Disallow shebang in `--cfg` and `--check-cfg` arguments
This PR is similar to https://github.com/rust-lang/rust/issues/146130, where we disallowed frontmatter in `--cfg` and `--check-cfg` arguments. While fixing the other one we also discovered that shebang `#!/usr/bin/shebang` are currently also allowed in `--cfg` and `--check-cfg` arguments.
Allowing shebang in them (which are just ignored) was never intended, this PR fixes that by not stripping shebang for `--cfg` and `--check-cfg` arguments.
This is technically a breaking-change, although I don't expect anyone to actually rely on this unintended behavior.
Fixes https://github.com/rust-lang/rust/issues/146130#issuecomment-3246299499
r? fmease
Suggest bounds in more cases, accounting for type parameters referenced in predicate
Use a `ty::Visitor` to see if the failed predicate references a type parameter. If it does, then we only suggest adding a bound to an (associated) item only if the referenced parameter is present in its generics.
Provide adding bound suggestion in trait and impl associated functions in cases we previously weren't:
```
error[E0277]: `?` couldn't convert the error to `ApplicationError`
--> $DIR/suggest-complex-bound-on-method.rs:18:16
|
LL | t.run()?;
| -----^ the trait `From<<T as Trait>::Error>` is not implemented for `ApplicationError`
| |
| this can't be annotated with `?` because it has type `Result<_, <T as Trait>::Error>`
|
note: `ApplicationError` needs to implement `From<<T as Trait>::Error>`
--> $DIR/suggest-complex-bound-on-method.rs:12:1
|
LL | enum ApplicationError {
| ^^^^^^^^^^^^^^^^^^^^^
= note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
|
LL | fn thing<T: Trait>(&self, t: T) -> Result<(), ApplicationError> where ApplicationError: From<<T as Trait>::Error> {
| +++++++++++++++++++++++++++++++++++++++++++++++++
```
Fixrust-lang/rust#144734.
Ensure that `--html-after-content` option is used to check `scrape_examples_ice` rustdoc GUI test
Follow-up of https://github.com/rust-lang/rust/pull/146091.
This test ensures that the spans are correctly handled when a "local source file" is not the first in the file list. To ensure it's actually what's tested, this test checks that the option is actually used by adding an element.
r? `@lolbinarycat`
Add `__isPlatformVersionAtLeast` and `__isOSVersionAtLeast` symbols
## Motivation
When Objective-C code uses ```@available(...)`,`` Clang inserts a call to [`__isPlatformVersionAtLeast`](https://github.com/llvm/llvm-project/blob/llvmorg-20.1.0/compiler-rt/lib/builtins/os_version_check.c#L276) (`__isOSVersionAtLeast` in older Clang versions). These symbols not being available sometimes ends up causing linker errors. See the new test `tests/run-make/apple-c-available-links` for a minimal reproducer.
The workaround is to link `libclang_rt.osx.a`, see e.g. https://github.com/alexcrichton/curl-rust/issues/279. But that's very difficult for users to figure out (and the backreferences to that issue indicates that people are still running into this in their own projects every so often).
For another recent example, this is preventing `rustc` from using LLVM assertions on macOS, see https://github.com/rust-lang/rust/pull/62592#issuecomment-510670657 and https://github.com/rust-lang/rust/pull/134275#issuecomment-2543067830.
It is also a blocker for [setting the correct minimum OS version in `cc-rs`](https://github.com/rust-lang/rust/issues/136113), since fixing this in `cc-rs` might end up introducing linker errors in places where we weren't before (by default, if using e.g. ```@available(macos`` 10.15, *)`, the symbol usually happens to be left out, since `clang` defaults to compiling for the host macOS version, and thus things _seem_ to work - but the availability check actually compiles down to nothing, which is a huge correctness footgun for running on older OSes).
(My super secret evil agenda is also to expose some variant of ```@available``` in Rust's `std` after https://github.com/rust-lang/rfcs/pull/3750 progresses further, will probably file an ACP for this later. But I believe this PR has value regardless of those future plans, since we'd be making C/Objective-C/Swift interop easier).
## Solution
Implement `__isPlatformVersionAtLeast` and `__isOSVersionAtLeast` as part of the "public ABI" that `std` exposes.
**This is insta-stable**, in the same sense that additions to `compiler-builtins` are insta-stable, though the availability of these symbols can probably be considered a "quality of implementation" detail rather than a stable promise.
