src/librustdoc/core.rs

   1 use rustc_ast::NodeId;
   2 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
   3 use rustc_data_structures::sync::{self, Lrc};
   4 use rustc_data_structures::unord::UnordSet;
   5 use rustc_errors::emitter::{Emitter, EmitterWriter};
   6 use rustc_errors::json::JsonEmitter;
   7 use rustc_feature::UnstableFeatures;
   8 use rustc_hir::def::{Namespace, Res};
   9 use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId};
  10 use rustc_hir::intravisit::{self, Visitor};
  11 use rustc_hir::{HirId, Path, TraitCandidate};
  12 use rustc_interface::interface;
  13 use rustc_middle::hir::nested_filter;
  14 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
  15 use rustc_resolve as resolve;
  16 use rustc_session::config::{self, CrateType, ErrorOutputType};
  17 use rustc_session::lint;
  18 use rustc_session::Session;
  19 use rustc_span::symbol::sym;
  20 use rustc_span::{source_map, Span, Symbol};
  21
  22 use std::cell::RefCell;
  23 use std::mem;
  24 use std::rc::Rc;
  25 use std::sync::LazyLock;
  26
  27 use crate::clean::inline::build_external_trait;
  28 use crate::clean::{self, ItemId};
  29 use crate::config::{Options as RustdocOptions, OutputFormat, RenderOptions};
  30 use crate::formats::cache::Cache;
  31 use crate::passes::collect_intra_doc_links::PreprocessedMarkdownLink;
  32 use crate::passes::{self, Condition::*};
  33
  34 pub(crate) use rustc_session::config::{Input, Options, UnstableOptions};
  35
  36 pub(crate) struct ResolverCaches {
  37     pub(crate) markdown_links: Option<FxHashMap<String, Vec<PreprocessedMarkdownLink>>>,
  38     pub(crate) doc_link_resolutions: FxHashMap<(Symbol, Namespace, DefId), Option<Res<NodeId>>>,
  39     /// Traits in scope for a given module.
  40     /// See `collect_intra_doc_links::traits_implemented_by` for more details.
  41     pub(crate) traits_in_scope: DefIdMap<Vec<TraitCandidate>>,
  42     pub(crate) all_trait_impls: Option<Vec<DefId>>,
  43     pub(crate) all_macro_rules: FxHashMap<Symbol, Res<NodeId>>,
  44 }
  45
  46 pub(crate) struct DocContext<'tcx> {
  47     pub(crate) tcx: TyCtxt<'tcx>,
  48     /// Name resolver. Used for intra-doc links.
  49     ///
  50     /// The `Rc<RefCell<...>>` wrapping is needed because that is what's returned by
  51     /// [`rustc_interface::Queries::expansion()`].
  52     // FIXME: see if we can get rid of this RefCell somehow
  53     pub(crate) resolver: Rc<RefCell<interface::BoxedResolver>>,
  54     pub(crate) resolver_caches: ResolverCaches,
  55     /// Used for normalization.
  56     ///
  57     /// Most of this logic is copied from rustc_lint::late.
  58     pub(crate) param_env: ParamEnv<'tcx>,
  59     /// Later on moved through `clean::Crate` into `cache`
  60     pub(crate) external_traits: Rc<RefCell<FxHashMap<DefId, clean::Trait>>>,
  61     /// Used while populating `external_traits` to ensure we don't process the same trait twice at
  62     /// the same time.
  63     pub(crate) active_extern_traits: FxHashSet<DefId>,
  64     // The current set of parameter substitutions,
  65     // for expanding type aliases at the HIR level:
  66     /// Table `DefId` of type, lifetime, or const parameter -> substituted type, lifetime, or const
  67     pub(crate) substs: FxHashMap<DefId, clean::SubstParam>,
  68     /// Table synthetic type parameter for `impl Trait` in argument position -> bounds
  69     pub(crate) impl_trait_bounds: FxHashMap<ImplTraitParam, Vec<clean::GenericBound>>,
  70     /// Auto-trait or blanket impls processed so far, as `(self_ty, trait_def_id)`.
