bindings: Introduces on_{instance,prototype,interface} in the code generator.

Source/bindings/scripts/v8_utilities.py

Index: Source/bindings/scripts/v8_utilities.py
diff --git a/Source/bindings/scripts/v8_utilities.py b/Source/bindings/scripts/v8_utilities.py
index 9a9d6cdfb648936184a498df772537a967898fd2..1816207c2ec037163982efc49f1f188e8f000ab4 100644
--- a/Source/bindings/scripts/v8_utilities.py
+++ b/Source/bindings/scripts/v8_utilities.py
@@ -225,6 +225,12 @@ def conditional_string(definition_or_member):
     return 'ENABLE(%s)' % extended_attributes['Conditional']
 
 
+# [Constructor], [NamedConstructor]
+def is_constructor_attribute(member):
+    # TODO: replace this with [Constructor] and [NamedConstructor] extended attribute

[haraken, 2015/06/17 16:31:21]

TODO(yukishiino)

[Yuki, 2015/06/18 07:44:41]

Done.

+    return member.idl_type.name.endswith('Constructor')
+
+
 # [DeprecateAs]
 def deprecate_as(member):
     extended_attributes = member.extended_attributes
@@ -404,6 +410,58 @@ def is_legacy_interface_type_checking(interface, member):
         return True
     return False
 
+
+# [Unforgeable], [OverrideBuiltins], [Global], [PrimaryGlobal] and [ExposeJSAccessors] / [DoNotExposeJSAccessors]

[haraken, 2015/06/17 16:31:21]

This comment is a bit confusing.

- You have the same comment on on_instance, on_prototype and on_interface.

- You say "[ExposeJSAccessors] / [DoNotExposeJSAccessors]", but the former
should exist on prototype whereas the latter should exist on instance.

[bashi, 2015/06/18 02:16:27]

I'd recommend to have docstring to describe how this method (and other on_xxx
methods) is used.

[Yuki, 2015/06/18 07:44:40]

Done.

[Yuki, 2015/06/18 07:44:40]

Done.

+def on_instance(interface, member):
+    return not on_prototype(interface, member)
+
+
+# [Unforgeable], [OverrideBuiltins], [Global], [PrimaryGlobal] and [ExposeJSAccessors] / [DoNotExposeJSAccessors]
+def on_prototype(interface, member):
+    if ('ExposeJSAccessors' in interface.extended_attributes and
+            'DoNotExposeJSAccessors' in interface.extended_attributes):
+        raise Exception('Both of ExposeJSAccessors and DoNotExposeJSAccessors are specified at a time in an interface: ' + interface.name)
+    if ('ExposeJSAccessors' in member.extended_attributes and
+            'DoNotExposeJSAccessors' in member.extended_attributes):
+        raise Exception('Both of ExposeJSAccessors and DoNotExposeJSAccessors are specified at a time on a member: ' + member.name + ' in an interface: ' + interface.name)
+
+    # Note that ExposeJSAccessors and DoNotExposeJSAccessors are more powerful
+    # than 'static', [Unforgeable] and [OverrideBuiltins].
+    if 'ExposeJSAccessors' in member.extended_attributes:
+        return True
+    if 'DoNotExposeJSAccessors' in member.extended_attributes:
+        return False
+
+    # These members must not be placed on prototype chains.
+    if (is_constructor_attribute(member) or
+            member.is_static or
+            is_unforgeable(interface, member) or
+            'OverrideBuiltins' in interface.extended_attributes):
+        return False
+
+    # TODO(yukishiino): We should handle [Global] and [PrimaryGlobal] instead of
+    # Window.
+    if (interface.name == 'Window'):
+        return member.idl_type.name == 'EventHandler'
+
+    # TODO(yukishiino): We should move all of the following members to prototype
+    # chains.
+    if ('Custom' in member.extended_attributes):

[bashi, 2015/06/18 02:16:27]

nit: drop parenthesis.

[Yuki, 2015/06/18 07:44:40]

Done.

+        return False
+
+    if 'ExposeJSAccessors' in interface.extended_attributes:
+        return True
+    if 'DoNotExposeJSAccessors' in interface.extended_attributes:
+        return False

[haraken, 2015/06/17 16:31:21]

It's a bit confusing that the priority of [ExposeJSAccessors] is different
between [ExposeJSAccessors] on members and [ExposeJSAccessors] on interfaces.

BTW, is there any [ExposeJSAccessors] used on interfaces?

(If you have a plan to remove [ExposeJSAccessors] in the near future, I'm OK
with the current code though.)

[Yuki, 2015/06/18 07:44:41]

Well, however, we should not place static members on the prototype object even
if [ExposeJSAccessors] is specified for an interface.  [ExposeJSAccessors] on
interfaces means that "regular members" will be placed on the prototype object. 
We need to check if the member is a regular member or not before applying the
interface-wide default setting.
No, there is no effective ones.
Optimistically, we can get rid of [ExposeJSAccessors] in a month or two, I
think.

+
+    return True
+
+
+# [Unforgeable], [OverrideBuiltins], [Global], [PrimaryGlobal] and [ExposeJSAccessors] / [DoNotExposeJSAccessors]
+def on_interface(interface, member):
+    return False

[haraken, 2015/06/17 16:31:21]

Just help me understand: When should on_interface return True?

[Yuki, 2015/06/18 07:44:41]

constants and static members must be defined on the interface object.

I'm planning to handle them here.

+
+
 ################################################################################
 # Indexed properties
 # http://heycam.github.io/webidl/#idl-indexed-properties