src/librustc_privacy/lib.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 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  12        html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  13        html_root_url = "https://doc.rust-lang.org/nightly/")]
  14 #![deny(warnings)]
  15
  16 #![feature(rustc_diagnostic_macros)]
  17
  18 #[macro_use] extern crate rustc;
  19 #[macro_use] extern crate syntax;
  20 extern crate rustc_typeck;
  21 extern crate syntax_pos;
  22
  23 use rustc::hir::{self, PatKind};
  24 use rustc::hir::def::Def;
  25 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, CrateNum, DefId};
  26 use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
  27 use rustc::hir::itemlikevisit::DeepVisitor;
  28 use rustc::lint;
  29 use rustc::middle::privacy::{AccessLevel, AccessLevels};
  30 use rustc::ty::{self, TyCtxt, Ty, TypeFoldable};
  31 use rustc::ty::fold::TypeVisitor;
  32 use rustc::ty::maps::Providers;
  33 use rustc::util::nodemap::NodeSet;
  34 use syntax::ast::{self, CRATE_NODE_ID, Ident};
  35 use syntax::symbol::keywords;
  36 use syntax_pos::Span;
  37
  38 use std::cmp;
  39 use std::mem::replace;
  40 use std::rc::Rc;
  41
  42 mod diagnostics;
  43
  44 ////////////////////////////////////////////////////////////////////////////////
  45 /// Visitor used to determine if pub(restricted) is used anywhere in the crate.
  46 ///
  47 /// This is done so that `private_in_public` warnings can be turned into hard errors
  48 /// in crates that have been updated to use pub(restricted).
  49 ////////////////////////////////////////////////////////////////////////////////
  50 struct PubRestrictedVisitor<'a, 'tcx: 'a> {
  51     tcx:  TyCtxt<'a, 'tcx, 'tcx>,
  52     has_pub_restricted: bool,
  53 }
  54
  55 impl<'a, 'tcx> Visitor<'tcx> for PubRestrictedVisitor<'a, 'tcx> {
  56     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
  57         NestedVisitorMap::All(&self.tcx.hir)
  58     }
  59     fn visit_vis(&mut self, vis: &'tcx hir::Visibility) {
  60         self.has_pub_restricted = self.has_pub_restricted || vis.is_pub_restricted();
  61     }
  62 }
  63
  64 ////////////////////////////////////////////////////////////////////////////////
  65 /// The embargo visitor, used to determine the exports of the ast
  66 ////////////////////////////////////////////////////////////////////////////////
  67
  68 struct EmbargoVisitor<'a, 'tcx: 'a> {
  69     tcx: TyCtxt<'a, 'tcx, 'tcx>,
  70
  71     // Accessibility levels for reachable nodes
  72     access_levels: AccessLevels,
  73     // Previous accessibility level, None means unreachable
  74     prev_level: Option<AccessLevel>,
  75     // Have something changed in the level map?
  76     changed: bool,
  77 }
  78
  79 struct ReachEverythingInTheInterfaceVisitor<'b, 'a: 'b, 'tcx: 'a> {
  80     item_def_id: DefId,
  81     ev: &'b mut EmbargoVisitor<'a, 'tcx>,
  82 }
  83
  84 impl<'a, 'tcx> EmbargoVisitor<'a, 'tcx> {
  85     fn item_ty_level(&self, item_def_id: DefId) -> Option<AccessLevel> {
  86         let ty_def_id = match self.tcx.type_of(item_def_id).sty {
  87             ty::TyAdt(adt, _) => adt.did,
  88             ty::TyForeign(did) => did,
  89             ty::TyDynamic(ref obj, ..) if obj.principal().is_some() =>
  90                 obj.principal().unwrap().def_id(),
  91             ty::TyProjection(ref proj) => proj.trait_ref(self.tcx).def_id,
  92             _ => return Some(AccessLevel::Public)
  93         };
  94         if let Some(node_id) = self.tcx.hir.as_local_node_id(ty_def_id) {
  95             self.get(node_id)
  96         } else {
  97             Some(AccessLevel::Public)
  98         }
  99     }
 100
 101     fn impl_trait_level(&self, impl_def_id: DefId) -> Option<AccessLevel> {
 102         if let Some(trait_ref) = self.tcx.impl_trait_ref(impl_def_id) {
 103             if let Some(node_id) = self.tcx.hir.as_local_node_id(trait_ref.def_id) {
 104                 return self.get(node_id);
 105             }
 106         }
 107         Some(AccessLevel::Public)
 108     }
 109
 110     fn get(&self, id: ast::NodeId) -> Option<AccessLevel> {
 111         self.access_levels.map.get(&id).cloned()
 112     }
 113
 114     // Updates node level and returns the updated level
 115     fn update(&mut self, id: ast::NodeId, level: Option<AccessLevel>) -> Option<AccessLevel> {
 116         let old_level = self.get(id);
 117         // Accessibility levels can only grow
 118         if level > old_level {
 119             self.access_levels.map.insert(id, level.unwrap());
 120             self.changed = true;
 121             level
 122         } else {
 123             old_level
 124         }
 125     }
 126
 127     fn reach<'b>(&'b mut self, item_id: ast::NodeId)
 128                  -> ReachEverythingInTheInterfaceVisitor<'b, 'a, 'tcx> {
 129         ReachEverythingInTheInterfaceVisitor {
 130             item_def_id: self.tcx.hir.local_def_id(item_id),
 131             ev: self,
 132         }
 133     }
 134 }
 135
 136 impl<'a, 'tcx> Visitor<'tcx> for EmbargoVisitor<'a, 'tcx> {
 137     /// We want to visit items in the context of their containing
 138     /// module and so forth, so supply a crate for doing a deep walk.
