Shadow-cljs WASM example

Minimal project to demonstrate the usage of a WASM module in Shadow-cljs.

Environment setup

npm install

Development build

./build.sh

the default website is at http://localhost:8844

WASM build

The C source file is at src/c/add2.c; it contains just one function:

int add2(int a, int b) {
  return a + b;
}

Note: for simplicity, the wasm file (and its loader js code) are already committed in the repository.

To compile the C code to wasm (for example if you want to test the setup with a more complex C program) you will first of all need a working emsdk environment; Once you do, use the following command line to compile your C file(s):

EMCC_ONLY_FORCED_STDLIBS=1 emcc -O3 -Os -s EXTRA_EXPORTED_RUNTIME_METHODS="['cwrap']" -s INVOKE_RUN=0 -s EXPORT_ALL=1 -s MODULARIZE=1 -s FILESYSTEM=0 -s WASM=1 -s LINKABLE=1 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -o libadd.js add2.c

This will generate two files: libadd.js and libadd.wasm. libadd.wasm goes into resources/public/sasets/app/js while libadd.js goes into resources/wasm.