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::abi;
  17 use syntax::ast;
  18 use syntax::attr;
  19 use syntax_pos::Span;
  20
  21 use rustc::hir::map as hir_map;
  22 use rustc::hir::def::Def;
  23 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
  24 use rustc::middle::cstore::LoadedMacro;
  25 use rustc::middle::privacy::AccessLevel;
  26 use rustc::util::nodemap::FxHashSet;
  27
  28 use rustc::hir;
  29
  30 use core;
  31 use clean::{self, AttributesExt, NestedAttributesExt};
  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> {
  43     pub module: Module,
  44     pub attrs: hir::HirVec<ast::Attribute>,
  45     pub cx: &'a core::DocContext<'a, 'tcx>,
  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     reexported_macros: FxHashSet<DefId>,
  51 }
  52
  53 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
  54     pub fn new(cx: &'a core::DocContext<'a, 'tcx>) -> RustdocVisitor<'a, 'tcx> {
  55         // If the root is reexported, terminate all recursion.
  56         let mut stack = FxHashSet();
  57         stack.insert(ast::CRATE_NODE_ID);
  58         RustdocVisitor {
  59             module: Module::new(None),
  60             attrs: hir::HirVec::new(),
  61             cx: cx,
  62             view_item_stack: stack,
  63             inlining: false,
  64             inside_public_path: true,
  65             reexported_macros: FxHashSet(),
  66         }
  67     }
  68
  69     fn stability(&self, id: ast::NodeId) -> Option<attr::Stability> {
  70         self.cx.tcx.hir.opt_local_def_id(id)
  71             .and_then(|def_id| self.cx.tcx.lookup_stability(def_id)).cloned()
  72     }
  73
  74     fn deprecation(&self, id: ast::NodeId) -> Option<attr::Deprecation> {
  75         self.cx.tcx.hir.opt_local_def_id(id)
  76             .and_then(|def_id| self.cx.tcx.lookup_deprecation(def_id))
  77     }
  78
  79     pub fn visit(&mut self, krate: &hir::Crate) {
  80         self.attrs = krate.attrs.clone();
  81
  82         self.module = self.visit_mod_contents(krate.span,
  83                                               krate.attrs.clone(),
  84                                               hir::Public,
  85                                               ast::CRATE_NODE_ID,
  86                                               &krate.module,
  87                                               None);
  88         // attach the crate's exported macros to the top-level module:
  89         let macro_exports: Vec<_> =
  90             krate.exported_macros.iter().map(|def| self.visit_local_macro(def)).collect();
  91         self.module.macros.extend(macro_exports);
  92         self.module.is_crate = true;
  93     }
  94
  95     pub fn visit_variant_data(&mut self, item: &hir::Item,
  96                             name: ast::Name, sd: &hir::VariantData,
  97                             generics: &hir::Generics) -> Struct {
  98         debug!("Visiting struct");
  99         let struct_type = struct_type_from_def(&*sd);
 100         Struct {
 101             id: item.id,
 102             struct_type: struct_type,
 103             name: name,
 104             vis: item.vis.clone(),
 105             stab: self.stability(item.id),
 106             depr: self.deprecation(item.id),
 107             attrs: item.attrs.clone(),
 108             generics: generics.clone(),
 109             fields: sd.fields().iter().cloned().collect(),
 110             whence: item.span
 111         }
 112     }
 113
 114     pub fn visit_union_data(&mut self, item: &hir::Item,
 115                             name: ast::Name, sd: &hir::VariantData,
 116                             generics: &hir::Generics) -> Union {
 117         debug!("Visiting union");
 118         let struct_type = struct_type_from_def(&*sd);
 119         Union {
 120             id: item.id,
 121             struct_type: struct_type,
 122             name: name,
 123             vis: item.vis.clone(),
 124             stab: self.stability(item.id),
 125             depr: self.deprecation(item.id),
 126             attrs: item.attrs.clone(),
 127             generics: generics.clone(),
 128             fields: sd.fields().iter().cloned().collect(),
 129             whence: item.span
 130         }
 131     }
 132
 133     pub fn visit_enum_def(&mut self, it: &hir::Item,
 134                           name: ast::Name, def: &hir::EnumDef,
 135                           params: &hir::Generics) -> Enum {
 136         debug!("Visiting enum");
 137         Enum {
 138             name: name,
 139             variants: def.variants.iter().map(|v| Variant {
 140                 name: v.node.name,
