Use `nuw` when calculating slice lengths from `Range`s
An `assume` would definitely not be worth it, but since the flag is almost free we might as well tell LLVM this, especially on `_unchecked` calls where there's no obvious way for it to deduce it.
(Today neither safe nor unsafe indexing gets it: <https://rust.godbolt.org/z/G1jYT548s>)
fix multiple issues when promoting type-test subject
Multiple interdependent fixes. See linked issues for a short description of each.
When Promoting a type-test `T: 'a` from within the closure back to its parent function, there are a couple pre-existing bugs and limitations. They were exposed by the recent changes to opaque types because the type-test subject (`T`) is no longer a simple ParamTy.
Commit 1:
Fixes#108635Fixes#107426
Commit 2:
Fixes#108639
Commit 3:
Fixes#107516
Rollup of 8 pull requests
Successful merges:
- #107801 (const_eval: `implies_by` in `rustc_const_unstable`)
- #108750 (Fix `ObligationCtxt::sub`)
- #108780 (Add regression tests for issue 70919)
- #108786 (Check for free regions in MIR validation)
- #108790 (Do not ICE when interpreting a cast between non-monomorphic types)
- #108803 (Do not ICE when failing to normalize in ConstProp.)
- #108807 (Emit the suspicious_auto_trait_impls for negative impls as well)
- #108812 (Add regression test for #98444)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Do not ICE when failing to normalize in ConstProp.
There is no reason to delay a bug there, as we bubble up the failure as TooGeneric.
Fixes https://github.com/rust-lang/rust/issues/97728
Add regression tests for issue 70919
Desugaring DropAndReplace at MIR build (#107844) fixed#70919.
Add regressions tests, borrowed from #102078, to ensure we check for this in the future.
cc ``@Aaron1011``
const_eval: `implies_by` in `rustc_const_unstable`
Fixes#107605.
Extend support for `implies_by` (from `#[stable]` and `#[unstable]`) to `#[rustc_const_stable]` and `#[rustc_const_unstable]`.
cc ``@steffahn``
Allow using `bool` instead of `Option<()>` in diagnostics
~~Disallow the unit type for `#[help]`, `#[note]` etc, instead using `bool` to express optional annotations without a span which I believe is more intuitive.~~
~~Test output ordering has changed in a few places, where a field was of type `()` and the annotation has been moved to the struct itself. If any of these changes are an issue, this can be restricted to allowing specifically `()`, and not `Option<()>`~~
~~Actual changes here: https://github.com/rust-lang/rust/pull/108402/files#diff-815b1d8debfc564112bd51093791d7c3f2ee288a37a8f5c0e89c11d1f609b4c0~~
Allows using `bool` in derive diagnostics to indicate an optional subdiagnostic without a span, where previously `Option<()>` had to be used
`@rustbot` label +A-diagnostics
Rollup of 7 pull requests
Successful merges:
- #108244 (Add test for semicolon recovery ICE)
- #108746 (Don't project to RPITIT that has no default value)
- #108764 (Tweaks to -Zdrop-tracking-mir)
- #108770 (Improve documentation and argument naming of some TyCtxt methods)
- #108773 (x fmt: Only check modified files locally)
- #108775 (Use the correct bound vars in return type suggestion.)
- #108776 (Make `x test tidy` less noisy)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
An `assume` would definitely not be worth it, but since the flag is almost free we might as well tell LLVM this, especially on `_unchecked` calls where there's no obvious way for it to deduce it.
(Today neither safe nor unsafe indexing gets it: <https://rust.godbolt.org/z/G1jYT548s>)
Use `partial_cmp` to implement tuple `lt`/`le`/`ge`/`gt`
In today's implementation, `(A, B)::gt` contains calls to *both* `A::eq` *and* `A::gt`.
That's fine for primitives, but for things like `String`s it's kinda weird -- `(String, usize)::gt` has a call to both `bcmp` and `memcmp` (<https://rust.godbolt.org/z/7jbbPMesf>) because when `bcmp` says the `String`s aren't equal, it turns around and calls `memcmp` to find out which one's bigger.
This PR changes the implementation to instead implement `(A, …, C, Z)::gt` using `A::partial_cmp`, `…::partial_cmp`, `C::partial_cmp`, and `Z::gt`. (And analogously for `lt`, `le`, and `ge`.) That way expensive comparisons don't need to be repeated.
Technically this is an observable change on stable, so I've marked it `needs-fcp` + `T-libs-api` and will
r? rust-lang/libs-api
I'm hoping that this will be non-controversial, however, since it's very similar to the observable changes that were made to the derives (#81384#98655) -- like those, this only changes behaviour if a type overrode behaviour in a way inconsistent with the rules for the various traits involved.
