Fix another assertion failure for some Expect diagnostics.
Very similar to #126719. So much so that I added a new case to the test from that PR rather than creating a new one.
r? `@oli-obk`
Make edition dependent `:expr` macro fragment act like the edition-dependent `:pat` fragment does
Parse the `:expr` fragment as `:expr_2021` in editions <=2021, and as `:expr` in edition 2024. This is similar to how we parse `:pat` as `:pat_param` in edition <=2018 and `:pat_with_or` in >=2021, and means we can get rid of a span dependency from `nonterminal_may_begin_with`.
Specifically, this fixes a theoretical regression since the `expr_2021` macro fragment previously would allow `const {}` if the *caller* is edition 2024. This is inconsistent with the way that the `pat` macro fragment was upgraded, and also leads to surprising behavior when a macro *caller* crate upgrades to edtion 2024, since they may have parsing changes that they never asked for (with no way of opting out of it).
This PR also allows using `expr_2021` in all editions. Why was this was disallowed in the first place? It's purely additive, and also it's still feature gated?
r? ```@fmease``` ```@eholk``` cc ```@vincenzopalazzo```
cc #123865
Tracking:
- https://github.com/rust-lang/rust/issues/123742
Expand `avx512_target_feature` to include VEX variants
Added 5 new target features for x86:
- `AVX-IFMA`
- `AVX-NE-CONVERT`
- `AVX-VNNI`
- `AVX-VNNI_INT8`
- `AVX-VNNI_INT16`
Both LLVM and GCC already have support for these.
See also the [stdarch PR](https://github.com/rust-lang/stdarch/pull/1586)
Improve conflict marker recovery
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closes#113826
r? ```@estebank``` since you reviewed #115413
cc: ```@rben01``` since you opened up the issue in the first place
Properly gate `safe` keyword in pre-expansion
This PR gates `safe` keyword in pre-expansion contexts. Should mitigate the fallout of https://github.com/rust-lang/rust/issues/126755, which is that `safe` is now usable on beta lol.
r? `@spastorino` or `@oli-obk`
cc #124482 tracking #123743
add `needs-unwind` to UI test
the `tail-expr-lock-poisoning` UI test uses the `panic::catch_unwind` API so it relies on unwinding being implemented. this test ought not to run on targets that do not support unwinding. add the `needs-unwind` attribute to signal this
collect attrs in const block expr
Fixes#126516Fixes#126647
It was forgotten to collect these attributes in the const block expression.
r? `@petrochenkov`
the `tail-expr-lock-poisoning` UI test uses the `panic::catch_unwind`
API so it relies on unwinding being implemented. this test ought not to
run on targets that do not support unwinding. add the `needs-unwind`
attribute to signal this
Add opaque type corner case test
r? ``@lcnr``
I can't make sense of the new solver tracing logs yet, so I just added the test without explanation.
The old solver does not yet figure out that `Foo == ()` from the where bounds. Unfortunately, even if we make it understand that, it will later try to prove `<X as Trait<'static>>::Out<Foo>: Sized` via the `is_sized_raw` query, which does not take a list of defineable opaque types, causing that check to fail with an ICE.
Thus I'm submitting this test case on its own just to ensure we handle it correctly in the future with any new solver or old solver changes.
Fix assertion failure for some `Expect` diagnostics.
In #120699 I moved some code dealing with `has_future_breakage` earlier in `emit_diagnostic`. Issue #126521 identified a case where that reordering was invalid (leading to an assertion failure) for some `Expect` diagnostics.
This commit partially undoes the change, by moving the handling of unstable `Expect` diagnostics earlier again. This makes `emit_diagnostic` a bit uglier, but is necessary to fix the problem.
Fixes#126521.
r? ``@oli-obk``
More status-quo tests for the `#[coverage(..)]` attribute
Follow-up to #126621, after I found even more weird corner-cases in the handling of the coverage attribute.
These tests reveal some inconsistencies that are tracked by #126658.
Stabilise `c_unwind`
Fix#74990Fix#115285 (that's also where FCP is happening)
Marking as draft PR for now due to `compiler_builtins` issues
r? `@Amanieu`
Clarify that anonymous consts still do introduce a new scope
See https://github.com/rust-lang/rust/issues/120363#issuecomment-2177064702
This error message is misleading: it's trying to say that `const _ : () = ...` is a workaround for the lint, but by saying that anonymous constants are treated as being in the parent scope, it makes them appear useless for scope-hiding.
They *are* useful for scope-hiding, they are simply treated as part of the parent scope when it comes to this lint.
Actually taint InferCtxt when a fulfillment error is emitted
And avoid checking the global error counter
fixes#122044fixes#123255fixes#123276fixes#125799
In #120699 I moved some code dealing with `has_future_breakage` earlier
in `emit_diagnostic`. Issue #126521 identified a case where that
reordering was invalid (leading to an assertion failure) for some `Expect`
diagnostics.
