src/librustdoc/visit_ast.rs

   1 // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Rust AST Visitor. Extracts useful information and massages it into a form
  12 //! usable for clean
  13
  14 use std::mem;
  15
  16 use syntax::ast;
  17 use syntax::attr;
  18 use syntax::ext::base::MacroKind;
  19 use syntax::source_map::Spanned;
  20 use syntax_pos::{self, Span};
  21
  22 use rustc::hir::Node;
  23 use rustc::hir::def::Def;
  24 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
  25 use rustc::middle::privacy::AccessLevel;
  26 use rustc::util::nodemap::{FxHashSet, FxHashMap};
  27
  28 use rustc::hir;
  29
  30 use core;
  31 use clean::{self, AttributesExt, NestedAttributesExt, def_id_to_path};
  32 use doctree::*;
  33
  34 // looks to me like the first two of these are actually
  35 // output parameters, maybe only mutated once; perhaps
  36 // better simply to have the visit method return a tuple
  37 // containing them?
  38
  39 // also, is there some reason that this doesn't use the 'visit'
  40 // framework from syntax?
  41
  42 pub struct RustdocVisitor<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx> {
  43     pub module: Module,
  44     pub attrs: hir::HirVec<ast::Attribute>,
  45     pub cx: &'a core::DocContext<'a, 'tcx, 'rcx, 'cstore>,
  46     view_item_stack: FxHashSet<ast::NodeId>,
  47     inlining: bool,
  48     /// Is the current module and all of its parents public?
  49     inside_public_path: bool,
  50     exact_paths: Option<FxHashMap<DefId, Vec<String>>>,
  51 }
  52
  53 impl<'a, 'tcx, 'rcx, 'cstore> RustdocVisitor<'a, 'tcx, 'rcx, 'cstore> {
  54     pub fn new(
  55         cx: &'a core::DocContext<'a, 'tcx, 'rcx, 'cstore>
  56     ) -> RustdocVisitor<'a, 'tcx, 'rcx, 'cstore> {
  57         // If the root is re-exported, terminate all recursion.
  58         let mut stack = FxHashSet::default();
  59         stack.insert(ast::CRATE_NODE_ID);
  60         RustdocVisitor {
  61             module: Module::new(None),
  62             attrs: hir::HirVec::new(),
  63             cx,
  64             view_item_stack: stack,
  65             inlining: false,
  66             inside_public_path: true,
  67             exact_paths: Some(FxHashMap::default()),
  68         }
  69     }
  70
  71     fn store_path(&mut self, did: DefId) {
  72         // We can't use the entry api, as that keeps the mutable borrow of self active
  73         // when we try to use cx
  74         let exact_paths = self.exact_paths.as_mut().unwrap();
  75         if exact_paths.get(&did).is_none() {
  76             let path = def_id_to_path(self.cx, did, self.cx.crate_name.clone());
  77             exact_paths.insert(did, path);
  78         }
  79     }
  80
  81     fn stability(&self, id: ast::NodeId) -> Option<attr::Stability> {
  82         self.cx.tcx.hir.opt_local_def_id(id)
  83             .and_then(|def_id| self.cx.tcx.lookup_stability(def_id)).cloned()
  84     }
  85
  86     fn deprecation(&self, id: ast::NodeId) -> Option<attr::Deprecation> {
  87         self.cx.tcx.hir.opt_local_def_id(id)
  88             .and_then(|def_id| self.cx.tcx.lookup_deprecation(def_id))
  89     }
  90
  91     pub fn visit(&mut self, krate: &hir::Crate) {
  92         self.attrs = krate.attrs.clone();
  93
  94         self.module = self.visit_mod_contents(krate.span,
  95                                               krate.attrs.clone(),
  96                                               Spanned { span: syntax_pos::DUMMY_SP,
  97                                                         node: hir::VisibilityKind::Public },
  98                                               ast::CRATE_NODE_ID,
  99                                               &krate.module,
 100                                               None);
 101         // attach the crate's exported macros to the top-level module:
 102         let macro_exports: Vec<_> =
 103             krate.exported_macros.iter().map(|def| self.visit_local_macro(def)).collect();
 104         self.module.macros.extend(macro_exports);
 105         self.module.is_crate = true;
 106
 107         self.cx.renderinfo.borrow_mut().exact_paths = self.exact_paths.take().unwrap();
 108     }
 109
 110     pub fn visit_variant_data(&mut self, item: &hir::Item,