(The first commit here is #108156, adding the codegen test, which I used to make sure this doesn't regress behaviour for primitives.)
Zulip conversation about this change: <https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/.60.3E.60.20on.20Tuples/near/328392927>.
Desugaring DropAndReplace at MIR build (#107844) fixed issue
70919. Add regressions tests, borrowed from #102078, to ensure we
check for this in the future.
Co-authored-by: Aaron Hill <aa1ronham@gmail.com>
rustdoc-json: switch from HashMap to FxHashMap to fix non-determinism
Using `HashMap` in `rustdoc_json_types::Crate` were causing creating randomly ordered objects in the json doc files. Which might cause problems to people who are doing comparison on those files specially in CI pipelines. See https://github.com/rust-lang/rust/issues/103785#issuecomment-1307425590
This PR fixes that issue and extends the coverage of `tests/run-make/rustdoc-verify-output-files` testing ability.
Bless tests and show an introduced unsoundness related to
exits<'a> { forall<'b> { 'a == 'b } }.
We now resolve the var ?a in U0 to the placeholder !b in U1.
Desugaring of drop and replace at MIR build
This commit desugars the drop and replace deriving from an
assignment at MIR build, avoiding the construction of the
`DropAndReplace` terminator (which will be removed in a following PR).
In order to retain the same error messages for replaces a new
`DesugaringKind::Replace` variant is introduced.
The changes in the borrowck are also useful for future work in moving drop elaboration
before borrowck, as no `DropAndReplace` would be present there anymore.
Notes on test diffs:
* `tests/ui/borrowck/issue-58776-borrowck-scans-children`: the assignment deriving from the desugaring kills the borrow.
* `tests/ui/async-await/async-fn-size-uninit-locals.rs`, `tests/mir-opt/issue_41110.test.ElaborateDrops.after.mir`, `tests/mir-opt/issue_41888.main.ElaborateDrops.after.mir`: drop elaboration generates (or reads from) a useless drop flag due to an issue with the dataflow analysis. Will be fixed independently by https://github.com/rust-lang/rust/pull/106430.
See https://github.com/rust-lang/rust/pull/104488 for more context
Label opaque type for 'captures lifetime' error message
Providing more information may help make this somewhat opaque (lol) error message a bit clearer.
Clippy Fix array-size-threshold config deserialization error
Complementary PR to https://github.com/rust-lang/rust/pull/108673 in order to also get this into the **next** beta.
r? ``@Mark-Simulacrum``
Fix another ICE in `point_at_expr_source_of_inferred_type`
Types coming from method probes must only be investigated *structurally*, since they often contain escaping infer variables from generalization and autoderef. We already have a hack in this PR that erases variables from types, so just use that.
Fixes#108664
The note attached to this error is pretty bad:
```
here the type of `primes` is inferred to be `[_]`
```
But that's unrelated to the PR.
---
Side-note: This is a pretty easy to trigger beta regression, so I've nominated it. Alternatively, I'm slightly inclined to remove this code altogether until it can be reformulated to be more accurate and less ICEy.
Deny capturing late-bound non-lifetime param in anon const
Introduce a new AnonConstBoundary so we can detect when we capture a late-bound non-lifetime param with `non_lifetime_binders` enabled.
In the future, we could technically do something like introduce an early-bound parameter on the anon const, and stick the late-bound param in its substs (kinda like how we turn late-bound lifetimes in opaques into early-bound ones). But for now, just deny it so we don't ICE.
Fixes#108191
This commit desugars the drop and replace deriving from an
assignment at MIR build, avoiding the construction of the
DropAndReplace terminator (which will be removed in a followign PR)
In order to retain the same error messages for replaces a new
DesugaringKind::Replace variant is introduced.
Feed queries on impl side for RPITITs when using lower_impl_trait_in_trait_to_assoc_ty
I've added a test for traits that were already working and what I think is probably the last bit of infrastructure work needed.
In following PRs I'm going to start adding things TDD style, tests and code that make it work.
r? `@compiler-errors`
Make `ExprKind` the first field in `thir::Expr`
This makes its `Debug` impl print it first which is useful, as it's the most important part when looking at an expr.
Explain compile-time vs run-time difference in env!() error message
This PR is clarifying error message of `env!()` based on this user question: https://users.rust-lang.org/t/environment-variable-out-dir-is-undefined/90067
It makes it clear that `env!()` is for env variables defined at compile-time. There's special-case help text for common Cargo build script variables.
