vfscanf.cxx

eCos1.31版

//========================================================================
//
//      vfscanf.cxx
//
//      I/O routines for vfscanf() for use with ANSI C library
//
//========================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     jlarmour
// Contributors:  jlarmour
// Date:          1998-02-13
// Purpose:     
// Description: 
// Usage:       
//
//####DESCRIPTIONEND####
//
//========================================================================
//
// This code is based on original code with the following copyright:
//
/*
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */


// CONFIGURATION

#include <pkgconf/libc.h>   // Configuration header

// Include the C library? And do we want the stdio stuff? And we have to
// have ungetc for this to work
#if defined(CYGPKG_LIBC) && defined(CYGPKG_LIBC_STDIO) && \
    defined(CYGFUN_LIBC_STDIO_ungetc) 


// INCLUDES

#include <cyg/infra/cyg_type.h>   // Common type definitions and support
#include <stdarg.h>               // Variable argument definitions
#include <stdio.h>                // Standard header for all stdio files
#include <ctype.h>                // isspace() and isupper()
#include <stdlib.h>               // standard utility functions e.g. strtol
#include "clibincl/stream.hxx"    // C library streams
#include "clibincl/stdiosupp.hxx" // Support for stdio functions

// EXPORTED SYMBOLS

externC int
vfscanf (FILE *fp, const char *fmt0, va_list ap)
    CYGPRI_LIBC_WEAK_ALIAS("_vfscanf");


#ifdef CYGSEM_LIBC_STDIO_SCANF_FLOATING_POINT

#include <float.h>

# define MAXFRACT   DBL_DIG
# define MAXEXP     DBL_MAX_10_EXP

# define BUF      (MAXEXP+MAXFRACT+3)  /* 3 = sign + decimal point + NUL */

#else // ifdef CYGSEM_LIBC_STDIO_PRINTF_FLOATING_POINT

# define BUF            40

#endif // ifdef CYGSEM_LIBC_STDIO_PRINTF_FLOATING_POINT

/*
 * Flags used during conversion.
 */

#define LONG            0x01    /* l: long or double */
#define LONGDBL         0x02    /* L: long double; unimplemented */
#define SHORT           0x04    /* h: short */
#define SUPPRESS        0x08    /* suppress assignment */
#define POINTER         0x10    /* weird %p pointer (`fake hex') */
#define NOSKIP          0x20    /* do not skip blanks */

/*
 * The following are used in numeric conversions only:
 * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
 * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
 */

#define SIGNOK          0x40    /* +/- is (still) legal */
#define NDIGITS         0x80    /* no digits detected */

#define DPTOK           0x100   /* (float) decimal point is still legal */
#define EXPOK           0x200   /* (float) exponent (e+3, etc) still
                                   legal */

#define PFXOK           0x100   /* 0x prefix is (still) legal */
#define NZDIGITS        0x200   /* no zero digits detected */

/*
 * Conversion types.
 */

#define CT_CHAR         0       /* %c conversion */
#define CT_CCL          1       /* %[...] conversion */
#define CT_STRING       2       /* %s conversion */
#define CT_INT          3       /* integer, i.e., strtol or strtoul */
#define CT_FLOAT        4       /* floating, i.e., strtod */

#if 0
#define u_char unsigned char
#endif
#define u_char char
#define u_long unsigned long

typedef unsigned long (*strtoul_t)(const char *, char **endptr, int base);

static u_char *
__sccl (char *tab, u_char *fmt);


/*
 * vfscanf
 */

#define _CAST_VOID

#define CURR_POS (file->peek_byte( (cyg_uint8 *)&curr_byte),&curr_byte )

#define INC_CURR_POS ( file->read_byte( (cyg_uint8 *)&curr_byte ) )

#define MOVE_CURR_POS(x) (file->set_position( (x), SEEK_CUR ))

#define SPACE_LEFT (file->bytes_available_to_read())

#define REFILL (file->refill_read_buffer())

#define BufferEmpty ( !SPACE_LEFT && \
                      (REFILL, (!SPACE_LEFT)) )

externC int
_vfscanf (FILE *fp, const char *fmt0, va_list ap)
{
    u_char *fmt = (u_char *) fmt0;
    int c;              /* character from format, or conversion */
    size_t width;       /* field width, or 0 */
    char *p;            /* points into all kinds of strings */
    int n;              /* handy integer */
    int flags;          /* flags as defined above */
    char *p0;           /* saves original value of p when necessary */
    int nassigned;      /* number of fields assigned */
    int nread;          /* number of characters consumed from fp */
    int base = 0;       /* base argument to strtol/strtoul */
    
    strtoul_t ccfn = NULL;      /* conversion function (strtol/strtoul) */
    char ccltab[256];           /* character class table for %[...] */
    char buf[BUF];              /* buffer for numeric conversions */

    Cyg_StdioStream *file = (Cyg_StdioStream *)fp;
    char curr_byte;

    short *sp;
    int *ip;
    float *flp;
    long double *ldp;
    double *dp;
    long *lp;

    /* `basefix' is used to avoid `if' tests in the integer scanner */
    static const short basefix[17] =
    {10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};

    nassigned = 0;
    nread = 0;
    for (;;)
    {
        c = *fmt++;
        if (c == 0)
            return nassigned;
        if (isspace (c))
        {
            for (;;)
            {
                if (BufferEmpty)
                    return nassigned;
                if (!isspace (*CURR_POS))
                    break;
                nread++, INC_CURR_POS;
            }
            continue;
        }
        if (c != '%')
            goto literal;
        width = 0;
        flags = 0;