 111                               name: ast::Name, sd: &hir::VariantData,
 112                               generics: &hir::Generics) -> Struct {
 113         debug!("Visiting struct");
 114         let struct_type = struct_type_from_def(&*sd);
 115         Struct {
 116             id: item.id,
 117             struct_type,
 118             name,
 119             vis: item.vis.clone(),
 120             stab: self.stability(item.id),
 121             depr: self.deprecation(item.id),
 122             attrs: item.attrs.clone(),
 123             generics: generics.clone(),
 124             fields: sd.fields().iter().cloned().collect(),
 125             whence: item.span
 126         }
 127     }
 128
 129     pub fn visit_union_data(&mut self, item: &hir::Item,
 130                             name: ast::Name, sd: &hir::VariantData,
 131                             generics: &hir::Generics) -> Union {
 132         debug!("Visiting union");
 133         let struct_type = struct_type_from_def(&*sd);
 134         Union {
 135             id: item.id,
 136             struct_type,
 137             name,
 138             vis: item.vis.clone(),
 139             stab: self.stability(item.id),
 140             depr: self.deprecation(item.id),
 141             attrs: item.attrs.clone(),
 142             generics: generics.clone(),
 143             fields: sd.fields().iter().cloned().collect(),
 144             whence: item.span
 145         }
 146     }
 147
 148     pub fn visit_enum_def(&mut self, it: &hir::Item,
 149                           name: ast::Name, def: &hir::EnumDef,
 150                           params: &hir::Generics) -> Enum {
 151         debug!("Visiting enum");
 152         Enum {
 153             name,
 154             variants: def.variants.iter().map(|v| Variant {
 155                 name: v.node.name,
 156                 attrs: v.node.attrs.clone(),
 157                 stab: self.stability(v.node.data.id()),
 158                 depr: self.deprecation(v.node.data.id()),
 159                 def: v.node.data.clone(),
 160                 whence: v.span,
 161             }).collect(),
 162             vis: it.vis.clone(),
 163             stab: self.stability(it.id),
 164             depr: self.deprecation(it.id),
 165             generics: params.clone(),
 166             attrs: it.attrs.clone(),
 167             id: it.id,
 168             whence: it.span,
 169         }
 170     }
 171
 172     pub fn visit_fn(&mut self, om: &mut Module, item: &hir::Item,
 173                     name: ast::Name, fd: &hir::FnDecl,
 174                     header: hir::FnHeader,
 175                     gen: &hir::Generics,
 176                     body: hir::BodyId) {
 177         debug!("Visiting fn");
 178         let macro_kind = item.attrs.iter().filter_map(|a| {
 179             if a.check_name("proc_macro") {
 180                 Some(MacroKind::Bang)
 181             } else if a.check_name("proc_macro_derive") {
 182                 Some(MacroKind::Derive)
 183             } else if a.check_name("proc_macro_attribute") {
 184                 Some(MacroKind::Attr)
 185             } else {
 186                 None
 187             }
 188         }).next();
 189         match macro_kind {
 190             Some(kind) => {
 191                 let name = if kind == MacroKind::Derive {
 192                     item.attrs.lists("proc_macro_derive")
 193                               .filter_map(|mi| mi.name())
 194                               .next()
 195                               .expect("proc-macro derives require a name")
 196                 } else {
 197                     name
 198                 };
 199
 200                 let mut helpers = Vec::new();
 201                 for mi in item.attrs.lists("proc_macro_derive") {
 202                     if !mi.check_name("attributes") {
 203                         continue;
 204                     }
 205
 206                     if let Some(list) = mi.meta_item_list() {
 207                         for inner_mi in list {
 208                             if let Some(name) = inner_mi.name() {
 209                                 helpers.push(name);
 210                             }
 211                         }
 212                     }
