src/librustc_save_analysis/dump_visitor.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! Write the output of rustc's analysis to an implementor of Dump. The data is
  12 //! primarily designed to be used as input to the DXR tool, specifically its
  13 //! Rust plugin. It could also be used by IDEs or other code browsing, search, or
  14 //! cross-referencing tools.
  15 //!
  16 //! Dumping the analysis is implemented by walking the AST and getting a bunch of
  17 //! info out from all over the place. We use Def IDs to identify objects. The
  18 //! tricky part is getting syntactic (span, source text) and semantic (reference
  19 //! Def IDs) information for parts of expressions which the compiler has discarded.
  20 //! E.g., in a path `foo::bar::baz`, the compiler only keeps a span for the whole
  21 //! path and a reference to `baz`, but we want spans and references for all three
  22 //! idents.
  23 //!
  24 //! SpanUtils is used to manipulate spans. In particular, to extract sub-spans
  25 //! from spans (e.g., the span for `bar` from the above example path).
  26 //! DumpVisitor walks the AST and processes it, and an implementor of Dump
  27 //! is used for recording the output in a format-agnostic way (see CsvDumper
  28 //! for an example).
  29
  30 use rustc::hir;
  31 use rustc::hir::def::Def;
  32 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
  33 use rustc::hir::map::{Node, NodeItem};
  34 use rustc::session::Session;
  35 use rustc::ty::{self, TyCtxt, AssociatedItemContainer};
  36
  37 use std::collections::HashSet;
  38 use std::collections::hash_map::DefaultHasher;
  39 use std::hash::*;
  40
  41 use syntax::ast::{self, NodeId, PatKind, Attribute, CRATE_NODE_ID};
  42 use syntax::parse::token;
  43 use syntax::symbol::keywords;
  44 use syntax::visit::{self, Visitor};
  45 use syntax::print::pprust::{path_to_string, ty_to_string, bounds_to_string, generics_to_string};
  46 use syntax::ptr::P;
  47 use syntax::codemap::Spanned;
  48 use syntax_pos::*;
  49
  50 use super::{escape, generated_code, SaveContext, PathCollector, docs_for_attrs};
  51 use super::data::*;
  52 use super::dump::Dump;
  53 use super::external_data::{Lower, make_def_id};
  54 use super::span_utils::SpanUtils;
  55 use super::recorder;
  56
  57 use rls_data::ExternalCrateData;
  58
  59 macro_rules! down_cast_data {
  60     ($id:ident, $kind:ident, $sp:expr) => {
  61         let $id = if let super::Data::$kind(data) = $id {
  62             data
  63         } else {
  64             span_bug!($sp, "unexpected data kind: {:?}", $id);
  65         };
  66     };
  67 }
  68
  69 pub struct DumpVisitor<'l, 'tcx: 'l, 'll, D: 'll> {
  70     save_ctxt: SaveContext<'l, 'tcx>,
  71     sess: &'l Session,
  72     tcx: TyCtxt<'l, 'tcx, 'tcx>,
  73     dumper: &'ll mut D,
  74
  75     span: SpanUtils<'l>,
  76
  77     cur_scope: NodeId,
  78
  79     // Set of macro definition (callee) spans, and the set
  80     // of macro use (callsite) spans. We store these to ensure
  81     // we only write one macro def per unique macro definition, and
  82     // one macro use per unique callsite span.
  83     mac_defs: HashSet<Span>,
  84     mac_uses: HashSet<Span>,
  85 }
  86
  87 impl<'l, 'tcx: 'l, 'll, D: Dump + 'll> DumpVisitor<'l, 'tcx, 'll, D> {
  88     pub fn new(save_ctxt: SaveContext<'l, 'tcx>,
  89                dumper: &'ll mut D)
  90                -> DumpVisitor<'l, 'tcx, 'll, D> {
  91         let span_utils = SpanUtils::new(&save_ctxt.tcx.sess);
  92         DumpVisitor {
  93             sess: &save_ctxt.tcx.sess,
  94             tcx: save_ctxt.tcx,
  95             save_ctxt: save_ctxt,
  96             dumper: dumper,
  97             span: span_utils.clone(),
  98             cur_scope: CRATE_NODE_ID,
  99             mac_defs: HashSet::new(),
 100             mac_uses: HashSet::new(),
 101         }
 102     }
 103
 104     fn nest_scope<F>(&mut self, scope_id: NodeId, f: F)
 105         where F: FnOnce(&mut DumpVisitor<'l, 'tcx, 'll, D>)
 106     {
 107         let parent_scope = self.cur_scope;
 108         self.cur_scope = scope_id;
 109         f(self);
 110         self.cur_scope = parent_scope;
 111     }
 112
 113     fn nest_tables<F>(&mut self, item_id: NodeId, f: F)
 114         where F: FnOnce(&mut DumpVisitor<'l, 'tcx, 'll, D>)
 115     {
 116         let item_def_id = self.tcx.hir.local_def_id(item_id);
 117         match self.tcx.maps.typeck_tables.borrow().get(&item_def_id) {
 118             Some(tables) => {
 119                 let old_tables = self.save_ctxt.tables;
 120                 self.save_ctxt.tables = tables;
 121                 f(self);
 122                 self.save_ctxt.tables = old_tables;
 123             }
 124             None => f(self),
 125         }
 126     }
 127
 128     pub fn dump_crate_info(&mut self, name: &str, krate: &ast::Crate) {
 129         let source_file = self.tcx.sess.local_crate_source_file.as_ref();
 130         let crate_root = source_file.map(|source_file| {
 131             match source_file.file_name() {
 132                 Some(_) => source_file.parent().unwrap().display().to_string(),
 133                 None => source_file.display().to_string(),
 134             }
 135         });
 136
 137         // Info about all the external crates referenced from this crate.
 138         let external_crates = self.save_ctxt.get_external_crates().into_iter().map(|c| {
 139             let lo_loc = self.span.sess.codemap().lookup_char_pos(c.span.lo);
 140             ExternalCrateData {
 141                 name: c.name,
 142                 num: c.number,
 143                 file_name: SpanUtils::make_path_string(&lo_loc.file.name),
 144             }
 145         }).collect();
 146
 147         // The current crate.
 148         let data = CratePreludeData {
 149             crate_name: name.into(),
 150             crate_root: crate_root.unwrap_or("<no source>".to_owned()),
 151             external_crates: external_crates,
 152             span: krate.span,
 153         };
 154
 155         self.dumper.crate_prelude(data.lower(self.tcx));
 156     }
 157
 158     // Return all non-empty prefixes of a path.
 159     // For each prefix, we return the span for the last segment in the prefix and
 160     // a str representation of the entire prefix.
 161     fn process_path_prefixes(&self, path: &ast::Path) -> Vec<(Span, String)> {
 162         let spans = self.span.spans_for_path_segments(path);
 163         let segments = &path.segments[if path.is_global() { 1 } else { 0 }..];
 164
 165         // Paths to enums seem to not match their spans - the span includes all the
 166         // variants too. But they seem to always be at the end, so I hope we can cope with
 167         // always using the first ones. So, only error out if we don't have enough spans.
 168         // What could go wrong...?
 169         if spans.len() < segments.len() {
 170             if generated_code(path.span) {
 171                 return vec![];
 172             }
 173             error!("Mis-calculated spans for path '{}'. Found {} spans, expected {}. Found spans:",
 174                    path_to_string(path),
 175                    spans.len(),
 176                    segments.len());
 177             for s in &spans {
 178                 let loc = self.sess.codemap().lookup_char_pos(s.lo);
 179                 error!("    '{}' in {}, line {}",
 180                        self.span.snippet(*s),
 181                        loc.file.name,
 182                        loc.line);
 183             }
 184             error!("    master span: {:?}: `{}`", path.span, self.span.snippet(path.span));
 185             return vec![];
 186         }
 187
 188         let mut result: Vec<(Span, String)> = vec![];
 189
 190         let mut segs = vec![];
 191         for (i, (seg, span)) in segments.iter().zip(&spans).enumerate() {
 192             segs.push(seg.clone());
 193             let sub_path = ast::Path {
 194                 span: *span, // span for the last segment
 195                 segments: segs,
 196             };
 197             let qualname = if i == 0 && path.is_global() {
 198                 format!("::{}", path_to_string(&sub_path))
 199             } else {
 200                 path_to_string(&sub_path)
 201             };
 202             result.push((*span, qualname));
 203             segs = sub_path.segments;
 204         }
 205
 206         result
 207     }
 208
 209     fn write_sub_paths(&mut self, path: &ast::Path) {
 210         let sub_paths = self.process_path_prefixes(path);
 211         for (span, qualname) in sub_paths {
 212             self.dumper.mod_ref(ModRefData {
 213                 span: span,
 214                 qualname: qualname,
 215                 scope: self.cur_scope,
 216                 ref_id: None
 217             }.lower(self.tcx));
 218         }
 219     }
 220
 221     // As write_sub_paths, but does not process the last ident in the path (assuming it
 222     // will be processed elsewhere). See note on write_sub_paths about global.
