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         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_hir::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<(Lrc<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_hir::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)
 126                 .map_err(|mut parse_error| parse_error.emit())
 127         })
 128     }
 129
 130     pub fn register_plugins(&self) -> Result<&Query<(ast::Crate, Lrc<LintStore>)>> {
 131         self.register_plugins.compute(|| {
 132             let crate_name = self.crate_name()?.peek().clone();
 133             let krate = self.parse()?.take();
 134
 135             let empty: &(dyn Fn(&Session, &mut LintStore) + Sync + Send) = &|_, _| {};
 136             let (krate, lint_store) = passes::register_plugins(
 137                 self.session(),
 138                 &*self.codegen_backend().metadata_loader(),
 139                 self.compiler.register_lints.as_deref().unwrap_or_else(|| empty),
 140                 krate,
 141                 &crate_name,
 142             )?;
 143
 144             // Compute the dependency graph (in the background). We want to do
 145             // this as early as possible, to give the DepGraph maximum time to
 146             // load before dep_graph() is called, but it also can't happen
 147             // until after rustc_incremental::prepare_session_directory() is
 148             // called, which happens within passes::register_plugins().
 149             self.dep_graph_future().ok();
 150
 151             Ok((krate, Lrc::new(lint_store)))
 152         })
 153     }
 154
 155     pub fn crate_name(&self) -> Result<&Query<String>> {
 156         self.crate_name.compute(|| {
 157             Ok({
 158                 let parse_result = self.parse()?;
 159                 let krate = parse_result.peek();
 160                 // parse `#[crate_name]` even if `--crate-name` was passed, to make sure it matches.
 161                 find_crate_name(self.session(), &krate.attrs, &self.compiler.input)
 162             })
 163         })
 164     }
 165
 166     pub fn expansion(
 167         &self,
 168     ) -> Result<&Query<(Lrc<ast::Crate>, Rc<RefCell<BoxedResolver>>, Lrc<LintStore>)>> {
 169         trace!("expansion");
 170         self.expansion.compute(|| {
 171             let crate_name = self.crate_name()?.peek().clone();
 172             let (krate, lint_store) = self.register_plugins()?.take();
 173             let _timer = self.session().timer("configure_and_expand");
 174             let sess = self.session();
 175             let mut resolver = passes::create_resolver(
 176                 sess.clone(),
 177                 self.codegen_backend().metadata_loader(),
 178                 &krate,
 179                 &crate_name,
 180             );
 181             let krate = resolver.access(|resolver| {
 182                 passes::configure_and_expand(sess, &lint_store, krate, &crate_name, resolver)
 183             })?;
 184             Ok((Lrc::new(krate), Rc::new(RefCell::new(resolver)), lint_store))
 185         })
 186     }
 187
 188     fn dep_graph(&self) -> Result<&Query<DepGraph>> {
 189         self.dep_graph.compute(|| {
 190             let sess = self.session();
 191             let future_opt = self.dep_graph_future()?.take();
 192             let dep_graph = future_opt
 193                 .and_then(|future| {
 194                     let (prev_graph, prev_work_products) =
 195                         sess.time("blocked_on_dep_graph_loading", || future.open().open(sess));
 196
 197                     rustc_incremental::build_dep_graph(sess, prev_graph, prev_work_products)
 198                 })
 199                 .unwrap_or_else(DepGraph::new_disabled);
 200             Ok(dep_graph)
 201         })
 202     }
 203
 204     pub fn prepare_outputs(&self) -> Result<&Query<OutputFilenames>> {
 205         self.prepare_outputs.compute(|| {
 206             let (krate, boxed_resolver, _) = &*self.expansion()?.peek();
 207             let crate_name = self.crate_name()?.peek();
 208             passes::prepare_outputs(
 209                 self.session(),
 210                 self.compiler,
 211                 krate,
 212                 &*boxed_resolver,
 213                 &crate_name,
 214             )
 215         })
 216     }
 217
 218     pub fn global_ctxt(&'tcx self) -> Result<&Query<QueryContext<'tcx>>> {
 219         self.global_ctxt.compute(|| {
 220             let crate_name = self.crate_name()?.peek().clone();
 221             let outputs = self.prepare_outputs()?.peek().clone();
 222             let dep_graph = self.dep_graph()?.peek().clone();
 223             let (krate, resolver, lint_store) = self.expansion()?.take();
 224             Ok(passes::create_global_ctxt(
 225                 self.compiler,
 226                 lint_store,
 227                 krate,
 228                 dep_graph,
 229                 resolver,
 230                 outputs,
 231                 &crate_name,
 232                 &self.queries,
 233                 &self.gcx,
 234                 &self.arena,
 235                 &self.hir_arena,
 236             ))
 237         })
 238     }
 239
 240     pub fn ongoing_codegen(&'tcx self) -> Result<&Query<Box<dyn Any>>> {
 241         self.ongoing_codegen.compute(|| {
 242             let outputs = self.prepare_outputs()?;
 243             self.global_ctxt()?.peek_mut().enter(|tcx| {
 244                 tcx.analysis(()).ok();
 245
 246                 // Don't do code generation if there were any errors
 247                 self.session().compile_status()?;
 248
 249                 // If we have any delayed bugs, for example because we created TyKind::Error earlier,
 250                 // it's likely that codegen will only cause more ICEs, obscuring the original problem
 251                 self.session().diagnostic().flush_delayed();
 252
 253                 // Hook for UI tests.
