Need help with wasi-libc?
Click the “chat” button below for chat support from the developer who created it, or find similar developers for support.

About the developer

WebAssembly
302 Stars 53 Forks Other 189 Commits 28 Opened issues

Description

WASI libc implementation for WebAssembly

Services available

!
?

Need anything else?

Contributors list

WASI Libc

WASI Libc is a libc for WebAssembly programs built on top of WASI system calls. It provides a wide array of POSIX-compatible C APIs, including support for standard I/O, file I/O, filesystem manipulation, memory management, time, string, environment variables, program startup, and many other APIs.

WASI Libc is sufficiently stable and usable for many purposes, as most of the POSIX-compatible APIs are stable, though it is continuing to evolve to better align with wasm and WASI.

Usage

The easiest way to get started with this is to use wasi-sdk, which includes a build of WASI Libc in its sysroot.

Building from source

To build a WASI sysroot from source, obtain a WebAssembly-supporting C compiler (currently this is only clang 8+, though we'd like to support other compilers as well), and then run:

make WASM_CC=/path/to/clang/with/wasm/support \
     WASM_AR=/path/to/llvm-ar \
     WASM_NM=/path/to/llvm-nm

This makes a directory called "sysroot", by default. See the top of the Makefile for customization options.

To use the sysroot, use the

--sysroot=
option:
/path/to/wasm/supporting/c/compiler --sysroot=/path/to/the/newly/built/sysroot ...

to run the compiler using the newly built sysroot.

Note that Clang packages typically don't include cross-compiled builds of compiler-rt, libcxx, or libcxxabi, for

libclang_rt.builtins-wasm32.a
, libc++.a, or libc++abi.a, respectively, so they may not be usable without extra setup. This is one of the things wasi-sdk simplifies, as it includes cross-compiled builds of compiler-rt, libc++.a, and libc++abi.a.

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.