By making it an `EscapeError` instead of a `LitError`. This makes it
like the other errors produced when checking string literals contents,
e.g. for invalid escape sequences or bare CR chars.
NOTE: this means these errors are issued earlier, before expansion,
which changes behaviour. It will be possible to move the check back to
the later point if desired. If that happens, it's likely that all the
string literal contents checks will be delayed together.
One nice thing about this: the old approach had some code in
`report_lit_error` to calculate the span of the nul char from a range.
This code used a hardwired `+2` to account for the `c"` at the start of
a C string literal, but this should have changed to a `+3` for raw C
string literals to account for the `cr"`, which meant that the caret in
`cr"` nul error messages was one short of where it should have been. The
new approach doesn't need any of this and avoids the off-by-one error.
One consequence is that errors returned by
`maybe_new_parser_from_source_str` now must be consumed, so a bunch of
places that previously ignored those errors now cancel them. (Most of
them explicitly dropped the errors before. I guess that was to indicate
"we are explicitly ignoring these", though I'm not 100% sure.)
Two different lifetimes are conflated. This doesn't matter right now,
but needs to be fixed for the next commit to work. And the more
descriptive lifetime names make the code easier to read.
Each of these has a single call site: `source_file_to_parser`,
`try_file_to_source_file`, `file_to_source_file`. Having them separate
just makes the code longer and harder to read.
Also, `maybe_file_to_stream` doesn't need to be `pub`.
In #119606 I added them and used a `_mv` suffix, but that wasn't great.
A `with_` prefix has three different existing uses.
- Constructors, e.g. `Vec::with_capacity`.
- Wrappers that provide an environment to execute some code, e.g.
`with_session_globals`.
- Consuming chaining methods, e.g. `Span::with_{lo,hi,ctxt}`.
The third case is exactly what we want, so this commit changes
`DiagnosticBuilder::foo_mv` to `DiagnosticBuilder::with_foo`.
Thanks to @compiler-errors for the suggestion.
Because it takes an error code after the span. This avoids the confusing
overlap with the `DiagCtxt::struct_span_err` method, which doesn't take
an error code.
The existing uses are replaced in one of three ways.
- In a function that also has calls to `emit`, just rearrange the code
so that exactly one of `delay_as_bug` or `emit` is called on every
path.
- In a function returning a `DiagnosticBuilder`, use
`downgrade_to_delayed_bug`. That's good enough because it will get
emitted later anyway.
- In `unclosed_delim_err`, one set of errors is being replaced with
another set, so just cancel the original errors.
The old code was very hard to understand, involving an
`emit_without_consuming` call *and* a `delay_as_bug_without_consuming`
call.
With slight changes both calls can be avoided. Not creating the error
until later is crucial, as is the early return in the `if recovered`
block.
It took me some time to come up with this reworking -- it went through
intermediate states much further from the original code than this final
version -- and it's isn't obvious at a glance that it is equivalent. But
I think it is, and the unchanged test behaviour is good supporting
evidence.
The commit also changes `check_trailing_angle_brackets` to return
`Option<ErrorGuaranteed>`. This provides a stricter proof that it
emitted an error message than asserting `dcx.has_errors().is_some()`,
which would succeed if any error had previously been emitted anywhere.
It's not clear why this was here, because the created error is returned
as a normal error anyway.
Nor is it clear why removing the call works. The change doesn't affect
any tests; `tests/ui/parser/issues/issue-102182-impl-trait-recover.rs`
looks like the only test that could have been affected.
Instead of taking `seq` as a mutable reference,
`maybe_recover_struct_lit_bad_delims` now consumes `seq` on the recovery
path, and returns `seq` unchanged on the non-recovery path. The commit
also combines an `if` and a `match` to merge two identical paths.
Also change `recover_seq_parse_error` so it receives a `PErr` instead of
a `PResult`, because all the call sites now handle the `Ok`/`Err`
distinction themselves.
In this parsing recovery function, we only need to emit the previously
obtained error message and mark `expr` as erroneous in the case where we
actually recover.
This works for most of its call sites. This is nice, because `emit` very
much makes sense as a consuming operation -- indeed,
`DiagnosticBuilderState` exists to ensure no diagnostic is emitted
twice, but it uses runtime checks.
For the small number of call sites where a consuming emit doesn't work,
the commit adds `DiagnosticBuilder::emit_without_consuming`. (This will
be removed in subsequent commits.)
Likewise, `emit_unless` becomes consuming. And `delay_as_bug` becomes
consuming, while `delay_as_bug_without_consuming` is added (which will
also be removed in subsequent commits.)
All this requires significant changes to `DiagnosticBuilder`'s chaining
methods. Currently `DiagnosticBuilder` method chaining uses a
non-consuming `&mut self -> &mut Self` style, which allows chaining to
be used when the chain ends in `emit()`, like so:
```
struct_err(msg).span(span).emit();
```
But it doesn't work when producing a `DiagnosticBuilder` value,
requiring this:
```
let mut err = self.struct_err(msg);
err.span(span);
err
```
This style of chaining won't work with consuming `emit` though. For
that, we need to use to a `self -> Self` style. That also would allow
`DiagnosticBuilder` production to be chained, e.g.:
```
self.struct_err(msg).span(span)
```
However, removing the `&mut self -> &mut Self` style would require that
individual modifications of a `DiagnosticBuilder` go from this:
```
err.span(span);
```
to this:
```
err = err.span(span);
```
There are *many* such places. I have a high tolerance for tedious
refactorings, but even I gave up after a long time trying to convert
them all.
Instead, this commit has it both ways: the existing `&mut self -> Self`
chaining methods are kept, and new `self -> Self` chaining methods are
added, all of which have a `_mv` suffix (short for "move"). Changes to
the existing `forward!` macro lets this happen with very little
additional boilerplate code. I chose to add the suffix to the new
chaining methods rather than the existing ones, because the number of
changes required is much smaller that way.
This doubled chainging is a bit clumsy, but I think it is worthwhile
because it allows a *lot* of good things to subsequently happen. In this
commit, there are many `mut` qualifiers removed in places where
diagnostics are emitted without being modified. In subsequent commits:
- chaining can be used more, making the code more concise;
- more use of chaining also permits the removal of redundant diagnostic
APIs like `struct_err_with_code`, which can be replaced easily with
`struct_err` + `code_mv`;
- `emit_without_diagnostic` can be removed, which simplifies a lot of
machinery, removing the need for `DiagnosticBuilderState`.
rustc_span: More consistent span combination operations
Also add more tests for using `tt` in addition to `ident`, and some other minor tweaks, see individual commits.
This is a part of https://github.com/rust-lang/rust/pull/119412 that doesn't yet add side tables for metavariable spans.
Rollup of 10 pull requests
Successful merges:
- #118521 (Enable address sanitizer for MSVC targets using INFERASANLIBS linker flag)
- #119026 (std::net::bind using -1 for openbsd which in turn sets it to somaxconn.)
- #119195 (Make named_asm_labels lint not trigger on unicode and trigger on format args)
- #119204 (macro_rules: Less hacky heuristic for using `tt` metavariable spans)
- #119362 (Make `derive(Trait)` suggestion more accurate)
- #119397 (Recover parentheses in range patterns)
- #119417 (Uplift some miscellaneous coroutine-specific machinery into `check_closure`)
- #119539 (Fix typos)
- #119540 (Don't synthesize host effect args inside trait object types)
- #119555 (Add codegen test for RVO on MaybeUninit)
r? `@ghost`
`@rustbot` modify labels: rollup
`Diagnostic` has 40 methods that return `&mut Self` and could be
considered setters. Four of them have a `set_` prefix. This doesn't seem
necessary for a type that implements the builder pattern. This commit
removes the `set_` prefixes on those four methods.
This involves lots of breaking changes. There are two big changes that
force changes. The first is that the bitflag types now don't
automatically implement normal derive traits, so we need to derive them
manually.
Additionally, bitflags now have a hidden inner type by default, which
breaks our custom derives. The bitflags docs recommend using the impl
form in these cases, which I did.
Don't suggest writing a bodyless arm if the pattern can never be a never pattern
#118527 enabled arms to be bodyless for never patterns ; this PR removes the `,` and `}` suggestions for patterns that could never be never patterns.
Introduce `const Trait` (always-const trait bounds)
Feature `const_trait_impl` currently lacks a way to express “always const” trait bounds. This makes it impossible to define generic items like fns or structs which contain types that depend on const method calls (\*). While the final design and esp. the syntax of effects / keyword generics isn't set in stone, some version of “always const” trait bounds will very likely form a part of it. Further, their implementation is trivial thanks to the `effects` backbone.
Not sure if this needs t-lang sign-off though.
(\*):
```rs
#![feature(const_trait_impl, effects, generic_const_exprs)]
fn compute<T: const Trait>() -> Type<{ T::generate() }> { /*…*/ }
struct Store<T: const Trait>
where
Type<{ T::generate() }>:,
{
field: Type<{ T::generate() }>,
}
```
Lastly, “always const” trait bounds are a perfect fit for `generic_const_items`.
```rs
#![feature(const_trait_impl, effects, generic_const_items)]
const DEFAULT<T: const Default>: T = T::default();
```
Previously, we (oli, fee1-dead and I) wanted to reinterpret `~const Trait` as `const Trait` in generic const items which would've been quite surprising and not very generalizable.
Supersedes #117530.
---
cc `@oli-obk`
As discussed
r? fee1-dead (or compiler)
Clairify `ast::PatKind::Struct` presese of `..` by using an enum instead of a bool
The bool is mainly used for when a `..` is present, but it is also set on recovery to avoid errors. The doc comment not describes both of these cases.
See cee794ee98/compiler/rustc_parse/src/parser/pat.rs (L890-L897) for the only place this is constructed.
r? ``@compiler-errors``
`IntoDiagnostic` defaults to `ErrorGuaranteed`, because errors are the
most common diagnostic level. It makes sense to do likewise for the
closely-related (and much more widely used) `DiagnosticBuilder` type,
letting us write `DiagnosticBuilder<'a, ErrorGuaranteed>` as just
`DiagnosticBuilder<'a>`. This cuts over 200 lines of code due to many
multi-line things becoming single line things.
Add support for `for await` loops
This adds support for `for await` loops. This includes parsing, desugaring in AST->HIR lowering, and adding some support functions to the library.
Given a loop like:
```rust
for await i in iter {
...
}
```
this is desugared to something like:
```rust
let mut iter = iter.into_async_iter();
while let Some(i) = loop {
match core::pin::Pin::new(&mut iter).poll_next(cx) {
Poll::Ready(i) => break i,
Poll::Pending => yield,
}
} {
...
}
```
This PR also adds a basic `IntoAsyncIterator` trait. This is partly for symmetry with the way `Iterator` and `IntoIterator` work. The other reason is that for async iterators it's helpful to have a place apart from the data structure being iterated over to store state. `IntoAsyncIterator` gives us a good place to do this.
