On resolve error of `[rest..]`, suggest `[rest @ ..]`
When writing a pattern to collect multiple entries of a slice in a single binding, it is easy to misremember or typo the appropriate syntax to do so, instead writing the experimental `X..` pattern syntax. When we encounter a resolve error because `X` isn't available, we suggest `X @ ..` as an alternative.
```
error[E0425]: cannot find value `rest` in this scope
--> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:3:13
|
LL | [1, rest..] => println!("{rest:?}"),
| ^^^^ not found in this scope
|
help: if you meant to collect the rest of the slice in `rest`, use the at operator
|
LL | [1, rest @ ..] => println!("{rest:?}"),
| +
```
Fix#88404.
Misc changes to StableMIR required to Kani use case.
First, I wanted to say that I can split this review into multiple if it makes reviewing easier. I bundled them up, since I've been testing them together (See https://github.com/rust-lang/project-stable-mir/pull/51 for the set of more thorough checks).
So far, this review includes 3 commits:
1. Add more APIs and fix `Instance::body`
- Add more APIs to retrieve information about types.
- Add a few more instance resolution options. For the drop shim, we return None if the drop body is empty. Not sure it will be enough.
- Make `Instance::body()` return an Option<Body>, since not every instance might have an available body. For example, foreign instances, virtual instances, dependencies.
2. Fix a bug on MIRVisitor
- We were not iterating over all local variables due to a typo.
3. Add more SMIR internal impl and callback return value
- In cases like Kani, we will invoke the rustc_internal run command directly for now. It would be handly to be able to have a callback that can return a value.
- We also need extra methods to convert stable constructs into internal ones, so we can break down the transition into finer grain commits.
- For the internal implementation of Region, we're always returning `ReErased` for now.
document ABI compatibility
I don't think we have any central place where we document our ABI compatibility rules, so let's create one. The `fn()` pointer type seems like a good place since ABI questions can only become relevant when invoking a function through a function pointer.
This will likely need T-lang FCP.
When writing a pattern to collect multiple entries of a slice in a
single binding, it is easy to misremember or typo the appropriate syntax
to do so, instead writing the experimental `X..` pattern syntax. When we
encounter a resolve error because `X` isn't available, we suggest
`X @ ..` as an alternative.
```
error[E0425]: cannot find value `rest` in this scope
--> $DIR/range-pattern-meant-to-be-slice-rest-pattern.rs:3:13
|
LL | [1, rest..] => println!("{rest:?}"),
| ^^^^ not found in this scope
|
help: if you meant to collect the rest of the slice in `rest`, use the at operator
|
LL | [1, rest @ ..] => println!("{rest:?}"),
| +
```
Fix#88404.
Better handle type errors involving `Self` literals
When encountering a type error involving a `Self` literal, point at the self type of the enclosing `impl` and suggest using the actual type name instead.
```
error[E0308]: mismatched types
--> $DIR/struct-path-self-type-mismatch.rs:13:9
|
LL | impl<T> Foo<T> {
| - ------ this is the type of the `Self` literal
| |
| found type parameter
LL | fn new<U>(u: U) -> Foo<U> {
| - ------ expected `Foo<U>` because of return type
| |
| expected type parameter
LL | / Self {
LL | |
LL | | inner: u
LL | |
LL | | }
| |_________^ expected `Foo<U>`, found `Foo<T>`
|
= note: expected struct `Foo<U>`
found struct `Foo<T>`
= note: a type parameter was expected, but a different one was found; you might be missing a type parameter or trait bound
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
help: use the type name directly
|
LL | Foo::<U> {
| ~~~~~~~~
```
Fix#76086.
Add more APIs to retrieve information about types, and add more instance
resolution options.
Make `Instance::body()` return an Option<Body>, since not every instance
might have an available body. For example, foreign instances, virtual
instances, dependencies.
When encountering a type error caused by the use of `Self`, suggest
using the actual type name instead.
```
error[E0308]: mismatched types
--> $DIR/struct-path-self-type-mismatch.rs:13:9
|
LL | impl<T> Foo<T> {
| - ------ this is the type of the `Self` literal
| |
| found type parameter
LL | fn new<U>(u: U) -> Foo<U> {
| - ------ expected `Foo<U>` because of return type
| |
| expected type parameter
LL | / Self {
LL | |
LL | | inner: u
LL | |
LL | | }
| |_________^ expected `Foo<U>`, found `Foo<T>`
|
= note: expected struct `Foo<U>`
found struct `Foo<T>`
= note: a type parameter was expected, but a different one was found; you might be missing a type parameter or trait bound
= note: for more information, visit https://doc.rust-lang.org/book/ch10-02-traits.html#traits-as-parameters
help: use the type name directly
|
LL | Foo::<U> {
| ~~~~~~~~
```
Fix#76086.
Fix depth check in ProofTreeVisitor.
The hack to cutoff overflows and cycles in the new trait solver was incorrect. We want to inspect everything with depth [0..10].
This fix exposed a previously unseen bug, which caused the compiler to ICE when invoking `trait_ref` on a non-assoc type projection. I simply added the guard in the `AmbiguityCausesVisitor`, and updated the expected output for the `auto-trait-coherence` test which now includes the extra note:
```text
|
= note: upstream crates may add a new impl of trait `std::marker::Send` for type `OpaqueType` in future versions
```
r? `@lcnr`
Add -Z llvm_module_flag
Allow adding values to the `!llvm.module.flags` metadata for a generated module. The syntax is
`-Z llvm_module_flag=<name>:<type>:<value>:<behavior>`
Currently only u32 values are supported but the type is required to be specified for forward compatibility. The `behavior` element must match one of the named LLVM metadata behaviors.viors.