 141                 attrs: v.node.attrs.clone(),
 142                 stab: self.stability(v.node.data.id()),
 143                 depr: self.deprecation(v.node.data.id()),
 144                 def: v.node.data.clone(),
 145                 whence: v.span,
 146             }).collect(),
 147             vis: it.vis.clone(),
 148             stab: self.stability(it.id),
 149             depr: self.deprecation(it.id),
 150             generics: params.clone(),
 151             attrs: it.attrs.clone(),
 152             id: it.id,
 153             whence: it.span,
 154         }
 155     }
 156
 157     pub fn visit_fn(&mut self, item: &hir::Item,
 158                     name: ast::Name, fd: &hir::FnDecl,
 159                     unsafety: &hir::Unsafety,
 160                     constness: hir::Constness,
 161                     abi: &abi::Abi,
 162                     gen: &hir::Generics,
 163                     body: hir::BodyId) -> Function {
 164         debug!("Visiting fn");
 165         Function {
 166             id: item.id,
 167             vis: item.vis.clone(),
 168             stab: self.stability(item.id),
 169             depr: self.deprecation(item.id),
 170             attrs: item.attrs.clone(),
 171             decl: fd.clone(),
 172             name: name,
 173             whence: item.span,
 174             generics: gen.clone(),
 175             unsafety: *unsafety,
 176             constness: constness,
 177             abi: *abi,
 178             body: body,
 179         }
 180     }
 181
 182     pub fn visit_mod_contents(&mut self, span: Span, attrs: hir::HirVec<ast::Attribute>,
 183                               vis: hir::Visibility, id: ast::NodeId,
 184                               m: &hir::Mod,
 185                               name: Option<ast::Name>) -> Module {
 186         let mut om = Module::new(name);
 187         om.where_outer = span;
 188         om.where_inner = m.inner;
 189         om.attrs = attrs;
 190         om.vis = vis.clone();
 191         om.stab = self.stability(id);
 192         om.depr = self.deprecation(id);
 193         om.id = id;
 194         // Keep track of if there were any private modules in the path.
 195         let orig_inside_public_path = self.inside_public_path;
 196         self.inside_public_path &= vis == hir::Public;
 197         for i in &m.item_ids {
 198             let item = self.cx.tcx.hir.expect_item(i.id);
 199             self.visit_item(item, None, &mut om);
 200         }
 201         self.inside_public_path = orig_inside_public_path;
 202         if let Some(exports) = self.cx.tcx.export_map.get(&id) {
 203             for export in exports {
 204                 if let Def::Macro(def_id, ..) = export.def {
 205                     if def_id.krate == LOCAL_CRATE || self.reexported_macros.contains(&def_id) {
 206                         continue // These are `krate.exported_macros`, handled in `self.visit()`.
 207                     }
 208
 209                     let imported_from = self.cx.sess().cstore.original_crate_name(def_id.krate);
 210                     let def = match self.cx.sess().cstore.load_macro(def_id, self.cx.sess()) {
 211                         LoadedMacro::MacroDef(macro_def) => macro_def,
 212                         // FIXME(jseyfried): document proc macro reexports
 213                         LoadedMacro::ProcMacro(..) => continue,
 214                     };
 215
 216                     let matchers = if let ast::ItemKind::MacroDef(ref def) = def.node {
 217                         let tts: Vec<_> = def.stream().into_trees().collect();
 218                         tts.chunks(4).map(|arm| arm[0].span()).collect()
 219                     } else {
 220                         unreachable!()
 221                     };
 222
 223                     om.macros.push(Macro {
 224                         def_id: def_id,
 225                         attrs: def.attrs.clone().into(),
 226                         name: def.ident.name,
 227                         whence: def.span,
 228                         matchers: matchers,
 229                         stab: self.stability(def.id),
 230                         depr: self.deprecation(def.id),
 231                         imported_from: Some(imported_from),
 232                     })
 233                 }
 234             }
 235         }
 236         om
 237     }
 238
 239     /// Tries to resolve the target of a `pub use` statement and inlines the
 240     /// target if it is defined locally and would not be documented otherwise,
 241     /// or when it is specifically requested with `please_inline`.
