Stream: general

Topic: WASI-SDK: compile C++ using ref-types feature

mainrs (Mar 06 2025 at 10:00):

My code looks like this:

// api.h
extern uintptr_t host_create_resource(char* dataString);

// WASI module main.c
#include <api.h>

int main() {
  host_create_resource("hello, world!");
  return 0;
}

The compiled WASM file (converted to WAT), does not contain externref function parameters. The return value of host_create_resource is marked as i32.

I can't figure out how to make the final WASM module use the ref-types feature. My runtime is WAMR. I noticed the issue because the host function implementation looks like this:

uintptr_t
host_create_resource_wrapper(wasm_exec_env_t exec_env, char* msg) {
    return 0;
}

static nativeSymbols = {
    REG_NATIVE_FUNC(host_create_resource, "($)r")
}

The linking fails at runtime. iwasm cannot find a function that matches the signature ($)r. And that makes sense. The type of host_create_source is (type (;4;) (func (param i32) (result i32))).

Thank you!

Last updated: Dec 06 2025 at 06:05 UTC