Consolidate opaque ty and async fn lowering code
The codepaths for lowering "regular" opaques and async fn were almost identical, modulo some bookkeeping that seemed pretty easy to consolidate.
r? `@cjgillot`
Also ICE when goals go from Ok to Err in new solver
We were just using `?` here, silently downgrading the goal's response from (presumably) maybe to error -- that seems concerning, since this whole check is for detecting goal instability 😅
r? `@lcnr` or `@BoxyUwU`
Avoid invalid NaN lint machine-applicable suggestion in const context
This PR removes the machine-applicable suggestion in const context for the `invalid_nan_comparision` lint ~~and replace it with a simple help~~.
Fixes https://github.com/rust-lang/rust/issues/114471
Fix missing dependency file with `-Zunpretty`
This PR force the `output_filenames` to be run ~~in every early exits like~~ when using `-Zunpretty`, so to respect the `dep-info` flag.
Fixes https://github.com/rust-lang/rust/issues/112898
r? `@oli-obk`
Resolve visibility paths as modules not as types.
Asking for a resolution with `opt_ns = Some(TypeNS)` allows path resolution to look for type-relative paths, leaving unresolved segments behind. However, for visibility paths we really need to look for a module, so we need to pass `opt_ns = None`.
Fixes https://github.com/rust-lang/rust/issues/109146
r? `@petrochenkov`
Do not run ConstProp on mir_for_ctfe.
This pass does not seem to be useful any more. The const-prop lints are now run by `tcx.mir_drops_elaborated_and_const_checked`, and the const-prop opt should never emit any diagnostic.
Convert builtin "global" late lints to run per module
The compiler currently has 4 non-incremental lints:
1. `clashing_extern_declarations`;
2. `missing_debug_implementations`;
3. ~`unnameable_test_items`;~ changed by https://github.com/rust-lang/rust/pull/114414
4. `missing_docs`.
Non-incremental lints get reexecuted for each compilation, which is slow. Moreover, those lints are allow-by-default, so run for nothing most of the time. This PR attempts to make them more incremental-friendly.
`clashing_extern_declarations` is moved to a standalone query.
`missing_debug_implementation` can use `non_blanket_impls_for_ty` instead of recomputing it.
`missing_docs` is harder as it needs to track if there is a `doc(hidden)` module surrounding. I hack around this using the lint level engine. That's easy to implement and allows to re-enable the lint for a re-exported module, while a more proper solution would reuse the same device as `unnameable_test_items`.
Rollup of 5 pull requests
Successful merges:
- #114287 (update overflow handling in the new trait solver)
- #114475 (Migrate GUI colors test to original CSS color format)
- #114482 (Fix ui-fulldeps missing the `internal_features` lint on stage 0)
- #114490 (Fix a typo in the error reporting for sealed traits.)
- #114491 (Rename issue #114423 test files to include context)
r? `@ghost`
`@rustbot` modify labels: rollup
update overflow handling in the new trait solver
implements https://hackmd.io/QY0dfEOgSNWwU4oiGnVRLw?view. I want to clean up this doc and add it to the rustc-dev-guide, but I think this PR is ready for merge as is, even without the dev-guide entry.
r? `@compiler-errors`
Re-enable atomic loads and stores for all RISC-V targets
This roughly reverts PR https://github.com/rust-lang/rust/pull/66548
Atomic "CAS" are still disabled for targets without the *“A” Standard Extension for Atomic Instructions*. However this extension only adds instructions for operations more complex than simple loads and stores, which are always atomic when aligned.
In the [Unprivileged Spec v. 20191213](https://riscv.org/technical/specifications/) section 2.6 *Load and Store Instructions* of chapter 2 *RV32I Base Integer Instruction Set* (emphasis mine):
> Even when misaligned loads and stores complete successfully, these accesses might run extremely slowly depending on the implementation (e.g., when implemented via an invisible trap). Further-more, whereas **naturally aligned loads and stores are guaranteed to execute atomically**, misaligned loads and stores might not, and hence require additional synchronization to ensure atomicity.
Unfortunately PR https://github.com/rust-lang/rust/pull/66548 did not provide much details on the bug that motivated it, but https://github.com/rust-lang/rust/issues/66240 and https://github.com/rust-lang/rust/issues/85736 appear related and happen with targets that do have the A extension.
Add separate feature gate for async fn track caller
This patch adds a feature gate `async_fn_track_caller` that is separate from `closure_track_caller`. This is to allow enabling `async_fn_track_caller` separately.
