Make all V8 heap object types subtypes of v8::Data (#351)

In v8.h, not all heap object classes actually derive from `v8::Data`,
but this seems to be a mistake, because this hierarchy does definitely
exists in V8's internal source code.

src/binding.cc

@@ -266,10 +266,6 @@ const v8::Data* v8__Local__New(v8::Isolate* isolate, const v8::Data& other) {
   return local_to_ptr(v8::Local<v8::Data>::New(isolate, ptr_to_local(&other)));
 }
 
-bool v8__Local__EQ(const v8::Data& self, const v8::Data& other) {
-  return ptr_to_local(&self) == ptr_to_local(&other);
-}
-
 const v8::Data* v8__Global__New(v8::Isolate* isolate, const v8::Data& other) {
   // We have to use `std::move()` here because v8 disables the copy constructor
   // for class `v8::Global`.
@@ -314,6 +310,10 @@ const v8::Module* v8__ScriptCompiler__CompileModule(
   }
 }
 
+bool v8__Data__EQ(const v8::Data& self, const v8::Data& other) {
+  return ptr_to_local(&self) == ptr_to_local(&other);
+}
+
 bool v8__Value__IsUndefined(const v8::Value& self) {
   return self.IsUndefined();
 }

src/data.rs

@@ -57,7 +57,7 @@ macro_rules! impl_partial_eq {
   { $rhs:ident for $type:ident use identity } => {
     impl<'sc> PartialEq<Local<'sc, $rhs>> for Local<'sc, $type> {
       fn eq(&self, other: &Local<'sc, $rhs>) -> bool {
-        unsafe { v8__Local__EQ(transmute(*self), transmute(*other)) }
+        self.eq_identity((*other).into())
       }
     }
   };
@@ -71,7 +71,13 @@ macro_rules! impl_partial_eq {
 }
 
 extern "C" {
-  fn v8__Local__EQ(this: *const Data, other: *const Data) -> bool;
+  fn v8__Data__EQ(this: *const Data, other: *const Data) -> bool;
+}
+
+impl Data {
+  fn eq_identity(&self, other: Local<Self>) -> bool {
+    unsafe { v8__Data__EQ(self, &*other) }
+  }
 }
 
 #[derive(Clone, Copy, Debug)]
@@ -93,28 +99,26 @@ impl Display for TryFromTypeError {
 
 impl Error for TryFromTypeError {}
 
-/// A sandboxed execution context with its own set of built-in objects
-/// and functions.
-#[repr(C)]
-pub struct Context(Opaque);
-
-impl_deref! { Data for Context }
-impl_eq! { for Context }
-impl_partial_eq! { Context for Context use identity }
-
 /// The superclass of objects that can reside on V8's heap.
 #[repr(C)]
 pub struct Data(Opaque);
 
 impl_from! { AccessorSignature for Data }
 impl_from! { Context for Data }
+impl_from! { Message for Data }
 impl_from! { Module for Data }
+impl_from! { PrimitiveArray for Data }
 impl_from! { Private for Data }
+impl_from! { Script for Data }
+impl_from! { ScriptOrModule for Data }
 impl_from! { Signature for Data }
+impl_from! { StackFrame for Data }
+impl_from! { StackTrace for Data }
 impl_from! { Template for Data }
 impl_from! { FunctionTemplate for Data }
 impl_from! { ObjectTemplate for Data }
 impl_from! { UnboundModuleScript for Data }
+impl_from! { UnboundScript for Data }
 impl_from! { Value for Data }
 impl_from! { External for Data }
 impl_from! { Object for Data }
@@ -161,13 +165,21 @@ impl_from! { Integer for Data }
 impl_from! { Int32 for Data }
 impl_from! { Uint32 for Data }
 impl_partial_eq! { AccessorSignature for Data use identity }
+impl_partial_eq! { Context for Data use identity }
+impl_partial_eq! { Message for Data use identity }
 impl_partial_eq! { Module for Data use identity }
+impl_partial_eq! { PrimitiveArray for Data use identity }
 impl_partial_eq! { Private for Data use identity }
+impl_partial_eq! { Script for Data use identity }
+impl_partial_eq! { ScriptOrModule for Data use identity }
 impl_partial_eq! { Signature for Data use identity }
+impl_partial_eq! { StackFrame for Data use identity }
+impl_partial_eq! { StackTrace for Data use identity }
 impl_partial_eq! { Template for Data use identity }
 impl_partial_eq! { FunctionTemplate for Data use identity }
 impl_partial_eq! { ObjectTemplate for Data use identity }
 impl_partial_eq! { UnboundModuleScript for Data use identity }
+impl_partial_eq! { UnboundScript for Data use identity }
 impl_partial_eq! { External for Data use identity }
 impl_partial_eq! { Object for Data use identity }
 impl_partial_eq! { Array for Data use identity }
@@ -215,6 +227,25 @@ impl_eq! { for AccessorSignature }
 impl_partial_eq! { Data for AccessorSignature use identity }
 impl_partial_eq! { AccessorSignature for AccessorSignature use identity }
 
