refactor(ext/ffi): split into multiple parts (#16950)

- [x] `dlfcn.rs` - `dlopen()`-related code.
- [x] `turbocall.rs` - Call trampoline JIT compiler. 
- [x] `repr.rs` - Pointer representation. Home of the UnsafePointerView
ops.
- [x] `symbol.rs` - Function symbol related code.
- [x] `callback.rs` - Home of `Deno.UnsafeCallback` ops.
- [x] `ir.rs` - Intermediate representation for values. Home of the
`NativeValue` type.
- [x] `call.rs` - Generic call ops. Home to everything related to
calling FFI symbols.
- [x] `static.rs` - static symbol support

I find easier to work with this setup, I eventually want to expand
TurboCall to unroll type conversion loop in generic calls, generate code
for individual symbols (lazy function pointers), etc.

ext/ffi/call.rs

@@ -0,0 +1,335 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::callback::PtrSymbol;
+use crate::check_unstable2;
+use crate::dlfcn::DynamicLibraryResource;
+use crate::ir::*;
+use crate::symbol::NativeType;
+use crate::symbol::Symbol;
+use crate::FfiPermissions;
+use crate::ForeignFunction;
+use deno_core::anyhow::anyhow;
+use deno_core::error::type_error;
+use deno_core::error::AnyError;
+use deno_core::op;
+use deno_core::serde_json::Value;
+use deno_core::serde_v8;
+use deno_core::v8;
+use deno_core::ResourceId;
+use libffi::middle::Arg;
+use std::cell::RefCell;
+use std::ffi::c_void;
+use std::future::Future;
+use std::rc::Rc;
+
+// A one-off synchronous FFI call.
+pub(crate) fn ffi_call_sync<'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  args: v8::FunctionCallbackArguments,
+  symbol: &Symbol,
+) -> Result<NativeValue, AnyError>
+where
+  'scope: 'scope,
+{
+  let Symbol {
+    parameter_types,
+    result_type,
+    cif,
+    ptr: fun_ptr,
+    ..
+  } = symbol;
+  let mut ffi_args: Vec<NativeValue> =
+    Vec::with_capacity(parameter_types.len());
+
+  for (index, native_type) in parameter_types.iter().enumerate() {
+    let value = args.get(index as i32);
+    match native_type {
+      NativeType::Bool => {
+        ffi_args.push(ffi_parse_bool_arg(value)?);
+      }
+      NativeType::U8 => {
+        ffi_args.push(ffi_parse_u8_arg(value)?);
+      }
+      NativeType::I8 => {
+        ffi_args.push(ffi_parse_i8_arg(value)?);
+      }
+      NativeType::U16 => {
+        ffi_args.push(ffi_parse_u16_arg(value)?);
+      }
+      NativeType::I16 => {
+        ffi_args.push(ffi_parse_i16_arg(value)?);
+      }
+      NativeType::U32 => {
+        ffi_args.push(ffi_parse_u32_arg(value)?);
+      }
+      NativeType::I32 => {
+        ffi_args.push(ffi_parse_i32_arg(value)?);
+      }
+      NativeType::U64 => {
+        ffi_args.push(ffi_parse_u64_arg(scope, value)?);
+      }
+      NativeType::I64 => {
+        ffi_args.push(ffi_parse_i64_arg(scope, value)?);
+      }
+      NativeType::USize => {
+        ffi_args.push(ffi_parse_usize_arg(scope, value)?);
+      }
+      NativeType::ISize => {
+        ffi_args.push(ffi_parse_isize_arg(scope, value)?);
+      }
+      NativeType::F32 => {
+        ffi_args.push(ffi_parse_f32_arg(value)?);
+      }
+      NativeType::F64 => {
+        ffi_args.push(ffi_parse_f64_arg(value)?);
+      }
+      NativeType::Buffer => {
+        ffi_args.push(ffi_parse_buffer_arg(scope, value)?);
+      }
+      NativeType::Pointer => {
+        ffi_args.push(ffi_parse_pointer_arg(scope, value)?);
+      }
+      NativeType::Function => {
+        ffi_args.push(ffi_parse_function_arg(scope, value)?);
+      }
+      NativeType::Void => {
+        unreachable!();
+      }
+    }
+  }
+  let call_args: Vec<Arg> = ffi_args.iter().map(Arg::new).collect();
+  // SAFETY: types in the `Cif` match the actual calling convention and
+  // types of symbol.
+  unsafe {
+    Ok(match result_type {
+      NativeType::Void => NativeValue {
+        void_value: cif.call::<()>(*fun_ptr, &call_args),
+      },
+      NativeType::Bool => NativeValue {
+        bool_value: cif.call::<bool>(*fun_ptr, &call_args),
+      },
+      NativeType::U8 => NativeValue {
+        u8_value: cif.call::<u8>(*fun_ptr, &call_args),
+      },
+      NativeType::I8 => NativeValue {
+        i8_value: cif.call::<i8>(*fun_ptr, &call_args),
+      },
+      NativeType::U16 => NativeValue {
+        u16_value: cif.call::<u16>(*fun_ptr, &call_args),
+      },
+      NativeType::I16 => NativeValue {
+        i16_value: cif.call::<i16>(*fun_ptr, &call_args),
+      },
+      NativeType::U32 => NativeValue {
+        u32_value: cif.call::<u32>(*fun_ptr, &call_args),
+      },
+      NativeType::I32 => NativeValue {
+        i32_value: cif.call::<i32>(*fun_ptr, &call_args),
+      },
+      NativeType::U64 => NativeValue {
+        u64_value: cif.call::<u64>(*fun_ptr, &call_args),
+      },
+      NativeType::I64 => NativeValue {
+        i64_value: cif.call::<i64>(*fun_ptr, &call_args),
+      },
+      NativeType::USize => NativeValue {
+        usize_value: cif.call::<usize>(*fun_ptr, &call_args),
+      },
+      NativeType::ISize => NativeValue {
+        isize_value: cif.call::<isize>(*fun_ptr, &call_args),
+      },
+      NativeType::F32 => NativeValue {
+        f32_value: cif.call::<f32>(*fun_ptr, &call_args),
+      },
+      NativeType::F64 => NativeValue {
+        f64_value: cif.call::<f64>(*fun_ptr, &call_args),
+      },
+      NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
+        NativeValue {
+          pointer: cif.call::<*mut c_void>(*fun_ptr, &call_args),
+        }
+      }
+    })
+  }
+}
+
+fn ffi_call(
+  call_args: Vec<NativeValue>,
+  cif: &libffi::middle::Cif,
+  fun_ptr: libffi::middle::CodePtr,
+  parameter_types: &[NativeType],
+  result_type: NativeType,
+) -> Result<NativeValue, AnyError> {
+  let call_args: Vec<Arg> = call_args
+    .iter()
+    .enumerate()
+    .map(|(index, ffi_arg)| {
+      // SAFETY: the union field is initialized
+      unsafe { ffi_arg.as_arg(*parameter_types.get(index).unwrap()) }
+    })
+    .collect();
+
+  // SAFETY: types in the `Cif` match the actual calling convention and
+  // types of symbol.
+  unsafe {
+    Ok(match result_type {
+      NativeType::Void => NativeValue {
+        void_value: cif.call::<()>(fun_ptr, &call_args),
+      },
+      NativeType::Bool => NativeValue {
+        bool_value: cif.call::<bool>(fun_ptr, &call_args),
+      },
+      NativeType::U8 => NativeValue {
+        u8_value: cif.call::<u8>(fun_ptr, &call_args),
+      },
+      NativeType::I8 => NativeValue {
+        i8_value: cif.call::<i8>(fun_ptr, &call_args),
+      },
+      NativeType::U16 => NativeValue {
+        u16_value: cif.call::<u16>(fun_ptr, &call_args),
+      },
+      NativeType::I16 => NativeValue {
+        i16_value: cif.call::<i16>(fun_ptr, &call_args),
+      },
+      NativeType::U32 => NativeValue {
+        u32_value: cif.call::<u32>(fun_ptr, &call_args),
+      },
+      NativeType::I32 => NativeValue {
+        i32_value: cif.call::<i32>(fun_ptr, &call_args),
+      },
+      NativeType::U64 => NativeValue {
+        u64_value: cif.call::<u64>(fun_ptr, &call_args),
+      },
+      NativeType::I64 => NativeValue {
+        i64_value: cif.call::<i64>(fun_ptr, &call_args),
+      },
+      NativeType::USize => NativeValue {
+        usize_value: cif.call::<usize>(fun_ptr, &call_args),
+      },
+      NativeType::ISize => NativeValue {
+        isize_value: cif.call::<isize>(fun_ptr, &call_args),
+      },
+      NativeType::F32 => NativeValue {
+        f32_value: cif.call::<f32>(fun_ptr, &call_args),
+      },
+      NativeType::F64 => NativeValue {
+        f64_value: cif.call::<f64>(fun_ptr, &call_args),
+      },
+      NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
+        NativeValue {
+          pointer: cif.call::<*mut c_void>(fun_ptr, &call_args),
+        }
+      }
+    })
+  }
+}
+
+#[op(v8)]
+pub fn op_ffi_call_ptr_nonblocking<'scope, FP>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: Rc<RefCell<deno_core::OpState>>,
+  pointer: usize,
+  def: ForeignFunction,
+  parameters: serde_v8::Value<'scope>,
+) -> Result<impl Future<Output = Result<Value, AnyError>>, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable2(&state, "Deno.UnsafeFnPointer#call");
+  {
+    let mut state = state.borrow_mut();
+    let permissions = state.borrow_mut::<FP>();
+    permissions.check(None)?;
+  };
+
+  let symbol = PtrSymbol::new(pointer, &def);
+  let call_args = ffi_parse_args(scope, parameters, &def.parameters)?;
+
+  let join_handle = tokio::task::spawn_blocking(move || {
+    let PtrSymbol { cif, ptr } = symbol.clone();
+    ffi_call(call_args, &cif, ptr, &def.parameters, def.result)
+  });
+
+  Ok(async move {
+    let result = join_handle
+      .await
+      .map_err(|err| anyhow!("Nonblocking FFI call failed: {}", err))??;
+    // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
+    Ok(unsafe { result.to_value(def.result) })
+  })
+}
+
+/// A non-blocking FFI call.
+#[op(v8)]
+pub fn op_ffi_call_nonblocking<'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: Rc<RefCell<deno_core::OpState>>,
+  rid: ResourceId,
+  symbol: String,
+  parameters: serde_v8::Value<'scope>,
+) -> Result<impl Future<Output = Result<Value, AnyError>> + 'static, AnyError> {
+  let symbol = {
+    let state = state.borrow();
+    let resource = state.resource_table.get::<DynamicLibraryResource>(rid)?;
+    let symbols = &resource.symbols;
+    *symbols
+      .get(&symbol)
+      .ok_or_else(|| type_error("Invalid FFI symbol name"))?
+      .clone()
+  };
+
+  let call_args = ffi_parse_args(scope, parameters, &symbol.parameter_types)?;
+
+  let result_type = symbol.result_type;
+  let join_handle = tokio::task::spawn_blocking(move || {
+    let Symbol {
+      cif,
+      ptr,
+      parameter_types,
+      result_type,
+      ..
+    } = symbol.clone();
+    ffi_call(call_args, &cif, ptr, &parameter_types, result_type)
+  });
+
+  Ok(async move {
+    let result = join_handle
+      .await
+      .map_err(|err| anyhow!("Nonblocking FFI call failed: {}", err))??;
+    // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
+    Ok(unsafe { result.to_value(result_type) })
+  })
+}
+
+#[op(v8)]
+pub fn op_ffi_call_ptr<FP, 'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: Rc<RefCell<deno_core::OpState>>,
+  pointer: usize,
+  def: ForeignFunction,
+  parameters: serde_v8::Value<'scope>,
+) -> Result<serde_v8::Value<'scope>, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable2(&state, "Deno.UnsafeFnPointer#call");
+  {
+    let mut state = state.borrow_mut();
+    let permissions = state.borrow_mut::<FP>();
+    permissions.check(None)?;
+  };
+
+  let symbol = PtrSymbol::new(pointer, &def);
+  let call_args = ffi_parse_args(scope, parameters, &def.parameters)?;
+
+  let result = ffi_call(
+    call_args,
+    &symbol.cif,
+    symbol.ptr,
+    &def.parameters,
+    def.result,
+  )?;
+  // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
+  let result = unsafe { result.to_v8(scope, def.result) };
+  Ok(result)
+}

