Implement generator support for extension fields (no encoder/decoder support yet)

generator/nanopb_generator.py

@@ -275,8 +275,53 @@ class Field:
         return max(self.tag, self.max_size, self.max_count)        
 
 
+class ExtensionRange(Field):
+    def __init__(self, struct_name, desc, field_options):
+        '''desc is ExtensionRange'''
+        self.tag = desc.start
+        self.struct_name = struct_name
+        self.name = 'extensions'
+        self.pbtype = 'EXTENSION'
+        self.rules = 'OPTIONAL'
+        self.allocation = 'CALLBACK'
+        self.ctype = 'pb_extension_t'
+        self.array_decl = ''
+        self.default = None
+        self.max_size = 0
+        self.max_count = 0
+        
+    def __str__(self):
+        return '    pb_extension_t *extensions;'
+    
+    def types(self):
+        return None
+    
+    def tags(self):
+        return ''
 
+class ExtensionField(Field):
+    def __init__(self, struct_name, desc, field_options):
+        self.fullname = struct_name + desc.name
+        self.extendee_name = names_from_type_name(desc.extendee)
+        Field.__init__(self, self.fullname + 'struct', desc, field_options)
 
+    def extension_decl(self):
+        '''Declaration of the extension type in the .pb.h file'''
+        return 'extern const pb_extension_type_t %s;' % self.fullname
+
+    def extension_def(self):
+        '''Definition of the extension type in the .pb.c file'''
+        result  = 'typedef struct {\n'
+        result += str(self)
+        result += '} %s;\n' % self.struct_name
+        result += ('static const pb_field_t %s_field = %s;\n' %
+                    (self.fullname, self.pb_field_t(None)))
+        result += 'const pb_extension_type_t %s = {\n' % self.fullname
+        result += '    NULL,\n'
+        result += '    NULL,\n'
+        result += '    &%s_field\n' % self.fullname
+        result += '};\n'
+        return result
 
 
 # ---------------------------------------------------------------------------
@@ -294,6 +339,11 @@ class Message:
             if field_options.type != nanopb_pb2.FT_IGNORE:
                 self.fields.append(Field(self.name, f, field_options))
         
+        if len(desc.extension_range) > 0:
+            field_options = get_nanopb_suboptions(desc, message_options, self.name + 'extensions')
+            if field_options.type != nanopb_pb2.FT_IGNORE:
+                self.fields.append(ExtensionRange(self.name, desc.extension_range[0], field_options))
+        
         self.packed = message_options.packed_struct
         self.ordered_fields = self.fields[:]
         self.ordered_fields.sort()
@@ -358,9 +408,6 @@ class Message:
 
 
 
-
-
-
 # ---------------------------------------------------------------------------
 #                    Processing of entire .proto files
 # ---------------------------------------------------------------------------
@@ -380,11 +427,23 @@ def iterate_messages(desc, names = Names()):
         for x in iterate_messages(submsg, sub_names):
             yield x
 
+def iterate_extensions(desc, names = Names()):
+    '''Recursively find all extensions.
+    For each, yield name, FieldDescriptorProto.
+    '''
+    for extension in desc.extension:
+        yield names, extension
+
+    for subname, subdesc in iterate_messages(desc, names):
+        for extension in subdesc.extension:
+            yield subname, extension
+
 def parse_file(fdesc, file_options):
-    '''Takes a FileDescriptorProto and returns tuple (enum, messages).'''
+    '''Takes a FileDescriptorProto and returns tuple (enums, messages, extensions).'''
     
     enums = []
     messages = []
+    extensions = []
     
     if fdesc.package:
         base_name = Names(fdesc.package.split('.'))
@@ -402,6 +461,10 @@ def parse_file(fdesc, file_options):
             enum_options = get_nanopb_suboptions(enum, message_options, names + enum.name)
             enums.append(Enum(names, enum, enum_options))
     
+    for names, extension in iterate_extensions(fdesc, base_name):
+        field_options = get_nanopb_suboptions(extension, file_options, names)
+        extensions.append(ExtensionField(names, extension, field_options))
+    
     # Fix field default values where enum short names are used.
     for enum in enums:
         if not enum.options.long_names:
@@ -411,7 +474,7 @@ def parse_file(fdesc, file_options):
                         idx = enum.value_longnames.index(field.default)
                         field.default = enum.values[idx][0]
     
-    return enums, messages
+    return enums, messages, extensions
 
 def toposort2(data):
     '''Topological sort.
@@ -454,7 +517,7 @@ def make_identifier(headername):
             result += '_'
     return result
 
-def generate_header(dependencies, headername, enums, messages, options):
+def generate_header(dependencies, headername, enums, messages, extensions, options):
     '''Generate content for a header file.
     Generates strings, which should be concatenated and stored to file.
     '''
@@ -489,6 +552,12 @@ def generate_header(dependencies, headername, enums, messages, options):
     for msg in sort_dependencies(messages):
         yield msg.types()
         yield str(msg) + '\n\n'
+    
+    if extensions:
+        yield '/* Extensions */\n'
+        for extension in extensions:
+            yield extension.extension_decl()
+        yield '\n'
         
     yield '/* Default values for struct fields */\n'
     for msg in messages:
@@ -512,7 +581,7 @@ def generate_header(dependencies, headername, enums, messages, options):
     # End of header
     yield '\n#endif\n'
 
-def generate_source(headername, enums, messages):
+def generate_source(headername, enums, messages, extensions):
     '''Generate content for a source file.'''
     
     yield '/* Automatically generated nanopb constant definitions */\n'
@@ -527,7 +596,11 @@ def generate_source(headername, enums, messages):
     
     for msg in messages:
         yield msg.fields_definition() + '\n\n'
+    
+    for ext in extensions:
+        yield ext.extension_def() + '\n'
         
+    # Add checks for numeric limits
     if messages:
         count_required_fields = lambda m: len([f for f in msg.fields if f.rules == 'REQUIRED'])
         largest_msg = max(messages, key = count_required_fields)
@@ -539,7 +612,6 @@ def generate_source(headername, enums, messages):
             yield '       setting PB_MAX_REQUIRED_FIELDS to %d or more.\n' % largest_count
             yield '#endif\n'
     
-    # Add checks for numeric limits
     worst = 0
     worst_field = ''
     checks = []
@@ -724,7 +796,7 @@ def process(filenames, options):
         
         # Parse the file
         file_options = get_nanopb_suboptions(fdesc.file[0], toplevel_options, Names([filename]))
-        enums, messages = parse_file(fdesc.file[0], file_options)
+        enums, messages, extensions = parse_file(fdesc.file[0], file_options)
         
         noext = os.path.splitext(filename)[0]
         headername = noext + '.' + options.extension + '.h'
@@ -740,11 +812,12 @@ def process(filenames, options):
         dependencies = [d for d in fdesc.file[0].dependency if d not in excludes]
         
         header = open(headername, 'w')
-        for part in generate_header(dependencies, headerbasename, enums, messages, options):
+        for part in generate_header(dependencies, headerbasename, enums,
+                                    messages, extensions, options):
             header.write(part)
 
         source = open(sourcename, 'w')
-        for part in generate_source(headerbasename, enums, messages):
+        for part in generate_source(headerbasename, enums, messages, extensions):
             source.write(part)
 
     return True