WIP IDL compiler rewrite

Source/bindings/scripts/code_generator_v8.py

+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Library General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Library General Public License for more details.
+#
+# You should have received a copy of the GNU Library General Public License
+# along with this library; see the file COPYING.LIB.  If not, write to
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+#
+
+
+import os
+import os.path
+import sys
+import json
+import re
+
+import generate_bindings
+
+import pprint
+pp = pprint.PrettyPrinter(indent=2, width=80)
+
+
+_current_dir = os.path.dirname(os.path.realpath(__file__))
+# jinja2 is in chromium's third_party directory
+sys.path.append(os.path.join(_current_dir, *([os.pardir] * 4)))
+import jinja2
+
+
+### basic utility
+
+def pathsplit(path):
+    dirs = []
+    while True:
+        (dirname, basename) = os.path.split(path)
+        if basename=="":
+            break
+        dirs.append(basename)
+        path = dirname
+    dirs.reverse()
+    return dirs
+
+def abs2rel(path, basedir):
+    path_dirs = pathsplit(os.path.abspath(path))
+    basedir_dirs = pathsplit(os.path.abspath(basedir))
+    common_dirs = 0
+    for i in range(min(len(path_dirs), len(basedir_dirs))):
+        if path_dirs[i] != basedir_dirs[i]:
+            break
+        common_dirs += 1
+    relpath = []
+    for i in range(len(basedir_dirs)-common_dirs):
+        relpath.append("..")
+    relpath.extend(path_dirs[common_dirs:])
+    return os.sep.join(relpath)
+
+def get_path(dic, keys):
+    node = dic
+    for key in keys:
+        if key not in node:
+            return None
+        node = node[key]
+    return node
+
+def apply_template(path_to_template, params):
+    dirname, basename = os.path.split(path_to_template)
+    path_to_templates = os.path.join(_current_dir, "templates")
+    jinja_env = jinja2.Environment(loader=jinja2.FileSystemLoader([dirname, path_to_templates]))
+    template = jinja_env.get_template(basename)
+    return template.render(params)
+
+
+
+### subroutine for code generator
+
+def create_arguments(arguments):
+    return ", ".join([argument for argument in arguments if argument])
+
+def get_v8_class_name(interface):
+    return "V8" + interface.name
+
+def get_impl_name(interface):
+    implementedAs = interface.extended_attributes.get("ImplementedAs")
+    if implementedAs is not None:
+        return implementedAs
+    return interface.name
+
+def get_conditional_string(interface_or_attribute_or_operation):
+    conditional = interface_or_attribute_or_operation.extended_attributes.get("Conditional");
+    if conditional is None:
+        return ""
+    else:
+        operator = ""
+        if "&" in operator:
+            operator = "&"
+        if "|" in operator:
+            operator = "|"
+        if operator == "":
+            return "ENABLE(%s)" % conditional;
+        else:
+            # Avoid duplicated conditions.
+            conditions = dict([(expression, True) for expression in conditional.split(operator)])
+            return (operator + operator).join(["ENABLE(%s)" % expression for expression in sorted(conditions.keys())])
+
+def get_includes_for_type(type):
+    if skip_include_header(type):
+        return []
+
+    # Default includes
+    includes = []
+    if type == "EventListener":
+        includes.append("core/dom/EventListener.h")
+    elif type == "SerializedScriptValue":
+        includes.append("bindings/v8/SerializedScriptValue.h")
+    elif type == "any" or is_callback_function_type(type):
+        includes.append("bindings/v8/ScriptValue.h")
+    else:
+        includes.append("V8%s.h" % type)
+
+    # Additional includes
+    if type == "CSSStyleSheet":
+        includes.append("core/css/CSSImportRule.h")
+
+    if not is_dom_node_type(type):
+        includes.append("wtf/RefCounted.h")
+        includes.append("wtf/RefPtr.h")
+        includes.append("wtf/GetPtr.h")
+
+    print "[get_includes_for_type]", pp.pformat(includes)
+    return includes
+
+def get_includes_for_parameter(parameter):
+    includes = []
+    array_or_sequence_type = get_array_type(parameter.data_type) or get_sequence_type(parameter.data_type)
+    if array_or_sequence_type:
+        if is_ref_ptr_type(array_or_sequence_type):
+            includes += get_includes_for_type(array_or_sequence_type)
+    else:
+        includes += get_includes_for_type(parameter.data_type)
+    return includes
+
+
+def get_includes_for_operation(operation):
+    includes = get_includes_for_type(operation.data_type)
+    for parameter in operation.parameters:
+        includes += get_includes_for_parameter(parameter)
+    return includes
+
+def link_overloaded_functions(interface):
+    name_to_operations = {}
+    for operation in interface.functions:
+        name = operation.name
+        if not name:
+            operation.overloads = []
+            operation.overload_index = 0
+            continue
+        if name not in name_to_operations:
+            name_to_operations[name] = []
+        name_to_operations[name].append(operation)
