scanner.c

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// scanner.c
//

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

#if 0
#include <ieeefp.h>
#else
#define isinff(x) (((*(long *)&(x) & 0x7f800000L)==0x7f800000L) && \
                   ((*(long *)&(x) & 0x007fffffL)==0000000000L))
#endif

#include "slglobals.h"

const char *Build_Date = __DATE__;
const char *Build_Time = __TIME__;

typedef struct FileInputSrc {
    InputSrc            base;
    FILE                *fd;
    char                save_cnt;
    char                save[3];
} FileInputSrc;

typedef struct StringInputSrc {
    InputSrc base;
    char *p;
} StringInputSrc;

static int eof_scan(InputSrc *is)
{
    return EOF;
} // eof_scan

static void noop(InputSrc *in, int ch) {}

static InputSrc eof_inputsrc = { 0, &eof_scan, &eof_scan, &noop };

static int byte_scan(InputSrc *);
static int nextchar(FileInputSrc *);
static void ungetchar(FileInputSrc *, int);

#define EOL_SY '\n'

#if defined(_WIN32)
#define DBG_BREAKPOINT() __asm int 3
#else
#define DBG_BREAKPOINT()
#endif

#if defined(_WIN32)
__int64 RDTSC ( void ) {

    __int64 v;

    __asm __emit 0x0f
    __asm __emit 0x31
    __asm mov dword ptr v, eax
    __asm mov dword ptr v+4, edx

    return v;
}
#endif

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

    Cg->mostRecentToken = 0;
    Cg->tokenLoc = &Cg->ltokenLoc;

    Cg->ltokenLoc.file = 0;
    Cg->ltokenLoc.line = 0;
    Cg->errorCount = 0;
    Cg->warningCount = 0;
    Cg->lineCount = 0;
    Cg->AllowSemanticParseErrors = 0;

    Cg->currentInput = &eof_inputsrc;

    return 1;
} // InitScanner

int SetInputFile(const char *fname)
{
    FileInputSrc *in = malloc(sizeof(FileInputSrc));
    memset(in, 0, sizeof(FileInputSrc));
    if (fname) {
        if (!Cg->options.Quiet)
            printf("%s\n", fname);
        in->base.name = LookUpAddString(atable, fname);
        in->fd = fopen(fname, "r");
        if (!in->fd) {
            printf(OPENSL_TAG ": cannot open input file \"%s\"\n", fname);
            free(in);
            return 0;
        }
    } else {
        in->fd = stdin;
        in->base.name = LookUpAddString(atable, "<stdin>");
    }
    in->base.line = 1;
    in->base.scan = byte_scan;
    in->base.getch = (int (*)(InputSrc *)) nextchar;
    in->base.ungetch = (void (*)(InputSrc *, int)) ungetchar;
    in->base.prev = Cg->currentInput;
    Cg->currentInput = &in->base;
#if 0 && !defined(_DEBUG)
    if (Cg->options.TraceScanner) {
        __int64 s,e;
        s = RDTSC();
        while (Cg->currentInput->scan(Cg->currentInput) > 0)
            /* empty statement */ ;
        e = RDTSC();
        printf("%d cycles\n", (int)(e-s));
        return 0;
    }
#endif
    return 1;
} // SetInputFile

static int str_getch(StringInputSrc *in)
{
    if (*in->p)
        return *in->p++;
    Cg->currentInput = in->base.prev;
    free(in);
    return ' ';
} // str_getch

static void str_ungetch(StringInputSrc *in, int ch) {
    if (in->p[-1] == ch) in->p--;
} // str_ungetch

int ScanFromString(char *s)
{
    StringInputSrc *in = malloc(sizeof(StringInputSrc));
    memset(in, 0, sizeof(StringInputSrc));
    in->p = s;
    in->base.line = 1;
    in->base.scan = byte_scan;
    in->base.getch = (int (*)(InputSrc *))str_getch;
    in->base.ungetch = (void (*)(InputSrc *, int))str_ungetch;
    in->base.prev = Cg->currentInput;
    Cg->currentInput = &in->base;
    return 1;
} // ScanFromString;