 213                 }
 214
 215                 om.proc_macros.push(ProcMacro {
 216                     name,
 217                     id: item.id,
 218                     kind,
 219                     helpers,
 220                     attrs: item.attrs.clone(),
 221                     whence: item.span,
 222                     stab: self.stability(item.id),
 223                     depr: self.deprecation(item.id),
 224                 });
 225             }
 226             None => {
 227                 om.fns.push(Function {
 228                     id: item.id,
 229                     vis: item.vis.clone(),
 230                     stab: self.stability(item.id),
 231                     depr: self.deprecation(item.id),
 232                     attrs: item.attrs.clone(),
 233                     decl: fd.clone(),
 234                     name,
 235                     whence: item.span,
 236                     generics: gen.clone(),
 237                     header,
 238                     body,
 239                 });
 240             }
 241         }
 242     }
 243
 244     pub fn visit_mod_contents(&mut self, span: Span, attrs: hir::HirVec<ast::Attribute>,
 245                               vis: hir::Visibility, id: ast::NodeId,
 246                               m: &hir::Mod,
 247                               name: Option<ast::Name>) -> Module {
 248         let mut om = Module::new(name);
 249         om.where_outer = span;
 250         om.where_inner = m.inner;
 251         om.attrs = attrs;
 252         om.vis = vis.clone();
 253         om.stab = self.stability(id);
 254         om.depr = self.deprecation(id);
 255         om.id = id;
 256         // Keep track of if there were any private modules in the path.
 257         let orig_inside_public_path = self.inside_public_path;
 258         self.inside_public_path &= vis.node.is_pub();
 259         for i in &m.item_ids {
 260             let item = self.cx.tcx.hir.expect_item(i.id);
 261             self.visit_item(item, None, &mut om);
 262         }
 263         self.inside_public_path = orig_inside_public_path;
 264         om
 265     }
 266
 267     /// Tries to resolve the target of a `pub use` statement and inlines the
 268     /// target if it is defined locally and would not be documented otherwise,
 269     /// or when it is specifically requested with `please_inline`.
 270     /// (the latter is the case when the import is marked `doc(inline)`)
 271     ///
 272     /// Cross-crate inlining occurs later on during crate cleaning
 273     /// and follows different rules.
 274     ///
 275     /// Returns true if the target has been inlined.
 276     fn maybe_inline_local(&mut self,
 277                           id: ast::NodeId,
 278                           def: Def,
 279                           renamed: Option<ast::Name>,
 280                           glob: bool,
 281                           om: &mut Module,
 282                           please_inline: bool) -> bool {
 283
 284         fn inherits_doc_hidden(cx: &core::DocContext, mut node: ast::NodeId) -> bool {
 285             while let Some(id) = cx.tcx.hir.get_enclosing_scope(node) {
 286                 node = id;
 287                 if cx.tcx.hir.attrs(node).lists("doc").has_word("hidden") {
 288                     return true;
 289                 }
 290                 if node == ast::CRATE_NODE_ID {
 291                     break;
 292                 }
 293             }
 294             false
 295         }
 296
 297         debug!("maybe_inline_local def: {:?}", def);
 298
 299         let tcx = self.cx.tcx;
 300         if def == Def::Err {
 301             return false;
 302         }
 303         let def_did = def.def_id();
 304
 305         let use_attrs = tcx.hir.attrs(id);
 306         // Don't inline doc(hidden) imports so they can be stripped at a later stage.
 307         let is_no_inline = use_attrs.lists("doc").has_word("no_inline") ||
 308                            use_attrs.lists("doc").has_word("hidden");
 309
 310         // For cross-crate impl inlining we need to know whether items are
 311         // reachable in documentation - a previously nonreachable item can be
 312         // made reachable by cross-crate inlining which we're checking here.
