src/librustc/metadata/decoder.rs

   1 // Copyright 2012-2014 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 // Decoding metadata from a single crate's metadata
  12
  13 #![allow(non_camel_case_types)]
  14
  15 pub use self::DefLike::*;
  16 use self::Family::*;
  17
  18 use front::map as ast_map;
  19 use rustc_front::print::pprust;
  20 use rustc_front::hir;
  21
  22 use back::svh::Svh;
  23 use metadata::cstore::crate_metadata;
  24 use metadata::common::*;
  25 use metadata::csearch::MethodInfo;
  26 use metadata::csearch;
  27 use metadata::cstore;
  28 use metadata::encoder::def_to_u64;
  29 use metadata::index;
  30 use metadata::inline::InlinedItem;
  31 use metadata::tydecode::TyDecoder;
  32 use middle::def;
  33 use middle::def_id::{DefId, LOCAL_CRATE};
  34 use middle::lang_items;
  35 use middle::subst;
  36 use middle::ty::{ImplContainer, TraitContainer};
  37 use middle::ty::{self, RegionEscape, Ty};
  38 use util::nodemap::FnvHashMap;
  39
  40 use std::cell::{Cell, RefCell};
  41 use std::io::prelude::*;
  42 use std::io;
  43 use std::rc::Rc;
  44 use std::str;
  45
  46 use rbml::reader;
  47 use rbml;
  48 use serialize::Decodable;
  49 use rustc_front::attr;
  50 use syntax::parse::token::{IdentInterner, special_idents};
  51 use syntax::parse::token;
  52 use syntax::ast;
  53 use syntax::abi;
  54 use syntax::codemap;
  55 use syntax::ptr::P;
  56
  57
  58 pub type Cmd<'a> = &'a crate_metadata;
  59
  60 impl crate_metadata {
  61     fn get_item(&self, item_id: ast::NodeId) -> Option<rbml::Doc> {
  62         self.index.lookup_item(self.data(), item_id).map(|pos| {
  63             reader::doc_at(self.data(), pos as usize).unwrap().doc
  64         })
  65     }
  66
  67     fn lookup_item(&self, item_id: ast::NodeId) -> rbml::Doc {
  68         match self.get_item(item_id) {
  69             None => panic!("lookup_item: id not found: {}", item_id),
  70             Some(d) => d
  71         }
  72     }
  73 }
  74
  75 pub fn load_index(data: &[u8]) -> index::Index {
  76     let index = reader::get_doc(rbml::Doc::new(data), tag_index);
  77     index::Index::from_buf(index.data, index.start, index.end)
  78 }
  79
  80 #[derive(Debug, PartialEq)]
  81 enum Family {
  82     ImmStatic,             // c
  83     MutStatic,             // b
  84     Fn,                    // f
  85     CtorFn,                // o
  86     StaticMethod,          // F
  87     Method,                // h
  88     Type,                  // y
  89     Mod,                   // m
  90     ForeignMod,            // n
  91     Enum,                  // t
  92     TupleVariant,          // v
  93     StructVariant,         // V
  94     Impl,                  // i
  95     DefaultImpl,              // d
  96     Trait,                 // I
  97     Struct,                // S
  98     PublicField,           // g
  99     InheritedField,        // N
 100     Constant,              // C
 101 }
 102
 103 fn item_family(item: rbml::Doc) -> Family {
 104     let fam = reader::get_doc(item, tag_items_data_item_family);
 105     match reader::doc_as_u8(fam) as char {
 106       'C' => Constant,
 107       'c' => ImmStatic,
 108       'b' => MutStatic,
 109       'f' => Fn,
 110       'o' => CtorFn,
 111       'F' => StaticMethod,
 112       'h' => Method,
 113       'y' => Type,
 114       'm' => Mod,
 115       'n' => ForeignMod,
 116       't' => Enum,
 117       'v' => TupleVariant,
 118       'V' => StructVariant,
 119       'i' => Impl,
 120       'd' => DefaultImpl,
 121       'I' => Trait,
 122       'S' => Struct,
 123       'g' => PublicField,
 124       'N' => InheritedField,
 125        c => panic!("unexpected family char: {}", c)
 126     }
 127 }
 128
 129 fn item_visibility(item: rbml::Doc) -> hir::Visibility {
 130     match reader::maybe_get_doc(item, tag_items_data_item_visibility) {
 131         None => hir::Public,
 132         Some(visibility_doc) => {
 133             match reader::doc_as_u8(visibility_doc) as char {
 134                 'y' => hir::Public,
 135                 'i' => hir::Inherited,
 136                 _ => panic!("unknown visibility character")
 137             }
 138         }
 139     }
 140 }
 141
 142 fn fn_constness(item: rbml::Doc) -> hir::Constness {
 143     match reader::maybe_get_doc(item, tag_items_data_item_constness) {
 144         None => hir::Constness::NotConst,
 145         Some(constness_doc) => {
 146             match reader::doc_as_u8(constness_doc) as char {
 147                 'c' => hir::Constness::Const,
 148                 'n' => hir::Constness::NotConst,
 149                 _ => panic!("unknown constness character")
 150             }
 151         }
 152     }
 153 }
 154
 155 fn item_sort(item: rbml::Doc) -> Option<char> {
 156     reader::tagged_docs(item, tag_item_trait_item_sort).nth(0).map(|doc| {
 157         doc.as_str_slice().as_bytes()[0] as char
 158     })
 159 }
 160
 161 fn item_symbol(item: rbml::Doc) -> String {
 162     reader::get_doc(item, tag_items_data_item_symbol).as_str().to_string()
 163 }
 164
 165 fn translated_def_id(cdata: Cmd, d: rbml::Doc) -> DefId {
 166     let id = reader::doc_as_u64(d);
 167     let def_id = DefId { krate: (id >> 32) as u32, node: id as u32 };
 168     translate_def_id(cdata, def_id)
 169 }
 170
 171 fn item_parent_item(cdata: Cmd, d: rbml::Doc) -> Option<DefId> {
 172     reader::tagged_docs(d, tag_items_data_parent_item).nth(0).map(|did| {
 173         translated_def_id(cdata, did)
 174     })
 175 }
 176
 177 fn item_require_parent_item(cdata: Cmd, d: rbml::Doc) -> DefId {
 178     translated_def_id(cdata, reader::get_doc(d, tag_items_data_parent_item))
 179 }
 180
 181 fn item_def_id(d: rbml::Doc, cdata: Cmd) -> DefId {
 182     translated_def_id(cdata, reader::get_doc(d, tag_def_id))
 183 }
 184
 185 fn get_provided_source(d: rbml::Doc, cdata: Cmd) -> Option<DefId> {
 186     reader::maybe_get_doc(d, tag_item_method_provided_source).map(|doc| {
 187         translated_def_id(cdata, doc)
 188     })
 189 }
 190
 191 fn reexports<'a>(d: rbml::Doc<'a>) -> reader::TaggedDocsIterator<'a> {
 192     reader::tagged_docs(d, tag_items_data_item_reexport)
 193 }
 194
 195 fn variant_disr_val(d: rbml::Doc) -> Option<ty::Disr> {
 196     reader::maybe_get_doc(d, tag_disr_val).and_then(|val_doc| {
 197         reader::with_doc_data(val_doc, |data| {
 198             str::from_utf8(data).ok().and_then(|s| s.parse().ok())
 199         })
 200     })
 201 }
 202
 203 fn doc_type<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>, cdata: Cmd) -> Ty<'tcx> {
 204     let tp = reader::get_doc(doc, tag_items_data_item_type);
 205     TyDecoder::with_doc(tcx, cdata.cnum, tp,
 206                         &mut |_, did| translate_def_id(cdata, did))
 207         .parse_ty()
 208 }
 209
 210 fn maybe_doc_type<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>, cdata: Cmd) -> Option<Ty<'tcx>> {
 211     reader::maybe_get_doc(doc, tag_items_data_item_type).map(|tp| {
 212         TyDecoder::with_doc(tcx, cdata.cnum, tp,
 213                             &mut |_, did| translate_def_id(cdata, did))
 214             .parse_ty()
 215     })
 216 }
 217
 218 fn doc_method_fty<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>,
 219                         cdata: Cmd) -> ty::BareFnTy<'tcx> {
 220     let tp = reader::get_doc(doc, tag_item_method_fty);
 221     TyDecoder::with_doc(tcx, cdata.cnum, tp,
 222                         &mut |_, did| translate_def_id(cdata, did))
 223         .parse_bare_fn_ty()
 224 }
 225
 226 pub fn item_type<'tcx>(_item_id: DefId, item: rbml::Doc,
 227                        tcx: &ty::ctxt<'tcx>, cdata: Cmd) -> Ty<'tcx> {
 228     doc_type(item, tcx, cdata)
 229 }
 230
 231 fn doc_trait_ref<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>, cdata: Cmd)
 232                        -> ty::TraitRef<'tcx> {
 233     TyDecoder::with_doc(tcx, cdata.cnum, doc,
 234                         &mut |_, did| translate_def_id(cdata, did))
 235         .parse_trait_ref()
 236 }
 237
 238 fn item_trait_ref<'tcx>(doc: rbml::Doc, tcx: &ty::ctxt<'tcx>, cdata: Cmd)
 239                         -> ty::TraitRef<'tcx> {
 240     let tp = reader::get_doc(doc, tag_item_trait_ref);
 241     doc_trait_ref(tp, tcx, cdata)
 242 }
 243
 244 fn item_path(item_doc: rbml::Doc) -> Vec<ast_map::PathElem> {
 245     let path_doc = reader::get_doc(item_doc, tag_path);
 246     reader::docs(path_doc).filter_map(|(tag, elt_doc)| {
 247         if tag == tag_path_elem_mod {
 248             let s = elt_doc.as_str_slice();
 249             Some(ast_map::PathMod(token::intern(s)))
 250         } else if tag == tag_path_elem_name {
 251             let s = elt_doc.as_str_slice();
 252             Some(ast_map::PathName(token::intern(s)))
 253         } else {
 254             // ignore tag_path_len element
 255             None
 256         }
 257     }).collect()
 258 }
 259
 260 fn item_name(intr: &IdentInterner, item: rbml::Doc) -> ast::Name {
 261     let name = reader::get_doc(item, tag_paths_data_name);
 262     let string = name.as_str_slice();
 263     match intr.find(string) {
 264         None => token::intern(string),
 265         Some(val) => val,
 266     }
 267 }
 268
 269 fn item_to_def_like(cdata: Cmd, item: rbml::Doc, did: DefId) -> DefLike {
 270     let fam = item_family(item);
 271     match fam {
 272         Constant  => {
 273             // Check whether we have an associated const item.