 139     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 140         NestedVisitorMap::All(&self.tcx.hir)
 141     }
 142
 143     fn visit_item(&mut self, item: &'tcx hir::Item) {
 144         let inherited_item_level = match item.node {
 145             // Impls inherit level from their types and traits
 146             hir::ItemImpl(..) => {
 147                 let def_id = self.tcx.hir.local_def_id(item.id);
 148                 cmp::min(self.item_ty_level(def_id), self.impl_trait_level(def_id))
 149             }
 150             // Foreign mods inherit level from parents
 151             hir::ItemForeignMod(..) => {
 152                 self.prev_level
 153             }
 154             // Other `pub` items inherit levels from parents
 155             hir::ItemConst(..) | hir::ItemEnum(..) | hir::ItemExternCrate(..) |
 156             hir::ItemGlobalAsm(..) | hir::ItemFn(..) | hir::ItemMod(..) |
 157             hir::ItemStatic(..) | hir::ItemStruct(..) |
 158             hir::ItemTrait(..) | hir::ItemTraitAlias(..) |
 159             hir::ItemTy(..) | hir::ItemUnion(..) | hir::ItemUse(..) => {
 160                 if item.vis == hir::Public { self.prev_level } else { None }
 161             }
 162         };
 163
 164         // Update level of the item itself
 165         let item_level = self.update(item.id, inherited_item_level);
 166
 167         // Update levels of nested things
 168         match item.node {
 169             hir::ItemEnum(ref def, _) => {
 170                 for variant in &def.variants {
 171                     let variant_level = self.update(variant.node.data.id(), item_level);
 172                     for field in variant.node.data.fields() {
 173                         self.update(field.id, variant_level);
 174                     }
 175                 }
 176             }
 177             hir::ItemImpl(.., None, _, ref impl_item_refs) => {
 178                 for impl_item_ref in impl_item_refs {
 179                     if impl_item_ref.vis == hir::Public {
 180                         self.update(impl_item_ref.id.node_id, item_level);
 181                     }
 182                 }
 183             }
 184             hir::ItemImpl(.., Some(_), _, ref impl_item_refs) => {
 185                 for impl_item_ref in impl_item_refs {
 186                     self.update(impl_item_ref.id.node_id, item_level);
 187                 }
 188             }
 189             hir::ItemTrait(.., ref trait_item_refs) => {
 190                 for trait_item_ref in trait_item_refs {
 191                     self.update(trait_item_ref.id.node_id, item_level);
 192                 }
 193             }
 194             hir::ItemStruct(ref def, _) | hir::ItemUnion(ref def, _) => {
 195                 if !def.is_struct() {
 196                     self.update(def.id(), item_level);
 197                 }
 198                 for field in def.fields() {
 199                     if field.vis == hir::Public {
 200                         self.update(field.id, item_level);
 201                     }
 202                 }
 203             }
 204             hir::ItemForeignMod(ref foreign_mod) => {
 205                 for foreign_item in &foreign_mod.items {
 206                     if foreign_item.vis == hir::Public {
 207                         self.update(foreign_item.id, item_level);
 208                     }
 209                 }
 210             }
 211             hir::ItemUse(..) | hir::ItemStatic(..) | hir::ItemConst(..) |
 212             hir::ItemGlobalAsm(..) | hir::ItemTy(..) | hir::ItemMod(..) | hir::ItemTraitAlias(..) |
 213             hir::ItemFn(..) | hir::ItemExternCrate(..) => {}
 214         }
 215
 216         // Mark all items in interfaces of reachable items as reachable
 217         match item.node {
 218             // The interface is empty
 219             hir::ItemExternCrate(..) => {}
 220             // All nested items are checked by visit_item
 221             hir::ItemMod(..) => {}
 222             // Re-exports are handled in visit_mod
 223             hir::ItemUse(..) => {}
 224             // The interface is empty
 225             hir::ItemGlobalAsm(..) => {}
 226             // Visit everything
 227             hir::ItemConst(..) | hir::ItemStatic(..) |
 228             hir::ItemFn(..) | hir::ItemTy(..) => {
 229                 if item_level.is_some() {
 230                     self.reach(item.id).generics().predicates().ty();
 231                 }
 232             }
 233             hir::ItemTrait(.., ref trait_item_refs) => {
 234                 if item_level.is_some() {
 235                     self.reach(item.id).generics().predicates();
 236
 237                     for trait_item_ref in trait_item_refs {
 238                         let mut reach = self.reach(trait_item_ref.id.node_id);
 239                         reach.generics().predicates();
 240
 241                         if trait_item_ref.kind == hir::AssociatedItemKind::Type &&
 242                            !trait_item_ref.defaultness.has_value() {
 243                             // No type to visit.
