compiler/rustc_save_analysis/src/dump_visitor.rs

   1 //! Write the output of rustc's analysis to an implementor of Dump.
   2 //!
   3 //! Dumping the analysis is implemented by walking the AST and getting a bunch of
   4 //! info out from all over the place. We use `DefId`s to identify objects. The
   5 //! tricky part is getting syntactic (span, source text) and semantic (reference
   6 //! `DefId`s) information for parts of expressions which the compiler has discarded.
   7 //! E.g., in a path `foo::bar::baz`, the compiler only keeps a span for the whole
   8 //! path and a reference to `baz`, but we want spans and references for all three
   9 //! idents.
  10 //!
  11 //! SpanUtils is used to manipulate spans. In particular, to extract sub-spans
  12 //! from spans (e.g., the span for `bar` from the above example path).
  13 //! DumpVisitor walks the AST and processes it, and Dumper is used for
  14 //! recording the output.
  15
  16 use rustc_ast as ast;
  17 use rustc_ast::walk_list;
  18 use rustc_data_structures::fx::FxHashSet;
  19 use rustc_hir as hir;
  20 use rustc_hir::def::{DefKind as HirDefKind, Res};
  21 use rustc_hir::def_id::{DefId, LocalDefId};
  22 use rustc_hir::intravisit::{self, Visitor};
  23 use rustc_hir_pretty::{bounds_to_string, fn_to_string, generic_params_to_string, ty_to_string};
  24 use rustc_middle::hir::map::Map;
  25 use rustc_middle::span_bug;
  26 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
  27 use rustc_session::config::Input;
  28 use rustc_span::source_map::respan;
  29 use rustc_span::symbol::Ident;
  30 use rustc_span::*;
  31
  32 use std::env;
  33 use std::path::Path;
  34
  35 use crate::dumper::{Access, Dumper};
  36 use crate::sig;
  37 use crate::span_utils::SpanUtils;
  38 use crate::{
  39     escape, generated_code, id_from_def_id, id_from_hir_id, lower_attributes, PathCollector,
  40     SaveContext,
  41 };
  42
  43 use rls_data::{
  44     CompilationOptions, CratePreludeData, Def, DefKind, GlobalCrateId, Import, ImportKind, Ref,
  45     RefKind, Relation, RelationKind, SpanData,
  46 };
  47
  48 use tracing::{debug, error};
  49
  50 macro_rules! down_cast_data {
  51     ($id:ident, $kind:ident, $sp:expr) => {
  52         let $id = if let super::Data::$kind(data) = $id {
  53             data
  54         } else {
  55             span_bug!($sp, "unexpected data kind: {:?}", $id);
  56         };
  57     };
  58 }
  59
  60 macro_rules! access_from {
  61     ($save_ctxt:expr, $item:expr, $id:expr) => {
  62         Access {
  63             public: $item.vis.node.is_pub(),
  64             reachable: $save_ctxt.access_levels.is_reachable($id),
  65         }
  66     };
  67 }
  68
  69 macro_rules! access_from_vis {
  70     ($save_ctxt:expr, $vis:expr, $id:expr) => {
  71         Access { public: $vis.node.is_pub(), reachable: $save_ctxt.access_levels.is_reachable($id) }
  72     };
  73 }
  74
  75 pub struct DumpVisitor<'tcx> {
  76     pub save_ctxt: SaveContext<'tcx>,
  77     tcx: TyCtxt<'tcx>,
  78     dumper: Dumper,
  79
  80     span: SpanUtils<'tcx>,
  81     // Set of macro definition (callee) spans, and the set
  82     // of macro use (callsite) spans. We store these to ensure
  83     // we only write one macro def per unique macro definition, and
  84     // one macro use per unique callsite span.
  85     // mac_defs: FxHashSet<Span>,
  86     // macro_calls: FxHashSet<Span>,
  87 }
  88
  89 impl<'tcx> DumpVisitor<'tcx> {
  90     pub fn new(save_ctxt: SaveContext<'tcx>) -> DumpVisitor<'tcx> {
  91         let span_utils = SpanUtils::new(&save_ctxt.tcx.sess);
  92         let dumper = Dumper::new(save_ctxt.config.clone());
  93         DumpVisitor {
  94             tcx: save_ctxt.tcx,
  95             save_ctxt,
  96             dumper,
  97             span: span_utils,
  98             // mac_defs: FxHashSet::default(),
  99             // macro_calls: FxHashSet::default(),
 100         }
 101     }
 102
 103     pub fn analysis(&self) -> &rls_data::Analysis {
 104         self.dumper.analysis()
 105     }
 106
 107     fn nest_typeck_results<F>(&mut self, item_def_id: LocalDefId, f: F)
 108     where
 109         F: FnOnce(&mut Self),
 110     {
 111         let typeck_results = if self.tcx.has_typeck_results(item_def_id) {
 112             Some(self.tcx.typeck(item_def_id))
 113         } else {
 114             None
 115         };
 116
 117         let old_maybe_typeck_results = self.save_ctxt.maybe_typeck_results;
 118         self.save_ctxt.maybe_typeck_results = typeck_results;
 119         f(self);
 120         self.save_ctxt.maybe_typeck_results = old_maybe_typeck_results;
 121     }
 122
 123     fn span_from_span(&self, span: Span) -> SpanData {
 124         self.save_ctxt.span_from_span(span)
 125     }
 126
 127     fn lookup_def_id(&self, ref_id: hir::HirId) -> Option<DefId> {
 128         self.save_ctxt.lookup_def_id(ref_id)
 129     }
 130
 131     pub fn dump_crate_info(&mut self, name: &str, krate: &hir::Crate<'_>) {
 132         let source_file = self.tcx.sess.local_crate_source_file.as_ref();
 133         let crate_root = source_file.map(|source_file| {
 134             let source_file = Path::new(source_file);
 135             match source_file.file_name() {
 136                 Some(_) => source_file.parent().unwrap().display(),
 137                 None => source_file.display(),
 138             }
 139             .to_string()
 140         });
 141
 142         let data = CratePreludeData {
 143             crate_id: GlobalCrateId {
 144                 name: name.into(),
 145                 disambiguator: self
 146                     .tcx
 147                     .sess
 148                     .local_crate_disambiguator()
 149                     .to_fingerprint()
 150                     .as_value(),
 151             },
 152             crate_root: crate_root.unwrap_or_else(|| "<no source>".to_owned()),
 153             external_crates: self.save_ctxt.get_external_crates(),
 154             span: self.span_from_span(krate.item.inner),
 155         };
 156
 157         self.dumper.crate_prelude(data);
 158     }
 159
 160     pub fn dump_compilation_options(&mut self, input: &Input, crate_name: &str) {
 161         // Apply possible `remap-path-prefix` remapping to the input source file
 162         // (and don't include remapping args anymore)
 163         let (program, arguments) = {
 164             let remap_arg_indices = {
 165                 let mut indices = FxHashSet::default();
 166                 // Args are guaranteed to be valid UTF-8 (checked early)
 167                 for (i, e) in env::args().enumerate() {
 168                     if e.starts_with("--remap-path-prefix=") {
 169                         indices.insert(i);
 170                     } else if e == "--remap-path-prefix" {
 171                         indices.insert(i);
 172                         indices.insert(i + 1);
 173                     }
 174                 }
 175                 indices
 176             };
 177
 178             let mut args = env::args()
 179                 .enumerate()
 180                 .filter(|(i, _)| !remap_arg_indices.contains(i))
 181                 .map(|(_, arg)| match input {
 182                     Input::File(ref path) if path == Path::new(&arg) => {
 183                         let mapped = &self.tcx.sess.local_crate_source_file;
 184                         mapped.as_ref().unwrap().to_string_lossy().into()
 185                     }
 186                     _ => arg,
 187                 });
 188
 189             (args.next().unwrap(), args.collect())
 190         };
 191
 192         let data = CompilationOptions {
 193             directory: self.tcx.sess.working_dir.0.clone(),
 194             program,
 195             arguments,
 196             output: self.save_ctxt.compilation_output(crate_name),
 197         };
 198
 199         self.dumper.compilation_opts(data);
 200     }
 201
 202     fn write_segments(&mut self, segments: impl IntoIterator<Item = &'tcx hir::PathSegment<'tcx>>) {
 203         for seg in segments {
 204             if let Some(data) = self.save_ctxt.get_path_segment_data(seg) {
 205                 self.dumper.dump_ref(data);
 206             }
 207         }
 208     }
 209
 210     fn write_sub_paths(&mut self, path: &'tcx hir::Path<'tcx>) {
 211         self.write_segments(path.segments)
 212     }
 213
 214     // As write_sub_paths, but does not process the last ident in the path (assuming it
 215     // will be processed elsewhere). See note on write_sub_paths about global.
