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, CRATE_DEF_ID};
  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::nested_filter;
  25 use rustc_middle::span_bug;
  26 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
  27 use rustc_session::config::Input;
  28 use rustc_span::symbol::Ident;
  29 use rustc_span::*;
  30
  31 use std::env;
  32 use std::path::Path;
  33
  34 use crate::dumper::{Access, Dumper};
  35 use crate::sig;
  36 use crate::span_utils::SpanUtils;
  37 use crate::{
  38     escape, generated_code, id_from_def_id, id_from_hir_id, lower_attributes, PathCollector,
  39     SaveContext,
  40 };
  41
  42 use rls_data::{
  43     CompilationOptions, CratePreludeData, Def, DefKind, GlobalCrateId, Import, ImportKind, Ref,
  44     RefKind, Relation, RelationKind, SpanData,
  45 };
  46
  47 use tracing::{debug, error};
  48
  49 #[rustfmt::skip] // https://github.com/rust-lang/rustfmt/issues/5213
  50 macro_rules! down_cast_data {
  51     ($id:ident, $kind:ident, $sp:expr) => {
  52         let super::Data::$kind($id) = $id else {
  53             span_bug!($sp, "unexpected data kind: {:?}", $id);
  54         };
  55     };
  56 }
  57
  58 macro_rules! access_from {
  59     ($save_ctxt:expr, $id:expr) => {
  60         Access {
  61             public: $save_ctxt.tcx.visibility($id).is_public(),
  62             reachable: $save_ctxt.access_levels.is_reachable($id),
  63         }
  64     };
  65 }
  66
  67 pub struct DumpVisitor<'tcx> {
  68     pub save_ctxt: SaveContext<'tcx>,
  69     tcx: TyCtxt<'tcx>,
  70     dumper: Dumper,
  71
  72     span: SpanUtils<'tcx>,
  73     // Set of macro definition (callee) spans, and the set
  74     // of macro use (callsite) spans. We store these to ensure
  75     // we only write one macro def per unique macro definition, and
  76     // one macro use per unique callsite span.
  77     // mac_defs: FxHashSet<Span>,
  78     // macro_calls: FxHashSet<Span>,
  79 }
  80
  81 impl<'tcx> DumpVisitor<'tcx> {
  82     pub fn new(save_ctxt: SaveContext<'tcx>) -> DumpVisitor<'tcx> {
  83         let span_utils = SpanUtils::new(&save_ctxt.tcx.sess);
  84         let dumper = Dumper::new(save_ctxt.config.clone());
  85         DumpVisitor {
  86             tcx: save_ctxt.tcx,
  87             save_ctxt,
  88             dumper,
  89             span: span_utils,
  90             // mac_defs: FxHashSet::default(),
  91             // macro_calls: FxHashSet::default(),
  92         }
  93     }
  94
  95     pub fn analysis(&self) -> &rls_data::Analysis {
  96         self.dumper.analysis()
  97     }
  98
  99     fn nest_typeck_results<F>(&mut self, item_def_id: LocalDefId, f: F)
 100     where
 101         F: FnOnce(&mut Self),
 102     {
 103         let typeck_results = if self.tcx.has_typeck_results(item_def_id) {
 104             Some(self.tcx.typeck(item_def_id))
 105         } else {
 106             None
 107         };
 108
 109         let old_maybe_typeck_results = self.save_ctxt.maybe_typeck_results;
 110         self.save_ctxt.maybe_typeck_results = typeck_results;
 111         f(self);
 112         self.save_ctxt.maybe_typeck_results = old_maybe_typeck_results;
 113     }
 114
 115     fn span_from_span(&self, span: Span) -> SpanData {
 116         self.save_ctxt.span_from_span(span)
 117     }
 118
 119     fn lookup_def_id(&self, ref_id: hir::HirId) -> Option<DefId> {
 120         self.save_ctxt.lookup_def_id(ref_id)
 121     }
 122
 123     pub fn dump_crate_info(&mut self, name: &str) {
 124         let source_file = self.tcx.sess.local_crate_source_file.as_ref();
 125         let crate_root = source_file.map(|source_file| {
 126             let source_file = Path::new(source_file);
 127             match source_file.file_name() {
 128                 Some(_) => source_file.parent().unwrap().display(),
 129                 None => source_file.display(),
 130             }
 131             .to_string()
 132         });
 133
 134         let data = CratePreludeData {
 135             crate_id: GlobalCrateId {
 136                 name: name.into(),
 137                 disambiguator: (self.tcx.sess.local_stable_crate_id().to_u64(), 0),
 138             },
 139             crate_root: crate_root.unwrap_or_else(|| "<no source>".to_owned()),
 140             external_crates: self.save_ctxt.get_external_crates(),
 141             span: self.span_from_span(self.tcx.def_span(CRATE_DEF_ID)),
 142         };
 143
 144         self.dumper.crate_prelude(data);
 145     }
 146
 147     pub fn dump_compilation_options(&mut self, input: &Input, crate_name: &str) {
 148         // Apply possible `remap-path-prefix` remapping to the input source file
 149         // (and don't include remapping args anymore)
 150         let (program, arguments) = {
 151             let remap_arg_indices = {
 152                 let mut indices = FxHashSet::default();
 153                 // Args are guaranteed to be valid UTF-8 (checked early)
 154                 for (i, e) in env::args().enumerate() {
 155                     if e.starts_with("--remap-path-prefix=") {
 156                         indices.insert(i);
 157                     } else if e == "--remap-path-prefix" {
 158                         indices.insert(i);
 159                         indices.insert(i + 1);
 160                     }
 161                 }
 162                 indices
 163             };
 164
 165             let mut args = env::args()
 166                 .enumerate()
 167                 .filter(|(i, _)| !remap_arg_indices.contains(i))
 168                 .map(|(_, arg)| match input {
 169                     Input::File(ref path) if path == Path::new(&arg) => {
 170                         let mapped = &self.tcx.sess.local_crate_source_file;
 171                         mapped.as_ref().unwrap().to_string_lossy().into()
 172                     }
 173                     _ => arg,
 174                 });
 175
 176             (args.next().unwrap(), args.collect())
 177         };
 178
 179         let data = CompilationOptions {
 180             directory: self.tcx.sess.opts.working_dir.remapped_path_if_available().into(),
 181             program,
 182             arguments,
 183             output: self.save_ctxt.compilation_output(crate_name),
 184         };
 185
 186         self.dumper.compilation_opts(data);
 187     }
 188
 189     fn write_segments(&mut self, segments: impl IntoIterator<Item = &'tcx hir::PathSegment<'tcx>>) {
 190         for seg in segments {
 191             if let Some(data) = self.save_ctxt.get_path_segment_data(seg) {
 192                 self.dumper.dump_ref(data);
 193             }
 194         }
 195     }
 196
 197     fn write_sub_paths(&mut self, path: &'tcx hir::Path<'tcx>) {
 198         self.write_segments(path.segments)
 199     }
 200
 201     // As write_sub_paths, but does not process the last ident in the path (assuming it
 202     // will be processed elsewhere). See note on write_sub_paths about global.
