A few borrowck tweaks to improve 2024 edition migration lints
See first two commits' changes to test outputs. Test coverage in this area is kinda weak, but I think it affects more cases than this (like the craters that will begin to trigger the `tail_expr_drop_order` tests in #134523).
Third commit is a drive-by change that removes a deref hack from `UseSpans` which doesn't really improve diagnostics much.
Add a notion of "some ABIs require certain target features"
I think I finally found the right shape for the data and checks that I recently added in https://github.com/rust-lang/rust/pull/133099, https://github.com/rust-lang/rust/pull/133417, https://github.com/rust-lang/rust/pull/134337: we have a notion of "this ABI requires the following list of target features, and it is incompatible with the following list of target features". Both `-Ctarget-feature` and `#[target_feature]` are updated to ensure we follow the rules of the ABI. This removes all the "toggleability" stuff introduced before, though we do keep the notion of a fully "forbidden" target feature -- this is needed to deal with target features that are actual ABI switches, and hence are needed to even compute the list of required target features.
We always explicitly (un)set all required and in-conflict features, just to avoid potential trouble caused by the default features of whatever the base CPU is. We do this *before* applying `-Ctarget-feature` to maintain backward compatibility; this poses a slight risk of missing some implicit feature dependencies in LLVM but has the advantage of not breaking users that deliberately toggle ABI-relevant target features. They get a warning but the feature does get toggled the way they requested.
For now, our logic supports x86, ARM, and RISC-V (just like the previous logic did). Unsurprisingly, RISC-V is the nicest. ;)
As a side-effect this also (unstably) allows *enabling* `x87` when that is harmless. I used the opportunity to mark SSE2 as required on x86-64, to better match the actual logic in LLVM and because all x86-64 chips do have SSE2. This infrastructure also prepares us for requiring SSE on x86-32 when we want to use that for our ABI (and for float semantics sanity), see https://github.com/rust-lang/rust/issues/133611, but no such change is happening in this PR.
r? `@workingjubilee`
Target: Add mips mti baremetal support
Do the same thing as gcc, which use the vendor `mti` to mark the toolchain as MIPS32r2 default.
We support both big endian and little endian flavor:
mips-mti-none-elf
mipsel-mti-none-elf
Force code generation in assembly generation smoke-tests
In llvm/llvm-project@7b23f413d1 , `.text` started being suppressed from LLVM assembly in cases where it wasn't strictly necessary. Currently, the sample functions in these two tests are frequently decided to be IR-only functions, resulting in no code generation, so LLVM drops the `.text` directive.
Adding `#[no_mangle]` forces these tests back to their original intent - assembly code is generated, and so a `.text` directive is generated as well.
`@rustbot` label: +llvm-main
r? `@workingjubilee`
I'll attach a buildbot link once it finishes consuming this PR
turn rustc_box into an intrinsic
I am not entirely sure why this was made a special magic attribute, but an intrinsic seems like a more natural way to add magic expressions to the language.
rustc_intrinsic: support functions without body
We synthesize a HIR body `loop {}` but such bodyless intrinsics.
Most of the diff is due to turning `ItemKind::Fn` into a brace (named-field) enum variant, because it carries a `bool`-typed field now. This is to remember whether the function has a body. MIR building panics to avoid ever translating the fake `loop {}` body, and the intrinsic logic uses the lack of a body to implicitly mark that intrinsic as must-be-overridden.
I first tried actually having no body rather than generating the fake body, but there's a *lot* of code that assumes that all function items have HIR and MIR, so this didn't work very well. Then I noticed that even `rustc_intrinsic_must_be_overridden` intrinsics have MIR generated (they are filled with an `Unreachable` terminator) so I guess I am not the first to discover this. ;)
r? `@oli-obk`
Update carrying_mul_add test to tolerate `nuw`
LLVM 20 adds nuw to GEP operations in this code, tolerate them.
`@rustbot` label: +llvm-main
r? `@durin42`
const-in-pattern: test that the PartialEq impl does not need to be const
Fixes https://github.com/rust-lang/rust/issues/119398 by adding a test.