 242     /// (the latter is the case when the import is marked `doc(inline)`)
 243     ///
 244     /// Cross-crate inlining occurs later on during crate cleaning
 245     /// and follows different rules.
 246     ///
 247     /// Returns true if the target has been inlined.
 248     fn maybe_inline_local(&mut self,
 249                           id: ast::NodeId,
 250                           def: Def,
 251                           renamed: Option<ast::Name>,
 252                           glob: bool,
 253                           om: &mut Module,
 254                           please_inline: bool) -> bool {
 255
 256         fn inherits_doc_hidden(cx: &core::DocContext, mut node: ast::NodeId) -> bool {
 257             while let Some(id) = cx.tcx.hir.get_enclosing_scope(node) {
 258                 node = id;
 259                 if cx.tcx.hir.attrs(node).lists("doc").has_word("hidden") {
 260                     return true;
 261                 }
 262                 if node == ast::CRATE_NODE_ID {
 263                     break;
 264                 }
 265             }
 266             false
 267         }
 268
 269         debug!("maybe_inline_local def: {:?}", def);
 270
 271         let tcx = self.cx.tcx;
 272         if def == Def::Err {
 273             return false;
 274         }
 275         let def_did = def.def_id();
 276
 277         let use_attrs = tcx.hir.attrs(id);
 278         // Don't inline doc(hidden) imports so they can be stripped at a later stage.
 279         let is_no_inline = use_attrs.lists("doc").has_word("no_inline") ||
 280                            use_attrs.lists("doc").has_word("hidden");
 281
 282         // Memoize the non-inlined `pub use`'d macros so we don't push an extra
 283         // declaration in `visit_mod_contents()`
 284         if !def_did.is_local() {
 285             if let Def::Macro(did, _) = def {
 286                 if please_inline { return true }
 287                 debug!("memoizing non-inlined macro export: {:?}", def);
 288                 self.reexported_macros.insert(did);
 289                 return false;
 290             }
 291         }
 292
 293         // For cross-crate impl inlining we need to know whether items are
 294         // reachable in documentation - a previously nonreachable item can be
 295         // made reachable by cross-crate inlining which we're checking here.
 296         // (this is done here because we need to know this upfront)
 297         if !def_did.is_local() && !is_no_inline {
 298             let attrs = clean::inline::load_attrs(self.cx, def_did);
 299             let self_is_hidden = attrs.lists("doc").has_word("hidden");
 300             match def {
 301                 Def::Trait(did) |
 302                 Def::Struct(did) |
 303                 Def::Union(did) |
 304                 Def::Enum(did) |
 305                 Def::TyAlias(did) if !self_is_hidden => {
 306                     self.cx.access_levels.borrow_mut().map.insert(did, AccessLevel::Public);
 307                 },
 308                 Def::Mod(did) => if !self_is_hidden {
 309                     ::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did);
 310                 },
 311                 _ => {},
 312             }
 313
 314             return false
 315         }
 316
 317         let def_node_id = match tcx.hir.as_local_node_id(def_did) {
 318             Some(n) => n, None => return false
 319         };
 320
 321         let is_private = !self.cx.access_levels.borrow().is_public(def_did);
 322         let is_hidden = inherits_doc_hidden(self.cx, def_node_id);
 323
 324         // Only inline if requested or if the item would otherwise be stripped
 325         if (!please_inline && !is_private && !is_hidden) || is_no_inline {
 326             return false
 327         }
 328
 329         if !self.view_item_stack.insert(def_node_id) { return false }
 330
 331         let ret = match tcx.hir.get(def_node_id) {
 332             hir_map::NodeItem(it) => {
 333                 let prev = mem::replace(&mut self.inlining, true);
 334                 if glob {
 335                     match it.node {
 336                         hir::ItemMod(ref m) => {
 337                             for i in &m.item_ids {
 338                                 let i = self.cx.tcx.hir.expect_item(i.id);
 339                                 self.visit_item(i, None, om);
 340                             }
 341                         }
 342                         hir::ItemEnum(..) => {}
 343                         _ => { panic!("glob not mapped to a module or enum"); }
 344                     }
 345                 } else {
 346                     self.visit_item(it, renamed, om);
 347                 }
 348                 self.inlining = prev;
 349                 true
 350             }
 351             _ => false,
 352         };
 353         self.view_item_stack.remove(&def_node_id);
 354         ret
 355     }
 356
 357     pub fn visit_item(&mut self, item: &hir::Item,
 358                       renamed: Option<ast::Name>, om: &mut Module) {
 359         debug!("Visiting item {:?}", item);
 360         let name = renamed.unwrap_or(item.name);
 361         match item.node {
 362             hir::ItemForeignMod(ref fm) => {
 363                 // If inlining we only want to include public functions.
