Mojo: Mojom: Add a Parameter object to the AST.

Also add a basic parser test for interfaces/methods. (I also verified
that the change does not affect the output of the generators on any
.mojom file under mojo/.)

R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/365773002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@281040 0039d316-1c4b-4281-b951-d872f2087c98

mojo/public/tools/bindings/pylib/mojom/parse/ast.py

@@ -23,3 +23,17 @@ def __init__(self, value, **kwargs):
 
   def __eq__(self, other):
     return self.value == other.value
+
+class Parameter(BaseNode):
+  """Represents a method request or response parameter."""
+  def __init__(self, typename, name, ordinal, **kwargs):
+    assert isinstance(ordinal, Ordinal)
+    BaseNode.__init__(self, **kwargs)
+    self.typename = typename
+    self.name = name
+    self.ordinal = ordinal
+
+  def __eq__(self, other):
+    return self.typename == other.typename and \
+           self.name == other.name and \
+           self.ordinal == other.ordinal

mojo/public/tools/bindings/pylib/mojom/parse/parser.py

@@ -183,13 +183,14 @@ def p_parameters(self, p):
     if len(p) == 1:
       p[0] = []
     elif len(p) == 2:
-      p[0] = _ListFromConcat(p[1])
-    elif len(p) > 3:
-      p[0] = _ListFromConcat(p[1], p[3])
+      p[0] = [p[1]]
+    else:
+      p[0] = [p[1]] + p[3]
 
   def p_parameter(self, p):
     """parameter : typename NAME ordinal"""
-    p[0] = ('PARAM', p[1], p[2], p[3])
+    p[0] = ast.Parameter(p[1], p[2], p[3],
+                         filename=self.filename, lineno=p.lineno(1))
 
   def p_typename(self, p):
     """typename : basictypename

mojo/public/tools/bindings/pylib/mojom/parse/translate.py

@@ -66,26 +66,27 @@ def _GetAttribute(attributes, name):
   return out
 
 def _MapField(tree):
-  assert type(tree[3]) is ast.Ordinal
+  assert isinstance(tree[3], ast.Ordinal)
   return {'name': tree[2],
           'kind': _MapKind(tree[1]),
           'ordinal': tree[3].value,
           'default': tree[4]}
 
-def _MapParameter(tree):
-  assert type(tree[3]) is ast.Ordinal
-  return {'name': tree[2],
-          'kind': _MapKind(tree[1]),
-          'ordinal': tree[3].value}
-
 def _MapMethod(tree):
-  assert type(tree[3]) is ast.Ordinal
+  def ParameterToDict(param):
+    assert isinstance(param, ast.Parameter)
+    return {'name': param.name,
+            'kind': _MapKind(param.typename),
+            'ordinal': param.ordinal.value}
+
+  assert isinstance(tree[2], list)
+  assert isinstance(tree[3], ast.Ordinal)
   method = {'name': tree[1],
-            'parameters': _MapTree(_MapParameter, tree[2], 'PARAM'),
+            'parameters': map(ParameterToDict, tree[2]),
             'ordinal': tree[3].value}
   # Note: |tree[4]| may be an empty list, indicating a parameter-less response.
   if tree[4] is not None:
-    method['response_parameters'] = _MapTree(_MapParameter, tree[4], 'PARAM')
+    method['response_parameters'] = map(ParameterToDict, tree[4])
   return method
 
 def _MapEnumField(tree):

mojo/public/tools/bindings/pylib/mojom_tests/parse/parser_unittest.py

@@ -560,5 +560,72 @@ def testInvalidFixedArraySize(self):
         r"^my_file\.mojom:2: Error: Unexpected 'abcdefg':"):
       parser.Parse(source3, "my_file.mojom")
 
+  def testValidMethod(self):
+    """Tests parsing method declarations."""
+    source1 = """\
+interface MyInterface {
+  MyMethod(int32 a);
+};
+"""
+    expected1 = \
+[('MODULE',
+  '',
+  None,
+  [('INTERFACE',
+    'MyInterface',
+    None,
+    [('METHOD',
+      'MyMethod',
+      [ast.Parameter('int32', 'a', ast.Ordinal(None))],
+      ast.Ordinal(None),
+      None)])])]
+    self.assertEquals(parser.Parse(source1, "my_file.mojom"), expected1)
+
+    source2 = """\
+interface MyInterface {
+  MyMethod1@0(int32 a@0, int64 b@1);
+  MyMethod2@1() => ();
+};
+"""
+    expected2 = \
+[('MODULE',
+  '',
+  None,
+  [('INTERFACE',
+    'MyInterface',
+    None,
+    [('METHOD',
+      'MyMethod1',
+      [ast.Parameter('int32', 'a', ast.Ordinal(0)),
+       ast.Parameter('int64', 'b', ast.Ordinal(1))],
+      ast.Ordinal(0),
+      None),
+     ('METHOD',
+      'MyMethod2',
+      [],
+      ast.Ordinal(1),
+      [])])])]
+    self.assertEquals(parser.Parse(source2, "my_file.mojom"), expected2)
+
+    source3 = """\
+interface MyInterface {
+  MyMethod(string a) => (int32 a, bool b);
+};
+"""
+    expected3 = \
+[('MODULE',
+  '',
+  None,
+  [('INTERFACE',
+    'MyInterface',
+    None,
+    [('METHOD',
+      'MyMethod',
+      [ast.Parameter('string', 'a', ast.Ordinal(None))],
+      ast.Ordinal(None),
+      [ast.Parameter('int32', 'a', ast.Ordinal(None)),
+       ast.Parameter('bool', 'b', ast.Ordinal(None))])])])]
+    self.assertEquals(parser.Parse(source3, "my_file.mojom"), expected3)
+
 if __name__ == "__main__":
   unittest.main()