| Age | Commit message (Collapse) | Author | Lines |
|---|
|
Skip cleanups on unsupported targets
This commit is an update to the `AbortUnwindingCalls` MIR pass in the compiler. Specifically a new boolean is added for "can this target possibly unwind" and if that's `false` then terminators are all adjusted to be unreachable/not present. The end result is that this fixes rust-lang/rust#140293 for wasm targets.
The motivation for this PR is that currently on WebAssembly targets the usage of the `C-unwind` ABI can lead LLVM to either (a) emit exception-handling instructions or (b) hit a LLVM-ICE-style codegen error. WebAssembly as a base instruction set does not support unwinding at all, and a later proposal to WebAssembly, the exception-handling proposal, was what enabled this. This means that the current intent of WebAssembly targets is that they maintain the baseline of "don't emit exception-handling instructions unless enabled". The commit here is intended to restore this behavior by skipping these instructions even when `C-unwind` is present.
Exception-handling is a relatively tricky and also murky topic in WebAssembly, however. There are two sets of instructions LLVM can emit for WebAssembly exceptions, Rust's Emscripten target supports exceptions, WASI targets do not, the LLVM flags to enable this are not always obvious, and additionally this all touches on "changing exception-handling behavior should be a target-level concern, not a feature". Effectively WebAssembly's exception-handling integration into Rust is not finalized at this time. The best idea at this time is that a parallel set of targets will eventually be added which support exceptions, but it's not clear if/when to do this. In the meantime the goal is to keep existing targets working while still enabling experimentation with exception-handling with `-Zbuild-std` and various permutations of LLVM flags.
To that extent this commit does not blanket disable these landing pads and cleanup routines for WebAssembly but instead checks to see if panic=unwind is enabled or if `+exception-handling` is enabled. Tests are updated here as well to account for this where, by default, using a `C-unwind` ABI won't affect Rust codegen at all. If `+exception-handling` is enabled, however, then Rust codegen will look like native platforms where exceptions are caught and the program aborts. More-or-less I've done my best to keep exceptions working on wasm where it's possible to have them work, but turned them off where they're not supposed to be emitted.
Closes rust-lang/rust#140293
|
|
Introduce CoerceShared lang item and trait, and basic Reborrow tests
Part of rust-lang/rust#145612: This introduces the `CoerceShared` trait which is the `Reborrow` equivalent of a `&mut T` -> `&T` coercion. The trait has a `Target` GAT which makes this (currently) unique in the `core/src/marker.rs`; I'm not sure if this can be considered problematic. Maybe this is not the way such things should be done at the marker trait level? Or maybe it is fine.
Improtantly, this PR introduces a battery of basic `Reborrow` and `CoerceShared` tests. These test the very basics of the feature; custom marker types intended to have exclusive semantics (`Custom<'a>(PhantomData<&'a mut ()>)`), custom exclusive reference wrappers, and standard library exclusive reference wrappers (`Pin<&mut T>` and `Option<&mut T>`). None of these of course work since the implementation for `Reborrow` and `CoerceShared` is entirely missing, but this is the first step towards making these work.
Future PRs will introduce more tests, such as "recursive" reborrowing (ie. reborrowing structs that contain multiple reborrowable fields) and checks around the lifetime semantics of reborrowing ie. that a reborrow produces a new type with the same lifetime as the original.
|
|
|
|
|
|
|
|
|
|
|
|
Add an attribute to check the number of lanes in a SIMD vector after monomorphization
Allows std::simd to drop the `LaneCount<N>: SupportedLaneCount` trait and maintain good error messages.
Also, extends rust-lang/rust#145967 by including spans in layout errors for all ADTs.
r? ``@RalfJung``
cc ``@workingjubilee`` ``@programmerjake``
|
|
monomorphization
Unify zero-length and oversized SIMD errors
|
|
Add panic=immediate-abort
MCP: https://github.com/rust-lang/compiler-team/issues/909
This adds a new panic strategy, `-Cpanic=immediate-abort`. This panic strategy essentially just codifies use of `-Zbuild-std-features=panic_immediate_abort`. This PR is intended to just set up infrastructure, and while it will change how the compiler is invoked for users of the feature, there should be no other impacts.