I originally proposed to implement this in `compiler-builtins`, see https://github.com/rust-lang/compiler-builtins/pull/794, but we discussed moving it to `std` instead ([Zulip thread](https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Provide.20.60__isPlatformVersionAtLeast.60.20in.20.60std.60.3F/with/507880717)), which makes the implementation substantially simpler, and we avoid gnarly issues with requiring the user to link `libSystem.dylib` (since `std` unconditionally does that).
Note that this does not solve the linker errors for (pure) `#![no_std]` users, but that's _probably_ fine, if you are using ```@available``` to test the OS version on Apple platforms, you're likely also using `std` (and it is still possible to work around by linking `libclang_rt.*.a`).
A thing to note about the implementation, I've choosen to stray a bit from LLVM's upstream implementation, and not use `_availability_version_check` since [it has problems when compiling with an older SDK](https://github.com/llvm/llvm-project/issues/64227). Instead, we use `sysctl kern.osproductversion` when available to still avoid the costly PList lookup in most cases, but still with a fall back to the PList lookup when that is not available (with the PList fallback being is similar to LLVM's implementation).
## Testing
Apple has a lot of different "modes" that they can run binaries in, which can be a bit difficult to find your bearings in, but I've tried to be as thorough as I could in testing them all.
Tested using roughly the equivalent of `./x test library/std -- platform_version` on the following configurations:
- macOS 14.7.3 on a Macbook Pro M2
- `aarch64-apple-darwin`
- `x86_64-apple-darwin` (under Rosetta)
- `aarch64-apple-ios-macabi`
- `x86_64-apple-ios-macabi` (under Rosetta)
- `aarch64-apple-ios` (using Xcode's "Designed for iPad" setting)
- `aarch64-apple-ios-sim` (in iOS Simulator, as iPhone with iOS 17.5)
- `aarch64-apple-ios-sim` (in iOS Simulator, as iPad with iOS 18.2)
- `aarch64-apple-tvos-sim` (in tvOS Simulator)
- `aarch64-apple-watchos-sim` (in watchOS Simulator)
- `aarch64-apple-ios-sim` (in visionOS simulator, using Xcode's "Designed for iPad" setting)
- `aarch64-apple-visionos-sim` (in visionOS Simulator)
- macOS 15.3.1 VM
- `aarch64-apple-darwin`
- `aarch64-apple-ios-macabi`
- macOS 10.12.6 on an Intel Macbook from 2013
- `x86_64-apple-darwin`
- `i686-apple-darwin`
- `x86_64-apple-ios` (in iOS Simulator)
- iOS 9.3.6 on a 1st generation iPad Mini
- `armv7-apple-ios` with an older compiler
Along with manually inspecting the output of `version_from_sysctl()` and `version_from_plist()`, and verifying that they actually match what's expected.
I believe the only real omissions here would be:
- `aarch64-apple-ios` on a newer iPhone that has `sysctl` available (iOS 11.4 or above).
- `aarch64-apple-ios` on a Vision Pro using Xcode's "Designed for iPad" setting.
But I don't have the hardware available to test those.
``@rustbot`` label O-apple A-linkage -T-compiler -A-meta -A-run-make
try-job: aarch64-apple
Suggest parentheses when `match` or `if` expression in binop is parsed as statement
```
error[E0308]: mismatched types
--> $DIR/expr-as-stmt.rs:81:5
|
LL | match () { _ => true } && match () { _ => true };
| ^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found `bool`
|
help: parentheses are required to parse this as an expression
|
LL | (match () { _ => true }) && match () { _ => true };
| + +
```
Address the common case from rust-lang/rust#88727. The original parse error is still outstanding, but the cases brought up in the thread are resolved.
fix ICE when suggesting `::new`
fixes https://github.com/rust-lang/rust/issues/146174
This code suggests to write `Foo::new(...)` when the user writes `Foo(...)` or `Foo { ... }` and the constructor is private, where `new` is some associated function that returns `Self`.
When checking that the return type of `new` is `Self`, we need to instantiate the parameters of `new` with infer vars, so we don't end up with a type like `Box<$param(0)>` in a context that doesn't have any parameters. But then we can't use `normalize_erasing_late_bound_regions` anymore because that goes though a query that can't deal with infer vars.
Since this is diagnostic-only code that is supposed to check for exactly `-> Self`, I think it's fine to just skip normalizing here, especially since The Correct Way<sup>TM</sup> would involve a probe and make this code even more complicated.
