This commit reworks how anonymous struct literals and tuples work.
Previously, an untyped anonymous struct literal
(e.g. `const x = .{ .a = 123 }`) was given an "anonymous struct type",
which is a special kind of struct which coerces using structural
equivalence. This mechanism was a holdover from before we used
RLS / result types as the primary mechanism of type inference. This
commit changes the language so that the type assigned here is a "normal"
struct type. It uses a form of equivalence based on the AST node and the
type's structure, much like a reified (`@Type`) type.
Additionally, tuples have been simplified. The distinction between
"simple" and "complex" tuple types is eliminated. All tuples, even those
explicitly declared using `struct { ... }` syntax, use structural
equivalence, and do not undergo staged type resolution. Tuples are very
restricted: they cannot have non-`auto` layouts, cannot have aligned
fields, and cannot have default values with the exception of `comptime`
fields. Tuples currently do not have optimized layout, but this can be
changed in the future.
This change simplifies the language, and fixes some problematic
coercions through pointers which led to unintuitive behavior.
Resolves: #16865
Primarily, this moves linker input parsing from flush() into the linker
task queue, which is executed simultaneously with the frontend.
I also made it avoid redundantly opening the same archive file N times
for each object file inside. Furthermore, hard code fixed buffer stream
rather than using a generic stream type.
Finally, I fixed the error handling of the Wasm.Archive.parse function.
Please pay attention to this pattern of returning a struct rather than
accepting a mutable struct as an argument. This ensures function-level
atomicity and makes resource management straightforward.
Deletes the file and path fields from Archive and Object.
Removed a well-meaning but ultimately misguided suggestion about how to
think about ZigObject since thinking about it that way has led to
problematic anti-DOD patterns.
Removes the `files` field from the Wasm linker, storing the ZigObject
as its own field instead using a tagged union.
This removes a layer of indirection when accessing the ZigObject, and
untangles logic so that we can introduce a "pre-link" phase that
prepares the linker state to handle only incremental updates to the
ZigObject and then minimize logic inside flush().
Furthermore, don't make array elements store their own indexes, that's
always a waste.
Flattens some of the file system hierarchy and unifies variable names
for easier refactoring.
Introduces type safety for optional object indexes.
* AIX has its own bespoke format.
* Handle all Apple platforms.
* FreeBSD and OpenBSD both use the GNU format in LLVM.
* Windows has since been switched to the COFF format by default in LLVM.
LLVM recently introduced new Triple::ArchType members in 19.1.3 which broke our
static assertions in zig_llvm.cpp. When implementing a fix for that, I realized
that we don't even need a lot of the stuff we have in zig_llvm.(cpp,h) anymore.
This commit trims the interface down considerably.
According to a comment in mold, this is the expected (and desired)
condition by the linkers, except for some architectures (RISCV and
Loongarch) where this condition does not have to upheld.
If you follow the changes in this patch and in particular doc comments
I have linked the comment/code in mold that explains and implements
this.
I have also modified `testEhFrameRelocatable` test to now test both
cases such that `zig ld -r a.o b.o -o c.o` and `zig ld -r b.o a.o -o
d.o`. In both cases, `c.o` and `d.o` should produce valid object
files which was not the case before this patch.
This caused a missing reference for u16 to not be emitted. Triggered
after removing something from start.zig which transitively added u16
to the module.
Also, start using labeled switch statements when dispatching
maybe-runtime instructions like condbr to comptime-only variants like
condbr_inline.
This can't be merged until we get a zig1.wasm update due to #21385.
Resolves: #21405
Under some architecture/operating system combinations it is forbidden
to return a pointer from a merge, as these pointers must point to a
location at compile time. This adds a check for those cases when
returning a pointer from a block merge.
using `.C` in Sema is incorrect since it will be resolved under the target that Zig was compiled with, not the target build configuration. This is easily solved by just calling `cCallingConvention` on the target to resolve it.
these tasks have some shared data dependencies so they cannot be done
simultaneously. Future work should untangle these data dependencies so
that more can be done in parallel.
for now this commit ensures correctness by making linker input parsing
and codegen tasks part of the same queue.
Unfortunately it's not a complete solution, so a follow-up commit will
need to do something more drastic like not do the linker task queue at
the same time as codegen task queue.
From that point, it is possible to do more work at the same time but
that should be a separate branch. This one has gotten big enough.
If the "is darwin" check is moved below the libc_installation check
below, error.LibCInstallationMissingCrtDir is returned from
lci.resolveCrtPaths().
This should be revisited because it makes sense to check
libc_installation first even on darwin.
Anyway for now this more closely matches logic from master branch.
By making it a field of link.Elf, it is now accessible without a data
dependency on `files`, fixing a race condition with the codegen thread
and linker thread.