In many parts of the compiler, `PanicStrategy::ImmediateAbort` behaves just like `PanicStrategy::Abort`, because actually most parts of the compiler just mean to ask "can this unwind?" so I've added a helper function so we can say `sess.panic_strategy().unwinds()`.
The panic and unwind strategies have some level of compatibility, which mostly means that we can pre-compile the sysroot with unwinding panics then the sysroot can be linked with aborting panics later. The immediate-abort strategy is all-or-nothing, enforced by `compiler/rustc_metadata/src/dependency_format.rs` and this is tested for in `tests/ui/panic-runtime/`. We could _technically_ be more compatible with the other panic strategies, but immediately-aborting panics primarily exist for users who want to eliminate all the code size responsible for the panic runtime. I'm open to other use cases if people want to present them, but not right now. This PR is already large.
`-Cpanic=immediate-abort` sets both `cfg(panic = "immediate-abort")` _and_ `cfg(panic = "abort")`. bjorn3 pointed out that people may be checking for the abort cfg to ask if panics will unwind, and also the sysroot feature this is replacing used to require `-Cpanic=abort` so this seems like a good back-compat step. At least for the moment. Unclear if this is a good idea indefinitely. I can imagine this being confusing.
The changes to the standard library attributes are purely mechanical. Apart from that, I removed an `unsafe` we haven't needed for a while since the `abort` intrinsic became safe, and I've added a helpful diagnostic for people trying to use the old feature.
To test that `-Cpanic=immediate-abort` conflicts with other panic strategies, I've beefed up the core-stubs infrastructure a bit. There is now a separate attribute to set flags on it.
I've added a test that this produces the desired codegen, called `tests/run-make-cargo/panic-immediate-abort-codegen/` and also a separate run-make-cargo test that checks that we can build a binary.
|
|
|
|
|
|
|
|
Remove Rvalue::Len again.
Now that we have `RawPtrKind::FakeForPtrMetadata`, we can reimplement `Rvalue::Len` using `PtrMetadata(&raw const (fake) place)`.
r? ``@scottmcm``
|
|
|
|
|
|
|
|
This commit is an update to the `AbortUnwindingCalls` MIR pass in the
compiler. Specifically a new boolean is added for "can this target
possibly unwind" and if that's `false` then terminators are all adjusted
to be unreachable/not present. The end result is that this fixes 140293
for wasm targets.
The motivation for this PR is that currently on WebAssembly targets the
usage of the `C-unwind` ABI can lead LLVM to either (a) emit
exception-handling instructions or (b) hit a LLVM-ICE-style codegen
error. WebAssembly as a base instruction set does not support unwinding
at all, and a later proposal to WebAssembly, the exception-handling
proposal, was what enabled this. This means that the current intent of
WebAssembly targets is that they maintain the baseline of "don't emit
exception-handling instructions unless enabled". The commit here is
intended to restore this behavior by skipping these instructions even
when `C-unwind` is present.
Exception-handling is a relatively tricky and also murky topic in
WebAssembly, however. There are two sets of instructions LLVM can emit
for WebAssembly exceptions, Rust's Emscripten target supports
exceptions, WASI targets do not, the LLVM flags to enable this are not
always obvious, and additionally this all touches on "changing
exception-handling behavior should be a target-level concern, not a
feature". Effectively WebAssembly's exception-handling integration into
Rust is not finalized at this time. The best idea at this time is that a
parallel set of targets will eventually be added which support
exceptions, but it's not clear if/when to do this. In the meantime the
goal is to keep existing targets working while still enabling
experimentation with exception-handling with `-Zbuild-std` and various
permutations of LLVM flags.
