Wave: a Standard conformant C++ preprocessor library

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

    Copyright (c) 2001-2004 Hartmut Kaiser
    http://spirit.sourceforge.net/

    Use, modification and distribution is subject to 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 Copyright.txt for full 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_LEXER_NS; \
    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_LEXER_NS; \
    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_LEXER_NS::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 appear 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)