 203     fn write_sub_paths_truncated(&mut self, path: &'tcx hir::Path<'tcx>) {
 204         if let [segments @ .., _] = path.segments {
 205             self.write_segments(segments)
 206         }
 207     }
 208
 209     fn process_formals(&mut self, formals: &'tcx [hir::Param<'tcx>], qualname: &str) {
 210         for arg in formals {
 211             self.visit_pat(&arg.pat);
 212             let mut collector = PathCollector::new(self.tcx);
 213             collector.visit_pat(&arg.pat);
 214
 215             for (hir_id, ident, ..) in collector.collected_idents {
 216                 let typ = match self.save_ctxt.typeck_results().node_type_opt(hir_id) {
 217                     Some(s) => s.to_string(),
 218                     None => continue,
 219                 };
 220                 if !self.span.filter_generated(ident.span) {
 221                     let id = id_from_hir_id(hir_id, &self.save_ctxt);
 222                     let span = self.span_from_span(ident.span);
 223
 224                     self.dumper.dump_def(
 225                         &Access { public: false, reachable: false },
 226                         Def {
 227                             kind: DefKind::Local,
 228                             id,
 229                             span,
 230                             name: ident.to_string(),
 231                             qualname: format!("{}::{}", qualname, ident),
 232                             value: typ,
 233                             parent: None,
 234                             children: vec![],
 235                             decl_id: None,
 236                             docs: String::new(),
 237                             sig: None,
 238                             attributes: vec![],
 239                         },
 240                     );
 241                 }
 242             }
 243         }
 244     }
 245
 246     fn process_method(
 247         &mut self,
 248         sig: &'tcx hir::FnSig<'tcx>,
 249         body: Option<hir::BodyId>,
 250         def_id: LocalDefId,
 251         ident: Ident,
 252         generics: &'tcx hir::Generics<'tcx>,
 253         span: Span,
 254     ) {
 255         debug!("process_method: {:?}:{}", def_id, ident);
 256
 257         let map = self.tcx.hir();
 258         let hir_id = map.local_def_id_to_hir_id(def_id);
 259         self.nest_typeck_results(def_id, |v| {
 260             if let Some(mut method_data) = v.save_ctxt.get_method_data(hir_id, ident, span) {
 261                 if let Some(body) = body {
 262                     v.process_formals(map.body(body).params, &method_data.qualname);
 263                 }
 264                 v.process_generic_params(&generics, &method_data.qualname, hir_id);
 265
 266                 method_data.value =
 267                     fn_to_string(sig.decl, sig.header, Some(ident.name), generics, &[], None);
 268                 method_data.sig = sig::method_signature(hir_id, ident, generics, sig, &v.save_ctxt);
 269
 270                 v.dumper.dump_def(&access_from!(v.save_ctxt, def_id), method_data);
 271             }
 272
 273             // walk arg and return types
 274             for arg in sig.decl.inputs {
 275                 v.visit_ty(arg);
 276             }
 277
 278             if let hir::FnRetTy::Return(ref ret_ty) = sig.decl.output {
 279                 v.visit_ty(ret_ty)
 280             }
 281
 282             // walk the fn body
 283             if let Some(body) = body {
 284                 v.visit_expr(&map.body(body).value);
 285             }
 286         });
 287     }
 288
 289     fn process_struct_field_def(
 290         &mut self,
 291         field: &'tcx hir::FieldDef<'tcx>,
 292         parent_id: hir::HirId,
 293     ) {
 294         let field_data = self.save_ctxt.get_field_data(field, parent_id);
 295         if let Some(field_data) = field_data {
 296             self.dumper.dump_def(
 297                 &access_from!(self.save_ctxt, self.tcx.hir().local_def_id(field.hir_id)),
 298                 field_data,
 299             );
 300         }
 301     }
 302
 303     // Dump generic params bindings, then visit_generics
 304     fn process_generic_params(
 305         &mut self,
 306         generics: &'tcx hir::Generics<'tcx>,
 307         prefix: &str,
 308         id: hir::HirId,
 309     ) {
 310         for param in generics.params {
 311             match param.kind {
 312                 hir::GenericParamKind::Lifetime { .. } => {}
 313                 hir::GenericParamKind::Type { .. } => {
 314                     let param_ss = param.name.ident().span;
 315                     let name = escape(self.span.snippet(param_ss));
 316                     // Append $id to name to make sure each one is unique.
 317                     let qualname = format!("{}::{}${}", prefix, name, id);
 318                     if !self.span.filter_generated(param_ss) {
 319                         let id = id_from_hir_id(param.hir_id, &self.save_ctxt);
 320                         let span = self.span_from_span(param_ss);
 321
 322                         self.dumper.dump_def(
 323                             &Access { public: false, reachable: false },
 324                             Def {
 325                                 kind: DefKind::Type,
 326                                 id,
 327                                 span,
 328                                 name,
 329                                 qualname,
 330                                 value: String::new(),
 331                                 parent: None,
 332                                 children: vec![],
 333                                 decl_id: None,
 334                                 docs: String::new(),
 335                                 sig: None,
 336                                 attributes: vec![],
 337                             },
 338                         );
 339                     }
 340                 }
 341                 hir::GenericParamKind::Const { .. } => {}
 342             }
 343         }
 344
 345         self.visit_generics(generics)
 346     }
 347
 348     fn process_fn(
 349         &mut self,
 350         item: &'tcx hir::Item<'tcx>,
 351         decl: &'tcx hir::FnDecl<'tcx>,
 352         _header: &'tcx hir::FnHeader,
 353         ty_params: &'tcx hir::Generics<'tcx>,
 354         body: hir::BodyId,
 355     ) {
 356         let map = self.tcx.hir();
 357         self.nest_typeck_results(item.def_id, |v| {
 358             let body = map.body(body);
 359             if let Some(fn_data) = v.save_ctxt.get_item_data(item) {
 360                 down_cast_data!(fn_data, DefData, item.span);
 361                 v.process_formals(body.params, &fn_data.qualname);
 362                 v.process_generic_params(ty_params, &fn_data.qualname, item.hir_id());
 363
 364                 v.dumper.dump_def(&access_from!(v.save_ctxt, item.def_id), fn_data);
 365             }
 366
 367             for arg in decl.inputs {
 368                 v.visit_ty(arg)
 369             }
 370
 371             if let hir::FnRetTy::Return(ref ret_ty) = decl.output {
 372                 v.visit_ty(ret_ty)
 373             }
 374
 375             v.visit_expr(&body.value);
 376         });
 377     }
 378
 379     fn process_static_or_const_item(
 380         &mut self,
 381         item: &'tcx hir::Item<'tcx>,
 382         typ: &'tcx hir::Ty<'tcx>,
 383         expr: &'tcx hir::Expr<'tcx>,
 384     ) {
 385         self.nest_typeck_results(item.def_id, |v| {
 386             if let Some(var_data) = v.save_ctxt.get_item_data(item) {
 387                 down_cast_data!(var_data, DefData, item.span);
 388                 v.dumper.dump_def(&access_from!(v.save_ctxt, item.def_id), var_data);
 389             }
 390             v.visit_ty(&typ);
 391             v.visit_expr(expr);
 392         });
 393     }
 394
 395     fn process_assoc_const(
 396         &mut self,
 397         def_id: LocalDefId,
 398         ident: Ident,
 399         typ: &'tcx hir::Ty<'tcx>,
 400         expr: Option<&'tcx hir::Expr<'tcx>>,
 401         parent_id: DefId,
 402         attrs: &'tcx [ast::Attribute],
 403     ) {
 404         let qualname = format!("::{}", self.tcx.def_path_str(def_id.to_def_id()));
 405
 406         if !self.span.filter_generated(ident.span) {
 407             let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
 408             let sig = sig::assoc_const_signature(hir_id, ident.name, typ, expr, &self.save_ctxt);
 409             let span = self.span_from_span(ident.span);
 410
 411             self.dumper.dump_def(
 412                 &access_from!(self.save_ctxt, def_id),
 413                 Def {
 414                     kind: DefKind::Const,
 415                     id: id_from_hir_id(hir_id, &self.save_ctxt),
 416                     span,
 417                     name: ident.name.to_string(),
 418                     qualname,
 419                     value: ty_to_string(&typ),
 420                     parent: Some(id_from_def_id(parent_id)),
 421                     children: vec![],
 422                     decl_id: None,
 423                     docs: self.save_ctxt.docs_for_attrs(attrs),
 424                     sig,
 425                     attributes: lower_attributes(attrs.to_owned(), &self.save_ctxt),
 426                 },
 427             );
 428         }
 429
 430         // walk type and init value
 431         self.nest_typeck_results(def_id, |v| {
 432             v.visit_ty(typ);
 433             if let Some(expr) = expr {
 434                 v.visit_expr(expr);
 435             }
 436         });
 437     }
 438
 439     // FIXME tuple structs should generate tuple-specific data.