To that extent this commit does not blanket disable these landing pads
and cleanup routines for WebAssembly but instead checks to see if
panic=unwind is enabled or if `+exception-handling` is enabled. Tests
are updated here as well to account for this where, by default, using a
`C-unwind` ABI won't affect Rust codegen at all. If
`+exception-handling` is enabled, however, then Rust codegen will look
like native platforms where exceptions are caught and the program aborts.
More-or-less I've done my best to keep exceptions working on wasm where
it's possible to have them work, but turned them off where they're not
supposed to be emitted.
|
|
report duplicate symbols added by the driver
The panic message did not mention what symbols were duplicates, which made the panic hard to debug. This came up in [#t-compiler/help > Easiest way to find offending duplicate symbols](https://rust-lang.zulipchat.com/#narrow/channel/182449-t-compiler.2Fhelp/topic/Easiest.20way.20to.20find.20offending.20duplicate.20symbols/with/538295740).
This behavior was introduced in https://github.com/rust-lang/rust/pull/138682.
r? ```@fee1-dead```
|
|
Minor symbol comment fixes.
- The empty symbol is no longer a keyword.
- I don't think any of the special reserved identifiers are used for error recovery.
r? ```@petrochenkov```
|
|
r=jdonszelmann,ralfjung,traviscross
Implement `#[rustc_align_static(N)]` on `static`s
Tracking issue: https://github.com/rust-lang/rust/issues/146177
```rust
#![feature(static_align)]
#[rustc_align_static(64)]
static SO_ALIGNED: u64 = 0;
```
We need a different attribute than `rustc_align` because unstable attributes are tied to their feature (we can't have two unstable features use the same unstable attribute). Otherwise this uses all of the same infrastructure as `#[rustc_align]`.
r? `@traviscross`
|
|
inclusive `Range`s: change `end` to `last`
Tracking issue: rust-lang/rust#125687
ACP: rust-lang/libs-team#511
|
|
We need a different attribute than `rustc_align` because unstable attributes are
tied to their feature (we can't have two unstable features use the same
unstable attribute). Otherwise this uses all of the same infrastructure
as `#[rustc_align]`.
|
|
|
|
|
|
- The empty symbol is no longer a keyword.
- I don't think any of the special reserved identifiers are used for
error recovery.
|
|
Implement Integer funnel shifts
Tracking issue: rust-lang/rust#145686
ACP: https://github.com/rust-lang/libs-team/issues/642
This implements funnel shifts on primitive integer types. Implements this for cg_llvm, with a fallback impl for everything else
Thanks `@folkertdev` for the fixes and tests
cc `@rust-lang/libs-api`
|
|
Allow `inline(always)` with a target feature behind a unstable feature `target_feature_inline_always`.
Rather than adding the inline always attribute to the function definition, we add it to the callsite. We can then check that the target features match and that the call would be safe to inline. If the function isn't inlined due to a mismatch, we emit a warning informing the user that the function can't be inlined due to the target feature mismatch.
See tracking issue rust-lang/rust#145574
|
|
- Add a fallback implementation for the intrinsics
- Add LLVM backend support for funnel shifts
Co-Authored-By: folkertdev <folkert@folkertdev.nl>
|
|
Add new `doc(attribute = "...")` attribute
Fixes rust-lang/rust#141123.
The implementation and purpose of this new `#[doc(attribute = "...")]` attribute is very close to `#[doc(keyword = "...")]`. Which means that luckily for us, most of the code needed was already in place and `@Noratrieb` nicely wrote a first draft that helped me implement this new attribute very fast.
Now with all this said, there is one thing I didn't do yet: adding a `rustdoc-js-std` test. I added GUI tests with search results for attributes so should be fine but I still plan on adding one for it once documentation for builtin attributes will be written into the core/std libs.
You can test it [here](https://rustdoc.crud.net/imperio/doc-attribute-attribute/foo/index.html).
cc `@Noratrieb` `@Veykril`
|
|
|
|
|
|
Co-authored-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
|
|
This commit implements more conformant, more comprehensive RISC-V ELF
flags handling when generating certain object files directly from rustc.
