use crate::sys::exports::{ExportError, Exportable};
use crate::sys::externals::Extern;
use crate::sys::store::Store;
use crate::sys::types::{Val, ValFuncRef};
use crate::sys::FunctionType;
use crate::sys::NativeFunc;
use crate::sys::RuntimeError;
use crate::sys::WasmerEnv;
pub use inner::{FromToNativeWasmType, HostFunction, WasmTypeList, WithEnv, WithoutEnv};
use std::cmp::max;
use std::ffi::c_void;
use std::fmt;
use std::sync::Arc;
use wasmer_vm::{
raise_user_trap, resume_panic, wasmer_call_trampoline, Export, ExportFunction,
ExportFunctionMetadata, ImportInitializerFuncPtr, VMCallerCheckedAnyfunc,
VMDynamicFunctionContext, VMFuncRef, VMFunction, VMFunctionBody, VMFunctionEnvironment,
VMFunctionKind, VMTrampoline,
};
/// A WebAssembly `function` instance.
///
/// A function instance is the runtime representation of a function.
/// It effectively is a closure of the original function (defined in either
/// the host or the WebAssembly module) over the runtime `Instance` of its
/// originating `Module`.
///
/// The module instance is used to resolve references to other definitions
/// during execution of the function.
///
/// Spec: <https://webassembly.github.io/spec/core/exec/runtime.html#function-instances>
///
/// # Panics
/// - Closures (functions with captured environments) are not currently supported
/// with native functions. Attempting to create a native `Function` with one will
/// result in a panic.
/// [Closures as host functions tracking issue](https://github.com/wasmerio/wasmer/issues/1840)
#[derive(PartialEq)]
pub struct Function {
pub(crate) store: Store,
pub(crate) exported: ExportFunction,
}
impl wasmer_types::WasmValueType for Function {
/// Write the value.
unsafe fn write_value_to(&self, p: *mut i128) {
let func_ref =
Val::into_vm_funcref(&Val::FuncRef(Some(self.clone())), &self.store).unwrap();
std::ptr::write(p as *mut VMFuncRef, func_ref);
}
/// Read the value.
// TODO(reftypes): this entire function should be cleaned up, `dyn Any` should
// ideally be removed
unsafe fn read_value_from(store: &dyn std::any::Any, p: *const i128) -> Self {
let func_ref = std::ptr::read(p as *const VMFuncRef);
let store = store.downcast_ref::<Store>().expect("Store expected in `Function::read_value_from`. If you see this error message it likely means you're using a function ref in a place we don't yet support it -- sorry about the inconvenience.");
match Val::from_vm_funcref(func_ref, store) {
Val::FuncRef(Some(fr)) => fr,
// these bottom two cases indicate bugs in `wasmer-types` or elsewhere.
// They should never be triggered, so we just panic.
Val::FuncRef(None) => panic!("Null funcref found in `Function::read_value_from`!"),
other => panic!("Invalid value in `Function::read_value_from`: {:?}", other),
}
}
}
fn build_export_function_metadata<Env>(
env: Env,
import_init_function_ptr: for<'a> fn(
&'a mut Env,
&'a crate::Instance,
) -> Result<(), crate::HostEnvInitError>,
) -> (*mut c_void, ExportFunctionMetadata)
where
Env: Clone + Sized + 'static + Send + Sync,
{
let import_init_function_ptr = Some(unsafe {
std::mem::transmute::<_, ImportInitializerFuncPtr>(import_init_function_ptr)
});
let host_env_clone_fn = |ptr: *mut c_void| -> *mut c_void {
let env_ref: &Env = unsafe {
ptr.cast::<Env>()
.as_ref()
.expect("`ptr` to the environment is null when cloning it")
};
Box::into_raw(Box::new(env_ref.clone())) as _
};
let host_env_drop_fn = |ptr: *mut c_void| {
unsafe { Box::from_raw(ptr.cast::<Env>()) };
};
let env = Box::into_raw(Box::new(env)) as _;
// # Safety
// - All these functions work on all threads
// - The host env is `Send`.
let metadata = unsafe {
ExportFunctionMetadata::new(
env,
import_init_function_ptr,
host_env_clone_fn,
host_env_drop_fn,
)
};
(env, metadata)
}
impl WasmerEnv for WithoutEnv {}
impl Function {
/// Creates a new host `Function` (dynamic) with the provided signature.
///
/// If you know the signature of the host function at compile time,
/// consider using [`Function::new_native`] for less runtime overhead.
///
/// # Examples
///
/// ```
/// # use wasmer::{Function, FunctionType, Type, Store, Value};
/// # let store = Store::default();
/// #
/// let signature = FunctionType::new(vec![Type::I32, Type::I32], vec![Type::I32]);
///
/// let f = Function::new(&store, &signature, |args| {
/// let sum = args[0].unwrap_i32() + args[1].unwrap_i32();
/// Ok(vec![Value::I32(sum)])
/// });
/// ```
///
/// With constant signature:
///
/// ```
/// # use wasmer::{Function, FunctionType, Type, Store, Value};
/// # let store = Store::default();
/// #
/// const I32_I32_TO_I32: ([Type; 2], [Type; 1]) = ([Type::I32, Type::I32], [Type::I32]);
///
/// let f = Function::new(&store, I32_I32_TO_I32, |args| {
/// let sum = args[0].unwrap_i32() + args[1].unwrap_i32();
/// Ok(vec![Value::I32(sum)])
/// });
/// ```
#[allow(clippy::cast_ptr_alignment)]
pub fn new<FT, F>(store: &Store, ty: FT, func: F) -> Self
where
FT: Into<FunctionType>,
F: Fn(&[Val]) -> Result<Vec<Val>, RuntimeError> + 'static + Send + Sync,
{
let wrapped_func =
move |_env: &WithoutEnv, args: &[Val]| -> Result<Vec<Val>, RuntimeError> { func(args) };
Self::new_with_env(store, ty, WithoutEnv, wrapped_func)
}
/// Creates a new host `Function` (dynamic) with the provided signature and environment.
///
/// If you know the signature of the host function at compile time,
/// consider using [`Function::new_native_with_env`] for less runtime
/// overhead.
