Basic TurboFan support for rest arguments.

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/ast/scopes.h"
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
@@ skipping 3211 matching lines @@
   FrameStateBeforeAndAfter states(this, BailoutId::None());
   BuildVariableAssignment(arguments, object, Token::ASSIGN, VectorSlotPair(),
                           BailoutId::None(), states);
   return object;
 }
 
 
 Node* AstGraphBuilder::BuildRestArgumentsArray(Variable* rest, int index) {
   if (rest == NULL) return NULL;
 
-  // TODO(mvstanton): Handle rest arguments.
-  SetStackOverflow();
-  return jsgraph()->UndefinedConstant();
+  // Allocate and initialize a new arguments object.
+  CreateArgumentsParameters::Type type = CreateArgumentsParameters::kRestArray;
+  const Operator* op = javascript()->CreateArguments(type, index);
+  Node* object = NewNode(op, GetFunctionClosure());
+  PrepareFrameState(object, BailoutId::None());
+
+  // Assign the object to the {rest} variable. This should never lazy
+  // deopt, so it is fine to send invalid bailout id.
+  DCHECK(rest->IsContextSlot() || rest->IsStackAllocated());
+  FrameStateBeforeAndAfter states(this, BailoutId::None());
+  BuildVariableAssignment(rest, object, Token::ASSIGN, VectorSlotPair(),
+                          BailoutId::None(), states);
+  return object;
 }
 
 
 Node* AstGraphBuilder::BuildThisFunctionVariable(Variable* this_function_var) {
   if (this_function_var == nullptr) return nullptr;
 
   // Retrieve the closure we were called with.
   Node* this_function = GetFunctionClosure();
 
   // Assign the object to the {.this_function} variable. This should never lazy
@@ skipping 1101 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8