Previously, `Tree::from_enum`'s implementation branched into three disjoint
cases:
1. enums that uninhabited
2. enums for which all but one variant is uninhabited
3. enums with multiple inhabited variants
This branching (incorrectly) did not differentiate between variantful and
variantless uninhabited enums. In both cases, we assumed (and asserted) that
uninhabited enums are zero-sized types. This assumption is false for enums like:
enum Uninhabited { A(!, u128) }
...which, currently, has the same size as `u128`. This faulty assumption
manifested as the ICE reported in #126460.
In this PR, we revise the first case of `Tree::from_enum` to consider only the
narrow category of "enums that are uninhabited ZSTs". These enums, whose layouts
are described with `Variants::Single { index }`, are special in their layouts
otherwise resemble the `!` type and cannot be descended into like typical enums.
This first case captures uninhabited enums like:
enum Uninhabited { A(!, !), B(!) }
The second case is revised to consider the broader category of "enums that defer
their layout to one of their variants"; i.e., enums whose layouts are described
with `Variants::Single { index }` and that do have a variant at `index`. This
second case captures uninhabited enums that are not ZSTs, like:
enum Uninhabited { A(!, u128) }
...which represent their variants with `Variants::Single`.
Finally, the third case is revised to cover the broader category of "enums with
multiple variants", which captures uninhabited, non-ZST enums like:
enum Uninhabited { A(u8, !), B(!, u32) }
...which represent their variants with `Variants::Multiple`.
This PR also adds a comment requested by RalfJung in his review of #126358 to
`compiler/rustc_const_eval/src/interpret/discriminant.rs`.
Fixes#126460
I didn't find `crt-static` at first (for `x86_64-unknown-linux-gnu`),
because it was put at the bottom the large and otherwise sorted list.
Fully sort the list before we print it.
Note that `llvm_target_features` starts out sorted and does not need to
be sorted an extra time.
Add a new concat metavar expr
Revival of #111930
Giving it another try now that #117050 was merged.
With the new rules, meta-variable expressions must be referenced with a dollar sign (`$`) and this can cause misunderstands with `$concat`.
```rust
macro_rules! foo {
( $bar:ident ) => {
const ${concat(VAR, bar)}: i32 = 1;
};
}
// Will produce `VARbar` instead of `VAR_123`
foo!(_123);
```
In other words, forgetting the dollar symbol can produce undesired outputs.
cc #29599
cc https://github.com/rust-lang/rust/issues/124225
Rollup of 7 pull requests
Successful merges:
- #123769 (Improve escaping of byte, byte str, and c str proc-macro literals)
- #126054 (`E0229`: Suggest Moving Type Constraints to Type Parameter Declaration)
- #126135 (add HermitOS support for vectored read/write operations)
- #126266 (Unify guarantees about the default allocator)
- #126285 (`UniqueRc`: support allocators and `T: ?Sized`.)
- #126399 (extend the check for LLVM build)
- #126426 (const validation: fix ICE on dangling ZST reference)
r? `@ghost`
`@rustbot` modify labels: rollup
const validation: fix ICE on dangling ZST reference
Fixes https://github.com/rust-lang/rust/issues/126393
I'm not super happy with this fix but I can't think of a better one.
r? `@oli-obk`
`E0229`: Suggest Moving Type Constraints to Type Parameter Declaration
Fixes#113073
This PR suggests `impl<T: Bound> Trait<T> for Foo` when finding `impl Trait<T: Bound> for Foo`. Tangentially, it also improves a handful of other error messages.
It accomplishes this in two steps:
1. Check if constrained arguments and parameter names appear in the same order and delay emitting "incorrect number of generic arguments" error because it can be confusing for the programmer to see `0 generic arguments provided` when there are `n` constrained generic arguments.
2. Inside `E0229`, suggest declaring the type parameter right after the `impl` keyword by finding the relevant impl block's span for type parameter declaration. This also handles lifetime declarations correctly.
Also, the multi part suggestion doesn't use the fluent error mechanism because translating all the errors to fluent style feels outside the scope of this PR. I will handle it in a separate PR if this gets approved.
change method resolution to constrain hidden types instead of rejecting method candidates
Some of these are in probes and may affect inference. This is therefore a breaking change.
This allows new code to compile on stable:
```rust
trait Trait {}
impl Trait for u32 {}
struct Bar<T>(T);
impl Bar<u32> {
fn foo(self) {}
}
fn foo(x: bool) -> Bar<impl Sized> {
if x {
let x = foo(false);
x.foo();
//^ this used to not find the `foo` method, because while we did equate `x`'s type with possible candidates, we didn't allow opaque type inference while doing so
}
todo!()
}
```
r? ```````@compiler-errors```````
fixes #121404
cc https://github.com/rust-lang/rust/issues/116652
const-eval: make lint scope computation consistent
The first commit is some renaming for consistency, but otherwise unrelated. It just didn't feel worth a separate PR, but I can split this up if you prefer.
r? ``@oli-obk``
Tweak output of import suggestions
When both `std::` and `core::` items are available, only suggest the `std::` ones. We ensure that in `no_std` crates we suggest `core::` items.
Ensure that the list of items suggested to be imported are always in the order of local crate items, `std`/`core` items and finally foreign crate items.
Tweak wording of import suggestion: if there are multiple items but they are all of the same kind, we use the kind name and not the generic "items".
Fix#83564.
Add pub struct with allow(dead_code) into worklist
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Fixes#126289
When both `std::` and `core::` items are available, only suggest the
`std::` ones. We ensure that in `no_std` crates we suggest `core::`
items.
Ensure that the list of items suggested to be imported are always in the
order of local crate items, `std`/`core` items and finally foreign crate
items.
Tweak wording of import suggestion: if there are multiple items but they
are all of the same kind, we use the kind name and not the generic "items".
Fix#83564.
Implement lint for obligations broken by never type fallback change
This is the second (and probably last major?) lint required for the never type fallback change.
The idea is to check if the code errors with `fallback = ()` and if it errors with `fallback = !` and if it went from "ok" to "error", lint.
I'm not happy with the diagnostic, ideally we'd highlight what bound is the problem. But I'm really unsure how to do that (cc `@jackh726,` iirc you had some ideas?)
r? `@compiler-errors`
Thanks `@BoxyUwU` with helping with trait solver stuff when I was implementing the initial version of this lint.
Tracking:
- https://github.com/rust-lang/rust/issues/123748
Add a new trait to retrieve StableMir definition Ty
We implement the trait only for definitions that should have a type. It's possible that I missed a few definitions, but we can add them later if needed.
Fixes https://github.com/rust-lang/project-stable-mir/issues/80
Make `try_from_target_usize` method public
There is now no way to create a TyConst from an integer, so I propose making this method public unless there was a reason for keeping it otherwise.
safe transmute: support `Single` enums
Previously, the implementation of `Tree::from_enum` incorrectly treated enums with `Variants::Single` and `Variants::Multiple` identically. This is incorrect for `Variants::Single` enums, which delegate their layout to that of a variant with a particular index (or no variant at all if the enum is empty).
This flaw manifested first as an ICE. `Tree::from_enum` attempted to compute the tag of variants other than the one at `Variants::Single`'s `index`, and fell afoul of a sanity-checking assertion in `compiler/rustc_const_eval/src/interpret/discriminant.rs`. This assertion is non-load-bearing, and can be removed; the routine its in is well-behaved even without it.
With the assertion removed, the proximate issue becomes apparent: calling `Tree::from_variant` on a variant that does not exist is ill-defined. A sanity check the given variant has `FieldShapes::Arbitrary` fails, and the analysis is (correctly) aborted with `Err::NotYetSupported`.
This commit corrects this chain of failures by ensuring that `Tree::from_variant` is not called on variants that are, as far as layout is concerned, nonexistent. Specifically, the implementation of `Tree::from_enum` is now partitioned into three cases:
1. enums that are uninhabited
2. enums for which all but one variant is uninhabited
3. enums with multiple inhabited variants
`Tree::from_variant` is now only invoked in the third case. In the first case, `Tree::uninhabited()` is produced. In the second case, the layout is delegated to `Variants::Single`'s index.
Fixes#125811
docs(rustc): Improve discoverable of Cargo docs
In preparing Cargo's blog post for 1.80, I tried to find the documentation for the lint configuration and I couldn't. The link is only visible from the lint itself, which isn't where I started, and the side bar, which was collapsed for me.
The first place I went was the docs for `unexpected_cfgs` because this is configuration for that lint. If using lint configuration were a one off, I could see skipping it here. However, when we discussed this with at least one T-compiler member, there was interest in using this for other lints in the future. To that end, it seems like we should be exposing this with the lint itself.
The second place I checked was the `check-cfg` documentation. This now has a call out for the sub-page.
Urls to docs in rust_hir
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Harmonize using root or leaf obligation in trait error reporting
When #121826 changed the error reporting to use root obligation and not the leafmost obligation, it didn't actually make sure that all the other diagnostics helper functions used the right obligation.
Specifically, when reporting similar impl candidates we are looking for impls of the root obligation, but trying to match them against the trait ref of the leaf obligation.
This does a few other miscellaneous changes. There's a lot more clean-up that could be done here, but working with this code is really grief-inducing due to how messy it has become over the years. Someone really needs to show it love. 😓
r? ``@estebank``
Fixes#126129
Walk into alias-eq nested goals even if normalization fails
Somewhat broken due to the fact that we don't handle aliases well, nor do we handle ambiguities well. Still want to put up this incremental piece, since it improves type errors for projections whose trait refs are not satisfied.
r? lcnr
Previously, the implementation of `Tree::from_enum` incorrectly
treated enums with `Variants::Single` and `Variants::Multiple`
identically. This is incorrect for `Variants::Single` enums,
which delegate their layout to that of a variant with a particular
index (or no variant at all if the enum is empty).
This flaw manifested first as an ICE. `Tree::from_enum` attempted
to compute the tag of variants other than the one at
`Variants::Single`'s `index`, and fell afoul of a sanity-checking
assertion in `compiler/rustc_const_eval/src/interpret/discriminant.rs`.
This assertion is non-load-bearing, and can be removed; the routine
its in is well-behaved even without it.
With the assertion removed, the proximate issue becomes apparent:
calling `Tree::from_variant` on a variant that does not exist is
ill-defined. A sanity check the given variant has
`FieldShapes::Arbitrary` fails, and the analysis is (correctly)
aborted with `Err::NotYetSupported`.
This commit corrects this chain of failures by ensuring that
`Tree::from_variant` is not called on variants that are, as far as
layout is concerned, nonexistent. Specifically, the implementation
of `Tree::from_enum` is now partitioned into three cases:
1. enums that are uninhabited
2. enums for which all but one variant is uninhabited
3. enums with multiple inhabited variants
`Tree::from_variant` is now only invoked in the third case. In the
first case, `Tree::uninhabited()` is produced. In the second case,
the layout is delegated to `Variants::Single`'s index.
Fixes#125811
We implement the trait only for definitions that should have a type.
It's possible that I missed a few definitions, but we can add them later
if needed.
Extend SCC construction to enable extra functionality
Do YOU feel like your SCC construction doesn't do enough? Then I have a patch for you! SCCs can now do *everything*! Well, almost.
This patch has been extracted from #123720. It specifically enhances
`Sccs` to allow tracking arbitrary commutative properties (think min/max mappings on nodes vs arbitrary closures) of strongly connected components, including
- reachable values (max/min)
- SCC-internal values (max/min)
This helps with among other things universe computation. We can now identify
SCC universes as a reasonably straightforward "find max/min" operation during SCC construction. This is also included in this patch.
It's also more or less zero-cost; don't use the new features, don't pay for them.
This commit also vastly extends the documentation of the SCCs module, which I had a very hard time following. It may or may not have gotten easier to read for someone else.
I believe this logic can also be used in leak check, but haven't checked. Ha. ha. Ha.
rust-lang/rust#120675 introduced a new mechanism to declare intrinsics
which will potentially replace the rust-intrinsic ABI.
The new mechanism introduces a placeholder body and mark the intrinsic
with #[rustc_intrinsic_must_be_overridden].
In practice, this means that backends should not generate code for the
placeholder, and shim the intrinsic.
The new annotation is an internal compiler implementation,
and it doesn't need to be exposed to StableMIR users.
In this PR, intrinsics marked with `rustc_intrinsic_must_be_overridden`
are handled the same way as intrinsics that do not have a body.
Rollup of 8 pull requests
Successful merges:
- #125869 (Add `target_env = "p1"` to the `wasm32-wasip1` target)
- #126019 (Add TODO comment to unsafe env modification)
- #126036 (Migrate `run-make/short-ice` to `rmake`)
- #126276 (Detect pub structs never constructed even though they impl pub trait with assoc constants)
- #126282 (Ensure self-contained linker is only enabled on dev/nightly )
- #126317 (Avoid a bunch of booleans in favor of Result<(), ErrorGuaranteed> as that more robustly proves that an error has been emitted)
- #126324 (Adjust LoongArch64 data layouts for LLVM update)
- #126340 (Fix outdated predacates_of.rs comments)
r? `@ghost`
`@rustbot` modify labels: rollup
This is the first time we have a lint with configuration exposed in
`Cargo.toml`.
When this was done, interest was expressed in using this for other cases
in the future.
To this end, we need to make the documentation for the lint
configuration discoverable from the documentation for that lint.
Fix outdated predacates_of.rs comments
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Avoid a bunch of booleans in favor of Result<(), ErrorGuaranteed> as that more robustly proves that an error has been emitted
pulled out of https://github.com/rust-lang/rust/pull/126316
This PR cannot have any effect on compilation.
All it does is shift a `Ty::new_misc_error` to a `span_delayed_bug` and preserve the `ErrorGuaranteed` in all other cases
Detect pub structs never constructed even though they impl pub trait with assoc constants
Extend dead code analysis to impl items of pub assoc constants.
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Add `target_env = "p1"` to the `wasm32-wasip1` target
This commit sets the `target_env` key for the
`wasm32-wasi{,p1,p1-threads}` targets to the string `"p1"`. This mirrors how the `wasm32-wasip2` target has `target_env = "p2"`. The intention of this is to more easily detect each target in downstream crates to enable adding custom code per-target.
cc #125803
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Rollup of 9 pull requests
Successful merges:
- #126039 (Promote `arm64ec-pc-windows-msvc` to tier 2)
- #126075 (Remove `DebugWithInfcx` machinery)
- #126228 (Provide correct parent for nested anon const)
- #126232 (interpret: dyn trait metadata check: equate traits in a proper way)
- #126242 (Simplify provider api to improve llvm ir)
- #126294 (coverage: Replace the old span refiner with a single function)
- #126295 (No uninitalized report in a pre-returned match arm)
- #126312 (Update `rustc-perf` submodule)
- #126322 (Follow up to splitting core's PanicInfo and std's PanicInfo)
r? `@ghost`
`@rustbot` modify labels: rollup
This version shaves off ca 2% of the cycles in my experiments
and makes the control flow easier to follow for me and hopefully
others, including the compiler.
Someone gave me a working profiler and by God I'm using it.