This commit partially undoes the change, by moving the handling of
unstable `Expect` diagnostics earlier again. This makes
`emit_diagnostic` a bit uglier, but is necessary to fix the problem.
Fixes#126521.
Fix duplicated attributes on nonterminal expressions
This PR fixes a long-standing bug (#86055) whereby expression attributes can be duplicated when expanded through declarative macros.
First, consider how items are parsed in declarative macros:
```
Items:
- parse_nonterminal
- parse_item(ForceCollect::Yes)
- parse_item_
- attrs = parse_outer_attributes
- parse_item_common(attrs)
- maybe_whole!
- collect_tokens_trailing_token
```
The important thing is that the parsing of outer attributes is outside token collection, so the item's tokens don't include the attributes. This is how it's supposed to be.
Now consider how expression are parsed in declarative macros:
```
Exprs:
- parse_nonterminal
- parse_expr_force_collect
- collect_tokens_no_attrs
- collect_tokens_trailing_token
- parse_expr
- parse_expr_res(None)
- parse_expr_assoc_with
- parse_expr_prefix
- parse_or_use_outer_attributes
- parse_expr_dot_or_call
```
The important thing is that the parsing of outer attributes is inside token collection, so the the expr's tokens do include the attributes, i.e. in `AttributesData::tokens`.
This PR fixes the bug by rearranging expression parsing to that outer attribute parsing happens outside of token collection. This requires a number of small refactorings because expression parsing is somewhat complicated. While doing so the PR makes the code a bit cleaner and simpler, by eliminating `parse_or_use_outer_attributes` and `Option<AttrWrapper>` arguments (in favour of the simpler `parse_outer_attributes` and `AttrWrapper` arguments), and simplifying `LhsExpr`.
r? `@petrochenkov`
Rollup of 6 pull requests
Successful merges:
- #125447 (Allow constraining opaque types during subtyping in the trait system)
- #125766 (MCDC Coverage: instrument last boolean RHS operands from condition coverage)
- #125880 (Remove `src/tools/rust-demangler`)
- #126154 (StorageLive: refresh storage (instead of UB) when local is already live)
- #126572 (override user defined channel when using precompiled rustc)
- #126662 (Unconditionally warn on usage of `wasm32-wasi`)
r? `@ghost`
`@rustbot` modify labels: rollup
Allow constraining opaque types during subtyping in the trait system
Previous attempt: https://github.com/rust-lang/rust/pull/123979
Sometimes we don't immediately perform subtyping, but instead register a subtyping obligation and solve that obligation when its inference variables become resolved. Unlike immediate subtyping, we currently do not allow registering hidden types for opaque types. This PR also allows that.
It now parses outer attributes before collecting tokens. This avoids the
problem where the outer attribute tokens were being stored twice -- for
the attribute tokesn, and also for the expression tokens.
Fixes#86055.
Rollup of 7 pull requests
Successful merges:
- #123782 (Test that opaque types can't have themselves as a hidden type with incompatible lifetimes)
- #124580 (Suggest removing unused tuple fields if they are the last fields)
- #125787 (Migrate `bin-emit-no-symbols` `run-make` test to `rmake`)
- #126553 (match lowering: expand or-candidates mixed with candidates above)
- #126594 (Make async drop code more consistent with regular drop code)
- #126654 (Make pretty printing for `f16` and `f128` consistent)
- #126656 (rustc_type_ir: Omit some struct fields from Debug output)
r? `@ghost`
`@rustbot` modify labels: rollup
match lowering: expand or-candidates mixed with candidates above
This PR tweaks match lowering of or-patterns. Consider this:
```rust
match (x, y) {
(1, true) => 1,
(2, false) => 2,
(1 | 2, true | false) => 3,
(3 | 4, true | false) => 4,
_ => 5,
}
```
One might hope that this can be compiled to a single `SwitchInt` on `x` followed by some boolean checks. Before this PR, we compile this to 3 `SwitchInt`s on `x`, because an arm that contains more than one or-pattern was compiled on its own. This PR groups branch `3` with the two branches above, getting us down to 2 `SwitchInt`s on `x`.
We can't in general expand or-patterns freely, because this interacts poorly with another optimization we do: or-pattern simplification. When an or-pattern doesn't involve bindings, we branch the success paths of all its alternatives to the same block. The drawback is that in a case like:
```rust
match (1, true) {
(1 | 2, false) => unreachable!(),
(2, _) => unreachable!(),
_ => {}
}
```
if we used a single `SwitchInt`, by the time we test `false` we don't know whether we came from the `1` case or the `2` case, so we don't know where to go if `false` doesn't match.
Hence the limitation: we can process or-pattern alternatives alongside candidates that precede it, but not candidates that follow it. (Unless the or-pattern is the only remaining match pair of its candidate, in which case we can process it alongside whatever).
This PR allows the processing of or-pattern alternatives alongside candidates that precede it. One benefit is that we now process or-patterns in a single place in `mod.rs`.
r? ``@matthewjasper``
Suggest removing unused tuple fields if they are the last fields
Fixes#124556
We now check if dead/unused fields are the last fields of the tuple and suggest their removal instead of suggesting them to be changed to `()`.
