default_alloc_error_hook: explain difference to default __rdl_oom in alloc
Though I'm not sure if that is really the reason that this code is duplicated. On no_std it may already be possible to call user-defined code on allocation failure.
Fix HorizonOS build broken by #124210
HorizonOS (for the Tier-3 target `armv6k-nintendo-3ds`) does not support `dirfd()`, as many other similar targets.
In the stabilization attempt of `#[unix_sigpipe = "sig_dfl"]`, a concern
was raised related to using a language attribute for the feature: Long
term, we want `fn lang_start()` to be definable by any crate, not just
libstd. Having a special language attribute in that case becomes
awkward.
So as a first step towards towards the next stabilization attempt, this
PR changes the `#[unix_sigpipe = "..."]` attribute to a compiler flag
`-Zon-broken-pipe=...` to remove that concern, since now the language
is not "contaminated" by this feature.
Another point was also raised, namely that the ui should not leak
**how** it does things, but rather what the **end effect** is. The new
flag uses the proposed naming. This is of course something that can be
iterated on further before stabilization.
Use `target_vendor = "apple"` instead of `target_os = "..."`
Use `target_vendor = "apple"` instead of `all(target_os = "macos", target_os = "ios", target_os = "tvos", target_os = "watchos", target_os = "visionos")`.
The apple targets are quite close to being identical, with iOS, tvOS, watchOS and visionOS being even closer, so using `target_vendor` when possible makes it clearer when something is actually OS-specific, or just Apple-specific.
Note that `target_vendor` will [be deprecated in the future](https://github.com/rust-lang/rust/issues/100343), but not before an alternative (like `target_family = "apple"`) is available.
While doing this, I found various inconsistencies and small mistakes in the standard library, see the commits for details. Will follow-up with an extra PR for a similar issue that need a bit more discussion. EDIT: https://github.com/rust-lang/rust/pull/124494
Since you've talked about using `target_vendor = "apple"` in the past:
r? workingjubilee
CC `@simlay,` `@thomcc`
`@rustbot` label O-macos O-ios O-tvos O-watchos O-visionos
`man posix_spawn` documents it to be able to return `ENOENT`, and there
should be nothing preventing this. Tested in the iOS simulator and on
Mac Catalyst.
Abort a process when FD ownership is violated
When an owned FD has already been closed before it's dropped that means something else touched an FD in ways it is not allowed to. At that point things can already be arbitrarily bad, e.g. clobbered mmaps. Recovery is not possible.
All we can do is hasten the fire.
Unlike the previous attempt in #124130 this shouldn't suffer from the possibility that FUSE filesystems can return arbitrary errors.
Unconditionally call `really_init` on GNU/Linux
This makes miri not diverge in behavior, it fixes running Rust linux-gnu binaries on musl with gcompat, it fixes dlopen edge-cases that cranelift somehow hits, etc.
Fixes#124126
thou hast gazed into this abyss with me:
r? ``@ChrisDenton``
This makes miri not diverge in behavior, it fixes running Rust linux-gnu
binaries on musl with gcompat, it fixes dlopen edge-cases that cranelift
somehow hits, etc.
thread_local: be excruciatingly explicit in dtor code
Use raw pointers to accomplish internal mutability, and clearly split references where applicable. This reduces the likelihood that any of these parts are misunderstood, either by humans or the compiler's optimizations.
Fixes#124317
r? ``@joboet``
PathBuf: replace transmuting by accessor functions
The existing `repr(transparent)` was anyway insufficient as `OsString` was not `repr(transparent)`. And furthermore, on Windows it was blatantly wrong as `OsString` wraps `Wtf8Buf` which is a `repr(Rust)` type with 2 fields:
51a7396ad3/library/std/src/sys_common/wtf8.rs (L131-L146)
So let's just be honest about what happens and add accessor methods that make this abstraction-breaking act of PathBuf visible on the APIs that it pierces through.
Fixes https://github.com/rust-lang/rust/issues/124409
windows fill_utf16_buf: explain the expected return value
The comment just says "return what the syscall returns", but that doesn't work for all syscalls as the Windows API is not consistent in how buffer size is negotiated. For instance, GetUserProfileDirectoryW works a bit differently, and so home_dir_crt has to translate this to the usual protocol itself. So it's worth describing that protocol.
r? ``@ChrisDenton``
HermitOS supports getdents64. As under Linux, the dirent64 entry
`d_off` is not longer used, because its definition is not clear.
