Bindings generation emits (more) correct null checking

Source/bindings/dart/scripts/dart_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 381 matching lines @@
     # FIXME(vsm): Why don't we have an entry for Window? V8 does.
     # I think I removed this as the Window object is more special in V8 - it's the
     # global context as well.  Do we need to special case it?
     'XPathNSResolver': 'nullptr /* FIXME, DART_TO_CPP_VALUE[XPathNSResolver] */',
     # FIXME(vsm): This is an enum type (defined in StorageQuota.idl).
     # We should handle it automatically, but map to a String for now.
     'StorageType': 'DartUtilities::dartToString(args, {index}, exception, {auto_scope})',
 }
 
 
-def dart_value_to_cpp_value(idl_type, extended_attributes, variable_name,
+def dart_value_to_cpp_value(idl_type, interface_extended_attributes, extended_attributes, variable_name,
                             null_check, index, auto_scope=True):
     # Composite types
     array_or_sequence_type = idl_type.array_or_sequence_type
     if array_or_sequence_type:
         return dart_value_to_cpp_value_array_or_sequence(array_or_sequence_type, variable_name, index)
 
     # Simple types
     idl_type = idl_type.preprocessed_type
     add_includes_for_type(idl_type)
     base_idl_type = idl_type.base_type
 
     if 'EnforceRange' in extended_attributes:
         arguments = ', '.join([variable_name, 'EnforceRange', 'exceptionState'])
     elif idl_type.is_integer_type:  # NormalConversion
         arguments = ', '.join([variable_name, 'es'])
     else:
         arguments = variable_name
 
     if base_idl_type in DART_TO_CPP_VALUE:
         cpp_expression_format = DART_TO_CPP_VALUE[base_idl_type]
     elif idl_type.is_typed_array_type:
         # FIXME(vsm): V8 generates a type check here as well. Do we need one?
         # FIXME(vsm): When do we call the externalized version? E.g., see
         # bindings/dart/custom/DartWaveShaperNodeCustom.cpp - it calls
         # DartUtilities::dartToExternalizedArrayBufferView instead.
-        cpp_expression_format = ('DartUtilities::dartTo{idl_type}{null_check}(args, {index}, exception)')
+        # V8 always converts null here
+        cpp_expression_format = ('DartUtilities::dartTo{idl_type}WithNullCheck(args, {index}, exception)')
     elif idl_type.is_callback_interface:
         cpp_expression_format = ('Dart{idl_type}::create{null_check}(args, {index}, exception)')
     else:
         cpp_expression_format = ('Dart{idl_type}::toNative{null_check}(args, {index}, exception)')
 
     # We allow the calling context to force a null check to handle
     # some cases that require calling context info.  V8 handles all
     # of this differently, and we may wish to reconsider this approach
     null_check = 'WithNullCheck' \
-        if null_check or allow_null(idl_type, extended_attributes) else ''
-
+        if null_check or allow_null(idl_type, interface_extended_attributes, extended_attributes) else ''
     return cpp_expression_format.format(null_check=null_check,
                                         arguments=arguments,
                                         index=index,
                                         idl_type=base_idl_type,
                                         auto_scope=DartUtilities.bool_to_cpp(auto_scope))
 
 
 def dart_value_to_cpp_value_array_or_sequence(array_or_sequence_type, variable_name, index):
     # Index is None for setters, index (starting at 0) for method arguments,
     # and is used to provide a human-readable exception message
@@ skipping 12 matching lines @@
     else:
         ref_ptr_type = None
         this_cpp_type = array_or_sequence_type.cpp_type
         expression_format = 'DartUtilities::toNativeVector<{cpp_type}>(args, {index}, {variable_name}, exception)'
     expression = expression_format.format(array_or_sequence_type=array_or_sequence_type.name,
                                           cpp_type=this_cpp_type, index=index, ref_ptr_type=ref_ptr_type,
                                           variable_name=variable_name)
     return expression
 
 
-def dart_value_to_local_cpp_value(idl_type, extended_attributes, variable_name,
-                                  null_check, index=None, auto_scope=True):
+def dart_value_to_local_cpp_value(idl_type, interface_extended_attributes, extended_attributes,
+                                  variable_name, null_check, index=None, auto_scope=True):
     """Returns an expression that converts a Dart value to a C++ value as a local value."""
     idl_type = idl_type.preprocessed_type
 
     cpp_value = dart_value_to_cpp_value(
-        idl_type, extended_attributes, variable_name, null_check, index,
-        auto_scope)
+        idl_type, interface_extended_attributes, extended_attributes,
+        variable_name, null_check, index, auto_scope)
 
     return cpp_value
 
 IdlType.dart_value_to_local_cpp_value = dart_value_to_local_cpp_value
 IdlUnionType.dart_value_to_local_cpp_value = dart_value_to_local_cpp_value
 
 
 # Insure that we don't use C++ reserved names.  Today on default is a problem.
 def check_reserved_name(name):
     return 'default_value' if (name == 'default') else name
@@ skipping 256 matching lines @@
     if idl_type.is_array:
         return base_type_name + 'Array'
     if idl_type.is_sequence:
         return base_type_name + 'Sequence'
     return base_type_name
 
 IdlType.name = property(dart_name)
 IdlUnionType.name = property(dart_name)
 
 
+def typechecked_interface(extended_attributes):
+    return ('TypeChecking' in extended_attributes and\
+            DartUtilities.extended_attribute_value_contains(extended_attributes['TypeChecking'], 'Interface'))
+
+
+def typechecked_argument(idl_type, interface_extended_attributes, extended_attributes):
+    return (idl_type.is_wrapper_type and
+            (typechecked_interface(interface_extended_attributes) or
+            (typechecked_interface(extended_attributes))))
+
+
 # If True use the WithNullCheck version when converting.
-def allow_null(idl_type, extended_attributes):
+def allow_null(idl_type, interface_extended_attributes, extended_attributes):
+    if idl_type.base_type in ('DOMString', 'ByteString', 'ScalarValueString'):
+        # This logic is in cpp_types in v8_types.py, since they handle
+        # this using the V8StringResource type.  We handle it here
+        if (extended_attributes.get('TreatNullAs') == 'NullString' or
+            extended_attributes.get('TreatUndefinedAs') == 'NullString'):
+            return True
 
-    # This logic is implemented in the methods.cpp template in V8
-    if idl_type.is_nullable:
-        return True
+        if extended_attributes.get('Default') == 'NullString':
+            return True
 
-    if extended_attributes.get('Default') == 'NullString':
-        return True
+        if extended_attributes.get('Default') == 'Undefined':
+            return True
 
-    if extended_attributes.get('Default') == 'Undefined':
-        return True
+        if idl_type.is_nullable:
+            return True
 
-    # This logic is in cpp_types in v8_types.py, since they handle
-    # this using the V8StringResource type.  We handle it here
-    if (extended_attributes.get('TreatNullAs') == 'NullString' or
-        extended_attributes.get('TreatUndefinedAs') == 'NullString'):
-        return True
-    return False
+        return False
+    else:
+        # This logic is implemented in the methods.cpp template in V8
+        if (idl_type.is_nullable or
+           (not typechecked_argument(idl_type, interface_extended_attributes, extended_attributes))):
+            return True
+
+        if extended_attributes.get('Default') == 'Undefined':
+            return True
+
+        return False