Generate binding code for VoidCallback.idl with code generator in python

Source/bindings/scripts/code_generator_v8.py

Index: Source/bindings/scripts/code_generator_v8.py
diff --git a/Source/bindings/scripts/code_generator_v8.py b/Source/bindings/scripts/code_generator_v8.py
index d2f933044a5a171b5f1109ef2dc94fa95f660842..9af909040b2c1935f4c4a0625a09cc42f64713e2 100644
--- a/Source/bindings/scripts/code_generator_v8.py
+++ b/Source/bindings/scripts/code_generator_v8.py
@@ -26,16 +26,313 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-"""Generate Blink V8 bindings (.h and .cpp files).
+"""
+Generate Blink V8 bindings (.h and .cpp files).
 
 Input: An object of class IdlDefinitions, containing an IDL interface X
 Output: V8X.h and V8X.cpp
-
-FIXME: Currently a stub, as part of landing the parser and code generator
-incrementally. Only implements generation of dummy .cpp and .h files.
 """
 
-import os.path
+import os
+import posixpath
+import sys
+import re

[haraken, 2013/07/26 02:03:30]

Nit: Alphabetical order please.

+
+import idl_definitions
+
+# jinja2 is in chromium's third_party directory
+module_path, module_name = os.path.split(__file__)
+third_party = os.path.join(module_path, os.pardir, os.pardir, os.pardir, os.pardir)
+sys.path.append(third_party)
+import jinja2
+
+
+def apply_template(path_to_template, params):

[haraken, 2013/07/26 02:03:30]

params => parameters

Probably 'contents' might be better.

+    dirname, basename = os.path.split(path_to_template)
+    jinja_env = jinja2.Environment(trim_blocks=True, loader=jinja2.FileSystemLoader([dirname]))
+    template = jinja_env.get_template(basename)
+    return template.render(params)
+
+
+def get_v8_class_name(interface):

[haraken, 2013/07/26 02:03:30]

get_v8_class_name => v8_class_name

Omitting "get" is a Blink convention. It's not good that the Perl code generator
is using GetV8ClassName().

+    return 'V8' + interface.name
+
+
+def get_impl_name(interface_or_function):

[Nils Barth (inactive), 2013/07/25 11:58:20]

This could just be:
return interface_or_function.extended_attributes.get('ImplementedAs',
interface_or_function.name)

In other contexts, the last 3 lines could just be:
return implementedAs or interface_or_function.name

[haraken, 2013/07/26 02:03:30]

Good point! You're a Python expert :)

Other comments:

get_impl_name => cpp_class_name

In the new code generator, I suggest using "cpp" instead of "implementation" or
"impl" or "native". Having v8_class_name and cpp_class_name would be clearer
than having v8_class_name and impl_name.

Would you do the "implementation/impl/native" => "cpp" renaming in other places
as well?

[kojih, 2013/07/26 07:18:38]

I agree. done.

+    implementedAs = interface_or_function.extended_attributes.get('ImplementedAs')
+    if implementedAs is not None:
+        return implementedAs
+    return interface_or_function.name
+
+
+def get_conditional_string(interface_or_attribute_or_operation):

[haraken, 2013/07/26 02:03:30]

get_conditional_string => conditional_string

+    conditional = interface_or_attribute_or_operation.extended_attributes.get('Conditional')
+    if conditional is None:

[Nils Barth (inactive), 2013/07/25 11:58:20]

if not conditional:
    return ''
...and don't need the else afterwards, as you've returned.

Alternative coding is explicitly checking the key, rather than for the default
value:
if 'Conditional' not in interface_or_attribute_or_operation.extended_attributes:
    return ''
conditional =
interface_or_attribute_or_operation.extended_attributes['Conditional']

+        return ''
+    else:

[Nils Barth (inactive), 2013/07/25 11:58:20]

No need for an else, since you've just returned.

+        operator = ''
+        if '&' in conditional:

[Nils Barth (inactive), 2013/07/25 11:58:20]

This seems clearer with a for loop
(anyway, no need for the last else):
for operator in ['&', '|']:
    if operator in conditional:
        # Avoid duplicated conditions.
        conditions = set(conditional.split(operator))
        return (' %s%s ' % (operator, operator)).join(['ENABLE(%s)' % expression
for expression in sorted(conditions)])
return 'ENABLE(%s)' % conditional

[haraken, 2013/07/26 02:03:30]

Looks better!

