Changes around ascii-check for strings wrt external strings.

src/objects-inl.h

 // Copyright 2011 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 272 matching lines @@
 bool String::IsAsciiRepresentationUnderneath() {
   uint32_t type = map()->instance_type();
   STATIC_ASSERT(kIsIndirectStringTag != 0);
   STATIC_ASSERT((kIsIndirectStringMask & kStringEncodingMask) == 0);
   ASSERT(IsFlat());
   switch (type & (kIsIndirectStringMask | kStringEncodingMask)) {
     case kAsciiStringTag:
       return true;
     case kTwoByteStringTag:
       return false;
-    default:  // Cons or sliced string.  Need to go deeper.
-      return GetUnderlying()->IsAsciiRepresentation();
+    default:
+      // Cons or sliced string.  Need to go deeper.
+      // Consider slice of cons of externalized.
+      return GetUnderlying()->IsAsciiRepresentationUnderneath();

[Erik Corry, 2011/10/17 12:05:15]

Is it possible to make an arbitraryly deep nesting of a cons of a slice of a
cons of a slice of a...?  If so this risks recursing too deep.

   }
 }
 
 
 bool String::IsTwoByteRepresentationUnderneath() {
   uint32_t type = map()->instance_type();
   STATIC_ASSERT(kIsIndirectStringTag != 0);
   STATIC_ASSERT((kIsIndirectStringMask & kStringEncodingMask) == 0);
   ASSERT(IsFlat());
   switch (type & (kIsIndirectStringMask | kStringEncodingMask)) {
@@ skipping 4332 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_