IDL parser rewrite in Python

Source/bindings/scripts/idl_definitions_builder.py

+# Copyright (C) 2013 Google Inc. All rights reserved.
+#
+# 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
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Builds an IdlDefinitions object from an AST (produced by blink_idl_parser)."""
+
+from idl_definitions import IdlDefinitions, IdlInterface, IdlException, IdlOperation, IdlCallbackFunction, IdlArgument, IdlAttribute, IdlConstant, IdlEnum, IdlTypedef, IdlUnionType
+
+SPECIAL_KEYWORD_LIST = ['GETTER', 'SETTER', 'DELETER']
+
+
+def build_idl_definitions_from_ast(node):
+    if node is None:
+        return None
+    node_class = node.GetClass()
+    if node_class != 'File':
+        raise ValueError('Unrecognized node class: %s' % node_class)
+    return file_node_to_idl_definitions(node)
+
+
+def file_node_to_idl_definitions(node):
+    callback_functions = {}
+    enumerations = {}
+    exceptions = {}
+    file_name = node.GetName()  # FIXME: only needed for Perl, remove later
+    interfaces = {}
+    typedefs = {}
+
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Interface':
+            interface = interface_node_to_idl_interface(child)
+            interfaces[interface.name] = interface
+        elif child_class == 'Exception':
+            exception = exception_node_to_idl_exception(child)
+            exceptions[exception.name] = exception
+        elif child_class == 'Typedef':
+            type_name = child.GetName()
+            typedefs[type_name] = typedef_node_to_idl_typedef(child)
+        elif child_class == 'Enum':
+            enumeration = enum_node_to_idl_enum(child)
+            enumerations[enumeration.name] = enumeration
+        elif child_class == 'Callback':
+            callback_function = callback_node_to_idl_callback_function(child)
+            callback_functions[callback_function.name] = callback_function
+        elif child_class == 'Implements':
+            # Implements is handled at the interface merging step
+            pass
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlDefinitions(callback_functions=callback_functions, enumerations=enumerations, exceptions=exceptions, file_name=file_name, interfaces=interfaces, typedefs=typedefs)
+
+# Constructors for Interface definitions and interface members
+
+
+def interface_node_to_idl_interface(node):
+    attributes = []
+    constants = []
+    constructors = None
+    custom_constructors = None
+    extended_attributes = None
+    operations = []
+    is_callback = node.GetProperty('CALLBACK') or False
+    # FIXME: uppercase 'Partial' in base IDL parser
+    is_partial = node.GetProperty('Partial') or False
+    name = node.GetName()
+    parent = None
+
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Attribute':
+            attribute = attribute_node_to_idl_attribute(child)
+            # FIXME: This is a hack to support [CustomConstructor] for
+            # window.HTMLImageElement. Remove the hack.
+            clear_constructor_attributes(attribute.extended_attributes)
+            attributes.append(attribute)
+        elif child_class == 'Const':
+            constants.append(constant_node_to_idl_constant(child))
+        elif child_class == 'ExtAttributes':
+            extended_attributes = ext_attributes_node_to_extended_attributes(child)
+            constructors, custom_constructors = extended_attributes_to_constructors(extended_attributes)
+            clear_constructor_attributes(extended_attributes)
+        elif child_class == 'Operation':
+            operations.append(operation_node_to_idl_operation(child))
+        elif child_class == 'Inherit':
+            parent = child.GetName()
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlInterface(name=name, attributes=attributes, constants=constants, constructors=constructors, custom_constructors=custom_constructors, extended_attributes=extended_attributes, operations=operations, is_callback=is_callback, is_partial=is_partial, parent=parent)
+
+
+def attribute_node_to_idl_attribute(node):
+    data_type = None
+    extended_attributes = {}
+    is_nullable = False
+    is_read_only = node.GetProperty('READONLY') or False
+    is_static = node.GetProperty('STATIC') or False
+    name = node.GetName()
+
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Type':
+            data_type = type_node_to_type(child)
+            is_nullable = child.GetProperty('NULLABLE') or False
+        elif child_class == 'ExtAttributes':
+            extended_attributes = ext_attributes_node_to_extended_attributes(child)
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlAttribute(data_type=data_type, extended_attributes=extended_attributes, is_nullable=is_nullable, is_read_only=is_read_only, is_static=is_static, name=name)
+
+
+def constant_node_to_idl_constant(node):
+    name = node.GetName()
+
+    children = node.GetChildren()
+    num_children = len(children)
+    if num_children < 2 or num_children > 3:
+        raise ValueError('Expected 2 or 3 children, got %s' % num_children)
+
+    type_node = children[0]
+    # ConstType is more limited than Type, so subtree is smaller and we don't
+    # use the full type_node_to_type function.