ext/ffi/callback.rs

@@ -0,0 +1,562 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::check_unstable;
+use crate::symbol::NativeType;
+use crate::FfiPermissions;
+use crate::FfiState;
+use crate::ForeignFunction;
+use crate::PendingFfiAsyncWork;
+use crate::LOCAL_ISOLATE_POINTER;
+use crate::MAX_SAFE_INTEGER;
+use crate::MIN_SAFE_INTEGER;
+use deno_core::error::AnyError;
+use deno_core::futures::channel::mpsc;
+use deno_core::op;
+use deno_core::serde_v8;
+use deno_core::v8;
+use deno_core::CancelFuture;
+use deno_core::CancelHandle;
+use deno_core::OpState;
+use deno_core::Resource;
+use deno_core::ResourceId;
+use libffi::middle::Cif;
+use serde::Deserialize;
+use std::borrow::Cow;
+use std::cell::RefCell;
+use std::ffi::c_void;
+use std::future::Future;
+use std::future::IntoFuture;
+use std::pin::Pin;
+use std::ptr;
+use std::ptr::NonNull;
+use std::rc::Rc;
+use std::sync::mpsc::sync_channel;
+use std::task::Poll;
+use std::task::Waker;
+#[derive(Clone)]
+pub struct PtrSymbol {
+  pub cif: libffi::middle::Cif,
+  pub ptr: libffi::middle::CodePtr,
+}
+
+impl PtrSymbol {
+  pub fn new(fn_ptr: usize, def: &ForeignFunction) -> Self {
+    let ptr = libffi::middle::CodePtr::from_ptr(fn_ptr as _);
+    let cif = libffi::middle::Cif::new(
+      def
+        .parameters
+        .clone()
+        .into_iter()
+        .map(libffi::middle::Type::from),
+      def.result.into(),
+    );
+
+    Self { cif, ptr }
+  }
+}
+
+#[allow(clippy::non_send_fields_in_send_ty)]
+// SAFETY: unsafe trait must have unsafe implementation
+unsafe impl Send for PtrSymbol {}
+// SAFETY: unsafe trait must have unsafe implementation
+unsafe impl Sync for PtrSymbol {}
+
+struct UnsafeCallbackResource {
+  cancel: Rc<CancelHandle>,
+  // Closure is never directly touched, but it keeps the C callback alive
+  // until `close()` method is called.
+  #[allow(dead_code)]
+  closure: libffi::middle::Closure<'static>,
+  info: *mut CallbackInfo,
+}
+
+impl Resource for UnsafeCallbackResource {
+  fn name(&self) -> Cow<str> {
+    "unsafecallback".into()
+  }
+
+  fn close(self: Rc<Self>) {
+    self.cancel.cancel();
+    // SAFETY: This drops the closure and the callback info associated with it.
+    // Any retained function pointers to the closure become dangling pointers.
+    // It is up to the user to know that it is safe to call the `close()` on the
+    // UnsafeCallback instance.
+    unsafe {
+      let info = Box::from_raw(self.info);
+      let isolate = info.isolate.as_mut().unwrap();
+      let _ = v8::Global::from_raw(isolate, info.callback);
+      let _ = v8::Global::from_raw(isolate, info.context);
+    }
+  }
+}
+
+struct CallbackInfo {
+  pub parameters: Vec<NativeType>,
+  pub result: NativeType,
+  pub async_work_sender: mpsc::UnboundedSender<PendingFfiAsyncWork>,
+  pub callback: NonNull<v8::Function>,
+  pub context: NonNull<v8::Context>,
+  pub isolate: *mut v8::Isolate,
+  pub waker: Option<Waker>,
+}
+
+impl Future for CallbackInfo {
+  type Output = ();
+  fn poll(
+    mut self: Pin<&mut Self>,
+    cx: &mut std::task::Context<'_>,
+  ) -> std::task::Poll<Self::Output> {
+    // Always replace the waker to make sure it's bound to the proper Future.
+    self.waker.replace(cx.waker().clone());
+    // The future for the CallbackInfo never resolves: It can only be canceled.
+    Poll::Pending
+  }
+}
+unsafe extern "C" fn deno_ffi_callback(
+  _cif: &libffi::low::ffi_cif,
+  result: &mut c_void,
+  args: *const *const c_void,
+  info: &CallbackInfo,
+) {
+  LOCAL_ISOLATE_POINTER.with(|s| {
+    if ptr::eq(*s.borrow(), info.isolate) {
+      // Own isolate thread, okay to call directly
+      do_ffi_callback(info, result, args);
+    } else {
+      let async_work_sender = &info.async_work_sender;
+      // SAFETY: Safe as this function blocks until `do_ffi_callback` completes and a response message is received.
+      let result: &'static mut c_void = std::mem::transmute(result);
+      let info: &'static CallbackInfo = std::mem::transmute(info);
+      let (response_sender, response_receiver) = sync_channel::<()>(0);
+      let fut = Box::new(move || {
+        do_ffi_callback(info, result, args);
+        response_sender.send(()).unwrap();
+      });
+      async_work_sender.unbounded_send(fut).unwrap();
+      if let Some(waker) = info.waker.as_ref() {
+        // Make sure event loop wakes up to receive our message before we start waiting for a response.
+        waker.wake_by_ref();
+      }
+      response_receiver.recv().unwrap();
+    }
+  });
+}
+
+unsafe fn do_ffi_callback(
+  info: &CallbackInfo,
+  result: &mut c_void,
+  args: *const *const c_void,
+) {
+  let callback: NonNull<v8::Function> = info.callback;
+  let context: NonNull<v8::Context> = info.context;
+  let isolate: *mut v8::Isolate = info.isolate;
+  let isolate = &mut *isolate;
+  let callback = v8::Global::from_raw(isolate, callback);
+  let context = std::mem::transmute::<
+    NonNull<v8::Context>,
+    v8::Local<v8::Context>,
+  >(context);
+  // Call from main thread. If this callback is being triggered due to a
+  // function call coming from Deno itself, then this callback will build
+  // ontop of that stack.
+  // If this callback is being triggered outside of Deno (for example from a
+  // signal handler) then this will either create an empty new stack if
+  // Deno currently has nothing running and is waiting for promises to resolve,
+  // or will (very incorrectly) build ontop of whatever stack exists.
+  // The callback will even be called through from a `while (true)` liveloop, but
+  // it somehow cannot change the values that the loop sees, even if they both
+  // refer the same `let bool_value`.
+  let mut cb_scope = v8::CallbackScope::new(context);
+  let scope = &mut v8::HandleScope::new(&mut cb_scope);
+  let func = callback.open(scope);
+  let result = result as *mut c_void;
+  let vals: &[*const c_void] =
+    std::slice::from_raw_parts(args, info.parameters.len() as usize);
+
+  let mut params: Vec<v8::Local<v8::Value>> = vec![];
+  for (native_type, val) in info.parameters.iter().zip(vals) {
+    let value: v8::Local<v8::Value> = match native_type {
+      NativeType::Bool => {
+        let value = *((*val) as *const bool);
+        v8::Boolean::new(scope, value).into()
+      }
+      NativeType::F32 => {
+        let value = *((*val) as *const f32);
+        v8::Number::new(scope, value as f64).into()
+      }
+      NativeType::F64 => {
+        let value = *((*val) as *const f64);
+        v8::Number::new(scope, value).into()
+      }
+      NativeType::I8 => {
+        let value = *((*val) as *const i8);
+        v8::Integer::new(scope, value as i32).into()
+      }
+      NativeType::U8 => {
+        let value = *((*val) as *const u8);
+        v8::Integer::new_from_unsigned(scope, value as u32).into()
+      }
+      NativeType::I16 => {
+        let value = *((*val) as *const i16);
+        v8::Integer::new(scope, value as i32).into()
+      }
+      NativeType::U16 => {
+        let value = *((*val) as *const u16);
+        v8::Integer::new_from_unsigned(scope, value as u32).into()
+      }
+      NativeType::I32 => {
+        let value = *((*val) as *const i32);
+        v8::Integer::new(scope, value).into()
+      }
+      NativeType::U32 => {
+        let value = *((*val) as *const u32);
+        v8::Integer::new_from_unsigned(scope, value).into()
+      }
+      NativeType::I64 | NativeType::ISize => {
+        let result = *((*val) as *const i64);
+        if result > MAX_SAFE_INTEGER as i64 || result < MIN_SAFE_INTEGER as i64
+        {
+          v8::BigInt::new_from_i64(scope, result).into()
+        } else {
+          v8::Number::new(scope, result as f64).into()
+        }
+      }
+      NativeType::U64 | NativeType::USize => {
+        let result = *((*val) as *const u64);
+        if result > MAX_SAFE_INTEGER as u64 {
+          v8::BigInt::new_from_u64(scope, result).into()
+        } else {
+          v8::Number::new(scope, result as f64).into()
+        }
+      }
+      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
+        let result = *((*val) as *const usize);
+        if result > MAX_SAFE_INTEGER as usize {
+          v8::BigInt::new_from_u64(scope, result as u64).into()
+        } else {
+          v8::Number::new(scope, result as f64).into()
+        }
+      }
+      NativeType::Void => unreachable!(),
+    };
+    params.push(value);
+  }
+
+  let recv = v8::undefined(scope);
+  let call_result = func.call(scope, recv.into(), &params);
+  std::mem::forget(callback);
+
+  if call_result.is_none() {
+    // JS function threw an exception. Set the return value to zero and return.
+    // The exception continue propagating up the call chain when the event loop
+    // resumes.
+    match info.result {
+      NativeType::Bool => {
+        *(result as *mut bool) = false;
+      }
+      NativeType::U32 | NativeType::I32 => {
+        // zero is equal for signed and unsigned alike
+        *(result as *mut u32) = 0;
+      }
+      NativeType::F32 => {
+        *(result as *mut f32) = 0.0;
