IDL compiler: Turn ArrayBufferView into a built-in type

- Turn ArrayBufferView into a built-in type
  (was a union of all typed arrays)
- Remove flattened_member_types_in_original_order
  (turned out that there was no need to flatten unions)

Bug: 839389
Change-Id: I1a6eecf217b1d8021b6e7b5b520500f43c57fb10
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2032695Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737694}

third_party/blink/renderer/bindings/scripts/bind_gen/interface.py

@@ -860,9 +860,7 @@ def _make_overload_dispatcher_per_arg_size(cg_context, items):
             _format("{}::HasInstance(${isolate}, {value})", v8_bridge_name))
 
     is_typedef_name = lambda t, name: t.is_typedef and t.identifier == name
-    func_like_a = find(
-        lambda t, u: is_typedef_name(t.unwrap(typedef=False),
-                                     "ArrayBufferView"))
+    func_like_a = find(lambda t, u: u.is_array_buffer_view)
     func_like_b = find(
         lambda t, u: is_typedef_name(t.unwrap(typedef=False), "BufferSource"))
     if func_like_a or func_like_b:
@@ -3188,5 +3186,5 @@ def generate_interface(interface):
 
 
 def generate_interfaces(web_idl_database):
-    interface = web_idl_database.find("Element")
+    interface = web_idl_database.find("Blob")
     generate_interface(interface)

third_party/blink/renderer/bindings/scripts/web_idl/idl_type.py

@@ -317,6 +317,11 @@ class IdlType(WithExtendedAttributes, WithDebugInfo):
         """Returns True if this is ArrayBuffer."""
         return False
 
+    @property
+    def is_array_buffer_view(self):
+        """Returns True if this is ArrayBufferView."""
+        return False
+
     @property
     def is_data_view(self):
         """Returns True if this is DataView."""
@@ -559,7 +564,17 @@ class SimpleType(IdlType):
     _TYPED_ARRAY_TYPES = ('Int8Array', 'Int16Array', 'Int32Array',
                           'Uint8Array', 'Uint16Array', 'Uint32Array',
                           'Uint8ClampedArray', 'Float32Array', 'Float64Array')
-    _BUFFER_SOURCE_TYPES = ('ArrayBuffer', 'DataView') + _TYPED_ARRAY_TYPES
+    # ArrayBufferView is not defined as a buffer source type in Web IDL, it's
+    # defined as an union type of all typed array types.  However, practically
+    # it's much more convenient and reasonable for most of (if not all) use
+    # cases to treat ArrayBufferView as a buffer source type than as an union
+    # type.
+    # https://heycam.github.io/webidl/#ArrayBufferView
+    #
+    # Note that BufferSource is an union type as defined in Web IDL.
+    # https://heycam.github.io/webidl/#BufferSource
+    _BUFFER_SOURCE_TYPES = (
+        ('ArrayBuffer', 'ArrayBufferView', 'DataView') + _TYPED_ARRAY_TYPES)
     _MISC_TYPES = ('any', 'boolean', 'object', 'symbol', 'void')
     _VALID_TYPES = set(_NUMERIC_TYPES + _STRING_TYPES + _BUFFER_SOURCE_TYPES +
                        _MISC_TYPES)
@@ -629,6 +644,10 @@ class SimpleType(IdlType):
     def is_array_buffer(self):
         return self._name == 'ArrayBuffer'
 
+    @property
+    def is_array_buffer_view(self):
+        return self._name == 'ArrayBufferView'
+
     @property
     def is_data_view(self):
         return self._name == 'DataView'
@@ -1144,10 +1163,6 @@ class UnionType(IdlType):
 
     @property
     def flattened_member_types(self):
-        return set(self.flattened_member_types_in_original_order)
-
-    @property
-    def flattened_member_types_in_original_order(self):
         def flatten(idl_type):
             if idl_type.is_union:
                 return functools.reduce(
@@ -1160,7 +1175,7 @@ class UnionType(IdlType):
             else:
                 return [idl_type]
 
-        return flatten(self)
+        return set(flatten(self))
 
     @property
     def union_definition_object(self):

third_party/blink/renderer/bindings/scripts/web_idl/ir_builder.py

@@ -688,6 +688,7 @@ class _IRBuilder(object):
 
         buffer_source_types = set([
             'ArrayBuffer',
+            'ArrayBufferView',  # Blink-specific ArrayBufferView definition
             'DataView',
             'Int8Array',
             'Int16Array',

third_party/blink/renderer/bindings/scripts/web_idl/migration_adapter.idl

@@ -24,8 +24,3 @@ typedef SpeechRecognition SpeechRecognitionConstructor;
 typedef SpeechRecognitionErrorEvent SpeechRecognitionErrorEventConstructor;
 typedef SpeechRecognitionEvent SpeechRecognitionEventConstructor;
 typedef URL URLConstructor;
-
-// https://heycam.github.io/webidl/#ArrayBufferView
-typedef (Int8Array or Int16Array or Int32Array or
-         Uint8Array or Uint16Array or Uint32Array or Uint8ClampedArray or
-         Float32Array or Float64Array or DataView) ArrayBufferView;

third_party/blink/renderer/bindings/scripts/web_idl/union.py

@@ -87,8 +87,7 @@ class Union(WithIdentifier, WithCodeGeneratorInfo, WithComponent,
         # type_names = sorted(
         #     [idl_type.type_name for idl_type in flattened_members])
         type_names = [
-            idl_type.type_name for idl_type in union_types[0].
-            flattened_member_types_in_original_order
+            idl_type.type_name for idl_type in union_types[0].member_types
         ]
         if does_include_nullable_type:
             type_names.append('Null')