Gracefully handle ternary operator
Fixes#112578
~~May not be the best way to do this as it doesn't check for a single `:`, so it could perhaps appear even when the actual issue is just a missing semicolon. May not be the biggest deal, though?~~
Nevermind, got it working properly now ^^
It doesn't really matter what the `desugar_doc_comments` argument is
here, because in practice we never look ahead through doc comments.
Changing it to `cursor.desugar_doc_comments` will allow some follow-up
simplifications.
Reimplement C-str literals
This reverts #113334, cc `@fmease.`
While converting lexer tokens to ast Tokens in `rustc_parse`, we check the edition of the span of the token. If the edition < 2021, we split the token into two, one being the identifier and other being the str literal.
Optimize format usage
Per #112156, using `&` in `format!` may cause a small perf delay, so I tried to clean up one module at a time format usage. This PR includes a few removals of the ref in format (they do compile locally without the ref), as well as a few format inlining for consistency.
Per #112156, using `&` in `format!` may cause a small perf delay, so I tried to clean up one module at a time format usage. This PR includes a few removals of the ref in format (they do compile locally without the ref), as well as a few format inlining for consistency.
Fix inline_const with interpolated block
Interpolation already worked when we had a `const $block` that wasn't a statement expr:
```
fn foo() {
let _ = const $block;
}
```
But it was failing when the const block was in statement expr position:
```
fn foo() {
const $block;
}
```
... because of a bug in a check for const items. This fixes that.
---
cc https://github.com/rust-lang/rust/pull/112953#issuecomment-1631354481, though I don't think this requires an FCP since it's already supported in exprs and seems to me to be fully a parser bug.
Instead of linking to the old Rust Reference site on static.rust-lang.org,
link to the current website doc.rust-lang.org/stable/reference instead in
diagnostic about incorrect literals.
Use `Cow` in `{D,Subd}iagnosticMessage`.
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.
r? `@WaffleLapkin`
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.
Give a more useful location for where a span_bug was delayed
Before:
```
= note: delayed at 0: <rustc_errors::HandlerInner>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1335:29
1: <rustc_errors::Handler>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1124:9
...
```
After:
```
= note: delayed at compiler/rustc_parse/src/parser/diagnostics.rs:2158:28
0: <rustc_errors::HandlerInner>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1335:29
1: <rustc_errors::Handler>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1124:9
...
```
This both makes the relevant frame easier to find without having to dig through diagnostic internals, and avoids the weird-looking formatting for the first frame.
Found while working on https://github.com/rust-lang/rust/issues/111529.
Do not recover when parsing stmt in cfg-eval.
`parse_stmt` does recovery on its own. When parsing the statement fails, we always get `Ok(None)` instead of an `Err` variant with the diagnostic that we can emit.
To avoid this behaviour, we need to opt-out of recovery for cfg_eval.
Fixes https://github.com/rust-lang/rust/issues/105228
Before:
```
= note: delayed at 0: <rustc_errors::HandlerInner>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1335:29
1: <rustc_errors::Handler>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1124:9
...
```
After:
```
= note: delayed at compiler/rustc_parse/src/parser/diagnostics.rs:2158:28
0: <rustc_errors::HandlerInner>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1335:29
1: <rustc_errors::Handler>::emit_diagnostic
at ./compiler/rustc_errors/src/lib.rs:1124:9
```
This both makes the relevant frame easier to find without having to dig
through diagnostic internals, and avoids the weird-looking formatting
for the first frame.
Error message all end up passing into a function as an `impl
Into<{D,Subd}iagnosticMessage>`. If an error message is creatd as
`&format("...")` that means we allocate a string (in the `format!`
call), then take a reference, and then clone (allocating again) the
reference to produce the `{D,Subd}iagnosticMessage`, which is silly.
This commit removes the leading `&` from a lot of these cases. This
means the original `String` is moved into the
`{D,Subd}iagnosticMessage`, avoiding the double allocations. This
requires changing some function argument types from `&str` to `String`
(when all arguments are `String`) or `impl
Into<{D,Subd}iagnosticMessage>` (when some arguments are `String` and
some are `&str`).
Implement builtin # syntax and use it for offset_of!(...)
