Create fewer local v8::TryCatch objects in generated bindings code

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 dd32e7c7251a2e34b83f721c7d8fec6947755aa8..ee10a9a718726a888d84ee96cd8ae397cb7f8dd8 100644
--- a/Source/bindings/scripts/v8_methods.py
+++ b/Source/bindings/scripts/v8_methods.py
@@ -40,6 +40,12 @@ import v8_utilities
 from v8_utilities import has_extended_attribute_value
 
 
+def argument_needs_try_catch(argument):
+    return not (argument.get("is_callback_interface") or

[Nils Barth (inactive), 2014/05/07 03:02:19]

Single quotes.
Also, can't these just be usual key access?
(No need for dict.get() that I can see; if there is, it's preferred to make sure
these keys are always created, to simplify these functions.)

[Jens Widell, 2014/05/07 10:34:46]

Neither 'is_callback_interface' nor 'is_variadic_wrapper_type' was set by
constructor_argument(), and I used dict.get() for 'idl_type' too for
consistency, I guess.  But since you removed constructor_argument(), there's no
longer any need for dict.get().

[Nils Barth (inactive), 2014/05/08 00:55:13]

Got it -- I thought it might be something like that;
glad it's slicker now!

+                argument.get("idl_type") == "SerializedScriptValue" or
+                argument.get("is_variadic_wrapper_type"))
+
+
 def generate_method(interface, method):
     arguments = method.arguments
     extended_attributes = method.extended_attributes
@@ -79,10 +85,14 @@ def generate_method(interface, method):
         'DoNotCheckSecurity' not in extended_attributes)
     is_raises_exception = 'RaisesException' in extended_attributes
 
+    generated_arguments = [generate_argument(interface, method, argument, index)
+                           for index, argument in enumerate(arguments)]
+
     return {
         'activity_logging_world_list': v8_utilities.activity_logging_world_list(method),  # [ActivityLogging]
-        'arguments': [generate_argument(interface, method, argument, index)
-                      for index, argument in enumerate(arguments)],
+        'arguments': generated_arguments,
+        'arguments_need_try_catch': any(

[Nils Barth (inactive), 2014/05/07 03:02:19]

Fix linebreaks, wrapping as follows:
        'arguments_need_try_catch': any(argument_needs_try_catch(argument)
                                        for argument in generated_arguments),

+            argument_needs_try_catch(argument) for argument in generated_arguments),
         'conditional_string': v8_utilities.conditional_string(method),
         'cpp_type': idl_type.cpp_type,
         'cpp_value': this_cpp_value,
@@ -143,8 +153,18 @@ def generate_argument(interface, method, argument, index):
     this_cpp_value = cpp_value(interface, method, index)
     is_variadic_wrapper_type = argument.is_variadic and idl_type.is_wrapper_type
 
+    if argument.is_variadic and not is_variadic_wrapper_type:

[Nils Barth (inactive), 2014/05/07 03:02:19]

Slightly more direct:
if argument.is_variadic and not idl_typ.is_wrapper_type:

+        cpp_type = idl_type.cpp_type_args(extended_attributes=extended_attributes,

[Nils Barth (inactive), 2014/05/07 03:02:19]

Prefer single assignment:
element_cpp_type = ...

cpp_type = v8_types.cpp_template_type(vector_type, element_cpp_type)

+                                          used_in_cpp_sequence=is_variadic_wrapper_type)

[Nils Barth (inactive), 2014/05/07 03:02:19]

You can drop used_in_cpp_sequence, as it's always False, which is default.

+        vector_type = v8_types.cpp_ptr_type('Vector', 'HeapVector', idl_type.gc_type)
+        cpp_type = v8_types.cpp_template_type(vector_type, cpp_type)
+    else:
+        cpp_type = idl_type.cpp_type_args(extended_attributes=extended_attributes,

[Nils Barth (inactive), 2014/05/07 03:02:19]

Do we need to pass extended_attributes here?

(It's only needed in rare cases generally, so we've been omitting it for
simplicity and to assert that this *isn't* happening here.)

[Jens Widell, 2014/05/07 10:34:46]

Not passing it makes run-bindings-test fail with this error:
http://pastebin.com/MtuKxRL4

[Nils Barth (inactive), 2014/05/08 00:55:13]

Got it, looks like there is a use in constructors;
thanks for checking!

+                                          used_as_argument=not is_variadic_wrapper_type,
+                                          used_in_cpp_sequence=is_variadic_wrapper_type)
+
     return {
-        'cpp_type': idl_type.cpp_type_args(used_in_cpp_sequence=is_variadic_wrapper_type),
+        'cpp_type': cpp_type,
         'cpp_value': this_cpp_value,
         'enum_validation_expression': idl_type.enum_validation_expression,
         'has_default': 'Default' in extended_attributes,
@@ -250,9 +270,8 @@ def v8_value_to_local_cpp_value(argument, index):
     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,
+        return 'TONATIVE_VOID_NO_DECL({name}, toNativeArguments<{cpp_type}>(info, {index}))'.format(
+            cpp_type=idl_type.cpp_type, name=name,
             index=index)
     # [Default=NullString]
     if (argument.is_optional and idl_type.name == 'String' and
@@ -261,7 +280,7 @@ 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, declare_variable=False)
 
 
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