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1fbde52b MO |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
3 | use crate::helpers::*; | |
4 | use proc_macro::{token_stream, Literal, TokenStream, TokenTree}; | |
5 | use std::fmt::Write; | |
6 | ||
7 | struct ModInfoBuilder<'a> { | |
8 | module: &'a str, | |
9 | counter: usize, | |
10 | buffer: String, | |
11 | } | |
12 | ||
13 | impl<'a> ModInfoBuilder<'a> { | |
14 | fn new(module: &'a str) -> Self { | |
15 | ModInfoBuilder { | |
16 | module, | |
17 | counter: 0, | |
18 | buffer: String::new(), | |
19 | } | |
20 | } | |
21 | ||
22 | fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { | |
23 | let string = if builtin { | |
24 | // Built-in modules prefix their modinfo strings by `module.`. | |
25 | format!( | |
26 | "{module}.{field}={content}\0", | |
27 | module = self.module, | |
28 | field = field, | |
29 | content = content | |
30 | ) | |
31 | } else { | |
32 | // Loadable modules' modinfo strings go as-is. | |
33 | format!("{field}={content}\0", field = field, content = content) | |
34 | }; | |
35 | ||
36 | write!( | |
37 | &mut self.buffer, | |
38 | " | |
39 | {cfg} | |
40 | #[doc(hidden)] | |
41 | #[link_section = \".modinfo\"] | |
42 | #[used] | |
43 | pub static __{module}_{counter}: [u8; {length}] = *{string}; | |
44 | ", | |
45 | cfg = if builtin { | |
46 | "#[cfg(not(MODULE))]" | |
47 | } else { | |
48 | "#[cfg(MODULE)]" | |
49 | }, | |
50 | module = self.module.to_uppercase(), | |
51 | counter = self.counter, | |
52 | length = string.len(), | |
53 | string = Literal::byte_string(string.as_bytes()), | |
54 | ) | |
55 | .unwrap(); | |
56 | ||
57 | self.counter += 1; | |
58 | } | |
59 | ||
60 | fn emit_only_builtin(&mut self, field: &str, content: &str) { | |
61 | self.emit_base(field, content, true) | |
62 | } | |
63 | ||
64 | fn emit_only_loadable(&mut self, field: &str, content: &str) { | |
65 | self.emit_base(field, content, false) | |
66 | } | |
67 | ||
68 | fn emit(&mut self, field: &str, content: &str) { | |
69 | self.emit_only_builtin(field, content); | |
70 | self.emit_only_loadable(field, content); | |
71 | } | |
72 | } | |
73 | ||
74 | #[derive(Debug, Default)] | |
75 | struct ModuleInfo { | |
76 | type_: String, | |
77 | license: String, | |
78 | name: String, | |
79 | author: Option<String>, | |
80 | description: Option<String>, | |
81 | alias: Option<String>, | |
82 | } | |
83 | ||
84 | impl ModuleInfo { | |
85 | fn parse(it: &mut token_stream::IntoIter) -> Self { | |
86 | let mut info = ModuleInfo::default(); | |
87 | ||
88 | const EXPECTED_KEYS: &[&str] = | |
89 | &["type", "name", "author", "description", "license", "alias"]; | |
90 | const REQUIRED_KEYS: &[&str] = &["type", "name", "license"]; | |
91 | let mut seen_keys = Vec::new(); | |
92 | ||
93 | loop { | |
94 | let key = match it.next() { | |
95 | Some(TokenTree::Ident(ident)) => ident.to_string(), | |
96 | Some(_) => panic!("Expected Ident or end"), | |
97 | None => break, | |
98 | }; | |
99 | ||
100 | if seen_keys.contains(&key) { | |
101 | panic!( | |
102 | "Duplicated key \"{}\". Keys can only be specified once.", | |
103 | key | |
104 | ); | |
105 | } | |
106 | ||
107 | assert_eq!(expect_punct(it), ':'); | |
108 | ||
109 | match key.as_str() { | |
110 | "type" => info.type_ = expect_ident(it), | |
b13c9880 GG |
111 | "name" => info.name = expect_string_ascii(it), |
112 | "author" => info.author = Some(expect_string(it)), | |
113 | "description" => info.description = Some(expect_string(it)), | |
114 | "license" => info.license = expect_string_ascii(it), | |
115 | "alias" => info.alias = Some(expect_string_ascii(it)), | |
1fbde52b MO |
116 | _ => panic!( |
117 | "Unknown key \"{}\". Valid keys are: {:?}.", | |
118 | key, EXPECTED_KEYS | |
119 | ), | |
120 | } | |
121 | ||
122 | assert_eq!(expect_punct(it), ','); | |
123 | ||
124 | seen_keys.push(key); | |
125 | } | |
126 | ||
127 | expect_end(it); | |
128 | ||
129 | for key in REQUIRED_KEYS { | |
130 | if !seen_keys.iter().any(|e| e == key) { | |
131 | panic!("Missing required key \"{}\".", key); | |
132 | } | |
133 | } | |
134 | ||
135 | let mut ordered_keys: Vec<&str> = Vec::new(); | |
136 | for key in EXPECTED_KEYS { | |
137 | if seen_keys.iter().any(|e| e == key) { | |
138 | ordered_keys.push(key); | |
139 | } | |
140 | } | |
141 | ||
142 | if seen_keys != ordered_keys { | |
143 | panic!( | |
