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, CrateStore};
  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     cstore: &'tcx CrateStore,
  44     pub module: Module,
  45     pub attrs: hir::HirVec<ast::Attribute>,
  46     pub cx: &'a core::DocContext<'a, 'tcx>,
  47     view_item_stack: FxHashSet<ast::NodeId>,
  48     inlining: bool,
  49     /// Is the current module and all of its parents public?
  50     inside_public_path: bool,
  51     reexported_macros: FxHashSet<DefId>,
  52 }
  53
  54 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
  55     pub fn new(cstore: &'tcx CrateStore,
  56                cx: &'a core::DocContext<'a, 'tcx>) -> RustdocVisitor<'a, 'tcx> {
  57         // If the root is reexported, terminate all recursion.
  58         let mut stack = FxHashSet();
  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             reexported_macros: FxHashSet(),
  68             cstore,
  69         }
  70     }
  71
  72     fn stability(&self, id: ast::NodeId) -> Option<attr::Stability> {
  73         self.cx.tcx.hir.opt_local_def_id(id)
  74             .and_then(|def_id| self.cx.tcx.lookup_stability(def_id)).cloned()
  75     }
  76
  77     fn deprecation(&self, id: ast::NodeId) -> Option<attr::Deprecation> {
  78         self.cx.tcx.hir.opt_local_def_id(id)
  79             .and_then(|def_id| self.cx.tcx.lookup_deprecation(def_id))
  80     }
  81
  82     pub fn visit(&mut self, krate: &hir::Crate) {
  83         self.attrs = krate.attrs.clone();
  84
  85         self.module = self.visit_mod_contents(krate.span,
  86                                               krate.attrs.clone(),
  87                                               hir::Public,
  88                                               ast::CRATE_NODE_ID,
  89                                               &krate.module,
  90                                               None);
  91         // attach the crate's exported macros to the top-level module:
  92         let macro_exports: Vec<_> =
  93             krate.exported_macros.iter().map(|def| self.visit_local_macro(def)).collect();
  94         self.module.macros.extend(macro_exports);
  95         self.module.is_crate = true;
  96     }
  97
  98     pub fn visit_variant_data(&mut self, item: &hir::Item,
  99                             name: ast::Name, sd: &hir::VariantData,
 100                             generics: &hir::Generics) -> Struct {
 101         debug!("Visiting struct");
 102         let struct_type = struct_type_from_def(&*sd);
 103         Struct {
 104             id: item.id,
 105             struct_type,
 106             name,
 107             vis: item.vis.clone(),
 108             stab: self.stability(item.id),
 109             depr: self.deprecation(item.id),
 110             attrs: item.attrs.clone(),
 111             generics: generics.clone(),
 112             fields: sd.fields().iter().cloned().collect(),
 113             whence: item.span
 114         }
 115     }
 116
 117     pub fn visit_union_data(&mut self, item: &hir::Item,
 118                             name: ast::Name, sd: &hir::VariantData,
 119                             generics: &hir::Generics) -> Union {
 120         debug!("Visiting union");
 121         let struct_type = struct_type_from_def(&*sd);
 122         Union {
 123             id: item.id,
 124             struct_type,
 125             name,
 126             vis: item.vis.clone(),
 127             stab: self.stability(item.id),
 128             depr: self.deprecation(item.id),
 129             attrs: item.attrs.clone(),
 130             generics: generics.clone(),
 131             fields: sd.fields().iter().cloned().collect(),
 132             whence: item.span
 133         }
 134     }
 135
 136     pub fn visit_enum_def(&mut self, it: &hir::Item,
 137                           name: ast::Name, def: &hir::EnumDef,
 138                           params: &hir::Generics) -> Enum {
 139         debug!("Visiting enum");
 140         Enum {
 141             name,
 142             variants: def.variants.iter().map(|v| Variant {
 143                 name: v.node.name,
 144                 attrs: v.node.attrs.clone(),
 145                 stab: self.stability(v.node.data.id()),
 146                 depr: self.deprecation(v.node.data.id()),
 147                 def: v.node.data.clone(),
 148                 whence: v.span,
 149             }).collect(),
 150             vis: it.vis.clone(),
 151             stab: self.stability(it.id),
