RFC2229 Add missing edge case
Closes https://github.com/rust-lang/rust/issues/87988
This PR fixes an ICE where a match discriminant is not being read when expected. This ICE was the result of a missing edge case which assumed that if a pattern is of type `PatKind::TupleStruct(..) | PatKind::Path(..) | PatKind::Struct(..) | PatKind::Tuple(..)` then a place could only be a multi variant if the place is of type kind Adt.
Try filtering out non-const impls when we expect const impls
**TL;DR**: Associated types on const impls are now bounded; we now disallow calling a const function with bounds when the specified type param only has a non-const impl.
r? `@oli-obk`
Fix closure migration suggestion when the body is a macro.
Fixes https://github.com/rust-lang/rust/issues/87955
Before:
```
warning: changes to closure capture in Rust 2021 will affect drop order
--> src/main.rs:5:13
|
5 | let _ = || panic!(a.0);
| ^^^^^^^^^^---^
| |
| in Rust 2018, closure captures all of `a`, but in Rust 2021, it only captures `a.0`
6 | }
| - in Rust 2018, `a` would be dropped here, but in Rust 2021, only `a.0` would be dropped here alongside the closure
|
help: add a dummy let to cause `a` to be fully captured
|
20~ ($msg:expr $(,)?) => ({ let _ = &a;
21+ $crate::rt::begin_panic($msg)
22~ }),
|
```
After:
```
warning: changes to closure capture in Rust 2021 will affect drop order
--> src/main.rs:5:13
|
5 | let _ = || panic!(a.0);
| ^^^^^^^^^^---^
| |
| in Rust 2018, closure captures all of `a`, but in Rust 2021, it only captures `a.0`
6 | }
| - in Rust 2018, `a` would be dropped here, but in Rust 2021, only `a.0` would be dropped here alongside the closure
|
help: add a dummy let to cause `a` to be fully captured
|
5 | let _ = || { let _ = &a; panic!(a.0) };
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Implement `black_box` using intrinsic
Introduce `black_box` intrinsic, as suggested in https://github.com/rust-lang/rust/pull/87590#discussion_r680468700.
This is still codegenned as empty inline assembly for LLVM. For MIR interpretation and cranelift it's treated as identity.
cc `@Amanieu` as this is related to inline assembly
cc `@bjorn3` for rustc_codegen_cranelift changes
cc `@RalfJung` as this affects MIRI
r? `@nagisa` I suppose
Improve formatting of closure capture migration suggestion for multi-line closures.
Fixes https://github.com/rust-lang/rust/issues/87952
Before:
```
help: add a dummy let to cause `a` to be fully captured
|
5 ~ let _ = || { let _ = &a;
6 + dbg!(a.0);
7 ~ };
|
```
After:
```
help: add a dummy let to cause `a` to be fully captured
|
5 ~ let _ = || {
6 + let _ = &a;
7 + dbg!(a.0);
8 ~ };
|
```
Implement `black_box` using intrinsic
Introduce `black_box` intrinsic, as suggested in https://github.com/rust-lang/rust/pull/87590#discussion_r680468700.
This is still codegenned as empty inline assembly for LLVM. For MIR interpretation and cranelift it's treated as identity.
cc `@Amanieu` as this is related to inline assembly
cc `@bjorn3` for rustc_codegen_cranelift changes
cc `@RalfJung` as this affects MIRI
r? `@nagisa` I suppose
The new implementation allows some `memcpy`s to be optimized away,
so the uninit value in ui/sanitize/memory.rs is constructed directly
onto the return place. Therefore the sanitizer now says that the
value is allocated by `main` rather than `random`.
Various refactorings of the TAIT infrastructure
Before this PR we used to store the opaque type knowledge outside the `InferCtxt`, so it got recomputed on every opaque type instantiation.
I also removed a feature gate check that makes no sense in the planned lazy TAIT resolution scheme
Each commit passes all tests, so this PR is best reviewed commit by commit.
r? `@spastorino`
typeck: don't suggest inaccessible fields in struct literals and suggest ignoring inaccessible fields in struct patterns
Fixes#87872.
This PR adjusts the missing field diagnostic logic in typeck so that when any of the missing fields in a struct literal or pattern is inaccessible then the error is less confusing, even if some of the missing fields are accessible.