+/// A sandboxed execution context with its own set of built-in objects
+/// and functions.
+#[repr(C)]
+pub struct Context(Opaque);
+
+impl_deref! { Data for Context }
+impl_eq! { for Context }
+impl_partial_eq! { Data for Context use identity }
+impl_partial_eq! { Context for Context use identity }
+
+/// An error message.
+#[repr(C)]
+pub struct Message(Opaque);
+
+impl_deref! { Data for Message }
+impl_eq! { for Message }
+impl_partial_eq! { Data for Message use identity }
+impl_partial_eq! { Message for Message use identity }
+
 /// A compiled JavaScript module.
 #[repr(C)]
 pub struct Module(Opaque);
@@ -224,6 +255,19 @@ impl_eq! { for Module }
 impl_partial_eq! { Data for Module use identity }
 impl_partial_eq! { Module for Module use identity }
 
+/// An array to hold Primitive values. This is used by the embedder to
+/// pass host defined options to the ScriptOptions during compilation.
+///
+/// This is passed back to the embedder as part of
+/// HostImportModuleDynamicallyCallback for module loading.
+#[repr(C)]
+pub struct PrimitiveArray(Opaque);
+
+impl_deref! { Data for PrimitiveArray }
+impl_eq! { for PrimitiveArray }
+impl_partial_eq! { Data for PrimitiveArray use identity }
+impl_partial_eq! { PrimitiveArray for PrimitiveArray use identity }
+
 /// A private symbol
 ///
 /// This is an experimental feature. Use at your own risk.
@@ -235,6 +279,28 @@ impl_eq! { for Private }
 impl_partial_eq! { Data for Private use identity }
 impl_partial_eq! { Private for Private use identity }
 
+/// A compiled JavaScript script, tied to a Context which was active when the
+/// script was compiled.
+#[repr(C)]
+pub struct Script(Opaque);
+
+impl_deref! { Data for Script }
+impl_eq! { for Script }
+impl_partial_eq! { Data for Script use identity }
+impl_partial_eq! { Script for Script use identity }
+
+/// A container type that holds relevant metadata for module loading.
+///
+/// This is passed back to the embedder as part of
+/// HostImportModuleDynamicallyCallback for module loading.
+#[repr(C)]
+pub struct ScriptOrModule(Opaque);
+
+impl_deref! { Data for ScriptOrModule }
+impl_eq! { for ScriptOrModule }
+impl_partial_eq! { Data for ScriptOrModule use identity }
+impl_partial_eq! { ScriptOrModule for ScriptOrModule use identity }
+
 /// A Signature specifies which receiver is valid for a function.
 ///
 /// A receiver matches a given signature if the receiver (or any of its
@@ -249,6 +315,26 @@ impl_eq! { for Signature }
 impl_partial_eq! { Data for Signature use identity }
 impl_partial_eq! { Signature for Signature use identity }
 
+/// A single JavaScript stack frame.
+#[repr(C)]
+pub struct StackFrame(Opaque);
+
+impl_deref! { Data for StackFrame }
+impl_eq! { for StackFrame }
+impl_partial_eq! { Data for StackFrame use identity }
+impl_partial_eq! { StackFrame for StackFrame use identity }
+
+/// Representation of a JavaScript stack trace. The information collected is a
+/// snapshot of the execution stack and the information remains valid after
+/// execution continues.
+#[repr(C)]
+pub struct StackTrace(Opaque);
+
+impl_deref! { Data for StackTrace }
+impl_eq! { for StackTrace }
+impl_partial_eq! { Data for StackTrace use identity }
+impl_partial_eq! { StackTrace for StackTrace use identity }
+
 /// The superclass of object and function templates.
 #[repr(C)]
 pub struct Template(Opaque);
@@ -398,6 +484,15 @@ impl_eq! { for UnboundModuleScript }
 impl_partial_eq! { Data for UnboundModuleScript use identity }
 impl_partial_eq! { UnboundModuleScript for UnboundModuleScript use identity }
 
+/// A compiled JavaScript script, not yet tied to a Context.
+#[repr(C)]
+pub struct UnboundScript(Opaque);
+
+impl_deref! { Data for UnboundScript }
+impl_eq! { for UnboundScript }
+impl_partial_eq! { Data for UnboundScript use identity }
+impl_partial_eq! { UnboundScript for UnboundScript use identity }
+
 /// The superclass of all JavaScript values and objects.
 #[repr(C)]
 pub struct Value(Opaque);
@@ -1256,62 +1351,3 @@ impl_partial_eq! { Primitive for Uint32 use strict_equals }
 impl_partial_eq! { Number for Uint32 use strict_equals }
 impl_partial_eq! { Integer for Uint32 use strict_equals }
 impl_partial_eq! { Uint32 for Uint32 use strict_equals }
-
-/// An error message.
-#[repr(C)]
-pub struct Message(Opaque);
-
-impl_eq! { for Message }
-impl_partial_eq! { Message for Message use identity }
-
-/// An array to hold Primitive values. This is used by the embedder to
-/// pass host defined options to the ScriptOptions during compilation.
-///
-/// This is passed back to the embedder as part of
-/// HostImportModuleDynamicallyCallback for module loading.
-#[repr(C)]
-pub struct PrimitiveArray(Opaque);
-
-impl_eq! { for PrimitiveArray }
-impl_partial_eq! { PrimitiveArray for PrimitiveArray use identity }
-
-/// A compiled JavaScript script, tied to a Context which was active when the
-/// script was compiled.
-#[repr(C)]
-pub struct Script(Opaque);
-
-impl_eq! { for Script }
-impl_partial_eq! { Script for Script use identity }
-
-/// A container type that holds relevant metadata for module loading.
-///
-/// This is passed back to the embedder as part of
-/// HostImportModuleDynamicallyCallback for module loading.
-#[repr(C)]
-pub struct ScriptOrModule(Opaque);
-
-impl_eq! { for ScriptOrModule }
-impl_partial_eq! { ScriptOrModule for ScriptOrModule use identity }
-
-/// A single JavaScript stack frame.
-#[repr(C)]
-pub struct StackFrame(Opaque);
-
-impl_eq! { for StackFrame }
-impl_partial_eq! { StackFrame for StackFrame use identity }
-
-/// Representation of a JavaScript stack trace. The information collected is a
-/// snapshot of the execution stack and the information remains valid after
-/// execution continues.
-#[repr(C)]
-pub struct StackTrace(Opaque);
-
-impl_eq! { for StackTrace }
-impl_partial_eq! { StackTrace for StackTrace use identity }
-
-/// A compiled JavaScript script, not yet tied to a Context.
-#[repr(C)]
-pub struct UnboundScript(Opaque);
-
-impl_eq! { for UnboundScript }
-impl_partial_eq! { UnboundScript for UnboundScript use identity }