The reason this is required is for two reasons: 1) the libc
targeting `aarch64` macOS is slightly newer than that targeting
`x86_64`, and 2) `OSAtomic.h` uses relative imports rather than
system-wide imports for accompanying headers which clearly is an
oversight on Apple's part. Until such time when `libkern` headers
between `x86_64` and `aarch64` are identical, this will require a
manual intervention to duplicate the relevant headers between the
respective architectures.
See #5854
Some tiny tweaks too:
* Use `wasm-freestanding-musl` instead of `wasm32-freestanding-musl`,
making it pointer-size-agnostic.
* Fix trying to build non-existent wasm musl start files.
See ziglang/fetch-them-macos-headers#2 for more details. The path
forward looks like one of the following:
* Ony provide headers for the oldest supported macOS (currently 10.13
but soon to be bumped to 10.14).
* Provide headers for multiple versions, and select based on the Zig
target OS version range minimum.
* Don't try to provide macOS headers.
If we don't tackle the version problem, we would have to re-introduce
the ability to detect and depend on native system headers if we wanted
to support C/C++ code that used newer OS definitions.
This patch also adds support for `#include <mach/mach_time.h>`.
Also related: #5236
these new files are generated by recursively including:
sysexits.h
mach/mach.h
sys/attr.h
sys/mount.h
crt_externs.h
execinfo.h
all of which are depended on by LLVM libraries.
Clang pretends to be gcc 4.4 and that causes some re-definition errors.
The problem has been reported to the upstream some time ago but nothing
was done about it.
It was using __GNUC__ < 8 to check if _xgetbv intrinsic is available.
Since we always use zig cc with this header, we know we have clang 9,
which does have this intrinsic.
The previous
[instructions](https://github.com/ziglang/zig/wiki/Updating-libc) for
updating musl libc headers had this (repeated for each architecture):
make DESTDIR=build-all/arm install-headers ARCH=arm
However musl's build system does not properly rebuild alltypes.h and
syscall.h from source, instead using whatever is cached from the
previous build. In the case of the previous time that I updated to musl
1.1.23, this happened to be the aarch64 architecture.
As a workaround, one can remove the obj/ directory to force rebuilding
this file. Now the instructions say this (repeated for each architecture):
rm -rf obj/ && make DESTDIR=build-all/arm install-headers ARCH=arm
This commit updates the resulting headers after this workaround is
applied and the process headers tool is run again.
also start prefering NtDll API. so far:
* NtQueryInformationFile
* NtClose
adds a performance workaround for windows unicode conversion. but that
should probably be removed before merging
