compiler/rustc_interface/src/queries.rs

   1 use crate::errors::{FailedWritingFile, RustcErrorFatal, RustcErrorUnexpectedAnnotation};
   2 use crate::interface::{Compiler, Result};
   3 use crate::passes::{self, BoxedResolver, QueryContext};
   4
   5 use rustc_ast as ast;
   6 use rustc_codegen_ssa::traits::CodegenBackend;
   7 use rustc_codegen_ssa::CodegenResults;
   8 use rustc_data_structures::steal::Steal;
   9 use rustc_data_structures::svh::Svh;
  10 use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal};
  11 use rustc_hir::def_id::LOCAL_CRATE;
  12 use rustc_incremental::DepGraphFuture;
  13 use rustc_lint::LintStore;
  14 use rustc_middle::arena::Arena;
  15 use rustc_middle::dep_graph::DepGraph;
  16 use rustc_middle::ty::{GlobalCtxt, TyCtxt};
  17 use rustc_query_impl::Queries as TcxQueries;
  18 use rustc_session::config::{self, OutputFilenames, OutputType};
  19 use rustc_session::{output::find_crate_name, Session};
  20 use rustc_span::symbol::sym;
  21 use rustc_span::Symbol;
  22 use std::any::Any;
  23 use std::cell::{RefCell, RefMut};
  24 use std::rc::Rc;
  25 use std::sync::Arc;
  26
  27 /// Represent the result of a query.
  28 ///
  29 /// This result can be stolen once with the [`steal`] method and generated with the [`compute`] method.
  30 ///
  31 /// [`steal`]: Steal::steal
  32 /// [`compute`]: Self::compute
  33 pub struct Query<T> {
  34     /// `None` means no value has been computed yet.
  35     result: RefCell<Option<Result<Steal<T>>>>,
  36 }
  37
  38 impl<T> Query<T> {
  39     fn compute<F: FnOnce() -> Result<T>>(&self, f: F) -> Result<QueryResult<'_, T>> {
  40         RefMut::filter_map(
  41             self.result.borrow_mut(),
  42             |r: &mut Option<Result<Steal<T>>>| -> Option<&mut Steal<T>> {
  43                 r.get_or_insert_with(|| f().map(Steal::new)).as_mut().ok()
  44             },
  45         )
  46         .map_err(|r| *r.as_ref().unwrap().as_ref().map(|_| ()).unwrap_err())
  47         .map(QueryResult)
  48     }
  49 }
  50
  51 pub struct QueryResult<'a, T>(RefMut<'a, Steal<T>>);
  52
  53 impl<'a, T> std::ops::Deref for QueryResult<'a, T> {
  54     type Target = RefMut<'a, Steal<T>>;
  55
  56     fn deref(&self) -> &Self::Target {
  57         &self.0
  58     }
  59 }
  60
  61 impl<'a, T> std::ops::DerefMut for QueryResult<'a, T> {
  62     fn deref_mut(&mut self) -> &mut Self::Target {
  63         &mut self.0
  64     }
  65 }
  66
  67 impl<'a, 'tcx> QueryResult<'a, QueryContext<'tcx>> {
  68     pub fn enter<T>(mut self, f: impl FnOnce(TyCtxt<'tcx>) -> T) -> T {
  69         (*self.0).get_mut().enter(f)
  70     }
  71 }
  72
  73 impl<T> Default for Query<T> {
  74     fn default() -> Self {
  75         Query { result: RefCell::new(None) }
  76     }
  77 }
  78
  79 pub struct Queries<'tcx> {
  80     compiler: &'tcx Compiler,
  81     gcx: OnceCell<GlobalCtxt<'tcx>>,
  82     queries: OnceCell<TcxQueries<'tcx>>,
  83
  84     arena: WorkerLocal<Arena<'tcx>>,
  85     hir_arena: WorkerLocal<rustc_hir::Arena<'tcx>>,
  86
  87     dep_graph_future: Query<Option<DepGraphFuture>>,
  88     parse: Query<ast::Crate>,
  89     crate_name: Query<Symbol>,
  90     register_plugins: Query<(ast::Crate, Lrc<LintStore>)>,
  91     expansion: Query<(Lrc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>,
  92     dep_graph: Query<DepGraph>,
