Generate simple code for "trivial" conversions

Source/bindings/scripts/v8_types.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 463 matching lines @@
 
 
 def v8_conversion_needs_exception_state(idl_type):
     return (idl_type.is_numeric_type or
             idl_type.is_dictionary or
             idl_type.name in ('ByteString', 'ScalarValueString'))
 
 IdlType.v8_conversion_needs_exception_state = property(v8_conversion_needs_exception_state)
 
 
+def v8_conversion_is_trivial(idl_type):
+    # The conversion is a simple expression that returns the converted value and
+    # cannot raise an exception.
+    return (idl_type.base_type == 'boolean' or
+            idl_type.is_wrapper_type)
+
+IdlType.v8_conversion_is_trivial = property(v8_conversion_is_trivial)
+
+
 def v8_value_to_cpp_value(idl_type, extended_attributes, v8_value, index, isolate):
     if idl_type.name == 'void':
         return ''
 
     # Array or sequence types
     native_array_element_type = idl_type.native_array_element_type
     if native_array_element_type:
         return v8_value_to_cpp_value_array_or_sequence(native_array_element_type, v8_value, index)
 
     # Simple types
@@ skipping 56 matching lines @@
     this_cpp_type = idl_type.cpp_type_args(extended_attributes=extended_attributes, raw_type=True)
 
     idl_type = idl_type.preprocessed_type
     cpp_value = v8_value_to_cpp_value(idl_type, extended_attributes, v8_value, index, isolate)
     args = [variable_name, cpp_value]
     if idl_type.base_type == 'DOMString':
         macro = 'TOSTRING_DEFAULT' if used_in_private_script else 'TOSTRING_VOID'
     elif idl_type.v8_conversion_needs_exception_state:
         macro = 'TONATIVE_DEFAULT_EXCEPTIONSTATE' if used_in_private_script else 'TONATIVE_VOID_EXCEPTIONSTATE'
         args.append('exceptionState')
+    elif idl_type.v8_conversion_is_trivial:
+        assignment = '%s = %s' % (variable_name, cpp_value)
+        if declare_variable:
+            return '%s %s' % (this_cpp_type, assignment)
+        return assignment
     else:
         macro = 'TONATIVE_DEFAULT' if used_in_private_script else 'TONATIVE_VOID'
 
     if used_in_private_script:
         args.append('false')
 
     # Macros come in several variants, to minimize expensive creation of
     # v8::TryCatch.
     suffix = ''
 
@@ skipping 253 matching lines @@
 
 
 def is_explicit_nullable(idl_type):
     # Nullable type that isn't implicit nullable (see above.) For such types,
     # we use Nullable<T> or similar explicit ways to represent a null value.
     return idl_type.is_nullable and not idl_type.is_implicit_nullable
 
 IdlTypeBase.is_implicit_nullable = property(is_implicit_nullable)
 IdlUnionType.is_implicit_nullable = False
 IdlTypeBase.is_explicit_nullable = property(is_explicit_nullable)