[Parser] Introduce AstStringConstants to share constants across AstValueFactory

Creates an AstStringConstants container which pre-initializes the
string constants used by AstValueFactory. This ensures that all
AstValueFactories will produce the same AstValue objects for constants,
and so they can be used by the BytecodeGenerator without having to pass
the AstValueFactory to it, enabling construction off-thread.

BUG=v8:5203

Review-Url: https://codereview.chromium.org/2630343002
Cr-Commit-Position: refs/heads/master@{#42381}

src/ast/ast-value-factory.cc

@@ -221,7 +221,6 @@ void AstValue::Internalize(Isolate* isolate) {
   }
 }
 
-
 AstRawString* AstValueFactory::GetOneByteStringInternal(
     Vector<const uint8_t> literal) {
   if (literal.length() == 1 && IsInRange(literal[0], 'a', 'z')) {

src/ast/ast-value-factory.h

@@ -111,8 +111,9 @@ class AstRawString final : public AstString {
   }
 
  private:
-  friend class AstValueFactory;
   friend class AstRawStringInternalizationKey;
+  friend class AstStringConstants;
+  friend class AstValueFactory;
 
   AstRawString(bool is_one_byte, const Vector<const byte>& literal_bytes,
                uint32_t hash)
@@ -292,7 +293,6 @@ class AstValue : public ZoneObject {
   };
 };
 
-
 // For generating constants.
 #define STRING_CONSTANTS(F)                     \
   F(anonymous_function, "(anonymous function)") \
@@ -332,6 +332,45 @@ class AstValue : public ZoneObject {
   F(use_strict, "use strict")                   \
   F(value, "value")
 
+class AstStringConstants final {
+ public:
+  AstStringConstants(Isolate* isolate, uint32_t hash_seed)
+      : zone_(isolate->allocator(), ZONE_NAME), hash_seed_(hash_seed) {
+    DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
+#define F(name, str)                                                      \
+  {                                                                       \
+    const char* data = str;                                               \
+    Vector<const uint8_t> literal(reinterpret_cast<const uint8_t*>(data), \
+                                  static_cast<int>(strlen(data)));        \
+    uint32_t hash = StringHasher::HashSequentialString<uint8_t>(          \
+        literal.start(), literal.length(), hash_seed_);                   \
+    name##_string_ = new (&zone_) AstRawString(true, literal, hash);      \
+    /* The Handle returned by the factory is located on the roots */      \
+    /* array, not on the temporary HandleScope, so this is safe.  */      \
+    name##_string_->set_string(isolate->factory()->name##_string());      \
+  }
+    STRING_CONSTANTS(F)
+#undef F
+  }
+
+#define F(name, str) \
+  AstRawString* name##_string() { return name##_string_; }
+  STRING_CONSTANTS(F)
+#undef F
+
+  uint32_t hash_seed() const { return hash_seed_; }
+
+ private:
+  Zone zone_;
+  uint32_t hash_seed_;
+
+#define F(name, str) AstRawString* name##_string_;
+  STRING_CONSTANTS(F)
+#undef F
+
+  DISALLOW_COPY_AND_ASSIGN(AstStringConstants);
+};
+
 #define OTHER_CONSTANTS(F) \
   F(true_value)            \
   F(false_value)           \
@@ -341,23 +380,24 @@ class AstValue : public ZoneObject {
 
 class AstValueFactory {
  public:
-  AstValueFactory(Zone* zone, uint32_t hash_seed)
+  AstValueFactory(Zone* zone, AstStringConstants* string_constants,
+                  uint32_t hash_seed)
       : string_table_(AstRawStringCompare),
         values_(nullptr),
         strings_(nullptr),
         strings_end_(&strings_),
+        string_constants_(string_constants),
         zone_(zone),
         hash_seed_(hash_seed) {
-#define F(name, str) name##_string_ = NULL;
-    STRING_CONSTANTS(F)
-#undef F
-#define F(name) name##_ = NULL;
+#define F(name) name##_ = nullptr;
     OTHER_CONSTANTS(F)
 #undef F
+    DCHECK_EQ(hash_seed, string_constants->hash_seed());
     std::fill(smis_, smis_ + arraysize(smis_), nullptr);
     std::fill(one_character_strings_,
               one_character_strings_ + arraysize(one_character_strings_),
               nullptr);
+    InitializeStringConstants();
   }
 
