src/tools/rust-analyzer/crates/rust-analyzer/src/reload.rs

   1 //! Project loading & configuration updates.
   2 //!
   3 //! This is quite tricky. The main problem is time and changes -- there's no
   4 //! fixed "project" rust-analyzer is working with, "current project" is itself
   5 //! mutable state. For example, when the user edits `Cargo.toml` by adding a new
   6 //! dependency, project model changes. What's more, switching project model is
   7 //! not instantaneous -- it takes time to run `cargo metadata` and (for proc
   8 //! macros) `cargo check`.
   9 //!
  10 //! The main guiding principle here is, as elsewhere in rust-analyzer,
  11 //! robustness. We try not to assume that the project model exists or is
  12 //! correct. Instead, we try to provide a best-effort service. Even if the
  13 //! project is currently loading and we don't have a full project model, we
  14 //! still want to respond to various  requests.
  15 use std::{mem, sync::Arc};
  16
  17 use flycheck::{FlycheckConfig, FlycheckHandle};
  18 use hir::db::DefDatabase;
  19 use ide::Change;
  20 use ide_db::base_db::{
  21     CrateGraph, Env, ProcMacro, ProcMacroExpander, ProcMacroExpansionError, ProcMacroKind,
  22     ProcMacroLoadResult, SourceRoot, VfsPath,
  23 };
  24 use proc_macro_api::{MacroDylib, ProcMacroServer};
  25 use project_model::{ProjectWorkspace, WorkspaceBuildScripts};
  26 use syntax::SmolStr;
  27 use vfs::{file_set::FileSetConfig, AbsPath, AbsPathBuf, ChangeKind};
  28
  29 use crate::{
  30     config::{Config, FilesWatcher, LinkedProject},
  31     global_state::GlobalState,
  32     lsp_ext,
  33     main_loop::Task,
  34     op_queue::Cause,
  35 };
  36
  37 #[derive(Debug)]
  38 pub(crate) enum ProjectWorkspaceProgress {
  39     Begin,
  40     Report(String),
  41     End(Vec<anyhow::Result<ProjectWorkspace>>),
  42 }
  43
  44 #[derive(Debug)]
  45 pub(crate) enum BuildDataProgress {
  46     Begin,
  47     Report(String),
  48     End((Arc<Vec<ProjectWorkspace>>, Vec<anyhow::Result<WorkspaceBuildScripts>>)),
  49 }
  50
  51 impl GlobalState {
  52     pub(crate) fn is_quiescent(&self) -> bool {
  53         !(self.fetch_workspaces_queue.op_in_progress()
  54             || self.fetch_build_data_queue.op_in_progress()
  55             || self.vfs_progress_config_version < self.vfs_config_version
  56             || self.vfs_progress_n_done < self.vfs_progress_n_total)
  57     }
  58
  59     pub(crate) fn update_configuration(&mut self, config: Config) {
  60         let _p = profile::span("GlobalState::update_configuration");
  61         let old_config = mem::replace(&mut self.config, Arc::new(config));
  62         if self.config.lru_capacity() != old_config.lru_capacity() {
  63             self.analysis_host.update_lru_capacity(self.config.lru_capacity());
  64         }
  65         if self.config.linked_projects() != old_config.linked_projects() {
  66             self.fetch_workspaces_queue.request_op("linked projects changed".to_string())
  67         } else if self.config.flycheck() != old_config.flycheck() {
  68             self.reload_flycheck();
  69         }
  70
  71         if self.analysis_host.raw_database().enable_proc_attr_macros()
  72             != self.config.expand_proc_attr_macros()
  73         {
  74             self.analysis_host
  75                 .raw_database_mut()
  76                 .set_enable_proc_attr_macros(self.config.expand_proc_attr_macros());
  77         }
  78     }
  79
  80     pub(crate) fn current_status(&self) -> lsp_ext::ServerStatusParams {
  81         let mut status = lsp_ext::ServerStatusParams {
  82             health: lsp_ext::Health::Ok,
  83             quiescent: self.is_quiescent(),
  84             message: None,
  85         };
  86
  87         if self.proc_macro_changed {
  88             status.health = lsp_ext::Health::Warning;
  89             status.message =
  90                 Some("Reload required due to source changes of a procedural macro.".into())
  91         }
  92         if let Err(_) = self.fetch_build_data_error() {
  93             status.health = lsp_ext::Health::Warning;
  94             status.message =
  95                 Some("Failed to run build scripts of some packages, check the logs.".to_string());
  96         }
  97         if !self.config.cargo_autoreload()
  98             && self.is_quiescent()
  99             && self.fetch_workspaces_queue.op_requested()
 100         {
 101             status.health = lsp_ext::Health::Warning;
