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_errors::emitter::{Emitter, EmitterWriter};
   5 use rustc_errors::json::JsonEmitter;
   6 use rustc_feature::UnstableFeatures;
   7 use rustc_hir::def::{Namespace, Res};
   8 use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId};
   9 use rustc_hir::intravisit::{self, Visitor};
  10 use rustc_hir::{HirId, Path, TraitCandidate};
  11 use rustc_interface::interface;
  12 use rustc_middle::hir::nested_filter;
  13 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
  14 use rustc_resolve as resolve;
  15 use rustc_session::config::{self, CrateType, ErrorOutputType};
  16 use rustc_session::lint;
  17 use rustc_session::DiagnosticOutput;
  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_traits: Option<Vec<DefId>>,
  43     pub(crate) all_trait_impls: Option<Vec<DefId>>,
  44     pub(crate) all_macro_rules: FxHashMap<Symbol, Res<NodeId>>,
  45 }
  46
  47 pub(crate) struct DocContext<'tcx> {
  48     pub(crate) tcx: TyCtxt<'tcx>,
  49     /// Name resolver. Used for intra-doc links.
  50     ///
  51     /// The `Rc<RefCell<...>>` wrapping is needed because that is what's returned by
  52     /// [`rustc_interface::Queries::expansion()`].
  53     // FIXME: see if we can get rid of this RefCell somehow
  54     pub(crate) resolver: Rc<RefCell<interface::BoxedResolver>>,
  55     pub(crate) resolver_caches: ResolverCaches,
  56     /// Used for normalization.
  57     ///
  58     /// Most of this logic is copied from rustc_lint::late.
  59     pub(crate) param_env: ParamEnv<'tcx>,
  60     /// Later on moved through `clean::Crate` into `cache`
  61     pub(crate) external_traits: Rc<RefCell<FxHashMap<DefId, clean::Trait>>>,
  62     /// Used while populating `external_traits` to ensure we don't process the same trait twice at
  63     /// the same time.
  64     pub(crate) active_extern_traits: FxHashSet<DefId>,
  65     // The current set of parameter substitutions,
  66     // for expanding type aliases at the HIR level:
  67     /// Table `DefId` of type, lifetime, or const parameter -> substituted type, lifetime, or const
  68     pub(crate) substs: FxHashMap<DefId, clean::SubstParam>,
  69     /// Table synthetic type parameter for `impl Trait` in argument position -> bounds
  70     pub(crate) impl_trait_bounds: FxHashMap<ImplTraitParam, Vec<clean::GenericBound>>,
  71     /// Auto-trait or blanket impls processed so far, as `(self_ty, trait_def_id)`.
  72     // FIXME(eddyb) make this a `ty::TraitRef<'tcx>` set.
  73     pub(crate) generated_synthetics: FxHashSet<(Ty<'tcx>, DefId)>,
  74     pub(crate) auto_traits: Vec<DefId>,
  75     /// The options given to rustdoc that could be relevant to a pass.
  76     pub(crate) render_options: RenderOptions,
  77     /// This same cache is used throughout rustdoc, including in [`crate::html::render`].
  78     pub(crate) cache: Cache,
  79     /// Used by [`clean::inline`] to tell if an item has already been inlined.
  80     pub(crate) inlined: FxHashSet<ItemId>,
  81     /// Used by `calculate_doc_coverage`.
  82     pub(crate) output_format: OutputFormat,
  83     /// Used by `strip_private`.
