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_serialize::json;
  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         let mut result = self.result.borrow_mut();
  37         if result.is_none() {
  38             *result = Some(f());
  39         }
  40         result.as_ref().unwrap().as_ref().map(|_| self).map_err(|err| *err)
  41     }
  42
  43     /// Takes ownership of the query result. Further attempts to take or peek the query
  44     /// result will panic unless it is generated by calling the `compute` method.
  45     pub fn take(&self) -> T {
  46         self.result.borrow_mut().take().expect("missing query result").unwrap()
  47     }
  48
  49     /// Borrows the query result using the RefCell. Panics if the result is stolen.
  50     pub fn peek(&self) -> Ref<'_, T> {
  51         Ref::map(self.result.borrow(), |r| {
  52             r.as_ref().unwrap().as_ref().expect("missing query result")
  53         })
  54     }
  55
  56     /// Mutably borrows the query result using the RefCell. Panics if the result is stolen.
  57     pub fn peek_mut(&self) -> RefMut<'_, T> {
  58         RefMut::map(self.result.borrow_mut(), |r| {
  59             r.as_mut().unwrap().as_mut().expect("missing query result")
  60         })
  61     }
  62 }
  63
  64 impl<T> Default for Query<T> {
  65     fn default() -> Self {
  66         Query { result: RefCell::new(None) }
  67     }
  68 }
  69
  70 pub struct Queries<'tcx> {
  71     compiler: &'tcx Compiler,
  72     gcx: OnceCell<GlobalCtxt<'tcx>>,
  73     queries: OnceCell<TcxQueries<'tcx>>,
  74
  75     arena: WorkerLocal<Arena<'tcx>>,
  76     hir_arena: WorkerLocal<rustc_ast_lowering::Arena<'tcx>>,
  77
  78     dep_graph_future: Query<Option<DepGraphFuture>>,
  79     parse: Query<ast::Crate>,
  80     crate_name: Query<String>,
  81     register_plugins: Query<(ast::Crate, Lrc<LintStore>)>,
  82     expansion: Query<(Rc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>,
  83     dep_graph: Query<DepGraph>,
  84     prepare_outputs: Query<OutputFilenames>,
  85     global_ctxt: Query<QueryContext<'tcx>>,
  86     ongoing_codegen: Query<Box<dyn Any>>,
  87 }
  88
  89 impl<'tcx> Queries<'tcx> {
  90     pub fn new(compiler: &'tcx Compiler) -> Queries<'tcx> {
  91         Queries {
  92             compiler,
  93             gcx: OnceCell::new(),
  94             queries: OnceCell::new(),
  95             arena: WorkerLocal::new(|_| Arena::default()),
  96             hir_arena: WorkerLocal::new(|_| rustc_ast_lowering::Arena::default()),
  97             dep_graph_future: Default::default(),
  98             parse: Default::default(),
  99             crate_name: Default::default(),
 100             register_plugins: Default::default(),
 101             expansion: Default::default(),
 102             dep_graph: Default::default(),
 103             prepare_outputs: Default::default(),
 104             global_ctxt: Default::default(),
 105             ongoing_codegen: Default::default(),
 106         }
 107     }
 108
 109     fn session(&self) -> &Lrc<Session> {
 110         &self.compiler.sess
 111     }
 112     fn codegen_backend(&self) -> &Lrc<Box<dyn CodegenBackend>> {
 113         self.compiler.codegen_backend()
 114     }
 115
 116     fn dep_graph_future(&self) -> Result<&Query<Option<DepGraphFuture>>> {
 117         self.dep_graph_future.compute(|| {
 118             let sess = self.session();
 119             Ok(sess.opts.build_dep_graph().then(|| rustc_incremental::load_dep_graph(sess)))
 120         })
 121     }
 122
 123     pub fn parse(&self) -> Result<&Query<ast::Crate>> {
 124         self.parse.compute(|| {
 125             passes::parse(self.session(), &self.compiler.input).map_err(|mut parse_error| {
 126                 parse_error.emit();
 127                 ErrorReported
 128             })
 129         })
 130     }
 131
 132     pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, Lrc<LintStore>)>> {
 133         self.register_plugins.compute(|| {
 134             let crate_name = self.crate_name()?.peek().clone();
 135             let krate = self.parse()?.take();
 136
 137             let empty: &(dyn Fn(&Session, &mut LintStore) + Sync + Send) = &|_, _| {};
 138             let (krate, lint_store) = passes::register_plugins(
 139                 self.session(),
 140                 &*self.codegen_backend().metadata_loader(),
 141                 self.compiler.register_lints.as_deref().unwrap_or_else(|| empty),
 142                 krate,
 143                 &crate_name,
 144             )?;
 145
 146             // Compute the dependency graph (in the background). We want to do
 147             // this as early as possible, to give the DepGraph maximum time to
 148             // load before dep_graph() is called, but it also can't happen
 149             // until after rustc_incremental::prepare_session_directory() is
 150             // called, which happens within passes::register_plugins().
