PyException.h

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#ifndef CPYRT_PYEXCEPTION_H
#define CPYRT_PYEXCEPTION_H
 
//////////////////////////////////////////////////////////////////////////////
//                                                                          //
// PyException                                                             //
//                                                                          //
// Purpose: A C++ exception class for throwing python exceptions            //
//          through C++ code.                                               //
// Created: Apr, 2004, Scott Snyder, from the version in D0's python_util.  //
//                                                                          //
// The situation is:                                                        //
//   - We're calling C++ code from python.                                  //
//   - The C++ code can call back to python.                                //
//   - What to do then if the python callback throws an exception?          //
//                                                                          //
// We need to get the control flow back to where cpyrt calls C++.        //
// To do that we throw a TPyException.                                      //
// We can then catch this exception when we do the C++ call.                //
//                                                                          //
// Note that we don't need to save any state in the exception -- it's       //
// already in the python error info variables.                              //
// (??? Actually, if the program is multithreaded, this is dangerous        //
// if the code has released and reacquired the lock along the call chain.   //
// Punt on this for now, though.)                                           //
//                                                                          //
//////////////////////////////////////////////////////////////////////////////
 
// Standard
#include <exception>
#include <string>
 
// Bindings
#include "cpyrt/CommonDefs.h"
 
namespace cppjit::cpyrt {
 
class CPYRT_CLASS_EXTERN PyException : public std::exception {
public:
  PyException();
  ~PyException() noexcept override;
 
  // give reason for raised exception
  const char* what() const noexcept override;
 
  // clear Python error, to allow full error handling C++ side
  void clear() const noexcept;
 
private:
  std::string fMsg;
};
 
} // namespace cppjit::cpyrt
 
#endif // !CPYRT_PYEXCEPTION_H