 216     fn write_sub_paths_truncated(&mut self, path: &'tcx hir::Path<'tcx>) {
 217         if let [segments @ .., _] = path.segments {
 218             self.write_segments(segments)
 219         }
 220     }
 221
 222     fn process_formals(&mut self, formals: &'tcx [hir::Param<'tcx>], qualname: &str) {
 223         for arg in formals {
 224             self.visit_pat(&arg.pat);
 225             let mut collector = PathCollector::new(self.tcx);
 226             collector.visit_pat(&arg.pat);
 227
 228             for (hir_id, ident, ..) in collector.collected_idents {
 229                 let typ = match self.save_ctxt.typeck_results().node_type_opt(hir_id) {
 230                     Some(s) => s.to_string(),
 231                     None => continue,
 232                 };
 233                 if !self.span.filter_generated(ident.span) {
 234                     let id = id_from_hir_id(hir_id, &self.save_ctxt);
 235                     let span = self.span_from_span(ident.span);
 236
 237                     self.dumper.dump_def(
 238                         &Access { public: false, reachable: false },
 239                         Def {
 240                             kind: DefKind::Local,
 241                             id,
 242                             span,
 243                             name: ident.to_string(),
 244                             qualname: format!("{}::{}", qualname, ident.to_string()),
 245                             value: typ,
 246                             parent: None,
 247                             children: vec![],
 248                             decl_id: None,
 249                             docs: String::new(),
 250                             sig: None,
 251                             attributes: vec![],
 252                         },
 253                     );
 254                 }
 255             }
 256         }
 257     }
 258
 259     fn process_method(
 260         &mut self,
 261         sig: &'tcx hir::FnSig<'tcx>,
 262         body: Option<hir::BodyId>,
 263         hir_id: hir::HirId,
 264         ident: Ident,
 265         generics: &'tcx hir::Generics<'tcx>,
 266         vis: &hir::Visibility<'tcx>,
 267         span: Span,
 268     ) {
 269         debug!("process_method: {}:{}", hir_id, ident);
 270
 271         let map = &self.tcx.hir();
 272         self.nest_typeck_results(map.local_def_id(hir_id), |v| {
 273             if let Some(mut method_data) = v.save_ctxt.get_method_data(hir_id, ident, span) {
 274                 if let Some(body) = body {
 275                     v.process_formals(map.body(body).params, &method_data.qualname);
 276                 }
 277                 v.process_generic_params(&generics, &method_data.qualname, hir_id);
 278
 279                 method_data.value =
 280                     fn_to_string(sig.decl, sig.header, Some(ident.name), generics, vis, &[], None);
 281                 method_data.sig = sig::method_signature(hir_id, ident, generics, sig, &v.save_ctxt);
 282
 283                 v.dumper.dump_def(&access_from_vis!(v.save_ctxt, vis, hir_id), method_data);
 284             }
 285
 286             // walk arg and return types
 287             for arg in sig.decl.inputs {
 288                 v.visit_ty(arg);
 289             }
 290
 291             if let hir::FnRetTy::Return(ref ret_ty) = sig.decl.output {
 292                 v.visit_ty(ret_ty)
 293             }
 294
 295             // walk the fn body
 296             if let Some(body) = body {
 297                 v.visit_expr(&map.body(body).value);
 298             }
 299         });
 300     }
 301
 302     fn process_struct_field_def(
 303         &mut self,
 304         field: &'tcx hir::FieldDef<'tcx>,
 305         parent_id: hir::HirId,
 306     ) {
 307         let field_data = self.save_ctxt.get_field_data(field, parent_id);
 308         if let Some(field_data) = field_data {
 309             self.dumper.dump_def(&access_from!(self.save_ctxt, field, field.hir_id), field_data);
 310         }
 311     }
 312
 313     // Dump generic params bindings, then visit_generics
 314     fn process_generic_params(
 315         &mut self,
 316         generics: &'tcx hir::Generics<'tcx>,
 317         prefix: &str,
 318         id: hir::HirId,
 319     ) {
 320         for param in generics.params {
 321             match param.kind {
 322                 hir::GenericParamKind::Lifetime { .. } => {}
 323                 hir::GenericParamKind::Type { .. } => {
 324                     let param_ss = param.name.ident().span;
 325                     let name = escape(self.span.snippet(param_ss));
 326                     // Append $id to name to make sure each one is unique.
