Wave: a Standard conformant C++ preprocessor library

/*=============================================================================
    Wave: A Standard compliant C++ preprocessor

    Copyright (c) 2001-2003 Hartmut Kaiser
    http://spirit.sourceforge.net/

    Permission to copy, use, modify, sell and distribute this software
    is granted provided this copyright notice appears in all copies.
    This software is provided "as is" without express or implied
    warranty, and with no claim as to its suitability for any purpose.

    See Copyright.txt for full copyright notices and acknowledgements.
=============================================================================*/

#if !defined(CPPLEXER_EXCEPTIONS_HPP_1A09DE1A_6D1F_4091_AF7F_5F13AB0D31AB_INCLUDED)
#define CPPLEXER_EXCEPTIONS_HPP_1A09DE1A_6D1F_4091_AF7F_5F13AB0D31AB_INCLUDED

#include <exception>
#include <string>

#include <boost/assert.hpp>
#include <boost/config.hpp>

///////////////////////////////////////////////////////////////////////////////
// helper macro for throwing exceptions
#ifdef BOOST_NO_STRINGSTREAM
#include <strstream>
#define CPPLEXER_THROW(cls, code, msg, line, column, name) \
    { \
    using namespace wave::cpplexer; \
    std::strstream stream; \
        stream << cls::severity_text(cls::code) << ": " \
        << cls::error_text(cls::code); \
    if (msg[0] != 0) stream << ": " << msg; \
    stream << std::ends; \
    std::string throwmsg = stream.str(); stream.freeze(false); \
    throw cls(throwmsg.c_str(), cls::code, line, column, name); \
    } \
    /**/
#else
#include <sstream>
#define CPPLEXER_THROW(cls, code, msg, line, column, name) \
    { \
    using namespace wave::cpplexer; \
    std::stringstream stream; \
        stream << cls::severity_text(cls::code) << ": " \
        << cls::error_text(cls::code); \
    if (msg[0] != 0) stream << ": " << msg; \
    stream << std::ends; \
    throw cls(stream.str().c_str(), cls::code, line, column, name); \
    } \
    /**/
#endif // BOOST_NO_STRINGSTREAM

///////////////////////////////////////////////////////////////////////////////
namespace wave {
namespace cpplexer {

///////////////////////////////////////////////////////////////////////////////
// exception severity
namespace util {

    enum severity {
        severity_remark = 0,
        severity_warning,
        severity_error,
        severity_fatal
    };
    
    inline char const *
    get_severity(severity level) 
    {
        static char const *severity_text[] = 
        {
            "remark",           // severity_remark
            "warning",          // severity_warning
            "error",            // severity_error
            "fatal error"       // severity_fatal
        };
        BOOST_ASSERT(severity_remark <= level && level <= severity_fatal);
        return severity_text[level];
    }
}

///////////////////////////////////////////////////////////////////////////////
//  cpplexer_exception, the base class for all specific C++ lexer exceptions 
class cpplexer_exception
:   public std::exception
{
public:
    cpplexer_exception(int line_, int column_, char const *filename_) throw() 
    :   line(line_), column(column_) 
    {
        unsigned int off = 0;
        while (off < sizeof(filename) && *filename_)
            filename[off++] = *filename_++;
        filename[off] = 0;
    }
    ~cpplexer_exception() throw() {}
    
    virtual char const *what() const throw() = 0;   // to be overloaded
    virtual char const *description() const throw() = 0;
    
    int line_no() const throw() { return line; }
    int column_no() const throw() { return column; }
    char const *file_name() const throw() { return filename; }
    
protected:
    char filename[512];
    int line;
    int column;
};

///////////////////////////////////////////////////////////////////////////////
// lexing_exception error
class lexing_exception :
    public cpplexer_exception
{
public:
    enum error_code {
        unexpected_error = 0,
        universal_char_invalid = 1,
        universal_char_base_charset = 2,
        universal_char_not_allowed = 3,
        generic_lexing_error = 4
    };

    lexing_exception(char const *what_, error_code code, int line_, 
        int column_, char const *filename_) throw() 
    :   cpplexer_exception(line_, column_, filename_), 
        level(severity_level(code))
    {
        unsigned int off = 0;
        while (off < sizeof(buffer) && *what_)
            buffer[off++] = *what_++;
        buffer[off] = 0;
    }
    ~lexing_exception() throw() {}
    
    virtual char const *what() const throw()
    {
        return "wave::cpplexer::lexing_exception";
    }
    virtual char const *description() const throw()
    {
        return buffer;
    }
    util::severity get_severity()
    {
        return level;
    }

    static char const *error_text(int code)
    {
    // error texts in this array must apear in the same order as the items in
    // the error enum above
        static char const *preprocess_exception_errors[] = {
            "unexpected error (should not happen)",     // unexpected_error
            "universal character name specifies an invalid character",  // universal_char_invalid
            "a universal character name cannot designate a character in the "
                "basic character set",                  // universal_char_base_charset
            "this universal character is not allowed in an identifier", // universal_char_not_allowed 
            "generic lexing error"                      // generic_lexing_error
        };
        return preprocess_exception_errors[code];
    }

    static util::severity severity_level(int code)
    {
        static util::severity preprocess_exception_severity[] = {
            util::severity_fatal,               // unexpected_error
            util::severity_error,               // universal_char_invalid
            util::severity_error,               // universal_char_base_charset
            util::severity_error,               // universal_char_not_allowed
            util::severity_error                // generic_lexing_error                
        };
        return preprocess_exception_severity[code];
    }
    static char const *severity_text(int code)
    {
        return util::get_severity(severity_level(code));
    }

private:
    char buffer[512];
    util::severity level;
};

///////////////////////////////////////////////////////////////////////////////
}   // namespace cpplexer
}   // namespace wave

#endif // !defined(CPPLEXER_EXCEPTIONS_HPP_1A09DE1A_6D1F_4091_AF7F_5F13AB0D31AB_INCLUDED)