stdio-common/reg-printf.c

   1 /* Copyright (C) 1991-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <limits.h>
  20 #include <printf.h>
  21 #include <stddef.h>
  22 #include <stdlib.h>
  23 #include <libc-lock.h>
  24
  25
  26 /* Array of functions indexed by format character.  */
  27 libc_freeres_ptr (printf_arginfo_size_function **__printf_arginfo_table)
  28   attribute_hidden;
  29 printf_function **__printf_function_table attribute_hidden;
  30
  31 __libc_lock_define_initialized (static, lock)
  32
  33 int __register_printf_specifier (int, printf_function,
  34                                  printf_arginfo_size_function);
  35 libc_hidden_proto (__register_printf_specifier)
  36 int __register_printf_function (int, printf_function,
  37                                 printf_arginfo_function);
  38
  39
  40 /* Register FUNC to be called to format SPEC specifiers.  */
  41 int
  42 __register_printf_specifier (int spec, printf_function converter,
  43                              printf_arginfo_size_function arginfo)
  44 {
  45   if (spec < 0 || spec > (int) UCHAR_MAX)
  46     {
  47       __set_errno (EINVAL);
  48       return -1;
  49     }
  50
  51   int result = 0;
  52   __libc_lock_lock (lock);
  53
  54   if (__printf_function_table == NULL)
  55     {
  56       __printf_arginfo_table = (printf_arginfo_size_function **)
  57         calloc (UCHAR_MAX + 1, sizeof (void *) * 2);
  58       if (__printf_arginfo_table == NULL)
  59         {
  60           result = -1;
  61           goto out;
  62         }
  63
  64       __printf_function_table = (printf_function **)
  65         (__printf_arginfo_table + UCHAR_MAX + 1);
  66     }
  67
  68   __printf_function_table[spec] = converter;
  69   __printf_arginfo_table[spec] = arginfo;
  70
  71  out:
  72   __libc_lock_unlock (lock);
  73
  74   return result;
  75 }
  76 libc_hidden_def (__register_printf_specifier)
  77 weak_alias (__register_printf_specifier, register_printf_specifier)
  78
  79
  80 /* Register FUNC to be called to format SPEC specifiers.  */
  81 int
  82 __register_printf_function (int spec, printf_function converter,
  83                             printf_arginfo_function arginfo)
  84 {
  85   return __register_printf_specifier (spec, converter,
  86                                       (printf_arginfo_size_function*) arginfo);
  87 }
  88 weak_alias (__register_printf_function, register_printf_function)