  93     prepare_outputs: Query<OutputFilenames>,
  94     global_ctxt: Query<QueryContext<'tcx>>,
  95     ongoing_codegen: Query<Box<dyn Any>>,
  96 }
  97
  98 impl<'tcx> Queries<'tcx> {
  99     pub fn new(compiler: &'tcx Compiler) -> Queries<'tcx> {
 100         Queries {
 101             compiler,
 102             gcx: OnceCell::new(),
 103             queries: OnceCell::new(),
 104             arena: WorkerLocal::new(|_| Arena::default()),
 105             hir_arena: WorkerLocal::new(|_| rustc_hir::Arena::default()),
 106             dep_graph_future: Default::default(),
 107             parse: Default::default(),
 108             crate_name: Default::default(),
 109             register_plugins: Default::default(),
 110             expansion: Default::default(),
 111             dep_graph: Default::default(),
 112             prepare_outputs: Default::default(),
 113             global_ctxt: Default::default(),
 114             ongoing_codegen: Default::default(),
 115         }
 116     }
 117
 118     fn session(&self) -> &Lrc<Session> {
 119         &self.compiler.sess
 120     }
 121     fn codegen_backend(&self) -> &Lrc<Box<dyn CodegenBackend>> {
 122         self.compiler.codegen_backend()
 123     }
 124
 125     fn dep_graph_future(&self) -> Result<QueryResult<'_, Option<DepGraphFuture>>> {
 126         self.dep_graph_future.compute(|| {
 127             let sess = self.session();
 128             Ok(sess.opts.build_dep_graph().then(|| rustc_incremental::load_dep_graph(sess)))
 129         })
 130     }
 131
 132     pub fn parse(&self) -> Result<QueryResult<'_, ast::Crate>> {
 133         self.parse.compute(|| {
 134             passes::parse(self.session(), &self.compiler.input)
 135                 .map_err(|mut parse_error| parse_error.emit())
 136         })
 137     }
 138
 139     pub fn register_plugins(&self) -> Result<QueryResult<'_, (ast::Crate, Lrc<LintStore>)>> {
 140         self.register_plugins.compute(|| {
 141             let crate_name = *self.crate_name()?.borrow();
 142             let krate = self.parse()?.steal();
 143
 144             let empty: &(dyn Fn(&Session, &mut LintStore) + Sync + Send) = &|_, _| {};
 145             let (krate, lint_store) = passes::register_plugins(
 146                 self.session(),
 147                 &*self.codegen_backend().metadata_loader(),
 148                 self.compiler.register_lints.as_deref().unwrap_or_else(|| empty),
 149                 krate,
 150                 crate_name,
 151             )?;
 152
 153             // Compute the dependency graph (in the background). We want to do
 154             // this as early as possible, to give the DepGraph maximum time to
 155             // load before dep_graph() is called, but it also can't happen
 156             // until after rustc_incremental::prepare_session_directory() is
 157             // called, which happens within passes::register_plugins().
 158             self.dep_graph_future().ok();
 159
 160             Ok((krate, Lrc::new(lint_store)))
 161         })
 162     }
 163
 164     pub fn crate_name(&self) -> Result<QueryResult<'_, Symbol>> {
 165         self.crate_name.compute(|| {
 166             Ok({
 167                 let parse_result = self.parse()?;
 168                 let krate = parse_result.borrow();
 169                 // parse `#[crate_name]` even if `--crate-name` was passed, to make sure it matches.
