CodeGen: rewrite implementation [3/3]

sandbox/linux/seccomp-bpf/basicblock.h

-// Copyright (c) 2012 The Chromium 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 SANDBOX_LINUX_SECCOMP_BPF_BASICBLOCK_H__
-#define SANDBOX_LINUX_SECCOMP_BPF_BASICBLOCK_H__
-
-#include <vector>
-
-#include "sandbox/linux/seccomp-bpf/instruction.h"
-
-namespace sandbox {
-
-struct BasicBlock {
-  BasicBlock();
-  ~BasicBlock();
-
-  // Our implementation of the code generator uses a "Less" operator to
-  // identify common sequences of basic blocks. This would normally be
-  // really easy to do, but STL requires us to wrap the comparator into
-  // a class. We begrudgingly add some code here that provides this wrapping.
-  template <class T>
-  class Less {
-   public:
-    Less(const T& data,
-         int (*cmp)(const BasicBlock*, const BasicBlock*, const T& data))
-        : data_(data), cmp_(cmp) {}
-
-    bool operator()(const BasicBlock* a, const BasicBlock* b) const {
-      return cmp_(a, b, data_) < 0;
-    }
-
-   private:
-    const T& data_;
-    int (*cmp_)(const BasicBlock*, const BasicBlock*, const T&);
-  };
-
-  // Basic blocks are essentially nothing more than a set of instructions.
-  std::vector<Instruction*> instructions;
-
-  // In order to compute relative branch offsets we need to keep track of
-  // how far our block is away from the very last basic block. The "offset_"
-  // is measured in number of BPF instructions.
-  int offset;
-};
-
-}  // namespace sandbox
-
-#endif  // SANDBOX_LINUX_SECCOMP_BPF_BASICBLOCK_H__