ra_ap_proc_macro_api/
lib.rs

1//! Client-side Proc-Macro crate
2//!
3//! We separate proc-macro expanding logic to an extern program to allow
4//! different implementations (e.g. wasm or dylib loading). And this crate
5//! is used to provide basic infrastructure for communication between two
6//! processes: Client (RA itself), Server (the external program)
7
8#![cfg_attr(not(feature = "sysroot-abi"), allow(unused_crate_dependencies))]
9#![cfg_attr(
10    feature = "sysroot-abi",
11    feature(proc_macro_internals, proc_macro_diagnostic, proc_macro_span)
12)]
13#![allow(internal_features)]
14
15mod codec;
16mod framing;
17pub mod legacy_protocol;
18mod process;
19
20use paths::{AbsPath, AbsPathBuf};
21use semver::Version;
22use span::{ErasedFileAstId, FIXUP_ERASED_FILE_AST_ID_MARKER, Span};
23use std::{fmt, io, sync::Arc, time::SystemTime};
24
25pub use crate::codec::Codec;
26use crate::process::ProcMacroServerProcess;
27
28/// The versions of the server protocol
29pub mod version {
30    pub const NO_VERSION_CHECK_VERSION: u32 = 0;
31    pub const VERSION_CHECK_VERSION: u32 = 1;
32    pub const ENCODE_CLOSE_SPAN_VERSION: u32 = 2;
33    pub const HAS_GLOBAL_SPANS: u32 = 3;
34    pub const RUST_ANALYZER_SPAN_SUPPORT: u32 = 4;
35    /// Whether literals encode their kind as an additional u32 field and idents their rawness as a u32 field.
36    pub const EXTENDED_LEAF_DATA: u32 = 5;
37    pub const HASHED_AST_ID: u32 = 6;
38
39    /// Current API version of the proc-macro protocol.
40    pub const CURRENT_API_VERSION: u32 = HASHED_AST_ID;
41}
42
43/// Represents different kinds of procedural macros that can be expanded by the external server.
44#[derive(Copy, Clone, Eq, PartialEq, Debug, serde_derive::Serialize, serde_derive::Deserialize)]
45pub enum ProcMacroKind {
46    /// A macro that derives implementations for a struct or enum.
47    CustomDerive,
48    /// An attribute-like procedural macro.
49    Attr,
50    // This used to be called FuncLike, so that's what the server expects currently.
51    #[serde(alias = "Bang")]
52    #[serde(rename(serialize = "FuncLike", deserialize = "FuncLike"))]
53    Bang,
54}
55
56/// A handle to an external process which load dylibs with macros (.so or .dll)
57/// and runs actual macro expansion functions.
58#[derive(Debug)]
59pub struct ProcMacroClient {
60    /// Currently, the proc macro process expands all procedural macros sequentially.
61    ///
62    /// That means that concurrent salsa requests may block each other when expanding proc macros,
63    /// which is unfortunate, but simple and good enough for the time being.
64    process: Arc<ProcMacroServerProcess>,
65    path: AbsPathBuf,
66}
67
68/// Represents a dynamically loaded library containing procedural macros.
69pub struct MacroDylib {
70    path: AbsPathBuf,
71}
72
73impl MacroDylib {
74    /// Creates a new MacroDylib instance with the given path.
75    pub fn new(path: AbsPathBuf) -> MacroDylib {
76        MacroDylib { path }
77    }
78}
79
80/// A handle to a specific proc-macro (a `#[proc_macro]` annotated function).
81///
82/// It exists within the context of a specific proc-macro server -- currently
83/// we share a single expander process for all macros within a workspace.
84#[derive(Debug, Clone)]
85pub struct ProcMacro {
86    process: Arc<ProcMacroServerProcess>,
87    dylib_path: Arc<AbsPathBuf>,
88    name: Box<str>,
89    kind: ProcMacroKind,
90    dylib_last_modified: Option<SystemTime>,
91}
92
93impl Eq for ProcMacro {}
94impl PartialEq for ProcMacro {
95    fn eq(&self, other: &Self) -> bool {
96        self.name == other.name
97            && self.kind == other.kind
98            && self.dylib_path == other.dylib_path
99            && self.dylib_last_modified == other.dylib_last_modified
100            && Arc::ptr_eq(&self.process, &other.process)
101    }
102}
103
104/// Represents errors encountered when communicating with the proc-macro server.
105#[derive(Clone, Debug)]
106pub struct ServerError {
107    pub message: String,
108    pub io: Option<Arc<io::Error>>,
109}
110
111impl fmt::Display for ServerError {
112    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
113        self.message.fmt(f)?;
114        if let Some(io) = &self.io {
115            f.write_str(": ")?;
116            io.fmt(f)?;
117        }
118        Ok(())
119    }
120}
121
122impl ProcMacroClient {
123    /// Spawns an external process as the proc macro server and returns a client connected to it.