 440     fn process_struct(
 441         &mut self,
 442         item: &'tcx hir::Item<'tcx>,
 443         def: &'tcx hir::VariantData<'tcx>,
 444         ty_params: &'tcx hir::Generics<'tcx>,
 445     ) {
 446         debug!("process_struct {:?} {:?}", item, item.span);
 447         let name = item.ident.to_string();
 448         let qualname = format!("::{}", self.tcx.def_path_str(item.def_id.to_def_id()));
 449
 450         let kind = match item.kind {
 451             hir::ItemKind::Struct(_, _) => DefKind::Struct,
 452             hir::ItemKind::Union(_, _) => DefKind::Union,
 453             _ => unreachable!(),
 454         };
 455
 456         let (value, fields) = match item.kind {
 457             hir::ItemKind::Struct(hir::VariantData::Struct(ref fields, ..), ..)
 458             | hir::ItemKind::Union(hir::VariantData::Struct(ref fields, ..), ..) => {
 459                 let include_priv_fields = !self.save_ctxt.config.pub_only;
 460                 let fields_str = fields
 461                     .iter()
 462                     .filter_map(|f| {
 463                         if include_priv_fields {
 464                             return Some(f.ident.to_string());
 465                         }
 466                         let def_id = self.save_ctxt.tcx.hir().local_def_id(f.hir_id);
 467                         if self.save_ctxt.tcx.visibility(def_id).is_public() {
 468                             Some(f.ident.to_string())
 469                         } else {
 470                             None
 471                         }
 472                     })
 473                     .collect::<Vec<_>>()
 474                     .join(", ");
 475                 let value = format!("{} {{ {} }}", name, fields_str);
 476                 (value, fields.iter().map(|f| id_from_hir_id(f.hir_id, &self.save_ctxt)).collect())
 477             }
 478             _ => (String::new(), vec![]),
 479         };
 480
 481         if !self.span.filter_generated(item.ident.span) {
 482             let span = self.span_from_span(item.ident.span);
 483             let attrs = self.tcx.hir().attrs(item.hir_id());
 484             self.dumper.dump_def(
 485                 &access_from!(self.save_ctxt, item.def_id),
 486                 Def {
 487                     kind,
 488                     id: id_from_def_id(item.def_id.to_def_id()),
 489                     span,
 490                     name,
 491                     qualname: qualname.clone(),
 492                     value,
 493                     parent: None,
 494                     children: fields,
 495                     decl_id: None,
 496                     docs: self.save_ctxt.docs_for_attrs(attrs),
 497                     sig: sig::item_signature(item, &self.save_ctxt),
 498                     attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 499                 },
 500             );
 501         }
 502
 503         self.nest_typeck_results(item.def_id, |v| {
 504             for field in def.fields() {
 505                 v.process_struct_field_def(field, item.hir_id());
 506                 v.visit_ty(&field.ty);
 507             }
 508
 509             v.process_generic_params(ty_params, &qualname, item.hir_id());
 510         });
 511     }
 512
 513     fn process_enum(
 514         &mut self,
 515         item: &'tcx hir::Item<'tcx>,
 516         enum_definition: &'tcx hir::EnumDef<'tcx>,
 517         ty_params: &'tcx hir::Generics<'tcx>,
 518     ) {
 519         let enum_data = self.save_ctxt.get_item_data(item);
 520         let Some(enum_data) = enum_data else {
 521             return;
 522         };
 523         down_cast_data!(enum_data, DefData, item.span);
 524
 525         let access = access_from!(self.save_ctxt, item.def_id);
 526
 527         for variant in enum_definition.variants {
 528             let name = variant.ident.name.to_string();
 529             let qualname = format!("{}::{}", enum_data.qualname, name);
 530             let name_span = variant.ident.span;
 531
 532             match variant.data {
 533                 hir::VariantData::Struct(ref fields, ..) => {
 534                     let fields_str =
 535                         fields.iter().map(|f| f.ident.to_string()).collect::<Vec<_>>().join(", ");
 536                     let value = format!("{}::{} {{ {} }}", enum_data.name, name, fields_str);
 537                     if !self.span.filter_generated(name_span) {
 538                         let span = self.span_from_span(name_span);
 539                         let id = id_from_hir_id(variant.id, &self.save_ctxt);
 540                         let parent = Some(id_from_def_id(item.def_id.to_def_id()));
 541                         let attrs = self.tcx.hir().attrs(variant.id);
 542
 543                         self.dumper.dump_def(
 544                             &access,
 545                             Def {
 546                                 kind: DefKind::StructVariant,
 547                                 id,
 548                                 span,
 549                                 name,
 550                                 qualname,
 551                                 value,
 552                                 parent,
 553                                 children: vec![],
 554                                 decl_id: None,
 555                                 docs: self.save_ctxt.docs_for_attrs(attrs),
 556                                 sig: sig::variant_signature(variant, &self.save_ctxt),
 557                                 attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 558                             },
 559                         );
 560                     }
 561                 }
 562                 ref v => {
 563                     let mut value = format!("{}::{}", enum_data.name, name);
 564                     if let hir::VariantData::Tuple(fields, _) = v {
 565                         value.push('(');
 566                         value.push_str(
 567                             &fields
 568                                 .iter()
 569                                 .map(|f| ty_to_string(&f.ty))
 570                                 .collect::<Vec<_>>()
 571                                 .join(", "),
 572                         );
 573                         value.push(')');
 574                     }
 575                     if !self.span.filter_generated(name_span) {
 576                         let span = self.span_from_span(name_span);