Instead of `d_off` the entry `d_reclen` is used to determine the
end of the dirent64 entry.
remove an unused type from the reentrant lock tests
At least it seems unused. This was added back in 45aa6c8d1b together with a test related to poisoning; when the test got removed, it seems like it was forgotten to also remove this type.
Fix watchOS and visionOS for pread64 and pwrite64 calls
In #122880, links to `preadv64` and `pwritev64` were added for `watchOS` however the underlying [`weak!` macro did not include `target_os = "watchos"`](c45dee5efd/library/std/src/sys/pal/unix/weak.rs (L30-L74)).
This resulted in an `xcodebuild` error when targeting `watchOS`:
```
Undefined symbols for architecture arm64:
"_preadv64", referenced from:
__rust_extern_with_linkage_preadv64 in libliveview_native_core.a[274](std-324fdd8d31e8eaa2.std.e18cf7e8d0336778-cgu.08.rcgu.o)
"_pwritev64", referenced from:
__rust_extern_with_linkage_pwritev64 in libliveview_native_core.a[274](std-324fdd8d31e8eaa2.std.e18cf7e8d0336778-cgu.08.rcgu.o)
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```
So I added them. I also went ahead and added the same for visionOS because it's bound to create the same issue.
When an EBADF happens then something else already touched an FD in ways it is not allowed to.
At that point things can already be arbitrarily bad, e.g. clobbered mmaps.
Recovery is not possible.
All we can do is hasten the fire.
Use raw-dylib for Windows synchronization functions
Fixes#123999 by using the raw-dylib feature to specify the DLL to load the Windows futex functions from (e.g. [`WaitOnAddress`](https://learn.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-waitonaddress)). This avoids reliance on the import library causing that issue.
With apologies to ``@bjorn3,`` as it's currently necessary to revert this for cranelift.
Add support for Arm64EC to the Standard Library
Adds the final pieces so that the standard library can be built for arm64ec-pc-windows-msvc (initially added in #119199)
* Bumps `windows-sys` to 0.56.0, which adds support for Arm64EC.
* Correctly set the `isEC` parameter for LLVM's `writeArchive` function.
* Add `#![feature(asm_experimental_arch)]` to library crates where Arm64EC inline assembly is used, as it is currently unstable.
Document overrides of `clone_from()` in core/std
As mentioned in https://github.com/rust-lang/rust/pull/96979#discussion_r1379502413
Specifically, when an override doesn't just forward to an inner type, document the behavior and that it's preferred over simply assigning a clone of source. Also, change instances where the second parameter is "other" to "source".
I reused some of the wording over and over for similar impls, but I'm not sure that the wording is actually *good*. Would appreciate feedback about that.
Also, now some of these seem to provide pretty specific guarantees about behavior (e.g. will reuse the exact same allocation iff the len is the same), but I was basing it off of the docs for [`Box::clone_from`](https://doc.rust-lang.org/1.75.0/std/boxed/struct.Box.html#method.clone_from-1) - I'm not sure if providing those strong guarantees is actually good or not.
Use queue-based `RwLock` on more platforms
This switches over Windows 7, SGX and Xous to the queue-based `RwLock` implementation added in #110211, thereby fixing #121949 for Windows 7 and partially resolving #114581 on SGX. TEEOS can't currently be switched because it doesn't have a good thread parking implementation.
CC `@roblabla` `@raoulstrackx` `@xobs` Could you help me test this, please?
r? `@ChrisDenton` the Windows stuff should be familiar to you
zkvm: fix references to `os_str` module
The `os_str` module has been moved to `sys`. This change fixes build issues by changing `use` to point to `crate::sys::os_str`.
Miri on Windows: run .CRT$XLB linker section on thread-end
Hopefully fixes https://github.com/rust-lang/rust/issues/123583
First commit is originally by `@bjorn3`
r? `@oli-obk`
Cc `@ChrisDenton`
Link MSVC default lib in core
## The Problem
On Windows MSVC, Rust invokes the linker directly. This means only the objects and libraries Rust explicitly passes to the linker are used. In short, this is equivalent to passing `-nodefaultlibs`, `-nostartfiles`, etc for gnu compilers.
