`std.zig.system.darwin.getSdk` now pulls only the SDK path
so we execute a child process only once and not twice as it was
until now since we parse the SDK version directly from the pulled path.
This is actually how `ld64` does it too.
There are a couple concepts here worth understanding:
Key.UnionType - This type is available *before* resolving the union's
fields. The enum tag type, number of fields, and field names, field
types, and field alignments are not available with this.
InternPool.UnionType - This one can be obtained from the above type with
`InternPool.loadUnionType` which asserts that the union's enum tag type
has been resolved. This one has all the information available.
Additionally:
* ZIR: Turn an unused bit into `any_aligned_fields` flag to help
semantic analysis know whether a union has explicit alignment on any
fields (usually not).
* Sema: delete `resolveTypeRequiresComptime` which had the same type
signature and near-duplicate logic to `typeRequiresComptime`.
- Make opaque types not report comptime-only (this was inconsistent
between the two implementations of this function).
* Implement accepted proposal #12556 which is a breaking change.
The key changes in this commit are:
```diff
- names: []const NullTerminatedString,
+ names: NullTerminatedString.Slice,
- values: []const Index,
+ values: Index.Slice,
```
Which eliminates the slices from `InternPool.Key.EnumType` and replaces
them with structs that contain `start` and `len` indexes. This makes the
lifetime of `EnumType` change from expiring with updates to InternPool,
to expiring when the InternPool is garbage-collected, which is currently
never.
This is gearing up for a larger change I started working on locally
which moves union types into InternPool.
As a bonus, I fixed some unnecessary instances of `@as`.
This is in particular very important to the Zig language which
allows exporting the same symbol under different names. For instance,
it is possible to have a case such that:
```
...
4258 T _foo
4258 T _bar
...
```
In this case we need to keep track of both symbol names when resolving
FDEs and unwind records.
Regressed in 2006add8496c47804ee3b6c562f420871cb4ea0a.
References to native_darwin_sdk are no longer kept in the frontend.
Instead the darwin SDK is detected as part of NativePaths and as part of
LibCInstallation.
This can be null in two cases right now:
1. Windows DLLs that zig ships such as advapi32.
2. extern "foo" fn declarations where we find out about libraries too late
TODO: make this non-optional and resolve those two cases somehow.
Putting them in both causes collisions because the same lib ends up
being linked in twice.
Putting them in positionals instead of libs makes their properties about
needed and weak being ignored.
search_strategy is no longer passed to Compilation at all; instead it is
used in the CLI code only.
When using Zig CLI mode, `-l` no longer has the ability to link
statically; use positional arguments for this.
The CLI has a small abstraction around library resolution handling which
is used to remove some code duplication regarding static libraries, as
well as handle the difference between zig cc CLI mode and zig CLI mode.
Thanks to this, system libraries are now included in the cache hash, and
thus changes to them will correctly cause cache misses.
In the future, lib_dirs should no longer be passed to Compilation at
all, because it is a frontend-only concept.
Previously, -search_paths_first and -search_dylibs_first were
Darwin-only arguments; they now work the same for all targets. Same
thing with --sysroot.
Improved the error reporting for failure to find a system library. An
example error now looks like this:
```
$ zig build-exe test.zig -lfoo -L. -L/a -target x86_64-macos --sysroot /home/andy/local
error: unable to find Dynamic system library 'foo' using strategy 'no_fallback'. search paths:
./libfoo.tbd
./libfoo.dylib
./libfoo.so
/home/andy/local/a/libfoo.tbd
/home/andy/local/a/libfoo.dylib
/home/andy/local/a/libfoo.so
/a/libfoo.tbd
/a/libfoo.dylib
/a/libfoo.so
```
closes#14963
This solves the nuance case of compiling hand-crafted assembly files
which do not feature `MH_SUBSECTIONS_VIA_SYMBOLS` flag resulting in
input `Atom`s encompassing multiple symbols each with unique unwind
information.
