* Point at RHS of associated type in obligation span
* Point at `impl` assoc type on projection error
* Reduce verbosity of recursive obligations
* Point at source of binding lifetime obligation
* Tweak "required bound" note
* Tweak "expected... found opaque (return) type" labels
* Point at set type in impl assoc type WF errors
* Do not emit unnecessary E0308 after E0070
* Show fewer errors on `while let` missing `let`
* Hide redundant E0308 on `while let` missing `let`
* Point at binding definition when possible on invalid assignment
* do not point at closure twice
* do not suggest `if let` for literals in lhs
* account for parameter types
Be more thorough in using `ItemObligation` and `BindingObligation` when
evaluating obligations so that we can point at trait bounds that
introduced unfulfilled obligations. We no longer incorrectly point at
unrelated trait bounds (`substs-ppaux.verbose.stderr`).
In particular, we now point at trait bounds on method calls.
We no longer point at "obvious" obligation sources (we no longer have a
note pointing at `Trait` saying "required by a bound in `Trait`", like
in `associated-types-no-suitable-supertrait*`).
Address part of #89418.
Clarify error messages caused by re-exporting `pub(crate)` visibility to outside
This PR clarifies error messages and suggestions caused by re-exporting pub(crate) visibility outside the crate.
Here is a small example ([Rust Playground](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=e2cd0bd4422d4f20e6522dcbad167d3b)):
```rust
mod m {
pub(crate) enum E {}
}
pub use m::E;
fn main() {}
```
This code is compiled to:
```
error[E0365]: `E` is private, and cannot be re-exported
--> prog.rs:4:9
|
4 | pub use m::E;
| ^^^^ re-export of private `E`
|
= note: consider declaring type or module `E` with `pub`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0365`.
```
However, enum `E` is actually public to the crate, not private totally—nevertheless, rustc treats `pub(crate)` and private visibility as the same on the error messages. They are not clear and should be segmented distinctly.
By applying changes in this PR, the error message below will be the following message that would be clearer:
```
error[E0365]: `E` is only public to inside of the crate, and cannot be re-exported outside
--> prog.rs:4:9
|
4 | pub use m::E;
| ^^^^ re-export of crate public `E`
|
= note: consider declaring type or module `E` with `pub`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0365`.
```
Stabilize `const_raw_ptr_deref` for `*const T`
This stabilizes dereferencing immutable raw pointers in const contexts.
It does not stabilize `*mut T` dereferencing. This is behind the
same feature gate as mutable references.
closes https://github.com/rust-lang/rust/issues/51911
This stabilizes dereferencing immutable raw pointers in const contexts.
It does not stabilize `*mut T` dereferencing. This is placed behind the
`const_raw_mut_ptr_deref` feature gate.
Emit description of the ambiguity as a note.
Co-authored-by: Noah Lev <camelidcamel@gmail.com>
Co-authored-by: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Update E0637 description to mention `&` w/o an explicit lifetime name
Deal with https://github.com/rust-lang/rust/issues/89824#issuecomment-941598647. Another solution would be splitting the error code into two as (I think) it's a bit unclear to users why they have the same error code.
Some "parenthesis" and "parentheses" fixes
"Parenthesis" is the singular (e.g. one `(` or one `)`) and "parentheses" is the plural (multiple `(` or `)`s) and this is not hard to mix up so here are some fixes for that.
Inspired by #89958
Remove textual span from diagnostic string
This is an unnecessary repetition, as the diagnostic prints the span anyway in the source path right below the message.
I further removed the identification of the node, as that does not give any new information in any of the cases that are changed in tests.
EDIT: also inserted a suggestion that other diagnostics were already emitting
The test is copied from `src/test/ui/crate-loading/crateresolve1.rs` and
its auxiliary tests. I added it to the `compile_fail` code example check
exemption list since it's hard if not impossible to reproduce this error
in a standalone code example.
A subset of places referred to 'super-trait', so this changes them
to all use 'supertrait'. This matches 'supertype' and some other
usages. An exception is 'auto-trait' which is consistently used
in that manner.
Suggest similarly named associated items in trait impls
Fix#85942
Previously, the compiler didn't suggest similarly named associated items unlike we do in many situations. This patch adds such diagnostics for associated functions, types, and constants.
Improve help for recursion limit errors
- Tweak help message and suggested limit (handle `0` case).
- Add test for #75602 (it was already fixed, maybe can be resolved too).