This patch has been extracted from #123720. It specifically enhances
`Sccs` to allow tracking arbitrary commutative properties of SCCs, including
- reachable values (max/min)
- SCC-internal values (max/min)
This helps with among other things universe computation: we can now identify
SCC universes as a straightforward "find max/min" operation during SCC construction.
It's also more or less zero-cost; don't use the new features, don't pay for them.
This commit also vastly extends the documentation of the SCCs module, which I had a very hard time following.
coverage: Replace the old span refiner with a single function
As more and more of the span refiner's functionality has been pulled out into separate early passes, it has finally reached the point where we can remove the rest of the old `SpansRefiner` code, and replace it with a single modestly-sized function.
~~There should be no change to the resulting coverage mappings, as demonstrated by the lack of changes to test output.~~
There is *almost* no change to the resulting coverage mappings. There are some minor changes to `loop` that on inspection appear to be neutral in terms of accuracy, with the old behaviour being a slightly-horrifying implementation detail of the old code, so I think they're acceptable.
Previous work in this direction includes:
- #125921
- #121019
- #119208
interpret: dyn trait metadata check: equate traits in a proper way
Hopefully fixes https://github.com/rust-lang/miri/issues/3541... unfortunately we don't have a testcase.
The first commit is just a refactor without functional change.
r? `@oli-obk`
Provide correct parent for nested anon const
Fixes#126147
99% of this PR is just comments explaining what the issue is.
`tcx.parent(` and `hir().get_parent_item(` give different results as the hir owner for all the hir of anon consts is the enclosing function. I didn't attempt to change that as being a hir owner requires a `DefId` and long term we want to stop creating anon consts' `DefId`s before hir ty lowering.
So i just opted to change `generics_of` to use `tcx.parent` to get the parent for `AnonConst`'s. I'm not entirely sure about this being what we want, it does seem weird that we have two ways of getting the parent of an `AnonConst` and they both give different results.
Alternatively we could just go ahead and make `const_evaluatable_unchecked` a hard error and stop providing generics to repeat exprs. Then this isn't an issue. (The FCW has been around for almost 4 years now)
r? ````@compiler-errors````
Remove `DebugWithInfcx` machinery
This PR removes `DebugWithInfcx` after having a lot of second thoughts about it due to recent type system uplifting work. We could add it back later if we want, but I don't think the amount of boilerplate in the complier and the existence of (kindof) hacks like `NoInfcx` currently justify the existence of `DebugWithInfcx`, especially since it's not even being used anywhere in the compiler currently.
The motivation for `DebugWithInfcx` is that we want to be able to print infcx-aware information, such as universe information[^1] (though if there are other usages that I'm overlooking, please let me know). I think there are probably more tailored solutions that can specifically be employed in places where this infcx-aware printing is necessary. For example, one way of achieving this is by implementing a custom `FmtPrinter` which overloads `ty_infer_name` (perhaps also extending it to have overrideable stubs for printing placeholders too) to print the `?u.i` name for an infer var. This will necessitate uplifting `Print` from `rustc_middle::ty::print`, but this seems a bit more extensible and reusable than `DebugWithInfcx`.
One of the problems w/ `DebugWithInfcx` is its opt-in-ness. Even if a compiler dev adds a new `debug!(ty)` in a context where there is an `infcx` we can access, they have to *opt-in* to using `DebugWithInfcx` with something like `debug!(infcx.with(ty))`. This feels to me like it risks a lot of boilerplate, and very easy to just forget adding it at all, especially in cases like `#[instrument]`.
A second problem is the `NoInfcx` type itself. It's necessary to have this dummy infcx implementation since we often want to print types outside of the scope of a valid `Infcx`. Right now, `NoInfcx` is only *partially* a valid implementation of `InferCtxtLike`, except for the methods that we specifically need for `DebugWithInfcx`. As I work on uplifting the trait solver, I actually want to add a lot more methods to `InferCtxtLike` and having to add `unreachable!("this should never be called")` stubs for uplifted methods like `next_ty_var` is quite annoying.
In reality, I actually only *really* care about the second problem -- we could, perhaps, instead just try to get rid of `NoInfcx` and just just duplicate `Debug` and `DebugWithInfcx` for most types. If we're okay with duplicating all these implementations (though most of them would just be trivial `#[derive(Debug, DebugWithInfcx)]`), I'd be okay with that too 🤔
r? `@BoxyUwU` `@lcnr` would like to know your thoughts -- happy to discuss this further, mainly trying to bring this problem up
[^1]: Which in my experience is only really necessary when we're debugging things like generalizer bugs.
Add no_std Xtensa targets support
Adds no_std Xtensa targets. This enables using Rust on ESP32, ESP32-S2 and ESP32-S3 chips.
Tier 3 policy:
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
`@MabezDev` and I (`@SergioGasquez)` will maintain the targets.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
The target triple is consistent with other targets.
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
> If possible, use only letters, numbers, dashes and underscores for the name. Periods (.) are known to cause issues in Cargo.
We follow the same naming convention as other targets.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
The target does not introduce any legal issues.
> The target must not introduce license incompatibilities.
There are no license incompatibilities
> Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
Everything added is under that licenses
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
Requirements are not changed for any other target.
> Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
The linker used by the targets is the GCC linker from the GCC toolchain cross-compiled for Xtensa. GNU GPL.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
No such terms exist for this target
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
> This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
Understood
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
The target already implements core.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
Here is how to build for the target https://docs.esp-rs.org/book/installation/riscv-and-xtensa.html and it also covers how to run binaries on the target.
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
> Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Understood
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
> In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
No other targets should be affected
> Tier 3 targets must be able to produce assembly using at least one of rustc's supported backends from any host target.
It can produce assembly, but it requires a custom LLVM with Xtensa support (https://github.com/espressif/llvm-project/). The patches are trying to be upstreamed (https://github.com/espressif/llvm-project/issues/4)
As more and more of the span refiner's functionality has been pulled out into
separate early passes, it has finally reached the point where we can remove the
rest of the old `SpansRefiner` code, and replace it with a single
modestly-sized function.
Rollup of 16 pull requests
Successful merges:
- #123374 (DOC: Add FFI example for slice::from_raw_parts())
- #124514 (Recommend to never display zero disambiguators when demangling v0 symbols)
- #125978 (Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking)
- #125980 (Nvptx remove direct passmode)
- #126187 (For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.)
- #126210 (docs(core): make more const_ptr doctests assert instead of printing)
- #126249 (Simplify `[T; N]::try_map` signature)
- #126256 (Add {{target}} substitution to compiletest)
- #126263 (Make issue-122805.rs big endian compatible)
- #126281 (set_env: State the conclusion upfront)
- #126286 (Make `storage-live.rs` robust against rustc internal changes.)
- #126287 (Update a cranelift patch file for formatting changes.)
- #126301 (Use `tidy` to sort crate attributes for all compiler crates.)
- #126305 (Make PathBuf less Ok with adding UTF-16 then `into_string`)
- #126310 (Migrate run make prefer rlib)
- #126314 (fix RELEASES: we do not support upcasting to auto traits)
r? `@ghost`
`@rustbot` modify labels: rollup
Use `tidy` to sort crate attributes for all compiler crates.
We already do this for a number of crates, e.g. `rustc_middle`, `rustc_span`, `rustc_metadata`, `rustc_span`, `rustc_errors`.
For the ones we don't, in many cases the attributes are a mess.
- There is no consistency about order of attribute kinds (e.g. `allow`/`deny`/`feature`).
- Within attribute kind groups (e.g. the `feature` attributes), sometimes the order is alphabetical, and sometimes there is no particular order.
- Sometimes the attributes of a particular kind aren't even grouped all together, e.g. there might be a `feature`, then an `allow`, then another `feature`.
This commit extends the existing sorting to all compiler crates, increasing consistency. If any new attribute line is added there is now only one place it can go -- no need for arbitrary decisions.
Exceptions:
- `rustc_log`, `rustc_next_trait_solver` and `rustc_type_ir_macros`, because they have no crate attributes.
- `rustc_codegen_gcc`, because it's quasi-external to rustc (e.g. it's ignored in `rustfmt.toml`).
r? `@davidtwco`
Update a cranelift patch file for formatting changes.
PR #125443 will reformat all the use declarations in the repo. This would break a patch kept in `rustc_codegen_cranelift` that gets applied to `library/std/src/sys/pal/windows/rand.rs`.
So this commit formats the use declarations in `library/std/src/sys/pal/windows/rand.rs` in advance of #125443 and updates the patch file accordingly.
The motivation is that #125443 is a huge change and we want to get fiddly little changes like this out of the way so it can be nothing more than an `x fmt --all`.
r? ``@bjorn3``
For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.
Adding suggestions for following function in E0277.
```rust
fn main() {
let mut _file = File::create("foo.txt")?;
}
```
to
```rust
fn main() -> Result<(), Box<dyn std::error::Error>> {
let mut _file = File::create("foo.txt")?;
return Ok(());
}
```
According to the issue #125997, only the code examples in the issue are targeted, but the issue covers a wider range of situations.
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Nvptx remove direct passmode
This PR does what should have been done in #117671. That is fully avoid using the `PassMode::Direct` for `extern "C" fn` for `nvptx64-nvidia-cuda` and enable the compatibility test. `@RalfJung` [pointed me in the right direction](https://github.com/rust-lang/rust/issues/117480#issuecomment-2137712501) for solving this issue.
There are still some ABI bugs after this PR is merged. These ABI tests are created based on what is actually correct, and since they continue passing with even more of them enabled things are improving. I don't have the time to tackle all the remaining issues right now, but I think getting these improvements merged is very valuable in themselves and plan to tackle more of them long term.
This also doesn't remove the use of `PassMode::Direct` for `extern "ptx-kernel" fn`. This was also not trivial to make work. And since the ABI is hidden behind an unstable feature it's less urgent.
I don't know if it's correct to request `@RalfJung` as a reviewer (due to team structures), but he helped me a lot to figure out this stuff. If that's not appropriate then `@davidtwco` would be a good candidate since he know about this topic from #117671
r? `@RalfJung`
Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking
Use `probe_assoc_item` (for hygienically probing an assoc item and checking if it's accessible wrt. visibility and stability) for assoc item constraints, too, not just for assoc type paths and make the privacy error translatable.