 327                     let qualname = format!("{}::{}${}", prefix, name, id);
 328                     if !self.span.filter_generated(param_ss) {
 329                         let id = id_from_hir_id(param.hir_id, &self.save_ctxt);
 330                         let span = self.span_from_span(param_ss);
 331
 332                         self.dumper.dump_def(
 333                             &Access { public: false, reachable: false },
 334                             Def {
 335                                 kind: DefKind::Type,
 336                                 id,
 337                                 span,
 338                                 name,
 339                                 qualname,
 340                                 value: String::new(),
 341                                 parent: None,
 342                                 children: vec![],
 343                                 decl_id: None,
 344                                 docs: String::new(),
 345                                 sig: None,
 346                                 attributes: vec![],
 347                             },
 348                         );
 349                     }
 350                 }
 351                 hir::GenericParamKind::Const { .. } => {}
 352             }
 353         }
 354
 355         self.visit_generics(generics)
 356     }
 357
 358     fn process_fn(
 359         &mut self,
 360         item: &'tcx hir::Item<'tcx>,
 361         decl: &'tcx hir::FnDecl<'tcx>,
 362         _header: &'tcx hir::FnHeader,
 363         ty_params: &'tcx hir::Generics<'tcx>,
 364         body: hir::BodyId,
 365     ) {
 366         let map = &self.tcx.hir();
 367         self.nest_typeck_results(item.def_id, |v| {
 368             let body = map.body(body);
 369             if let Some(fn_data) = v.save_ctxt.get_item_data(item) {
 370                 down_cast_data!(fn_data, DefData, item.span);
 371                 v.process_formals(body.params, &fn_data.qualname);
 372                 v.process_generic_params(ty_params, &fn_data.qualname, item.hir_id());
 373
 374                 v.dumper.dump_def(&access_from!(v.save_ctxt, item, item.hir_id()), fn_data);
 375             }
 376
 377             for arg in decl.inputs {
 378                 v.visit_ty(arg)
 379             }
 380
 381             if let hir::FnRetTy::Return(ref ret_ty) = decl.output {
 382                 v.visit_ty(ret_ty)
 383             }
 384
 385             v.visit_expr(&body.value);
 386         });
 387     }
 388
 389     fn process_static_or_const_item(
 390         &mut self,
 391         item: &'tcx hir::Item<'tcx>,
 392         typ: &'tcx hir::Ty<'tcx>,
 393         expr: &'tcx hir::Expr<'tcx>,
 394     ) {
 395         self.nest_typeck_results(item.def_id, |v| {
 396             if let Some(var_data) = v.save_ctxt.get_item_data(item) {
 397                 down_cast_data!(var_data, DefData, item.span);
 398                 v.dumper.dump_def(&access_from!(v.save_ctxt, item, item.hir_id()), var_data);
 399             }
 400             v.visit_ty(&typ);
 401             v.visit_expr(expr);
 402         });
 403     }
 404
 405     fn process_assoc_const(
 406         &mut self,
 407         hir_id: hir::HirId,
 408         ident: Ident,
 409         typ: &'tcx hir::Ty<'tcx>,
 410         expr: Option<&'tcx hir::Expr<'tcx>>,
 411         parent_id: DefId,
 412         vis: &hir::Visibility<'tcx>,
 413         attrs: &'tcx [ast::Attribute],
 414     ) {
 415         let qualname =
 416             format!("::{}", self.tcx.def_path_str(self.tcx.hir().local_def_id(hir_id).to_def_id()));
 417
 418         if !self.span.filter_generated(ident.span) {
 419             let sig = sig::assoc_const_signature(hir_id, ident.name, typ, expr, &self.save_ctxt);
 420             let span = self.span_from_span(ident.span);
 421
 422             self.dumper.dump_def(
 423                 &access_from_vis!(self.save_ctxt, vis, hir_id),
 424                 Def {
 425                     kind: DefKind::Const,
 426                     id: id_from_hir_id(hir_id, &self.save_ctxt),
 427                     span,
 428                     name: ident.name.to_string(),
 429                     qualname,
 430                     value: ty_to_string(&typ),
 431                     parent: Some(id_from_def_id(parent_id)),
 432                     children: vec![],
 433                     decl_id: None,
 434                     docs: self.save_ctxt.docs_for_attrs(attrs),
 435                     sig,
 436                     attributes: lower_attributes(attrs.to_owned(), &self.save_ctxt),
 437                 },
 438             );
 439         }
 440
 441         // walk type and init value
 442         self.nest_typeck_results(self.tcx.hir().local_def_id(hir_id), |v| {
 443             v.visit_ty(typ);
 444             if let Some(expr) = expr {
 445                 v.visit_expr(expr);
 446             }
 447         });
 448     }
 449
 450     // FIXME tuple structs should generate tuple-specific data.
 451     fn process_struct(
 452         &mut self,
 453         item: &'tcx hir::Item<'tcx>,
 454         def: &'tcx hir::VariantData<'tcx>,
 455         ty_params: &'tcx hir::Generics<'tcx>,
 456     ) {
 457         debug!("process_struct {:?} {:?}", item, item.span);
 458         let name = item.ident.to_string();
 459         let qualname = format!("::{}", self.tcx.def_path_str(item.def_id.to_def_id()));
 460
 461         let kind = match item.kind {
 462             hir::ItemKind::Struct(_, _) => DefKind::Struct,
 463             hir::ItemKind::Union(_, _) => DefKind::Union,
 464             _ => unreachable!(),
 465         };
 466
 467         let (value, fields) = match item.kind {
 468             hir::ItemKind::Struct(hir::VariantData::Struct(ref fields, ..), ..)
 469             | hir::ItemKind::Union(hir::VariantData::Struct(ref fields, ..), ..) => {
 470                 let include_priv_fields = !self.save_ctxt.config.pub_only;
 471                 let fields_str = fields
 472                     .iter()
 473                     .filter_map(|f| {
 474                         if include_priv_fields || f.vis.node.is_pub() {
 475                             Some(f.ident.to_string())
 476                         } else {
 477                             None
 478                         }
 479                     })
 480                     .collect::<Vec<_>>()
 481                     .join(", ");
 482                 let value = format!("{} {{ {} }}", name, fields_str);
 483                 (value, fields.iter().map(|f| id_from_hir_id(f.hir_id, &self.save_ctxt)).collect())
 484             }
 485             _ => (String::new(), vec![]),
 486         };
 487
 488         if !self.span.filter_generated(item.ident.span) {
 489             let span = self.span_from_span(item.ident.span);
 490             let attrs = self.tcx.hir().attrs(item.hir_id());
 491             self.dumper.dump_def(
 492                 &access_from!(self.save_ctxt, item, item.hir_id()),
 493                 Def {
 494                     kind,
 495                     id: id_from_def_id(item.def_id.to_def_id()),
 496                     span,
 497                     name,
 498                     qualname: qualname.clone(),
 499                     value,
 500                     parent: None,
 501                     children: fields,
 502                     decl_id: None,
 503                     docs: self.save_ctxt.docs_for_attrs(attrs),
 504                     sig: sig::item_signature(item, &self.save_ctxt),
 505                     attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 506                 },
 507             );
 508         }
 509
 510         self.nest_typeck_results(item.def_id, |v| {
 511             for field in def.fields() {
 512                 v.process_struct_field_def(field, item.hir_id());
 513                 v.visit_ty(&field.ty);
 514             }
 515
 516             v.process_generic_params(ty_params, &qualname, item.hir_id());
 517         });
 518     }
 519
 520     fn process_enum(
 521         &mut self,
 522         item: &'tcx hir::Item<'tcx>,
 523         enum_definition: &'tcx hir::EnumDef<'tcx>,
 524         ty_params: &'tcx hir::Generics<'tcx>,
 525     ) {
 526         let enum_data = self.save_ctxt.get_item_data(item);
 527         let enum_data = match enum_data {
 528             None => return,
 529             Some(data) => data,
 530         };
 531         down_cast_data!(enum_data, DefData, item.span);
 532
 533         let access = access_from!(self.save_ctxt, item, item.hir_id());
 534
 535         for variant in enum_definition.variants {
 536             let name = variant.ident.name.to_string();
 537             let qualname = format!("{}::{}", enum_data.qualname, name);
 538             let name_span = variant.ident.span;
 539
 540             match variant.data {