 223     fn write_sub_paths_truncated(&mut self, path: &ast::Path) {
 224         let sub_paths = self.process_path_prefixes(path);
 225         let len = sub_paths.len();
 226         if len <= 1 {
 227             return;
 228         }
 229
 230         for (span, qualname) in sub_paths.into_iter().take(len - 1) {
 231             self.dumper.mod_ref(ModRefData {
 232                 span: span,
 233                 qualname: qualname,
 234                 scope: self.cur_scope,
 235                 ref_id: None
 236             }.lower(self.tcx));
 237         }
 238     }
 239
 240     // As write_sub_paths, but expects a path of the form module_path::trait::method
 241     // Where trait could actually be a struct too.
 242     fn write_sub_path_trait_truncated(&mut self, path: &ast::Path) {
 243         let sub_paths = self.process_path_prefixes(path);
 244         let len = sub_paths.len();
 245         if len <= 1 {
 246             return;
 247         }
 248         let sub_paths = &sub_paths[.. (len-1)];
 249
 250         // write the trait part of the sub-path
 251         let (ref span, ref qualname) = sub_paths[len-2];
 252         self.dumper.type_ref(TypeRefData {
 253             ref_id: None,
 254             span: *span,
 255             qualname: qualname.to_owned(),
 256             scope: CRATE_NODE_ID
 257         }.lower(self.tcx));
 258
 259         // write the other sub-paths
 260         if len <= 2 {
 261             return;
 262         }
 263         let sub_paths = &sub_paths[..len-2];
 264         for &(ref span, ref qualname) in sub_paths {
 265             self.dumper.mod_ref(ModRefData {
 266                 span: *span,
 267                 qualname: qualname.to_owned(),
 268                 scope: self.cur_scope,
 269                 ref_id: None
 270             }.lower(self.tcx));
 271         }
 272     }
 273
 274     fn lookup_def_id(&self, ref_id: NodeId) -> Option<DefId> {
 275         match self.save_ctxt.get_path_def(ref_id) {
 276             Def::PrimTy(..) | Def::SelfTy(..) | Def::Err => None,
 277             def => Some(def.def_id()),
 278         }
 279     }
 280
 281     fn process_def_kind(&mut self,
 282                         ref_id: NodeId,
 283                         span: Span,
 284                         sub_span: Option<Span>,
 285                         def_id: DefId,
 286                         scope: NodeId) {
 287         if self.span.filter_generated(sub_span, span) {
 288             return;
 289         }
 290
 291         let def = self.save_ctxt.get_path_def(ref_id);
 292         match def {
 293             Def::Mod(_) => {
 294                 self.dumper.mod_ref(ModRefData {
 295                     span: sub_span.expect("No span found for mod ref"),
 296                     ref_id: Some(def_id),
 297                     scope: scope,
 298                     qualname: String::new()
 299                 }.lower(self.tcx));
 300             }
 301             Def::Struct(..) |
 302             Def::Variant(..) |
 303             Def::Union(..) |
 304             Def::Enum(..) |
 305             Def::TyAlias(..) |
 306             Def::Trait(_) => {
 307                 self.dumper.type_ref(TypeRefData {
 308                     span: sub_span.expect("No span found for type ref"),
 309                     ref_id: Some(def_id),
 310                     scope: scope,
 311                     qualname: String::new()
 312                 }.lower(self.tcx));
 313             }
 314             Def::Static(..) |
 315             Def::Const(..) |
 316             Def::StructCtor(..) |
 317             Def::VariantCtor(..) => {
 318                 self.dumper.variable_ref(VariableRefData {
 319                     span: sub_span.expect("No span found for var ref"),
 320                     ref_id: def_id,
 321                     scope: scope,
 322                     name: String::new()
 323                 }.lower(self.tcx));
 324             }
 325             Def::Fn(..) => {
 326                 self.dumper.function_ref(FunctionRefData {
 327                     span: sub_span.expect("No span found for fn ref"),
 328                     ref_id: def_id,
 329                     scope: scope
 330                 }.lower(self.tcx));
 331             }
 332             // With macros 2.0, we can legitimately get a ref to a macro, but
 333             // we don't handle it properly for now (FIXME).
 334             Def::Macro(..) => {}
 335             Def::Local(..) |
 336             Def::Upvar(..) |
 337             Def::SelfTy(..) |
 338             Def::Label(_) |
 339             Def::TyParam(..) |
 340             Def::Method(..) |
 341             Def::AssociatedTy(..) |
 342             Def::AssociatedConst(..) |
 343             Def::PrimTy(_) |
 344             Def::GlobalAsm(_) |
 345             Def::Err => {
 346                span_bug!(span,
 347                          "process_def_kind for unexpected item: {:?}",
 348                          def);
 349             }
 350         }
 351     }
 352
 353     fn process_formals(&mut self, formals: &'l [ast::Arg], qualname: &str) {
 354         for arg in formals {
 355             self.visit_pat(&arg.pat);
 356             let mut collector = PathCollector::new();
 357             collector.visit_pat(&arg.pat);
 358             let span_utils = self.span.clone();
 359             for &(id, ref p, ..) in &collector.collected_paths {
 360                 let typ = match self.save_ctxt.tables.node_types.get(&id) {
 361                     Some(s) => s.to_string(),
 362                     None => continue,
 363                 };
 364                 // get the span only for the name of the variable (I hope the path is only ever a
 365                 // variable name, but who knows?)
 366                 let sub_span = span_utils.span_for_last_ident(p.span);
 367                 if !self.span.filter_generated(sub_span, p.span) {
 368                     self.dumper.variable(VariableData {
 369                         id: id,
 370                         kind: VariableKind::Local,
 371                         span: sub_span.expect("No span found for variable"),
 372                         name: path_to_string(p),
 373                         qualname: format!("{}::{}", qualname, path_to_string(p)),
 374                         type_value: typ,
 375                         value: String::new(),
 376                         scope: CRATE_NODE_ID,
 377                         parent: None,
 378                         visibility: Visibility::Inherited,
 379                         docs: String::new(),
 380                         sig: None,
 381                         attributes: vec![],
 382                     }.lower(self.tcx));
 383                 }
 384             }
 385         }
 386     }
 387
 388     fn process_method(&mut self,
 389                       sig: &'l ast::MethodSig,
 390                       body: Option<&'l ast::Block>,
 391                       id: ast::NodeId,
 392                       name: ast::Name,
 393                       vis: Visibility,
 394                       attrs: &'l [Attribute],
 395                       span: Span) {
 396         debug!("process_method: {}:{}", id, name);
 397
 398         if let Some(method_data) = self.save_ctxt.get_method_data(id, name, span) {
 399
 400             let sig_str = ::make_signature(&sig.decl, &sig.generics);
 401             if body.is_some() {
 402                 self.nest_tables(id, |v| {
 403                     v.process_formals(&sig.decl.inputs, &method_data.qualname)
 404                 });
 405             }
 406
 407             // If the method is defined in an impl, then try and find the corresponding
 408             // method decl in a trait, and if there is one, make a decl_id for it. This
 409             // requires looking up the impl, then the trait, then searching for a method
 410             // with the right name.
