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 use std::sync::Arc;
  24
  25 /// Represent the result of a query.
  26 ///
  27 /// This result can be stolen with the [`take`] method and generated with the [`compute`] method.
  28 ///
  29 /// [`take`]: Self::take
  30 /// [`compute`]: Self::compute
  31 pub struct Query<T> {
  32     result: RefCell<Option<Result<T>>>,
  33 }
  34
  35 impl<T> Query<T> {
  36     fn compute<F: FnOnce() -> Result<T>>(&self, f: F) -> Result<&Query<T>> {
  37         self.result.borrow_mut().get_or_insert_with(f).as_ref().map(|_| self).map_err(|&err| err)
  38     }
  39
  40     /// Takes ownership of the query result. Further attempts to take or peek the query
  41     /// result will panic unless it is generated by calling the `compute` method.
  42     pub fn take(&self) -> T {
  43         self.result.borrow_mut().take().expect("missing query result").unwrap()
  44     }
  45
  46     /// Borrows the query result using the RefCell. Panics if the result is stolen.
  47     pub fn peek(&self) -> Ref<'_, T> {
  48         Ref::map(self.result.borrow(), |r| {
  49             r.as_ref().unwrap().as_ref().expect("missing query result")
  50         })
  51     }
  52
  53     /// Mutably borrows the query result using the RefCell. Panics if the result is stolen.
  54     pub fn peek_mut(&self) -> RefMut<'_, T> {
  55         RefMut::map(self.result.borrow_mut(), |r| {
  56             r.as_mut().unwrap().as_mut().expect("missing query result")
  57         })
  58     }
  59 }
  60
  61 impl<T> Default for Query<T> {
  62     fn default() -> Self {
  63         Query { result: RefCell::new(None) }
  64     }
  65 }
  66
  67 pub struct Queries<'tcx> {
  68     compiler: &'tcx Compiler,
  69     gcx: OnceCell<GlobalCtxt<'tcx>>,
  70     queries: OnceCell<TcxQueries<'tcx>>,
  71
  72     arena: WorkerLocal<Arena<'tcx>>,
  73     hir_arena: WorkerLocal<rustc_hir::Arena<'tcx>>,
  74
  75     dep_graph_future: Query<Option<DepGraphFuture>>,
  76     parse: Query<ast::Crate>,
  77     crate_name: Query<String>,
  78     register_plugins: Query<(ast::Crate, Lrc<LintStore>)>,
  79     expansion: Query<(Lrc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>,
  80     dep_graph: Query<DepGraph>,
  81     prepare_outputs: Query<OutputFilenames>,
  82     global_ctxt: Query<QueryContext<'tcx>>,
  83     ongoing_codegen: Query<Box<dyn Any>>,
  84 }
  85
  86 impl<'tcx> Queries<'tcx> {
  87     pub fn new(compiler: &'tcx Compiler) -> Queries<'tcx> {
  88         Queries {
  89             compiler,
  90             gcx: OnceCell::new(),
  91             queries: OnceCell::new(),
  92             arena: WorkerLocal::new(|_| Arena::default()),
  93             hir_arena: WorkerLocal::new(|_| rustc_hir::Arena::default()),
  94             dep_graph_future: Default::default(),
  95             parse: Default::default(),
  96             crate_name: Default::default(),
  97             register_plugins: Default::default(),
  98             expansion: Default::default(),
  99             dep_graph: Default::default(),
 100             prepare_outputs: Default::default(),
 101             global_ctxt: Default::default(),
 102             ongoing_codegen: Default::default(),
 103         }
 104     }
 105
 106     fn session(&self) -> &Lrc<Session> {
 107         &self.compiler.sess
 108     }
 109     fn codegen_backend(&self) -> &Lrc<Box<dyn CodegenBackend>> {
 110         self.compiler.codegen_backend()
 111     }
 112
 113     fn dep_graph_future(&self) -> Result<&Query<Option<DepGraphFuture>>> {
 114         self.dep_graph_future.compute(|| {
 115             let sess = self.session();
 116             Ok(sess.opts.build_dep_graph().then(|| rustc_incremental::load_dep_graph(sess)))
 117         })
 118     }
 119
 120     pub fn parse(&self) -> Result<&Query<ast::Crate>> {
 121         self.parse.compute(|| {
 122             passes::parse(self.session(), &self.compiler.input)
 123                 .map_err(|mut parse_error| parse_error.emit())
 124         })
 125     }
 126
 127     pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, Lrc<LintStore>)>> {
 128         self.register_plugins.compute(|| {
 129             let crate_name = self.crate_name()?.peek().clone();
 130             let krate = self.parse()?.take();
 131
 132             let empty: &(dyn Fn(&Session, &mut LintStore) + Sync + Send) = &|_, _| {};
 133             let (krate, lint_store) = passes::register_plugins(
 134                 self.session(),
 135                 &*self.codegen_backend().metadata_loader(),
 136                 self.compiler.register_lints.as_deref().unwrap_or_else(|| empty),
 137                 krate,
 138                 &crate_name,
 139             )?;
 140
 141             // Compute the dependency graph (in the background). We want to do
 142             // this as early as possible, to give the DepGraph maximum time to
 143             // load before dep_graph() is called, but it also can't happen
 144             // until after rustc_incremental::prepare_session_directory() is
 145             // called, which happens within passes::register_plugins().