[kojih, 2013/07/26 07:18:38]

Thanks, done.

+            operator = '&'
+        if '|' in conditional:
+            operator = '|'
+        if operator == '':
+            return 'ENABLE(%s)' % conditional
+        else:
+            # Avoid duplicated conditions.
+            conditions = set(conditional.split(operator))
+            return (' %s%s ' % (operator, operator)).join(['ENABLE(%s)' % expression for expression in sorted(conditions)])
+
+
+def sort_and_remove_duplicate(includes):
+    return sorted(list(set(includes)))

[haraken, 2013/07/26 02:03:30]

How about assuming that includes is a set? There would be no reason we want to
manage includes in a list. Then you can remove this helper method, since you can
just sort includes in the caller sites.

[kojih, 2013/07/26 07:18:38]

Good idea! done.

+
+
+class NativeTypeAndJSType:

[haraken, 2013/07/26 02:03:30]

CPPTypeAndV8Type

Actually I don't think this class is needed. As far as I see the Perl code
generator, the cpp type is not used. We will need only V8 type.

+    def __init__(self, native_type=None, js_type=None):
+        self.native_type = native_type
+        self.js_type = js_type
+
+# IDL data_type: [element's C++ data_type, V8 data_type]

[haraken, 2013/07/26 02:03:30]

I'd remove this comment.

+typed_arrays = {
+    'ArrayBuffer': NativeTypeAndJSType(),
+    'ArrayBufferView': NativeTypeAndJSType(),

[haraken, 2013/07/26 02:03:30]

As far as I see the Perl code generator, these two items are not used. We don't
want to migrate unnecessary code to the new Python flow. (This is the great
benefit of the rewrite!)

This is the reason why I want to land things incrementally. Let's migrate things
to the new Python flow incrementally when we find they're really necessary. In
that sense, you might want to drop all unused code from this CL. For example,
typed_arrays wouldn't be needed in this CL.

[kojih, 2013/07/26 07:18:38]

ok.

+    'Uint8Array': NativeTypeAndJSType('unsigned char', 'v8::kExternalUnsignedByteArray'),
+    'Uint8ClampedArray': NativeTypeAndJSType('unsigned char', 'v8::kExternalPixelArray'),
+    'Uint16Array': NativeTypeAndJSType('unsigned short', 'v8::kExternalUnsignedShortArray'),
+    'Uint32Array': NativeTypeAndJSType('unsigned int', 'v8::kExternalUnsignedIntArray'),
+    'Int8Array': NativeTypeAndJSType('signed char', 'v8::kExternalByteArray'),
+    'Int16Array': NativeTypeAndJSType('short', 'v8::kExternalShortArray'),
+    'Int32Array': NativeTypeAndJSType('int', 'v8::kExternalIntArray'),
+    'Float32Array': NativeTypeAndJSType('float', 'v8::kExternalFloatArray'),
+    'Float64Array': NativeTypeAndJSType('double', 'v8::kExternalDoubleArray'),
+}
+
+primitive_types = set([

[haraken, 2013/07/26 02:03:30]

It looks like that methods and global variables are placed randomly in the code
generator. (This is an existing problem in the Perl code generator.) Please
consider organizing the order of all methods and global variables for better
readability. For example, you can put global variables at the beginning of the
file and gather helper methods at the end of the file.

[kojih, 2013/07/26 07:18:38]

ok, done.

+    'boolean',
+    'void',
+    'Date',
+    'byte',
+    'octet',
+    'short',
+    'long',
+    'long long',
+    'unsigned short',
+    'unsigned long',
+    'unsigned long long',
+    'float',
+    'double',
+])
+
+
+def get_sequence_type(data_type):

[haraken, 2013/07/26 02:03:30]

Drop this method in this CL.

+    matched = re.match(r'^sequence<([\w\s]+)>.*', data_type)
+    if matched:
+        return matched.group(1)
+    return None
+
+
+def get_array_type(data_type):

[haraken, 2013/07/26 02:03:30]

Ditto.

+    matched = re.match(r'^([\w\s]+)\[\]', data_type)
+    if matched:
+        return matched.group(1)
+    return None
+
+
+def is_typed_array_type(data_type):

[haraken, 2013/07/26 02:03:30]

Ditto.