 411             if !self.span.filter_generated(Some(method_data.span), span) {
 412                 let container =
 413                     self.tcx.associated_item(self.tcx.hir.local_def_id(id)).container;
 414                 let mut trait_id;
 415                 let mut decl_id = None;
 416                 match container {
 417                     AssociatedItemContainer::ImplContainer(id) => {
 418                         trait_id = self.tcx.trait_id_of_impl(id);
 419
 420                         match trait_id {
 421                             Some(id) => {
 422                                 for item in self.tcx.associated_items(id) {
 423                                     if item.kind == ty::AssociatedKind::Method {
 424                                         if item.name == name {
 425                                             decl_id = Some(item.def_id);
 426                                             break;
 427                                         }
 428                                     }
 429                                 }
 430                             }
 431                             None => {
 432                                 if let Some(NodeItem(item)) = self.tcx.hir.get_if_local(id) {
 433                                     if let hir::ItemImpl(_, _, _, _, ref ty, _) = item.node {
 434                                         trait_id = self.lookup_def_id(ty.id);
 435                                     }
 436                                 }
 437                             }
 438                         }
 439                     }
 440                     AssociatedItemContainer::TraitContainer(id) => {
 441                         trait_id = Some(id);
 442                     }
 443                 }
 444
 445                 self.dumper.method(MethodData {
 446                     id: method_data.id,
 447                     name: method_data.name,
 448                     span: method_data.span,
 449                     scope: method_data.scope,
 450                     qualname: method_data.qualname.clone(),
 451                     value: sig_str,
 452                     decl_id: decl_id,
 453                     parent: trait_id,
 454                     visibility: vis,
 455                     docs: docs_for_attrs(attrs),
 456                     sig: method_data.sig,
 457                     attributes: attrs.to_vec(),
 458                 }.lower(self.tcx));
 459             }
 460
 461             self.process_generic_params(&sig.generics, span, &method_data.qualname, id);
 462         }
 463
 464         // walk arg and return types
 465         for arg in &sig.decl.inputs {
 466             self.visit_ty(&arg.ty);
 467         }
 468
 469         if let ast::FunctionRetTy::Ty(ref ret_ty) = sig.decl.output {
 470             self.visit_ty(ret_ty);
 471         }
 472
 473         // walk the fn body
 474         if let Some(body) = body {
 475             self.nest_tables(id, |v| v.nest_scope(id, |v| v.visit_block(body)));
 476         }
 477     }
 478
 479     fn process_trait_ref(&mut self, trait_ref: &'l ast::TraitRef) {
 480         let trait_ref_data = self.save_ctxt.get_trait_ref_data(trait_ref, self.cur_scope);
 481         if let Some(trait_ref_data) = trait_ref_data {
 482             if !self.span.filter_generated(Some(trait_ref_data.span), trait_ref.path.span) {
 483                 self.dumper.type_ref(trait_ref_data.lower(self.tcx));
 484             }
 485         }
 486         self.process_path(trait_ref.ref_id, &trait_ref.path, Some(recorder::TypeRef));
 487     }
 488
 489     fn process_struct_field_def(&mut self, field: &ast::StructField, parent_id: NodeId) {
 490         let field_data = self.save_ctxt.get_field_data(field, parent_id);
 491         if let Some(mut field_data) = field_data {
 492             if !self.span.filter_generated(Some(field_data.span), field.span) {
 493                 field_data.value = String::new();
 494                 self.dumper.variable(field_data.lower(self.tcx));
 495             }
 496         }
 497     }
 498
 499     // Dump generic params bindings, then visit_generics
 500     fn process_generic_params(&mut self,
 501                               generics: &'l ast::Generics,
 502                               full_span: Span,
 503                               prefix: &str,
 504                               id: NodeId) {
 505         // We can't only use visit_generics since we don't have spans for param
 506         // bindings, so we reparse the full_span to get those sub spans.
 507         // However full span is the entire enum/fn/struct block, so we only want
 508         // the first few to match the number of generics we're looking for.
 509         let param_sub_spans = self.span.spans_for_ty_params(full_span,
 510                                                             (generics.ty_params.len() as isize));
 511         for (param, param_ss) in generics.ty_params.iter().zip(param_sub_spans) {
 512             let name = escape(self.span.snippet(param_ss));
 513             // Append $id to name to make sure each one is unique
 514             let qualname = format!("{}::{}${}",
 515                                    prefix,
 516                                    name,
 517                                    id);
 518             if !self.span.filter_generated(Some(param_ss), full_span) {
 519                 self.dumper.typedef(TypeDefData {
 520                     span: param_ss,
 521                     name: name,
 522                     id: param.id,
 523                     qualname: qualname,
 524                     value: String::new(),
 525                     visibility: Visibility::Inherited,
 526                     parent: None,
 527                     docs: String::new(),
 528                     sig: None,
 529                     attributes: vec![],
 530                 }.lower(self.tcx));
 531             }
 532         }
 533         self.visit_generics(generics);
 534     }
 535
 536     fn process_fn(&mut self,
 537                   item: &'l ast::Item,
 538                   decl: &'l ast::FnDecl,
 539                   ty_params: &'l ast::Generics,
 540                   body: &'l ast::Block) {
 541         if let Some(fn_data) = self.save_ctxt.get_item_data(item) {
 542             down_cast_data!(fn_data, FunctionData, item.span);
 543             if !self.span.filter_generated(Some(fn_data.span), item.span) {
 544                 self.dumper.function(fn_data.clone().lower(self.tcx));
 545             }
 546
 547             self.nest_tables(item.id, |v| v.process_formals(&decl.inputs, &fn_data.qualname));
 548             self.process_generic_params(ty_params, item.span, &fn_data.qualname, item.id);
 549         }
 550
 551         for arg in &decl.inputs {
 552             self.visit_ty(&arg.ty);
 553         }
 554
 555         if let ast::FunctionRetTy::Ty(ref ret_ty) = decl.output {
 556             self.visit_ty(&ret_ty);
 557         }
 558
 559         self.nest_tables(item.id, |v| v.nest_scope(item.id, |v| v.visit_block(&body)));
 560     }
 561
 562     fn process_static_or_const_item(&mut self,
 563                                     item: &'l ast::Item,
 564                                     typ: &'l ast::Ty,
 565                                     expr: &'l ast::Expr) {
 566         if let Some(var_data) = self.save_ctxt.get_item_data(item) {
 567             down_cast_data!(var_data, VariableData, item.span);
 568             if !self.span.filter_generated(Some(var_data.span), item.span) {
 569                 self.dumper.variable(var_data.lower(self.tcx));
 570             }
 571         }
 572         self.visit_ty(&typ);
 573         self.visit_expr(expr);
 574     }
 575
 576     fn process_assoc_const(&mut self,
 577                            id: ast::NodeId,
 578                            name: ast::Name,
 579                            span: Span,
 580                            typ: &'l ast::Ty,
 581                            expr: &'l ast::Expr,
 582                            parent_id: DefId,
 583                            vis: Visibility,
 584                            attrs: &'l [Attribute]) {
 585         let qualname = format!("::{}", self.tcx.node_path_str(id));
 586
 587         let sub_span = self.span.sub_span_after_keyword(span, keywords::Const);
 588
 589         if !self.span.filter_generated(sub_span, span) {
 590             self.dumper.variable(VariableData {
 591                 span: sub_span.expect("No span found for variable"),
 592                 kind: VariableKind::Const,
 593                 id: id,
 594                 name: name.to_string(),
 595                 qualname: qualname,
 596                 value: self.span.snippet(expr.span),
 597                 type_value: ty_to_string(&typ),
 598                 scope: self.cur_scope,
 599                 parent: Some(parent_id),
 600                 visibility: vis,
 601                 docs: docs_for_attrs(attrs),
 602                 sig: None,
 603                 attributes: attrs.to_vec(),
 604             }.lower(self.tcx));
 605         }
 606
 607         // walk type and init value
 608         self.visit_ty(typ);
 609         self.visit_expr(expr);
 610     }
 611
 612     // FIXME tuple structs should generate tuple-specific data.
