Revert "Handlify concat string and substring."

src/runtime.cc

 // 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 4369 matching lines @@
     uint16_t char1 = stream1.GetNext();
     uint16_t char2 = stream2.GetNext();
     if (char1 != char2) return Smi::FromInt(char1 - char2);
   }
 
   return Smi::FromInt(str1_length - str2_length);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SubString) {
-  HandleScope scope(isolate);
+  SealHandleScope shs(isolate);
   ASSERT(args.length() == 3);
 
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
+  CONVERT_ARG_CHECKED(String, value, 0);
   int start, end;
   // We have a fast integer-only case here to avoid a conversion to double in
   // the common case where from and to are Smis.
   if (args[1]->IsSmi() && args[2]->IsSmi()) {
     CONVERT_SMI_ARG_CHECKED(from_number, 1);
     CONVERT_SMI_ARG_CHECKED(to_number, 2);
     start = from_number;
     end = to_number;
   } else {
     CONVERT_DOUBLE_ARG_CHECKED(from_number, 1);
     CONVERT_DOUBLE_ARG_CHECKED(to_number, 2);
     start = FastD2IChecked(from_number);
     end = FastD2IChecked(to_number);
   }
   RUNTIME_ASSERT(end >= start);
   RUNTIME_ASSERT(start >= 0);
-  RUNTIME_ASSERT(end <= string->length());
+  RUNTIME_ASSERT(end <= value->length());
   isolate->counters()->sub_string_runtime()->Increment();
-
-  return *isolate->factory()->NewSubString(string, start, end);
+  if (end - start == 1) {
+     return isolate->heap()->LookupSingleCharacterStringFromCode(
+         value->Get(start));
+  }
+  return value->SubString(start, end);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringMatch) {
   HandleScope handles(isolate);
   ASSERT_EQ(3, args.length());
 
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSArray, regexp_info, 2);
@@ skipping 2066 matching lines @@
       args, isolate, isolate->runtime_state()->to_upper_mapping());
 }
 
 
 static inline bool IsTrimWhiteSpace(unibrow::uchar c) {
   return unibrow::WhiteSpace::Is(c) || c == 0x200b || c == 0xfeff;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringTrim) {
-  HandleScope scope(isolate);
+  SealHandleScope shs(isolate);
   ASSERT(args.length() == 3);
 
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
+  CONVERT_ARG_CHECKED(String, s, 0);
   CONVERT_BOOLEAN_ARG_CHECKED(trimLeft, 1);
   CONVERT_BOOLEAN_ARG_CHECKED(trimRight, 2);
 
-  string = FlattenGetString(string);
-  int length = string->length();
+  s->TryFlatten();
+  int length = s->length();
 
   int left = 0;
   if (trimLeft) {
-    while (left < length && IsTrimWhiteSpace(string->Get(left))) {
+    while (left < length && IsTrimWhiteSpace(s->Get(left))) {
       left++;
     }
   }
 
   int right = length;
   if (trimRight) {
-    while (right > left && IsTrimWhiteSpace(string->Get(right - 1))) {
+    while (right > left && IsTrimWhiteSpace(s->Get(right - 1))) {
       right--;
     }
   }
-
-  return *isolate->factory()->NewSubString(string, left, right);
+  return s->SubString(left, right);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringSplit) {
   HandleScope handle_scope(isolate);
   ASSERT(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, pattern, 1);
   CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[2]);
 
@@ skipping 382 matching lines @@
   SealHandleScope shs(isolate);
   ASSERT(args.length() == 2);
 
   CONVERT_NUMBER_CHECKED(int32_t, x, Int32, args[0]);
   CONVERT_NUMBER_CHECKED(int32_t, y, Int32, args[1]);
   return isolate->heap()->NumberFromInt32(x * y);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringAdd) {
-  HandleScope scope(isolate);
+  SealHandleScope shs(isolate);
   ASSERT(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, str1, 0);
-  CONVERT_ARG_HANDLE_CHECKED(String, str2, 1);
+  CONVERT_ARG_CHECKED(String, str1, 0);
+  CONVERT_ARG_CHECKED(String, str2, 1);
   isolate->counters()->string_add_runtime()->Increment();
-  return *isolate->factory()->NewConsString(str1, str2);
+  return isolate->heap()->AllocateConsString(str1, str2);
 }
 
 
 template <typename sinkchar>
 static inline void StringBuilderConcatHelper(String* special,
                                              sinkchar* sink,
                                              FixedArray* fixed_array,
                                              int array_length) {
   int position = 0;
   for (int i = 0; i < array_length; i++) {
@@ skipping 7893 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal