[runtime] Introduce dedicated JSBoundFunction to represent bound functions.

src/objects.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 1850 matching lines @@
 
 void JSObject::JSObjectShortPrint(StringStream* accumulator) {
   switch (map()->instance_type()) {
     case JS_ARRAY_TYPE: {
       double length = JSArray::cast(this)->length()->IsUndefined()
           ? 0
           : JSArray::cast(this)->length()->Number();
       accumulator->Add("<JS Array[%u]>", static_cast<uint32_t>(length));
       break;
     }
+    case JS_BOUND_FUNCTION_TYPE: {
+      JSBoundFunction* bound_function = JSBoundFunction::cast(this);
+      Object* name = bound_function->name();
+      accumulator->Add("<JS BoundFunction");
+      if (name->IsString()) {
+        String* str = String::cast(name);
+        if (str->length() > 0) {
+          accumulator->Add(" ");
+          accumulator->Put(str);
+        }
+      }
+      accumulator->Add(
+          " (BoundTargetFunction %p)>",
+          reinterpret_cast<void*>(bound_function->bound_target_function()));
+      break;
+    }
     case JS_WEAK_MAP_TYPE: {
       accumulator->Add("<JS WeakMap>");
       break;
     }
     case JS_WEAK_SET_TYPE: {
       accumulator->Add("<JS WeakSet>");
       break;
     }
     case JS_REGEXP_TYPE: {
       accumulator->Add("<JS RegExp>");
@@ skipping 519 matching lines @@
     return String::cast(constructor->shared()->instance_class_name());
   }
   // If the constructor is not present, return "Object".
   return GetHeap()->Object_string();
 }
 
 
 MaybeHandle<String> JSReceiver::BuiltinStringTag(Handle<JSReceiver> object) {
   Maybe<bool> is_array = Object::IsArray(object);
   MAYBE_RETURN(is_array, MaybeHandle<String>());
+  Isolate* const isolate = object->GetIsolate();
   if (is_array.FromJust()) {
-    return object->GetIsolate()->factory()->Array_string();
+    return isolate->factory()->Array_string();
+  }
+  if (object->IsCallable()) {
+    return isolate->factory()->Function_string();
   }
   // TODO(adamk): class_name() is expensive, replace with instance type
   // checks where possible.
-  return handle(object->class_name());
+  return handle(object->class_name(), isolate);
 }
 
 
 // static
 Handle<String> JSReceiver::GetConstructorName(Handle<JSReceiver> receiver) {
   Isolate* isolate = receiver->GetIsolate();
 
   // If the object was instantiated simply with base == new.target, the
   // constructor on the map provides the most accurate name.
   // Don't provide the info for prototypes, since their constructors are
@@ skipping 8287 matching lines @@
                                          int number_of_literals,
                                          PretenureFlag pretenure) {
   Handle<FixedArray> literals = isolate->factory()->NewFixedArray(
       number_of_literals + kFirstLiteralIndex, pretenure);
   Handle<LiteralsArray> casted_literals = Handle<LiteralsArray>::cast(literals);
   casted_literals->set_feedback_vector(*vector);
   return casted_literals;
 }
 
 
-// static
-Handle<BindingsArray> BindingsArray::New(Isolate* isolate,
-                                         Handle<TypeFeedbackVector> vector,
-                                         Handle<JSReceiver> bound_function,
-                                         Handle<Object> bound_this,
-                                         int number_of_bindings) {
-  Handle<FixedArray> bindings = isolate->factory()->NewFixedArray(
-      number_of_bindings + kFirstBindingIndex);
-  Handle<BindingsArray> casted_bindings = Handle<BindingsArray>::cast(bindings);
-  casted_bindings->set_feedback_vector(*vector);
-  casted_bindings->set_bound_function(*bound_function);
-  casted_bindings->set_bound_this(*bound_this);
-  return casted_bindings;
-}
-
-
-// static
-Handle<JSArray> BindingsArray::CreateBoundArguments(
-    Handle<BindingsArray> bindings) {
-  int bound_argument_count = bindings->bindings_count();
-  Factory* factory = bindings->GetIsolate()->factory();
-  Handle<FixedArray> arguments = factory->NewFixedArray(bound_argument_count);
-  bindings->CopyTo(kFirstBindingIndex, *arguments, 0, bound_argument_count);
-  return factory->NewJSArrayWithElements(arguments);
-}
-
-
-// static
-Handle<JSArray> BindingsArray::CreateRuntimeBindings(
-    Handle<BindingsArray> bindings) {
-  Factory* factory = bindings->GetIsolate()->factory();
-  // A runtime bindings array consists of
-  // [bound function, bound this, [arg0, arg1, ...]].
-  Handle<FixedArray> runtime_bindings =
-      factory->NewFixedArray(2 + bindings->bindings_count());
-  bindings->CopyTo(kBoundFunctionIndex, *runtime_bindings, 0,
-                   2 + bindings->bindings_count());
-  return factory->NewJSArrayWithElements(runtime_bindings);
-}
-
-
 int HandlerTable::LookupRange(int pc_offset, int* stack_depth_out,
                               CatchPrediction* prediction_out) {
   int innermost_handler = -1, innermost_start = -1;
   for (int i = 0; i < length(); i += kRangeEntrySize) {
     int start_offset = Smi::cast(get(i + kRangeStartIndex))->value();
     int end_offset = Smi::cast(get(i + kRangeEndIndex))->value();
     int handler_field = Smi::cast(get(i + kRangeHandlerIndex))->value();
     int handler_offset = HandlerOffsetField::decode(handler_field);
     CatchPrediction prediction = HandlerPredictionField::decode(handler_field);
     int stack_depth = Smi::cast(get(i + kRangeDepthIndex))->value();
@@ skipping 39 matching lines @@
 #endif
 
