IDL: Drop value conversion (V8 -> C++) macros from generated code

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 157 matching lines @@
         'number_of_arguments': len(arguments),
         'number_of_required_arguments': len([
             argument for argument in arguments
             if not (argument.is_optional or argument.is_variadic)]),
         'number_of_required_or_variadic_arguments': len([
             argument for argument in arguments
             if not argument.is_optional]),
         'only_exposed_to_private_script': is_only_exposed_to_private_script,
         'per_context_enabled_function': v8_utilities.per_context_enabled_function_name(method),  # [PerContextEnabled]
         'private_script_v8_value_to_local_cpp_value': idl_type.v8_value_to_local_cpp_value(
-            extended_attributes, 'v8Value', 'cppValue', isolate='scriptState->isolate()', used_in_private_script=True),
+            extended_attributes, 'v8Value', 'cppValue', isolate='scriptState->isolate()', bailout_return_value='false'),
         'property_attributes': property_attributes(interface, method),
+        'returns_promise': method.returns_promise,
         'runtime_enabled_function': v8_utilities.runtime_enabled_function_name(method),  # [RuntimeEnabled]
         'should_be_exposed_to_script': not (is_implemented_in_private_script and is_only_exposed_to_private_script),
         'signature': 'v8::Local<v8::Signature>()' if is_static or 'DoNotCheckSignature' in extended_attributes else 'defaultSignature',
         'use_output_parameter_for_result': idl_type.use_output_parameter_for_result,
         'use_local_result': use_local_result(method),
         'v8_set_return_value': v8_set_return_value(interface.name, method, this_cpp_value),
         'v8_set_return_value_for_main_world': v8_set_return_value(interface.name, method, this_cpp_value, for_main_world=True),
         'visible': is_visible,
         'world_suffixes': ['', 'ForMainWorld'] if 'PerWorldBindings' in extended_attributes else [''],  # [PerWorldBindings],
     }
@@ skipping 45 matching lines @@
         'is_variadic': argument.is_variadic,
         'is_variadic_wrapper_type': is_variadic_wrapper_type,
         'is_wrapper_type': idl_type.is_wrapper_type,
         'name': argument.name,
         'private_script_cpp_value_to_v8_value': idl_type.cpp_value_to_v8_value(
             argument.name, isolate='scriptState->isolate()',
             creation_context='scriptState->context()->Global()'),
         'use_permissive_dictionary_conversion': 'PermissiveDictionaryConversion' in extended_attributes,
         'v8_set_return_value': v8_set_return_value(interface.name, method, this_cpp_value),
         'v8_set_return_value_for_main_world': v8_set_return_value(interface.name, method, this_cpp_value, for_main_world=True),
-        'v8_value_to_local_cpp_value': v8_value_to_local_cpp_value(argument, index, return_promise=method.returns_promise, restricted_float=restricted_float),
+        'v8_value_to_local_cpp_value': v8_value_to_local_cpp_value(method, argument, index, restricted_float=restricted_float),
         'vector_type': v8_types.cpp_ptr_type('Vector', 'HeapVector', idl_type.gc_type),
     }
 
 
 def argument_declarations_for_private_script(interface, method):
     argument_declarations = ['LocalFrame* frame']
     argument_declarations.append('%s* holderImpl' % interface.name)
     argument_declarations.extend(['%s %s' % (argument.idl_type.cpp_type_args(
         used_as_rvalue_type=True), argument.name) for argument in method.arguments])
     if method.idl_type.name != 'void':
@@ skipping 84 matching lines @@
             # result is of type Nullable<T>
             cpp_value = 'result.get()'
         else:
             cpp_value = 'result'
         release = idl_type.release
 
     script_wrappable = 'impl' if inherits_interface(interface_name, 'Node') else ''
     return idl_type.v8_set_return_value(cpp_value, extended_attributes, script_wrappable=script_wrappable, release=release, for_main_world=for_main_world)
 
 
-def v8_value_to_local_cpp_variadic_value(argument, index, return_promise):
+def v8_value_to_local_cpp_variadic_value(method, argument, index, return_promise):
     assert argument.is_variadic
     idl_type = argument.idl_type
+    this_cpp_type = idl_type.cpp_type
 
-    suffix = ''
+    if method.returns_promise:
+        check_expression = 'exceptionState.hadException()'
+    else:
+        check_expression = 'exceptionState.throwIfNeeded()'

[haraken, 2015/02/24 15:59:38]

I'm a bit confused about when throwIfNeeded() should be used.

- throwIfNeeded() is used sometimes as check_expression and sometimes as
throw_expression. Why?

- In most value conversions, throw_expression shouldn't be needed because we
don't want to call throwIfNeeded(). When do we need throw_expression?

[Jens Widell, 2015/02/24 16:15:58]

I use throwIfNeeded() as throw_expression when check_expression is some other
expression that works the same way, IOW returns a true value if an exception was
thrown.

That's only the case for union and dictionary types, and that's only possible
because I also changed their toImpl() to return such a truth value. That change
is not really required; we could call those toImpl() functions in a void
context, and then use throwIfNeeded() as check_expression in that case too.

But calling toImpl() in a void context requires the set_expression that I had
for a while and then removed, so we'd exchange throw_expression for
set_expression. That exchange would actually make things a bit simpler, I think,
so...

Now that you brought it up, I'm inclined to change my mind and do it that way
instead. IOW, revert the return-value-from-toImpl() change, and have
set_expression (used in a single case) instead of throw_expression (currently
used in that same single case).

 
-    macro = 'TONATIVE_VOID_EXCEPTIONSTATE'
-    macro_args = [
-        argument.name,
-        'toImplArguments<%s>(info, %s, exceptionState)' % (idl_type.cpp_type, index),
-        'exceptionState',
-    ]
-
-    if return_promise:
-        suffix += '_PROMISE'
-        macro_args.extend(['info', 'ScriptState::current(info.GetIsolate())'])
-
-    suffix += '_INTERNAL'
-
-    return '%s%s(%s)' % (macro, suffix, ', '.join(macro_args))
+    return {
+        'assign_expression': 'toImplArguments<%s>(info, %s, exceptionState)' % (this_cpp_type, index),
+        'check_expression': check_expression,
+        'cpp_type': this_cpp_type,
+        'cpp_name': argument.name,
+        'declare_variable': False,
+    }
 
 
-def v8_value_to_local_cpp_value(argument, index, return_promise=False, restricted_float=False):
+def v8_value_to_local_cpp_value(method, argument, index, return_promise=False, restricted_float=False):
     extended_attributes = argument.extended_attributes
     idl_type = argument.idl_type
     name = argument.name
     if argument.is_variadic:
-        return v8_value_to_local_cpp_variadic_value(argument, index, return_promise)
+        return v8_value_to_local_cpp_variadic_value(method, argument, index, return_promise)
     return idl_type.v8_value_to_local_cpp_value(extended_attributes, 'info[%s]' % index,
                                                 name, index=index, declare_variable=False,
-                                                return_promise=return_promise,
+                                                use_exception_state=method.returns_promise,
                                                 restricted_float=restricted_float)
 
 
 ################################################################################
 # Auxiliary functions
 ################################################################################
 
 # [NotEnumerable]
 def property_attributes(interface, method):
     extended_attributes = method.extended_attributes
@@ skipping 57 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)))