 102             status.message = Some("Workspace reload required".to_string())
 103         }
 104
 105         if let Err(error) = self.fetch_workspace_error() {
 106             status.health = lsp_ext::Health::Error;
 107             status.message = Some(error)
 108         }
 109
 110         if self.config.linked_projects().is_empty()
 111             && self.config.detached_files().is_empty()
 112             && self.config.notifications().cargo_toml_not_found
 113         {
 114             status.health = lsp_ext::Health::Warning;
 115             status.message = Some("Workspace reload required".to_string())
 116         }
 117         status
 118     }
 119
 120     pub(crate) fn fetch_workspaces(&mut self, cause: Cause) {
 121         tracing::info!(%cause, "will fetch workspaces");
 122
 123         self.task_pool.handle.spawn_with_sender({
 124             let linked_projects = self.config.linked_projects();
 125             let detached_files = self.config.detached_files().to_vec();
 126             let cargo_config = self.config.cargo();
 127
 128             move |sender| {
 129                 let progress = {
 130                     let sender = sender.clone();
 131                     move |msg| {
 132                         sender
 133                             .send(Task::FetchWorkspace(ProjectWorkspaceProgress::Report(msg)))
 134                             .unwrap()
 135                     }
 136                 };
 137
 138                 sender.send(Task::FetchWorkspace(ProjectWorkspaceProgress::Begin)).unwrap();
 139
 140                 let mut workspaces = linked_projects
 141                     .iter()
 142                     .map(|project| match project {
 143                         LinkedProject::ProjectManifest(manifest) => {
 144                             project_model::ProjectWorkspace::load(
 145                                 manifest.clone(),
 146                                 &cargo_config,
 147                                 &progress,
 148                             )
 149                         }
 150                         LinkedProject::InlineJsonProject(it) => {
 151                             project_model::ProjectWorkspace::load_inline(
 152                                 it.clone(),
 153                                 cargo_config.target.as_deref(),
 154                                 &cargo_config.extra_env,
 155                             )
 156                         }
 157                     })
 158                     .collect::<Vec<_>>();
 159
 160                 if !detached_files.is_empty() {
 161                     workspaces
 162                         .push(project_model::ProjectWorkspace::load_detached_files(detached_files));
 163                 }
 164
 165                 tracing::info!("did fetch workspaces {:?}", workspaces);
 166                 sender
 167                     .send(Task::FetchWorkspace(ProjectWorkspaceProgress::End(workspaces)))
 168                     .unwrap();
 169             }
 170         });
 171     }
 172
 173     pub(crate) fn fetch_build_data(&mut self, cause: Cause) {
 174         tracing::info!(%cause, "will fetch build data");
 175         let workspaces = Arc::clone(&self.workspaces);
 176         let config = self.config.cargo();
 177         self.task_pool.handle.spawn_with_sender(move |sender| {
 178             sender.send(Task::FetchBuildData(BuildDataProgress::Begin)).unwrap();
 179
 180             let progress = {
 181                 let sender = sender.clone();
 182                 move |msg| {
 183                     sender.send(Task::FetchBuildData(BuildDataProgress::Report(msg))).unwrap()
 184                 }
 185             };
 186             let res = ProjectWorkspace::run_all_build_scripts(&workspaces, &config, &progress);
 187
 188             sender.send(Task::FetchBuildData(BuildDataProgress::End((workspaces, res)))).unwrap();
 189         });
 190     }
 191
 192     pub(crate) fn switch_workspaces(&mut self, cause: Cause) {
 193         let _p = profile::span("GlobalState::switch_workspaces");
 194         tracing::info!(%cause, "will switch workspaces");
 195
 196         if let Err(error_message) = self.fetch_workspace_error() {
 197             self.show_and_log_error(error_message, None);
 198             if !self.workspaces.is_empty() {
 199                 // It only makes sense to switch to a partially broken workspace
 200                 // if we don't have any workspace at all yet.