Fixes#110009
Improve spans for indexing expressions
fixes#114388
Indexing is similar to method calls in having an arbitrary left-hand-side and then something on the right, which is the main part of the expression. Method calls already have a span for that right part, but indexing does not. This means that long method chains that use indexing have really bad spans, especially when the indexing panics and that span in coverted into a panic location.
This does the same thing as method calls for the AST and HIR, storing an extra span which is then put into the `fn_span` field in THIR.
r? compiler-errors
[rustc_span][perf] Remove unnecessary string joins and allocs.
Comparing vectors of string parts yields the same result but avoids unnecessary `join` and potential allocation for resulting `String`. This code is cold so it's unlikely to have any measurable impact, but considering but since it's also simpler, why not? :)
Lots of tiny incremental simplifications of `EmitterWriter` internals
ignore the first commit, it's https://github.com/rust-lang/rust/pull/114088 squashed and rebased, but it's needed to use to use `derive_setters`, as they need a newer `syn` version.
Then this PR starts out with removing many arguments that are almost always defaulted to `None` or `false` and replace them with builder methods that can set these fields in the few cases that want to set them.
After that it's one commit after the other that removes or merges things until everything becomes some very simple trait objects
```
error[E0599]: no method named `x` found for struct `Pin<&S>` in the current scope
--> $DIR/arbitrary_self_type_mut_difference.rs:11:18
|
LL | Pin::new(&S).x();
| ^ help: there is a method with a similar name: `y`
|
note: method is available for `Pin<&mut S>`
--> $DIR/arbitrary_self_type_mut_difference.rs:6:5
|
LL | fn x(self: Pin<&mut Self>) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^
```
Related to #57994, as one of the presented cases can lead to code like
this.
This deduplicates some logic and makes it easier to follow what wrappers
are produced. In the future it may allow moving the code to determine
which wrappers to create to cg_ssa.
Indexing is similar to method calls in having an arbitrary
left-hand-side and then something on the right, which is the main part
of the expression. Method calls already have a span for that right part,
but indexing does not. This means that long method chains that use
indexing have really bad spans, especially when the indexing panics and
that span in coverted into a panic location.
This does the same thing as method calls for the AST and HIR, storing an
extra span which is then put into the `fn_span` field in THIR.
Rework upcasting confirmation to support upcasting to fewer projections in target bounds
This PR implements a modified trait upcasting algorithm that is resilient to changes in the number of associated types in the bounds of the source and target trait objects.
It does this by equating each bound of the target trait ref individually against the bounds of the source trait ref, rather than doing them all together by constructing a new trait object.
#### The new way we do trait upcasting confirmation
1. Equate the target trait object's principal trait ref with one of the supertraits of the source trait object's principal.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2509-L2525)
2. Make sure that every auto trait in the *target* trait object is present in the source trait ref's bounds.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2559-L2562)
3. For each projection in the *target* trait object, make sure there is exactly one projection that equates with it in the source trait ref's bound. If there is more than one, bail with ambiguity.
fdcab310b2/compiler/rustc_trait_selection/src/traits/select/mod.rs (L2526-L2557)
* Since there may be more than one that applies, we probe first to check that there is exactly one, then we equate it outside of a probe once we know that it's unique.
4. Make sure the lifetime of the source trait object outlives the lifetime of the target.
<details>
<summary>Meanwhile, this is how we used to do upcasting:</summary>
1. For each supertrait of the source trait object, take that supertrait, append the source object's projection bounds, and the *target* trait object's auto trait bounds, and make this into a new object type:
d12c6e947c/compiler/rustc_trait_selection/src/traits/select/confirmation.rs (L915-L929)
2. Then equate it with the target trait object:
d12c6e947c/compiler/rustc_trait_selection/src/traits/select/confirmation.rs (L936)
This will be a type mismatch if the target trait object has fewer projection bounds, since we compare the bounds structurally in relate:
d12c6e947c/compiler/rustc_middle/src/ty/relate.rs (L696-L698)
</details>
Fixes#114035
Also fixes#114113, because I added a normalize call in the old solver.
r? types
resolve before canonicalization in new solver, ICE if unresolved
Fold the values with a resolver before canonicalization instead of making it happen within canonicalization.
This allows us to filter trivial region constraints from the external constraints.
r? ``@lcnr``
Perform OpaqueCast field projection on HIR, too.
fixes#105819
This is necessary for closure captures in 2021 edition, as they capture individual fields, not the full mentioned variables. So it may try to capture a field of an opaque (because the hidden type is known to be something with a field).