   Zone* zone() const { return zone_; }
@@ -378,15 +418,9 @@ class AstValueFactory {
 
   void Internalize(Isolate* isolate);
 
-#define F(name, str)                                                    \
-  const AstRawString* name##_string() {                                 \
-    if (name##_string_ == NULL) {                                       \
-      const char* data = str;                                           \
-      name##_string_ = GetOneByteString(                                \
-          Vector<const uint8_t>(reinterpret_cast<const uint8_t*>(data), \
-                                static_cast<int>(strlen(data))));       \
-    }                                                                   \
-    return name##_string_;                                              \
+#define F(name, str)                           \
+  const AstRawString* name##_string() {        \
+    return string_constants_->name##_string(); \
   }
   STRING_CONSTANTS(F)
 #undef F
@@ -427,6 +461,17 @@ class AstValueFactory {
   AstRawString* GetString(uint32_t hash, bool is_one_byte,
                           Vector<const byte> literal_bytes);
 
+  void InitializeStringConstants() {
+#define F(name, str)                                                    \
+  AstRawString* raw_string_##name = string_constants_->name##_string(); \
+  base::HashMap::Entry* entry_##name = string_table_.LookupOrInsert(    \
+      raw_string_##name, raw_string_##name->hash());                    \
+  DCHECK(entry_##name->value == nullptr);                               \
+  entry_##name->value = reinterpret_cast<void*>(1);
+    STRING_CONSTANTS(F)
+#undef F
+  }
+
   static bool AstRawStringCompare(void* a, void* b);
 
   // All strings are copied here, one after another (no NULLs inbetween).
@@ -440,6 +485,9 @@ class AstValueFactory {
   AstString* strings_;
   AstString** strings_end_;
 
+  // Holds constant string values which are shared across the isolate.
+  AstStringConstants* string_constants_;
+
   // Caches for faster access: small numbers, one character lowercase strings
   // (for minified code).
   AstValue* smis_[kMaxCachedSmi + 1];
@@ -449,10 +497,6 @@ class AstValueFactory {
 
   uint32_t hash_seed_;
 
-#define F(name, str) const AstRawString* name##_string_;
-  STRING_CONSTANTS(F)
-#undef F
-
 #define F(name) AstValue* name##_;
   OTHER_CONSTANTS(F)
 #undef F

