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