assert/assert.h

   1 /* Copyright (C) 1991-2017 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    <http://www.gnu.org/licenses/>.  */
  17
  18 /*
  19  *      ISO C99 Standard: 7.2 Diagnostics       <assert.h>
  20  */
  21
  22 #ifdef  _ASSERT_H
  23
  24 # undef _ASSERT_H
  25 # undef assert
  26 # undef __ASSERT_VOID_CAST
  27
  28 # ifdef __USE_GNU
  29 #  undef assert_perror
  30 # endif
  31
  32 #endif /* assert.h      */
  33
  34 #define _ASSERT_H       1
  35 #include <features.h>
  36
  37 #if defined __cplusplus && __GNUC_PREREQ (2,95)
  38 # define __ASSERT_VOID_CAST static_cast<void>
  39 #else
  40 # define __ASSERT_VOID_CAST (void)
  41 #endif
  42
  43 /* void assert (int expression);
  44
  45    If NDEBUG is defined, do nothing.
  46    If not, and EXPRESSION is zero, print an error message and abort.  */
  47
  48 #ifdef  NDEBUG
  49
  50 # define assert(expr)           (__ASSERT_VOID_CAST (0))
  51
  52 /* void assert_perror (int errnum);
  53
  54    If NDEBUG is defined, do nothing.  If not, and ERRNUM is not zero, print an
  55    error message with the error text for ERRNUM and abort.
  56    (This is a GNU extension.) */
  57
  58 # ifdef __USE_GNU
  59 #  define assert_perror(errnum) (__ASSERT_VOID_CAST (0))
  60 # endif
  61
  62 #else /* Not NDEBUG.  */
  63
  64 __BEGIN_DECLS
  65
  66 /* This prints an "Assertion failed" message and aborts.  */
  67 extern void __assert_fail (const char *__assertion, const char *__file,
  68                            unsigned int __line, const char *__function)
  69      __THROW __attribute__ ((__noreturn__));
  70
  71 /* Likewise, but prints the error text for ERRNUM.  */
  72 extern void __assert_perror_fail (int __errnum, const char *__file,
  73                                   unsigned int __line, const char *__function)
  74      __THROW __attribute__ ((__noreturn__));
  75
  76
  77 /* The following is not at all used here but needed for standard
  78    compliance.  */
  79 extern void __assert (const char *__assertion, const char *__file, int __line)
  80      __THROW __attribute__ ((__noreturn__));
  81
  82
  83 __END_DECLS
  84
  85 /* When possible, define assert so that it does not add extra
  86    parentheses around EXPR.  Otherwise, those added parentheses would
  87    suppress warnings we'd expect to be detected by gcc's -Wparentheses.  */
  88 # if !defined __GNUC__ || defined __STRICT_ANSI__
  89 #  define assert(expr)                                                  \
  90     ((expr)                                                             \
  91      ? __ASSERT_VOID_CAST (0)                                           \
  92      : __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
  93 # else
  94 /* The first occurrence of EXPR is not evaluated due to the sizeof,
  95    but will trigger any pedantic warnings masked by the __extension__
  96    for the second occurrence.  The explicit comparison against zero is
  97    required to support function pointers and bit fields in this
  98    context, and to suppress the evaluation of variable length
  99    arrays.  */
 100 #  define assert(expr)                                                  \
 101   ((void) sizeof ((expr) == 0), __extension__ ({                        \
 102       if (expr)                                                         \
 103         ; /* empty */                                                   \
 104       else                                                              \
 105         __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION);   \
 106     }))
 107 # endif
 108
 109 # ifdef __USE_GNU
 110 #  define assert_perror(errnum)                                         \
 111   (!(errnum)                                                            \
 112    ? __ASSERT_VOID_CAST (0)                                             \
 113    : __assert_perror_fail ((errnum), __FILE__, __LINE__, __ASSERT_FUNCTION))
 114 # endif
 115
 116 /* Version 2.4 and later of GCC define a magical variable `__PRETTY_FUNCTION__'
 117    which contains the name of the function currently being defined.
 118    This is broken in G++ before version 2.6.
 119    C9x has a similar variable called __func__, but prefer the GCC one since
 120    it demangles C++ function names.  */
 121 # if defined __cplusplus ? __GNUC_PREREQ (2, 6) : __GNUC_PREREQ (2, 4)
 122 #   define __ASSERT_FUNCTION    __extension__ __PRETTY_FUNCTION__
 123 # else
 124 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 125 #   define __ASSERT_FUNCTION    __func__
 126 #  else
 127 #   define __ASSERT_FUNCTION    ((const char *) 0)
 128 #  endif
 129 # endif
 130
 131 #endif /* NDEBUG.  */
 132
 133
 134 #if defined __USE_ISOC11 && !defined __cplusplus
 135 # undef static_assert
 136 # define static_assert _Static_assert
 137 #endif