 152             depr: self.deprecation(it.id),
 153             generics: params.clone(),
 154             attrs: it.attrs.clone(),
 155             id: it.id,
 156             whence: it.span,
 157         }
 158     }
 159
 160     pub fn visit_fn(&mut self, item: &hir::Item,
 161                     name: ast::Name, fd: &hir::FnDecl,
 162                     unsafety: &hir::Unsafety,
 163                     constness: hir::Constness,
 164                     abi: &abi::Abi,
 165                     gen: &hir::Generics,
 166                     body: hir::BodyId) -> Function {
 167         debug!("Visiting fn");
 168         Function {
 169             id: item.id,
 170             vis: item.vis.clone(),
 171             stab: self.stability(item.id),
 172             depr: self.deprecation(item.id),
 173             attrs: item.attrs.clone(),
 174             decl: fd.clone(),
 175             name,
 176             whence: item.span,
 177             generics: gen.clone(),
 178             unsafety: *unsafety,
 179             constness,
 180             abi: *abi,
 181             body,
 182         }
 183     }
 184
 185     pub fn visit_mod_contents(&mut self, span: Span, attrs: hir::HirVec<ast::Attribute>,
 186                               vis: hir::Visibility, id: ast::NodeId,
 187                               m: &hir::Mod,
 188                               name: Option<ast::Name>) -> Module {
 189         let mut om = Module::new(name);
 190         om.where_outer = span;
 191         om.where_inner = m.inner;
 192         om.attrs = attrs;
 193         om.vis = vis.clone();
 194         om.stab = self.stability(id);
 195         om.depr = self.deprecation(id);
 196         om.id = id;
 197         // Keep track of if there were any private modules in the path.
 198         let orig_inside_public_path = self.inside_public_path;
 199         self.inside_public_path &= vis == hir::Public;
 200         for i in &m.item_ids {
 201             let item = self.cx.tcx.hir.expect_item(i.id);
 202             self.visit_item(item, None, &mut om);
 203         }
 204         self.inside_public_path = orig_inside_public_path;
 205         let def_id = self.cx.tcx.hir.local_def_id(id);
 206         if let Some(exports) = self.cx.tcx.module_exports(def_id) {
 207             for export in exports.iter() {
 208                 if let Def::Macro(def_id, ..) = export.def {
 209                     if def_id.krate == LOCAL_CRATE || self.reexported_macros.contains(&def_id) {
 210                         continue // These are `krate.exported_macros`, handled in `self.visit()`.
 211                     }
 212
 213                     let imported_from = self.cx.tcx.original_crate_name(def_id.krate);
 214                     let def = match self.cstore.load_macro_untracked(def_id, self.cx.sess()) {
 215                         LoadedMacro::MacroDef(macro_def) => macro_def,
 216                         // FIXME(jseyfried): document proc macro reexports
 217                         LoadedMacro::ProcMacro(..) => continue,
 218                     };
 219
 220                     let matchers = if let ast::ItemKind::MacroDef(ref def) = def.node {
 221                         let tts: Vec<_> = def.stream().into_trees().collect();
 222                         tts.chunks(4).map(|arm| arm[0].span()).collect()
 223                     } else {
 224                         unreachable!()
 225                     };
 226
 227                     om.macros.push(Macro {
 228                         def_id,
 229                         attrs: def.attrs.clone().into(),
 230                         name: def.ident.name,
 231                         whence: def.span,
 232                         matchers,
 233                         stab: self.stability(def.id),
 234                         depr: self.deprecation(def.id),
 235                         imported_from: Some(imported_from),
 236                     })
 237                 }
 238             }
 239         }
 240         om
 241     }
 242
 243     /// Tries to resolve the target of a `pub use` statement and inlines the
 244     /// target if it is defined locally and would not be documented otherwise,
 245     /// or when it is specifically requested with `please_inline`.
 246     /// (the latter is the case when the import is marked `doc(inline)`)
 247     ///
 248     /// Cross-crate inlining occurs later on during crate cleaning
 249     /// and follows different rules.
 250     ///
 251     /// Returns true if the target has been inlined.