We already do this for a number of crates, e.g. `rustc_middle`,
`rustc_span`, `rustc_metadata`, `rustc_span`, `rustc_errors`.
For the ones we don't, in many cases the attributes are a mess.
- There is no consistency about order of attribute kinds (e.g.
`allow`/`deny`/`feature`).
- Within attribute kind groups (e.g. the `feature` attributes),
sometimes the order is alphabetical, and sometimes there is no
particular order.
- Sometimes the attributes of a particular kind aren't even grouped
all together, e.g. there might be a `feature`, then an `allow`, then
another `feature`.
This commit extends the existing sorting to all compiler crates,
increasing consistency. If any new attribute line is added there is now
only one place it can go -- no need for arbitrary decisions.
Exceptions:
- `rustc_log`, `rustc_next_trait_solver` and `rustc_type_ir_macros`,
because they have no crate attributes.
- `rustc_codegen_gcc`, because it's quasi-external to rustc (e.g. it's
ignored in `rustfmt.toml`).
Make `ObligationEmittingRelation`s emit `Goal` rather than `Obligation`
Helps avoid needing to uplift `Obligation` into the solver. We still can't get rid of `ObligationCause`, but we can keep it as an associated type for `InferCtxtLike` and just give it a `dummy` function.
There's some shuttling between `Goal` and `Obligation` that may be perf-sensitive... Let's see what rust-timer says.
r? lcnr
Edition 2024: Make `!` fall back to `!`
This PR changes never type fallback to be `!` (the never type itself) in the next, 2024, edition.
This makes the never type's behavior more intuitive (in 2024 edition) and is the first step of the path to stabilize it.
r? `@compiler-errors`
PR #125443 will reformat all the use declarations in the repo. This
would break a patch kept in `rustc_codegen_cranelift` that gets applied
to `library/std/src/sys/pal/windows/rand.rs`.
So this commit formats the use declarations in
`library/std/src/sys/pal/windows/rand.rs` in advance of #125443 and
updates the patch file accordingly.
The motivation is that #125443 is a huge change and we want to get
fiddly little changes like this out of the way so it can be nothing more
than an `x fmt --all`.
Rollup of 6 pull requests
Successful merges:
- #115974 (Split core's PanicInfo and std's PanicInfo)
- #125659 (Remove usage of `isize` in example)
- #125669 (CI: Update riscv64gc-linux job to Ubuntu 22.04, rename to riscv64gc-gnu)
- #125684 (Account for existing bindings when suggesting `pin!()`)
- #126055 (Expand list of trait implementers in E0277 when calling rustc with --verbose)
- #126174 (Migrate `tests/run-make/prefer-dylib` to `rmake.rs`)
r? `@ghost`
`@rustbot` modify labels: rollup
Account for existing bindings when suggesting `pin!()`
When we encounter a situation where we'd suggest `pin!()`, we now account for that expression existing as part of an assignment and provide an appropriate suggestion:
```
error[E0599]: no method named `poll` found for type parameter `F` in the current scope
--> $DIR/pin-needed-to-poll-3.rs:19:28
|
LL | impl<F> Future for FutureWrapper<F>
| - method `poll` not found for this type parameter
...
LL | let res = self.fut.poll(cx);
| ^^^^ method not found in `F`
|
help: consider pinning the expression
|
LL ~ let mut pinned = std::pin::pin!(self.fut);
LL ~ let res = pinned.as_mut().poll(cx);
|
```
Fix#125661.
Split core's PanicInfo and std's PanicInfo
`PanicInfo` is used in two ways:
1. As argument to the `#[panic_handler]` in `no_std` context.
2. As argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in `std` context.
In situation 1, the `PanicInfo` always has a *message* (of type `fmt::Arguments`), but never a *payload* (of type `&dyn Any`).
In situation 2, the `PanicInfo` always has a *payload* (which is often a `String`), but not always a *message*.
Having these as the same type is annoying. It means we can't add `.message()` to the first one without also finding a way to properly support it on the second one. (Which is what https://github.com/rust-lang/rust/issues/66745 is blocked on.)
It also means that, because the implementation is in `core`, the implementation cannot make use of the `String` type (which doesn't exist in `core`): 0692db1a90/library/core/src/panic/panic_info.rs (L171-L172)
This also means that we cannot easily add a useful method like `PanicInfo::payload_as_str() -> Option<&str>` that works for both `&'static str` and `String` payloads.
I don't see any good reasons for these to be the same type, other than historical reasons.
---
This PR is makes 1 and 2 separate types. To try to avoid breaking existing code and reduce churn, the first one is still named `core::panic::PanicInfo`, and `std::panic::PanicInfo` is a new (deprecated) alias to `PanicHookInfo`. The crater run showed this as a viable option, since people write `core::` when defining a `#[panic_handler]` (because they're in `no_std`) and `std::` when writing a panic hook (since then they're definitely using `std`). On top of that, many definitions of a panic hook don't specify a type at all: they are written as a closure with an inferred argument type.
(Based on some thoughts I was having here: https://github.com/rust-lang/rust/pull/115561#issuecomment-1725830032)
---
For the release notes:
> We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0.
>
> `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*.
>
> The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`.
