Match Ergonomics 2024: update old-edition behavior of feature gates
This updates the behavior of the feature gates `ref_pat_eat_one_layer_2024_structural` and `ref_pat_eat_one_layer_2024` in Editions 2021 and earlier to correspond to the left and right typing rules compared [here](https://nadrieril.github.io/typing-rust-patterns/?opts1=AQEBAQIBAQEBAAAAAAAAAAAAAAAAAAA%3D&style=UserVisible&compare=true&opts2=AQEBAQIBAQABAAAAAQEBAAEBAAABAAA%3D&mode=rules), respectively. Compared to the `stable_rust` rules:
- they both allow reference patterns to match a lone inherited ref,
- they both allow `&` patterns to eat `&mut` reference types (and lone `&mut` inherited refs) as if they're shared,
- they both allow `&mut` patterns to eat `&` reference types when there's a `&mut` inherited reference to also eat,
- and the left ruleset has RFC 3627's Rule 3: after encountering a shared reference type in the scrutinee, the default binding mode will be treated as by-shared-ref when it would otherwise be by-mutable-ref.
I think there's already tests for all of those typing rules, so I've added revisions to use the existing tests with the new rulesets. Additionally, I've added a few tests to make sure we handle mixed-edition patterns appropriately, and I've added references to the unstable book.
Relevant tracking issue: #123076
r? ``@ghost``
- For shifts this shrinks the IR by no longer needing an `assume` while still providing the UB information
- Having this on the `i8`→`i1` truncations will hopefully help with some places that have to load `i8`s or pass those in LLVM structs without range information
```
warning: cannot find macro `in_root` in the crate root
--> $DIR/key-value-expansion-scope.rs:1:10
|
LL | #![doc = in_root!()]
| ^^^^^^^ not found in the crate root
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #124535 <https://github.com/rust-lang/rust/issues/124535>
= help: import `macro_rules` with `use` to make it callable above its definition
= note: `#[warn(out_of_scope_macro_calls)]` on by default
```
This commit removes the `avr-unknown-gnu-atmega328` target and replaces
it with a more generic `avr-none` variant that must be specialized with
the `-C target-cpu` flag (e.g. `-C target-cpu=atmega328p`).
coverage: Get hole spans from nested items without fully visiting them
This is a small simplification to the code that collects the spans of nested items within a function, so that those spans can be treated as “holes” to be avoided by the current function's coverage mappings.
The old code was using `nested_filter::All` to ensure that the visitor would see nested items. But we don't need the actual items themselves; we just need their spans, which we can obtain via a custom implementation of `visit_nested_item`.
This avoids the more expansive queries required by `nested_filter::All`.
Don't mention `FromResidual` on bad `?`
Unless `try_trait_v2` is enabled, don't mention that `FromResidual` isn't implemented for a specific type when the implicit `From` conversion of a `?` fails. For the end user on stable, `?` might as well be a compiler intrinsic, so we remove that note to avoid further confusion and allowing other parts of the error to be more prominent.
```
error[E0277]: `?` couldn't convert the error to `u8`
--> $DIR/bad-interconversion.rs:4:20
|
LL | fn result_to_result() -> Result<u64, u8> {
| --------------- expected `u8` because of this
LL | Ok(Err(123_i32)?)
| ------------^ the trait `From<i32>` is not implemented for `u8`
| |
| this can't be annotated with `?` because it has type `Result<_, i32>`
|
= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
= help: the following other types implement trait `From<T>`:
`u8` implements `From<Char>`
`u8` implements `From<bool>`
```
When encountering a doc comment without an identifier after, we'd unconditionally state "this doc comment doesn't document anything", swallowing the *actual* error which is that the thing *after* the doc comment wasn't expected. Added a check that the found token is something that "conceptually" closes the previous item before emitting that error, otherwise just complain about the missing identifier.
In both of the following cases, the syntax error follows a doc comment:
```
error: expected identifier, found keyword `Self`
--> $DIR/doc-before-bad-variant.rs:4:5
|
LL | enum TestEnum {
| -------- while parsing this enum
...
