//
//Copyright (C) 2002-2005  3Dlabs Inc. Ltd.
//Copyright (C) 2013 LunarG, Inc.
//All rights reserved.
//
//Redistribution and use in source and binary forms, with or without
//modification, are permitted provided that the following conditions
//are met:
//
//    Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
//    Redistributions in binary form must reproduce the above
//    copyright notice, this list of conditions and the following
//    disclaimer in the documentation and/or other materials provided
//    with the distribution.
//
//    Neither the name of 3Dlabs Inc. Ltd. nor the names of its
//    contributors may be used to endorse or promote products derived
//    from this software without specific prior written permission.
//
//THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
//LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
//CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
//LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
//ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
//POSSIBILITY OF SUCH DAMAGE.
//
/****************************************************************************\
Copyright (c) 2002, NVIDIA Corporation.

NVIDIA Corporation("NVIDIA") supplies this software to you in
consideration of your agreement to the following terms, and your use,
installation, modification or redistribution of this NVIDIA software
constitutes acceptance of these terms.  If you do not agree with these
terms, please do not use, install, modify or redistribute this NVIDIA
software.

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"NVIDIA Software"), to use, reproduce, modify and redistribute the
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retain the copyright notice of NVIDIA, this notice and the following
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ITS USE AND OPERATION EITHER ALONE OR IN COMBINATION WITH OTHER
PRODUCTS.

IN NO EVENT SHALL NVIDIA BE LIABLE FOR ANY SPECIAL, INDIRECT,
INCIDENTAL, EXEMPLARY, CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, LOST PROFITS; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) OR ARISING IN ANY WAY
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\****************************************************************************/
//
// scanner.c
//

#define _CRT_SECURE_NO_WARNINGS

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "PpContext.h"
#include "PpTokens.h"

static int eof_scan(TPpContext*, TPpContext::InputSrc*, TPpToken*)
{
    return EOF;
} // eof_scan

static void noop(TPpContext*, TPpContext::InputSrc *in, int ch, TPpToken * yylvalpp) {}
static TPpContext::InputSrc eof_inputsrc = { 0, &eof_scan, &eof_scan, &noop };

int TPpContext::InitScanner(TPpContext *cpp)
{
    // Add various atoms needed by the CPP line scanner:
    if (!InitCPP())
        return 0;

    mostRecentToken = 0;
    currentInput = &eof_inputsrc;
    previous_token = '\n';
    notAVersionToken = false;

    return 1;
} // InitScanner

int TPpContext::FreeScanner(void)
{
    return (FreeCPP());
}

/*
* str_getch()
* takes care of reading from multiple strings.
* returns the next-char from the input stream.
* returns EOF when the complete shader is parsed.
*/
int TPpContext::str_getch(TPpContext* pp, StringInputSrc *in)
{
    for(;;) {
        if (*in->p) {
            if (*in->p == '\n') {
                in->base.line++;
                ++pp->parseContext.currentLoc.line;
            }
            return *in->p++;
        }
        if (pp->currentString < 0) {
            // we only parsed the built-in pre-amble; start with clean slate for user code
            pp->notAVersionToken = false;
        }
        if (++(pp->currentString) < pp->numStrings) {
            free(in);
            pp->parseContext.currentLoc.string = pp->currentString;
            pp->parseContext.currentLoc.line = 1;
            pp->ScanFromString(pp->strings[pp->currentString]);
            in=(StringInputSrc*)pp->currentInput;
            continue;             
        } else {
            pp->currentInput = in->base.prev;
            pp->currentString = 0;
            free(in);
            return EOF;
        }  
    }
} // str_getch

void TPpContext::str_ungetch(TPpContext* pp, StringInputSrc *in, int ch, TPpToken *type)
{
    if (in->p[-1] == ch)in->p--;
    else {
        *(in->p)='\0'; //this would take care of shifting to the previous string.
        pp->currentString--;
        pp->parseContext.currentLoc.string = pp->currentString;
    }  
    if (ch == '\n') {
        in->base.line--;
        --pp->parseContext.currentLoc.line;
    }
} // str_ungetch

int TPpContext::ScanFromString(char *s)
{

    StringInputSrc *in = (StringInputSrc *)malloc(sizeof(StringInputSrc));
    memset(in, 0, sizeof(StringInputSrc));
    in->p = s;
    in->base.line = 1;
    in->base.scan = byte_scan;
    in->base.getch = (int (*)(TPpContext*, InputSrc *, TPpToken *))str_getch;
    in->base.ungetch = (void (*)(TPpContext*, InputSrc *, int, TPpToken *))str_ungetch;
    in->base.prev = currentInput;
    currentInput = &in->base;

    return 1;
}


///////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////// Floating point constants: /////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////

