1use crate::helpers::*;
4use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
5use std::fmt::Write;
6
7fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {
8 let group = expect_group(it);
9 assert_eq!(group.delimiter(), Delimiter::Bracket);
10 let mut values = Vec::new();
11 let mut it = group.stream().into_iter();
12
13 while let Some(val) = try_string(&mut it) {
14 assert!(val.is_ascii(), "Expected ASCII string");
15 values.push(val);
16 match it.next() {
17 Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','),
18 None => break,
19 _ => panic!("Expected ',' or end of array"),
20 }
21 }
22 values
23}
24
25struct ModInfoBuilder<'a> {
26 module: &'a str,
27 counter: usize,
28 buffer: String,
29}
30
31impl<'a> ModInfoBuilder<'a> {
32 fn new(module: &'a str) -> Self {
33 ModInfoBuilder {
34 module,
35 counter: 0,
36 buffer: String::new(),
37 }
38 }
39
40 fn emit_base(&mut self, field: &str, content: &str, builtin: bool) {
41 let string = if builtin {
42 format!(
44 "{module}.{field}={content}\0",
45 module = self.module,
46 field = field,
47 content = content
48 )
49 } else {
50 format!("{field}={content}\0")
52 };
53
54 write!(
55 &mut self.buffer,
56 "
57 {cfg}
58 #[doc(hidden)]
59 #[link_section = \".modinfo\"]
60 #[used]
61 pub static __{module}_{counter}: [u8; {length}] = *{string};
62 ",
63 cfg = if builtin {
64 "#[cfg(not(MODULE))]"
65 } else {
66 "#[cfg(MODULE)]"
67 },
68 module = self.module.to_uppercase(),
69 counter = self.counter,
70 length = string.len(),
71 string = Literal::byte_string(string.as_bytes()),
72 )
73 .unwrap();
74
75 self.counter += 1;
76 }
77
78 fn emit_only_builtin(&mut self, field: &str, content: &str) {
79 self.emit_base(field, content, true)
80 }
81
82 fn emit_only_loadable(&mut self, field: &str, content: &str) {
83 self.emit_base(field, content, false)
84 }
85
86 fn emit(&mut self, field: &str, content: &str) {
87 self.emit_only_builtin(field, content);
88 self.emit_only_loadable(field, content);
89 }
90}
91
92#[derive(Debug, Default)]
93struct ModuleInfo {
94 type_: String,
95 license: String,
96 name: String,
97 author: Option<String>,
98 description: Option<String>,
99 alias: Option<Vec<String>>,
100 firmware: Option<Vec<String>>,
101}
102
103impl ModuleInfo {
104 fn parse(it: &mut token_stream::IntoIter) -> Self {
105 let mut info = ModuleInfo::default();
106
107 const EXPECTED_KEYS: &[&str] = &[
108 "type",
109 "name",
110 "author",
111 "description",
112 "license",
113 "alias",
114 "firmware",
115 ];
116 const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
117 let mut seen_keys = Vec::new();
118
119 loop {
120 let key = match it.next() {
121 Some(TokenTree::Ident(ident)) => ident.to_string(),
122 Some(_) => panic!("Expected Ident or end"),
123 None => break,
124 };
125
126 if seen_keys.contains(&key) {
127 panic!("Duplicated key \"{key}\". Keys can only be specified once.");
128 }
129
130 assert_eq!(expect_punct(it), ':');
131
132 match key.as_str() {
133 "type" => info.type_ = expect_ident(it),
134 "name" => info.name = expect_string_ascii(it),
135 "author" => info.author = Some(expect_string(it)),
136 "description" => info.description = Some(expect_string(it)),
137 "license" => info.license = expect_string_ascii(it),
138 "alias" => info.alias = Some(expect_string_array(it)),
139 "firmware" => info.firmware = Some(expect_string_array(it)),
140 _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
141 }
142
143 assert_eq!(expect_punct(it), ',');
144
145 seen_keys.push(key);
146 }
147
148 expect_end(it);
149
150 for key in REQUIRED_KEYS {
151 if !seen_keys.iter().any(|e| e == key) {
152 panic!("Missing required key \"{key}\".");
153 }
154 }
155
156 let mut ordered_keys: Vec<&str> = Vec::new();
157 for key in EXPECTED_KEYS {
158 if seen_keys.iter().any(|e| e == key) {
159 ordered_keys.push(key);
160 }
161 }
162
163 if seen_keys != ordered_keys {
164 panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
165 }
166
167 info
168 }
169}
170
171pub(crate) fn module(ts: TokenStream) -> TokenStream {
172 let mut it = ts.into_iter();
173
174 let info = ModuleInfo::parse(&mut it);
175
176 let mut modinfo = ModInfoBuilder::new(info.name.as_ref());
177 if let Some(author) = info.author {
178 modinfo.emit("author", &author);
179 }
180 if let Some(description) = info.description {
181 modinfo.emit("description", &description);
182 }
183 modinfo.emit("license", &info.license);
184 if let Some(aliases) = info.alias {
185 for alias in aliases {
186 modinfo.emit("alias", &alias);
187 }
188 }
189 if let Some(firmware) = info.firmware {
190 for fw in firmware {
191 modinfo.emit("firmware", &fw);
192 }
193 }
194
195 let file =
197 std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
198 modinfo.emit_only_builtin("file", &file);
199
200 format!(
201 "
202 /// The module name.
203 ///
204 /// Used by the printing macros, e.g. [`info!`].
205 const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
206
207 // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
208 // freed until the module is unloaded.