Also, the code here does almost the same thing, and these suggestions can probably be unified in the future: https://github.com/rust-lang/rust/blob/4ca8078d37c53ee4ff8fb32b4453b915116f25b8/compiler/rustc_hir_typeck/src/method/suggest.rs#L2123-L2129
r? ````@compiler-errors````
cc ````@Qelxiros```` -- this should unblock https://github.com/rust-lang/rust/pull/144420
Fix LoongArch C function ABI when passing/returning structs containing floats
Similar to RISC-V, LoongArch passes structs containing only one or two floats (or a float–integer pair) in registers, as long as each element fits into a single corresponding register. Before this PR, Rust did not check the actual offset of the second float or integer; instead, it assumed the standard offset based on the default alignment. However, since the offset can be affected by `#[repr(align(N))]` and `#[repr(packed)]`, this led to miscompilations (see rust-lang/rust#145692). This PR fixes the issue by explicitly specifying the offset for the remainder of the cast.
Sanitizers target modificators
Depends on bool flag fix: https://github.com/rust-lang/rust/pull/138483.
Some sanitizers need to be target modifiers, and some do not. For now, we should mark all sanitizers as target modifiers except for these: AddressSanitizer, LeakSanitizer
For kCFI, the helper flag -Zsanitizer-cfi-normalize-integers should also be a target modifier.
Many test errors was with sanizer flags inconsistent with std deps. Tests are fixed with `-C unsafe-allow-abi-mismatch`.
fix(rustdoc): match rustc `--emit` precedence
Resolvesrust-lang/rust#141664
This changes rustdoc's `--emit` to allow only one instance of each type, regardless of the actual data that `--emit` carries. This matches rustc's `--emit` behavior.
As of the writing, only `dep-info` emit type carries extra data.
Disallow frontmatter in `--cfg` and `--check-cfg` arguments
This PR disallows the frontmatter syntax in `--cfg` and `--check-cfg` arguments.
Fixes https://github.com/rust-lang/rust/issues/146130
r? fmease
Allow `inline(always)` with a target feature behind a unstable feature `target_feature_inline_always`.
Rather than adding the inline always attribute to the function definition, we add it to the callsite. We can then check that the target features match and that the call would be safe to inline. If the function isn't inlined due to a mismatch, we emit a warning informing the user that the function can't be inlined due to the target feature mismatch.
See tracking issue rust-lang/rust#145574
On unused binding or binding not present in all patterns, suggest potential typo of unit struct/variant or const
When encountering an or-pattern with a binding not available in all patterns, look for consts and unit struct/variants that have similar names as the binding to detect typos.
```
error[E0408]: variable `Ban` is not bound in all patterns
--> $DIR/binding-typo.rs:22:9
|
LL | (Foo, _) | (Ban, Foo) => {}
| ^^^^^^^^ --- variable not in all patterns
| |
| pattern doesn't bind `Ban`
|
help: you might have meant to use the similarly named unit variant `Bar`
|
LL - (Foo, _) | (Ban, Foo) => {}
LL + (Foo, _) | (Bar, Foo) => {}
|
```
For items that are not in the immedate scope, suggest the full path for them:
```
error[E0408]: variable `Non` is not bound in all patterns
--> $DIR/binding-typo-2.rs:51:16
|
LL | (Non | Some(_))=> {}
| --- ^^^^^^^ pattern doesn't bind `Non`
| |
| variable not in all patterns
|
help: you might have meant to use the similarly named unit variant `None`
|
LL - (Non | Some(_))=> {}
LL + (core::option::Option::None | Some(_))=> {}
|
```
When encountering a typo in a pattern that gets interpreted as an unused binding, look for unit struct/variant of the same type as the binding:
```
error: unused variable: `Non`
--> $DIR/binding-typo-2.rs:36:9
|
LL | Non => {}
| ^^^
|
help: if this is intentional, prefix it with an underscore
|
LL | _Non => {}
| +
help: you might have meant to pattern match on the similarly named variant `None`
|
LL - Non => {}
LL + std::prelude::v1::None => {}
|
```
Suggest constant on unused binding in a pattern
```
error: unused variable: `Batery`
--> $DIR/binding-typo-2.rs:110:9
|
LL | Batery => {}
| ^^^^^^
|
help: if this is intentional, prefix it with an underscore
|
LL | _Batery => {}
| +
help: you might have meant to pattern match on the similarly named constant `Battery`
|
LL | Battery => {}
| +
```
Fixrust-lang/rust#51976.
fix drop scope for `super let` bindings within `if let`
Fixesrust-lang/rust#145328 by making non-lifetime-extended `super let` reuse the logic used to compute drop scopes for non-lifetime-extended temporaries.
