This reverts commit 7ce620dd7c.
The const-hacks introduces bugs, and they make the code harder to maintain.
Let's wait until we can constify these functions without changing their implementation.
std: optimize `dlsym!` macro and add a test for it
The `dlsym!` macro always ensures that the name string is nul-terminated, so there is no need to perform the check at runtime. Also, acquire loads are generally faster than a load and a barrier, so use them. This is only false in the case where the symbol is missing, but that shouldn't matter too much.
std: make address resolution weirdness local to SGX
Currently, the implementations of `TcpStream::connect` and its cousins take an `io::Result<&SocketAddr>` as argument, which is very weird, as most of them then `?`-try the result immediately to access the actual address. This weirdness is however necessitated by a peculiarity of the SGX networking implementation:
SGX doesn't support DNS resolution but rather accepts hostnames in the same place as socket addresses. So, to make e.g.
```rust
TcpStream::connect("example.com:80")`
```
work, the DNS lookup returns a special error (`NonIpSockAddr`) instead, which contains the hostname being looked up. When `.to_socket_addrs()` fails, the `each_addr` function used to select an address will pass the error to the inner `TcpStream::connect` implementation, which in SGX's case will inspect the error and try recover the hostname from it. If
that succeeds, it continues with the found hostname.
This is pretty obviously a terrible hack and leads to buggy code (for instance, when users use the result of `.to_socket_addrs()` in their own `ToSocketAddrs` implementation to select from a list of possible URLs, the only URL used will be that of the last item tried). Still, without changes to the SGX usercall ABI, it cannot be avoided.
Therefore, this PR aims to minimise the impact of that weirdness and remove it from all non-SGX platforms. The inner `TcpStream::connect`, et al. functions now receive the `ToSocketAddrs` type directly and call `each_addr` (which is moved to `sys::net::connection`) themselves. On SGX, the implementation uses a special `each_addr` which contains the whole pass-hostname-through-error hack.
As well as making the code cleaner, this also opens up the possibility of reusing newly created sockets even if a connection request fails – but I've left that for another PR.
CC `@raoulstrackx`
Weakly export `platform_version` symbols
The symbols `__isPlatformVersionAtLeast` and `__isOSVersionAtLeast`. This should allow linking both `compiler-rt` and `std`, which fixes https://github.com/rust-lang/rust/pull/138944#issuecomment-3266574582.
r? tgross35
CC ``@zmodem,`` could you please verify that this works for you?
Miri: non-deterministic floating point operations in foreign_items
Take 2 of rust-lang/rust#143906. The last 2 commits are what changed compared to the original pr.
Verified the tests using (fish shell):
```fish
env MIRIFLAGS="-Zmiri-max-extra-rounding-error -Zmiri-many-seeds" ./x miri --no-fail-fast std core coretests -- f32 f64
```
r? `@RalfJung`
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
std: Implement WASIp2-specific stdio routines
This commit is an extension of rust-lang/rust#145944 but applied to stdio specifically. The stdio routines are updated away from WASIp1 APIs to using WASIp2 APIs natively. The end goal is to eventually drop the dependency on WASIp1 APIs in the standard library entirely in favor of exclusively depending on WASIp2.
This commit is an extension of previous libstd support but applied to stdio
specifically. The stdio routines are updated away from WASIp1 APIs to using
WASIp2 APIs natively. The end goal is to eventually drop the dependency on
WASIp1 APIs in the standard library entirely in favor of exclusively depending
on WASIp2.
Implement Integer funnel shifts
Tracking issue: rust-lang/rust#145686
ACP: https://github.com/rust-lang/libs-team/issues/642
This implements funnel shifts on primitive integer types. Implements this for cg_llvm, with a fallback impl for everything else
Thanks `@folkertdev` for the fixes and tests
cc `@rust-lang/libs-api`
Adds the following items under the `read_buf_at` feature:
- `std::os::unix::fs::FileExt::read_buf_at`
- `std::os::unix::fs::FileExt::read_buf_exact_at`
- `std::os::windows::fs::FileExt::seek_read_buf`
* Ensure nul-termination of the symbol name at compile-time
* Use an acquire load instead of a relaxed load and acquire fence
* Properly use `unsafe` and add safety comments
* Add tests
std: Start supporting WASIp2 natively
This commit is the start of an effort to support WASIp2 natively in the
standard library. Before this commit the `wasm32-wasip2` target behaved
exactly like `wasm32-wasip1` target by importing APIs from the core wasm
module `wasi_snapshot_preview1`. These APIs are satisfied by the
`wasm-component-ld` target by using an [adapter] which implements WASIp1
in terms of WASIp2. This adapter comes at a cost, however, in terms of
runtime indirection and instantiation cost, so ideally the adapter would
be removed entirely. The purpose of this adapter was to provide a
smoother on-ramp from WASIp1 to WASIp2 when it was originally created.
