Compile C/C++ to Wasm WASI

Now that you have Wasienv installed, let's get our hands dirty!
Wasienv comes with C/C++ support preinstalled, so you just need to run one command to get things running 🙂
Compiling C files with `wasic`
If you want to compile a simple C example, you can just create the following:
example.c
fizzbuzz.c
#include <stdio.h>
​
int main(int argc, char **argv)
{
    if (argc < 2) {
        printf("Hello, WASI!\n");
    } else {
        printf("Hello, %s!\n", argv[1]);
    }
}
// CPP program to print Fizz Buzz 
#include <stdio.h> 
​
int main(void) 
{ 
    int i; 
    for (i=1; i<=100; i++) 
    { 
        // number divisible by 3 and 5 will 
        // always be divisible by 15, print  
        // 'FizzBuzz' in place of the number 
        if (i%15 == 0)         
            printf ("FizzBuzz\t");     
​
        // number divisible by 3? print 'Fizz' 
        // in place of the number 
        else if ((i%3) == 0)     
            printf("Fizz\t");                  
​
        // number divisible by 5, print 'Buzz'   
        // in place of the number 
        else if ((i%5) == 0)                        
            printf("Buzz\t");                  
​
        else // print the number             
            printf("%d\t", i);                  
​
    } 
​
    return 0; 
}
Now that you have this file created, you can execute wasicc
wasicc example.c -o example.wasm
Et voilá... you will have a new file example.wasm ready to be executed with your favorite WebAssembly runtime!
$ wasmer example.wasm
Hello, WASI!
Did you know?
You can also execute the example.wasm file in your browser or in Node.js using @wasmer/wasi. Check out the examples on how to do it!
​WASI in the browser​
​WASI in Node.js​
Compiling C++ files with `wasic++`
Wasienv also allows you to compile C++ files to Wasm WASI, just run it with wasic++
Using Configure and Make
In some projects, there might be already ./configure files that will configure the system (creating a Makefile normally) to compile a certain project.
If you want to use Wasienv there, you just need to wrap your ./configure call with wasiconfigure!
wasiconfigure ./configure
Wasienv also has a wrapper for Makefiles
wasimake make
Here's an example of a C Project that was compiled to Wasm WASI with wasienv:
​https://github.com/wapm-packages/jq/blob/master/build.sh​
Using CMake
Similarly to configure and make, we also have another command that will automatically compile all your projects made with CMake
wasicmake cmake .
make
Here's an example project: quickjs that was compiled to WebAssembly WASI thanks to Wasienv!
And the build.sh file they used for generating the wasm file:
#!/bin/bash
​
# Install wasienv
curl https://raw.githubusercontent.com/wasienv/wasienv/master/install.sh | sh
​
mkdir -p build
cd build
wasimake cmake ..
cd ..
make -C build

Getting Started

Compile Swift to Wasm WASI

Last modified 1yr ago