API functions returning Promises should not throw exceptions.

Source/bindings/scripts/v8_methods.py

Index: Source/bindings/scripts/v8_methods.py
diff --git a/Source/bindings/scripts/v8_methods.py b/Source/bindings/scripts/v8_methods.py
index 94f22f33814e7d2d9871f4d72c35767929293390..880cb2ab323e3889ee688f8ac5e3d7cf18d58db9 100644
--- a/Source/bindings/scripts/v8_methods.py
+++ b/Source/bindings/scripts/v8_methods.py
@@ -172,7 +172,8 @@ def generate_argument(interface, method, argument, index):
         'name': argument.name,
         'v8_set_return_value_for_main_world': v8_set_return_value(interface.name, method, this_cpp_value, for_main_world=True),
         'v8_set_return_value': v8_set_return_value(interface.name, method, this_cpp_value),
-        'v8_value_to_local_cpp_value': v8_value_to_local_cpp_value(argument, index),
+        'v8_value_to_local_cpp_value': v8_value_to_local_cpp_value(argument, index, async=False),
+        'v8_value_to_local_cpp_value_async': v8_value_to_local_cpp_value(argument, index, async=True),
     }
 
 
@@ -243,15 +244,28 @@ def v8_set_return_value(interface_name, method, cpp_value, for_main_world=False)
     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_value(argument, index):
+def v8_value_to_local_cpp_variadic_value(argument, index, async):
+    assert argument.is_variadic
+    idl_type = argument.idl_type
+    vector_type = v8_types.cpp_ptr_type('Vector', 'HeapVector', idl_type.gc_type)
+
+    macro = 'TONATIVE_VOID' + ('_ASYNC' if async else '')
+    macro_args_format = '{vector_type}<{cpp_type}>, {name}, toNativeArguments<{cpp_type}>(info, {index})' + (', info' if async else '')

[Nils Barth (inactive), 2014/04/11 11:08:40]

I think this would be clearer as a list, followed by ', '.join, i.e.,

cpp_type = idl_type.cpp_type
macro_ars = ['%s<%s>' % (vector_type, cpp_type),
             name,
             'toNativeArguments<%s>(info, %s)' % (cpp_type, index)]
if async:
    macro_args.append('info')

[yhirano, 2014/04/14 01:03:37]

Done.

+    macro_args = {
+        'vector_type': vector_type,
+        'cpp_type': idl_type.cpp_type,
+        'name': argument.name,
+        'index': index,
+    }
+    return '{0}({1})'.format(macro, macro_args_format.format(**macro_args))

[Nils Barth (inactive), 2014/04/11 11:08:40]

For simple positional format we prefer %, so this becomes:
return '%s(%s)' % (macro, ', '.join(macro_args))

[yhirano, 2014/04/14 01:03:37]

Done.

+
+
+def v8_value_to_local_cpp_value(argument, index, async=False):
     extended_attributes = argument.extended_attributes
     idl_type = argument.idl_type
     name = argument.name
     if argument.is_variadic:
-        vector_type = v8_types.cpp_ptr_type('Vector', 'HeapVector', idl_type.gc_type)
-        return 'TONATIVE_VOID({vector_type}<{cpp_type}>, {name}, toNativeArguments<{cpp_type}>(info, {index}))'.format(
-            vector_type=vector_type, cpp_type=idl_type.cpp_type, name=name,
-            index=index)
+        return v8_value_to_local_cpp_variadic_value(argument, index, async)
     # [Default=NullString]
     if (argument.is_optional and idl_type.name == 'String' and
         extended_attributes.get('Default') == 'NullString'):
@@ -259,7 +273,7 @@ def v8_value_to_local_cpp_value(argument, index):
     else:
         v8_value = 'info[%s]' % index
     return idl_type.v8_value_to_local_cpp_value(extended_attributes, v8_value,
-                                                name, index=index)
+                                                name, index=index, async=async)
 
 
 ################################################################################