209 #[cfg(MODULE)]
210 static THIS_MODULE: kernel::ThisModule = unsafe {{
211 extern \"C\" {{
212 static __this_module: kernel::types::Opaque<kernel::bindings::module>;
213 }}
214
215 kernel::ThisModule::from_ptr(__this_module.get())
216 }};
217 #[cfg(not(MODULE))]
218 static THIS_MODULE: kernel::ThisModule = unsafe {{
219 kernel::ThisModule::from_ptr(core::ptr::null_mut())
220 }};
221
222 impl kernel::ModuleMetadata for {type_} {{
223 const NAME: &'static kernel::str::CStr = kernel::c_str!(\"{name}\");
224 }}
225
226 // Double nested modules, since then nobody can access the public items inside.
227 mod __module_init {{
228 mod __module_init {{
229 use super::super::{type_};
230 use kernel::init::PinInit;
231
232 /// The \"Rust loadable module\" mark.
233 //
234 // This may be best done another way later on, e.g. as a new modinfo
235 // key or a new section. For the moment, keep it simple.
236 #[cfg(MODULE)]
237 #[doc(hidden)]
238 #[used]
239 static __IS_RUST_MODULE: () = ();
240
241 static mut __MOD: core::mem::MaybeUninit<{type_}> =
242 core::mem::MaybeUninit::uninit();
243
244 // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
245 /// # Safety
246 ///
247 /// This function must not be called after module initialization, because it may be
248 /// freed after that completes.
249 #[cfg(MODULE)]
250 #[doc(hidden)]
251 #[no_mangle]
252 #[link_section = \".init.text\"]
253 pub unsafe extern \"C\" fn init_module() -> kernel::ffi::c_int {{
254 // SAFETY: This function is inaccessible to the outside due to the double
255 // module wrapping it. It is called exactly once by the C side via its
256 // unique name.
257 unsafe {{ __init() }}
258 }}
259
260 #[cfg(MODULE)]
261 #[doc(hidden)]
262 #[used]
263 #[link_section = \".init.data\"]
264 static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
265
266 #[cfg(MODULE)]
267 #[doc(hidden)]
268 #[no_mangle]
269 pub extern \"C\" fn cleanup_module() {{
270 // SAFETY:
271 // - This function is inaccessible to the outside due to the double
272 // module wrapping it. It is called exactly once by the C side via its
273 // unique name,
274 // - furthermore it is only called after `init_module` has returned `0`
275 // (which delegates to `__init`).
276 unsafe {{ __exit() }}
277 }}
278
279 #[cfg(MODULE)]
280 #[doc(hidden)]
281 #[used]
282 #[link_section = \".exit.data\"]
283 static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
284
285 // Built-in modules are initialized through an initcall pointer
286 // and the identifiers need to be unique.
287 #[cfg(not(MODULE))]
288 #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
289 #[doc(hidden)]
290 #[link_section = \"{initcall_section}\"]
291 #[used]
292 pub static __{name}_initcall: extern \"C\" fn() -> kernel::ffi::c_int = __{name}_init;
293
294 #[cfg(not(MODULE))]
295 #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
296 core::arch::global_asm!(
297 r#\".section \"{initcall_section}\", \"a\"
298 __{name}_initcall:
299 .long __{name}_init - .
300 .previous
301 \"#
302 );
303
304 #[cfg(not(MODULE))]
305 #[doc(hidden)]
306 #[no_mangle]
307 pub extern \"C\" fn __{name}_init() -> kernel::ffi::c_int {{
308 // SAFETY: This function is inaccessible to the outside due to the double
309 // module wrapping it. It is called exactly once by the C side via its
310 // placement above in the initcall section.
311 unsafe {{ __init() }}
312 }}
313
314 #[cfg(not(MODULE))]
315 #[doc(hidden)]
316 #[no_mangle]
317 pub extern \"C\" fn __{name}_exit() {{
318 // SAFETY:
319 // - This function is inaccessible to the outside due to the double
320 // module wrapping it. It is called exactly once by the C side via its
321 // unique name,
322 // - furthermore it is only called after `__{name}_init` has returned `0`
323 // (which delegates to `__init`).
324 unsafe {{ __exit() }}
325 }}
326
327 /// # Safety
328 ///
329 /// This function must only be called once.
330 unsafe fn __init() -> kernel::ffi::c_int {{
331 let initer =
332 <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
333 // SAFETY: No data race, since `__MOD` can only be accessed by this module
334 // and there only `__init` and `__exit` access it. These functions are only
335 // called once and `__exit` cannot be called before or during `__init`.
336 match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{
337 Ok(m) => 0,
338 Err(e) => e.to_errno(),
339 }}
340 }}
341
342 /// # Safety
343 ///
344 /// This function must
345 /// - only be called once,
346 /// - be called after `__init` has been called and returned `0`.
347 unsafe fn __exit() {{
348 // SAFETY: No data race, since `__MOD` can only be accessed by this module
349 // and there only `__init` and `__exit` access it. These functions are only
350 // called once and `__init` was already called.
351 unsafe {{
352 // Invokes `drop()` on `__MOD`, which should be used for cleanup.
353 __MOD.assume_init_drop();
354 }}
355 }}
356
357 {modinfo}
358 }}
359 }}
360 ",
361 type_ = info.type_,
362 name = info.name,
363 modinfo = modinfo.buffer,
364 initcall_section = ".initcall6.init"
365 )
366 .parse()
367 .expect("Error parsing formatted string into token stream.")
368}