1 // SPDX-License-Identifier: GPL-2.0
2
3 //! Build-time assert.
4
5 /// Fails the build if the code path calling `
6 ///
7 /// If the macro is executed in const context,
8 /// If the compiler or optimizer cannot guaran
9 /// be called, a build error will be triggered
10 ///
11 /// # Examples
12 ///
13 /// ```
14 /// # use kernel::build_error;
15 /// #[inline]
16 /// fn foo(a: usize) -> usize {
17 /// a.checked_add(1).unwrap_or_else(|| bui
18 /// }
19 ///
20 /// assert_eq!(foo(usize::MAX - 1), usize::MAX
21 /// // foo(usize::MAX); // Fails to compile.
22 /// ```
23 #[macro_export]
24 macro_rules! build_error {
25 () => {{
26 $crate::build_error("")
27 }};
28 ($msg:expr) => {{
29 $crate::build_error($msg)
30 }};
31 }
32
33 /// Asserts that a boolean expression is `true
34 ///
35 /// If the condition is evaluated to `false` i
36 /// will panic. If the compiler or optimizer c
37 /// be evaluated to `true`, a build error will
38 ///
39 /// [`static_assert!`] should be preferred to
40 ///
41 /// # Examples
42 ///
43 /// These examples show that different types o
44 /// at different stage of compilation. It is p
45 /// possible, so [`static_assert!`] should be
46 /// ```ignore
47 /// fn foo() {
48 /// static_assert!(1 > 1); // Compile-time
49 /// build_assert!(1 > 1); // Build-time er
50 /// assert!(1 > 1); // Run-time error
51 /// }
52 /// ```
53 ///
54 /// When the condition refers to generic param
55 /// [`static_assert!`] cannot be used. Use `bu
56 /// ```
57 /// fn foo<const N: usize>() {
58 /// // `static_assert!(N > 1);` is not all
59 /// build_assert!(N > 1); // Build-time ch
60 /// assert!(N > 1); // Run-time check
61 /// }
62 ///
63 /// #[inline]
64 /// fn bar(n: usize) {
65 /// // `static_assert!(n > 1);` is not all
66 /// build_assert!(n > 1); // Build-time ch
67 /// assert!(n > 1); // Run-time check
68 /// }
69 /// ```
70 ///
71 /// [`static_assert!`]: crate::static_assert!
72 #[macro_export]
73 macro_rules! build_assert {
74 ($cond:expr $(,)?) => {{
75 if !$cond {
76 $crate::build_error(concat!("asser
77 }
78 }};
79 ($cond:expr, $msg:expr) => {{
80 if !$cond {
81 $crate::build_error($msg);
82 }
83 }};
84 }
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.