Change RegExp syntax to fail on invalid ranges like [\d-x], [x-\d] and [\d-\d].

src/parser.cc

 // 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 4386 matching lines @@
   } else {
     Advance();
     return CharacterRange::Singleton(first);
   }
 }
 
 
 RegExpTree* RegExpParser::ParseCharacterClass() {
   static const char* kUnterminated = "Unterminated character class";
   static const char* kRangeOutOfOrder = "Range out of order in character class";
+  static const char* kInvalidRange = "Invalid character range";
 
   ASSERT_EQ(current(), '[');
   Advance();
   bool is_negated = false;
   if (current() == '^') {
     is_negated = true;
     Advance();
   }
+  // A CharacterClass is a sequence of single characters, character class
+  // escapes or ranges. Ranges are on the form "x-y" where x and y are
+  // single characters (and not character class escapes like \s).
+  // A "-" may occur at the start or end of the character class (just after
+  // "[" or "[^", or just before "]") without being considered part of a
+  // range. A "-" may also appear as the beginning or end of a range.
+  // I.e., [--+] is valid, so is [!--].
+
   ZoneList<CharacterRange>* ranges = new ZoneList<CharacterRange>(2);
   while (has_more() && current() != ']') {
     uc16 char_class = 0;
     CharacterRange first = ParseClassAtom(&char_class CHECK_FAILED);
     if (char_class) {
       CharacterRange::AddClassEscape(char_class, ranges);
+      if (current() == '-') {
+        Advance();
+        ranges->Add(CharacterRange::Singleton('-'));
+        if (current() != ']') {
+          ReportError(CStrVector(kInvalidRange) CHECK_FAILED);
+        }
+        break;
+      }
       continue;
     }
     if (current() == '-') {
       Advance();
       if (current() == kEndMarker) {
         // If we reach the end we break out of the loop and let the
         // following code report an error.
         break;
       } else if (current() == ']') {
         ranges->Add(first);
         ranges->Add(CharacterRange::Singleton('-'));
         break;
       }
       CharacterRange next = ParseClassAtom(&char_class CHECK_FAILED);
       if (char_class) {
-        ranges->Add(first);
-        ranges->Add(CharacterRange::Singleton('-'));
-        CharacterRange::AddClassEscape(char_class, ranges);
-        continue;
+        ReportError(CStrVector(kInvalidRange) CHECK_FAILED);
       }
       if (first.from() > next.to()) {
         return ReportError(CStrVector(kRangeOutOfOrder) CHECK_FAILED);
       }
       ranges->Add(CharacterRange::Range(first.from(), next.to()));
     } else {
       ranges->Add(first);
     }
   }
   if (!has_more()) {
@@ skipping 186 matching lines @@
       Handle<String> source = Handle<String>(String::cast(script->source()));
       result = parser.ParseProgram(source, info->is_global());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal