Update from chromium 62675d9fb31fb8cedc40f68e78e8445a74f362e7

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__