///
/// # Examples
///
/// ```
/// # use wasmer::{Function, FunctionType, Type, Store, Value, WasmerEnv};
/// # let store = Store::default();
/// #
/// #[derive(WasmerEnv, Clone)]
/// struct Env {
/// multiplier: i32,
/// };
/// let env = Env { multiplier: 2 };
///
/// let signature = FunctionType::new(vec![Type::I32, Type::I32], vec![Type::I32]);
///
/// let f = Function::new_with_env(&store, &signature, env, |env, args| {
/// let result = env.multiplier * (args[0].unwrap_i32() + args[1].unwrap_i32());
/// Ok(vec![Value::I32(result)])
/// });
/// ```
///
/// With constant signature:
///
/// ```
/// # use wasmer::{Function, FunctionType, Type, Store, Value, WasmerEnv};
/// # let store = Store::default();
/// const I32_I32_TO_I32: ([Type; 2], [Type; 1]) = ([Type::I32, Type::I32], [Type::I32]);
///
/// #[derive(WasmerEnv, Clone)]
/// struct Env {
/// multiplier: i32,
/// };
/// let env = Env { multiplier: 2 };
///
/// let f = Function::new_with_env(&store, I32_I32_TO_I32, env, |env, args| {
/// let result = env.multiplier * (args[0].unwrap_i32() + args[1].unwrap_i32());
/// Ok(vec![Value::I32(result)])
/// });
/// ```
#[allow(clippy::cast_ptr_alignment)]
pub fn new_with_env<FT, F, Env>(store: &Store, ty: FT, env: Env, func: F) -> Self
where
FT: Into<FunctionType>,
F: Fn(&Env, &[Val]) -> Result<Vec<Val>, RuntimeError> + 'static + Send + Sync,
Env: Sized + WasmerEnv + 'static,
{
let ty: FunctionType = ty.into();
let dynamic_ctx: VMDynamicFunctionContext<DynamicFunction<Env>> =
VMDynamicFunctionContext::from_context(DynamicFunction {
env: Box::new(env),
func: Arc::new(func),
store: store.clone(),
function_type: ty.clone(),
});
let import_init_function_ptr: for<'a> fn(&'a mut _, &'a _) -> Result<(), _> =
|env: &mut VMDynamicFunctionContext<DynamicFunction<Env>>,
instance: &crate::Instance| {
Env::init_with_instance(&mut *env.ctx.env, instance)
};
let (host_env, metadata) = build_export_function_metadata::<
VMDynamicFunctionContext<DynamicFunction<Env>>,
>(dynamic_ctx, import_init_function_ptr);
// We don't yet have the address with the Wasm ABI signature.
// The engine linker will replace the address with one pointing to a
// generated dynamic trampoline.
let address = std::ptr::null() as *const VMFunctionBody;
let vmctx = VMFunctionEnvironment { host_env };
let signature = store
.engine()
// TODO(0-copy):
.register_signature((&ty).into());
Self {
store: store.clone(),
exported: ExportFunction {
metadata: Some(Arc::new(metadata)),
vm_function: VMFunction {
address,
kind: VMFunctionKind::Dynamic,
vmctx,
signature,
call_trampoline: None,
instance_ref: None,
},
},
}
}
/// Creates a new host `Function` from a native function.
///
/// The function signature is automatically retrieved using the
/// Rust typing system.
///
/// # Example
///
/// ```
/// # use wasmer::{Store, Function};
/// # let store = Store::default();
/// #
/// fn sum(a: i32, b: i32) -> i32 {
/// a + b
/// }
///
/// let f = Function::new_native(&store, sum);
/// ```
pub fn new_native<F, Args, Rets, Env>(store: &Store, func: F) -> Self
where
F: HostFunction<Args, Rets, WithoutEnv, Env>,
Args: WasmTypeList,
Rets: WasmTypeList,
Env: Sized + 'static,
{
if std::mem::size_of::<F>() != 0 {
Self::closures_unsupported_panic();
}
let function = inner::Function::<Args, Rets>::new(func);
let address = function.address() as *const VMFunctionBody;
let vmctx = VMFunctionEnvironment {
host_env: std::ptr::null_mut() as *mut _,
};
let signature = store
.engine()
// TODO(0-copy):
.register_signature((&function.ty()).into());
Self {
store: store.clone(),
exported: ExportFunction {
// TODO: figure out what's going on in this function: it takes an `Env`
// param but also marks itself as not having an env
metadata: None,
vm_function: VMFunction {
address,
vmctx,
signature,
kind: VMFunctionKind::Static,
call_trampoline: None,
instance_ref: None,
},
},
}
}
/// Creates a new host `Function` from a native function and a provided environment.
///
/// The function signature is automatically retrieved using the
/// Rust typing system.
///
/// # Example
///
/// ```
/// # use wasmer::{Store, Function, WasmerEnv};
/// # let store = Store::default();
/// #
/// #[derive(WasmerEnv, Clone)]
/// struct Env {
/// multiplier: i32,
/// };
/// let env = Env { multiplier: 2 };
///
/// fn sum_and_multiply(env: &Env, a: i32, b: i32) -> i32 {
/// (a + b) * env.multiplier
/// }
///
/// let f = Function::new_native_with_env(&store, env, sum_and_multiply);
/// ```
pub fn new_native_with_env<F, Args, Rets, Env>(store: &Store, env: Env, func: F) -> Self
where
F: HostFunction<Args, Rets, WithEnv, Env>,
Args: WasmTypeList,
Rets: WasmTypeList,
Env: Sized + WasmerEnv + 'static,
{
if std::mem::size_of::<F>() != 0 {
Self::closures_unsupported_panic();
}
let function = inner::Function::<Args, Rets>::new(func);
let address = function.address();
let (host_env, metadata) =
build_export_function_metadata::<Env>(env, Env::init_with_instance);
let vmctx = VMFunctionEnvironment { host_env };
let signature = store.engine().register_signature((&function.ty()).into());
Self {
store: store.clone(),
exported: ExportFunction {
metadata: Some(Arc::new(metadata)),
vm_function: VMFunction {
address,
kind: VMFunctionKind::Static,
vmctx,
signature,
call_trampoline: None,
instance_ref: None,
},
},
}
}
/// Returns the [`FunctionType`] of the `Function`.
