IDL: Clean up argument conversion error handling

Source/bindings/scripts/v8_methods.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
@@ skipping 34 matching lines @@
 # Methods with any of these require custom method registration code in the
 # interface's configure*Template() function.
 CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES = frozenset([
     'DoNotCheckSecurity',
     'DoNotCheckSignature',
     'NotEnumerable',
     'Unforgeable',
 ])
 
 
-def argument_needs_try_catch(method, argument):
-    idl_type = argument.idl_type
-    base_type = idl_type.base_type
-
-    return not(
-        # These cases are handled by separate code paths in the
-        # generate_argument() macro in Source/bindings/templates/methods.cpp.
-        idl_type.is_callback_interface or
-        base_type == 'SerializedScriptValue' or
-        (argument.is_variadic and idl_type.is_wrapper_type) or
-        # Variadic arguments use toImplArguments() with throws excentions via
-        # its ExceptionState& argument.
-        argument.is_variadic or
-        # String and enumeration arguments converted using one of the
-        # TOSTRING_* macros except for _PROMISE variants in
-        # Source/bindings/core/v8/V8BindingMacros.h don't use a v8::TryCatch.
-        ((base_type == 'DOMString' or idl_type.is_enum) and
-         not method.returns_promise) or
-        # Conversion that take an ExceptionState& argument throw all their
-        # exceptions via it, and doesn't need/use a TryCatch, except if the
-        # argument has [Clamp], in which case it uses a separate code path in
-        # Source/bindings/templates/methods.cpp, which *does* use a TryCatch.
-        argument_conversion_needs_exception_state(method, argument) or
-        # A trivial conversion cannot throw exceptions at all, so doesn't need a
-        # TryCatch to catch them.
-        idl_type.v8_conversion_is_trivial)
-
-
 def use_local_result(method):
     extended_attributes = method.extended_attributes
     idl_type = method.idl_type
     return (has_extended_attribute_value(method, 'CallWith', 'ScriptState') or
             'ImplementedInPrivateScript' in extended_attributes or
             'RaisesException' in extended_attributes or
             idl_type.is_union_type or
             idl_type.is_explicit_nullable)
 
 
@@ skipping 42 matching lines @@
     is_check_security_for_frame = (
         has_extended_attribute_value(interface, 'CheckSecurity', 'Frame') and
         not is_do_not_check_security)
 
     is_check_security_for_window = (
         has_extended_attribute_value(interface, 'CheckSecurity', 'Window') and
         not is_do_not_check_security)
 
     is_raises_exception = 'RaisesException' in extended_attributes
 
-    arguments_need_try_catch = (
-        any(argument_needs_try_catch(method, argument)
-            for argument in arguments))
-
     return {
         'activity_logging_world_list': v8_utilities.activity_logging_world_list(method),  # [ActivityLogging]
         'arguments': [argument_context(interface, method, argument, index)
                       for index, argument in enumerate(arguments)],
         'argument_declarations_for_private_script':
             argument_declarations_for_private_script(interface, method),
-        'arguments_need_try_catch': arguments_need_try_catch,
         'conditional_string': v8_utilities.conditional_string(method),
         'cpp_type': (v8_types.cpp_template_type('Nullable', idl_type.cpp_type)
                      if idl_type.is_explicit_nullable else idl_type.cpp_type),
         'cpp_value': this_cpp_value,
         'cpp_type_initializer': idl_type.cpp_type_initializer,
         'custom_registration_extended_attributes':
             CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES.intersection(
                 extended_attributes.iterkeys()),
         'deprecate_as': v8_utilities.deprecate_as(method),  # [DeprecateAs]
         'exposed_test': v8_utilities.exposed(method, interface),  # [Exposed]
@@ skipping 308 matching lines @@
 
 IdlOperation.returns_promise = property(method_returns_promise)
 
 
 def argument_conversion_needs_exception_state(method, argument):
     idl_type = argument.idl_type
     return (idl_type.v8_conversion_needs_exception_state or
             argument.is_variadic or
             (method.returns_promise and (idl_type.is_string_type or
                                          idl_type.is_enum)))