 274             if item_sort(item) == Some('C') {
 275                 DlDef(def::DefAssociatedConst(did))
 276             } else {
 277                 // Regular const item.
 278                 DlDef(def::DefConst(did))
 279             }
 280         }
 281         ImmStatic => DlDef(def::DefStatic(did, false)),
 282         MutStatic => DlDef(def::DefStatic(did, true)),
 283         Struct    => DlDef(def::DefStruct(did)),
 284         Fn        => DlDef(def::DefFn(did, false)),
 285         CtorFn    => DlDef(def::DefFn(did, true)),
 286         Method | StaticMethod => {
 287             DlDef(def::DefMethod(did))
 288         }
 289         Type => {
 290             if item_sort(item) == Some('t') {
 291                 let trait_did = item_require_parent_item(cdata, item);
 292                 DlDef(def::DefAssociatedTy(trait_did, did))
 293             } else {
 294                 DlDef(def::DefTy(did, false))
 295             }
 296         }
 297         Mod => DlDef(def::DefMod(did)),
 298         ForeignMod => DlDef(def::DefForeignMod(did)),
 299         StructVariant => {
 300             let enum_did = item_require_parent_item(cdata, item);
 301             DlDef(def::DefVariant(enum_did, did, true))
 302         }
 303         TupleVariant => {
 304             let enum_did = item_require_parent_item(cdata, item);
 305             DlDef(def::DefVariant(enum_did, did, false))
 306         }
 307         Trait => DlDef(def::DefTrait(did)),
 308         Enum => DlDef(def::DefTy(did, true)),
 309         Impl | DefaultImpl => DlImpl(did),
 310         PublicField | InheritedField => DlField,
 311     }
 312 }
 313
 314 fn parse_unsafety(item_doc: rbml::Doc) -> hir::Unsafety {
 315     let unsafety_doc = reader::get_doc(item_doc, tag_unsafety);
 316     if reader::doc_as_u8(unsafety_doc) != 0 {
 317         hir::Unsafety::Unsafe
 318     } else {
 319         hir::Unsafety::Normal
 320     }
 321 }
 322
 323 fn parse_paren_sugar(item_doc: rbml::Doc) -> bool {
 324     let paren_sugar_doc = reader::get_doc(item_doc, tag_paren_sugar);
 325     reader::doc_as_u8(paren_sugar_doc) != 0
 326 }
 327
 328 fn parse_polarity(item_doc: rbml::Doc) -> hir::ImplPolarity {
 329     let polarity_doc = reader::get_doc(item_doc, tag_polarity);
 330     if reader::doc_as_u8(polarity_doc) != 0 {
 331         hir::ImplPolarity::Negative
 332     } else {
 333         hir::ImplPolarity::Positive
 334     }
 335 }
 336
 337 fn parse_associated_type_names(item_doc: rbml::Doc) -> Vec<ast::Name> {
 338     let names_doc = reader::get_doc(item_doc, tag_associated_type_names);
 339     reader::tagged_docs(names_doc, tag_associated_type_name)
 340         .map(|name_doc| token::intern(name_doc.as_str_slice()))
 341         .collect()
 342 }
 343
 344 pub fn get_trait_def<'tcx>(cdata: Cmd,
 345                            item_id: ast::NodeId,
 346                            tcx: &ty::ctxt<'tcx>) -> ty::TraitDef<'tcx>
 347 {
 348     let item_doc = cdata.lookup_item(item_id);
 349     let generics = doc_generics(item_doc, tcx, cdata, tag_item_generics);
 350     let unsafety = parse_unsafety(item_doc);
 351     let associated_type_names = parse_associated_type_names(item_doc);
 352     let paren_sugar = parse_paren_sugar(item_doc);
 353
 354     ty::TraitDef {
 355         paren_sugar: paren_sugar,
 356         unsafety: unsafety,
 357         generics: generics,
 358         trait_ref: item_trait_ref(item_doc, tcx, cdata),
 359         associated_type_names: associated_type_names,
 360         nonblanket_impls: RefCell::new(FnvHashMap()),
 361         blanket_impls: RefCell::new(vec![]),
 362         flags: Cell::new(ty::TraitFlags::NO_TRAIT_FLAGS)
 363     }
 364 }
 365
 366 pub fn get_adt_def<'tcx>(intr: &IdentInterner,
 367                          cdata: Cmd,
 368                          item_id: ast::NodeId,
 369                          tcx: &ty::ctxt<'tcx>) -> ty::AdtDefMaster<'tcx>
 370 {
 371     fn get_enum_variants<'tcx>(intr: &IdentInterner,
 372                                cdata: Cmd,
 373                                doc: rbml::Doc,
 374                                tcx: &ty::ctxt<'tcx>) -> Vec<ty::VariantDefData<'tcx, 'tcx>> {
 375         let mut disr_val = 0;
 376         reader::tagged_docs(doc, tag_items_data_item_variant).map(|p| {
 377             let did = translated_def_id(cdata, p);
 378             let item = cdata.lookup_item(did.node);
 379
 380             if let Some(disr) = variant_disr_val(item) {
 381                 disr_val = disr;
 382             }
 383             let disr = disr_val;
 384             disr_val = disr_val.wrapping_add(1);
 385
 386             ty::VariantDefData {
 387                 did: did,
 388                 name: item_name(intr, item),
 389                 fields: get_variant_fields(intr, cdata, item, tcx),
 390                 disr_val: disr
 391             }
 392         }).collect()
 393     }
 394     fn get_variant_fields<'tcx>(intr: &IdentInterner,
 395                                 cdata: Cmd,
 396                                 doc: rbml::Doc,
 397                                 tcx: &ty::ctxt<'tcx>) -> Vec<ty::FieldDefData<'tcx, 'tcx>> {
 398         reader::tagged_docs(doc, tag_item_field).map(|f| {
 399             let ff = item_family(f);
 400             match ff {
 401                 PublicField | InheritedField => {},
 402                 _ => tcx.sess.bug(&format!("expected field, found {:?}", ff))
 403             };
 404             ty::FieldDefData::new(item_def_id(f, cdata),
 405                                   item_name(intr, f),
 406                                   struct_field_family_to_visibility(ff))
 407         }).chain(reader::tagged_docs(doc, tag_item_unnamed_field).map(|f| {
 408             let ff = item_family(f);
 409             ty::FieldDefData::new(item_def_id(f, cdata),
 410                                   special_idents::unnamed_field.name,
 411                                   struct_field_family_to_visibility(ff))
 412         })).collect()
 413     }
 414     fn get_struct_variant<'tcx>(intr: &IdentInterner,
 415                                 cdata: Cmd,
 416                                 doc: rbml::Doc,
 417                                 did: DefId,
 418                                 tcx: &ty::ctxt<'tcx>) -> ty::VariantDefData<'tcx, 'tcx> {
 419         ty::VariantDefData {
 420             did: did,
 421             name: item_name(intr, doc),
 422             fields: get_variant_fields(intr, cdata, doc, tcx),
 423             disr_val: 0
 424         }
 425     }
 426
 427     let doc = cdata.lookup_item(item_id);
 428     let did = DefId { krate: cdata.cnum, node: item_id };
 429     let (kind, variants) = match item_family(doc) {
 430         Enum => (ty::AdtKind::Enum,
 431                  get_enum_variants(intr, cdata, doc, tcx)),
 432         Struct => (ty::AdtKind::Struct,
 433                    vec![get_struct_variant(intr, cdata, doc, did, tcx)]),
 434         _ => tcx.sess.bug("get_adt_def called on a non-ADT")
 435     };
 436
 437     let adt = tcx.intern_adt_def(did, kind, variants);
 438
 439     // this needs to be done *after* the variant is interned,
 440     // to support recursive structures
 441     for variant in &adt.variants {
 442         if variant.kind() == ty::VariantKind::Tuple &&
 443             adt.adt_kind() == ty::AdtKind::Enum {
 444             // tuple-like enum variant fields aren't real items - get the types
 445             // from the ctor.