///
/// # Example
///
/// ```
/// # use wasmer::{Function, Store, Type};
/// # let store = Store::default();
/// #
/// fn sum(a: i32, b: i32) -> i32 {
/// a + b
/// }
///
/// let f = Function::new_native(&store, sum);
///
/// assert_eq!(f.ty().params(), vec![Type::I32, Type::I32]);
/// assert_eq!(f.ty().results(), vec![Type::I32]);
/// ```
pub fn ty(&self) -> FunctionType {
self.store
.engine()
.lookup_signature(self.exported.vm_function.signature)
.expect("Could not resolve VMSharedFunctionIndex! Mixing engines?")
}
/// Returns the [`Store`] where the `Function` belongs.
pub fn store(&self) -> &Store {
&self.store
}
fn call_wasm(
&self,
trampoline: VMTrampoline,
params: &[Val],
results: &mut [Val],
) -> Result<(), RuntimeError> {
let format_types_for_error_message = |items: &[Val]| {
items
.iter()
.map(|param| param.ty().to_string())
.collect::<Vec<String>>()
.join(", ")
};
let signature = self.ty();
if signature.params().len() != params.len() {
return Err(RuntimeError::new(format!(
"Parameters of type [{}] did not match signature {}",
format_types_for_error_message(params),
&signature
)));
}
if signature.results().len() != results.len() {
return Err(RuntimeError::new(format!(
"Results of type [{}] did not match signature {}",
format_types_for_error_message(results),
&signature,
)));
}
let mut values_vec = vec![0; max(params.len(), results.len())];
// Store the argument values into `values_vec`.
let param_tys = signature.params().iter();
for ((arg, slot), ty) in params.iter().zip(&mut values_vec).zip(param_tys) {
if arg.ty() != *ty {
let param_types = format_types_for_error_message(params);
return Err(RuntimeError::new(format!(
"Parameters of type [{}] did not match signature {}",
param_types, &signature,
)));
}
unsafe {
arg.write_value_to(slot);
}
}
// Call the trampoline.
if let Err(error) = unsafe {
wasmer_call_trampoline(
self.exported.vm_function.vmctx,
trampoline,
self.exported.vm_function.address,
values_vec.as_mut_ptr() as *mut u8,
)
} {
return Err(RuntimeError::from_trap(error));
}
// Load the return values out of `values_vec`.
for (index, &value_type) in signature.results().iter().enumerate() {
unsafe {
let ptr = values_vec.as_ptr().add(index);
results[index] = Val::read_value_from(&self.store, ptr, value_type);
}
}
Ok(())
}
/// Returns the number of parameters that this function takes.
///
/// # Example
///
/// ```
/// # use wasmer::{Function, Store, Type};
/// # let store = Store::default();
/// #
/// fn sum(a: i32, b: i32) -> i32 {
/// a + b
/// }
///
/// let f = Function::new_native(&store, sum);
///
/// assert_eq!(f.param_arity(), 2);
/// ```
pub fn param_arity(&self) -> usize {
self.ty().params().len()
}
/// Returns the number of results this function produces.
///
/// # Example
///
/// ```
/// # use wasmer::{Function, Store, Type};
/// # let store = Store::default();
/// #
/// fn sum(a: i32, b: i32) -> i32 {
/// a + b
/// }
///
/// let f = Function::new_native(&store, sum);
///
/// assert_eq!(f.result_arity(), 1);
/// ```
pub fn result_arity(&self) -> usize {
self.ty().results().len()
}
/// Call the `Function` function.
///
/// Depending on where the Function is defined, it will call it.
/// 1. If the function is defined inside a WebAssembly, it will call the trampoline
/// for the function signature.
/// 2. If the function is defined in the host (in a native way), it will
/// call the trampoline.
///
/// # Examples
///
/// ```
/// # use wasmer::{imports, wat2wasm, Function, Instance, Module, Store, Type, Value};
/// # let store = Store::default();
/// # let wasm_bytes = wat2wasm(r#"
/// # (module
/// # (func (export "sum") (param $x i32) (param $y i32) (result i32)
/// # local.get $x
/// # local.get $y
/// # i32.add
/// # ))
/// # "#.as_bytes()).unwrap();
/// # let module = Module::new(&store, wasm_bytes).unwrap();
/// # let import_object = imports! {};
/// # let instance = Instance::new(&module, &import_object).unwrap();
/// #
/// let sum = instance.lookup_function("sum").unwrap();
///
/// assert_eq!(sum.call(&[Value::I32(1), Value::I32(2)]).unwrap().to_vec(), vec![Value::I32(3)]);
/// ```
pub fn call(&self, params: &[Val]) -> Result<Box<[Val]>, RuntimeError> {
// If it's a function defined in the Wasm, it will always have a call_trampoline
if let Some(trampoline) = self.exported.vm_function.call_trampoline {
let mut results = vec![Val::null(); self.result_arity()];
self.call_wasm(trampoline, params, &mut results)?;
return Ok(results.into_boxed_slice());
}
// If it's a function defined in the host
match self.exported.vm_function.kind {
VMFunctionKind::Dynamic => unsafe {
type VMContextWithEnv = VMDynamicFunctionContext<DynamicFunction<std::ffi::c_void>>;
let ctx = self.exported.vm_function.vmctx.host_env as *mut VMContextWithEnv;
Ok((*ctx).ctx.call(¶ms)?.into_boxed_slice())
},
VMFunctionKind::Static => {
unimplemented!(
"Native function definitions can't be directly called from the host yet"
);
}
}
}
pub(crate) fn from_vm_export(store: &Store, wasmer_export: ExportFunction) -> Self {
Self {
store: store.clone(),
exported: wasmer_export,
}
}
pub(crate) fn vm_funcref(&self) -> VMFuncRef {
let engine = self.store.engine();
engine.register_function_metadata(VMCallerCheckedAnyfunc {
func_ptr: self.exported.vm_function.address,
type_index: self.exported.vm_function.signature,
vmctx: self.exported.vm_function.vmctx,
})
}
/// Transform this WebAssembly function into a function with the
/// native ABI. See [`NativeFunc`] to learn more.