See https://github.com/rust-lang/rust/pull/99806 for when and why we added OpaqueCast to MIR.
cg_llvm: stop identifying ADTs in LLVM IR
This is an extension of https://github.com/rust-lang/rust/pull/94107. It may be a minor perf win.
Fixes#96242.
Now that we use opaque pointers, ADTs can no longer be recursive, so we
do not need to name them. Previously, this would be necessary if you had
a struct like
```rs
struct Foo(Box<Foo>, u64, u64);
```
which would be represented with something like
```ll
%Foo = type { %Foo*, i64, i64 }
```
which is now just
```ll
{ ptr, i64, i64 }
```
r? `@tmiasko`
Enable tests on rustc_codegen_ssa
This enables unittests in rustc_codegen_ssa. There are some tests, primarily in [`back/rpath/tests.rs`](https://github.com/rust-lang/rust/blob/HEAD/compiler/rustc_codegen_ssa/src/back/rpath/tests.rs) that haven't ever been running since the unittests are disabled. From what I can tell, this was just a consequence of how things evolved. When testing was initially added in https://github.com/rust-lang/rust/pull/33282, `librustc_trans` had test=false because it didn't have any tests. `rustc_codegen_ssa` eventually split off from that (https://github.com/rust-lang/rust/pull/55627), and the rpath module eventually got merged in too (from `librustc_back` where it used to live). That migration didn't enable the tests.
This also includes some fluent diagnostic tests, though I'm not sure what exactly they are testing.
Forbid old-style `simd_shuffleN` intrinsics
Don't merge before https://github.com/rust-lang/packed_simd/pull/350 has made its way to crates.io
We used to support specifying the lane length of simd_shuffle ops by attaching the lane length to the name of the intrinsic (like `simd_shuffle16`). After this PR, you cannot do that anymore, and need to instead either rely on inference of the `idx` argument type or specify it as `simd_shuffle::<_, [u32; 16], _>`.
r? `@workingjubilee`
Only unpack tupled args in inliner if we expect args to be unpacked
`"rust-call"` is a strange function abi. sometimes, it expects the arguments to be unpacked by the caller and passed as individual args (closure bodies), and sometimes it does not (user functions annotated with the `"rust-call"` abi).
make sure the mir inliner respects this difference when checking that arguments are compatible, and doesn't try to ICE when we call a `extern "rust-call"` function in a generic context.
fixes#110829
Add `internal_features` lint
Implements https://github.com/rust-lang/compiler-team/issues/596
Also requires some more test blessing for codegen tests etc
`@jyn514` had the idea of just `allow`ing the lint by default in the test suite. I'm not sure whether this is a good idea, but it's definitely one worth considering. Additional input encouraged.
const validation: point at where we found a pointer but expected an integer
Instead of validation just printing "unable to turn pointer into bytes", make this a regular validation error that says where in the value the bad pointer was found. Also distinguish "expected integer, got pointer" from "expected pointer, got partial pointer or mix of pointers".
To avoid duplicating things too much I refactored the diagnostics for validity a bit, so that "got uninit, expected X" and "got pointer, expected X" can share the "X" part. Also all the errors emitted for validation are now grouped under `const_eval_validation` so that they are in a single group in the ftl file.
r? `@oli-obk`
parser: more friendly hints for handling `async move` in the 2015 edition
Fixes#114219
An error is emitted when encountering an async move block in the 2015 edition.
Another appropriate location to raise an error is after executing [let path = this.parse_path(PathStyle::Expr)?](https://github.com/rust-lang/rust/blob/master/compiler/rustc_parse/src/parser/stmt.rs#L152), but it seems somewhat premature to invoke `create_err` at that stage.
Expand, rename and improve `incorrect_fn_null_checks` lint
This PR,
- firstly, expand the lint by now linting on references
- secondly, it renames the lint `incorrect_fn_null_checks` -> `useless_ptr_null_checks`
- and thirdly it improves the lint by catching `ptr::from_mut`, `ptr::from_ref`, as well as `<*mut _>::cast` and `<*const _>::cast_mut`
Fixes https://github.com/rust-lang/rust/issues/113601
cc ```@est31```
It lints against features that are inteded to be internal to the
compiler and standard library. Implements MCP #596.
We allow `internal_features` in the standard library and compiler as those
use many features and this _is_ the standard library from the "internal to the compiler and
standard library" after all.
