While investigating hexops/mach#8 with @slimsag,
we found that zld is forming invalid file paths (absolute paths concatenated together),
which hits the unreachable `OBJECT_NAME_INVALID` case in `openDirAccessMaskW`:
0c091feb5a/lib/std/fs.zig (L1522)
This is caused by appending `dir` (which is guaranteed to be absolute) to `root`,
an obviously incorrect operation:
0c091feb5a/src/link/MachO.zig (L494-L499)Fixeshexops/mach#8
Co-authored-by: Stephen Gutekanst <stephen@hexops.com>
Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
Signed-off-by: Andrew Gutekanst <andrew.gutekanst@gmail.com>
The language reference's HTML has been updated to be more semantically correct.
This also helps to improve the document's accessibility concerns.
* Document structure has single h1, other header sections start at h2, nav sections w/ aria labels, main section
* Zig's homepage is linked, Zig Standard Library section link to it
* Tables have caption and scoping rows and columns
* Code blocks are figures with figure captions citing source files
* Change line height 1.5 to include table of contents as well
* Luminosity contrast ratios have been adjusted to 7:1
* Dark mode colors adjusted to reduce eye strain
* Links have default browser underline with hover and focus effects
* Asides, definition lists, keyboard inputs, program outputs are represented semantically
Tools used to check:
WAVE plugin https://wave.webaim.org/
Firefox Accessibility Developer Tool
Lighthouse Accessibility Tool
- On Intel Macs, the path is /usr/local/opt/llvm@12
- On Silicon Macs, the path is /opt/homebrew/opt/llvm@12
This makes specifying CMAKE_PREFIX_PATH optional for Homebrew LLVM.
This is particularly relevant for x86_64 and C++ when relocating
StaticInit sections containing static initializers machine code.
Then, in case of SIGNED_X relocations, it is necessary to have the
full image of the VM address layout of the sections in the object
file as this is how the addend needs to be adjusted for non-extern
relocations.
OpenBSD doesn't implement EVFILT_USER filter for kqueue(2), so we couldn't use that for event loop.
instead, use a EVFILT_TIMER filter with EV_ONESHOT (trigger only once) and delay 0sec (which trigger immediatly).
it fits the usage of EVFILT_USER which is only used to "wakeup" the kevent(2) call from userland.
Also, calculate non-extern, section offset based addends for SIGNED
and UNSIGNED relocations on x86_64 upfront as an offset wrt to the
target symbol representing position of the section/atom within the
final artifact.
Otherwise, Apple's tooling goes mental and reports that the executable
is malformed/fails strict validation. We absolutely have to get it
right to support tools such `codesign` which are required to
successfully launch an app on an iOS device for instance. When Zig
matures enough so that we can ditch any Apple tooling and still be
able to successfully codesign for iOS and other, we can revisit this
area. Until then however, we are stuck in having to rewrite the LINKEDIT
segment at every update run of the self-hosted.
FYI, the strict layout for the MachO binary apparently is (please,
read this with a pinch of salt as this is inferred by me):
* __TEXT segment
* __DATA_CONST segment
* __DATA segment
* __LINKEDIT segment
* dyld info (rebase, bind, weak bind, lazy bind, export)
* symbol table
* dynamic symbol table
* string table
* code signature (if expected)