`@compiler-errors` is there some place in the code where we could add a comment saying "as a backcompat hack, here we only require `PartialEq` and not `const PartialEq`"?
r? `@compiler-errors`
Project to `TyKind::Error` when there are unconstrained non-lifetime (ty/const) impl params
It splits the `enforce_impl_params_are_constrained` function into lifetime/non-lifetime, and queryfies the latter. We can then use the result of the latter query (`Result<(), ErrorGuaranteed>`) to intercept projection and constrain the projected type to `TyKind::Error`, which ensures that we leak no ty or const vars to places that don't expect them, like `normalize_erasing_regions`.
The reason we split `enforce_impl_params_are_constrained` into two parts is because we only error for *lifetimes* if the lifetime ends up showing up in any of the associated types of the impl (e.g. we allow `impl<'a> Foo { type Assoc = (); }`). However, in order to compute the `type_of` query for the anonymous associated type of an RPITIT, we need to do trait solving (in `query collect_return_position_impl_trait_in_trait_tys`). That would induce cycles. Luckily, it turns out for lifetimes we don't even care about if they're unconstrained, since they're erased in all contexts that we are trying to fix ICEs. So it's sufficient to keep this check separated out of the query.
I think this is a bit less invasive of an approach compared to #127973. The major difference between this PR and that PR is that we queryify the check instead of merging it into the `explicit_predicates_of` query, and we use the result to taint just projection goals, rather than trait goals too. This doesn't require a lot of new tracking in `ItemCtxt` and `GenericPredicates`, and it also seems to not require any other changes to typeck like that PR did.
Fixes#123141Fixes#125874Fixes#126942Fixes#127804Fixes#130967
r? oli-obk
In llvm/llvm-project@7b23f413d1 , `.text`
started being suppressed from LLVM assembly in cases where it wasn't
strictly necessary. Currently, the sample functions in these two tests
are frequently decided to be IR-only functions, resulting in no code
generation, so LLVM drops the `.text` directive.
Adding `#[no_mangle]` forces these tests back to their original intent -
assembly code is generated, and so a `.text` directive is generated as
well.
Improve infer (`_`) suggestions in `const`s and `static`s
Fixes https://github.com/rust-lang/rust/issues/135010.
This PR does a few things to (imo) greatly improve the error message when users write something like `static FOO: [i32; _] = [1, 2, 3]`.
Firstly, it adapts the recovery code for when we encounter `_` in a const/static to work a bit more like `fn foo() -> _`, and removes the somewhat redundant query `diagnostic_only_typeck`.
Secondly, it changes the lowering for `[T; _]` to always lower under the `feature(generic_arg_infer)` logic to `ConstArgKind::Infer`. We still issue the feature error, so it's not doing anything *observable* on the good path, but it does mean that we no longer erroneously interpret `[T; _]`'s array length as a `_` **wildcard expression** (à la destructuring assignment, like `(_, y) = expr`).
Lastly it makes the suggestions verbose and fixes (well, suppresses) a bug with stashing and suggestions.
r? oli-obk
rustdoc: treat `allowed_through_unstable_modules` as deprecation
This ensures `std::intrinsics::transmute` is deemphasized in the search engine and other UI, by cleaning it into a deprecation without propagating it through reexports when the parent module is stable.
Fixes#131676
Related to #135003
r? ``@GuillaumeGomez``
``@RalfJung`` ``@workingjubilee``
Pass objcopy args for stripping on OSX
When `-Cstrip` was changed in #131405 to use the bundled rust-objcopy instead of /usr/bin/strip on OSX, strip-like arguments were preserved.
But strip and objcopy are, while being the same binary, different, they have different defaults depending on which binary they are. Notably, strip strips everything by default, and objcopy doesn't strip anything by default.
Additionally, `-S` actually means `--strip-all`, so debuginfo stripped everything and symbols didn't strip anything.
We now correctly pass `--strip-debug` and `--strip-all`.
fixes#135028
try-job: aarch64-apple
try-job: dist-aarch64-apple
Do the same thing as gcc, which use the vendor `mti` to mark
the toolchain as MIPS32r2 default.