Also fixesrust-lang/rust#145374, which regressed due to rust-lang/rust#143376 introducing `if let`-like scopes for match arms with guards.
Tracking issue for `super let`: rust-lang/rust#139076
This is a regression fix / breaking change for macros stably exposing `super let`, including `pin!` and `format_args!`.
Nominating to be discussed alongside rust-lang/rust#145328: ```@rustbot``` label +I-lang-nominated +I-libs-api-nominated
a more general version of https://github.com/rust-lang/rust/pull/146080.
after a bit of hacking in [`fluent.rs`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_fluent_macro/src/fluent.rs), i discovered that i'm not the only one that is bad at following guidelines 😅. this pr lowercases the first letter of all the error messages in the codebase.
(i did not change things that are traditionally uppercased such as _MIR_, _ABI_ or _C_)
i think it's reasonable to run a `@bors try` so all the test suite is checked, as i cannot run some of the tests on my machine. i double checked (and replaced manually) all the old error messages, but better be safe than sorry.
in the future i will try to add a check in `x test tidy` that errors if an error message starts with an uppercase letter.
fix(lexer): Only allow horizontal whitespace in frontmatter
In writing up the reference for frontmatter, I realized that we probably
shouldn't be accepting Unicode Line Ending characters between the code
fence and infostring or trailing after the infostring or a code fence.
In digging into the unicode specification we use for Whitespace, it
divides it up into categories, so I'm deferring to what it says for
horizontal whitespace for what should be used within a line.
Note, I am leaving out support for Unicode Default Ignorable characters.
I figure that can be discussed outside of this change within the
reference and tracking issue.
Fixesrust-lang/rust#145971
Frontmatter tracking issue: rust-lang/rust#136889
Constify conversion traits (part 1)
This is the first part of rust-lang/rust#144289 being split into smaller pieces. It adds/moves constness of several traits under the `const_convert` feature:
* `From`
* `Into`
* `TryFrom`
* `TryInto`
* `FromStr`
* `AsRef`
* `AsMut`
* `Borrow`
* `BorrowMut`
* `Deref`
* `DerefMut`
There are a few methods that are intrinsically tied to these traits which I've included in the feature. Particularly, those which are wrappers over `AsRef`:
* `ByteStr::new` (unstable under `bstr` feature)
* `OsStr::new`
* `Path::new`
Those which directly use `Into`:
* `Result::into_ok`
* `Result::into_err`
And those which use `Deref` and `DerefMut`:
* `Pin::as_ref`
* `Pin::as_mut`
* `Pin::as_deref_mut`
* `Option::as_deref`
* `Option::as_deref_mut`
* `Result::as_deref`
* `Result::as_deref_mut`
(note: the `Option` and `Result` methods were suggested by ``@npmccallum`` initially as rust-lang/rust#146101)
The parts which are missing from this PR are:
* Anything that involves heap-allocated types
* Making any method const than the ones listed above
* Anything that could rely on the above, *or* could rely on system-specific code for `OsStr` or `Path` (note: this mostly makes these methods useless since `str` doesn't implement `AsRef<OsStr>` yet, but it's better to track the method for now and add impls later, IMHO)
r? ``@tgross35`` (who mostly already reviewed this)
Change rustdoc's `--emit` to allow only one instance of each type,
regardless of the actual data that `--emit` carries.
This matches rustc's `--emit` behavior.
As of the writing, only `dep-info` emit type carries extra data.
See <https://github.com/rust-lang/rust/issues/141664>
fix rustdoc `render_call_locations` panicking because of default span `DUMMY_SP` pointing at non local-source file
fixes https://github.com/rust-lang/rust/issues/144752
related to/builds on https://github.com/rust-lang/rust/pull/145008
bevy still crashes in the same way as rust-lang/rust#144752 when building docs on nightly, and from what I can tell the cause seems to be the following (copied from zulip [#t-rustdoc > docs on nightly with example scrapes crash](https://rust-lang.zulipchat.com/#narrow/channel/266220-t-rustdoc/topic/docs.20on.20nightly.20with.20example.20scrapes.20crash)):
> render_call_locations tries to [find](https://github.com/rust-lang/rust/blob/84a17470220e7adf249b18d7c0178dfbede89462/src/librustdoc/html/render/mod.rs#L2816) the source span of a call to add as an example, but the example files are never actually in the source map from what I can tell, and so it falls back to the default span, which points at the first file in the source map.
