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.
When writing a pattern to collect multiple entries of a slice in a
single binding, it is easy to misremember or typo the appropriate syntax
to do so, instead writing the experimental `X..` pattern syntax. When we
encounter a resolve error because `X` isn't available, we suggest
`X @ ..` as an alternative.
```
error[E0425]: cannot find value `rest` in this scope
--> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:3:13
|
LL | [1, rest..] => println!("{rest:?}"),
| ^^^^ not found in this scope
|
help: if you meant to collect the rest of the slice in `rest`, use the at operator
|
LL | [1, rest @ ..] => println!("{rest:?}"),
| +
```
Fix#88404.
Store the laziness of type aliases in their `DefKind`
Previously, we would treat paths referring to type aliases as *lazy* type aliases if the current crate had lazy type aliases enabled independently of whether the crate which the alias was defined in had the feature enabled or not.
With this PR, the laziness of a type alias depends on the crate it is defined in. This generally makes more sense to me especially if / once lazy type aliases become the default in a new edition and we need to think about *edition interoperability*:
Consider the hypothetical case where the dependency crate has an older edition (and thus eager type aliases), it exports a type alias with bounds & a where-clause (which are void but technically valid), the dependent crate has the latest edition (and thus lazy type aliases) and it uses that type alias. Arguably, the bounds should *not* be checked since at any time, the dependency crate should be allowed to change the bounds at will with a *non*-major version bump & without negatively affecting downstream crates.
As for the reverse case (dependency: lazy type aliases, dependent: eager type aliases), I guess it rules out anything from slight confusion to mild annoyance from upstream crate authors that would be caused by the compiler ignoring the bounds of their type aliases in downstream crates with older editions.
---
This fixes#114468 since before, my assumption that the type alias associated with a given weak projection was lazy (and therefore had its variances computed) did not necessarily hold in cross-crate scenarios (which [I kinda had a hunch about](https://github.com/rust-lang/rust/pull/114253#discussion_r1278608099)) as outlined above. Now it does hold.
`@rustbot` label F-lazy_type_alias
r? `@oli-obk`
Add filter with following segment while lookup typo for path
From the discussion: https://github.com/rust-lang/rust/pull/112917#discussion_r1239150173
Seems we can not get the assoc items for `Struct`, `Enum` in the resolving phase.
A obvious filter is avoid suggesting the same name with the following segment path.
Use `following_seg` can extend the function `smart_resolve_partial_mod_path_errors` for more scenarios, such as `std::sync_error::atomic::AtomicBool` in test case.
r? `@estebank`
Suggest publicly accessible paths for items in private mod:
When encountering a path in non-import situations that are not reachable
due to privacy constraints, search for any public re-exports that the
user could use instead.
Track whether an import suggestion is offering a re-export.
When encountering a path with private segments, mention if the item at
the final path segment is not publicly accessible at all.
Add item visibility metadata to privacy errors from imports:
On unreachable imports, record the item that was being imported in order
to suggest publicly available re-exports or to be explicit that the item
is not available publicly from any path.
In order to allow this, we add a mode to `resolve_path` that will not
add new privacy errors, nor return early if it encounters one. This way
we can get the `Res` corresponding to the final item in the import,
which is used in the privacy error machinery.
`#[cfg]`s are frequently used to gate crate content behind cargo
features. This can lead to very confusing errors when features are
missing. For example, `serde` doesn't have the `derive` feature by
default. Therefore, `serde::Serialize` fails to resolve with a generic
error, even though the macro is present in the docs.
This commit adds a list of all stripped item names to metadata. This is
filled during macro expansion and then, through a fed query, persisted
in metadata. The downstream resolver can then access the metadata to
look at possible candidates for mentioning in the errors.
This slightly increases metadata (800k->809k for the feature-heavy
windows crate), but not enough to really matter.
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.
Don't suffix `RibKind` variants
This PR
- Removes `use RibKind::*`
- Renames `RibKind::{SomethingRibKind => Something}`
It seems unnecessary to have "RibKind" in the end of all variants, if we can just use it as a normal enum. Additionally previously it was weird that `MacroDefinition` is the only unsuffixed variant.
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.
My type ascription
Oh rip it out
Ah
If you think we live too much then
You can sacrifice diagnostics
Don't mix your garbage
Into my syntax
So many weird hacks keep diagnostics alive
Yet I don't even step outside
So many bad diagnostics keep tyasc alive
Yet tyasc doesn't even bother to survive!
rustc_middle: Remove trait `DefIdTree`
This trait was a way to generalize over both `TyCtxt` and `Resolver`, but now `Resolver` has access to `TyCtxt`, so this trait is no longer necessary.
With this commit we start to make some simple
check when the name resolution fails, and
we generate some helper message in case the
name is a C name like in the case of the `printf`
and suggest the correct rust method.
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Point only to the identifiers in the typo suggestions of shadowed names instead of the entire struct
Fixes#103358.
As discussed in the issue, the `Span` of the candidate `Ident` for a typo replacement is stored alongside its `Symbol` in `TypoSuggestion`. Then, the span of the identifier is what the "you might have meant to refer to" note is pointed at, rather than the entire struct definition.
Comments in #103111 and the issue both suggest that it is desirable to:
1. include names defined in the same crate as the typo,
2. ignore names defined elsewhere such as in `std`, _and_
3. include names introduced indirectly via `use`.
Since a name from another crate but introduced via `use` has non-local `def_id`, to achieve this, a suggestion is displayed if either the `def_id` of the suggested name is local, or the `span` of the suggested name is in the same file as the typo itself.
Some UI tests have also been modified to reflect this change.
r? `@cjgillot`
`Res::SelfTy` currently has two `Option`s. When the second one is `Some`
the first one is never consulted. So we can split it into two variants,
`Res::SelfTyParam` and `Res::SelfTyAlias`, reducing the size of `Res`
from 24 bytes to 12. This then shrinks `hir::Path` and
`hir::PathSegment`, which are the HIR types that take up the most space.
fix a ui test
use `into`
fix clippy ui test
fix a run-make-fulldeps test
implement `IntoQueryParam<DefId>` for `OwnerId`
use `OwnerId` for more queries
change the type of `ParentOwnerIterator::Item` to `(OwnerId, OwnerNode)`
