github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpz/get_str.c (about)

     1  /* mpz_get_str (string, base, mp_src) -- Convert the multiple precision
     2     number MP_SRC to a string STRING of base BASE.  If STRING is NULL
     3     allocate space for the result.  In any case, return a pointer to the
     4     result.  If STRING is not NULL, the caller must ensure enough space is
     5     available to store the result.
     6  
     7  Copyright 1991, 1993, 1994, 1996, 2000-2002, 2005, 2012 Free Software
     8  Foundation, Inc.
     9  
    10  This file is part of the GNU MP Library.
    11  
    12  The GNU MP Library is free software; you can redistribute it and/or modify
    13  it under the terms of either:
    14  
    15    * the GNU Lesser General Public License as published by the Free
    16      Software Foundation; either version 3 of the License, or (at your
    17      option) any later version.
    18  
    19  or
    20  
    21    * the GNU General Public License as published by the Free Software
    22      Foundation; either version 2 of the License, or (at your option) any
    23      later version.
    24  
    25  or both in parallel, as here.
    26  
    27  The GNU MP Library is distributed in the hope that it will be useful, but
    28  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    29  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    30  for more details.
    31  
    32  You should have received copies of the GNU General Public License and the
    33  GNU Lesser General Public License along with the GNU MP Library.  If not,
    34  see https://www.gnu.org/licenses/.  */
    35  
    36  #include <string.h> /* for strlen */
    37  #include "gmp.h"
    38  #include "gmp-impl.h"
    39  #include "longlong.h"
    40  
    41  char *
    42  mpz_get_str (char *res_str, int base, mpz_srcptr x)
    43  {
    44    mp_ptr xp;
    45    mp_size_t x_size = SIZ (x);
    46    char *return_str;
    47    size_t str_size;
    48    size_t alloc_size = 0;
    49    const char *num_to_text;
    50    int i;
    51    TMP_DECL;
    52  
    53    if (base >= 0)
    54      {
    55        num_to_text = "0123456789abcdefghijklmnopqrstuvwxyz";
    56        if (base <= 1)
    57  	base = 10;
    58        else if (base > 36)
    59  	{
    60  	  num_to_text = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
    61  	  if (base > 62)
    62  	    return NULL;
    63  	}
    64      }
    65    else
    66      {
    67        base = -base;
    68        if (base <= 1)
    69  	base = 10;
    70        else if (base > 36)
    71  	return NULL;
    72        num_to_text = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    73      }
    74  
    75    /* allocate string for the user if necessary */
    76    if (res_str == NULL)
    77      {
    78        /* digits, null terminator, possible minus sign */
    79        MPN_SIZEINBASE (alloc_size, PTR(x), ABS(x_size), base);
    80        alloc_size += 1 + (x_size<0);
    81        res_str = (char *) (*__gmp_allocate_func) (alloc_size);
    82      }
    83    return_str = res_str;
    84  
    85    if (x_size < 0)
    86      {
    87        *res_str++ = '-';
    88        x_size = -x_size;
    89      }
    90  
    91    /* mpn_get_str clobbers its input on non power-of-2 bases */
    92    TMP_MARK;
    93    xp = PTR (x);
    94    if (! POW2_P (base))
    95      {
    96        xp = TMP_ALLOC_LIMBS (x_size | 1);  /* |1 in case x_size==0 */
    97        MPN_COPY (xp, PTR (x), x_size);
    98      }
    99  
   100    str_size = mpn_get_str ((unsigned char *) res_str, base, xp, x_size);
   101    ASSERT (alloc_size == 0 || str_size <= alloc_size - (SIZ(x) < 0));
   102  
   103    /* Convert result to printable chars.  */
   104    for (i = 0; i < str_size; i++)
   105      res_str[i] = num_to_text[(int) res_str[i]];
   106    res_str[str_size] = 0;
   107  
   108    TMP_FREE;
   109  
   110    /* if allocated then resize down to the actual space required */
   111    if (alloc_size != 0)
   112      {
   113        size_t  actual_size = str_size + 1 + (res_str - return_str);
   114        ASSERT (actual_size == strlen (return_str) + 1);
   115        __GMP_REALLOCATE_FUNC_MAYBE_TYPE (return_str, alloc_size, actual_size,
   116  					char);
   117      }
   118    return return_str;
   119  }