/*
* lFloatConst() - Scan a single- or double-precision floating point constant.  Assumes that the scanner
*         has seen at least one digit, followed by either a decimal '.' or the
*         letter 'e'.
*/

int TPpContext::lFloatConst(char *str, int len, int ch, TPpToken * yylvalpp)
{
    int HasDecimal, declen, exp, ExpSign;
    int str_len;
    int isDouble = 0;

    HasDecimal = 0;
    declen = 0;
    exp = 0;

    str_len=len;
    if (ch == '.') {
        str[len++]=ch;
        HasDecimal = 1;
        ch = currentInput->getch(this, currentInput, yylvalpp);
        while (ch >= '0' && ch <= '9') {
            if (len < TPpToken::maxTokenLength) {
                declen++;
                if (len > 0 || ch != '0') {
                    str[len] = ch;
                    len++;str_len++;
                }
                ch = currentInput->getch(this, currentInput, yylvalpp);
            } else {
                parseContext.error(yylvalpp->loc,"float literal too long", "", "");
                len = 1,str_len=1;
            }
        }
    }

    // Exponent:

    if (ch == 'e' || ch == 'E') {
        if (len >= TPpToken::maxTokenLength) {
            parseContext.error(yylvalpp->loc,"float literal too long", "", "");
            len = 1,str_len=1;
        } else {
            ExpSign = 1;
            str[len++]=ch;
            ch = currentInput->getch(this, currentInput, yylvalpp);
            if (ch == '+') {
                str[len++]=ch;  
                ch = currentInput->getch(this, currentInput, yylvalpp);
            } else if (ch == '-') {
                ExpSign = -1;
                str[len++]=ch;
                ch = currentInput->getch(this, currentInput, yylvalpp);
            }
            if (ch >= '0' && ch <= '9') {
                while (ch >= '0' && ch <= '9') {
                    if (len < TPpToken::maxTokenLength) {
                        exp = exp*10 + ch - '0';
                        str[len++]=ch;
                        ch = currentInput->getch(this, currentInput, yylvalpp);
                    } else {
                        parseContext.error(yylvalpp->loc,"float literal too long", "", "");
                        len = 1,str_len=1;
                    }
                }
            } else {
                parseContext.error(yylvalpp->loc,"bad character in float exponent", "", "");
            }
            exp *= ExpSign;
        }
    }

    if (len == 0) {
        yylvalpp->dval = 0.0;
        strcpy(str, "0.0");
    } else {
        if (ch == 'l' || ch == 'L') {
            int ch2 = currentInput->getch(this, currentInput, yylvalpp);
            if (ch2 != 'f' && ch2 != 'F') {
                currentInput->ungetch(this, currentInput, ch2, yylvalpp);
                currentInput->ungetch(this, currentInput, ch, yylvalpp);
            } else {
                if (len < TPpToken::maxTokenLength) {
                    str[len++] = ch;
                    str[len++] = ch2;
                    isDouble = 1;
                } else {
                    parseContext.error(yylvalpp->loc,"float literal too long", "", "");
                    len = 1,str_len=1;
                }
            }
        } else if (ch == 'f' || ch == 'F') {
            if (len < TPpToken::maxTokenLength)
                str[len++] = ch;
            else {
                parseContext.error(yylvalpp->loc,"float literal too long", "", "");
                len = 1,str_len=1;
            }
        } else 
            currentInput->ungetch(this, currentInput, ch, yylvalpp);

        str[len]='\0';      

        yylvalpp->dval = strtod(str, 0);
    }
    // Suffix:
    strcpy(yylvalpp->name, str);

    if (isDouble)
        return CPP_DOUBLECONSTANT;
    else
        return CPP_FLOATCONSTANT;
} // lFloatConst

///////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////// Normal Scanner //////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////

int TPpContext::byte_scan(TPpContext* pp, InputSrc *in, TPpToken * yylvalpp)
{
    char tokenText[TPpToken::maxTokenLength + 1];
    int AlreadyComplained = 0;
    int len, ch, ii;
    unsigned ival = 0;

    for (;;) {
        yylvalpp->ival = 0;
        ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);

        while (ch == ' ' || ch == '\t' || ch == '\r') {
            yylvalpp->ival = 1;
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
        }

        yylvalpp->loc = pp->parseContext.currentLoc;
        len = 0;
        switch (ch) {
        default:
            return ch; // Single character token
        case EOF:
            return EOF;
        case 'A': case 'B': case 'C': case 'D': case 'E':
        case 'F': case 'G': case 'H': case 'I': case 'J':
        case 'K': case 'L': case 'M': case 'N': case 'O':
        case 'P': case 'Q': case 'R': case 'S': case 'T':
        case 'U': case 'V': case 'W': case 'X': case 'Y':
        case 'Z': case '_':
        case 'a': case 'b': case 'c': case 'd': case 'e':
        case 'f': case 'g': case 'h': case 'i': case 'j':
        case 'k': case 'l': case 'm': case 'n': case 'o':
        case 'p': case 'q': case 'r': case 's': case 't':
        case 'u': case 'v': case 'w': case 'x': case 'y':
        case 'z':            
            do {
                if (ch == '\\') {
                    // escaped character
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                    if (ch == '\r' || ch == '\n') {
                        int nextch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                        if (ch == '\r' && nextch == '\n')
                            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                        else
                            ch = nextch;
                    } else
                        pp->parseContext.error(yylvalpp->loc,"can only escape newlines", "\\", "");
                } else if (len < TPpToken::maxTokenLength) {
                    tokenText[len++] = ch;
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);					
                } else {
                    if (! AlreadyComplained) {
                        pp->parseContext.error(yylvalpp->loc,"name too long", "", "");
                        AlreadyComplained = 1;
                    }
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);					
                }
            } while ((ch >= 'a' && ch <= 'z') ||
                (ch >= 'A' && ch <= 'Z') ||
                (ch >= '0' && ch <= '9') ||
                ch == '_' ||
                ch == '\\');

            tokenText[len] = '\0';
            pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
            yylvalpp->atom = pp->LookUpAddString(&pp->atomTable, tokenText);

            return CPP_IDENTIFIER;
        case '0':
            yylvalpp->name[len++] = ch;
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == 'x' || ch == 'X') {
                int uint = 0;
                yylvalpp->name[len++] = ch;
                ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                if ((ch >= '0' && ch <= '9') ||
                    (ch >= 'A' && ch <= 'F') ||
                    (ch >= 'a' && ch <= 'f'))
                {
                    ival = 0;
                    do {
                        if (ival <= 0x0fffffff) {
                            yylvalpp->name[len++] = ch;
                            if (ch >= '0' && ch <= '9') {
                                ii = ch - '0';
                            } else if (ch >= 'A' && ch <= 'F') {
                                ii = ch - 'A' + 10;
                            } else if (ch >= 'a' && ch <= 'f') {
                                ii = ch - 'a' + 10;
                            } else
                                pp->parseContext.error(yylvalpp->loc,"bad digit in hexidecimal literal", "", "");
                            ival = (ival << 4) | ii;
                        } else {
                            if (! AlreadyComplained) {
                                pp->parseContext.error(yylvalpp->loc,"hexidecimal literal too big literal", "", "");
                                AlreadyComplained = 1;
                            }
                            ival = 0xffffffff;
                        }
                        ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                    } while ((ch >= '0' && ch <= '9') ||
                        (ch >= 'A' && ch <= 'F') ||
                        (ch >= 'a' && ch <= 'f'));
                } else {
                    pp->parseContext.error(yylvalpp->loc,"bad digit in hexidecimal literal", "", "");
                }
                if (ch == 'u' || ch == 'U') {
                    if (len < TPpToken::maxTokenLength)
                        yylvalpp->name[len++] = ch;
                    uint = 1;
                } else
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                yylvalpp->name[len] = '\0';
                yylvalpp->ival = (int)ival;

                if (uint)
                    return CPP_UINTCONSTANT;
                else
                    return CPP_INTCONSTANT;
            } else if (ch >= '0' && ch <= '7') { // octal integer constants
                int uint = 0;
                ival = 0;
                do {
                    if (ival <= 0x1fffffff) {
                        yylvalpp->name[len++] = ch;
                        ii = ch - '0';
                        ival = (ival << 3) | ii;
                    } else {
                        if (!AlreadyComplained) {
                            pp->parseContext.error(yylvalpp->loc,"octal literal too big", "", "");
                            AlreadyComplained = 1;
                        }
                        ival = 0xffffffff;
                    }
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                } while (ch >= '0' && ch <= '7');
                if (ch == '.' || ch == 'e' || ch == 'f' || ch == 'h' || ch == 'x'|| ch == 'E' || ch == 'F' || ch == 'l' || ch == 'L') 
                    return pp->lFloatConst(yylvalpp->name, len, ch, yylvalpp);
                else  if (ch == 'u' || ch == 'U') {
                    if (len < TPpToken::maxTokenLength)
                        yylvalpp->name[len++] = ch;
                    uint = 1;
                } else
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                yylvalpp->name[len] = '\0';
                yylvalpp->ival = (int)ival;

                if (uint)
                    return CPP_UINTCONSTANT;
                else
                    return CPP_INTCONSTANT;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                ch = '0';
            }
            // Fall through...
        case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
            do {
                if (len < TPpToken::maxTokenLength) {
                    if (len > 0 || ch != '0') {
                        yylvalpp->name[len] = ch;
                        len++;
                    }
                } else {
                    if (! AlreadyComplained) {
                        pp->parseContext.error(yylvalpp->loc,"numeric literal too long", "", "");
                        AlreadyComplained = 1;
                    }
                }
                ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            } while (ch >= '0' && ch <= '9');
            if (ch == '.' || ch == 'e' || ch == 'f' || ch == 'h' || ch == 'x'|| ch == 'E' || ch == 'F' || ch == 'l' || ch == 'L') {
                return pp->lFloatConst(yylvalpp->name, len, ch, yylvalpp);
            } else {
                // Finish handling signed and unsigned integers
                int numericLen = len;
                int uint = 0;
                if (ch == 'u' || ch == 'U') {
                    if (len < TPpToken::maxTokenLength)
                        yylvalpp->name[len++] = ch;
                    uint = 1;
                } else
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);

                yylvalpp->name[len] = '\0';				
                ival = 0;
                for (ii = 0; ii < numericLen; ii++) {
                    ch = yylvalpp->name[ii] - '0';
                    if ((ival > 429496729) || (ival == 429496729 && ch >= 6)) {
                        pp->parseContext.error(yylvalpp->loc,"numeric literal too big", "", "");
                        ival = -1;
                        break;
                    } else
                        ival = ival * 10 + ch;
                }
                yylvalpp->ival = (int)ival;

                if (uint)
                    return CPP_UINTCONSTANT;
                else
                    return CPP_INTCONSTANT;
            }
            break;
        case '-':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '-') {
                return CPP_DEC_OP;
            } else if (ch == '=') {
                return CPP_SUB_ASSIGN;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '-';
            }
        case '+':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '+') {
                return CPP_INC_OP;
            } else if (ch == '=') {
                return CPP_ADD_ASSIGN;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '+';
            }
        case '*':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '=') {
                return CPP_MUL_ASSIGN;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '*';
            }
        case '%':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '=') {
                return CPP_MOD_ASSIGN;
            } else if (ch == '>'){
                return CPP_RIGHT_BRACE;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '%';
            }
        case ':':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '>') {
                return CPP_RIGHT_BRACKET;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return ':';
            }
        case '^':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '^') {
                return CPP_XOR_OP;
            } else {
                if (ch == '=')
                    return CPP_XOR_ASSIGN;
                else{
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                    return '^';
                }
            }