  71     // FIXME(eddyb) make this a `ty::TraitRef<'tcx>` set.
  72     pub(crate) generated_synthetics: FxHashSet<(Ty<'tcx>, DefId)>,
  73     pub(crate) auto_traits: Vec<DefId>,
  74     /// The options given to rustdoc that could be relevant to a pass.
  75     pub(crate) render_options: RenderOptions,
  76     /// This same cache is used throughout rustdoc, including in [`crate::html::render`].
  77     pub(crate) cache: Cache,
  78     /// Used by [`clean::inline`] to tell if an item has already been inlined.
  79     pub(crate) inlined: FxHashSet<ItemId>,
  80     /// Used by `calculate_doc_coverage`.
  81     pub(crate) output_format: OutputFormat,
  82     /// Used by `strip_private`.
  83     pub(crate) show_coverage: bool,
  84 }
  85
  86 impl<'tcx> DocContext<'tcx> {
  87     pub(crate) fn sess(&self) -> &'tcx Session {
  88         self.tcx.sess
  89     }
  90
  91     pub(crate) fn with_param_env<T, F: FnOnce(&mut Self) -> T>(
  92         &mut self,
  93         def_id: DefId,
  94         f: F,
  95     ) -> T {
  96         let old_param_env = mem::replace(&mut self.param_env, self.tcx.param_env(def_id));
  97         let ret = f(self);
  98         self.param_env = old_param_env;
  99         ret
 100     }
 101
 102     pub(crate) fn enter_resolver<F, R>(&self, f: F) -> R
 103     where
 104         F: FnOnce(&mut resolve::Resolver<'_>) -> R,
 105     {
 106         self.resolver.borrow_mut().access(f)
 107     }
 108
 109     /// Call the closure with the given parameters set as
 110     /// the substitutions for a type alias' RHS.
 111     pub(crate) fn enter_alias<F, R>(
 112         &mut self,
 113         substs: FxHashMap<DefId, clean::SubstParam>,
 114         f: F,
 115     ) -> R
 116     where
 117         F: FnOnce(&mut Self) -> R,
 118     {
 119         let old_substs = mem::replace(&mut self.substs, substs);
 120         let r = f(self);
 121         self.substs = old_substs;
 122         r
 123     }
 124
 125     /// Like `hir().local_def_id_to_hir_id()`, but skips calling it on fake DefIds.
 126     /// (This avoids a slice-index-out-of-bounds panic.)
 127     pub(crate) fn as_local_hir_id(tcx: TyCtxt<'_>, item_id: ItemId) -> Option<HirId> {
 128         match item_id {
 129             ItemId::DefId(real_id) => {
 130                 real_id.as_local().map(|def_id| tcx.hir().local_def_id_to_hir_id(def_id))
 131             }
 132             // FIXME: Can this be `Some` for `Auto` or `Blanket`?
 133             _ => None,
 134         }
 135     }
 136
 137     pub(crate) fn with_all_trait_impls(&mut self, f: impl FnOnce(&mut Self, &[DefId])) {
 138         let all_trait_impls = self.resolver_caches.all_trait_impls.take();
 139         f(self, all_trait_impls.as_ref().expect("`all_trait_impls` are already borrowed"));
 140         self.resolver_caches.all_trait_impls = all_trait_impls;
 141     }
 142 }
 143
 144 /// Creates a new diagnostic `Handler` that can be used to emit warnings and errors.
 145 ///
 146 /// If the given `error_format` is `ErrorOutputType::Json` and no `SourceMap` is given, a new one
 147 /// will be created for the handler.
 148 pub(crate) fn new_handler(
 149     error_format: ErrorOutputType,
 150     source_map: Option<Lrc<source_map::SourceMap>>,
 151     diagnostic_width: Option<usize>,
 152     unstable_opts: &UnstableOptions,
 153 ) -> rustc_errors::Handler {
 154     let fallback_bundle =
 155         rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
 156     let emitter: Box<dyn Emitter + sync::Send> = match error_format {
 157         ErrorOutputType::HumanReadable(kind) => {
 158             let (short, color_config) = kind.unzip();
 159             Box::new(
 160                 EmitterWriter::stderr(
 161                     color_config,
 162                     source_map.map(|sm| sm as _),
 163                     None,
 164                     fallback_bundle,
 165                     short,
 166                     unstable_opts.teach,
 167                     diagnostic_width,
 168                     false,
 169                     unstable_opts.track_diagnostics,
 170                 )
 171                 .ui_testing(unstable_opts.ui_testing),
 172             )
 173         }
 174         ErrorOutputType::Json { pretty, json_rendered } => {
 175             let source_map = source_map.unwrap_or_else(|| {
 176                 Lrc::new(source_map::SourceMap::new(source_map::FilePathMapping::empty()))
 177             });
 178             Box::new(
 179                 JsonEmitter::stderr(
 180                     None,
 181                     source_map,
 182                     None,
 183                     fallback_bundle,
 184                     pretty,
 185                     json_rendered,
 186                     diagnostic_width,
 187                     false,
 188                     unstable_opts.track_diagnostics,
 189                 )
 190                 .ui_testing(unstable_opts.ui_testing),
 191             )
 192         }
 193     };
 194
 195     rustc_errors::Handler::with_emitter_and_flags(
 196         emitter,
 197         unstable_opts.diagnostic_handler_flags(true),
 198     )
 199 }
 200
 201 /// Parse, resolve, and typecheck the given crate.
 202 pub(crate) fn create_config(
 203     RustdocOptions {
 204         input,
 205         crate_name,
 206         proc_macro_crate,
 207         error_format,
 208         diagnostic_width,
 209         libs,
 210         externs,
 211         mut cfgs,
 212         check_cfgs,
 213         codegen_options,
 214         unstable_opts,
 215         target,
 216         edition,
 217         maybe_sysroot,
 218         lint_opts,
 219         describe_lints,
 220         lint_cap,
 221         scrape_examples_options,
 222         ..
 223     }: RustdocOptions,
 224 ) -> rustc_interface::Config {
 225     // Add the doc cfg into the doc build.
 226     cfgs.push("doc".to_string());
 227
 228     let cpath = Some(input.clone());
 229     let input = Input::File(input);
 230
 231     // By default, rustdoc ignores all lints.
 232     // Specifically unblock lints relevant to documentation or the lint machinery itself.
 233     let mut lints_to_show = vec![
 234         // it's unclear whether these should be part of rustdoc directly (#77364)
 235         rustc_lint::builtin::MISSING_DOCS.name.to_string(),
 236         rustc_lint::builtin::INVALID_DOC_ATTRIBUTES.name.to_string(),
 237         // these are definitely not part of rustdoc, but we want to warn on them anyway.
 238         rustc_lint::builtin::RENAMED_AND_REMOVED_LINTS.name.to_string(),
 239         rustc_lint::builtin::UNKNOWN_LINTS.name.to_string(),
 240         rustc_lint::builtin::UNEXPECTED_CFGS.name.to_string(),
 241         // this lint is needed to support `#[expect]` attributes
 242         rustc_lint::builtin::UNFULFILLED_LINT_EXPECTATIONS.name.to_string(),
 243     ];
 244     lints_to_show.extend(crate::lint::RUSTDOC_LINTS.iter().map(|lint| lint.name.to_string()));
 245
 246     let (lint_opts, lint_caps) = crate::lint::init_lints(lints_to_show, lint_opts, |lint| {
 247         Some((lint.name_lower(), lint::Allow))
 248     });
 249
 250     let crate_types =
 251         if proc_macro_crate { vec![CrateType::ProcMacro] } else { vec![CrateType::Rlib] };
 252     let test = scrape_examples_options.map(|opts| opts.scrape_tests).unwrap_or(false);
 253     // plays with error output here!
 254     let sessopts = config::Options {
 255         maybe_sysroot,
 256         search_paths: libs,
 257         crate_types,
 258         lint_opts,
 259         lint_cap,
 260         cg: codegen_options,
 261         externs,
 262         target_triple: target,
 263         unstable_features: UnstableFeatures::from_environment(crate_name.as_deref()),
 264         actually_rustdoc: true,
 265         unstable_opts,
 266         error_format,
 267         diagnostic_width,
 268         edition,
 269         describe_lints,
 270         crate_name,
 271         test,
 272         ..Options::default()
 273     };
 274
 275     interface::Config {
 276         opts: sessopts,
 277         crate_cfg: interface::parse_cfgspecs(cfgs),
 278         crate_check_cfg: interface::parse_check_cfg(check_cfgs),
 279         input,
 280         input_path: cpath,
 281         output_file: None,
 282         output_dir: None,
 283         file_loader: None,
 284         lint_caps,
 285         parse_sess_created: None,
 286         register_lints: Some(Box::new(crate::lint::register_lints)),
 287         override_queries: Some(|_sess, providers, _external_providers| {
 288             // Most lints will require typechecking, so just don't run them.
 289             providers.lint_mod = |_, _| {};
 290             // Prevent `rustc_hir_analysis::check_crate` from calling `typeck` on all bodies.
 291             providers.typeck_item_bodies = |_, _| {};
 292             // hack so that `used_trait_imports` won't try to call typeck
 293             providers.used_trait_imports = |_, _| {
 294                 static EMPTY_SET: LazyLock<UnordSet<LocalDefId>> = LazyLock::new(UnordSet::default);
 295                 &EMPTY_SET
 296             };
 297             // In case typeck does end up being called, don't ICE in case there were name resolution errors
 298             providers.typeck = move |tcx, def_id| {
 299                 // Closures' tables come from their outermost function,
 300                 // as they are part of the same "inference environment".
 301                 // This avoids emitting errors for the parent twice (see similar code in `typeck_with_fallback`)
 302                 let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
 303                 if typeck_root_def_id != def_id {
 304                     return tcx.typeck(typeck_root_def_id);
 305                 }
 306
 307                 let hir = tcx.hir();
 308                 let body = hir.body(hir.body_owned_by(def_id));
 309                 debug!("visiting body for {:?}", def_id);
 310                 EmitIgnoredResolutionErrors::new(tcx).visit_body(body);
 311                 (rustc_interface::DEFAULT_QUERY_PROVIDERS.typeck)(tcx, def_id)
 312             };
 313         }),
 314         make_codegen_backend: None,
 315         registry: rustc_driver::diagnostics_registry(),
 316     }
 317 }
 318
 319 pub(crate) fn run_global_ctxt(
 320     tcx: TyCtxt<'_>,
 321     resolver: Rc<RefCell<interface::BoxedResolver>>,
 322     resolver_caches: ResolverCaches,
 323     show_coverage: bool,
 324     render_options: RenderOptions,
 325     output_format: OutputFormat,
 326 ) -> (clean::Crate, RenderOptions, Cache) {
 327     // Certain queries assume that some checks were run elsewhere
 328     // (see https://github.com/rust-lang/rust/pull/73566#issuecomment-656954425),
 329     // so type-check everything other than function bodies in this crate before running lints.
 330
 331     // NOTE: this does not call `tcx.analysis()` so that we won't
 332     // typeck function bodies or run the default rustc lints.
 333     // (see `override_queries` in the `config`)
 334
 335     // HACK(jynelson) this calls an _extremely_ limited subset of `typeck`
 336     // and might break if queries change their assumptions in the future.
 337
 338     // NOTE: This is copy/pasted from typeck/lib.rs and should be kept in sync with those changes.
