Remove internalized cons string types.

Currently, internalizing a cons string could result in either an
in-place converted internalized cons string or a newly created
internalized sequential string, depending on allocation success.

The former could end up being embedded into an IC, which is not
supported.

R=mstarzinger@chromium.org
BUG=357103
LOG=N

Review URL: https://codereview.chromium.org/218993011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20394 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -4964,8 +4964,6 @@ Map* Heap::InternalizedStringMapForString(String* string) {
   switch (string->map()->instance_type()) {
     case STRING_TYPE: return internalized_string_map();
     case ASCII_STRING_TYPE: return ascii_internalized_string_map();
-    case CONS_STRING_TYPE: return cons_internalized_string_map();
-    case CONS_ASCII_STRING_TYPE: return cons_ascii_internalized_string_map();
     case EXTERNAL_STRING_TYPE: return external_internalized_string_map();
     case EXTERNAL_ASCII_STRING_TYPE:
       return external_ascii_internalized_string_map();

src/objects.cc

@@ -13872,9 +13872,6 @@ class InternalizedStringKey : public HashTableKey {
   }
 
   MaybeObject* AsObject(Heap* heap) {
-    // Attempt to flatten the string, so that internalized strings will most
-    // often be flat strings.
-    string_ = string_->TryFlattenGetString();
     // Internalize the string if possible.
     Map* map = heap->InternalizedStringMapForString(string_);
     if (map != NULL) {

src/objects.h

@@ -355,8 +355,6 @@ const int kStubMinorKeyBits = kBitsPerInt - kSmiTagSize - kStubMajorKeyBits;
                                                                                \
   V(INTERNALIZED_STRING_TYPE)                                                  \
   V(ASCII_INTERNALIZED_STRING_TYPE)                                            \
-  V(CONS_INTERNALIZED_STRING_TYPE)                                             \
-  V(CONS_ASCII_INTERNALIZED_STRING_TYPE)                                       \
   V(EXTERNAL_INTERNALIZED_STRING_TYPE)                                         \
   V(EXTERNAL_ASCII_INTERNALIZED_STRING_TYPE)                                   \
   V(EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE)                      \
@@ -514,14 +512,6 @@ const int kStubMinorKeyBits = kBitsPerInt - kSmiTagSize - kStubMajorKeyBits;
     kVariableSizeSentinel,                                                     \
     ascii_internalized_string,                                                 \
     AsciiInternalizedString)                                                   \
-  V(CONS_INTERNALIZED_STRING_TYPE,                                             \
-    ConsString::kSize,                                                         \
-    cons_internalized_string,                                                  \
-    ConsInternalizedString)                                                    \
-  V(CONS_ASCII_INTERNALIZED_STRING_TYPE,                                       \
-    ConsString::kSize,                                                         \
-    cons_ascii_internalized_string,                                            \
-    ConsAsciiInternalizedString)                                               \
   V(EXTERNAL_INTERNALIZED_STRING_TYPE,                                         \
     ExternalTwoByteString::kSize,                                              \
     external_internalized_string,                                              \
@@ -662,10 +652,6 @@ enum InstanceType {
       | kInternalizedTag,
   ASCII_INTERNALIZED_STRING_TYPE = kOneByteStringTag | kSeqStringTag
       | kInternalizedTag,
-  CONS_INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kConsStringTag
-      | kInternalizedTag,
-  CONS_ASCII_INTERNALIZED_STRING_TYPE = kOneByteStringTag | kConsStringTag
-      | kInternalizedTag,
   EXTERNAL_INTERNALIZED_STRING_TYPE = kTwoByteStringTag | kExternalStringTag
       | kInternalizedTag,
   EXTERNAL_ASCII_INTERNALIZED_STRING_TYPE = kOneByteStringTag
@@ -685,9 +671,9 @@ enum InstanceType {
 
   STRING_TYPE = INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
   ASCII_STRING_TYPE = ASCII_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
-  CONS_STRING_TYPE = CONS_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
+  CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag | kNotInternalizedTag,
   CONS_ASCII_STRING_TYPE =
-      CONS_ASCII_INTERNALIZED_STRING_TYPE | kNotInternalizedTag,
+      kOneByteStringTag | kConsStringTag | kNotInternalizedTag,
 
   SLICED_STRING_TYPE =
       kTwoByteStringTag | kSlicedStringTag | kNotInternalizedTag,

src/types.cc

@@ -169,8 +169,6 @@ int TypeImpl<Config>::LubBitset(i::Map* map) {
     case SHORT_EXTERNAL_STRING_WITH_ONE_BYTE_DATA_TYPE:
     case INTERNALIZED_STRING_TYPE:
     case ASCII_INTERNALIZED_STRING_TYPE:
-    case CONS_INTERNALIZED_STRING_TYPE:
-    case CONS_ASCII_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_ASCII_INTERNALIZED_STRING_TYPE:
     case EXTERNAL_INTERNALIZED_STRING_WITH_ONE_BYTE_DATA_TYPE:

test/mjsunit/regress/regress-357103.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+%SetFlags("--gc-interval=1");
+
+var key = "Huckleberry Finn" + "Tom Sawyer";
+var o = {};
+function f() { o[key] = "Adventures"; }
+
+f();
+f();