 201                 return;
 202             }
 203         }
 204
 205         if let Err(error) = self.fetch_build_data_error() {
 206             self.show_and_log_error("failed to run build scripts".to_string(), Some(error));
 207         }
 208
 209         let Some(workspaces) = self.fetch_workspaces_queue.last_op_result() else { return; };
 210         let workspaces =
 211             workspaces.iter().filter_map(|res| res.as_ref().ok().cloned()).collect::<Vec<_>>();
 212
 213         fn eq_ignore_build_data<'a>(
 214             left: &'a ProjectWorkspace,
 215             right: &'a ProjectWorkspace,
 216         ) -> bool {
 217             let key = |p: &'a ProjectWorkspace| match p {
 218                 ProjectWorkspace::Cargo {
 219                     cargo,
 220                     sysroot,
 221                     rustc,
 222                     rustc_cfg,
 223                     cfg_overrides,
 224
 225                     build_scripts: _,
 226                     toolchain: _,
 227                 } => Some((cargo, sysroot, rustc, rustc_cfg, cfg_overrides)),
 228                 _ => None,
 229             };
 230             match (key(left), key(right)) {
 231                 (Some(lk), Some(rk)) => lk == rk,
 232                 _ => left == right,
 233             }
 234         }
 235
 236         let same_workspaces = workspaces.len() == self.workspaces.len()
 237             && workspaces
 238                 .iter()
 239                 .zip(self.workspaces.iter())
 240                 .all(|(l, r)| eq_ignore_build_data(l, r));
 241
 242         if same_workspaces {
 243             let (workspaces, build_scripts) = self.fetch_build_data_queue.last_op_result();
 244             if Arc::ptr_eq(workspaces, &self.workspaces) {
 245                 tracing::debug!("set build scripts to workspaces");
 246
 247                 let workspaces = workspaces
 248                     .iter()
 249                     .cloned()
 250                     .zip(build_scripts)
 251                     .map(|(mut ws, bs)| {
 252                         ws.set_build_scripts(bs.as_ref().ok().cloned().unwrap_or_default());
 253                         ws
 254                     })
 255                     .collect::<Vec<_>>();
 256
 257                 // Workspaces are the same, but we've updated build data.
 258                 self.workspaces = Arc::new(workspaces);
 259             } else {
 260                 tracing::info!("build scripts do not match the version of the active workspace");
 261                 // Current build scripts do not match the version of the active
 262                 // workspace, so there's nothing for us to update.
 263                 return;
 264             }
 265         } else {
 266             tracing::debug!("abandon build scripts for workspaces");
 267
 268             // Here, we completely changed the workspace (Cargo.toml edit), so
 269             // we don't care about build-script results, they are stale.
 270             self.workspaces = Arc::new(workspaces)
 271         }
 272
 273         if let FilesWatcher::Client = self.config.files().watcher {
 274             let registration_options = lsp_types::DidChangeWatchedFilesRegistrationOptions {
 275                 watchers: self
 276                     .workspaces
 277                     .iter()
 278                     .flat_map(|ws| ws.to_roots())
 279                     .filter(|it| it.is_local)
 280                     .flat_map(|root| {
 281                         root.include.into_iter().flat_map(|it| {
 282                             [
 283                                 format!("{}/**/*.rs", it.display()),
 284                                 format!("{}/**/Cargo.toml", it.display()),
 285                                 format!("{}/**/Cargo.lock", it.display()),
 286                             ]
 287                         })
 288                     })
 289                     .map(|glob_pattern| lsp_types::FileSystemWatcher { glob_pattern, kind: None })
 290                     .collect(),
 291             };
 292             let registration = lsp_types::Registration {
 293                 id: "workspace/didChangeWatchedFiles".to_string(),
 294                 method: "workspace/didChangeWatchedFiles".to_string(),
 295                 register_options: Some(serde_json::to_value(registration_options).unwrap()),
 296             };