 446             debug!("evaluating the ctor-type of {:?}",
 447                    variant.name);
 448             let ctor_ty = get_type(cdata, variant.did.node, tcx).ty;
 449             debug!("evaluating the ctor-type of {:?}.. {:?}",
 450                    variant.name,
 451                    ctor_ty);
 452             let field_tys = match ctor_ty.sty {
 453                 ty::TyBareFn(_, &ty::BareFnTy { sig: ty::Binder(ty::FnSig {
 454                     ref inputs, ..
 455                 }), ..}) => {
 456                     // tuple-struct constructors don't have escaping regions
 457                     assert!(!inputs.has_escaping_regions());
 458                     inputs
 459                 },
 460                 _ => tcx.sess.bug("tuple-variant ctor is not an ADT")
 461             };
 462             for (field, &ty) in variant.fields.iter().zip(field_tys.iter()) {
 463                 field.fulfill_ty(ty);
 464             }
 465         } else {
 466             for field in &variant.fields {
 467                 debug!("evaluating the type of {:?}::{:?}", variant.name, field.name);
 468                 let ty = get_type(cdata, field.did.node, tcx).ty;
 469                 field.fulfill_ty(ty);
 470                 debug!("evaluating the type of {:?}::{:?}: {:?}",
 471                        variant.name, field.name, ty);
 472             }
 473         }
 474     }
 475
 476     adt
 477 }
 478
 479 pub fn get_predicates<'tcx>(cdata: Cmd,
 480                             item_id: ast::NodeId,
 481                             tcx: &ty::ctxt<'tcx>)
 482                             -> ty::GenericPredicates<'tcx>
 483 {
 484     let item_doc = cdata.lookup_item(item_id);
 485     doc_predicates(item_doc, tcx, cdata, tag_item_generics)
 486 }
 487
 488 pub fn get_super_predicates<'tcx>(cdata: Cmd,
 489                                   item_id: ast::NodeId,
 490                                   tcx: &ty::ctxt<'tcx>)
 491                                   -> ty::GenericPredicates<'tcx>
 492 {
 493     let item_doc = cdata.lookup_item(item_id);
 494     doc_predicates(item_doc, tcx, cdata, tag_item_super_predicates)
 495 }
 496
 497 pub fn get_type<'tcx>(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt<'tcx>)
 498                       -> ty::TypeScheme<'tcx>
 499 {
 500     let item_doc = cdata.lookup_item(id);
 501     let t = item_type(DefId { krate: cdata.cnum, node: id }, item_doc, tcx,
 502                       cdata);
 503     let generics = doc_generics(item_doc, tcx, cdata, tag_item_generics);
 504     ty::TypeScheme {
 505         generics: generics,
 506         ty: t
 507     }
 508 }
 509
 510 pub fn get_stability(cdata: Cmd, id: ast::NodeId) -> Option<attr::Stability> {
 511     let item = cdata.lookup_item(id);
 512     reader::maybe_get_doc(item, tag_items_data_item_stability).map(|doc| {
 513         let mut decoder = reader::Decoder::new(doc);
 514         Decodable::decode(&mut decoder).unwrap()
 515     })
 516 }
 517
 518 pub fn get_repr_attrs(cdata: Cmd, id: ast::NodeId) -> Vec<attr::ReprAttr> {
 519     let item = cdata.lookup_item(id);
 520     match reader::maybe_get_doc(item, tag_items_data_item_repr).map(|doc| {
 521         let mut decoder = reader::Decoder::new(doc);
 522         Decodable::decode(&mut decoder).unwrap()
 523     }) {
 524         Some(attrs) => attrs,
 525         None => Vec::new(),
 526     }
 527 }
 528
 529 pub fn get_impl_polarity<'tcx>(cdata: Cmd,
 530                                id: ast::NodeId)
 531                                -> Option<hir::ImplPolarity>
 532 {
 533     let item_doc = cdata.lookup_item(id);
 534     let fam = item_family(item_doc);
 535     match fam {
 536         Family::Impl => {
 537             Some(parse_polarity(item_doc))
 538         }
 539         _ => None
 540     }
 541 }
 542
 543 pub fn get_custom_coerce_unsized_kind<'tcx>(
 544     cdata: Cmd,
 545     id: ast::NodeId)
 546     -> Option<ty::adjustment::CustomCoerceUnsized>
 547 {
 548     let item_doc = cdata.lookup_item(id);
 549     reader::maybe_get_doc(item_doc, tag_impl_coerce_unsized_kind).map(|kind_doc| {
 550         let mut decoder = reader::Decoder::new(kind_doc);
 551         Decodable::decode(&mut decoder).unwrap()
 552     })
 553 }
 554
 555 pub fn get_impl_trait<'tcx>(cdata: Cmd,
 556                             id: ast::NodeId,
 557                             tcx: &ty::ctxt<'tcx>)
 558                             -> Option<ty::TraitRef<'tcx>>
 559 {
 560     let item_doc = cdata.lookup_item(id);
 561     let fam = item_family(item_doc);
 562     match fam {
 563         Family::Impl | Family::DefaultImpl => {
 564             reader::maybe_get_doc(item_doc, tag_item_trait_ref).map(|tp| {
 565                 doc_trait_ref(tp, tcx, cdata)
 566             })
 567         }
 568         _ => None
 569     }
 570 }
 571
 572 pub fn get_symbol(cdata: Cmd, id: ast::NodeId) -> String {
 573     return item_symbol(cdata.lookup_item(id));
 574 }
 575
 576 /// If you have a crate_metadata, call get_symbol instead
 577 pub fn get_symbol_from_buf(data: &[u8], id: ast::NodeId) -> String {
 578     let index = load_index(data);
 579     let pos = index.lookup_item(data, id).unwrap();
 580     let doc = reader::doc_at(data, pos as usize).unwrap().doc;
 581     item_symbol(doc)
 582 }
 583
 584 // Something that a name can resolve to.
 585 #[derive(Copy, Clone, Debug)]
 586 pub enum DefLike {
 587     DlDef(def::Def),
 588     DlImpl(DefId),
 589     DlField
 590 }
 591
 592 /// Iterates over the language items in the given crate.
