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
In the previous code, the success block of `lhs` would jump directly to the
success block of `rhs`. However, `rhs_success_block` could already contain
statements that are specific to the RHS, and the direct goto causes them to be
executed in the LHS success path as well.
This patch therefore creates a fresh block that the LHS and RHS success blocks
can both jump to.
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`
Process alias-relate obligations in CoerceUnsized loop
After #119106, we now emit `AliasRelate` goals when relating `?0` and `Alias<T, ..>` in the new solver. In the ad-hoc `CoerceUnsized` selection loop, we now may have `AliasRelate` goals which must be processed to constrain type variables which are mentioned in other goals.
---
For example, in the included test, we try to coerce `&<ManuallyDrop<T> as Deref>::Target` to `&dyn Foo`. This requires proving:
* 1 `&<ManuallyDrop<T> as Deref>::Target: CoerceUnsized<&dyn Foo>`
* 2 `<ManuallyDrop<T> as Deref>::Target alias-relate ?0`
* 3 `?0: Unsize<dyn Foo>`
* 4 `?0: Foo`
* 5 `?0: Sized`
If we don't process goal (2.) before processing goal (3.), then we hit ambiguity since `?0` is never constrained, and therefore we bail out, refusing to coerce the types. After processing (2.), we know `?0 := T`, and the rest of the goals can be processed normally.
Split rustc_type_ir to avoid rustc_ast from depending on it
unblocks #121576
and resolves a FIXME in `rustc_ast`'s `Cargo.toml`
The new crate is tiny, but it will get bigger in #121576
Adjust printing for RPITITs
1. Call RPITITs `{synthetic#N}` instead of `{opaque#N}`.
2. Fall back to printing the RPITIT like an opaque even when printed as an `AliasTy`, just like we do for `ty::Alias`.
You could argue that (2.) is misleading, but I believe it's more consistent than naming `{synthetic#N}`, which I assume approximately nobody knows where that def path name comes from.
r? lcnr
Changing some attributes to only_local.
Modified according to https://github.com/rust-lang/compiler-team/issues/505.
By running test cases, I found that modifying the attribute's only_local tag sometimes causes some unintuitive error reports, so I tend to split it into multiple PRs and edit a small number of attributes each time to prevent too many changes at once. Prevent possible subsequent difficulties in locating problems.
r? ``@lcnr``
Remove the `UntranslatableDiagnosticTrivial` lint.
It's a specialized form of the `UntranslatableDiagnostic` lint that is deny-by-default.
Now that `UntranslatableDiagnostic` has been changed from allow-by-default to deny-by-default, the trivial variant is no longer needed.
r? ``@davidtwco``
It's a specialized form of the `UntranslatableDiagnostic` lint that is
deny-by-default.
Now that `UntranslatableDiagnostic` has been changed from
allow-by-default to deny-by-default, the trivial variant is no longer
needed.
Note the change of the `D` to `d`, to match all the other names that
have `Subdiag` in them, such as `SubdiagnosticMessage` and
`derive(Subdiagnostic)`.
Add a new `wasm32-wasi-preview2` target
This is the initial implementation of the MCP https://github.com/rust-lang/compiler-team/issues/694 creating a new tier 3 target `wasm32-wasi-preview2`. That MCP has been seconded and will most likely be approved in a little over a week from now. For more information on the need for this target, please read the [MCP](https://github.com/rust-lang/compiler-team/issues/694).
There is one aspect of this PR that will become insta-stable once these changes reach a stable compiler:
* A new `target_family` named `wasi` is introduced. This target family incorporates all wasi targets including `wasm32-wasi` and its derivative `wasm32-wasi-preview1-threads`. The difference between `target_family = wasi` and `target_os = wasi` will become much clearer when `wasm32-wasi` is renamed to `wasm32-wasi-preview1` and the `target_os` becomes `wasm32-wasi-preview1`. You can read about this target rename in [this MCP](https://github.com/rust-lang/compiler-team/issues/695) which has also been seconded and will hopefully be officially approved soon.
Additional technical details include:
* Both `std::sys::wasi_preview2` and `std::os::wasi_preview2` have been created and mostly use `#[path]` annotations on their submodules to reach into the existing `wasi` (soon to be `wasi_preview1`) modules. Over time the differences between `wasi_preview1` and `wasi_preview2` will grow and most like all `#[path]` based module aliases will fall away.
* Building `wasi-preview2` relies on a [`wasi-sdk`](https://github.com/WebAssembly/wasi-sdk) in the same way that `wasi-preview1` does (one must include a `wasi-root` path in the `Config.toml` pointing to sysroot included in the wasi-sdk). The target should build against [wasi-sdk v21](https://github.com/WebAssembly/wasi-sdk/releases/tag/wasi-sdk-21) without modifications. However, the wasi-sdk itself is growing [preview2 support](https://github.com/WebAssembly/wasi-sdk/pull/370) so this might shift rapidly. We will be following along quickly to make sure that building the target remains possible as the wasi-sdk changes.
* This requires a [patch to libc](https://github.com/rylev/rust-libc/tree/wasm32-wasi-preview2) that we'll need to land in conjunction with this change. Until that patch lands the target won't actually build.
ffi_unwind_calls: treat RustIntrinsic like regular Rust calls
Also add some comments to `abi_can_unwind` to explain what happens.
r? `@nbdd0121` Cc `@BatmanAoD`
Delayed bug audit
I went through all the calls to `delayed_bug` and `span_delayed_bug` and found a few places where they could be avoided.
r? `@compiler-errors`
Remove useless lifetime of ArchiveBuilder
`trait ArchiveBuilder<'a>` has a seemingly useless lifetime a, so I remove it. If this is intentional, please reject this PR.
