Flat string reader

src/jsregexp.cc

 // Copyright 2006-2008 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 190 matching lines @@
                                    Handle<String> flag_str) {
   JSRegExp::Flags flags = RegExpFlagsFromString(flag_str);
   Handle<FixedArray> cached = CompilationCache::LookupRegExp(pattern, flags);
   bool in_cache = !cached.is_null();
   Handle<Object> result;
   StringShape shape(*pattern);
   if (in_cache) {
     re->set_data(*cached);
     result = re;
   } else {
-    SafeStringInputBuffer buffer(pattern.location());
+    pattern->Flatten(shape);

[Erik Corry, 2008/11/19 09:45:38]

Since this shape is only used once I think you should just make it in the
Flatten call.  This also avoids the subtlety around the fact that flattening a
string changes its shape, so the shape can't be reused again anyway.

     RegExpParseResult parse_result;
-    if (!ParseRegExp(&buffer, &parse_result)) {
+    FlatStringReader reader(pattern);
+    if (!ParseRegExp(&reader, &parse_result)) {
       // Throw an exception if we fail to parse the pattern.
       ThrowRegExpException(re,
                            pattern,
                            parse_result.error,
                            "malformed_regexp");
       return Handle<Object>();
     }
     RegExpAtom* atom = parse_result.tree->AsAtom();
     if (atom != NULL && !flags.is_ignore_case()) {
       if (parse_result.has_character_escapes) {
@@ skipping 1841 matching lines @@
 }
 
 RegExpMacroAssembler::RegExpMacroAssembler() {
 }
 
 RegExpMacroAssembler::~RegExpMacroAssembler() {
 }
 
 
 }}  // namespace v8::internal