        case '=':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '=') {
                return CPP_EQ_OP;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '=';
            }
        case '!':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '=') {
                return CPP_NE_OP;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '!';
            }
        case '|':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '|') {
                return CPP_OR_OP;
            } else {
                if (ch == '=')
                    return CPP_OR_ASSIGN;
                else{
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                    return '|';
                }
            }
        case '&':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '&') {
                return CPP_AND_OP;
            } else {
                if (ch == '=')
                    return CPP_AND_ASSIGN;
                else{
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                    return '&';
                }
            }
        case '<':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '<') {
                ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                if (ch == '=')
                    return CPP_LEFT_ASSIGN;
                else{
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                    return CPP_LEFT_OP;
                }
            } else {
                if (ch == '=') {
                    return CPP_LE_OP;
                } else {
                    if (ch == '%')
                        return CPP_LEFT_BRACE;
                    else if (ch == ':')
                        return CPP_LEFT_BRACKET;
                    else{
                        pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                        return '<';
                    }
                }
            }
        case '>':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '>') {
                ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                if (ch == '=')
                    return CPP_RIGHT_ASSIGN;
                else{
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                    return CPP_RIGHT_OP;
                }
            } else {
                if (ch == '=') {
                    return CPP_GE_OP;
                } else {
                    pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                    return '>';
                }
            }
        case '.':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch >= '0' && ch <= '9') {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return pp->lFloatConst(yylvalpp->name, 0, '.', yylvalpp);
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '.';
            }
        case '/':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            if (ch == '/') {
                do {
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                    if (ch == '\\') {
                        // allow an escaped newline, otherwise escapes in comments are meaningless
                        ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                        if (ch == '\r' || ch == '\n') {
                            int nextch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                            if (ch == '\r' && nextch == '\n')
                                ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                            else
                                ch = nextch;
                        }
                    }
                } while (ch != '\n' && ch != EOF);
                if (ch == EOF)
                    return EOF;
                return '\n';
            } else if (ch == '*') {
                int nlcount = 0;
                ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                do {
                    while (ch != '*') {
                        if (ch == '\n')
                            nlcount++;
                        if (ch == EOF) {
                            pp->parseContext.error(yylvalpp->loc,"EOF in comment", "comment", "");

                            return EOF;
                        }
                        ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                    }
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                    if (ch == EOF) {
                        pp->parseContext.error(yylvalpp->loc,"EOF in comment", "comment", "");

                        return EOF;
                    }
                } while (ch != '/');
                if (nlcount)
                    return '\n';
                // Go try it again...
            } else if (ch == '=') {
                return CPP_DIV_ASSIGN;
            } else {
                pp->currentInput->ungetch(pp, pp->currentInput, ch, yylvalpp);
                return '/';
            }
            break;
        case '"':
            ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
            while (ch != '"' && ch != '\n' && ch != EOF) {
                if (ch == '\\') {
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                    if (ch == '\n' || ch == EOF) {
                        break;
                    }
                }
                if (len < TPpToken::maxTokenLength) {
                    tokenText[len] = ch;
                    len++;
                    ch = pp->currentInput->getch(pp, pp->currentInput, yylvalpp);
                } else
                    break;
            };
            tokenText[len] = '\0';
            if (ch == '"') {
                yylvalpp->atom = pp->LookUpAddString(&pp->atomTable, tokenText);
                return CPP_STRCONSTANT;
            } else {
                pp->parseContext.error(yylvalpp->loc,"end of line in string", "string", "");
                return CPP_ERROR_SY;
            }
        }
    }
} // byte_scan

const char* TPpContext::tokenize(TPpToken* yylvalpp)
{    
    int token = '\n';

    for(;;) {

        char* tokenString = 0;
        token = currentInput->scan(this, currentInput, yylvalpp);
        yylvalpp->ppToken = token;
        if (check_EOF(token))
            return 0;
        if (token == '#') {
            if (previous_token == '\n' || previous_token == 0) {
                token = readCPPline(yylvalpp);
                if (check_EOF(token))
                    return 0;
                continue;
            } else {
                parseContext.error(yylvalpp->loc,"preprocessor directive cannot be preceded by another token", "#", "");
                return 0;
            }
        }
        previous_token = token;

        if (token == '\n')
            continue;

        notAVersionToken = true;

        // expand macros
        if (token == CPP_IDENTIFIER && MacroExpand(yylvalpp->atom, yylvalpp, 0) == 1)
            continue;

        if (token == CPP_IDENTIFIER)
            tokenString = GetStringOfAtom(&atomTable, yylvalpp->atom);
        else if (token == CPP_INTCONSTANT || token == CPP_UINTCONSTANT ||
                 token == CPP_FLOATCONSTANT || token == CPP_DOUBLECONSTANT)
            tokenString = yylvalpp->name;
        else
            tokenString = GetStringOfAtom(&atomTable, token);

        if (tokenString) {
            if (tokenString[0] != 0)
                parseContext.tokensBeforeEOF = 1;

            return tokenString;
        }
    }

    return 0;
} // PpTokenize

//Checks if the token just read is EOF or not.
int TPpContext::check_EOF(int token)
{
    if (token == EOF) {
        if (ifdepth > 0)
            parseContext.error(parseContext.currentLoc, "missing #endif", "#if", "");
        return 1;
    }
    return 0;
}

///////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////// End of scanner.c //////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////