 151             self.dep_graph_future().ok();
 152
 153             Ok((krate, Lrc::new(lint_store)))
 154         })
 155     }
 156
 157     pub fn crate_name(&self) -> Result<&Query<String>> {
 158         self.crate_name.compute(|| {
 159             Ok({
 160                 let parse_result = self.parse()?;
 161                 let krate = parse_result.peek();
 162                 // parse `#[crate_name]` even if `--crate-name` was passed, to make sure it matches.
 163                 find_crate_name(self.session(), &krate.attrs, &self.compiler.input)
 164             })
 165         })
 166     }
 167
 168     pub fn expansion(
 169         &self,
 170     ) -> Result<&Query<(Rc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>> {
 171         tracing::trace!("expansion");
 172         self.expansion.compute(|| {
 173             let crate_name = self.crate_name()?.peek().clone();
 174             let (krate, lint_store) = self.register_plugins()?.take();
 175             let _timer = self.session().timer("configure_and_expand");
 176             let sess = self.session();
 177             let mut resolver = passes::create_resolver(
 178                 sess.clone(),
 179                 self.codegen_backend().metadata_loader(),
 180                 &krate,
 181                 &crate_name,
 182             );
 183             let krate = resolver.access(|resolver| {
 184                 passes::configure_and_expand(sess, &lint_store, krate, &crate_name, resolver)
 185             })?;
 186             Ok((Rc::new(krate), Rc::new(RefCell::new(resolver)), lint_store))
 187         })
 188     }
 189
 190     fn dep_graph(&self) -> Result<&Query<DepGraph>> {
 191         self.dep_graph.compute(|| {
 192             let sess = self.session();
 193             let future_opt = self.dep_graph_future()?.take();
 194             let dep_graph = future_opt
 195                 .and_then(|future| {
 196                     let (prev_graph, prev_work_products) =
 197                         sess.time("blocked_on_dep_graph_loading", || future.open().open(sess));
 198
 199                     rustc_incremental::build_dep_graph(sess, prev_graph, prev_work_products)
 200                 })
 201                 .unwrap_or_else(DepGraph::new_disabled);
 202             Ok(dep_graph)
 203         })
 204     }
 205
 206     pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
 207         self.prepare_outputs.compute(|| {
 208             let (krate, boxed_resolver, _) = &*self.expansion()?.peek();
 209             let crate_name = self.crate_name()?.peek();
 210             passes::prepare_outputs(
 211                 self.session(),
 212                 self.compiler,
 213                 krate,
 214                 &*boxed_resolver,
 215                 &crate_name,
 216             )
 217         })
 218     }
 219
 220     pub fn global_ctxt(&'tcx self) -> Result<&Query<QueryContext<'tcx>>> {
 221         self.global_ctxt.compute(|| {
 222             let crate_name = self.crate_name()?.peek().clone();
 223             let outputs = self.prepare_outputs()?.peek().clone();
 224             let dep_graph = self.dep_graph()?.peek().clone();
 225             let (krate, resolver, lint_store) = self.expansion()?.take();
 226             Ok(passes::create_global_ctxt(
 227                 self.compiler,
 228                 lint_store,
 229                 krate,
 230                 dep_graph,
 231                 resolver,
 232                 outputs,
 233                 &crate_name,
 234                 &self.queries,
 235                 &self.gcx,
 236                 &self.arena,
 237                 &self.hir_arena,
 238             ))
 239         })
 240     }
 241
 242     pub fn ongoing_codegen(&'tcx self) -> Result<&Query<Box<dyn Any>>> {
 243         self.ongoing_codegen.compute(|| {
 244             let outputs = self.prepare_outputs()?;
 245             self.global_ctxt()?.peek_mut().enter(|tcx| {
 246                 tcx.analysis(()).ok();
 247
 248                 // Don't do code generation if there were any errors
 249                 self.session().compile_status()?;
 250
 251                 // Hook for UI tests.