 364                 om.foreigns.push(if self.inlining {
 365                     hir::ForeignMod {
 366                         abi: fm.abi,
 367                         items: fm.items.iter().filter(|i| i.vis == hir::Public).cloned().collect(),
 368                     }
 369                 } else {
 370                     fm.clone()
 371                 });
 372             }
 373             // If we're inlining, skip private items.
 374             _ if self.inlining && item.vis != hir::Public => {}
 375             hir::ItemGlobalAsm(..) => {}
 376             hir::ItemExternCrate(ref p) => {
 377                 let cstore = &self.cx.sess().cstore;
 378                 om.extern_crates.push(ExternCrate {
 379                     cnum: cstore.extern_mod_stmt_cnum(item.id)
 380                                 .unwrap_or(LOCAL_CRATE),
 381                     name: name,
 382                     path: p.map(|x|x.to_string()),
 383                     vis: item.vis.clone(),
 384                     attrs: item.attrs.clone(),
 385                     whence: item.span,
 386                 })
 387             }
 388             hir::ItemUse(_, hir::UseKind::ListStem) => {}
 389             hir::ItemUse(ref path, kind) => {
 390                 let is_glob = kind == hir::UseKind::Glob;
 391
 392                 // If there was a private module in the current path then don't bother inlining
 393                 // anything as it will probably be stripped anyway.
 394                 if item.vis == hir::Public && self.inside_public_path {
 395                     let please_inline = item.attrs.iter().any(|item| {
 396                         match item.meta_item_list() {
 397                             Some(ref list) if item.check_name("doc") => {
 398                                 list.iter().any(|i| i.check_name("inline"))
 399                             }
 400                             _ => false,
 401                         }
 402                     });
 403                     let name = if is_glob { None } else { Some(name) };
 404                     if self.maybe_inline_local(item.id,
 405                                                path.def,
 406                                                name,
 407                                                is_glob,
 408                                                om,
 409                                                please_inline) {
 410                         return;
 411                     }
 412                 }
 413
 414                 om.imports.push(Import {
 415                     name: name,
 416                     id: item.id,
 417                     vis: item.vis.clone(),
 418                     attrs: item.attrs.clone(),
 419                     path: (**path).clone(),
 420                     glob: is_glob,
 421                     whence: item.span,
 422                 });
 423             }
 424             hir::ItemMod(ref m) => {
 425                 om.mods.push(self.visit_mod_contents(item.span,
 426                                                      item.attrs.clone(),
 427                                                      item.vis.clone(),
 428                                                      item.id,
 429                                                      m,
 430                                                      Some(name)));
 431             },
 432             hir::ItemEnum(ref ed, ref gen) =>
 433                 om.enums.push(self.visit_enum_def(item, name, ed, gen)),
 434             hir::ItemStruct(ref sd, ref gen) =>
 435                 om.structs.push(self.visit_variant_data(item, name, sd, gen)),
 436             hir::ItemUnion(ref sd, ref gen) =>
 437                 om.unions.push(self.visit_union_data(item, name, sd, gen)),
 438             hir::ItemFn(ref fd, ref unsafety, constness, ref abi, ref gen, body) =>
 439                 om.fns.push(self.visit_fn(item, name, &**fd, unsafety,
 440                                           constness, abi, gen, body)),
 441             hir::ItemTy(ref ty, ref gen) => {
 442                 let t = Typedef {
 443                     ty: ty.clone(),
 444                     gen: gen.clone(),
 445                     name: name,
 446                     id: item.id,
 447                     attrs: item.attrs.clone(),
 448                     whence: item.span,
 449                     vis: item.vis.clone(),
 450                     stab: self.stability(item.id),
 451                     depr: self.deprecation(item.id),
 452                 };
 453                 om.typedefs.push(t);
 454             },
 455             hir::ItemStatic(ref ty, ref mut_, ref exp) => {
 456                 let s = Static {
 457                     type_: ty.clone(),
 458                     mutability: mut_.clone(),