I've gated this feature behind `async_for_loop` and opened #118898 as the feature tracking issue.
r? `@compiler-errors`
Refactor AST trait bound modifiers
Instead of having two types to represent trait bound modifiers in the parser / the AST (`parser::ty::BoundModifiers` & `ast::TraitBoundModifier`), only to map one to the other later, just use `parser::ty::BoundModifiers` (moved & renamed to `ast::TraitBoundModifiers`).
The struct type is more extensible and easier to deal with (see [here](https://github.com/rust-lang/rust/pull/119099/files#r1430749981) and [here](https://github.com/rust-lang/rust/pull/119099/files#r1430752116) for context) since it more closely models what it represents: A compound of two kinds of modifiers, constness and polarity. Modeling this as an enum (the now removed `ast::TraitBoundModifier`) meant one had to add a new variant per *combination* of modifier kind, which simply isn't scalable and which lead to a lot of explicit non-DRY matches.
NB: `hir::TraitBoundModifier` being an enum is fine since HIR doesn't need to worry representing invalid modifier kind combinations as those get rejected during AST validation thereby immensely cutting down the number of possibilities.
Give `VariantData::Struct` named fields, to clairfy `recovered`.
Implements https://github.com/rust-lang/rust/pull/119121#discussion_r1431467066. Supersedes #119121
This way, it's clear what the bool fields means, instead of having to find where it's generated. Changes both ast and hir.
r? `@compiler-errors`
Add check for possible CStr literals in pre-2021
Fixes [#118654](https://github.com/rust-lang/rust/issues/118654)
Adds information to errors caused by possible CStr literals in pre-2021.
The lexer separates `c"str"` into two tokens if the edition is less than 2021, which later causes an error when parsing. This error now has a more helpful message that directs them to information about editions. However, the user might also have written `c "str"` in a later edition, so to not confuse people who _are_ using a recent edition, I also added a note about whitespace.
We could probably figure out exactly which scenario has been encountered by examining spans and editions, but I figured it would be better not to overcomplicate the creation of the error too much.
This is my first code PR and I tried to follow existing conventions as much as possible, but I probably missed something, so let me know!
This lets different error levels share the same return type from
`emit_*`.
- A lot of inconsistencies in the `DiagCtxt` API are removed.
- `Noted` is removed.
- `FatalAbort` is introduced for fatal errors (abort via `raise`),
replacing the `EmissionGuarantee` impl for `!`.
- `Bug` is renamed `BugAbort` (to avoid clashing with `Level::Bug` and
to mirror `FatalAbort`), and modified to work in the new way with bug
errors (abort via panic).
- Various diagnostic creators and emitters updated to the new, better
signatures. Note that `DiagCtxt::bug` no longer needs to call
`panic_any`, because `emit` handles that.
Also shorten the obnoxiously long
`diagnostic_builder_emit_producing_guarantee` name.
And make all hand-written `IntoDiagnostic` impls generic, by using
`DiagnosticBuilder::new(dcx, level, ...)` instead of e.g.
`dcx.struct_err(...)`.
This means the `create_*` functions are the source of the error level.
This change will let us remove `struct_diagnostic`.
Note: `#[rustc_lint_diagnostics]` is added to `DiagnosticBuilder::new`,
it's necessary to pass diagnostics tests now that it's used in
`into_diagnostic` functions.
This commit replaces this pattern:
```
err.into_diagnostic(dcx)
```
with this pattern:
```
dcx.create_err(err)
```
in a lot of places.
It's a little shorter, makes the error level explicit, avoids some
`IntoDiagnostic` imports, and is a necessary prerequisite for the next
commit which will add a `level` arg to `into_diagnostic`.
This requires adding `track_caller` on `create_err` to avoid mucking up
the output of `tests/ui/track-diagnostics/track4.rs`. It probably should
have been there already.
Currently, `emit_diagnostic` takes `&mut self`.
This commit changes it so `emit_diagnostic` takes `self` and the new
`emit_diagnostic_without_consuming` function takes `&mut self`.
I find the distinction useful. The former case is much more common, and
avoids a bunch of `mut` and `&mut` occurrences. We can also restrict the
latter with `pub(crate)` which is nice.
It's unclear why this is used here. All entries in the third column of
`UNICODE_ARRAY` are covered by `ASCII_ARRAY`, so if the lookup fails
it's a genuine compiler bug. It was added way back in #29837, for no
clear reason.
This commit changes it to `span_bug`, which is more typical.
It's necessary for `derive(Diagnostic)`, but is best avoided elsewhere
because there are clearer alternatives.
This required adding `Handler::struct_almost_fatal`.
Actually parse async gen blocks correctly
1. I got the control flow in `parse_expr_bottom` messed up, and obviously forgot a test for `async gen`, so we weren't actually ever parsing it correctly.
2. I forgot to gate the span for `async gen {}`, so even if we did parse it, we wouldn't have correctly denied it in `cfg(FALSE)`.
r? eholk
The `span` arg is described in a comment as "interior span of the
literal, without quotes", which is incorrect. It's actually the span of
the error part of the literal, corresponding to `range`.
This commit renames `span` and `span_without_quotes` to make things
clearer, and fixes the erroneous comment.
Correctly gate the parsing of match arms without body
https://github.com/rust-lang/rust/pull/118527 accidentally allowed the following to parse on stable:
```rust
match Some(0) {
None => { foo(); }
#[cfg(FALSE)]
Some(_)
}
```
This fixes that oversight. The way I choose which error to emit is the best I could think of, I'm open if you know a better way.
r? `@petrochenkov` since you're the one who noticed
Attribute values must be literals. The error you get when that doesn't
hold is pretty bad, e.g.:
```
unexpected expression: 1 + 1
```
You also get the same error if the attribute value is a literal, but an
invalid literal, e.g.:
```
unexpected expression: "foo"suffix
```
This commit does two things.