///
/// # Examples
///
/// ```
/// # use wasmer::{imports, wat2wasm, Function, Instance, Module, Store, Type, Value};
/// # let store = Store::default();
/// # let wasm_bytes = wat2wasm(r#"
/// # (module
/// # (func (export "sum") (param $x i32) (param $y i32) (result i32)
/// # local.get $x
/// # local.get $y
/// # i32.add
/// # ))
/// # "#.as_bytes()).unwrap();
/// # let module = Module::new(&store, wasm_bytes).unwrap();
/// # let import_object = imports! {};
/// # let instance = Instance::new(&module, &import_object).unwrap();
/// #
/// let sum = instance.lookup_function("sum").unwrap();
/// let sum_native = sum.native::<(i32, i32), i32>().unwrap();
///
/// assert_eq!(sum_native.call(1, 2).unwrap(), 3);
/// ```
///
/// # Errors
///
/// If the `Args` generic parameter does not match the exported function
/// an error will be raised:
///
/// ```should_panic
/// # use wasmer::{imports, wat2wasm, Function, Instance, Module, Store, Type, Value};
/// # let store = Store::default();
/// # let wasm_bytes = wat2wasm(r#"
/// # (module
/// # (func (export "sum") (param $x i32) (param $y i32) (result i32)
/// # local.get $x
/// # local.get $y
/// # i32.add
/// # ))
/// # "#.as_bytes()).unwrap();
/// # let module = Module::new(&store, wasm_bytes).unwrap();
/// # let import_object = imports! {};
/// # let instance = Instance::new(&module, &import_object).unwrap();
/// #
/// let sum = instance.lookup_function("sum").unwrap();
///
/// // This results in an error: `RuntimeError`
/// let sum_native = sum.native::<(i64, i64), i32>().unwrap();
/// ```
///
/// If the `Rets` generic parameter does not match the exported function
/// an error will be raised:
///
/// ```should_panic
/// # use wasmer::{imports, wat2wasm, Function, Instance, Module, Store, Type, Value};
/// # let store = Store::default();
/// # let wasm_bytes = wat2wasm(r#"
/// # (module
/// # (func (export "sum") (param $x i32) (param $y i32) (result i32)
/// # local.get $x
/// # local.get $y
/// # i32.add
/// # ))
/// # "#.as_bytes()).unwrap();
/// # let module = Module::new(&store, wasm_bytes).unwrap();
/// # let import_object = imports! {};
/// # let instance = Instance::new(&module, &import_object).unwrap();
/// #
/// let sum = instance.lookup_function("sum").unwrap();
///
/// // This results in an error: `RuntimeError`
/// let sum_native = sum.native::<(i32, i32), i64>().unwrap();
/// ```
pub fn native<Args, Rets>(&self) -> Result<NativeFunc<Args, Rets>, RuntimeError>
where
Args: WasmTypeList,
Rets: WasmTypeList,
{
let engine = self.store().engine();
let signature = engine
.lookup_signature(self.exported.vm_function.signature)
.expect("Could not resolve VMSharedSignatureIndex! Wrong engine?");
// type check
let expected = signature.params();
let given = Args::wasm_types();
if expected != given {
return Err(RuntimeError::new(format!(
"types (`{:?}`) for the function arguments don't match the actual types (`{:?}`)",
given, expected,
)));
}
let expected = signature.results();
let given = Rets::wasm_types();
if expected != given {
// todo: error result types don't match
return Err(RuntimeError::new(format!(
"types (`{:?}`) for the function results don't match the actual types (`{:?}`)",
given, expected,
)));
}
Ok(NativeFunc::new(self.store.clone(), self.exported.clone()))
}
#[track_caller]
fn closures_unsupported_panic() -> ! {
unimplemented!("Closures (functions with captured environments) are currently unsupported with native functions. See: https://github.com/wasmerio/wasmer/issues/1840")
}
/// Get access to the backing VM value for this extern. This function is for
/// tests it should not be called by users of the Wasmer API.
///
/// # Safety
/// This function is unsafe to call outside of tests for the wasmer crate
/// because there is no stability guarantee for the returned type and we may
/// make breaking changes to it at any time or remove this method.
#[doc(hidden)]
pub unsafe fn get_vm_function(&self) -> &VMFunction {
&self.exported.vm_function
}
}
impl<'a> Exportable<'a> for Function {
fn to_export(&self) -> Export {
self.exported.clone().into()
}
fn get_self_from_extern(_extern: Extern) -> Result<Self, ExportError> {
match _extern {
Extern::Function(func) => Ok(func),
_ => Err(ExportError::IncompatibleType),
}
}
fn into_weak_instance_ref(&mut self) {
self.exported
.vm_function
.instance_ref
.as_mut()
.map(|v| *v = v.downgrade());
}
}
impl Clone for Function {
fn clone(&self) -> Self {
let mut exported = self.exported.clone();
exported.vm_function.upgrade_instance_ref().unwrap();
Self {
store: self.store.clone(),
exported,
}
}
}
impl fmt::Debug for Function {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter
.debug_struct("Function")
.field("ty", &self.ty())
.finish()
}
}
/// This trait is one that all dynamic functions must fulfill.
