Computed property names for object literals in TurboFan.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 1009 matching lines @@
   // The object is expected on the operand stack during computation of the
   // property values and is the value of the entire expression.
   environment()->Push(literal);
 
   // Mark all computed expressions that are bound to a key that is shadowed by
   // a later occurrence of the same key. For the marked expressions, no store
   // code is emitted.
   expr->CalculateEmitStore(zone());
 
   // Create nodes to store computed values into the literal.
+  int property_index = 0;
   AccessorTable accessor_table(zone());
-  for (int i = 0; i < expr->properties()->length(); i++) {
-    ObjectLiteral::Property* property = expr->properties()->at(i);
+  for (; property_index < expr->properties()->length(); property_index++) {
+    ObjectLiteral::Property* property = expr->properties()->at(property_index);
+    if (property->is_computed_name()) break;
     if (property->IsCompileTimeValue()) continue;
 
     Literal* key = property->key()->AsLiteral();
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
         UNREACHABLE();
       case ObjectLiteral::Property::MATERIALIZED_LITERAL:
         DCHECK(!CompileTimeValue::IsCompileTimeValue(property->value()));
       // Fall through.
       case ObjectLiteral::Property::COMPUTED: {
@@ skipping 61 matching lines @@
     Node* getter = environment()->Pop();
     Node* name = environment()->Pop();
     Node* attr = jsgraph()->Constant(NONE);
     const Operator* op =
         javascript()->CallRuntime(Runtime::kDefineAccessorPropertyUnchecked, 5);
     Node* call = NewNode(op, literal, name, getter, setter, attr);
     // This should not lazy deopt on a new literal.
     PrepareFrameState(call, BailoutId::None());
   }
 
+  // Object literals have two parts. The "static" part on the left contains no
+  // computed property names, and so we can compute its map ahead of time; see
+  // Runtime_CreateObjectLiteralBoilerplate. The second "dynamic" part starts
+  // with the first computed property name and continues with all properties to
+  // its right. All the code from above initializes the static component of the
+  // object literal, and arranges for the map of the result to reflect the
+  // static order in which the keys appear. For the dynamic properties, we
+  // compile them into a series of "SetOwnProperty" runtime calls. This will
+  // preserve insertion order.
+  for (; property_index < expr->properties()->length(); property_index++) {
+    ObjectLiteral::Property* property = expr->properties()->at(property_index);
+
+    environment()->Push(literal);  // Duplicate receiver.
+    VisitForValue(property->key());
+    environment()->Push(BuildToName(environment()->Pop()));
+    // TODO(mstarzinger): For ObjectLiteral::Property::PROTOTYPE the key should

[arv (Not doing code reviews), 2015/02/13 15:15:57]

In the case of the property being `__proto__: expr` then we know the property
key is not computed. We therefore do not need to execute it. However, in that
case, property->key() is a string literal so no harm is done, just unnecessary
computations.

[Michael Starzinger, 2015/02/16 10:39:15]

The TODO is not about evaluating the "key" being observable. It is about a deopt
that could be potentially caused by evaluating the "value". In this case the
simulated operand stack in the environment needs to match up with full-codegen
exactly. If it doesn't then the deoptimizer will materialize a stack-frame on
which full-codegen will choke. AFAICT, this is the case here, so the TODO is
still accurate IMHO.

+    // not be on the operand stack while the value is being evaluated. Come up
+    // with a repro for this and fix it. Also find a nice way to do so. :)
+    VisitForValue(property->value());
+    Node* value = environment()->Pop();
+    Node* key = environment()->Pop();
+    Node* receiver = environment()->Pop();
+
+    switch (property->kind()) {
+      case ObjectLiteral::Property::CONSTANT:
+      case ObjectLiteral::Property::COMPUTED:
+      case ObjectLiteral::Property::MATERIALIZED_LITERAL: {
+        Node* attr = jsgraph()->Constant(NONE);
+        const Operator* op =
+            javascript()->CallRuntime(Runtime::kDefineDataPropertyUnchecked, 4);
+        Node* call = NewNode(op, receiver, key, value, attr);
+        PrepareFrameState(call, BailoutId::None());
+        break;
+      }
+      case ObjectLiteral::Property::PROTOTYPE: {
+        const Operator* op =
+            javascript()->CallRuntime(Runtime::kInternalSetPrototype, 2);
+        Node* call = NewNode(op, receiver, value);
+        PrepareFrameState(call, BailoutId::None());
+        break;
+      }
+      case ObjectLiteral::Property::GETTER: {
+        const Operator* op = javascript()->CallRuntime(
+            Runtime::kDefineGetterPropertyUnchecked, 3);
+        Node* call = NewNode(op, receiver, key, value);
+        PrepareFrameState(call, BailoutId::None());
+        break;
+      }
+      case ObjectLiteral::Property::SETTER: {
+        const Operator* op = javascript()->CallRuntime(
+            Runtime::kDefineSetterPropertyUnchecked, 3);
+        Node* call = NewNode(op, receiver, key, value);
+        PrepareFrameState(call, BailoutId::None());
+        break;
+      }
+    }
+  }
+
   // Transform literals that contain functions to fast properties.
   if (expr->has_function()) {
     const Operator* op =
         javascript()->CallRuntime(Runtime::kToFastProperties, 1);
     NewNode(op, literal);
   }
 
   ast_context()->ProduceValue(environment()->Pop());
 }
 
@@ skipping 1243 matching lines @@
 
 BitVector* AstGraphBuilder::GetVariablesAssignedInLoop(
     IterationStatement* stmt) {
   if (loop_assignment_analysis_ == NULL) return NULL;
   return loop_assignment_analysis_->GetVariablesAssignedInLoop(stmt);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8