 244                         } else {
 245                             reach.ty();
 246                         }
 247                     }
 248                 }
 249             }
 250             hir::ItemTraitAlias(..) => {
 251                 if item_level.is_some() {
 252                     self.reach(item.id).generics().predicates();
 253                 }
 254             }
 255             // Visit everything except for private impl items
 256             hir::ItemImpl(.., ref trait_ref, _, ref impl_item_refs) => {
 257                 if item_level.is_some() {
 258                     self.reach(item.id).generics().predicates().impl_trait_ref();
 259
 260                     for impl_item_ref in impl_item_refs {
 261                         let id = impl_item_ref.id.node_id;
 262                         if trait_ref.is_some() || self.get(id).is_some() {
 263                             self.reach(id).generics().predicates().ty();
 264                         }
 265                     }
 266                 }
 267             }
 268
 269             // Visit everything, but enum variants have their own levels
 270             hir::ItemEnum(ref def, _) => {
 271                 if item_level.is_some() {
 272                     self.reach(item.id).generics().predicates();
 273                 }
 274                 for variant in &def.variants {
 275                     if self.get(variant.node.data.id()).is_some() {
 276                         for field in variant.node.data.fields() {
 277                             self.reach(field.id).ty();
 278                         }
 279                         // Corner case: if the variant is reachable, but its
 280                         // enum is not, make the enum reachable as well.
 281                         self.update(item.id, Some(AccessLevel::Reachable));
 282                     }
 283                 }
 284             }
 285             // Visit everything, but foreign items have their own levels
 286             hir::ItemForeignMod(ref foreign_mod) => {
 287                 for foreign_item in &foreign_mod.items {
 288                     if self.get(foreign_item.id).is_some() {
 289                         self.reach(foreign_item.id).generics().predicates().ty();
 290                     }
 291                 }
 292             }
 293             // Visit everything except for private fields
 294             hir::ItemStruct(ref struct_def, _) |
 295             hir::ItemUnion(ref struct_def, _) => {
 296                 if item_level.is_some() {
 297                     self.reach(item.id).generics().predicates();
 298                     for field in struct_def.fields() {
 299                         if self.get(field.id).is_some() {
 300                             self.reach(field.id).ty();
 301                         }
 302                     }
 303                 }
 304             }
 305         }
 306
 307         let orig_level = self.prev_level;
 308         self.prev_level = item_level;
 309
 310         intravisit::walk_item(self, item);
 311
 312         self.prev_level = orig_level;
 313     }
 314
 315     fn visit_block(&mut self, b: &'tcx hir::Block) {
 316         let orig_level = replace(&mut self.prev_level, None);
 317
 318         // Blocks can have public items, for example impls, but they always
 319         // start as completely private regardless of publicity of a function,
 320         // constant, type, field, etc. in which this block resides
 321         intravisit::walk_block(self, b);
 322
 323         self.prev_level = orig_level;
 324     }
 325
 326     fn visit_mod(&mut self, m: &'tcx hir::Mod, _sp: Span, id: ast::NodeId) {
 327         // This code is here instead of in visit_item so that the
 328         // crate module gets processed as well.
 329         if self.prev_level.is_some() {
 330             let def_id = self.tcx.hir.local_def_id(id);
 331             if let Some(exports) = self.tcx.module_exports(def_id) {
 332                 for export in exports.iter() {
 333                     if let Some(node_id) = self.tcx.hir.as_local_node_id(export.def.def_id()) {
 334                         if export.vis == ty::Visibility::Public {
 335                             self.update(node_id, Some(AccessLevel::Exported));
 336                         }
 337                     }
 338                 }
 339             }
 340         }
 341
 342         intravisit::walk_mod(self, m, id);
 343     }
 344
 345     fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef) {
 346         if md.legacy {
 347             self.update(md.id, Some(AccessLevel::Public));
 348             return
 349         }
 350
 351         let module_did = ty::DefIdTree::parent(self.tcx, self.tcx.hir.local_def_id(md.id)).unwrap();
 352         let mut module_id = self.tcx.hir.as_local_node_id(module_did).unwrap();
 353         let level = if md.vis == hir::Public { self.get(module_id) } else { None };
 354         let level = self.update(md.id, level);
 355         if level.is_none() {
 356             return
 357         }
 358
 359         loop {
 360             let module = if module_id == ast::CRATE_NODE_ID {
 361                 &self.tcx.hir.krate().module
 362             } else if let hir::ItemMod(ref module) = self.tcx.hir.expect_item(module_id).node {
 363                 module
 364             } else {
 365                 unreachable!()
 366             };
 367             for id in &module.item_ids {
 368                 self.update(id.id, level);
 369             }
 370             let def_id = self.tcx.hir.local_def_id(module_id);
 371             if let Some(exports) = self.tcx.module_exports(def_id) {
 372                 for export in exports.iter() {
 373                     if let Some(node_id) = self.tcx.hir.as_local_node_id(export.def.def_id()) {
 374                         self.update(node_id, level);
 375                     }
 376                 }
 377             }
 378
 379             if module_id == ast::CRATE_NODE_ID {
 380                 break
 381             }
 382             module_id = self.tcx.hir.get_parent_node(module_id);
 383         }
 384     }
 385
 386     fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
 387         if let hir::TyImplTraitExistential(..) = ty.node {
 388             if self.get(ty.id).is_some() {
 389                 // Reach the (potentially private) type and the API being exposed.
