[V8] Make String::CanMakeExternal ignore the length of new strings

test/cctest/test-api.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 538 matching lines @@
 
 TEST(MakingExternalStringConditions) {
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());
 
   // Free some space in the new space so that we can check freshness.
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);
 
   uint16_t* two_byte_string = AsciiToTwoByteString("s1");
-  Local<String> small_string =
+  Local<String> local_string =
       String::NewFromTwoByte(env->GetIsolate(), two_byte_string,
                              v8::NewStringType::kNormal)
           .ToLocalChecked();
   i::DeleteArray(two_byte_string);
 
-  // We should refuse to externalize small strings.
-  CHECK(!small_string->CanMakeExternal());
+  // We should refuse to externalize new space strings.
+  CHECK(!local_string->CanMakeExternal());
   // Trigger GCs so that the newly allocated string moves to old gen.
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);  // in survivor space now
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);  // in old gen now
   // Old space strings should be accepted.
-  CHECK(small_string->CanMakeExternal());
-
-  two_byte_string = AsciiToTwoByteString("small string 2");
-  small_string = String::NewFromTwoByte(env->GetIsolate(), two_byte_string,
-                                        v8::NewStringType::kNormal)
-                     .ToLocalChecked();
-  i::DeleteArray(two_byte_string);
-
-  const int buf_size = 10 * 1024;
-  char* buf = i::NewArray<char>(buf_size);
-  memset(buf, 'a', buf_size);
-  buf[buf_size - 1] = '\0';
-
-  two_byte_string = AsciiToTwoByteString(buf);
-  Local<String> large_string =
-      String::NewFromTwoByte(env->GetIsolate(), two_byte_string,
-                             v8::NewStringType::kNormal)
-          .ToLocalChecked();
-  i::DeleteArray(buf);
-  i::DeleteArray(two_byte_string);
-  // Large strings should be immediately accepted.
-  CHECK(large_string->CanMakeExternal());
+  CHECK(local_string->CanMakeExternal());
 }
 
 
 TEST(MakingExternalOneByteStringConditions) {
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());
 
   // Free some space in the new space so that we can check freshness.
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);
 
-  Local<String> small_string = v8_str("s1");
-  // We should refuse to externalize small strings.
-  CHECK(!small_string->CanMakeExternal());
+  Local<String> local_string = v8_str("s1");
+  // We should refuse to externalize new space strings.
+  CHECK(!local_string->CanMakeExternal());
   // Trigger GCs so that the newly allocated string moves to old gen.
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);  // in survivor space now
   CcTest::heap()->CollectGarbage(i::NEW_SPACE);  // in old gen now
   // Old space strings should be accepted.
-  CHECK(small_string->CanMakeExternal());
-
-  const int buf_size = 10 * 1024;
-  char* buf = i::NewArray<char>(buf_size);
-  memset(buf, 'a', buf_size);
-  buf[buf_size - 1] = '\0';
-  Local<String> large_string = v8_str(buf);
-  i::DeleteArray(buf);
-  // Large strings should be immediately accepted.
-  CHECK(large_string->CanMakeExternal());
+  CHECK(local_string->CanMakeExternal());
 }
 
 
 TEST(MakingExternalUnalignedOneByteString) {
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());
 
   CompileRun("function cons(a, b) { return a + b; }"
              "function slice(a) { return a.substring(1); }");
   // Create a cons string that will land in old pointer space.
@@ skipping 24739 matching lines @@
 }
 
 TEST(PrivateForApiIsNumber) {
   LocalContext context;
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);
 
   // Shouldn't crash.
   v8::Private::ForApi(isolate, v8_str("42"));
 }