[Interpreter] Minimal bytecode generator.

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 <stack>
+
+#include "src/compiler.h"
+#include "src/interpreter/bytecode-generator.h"
+#include "src/objects.h"
+#include "src/scopes.h"
+#include "src/token.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+BytecodeGenerator::BytecodeGenerator(Isolate* isolate, Zone* zone)
+    : builder_(isolate) {
+  InitializeAstVisitor(isolate, zone);
+}
+
+
+BytecodeGenerator::~BytecodeGenerator() {}
+
+
+Handle<BytecodeArray> BytecodeGenerator::MakeBytecode(CompilationInfo* info) {
+  set_scope(info->scope());
+  DCHECK(scope()->is_function_scope());
+
+  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());
+
+  // Visit statements in the function body.
+  VisitStatements(info->function()->body());
+
+  set_scope(nullptr);
+  return builder_.ToBytecodeArray();
+}
+
+
+void BytecodeGenerator::VisitBlock(Block* node) {
+  if (node->scope() == NULL) {
+    // Visit statements in the same scope, no declarations.
+    VisitStatements(node->statements());
+  } else {
+    // Visit declarations and statements in a block scope.
+    if (node->scope()->ContextLocalCount() > 0) {
+      UNIMPLEMENTED();
+    } else {
+      VisitDeclarations(node->scope()->declarations());
+      VisitStatements(node->statements());
+    }
+  }
+}
+
+
+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, ie variable index.

[rmcilroy, 2015/08/14 09:31:17]

/s/ie/i.e.

[oth, 2015/08/17 08:05:48]

Done.

+      break;
+    case VariableLocation::CONTEXT:
+    case VariableLocation::LOOKUP:
+      UNIMPLEMENTED();
+      break;
+  }
+}
+
+
+void BytecodeGenerator::VisitFunctionDeclaration(FunctionDeclaration* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitImportDeclaration(ImportDeclaration* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitExportDeclaration(ExportDeclaration* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitExpressionStatement(ExpressionStatement* stmt) {
+  stmt->expression()->Accept(this);
+}
+
+
+void BytecodeGenerator::VisitEmptyStatement(EmptyStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitIfStatement(IfStatement* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitContinueStatement(ContinueStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitBreakStatement(BreakStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitReturnStatement(ReturnStatement* node) {
+  Visit(node->expression());
+  builder().Return();
+}
+
+
+void BytecodeGenerator::VisitWithStatement(WithStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitSwitchStatement(SwitchStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitCaseClause(CaseClause* clause) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitDoWhileStatement(DoWhileStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitWhileStatement(WhileStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitForStatement(ForStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitForInStatement(ForInStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitForOfStatement(ForOfStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitTryCatchStatement(TryCatchStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitDebuggerStatement(DebuggerStatement* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitFunctionLiteral(FunctionLiteral* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitClassLiteral(ClassLiteral* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitNativeFunctionLiteral(
+    NativeFunctionLiteral* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitConditional(Conditional* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitLiteral(Literal* expr) {
+  DCHECK(!expr->IsPropertyName());

[rmcilroy, 2015/08/14 09:31:17]

Could you make this an if/else or switch statement with the propertyName case
being unimplemented().

[oth, 2015/08/17 08:05:49]

Done.

+  Handle<Object> value = expr->value();
+  if (value->IsSmi()) {
+    builder().LoadLiteral(Smi::cast(*value));
+  } else if (value->IsUndefined()) {
+    builder().LoadUndefined();
+  } else if (value->IsTrue()) {
+    builder().LoadTrue();
+  } else if (value->IsFalse()) {
+    builder().LoadFalse();
+  } else if (value->IsNull()) {
+    builder().LoadNull();
+  } else if (value->IsTheHole()) {
+    builder().LoadTheHole();
+  } else {
+    UNIMPLEMENTED();
+  }
+}
+
+
+void BytecodeGenerator::VisitRegExpLiteral(RegExpLiteral* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitArrayLiteral(ArrayLiteral* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitVariableProxy(VariableProxy* proxy) {
+  Variable* variable = proxy->var();
+  DCHECK(variable->location() == VariableLocation::LOCAL);

[rmcilroy, 2015/08/14 09:31:17]

Could you do this as a switch statement, with all other cases falling through to
undefined for now.

[oth, 2015/08/17 08:05:49]

Done.

+  Register source(variable->index());
+  builder().LoadAccumulatorWithRegister(source);
+}
+
+
+void BytecodeGenerator::VisitAssignment(Assignment* expr) {
+  DCHECK(expr->target()->IsValidReferenceExpression());
+
+  // Left-hand side can only be a property, a global or a variable slot.
+  Property* property = expr->target()->AsProperty();
+  LhsKind assign_type = Property::GetAssignType(property);
+  int destination = -1;
+  switch (assign_type) {
+    case VARIABLE: {
+      Variable* variable = expr->target()->AsVariableProxy()->var();
+      destination = variable->index();
+      DCHECK(variable->location() == VariableLocation::LOCAL);
+      break;
+    }
+    case NAMED_PROPERTY:
+    case KEYED_PROPERTY:
+    case NAMED_SUPER_PROPERTY:
+    case KEYED_SUPER_PROPERTY:
+      UNIMPLEMENTED();
+  }
+
+  DCHECK(!expr->is_compound());
+  Visit(expr->value());
+  builder().StoreAccumulatorInRegister(Register(destination));

[rmcilroy, 2015/08/14 09:31:17]

We would only be storing the value in a register if it is a VARIABLE case,
wouldn't we? Could you move the switch down so this is part of the VARIABLE case
and destination can be a Register instead of an index?

[oth, 2015/08/17 08:05:49]

Done.

+}
+
+
+void BytecodeGenerator::VisitYield(Yield* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitThrow(Throw* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitProperty(Property* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitCall(Call* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitCallNew(CallNew* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitCallRuntime(CallRuntime* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitUnaryOperation(UnaryOperation* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitCountOperation(CountOperation* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitBinaryOperation(BinaryOperation* binop) {
+  switch (binop->op()) {
+    case Token::COMMA:
+    case Token::OR:
+    case Token::AND:
+      UNIMPLEMENTED();
+      break;
+    default:
+      VisitArithmeticExpression(binop);
+      break;
+  }
+}
+
+
+void BytecodeGenerator::VisitCompareOperation(CompareOperation* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitSpread(Spread* node) { UNIMPLEMENTED(); }
+
+
+void BytecodeGenerator::VisitThisFunction(ThisFunction* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitSuperCallReference(SuperCallReference* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitSuperPropertyReference(
+    SuperPropertyReference* node) {
+  UNIMPLEMENTED();
+}
+
+
+void BytecodeGenerator::VisitArithmeticExpression(BinaryOperation* binop) {
+  Token::Value op = binop->op();
+  Expression* left = binop->left();
+  Expression* right = binop->right();
+
+  TemporaryRegisterScope temporary_register_scope(&builder_);
+  Register temporary = temporary_register_scope.NewRegister();
+
+  Visit(left);
+  builder().StoreAccumulatorInRegister(temporary);
+  Visit(right);
+  builder().BinaryOperation(op, temporary);
+}
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8