 541                 hir::VariantData::Struct(ref fields, ..) => {
 542                     let fields_str =
 543                         fields.iter().map(|f| f.ident.to_string()).collect::<Vec<_>>().join(", ");
 544                     let value = format!("{}::{} {{ {} }}", enum_data.name, name, fields_str);
 545                     if !self.span.filter_generated(name_span) {
 546                         let span = self.span_from_span(name_span);
 547                         let id = id_from_hir_id(variant.id, &self.save_ctxt);
 548                         let parent = Some(id_from_def_id(item.def_id.to_def_id()));
 549                         let attrs = self.tcx.hir().attrs(variant.id);
 550
 551                         self.dumper.dump_def(
 552                             &access,
 553                             Def {
 554                                 kind: DefKind::StructVariant,
 555                                 id,
 556                                 span,
 557                                 name,
 558                                 qualname,
 559                                 value,
 560                                 parent,
 561                                 children: vec![],
 562                                 decl_id: None,
 563                                 docs: self.save_ctxt.docs_for_attrs(attrs),
 564                                 sig: sig::variant_signature(variant, &self.save_ctxt),
 565                                 attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 566                             },
 567                         );
 568                     }
 569                 }
 570                 ref v => {
 571                     let mut value = format!("{}::{}", enum_data.name, name);
 572                     if let hir::VariantData::Tuple(fields, _) = v {
 573                         value.push('(');
 574                         value.push_str(
 575                             &fields
 576                                 .iter()
 577                                 .map(|f| ty_to_string(&f.ty))
 578                                 .collect::<Vec<_>>()
 579                                 .join(", "),
 580                         );
 581                         value.push(')');
 582                     }
 583                     if !self.span.filter_generated(name_span) {
 584                         let span = self.span_from_span(name_span);
 585                         let id = id_from_hir_id(variant.id, &self.save_ctxt);
 586                         let parent = Some(id_from_def_id(item.def_id.to_def_id()));
 587                         let attrs = self.tcx.hir().attrs(variant.id);
 588
 589                         self.dumper.dump_def(
 590                             &access,
 591                             Def {
 592                                 kind: DefKind::TupleVariant,
 593                                 id,
 594                                 span,
 595                                 name,
 596                                 qualname,
 597                                 value,
 598                                 parent,
 599                                 children: vec![],
 600                                 decl_id: None,
 601                                 docs: self.save_ctxt.docs_for_attrs(attrs),
 602                                 sig: sig::variant_signature(variant, &self.save_ctxt),
 603                                 attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 604                             },
 605                         );
 606                     }
 607                 }
 608             }
 609
 610             for field in variant.data.fields() {
 611                 self.process_struct_field_def(field, variant.id);
 612                 self.visit_ty(field.ty);
 613             }
 614         }
 615         self.process_generic_params(ty_params, &enum_data.qualname, item.hir_id());
 616         self.dumper.dump_def(&access, enum_data);
 617     }
 618
 619     fn process_impl(&mut self, item: &'tcx hir::Item<'tcx>, impl_: &'tcx hir::Impl<'tcx>) {
 620         if let Some(impl_data) = self.save_ctxt.get_item_data(item) {
 621             if !self.span.filter_generated(item.span) {
 622                 if let super::Data::RelationData(rel, imp) = impl_data {
 623                     self.dumper.dump_relation(rel);
 624                     self.dumper.dump_impl(imp);
 625                 } else {
 626                     span_bug!(item.span, "unexpected data kind: {:?}", impl_data);
 627                 }
 628             }
 629         }
 630
 631         let map = &self.tcx.hir();
 632         self.nest_typeck_results(item.def_id, |v| {
 633             v.visit_ty(&impl_.self_ty);
 634             if let Some(trait_ref) = &impl_.of_trait {
 635                 v.process_path(trait_ref.hir_ref_id, &hir::QPath::Resolved(None, &trait_ref.path));
 636             }
 637             v.process_generic_params(&impl_.generics, "", item.hir_id());
 638             for impl_item in impl_.items {
 639                 v.process_impl_item(map.impl_item(impl_item.id), item.def_id.to_def_id());
 640             }
 641         });
 642     }
 643
 644     fn process_trait(
 645         &mut self,
 646         item: &'tcx hir::Item<'tcx>,
 647         generics: &'tcx hir::Generics<'tcx>,
 648         trait_refs: hir::GenericBounds<'tcx>,
 649         methods: &'tcx [hir::TraitItemRef],
 650     ) {
 651         let name = item.ident.to_string();
 652         let qualname = format!("::{}", self.tcx.def_path_str(item.def_id.to_def_id()));
 653         let mut val = name.clone();
 654         if !generics.params.is_empty() {
 655             val.push_str(&generic_params_to_string(generics.params));
 656         }
 657         if !trait_refs.is_empty() {
 658             val.push_str(": ");
 659             val.push_str(&bounds_to_string(trait_refs));
 660         }
 661         if !self.span.filter_generated(item.ident.span) {
 662             let id = id_from_def_id(item.def_id.to_def_id());
 663             let span = self.span_from_span(item.ident.span);
 664             let children =
 665                 methods.iter().map(|i| id_from_def_id(i.id.def_id.to_def_id())).collect();
 666             let attrs = self.tcx.hir().attrs(item.hir_id());
 667             self.dumper.dump_def(
 668                 &access_from!(self.save_ctxt, item, item.hir_id()),
 669                 Def {
 670                     kind: DefKind::Trait,
 671                     id,
 672                     span,
 673                     name,
 674                     qualname: qualname.clone(),
 675                     value: val,
 676                     parent: None,
 677                     children,
 678                     decl_id: None,
 679                     docs: self.save_ctxt.docs_for_attrs(attrs),
 680                     sig: sig::item_signature(item, &self.save_ctxt),
 681                     attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 682                 },
 683             );
 684         }
 685
 686         // super-traits
 687         for super_bound in trait_refs.iter() {
 688             let (def_id, sub_span) = match *super_bound {
 689                 hir::GenericBound::Trait(ref trait_ref, _) => (
 690                     self.lookup_def_id(trait_ref.trait_ref.hir_ref_id),
 691                     trait_ref.trait_ref.path.segments.last().unwrap().ident.span,
 692                 ),
 693                 hir::GenericBound::LangItemTrait(lang_item, span, _, _) => {
 694                     (Some(self.tcx.require_lang_item(lang_item, Some(span))), span)
 695                 }
 696                 hir::GenericBound::Outlives(..) => continue,
 697             };
 698
 699             if let Some(id) = def_id {
 700                 if !self.span.filter_generated(sub_span) {
 701                     let span = self.span_from_span(sub_span);
 702                     self.dumper.dump_ref(Ref {
 703                         kind: RefKind::Type,
 704                         span: span.clone(),
 705                         ref_id: id_from_def_id(id),
 706                     });
 707
 708                     self.dumper.dump_relation(Relation {
 709                         kind: RelationKind::SuperTrait,
 710                         span,
 711                         from: id_from_def_id(id),
 712                         to: id_from_def_id(item.def_id.to_def_id()),
 713                     });
 714                 }
 715             }
 716         }
 717
 718         // walk generics and methods
 719         self.process_generic_params(generics, &qualname, item.hir_id());
 720         for method in methods {
 721             let map = &self.tcx.hir();
 722             self.process_trait_item(map.trait_item(method.id), item.def_id.to_def_id())
 723         }
 724     }
 725
 726     // `item` is the module in question, represented as an( item.
