Feature-gate `mut ref` patterns in struct pattern field shorthand
Tracking issue for `mut_ref` (and other parts of Match Ergonomics 2024): https://github.com/rust-lang/rust/issues/123076https://github.com/rust-lang/rust/pull/123080 introduced `mut ref`[^1] patterns (for by-reference bindings where the binding itself is mutable), feature-gated behind the `mut_ref` feature, except for in struct pattern shorthand, where the feature gating was missing. Thus, `mut ref` patterns in struct pattern shorthand has been unintentionally stable for ~18 months (since 1.79.0 ([compiler explorer](https://rust.godbolt.org/z/4WTrvhboT))).
This PR adds feature-gating for `mut ref` patterns in struct pattern shorthand. Since this is reverting an accidental stabilization, this probably needs a crater run and a T-lang FCP?
Some alternative possibilities:
* Do nothing (let the inconsistency exist until `feature(mut_ref)` is stabilized)
* Document the existing behavior
* Do a FCW instead of fully feature-gating
* Stabilize `feature(mut_ref)`
CC https://github.com/rust-lang/rust/pull/123080#issuecomment-3746793632
CC @Nadrieril
[^1]: everything in this description also applies analogously to `mut ref mut` patterns.
From the `parser` module to the `errors` module, which is where most of
its uses are.
This means the `errors` module no longer depends on the `parser` module,
removing a cyclic dependency between the two modules.
Every diagnostic struct in `rustc_parse` is in the `errors` module,
except for `ForbiddenLetReason` and `MisspelledKw`. There's no good
reason for this, and presumably it is just an accidental inconsistency.
This commit moves them into `errors`.
Based on earlier work by León Orell Valerian Liehr.
Co-authored-by: León Orell Valerian Liehr <me@fmease.dev>
Signed-off-by: Usman Akinyemi <uniqueusman@archlinux>
`const` blocks as a `mod` item
Tracking issue: rust-lang/rust#149226
This adds support for writing `const { ... }` as an item in a module. In the current implementation, this is a unique AST item that gets lowered to `const _: () = const { ... };` in HIR.
rustfmt support included.
TODO:
- `pub const { ... }` does not make sense (see rust-lang/rust#147136). Reject it. Should this be rejected by the parser or smth?
- Improve diagnostics (preferably they should not mention the fake `_` ident).
Do not recover from `Trait()` if generic list is unterminated
If we encounter `fn foo<T: Trait()`, the recovery logic would it as if `Trait` was intended to use the Fn-like trait syntax, but if we don't know for certain that we've parsed a full trait bound (`fn foo<T: Trait()>`), we bail from the recovery as more likely there could have been a missing closing `>` and the `(` corresponds to the start of the fn parameter list.
Fixrust-lang/rust#141436.
If we encounter `fn foo<T: Trait()`, the recovery logic would it as if `Trait` was intended to use the Fn-like trait syntax, but if we don't know for certain that we've parsed a full trait bound (`fn foo<T: Trait()>`), we bail from the recovery as more likely there could have been a missing closing `>` and the `(` corresponds to the start of the fn parameter list.
Recover parse gracefully from `<const N>`
When a const param doesn't have a `: Type`, recover the parser state and provide a structured suggestion. This not only provides guidance on what was missing, but it also makes subsuequent errors to be emitted that would otherwise be silenced.
```
error: expected `:`, found `>`
--> $DIR/incorrect-const-param.rs:26:16
|
LL | impl<T, const N> From<[T; N]> for VecWrapper<T>
| ^ expected `:`
|
help: you might have meant to write the type of the const parameter here
|
LL | impl<T, const N: /* Type */> From<[T; N]> for VecWrapper<T>
| ++++++++++++
```
r? @fmease
Follow up to rust-lang/rust#151077. Fixrust-lang/rust#84327.
Don't try to recover keyword as non-keyword identifier
Fixesrust-lang/rust#149692.
On beta after rust-lang/rust#146978, we ICE on
```rs
macro_rules! m {
($id:item()) => {}
}
m!(Self());
```
where `Self` in the macro invocation is a keyword not a "normal" identifier, while attempting to recover an missing keyword before an identifier. Except, `Self` *is* a keyword, so trying to parse that as a non-reserved identifier expectedly fails.
I suspect rust-lang/rust#146978 merely unmasked a possible code path to hit this case; this logic has been so for a good while. Previously, on stable, the error message looks something like
```rs
error: expected identifier, found keyword `Self`
--> src/lib.rs:5:4
|
5 | m!(Self());
| ^^^^ expected identifier, found keyword
error: missing `fn` or `struct` for function or struct definition
--> src/lib.rs:5:4
|
2 | ($id:item()) => {}
| -------- while parsing argument for this `item` macro fragment
...
5 | m!(Self());
| ^^^^
|
help: if you meant to call a macro, try
|
5 | m!(Self!());
| +
```
I considered restoring this diagnostic, but I'm not super convinced it's worth the complexity (and to me, it's not super clear what the user actually intended here).
When a const param doesn't have a `: Type`, recover the parser state and provide a structured suggestion. This not only provides guidance on what was missing, but it also makes subsuequent errors to be emitted that would otherwise be silenced.
