stdio-common/reg-printf.c

   1 /* Copyright (C) 1991-2023 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 #include <set-freeres.h>
  25
  26
  27 /* Array of functions indexed by format character.  */
  28 printf_arginfo_size_function **__printf_arginfo_table attribute_hidden;
  29 printf_function **__printf_function_table attribute_hidden;
  30
  31 __libc_lock_define_initialized (static, lock)
  32
  33 /* Register FUNC to be called to format SPEC specifiers.  */
  34 int
  35 __register_printf_specifier (int spec, printf_function converter,
  36                              printf_arginfo_size_function arginfo)
  37 {
  38   if (spec < 0 || spec > (int) UCHAR_MAX)
  39     {
  40       __set_errno (EINVAL);
  41       return -1;
  42     }
  43
  44   int result = 0;
  45   __libc_lock_lock (lock);
  46
  47   if (__printf_function_table == NULL)
  48     {
  49       __printf_arginfo_table = (printf_arginfo_size_function **)
  50         calloc (UCHAR_MAX + 1, sizeof (void *) * 2);
  51       if (__printf_arginfo_table == NULL)
  52         {
  53           result = -1;
  54           goto out;
  55         }
  56
  57       __printf_function_table = (printf_function **)
  58         (__printf_arginfo_table + UCHAR_MAX + 1);
  59     }
  60
  61   __printf_function_table[spec] = converter;
  62   __printf_arginfo_table[spec] = arginfo;
  63
  64  out:
  65   __libc_lock_unlock (lock);
  66
  67   return result;
  68 }
  69 libc_hidden_def (__register_printf_specifier)
  70 weak_alias (__register_printf_specifier, register_printf_specifier)
  71
  72
  73 /* Register FUNC to be called to format SPEC specifiers.  */
  74 int
  75 __register_printf_function (int spec, printf_function converter,
  76                             printf_arginfo_function arginfo)
  77 {
  78   return __register_printf_specifier (spec, converter,
  79                                       (printf_arginfo_size_function*) arginfo);
  80 }
  81 weak_alias (__register_printf_function, register_printf_function)
  82
  83 weak_alias (__printf_arginfo_table, __libc_reg_printf_freemem_ptr)