When encountering a move error involving a closure because the captured value isn't `Copy`, and the obligation comes from a bound on a type parameter that requires `Fn` or `FnMut`, we point at it and explain that an `FnOnce` wouldn't cause the move error.
```
error[E0507]: cannot move out of `foo`, a captured variable in an `Fn` closure
--> f111.rs:15:25
|
14 | fn do_stuff(foo: Option<Foo>) {
| --- ----------- move occurs because `foo` has type `Option<Foo>`, which does not implement the `Copy` trait
| |
| captured outer variable
15 | require_fn_trait(|| async {
| -- ^^^^^ `foo` is moved here
| |
| captured by this `Fn` closure
16 | if foo.map_or(false, |f| f.foo()) {
| --- variable moved due to use in coroutine
|
help: `Fn` and `FnMut` closures require captured values to be able to be consumed multiple times, but an `FnOnce` consume them only once
--> f111.rs:12:53
|
12 | fn require_fn_trait<F: Future<Output = ()>>(_: impl Fn() -> F) {}
| ^^^^^^^^^
help: consider cloning the value if the performance cost is acceptable
|
16 | if foo.clone().map_or(false, |f| f.foo()) {
| ++++++++
```
When trying to construct a struct that has a public field of a private type, suggest using `..` if that field has a default value.
```
error[E0603]: struct `Priv1` is private
--> $DIR/non-exhaustive-ctor.rs:25:39
|
LL | let _ = S { field: (), field1: m::Priv1 {} };
| ------ ^^^^^ private struct
| |
| while setting this field
|
note: the struct `Priv1` is defined here
--> $DIR/non-exhaustive-ctor.rs:14:4
|
LL | struct Priv1 {}
| ^^^^^^^^^^^^
help: the field `field1` you're trying to set has a default value, you can use `..` to use it
|
LL | let _ = S { field: (), .. };
| ~~
```
Start reporting future breakage for `ILL_FORMED_ATTRIBUTE_INPUT` in dependencies
This has been a warn lint since early 2019 and a deny-by-default lint since late 2019.
We're currently transitioning some of the cases where this lint is being produced to a hard error (https://github.com/rust-lang/rust/pull/143607https://github.com/rust-lang/rust/pull/143808 and more)
So let's report this lint in all dependencies for the remaining attributes
r? `@traviscross`
`@rustbot` labels +I-lang-nominated +T-lang -T-compiler
cc `@jdonszelmann`
(Separate question: Why does the "Future incompatibility report" only trigger if `report_in_deps` is true, even if the future incompatibility happens in the same crate, is this correct?)
This also needs a crater run, but I don't have permissions to trigger this
When doing lto, rustc generates filenames that are concatenating many information.
In the case of this testcase, it is concatenating crate name and rust file name, plus some hash, and the extension.
In some other cases it will concatenate even more information reducing the maximum effective crate name to about 110 chars on linux filesystems where
filename max length is 255
This commit is ensuring that the temporary file names are limited in size, while still reasonabily ensuring the unicity (with hashing of the stripped part)
`suggest_borrow_generic_arg`: use the correct generic args
The suggestion now gets calls' generic arguments from the callee's type to handle cases where the callee isn't an identifier expression. Fixesrust-lang/rust#145164.
Fix an unstable feature comment that wasn't a doc comment
Every other feature in the list uses a doc comment; fix one that used a regular comment to use a doc comment.
some `derive_more` refactors
some clauses can be merged together without requiring an attribute for each trait derived.
also manually impl `Eq` because the `derive_where` generated code is too much for my comfort (cc https://github.com/ModProg/derive-where/pull/128)
Simplify polonius location-sensitive analysis
This PR reworks the location-sensitive analysis into what we think is a worthwhile subset of the datalog analysis. A sort of polonius alpha analysis that handles NLL problem case 3 and more, but is still using the faster "reachability as an approximation of liveness", as well as the same loans-in-scope computation as NLLs -- and thus doesn't handle full flow-sensitivity like the datalog implementation.
