}
| ^^^^^^^^^
note: required for `i32` to implement `Foo`
--> f100.rs:3:14
|
3 | impl<T: Bar> Foo for T {}
| --- ^^^ ^
| |
| unsatisfied trait bound introduced here
```
Fix#40120.
Deduplicate more sized errors on call exprs
Change the implicit `Sized` `Obligation` `Span` for call expressions to include the whole expression. This aids the existing deduplication machinery to reduce the number of errors caused by a single unsized expression.
Issue tests numbered 1920, 3668, 5997, 23302, 32122, 40510, 57741, 71676, and 76077 were moved to relevant better-named subdirectories. ISSUES_ENTRY_LIMIT was adjusted to match new number of files and FIXME note was expanded.
Change the implicit `Sized` `Obligation` `Span` for call expressions to
include the whole expression. This aids the existing deduplication
machinery to reduce the number of errors caused by a single unsized
expression.
Avoid silencing relevant follow-up errors
r? `@matthewjasper`
This PR only adds new errors to tests that are already failing and fixes one ICE.
Several tests were changed to not emit new errors. I believe all of them were faulty tests, and not explicitly testing for the code that had new errors.
Reorder check_item_type diagnostics so they occur next to the corresponding `check_well_formed` diagnostics
The first commit is just a cleanup.
The second commit moves most checks from `check_mod_item_types` into `check_well_formed`, invoking the checks in lockstep per-item instead of iterating over all items twice.
fix: diagnostic for casting reference to slice
fixes: #118790
Removes `if self.cast_ty.is_trait()` to produce the same diagnostic for cast to slice and trait.
Support bare unit structs in destructuring assignments
We should be allowed to use destructuring assignments on *bare* unit structs, not just unit structs that are located within other pattern constructors.
Fixes#118753
r? petrochenkov since you reviewed #95380, reassign if you're busy or don't want to review this.
On borrow return type, suggest borrowing from arg or owned return type
When we encounter a function with a return type that has an anonymous lifetime with no argument to borrow from, besides suggesting the `'static` lifetime we now also suggest changing the arguments to be borrows or changing the return type to be an owned type.
```
error[E0106]: missing lifetime specifier
--> $DIR/variadic-ffi-6.rs:7:6
|
LL | ) -> &usize {
| ^ expected named lifetime parameter
|
= help: this function's return type contains a borrowed value, but there is no value for it to be borrowed from
help: consider using the `'static` lifetime, but this is uncommon unless you're returning a borrowed value from a `const` or a `static`
|
LL | ) -> &'static usize {
| +++++++
help: instead, you are more likely to want to change one of the arguments to be borrowed...
|
LL | x: &usize,
| +
help: ...or alternatively, to want to return an owned value
|
LL - ) -> &usize {
LL + ) -> usize {
|
```
Fix#85843.
Add lint against ambiguous wide pointer comparisons
This PR is the resolution of https://github.com/rust-lang/rust/issues/106447 decided in https://github.com/rust-lang/rust/issues/117717 by T-lang.
## `ambiguous_wide_pointer_comparisons`
*warn-by-default*
The `ambiguous_wide_pointer_comparisons` lint checks comparison of `*const/*mut ?Sized` as the operands.
### Example
```rust
let ab = (A, B);
let a = &ab.0 as *const dyn T;
let b = &ab.1 as *const dyn T;
let _ = a == b;
```
### Explanation
The comparison includes metadata which may not be expected.
-------
This PR also drops `clippy::vtable_address_comparisons` which is superseded by this one.
~~One thing: is the current naming right? `invalid` seems a bit too much.~~
Fixes https://github.com/rust-lang/rust/issues/117717
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
Tweak message on ADT with private fields building
When trying to create an inaccessible ADT due to private fields, handle the case when no fields were passed.
```
error: cannot construct `Foo` with struct literal syntax due to private fields
--> $DIR/issue-76077.rs:8:5
|
LL | foo::Foo {};
| ^^^^^^^^
|
= note: private field `you_cant_use_this_field` that was not provided
```
When trying to create an inaccessible ADT due to private fields, handle
the case when no fields were passed.
```
error: cannot construct `Foo` with struct literal syntax due to private fields
--> $DIR/issue-76077.rs:8:5
|
LL | foo::Foo {};
| ^^^^^^^^
|
= note: private field `you_cant_use_this_field` that was not provided
```
