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