tests/all/module.rs

use wasmtime::*;

#[test]
fn checks_incompatible_target() -> Result<()> {
    let mut target = target_lexicon::Triple::host();
    target.operating_system = target_lexicon::OperatingSystem::Unknown;
    match Module::new(
        &Engine::new(Config::new().target(&target.to_string())?)?,
        "(module)",
    ) {
        Ok(_) => unreachable!(),
        Err(e) => assert!(
            format!("{e:?}").contains("configuration does not match the host"),
            "bad error: {e:?}"
        ),
    }

    Ok(())
}

#[test]
fn caches_across_engines() {
    let c = Config::new();

    let bytes = Module::new(&Engine::new(&c).unwrap(), "(module)")
        .unwrap()
        .serialize()
        .unwrap();

    unsafe {
        let res = Module::deserialize(&Engine::default(), &bytes);
        assert!(res.is_ok());

        // differ in runtime settings
        let res = Module::deserialize(
            &Engine::new(Config::new().static_memory_maximum_size(0)).unwrap(),
            &bytes,
        );
        assert!(res.is_err());

        // differ in wasm features enabled (which can affect
        // runtime/compilation settings)
        let res = Module::deserialize(
            &Engine::new(Config::new().wasm_threads(false)).unwrap(),
            &bytes,
        );
        assert!(res.is_err());
    }
}

#[test]
#[cfg_attr(miri, ignore)]
fn aot_compiles() -> Result<()> {
    let engine = Engine::default();
    let bytes = engine.precompile_module(
        "(module (func (export \"f\") (param i32) (result i32) local.get 0))".as_bytes(),
    )?;

    let module = unsafe { Module::deserialize(&engine, &bytes)? };

    let mut store = Store::new(&engine, ());
    let instance = Instance::new(&mut store, &module, &[])?;

    let f = instance.get_typed_func::<i32, i32>(&mut store, "f")?;
    assert_eq!(f.call(&mut store, 101)?, 101);

    Ok(())
}

#[test]
#[cfg_attr(miri, ignore)]
fn serialize_deterministic() {
    let engine = Engine::default();

    let assert_deterministic = |wasm: &str| {
        let p1 = engine.precompile_module(wasm.as_bytes()).unwrap();
        let p2 = engine.precompile_module(wasm.as_bytes()).unwrap();
        if p1 != p2 {
            panic!("precompile_module not deterministic for:\n{wasm}");
        }

        let module1 = Module::new(&engine, wasm).unwrap();
        let a1 = module1.serialize().unwrap();
        let a2 = module1.serialize().unwrap();
        if a1 != a2 {
            panic!("Module::serialize not deterministic for:\n{wasm}");
        }

        let module2 = Module::new(&engine, wasm).unwrap();
        let b1 = module2.serialize().unwrap();
        let b2 = module2.serialize().unwrap();
        if b1 != b2 {
            panic!("Module::serialize not deterministic for:\n{wasm}");
        }

        if a1 != b2 {
            panic!("not matching across modules:\n{wasm}");
        }
        if b1 != p2 {
            panic!("not matching across engine/module:\n{wasm}");
        }
    };

    assert_deterministic("(module)");
    assert_deterministic("(module (func))");
    assert_deterministic("(module (func nop))");
    assert_deterministic("(module (func) (func (param i32)))");
    assert_deterministic("(module (func (export \"f\")) (func (export \"y\")))");
    assert_deterministic("(module (func $f) (func $g))");
    assert_deterministic("(module (data \"\") (data \"\"))");
    assert_deterministic("(module (elem func) (elem func))");
}

// This test asserts that the optimization to transform separate data segments
// into an initialization image doesn't unnecessarily create a massive module by
// accident with a very large initialization image in it.
#[test]
fn serialize_not_overly_massive() -> Result<()> {
    let mut config = Config::new();
    config.memory_guaranteed_dense_image_size(1 << 20);
    let engine = Engine::new(&config)?;

    let assert_smaller_than_1mb = |module: &str| -> Result<()> {
        println!("{module}");
        let bytes = Module::new(&engine, module)?.serialize()?;
        assert!(bytes.len() < (1 << 20));
        Ok(())
    };

