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