 593 pub fn each_lang_item<F>(cdata: Cmd, mut f: F) -> bool where
 594     F: FnMut(ast::NodeId, usize) -> bool,
 595 {
 596     let root = rbml::Doc::new(cdata.data());
 597     let lang_items = reader::get_doc(root, tag_lang_items);
 598     reader::tagged_docs(lang_items, tag_lang_items_item).all(|item_doc| {
 599         let id_doc = reader::get_doc(item_doc, tag_lang_items_item_id);
 600         let id = reader::doc_as_u32(id_doc) as usize;
 601         let node_id_doc = reader::get_doc(item_doc,
 602                                           tag_lang_items_item_node_id);
 603         let node_id = reader::doc_as_u32(node_id_doc) as ast::NodeId;
 604
 605         f(node_id, id)
 606     })
 607 }
 608
 609 fn each_child_of_item_or_crate<F, G>(intr: Rc<IdentInterner>,
 610                                      cdata: Cmd,
 611                                      item_doc: rbml::Doc,
 612                                      mut get_crate_data: G,
 613                                      mut callback: F) where
 614     F: FnMut(DefLike, ast::Name, hir::Visibility),
 615     G: FnMut(ast::CrateNum) -> Rc<crate_metadata>,
 616 {
 617     // Iterate over all children.
 618     for child_info_doc in reader::tagged_docs(item_doc, tag_mod_child) {
 619         let child_def_id = translated_def_id(cdata, child_info_doc);
 620
 621         // This item may be in yet another crate if it was the child of a
 622         // reexport.
 623         let crate_data = if child_def_id.krate == cdata.cnum {
 624             None
 625         } else {
 626             Some(get_crate_data(child_def_id.krate))
 627         };
 628         let crate_data = match crate_data {
 629             Some(ref cdata) => &**cdata,
 630             None => cdata
 631         };
 632
 633         // Get the item.
 634         match crate_data.get_item(child_def_id.node) {
 635             None => {}
 636             Some(child_item_doc) => {
 637                 // Hand off the item to the callback.
 638                 let child_name = item_name(&*intr, child_item_doc);
 639                 let def_like = item_to_def_like(crate_data, child_item_doc, child_def_id);
 640                 let visibility = item_visibility(child_item_doc);
 641                 callback(def_like, child_name, visibility);
 642             }
 643         }
 644     }
 645
 646     // As a special case, iterate over all static methods of
 647     // associated implementations too. This is a bit of a botch.
 648     // --pcwalton
 649     for inherent_impl_def_id_doc in reader::tagged_docs(item_doc,
 650                                                              tag_items_data_item_inherent_impl) {
 651         let inherent_impl_def_id = item_def_id(inherent_impl_def_id_doc, cdata);
 652         if let Some(inherent_impl_doc) = cdata.get_item(inherent_impl_def_id.node) {
 653             for impl_item_def_id_doc in reader::tagged_docs(inherent_impl_doc,
 654                                                                  tag_item_impl_item) {
 655                 let impl_item_def_id = item_def_id(impl_item_def_id_doc,
 656                                                    cdata);
 657                 if let Some(impl_method_doc) = cdata.get_item(impl_item_def_id.node) {
 658                     if let StaticMethod = item_family(impl_method_doc) {
 659                         // Hand off the static method to the callback.
 660                         let static_method_name = item_name(&*intr, impl_method_doc);
 661                         let static_method_def_like = item_to_def_like(cdata, impl_method_doc,
 662                                                                       impl_item_def_id);
 663                         callback(static_method_def_like,
 664                                  static_method_name,
 665                                  item_visibility(impl_method_doc));
 666                     }
 667                 }
 668             }
 669         }
 670     }
 671
 672     for reexport_doc in reexports(item_doc) {
 673         let def_id_doc = reader::get_doc(reexport_doc,
 674                                          tag_items_data_item_reexport_def_id);
 675         let child_def_id = translated_def_id(cdata, def_id_doc);
 676
 677         let name_doc = reader::get_doc(reexport_doc,
 678                                        tag_items_data_item_reexport_name);
 679         let name = name_doc.as_str_slice();
 680
 681         // This reexport may be in yet another crate.
 682         let crate_data = if child_def_id.krate == cdata.cnum {
 683             None
 684         } else {
 685             Some(get_crate_data(child_def_id.krate))
 686         };
 687         let crate_data = match crate_data {
 688             Some(ref cdata) => &**cdata,
 689             None => cdata
 690         };
 691
 692         // Get the item.
 693         if let Some(child_item_doc) = crate_data.get_item(child_def_id.node) {
 694             // Hand off the item to the callback.
 695             let def_like = item_to_def_like(crate_data, child_item_doc, child_def_id);
 696             // These items have a public visibility because they're part of
 697             // a public re-export.
 698             callback(def_like, token::intern(name), hir::Public);
 699         }
 700     }
 701 }
 702
 703 /// Iterates over each child of the given item.
 704 pub fn each_child_of_item<F, G>(intr: Rc<IdentInterner>,
 705                                cdata: Cmd,
 706                                id: ast::NodeId,
 707                                get_crate_data: G,
 708                                callback: F) where
 709     F: FnMut(DefLike, ast::Name, hir::Visibility),
 710     G: FnMut(ast::CrateNum) -> Rc<crate_metadata>,
 711 {
 712     // Find the item.
 713     let item_doc = match cdata.get_item(id) {
 714         None => return,
 715         Some(item_doc) => item_doc,
 716     };
 717
 718     each_child_of_item_or_crate(intr,
 719                                 cdata,
 720                                 item_doc,
 721                                 get_crate_data,
 722                                 callback)
 723 }
 724
 725 /// Iterates over all the top-level crate items.
 726 pub fn each_top_level_item_of_crate<F, G>(intr: Rc<IdentInterner>,
 727                                           cdata: Cmd,
 728                                           get_crate_data: G,
 729                                           callback: F) where
 730     F: FnMut(DefLike, ast::Name, hir::Visibility),
 731     G: FnMut(ast::CrateNum) -> Rc<crate_metadata>,
 732 {
 733     let root_doc = rbml::Doc::new(cdata.data());
 734     let misc_info_doc = reader::get_doc(root_doc, tag_misc_info);
 735     let crate_items_doc = reader::get_doc(misc_info_doc,
 736                                           tag_misc_info_crate_items);
 737
 738     each_child_of_item_or_crate(intr,
 739                                 cdata,
 740                                 crate_items_doc,
 741                                 get_crate_data,
 742                                 callback)
 743 }
 744
 745 pub fn get_item_path(cdata: Cmd, id: ast::NodeId) -> Vec<ast_map::PathElem> {
 746     item_path(cdata.lookup_item(id))
 747 }
 748
 749 pub fn get_item_name(intr: &IdentInterner, cdata: Cmd, id: ast::NodeId) -> ast::Name {
 750     item_name(intr, cdata.lookup_item(id))
 751 }
 752
 753 pub type DecodeInlinedItem<'a> =
 754     Box<for<'tcx> FnMut(Cmd,
 755                         &ty::ctxt<'tcx>,
 756                         Vec<ast_map::PathElem>,
 757                         rbml::Doc)
 758                         -> Result<&'tcx InlinedItem, Vec<ast_map::PathElem>> + 'a>;
 759
 760 pub fn maybe_get_item_ast<'tcx>(cdata: Cmd, tcx: &ty::ctxt<'tcx>, id: ast::NodeId,
 761                                 mut decode_inlined_item: DecodeInlinedItem)
 762                                 -> csearch::FoundAst<'tcx> {
 763     debug!("Looking up item: {}", id);
 764     let item_doc = cdata.lookup_item(id);
 765     let path = item_path(item_doc).split_last().unwrap().1.to_vec();
 766     match decode_inlined_item(cdata, tcx, path, item_doc) {
 767         Ok(ii) => csearch::FoundAst::Found(ii),
 768         Err(path) => {
 769             match item_parent_item(cdata, item_doc) {
 770                 Some(did) => {
 771                     let parent_item = cdata.lookup_item(did.node);
 772                     match decode_inlined_item(cdata, tcx, path, parent_item) {
 773                         Ok(ii) => csearch::FoundAst::FoundParent(did, ii),
 774                         Err(_) => csearch::FoundAst::NotFound
 775                     }
 776                 }
 777                 None => csearch::FoundAst::NotFound
 778             }
 779         }
 780     }
 781 }
 782
 783 fn get_explicit_self(item: rbml::Doc) -> ty::ExplicitSelfCategory {
 784     fn get_mutability(ch: u8) -> hir::Mutability {
 785         match ch as char {
 786             'i' => hir::MutImmutable,
 787             'm' => hir::MutMutable,
 788             _ => panic!("unknown mutability character: `{}`", ch as char),
 789         }
 790     }
 791
 792     let explicit_self_doc = reader::get_doc(item, tag_item_trait_method_explicit_self);
 793     let string = explicit_self_doc.as_str_slice();
 794
 795     let explicit_self_kind = string.as_bytes()[0];
 796     match explicit_self_kind as char {
 797         's' => ty::StaticExplicitSelfCategory,
 798         'v' => ty::ByValueExplicitSelfCategory,
 799         '~' => ty::ByBoxExplicitSelfCategory,
 800         // FIXME(#4846) expl. region
 801         '&' => {
 802             ty::ByReferenceExplicitSelfCategory(
 803                 ty::ReEmpty,
 804                 get_mutability(string.as_bytes()[1]))
 805         }
 806         _ => panic!("unknown self type code: `{}`", explicit_self_kind as char)
 807     }
 808 }
 809
 810 /// Returns the def IDs of all the items in the given implementation.
