Atomic as_mut_ptr
I encountered the following pattern a few times: In Rust we use some atomic type like `AtomicI32`, and an FFI interface exposes this as `*mut i32` (or some similar `libc` type).
It was not obvious to me if a just transmuting a pointer to the atomic was acceptable, or if this should use a cast that goes through an `UnsafeCell`. See https://github.com/rust-lang/rust/issues/66136#issuecomment-557802477
Transmuting the pointer directly:
```rust
let atomic = AtomicI32::new(1);
let ptr = &atomic as *const AtomicI32 as *mut i32;
unsafe {
ffi(ptr);
}
```
A dance with `UnsafeCell`:
```rust
let atomic = AtomicI32::new(1);
unsafe {
let ptr = (&*(&atomic as *const AtomicI32 as *const UnsafeCell<i32>)).get();
ffi(ptr);
}
```
Maybe in the end both ways could be valid. But why not expose a direct method to get a pointer from the standard library?
An `as_mut_ptr` method on atomics can be safe, because only the use of the resulting pointer is where things can get unsafe. I documented its use for FFI, and "Doing non-atomic reads and writes on the resulting integer can be a data race."
The standard library could make use this method in a few places in the WASM module.
cc @RalfJung as you answered my original question.
Format libstd with rustfmt
(Same strategy as #66691.)
This commit applies rustfmt with rust-lang/rust's default settings to files in src/libstd *that are not involved in any currently open PR* to minimize merge conflicts, and are not part of libstd/os (#66818) or libstd/sys (#66819). 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 -name '*.rs' \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ rg libstd outstanding_files | xargs git checkout --
Repeating this process several months apart should get us coverage of most of the rest of libstd.
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
Format libstd/sys with rustfmt
(Same strategy as #66691.)
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
This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd *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 -name '*.rs' \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ rg libstd outstanding_files | xargs git checkout --
Repeating this process several months apart should get us coverage of
most of the rest of libstd.
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
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
This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd/os *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/os -name '*.rs' \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ rg libstd/os 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
Panic machinery comments and tweaks
This is mostly more comments, but I also renamed some things:
* `BoxMeUp::box_me_up` is not terribly descriptive, and since this is a "take"-style method (the argument is `&mut self` but the return type is fully owned, even though you can't tell from the type) I chose a name involving "take".
* `continue_panic_fmt` was very confusing as it was entirely unclear what was being continued -- for some time I thought "continue" might be the same as "resume" for a panic, but that's something entirely different. So I renamed this to `begin_panic_handler`, matching the `begin_panic*` theme of the other entry points.
r? @Dylan-DPC @SimonSapin
Fallback to .init_array when no arguments are available on glibc Linux
Linux is one of the only platforms where `std::env::args` doesn't work in a cdylib.
Add unix::process::CommandExt::arg0
This allows argv[0] to be overridden on the executable's command-line. This also makes the program
executed independent of argv[0].
Does Fuchsia have the same semantics? I'm assuming so.
Addresses: #66510
introduce benchmarks of HashSet operations
To avoid goofs such as corrected by #66280, I added benchmarks of binary HashSet operations.
Due to the fact x.py keeps recompiling the whole shebang (or at least a big part of it) whenever you touch the test code, and because piling up all tests in one file does not strike me as future proof, I tried moving the hash benches to the separate place they are for liballoc/collections/btree. But it turns out that, in a cleaned checkout, x.py still recompiles the whole shebang whenever you touch the test code (PS or when you add or delete any irrelevant file). So I'm not going to add more tests, and I doubt others will, and these tests have proven their point already, so this PR is kind of pointless
This allows argv[0] to be overridden on the executable's command-line. This also makes the program
executed independent of argv[0].
Does Fuchsia have the same semantics?
Addresses: #66510
Centralize panic macro documentation
This is just the main commit from #61511 (which got closed because the author didn't reply) cherry-picked on the current master. Building `core` and `std` on this branch in stage 1 succeeded, which I thinks means the issues from the previous PR should be gone (but let's see what CI says).
