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, see <http://www.gnu.org/licenses/>.
  18  */
  19 #pragma once
  20
  21 #include <stddef.h>
  22
  23 #if defined(HAVE_STATIC_ASSERT)
  24 #define assert_cc(expr) \
  25         _Static_assert((expr), #expr)
  26 #else
  27 #define assert_cc(expr) \
  28        do { (void) sizeof(char [1 - 2*!(expr)]); } while(0)
  29 #endif
  30
  31 #define check_types_match(expr1, expr2)         \
  32         ((typeof(expr1) *)0 != (typeof(expr2) *)0)
  33
  34 #define container_of(member_ptr, containing_type, member)               \
  35         ((containing_type *)                                            \
  36          ((char *)(member_ptr) - offsetof(containing_type, member))     \
  37          - check_types_match(*(member_ptr), ((containing_type *)0)->member))
  38
  39
  40 /* Two gcc extensions.
  41  * &a[0] degrades to a pointer: a different type from an array */
  42 #define _array_size_chk(arr) ({ \
  43         assert_cc(!__builtin_types_compatible_p(typeof(arr), typeof(&(arr)[0]))); \
  44         0; \
  45         })
  46
  47 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + _array_size_chk(arr))
  48
  49 #define XSTRINGIFY(x) #x
  50 #define STRINGIFY(x) XSTRINGIFY(x)
  51
  52 #define XCONCATENATE(x, y) x ## y
  53 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  54 #define UNIQ(x) CONCATENATE(x, __COUNTER__)
  55
  56 /* Temporaries for importing index handling */
  57 #define NOFAIL(x) (x)
  58 #define fatal(x...) do { } while (0)
  59
  60 /* Attributes */
  61
  62 #define _must_check_ __attribute__((warn_unused_result))
  63 #define _printf_format_(a,b) __attribute__((format (printf, a, b)))
  64 #define _unused_ __attribute__((unused))
  65 #define _always_inline_ __inline__ __attribute__((always_inline))
  66 #define _cleanup_(x) __attribute__((cleanup(x)))
  67
  68 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
  69  * compiler versions */
  70 #ifndef noreturn
  71 #if defined(HAVE_NORETURN)
  72 #define noreturn _Noreturn
  73 #else
  74 #define noreturn __attribute__((noreturn))
  75 #endif
  76 #endif