posix: add package

core/sys/posix/README.md

@@ -0,0 +1,57 @@
+# POSIX
+
+defines bindings for most posix APIs.
+
+If a header is added, all of it must be implemented.
+
+Each platform must define the exact same symbols, different values are allowed, even structs with different non-standard fields.
+
+APIs part of extensions may be left out completely if one target doesn't implement it.
+
+APIs with a direct replacement in `core` might not be implemented.
+
+Macros are emulated with force inlined functions.
+
+Struct fields defined by the posix standard (and thus portable) are documented with `[PSX]`.
+
+
+ADD A TEST FOR SIGINFO, one thread signalling and retrieving the signal out of siginfo or something.
+ADD A TEST FOR wait.h
+ADD A TEST FOR pthread.
+ADDD A test for stat.h.
+ADD A TEST FOR setjmp.h.
+HAIKU.
+
+Unimplemented POSIX headers:
+
+- aio.h
+- complex.h | See `core:c/libc` and our own complex types
+- cpio.h
+- ctype.h | See `core:c/libc` for most of it
+- ndbm.h | Never seen or heard of it
+- fenv.h
+- float.h
+- fmtmsg.h
+- ftw.h
+- semaphore.h | See `core:sync`
+- inttypes.h | See `core:c`
+- iso646.h | Impossible
+- math.h | See `core:c/libc`
+- mqueue.h | Targets don't seem to have implemented it
+- regex.h | See `core:regex`
+- search.h | Not useful in Odin
+- spawn.h | Use `fork`, `execve`, etc.
+- stdarg.h | See `core:c/libc`
+- stdint.h | See `core:c`
+- stropts.h
+- syslog.h
+- pthread.h | Only the actual threads API is bound, see `core:sync` for synchronization primitives
+- string.h | Most of this is not useful in Odin, only a select few symbols are bound
+- tar.h
+- tgmath.h
+- trace.h
+- wchar.h
+- wctype.h
+
+TODO:
+- time.h | Docs