+    return data_type in typed_arrays
+
+
+def is_primitive_type(data_type):
+    return data_type in primitive_types
+
+
+def is_union_type(data_type):

[haraken, 2013/07/26 02:03:30]

Ditto.

+    return isinstance(data_type, idl_definitions.IdlUnionType)
+
+
+def get_native_type(data_type):

[haraken, 2013/07/26 02:03:30]

get_native_type => native_type

+    """
+    Return native data_type corresponds to IDL data_type.

[Nils Barth (inactive), 2013/07/25 11:58:20]

Syntax: no initial linebreak, but linebreak after first line.
Style: 'Return*s*', etc.
Also some wording changes:
"""Returns native data_type corresponding to IDL data_type.

@param[in] data_type ... IDL data_type
@param[in] called_by_webcore
@param[in] used_as_parameter
"""

Also, I don't understand the comment; could you elaborate?

[haraken, 2013/07/26 02:03:30]

native => cpp
I'd remove this part.

+    @param[in] data_type ... IDL data_type
+    @param[in] called_by_webcore
+    @param[in] used_as_parameter
+    """
+    if data_type == 'boolean':
+        return 'bool'
+    raise Exception('Not supported')
+
+
+def get_callback_parameter_declaration(operation):

[haraken, 2013/07/26 02:03:30]

get_callback_parameter_declaration => callback_argument_declaration

We might want to rename "parameter" to "argument" for consistency.

[kojih, 2013/07/26 07:18:38]

done.

+    parameters = ['%s %s' % (get_native_type(parameter.data_type), parameter.name) for parameter in operation.arguments]
+    return ', '.join(parameters)
+
+
+class CodeGeneratorV8:
+    def __init__(self, definitions, interface_name, output_directory, idl_directories, verbose=False, generate_h=True, generate_cpp=True):

[haraken, 2013/07/26 02:03:30]

Do we need generate_h and generate_cpp ?

In case where we don't need h and cpp, we can just directly call
generate_dummy_header_and_cpp from idl_compiler.py.

[Nils Barth (inactive), 2013/07/26 03:02:40]

I was wondering the same thing.
If we really want to separate these, we should just have
generate_h and generate_cpp *methods*:
there's no need for these to be parameters.

[kojih, 2013/07/26 07:18:38]

oh this was for rewriting work. (for example, generate only h and do diff)
removed.

+        self.idl_definitions = definitions
+        self.interface_name = interface_name
+        self.idl_directories = idl_directories
+        self.output_directory = output_directory
+        self.generate_h = generate_h
+        self.generate_cpp = generate_cpp
+        self.verbose = verbose
+        self.header = ''
+        self.implementation = ''

[haraken, 2013/07/26 02:03:30]

implementation => cpp

+        self.cached_interfaces = {}

[haraken, 2013/07/26 02:03:30]

Drop this in this CL.

+        self.common_template_parameters = {}
+        self.interface = None
+        self.enum_types = dict([[enum.name, enum.values] for enum in self.idl_definitions.enumerations.values()])

[Nils Barth (inactive), 2013/07/25 11:58:20]

This would probably be easier at the parser side.
May be hard with Perl around, but I can do this in future.
Could you put a FIXME here?

[haraken, 2013/07/26 02:03:30]

I'd drop this in this CL.

[Nils Barth (inactive), 2013/07/26 03:02:40]

Good point.
Koji, no enums in these IDLs, right?

[kojih, 2013/07/26 07:18:38]

exactly. removed.

+        self.callback_function_types = self.idl_definitions.callback_functions

[haraken, 2013/07/26 02:03:30]

Shall we rename "function" to "method"? I think we're using "method" in
generated code.

By the way, why do you call this not self.callback_functions but
self.callback_function_types?

[Nils Barth (inactive), 2013/07/26 03:02:40]

This is an important general point:
the parser strictly follows the Web IDL naming, but in the C++ code
we use standard C++ names (e.g., "method" rather than "operator",
"parameters" rather than "arguments").
Renaming when you read from the parsed data is probably the clearest way to
handle this.
I think this is (primarily?) used just to check types
(so it could be a set),
but you're right, it's actually a full dict.
Koji?