 313         // (this is done here because we need to know this upfront)
 314         if !def_did.is_local() && !is_no_inline {
 315             let attrs = clean::inline::load_attrs(self.cx, def_did);
 316             let self_is_hidden = attrs.lists("doc").has_word("hidden");
 317             match def {
 318                 Def::Trait(did) |
 319                 Def::Struct(did) |
 320                 Def::Union(did) |
 321                 Def::Enum(did) |
 322                 Def::ForeignTy(did) |
 323                 Def::TyAlias(did) if !self_is_hidden => {
 324                     self.cx.renderinfo
 325                         .borrow_mut()
 326                         .access_levels.map
 327                         .insert(did, AccessLevel::Public);
 328                 },
 329                 Def::Mod(did) => if !self_is_hidden {
 330                     ::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did);
 331                 },
 332                 _ => {},
 333             }
 334
 335             return false
 336         }
 337
 338         let def_node_id = match tcx.hir.as_local_node_id(def_did) {
 339             Some(n) => n, None => return false
 340         };
 341
 342         let is_private = !self.cx.renderinfo.borrow().access_levels.is_public(def_did);
 343         let is_hidden = inherits_doc_hidden(self.cx, def_node_id);
 344
 345         // Only inline if requested or if the item would otherwise be stripped
 346         if (!please_inline && !is_private && !is_hidden) || is_no_inline {
 347             return false
 348         }
 349
 350         if !self.view_item_stack.insert(def_node_id) { return false }
 351
 352         let ret = match tcx.hir.get(def_node_id) {
 353             Node::Item(&hir::Item { node: hir::ItemKind::Mod(ref m), .. }) if glob => {
 354                 let prev = mem::replace(&mut self.inlining, true);
 355                 for i in &m.item_ids {
 356                     let i = self.cx.tcx.hir.expect_item(i.id);
 357                     self.visit_item(i, None, om);
 358                 }
 359                 self.inlining = prev;
 360                 true
 361             }
 362             Node::Item(it) if !glob => {
 363                 let prev = mem::replace(&mut self.inlining, true);
 364                 self.visit_item(it, renamed, om);
 365                 self.inlining = prev;
 366                 true
 367             }
 368             Node::ForeignItem(it) if !glob => {
 369                 // generate a fresh `extern {}` block if we want to inline a foreign item.
 370                 om.foreigns.push(hir::ForeignMod {
 371                     abi: tcx.hir.get_foreign_abi(it.id),
 372                     items: vec![hir::ForeignItem {
 373                         name: renamed.unwrap_or(it.name),
 374                         .. it.clone()
 375                     }].into(),
 376                 });
 377                 true
 378             }
 379             _ => false,
 380         };
 381         self.view_item_stack.remove(&def_node_id);
 382         ret
 383     }
 384
 385     pub fn visit_item(&mut self, item: &hir::Item,
 386                       renamed: Option<ast::Name>, om: &mut Module) {
 387         debug!("Visiting item {:?}", item);
 388         let name = renamed.unwrap_or(item.name);
 389
 390         if item.vis.node.is_pub() {
 391             let def_id = self.cx.tcx.hir.local_def_id(item.id);
 392             self.store_path(def_id);
 393         }
 394
 395         match item.node {
 396             hir::ItemKind::ForeignMod(ref fm) => {
 397                 // If inlining we only want to include public functions.
 398                 om.foreigns.push(if self.inlining {
 399                     hir::ForeignMod {
 400                         abi: fm.abi,
 401                         items: fm.items.iter().filter(|i| i.vis.node.is_pub()).cloned().collect(),
 402                     }
 403                 } else {
 404                     fm.clone()
 405                 });
 406             }
 407             // If we're inlining, skip private items.