 254                 Self::check_for_rustc_errors_attr(tcx);
 255
 256                 Ok(passes::start_codegen(&***self.codegen_backend(), tcx, &*outputs.peek()))
 257             })
 258         })
 259     }
 260
 261     /// Check for the `#[rustc_error]` annotation, which forces an error in codegen. This is used
 262     /// to write UI tests that actually test that compilation succeeds without reporting
 263     /// an error.
 264     fn check_for_rustc_errors_attr(tcx: TyCtxt<'_>) {
 265         let Some((def_id, _)) = tcx.entry_fn(()) else { return };
 266         for attr in tcx.get_attrs(def_id, sym::rustc_error) {
 267             match attr.meta_item_list() {
 268                 // Check if there is a `#[rustc_error(delay_span_bug_from_inside_query)]`.
 269                 Some(list)
 270                     if list.iter().any(|list_item| {
 271                         matches!(
 272                             list_item.ident().map(|i| i.name),
 273                             Some(sym::delay_span_bug_from_inside_query)
 274                         )
 275                     }) =>
 276                 {
 277                     tcx.ensure().trigger_delay_span_bug(def_id);
 278                 }
 279
 280                 // Bare `#[rustc_error]`.
 281                 None => {
 282                     tcx.sess.emit_fatal(RustcErrorFatal { span: tcx.def_span(def_id) });
 283                 }
 284
 285                 // Some other attribute.
 286                 Some(_) => {
 287                     tcx.sess.emit_warning(RustcErrorUnexpectedAnnotation {
 288                         span: tcx.def_span(def_id),
 289                     });
 290                 }
 291             }
 292         }
 293     }
 294
 295     pub fn linker(&'tcx self) -> Result<Linker> {
 296         let sess = self.session().clone();
 297         let codegen_backend = self.codegen_backend().clone();
 298
 299         let dep_graph = self.dep_graph()?.peek().clone();
 300         let prepare_outputs = self.prepare_outputs()?.take();
 301         let crate_hash = self.global_ctxt()?.peek_mut().enter(|tcx| tcx.crate_hash(LOCAL_CRATE));
 302         let ongoing_codegen = self.ongoing_codegen()?.take();
 303
 304         Ok(Linker {
 305             sess,
 306             codegen_backend,
 307
 308             dep_graph,
 309             prepare_outputs,
 310             crate_hash,
 311             ongoing_codegen,
 312         })
 313     }
 314 }
 315
 316 pub struct Linker {
 317     // compilation inputs
 318     sess: Lrc<Session>,
 319     codegen_backend: Lrc<Box<dyn CodegenBackend>>,
 320
 321     // compilation outputs
 322     dep_graph: DepGraph,
 323     prepare_outputs: OutputFilenames,
 324     crate_hash: Svh,
 325     ongoing_codegen: Box<dyn Any>,
 326 }
 327
 328 impl Linker {
 329     pub fn link(self) -> Result<()> {
 330         let (codegen_results, work_products) = self.codegen_backend.join_codegen(
 331             self.ongoing_codegen,
 332             &self.sess,
 333             &self.prepare_outputs,
 334         )?;
 335
 336         self.sess.compile_status()?;
 337
 338         let sess = &self.sess;
 339         let dep_graph = self.dep_graph;
 340         sess.time("serialize_work_products", || {
 341             rustc_incremental::save_work_product_index(sess, &dep_graph, work_products)
 342         });
 343
 344         let prof = self.sess.prof.clone();
 345         prof.generic_activity("drop_dep_graph").run(move || drop(dep_graph));
 346
 347         // Now that we won't touch anything in the incremental compilation directory
 348         // any more, we can finalize it (which involves renaming it)
 349         rustc_incremental::finalize_session_directory(&self.sess, self.crate_hash);
 350
 351         if !self
 352             .sess
 353             .opts
 354             .output_types
 355             .keys()
 356             .any(|&i| i == OutputType::Exe || i == OutputType::Metadata)
 357         {
 358             return Ok(());
 359         }
 360
 361         if sess.opts.unstable_opts.no_link {
 362             let encoded = CodegenResults::serialize_rlink(&codegen_results);
 363             let rlink_file = self.prepare_outputs.with_extension(config::RLINK_EXT);
 364             std::fs::write(&rlink_file, encoded)
 365                 .map_err(|error| sess.emit_fatal(FailedWritingFile { path: &rlink_file, error }))?;
 366             return Ok(());
 367         }
 368
 369         let _timer = sess.prof.verbose_generic_activity("link_crate");
 370         self.codegen_backend.link(&self.sess, codegen_results, &self.prepare_outputs)
 371     }
 372 }
 373
 374 impl Compiler {
 375     pub fn enter<F, T>(&self, f: F) -> T
 376     where
 377         F: for<'tcx> FnOnce(&'tcx Queries<'tcx>) -> T,
 378     {
 379         let mut _timer = None;
 380         let queries = Queries::new(self);
 381         let ret = f(&queries);
 382
 383         // NOTE: intentionally does not compute the global context if it hasn't been built yet,
 384         // since that likely means there was a parse error.
 385         if let Some(Ok(gcx)) = &mut *queries.global_ctxt.result.borrow_mut() {
 386             // We assume that no queries are run past here. If there are new queries
 387             // after this point, they'll show up as "<unknown>" in self-profiling data.
 388             {
 389                 let _prof_timer =
 390                     queries.session().prof.generic_activity("self_profile_alloc_query_strings");
 391                 gcx.enter(rustc_query_impl::alloc_self_profile_query_strings);
 392             }
 393
 394             self.session()
 395                 .time("serialize_dep_graph", || gcx.enter(rustc_incremental::save_dep_graph));
 396         }
 397
 398         _timer = Some(self.session().timer("free_global_ctxt"));
 399
 400         ret
 401     }
 402 }