Add `builtin #` syntax to the parser, as well as a generic infrastructure to support both item and expression position builtin syntaxes. The PR also uses this infrastructure for the implementation of the `offset_of!` macro, added by #106934.
cc `@petrochenkov` `@DrMeepster`
cc #110680 `builtin #` tracking issue
cc #106655 `offset_of!` tracking issue
add hint for =< as <=
Adds a compiler hint for when `=<` is typed instead of `<=`
Example hint:
```rust
fn foo() {
if 1 =< 3 {
println!("Hello, World!");
}
}
```
```
error: expected type, found `3`
--> main.rs:2:13
|
2 | if 1 =< 3 {
| -- ^ expected type
| |
| help: did you mean: `<=`
```
This PR only emits the suggestion if there is no space between the `=` and `<`. This hopefully narrows the scope of when this error is emitted, however this still allows this error to be emitted in cases such as this:
```
error: expected expression, found `;`
--> main.rs:2:18
|
2 | if 1 =< [i32;; 3]>::hello() {
| -- ^ expected expression
| |
| help: did you mean: `<=`
```
Which could be a good reason not to merge since I haven't been able to think of any other ways of narrowing the scope of this diagnostic.
closes#111128
Implement negative bounds for internal testing purposes
Implements partial support the `!` negative polarity on trait bounds. This is incomplete, but should allow us to at least be able to play with the feature.
Not even gonna consider them as a public-facing feature, but I'm implementing them because would've been nice to have in UI tests, for example in #110671.
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!
Tweak await span to not contain dot
Fixes a discrepancy between method calls and await expressions where the latter are desugared to have a span that *contains* the dot (i.e. `.await`) but method call identifiers don't contain the dot. This leads to weird suggestions suggestions in borrowck -- see linked issue.
Fixes#110761
This mostly touches a bunch of tests to tighten their `await` span.
Add `rustc_fluent_macro` to decouple fluent from `rustc_macros`
Fluent, with all the icu4x it brings in, takes quite some time to compile. `fluent_messages!` is only needed in further downstream rustc crates, but is blocking more upstream crates like `rustc_index`. By splitting it out, we allow `rustc_macros` to be compiled earlier, which speeds up `x check compiler` by about 5 seconds (and even more after the needless dependency on `serde_json` is removed from `rustc_data_structures`).
Fluent, with all the icu4x it brings in, takes quite some time to
compile. `fluent_messages!` is only needed in further downstream rustc
crates, but is blocking more upstream crates like `rustc_index`. By
splitting it out, we allow `rustc_macros` to be compiled earlier, which
speeds up `x check compiler` by about 5 seconds (and even more after the
needless dependency on `serde_json` is removed from
`rustc_data_structures`).
Remove `..` from return type notation
`@nikomatsakis` and I decided that using `..` in the return-type notation syntax is probably overkill.
r? `@eholk` since you reviewed the last one
Since this is piggybacking now totally off of a pre-existing syntax (parenthesized generics), let me know if you need any explanation of the logic here, since it's a bit more complicated now.
Avoid a few locks
We can use atomics or datastructures tuned for specific access patterns instead of locks. This may be an improvement for parallel rustc, but it's mostly a cleanup making various datastructures only usable in the way they are used right now (append data, never mutate), instead of having a general purpose lock.
Remove the `NodeId` of `ast::ExprKind::Async`
This is a followup to https://github.com/rust-lang/rust/pull/104833#pullrequestreview-1314537416.
In my original attempt, I was using `LoweringContext::expr`, which was not correct as it creates a fresh `DefId`.
It now uses the correct `DefId` for the wrapping `Expr`, and also makes forwarding `#[track_caller]` attributes more explicit.
Remove `box_syntax`
r? `@Nilstrieb`
This removes the feature `box_syntax`, which allows the use of `box <expr>` to create a Box, and finalises removing use of the feature from the compiler. `box_patterns` (allowing the use of `box <pat>` in a pattern) is unaffected.
It also removes `ast::ExprKind::Box` - the only way to create a 'box' expression now is with the rustc-internal `#[rustc_box]` attribute.
As a temporary measure to help users move away, `box <expr>` now parses the inner expression, and emits a `MachineApplicable` lint to replace it with `Box::new`
Closes#49733
Gate usages of `dyn*` and const closures in macros
We silently accepted `dyn*` and const closures in macros as long as they didn't expand to anything containing these experimental features, unlike other gated features such as `for<'a>` binders on closures, etc. Let's not do that, to make sure nobody begins relying on this.
This makes it easier to open the messages file while developing on features.
