idl parser: Update IDL parser to accept interface mixin

interface mixin is a new IDL feature, and has a new grammar definition.
This CL updates IDL parser to accept it.
https://heycam.github.io/webidl/#idl-interface-mixins

Bug: 781257
Change-Id: Ibb771007c9147cf868995c80db8afc4ca43b9a74
Reviewed-on: https://chromium-review.googlesource.com/954763
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541753}

tools/idl_parser/idl_lexer.py

@@ -79,6 +79,7 @@ class IDLLexer(object):
     'legacycaller' : 'LEGACYCALLER',
     'long' : 'LONG',
     'maplike': 'MAPLIKE',
+    'mixin': 'MIXIN',
     'namespace' : 'NAMESPACE',
     'Nan' : 'NAN',
     'null' : 'NULL',

tools/idl_parser/idl_parser.py

@@ -253,7 +253,7 @@ def p_Definitions(self, p):
       p[0] = ListFromConcat(p[2], p[3])
 
   def p_Definition(self, p):
-    """Definition : CallbackOrInterface
+    """Definition : CallbackOrInterfaceOrMixin
                   | Namespace
                   | Partial
                   | Dictionary
@@ -267,28 +267,32 @@ def p_DefinitionError(self, p):
     """Definition : error ';'"""
     p[0] = self.BuildError(p, 'Definition')
 
-  def p_CallbackOrInterface(self, p):
-    """CallbackOrInterface : CALLBACK CallbackRestOrInterface
-                           | Interface"""
-    if len(p) > 2:
-      if p[2].GetClass() != 'Callback':
-        p[2].AddChildren(self.BuildTrue('CALLBACK'))
-      p[0] = p[2]
-    else:
-      p[0] = p[1]
+  def p_CallbackOrInterfaceOrMixin(self, p):
+    """CallbackOrInterfaceOrMixin : CALLBACK CallbackRestOrInterface
+                                  | INTERFACE InterfaceOrMixin"""
+    p[0] = p[2]
 
   def p_CallbackRestOrInterface(self, p):
     """CallbackRestOrInterface : CallbackRest
-                               | Interface"""
+                               | INTERFACE InterfaceRest"""
+    if len(p) < 3:
+      p[0] = p[1]
+    else:
+      p[2].AddChildren(self.BuildTrue('CALLBACK'))
+      p[0] = p[2]
+
+  def p_InterfaceOrMixin(self, p):
+    """InterfaceOrMixin : InterfaceRest
+                        | MixinRest"""
     p[0] = p[1]
 
-  def p_Interface(self, p):
-    """Interface : INTERFACE identifier Inheritance '{' InterfaceMembers '}' ';'"""
-    p[0] = self.BuildNamed('Interface', p, 2, ListFromConcat(p[3], p[5]))
+  def p_InterfaceRest(self, p):
+    """InterfaceRest : identifier Inheritance '{' InterfaceMembers '}' ';'"""
+    p[0] = self.BuildNamed('Interface', p, 1, ListFromConcat(p[2], p[4]))
 
   # Error recovery for interface.
-  def p_InterfaceError(self, p):
-    """Interface : INTERFACE identifier Inheritance '{' error"""
+  def p_InterfaceRestError(self, p):
+    """InterfaceRest : identifier Inheritance '{' error"""
     p[0] = self.BuildError(p, 'Interface')
 
   def p_Partial(self, p):
@@ -337,6 +341,29 @@ def p_InterfaceMember(self, p):
                        | ReadWriteSetlike"""
     p[0] = p[1]
 