I've also rearranged the code to avoid allocating error message on the happy path when the env var is defined.
Point error span at Some constructor argument when trait resolution fails
This is a follow up to #108254 and #106477 which extends error span refinement to handle a case which I mistakenly believed was handled in #106477. The goal is to refine the error span depicted below:
```rs
trait Fancy {}
impl <T> Fancy for Option<T> where T: Iterator {}
fn want_fancy<F>(f: F) where F: Fancy {}
fn example() {
want_fancy(Some(5));
// (BEFORE) ^^^^^^^ `{integer}` is not an iterator
// (AFTER) ^ `{integer}` is not an iterator
}
```
I had used a (slightly more complex) example as an illustrative example in #108254 , but hadn't actually turned it into a test, because I had (incorrectly) believed at the time it was covered by existing behavior. It turns out that `Some` is slightly "special" in that it resolves differently from the other `enum` constructors I had tried, and therefore this test was actually broken.
I've now updated the tests to include this example, and fixed the code to correctly resolve the `Some` constructor so that the span of the error is reduced.
Revert stabilization of `#![feature(target_feature_11)]`
This reverts #99767 due to the presence of bugs #108645 and #108646.
cc `@joshtriplett`
cc tracking issue #69098
r? `@ghost`
Rollup of 5 pull requests
Successful merges:
- #108516 (Restrict `#[rustc_box]` to `Box::new` calls)
- #108575 (Erase **all** regions when probing for associated types on ambiguity in astconv)
- #108585 (Run compiler test suite in parallel on Fuchsia)
- #108606 (Add test case for mismatched open/close delims)
- #108609 (Highlight whole expression for E0599)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Highlight whole expression for E0599
Fixes#108603
This adds a secondary label to highlight the whole expression leading to the error. It also prevents empty labels being recognised as 'unexpected' by compiletest - otherwise, tests with NOTE annotations would pick up empty labels.
`@rustbot` label +A-diagnostics
Restrict `#[rustc_box]` to `Box::new` calls
Currently, `#[rustc_box]` can be applied to any call expression with a single argument. This PR only allows it to be applied to calls to `Box::new`
Add support for QNX Neutrino to standard library
This change:
- adds standard library support for QNX Neutrino (7.1).
- upgrades `libc` to version `0.2.139` which supports QNX Neutrino
`@gh-tr`
⚠️ Backtraces on QNX require https://github.com/rust-lang/backtrace-rs/pull/507 which is not yet merged! (But everything else works without these changes) ⚠️
Tested mainly with a x86_64 virtual machine (see qnx-nto.md) and partially with an aarch64 hardware (some tests fail due to constrained resources).
Merge two different equality specialization traits in `core`
Arrays and slices each had their own version of this, without a matching set of `impl`s.
Merge them into one (still-`pub(crate)`) `cmp::BytewiseEq` trait, so we can stop doing all these things twice.
And that means that the `[T]::eq` → `memcmp` specialization picks up a bunch of types where that previously only worked for arrays, so examples like <https://rust.godbolt.org/z/KjsG8MGGT> will use it now instead of emitting loops.
r? the8472
Rollup of 7 pull requests
Successful merges:
- #108143 (rustdoc: search by macro when query ends with `!`)
- #108394 (Make `x doc --open` work on every book)
- #108427 (Recover from for-else and while-else)
- #108462 (Fix `VecDeque::append` capacity overflow for ZSTs)
- #108568 (Make associated_item_def_ids for traits use an unstable option to also return associated types for RPITITs)
- #108604 (Add regression test for #107280)
- #108605 (Add regression test for #105821)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Recover from for-else and while-else
This recovers from attempts at writing for-else or while-else loops, which might help users coming from e.g. Python.
```rs
for _ in 0..0 {
// ...
} else {
// ...
}
```
Combined with trying to store it in a let binding, the current diagnostic can be a bit confusing. It mentions let-else and suggests wrapping the loop in parentheses, which the user probably doesn't want. let-else doesn't make sense for `for` and `while` loops, as they are of type `()` (which already is an irrefutable pattern and doesn't need let-else).
<details>
<summary>Current diagnostic</summary>
```rs
error: right curly brace `}` before `else` in a `let...else` statement not allowed
--> src/main.rs:4:5
|
4 | } else {
| ^
|
help: wrap the expression in parentheses
|
2 ~ let _x = (for _ in 0..0 {
3 |
4 ~ }) else {
|
```
</details>
Some questions:
- Can the wording for the error message be improved? Would "for...else loops are not allowed" fit better?
- Should we be more "conservative" in case we want to support this in the future (i.e. say "for...else loops are **currently** not allowed/supported")?
- Is there a better way than storing a `&'static str` for the loop type? It is used for substituting the placeholder in the locale file (since it can emit either `for...else` or `while...else`). Maybe there is an enum I could use that I couldn't find
Name LLVM anonymous constants by a hash of their contents
This makes the names stable between different versions of a crate unlike the `AllocId` naming, making LLVM IR comparisons with `llvm-diff` more practical.
Add `Option::as_`(`mut_`)`slice`
This adds the following functions:
* `Option<T>::as_slice(&self) -> &[T]`
* `Option<T>::as_mut_slice(&mut self) -> &[T]`
The `as_slice` and `as_mut_slice_mut` functions benefit from an optimization that makes them completely branch-free. ~~Unfortunately, this optimization is not available on by-value Options, therefore the `into_slice` implementations use the plain `match` + `slice::from_ref` approach.~~
Note that the optimization's soundness hinges on the fact that either the niche optimization makes the offset of the `Some(_)` contents zero or the mempory layout of `Option<T>` is equal to that of `Option<MaybeUninit<T>>`.
The idea has been discussed on [Zulip](https://rust-lang.zulipchat.com/#narrow/stream/219381-t-libs/topic/Option.3A.3Aas_slice). Notably the idea for the `as_slice_mut` and `into_slice´ methods came from `@cuviper` and `@Sp00ph` hardened the optimization against niche-optimized Options.
The [rust playground](https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=74f8e4239a19f454c183aaf7b4a969e0) shows that the generated assembly of the optimized method is basically only a copy while the naive method generates code containing a `test dx, dx` on x86_64.
---
EDIT from reviewer: ACP is https://github.com/rust-lang/libs-team/issues/150
Only look for param in item's generics if it actually comes from generics
Record whether a `hir::GenericParam` comes from an item's generics, or from a `for<...>` binder. Then, only look for the param in `object_lifetime_default` if it actually comes from the item's generics.
Fixes#108177
This adds the following functions:
* `Option<T>::as_slice(&self) -> &[T]`
* `Option<T>::as_slice_mut(&mut self) -> &[T]`
The `as_slice` and `as_slice_mut` functions benefit from an
optimization that makes them completely branch-free.
Note that the optimization's soundness hinges on the fact that either
the niche optimization makes the offset of the `Some(_)` contents zero
or the mempory layout of `Option<T>` is equal to that of
`Option<MaybeUninit<T>>`.
Stabilize `#![feature(target_feature_11)]`
## Stabilization report
### Summary
Allows for safe functions to be marked with `#[target_feature]` attributes.
Functions marked with `#[target_feature]` are generally considered as unsafe functions: they are unsafe to call, cannot be assigned to safe function pointers, and don't implement the `Fn*` traits.
However, calling them from other `#[target_feature]` functions with a superset of features is safe.
```rust
// Demonstration function
#[target_feature(enable = "avx2")]
fn avx2() {}
fn foo() {
// Calling `avx2` here is unsafe, as we must ensure
// that AVX is available first.
unsafe {
avx2();
}
}
#[target_feature(enable = "avx2")]
fn bar() {
// Calling `avx2` here is safe.
avx2();
}
```
### Test cases
Tests for this feature can be found in [`src/test/ui/rfcs/rfc-2396-target_feature-11/`](b67ba9ba20/src/test/ui/rfcs/rfc-2396-target_feature-11/).
### Edge cases
- https://github.com/rust-lang/rust/issues/73631
Closures defined inside functions marked with `#[target_feature]` inherit the target features of their parent function. They can still be assigned to safe function pointers and implement the appropriate `Fn*` traits.
```rust
#[target_feature(enable = "avx2")]
fn qux() {
let my_closure = || avx2(); // this call to `avx2` is safe
let f: fn() = my_closure;
}
```
This means that in order to call a function with `#[target_feature]`, you must show that the target-feature is available while the function executes *and* for as long as whatever may escape from that function lives.
### Documentation
- Reference: https://github.com/rust-lang/reference/pull/1181
---
cc tracking issue #69098
r? `@ghost`
Avoid invoking typeck from borrowck
This PR attempts to reduce direct dependencies between typeck and MIR-related queries. The goal is to have all the information transit either through THIR or through dedicated queries that avoid depending on the whole `TypeckResults`.
In a first commit, we store the type information that MIR building requires into THIR. This avoids edges between mir_built and typeck.
In the second and third commit, we wrap informations around closures (upvars, kind origin and user-provided signature) to avoid borrowck depending on typeck information.
There should be a single remaining borrowck -> typeck edge in the good path, due to inline consts.