```
error: expected `:`, found `>`
--> $DIR/incorrect-const-param.rs:26:16
|
LL | impl<T, const N> From<[T; N]> for VecWrapper<T>
| ^ expected `:`
|
help: you might have meant to write the type of the const parameter here
|
LL | impl<T, const N: /* Type */> From<[T; N]> for VecWrapper<T>
| ++++++++++++
```
enrich error info when tries to dlopen Enzyme
In rust-lang/rust#127273 I added a test and a FIXME comment pointing out how it does the wrong thing. In the next commit I fixed the problem but forgot to remove the FIXME comment, whoops.
In #127273 I added a test and a FIXME comment pointing out how it does
the wrong thing. In the next commit I fixed the problem but forgot to
remove the FIXME comment, whoops.
Use more principled check for generics in const ops
Fixesrust-lang/rust#144547.
Fixesrust-lang/rust#140891.
In the future, we likely want to make the check less likely to be missed by reducing the number of external entry points to HIR type lowering.
Note: If this causes pass->error regressions (not truly regressions because those cases were mistakenly accepted), they can easily be avoided for the time being by only running the check if `is_self_alias` is true or mgca is enabled.
- **Fix parsing of mgca const blocks in array repeat exprs**
- **Use more principled check for generics in const ops**
There was an inconsistency where in the case of array repeat
expressions, we forgot to eat the `const` keyword of mgca const blocks.
Thus, we ended up parsing them as an anon const containing an inline
const, instead of simply an anon const as they should be.
This commit fixes that issue and also makes the parsing for mgca const
blocks more consistent and simpler in general. For example, we avoid
doing a lookahead check to ensure there's a curly brace coming. There
should always be one after a `const` keyword in an expression context,
and that's handled by the mgca const block parsing function.
Fix ICE by rejecting const blocks in patterns during AST lowering (closes#148138)
This PR fixes the ICE reported in rust-lang/rust#148138.
The root cause is that `const` blocks aren’t allowed in pattern position, but the AST lowering logic still attempted to create `PatExprKind::ConstBlock`, allowing invalid HIR to reach type checking and trigger a `span_bug!`.
Following the discussion in the issue, this patch removes the `ConstBlock` lowering path from `lower_expr_within_pat`. Any `ExprKind::ConstBlock` inside a pattern is now handled consistently with other invalid pattern expressions.
A new UI test is included to ensure the compiler reports a proper error and to prevent regressions.
Closesrust-lang/rust#148138.
Don't use `matches!` when `==` suffices
In the codebase we sometimes use `matches!` for values that can actually just be compared. Replace them with `==`.
Subset of rust-lang/rust#149933.
This fixes the ICE reported by rejecting `const` blocks in
pattern position during AST lowering.
Previously, `ExprKind::ConstBlock` could reach HIR as `PatExprKind::ConstBlock`,
allowing invalid patterns to be type-checked and triggering an ICE.
This patch removes the lowering path for const blocks in patterns
and emits a proper diagnostic instead.
A new UI test is added to ensure the compiler reports a regular error
and to prevent regressions.
Externally implementable items
Supersedes https://github.com/rust-lang/rust/pull/140010
Tracking issue: https://github.com/rust-lang/rust/issues/125418
Getting started:
```rust
#![feature(eii)]
#[eii(eii1)]
pub fn decl1(x: u64)
// body optional (it's the default)
{
println!("default {x}");
}
// in another crate, maybe
#[eii1]
pub fn decl2(x: u64) {
println!("explicit {x}");
}
fn main() {
decl1(4);
}
```
- tiny perf regression, underlying issue makes multiple things in the compiler slow, not just EII, planning to solve those separately.
- No codegen_gcc support, they don't have bindings for weak symbols yet but could
- No windows support yet for weak definitions
This PR merges the implementation of EII for just llvm + not windows, doesn't yet contain like a new panic handler implementation or alloc handler. With this implementation, it would support implementing the panic handler in terms of EII already since it requires no default implementation so no weak symbols
The PR has been open in various forms for about a year now, but I feel that having some implementation merged to build upon
Overhaul filename handling for cross-compiler consistency
This PR overhauls the way we handle filenames in the compiler and `rmeta` in order to achieve achieve cross-compiler consistency (ie. having the same path no matter if the filename was created in the current compiler session or is coming from `rmeta`).
This is required as some parts of the compiler rely on consistent paths for the soundness of generated code (see rust-lang/rust#148328).
In order to achieved consistency multiple steps are being taken by this PR:
- by making `RealFileName` immutable
- by only having `SourceMap::to_real_filename` create `RealFileName`
- currently `RealFileName` can be created from any `Path` and are remapped afterwards, which creates consistency issue
- by also making `RealFileName` holds it's working directory, embeddable name and the remapped scopes
- this removes the need for a `Session`, to know the current(!) scopes and cwd, which is invalid as they may not be equal to the scopes used when creating the filename
In order for `SourceMap::to_real_filename` to know which scopes to apply `FilePathMapping` now takes the current remapping scopes to apply, which makes `FileNameDisplayPreference` and company useless and are removed.
This PR is split-up in multiple commits (unfortunately not atomic), but should help review the changes.
Unblocks https://github.com/rust-lang/rust/pull/147611
Fixes https://github.com/rust-lang/rust/issues/148328