+      }
+      NativeType::F64 => {
+        *(result as *mut f64) = 0.0;
+      }
+      NativeType::U8 | NativeType::I8 => {
+        // zero is equal for signed and unsigned alike
+        *(result as *mut u8) = 0;
+      }
+      NativeType::U16 | NativeType::I16 => {
+        // zero is equal for signed and unsigned alike
+        *(result as *mut u16) = 0;
+      }
+      NativeType::Pointer
+      | NativeType::Buffer
+      | NativeType::Function
+      | NativeType::U64
+      | NativeType::I64 => {
+        *(result as *mut usize) = 0;
+      }
+      NativeType::Void => {
+        // nop
+      }
+      _ => {
+        unreachable!();
+      }
+    };
+
+    return;
+  }
+  let value = call_result.unwrap();
+
+  match info.result {
+    NativeType::Bool => {
+      let value = if let Ok(value) = v8::Local::<v8::Boolean>::try_from(value) {
+        value.is_true()
+      } else {
+        value.boolean_value(scope)
+      };
+      *(result as *mut bool) = value;
+    }
+    NativeType::I32 => {
+      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as i32
+      } else {
+        // Fallthrough, probably UB.
+        value
+          .int32_value(scope)
+          .expect("Unable to deserialize result parameter.") as i32
+      };
+      *(result as *mut i32) = value;
+    }
+    NativeType::F32 => {
+      let value = if let Ok(value) = v8::Local::<v8::Number>::try_from(value) {
+        value.value() as f32
+      } else {
+        // Fallthrough, probably UB.
+        value
+          .number_value(scope)
+          .expect("Unable to deserialize result parameter.") as f32
+      };
+      *(result as *mut f32) = value;
+    }
+    NativeType::F64 => {
+      let value = if let Ok(value) = v8::Local::<v8::Number>::try_from(value) {
+        value.value()
+      } else {
+        // Fallthrough, probably UB.
+        value
+          .number_value(scope)
+          .expect("Unable to deserialize result parameter.")
+      };
+      *(result as *mut f64) = value;
+    }
+    NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
+      let pointer = if let Ok(value) =
+        v8::Local::<v8::ArrayBufferView>::try_from(value)
+      {
+        let byte_offset = value.byte_offset();
+        let backing_store = value
+          .buffer(scope)
+          .expect("Unable to deserialize result parameter.")
+          .get_backing_store();
+        &backing_store[byte_offset..] as *const _ as *const u8
+      } else if let Ok(value) = v8::Local::<v8::BigInt>::try_from(value) {
+        value.u64_value().0 as usize as *const u8
+      } else if let Ok(value) = v8::Local::<v8::ArrayBuffer>::try_from(value) {
+        let backing_store = value.get_backing_store();
+        &backing_store[..] as *const _ as *const u8
+      } else if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as usize as *const u8
+      } else if value.is_null() {
+        ptr::null()
+      } else {
+        // Fallthrough: Probably someone returned a number but this could
+        // also be eg. a string. This is essentially UB.
+        value
+          .integer_value(scope)
+          .expect("Unable to deserialize result parameter.") as usize
+          as *const u8
+      };
+      *(result as *mut *const u8) = pointer;
+    }
+    NativeType::I8 => {
+      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as i8
+      } else {
+        // Fallthrough, essentially UB.
+        value
+          .int32_value(scope)
+          .expect("Unable to deserialize result parameter.") as i8
+      };
+      *(result as *mut i8) = value;
+    }
+    NativeType::U8 => {
+      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as u8
+      } else {
+        // Fallthrough, essentially UB.
+        value
+          .uint32_value(scope)
+          .expect("Unable to deserialize result parameter.") as u8
+      };
+      *(result as *mut u8) = value;
+    }
+    NativeType::I16 => {
+      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as i16
+      } else {
+        // Fallthrough, essentially UB.
+        value
+          .int32_value(scope)
+          .expect("Unable to deserialize result parameter.") as i16
+      };
+      *(result as *mut i16) = value;
+    }
+    NativeType::U16 => {
+      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as u16
+      } else {
+        // Fallthrough, essentially UB.
+        value
+          .uint32_value(scope)
+          .expect("Unable to deserialize result parameter.") as u16
+      };
+      *(result as *mut u16) = value;
+    }
+    NativeType::U32 => {
+      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        value.value() as u32
+      } else {
+        // Fallthrough, essentially UB.
+        value
+          .uint32_value(scope)
+          .expect("Unable to deserialize result parameter.")
+      };
+      *(result as *mut u32) = value;
+    }
+    NativeType::I64 => {
+      if let Ok(value) = v8::Local::<v8::BigInt>::try_from(value) {
+        *(result as *mut i64) = value.i64_value().0;
+      } else if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        *(result as *mut i64) = value.value();
+      } else {
+        *(result as *mut i64) = value
+          .integer_value(scope)
+          .expect("Unable to deserialize result parameter.")
+          as i64;
+      }
+    }
+    NativeType::U64 => {
+      if let Ok(value) = v8::Local::<v8::BigInt>::try_from(value) {
+        *(result as *mut u64) = value.u64_value().0;
+      } else if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
+        *(result as *mut u64) = value.value() as u64;
+      } else {
+        *(result as *mut u64) = value
+          .integer_value(scope)
+          .expect("Unable to deserialize result parameter.")
+          as u64;
+      }
+    }
+    NativeType::Void => {
+      // nop
+    }
+    _ => {
+      unreachable!();
+    }
+  };
+}
+
+#[op]
+pub fn op_ffi_unsafe_callback_ref(
+  state: Rc<RefCell<OpState>>,
+  rid: ResourceId,
+) -> Result<impl Future<Output = Result<(), AnyError>>, AnyError> {
+  let state = state.borrow();
+  let callback_resource =
+    state.resource_table.get::<UnsafeCallbackResource>(rid)?;
+
+  Ok(async move {
+    let info: &mut CallbackInfo =
+    // SAFETY: CallbackInfo pointer stays valid as long as the resource is still alive.
+      unsafe { callback_resource.info.as_mut().unwrap() };
+    // Ignore cancellation rejection
+    let _ = info
+      .into_future()
+      .or_cancel(callback_resource.cancel.clone())
+      .await;
+    Ok(())
+  })
+}
+
+#[op(fast)]
+pub fn op_ffi_unsafe_callback_unref(
+  state: &mut deno_core::OpState,
+  rid: u32,
+) -> Result<(), AnyError> {
+  state
+    .resource_table
+    .get::<UnsafeCallbackResource>(rid)?
+    .cancel
+    .cancel();
+  Ok(())
+}
+
+#[derive(Deserialize)]
+pub struct RegisterCallbackArgs {
+  parameters: Vec<NativeType>,
+  result: NativeType,
+}
+
+#[op(v8)]
+pub fn op_ffi_unsafe_callback_create<FP, 'scope>(
+  state: &mut deno_core::OpState,
+  scope: &mut v8::HandleScope<'scope>,
+  args: RegisterCallbackArgs,
+  cb: serde_v8::Value<'scope>,
+) -> Result<serde_v8::Value<'scope>, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafeCallback");
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let v8_value = cb.v8_value;
+  let cb = v8::Local::<v8::Function>::try_from(v8_value)?;
+
+  let isolate: *mut v8::Isolate = &mut *scope as &mut v8::Isolate;
+  LOCAL_ISOLATE_POINTER.with(|s| {
+    if s.borrow().is_null() {
+      s.replace(isolate);
+    }
+  });
+
+  let async_work_sender =
+    state.borrow_mut::<FfiState>().async_work_sender.clone();
+  let callback = v8::Global::new(scope, cb).into_raw();
+  let current_context = scope.get_current_context();
+  let context = v8::Global::new(scope, current_context).into_raw();
+
+  let info: *mut CallbackInfo = Box::leak(Box::new(CallbackInfo {
+    parameters: args.parameters.clone(),
+    result: args.result,
+    async_work_sender,
+    callback,
+    context,
+    isolate,
+    waker: None,
+  }));
+  let cif = Cif::new(
+    args.parameters.into_iter().map(libffi::middle::Type::from),
+    libffi::middle::Type::from(args.result),
+  );
+
+  // SAFETY: CallbackInfo is leaked, is not null and stays valid as long as the callback exists.
+  let closure = libffi::middle::Closure::new(cif, deno_ffi_callback, unsafe {
+    info.as_ref().unwrap()
+  });
+  let ptr = *closure.code_ptr() as usize;
+  let resource = UnsafeCallbackResource {
+    cancel: CancelHandle::new_rc(),
+    closure,
+    info,
+  };
+  let rid = state.resource_table.add(resource);
+
+  let rid_local = v8::Integer::new_from_unsigned(scope, rid);
+  let ptr_local: v8::Local<v8::Value> = if ptr > MAX_SAFE_INTEGER as usize {
+    v8::BigInt::new_from_u64(scope, ptr as u64).into()
+  } else {
+    v8::Number::new(scope, ptr as f64).into()
+  };
+  let array = v8::Array::new(scope, 2);
+  array.set_index(scope, 0, rid_local.into());
+  array.set_index(scope, 1, ptr_local);
+  let array_value: v8::Local<v8::Value> = array.into();
+
+  Ok(array_value.into())
+}

