This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd/sys *that are not involved in any currently open PR*
to minimize merge conflicts. THe list of files involved in open PRs was
determined by querying GitHub's GraphQL API with this script:
https://gist.github.com/dtolnay/aa9c34993dc051a4f344d1b10e4487e8
With the list of files from the script in outstanding_files, the
relevant commands were:
$ find src/libstd/sys -name '*.rs' \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ rg libstd/sys outstanding_files | xargs git checkout --
Repeating this process several months apart should get us coverage of
most of the rest of the files.
To confirm no funny business:
$ git checkout $THIS_COMMIT^
$ git show --pretty= --name-only $THIS_COMMIT \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ git diff $THIS_COMMIT # there should be no difference
File handles shouldn't be inheritable in general.
`std::process::Command` takes care of making them inheritable when child
processes are spawned, and the `CREATE_PROCESS_LOCK` protects against
races in that section on Windows. But `File::try_clone` has been
creating inheritable file descriptors outside of that lock, which could
be leaking into other child processes unintentionally.
See also https://github.com/rust-lang/rust/pull/31069#discussion_r334117665.
This commit rejiggers the generics used in the implementation of
`Command::env` with the purpose of reducing the amount of codegen that
needs to happen in consumer crates, instead preferring to generate code
into libstd.
This was found when profiling the compile times of the `cc` crate where
the binary rlib produced had a lot of `BTreeMap` code compiled into it
but the crate doesn't actually use `BTreeMap`. It turns out that
`Command::env` is generic enough to codegen the entire implementation in
calling crates, but in this case there's no performance concern so it's
fine to compile the code into the standard library.
This change is done by removing the generic on the `CommandEnv` map
which is intended to handle case-insensitive variables on Windows.
Instead now a generic isn't used but rather a `use` statement defined
per-platform is used.
With this commit a debug build of `Command::new("foo").env("a", "b")`
drops from 21k lines of LLVM IR to 10k.
Add UWP MSVC targets
Hi,
- The README URI change is the correct one for VS2019 community edition, which I suspect most people would use. Doesn't _need_ to be merged though.
- This 5e6619edd1 fixes the UWP build (msvc or not, doesn't matter). I suspect it broke with recent changes unnoticed because no CI.
- Store lib location is found through the VCToolsInstallDir env variable. The end of the path is currently for the VS2019 store lib locations only.
- I could not test the aarch64_uwp_windows_msvc target because the rust build script does not currently support arm64 msvc AFAIU.
add `repr(transparent)` to `IoSliceMut` where missing
tried using `IoSliceMut` in FFI, got `improper_ctypes` warning.
according to the docs: `IoSliceMut` is "guaranteed to be ABI compatible with the `iovec` type" so it should be usable in FFI.
`IoSlice` is also `repr(transparent)` for every platform where these types contain `iovec`-like types.
vxworks also has `IoSliceMut` as transparent so its not even consistently one or the other.
no comment about this next to the types or in the PR that introduced the types, so assuming this was just missed.
r? @sfackler
This commit adds accessors for more fields in `fs::Metadata` on Windows
which weren't previously exposed. There's two sources of `fs::Metadata`
on Windows currently, one from `DirEntry` and one from a file itself.
These two sources of information don't actually have the same set of
fields exposed in their stat information, however. To handle this the
platform-specific accessors of Windows-specific information all return
`Option` to return `None` in the case a metadata comes from a
`DirEntry`, but they're guaranteed to return `Some` if it comes from a
file itself.
This is motivated by some changes in CraneStation/wasi-common#42, and
I'm curious how others feel about this platform-specific functionality!
Attempt to create sockets with the WSA_FLAG_NO_HANDLE_INHERIT flag, and
handle the potential error gracefully (as the flag isn't support on
Windows 7 before SP1)
macos tlv workaround
fixes: #60141
Includes:
* remove dead code: `requires_move_before_drop`. This hasn't been needed for a while now (oops I should have removed it in #57655)
* redox had a copy of `fast::Key` (not sure why?). That has been removed.
* Perform a `read_volatile` on OSX to reduce `tlv_get_addr` calls per `__getit` from (4-2 depending on context) to 1.
`tlv_get_addr` is relatively expensive (~1.5ns on my machine).
Previously, in contexts where `__getit` was inlined, 4 calls to `tlv_get_addr` were performed per lookup. For some reason when `__getit` is not inlined this is reduced to 2x - and performance improves to match.
After this PR, I have only ever seen 1x call to `tlv_get_addr` per `__getit`, and macos now benefits from situations where `__getit` is inlined.
I'm not sure if the `read_volatile(&&__KEY)` trick is working around an LLVM bug, or a rustc bug, or neither.
r? @alexcrichton
This commit removes all in-tree support for generating backtraces in
favor of depending on the `backtrace` crate on crates.io. This resolves
a very longstanding piece of duplication where the standard library has
long contained the ability to generate a backtrace on panics, but the
code was later extracted and duplicated on crates.io with the
`backtrace` crate. Since that fork each implementation has seen various
improvements one way or another, but typically `backtrace`-the-crate has
lagged behind libstd in one way or another.
The goal here is to remove this duplication of a fairly critical piece
of code and ensure that there's only one source of truth for generating
backtraces between the standard library and the crate on crates.io.
