JSTests/wasm/function-tests/exceptions.js

import Builder from '../Builder.js'
import * as assert from '../assert.js'

function makeInstance() {
    const tableDescription = {initial: 1, element: "funcref"};
    const builder = new Builder()
        .Type()
            .Func(["i32", "i32"], "i32")
            .Func(["i32"], "i32")
        .End()
        .Import()
            .Table("imp", "table", tableDescription)
        .End()
        .Function().End()
        .Export()
            .Function("foo")
            .Function("bar")
        .End()
        .Code()
            .Function("foo", 0 /*['i32', 'i32'] => 'i32'*/)
                .GetLocal(1) // parameter to call
                .GetLocal(0) // call index
                .CallIndirect(1, 0) // calling function of type ['i32'] => 'i32'
                .Return()
            .End()
            .Function("bar", 1 /*['i32'] => 'i32'*/)
                .GetLocal(0)
                .I32Const(42)
                .I32Add()
                .Return()
            .End()
        .End();


    const bin = builder.WebAssembly().get();
    const module = new WebAssembly.Module(bin);
    const table = new WebAssembly.Table(tableDescription);
    return {instance: new WebAssembly.Instance(module, {imp: {table}}), table};
}

{
    const {instance, table} = makeInstance();
    const foo = instance.exports.foo;
    const bar = instance.exports.bar;
    assert.eq(table.get(0), null);

    for (let i = 0; i < 1000; i++) {
        assert.throws(() => foo(0, i), WebAssembly.RuntimeError, "call_indirect to a null table entry");
    }

    table.set(0, foo);
    assert.eq(table.get(0), foo);

    for (let i = 0; i < 1000; i++) {
        assert.throws(() => foo(1 + i, i), WebAssembly.RuntimeError, "Out of bounds call_indirect");
    }

    for (let i = 0; i < 1000; i++) {
        assert.throws(() => foo(0, i), WebAssembly.RuntimeError, "call_indirect to a signature that does not match");
    }

    table.set(0, bar);
    assert.eq(table.get(0), bar);
    for (let i = 0; i < 25; i++) {
        assert.eq(foo(0, i), i + 42);
    }
}