Avoid guessing unknown trait implementation in suggestions
When a trait is used without specifying the implementation (e.g. calling a non-member associated function without fully-qualified syntax) and there are multiple implementations available, use a placeholder comment for the implementation type in the suggestion instead of picking a random implementation.
Example:
```
fn main() {
let _ = Default::default();
}
```
Previous output:
```
error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
--> test.rs:2:13
|
2 | let _ = Default::default();
| ^^^^^^^^^^^^^^^^ cannot call associated function of trait
|
help: use a fully-qualified path to a specific available implementation (273 found)
|
2 | let _ = <FileTimes as Default>::default();
| +++++++++++++ +
```
New output:
```
error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
--> test.rs:2:13
|
2 | let _ = Default::default();
| ^^^^^^^^^^^^^^^^ cannot call associated function of trait
|
help: use a fully-qualified path to a specific available implementation (273 found)
|
2 | let _ = </* self type */ as Default>::default();
| +++++++++++++++++++ +
```
Fixes#112897
style-guide: Add language disclaiming any effects on non-default Rust styles
Make it clear that the style guide saying "must" doesn't forbid
developers from doing differently (as though any power on this Earth
could do that) and doesn't forbid tools from allowing any particular
configuration options.
Otherwise, people might wonder (for instance) if there's a semantic difference
between "must" and "should" in the style guide, and whether tools are "allowed"
to offer configurability of something that says "must".
style-guide: Organizational and editing tweaks (no semantic changes)
I'd recommend reviewing this PR commit-by-commit; each commit is self-contained
and should be easy to review at a glance.
- style-guide: Move text about block vs visual indent to indentation section
- style-guide: Move and expand text about trailing commas
- style-guide: s/right-ward/rightward/
- style-guide: Consistently refer to rustfmt as `rustfmt`
- style-guide: Remove inaccurate statement about rustfmt
- style-guide: Define (and capitalize) "ASCIIbetically"
- style-guide: Update cargo.md for authors being optional and not recommended
- style-guide: Avoid normative recommendations for formatting tool configurability
- style-guide: Clarify advice on names matching keywords
- style-guide: Reword an awkwardly phrased recommendation (and fix a typo)
- style-guide: Rephrase a confusingly ordered, ambiguous sentence (and fix a typo)
- style-guide: Avoid hyphenating "semicolon"
- style-guide: Make link text in SUMMARY.md match the headings in the linked pages
- style-guide: Define what an item is
- style-guide: Avoid referring to the style team in the past tense
slice::from_raw_parts: mention no-wrap-around condition
Cc https://github.com/rust-lang/rust/issues/83996. This probably needs to be mentioned in more places, so I am not closing that issue, but this here should help at least.
Don't structurally resolve during method ambiguity in probe
See comment in UI test for reason for the failure. This is all on the error path anyways, not really sure what the assertion is there to achieve anyways...
Fixes#111739
When a trait is used without specifying the implementation (e.g. calling
a non-member associated function without fully-qualified syntax) and
there are multiple implementations available, use a placeholder comment
for the implementation type in the suggestion instead of picking a
random implementation.
Example:
```
fn main() {
let _ = Default::default();
}
```
Previous output:
```
error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
--> test.rs:2:13
|
2 | let _ = Default::default();
| ^^^^^^^^^^^^^^^^ cannot call associated function of trait
|
help: use a fully-qualified path to a specific available implementation (273 found)
|
2 | let _ = <FileTimes as Default>::default();
| +++++++++++++ +
```
New output:
```
error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
--> test.rs:2:13
|
2 | let _ = Default::default();
| ^^^^^^^^^^^^^^^^ cannot call associated function of trait
|
help: use a fully-qualified path to a specific available implementation (273 found)
|
2 | let _ = </* self type */ as Default>::default();
| +++++++++++++++++++ +
```
Make it clear that the style guide saying "must" doesn't forbid
developers from doing differently (as though any power on this Earth
could do that) and doesn't forbid tools from allowing any particular
configuration options.
This sentence had a parenthetical without a closing parenthesis, and had
the phrase "which doesn't require special formatting" ambiguously at the
end of a list when it only applied to the last item of the list.
rustfmt does include a mechanism to distinguish standard library
imports, which it does syntactically by crate name. Avoid making a
misleading statement that implies it cannot do this.
`principles.md` includes some high-level guiding principles for
formatting, but also includes a few specific formatting provisions.
While those provisions apply in many places, the same holds true for
other high-level guidance. Move the text about trailing commas to
`README.md`, so that `principles.md` can focus on guiding principles
while the top level of the style guide gives concrete formatting
recommendations.
`principles.md` includes some high-level guiding principles for
formatting, but also includes a few specific formatting provisions.
While those provisions apply in many places, the same holds true for
other high-level guidance, such as the indentation section. Move the
text about using block indent rather than visual indent to the
indentation section, so that `principles.md` can focus on guiding
principles while the top level of the style guide gives concrete
formatting recommendations.