See also #76524.
correctly handle enum variants in `opt_const_param_of`
Fixes#87542
`opt_const_param_of` was returning `None` for args on an enum variant `Enum::Variant::<10>` because we called `generics_of` on the enum variant which has no generics.
r? `@oli-obk`
Simplify typeck/primary_body_of, fix comment to match return signature
Hi, new contributor here! I'm carefully reading through the various modules just to learn. I noticed this function, `primary_body_of`, which has gone through a couple of refactors over time, adding new `Option`s to its returned tuple. Observations:
1. the `fn`'s documentation was not all up to date with the the current return signature.
2. `FnHeader` and `FnDecl` are always both `Some` or `None`. So I figured it might just return a reference to the full `hir::FnSig`, for simplicity and more precise typing. It's a pure refactor.
I'm learning better by working with code than just reading it, so here goes! If you want to avoid pure refactor PRs that don't really fix anything, I can revert the code change to only update the comment instead.
This allows opaque type inference to check for defining uses without having to pass down that def id via function arguments to every method that could possibly cause an opaque type to be compared with a concrete type
Previously each opaque type instantiation would create new inference vars, even for the same opaque type/substs combination. Now there is a global map in InferCtxt that gets filled whenever we encounter an opaque type.
Rollup of 9 pull requests
Successful merges:
- #87561 (thread set_name haiku implementation.)
- #87715 (Add long error explanation for E0625)
- #87727 (explicit_generic_args_with_impl_trait: fix min expected number of generics)
- #87742 (Validate FFI-safety warnings on naked functions)
- #87756 (Add back -Zno-profiler-runtime)
- #87759 (Re-use std::sealed::Sealed in os/linux/process.)
- #87760 (Promote `aarch64-apple-ios-sim` to Tier 2)
- #87770 (permit drop impls with generic constants in where clauses)
- #87780 (alloc: Use intra doc links for the reserve function)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
permit drop impls with generic constants in where clauses
Fixes#79248
`==` is not sufficient to check for equality between unevaluated consts which causes the above issue because the const in `[(); N - 1]:` on the impl and the const in `[(); N - 1]:` on the struct def are not seen as equal. Any predicate that can contain an unevaluated const cant use `==` here as it will cause us to incorrectly emit an error.
I dont know much about chalk but it seems like we ought to be relating the `TypeWellFormedFromEnv` instead of `==` as it contains a `Ty` so I added that too...
r? ``````@lcnr``````
explicit_generic_args_with_impl_trait: fix min expected number of generics
Fixes#87718
The problem was that `synth_type_param_count` was already subtracted from `named_type_param_count`, so this ended up being subtracted again. This caused `expected_min` to overflow, and ultimately resulting in weird and wrong behaviour.
I've also added another test not present in the original issue but caused by the same bug.
rustc: Fill out remaining parts of C-unwind ABI
This commit intends to fill out some of the remaining pieces of the
C-unwind ABI. This has a number of other changes with it though to move
this design space forward a bit. Notably contained within here is:
* On `panic=unwind`, the `extern "C"` ABI is now considered as "may
unwind". This fixes a longstanding soundness issue where if you
`panic!()` in an `extern "C"` function defined in Rust that's actually
UB because the LLVM representation for the function has the `nounwind`
attribute, but then you unwind.
* Whether or not a function unwinds now mainly considers the ABI of the
function instead of first checking the panic strategy. This fixes a
miscompile of `extern "C-unwind"` with `panic=abort` because that ABI
can still unwind.
* The aborting stub for non-unwinding ABIs with `panic=unwind` has been
reimplemented. Previously this was done as a small tweak during MIR
generation, but this has been moved to a separate and dedicated MIR
pass. This new pass will, for appropriate functions and function
calls, insert a `cleanup` landing pad for any function call that may
unwind within a function that is itself not allowed to unwind. Note
that this subtly changes some behavior from before where previously on
an unwind which was caught-to-abort it would run active destructors in
the function, and now it simply immediately aborts the process.
* The `#[unwind]` attribute has been removed and all users in tests and
such are now using `C-unwind` and `#![feature(c_unwind)]`.
I think this is largely the last piece of the RFC to implement.
Unfortunately I believe this is still not stabilizable as-is because
activating the feature gate changes the behavior of the existing `extern
"C"` ABI in a way that has no replacement. My thinking for how to enable
this is that we add support for the `C-unwind` ABI on stable Rust first,
and then after it hits stable we change the behavior of the `C` ABI.
That way anyone straddling stable/beta/nightly can switch to `C-unwind`
safely.