Print `token::Interpolated` with token stream pretty printing.
This is a step towards removing `token::Interpolated` (#124141). It unavoidably changes the output of the `stringify!` macro, generally for the better.
r? `@petrochenkov`
interpret: ensure we check bool/char for validity when they are used in a cast
In general, `Scalar::to_bits` is a bit dangerous as it bypasses all type information. We should usually prefer matching on the type and acting according to that. So I also refactored `unary_op` handling of integers to do that. The remaining `to_bits` uses are operations that just fundamentally don't care about the sign (and only work on integers).
invalid_char_cast.rs is the key new test, the others already passed before this PR.
r? `@oli-obk`
Rollup of 5 pull requests
Successful merges:
- #125913 (Spruce up the diagnostics of some early lints)
- #126234 (Delegation: fix ICE on late diagnostics)
- #126253 (Simplify assert matchers in `run-make-support`)
- #126257 (Rename `needs-matching-clang` to `needs-force-clang-based-tests`)
- #126259 (reachable computation: clarify comments around consts)
r? `@ghost`
`@rustbot` modify labels: rollup
Spruce up the diagnostics of some early lints
Implement the various "*(note to myself) in a follow-up PR we should turn parts of this message into a subdiagnostic (help msg or even struct sugg)*" drive-by comments I left in #124417 during my review.
For context, before #124417, only a few early lints touched/decorated/customized their diagnostic because the former API made it a bit awkward. Likely because of that, things that should've been subdiagnostics were just crammed into the primary message. This PR rectifies this.
Only compute `specializes` query if (min)specialization is enabled in the crate of the specializing impl
Fixes (after backport) https://github.com/rust-lang/rust/issues/125197
### What
https://github.com/rust-lang/rust/pull/122791 makes it so that inductive cycles are no longer hard errors. That means that when we are testing, for example, whether these impls overlap:
```rust
impl PartialEq<Self> for AnyId {
fn eq(&self, _: &Self) -> bool {
todo!()
}
}
impl<T: Identifier> PartialEq<T> for AnyId {
fn eq(&self, _: &T) -> bool {
todo!()
}
}
```
...given...
```rust
pub trait Identifier: Display + 'static {}
impl<T> Identifier for T where T: PartialEq + Display + 'static {}
```
Then we try to see if the second impl holds given `T = AnyId`. That requires `AnyId: Identifier`, which requires that `AnyId: PartialEq`, which is satisfied by these two impl candidates... The `PartialEq<T>` impl is a cycle, and we used to winnow it when we used to treat inductive cycles as errors.
However, now that we don't winnow it, this means that we *now* try calling `candidate_should_be_dropped_in_favor_of`, which tries to check whether one of the impls specializes the other: the `specializes` query. In that query, we currently bail early if the impl is local.
However, in a foreign crate, we try to compute if the two impls specialize each other by doing trait solving. This may itself lead to the same situation where we call `specializes`, which will lead to a query cycle.
### How does this fix the problem
We now record whether specialization is enabled in foreign crates, and extend this early-return behavior to foreign impls too. This means that we can only encounter these cycles if we truly have a specializing impl from a crate with specialization enabled.
-----
r? `@oli-obk` or `@lcnr`
Add `SingleUseConsts` mir-opt pass
The goal here is to make a pass that can be run in debug builds to simplify the common case of constants that are used just once -- that doesn't need SSA handling and avoids any potential downside of multi-use constants. In particular, to simplify the `if T::IS_ZST` pattern that's common in the standard library.
By also handling the case of constants that are *never* actually used this fully replaces the `ConstDebugInfo` pass, since it has all the information needed to do that naturally from the traversal it needs to do anyway.
This is roughly a wash on instructions on its own (a couple regressions, a few improvements https://github.com/rust-lang/rust/pull/125910#issuecomment-2144963361), with a bunch of size improvements. So I'd like to land it as its own PR, then do follow-ups to take more advantage of it (in the inliner, cg_ssa, etc).
r? `@saethlin`
Add explanatory note to async block type mismatch error
The async block type mismatch error might leave the user wondering as to why it occurred. The new note should give them the needed context.
Changes this diagnostic:
```
error[E0308]: mismatched types
--> src/main.rs:5:23
|
2 | let a = async { 1 };
| ----------- the expected `async` block
3 | let b = async { 2 };
| ----------- the found `async` block
4 |
5 | let bad = vec![a, b];
| ^ expected `async` block, found a different `async` block
|
= note: expected `async` block `{async block@src/main.rs:2:13: 2:24}`
found `async` block `{async block@src/main.rs:3:13: 3:24}`
```
to this:
```
error[E0308]: mismatched types
--> src/main.rs:5:23
|
2 | let a = async { 1 };
| ----------- the expected `async` block
3 | let b = async { 2 };
| ----------- the found `async` block
4 |
5 | let bad = vec![a, b];
| ^ expected `async` block, found a different `async` block
|
= note: expected `async` block `{async block@src/main.rs:2:13: 2:24}`
found `async` block `{async block@src/main.rs:3:13: 3:24}`
= note: no two async blocks, even if identical, have the same type
= help: consider pinning your async block and and casting it to a trait object
```
Fixes#125737
Fix ICE due to `unwrap` in `probe_for_name_many`
Fixes#125876
Now `probe_for_name_many` bubbles up the error returned by `probe_op` instead of calling `unwrap` on it.