Commit some new solver tests
Lazy norm is hard.
`<?0 as Trait>::Assoc = ?0` ... probably should emit an alias-eq goal, but currently we don't do that. Right now it fails with a cyclical ty error.
Also committed a check-pass test that broken when I attempted to fix this (unsuccessfully).
r? types
Move IpAddr, SocketAddr and V4+V6 related types to `core`
Implements RFC https://github.com/rust-lang/rfcs/pull/2832. The RFC has completed FCP with disposition merge, but is not yet merged.
Moves IP types to `core` as specified in the RFC.
The full list of moved types is: `IpAddr`, `Ipv4Addr`, `Ipv6Addr`, `SocketAddr`, `SocketAddrV4`, `SocketAddrV6`, `Ipv6MulticastScope` and `AddrParseError`.
Doing this move was one of the main driving arguments behind #78802.
MIR-Validate StorageLive.
`StorageLive` statements on a local which already has storage is banned by miri.
This check is easy enough, and can detect bugs in MIR opts.
Don't project specializable RPITIT projection
This effective rejects specialization + RPITIT/AFIT (usages of `impl Trait` in traits) because the implementation is significantly complicated over making regular "default" trait method bodies work.
I have another PR that experimentally fixes all this, but the code may not be worth investing in.
Treat `str` as containing `[u8]` for auto trait purposes
Wanted to gauge ``@rust-lang/lang`` and ``@rust-lang/types`` teams' thoughts on treating `str` as "containing" a `[u8]` slice for auto-trait purposes.
``@dtolnay`` brought this up in https://github.com/rust-lang/rust/issues/13231#issuecomment-1399386472 as a blocker for future `str` type librarification, and I think it's both a valid concern and very easy to fix. I'm interested in actually doing that `str` type librarification (#107939), but this probably should be considered in the mean time regardless of that PR.
r? types for the impl, though this definitely needs an FCP.
Rollup of 8 pull requests
Successful merges:
- #107062 (Do some cleanup of doc/index.md)
- #107890 (Lint against `Iterator::map` receiving a callable that returns `()`)
- #108431 (Add regression test for #107918)
- #108432 (test: drop unused deps)
- #108436 (make "proc macro panicked" translatable)
- #108444 (docs/test: add UI test and docs for `E0476`)
- #108449 (Do not lint ineffective unstable trait impl for unresolved trait)
- #108456 (Complete migrating `ast_passes` to derive diagnostics)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
docs/test: add UI test and docs for `E0476`
Final undocumented error code. Not entirely sure about wording in the docs.
Part of https://github.com/rust-lang/rust/issues/61137.
r? ```@compiler-errors```
cc ```@compiler-errors```
Implement -Zlink-directives=yes/no
`-Zlink-directives=no` will ignored `#[link]` directives while compiling a crate, so nothing is emitted into the crate's metadata. The assumption is that the build system already knows about the crate's native dependencies and can provide them at link time without these directives.
This is another way to address issue # #70093, which is currently addressed by `-Zlink-native-libraries` (implemented in #70095). The latter is implemented at link time, which has the effect of ignoring `#[link]` in *every* crate. This makes it a very large hammer as it requires all native dependencies to be known to the build system to be at all usable, including those in sysroot libraries. I think this means its effectively unused, and definitely under-used.
Being able to control this on a crate-by-crate basis should make it much easier to apply when needed.
I'm not sure if we need both mechanisms, but we can decide that later.
cc `@pcwalton` `@cramertj`
[breaking change] Remove a rustdoc back compat warning
This warning was introduced in https://github.com/rust-lang/rust/pull/62855 for users who use `rustdoc` directly on proc macro crates (instead of using `cargo doc`) without passing `--crate-type proc-macro` (which `cargo doc` passed automatically).
Move some std tests from `tests/ui-fulldeps` into `library/std`
This allows them to be tested normally along with other `./x test std` tests. Moving `rename_directory` is simple enough but `create_dir_all_bare` needed to be an std integration test.
Additionally, some tests that I couldn't move atm have instead been placed in an `std` subdirectory. These tests include ones that do fun things with processes or that intentionally abort the test process.
r? libs
Remove dead unwinds before drop elaboration
As a part of drop elaboration, we identify dead unwinds, i.e., unwind
edges on a drop terminators which are known to be unreachable, because
there is no need to drop anything.
Previously, the data flow framework was informed about the dead unwinds,
and it assumed those edges are absent from MIR. Unfortunately, the data
flow framework wasn't consistent in maintaining this assumption.
