Support unions of objects in overloads

Part of #20513, implementing the parts useful for WebGL.

components/script/dom/bindings/codegen/CodegenRust.py

@@ -344,11 +344,16 @@ class CGMethodCall(CGThing):
 
             distinguishingIndex = method.distinguishingIndexForArgCount(argCount)
 
-            # We can't handle unions at the distinguishing index.
+            # We can't handle unions of non-object values at the distinguishing index.
             for (returnType, args) in possibleSignatures:
-                if args[distinguishingIndex].type.isUnion():
+                type = args[distinguishingIndex].type
-                    raise TypeError("No support for unions as distinguishing "
+                if type.isUnion():
-                                    "arguments yet: %s",
+                    if type.nullable():
+                        type = type.inner
+                    for type in type.flatMemberTypes:
+                        if not (type.isObject() or type.isNonCallbackInterface()):
+                            raise TypeError("No support for unions with non-object variants "
+                                            "as distinguishing arguments yet: %s",
                                             args[distinguishingIndex].location)
 
             # Convert all our arguments up to the distinguishing index.
@@ -388,6 +393,7 @@ class CGMethodCall(CGThing):
             interfacesSigs = [
                 s for s in possibleSignatures
                 if (s[1][distinguishingIndex].type.isObject() or
+                    s[1][distinguishingIndex].type.isUnion() or
                     s[1][distinguishingIndex].type.isNonCallbackInterface())]
             # There might be more than one of these; we need to check
             # which ones we unwrap to.
@@ -2366,7 +2372,6 @@ def UnionTypes(descriptors, dictionaries, callbacks, typedefs, config):
         'dom::bindings::conversions::ConversionBehavior',
         'dom::bindings::conversions::StringificationBehavior',
         'dom::bindings::conversions::root_from_handlevalue',
-        'dom::bindings::error::throw_not_in_union',
         'std::ptr::NonNull',
         'dom::bindings::mozmap::MozMap',
         'dom::bindings::root::DomRoot',
@@ -4450,8 +4455,8 @@ class CGUnionConversionStruct(CGThing):
                 other.append(booleanConversion[0])
             conversions.append(CGList(other, "\n\n"))
         conversions.append(CGGeneric(
-            "throw_not_in_union(cx, \"%s\");\n"
+            "Ok(ConversionResult::Failure(\"argument could not be converted to any of: %s\".into()))" % ", ".join(names)
-            "Err(())" % ", ".join(names)))
+        ))
         method = CGWrapper(
             CGIndenter(CGList(conversions, "\n\n")),
             pre="unsafe fn from_jsval(cx: *mut JSContext,\n"

components/script/dom/bindings/error.rs

@@ -255,14 +255,6 @@ pub unsafe fn report_pending_exception(cx: *mut JSContext, dispatch_event: bool)
     }
 }
 
-/// Throw an exception to signal that a `JSVal` can not be converted to any of
-/// the types in an IDL union type.
-pub unsafe fn throw_not_in_union(cx: *mut JSContext, names: &'static str) {
-    assert!(!JS_IsExceptionPending(cx));
-    let error = format!("argument could not be converted to any of: {}", names);
-    throw_type_error(cx, &error);
-}
-
 /// Throw an exception to signal that a `JSObject` can not be converted to a
 /// given DOM type.
 pub unsafe fn throw_invalid_this(cx: *mut JSContext, proto_id: u16) {

components/script/dom/webgl2renderingcontext.rs

@@ -240,14 +240,18 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
         self.base.GenerateMipmap(target)
     }
 
-    #[allow(unsafe_code)]
     /// https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
-    unsafe fn BufferData(&self, cx: *mut JSContext, target: u32, data: *mut JSObject, usage: u32) -> Fallible<()> {
+    fn BufferData(
-        self.base.BufferData(cx, target, data, usage)
+        &self,
+        target: u32,
+        data: Option<ArrayBufferViewOrArrayBuffer>,
+        usage: u32,
+    ) {
+        self.base.BufferData(target, data, usage)
     }
 
     /// https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
-    fn BufferData_(&self, target: u32, size: i64, usage: u32) -> Fallible<()> {
+    fn BufferData_(&self, target: u32, size: i64, usage: u32) {
         self.base.BufferData_(target, size, usage)
     }
 

components/script/dom/webglrenderingcontext.rs

@@ -1326,19 +1326,6 @@ impl Drop for WebGLRenderingContext {
     }
 }
 
-#[allow(unsafe_code)]
-unsafe fn fallible_array_buffer_view_to_vec(
-    cx: *mut JSContext,
-    abv: *mut JSObject,
-) -> Result<Vec<u8>, Error> {
-    assert!(!abv.is_null());
-    typedarray!(in(cx) let array_buffer_view: ArrayBufferView = abv);
-    match array_buffer_view {
-        Ok(v) => Ok(v.to_vec()),
-        Err(_) => Err(Error::Type("Not an ArrayBufferView".to_owned())),
-    }
-}
-
 impl WebGLRenderingContextMethods for WebGLRenderingContext {
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.1
     fn Canvas(&self) -> DomRoot<HTMLCanvasElement> {
@@ -1894,52 +1881,44 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
         handle_potential_webgl_error!(self, texture.generate_mipmap());
     }
 