    // Tons of space between data segments should use sparse initialization,
    // along with various permutations of empty and nonempty segments.
    assert_smaller_than_1mb(
        r#"(module
            (memory 20000)
            (data (i32.const 0) "a")
            (data (i32.const 0x200000) "b")
        )"#,
    )?;
    assert_smaller_than_1mb(
        r#"(module
            (memory 20000)
            (data (i32.const 0) "a")
            (data (i32.const 0x200000) "")
        )"#,
    )?;
    assert_smaller_than_1mb(
        r#"(module
            (memory 20000)
            (data (i32.const 0) "")
            (data (i32.const 0x200000) "b")
        )"#,
    )?;
    assert_smaller_than_1mb(
        r#"(module
            (memory 20000)
            (data (i32.const 0) "")
            (data (i32.const 0x200000) "")
        )"#,
    )?;

    // lone data segment
    assert_smaller_than_1mb(
        r#"(module
            (memory 20000)
            (data (i32.const 0x200000) "b")
        )"#,
    )?;

    Ok(())
}

// This test specifically disables SSE4.1 in Cranelift which force wasm
// instructions like `f32.ceil` to go through libcalls instead of using native
// instructions. Note that SIMD is also disabled here because SIMD otherwise
// requires SSE4.1 to be enabled.
//
// This test then also tests that loading modules through various means, e.g.
// through precompiled artifacts, all works.
#[test]
#[cfg_attr(any(not(target_arch = "x86_64"), miri), ignore)]
fn missing_sse_and_floats_still_works() -> Result<()> {
    let mut config = Config::new();
    config.wasm_simd(false).wasm_relaxed_simd(false);
    unsafe {
        config.cranelift_flag_set("has_sse41", "false");
    }
    let engine = Engine::new(&config)?;
    let module = Module::new(
        &engine,
        r#"
            (module
                (func (export "f32.ceil") (param f32) (result f32)
                    local.get 0
                    f32.ceil)
            )
        "#,
    )?;
    let bytes = module.serialize()?;
    let module2 = unsafe { Module::deserialize(&engine, &bytes)? };
    let tmpdir = tempfile::TempDir::new()?;
    let path = tmpdir.path().join("module.cwasm");
    std::fs::write(&path, &bytes)?;
    let module3 = unsafe { Module::deserialize_file(&engine, &path)? };

    for module in [module, module2, module3] {
        let mut store = Store::new(&engine, ());
        let instance = Instance::new(&mut store, &module, &[])?;
        let ceil = instance.get_typed_func::<f32, f32>(&mut store, "f32.ceil")?;

        for f in [1.0, 2.3, -1.3] {
            assert_eq!(ceil.call(&mut store, f)?, f.ceil());
        }
    }

    Ok(())
}

#[test]
#[cfg_attr(miri, ignore)]
fn large_add_chain_no_stack_overflow() -> Result<()> {
    let mut config = Config::new();
    config.cranelift_opt_level(OptLevel::None);
    let engine = Engine::new(&config)?;
    let mut wat = String::from(
        "
        (module
            (func (result i64)
                (i64.const 1)
        ",
    );
    for _ in 0..20_000 {
        wat.push_str("(i64.add (i64.const 1))\n");
    }

    wat.push_str(")\n)");
    Module::new(&engine, &wat)?;

    Ok(())
}

#[test]
fn compile_a_component() -> Result<()> {
    let engine = Engine::default();
    let err = Module::new(&engine, "(component)").unwrap_err();
    let err = format!("{err:?}");
    assert!(
        err.contains("expected a WebAssembly module but was given a WebAssembly component"),
        "bad error: {err}"
    );
    Ok(())
}

#[test]
fn tail_call_defaults() -> Result<()> {
    let wasm_with_tail_calls = "(module (func $a return_call $a))";

    // on by default
    Module::new(&Engine::default(), wasm_with_tail_calls)?;

    // on by default for cranelift
    Module::new(
        &Engine::new(Config::new().strategy(Strategy::Cranelift))?,
        wasm_with_tail_calls,
    )?;

    if cfg!(target_arch = "x86_64") {
        // off by default for winch
        let err = Module::new(
            &Engine::new(Config::new().strategy(Strategy::Winch))?,
            wasm_with_tail_calls,
        );
        assert!(err.is_err());
    }
    Ok(())
}

#[test]
fn cross_engine_module_exports() -> Result<()> {
    let a_engine = Engine::default();
    let b_engine = Engine::default();

    let a_module = Module::new(&a_engine, "(module)")?;
    let b_module = Module::new(
        &b_engine,
        r#"
            (module
                (func (export "x"))
            )
        "#,
    )?;

    let export = b_module.get_export_index("x").unwrap();

    let mut store = Store::new(&a_engine, ());
    let instance = Instance::new(&mut store, &a_module, &[])?;
    assert!(instance.get_module_export(&mut store, &export).is_none());
    Ok(())
}