> Now, the issue that guillaume mentions [here](https://github.com/rust-lang/rust/pull/145008) adds new files to the source map in order to get them into the dep info, and that leads to some files, namely docs-rs/trait-tags.html in the case of bevy because it's added with --html-after-content, being added before any source files, so then the default span points at them, and when href_from_span tries to find the [source file](https://github.com/rust-lang/rust/blob/84a17470220e7adf249b18d7c0178dfbede89462/src/librustdoc/html/render/context.rs#L368) corresponding to the span, the file doesn't belong to local_sources, and it short circuits.
> This can be fixed by just not using DUMMY_SP as the default span and calculating, for example, the crates root source file as the span, because I'm not entirely sure what the href from that span is actually used for; it's not what links to the example in the end.
> I think the proper way of fixing this would be to make sure the example files are part of the local_sources or at least the source map, but I don't know nearly enough about rust internals to be able to figure out how to fix that.
I've included a test that's mostly copied from rust-lang/rust#145008's test with the addition of `--html-after-content after.html` in the `RUSTDOCFLAGS`, which panics on master in conjunction with the `-Zrustdoc-scrape-examples` cargo flag.
cc `@GuillaumeGomez`
Add compiler error when trying to use concat metavar expr in repetitions
## Disclaimer
This is my first PR to rust, so if I missed/could improve something about this PR, please excuse and tell me!
## The improvement
The [metavar_expr_concat feature](https://github.com/rust-lang/rust/issues/124225) currently does not seem to support nested repetitions, and throws an ICE without much explanation if the relevant code path is hit.
This PR adds a draft compiler error that attempts to explain the issue. I am not 100% sure what all the ways of triggering this error are, so the message is currently pretty generic, please do correct me if there's something wrong with it or it could be improved.
Thank you for you time!
Fixesrust-lang/rust#140479.
add span to struct pattern rest (..)
Struct pattern rest (`..`) did not retain span information compared to normal fields. This patch adds span information for it.
The motivation of this patch comes from when I implemented this PR for Clippy: https://github.com/rust-lang/rust-clippy/pull/15000#discussion_r2134145163
It is possible to get the span of the Et cetera in a bit roundabout way, but I thought this would be nicer.
stabilize c-style varargs for sysv64, win64, efiapi, aapcs
This has been split up so the PR now only contains the extended_varargs_abi_support stabilization; "system" has been moved to https://github.com/rust-lang/rust/pull/145954.
**Previous (combined) PR description:**
This stabilizes extern block declarations of variadic functions with the system, sysv64, win64, efiapi, aapcs ABIs. This corresponds to the extended_varargs_abi_support and extern_system_varargs feature gates.
The feature gates were split up since it seemed like there might be further discussion needed for what exactly "system" ABI variadic functions should do, but a [consensus](https://github.com/rust-lang/rust/issues/136946#issuecomment-2967847553) has meanwhile been reached: they shall behave like "C" functions. IOW, the ABI of a "system" function is (bold part is new in this PR):
- "stdcall" for win32 targets **for non-variadic functions**
- "C" for everything else
This had been previously stabilized *without FCP* in https://github.com/rust-lang/rust/pull/116161, which got reverted in https://github.com/rust-lang/rust/pull/136897. There was also a "fun" race condition involved with the system ABI being [added](https://github.com/rust-lang/rust/pull/119587) to the list of variadic-supporting ABIs between the creation and merge of rust-lang/rust#116161.
There was a question raised [here](https://github.com/rust-lang/rust/pull/116161#issuecomment-1983829513) whether t-lang even needs to be involved for a change like this. Not sure if that has meanwhile been clarified? The behavior of the "system" ABI (a Rust-specific ABI) definitely feels like t-lang territory to me.
Fixesrust-lang/rust#100189
Cc `@rust-lang/lang`
# Stabilization report
> ## General design
> ### What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?
AFAIK there is no RFC. The tracking issues are
- https://github.com/rust-lang/rust/issues/100189
- https://github.com/rust-lang/rust/issues/136946
> ### What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.
The only controversial point is whether "system" ABI functions should support variadics.