 146             self.dep_graph_future().ok();
 147
 148             Ok((krate, Lrc::new(lint_store)))
 149         })
 150     }
 151
 152     pub fn crate_name(&self) -> Result<&Query<String>> {
 153         self.crate_name.compute(|| {
 154             Ok({
 155                 let parse_result = self.parse()?;
 156                 let krate = parse_result.peek();
 157                 // parse `#[crate_name]` even if `--crate-name` was passed, to make sure it matches.
 158                 find_crate_name(self.session(), &krate.attrs, &self.compiler.input)
 159             })
 160         })
 161     }
 162
 163     pub fn expansion(
 164         &self,
 165     ) -> Result<&Query<(Lrc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>> {
 166         trace!("expansion");
 167         self.expansion.compute(|| {
 168             let crate_name = self.crate_name()?.peek().clone();
 169             let (krate, lint_store) = self.register_plugins()?.take();
 170             let _timer = self.session().timer("configure_and_expand");
 171             let sess = self.session();
 172             let mut resolver = passes::create_resolver(
 173                 sess.clone(),
 174                 self.codegen_backend().metadata_loader(),
 175                 &krate,
 176                 &crate_name,
 177             );
 178             let krate = resolver.access(|resolver| {
 179                 passes::configure_and_expand(sess, &lint_store, krate, &crate_name, resolver)
 180             })?;
 181             Ok((Lrc::new(krate), Rc::new(RefCell::new(resolver)), lint_store))
 182         })
 183     }
 184
 185     fn dep_graph(&self) -> Result<&Query<DepGraph>> {
 186         self.dep_graph.compute(|| {
 187             let sess = self.session();
 188             let future_opt = self.dep_graph_future()?.take();
 189             let dep_graph = future_opt
 190                 .and_then(|future| {
 191                     let (prev_graph, prev_work_products) =
 192                         sess.time("blocked_on_dep_graph_loading", || future.open().open(sess));
 193
 194                     rustc_incremental::build_dep_graph(sess, prev_graph, prev_work_products)
 195                 })
 196                 .unwrap_or_else(DepGraph::new_disabled);
 197             Ok(dep_graph)
 198         })
 199     }
 200
 201     pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
 202         self.prepare_outputs.compute(|| {
 203             let (krate, boxed_resolver, _) = &*self.expansion()?.peek();
 204             let crate_name = self.crate_name()?.peek();
 205             passes::prepare_outputs(
 206                 self.session(),
 207                 self.compiler,
 208                 krate,
 209                 &*boxed_resolver,
 210                 &crate_name,
 211             )
 212         })
 213     }
 214
 215     pub fn global_ctxt(&'tcx self) -> Result<&Query<QueryContext<'tcx>>> {
 216         self.global_ctxt.compute(|| {
 217             let crate_name = self.crate_name()?.peek().clone();
 218             let outputs = self.prepare_outputs()?.take();
 219             let dep_graph = self.dep_graph()?.peek().clone();
 220             let (krate, resolver, lint_store) = self.expansion()?.take();
 221             Ok(passes::create_global_ctxt(
 222                 self.compiler,
 223                 lint_store,
 224                 krate,
 225                 dep_graph,
 226                 resolver,
 227                 outputs,
 228                 &crate_name,
 229                 &self.queries,
 230                 &self.gcx,
 231                 &self.arena,
 232                 &self.hir_arena,
 233             ))
 234         })
 235     }
 236
 237     pub fn ongoing_codegen(&'tcx self) -> Result<&Query<Box<dyn Any>>> {
 238         self.ongoing_codegen.compute(|| {
 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))
 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 (crate_hash, prepare_outputs) = self
 297             .global_ctxt()?