+  def p_MixinRest(self, p):
+    """MixinRest : MIXIN identifier '{' MixinMembers '}' ';'"""
+    p[0] = self.BuildNamed('InterfaceMixin', p, 2, p[4])
+
+  def p_MixinMembers(self, p):
+    """MixinMembers : ExtendedAttributeList MixinMember MixinMembers
+                    |"""
+    if len(p) > 1:
+      p[2].AddChildren(p[1])
+      p[0] = ListFromConcat(p[2], p[3])
+
+  # Error recovery for InterfaceMembers
+  def p_MixinMembersError(self, p):
+    """MixinMembers : error"""
+    p[0] = self.BuildError(p, 'MixinMembers')
+
+  def p_MixinMember(self, p):
+    """MixinMember : Const
+                   | Operation
+                   | Stringifier
+                   | ReadonlyMember"""
+    p[0] = p[1]
+
   def p_Dictionary(self, p):
     """Dictionary : DICTIONARY identifier Inheritance '{' DictionaryMembers '}' ';'"""
     p[0] = self.BuildNamed('Dictionary', p, 2, ListFromConcat(p[3], p[5]))

tools/idl_parser/idl_parser_test.py

@@ -25,7 +25,7 @@ def setUp(self):
         os.path.join(os.path.dirname(__file__), 'test_parser'))
     self.filenames = glob.glob('%s/*_web.idl' % test_dir)
 
-  def _TestNode(self, node):
+  def _TestNode(self, node, filepath):
     comments = node.GetListOf('SpecialComment')
     for comment in comments:
       check, value = ParseCommentTest(comment.GetName())
@@ -37,7 +37,7 @@ def _TestNode(self, node):
       if check == 'TREE':
         quick = '\n'.join(node.Tree())
         lineno = node.GetProperty('LINENO')
-        msg = 'Mismatched tree at line %d:' % lineno
+        msg = 'Mismatched tree at line %d in %s:' % (lineno, filepath)
         msg += '\n\n[EXPECTED]\n%s\n\n[ACTUAL]\n%s\n' % (value, quick)
         self.assertEqual(value, quick, msg)
 
@@ -49,7 +49,7 @@ def testExpectedNodes(self):
           filename)
 
       for node in filenode.GetChildren():
-        self._TestNode(node)
+        self._TestNode(node, filename)
 
 
 class TestImplements(unittest.TestCase):

tools/idl_parser/test_lexer/keywords.in

@@ -23,6 +23,7 @@ ITERABLE iterable
 LEGACYCALLER legacycaller
 LONG long
 MAPLIKE maplike
+MIXIN mixin
 NAN Nan
 NULL null
 OBJECT object

tools/idl_parser/test_parser/interface_web.idl

@@ -42,6 +42,45 @@ partial interface MyIFacePartial { };
 /** ERROR Unexpected ":" after identifier "MyIFaceInherit". */
 partial interface MyIFaceInherit : Foo {};
 
+/** TREE
+ *InterfaceMixin(IFaceMixin)
+ */
+interface mixin IFaceMixin {};
+
+/** ERROR Unexpected ":" after identifier "IFaceMixinInherit". */
+interface mixin IFaceMixinInherit : Foo {};
+
+/** ERROR Unexpected keyword "mixin" after keyword "interface". */
+partial interface mixin PartialIFaceMixin {};
+
+/** TREE
+ *InterfaceMixin(IFaceMixin)
+ *  Error(Unexpected keyword "static" after "{".)
+ */
+interface mixin IFaceMixin {
+  static attribute integer staticAttribute;
+};
+
+/** TREE
+ *InterfaceMixin(IFaceMixin)
+ *  Const(pi)
+ *    PrimitiveType(double)
+ *    Value() = "3.14159"
+ *  Operation(foo)
+ *    Arguments()
+ *    Type()
+ *      PrimitiveType(void)
+ *  Attribute(bar)
+ *    READONLY: True
+ *    Type()
+ *      StringType(DOMString)
+ */
+interface mixin IFaceMixin {
+  const double pi = 3.14159;
+  void foo();
+  readonly attribute DOMString bar;
+};
+
 /** TREE
  *Interface(MyIFaceMissingArgument)
  *  Operation(foo)