The commit was the result of automatted changes:
for p in compiler/rustc_*; do mv $p/locales/en-US.ftl $p/messages.ftl; rmdir $p/locales; done
for p in compiler/rustc_*; do sed -i "s#\.\./locales/en-US.ftl#../messages.ftl#" $p/src/lib.rs; done
feat/refactor: improve errors in case of ident with number at start
Improve parser code when we parse a integer (or float) literal but expect an identifier. We emit an error message saying that identifiers can't begin with numbers. This PR just improves that code and expands it to all identifiers. Note that I haven't implemented error recovery (this didn't exist before anyway), I might do that in a follow up PR.
Replace parse_[sth]_expr with parse_expr_[sth] function names
This resolves an inconsistency in naming style for functions on the parser, where:
* functions parsing specific kinds of items are named `parse_item_[sth]` and
* functions parsing specific kinds of *expressions* are named `parse_[sth]_expr`
favoring the style used by functions for items. There are multiple advantages of that style:
* functions of both categories are collected in the same place in the [rustdoc output](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse/parser/struct.Parser.html).
* it helps with autocompletion, as you can narrow down your search for a function to those about expressions.
* it mirrors rust's path syntax where less specific things come first, then it gets more specific, i.e. `std::collections::hash_map::Entry`.
The disadvantage is that it doesn't "read like a sentence" any more. But I think the advantages weigh more greatly.
This change was mostly application of this command:
```
sed -i -E 's/(fn |\.)parse_([[:alnum:]_]+)_expr/\1parse_expr_\2/' compiler/rustc_parse/src/parser/*.rs
```
Plus very minor fixes outside of `rustc_parse`, and an invocation of `x fmt`.
This resolves an inconsistency in naming style for functions
on the parser, between functions parsing specific kinds of items
and those for expressions, favoring the parse_item_[sth] style
used by functions for items. There are multiple advantages
of that style:
* functions of both categories are collected in the same place
in the rustdoc output.
* it helps with autocompletion, as you can narrow down your
search for a function to those about expressions.
* it mirrors rust's path syntax where less specific things
come first, then it gets more specific, i.e.
std::collections::hash_map::Entry
The disadvantage is that it doesn't "read like a sentence"
any more, but I think the advantages weigh more greatly.
This change was mostly application of this command:
sed -i -E 's/(fn |\.)parse_([[:alnum:]_]+)_expr/\1parse_expr_\2/' compiler/rustc_parse/src/parser/*.rs
Plus very minor fixes outside of rustc_parse, and an invocation
of x fmt.
We currently provide wrong suggestions and unhelpful errors on closure
bodies with braces missing. For example, given the following code:
```
fn main() {
let _x = Box::new(|x|x+1;);
}
```
the current output is like this:
```
error: expected expression, found `)`
--> ./main.rs:2:30
|
2 | let _x = Box::new(|x|x+1;);
| ^ expected expression
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^
3 | }
| ^
|
...
help: try adding braces
|
2 ~ let _x = Box::new(|x| {x+1;);
3 ~ }}
...
error: expected `;`, found `}`
--> ./main.rs:2:32
|
2 | let _x = Box::new(|x|x+1;);
| ^ help: add `;` here
3 | }
| - unexpected token
error: aborting due to 3 previous errors
```
This commit allows outputting correct suggestions and errors. The above
code would output like this:
```
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^ ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ - ...but likely you meant the closure to end here
| |
| this is the parsed closure...
help: try adding braces
|
2 | let _x = Box::new(|x| {x+1;});
| + +
error: aborting due to previous error
```
Instead of loading the Fluent resources for every crate in
`rustc_error_messages`, each crate generates typed identifiers for its
own diagnostics and creates a static which are pulled together in the
`rustc_driver` crate and provided to the diagnostic emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
Use restricted Damerau-Levenshtein distance for diagnostics
This replaces the existing Levenshtein algorithm with the Damerau-Levenshtein algorithm. This means that "ab" to "ba" is one change (a transposition) instead of two (a deletion and insertion). More specifically, this is a _restricted_ implementation, in that "ca" to "abc" cannot be performed as "ca" → "ac" → "abc", as there is an insertion in the middle of a transposition. I believe that errors like that are sufficiently rare that it's not worth taking into account.
This was first brought up [on IRLO](https://internals.rust-lang.org/t/18227) when it was noticed that the diagnostic for `prinltn!` (transposed L and T) was `print!` and not `println!`. Only a single existing UI test was effected, with the result being an objective improvement.
~~I have left the method name and various other references to the Levenshtein algorithm untouched, as the exact manner in which the edit distance is calculated should not be relevant to the caller.~~
r? ``@estebank``
``@rustbot`` label +A-diagnostics +C-enhancement
Don't recover lifetimes/labels containing emojis as character literals
Fixes#108019.