  84     pub(crate) show_coverage: bool,
  85 }
  86
  87 impl<'tcx> DocContext<'tcx> {
  88     pub(crate) fn sess(&self) -> &'tcx Session {
  89         self.tcx.sess
  90     }
  91
  92     pub(crate) fn with_param_env<T, F: FnOnce(&mut Self) -> T>(
  93         &mut self,
  94         def_id: DefId,
  95         f: F,
  96     ) -> T {
  97         let old_param_env = mem::replace(&mut self.param_env, self.tcx.param_env(def_id));
  98         let ret = f(self);
  99         self.param_env = old_param_env;
 100         ret
 101     }
 102
 103     pub(crate) fn enter_resolver<F, R>(&self, f: F) -> R
 104     where
 105         F: FnOnce(&mut resolve::Resolver<'_>) -> R,
 106     {
 107         self.resolver.borrow_mut().access(f)
 108     }
 109
 110     /// Call the closure with the given parameters set as
 111     /// the substitutions for a type alias' RHS.
 112     pub(crate) fn enter_alias<F, R>(
 113         &mut self,
 114         substs: FxHashMap<DefId, clean::SubstParam>,
 115         f: F,
 116     ) -> R
 117     where
 118         F: FnOnce(&mut Self) -> R,
 119     {
 120         let old_substs = mem::replace(&mut self.substs, substs);
 121         let r = f(self);
 122         self.substs = old_substs;
 123         r
 124     }
 125
 126     /// Like `hir().local_def_id_to_hir_id()`, but skips calling it on fake DefIds.
 127     /// (This avoids a slice-index-out-of-bounds panic.)
 128     pub(crate) fn as_local_hir_id(tcx: TyCtxt<'_>, item_id: ItemId) -> Option<HirId> {
 129         match item_id {
 130             ItemId::DefId(real_id) => {
 131                 real_id.as_local().map(|def_id| tcx.hir().local_def_id_to_hir_id(def_id))
 132             }
 133             // FIXME: Can this be `Some` for `Auto` or `Blanket`?
 134             _ => None,
 135         }
 136     }
 137
 138     pub(crate) fn with_all_traits(&mut self, f: impl FnOnce(&mut Self, &[DefId])) {
 139         let all_traits = self.resolver_caches.all_traits.take();
 140         f(self, all_traits.as_ref().expect("`all_traits` are already borrowed"));
 141         self.resolver_caches.all_traits = all_traits;
 142     }
 143
 144     pub(crate) fn with_all_trait_impls(&mut self, f: impl FnOnce(&mut Self, &[DefId])) {
 145         let all_trait_impls = self.resolver_caches.all_trait_impls.take();
 146         f(self, all_trait_impls.as_ref().expect("`all_trait_impls` are already borrowed"));
 147         self.resolver_caches.all_trait_impls = all_trait_impls;
 148     }
 149 }
 150
 151 /// Creates a new diagnostic `Handler` that can be used to emit warnings and errors.
 152 ///
 153 /// If the given `error_format` is `ErrorOutputType::Json` and no `SourceMap` is given, a new one
 154 /// will be created for the handler.
 155 pub(crate) fn new_handler(
 156     error_format: ErrorOutputType,
 157     source_map: Option<Lrc<source_map::SourceMap>>,
 158     diagnostic_width: Option<usize>,
 159     unstable_opts: &UnstableOptions,
 160 ) -> rustc_errors::Handler {
 161     let fallback_bundle =
 162         rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
 163     let emitter: Box<dyn Emitter + sync::Send> = match error_format {
 164         ErrorOutputType::HumanReadable(kind) => {
 165             let (short, color_config) = kind.unzip();
 166             Box::new(
 167                 EmitterWriter::stderr(
 168                     color_config,
 169                     source_map.map(|sm| sm as _),
 170                     None,
 171                     fallback_bundle,
 172                     short,
 173                     unstable_opts.teach,
 174                     diagnostic_width,
 175                     false,
 176                 )
 177                 .ui_testing(unstable_opts.ui_testing),
 178             )
 179         }
 180         ErrorOutputType::Json { pretty, json_rendered } => {
 181             let source_map = source_map.unwrap_or_else(|| {
 182                 Lrc::new(source_map::SourceMap::new(source_map::FilePathMapping::empty()))
 183             });
 184             Box::new(
 185                 JsonEmitter::stderr(
 186                     None,
 187                     source_map,
 188                     None,
 189                     fallback_bundle,
 190                     pretty,
 191                     json_rendered,
 192                     diagnostic_width,
 193                     false,
 194                 )
 195                 .ui_testing(unstable_opts.ui_testing),
 196             )
 197         }
 198     };
 199
 200     rustc_errors::Handler::with_emitter_and_flags(
 201         emitter,
 202         unstable_opts.diagnostic_handler_flags(true),
 203     )
 204 }
 205
 206 /// Parse, resolve, and typecheck the given crate.