+        operation.overloads = name_to_operations[name]
+        operation.overload_index = len(name_to_operations[name])
+
+def apply_conditional(operation_or_attribute, code):
+    conditional_string = get_conditional_string(operation_or_attribute)
+    if conditional_string:
+        wrapped_code  = "#if %s\n" % conditional_string
+        wrapped_code += code
+        wrapped_code += "#endif // %s\n" % conditional_string
+        return wrapped_code
+    else:
+        return code
+
+def get_namespace_for_interface(interface):
+    if is_typed_array_type(interface.name):
+        return "WTF"
+    return "WebCore"
+
+
+### Types
+
+# IDL type: [element's C++ type, V8 type]
+typed_arrays = {
+    "ArrayBuffer": [],
+    "ArrayBufferView": [],
+    "Uint8Array": ["unsigned char", "v8::kExternalUnsignedByteArray"],
+    "Uint8ClampedArray": ["unsigned char", "v8::kExternalPixelArray"],
+    "Uint16Array": ["unsigned short", "v8::kExternalUnsignedShortArray"],
+    "Uint32Array": ["unsigned int", "v8::kExternalUnsignedIntArray"],
+    "Int8Array": ["signed char", "v8::kExternalByteArray"],
+    "Int16Array": ["short", "v8::kExternalShortArray"],
+    "Int32Array": ["int", "v8::kExternalIntArray"],
+    "Float32Array": ["float", "v8::kExternalFloatArray"],
+    "Float64Array": ["double", "v8::kExternalDoubleArray"],
+}
+
+primitive_types = {
+    "boolean": True,
+    "void": True,
+    "Date": True,
+    "byte": True,
+    "octet": True,
+    "short": True,
+    "long": True,
+    "long long": True,
+    "unsigned short": True,
+    "unsigned long": True,
+    "unsigned long long": True,
+    "float": True,
+    "double": True,
+}
+
+enum_types = {
+}
+
+callback_function_types = {
+}
+
+non_wrapper_types = {
+    "CompareHow": True,
+    "DOMTimeStamp": True,
+    "Dictionary": True,
+    "EventListener": True,
+    # FIXME: When EventTarget is an interface and not a mixin, fix this so that
+    # EventTarget is treated as a wrapper type.
+    "EventTarget": True,
+    "MediaQueryListListener": True,
+    "NodeFilter": True,
+    "SerializedScriptValue": True,
+    "any": True,
+}
+
+dom_node_types = {
+    "Attr": True,
+    "CDATASection": True,
+    "CharacterData": True,
+    "Comment": True,
+    "Document": True,
+    "DocumentFragment": True,
+    "DocumentType": True,
+    "Element": True,
+    "Entity": True,
+    "HTMLDocument": True,
+    "Node": True,
+    "Notation": True,
+    "ProcessingInstruction": True,
+    "ShadowRoot": True,
+    "SVGDocument": True,
+    "Text": True,
+    "TestNode": True,
+}
+
+def get_sequence_type(type):
+    matched = re.match("^sequence<([\w\d_\s]+)>.*", type)
+    if matched:
+        return matched.group(1)
+    return "";
+
+def get_array_type(type):
+    matched = re.match("^([\w\d_\s]+)\[\]", type)
+    if matched:
+        return matched.group(1)
+    return "";
+
+def is_wrapper_type(type):
+    if get_array_type(type):
+        return False
+    if get_sequence_type(type):
+        return False
+    if is_callback_function_type(type):
+        return False
+    if is_enum_type(type):
+        return False
+    if is_primitive_type(type):
+        return False
+    if type == "DOMString":
+        return False
+    return not non_wrapper_types.get(type);
+
+def is_typed_array_type(type):
+    return type in typed_arrays
+
+def is_primitive_type(type):
+    if type in primitive_types:
+        return True
+    return False
+
+def is_enum_type(type):
+    if type in enum_types:
+        return True
+    return False
+
+def is_callback_function_type(type):
+    if type in callback_function_types:
+        return True
+    return False
+
+def is_dom_node_type(type):
+    if type in dom_node_types:
+        return True
+    if re.match("/^HTML.*Element$/", type):
+        return True
+    if re.match("/^SVG.*Element$/", type):
+        return True
+    return False
+
+def skip_include_header(type):
+    if is_primitive_type(type):
+        return True
+    if is_enum_type(type):
+        return True
+    if is_callback_function_type(type):
+        return True
+    if type=="DOMString":
+        return True
+    return False
+
+def is_constructable(interface):
+    for name in ["CustomConstructor", "Constructor", "ConstructorTemplate"]:
+        if name in interface.extended_attributes:
+            return True
+    return False
+
+
+def has_custom_getter(extended_attributes):
+    return "Custom" in extended_attributes or "CustomGetter" in extended_attributes
+
+def has_custom_setter(extended_attributes):
+    return "Custom" in extended_attributes or "CustomSetter" in extended_attributes
+
+def has_custom_method(extended_attributes):
+    return "Custom" in extended_attributes
+
+def is_constructor_template(interface, template_name):
+    return interface.extended_attributes.get("ConstructorTemplate")==template_name
+
+def needs_opaque_root_for_gc(interface):
+    for name in ["GenerateIsReachable", "CustomIsReachable"]:
+        if name in interface.extended_attributes:
+            return True
+    return False
+
+# URL becomes url, but SetURL becomes setURL.
+def to_method_name(name):
+    new_name  = name[0].lower() + name[1:]
+    for keyword in ["HTML", "URL", "JS", "XML", "XSLT", "CSS", ]:
+        keyword_lcfirst = keyword[0].lower() + name[1:]
+        new_name = re.sub("/^"+keyword_lcfirst+"/", keyword, new_name)
+
+    # For HTML5 FileSystem API Flags attributes.
+    # (create is widely used to instantiate an object and must be avoided.)
+    new_name = re.sub("/^create$/", "isCreate", new_name)
+    new_name = re.sub("/^exclusive$/", "isExclusive", new_name)
+    
+    return new_name
+
+# Returns the RuntimeEnabledFeatures function name that is hooked up to check if a method/attribute is enabled.
+def get_runtime_enable_function_name(interface_or_attribute_or_function):
+    # If a parameter is given (e.g. "EnabledAtRuntime=FeatureName") return the RuntimeEnabledFeatures::{FeatureName}Enabled() method.
+    enabled_at_runtime = interface_or_attribute_or_function.extended_attributes.get("EnabledAtRuntime")
+    if enabled_at_runtime:
+        return "RuntimeEnabledFeatures::%sEnabled" % to_method_name(enabled_at_runtime)
+
+    # Otherwise return a function named RuntimeEnabledFeatures::{methodName}Enabled().
+    return "RuntimeEnabledFeatures::%sEnabled" % to_method_name(interface_or_attribute_or_function.name)
+
+def requires_custom_signature(function):
+    # No signature needed for Custom function
+    if has_custom_method(function.extended_attributes):
+        return False
+    # No signature needed for overloaded function
+    if len(function.overloads) > 1:
+        return False
+    if function.is_static:
+        return False
+    # Type checking is performed in the generated code
+    if function.extended_attributes.get("StrictTypeChecking"):
+        return False
+    for parameter in function.parameters:
+        if parameter.is_optional and not parameter.extended_attributes.get("Default") or is_callback_interface(parameter.type):
+            return False
+
+    for parameter in function.parameters:
+        if is_wrapper_type(parameter.type):
+            return True
+    return False
+
+def is_standard_function(interface, function):
+    for key in ["Unforgeable", "EnabledAtRuntime", "EnabledPerContext", "DoNotCheckSignature", "NotEnumerable", "ReadOnly"]:
+        if function.extended_attributes.get(key):
+            return False
+    if function.is_static:
+        return False
+    if requires_custom_signature(function):
+        return False
+    if function.extended_attributes.get("DoNotCheckSecurity") and interface.extended_attributes.get("CheckSecurity") or interface.name == "Window":
+        return False
+    return True
+
+
+
+###
+
+
+### main
+class code_generator_v8:
+    def __init__(self, document, idl_directories, dependent_idl_files, options):
+        self.document = document
+        self.dependent_idl_files = dependent_idl_files
+        self.idl_directories = idl_directories
+        self.idl_files = {}
+        self.options = options
+        self.header = ""
+        self.implementation = ""
+        self.cached_interfaces = {}
+        
+        enum_types = dict([ [enum["name"], enum["values"]] for enum in self.document.enumerations ])
+#         print "enum_types", pp.pformat(enum_types)
+        callback_function_types = dict([ [enum["name"], enum] for enum in self.document.callback_functions ])
+        self.prepare_idl_files()
+
+    def prepare_idl_files(self):
+        directories = [ os.getcwd() + os.sep + directory for directory in self.idl_directories ]
+        directories = filter(lambda path: os.path.isdir(path), directories)
+        directories.append(".")
+#         print "[prepare_idl_files] directories", directories
+        for idl_file in self.dependent_idl_files:
+            basename, ext = os.path.splitext(os.path.basename(idl_file))
+            self.idl_files[basename] = idl_file
+    #     print("[idl_files]", idl_files)
+        for directory in directories:
+            for root, dirs, files in os.walk(directory):
+                for file in files:
+                    basename, ext = os.path.splitext(file)
+                    if ext==".idl":
+                        fullpath = root + os.sep + file
+                        self.idl_files[basename] = fullpath
+#         for key, value in enumerate(self.idl_files):
+#             print("[idl_files]", key, value)
+
+    def idl_file_for_interface(self, interface_name):
+    #     print "[idl_file_for_interface]", interface_name, len(idl_files)
+    #     print("[idl_files]", idl_files)
+        return self.idl_files.get(interface_name)
+
+    def parse_interface(self, interface_name):
+        if interface_name in self.cached_interfaces:
+            self.cached_interfaces[interface_name]
+    
+        # Step #1: Find the IDL file associated with 'interface'
+        filename = self.idl_file_for_interface(interface_name)
+        if filename is None:
+            raise Exception("Could NOT find IDL file for interface \"%s\"" % interface_name);
+    
+        if self.options.verbose:
+            print "  |  |>  Parsing parent IDL \"%s\" for interface \"%s\"" % (filename, interface_name)
+    
+        # Step #2: Parse the found IDL file (in quiet mode).
