[Interpreter] Add for/while/do support to the bytecode generator.

src/interpreter/control-flow-builders.h

+// 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.
+
+#ifndef V8_INTERPRETER_CONTROL_FLOW_BUILDERS_H_
+#define V8_INTERPRETER_CONTROL_FLOW_BUILDERS_H_
+
+#include "src/interpreter/bytecode-array-builder.h"
+
+#include "src/zone-containers.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+class ControlFlowBuilder BASE_EMBEDDED {
+ public:
+  explicit ControlFlowBuilder(BytecodeArrayBuilder* builder)
+      : builder_(builder) {}
+  virtual ~ControlFlowBuilder() {}
+
+ protected:
+  BytecodeArrayBuilder* builder() const { return builder_; }
+
+ private:
+  BytecodeArrayBuilder* builder_;
+
+  DISALLOW_COPY_AND_ASSIGN(ControlFlowBuilder);
+};
+
+// A class to help with co-ordinating break and continue statements with
+// their loop.
+// TODO(oth): add support for TF branch/merge info.
+class LoopBuilder : public ControlFlowBuilder {
+ public:
+  explicit LoopBuilder(BytecodeArrayBuilder* builder)
+      : ControlFlowBuilder(builder),
+        continue_sites_(builder->zone()),
+        break_sites_(builder->zone()) {}
+  ~LoopBuilder();
+
+  // These methods should be called by the LoopBuilder owner before
+  // destruction to update sites that emit jumps for break/continue.
+  void SetContinueTarget(const BytecodeLabel& continue_target);
+  void SetBreakTarget(const BytecodeLabel& break_target);
+
+  // These methods are called when visiting break and continue
+  // statements in the AST.  Inserts a jump to a unbound label that is
+  // patched when the corresponding SetContinueTarget/SetBreakTarget
+  // is called.
+  void Break() { EmitJump(&break_sites_); }
+  void Continue() { EmitJump(&continue_sites_); }
+
+ private:
+  void BindLabels(const BytecodeLabel& target, ZoneVector<BytecodeLabel>* site);
+  void EmitJump(ZoneVector<BytecodeLabel>* labels);
+
+  // Unbound labels that identify jumps for continue/break statements
+  // in the code.
+  ZoneVector<BytecodeLabel> continue_sites_;
+  ZoneVector<BytecodeLabel> break_sites_;
+};
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTERPRETER_CONTROL_FLOW_BUILDERS_H_