 339     tcx.sess.time("item_types_checking", || {
 340         tcx.hir().for_each_module(|module| tcx.ensure().check_mod_item_types(module))
 341     });
 342     tcx.sess.abort_if_errors();
 343     tcx.sess.time("missing_docs", || {
 344         rustc_lint::check_crate(tcx, rustc_lint::builtin::MissingDoc::new);
 345     });
 346     tcx.sess.time("check_mod_attrs", || {
 347         tcx.hir().for_each_module(|module| tcx.ensure().check_mod_attrs(module))
 348     });
 349     rustc_passes::stability::check_unused_or_stable_features(tcx);
 350
 351     let auto_traits =
 352         tcx.all_traits().filter(|&trait_def_id| tcx.trait_is_auto(trait_def_id)).collect();
 353
 354     let mut ctxt = DocContext {
 355         tcx,
 356         resolver,
 357         resolver_caches,
 358         param_env: ParamEnv::empty(),
 359         external_traits: Default::default(),
 360         active_extern_traits: Default::default(),
 361         substs: Default::default(),
 362         impl_trait_bounds: Default::default(),
 363         generated_synthetics: Default::default(),
 364         auto_traits,
 365         cache: Cache::new(render_options.document_private),
 366         inlined: FxHashSet::default(),
 367         output_format,
 368         render_options,
 369         show_coverage,
 370     };
 371
 372     // Small hack to force the Sized trait to be present.
 373     //
 374     // Note that in case of `#![no_core]`, the trait is not available.
 375     if let Some(sized_trait_did) = ctxt.tcx.lang_items().sized_trait() {
 376         let sized_trait = build_external_trait(&mut ctxt, sized_trait_did);
 377         ctxt.external_traits.borrow_mut().insert(sized_trait_did, sized_trait);
 378     }
 379
 380     debug!("crate: {:?}", tcx.hir().krate());
 381
 382     let mut krate = tcx.sess.time("clean_crate", || clean::krate(&mut ctxt));
 383
 384     if krate.module.doc_value().map(|d| d.is_empty()).unwrap_or(true) {
 385         let help = format!(
 386             "The following guide may be of use:\n\
 387             {}/rustdoc/how-to-write-documentation.html",
 388             crate::DOC_RUST_LANG_ORG_CHANNEL
 389         );
 390         tcx.struct_lint_node(
 391             crate::lint::MISSING_CRATE_LEVEL_DOCS,
 392             DocContext::as_local_hir_id(tcx, krate.module.item_id).unwrap(),
 393             "no documentation found for this crate's top-level module",
 394             |lint| lint.help(help),
 395         );
 396     }
 397
 398     fn report_deprecated_attr(name: &str, diag: &rustc_errors::Handler, sp: Span) {
 399         let mut msg =
 400             diag.struct_span_warn(sp, &format!("the `#![doc({})]` attribute is deprecated", name));
 401         msg.note(
 402             "see issue #44136 <https://github.com/rust-lang/rust/issues/44136> \
 403             for more information",
 404         );
 405
 406         if name == "no_default_passes" {
 407             msg.help("`#![doc(no_default_passes)]` no longer functions; you may want to use `#![doc(document_private_items)]`");
 408         } else if name.starts_with("passes") {
 409             msg.help("`#![doc(passes = \"...\")]` no longer functions; you may want to use `#![doc(document_private_items)]`");
 410         } else if name.starts_with("plugins") {
 411             msg.warn("`#![doc(plugins = \"...\")]` no longer functions; see CVE-2018-1000622 <https://nvd.nist.gov/vuln/detail/CVE-2018-1000622>");
 412         }
 413
 414         msg.emit();
 415     }
 416
 417     // Process all of the crate attributes, extracting plugin metadata along
 418     // with the passes which we are supposed to run.