 207 pub(crate) fn create_config(
 208     RustdocOptions {
 209         input,
 210         crate_name,
 211         proc_macro_crate,
 212         error_format,
 213         diagnostic_width,
 214         libs,
 215         externs,
 216         mut cfgs,
 217         check_cfgs,
 218         codegen_options,
 219         unstable_opts,
 220         target,
 221         edition,
 222         maybe_sysroot,
 223         lint_opts,
 224         describe_lints,
 225         lint_cap,
 226         scrape_examples_options,
 227         ..
 228     }: RustdocOptions,
 229 ) -> rustc_interface::Config {
 230     // Add the doc cfg into the doc build.
 231     cfgs.push("doc".to_string());
 232
 233     let cpath = Some(input.clone());
 234     let input = Input::File(input);
 235
 236     // By default, rustdoc ignores all lints.
 237     // Specifically unblock lints relevant to documentation or the lint machinery itself.
 238     let mut lints_to_show = vec![
 239         // it's unclear whether these should be part of rustdoc directly (#77364)
 240         rustc_lint::builtin::MISSING_DOCS.name.to_string(),
 241         rustc_lint::builtin::INVALID_DOC_ATTRIBUTES.name.to_string(),
 242         // these are definitely not part of rustdoc, but we want to warn on them anyway.
 243         rustc_lint::builtin::RENAMED_AND_REMOVED_LINTS.name.to_string(),
 244         rustc_lint::builtin::UNKNOWN_LINTS.name.to_string(),
 245         rustc_lint::builtin::UNEXPECTED_CFGS.name.to_string(),
 246         // this lint is needed to support `#[expect]` attributes
 247         rustc_lint::builtin::UNFULFILLED_LINT_EXPECTATIONS.name.to_string(),
 248     ];
 249     lints_to_show.extend(crate::lint::RUSTDOC_LINTS.iter().map(|lint| lint.name.to_string()));
 250
 251     let (lint_opts, lint_caps) = crate::lint::init_lints(lints_to_show, lint_opts, |lint| {
 252         Some((lint.name_lower(), lint::Allow))
 253     });
 254
 255     let crate_types =
 256         if proc_macro_crate { vec![CrateType::ProcMacro] } else { vec![CrateType::Rlib] };
 257     let test = scrape_examples_options.map(|opts| opts.scrape_tests).unwrap_or(false);
 258     // plays with error output here!
 259     let sessopts = config::Options {
 260         maybe_sysroot,
 261         search_paths: libs,
 262         crate_types,
 263         lint_opts,
 264         lint_cap,
 265         cg: codegen_options,
 266         externs,
 267         target_triple: target,
 268         unstable_features: UnstableFeatures::from_environment(crate_name.as_deref()),
 269         actually_rustdoc: true,
 270         unstable_opts,
 271         error_format,
 272         diagnostic_width,
 273         edition,
 274         describe_lints,
 275         crate_name,
 276         test,
 277         ..Options::default()
 278     };
 279
 280     interface::Config {
 281         opts: sessopts,
 282         crate_cfg: interface::parse_cfgspecs(cfgs),
 283         crate_check_cfg: interface::parse_check_cfg(check_cfgs),
 284         input,
 285         input_path: cpath,
 286         output_file: None,
 287         output_dir: None,
 288         file_loader: None,
 289         diagnostic_output: DiagnosticOutput::Default,
 290         lint_caps,
 291         parse_sess_created: None,
 292         register_lints: Some(Box::new(crate::lint::register_lints)),
 293         override_queries: Some(|_sess, providers, _external_providers| {
 294             // Most lints will require typechecking, so just don't run them.
