wasmtest00

test compiling c to wasm without c-lib or emscripten using clang-7 and ./0m shell script

add.wasm adds two int numbers and prints result on console log

lenstr.wasm print length of string on console log

because lenstr.wasm uses wasm memory add linker flag -Wl,--import-memory to clang

It needs lld package installed and python webserver but not thttpd

python -m SimpleHTTPDServer

Then browse to localhost:8000

Using firefox developers console to see output from console.log()

This is how wasm in c allocates memory in PAGESIZE sizes at once

uintptr_t old = __builtin_wasm_memory_grow(0, (uintptr_t)increment / PAGESIZE);

and this is wasm pagesize definition:

The page size in WebAssembly is fixed at 64 KiB. If this ever changes, it's expected that applications will need to opt in, so we can change this.

#define PAGESIZE (0x10000)

end.