compiler/rustc_interface/src/queries.rs

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