 727     fn process_mod(&mut self, item: &'tcx hir::Item<'tcx>) {
 728         if let Some(mod_data) = self.save_ctxt.get_item_data(item) {
 729             down_cast_data!(mod_data, DefData, item.span);
 730             self.dumper.dump_def(&access_from!(self.save_ctxt, item, item.hir_id()), mod_data);
 731         }
 732     }
 733
 734     fn dump_path_ref(&mut self, id: hir::HirId, path: &hir::QPath<'tcx>) {
 735         let path_data = self.save_ctxt.get_path_data(id, path);
 736         if let Some(path_data) = path_data {
 737             self.dumper.dump_ref(path_data);
 738         }
 739     }
 740
 741     fn dump_path_segment_ref(&mut self, id: hir::HirId, segment: &hir::PathSegment<'tcx>) {
 742         let segment_data = self.save_ctxt.get_path_segment_data_with_id(segment, id);
 743         if let Some(segment_data) = segment_data {
 744             self.dumper.dump_ref(segment_data);
 745         }
 746     }
 747
 748     fn process_path(&mut self, id: hir::HirId, path: &hir::QPath<'tcx>) {
 749         if self.span.filter_generated(path.span()) {
 750             return;
 751         }
 752         self.dump_path_ref(id, path);
 753
 754         // Type arguments
 755         let segments = match path {
 756             hir::QPath::Resolved(ty, path) => {
 757                 if let Some(ty) = ty {
 758                     self.visit_ty(ty);
 759                 }
 760                 path.segments
 761             }
 762             hir::QPath::TypeRelative(ty, segment) => {
 763                 self.visit_ty(ty);
 764                 std::slice::from_ref(*segment)
 765             }
 766             hir::QPath::LangItem(..) => return,
 767         };
 768         for seg in segments {
 769             if let Some(ref generic_args) = seg.args {
 770                 for arg in generic_args.args {
 771                     if let hir::GenericArg::Type(ref ty) = arg {
 772                         self.visit_ty(ty);
 773                     }
 774                 }
 775             }
 776         }
 777
 778         if let hir::QPath::Resolved(_, path) = path {
 779             self.write_sub_paths_truncated(path);
 780         }
 781     }
 782
 783     fn process_struct_lit(
 784         &mut self,
 785         ex: &'tcx hir::Expr<'tcx>,
 786         path: &'tcx hir::QPath<'tcx>,
 787         fields: &'tcx [hir::ExprField<'tcx>],
 788         variant: &'tcx ty::VariantDef,
 789         rest: Option<&'tcx hir::Expr<'tcx>>,
 790     ) {
 791         if let Some(struct_lit_data) = self.save_ctxt.get_expr_data(ex) {
 792             if let hir::QPath::Resolved(_, path) = path {
 793                 self.write_sub_paths_truncated(path);
 794             }
 795             down_cast_data!(struct_lit_data, RefData, ex.span);
 796             if !generated_code(ex.span) {
 797                 self.dumper.dump_ref(struct_lit_data);
 798             }
 799
 800             for field in fields {
 801                 if let Some(field_data) = self.save_ctxt.get_field_ref_data(field, variant) {
 802                     self.dumper.dump_ref(field_data);
 803                 }
 804
 805                 self.visit_expr(&field.expr)
 806             }
 807         }
 808
 809         if let Some(base) = rest {
 810             self.visit_expr(&base);
 811         }
 812     }
 813
 814     fn process_method_call(
 815         &mut self,
 816         ex: &'tcx hir::Expr<'tcx>,
 817         seg: &'tcx hir::PathSegment<'tcx>,
 818         args: &'tcx [hir::Expr<'tcx>],
 819     ) {
 820         debug!("process_method_call {:?} {:?}", ex, ex.span);
 821         if let Some(mcd) = self.save_ctxt.get_expr_data(ex) {
 822             down_cast_data!(mcd, RefData, ex.span);
 823             if !generated_code(ex.span) {
 824                 self.dumper.dump_ref(mcd);
 825             }
 826         }
 827
 828         // Explicit types in the turbo-fish.
 829         if let Some(generic_args) = seg.args {
 830             for arg in generic_args.args {
 831                 if let hir::GenericArg::Type(ty) = arg {
 832                     self.visit_ty(&ty)
 833                 };
 834             }
 835         }
 836
 837         // walk receiver and args
 838         walk_list!(self, visit_expr, args);
 839     }
 840
 841     fn process_pat(&mut self, p: &'tcx hir::Pat<'tcx>) {
 842         match p.kind {
 843             hir::PatKind::Struct(ref _path, fields, _) => {
 844                 // FIXME do something with _path?
 845                 let adt = match self.save_ctxt.typeck_results().node_type_opt(p.hir_id) {
 846                     Some(ty) if ty.ty_adt_def().is_some() => ty.ty_adt_def().unwrap(),
 847                     _ => {
 848                         intravisit::walk_pat(self, p);
 849                         return;
 850                     }
 851                 };
 852                 let variant = adt.variant_of_res(self.save_ctxt.get_path_res(p.hir_id));
 853
 854                 for field in fields {
 855                     if let Some(index) = self.tcx.find_field_index(field.ident, variant) {
 856                         if !self.span.filter_generated(field.ident.span) {
 857                             let span = self.span_from_span(field.ident.span);
 858                             self.dumper.dump_ref(Ref {
 859                                 kind: RefKind::Variable,
 860                                 span,
 861                                 ref_id: id_from_def_id(variant.fields[index].did),
 862                             });
 863                         }
 864                     }
 865                     self.visit_pat(&field.pat);
 866                 }
 867             }
 868             _ => intravisit::walk_pat(self, p),
 869         }
 870     }
 871
 872     fn process_var_decl(&mut self, pat: &'tcx hir::Pat<'tcx>) {
 873         // The pattern could declare multiple new vars,
 874         // we must walk the pattern and collect them all.
 875         let mut collector = PathCollector::new(self.tcx);
 876         collector.visit_pat(&pat);
 877         self.visit_pat(&pat);
 878
 879         // Process collected paths.
 880         for (id, ident, _) in collector.collected_idents {
 881             let res = self.save_ctxt.get_path_res(id);
 882             match res {
 883                 Res::Local(hir_id) => {
 884                     let typ = self
 885                         .save_ctxt
 886                         .typeck_results()
 887                         .node_type_opt(hir_id)
 888                         .map(|t| t.to_string())
 889                         .unwrap_or_default();
 890
 891                     // Rust uses the id of the pattern for var lookups, so we'll use it too.
 892                     if !self.span.filter_generated(ident.span) {
 893                         let qualname = format!("{}${}", ident.to_string(), hir_id);
 894                         let id = id_from_hir_id(hir_id, &self.save_ctxt);
 895                         let span = self.span_from_span(ident.span);
 896
 897                         self.dumper.dump_def(
 898                             &Access { public: false, reachable: false },
 899                             Def {
 900                                 kind: DefKind::Local,
 901                                 id,
 902                                 span,
 903                                 name: ident.to_string(),
 904                                 qualname,
 905                                 value: typ,
 906                                 parent: None,
 907                                 children: vec![],
 908                                 decl_id: None,
 909                                 docs: String::new(),
 910                                 sig: None,
 911                                 attributes: vec![],
 912                             },
 913                         );
 914                     }
 915                 }
 916                 Res::Def(
 917                     HirDefKind::Ctor(..)
 918                     | HirDefKind::Const
 919                     | HirDefKind::AssocConst
 920                     | HirDefKind::Struct
 921                     | HirDefKind::Variant
 922                     | HirDefKind::TyAlias
 923                     | HirDefKind::AssocTy,
 924                     _,
 925                 )
 926                 | Res::SelfTy(..) => {
 927                     self.dump_path_segment_ref(id, &hir::PathSegment::from_ident(ident));
 928                 }
 929                 def => {
 930                     error!("unexpected definition kind when processing collected idents: {:?}", def)
 931                 }
 932             }
 933         }
 934
 935         for (id, ref path) in collector.collected_paths {
 936             self.process_path(id, path);
 937         }
 938     }
 939
 940     /// Extracts macro use and definition information from the AST node defined
 941     /// by the given NodeId, using the expansion information from the node's
 942     /// span.