 297             self.send_request::<lsp_types::request::RegisterCapability>(
 298                 lsp_types::RegistrationParams { registrations: vec![registration] },
 299                 |_, _| (),
 300             );
 301         }
 302
 303         let mut change = Change::new();
 304
 305         let files_config = self.config.files();
 306         let project_folders = ProjectFolders::new(&self.workspaces, &files_config.exclude);
 307
 308         if self.proc_macro_clients.is_empty() {
 309             if let Some((path, path_manually_set)) = self.config.proc_macro_srv() {
 310                 tracing::info!("Spawning proc-macro servers");
 311                 self.proc_macro_clients = self
 312                     .workspaces
 313                     .iter()
 314                     .map(|ws| {
 315                         let (path, args): (_, &[_]) = if path_manually_set {
 316                             tracing::debug!(
 317                                 "Pro-macro server path explicitly set: {}",
 318                                 path.display()
 319                             );
 320                             (path.clone(), &[])
 321                         } else {
 322                             match ws.find_sysroot_proc_macro_srv() {
 323                                 Some(server_path) => (server_path, &[]),
 324                                 None => (path.clone(), &["proc-macro"]),
 325                             }
 326                         };
 327
 328                         tracing::info!(?args, "Using proc-macro server at {}", path.display(),);
 329                         ProcMacroServer::spawn(path.clone(), args).map_err(|err| {
 330                             let error = format!(
 331                                 "Failed to run proc-macro server from path {}, error: {:?}",
 332                                 path.display(),
 333                                 err
 334                             );
 335                             tracing::error!(error);
 336                             error
 337                         })
 338                     })
 339                     .collect()
 340             };
 341         }
 342
 343         let watch = match files_config.watcher {
 344             FilesWatcher::Client => vec![],
 345             FilesWatcher::Server => project_folders.watch,
 346         };
 347         self.vfs_config_version += 1;
 348         self.loader.handle.set_config(vfs::loader::Config {
 349             load: project_folders.load,
 350             watch,
 351             version: self.vfs_config_version,
 352         });
 353
 354         // Create crate graph from all the workspaces
 355         let crate_graph = {
 356             let dummy_replacements = self.config.dummy_replacements();
 357
 358             let vfs = &mut self.vfs.write().0;
 359             let loader = &mut self.loader;
 360             let mem_docs = &self.mem_docs;
 361             let mut load = move |path: &AbsPath| {
 362                 let _p = profile::span("GlobalState::load");
 363                 let vfs_path = vfs::VfsPath::from(path.to_path_buf());
 364                 if !mem_docs.contains(&vfs_path) {
 365                     let contents = loader.handle.load_sync(path);
 366                     vfs.set_file_contents(vfs_path.clone(), contents);
 367                 }
 368                 let res = vfs.file_id(&vfs_path);
 369                 if res.is_none() {
 370                     tracing::warn!("failed to load {}", path.display())
 371                 }
 372                 res
 373             };
 374
 375             let mut crate_graph = CrateGraph::default();
 376             for (idx, ws) in self.workspaces.iter().enumerate() {
 377                 let proc_macro_client = match self.proc_macro_clients.get(idx) {
 378                     Some(res) => res.as_ref().map_err(|e| &**e),
 379                     None => Err("Proc macros are disabled"),
 380                 };
 381                 let mut load_proc_macro = move |crate_name: &str, path: &AbsPath| {
 382                     load_proc_macro(
 383                         proc_macro_client,
 384                         path,
 385                         dummy_replacements.get(crate_name).map(|v| &**v).unwrap_or_default(),
 386                     )
 387                 };
 388                 crate_graph.extend(ws.to_crate_graph(
 389                     &mut load_proc_macro,