ext/ffi/dlfcn.rs

@@ -0,0 +1,398 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::check_unstable;
+use crate::symbol::NativeType;
+use crate::symbol::Symbol;
+use crate::turbocall;
+use crate::FfiPermissions;
+use deno_core::error::generic_error;
+use deno_core::error::AnyError;
+use deno_core::op;
+use deno_core::serde_v8;
+use deno_core::v8;
+use deno_core::Resource;
+use deno_core::ResourceId;
+use dlopen::raw::Library;
+use serde::Deserialize;
+use std::borrow::Cow;
+use std::collections::HashMap;
+use std::ffi::c_void;
+use std::path::PathBuf;
+use std::rc::Rc;
+
+pub struct DynamicLibraryResource {
+  lib: Library,
+  pub symbols: HashMap<String, Box<Symbol>>,
+}
+
+impl Resource for DynamicLibraryResource {
+  fn name(&self) -> Cow<str> {
+    "dynamicLibrary".into()
+  }
+
+  fn close(self: Rc<Self>) {
+    drop(self)
+  }
+}
+
+impl DynamicLibraryResource {
+  pub fn get_static(&self, symbol: String) -> Result<*const c_void, AnyError> {
+    // By default, Err returned by this function does not tell
+    // which symbol wasn't exported. So we'll modify the error
+    // message to include the name of symbol.
+    //
+    // SAFETY: The obtained T symbol is the size of a pointer.
+    match unsafe { self.lib.symbol::<*const c_void>(&symbol) } {
+      Ok(value) => Ok(Ok(value)),
+      Err(err) => Err(generic_error(format!(
+        "Failed to register symbol {}: {}",
+        symbol, err
+      ))),
+    }?
+  }
+}
+
+pub fn needs_unwrap(rv: NativeType) -> bool {
+  matches!(
+    rv,
+    NativeType::Function
+      | NativeType::Pointer
+      | NativeType::Buffer
+      | NativeType::I64
+      | NativeType::ISize
+      | NativeType::U64
+      | NativeType::USize
+  )
+}
+
+fn is_i64(rv: NativeType) -> bool {
+  matches!(rv, NativeType::I64 | NativeType::ISize)
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct ForeignFunction {
+  name: Option<String>,
+  pub parameters: Vec<NativeType>,
+  pub result: NativeType,
+  #[serde(rename = "nonblocking")]
+  non_blocking: Option<bool>,
+  #[serde(rename = "callback")]
+  #[serde(default = "default_callback")]
+  callback: bool,
+}
+
+fn default_callback() -> bool {
+  false
+}
+
+// ForeignStatic's name and type fields are read and used by
+// serde_v8 to determine which variant a ForeignSymbol is.
+// They are not used beyond that and are thus marked with underscores.
+#[derive(Deserialize, Debug)]
+struct ForeignStatic {
+  #[serde(rename(deserialize = "name"))]
+  _name: Option<String>,
+  #[serde(rename(deserialize = "type"))]
+  _type: String,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(untagged)]
+enum ForeignSymbol {
+  ForeignFunction(ForeignFunction),
+  ForeignStatic(ForeignStatic),
+}
+
+#[derive(Deserialize, Debug)]
+pub struct FfiLoadArgs {
+  path: String,
+  symbols: HashMap<String, ForeignSymbol>,
+}
+
+#[op(v8)]
+pub fn op_ffi_load<FP, 'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: &mut deno_core::OpState,
+  args: FfiLoadArgs,
+) -> Result<(ResourceId, serde_v8::Value<'scope>), AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  let path = args.path;
+
+  check_unstable(state, "Deno.dlopen");
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(Some(&PathBuf::from(&path)))?;
+
+  let lib = Library::open(&path).map_err(|e| {
+    dlopen::Error::OpeningLibraryError(std::io::Error::new(
+      std::io::ErrorKind::Other,
+      format_error(e, path),
+    ))
+  })?;
+  let mut resource = DynamicLibraryResource {
+    lib,
+    symbols: HashMap::new(),
+  };
+  let obj = v8::Object::new(scope);
+
+  for (symbol_key, foreign_symbol) in args.symbols {
+    match foreign_symbol {
+      ForeignSymbol::ForeignStatic(_) => {
+        // No-op: Statics will be handled separately and are not part of the Rust-side resource.
+      }
+      ForeignSymbol::ForeignFunction(foreign_fn) => {
+        let symbol = match &foreign_fn.name {
+          Some(symbol) => symbol,
+          None => &symbol_key,
+        };
+        // By default, Err returned by this function does not tell
+        // which symbol wasn't exported. So we'll modify the error
+        // message to include the name of symbol.
+        let fn_ptr =
+          // SAFETY: The obtained T symbol is the size of a pointer.
+          match unsafe { resource.lib.symbol::<*const c_void>(symbol) } {
+            Ok(value) => Ok(value),
+            Err(err) => Err(generic_error(format!(
+              "Failed to register symbol {}: {}",
+              symbol, err
+            ))),
+          }?;
+        let ptr = libffi::middle::CodePtr::from_ptr(fn_ptr as _);
+        let cif = libffi::middle::Cif::new(
+          foreign_fn
+            .parameters
+            .clone()
+            .into_iter()
+            .map(libffi::middle::Type::from),
+          foreign_fn.result.into(),
+        );
+
+        let func_key = v8::String::new(scope, &symbol_key).unwrap();
+        let sym = Box::new(Symbol {
+          cif,
+          ptr,
+          parameter_types: foreign_fn.parameters,
+          result_type: foreign_fn.result,
+          can_callback: foreign_fn.callback,
+        });
+
+        resource.symbols.insert(symbol_key, sym.clone());
+        match foreign_fn.non_blocking {
+          // Generate functions for synchronous calls.
+          Some(false) | None => {
+            let function = make_sync_fn(scope, sym);
+            obj.set(scope, func_key.into(), function.into());
+          }
+          // This optimization is not yet supported for non-blocking calls.
+          _ => {}
+        };
+      }
+    }
+  }
+
+  let rid = state.resource_table.add(resource);
+  Ok((
+    rid,
+    serde_v8::Value {
+      v8_value: obj.into(),
+    },
+  ))
+}
+
+// Create a JavaScript function for synchronous FFI call to
+// the given symbol.
+fn make_sync_fn<'s>(
+  scope: &mut v8::HandleScope<'s>,
+  sym: Box<Symbol>,
+) -> v8::Local<'s, v8::Function> {
+  let sym = Box::leak(sym);
+  let builder = v8::FunctionTemplate::builder(
+    |scope: &mut v8::HandleScope,
+     args: v8::FunctionCallbackArguments,
+     mut rv: v8::ReturnValue| {
+      let external: v8::Local<v8::External> = args.data().try_into().unwrap();
+      // SAFETY: The pointer will not be deallocated until the function is
+      // garbage collected.
+      let symbol = unsafe { &*(external.value() as *const Symbol) };
+      let needs_unwrap = match needs_unwrap(symbol.result_type) {
+        true => Some(args.get(symbol.parameter_types.len() as i32)),
+        false => None,
+      };
+      match crate::call::ffi_call_sync(scope, args, symbol) {
+        Ok(result) => {
+          match needs_unwrap {
+            Some(v) => {
+              let view: v8::Local<v8::ArrayBufferView> = v.try_into().unwrap();
+              let backing_store =
+                view.buffer(scope).unwrap().get_backing_store();
+
+              if is_i64(symbol.result_type) {
+                // SAFETY: v8::SharedRef<v8::BackingStore> is similar to Arc<[u8]>,
+                // it points to a fixed continuous slice of bytes on the heap.
+                let bs = unsafe {
+                  &mut *(&backing_store[..] as *const _ as *mut [u8]
+                    as *mut i64)
+                };
+                // SAFETY: We already checked that type == I64
+                let value = unsafe { result.i64_value };
+                *bs = value;
+              } else {
+                // SAFETY: v8::SharedRef<v8::BackingStore> is similar to Arc<[u8]>,
+                // it points to a fixed continuous slice of bytes on the heap.
+                let bs = unsafe {
+                  &mut *(&backing_store[..] as *const _ as *mut [u8]
+                    as *mut u64)
+                };
+                // SAFETY: We checked that type == U64
+                let value = unsafe { result.u64_value };
+                *bs = value;
+              }
+            }
+            None => {
+              // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
+              let result = unsafe { result.to_v8(scope, symbol.result_type) };
+              rv.set(result.v8_value);
+            }
+          }
+        }
+        Err(err) => {
+          deno_core::_ops::throw_type_error(scope, err.to_string());
+        }
+      };
+    },
+  )
+  .data(v8::External::new(scope, sym as *mut Symbol as *mut _).into());
+
+  let mut fast_call_alloc = None;
+
+  let func = if turbocall::is_compatible(sym) {
+    let trampoline = turbocall::compile_trampoline(sym);
+    let func = builder.build_fast(
+      scope,
+      &turbocall::make_template(sym, &trampoline),
+      None,
+    );
+    fast_call_alloc = Some(Box::into_raw(Box::new(trampoline)));
+    func
+  } else {
+    builder.build(scope)
+  };
+  let func = func.get_function(scope).unwrap();
+
+  let weak = v8::Weak::with_finalizer(
+    scope,
+    func,
+    Box::new(move |_| {
+      // SAFETY: This is never called twice. pointer obtained
+      // from Box::into_raw, hence, satisfies memory layout requirements.
+      let _ = unsafe { Box::from_raw(sym) };
+      if let Some(fast_call_ptr) = fast_call_alloc {
+        // fast-call compiled trampoline is unmapped when the MMAP handle is dropped
+        // SAFETY: This is never called twice. pointer obtained
+        // from Box::into_raw, hence, satisfies memory layout requirements.
+        let _ = unsafe { Box::from_raw(fast_call_ptr) };
+      }
+    }),
+  );
+
+  weak.to_local(scope).unwrap()
+}
+
+// `path` is only used on Windows.
+#[allow(unused_variables)]
+pub(crate) fn format_error(e: dlopen::Error, path: String) -> String {
+  match e {
+    #[cfg(target_os = "windows")]
+    // This calls FormatMessageW with library path
+    // as replacement for the insert sequences.
+    // Unlike libstd which passes the FORMAT_MESSAGE_IGNORE_INSERTS
+    // flag without any arguments.
+    //
+    // https://github.com/denoland/deno/issues/11632
+    dlopen::Error::OpeningLibraryError(e) => {
+      use std::ffi::OsStr;
+      use std::os::windows::ffi::OsStrExt;
+      use winapi::shared::minwindef::DWORD;
+      use winapi::shared::winerror::ERROR_INSUFFICIENT_BUFFER;
+      use winapi::um::errhandlingapi::GetLastError;
+      use winapi::um::winbase::FormatMessageW;
+      use winapi::um::winbase::FORMAT_MESSAGE_ARGUMENT_ARRAY;
+      use winapi::um::winbase::FORMAT_MESSAGE_FROM_SYSTEM;
+      use winapi::um::winnt::LANG_SYSTEM_DEFAULT;
+      use winapi::um::winnt::MAKELANGID;
+      use winapi::um::winnt::SUBLANG_SYS_DEFAULT;
+
+      let err_num = match e.raw_os_error() {
+        Some(err_num) => err_num,
+        // This should never hit unless dlopen changes its error type.
+        None => return e.to_string(),
+      };
+
+      // Language ID (0x0800)
+      let lang_id =
+        MAKELANGID(LANG_SYSTEM_DEFAULT, SUBLANG_SYS_DEFAULT) as DWORD;
+
+      let mut buf = vec![0; 500];
+
+      let path = OsStr::new(&path)
+        .encode_wide()
+        .chain(Some(0).into_iter())
+        .collect::<Vec<_>>();
+
+      let arguments = [path.as_ptr()];
+
+      loop {
+        // SAFETY:
+        // winapi call to format the error message
+        let length = unsafe {
+          FormatMessageW(
+            FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY,
+            std::ptr::null_mut(),
+            err_num as DWORD,
+            lang_id as DWORD,
+            buf.as_mut_ptr(),
+            buf.len() as DWORD,
+            arguments.as_ptr() as _,
+          )
+        };
+
+        if length == 0 {
+          // SAFETY:
+          // winapi call to get the last error message
+          let err_num = unsafe { GetLastError() };
+          if err_num == ERROR_INSUFFICIENT_BUFFER {
+            buf.resize(buf.len() * 2, 0);
+            continue;
+          }
+
+          // Something went wrong, just return the original error.
+          return e.to_string();
+        }
+
+        let msg = String::from_utf16_lossy(&buf[..length as usize]);
+        return msg;
+      }
+    }
+    _ => e.to_string(),
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  #[cfg(target_os = "windows")]
+  #[test]
+  fn test_format_error() {
+    use super::format_error;
+
+    // BAD_EXE_FORMAT
+    let err = dlopen::Error::OpeningLibraryError(
+      std::io::Error::from_raw_os_error(0x000000C1),
+    );
+    assert_eq!(
+      format_error(err, "foo.dll".to_string()),
+      "foo.dll is not a valid Win32 application.\r\n".to_string(),
+    );
+  }
+}