- Changes the error message to "attribute value must be a literal",
which gives a better idea of what the problem is and how to fix it. It
also no longer prints the invalid expression, because the carets below
highlight it anyway.
- Separates the "not a literal" case from the "invalid literal" case.
Which means invalid literals now get the specific error at the literal
level, rather than at the attribute level.
This is an extension of the previous commit. It means the output of
something like this:
```
stringify!(let a: Vec<u32> = vec![];)
```
goes from this:
```
let a: Vec<u32> = vec![] ;
```
With this PR, it now produces this string:
```
let a: Vec<u32> = vec![];
```
`tokenstream::Spacing` appears on all `TokenTree::Token` instances,
both punct and non-punct. Its current usage:
- `Joint` means "can join with the next token *and* that token is a
punct".
- `Alone` means "cannot join with the next token *or* can join with the
next token but that token is not a punct".
The fact that `Alone` is used for two different cases is awkward.
This commit augments `tokenstream::Spacing` with a new variant
`JointHidden`, resulting in:
- `Joint` means "can join with the next token *and* that token is a
punct".
- `JointHidden` means "can join with the next token *and* that token is a
not a punct".
- `Alone` means "cannot join with the next token".
This *drastically* improves the output of `print_tts`. For example,
this:
```
stringify!(let a: Vec<u32> = vec![];)
```
currently produces this string:
```
let a : Vec < u32 > = vec! [] ;
```
With this PR, it now produces this string:
```
let a: Vec<u32> = vec![] ;
```
(The space after the `]` is because `TokenTree::Delimited` currently
doesn't have spacing information. The subsequent commit fixes this.)
The new `print_tts` doesn't replicate original code perfectly. E.g.
multiple space characters will be condensed into a single space
character. But it's much improved.
`print_tts` still produces the old, uglier output for code produced by
proc macros. Because we have to translate the generated code from
`proc_macro::Spacing` to the more expressive `token::Spacing`, which
results in too much `proc_macro::Along` usage and no
`proc_macro::JointHidden` usage. So `space_between` still exists and
is used by `print_tts` in conjunction with the `Spacing` field.
This change will also help with the removal of `Token::Interpolated`.
Currently interpolated tokens are pretty-printed nicely via AST pretty
printing. `Token::Interpolated` removal will mean they get printed with
`print_tts`. Without this change, that would result in much uglier
output for code produced by decl macro expansions. With this change, AST
pretty printing and `print_tts` produce similar results.
The commit also tweaks the comments on `proc_macro::Spacing`. In
particular, it refers to "compound tokens" rather than "multi-char
operators" because lifetimes aren't operators.
detects redundant imports that can be eliminated.
for #117772 :
In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
Introduce support for `async gen` blocks
I'm delighted to demonstrate that `async gen` block are not very difficult to support. They're simply coroutines that yield `Poll<Option<T>>` and return `()`.
**This PR is WIP and in draft mode for now** -- I'm mostly putting it up to show folks that it's possible. This PR needs a lang-team experiment associated with it or possible an RFC, since I don't think it falls under the jurisdiction of the `gen` RFC that was recently authored by oli (https://github.com/rust-lang/rfcs/pull/3513, https://github.com/rust-lang/rust/issues/117078).
### Technical note on the pre-generator-transform yield type:
The reason that the underlying coroutines yield `Poll<Option<T>>` and not `Poll<T>` (which would make more sense, IMO, for the pre-transformed coroutine), is because the `TransformVisitor` that is used to turn coroutines into built-in state machine functions would have to destructure and reconstruct the latter into the former, which requires at least inserting a new basic block (for a `switchInt` terminator, to match on the `Poll` discriminant).
This does mean that the desugaring (at the `rustc_ast_lowering` level) of `async gen` blocks is a bit more involved. However, since we already need to intercept both `.await` and `yield` operators, I don't consider it much of a technical burden.
r? `@ghost`
never_patterns: Parse match arms with no body
Never patterns are meant to signal unreachable cases, and thus don't take bodies:
```rust
let ptr: *const Option<!> = ...;
match *ptr {
None => { foo(); }
Some(!),
}
```
This PR makes rustc accept the above, and enforces that an arm has a body xor is a never pattern. This affects parsing of match arms even with the feature off, so this is delicate. (Plus this is my first non-trivial change to the parser).
~~The last commit is optional; it introduces a bit of churn to allow the new suggestions to be machine-applicable. There may be a better solution? I'm not sure.~~ EDIT: I removed that commit
r? `@compiler-errors`
discard invalid spans in external blocks
Fixes#116203
This PR has discarded the invalid `const_span`, thereby making the format more neat.
r? ``@Nilstrieb``
Add support for `gen fn`
This builds on #116447 to add support for `gen fn` functions. For the most part we follow the same approach as desugaring `async fn`, but replacing `Future` with `Iterator` and `async {}` with `gen {}` for the body.
The version implemented here uses the return type of a `gen fn` as the yield type. For example:
```rust
gen fn count_to_three() -> i32 {
yield 1;
yield 2;
yield 3;
}
```
In the future, I think we should experiment with a syntax like `gen fn count_to_three() yield i32 { ... }`, but that can go in another PR.
cc `@oli-obk` `@compiler-errors`
Tweak unclosed generics errors
Remove unnecessary span label for parse errors that already have a suggestion.