 170                 find_crate_name(self.session(), &krate.attrs, &self.compiler.input)
 171             })
 172         })
 173     }
 174
 175     pub fn expansion(
 176         &self,
 177     ) -> Result<QueryResult<'_, (Lrc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>>
 178     {
 179         trace!("expansion");
 180         self.expansion.compute(|| {
 181             let crate_name = *self.crate_name()?.borrow();
 182             let (krate, lint_store) = self.register_plugins()?.steal();
 183             let _timer = self.session().timer("configure_and_expand");
 184             let sess = self.session();
 185             let mut resolver = passes::create_resolver(
 186                 sess.clone(),
 187                 self.codegen_backend().metadata_loader(),
 188                 &krate,
 189                 crate_name,
 190             );
 191             let krate = resolver.access(|resolver| {
 192                 passes::configure_and_expand(sess, &lint_store, krate, crate_name, resolver)
 193             })?;
 194             Ok((Lrc::new(krate), Rc::new(RefCell::new(resolver)), lint_store))
 195         })
 196     }
 197
 198     fn dep_graph(&self) -> Result<QueryResult<'_, DepGraph>> {
 199         self.dep_graph.compute(|| {
 200             let sess = self.session();
 201             let future_opt = self.dep_graph_future()?.steal();
 202             let dep_graph = future_opt
 203                 .and_then(|future| {
 204                     let (prev_graph, prev_work_products) =
 205                         sess.time("blocked_on_dep_graph_loading", || future.open().open(sess));
 206
 207                     rustc_incremental::build_dep_graph(sess, prev_graph, prev_work_products)
 208                 })
 209                 .unwrap_or_else(DepGraph::new_disabled);
 210             Ok(dep_graph)
 211         })
 212     }
 213
 214     pub fn prepare_outputs(&self) -> Result<QueryResult<'_, OutputFilenames>> {
 215         self.prepare_outputs.compute(|| {
 216             let expansion = self.expansion()?;
 217             let (krate, boxed_resolver, _) = &*expansion.borrow();
 218             let crate_name = *self.crate_name()?.borrow();
 219             passes::prepare_outputs(
 220                 self.session(),
 221                 self.compiler,
 222                 krate,
 223                 &*boxed_resolver,
 224                 crate_name,
 225             )
 226         })
 227     }
 228
 229     pub fn global_ctxt(&'tcx self) -> Result<QueryResult<'_, QueryContext<'tcx>>> {
 230         self.global_ctxt.compute(|| {
 231             let crate_name = *self.crate_name()?.borrow();
 232             let outputs = self.prepare_outputs()?.steal();
 233             let dep_graph = self.dep_graph()?.borrow().clone();
 234             let (krate, resolver, lint_store) = self.expansion()?.steal();
 235             Ok(passes::create_global_ctxt(
 236                 self.compiler,
 237                 lint_store,
 238                 krate,
 239                 dep_graph,
 240                 resolver,
 241                 outputs,
 242                 crate_name,
 243                 &self.queries,
 244                 &self.gcx,
 245                 &self.arena,
 246                 &self.hir_arena,
 247             ))
 248         })
 249     }
 250
 251     pub fn ongoing_codegen(&'tcx self) -> Result<QueryResult<'_, Box<dyn Any>>> {
 252         self.ongoing_codegen.compute(|| {
 253             self.global_ctxt()?.enter(|tcx| {
 254                 tcx.analysis(()).ok();
 255
 256                 // Don't do code generation if there were any errors
 257                 self.session().compile_status()?;
 258
 259                 // If we have any delayed bugs, for example because we created TyKind::Error earlier,
 260                 // it's likely that codegen will only cause more ICEs, obscuring the original problem
 261                 self.session().diagnostic().flush_delayed();
 262
 263                 // Hook for UI tests.
 264                 Self::check_for_rustc_errors_attr(tcx);
 265
 266                 Ok(passes::start_codegen(&***self.codegen_backend(), tcx))
 267             })
 268         })
 269     }
 270
 271     /// Check for the `#[rustc_error]` annotation, which forces an error in codegen. This is used
 272     /// to write UI tests that actually test that compilation succeeds without reporting
 273     /// an error.
 274     fn check_for_rustc_errors_attr(tcx: TyCtxt<'_>) {
 275         let Some((def_id, _)) = tcx.entry_fn(()) else { return };
 276         for attr in tcx.get_attrs(def_id, sym::rustc_error) {
 277             match attr.meta_item_list() {
 278                 // Check if there is a `#[rustc_error(delay_span_bug_from_inside_query)]`.
 279                 Some(list)
 280                     if list.iter().any(|list_item| {
 281                         matches!(
 282                             list_item.ident().map(|i| i.name),
 283                             Some(sym::delay_span_bug_from_inside_query)
 284                         )
 285                     }) =>
 286                 {
 287                     tcx.ensure().trigger_delay_span_bug(def_id);
 288                 }
 289
 290                 // Bare `#[rustc_error]`.
 291                 None => {
 292                     tcx.sess.emit_fatal(RustcErrorFatal { span: tcx.def_span(def_id) });
 293                 }
 294
 295                 // Some other attribute.