 577                         let id = id_from_hir_id(variant.id, &self.save_ctxt);
 578                         let parent = Some(id_from_def_id(item.def_id.to_def_id()));
 579                         let attrs = self.tcx.hir().attrs(variant.id);
 580
 581                         self.dumper.dump_def(
 582                             &access,
 583                             Def {
 584                                 kind: DefKind::TupleVariant,
 585                                 id,
 586                                 span,
 587                                 name,
 588                                 qualname,
 589                                 value,
 590                                 parent,
 591                                 children: vec![],
 592                                 decl_id: None,
 593                                 docs: self.save_ctxt.docs_for_attrs(attrs),
 594                                 sig: sig::variant_signature(variant, &self.save_ctxt),
 595                                 attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 596                             },
 597                         );
 598                     }
 599                 }
 600             }
 601
 602             for field in variant.data.fields() {
 603                 self.process_struct_field_def(field, variant.id);
 604                 self.visit_ty(field.ty);
 605             }
 606         }
 607         self.process_generic_params(ty_params, &enum_data.qualname, item.hir_id());
 608         self.dumper.dump_def(&access, enum_data);
 609     }
 610
 611     fn process_impl(&mut self, item: &'tcx hir::Item<'tcx>, impl_: &'tcx hir::Impl<'tcx>) {
 612         if let Some(impl_data) = self.save_ctxt.get_item_data(item) {
 613             if !self.span.filter_generated(item.span) {
 614                 if let super::Data::RelationData(rel, imp) = impl_data {
 615                     self.dumper.dump_relation(rel);
 616                     self.dumper.dump_impl(imp);
 617                 } else {
 618                     span_bug!(item.span, "unexpected data kind: {:?}", impl_data);
 619                 }
 620             }
 621         }
 622
 623         let map = self.tcx.hir();
 624         self.nest_typeck_results(item.def_id, |v| {
 625             v.visit_ty(&impl_.self_ty);
 626             if let Some(trait_ref) = &impl_.of_trait {
 627                 v.process_path(trait_ref.hir_ref_id, &hir::QPath::Resolved(None, &trait_ref.path));
 628             }
 629             v.process_generic_params(&impl_.generics, "", item.hir_id());
 630             for impl_item in impl_.items {
 631                 v.process_impl_item(map.impl_item(impl_item.id), item.def_id.to_def_id());
 632             }
 633         });
 634     }
 635
 636     fn process_trait(
 637         &mut self,
 638         item: &'tcx hir::Item<'tcx>,
 639         generics: &'tcx hir::Generics<'tcx>,
 640         trait_refs: hir::GenericBounds<'tcx>,
 641         methods: &'tcx [hir::TraitItemRef],
 642     ) {
 643         let name = item.ident.to_string();
 644         let qualname = format!("::{}", self.tcx.def_path_str(item.def_id.to_def_id()));
 645         let mut val = name.clone();
 646         if !generics.params.is_empty() {
 647             val.push_str(&generic_params_to_string(generics.params));
 648         }
 649         if !trait_refs.is_empty() {
 650             val.push_str(": ");
 651             val.push_str(&bounds_to_string(trait_refs));
 652         }
 653         if !self.span.filter_generated(item.ident.span) {
 654             let id = id_from_def_id(item.def_id.to_def_id());
 655             let span = self.span_from_span(item.ident.span);
 656             let children =
 657                 methods.iter().map(|i| id_from_def_id(i.id.def_id.to_def_id())).collect();
 658             let attrs = self.tcx.hir().attrs(item.hir_id());
 659             self.dumper.dump_def(
 660                 &access_from!(self.save_ctxt, item.def_id),
 661                 Def {
 662                     kind: DefKind::Trait,
 663                     id,
 664                     span,
 665                     name,
 666                     qualname: qualname.clone(),
 667                     value: val,
 668                     parent: None,
 669                     children,
 670                     decl_id: None,
 671                     docs: self.save_ctxt.docs_for_attrs(attrs),
 672                     sig: sig::item_signature(item, &self.save_ctxt),
 673                     attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
 674                 },
 675             );
 676         }
 677
 678         // supertraits
 679         for super_bound in trait_refs.iter() {
 680             let (def_id, sub_span) = match *super_bound {
 681                 hir::GenericBound::Trait(ref trait_ref, _) => (
 682                     self.lookup_def_id(trait_ref.trait_ref.hir_ref_id),
 683                     trait_ref.trait_ref.path.segments.last().unwrap().ident.span,
 684                 ),
 685                 hir::GenericBound::LangItemTrait(lang_item, span, _, _) => {
 686                     (Some(self.tcx.require_lang_item(lang_item, Some(span))), span)
 687                 }
 688                 hir::GenericBound::Outlives(..) => continue,
 689             };
 690
 691             if let Some(id) = def_id {
 692                 if !self.span.filter_generated(sub_span) {
 693                     let span = self.span_from_span(sub_span);
 694                     self.dumper.dump_ref(Ref {
 695                         kind: RefKind::Type,
 696                         span: span.clone(),
 697                         ref_id: id_from_def_id(id),
 698                     });
 699
 700                     self.dumper.dump_relation(Relation {
 701                         kind: RelationKind::SuperTrait,
 702                         span,
 703                         from: id_from_def_id(id),
 704                         to: id_from_def_id(item.def_id.to_def_id()),
 705                     });
 706                 }
 707             }
 708         }
 709
 710         // walk generics and methods
 711         self.process_generic_params(generics, &qualname, item.hir_id());
 712         for method in methods {
 713             let map = self.tcx.hir();
 714             self.process_trait_item(map.trait_item(method.id), item.def_id.to_def_id())
 715         }
 716     }
 717
 718     // `item` is the module in question, represented as an( item.