 459                     expr: exp.clone(),
 460                     id: item.id,
 461                     name: name,
 462                     attrs: item.attrs.clone(),
 463                     whence: item.span,
 464                     vis: item.vis.clone(),
 465                     stab: self.stability(item.id),
 466                     depr: self.deprecation(item.id),
 467                 };
 468                 om.statics.push(s);
 469             },
 470             hir::ItemConst(ref ty, ref exp) => {
 471                 let s = Constant {
 472                     type_: ty.clone(),
 473                     expr: exp.clone(),
 474                     id: item.id,
 475                     name: name,
 476                     attrs: item.attrs.clone(),
 477                     whence: item.span,
 478                     vis: item.vis.clone(),
 479                     stab: self.stability(item.id),
 480                     depr: self.deprecation(item.id),
 481                 };
 482                 om.constants.push(s);
 483             },
 484             hir::ItemTrait(unsafety, ref gen, ref b, ref item_ids) => {
 485                 let items = item_ids.iter()
 486                                     .map(|ti| self.cx.tcx.hir.trait_item(ti.id).clone())
 487                                     .collect();
 488                 let t = Trait {
 489                     unsafety: unsafety,
 490                     name: name,
 491                     items: items,
 492                     generics: gen.clone(),
 493                     bounds: b.iter().cloned().collect(),
 494                     id: item.id,
 495                     attrs: item.attrs.clone(),
 496                     whence: item.span,
 497                     vis: item.vis.clone(),
 498                     stab: self.stability(item.id),
 499                     depr: self.deprecation(item.id),
 500                 };
 501                 om.traits.push(t);
 502             },
 503
 504             hir::ItemImpl(unsafety,
 505                           polarity,
 506                           defaultness,
 507                           ref gen,
 508                           ref tr,
 509                           ref ty,
 510                           ref item_ids) => {
 511                 // Don't duplicate impls when inlining, we'll pick them up
 512                 // regardless of where they're located.
 513                 if !self.inlining {
 514                     let items = item_ids.iter()
 515                                         .map(|ii| self.cx.tcx.hir.impl_item(ii.id).clone())
 516                                         .collect();
 517                     let i = Impl {
 518                         unsafety: unsafety,
 519                         polarity: polarity,
 520                         defaultness: defaultness,
 521                         generics: gen.clone(),
 522                         trait_: tr.clone(),
 523                         for_: ty.clone(),
 524                         items: items,
 525                         attrs: item.attrs.clone(),
 526                         id: item.id,
 527                         whence: item.span,
 528                         vis: item.vis.clone(),
 529                         stab: self.stability(item.id),
 530                         depr: self.deprecation(item.id),
 531                     };
 532                     om.impls.push(i);
 533                 }
 534             },
 535             hir::ItemDefaultImpl(unsafety, ref trait_ref) => {
 536                 // See comment above about ItemImpl.
 537                 if !self.inlining {
 538                     let i = DefaultImpl {
 539                         unsafety: unsafety,
 540                         trait_: trait_ref.clone(),
 541                         id: item.id,
 542                         attrs: item.attrs.clone(),
 543                         whence: item.span,
 544                     };
 545                     om.def_traits.push(i);
 546                 }
 547             }
 548         }
 549     }
 550
 551     // convert each exported_macro into a doc item
 552     fn visit_local_macro(&self, def: &hir::MacroDef) -> Macro {
 553         let tts = def.body.trees().collect::<Vec<_>>();
 554         // Extract the spans of all matchers. They represent the "interface" of the macro.
 555         let matchers = tts.chunks(4).map(|arm| arm[0].span()).collect();
 556
 557         Macro {
 558             def_id: self.cx.tcx.hir.local_def_id(def.id),
 559             attrs: def.attrs.clone(),
 560             name: def.name,
 561             whence: def.span,
 562             matchers: matchers,
 563             stab: self.stability(def.id),
 564             depr: self.deprecation(def.id),
 565             imported_from: None,
 566         }
 567     }
 568 }