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Member "rustc-1.60.0-src/src/librustdoc/core.rs" (4 Apr 2022, 20683 Bytes) of package /linux/misc/rustc-1.60.0-src.tar.xz:


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