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