 390                 self.reach(ty.id).ty().predicates();
 391             }
 392         }
 393
 394         intravisit::walk_ty(self, ty);
 395     }
 396 }
 397
 398 impl<'b, 'a, 'tcx> ReachEverythingInTheInterfaceVisitor<'b, 'a, 'tcx> {
 399     fn generics(&mut self) -> &mut Self {
 400         for def in &self.ev.tcx.generics_of(self.item_def_id).types {
 401             if def.has_default {
 402                 self.ev.tcx.type_of(def.def_id).visit_with(self);
 403             }
 404         }
 405         self
 406     }
 407
 408     fn predicates(&mut self) -> &mut Self {
 409         let predicates = self.ev.tcx.predicates_of(self.item_def_id);
 410         for predicate in &predicates.predicates {
 411             predicate.visit_with(self);
 412             match predicate {
 413                 &ty::Predicate::Trait(poly_predicate) => {
 414                     self.check_trait_ref(poly_predicate.skip_binder().trait_ref);
 415                 },
 416                 &ty::Predicate::Projection(poly_predicate) => {
 417                     let tcx = self.ev.tcx;
 418                     self.check_trait_ref(
 419                         poly_predicate.skip_binder().projection_ty.trait_ref(tcx)
 420                     );
 421                 },
 422                 _ => (),
 423             };
 424         }
 425         self
 426     }
 427
 428     fn ty(&mut self) -> &mut Self {
 429         let ty = self.ev.tcx.type_of(self.item_def_id);
 430         ty.visit_with(self);
 431         if let ty::TyFnDef(def_id, _) = ty.sty {
 432             if def_id == self.item_def_id {
 433                 self.ev.tcx.fn_sig(def_id).visit_with(self);
 434             }
 435         }
 436         self
 437     }
 438
 439     fn impl_trait_ref(&mut self) -> &mut Self {
 440         if let Some(impl_trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
 441             self.check_trait_ref(impl_trait_ref);
 442             impl_trait_ref.super_visit_with(self);
 443         }
 444         self
 445     }
 446
 447     fn check_trait_ref(&mut self, trait_ref: ty::TraitRef<'tcx>) {
 448         if let Some(node_id) = self.ev.tcx.hir.as_local_node_id(trait_ref.def_id) {
 449             let item = self.ev.tcx.hir.expect_item(node_id);
 450             self.ev.update(item.id, Some(AccessLevel::Reachable));
 451         }
 452     }
 453 }
 454
 455 impl<'b, 'a, 'tcx> TypeVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'b, 'a, 'tcx> {
 456     fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
 457         let ty_def_id = match ty.sty {
 458             ty::TyAdt(adt, _) => Some(adt.did),
 459             ty::TyForeign(did) => Some(did),
 460             ty::TyDynamic(ref obj, ..) => obj.principal().map(|p| p.def_id()),
 461             ty::TyProjection(ref proj) => Some(proj.item_def_id),
 462             ty::TyFnDef(def_id, ..) |
 463             ty::TyClosure(def_id, ..) |
 464             ty::TyGenerator(def_id, ..) |
 465             ty::TyAnon(def_id, _) => Some(def_id),
 466             _ => None
 467         };
 468
 469         if let Some(def_id) = ty_def_id {
 470             if let Some(node_id) = self.ev.tcx.hir.as_local_node_id(def_id) {
 471                 self.ev.update(node_id, Some(AccessLevel::Reachable));
 472             }
 473         }
 474
 475         ty.super_visit_with(self)
 476     }
 477 }
 478
 479 //////////////////////////////////////////////////////////////////////////////////////
 480 /// Name privacy visitor, checks privacy and reports violations.
 481 /// Most of name privacy checks are performed during the main resolution phase,
 482 /// or later in type checking when field accesses and associated items are resolved.
 483 /// This pass performs remaining checks for fields in struct expressions and patterns.
 484 //////////////////////////////////////////////////////////////////////////////////////
 485
 486 struct NamePrivacyVisitor<'a, 'tcx: 'a> {
 487     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 488     tables: &'a ty::TypeckTables<'tcx>,
 489     current_item: ast::NodeId,
 490     empty_tables: &'a ty::TypeckTables<'tcx>,
 491 }
 492
 493 impl<'a, 'tcx> NamePrivacyVisitor<'a, 'tcx> {
 494     // Checks that a field is accessible.
 495     fn check_field(&mut self, span: Span, def: &'tcx ty::AdtDef, field: &'tcx ty::FieldDef) {
 496         let ident = Ident { ctxt: span.ctxt().modern(), ..keywords::Invalid.ident() };
 497         let def_id = self.tcx.adjust_ident(ident, def.did, self.current_item).1;
 498         if !def.is_enum() && !field.vis.is_accessible_from(def_id, self.tcx) {
 499             struct_span_err!(self.tcx.sess, span, E0451, "field `{}` of {} `{}` is private",
 500                              field.name, def.variant_descr(), self.tcx.item_path_str(def.did))
 501                 .span_label(span, format!("field `{}` is private", field.name))
 502                 .emit();
 503         }
 504     }
 505 }
 506
 507 // Set the correct TypeckTables for the given `item_id` (or an empty table if
 508 // there is no TypeckTables for the item).
 509 fn update_tables<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 510                            item_id: ast::NodeId,
 511                            tables: &mut &'a ty::TypeckTables<'tcx>,
 512                            empty_tables: &'a ty::TypeckTables<'tcx>)
 513                            -> &'a ty::TypeckTables<'tcx> {
 514     let def_id = tcx.hir.local_def_id(item_id);
 515
 516     if tcx.has_typeck_tables(def_id) {
 517         replace(tables, tcx.typeck_tables_of(def_id))
 518     } else {
 519         replace(tables, empty_tables)
 520     }
 521 }
 522
 523 impl<'a, 'tcx> Visitor<'tcx> for NamePrivacyVisitor<'a, 'tcx> {
 524     /// We want to visit items in the context of their containing
 525     /// module and so forth, so supply a crate for doing a deep walk.