We support both big endian and little endian flavor:
mips-mti-none-elf
mipsel-mti-none-elf
taint fcx on selection errors during unsizing
With `feature(dyn_compatible_for_dispatch)` we only check for dyn-compatibility by checking the `T: Unsize<dyn Trait>` predicate during the unsizing coercions checks. If the predicate doesn't hold, we emit an error, but pretend the coercion succeeded to prevent further errors. To prevent const eval from attempting to actually perform this coercion, we need to taint the fcx after reporting the trait errors in the coercion check.
fixes https://github.com/rust-lang/rust/issues/135021
fixes https://github.com/rust-lang/rust/issues/130521
Move some things to `std::sync::poison` and reexport them in `std::sync`
Tracking issue: #134646
r? `@tgross35`
I've used `sync_poison_mod` feature flag instead, because `sync_poison` had already been used back in 1.2.
try-job: x86_64-msvc
Try to write the panic message with a single `write_all` call
This writes the panic message to a buffer before writing to stderr. This allows it to be printed with a single `write_all` call, preventing it from being interleaved with other outputs. It also adds newlines before and after the message ensuring that only the panic message will have its own lines.
Before:
```
thread 'thread 'thread 'thread 'thread '<unnamed>thread 'thread 'thread 'thread '<unnamed><unnamed>thread '<unnamed>' panicked at ' panicked at <unnamed><unnamed><unnamed><unnamed><unnamed>' panicked at <unnamed>' panicked at src\heap.rssrc\heap.rs'
panicked at ' panicked at ' panicked at ' panicked at ' panicked at src\heap.rs' panicked at src\heap.rs::src\heap.rssrc\heap.rssrc\heap.rssrc\heap.rssrc\heap.rs:src\heap.rs:455455:::::455:455::455455455455455:455:99:::::9:9:
:
999:
999:
assertion failed: size <= (*queue).block_size:
:
assertion failed: size <= (*queue).block_size:
assertion failed: size <= (*queue).block_size:
:
:
assertion failed: size <= (*queue).block_sizeassertion failed: size <= (*queue).block_sizeassertion failed: size <= (*queue).block_size
assertion failed: size <= (*queue).block_size
assertion failed: size <= (*queue).block_sizeassertion failed: size <= (*queue).block_sizeerror: process didn't exit successfully: `target\debug\direct_test.exe` (exit code: 0xc0000409, STATUS_STACK_BUFFER_OVERRUN)
```
After:
```
thread '<unnamed>' panicked at src\heap.rs:455:9:
assertion failed: size <= (*queue).block_size
thread '<unnamed>' panicked at src\heap.rs:455:9:
assertion failed: size <= (*queue).block_size
thread '<unnamed>' panicked at src\heap.rs:455:9:
assertion failed: size <= (*queue).block_size
error: process didn't exit successfully: `target\debug\direct_test.exe` (exit code: 0xc0000409, STATUS_STACK_BUFFER_OVERRUN)
```
---
try-jobs: x86_64-gnu-llvm-18
When `-Cstrip` was changed to use the bundled rust-objcopy instead of
/usr/bin/strip on OSX, strip-like arguments were preserved.
But strip and objcopy are, while being the same binary, different, they
have different defaults depending on which binary they are.
Notably, strip strips everything by default, and objcopy doesn't strip
anything by default.
Additionally, `-S` actually means `--strip-all`, so debuginfo stripped
everything and symbols didn't strip anything.
We now correctly pass `--strip-debug` and `--strip-all`.
This ensures `std::intrinsics::transmute` is deemphasized
in the search engine and other UI, by cleaning it into a deprecation
without propagating it through reexports when the parent module
is stable.
Provide structured suggestion for `impl Default` of type where all fields have defaults
```
error: `Default` impl doesn't use the declared default field values
--> $DIR/manual-default-impl-could-be-derived.rs:28:1
|
LL | / impl Default for B {
LL | | fn default() -> Self {
LL | | B {
LL | | x: s(),
| | --- this field has a default value
LL | | y: 0,
| | - this field has a default value
... |
LL | | }
| |_^
|
help: to avoid divergence in behavior between `Struct { .. }` and `<Struct as Default>::default()`, derive the `Default`
|
LL ~ #[derive(Default)] struct B {
|
```
Note that above the structured suggestion also includes completely removing the manual `impl`, but the rendering doesn't.