+        document = generate_bindings.read_pickled_idl(interface_name)
+        for interface in document.interfaces:
+            if interface.name == interface_name or interface.is_partial:
+                self.cached_interfaces[interface_name] = interface
+                return interface
+
+        raise Exception("Could NOT find interface definition for %s in %s" % (interface_name, filename));
+
+    def for_all_parents(self, interface):
+        for direct_parent_interface_name in interface.parents:
+            direct_parent_interface = self.parse_interface(direct_parent_interface_name)
+            yield direct_parent_interface
+            for parent_interface in self.for_all_parents(direct_parent_interface):
+                yield parent_interface
+
+    def inherits_interface(self, interface, interface_name):
+        if interface.name == interface_name:
+            return True
+        for parent_interface in self.for_all_parents(self.interface):
+            if parent_interface.name == interface_name:
+                return True
+        return False
+
+    def interface_inherits_extended_attribute(self, interface, extended_attribute):
+        if extended_attribute in interface.extended_attributes:
+            return True
+        for parent_interface in self.for_all_parents(interface):
+            if extended_attribute in parent_interface.extended_attributes:
+                return True
+        return False
+
+
+    def get_parameter_declaration(self, operation):
+        parameters = [ "%s %s" % (self.get_native_type(parameter.data_type, used_as_parameter=True, called_by_webcore=True), parameter.name) for parameter in operation.parameters ]
+        return ", ".join(parameters)
+
+    def get_native_to_js_value(self, type, extended_attributes, native_value, indent, receiver, creation_context, \
+                               isolate, holder_container="", script_wrappable="", return_handle_type="", for_main_world_suffix="", return_value_arg=""):
+        """
+        Create statement which convert native(C++) value into JS value.
+
+        @param[in] type
+        @param[in] extended_attributes
+        @param[in] native_value
+        @param[in] indent
+        @param[in] receiver              must contain one "%s". to return something: v8SetReturnValue(<holder_container>, %s);
+        @param[in] creation_context
+        @param[in] isolate
+        @param[in] holder_container
+        @param[in] script_wrappable
+        @param[in] return_handle_type
+        @param[in] for_main_world_suffix
+        @param[in] return_value_arg
+        """
+        def create_statement(js_value):
+            return indent + receiver % js_value
+
+        if not isolate:
+            raise Exception("An Isolate is mandatory for native value => JS value conversion.")
+
+        # long long and unsigned long long are not representable in ECMAScript.
+        if type == "long long" or type == "unsigned long long" or type == "DOMTimeStamp":
+            return create_statement("v8::Number::New(static_cast<double>(%s))" % native_value)
+
+        if is_primitive_type(type):
+            if not (type=="float" or type=="double"):
+                raise Exception("unexpected type %s" % type)
+            return create_statement("v8::Number::New(%s)" % native_value)
+
+        if type=="DOMString" or is_enum_type(type):
+            conversion = extended_attributes.get("TreatReturnedNullStringAs")
+            js_value = ""
+            arguments = create_arguments([native_value, isolate, return_handle_type])
+            if conversion is None:
+                js_value = "v8String(%s)" % arguments
+            elif conversion == "Null":
+                js_value = "v8StringOrNull(%s)" % arguments
+            elif conversion == "Undefined":
+                js_value = "v8StringOrUndefined(%s)" % arguments
+            else:
+                raise Exception("Unknown value for TreatReturnedNullStringAs extended attribute")
+
+            # FIXME: Use safe handles
+            return create_statement(js_value)
+
+        # FIXME: Use safe handles
+        return create_statement("toV8(%s, %s, %s)" % (native_value, creation_context, isolate))
+
+    def get_native_type(self, type, called_by_webcore=False, used_as_parameter=False):
+        """
+        Return native type corresponds to IDL type.
+        @param[in] type
+        @param[in] called_by_webcore
+        @param[in] used_as_parameter
+        """
+        print "[get_native_type]", type
+        if type=="float":
+            return "float"
+        if type=="double":
+            return "double"
+        if type=="int" or type=="long" or type=="short" or type=="byte":
+            return "int"
+        if type=="unsigned long" or type=="unsigned int" or type=="unsigned short" or type=="octet":
+            return "unsigned"
+        if type=="long long":
+            return "long long"
+        if type=="unsigned long long":
+            return "unsigned long long"
+        if type=="boolean":
+            return "bool"
+        if type=="DOMString":
+            if used_as_parameter:
+                if called_by_webcore:
+                    return "const String&"
+                else:
+                    return "V8StringResource"
+            return "String"
+        # We need to check [ImplementedAs] extended attribute for wrapper types.