ext/ffi/ir.rs

@@ -0,0 +1,527 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::symbol::NativeType;
+use crate::MAX_SAFE_INTEGER;
+use crate::MIN_SAFE_INTEGER;
+use deno_core::error::type_error;
+use deno_core::error::AnyError;
+use deno_core::serde_json::Value;
+use deno_core::serde_v8;
+use deno_core::v8;
+use libffi::middle::Arg;
+use std::ffi::c_void;
+use std::ptr;
+
+/// Intermediate format for easy translation from NativeType + V8 value
+/// to libffi argument types.
+#[repr(C)]
+pub union NativeValue {
+  pub void_value: (),
+  pub bool_value: bool,
+  pub u8_value: u8,
+  pub i8_value: i8,
+  pub u16_value: u16,
+  pub i16_value: i16,
+  pub u32_value: u32,
+  pub i32_value: i32,
+  pub u64_value: u64,
+  pub i64_value: i64,
+  pub usize_value: usize,
+  pub isize_value: isize,
+  pub f32_value: f32,
+  pub f64_value: f64,
+  pub pointer: *mut c_void,
+}
+
+impl NativeValue {
+  pub unsafe fn as_arg(&self, native_type: NativeType) -> Arg {
+    match native_type {
+      NativeType::Void => unreachable!(),
+      NativeType::Bool => Arg::new(&self.bool_value),
+      NativeType::U8 => Arg::new(&self.u8_value),
+      NativeType::I8 => Arg::new(&self.i8_value),
+      NativeType::U16 => Arg::new(&self.u16_value),
+      NativeType::I16 => Arg::new(&self.i16_value),
+      NativeType::U32 => Arg::new(&self.u32_value),
+      NativeType::I32 => Arg::new(&self.i32_value),
+      NativeType::U64 => Arg::new(&self.u64_value),
+      NativeType::I64 => Arg::new(&self.i64_value),
+      NativeType::USize => Arg::new(&self.usize_value),
+      NativeType::ISize => Arg::new(&self.isize_value),
+      NativeType::F32 => Arg::new(&self.f32_value),
+      NativeType::F64 => Arg::new(&self.f64_value),
+      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
+        Arg::new(&self.pointer)
+      }
+    }
+  }
+
+  // SAFETY: native_type must correspond to the type of value represented by the union field
+  pub unsafe fn to_value(&self, native_type: NativeType) -> Value {
+    match native_type {
+      NativeType::Void => Value::Null,
+      NativeType::Bool => Value::from(self.bool_value),
+      NativeType::U8 => Value::from(self.u8_value),
+      NativeType::I8 => Value::from(self.i8_value),
+      NativeType::U16 => Value::from(self.u16_value),
+      NativeType::I16 => Value::from(self.i16_value),
+      NativeType::U32 => Value::from(self.u32_value),
+      NativeType::I32 => Value::from(self.i32_value),
+      NativeType::U64 => Value::from(self.u64_value),
+      NativeType::I64 => Value::from(self.i64_value),
+      NativeType::USize => Value::from(self.usize_value),
+      NativeType::ISize => Value::from(self.isize_value),
+      NativeType::F32 => Value::from(self.f32_value),
+      NativeType::F64 => Value::from(self.f64_value),
+      NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
+        Value::from(self.pointer as usize)
+      }
+    }
+  }
+
+  // SAFETY: native_type must correspond to the type of value represented by the union field
+  #[inline]
+  pub unsafe fn to_v8<'scope>(
+    &self,
+    scope: &mut v8::HandleScope<'scope>,
+    native_type: NativeType,
+  ) -> serde_v8::Value<'scope> {
+    match native_type {
+      NativeType::Void => {
+        let local_value: v8::Local<v8::Value> = v8::undefined(scope).into();
+        local_value.into()
+      }
+      NativeType::Bool => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Boolean::new(scope, self.bool_value).into();
+        local_value.into()
+      }
+      NativeType::U8 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Integer::new_from_unsigned(scope, self.u8_value as u32).into();
+        local_value.into()
+      }
+      NativeType::I8 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Integer::new(scope, self.i8_value as i32).into();
+        local_value.into()
+      }
+      NativeType::U16 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Integer::new_from_unsigned(scope, self.u16_value as u32).into();
+        local_value.into()
+      }
+      NativeType::I16 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Integer::new(scope, self.i16_value as i32).into();
+        local_value.into()
+      }
+      NativeType::U32 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Integer::new_from_unsigned(scope, self.u32_value).into();
+        local_value.into()
+      }
+      NativeType::I32 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Integer::new(scope, self.i32_value).into();
+        local_value.into()
+      }
+      NativeType::U64 => {
+        let value = self.u64_value;
+        let local_value: v8::Local<v8::Value> =
+          if value > MAX_SAFE_INTEGER as u64 {
+            v8::BigInt::new_from_u64(scope, value).into()
+          } else {
+            v8::Number::new(scope, value as f64).into()
+          };
+        local_value.into()
+      }
+      NativeType::I64 => {
+        let value = self.i64_value;
+        let local_value: v8::Local<v8::Value> =
+          if value > MAX_SAFE_INTEGER as i64 || value < MIN_SAFE_INTEGER as i64
+          {
+            v8::BigInt::new_from_i64(scope, self.i64_value).into()
+          } else {
+            v8::Number::new(scope, value as f64).into()
+          };
+        local_value.into()
+      }
+      NativeType::USize => {
+        let value = self.usize_value;
+        let local_value: v8::Local<v8::Value> =
+          if value > MAX_SAFE_INTEGER as usize {
+            v8::BigInt::new_from_u64(scope, value as u64).into()
+          } else {
+            v8::Number::new(scope, value as f64).into()
+          };
+        local_value.into()
+      }
+      NativeType::ISize => {
+        let value = self.isize_value;
+        let local_value: v8::Local<v8::Value> =
+          if !(MIN_SAFE_INTEGER..=MAX_SAFE_INTEGER).contains(&value) {
+            v8::BigInt::new_from_i64(scope, self.isize_value as i64).into()
+          } else {
+            v8::Number::new(scope, value as f64).into()
+          };
+        local_value.into()
+      }
+      NativeType::F32 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Number::new(scope, self.f32_value as f64).into();
+        local_value.into()
+      }
+      NativeType::F64 => {
+        let local_value: v8::Local<v8::Value> =
+          v8::Number::new(scope, self.f64_value).into();
+        local_value.into()
+      }
+      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
+        let value = self.pointer as u64;
+        let local_value: v8::Local<v8::Value> =
+          if value > MAX_SAFE_INTEGER as u64 {
+            v8::BigInt::new_from_u64(scope, value).into()
+          } else {
+            v8::Number::new(scope, value as f64).into()
+          };
+        local_value.into()
+      }
+    }
+  }
+}
+
+// SAFETY: unsafe trait must have unsafe implementation
+unsafe impl Send for NativeValue {}
+
+#[inline]
+pub fn ffi_parse_bool_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let bool_value = v8::Local::<v8::Boolean>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI u8 type, expected boolean"))?
+    .is_true();
+  Ok(NativeValue { bool_value })
+}
+
+#[inline]
+pub fn ffi_parse_u8_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let u8_value = v8::Local::<v8::Uint32>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI u8 type, expected unsigned integer"))?
+    .value() as u8;
+  Ok(NativeValue { u8_value })
+}
+
+#[inline]
+pub fn ffi_parse_i8_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let i8_value = v8::Local::<v8::Int32>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI i8 type, expected integer"))?
+    .value() as i8;
+  Ok(NativeValue { i8_value })
+}
+
+#[inline]
+pub fn ffi_parse_u16_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let u16_value = v8::Local::<v8::Uint32>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI u16 type, expected unsigned integer"))?
+    .value() as u16;
+  Ok(NativeValue { u16_value })
+}
+
+#[inline]
+pub fn ffi_parse_i16_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let i16_value = v8::Local::<v8::Int32>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI i16 type, expected integer"))?
+    .value() as i16;
+  Ok(NativeValue { i16_value })