Marking some features as internal wasn't exactly the most scientific approach, I just marked some
mostly obvious features. While there is a categorization in the macro,
it's not very well upheld (should probably be fixed in another PR).
We always pass `-Ainternal_features` in the testsuite
About 400 UI tests and several other tests use internal features.
Instead of throwing the attribute on each one, just always allow them.
There's nothing wrong with testing internal features^^
Infer type in irrefutable slice patterns with fixed length as array
Fixes https://github.com/rust-lang/rust/issues/76342
In irrefutable slice patterns with a fixed length, we can infer the type as an array type. We now choose to prefer some implementations over others, e.g. in:
```
struct Zeroes;
const ARR: [usize; 2] = [0; 2];
const ARR2: [usize; 2] = [2; 2];
impl Into<&'static [usize; 2]> for Zeroes {
fn into(self) -> &'static [usize; 2] {
&ARR
}
}
impl Into<&'static [usize]> for Zeroes {
fn into(self) -> &'static [usize] {
&ARR2
}
}
fn main() {
let &[a, b] = Zeroes.into();
}
```
We now prefer the impl candidate `impl Into<&'static [usize; 2]> for Zeroes`, it's not entirely clear to me that this is correct, but given that the slice impl would require a type annotation anyway, this doesn't seem unreasonable.
r? `@lcnr`
Fix suggestion spans for expr from macro expansions
### Issue #112007: rustc shows expanded `writeln!` macro in code suggestion
#### Before This PR
```
help: consider using a semicolon here
|
6 | };
| +
help: you might have meant to return this value
--> C:\Users\hayle\.rustup\toolchains\nightly-x86_64-pc-windows-msvc\lib/rustlib/src/rust\library\core\src\macros\mod.rs:557:9
|
55| return $dst.write_fmt($crate::format_args_nl!($($arg)*));
| ++++++ +
```
#### After This PR
```
help: consider using a semicolon here
|
LL | };
| +
help: you might have meant to return this value
|
LL | return writeln!(w, "but not here");
| ++++++ +
```
### Issue #110017: `format!` `.into()` suggestion deletes the `format` macro
#### Before This PR
```
help: call `Into::into` on this expression to convert `String` into `Box<dyn std::error::Error>`
--> /Users/eric/.rustup/toolchains/nightly-aarch64-apple-darwin/lib/rustlib/src/rust/library/alloc/src/macros.rs:121:12
|
12| res.into()
| +++++++
```
#### After This PR
```
help: call `Into::into` on this expression to convert `String` into `Box<dyn std::error::Error>`
|
LL | Err(format!("error: {x}").into())
| +++++++
```
---
Fixes#112007.
Fixes#110017.
Miscellaneous HIR typeck nits
Remove some check functions that only have one usage
Also remove `Expectation::IsLast`, which was both undocumented, and was also made redundant by my cleanup/fix in #103987😸
Suggest `x build library` for a custom toolchain that fails to load `core`
Fixes#113222
The nicer suggestion for dev-channel won't be emitted if `-Z ui-testing` enabled. IMO, this is acceptable for now.
It's the same as `Delimiter`, minus the `Invisible` variant. I'm
generally in favour of using types to make impossible states
unrepresentable, but this one feels very low-value, and the conversions
between the two types are annoying and confusing.
Look at the change in `src/tools/rustfmt/src/expr.rs` for an example:
the old code converted from `MacDelimiter` to `Delimiter` and back
again, for no good reason. This suggests the author was confused about
the types.
This patch adds a feature gate `async_fn_track_caller` that is separate from `closure_track_caller`. This is to allow enabling `async_fn_track_caller` separately.
Fixes#110009
Exporting `__rust_alloc_error_handler_should_panic` multiple times
causes ld.gold to balk with: `error: version script assignment of to
symbol __rust_alloc_error_handler_should_panic failed: symbol not
defined`
Specifically this breaks builds on DragonFly and YoctoProject with
ld.gold. Builds with ld.bfd should be unaffected.
Rollup of 5 pull requests
Successful merges:
- #114079 (Use `upvar_tys` in more places, make it return a list)
- #114166 (Add regression test for resolving `--extern libc=test.rlib`)
- #114321 (get auto traits for parallel rustc)
- #114335 (fix and extend ptr_comparison test)
- #114347 (x.py print more detailed format files and untracked files count)
r? `@ghost`
`@rustbot` modify labels: rollup
Improve `invalid_reference_casting` lint
This PR is a follow-up to https://github.com/rust-lang/rust/pull/111567 and https://github.com/rust-lang/rust/pull/113422.