 811 pub fn get_impl_items(cdata: Cmd, impl_id: ast::NodeId)
 812                       -> Vec<ty::ImplOrTraitItemId> {
 813     reader::tagged_docs(cdata.lookup_item(impl_id), tag_item_impl_item).map(|doc| {
 814         let def_id = item_def_id(doc, cdata);
 815         match item_sort(doc) {
 816             Some('C') => ty::ConstTraitItemId(def_id),
 817             Some('r') | Some('p') => ty::MethodTraitItemId(def_id),
 818             Some('t') => ty::TypeTraitItemId(def_id),
 819             _ => panic!("unknown impl item sort"),
 820         }
 821     }).collect()
 822 }
 823
 824 pub fn get_trait_name(intr: Rc<IdentInterner>,
 825                       cdata: Cmd,
 826                       id: ast::NodeId)
 827                       -> ast::Name {
 828     let doc = cdata.lookup_item(id);
 829     item_name(&*intr, doc)
 830 }
 831
 832 pub fn is_static_method(cdata: Cmd, id: ast::NodeId) -> bool {
 833     let doc = cdata.lookup_item(id);
 834     match item_sort(doc) {
 835         Some('r') | Some('p') => {
 836             get_explicit_self(doc) == ty::StaticExplicitSelfCategory
 837         }
 838         _ => false
 839     }
 840 }
 841
 842 pub fn get_impl_or_trait_item<'tcx>(intr: Rc<IdentInterner>,
 843                                     cdata: Cmd,
 844                                     id: ast::NodeId,
 845                                     tcx: &ty::ctxt<'tcx>)
 846                                     -> ty::ImplOrTraitItem<'tcx> {
 847     let item_doc = cdata.lookup_item(id);
 848
 849     let def_id = item_def_id(item_doc, cdata);
 850
 851     let container_id = item_require_parent_item(cdata, item_doc);
 852     let container_doc = cdata.lookup_item(container_id.node);
 853     let container = match item_family(container_doc) {
 854         Trait => TraitContainer(container_id),
 855         _ => ImplContainer(container_id),
 856     };
 857
 858     let name = item_name(&*intr, item_doc);
 859     let vis = item_visibility(item_doc);
 860
 861     match item_sort(item_doc) {
 862         Some('C') => {
 863             let ty = doc_type(item_doc, tcx, cdata);
 864             let default = get_provided_source(item_doc, cdata);
 865             ty::ConstTraitItem(Rc::new(ty::AssociatedConst {
 866                 name: name,
 867                 ty: ty,
 868                 vis: vis,
 869                 def_id: def_id,
 870                 container: container,
 871                 default: default,
 872             }))
 873         }
 874         Some('r') | Some('p') => {
 875             let generics = doc_generics(item_doc, tcx, cdata, tag_method_ty_generics);
 876             let predicates = doc_predicates(item_doc, tcx, cdata, tag_method_ty_generics);
 877             let fty = doc_method_fty(item_doc, tcx, cdata);
 878             let explicit_self = get_explicit_self(item_doc);
 879             let provided_source = get_provided_source(item_doc, cdata);
 880
 881             ty::MethodTraitItem(Rc::new(ty::Method::new(name,
 882                                                         generics,
 883                                                         predicates,
 884                                                         fty,
 885                                                         explicit_self,
 886                                                         vis,
 887                                                         def_id,
 888                                                         container,
 889                                                         provided_source)))
 890         }
 891         Some('t') => {
 892             let ty = maybe_doc_type(item_doc, tcx, cdata);
 893             ty::TypeTraitItem(Rc::new(ty::AssociatedType {
 894                 name: name,
 895                 ty: ty,
 896                 vis: vis,
 897                 def_id: def_id,
 898                 container: container,
 899             }))
 900         }
 901         _ => panic!("unknown impl/trait item sort"),
 902     }
 903 }
 904
 905 pub fn get_trait_item_def_ids(cdata: Cmd, id: ast::NodeId)
 906                               -> Vec<ty::ImplOrTraitItemId> {
 907     let item = cdata.lookup_item(id);
 908     reader::tagged_docs(item, tag_item_trait_item).map(|mth| {
 909         let def_id = item_def_id(mth, cdata);
 910         match item_sort(mth) {
 911             Some('C') => ty::ConstTraitItemId(def_id),
 912             Some('r') | Some('p') => ty::MethodTraitItemId(def_id),
 913             Some('t') => ty::TypeTraitItemId(def_id),
 914             _ => panic!("unknown trait item sort"),
 915         }
 916     }).collect()
 917 }
 918
 919 pub fn get_item_variances(cdata: Cmd, id: ast::NodeId) -> ty::ItemVariances {
 920     let item_doc = cdata.lookup_item(id);
 921     let variance_doc = reader::get_doc(item_doc, tag_item_variances);
 922     let mut decoder = reader::Decoder::new(variance_doc);
 923     Decodable::decode(&mut decoder).unwrap()
 924 }
 925
 926 pub fn get_provided_trait_methods<'tcx>(intr: Rc<IdentInterner>,
 927                                         cdata: Cmd,
 928                                         id: ast::NodeId,
 929                                         tcx: &ty::ctxt<'tcx>)
 930                                         -> Vec<Rc<ty::Method<'tcx>>> {
 931     let item = cdata.lookup_item(id);
 932
 933     reader::tagged_docs(item, tag_item_trait_item).filter_map(|mth_id| {
 934         let did = item_def_id(mth_id, cdata);
 935         let mth = cdata.lookup_item(did.node);
 936
 937         if item_sort(mth) == Some('p') {
 938             let trait_item = get_impl_or_trait_item(intr.clone(),
 939                                                     cdata,
 940                                                     did.node,
 941                                                     tcx);
 942             if let ty::MethodTraitItem(ref method) = trait_item {
 943                 Some((*method).clone())
 944             } else {
 945                 None
 946             }
 947         } else {
 948             None
 949         }
 950     }).collect()
 951 }
 952
 953 pub fn get_associated_consts<'tcx>(intr: Rc<IdentInterner>,
 954                                    cdata: Cmd,
 955                                    id: ast::NodeId,
 956                                    tcx: &ty::ctxt<'tcx>)
 957                                    -> Vec<Rc<ty::AssociatedConst<'tcx>>> {
 958     let item = cdata.lookup_item(id);
 959
 960     [tag_item_trait_item, tag_item_impl_item].iter().flat_map(|&tag| {
 961         reader::tagged_docs(item, tag).filter_map(|ac_id| {
 962             let did = item_def_id(ac_id, cdata);
 963             let ac_doc = cdata.lookup_item(did.node);
 964
 965             if item_sort(ac_doc) == Some('C') {
 966                 let trait_item = get_impl_or_trait_item(intr.clone(),
 967                                                         cdata,
 968                                                         did.node,
 969                                                         tcx);
 970                 if let ty::ConstTraitItem(ref ac) = trait_item {
 971                     Some((*ac).clone())
 972                 } else {
 973                     None
 974                 }
 975             } else {
 976                 None
 977             }
 978         })
 979     }).collect()
 980 }
 981
 982 pub fn get_type_name_if_impl(cdata: Cmd,
 983                              node_id: ast::NodeId) -> Option<ast::Name> {
 984     let item = cdata.lookup_item(node_id);
 985     if item_family(item) != Impl {
 986         return None;
 987     }
 988
 989     reader::tagged_docs(item, tag_item_impl_type_basename).nth(0).map(|doc| {
 990         token::intern(doc.as_str_slice())
 991     })
 992 }
 993
 994 pub fn get_methods_if_impl(intr: Rc<IdentInterner>,
 995                                   cdata: Cmd,
 996                                   node_id: ast::NodeId)
 997                                -> Option<Vec<MethodInfo> > {
 998     let item = cdata.lookup_item(node_id);
 999     if item_family(item) != Impl {
1000         return None;
1001     }
1002
1003     // If this impl implements a trait, don't consider it.
