Experimental lexer: add handling of sliced strings in SubStringKey

src/objects-inl.h

 // Copyright 2012 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 485 matching lines @@
   }
 
   virtual MaybeObject* AsObject(Heap* heap);
 };
 
 
 template<class Char>
 class SubStringKey : public HashTableKey {
  public:
   SubStringKey(Handle<String> string, int from, int length)
-      : string_(string), from_(from), length_(length) { }
+      : string_(string), from_(from), length_(length) {
+    if (string_->IsSlicedString()) {
+      string_ = Handle<String>(Unslice(*string_, &from_));
+    }
+    ASSERT(string_->IsSeqString() || string->IsExternalString());
+  }
 
   virtual uint32_t Hash() {
     ASSERT(length_ >= 0);
     ASSERT(from_ + length_ <= string_->length());
     const Char* chars = GetChars() + from_;
     hash_field_ = StringHasher::HashSequentialString(
         chars, length_, string_->GetHeap()->HashSeed());
     uint32_t result = hash_field_ >> String::kHashShift;
     ASSERT(result != 0);  // Ensure that the hash value of 0 is never computed.
     return result;
   }
 
   virtual uint32_t HashForObject(Object* other) {
     return String::cast(other)->Hash();
   }
 
   virtual bool IsMatch(Object* string);
   virtual MaybeObject* AsObject(Heap* heap);
 
  private:
   const Char* GetChars();
+  String* Unslice(String* string, int* offset) {
+    while (string->IsSlicedString()) {
+      SlicedString* sliced = SlicedString::cast(string);
+      *offset += sliced->offset();
+      string = sliced->parent();
+    }
+    return string;
+  }
 
   Handle<String> string_;
   int from_;
   int length_;
   uint32_t hash_field_;
 };
 
 
 class TwoByteStringKey : public SequentialStringKey<uc16> {
  public:
@@ skipping 6252 matching lines @@
 #undef READ_UINT32_FIELD
 #undef WRITE_UINT32_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_