 613     fn process_struct(&mut self,
 614                       item: &'l ast::Item,
 615                       def: &'l ast::VariantData,
 616                       ty_params: &'l ast::Generics) {
 617         let name = item.ident.to_string();
 618         let qualname = format!("::{}", self.tcx.node_path_str(item.id));
 619
 620         let sub_span = self.span.sub_span_after_keyword(item.span, keywords::Struct);
 621         let (val, fields) =
 622             if let ast::ItemKind::Struct(ast::VariantData::Struct(ref fields, _), _) = item.node
 623         {
 624             let fields_str = fields.iter()
 625                                    .enumerate()
 626                                    .map(|(i, f)| f.ident.map(|i| i.to_string())
 627                                                   .unwrap_or(i.to_string()))
 628                                    .collect::<Vec<_>>()
 629                                    .join(", ");
 630             (format!("{} {{ {} }}", name, fields_str), fields.iter().map(|f| f.id).collect())
 631         } else {
 632             (String::new(), vec![])
 633         };
 634
 635         if !self.span.filter_generated(sub_span, item.span) {
 636             self.dumper.struct_data(StructData {
 637                 span: sub_span.expect("No span found for struct"),
 638                 id: item.id,
 639                 name: name,
 640                 ctor_id: def.id(),
 641                 qualname: qualname.clone(),
 642                 scope: self.cur_scope,
 643                 value: val,
 644                 fields: fields,
 645                 visibility: From::from(&item.vis),
 646                 docs: docs_for_attrs(&item.attrs),
 647                 sig: self.save_ctxt.sig_base(item),
 648                 attributes: item.attrs.clone(),
 649             }.lower(self.tcx));
 650         }
 651
 652         for field in def.fields() {
 653             self.process_struct_field_def(field, item.id);
 654             self.visit_ty(&field.ty);
 655         }
 656
 657         self.process_generic_params(ty_params, item.span, &qualname, item.id);
 658     }
 659
 660     fn process_enum(&mut self,
 661                     item: &'l ast::Item,
 662                     enum_definition: &'l ast::EnumDef,
 663                     ty_params: &'l ast::Generics) {
 664         let enum_data = self.save_ctxt.get_item_data(item);
 665         let enum_data = match enum_data {
 666             None => return,
 667             Some(data) => data,
 668         };
 669         down_cast_data!(enum_data, EnumData, item.span);
 670         if !self.span.filter_generated(Some(enum_data.span), item.span) {
 671             self.dumper.enum_data(enum_data.clone().lower(self.tcx));
 672         }
 673
 674         for variant in &enum_definition.variants {
 675             let name = variant.node.name.name.to_string();
 676             let mut qualname = enum_data.qualname.clone();
 677             qualname.push_str("::");
 678             qualname.push_str(&name);
 679
 680             let text = self.span.signature_string_for_span(variant.span);
 681             let ident_start = text.find(&name).unwrap();
 682             let ident_end = ident_start + name.len();
 683             let sig = Signature {
 684                 span: variant.span,
 685                 text: text,
 686                 ident_start: ident_start,
 687                 ident_end: ident_end,
 688                 defs: vec![],
 689                 refs: vec![],
 690             };
 691
 692             match variant.node.data {
 693                 ast::VariantData::Struct(ref fields, _) => {
 694                     let sub_span = self.span.span_for_first_ident(variant.span);
 695                     let fields_str = fields.iter()
 696                                            .enumerate()
 697                                            .map(|(i, f)| f.ident.map(|i| i.to_string())
 698                                                           .unwrap_or(i.to_string()))
 699                                            .collect::<Vec<_>>()
 700                                            .join(", ");
 701                     let val = format!("{}::{} {{ {} }}", enum_data.name, name, fields_str);
 702                     if !self.span.filter_generated(sub_span, variant.span) {
 703                         self.dumper.struct_variant(StructVariantData {
 704                             span: sub_span.expect("No span found for struct variant"),
 705                             id: variant.node.data.id(),
 706                             name: name,
 707                             qualname: qualname,
 708                             type_value: enum_data.qualname.clone(),
 709                             value: val,
 710                             scope: enum_data.scope,
 711                             parent: Some(make_def_id(item.id, &self.tcx.hir)),
 712                             docs: docs_for_attrs(&variant.node.attrs),
 713                             sig: sig,
 714                             attributes: variant.node.attrs.clone(),
 715                         }.lower(self.tcx));
 716                     }
 717                 }
 718                 ref v => {
 719                     let sub_span = self.span.span_for_first_ident(variant.span);
 720                     let mut val = format!("{}::{}", enum_data.name, name);
 721                     if let &ast::VariantData::Tuple(ref fields, _) = v {
 722                         val.push('(');
 723                         val.push_str(&fields.iter()
 724                                             .map(|f| ty_to_string(&f.ty))
 725                                             .collect::<Vec<_>>()
 726                                             .join(", "));
 727                         val.push(')');
 728                     }
 729                     if !self.span.filter_generated(sub_span, variant.span) {
 730                         self.dumper.tuple_variant(TupleVariantData {
 731                             span: sub_span.expect("No span found for tuple variant"),
 732                             id: variant.node.data.id(),
 733                             name: name,
 734                             qualname: qualname,
 735                             type_value: enum_data.qualname.clone(),
 736                             value: val,
 737                             scope: enum_data.scope,
 738                             parent: Some(make_def_id(item.id, &self.tcx.hir)),
 739                             docs: docs_for_attrs(&variant.node.attrs),
 740                             sig: sig,
 741                             attributes: variant.node.attrs.clone(),
 742                         }.lower(self.tcx));
 743                     }
 744                 }
 745             }
 746
 747
 748             for field in variant.node.data.fields() {
 749                 self.process_struct_field_def(field, variant.node.data.id());
 750                 self.visit_ty(&field.ty);
 751             }
 752         }
 753         self.process_generic_params(ty_params, item.span, &enum_data.qualname, enum_data.id);
 754     }
 755
 756     fn process_impl(&mut self,
 757                     item: &'l ast::Item,
 758                     type_parameters: &'l ast::Generics,
 759                     trait_ref: &'l Option<ast::TraitRef>,
 760                     typ: &'l ast::Ty,
 761                     impl_items: &'l [ast::ImplItem]) {
 762         if let Some(impl_data) = self.save_ctxt.get_item_data(item) {
 763             down_cast_data!(impl_data, ImplData, item.span);
 764             if !self.span.filter_generated(Some(impl_data.span), item.span) {
 765                 self.dumper.impl_data(ImplData {
 766                     id: impl_data.id,
 767                     span: impl_data.span,
 768                     scope: impl_data.scope,
 769                     trait_ref: impl_data.trait_ref.map(|d| d.ref_id.unwrap()),
 770                     self_ref: impl_data.self_ref.map(|d| d.ref_id.unwrap())
 771                 }.lower(self.tcx));
 772             }
 773         }
 774         self.visit_ty(&typ);
 775         if let &Some(ref trait_ref) = trait_ref {
 776             self.process_path(trait_ref.ref_id, &trait_ref.path, Some(recorder::TypeRef));
 777         }
 778         self.process_generic_params(type_parameters, item.span, "", item.id);
 779         for impl_item in impl_items {
 780             let map = &self.tcx.hir;
 781             self.process_impl_item(impl_item, make_def_id(item.id, map));
 782         }
 783     }
 784
 785     fn process_trait(&mut self,
 786                      item: &'l ast::Item,
 787                      generics: &'l ast::Generics,
 788                      trait_refs: &'l ast::TyParamBounds,
 789                      methods: &'l [ast::TraitItem]) {
 790         let name = item.ident.to_string();
 791         let qualname = format!("::{}", self.tcx.node_path_str(item.id));
 792         let mut val = name.clone();
 793         if !generics.lifetimes.is_empty() || !generics.ty_params.is_empty() {
 794             val.push_str(&generics_to_string(generics));
 795         }
 796         if !trait_refs.is_empty() {
 797             val.push_str(": ");
 798             val.push_str(&bounds_to_string(trait_refs));
 799         }
 800         let sub_span = self.span.sub_span_after_keyword(item.span, keywords::Trait);
 801         if !self.span.filter_generated(sub_span, item.span) {
 802             self.dumper.trait_data(TraitData {
 803                 span: sub_span.expect("No span found for trait"),
 804                 id: item.id,
 805                 name: name,
 806                 qualname: qualname.clone(),
 807                 scope: self.cur_scope,
 808                 value: val,
 809                 items: methods.iter().map(|i| i.id).collect(),
 810                 visibility: From::from(&item.vis),
 811                 docs: docs_for_attrs(&item.attrs),
 812                 sig: self.save_ctxt.sig_base(item),
 813                 attributes: item.attrs.clone(),
 814             }.lower(self.tcx));
 815         }
 816
 817         // super-traits
 818         for super_bound in trait_refs.iter() {
 819             let trait_ref = match *super_bound {
 820                 ast::TraitTyParamBound(ref trait_ref, _) => {
 821                     trait_ref
 822                 }
 823                 ast::RegionTyParamBound(..) => {
 824                     continue;
 825                 }
 826             };
 827
 828             let trait_ref = &trait_ref.trait_ref;
 829             if let Some(id) = self.lookup_def_id(trait_ref.ref_id) {
 830                 let sub_span = self.span.sub_span_for_type_name(trait_ref.path.span);
 831                 if !self.span.filter_generated(sub_span, trait_ref.path.span) {
 832                     self.dumper.type_ref(TypeRefData {
 833                         span: sub_span.expect("No span found for trait ref"),
 834                         ref_id: Some(id),
 835                         scope: self.cur_scope,
 836                         qualname: String::new()
 837                     }.lower(self.tcx));
 838                 }
 839
 840                 if !self.span.filter_generated(sub_span, trait_ref.path.span) {
 841                     let sub_span = sub_span.expect("No span for inheritance");
 842                     self.dumper.inheritance(InheritanceData {
 843                         span: sub_span,
 844                         base_id: id,
 845                         deriv_id: item.id
 846                     }.lower(self.tcx));
 847                 }
 848             }
 849         }
 850
 851         // walk generics and methods
 852         self.process_generic_params(generics, item.span, &qualname, item.id);
 853         for method in methods {
 854             let map = &self.tcx.hir;
 855             self.process_trait_item(method, make_def_id(item.id, map))
 856         }
 857     }
 858
 859     // `item` is the module in question, represented as an item.
 860     fn process_mod(&mut self, item: &ast::Item) {
 861         if let Some(mod_data) = self.save_ctxt.get_item_data(item) {
 862             down_cast_data!(mod_data, ModData, item.span);
 863             if !self.span.filter_generated(Some(mod_data.span), item.span) {
 864                 self.dumper.mod_data(mod_data.lower(self.tcx));
 865             }
 866         }
 867     }
 868
 869     fn process_path(&mut self, id: NodeId, path: &ast::Path, ref_kind: Option<recorder::Row>) {
 870         let path_data = self.save_ctxt.get_path_data(id, path);
 871         if generated_code(path.span) && path_data.is_none() {
 872             return;
 873         }
 874
 875         let path_data = match path_data {
 876             Some(pd) => pd,
 877             None => {
 878                 return;
 879             }
 880         };
 881
 882         match path_data {
 883             Data::VariableRefData(vrd) => {
 884                 // FIXME: this whole block duplicates the code in process_def_kind
 885                 if !self.span.filter_generated(Some(vrd.span), path.span) {
 886                     match ref_kind {
 887                         Some(recorder::TypeRef) => {
 888                             self.dumper.type_ref(TypeRefData {
 889                                 span: vrd.span,
 890                                 ref_id: Some(vrd.ref_id),
 891                                 scope: vrd.scope,
 892                                 qualname: String::new()
 893                             }.lower(self.tcx));
 894                         }
 895                         Some(recorder::FnRef) => {
 896                             self.dumper.function_ref(FunctionRefData {
 897                                 span: vrd.span,
 898                                 ref_id: vrd.ref_id,
 899                                 scope: vrd.scope
 900                             }.lower(self.tcx));
 901                         }
 902                         Some(recorder::ModRef) => {
 903                             self.dumper.mod_ref( ModRefData {
 904                                 span: vrd.span,
 905                                 ref_id: Some(vrd.ref_id),
 906                                 scope: vrd.scope,
 907                                 qualname: String::new()
 908                             }.lower(self.tcx));
 909                         }
 910                         Some(recorder::VarRef) | None
 911                             => self.dumper.variable_ref(vrd.lower(self.tcx))
 912                     }
 913                 }
 914
 915             }
 916             Data::TypeRefData(trd) => {
 917                 if !self.span.filter_generated(Some(trd.span), path.span) {
 918                     self.dumper.type_ref(trd.lower(self.tcx));
 919                 }
 920             }
 921             Data::MethodCallData(mcd) => {
 922                 if !self.span.filter_generated(Some(mcd.span), path.span) {
 923                     self.dumper.method_call(mcd.lower(self.tcx));
 924                 }
 925             }
 926             Data::FunctionCallData(fcd) => {
 927                 if !self.span.filter_generated(Some(fcd.span), path.span) {
 928                     self.dumper.function_call(fcd.lower(self.tcx));
 929                 }
 930             }
 931             _ => {
 932                span_bug!(path.span, "Unexpected data: {:?}", path_data);
 933             }
 934         }
 935
 936         // Modules or types in the path prefix.
 937         match self.save_ctxt.get_path_def(id) {
 938             Def::Method(did) => {
 939                 let ti = self.tcx.associated_item(did);
 940                 if ti.kind == ty::AssociatedKind::Method && ti.method_has_self_argument {
 941                     self.write_sub_path_trait_truncated(path);
 942                 }
 943             }
 944             Def::Fn(..) |
 945             Def::Const(..) |
 946             Def::Static(..) |
 947             Def::StructCtor(..) |
 948             Def::VariantCtor(..) |
 949             Def::AssociatedConst(..) |
 950             Def::Local(..) |
 951             Def::Upvar(..) |
 952             Def::Struct(..) |
 953             Def::Union(..) |
 954             Def::Variant(..) |
 955             Def::TyAlias(..) |
 956             Def::AssociatedTy(..) => self.write_sub_paths_truncated(path),
 957             _ => {}
 958         }
 959     }
 960
 961     fn process_struct_lit(&mut self,
 962                           ex: &'l ast::Expr,
 963                           path: &'l ast::Path,
 964                           fields: &'l [ast::Field],
 965                           variant: &'l ty::VariantDef,
 966                           base: &'l Option<P<ast::Expr>>) {
 967         self.write_sub_paths_truncated(path);
 968
 969         if let Some(struct_lit_data) = self.save_ctxt.get_expr_data(ex) {
 970             down_cast_data!(struct_lit_data, TypeRefData, ex.span);
 971             if !self.span.filter_generated(Some(struct_lit_data.span), ex.span) {
 972                 self.dumper.type_ref(struct_lit_data.lower(self.tcx));
 973             }
 974
 975             let scope = self.save_ctxt.enclosing_scope(ex.id);
 976
 977             for field in fields {
 978                 if let Some(field_data) = self.save_ctxt
 979                                               .get_field_ref_data(field, variant, scope) {
 980
 981                     if !self.span.filter_generated(Some(field_data.span), field.ident.span) {
 982                         self.dumper.variable_ref(field_data.lower(self.tcx));
 983                     }
 984                 }
 985
 986                 self.visit_expr(&field.expr)
 987             }
 988         }
 989
 990         walk_list!(self, visit_expr, base);
 991     }
 992
 993     fn process_method_call(&mut self, ex: &'l ast::Expr, args: &'l [P<ast::Expr>]) {
 994         if let Some(mcd) = self.save_ctxt.get_expr_data(ex) {
 995             down_cast_data!(mcd, MethodCallData, ex.span);
 996             if !self.span.filter_generated(Some(mcd.span), ex.span) {
 997                 self.dumper.method_call(mcd.lower(self.tcx));
 998             }
 999         }
1000
1001         // walk receiver and args
1002         walk_list!(self, visit_expr, args);
1003     }
1004
1005     fn process_pat(&mut self, p: &'l ast::Pat) {
1006         match p.node {
1007             PatKind::Struct(ref _path, ref fields, _) => {
1008                 // FIXME do something with _path?
1009                 let adt = match self.save_ctxt.tables.node_id_to_type_opt(p.id) {
1010                     Some(ty) => ty.ty_adt_def().unwrap(),
1011                     None => {
1012                         visit::walk_pat(self, p);
1013                         return;
1014                     }
1015                 };
1016                 let variant = adt.variant_of_def(self.save_ctxt.get_path_def(p.id));
1017
1018                 for &Spanned { node: ref field, span } in fields {
1019                     let sub_span = self.span.span_for_first_ident(span);
1020                     if let Some(f) = variant.find_field_named(field.ident.name) {
1021                         if !self.span.filter_generated(sub_span, span) {
1022                             self.dumper.variable_ref(VariableRefData {
1023                                 span: sub_span.expect("No span fund for var ref"),
1024                                 ref_id: f.did,
1025                                 scope: self.cur_scope,
1026                                 name: String::new()
1027                             }.lower(self.tcx));
1028                         }
1029                     }
1030                     self.visit_pat(&field.pat);
1031                 }
1032             }
1033             _ => visit::walk_pat(self, p),
1034         }
1035     }
1036
1037
1038     fn process_var_decl(&mut self, p: &'l ast::Pat, value: String) {
1039         // The local could declare multiple new vars, we must walk the
1040         // pattern and collect them all.