        /*
         * switch on the format.  continue if done; break once format
         * type is derived.
         */
        
again:
        c = *fmt++;
        
        switch (c)
        {
        case '%':
literal:
            if (BufferEmpty)
                goto input_failure;
            if (*CURR_POS != c)
                goto match_failure;
            INC_CURR_POS;
            nread++;
        continue;

        case '*':
            flags |= SUPPRESS;
            goto again;
        case 'l':
            flags |= LONG;
            goto again;
        case 'L':
            flags |= LONGDBL;
            goto again;
        case 'h':
            flags |= SHORT;
            goto again;

        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            width = width * 10 + c - '0';
            goto again;

            /*
             * Conversions. Those marked `compat' are for
             * 4.[123]BSD compatibility.
             *
             * (According to ANSI, E and X formats are supposed to
             * the same as e and x.  Sorry about that.)
             */

        case 'D':               /* compat */
            flags |= LONG;
            /* FALLTHROUGH */
        case 'd':
            c = CT_INT;
            ccfn = (strtoul_t)strtol;
            base = 10;
            break;

        case 'i':
            c = CT_INT;
            ccfn = (strtoul_t)strtol;
            base = 0;
            break;

        case 'O':               /* compat */
            flags |= LONG;
            /* FALLTHROUGH */
        case 'o':
            c = CT_INT;
            ccfn = strtoul;
            base = 8;
            break;

        case 'u':
            c = CT_INT;
            ccfn = strtoul;
            base = 10;
            break;

        case 'X':               /* compat   XXX */
        case 'x':
            flags |= PFXOK;     /* enable 0x prefixing */
            c = CT_INT;
            ccfn = strtoul;
            base = 16;
            break;

        case 'E':               /* compat   XXX */
        case 'G':               /* compat   XXX */
/* ANSI says that E,G and X behave the same way as e,g,x */
            /* FALLTHROUGH */
        case 'e':
        case 'f':
        case 'g':
            c = CT_FLOAT;
            break;

        case 's':
            c = CT_STRING;
            break;

        case '[':
            fmt = __sccl (ccltab, fmt);
            flags |= NOSKIP;
            c = CT_CCL;
            break;

        case 'c':
            flags |= NOSKIP;
            c = CT_CHAR;
            break;

        case 'p':               /* pointer format is like hex */
            flags |= POINTER | PFXOK;
            c = CT_INT;
            ccfn = strtoul;
            base = 16;
            break;

        case 'n':
            if (flags & SUPPRESS)       /* ??? */
                continue;
            if (flags & SHORT)
            {
                sp = va_arg (ap, short *);
                *sp = nread;
            }
            else if (flags & LONG)
            {
                lp = va_arg (ap, long *);
                *lp = nread;
            }
            else
            {
                ip = va_arg (ap, int *);
                *ip = nread;
            }
            continue;

            /*
             * Disgusting backwards compatibility hacks.        XXX
             */
        case '\0':              /* compat */
            return EOF;

        default:                /* compat */
            if (isupper (c))
                flags |= LONG;
            c = CT_INT;
            ccfn = (strtoul_t)strtol;
            base = 10;
            break;
        }

        /*
         * We have a conversion that requires input.
         */
        if (BufferEmpty)
            goto input_failure;

        /*
         * Consume leading white space, except for formats that
         * suppress this.
         */
        if ((flags & NOSKIP) == 0)
        {
            while (isspace (*CURR_POS))
            {
                nread++;
                INC_CURR_POS;
                if (SPACE_LEFT == 0)
#ifndef REDHAT_NEC
                    if (REFILL)
#endif
                        goto input_failure;
            }
            /*
             * Note that there is at least one character in the
             * buffer, so conversions that do not set NOSKIP ca
             * no longer result in an input failure.
             */
        }

        /*
         * Do the conversion.
         */
        switch (c)
        {

        case CT_CHAR:
            /* scan arbitrary characters (sets NOSKIP) */
            if (width == 0)
                width = 1;
            if (flags & SUPPRESS)
            {
                size_t sum = 0;

                for (;;)
                {
                    if ((n = SPACE_LEFT) < (signed)width)
                    {
                        sum += n;
                        width -= n;
                        MOVE_CURR_POS(n-1);
                        INC_CURR_POS;
#ifndef REDHAT_NEC
                        if (REFILL)
                        {
#endif
                            if (sum == 0)
                                goto input_failure;
                            break;
#ifndef REDHAT_NEC
                        }
#endif
                    }
                    else
                    {
                        sum += width;
                        MOVE_CURR_POS(width - 1);
                        INC_CURR_POS;
                        break;
                    }
                }
                nread += sum;
            }
            else
            {
                /* Kludge city for the moment */
                char *dest = va_arg (ap, char *);
                int n = width;
                if (SPACE_LEFT == 0)
#ifndef REDHAT_NEC
                    if (REFILL)
#endif
                        goto input_failure;

                while (n && !BufferEmpty)
                {
                    *dest++ = *CURR_POS;
                    INC_CURR_POS;
                    n--;
                    nread++;
                }
                nassigned++;
            }
            break;

        case CT_CCL:
            /* scan a (nonempty) character class (sets NOSKIP) */
            if (width == 0)
                width = ~0;             /* `infinity' */
            /* take only those things in the class */