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 */
25static 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. */
41int 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 */