+    data_type = type_node_inner_to_type(type_node)
+
+    value_node = children[1]
+    value_node_class = value_node.GetClass()
+    if value_node_class != 'Value':
+        raise ValueError('Expected Value node, got %s' % value_node_class)
+    value = value_node.GetName()
+
+    extended_attributes = None
+    if num_children == 3:
+        ext_attributes_node = children[2]
+        extended_attributes = ext_attributes_node_to_extended_attributes(ext_attributes_node)
+
+    return IdlConstant(data_type=data_type, extended_attributes=extended_attributes, name=name, value=value)
+
+
+def operation_node_to_idl_operation(node):
+    name = node.GetName()
+    # FIXME: AST should use None internally
+    if name == '_unnamed_':
+        name = None
+
+    is_static = node.GetProperty('STATIC') or False
+    specials = []
+    property_dictionary = node.GetProperties()
+    for special_keyword in SPECIAL_KEYWORD_LIST:
+        if special_keyword in property_dictionary:
+            specials.append(special_keyword.lower())
+
+    extended_attributes = None
+    arguments = []
+    return_type = None
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Arguments':
+            arguments = arguments_node_to_arguments(child)
+        elif child_class == 'Type':
+            return_type = type_node_to_type(child)
+        elif child_class == 'ExtAttributes':
+            extended_attributes = ext_attributes_node_to_extended_attributes(child)
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlOperation(name=name, data_type=return_type, extended_attributes=extended_attributes, is_static=is_static, arguments=arguments, specials=specials)
+
+
+def arguments_node_to_arguments(node):
+    # [Constructor] and [CustomConstructor] without arguments (the bare form)
+    # have None instead of an arguments node, but have the same meaning as using
+    # an empty argument list, [Constructor()], so special-case this.
+    # http://www.w3.org/TR/WebIDL/#Constructor
+    if node is None:
+        return []
+    arguments = []
+    argument_node_list = node.GetChildren()
+    for argument_node in argument_node_list:
+        arguments.append(argument_node_to_idl_argument(argument_node))
+    return arguments
+
+
+def argument_node_to_idl_argument(node):
+    name = node.GetName()
+
+    data_type = None
+    extended_attributes = {}
+    # FIXME: Boolean values are inconsistent due to Perl compatibility.
+    # Make all default to False once Perl removed.
+    is_nullable = False
+    is_optional = node.GetProperty('OPTIONAL')
+    is_variadic = None
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Type':
+            data_type = type_node_to_type(child)
+            is_nullable = child.GetProperty('NULLABLE')
+        elif child_class == 'ExtAttributes':
+            extended_attributes = ext_attributes_node_to_extended_attributes(child)
+        elif child_class == 'Argument':
+            child_name = child.GetName()
+            if child_name != '...':
+                raise ValueError('Unrecognized Argument node; expected "...", got "%s"' % child_name)
+            is_variadic = child.GetProperty('ELLIPSIS') or False
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlArgument(name=name, data_type=data_type, extended_attributes=extended_attributes, is_nullable=is_nullable, is_optional=is_optional, is_variadic=is_variadic)
+
+# Constructors for for non-interface definitions
+
+
+def callback_node_to_idl_callback_function(node):
+    name = node.GetName()
+    children = node.GetChildren()
+    num_children = len(children)
+    if num_children != 2:
+        raise ValueError('Expected 2 children, got %s' % num_children)
+
+    type_node = children[0]
+    data_type = type_node_to_type(type_node)
+
+    arguments_node = children[1]
+    arguments_node_class = arguments_node.GetClass()
+    if arguments_node_class != 'Arguments':
+        raise ValueError('Expected Value node, got %s' % arguments_node_class)
+    arguments = arguments_node_to_arguments(arguments_node)
+
+    return IdlCallbackFunction(name=name, data_type=data_type, arguments=arguments)
+
+
+def enum_node_to_idl_enum(node):
+    name = node.GetName()
+    values = []
+    for child in node.GetChildren():
+        values.append(child.GetName())
+    return IdlEnum(name=name, values=values)
+
+
+def exception_operation_node_to_idl_operation(node):
+    # Needed to handle one case in DOMException.idl:
+    # // Override in a Mozilla compatible format
+    # [NotEnumerable] DOMString toString();
+    # FIXME: can we remove this? replace with a stringifier?