[kojih, 2013/07/26 07:18:38]

Yeah now this is unnecessary.
This was primarily straight-forward translation of the perl code:
    %callbackFunctionTypeHash = map { $_->name => $_ }
@{$idlDocument->callbackFunctions};

+
+    def is_enum_type(self, data_type):

[haraken, 2013/07/26 02:03:30]

Drop this in this CL.

+        return data_type in self.enum_types
+
+    def is_callback_function_type(self, data_type):
+        return data_type in self.callback_function_types
+
+    def get_includes_for_type(self, data_type):
+        if self.skip_include_header(data_type):
+            return []
+        includes = []

[haraken, 2013/07/26 02:03:30]

Don't you want to use a set for includes?

+        if data_type == 'EventListener':
+            includes.append('core/dom/EventListener.h')
+        elif data_type == 'SerializedScriptValue':
+            includes.append('bindings/v8/SerializedScriptValue.h')
+        elif data_type == 'any' or self.is_callback_function_type(data_type):
+            includes.append('bindings/v8/ScriptValue.h')

[haraken, 2013/07/26 02:03:30]

Are these needed in this CL? Header includes in the Perl code generator are much
messier than is necessary. We're including a bunch of unnecessary files and want
to clean them up in the rewrite. So let's add #include when it becomes really
necessary in your CL.

+        else:
+            includes.append('V8%s.h' % data_type)
+        return includes
+
+    def get_includes_for_parameter(self, parameter):

[haraken, 2013/07/26 02:03:30]

parameter => argument

The same comment to other places.

+        includes = []

[haraken, 2013/07/26 02:03:30]

Ditto. Can you use a set?

+        array_or_sequence_type = get_array_type(parameter.data_type) or get_sequence_type(parameter.data_type)
+        if array_or_sequence_type:
+            if self.is_ref_ptr_type(array_or_sequence_type):

[haraken, 2013/07/26 02:03:30]

I don't understand what this branch is for. Maybe it's needed but maybe it's not
needed.

There are a lot of branches in the Perl code generation that are never taken. So
let's clean them up by migrating really-necessary branches. So you might want to
drop this branch if it's not needed in this CL.

+                includes += self.get_includes_for_type(array_or_sequence_type)
+        else:
+            includes += self.get_includes_for_type(parameter.data_type)
+        return includes
+
+    def is_ref_ptr_type(self, data_type):
+        return not(is_union_type(data_type) or
+                   data_type == 'any' or data_type == 'DOMString' or

[Nils Barth (inactive), 2013/07/25 11:58:20]

A bit clearer to consistently have each on the same line.
...and probably better to have the literal checks first,
then the function ones.

[kojih, 2013/07/26 07:18:38]

I'll do that in the following patches. (this part is dropped in this CL)

+                   is_primitive_type(data_type) or
+                   get_array_type(data_type) or
+                   get_sequence_type(data_type) or
+                   self.is_callback_function_type(data_type) or
+                   self.is_enum_type(data_type))
+
+    def skip_include_header(self, data_type):

[haraken, 2013/07/26 02:03:30]

skip_include_header => is_skip_include

+        return is_primitive_type(data_type) or \
+               self.is_enum_type(data_type) or \

[Nils Barth (inactive), 2013/07/25 11:58:20]

Style: use parentheses for implicit line continuation instead
of explicit line continuation with backslashes.

http://google-styleguide.googlecode.com/svn/trunk/pyguide.html#Line_length

[kojih, 2013/07/26 07:18:38]

I'll do that in the following patches. (this part is dropped in this CL)

+               self.is_callback_function_type(data_type) or \
+               data_type == 'DOMString'
+
+    def header_files_for_interface(self, interface_name, impl_class_name):

[haraken, 2013/07/26 02:03:30]

get_includes_for_interface (for naming consistency with other methods)

Actually I don't fully understand why we need all of
get_includes_for_{type,parameter,interface}. We might clean them up when
migrating to the new Python flow.

[kojih, 2013/07/26 07:18:38]

Good point.........

HeaderFilesForInterface actually returns webcore header of the specified
type(interface name).
On the other hand AddIncludesForType returns binding header of the specified
type.

So I rename 'header_files_for_interface' to 'cpp_class_header(data_type)' and
add 'v8_class_header(data_type)' later.