 719     fn process_mod(&mut self, item: &'tcx hir::Item<'tcx>) {
 720         if let Some(mod_data) = self.save_ctxt.get_item_data(item) {
 721             down_cast_data!(mod_data, DefData, item.span);
 722             self.dumper.dump_def(&access_from!(self.save_ctxt, item.def_id), mod_data);
 723         }
 724     }
 725
 726     fn dump_path_ref(&mut self, id: hir::HirId, path: &hir::QPath<'tcx>) {
 727         let path_data = self.save_ctxt.get_path_data(id, path);
 728         if let Some(path_data) = path_data {
 729             self.dumper.dump_ref(path_data);
 730         }
 731     }
 732
 733     fn dump_path_segment_ref(&mut self, id: hir::HirId, segment: &hir::PathSegment<'tcx>) {
 734         let segment_data = self.save_ctxt.get_path_segment_data_with_id(segment, id);
 735         if let Some(segment_data) = segment_data {
 736             self.dumper.dump_ref(segment_data);
 737         }
 738     }
 739
 740     fn process_path(&mut self, id: hir::HirId, path: &hir::QPath<'tcx>) {
 741         if self.span.filter_generated(path.span()) {
 742             return;
 743         }
 744         self.dump_path_ref(id, path);
 745
 746         // Type arguments
 747         let segments = match path {
 748             hir::QPath::Resolved(ty, path) => {
 749                 if let Some(ty) = ty {
 750                     self.visit_ty(ty);
 751                 }
 752                 path.segments
 753             }
 754             hir::QPath::TypeRelative(ty, segment) => {
 755                 self.visit_ty(ty);
 756                 std::slice::from_ref(*segment)
 757             }
 758             hir::QPath::LangItem(..) => return,
 759         };
 760         for seg in segments {
 761             if let Some(ref generic_args) = seg.args {
 762                 for arg in generic_args.args {
 763                     if let hir::GenericArg::Type(ref ty) = arg {
 764                         self.visit_ty(ty);
 765                     }
 766                 }
 767             }
 768         }
 769
 770         if let hir::QPath::Resolved(_, path) = path {
 771             self.write_sub_paths_truncated(path);
 772         }
 773     }
 774
 775     fn process_struct_lit(
 776         &mut self,
 777         ex: &'tcx hir::Expr<'tcx>,
 778         path: &'tcx hir::QPath<'tcx>,
 779         fields: &'tcx [hir::ExprField<'tcx>],
 780         variant: &'tcx ty::VariantDef,
 781         rest: Option<&'tcx hir::Expr<'tcx>>,
 782     ) {
 783         if let Some(struct_lit_data) = self.save_ctxt.get_expr_data(ex) {
 784             if let hir::QPath::Resolved(_, path) = path {
 785                 self.write_sub_paths_truncated(path);
 786             }
 787             down_cast_data!(struct_lit_data, RefData, ex.span);
 788             if !generated_code(ex.span) {
 789                 self.dumper.dump_ref(struct_lit_data);
 790             }
 791
 792             for field in fields {
 793                 if let Some(field_data) = self.save_ctxt.get_field_ref_data(field, variant) {
 794                     self.dumper.dump_ref(field_data);
 795                 }
 796
 797                 self.visit_expr(&field.expr)
 798             }
 799         }
 800
 801         if let Some(base) = rest {
 802             self.visit_expr(&base);
 803         }
 804     }
 805
 806     fn process_method_call(
 807         &mut self,
 808         ex: &'tcx hir::Expr<'tcx>,
 809         seg: &'tcx hir::PathSegment<'tcx>,
 810         args: &'tcx [hir::Expr<'tcx>],
 811     ) {
 812         debug!("process_method_call {:?} {:?}", ex, ex.span);
 813         if let Some(mcd) = self.save_ctxt.get_expr_data(ex) {
 814             down_cast_data!(mcd, RefData, ex.span);
 815             if !generated_code(ex.span) {
 816                 self.dumper.dump_ref(mcd);
 817             }
 818         }
 819
 820         // Explicit types in the turbo-fish.
 821         if let Some(generic_args) = seg.args {
 822             for arg in generic_args.args {
 823                 if let hir::GenericArg::Type(ty) = arg {
 824                     self.visit_ty(&ty)
 825                 };
 826             }
 827         }
 828
 829         // walk receiver and args
 830         walk_list!(self, visit_expr, args);
 831     }
 832
 833     fn process_pat(&mut self, p: &'tcx hir::Pat<'tcx>) {
 834         match p.kind {
 835             hir::PatKind::Struct(ref _path, fields, _) => {
 836                 // FIXME do something with _path?
 837                 let adt = match self.save_ctxt.typeck_results().node_type_opt(p.hir_id) {
 838                     Some(ty) if ty.ty_adt_def().is_some() => ty.ty_adt_def().unwrap(),
 839                     _ => {
 840                         intravisit::walk_pat(self, p);
 841                         return;
 842                     }
 843                 };
 844                 let variant = adt.variant_of_res(self.save_ctxt.get_path_res(p.hir_id));
 845
 846                 for field in fields {
 847                     if let Some(index) = self.tcx.find_field_index(field.ident, variant) {
 848                         if !self.span.filter_generated(field.ident.span) {
 849                             let span = self.span_from_span(field.ident.span);
 850                             self.dumper.dump_ref(Ref {
 851                                 kind: RefKind::Variable,
 852                                 span,
 853                                 ref_id: id_from_def_id(variant.fields[index].did),
 854                             });
 855                         }
 856                     }
 857                     self.visit_pat(&field.pat);
 858                 }
 859             }
 860             _ => intravisit::walk_pat(self, p),
 861         }
 862     }
 863
 864     fn process_var_decl(&mut self, pat: &'tcx hir::Pat<'tcx>) {
 865         // The pattern could declare multiple new vars,
 866         // we must walk the pattern and collect them all.
 867         let mut collector = PathCollector::new(self.tcx);
 868         collector.visit_pat(&pat);
 869         self.visit_pat(&pat);
 870
 871         // Process collected paths.
 872         for (id, ident, _) in collector.collected_idents {
 873             let res = self.save_ctxt.get_path_res(id);
 874             match res {
 875                 Res::Local(hir_id) => {
 876                     let typ = self
 877                         .save_ctxt
 878                         .typeck_results()
 879                         .node_type_opt(hir_id)
 880                         .map(|t| t.to_string())
 881                         .unwrap_or_default();
 882
 883                     // Rust uses the id of the pattern for var lookups, so we'll use it too.
 884                     if !self.span.filter_generated(ident.span) {
 885                         let qualname = format!("{}${}", ident, hir_id);
 886                         let id = id_from_hir_id(hir_id, &self.save_ctxt);
 887                         let span = self.span_from_span(ident.span);
 888
 889                         self.dumper.dump_def(
 890                             &Access { public: false, reachable: false },
 891                             Def {
 892                                 kind: DefKind::Local,
 893                                 id,
 894                                 span,
 895                                 name: ident.to_string(),
 896                                 qualname,
 897                                 value: typ,
 898                                 parent: None,
 899                                 children: vec![],
 900                                 decl_id: None,
 901                                 docs: String::new(),
 902                                 sig: None,
 903                                 attributes: vec![],
 904                             },
 905                         );
 906                     }
 907                 }
 908                 Res::Def(
 909                     HirDefKind::Ctor(..)
 910                     | HirDefKind::Const
 911                     | HirDefKind::AssocConst
 912                     | HirDefKind::Struct
 913                     | HirDefKind::Variant
 914                     | HirDefKind::TyAlias
 915                     | HirDefKind::AssocTy,
 916                     _,
 917                 )
 918                 | Res::SelfTy { .. } => {
 919                     self.dump_path_segment_ref(id, &hir::PathSegment::from_ident(ident));
 920                 }
 921                 def => {
 922                     error!("unexpected definition kind when processing collected idents: {:?}", def)
 923                 }
 924             }
 925         }
 926
 927         for (id, ref path) in collector.collected_paths {
 928             self.process_path(id, path);
 929         }
 930     }
 931
 932     /// Extracts macro use and definition information from the AST node defined
 933     /// by the given NodeId, using the expansion information from the node's
 934     /// span.
 935     ///
 936     /// If the span is not macro-generated, do nothing, else use callee and
 937     /// callsite spans to record macro definition and use data, using the
 938     /// mac_uses and mac_defs sets to prevent multiples.