+}
+
+#[inline]
+pub fn ffi_parse_u32_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let u32_value = v8::Local::<v8::Uint32>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI u32 type, expected unsigned integer"))?
+    .value() as u32;
+  Ok(NativeValue { u32_value })
+}
+
+#[inline]
+pub fn ffi_parse_i32_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let i32_value = v8::Local::<v8::Int32>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI i32 type, expected integer"))?
+    .value() as i32;
+  Ok(NativeValue { i32_value })
+}
+
+#[inline]
+pub fn ffi_parse_u64_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
+  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
+  let u64_value: u64 = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg)
+  {
+    value.u64_value().0
+  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
+    value.integer_value(scope).unwrap() as u64
+  } else {
+    return Err(type_error(
+      "Invalid FFI u64 type, expected unsigned integer",
+    ));
+  };
+  Ok(NativeValue { u64_value })
+}
+
+#[inline]
+pub fn ffi_parse_i64_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
+  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
+  let i64_value: i64 = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg)
+  {
+    value.i64_value().0
+  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
+    value.integer_value(scope).unwrap() as i64
+  } else {
+    return Err(type_error("Invalid FFI i64 type, expected integer"));
+  };
+  Ok(NativeValue { i64_value })
+}
+
+#[inline]
+pub fn ffi_parse_usize_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
+  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
+  let usize_value: usize =
+    if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
+      value.u64_value().0 as usize
+    } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
+      value.integer_value(scope).unwrap() as usize
+    } else {
+      return Err(type_error("Invalid FFI usize type, expected integer"));
+    };
+  Ok(NativeValue { usize_value })
+}
+
+#[inline]
+pub fn ffi_parse_isize_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
+  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
+  let isize_value: isize =
+    if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
+      value.i64_value().0 as isize
+    } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
+      value.integer_value(scope).unwrap() as isize
+    } else {
+      return Err(type_error("Invalid FFI isize type, expected integer"));
+    };
+  Ok(NativeValue { isize_value })
+}
+
+#[inline]
+pub fn ffi_parse_f32_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let f32_value = v8::Local::<v8::Number>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI f32 type, expected number"))?
+    .value() as f32;
+  Ok(NativeValue { f32_value })
+}
+
+#[inline]
+pub fn ffi_parse_f64_arg(
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  let f64_value = v8::Local::<v8::Number>::try_from(arg)
+    .map_err(|_| type_error("Invalid FFI f64 type, expected number"))?
+    .value() as f64;
+  Ok(NativeValue { f64_value })
+}
+
+#[inline]
+pub fn ffi_parse_pointer_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. BigInt: Uncommon and not supported by Fast API, optimise this case.
+  // 2. Number: Common and supported by Fast API.
+  // 3. Null: Very uncommon / can be represented by a 0.
+  let pointer = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
+    value.u64_value().0 as usize as *mut c_void
+  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
+    value.integer_value(scope).unwrap() as usize as *mut c_void
+  } else if arg.is_null() {
+    ptr::null_mut()
+  } else {
+    return Err(type_error(
+      "Invalid FFI pointer type, expected null, integer or BigInt",
+    ));
+  };
+  Ok(NativeValue { pointer })
+}
+
+#[inline]
+pub fn ffi_parse_buffer_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. ArrayBuffer: Fairly common and not supported by Fast API, optimise this case.
+  // 2. ArrayBufferView: Common and supported by Fast API
+  // 5. Null: Very uncommon / can be represented by a 0.
+
+  let pointer = if let Ok(value) = v8::Local::<v8::ArrayBuffer>::try_from(arg) {
+    if let Some(non_null) = value.data() {
+      non_null.as_ptr()
+    } else {
+      ptr::null_mut()
+    }
+  } else if let Ok(value) = v8::Local::<v8::ArrayBufferView>::try_from(arg) {
+    let byte_offset = value.byte_offset();
+    let pointer = value
+      .buffer(scope)
+      .ok_or_else(|| {
+        type_error("Invalid FFI ArrayBufferView, expected data in the buffer")
+      })?
+      .data();
+    if let Some(non_null) = pointer {
+      // SAFETY: Pointer is non-null, and V8 guarantees that the byte_offset
+      // is within the buffer backing store.
+      unsafe { non_null.as_ptr().add(byte_offset) }
+    } else {
+      ptr::null_mut()
+    }
+  } else if arg.is_null() {
+    ptr::null_mut()
+  } else {
+    return Err(type_error(
+      "Invalid FFI buffer type, expected null, ArrayBuffer, or ArrayBufferView",
+    ));
+  };
+  Ok(NativeValue { pointer })
+}
+
+#[inline]
+pub fn ffi_parse_function_arg(
+  scope: &mut v8::HandleScope,
+  arg: v8::Local<v8::Value>,
+) -> Result<NativeValue, AnyError> {
+  // Order of checking:
+  // 1. BigInt: Uncommon and not supported by Fast API, optimise this case.
+  // 2. Number: Common and supported by Fast API, optimise this case as second.
+  // 3. Null: Very uncommon / can be represented by a 0.
+  let pointer = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
+    value.u64_value().0 as usize as *mut c_void
+  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
+    value.integer_value(scope).unwrap() as usize as *mut c_void
+  } else if arg.is_null() {
+    ptr::null_mut()
+  } else {
+    return Err(type_error(
+      "Invalid FFI function type, expected null, integer, or BigInt",
+    ));
+  };
+  Ok(NativeValue { pointer })
+}
+
+pub fn ffi_parse_args<'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  args: serde_v8::Value<'scope>,
+  parameter_types: &[NativeType],
+) -> Result<Vec<NativeValue>, AnyError>
+where
+  'scope: 'scope,
+{
+  if parameter_types.is_empty() {
+    return Ok(vec![]);
+  }
+
+  let args = v8::Local::<v8::Array>::try_from(args.v8_value)
+    .map_err(|_| type_error("Invalid FFI parameters, expected Array"))?;
+  let mut ffi_args: Vec<NativeValue> =
+    Vec::with_capacity(parameter_types.len());
+
+  for (index, native_type) in parameter_types.iter().enumerate() {
+    let value = args.get_index(scope, index as u32).unwrap();
+    match native_type {
+      NativeType::Bool => {
+        ffi_args.push(ffi_parse_bool_arg(value)?);
+      }
+      NativeType::U8 => {
+        ffi_args.push(ffi_parse_u8_arg(value)?);
+      }
+      NativeType::I8 => {
+        ffi_args.push(ffi_parse_i8_arg(value)?);
+      }
+      NativeType::U16 => {
+        ffi_args.push(ffi_parse_u16_arg(value)?);
+      }
+      NativeType::I16 => {
+        ffi_args.push(ffi_parse_i16_arg(value)?);
+      }
+      NativeType::U32 => {
+        ffi_args.push(ffi_parse_u32_arg(value)?);
+      }
+      NativeType::I32 => {
+        ffi_args.push(ffi_parse_i32_arg(value)?);
+      }
+      NativeType::U64 => {
+        ffi_args.push(ffi_parse_u64_arg(scope, value)?);
+      }
+      NativeType::I64 => {
+        ffi_args.push(ffi_parse_i64_arg(scope, value)?);
+      }
+      NativeType::USize => {
+        ffi_args.push(ffi_parse_usize_arg(scope, value)?);
+      }
+      NativeType::ISize => {
+        ffi_args.push(ffi_parse_isize_arg(scope, value)?);
+      }
+      NativeType::F32 => {
+        ffi_args.push(ffi_parse_f32_arg(value)?);
+      }
+      NativeType::F64 => {
+        ffi_args.push(ffi_parse_f64_arg(value)?);
+      }
+      NativeType::Buffer => {
+        ffi_args.push(ffi_parse_buffer_arg(scope, value)?);
+      }
+      NativeType::Pointer => {
+        ffi_args.push(ffi_parse_pointer_arg(scope, value)?);
+      }
+      NativeType::Function => {
+        ffi_args.push(ffi_parse_function_arg(scope, value)?);
+      }
+      NativeType::Void => {
+        unreachable!();
+      }
+    }
+  }
+
+  Ok(ffi_args)
+}

