mojo: Start generating structs for python bindings

mojo/public/python/mojo/bindings/reflection.py

Index: mojo/public/python/mojo/bindings/reflection.py
diff --git a/mojo/public/python/mojo/bindings/reflection.py b/mojo/public/python/mojo/bindings/reflection.py
index d7ba5241122a51dc79a48577ae68c215eac12bf7..5ee2c1dd0eec03afea0198265ce73692baa4c7ca 100644
--- a/mojo/public/python/mojo/bindings/reflection.py
+++ b/mojo/public/python/mojo/bindings/reflection.py
@@ -18,6 +18,7 @@ class MojoEnumType(type):
 
       This will define a enum with 3 values, A = 0, B = 1 and C = 5.
   """
+
   def __new__(mcs, name, bases, dictionary):
     class_members = {
       '__new__': None,
@@ -37,3 +38,55 @@ class MojoEnumType(type):
 
   def __delattr__(mcs, key):
     raise AttributeError, 'can\'t delete attribute'
+
+
+class MojoStructType(type):
+  """Meta class for structs.
+
+  Usage:
+    class MyStruct(object):
+      __metaclass__ = MojoStructType
+      DESCRIPTOR = {
+        'constants': {
+          'C1': 1,
+          'C2': 2,
+        },
+        'enums': {
+          'ENUM1': [
+            ('V1', 1),
+            'V2',
+          ],
+          'ENUM2': [
+            ('V1', 1),
+            'V2',
+          ],
+        },
+      }
+
+      This will define an struct, with 2 constants C1 and C2, and 2 enums ENUM1
+      and ENUM2, each of those having 2 values, V1 and V2.
+  """
+
+  def __new__(mcs, name, bases, dictionary):
+    class_members = {
+      '__slots__': [],

[sdefresne, 2014/09/09 08:51:57]

nit: maybe you want to keep the __module__ here from dictionary.

[qsr, 2014/09/09 08:55:10]

 I fixed all of this in the following CL
(https://chromiumcodereview.appspot.com/551053002/), I can backport it here
directly if you prefer.

[sdefresne, 2014/09/09 09:30:36]

Ok, no need to backport.

+    }
+    descriptor = dictionary.pop('DESCRIPTOR', {})
+
+    # Add constants
+    class_members.update(descriptor.get('constants', {}))
+
+    # Add enums
+    enums = descriptor.get('enums', {})
+    for key in enums:
+      class_members[key] = MojoEnumType(key,
+                                        (object,),
+                                        { 'VALUES': enums[key] })
+
+    return type.__new__(mcs, name, bases, class_members)
+
+  def __setattr__(mcs, key, value):
+    raise AttributeError, 'can\'t set attribute'
+
+  def __delattr__(mcs, key):
+    raise AttributeError, 'can\'t delete attribute'