+        if is_wrapper_type(type):
+            interface = self.parse_interface(type)
+            type = get_impl_name(interface)
+
+        if used_as_parameter:
+            if called_by_webcore:
+                return type + "*"
+            else:
+                return "PassRefPtr<%s>" % type
+        else:
+            return "RefPtr<%s>" % type
+
+
+    def header_files_for_interface(self, interface_name, impl_class_name):
+#         print "[header_files_for_interface]", interface_name, impl_class_name
+        includes = []
+        if is_typed_array_type(interface_name):
+            includes.append("wtf/%s.h" % interface_name)
+        elif not skip_include_header(interface_name):
+            idl_filename = self.idl_file_for_interface(interface_name)
+            assert idl_filename
+            idlRelPath = "bindings/" + abs2rel(idl_filename, os.getcwd())
+#             print "idlRelPath", idl_filename, idlRelPath, os.getcwd()
+            includes.append(os.path.dirname(idlRelPath) + os.sep + impl_class_name + ".h")
+        print "[header_files_for_interface] result", pp.pformat(includes)
+        return includes
+
+    def generate_interface(self, interface):
+        self.interface = interface
+
+        self.common_template_parameters = {
+            "conditional_if": "",
+            "conditional_endif": "",
+        }
+        conditional_string = get_conditional_string(self.interface)
+        if conditional_string != "":
+            self.common_template_parameters["conditional_if"] = "#if " + conditional_string
+            self.common_template_parameters["conditional_endif"] = "#endif // " + conditional_string
+
+        if self.options.no_h is None:
+            if interface.is_callback:
+                self.generate_callback_header()
+            else:
+                self.generate_header()
+
+        if self.options.no_cpp is None:
+            if interface.is_callback:
+                self.generate_callback_implementation()
+            else:
+                self.generate_implementation()
+
+    def write_interfaces(self):
+        for interface in self.document.interfaces:
+            self.generate_interface(interface)
+            self.write_data()
+
+    def write_data(self):
+        """
+        options.output_directory
+        options.output_headers_directory
+        """
+#         print self.header
+        if self.options.no_h is None:
+            header_filename = self.options.output_headers_directory + os.sep + get_v8_class_name(self.interface) + ".h"
+            with open(header_filename, "w") as f:
+                f.write(self.header)
+
+        if self.options.no_cpp is None:
+            implementation_filename = self.options.output_directory + os.sep + get_v8_class_name(self.interface) + ".cpp"
+            with open(implementation_filename, "w") as f:
+                f.write(self.implementation)
+
+
+
+    def generate_to_v8_converters(self, interface, v8_class_name, impl_class_name_as_parameter):
+        includes = []
+        code = ""
+        if interface.extended_attributes.get("DoNotGenerateWrap") or interface.extended_attributes.get("DoNotGenerateToV8"):
+            return includes, code
+        includes.append("bindings/v8/ScriptController.h")
+        includes.append("core/page/Frame.h")
+        # TODO.....
+        return includes, code
+
+
+    def generate_callback_header(self):
+        impl_class_name = get_impl_name(self.interface);
+        v8_class_name = get_v8_class_name(self.interface);
+
+        template_parameters = self.common_template_parameters.copy()
+        template_parameters.update({
+            "interface_name": self.interface.name,
+            "impl_class_name": impl_class_name,
+            "v8_class_name": v8_class_name,
+            "includes": [
+                "bindings/v8/ActiveDOMCallback.h",
+                "bindings/v8/DOMWrapperWorld.h",
+                "bindings/v8/ScopedPersistent.h",
+            ],
+            "class_public_definitions": [],
+        })
+        template_parameters["includes"].extend(self.header_files_for_interface(self.interface.name, impl_class_name))
+        template_parameters["includes"].sort()
+        for operation in self.interface.functions:
+            code = "virtual %s %s(%s);" % (self.get_native_type(operation.data_type), operation.name, self.get_parameter_declaration(operation))
+            template_parameters["class_public_definitions"].append(code)
+
+        self.header = apply_template("scripts/callbackHeader.template", template_parameters)
+
+    def generate_callback_implementation(self):
+#         pp.pprint(self.interface)
+        impl_class_name = get_impl_name(self.interface);
+        v8_class_name = get_v8_class_name(self.interface);
+
+        template_parameters = self.common_template_parameters.copy()
+        template_parameters.update({
+            "interface_name": self.interface.name,
+            "impl_class_name": impl_class_name,
+            "v8_class_name": v8_class_name,
+            "main_includes": [
+                v8_class_name+".h",
+            ],
+            "sub_includes": [
+                "core/dom/ScriptExecutionContext.h",
+                "bindings/v8/V8Binding.h",
+                "bindings/v8/V8Callback.h",
+                "wtf/Assertions.h",
+            ],
+            "class_public_definitions": [],
+            "web_core_definitions": [],
+        })
+
+        template_parameters["interface_name"] = self.interface.name
+
+        for operation in self.interface.functions:
+            code = {}
+            if "Custom" in operation.extended_attributes:
+                continue
+            template_parameters["sub_includes"] += get_includes_for_operation(operation)
+            if operation.data_type != "boolean":
+                raise Exception("We don't yet support callbacks that return non-boolean values.")
