78 lines
2.2 KiB
C++
78 lines
2.2 KiB
C++
#ifndef DEPTH_GUARD_H_00000000000000000000000000000000000000000000000000000000
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#define DEPTH_GUARD_H_00000000000000000000000000000000000000000000000000000000
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#if defined(_MSC_VER) || \
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(defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || \
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(__GNUC__ >= 4)) // GCC supports "pragma once" correctly since 3.4
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#pragma once
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#endif
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#include "exceptions.h"
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namespace YAML {
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/**
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* @brief The DeepRecursion class
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* An exception class which is thrown by DepthGuard. Ideally it should be
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* a member of DepthGuard. However, DepthGuard is a templated class which means
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* that any catch points would then need to know the template parameters. It is
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* simpler for clients to not have to know at the catch point what was the
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* maximum depth.
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*/
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class DeepRecursion : public ParserException {
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public:
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virtual ~DeepRecursion() = default;
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DeepRecursion(int depth, const Mark& mark_, const std::string& msg_);
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// Returns the recursion depth when the exception was thrown
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int depth() const {
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return m_depth;
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}
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private:
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int m_depth = 0;
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};
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/**
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* @brief The DepthGuard class
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* DepthGuard takes a reference to an integer. It increments the integer upon
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* construction of DepthGuard and decrements the integer upon destruction.
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*
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* If the integer would be incremented past max_depth, then an exception is
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* thrown. This is ideally geared toward guarding against deep recursion.
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*
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* @param max_depth
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* compile-time configurable maximum depth.
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*/
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template <int max_depth = 2000>
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class DepthGuard final {
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public:
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DepthGuard(int & depth_, const Mark& mark_, const std::string& msg_) : m_depth(depth_) {
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++m_depth;
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if ( max_depth <= m_depth ) {
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throw DeepRecursion{m_depth, mark_, msg_};
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}
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}
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DepthGuard(const DepthGuard & copy_ctor) = delete;
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DepthGuard(DepthGuard && move_ctor) = delete;
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DepthGuard & operator=(const DepthGuard & copy_assign) = delete;
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DepthGuard & operator=(DepthGuard && move_assign) = delete;
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~DepthGuard() {
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--m_depth;
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}
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int current_depth() const {
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return m_depth;
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}
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private:
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int & m_depth;
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};
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} // namespace YAML
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#endif // DEPTH_GUARD_H_00000000000000000000000000000000000000000000000000000000
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