maiac

library1.2.4jsnpmunverified

MaiaC (WebC) is a C-to-WebAssembly compiler written in JavaScript, targeting a C89 subset. Version 1.2.4 (as of March 2025) is released via npm, with development on GitHub. It parses C source using EBNF-generated parsers, lowers to WAT, emits WAT via templates, and validates/assembles via the MaiaWASM submodule. Supports Node.js >=18 and browser execution. Differentiators: pure JavaScript implementation (no native dependencies), built-in runtime bridges for host environment (e.g., console, Math), and distribution packaging for browser + Node workflows. Release cadence appears irregular; check GitHub for latest.

devops web-framework

npm install maiac

github ↗package ↗

INSTALL

IMPORT

SIG · MAIAC

maiac

devopsjavascriptv1.2.4

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

webc (default)

✓ import webc from 'maiac'

✗ const webc = require('maiac')

ESM-only; no CommonJS export. Use import syntax.

createDist

✓ import { createDist } from 'maiac'

✗ import createDist from 'maiac'

Named export, not default.

hostEnvBuilder

✓ import { hostEnvBuilder } from 'maiac'

✗ import HostEnvBuilder from 'maiac'

Named export, lowercase; not a class.

Compile a C89 source string to WebAssembly using MaiaC with WAT output. Demonstrates ESM import and basic usage.

import webc from 'maiac'; import { readFileSync, writeFileSync } from 'fs'; const cSource = `int main() { return 42; }`; const outDir = './out'; const name = 'test'; const result = await webc({ source: cSource, outDir, name, wat: true, run: false }); console.log('Output files:', result.files); // Expected: out/test.wasm, out/test.js (if wrappers generated), out/test.wat // Or compile from file: const sourceFile = './test.c'; const fileResult = await webc({ file: sourceFile, outDir, name: 'test', wat: true }); console.log('Compiled .wasm to:', fileResult.files[0]);

Debug

Known issues

gotchaMaiaC only supports a C89 subset; C99 or later features (e.g., // comments, mixed declarations) will cause parse errors.

fix

Write C89-compliant code: use /* */ comments, declare variables at block start.

affects: >=1.0.0

breakingIn v1.2.0, the default export changed from a class to a function. Using `new webc()` will throw.

fix

Call webc(options) directly without new.

affects: >=1.2.0

deprecatedcreate-dist.js CLI wrapper is deprecated; use tools/webc.js --dist instead.

fix

Run node tools/webc.js compiler/examples/test.c --dist instead of node tools/create-dist.js ...

affects: >=1.2.0

gotchaC source must not use standard library includes like <stdio.h> unless you provide the stubs; external functions must be declared as extern __host__* functions.

fix

Declare I/O via extern __console__log(char* msg) and similar host bridges.

affects: >=1.0.0

gotchaThe --resolve-system-includes flag is experimental and may expand includes incorrectly for nested paths.

fix

Avoid using --resolve-system-includes for production; manually inline includes.

affects: >=1.2.0

Errors

Common errors & fixes

Error: Cannot find module 'maiac'

Running code in Node without installing the package or running from the wrong directory.

fix

Run `npm install maiac` and ensure your script imports from 'maiac' not a relative path.

TypeError: webc is not a constructor

Using `new webc()` after v1.2.0 when webc is now a plain function.

fix

Call `webc(options)` directly without the `new` keyword.

Expected C89 declaration before statement

C code uses C99+ features like mixed declarations and code.

fix

Move variable declarations to the beginning of blocks.

Upgrade

Version history

1.2.4latest on npm

Audit

Dependencies

maiawasmrequiredWAT assembly and validation pipeline (submodule)

maiaccoptionalGrammar-to-parser generation (submodule)

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/souzamonteiro/maiac ↗

packagehttps://www.npmjs.com/package/maiac ↗