1041         let mut collector = PathCollector::new();
1042         collector.visit_pat(&p);
1043         self.visit_pat(&p);
1044
1045         for &(id, ref p, immut, _) in &collector.collected_paths {
1046             let mut value = match immut {
1047                 ast::Mutability::Immutable => value.to_string(),
1048                 _ => String::new(),
1049             };
1050             let typ = match self.save_ctxt.tables.node_types.get(&id) {
1051                 Some(typ) => {
1052                     let typ = typ.to_string();
1053                     if !value.is_empty() {
1054                         value.push_str(": ");
1055                     }
1056                     value.push_str(&typ);
1057                     typ
1058                 }
1059                 None => String::new(),
1060             };
1061
1062             // Get the span only for the name of the variable (I hope the path
1063             // is only ever a variable name, but who knows?).
1064             let sub_span = self.span.span_for_last_ident(p.span);
1065             // Rust uses the id of the pattern for var lookups, so we'll use it too.
1066             if !self.span.filter_generated(sub_span, p.span) {
1067                 self.dumper.variable(VariableData {
1068                     span: sub_span.expect("No span found for variable"),
1069                     kind: VariableKind::Local,
1070                     id: id,
1071                     name: path_to_string(p),
1072                     qualname: format!("{}${}", path_to_string(p), id),
1073                     value: value,
1074                     type_value: typ,
1075                     scope: CRATE_NODE_ID,
1076                     parent: None,
1077                     visibility: Visibility::Inherited,
1078                     docs: String::new(),
1079                     sig: None,
1080                     attributes: vec![],
1081                 }.lower(self.tcx));
1082             }
1083         }
1084     }
1085
1086     /// Extract macro use and definition information from the AST node defined
1087     /// by the given NodeId, using the expansion information from the node's
1088     /// span.
1089     ///
1090     /// If the span is not macro-generated, do nothing, else use callee and
1091     /// callsite spans to record macro definition and use data, using the
1092     /// mac_uses and mac_defs sets to prevent multiples.
1093     fn process_macro_use(&mut self, span: Span, id: NodeId) {
1094         let data = match self.save_ctxt.get_macro_use_data(span, id) {
1095             None => return,
1096             Some(data) => data,
1097         };
1098         let mut hasher = DefaultHasher::new();
1099         data.callee_span.hash(&mut hasher);
1100         let hash = hasher.finish();
1101         let qualname = format!("{}::{}", data.name, hash);
1102         // Don't write macro definition for imported macros
1103         if !self.mac_defs.contains(&data.callee_span)
1104             && !data.imported {
1105             self.mac_defs.insert(data.callee_span);
1106             if let Some(sub_span) = self.span.span_for_macro_def_name(data.callee_span) {
1107                 self.dumper.macro_data(MacroData {
1108                     span: sub_span,
1109                     name: data.name.clone(),
1110                     qualname: qualname.clone(),
1111                     // FIXME where do macro docs come from?
1112                     docs: String::new(),
1113                 }.lower(self.tcx));
1114             }
1115         }
1116         if !self.mac_uses.contains(&data.span) {
1117             self.mac_uses.insert(data.span);
1118             if let Some(sub_span) = self.span.span_for_macro_use_name(data.span) {
1119                 self.dumper.macro_use(MacroUseData {
1120                     span: sub_span,
1121                     name: data.name,
1122                     qualname: qualname,
1123                     scope: data.scope,
1124                     callee_span: data.callee_span,
1125                     imported: data.imported,
1126                 }.lower(self.tcx));
1127             }
1128         }
1129     }
1130
1131     fn process_trait_item(&mut self, trait_item: &'l ast::TraitItem, trait_id: DefId) {
1132         self.process_macro_use(trait_item.span, trait_item.id);
1133         match trait_item.node {
1134             ast::TraitItemKind::Const(ref ty, Some(ref expr)) => {
1135                 self.process_assoc_const(trait_item.id,
1136                                          trait_item.ident.name,
1137                                          trait_item.span,
1138                                          &ty,
1139                                          &expr,
1140                                          trait_id,
1141                                          Visibility::Public,
1142                                          &trait_item.attrs);
1143             }
1144             ast::TraitItemKind::Method(ref sig, ref body) => {
1145                 self.process_method(sig,
1146                                     body.as_ref().map(|x| &**x),
1147                                     trait_item.id,
1148                                     trait_item.ident.name,
1149                                     Visibility::Public,
1150                                     &trait_item.attrs,
1151                                     trait_item.span);
1152             }
1153             ast::TraitItemKind::Type(ref _bounds, ref default_ty) => {
1154                 // FIXME do something with _bounds (for type refs)
1155                 let name = trait_item.ident.name.to_string();
1156                 let qualname = format!("::{}", self.tcx.node_path_str(trait_item.id));
1157                 let sub_span = self.span.sub_span_after_keyword(trait_item.span, keywords::Type);
1158
1159                 if !self.span.filter_generated(sub_span, trait_item.span) {
1160                     self.dumper.typedef(TypeDefData {
1161                         span: sub_span.expect("No span found for assoc type"),
1162                         name: name,
1163                         id: trait_item.id,
1164                         qualname: qualname,
1165                         value: self.span.snippet(trait_item.span),
1166                         visibility: Visibility::Public,
1167                         parent: Some(trait_id),
1168                         docs: docs_for_attrs(&trait_item.attrs),
1169                         sig: None,
1170                         attributes: trait_item.attrs.clone(),
1171                     }.lower(self.tcx));
1172                 }
1173
1174                 if let &Some(ref default_ty) = default_ty {
1175                     self.visit_ty(default_ty)
1176                 }
1177             }
1178             ast::TraitItemKind::Const(ref ty, None) => self.visit_ty(ty),
1179             ast::TraitItemKind::Macro(_) => {}
1180         }
1181     }
1182
1183     fn process_impl_item(&mut self, impl_item: &'l ast::ImplItem, impl_id: DefId) {
1184         self.process_macro_use(impl_item.span, impl_item.id);
1185         match impl_item.node {
1186             ast::ImplItemKind::Const(ref ty, ref expr) => {
1187                 self.process_assoc_const(impl_item.id,
1188                                          impl_item.ident.name,
1189                                          impl_item.span,
1190                                          &ty,
1191                                          &expr,
1192                                          impl_id,
1193                                          From::from(&impl_item.vis),
1194                                          &impl_item.attrs);
1195             }
1196             ast::ImplItemKind::Method(ref sig, ref body) => {
1197                 self.process_method(sig,
1198                                     Some(body),
1199                                     impl_item.id,
1200                                     impl_item.ident.name,
1201                                     From::from(&impl_item.vis),
1202                                     &impl_item.attrs,
1203                                     impl_item.span);
1204             }
1205             ast::ImplItemKind::Type(ref ty) => self.visit_ty(ty),
1206             ast::ImplItemKind::Macro(_) => {}
1207         }
1208     }
1209 }
1210
1211 impl<'l, 'tcx: 'l, 'll, D: Dump +'ll> Visitor<'l> for DumpVisitor<'l, 'tcx, 'll, D> {
1212     fn visit_item(&mut self, item: &'l ast::Item) {
1213         use syntax::ast::ItemKind::*;
1214         self.process_macro_use(item.span, item.id);
1215         match item.node {
1216             Use(ref use_item) => {
1217                 match use_item.node {
1218                     ast::ViewPathSimple(ident, ref path) => {
1219                         let sub_span = self.span.span_for_last_ident(path.span);
1220                         let mod_id = match self.lookup_def_id(item.id) {
1221                             Some(def_id) => {
1222                                 let scope = self.cur_scope;
1223                                 self.process_def_kind(item.id, path.span, sub_span, def_id, scope);
1224
1225                                 Some(def_id)
1226                             }
1227                             None => None,
1228                         };
1229
1230                         // 'use' always introduces an alias, if there is not an explicit
1231                         // one, there is an implicit one.
1232                         let sub_span = match self.span.sub_span_after_keyword(use_item.span,
1233                                                                               keywords::As) {
1234                             Some(sub_span) => Some(sub_span),
1235                             None => sub_span,
1236                         };
1237
1238                         if !self.span.filter_generated(sub_span, path.span) {
1239                             self.dumper.use_data(UseData {
1240                                 span: sub_span.expect("No span found for use"),
1241                                 id: item.id,
1242                                 mod_id: mod_id,
1243                                 name: ident.to_string(),
1244                                 scope: self.cur_scope,
1245                                 visibility: From::from(&item.vis),
1246                             }.lower(self.tcx));
1247                         }
1248                         self.write_sub_paths_truncated(path);
1249                     }
1250                     ast::ViewPathGlob(ref path) => {
1251                         // Make a comma-separated list of names of imported modules.
