| // 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 playground2 { |
| |
| 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 playground2 |
| |
| #endif // SANDBOX_LINUX_SECCOMP_BPF_BASICBLOCK_H__ |