 419     for attr in krate.module.attrs.lists(sym::doc) {
 420         let diag = ctxt.sess().diagnostic();
 421
 422         let name = attr.name_or_empty();
 423         // `plugins = "..."`, `no_default_passes`, and `passes = "..."` have no effect
 424         if attr.is_word() && name == sym::no_default_passes {
 425             report_deprecated_attr("no_default_passes", diag, attr.span());
 426         } else if attr.value_str().is_some() {
 427             match name {
 428                 sym::passes => {
 429                     report_deprecated_attr("passes = \"...\"", diag, attr.span());
 430                 }
 431                 sym::plugins => {
 432                     report_deprecated_attr("plugins = \"...\"", diag, attr.span());
 433                 }
 434                 _ => (),
 435             }
 436         }
 437
 438         if attr.is_word() && name == sym::document_private_items {
 439             ctxt.render_options.document_private = true;
 440         }
 441     }
 442
 443     info!("Executing passes");
 444
 445     for p in passes::defaults(show_coverage) {
 446         let run = match p.condition {
 447             Always => true,
 448             WhenDocumentPrivate => ctxt.render_options.document_private,
 449             WhenNotDocumentPrivate => !ctxt.render_options.document_private,
 450             WhenNotDocumentHidden => !ctxt.render_options.document_hidden,
 451         };
 452         if run {
 453             debug!("running pass {}", p.pass.name);
 454             krate = tcx.sess.time(p.pass.name, || (p.pass.run)(krate, &mut ctxt));
 455         }
 456     }
 457
 458     tcx.sess.time("check_lint_expectations", || tcx.check_expectations(Some(sym::rustdoc)));
 459
 460     if tcx.sess.diagnostic().has_errors_or_lint_errors().is_some() {
 461         rustc_errors::FatalError.raise();
 462     }
 463
 464     krate = tcx.sess.time("create_format_cache", || Cache::populate(&mut ctxt, krate));
 465
 466     (krate, ctxt.render_options, ctxt.cache)
 467 }
 468
 469 /// Due to <https://github.com/rust-lang/rust/pull/73566>,
 470 /// the name resolution pass may find errors that are never emitted.
 471 /// If typeck is called after this happens, then we'll get an ICE:
 472 /// 'Res::Error found but not reported'. To avoid this, emit the errors now.
 473 struct EmitIgnoredResolutionErrors<'tcx> {
 474     tcx: TyCtxt<'tcx>,
 475 }
 476
 477 impl<'tcx> EmitIgnoredResolutionErrors<'tcx> {
 478     fn new(tcx: TyCtxt<'tcx>) -> Self {
 479         Self { tcx }
 480     }
 481 }
 482
 483 impl<'tcx> Visitor<'tcx> for EmitIgnoredResolutionErrors<'tcx> {
 484     type NestedFilter = nested_filter::OnlyBodies;
 485
 486     fn nested_visit_map(&mut self) -> Self::Map {
 487         // We need to recurse into nested closures,
 488         // since those will fallback to the parent for type checking.
 489         self.tcx.hir()
 490     }
 491
 492     fn visit_path(&mut self, path: &Path<'tcx>, _id: HirId) {
 493         debug!("visiting path {:?}", path);
 494         if path.res == Res::Err {
 495             // We have less context here than in rustc_resolve,
 496             // so we can only emit the name and span.
 497             // However we can give a hint that rustc_resolve will have more info.
 498             let label = format!(
 499                 "could not resolve path `{}`",
 500                 path.segments
 501                     .iter()
 502                     .map(|segment| segment.ident.as_str())
 503                     .intersperse("::")
 504                     .collect::<String>()
 505             );
 506             let mut err = rustc_errors::struct_span_err!(
 507                 self.tcx.sess,
 508                 path.span,
 509                 E0433,
 510                 "failed to resolve: {}",
 511                 label
 512             );
 513             err.span_label(path.span, label);
 514             err.note("this error was originally ignored because you are running `rustdoc`");
 515             err.note("try running again with `rustc` or `cargo check` and you may get a more detailed error");
 516             err.emit();
 517         }
 518         // We could have an outer resolution that succeeded,
 519         // but with generic parameters that failed.
 520         // Recurse into the segments so we catch those too.
 521         intravisit::walk_path(self, path);
 522     }
 523 }
 524
 525 /// `DefId` or parameter index (`ty::ParamTy.index`) of a synthetic type parameter
 526 /// for `impl Trait` in argument position.
 527 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 528 pub(crate) enum ImplTraitParam {
 529     DefId(DefId),
 530     ParamIndex(u32),
 531 }
 532
 533 impl From<DefId> for ImplTraitParam {
 534     fn from(did: DefId) -> Self {
 535         ImplTraitParam::DefId(did)
 536     }
 537 }
 538
 539 impl From<u32> for ImplTraitParam {
 540     fn from(idx: u32) -> Self {
 541         ImplTraitParam::ParamIndex(idx)
 542     }
 543 }