1  /* Internal function for converting integers to ASCII.
       2     Copyright (C) 1994-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _ITOA_H
      20  #define _ITOA_H
      21  
      22  #include <limits.h>
      23  
      24  /* When long long is different from long, by default, _itoa_word is
      25     provided to convert long to ASCII and _itoa is provided to convert
      26     long long.  A sysdeps _itoa.h can define _ITOA_NEEDED to 0 and define
      27     _ITOA_WORD_TYPE to unsigned long long int to override it so that
      28     _itoa_word is changed to convert long long to ASCII and _itoa is
      29     mapped to _itoa_word.  */
      30  
      31  #ifndef _ITOA_NEEDED
      32  # define _ITOA_NEEDED		(LONG_MAX != LLONG_MAX)
      33  #endif
      34  #ifndef _ITOA_WORD_TYPE
      35  # define _ITOA_WORD_TYPE	unsigned long int
      36  #endif
      37  
      38  
      39  /* Convert VALUE into ASCII in base BASE (2..36).
      40     Write backwards starting the character just before BUFLIM.
      41     Return the address of the first (left-to-right) character in the number.
      42     Use upper case letters iff UPPER_CASE is nonzero.  */
      43  
      44  extern char *_itoa (unsigned long long int value, char *buflim,
      45  		    unsigned int base, int upper_case) attribute_hidden;
      46  
      47  extern const char _itoa_upper_digits[];
      48  extern const char _itoa_lower_digits[];
      49  #if IS_IN (libc) || IS_IN (rtld)
      50  hidden_proto (_itoa_upper_digits)
      51  hidden_proto (_itoa_lower_digits)
      52  #endif
      53  
      54  #if IS_IN (libc)
      55  extern char *_itoa_word (_ITOA_WORD_TYPE value, char *buflim,
      56  			 unsigned int base,
      57  			 int upper_case) attribute_hidden;
      58  #else
      59  static inline char * __attribute__ ((unused, always_inline))
      60  _itoa_word (_ITOA_WORD_TYPE value, char *buflim,
      61  	    unsigned int base, int upper_case)
      62  {
      63    const char *digits = (upper_case
      64  			? _itoa_upper_digits
      65  			: _itoa_lower_digits);
      66  
      67    switch (base)
      68      {
      69  # define SPECIAL(Base)							      \
      70      case Base:								      \
      71        do								      \
      72  	*--buflim = digits[value % Base];				      \
      73        while ((value /= Base) != 0);					      \
      74        break
      75  
      76        SPECIAL (10);
      77        SPECIAL (16);
      78        SPECIAL (8);
      79      default:
      80        do
      81  	*--buflim = digits[value % base];
      82        while ((value /= base) != 0);
      83      }
      84    return buflim;
      85  }
      86  # undef SPECIAL
      87  #endif
      88  
      89  /* Similar to the _itoa functions, but output starts at buf and pointer
      90     after the last written character is returned.  */
      91  extern char *_fitoa_word (_ITOA_WORD_TYPE value, char *buf,
      92  			  unsigned int base,
      93  			  int upper_case) attribute_hidden;
      94  extern char *_fitoa (unsigned long long value, char *buf, unsigned int base,
      95  		     int upper_case) attribute_hidden;
      96  
      97  #if !_ITOA_NEEDED
      98  /* No need for special long long versions.  */
      99  # define _itoa(value, buf, base, upper_case) \
     100    _itoa_word (value, buf, base, upper_case)
     101  # define _fitoa(value, buf, base, upper_case) \
     102    _fitoa_word (value, buf, base, upper_case)
     103  #endif
     104  
     105  #endif	/* itoa.h */