sysdeps/generic/_itoa.h

   1 /* Internal function for converting integers to ASCII.
   2    Copyright (C) 1994-2024 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 */