stdwasm

A smaller standard library for web assembly apps written in C

• NULL, TRUE, FALSE, SUCCESS, FAILURE
• export attribute for easily exposing a function on web assembly
• assert() with compatability for west testing framework
• malloc, free, realloc
• json_parse, json_stringify
• vector, hashmap, linked list
• immutable string helpers
• webdom.h for accessing DOM,canvas,webgl via web-dom

Why create a new standard library?

stdwasm is a subset of stdlib that is targeted for web assembly. Web assembly has very minimal capabilities — essentially just memory access, limited number types, and whatever you've chosen to import. The C standard library however contains many ideas meant for a variety of architectures and system capabilities that may not reflect web assembly itself, the web, or other places web assembly might run (wasmer, embedded, etc.). Current trends for web assembly in C require bindings (like emscripten) that makes web assembly modules locked to an API of imports it may not even use. Building an app that uses stdwasm and needs environment capabilities (like DOM access or file access) would have you use 3rd party libary that directly reflects the environment your web assembly runs in (such as web-dom for DOM access) hopefully creating less magic about what's going on. This project aims to enable an ecosystem of libraries that run highly optimized web assembly code and are portable the many places web assembly runs.

To give specific examples of what stdwasm will not include:

• fprintf, fopen that work on files
• printf and logging functions

stdwasm will however include:

• malloc, memcpy and other memory management functions
• common defines like NULL

Hello World

#include "stdwasm.h"
#include "webdom.h"

export int main() {      
  console_log("Hello World!");
}

Testing

#include "stdwasm.h"
export int test_addition(){
  assert(4 == 2*2,"2*2 should be 4");
  assert(1 == 1*1,"1*1 should be 1");
  return SUCCESS;
}

Compiling this project

You'll need several LLVM tools before you can compile:

Add to your sources appropriate sources

sudo vim /etc/apt/sources.list

choose the right sources from http://apt.llvm.org/

sudo apt-get update
sudo apt-get install llvm-8
sudo apt-get install wasm-ld-8
sudo apt-get install lld-8
sudo apt-get install clang-8
sudo apt-get install clang-format

Now you should be ready to build

make