+        includes = []

[haraken, 2013/07/26 02:03:30]

Can you use a set?

[kojih, 2013/07/26 07:18:38]

done.

+        if is_typed_array_type(interface_name):
+            includes.append('wtf/%s.h' % interface_name)
+        elif not self.skip_include_header(interface_name):
+            # FIXME: parser will prepare posix form relative path from Source/bindings in IdlInterface.file_name

[haraken, 2013/07/26 02:03:30]

Yeah, we should do that.

nbarth: could you do that? :)

[Nils Barth (inactive), 2013/07/26 03:02:40]

Will do!
It's a bit tricky to do properly, since we want to export the legacy
form for JSON comparison with Perl, but I'll do it cleanly,
leaving a compatibility hack for later removal.

+            idl_filename = self.idl_definitions.file_name
+            idl_rel_path_local = os.path.relpath(idl_filename)
+            idl_rel_path_posix = idl_rel_path_local.replace(os.path.sep, posixpath.sep)
+
+            idl_dir_posix = posixpath.join('bindings', posixpath.dirname(idl_rel_path_posix))
+            includes.append(posixpath.join(idl_dir_posix, impl_class_name + '.h'))
+        return includes
+
+    def generate_interface(self, interface):
+        self.interface = interface
+        self.common_template_parameters = {

[haraken, 2013/07/26 02:03:30]

Nit: common_template_parameters => common_template_contents

parameter is a bit confusing with parameters of DOM operations.

[kojih, 2013/07/26 07:18:38]

done.

[kojih, 2013/07/26 07:18:38]

done. replaced all template_parameters with template_contents/

+            'conditional_string': get_conditional_string(self.interface),
+        }
+        if interface.is_callback:
+            template_parameters = self.common_template_parameters.copy()
+            template_parameters.update(self.generate_callback_template_parameters())
+            if self.generate_h:
+                self.header = apply_template('templates/callback.h', template_parameters)
+            if self.generate_cpp:
+                self.implementation = apply_template('templates/callback.cpp', template_parameters)
+        else:
+            if self.generate_h:
+                self.generate_header()
+            if self.generate_cpp:
+                self.generate_implementation()
+
+    def write_interface(self):
+        if self.interface_name in self.idl_definitions.interfaces:
+            interface = self.idl_definitions.interfaces[self.interface_name]
+            self.generate_interface(interface)
+            if self.generate_h:
+                header_filename = os.path.join(self.output_directory, get_v8_class_name(self.interface) + '.h')
+                with open(header_filename, 'w') as f:

[haraken, 2013/07/26 02:03:30]

Nit: f => file

[Nils Barth (inactive), 2013/07/26 03:02:40]

Even better, header_file
For clarity, I've been consistently using *_filename for the string and *_file
for the corresponding file, so you have:
with open(header_filename, 'w') as header_file:
    ...
...which is clear.

[kojih, 2013/07/26 07:18:38]

done. we can't use type, file as variable name in python :(

+                    f.write(self.header)
+            if self.generate_cpp:
+                implementation_filename = os.path.join(self.output_directory, get_v8_class_name(self.interface) + '.cpp')

[haraken, 2013/07/26 02:03:30]

implementation_filename => cpp_filename

[kojih, 2013/07/26 07:18:38]

done.

+                with open(implementation_filename, 'w') as f:

[haraken, 2013/07/26 02:03:30]

Nit: f => file

[Nils Barth (inactive), 2013/07/26 03:02:40]

=> cpp_file

+                    f.write(self.implementation)
+        else:
+            raise Exception('%s not in IDL definitions' % self.interface_name)

[haraken, 2013/07/26 02:03:30]

I'd prefer:

  if not self.interface_name in self.idl_definitions.interfaces:
    raise Exception('%s not in IDL definitions' % self.interface_name)
  ...
  ...

to avoid deep indentations.

[Nils Barth (inactive), 2013/07/26 03:02:40]

BTW:
if key not in dict:
    ...
...is a bit clearer and preferred to:

if not key in dict:
    ...
(Go syntactic sugar!)

[kojih, 2013/07/26 07:18:38]

done.

+
+    def generate_callback_template_parameters(self):

[haraken, 2013/07/26 02:03:30]

generate_callback_template_parameters => generate_callback_functions

Note: here we might want to use "function" instead of "method" because "callback
function" is a concept of the Web IDL spec.