src/heap-symbols.h

@@ -6,6 +6,7 @@
 #define V8_HEAP_SYMBOLS_H_
 
 #define INTERNALIZED_STRING_LIST(V)                                \
+  V(anonymous_function_string, "(anonymous function)")             \
   V(anonymous_string, "anonymous")                                 \
   V(apply_string, "apply")                                         \
   V(arguments_string, "arguments")                                 \
@@ -14,6 +15,8 @@
   V(Array_string, "Array")                                         \
   V(ArrayIterator_string, "Array Iterator")                        \
   V(assign_string, "assign")                                       \
+  V(async_string, "async")                                         \
+  V(await_string, "await")                                         \
   V(array_to_string, "[object Array]")                             \
   V(boolean_to_string, "[object Boolean]")                         \
   V(date_to_string, "[object Date]")                               \
@@ -57,7 +60,12 @@
   V(did_handle_string, "didHandle")                                \
   V(display_name_string, "displayName")                            \
   V(done_string, "done")                                           \
+  V(dot_catch_string, ".catch")                                    \
+  V(dot_for_string, ".for")                                        \
+  V(dot_generator_object_string, ".generator_object")              \
+  V(dot_iterator_string, ".iterator")                              \
   V(dot_result_string, ".result")                                  \
+  V(dot_switch_tag_string, ".switch_tag")                          \
   V(dot_string, ".")                                               \
   V(exec_string, "exec")                                           \
   V(entries_string, "entries")                                     \
@@ -78,6 +86,7 @@
   V(getOwnPropertyDescriptors_string, "getOwnPropertyDescriptors") \
   V(getPrototypeOf_string, "getPrototypeOf")                       \
   V(get_string, "get")                                             \
+  V(get_space_string, "get ")                                      \
   V(global_string, "global")                                       \
   V(has_string, "has")                                             \
   V(hour_string, "hour")                                           \
@@ -100,6 +109,7 @@
   V(keys_string, "keys")                                           \
   V(lastIndex_string, "lastIndex")                                 \
   V(length_string, "length")                                       \
+  V(let_string, "let")                                             \
   V(line_string, "line")                                           \
   V(literal_string, "literal")                                     \
   V(Map_string, "Map")                                             \
@@ -110,7 +120,9 @@
   V(month_string, "month")                                         \
   V(multiline_string, "multiline")                                 \
   V(name_string, "name")                                           \
+  V(native_string, "native")                                       \
   V(nan_string, "NaN")                                             \
+  V(new_target_string, ".new.target")                              \
   V(next_string, "next")                                           \
   V(not_equal, "not-equal")                                        \
   V(null_string, "null")                                           \
@@ -135,9 +147,11 @@
   V(RegExp_string, "RegExp")                                       \
   V(reject_string, "reject")                                       \
   V(resolve_string, "resolve")                                     \
+  V(return_string, "return")                                       \
   V(script_string, "script")                                       \
   V(second_string, "second")                                       \
   V(setPrototypeOf_string, "setPrototypeOf")                       \
+  V(set_space_string, "set ")                                      \
   V(set_string, "set")                                             \
   V(Set_string, "Set")                                             \
   V(source_mapping_url_string, "source_mapping_url")               \
@@ -146,6 +160,7 @@
   V(source_url_string, "source_url")                               \
   V(stack_string, "stack")                                         \
   V(stackTraceLimit_string, "stackTraceLimit")                     \
+  V(star_default_star_string, "*default*")                         \
   V(sticky_string, "sticky")                                       \
   V(strict_compare_ic_string, "===")                               \
   V(string_string, "string")                                       \
@@ -155,6 +170,7 @@
   V(symbol_species_string, "[Symbol.species]")                     \
   V(SyntaxError_string, "SyntaxError")                             \
   V(then_string, "then")                                           \
+  V(this_function_string, ".this_function")                        \
   V(this_string, "this")                                           \
   V(throw_string, "throw")                                         \
   V(timed_out, "timed-out")                                        \
@@ -176,6 +192,8 @@
   V(undefined_string, "undefined")                                 \
   V(undefined_to_string, "[object Undefined]")                     \
   V(unicode_string, "unicode")                                     \
+  V(use_asm_string, "use asm")                                     \
+  V(use_strict_string, "use strict")                               \
   V(URIError_string, "URIError")                                   \
   V(valueOf_string, "valueOf")                                     \
   V(values_string, "values")                                       \

src/interpreter/bytecode-generator.cc

@@ -587,13 +587,10 @@ BytecodeGenerator::BytecodeGenerator(CompilationInfo* info)
       loop_depth_(0),
       home_object_symbol_(info->isolate()->factory()->home_object_symbol()),
       iterator_symbol_(info->isolate()->factory()->iterator_symbol()),
-      empty_fixed_array_(info->isolate()->factory()->empty_fixed_array()) {
-  AstValueFactory* ast_value_factory = info->parse_info()->ast_value_factory();
-  const AstRawString* prototype_string = ast_value_factory->prototype_string();
-  ast_value_factory->Internalize(info->isolate());
-  prototype_string_ = prototype_string->string();
-  undefined_string_ = ast_value_factory->undefined_string();
-}
+      prototype_string_(info->isolate()->factory()->prototype_string()),
+      empty_fixed_array_(info->isolate()->factory()->empty_fixed_array()),
+      undefined_string_(
+          info->isolate()->ast_string_constants()->undefined_string()) {}
 
