IDL: restructure logic handling registration of methods

Source/bindings/scripts/v8_interface.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 # coding=utf-8
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 232 matching lines @@
         'has_constructor_attributes': any(attribute['constructor_type'] for attribute in attributes),
         'has_per_context_enabled_attributes': any(attribute['per_context_enabled_function'] for attribute in attributes),
         'has_replaceable_attributes': any(attribute['is_replaceable'] for attribute in attributes),
     })
 
     # Methods
     methods = [v8_methods.generate_method(interface, method)
                for method in interface.operations
                if method.name]  # Skip anonymous special operations (methods)
     generate_method_overloads(methods)
+
+    per_context_enabled_methods = []
+    custom_registration_methods = []
+    method_configuration_methods = []
+
     for method in methods:
-        method['do_generate_method_configuration'] = (
-            method['do_not_check_signature'] and
-            not method['per_context_enabled_function'] and
-            # For overloaded methods, only generate one accessor
-            ('overload_index' not in method or method['overload_index'] == 1))
+        # Skip all but one method in each set of overloaded methods.
+        if 'overload_index' in method and 'overloads' not in method:
+            continue
 
+        if 'overloads' in method:
+            overloads = method['overloads']
+            per_context_enabled_function = overloads['per_context_enabled_function_all']
+            runtime_enabled_function = overloads['runtime_enabled_function_all']
+            has_custom_registration = overloads['has_custom_registration_all']
+        else:
+            per_context_enabled_function = method['per_context_enabled_function']
+            runtime_enabled_function = method['runtime_enabled_function']
+            has_custom_registration = method['has_custom_registration']
+
+        if per_context_enabled_function:
+            per_context_enabled_methods.append(method)
+            continue
+        if runtime_enabled_function or has_custom_registration:
+            custom_registration_methods.append(method)
+            continue
+        method_configuration_methods.append(method)
+
+    for method in methods:
         # The value of the Function object’s “length” property is a Number
         # determined as follows:
         # 1. Let S be the effective overload set for regular operations (if the
         # operation is a regular operation) or for static operations (if the
         # operation is a static operation) with identifier id on interface I and
         # with argument count 0.
         # 2. Return the length of the shortest argument list of the entries in S.
         # FIXME: This calculation doesn't take into account whether runtime
         # enabled overloads are actually enabled, so length may be incorrect.
         # E.g., [RuntimeEnabled=Foo] void f(); void f(long x);
         # should have length 1 if Foo is not enabled, but length 0 if it is.
         method['length'] = (method['overloads']['minarg'] if 'overloads' in method else
                             method['number_of_required_arguments'])
 
     template_contents.update({
+        'custom_registration_methods': custom_registration_methods,
         'has_origin_safe_method_setter': any(
             method['is_check_security_for_frame'] and not method['is_read_only']
             for method in methods),
-        'has_method_configuration': any(method['do_generate_method_configuration'] for method in methods),
-        'has_per_context_enabled_methods': any(method['per_context_enabled_function'] for method in methods),
+        'method_configuration_methods': method_configuration_methods,
+        'per_context_enabled_methods': per_context_enabled_methods,
         'methods': methods,
     })
 
     template_contents.update({
         'indexed_property_getter': indexed_property_getter(interface),
         'indexed_property_setter': indexed_property_setter(interface),
         'indexed_property_deleter': indexed_property_deleter(interface),
         'is_override_builtins': 'OverrideBuiltins' in extended_attributes,
         'named_property_getter': named_property_getter(interface),
         'named_property_setter': named_property_setter(interface),
@@ skipping 73 matching lines @@
 
     Sets |method.overload_index| in place for |method| in |overloads|
     and returns dict of overall overload template values.
     """
     assert len(overloads) > 1  # only apply to overloaded names
     for index, method in enumerate(overloads, 1):
         method['overload_index'] = index
 
     effective_overloads_by_length = effective_overload_set_by_length(overloads)
     lengths = [length for length, _ in effective_overloads_by_length]
+    name = overloads[0].get('name', '<constructor>')
 