int FreeScanner(CgStruct *Cg)
{
    FinalCPP();
    if (Cg->warningCount || Cg->errorCount || !Cg->options.Quiet) {
        fprintf(Cg->options.listfd, "%d lines", Cg->lineCount);
        if (Cg->warningCount)
            fprintf(Cg->options.listfd, ", %d warnings", Cg->warningCount);
        fprintf(Cg->options.listfd, ", %d errors.\n", Cg->errorCount);
    }
    return Cg->errorCount;
} // FreeScanner

int GetErrorCount(void)
{
    return Cg->errorCount;
} // GetErrorCount

/*
 * bumpErrorCount() - Useful for setting breakpoints when debugging.
 *
 */

void bumpErrorCount(void)
{
    Cg->errorCount++;
    if (Cg->options.TrapOnError) {
        DBG_BREAKPOINT();
    }
} // bumbErrorCount

/*
 * bumpWarningCount() - Useful for setting breakpoints when debugging.
 *
 */

void bumpWarningCount(void)
{
    Cg->warningCount++;
    if (Cg->options.TrapOnError) {
        DBG_BREAKPOINT();
    }
} // bumpWarningCount

// Called by yyparse on an error:

void yyerror(const char *s)
{
    if (!Cg->options.ErrorMode) {
        if (Cg->ltokenLoc.file) {
            fprintf(Cg->options.listfd, "%s(%d) : error C0000: ",
                    GetAtomString(atable, Cg->ltokenLoc.file), Cg->ltokenLoc.line);
        } else {
            fprintf(Cg->options.listfd, "(%d) : error C0000: ", Cg->currentInput->line);
        }
        fprintf(Cg->options.listfd, "%s at token \"%s\"\n", s,
                GetAtomString(atable, Cg->mostRecentToken));
        Cg->AllowSemanticParseErrors = 1;
    }
    bumpErrorCount();
} // yyerror

/*
 * SemanticParseError() - Compiler generated semantic error inside an error rule.
 *
 */

void SemanticParseError(SourceLoc *loc, int num, const char *mess, ...)
{
    va_list args;

    if (Cg->AllowSemanticParseErrors) {
        if (!Cg->options.ErrorMode) {
            if (loc->file) {
                fprintf(Cg->options.listfd, "%s(%d) : error C%04d: ",
                        GetAtomString(atable, loc->file), loc->line, num);
            } else {
                fprintf(Cg->options.listfd, "(%d) : error C%04d: ", loc->line, num);
            }
            va_start(args, mess);
            vfprintf(Cg->options.listfd, mess, args);
            va_end(args);
            fprintf(Cg->options.listfd, "\n");
            bumpErrorCount();
        } else {
            MarkErrorPosHit(loc);
        }

        Cg->AllowSemanticParseErrors = 0;
    }
} // SemanticParseError

/*
 * SemanticError() - Compiler generated semantic error.
 *
 */

void SemanticError(SourceLoc *loc, int num, const char *mess, ...)
{
    va_list args;

    if (!Cg->options.ErrorMode) {
        if (loc->file) {
            fprintf(Cg->options.listfd, "%s(%d) : error C%04d: ",
                    GetAtomString(atable, loc->file), loc->line, num);
        } else {
            fprintf(Cg->options.listfd, "(%d) : error C%04d: ", loc->line, num);
        }
        va_start(args, mess);
        vfprintf(Cg->options.listfd, mess, args);
        va_end(args);
        fprintf(Cg->options.listfd, "\n");
        bumpErrorCount();
    } else {
        MarkErrorPosHit(loc);
    }
} // SemanticError

/*
 * InternalError() - Internal compiler error.
 *
 */

void InternalError(SourceLoc *loc, int num, const char *mess, ...)
{
    va_list args;

    if (loc->file) {
        fprintf(Cg->options.listfd, "%s(%d) : error C%04d: ",
                GetAtomString(atable, loc->file), loc->line, num);
    } else {
        fprintf(Cg->options.listfd, "(%d) : error C%04d: ", loc->line, num);
    }
    va_start(args, mess);
    vfprintf(Cg->options.listfd, mess, args);
    va_end(args);
    fprintf(Cg->options.listfd, "\n");
    bumpErrorCount();
} // InternalError