To compensate for this [the libc crate links to the necessary libraries](a0f5b4b213/src/windows/mod.rs (L258-L261)). The libc crate is then linked from std, thus when you use std you get the defaults back.or integrate with C/C++.
However, this has a few problems:
- For `no_std`, users are left to manually pass the default lib to the linker
- Whereas `std` has the opposite problem, using [`/nodefaultlib`](https://learn.microsoft.com/en-us/cpp/build/reference/nodefaultlib-ignore-libraries?view=msvc-170) doesn't work as expected because Rust treats them as normal libs. This is a particular problem when you want to use e.g. the debug CRT libraries in their place or integrate with C/C++..
## The solution
This PR fixes this in two ways:
- moves linking the default lib into `core`
- passes the lib to the linker using [`/defaultlib`](https://learn.microsoft.com/en-us/cpp/build/reference/defaultlib-specify-default-library?view=msvc-170). This allows users to override it in the normal way (i.e. with [`/nodefaultlib`](https://learn.microsoft.com/en-us/cpp/build/reference/nodefaultlib-ignore-libraries?view=msvc-170)).
This is more or less equivalent to what the MSVC C compiler does. You can see what this looks like in my second commit, which I'll reproduce here for convenience:
```rust
// In library/core
#[cfg(all(windows, target_env = "msvc"))]
#[link(
name = "/defaultlib:msvcrt",
modifiers = "+verbatim",
cfg(not(target_feature = "crt-static"))
)]
#[link(name = "/defaultlib:libcmt", modifiers = "+verbatim", cfg(target_feature = "crt-static"))]
extern "C" {}
```
## Alternatives
- Add the above to `unwind` and `std` but not `core`
- The status quo
- Some other kind of compiler magic maybe
This bares some discussion so I've t-libs nominated it.
Add missing `unsafe` to some internal `std` functions
Adds `unsafe` to a few internal functions that have safety requirements but were previously not marked as `unsafe`. Specifically:
- `std::sys::pal::unix:🧵:min_stack_size` needs to be `unsafe` as `__pthread_get_minstack` might dereference the passed pointer. All callers currently pass a valid initialised `libc::pthread_attr_t`.
- `std:🧵:Thread::new` (and `new_inner`) need to be `unsafe` as it requires the passed thread name to be valid UTF-8, otherwise `Thread::name` will trigger undefined behaviour. I've taken the opportunity to split out the unnamed thread case into a separate `new_unnamed` function to make the safety requirement clearer. All callers meet the safety requirement now that #123505 has been merged.
OpenBSD fix long socket addresses
Original diff from ``@notgull`` in #118349, small changes from me.
on OpenBSD, getsockname(2) returns the actual size of the socket address, and not the len of the content. Figure out the length for ourselves. see https://marc.info/?l=openbsd-bugs&m=170105481926736&w=2Fixes#116523
Thread local updates for idiomatic examples
Update thread local examples to make more idiomatic use of `Cell` for `Copy` types, `RefCell` for non-`Copy` types.
Also shrink the size of `unsafe` blocks, add `SAFETY` comments, and fix `clippy::redundant_closure_for_method_calls`.
Update documentation of Path::to_path_buf and Path::ancestors
`Path::to_path_buf`
> Changes the example from using the qualified path of PathBuf with an import. This is what's done in all other Path/PathBuf examples and makes the code look a bit cleaner.
`Path::ancestors`
> If you take a quick glance at the documentation for Path::ancestors, the unwraps take the natural focus. Potentially indicating that ancestors might panic.
In the reworked version I've also moved the link with parent returning None and that the iterator will always yield &self to before the yield examples.
Feel free to cherry-pick the changes you like.
zkvm: fix path to cmath in zkvm module
I don't know why the original author decided to use relative paths.
I think it would be better to use `use crate::sys::cmath;`
The according issue can be found here https://github.com/risc0/risc0/issues/1647
Remove `sys_common::thread`
Part of #117276.
The stack size calculation isn't system-specific at all and can just live together with the rest of the spawn logic.
Move rare overflow error to a cold function
`scoped.spawn()` generates unnecessary inlined panic-formatting code for a branch that will never be taken.