This PR does multiple things:
- First it adds support for deferred de-reference, the goal is to support code like this, where the casting and de-reference are not done on the same expression
```rust
let myself = self as *const Self as *mut Self;
*myself = Self::Ready(value);
```
- Second it does not lint anymore on SB/TB UB code by only checking assignments (`=`, `+=`, ...) and creation of mutable references `&mut *`
- Thirdly it greatly improves the diagnostics in particular for cast from `&mut` to `&mut` or assignments
- ~~And lastly it renames the lint from `cast_ref_to_mut` to `invalid_reference_casting` which is more consistent with the ["rules"](https://github.com/rust-lang/rust-clippy/issues/2845) and also more consistent with what the lint checks~~ *https://github.com/rust-lang/rust/pull/113422*
This PR is best reviewed commit by commit.
r? compiler
Miri: fix error on dangling pointer inbounds offset
We used to claim that the pointer was "dereferenced", but that is just not true.
Can be reviewed commit-by-commit. The first commit is an unrelated rename that didn't seem worth splitting into its own PR.
r? `@oli-obk`
coverage: Consolidate FFI types into one module
Coverage FFI types were historically split across two modules, because some of them were needed by code in `rustc_codegen_ssa`.
Now that all of the coverage codegen code has been moved into `rustc_codegen_llvm` (#113355), it's possible to move all of the FFI types into a single module, making it easier to see all of them at once.
---
This PR only moves code and adjusts imports; there should be no functional changes.
Coverage FFI types were historically split across two modules, because some of
them were needed by code in `rustc_codegen_ssa`.
Now that all of the coverage codegen code has been moved into
`rustc_codegen_llvm` (#113355), it's possible to move all of the FFI types into
a single module, making it easier to see all of them at once.
Rollup of 6 pull requests
Successful merges:
- #114178 (Account for macros when suggesting a new let binding)
- #114199 (Don't unsize coerce infer vars in select in new solver)
- #114301 (Don't check unnecessarily that impl trait is RPIT)
- #114314 (Tweaks to `adt_sized_constraint`)
- #114322 (Fix invalid slice coercion suggestion reported in turbofish)
- #114340 ([rustc_attr][nit] Replace `filter` + `is_some` with `map_or`.)
r? `@ghost`
`@rustbot` modify labels: rollup
Fix invalid slice coercion suggestion reported in turbofish
This PR fixes the invalid slice coercion suggestion reported in turbofish and inferred generics by not emitting them.
Fixes https://github.com/rust-lang/rust/issues/110063
Don't check unnecessarily that impl trait is RPIT
We have this random `return_type_impl_trait` function to detect if a function returns an RPIT which is used in outlives suggestions, but removing it doesn't actually change any diagnostics. Let's just remove it.
Also, suppress a spurious outlives error from a ReError.
Fixes#114274
Account for macros when suggesting a new let binding
Provide a structured suggestion when the expression comes from a macro expansion:
```
error[E0716]: temporary value dropped while borrowed
--> $DIR/borrowck-let-suggestion.rs:2:17
|
LL | let mut x = vec![1].iter();
| ^^^^^^^ - temporary value is freed at the end of this statement
| |
| creates a temporary value which is freed while still in use
LL |
LL | x.use_mut();
| - borrow later used here
|
= note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider using a `let` binding to create a longer lived value
|
LL ~ let binding = vec![1];
LL ~ let mut x = binding.iter();
|
```
WASI threads, implementation of wasm32-wasi-preview1-threads target
This PR adds a target proposed in https://github.com/rust-lang/compiler-team/issues/574 by `@abrown` and implementation of `std:🧵:spawn` for the target `wasm32-wasi-preview1-threads`
### Tier 3 Target Policy
As tier 3 targets, the new targets are required to adhere to [the tier 3 target policy](https://doc.rust-lang.org/nightly/rustc/target-tier-policy.html#tier-3-target-policy) requirements. This section quotes each requirement in entirety and describes how they are met.
> - 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.)
See [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/pull/112922/files#diff-a48ee9d94f13e12be24eadd08eb47b479c153c340eeea4ef22276d876dfd4f3e).
> - 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.
> - 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.
The target is using the same name for $ARCH=wasm32 and $OS=wasi as existing Rust targets. The suffix `preview1` introduced to accurately set expectations because eventually this target will be deprecated and follows [MCP 607](https://github.com/rust-lang/compiler-team/issues/607). The suffix `threads` indicates that it’s an extension that enables threads to the existing target and it follows [MCP 574](https://github.com/rust-lang/compiler-team/issues/574) which describes the rationale behind introducing a separate target.