 526     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 527         NestedVisitorMap::All(&self.tcx.hir)
 528     }
 529
 530     fn visit_nested_body(&mut self, body: hir::BodyId) {
 531         let orig_tables = replace(&mut self.tables, self.tcx.body_tables(body));
 532         let body = self.tcx.hir.body(body);
 533         self.visit_body(body);
 534         self.tables = orig_tables;
 535     }
 536
 537     fn visit_item(&mut self, item: &'tcx hir::Item) {
 538         let orig_current_item = replace(&mut self.current_item, item.id);
 539         let orig_tables = update_tables(self.tcx, item.id, &mut self.tables, self.empty_tables);
 540         intravisit::walk_item(self, item);
 541         self.current_item = orig_current_item;
 542         self.tables = orig_tables;
 543     }
 544
 545     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) {
 546         let orig_tables = update_tables(self.tcx, ti.id, &mut self.tables, self.empty_tables);
 547         intravisit::walk_trait_item(self, ti);
 548         self.tables = orig_tables;
 549     }
 550
 551     fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
 552         let orig_tables = update_tables(self.tcx, ii.id, &mut self.tables, self.empty_tables);
 553         intravisit::walk_impl_item(self, ii);
 554         self.tables = orig_tables;
 555     }
 556
 557     fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
 558         match expr.node {
 559             hir::ExprStruct(ref qpath, ref fields, ref base) => {
 560                 let def = self.tables.qpath_def(qpath, expr.hir_id);
 561                 let adt = self.tables.expr_ty(expr).ty_adt_def().unwrap();
 562                 let variant = adt.variant_of_def(def);
 563                 if let Some(ref base) = *base {
 564                     // If the expression uses FRU we need to make sure all the unmentioned fields
 565                     // are checked for privacy (RFC 736). Rather than computing the set of
 566                     // unmentioned fields, just check them all.
 567                     for variant_field in &variant.fields {
 568                         let field = fields.iter().find(|f| f.name.node == variant_field.name);
 569                         let span = if let Some(f) = field { f.span } else { base.span };
 570                         self.check_field(span, adt, variant_field);
 571                     }
 572                 } else {
 573                     for field in fields {
 574                         self.check_field(field.span, adt, variant.field_named(field.name.node));
 575                     }
 576                 }
 577             }
 578             _ => {}
 579         }
 580
 581         intravisit::walk_expr(self, expr);
 582     }
 583
 584     fn visit_pat(&mut self, pat: &'tcx hir::Pat) {
 585         match pat.node {
 586             PatKind::Struct(ref qpath, ref fields, _) => {
 587                 let def = self.tables.qpath_def(qpath, pat.hir_id);
 588                 let adt = self.tables.pat_ty(pat).ty_adt_def().unwrap();
 589                 let variant = adt.variant_of_def(def);
 590                 for field in fields {
 591                     self.check_field(field.span, adt, variant.field_named(field.node.name));
 592                 }
 593             }
 594             _ => {}
 595         }
 596
 597         intravisit::walk_pat(self, pat);
 598     }
 599 }
 600
 601 ////////////////////////////////////////////////////////////////////////////////////////////
 602 /// Type privacy visitor, checks types for privacy and reports violations.
 603 /// Both explicitly written types and inferred types of expressions and patters are checked.
 604 /// Checks are performed on "semantic" types regardless of names and their hygiene.
 605 ////////////////////////////////////////////////////////////////////////////////////////////
 606
 607 struct TypePrivacyVisitor<'a, 'tcx: 'a> {
 608     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 609     tables: &'a ty::TypeckTables<'tcx>,
 610     current_item: DefId,
 611     in_body: bool,
 612     span: Span,
 613     empty_tables: &'a ty::TypeckTables<'tcx>,
 614 }
 615
 616 impl<'a, 'tcx> TypePrivacyVisitor<'a, 'tcx> {
 617     fn def_id_visibility(&self, did: DefId) -> ty::Visibility {
 618         match self.tcx.hir.as_local_node_id(did) {
 619             Some(node_id) => {
 620                 let vis = match self.tcx.hir.get(node_id) {
 621                     hir::map::NodeItem(item) => &item.vis,
 622                     hir::map::NodeForeignItem(foreign_item) => &foreign_item.vis,
 623                     hir::map::NodeImplItem(impl_item) => &impl_item.vis,
 624                     hir::map::NodeTraitItem(..) |
 625                     hir::map::NodeVariant(..) => {
 626                         return self.def_id_visibility(self.tcx.hir.get_parent_did(node_id));
 627                     }
 628                     hir::map::NodeStructCtor(vdata) => {
 629                         let struct_node_id = self.tcx.hir.get_parent(node_id);
 630                         let struct_vis = match self.tcx.hir.get(struct_node_id) {
 631                             hir::map::NodeItem(item) => &item.vis,
 632                             node => bug!("unexpected node kind: {:?}", node),
 633                         };
 634                         let mut ctor_vis
 635                             = ty::Visibility::from_hir(struct_vis, struct_node_id, self.tcx);
 636                         for field in vdata.fields() {
 637                             let field_vis = ty::Visibility::from_hir(&field.vis, node_id, self.tcx);
 638                             if ctor_vis.is_at_least(field_vis, self.tcx) {
 639                                 ctor_vis = field_vis;
 640                             }
 641                         }
 642
 643                         // If the structure is marked as non_exhaustive then lower the
 644                         // visibility to within the crate.
