stdio-common/_itowa.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 _ITOWA_H
  20 #define _ITOWA_H        1
  21 #include <features.h>
  22 #include <wchar.h>
  23 #include <_itoa.h>
  24
  25 /* Convert VALUE into ASCII in base BASE (2..36).
  26    Write backwards starting the character just before BUFLIM.
  27    Return the address of the first (left-to-right) character in the number.
  28    Use upper case letters iff UPPER_CASE is nonzero.  */
  29
  30 extern wchar_t *_itowa (unsigned long long int value, wchar_t *buflim,
  31                         unsigned int base, int upper_case);
  32
  33 static inline wchar_t *
  34 __attribute__ ((unused, always_inline))
  35 _itowa_word (_ITOA_WORD_TYPE value, wchar_t *buflim,
  36              unsigned int base, int upper_case)
  37 {
  38   extern const wchar_t _itowa_upper_digits[] attribute_hidden;
  39   extern const wchar_t _itowa_lower_digits[] attribute_hidden;
  40   const wchar_t *digits = (upper_case
  41                            ? _itowa_upper_digits : _itowa_lower_digits);
  42   wchar_t *bp = buflim;
  43
  44   switch (base)
  45     {
  46 #define SPECIAL(Base)                                                         \
  47     case Base:                                                                \
  48       do                                                                      \
  49         *--bp = digits[value % Base];                                         \
  50       while ((value /= Base) != 0);                                           \
  51       break
  52
  53       SPECIAL (10);
  54       SPECIAL (16);
  55       SPECIAL (8);
  56     default:
  57       do
  58         *--bp = digits[value % base];
  59       while ((value /= base) != 0);
  60     }
  61   return bp;
  62 }
  63 #undef SPECIAL
  64
  65 #if !_ITOA_NEEDED
  66 /* No need for special long long versions.  */
  67 # define _itowa(value, buf, base, upper_case) \
  68   _itowa_word (value, buf, base, upper_case)
  69 #endif
  70
  71 #endif  /* itowa.h */