pub(crate) trait VMDynamicFunction: Send + Sync {
fn call(&self, args: &[Val]) -> Result<Vec<Val>, RuntimeError>;
fn function_type(&self) -> &FunctionType;
fn store(&self) -> &Store;
}
pub(crate) struct DynamicFunction<Env>
where
Env: Sized + 'static + Send + Sync,
{
function_type: FunctionType,
#[allow(clippy::type_complexity)]
func: Arc<dyn Fn(&Env, &[Val]) -> Result<Vec<Val>, RuntimeError> + 'static + Send + Sync>,
store: Store,
env: Box<Env>,
}
impl<Env: Sized + Clone + 'static + Send + Sync> Clone for DynamicFunction<Env> {
fn clone(&self) -> Self {
Self {
env: self.env.clone(),
function_type: self.function_type.clone(),
store: self.store.clone(),
func: self.func.clone(),
}
}
}
impl<Env> VMDynamicFunction for DynamicFunction<Env>
where
Env: Sized + 'static + Send + Sync,
{
fn call(&self, args: &[Val]) -> Result<Vec<Val>, RuntimeError> {
(*self.func)(&*self.env, &args)
}
fn function_type(&self) -> &FunctionType {
&self.function_type
}
fn store(&self) -> &Store {
&self.store
}
}
trait VMDynamicFunctionCall<T: VMDynamicFunction> {
fn from_context(ctx: T) -> Self;
fn address_ptr() -> *const VMFunctionBody;
unsafe fn func_wrapper(&self, values_vec: *mut i128);
}
impl<T: VMDynamicFunction> VMDynamicFunctionCall<T> for VMDynamicFunctionContext<T> {
fn from_context(ctx: T) -> Self {
Self {
address: Self::address_ptr(),
ctx,
}
}
fn address_ptr() -> *const VMFunctionBody {
Self::func_wrapper as *const () as *const VMFunctionBody
}
// This function wraps our func, to make it compatible with the
// reverse trampoline signature
unsafe fn func_wrapper(
// Note: we use the trick that the first param to this function is the `VMDynamicFunctionContext`
// itself, so rather than doing `dynamic_ctx: &VMDynamicFunctionContext<T>`, we simplify it a bit
&self,
values_vec: *mut i128,
) {
use std::panic::{self, AssertUnwindSafe};
let result = panic::catch_unwind(AssertUnwindSafe(|| {
let func_ty = self.ctx.function_type();
let mut args = Vec::with_capacity(func_ty.params().len());
let store = self.ctx.store();
for (i, ty) in func_ty.params().iter().enumerate() {
args.push(Val::read_value_from(store, values_vec.add(i), *ty));
}
let returns = self.ctx.call(&args)?;
// We need to dynamically check that the returns
// match the expected types, as well as expected length.
let return_types = returns.iter().map(|ret| ret.ty()).collect::<Vec<_>>();
if return_types != func_ty.results() {
return Err(RuntimeError::new(format!(
"Dynamic function returned wrong signature. Expected {:?} but got {:?}",
func_ty.results(),
return_types
)));
}
for (i, ret) in returns.iter().enumerate() {
ret.write_value_to(values_vec.add(i));
}
Ok(())
})); // We get extern ref drops at the end of this block that we don't need.
// By preventing extern ref incs in the code above we can save the work of
// incrementing and decrementing. However the logic as-is is correct.
match result {
Ok(Ok(())) => {}
Ok(Err(trap)) => raise_user_trap(Box::new(trap)),
Err(panic) => resume_panic(panic),
}
}
}
/// This private inner module contains the low-level implementation
/// for `Function` and its siblings.
mod inner {
use std::array::TryFromSliceError;
use std::convert::{Infallible, TryInto};
use std::error::Error;
use std::marker::PhantomData;
use std::panic::{self, AssertUnwindSafe};
#[cfg(feature = "experimental-reference-types-extern-ref")]
pub use wasmer_types::{ExternRef, VMExternRef};
use wasmer_types::{FunctionType, NativeWasmType, Type};
use wasmer_vm::{raise_user_trap, resume_panic, VMFunctionBody};
/// A trait to convert a Rust value to a `WasmNativeType` value,
/// or to convert `WasmNativeType` value to a Rust value.
///
/// This trait should ideally be split into two traits:
/// `FromNativeWasmType` and `ToNativeWasmType` but it creates a
/// non-negligible complexity in the `WasmTypeList`
/// implementation.
pub unsafe trait FromToNativeWasmType
where
Self: Sized,
{
/// Native Wasm type.
type Native: NativeWasmType;
/// Convert a value of kind `Self::Native` to `Self`.
///
/// # Panics
///
/// This method panics if `native` cannot fit in the `Self`
/// type`.
fn from_native(native: Self::Native) -> Self;
/// Convert self to `Self::Native`.
///
/// # Panics
///
/// This method panics if `self` cannot fit in the
/// `Self::Native` type.
fn to_native(self) -> Self::Native;
}
macro_rules! from_to_native_wasm_type {
( $( $type:ty => $native_type:ty ),* ) => {
$(
#[allow(clippy::use_self)]
unsafe impl FromToNativeWasmType for $type {
type Native = $native_type;
#[inline]
fn from_native(native: Self::Native) -> Self {
native as Self
}
#[inline]
fn to_native(self) -> Self::Native {
self as Self::Native
}
}
)*
};
}
macro_rules! from_to_native_wasm_type_same_size {
( $( $type:ty => $native_type:ty ),* ) => {
$(
#[allow(clippy::use_self)]
unsafe impl FromToNativeWasmType for $type {
type Native = $native_type;
#[inline]
fn from_native(native: Self::Native) -> Self {
Self::from_ne_bytes(Self::Native::to_ne_bytes(native))
}
#[inline]
fn to_native(self) -> Self::Native {
Self::Native::from_ne_bytes(Self::to_ne_bytes(self))
}
}
)*
};
}
from_to_native_wasm_type!(
i8 => i32,
u8 => i32,
i16 => i32,
u16 => i32
);
from_to_native_wasm_type_same_size!(
i32 => i32,
u32 => i32,
i64 => i64,
u64 => i64,
f32 => f32,
f64 => f64
);
#[cfg(feature = "experimental-reference-types-extern-ref")]
unsafe impl FromToNativeWasmType for ExternRef {
type Native = VMExternRef;
fn to_native(self) -> Self::Native {
self.into()
}
fn from_native(n: Self::Native) -> Self {
n.into()
}
}
#[cfg(test)]
mod test_from_to_native_wasm_type {
use super::*;
#[test]
fn test_to_native() {
assert_eq!(7i8.to_native(), 7i32);
assert_eq!(7u8.to_native(), 7i32);
assert_eq!(7i16.to_native(), 7i32);
assert_eq!(7u16.to_native(), 7i32);
assert_eq!(u32::MAX.to_native(), -1);
}
#[test]
fn test_to_native_same_size() {
assert_eq!(7i32.to_native(), 7i32);
assert_eq!(7u32.to_native(), 7i32);
assert_eq!(7i64.to_native(), 7i64);
assert_eq!(7u64.to_native(), 7i64);
assert_eq!(7f32.to_native(), 7f32);
assert_eq!(7f64.to_native(), 7f64);
}
}
/// The `WasmTypeList` trait represents a tuple (list) of Wasm
/// typed values. It is used to get low-level representation of
/// such a tuple.
pub trait WasmTypeList
where
Self: Sized,
{
/// The C type (a struct) that can hold/represent all the
/// represented values.
type CStruct;
/// The array type that can hold all the represented values.