 645                         let struct_def_id = self.tcx.hir.get_parent_did(node_id);
 646                         let adt_def = self.tcx.adt_def(struct_def_id);
 647                         if adt_def.is_non_exhaustive() && ctor_vis == ty::Visibility::Public {
 648                             ctor_vis = ty::Visibility::Restricted(
 649                                 DefId::local(CRATE_DEF_INDEX));
 650                         }
 651
 652                         return ctor_vis;
 653                     }
 654                     node => bug!("unexpected node kind: {:?}", node)
 655                 };
 656                 ty::Visibility::from_hir(vis, node_id, self.tcx)
 657             }
 658             None => self.tcx.visibility(did),
 659         }
 660     }
 661
 662     fn item_is_accessible(&self, did: DefId) -> bool {
 663         self.def_id_visibility(did).is_accessible_from(self.current_item, self.tcx)
 664     }
 665
 666     // Take node ID of an expression or pattern and check its type for privacy.
 667     fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
 668         self.span = span;
 669         if self.tables.node_id_to_type(id).visit_with(self) {
 670             return true;
 671         }
 672         if self.tables.node_substs(id).visit_with(self) {
 673             return true;
 674         }
 675         if let Some(adjustments) = self.tables.adjustments().get(id) {
 676             for adjustment in adjustments {
 677                 if adjustment.target.visit_with(self) {
 678                     return true;
 679                 }
 680             }
 681         }
 682         false
 683     }
 684
 685     fn check_trait_ref(&mut self, trait_ref: ty::TraitRef<'tcx>) -> bool {
 686         if !self.item_is_accessible(trait_ref.def_id) {
 687             let msg = format!("trait `{}` is private", trait_ref);
 688             self.tcx.sess.span_err(self.span, &msg);
 689             return true;
 690         }
 691
 692         trait_ref.super_visit_with(self)
 693     }
 694 }
 695
 696 impl<'a, 'tcx> Visitor<'tcx> for TypePrivacyVisitor<'a, 'tcx> {
 697     /// We want to visit items in the context of their containing
 698     /// module and so forth, so supply a crate for doing a deep walk.
 699     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 700         NestedVisitorMap::All(&self.tcx.hir)
 701     }
 702
 703     fn visit_nested_body(&mut self, body: hir::BodyId) {
 704         let orig_tables = replace(&mut self.tables, self.tcx.body_tables(body));
 705         let orig_in_body = replace(&mut self.in_body, true);
 706         let body = self.tcx.hir.body(body);
 707         self.visit_body(body);
 708         self.tables = orig_tables;
 709         self.in_body = orig_in_body;
 710     }
 711
 712     fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty) {
 713         self.span = hir_ty.span;
 714         if self.in_body {
 715             // Types in bodies.
 716             if self.tables.node_id_to_type(hir_ty.hir_id).visit_with(self) {
 717                 return;
 718             }
 719         } else {
 720             // Types in signatures.
 721             // FIXME: This is very ineffective. Ideally each HIR type should be converted
 722             // into a semantic type only once and the result should be cached somehow.
 723             if rustc_typeck::hir_ty_to_ty(self.tcx, hir_ty).visit_with(self) {
 724                 return;
 725             }
 726         }
 727
 728         intravisit::walk_ty(self, hir_ty);
 729     }
 730
 731     fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef) {
 732         self.span = trait_ref.path.span;
 733         if !self.in_body {
 734             // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
 735             // The traits' privacy in bodies is already checked as a part of trait object types.
 736             let (principal, projections) =
 737                 rustc_typeck::hir_trait_to_predicates(self.tcx, trait_ref);
 738             if self.check_trait_ref(*principal.skip_binder()) {
 739                 return;
 740             }
 741             for poly_predicate in projections {
 742                 let tcx = self.tcx;
 743                 if self.check_trait_ref(poly_predicate.skip_binder().projection_ty.trait_ref(tcx)) {
 744                     return;
 745                 }
 746             }
 747         }
 748
 749         intravisit::walk_trait_ref(self, trait_ref);
 750     }
 751
 752     // Check types of expressions
 753     fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
 754         if self.check_expr_pat_type(expr.hir_id, expr.span) {
 755             // Do not check nested expressions if the error already happened.
 756             return;
 757         }
 758         match expr.node {
 759             hir::ExprAssign(.., ref rhs) | hir::ExprMatch(ref rhs, ..) => {
 760                 // Do not report duplicate errors for `x = y` and `match x { ... }`.
 761                 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
 762                     return;
 763                 }
 764             }
 765             hir::ExprMethodCall(_, span, _) => {
 766                 // Method calls have to be checked specially.
 767                 let def_id = self.tables.type_dependent_defs()[expr.hir_id].def_id();
 768                 self.span = span;
 769                 if self.tcx.type_of(def_id).visit_with(self) {
 770                     return;
 771                 }
 772             }
 773             _ => {}
 774         }
 775
 776         intravisit::walk_expr(self, expr);
 777     }
 778
 779     // Prohibit access to associated items with insufficient nominal visibility.
 780     //
 781     // Additionally, until better reachability analysis for macros 2.0 is available,
 782     // we prohibit access to private statics from other crates, this allows to give
 783     // more code internal visibility at link time. (Access to private functions
 784     // is already prohibited by type privacy for funciton types.)