> - 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 must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
> - 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.
> - 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.
> - "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.
This PR does not introduce any new dependency.
The new target doesn’t support building host tools.
> 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 full standard library is available for this target as it’s an extension to an existing target that has already supported it.
> 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.
Only manual test running is supported at the moment with some tweaks in the test runner codebase. For build and running tests see [src/doc/rustc/src/platform-support/wasm32-wasi-preview1-threads.md](https://github.com/rust-lang/rust/pull/112922/files#diff-a48ee9d94f13e12be24eadd08eb47b479c153c340eeea4ef22276d876dfd4f3e).
> - 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.
> - 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.
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> - 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.
I acknowledge these requirements and intend to ensure they are met.
Similar to the last commit, it's more of a `Parser`-level concern than a
`TokenCursor`-level concern. And the struct size reductions are nice.
After this change, `TokenCursor` is as minimal as possible (two fields
and two methods) which is nice.
It's more of a `Parser`-level concern than a `TokenCursor`-level
concern. Also, `num_bump_calls` is a more accurate name, because it's
incremented in `Parser::bump`.
Comparing vectors of string parts yields the same result but avoids
unnecessary `join` and potential allocation for resulting `String`.
This code is cold so it's unlikely to have any measurable impact, but
considering but since it's also simpler, why not? :)
Filter out short-lived LLVM diagnostics before they reach the rustc handler
During profiling I saw remark passes being unconditionally enabled: for example `Machine Optimization Remark Emitter`.
The diagnostic remarks enabled by default are [from missed optimizations and opt analyses](https://github.com/rust-lang/rust/pull/113339#discussion_r1259480303). They are created by LLVM, passed to the diagnostic handler on the C++ side, emitted to rust, where they are unpacked, C++ strings are converted to rust, etc.
Then they are discarded in the vast majority of the time (i.e. unless some kind of `-Cremark` has enabled some of these passes' output to be printed).
These unneeded allocations are very short-lived, basically only lasting between the LLVM pass emitting them and the rust handler where they are discarded. So it doesn't hugely impact max-rss, and is only a slight reduction in instruction count (cachegrind reports a reduction between 0.3% and 0.5%) _on linux_. It's possible that targets without `jemalloc` or with a worse allocator, may optimize these less.
It is however significant in the aggregate, looking at the total number of allocated bytes:
- it's the biggest source of allocations according to dhat, on the benchmarks I've tried e.g. `syn` or `cargo`
- allocations on `syn` are reduced by 440MB, 17% (from 2440722647 bytes total, to 2030461328 bytes)
- allocations on `cargo` are reduced by 6.6GB, 19% (from 35371886402 bytes total, to 28723987743 bytes)
Some of these diagnostics objects [are allocated in LLVM](https://github.com/rust-lang/rust/pull/113339#discussion_r1252387484) *before* they're emitted to our diagnostic handler, where they'll be filtered out. So we could remove those in the future, but that will require changing a few LLVM call-sites upstream, so I left a FIXME.
Move doc comment desugaring out of `TokenCursor`.
It's awkward that `TokenCursor` sometimes desugars doc comments on the fly, but usually doesn't.
r? `@petrochenkov`
now that remarks are filtered before cg_llvm's diagnostic handler callback
is called, we don't need to do the filtering post c++-to-rust conversion
of the diagnostic.
this will eliminate many short-lived allocations (e.g. 20% of the memory used
building cargo) when unpacking the diagnostic and converting its various
C++ strings into rust strings, just to be filtered out most of the time.
cleanup: remove pointee types
This can't be merged until the oldest LLVM version we support uses opaque pointers, which will be the case after #114148. (Also note `-Cllvm-args="-opaque-pointers=0"` can technically be used in LLVM 15, though I don't think we should support that configuration.)
I initially hoped this would provide some minor perf win, but in https://github.com/rust-lang/rust/pull/105412#issuecomment-1341224450 it had very little impact, so this is only valuable as a cleanup.
As a followup, this will enable #96242 to be resolved.
r? `@ghost`
`@rustbot` label S-blocked
Since all output characters taken from `BASE_64` are valid UTF8 chars
there is no need to waste cycles on validation.