///
/// Note that all values are stored in their binary form.
type Array: AsMut<[i128]>;
/// Constructs `Self` based on an array of values.
fn from_array(array: Self::Array) -> Self;
/// Constructs `Self` based on a slice of values.
///
/// `from_slice` returns a `Result` because it is possible
/// that the slice doesn't have the same size than
/// `Self::Array`, in which circumstance an error of kind
/// `TryFromSliceError` will be returned.
fn from_slice(slice: &[i128]) -> Result<Self, TryFromSliceError>;
/// Builds and returns an array of type `Array` from a tuple
/// (list) of values.
fn into_array(self) -> Self::Array;
/// Allocates and return an empty array of type `Array` that
/// will hold a tuple (list) of values, usually to hold the
/// returned values of a WebAssembly function call.
fn empty_array() -> Self::Array;
/// Builds a tuple (list) of values from a C struct of type
/// `CStruct`.
fn from_c_struct(c_struct: Self::CStruct) -> Self;
/// Builds and returns a C struct of type `CStruct` from a
/// tuple (list) of values.
fn into_c_struct(self) -> Self::CStruct;
/// Get the Wasm types for the tuple (list) of currently
/// represented values.
fn wasm_types() -> &'static [Type];
}
/// The `IntoResult` trait turns a `WasmTypeList` into a
/// `Result<WasmTypeList, Self::Error>`.
///
/// It is mostly used to turn result values of a Wasm function
/// call into a `Result`.
pub trait IntoResult<T>
where
T: WasmTypeList,
{
/// The error type for this trait.
type Error: Error + Sync + Send + 'static;
/// Transforms `Self` into a `Result`.
fn into_result(self) -> Result<T, Self::Error>;
}
impl<T> IntoResult<T> for T
where
T: WasmTypeList,
{
// `T` is not a `Result`, it's already a value, so no error
// can be built.
type Error = Infallible;
fn into_result(self) -> Result<Self, Infallible> {
Ok(self)
}
}
impl<T, E> IntoResult<T> for Result<T, E>
where
T: WasmTypeList,
E: Error + Sync + Send + 'static,
{
type Error = E;
fn into_result(self) -> Self {
self
}
}
#[cfg(test)]
mod test_into_result {
use super::*;
use std::convert::Infallible;
#[test]
fn test_into_result_over_t() {
let x: i32 = 42;
let result_of_x: Result<i32, Infallible> = x.into_result();
assert_eq!(result_of_x.unwrap(), x);
}
#[test]
fn test_into_result_over_result() {
{
let x: Result<i32, Infallible> = Ok(42);
let result_of_x: Result<i32, Infallible> = x.into_result();
assert_eq!(result_of_x, x);
}
{
use std::{error, fmt};
#[derive(Debug, PartialEq)]
struct E;
impl fmt::Display for E {
fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(formatter, "E")
}
}
impl error::Error for E {}
let x: Result<Infallible, E> = Err(E);
let result_of_x: Result<Infallible, E> = x.into_result();
assert_eq!(result_of_x.unwrap_err(), E);
}
}
}
/// The `HostFunction` trait represents the set of functions that
/// can be used as host function. To uphold this statement, it is
/// necessary for a function to be transformed into a pointer to
/// `VMFunctionBody`.
pub trait HostFunction<Args, Rets, Kind, T>
where
Args: WasmTypeList,
Rets: WasmTypeList,
Kind: HostFunctionKind,
T: Sized,
Self: Sized,
{
/// Get the pointer to the function body.
fn function_body_ptr(self) -> *const VMFunctionBody;
}
/// Empty trait to specify the kind of `HostFunction`: With or
/// without an environment.
///
/// This trait is never aimed to be used by a user. It is used by
/// the trait system to automatically generate the appropriate
/// host functions.
#[doc(hidden)]
pub trait HostFunctionKind {}
/// An empty struct to help Rust typing to determine
/// when a `HostFunction` does have an environment.
pub struct WithEnv;
impl HostFunctionKind for WithEnv {}
/// An empty struct to help Rust typing to determine
/// when a `HostFunction` does not have an environment.
#[derive(Clone)]
pub struct WithoutEnv;
impl HostFunctionKind for WithoutEnv {}
/// Represents a low-level Wasm static host function. See
/// `super::Function::new` and `super::Function::new_env` to learn
/// more.
#[derive(Clone, Debug, Hash, PartialEq, Eq)]
pub struct Function<Args = (), Rets = ()> {
address: *const VMFunctionBody,
_phantom: PhantomData<(Args, Rets)>,
}
unsafe impl<Args, Rets> Send for Function<Args, Rets> {}
impl<Args, Rets> Function<Args, Rets>
where
Args: WasmTypeList,
Rets: WasmTypeList,
{
/// Creates a new `Function`.
pub fn new<F, T, E>(function: F) -> Self
where
F: HostFunction<Args, Rets, T, E>,
T: HostFunctionKind,
E: Sized,
{
Self {
address: function.function_body_ptr(),
_phantom: PhantomData,
}
}
/// Get the function type of this `Function`.
pub fn ty(&self) -> FunctionType {
FunctionType::new(Args::wasm_types(), Rets::wasm_types())
}
/// Get the address of this `Function`.
pub fn address(&self) -> *const VMFunctionBody {
self.address
}
}
macro_rules! impl_host_function {
( [$c_struct_representation:ident]
$c_struct_name:ident,
$( $x:ident ),* ) => {
/// A structure with a C-compatible representation that can hold a set of Wasm values.
/// This type is used by `WasmTypeList::CStruct`.
#[repr($c_struct_representation)]
pub struct $c_struct_name< $( $x ),* > ( $( <$x as FromToNativeWasmType>::Native ),* )
where
$( $x: FromToNativeWasmType ),*;
// Implement `WasmTypeList` for a specific tuple.