 252     fn maybe_inline_local(&mut self,
 253                           id: ast::NodeId,
 254                           def: Def,
 255                           renamed: Option<ast::Name>,
 256                           glob: bool,
 257                           om: &mut Module,
 258                           please_inline: bool) -> bool {
 259
 260         fn inherits_doc_hidden(cx: &core::DocContext, mut node: ast::NodeId) -> bool {
 261             while let Some(id) = cx.tcx.hir.get_enclosing_scope(node) {
 262                 node = id;
 263                 if cx.tcx.hir.attrs(node).lists("doc").has_word("hidden") {
 264                     return true;
 265                 }
 266                 if node == ast::CRATE_NODE_ID {
 267                     break;
 268                 }
 269             }
 270             false
 271         }
 272
 273         debug!("maybe_inline_local def: {:?}", def);
 274
 275         let tcx = self.cx.tcx;
 276         if def == Def::Err {
 277             return false;
 278         }
 279         let def_did = def.def_id();
 280
 281         let use_attrs = tcx.hir.attrs(id);
 282         // Don't inline doc(hidden) imports so they can be stripped at a later stage.
 283         let is_no_inline = use_attrs.lists("doc").has_word("no_inline") ||
 284                            use_attrs.lists("doc").has_word("hidden");
 285
 286         // Memoize the non-inlined `pub use`'d macros so we don't push an extra
 287         // declaration in `visit_mod_contents()`
 288         if !def_did.is_local() {
 289             if let Def::Macro(did, _) = def {
 290                 if please_inline { return true }
 291                 debug!("memoizing non-inlined macro export: {:?}", def);
 292                 self.reexported_macros.insert(did);
 293                 return false;
 294             }
 295         }
 296
 297         // For cross-crate impl inlining we need to know whether items are
 298         // reachable in documentation - a previously nonreachable item can be
 299         // made reachable by cross-crate inlining which we're checking here.
 300         // (this is done here because we need to know this upfront)
 301         if !def_did.is_local() && !is_no_inline {
 302             let attrs = clean::inline::load_attrs(self.cx, def_did);
 303             let self_is_hidden = attrs.lists("doc").has_word("hidden");
 304             match def {
 305                 Def::Trait(did) |
 306                 Def::Struct(did) |
 307                 Def::Union(did) |
 308                 Def::Enum(did) |
 309                 Def::TyAlias(did) if !self_is_hidden => {
 310                     self.cx.access_levels.borrow_mut().map.insert(did, AccessLevel::Public);
 311                 },
 312                 Def::Mod(did) => if !self_is_hidden {
 313                     ::visit_lib::LibEmbargoVisitor::new(self.cx).visit_mod(did);
 314                 },
 315                 _ => {},
 316             }
 317
 318             return false
 319         }
 320
 321         let def_node_id = match tcx.hir.as_local_node_id(def_did) {
 322             Some(n) => n, None => return false
 323         };
 324
 325         let is_private = !self.cx.access_levels.borrow().is_public(def_did);
 326         let is_hidden = inherits_doc_hidden(self.cx, def_node_id);
 327
 328         // Only inline if requested or if the item would otherwise be stripped
 329         if (!please_inline && !is_private && !is_hidden) || is_no_inline {
 330             return false
 331         }
 332
 333         if !self.view_item_stack.insert(def_node_id) { return false }
 334
 335         let ret = match tcx.hir.get(def_node_id) {
 336             hir_map::NodeItem(&hir::Item { node: hir::ItemMod(ref m), .. }) if glob => {
 337                 let prev = mem::replace(&mut self.inlining, true);
 338                 for i in &m.item_ids {
 339                     let i = self.cx.tcx.hir.expect_item(i.id);
 340                     self.visit_item(i, None, om);
 341                 }
 342                 self.inlining = prev;
 343                 true
 344             }
 345             hir_map::NodeItem(it) if !glob => {
 346                 let prev = mem::replace(&mut self.inlining, true);
 347                 self.visit_item(it, renamed, om);
 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 def_id = self.cx.tcx.hir.local_def_id(item.id);
 378                 om.extern_crates.push(ExternCrate {
 379                     cnum: self.cx.tcx.extern_mod_stmt_cnum(def_id)
 380                                 .unwrap_or(LOCAL_CRATE),
 381                     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,
 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,
 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,
 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,
 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,
 490                     name,
 491                     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,
 519                         polarity,
 520                         defaultness,
 521                         generics: gen.clone(),
 522                         trait_: tr.clone(),
 523                         for_: ty.clone(),
 524                         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::ItemAutoImpl(unsafety, ref trait_ref) => {
 536                 // See comment above about ItemImpl.
 537                 if !self.inlining {
 538                     let i = AutoImpl {
 539                         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,
 563             stab: self.stability(def.id),
 564             depr: self.deprecation(def.id),
 565             imported_from: None,
 566         }
 567     }
 568 }