Mojo: Mojom: Add AST types for imports and import lists.

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

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates a syntax tree from a Mojo IDL file."""
 
 import imp
 import os.path
 import sys
 
@@ skipping 69 matching lines @@
   # where N is a number (numbered starting from 1). Note that using multiple
   # functions is actually more efficient than having single functions handle
   # multiple rules (and, e.g., distinguishing them by examining |len(p)|).
   #
   # It's also possible to have a function handling multiple rules with different
   # left-hand-sides. We do not do this.
   #
   # See http://www.dabeaz.com/ply/ply.html#ply_nn25 for more details.
 
   # TODO(vtl): Get rid of this ('MODULE', ...) stuff and replace it with an
-  # ast.Mojom node. This will require putting the imports into a list (say
-  # ast.ImportList).
+  # ast.Mojom node. (The ('IMPORT', ...) stuff is a hack until I do this and
+  # update translate.py.)
   # TODO(vtl): Get rid of the braces in the module "statement". (Consider
   # renaming "module" -> "package".)
   def p_root(self, p):
-    """root : import root
-            | module LBRACE definition_list RBRACE
-            | definition_list"""
-    if len(p) == 3:
-      p[0] = p[2]
-      p[0].insert(0, p[1])
-    elif len(p) == 5:
-      p[0] = [('MODULE', p[1].name, p[1].attribute_list, p[3])]
+    """root : import_list module LBRACE definition_list RBRACE
+            | import_list definition_list"""
+    p[0] = [('IMPORT', import_statement.import_filename) \
+                for import_statement in p[1]]
+    if len(p) == 6:
+      p[0].append(('MODULE', p[2].name, p[2].attribute_list, p[4]))
     else:
-      p[0] = [('MODULE', None, None, p[1])]
+      p[0].append(('MODULE', None, None, p[2]))
+
+  def p_import_list_1(self, p):
+    """import_list : """
+    p[0] = ast.ImportList()
+
+  def p_import_list_2(self, p):
+    """import_list : import_list import"""
+    p[0] = p[1]
+    p[0].Append(p[2])
 
   def p_import(self, p):
     """import : IMPORT STRING_LITERAL"""
     # 'eval' the literal to strip the quotes.
-    p[0] = ('IMPORT', eval(p[2]))
+    # TODO(vtl): This eval is dubious. We should unquote/unescape ourselves.
+    p[0] = ast.Import(eval(p[2]))
 
   def p_module(self, p):
     """module : attribute_section MODULE identifier_wrapped """
     p[0] = ast.Module(p[3], p[1], filename=self.filename, lineno=p.lineno(2))
 
   def p_definition_list(self, p):
     """definition_list : definition definition_list
                        | """
     if len(p) > 1:
       p[0] = _ListFromConcat(p[1], p[2])
@@ skipping 247 matching lines @@
 
 def Parse(source, filename):
   lexer = Lexer(filename)
   parser = Parser(lexer, source, filename)
 
   lex.lex(object=lexer)
   yacc.yacc(module=parser, debug=0, write_tables=0)
 
   tree = yacc.parse(source)
   return tree