144 | "Keys are not ordered as expected. Order them like: {:?}.", | |
145 | ordered_keys | |
146 | ); | |
147 | } | |
148 | ||
149 | info | |
150 | } | |
151 | } | |
152 | ||
153 | pub(crate) fn module(ts: TokenStream) -> TokenStream { | |
154 | let mut it = ts.into_iter(); | |
155 | ||
156 | let info = ModuleInfo::parse(&mut it); | |
157 | ||
158 | let mut modinfo = ModInfoBuilder::new(info.name.as_ref()); | |
159 | if let Some(author) = info.author { | |
160 | modinfo.emit("author", &author); | |
161 | } | |
162 | if let Some(description) = info.description { | |
163 | modinfo.emit("description", &description); | |
164 | } | |
165 | modinfo.emit("license", &info.license); | |
166 | if let Some(alias) = info.alias { | |
167 | modinfo.emit("alias", &alias); | |
168 | } | |
169 | ||
170 | // Built-in modules also export the `file` modinfo string. | |
171 | let file = | |
172 | std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable"); | |
173 | modinfo.emit_only_builtin("file", &file); | |
174 | ||
175 | format!( | |
176 | " | |
177 | /// The module name. | |
178 | /// | |
179 | /// Used by the printing macros, e.g. [`info!`]. | |
180 | const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; | |
181 | ||
182 | /// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`. | |
183 | // | |
184 | // This may be best done another way later on, e.g. as a new modinfo | |
185 | // key or a new section. For the moment, keep it simple. | |
186 | #[cfg(MODULE)] | |
187 | #[doc(hidden)] | |
188 | #[used] | |
189 | static __IS_RUST_MODULE: () = (); | |
190 | ||
191 | static mut __MOD: Option<{type_}> = None; | |
192 | ||
193 | // SAFETY: `__this_module` is constructed by the kernel at load time and will not be | |
194 | // freed until the module is unloaded. | |
195 | #[cfg(MODULE)] | |
196 | static THIS_MODULE: kernel::ThisModule = unsafe {{ | |
197 | kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _) | |
198 | }}; | |
199 | #[cfg(not(MODULE))] | |
200 | static THIS_MODULE: kernel::ThisModule = unsafe {{ | |
201 | kernel::ThisModule::from_ptr(core::ptr::null_mut()) | |
202 | }}; | |
203 | ||
204 | // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. | |
205 | #[cfg(MODULE)] | |
206 | #[doc(hidden)] | |
207 | #[no_mangle] | |
208 | pub extern \"C\" fn init_module() -> core::ffi::c_int {{ | |
209 | __init() | |
210 | }} | |
211 | ||
212 | #[cfg(MODULE)] | |
213 | #[doc(hidden)] | |
214 | #[no_mangle] | |
215 | pub extern \"C\" fn cleanup_module() {{ | |
216 | __exit() | |
217 | }} | |
218 | ||
219 | // Built-in modules are initialized through an initcall pointer | |
220 | // and the identifiers need to be unique. | |
221 | #[cfg(not(MODULE))] | |
222 | #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] | |
223 | #[doc(hidden)] | |
224 | #[link_section = \"{initcall_section}\"] | |
225 | #[used] | |
226 | pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init; | |
227 | ||
228 | #[cfg(not(MODULE))] | |
229 | #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] | |
230 | core::arch::global_asm!( | |
231 | r#\".section \"{initcall_section}\", \"a\" | |
232 | __{name}_initcall: | |
233 | .long __{name}_init - . | |
234 | .previous | |
235 | \"# | |
236 | ); | |
237 | ||
238 | #[cfg(not(MODULE))] | |
239 | #[doc(hidden)] | |
240 | #[no_mangle] | |
241 | pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{ | |
242 | __init() | |
243 | }} | |
244 | ||
245 | #[cfg(not(MODULE))] | |
246 | #[doc(hidden)] | |
247 | #[no_mangle] | |
248 | pub extern \"C\" fn __{name}_exit() {{ | |
249 | __exit() | |
250 | }} | |
251 | ||
252 | fn __init() -> core::ffi::c_int {{ | |
253 | match <{type_} as kernel::Module>::init(&THIS_MODULE) {{ | |
254 | Ok(m) => {{ | |
255 | unsafe {{ | |
256 | __MOD = Some(m); | |
257 | }} | |
258 | return 0; | |
259 | }} | |
260 | Err(e) => {{ | |
261 | return e.to_kernel_errno(); | |
262 | }} | |
263 | }} | |
264 | }} | |
265 | ||
266 | fn __exit() {{ | |
267 | unsafe {{ | |
268 | // Invokes `drop()` on `__MOD`, which should be used for cleanup. | |
269 | __MOD = None; | |
270 | }} | |
271 | }} | |
272 | ||
273 | {modinfo} | |
274 | ", | |
275 | type_ = info.type_, | |
276 | name = info.name, | |
277 | modinfo = modinfo.buffer, | |
278 | initcall_section = ".initcall6.init" | |
279 | ) | |
280 | .parse() | |
281 | .expect("Error parsing formatted string into token stream.") | |
282 | } |