[Interpreter] Add support for parameter variables.

src/interpreter/bytecode-generator.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/interpreter/bytecode-generator.h"
 
 #include <stack>
 
 #include "src/compiler.h"
 #include "src/objects.h"
@@ skipping 12 matching lines @@
 
 BytecodeGenerator::~BytecodeGenerator() {}
 
 
 Handle<BytecodeArray> BytecodeGenerator::MakeBytecode(CompilationInfo* info) {
   set_scope(info->scope());
 
   // This a temporary guard (oth).
   DCHECK(scope()->is_function_scope());
 
+  builder().set_parameter_count(info->num_parameters_including_this());
   builder().set_locals_count(scope()->num_stack_slots());
 
   // Visit implicit declaration of the function name.
   if (scope()->is_function_scope() && scope()->function() != NULL) {
     VisitVariableDeclaration(scope()->function());
   }
 
   // Visit declarations within the function scope.
   VisitDeclarations(scope()->declarations());
 
@@ skipping 22 matching lines @@
 
 
 void BytecodeGenerator::VisitVariableDeclaration(VariableDeclaration* decl) {
   Variable* variable = decl->proxy()->var();
   switch (variable->location()) {
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED:
       UNIMPLEMENTED();
       break;
     case VariableLocation::PARAMETER:
-      UNIMPLEMENTED();
-      break;
     case VariableLocation::LOCAL:
       // Details stored in scope, i.e. variable index.
       break;
     case VariableLocation::CONTEXT:
     case VariableLocation::LOOKUP:
       UNIMPLEMENTED();
       break;
   }
 }
 
@@ skipping 154 matching lines @@
 
 
 void BytecodeGenerator::VisitVariableProxy(VariableProxy* proxy) {
   Variable* variable = proxy->var();
   switch (variable->location()) {
     case VariableLocation::LOCAL: {
       Register source(variable->index());
       builder().LoadAccumulatorWithRegister(source);
       break;
     }
+    case VariableLocation::PARAMETER: {
+      // The parameter indices are shifted by 1 (receiver is variable
+      // index -1 but is parameter index 0 in BytecodeArrayBuilder).
+      Register source(builder().Parameter(variable->index() + 1));
+      builder().LoadAccumulatorWithRegister(source);
+      break;
+    }
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED:
-    case VariableLocation::PARAMETER:
     case VariableLocation::CONTEXT:
     case VariableLocation::LOOKUP:
       UNIMPLEMENTED();
   }
 }
 
 
 void BytecodeGenerator::VisitAssignment(Assignment* expr) {
   DCHECK(expr->target()->IsValidReferenceExpression());
 
@@ skipping 102 matching lines @@
 
   Visit(left);
   builder().StoreAccumulatorInRegister(temporary);
   Visit(right);
   builder().BinaryOperation(op, temporary);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8