Even though it's obviously a perf win, I've also used a [benchmark](https://gist.github.com/ttsugriy/e1e63c07927d8f31e71695a9c617bbf3)
on M1 MacBook Air with following results:
```
Running benches/base_n_benchmark.rs (target/release/deps/base_n_benchmark-825fe5895b5c2693)
push_str/old time: [14.670 µs 14.852 µs 15.074 µs]
Performance has regressed.
Found 11 outliers among 100 measurements (11.00%)
4 (4.00%) high mild
7 (7.00%) high severe
push_str/new time: [12.573 µs 12.674 µs 12.801 µs]
Performance has regressed.
Found 11 outliers among 100 measurements (11.00%)
7 (7.00%) high mild
4 (4.00%) high severe
```
[rustc_data_structures][perf] Simplify base_n::push_str.
This minor change removes the need to reverse resulting digits. Since reverse is O(|digit_num|) but bounded by 128, it's unlikely to be a noticeable in practice. At the same time, this code is also a 1 line shorter, so combined with tiny perf win, why not?
I ran https://gist.github.com/ttsugriy/ed14860ef597ab315d4129d5f8adb191 on M1 macbook air and got a small improvement
```
Running benches/base_n_benchmark.rs (target/release/deps/base_n_benchmark-825fe5895b5c2693)
push_str/old time: [14.180 µs 14.313 µs 14.462 µs]
Performance has improved.
Found 5 outliers among 100 measurements (5.00%)
4 (4.00%) high mild
1 (1.00%) high severe
push_str/new time: [13.741 µs 13.839 µs 13.973 µs]
Performance has improved.
Found 8 outliers among 100 measurements (8.00%)
3 (3.00%) high mild
5 (5.00%) high severe
```
Improve diagnostic for wrong borrow on binary operations
This PR improves the diagnostic for wrong borrow on binary operations by suggesting to reborrow on appropriate expressions.
```diff
+ = note: an implementation for `&Foo * &Foo` exist
+ help: consider reborrowing both sides
+ |
+ LL | let _ = &*ref_mut_foo * &*ref_mut_foo;
+ | ++ ++
```
Fixes https://github.com/rust-lang/rust/issues/109352
coverage: Replace `ExpressionOperandId` with enum `Operand`
*This is one step in my larger coverage refactoring ambitions described at <https://github.com/rust-lang/compiler-team/issues/645>.*
LLVM coverage has a concept of “mapping expressions” that allow a span's execution count to be computed as a simple arithmetic expression over other counters/expressions, instead of requiring a dedicated physical counter for every control-flow branch.
These expressions have an operator (`+` or `-`) and two operands. Operands are currently represented as `ExpressionOperandId`, which wraps a `u32` with the following semantics:
- 0 represents a special counter that always has a value of zero
- Values ascending from 1 represent counter IDs
- Values descending from `u32::MAX` represent the IDs of other expressions
---
This change replaces that whole `ExpressionOperandId` scheme with a simple enum that explicitly distinguishes between the three cases.
This lets us remove a lot of fiddly code for dealing with the different operand kinds:
- Previously it was only possible to distinguish between counter-ID operands and expression-ID operands by comparing the operand ID with the total number of counters in a function. This is unnecessary now that the enum distinguishes them explicitly.
- There's no need for expression IDs to descend from `u32::MAX` and then get translated into zero-based indices in certain places. Now that they ascend from zero, they can be used as indices directly.
- There's no need to reserve ID number 0 for the special zero operand, since it can just have its own variant in the enum, so counter IDs can count up from 0.
(Making counter IDs ascend from 0 also lets us fix an off-by-one error in the query for counting the total number of counters, which would cause LLVM to emit an extra unused counter for every instrumented function.)
---
This PR may be easiest to review as individual patches, since that breaks it up into clearly distinct parts:
- Replace a `u32` wrapper with an explicit enum, without changing the semantics of the underlying IDs being stored.
- Change the numbering scheme used by `Operand::Expression` to make expression IDs ascend from 0 (instead of descending from `u32::MAX`).
- Change the numbering scheme used by `Operand::Counter` to make counter IDs ascend from 0 (instead of ascending from 1).
[rustc_data_structures] Simplify SortedMap::insert.
It looks like current usage of `swap` is aimed at achieving what `std::mem::replace` does but more concisely and idiomatically.
Operand types are now tracked explicitly, so there is no need to reserve ID 0
for the special always-zero counter.
As part of the renumbering, this change fixes an off-by-one error in the way
counters were counted by the `coverageinfo` query. As a result, functions
should now have exactly the number of counters they actually need, instead of
always having an extra counter that is never used.
