Function big_stack_works_ok

tests/all/stack_overflow.rs:124–164

(config: &mut Config)

#[wasmtime_test]
fn big_stack_works_ok(config: &mut Config) -> Result<()> {
    // This test takes 1m+ in ASAN and isn't too useful, so prune it.
    if cfg!(asan) {
        return Ok(());
    }

    const N: usize = 10000;

    // Build a module with a function that uses a very large amount of stack space,
    // modeled here by calling an i64-returning-function many times followed by
    // adding them all into one i64.
    //
    // This should exercise the ability to consume multi-page stacks and
    // only touch a few internals of it at a time.
    let mut s = String::new();
    s.push_str("(module\n");
    s.push_str("(func (export \"\") (result i64)\n");
    s.push_str("i64.const 0\n");
    for _ in 0..N {
        s.push_str("call $get\n");
    }
    for _ in 0..N {
        s.push_str("i64.add\n");
    }
    s.push_str(")\n");
    s.push_str("(func $get (result i64) i64.const 0)\n");
    s.push_str(")\n");

    // Disable cranelift optimizations to ensure that this test doesn't take too
    // long in debug mode due to the large size of its code.
    config.cranelift_opt_level(OptLevel::None);
    config.cranelift_regalloc_algorithm(RegallocAlgorithm::SinglePass);
    let engine = Engine::new(config)?;

    let mut store = Store::new(&engine, ());
    let module = Module::new(store.engine(), &s)?;
    let instance = Instance::new(&mut store, &module, &[])?;
    let func = instance.get_typed_func::<(), i64>(&mut store, "")?;
    assert_eq!(func.call(&mut store, ())?, 0);
    Ok(())
}

#[test]
fn infinite_wasm_stack_does_not_panic() -> Result<()> {