- Affects the following functions:
+ `std.fs.Dir.readLinkW`
+ `std.os.windows.ReadLink`
+ `std.os.windows.ntToWin32Namespace`
+ `std.posix.readlinkW`
+ `std.posix.readlinkatW`
Each of these functions (except `ntToWin32Namespace`) took WTF-16 as input and would output WTF-8, which makes optimal buffer re-use difficult at callsites and could force unnecessary WTF-16 <-> WTF-8 conversion during an intermediate step.
The functions have been updated to output WTF-16, and also allow for the path and the output to re-use the same buffer (i.e. in-place modification), which can reduce the stack usage at callsites. For example, all of `std.fs.Dir.readLink`/`readLinkZ`/`std.posix.readlink`/`readlinkZ`/`readlinkat`/`readlinkatZ` have had their stack usage reduced by one PathSpace struct (64 KiB) when targeting Windows.
The new `ntToWin32Namespace` takes an output buffer and returns a slice from that instead of returning a PathSpace, which is necessary to make the above possible.
The reasoning in the comment deleted by this commit no longer applies, since that same benefit can be obtained by using OpenFile with `.filter = .any`.
Also removes a stray debug.print
Apple's own headers and tbd files prefer to think of Mac Catalyst as a distinct
OS target. Earlier, when DriverKit support was added to LLVM, it was represented
a distinct OS. So why Apple decided to only represent Mac Catalyst as an ABI in
the target triple is beyond me. But this isn't the first time they've ignored
established target triple norms (see: armv7k and aarch64_32) and it probably
won't be the last.
While doing this, I also audited all Darwin OS prongs throughout the codebase
and made sure they cover all the tags.
Unfortunately this can't be implemented "above the vtable" because
various operating systems don't provide low level DNS resolution
primitives such as just putting the list of nameservers in a file.
Without libc on Linux it works great though!
Anyway this also changes the API to be based on Io.Queue. By using a
large enough buffer, reusable code can be written that does not require
concurrent, yet takes advantage of responding to DNS queries as they
come in. I sketched out a new implementation of `HostName.connect` to
demonstrate this, but it will require an additional API (`Io.Select`) to
be implemented in a future commit.
This commit also introduces "uncancelable" variants for mutex locking,
waiting on a condition, and putting items into a queue.
There is no straightforward way for the Zig team to access the Solaris system
headers; to do this, one has to create an Oracle account, accept their EULA to
download the installer ISO, and finally install it on a machine or VM. We do not
have to jump through hoops like this for any other OS that we support, and no
one on the team has expressed willingness to do it.
As a result, we cannot audit any Solaris contributions to std.c or other
similarly sensitive parts of the standard library. The best we would be able to
do is assume that Solaris and illumos are 100% compatible with no way to verify
that assumption. But at that point, the solaris and illumos OS tags would be
functionally identical anyway.
For Solaris especially, any contributions that involve APIs introduced after the
OS was made closed-source would also be inherently more risky than equivalent
contributions for other proprietary OSs due to the case of Google LLC v. Oracle
America, Inc., wherein Oracle clearly demonstrated its willingness to pursue
legal action against entities that merely copy API declarations.
Finally, Oracle laid off most of the Solaris team in 2017; the OS has been in
maintenance mode since, presumably to be retired completely sometime in the 2030s.
For these reasons, this commit removes all Oracle Solaris support.
Anyone who still wishes to use Zig on Solaris can try their luck by simply using
illumos instead of solaris in target triples - chances are it'll work. But there
will be no effort from the Zig team to support this use case; we recommend that
people move to illumos instead.
The compile-time check against the minimum version here wasn't appropriate, since it still makes sense to try using FILE_RENAME_INFORMATION_EX even if the minimum version is something like `xp`, since that doesn't rule out the possibility of the compiled code running on Windows 10/11. This compile-time check was doubly bad since the default minimum windows version (`.win10`) was below the `.win10_rs5` that was checked for, so when providing a target like `x86_64-windows-gnu` it'd always rule out using this syscall.
After this commit, we always try using FILE_RENAME_INFORMATION_EX and then let the operating system tell us when some aspect of it is not supported. This allows us to get the benefits of these new syscalls/flags whenever it's actually possible.
The possible error returns were validated experimentally:
- INVALID_PARAMETER is returned when the underlying filesystem is FAT32
- INVALID_INFO_CLASS is returned on Windows 7 when trying to use FileRenameInformationEx/FileDispositionInformationEx
- NOT_SUPPORTED is returned on Windows 10 >= .win10_rs5 when setting a bogus flag value (I used `0x1000`)
This is to help diagnose #25498. We can't use `unexpectedErrno` here,
because `std.posix.munmap` is infallible. So, when the flag is set to
report unexpected errnos, we just call `std.debug.panic` to provide
details instead of doing `unreachable`.
Pushing straight to master after running checks locally; there's no
point waiting for CI on the PR just for this.
This type is useful for two things:
* Doing non-local control flow with ucontext.h functions.
* Inspecting machine state in a signal handler.
The first use case is not one we support; we no longer expose bindings to those
functions in the standard library. They're also deprecated in POSIX and, as a
result, not available in musl.
The second use case is valid, but is very poorly served by the standard library.
As evidenced by my changes to std.debug.cpu_context.signal_context_t, users will
be better served rolling their own ucontext_t and especially mcontext_t types
which fit their specific situation. Further, these types tend to evolve
frequently as architectures evolve, and the standard library has not done a good
job keeping up, or even providing them for all supported targets.
