The WASI libc "top half" is conceptually the upper half of a traditional libc implementation, consisting of C standard library and other relatively higher-level functionality.
Code in the musl directory is based on musl revision 040c1d16b468c50c04fc94edff521f1637708328, which is v1.2.0, from git://git.musl-libc.org/musl.
Whole files which are unused are omitted. Changes to upstream code are wrapped
in preprocessor directives controlled by the macro __wasilibc_unmodified_upstream.
Some major known missing areas include:
- threads
- aio
- setjmp
- signals
- ipc
- termios
- nss
- timezones
- non-builtin locales
- TIOCGWINSZ (because cloudabi lacks it; affects isatty, line buffering for stdout)
- O_CLOEXEC, O_NOCTTY (because cloudabi lacks them)