In the last few months, we've identified this subset as being actionable:
- we believe we can make a stabilizable version of this analysis
- it is an improvement over the status quo
- it can also be modeled in a-mir-formality, or some other formalism, for assurances about soundness, and I believe ````````@nikomatsakis```````` is interested in looking into this during H2.
- and we've identified the areas of work we wish to explore later to gradually expand the supported cases: the differences between reachability and liveness, support of kills, and considerations of time-traveling, for example.
The approach in this PR is to try less to have the graph only represent live paths, by checking whether we reach a live region during traversal and recording the loan as live there, instead of equating traversal with liveness like today because it has subtleties with the typeck edges in statements (that could forward loans to the successor point without ensuring their liveness). We can then also simplify these typeck stmt edges. And we also can simplify traversal by removing looking at kills, because that's enough to handle a bunch of NLL problem 3 cases -- and we can gradually support them more and more in traversal in the future, to reduce the approximation of liveness.
There's still some in-progress pieces of work w/r/t opaque types that I'm expecting [lcnr's opaque types rework](https://github.com/rust-lang/rust/pull/139587), and [amanda's SCCs rework](https://github.com/rust-lang/rust/pull/130227) to handle. That didn't seem to show up in tests until I rebased today (and shows lack of test coverage once again) when https://github.com/rust-lang/rust/pull/142255 introduced a couple of test failures with the new captures rules from edition 2024. It's not unexpected since we know more work is needed with member constraints (and we're not even using SCCs in this prototype yet)
I'll look into these anyways, both for future work, and checking how these other 2 PRs would change things.
---
I'm not sure the following means a lot until we have some formalism in-place, but:
- I've changed the polonius compare-mode to use this analysis: the tests pass with it, except 2 cases with minor diagnostics differences, and the 2 edition 2024 opaque types one I mentioned above and need to investigate
- things that are expected to work still do work: it bootstraps, can run our rustc-perf benchmarks (and the results are not even that bad), and a crater run didn't find any regressions (forgetting that crater currently fails to test around a quarter of all crates 👼)
- I've added tests with improvements, like the NLL problem case 3 and others, as well as some that behave the same as NLLs today and are thus worse than the datalog implementation
r? ````````@jackh726````````
(no rush I know you're deep in phd work and "implmentating" the new trait solver for r-a :p <3)
This also fixesrust-lang/rust#135646, a diagnostics ICE from the previous implementation.
Implement `stability_implications` without a visitor.
Since https://github.com/rust-lang/rust/pull/143845, the `Annotator` visitor was a no-op when the crate is not staged_api. This PR avoids using a visitor altogether, making `stability_implications` truly a no-op in most cases.
some clauses can be merged together without requiring an attribute for
each trait derived.
also manually impl `Eq` because the `derive_where` generated code is too
much for my comfort
defer opaque type errors, generally greatly reduce tainting
fixes the test for rust-lang/rust#135528, does not actually fix that issue properly.
This is useful as it causes the migration to rust-lang/rust#139587 to be a lot easier.
rustc_metadata: remove unused private trait impls
These are impls for non-reachable traits that don't appear to be used. Please let me know if there is value in keeping some of them for now.
cc `@cjgillot`
Escape diff strings in MIR dataflow graphviz
This uses `dot::escape_html` on diff strings so that `<` and `>` are properly escaped in MIR dataflow graphviz.
Previously the output could be malformed. For example, the graphviz for borrow check `MaybeInitializedPlaces` for the example in rust-lang/rust#145032 contained an unescaped `Fork<'_>`.
Couple of minor abi handling cleanups
These are extracted out of a wip branch I have to get rid of the `extern "unadjusted"` ABI for anything other than LLVM intrinsics.
Add annotations to the graphviz region graph on region origins
This adds
- `(ex<'e>)` for regions whose origin is existential, with name if one exists,
- `(for<'p>)` for regions whose origin is a placeholder, with name if one exists
For any region whose name we don't know, use `'_`.
This has helped _my_ debugging and it doesn't create too bad clutter, I feel.
The change ~~is~~was ridiculously small, but I turned it into a separate PR so we can bikeshed the format.