The `wasm32-wasip2` target has been around for long enough now that it's
much more established. Additionally the only thing historically blocking
using WASIp2 directly was implementation effort. Work is now underway to
migrate wasi-libc itself to using WASIp2 directly and now seems as good
a time as any to migrate the Rust standard library too.
Implementation-wise the milestones here are:
* The `wasm32-wasip2` target now also depends on the `wasi` crate at
version 0.14.* in addition to the preexisting dependency of 0.11.*.
The 0.14.* release series binds WASIp2 APIs instead of WASIp1 APIs.
* Some preexisting naming around `mod wasi` or `wasi.rs` was renamed to
`wasip1` where appropriate. For example `std::sys::pal::wasi` is now
called `std::sys::pal::wasip1`.
* More platform-specific WASI modules are now split between WASIp1 and
WASIp2. For example getting the current time, randomness, and
process arguments now use WASIp2 APIs directly instead of using WASIp1
APIs that require an adapter.
It's worth pointing out that this PR does not migrate the entire
standard library away from using WASIp1 APIs on the `wasm32-wasip2`
target. Everything related to file descriptors and filesystem APIs is
still using WASIp1. Migrating that is left for a future PR. In the
meantime the goal of this change is to lay the groundwork necessary for
migrating in the future. Eventually the goal is to drop the `wasi`
0.11.* dependency on the `wasm32-wasip2` target (the `wasm32-wasip1`
target will continue to retain this dependency).
[adapter]: https://github.com/bytecodealliance/wasmtime/blob/main/crates/wasi-preview1-component-adapter/README.md
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)
improve process::abort rendering in Miri backtraces
Also, avoid using the `sys` function directly in the panic machinery -- that seems like an unnecessary layering violation.
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.
Fix `sys::process::windows::tests::test_thread_handle` spurious failure
Instead of sleeping, wait for the process to finish so that we can be sure it's done. We use a timeout because otherwise this test can be stuck indefinitely if it fails (unfortunately std doesn't currently have a way to wait with a timeout so a manual OS API call is necessary).
I also changed the test to run `whoami` and pipe the output to null so that it doesn't clutter up the test output.
Fixesrust-lang/rust#146024
Previously, attempting to create/truncate a file without write/append access
would result in platform-specific error messages:
- Unix: "Invalid argument"
- Windows: raw OS error code 87
These error codes look like system errors, which could waste hours
of debugging for what is actually an API misuse issue.
Implementation: `#[feature(nonpoison_condvar)]`
Tracking Issue: https://github.com/rust-lang/rust/issues/134645
This PR continues the effort made in https://github.com/rust-lang/rust/pull/144022 by adding the implementation of `nonpoison::condvar`.
Many of the changes here are similar to the changes made to implement `nonpoison::mutex`.
There are two other changes here. The first is that the `Barrier` implementation is migrated to use the `nonpoison::Condvar` instead of the `poison` variant. The second (which might be subject to some discussion) is that `WaitTimeoutResult` is moved up to `mod.rs`, as both `condvar` variants need that type (and I do not know if there is a better place to put it now).
### Related PRs
- `nonpoison_rwlock` implementation: https://github.com/rust-lang/rust/pull/144648
- `nonpoison_once` implementation: https://github.com/rust-lang/rust/pull/144653
fix(lib-std-fs): handle `usize` overflow in `read*`
I assume this is a non-breaking change, as there would be an OOM `panic` anyways. This patch ensures a fast-fail when there's not enough memory to load the file. This only changes behavior on platforms where `usize` is smaller than 64bits
Ralf Jung