Panic on overflow in `BorrowedCursor::advance`
Passing `usize::MAX` to `advance` clearly isn't correct, but the current assertion fails to detect this when overflow checks are disabled. This isn't unsound, but should probably be fixed regardless.
Avoid a panic in `set_output_capture` in the default panic handler
This avoid a panic in the default panic handler by not using `set_output_capture` as `OUTPUT_CAPTURE.with` may panic once `OUTPUT_CAPTURE` is dropped.
A new non-panicking `try_set_output_capture` variant of `set_output_capture` is added for use in the default panic handler.
Original diff from @notgull in #118349, small changes from me.
on OpenBSD, getsockname(2) returns the actual size of the socket address, and
not the len of the content. Figure out the length for ourselves.
see https://marc.info/?l=openbsd-bugs&m=170105481926736&w=2Fixes#116523
clean up docs for `File::sync_*`
* Clarify that `sync_all` also writes data and not just metadata.
* Clarify that dropping a file is not equivalent to calling `sync_all` and ignoring the result. `sync_all` the still the recommended way to detect errors before closing, because we don't have a dedicated method for that.
* Add a link from `sync_all` to `sync_data`, because that's what the user might want to use instead.
* Add doc aliases for `fsync` -> `sync_all` and `fdatasync` -> `sync_data`. Those are the POSIX standard names for these functions. I was trying to find out what we call `fsync` in Rust and had to search through the source code to find it, so this alias should help with that in the future.
Document restricted_std
This PR aims to pin down exactly what restricted_std is meant to achieve and what it isn't.
This commit fixes https://github.com/rust-lang/wg-cargo-std-aware/issues/87 by explaining why the error appears and what the choices the user has. The error describes how std cannot function without knowing about some form of OS/platform support. Any features of std that work without an OS should be moved to core/alloc (see https://github.com/rust-lang/rust/issues/27242https://github.com/rust-lang/rust/issues/103765).
Note that the message says "platform" and "environment" because, since https://github.com/rust-lang/rust/pull/120232, libstd can be built for some JSON targets. This is still unsupported (all JSON targets probably should be unstable https://github.com/rust-lang/wg-cargo-std-aware/issues/90), but a JSON target with the right configuration should hopefully have some partial libstd support.
I propose closing https://github.com/rust-lang/wg-cargo-std-aware/issues/69 as "Won't fix" since any support of std without properly configured os, vendor or env fields is very fragile considering future upgrades of Rust or dependencies. In addition there's no likely path to it being fixed long term (making std buildable for all targets being the only solution). This is distinct from tier 3 platforms with limited std support implemented (and as such aren't restricted_std) because these platforms can conceptually work in the future and std support should mainly improve over time.
The alternative to closing https://github.com/rust-lang/wg-cargo-std-aware/issues/69 is a new crate feature for std which escapes the restricted_std mechanism in build.rs. It could be used with the -Zbuild-std-features flag if we keep it permanently unstable, which I hope we can do anyway. A minor side-effect in this scenario is that std wouldn't be marked as unstable if documentation for it were generated with build-std.
cc ```@ehuss```
`f16` and `f128` step 4: basic library support
This is the next step after https://github.com/rust-lang/rust/pull/121926, another portion of https://github.com/rust-lang/rust/pull/114607
Tracking issue: https://github.com/rust-lang/rust/issues/116909
This PR adds the most basic operations to `f16` and `f128` that get lowered as LLVM intrinsics. This is a very small step but it seemed reasonable enough to add unopinionated basic operations before the larger modules that are built on top of them.
r? ```@Amanieu``` since you were pretty involved in the RFC
cc ```@compiler-errors```
```@rustbot``` label +T-libs-api +S-blocked +F-f16_and_f128
Rollup of 7 pull requests
Successful merges:
- #118391 (Add `REDUNDANT_LIFETIMES` lint to detect lifetimes which are semantically redundant)
- #123534 (Windows: set main thread name without re-encoding)
- #123659 (Add support to intrinsics fallback body)
- #123689 (Add const generics support for pattern types)
- #123701 (Only assert for child/parent projection compatibility AFTER checking that theyre coming from the same place)
- #123702 (Further cleanup cfgs in the UI test suite)
- #123706 (rustdoc: reduce per-page HTML overhead)
r? `@ghost`
`@rustbot` modify labels: rollup
The import is used once in this file, inside `posix_spawn`, so let's move the import into that function instead, to reduce the number of `cfg`s that need to be kept in sync.
