9efc2f4283
* Lazy-initialize the environment variables. This is the first in a series of PRs to make it easier to use WASI libc in Wasm modules that don't have a `main` function. By initializing the environment on demand, we avoid depending on having `__wasm_call_ctors` run. This uses weak symbols strategically to ensure that if `environ` is used, it is initialized eagerly, but if only `getenv` and friends are used, the environment is initialized lazily. Eventually, I expect we'll have a convention for wasm modules without main functions which will allow the `__wasm_call_ctors` function to be called automatically, but this helps in simple cases for now. Fixes #180. * Add comments explaining the libc-environ-compat.h header usage. |
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| .. | ||
| cloudlibc | ||
| crt | ||
| headers | ||
| libpreopen | ||
| mman | ||
| sources | ||
| README.md | ||
"WASI" the WebAssembly System Interface.
WASI libc is conceptually the lower half of a traditional libc implementation. It provides C interfaces to the low-level WASI syscalls.
This is largely based on CloudABI, cloudlibc, and libpreopen, however we use just the low-level syscall wrappers rather than all of cloudlibc and libpreopen, and we have several customizations for use in a WebAssembly sysroot.
The upstream repositories and versions used here are:
cloudlibc - https://github.com/NuxiNL/cloudlibc 8835639f27fc42d32096d59d294a0bbb857dc368 libpreopen - https://github.com/musec/libpreopen b29e9287cc75a7db7291ce3eb468a3d2bad8ceb1
Whole files which are unused are omitted. Changes to upstream code are wrapped
in preprocessor directives controlled by the macro __wasilibc_unmodified_upstream,
except that CloudABI names have also been renamed to WASI names without annotations.
WASI libc currently depends on the basics and dlmalloc components of reference-sysroot.