Implement From<OwnedFd/Handle> for ChildStdin/out/err object
## Summary
Comments in `library/std/src/process.rs` ( ab08639e59 ) indicates that `ChildStdin`, `ChildStdout`, `ChildStderr` implements some traits that are not actually implemented: `FromRawFd`, `FromRawHandle`, and the `From<OwnedFd>/From<OwnedHandle>` from the io_safety feature.
In this PR I implement `FromRawHandle` and `FromRawFd` for those 3 objects.
## Usecase
I have a usecase where those implementations are basically needed. I want to customize
in the `Command::spawn` API how the pipes for the parent/child communications are created (mainly to strengthen the security attributes on them). I can properly setup the pipes,
and the "child" handles can be provided to `Child::spawn` easily using `Stdio::from_raw_handle`. However, there is no way to generate the `ChildStd*` objects from the raw handle of the created name pipe, which would be very useful to still expose the same API
than in other OS (basically a `spawn(...) -> (Child, ChildStdin, ChildStdout, ChildSterr)`, where on windows this is customized), and to for example use `tokio::ChildStdin::from_std` afterwards.
## Questions
* Are those impls OK to add? I have searched to see if those impls were missing on purpose, or if it was just never implemented because never needed. I haven't found any indication on why they couldn't be added, although the user clearly has to be very careful that the handle provided makes sense (i think, mainly that it is in overlapped mode for windows).
* If this change is ok, adding the impls for the io_safety feature would probably be best, or should it be done in another PR?
* I just copy-pasted the `#[stable(...)]` attributes, but the `since` value has to be updated, I'm not sure to which value.
fix a comment about assert_receiver_is_total_eq
"a type implements #[deriving]" doesn't make any sense, so I assume they meant "implement `Eq`"? Also the attribute is called `derive`.
error: unresolved link to `std::fmt::Error`
--> library/core/src/fmt/mod.rs:115:52
|
115 | /// This function will return an instance of [`std::fmt::Error`] on error.
|
|
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
Implement `From<{&,&mut} [T; N]>` for `Vec<T>` where `T: Clone`
Currently, if `T` implements `Clone`, we can create a `Vec<T>` from an `&[T]` or an `&mut [T]`, can we also support creating a `Vec<T>` from an `&[T; N]` or an `&mut [T; N]`? Also, do I need to add `#[inline]` to the implementation?
ACP: rust-lang/libs-team#220. [Accepted]
Closes#100880.
ConstParamTy: require Eq as supertrait
As discussed with `@BoxyUwu` [on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/260443-project-const-generics/topic/.60ConstParamTy.60.20and.20.60Eq.60).
We want to say that valtree equality on const generic params agrees with `==`, but that only makes sense if `==` actually exists, hence we should have an appropriate bound. Valtree equality is an equivalence relation, so such a type can always be `Eq` and not just `PartialEq`.
Properly print cstr literals in `proc_macro::Literal::to_string`
Previously we printed the contents of the string, rather than the actual string literal (e.g. `the c string` instead of `c"the c string"`).
Fixes#112820
cc #105723
Clarify example in `Pin::new_unchecked` docs
This example in the docs of `Pin::new_unchecked` puzzled me for a relatively long time. Now I understand that it comes down to the difference between dropping the `Pin` vs dropping the pinned value.
I have extended the explanation to highlight this difference. In my opinion it is clearer now, and I hope it helps others understand `Pin` better.
fix OS-specific I/O safety docs since the io_safety feature is stable
Looks like this text was forgotten to be updated when `io_safety` got stabilized: it still says "once the io_safety feature is stable".
Also adjust the wording a bit for how these docs relate to the general concept of I/O safety.
Add Minimal Std implementation for UEFI
# Implemented modules:
1. alloc
2. os_str
3. env
4. math
# Related Links
Tracking Issue: https://github.com/rust-lang/rust/issues/100499
API Change Proposal: https://github.com/rust-lang/libs-team/issues/87
# Additional Information
This was originally part of https://github.com/rust-lang/rust/pull/100316. Since that PR was becoming too unwieldy and cluttered, and with suggestion from `@dvdhrm,` I have extracted a minimal std implementation to this PR.