 939     fn process_macro_use(&mut self, _span: Span) {
 940         // FIXME if we're not dumping the defs (see below), there is no point
 941         // dumping refs either.
 942         // let source_span = span.source_callsite();
 943         // if !self.macro_calls.insert(source_span) {
 944         //     return;
 945         // }
 946
 947         // let data = match self.save_ctxt.get_macro_use_data(span) {
 948         //     None => return,
 949         //     Some(data) => data,
 950         // };
 951
 952         // self.dumper.macro_use(data);
 953
 954         // FIXME write the macro def
 955         // let mut hasher = DefaultHasher::new();
 956         // data.callee_span.hash(&mut hasher);
 957         // let hash = hasher.finish();
 958         // let qualname = format!("{}::{}", data.name, hash);
 959         // Don't write macro definition for imported macros
 960         // if !self.mac_defs.contains(&data.callee_span)
 961         //     && !data.imported {
 962         //     self.mac_defs.insert(data.callee_span);
 963         //     if let Some(sub_span) = self.span.span_for_macro_def_name(data.callee_span) {
 964         //         self.dumper.macro_data(MacroData {
 965         //             span: sub_span,
 966         //             name: data.name.clone(),
 967         //             qualname: qualname.clone(),
 968         //             // FIXME where do macro docs come from?
 969         //             docs: String::new(),
 970         //         }.lower(self.tcx));
 971         //     }
 972         // }
 973     }
 974
 975     fn process_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>, trait_id: DefId) {
 976         self.process_macro_use(trait_item.span);
 977         match trait_item.kind {
 978             hir::TraitItemKind::Const(ref ty, body) => {
 979                 let body = body.map(|b| &self.tcx.hir().body(b).value);
 980                 let attrs = self.tcx.hir().attrs(trait_item.hir_id());
 981                 self.process_assoc_const(
 982                     trait_item.def_id,
 983                     trait_item.ident,
 984                     &ty,
 985                     body,
 986                     trait_id,
 987                     attrs,
 988                 );
 989             }
 990             hir::TraitItemKind::Fn(ref sig, ref trait_fn) => {
 991                 let body =
 992                     if let hir::TraitFn::Provided(body) = trait_fn { Some(*body) } else { None };
 993                 self.process_method(
 994                     sig,
 995                     body,
 996                     trait_item.def_id,
 997                     trait_item.ident,
 998                     &trait_item.generics,
 999                     trait_item.span,
1000                 );
1001             }
1002             hir::TraitItemKind::Type(ref bounds, ref default_ty) => {
1003                 // FIXME do something with _bounds (for type refs)
1004                 let name = trait_item.ident.name.to_string();
1005                 let qualname =
1006                     format!("::{}", self.tcx.def_path_str(trait_item.def_id.to_def_id()));
1007
1008                 if !self.span.filter_generated(trait_item.ident.span) {
1009                     let span = self.span_from_span(trait_item.ident.span);
1010                     let id = id_from_def_id(trait_item.def_id.to_def_id());
1011                     let attrs = self.tcx.hir().attrs(trait_item.hir_id());
1012
1013                     self.dumper.dump_def(
1014                         &Access { public: true, reachable: true },
1015                         Def {
1016                             kind: DefKind::Type,
1017                             id,
1018                             span,
1019                             name,
1020                             qualname,
1021                             value: self.span.snippet(trait_item.span),
1022                             parent: Some(id_from_def_id(trait_id)),
1023                             children: vec![],
1024                             decl_id: None,
1025                             docs: self.save_ctxt.docs_for_attrs(attrs),
1026                             sig: sig::assoc_type_signature(
1027                                 trait_item.hir_id(),
1028                                 trait_item.ident,
1029                                 Some(bounds),
1030                                 default_ty.as_ref().map(|ty| &**ty),
1031                                 &self.save_ctxt,
1032                             ),
1033                             attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
1034                         },
1035                     );
1036                 }
1037
1038                 if let Some(default_ty) = default_ty {
1039                     self.visit_ty(default_ty)
1040                 }
1041             }
1042         }
1043     }
1044
1045     fn process_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>, impl_id: DefId) {
1046         self.process_macro_use(impl_item.span);
1047         match impl_item.kind {
1048             hir::ImplItemKind::Const(ref ty, body) => {
1049                 let body = self.tcx.hir().body(body);
1050                 let attrs = self.tcx.hir().attrs(impl_item.hir_id());
1051                 self.process_assoc_const(
1052                     impl_item.def_id,
1053                     impl_item.ident,
1054                     &ty,
1055                     Some(&body.value),
1056                     impl_id,
1057                     attrs,
1058                 );
1059             }
1060             hir::ImplItemKind::Fn(ref sig, body) => {
1061                 self.process_method(
1062                     sig,
1063                     Some(body),
1064                     impl_item.def_id,
1065                     impl_item.ident,
1066                     &impl_item.generics,
1067                     impl_item.span,
1068                 );
1069             }
1070             hir::ImplItemKind::TyAlias(ref ty) => {
1071                 // FIXME: uses of the assoc type should ideally point to this
1072                 // 'def' and the name here should be a ref to the def in the
1073                 // trait.
1074                 self.visit_ty(ty)
1075             }
1076         }
1077     }
1078
1079     pub(crate) fn process_crate(&mut self) {
1080         let id = hir::CRATE_HIR_ID;
1081         let qualname =
1082             format!("::{}", self.tcx.def_path_str(self.tcx.hir().local_def_id(id).to_def_id()));
1083
1084         let sm = self.tcx.sess.source_map();
1085         let krate_mod = self.tcx.hir().root_module();
1086         let filename = sm.span_to_filename(krate_mod.spans.inner_span);
1087         let data_id = id_from_hir_id(id, &self.save_ctxt);
1088         let children =
1089             krate_mod.item_ids.iter().map(|i| id_from_def_id(i.def_id.to_def_id())).collect();
1090         let span = self.span_from_span(krate_mod.spans.inner_span);
1091         let attrs = self.tcx.hir().attrs(id);
1092
1093         self.dumper.dump_def(
1094             &Access { public: true, reachable: true },
1095             Def {
1096                 kind: DefKind::Mod,
1097                 id: data_id,
1098                 name: String::new(),
1099                 qualname,
1100                 span,
1101                 value: filename.prefer_remapped().to_string(),
1102                 children,
1103                 parent: None,
1104                 decl_id: None,
1105                 docs: self.save_ctxt.docs_for_attrs(attrs),
1106                 sig: None,
1107                 attributes: lower_attributes(attrs.to_owned(), &self.save_ctxt),
1108             },
1109         );
1110         self.tcx.hir().walk_toplevel_module(self);
1111     }
1112
1113     fn process_bounds(&mut self, bounds: hir::GenericBounds<'tcx>) {
1114         for bound in bounds {
1115             if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1116                 self.process_path(
1117                     trait_ref.trait_ref.hir_ref_id,
1118                     &hir::QPath::Resolved(None, &trait_ref.trait_ref.path),
1119                 )
1120             }
1121         }
1122     }
1123 }
1124
1125 impl<'tcx> Visitor<'tcx> for DumpVisitor<'tcx> {
1126     type NestedFilter = nested_filter::All;
1127
1128     fn nested_visit_map(&mut self) -> Self::Map {
1129         self.tcx.hir()
1130     }
1131
1132     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1133         self.process_macro_use(item.span);
1134         match item.kind {
1135             hir::ItemKind::Use(path, hir::UseKind::Single) => {
1136                 let sub_span = path.segments.last().unwrap().ident.span;
1137                 if !self.span.filter_generated(sub_span) {
1138                     let access = access_from!(self.save_ctxt, item.def_id);
1139                     let ref_id = self.lookup_def_id(item.hir_id()).map(id_from_def_id);
1140                     let span = self.span_from_span(sub_span);
1141                     let parent = self.save_ctxt.tcx.local_parent(item.def_id);
1142                     self.dumper.import(
1143                         &access,
1144                         Import {
1145                             kind: ImportKind::Use,
1146                             ref_id,
1147                             span,
1148                             alias_span: None,
1149                             name: item.ident.to_string(),
1150                             value: String::new(),
1151                             parent: Some(id_from_def_id(parent.to_def_id())),
1152                         },
1153                     );
1154                     self.write_sub_paths_truncated(&path);
1155                 }
1156             }
1157             hir::ItemKind::Use(path, hir::UseKind::Glob) => {
1158                 // Make a comma-separated list of names of imported modules.
