src/lxc/error_utils.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef __LXC_ERROR_UTILS_H
   4 #define __LXC_ERROR_UTILS_H
   5
   6 #include "config.h"
   7
   8 #include <stdbool.h>
   9
  10 #include "macro.h"
  11
  12 #define MAX_ERRNO 4095
  13
  14 #define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
  15
  16 static inline void *ERR_PTR(long error)
  17 {
  18         return (void *)error;
  19 }
  20
  21 static inline long PTR_ERR(const void *ptr)
  22 {
  23         return (long)ptr;
  24 }
  25
  26 static inline long IS_ERR(const void *ptr)
  27 {
  28         return IS_ERR_VALUE((unsigned long)ptr);
  29 }
  30
  31 static inline long IS_ERR_OR_NULL(const void *ptr)
  32 {
  33         return !ptr || IS_ERR_VALUE((unsigned long)ptr);
  34 }
  35
  36 static inline void *ERR_CAST(const void *ptr)
  37 {
  38         return (void *)ptr;
  39 }
  40
  41 static inline int PTR_RET(const void *ptr)
  42 {
  43         if (IS_ERR(ptr))
  44                 return PTR_ERR(ptr);
  45         else
  46                 return 0;
  47 }
  48
  49 /* Taken from Lennart tyvm. */
  50 #define CASE_F(X) case X:
  51 #define CASE_F_1(CASE, X) CASE_F(X)
  52 #define CASE_F_2(CASE, X, ...)  CASE(X) CASE_F_1(CASE, __VA_ARGS__)
  53 #define CASE_F_3(CASE, X, ...)  CASE(X) CASE_F_2(CASE, __VA_ARGS__)
  54 #define CASE_F_4(CASE, X, ...)  CASE(X) CASE_F_3(CASE, __VA_ARGS__)
  55 #define CASE_F_5(CASE, X, ...)  CASE(X) CASE_F_4(CASE, __VA_ARGS__)
  56 #define CASE_F_6(CASE, X, ...)  CASE(X) CASE_F_5(CASE, __VA_ARGS__)
  57 #define CASE_F_7(CASE, X, ...)  CASE(X) CASE_F_6(CASE, __VA_ARGS__)
  58 #define CASE_F_8(CASE, X, ...)  CASE(X) CASE_F_7(CASE, __VA_ARGS__)
  59 #define CASE_F_9(CASE, X, ...)  CASE(X) CASE_F_8(CASE, __VA_ARGS__)
  60 #define CASE_F_10(CASE, X, ...) CASE(X) CASE_F_9(CASE, __VA_ARGS__)
  61 #define CASE_F_11(CASE, X, ...) CASE(X) CASE_F_10(CASE, __VA_ARGS__)
  62 #define CASE_F_12(CASE, X, ...) CASE(X) CASE_F_11(CASE, __VA_ARGS__)
  63 #define CASE_F_13(CASE, X, ...) CASE(X) CASE_F_12(CASE, __VA_ARGS__)
  64 #define CASE_F_14(CASE, X, ...) CASE(X) CASE_F_13(CASE, __VA_ARGS__)
  65 #define CASE_F_15(CASE, X, ...) CASE(X) CASE_F_14(CASE, __VA_ARGS__)
  66 #define CASE_F_16(CASE, X, ...) CASE(X) CASE_F_15(CASE, __VA_ARGS__)
  67 #define CASE_F_17(CASE, X, ...) CASE(X) CASE_F_16(CASE, __VA_ARGS__)
  68 #define CASE_F_18(CASE, X, ...) CASE(X) CASE_F_17(CASE, __VA_ARGS__)
  69 #define CASE_F_19(CASE, X, ...) CASE(X) CASE_F_18(CASE, __VA_ARGS__)
  70 #define CASE_F_20(CASE, X, ...) CASE(X) CASE_F_19(CASE, __VA_ARGS__)
  71
  72 #define GET_CASE_F(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,NAME,...) NAME
  73 #define FOR_EACH_MAKE_CASE(...) \
  74         GET_CASE_F(__VA_ARGS__,CASE_F_20,CASE_F_19,CASE_F_18,CASE_F_17,CASE_F_16,CASE_F_15,CASE_F_14,CASE_F_13,CASE_F_12,CASE_F_11, \
  75                                CASE_F_10,CASE_F_9,CASE_F_8,CASE_F_7,CASE_F_6,CASE_F_5,CASE_F_4,CASE_F_3,CASE_F_2,CASE_F_1) \
  76                    (CASE_F,__VA_ARGS__)
  77
  78 #define XCONCATENATE(x, y) x ## y
  79 #define CONCATENATE(x, y) XCONCATENATE(x, y)
  80
  81 #define assert_static(expr)                                \
  82         struct CONCATENATE(_assert_struct_, __COUNTER__) { \
  83                 char x[(expr) ? 0 : -1];                   \
  84         }
  85
  86 #define IN_SET(x, ...)                                                      \
  87         ({                                                                  \
  88                 bool _found = false;                                        \
  89                 static const long double __assert_in_set[] __lxc_unused = { \
  90                     __VA_ARGS__};                                           \
  91                 assert_static(ARRAY_SIZE(__assert_in_set) <= 20);           \
  92                 switch (x) {                                                \
  93                         FOR_EACH_MAKE_CASE(__VA_ARGS__)                     \
  94                         _found = true;                                      \
  95                         break;                                              \
  96                 default:                                                    \
  97                         break;                                              \
  98                 }                                                           \
  99                 _found;                                                     \
 100         })
 101
 102 static inline bool ERRNO_IS_NOT_SUPPORTED(int r) {
 103         return IN_SET(abs(r), EOPNOTSUPP, ENOSYS);
 104 }
 105
 106 #endif /* __LXC_ERROR_UTILS_H */