1  /* __gmp_sscanf_funs -- support for formatted input from a string.
       2  
       3     THE FUNCTIONS IN THIS FILE ARE FOR INTERNAL USE ONLY.  THEY'RE ALMOST
       4     CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN
       5     FUTURE GNU MP RELEASES.
       6  
       7  Copyright 2001-2003, 2009 Free Software Foundation, Inc.
       8  
       9  This file is part of the GNU MP Library.
      10  
      11  The GNU MP Library is free software; you can redistribute it and/or modify
      12  it under the terms of either:
      13  
      14    * the GNU Lesser General Public License as published by the Free
      15      Software Foundation; either version 3 of the License, or (at your
      16      option) any later version.
      17  
      18  or
      19  
      20    * the GNU General Public License as published by the Free Software
      21      Foundation; either version 2 of the License, or (at your option) any
      22      later version.
      23  
      24  or both in parallel, as here.
      25  
      26  The GNU MP Library is distributed in the hope that it will be useful, but
      27  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      28  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      29  for more details.
      30  
      31  You should have received copies of the GNU General Public License and the
      32  GNU Lesser General Public License along with the GNU MP Library.  If not,
      33  see https://www.gnu.org/licenses/.  */
      34  
      35  #include <stdio.h>
      36  #include <stdarg.h>
      37  #include "gmp-impl.h"
      38  
      39  
      40  #if 0
      41  static int
      42  scan (const char **sp, const char *fmt, ...)
      43  {
      44      va_list ap;
      45      int ret;
      46  
      47      va_start(ap, fmt);
      48      ret = vsscanf(*sp, fmt, ap);
      49      va_end(ap);
      50  
      51      return ret;
      52  }
      53  #else
      54  static int
      55  scan (const char **sp, const char *fmt, ...)
      56  {
      57    va_list ap;
      58    void *p1, *p2;
      59    int ret;
      60  
      61    va_start (ap, fmt);
      62    p1 = va_arg (ap, void *);
      63    p2 = va_arg (ap, void *);
      64  
      65    ret = sscanf (*sp, fmt, p1, p2);
      66  
      67    va_end (ap);
      68  
      69    return ret;
      70  }
      71  #endif
      72  
      73  static void
      74  step (const char **sp, int n)
      75  {
      76    ASSERT (n >= 0);
      77  
      78    /* shouldn't push us past the end of the string */
      79  #if WANT_ASSERT
      80    {
      81      int  i;
      82      for (i = 0; i < n; i++)
      83        ASSERT ((*sp)[i] != '\0');
      84    }
      85  #endif
      86  
      87    (*sp) += n;
      88  }
      89  
      90  static int
      91  get (const char **sp)
      92  {
      93    const char  *s;
      94    int  c;
      95    s = *sp;
      96    c = (unsigned char) *s++;
      97    if (c == '\0')
      98      return EOF;
      99    *sp = s;
     100    return c;
     101  }
     102  
     103  static void
     104  unget (int c, const char **sp)
     105  {
     106    const char  *s;
     107    s = *sp;
     108    if (c == EOF)
     109      {
     110        ASSERT (*s == '\0');
     111        return;
     112      }
     113    s--;
     114    ASSERT ((unsigned char) *s == c);
     115    *sp = s;
     116  }
     117  
     118  const struct gmp_doscan_funs_t  __gmp_sscanf_funs = {
     119    (gmp_doscan_scan_t)  scan,
     120    (gmp_doscan_step_t)  step,
     121    (gmp_doscan_get_t)   get,
     122    (gmp_doscan_unget_t) unget,
     123  };