boost/libs/wave/samples/waveidl/idllexer/idl_re.hpp

/*=============================================================================
    Boost.Wave: A Standard compliant C++ preprocessor library

    Sample: Re2C based IDL lexer
    
    http://www.boost.org/

    Copyright (c) 2001-2010 Hartmut Kaiser. 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)
=============================================================================*/

#if !defined(BOOST_IDL_RE_HPP_BD62775D_1659_4684_872C_03C02543C9A5_INCLUDED)
#define BOOST_IDL_RE_HPP_BD62775D_1659_4684_872C_03C02543C9A5_INCLUDED

#include <cstdio>

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

#if defined(BOOST_HAS_UNISTD_H)
#include <unistd.h>
#else
#include <io.h>
#endif

#include <boost/assert.hpp>
#include <boost/detail/workaround.hpp>

// reuse the token ids and re2c helper functions from the default C++ lexer
#include <boost/wave/token_ids.hpp>
#include <boost/wave/cpplexer/re2clex/aq.hpp>
#include <boost/wave/cpplexer/re2clex/scanner.hpp>
#include <boost/wave/cpplexer/cpplexer_exceptions.hpp>

#define BOOST_WAVE_BSIZE     196608

#define RE2C_ASSERT BOOST_ASSERT

#if defined(_MSC_VER) && !defined(__COMO__)
#pragma warning (disable: 4101)     // 'foo' : unreferenced local variable
#pragma warning (disable: 4102)     // 'foo' : unreferenced label
#endif

#define YYCTYPE   uchar
#define YYCURSOR  cursor
#define YYLIMIT   s->lim
#define YYMARKER  s->ptr
#define YYFILL(n) {cursor = fill(s, cursor);}

//#define BOOST_WAVE_RET(i)    {s->cur = cursor; return (i);}
#define BOOST_WAVE_RET(i)    \
    { \
        s->line += count_backslash_newlines(s, cursor); \
        s->cur = cursor; \
        return (i); \
    } \
    /**/



///////////////////////////////////////////////////////////////////////////////
namespace boost {
namespace wave {
namespace idllexer {
namespace re2clex {

template<typename Iterator>
int
get_one_char(boost::wave::cpplexer::re2clex::Scanner<Iterator> *s)
{
    using namespace boost::wave::cpplexer::re2clex;
    RE2C_ASSERT(s->first <= s->act && s->act <= s->last);
    if (s->act < s->last)
        return *(s->act)++;
    return -1;
}

template<typename Iterator>
std::ptrdiff_t
rewind_stream (boost::wave::cpplexer::re2clex::Scanner<Iterator> *s, int cnt)
{
    s->act += cnt;
    RE2C_ASSERT(s->first <= s->act && s->act <= s->last);
    return s->act - s->first;
}

template<typename Iterator>
std::size_t
get_first_eol_offset(boost::wave::cpplexer::re2clex::Scanner<Iterator>* s)
{
    if (!AQ_EMPTY(s->eol_offsets))
    {
        return s->eol_offsets->queue[s->eol_offsets->head];
    }
    else
    {
        return (unsigned int)-1;
    }
}

template<typename Iterator>
void
adjust_eol_offsets(boost::wave::cpplexer::re2clex::Scanner<Iterator>* s,
    std::size_t adjustment)
{
    boost::wave::cpplexer::re2clex::aq_queue q;
    std::size_t i;

    if (!s->eol_offsets)
        s->eol_offsets = boost::wave::cpplexer::re2clex::aq_create();

    q = s->eol_offsets;

    if (AQ_EMPTY(q))
        return;

    i = q->head;
    while (i != q->tail)
    {
        if (adjustment > q->queue[i])
            q->queue[i] = 0;
        else
            q->queue[i] -= adjustment;
        ++i;
        if (i == q->max_size)
            i = 0;
    }
    if (adjustment > q->queue[i])
        q->queue[i] = 0;
    else
        q->queue[i] -= adjustment;
}

template<typename Iterator>
int
count_backslash_newlines(boost::wave::cpplexer::re2clex::Scanner<Iterator> *s,
    boost::wave::cpplexer::re2clex::uchar *cursor)
{
    using namespace boost::wave::cpplexer::re2clex;

    std::size_t diff, offset;
    int skipped = 0;

    /* figure out how many backslash-newlines skipped over unknowingly. */
    diff = cursor - s->bot;
    offset = get_first_eol_offset(s);
    while (offset <= diff && offset != (unsigned int)-1)
    {
        skipped++;
        boost::wave::cpplexer::re2clex::aq_pop(s->eol_offsets);
        offset = get_first_eol_offset(s);
    }
    return skipped;
}

bool
is_backslash(
    boost::wave::cpplexer::re2clex::uchar *p,
    boost::wave::cpplexer::re2clex::uchar *end, int &len);

template<typename Iterator>
boost::wave::cpplexer::re2clex::uchar *
fill(boost::wave::cpplexer::re2clex::Scanner<Iterator> *s,
    boost::wave::cpplexer::re2clex::uchar *cursor)
{
    using namespace std;    // some systems have memcpy etc. in namespace std
    using namespace boost::wave::cpplexer::re2clex;

    if(!s->eof)
    {
        uchar* p;
        std::ptrdiff_t cnt = s->tok - s->bot;
        if(cnt)
        {
            memcpy(s->bot, s->tok, s->lim - s->tok);
            s->tok = s->bot;
            s->ptr -= cnt;
            cursor -= cnt;
            s->lim -= cnt;
            adjust_eol_offsets(s, cnt);
        }

        if((s->top - s->lim) < BOOST_WAVE_BSIZE)
        {
            uchar *buf = (uchar*) malloc(((s->lim - s->bot) + BOOST_WAVE_BSIZE)*sizeof(uchar));
            if (buf == 0)
            {
                using namespace std;      // some systems have printf in std
                if (0 != s->error_proc) {
                    (*s->error_proc)(s,
                        cpplexer::lexing_exception::unexpected_error,
                        "Out of memory!");
                }
                else
                    printf("Out of memory!\n");