Provide structured suggestion to close generics in more cases.
These impls are all needed for just a single `IntoDiagnostic` type, not
a family of them.
Note that `ErrorGuaranteed` is the default type parameter for
`IntoDiagnostic`.
Because a macro invocation can expand to a never pattern, we can't rule
out a `arm!(),` arm at parse time. Instead we detect that case at
expansion time, if the macro tries to output a pattern followed by `=>`.
Stabilize C string literals
RFC: https://rust-lang.github.io/rfcs/3348-c-str-literal.html
Tracking issue: https://github.com/rust-lang/rust/issues/105723
Documentation PR (reference manual): https://github.com/rust-lang/reference/pull/1423
# Stabilization report
Stabilizes C string and raw C string literals (`c"..."` and `cr#"..."#`), which are expressions of type [`&CStr`](https://doc.rust-lang.org/stable/core/ffi/struct.CStr.html). Both new literals require Rust edition 2021 or later.
```rust
const HELLO: &core::ffi::CStr = c"Hello, world!";
```
C strings may contain any byte other than `NUL` (`b'\x00'`), and their in-memory representation is guaranteed to end with `NUL`.
## Implementation
Originally implemented by PR https://github.com/rust-lang/rust/pull/108801, which was reverted due to unintentional changes to lexer behavior in Rust editions < 2021.
The current implementation landed in PR https://github.com/rust-lang/rust/pull/113476, which restricts C string literals to Rust edition >= 2021.
## Resolutions to open questions from the RFC
* Adding C character literals (`c'.'`) of type `c_char` is not part of this feature.
* Support for `c"..."` literals does not prevent `c'.'` literals from being added in the future.
* C string literals should not be blocked on making `&CStr` a thin pointer.
* It's possible to declare constant expressions of type `&'static CStr` in stable Rust (as of v1.59), so C string literals are not adding additional coupling on the internal representation of `CStr`.
* The unstable `concat_bytes!` macro should not accept `c"..."` literals.
* C strings have two equally valid `&[u8]` representations (with or without terminal `NUL`), so allowing them to be used in `concat_bytes!` would be ambiguous.
* Adding a type to represent C strings containing valid UTF-8 is not part of this feature.
* Support for a hypothetical `&Utf8CStr` may be explored in the future, should such a type be added to Rust.
Suggest `let` or `==` on typo'd let-chain
When encountering a bare assignment in a let-chain, suggest turning the
assignment into a `let` expression or an equality check.
```
error: expected expression, found `let` statement
--> $DIR/bad-if-let-suggestion.rs:5:8
|
LL | if let x = 1 && i = 2 {}
| ^^^^^^^^^
|
= note: only supported directly in conditions of `if` and `while` expressions
help: you might have meant to continue the let-chain
|
LL | if let x = 1 && let i = 2 {}
| +++
help: you might have meant to compare for equality
|
LL | if let x = 1 && i == 2 {}
| +
```
Add `never_patterns` feature gate
This PR adds the feature gate and most basic parsing for the experimental `never_patterns` feature. See the tracking issue (https://github.com/rust-lang/rust/issues/118155) for details on the experiment.
`@scottmcm` has agreed to be my lang-team liaison for this experiment.
Remove HIR opkinds
`hir::BinOp`, `hir::BinOpKind`, and `hir::UnOp` are identical to `ast::BinOp`, `ast::BinOpKind`, and `ast::UnOp`, respectively. This seems silly, so this PR removes the HIR ones. (A re-export lets the AST ones be referred to using a `hir::` qualifier, which avoids renaming churn.)
r? `@cjgillot`
When encountering a bare assignment in a let-chain, suggest turning the
assignment into a `let` expression or an equality check.
```
error: expected expression, found `let` statement
--> $DIR/bad-if-let-suggestion.rs:5:8
|
LL | if let x = 1 && i = 2 {}
| ^^^^^^^^^
|
= note: only supported directly in conditions of `if` and `while` expressions
help: you might have meant to continue the let-chain
|
LL | if let x = 1 && let i = 2 {}
| +++
help: you might have meant to compare for equality
|
LL | if let x = 1 && i == 2 {}
| +
```
- Rename them both `as_str`, which is the typical name for a function
that returns a `&str`. (`to_string` is appropriate for functions
returning `String` or maybe `Cow<'a, str>`.)
- Change `UnOp::as_str` from an associated function (weird!) to a
method.
- Avoid needless `self` dereferences.
Currently we always do this:
```
use rustc_fluent_macro::fluent_messages;
...
fluent_messages! { "./example.ftl" }
```
But there is no need, we can just do this everywhere:
```
rustc_fluent_macro::fluent_messages! { "./example.ftl" }
```
which is shorter.
The `fluent_messages!` macro produces uses of
`crate::{D,Subd}iagnosticMessage`, which means that every crate using
the macro must have this import:
```
use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
```
This commit changes the macro to instead use
`rustc_errors::{D,Subd}iagnosticMessage`, which avoids the need for the
imports.
Recover `dyn` and `impl` after `for<...>`
Recover `dyn` and `impl` after `for<...>` in types. Reuses the logic for parsing bare trait objects, so it doesn't fix cases like `for<'a> dyn Trait + dyn Trait` or anything, but that seems somewhat of a different issue.
Parsing recovery logic is a bit involved, but I couldn't find a way to simplify it.
Fixes#117882
More detail when expecting expression but encountering bad macro argument
On nested macro invocations where the same macro fragment changes fragment type from one to the next, point at the chain of invocations and at the macro fragment definition place, explaining that the change has occurred.