The example in `src/doc/rustc/src/platform-support/unknown-uefi.md` has been tested for `x86_64-unknown-uefi` and `i686-unknown-uefi` in OVMF. It would be great if someone more familiar with AARCH64 can help with testing for that target.
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
Document panics on unsigned wrapping_div/rem calls (#116063)
Add missing `# Panics` sections to the `uint_impl!` macro, documenting that the `wrapping_rem/div` calls will panic if passed zero.
Add the `cfg_match!` macro
# Movitation
Adds a match-like version of the `cfg_if` crate without a RFC [for the same reasons that caused `matches!` to be included in the standard library](https://github.com/rust-lang/rust/pull/65479).
* General-purpose (not domain-specific)
* Simple (the implementation is short) and useful (things can become difficult with several `cfg`s)
* Very popular [on crates.io ](https://crates.io/crates/cfg-if) (currently 3th in all-time downloads)
* The two previous points combined make it number three in [left-pad index](https://twitter.com/bascule/status/1184523027888988160) score
```rust
match_cfg! {
cfg(unix) => {
fn foo() { /* unix specific functionality */ }
}
cfg(target_pointer_width = "32") => {
fn foo() { /* non-unix, 32-bit functionality */ }
}
_ => {
fn foo() { /* fallback implementation */ }
}
}
```
# Considerations
A match-like syntax feels more natural in the sense that each macro fragment resembles an arm but I personally don't mind switching to any other desired syntax.
The lack of `#[ ... ]` is intended to reduce typing, nevertheless, the same reasoning described above can also be applied to this aspect.
Since blocks are intended to only contain items, anything but `cfg` is not expected to be supported at the current or future time.
~~Credits goes to `@gnzlbg` because most of the code was shamelessly copied from https://github.com/gnzlbg/match_cfg.~~
Credits goes to `@alexcrichton` because most of the code was shamelessly copied from https://github.com/rust-lang/cfg-if.
Raise minimum supported Apple OS versions
This implements the proposal to raise the minimum supported Apple OS versions as laid out in the now-completed MCP (https://github.com/rust-lang/compiler-team/issues/556).
As of this PR, rustc and the stdlib now support these versions as the baseline:
- macOS: 10.12 Sierra
- iOS: 10
- tvOS: 10
- watchOS: 5 (Unchanged)
In addition to everything this breaks indirectly, these changes also erase the `armv7-apple-ios` target (currently tier 3) because the oldest supported iOS device now uses ARMv7s. Not sure what the policy around tier3 target removal is but shimming it is not an option due to the linker refusing.
[Per comment](https://github.com/rust-lang/compiler-team/issues/556#issuecomment-1297175073), this requires a FCP to merge. cc `@wesleywiser.`
without this, the only way to create a `LitKind::Byte` is by
doing `"b'a'".parse::<Literal>()`, this solves that by enabling
`Literal::byte_character(b'a')`
- Some comment fixes.
- Make some functions unsafe.
- Make helpers module private.
- Rebase on master
- Update r-efi to v4.2.0
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
- Make BootServices unavailable if ExitBootServices event is signaled.
- Use thread locals for SystemTable and ImageHandle
Signed-off-by: Ayush Singh <ayushsingh1325@gmail.com>
Command: also print removed env vars
There is no real shell syntax for unsetting an env var so easily, so we have to make one up. But we already do that for showing the 'program' name so I hope that's okay here, too. No strong opinion on what that should look like, I went with `unset(VAR_NAME)` for now.
Call panic_display directly in const_panic_fmt.
`panic_str` just directly calls `panic_display`. The only reason `panic_str` exists, is for a lint to detect an expansion of `panic_2015!(expr)` (which expands to `panic_str`).
It is `panic_display` that is hooked by const-eval, which is the reason we call it here.
Part of https://github.com/rust-lang/rust/issues/116005
r? ``@oli-obk``
Rename BoxMeUp to PanicPayload.
"BoxMeUp" is not very clear. Let's rename that to a description of what it actually represents: a panic payload.
This PR also renames the structs that implement this trait to have more descriptive names.
