The code tried to be too smart and skipped the equality (returning true)
if the payload type was zero-sized.
This optimization is completely wrong when the union payload is a
metatype!
Fixes#7047
It is now possible to force linking with system linker `ld` instead
of the LLVM `lld` linker when building natively on the target. This
can be done at each stage by specifying `--system-linker-hack` flag,
and can be useful on platforms where `lld` fails to operate properly
such as macOS 11 Big Sur on ARM64 where every binary/dylib is expected
to be codesigned.
Some example invocations for each stage of compilation of Zig
toolchain:
```
cmake .. -DCMAKE_PREFIX_PATH=/path/to/llvm -DSYSTEM_LINKER_HACK=1
```
```
build/zig build test --system-linker-hack
```
```
build/zig build --prefix $(pwd)/stage2 -Denable-llvm
--system-linker-hack
```
```
build/zig build-exe hello.zig --system-linker-hack
```
On Darwin, according to the man pages for setrlimit(), when adjusting
max number of open fds, the reported hard max by getrlimit() is only
theoretical, while the actual maximum, set in the kernel, is hardcoded
in the header file. Therefore, the reported max has to be adjusted
as `min(OPEN_MAX, lim.max)`.
Signed-off-by: Jakub Konka <kubkon@jakubkonka.com>
This commit fixes linking issue on macOS 11 BigSur by appending
a prefix path to all lib and framework search paths known as
`-syslibroot`.
The reason this is needed is that in macOS 11, the system libraries
and frameworks are no longer readily available in the filesystem.
Instead, the new macOS ships with a built-in dynamic linker cache
of all system-provided libraries, and hence, when linking with either
`lld.ld64` or `ld64`, it is required to pass in `-syslibroot [dir]`.
The latter can usually be obtained by invoking `xcrun --show-sdk-path`.
With this commit, Zig will do this automatically when compiling natively
on macOS. However, it also provides a flag `-syslibroot` which can be
used to overwrite the automtically populated value.
To summarise, with this change, the user of Zig is not required to
generate and append their own syslibroot path. Standard invocations
such as `zig build-exe hello.zig` or `zig build` for projects will
work out of the box. The only missing bit is `zig cc` and `zig c++`
since the addition of the `-syslibroot` option would be a mismatch
between the values provided by `clang` itself and Zig's wrapper.
