xref: /linux/samples/rust/rust_print_main.rs (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 //! Rust printing macros sample.
4 
5 use kernel::pr_cont;
6 use kernel::prelude::*;
7 
8 module! {
9     type: RustPrint,
10     name: "rust_print",
11     author: "Rust for Linux Contributors",
12     description: "Rust printing macros sample",
13     license: "GPL",
14 }
15 
16 struct RustPrint;
17 
18 #[expect(clippy::disallowed_macros)]
19 fn arc_print() -> Result {
20     use kernel::sync::*;
21 
22     let a = Arc::new(1, GFP_KERNEL)?;
23     let b = UniqueArc::new("hello, world", GFP_KERNEL)?;
24 
25     // Prints the value of data in `a`.
26     pr_info!("{}", a);
27 
28     // Uses ":?" to print debug fmt of `b`.
29     pr_info!("{:?}", b);
30 
31     let a: Arc<&str> = b.into();
32     let c = a.clone();
33 
34     // Uses `dbg` to print, will move `c` (for temporary debugging purposes).
35     dbg!(c);
36 
37     // Pretty-prints the debug formatting with lower-case hexadecimal integers.
38     pr_info!("{:#x?}", a);
39 
40     Ok(())
41 }
42 
43 impl kernel::Module for RustPrint {
44     fn init(_module: &'static ThisModule) -> Result<Self> {
45         pr_info!("Rust printing macros sample (init)\n");
46 
47         pr_emerg!("Emergency message (level 0) without args\n");
48         pr_alert!("Alert message (level 1) without args\n");
49         pr_crit!("Critical message (level 2) without args\n");
50         pr_err!("Error message (level 3) without args\n");
51         pr_warn!("Warning message (level 4) without args\n");
52         pr_notice!("Notice message (level 5) without args\n");
53         pr_info!("Info message (level 6) without args\n");
54 
55         pr_info!("A line that");
56         pr_cont!(" is continued");
57         pr_cont!(" without args\n");
58 
59         pr_emerg!("{} message (level {}) with args\n", "Emergency", 0);
60         pr_alert!("{} message (level {}) with args\n", "Alert", 1);
61         pr_crit!("{} message (level {}) with args\n", "Critical", 2);
62         pr_err!("{} message (level {}) with args\n", "Error", 3);
63         pr_warn!("{} message (level {}) with args\n", "Warning", 4);
64         pr_notice!("{} message (level {}) with args\n", "Notice", 5);
65         pr_info!("{} message (level {}) with args\n", "Info", 6);
66 
67         pr_info!("A {} that", "line");
68         pr_cont!(" is {}", "continued");
69         pr_cont!(" with {}\n", "args");
70 
71         arc_print()?;
72 
73         trace::trace_rust_sample_loaded(42);
74 
75         Ok(RustPrint)
76     }
77 }
78 
79 impl Drop for RustPrint {
80     fn drop(&mut self) {
81         pr_info!("Rust printing macros sample (exit)\n");
82     }
83 }
84 
85 mod trace {
86     use core::ffi::c_int;
87 
88     kernel::declare_trace! {
89         /// # Safety
90         ///
91         /// Always safe to call.
92         unsafe fn rust_sample_loaded(magic: c_int);
93     }
94 
95     pub(crate) fn trace_rust_sample_loaded(magic: i32) {
96         // SAFETY: Always safe to call.
97         unsafe { rust_sample_loaded(magic as c_int) }
98     }
99 }
100