gn: Enforce braces after 'else'

tools/gn/parser.cc

Index: tools/gn/parser.cc
diff --git a/tools/gn/parser.cc b/tools/gn/parser.cc
index d99b574c073cb9776066d638c83f1414d0800c49..4acd510328b0e3dd5df631036dfc6b26af25aa66 100644
--- a/tools/gn/parser.cc
+++ b/tools/gn/parser.cc
@@ -499,8 +499,13 @@ scoped_ptr<ParseNode> Parser::ParseCondition() {
     *err_ = Err(condition->condition(), "Assignment not allowed in 'if'.");
   Consume(Token::RIGHT_PAREN, "Expected ')' after condition of 'if'.");
   condition->set_if_true(ParseBlock().Pass());
-  if (Match(Token::ELSE))
+  if (Match(Token::ELSE)) {
+    if (!LookAhead(Token::LEFT_BRACE) && !LookAhead(Token::IF)) {

[tfarina, 2015/03/10 20:37:24]

|| here does the wrong thing?

Anyway, thanks for figuring out this!

[scottmg, 2015/03/10 21:21:00]

I'm not sure what you mean. Right now it says "if it's not a left brace, and
it's not an if" then error out. An "or" there would always go into the error
condition because it can only be one of those two things.
 

+      *err_ = Err(cur_token(), "Expected '{' or 'if' after 'else'.");
+      return scoped_ptr<ParseNode>();

[tfarina, 2015/03/10 20:37:24]

This can be return nullptr;

[scottmg, 2015/03/10 21:21:00]

There's a whole bunch that predate nullptr in this file. I don't want to change
them all in this CL, so I'm going to leave it like this and they can all be
changed together separately.

+    }
     condition->set_if_false(ParseStatement().Pass());
+  }
   if (has_error())
     return scoped_ptr<ParseNode>();
   return condition.Pass();