Previously, the `guard::init()` and `guard::current()` functions were
returning a `usize` address representing the top of the stack guard,
respectively for the main thread and for spawned threads. The `SIGSEGV`
handler on `unix` targets checked if a fault was within one page below
that address, if so reporting it as a stack overflow.
Now `unix` targets report a `Range<usize>` representing the guard
memory, so it can cover arbitrary guard sizes. Non-`unix` targets which
always return `None` for guards now do so with `Option<!>`, so they
don't pay any overhead.
For `linux-gnu` in particular, the previous guard upper-bound was
`stackaddr + guardsize`, as the protected memory was *inside* the stack.
This was a glibc bug, and starting from 2.27 they are moving the guard
*past* the end of the stack. However, there's no simple way for us to
know where the guard page actually lies, so now we declare it as the
whole range of `stackaddr ± guardsize`, and any fault therein will be
called a stack overflow. This fixes#47863.
Redox - Implement rename using new system call
This does the following:
- Update syscall module to match upstream
- Implement rename using new system call
- Make readlink and symlink utilize O_CLOEXEC
- Make readlink and symlink not leave dangling file handles on failure
Provides the following conversion implementations:
* `From<`{`CString`,`&CStr`}`>` for {`Arc`,`Rc`}`<CStr>`
* `From<`{`OsString`,`&OsStr`}`>` for {`Arc`,`Rc`}`<OsStr>`
* `From<`{`PathBuf`,`&Path`}`>` for {`Arc`,`Rc`}`<Path>`
Redox: Use futex timeout to implement CondVar::wait_timeout
`CondVar::wait_timeout` is implemented by supplying a `TimeSpec` pointer to `futex`. In addition, all calls to `unimplemented!()` have been removed from the Redox `sys` module.
Related to https://github.com/rust-lang/rust/pull/45892
This commit removes usage of the `libc` crate in "portable" modules like
those at the top level and `sys_common`. Instead common types like `*mut
u8` or `u32` are used instead of `*mut c_void` or `c_int` as well as
switching to platform-specific functions like `sys::strlen` instead of
`libc::strlen`.
This commit moves the `f32::cmath` and `f64::cmath` modules into the
`sys` module. Note that these are not publicly exported modules, simply
implementation details. These modules are already platform-specific with
shims on MSVC and this is mostly just a reflection of that reality. This
should also help cut down on `#[cfg]` traffic if platforms are brought on
which don't directly support these functions.
This commit removes the reexport of `EBADF_ERR` as a constant from
libstd's portability facade, instead opting for a platform-specific
function that specifically queries an `io::Error`. Not all platforms may
have a constant for this, so it makes the intent a little more clear
that a code need not be supplied, just an answer to a query.
This commit removes the `rand` crate from the standard library facade as
well as the `__rand` module in the standard library. Neither of these
were used in any meaningful way in the standard library itself. The only
need for randomness in libstd is to initialize the thread-local keys of
a `HashMap`, and that unconditionally used `OsRng` defined in the
standard library anyway.
The cruft of the `rand` crate and the extra `rand` support in the
standard library makes libstd slightly more difficult to port to new
platforms, namely WebAssembly which doesn't have any randomness at all
(without interfacing with JS). The purpose of this commit is to clarify
and streamline randomness in libstd, focusing on how it's only required
in one location, hashmap seeds.
Note that the `rand` crate out of tree has almost always been a drop-in
replacement for the `rand` crate in-tree, so any usage (accidental or
purposeful) of the crate in-tree should switch to the `rand` crate on
crates.io. This then also has the further benefit of avoiding
duplication (mostly) between the two crates!
Add the libstd-modifications needed for the L4Re target
This commit adds the needed modifications to compile the std crate for the L4 Runtime environment (L4Re).
A target for the L4Re was introduced in commit: c151220a84
In many aspects implementations for linux also apply for the L4Re microkernel.
Some uncommon characteristics had to be resolved:
* L4Re has no network funktionality
* L4Re has a maximum stacksize of 1Mb for threads
* L4Re has no uid or gid
Co-authored-by: Sebastian Humenda <sebastian.humenda@tu-dresden.de>
Make backtraces work on Redox, copying Unix implementation
The `backtrace/` directory here is the same as the Unix one, except for adding an implementation of `get_executable_filename`.
Expose all OS-specific modules in libstd doc.
1. Uses the special `--cfg dox` configuration passed by rustbuild when running `rustdoc`. Changes the `#[cfg(platform)]` into `#[cfg(any(dox, platform))]` so that platform-specific API are visible to rustdoc.
2. Since platform-specific implementations often won't compile correctly on other platforms, `rustdoc` is changed to apply `everybody_loops` to the functions during documentation and doc-test harness.
3. Since platform-specific code are documented on all platforms now, it could confuse users who found a useful API but is non-portable. Also, their examples will be doc-tested, so must be excluded when not testing on the native platform. An undocumented attribute `#[doc(cfg(...))]` is introduced to serve the above purposed.
Fixes#24658 (Does _not_ fully implement #1998).