 296                 Some(_) => {
 297                     tcx.sess.emit_warning(RustcErrorUnexpectedAnnotation {
 298                         span: tcx.def_span(def_id),
 299                     });
 300                 }
 301             }
 302         }
 303     }
 304
 305     pub fn linker(&'tcx self) -> Result<Linker> {
 306         let sess = self.session().clone();
 307         let codegen_backend = self.codegen_backend().clone();
 308
 309         let (crate_hash, prepare_outputs, dep_graph) = self.global_ctxt()?.enter(|tcx| {
 310             (tcx.crate_hash(LOCAL_CRATE), tcx.output_filenames(()).clone(), tcx.dep_graph.clone())
 311         });
 312         let ongoing_codegen = self.ongoing_codegen()?.steal();
 313
 314         Ok(Linker {
 315             sess,
 316             codegen_backend,
 317
 318             dep_graph,
 319             prepare_outputs,
 320             crate_hash,
 321             ongoing_codegen,
 322         })
 323     }
 324 }
 325
 326 pub struct Linker {
 327     // compilation inputs
 328     sess: Lrc<Session>,
 329     codegen_backend: Lrc<Box<dyn CodegenBackend>>,
 330
 331     // compilation outputs
 332     dep_graph: DepGraph,
 333     prepare_outputs: Arc<OutputFilenames>,
 334     crate_hash: Svh,
 335     ongoing_codegen: Box<dyn Any>,
 336 }
 337
 338 impl Linker {
 339     pub fn link(self) -> Result<()> {
 340         let (codegen_results, work_products) = self.codegen_backend.join_codegen(
 341             self.ongoing_codegen,
 342             &self.sess,
 343             &self.prepare_outputs,
 344         )?;
 345
 346         self.sess.compile_status()?;
 347
 348         let sess = &self.sess;
 349         let dep_graph = self.dep_graph;
 350         sess.time("serialize_work_products", || {
 351             rustc_incremental::save_work_product_index(sess, &dep_graph, work_products)
 352         });
 353
 354         let prof = self.sess.prof.clone();
 355         prof.generic_activity("drop_dep_graph").run(move || drop(dep_graph));
 356
 357         // Now that we won't touch anything in the incremental compilation directory
 358         // any more, we can finalize it (which involves renaming it)
 359         rustc_incremental::finalize_session_directory(&self.sess, self.crate_hash);
 360
 361         if !self
 362             .sess
 363             .opts
 364             .output_types
 365             .keys()
 366             .any(|&i| i == OutputType::Exe || i == OutputType::Metadata)
 367         {
 368             return Ok(());
 369         }
 370
 371         if sess.opts.unstable_opts.no_link {
 372             let encoded = CodegenResults::serialize_rlink(&codegen_results);
 373             let rlink_file = self.prepare_outputs.with_extension(config::RLINK_EXT);
 374             std::fs::write(&rlink_file, encoded)
 375                 .map_err(|error| sess.emit_fatal(FailedWritingFile { path: &rlink_file, error }))?;
 376             return Ok(());
 377         }
 378
 379         let _timer = sess.prof.verbose_generic_activity("link_crate");
 380         self.codegen_backend.link(&self.sess, codegen_results, &self.prepare_outputs)
 381     }
 382 }
 383
 384 impl Compiler {
 385     pub fn enter<F, T>(&self, f: F) -> T
 386     where
 387         F: for<'tcx> FnOnce(&'tcx Queries<'tcx>) -> T,
 388     {
 389         let mut _timer = None;
 390         let queries = Queries::new(self);
 391         let ret = f(&queries);
 392
 393         // NOTE: intentionally does not compute the global context if it hasn't been built yet,
 394         // since that likely means there was a parse error.
 395         if let Some(Ok(gcx)) = &mut *queries.global_ctxt.result.borrow_mut() {
 396             let gcx = gcx.get_mut();
 397             // We assume that no queries are run past here. If there are new queries
 398             // after this point, they'll show up as "<unknown>" in self-profiling data.
 399             {
 400                 let _prof_timer =
 401                     queries.session().prof.generic_activity("self_profile_alloc_query_strings");
 402                 gcx.enter(rustc_query_impl::alloc_self_profile_query_strings);
 403             }
 404
 405             self.session()
 406                 .time("serialize_dep_graph", || gcx.enter(rustc_incremental::save_dep_graph));
 407         }
 408
 409         _timer = Some(self.session().timer("free_global_ctxt"));
 410
 411         ret
 412     }
 413 }