// SPDX-License-Identifier: GPL-2.0 use crate::helpers::*;use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};use std::fmt::Write; fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {    let group = expect_group(it);    assert_eq!(group.delimiter(), Delimiter::Bracket);    let mut values = Vec::new();    let mut it = group.stream().into_iter();     while let Some(val) = try_string(&mut it) {        assert!(val.is_ascii(), "Expected ASCII string");        values.push(val);        match it.next() {            Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','),            None => break,            _ => panic!("Expected ',' or end of array"),        }    }    values} struct ModInfoBuilder<'a> {    module: &'a str,    counter: usize,    buffer: String,} impl<'a> ModInfoBuilder<'a> {    fn new(module: &'a str) -> Self {        ModInfoBuilder {            module,            counter: 0,            buffer: String::new(),        }    }     fn emit_base(&mut self, field: &str, content: &str, builtin: bool) {        let string = if builtin {            // Built-in modules prefix their modinfo strings by `module.`.            format!(                "{module}.{field}={content}\0",                module = self.module,                field = field,                content = content            )        } else {            // Loadable modules' modinfo strings go as-is.            format!("{field}={content}\0", field = field, content = content)        };         write!(            &mut self.buffer,            "                {cfg}                #[doc(hidden)]                #[link_section = \".modinfo\"]                #[used]                pub static __{module}_{counter}: [u8; {length}] = *{string};            ",            cfg = if builtin {                "#[cfg(not(MODULE))]"            } else {                "#[cfg(MODULE)]"            },            module = self.module.to_uppercase(),            counter = self.counter,            length = string.len(),            string = Literal::byte_string(string.as_bytes()),        )        .unwrap();         self.counter += 1;    }     fn emit_only_builtin(&mut self, field: &str, content: &str) {        self.emit_base(field, content, true)    }     fn emit_only_loadable(&mut self, field: &str, content: &str) {        self.emit_base(field, content, false)    }     fn emit(&mut self, field: &str, content: &str) {        self.emit_only_builtin(field, content);        self.emit_only_loadable(field, content);    }} #[derive(Debug, Default)]struct ModuleInfo {    type_: String,    license: String,    name: String,    author: Option<String>,    description: Option<String>,    alias: Option<Vec<String>>,} impl ModuleInfo {    fn parse(it: &mut token_stream::IntoIter) -> Self {        let mut info = ModuleInfo::default();         const EXPECTED_KEYS: &[&str] =            &["type", "name", "author", "description", "license", "alias"];        const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];        let mut seen_keys = Vec::new();         loop {            let key = match it.next() {                Some(TokenTree::Ident(ident)) => ident.to_string(),                Some(_) => panic!("Expected Ident or end"),                None => break,            };             if seen_keys.contains(&key) {                panic!(                    "Duplicated key \"{}\". Keys can only be specified once.",                    key                );            }             assert_eq!(expect_punct(it), ':');             match key.as_str() {                "type" => info.type_ = expect_ident(it),                "name" => info.name = expect_string_ascii(it),                "author" => info.author = Some(expect_string(it)),                "description" => info.description = Some(expect_string(it)),                "license" => info.license = expect_string_ascii(it),                "alias" => info.alias = Some(expect_string_array(it)),                _ => panic!(                    "Unknown key \"{}\". Valid keys are: {:?}.",                    key, EXPECTED_KEYS                ),            }             assert_eq!(expect_punct(it), ',');             seen_keys.push(key);        }         expect_end(it);         for key in REQUIRED_KEYS {            if !seen_keys.iter().any(|e| e == key) {                panic!("Missing required key \"{}\".", key);            }        }         let mut ordered_keys: Vec<&str> = Vec::new();        for key in EXPECTED_KEYS {            if seen_keys.iter().any(|e| e == key) {                ordered_keys.push(key);            }        }         if seen_keys != ordered_keys {            panic!(                "Keys are not ordered as expected. Order them like: {:?}.",                ordered_keys            );        }         info    }} pub(crate) fn module(ts: TokenStream) -> TokenStream {    let mut it = ts.into_iter();     let info = ModuleInfo::parse(&mut it);     let mut modinfo = ModInfoBuilder::new(info.name.as_ref());    if let Some(author) = info.author {        modinfo.emit("author", &author);    }    if let Some(description) = info.description {        modinfo.emit("description", &description);    }    modinfo.emit("license", &info.license);    if let Some(aliases) = info.alias {        for alias in aliases {            modinfo.emit("alias", &alias);        }    }     // Built-in modules also export the `file` modinfo string.    let file =        std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");    modinfo.emit_only_builtin("file", &file);     format!(        "            /// The module name.            ///            /// Used by the printing macros, e.g. [`info!`].            const __LOG_PREFIX: &[u8] = b\"{name}\\0\";             /// The \"Rust loadable module\" mark.            //            // This may be best done another way later on, e.g. as a new modinfo            // key or a new section. For the moment, keep it simple.            #[cfg(MODULE)]            #[doc(hidden)]            #[used]            static __IS_RUST_MODULE: () = ();             static mut __MOD: Option<{type_}> = None;             // SAFETY: `__this_module` is constructed by the kernel at load time and will not be            // freed until the module is unloaded.            #[cfg(MODULE)]            static THIS_MODULE: kernel::ThisModule = unsafe {{                kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _)            }};            #[cfg(not(MODULE))]            static THIS_MODULE: kernel::ThisModule = unsafe {{                kernel::ThisModule::from_ptr(core::ptr::null_mut())            }};             // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.            #[cfg(MODULE)]            #[doc(hidden)]            #[no_mangle]            pub extern \"C\" fn init_module() -> core::ffi::c_int {{                __init()            }}             #[cfg(MODULE)]            #[doc(hidden)]            #[no_mangle]            pub extern \"C\" fn cleanup_module() {{                __exit()            }}             // Built-in modules are initialized through an initcall pointer            // and the identifiers need to be unique.            #[cfg(not(MODULE))]            #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]            #[doc(hidden)]            #[link_section = \"{initcall_section}\"]            #[used]            pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init;             #[cfg(not(MODULE))]            #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]            core::arch::global_asm!(                r#\".section \"{initcall_section}\", \"a\"                __{name}_initcall:                    .long   __{name}_init - .                    .previous                \"#            );             #[cfg(not(MODULE))]            #[doc(hidden)]            #[no_mangle]            pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{                __init()            }}             #[cfg(not(MODULE))]            #[doc(hidden)]            #[no_mangle]            pub extern \"C\" fn __{name}_exit() {{                __exit()            }}             fn __init() -> core::ffi::c_int {{                match <{type_} as kernel::Module>::init(&THIS_MODULE) {{                    Ok(m) => {{                        unsafe {{                            __MOD = Some(m);                        }}                        return 0;                    }}                    Err(e) => {{                        return e.to_errno();                    }}                }}            }}             fn __exit() {{                unsafe {{                    // Invokes `drop()` on `__MOD`, which should be used for cleanup.                    __MOD = None;                }}            }}             {modinfo}        ",        type_ = info.type_,        name = info.name,        modinfo = modinfo.buffer,        initcall_section = ".initcall6.init"    )    .parse()    .expect("Error parsing formatted string into token stream.")}