```rust
pub trait ArchiveBuilder<'a> {
fn add_file(&mut self, path: &Path);
fn add_archive(
&mut self,
archive: &Path,
skip: Box<dyn FnMut(&str) -> bool + 'static>,
) -> io::Result<()>;
fn build(self: Box<Self>, output: &Path) -> bool;
}
```
Modified according to https://github.com/rust-lang/compiler-team/issues/505.
By running test cases, I found that modifying the attribute's only_local tag sometimes causes some unintuitive error reports, so I tend to split it into multiple PRs and edit a small number of attributes each time to prevent too many changes at once. Prevent possible subsequent difficulties in locating problems.
rename 'try' intrinsic to 'catch_unwind'
The intrinsic has nothing to do with `try` blocks, and corresponds to the stable `catch_unwind` function, so this makes a lot more sense IMO.
Also rename Miri's special function while we are at it, to reflect the level of abstraction it works on: it's an unwinding mechanism, on which Rust implements panics.
Rollup of 6 pull requests
Successful merges:
- #121389 (llvm-wrapper: fix few warnings)
- #121493 (By changing some attributes to only_local, reducing encoding attributes in the crate metadate.)
- #121615 (Move `emit_stashed_diagnostic` call in rustfmt.)
- #121617 (Actually use the right closure kind when checking async Fn goals)
- #121628 (Do not const prop unions)
- #121629 (fix some references to no-longer-existing ReprOptions.layout_seed)
r? `@ghost`
`@rustbot` modify labels: rollup
By changing some attributes to only_local, reducing encoding attributes in the crate metadate.
Thank you.
This is part of changing attributes to only_local. I hope get your opinion whether I should split into multiple PRs, or submit in one.
According to [try to not rely on attributes from extern crates](https://github.com/rust-lang/compiler-team/issues/505) and lcnr's guidance.
avoid generalization inside of aliases
The basic idea of this PR is that we don't generalize aliases when the instantiation could fail later on, either due to the *occurs check* or because of a universe error. We instead replace the whole alias with an inference variable and emit a nested `AliasRelate` goal. This `AliasRelate` then fully normalizes the alias before equating it with the inference variable, at which point the alias can be treated like any other rigid type.
We now treat aliases differently depending on whether they are *rigid* or not. To detect whether an alias is rigid we check whether `NormalizesTo` fails. While we already do so inside of `AliasRelate` anyways, also doing so when instantiating a query response would be both ugly/difficult and likely inefficient. To avoid that I change `instantiate_and_apply_query_response` to relate types completely structurally. This change generally removes a lot of annoying complexity, which is nice. It's implemented by adding a flag to `Equate` to change it to structurally handle aliases.
We currently always apply constraints from canonical queries right away. By providing all the necessary information to the canonical query, we can guarantee that instantiating the query response never fails, which further simplifies the implementation. This does add the invariant that *any information which could cause instantiating type variables to fail must also be available inside of the query*.
While it's acceptable for canonicalization to result in more ambiguity, we must not cause the solver to incompletely structurally relate aliases by erasing information. This means we have to be careful when merging universes during canonicalization. As we only generalize for type and const variables we have to make sure that anything nameable by such a type or const variable inside of the canonical query is also nameable outside of it. Because of this we both stop merging universes of existential variables when canonicalizing inputs, we put all uniquified regions into a higher universe which is not nameable by any type or const variable.
I will look into always replacing aliases with inference variables when generalizing in a later PR unless the alias references bound variables. This should both pretty much fix https://github.com/rust-lang/trait-system-refactor-initiative/issues/4. This may allow us to merge the universes of existential variables again by changing generalize to not consider their universe when deciding whether to generalize aliases. This requires some additional non-trivial changes to alias-relate, so I am leaving that as future work.
Fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/79. While it would be nice to decrement universe indices when existing a `forall`, that was surprisingly difficult and not necessary to fix this issue. I am really happy with the approach in this PR think it is the correct way forward to also fix the remaining cases of https://github.com/rust-lang/trait-system-refactor-initiative/issues/8.
only checking whether nested goals hold means that we don't consider
their inference constraints. Given that we now emit `AliasRelate` when relating
aliases and infer vars, this previously resulted in an "unconstrained" inference var
in `coerce_unsized`.
Fix more #121208 fallout (round 3)
#121208 converted lots of delayed bugs to bugs. Unsurprisingly, there were a few invalid conversion found via fuzzing.
r? `@lcnr`
Split Diagnostics for Uncommon Codepoints: Add Individual Identifier Types
This pull request further modifies the `uncommon_codepoints` lint, adding the individual identifier types of `Technical`, `Not_NFKC`, `Exclusion` and `Limited_Use` to the diagnostic message.
Example rendered diagnostic:
```
error: identifier contains a Unicode codepoint that is not used in normalized strings: 'ij'
--> $DIR/lint-uncommon-codepoints.rs:6:4
|
LL | fn dijkstra() {}
| ^^^^^^^
= note: this character is included in the Not_NFKC Unicode general security profile
```
Second step of #120228.