 252                 Self::check_for_rustc_errors_attr(tcx);
 253
 254                 Ok(passes::start_codegen(&***self.codegen_backend(), tcx, &*outputs.peek()))
 255             })
 256         })
 257     }
 258
 259     /// Check for the `#[rustc_error]` annotation, which forces an error in codegen. This is used
 260     /// to write UI tests that actually test that compilation succeeds without reporting
 261     /// an error.
 262     fn check_for_rustc_errors_attr(tcx: TyCtxt<'_>) {
 263         let def_id = match tcx.entry_fn(()) {
 264             Some((def_id, _)) => def_id,
 265             _ => return,
 266         };
 267
 268         let attrs = &*tcx.get_attrs(def_id);
 269         let attrs = attrs.iter().filter(|attr| attr.has_name(sym::rustc_error));
 270         for attr in attrs {
 271             match attr.meta_item_list() {
 272                 // Check if there is a `#[rustc_error(delay_span_bug_from_inside_query)]`.
 273                 Some(list)
 274                     if list.iter().any(|list_item| {
 275                         matches!(
 276                             list_item.ident().map(|i| i.name),
 277                             Some(sym::delay_span_bug_from_inside_query)
 278                         )
 279                     }) =>
 280                 {
 281                     tcx.ensure().trigger_delay_span_bug(def_id);
 282                 }
 283
 284                 // Bare `#[rustc_error]`.
 285                 None => {
 286                     tcx.sess.span_fatal(
 287                         tcx.def_span(def_id),
 288                         "fatal error triggered by #[rustc_error]",
 289                     );
 290                 }
 291
 292                 // Some other attribute.
 293                 Some(_) => {
 294                     tcx.sess.span_warn(
 295                         tcx.def_span(def_id),
 296                         "unexpected annotation used with `#[rustc_error(...)]!",
 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 dep_graph = self.dep_graph()?.peek().clone();
 308         let prepare_outputs = self.prepare_outputs()?.take();
 309         let crate_hash = self.global_ctxt()?.peek_mut().enter(|tcx| tcx.crate_hash(LOCAL_CRATE));
 310         let ongoing_codegen = self.ongoing_codegen()?.take();
 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: 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.debugging_opts.no_link {
 370             // FIXME: use a binary format to encode the `.rlink` file
 371             let rlink_data = json::encode(&codegen_results).map_err(|err| {
 372                 sess.fatal(&format!("failed to encode rlink: {}", err));
 373             })?;
 374             let rlink_file = self.prepare_outputs.with_extension(config::RLINK_EXT);
 375             std::fs::write(&rlink_file, rlink_data).map_err(|err| {
 376                 sess.fatal(&format!("failed to write file {}: {}", rlink_file.display(), err));
 377             })?;
 378             return Ok(());
 379         }
 380
 381         let _timer = sess.prof.verbose_generic_activity("link_crate");
 382         self.codegen_backend.link(&self.sess, codegen_results, &self.prepare_outputs)
 383     }
 384 }
 385
 386 impl Compiler {
 387     pub fn enter<F, T>(&self, f: F) -> T
 388     where
 389         F: for<'tcx> FnOnce(&'tcx Queries<'tcx>) -> T,
 390     {
 391         let mut _timer = None;
 392         let queries = Queries::new(self);
 393         let ret = f(&queries);
 394
 395         // NOTE: intentionally does not compute the global context if it hasn't been built yet,
 396         // since that likely means there was a parse error.
 397         if let Some(Ok(gcx)) = &mut *queries.global_ctxt.result.borrow_mut() {
 398             // We assume that no queries are run past here. If there are new queries
 399             // after this point, they'll show up as "<unknown>" in self-profiling data.
 400             {
 401                 let _prof_timer =
 402                     queries.session().prof.generic_activity("self_profile_alloc_query_strings");
 403                 gcx.enter(rustc_query_impl::alloc_self_profile_query_strings);
 404             }
 405
 406             if self.session().opts.debugging_opts.query_stats {
 407                 gcx.enter(rustc_query_impl::print_stats);
 408             }
 409
 410             self.session()
 411                 .time("serialize_dep_graph", || gcx.enter(rustc_incremental::save_dep_graph));
 412         }
 413
 414         _timer = Some(self.session().timer("free_global_ctxt"));
 415
 416         ret
 417     }
 418 }