#[allow(unused_parens, dead_code)]
impl< $( $x ),* >
WasmTypeList
for
( $( $x ),* )
where
$( $x: FromToNativeWasmType ),*
{
type CStruct = $c_struct_name< $( $x ),* >;
type Array = [i128; count_idents!( $( $x ),* )];
fn from_array(array: Self::Array) -> Self {
// Unpack items of the array.
#[allow(non_snake_case)]
let [ $( $x ),* ] = array;
// Build the tuple.
(
$(
FromToNativeWasmType::from_native(NativeWasmType::from_binary($x))
),*
)
}
fn from_slice(slice: &[i128]) -> Result<Self, TryFromSliceError> {
Ok(Self::from_array(slice.try_into()?))
}
fn into_array(self) -> Self::Array {
// Unpack items of the tuple.
#[allow(non_snake_case)]
let ( $( $x ),* ) = self;
// Build the array.
[
$(
FromToNativeWasmType::to_native($x).to_binary()
),*
]
}
fn empty_array() -> Self::Array {
// Build an array initialized with `0`.
[0; count_idents!( $( $x ),* )]
}
fn from_c_struct(c_struct: Self::CStruct) -> Self {
// Unpack items of the C structure.
#[allow(non_snake_case)]
let $c_struct_name( $( $x ),* ) = c_struct;
(
$(
FromToNativeWasmType::from_native($x)
),*
)
}
#[allow(unused_parens, non_snake_case)]
fn into_c_struct(self) -> Self::CStruct {
// Unpack items of the tuple.
let ( $( $x ),* ) = self;
// Build the C structure.
$c_struct_name(
$(
FromToNativeWasmType::to_native($x)
),*
)
}
fn wasm_types() -> &'static [Type] {
&[
$(
$x::Native::WASM_TYPE
),*
]
}
}
// Implement `HostFunction` for a function that has the same arity than the tuple.
// This specific function has no environment.
#[allow(unused_parens)]
impl< $( $x, )* Rets, RetsAsResult, Func >
HostFunction<( $( $x ),* ), Rets, WithoutEnv, ()>
for
Func
where
$( $x: FromToNativeWasmType, )*
Rets: WasmTypeList,
RetsAsResult: IntoResult<Rets>,
Func: Fn($( $x , )*) -> RetsAsResult + 'static + Send,
{
#[allow(non_snake_case)]
fn function_body_ptr(self) -> *const VMFunctionBody {
/// This is a function that wraps the real host
/// function. Its address will be used inside the
/// runtime.
extern fn func_wrapper<$( $x, )* Rets, RetsAsResult, Func>( _: usize, $( $x: $x::Native, )* ) -> Rets::CStruct
where
$( $x: FromToNativeWasmType, )*
Rets: WasmTypeList,
RetsAsResult: IntoResult<Rets>,
Func: Fn( $( $x ),* ) -> RetsAsResult + 'static
{
let func: &Func = unsafe { &*(&() as *const () as *const Func) };
let result = panic::catch_unwind(AssertUnwindSafe(|| {
func( $( FromToNativeWasmType::from_native($x) ),* ).into_result()
}));
match result {
Ok(Ok(result)) => return result.into_c_struct(),
Ok(Err(trap)) => unsafe { raise_user_trap(Box::new(trap)) },
Err(panic) => unsafe { resume_panic(panic) },
}
}
func_wrapper::< $( $x, )* Rets, RetsAsResult, Self > as *const VMFunctionBody
}
}
// Implement `HostFunction` for a function that has the same arity than the tuple.
// This specific function has an environment.
#[allow(unused_parens)]
impl< $( $x, )* Rets, RetsAsResult, Env, Func >
HostFunction<( $( $x ),* ), Rets, WithEnv, Env>
for
Func
where
$( $x: FromToNativeWasmType, )*
Rets: WasmTypeList,
RetsAsResult: IntoResult<Rets>,
Env: Sized,
Func: Fn(&Env, $( $x , )*) -> RetsAsResult + Send + 'static,
{
#[allow(non_snake_case)]
fn function_body_ptr(self) -> *const VMFunctionBody {
/// This is a function that wraps the real host
/// function. Its address will be used inside the
/// runtime.
extern fn func_wrapper<$( $x, )* Rets, RetsAsResult, Env, Func>( env: &Env, $( $x: $x::Native, )* ) -> Rets::CStruct
where
$( $x: FromToNativeWasmType, )*
Rets: WasmTypeList,
RetsAsResult: IntoResult<Rets>,
Env: Sized,
Func: Fn(&Env, $( $x ),* ) -> RetsAsResult + 'static
{
let func: &Func = unsafe { &*(&() as *const () as *const Func) };
let result = panic::catch_unwind(AssertUnwindSafe(|| {
func(env, $( FromToNativeWasmType::from_native($x) ),* ).into_result()
}));
match result {
Ok(Ok(result)) => return result.into_c_struct(),
Ok(Err(trap)) => unsafe { raise_user_trap(Box::new(trap)) },
Err(panic) => unsafe { resume_panic(panic) },
}
}
func_wrapper::< $( $x, )* Rets, RetsAsResult, Env, Self > as *const VMFunctionBody
}
}
};
}
// Black-magic to count the number of identifiers at compile-time.
macro_rules! count_idents {
( $($idents:ident),* ) => {
{
#[allow(dead_code, non_camel_case_types)]
enum Idents { $( $idents, )* __CountIdentsLast }
const COUNT: usize = Idents::__CountIdentsLast as usize;
COUNT
}
};
}
// Here we go! Let's generate all the C struct, `WasmTypeList`
// implementations and `HostFunction` implementations.