1252                         let mut names = vec![];
1253                         let glob_map = &self.save_ctxt.analysis.glob_map;
1254                         let glob_map = glob_map.as_ref().unwrap();
1255                         if glob_map.contains_key(&item.id) {
1256                             for n in glob_map.get(&item.id).unwrap() {
1257                                 names.push(n.to_string());
1258                             }
1259                         }
1260
1261                         let sub_span = self.span
1262                                            .sub_span_of_token(item.span, token::BinOp(token::Star));
1263                         if !self.span.filter_generated(sub_span, item.span) {
1264                             self.dumper.use_glob(UseGlobData {
1265                                 span: sub_span.expect("No span found for use glob"),
1266                                 id: item.id,
1267                                 names: names,
1268                                 scope: self.cur_scope,
1269                                 visibility: From::from(&item.vis),
1270                             }.lower(self.tcx));
1271                         }
1272                         self.write_sub_paths(path);
1273                     }
1274                     ast::ViewPathList(ref path, ref list) => {
1275                         for plid in list {
1276                             let scope = self.cur_scope;
1277                             let id = plid.node.id;
1278                             if let Some(def_id) = self.lookup_def_id(id) {
1279                                 let span = plid.span;
1280                                 self.process_def_kind(id, span, Some(span), def_id, scope);
1281                             }
1282                         }
1283
1284                         self.write_sub_paths(path);
1285                     }
1286                 }
1287             }
1288             ExternCrate(ref s) => {
1289                 let location = match *s {
1290                     Some(s) => s.to_string(),
1291                     None => item.ident.to_string(),
1292                 };
1293                 let alias_span = self.span.span_for_last_ident(item.span);
1294                 let cnum = match self.sess.cstore.extern_mod_stmt_cnum(item.id) {
1295                     Some(cnum) => cnum,
1296                     None => LOCAL_CRATE,
1297                 };
1298
1299                 if !self.span.filter_generated(alias_span, item.span) {
1300                     self.dumper.extern_crate(ExternCrateData {
1301                         id: item.id,
1302                         name: item.ident.to_string(),
1303                         crate_num: cnum,
1304                         location: location,
1305                         span: alias_span.expect("No span found for extern crate"),
1306                         scope: self.cur_scope,
1307                     }.lower(self.tcx));
1308                 }
1309             }
1310             Fn(ref decl, .., ref ty_params, ref body) =>
1311                 self.process_fn(item, &decl, ty_params, &body),
1312             Static(ref typ, _, ref expr) =>
1313                 self.process_static_or_const_item(item, typ, expr),
1314             Const(ref typ, ref expr) =>
1315                 self.process_static_or_const_item(item, &typ, &expr),
1316             Struct(ref def, ref ty_params) => self.process_struct(item, def, ty_params),
1317             Enum(ref def, ref ty_params) => self.process_enum(item, def, ty_params),
1318             Impl(..,
1319                  ref ty_params,
1320                  ref trait_ref,
1321                  ref typ,
1322                  ref impl_items) => {
1323                 self.process_impl(item, ty_params, trait_ref, &typ, impl_items)
1324             }
1325             Trait(_, ref generics, ref trait_refs, ref methods) =>
1326                 self.process_trait(item, generics, trait_refs, methods),
1327             Mod(ref m) => {
1328                 self.process_mod(item);
1329                 self.nest_scope(item.id, |v| visit::walk_mod(v, m));
1330             }
1331             Ty(ref ty, ref ty_params) => {
1332                 let qualname = format!("::{}", self.tcx.node_path_str(item.id));
1333                 let value = ty_to_string(&ty);
1334                 let sub_span = self.span.sub_span_after_keyword(item.span, keywords::Type);
1335                 if !self.span.filter_generated(sub_span, item.span) {
1336                     self.dumper.typedef(TypeDefData {
1337                         span: sub_span.expect("No span found for typedef"),
1338                         name: item.ident.to_string(),
1339                         id: item.id,
1340                         qualname: qualname.clone(),
1341                         value: value,
1342                         visibility: From::from(&item.vis),
1343                         parent: None,
1344                         docs: docs_for_attrs(&item.attrs),
1345                         sig: Some(self.save_ctxt.sig_base(item)),
1346                         attributes: item.attrs.clone(),
1347                     }.lower(self.tcx));
1348                 }
1349
1350                 self.visit_ty(&ty);
1351                 self.process_generic_params(ty_params, item.span, &qualname, item.id);
1352             }
1353             Mac(_) => (),
1354             _ => visit::walk_item(self, item),
1355         }
1356     }
1357
1358     fn visit_generics(&mut self, generics: &'l ast::Generics) {
1359         for param in generics.ty_params.iter() {
1360             for bound in param.bounds.iter() {
1361                 if let ast::TraitTyParamBound(ref trait_ref, _) = *bound {
1362                     self.process_trait_ref(&trait_ref.trait_ref);
1363                 }
1364             }
1365             if let Some(ref ty) = param.default {
1366                 self.visit_ty(&ty);
1367             }
1368         }
1369     }
1370
1371     fn visit_ty(&mut self, t: &'l ast::Ty) {
1372         self.process_macro_use(t.span, t.id);
1373         match t.node {
1374             ast::TyKind::Path(_, ref path) => {
1375                 if generated_code(t.span) {
1376                     return;
1377                 }
1378
1379                 if let Some(id) = self.lookup_def_id(t.id) {
1380                     if let Some(sub_span) = self.span.sub_span_for_type_name(t.span) {
1381                         self.dumper.type_ref(TypeRefData {
1382                             span: sub_span,
1383                             ref_id: Some(id),
1384                             scope: self.cur_scope,
1385                             qualname: String::new()
1386                         }.lower(self.tcx));
1387                     }
1388                 }
1389
1390                 self.write_sub_paths_truncated(path);
1391                 visit::walk_path(self, path);
1392             }
1393             ast::TyKind::Array(ref element, ref length) => {
1394                 self.visit_ty(element);
1395                 self.nest_tables(length.id, |v| v.visit_expr(length));
1396             }
1397             _ => visit::walk_ty(self, t),
1398         }
1399     }
1400
1401     fn visit_expr(&mut self, ex: &'l ast::Expr) {
1402         debug!("visit_expr {:?}", ex.node);
1403         self.process_macro_use(ex.span, ex.id);
1404         match ex.node {
1405             ast::ExprKind::Struct(ref path, ref fields, ref base) => {
1406                 let hir_expr = self.save_ctxt.tcx.hir.expect_expr(ex.id);
1407                 let adt = match self.save_ctxt.tables.expr_ty_opt(&hir_expr) {
1408                     Some(ty) => ty.ty_adt_def().unwrap(),
1409                     None => {
1410                         visit::walk_expr(self, ex);
1411                         return;
1412                     }
1413                 };
1414                 let def = self.save_ctxt.get_path_def(hir_expr.id);
1415                 self.process_struct_lit(ex, path, fields, adt.variant_of_def(def), base)
1416             }
1417             ast::ExprKind::MethodCall(.., ref args) => self.process_method_call(ex, args),
1418             ast::ExprKind::Field(ref sub_ex, _) => {
1419                 self.visit_expr(&sub_ex);
1420
1421                 if let Some(field_data) = self.save_ctxt.get_expr_data(ex) {
1422                     down_cast_data!(field_data, VariableRefData, ex.span);
1423                     if !self.span.filter_generated(Some(field_data.span), ex.span) {
1424                         self.dumper.variable_ref(field_data.lower(self.tcx));
1425                     }
1426                 }
1427             }
1428             ast::ExprKind::TupField(ref sub_ex, idx) => {
1429                 self.visit_expr(&sub_ex);
1430
1431                 let hir_node = match self.save_ctxt.tcx.hir.find(sub_ex.id) {
1432                     Some(Node::NodeExpr(expr)) => expr,
1433                     _ => {
1434                         debug!("Missing or weird node for sub-expression {} in {:?}",
1435                                sub_ex.id, ex);
1436                         return;
1437                     }
1438                 };
1439                 let ty = match self.save_ctxt.tables.expr_ty_adjusted_opt(&hir_node) {
1440                     Some(ty) => &ty.sty,
1441                     None => {