/*
 * FatalError() - Fatal internal compiler error.
 *
 */

void FatalError(const char *mess, ...)
{
    va_list args;

    fprintf(Cg->options.listfd, "(%d) : fatal error C9999: ", Cg->lineCount);
    va_start(args, mess);
    vfprintf(Cg->options.listfd, mess, args);
    va_end(args);
    fprintf(Cg->options.listfd, "\n");
    bumpErrorCount();
    CloseOutputFiles("Compilation terminated due to fatal error");
    exit(9999);
} // InternalError

/*
 * SemanticWarning() - Compiler generated semantic warning.
 *
 */

void SemanticWarning(SourceLoc *loc, int num, const char *mess, ...)
{
    va_list args;

    if (!Cg->options.NoWarnings) {
        if (!Cg->options.ErrorMode) {
            if (loc->file) {
                fprintf(Cg->options.listfd, "%s(%d) : warning C%04d: ",
                        GetAtomString(atable, loc->file), loc->line, num);
            } else {
                fprintf(Cg->options.listfd, "(%d) : warning C%04d: ", loc->line, num);
            }
            va_start(args, mess);
            vfprintf(Cg->options.listfd, mess, args);
            va_end(args);
            fprintf(Cg->options.listfd, "\n");
        }
        bumpWarningCount();
    }
} // SemanticWarning

/*
 * InformationalNotice() - Print a message from the compiler.
 *
 */

void InformationalNotice(SourceLoc *loc, int num, const char *mess, ...)
{
    va_list args;

    if (!Cg->options.NoWarnings) {
        if (!Cg->options.ErrorMode) {
            if (loc->file) {
                fprintf(Cg->options.listfd, "%s(%d) : notice C%04d: ",
                        GetAtomString(atable, loc->file), loc->line, num);
            } else {
                fprintf(Cg->options.listfd, "(%d) : notice C%04d: ", loc->line, num);
            }
            va_start(args, mess);
            vfprintf(Cg->options.listfd, mess, args);
            va_end(args);
            fprintf(Cg->options.listfd, "\n");
        }
    }
} // InformationalNotice

// The scanner:

static int nextchar(FileInputSrc *in)
{
    int ch;

    if (in->save_cnt) {
        ch = in->save[--in->save_cnt];
    } else {
        ch = getc(in->fd);
        if (ch == EOF) {
            Cg->currentInput = in->base.prev;
            fclose(in->fd);
            free(in);
            return '\n';
        }
    }
    if (ch == '\n') {
        Cg->lineCount++;
        in->base.line++;
    }

    return ch;
} // nextchar

static void ungetchar(FileInputSrc *in, int ch)
{
    if (&in->base == Cg->currentInput) {
        if (in->save_cnt < sizeof(in->save))
            in->save[in->save_cnt++] = ch;
        if (ch == '\n') {
            in->base.line--;
            Cg->lineCount--;
        }
    }

} // ungetchar

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

/*
 * lBuildFloatValue() - Quick and dirty conversion to floating point.  Since all
 *         we need is single precision this should be quite precise.
 */

static float lBuildFloatValue(const char *str, int len, int exp)
{
    double val, expval, ten;
    int ii, llen, absexp;
    float rv;

    val = 0.0;
    llen = len;
    for (ii = 0; ii < len; ii++)
        val = val*10.0 + (str[ii] - '0');
    if (exp != 0) {
        absexp = exp > 0 ? exp : -exp;
        expval = 1.0f;
        ten = 10.0;
        while (absexp) {
            if (absexp & 1)
                expval *= ten;
            ten *= ten;
            absexp >>= 1;
        }
        if (exp >= 0) {
            val *= expval;
        } else {
            val /= expval;
        }
    }
    rv = (float)val;
    if (isinff(rv)) {
        SemanticError(Cg->tokenLoc, ERROR___FP_CONST_OVERFLOW);
    }
    return rv;
} // lBuildFloatValue

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

static int lFloatConst(char *str, int len, int ch)
{
    int HasDecimal, declen, exp, ExpSign;
    float lval;

    HasDecimal = 0;
    declen = 0;
    exp = 0;
    if (ch == '.') {
        HasDecimal = 1;
        ch = Cg->currentInput->getch(Cg->currentInput);
        while (ch >= '0' && ch <= '9') {
            if (len < MAX_SYMBOL_NAME_LEN) {
                declen++;
                if (len > 0 || ch != '0') {
                    str[len] = ch;
                    len++;
                }
                ch = Cg->currentInput->getch(Cg->currentInput);
            } else {
                SemanticError(Cg->tokenLoc, ERROR___FP_CONST_TOO_LONG);
                len = 1;
            }
        }
    }

    // Exponent:

    if (ch == 'e' || ch == 'E') {
        ExpSign = 1;
        ch = Cg->currentInput->getch(Cg->currentInput);
        if (ch == '+') {
            ch = Cg->currentInput->getch(Cg->currentInput);
        } else if (ch == '-') {
            ExpSign = -1;
            ch = Cg->currentInput->getch(Cg->currentInput);
        }
        if (ch >= '0' && ch <= '9') {
            while (ch >= '0' && ch <= '9') {
                exp = exp*10 + ch - '0';
                ch = Cg->currentInput->getch(Cg->currentInput);
            }
        } else {
            SemanticError(Cg->tokenLoc, ERROR___ERROR_IN_EXPONENT);
        }
        exp *= ExpSign;
    }

    if (len == 0) {
        lval = 0.0f;
    } else {
        lval = lBuildFloatValue(str, len, exp - declen);
    }

    // Suffix:

    yylval.sc_fval = lval;
    if (ch == 'h') {
        return FLOATHCONST_SY;
    } else {
        if (ch == 'x') {
            return FLOATXCONST_SY;
        } else {
            if (ch == 'f') {
                return FLOATCONST_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return CFLOATCONST_SY;
            }
        }
    }
} // lFloatConst

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

static int byte_scan(InputSrc *in)
{
    char symbol_name[MAX_SYMBOL_NAME_LEN + 1];
    char string_val[MAX_STRING_LEN + 1];
    int AlreadyComplained;
    int len, ch, ii, ival;

    for (;;) {
        yylval.sc_int = 0;
        ch = Cg->currentInput->getch(Cg->currentInput);
        while (ch == ' ' || ch == '\t' || ch == '\r') {
            yylval.sc_int = 1;
            ch = Cg->currentInput->getch(Cg->currentInput);
        }
        Cg->ltokenLoc.file = Cg->currentInput->name;
        Cg->ltokenLoc.line = Cg->currentInput->line;
        switch (ch) {
        default:
            return ch; // Single character token
        case EOF:
            return 0;
        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':
            len = 0;
            do {
                if (len < MAX_SYMBOL_NAME_LEN) {
                    symbol_name[len] = ch;
                    len++;
                    ch = Cg->currentInput->getch(Cg->currentInput);
                }
            } while ((ch >= 'a' && ch <= 'z') ||
                     (ch >= 'A' && ch <= 'Z') ||
                     (ch >= '0' && ch <= '9') ||
                     ch == '_');
            symbol_name[len] = '\0';
            Cg->currentInput->ungetch(Cg->currentInput, ch);
            yylval.sc_ident = LookUpAddString(atable, symbol_name);
            return IDENT_SY;
            break;
        case '0':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == 'x' || ch == 'X') {
                ch = Cg->currentInput->getch(Cg->currentInput);
                if ((ch >= '0' && ch <= '9') ||
                    (ch >= 'A' && ch <= 'F') ||
                    (ch >= 'a' && ch <= 'f'))
                {
                    AlreadyComplained = 0;
                    ival = 0;
                    do {
                        if (ival <= 0x0fffffff) {
                            if (ch >= '0' && ch <= '9') {
                                ii = ch - '0';
                            } else if (ch >= 'A' && ch <= 'F') {
                                ii = ch - 'A' + 10;
                            } else {
                                ii = ch - 'a' + 10;
                            }
                            ival = (ival << 4) | ii;
                        } else {
                            if (!AlreadyComplained)
                                SemanticError(Cg->tokenLoc, ERROR___HEX_CONST_OVERFLOW);
                            AlreadyComplained = 1;
                        }
                        ch = Cg->currentInput->getch(Cg->currentInput);
                    } while ((ch >= '0' && ch <= '9') ||
                             (ch >= 'A' && ch <= 'F') ||
                             (ch >= 'a' && ch <= 'f'));
                } else {
                    SemanticError(Cg->tokenLoc, ERROR___ERROR_IN_HEX_CONSTANT);
                }
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                yylval.sc_int = ival;
                return INTCONST_SY;
            } else if (ch >= '0' && ch <= '7') { // octal integer constants
                AlreadyComplained = 0;
                ival = 0;
                do {
                    if (ival <= 0x1fffffff) {
                        ii = ch - '0';
                        ival = (ival << 3) | ii;
                    } else {
                        if (!AlreadyComplained)
                            SemanticError(Cg->tokenLoc, ERROR___OCT_CONST_OVERFLOW);
                        AlreadyComplained = 1;
                    }
                    ch = Cg->currentInput->getch(Cg->currentInput);
                } while (ch >= '0' && ch <= '7');
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                yylval.sc_int = ival;
                return INTCONST_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                ch = '0';
            }
            // Fall through...
        case '1': case '2': case '3': case '4':
        case '5': case '6': case '7': case '8': case '9':
            len = 0;
            do {
                if (len < MAX_SYMBOL_NAME_LEN) {
                    if (len > 0 || ch != '0') {
                        symbol_name[len] = ch;
                        len++;
                    }
                    ch = Cg->currentInput->getch(Cg->currentInput);
                }
            } while (ch >= '0' && ch <= '9');
            if (ch == '.' || ch == 'e' || ch == 'f' || ch == 'h' || ch == 'x') {
                return lFloatConst(symbol_name, len, ch);
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                ival = 0;
                AlreadyComplained = 0;
                for (ii = 0; ii < len; ii++) {
                    ch = symbol_name[ii] - '0';
                    if (ival > 214748364 || ival == 214748364 && ch >= 8) {
                        if (!AlreadyComplained)
                            SemanticError(Cg->tokenLoc, ERROR___INTEGER_CONST_OVERFLOW);
                        AlreadyComplained = 1;
                    }
                    ival = ival*10 + ch;
                }
                yylval.sc_int = ival;
                return INTCONST_SY;
            }
            break;
        case '-':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '-') {
                return MINUSMINUS_SY;
            } else if (ch == '=') {
                return ASSIGNMINUS_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '-';
            }
        case '+':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '+') {
                return PLUSPLUS_SY;
            } else if (ch == '=') {
                return ASSIGNPLUS_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '+';
            }
        case '*':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '=') {
                return ASSIGNSTAR_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '*';
            }
        case '%':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '=') {
                return ASSIGNMOD_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '%';
            }
        case ':':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == ':') {
                return COLONCOLON_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return ':';
            }
        case '=':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '=') {
                return EQ_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '=';
            }
        case '!':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '=') {
                return NE_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '!';
            }
        case '|':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '|') {
                return OR_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '|';
            }
        case '&':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '&') {
                return AND_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '&';
            }
        case '<':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '<') {
                return LL_SY;
            } else {
                if (ch == '=') {
                    return LE_SY;
                } else {
                    Cg->currentInput->ungetch(Cg->currentInput, ch);
                    return '<';
                }
            }
        case '>':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '>') {
                return GG_SY;
            } else {
                if (ch == '=') {
                    return GE_SY;
                } else {
                    Cg->currentInput->ungetch(Cg->currentInput, ch);
                    return '>';
                }
            }
        case '.':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch >= '0' && ch <= '9') {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return lFloatConst(symbol_name, 0, '.');
            } else {
                if (ch == '.') {
                    return -1; // Special EOF hack
                } else {
                    Cg->currentInput->ungetch(Cg->currentInput, ch);
                    return '.';
                }
            }
        case '/':
            ch = Cg->currentInput->getch(Cg->currentInput);
            if (ch == '/') {
                do {
                    ch = Cg->currentInput->getch(Cg->currentInput);
                } while (ch != '\n' && ch != EOF);
                if (ch == EOF)
                    return -1;
                return '\n';
            } else if (ch == '*') {
                int nlcount = 0;
                ch = Cg->currentInput->getch(Cg->currentInput);
                do {
                    while (ch != '*') {
                        if (ch == '\n') nlcount++;
                        if (ch == EOF) {
                            SemanticError(Cg->tokenLoc, ERROR___EOF_IN_COMMENT);
                            return -1;
                        }
                        ch = Cg->currentInput->getch(Cg->currentInput);
                    }
                    ch = Cg->currentInput->getch(Cg->currentInput);
                    if (ch == EOF) {
                        SemanticError(Cg->tokenLoc, ERROR___EOF_IN_COMMENT);
                        return -1;
                    }
                } while (ch != '/');
                if (nlcount) {
                    return '\n';
                }
                // Go try it again...
            } else if (ch == '=') {
                return ASSIGNSLASH_SY;
            } else {
                Cg->currentInput->ungetch(Cg->currentInput, ch);
                return '/';
            }
            break;
        case '"':
            len = 0;
            ch = Cg->currentInput->getch(Cg->currentInput);
            while (ch != '"' && ch != '\n' && ch != EOF) {
                if (ch == '\\') {
                    ch = Cg->currentInput->getch(Cg->currentInput);
                    if (ch == '\n' || ch == EOF) {
                        break;
                    }
                }
                if (len < MAX_STRING_LEN) {
                    string_val[len] = ch;
                    len++;
                    ch = Cg->currentInput->getch(Cg->currentInput);
                }
            };
            string_val[len] = '\0';
            if (ch == '"') {
                yylval.sc_ident = LookUpAddString(atable, string_val);
                return STRCONST_SY;
            } else {
                SemanticError(Cg->tokenLoc, ERROR___CPP_EOL_IN_STRING);
                return ERROR_SY;
            }
        }
    }
} // byte_scan

int scan_include_name()
{
    char buf[MAX_STRING_LEN + 1];
    int len, ch;

    if (!Cg->currentInput->getch) return 0;
    len = 0;
    while ((ch = Cg->currentInput->getch(Cg->currentInput)) > 0 &&
           ch != '\n' && ch != '>'
    ) {
        if (len < MAX_STRING_LEN)
            buf[len++] = ch;
    }
    buf[len] = 0;
    if (ch == '\n') Cg->currentInput->ungetch(Cg->currentInput, ch);
    return LookUpAddString(atable, buf);
} // scan_include_name;

int yylex(void)
{
    static int last_token = '\n';
    int token;

    for(;;) {
        token = Cg->currentInput->scan(Cg->currentInput);

        if (token == '#' && last_token == '\n') {
            readCPPline();
            continue;
        }
        last_token = token;

        // expand macros
        if (token == IDENT_SY && MacroExpand(yylval.sc_ident))
            continue;

        // convert IDENTs to reserved words or TYPEIDENT as appropriate
        if (token == IDENT_SY) {
            Cg->mostRecentToken = yylval.sc_ident;
            if (yylval.sc_ident >= FIRST_USER_TOKEN_SY) {
                Symbol *pSymb = LookUpSymbol(NULL, yylval.sc_ident);
                if (pSymb && IsTypedef(pSymb))
                    token = TYPEIDENT_SY;
            } else {
                token = yylval.sc_ident;
            }
        } else {
            Cg->mostRecentToken = token;
        }

        if (Cg->options.TraceScanner) {
            if (token >= 127)
                printf("token = %s", GetAtomString(atable, token));
            else if (token >= 32)
                printf("token = <%c>", token);
            else if (token == '\n')
                printf("token = <\\n>");
            else if (token > 0)
                printf("token = <\\0%o>", token);
            else
                printf("token = <EOF>");
            switch (token) {
            case IDENT_SY:
            case TYPEIDENT_SY:
            case STRCONST_SY:
                printf(" = \"%s\"", GetAtomString(atable, yylval.sc_ident));
                break;
            case CFLOATCONST_SY:
            case FLOATCONST_SY:
            case FLOATHCONST_SY:
            case FLOATXCONST_SY:
                printf(" = %9.6g", yylval.sc_fval);
                break;
            case INTCONST_SY:
                printf(" = %d", yylval.sc_int);
                break;
            }
            printf("\n");
        }

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

        return token;
    }
} // yylex

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