 
 bool String::LooksValid() {
   if (!GetIsolate()->heap()->Contains(this)) return false;
   return true;
 }
 
 
 // static
-MaybeHandle<String> Name::ToFunctionName(Handle<Name> name) {
-  if (name->IsString()) return Handle<String>::cast(name);
+MaybeHandle<String> Name::ToFunctionName(Handle<Name> name,
+                                         Handle<String> prefix) {
   // ES6 section 9.2.11 SetFunctionName, step 4.
   Isolate* const isolate = name->GetIsolate();
-  Handle<Object> description(Handle<Symbol>::cast(name)->name(), isolate);
-  if (description->IsUndefined()) return isolate->factory()->empty_string();
   IncrementalStringBuilder builder(isolate);
-  builder.AppendCharacter('[');
-  builder.AppendString(Handle<String>::cast(description));
-  builder.AppendCharacter(']');
+  if (prefix->length() != 0) {
+    builder.AppendString(prefix);
+    builder.AppendCharacter(' ');
+  }
+  if (name->IsString()) {
+    builder.AppendString(Handle<String>::cast(name));
+  } else {
+    Handle<Object> description(Handle<Symbol>::cast(name)->name(), isolate);
+    if (!description->IsUndefined()) {
+      builder.AppendCharacter('[');
+      builder.AppendString(Handle<String>::cast(description));
+      builder.AppendCharacter(']');
+    }
+  }
   return builder.Finish();
 }
 
 
 namespace {
 
 bool AreDigits(const uint8_t* s, int from, int to) {
   for (int i = from; i < to; i++) {
     if (s[i] < '0' || s[i] > '9') return false;
   }
@@ skipping 1973 matching lines @@
     case JS_SET_ITERATOR_TYPE:
     case JS_MAP_ITERATOR_TYPE:
     case JS_ITERATOR_RESULT_TYPE:
     case JS_WEAK_MAP_TYPE:
     case JS_WEAK_SET_TYPE:
     case JS_PROMISE_TYPE:
     case JS_REGEXP_TYPE:
     case JS_FUNCTION_TYPE:
       return true;
 
+    case JS_BOUND_FUNCTION_TYPE:
     case JS_PROXY_TYPE:
     case JS_GLOBAL_PROXY_TYPE:
     case JS_GLOBAL_OBJECT_TYPE:
     case FIXED_ARRAY_TYPE:
     case FIXED_DOUBLE_ARRAY_TYPE:
     case ODDBALL_TYPE:
     case FOREIGN_TYPE:
     case MAP_TYPE:
     case CODE_TYPE:
     case CELL_TYPE:
@@ skipping 248 matching lines @@
     builder.AppendCString("() { [native code] }");
     return builder.Finish().ToHandleChecked();
   }
   return isolate->factory()->NewStringFromAsciiChecked(kNativeCodeSource);
 }
 
 }  // namespace
 
 
 // static
+Handle<String> JSBoundFunction::ToString(Handle<JSBoundFunction> function) {
+  Isolate* const isolate = function->GetIsolate();
+  return isolate->factory()->NewStringFromAsciiChecked(kNativeCodeSource);
+}
+
+
+// static
 Handle<String> JSFunction::ToString(Handle<JSFunction> function) {
   Isolate* const isolate = function->GetIsolate();
   Handle<SharedFunctionInfo> shared_info(function->shared(), isolate);
 
   // Check if {function} should hide its source code.
   if (!shared_info->script()->IsScript() ||
       Script::cast(shared_info->script())->hide_source()) {
     return NativeCodeFunctionSourceString(shared_info);
   }
 
@@ skipping 6351 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8