Fixes#76424
Use larger span for adjustment THIR expressions
Currently, we use a relatively 'small' span for THIR
expressions generated by an 'adjustment' (e.g. an autoderef,
autoborrow, unsizing). As a result, if a borrow generated
by an adustment ends up causing a borrowcheck error, for example:
```rust
let mut my_var = String::new();
let my_ref = &my_var
my_var.push('a');
my_ref;
```
then the span for the mutable borrow may end up referring
to only the base expression (e.g. `my_var`), rather than
the method call which triggered the mutable borrow
(e.g. `my_var.push('a')`)
Due to a quirk of the MIR borrowck implementation,
this doesn't always get exposed in migration mode,
but it does in many cases.
This commit makes THIR building consistently use 'larger'
spans for adjustment expressions. These spans are recoded
when we first create the adjustment during typecheck. For
example, an autoref adjustment triggered by a method call
will record the span of the entire method call.
The intent of this change it make it clearer to users
when it's the specific way in which a variable is
used (for example, in a method call) that produdes
a borrowcheck error. For example, an error message
claiming that a 'mutable borrow occurs here' might
be confusing if it just points at a usage of a variable
(e.g. `my_var`), when no `&mut` is in sight. Pointing
at the entire expression should help to emphasize
that the method call itself is responsible for
the mutable borrow.
In several cases, this makes the `#![feature(nll)]` diagnostic
output match up exactly with the default (migration mode) output.
As a result, several `.nll.stderr` files end up getting removed
entirely.
Previously, the compiler didn't suggest similarly named associated items
unlike we do in many situations. This patch adds such diagnostics for
associated functions, types and constants.
Currently, we use a relatively 'small' span for THIR
expressions generated by an 'adjustment' (e.g. an autoderef,
autoborrow, unsizing). As a result, if a borrow generated
by an adustment ends up causing a borrowcheck error, for example:
```rust
let mut my_var = String::new();
let my_ref = &my_var
my_var.push('a');
my_ref;
```
then the span for the mutable borrow may end up referring
to only the base expression (e.g. `my_var`), rather than
the method call which triggered the mutable borrow
(e.g. `my_var.push('a')`)
Due to a quirk of the MIR borrowck implementation,
this doesn't always get exposed in migration mode,
but it does in many cases.
This commit makes THIR building consistently use 'larger'
spans for adjustment expressions
The intent of this change it make it clearer to users
when it's the specific way in which a variable is
used (for example, in a method call) that produdes
a borrowcheck error. For example, an error message
claiming that a 'mutable borrow occurs here' might
be confusing if it just points at a usage of a variable
(e.g. `my_var`), when no `&mut` is in sight. Pointing
at the entire expression should help to emphasize
that the method call itself is responsible for
the mutable borrow.
In several cases, this makes the `#![feature(nll)]` diagnostic
output match up exactly with the default (migration mode) output.
As a result, several `.nll.stderr` files end up getting removed
entirely.
Point at argument instead of call for their obligations
When an obligation is introduced by a specific `fn` argument, point at
the argument instead of the `fn` call if the obligation fails to be
fulfilled.
Move the information about pointing at the call argument expression in
an unmet obligation span from the `FulfillmentError` to a new
`ObligationCauseCode`.
When giving an error about an obligation introduced by a function call
that an argument doesn't fulfill, and that argument is a block, add a
span_label pointing at the innermost tail expression.
Current output:
```
error[E0425]: cannot find value `x` in this scope
--> f10.rs:4:14
|
4 | Some(x * 2)
| ^ not found in this scope
error[E0277]: expected a `FnOnce<({integer},)>` closure, found `Option<_>`
--> f10.rs:2:31
|
2 | let p = Some(45).and_then({
| ______________________--------_^
| | |
| | required by a bound introduced by this call
3 | | |x| println!("doubling {}", x);
4 | | Some(x * 2)
| | -----------
5 | | });
| |_____^ expected an `FnOnce<({integer},)>` closure, found `Option<_>`
|
= help: the trait `FnOnce<({integer},)>` is not implemented for `Option<_>`
```
Previous output:
```
error[E0425]: cannot find value `x` in this scope
--> f10.rs:4:14
|
4 | Some(x * 2)
| ^ not found in this scope
error[E0277]: expected a `FnOnce<({integer},)>` closure, found `Option<_>`
--> f10.rs:2:22
|
2 | let p = Some(45).and_then({
| ^^^^^^^^ expected an `FnOnce<({integer},)>` closure, found `Option<_>`
|
= help: the trait `FnOnce<({integer},)>` is not implemented for `Option<_>`
```
Partially address #27300. Will require rebasing on top of #88546.
Use smaller spans for some structured suggestions
Use more accurate suggestion spans for
* argument parse error
* fully qualified path
* missing code block type
* numeric casts