                /* get the scanner to stop */
                *cursor = 0;
                return cursor;
            }

            memcpy(buf, s->tok, s->lim - s->tok);
            s->tok = buf;
            s->ptr = &buf[s->ptr - s->bot];
            cursor = &buf[cursor - s->bot];
            s->lim = &buf[s->lim - s->bot];
            s->top = &s->lim[BOOST_WAVE_BSIZE];
            free(s->bot);
            s->bot = buf;
        }

        cnt = std::distance(s->act, s->last);
        if (cnt > BOOST_WAVE_BSIZE)
            cnt = BOOST_WAVE_BSIZE;
        uchar * dst = s->lim;
        for (std::ptrdiff_t idx = 0; idx < cnt; ++idx)
        {
            *dst++ = *s->act++;
        }
        if (cnt != BOOST_WAVE_BSIZE) {
            s->eof = &s->lim[cnt];
            *(s->eof)++ = '\0';
        }

        /* backslash-newline erasing time */

        /* first scan for backslash-newline and erase them */
        for (p = s->lim; p < s->lim + cnt - 2; ++p)
        {
            int len = 0;
            if (is_backslash(p, s->lim + cnt, len))
            {
                if (*(p+len) == '\n')
                {
                    int offset = len + 1;
                    memmove(p, p + offset, s->lim + cnt - p - offset);
                    cnt -= offset;
                    --p;
                    aq_enqueue(s->eol_offsets, p - s->bot + 1);
                }
                else if (*(p+len) == '\r')
                {
                    if (*(p+len+1) == '\n')
                    {
                        int offset = len + 2;
                        memmove(p, p + offset, s->lim + cnt - p - offset);
                        cnt -= offset;
                        --p;
                    }
                    else
                    {
                        int offset = len + 1;
                        memmove(p, p + offset, s->lim + cnt - p - offset);
                        cnt -= offset;
                        --p;
                    }
                    aq_enqueue(s->eol_offsets, p - s->bot + 1);
                }
            }
        }

        /* FIXME: the following code should be fixed to recognize correctly the
                  trigraph backslash token */

        /* check to see if what we just read ends in a backslash */
        if (cnt >= 2)
        {
            uchar last = s->lim[cnt-1];
            uchar last2 = s->lim[cnt-2];
            /* check \ EOB */
            if (last == '\\')
            {
                int next = get_one_char(s);
                /* check for \ \n or \ \r or \ \r \n straddling the border */
                if (next == '\n')
                {
                    --cnt; /* chop the final \, we've already read the \n. */
                    boost::wave::cpplexer::re2clex::aq_enqueue(s->eol_offsets,
                        cnt + (s->lim - s->bot));
                }
                else if (next == '\r')
                {
                    int next2 = get_one_char(s);
                    if (next2 == '\n')
                    {
                        --cnt; /* skip the backslash */
                    }
                    else
                    {
                        /* rewind one, and skip one char */
                        rewind_stream(s, -1);
                        --cnt;
                    }
                    boost::wave::cpplexer::re2clex::aq_enqueue(s->eol_offsets,
                        cnt + (s->lim - s->bot));
                }
                else if (next != -1) /* -1 means end of file */
                {
                    /* next was something else, so rewind the stream */
                    rewind_stream(s, -1);
                }
            }
            /* check \ \r EOB */
            else if (last == '\r' && last2 == '\\')
            {
                int next = get_one_char(s);
                if (next == '\n')
                {
                    cnt -= 2; /* skip the \ \r */
                }
                else
                {
                    /* rewind one, and skip two chars */
                    rewind_stream(s, -1);
                    cnt -= 2;
                }
                boost::wave::cpplexer::re2clex::aq_enqueue(s->eol_offsets,
                    cnt + (s->lim - s->bot));
            }
            /* check \ \n EOB */
            else if (last == '\n' && last2 == '\\')
            {
                cnt -= 2;
                boost::wave::cpplexer::re2clex::aq_enqueue(s->eol_offsets,
                    cnt + (s->lim - s->bot));
            }
        }

        s->lim += cnt;
        if (s->eof) /* eof needs adjusting if we erased backslash-newlines */
        {
            s->eof = s->lim;
            *(s->eof)++ = '\0';
        }
    }
    return cursor;
}

///////////////////////////////////////////////////////////////////////////////
//  The scanner function to call whenever a new token is requested
template<typename Iterator>
BOOST_WAVE_DECL boost::wave::token_id scan(
    boost::wave::cpplexer::re2clex::Scanner<Iterator> *s)
{

    using namespace boost::wave::cpplexer::re2clex;

    uchar *cursor = s->tok = s->cur;

#include "idl.inc"


} /* end of scan */

///////////////////////////////////////////////////////////////////////////////
}   // namespace re2clex
}   // namespace idllexer
}   // namespace wave
}   // namespace boost

#undef RE2C_ASSERT

#endif // !defined(BOOST_IDL_RE_HPP_BD62775D_1659_4684_872C_03C02543C9A5_INCLUDED)