1442                         visit::walk_expr(self, ex);
1443                         return;
1444                     }
1445                 };
1446                 match *ty {
1447                     ty::TyAdt(def, _) => {
1448                         let sub_span = self.span.sub_span_after_token(ex.span, token::Dot);
1449                         if !self.span.filter_generated(sub_span, ex.span) {
1450                             self.dumper.variable_ref(VariableRefData {
1451                                 span: sub_span.expect("No span found for var ref"),
1452                                 ref_id: def.struct_variant().fields[idx.node].did,
1453                                 scope: self.cur_scope,
1454                                 name: String::new()
1455                             }.lower(self.tcx));
1456                         }
1457                     }
1458                     ty::TyTuple(..) => {}
1459                     _ => span_bug!(ex.span,
1460                                    "Expected struct or tuple type, found {:?}",
1461                                    ty),
1462                 }
1463             }
1464             ast::ExprKind::Closure(_, ref decl, ref body, _fn_decl_span) => {
1465                 let mut id = String::from("$");
1466                 id.push_str(&ex.id.to_string());
1467
1468                 // walk arg and return types
1469                 for arg in &decl.inputs {
1470                     self.visit_ty(&arg.ty);
1471                 }
1472
1473                 if let ast::FunctionRetTy::Ty(ref ret_ty) = decl.output {
1474                     self.visit_ty(&ret_ty);
1475                 }
1476
1477                 // walk the body
1478                 self.nest_tables(ex.id, |v| {
1479                     v.process_formals(&decl.inputs, &id);
1480                     v.nest_scope(ex.id, |v| v.visit_expr(body))
1481                 });
1482             }
1483             ast::ExprKind::ForLoop(ref pattern, ref subexpression, ref block, _) |
1484             ast::ExprKind::WhileLet(ref pattern, ref subexpression, ref block, _) => {
1485                 let value = self.span.snippet(subexpression.span);
1486                 self.process_var_decl(pattern, value);
1487                 debug!("for loop, walk sub-expr: {:?}", subexpression.node);
1488                 visit::walk_expr(self, subexpression);
1489                 visit::walk_block(self, block);
1490             }
1491             ast::ExprKind::IfLet(ref pattern, ref subexpression, ref block, ref opt_else) => {
1492                 let value = self.span.snippet(subexpression.span);
1493                 self.process_var_decl(pattern, value);
1494                 visit::walk_expr(self, subexpression);
1495                 visit::walk_block(self, block);
1496                 opt_else.as_ref().map(|el| visit::walk_expr(self, el));
1497             }
1498             ast::ExprKind::Repeat(ref element, ref count) => {
1499                 self.visit_expr(element);
1500                 self.nest_tables(count.id, |v| v.visit_expr(count));
1501             }
1502             // In particular, we take this branch for call and path expressions,
1503             // where we'll index the idents involved just by continuing to walk.
1504             _ => {
1505                 visit::walk_expr(self, ex)
1506             }
1507         }
1508     }
1509
1510     fn visit_mac(&mut self, mac: &'l ast::Mac) {
1511         // These shouldn't exist in the AST at this point, log a span bug.
1512         span_bug!(mac.span, "macro invocation should have been expanded out of AST");
1513     }
1514
1515     fn visit_pat(&mut self, p: &'l ast::Pat) {
1516         self.process_macro_use(p.span, p.id);
1517         self.process_pat(p);
1518     }
1519
1520     fn visit_arm(&mut self, arm: &'l ast::Arm) {
1521         let mut collector = PathCollector::new();
1522         for pattern in &arm.pats {
1523             // collect paths from the arm's patterns
1524             collector.visit_pat(&pattern);
1525             self.visit_pat(&pattern);
1526         }
1527
1528         // This is to get around borrow checking, because we need mut self to call process_path.
1529         let mut paths_to_process = vec![];
1530
1531         // process collected paths
1532         for &(id, ref p, immut, ref_kind) in &collector.collected_paths {
1533             match self.save_ctxt.get_path_def(id) {
1534                 Def::Local(def_id) => {
1535                     let id = self.tcx.hir.as_local_node_id(def_id).unwrap();
1536                     let mut value = if immut == ast::Mutability::Immutable {
1537                         self.span.snippet(p.span).to_string()
1538                     } else {
1539                         "<mutable>".to_string()
1540                     };
1541                     let typ = self.save_ctxt.tables.node_types
1542                                   .get(&id).map(|t| t.to_string()).unwrap_or(String::new());
1543                     value.push_str(": ");
1544                     value.push_str(&typ);
1545
1546                     assert!(p.segments.len() == 1,
1547                             "qualified path for local variable def in arm");
1548                     if !self.span.filter_generated(Some(p.span), p.span) {
1549                         self.dumper.variable(VariableData {
1550                             span: p.span,
1551                             kind: VariableKind::Local,
1552                             id: id,
1553                             name: path_to_string(p),
1554                             qualname: format!("{}${}", path_to_string(p), id),
1555                             value: value,
1556                             type_value: typ,
1557                             scope: CRATE_NODE_ID,
1558                             parent: None,
1559                             visibility: Visibility::Inherited,
1560                             docs: String::new(),
1561                             sig: None,
1562                             attributes: vec![],
1563                         }.lower(self.tcx));
1564                     }
1565                 }
1566                 Def::StructCtor(..) | Def::VariantCtor(..) |
1567                 Def::Const(..) | Def::AssociatedConst(..) |
1568                 Def::Struct(..) | Def::Variant(..) |
1569                 Def::TyAlias(..) | Def::AssociatedTy(..) |
1570                 Def::SelfTy(..) => {
1571                     paths_to_process.push((id, p.clone(), Some(ref_kind)))
1572                 }
1573                 def => error!("unexpected definition kind when processing collected paths: {:?}",
1574                               def),
1575             }
1576         }
1577
1578         for &(id, ref path, ref_kind) in &paths_to_process {
1579             self.process_path(id, path, ref_kind);
1580         }
1581         walk_list!(self, visit_expr, &arm.guard);
1582         self.visit_expr(&arm.body);
1583     }
1584
1585     fn visit_path(&mut self, p: &'l ast::Path, id: NodeId) {
1586         self.process_path(id, p, None);
1587     }
1588
1589     fn visit_stmt(&mut self, s: &'l ast::Stmt) {
1590         self.process_macro_use(s.span, s.id);
1591         visit::walk_stmt(self, s)
1592     }
1593
1594     fn visit_local(&mut self, l: &'l ast::Local) {
1595         self.process_macro_use(l.span, l.id);
1596         let value = l.init.as_ref().map(|i| self.span.snippet(i.span)).unwrap_or(String::new());
1597         self.process_var_decl(&l.pat, value);
1598
1599         // Just walk the initialiser and type (don't want to walk the pattern again).
1600         walk_list!(self, visit_ty, &l.ty);
1601         walk_list!(self, visit_expr, &l.init);
1602     }
1603
1604     fn visit_foreign_item(&mut self, item: &'l ast::ForeignItem) {
1605         match item.node {
1606             ast::ForeignItemKind::Fn(ref decl, ref generics) => {
1607                 if let Some(fn_data) = self.save_ctxt.get_extern_item_data(item) {
1608                     down_cast_data!(fn_data, FunctionData, item.span);
1609                     if !self.span.filter_generated(Some(fn_data.span), item.span) {
1610                         self.dumper.function(fn_data.clone().lower(self.tcx));
1611                     }
1612
1613                     self.nest_tables(item.id, |v| v.process_formals(&decl.inputs,
1614                                                                     &fn_data.qualname));
1615                     self.process_generic_params(generics, item.span, &fn_data.qualname, item.id);
1616                 }
1617
1618                 for arg in &decl.inputs {
1619                     self.visit_ty(&arg.ty);
1620                 }
1621
1622                 if let ast::FunctionRetTy::Ty(ref ret_ty) = decl.output {
1623                     self.visit_ty(&ret_ty);
1624                 }
1625             }
1626             ast::ForeignItemKind::Static(ref ty, _) => {
1627                 if let Some(var_data) = self.save_ctxt.get_extern_item_data(item) {
1628                     down_cast_data!(var_data, VariableData, item.span);
1629                     if !self.span.filter_generated(Some(var_data.span), item.span) {
1630                         self.dumper.variable(var_data.lower(self.tcx));
1631                     }
1632                 }
1633
1634                 self.visit_ty(ty);
1635             }
1636         }
1637     }
1638 }