//  (C) Copyright Gennadiy Rozental 2001-2008.
//  (C) Copyright Beman Dawes 2001.
//  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)

//  See http://www.boost.org/libs/test for the library home page.
//
//  File        : $RCSfile$
//
//  Version     : $Revision: 49312 $
//
//  Description : defines abstract monitor interfaces and implements execution exception
//  The original Boost Test Library included an implementation detail function
//  named catch_exceptions() which caught otherwise uncaught C++ exceptions.
//  It was derived from an existing test framework by Beman Dawes.  The
//  intent was to expand later to catch other detectable but platform dependent
//  error events like Unix signals or Windows structured C exceptions.
//
//  Requests from early adopters of the Boost Test Library included
//  configurable levels of error message detail, elimination of templates,
//  separation of error reporting, and making the catch_exceptions() facilities
//  available as a public interface.  Support for unit testing also stretched
//  the function based design.  Implementation within the header became less
//  attractive due to the need to include many huge system dependent headers,
//  although still preferable in certain cases.
//
//  All those issues have been addressed by introducing the class-based
//  design presented here.
// ***************************************************************************

#ifndef BOOST_TEST_EXECUTION_MONITOR_HPP_071894GER
#define BOOST_TEST_EXECUTION_MONITOR_HPP_071894GER

// Boost.Test
#include <boost/test/detail/global_typedef.hpp>
#include <boost/test/detail/fwd_decl.hpp>
#include <boost/test/utils/callback.hpp>
#include <boost/test/utils/class_properties.hpp>

// Boost
#include <boost/scoped_ptr.hpp>
#include <boost/scoped_array.hpp>
#include <boost/type.hpp>
#include <boost/cstdlib.hpp>

#include <boost/test/detail/suppress_warnings.hpp>

//____________________________________________________________________________//

namespace boost {

namespace detail {

// ************************************************************************** //
// **************       detail::translate_exception_base       ************** //
// ************************************************************************** //

class BOOST_TEST_DECL translate_exception_base {
public:
    // Constructor
    explicit    translate_exception_base( boost::scoped_ptr<translate_exception_base>& next )
    {
        next.swap( m_next );
    }

    // Destructor
    virtual     ~translate_exception_base() {}

    virtual int operator()( unit_test::callback0<int> const& F ) = 0;

protected:
    // Data members
    boost::scoped_ptr<translate_exception_base> m_next;
};

} // namespace detail

// ************************************************************************** //
// **************              execution_exception             ************** //
// ************************************************************************** //
    
//  design rationale: fear of being out (or nearly out) of memory.
    
class BOOST_TEST_DECL execution_exception {
    typedef boost::unit_test::const_string const_string;
public:
    enum error_code {
        //  These values are sometimes used as program return codes.
        //  The particular values have been chosen to avoid conflicts with
        //  commonly used program return codes: values < 100 are often user
        //  assigned, values > 255 are sometimes used to report system errors.
        //  Gaps in values allow for orderly expansion.
        
        no_error               = 0,   // for completeness only; never returned
        user_error             = 200, // user reported non-fatal error
        cpp_exception_error    = 205, // see note (1) below
        system_error           = 210, // see note (2) below
        timeout_error          = 215, // only detectable on certain platforms
        user_fatal_error       = 220, // user reported fatal error
        system_fatal_error     = 225  // see note (2) below
        
        //  Note 1: Only uncaught C++ exceptions are treated as errors.
        //  If the application catches a C++ exception, it will never reach
        //  the execution_monitor.
        
        //  Note 2: These errors include Unix signals and Windows structured
        //  exceptions.  They are often initiated by hardware traps.
        //
        //  The implementation decides what is a fatal_system_exception and what is
        //  just a system_exception.  Fatal errors are so likely to have corrupted
        //  machine state (like a stack overflow or addressing exception) that it
        //  is unreasonable to continue execution.
    };
    
    // Constructor
    execution_exception( error_code ec_, const_string what_msg_ ) // max length 256 inc '\0'
    : m_error_code( ec_ ), m_what( what_msg_ ) {}

    // access methods
    error_code      code() const { return m_error_code; }
    const_string    what() const { return m_what; }

private:
    // Data members
    error_code      m_error_code;
    const_string    m_what;
}; // execution_exception