Part of https://github.com/rust-lang/rust/issues/116005
r? `@oli-obk`
Simplify/Optimize FileEncoder
FileEncoder is basically a BufWriter except that it exposes access to the not-written-to-yet region of the buffer so that some users can write directly to the buffer. This strategy is awesome because it lets us avoid calling memcpy for small copies, but the previous strategy was based on the writer accessing a `&mut [MaybeUninit<u8>; N]` and returning a `&[u8]` which is an API which currently mandates the use of unsafe code, making that interface in general not that appealing.
So this PR cleans up the FileEncoder implementation and builds on that general idea of direct buffer access in order to prevent `memcpy` calls in a few key places when encoding the dep graph and rmeta tables. The interface used here is now 100% safe, but with the caveat that internally we need to avoid trusting the number of bytes that the provided function claims to have written.
The original primary objective of this PR was to clean up the FileEncoder implementation so that the fix for the following issues would be easy to implement. The fix for these issues is to correctly update self.buffered even when writes fail, which I think it's easy to verify manually is now done, because all the FileEncoder methods are small.
Fixes https://github.com/rust-lang/rust/issues/115298
Fixes https://github.com/rust-lang/rust/issues/114671
Fixes https://github.com/rust-lang/rust/issues/114045
Fixes https://github.com/rust-lang/rust/issues/108100
Fixes https://github.com/rust-lang/rust/issues/106787
Refactor `thread_info` to remove the `RefCell`
`thread_info` currently uses `RefCell`-based initialization. Refactor this to use `OnceCell` instead which is more performant and better suits the needs of one-time initialization.
This is nobody's bottleneck but OnceCell checks are a single `cmp` vs. `RefCell<Option>` needing runtime logic
Don't modify libstd to dump rustc ICEs
Do a much simpler thing and just dump a `std::backtrace::Backtrace` to file.
r? `@estebank` `@oli-obk`
Fixes#115610
Add initial libstd support for Xous
This patchset adds some minimal support to the tier-3 target `riscv32imac-unknown-xous-elf`. The following features are supported:
* alloc
* thread creation and joining
* thread sleeping
* thread_local
* panic_abort
* mutex
* condvar
* stdout
Additionally, internal support for the various Xous primitives surrounding IPC have been added as part of the Xous FFI. These may be exposed as part of `std::os::xous::ffi` in the future, however for now they are not public.
This represents the minimum viable product. A future patchset will add support for networking and filesystem support.
get rid of duplicate primitive_docs
Having this duplicate makes editing that file very annoying. And at least locally the generated docs still look perfectly fine...
Add `minmax{,_by,_by_key}` functions to `core::cmp`
This PR adds the following functions:
```rust
// mod core::cmp
#![unstable(feature = "cmp_minmax")]
pub fn minmax<T>(v1: T, v2: T) -> [T; 2]
where
T: Ord;
pub fn minmax_by<T, F>(v1: T, v2: T, compare: F) -> [T; 2]
where
F: FnOnce(&T, &T) -> Ordering;
pub fn minmax_by_key<T, F, K>(v1: T, v2: T, mut f: F) -> [T; 2]
where
F: FnMut(&T) -> K,
K: Ord;
```
(they are also `const` under `#[feature(const_cmp)]`, I've omitted `const` stuff for simplicity/readability)
----
Semantically these functions are equivalent to `{ let mut arr = [v1, v2]; arr.sort(); arr }`, but since they operate on 2 elements only, they are implemented as a single comparison.
Even though that's basically a sort, I think "sort 2 elements" operation is useful on it's own in many cases. Namely, it's a common pattern when you have 2 things, and need to know which one is smaller/bigger to operate on them differently.
I've wanted such functions countless times, most recently in #109402, so I thought I'd propose them.