 Handle<BytecodeArray> BytecodeGenerator::FinalizeBytecode(Isolate* isolate) {
   AllocateDeferredConstants(isolate);

src/isolate.cc

@@ -9,6 +9,7 @@
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
+#include "src/ast/ast-value-factory.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/hashmap.h"
 #include "src/base/platform/platform.h"
@@ -2375,6 +2376,9 @@ void Isolate::Deinit() {
   delete interpreter_;
   interpreter_ = NULL;
 
+  delete ast_string_constants_;
+  ast_string_constants_ = nullptr;
+
   delete cpu_profiler_;
   cpu_profiler_ = NULL;
 
@@ -2698,6 +2702,11 @@ bool Isolate::Init(Deserializer* des) {
 
   time_millis_at_init_ = heap_.MonotonicallyIncreasingTimeInMs();
 
+  {
+    HandleScope scope(this);
+    ast_string_constants_ = new AstStringConstants(this, heap()->HashSeed());
+  }
+
   if (!create_heap_objects) {
     // Now that the heap is consistent, it's OK to generate the code for the
     // deopt entry table that might have been referred to by optimized code in

src/isolate.h

@@ -35,6 +35,7 @@ namespace internal {
 
 class AccessCompilerData;
 class AddressToIndexHashMap;
+class AstStringConstants;
 class BasicBlockProfiler;
 class Bootstrapper;
 class CancelableTaskManager;
@@ -1157,6 +1158,10 @@ class Isolate {
     return cancelable_task_manager_;
   }
 
+  AstStringConstants* ast_string_constants() const {
+    return ast_string_constants_;
+  }
+
   interpreter::Interpreter* interpreter() const { return interpreter_; }
 
   AccountingAllocator* allocator() { return allocator_; }
@@ -1399,6 +1404,8 @@ class Isolate {
   std::unique_ptr<CodeEventDispatcher> code_event_dispatcher_;
   FunctionEntryHook function_entry_hook_;
 
+  AstStringConstants* ast_string_constants_;
+
   interpreter::Interpreter* interpreter_;
 
   CompilerDispatcher* compiler_dispatcher_;

src/parsing/parser.cc

@@ -559,7 +559,8 @@ Parser::Parser(ParseInfo* info)
   }
   if (info->ast_value_factory() == NULL) {
     // info takes ownership of AstValueFactory.
-    info->set_ast_value_factory(new AstValueFactory(zone(), info->hash_seed()));
+    info->set_ast_value_factory(new AstValueFactory(
+        zone(), info->isolate()->ast_string_constants(), info->hash_seed()));
     info->set_ast_value_factory_owned();
     ast_value_factory_ = info->ast_value_factory();
     ast_node_factory_.set_ast_value_factory(ast_value_factory_);

test/cctest/asmjs/test-asm-typer.cc

@@ -47,7 +47,8 @@ class AsmTyperHarnessBuilder {
         handles_(),
         zone_(handles_.main_zone()),
         isolate_(CcTest::i_isolate()),
-        ast_value_factory_(zone_, isolate_->heap()->HashSeed()),
+        ast_value_factory_(zone_, isolate_->ast_string_constants(),
+                           isolate_->heap()->HashSeed()),
         factory_(isolate_->factory()),
         source_code_(
             factory_->NewStringFromUtf8(CStrVector(source)).ToHandleChecked()),

test/cctest/test-ast.cc

@@ -30,6 +30,7 @@
 #include "src/v8.h"
 