Operand types are now tracked explicitly, so there is no need for expression
IDs to avoid counter IDs by descending from `u32::MAX`. Instead they can just
count up from 0, and can be used directly as indices when necessary.
Because the three kinds of operand are now distinguished explicitly, we no
longer need fiddly code to disambiguate counter IDs and expression IDs based on
the total number of counters/expressions in a function.
This does increase the size of operands from 4 bytes to 8 bytes, but that
shouldn't be a big deal since they are mostly stored inside boxed structures,
and the current coverage code is not particularly size-optimized anyway.
The actual motivation here is to prevent `rustfmt` from suddenly reformatting
these enum variants onto a single line, when they become slightly shorter in
the future.
But there's no harm in adding some helpful documentation at the same time.
Detect trait upcasting through struct tail unsizing in new solver select
Oops, we were able to hide trait upcasting behind a parent unsize goal that evaluated to `Certainty::Yes`. Let's do rematching for `Certainty::Yes` unsize goals with `BuiltinImplSource::Misc` sources (corresponding to all of the other unsize rules) to make sure we end up selecting any nested goals which may be satisfied via `BuiltinImplSource::TraitUpcasting` or `::TupleUnsizing`.
r? ``@lcnr``
Update lexer emoji diagnostics to Unicode 15.0
This replaces the `unic-emoji-char` dep tree (which hasn't been updated for a while) with `unicode-properties` crate which contains Unicode 15.0 data.
Improves diagnostics for added emoji characters in recent years. (See tests).
cc #101840
cc ``@Manishearth``
This minor change removes the need to reverse resulting digits.
Since reverse is O(|digit_num|) but bounded by 128, it's unlikely
to be a noticeable in practice. At the same time, this code is
also a 1 line shorter, so combined with tiny perf win, why not?
I ran https://gist.github.com/ttsugriy/ed14860ef597ab315d4129d5f8adb191
on M1 macbook air and got a small improvement
```
Running benches/base_n_benchmark.rs (target/release/deps/base_n_benchmark-825fe5895b5c2693)
push_str/old time: [14.180 µs 14.313 µs 14.462 µs]
Performance has improved.
Found 5 outliers among 100 measurements (5.00%)
4 (4.00%) high mild
1 (1.00%) high severe
push_str/new time: [13.741 µs 13.839 µs 13.973 µs]
Performance has improved.
Found 8 outliers among 100 measurements (8.00%)
3 (3.00%) high mild
5 (5.00%) high severe
```
Map RPITIT's opaque type bounds back from projections to opaques
An RPITIT in a program's AST is eventually translated into both a projection GAT and an opaque. The opaque is used for default trait methods, like:
```
trait Foo {
fn bar() -> impl Sized { 0i32 }
}
```
The item bounds for both the projection and opaque are identical, and both have a *projection* self ty. This is mostly okay, since we can normalize this projection within the default trait method body to the opaque, but it does two things:
1. it leads to bugs in places where we don't normalize item bounds, like `deduce_future_output_from_obligations`
2. it leads to extra match arms that are both suspicious looking and also easy to miss
This PR maps the opaque type bounds of the RPITIT's *opaque* back to the opaque's self type to avoid this quirk. Then we can fix the UI test for #108304 (1.) and also remove a bunch of match arms (2.).
Fixes#108304
r? `@spastorino`
Check lazy type aliases for well-formedness
Previously we didn't check if `T: Mul` holds given lazy `type Alias<T> = <T as Mul>::Output;`.
Now we do. It only makes sense.
`@rustbot` label F-lazy_type_alias
r? `@oli-obk`
This function has some shared code for the thin LTO and fat LTO cases,
but those cases have so little in common that it's actually clearer to
treat them fully separately.
PR #112946 tweaked the naming of LLVM threads, but messed things up
slightly, resulting in threads on Windows having names like `optimize
module {} regex.f10ba03eb5ec7975-cgu.0`.
This commit removes the extraneous `{} `.
The main loop has a *very* complex condition, which includes two
mentions of `codegen_state`. The body of the loop then immediately
switches on the `codegen_state`.
I find it easier to understand if it's a `loop` and we check for exit
conditions after switching on `codegen_state`. We end up with a tiny bit
of code duplication, but it's clear that (a) we never exit in the
`Ongoing` case, (b) we exit in the `Completed` state only if several
things are true (and there's interaction with LTO there), and (c) we
exit in the `Aborted` state if a couple of things are true. Also, the
exit conditions are all simple conjunctions.