124    pub fn spawn<'a>(
125        process_path: &AbsPath,
126        env: impl IntoIterator<
127            Item = (impl AsRef<std::ffi::OsStr>, &'a Option<impl 'a + AsRef<std::ffi::OsStr>>),
128        > + Clone,
129        version: Option<&Version>,
130    ) -> io::Result<ProcMacroClient> {
131        let process = ProcMacroServerProcess::run(process_path, env, version)?;
132        Ok(ProcMacroClient { process: Arc::new(process), path: process_path.to_owned() })
133    }
134
135    /// Returns the absolute path to the proc-macro server.
136    pub fn server_path(&self) -> &AbsPath {
137        &self.path
138    }
139
140    /// Loads a proc-macro dylib into the server process returning a list of `ProcMacro`s loaded.
141    pub fn load_dylib(&self, dylib: MacroDylib) -> Result<Vec<ProcMacro>, ServerError> {
142        let _p = tracing::info_span!("ProcMacroServer::load_dylib").entered();
143        let macros = self.process.find_proc_macros(&dylib.path)?;
144
145        let dylib_path = Arc::new(dylib.path);
146        let dylib_last_modified = std::fs::metadata(dylib_path.as_path())
147            .ok()
148            .and_then(|metadata| metadata.modified().ok());
149        match macros {
150            Ok(macros) => Ok(macros
151                .into_iter()
152                .map(|(name, kind)| ProcMacro {
153                    process: self.process.clone(),
154                    name: name.into(),
155                    kind,
156                    dylib_path: dylib_path.clone(),
157                    dylib_last_modified,
158                })
159                .collect()),
160            Err(message) => Err(ServerError { message, io: None }),
161        }
162    }
163
164    /// Checks if the proc-macro server has exited.
165    pub fn exited(&self) -> Option<&ServerError> {
166        self.process.exited()
167    }
168}
169
170impl ProcMacro {
171    /// Returns the name of the procedural macro.
172    pub fn name(&self) -> &str {
173        &self.name
174    }
175
176    /// Returns the type of procedural macro.
177    pub fn kind(&self) -> ProcMacroKind {
178        self.kind
179    }
180
181    fn needs_fixup_change(&self) -> bool {
182        let version = self.process.version();
183        (version::RUST_ANALYZER_SPAN_SUPPORT..version::HASHED_AST_ID).contains(&version)
184    }
185
186    /// On some server versions, the fixup ast id is different than ours. So change it to match.
187    fn change_fixup_to_match_old_server(&self, tt: &mut tt::TopSubtree<Span>) {
188        const OLD_FIXUP_AST_ID: ErasedFileAstId = ErasedFileAstId::from_raw(!0 - 1);
189        let change_ast_id = |ast_id: &mut ErasedFileAstId| {
190            if *ast_id == FIXUP_ERASED_FILE_AST_ID_MARKER {
191                *ast_id = OLD_FIXUP_AST_ID;
192            } else if *ast_id == OLD_FIXUP_AST_ID {
193                // Swap between them, that means no collision plus the change can be reversed by doing itself.
194                *ast_id = FIXUP_ERASED_FILE_AST_ID_MARKER;
195            }
196        };
197
198        for tt in &mut tt.0 {
199            match tt {
200                tt::TokenTree::Leaf(tt::Leaf::Ident(tt::Ident { span, .. }))
201                | tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal { span, .. }))
202                | tt::TokenTree::Leaf(tt::Leaf::Punct(tt::Punct { span, .. })) => {
203                    change_ast_id(&mut span.anchor.ast_id);
204                }
205                tt::TokenTree::Subtree(subtree) => {
206                    change_ast_id(&mut subtree.delimiter.open.anchor.ast_id);
207                    change_ast_id(&mut subtree.delimiter.close.anchor.ast_id);
208                }
209            }
210        }
211    }
212
213    /// Expands the procedural macro by sending an expansion request to the server.
214    /// This includes span information and environmental context.
215    pub fn expand(
216        &self,
217        subtree: tt::SubtreeView<'_, Span>,
218        attr: Option<tt::SubtreeView<'_, Span>>,
219        env: Vec<(String, String)>,
220        def_site: Span,
221        call_site: Span,
222        mixed_site: Span,
223        current_dir: String,
224    ) -> Result<Result<tt::TopSubtree<Span>, String>, ServerError> {
225        let (mut subtree, mut attr) = (subtree, attr);
226        let (mut subtree_changed, mut attr_changed);
227        if self.needs_fixup_change() {
228            subtree_changed = tt::TopSubtree::from_subtree(subtree);
229            self.change_fixup_to_match_old_server(&mut subtree_changed);
230            subtree = subtree_changed.view();
231
232            if let Some(attr) = &mut attr {
233                attr_changed = tt::TopSubtree::from_subtree(*attr);
234                self.change_fixup_to_match_old_server(&mut attr_changed);
235                *attr = attr_changed.view();
236            }
237        }
238
239        legacy_protocol::expand(
240            self,
241            subtree,
242            attr,
243            env,
244            def_site,
245            call_site,
246            mixed_site,
247            current_dir,
248        )
249    }
250}
ra_ap_proc_macro_api/lib.rs

ra_ap_proc_macro_api/
lib.rs