LL | Self,
| ^^^^ expected identifier, found keyword
|
= help: enum variants can be `Variant`, `Variant = <integer>`, `Variant(Type, ..., TypeN)` or `Variant { fields: Types }`
```
```
error: expected identifier, found `<`
--> $DIR/doc-before-syntax-error.rs:2:1
|
LL | <>
| ^ expected identifier
```
Fix#71982.
rustfmt doesn't touch it because it's a macro body, but it's large
enough that the misformatting is annoying. This commit improves it. The
most common problems fixed:
- Unnecessary multi-line patterns reduced to one line.
- Multi-line function headers adjusted so the parameter indentation
doesn't depend on the length of the function name. (This is Rust code,
not C.)
- `|` used at the start of lines, not the end.
- More consistent formatting of empty function bodies.
- Overly long lines are broken.
The `MirVisitable` trait is just a complicated way to visit either a
statement or a terminator. (And its impl for `Terminator` is unused.) It
has a single use.
This commit removes it, replacing it with an if/else, which is shorter
and simpler.
`visit_local` is the only method that doesn't call a corresponding
`super_local` method. This is valid, because `super_local` would be
empty. But it's inconsistent with every other case; we have multiple
other empty `super` methods: `super_span`, `super_ty`, etc.
This commit adds an empty `super_local` and makes `visit_local` call it.
Emit dropck normalization errors in borrowck
Borrowck generally assumes that any queries it runs for type checking will succeed, thinking that HIR typeck will have errored first if there was a problem. However as of #98641, dropck isn't run on HIR, so there's no direct guarantee that it doesn't error. While a type being well-formed might be expected to ensure that its fields are well-formed, this is not the case for types containing a type projection:
```rust
pub trait AuthUser {
type Id;
}
pub trait AuthnBackend {
type User: AuthUser;
}
pub struct AuthSession<Backend: AuthnBackend> {
data: Option<<<Backend as AuthnBackend>::User as AuthUser>::Id>,
}
pub trait Authz: Sized {
type AuthnBackend: AuthnBackend<User = Self>;
}
pub fn run_query<User: Authz>(auth: AuthSession<User::AuthnBackend>) {}
// ^ No User: AuthUser bound is required or inferred.
```
While improvements to trait solving might fix this in the future, for now we go for a pragmatic solution of emitting an error from borrowck (by rerunning dropck outside of a query) and making drop elaboration check if an error has been emitted previously before panicking for a failed normalization.
Closes#103899Closes#135039
r? `@compiler-errors` (feel free to re-assign)
Rollup of 9 pull requests
Successful merges:
- #136936 (Use 'yes' instead of 'while-echo' in tests/ui/process/process-sigpipe.rs except 'nto')
- #137026 (Stabilize (and const-stabilize) `integer_sign_cast`)
- #137059 (fix: Alloc new errorcode E0803 for E0495)
- #137177 (Update `minifier-rs` version to `0.3.5`)
- #137210 (compiler: Stop reexporting stuff in cg_llvm::abi)
- #137213 (Remove `rustc_middle::mir::tcx` module.)
- #137216 (eval_outlives: bail out early if both regions are in the same SCC)
- #137228 (Fix typo in hidden internal docs of `TrustedRandomAccess`)
- #137242 (Add reference annotations for the `do_not_recommend` attribute)
r? `@ghost`
`@rustbot` modify labels: rollup
It turns out that this visitor doesn't actually need `nested_filter::All` to
handle nested items; it just needs to override `visit_nested_item` and look up
the item's span.
My reasoning: the ruleset implemented by the same feature gate in
Edition 2024 always tries to eat the inherited reference first. For
consistency, it makes sense to me to say across all editions that users
should consider the inherited reference's mutability when wondering if a
`&mut` pattern will type.
x86: use SSE2 to pass float and SIMD types
This builds on the new X86Sse2 ABI landed in https://github.com/rust-lang/rust/pull/137037 to actually make it a separate ABI from the default x86 ABI, and use SSE2 registers. Specifically, we use it in two ways: to return `f64` values in a register rather than by-ptr, and to pass vectors of size up to 128bit in a register (or, well, whatever LLVM does when passing `<4 x float>` by-val, I don't actually know if this ends up in a register).