- Pro: This allows crates like windows-rs to consistently use "system", see e.g. https://github.com/microsoft/windows-rs/issues/3626.
- Cons: `@workingjubilee` had some implementation concerns, but I think those have been [resolved](https://github.com/rust-lang/rust/issues/136946#issuecomment-2967847553). EDIT: turns out Jubilee still has concerns (she mentioned that in a DM); I'll let her express those.
Note that "system" is already a magic ABI we introduced to "do the right thing". This just makes it do the right thing in more cases. In particular, it means that on Windows one can almost always just do
```rust
extern "system" {
// put all the things here
}
```
and it'll do the right thing, rather than having to split imports into non-varargs and varargs, with the varargs in a separate `extern "C"` block (and risking accidentally putting a non-vararg there).
(I am saying "almost" always because some Windows API functions actually use cdecl, not stdcall, on x86. Those of course need to go in `extern "C"` blocks.)
> ### Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those?
Actually defining variadic functions in Rust remains unstable, under the [c_variadic feature gate](https://github.com/rust-lang/rust/issues/44930).
> ## Has a Call for Testing period been conducted? If so, what feedback was received?
>
> Does any OSS nightly users use this feature? For instance, a useful indication might be "search <grep.app> for `#![feature(FEATURE_NAME)]` and had `N` results".
There was no call for testing.
A search brings up https://github.com/rust-osdev/uefi-rs/blob/main/uefi-raw/src/table/boot.rs using this for "efiapi". This doesn't seem widely used, but it is an "obvious" gap in our support for c-variadics.
> ## Implementation quality
All rustc does here is forward the ABI to LLVM so there's lot a lot to say here...
> ### Summarize the major parts of the implementation and provide links into the code (or to PRs)
>
> An example for async closures: <https://rustc-dev-guide.rust-lang.org/coroutine-closures.html>.
The check for allowed variadic ABIs is [here](https://github.com/rust-lang/rust/blob/9c870d30e2d6434c9e9a004b450c5ccffdf3d844/compiler/rustc_hir_analysis/src/lib.rs#L109-L126).
The special handling of "system" is [here](https://github.com/rust-lang/rust/blob/c24914ec8329b22ec7bcaa6ab534a784b2bd8ab9/compiler/rustc_target/src/spec/abi_map.rs#L82-L85).
> ### Summarize existing test coverage of this feature
>
> Consider what the "edges" of this feature are. We're particularly interested in seeing tests that assure us about exactly what nearby things we're not stabilizing.
>
> Within each test, include a comment at the top describing the purpose of the test and what set of invariants it intends to demonstrate. This is a great help to those reviewing the tests at stabilization time.
>
> - What does the test coverage landscape for this feature look like?
> - Tests for compiler errors when you use the feature wrongly or make mistakes?
> - Tests for the feature itself:
> - Limits of the feature (so failing compilation)
> - Exercises of edge cases of the feature
> - Tests that checks the feature works as expected (where applicable, `//@ run-pass`).
> - Are there any intentional gaps in test coverage?
>
> Link to test folders or individual tests (ui/codegen/assembly/run-make tests, etc.).
Prior PRs add a codegen test for all ABIs and tests actually calling extern variadic functions for sysv64 and win64:
- https://github.com/rust-lang/rust/pull/144359
- https://github.com/rust-lang/rust/pull/144379
We don't have a way of executing uefi target code in the test suite, so it's unclear how to fully test efiapi. aapcs could probably be done? (But note that we have hardly an such actually-calling-functions tests for ABI things, we almost entirely rely on codegen tests.)
The test ensuring that we do *not* stabilize *defining* c-variadic functions is `tests/ui/feature-gates/feature-gate-c_variadic.rs`.
> ### What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?
None that I am aware of.
> ### What FIXMEs are still in the code for that feature and why is it ok to leave them there?
None that I am aware of.
> ### Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
`@Soveu` added sysv64, win64, efiapi, aapcs to the list of ABIs that allow variadics, `@beepster4096` added system. `@workingjubilee` recently refactored the ABI handling in the compiler, also affecting this feature.
> ### Which tools need to be adjusted to support this feature. Has this work been done?
>
> Consider rustdoc, clippy, rust-analyzer, rustfmt, rustup, docs.rs.
Maybe RA needs to be taught about the new allowed ABIs? No idea how precisely they mirror what exactly rustc accepts and rejects here.