 #include "src/ast/ast.h"
+#include "src/isolate.h"
 #include "src/objects-inl.h"
 #include "src/zone/accounting-allocator.h"
 #include "test/cctest/cctest.h"
@@ -37,12 +38,16 @@
 using namespace v8::internal;
 
 TEST(List) {
+  v8::V8::Initialize();
+  Isolate* isolate = CcTest::i_isolate();
+
   List<AstNode*>* list = new List<AstNode*>(0);
   CHECK_EQ(0, list->length());
 
   v8::internal::AccountingAllocator allocator;
   Zone zone(&allocator, ZONE_NAME);
-  AstValueFactory value_factory(&zone, 0);
+  AstValueFactory value_factory(&zone, isolate->ast_string_constants(),
+                                isolate->heap()->HashSeed());
   AstNodeFactory factory(&value_factory);
   AstNode* node = factory.NewEmptyStatement(kNoSourcePosition);
   list->Add(node);

test/cctest/test-parsing.cc

@@ -175,7 +175,8 @@ TEST(ScanHTMLEndComments) {
     scanner.Initialize(stream.get());
     i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
     i::AstValueFactory ast_value_factory(
-        &zone, CcTest::i_isolate()->heap()->HashSeed());
+        &zone, CcTest::i_isolate()->ast_string_constants(),
+        CcTest::i_isolate()->heap()->HashSeed());
     i::PendingCompilationErrorHandler pending_error_handler;
     i::PreParser preparser(
         &zone, &scanner, stack_limit, &ast_value_factory,
@@ -193,7 +194,8 @@ TEST(ScanHTMLEndComments) {
     scanner.Initialize(stream.get());
     i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
     i::AstValueFactory ast_value_factory(
-        &zone, CcTest::i_isolate()->heap()->HashSeed());
+        &zone, CcTest::i_isolate()->ast_string_constants(),
+        CcTest::i_isolate()->heap()->HashSeed());
     i::PendingCompilationErrorHandler pending_error_handler;
     i::PreParser preparser(
         &zone, &scanner, stack_limit, &ast_value_factory,
@@ -364,7 +366,8 @@ TEST(StandAlonePreParser) {
 
     i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
     i::AstValueFactory ast_value_factory(
-        &zone, CcTest::i_isolate()->heap()->HashSeed());
+        &zone, CcTest::i_isolate()->ast_string_constants(),
+        CcTest::i_isolate()->heap()->HashSeed());
     i::PendingCompilationErrorHandler pending_error_handler;
     i::PreParser preparser(
         &zone, &scanner, stack_limit, &ast_value_factory,
@@ -400,7 +403,8 @@ TEST(StandAlonePreParserNoNatives) {
     // Preparser defaults to disallowing natives syntax.
     i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
     i::AstValueFactory ast_value_factory(
-        &zone, CcTest::i_isolate()->heap()->HashSeed());
+        &zone, CcTest::i_isolate()->ast_string_constants(),
+        CcTest::i_isolate()->heap()->HashSeed());
     i::PendingCompilationErrorHandler pending_error_handler;
     i::PreParser preparser(&zone, &scanner, stack_limit, &ast_value_factory,
                            &pending_error_handler,
@@ -466,8 +470,9 @@ TEST(RegressChromium62639) {
   i::Scanner scanner(CcTest::i_isolate()->unicode_cache());
   scanner.Initialize(stream.get());
   i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
-  i::AstValueFactory ast_value_factory(&zone,
-                                       CcTest::i_isolate()->heap()->HashSeed());
+  i::AstValueFactory ast_value_factory(
+      &zone, CcTest::i_isolate()->ast_string_constants(),
+      CcTest::i_isolate()->heap()->HashSeed());
   i::PendingCompilationErrorHandler pending_error_handler;
   i::PreParser preparser(&zone, &scanner,
                          CcTest::i_isolate()->stack_guard()->real_climit(),
@@ -541,8 +546,9 @@ TEST(PreParseOverflow) {
   scanner.Initialize(stream.get());
 
