Boundary symbols have a special name prefix:
* section$start$segname$sectname
* section$stop$segname$sectname
* segment$start$segname
* segment$stop$segname
and will resolve to either start or end of the respective
section/segment if found.
If not found, we return an error stating we couldn't find the
requested section/segment rather than silently failing and resolving
the address to 0 which seems to be the case with Apple's ld64.
* atom names - are stored locally and pulled from defining object's
strtab
* local symbols - same
* global symbols - in principle, we could store them locally, but
for better debugging experience - when things go wrong - we
store the offsets in a global strtab used by the symbol resolver
Use inline to vastly simplify the exposed API. This allows a
comptime-known endian parameter to be propogated, making extra functions
for a specific endianness completely unnecessary.
The main motivating change here is to prevent the creation of a fake
Decl object by the frontend in order to `@export()` a value.
Instead, `link.updateDeclExports` is renamed to `link.updateExports` and
accepts a tagged union which can be either a Decl.Index or a
InternPool.Index.
Implement the stub for Elf.
I believe that separating the concerns, namely, having an interface
function that is responsible for signalling the linker to lower
the anon decl only, and a separate function to obtain the decl's
vaddr is preferable since it allows us to handle codegen errors
in a simpler way.
SDK version detection:
- read SDKSettings.json before inferral from SDK path
- vendored libc: add SDKSettings.json for SDK version info
resolveLibSystem:
- adjust search order to { search_dirs, { sysroot or vendored }}
- previous search order was { sysroot, search_dirs, vendored }
- update include dirs to use combined dir
- use one libSystem.tbd (drop use of libSystem.VERSION.tbd)
- update canBuildLibC to check for minimum os version only
Structs were previously using `SegmentedList` to be given indexes, but
were not actually backed by the InternPool arrays.
After this, the only remaining uses of `SegmentedList` in the compiler
are `Module.Decl` and `Module.Namespace`. Once those last two are
migrated to become backed by InternPool arrays as well, we can introduce
state serialization via writing these arrays to disk all at once.
Unfortunately there are a lot of source code locations that touch the
struct type API, so this commit is still work-in-progress. Once I get it
compiling and passing the test suite, I can provide some interesting
data points such as how it affected the InternPool memory size and
performance comparison against master branch.
I also couldn't resist migrating over a bunch of alignment API over to
use the log2 Alignment type rather than a mismash of u32 and u64 byte
units with 0 meaning something implicitly different and special at every
location. Turns out you can do all the math you need directly on the
log2 representation of alignments.
Eventually, we will validate DWARF info upfront and report errors
to the user but this will require a rewrite of several parts of
the linker so leaving as a TODO for the near future.
