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| 1 | +// SPDX-License-Identifier: GPL-2.0 |
| 2 | + |
| 3 | +//! Procedural macro to run KUnit tests using a user-space like syntax. |
| 4 | +//! |
| 5 | +//! Copyright (c) 2023 José Expósito <[email protected]> |
| 6 | +
|
| 7 | +use proc_macro::{Delimiter, Group, TokenStream, TokenTree}; |
| 8 | +use std::fmt::Write; |
| 9 | + |
| 10 | +pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream { |
| 11 | + let attr = attr.to_string(); |
| 12 | + |
| 13 | + if attr.is_empty() { |
| 14 | + panic!("Missing test name in `#[kunit_tests(test_name)]` macro") |
| 15 | + } |
| 16 | + |
| 17 | + if attr.len() > 255 { |
| 18 | + panic!( |
| 19 | + "The test suite name `{}` exceeds the maximum length of 255 bytes", |
| 20 | + attr |
| 21 | + ) |
| 22 | + } |
| 23 | + |
| 24 | + let mut tokens: Vec<_> = ts.into_iter().collect(); |
| 25 | + |
| 26 | + // Scan for the `mod` keyword. |
| 27 | + tokens |
| 28 | + .iter() |
| 29 | + .find_map(|token| match token { |
| 30 | + TokenTree::Ident(ident) => match ident.to_string().as_str() { |
| 31 | + "mod" => Some(true), |
| 32 | + _ => None, |
| 33 | + }, |
| 34 | + _ => None, |
| 35 | + }) |
| 36 | + .expect("`#[kunit_tests(test_name)]` attribute should only be applied to modules"); |
| 37 | + |
| 38 | + // Retrieve the main body. The main body should be the last token tree. |
| 39 | + let body = match tokens.pop() { |
| 40 | + Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group, |
| 41 | + _ => panic!("Cannot locate main body of module"), |
| 42 | + }; |
| 43 | + |
| 44 | + // Get the functions set as tests. Search for `[test]` -> `fn`. |
| 45 | + let mut body_it = body.stream().into_iter(); |
| 46 | + let mut tests = Vec::new(); |
| 47 | + while let Some(token) = body_it.next() { |
| 48 | + match token { |
| 49 | + TokenTree::Group(ident) if ident.to_string() == "[test]" => match body_it.next() { |
| 50 | + Some(TokenTree::Ident(ident)) if ident.to_string() == "fn" => { |
| 51 | + let test_name = match body_it.next() { |
| 52 | + Some(TokenTree::Ident(ident)) => ident.to_string(), |
| 53 | + _ => continue, |
| 54 | + }; |
| 55 | + tests.push(test_name); |
| 56 | + } |
| 57 | + _ => continue, |
| 58 | + }, |
| 59 | + _ => (), |
| 60 | + } |
| 61 | + } |
| 62 | + |
| 63 | + // Add `#[cfg(CONFIG_KUNIT)]` before the module declaration. |
| 64 | + let config_kunit = "#[cfg(CONFIG_KUNIT)]".to_owned().parse().unwrap(); |
| 65 | + tokens.insert( |
| 66 | + 0, |
| 67 | + TokenTree::Group(Group::new(Delimiter::None, config_kunit)), |
| 68 | + ); |
| 69 | + |
| 70 | + // Generate the test KUnit test suite and a test case for each `#[test]`. |
| 71 | + // The code generated for the following test module: |
| 72 | + // |
| 73 | + // ``` |
| 74 | + // #[kunit_tests(kunit_test_suit_name)] |
| 75 | + // mod tests { |
| 76 | + // #[test] |
| 77 | + // fn foo() { |
| 78 | + // assert_eq!(1, 1); |
| 79 | + // } |
| 80 | + // |
| 81 | + // #[test] |
| 82 | + // fn bar() { |
| 83 | + // assert_eq!(2, 2); |
| 84 | + // } |
| 85 | + // } |
| 86 | + // ``` |
| 87 | + // |
| 88 | + // Looks like: |
| 89 | + // |
| 90 | + // ``` |
| 91 | + // unsafe extern "C" fn kunit_rust_wrapper_foo(_test: *mut kernel::bindings::kunit) { foo(); } |
| 92 | + // unsafe extern "C" fn kunit_rust_wrapper_bar(_test: *mut kernel::bindings::kunit) { bar(); } |
| 93 | + // |
| 94 | + // static mut TEST_CASES: [kernel::bindings::kunit_case; 3] = [ |
| 95 | + // kernel::kunit::kunit_case(kernel::c_str!("foo"), kunit_rust_wrapper_foo), |
| 96 | + // kernel::kunit::kunit_case(kernel::c_str!("bar"), kunit_rust_wrapper_bar), |
| 97 | + // kernel::kunit::kunit_case_null(), |
| 98 | + // ]; |
| 99 | + // |
| 100 | + // kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES); |
| 101 | + // ``` |
| 102 | + let mut kunit_macros = "".to_owned(); |
| 103 | + let mut test_cases = "".to_owned(); |
| 104 | + for test in &tests { |
| 105 | + let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); |
| 106 | + let kunit_wrapper = format!( |
| 107 | + "unsafe extern \"C\" fn {}(_test: *mut kernel::bindings::kunit) {{ {}(); }}", |
| 108 | + kunit_wrapper_fn_name, test |
| 109 | + ); |
| 110 | + writeln!(kunit_macros, "{kunit_wrapper}").unwrap(); |
| 111 | + writeln!( |
| 112 | + test_cases, |
| 113 | + " kernel::kunit::kunit_case(kernel::c_str!(\"{}\"), {}),", |
| 114 | + test, kunit_wrapper_fn_name |
| 115 | + ) |
| 116 | + .unwrap(); |
| 117 | + } |
| 118 | + |
| 119 | + writeln!(kunit_macros).unwrap(); |
| 120 | + writeln!( |
| 121 | + kunit_macros, |
| 122 | + "static mut TEST_CASES: [kernel::bindings::kunit_case; {}] = [\n{test_cases} kernel::kunit::kunit_case_null(),\n];", |
| 123 | + tests.len() + 1 |
| 124 | + ) |
| 125 | + .unwrap(); |
| 126 | + |
| 127 | + writeln!( |
| 128 | + kunit_macros, |
| 129 | + "kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);" |
| 130 | + ) |
| 131 | + .unwrap(); |
| 132 | + |
| 133 | + // Remove the `#[test]` macros. |
| 134 | + // We do this at a token level, in order to preserve span information. |
| 135 | + let mut new_body = vec![]; |
| 136 | + let mut body_it = body.stream().into_iter(); |
| 137 | + |
| 138 | + while let Some(token) = body_it.next() { |
| 139 | + match token { |
| 140 | + TokenTree::Punct(ref c) if c.as_char() == '#' => match body_it.next() { |
| 141 | + Some(TokenTree::Group(group)) if group.to_string() == "[test]" => (), |
| 142 | + Some(next) => { |
| 143 | + new_body.extend([token, next]); |
| 144 | + } |
| 145 | + _ => { |
| 146 | + new_body.push(token); |
| 147 | + } |
| 148 | + }, |
| 149 | + _ => { |
| 150 | + new_body.push(token); |
| 151 | + } |
| 152 | + } |
| 153 | + } |
| 154 | + |
| 155 | + let mut new_body = TokenStream::from_iter(new_body); |
| 156 | + new_body.extend::<TokenStream>(kunit_macros.parse().unwrap()); |
| 157 | + |
| 158 | + tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, new_body))); |
| 159 | + |
| 160 | + tokens.into_iter().collect() |
| 161 | +} |
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