 408             _ if self.inlining && !item.vis.node.is_pub() => {}
 409             hir::ItemKind::GlobalAsm(..) => {}
 410             hir::ItemKind::ExternCrate(orig_name) => {
 411                 let def_id = self.cx.tcx.hir.local_def_id(item.id);
 412                 om.extern_crates.push(ExternCrate {
 413                     cnum: self.cx.tcx.extern_mod_stmt_cnum(def_id)
 414                                 .unwrap_or(LOCAL_CRATE),
 415                     name,
 416                     path: orig_name.map(|x|x.to_string()),
 417                     vis: item.vis.clone(),
 418                     attrs: item.attrs.clone(),
 419                     whence: item.span,
 420                 })
 421             }
 422             hir::ItemKind::Use(_, hir::UseKind::ListStem) => {}
 423             hir::ItemKind::Use(ref path, kind) => {
 424                 let is_glob = kind == hir::UseKind::Glob;
 425
 426                 // struct and variant constructors always show up alongside their definitions, we've
 427                 // already processed them so just discard these.
 428                 match path.def {
 429                     Def::StructCtor(..) | Def::VariantCtor(..) | Def::SelfCtor(..) => return,
 430                     _ => {}
 431                 }
 432
 433                 // If there was a private module in the current path then don't bother inlining
 434                 // anything as it will probably be stripped anyway.
 435                 if item.vis.node.is_pub() && self.inside_public_path {
 436                     let please_inline = item.attrs.iter().any(|item| {
 437                         match item.meta_item_list() {
 438                             Some(ref list) if item.check_name("doc") => {
 439                                 list.iter().any(|i| i.check_name("inline"))
 440                             }
 441                             _ => false,
 442                         }
 443                     });
 444                     let name = if is_glob { None } else { Some(name) };
 445                     if self.maybe_inline_local(item.id,
 446                                                path.def,
 447                                                name,
 448                                                is_glob,
 449                                                om,
 450                                                please_inline) {
 451                         return;
 452                     }
 453                 }
 454
 455                 om.imports.push(Import {
 456                     name,
 457                     id: item.id,
 458                     vis: item.vis.clone(),
 459                     attrs: item.attrs.clone(),
 460                     path: (**path).clone(),
 461                     glob: is_glob,
 462                     whence: item.span,
 463                 });
 464             }
 465             hir::ItemKind::Mod(ref m) => {
 466                 om.mods.push(self.visit_mod_contents(item.span,
 467                                                      item.attrs.clone(),
 468                                                      item.vis.clone(),
 469                                                      item.id,
 470                                                      m,
 471                                                      Some(name)));
 472             },
 473             hir::ItemKind::Enum(ref ed, ref gen) =>
 474                 om.enums.push(self.visit_enum_def(item, name, ed, gen)),
 475             hir::ItemKind::Struct(ref sd, ref gen) =>
 476                 om.structs.push(self.visit_variant_data(item, name, sd, gen)),
 477             hir::ItemKind::Union(ref sd, ref gen) =>
 478                 om.unions.push(self.visit_union_data(item, name, sd, gen)),
 479             hir::ItemKind::Fn(ref fd, header, ref gen, body) =>
 480                 self.visit_fn(om, item, name, &**fd, header, gen, body),
 481             hir::ItemKind::Ty(ref ty, ref gen) => {
 482                 let t = Typedef {
 483                     ty: ty.clone(),
 484                     gen: gen.clone(),
 485                     name,
 486                     id: item.id,
 487                     attrs: item.attrs.clone(),
 488                     whence: item.span,
 489                     vis: item.vis.clone(),
 490                     stab: self.stability(item.id),
 491                     depr: self.deprecation(item.id),
 492                 };
 493                 om.typedefs.push(t);
 494             },
 495             hir::ItemKind::Existential(ref exist_ty) => {
 496                 let t = Existential {
 497                     exist_ty: exist_ty.clone(),
 498                     name,
 499                     id: item.id,
 500                     attrs: item.attrs.clone(),
 501                     whence: item.span,
 502                     vis: item.vis.clone(),