Cc `@workingjubilee`
Fixes#133611
try-job: aarch64-apple
try-job: aarch64-gnu
try-job: aarch64-gnu-debug
try-job: test-various
try-job: x86_64-gnu-nopt
try-job: dist-i586-gnu-i586-i686-musl
try-job: x86_64-msvc-1
eval_outlives: bail out early if both regions are in the same SCC
A drive-by optimisation of region outlives evaluation: if we are evaluating whether an outlives holds for two regions, bail out early if they are both in the same SCC.
This probably won't make a huge difference, but the cost is one comparison of SCC indices (integers).
May want a perf run, depending on how confident whomever reviewing this is!
Remove `rustc_middle::mir::tcx` module.
This is a really weird module. For example, what does `tcx` in `rustc_middle::mir::tcx::PlaceTy` mean? The answer is "not much".
The top-level module comment says:
> Methods for the various MIR types. These are intended for use after
> building is complete.
Awfully broad for a module that has a handful of impl blocks for some MIR types, none of which really relates to `TyCtxt`. `git blame` indicates the comment is ancient, from 2015, and made sense then.
This module is now vestigial. This commit removes it and moves all the code within into `rustc_middle::mir::statement`. Some specifics:
- `Place`, `PlaceRef`, `Rvalue`, `Operand`, `BorrowKind`: they all have `impl` blocks in both the `tcx` and `statement` modules. The commit merges the former into the latter.
- `BinOp`, `UnOp`: they only have `impl` blocks in `tcx`. The commit moves these into `statement`.
- `PlaceTy`, `RvalueInitializationState`: they are defined in `tcx`. This commit moves them into `statement` *and* makes them available in `mir::*`, like many other MIR types.
r? `@tmandry`
compiler: Stop reexporting stuff in cg_llvm::abi
The reexports confuse tooling like rustdoc into thinking cg_llvm is the source of key types that originate in rustc_target.
This is a really weird module. For example, what does `tcx` in
`rustc_middle::mir::tcx::PlaceTy` mean? The answer is "not much".
The top-level module comment says:
> Methods for the various MIR types. These are intended for use after
> building is complete.
Awfully broad for a module that has a handful of impl blocks for some
MIR types, none of which really relates to `TyCtxt`. `git blame`
indicates the comment is ancient, from 2015, and made sense then.
This module is now vestigial. This commit removes it and moves all the
code within into `rustc_middle::mir::statement`. Some specifics:
- `Place`, `PlaceRef`, `Rvalue`, `Operand`, `BorrowKind`: they all have `impl`
blocks in both the `tcx` and `statement` modules. The commit merges
the former into the latter.
- `BinOp`, `UnOp`: they only have `impl` blocks in `tcx`. The commit
moves these into `statement`.
- `PlaceTy`, `RvalueInitializationState`: they are defined in `tcx`.
This commit moves them into `statement` *and* makes them available in
`mir::*`, like many other MIR types.
Suggest replacing `.` with `::` when encountering "expected value, found enum":
- in a method-call expression and the method has the same name as a tuple variant
- in a field-access expression and the field has the same name as a unit or tuple variant
When `Foo.field` or `Foo.method()` exprs are encountered, suggest `Foo::field` or `Foo::method()` when Foo is a type alias, not just
a struct, trait, or module.
Also rename test for this suggestion from issue-22692.rs to something more meaningful.
Pattern Migration 2024: fix incorrect messages/suggestions when errors arise in macro expansions
See the diff between the two commits for how this affected the error message and suggestion. In order to decide how to format those, the pattern migration diagnostic keeps track of which parts of the user's pattern cause problems in Edition 2024. However, it neglected to do some of this bookkeeping when pointing to macro expansion sites. This fixes that.