Test that opaque types can't have themselves as a hidden type with incompatible lifetimes
fixes#122876
This PR used to add extra logic to prevent those cases, but after https://github.com/rust-lang/rust/pull/113169 this is implicitly rejected, because such usages are not defining.
improve tip for inaccessible traits
Improve the tips when the candidate method is from an inaccessible trait.
For example:
```rs
mod m {
trait Trait {
fn f() {}
}
impl<T> Trait for T {}
}
fn main() {
struct S;
S::f();
}
```
The difference between before and now is:
```diff
error[E0599]: no function or associated item named `f` found for struct `S` in the current scope
--> ./src/main.rs:88:6
|
LL | struct S;
| -------- function or associated item `f` not found for this struct
LL | S::f();
| ^ function or associated item not found in `S`
|
= help: items from traits can only be used if the trait is implemented and in scope
- help: trait `Trait` which provides `f` is implemented but not in scope; perhaps you want to import it
+ help: trait `crate:Ⓜ️:Trait` which provides `f` is implemented but not reachable
|
- LL + use crate:Ⓜ️:Trait;
|
```
hir_typeck: be more conservative in making "note caller chooses ty param" note
In https://github.com/rust-lang/rust/pull/122195 I added a "caller chooses ty for type param" note for when the return expression type a.k.a. found type does not match the expected return type.
#126547 found that this note was confusing when the found return type *contains* the expected type, e.g.
```rs
fn f<T>(t: &T) -> T {
t
}
```
because the found return type `&T` will *always* be different from the expected return type `T`, so the note was needlessly redundant and confusing.
This PR addresses that by not making the note if the found return type contains the expected return type.
r? ``@fmease`` (since you reviewed the original PR)
Fixes https://github.com/rust-lang/rust/issues/126547
safe transmute: support non-ZST, variantful, uninhabited enums
Previously, `Tree::from_enum`'s implementation branched into three disjoint cases:
1. enums that uninhabited
2. enums for which all but one variant is uninhabited
3. enums with multiple variants
This branching (incorrectly) did not differentiate between variantful and variantless uninhabited enums. In both cases, we assumed (and asserted) that uninhabited enums are zero-sized types. This assumption is false for enums like:
enum Uninhabited { A(!, u128) }
...which, currently, has the same size as `u128`. This faulty assumption manifested as the ICE reported in #126460.
In this PR, we revise the first case of `Tree::from_enum` to consider only the narrow category of "enums that are uninhabited ZSTs". These enums, whose layouts are described with `Variants::Single { index }`, are special in their layouts otherwise resemble the `!` type and cannot be descended into like typical enums. This first case captures uninhabited enums like:
enum Uninhabited { A(!, !), B(!) }
The second case is revised to consider the broader category of "enums that defer their layout to one of their variants"; i.e., enums whose layouts are described with `Variants::Single { index }` and that do have a variant at `index`. This second case captures uninhabited enums that are not ZSTs, like:
enum Uninhabited { A(!, u128) }
...which represent their variants with `Variants::Single`.
Finally, the third case is revised to cover the broader category of "enums with multiple variants", which captures uninhabited enums like:
enum Uninhabited { A(u8, !), B(!, u32) }
...which represent their variants with `Variants::Multiple`.
This PR also adds a comment requested by ````@RalfJung```` in his review of #126358 to `compiler/rustc_const_eval/src/interpret/discriminant.rs`.
Fixes#126460
r? ````@compiler-errors````
Place tail expression behind terminating scope
This PR implements #123739 so that we can do further experiments in nightly.
A little rewrite has been applied to `for await` lowering. It was previously `unsafe { Pin::unchecked_new(into_async_iter(..)) }`. Under the edition 2024 rule, however, `into_async_iter` gets dropped at the end of the `unsafe` block. This presumably the first Edition 2024 migration rule goes by hoisting `into_async_iter(..)` into `match` one level above, so it now looks like the following.
```rust
match into_async_iter($iter_expr) {
ref mut iter => match unsafe { Pin::unchecked_new(iter) } {
...
}
}
```
delegation: Implement glob delegation
Support delegating to all trait methods in one go.
Overriding globs with explicit definitions is also supported.
The implementation is generally based on the design from https://github.com/rust-lang/rfcs/pull/3530#issuecomment-2020869823, but unlike with list delegation in https://github.com/rust-lang/rust/pull/123413 we cannot expand glob delegation eagerly.
We have to enqueue it into the queue of unexpanded macros (most other macros are processed this way too), and then a glob delegation waits in that queue until its trait path is resolved, and enough code expands to generate the identifier list produced from the glob.
Glob delegation is only allowed in impls, and can only point to traits.
Supporting it in other places gives very little practical benefit, but significantly raises the implementation complexity.
Part of https://github.com/rust-lang/rust/issues/118212.