+            code["signature"] = "%s %s::%s(%s)" % (self.get_native_type(operation.data_type), v8_class_name, operation.name, self.get_parameter_declaration(operation))
+
+            prepare_parameter_statements = []
+            code["prepare_js_parameters"] = ""
+            for parameter in operation.parameters:
+                receiver = "v8::Handle<v8::Value> %sHandle = %%s;" % parameter.name
+                subcode  = self.get_native_to_js_value(parameter.data_type, parameter.extended_attributes, parameter.name, "", receiver, "v8::Handle<v8::Object>()", "isolate", "") + "\n"
+                subcode += "if (%sHandle.IsEmpty()) {\n" % parameter.name
+                subcode += "    if (!isScriptControllerTerminating())\n"
+                subcode += "        CRASH();\n"
+                subcode += "    return true;\n"
+                subcode += "}\n"
+                code["prepare_js_parameters"] += subcode
+                prepare_parameter_statements.append("    %sHandle" % parameter.name)
+
+            if len(prepare_parameter_statements) > 0:
+                subcode  = "v8::Handle<v8::Value> argv[] = {\n";
+                subcode += ",\n".join(prepare_parameter_statements)
+                subcode += "\n};";
+                code["prepare_js_parameters"] += subcode
+            else:
+                code["prepare_js_parameters"] += "v8::Handle<v8::Value> *argv = 0;"
+
+            code["number_of_parameters"] = len(operation.parameters)
+            template_parameters["web_core_definitions"].append(code)
+
+        template_parameters["sub_includes"] = list(set(template_parameters["sub_includes"]))
+        template_parameters["sub_includes"].sort()
+        self.implementation = apply_template("scripts/callbackImplementation.template", template_parameters)
+
+    def get_internal_fields(self):
+        custom_internal_fields = []
+        # Event listeners on DOM nodes are explicitly supported in the GC controller.
+        if not self.inherits_interface(self.interface, "Node") and self.interface_inherits_extended_attribute(self.interface, "EventTarget"):
+            custom_internal_fields.append("eventListenerCacheIndex")
+        return custom_internal_fields
+
+    def generate_header_custom_internal_field_indices(self):
+        custom_internal_fields = self.get_internal_fields()
+        codes = []
+        custom_field_counter = 0
+        for custom_internal_field in custom_internal_fields:
+            codes.append("static const int %s = v8DefaultWrapperInternalFieldCount + %d;" % (custom_internal_field, custom_field_counter))
+            custom_field_counter += 1
+        codes.append("static const int internalFieldCount = v8DefaultWrapperInternalFieldCount + %d;" % custom_field_counter)
+        return codes
+
+    def generate_header(self):
+        impl_class_name = get_impl_name(self.interface);
+        v8_class_name = get_v8_class_name(self.interface);
+
+        template_parameters = self.common_template_parameters.copy()
+        template_parameters.update({
+            "interface_name": self.interface.name,
+            "impl_class_name": impl_class_name,
+            "v8_class_name": v8_class_name,
+            "impl_class_name_as_parameter": self.get_native_type(self.interface.name, used_as_parameter=True),
+            "is_constructor_template_of_event": is_constructor_template(self.interface, "Event"),
+            "needs_opaque_root_for_gc": needs_opaque_root_for_gc(self.interface),
+            "inherits_extended_attribute_active_dom_object": self.interface_inherits_extended_attribute(self.interface, "ActiveDOMObject"),
+            "inherits_extended_attribute_event_target": self.interface_inherits_extended_attribute(self.interface, "EventTarget"),
+            "is_constructable": is_constructable(self.interface),
+            "custom_internal_field_indices": self.generate_header_custom_internal_field_indices(),
+            "includes": [
+                "bindings/v8/WrapperTypeInfo.h",
+                "bindings/v8/V8Binding.h",
+                "bindings/v8/V8DOMWrapper.h",
+            ],
+            "operation_definitions": [],
+            "attribute_definitions": [],
+        })
+
+        link_overloaded_functions(self.interface);
+
+        # Ensure the IsDOMNodeType function is in sync.