ext/ffi/repr.rs

@@ -0,0 +1,454 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::check_unstable;
+use crate::FfiPermissions;
+use deno_core::error::range_error;
+use deno_core::error::type_error;
+use deno_core::error::AnyError;
+use deno_core::op;
+use deno_core::serde_v8;
+use deno_core::v8;
+use std::ffi::c_char;
+use std::ffi::c_void;
+use std::ffi::CStr;
+use std::ptr;
+
+#[op(fast)]
+pub fn op_ffi_ptr_of<FP>(
+  state: &mut deno_core::OpState,
+  buf: *const u8,
+  out: &mut [u32],
+) -> Result<(), AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointer#of");
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let outptr = out.as_ptr() as *mut usize;
+  let length = out.len();
+  assert!(
+    length >= (std::mem::size_of::<usize>() / std::mem::size_of::<u32>())
+  );
+  assert_eq!(outptr as usize % std::mem::size_of::<usize>(), 0);
+
+  // SAFETY: Out buffer was asserted to be at least large enough to hold a usize, and properly aligned.
+  let out = unsafe { &mut *outptr };
+  *out = buf as usize;
+
+  Ok(())
+}
+
+unsafe extern "C" fn noop_deleter_callback(
+  _data: *mut c_void,
+  _byte_length: usize,
+  _deleter_data: *mut c_void,
+) {
+}
+
+#[op(v8)]
+pub fn op_ffi_get_buf<FP, 'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+  len: usize,
+) -> Result<serde_v8::Value<'scope>, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#arrayBuffer");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *mut c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid FFI pointer value, got nullptr"));
+  }
+
+  // SAFETY: Offset is user defined.
+  let ptr = unsafe { ptr.add(offset) };
+
+  // SAFETY: Trust the user to have provided a real pointer, and a valid matching size to it. Since this is a foreign pointer, we should not do any deletion.
+  let backing_store = unsafe {
+    v8::ArrayBuffer::new_backing_store_from_ptr(
+      ptr,
+      len,
+      noop_deleter_callback,
+      std::ptr::null_mut(),
+    )
+  }
+  .make_shared();
+  let array_buffer: v8::Local<v8::Value> =
+    v8::ArrayBuffer::with_backing_store(scope, &backing_store).into();
+  Ok(array_buffer.into())
+}
+
+#[op(fast)]
+pub fn op_ffi_buf_copy_into<FP>(
+  state: &mut deno_core::OpState,
+  src: usize,
+  offset: usize,
+  dst: &mut [u8],
+  len: usize,
+) -> Result<(), AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#copyInto");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  if dst.len() < len {
+    Err(range_error(
+      "Destination length is smaller than source length",
+    ))
+  } else {
+    let src = src as *const c_void;
+
+    // SAFETY: Offset is user defined.
+    let src = unsafe { src.add(offset) as *const u8 };
+
+    // SAFETY: src is user defined.
+    // dest is properly aligned and is valid for writes of len * size_of::<T>() bytes.
+    unsafe { ptr::copy::<u8>(src, dst.as_mut_ptr(), len) };
+    Ok(())
+  }
+}
+
+#[op(v8)]
+pub fn op_ffi_cstr_read<FP, 'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<serde_v8::Value<'scope>, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getCString");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid CString pointer, pointer is null"));
+  }
+
+  // SAFETY: Offset is user defined.
+  let ptr = unsafe { ptr.add(offset) };
+
+  // SAFETY: Pointer is user provided.
+  let cstr = unsafe { CStr::from_ptr(ptr as *const c_char) }
+    .to_str()
+    .map_err(|_| type_error("Invalid CString pointer, not valid UTF-8"))?;
+  let value: v8::Local<v8::Value> = v8::String::new(scope, cstr)
+    .ok_or_else(|| {
+      type_error("Invalid CString pointer, string exceeds max length")
+    })?
+    .into();
+  Ok(value.into())
+}
+
+#[op(fast)]
+pub fn op_ffi_read_bool<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<bool, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getBool");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid bool pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe { ptr::read_unaligned::<bool>(ptr.add(offset) as *const bool) })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_u8<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<u32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getUint8");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid u8 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe { ptr::read_unaligned::<u8>(ptr.add(offset) as *const u8) as u32 })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_i8<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<i32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getInt8");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid i8 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe { ptr::read_unaligned::<i8>(ptr.add(offset) as *const i8) as i32 })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_u16<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<u32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getUint16");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid u16 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe {
+    ptr::read_unaligned::<u16>(ptr.add(offset) as *const u16) as u32
+  })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_i16<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<i32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getInt16");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid i16 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe {
+    ptr::read_unaligned::<i16>(ptr.add(offset) as *const i16) as i32
+  })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_u32<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<u32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getUint32");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid u32 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe {
+    ptr::read_unaligned::<u32>(ptr.add(offset) as *const u32) as u32
+  })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_i32<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<i32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getInt32");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid i32 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe {
+    ptr::read_unaligned::<i32>(ptr.add(offset) as *const i32) as i32
+  })
+}
+
+#[op]
+pub fn op_ffi_read_u64<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+  out: &mut [u32],
+) -> Result<(), AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getBigUint64");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let outptr = out.as_mut_ptr() as *mut u64;
+
+  assert!(
+    out.len() >= (std::mem::size_of::<u64>() / std::mem::size_of::<u32>())
+  );
+  assert_eq!((outptr as usize % std::mem::size_of::<u64>()), 0);
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid u64 pointer, pointer is null"));
+  }
+
+  let value =
+  // SAFETY: ptr and offset are user provided.
+    unsafe { ptr::read_unaligned::<u64>(ptr.add(offset) as *const u64) };
+
+  // SAFETY: Length and alignment of out slice were asserted to be correct.
+  unsafe { *outptr = value };
+  Ok(())
+}
+
+#[op(fast)]
+pub fn op_ffi_read_i64<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+  out: &mut [u32],
+) -> Result<(), AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getBigUint64");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let outptr = out.as_mut_ptr() as *mut i64;
+
+  assert!(
+    out.len() >= (std::mem::size_of::<i64>() / std::mem::size_of::<u32>())
+  );
+  assert_eq!((outptr as usize % std::mem::size_of::<i64>()), 0);
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid i64 pointer, pointer is null"));
+  }
+
+  let value =
+  // SAFETY: ptr and offset are user provided.
+    unsafe { ptr::read_unaligned::<i64>(ptr.add(offset) as *const i64) };
+  // SAFETY: Length and alignment of out slice were asserted to be correct.
+  unsafe { *outptr = value };
+  Ok(())
+}
+
+#[op(fast)]
+pub fn op_ffi_read_f32<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<f32, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getFloat32");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid f32 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe { ptr::read_unaligned::<f32>(ptr.add(offset) as *const f32) })
+}
+
+#[op(fast)]
+pub fn op_ffi_read_f64<FP>(
+  state: &mut deno_core::OpState,
+  ptr: usize,
+  offset: usize,
+) -> Result<f64, AnyError>
+where
+  FP: FfiPermissions + 'static,
+{
+  check_unstable(state, "Deno.UnsafePointerView#getFloat64");
+
+  let permissions = state.borrow_mut::<FP>();
+  permissions.check(None)?;
+
+  let ptr = ptr as *const c_void;
+
+  if ptr.is_null() {
+    return Err(type_error("Invalid f64 pointer, pointer is null"));
+  }
+
+  // SAFETY: ptr and offset are user provided.
+  Ok(unsafe { ptr::read_unaligned::<f64>(ptr.add(offset) as *const f64) })
+}