 943     ///
 944     /// If the span is not macro-generated, do nothing, else use callee and
 945     /// callsite spans to record macro definition and use data, using the
 946     /// mac_uses and mac_defs sets to prevent multiples.
 947     fn process_macro_use(&mut self, _span: Span) {
 948         // FIXME if we're not dumping the defs (see below), there is no point
 949         // dumping refs either.
 950         // let source_span = span.source_callsite();
 951         // if !self.macro_calls.insert(source_span) {
 952         //     return;
 953         // }
 954
 955         // let data = match self.save_ctxt.get_macro_use_data(span) {
 956         //     None => return,
 957         //     Some(data) => data,
 958         // };
 959
 960         // self.dumper.macro_use(data);
 961
 962         // FIXME write the macro def
 963         // let mut hasher = DefaultHasher::new();
 964         // data.callee_span.hash(&mut hasher);
 965         // let hash = hasher.finish();
 966         // let qualname = format!("{}::{}", data.name, hash);
 967         // Don't write macro definition for imported macros
 968         // if !self.mac_defs.contains(&data.callee_span)
 969         //     && !data.imported {
 970         //     self.mac_defs.insert(data.callee_span);
 971         //     if let Some(sub_span) = self.span.span_for_macro_def_name(data.callee_span) {
 972         //         self.dumper.macro_data(MacroData {
 973         //             span: sub_span,
 974         //             name: data.name.clone(),
 975         //             qualname: qualname.clone(),
 976         //             // FIXME where do macro docs come from?
 977         //             docs: String::new(),
 978         //         }.lower(self.tcx));
 979         //     }
 980         // }
 981     }
 982
 983     fn process_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>, trait_id: DefId) {
 984         self.process_macro_use(trait_item.span);
 985         let vis_span = trait_item.span.shrink_to_lo();
 986         match trait_item.kind {
 987             hir::TraitItemKind::Const(ref ty, body) => {
 988                 let body = body.map(|b| &self.tcx.hir().body(b).value);
 989                 let respan = respan(vis_span, hir::VisibilityKind::Public);
 990                 let attrs = self.tcx.hir().attrs(trait_item.hir_id());
 991                 self.process_assoc_const(
 992                     trait_item.hir_id(),
 993                     trait_item.ident,
 994                     &ty,
 995                     body,
 996                     trait_id,
 997                     &respan,
 998                     attrs,
 999                 );
1000             }
1001             hir::TraitItemKind::Fn(ref sig, ref trait_fn) => {
1002                 let body =
1003                     if let hir::TraitFn::Provided(body) = trait_fn { Some(*body) } else { None };
1004                 let respan = respan(vis_span, hir::VisibilityKind::Public);
1005                 self.process_method(
1006                     sig,
1007                     body,
1008                     trait_item.hir_id(),
1009                     trait_item.ident,
1010                     &trait_item.generics,
1011                     &respan,
1012                     trait_item.span,
1013                 );
1014             }
1015             hir::TraitItemKind::Type(ref bounds, ref default_ty) => {
1016                 // FIXME do something with _bounds (for type refs)
1017                 let name = trait_item.ident.name.to_string();
1018                 let qualname =
1019                     format!("::{}", self.tcx.def_path_str(trait_item.def_id.to_def_id()));
1020
1021                 if !self.span.filter_generated(trait_item.ident.span) {
1022                     let span = self.span_from_span(trait_item.ident.span);
1023                     let id = id_from_def_id(trait_item.def_id.to_def_id());
1024                     let attrs = self.tcx.hir().attrs(trait_item.hir_id());
1025
1026                     self.dumper.dump_def(
1027                         &Access { public: true, reachable: true },
1028                         Def {
1029                             kind: DefKind::Type,
1030                             id,
1031                             span,
1032                             name,
1033                             qualname,
1034                             value: self.span.snippet(trait_item.span),
1035                             parent: Some(id_from_def_id(trait_id)),
1036                             children: vec![],
1037                             decl_id: None,
1038                             docs: self.save_ctxt.docs_for_attrs(attrs),
1039                             sig: sig::assoc_type_signature(
1040                                 trait_item.hir_id(),
1041                                 trait_item.ident,
1042                                 Some(bounds),
1043                                 default_ty.as_ref().map(|ty| &**ty),
1044                                 &self.save_ctxt,
1045                             ),
1046                             attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
1047                         },
1048                     );
1049                 }
1050
1051                 if let Some(default_ty) = default_ty {
1052                     self.visit_ty(default_ty)
1053                 }
1054             }
1055         }
1056     }
1057
1058     fn process_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>, impl_id: DefId) {
1059         self.process_macro_use(impl_item.span);
1060         match impl_item.kind {
1061             hir::ImplItemKind::Const(ref ty, body) => {
1062                 let body = self.tcx.hir().body(body);
1063                 let attrs = self.tcx.hir().attrs(impl_item.hir_id());
1064                 self.process_assoc_const(
1065                     impl_item.hir_id(),
1066                     impl_item.ident,
1067                     &ty,
1068                     Some(&body.value),
1069                     impl_id,
1070                     &impl_item.vis,
1071                     attrs,
1072                 );
1073             }
1074             hir::ImplItemKind::Fn(ref sig, body) => {
1075                 self.process_method(
1076                     sig,
1077                     Some(body),
1078                     impl_item.hir_id(),
1079                     impl_item.ident,
1080                     &impl_item.generics,
1081                     &impl_item.vis,
1082                     impl_item.span,
1083                 );
1084             }
1085             hir::ImplItemKind::TyAlias(ref ty) => {
1086                 // FIXME: uses of the assoc type should ideally point to this
1087                 // 'def' and the name here should be a ref to the def in the
1088                 // trait.