In particular, if a block was reachable only through a dead unwind edge,
its state was propagated to other blocks still. This became an issue in
the context of change removes DropAndReplace terminator, since it
introduces initialization into cleanup blocks.
To avoid this issue, remove unreachable unwind edges before the drop
elaboration, and elaborate only blocks that remain reachable.
cc `@Zeegomo`
diagnostics: remove inconsistent English article "this" from E0107
Consider [`tests/ui/const-generics/generic_const_exprs/issue-102768.stderr`][issue-102768.stderr], the error message where it gives additional notes about where the associated type is defined, and how the dead code lint doesn't have an article, like in [`tests/ui/lint/dead-code/issue-85255.stderr`][issue-85255.stderr]. They don't have articles, so it seems unnecessary to have one here.
[issue-102768.stderr]: 07c993eba8/tests/ui/const-generics/generic_const_exprs/issue-102768.stderr
[issue-85255.stderr]: 07c993eba8/tests/ui/lint/dead-code/issue-85255.stderr
parser: provide better suggestions and errors on closures with braces missing
We currently provide wrong suggestions and unhelpful errors on closure bodies with braces missing.
For example, given the following code:
```rust
fn main() {
let _x = Box::new(|x|x+1;);
}
```
the current output is:
```
error: expected expression, found `)`
--> ./main.rs:2:30
|
2 | let _x = Box::new(|x|x+1;);
| ^ expected expression
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^
3 | }
| ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ this is the parsed closure...
3 | }
| - ...but likely you meant the closure to end here
help: try adding braces
|
2 ~ let _x = Box::new(|x| {x+1;);
3 ~ }}
|
error: expected `;`, found `}`
--> ./main.rs:2:32
|
2 | let _x = Box::new(|x|x+1;);
| ^ help: add `;` here
3 | }
| - unexpected token
error: aborting due to 3 previous errors
```
We got 3 errors, but all but the second are unnecessary or just wrong.
This commit allows outputting correct suggestions and errors. The above code would output like this:
```
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^ ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ - ...but likely you meant the closure to end here
| |
| this is the parsed closure...
help: try adding braces
|
2 | let _x = Box::new(|x| {x+1;});
| + +
error: aborting due to previous error
```
Fixes https://github.com/rust-lang/rust/issues/107959.
r? diagnostics
Fix ICE in 'duplicate diagnostic item' diagnostic
Not sure how to add this in a test; I found it by mistakenly running `cargo fix --lib -p std` rather than `x fix` at the root.
Add test for bad cast with deferred projection equality
1. Unification during coercion (`Coerce::unify`) needs to consider deferred projection obligations (at least pass over them with `predicate_may_hold` or something, to disqualify any totally wrong unifications) -- otherwise, we'll shallowly consider `<u8 as Add>::Output` and `char` as coercible during `FnCtxt::try_coerce`, which will fail later when the nested obligations are registered and processed.
2. Cast checking needs to be able to structurally normalize types so it sees `u8` instead of `<u8 as Add>::Output`. Otherwise it'll always consider the latter as part of a non-primitive cast. Currently `FnCtxt::normalize` doesn't do anything useful here, interestingly.
I tried looking into both of these and it's not immediately clear where to refactor existing typeck code to fix this (at least the latter), but I'm gonna commit a test for it at least so we don't forget. This is one of the issues that's keeping us from building larger projects.
implement const iterator using `rustc_do_not_const_check`
Previous experiment: #102225.
Explanation: rather than making all default methods work under `const` all at once, this uses `rustc_do_not_const_check` as a workaround to "trick" the compiler to not run any checks on those other default methods. Any const implementations are only required to implement the `next` method. Any actual calls to the trait methods other than `next` will either error in compile time (at CTFE runs), or run the methods correctly if they do not have any non-const operations. This is extremely easy to maintain, remove, or improve.
Consider `tests/ui/const-generics/generic_const_exprs/issue-102768.stderr`,
the error message where it gives additional notes about where the associated
type is defined, and how the dead code lint doesn't have an article,
like in `tests/ui/lint/dead-code/issue-85255.stderr`. They don't have
articles, so it seems unnecessary to have one here.
