Strict mode parameter validation.

src/scanner-base.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 253 matching lines @@
 
   // Returns the current token again.
   Token::Value current_token() { return current_.token; }
 
   // One token look-ahead (past the token returned by Next()).
   Token::Value peek() const { return next_.token; }
 
   struct Location {
     Location(int b, int e) : beg_pos(b), end_pos(e) { }
     Location() : beg_pos(0), end_pos(0) { }
+
+    bool IsValid() const {
+      return beg_pos >= 0 && end_pos >= 0;

[Lasse Reichstein, 2011/01/25 13:03:55]

How about ... && end_pos >= beg_pos;
Seems more "valid" to me :)

[Martin Maly, 2011/01/25 17:21:25]

Done. Using beg_pos >= 0 && end_pos >= beg_pos

because end_pos >= beg_pos >= 0 ===> end_pos >= 0

+    }
+
     int beg_pos;
     int end_pos;
   };
 
+  static Location NoLocation() {
+    return Location(-1, -1);
+  }
+
   // Returns the location information for the current token
   // (the token returned by Next()).
   Location location() const { return current_.location; }
   Location peek_location() const { return next_.location; }
 
   // Returns the literal string, if any, for the current token (the
   // token returned by Next()). The string is 0-terminated and in
   // UTF-8 format; they may contain 0-characters. Literal strings are
   // collected for identifiers, strings, and numbers.
   // These functions only give the correct result if the literal
@@ skipping 329 matching lines @@
   // keyword with the current prefix).
   const char* keyword_;
   int counter_;
   Token::Value keyword_token_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_BASE_H_