 390                     &mut load,
 391                     &self.config.cargo().extra_env,
 392                 ));
 393             }
 394             crate_graph
 395         };
 396         change.set_crate_graph(crate_graph);
 397
 398         self.source_root_config = project_folders.source_root_config;
 399
 400         self.analysis_host.apply_change(change);
 401         self.process_changes();
 402         self.reload_flycheck();
 403         tracing::info!("did switch workspaces");
 404     }
 405
 406     fn fetch_workspace_error(&self) -> Result<(), String> {
 407         let mut buf = String::new();
 408
 409         let Some(last_op_result) = self.fetch_workspaces_queue.last_op_result() else { return Ok(()) };
 410         if last_op_result.is_empty() {
 411             stdx::format_to!(buf, "rust-analyzer failed to discover workspace");
 412         } else {
 413             for ws in last_op_result {
 414                 if let Err(err) = ws {
 415                     stdx::format_to!(buf, "rust-analyzer failed to load workspace: {:#}\n", err);
 416                 }
 417             }
 418         }
 419
 420         if buf.is_empty() {
 421             return Ok(());
 422         }
 423
 424         Err(buf)
 425     }
 426
 427     fn fetch_build_data_error(&self) -> Result<(), String> {
 428         let mut buf = String::new();
 429
 430         for ws in &self.fetch_build_data_queue.last_op_result().1 {
 431             match ws {
 432                 Ok(data) => match data.error() {
 433                     Some(stderr) => stdx::format_to!(buf, "{:#}\n", stderr),
 434                     _ => (),
 435                 },
 436                 // io errors
 437                 Err(err) => stdx::format_to!(buf, "{:#}\n", err),
 438             }
 439         }
 440
 441         if buf.is_empty() {
 442             Ok(())
 443         } else {
 444             Err(buf)
 445         }
 446     }
 447
 448     fn reload_flycheck(&mut self) {
 449         let _p = profile::span("GlobalState::reload_flycheck");
 450         let config = match self.config.flycheck() {
 451             Some(it) => it,
 452             None => {
 453                 self.flycheck = Arc::new([]);
 454                 self.diagnostics.clear_check_all();
 455                 return;
 456             }
 457         };
 458
 459         let sender = self.flycheck_sender.clone();
 460         let invocation_strategy = match config {
 461             FlycheckConfig::CargoCommand { .. } => flycheck::InvocationStrategy::PerWorkspace,
 462             FlycheckConfig::CustomCommand { invocation_strategy, .. } => invocation_strategy,
 463         };
 464
 465         self.flycheck = match invocation_strategy {
 466             flycheck::InvocationStrategy::Once => vec![FlycheckHandle::spawn(
 467                 0,
 468                 Box::new(move |msg| sender.send(msg).unwrap()),
 469                 config.clone(),
 470                 self.config.root_path().clone(),
 471             )],
 472             flycheck::InvocationStrategy::PerWorkspace => {
 473                 self.workspaces
 474                     .iter()
 475                     .enumerate()
 476                     .filter_map(|(id, w)| match w {
 477                         ProjectWorkspace::Cargo { cargo, .. } => Some((id, cargo.workspace_root())),
 478                         ProjectWorkspace::Json { project, .. } => {
 479                             // Enable flychecks for json projects if a custom flycheck command was supplied
 480                             // in the workspace configuration.
 481                             match config {
 482                                 FlycheckConfig::CustomCommand { .. } => Some((id, project.path())),
 483                                 _ => None,
 484                             }
 485                         }
 486                         ProjectWorkspace::DetachedFiles { .. } => None,
 487                     })
 488                     .map(|(id, root)| {
 489                         let sender = sender.clone();
 490                         FlycheckHandle::spawn(
 491                             id,
 492                             Box::new(move |msg| sender.send(msg).unwrap()),
 493                             config.clone(),
 494                             root.to_path_buf(),
 495                         )
 496                     })
 497                     .collect()