     # Check and fail if all overloads with the shortest acceptable arguments
     # list are runtime enabled, since we would otherwise set 'length' on the
     # function object to an incorrect value when none of those overloads were
     # actually enabled at runtime. The exception is if all overloads are
     # controlled by the same runtime enabled feature, in which case there would
     # be no function object at all if it is not enabled.
     shortest_overloads = effective_overloads_by_length[0][1]
     if (all(method.get('runtime_enabled_function')
             for method, _, _ in shortest_overloads) and
         not common_value(overloads, 'runtime_enabled_function')):
-        raise ValueError('Function.length of %s depends on runtime enabled features' % overloads[0]['name'])
+        raise ValueError('Function.length of %s depends on runtime enabled features' % name)
+
+    # Check and fail if overloads disagree on any of the extended attributes
+    # that affect how the method should be registered.
+    # Skip the check for overloaded constructors, since they don't support any
+    # of the extended attributes in question.
+    if not overloads[0].get('is_constructor'):
+        overload_extended_attributes = [
+            method['custom_registration_extended_attributes']
+            for method in overloads]
+        for extended_attribute in v8_methods.CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES:
+            if common_key(overload_extended_attributes, extended_attribute) is None:
+                raise ValueError('Overloads of %s have conflicting extended attribute %s'
+                                 % (name, extended_attribute))
 
     return {
         'deprecate_all_as': common_value(overloads, 'deprecate_as'),  # [DeprecateAs]
         'length_tests_methods': length_tests_methods(effective_overloads_by_length),
         'minarg': lengths[0],
         # 1. Let maxarg be the length of the longest type list of the
         # entries in S.
         'maxarg': lengths[-1],
         'measure_all_as': common_value(overloads, 'measure_as'),  # [MeasureAs]
+        'has_custom_registration_all': common_value(overloads, 'has_custom_registration'),
+        'per_context_enabled_function_all': common_value(overloads, 'per_context_enabled_function'),  # [PerContextEnabled]
+        'runtime_enabled_function_all': common_value(overloads, 'runtime_enabled_function'),  # [RuntimeEnabled]
         'valid_arities': lengths
             # Only need to report valid arities if there is a gap in the
             # sequence of possible lengths, otherwise invalid length means
             # "not enough arguments".
             if lengths[-1] - lengths[0] != len(lengths) - 1 else None,
     }
 
 
 def effective_overload_set(F):
     """Returns the effective overload set of an overloaded function.
@@ skipping 340 matching lines @@
 ################################################################################
 
 def Counter(iterable):
     # Once using Python 2.7, using collections.Counter
     counter = defaultdict(lambda: 0)
     for item in iterable:
         counter[item] += 1
     return counter
 
 
+def common(dicts, f):
+    """Returns common result of f across an iterable of dicts, or None.
+
+    Call f for each dict and return its result if the same across all dicts.
+    """
+    values = (f(d) for d in dicts)
+    first_value = next(values)
+    if all(value == first_value for value in values):
+        return first_value
+    return None
+
+
+def common_key(dicts, key):
+    """Returns common presence of a key across an iterable of dicts, or None.
+
+    True if all dicts have the key, False if none of the dicts have the key,
+    and None if some but not all dicts have the key.
+    """
+    return common(dicts, lambda d: key in d)
+
+
 def common_value(dicts, key):
     """Returns common value of a key across an iterable of dicts, or None.
 
     Auxiliary function for overloads, so can consolidate an extended attribute
     that appears with the same value on all items in an overload set.
     """
-    values = (d.get(key) for d in dicts)
-    first_value = next(values)
-    if all(value == first_value for value in values):
-        return first_value
-    return None
+    return common(dicts, lambda d: d.get(key))
 
 
 def sort_and_groupby(l, key=None):
     """Returns a generator of (key, list), sorting and grouping list by key."""
     l.sort(key=key)
     return ((k, list(g)) for k, g in itertools.groupby(l, key))
 
 
 ################################################################################
 # Constructors
@@ skipping 258 matching lines @@
         deleter = next(
             method
             for method in interface.operations
             if ('deleter' in method.specials and
                 len(method.arguments) == 1 and
                 str(method.arguments[0].idl_type) == 'DOMString'))
     except StopIteration:
         return None
 
     return property_deleter(deleter)