alongside the typical msghdr struct, Zig has added a msghdr_const
type that can be used with sendmsg which allows const data to
be provided. I believe that data pointed to by the iov and control
fields in msghdr are also left unmodified, in which case they can
be marked const as well.
Rename all references of sparcv9 to sparc64, to make Zig align more with
other projects. Also, added new function to convert glibc arch name to Zig
arch name, since it refers to the architecture as sparcv9.
This is based on the suggestion by @kubkon in PR 11847.
(https://github.com/ziglang/zig/pull/11487#pullrequestreview-963761757)
Currently, the new API will only be available on macOS with
the intention of adding more POSIX systems to it incrementally
(such as Linux, etc.).
Changes:
* add `posix_spawn` wrappers in a separate container in
`os/posix_spawn.zig`
* rewrite `ChildProcess.spawnPosix` using `posix_spawn` targeting macOS
as `ChildProcess.spawnMacos`
* introduce a `posix_spawn` specific `std.c.waitpid` wrapper which
does return an error in case the child process failed to exec - this
is required for any process that was spawned using `posix_spawn`
mechanism as, by definition, the errors returned by `posix_spawn`
routine cover only the `fork`-equivalent; `pre-exec()` and `exec()`
steps are covered by a catch-all error `ECHILD` returned by `waitpid`
on unsuccessful execution, e.g., no such file error, etc.
The libc interface uses `stat` instead of `stat64` struct.
This fixes, among other things, `zig fmt` accidentally setting the
formatted file's permission to 000.
This adds a special CWD file descriptor, AT.FDCWD (-2), to refer to the
current working directory. The `*at(...)` functions look for this and
resolve relative paths against the stored CWD. Absolute paths are
dynamically matched against the stored Preopens.
"os.initPreopensWasi()" must be called before std.os functions will
resolve relative or absolute paths correctly. This is asserted at
runtime.
Support has been added for: `open`, `rename`, `mkdir`, `rmdir`, `chdir`,
`fchdir`, `link`, `symlink`, `unlink`, `readlink`, `fstatat`, `access`,
and `faccessat`.
This also includes limited support for `getcwd()` and `realpath()`.
These return an error if the CWD does not correspond to a Preopen with
an absolute path. They also do not currently expand symlinks.
Adds the `tcflag_t` type to the termios constants.
This is made to allow bitwise operations on the termios
constants without an integer cast, e.g.:
```zig
var raw = try std.os.tcgetattr(std.os.STDIN_FILENO);
raw.lflag &= std.os.linux.ECHO | std.os.linux.ICANON;
```
instead of
```zig
var raw = try std.os.tcgetattr(std.os.STDIN_FILENO);
raw.lflag &= ~@intCast(u32, std.os.linux.ECHO | std.os.linux.ICANON);
```
Contributes to #10181
