[turbofan] Port initialization of new.target variable.

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/js-type-feedback.h"
@@ skipping 548 matching lines @@
   Scope* scope = info()->scope();
 
   // Build the arguments object if it is used.
   BuildArgumentsObject(scope->arguments());
 
   // Build rest arguments array if it is used.
   int rest_index;
   Variable* rest_parameter = scope->rest_parameter(&rest_index);
   BuildRestArgumentsArray(rest_parameter, rest_index);
 
-  // Build .this_function var if it is used.
-  BuildThisFunctionVar(scope->this_function_var());
+  // Build assignment to {.this_function} variable if it is used.
+  BuildThisFunctionVariable(scope->this_function_var());
 
-  if (scope->new_target_var() != nullptr) {
-    SetStackOverflow();
-  }
+  // Build assignment to {new.target} variable if it is used.
+  BuildNewTargetVariable(scope->new_target_var());
 
   // Emit tracing call if requested to do so.
   if (FLAG_trace) {
     NewNode(javascript()->CallRuntime(Runtime::kTraceEnter, 0));
   }
 
   // Visit illegal re-declaration and bail out if it exists.
   if (scope->HasIllegalRedeclaration()) {
     AstEffectContext for_effect(this);
     scope->VisitIllegalRedeclaration(this);
@@ skipping 2552 matching lines @@
 
   // Allocate and initialize a new arguments object.
   Node* callee = GetFunctionClosure();
   const Operator* op = javascript()->CallRuntime(Runtime::kNewArguments, 1);
   Node* object = NewNode(op, callee);
 
   // Assign the object to the arguments variable.
   DCHECK(arguments->IsContextSlot() || arguments->IsStackAllocated());
   // This should never lazy deopt, so it is fine to send invalid bailout id.
   FrameStateBeforeAndAfter states(this, BailoutId::None());
-  VectorSlotPair feedback;
-  BuildVariableAssignment(arguments, object, Token::ASSIGN, feedback,
+  BuildVariableAssignment(arguments, object, Token::ASSIGN, VectorSlotPair(),
                           BailoutId::None(), states);
-
   return object;
 }
 
 
 Node* AstGraphBuilder::BuildRestArgumentsArray(Variable* rest, int index) {
   if (rest == NULL) return NULL;
 
   DCHECK(index >= 0);
   const Operator* op = javascript()->CallRuntime(Runtime::kNewRestParamSlow, 2);
   Node* object = NewNode(op, jsgraph()->SmiConstant(index),
                          jsgraph()->SmiConstant(language_mode()));
 
-  // Assign the object to the rest array
+  // Assign the object to the rest parameter variable.
   DCHECK(rest->IsContextSlot() || rest->IsStackAllocated());
   // This should never lazy deopt, so it is fine to send invalid bailout id.
   FrameStateBeforeAndAfter states(this, BailoutId::None());
-  VectorSlotPair feedback;
-  BuildVariableAssignment(rest, object, Token::ASSIGN, feedback,
+  BuildVariableAssignment(rest, object, Token::ASSIGN, VectorSlotPair(),
                           BailoutId::None(), states);
-
   return object;
 }
 
 
-Node* AstGraphBuilder::BuildThisFunctionVar(Variable* this_function_var) {
+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.
   FrameStateBeforeAndAfter states(this, BailoutId::None());
-  VectorSlotPair feedback;
   BuildVariableAssignment(this_function_var, this_function, Token::INIT_CONST,
-                          feedback, BailoutId::None(), states);
+                          VectorSlotPair(), BailoutId::None(), states);
   return this_function;
 }
 
 
+Node* AstGraphBuilder::BuildNewTargetVariable(Variable* new_target_var) {
+  if (new_target_var == nullptr) return nullptr;
+
+  // Retrieve the original constructor in case we are called as a constructor.
+  const Operator* op =
+      javascript()->CallRuntime(Runtime::kGetOriginalConstructor, 0);
+  Node* object = NewNode(op);
+
+  // Assign the object to the {new.target} variable.
+  FrameStateBeforeAndAfter states(this, BailoutId::None());
+  BuildVariableAssignment(new_target_var, object, Token::INIT_CONST,
+                          VectorSlotPair(), BailoutId::None(), states);
+  return object;
+}
+
+
 Node* AstGraphBuilder::BuildHoleCheckSilent(Node* value, Node* for_hole,
                                             Node* not_hole) {
   Node* the_hole = jsgraph()->TheHoleConstant();
   Node* check = NewNode(javascript()->StrictEqual(), value, the_hole);
   return NewNode(common()->Select(kMachAnyTagged, BranchHint::kFalse), check,
                  for_hole, not_hole);
 }
 
 
 Node* AstGraphBuilder::BuildHoleCheckThrow(Node* value, Variable* variable,
@@ skipping 965 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