1004     if reader::tagged_docs(item, tag_item_trait_ref).next().is_some() {
1005         return None;
1006     }
1007
1008     let impl_method_ids = reader::tagged_docs(item, tag_item_impl_item)
1009         .map(|impl_method_doc| item_def_id(impl_method_doc, cdata));
1010
1011     let mut impl_methods = Vec::new();
1012     for impl_method_id in impl_method_ids {
1013         let impl_method_doc = cdata.lookup_item(impl_method_id.node);
1014         let family = item_family(impl_method_doc);
1015         match family {
1016             StaticMethod | Method => {
1017                 impl_methods.push(MethodInfo {
1018                     name: item_name(&*intr, impl_method_doc),
1019                     def_id: item_def_id(impl_method_doc, cdata),
1020                     vis: item_visibility(impl_method_doc),
1021                 });
1022             }
1023             _ => {}
1024         }
1025     }
1026
1027     return Some(impl_methods);
1028 }
1029
1030 /// If node_id is the constructor of a tuple struct, retrieve the NodeId of
1031 /// the actual type definition, otherwise, return None
1032 pub fn get_tuple_struct_definition_if_ctor(cdata: Cmd,
1033                                            node_id: ast::NodeId)
1034     -> Option<DefId>
1035 {
1036     let item = cdata.lookup_item(node_id);
1037     reader::tagged_docs(item, tag_items_data_item_is_tuple_struct_ctor).next().map(|_| {
1038         item_require_parent_item(cdata, item)
1039     })
1040 }
1041
1042 pub fn get_item_attrs(cdata: Cmd,
1043                       orig_node_id: ast::NodeId)
1044                       -> Vec<hir::Attribute> {
1045     // The attributes for a tuple struct are attached to the definition, not the ctor;
1046     // we assume that someone passing in a tuple struct ctor is actually wanting to
1047     // look at the definition
1048     let node_id = get_tuple_struct_definition_if_ctor(cdata, orig_node_id);
1049     let node_id = node_id.map(|x| x.node).unwrap_or(orig_node_id);
1050     let item = cdata.lookup_item(node_id);
1051     get_attributes(item)
1052 }
1053
1054 pub fn get_struct_field_attrs(cdata: Cmd) -> FnvHashMap<ast::NodeId, Vec<hir::Attribute>> {
1055     let data = rbml::Doc::new(cdata.data());
1056     let fields = reader::get_doc(data, tag_struct_fields);
1057     reader::tagged_docs(fields, tag_struct_field).map(|field| {
1058         let id = reader::doc_as_u32(reader::get_doc(field, tag_struct_field_id));
1059         let attrs = get_attributes(field);
1060         (id, attrs)
1061     }).collect()
1062 }
1063
1064 fn struct_field_family_to_visibility(family: Family) -> hir::Visibility {
1065     match family {
1066       PublicField => hir::Public,
1067       InheritedField => hir::Inherited,
1068       _ => panic!()
1069     }
1070 }
1071
1072 pub fn get_struct_field_names(intr: &IdentInterner, cdata: Cmd, id: ast::NodeId)
1073     -> Vec<ast::Name> {
1074     let item = cdata.lookup_item(id);
1075     reader::tagged_docs(item, tag_item_field).map(|an_item| {
1076         item_name(intr, an_item)
1077     }).chain(reader::tagged_docs(item, tag_item_unnamed_field).map(|_| {
1078         special_idents::unnamed_field.name
1079     })).collect()
1080 }
1081
1082 fn get_meta_items(md: rbml::Doc) -> Vec<P<hir::MetaItem>> {
1083     reader::tagged_docs(md, tag_meta_item_word).map(|meta_item_doc| {
1084         let nd = reader::get_doc(meta_item_doc, tag_meta_item_name);
1085         let n = token::intern_and_get_ident(nd.as_str_slice());
1086         attr::mk_word_item(n)
1087     }).chain(reader::tagged_docs(md, tag_meta_item_name_value).map(|meta_item_doc| {
1088         let nd = reader::get_doc(meta_item_doc, tag_meta_item_name);
1089         let vd = reader::get_doc(meta_item_doc, tag_meta_item_value);
1090         let n = token::intern_and_get_ident(nd.as_str_slice());
1091         let v = token::intern_and_get_ident(vd.as_str_slice());
1092         // FIXME (#623): Should be able to decode MetaNameValue variants,
1093         // but currently the encoder just drops them
1094         attr::mk_name_value_item_str(n, v)
1095     })).chain(reader::tagged_docs(md, tag_meta_item_list).map(|meta_item_doc| {
1096         let nd = reader::get_doc(meta_item_doc, tag_meta_item_name);
1097         let n = token::intern_and_get_ident(nd.as_str_slice());
1098         let subitems = get_meta_items(meta_item_doc);
1099         attr::mk_list_item(n, subitems)
1100     })).collect()
1101 }
1102
1103 fn get_attributes(md: rbml::Doc) -> Vec<hir::Attribute> {
1104     match reader::maybe_get_doc(md, tag_attributes) {
1105         Some(attrs_d) => {
1106             reader::tagged_docs(attrs_d, tag_attribute).map(|attr_doc| {
1107                 let is_sugared_doc = reader::doc_as_u8(
1108                     reader::get_doc(attr_doc, tag_attribute_is_sugared_doc)
1109                 ) == 1;
1110                 let meta_items = get_meta_items(attr_doc);
1111                 // Currently it's only possible to have a single meta item on
1112                 // an attribute
1113                 assert_eq!(meta_items.len(), 1);
1114                 let meta_item = meta_items.into_iter().nth(0).unwrap();
1115                 codemap::Spanned {
1116                     node: hir::Attribute_ {
1117                         id: attr::mk_attr_id(),
1118                         style: hir::AttrOuter,
1119                         value: meta_item,
1120                         is_sugared_doc: is_sugared_doc,
1121                     },
1122                     span: codemap::DUMMY_SP
1123                 }
1124             }).collect()
1125         },
1126         None => vec![],
1127     }
1128 }
1129
1130 fn list_crate_attributes(md: rbml::Doc, hash: &Svh,
1131                          out: &mut io::Write) -> io::Result<()> {
1132     try!(write!(out, "=Crate Attributes ({})=\n", *hash));
1133
1134     let r = get_attributes(md);
1135     for attr in &r {
1136         try!(write!(out, "{}\n", pprust::attribute_to_string(attr)));
1137     }
1138
1139     write!(out, "\n\n")
1140 }
1141
1142 pub fn get_crate_attributes(data: &[u8]) -> Vec<hir::Attribute> {
1143     get_attributes(rbml::Doc::new(data))
1144 }
1145
1146 #[derive(Clone)]
1147 pub struct CrateDep {
1148     pub cnum: ast::CrateNum,
1149     pub name: String,
1150     pub hash: Svh,
1151     pub explicitly_linked: bool,
1152 }
1153
1154 pub fn get_crate_deps(data: &[u8]) -> Vec<CrateDep> {
1155     let cratedoc = rbml::Doc::new(data);
1156     let depsdoc = reader::get_doc(cratedoc, tag_crate_deps);
1157
1158     fn docstr(doc: rbml::Doc, tag_: usize) -> String {
1159         let d = reader::get_doc(doc, tag_);
1160         d.as_str_slice().to_string()
1161     }
1162
1163     reader::tagged_docs(depsdoc, tag_crate_dep).enumerate().map(|(crate_num, depdoc)| {
1164         let name = docstr(depdoc, tag_crate_dep_crate_name);
1165         let hash = Svh::new(&docstr(depdoc, tag_crate_dep_hash));
1166         let doc = reader::get_doc(depdoc, tag_crate_dep_explicitly_linked);
1167         let explicitly_linked = reader::doc_as_u8(doc) != 0;
1168         CrateDep {
1169             cnum: crate_num as u32 + 1,
1170             name: name,
1171             hash: hash,
1172             explicitly_linked: explicitly_linked,
1173         }
1174     }).collect()
1175 }
1176
1177 fn list_crate_deps(data: &[u8], out: &mut io::Write) -> io::Result<()> {
1178     try!(write!(out, "=External Dependencies=\n"));