Recently I've been working to bring the `backtrace` crate on crates.io
up to speed with the support in the standard library which includes:
* Support for `StackWalkEx` on MSVC to recover inline frames with
debuginfo.
* Using `libbacktrace` by default on MinGW targets.
* Supporting `libbacktrace` on OSX as an option.
* Ensuring all the requisite support in `backtrace`-the-crate compiles
with `#![no_std]`.
* Updating the `libbacktrace` implementation in `backtrace`-the-crate to
initialize the global state with the correct filename where necessary.
After reviewing the code in libstd the `backtrace` crate should be at
exact feature parity with libstd today. The backtraces generated should
have the same symbols and same number of frames in general, and there's
not known divergence from libstd currently.
Note that one major difference between libstd's backtrace support and
the `backtrace` crate is that on OSX the crates.io crate enables the
`coresymbolication` feature by default. This feature, however, uses
private internal APIs that aren't published for OSX. While they provide
more accurate backtraces this isn't appropriate for libstd distributed
as a binary, so libstd's dependency on the `backtrace` crate explicitly
disables this feature and forces OSX to use `libbacktrace` as a
symbolication strategy.
The long-term goal of this refactoring is to eventually move us towards
a world where we can drop `libbacktrace` entirely and simply use Gimli
and the surrounding crates for backtrace support. That's still aways off
but hopefully will much more easily enabled by having the source of
truth for backtraces live in crates.io!
Procedurally if we go forward with this I'd like to transfer the
`backtrace-rs` crate to the rust-lang GitHub organization as well, but I
figured I'd hold off on that until we get closer to merging.
Add implementations of last in terms of next_back on a bunch of DoubleEndedIterators
Provided a `DoubleEndedIterator` has finite length, `Iterator::last` is equivalent to `DoubleEndedIterator::next_back`. But searching forwards through the iterator when it's unnecessary is obviously not good for performance. I ran into this on one of the collection iterators.
I tried adding appropriate overloads for a bunch of the iterator adapters like filter, map, etc, but I ran into a lot of type inference failures after doing so.
The other interesting case is what to do with `Repeat`. Do we consider it part of the contract that `Iterator::last` will loop forever on it? The docs do say that the iterator will be evaluated until it returns None. This is also relevant for the adapters, it's trivially easy to observe whether a `Map` adapter invoked its closure a zillion times or just once for the last element.
This renames `std::io::IoVec` to `std::io::IoSlice` and
`std::io::IoVecMut` to `std::io::IoSliceMut`, and stabilizes
`std::io::IoSlice`, `std::io::IoSliceMut`,
`std::io::Read::read_vectored`, and `std::io::Write::write_vectored`.
Closes#58452
std: Add `{read,write}_vectored` for more types
This commit implements the `{read,write}_vectored` methods on more types
in the standard library, namely:
* `std::fs::File`
* `std::process::ChildStd{in,out,err}`
* `std::io::Std{in,out,err}`
* `std::io::Std{in,out,err}Lock`
* `std::io::Std{in,out,err}Raw`
Where supported the OS implementations hook up to native support,
otherwise it falls back to the already-defaulted implementation.
This commit implements the `{read,write}_vectored` methods on more types
in the standard library, namely:
* `std::fs::File`
* `std::process::ChildStd{in,out,err}`
* `std::io::Std{in,out,err}`
* `std::io::Std{in,out,err}Lock`
* `std::io::Std{in,out,err}Raw`
Where supported the OS implementations hook up to native support,
otherwise it falls back to the already-defaulted implementation.
This commit removes usage of `Once` from the internal implementation of
time utilities on OSX and Windows. It turns out that we accidentally hit
a deadlock today (#59020) via events that look like:
* A thread invokes `park_timeout`
* Internally, only on OSX, `park_timeout` calls `Instant::elapsed`
* Inside of `Instant::elapsed` on OSX we enter a `Once` to initialize
global timer data
* Inside of `Once`, it attempts to `park`
This means on the same stack frame, when there's contention, we're
calling `park` from inside `park_timeout`, causing a deadlock!
The solution implemented in this commit was to remove usage of `Once`
and instead just do a small dance with atomics. There's no real need we
need to guarantee that the global information is only learned once, only
that it's only *stored* once. This implementation may have multiple
threads invoke `mach_timebase_info`, but only one will store the global
information which will amortize the cost for all other threads.
A similar fix has been applied to windows to be uniform across our
implementations, but looking at the code on Windows no deadlock was
possible. This is purely just a consistency update for Windows and in
theory a slightly leaner implementation.
Closes#59020
Set secure flags when opening a named pipe on Windows
Fixes https://github.com/rust-lang/rust/issues/42036, see also the previous attempt in https://github.com/rust-lang/rust/pull/44556.
Whether this is correct depends on if it is somehow possible to create a symlink to a named pipe, outside the named pipe filesystem (NPFS). But as far as I can tell that should be impossible.
Also fixes that `security_qos_flags(SECURITY_ANONYMOUS)` does not set the `SECURITY_SQOS_PRESENT` flag, and the incorrect documentation about the default value of `security_qos_flags`.
Add vectored read and write support
This functionality has lived for a while in the tokio ecosystem, where
it can improve performance by minimizing copies.
r? @alexcrichton