Remove some stack frames from `.async` calls
The `Context` argument is currently smuggled through TLS for
async-generated futures. The current infrastructure is closure-based,
and results in an extra 6 stack frames when .awaiting an async-generated
future!
```
12: foo::async_b::{{closure}}
at src/main.rs:10
13: <std::future::GenFuture<T> as core::future::future::Future>::poll::{{closure}}
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:43
14: std::future::set_task_context
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:79
15: <std::future::GenFuture<T> as core::future::future::Future>::poll
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:43
16: std::future::poll_with_tls_context::{{closure}}
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:121
17: std::future::get_task_context
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:111
18: std::future::poll_with_tls_context
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:121
19: foo::async_a::{{closure}}
at src/main.rs:6
```
While the long (medium?) term solution is to remove the use of TLS
entirely, we can improve things a bit in the meantime. In particular,
this commit does 2 things:
1. `get_task_context` has been inlined into `poll_with_tls_context`,
removing 2 frames (16 and 17 above).
2. `set_task_context` now returns a guard type that resets the TLS
rather than taking a closure, removing 2 frames (13 and 14 above).
We can also remove frame 18 by removing `poll_with_tls_context` in favor
of a `get_task_context` function which returns a guard, but that
requires adjusting the code generated for .await, so I've left that off
for now.
rename Error::iter_chain() and remove Error::iter_sources()
~~Rename~~
* ~~Error::iter_chain() -> Error::chained()~~
* ~~Error::iter_sources() -> Error::ancestors()~~
* ~~ErrorIter -> Chained and Ancestors~~
according to
https://github.com/rust-lang/rust/issues/58520#issuecomment-527704110
Tracker:
https://github.com/rust-lang/rust/issues/58520
Edit:
Rename
* Error::iter_chain() -> Error::chained()
* ErrorIter -> Chain
So, it seems, that even Path::ancestors() includes itself. So, to avoid confusion and simplify it more, I reduced PR #65557 to only have `chained` and `Chain`.
Rationale:
1. Such iterators are helpful. They should better be stabilized sooner than later.
1. self should be included. It is easy to .skip(1) it. Not including self is harmful because it is harder to add self to the iterator than to remove it.
1. The chosen name should be telling and reflect the fact that self is included. `.chained()` was chosen in honor of error-chain and because the iterator iterates over the chain of errors that is somehow included in self.
1. The resulting iterator is named `Chain` because the `error::Chain` is what we want to have.
Fix broken links in Ipv4Addr::is_benchmarking docs
[The documentation for `Ipv4Addr::is_benchmarking`](https://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_benchmarking) is correct — it has the right RFC number — but the Markdown links are broken. Looks like a copy-and-paste error and a typo.
This PR fixes the links to make them clickable.
The `Context` argument is currently smuggled through TLS for
async-generated futures. The current infrastructure is closure-based,
and results in an extra 6 stack frames when .awaiting an async-generated
future!
```
12: foo::async_b::{{closure}}
at src/main.rs:10
13: <std::future::GenFuture<T> as core::future::future::Future>::poll::{{closure}}
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:43
14: std::future::set_task_context
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:79
15: <std::future::GenFuture<T> as core::future::future::Future>::poll
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:43
16: std::future::poll_with_tls_context::{{closure}}
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:121
17: std::future::get_task_context
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:111
18: std::future::poll_with_tls_context
at /rustc/4560ea788cb760f0a34127156c78e2552949f734/src/libstd/future.rs:121
19: foo::async_a::{{closure}}
at src/main.rs:6
```
While the long (medium?) term solution is to remove the use of TLS
entirely, we can improve things a bit in the meantime. In particular,
this commit does 2 things:
1. `get_task_context` has been inlined into `poll_with_tls_context`,
removing 2 frames (16 and 17 above).
2. `set_task_context` now returns a guard type that resets the TLS
rather than taking a closure, removing 2 frames (13 and 14 above).
We can also remove frame 18 by removing `poll_with_tls_context` in favor
of a `get_task_context` function which returns a guard, but that
requires adjusting the code generated for .await, so I've left that off
for now.