This flag is expected to be perma-unstable.
finish `RegionKind` renaming
second step of https://github.com/rust-lang/types-team/issues/95
continues the work from #117876. While working on this and I encountered a bunch of further cleanup which I'll either open a tracking issue for or will do in a separate PR:
- rewrite the `RegionKind` docs, they still talk about `ReEmpty` and are generally out of date
- rename `DescriptionCtx` to `DescriptionCtxt`
- what is `CheckRegions::Bound`?
- `collect_late_bound_regions` et al
- `erase_late_bound_regions` -> `instantiate_bound_regions_with_erased`?
- `EraseEarlyRegions` visitor should be removed, feels duplicate
r? `@BoxyUwU`
Don't expect a rcvr in `print_disambiguation_help`
We don't necessarily have a receiver when we are both accidentally using the `.` operator *AND* we have more than one ambiguous method candidate.
Fixes#117728
Add richer structure for Stable MIR Projections
Resolves https://github.com/rust-lang/project-stable-mir/issues/49.
Projections in Stable MIR are currently just strings. This PR replaces that representation with a richer structure, namely projections become vectors of `ProjectionElem`s, just as in MIR. The `ProjectionElem` enum is heavily based off of the MIR `ProjectionElem`.
This PR is a draft since there are several outstanding issues to resolve, including:
- How should `UserTypeProjection`s be represented in Stable MIR? In MIR, the projections are just a vector of `ProjectionElem<(),()>`, meaning `ProjectionElem`s that don't have Local or Type arguments (for `Index`, `Field`, etc. objects). Should `UserTypeProjection`s be represented this way in Stable MIR as well? Or is there a more user-friendly representation that wouldn't drag along all the `ProjectionElem` variants that presumably can't appear?
- What is the expected behavior of a `Place`'s `ty` function? Should it resolve down the chain of projections so that something like `*_1.f` would return the type referenced by field `f`?
- Tests should be added for `UserTypeProjection`
Build pre-coroutine-transform coroutine body on error
I was accidentally building the post-transform coroutine body, rather than the pre-transform coroutine body. There's no pinning expected here yet, and the return type isn't yet transformed into `CoroutineState`.
Fixes#117670
Custom MIR: Support cleanup blocks
Cleanup blocks are declared with `bb (cleanup) = { ... }`.
`Call` and `Drop` terminators take an additional argument describing the unwind action, which is one of the following:
* `UnwindContinue()`
* `UnwindUnreachable()`
* `UnwindTerminate(reason)`, where reason is `ReasonAbi` or `ReasonInCleanup`
* `UnwindCleanup(block)`
Also support unwind resume and unwind terminate terminators:
* `UnwindResume()`
* `UnwindTerminate(reason)`
Cleanup blocks are declared with `bb (cleanup) = { ... }`.
`Call` and `Drop` terminators take an additional argument describing the
unwind action, which is one of the following:
* `UnwindContinue()`
* `UnwindUnreachable()`
* `UnwindTerminate(reason)`, where reason is `ReasonAbi` or `ReasonInCleanup`
* `UnwindCleanup(block)`
Also support unwind resume and unwind terminate terminators:
* `UnwindResume()`
* `UnwindTerminate(reason)`
Always point at index span on index obligation failure
Use more targetted span for index obligation failures by rewriting the obligation cause span.
CC #66023
tests: update check for inferred nneg on zext
This was broken by upstream
llvm/llvm-project@dc6d077396. It's easy enough to use a regex match to support both, so we do that.
r? `@nikic`
`@rustbot` label: +llvm-main
Compute layout with spans for better cycle errors in coroutines
Split out from #117703, this PR at least gives us a nicer span to point at when we hit a cycle error in coroutine layout cycles.
This was broken by upstream
llvm/llvm-project@dc6d077396. It's easy
enough to use a regex match to support both, so we do that.
r? @nikic
@rustbot label: +llvm-main
`ReLateBound` -> `ReBound`
first step of https://github.com/rust-lang/types-team/issues/95
already fairly large xx
there's some future work here I intentionally did not contribute as part of this PR, from my notes:
- `DescriptionCtx` to `DescriptionCtxt`
- what is `CheckRegions::Bound`?
- `collect_late_bound_regions` et al
- `erase_late_bound_regions` -> `instantiate_bound_regions_with_erased`?
- `EraseEarlyRegions` should be removed, feels duplicate
r? `@BoxyUwU`
coverage: Avoid creating malformed macro name spans
This is a workaround for #117788. It detects a particular scenario where we would create malformed coverage spans that might cause `llvm-cov` to immediately exit with an error, preventing the user from processing coverage reports.
The patch has been kept as simple as possible so that it's trivial to backport to beta (or stable) if desired.
---
The `maybe_push_macro_name_span` method is trying to detect macro invocations, so that it can split a span into two parts just after the `!` of the invocation.
Under some circumstances (probably involving nested macros), it gets confused and produces a span that is larger than the original span, and possibly extends outside its enclosing function and even into an adjacent file.
In extreme cases, that can result in malformed coverage mappings that cause `llvm-cov` to fail. For now, we at least want to detect these egregious cases and avoid them, so that coverage reports can still be produced.
Without the workaround applied, this test will produce malformed mappings that
cause `llvm-cov` to fail.
(And if it does emit well-formed mappings, they should be obviously incorrect.)
