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 #  define assert(expr)                                                  \
  95     ({                                                                  \
  96       if (expr)                                                         \
  97         ; /* empty */                                                   \
  98       else                                                              \
  99         __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION);   \
 100     })
 101 # endif
 102
 103 # ifdef __USE_GNU
 104 #  define assert_perror(errnum)                                         \
 105   (!(errnum)                                                            \
 106    ? __ASSERT_VOID_CAST (0)                                             \
 107    : __assert_perror_fail ((errnum), __FILE__, __LINE__, __ASSERT_FUNCTION))
 108 # endif
 109
 110 /* Version 2.4 and later of GCC define a magical variable `__PRETTY_FUNCTION__'
 111    which contains the name of the function currently being defined.
 112    This is broken in G++ before version 2.6.
 113    C9x has a similar variable called __func__, but prefer the GCC one since
 114    it demangles C++ function names.  */
 115 # if defined __cplusplus ? __GNUC_PREREQ (2, 6) : __GNUC_PREREQ (2, 4)
 116 #   define __ASSERT_FUNCTION    __PRETTY_FUNCTION__
 117 # else
 118 #  if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
 119 #   define __ASSERT_FUNCTION    __func__
 120 #  else
 121 #   define __ASSERT_FUNCTION    ((const char *) 0)
 122 #  endif
 123 # endif
 124
 125 #endif /* NDEBUG.  */
 126
 127
 128 #if defined __USE_ISOC11 && !defined __cplusplus
 129 # undef static_assert
 130 # define static_assert _Static_assert
 131 #endif