impl_host_function!([C] S0,);
impl_host_function!([transparent] S1, A1);
impl_host_function!([C] S2, A1, A2);
impl_host_function!([C] S3, A1, A2, A3);
impl_host_function!([C] S4, A1, A2, A3, A4);
impl_host_function!([C] S5, A1, A2, A3, A4, A5);
impl_host_function!([C] S6, A1, A2, A3, A4, A5, A6);
impl_host_function!([C] S7, A1, A2, A3, A4, A5, A6, A7);
impl_host_function!([C] S8, A1, A2, A3, A4, A5, A6, A7, A8);
impl_host_function!([C] S9, A1, A2, A3, A4, A5, A6, A7, A8, A9);
impl_host_function!([C] S10, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10);
impl_host_function!([C] S11, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11);
impl_host_function!([C] S12, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12);
impl_host_function!([C] S13, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13);
impl_host_function!([C] S14, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14);
impl_host_function!([C] S15, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15);
impl_host_function!([C] S16, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16);
impl_host_function!([C] S17, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17);
impl_host_function!([C] S18, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18);
impl_host_function!([C] S19, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19);
impl_host_function!([C] S20, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20);
impl_host_function!([C] S21, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21);
impl_host_function!([C] S22, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22);
impl_host_function!([C] S23, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23);
impl_host_function!([C] S24, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24);
impl_host_function!([C] S25, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25);
impl_host_function!([C] S26, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26);
// Implement `WasmTypeList` on `Infallible`, which means that
// `Infallible` can be used as a returned type of a host function
// to express that it doesn't return, or to express that it cannot
// fail (with `Result<_, Infallible>`).
impl WasmTypeList for Infallible {
type CStruct = Self;
type Array = [i128; 0];
fn from_array(_: Self::Array) -> Self {
unreachable!()
}
fn from_slice(_: &[i128]) -> Result<Self, TryFromSliceError> {
unreachable!()
}
fn into_array(self) -> Self::Array {
[]
}
fn empty_array() -> Self::Array {
unreachable!()
}
fn from_c_struct(_: Self::CStruct) -> Self {
unreachable!()
}
fn into_c_struct(self) -> Self::CStruct {
unreachable!()
}
fn wasm_types() -> &'static [Type] {
&[]
}
}
#[cfg(test)]
mod test_wasm_type_list {
use super::*;
use wasmer_types::Type;
#[test]
fn test_from_array() {
assert_eq!(<()>::from_array([]), ());
assert_eq!(<i32>::from_array([1]), (1i32));
assert_eq!(<(i32, i64)>::from_array([1, 2]), (1i32, 2i64));
assert_eq!(
<(i32, i64, f32, f64)>::from_array([
1,
2,
(3.1f32).to_bits().into(),
(4.2f64).to_bits().into()
]),
(1, 2, 3.1f32, 4.2f64)
);
}
#[test]
fn test_into_array() {
assert_eq!(().into_array(), [0i128; 0]);
assert_eq!((1).into_array(), [1]);
assert_eq!((1i32, 2i64).into_array(), [1, 2]);
assert_eq!(
(1i32, 2i32, 3.1f32, 4.2f64).into_array(),
[1, 2, (3.1f32).to_bits().into(), (4.2f64).to_bits().into()]
);
}
#[test]
fn test_empty_array() {
assert_eq!(<()>::empty_array().len(), 0);
assert_eq!(<i32>::empty_array().len(), 1);
assert_eq!(<(i32, i64)>::empty_array().len(), 2);
}
#[test]
fn test_from_c_struct() {
assert_eq!(<()>::from_c_struct(S0()), ());
assert_eq!(<i32>::from_c_struct(S1(1)), (1i32));
assert_eq!(<(i32, i64)>::from_c_struct(S2(1, 2)), (1i32, 2i64));
assert_eq!(
<(i32, i64, f32, f64)>::from_c_struct(S4(1, 2, 3.1, 4.2)),
(1i32, 2i64, 3.1f32, 4.2f64)
);
}
#[test]
fn test_wasm_types_for_uni_values() {
assert_eq!(<i32>::wasm_types(), [Type::I32]);
assert_eq!(<i64>::wasm_types(), [Type::I64]);
assert_eq!(<f32>::wasm_types(), [Type::F32]);
assert_eq!(<f64>::wasm_types(), [Type::F64]);
}
#[test]
fn test_wasm_types_for_multi_values() {
assert_eq!(<(i32, i32)>::wasm_types(), [Type::I32, Type::I32]);
assert_eq!(<(i64, i64)>::wasm_types(), [Type::I64, Type::I64]);
assert_eq!(<(f32, f32)>::wasm_types(), [Type::F32, Type::F32]);
assert_eq!(<(f64, f64)>::wasm_types(), [Type::F64, Type::F64]);
assert_eq!(
<(i32, i64, f32, f64)>::wasm_types(),
[Type::I32, Type::I64, Type::F32, Type::F64]
);
}
}
#[allow(non_snake_case)]
#[cfg(test)]
mod test_function {
use super::*;
use wasmer_types::Type;
fn func() {}
fn func__i32() -> i32 {
0
}
fn func_i32(_a: i32) {}
fn func_i32__i32(a: i32) -> i32 {
a * 2
}
fn func_i32_i32__i32(a: i32, b: i32) -> i32 {
a + b
}
fn func_i32_i32__i32_i32(a: i32, b: i32) -> (i32, i32) {
(a, b)
}
fn func_f32_i32__i32_f32(a: f32, b: i32) -> (i32, f32) {
(b, a)
}
#[test]
fn test_function_types() {
assert_eq!(Function::new(func).ty(), FunctionType::new(vec![], vec![]));
assert_eq!(
Function::new(func__i32).ty(),
FunctionType::new(vec![], vec![Type::I32])
);
assert_eq!(
Function::new(func_i32).ty(),
FunctionType::new(vec![Type::I32], vec![])
);
assert_eq!(
Function::new(func_i32__i32).ty(),
FunctionType::new(vec![Type::I32], vec![Type::I32])
);
assert_eq!(
Function::new(func_i32_i32__i32).ty(),
FunctionType::new(vec![Type::I32, Type::I32], vec![Type::I32])
);
assert_eq!(
Function::new(func_i32_i32__i32_i32).ty(),
FunctionType::new(vec![Type::I32, Type::I32], vec![Type::I32, Type::I32])
);
assert_eq!(
Function::new(func_f32_i32__i32_f32).ty(),
FunctionType::new(vec![Type::F32, Type::I32], vec![Type::I32, Type::F32])
);
}
#[test]
fn test_function_pointer() {
let f = Function::new(func_i32__i32);
let function = unsafe { std::mem::transmute::<_, fn(usize, i32) -> i32>(f.address) };
assert_eq!(function(0, 3), 6);
}
}
}