 785     fn visit_qpath(&mut self, qpath: &'tcx hir::QPath, id: ast::NodeId, span: Span) {
 786         let def = match *qpath {
 787             hir::QPath::Resolved(_, ref path) => match path.def {
 788                 Def::Method(..) | Def::AssociatedConst(..) |
 789                 Def::AssociatedTy(..) | Def::Static(..) => Some(path.def),
 790                 _ => None,
 791             }
 792             hir::QPath::TypeRelative(..) => {
 793                 let hir_id = self.tcx.hir.node_to_hir_id(id);
 794                 self.tables.type_dependent_defs().get(hir_id).cloned()
 795             }
 796         };
 797         if let Some(def) = def {
 798             let def_id = def.def_id();
 799             let is_local_static = if let Def::Static(..) = def { def_id.is_local() } else { false };
 800             if !self.item_is_accessible(def_id) && !is_local_static {
 801                 let name = match *qpath {
 802                     hir::QPath::Resolved(_, ref path) => format!("{}", path),
 803                     hir::QPath::TypeRelative(_, ref segment) => segment.name.to_string(),
 804                 };
 805                 let msg = format!("{} `{}` is private", def.kind_name(), name);
 806                 self.tcx.sess.span_err(span, &msg);
 807                 return;
 808             }
 809         }
 810
 811         intravisit::walk_qpath(self, qpath, id, span);
 812     }
 813
 814     // Check types of patterns
 815     fn visit_pat(&mut self, pattern: &'tcx hir::Pat) {
 816         if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
 817             // Do not check nested patterns if the error already happened.
 818             return;
 819         }
 820
 821         intravisit::walk_pat(self, pattern);
 822     }
 823
 824     fn visit_local(&mut self, local: &'tcx hir::Local) {
 825         if let Some(ref init) = local.init {
 826             if self.check_expr_pat_type(init.hir_id, init.span) {
 827                 // Do not report duplicate errors for `let x = y`.
 828                 return;
 829             }
 830         }
 831
 832         intravisit::walk_local(self, local);
 833     }
 834
 835     // Check types in item interfaces
 836     fn visit_item(&mut self, item: &'tcx hir::Item) {
 837         let orig_current_item = self.current_item;
 838         let orig_tables = update_tables(self.tcx,
 839                                         item.id,
 840                                         &mut self.tables,
 841                                         self.empty_tables);
 842         let orig_in_body = replace(&mut self.in_body, false);
 843         self.current_item = self.tcx.hir.local_def_id(item.id);
 844         intravisit::walk_item(self, item);
 845         self.tables = orig_tables;
 846         self.in_body = orig_in_body;
 847         self.current_item = orig_current_item;
 848     }
 849
 850     fn visit_trait_item(&mut self, ti: &'tcx hir::TraitItem) {
 851         let orig_tables = update_tables(self.tcx, ti.id, &mut self.tables, self.empty_tables);
 852         intravisit::walk_trait_item(self, ti);
 853         self.tables = orig_tables;
 854     }
 855
 856     fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem) {
 857         let orig_tables = update_tables(self.tcx, ii.id, &mut self.tables, self.empty_tables);
 858         intravisit::walk_impl_item(self, ii);
 859         self.tables = orig_tables;
 860     }
 861 }
 862
 863 impl<'a, 'tcx> TypeVisitor<'tcx> for TypePrivacyVisitor<'a, 'tcx> {
 864     fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
 865         match ty.sty {
 866             ty::TyAdt(&ty::AdtDef { did: def_id, .. }, ..) |
 867             ty::TyFnDef(def_id, ..) |
 868             ty::TyForeign(def_id) => {
 869                 if !self.item_is_accessible(def_id) {
 870                     let msg = format!("type `{}` is private", ty);
 871                     self.tcx.sess.span_err(self.span, &msg);
 872                     return true;
 873                 }
 874                 if let ty::TyFnDef(..) = ty.sty {
 875                     if self.tcx.fn_sig(def_id).visit_with(self) {
 876                         return true;
 877                     }
 878                 }
 879                 // Inherent static methods don't have self type in substs,
 880                 // we have to check it additionally.
 881                 if let Some(assoc_item) = self.tcx.opt_associated_item(def_id) {
 882                     if let ty::ImplContainer(impl_def_id) = assoc_item.container {
 883                         if self.tcx.type_of(impl_def_id).visit_with(self) {
 884                             return true;
 885                         }
 886                     }
 887                 }
 888             }
 889             ty::TyDynamic(ref predicates, ..) => {
 890                 let is_private = predicates.skip_binder().iter().any(|predicate| {
 891                     let def_id = match *predicate {
 892                         ty::ExistentialPredicate::Trait(trait_ref) => trait_ref.def_id,
 893                         ty::ExistentialPredicate::Projection(proj) =>
 894                             proj.trait_ref(self.tcx).def_id,
 895                         ty::ExistentialPredicate::AutoTrait(def_id) => def_id,
 896                     };
 897                     !self.item_is_accessible(def_id)
 898                 });
 899                 if is_private {
 900                     let msg = format!("type `{}` is private", ty);
 901                     self.tcx.sess.span_err(self.span, &msg);
 902                     return true;
 903                 }
 904             }
 905             ty::TyProjection(ref proj) => {
 906                 let tcx = self.tcx;
 907                 if self.check_trait_ref(proj.trait_ref(tcx)) {
 908                     return true;
 909                 }
 910             }
 911             ty::TyAnon(def_id, ..) => {
 912                 for predicate in &self.tcx.predicates_of(def_id).predicates {
 913                     let trait_ref = match *predicate {
 914                         ty::Predicate::Trait(ref poly_trait_predicate) => {
 915                             Some(poly_trait_predicate.skip_binder().trait_ref)
 916                         }
 917                         ty::Predicate::Projection(ref poly_projection_predicate) => {
 918                             if poly_projection_predicate.skip_binder().ty.visit_with(self) {
 919                                 return true;
 920                             }
 921                             Some(poly_projection_predicate.skip_binder()
 922                                                           .projection_ty.trait_ref(self.tcx))
 923                         }
 924                         ty::Predicate::TypeOutlives(..) => None,
 925                         _ => bug!("unexpected predicate: {:?}", predicate),
 926                     };
 927                     if let Some(trait_ref) = trait_ref {
 928                         if !self.item_is_accessible(trait_ref.def_id) {
 929                             let msg = format!("trait `{}` is private", trait_ref);
 930                             self.tcx.sess.span_err(self.span, &msg);
 931                             return true;
 932                         }
 933                         // `Self` here is the same `TyAnon`, so skip it to avoid infinite recursion
 934                         for subst in trait_ref.substs.iter().skip(1) {
 935                             if subst.visit_with(self) {
 936                                 return true;
 937                             }
 938                         }
 939                     }
 940                 }
 941             }
 942             _ => {}
 943         }
 944
 945         ty.super_visit_with(self)
 946     }
 947 }
 948
 949 ///////////////////////////////////////////////////////////////////////////////
 950 /// Obsolete visitors for checking for private items in public interfaces.