Fix#71039.
```
error: expected expression, found pattern `1 + 1`
--> $DIR/trace_faulty_macros.rs:49:37
|
LL | (let $p:pat = $e:expr) => {test!(($p,$e))};
| ------- -- this is interpreted as expression, but it is expected to be pattern
| |
| this macro fragment matcher is expression
...
LL | (($p:pat, $e:pat)) => {let $p = $e;};
| ------ ^^ expected expression
| |
| this macro fragment matcher is pattern
...
LL | test!(let x = 1+1);
| ------------------
| | |
| | this is expected to be expression
| in this macro invocation
|
= note: when forwarding a matched fragment to another macro-by-example, matchers in the second macro will see an opaque AST of the fragment type, not the underlying tokens
= note: this error originates in the macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)
```
Give a better diagnostic for missing parens in Fn* bounds
Fixes#108109
It would be nice to try and recover here, but I'm not sure it's worth the effort, especially as the bounds on the recovered function would be incorrect.
Most notably, this commit changes the `pub use crate::*;` in that file
to `use crate::*;`. This requires a lot of `use` items in other crates
to be adjusted, because everything defined within `rustc_span::*` was
also available via `rustc_span::source_map::*`, which is bizarre.
The commit also removes `SourceMap::span_to_relative_line_string`, which
is unused.
Account for `ref` and `mut` in the wrong place for pattern ident renaming
If the user writes `S { ref field: name }` instead of `S { field: ref name }`, we suggest the correct code.
Fix#72298.
Rollup of 7 pull requests
Successful merges:
- #116862 (Detect when trait is implemented for type and suggest importing it)
- #117389 (Some diagnostics improvements of `gen` blocks)
- #117396 (Don't treat closures/coroutine types as part of the public API)
- #117398 (Correctly handle nested or-patterns in exhaustiveness)
- #117403 (Poison check_well_formed if method receivers are invalid to prevent typeck from running on it)
- #117411 (Improve some diagnostics around `?Trait` bounds)
- #117414 (Don't normalize to an un-revealed opaque when we hit the recursion limit)
r? `@ghost`
`@rustbot` modify labels: rollup
- Sort dependencies and features sections.
- Add `tidy` markers to the sorted sections so they stay sorted.
- Remove empty `[lib`] sections.
- Remove "See more keys..." comments.
Excluded files:
- rustc_codegen_{cranelift,gcc}, because they're external.
- rustc_lexer, because it has external use.
- stable_mir, because it has external use.
Implement `gen` blocks in the 2024 edition
Coroutines tracking issue https://github.com/rust-lang/rust/issues/43122
`gen` block tracking issue https://github.com/rust-lang/rust/issues/117078
This PR implements `gen` blocks that implement `Iterator`. Most of the logic with `async` blocks is shared, and thus I renamed various types that were referring to `async` specifically.
An example usage of `gen` blocks is
```rust
fn foo() -> impl Iterator<Item = i32> {
gen {
yield 42;
for i in 5..18 {
if i.is_even() { continue }
yield i * 2;
}
}
}
```
The limitations (to be resolved) of the implementation are listed in the tracking issue
Properly restore snapshot when failing to recover parsing ternary
If the recovery parsed an expression, then failed to eat a `:`, it would return `false` without restoring the snapshot. Fix this by always restoring the snapshot when returning `false`.
Draft for now because I'd like to try and improve this recovery further.
Fixes#117208
When encountering code like `f::<f::<f::<f::<f::<f::<f::<f::<...` with
unmatched closing angle brackets, add a linear check that avoids the
exponential behavior of the parse recovery mechanism.
Fix#117080.
The new place makes more sense and covers more cases beyond individual
statements.
```
error: expected one of `.`, `;`, `?`, `else`, or an operator, found doc comment `//!foo
--> $DIR/doc-comment-in-stmt.rs:25:22
|
LL | let y = x.max(1) //!foo
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected one of `.`, `;`, `?`, `else`, or an operator
|
help: add a space before `!` to write a regular comment
|
LL | let y = x.max(1) // !foo
| +
```
Fix#65329.
Format all the let-chains in compiler crates
Since rust-lang/rustfmt#5910 has landed, soon we will have support for formatting let-chains (as soon as rustfmt syncs and beta gets bumped).
This PR applies the changes [from master rustfmt to rust-lang/rust eagerly](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/out.20formatting.20of.20prs/near/374997516), so that the next beta bump does not have to deal with a 200+ file diff and can remain concerned with other things like `cfg(bootstrap)` -- #113637 was a pain to land, for example, because of let-else.
I will also add this commit to the ignore list after it has landed.
The commands that were run -- I'm not great at bash-foo, but this applies rustfmt to every compiler crate, and then reverts the two crates that should probably be formatted out-of-tree.
```
~/rustfmt $ ls -1d ~/rust/compiler/* | xargs -I@ cargo run --bin rustfmt -- `@/src/lib.rs` --config-path ~/rust --edition=2021 # format all of the compiler crates
~/rust $ git checkout HEAD -- compiler/rustc_codegen_{gcc,cranelift} # revert changes to cg-gcc and cg-clif
```
cc `@rust-lang/rustfmt`
r? `@WaffleLapkin` or `@Nilstrieb` who said they may be able to review this purely mechanical PR :>
cc `@Mark-Simulacrum` and `@petrochenkov,` who had some thoughts on the order of operations with big formatting changes in https://github.com/rust-lang/rust/pull/95262#issue-1178993801. I think the situation has changed since then, given that let-chains support exists on master rustfmt now, and I'm fairly confident that this formatting PR should land even if *bootstrap* rustfmt doesn't yet format let-chains in order to lessen the burden of the next beta bump.