1179     for dep in &get_crate_deps(data) {
1180         try!(write!(out, "{} {}-{}\n", dep.cnum, dep.name, dep.hash));
1181     }
1182     try!(write!(out, "\n"));
1183     Ok(())
1184 }
1185
1186 pub fn maybe_get_crate_hash(data: &[u8]) -> Option<Svh> {
1187     let cratedoc = rbml::Doc::new(data);
1188     reader::maybe_get_doc(cratedoc, tag_crate_hash).map(|doc| {
1189         Svh::new(doc.as_str_slice())
1190     })
1191 }
1192
1193 pub fn get_crate_hash(data: &[u8]) -> Svh {
1194     let cratedoc = rbml::Doc::new(data);
1195     let hashdoc = reader::get_doc(cratedoc, tag_crate_hash);
1196     Svh::new(hashdoc.as_str_slice())
1197 }
1198
1199 pub fn maybe_get_crate_name(data: &[u8]) -> Option<String> {
1200     let cratedoc = rbml::Doc::new(data);
1201     reader::maybe_get_doc(cratedoc, tag_crate_crate_name).map(|doc| {
1202         doc.as_str_slice().to_string()
1203     })
1204 }
1205
1206 pub fn get_crate_triple(data: &[u8]) -> Option<String> {
1207     let cratedoc = rbml::Doc::new(data);
1208     let triple_doc = reader::maybe_get_doc(cratedoc, tag_crate_triple);
1209     triple_doc.map(|s| s.as_str().to_string())
1210 }
1211
1212 pub fn get_crate_name(data: &[u8]) -> String {
1213     maybe_get_crate_name(data).expect("no crate name in crate")
1214 }
1215
1216 pub fn list_crate_metadata(bytes: &[u8], out: &mut io::Write) -> io::Result<()> {
1217     let hash = get_crate_hash(bytes);
1218     let md = rbml::Doc::new(bytes);
1219     try!(list_crate_attributes(md, &hash, out));
1220     list_crate_deps(bytes, out)
1221 }
1222
1223 // Translates a def_id from an external crate to a def_id for the current
1224 // compilation environment. We use this when trying to load types from
1225 // external crates - if those types further refer to types in other crates
1226 // then we must translate the crate number from that encoded in the external
1227 // crate to the correct local crate number.
1228 pub fn translate_def_id(cdata: Cmd, did: DefId) -> DefId {
1229     if did.is_local() {
1230         return DefId { krate: cdata.cnum, node: did.node };
1231     }
1232
1233     match cdata.cnum_map.borrow().get(&did.krate) {
1234         Some(&n) => {
1235             DefId {
1236                 krate: n,
1237                 node: did.node,
1238             }
1239         }
1240         None => panic!("didn't find a crate in the cnum_map")
1241     }
1242 }
1243
1244 // Translate a DefId from the current compilation environment to a DefId
1245 // for an external crate.
1246 fn reverse_translate_def_id(cdata: Cmd, did: DefId) -> Option<DefId> {
1247     if did.krate == cdata.cnum {
1248         return Some(DefId { krate: LOCAL_CRATE, node: did.node });
1249     }
1250
1251     for (&local, &global) in cdata.cnum_map.borrow().iter() {
1252         if global == did.krate {
1253             return Some(DefId { krate: local, node: did.node });
1254         }
1255     }
1256
1257     None
1258 }
1259
1260 pub fn each_inherent_implementation_for_type<F>(cdata: Cmd,
1261                                                 id: ast::NodeId,
1262                                                 mut callback: F)
1263     where F: FnMut(DefId),
1264 {
1265     let item_doc = cdata.lookup_item(id);
1266     for impl_doc in reader::tagged_docs(item_doc, tag_items_data_item_inherent_impl) {
1267         if reader::maybe_get_doc(impl_doc, tag_item_trait_ref).is_none() {
1268             callback(item_def_id(impl_doc, cdata));
1269         }
1270     }
1271 }
1272
1273 pub fn each_implementation_for_trait<F>(cdata: Cmd,
1274                                         def_id: DefId,
1275                                         mut callback: F) where
1276     F: FnMut(DefId),
1277 {
1278     if cdata.cnum == def_id.krate {
1279         let item_doc = cdata.lookup_item(def_id.node);
1280         for impl_doc in reader::tagged_docs(item_doc, tag_items_data_item_extension_impl) {
1281             callback(item_def_id(impl_doc, cdata));
1282         }
1283         return;
1284     }
1285
1286     // Do a reverse lookup beforehand to avoid touching the crate_num
1287     // hash map in the loop below.
1288     if let Some(crate_local_did) = reverse_translate_def_id(cdata, def_id) {
1289         let def_id_u64 = def_to_u64(crate_local_did);
1290
1291         let impls_doc = reader::get_doc(rbml::Doc::new(cdata.data()), tag_impls);
1292         for impl_doc in reader::tagged_docs(impls_doc, tag_impls_impl) {
1293             let impl_trait = reader::get_doc(impl_doc, tag_impls_impl_trait_def_id);
1294             if reader::doc_as_u64(impl_trait) == def_id_u64 {
1295                 callback(item_def_id(impl_doc, cdata));
1296             }
1297         }
1298     }
1299 }
1300
1301 pub fn get_trait_of_item(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt)
1302                          -> Option<DefId> {
1303     let item_doc = cdata.lookup_item(id);
1304     let parent_item_id = match item_parent_item(cdata, item_doc) {
1305         None => return None,
1306         Some(item_id) => item_id,
1307     };
1308     let parent_item_doc = cdata.lookup_item(parent_item_id.node);
1309     match item_family(parent_item_doc) {
1310         Trait => Some(item_def_id(parent_item_doc, cdata)),
1311         Impl | DefaultImpl => {
1312             reader::maybe_get_doc(parent_item_doc, tag_item_trait_ref)
1313                 .map(|_| item_trait_ref(parent_item_doc, tcx, cdata).def_id)
1314         }
1315         _ => None
1316     }
1317 }
1318
1319
1320 pub fn get_native_libraries(cdata: Cmd)
1321                             -> Vec<(cstore::NativeLibraryKind, String)> {
1322     let libraries = reader::get_doc(rbml::Doc::new(cdata.data()),
1323                                     tag_native_libraries);
1324     reader::tagged_docs(libraries, tag_native_libraries_lib).map(|lib_doc| {
1325         let kind_doc = reader::get_doc(lib_doc, tag_native_libraries_kind);
1326         let name_doc = reader::get_doc(lib_doc, tag_native_libraries_name);
1327         let kind: cstore::NativeLibraryKind =
1328             cstore::NativeLibraryKind::from_u32(reader::doc_as_u32(kind_doc)).unwrap();
1329         let name = name_doc.as_str().to_string();
1330         (kind, name)
1331     }).collect()
1332 }
1333
1334 pub fn get_plugin_registrar_fn(data: &[u8]) -> Option<ast::NodeId> {
1335     reader::maybe_get_doc(rbml::Doc::new(data), tag_plugin_registrar_fn)
1336         .map(|doc| reader::doc_as_u32(doc))
1337 }
1338
1339 pub fn each_exported_macro<F>(data: &[u8], intr: &IdentInterner, mut f: F) where
1340     F: FnMut(ast::Name, Vec<hir::Attribute>, String) -> bool,
1341 {
1342     let macros = reader::get_doc(rbml::Doc::new(data), tag_macro_defs);
1343     for macro_doc in reader::tagged_docs(macros, tag_macro_def) {
1344         let name = item_name(intr, macro_doc);
1345         let attrs = get_attributes(macro_doc);
1346         let body = reader::get_doc(macro_doc, tag_macro_def_body);
1347         if !f(name, attrs, body.as_str().to_string()) {
1348             break;
1349         }
1350     }
1351 }
1352
1353 pub fn get_dylib_dependency_formats(cdata: Cmd)
1354     -> Vec<(ast::CrateNum, cstore::LinkagePreference)>
1355 {
1356     let formats = reader::get_doc(rbml::Doc::new(cdata.data()),
1357                                   tag_dylib_dependency_formats);
1358     let mut result = Vec::new();
1359
1360     debug!("found dylib deps: {}", formats.as_str_slice());