ext/ffi/static.rs

@@ -0,0 +1,146 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+use crate::dlfcn::DynamicLibraryResource;
+use crate::symbol::NativeType;
+use crate::MAX_SAFE_INTEGER;
+use crate::MIN_SAFE_INTEGER;
+use deno_core::error::type_error;
+use deno_core::error::AnyError;
+use deno_core::op;
+use deno_core::serde_v8;
+use deno_core::v8;
+use deno_core::ResourceId;
+use std::ptr;
+
+#[op(v8)]
+pub fn op_ffi_get_static<'scope>(
+  scope: &mut v8::HandleScope<'scope>,
+  state: &mut deno_core::OpState,
+  rid: ResourceId,
+  name: String,
+  static_type: NativeType,
+) -> Result<serde_v8::Value<'scope>, AnyError> {
+  let resource = state.resource_table.get::<DynamicLibraryResource>(rid)?;
+
+  let data_ptr = resource.get_static(name)?;
+
+  Ok(match static_type {
+    NativeType::Void => {
+      return Err(type_error("Invalid FFI static type 'void'"));
+    }
+    NativeType::Bool => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const bool) };
+      let boolean: v8::Local<v8::Value> =
+        v8::Boolean::new(scope, result).into();
+      boolean.into()
+    }
+    NativeType::U8 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const u8) };
+      let number: v8::Local<v8::Value> =
+        v8::Integer::new_from_unsigned(scope, result as u32).into();
+      number.into()
+    }
+    NativeType::I8 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const i8) };
+      let number: v8::Local<v8::Value> =
+        v8::Integer::new(scope, result as i32).into();
+      number.into()
+    }
+    NativeType::U16 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const u16) };
+      let number: v8::Local<v8::Value> =
+        v8::Integer::new_from_unsigned(scope, result as u32).into();
+      number.into()
+    }
+    NativeType::I16 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const i16) };
+      let number: v8::Local<v8::Value> =
+        v8::Integer::new(scope, result as i32).into();
+      number.into()
+    }
+    NativeType::U32 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const u32) };
+      let number: v8::Local<v8::Value> =
+        v8::Integer::new_from_unsigned(scope, result).into();
+      number.into()
+    }
+    NativeType::I32 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const i32) };
+      let number: v8::Local<v8::Value> = v8::Integer::new(scope, result).into();
+      number.into()
+    }
+    NativeType::U64 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const u64) };
+      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as u64 {
+        v8::BigInt::new_from_u64(scope, result).into()
+      } else {
+        v8::Number::new(scope, result as f64).into()
+      };
+      integer.into()
+    }
+    NativeType::I64 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const i64) };
+      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as i64
+        || result < MIN_SAFE_INTEGER as i64
+      {
+        v8::BigInt::new_from_i64(scope, result).into()
+      } else {
+        v8::Number::new(scope, result as f64).into()
+      };
+      integer.into()
+    }
+    NativeType::USize => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const usize) };
+      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as usize
+      {
+        v8::BigInt::new_from_u64(scope, result as u64).into()
+      } else {
+        v8::Number::new(scope, result as f64).into()
+      };
+      integer.into()
+    }
+    NativeType::ISize => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const isize) };
+      let integer: v8::Local<v8::Value> =
+        if !(MIN_SAFE_INTEGER..=MAX_SAFE_INTEGER).contains(&result) {
+          v8::BigInt::new_from_i64(scope, result as i64).into()
+        } else {
+          v8::Number::new(scope, result as f64).into()
+        };
+      integer.into()
+    }
+    NativeType::F32 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const f32) };
+      let number: v8::Local<v8::Value> =
+        v8::Number::new(scope, result as f64).into();
+      number.into()
+    }
+    NativeType::F64 => {
+      // SAFETY: ptr is user provided
+      let result = unsafe { ptr::read_unaligned(data_ptr as *const f64) };
+      let number: v8::Local<v8::Value> = v8::Number::new(scope, result).into();
+      number.into()
+    }
+    NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
+      let result = data_ptr as u64;
+      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as u64 {
+        v8::BigInt::new_from_u64(scope, result).into()
+      } else {
+        v8::Number::new(scope, result as f64).into()
+      };
+      integer.into()
+    }
+  })
+}

ext/ffi/symbol.rs

@@ -0,0 +1,63 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+/// Defines the accepted types that can be used as
+/// parameters and return values in FFI.
+#[derive(Clone, Copy, Debug, serde::Deserialize, Eq, PartialEq)]
+#[serde(rename_all = "lowercase")]
+pub enum NativeType {
+  Void,
+  Bool,
+  U8,
+  I8,
+  U16,
+  I16,
+  U32,
+  I32,
+  U64,
+  I64,
+  USize,
+  ISize,
+  F32,
+  F64,
+  Pointer,
+  Buffer,
+  Function,
+}
+
+impl From<NativeType> for libffi::middle::Type {
+  fn from(native_type: NativeType) -> Self {
+    match native_type {
+      NativeType::Void => libffi::middle::Type::void(),
+      NativeType::U8 | NativeType::Bool => libffi::middle::Type::u8(),
+      NativeType::I8 => libffi::middle::Type::i8(),
+      NativeType::U16 => libffi::middle::Type::u16(),
+      NativeType::I16 => libffi::middle::Type::i16(),
+      NativeType::U32 => libffi::middle::Type::u32(),
+      NativeType::I32 => libffi::middle::Type::i32(),
+      NativeType::U64 => libffi::middle::Type::u64(),
+      NativeType::I64 => libffi::middle::Type::i64(),
+      NativeType::USize => libffi::middle::Type::usize(),
+      NativeType::ISize => libffi::middle::Type::isize(),
+      NativeType::F32 => libffi::middle::Type::f32(),
+      NativeType::F64 => libffi::middle::Type::f64(),
+      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
+        libffi::middle::Type::pointer()
+      }
+    }
+  }
+}
+
+#[derive(Clone)]
+pub struct Symbol {
+  pub cif: libffi::middle::Cif,
+  pub ptr: libffi::middle::CodePtr,
+  pub parameter_types: Vec<NativeType>,
+  pub result_type: NativeType,
+  pub can_callback: bool,
+}
+
+#[allow(clippy::non_send_fields_in_send_ty)]
+// SAFETY: unsafe trait must have unsafe implementation
+unsafe impl Send for Symbol {}
+// SAFETY: unsafe trait must have unsafe implementation
+unsafe impl Sync for Symbol {}

ext/ffi/turbocall.rs

@@ -9,7 +9,7 @@ use dynasmrt::dynasm;
 use dynasmrt::DynasmApi;
 use dynasmrt::ExecutableBuffer;
 
-use crate::needs_unwrap;
+use crate::dlfcn::needs_unwrap;
 use crate::NativeType;
 use crate::Symbol;
 
@@ -562,7 +562,7 @@ impl SysVAmd64 {
   fn must_wrap_return_value_in_typed_array(&self, rv: NativeType) -> bool {
     // V8 only supports i32 and u32 return types for integers
     // We support 64 bit integers by wrapping them in a TypedArray out parameter
-    crate::needs_unwrap(rv)
+    crate::dlfcn::needs_unwrap(rv)
   }
 
   fn finalize(self) -> ExecutableBuffer {
@@ -1073,7 +1073,7 @@ impl Aarch64Apple {
   fn must_wrap_return_value_in_typed_array(&self, rv: NativeType) -> bool {
     // V8 only supports i32 and u32 return types for integers
     // We support 64 bit integers by wrapping them in a TypedArray out parameter
-    crate::needs_unwrap(rv)
+    crate::dlfcn::needs_unwrap(rv)
   }
 
   fn finalize(self) -> ExecutableBuffer {
@@ -1429,7 +1429,7 @@ impl Win64 {
   fn must_wrap_return_value_in_typed_array(&self, rv: NativeType) -> bool {
     // V8 only supports i32 and u32 return types for integers
     // We support 64 bit integers by wrapping them in a TypedArray out parameter
-    crate::needs_unwrap(rv)
+    crate::dlfcn::needs_unwrap(rv)
   }
 
   fn finalize(self) -> ExecutableBuffer {