// ************************************************************************** //
// **************               execution_monitor              ************** //
// ************************************************************************** //

class BOOST_TEST_DECL execution_monitor {
public:
    // Constructor
    execution_monitor()
    : p_catch_system_errors( true )
    , p_auto_start_dbg( false )
    , p_timeout( 0 )
    , p_use_alt_stack( true )
    , p_detect_fp_exceptions( false )
    {}

    // Public properties
    
    //  The p_catch_system_errors parameter specifies whether the monitor should 
    //  try to catch system errors/exceptions that would cause program to crash 
    //  in regular case
    unit_test::readwrite_property<bool> p_catch_system_errors; 
    //  The p_auto_start_dbg parameter specifies whether the monitor should 
    //  try to attach debugger in case of caught system error
    unit_test::readwrite_property<bool> p_auto_start_dbg;
    //  The p_timeout parameter specifies the seconds that elapse before
    //  a timer_error occurs.  May be ignored on some platforms.
    unit_test::readwrite_property<int>  p_timeout;
    //  The p_use_alt_stack parameter specifies whether the monitor should
    //  use alternative stack for the signal catching
    unit_test::readwrite_property<bool> p_use_alt_stack;
    //  The p_detect_fp_exceptions parameter specifies whether the monitor should
    //  try to detect hardware floating point exceptions
    unit_test::readwrite_property<bool> p_detect_fp_exceptions;

    int         execute( unit_test::callback0<int> const& F ); 
    //  Returns:  Value returned by function call F().
    //
    //  Effects:  Calls executes supplied function F inside a try/catch block which also may
    //  include other unspecified platform dependent error detection code.
    //
    //  Throws: execution_exception on an uncaught C++ exception,
    //  a hardware or software signal, trap, or other exception.
    //
    //  Note: execute() doesn't consider it an error for F to return a non-zero value.
    
    // register custom (user supplied) exception translator
    template<typename Exception, typename ExceptionTranslator>
    void        register_exception_translator( ExceptionTranslator const& tr, boost::type<Exception>* = 0 );

private:
    // implementation helpers
    int         catch_signals( unit_test::callback0<int> const& F );

    // Data members
    boost::scoped_ptr<detail::translate_exception_base> m_custom_translators;
    boost::scoped_array<char>                           m_alt_stack;
}; // execution_monitor

namespace detail {

// ************************************************************************** //
// **************         detail::translate_exception          ************** //
// ************************************************************************** //

template<typename Exception, typename ExceptionTranslator>
class translate_exception : public translate_exception_base
{
    typedef boost::scoped_ptr<translate_exception_base> base_ptr;
public:
    explicit    translate_exception( ExceptionTranslator const& tr, base_ptr& next )
    : translate_exception_base( next ), m_translator( tr ) {}

    int operator()( unit_test::callback0<int> const& F )
    {
        try {
            return m_next ? (*m_next)( F ) : F();
        } catch( Exception const& e ) {
            m_translator( e );
            return boost::exit_exception_failure;
        }
    }

private:
    // Data members
    ExceptionTranslator m_translator;
};

} // namespace detail

template<typename Exception, typename ExceptionTranslator>
void
execution_monitor::register_exception_translator( ExceptionTranslator const& tr, boost::type<Exception>* )
{
    m_custom_translators.reset( 
        new detail::translate_exception<Exception,ExceptionTranslator>( tr,m_custom_translators ) );
}

// ************************************************************************** //
// **************               execution_aborted              ************** //
// ************************************************************************** //

struct execution_aborted {};

// ************************************************************************** //
// **************                  system_error                ************** //
// ************************************************************************** //

class system_error {
public:
    // Constructor
    explicit    system_error( char const* exp );

    unit_test::readonly_property<long>          p_errno; 
    unit_test::readonly_property<char const*>   p_failed_exp; 
};

#define BOOST_TEST_SYS_ASSERT( exp ) if( (exp) ) ; else throw ::boost::system_error( BOOST_STRINGIZE( exp ) )

}  // namespace boost

//____________________________________________________________________________//

#include <boost/test/detail/enable_warnings.hpp>

#endif