We currently provide wrong suggestions and unhelpful errors on closure
bodies with braces missing. For example, given the following code:
```
fn main() {
let _x = Box::new(|x|x+1;);
}
```
the current output is like this:
```
error: expected expression, found `)`
--> ./main.rs:2:30
|
2 | let _x = Box::new(|x|x+1;);
| ^ expected expression
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^
3 | }
| ^
|
...
help: try adding braces
|
2 ~ let _x = Box::new(|x| {x+1;);
3 ~ }}
...
error: expected `;`, found `}`
--> ./main.rs:2:32
|
2 | let _x = Box::new(|x|x+1;);
| ^ help: add `;` here
3 | }
| - unexpected token
error: aborting due to 3 previous errors
```
This commit allows outputting correct suggestions and errors. The above
code would output like this:
```
error: closure bodies that contain statements must be surrounded by braces
--> ./main.rs:2:25
|
2 | let _x = Box::new(|x|x+1;);
| ^ ^
|
note: statement found outside of a block
--> ./main.rs:2:29
|
2 | let _x = Box::new(|x|x+1;);
| ---^ this `;` turns the preceding closure into a statement
| |
| this expression is a statement because of the trailing semicolon
note: the closure body may be incorrectly delimited
--> ./main.rs:2:23
|
2 | let _x = Box::new(|x|x+1;);
| ^^^^^^ - ...but likely you meant the closure to end here
| |
| this is the parsed closure...
help: try adding braces
|
2 | let _x = Box::new(|x| {x+1;});
| + +
error: aborting due to previous error
```
rustdoc: Prevent duplicated imports
Fixes#108163.
Interestingly enough, the AST is providing us an import for each corresponding item, even though the `Res` links to multiple ones each time, which leaded to the same import being duplicated.
So in this PR, I decided to prevent the add of the import before the clean pass. However, I originally took a different path by instead filtering after cleaning the path. You can see it [here](https://github.com/rust-lang/rust/compare/master...GuillaumeGomez:rust:fix-duplicated-imports?expand=1). Only the second commit differs.
I think this approach is better though, but at least we can compare both if we want.
The first commit adds the check for duplicated items in the rustdoc-json output as asked in #108163.
cc `@aDotInTheVoid`
r? `@notriddle`
Correctly handle aggregates in DataflowConstProp
The previous implementation from https://github.com/rust-lang/rust/pull/107411 flooded target of an aggregate assignment with `Bottom`, corresponding to the `deinit` that the interpreter does.
As a consequence, when assigning `target = Enum::Variant#i(...)` all the `(target as Variant#j)` were at `Bottom` while they should have been `Top`.
This PR replaces that flooding with `Top`.
Aside, it corrects a second bug where the wrong place would be used to assign to enum variant fields, resulting to nothing happening.
Fixes https://github.com/rust-lang/rust/issues/108166
Ban associated type bounds in bad positions
We should not try to lower associated type bounds into TAITs in positions where `impl Trait` is not allowed (except for in `where` clauses, like `where T: Trait<Assoc: Bound>`).
This is achieved by using the same `rustc_ast_lowering` machinery as impl-trait does to characterize positions as universal/existential/disallowed.
Fixes#106077
Split out the first commit into #108066, since it's not really related.
Lint dead code in closures and generators
Fixes#108296
I think this might be a potentially breaking change, but restores the behaviour of pre-1.64.
`@rustbot` label +A-lint
Don't delay `ReError` bug during lexical region resolve
Lexical region resolution returns a list of `RegionResolutionError` which don't necessarily correspond to diagnostics being emitted. The compiler may, validly, throw away these resolution errors and do something else. Therefore it's not valid to use `ReError` during lifetime resolution, since we may actually be on a totally fine compilation path.
For example, the `implied_bounds_entailment` lint runs region resolution twice, and only emits an error if it fails both times. If we delay a bug and create a `ReError` during this first run, then we will ICE.
Fixes#108170
----
Side-note: this is conceptually equivalent to how we can't necessarily delay bugs or create `ty::Error` during trait solving/fulfillment, since the compiler is allowed to throw away these fulfillment errors to do other things. It's only once we actually emit an error (`report_region_errors` / `report_fulfillment_errors`)
Remove type-traversal trait aliases
#107924 moved the type traversal (folding and visiting) traits into the type library, but created trait aliases in `rustc_middle` to minimise both the API churn for trait consumers and the arising boilerplate. As mentioned in that PR, an alternative approach of defining subtraits with blanket implementations of the respective supertraits was also considered at that time but was ruled out as not adding much value.
Unfortunately, it has since emerged that rust-analyzer has difficulty with these trait aliases at present, resulting in a degraded contributor experience (see the recent [r-a has become useless](https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/r-a.20has.20become.20useless) topic on the #t-compiler/help Zulip stream).
This PR removes the trait aliases, and accordingly the underlying type library traits are now used directly; they are parameterised by `TyCtxt<'tcx>` rather than just the `'tcx` lifetime, and imports have been updated to reflect the fact that the trait aliases' explicitly named traits are no longer automatically brought into scope. These changes also roll-back the (no-longer required) workarounds to #107747 that were made in b409329c62.
