[interpreter] Fix nosnap build for interpreter table generation.

Moves the creation of the interpreter table early on during initialization
to ensure that even on nosnap builds it still gets allocated in the
first page.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1278413002

Cr-Commit-Position: refs/heads/master@{#30096}

src/heap/heap.cc

@@ -26,6 +26,7 @@
 #include "src/heap/objects-visiting.h"
 #include "src/heap/store-buffer.h"
 #include "src/heap-profiler.h"
+#include "src/interpreter/interpreter.h"
 #include "src/runtime-profiler.h"
 #include "src/scopeinfo.h"
 #include "src/snapshot/natives.h"
@@ -3363,7 +3364,9 @@ void Heap::CreateInitialObjects() {
   set_weak_stack_trace_list(Smi::FromInt(0));
 
   // Will be filled in by Interpreter::Initialize().
-  set_interpreter_table(empty_fixed_array());
+  set_interpreter_table(
+      *interpreter::Interpreter::CreateUninitializedInterpreterTable(
+          isolate()));
 
   set_allocation_sites_scratchpad(
       *factory->NewFixedArray(kAllocationSiteScratchpadSize, TENURED));
@@ -3415,7 +3418,6 @@ bool Heap::RootCanBeWrittenAfterInitialization(Heap::RootListIndex root_index) {
     case kWeakObjectToCodeTableRootIndex:
     case kRetainedMapsRootIndex:
     case kWeakStackTraceListRootIndex:
-    case kInterpreterTableRootIndex:
 // Smi values
 #define SMI_ENTRY(type, name, Name) case k##Name##RootIndex:
       SMI_ROOT_LIST(SMI_ENTRY)

src/heap/heap.h

@@ -1024,10 +1024,6 @@ class Heap {
     roots_[kMaterializedObjectsRootIndex] = objects;
   }
 
-  void public_set_interpreter_table(FixedArray* table) {
-    roots_[kInterpreterTableRootIndex] = table;
-  }
-
   // Generated code can embed this address to get access to the roots.
   Object** roots_array_start() { return roots_; }
 

src/interpreter/interpreter.cc

@@ -18,21 +18,32 @@ using compiler::Node;
 #define __ assembler->
 
 
-Interpreter::Interpreter(Isolate* isolate) : isolate_(isolate) {}
+Interpreter::Interpreter(Isolate* isolate)
+    : isolate_(isolate) {}
 
 
-void Interpreter::Initialize(bool create_heap_objects) {
-  DCHECK(FLAG_ignition);
-  if (create_heap_objects) {
-    Zone zone;
-    HandleScope scope(isolate_);
-    Handle<FixedArray> handler_table = isolate_->factory()->NewFixedArray(
+// static
+Handle<FixedArray> Interpreter::CreateUninitializedInterpreterTable(
+    Isolate* isolate) {
+  Handle<FixedArray> handler_table = isolate->factory()->NewFixedArray(
       static_cast<int>(Bytecode::kLast) + 1, TENURED);
   // We rely on the interpreter handler table being immovable, so check that
   // it was allocated on the first page (which is always immovable).
-    DCHECK(isolate_->heap()->old_space()->FirstPage()->Contains(
+  DCHECK(isolate->heap()->old_space()->FirstPage()->Contains(
       handler_table->address()));
-    isolate_->heap()->public_set_interpreter_table(*handler_table);
+  for (int i = 0; i < static_cast<int>(Bytecode::kLast); i++) {
+    handler_table->set(i, isolate->builtins()->builtin(Builtins::kIllegal));
+  }
+  return handler_table;
+}
+
+
+void Interpreter::Initialize() {
+  DCHECK(FLAG_ignition);
+  Handle<FixedArray> handler_table = isolate_->factory()->interpreter_table();
+  if (!IsInterpreterTableInitialized(handler_table)) {
+    Zone zone;
+    HandleScope scope(isolate_);
 
 #define GENERATE_CODE(Name, ...)                                      \
     {                                                                 \
@@ -48,6 +59,14 @@ void Interpreter::Initialize(bool create_heap_objects) {
 }
 
 
+bool Interpreter::IsInterpreterTableInitialized(
+    Handle<FixedArray> handler_table) {
+  DCHECK(handler_table->length() == static_cast<int>(Bytecode::kLast) + 1);
+  return handler_table->get(0) ==
+         isolate_->builtins()->builtin(Builtins::kIllegal);
+}
+
+
 // LdaZero
 //
 // Load literal '0' into the accumulator.

src/interpreter/interpreter.h

@@ -28,7 +28,13 @@ class Interpreter {
   explicit Interpreter(Isolate* isolate);
   virtual ~Interpreter() {}
 
-  void Initialize(bool create_heap_objects);
+  // Creates an uninitialized interpreter handler table, where each handler
+  // points to the Illegal builtin.
+  static Handle<FixedArray> CreateUninitializedInterpreterTable(
+      Isolate* isolate);
+
+  // Initializes the interpreter.
+  void Initialize();
 
  private:
 // Bytecode handler generator functions.
@@ -37,6 +43,8 @@ class Interpreter {
   BYTECODE_LIST(DECLARE_BYTECODE_HANDLER_GENERATOR)
 #undef DECLARE_BYTECODE_HANDLER_GENERATOR
 
+  bool IsInterpreterTableInitialized(Handle<FixedArray> handler_table);
+
   Isolate* isolate_;
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);

src/isolate.cc

@@ -2167,7 +2167,7 @@ bool Isolate::Init(Deserializer* des) {
   builtins_.SetUp(this, create_heap_objects);
 
   if (FLAG_ignition) {
-    interpreter_->Initialize(create_heap_objects);
+    interpreter_->Initialize();
   }
 
   if (FLAG_log_internal_timer_events) {

test/cctest/interpreter/test-interpreter.cc

@@ -35,13 +35,8 @@ class InterpreterTester {
   InterpreterTester(Isolate* isolate, Handle<BytecodeArray> bytecode)
       : isolate_(isolate), function_(GetBytecodeFunction(isolate, bytecode)) {
     i::FLAG_ignition = true;
-    Handle<FixedArray> empty_array = isolate->factory()->empty_fixed_array();
-    Handle<FixedArray> interpreter_table =
-        isolate->factory()->interpreter_table();
-    if (interpreter_table.is_identical_to(empty_array)) {
     // Ensure handler table is generated.
-      isolate->interpreter()->Initialize(true);
-    }
+    isolate->interpreter()->Initialize();
   }
   virtual ~InterpreterTester() {}