butl/diagnostics.cxx


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// file      : butl/diagnostics.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#include <butl/diagnostics>

#include <iostream> // cerr

using namespace std;

namespace butl
{
  ostream* diag_stream = &cerr;

  void diag_record::
  flush () const
  {
    if (!empty_)
    {
      os.put ('\n');
      *diag_stream << os.str ();
      diag_stream->flush ();

      empty_ = true;

      if (epilogue_ != nullptr)
        epilogue_ (*this); // Can throw.
    }
  }

  diag_record::
  ~diag_record () noexcept (false)
  {
    // Don't flush the record if this destructor was called as part of the
    // stack unwinding.
    //
#ifdef __cpp_lib_uncaught_exceptions
    if (uncaught_ == std::uncaught_exceptions ())
      flush ();
#else
    // Fallback implementation. Right now this means we cannot use this
    // mechanism in destructors, which is not a big deal, except for one
    // place: exception_guard. Thus the ugly special check.
    //
    if (!std::uncaught_exception () || exception_unwinding_dtor ())
      flush ();
#endif
  }
}