 498             }
 499         }
 500         .into();
 501     }
 502 }
 503
 504 #[derive(Default)]
 505 pub(crate) struct ProjectFolders {
 506     pub(crate) load: Vec<vfs::loader::Entry>,
 507     pub(crate) watch: Vec<usize>,
 508     pub(crate) source_root_config: SourceRootConfig,
 509 }
 510
 511 impl ProjectFolders {
 512     pub(crate) fn new(
 513         workspaces: &[ProjectWorkspace],
 514         global_excludes: &[AbsPathBuf],
 515     ) -> ProjectFolders {
 516         let mut res = ProjectFolders::default();
 517         let mut fsc = FileSetConfig::builder();
 518         let mut local_filesets = vec![];
 519
 520         for root in workspaces.iter().flat_map(|ws| ws.to_roots()) {
 521             let file_set_roots: Vec<VfsPath> =
 522                 root.include.iter().cloned().map(VfsPath::from).collect();
 523
 524             let entry = {
 525                 let mut dirs = vfs::loader::Directories::default();
 526                 dirs.extensions.push("rs".into());
 527                 dirs.include.extend(root.include);
 528                 dirs.exclude.extend(root.exclude);
 529                 for excl in global_excludes {
 530                     if dirs
 531                         .include
 532                         .iter()
 533                         .any(|incl| incl.starts_with(excl) || excl.starts_with(incl))
 534                     {
 535                         dirs.exclude.push(excl.clone());
 536                     }
 537                 }
 538
 539                 vfs::loader::Entry::Directories(dirs)
 540             };
 541
 542             if root.is_local {
 543                 res.watch.push(res.load.len());
 544             }
 545             res.load.push(entry);
 546
 547             if root.is_local {
 548                 local_filesets.push(fsc.len());
 549             }
 550             fsc.add_file_set(file_set_roots)
 551         }
 552
 553         let fsc = fsc.build();
 554         res.source_root_config = SourceRootConfig { fsc, local_filesets };
 555
 556         res
 557     }
 558 }
 559
 560 #[derive(Default, Debug)]
 561 pub(crate) struct SourceRootConfig {
 562     pub(crate) fsc: FileSetConfig,
 563     pub(crate) local_filesets: Vec<usize>,
 564 }
 565
 566 impl SourceRootConfig {
 567     pub(crate) fn partition(&self, vfs: &vfs::Vfs) -> Vec<SourceRoot> {
 568         let _p = profile::span("SourceRootConfig::partition");
 569         self.fsc
 570             .partition(vfs)
 571             .into_iter()
 572             .enumerate()
 573             .map(|(idx, file_set)| {
 574                 let is_local = self.local_filesets.contains(&idx);
 575                 if is_local {
 576                     SourceRoot::new_local(file_set)
 577                 } else {
 578                     SourceRoot::new_library(file_set)
 579                 }
 580             })
 581             .collect()
 582     }
 583 }
 584
 585 /// Load the proc-macros for the given lib path, replacing all expanders whose names are in `dummy_replace`
 586 /// with an identity dummy expander.
 587 pub(crate) fn load_proc_macro(
 588     server: Result<&ProcMacroServer, &str>,
 589     path: &AbsPath,
 590     dummy_replace: &[Box<str>],
 591 ) -> ProcMacroLoadResult {
 592     let res: Result<Vec<_>, String> = (|| {
 593         let dylib = MacroDylib::new(path.to_path_buf())
 594             .map_err(|io| format!("Proc-macro dylib loading failed: {io}"))?;
 595         let server = server.map_err(ToOwned::to_owned)?;
 596         let vec = server.load_dylib(dylib).map_err(|e| format!("{e}"))?;
 597         if vec.is_empty() {
 598             return Err("proc macro library returned no proc macros".to_string());
 599         }
 600         Ok(vec
 601             .into_iter()
 602             .map(|expander| expander_to_proc_macro(expander, dummy_replace))
 603             .collect())
 604     })();
 605     return match res {
 606         Ok(proc_macros) => {
 607             tracing::info!(
 608                 "Loaded proc-macros for {}: {:?}",
 609                 path.display(),
 610                 proc_macros.iter().map(|it| it.name.clone()).collect::<Vec<_>>()
 611             );
 612             Ok(proc_macros)
 613         }
 614         Err(e) => {
 615             tracing::warn!("proc-macro loading for {} failed: {e}", path.display());
 616             Err(e)
 617         }
 618     };
 619
 620     fn expander_to_proc_macro(