 295             providers.lint_mod = |_, _| {};
 296             // Prevent `rustc_hir_analysis::check_crate` from calling `typeck` on all bodies.
 297             providers.typeck_item_bodies = |_, _| {};
 298             // hack so that `used_trait_imports` won't try to call typeck
 299             providers.used_trait_imports = |_, _| {
 300                 static EMPTY_SET: LazyLock<FxHashSet<LocalDefId>> =
 301                     LazyLock::new(FxHashSet::default);
 302                 &EMPTY_SET
 303             };
 304             // In case typeck does end up being called, don't ICE in case there were name resolution errors
 305             providers.typeck = move |tcx, def_id| {
 306                 // Closures' tables come from their outermost function,
 307                 // as they are part of the same "inference environment".
 308                 // This avoids emitting errors for the parent twice (see similar code in `typeck_with_fallback`)
 309                 let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
 310                 if typeck_root_def_id != def_id {
 311                     return tcx.typeck(typeck_root_def_id);
 312                 }
 313
 314                 let hir = tcx.hir();
 315                 let body = hir.body(hir.body_owned_by(def_id));
 316                 debug!("visiting body for {:?}", def_id);
 317                 EmitIgnoredResolutionErrors::new(tcx).visit_body(body);
 318                 (rustc_interface::DEFAULT_QUERY_PROVIDERS.typeck)(tcx, def_id)
 319             };
 320         }),
 321         make_codegen_backend: None,
 322         registry: rustc_driver::diagnostics_registry(),
 323     }
 324 }
 325
 326 pub(crate) fn run_global_ctxt(
 327     tcx: TyCtxt<'_>,
 328     resolver: Rc<RefCell<interface::BoxedResolver>>,
 329     resolver_caches: ResolverCaches,
 330     show_coverage: bool,
 331     render_options: RenderOptions,
 332     output_format: OutputFormat,
 333 ) -> (clean::Crate, RenderOptions, Cache) {
 334     // Certain queries assume that some checks were run elsewhere
 335     // (see https://github.com/rust-lang/rust/pull/73566#issuecomment-656954425),
 336     // so type-check everything other than function bodies in this crate before running lints.
 337
 338     // NOTE: this does not call `tcx.analysis()` so that we won't
 339     // typeck function bodies or run the default rustc lints.
 340     // (see `override_queries` in the `config`)
 341
 342     // HACK(jynelson) this calls an _extremely_ limited subset of `typeck`
 343     // and might break if queries change their assumptions in the future.
 344
 345     // NOTE: This is copy/pasted from typeck/lib.rs and should be kept in sync with those changes.
 346     tcx.sess.time("item_types_checking", || {
 347         tcx.hir().for_each_module(|module| tcx.ensure().check_mod_item_types(module))
 348     });
 349     tcx.sess.abort_if_errors();
 350     tcx.sess.time("missing_docs", || {
 351         rustc_lint::check_crate(tcx, rustc_lint::builtin::MissingDoc::new);
 352     });
 353     tcx.sess.time("check_mod_attrs", || {
 354         tcx.hir().for_each_module(|module| tcx.ensure().check_mod_attrs(module))
 355     });
 356     rustc_passes::stability::check_unused_or_stable_features(tcx);
 357
 358     let auto_traits = resolver_caches
 359         .all_traits
 360         .as_ref()
 361         .expect("`all_traits` are already borrowed")
 362         .iter()
 363         .copied()
 364         .filter(|&trait_def_id| tcx.trait_is_auto(trait_def_id))
 365         .collect();
 366     let access_levels = tcx.privacy_access_levels(()).map_id(Into::into);
 367
 368     let mut ctxt = DocContext {
 369         tcx,
 370         resolver,
 371         resolver_caches,
 372         param_env: ParamEnv::empty(),
 373         external_traits: Default::default(),
 374         active_extern_traits: Default::default(),
 375         substs: Default::default(),
 376         impl_trait_bounds: Default::default(),
 377         generated_synthetics: Default::default(),
 378         auto_traits,
 379         cache: Cache::new(access_levels, render_options.document_private),
 380         inlined: FxHashSet::default(),
 381         output_format,
 382         render_options,
 383         show_coverage,
 384     };
 385
 386     // Small hack to force the Sized trait to be present.
