lib/stdnoreturn.in.h

/* A substitute for ISO C11 <stdnoreturn.h>.

   Copyright 2012-2026 Free Software Foundation, Inc.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Paul Eggert.  */

/* This file uses _Noreturn.  */
#if !_GL_CONFIG_H_INCLUDED
 #error "Please include config.h first."
#endif

#ifndef noreturn

/* ISO C11 <stdnoreturn.h> for platforms that lack it.

   References:
   ISO C11 (latest free draft
   <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf>)
   section 7.23

   <stdnoreturn.h> is obsolescent in C23, so new code should avoid it.  */

/* The definition of _Noreturn is copied here.  */

#if 1200 <= _MSC_VER || defined __CYGWIN__
/* On MSVC, standard include files contain declarations like
     __declspec (noreturn) void abort (void);
   "#define noreturn _Noreturn" would cause this declaration to be rewritten
   to the invalid
     __declspec (__declspec (noreturn)) void abort (void);

   Similarly, on Cygwin, standard include files contain declarations like
     void __cdecl abort (void) __attribute__ ((noreturn));
   "#define noreturn _Noreturn" would cause this declaration to be rewritten
   to the invalid
     void __cdecl abort (void) __attribute__ ((__attribute__ ((__noreturn__))));

   Instead, define noreturn to empty, so that such declarations are rewritten to
     __declspec () void abort (void);
   or
     void __cdecl abort (void) __attribute__ (());
   respectively.  This gives up on noreturn's advice to the compiler but at
   least it is valid code.  */
# define noreturn /*empty*/
#else
# define noreturn _Noreturn
#endif

/* Did he ever return?
   No he never returned
   And his fate is still unlearn'd ...
     -- Steiner J, Hawes BL.  M.T.A. (1949)  */

#endif /* noreturn */