boost/exception/diagnostic_information.hpp

//Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc.

//Distributed under the Boost Software License, Version 1.0. (See accompanying
//file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#ifndef UUID_0552D49838DD11DD90146B8956D89593
#define UUID_0552D49838DD11DD90146B8956D89593

#include <boost/config.hpp>
#include <boost/exception/get_error_info.hpp>
#include <boost/exception/detail/exception_ptr_base.hpp>
#include <boost/utility/enable_if.hpp>
#include <exception>
#include <sstream>
#include <string>

namespace
boost
    {
    namespace
    exception_detail
        {
        template <class T>
        struct
        enable_boost_exception_overload
            {
            struct yes { char q[100]; };
            typedef char no;
            static yes check(exception const *);
            static no check(...);
            enum e { value=sizeof(check((T*)0))==sizeof(yes) };
            };

        template <class T>
        struct
        enable_std_exception_overload
            {
            struct yes { char q[100]; };
            typedef char no;
            static yes check(std::exception const *);
            static no check(...);
            enum e { value = !enable_boost_exception_overload<T>::value && sizeof(check((T*)0))==sizeof(yes) };
            };

        inline
        char const *
        get_diagnostic_information( exception const & x )
            {
            if( error_info_container * c=x.data_.get() )
#ifndef BOOST_NO_EXCEPTIONS
                try
                    {
#endif
                    return c->diagnostic_information();
#ifndef BOOST_NO_EXCEPTIONS
                    }
                catch(...)
                    {
                    }
#endif
            return 0;
            }

        inline
        std::string
        diagnostic_information_impl( boost::exception const * be, std::exception const * se )
            {
            BOOST_ASSERT(be||se);
#ifndef BOOST_NO_RTTI
            if( !se )
                se = dynamic_cast<std::exception const *>(be);
            if( !be )
                be = dynamic_cast<boost::exception const *>(se);
#endif
            std::ostringstream tmp;
            if( be )
                {
                if( char const * const * f=get_error_info<throw_file>(*be) )
                    {
                    tmp << *f;
                    if( int const * l=get_error_info<throw_line>(*be) )
                        tmp << '(' << *l << "): ";
                    }
                tmp << "Throw in function ";
                if( char const * const * fn=get_error_info<throw_function>(*be) )
                    tmp << *fn;
                else
                    tmp << "(unknown)";
                tmp << '\n';
                }
#ifndef BOOST_NO_RTTI
            tmp << std::string("Dynamic exception type: ") <<
                (be?BOOST_EXCEPTION_DYNAMIC_TYPEID(*be):BOOST_EXCEPTION_DYNAMIC_TYPEID(*se)).name() << '\n';
#endif
            if( se )
                tmp << "std::exception::what: " << se->what() << '\n';
            if( be )
                if( char const * s=exception_detail::get_diagnostic_information(*be) )
                    if( *s )
                        tmp << s;
            return tmp.str();
            }
        }

    template <class T>
    inline
    typename enable_if<exception_detail::enable_boost_exception_overload<T>,std::string>::type
    diagnostic_information( T const & e )
        {
        return exception_detail::diagnostic_information_impl(&e,0);
        }

    template <class T>
    inline
    typename enable_if<exception_detail::enable_std_exception_overload<T>,std::string>::type
    diagnostic_information( T const & e )
        {
        return exception_detail::diagnostic_information_impl(0,&e);
        }
    }

#ifndef BOOST_NO_EXCEPTIONS
#include <boost/exception/current_exception_cast.hpp>
namespace
boost
    {
    inline
    std::string
    current_exception_diagnostic_information()
        {
        boost::exception const * be=current_exception_cast<boost::exception const>();
        std::exception const * se=current_exception_cast<std::exception const>();
        if( be || se )
            return exception_detail::diagnostic_information_impl(be,se);
        else
            return "No diagnostic information available.";
        }

    inline
    std::string
    diagnostic_information( exception_detail::exception_ptr_base const & p )
        {
        if( !p._empty() )
            try
                {
                p._rethrow();
                }
            catch(
            ... )
                {
                return current_exception_diagnostic_information();
                }
        return "<empty>";
        }
    }
#endif

#endif