Since this PR is just a find+replace together with the changes necessary for compilation & tidy to pass, it's currently just one mega-commit. Let me know if you'd like it broken up.
r? `@oli-obk`
`-Zlink-directives=no` will ignored `#[link]` directives while compiling a
crate, so nothing is emitted into the crate's metadata. The assumption is
that the build system already knows about the crate's native dependencies
and can provide them at link time without these directives.
This is another way to address issue # #70093, which is currently addressed
by `-Zlink-native-libraries` (implemented in #70095). The latter is
implemented at link time, which has the effect of ignoring `#[link]`
in *every* crate. This makes it a very large hammer as it requires all
native dependencies to be known to the build system to be at all usable,
including those in sysroot libraries. I think this means its effectively
unused, and definitely under-used.
Being able to control this on a crate-by-crate basis should make it much
easier to apply when needed.
I'm not sure if we need both mechanisms, but we can decide that later.
errors: generate typed identifiers in each crate
Instead of loading the Fluent resources for every crate in `rustc_error_messages`, each crate generates typed identifiers for its own diagnostics and creates a static which are pulled together in the `rustc_driver` crate and provided to the diagnostic emitter.
There are advantages and disadvantages to this change..
#### Advantages
- Changing a diagnostic now only recompiles the crate for that diagnostic and those crates that depend on it, rather than `rustc_error_messages` and all crates thereafter.
- This approach can be used to support first-party crates that want to supply translatable diagnostics (e.g. `rust-lang/thorin` in https://github.com/rust-lang/rust/pull/102612#discussion_r985372582, cc `@JhonnyBillM)`
- We can extend this a little so that tools built using rustc internals (like clippy or rustdoc) can add their own diagnostic resources (much more easily than those resources needing to be available to `rustc_error_messages`)
#### Disadvantages
- Crates can only refer to the diagnostic messages defined in the current crate (or those from dependencies), rather than all diagnostic messages.
- `rustc_driver` (or some other crate we create for this purpose) has to directly depend on *everything* that has error messages.
- It already transitively depended on all these crates.
#### Pending work
- [x] I don't know how to make `rustc_codegen_gcc`'s translated diagnostics work with this approach - because `rustc_driver` can't depend on that crate and so can't get its resources to provide to the diagnostic emission. I don't really know how the alternative codegen backends are actually wired up to the compiler at all.
- [x] Update `triagebot.toml` to track the moved FTL files.
r? `@compiler-errors`
cc #100717
Fix overlapping spans in removing extra arguments
Fixes#108225
Each span is already extended to include the previous comma, so extending to the *next* comma is unecessary and causes an ICE with assertions on.
``@rustbot`` label +A-diagnostics
Convert a hard-warning about named static lifetimes into lint "unused_lifetimes"
Fixes https://github.com/rust-lang/rust/issues/96956.
Some changes are ported from https://github.com/rust-lang/rust/pull/98079, thanks to jeremydavis519.
r? `@estebank` `@petrochenkov`
Any feedback is appreciated!
## Actions
- [x] resolve conflicts
- [x] fix build
- [x] address review comments in last pr
- [x] update tests
Extend `CodegenBackend` trait with a function returning the translation
resources from the codegen backend, which can be added to the complete
list of resources provided to the emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
`run-make/translation` had some targets that weren't listed in `all` and
thus weren't being tested - the behaviour that should have been being
tested was basically correct fortunately.
Signed-off-by: David Wood <david.wood@huawei.com>
Instead of loading the Fluent resources for every crate in
`rustc_error_messages`, each crate generates typed identifiers for its
own diagnostics and creates a static which are pulled together in the
`rustc_driver` crate and provided to the diagnostic emitter.
Signed-off-by: David Wood <david.wood@huawei.com>
Define the `named_static_lifetimes` lint
This lint will replace the existing hard-warning.
Replace the named static lifetime hard-warning with the new lint
Update the UI tests for the `named_static_lifetimes` lint
Remove the direct dependency on `rustc_lint_defs`
fix build
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
use "UNUSED_LIFETIMES" instead
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
update 1 test and fix typo
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
update tests
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
fix tests: add extra blank line
Signed-off-by: Zhi Qi <qizhi@pingcap.com>
Use DefKind to give more item kind information during BindingObligation note
The current label says "required by a bound in this". When I see that label, my immediate impression is "this... **what**?". It feels like it was cut short.
Alternative to this would be saying "in this item", but adding the item kind is strictly more informational and adds very little overhead to the existing error presentation.