Detect ruby-style closure in parser
When parsing a closure without a body that is surrounded by a block, suggest moving the opening brace after the closure head.
Fix#116608.
Detect missing `=>` after match guard during parsing
```
error: expected one of `,`, `:`, or `}`, found `.`
--> $DIR/missing-fat-arrow.rs:25:14
|
LL | Some(a) if a.value == b {
| - while parsing this struct
LL | a.value = 1;
| -^ expected one of `,`, `:`, or `}`
| |
| while parsing this struct field
|
help: try naming a field
|
LL | a: a.value = 1;
| ++
help: you might have meant to start a match arm after the match guard
|
LL | Some(a) if a.value == b => {
| ++
```
Fix#78585.
```
error: expected one of `,`, `:`, or `}`, found `.`
--> $DIR/missing-fat-arrow.rs:25:14
|
LL | Some(a) if a.value == b {
| - while parsing this struct
LL | a.value = 1;
| -^ expected one of `,`, `:`, or `}`
| |
| while parsing this struct field
|
help: try naming a field
|
LL | a: a.value = 1;
| ++
help: you might have meant to start a match arm after the match guard
|
LL | Some(a) if a.value == b => {
| ++
```
Fix#78585.
Improve invalid let expression handling
- Move all of the checks for valid let expression positions to parsing.
- Add a field to ExprKind::Let in AST/HIR to mark whether it's in a valid location.
- Suppress some later errors and MIR construction for invalid let expressions.
- Fix a (drop) scope issue that was also responsible for #104172.
Fixes#104172Fixes#104868
- Add doc comment to new type
- Restore "only supported directly in conditions of `if` and `while` expressions" note
- Rename variant with clearer name
Previously some invalid let expressions would result in both a feature
error and a parsing error. Avoid this and ensure that we only emit the
parsing error when this happens.
There was an incomplete version of the check in parsing and a second
version in AST validation. This meant that some, but not all, invalid
uses were allowed inside macros/disabled cfgs. It also means that later
passes have a hard time knowing when the let expression is in a valid
location, sometimes causing ICEs.
- Add a field to ExprKind::Let in AST/HIR to mark whether it's in a
valid location.
- Suppress later errors and MIR construction for invalid let
expressions.
Add explanatory note to 'expected item' error
Fixes#113110
It changes the diagnostic from this:
```
error: expected item, found `5`
--> ../test.rs:1:1
|
1 | 5
| ^ expected item
```
to this:
```
error: expected item, found `5`
--> ../test.rs:1:1
|
1 | 5
| ^ expected item
|
= note: items are things that can appear at the root of a module
= note: for a full list see https://doc.rust-lang.org/reference/items.html
```
It uses `once` chained with `(0..self.num_calls).map(...)` followed by
`.take(self.num_calls`. I found this hard to read. It's simpler to just
use `repeat_with`.
Make if let guard parsing consistent with normal guards
- Add tests that struct expressions are not allowed in `if let` and `while let` (no change, consistent with `if` and `while`)
- Allow struct expressions in `if let` guards (consistent with `if` guards).
r? `@cjgillot`
Closes#93817
cc #51114
suggest removing `impl` in generic trait bound position
rustc already does this recovery in type param position (`<T: impl Trait>` -> `<T: Trait>`).
This PR also adds that suggestion in trait bound position (e.g. `where T: impl Trait` or `trait Trait { type Assoc: impl Trait; }`)
parser: not insert dummy field in struct
Fixes#114636
This PR eliminates the dummy field, initially introduced in #113999, thereby enabling unrestricted use of `ident.unwrap()`. A side effect of this action is that we can only report the error of the first macro invocation field within the struct node.
An alternative solution might be giving a virtual name to the macro, but it appears more complex.(https://github.com/rust-lang/rust/issues/114636#issuecomment-1670228715). Furthermore, if you think https://github.com/rust-lang/rust/issues/114636#issuecomment-1670228715 is a better solution, feel free to close this PR.
Parse unnamed fields and anonymous structs or unions (no-recovery)
It is part of #114782 which implements #49804. Only parse anonymous structs or unions in struct field definition positions.
r? `@petrochenkov`
Anonymous structs or unions are only allowed in struct field
definitions.
Co-authored-by: carbotaniuman <41451839+carbotaniuman@users.noreply.github.com>
`Nonterminal`-related cleanups
In #114647 I am trying to remove `Nonterminal`. It has a number of preliminary cleanups that are worth merging even if #114647 doesn't merge, so let's do them in this PR.
r? `@petrochenkov`
It's much more complicated than it needs to be, and it doesn't modify
the expression. We can do the `Result` handling outside of it, and
change it to just return a span.
Also fix an errant comma that makes the comment hard to read.
Fix suggestion for attempting to define a string with single quotes
Currently attempting to compile `fn main() { let _ = '\\"'; }` will result in the following error message:
```
error: character literal may only contain one codepoint
--> src/main.rs:1:21
|
1 | fn main() { let _ = '\\"'; }
| ^^^^^
|
help: if you meant to write a `str` literal, use double quotes
|
1 | fn main() { let _ = "\\""; }
| ~~~~~
```
The suggestion is invalid as it fails to escape the `"`. This PR fixes the suggestion so that it now reads:
```
help: if you meant to write a `str` literal, use double quotes
|
1 | fn main() { let _ = "\\\""; }
| ~~~~~~
```
The relevant test is also updated to ensure that this does not regress in future.
