lib/_Noreturn.h

   1 /* A C macro for declaring that a function does not return.
   2    Copyright (C) 2011-2020 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify it
   5    under the terms of the GNU Lesser General Public License as published
   6    by the Free Software Foundation; either version 2 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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 License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 #ifndef _Noreturn
  18 # if (defined __cplusplus \
  19       && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \
  20           || (defined _MSC_VER && 1900 <= _MSC_VER)) \
  21       && 0)
  22     /* [[noreturn]] is not practically usable, because with it the syntax
  23          extern _Noreturn void func (...);
  24        would not be valid; such a declaration would only be valid with 'extern'
  25        and '_Noreturn' swapped, or without the 'extern' keyword.  However, some
  26        AIX system header files and several gnulib header files use precisely
  27        this syntax with 'extern'.  */
  28 #  define _Noreturn [[noreturn]]
  29 # elif ((!defined __cplusplus || defined __clang__)                     \
  30         && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)  \
  31             || 4 < __GNUC__ + (7 <= __GNUC_MINOR__) \
  32             || (defined __apple_build_version__ \
  33                 ? 6000000 <= __apple_build_version__ \
  34                 : 3 < __clang_major__ + (5 <= __clang_minor__))))
  35    /* _Noreturn works as-is.  */
  36 # elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__) || 0x5110 <= __SUNPRO_C
  37 #  define _Noreturn __attribute__ ((__noreturn__))
  38 # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
  39 #  define _Noreturn __declspec (noreturn)
  40 # else
  41 #  define _Noreturn
  42 # endif
  43 #endif