+        impl_class_name = get_impl_name(self.interface)
+        v8_class_name = get_v8_class_name(self.interface)
+        functions = []
+        implementation_includes = [

[haraken, 2013/07/26 02:03:30]

Can you use a set for the includes?

[haraken, 2013/07/26 02:03:30]

implementation_includes => cpp_includes

+            'core/dom/ScriptExecutionContext.h',
+            'bindings/v8/V8Binding.h',
+            'bindings/v8/V8Callback.h',
+            'wtf/Assertions.h',
+        ]
+        header_includes = [

[haraken, 2013/07/26 02:03:30]

Ditto.

+            'bindings/v8/ActiveDOMCallback.h',
+            'bindings/v8/DOMWrapperWorld.h',
+            'bindings/v8/ScopedPersistent.h',
+        ]
+        header_includes += self.header_files_for_interface(self.interface.name, impl_class_name)
+        for operation in self.interface.operations:
+            custom = 'Custom' in operation.extended_attributes
+            function = {}
+            if not custom:

[haraken, 2013/07/26 02:03:30]

if not 'Custom' in operation.extended_attributes:

[Nils Barth (inactive), 2013/07/26 03:02:40]

Even better:
if 'Custom' not in operation.extended_attributes:

[kojih, 2013/07/26 07:18:38]

done.

+                implementation_includes += self.get_includes_for_type(operation.data_type)
+                for parameter in operation.arguments:
+                    implementation_includes += self.get_includes_for_parameter(parameter)
+                if operation.data_type != 'boolean':
+                    raise Exception('We don''t yet support callbacks that return non-boolean values.')

[Nils Barth (inactive), 2013/07/25 11:58:20]

BTW, it's fine to use "" for quotes if there are single quotes inside,
as it makes it clearer.

[kojih, 2013/07/26 07:18:38]

done.

+                parameters = []
+                if len(operation.arguments) > 0:

[Nils Barth (inactive), 2013/07/25 11:58:20]

No need for > 0.

[kojih, 2013/07/26 07:18:38]

done.

+                    raise Exception('Not supported')
+                function = {
+                    'return_type': get_native_type(operation.data_type),
+                    'name': operation.name,
+                    'parameter_declaration': get_callback_parameter_declaration(operation),
+                    'prepare_js_parameters': '',

[haraken, 2013/07/26 02:03:30]

Drop this in this CL.

+                    'handles': ',\n'.join(['%sHandle' % parameter.name for parameter in operation.arguments]),

[haraken, 2013/07/26 02:03:30]

You don't need to add "\n".

[kojih, 2013/07/26 07:18:38]

ok, but dropped in this CL.

+                    'parameters': parameters,

[haraken, 2013/07/26 02:03:30]

Nit: parameters => arguments

[kojih, 2013/07/26 07:18:38]

ok, but dropped in this CL.

+                    'custom': custom,
+                }
+            functions.append(function)
+        implementation_includes = sort_and_remove_duplicate(implementation_includes)
+        header_includes = sort_and_remove_duplicate(header_includes)
+        template_parameters = {

[haraken, 2013/07/26 02:03:30]

template_parameters => template_contents

+            'interface_name': self.interface.name,
+            'impl_class_name': impl_class_name,
+            'v8_class_name': v8_class_name,
+            'implementation_includes': implementation_includes,
+            'header_includes': header_includes,

[haraken, 2013/07/26 02:03:30]

If header_includes is a set, you can just say: sort(list(header_includes))

+            'functions': functions,

[haraken, 2013/07/26 02:03:30]

functions => methods

As christophe commented in the previous CL, we should use "operation" in the IDL
world and use "method" in the cpp world.

+        }
+        return template_parameters
+
+    def generate_header(self):
+        # TODO: implement

[haraken, 2013/07/26 02:03:30]

TODO => FIXME

+        self.header = ''
+
+    def generate_implementation(self):

[haraken, 2013/07/26 02:03:30]

generate_implementation => generate_cpp

+        # TODO: implement

[haraken, 2013/07/26 02:03:30]

TODO => FIXME

+        self.implementation = ''
 
 
 def generate_dummy_header_and_cpp(target_interface_name, output_directory):