If there are zerofill sections, the loader may copy the contents of
the physical space in file directly into memory and attach that to
the zerofill section. This is a performance optimisation in the loader
but requires us, the linker, to properly zero-out any space between
__DATA and __LINKEDIT segments in file. This is of course completely
skipped if there are no zerofill sections present.
This is a temporary workaround to an unclear platform-dependence
behavior we have in libstd for `std.fs.File` abstraction. See
https://github.com/ziglang/zig/issues/12783 for more information.
Previously if a decl failed its capture scope would be deallocated and
set to undefined which would then lead to invalid dereference in
`zirClosureGet`. To avoid this set the capture scope to a special
failed state and fail the current decl with dependency failure if
the failed state is encountered in `zirClosureGet`.
Closes#12433Closes#12530Closes#12593
This relieves register pressure, and reduce generated code size
(since now we can use the same index register for both `mov_scale_src`
and `mov_scale_dst` MIR instructions).
Fix lowering of ModRM + SIB encodings where index register is extended
- previously, we would carelessly ignore the fact generating incorrect
encodings.
As far as I can see, unlike with MachO, we don't have any stubs
helper routines available and need to load a bound pointer into
a register to then call it.
Although the wasm-linker previously already supported
debug information in incremental-mode, this was no longer
working as-is with the addition of supporting object-file-parsed
debug information. This commit implements the Zig-created debug information
structure from scratch which is a lot more robust and also allows
being linked with debug information from other object files.