-    #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
-    unsafe fn BufferData(
+    fn BufferData(
         &self,
-        cx: *mut JSContext,
         target: u32,
-        data: *mut JSObject,
+        data: Option<ArrayBufferViewOrArrayBuffer>,
         usage: u32,
-    ) -> ErrorResult {
+    ) {
-        if data.is_null() {
+        let data = match data {
-            return Ok(self.webgl_error(InvalidValue));
+            Some(ArrayBufferViewOrArrayBuffer::ArrayBuffer(data)) => data.to_vec(),
-        }
+            Some(ArrayBufferViewOrArrayBuffer::ArrayBufferView(data)) => data.to_vec(),
-
+            None => return self.webgl_error(InvalidValue),
-        typedarray!(in(cx) let array_buffer: ArrayBuffer = data);
-        let data_vec = match array_buffer {
-            Ok(data) => data.to_vec(),
-            Err(_) => fallible_array_buffer_view_to_vec(cx, data)?,
         };
 
-        let bound_buffer = handle_potential_webgl_error!(self, self.bound_buffer(target), return Ok(()));
+        let bound_buffer = handle_potential_webgl_error!(self, self.bound_buffer(target), return);
         let bound_buffer = match bound_buffer {
             Some(bound_buffer) => bound_buffer,
-            None => return Ok(self.webgl_error(InvalidOperation)),
+            None => return self.webgl_error(InvalidOperation),
         };
 
-        handle_potential_webgl_error!(self, bound_buffer.buffer_data(target, data_vec, usage));
+        handle_potential_webgl_error!(self, bound_buffer.buffer_data(target, data, usage));
-        Ok(())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
-    fn BufferData_(&self, target: u32, size: i64, usage: u32) -> ErrorResult {
+    fn BufferData_(&self, target: u32, size: i64, usage: u32) {
-        let bound_buffer = handle_potential_webgl_error!(self, self.bound_buffer(target), return Ok(()));
+        let bound_buffer = handle_potential_webgl_error!(self, self.bound_buffer(target), return);
         let bound_buffer = match bound_buffer {
             Some(bound_buffer) => bound_buffer,
-            None => return Ok(self.webgl_error(InvalidOperation)),
+            None => return self.webgl_error(InvalidOperation),
         };
 
         if size < 0 {
-            return Ok(self.webgl_error(InvalidValue));
+            return self.webgl_error(InvalidValue);
         }
 
         // FIXME: Allocating a buffer based on user-requested size is
         // not great, but we don't have a fallible allocation to try.
         let data = vec![0u8; size as usize];
         handle_potential_webgl_error!(self, bound_buffer.buffer_data(target, data, usage));
-        Ok(())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5

components/script/dom/webidls/WebGL2RenderingContext.webidl

@@ -305,10 +305,7 @@ interface WebGL2RenderingContextBase
   /* Buffer objects */
   // WebGL1:
   // BUG: https://github.com/KhronosGroup/WebGL/issues/2216
-  // FIXME(xanewok): https://github.com/servo/servo/issues/20513
+  void bufferData(GLenum target, /*[AllowShared]*/ BufferSource? data, GLenum usage);
-  [Throws]
-  void bufferData(GLenum target, object? data, GLenum usage);
-  [Throws]
   void bufferData(GLenum target, GLsizeiptr size, GLenum usage);
   void bufferSubData(GLenum target, GLintptr dstByteOffset, /*[AllowShared]*/ BufferSource srcData);
   // WebGL2:

components/script/dom/webidls/WebGLRenderingContext.webidl

@@ -688,10 +688,7 @@ interface WebGLRenderingContext
 {
     // BUG: https://github.com/KhronosGroup/WebGL/issues/2216
 
-    // FIXME(xanewok): https://github.com/servo/servo/issues/20513
+    void bufferData(GLenum target, /*[AllowShared]*/ BufferSource? data, GLenum usage);
-    [Throws]
-    void bufferData(GLenum target, object? data, GLenum usage);
-    [Throws]
     void bufferData(GLenum target, GLsizeiptr size, GLenum usage);
     void bufferSubData(GLenum target, GLintptr offset, /*[AllowShared]*/ BufferSource data);
 

tests/wpt/webgl/meta/conformance/buffers/buffer-data-and-buffer-sub-data.html.ini

@@ -1,6 +0,0 @@
-[buffer-data-and-buffer-sub-data.html]
-  bug: https://github.com/servo/servo/issues/20513
-  expected: ERROR
-  [WebGL test #27: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
-    expected: FAIL
-

tests/wpt/webgl/meta/conformance/misc/type-conversion-test.html.ini

@@ -1,20 +0,0 @@
-[type-conversion-test.html]
-  bug: https://github.com/servo/servo/issues/20513
-  [WebGL test #340: context.bufferData(context.ARRAY_BUFFER, argument, context.STATIC_DRAW) should be undefined. Threw exception TypeError: Not an ArrayBufferView]
-    expected: FAIL
-
-  [WebGL test #407: context.bufferData(context.ARRAY_BUFFER, argument, context.STATIC_DRAW) should be undefined. Threw exception TypeError: Not an ArrayBufferView]
-    expected: FAIL
-
-  [WebGL test #474: context.bufferData(context.ARRAY_BUFFER, argument, context.STATIC_DRAW) should be undefined. Threw exception TypeError: Not an ArrayBufferView]
-    expected: FAIL
-
-  [WebGL test #541: context.bufferData(context.ARRAY_BUFFER, argument, context.STATIC_DRAW) should be undefined. Threw exception TypeError: Not an ArrayBufferView]
-    expected: FAIL
-
-  [WebGL test #608: context.bufferData(context.ARRAY_BUFFER, argument, context.STATIC_DRAW) should be undefined. Threw exception TypeError: Not an ArrayBufferView]
-    expected: FAIL
-
-  [WebGL test #675: context.bufferData(context.ARRAY_BUFFER, argument, context.STATIC_DRAW) should be undefined. Threw exception TypeError: Not an ArrayBufferView]
-    expected: FAIL
-