Improve spans for indexing expressions
fixes#114388
Indexing is similar to method calls in having an arbitrary left-hand-side and then something on the right, which is the main part of the expression. Method calls already have a span for that right part, but indexing does not. This means that long method chains that use indexing have really bad spans, especially when the indexing panics and that span in coverted into a panic location.
This does the same thing as method calls for the AST and HIR, storing an extra span which is then put into the `fn_span` field in THIR.
r? compiler-errors
Indexing is similar to method calls in having an arbitrary
left-hand-side and then something on the right, which is the main part
of the expression. Method calls already have a span for that right part,
but indexing does not. This means that long method chains that use
indexing have really bad spans, especially when the indexing panics and
that span in coverted into a panic location.
This does the same thing as method calls for the AST and HIR, storing an
extra span which is then put into the `fn_span` field in THIR.
Add `internal_features` lint
Implements https://github.com/rust-lang/compiler-team/issues/596
Also requires some more test blessing for codegen tests etc
`@jyn514` had the idea of just `allow`ing the lint by default in the test suite. I'm not sure whether this is a good idea, but it's definitely one worth considering. Additional input encouraged.
parser: more friendly hints for handling `async move` in the 2015 edition
Fixes#114219
An error is emitted when encountering an async move block in the 2015 edition.
Another appropriate location to raise an error is after executing [let path = this.parse_path(PathStyle::Expr)?](https://github.com/rust-lang/rust/blob/master/compiler/rustc_parse/src/parser/stmt.rs#L152), but it seems somewhat premature to invoke `create_err` at that stage.
It lints against features that are inteded to be internal to the
compiler and standard library. Implements MCP #596.
We allow `internal_features` in the standard library and compiler as those
use many features and this _is_ the standard library from the "internal to the compiler and
standard library" after all.
Marking some features as internal wasn't exactly the most scientific approach, I just marked some
mostly obvious features. While there is a categorization in the macro,
it's not very well upheld (should probably be fixed in another PR).
We always pass `-Ainternal_features` in the testsuite
About 400 UI tests and several other tests use internal features.
Instead of throwing the attribute on each one, just always allow them.
There's nothing wrong with testing internal features^^
It's the same as `Delimiter`, minus the `Invisible` variant. I'm
generally in favour of using types to make impossible states
unrepresentable, but this one feels very low-value, and the conversions
between the two types are annoying and confusing.
Look at the change in `src/tools/rustfmt/src/expr.rs` for an example:
the old code converted from `MacDelimiter` to `Delimiter` and back
again, for no good reason. This suggests the author was confused about
the types.
Similar to the last commit, it's more of a `Parser`-level concern than a
`TokenCursor`-level concern. And the struct size reductions are nice.
After this change, `TokenCursor` is as minimal as possible (two fields
and two methods) which is nice.
It's more of a `Parser`-level concern than a `TokenCursor`-level
concern. Also, `num_bump_calls` is a more accurate name, because it's
incremented in `Parser::bump`.
Move doc comment desugaring out of `TokenCursor`.
It's awkward that `TokenCursor` sometimes desugars doc comments on the fly, but usually doesn't.
r? `@petrochenkov`
`TokenCursor` currently does doc comment desugaring on the fly, if the
`desugar_doc_comment` field is set. This requires also modifying the
token stream on the fly with `replace_prev_and_rewind`.
This commit moves the doc comment desugaring out of `TokenCursor`, by
introducing a new `TokenStream::desugar_doc_comment` method. This
separation of desugaring and iterating makes the code nicer.
Fix invalid suggestion for mismatched types in closure arguments
This PR fixes the invalid suggestion for mismatched types in closure arguments.
The invalid suggestion came from a wrongly created span in the parser for closure arguments that don't have a type specified. Specifically, the span in this case was the last token span, but in the case of tuples, the span represented the last parenthesis instead of the whole tuple, which is fixed by taking the more accurate span of the pattern.
There is one unfortunate downside of this fix, it worsens even more the diagnostic for mismatched types in closure args without an explicit type. This happens because there is no correct span for implied inferred type. I tried also fixing this but it's a rabbit hole.
Fixes https://github.com/rust-lang/rust/issues/114180
The invalid suggestion came from a wrongly created span in `rustc_parse'
for closure arguments that didn't have a type specified. Specifically,
the span in this case was the last token span, but in the case of
tuples, the span represented the last parenthesis instead of the whole
tuple, which is fixed by taking the more accurate span of the pattern.
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.
Emit a single error for contiguous sequences of unknown tokens
Closes#106101
On encountering a sequence of identical source characters which are unknown tokens, note the amount of subsequent characters and advance past them silently. The old behavior was to emit an error and 'help' note for every single one.
`@rustbot` label +A-diagnostics +A-parser
Recover from where clauses placed before tuple struct bodies
Open to any suggestions regarding the phrasing of the diagnostic.
Fixes#100790.
`@rustbot` label A-diagnostics
r? diagnostics
Rollup of 9 pull requests
Successful merges:
- #104531 (Provide a better error and a suggestion for `Fn` traits with lifetime params)
- #105899 (`./x doc library --open` opens `std`)
- #106190 (Account for multiple multiline spans with empty padding)
- #106202 (Trim more paths in obligation types)
- #106234 (rustdoc: simplify settings, help, and copy button CSS by not reusing)
- #106236 (docs/test: add docs and a UI test for `E0514` and `E0519`)
- #106259 (Update Clippy)
- #106260 (Fix index out of bounds issues in rustdoc)
- #106263 (Formatter should not try to format non-Rust files)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