 503                     stab: self.stability(item.id),
 504                     depr: self.deprecation(item.id),
 505                 };
 506                 om.existentials.push(t);
 507             },
 508             hir::ItemKind::Static(ref ty, ref mut_, ref exp) => {
 509                 let s = Static {
 510                     type_: ty.clone(),
 511                     mutability: mut_.clone(),
 512                     expr: exp.clone(),
 513                     id: item.id,
 514                     name,
 515                     attrs: item.attrs.clone(),
 516                     whence: item.span,
 517                     vis: item.vis.clone(),
 518                     stab: self.stability(item.id),
 519                     depr: self.deprecation(item.id),
 520                 };
 521                 om.statics.push(s);
 522             },
 523             hir::ItemKind::Const(ref ty, ref exp) => {
 524                 let s = Constant {
 525                     type_: ty.clone(),
 526                     expr: exp.clone(),
 527                     id: item.id,
 528                     name,
 529                     attrs: item.attrs.clone(),
 530                     whence: item.span,
 531                     vis: item.vis.clone(),
 532                     stab: self.stability(item.id),
 533                     depr: self.deprecation(item.id),
 534                 };
 535                 om.constants.push(s);
 536             },
 537             hir::ItemKind::Trait(is_auto, unsafety, ref gen, ref b, ref item_ids) => {
 538                 let items = item_ids.iter()
 539                                     .map(|ti| self.cx.tcx.hir.trait_item(ti.id).clone())
 540                                     .collect();
 541                 let t = Trait {
 542                     is_auto,
 543                     unsafety,
 544                     name,
 545                     items,
 546                     generics: gen.clone(),
 547                     bounds: b.iter().cloned().collect(),
 548                     id: item.id,
 549                     attrs: item.attrs.clone(),
 550                     whence: item.span,
 551                     vis: item.vis.clone(),
 552                     stab: self.stability(item.id),
 553                     depr: self.deprecation(item.id),
 554                 };
 555                 om.traits.push(t);
 556             },
 557             hir::ItemKind::TraitAlias(..) => {
 558                 unimplemented!("trait objects are not yet implemented")
 559             },
 560
 561             hir::ItemKind::Impl(unsafety,
 562                           polarity,
 563                           defaultness,
 564                           ref gen,
 565                           ref tr,
 566                           ref ty,
 567                           ref item_ids) => {
 568                 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
 569                 // them up regardless of where they're located.
 570                 if !self.inlining && tr.is_none() {
 571                     let items = item_ids.iter()
 572                                         .map(|ii| self.cx.tcx.hir.impl_item(ii.id).clone())
 573                                         .collect();
 574                     let i = Impl {
 575                         unsafety,
 576                         polarity,
 577                         defaultness,
 578                         generics: gen.clone(),
 579                         trait_: tr.clone(),
 580                         for_: ty.clone(),
 581                         items,
 582                         attrs: item.attrs.clone(),
 583                         id: item.id,
 584                         whence: item.span,
 585                         vis: item.vis.clone(),
 586                         stab: self.stability(item.id),
 587                         depr: self.deprecation(item.id),
 588                     };
 589                     om.impls.push(i);
 590                 }
 591             },
 592         }
 593     }
 594
 595     // convert each exported_macro into a doc item
 596     fn visit_local_macro(&self, def: &hir::MacroDef) -> Macro {
 597         debug!("visit_local_macro: {}", def.name);
 598         let tts = def.body.trees().collect::<Vec<_>>();
 599         // Extract the spans of all matchers. They represent the "interface" of the macro.
 600         let matchers = tts.chunks(4).map(|arm| arm[0].span()).collect();
 601
 602         Macro {
 603             def_id: self.cx.tcx.hir.local_def_id(def.id),
 604             attrs: def.attrs.clone(),
 605             name: def.name,
 606             whence: def.span,
 607             matchers,
 608             stab: self.stability(def.id),
 609             depr: self.deprecation(def.id),
 610             imported_from: None,
 611         }
 612     }
 613 }