1159                 let names = self.tcx.names_imported_by_glob_use(item.def_id);
1160                 let names: Vec<_> = names.iter().map(|n| n.to_string()).collect();
1161
1162                 // Otherwise it's a span with wrong macro expansion info, which
1163                 // we don't want to track anyway, since it's probably macro-internal `use`
1164                 if let Some(sub_span) = self.span.sub_span_of_star(item.span) {
1165                     if !self.span.filter_generated(item.span) {
1166                         let access = access_from!(self.save_ctxt, item.def_id);
1167                         let span = self.span_from_span(sub_span);
1168                         let parent = self.save_ctxt.tcx.local_parent(item.def_id);
1169                         self.dumper.import(
1170                             &access,
1171                             Import {
1172                                 kind: ImportKind::GlobUse,
1173                                 ref_id: None,
1174                                 span,
1175                                 alias_span: None,
1176                                 name: "*".to_owned(),
1177                                 value: names.join(", "),
1178                                 parent: Some(id_from_def_id(parent.to_def_id())),
1179                             },
1180                         );
1181                         self.write_sub_paths(&path);
1182                     }
1183                 }
1184             }
1185             hir::ItemKind::ExternCrate(_) => {
1186                 let name_span = item.ident.span;
1187                 if !self.span.filter_generated(name_span) {
1188                     let span = self.span_from_span(name_span);
1189                     let parent = self.save_ctxt.tcx.local_parent(item.def_id);
1190                     self.dumper.import(
1191                         &Access { public: false, reachable: false },
1192                         Import {
1193                             kind: ImportKind::ExternCrate,
1194                             ref_id: None,
1195                             span,
1196                             alias_span: None,
1197                             name: item.ident.to_string(),
1198                             value: String::new(),
1199                             parent: Some(id_from_def_id(parent.to_def_id())),
1200                         },
1201                     );
1202                 }
1203             }
1204             hir::ItemKind::Fn(ref sig, ref ty_params, body) => {
1205                 self.process_fn(item, sig.decl, &sig.header, ty_params, body)
1206             }
1207             hir::ItemKind::Static(ref typ, _, body) => {
1208                 let body = self.tcx.hir().body(body);
1209                 self.process_static_or_const_item(item, typ, &body.value)
1210             }
1211             hir::ItemKind::Const(ref typ, body) => {
1212                 let body = self.tcx.hir().body(body);
1213                 self.process_static_or_const_item(item, typ, &body.value)
1214             }
1215             hir::ItemKind::Struct(ref def, ref ty_params)
1216             | hir::ItemKind::Union(ref def, ref ty_params) => {
1217                 self.process_struct(item, def, ty_params)
1218             }
1219             hir::ItemKind::Enum(ref def, ref ty_params) => self.process_enum(item, def, ty_params),
1220             hir::ItemKind::Impl(ref impl_) => self.process_impl(item, impl_),
1221             hir::ItemKind::Trait(_, _, ref generics, ref trait_refs, methods) => {
1222                 self.process_trait(item, generics, trait_refs, methods)
1223             }
1224             hir::ItemKind::Mod(ref m) => {
1225                 self.process_mod(item);
1226                 intravisit::walk_mod(self, m, item.hir_id());
1227             }
1228             hir::ItemKind::TyAlias(ty, ref generics) => {
1229                 let qualname = format!("::{}", self.tcx.def_path_str(item.def_id.to_def_id()));
1230                 let value = ty_to_string(&ty);
1231                 if !self.span.filter_generated(item.ident.span) {
1232                     let span = self.span_from_span(item.ident.span);
1233                     let id = id_from_def_id(item.def_id.to_def_id());
1234                     let attrs = self.tcx.hir().attrs(item.hir_id());
1235
1236                     self.dumper.dump_def(
1237                         &access_from!(self.save_ctxt, item.def_id),
1238                         Def {
1239                             kind: DefKind::Type,
1240                             id,
1241                             span,
1242                             name: item.ident.to_string(),
1243                             qualname: qualname.clone(),
1244                             value,
1245                             parent: None,
1246                             children: vec![],
1247                             decl_id: None,
1248                             docs: self.save_ctxt.docs_for_attrs(attrs),
1249                             sig: sig::item_signature(item, &self.save_ctxt),
1250                             attributes: lower_attributes(attrs.to_vec(), &self.save_ctxt),
1251                         },
1252                     );
1253                 }
1254
1255                 self.visit_ty(ty);
1256                 self.process_generic_params(generics, &qualname, item.hir_id());
1257             }
1258             _ => intravisit::walk_item(self, item),
1259         }
1260     }
1261
1262     fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1263         for param in generics.params {
1264             match param.kind {
1265                 hir::GenericParamKind::Lifetime { .. } => {}
1266                 hir::GenericParamKind::Type { ref default, .. } => {
1267                     if let Some(ref ty) = default {
1268                         self.visit_ty(ty);
1269                     }
1270                 }
1271                 hir::GenericParamKind::Const { ref ty, ref default } => {
1272                     self.visit_ty(ty);
1273                     if let Some(default) = default {
1274                         self.visit_anon_const(default);
1275                     }
1276                 }
1277             }
1278         }
1279         for pred in generics.predicates {
1280             if let hir::WherePredicate::BoundPredicate(ref wbp) = *pred {
1281                 self.process_bounds(wbp.bounds);
1282                 self.visit_ty(wbp.bounded_ty);
1283             }
1284         }
1285     }
1286
1287     fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1288         self.process_macro_use(t.span);
1289         match t.kind {
1290             hir::TyKind::Path(ref path) => {
1291                 if generated_code(t.span) {
1292                     return;
1293                 }
1294
1295                 if let Some(id) = self.lookup_def_id(t.hir_id) {
1296                     let sub_span = path.last_segment_span();
1297                     let span = self.span_from_span(sub_span);
1298                     self.dumper.dump_ref(Ref {
1299                         kind: RefKind::Type,
1300                         span,
1301                         ref_id: id_from_def_id(id),
1302                     });