* Use "zca" instead of "c"
The "Zca" extension (a subset of "C") is the minimal configuration
for compressed instructions to set `EF_RISCV_RVC` flag.
* Set TSO flag from "ztso"
The "Ztso" extension denotes that the program depends on the RVTSO
(Total Store Ordering) memory consistency model, which is stronger
than the standard RVWMO (Weak Memory Ordering) consistency model and
on ELF targets, we need to set `EF_RISCV_TSO` flag.
|
|
Experiment: Reborrow trait
Tracking issue: rust-lang/rust#145612
Starting off really small here: just introduce the unstable feature and the feature gate, and one of the two traits that the Reborrow experiment deals with.
### Cliff-notes explanation
The `Reborrow` trait is conceptually a close cousin of `Copy` with the exception that it disables the source (`self`) for the lifetime of the target / result of the reborrow action. It can be viewed as a method of `fn reborrow(self: Self<'a>) -> Self<'a>` with the compiler adding tracking of the resulting `Self<'a>` (or any value derived from it that retains the `'a` lifetime) to keep the `self` disabled for reads and writes.
No method is planned to be surfaced to the user, however, as reborrowing cannot be seen in code (except for method calls [`a.foo()` reborrows `a`] and explicit reborrows [`&*a`]) and thus triggering user-code in it could be viewed as "spooky action at a distance". Furthermore, the added compiler tracking cannot be seen on the method itself, violating the Golden Rule. Note that the userland "reborrow" method is not True Reborrowing, but rather a form of a "Fancy Deref":
```rust
fn reborrow(&'short self: Self<'long>) -> Self<'short>;
```
The lifetime shortening is the issue here: a reborrowed `Self` or any value derived from it is bound to the method that called `reborrow`, since `&'short` is effectively a local variable. True Reborrowing does not shorten the lifetime of the result.
To avoid having to introduce new kinds of references, new kinds of lifetime annotations, or a blessed trait method, no method will be introduced at all. Instead, the `Reborrow` trait is intended to be a derived trait that effectively reborrows each field individually; `Copy` fields end up just copying, while fields that themselves `Reborrow` get disabled in the source, usually leading to the source itself being disabled (some differences may appear with structs that contain multiple reborrowable fields). The goal of the experiment is to determine how the actual implementation here will shape out, and what the "bottom case" for the recursive / deriving `Reborrow` is.
`Reborrow` has a friend trait, `CoerceShared`, which is equivalent to a `&'a mut T -> &'a T` conversion. This is needed as a different trait and different operation due to the different semantics it enforces on the source: a `CoerceShared` operation only disables the source for writes / exclusive access for the lifetime of the result. That trait is not yet introduced in this PR, though there is no particular reason why it could not be introduced.
|
|
Add an experimental unsafe(force_target_feature) attribute.
This uses the feature gate for https://github.com/rust-lang/rust/issues/143352, but is described in https://github.com/rust-lang/rfcs/pull/3820 which is strongly tied to the experiment.
|
|
|
|
|
|
This uses the feature gate for
https://github.com/rust-lang/rust/issues/143352, but is described in
https://github.com/rust-lang/rfcs/pull/3820 which is strongly tied to
the experiment.
|
|
|
|
Pass `alloc-variant-zeroed` to LLVM
Makes use of https://github.com/llvm/llvm-project/pull/138299 (once we pull in a version of LLVM with this attribute). ~~Unfortunately also requires https://github.com/llvm/llvm-project/pull/149336 to work.~~
Closes rust-lang/rust#104847
|
|
|
|
Remove the `#[no_sanitize]` attribute in favor of `#[sanitize(xyz = "on|off")]`
This came up during the sanitizer stabilization (rust-lang/rust#123617). Instead of a `#[no_sanitize(xyz)]` attribute, we would like to have a `#[sanitize(xyz = "on|off")]` attribute, which is more powerful and allows to be extended in the future (instead
of just focusing on turning sanitizers off). The implementation is done according to what was [discussed on Zulip](https://rust-lang.zulipchat.com/#narrow/channel/343119-project-exploit-mitigations/topic/Stabilize.20the.20.60no_sanitize.60.20attribute/with/495377292)).