 387     //
 388     // Note that in case of `#![no_core]`, the trait is not available.
 389     if let Some(sized_trait_did) = ctxt.tcx.lang_items().sized_trait() {
 390         let sized_trait = build_external_trait(&mut ctxt, sized_trait_did);
 391         ctxt.external_traits.borrow_mut().insert(sized_trait_did, sized_trait);
 392     }
 393
 394     debug!("crate: {:?}", tcx.hir().krate());
 395
 396     let mut krate = tcx.sess.time("clean_crate", || clean::krate(&mut ctxt));
 397
 398     if krate.module.doc_value().map(|d| d.is_empty()).unwrap_or(true) {
 399         let help = format!(
 400             "The following guide may be of use:\n\
 401             {}/rustdoc/how-to-write-documentation.html",
 402             crate::DOC_RUST_LANG_ORG_CHANNEL
 403         );
 404         tcx.struct_lint_node(
 405             crate::lint::MISSING_CRATE_LEVEL_DOCS,
 406             DocContext::as_local_hir_id(tcx, krate.module.item_id).unwrap(),
 407             "no documentation found for this crate's top-level module",
 408             |lint| lint.help(help),
 409         );
 410     }
 411
 412     fn report_deprecated_attr(name: &str, diag: &rustc_errors::Handler, sp: Span) {
 413         let mut msg =
 414             diag.struct_span_warn(sp, &format!("the `#![doc({})]` attribute is deprecated", name));
 415         msg.note(
 416             "see issue #44136 <https://github.com/rust-lang/rust/issues/44136> \
 417             for more information",
 418         );
 419
 420         if name == "no_default_passes" {
 421             msg.help("`#![doc(no_default_passes)]` no longer functions; you may want to use `#![doc(document_private_items)]`");
 422         } else if name.starts_with("passes") {
 423             msg.help("`#![doc(passes = \"...\")]` no longer functions; you may want to use `#![doc(document_private_items)]`");
 424         } else if name.starts_with("plugins") {
 425             msg.warn("`#![doc(plugins = \"...\")]` no longer functions; see CVE-2018-1000622 <https://nvd.nist.gov/vuln/detail/CVE-2018-1000622>");
 426         }
 427
 428         msg.emit();
 429     }
 430
 431     // Process all of the crate attributes, extracting plugin metadata along
 432     // with the passes which we are supposed to run.
