[heap] Force all RO_SPACE strings to be internalized

Since RO_SPACE strings cannot be written to after creation, they cannot
be internalized later. This adds checks to normal string construction
methods that they are not created with TENURED_READ_ONLY.

Also changes the Symbol construction in setup-heap-internal.cc to use
internalized strings, which increases the number of internalized
RO_SPACE strings from 490 to 514 (915 including OLD_SPACE).

Bug: chromium:911416
Change-Id: I222ff883e98f3a2f4ce70d369f22273f5c9edb0b
Reviewed-on: https://chromium-review.googlesource.com/c/1365279Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58074}

src/heap/factory.cc

@@ -619,6 +619,7 @@ Handle<String> Factory::InternalizeStringWithKey(StringTableKey* key) {
 
 MaybeHandle<String> Factory::NewStringFromOneByte(Vector<const uint8_t> string,
                                                   PretenureFlag pretenure) {
+  DCHECK_NE(pretenure, TENURED_READ_ONLY);
   int length = string.length();
   if (length == 0) return empty_string();
   if (length == 1) return LookupSingleCharacterStringFromCode(string[0]);
@@ -636,6 +637,7 @@ MaybeHandle<String> Factory::NewStringFromOneByte(Vector<const uint8_t> string,
 
 MaybeHandle<String> Factory::NewStringFromUtf8(Vector<const char> string,
                                                PretenureFlag pretenure) {
+  DCHECK_NE(pretenure, TENURED_READ_ONLY);
   // Check for ASCII first since this is the common case.
   const char* ascii_data = string.start();
   int length = string.length();
@@ -731,6 +733,7 @@ MaybeHandle<String> Factory::NewStringFromUtf8SubString(
 MaybeHandle<String> Factory::NewStringFromTwoByte(const uc16* string,
                                                   int length,
                                                   PretenureFlag pretenure) {
+  DCHECK_NE(pretenure, TENURED_READ_ONLY);
   if (length == 0) return empty_string();
   if (String::IsOneByte(string, length)) {
     if (length == 1) return LookupSingleCharacterStringFromCode(string[0]);

src/heap/setup-heap-internal.cc

@@ -723,21 +723,19 @@ void Heap::CreateInitialObjects() {
 
   {
     HandleScope scope(isolate());
-#define SYMBOL_INIT(_, name, description)                                 \
-  Handle<Symbol> name = factory->NewSymbol(TENURED_READ_ONLY);            \
-  Handle<String> name##d =                                                \
-      factory->NewStringFromStaticChars(#description, TENURED_READ_ONLY); \
-  name->set_name(*name##d);                                               \
+#define SYMBOL_INIT(_, name, description)                                \
+  Handle<Symbol> name = factory->NewSymbol(TENURED_READ_ONLY);           \
+  Handle<String> name##d = factory->InternalizeUtf8String(#description); \
+  name->set_name(*name##d);                                              \
   roots_table()[RootIndex::k##name] = *name;
     PUBLIC_SYMBOL_LIST_GENERATOR(SYMBOL_INIT, /* not used */)
 #undef SYMBOL_INIT
 
-#define SYMBOL_INIT(_, name, description)                                 \
-  Handle<Symbol> name = factory->NewSymbol(TENURED_READ_ONLY);            \
-  Handle<String> name##d =                                                \
-      factory->NewStringFromStaticChars(#description, TENURED_READ_ONLY); \
-  name->set_is_well_known_symbol(true);                                   \
-  name->set_name(*name##d);                                               \
+#define SYMBOL_INIT(_, name, description)                                \
+  Handle<Symbol> name = factory->NewSymbol(TENURED_READ_ONLY);           \
+  Handle<String> name##d = factory->InternalizeUtf8String(#description); \
+  name->set_is_well_known_symbol(true);                                  \
+  name->set_name(*name##d);                                              \
   roots_table()[RootIndex::k##name] = *name;
     WELL_KNOWN_SYMBOL_LIST_GENERATOR(SYMBOL_INIT, /* not used */)
 #undef SYMBOL_INIT