----
r? libs-api
Small wins for formatting-related code
This PR does two small wins in fmt code:
- Override `write_char` for `PadAdapter` to use inner buffer's `write_char`
- Override some `write_fmt` implementations to avoid avoid the additional indirection and vtable generated by the default impl.
make `Debug` impl for `ascii::Char` match that of `char`
# Objective
use a more recognisable format for the `Debug` impl on `ascii::Char` than the derived one based off the enum variants. The alogorithm used is the following:
- escape `ascii::Char::{Null, CharacterTabulation, CarraigeReturn, LineFeed, ReverseSolidus, Apostrophe}` to `'\0'`, `'\t'`, `'\r'`, `'\n'`, `'\\'` and `'\''` respectively. these are the same escape codes as `<char as Debug>::fmt` uses.
- if `u8::is_ascii_control` is false, print the character wrapped in single quotes.
- otherwise, print in the format `'\xAB'` where `A` and `B` are the hex nibbles of the byte. (`char` uses unicode escapes and this seems like the corresponding ascii format).
Tracking issue: https://github.com/rust-lang/rust/issues/110998
impl Step for IP addresses
ACP: rust-lang/libs-team#235
Note: since this is insta-stable, it requires an FCP.
Separating out from the bit operations PR since it feels logically disjoint, and so their FCPs can be separate.
Update doc for `alloc::format!` and `core::concat!`
Closes#115551.
Used comments instead of `assert!`s as [`std::fmt`](https://doc.rust-lang.org/std/fmt/index.html#usage) uses comments.
Should all the str-related macros (`format!`, `format_args!`, `concat!`, `stringify!`, `println!`, `writeln!`, etc.) references each others? For instance, [`concat!`](https://doc.rust-lang.org/core/macro.concat.html) mentions that integers are stringified, but don't link to `stringify!`.
`@rustbot` label +A-docs +A-fmt
Specialize count for range iterators
Since `size_hint` is already specialized, it feels apt to specialize `count` as well. Without any specialized version of `ExactSizeIterator::len` or `Step::steps_between`, this feels like a more reliable way of accessing this without having to rely on knowing that `size_hint` is correct.
In my case, this is particularly useful to access the `steps_between` implementation for `char` from the standard library without having to compute it manually.
I didn't think it was worth modifying the `Step` trait to add a version of `steps_between` that used native overflow checks since this is just doing one subtraction in most cases anyway, and so I decided to make the inclusive version use `checked_add` so it didn't have this lopsided overflow-checks-but-only-sometimes logic.
clarify that unsafe code must not rely on our safe traits
This adds a disclaimer to PartialEq, Eq, PartialOrd, Ord, Hash, Deref, DerefMut.
We already have a similar disclaimer in ExactSizeIterator (worded a bit differently):
```
/// Note that this trait is a safe trait and as such does *not* and *cannot*
/// guarantee that the returned length is correct. This means that `unsafe`
/// code **must not** rely on the correctness of [`Iterator::size_hint`]. The
/// unstable and unsafe [`TrustedLen`](super::marker::TrustedLen) trait gives
/// this additional guarantee.
```
If there are any other traits that should carry such a disclaimer, please let me know.
Fixes https://github.com/rust-lang/rust/issues/73682
Make useless_ptr_null_checks smarter about some std functions
This teaches the `useless_ptr_null_checks` lint that some std functions can't ever return null pointers, because they need to point to valid data, get references as input, etc.
This is achieved by introducing an `#[rustc_never_returns_null_ptr]` attribute and adding it to these std functions (gated behind bootstrap `cfg_attr`).
Later on, the attribute could maybe be used to tell LLVM that the returned pointer is never null. I don't expect much impact of that though, as the functions are pretty shallow and usually the input data is already never null.
Follow-up of PR #113657Fixes#114442
Rework `no_coverage` to `coverage(off)`
As discussed at the tail of https://github.com/rust-lang/rust/issues/84605 this replaces the `no_coverage` attribute with a `coverage` attribute that takes sub-parameters (currently `off` and `on`) to control the coverage instrumentation.
Allows future-proofing for things like `coverage(off, reason="Tested live", issue="#12345")` or similar.
`thread_info` currently uses `RefCell`-based initialization. Refactor
this to use `OnceCell` instead which is more performant and better suits
the needs of one-time initialization.
Allow redirecting subprocess stdout to our stderr etc. (redux)
This is the code from #88561, tidied up, including review suggestions, and with the for-testing-only CI commit removed. FCP for the API completed in #88561.
I have made a new MR to facilitate review. The discussion there is very cluttered and the branch is full of changes (in many cases as a result of changes to other Rust stdlib APIs since then). Assuming this MR is approvedl we should close that one.
### Reviewer doing a de novo review
Just code review these four commits.. FCP discussion starts here: https://github.com/rust-lang/rust/pull/88561#issuecomment-1640527595
Portability tests: you can see that this branch works on Windows too by looking at the CI results in #88561, which has the same code changes as this branch but with an additional "DO NOT MERGE" commit to make the Windows tests run.
### Reviewer doing an incremental review from some version of #88561
Review the new commits since your last review. I haven't force pushed the branch there.
git diff the two branches (eg `git diff 176886197d6..0842b69c219`). You'll see that the only difference is in gitlab CI files. You can also see that *this* MR doesn't touch those files.
This implementation is wrong. Like the impl for From<File>, it is
forced to panic because process::Stdio in unsupported/process.rs
doesn't have a suitable variant.
The root cause of the problem is that process::Stdio in
unsupported/process.rs has any information in it at all.
I'm pretty sure that it should just be a unit struct. However,
making that build on all platforms is going to be a lot of work,
iterating through CI and/or wrestling Docker.
I don't think this extra panic is making things significantly worse.
For now I have added some TODOs.
Clarify stability guarantee for lifetimes in enum discriminants
Since `std::mem::Discriminant` erases lifetimes, it should be clarified that changing the concrete value of a lifetime parameter does not change the value of an enum discriminant for a given variant. This is useful as it guarantees that it is safe to transmute `Discriminant<Foo<'a>>` to `Discriminant<Foo<'b>>` for any combination of `'a` and `'b`. This also holds for type-generics as long as the type parameters do not change, e.g. `Discriminant<Foo<T, 'a>>` can be transmuted to `Discriminant<Foo<T, 'b>>`.
Side note: Is what I've written actually enough to imply soundness (or rather codify it), or should it specifically be spelled out that it's OK to transmute in the above way?
Lint on invalid usage of `UnsafeCell::raw_get` in reference casting
This PR proposes to take into account `UnsafeCell::raw_get` method call for non-Freeze types for the `invalid_reference_casting` lint.
The goal of this is to catch those kind of invalid reference casting:
```rust
fn as_mut<T>(x: &T) -> &mut T {
unsafe { &mut *std::cell::UnsafeCell::raw_get(x as *const _ as *const _) }
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
}
```
r? `@est31`
Update stdarch submodule and remove special handling in cranelift codegen for some AVX and SSE2 LLVM intrinsics
https://github.com/rust-lang/stdarch/pull/1463 reimplemented some x86 intrinsics to avoid using some x86-specific LLVM intrinsics:
* Store unaligned (`_mm*_storeu_*`) use `<*mut _>::write_unaligned` instead of `llvm.x86.*.storeu.*`.
* Shift by immediate (`_mm*_s{ll,rl,ra}i_epi*`) use `if` (srl, sll) or `min` (sra) to simulate the behaviour when the RHS is out of range. RHS is constant, so the `if`/`min` will be optimized away.
This PR updates the stdarch submodule to pull these changes and removes special handling for those LLVM intrinsics from cranelift codegen. I left gcc codegen untouched because there are some autogenerated lists.
Move RawOsError defination to sys
This was originally a part of https://github.com/rust-lang/rust/pull/105861, but I feel it should be its own PR since the raw os error is still unstable.
Outline panicking code for `RefCell::borrow` and `RefCell::borrow_mut`
This outlines panicking code for `RefCell::borrow` and `RefCell::borrow_mut` to reduce code size.
Use std::io::Error::is_interrupted everywhere
In https://github.com/rust-lang/rust/pull/115228 I introduced this helper and started using it, this PR uses it to replace all applicable uses of `std::io::Error::kind`. The justification is the same; for whatever reason LLVM totally flops optimizing `Error::kind` so it's nice to use it less.
FYI ``@mkroening`` I swear the hermit changes look good, but I was so sure about the previous PR.