+        if is_dom_node_type(self.interface.name) != self.inherits_interface(self.interface, "Node"):
+            inh = self.inherits_interface(self.interface, "Node") and "INHERIT" or ""
+            dom = is_dom_node_type(self.interface.name) and "DOM" or ""
+            print "[IsDOMNodeType]", dom, inh
+            raise Exception("IsDOMNodeType is out of date with respect to %s" % self.interface.name)
+
+        print "Parents", pp.pformat(self.interface.parents)
+        for parent_interface_name in self.interface.parents:
+#             print "ADD H", parent_interface_name
+            template_parameters["includes"].append("V8%s.h" % parent_interface_name)
+
+        # TODO Window
+
+        enabled_per_context_functions = [ operation for operation in self.interface.functions if operation.name and operation.extended_attributes.get("EnabledPerContext") ]
+        enabled_per_context_attributes = [ attribute for attribute in self.interface.attributes if attribute.extended_attributes.get("EnabledPerContext") ]
+
+        for operation in self.interface.functions:
+            if not operation.name:
+                continue
+            if has_custom_method(operation.extended_attributes) and operation.overload_index==1:
+                code = "static void %sMethodCustom(const v8::FunctionCallbackInfo<v8::Value>&);" % operation.name
+                template_parameters["operation_definitions"].append(apply_conditional(operation, code))
+
+        for attribute in self.interface.attributes:
+            if has_custom_getter(attribute.extended_attributes):
+                code = "static void %sAttrGetterCustom(v8::Local<v8::String> name, const v8::PropertyCallbackInfo<v8::Value>&);" % attribute.name
+                template_parameters["attribute_definitions"].append(apply_conditional(attribute, code))
+            if has_custom_setter(attribute.extended_attributes):
+                code = "static void %sAttrSetterCustom(v8::Local<v8::String> name, v8::Local<v8::Value>, const v8::PropertyCallbackInfo<void>&);" % attribute.name
+                template_parameters["attribute_definitions"].append(apply_conditional(attribute, code))
+
+
+
+
+
+
+
+        # TODO HasCustomConstructor
+
+        # TODO GenerateHeaderNamedAndIndexedPropertyAccessors
+        # TODO GenerateHeaderLegacyCall
+
+        # TODO Window
+
+        template_parameters["install_per_context_properties_body"] = len(enabled_per_context_attributes) > 0 and ";" or " { }"
+        template_parameters["install_per_context_prototype_properties_body"] = len(enabled_per_context_functions) > 0 and ";" or " { }"
+
+        # TODO HTMLElement
+        # TODO SVGElement
+        # TODO HTMLUnknownElement
+        # TODO Element
+
+        no_to_v8 = "DoNotGenerateToV8" in self.interface.extended_attributes
+        no_wrap = "DoNotGenerateWrap" in self.interface.extended_attributes or no_to_v8
+        template_parameters["wrap"] = not no_wrap
+        template_parameters["custom_wrap"] = custom_wrap = "CustomToV8" in self.interface.extended_attributes
+        if no_to_v8:
+            if len(list(self.for_all_parents(self.interface))) > 0:
+                raise Exception("Can't suppress toV8 for subclass")
+        elif no_wrap:
+            if not custom_wrap:
+                raise Exception("Must have custom toV8")
+            template_parameters["generate_to_v8"] = True
+        
+        template_parameters["includes"].extend(self.header_files_for_interface(self.interface.name, impl_class_name))
+        template_parameters["includes"] = list(set(template_parameters["includes"]))
+        template_parameters["includes"].sort()
+
+        self.header = apply_template("scripts/header.template", template_parameters)
+
+    # __IMPL__
+    def generate_implementation(self):
+        impl_class_name = get_impl_name(self.interface);
+        v8_class_name = get_v8_class_name(self.interface);
+
+        normal_functions = []
+        enabled_per_context_functions = []
+        for operation in self.interface.functions:
+            if operation.name=="":
+                continue
+            if operation.extended_attributes.get("EnabledPerContext"):
+                enabled_per_context_functions.append(operation)
+            else:
+                normal_functions.append(operation)
+        has_callbacks = False
+        for operation in normal_functions:
+            # Only one table entry is needed for overloaded methods:
+            if operation.overload_index > 1:
+                continue
+            # Don't put any nonstandard functions into this table:
+            if not is_standard_function(self.interface, operation):
+                continue
+            has_callbacks = True
+
+
+
+        inherits_extended_attribute_active_dom_object = self.interface_inherits_extended_attribute(self.interface, "ActiveDOMObject")
+        inherits_extended_attribute_event_target = self.interface_inherits_extended_attribute(self.interface, "EventTarget")
+        has_attributes = len(self.interface.attributes) > 0
+        impl_class_name_as_parameter = self.get_native_type(self.interface.name, used_as_parameter=True)
+
+        template_parameters = self.common_template_parameters.copy()
+        template_parameters.update({
+            "interface_name": self.interface.name,
+            "impl_class_name": impl_class_name,
+            "v8_class_name": v8_class_name,
+            "impl_class_name_as_parameter": impl_class_name_as_parameter,
+            "is_constructor_template_of_event": is_constructor_template(self.interface, "Event"),
+            "needs_opaque_root_for_gc": needs_opaque_root_for_gc(self.interface),
