Add a `std::io::read_to_string` function
I recognize that you're usually supposed to open an issue first, but the
implementation is very small so it's okay if this is closed and it was 'wasted
work' :)
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The equivalent of `std::fs::read_to_string`, but generalized to all
`Read` impls.
As the documentation on `std::io::read_to_string` says, the advantage of
this function is that it means you don't have to create a variable first
and it provides more type safety since you can only get the buffer out
if there were no errors. If you use `Read::read_to_string`, you have to
remember to check whether the read succeeded because otherwise your
buffer will be empty.
It's friendlier to newcomers and better in most cases to use an explicit
return value instead of an out parameter.
Add missing methods to unix ExitStatusExt
These are the methods corresponding to the remaining exit status examination macros from `wait.h`. `WCOREDUMP` isn't in SuS but is it is very standard. I have not done portability testing to see if this builds everywhere, so I may need to Do Something if it doesn't.
There is also a bugfix and doc improvement to `.signal()`, and an `.into_raw()` accessor.
This would fix#73128 and fix#73129. Please let me know if you like this direction, and if so I will open the tracking issue and so on.
If this MR goes well, I may tackle #73125 next - I have an idea for how to do it.
This is not particularly pretty but the current situation is a mess
and I don't think I'm making it significantly worse.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
As discussed in #79982.
I think the "new interfaces", ie the new trait and impl, must be
insta-stable. This seems OK because we are, in fact, adding a new
restriction to the stable API.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
We need to be clear that this never returns WSTOPSIG. That is, if
WIFSTOPPED, the return value is None.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
A unix wait status can contain, at least, exit statuses, termination
signals, and stop signals.
WTERMSIG is only valid if WIFSIGNALED.
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html
It will not be easy to experience this bug with `Command`, because
that doesn't pass WUNTRACED. But you could make an ExitStatus
containing, say, a WIFSTOPPED, from a call to one of the libc wait
functions.
(In the WIFSTOPPED case, there is WSTOPSIG. But a stop signal is
encoded differently to a termination signal, so WTERMSIG and WSTOPSIG
are by no means the same.)
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
use Once instead of Mutex to manage capture resolution
For #78299
This allows us to return borrows of the captured backtrace frames that are tied to a borrow of the Backtrace itself, instead of to some short-lived Mutex guard.
We could alternatively share `&Mutex<Capture>`s and lock on-demand, but then we could potentially forget to call `resolve()` before working with the capture. It also makes it semantically clearer what synchronization is needed on the capture.
cc `@seanchen1991` `@rust-lang/project-error-handling`
Fix safety comment
The size assertion in the comment was inverted compared to the code. After fixing that the implication that `(new_size >= old_size) => new_size != 0` still doesn't hold so explain why `old_size != 0` at this point.
Rustdoc: Fix macros 2.0 and built-in derives being shown at the wrong path
Fixes#74355
- ~~waiting on author + draft PR since my code ought to be cleaned up _w.r.t._ the way I avoid the `.unwrap()`s:~~
- ~~dummy items may avoid the first `?`,~~
- ~~but within the module traversal some tests did fail (hence the second `?`), meaning the crate did not possess the exact path of the containing module (`extern` / `impl` blocks maybe? I'll look into that).~~
r? `@jyn514`
Optimize away some path lookups in the generic `fs::copy` implementation
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
Stabilize slice::strip_prefix and slice::strip_suffix
These two methods are useful. The corresponding methods on `str` are already stable.
I believe that stablising these now would not get in the way of, in the future, extending these to take a richer pattern API a la `str`'s patterns.
Tracking PR: #73413. I also have an outstanding PR to improve the docs for these two functions and the corresponding ones on `str`: #75078
I have tried to follow the [instructions in the dev guide](https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#stabilization-pr). The part to do with `compiler/rustc_feature` did not seem applicable. I assume that's because these are just library features, so there is no corresponding machinery in rustc.
The size assertion in the comment was inverted compared to the code. After fixing that the implication that `(new_size >= old_size) => new_size != 0` still doesn't hold so explain why `old_size != 0` at this point.
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
The heading style for `std::prelude` is to be consistent with the
headings for `std` and `core`: `# The Rust Standard Library` and
`# The Rust Core Library`, respectively.
This allows us to return borrows of the captured backtrace frames
that are tied to a borrow of the Backtrace itself, instead of to
some short-lived Mutex guard.
It also makes it semantically clearer what synchronization is needed
on the capture.
slightly more typed interface to panic implementation
The panic payload is currently being passed around as a `usize`. However, it actually is a pointer, and the involved types are available on all ends of this API, so I propose we use the proper pointer type to avoid some casts. Avoiding int-to-ptr casts also makes this code work with `miri -Zmiri-track-raw-pointers`.
