# WASI libc "top half". 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)