+    extended_attributes = {}
+    name = node.GetName()
+    children = node.GetChildren()
+    if len(children) < 1 or len(children) > 2:
+        raise ValueError('ExceptionOperation node with %s children, expected 1 or 2' % len(children))
+
+    type_node = children[0]
+    return_type = type_node_to_type(type_node)
+
+    if len(children) > 1:
+        ext_attributes_node = children[1]
+        extended_attributes = ext_attributes_node_to_extended_attributes(ext_attributes_node)
+
+    return IdlOperation(name=name, data_type=return_type, extended_attributes=extended_attributes)
+
+
+def exception_node_to_idl_exception(node):
+    # Exceptions are similar to Interfaces, but simpler
+    attributes = []
+    constants = []
+    extended_attributes = None
+    operations = []
+    name = node.GetName()
+
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Attribute':
+            attribute = attribute_node_to_idl_attribute(child)
+            attributes.append(attribute)
+        elif child_class == 'Const':
+            constants.append(constant_node_to_idl_constant(child))
+        elif child_class == 'ExtAttributes':
+            extended_attributes = ext_attributes_node_to_extended_attributes(child)
+        elif child_class == 'ExceptionOperation':
+            operations.append(exception_operation_node_to_idl_operation(child))
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlException(name=name, attributes=attributes, constants=constants, extended_attributes=extended_attributes, operations=operations)
+
+
+def typedef_node_to_idl_typedef(node):
+    data_type = None
+    extended_attributes = None
+
+    children = node.GetChildren()
+    for child in children:
+        child_class = child.GetClass()
+        if child_class == 'Type':
+            data_type = type_node_to_type(child)
+        elif child_class == 'ExtAttributes':
+            extended_attributes = ext_attributes_node_to_extended_attributes(child)
+            raise ValueError('Extended attributes in a typedef are untested!')
+        else:
+            raise ValueError('Unrecognized node class: %s' % child_class)
+
+    return IdlTypedef(data_type=data_type, extended_attributes=extended_attributes)
+
+# Extended attributes
+
+
+def ext_attributes_node_to_extended_attributes(node):
+    """
+    Returns:
+      Dictionary of {ExtAttributeName: ExtAttributeValue}.
+      Value is usually a string, with three exceptions:
+      Constructors: value is a list of Arguments nodes, corresponding to
+      possibly signatures of the constructor.
+      CustomConstructors: value is a list of Arguments nodes, corresponding to
+      possibly signatures of the custom constructor.
+      NamedConstructor: value is a Call node, corresponding to the single
+      signature of the named constructor.
+    """
+    # Primarily just make a dictionary from the children.
+    # The only complexity is handling various types of constructors:
+    # Constructors and Custom Constructors can have duplicate entries due to
+    # overloading, and thus are stored in temporary lists.
+    # However, Named Constructors cannot be overloaded, and thus do not have
+    # a list.
+    # FIXME: Add overloading for Named Constructors and remove custom bindings
+    # for HTMLImageElement
+    constructors = []
+    custom_constructors = []
+    extended_attributes = {}
+
+    attribute_list = node.GetChildren()
+    for attribute in attribute_list:
+        name = attribute.GetName()
+        children = attribute.GetChildren()
+        if name in ['Constructor', 'CustomConstructor', 'NamedConstructor']:
+            child = None
+            child_class = None
+            if children:
+                if len(children) > 1:
+                    raise ValueError('ExtAttributes node with %s children, expected at most 1' % len(children))
+                child = children[0]
+                child_class = child.GetClass()
+            if name == 'Constructor':
+                if child_class and child_class != 'Arguments':
+                    raise ValueError('Constructor only supports Arguments as child, but has child of class: %s' % child_class)
+                constructors.append(child)
+            elif name == 'CustomConstructor':
+                if child_class and child_class != 'Arguments':
+                    raise ValueError('Custom Constructor only supports Arguments as child, but has child of class: %s' % child_class)
+                custom_constructors.append(child)
+            else:  # name == 'NamedConstructor'
+                if child_class and child_class != 'Call':
+                    raise ValueError('Named Constructor only supports Call as child, but has child of class: %s' % child_class)
+                extended_attributes[name] = child
+        elif children:
+            raise ValueError('Non-constructor ExtAttributes node with children: %s' % name)
+        else:
+            value = attribute.GetProperty('VALUE')
+            extended_attributes[name] = value
+
+    # Store constructors and custom constructors in special list attributes,
+    # which are deleted later. Note plural in key.
+    if constructors:
+        extended_attributes['Constructors'] = constructors
+    if custom_constructors:
+        extended_attributes['CustomConstructors'] = custom_constructors
+
+    return extended_attributes
+
+
+def extended_attributes_to_constructors(extended_attributes):
+    """Returns constructors and custom_constructors (lists of IdlOperations).
+
+    Auxiliary function for interface_node_to_idl_interface.