> ## Type system and execution rules
> ### What compilation-time checks are done that are needed to prevent undefined behavior?
>
> (Be sure to link to tests demonstrating that these tests are being done.)
Nothing new here, this just expands the existing support for calling variadic functions to more ABIs.
> ### Does the feature's implementation need checks to prevent UB or is it sound by default and needs opt in in places to perform the dangerous/unsafe operations? If it is not sound by default, what is the rationale?
Nothing new here, this just expands the existing support for calling variadic functions to more ABIs.
> ### Can users use this feature to introduce undefined behavior, or use this feature to break the abstraction of Rust and expose the underlying assembly-level implementation? (Describe.)
Nothing new here, this just expands the existing support for calling variadic functions to more ABIs.
> ### What updates are needed to the reference/specification? (link to PRs when they exist)
- https://github.com/rust-lang/reference/pull/1936
> ## Common interactions
> ### Does this feature introduce new expressions and can they produce temporaries? What are the lifetimes of those temporaries?
No.
> ### What other unstable features may be exposed by this feature?
None.
add test against crashing with --html-after-content file
correctly add --html-after-content to env not args
formatting fix for rustdoc-call-locations-after-content/rmake.rs
Use local crate source file as default span in `render_call_locations`
- avoids unwrapping the first file added to the source map as a local file in
`href_from_span`
move test to tests/rustdoc-gui, rename to scrape_examples_ice
test link is correct
use rustdocflags, rename path in example, track lock file
factor out duplicate function calls
use compile-flags to make sure the after.html file is actually included in the rustdoc call
fix goml go-to path
increment assert-count in sidebar-source-code.goml
adjust crate-search width in search-result-display.goml
renamed Bar in scrape_examples_ice test
make crate name shorter ..
`-Znext-solver`: support non-defining uses in closures
Cleaned up version of rust-lang/rust#139587, finishing the implementation of https://github.com/rust-lang/types-team/issues/129. This does not affect stable. The reasoning for why this is the case is subtle however.
## What does it do
We split `do_mir_borrowck` into `borrowck_collect_region_constraints` and `borrowck_check_region_constraints`, where `borrowck_collect_region_constraints` returns an enormous `CollectRegionConstraintsResult` struct which contains all the relevant data to actually handle opaque type uses and to check the region constraints later on.
`query mir_borrowck` now simply calls `BorrowCheckRootCtxt::do_mir_borrowck` which starts by iterating over all nested bodies of the current function - visiting nested bodies before their parents - and computing their `CollectRegionConstraintsResult`.
After we've collected all constraints it's time to actually compute the concrete types for the opaques defined by this function. With this PR we now compute the concrete types of opaques for each body before using them to check the non-defining uses of any of them.
After we've computed the concrete types by using all bodies, we use `apply_computed_concrete_opaque_types` for each body to constrain non-defining uses, before finally finishing with `borrowck_check_region_constraints`. We always visit nested bodies before their parents when doing this.
## `ClosureRegionRequirements`
As we only call `borrowck_collect_region_constraints` for nested bodies before type checking the parent, we can't simply use the final `ClosureRegionRequirements` of the nested body during MIR type check. We instead track that we need to apply these requirements in `deferred_closure_requirements`.
We now manually apply the final closure requirements to each body after handling opaque types.
This works, except that we may need the region constraints of nested bodies to successfully define an opaque type in the parent. This is handled by using a new `fn compute_closure_requirements_modulo_opaques` which duplicates region checking - while ignoring any errors - before we've added the constraints from `apply_computed_concrete_opaque_types`. This is necessary for a lot of async tests, as pretty much the entire function is inside of an async block while the opaque type gets defined in the parent.
As an performance optimization we only use `fn compute_closure_requirements_modulo_opaques` in case the nested body actually depends on any opaque types. Otherwise we eagerly call `borrowck_check_region_constraints` and apply the final closure region requirements right away.
## Impact on stable code
Handling the opaque type uses in the parent function now only uses the closure requirements *modulo opaques*, while it previously also considered member constraints from nested bodies. `External` regions are never valid choice regions. Also, member constraints will never constrain a member region if it is required to be outlived by an external region, as that fails the upper-bound check. https://github.com/rust-lang/rust/blob/564ee219127b796d56f74767366fd359758b97de/compiler/rustc_borrowck/src/region_infer/opaque_types/member_constraints.rs#L90-L96
Member constraints therefore never add constraints for external regions :>
r? `@BoxyUwU`
bors