1303                 }
1304
1305                 if let hir::QPath::Resolved(_, path) = path {
1306                     self.write_sub_paths_truncated(path);
1307                 }
1308                 intravisit::walk_qpath(self, path, t.hir_id, t.span);
1309             }
1310             hir::TyKind::Array(ref ty, ref length) => {
1311                 self.visit_ty(ty);
1312                 let map = self.tcx.hir();
1313                 match length {
1314                     // FIXME(generic_arg_infer): We probably want to
1315                     // output the inferred type here? :shrug:
1316                     hir::ArrayLen::Infer(..) => {}
1317                     hir::ArrayLen::Body(anon_const) => self
1318                         .nest_typeck_results(self.tcx.hir().local_def_id(anon_const.hir_id), |v| {
1319                             v.visit_expr(&map.body(anon_const.body).value)
1320                         }),
1321                 }
1322             }
1323             hir::TyKind::OpaqueDef(item_id, _) => {
1324                 let item = self.tcx.hir().item(item_id);
1325                 self.nest_typeck_results(item_id.def_id, |v| v.visit_item(item));
1326             }
1327             _ => intravisit::walk_ty(self, t),
1328         }
1329     }
1330
1331     fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
1332         debug!("visit_expr {:?}", ex.kind);
1333         self.process_macro_use(ex.span);
1334         match ex.kind {
1335             hir::ExprKind::Struct(ref path, ref fields, ref rest) => {
1336                 let hir_expr = self.save_ctxt.tcx.hir().expect_expr(ex.hir_id);
1337                 let adt = match self.save_ctxt.typeck_results().expr_ty_opt(&hir_expr) {
1338                     Some(ty) if ty.ty_adt_def().is_some() => ty.ty_adt_def().unwrap(),
1339                     _ => {
1340                         intravisit::walk_expr(self, ex);
1341                         return;
1342                     }
1343                 };
1344                 let res = self.save_ctxt.get_path_res(hir_expr.hir_id);
1345                 self.process_struct_lit(ex, path, fields, adt.variant_of_res(res), *rest)
1346             }
1347             hir::ExprKind::MethodCall(ref seg, args, _) => self.process_method_call(ex, seg, args),
1348             hir::ExprKind::Field(ref sub_ex, _) => {
1349                 self.visit_expr(&sub_ex);
1350
1351                 if let Some(field_data) = self.save_ctxt.get_expr_data(ex) {
1352                     down_cast_data!(field_data, RefData, ex.span);
1353                     if !generated_code(ex.span) {
1354                         self.dumper.dump_ref(field_data);
1355                     }
1356                 }
1357             }
1358             hir::ExprKind::Closure(_, ref decl, body, _fn_decl_span, _) => {
1359                 let id = format!("${}", ex.hir_id);
1360
1361                 // walk arg and return types
1362                 for ty in decl.inputs {
1363                     self.visit_ty(ty);
1364                 }
1365
1366                 if let hir::FnRetTy::Return(ref ret_ty) = decl.output {
1367                     self.visit_ty(ret_ty);
1368                 }
1369
1370                 // walk the body
1371                 let map = self.tcx.hir();
1372                 self.nest_typeck_results(self.tcx.hir().local_def_id(ex.hir_id), |v| {
1373                     let body = map.body(body);
1374                     v.process_formals(body.params, &id);
1375                     v.visit_expr(&body.value)
1376                 });
1377             }
1378             hir::ExprKind::Repeat(ref expr, ref length) => {
1379                 self.visit_expr(expr);
1380                 let map = self.tcx.hir();
1381                 match length {
1382                     // FIXME(generic_arg_infer): We probably want to
1383                     // output the inferred type here? :shrug:
1384                     hir::ArrayLen::Infer(..) => {}
1385                     hir::ArrayLen::Body(anon_const) => self
1386                         .nest_typeck_results(self.tcx.hir().local_def_id(anon_const.hir_id), |v| {
1387                             v.visit_expr(&map.body(anon_const.body).value)
1388                         }),
1389                 }
1390             }
1391             // In particular, we take this branch for call and path expressions,
1392             // where we'll index the idents involved just by continuing to walk.
1393             _ => intravisit::walk_expr(self, ex),
1394         }
1395     }
1396
1397     fn visit_pat(&mut self, p: &'tcx hir::Pat<'tcx>) {
1398         self.process_macro_use(p.span);
1399         self.process_pat(p);
1400     }
1401
1402     fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) {
1403         self.process_var_decl(&arm.pat);
1404         if let Some(hir::Guard::If(expr)) = &arm.guard {
1405             self.visit_expr(expr);
1406         }
1407         self.visit_expr(&arm.body);
1408     }
1409
1410     fn visit_qpath(&mut self, path: &'tcx hir::QPath<'tcx>, id: hir::HirId, _: Span) {
1411         self.process_path(id, path);
1412     }
1413
1414     fn visit_stmt(&mut self, s: &'tcx hir::Stmt<'tcx>) {
1415         self.process_macro_use(s.span);
1416         intravisit::walk_stmt(self, s)
1417     }
1418
1419     fn visit_local(&mut self, l: &'tcx hir::Local<'tcx>) {
1420         self.process_macro_use(l.span);
1421         self.process_var_decl(&l.pat);
1422
1423         // Just walk the initializer and type (don't want to walk the pattern again).
1424         walk_list!(self, visit_ty, &l.ty);
1425         walk_list!(self, visit_expr, &l.init);
1426     }
1427
1428     fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1429         let access = access_from!(self.save_ctxt, item.def_id);
1430
1431         match item.kind {
1432             hir::ForeignItemKind::Fn(decl, _, ref generics) => {
1433                 if let Some(fn_data) = self.save_ctxt.get_extern_item_data(item) {
1434                     down_cast_data!(fn_data, DefData, item.span);
1435
1436                     self.process_generic_params(generics, &fn_data.qualname, item.hir_id());
1437                     self.dumper.dump_def(&access, fn_data);
1438                 }
1439
1440                 for ty in decl.inputs {
1441                     self.visit_ty(ty);
1442                 }
1443
1444                 if let hir::FnRetTy::Return(ref ret_ty) = decl.output {
1445                     self.visit_ty(ret_ty);
1446                 }
1447             }
1448             hir::ForeignItemKind::Static(ref ty, _) => {
1449                 if let Some(var_data) = self.save_ctxt.get_extern_item_data(item) {
1450                     down_cast_data!(var_data, DefData, item.span);
1451                     self.dumper.dump_def(&access, var_data);
1452                 }
1453
1454                 self.visit_ty(ty);
1455             }
1456             hir::ForeignItemKind::Type => {
1457                 if let Some(var_data) = self.save_ctxt.get_extern_item_data(item) {
1458                     down_cast_data!(var_data, DefData, item.span);
1459                     self.dumper.dump_def(&access, var_data);
1460                 }
1461             }
1462         }
1463     }
1464 }