drivers/md/dm-vdo/permassert.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright 2023 Red Hat
   4  */
   5
   6 #ifndef PERMASSERT_H
   7 #define PERMASSERT_H
   8
   9 #include <linux/compiler.h>
  10
  11 #include "errors.h"
  12
  13 /* Utilities for asserting that certain conditions are met */
  14
  15 #define STRINGIFY(X) #X
  16
  17 /*
  18  * A hack to apply the "warn if unused" attribute to an integral expression.
  19  *
  20  * Since GCC doesn't propagate the warn_unused_result attribute to conditional expressions
  21  * incorporating calls to functions with that attribute, this function can be used to wrap such an
  22  * expression. With optimization enabled, this function contributes no additional instructions, but
  23  * the warn_unused_result attribute still applies to the code calling it.
  24  */
  25 static inline int __must_check vdo_must_use(int value)
  26 {
  27         return value;
  28 }
  29
  30 /* Assert that an expression is true and return an error if it is not. */
  31 #define VDO_ASSERT(expr, ...) vdo_must_use(__VDO_ASSERT(expr, __VA_ARGS__))
  32
  33 /* Log a message if the expression is not true. */
  34 #define VDO_ASSERT_LOG_ONLY(expr, ...) __VDO_ASSERT(expr, __VA_ARGS__)
  35
  36 #define __VDO_ASSERT(expr, ...)                               \
  37         (likely(expr) ? VDO_SUCCESS                           \
  38                       : vdo_assertion_failed(STRINGIFY(expr), __FILE__, __LINE__, __VA_ARGS__))
  39
  40 /* Log an assertion failure message. */
  41 int vdo_assertion_failed(const char *expression_string, const char *file_name,
  42                          int line_number, const char *format, ...)
  43         __printf(4, 5);
  44
  45 #endif /* PERMASSERT_H */