The new attribute also works on modules, traits and impl items and thus enables usage as the following:
```rust
#[sanitize(address = "off")]
mod foo {
fn unsanitized(..) {}
#[sanitize(address = "on")]
fn sanitized(..) {}
}
trait MyTrait {
#[sanitize(address = "off")]
fn unsanitized_default(..) {}
}
#[sanitize(thread = "off")]
impl MyTrait for () {
...
}
```
r? ```@rcvalle```
|
|
This removes the #[no_sanitize] attribute, which was behind an unstable
feature named no_sanitize. Instead, we introduce the sanitize attribute
which is more powerful and allows to be extended in the future (instead
of just focusing on turning sanitizers off).
This also makes sanitize(kernel_address = ..) attribute work with
-Zsanitize=address
To do it the same as how clang disables address sanitizer, we now
disable ASAN on sanitize(kernel_address = "off") and KASAN on
sanitize(address = "off").
The same was added to clang in https://reviews.llvm.org/D44981.
|
|
Implement declarative (`macro_rules!`) derive macros (RFC 3698)
This is a draft for review, and should not be merged yet.
This is layered atop https://github.com/rust-lang/rust/pull/145153 , and has
only two additional commits atop that. The first handles parsing and provides a
test for various parse errors. The second implements expansion and handles
application.
This implements RFC 3698, "Declarative (`macro_rules!`) derive macros".
Tracking issue: https://github.com/rust-lang/rust/issues/143549
This has one remaining issue, which I could use some help debugging: in
`tests/ui/macros/macro-rules-derive-error.rs`, the diagnostics for
`derive(fn_only)` (for a `fn_only` with no `derive` rules) and
`derive(ForwardReferencedDerive)` both get emitted twice, as a duplicate
diagnostic.
From what I can tell via adding some debugging code,
`unresolved_macro_suggestions` is getting called twice from
`finalize_macro_resolutions` for each of them, because
`self.single_segment_macro_resolutions` has two entries for the macro, with two
different `parent_scope` values. I'm not clear on why that happened; it doesn't
happen with the equivalent code using attrs.
I'd welcome any suggestions for fixing this.
|
|
Port `#[custom_mir(..)]` to the new attribute system
r? ``````````@jdonszelmann``````````
|
|
Revert "Partially outline code inside the panic! macro".
This reverts https://github.com/rust-lang/rust/pull/115670
Without any tests/benchmarks that show some improvement, it's hard to know whether the change had any positive effect. (And if it did, whether that effect is still achieved today.)
|
|
Implement `#[derive(From)]`
Implements the `#[derive(From)]` feature ([tracking issue](https://github.com/rust-lang/rust/issues/144889), [RFC](https://github.com/rust-lang/rfcs/pull/3809)).
It allows deriving the `From` impl on structs and tuple structs with exactly one field. Some implementation notes:
- I wasn't exactly sure which spans to use in the derive generating code, so I just used `span` everywhere. I don't know if it's the Right Thing To Do. In particular the errors when `#[derive(From)]` is used on a struct with an unsized field are weirdly duplicated.
- I had to solve an import stability problem, where if I just added the unstable `macro From` to `core::convert`, previously working code like `use std::convert::From` would suddenly require an unstable feature gate, because rustc would think that you're trying to import the unstable macro. `@petrochenkov` suggested that I add the macro the the core prelude instead. This has worked well, although it only works in edition 2021+. Not sure if I botched the prelude somehow and it should live elsewhere (?).
- I had to add `Ty::AstTy`, because the `from` function receives an argument with the type of the single field, and the existing variants of the `Ty` enum couldn't represent an arbitrary type.
|
|
|
|
|