The following snippet:
```rust
struct Co<'a>(&'a ());
struct Contra<'a>(fn(&'a ()));
// `exists<'e> forall<'p> 'p: 'e` -> ERROR
fn p_outlives_e(
x: for<'e> fn(for<'p> fn(fn(fn(Contra<'e>, Co<'p>)))),
) -> fn(fn(fn(for<'unify> fn(Contra<'unify>, Co<'unify>)))) {
x
```
Gives this graph:
Remove unneeded `drop_in_place` calls
Might as well pull this out from rust-lang/rust#144561 because this is still used in things like `Vec::truncate` where it'd be nice to allow it be removed if inlined enough to see that the type is `Copy`.
So long as perf says it's ok, at least 🤞
coverage: Extract HIR-related helper code out of the main module
This is a decent chunk of helper code with a narrow external interface (one function returning one struct), making it a good candidate to be extracted out of the main `rustc_mir_transform::coverage` module.
No functional changes.
Add diagnostic explaining STATUS_STACK_BUFFER_OVERRUN not only being used for stack buffer overruns if link.exe exits with that exit code
`STATUS_STACK_BUFFER_OVERRUN` is also used for fast abnormal program termination, e.g. by abort(). Emit a special diagnostic to let people know that this most likely doesn't indicate a stack buffer overrun.
This doesn't look up the crash report in the event log to determine what the fast fail error code is. This is due to the way crashes are logged: When a process crash happens, the system logs an "Application Error" event, which contains the exit code and the process ID, but not the fast fail error code. A second event by Windows Error Reporting does contain that fast fail code, but not the process ID - but that event is not emitted at process exit, but when WER has dealt with it (on my system, it happens roughly two seconds later), so querying the code would have to read the `IntegratorReportId`, wait two seconds or potentially longer for the WER event with the same `ReportID`, and read out the code. (Also, that second event doesn't happen if WER is disabled.)
Fixesrust-lang/rust#100519.
add a scope for `if let` guard temporaries and bindings
This fixes my concern with `if let` guard drop order, namely that the guard's bindings and temporaries were being dropped after their arm's pattern's bindings, instead of before (https://github.com/rust-lang/rust/pull/141295#issuecomment-2968975596). The guard's bindings and temporaries now live in a new scope, which extends until (but not past) the end of the arm, guaranteeing they're dropped before the arm's pattern's bindings.
This only introduces a new scope for match arms with guards. Perf results (https://github.com/rust-lang/rust/pull/143376#issuecomment-3034922617) seemed to indicate there wasn't a significant hit to introduce a new scope on all match arms, but guard patterns (rust-lang/rust#129967) will likely benefit from only adding new scopes when necessary (with some patterns requiring multiple nested scopes).
Tracking issue for `if_let_guard`: rust-lang/rust#51114
Tests are adapted from examples by `@traviscross,` `@est31,` and myself on rust-lang/rust#141295.
Enable f16 and f128 on targets that were fixed in LLVM21
LLVM21 fixed the new float types on a number of targets:
* SystemZ gained f16 support https://github.com/llvm/llvm-project/pull/109164
* Hexagon now uses soft f16 to avoid recursion bugs https://github.com/llvm/llvm-project/pull/130977
* Mips now correctly handles f128 (actually since LLVM20) https://github.com/llvm/llvm-project/pull/117525
* f128 is now correctly aligned when passing the stack on x86 https://github.com/llvm/llvm-project/pull/138092
Thus, enable the types on relevant targets for LLVM > 21.0.0.
NVPTX also gained handling of f128 as a storage type, but it lacks support for basic math operations so is still disabled here.
try-job: dist-i586-gnu-i586-i686-musl
try-job: dist-i686-linux
try-job: dist-i686-msvc
try-job: dist-s390x-linux
try-job: dist-various-1
try-job: dist-various-2
try-job: dist-x86_64-linux
try-job: i686-gnu-1
try-job: i686-gnu-2
try-job: i686-msvc-1
try-job: i686-msvc-2
try-job: test-various