Note that at the time of this commit, `unic-emoji-char` seems to have data tables only up to Unicode 5.0, but Unicode is already newer than this.
A newer emoji such as `🥺` will not be recognized as an emoji but older emojis such as `🐱` will.
This PR leaves a couple of FIXMEs where `unic_emoji_char::is_emoji` is used.
Suggest fix for misplaced generic params on fn item #103366fixes#103366
This still has some work to go, but works for 2/3 of the initial base cases described in #1033366
simple fn:
```
error: expected identifier, found `<`
--> shreys/test_1.rs:1:3
|
1 | fn<T> id(x: T) -> T { x }
| ^ expected identifier
|
help: help: place the generic parameter list after the function name:
|
1 | fn id<T>(x: T) -> T { x }
| ~~~~
```
Complicated bounds
```
error: expected identifier, found `<`
--> spanishpear/test_2.rs:1:3
|
1 | fn<'a, B: 'a + std::ops::Add<Output = u32>> f(_x: B) { }
| ^ expected identifier
|
help: help: place the generic parameter list after the function name:
|
1 | fn f<'a, B: 'a + std::ops::Add<Output = u32>>(_x: B) { }
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Opening a draft PR for comments on approach, particularly I have the following questions:
- [x] Is it okay to be using `err.span_suggestion` over struct derives? I struggled to get the initial implementation (particularly the correct suggestion message) on struct derives, although I think given what I've learned since starting, I could attempt re-doing it with that approach.
- [x] in the case where the snippet cannot be obtained from a span, is the `help` but no suggestion okay? I think yes (also, when does this case occur?)
- [x] are there any red flags for the generalisation of this work for relevant item kinds (i.e. `struct`, `enum`, `trait`, and `union`). My basic testing indicates it does work for those types except the help tip is currently hardcoded to `after the function name` - which should change dependent on the item.
- [x] I am planning to not show the suggestion if there is already a `<` after the item identifier, (i.e. if there are already generics, as after a function name per the original issue). Any major objections?
- [x] Is the style of error okay? I wasn't sure if there was a way to make it display nicer, or if thats handled by span_suggestion
These aren't blocking questions, and I will keep working on:
- check if there is a `<` after the ident (and if so, not showing the suggestion)
- generalize the help message
- figuring out how to write/run/etc ui tests (including reading the docs for them)
- logic cleanups
Note that at the time of this commit, `unic-emoji-char` seems to have
data tables only up to Unicode 5.0, but Unicode is already newer than
this.
A newer emoji such as `🥺` will not be recognized as an emoji
but older emojis such as `🐱` will.
The motivation here is to eliminate the `Option<(Delimiter,
DelimSpan)>`, which is `None` for the outermost token stream and `Some`
for all other token streams.
We are already treating the innermost frame specially -- this is the
`frame` vs `stack` distinction in `TokenCursor`. We can push that
further so that `frame` only contains the cursor, and `stack` elements
contain the delimiters for their children. When we are in the outermost
token stream `stack` is empty, so there are no stored delimiters, which
is what we want because the outermost token stream *has* no delimiters.
This change also shrinks `TokenCursor`, which shrinks `Parser` and
`LazyAttrTokenStreamImpl`, which is nice.
Sometimes the parser needs to desugar a doc comment into `#[doc =
r"foo"]`. Currently it does this in a hacky way: by pushing a "fake" new
frame (one without a delimiter) onto the `TokenCursor` stack.
This commit changes things so that the token stream itself is modified
in place. The nice thing about this is that it means
`TokenCursorFrame::delim_sp` is now only `None` for the outermost frame.
Improve diagnostic for missing space in range pattern
Improves the diagnostic in #107425 by turning it into a note explaining the parsing issue.
r? `@compiler-errors`
Revert "review comment: Remove AST AnonTy"
This reverts commit 020cca8d36.
Revert "Ensure macros are not affected"
This reverts commit 12d18e4031.
Revert "Emit fewer errors on patterns with possible type ascription"
This reverts commit c847a01a3b.
Revert "Teach parser to understand fake anonymous enum syntax"
This reverts commit 2d82420665.
The check previously matched this, and suggested adding a missing
`struct`:
pub Foo(...):
It was probably intended to match this instead (semicolon instead of
colon):
pub Foo(...);
Fix invalid float literal suggestions when recovering an integer
Only suggest adding a zero to integers with a preceding dot when the change will result in a valid floating point literal.
