Check uniqueness of impl items by trait item when applicable.
When checking uniqueness of item names in impl blocks, we currently use the same definition of hygiene as for toplevel items. This means that a plain item and one generated by a macro 2.0 do not collide.
This hygiene rule does not match with how impl items resolve to associated trait items. As a consequence, we misdiagnose the trait impls.
This PR proposes to consider that trait impl items are uses of the corresponding trait items during resolution, instead of checking for duplicates later. An error is emitted when a trait impl item is used twice.
There should be no stable breakage, since macros 2.0 are still unstable.
r? ``@petrochenkov``
cc ``@RalfJung``
Fixes https://github.com/rust-lang/rust/issues/71614.
Move lifetime resolution module to rustc_hir_analysis.
Now that lifetime resolution has been removed from it, this file has nothing to do in `rustc_resolve`. It's purpose is to compute Debruijn indices for lifetimes, so let's put it in type collection.
suggest candidates for unresolved import
Currently we prompt suggestion of candidates(help notes of `use xxx::yyy`) for names which cannot be resolved, but we don't do that for import statements themselves that couldn't be resolved. It seems reasonable to add candidate help information for these statements as well.
Fixes#102711
Following the approach taken in earlier commits to separate formatting
initialization from use in the subdiagnostic derive, simplify the
diagnostic derive by removing the field-ordering logic that previously
solved this problem.
Signed-off-by: David Wood <david.wood@huawei.com>
Diagnostic derives have previously had to take special care when
ordering the generated code so that fields were not used after a move.
This is unlikely for most fields because a field is either annotated
with a subdiagnostic attribute and is thus likely a `Span` and copiable,
or is a argument, in which case it is only used once by `set_arg`
anyway.
However, format strings for code in suggestions can result in fields
being used after being moved if not ordered carefully. As a result, the
derive currently puts `set_arg` calls last (just before emission), such
as:
```rust
let diag = { /* create diagnostic */ };
diag.span_suggestion_with_style(
span,
fluent::crate::slug,
format!("{}", __binding_0),
Applicability::Unknown,
SuggestionStyle::ShowAlways
);
/* + other subdiagnostic additions */
diag.set_arg("foo", __binding_0);
/* + other `set_arg` calls */
diag.emit();
```
For eager translation, this doesn't work, as the message being
translated eagerly can assume that all arguments are available - so
arguments _must_ be set first.
Format strings for suggestion code are now separated into two parts - an
initialization line that performs the formatting into a variable, and a
usage in the subdiagnostic addition.
By separating these parts, the initialization can happen before
arguments are set, preserving the desired order so that code compiles,
while still enabling arguments to be set before subdiagnostics are
added.
```rust
let diag = { /* create diagnostic */ };
let __code_0 = format!("{}", __binding_0);
/* + other formatting */
diag.set_arg("foo", __binding_0);
/* + other `set_arg` calls */
diag.span_suggestion_with_style(
span,
fluent::crate::slug,
__code_0,
Applicability::Unknown,
SuggestionStyle::ShowAlways
);
/* + other subdiagnostic additions */
diag.emit();
```
Signed-off-by: David Wood <david.wood@huawei.com>
Add support for `eager` argument to the `subdiagnostic` attribute which
generates a call to `eager_subdiagnostic`.
Signed-off-by: David Wood <david.wood@huawei.com>
Add variant of `DiagnosticMessage` for eagerly translated messages
(messages in the target language which don't need translated by the
emitter during emission). Also adds `eager_subdiagnostic` function which
is intended to be invoked by the diagnostic derive for subdiagnostic
fields which are marked as needing eager translation.
Signed-off-by: David Wood <david.wood@huawei.com>
`AddToDiagnostic::add_to_diagnostic_with` is similar to the previous
`AddToDiagnostic::add_to_diagnostic` but takes a function that can be
used by the caller to modify diagnostic messages originating from the
subdiagnostic (such as performing translation eagerly).
`add_to_diagnostic` now just calls `add_to_diagnostic_with` with an
empty closure.
Signed-off-by: David Wood <david.wood@huawei.com>
Eager translation will enable subdiagnostics to be translated multiple
times with different arguments - this requires the ability to replace
the value of one argument with a new value, which is better suited to a
`HashMap` than the previous storage, a `Vec`.
Signed-off-by: David Wood <david.wood@huawei.com>
Uplift `clippy::for_loops_over_fallibles` lint into rustc
This PR, as the title suggests, uplifts [`clippy::for_loops_over_fallibles`] lint into rustc. This lint warns for code like this:
```rust
for _ in Some(1) {}
for _ in Ok::<_, ()>(1) {}
```
i.e. directly iterating over `Option` and `Result` using `for` loop.
There are a number of suggestions that this PR adds (on top of what clippy suggested):
1. If the argument (? is there a better name for that expression) of a `for` loop is a `.next()` call, then we can suggest removing it (or rather replacing with `.by_ref()` to allow iterator being used later)
```rust
for _ in iter.next() {}
// turns into
for _ in iter.by_ref() {}
```
2. (otherwise) We can suggest using `while let`, this is useful for non-iterator, iterator-like things like [async] channels
```rust
for _ in rx.recv() {}
// turns into
while let Some(_) = rx.recv() {}
```
3. If the argument type is `Result<impl IntoIterator, _>` and the body has a `Result<_, _>` type, we can suggest using `?`
```rust
for _ in f() {}
// turns into
for _ in f()? {}
```
4. To preserve the original behavior and clear intent, we can suggest using `if let`
```rust
for _ in f() {}
// turns into
if let Some(_) = f() {}
```
(P.S. `Some` and `Ok` are interchangeable depending on the type)
I still feel that the lint wording/look is somewhat off, so I'll be happy to hear suggestions (on how to improve suggestions :D)!
Resolves#99272
[`clippy::for_loops_over_fallibles`]: https://rust-lang.github.io/rust-clippy/master/index.html#for_loops_over_fallibles
Add missing documentation for FileNameDisplayPreference variants
Took me a while to find the information when I needed it so hopefully it should save some time for the next ones.
r? ``@thomcc``
Elaborate trait ref to compute object safety.
instead of building them manually from supertraits and associated items.
This allows to have the correct substs for GATs.
Fixes https://github.com/rust-lang/rust/issues/102751
rename `ImplItemKind::TyAlias` to `ImplItemKind::Type`
The naming of this variant seems inconsistent given that this is not really a "type alias", and the associated type variant for `TraitItemKind` is just called `Type`.
Show let-else suggestion on stable.
The E0005 error message has a suggestion to use let-else. Now that let-else is stabilized, I think this message should be included on non-nightly toolchains. I suspect this was just an oversight from #93628. [`E0005.stderr`](be1c7aad72/src/test/ui/error-codes/E0005.stderr (L22-L25)) contains an example of what this suggestion looks like.
