allow statics pointing to mutable statics
Fixes https://github.com/rust-lang/rust/issues/120450 for good. We can even simplify our checks: no need to specifically go looking for mutable references in const, we can just reject any reference that points to something mutable.
r? `@oli-obk`
Safe Transmute: Revise safety analysis
This PR migrates `BikeshedIntrinsicFrom` to a simplified safety analysis (described [here](https://github.com/rust-lang/project-safe-transmute/issues/15)) that does not rely on analyzing the visibility of types and fields.
The revised analysis treats primitive types as safe, and user-defined types as potentially carrying safety invariants. If Rust gains explicit (un)safe fields, this PR is structured so that it will be fairly easy to thread support for those annotations into the analysis.
Notably, this PR removes the `Context` type parameter from `BikeshedIntrinsicFrom`. Most of the files changed by this PR are just UI tests tweaked to accommodate the removed parameter.
r? `@compiler-errors`
rustc: Fix wasm64 metadata object files
It looks like LLD will detect object files being either 32 or 64-bit depending on any memory present. LLD will additionally reject 32-bit objects during a 64-bit link. Previously metadata objects did not have any memories in them which led LLD to conclude they were 32-bit objects which broke 64-bit targets for wasm.
This commit fixes this by ensuring that for 64-bit targets there's a memory object present to get LLD to detect it's a 64-bit target. Additionally this commit moves away from a hand-crafted wasm encoder to the `wasm-encoder` crate on crates.io as the complexity grows for the generated object file.
Closes#121460
Detect empty leading where clauses on type aliases
1. commit: refactor the AST of type alias where clauses
* I could no longer bear the look of `.0.1` and `.1.0`
* Arguably moving `split` out of `TyAlias` into a substruct might not make that much sense from a semantic standpoint since it reprs an index into `TyAlias.predicates` but it's alright and it cleans up the usage sites of `TyAlias`
2. commit: fix an oversight: An empty leading where clause is still a leading where clause
* semantically reject empty leading where clauses on lazy type aliases
* e.g., on `#![feature(lazy_type_alias)] type X where = ();`
* make empty leading where clauses on assoc types trigger lint `deprecated_where_clause_location`
* e.g., `impl Trait for () { type X where = (); }`
Emitter cleanups
Some cleanups I made when reading emitter code. In particular, `HumanEmitter` and `JsonEmitter` have gone from three constructors to one.
r? `@oli-obk`
Count stashed errors again
Stashed diagnostics are such a pain. Their "might be emitted, might not" semantics messes with lots of things.
#120828 and #121206 made some big changes to how they work, improving some things, but still leaving some problems, as seen by the issues caused by #121206. This PR aims to fix all of them by restricting them in a way that eliminates the "might be emitted, might not" semantics while still allowing 98% of their benefit. Details in the individual commit logs.
r? `@oli-obk`
Skip unnecessary comparison with half-open range patterns
This is the last remaining detail in the implementation of half-open range patterns. Until now, a half-open range pattern like `10..` was converted to `10..T::MAX` before lowering to MIR, which generated an extra pointless comparison. With this PR we don't generate it.
pattern_analysis: rework how we hide empty private fields
Consider this:
```rust
mod foo {
pub struct Bar {
pub a: bool,
b: !,
}
}
fn match_a_bar(bar: foo::Bar) -> bool {
match bar {
Bar { a, .. } => a,
}
}
```
Because the field `b` is private, matches outside the module are not allowed to observe the fact that `Bar` is empty. In particular `match bar {}` is valid within the module `foo` but an error outside (assuming `exhaustive_patterns`).
We currently handle this by hiding the field `b` when it's both private and empty. This means that the pattern `Bar { a, .. }` is lowered to `Bar(a, _)` if we're inside of `foo` and to `Bar(a)` outside. This involves a bit of a dance to keep field indices straight. But most importantly this makes pattern lowering depend on the module.
In this PR, I instead do nothing special when lowering. Only during analysis do we track whether a place must be skipped.
r? `@compiler-errors`
Improve renaming suggestion when item starts with underscore
Fixes https://github.com/rust-lang/rust/issues/121776.
It goes from:
```terminal
error[E0433]: failed to resolve: use of undeclared type `Foo`
--> src/foo.rs:6:13
|
6 | let _ = Foo::Bar;
| ^^^ use of undeclared type `Foo`
|
help: an enum with a similar name exists, consider changing it
|
1 | enum Foo {
| ~~~
```
to:
```terminal
error[E0433]: failed to resolve: use of undeclared type `Foo`
--> foo.rs:6:13
|
6 | let _ = Foo::Bar;
| ^^^ use of undeclared type `Foo`
|
help: an enum with a similar name exists, consider renaming `_Foo` into `Foo`
|
1 | enum Foo {
| ~~~
error: aborting due to 1 previous error
```
Fix `async Fn` confirmation for `FnDef`/`FnPtr`/`Closure` types
Fixes three issues:
1. The code in `extract_tupled_inputs_and_output_from_async_callable` was accidentally getting the *future* type and the *output* type (returned by the future) messed up for fnptr/fndef/closure types. :/
2. We have a (class of) bug(s) in the old solver where we don't really support higher ranked built-in `Future` goals for generators. This is not possible to hit on stable code, but [can be hit with `unboxed_closures`](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=e935de7181e37e13515ad01720bcb899) (#121653).