 298             .peek_mut()
 299             .enter(|tcx| (tcx.crate_hash(LOCAL_CRATE), tcx.output_filenames(()).clone()));
 300         let ongoing_codegen = self.ongoing_codegen()?.take();
 301
 302         Ok(Linker {
 303             sess,
 304             codegen_backend,
 305
 306             dep_graph,
 307             prepare_outputs,
 308             crate_hash,
 309             ongoing_codegen,
 310         })
 311     }
 312 }
 313
 314 pub struct Linker {
 315     // compilation inputs
 316     sess: Lrc<Session>,
 317     codegen_backend: Lrc<Box<dyn CodegenBackend>>,
 318
 319     // compilation outputs
 320     dep_graph: DepGraph,
 321     prepare_outputs: Arc<OutputFilenames>,
 322     crate_hash: Svh,
 323     ongoing_codegen: Box<dyn Any>,
 324 }
 325
 326 impl Linker {
 327     pub fn link(self) -> Result<()> {
 328         let (codegen_results, work_products) = self.codegen_backend.join_codegen(
 329             self.ongoing_codegen,
 330             &self.sess,
 331             &self.prepare_outputs,
 332         )?;
 333
 334         self.sess.compile_status()?;
 335
 336         let sess = &self.sess;
 337         let dep_graph = self.dep_graph;
 338         sess.time("serialize_work_products", || {
 339             rustc_incremental::save_work_product_index(sess, &dep_graph, work_products)
 340         });
 341
 342         let prof = self.sess.prof.clone();
 343         prof.generic_activity("drop_dep_graph").run(move || drop(dep_graph));
 344
 345         // Now that we won't touch anything in the incremental compilation directory
 346         // any more, we can finalize it (which involves renaming it)
 347         rustc_incremental::finalize_session_directory(&self.sess, self.crate_hash);
 348
 349         if !self
 350             .sess
 351             .opts
 352             .output_types
 353             .keys()
 354             .any(|&i| i == OutputType::Exe || i == OutputType::Metadata)
 355         {
 356             return Ok(());
 357         }
 358
 359         if sess.opts.unstable_opts.no_link {
 360             let encoded = CodegenResults::serialize_rlink(&codegen_results);
 361             let rlink_file = self.prepare_outputs.with_extension(config::RLINK_EXT);
 362             std::fs::write(&rlink_file, encoded)
 363                 .map_err(|error| sess.emit_fatal(FailedWritingFile { path: &rlink_file, error }))?;
 364             return Ok(());
 365         }
 366
 367         let _timer = sess.prof.verbose_generic_activity("link_crate");
 368         self.codegen_backend.link(&self.sess, codegen_results, &self.prepare_outputs)
 369     }
 370 }
 371
 372 impl Compiler {
 373     pub fn enter<F, T>(&self, f: F) -> T
 374     where
 375         F: for<'tcx> FnOnce(&'tcx Queries<'tcx>) -> T,
 376     {
 377         let mut _timer = None;
 378         let queries = Queries::new(self);
 379         let ret = f(&queries);
 380
 381         // NOTE: intentionally does not compute the global context if it hasn't been built yet,
 382         // since that likely means there was a parse error.
 383         if let Some(Ok(gcx)) = &mut *queries.global_ctxt.result.borrow_mut() {
 384             // We assume that no queries are run past here. If there are new queries
 385             // after this point, they'll show up as "<unknown>" in self-profiling data.
 386             {
 387                 let _prof_timer =
 388                     queries.session().prof.generic_activity("self_profile_alloc_query_strings");
 389                 gcx.enter(rustc_query_impl::alloc_self_profile_query_strings);
 390             }
 391
 392             self.session()
 393                 .time("serialize_dep_graph", || gcx.enter(rustc_incremental::save_dep_graph));
 394         }
 395
 396         _timer = Some(self.session().timer("free_global_ctxt"));
 397
 398         ret
 399     }
 400 }