Enable GVN for `AggregateKind::RawPtr`
Looks like I was worried for nothing; this seems like it's much easier than I was originally thinking it would be.
r? `@cjgillot`
This should be useful for `x[..4]`-like things, should those start inlining enough to expose the lengths.
simd packed types: remove outdated comment, extend codegen test
It seems like https://github.com/rust-lang/rust/pull/125311 made that check in codegen unnecessary?
r? `@workingjubilee` `@calebzulawski`
offset_of: allow (unstably) taking the offset of slice tail fields
Fields of type `[T]` have a statically known offset, so there is no reason to forbid them in `offset_of!`. This PR adds the `offset_of_slice` feature to allow them.
I created a tracking issue: https://github.com/rust-lang/rust/issues/126151.
mark binding undetermined if target name exist and not obtained
- Fixes#124490
- Fixes#125013
Following up on #124840, I think handling only `target_bindings` is sufficient.
r? `@petrochenkov`
Revert "Use the HIR instead of mir_keys for determining whether something will have a MIR body."
This reverts commit e5cba17b84.
turns out SMIR still needs it (https://github.com/model-checking/kani/issues/3218). I'll create a full plan and MCP for what I intended this to be a part of. Maybe my plan is nonsense anyway.
Detect pub structs never constructed and unused associated constants
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Lints never constructed public structs.
If we don't provide public methods to construct public structs with private fields, and don't construct them in the local crate. They would be never constructed. So that we can detect such public structs.
---
Update:
Also lints unused associated constants in traits.
Parse unsafe attributes
Initial parse implementation for #123757
This is the initial work to parse unsafe attributes, which is represented as an extra `unsafety` field in `MetaItem` and `AttrItem`. There's two areas in the code where it appears that parsing is done manually and not using the parser stuff, and I'm not sure how I'm supposed to thread the change there.
Revert: create const block bodies in typeck via query feeding
as per the discussion in https://github.com/rust-lang/rust/pull/125806#discussion_r1622563948
It was a mistake to try to shoehorn const blocks and some specific anon consts into the same box and feed them during typeck. It turned out not simplifying anything (my hope was that we could feed `type_of` to start avoiding the huge HIR matcher, but that didn't work out), but instead making a few things more fragile.
reverts the const-block-specific parts of https://github.com/rust-lang/rust/pull/124650
`@bors` rollup=never had a small perf impact previously
fixes https://github.com/rust-lang/rust/issues/125846
r? `@compiler-errors`
Revert "Disallow ambiguous attributes on expressions" on nightly
As discussed in [today's t-compiler meeting](https://rust-lang.zulipchat.com/#narrow/stream/238009-t-compiler.2Fmeetings/topic/.5Bweekly.5D.202024-06-06/near/443079505), this reverts PR #124099 to fix P-critical beta regressions #125199.
r? ``@wesleywiser``
Opening as draft so that ``@wesleywiser`` and ``@apiraino,`` you can tell me whether you wanted:
1. a `beta-accepted` revert of #124099 on nightly (this PR)? That will need to be backported to beta (even though #126093 may be the last of those)
2. a revert of #124099 on beta?
3. all of the above?
I also opened #126102, another draft PR to revert #124099 on beta, should you choose options 2 or 3.
Don't warn on fields in the `unreachable_pub` lint
This PR restrict the `unreachable_pub` lint by not linting on `pub` fields of `pub(restricted)` structs and unions. This is done because that can quickly clutter the code for an uncertain value, in particular since the "real" visibility is defined by the parent (the struct it-self).
This is meant to address one of the last concern of the `unreachable_pub` lint.
r? ``@petrochenkov``
Rollup of 12 pull requests
Successful merges:
- #125220 (Repair several `riscv64gc-unknown-linux-gnu` codegen tests)
- #126033 (CI: fix publishing of toolstate history)
- #126034 (Clarify our tier 1 Windows Server support)
- #126035 (Some minor query system cleanups)
- #126051 (Clarify an `x fmt` error.)
- #126059 (Raise `DEFAULT_MIN_STACK_SIZE` to at least 64KiB)
- #126064 (Migrate `run-make/manual-crate-name` to `rmake.rs`)
- #126072 (compiletest: Allow multiple `//@ run-flags:` headers)
- #126073 (Port `tests/run-make-fulldeps/obtain-borrowck` to ui-fulldeps)
- #126081 (Do not use relative paths to Rust source root in run-make tests)
- #126086 (use windows compatible executable name for libcxx-version)
- #126096 ([RFC-2011] Allow `core_intrinsics` when activated)
r? `@ghost`
`@rustbot` modify labels: rollup
Some minor query system cleanups
* Improves diagnostics on conflicting query flags
* removes unnecessary impls
* `track_caller`
pulled out of https://github.com/rust-lang/rust/pull/115613
Directly add extension instead of using `Path::with_extension`
`Path::with_extension` has a nice footgun when the original path doesn't contain an extension: Anything after the last dot gets removed.