If you take a quick glance at the documentation for Path::ancestors, the unwraps take the natural focus. Potentially indicating that ancestors might panic.
In the reworked version I've also moved the link with parent returning None and that the iterator will always yield &self to before the yield examples.
Specialize many implementations of `Read::read_buf_exact`
This makes all implementations of `Read` that have a specialized `read_exact` implementation also have one for `read_buf_exact`.
Changes the example from using the qualified path of PathBuf with an import. This is what's done in all other Path/PathBuf examples and makes the code look a bit cleaner.
Show mode_t as octal in std::fs Debug impls
Example:
```rust
fn main() {
println!("{:?}", std::fs::metadata("Cargo.toml").unwrap().permissions());
}
```
- Before: `Permissions(FilePermissions { mode: 33204 })`
- ~~After: `Permissions(FilePermissions { mode: 0o100664 })`~~
- After: `Permissions(FilePermissions { mode: 0o100664 (-rw-rw-r--) })`
~~I thought about using the format from `ls -l` (`-rw-rw-r--`, `drwxrwxr-x`) but I am not sure how transferable the meaning of the higher bits between different unix systems, and anyway starting the value with a leading negative-sign seems objectionable.~~
Store all args in the unsupported Command implementation
This allows printing them in the Debug impl as well as getting them again using the get_args() method. This allows programs that would normally spawn another process to more easily show which program they would have spawned if not for the fact that the target doesn't support spawning child processes without requiring intrusive changes to keep the args. For example rustc compiled to wasi will show the full linker invocation that would have been done.
The `thread_local!` examples use `RefCell` for `Copy` types. Update
examples to have one `Copy` and one non-`Copy` type using `Cell` and
`RefCell`, respectively.
Implement minimal, internal-only pattern types in the type system
rebase of https://github.com/rust-lang/rust/pull/107606
You can create pattern types with `std::pat::pattern_type!(ty is pat)`. The feature is incomplete and will panic on you if you use any pattern other than integral range patterns. The only way to create or deconstruct a pattern type is via `transmute`.
This PR's implementation differs from the MCP's text. Specifically
> This means you could implement different traits for different pattern types with the same base type. Thus, we just forbid implementing any traits for pattern types.
is violated in this PR. The reason is that we do need impls after all in order to make them usable as fields. constants of type `std::time::Nanoseconds` struct are used in patterns, so the type must be structural-eq, which it only can be if you derive several traits on it. It doesn't need to be structural-eq recursively, so we can just manually implement the relevant traits on the pattern type and use the pattern type as a private field.
Waiting on:
* [x] move all unrelated commits into their own PRs.
* [x] fix niche computation (see 2db07f94f44f078daffe5823680d07d4fded883f)
* [x] add lots more tests
* [x] T-types MCP https://github.com/rust-lang/types-team/issues/126 to finish
* [x] some commit cleanup
* [x] full self-review
* [x] remove 61bd325da19a918cc3e02bbbdce97281a389c648, it's not necessary anymore I think.
* [ ] ~~make sure we never accidentally leak pattern types to user code (add stability checks or feature gate checks and appopriate tests)~~ we don't even do this for the new float primitives
* [x] get approval that [the scope expansion to trait impls](https://rust-lang.zulipchat.com/#narrow/stream/326866-t-types.2Fnominated/topic/Pattern.20types.20types-team.23126/near/427670099) is ok
r? `@BoxyUwU`
This allows printing them in the Debug impl as well as getting them
again using the get_args() method. This allows programs that would
normally spawn another process to more easily show which program they
would have spawned if not for the fact that the target doesn't support
spawning child processes without requiring intrusive changes to keep the
args. For example rustc compiled to wasi will show the full linker
invocation that would have been done.
extending filesystem support for Hermit
Extending `std` to create, change and read a directory for Hermit.
Hermit is a tier 3 platform and this PR changes only files, wich are related to the tier 3 platform.
impl get_mut_or_init and get_mut_or_try_init for OnceCell and OnceLock
See also https://github.com/rust-lang/rust/issues/74465#issuecomment-1676522051
I'm trying to understand the process for such proposal. And I'll appreciate it if anyone can guide me the next step for consensus or adding tests.