+    """
+    constructors = []
+    custom_constructors = []
+    if 'Constructors' in extended_attributes:
+        constructor_list = extended_attributes['Constructors']
+        # If not overloaded, have index 0, otherwise index from 1
+        overloaded_index = 0 if len(constructor_list) == 1 else 1
+        for arguments_node in constructor_list:
+            name = 'Constructor'
+            arguments = arguments_node_to_arguments(arguments_node)
+            constructor = IdlOperation(name=name, extended_attributes=extended_attributes, overloaded_index=overloaded_index, arguments=arguments)
+            constructors.append(constructor)
+            overloaded_index += 1
+
+        # Prefix 'CallWith' and 'RaisesException' with 'Constructor'
+        # FIXME: Change extended attributes to include prefix explicitly.
+        if 'CallWith' in extended_attributes:
+            extended_attributes['ConstructorCallWith'] = extended_attributes['CallWith']
+            del extended_attributes['CallWith']
+        if 'RaisesException' in extended_attributes:
+            extended_attributes['ConstructorRaisesException'] = extended_attributes['RaisesException']
+            del extended_attributes['RaisesException']
+
+    if 'CustomConstructors' in extended_attributes:
+        custom_constructor_list = extended_attributes['CustomConstructors']
+        # If not overloaded, have index 0, otherwise index from 1
+        overloaded_index = 0 if len(custom_constructor_list) == 1 else 1
+        for arguments_node in custom_constructor_list:
+            name = 'CustomConstructor'
+            arguments = arguments_node_to_arguments(arguments_node)
+            custom_constructor = IdlOperation(name=name, extended_attributes=extended_attributes, overloaded_index=overloaded_index, arguments=arguments)
+            custom_constructors.append(custom_constructor)
+            overloaded_index += 1
+
+    if 'NamedConstructor' in extended_attributes:
+        name = 'NamedConstructor'
+        call_node = extended_attributes['NamedConstructor']
+        extended_attributes['NamedConstructor'] = call_node.GetName()
+        overloaded_index = None  # named constructors are not overloaded
+        children = call_node.GetChildren()
+        if len(children) != 1:
+            raise ValueError('NamedConstructor node expects 1 child, got %s.' % len(children))
+        arguments_node = children[0]
+        arguments = arguments_node_to_arguments(arguments_node)
+        named_constructor = IdlOperation(name=name, extended_attributes=extended_attributes, overloaded_index=overloaded_index, arguments=arguments)
+        constructors.append(named_constructor)
+
+    return constructors, custom_constructors
+
+
+def clear_constructor_attributes(extended_attributes):
+    # Deletes Constructor*s* (plural), sets Constructor (singular)
+    if 'Constructors' in extended_attributes:
+        del extended_attributes['Constructors']
+        extended_attributes['Constructor'] = None
+    if 'CustomConstructors' in extended_attributes:
+        del extended_attributes['CustomConstructors']
+        extended_attributes['CustomConstructor'] = None
+
+
+# Types
+
+
+def type_node_to_type(node):
+    children = node.GetChildren()
+    if len(children) < 1 or len(children) > 2:
+        raise ValueError('Type node expects 1 or 2 children (type + optional array []), got %s (multi-dimensional arrays are not supported).' % len(children))
+
+    type_node_child = children[0]
+    data_type = type_node_inner_to_type(type_node_child)
+
+    if len(children) == 2:
+        array_node = children[1]
+        array_node_class = array_node.GetClass()
+        if array_node_class != 'Array':
+            raise ValueError('Expected Array node as TypeSuffix, got %s node.' % array_node_class)
+        data_type += '[]'
+
+    return data_type
+
+
+def type_node_inner_to_type(node):
+    node_class = node.GetClass()
+    # FIXME: Typedef is misspelled as Type*r*ef in base parser.
+    if node_class in ['PrimitiveType', 'Typeref']:
+        return node.GetName()
+    elif node_class == 'Any':
+        return 'any'
+    elif node_class == 'Sequence':
+        return sequence_node_to_type(node)
+    elif node_class == 'UnionType':
+        return union_type_node_to_idl_union_type(node)
+    raise ValueError('Unrecognized node class: %s' % node_class)
+
+
+def sequence_node_to_type(node):
+    children = node.GetChildren()
+    if len(children) != 1:
+        raise ValueError('Sequence node expects exactly 1 child, got %s' % len(children))
+    sequence_child = children[0]
+    sequence_child_class = sequence_child.GetClass()
+    if sequence_child_class != 'Type':
+        raise ValueError('Unrecognized node class: %s' % sequence_child_class)
+    sequence_type = type_node_to_type(sequence_child)
+    return 'sequence<%s>' % sequence_type
+
+
+def union_type_node_to_idl_union_type(node):
+    union_member_types = []
+    for member_type_node in node.GetChildren():
+        member_type = type_node_to_type(member_type_node)
+        union_member_types.append(member_type)
+    return IdlUnionType(union_member_types=union_member_types)