 621         expander: proc_macro_api::ProcMacro,
 622         dummy_replace: &[Box<str>],
 623     ) -> ProcMacro {
 624         let name = SmolStr::from(expander.name());
 625         let kind = match expander.kind() {
 626             proc_macro_api::ProcMacroKind::CustomDerive => ProcMacroKind::CustomDerive,
 627             proc_macro_api::ProcMacroKind::FuncLike => ProcMacroKind::FuncLike,
 628             proc_macro_api::ProcMacroKind::Attr => ProcMacroKind::Attr,
 629         };
 630         let expander: Arc<dyn ProcMacroExpander> =
 631             if dummy_replace.iter().any(|replace| &**replace == name) {
 632                 match kind {
 633                     ProcMacroKind::Attr => Arc::new(IdentityExpander),
 634                     _ => Arc::new(EmptyExpander),
 635                 }
 636             } else {
 637                 Arc::new(Expander(expander))
 638             };
 639         ProcMacro { name, kind, expander }
 640     }
 641
 642     #[derive(Debug)]
 643     struct Expander(proc_macro_api::ProcMacro);
 644
 645     impl ProcMacroExpander for Expander {
 646         fn expand(
 647             &self,
 648             subtree: &tt::Subtree,
 649             attrs: Option<&tt::Subtree>,
 650             env: &Env,
 651         ) -> Result<tt::Subtree, ProcMacroExpansionError> {
 652             let env = env.iter().map(|(k, v)| (k.to_string(), v.to_string())).collect();
 653             match self.0.expand(subtree, attrs, env) {
 654                 Ok(Ok(subtree)) => Ok(subtree),
 655                 Ok(Err(err)) => Err(ProcMacroExpansionError::Panic(err.0)),
 656                 Err(err) => Err(ProcMacroExpansionError::System(err.to_string())),
 657             }
 658         }
 659     }
 660
 661     /// Dummy identity expander, used for attribute proc-macros that are deliberately ignored by the user.
 662     #[derive(Debug)]
 663     struct IdentityExpander;
 664
 665     impl ProcMacroExpander for IdentityExpander {
 666         fn expand(
 667             &self,
 668             subtree: &tt::Subtree,
 669             _: Option<&tt::Subtree>,
 670             _: &Env,
 671         ) -> Result<tt::Subtree, ProcMacroExpansionError> {
 672             Ok(subtree.clone())
 673         }
 674     }
 675
 676     /// Empty expander, used for proc-macros that are deliberately ignored by the user.
 677     #[derive(Debug)]
 678     struct EmptyExpander;
 679
 680     impl ProcMacroExpander for EmptyExpander {
 681         fn expand(
 682             &self,
 683             _: &tt::Subtree,
 684             _: Option<&tt::Subtree>,
 685             _: &Env,
 686         ) -> Result<tt::Subtree, ProcMacroExpansionError> {
 687             Ok(tt::Subtree::default())
 688         }
 689     }
 690 }
 691
 692 pub(crate) fn should_refresh_for_change(path: &AbsPath, change_kind: ChangeKind) -> bool {
 693     const IMPLICIT_TARGET_FILES: &[&str] = &["build.rs", "src/main.rs", "src/lib.rs"];
 694     const IMPLICIT_TARGET_DIRS: &[&str] = &["src/bin", "examples", "tests", "benches"];
 695
 696     let file_name = match path.file_name().unwrap_or_default().to_str() {
 697         Some(it) => it,
 698         None => return false,
 699     };
 700
 701     if let "Cargo.toml" | "Cargo.lock" = file_name {
 702         return true;
 703     }
 704     if change_kind == ChangeKind::Modify {
 705         return false;
 706     }
 707
 708     // .cargo/config{.toml}
 709     if path.extension().unwrap_or_default() != "rs" {
 710         let is_cargo_config = matches!(file_name, "config.toml" | "config")
 711             && path.parent().map(|parent| parent.as_ref().ends_with(".cargo")).unwrap_or(false);
 712         return is_cargo_config;
 713     }
 714
 715     if IMPLICIT_TARGET_FILES.iter().any(|it| path.as_ref().ends_with(it)) {
 716         return true;
 717     }
 718     let parent = match path.parent() {
 719         Some(it) => it,
 720         None => return false,
 721     };
 722     if IMPLICIT_TARGET_DIRS.iter().any(|it| parent.as_ref().ends_with(it)) {
 723         return true;
 724     }
 725     if file_name == "main.rs" {
 726         let grand_parent = match parent.parent() {
 727             Some(it) => it,
 728             None => return false,
 729         };
 730         if IMPLICIT_TARGET_DIRS.iter().any(|it| grand_parent.as_ref().ends_with(it)) {
 731             return true;
 732         }
 733     }
 734     false
 735 }