glibc/assert/assert.h

/* Copyright (C) 1991-2017 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library 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.

   The GNU C Library 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 the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/*
 *	ISO C99 Standard: 7.2 Diagnostics	<assert.h>
 */

#ifdef	_ASSERT_H

# undef	_ASSERT_H
# undef	assert
# undef __ASSERT_VOID_CAST

# ifdef	__USE_GNU
#  undef assert_perror
# endif

#endif /* assert.h	*/

#define	_ASSERT_H	1
#include <features.h>

#if defined __cplusplus && __GNUC_PREREQ (2,95)
# define __ASSERT_VOID_CAST static_cast<void>
#else
# define __ASSERT_VOID_CAST (void)
#endif

/* void assert (int expression);

   If NDEBUG is defined, do nothing.
   If not, and EXPRESSION is zero, print an error message and abort.  */

#ifdef	NDEBUG

# define assert(expr)		(__ASSERT_VOID_CAST (0))

/* void assert_perror (int errnum);

   If NDEBUG is defined, do nothing.  If not, and ERRNUM is not zero, print an
   error message with the error text for ERRNUM and abort.
   (This is a GNU extension.) */

# ifdef	__USE_GNU
#  define assert_perror(errnum)	(__ASSERT_VOID_CAST (0))
# endif

#else /* Not NDEBUG.  */

__BEGIN_DECLS

/* This prints an "Assertion failed" message and aborts.  */
extern void __assert_fail (const char *__assertion, const char *__file,
			   unsigned int __line, const char *__function)
     __THROW __attribute__ ((__noreturn__));

/* Likewise, but prints the error text for ERRNUM.  */
extern void __assert_perror_fail (int __errnum, const char *__file,
				  unsigned int __line, const char *__function)
     __THROW __attribute__ ((__noreturn__));


/* The following is not at all used here but needed for standard
   compliance.  */
extern void __assert (const char *__assertion, const char *__file, int __line)
     __THROW __attribute__ ((__noreturn__));


__END_DECLS

/* When possible, define assert so that it does not add extra
   parentheses around EXPR.  Otherwise, those added parentheses would
   suppress warnings we'd expect to be detected by gcc's -Wparentheses.  */
# if !defined __GNUC__ || defined __STRICT_ANSI__
#  define assert(expr)							\
    ((expr)								\
     ? __ASSERT_VOID_CAST (0)						\
     : __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
# else
/* The first occurrence of EXPR is not evaluated due to the sizeof,
   but will trigger any pedantic warnings masked by the __extension__
   for the second occurrence.  The explicit comparison against zero is
   required to support function pointers and bit fields in this
   context, and to suppress the evaluation of variable length
   arrays.  */
#  define assert(expr)							\
  ((void) sizeof ((expr) == 0), __extension__ ({			\
      if (expr)								\
        ; /* empty */							\
      else								\
        __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION);	\
    }))
# endif

# ifdef	__USE_GNU
#  define assert_perror(errnum)						\
  (!(errnum)								\
   ? __ASSERT_VOID_CAST (0)						\
   : __assert_perror_fail ((errnum), __FILE__, __LINE__, __ASSERT_FUNCTION))
# endif

/* Version 2.4 and later of GCC define a magical variable `__PRETTY_FUNCTION__'
   which contains the name of the function currently being defined.
   This is broken in G++ before version 2.6.
   C9x has a similar variable called __func__, but prefer the GCC one since
   it demangles C++ function names.  */
# if defined __cplusplus ? __GNUC_PREREQ (2, 6) : __GNUC_PREREQ (2, 4)
#   define __ASSERT_FUNCTION	__extension__ __PRETTY_FUNCTION__
# else
#  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
#   define __ASSERT_FUNCTION	__func__
#  else
#   define __ASSERT_FUNCTION	((const char *) 0)
#  endif
# endif

#endif /* NDEBUG.  */


#if defined __USE_ISOC11 && !defined __cplusplus
# undef static_assert
# define static_assert _Static_assert
#endif