 433     for attr in krate.module.attrs.lists(sym::doc) {
 434         let diag = ctxt.sess().diagnostic();
 435
 436         let name = attr.name_or_empty();
 437         // `plugins = "..."`, `no_default_passes`, and `passes = "..."` have no effect
 438         if attr.is_word() && name == sym::no_default_passes {
 439             report_deprecated_attr("no_default_passes", diag, attr.span());
 440         } else if attr.value_str().is_some() {
 441             match name {
 442                 sym::passes => {
 443                     report_deprecated_attr("passes = \"...\"", diag, attr.span());
 444                 }
 445                 sym::plugins => {
 446                     report_deprecated_attr("plugins = \"...\"", diag, attr.span());
 447                 }
 448                 _ => (),
 449             }
 450         }
 451
 452         if attr.is_word() && name == sym::document_private_items {
 453             ctxt.render_options.document_private = true;
 454         }
 455     }
 456
 457     info!("Executing passes");
 458
 459     for p in passes::defaults(show_coverage) {
 460         let run = match p.condition {
 461             Always => true,
 462             WhenDocumentPrivate => ctxt.render_options.document_private,
 463             WhenNotDocumentPrivate => !ctxt.render_options.document_private,
 464             WhenNotDocumentHidden => !ctxt.render_options.document_hidden,
 465         };
 466         if run {
 467             debug!("running pass {}", p.pass.name);
 468             krate = tcx.sess.time(p.pass.name, || (p.pass.run)(krate, &mut ctxt));
 469         }
 470     }
 471
 472     tcx.sess.time("check_lint_expectations", || tcx.check_expectations(Some(sym::rustdoc)));
 473
 474     if tcx.sess.diagnostic().has_errors_or_lint_errors().is_some() {
 475         rustc_errors::FatalError.raise();
 476     }
 477
 478     krate = tcx.sess.time("create_format_cache", || Cache::populate(&mut ctxt, krate));
 479
 480     (krate, ctxt.render_options, ctxt.cache)
 481 }
 482
 483 /// Due to <https://github.com/rust-lang/rust/pull/73566>,
 484 /// the name resolution pass may find errors that are never emitted.
 485 /// If typeck is called after this happens, then we'll get an ICE:
 486 /// 'Res::Error found but not reported'. To avoid this, emit the errors now.
 487 struct EmitIgnoredResolutionErrors<'tcx> {
 488     tcx: TyCtxt<'tcx>,
 489 }
 490
 491 impl<'tcx> EmitIgnoredResolutionErrors<'tcx> {
 492     fn new(tcx: TyCtxt<'tcx>) -> Self {
 493         Self { tcx }
 494     }
 495 }
 496
 497 impl<'tcx> Visitor<'tcx> for EmitIgnoredResolutionErrors<'tcx> {
 498     type NestedFilter = nested_filter::OnlyBodies;
 499
 500     fn nested_visit_map(&mut self) -> Self::Map {
 501         // We need to recurse into nested closures,
 502         // since those will fallback to the parent for type checking.
 503         self.tcx.hir()
 504     }
 505
 506     fn visit_path(&mut self, path: &'tcx Path<'_>, _id: HirId) {
 507         debug!("visiting path {:?}", path);
 508         if path.res == Res::Err {
 509             // We have less context here than in rustc_resolve,
 510             // so we can only emit the name and span.
 511             // However we can give a hint that rustc_resolve will have more info.
 512             let label = format!(
 513                 "could not resolve path `{}`",
 514                 path.segments
 515                     .iter()
 516                     .map(|segment| segment.ident.as_str())
 517                     .intersperse("::")
 518                     .collect::<String>()
 519             );
 520             let mut err = rustc_errors::struct_span_err!(
 521                 self.tcx.sess,
 522                 path.span,
 523                 E0433,
 524                 "failed to resolve: {}",
 525                 label
 526             );
 527             err.span_label(path.span, label);
 528             err.note("this error was originally ignored because you are running `rustdoc`");
 529             err.note("try running again with `rustc` or `cargo check` and you may get a more detailed error");
 530             err.emit();
 531         }
 532         // We could have an outer resolution that succeeded,
 533         // but with generic parameters that failed.
 534         // Recurse into the segments so we catch those too.
 535         intravisit::walk_path(self, path);
 536     }
 537 }
 538
 539 /// `DefId` or parameter index (`ty::ParamTy.index`) of a synthetic type parameter
 540 /// for `impl Trait` in argument position.
 541 #[derive(Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 542 pub(crate) enum ImplTraitParam {
 543     DefId(DefId),
 544     ParamIndex(u32),
 545 }
 546
 547 impl From<DefId> for ImplTraitParam {
 548     fn from(did: DefId) -> Self {
 549         ImplTraitParam::DefId(did)
 550     }
 551 }
 552
 553 impl From<u32> for ImplTraitParam {
 554     fn from(idx: u32) -> Self {
 555         ImplTraitParam::ParamIndex(idx)
 556     }
 557 }