1089                 self.visit_ty(ty)
1090             }
1091         }
1092     }
1093
1094     pub(crate) fn process_crate(&mut self, krate: &'tcx hir::Crate<'tcx>) {
1095         let id = hir::CRATE_HIR_ID;
1096         let qualname =
1097             format!("::{}", self.tcx.def_path_str(self.tcx.hir().local_def_id(id).to_def_id()));
1098
1099         let sm = self.tcx.sess.source_map();
1100         let filename = sm.span_to_filename(krate.item.inner);
1101         let data_id = id_from_hir_id(id, &self.save_ctxt);
1102         let children =
1103             krate.item.item_ids.iter().map(|i| id_from_def_id(i.def_id.to_def_id())).collect();
1104         let span = self.span_from_span(krate.item.inner);
1105         let attrs = self.tcx.hir().attrs(id);
1106
1107         self.dumper.dump_def(
1108             &Access { public: true, reachable: true },
1109             Def {
1110                 kind: DefKind::Mod,
1111                 id: data_id,
1112                 name: String::new(),
1113                 qualname,
1114                 span,
1115                 value: filename.to_string(),
1116                 children,
1117                 parent: None,
1118                 decl_id: None,
1119                 docs: self.save_ctxt.docs_for_attrs(attrs),
1120                 sig: None,
1121                 attributes: lower_attributes(attrs.to_owned(), &self.save_ctxt),
1122             },
1123         );
1124         intravisit::walk_crate(self, krate);
1125     }
1126
1127     fn process_bounds(&mut self, bounds: hir::GenericBounds<'tcx>) {
1128         for bound in bounds {
1129             if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1130                 self.process_path(
1131                     trait_ref.trait_ref.hir_ref_id,
1132                     &hir::QPath::Resolved(None, &trait_ref.trait_ref.path),
1133                 )
1134             }
1135         }
1136     }
1137 }
1138
1139 impl<'tcx> Visitor<'tcx> for DumpVisitor<'tcx> {
1140     type Map = Map<'tcx>;
1141
1142     fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
1143         intravisit::NestedVisitorMap::All(self.tcx.hir())
1144     }
1145
1146     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1147         self.process_macro_use(item.span);
1148         match item.kind {
1149             hir::ItemKind::Use(path, hir::UseKind::Single) => {
1150                 let sub_span = path.segments.last().unwrap().ident.span;
1151                 if !self.span.filter_generated(sub_span) {
1152                     let access = access_from!(self.save_ctxt, item, item.hir_id());
1153                     let ref_id = self.lookup_def_id(item.hir_id()).map(id_from_def_id);
1154                     let span = self.span_from_span(sub_span);
1155                     let parent =
1156                         self.save_ctxt.tcx.parent(item.def_id.to_def_id()).map(id_from_def_id);
1157                     self.dumper.import(
1158                         &access,
1159                         Import {
1160                             kind: ImportKind::Use,
1161                             ref_id,
1162                             span,
1163                             alias_span: None,
1164                             name: item.ident.to_string(),
1165                             value: String::new(),
1166                             parent,
1167                         },
1168                     );
1169                     self.write_sub_paths_truncated(&path);
1170                 }
1171             }
1172             hir::ItemKind::Use(path, hir::UseKind::Glob) => {
1173                 // Make a comma-separated list of names of imported modules.
1174                 let names = self.tcx.names_imported_by_glob_use(item.def_id);
1175                 let names: Vec<_> = names.iter().map(|n| n.to_string()).collect();
1176
1177                 // Otherwise it's a span with wrong macro expansion info, which
1178                 // we don't want to track anyway, since it's probably macro-internal `use`
1179                 if let Some(sub_span) = self.span.sub_span_of_star(item.span) {
1180                     if !self.span.filter_generated(item.span) {
1181                         let access = access_from!(self.save_ctxt, item, item.hir_id());
1182                         let span = self.span_from_span(sub_span);
1183                         let parent =
1184                             self.save_ctxt.tcx.parent(item.def_id.to_def_id()).map(id_from_def_id);
1185                         self.dumper.import(
1186                             &access,
1187                             Import {
1188                                 kind: ImportKind::GlobUse,
1189                                 ref_id: None,
1190                                 span,
1191                                 alias_span: None,
1192                                 name: "*".to_owned(),
1193                                 value: names.join(", "),
1194                                 parent,
1195                             },
1196                         );
1197                         self.write_sub_paths(&path);
1198                     }
1199                 }
1200             }
1201             hir::ItemKind::ExternCrate(_) => {
1202                 let name_span = item.ident.span;
1203                 if !self.span.filter_generated(name_span) {
1204                     let span = self.span_from_span(name_span);
1205                     let parent =
1206                         self.save_ctxt.tcx.parent(item.def_id.to_def_id()).map(id_from_def_id);
1207                     self.dumper.import(
1208                         &Access { public: false, reachable: false },
1209                         Import {
1210                             kind: ImportKind::ExternCrate,
1211                             ref_id: None,
1212                             span,
1213                             alias_span: None,
1214                             name: item.ident.to_string(),
1215                             value: String::new(),
1216                             parent,
1217                         },
1218                     );
1219                 }
1220             }
1221             hir::ItemKind::Fn(ref sig, ref ty_params, body) => {
1222                 self.process_fn(item, sig.decl, &sig.header, ty_params, body)
1223             }
1224             hir::ItemKind::Static(ref typ, _, body) => {
1225                 let body = self.tcx.hir().body(body);
1226                 self.process_static_or_const_item(item, typ, &body.value)
1227             }
1228             hir::ItemKind::Const(ref typ, body) => {
1229                 let body = self.tcx.hir().body(body);
1230                 self.process_static_or_const_item(item, typ, &body.value)
1231             }
1232             hir::ItemKind::Struct(ref def, ref ty_params)
1233             | hir::ItemKind::Union(ref def, ref ty_params) => {
1234                 self.process_struct(item, def, ty_params)
1235             }
1236             hir::ItemKind::Enum(ref def, ref ty_params) => self.process_enum(item, def, ty_params),
1237             hir::ItemKind::Impl(ref impl_) => self.process_impl(item, impl_),
1238             hir::ItemKind::Trait(_, _, ref generics, ref trait_refs, methods) => {
1239                 self.process_trait(item, generics, trait_refs, methods)
1240             }
1241             hir::ItemKind::Mod(ref m) => {
1242                 self.process_mod(item);
1243                 intravisit::walk_mod(self, m, item.hir_id());
1244             }
1245             hir::ItemKind::TyAlias(ty, ref generics) => {
1246                 let qualname = format!("::{}", self.tcx.def_path_str(item.def_id.to_def_id()));
1247                 let value = ty_to_string(&ty);
1248                 if !self.span.filter_generated(item.ident.span) {
1249                     let span = self.span_from_span(item.ident.span);
1250                     let id = id_from_def_id(item.def_id.to_def_id());
1251                     let attrs = self.tcx.hir().attrs(item.hir_id());
1252
1253                     self.dumper.dump_def(
1254                         &access_from!(self.save_ctxt, item, item.hir_id()),
1255                         Def {
1256                             kind: DefKind::Type,
1257                             id,
1258                             span,
1259                             name: item.ident.to_string(),
1260                             qualname: qualname.clone(),
1261                             value,
1262                             parent: None,
1263                             children: vec![],
1264                             decl_id: None,
1265                             docs: self.save_ctxt.docs_for_attrs(attrs),
1266                             sig: sig::item_signature(item, &self.save_ctxt),
1267                             attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