1361     for spec in formats.as_str_slice().split(',') {
1362         if spec.is_empty() { continue }
1363         let cnum = spec.split(':').nth(0).unwrap();
1364         let link = spec.split(':').nth(1).unwrap();
1365         let cnum: ast::CrateNum = cnum.parse().unwrap();
1366         let cnum = match cdata.cnum_map.borrow().get(&cnum) {
1367             Some(&n) => n,
1368             None => panic!("didn't find a crate in the cnum_map")
1369         };
1370         result.push((cnum, if link == "d" {
1371             cstore::RequireDynamic
1372         } else {
1373             cstore::RequireStatic
1374         }));
1375     }
1376     return result;
1377 }
1378
1379 pub fn get_missing_lang_items(cdata: Cmd)
1380     -> Vec<lang_items::LangItem>
1381 {
1382     let items = reader::get_doc(rbml::Doc::new(cdata.data()), tag_lang_items);
1383     reader::tagged_docs(items, tag_lang_items_missing).map(|missing_docs| {
1384         lang_items::LangItem::from_u32(reader::doc_as_u32(missing_docs)).unwrap()
1385     }).collect()
1386 }
1387
1388 pub fn get_method_arg_names(cdata: Cmd, id: ast::NodeId) -> Vec<String> {
1389     let method_doc = cdata.lookup_item(id);
1390     match reader::maybe_get_doc(method_doc, tag_method_argument_names) {
1391         Some(args_doc) => {
1392             reader::tagged_docs(args_doc, tag_method_argument_name).map(|name_doc| {
1393                 name_doc.as_str_slice().to_string()
1394             }).collect()
1395         },
1396         None => vec![],
1397     }
1398 }
1399
1400 pub fn get_reachable_ids(cdata: Cmd) -> Vec<DefId> {
1401     let items = reader::get_doc(rbml::Doc::new(cdata.data()),
1402                                 tag_reachable_ids);
1403     reader::tagged_docs(items, tag_reachable_id).map(|doc| {
1404         DefId {
1405             krate: cdata.cnum,
1406             node: reader::doc_as_u32(doc),
1407         }
1408     }).collect()
1409 }
1410
1411 pub fn is_typedef(cdata: Cmd, id: ast::NodeId) -> bool {
1412     let item_doc = cdata.lookup_item(id);
1413     match item_family(item_doc) {
1414         Type => true,
1415         _ => false,
1416     }
1417 }
1418
1419 pub fn is_const_fn(cdata: Cmd, id: ast::NodeId) -> bool {
1420     let item_doc = cdata.lookup_item(id);
1421     match fn_constness(item_doc) {
1422         hir::Constness::Const => true,
1423         hir::Constness::NotConst => false,
1424     }
1425 }
1426
1427 pub fn is_impl(cdata: Cmd, id: ast::NodeId) -> bool {
1428     let item_doc = cdata.lookup_item(id);
1429     match item_family(item_doc) {
1430         Impl => true,
1431         _ => false,
1432     }
1433 }
1434
1435 fn doc_generics<'tcx>(base_doc: rbml::Doc,
1436                       tcx: &ty::ctxt<'tcx>,
1437                       cdata: Cmd,
1438                       tag: usize)
1439                       -> ty::Generics<'tcx>
1440 {
1441     let doc = reader::get_doc(base_doc, tag);
1442
1443     let mut types = subst::VecPerParamSpace::empty();
1444     for p in reader::tagged_docs(doc, tag_type_param_def) {
1445         let bd =
1446             TyDecoder::with_doc(tcx, cdata.cnum, p,
1447                                 &mut |_, did| translate_def_id(cdata, did))
1448             .parse_type_param_def();
1449         types.push(bd.space, bd);
1450     }
1451
1452     let mut regions = subst::VecPerParamSpace::empty();
1453     for rp_doc in reader::tagged_docs(doc, tag_region_param_def) {
1454         let ident_str_doc = reader::get_doc(rp_doc,
1455                                             tag_region_param_def_ident);
1456         let name = item_name(&*token::get_ident_interner(), ident_str_doc);
1457         let def_id_doc = reader::get_doc(rp_doc,
1458                                          tag_region_param_def_def_id);
1459         let def_id = translated_def_id(cdata, def_id_doc);
1460
1461         let doc = reader::get_doc(rp_doc, tag_region_param_def_space);
1462         let space = subst::ParamSpace::from_uint(reader::doc_as_u64(doc) as usize);
1463
1464         let doc = reader::get_doc(rp_doc, tag_region_param_def_index);
1465         let index = reader::doc_as_u64(doc) as u32;
1466
1467         let bounds = reader::tagged_docs(rp_doc, tag_items_data_region).map(|p| {
1468             TyDecoder::with_doc(tcx, cdata.cnum, p,
1469                                 &mut |_, did| translate_def_id(cdata, did))
1470             .parse_region()
1471         }).collect();
1472
1473         regions.push(space, ty::RegionParameterDef { name: name,
1474                                                      def_id: def_id,
1475                                                      space: space,
1476                                                      index: index,
1477                                                      bounds: bounds });
1478     }
1479
1480     ty::Generics { types: types, regions: regions }
1481 }
1482
1483 fn doc_predicates<'tcx>(base_doc: rbml::Doc,
1484                         tcx: &ty::ctxt<'tcx>,
1485                         cdata: Cmd,
1486                         tag: usize)
1487                         -> ty::GenericPredicates<'tcx>
1488 {
1489     let doc = reader::get_doc(base_doc, tag);
1490
1491     let mut predicates = subst::VecPerParamSpace::empty();
1492     for predicate_doc in reader::tagged_docs(doc, tag_predicate) {
1493         let space_doc = reader::get_doc(predicate_doc, tag_predicate_space);
1494         let space = subst::ParamSpace::from_uint(reader::doc_as_u8(space_doc) as usize);
1495
1496         let data_doc = reader::get_doc(predicate_doc, tag_predicate_data);
1497         let data =
1498             TyDecoder::with_doc(tcx, cdata.cnum, data_doc,
1499                                 &mut |_, did| translate_def_id(cdata, did))
1500             .parse_predicate();
1501
1502         predicates.push(space, data);
1503     }
1504
1505     ty::GenericPredicates { predicates: predicates }
1506 }
1507
1508 pub fn is_defaulted_trait(cdata: Cmd, trait_id: ast::NodeId) -> bool {
1509     let trait_doc = cdata.lookup_item(trait_id);
1510     assert!(item_family(trait_doc) == Family::Trait);
1511     let defaulted_doc = reader::get_doc(trait_doc, tag_defaulted_trait);
1512     reader::doc_as_u8(defaulted_doc) != 0
1513 }
1514
1515 pub fn is_default_impl(cdata: Cmd, impl_id: ast::NodeId) -> bool {
1516     let impl_doc = cdata.lookup_item(impl_id);
1517     item_family(impl_doc) == Family::DefaultImpl
1518 }
1519
1520 pub fn get_imported_filemaps(metadata: &[u8]) -> Vec<codemap::FileMap> {
1521     let crate_doc = rbml::Doc::new(metadata);
1522     let cm_doc = reader::get_doc(crate_doc, tag_codemap);
1523
1524     reader::tagged_docs(cm_doc, tag_codemap_filemap).map(|filemap_doc| {
1525         let mut decoder = reader::Decoder::new(filemap_doc);
1526         Decodable::decode(&mut decoder).unwrap()
1527     }).collect()
1528 }
1529
1530 pub fn is_extern_fn(cdata: Cmd, id: ast::NodeId, tcx: &ty::ctxt) -> bool {
1531     let item_doc = match cdata.get_item(id) {
1532         Some(doc) => doc,
1533         None => return false,
1534     };
1535     if let Fn = item_family(item_doc) {
1536         let ty::TypeScheme { generics, ty } = get_type(cdata, id, tcx);
1537         generics.types.is_empty() && match ty.sty {
1538             ty::TyBareFn(_, fn_ty) => fn_ty.abi != abi::Rust,
1539             _ => false,
1540         }
1541     } else {
1542         false
1543     }
1544 }