shared/macro.h

   1 /*
   2  * kmod - interface to kernel module operations
   3  *
   4  * Copyright (C) 2011-2013  ProFUSION embedded systems
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20 #pragma once
  21
  22 #include <stddef.h>
  23
  24 #if defined(HAVE_STATIC_ASSERT)
  25 #define assert_cc(expr) \
  26         _Static_assert((expr), #expr)
  27 #else
  28 #define assert_cc(expr) \
  29        do { (void) sizeof(char [1 - 2*!(expr)]); } while(0)
  30 #endif
  31
  32 #define check_types_match(expr1, expr2)         \
  33         ((typeof(expr1) *)0 != (typeof(expr2) *)0)
  34
  35 #define container_of(member_ptr, containing_type, member)               \
  36         ((containing_type *)                                            \
  37          ((char *)(member_ptr) - offsetof(containing_type, member))     \
  38          - check_types_match(*(member_ptr), ((containing_type *)0)->member))
  39
  40
  41 /* Two gcc extensions.
  42  * &a[0] degrades to a pointer: a different type from an array */
  43 #define _array_size_chk(arr) ({ \
  44         assert_cc(!__builtin_types_compatible_p(typeof(arr), typeof(&(arr)[0]))); \
  45         0; \
  46         })
  47
  48 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + _array_size_chk(arr))
  49
  50 /* Temporaries for importing index handling */
  51 #define NOFAIL(x) (x)
  52 #define fatal(x...) do { } while (0)
  53
  54 /* Attributes */
  55
  56 #define _must_check_ __attribute__((warn_unused_result))
  57 #define _printf_format_(a,b) __attribute__((format (printf, a, b)))
  58 #define _unused_ __attribute__((unused))
  59 #define _always_inline_ __inline__ __attribute__((always_inline))
  60 #define _cleanup_(x) __attribute__((cleanup(x)))
  61
  62 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
  63  * compiler versions */
  64 #ifndef noreturn
  65 #if __STDC_VERSION__ >= 201112L
  66 #define noreturn _Noreturn
  67 #else
  68 #define noreturn __attribute__((noreturn))
  69 #endif
  70 #endif
  71
  72 #define UNIQ __COUNTER__