+            "inherits_extended_attribute_active_dom_object": inherits_extended_attribute_active_dom_object,
+            "inherits_extended_attribute_event_target": inherits_extended_attribute_event_target,
+            "is_constructable": is_constructable(self.interface),
+            "custom_internal_field_indices": self.generate_header_custom_internal_field_indices(),
+            "namespace_for_interface": get_namespace_for_interface(self.interface),
+            "wrapper_type_prototype": self.interface.is_exception and "WrapperTypeErrorPrototype" or "WrapperTypeObjectPrototype",
+            "enabled_at_runtime": "EnabledAtRuntime" in self.interface.extended_attributes,
+            "enable_function": get_runtime_enable_function_name(self.interface),
+            "configure_template_batched_attribute": has_attributes and v8_class_name + "Attrs" or "0",
+            "configure_template_attribute_count": has_attributes and "WTF_ARRAY_LENGTH(%sAttrs)" % v8_class_name or "0",
+            "configure_template_batched_method": has_callbacks and v8_class_name + "Methods" or "0",
+            "configure_template_method_count": has_callbacks and "WTF_ARRAY_LENGTH(%sMethods)" % v8_class_name or "0",
+            "includes": [
+                "bindings/v8/V8Binding.h",
+                "bindings/v8/V8DOMWrapper.h",
+                "core/dom/ContextFeatures.h",
+                "core/dom/Document.h",
+                "RuntimeEnabledFeatures.h",
+                "wtf/UnusedParam.h",
+            ],
+            "operation_definitions": [],
+            "attribute_definitions": [],
+        })
+        template_parameters["to_active_dom_object"] = inherits_extended_attribute_active_dom_object and v8_class_name + "::toActiveDOMObject" or "0"
+        template_parameters["to_event_target"] = inherits_extended_attribute_event_target and v8_class_name + "::toEventTarget" or "0"
+        template_parameters["root_for_gc"] = needs_opaque_root_for_gc(self.interface) and v8_class_name + "::opaqueRootForGC" or "0"
+
+        self.generate_to_v8_converters(self.interface, v8_class_name, impl_class_name_as_parameter)
+
+        template_parameters["includes"] += get_includes_for_type(self.interface.name)
+
+        parent_class_name = ""
+        parent_class_template = ""
+        if len(self.interface.parents) > 0:
+            parent_interface_name = self.interface.parents[0]
+            parent_class_name = "V8" + parent_interface_name
+            print "ADD H", parent_interface_name
+            template_parameters["includes"].append("V8%s.h" % parent_interface_name)
+            parent_class_template = parent_class_name + "::GetTemplate(isolate, currentWorldType)"
+
+        template_parameters["parent_class_info"] = parent_class_info = parent_class_name and "&%s::info" % parent_class_name or "0"
+        template_parameters["parent_class_template"] = parent_class_template
+
+        template_parameters["includes"] = filter(lambda include: include != v8_class_name+".h", list(set(template_parameters["includes"])))
+        template_parameters["includes"].sort()
+        self.implementation = apply_template("scripts/implementation.template", template_parameters)
+
+
+
+if __name__ == '__main__':
+    # HTMLTitleElement
+    doc = json.loads("""
+    {"idlDocument::callbackFunctions":[],"idlDocument::enumerations":[],"idlDocument::fileName":"/mnt/hdd/chromium/src/third_party/WebKit/Source/core/html/HTMLTitleElement.idl","idlDocument::interfaces":[{"domInterface::attributes":[{"domAttribute::extendedAttributes":{"TreatNullAs":"NullString"},"domAttribute::getterExceptions":[],"domAttribute::isNullable":null,"domAttribute::isReadOnly":null,"domAttribute::isStatic":null,"domAttribute::name":"text","domAttribute::setterExceptions":[],"domAttribute::type":"DOMString"}],"domInterface::constants":[],"domInterface::constructors":[],"domInterface::customConstructors":[],"domInterface::extendedAttributes":{},"domInterface::isCallback":null,"domInterface::isException":null,"domInterface::isPartial":null,"domInterface::name":"HTMLTitleElement","domInterface::operations":[],"domInterface::parents":["HTMLElement"]}]}
+    """)
+    # print("HTMLTitleElement")
+    # pp.pprint(doc)
+    
+    # VoidCallback
+    doc = json.loads("""
+    {"idlDocument::callbackFunctions":[],"idlDocument::enumerations":[],"idlDocument::fileName":"/mnt/hdd/chromium/src/third_party/WebKit/Source/core/html/VoidCallback.idl","idlDocument::interfaces":[{"domInterface::attributes":[],"domInterface::constants":[],"domInterface::constructors":[],"domInterface::customConstructors":[],"domInterface::extendedAttributes":{},"domInterface::functions":[{"domFunction::extendedAttributes":{},"domFunction::isStatic":null,"domFunction::name":"handleEvent","domFunction::overloadedIndex":null,"domFunction::parameters":[],"domFunction::specials":[],"domFunction::type":"boolean"}],"domInterface::isCallback":1,"domInterface::isException":null,"domInterface::isPartial":null,"domInterface::name":"VoidCallback","domInterface::parents":[]}]}
+    """)
+    # print("VoidCallback")
+    # pp.pprint(doc)
+    
+    cg = code_generator_v8(doc, ["../modules"], ["/mnt/hdd/chromium/src/third_party/WebKit/Source/core/html/VoidCallback.idl"])
+    for interface in doc["idlDocument::interfaces"]:
+        cg.generate_interface(interface)
+        cg.write_data()
+    
+    
+    def test_abs2rel(a, b, ref):
+        result = abs2rel(a, b)
+        assert result==ref, "abs2rel(%s, %s) should be %s but actually %s" % (a, b, ref, result)
+    
+    test_abs2rel("./a/b/c", ".", "a/b/c")
+    test_abs2rel("/a/b/c", "/a/b/d", "../c")
+
+
+
+