For example, `.0x0` should not be turned into `0.0x0`.
r? nnethercote
Only suggest adding a zero to integers with a preceding dot when the change will
result in a valid floating point literal.
For example, `.0x0` should not be turned into `0.0x0`.
Improve unexpected close and mismatch delimiter hint in TokenTreesReader
Fixes#103882Fixes#68987Fixes#69259
The inner indentation mismatching will be covered by outer block, the new added function `report_error_prone_delim_block` will find out the error prone candidates for reporting.
Recover from more const arguments that are not wrapped in curly braces
Recover from some array, borrow, tuple & arithmetic expressions in const argument positions that lack curly braces and provide a suggestion to fix the issue continuing where #92884 left off. Examples of such expressions: `[]`, `[0]`, `[1, 2]`, `[0; 0xff]`, `&9`, `("", 0)` and `(1 + 2) * 3` (we previously did not recover from them).
I am not entirely happy with my current solution because the code that recovers from `[0]` (coinciding with a malformed slice type) and `[0; 0]` (coinciding with a malformed array type) is quite fragile as the aforementioned snippets are actually successfully parsed as types by `parse_ty` since it itself already recovers from them (returning `[⟨error⟩]` and `[⟨error⟩; 0]` respectively) meaning I have to manually look for `TyKind::Err`s and construct a separate diagnostic for the suggestion to attach to (thereby emitting two diagnostics in total).
Fixes#81698.
`@rustbot` label A-diagnostics
r? diagnostics
Teach parser to understand fake anonymous enum syntax
Parse `Ty | OtherTy` in function argument and return types.
Parse type ascription in top level patterns.
Minimally address #100741.
Adds an additional hint to failures where we encounter an else keyword
while we're parsing an if-let block.
This is likely that the user has accidentally mixed if-let and let...else
together.
--wip-- [skip ci]
get the generic text and put it int he suggestion, but suggestion not working on derive subdiagnostic
refactor away from derives and use span_suggestion() instead. Show's the correct(?) generic contents, but overwrites the fn name :(
x fmt
drop commented code and s/todo/fixme
get the correct diagnostic for functions, at least
x fmt
remove some debugs
remove format
remove debugs
remove useless change
remove useless change
remove legacy approach
correct lookahead + error message contains the ident name
fmt
refactor code
tests
add tests
remoev debug
remove comment
Recognise double-equals homoglyph
Recognise `⩵` as a homoglyph for `==`.
The first commit switches `char` to `&str`, as all previous homoglyphs corresponded to a single ASCII character, while the second implements the fix.
`@rustbot` label +A-diagnostics +A-parser
make error emitted on `impl &Trait` nicer
Fixes#106694
Turned out to be simpler than I thought, also added UI test.
Before: ([playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=9bda53271ef3a8886793cf427b8cea91))
```text
error: expected one of `:`, ``@`,` or `|`, found `)`
--> src/main.rs:2:22
|
2 | fn foo(_: impl &Trait) {}
| ^ expected one of `:`, ``@`,` or `|`
|
= note: anonymous parameters are removed in the 2018 edition (see RFC 1685)
help: if this is a parameter name, give it a type
|
2 | fn foo(_: impl Trait: &TypeName) {}
| ~~~~~~~~~~~~~~~~
help: if this is a type, explicitly ignore the parameter name
|
2 | fn foo(_: impl _: &Trait) {}
| ++
error: expected one of `!`, `(`, `)`, `,`, `?`, `for`, `~`, lifetime, or path, found `&`
--> src/main.rs:2:16
|
2 | fn foo(_: impl &Trait) {}
| -^ expected one of 9 possible tokens
| |
| help: missing `,`
error: expected one of `!`, `(`, `,`, `=`, `>`, `?`, `for`, `~`, lifetime, or path, found `&`
--> src/main.rs:3:11
|
3 | fn bar<T: &Trait>(_: T) {}
| ^ expected one of 10 possible tokens
```
After:
```text
error: expected a trait, found type
--> <anon>:2:16
|
2 | fn foo(_: impl &Trait) {}
| -^^^^^
| |
| help: consider removing the indirection
error: expected a trait, found type
--> <anon>:3:11
|
3 | fn bar<T: &Trait>(_: T) {}
| -^^^^^
| |
| help: consider removing the indirection
```
Emit only one nbsp error per file
Fixes#106101.
See https://github.com/rust-lang/rust/issues/106098 for an explanation of how someone would end up with a large number of these nbsp characters in their source code, which is why I think rustc needs to handle this specific case in a friendlier way.
