include/ifunc-impl-list.h

   1 /* Internal header file for __libc_supported_implementations.
   2    Copyright (C) 2012-2022 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 _IFUNC_IMPL_LIST_H
  20 #define _IFUNC_IMPL_LIST_H      1
  21
  22 #include <stdbool.h>
  23 #include <stddef.h>
  24
  25 struct libc_ifunc_impl
  26 {
  27   /* The name of function to be tested.  */
  28   const char *name;
  29   /* The address of function to be tested.  */
  30   void (*fn) (void);
  31   /* True if this implementation is usable on this machine.  */
  32   bool usable;
  33 };
  34
  35 /* Add an IFUNC implementation, IMPL, for function FUNC, to ARRAY with
  36    USABLE at index I and advance I by one.  */
  37 #define IFUNC_IMPL_ADD(array, max, func, usable, impl) \
  38   extern __typeof (func) impl attribute_hidden; \
  39   if (n < max) (array)[n++] = (struct libc_ifunc_impl) { #impl, (void (*) (void)) impl, (usable) };
  40
  41 /* Return the number of IFUNC implementations, N, for function FUNC if
  42    string NAME matches FUNC.  */
  43 #define IFUNC_IMPL(max, name, func, ...) \
  44   if (strcmp (name, #func) == 0) \
  45     { size_t n = 0;\
  46       __VA_ARGS__; \
  47       return n; \
  48     }
  49
  50 /* Fill ARRAY of MAX elements with IFUNC implementations for function
  51    NAME and return the number of valid entries.  */
  52 extern size_t __libc_ifunc_impl_list (const char *name,
  53                                       struct libc_ifunc_impl *array,
  54                                       size_t max);
  55
  56 #endif /* ifunc-impl-list.h */