1268                         },
1269                     );
1270                 }
1271
1272                 self.visit_ty(ty);
1273                 self.process_generic_params(generics, &qualname, item.hir_id());
1274             }
1275             _ => intravisit::walk_item(self, item),
1276         }
1277     }
1278
1279     fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1280         for param in generics.params {
1281             match param.kind {
1282                 hir::GenericParamKind::Lifetime { .. } => {}
1283                 hir::GenericParamKind::Type { ref default, .. } => {
1284                     self.process_bounds(param.bounds);
1285                     if let Some(ref ty) = default {
1286                         self.visit_ty(ty);
1287                     }
1288                 }
1289                 hir::GenericParamKind::Const { ref ty, ref default } => {
1290                     self.process_bounds(param.bounds);
1291                     self.visit_ty(ty);
1292                     if let Some(default) = default {
1293                         self.visit_anon_const(default);
1294                     }
1295                 }
1296             }
1297         }
1298         for pred in generics.where_clause.predicates {
1299             if let hir::WherePredicate::BoundPredicate(ref wbp) = *pred {
1300                 self.process_bounds(wbp.bounds);
1301                 self.visit_ty(wbp.bounded_ty);
1302             }
1303         }
1304     }
1305
1306     fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1307         self.process_macro_use(t.span);
1308         match t.kind {
1309             hir::TyKind::Path(ref path) => {
1310                 if generated_code(t.span) {
1311                     return;
1312                 }
1313
1314                 if let Some(id) = self.lookup_def_id(t.hir_id) {
1315                     let sub_span = path.last_segment_span();
1316                     let span = self.span_from_span(sub_span);
1317                     self.dumper.dump_ref(Ref {
1318                         kind: RefKind::Type,
1319                         span,
1320                         ref_id: id_from_def_id(id),
1321                     });
1322                 }
1323
1324                 if let hir::QPath::Resolved(_, path) = path {
1325                     self.write_sub_paths_truncated(path);
1326                 }
1327                 intravisit::walk_qpath(self, path, t.hir_id, t.span);
1328             }
1329             hir::TyKind::Array(ref ty, ref anon_const) => {
1330                 self.visit_ty(ty);
1331                 let map = self.tcx.hir();
1332                 self.nest_typeck_results(self.tcx.hir().local_def_id(anon_const.hir_id), |v| {
1333                     v.visit_expr(&map.body(anon_const.body).value)
1334                 });
1335             }
1336             hir::TyKind::OpaqueDef(item_id, _) => {
1337                 let item = self.tcx.hir().item(item_id);
1338                 self.nest_typeck_results(item_id.def_id, |v| v.visit_item(item));
1339             }
1340             _ => intravisit::walk_ty(self, t),
1341         }
1342     }
1343
1344     fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
1345         debug!("visit_expr {:?}", ex.kind);
1346         self.process_macro_use(ex.span);
1347         match ex.kind {
1348             hir::ExprKind::Struct(ref path, ref fields, ref rest) => {
1349                 let hir_expr = self.save_ctxt.tcx.hir().expect_expr(ex.hir_id);
1350                 let adt = match self.save_ctxt.typeck_results().expr_ty_opt(&hir_expr) {
1351                     Some(ty) if ty.ty_adt_def().is_some() => ty.ty_adt_def().unwrap(),
1352                     _ => {
1353                         intravisit::walk_expr(self, ex);
1354                         return;
1355                     }
1356                 };
1357                 let res = self.save_ctxt.get_path_res(hir_expr.hir_id);
1358                 self.process_struct_lit(ex, path, fields, adt.variant_of_res(res), *rest)
1359             }
1360             hir::ExprKind::MethodCall(ref seg, _, args, _) => {
1361                 self.process_method_call(ex, seg, args)
1362             }
1363             hir::ExprKind::Field(ref sub_ex, _) => {
1364                 self.visit_expr(&sub_ex);
1365
1366                 if let Some(field_data) = self.save_ctxt.get_expr_data(ex) {
1367                     down_cast_data!(field_data, RefData, ex.span);
1368                     if !generated_code(ex.span) {
1369                         self.dumper.dump_ref(field_data);
1370                     }
1371                 }
1372             }
1373             hir::ExprKind::Closure(_, ref decl, body, _fn_decl_span, _) => {
1374                 let id = format!("${}", ex.hir_id);
1375
1376                 // walk arg and return types
1377                 for ty in decl.inputs {
1378                     self.visit_ty(ty);
1379                 }
1380
1381                 if let hir::FnRetTy::Return(ref ret_ty) = decl.output {
1382                     self.visit_ty(ret_ty);
1383                 }
1384
1385                 // walk the body
1386                 let map = self.tcx.hir();
1387                 self.nest_typeck_results(self.tcx.hir().local_def_id(ex.hir_id), |v| {
1388                     let body = map.body(body);
1389                     v.process_formals(body.params, &id);
1390                     v.visit_expr(&body.value)
1391                 });
1392             }
1393             hir::ExprKind::Repeat(ref expr, ref anon_const) => {
1394                 self.visit_expr(expr);
1395                 let map = self.tcx.hir();
1396                 self.nest_typeck_results(self.tcx.hir().local_def_id(anon_const.hir_id), |v| {
1397                     v.visit_expr(&map.body(anon_const.body).value)
1398                 });
1399             }
1400             // In particular, we take this branch for call and path expressions,
1401             // where we'll index the idents involved just by continuing to walk.
1402             _ => intravisit::walk_expr(self, ex),
1403         }
1404     }
1405
1406     fn visit_pat(&mut self, p: &'tcx hir::Pat<'tcx>) {
1407         self.process_macro_use(p.span);
1408         self.process_pat(p);
1409     }
1410
1411     fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) {
1412         self.process_var_decl(&arm.pat);
1413         if let Some(hir::Guard::If(expr)) = &arm.guard {
1414             self.visit_expr(expr);
1415         }
1416         self.visit_expr(&arm.body);
1417     }
1418
1419     fn visit_qpath(&mut self, path: &'tcx hir::QPath<'tcx>, id: hir::HirId, _: Span) {
1420         self.process_path(id, path);
1421     }
1422
1423     fn visit_stmt(&mut self, s: &'tcx hir::Stmt<'tcx>) {
1424         self.process_macro_use(s.span);
1425         intravisit::walk_stmt(self, s)
1426     }
1427
1428     fn visit_local(&mut self, l: &'tcx hir::Local<'tcx>) {
1429         self.process_macro_use(l.span);
1430         self.process_var_decl(&l.pat);
1431
1432         // Just walk the initialiser and type (don't want to walk the pattern again).
1433         walk_list!(self, visit_ty, &l.ty);
1434         walk_list!(self, visit_expr, &l.init);
1435     }
1436
1437     fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1438         let access = access_from!(self.save_ctxt, item, item.hir_id());
1439
1440         match item.kind {
1441             hir::ForeignItemKind::Fn(decl, _, ref generics) => {
1442                 if let Some(fn_data) = self.save_ctxt.get_extern_item_data(item) {
1443                     down_cast_data!(fn_data, DefData, item.span);
1444
1445                     self.process_generic_params(generics, &fn_data.qualname, item.hir_id());
1446                     self.dumper.dump_def(&access, fn_data);
1447                 }
1448
1449                 for ty in decl.inputs {
1450                     self.visit_ty(ty);
1451                 }
1452
1453                 if let hir::FnRetTy::Return(ref ret_ty) = decl.output {
1454                     self.visit_ty(ret_ty);
1455                 }
1456             }
1457             hir::ForeignItemKind::Static(ref ty, _) => {
1458                 if let Some(var_data) = self.save_ctxt.get_extern_item_data(item) {
1459                     down_cast_data!(var_data, DefData, item.span);
1460                     self.dumper.dump_def(&access, var_data);
1461                 }
1462
1463                 self.visit_ty(ty);
1464             }
1465             hir::ForeignItemKind::Type => {
1466                 if let Some(var_data) = self.save_ctxt.get_extern_item_data(item) {
1467                     down_cast_data!(var_data, DefData, item.span);
1468                     self.dumper.dump_def(&access, var_data);
1469                 }
1470             }
1471         }
1472     }
1473 }