Rollup of 4 pull requests
Successful merges:
- #98235 (Drop magic value 3 from code)
- #98267 (Don't omit comma when suggesting wildcard arm after macro expr)
- #98276 (Mention formatting macros when encountering `ArgumentV1` method in const)
- #98296 (Add a link to the unstable book page on Generator doc comment)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add a link to the unstable book page on Generator doc comment
This makes it easier to jump into the Generator section on the unstable book.
Signed-off-by: Yuki Okushi <jtitor@2k36.org>
Mention formatting macros when encountering `ArgumentV1` method in const
Also open to just closing this if it's overkill. There are a lot of other distracting error messages around, so maybe it's not worth fixing just this one.
Fixes#93665
Don't omit comma when suggesting wildcard arm after macro expr
* Also adds `Span::eq_ctxt` to consolidate the various usages of `span.ctxt() == other.ctxt()`
* Also fixes an unhygenic usage of spans which caused the suggestion to render weirdly when we had one arm match in a macro
* Also always suggests a comma (i.e. even after a block) if we're rendering a wildcard arm in a single-line match (looks prettier 🌹)
Fixes#94866
Drop magic value 3 from code
Magic value 3 is used to create state for a yield point. It is in fact
the number of reserved variants.
Lift RESERVED_VARIANTS out to module scope and use it instead.
Include ForeignItem when visiting types for WF check
Addresses Issue 95665 by including `hir::Node::ForeignItem` as a valid
type to visit in `diagnostic_hir_wf_check`.
Fixes#95665
Document Rust's stance on `/proc/self/mem`
Add documentation to `std::os::unix::io` describing Rust's stance on
`/proc/self/mem`, treating it as an external entity which is outside
the scope of Rust's safety guarantees.
`Stdio::makes_pipe`
Wrappers around `std::process::Command` may want to be able to override pipe creation. However, [`std::process::Stdio`](https://doc.rust-lang.org/std/process/struct.Stdio.html) is opaque so there's no way to tell if `Command` was told to create new pipes or not.
This is in some ways a more generic (and cross-platform) alternative to #97149. However, unlike that feature, this comes with the price of the user needing to actually create their own pipes rather than reusing the std one. So I think it stands (or not) on its own.
# Example
```rust
#![feature(stdio_makes_pipe)]
use std::process::Stdio;
let io = Stdio::piped();
assert_eq!(io.makes_pipe(), true);
```
Windows: `CommandExt::async_pipes`
Discussed in https://github.com/tokio-rs/tokio/issues/4670 was the need for third party crates to be able to force `process::Command::spawn` to create pipes as async.
This implements the suggestion for a `async_pipes` method that gives third party crates that option.
# Example:
```rust
use std::process::{Command, Stdio};
Command::new("cmd")
.async_pipes(true)
.stdin(Stdio::piped())
.stdout(Stdio::piped())
.stderr(Stdio::piped())
.spawn()
.unwrap();
```
Fix the generator example for `pin!()`
The previous generator example is not actually self-referential, since the reference is created after the yield.
CC #93178 (tracking issue)
Magic value 3 is used to create state for a yield point. It is in fact
the number of reserved variants.
Lift RESERVED_VARIANTS out to module scope and use it instead.
Fix pretty printing of empty bound lists in where-clause
Repro:
```rust
macro_rules! assert_item_stringify {
($item:item $expected:literal) => {
assert_eq!(stringify!($item), $expected);
};
}
fn main() {
assert_item_stringify! {
fn f<'a, T>() where 'a:, T: {}
"fn f<'a, T>() where 'a:, T: {}"
}
}
```
Previously this assertion would fail because rustc renders the where-clause as `where 'a, T` which is invalid syntax.
This PR makes the above assertion pass.
This bug also affects `-Zunpretty=expanded`. The intention is for that to emit syntactically valid code, but the buggy output is not valid Rust syntax.
```console
$ rustc <(echo "fn f<'a, T>() where 'a:, T: {}") -Zunpretty=expanded
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use ::std::prelude::rust_2015::*;
#[macro_use]
extern crate std;
fn f<'a, T>() where 'a, T {}
```
```console
$ rustc <(echo "fn f<'a, T>() where 'a:, T: {}") -Zunpretty=expanded | rustc -
error: expected `:`, found `,`
--> <anon>:7:23
|
7 | fn f<'a, T>() where 'a, T {}
| ^ expected `:`
```
Make missing argument placeholder more obvious that it's a placeholder
Use `/* ty */` instead of `{ty}`, since people might be misled into thinking that this is valid syntax, and not just a diagnostic placeholder.
Fixes#96880
Fix `SourceScope` for `if let` bindings.
Fixes#97799.
I'm not sure how to test this properly, is there any way to observe the difference in behavior apart from `ui` tests? I'm worried that they would be overlooked in the case of a regression.
Make debug_triple depend on target json file content rather than file path
This ensures that changes to target json files will force a recompilation. And more importantly that moving the files doesn't force a recompilation.
This should fix https://github.com/Rust-for-Linux/linux/issues/792 (cc ``@ojeda)``
Stabilize `Path::try_exists()` and improve doc
This stabilizes the `Path::try_exists()` method which returns
`Result<bool, io::Error>` instead of `bool` allowing handling of errors
unrelated to the file not existing. (e.g permission errors)
Along with the stabilization it also:
* Warns that the `exists()` method is error-prone and suggests to use
the newly stabilized one.
* Suggests it instead of `metadata()` to handle errors.
* Mentions TOCTOU bugs to avoid false assumption that `try_exists()` is
completely safe fixed version of `exists()`.
* Renames the feature of still-unstable `std::fs::try_exists()` to
`fs_try_exists` to avoid name conflict.
The tracking issue #83186 remains open to track `fs_try_exists`.
Add `core::mem::copy` to complement `core::mem::drop`.
This is useful for combinators. I didn't add `clone` since you can already
use `Clone::clone` in its place; copy has no such corresponding function.
Make "Assemble stage1 compiler" orders of magnitude faster (take 2)
This used to take upwards of 5 seconds for me locally. I found that the culprit was copying the downloaded LLVM shared object:
```
[22:28:03] Install "/home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/ci-llvm/lib/libLLVM-14-rust-1.62.0-nightly.so" to "/home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib/libLLVM-14-rust-1.62.0-nightly.so"
[22:28:09] c Sysroot { compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu(x86_64-unknown-linux-gnu) } }
```
It turned out that `install()` used full copies unconditionally. Change it to try using a hard-link before falling back to copying.
- Panic if we generate a symbolic link in a tarball
- Change install to use copy internally, like in my previous PR
- Change copy to dereference symbolic links, which avoids the previous regression in #96803.
I also took the liberty of fixing `x dist llvm-tools` to work even if you don't call `x build` previously.
This used to take upwards of 5 seconds for me locally. I found that the
culprit was copying the downloaded LLVM shared object:
```
[22:28:03] Install "/home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/ci-llvm/lib/libLLVM-14-rust-1.62.0-nightly.so" to "/home/jnelson/rust-lang/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib/libLLVM-14-rust-1.62.0-nightly.so"
[22:28:09] c Sysroot { compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu(x86_64-unknown-linux-gnu) } }
```
It turned out that `install()` used full copies unconditionally. Change
it to use `copy()` internally, which uses hard links instead when
available.
Note that this has a change in behavior: Installing a file will also
change permissions on the source, not just the destination, if hard
links are used.
To avoid changing the behavior on symlinks for existing code, I
introduce a new function `copy_internal` which only dereferences
symlinks when told to do so.