* I'm opting not to fix that in this PR. Instead, I just instantiate placeholders when confirming `async Fn` goals.
4. Fixed a bug when generating `FnPtr` shims for `async Fn` trait goals.
r? oli-obk
Fix typo in `rustc_passes/messages.ftl`
Line 190 contains unpaired parentheses:
```
passes_doc_cfg_hide_takes_list =
`#[doc(cfg_hide(...)]` takes a list of attributes
```
The `#[doc(cfg_hide(...)]` contains unpaired parentheses. This PR changes it to `#[doc(cfg_hide(...))]`, which made the parentheses paired.
Deeply normalize obligations in `refining_impl_trait`
We somewhat awkwardly use semantic comparison when checking the `refining_impl_trait` lint. This relies on us being able to normalize bounds eagerly to avoid cases where an unnormalized alias is not considered equal to a normalized alias. Since `normalize` in the new solver is a noop, let's use `deeply_normalize` instead.
r? lcnr
cc ``@tmandry,`` this should fix your bug lol
And likewise with `ColorConfig::suggests_using_colors`. They both have a
single call site. And note that `BufWriter::supports_color()` always
returns false, which enables a small bit of constant folding along the
way.
In practice, 'a and 'b and 'c are always the same. This change makes
`UnusedExterns` more like `ArtifactNotification`, which uses a single
lifetime 'a in multiple ways.
I removed it in #121206 because I thought thought it wasn't necessary.
But then I had to add an `emit_stashed_diagnostics` call elsewhere in
rustfmt to avoid the assertion failure (which took two attempts to get
right, #121487 and #121615), and now there's an assertion failure in
clippy as well (https://github.com/rust-lang/rust-clippy/issues/12364).
So this commit just reinstates the call in `DiagCtxtInner::drop`. It
also reverts the rustfmt changes from #121487 and #121615, though it
keeps the tests added for those PRs.
Stashed errors used to be counted as errors, but could then be
cancelled, leading to `ErrorGuaranteed` soundness holes. #120828 changed
that, closing the soundness hole. But it introduced other difficulties
because you sometimes have to account for pending stashed errors when
making decisions about whether errors have occured/will occur and it's
easy to overlook these.
This commit aims for a middle ground.
- Stashed errors (not warnings) are counted immediately as emitted
errors, avoiding the possibility of forgetting to consider them.
- The ability to cancel (or downgrade) stashed errors is eliminated, by
disallowing the use of `steal_diagnostic` with errors, and introducing
the more restrictive methods `try_steal_{modify,replace}_and_emit_err`
that can be used instead.
Other things:
- `DiagnosticBuilder::stash` and `DiagCtxt::stash_diagnostic` now both
return `Option<ErrorGuaranteed>`, which enables the removal of two
`delayed_bug` calls and one `Ty::new_error_with_message` call. This is
possible because we store error guarantees in
`DiagCtxt::stashed_diagnostics`.
- Storing the guarantees also saves us having to maintain a counter.
- Calls to the `stashed_err_count` method are no longer necessary
alongside calls to `has_errors`, which is a nice simplification, and
eliminates two more `span_delayed_bug` calls and one FIXME comment.
- Tests are added for three of the four fixed PRs mentioned below.
- `issue-121108.rs`'s output improved slightly, omitting a non-useful
error message.
Fixes#121451.
Fixes#121477.
Fixes#121504.
Fixes#121508.
This commit:
- Moves the ICE file create/open outside the loop. (Redoing it on every
loop iteration works, but is really weird.)
- Moves the explanatory note emission above the loop, which removes the
need for the `enumerate` call.
- Introduces a `decorate` local.
This gives one extra error message on two tests, but is necessary to fix
bigger problems caused by the cancellation of stashed errors.
(Note: why not just avoid stashing altogether? Because that resulted in
additional output changes.)
This gives one extra error message on one test, but is necessary to fix
bigger problems caused by the cancellation of stashed errors.
(Note: why not just avoid stashing altogether? Because that resulted in
additional output changes.)
Opportunistically resolve regions when processing region outlives obligations
Due to the matching in `TypeOutlives` being structural, we should attempt to opportunistically resolve regions before processing region obligations. Thanks ``@lcnr`` for finding this.
r? lcnr
Use `LitKind::Err` for malformed floats
#121120 changed `StringReader::cook_lexer_literal` to return `LitKind::Err` for malformed integer literals. This commit does the same for float literals, for consistency.
r? ``@fmease``
Diagnostic renaming
Renaming various diagnostic types from `Diagnostic*` to `Diag*`. Part of https://github.com/rust-lang/compiler-team/issues/722. There are more to do but this is enough for one PR.
r? `@davidtwco`