   i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
-  i::AstValueFactory ast_value_factory(&zone,
-                                       CcTest::i_isolate()->heap()->HashSeed());
+  i::AstValueFactory ast_value_factory(
+      &zone, CcTest::i_isolate()->ast_string_constants(),
+      CcTest::i_isolate()->heap()->HashSeed());
   i::PendingCompilationErrorHandler pending_error_handler;
   i::PreParser preparser(&zone, &scanner, stack_limit, &ast_value_factory,
                          &pending_error_handler,
@@ -642,8 +648,9 @@ void TestScanRegExp(const char* re_source, const char* expected) {
   CHECK(scanner.ScanRegExpPattern());
   scanner.Next();  // Current token is now the regexp literal.
   i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
-  i::AstValueFactory ast_value_factory(&zone,
-                                       CcTest::i_isolate()->heap()->HashSeed());
+  i::AstValueFactory ast_value_factory(
+      &zone, CcTest::i_isolate()->ast_string_constants(),
+      CcTest::i_isolate()->heap()->HashSeed());
   const i::AstRawString* current_symbol =
       scanner.CurrentSymbol(&ast_value_factory);
   ast_value_factory.Internalize(CcTest::i_isolate());
@@ -1330,7 +1337,8 @@ void TestParserSyncWithFlags(i::Handle<i::String> source,
         i::ScannerStream::For(source));
     i::Zone zone(CcTest::i_isolate()->allocator(), ZONE_NAME);
     i::AstValueFactory ast_value_factory(
-        &zone, CcTest::i_isolate()->heap()->HashSeed());
+        &zone, CcTest::i_isolate()->ast_string_constants(),
+        CcTest::i_isolate()->heap()->HashSeed());
     i::PreParser preparser(&zone, &scanner, stack_limit, &ast_value_factory,
                            &pending_error_handler,
                            isolate->counters()->runtime_call_stats());
@@ -3164,7 +3172,8 @@ TEST(SerializationOfMaybeAssignmentFlag) {
   i::Handle<i::Object> o = v8::Utils::OpenHandle(*v);
   i::Handle<i::JSFunction> f = i::Handle<i::JSFunction>::cast(o);
   i::Context* context = f->context();
-  i::AstValueFactory avf(&zone, isolate->heap()->HashSeed());
+  i::AstValueFactory avf(&zone, isolate->ast_string_constants(),
+                         isolate->heap()->HashSeed());
   const i::AstRawString* name = avf.GetOneByteString("result");
   avf.Internalize(isolate);
   i::Handle<i::String> str = name->string();
@@ -3213,7 +3222,8 @@ TEST(IfArgumentsArrayAccessedThenParametersMaybeAssigned) {
   i::Handle<i::Object> o = v8::Utils::OpenHandle(*v);
   i::Handle<i::JSFunction> f = i::Handle<i::JSFunction>::cast(o);
   i::Context* context = f->context();
-  i::AstValueFactory avf(&zone, isolate->heap()->HashSeed());
+  i::AstValueFactory avf(&zone, isolate->ast_string_constants(),
+                         isolate->heap()->HashSeed());
   const i::AstRawString* name_x = avf.GetOneByteString("x");
   avf.Internalize(isolate);
 
@@ -3509,7 +3519,8 @@ namespace {
 
 i::Scope* DeserializeFunctionScope(i::Isolate* isolate, i::Zone* zone,
                                    i::Handle<i::JSObject> m, const char* name) {
-  i::AstValueFactory avf(zone, isolate->heap()->HashSeed());
+  i::AstValueFactory avf(zone, isolate->ast_string_constants(),
+                         isolate->heap()->HashSeed());
   i::Handle<i::JSFunction> f = i::Handle<i::JSFunction>::cast(
       i::JSReceiver::GetProperty(isolate, m, name).ToHandleChecked());
   i::DeclarationScope* script_scope =