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