Account for sealed traits in privacy and trait bound errors
On trait bound errors caused by super-traits, identify if the super-trait is publicly accessibly and if not, explain "sealed traits".
```
error[E0277]: the trait bound `S: Hidden` is not satisfied
--> $DIR/sealed-trait-local.rs:17:20
|
LL | impl a::Sealed for S {}
| ^ the trait `Hidden` is not implemented for `S`
|
note: required by a bound in `Sealed`
--> $DIR/sealed-trait-local.rs:3:23
|
LL | pub trait Sealed: self:🅱️:Hidden {
| ^^^^^^^^^^^^^^^ required by this bound in `Sealed`
= note: `Sealed` is a "sealed trait", because to implement it you also need to implelement `a:🅱️:Hidden`, which is not accessible; this is usually done to force you to use one of the provided types that already implement it
```
Deduplicate privacy errors that point to the same path segment even if their deduplication span are different.
When encountering a path that is not reachable due to privacy constraints path segments other than the last, keep metadata for the last path segment's `Res` in order to look for alternative import paths for that item to suggest. If there are none, be explicit that the item is not accessible.
```
error[E0603]: module `b` is private
--> $DIR/re-exported-trait.rs:11:9
|
LL | impl a:🅱️:Trait for S {}
| ^ private module
|
note: the module `b` is defined here
--> $DIR/re-exported-trait.rs:5:5
|
LL | mod b {
| ^^^^^
help: consider importing this trait through its public re-export instead
|
LL | impl a::Trait for S {}
| ~~~~~~~~
```
```
error[E0603]: module `b` is private
--> $DIR/private-trait.rs:8:9
|
LL | impl a:🅱️:Hidden for S {}
| ^ ------ trait `b` is not publicly reachable
| |
| private module
|
note: the module `b` is defined here
--> $DIR/private-trait.rs:2:5
|
LL | mod b {
| ^^^^^
```
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.
When implementing a public trait with a private super-trait, we now emit
a note that the missing bound is not going to be able to be satisfied,
and we explain the concept of a sealed trait.
Avoid `Lrc<Box<dyn CodegenBackend>>`.
Because `Lrc<Box<T>>` is silly. (Clippy warns about `Rc<Box<T>>` and `Arc<Box<T>>`, and it would warn here if (a) we used Clippy with rustc, and (b) Clippy knew about `Lrc`.)
r? `@bjorn3`
Inline before merging cgus
Because CGU merging relies on CGU sizes, but the CGU sizes before inlining aren't accurate.
This change doesn't have much effect on compile perf, but it makes follow-on changes that involve more sophisticated reasoning about CGU sizes much easier.
r? `@wesleywiser`
Rollup of 4 pull requests
Successful merges:
- #112876 (Don't substitute a GAT that has mismatched generics in `OpaqueTypeCollector`)
- #112906 (rustdoc: render the body of associated types before the where-clause)
- #112907 (Update cargo)
- #112908 (Print def_id on EarlyBoundRegion debug)
r? `@ghost`
`@rustbot` modify labels: rollup
Print def_id on EarlyBoundRegion debug
It's not the first time that I can't make sense out of the default debug print on `EarlyBoundRegion`. As I was working on #112682 I needed this.
I was doing some git archeology and found that we used to print everything dfbc9608ce/src/librustc/util/ppaux.rs (L425-L430) but we lost the ability in some refactor midway.
Don't substitute a GAT that has mismatched generics in `OpaqueTypeCollector`
Fixes#111828
I didn't put up minimized UI tests for #112510 or #112873 because they'd minimize to literally the same code, but with different substs on the trait/impl. I don't think that warrants duplicate tests given the nature of the fix.
r? `@oli-obk`
----
Side-note: I checked, and this isn't fixed by #112652 -- I think we discussed whether or not that PR fixed it either intentionally or by accident. The code here isn't really touched by that PR either as far as I can tell?
Also, sorry, did some other drive-bys. Hope it doesn't make rebasing #112652 too difficult 😅
- Rename `create_size_estimate` as `compute_size_estimate`, because that
makes more sense for the second and subsequent calls for each CGU.
- Change `CodegenUnit::size_estimate` from `Option<usize>` to `usize`.
We can still assert that `compute_size_estimate` is called first.
- Move the size estimation for `place_mono_items` inside the function,
for consistency with `merge_codegen_units`.
Because `Lrc<Box<T>>` is silly. (Clippy warns about `Rc<Box<T>>` and
`Arc<Box<T>>`, and it would warn here if (a) we used Clippy with rustc,
and (b) Clippy knew about `Lrc`.)
The codegen main loop has two bools, `codegen_done` and
`codegen_aborted`. There are only three valid combinations: `(false,
false)`, `(true, false)`, `(true, true)`.
This commit replaces them with a single tri-state enum, which makes
things clearer.
