Windows: Use `FindFirstFileW` for getting the metadata of locked system files
Fixes#96980
Usually opening a file handle with access set to metadata only will always succeed, even if the file is locked. However some special system files, such as `C:\hiberfil.sys`, are locked by the system in a way that denies even that. So as a fallback we try reading the cached metadata from the directory.
Note that the test is a bit iffy. I don't know if `hiberfil.sys` actually exists in the CI.
r? rust-lang/libs
* Reduce duplicate impls; show only the `fn (T)` and include a sentence
saying that there exists up to twelve of them.
* Show `Copy` and `Clone`.
* Show auto traits like `Send` and `Sync`, and blanket impls like `Any`.
Implement `fmt::Write` for `OsString`
This allows to format into an `OsString` without unnecessary
allocations. E.g.
```
let mut temp_filename = path.into_os_string();
write!(&mut temp_filename, ".tmp.{}", process::id());
```
Stabilize `core::ffi::CStr`, `alloc::ffi::CString`, and friends
Stabilize the `core_c_str` and `alloc_c_string` feature gates.
Change `std::ffi` to re-export these types rather than creating type
aliases, since they now have matching stability.
Stabilize the `core_c_str` and `alloc_c_string` feature gates.
Change `std::ffi` to re-export these types rather than creating type
aliases, since they now have matching stability.
Add `struct FileTimes` to contain the relevant file timestamps, since
most platforms require setting all of them at once. (This also allows
for future platform-specific extensions such as setting creation time.)
Add `File::set_file_time` to set the timestamps for a `File`.
Implement the `sys` backends for UNIX, macOS (which needs to fall back
to `futimes` before macOS 10.13 because it lacks `futimens`), Windows,
and WASI.
Stabilize `core::ffi:c_*` and rexport in `std::ffi`
This only stabilizes the base types, not the non-zero variants, since
those have their own separate tracking issue and have not gone through
FCP to stabilize.
This only stabilizes the base types, not the non-zero variants, since
those have their own separate tracking issue and have not gone through
FCP to stabilize.
We have `File::create` for creating a file or opening an existing file,
but the secure way to guarantee creating a new file requires a longhand
invocation via `OpenOptions`.
Add `File::create_new` to handle this case, to make it easier for people
to do secure file creation.
Inline Windows `OsStrExt::encode_wide`
User crates currently produce much more code than necessary because the optimizer fails to make assumptions about this method.
Implement ExitCodeExt for Windows
Fixes#97914
### Motivation:
On Windows it is common for applications to return `HRESULT` (`i32`) or `DWORD` (`u32`) values. These stem from COM based components ([HRESULTS](https://docs.microsoft.com/en-us/windows/win32/api/objbase/nf-objbase-coinitialize)), Win32 errors ([GetLastError](https://docs.microsoft.com/en-us/windows/win32/api/errhandlingapi/nf-errhandlingapi-getlasterror)), GUI applications ([WM_QUIT](https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-quit)) and more. The newly stabilized `ExitCode` provides an excellent fit for propagating these values, because `std::process::exit` does not run deconstructors which can result in errors. However, `ExitCode` currently only implements `From<u8> for ExitCode`, which disallows the full range of `i32`/`u32` values. This pull requests attempts to address that shortcoming by providing windows specific extensions that accept a `u32` value (which covers all possible `HRESULTS` and Win32 errors) analog to [ExitStatusExt::from_raw](https://doc.rust-lang.org/std/os/windows/process/trait.ExitStatusExt.html#tymethod.from_raw).
This was also intended by the original Stabilization https://github.com/rust-lang/rust/pull/93840#issue-1129209143= as pointed out by ``@eggyal`` in https://github.com/rust-lang/rust/issues/97914#issuecomment-1151076755:
> Issues around platform specific representations: We resolved this issue by changing the return type of report from i32 to the opaque type ExitCode. __That way we can change the underlying representation without affecting the API, letting us offer full support for platform specific exit code APIs in the future.__
[Emphasis added]
### API
```rust
/// Windows-specific extensions to [`process::ExitCode`].
///
/// This trait is sealed: it cannot be implemented outside the standard library.
/// This is so that future additional methods are not breaking changes.
#[stable(feature = "windows_process_exit_code_from", since = "1.63.0")]
pub trait ExitCodeExt: Sealed {
/// Creates a new `ExitCode` from the raw underlying `u32` return value of
/// a process.
#[stable(feature = "windows_process_exit_code_from", since = "1.63.0")]
fn from_raw(raw: u32) -> Self;
}
#[stable(feature = "windows_process_exit_code_from", since = "1.63.0")]
impl ExitCodeExt for process::ExitCode {
fn from_raw(raw: u32) -> Self {
process::ExitCode::from_inner(From::from(raw))
}
}
```
### Misc
I apologize in advance if I misplaced any attributes regarding stabilzation, as far as I learned traits are insta-stable so I chose to make them stable. If this is an error, please let me know and I'll correct it. I also added some additional machinery to make it work, analog to [ExitStatus](https://doc.rust-lang.org/std/process/struct.ExitStatus.html#).
EDIT: Proposal: https://github.com/rust-lang/libs-team/issues/48