 951 /// These visitors are supposed to be kept in frozen state and produce an
 952 /// "old error node set". For backward compatibility the new visitor reports
 953 /// warnings instead of hard errors when the erroneous node is not in this old set.
 954 ///////////////////////////////////////////////////////////////////////////////
 955
 956 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx: 'a> {
 957     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 958     access_levels: &'a AccessLevels,
 959     in_variant: bool,
 960     // set of errors produced by this obsolete visitor
 961     old_error_set: NodeSet,
 962 }
 963
 964 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b: 'a, 'tcx: 'b> {
 965     inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
 966     /// whether the type refers to private types.
 967     contains_private: bool,
 968     /// whether we've recurred at all (i.e. if we're pointing at the
 969     /// first type on which visit_ty was called).
 970     at_outer_type: bool,
 971     // whether that first type is a public path.
 972     outer_type_is_public_path: bool,
 973 }
 974
 975 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
 976     fn path_is_private_type(&self, path: &hir::Path) -> bool {
 977         let did = match path.def {
 978             Def::PrimTy(..) | Def::SelfTy(..) => return false,
 979             def => def.def_id(),
 980         };
 981
 982         // A path can only be private if:
 983         // it's in this crate...
 984         if let Some(node_id) = self.tcx.hir.as_local_node_id(did) {
 985             // .. and it corresponds to a private type in the AST (this returns
 986             // None for type parameters)
 987             match self.tcx.hir.find(node_id) {
 988                 Some(hir::map::NodeItem(ref item)) => item.vis != hir::Public,
 989                 Some(_) | None => false,
 990             }
 991         } else {
 992             return false
 993         }
 994     }
 995
 996     fn trait_is_public(&self, trait_id: ast::NodeId) -> bool {
 997         // FIXME: this would preferably be using `exported_items`, but all
 998         // traits are exported currently (see `EmbargoVisitor.exported_trait`)
 999         self.access_levels.is_public(trait_id)
1000     }
1001
1002     fn check_ty_param_bound(&mut self,
1003                             ty_param_bound: &hir::TyParamBound) {
1004         if let hir::TraitTyParamBound(ref trait_ref, _) = *ty_param_bound {
1005             if self.path_is_private_type(&trait_ref.trait_ref.path) {
1006                 self.old_error_set.insert(trait_ref.trait_ref.ref_id);
1007             }
1008         }
1009     }
1010
1011     fn item_is_public(&self, id: &ast::NodeId, vis: &hir::Visibility) -> bool {
1012         self.access_levels.is_reachable(*id) || *vis == hir::Public
1013     }
1014 }
1015
1016 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1017     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v> {
1018         NestedVisitorMap::None
1019     }
1020
1021     fn visit_ty(&mut self, ty: &hir::Ty) {
1022         if let hir::TyPath(hir::QPath::Resolved(_, ref path)) = ty.node {
1023             if self.inner.path_is_private_type(path) {
1024                 self.contains_private = true;
1025                 // found what we're looking for so let's stop
1026                 // working.
1027                 return
1028             }
1029         }
1030         if let hir::TyPath(_) = ty.node {
1031             if self.at_outer_type {
1032                 self.outer_type_is_public_path = true;
1033             }
1034         }
1035         self.at_outer_type = false;
1036         intravisit::walk_ty(self, ty)
1037     }
1038
1039     // don't want to recurse into [, .. expr]
1040     fn visit_expr(&mut self, _: &hir::Expr) {}
1041 }
1042
1043 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1044     /// We want to visit items in the context of their containing
1045     /// module and so forth, so supply a crate for doing a deep walk.
1046     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
1047         NestedVisitorMap::All(&self.tcx.hir)
1048     }
1049
1050     fn visit_item(&mut self, item: &'tcx hir::Item) {
1051         match item.node {
1052             // contents of a private mod can be re-exported, so we need
1053             // to check internals.
1054             hir::ItemMod(_) => {}
1055
1056             // An `extern {}` doesn't introduce a new privacy
1057             // namespace (the contents have their own privacies).
1058             hir::ItemForeignMod(_) => {}
1059
1060             hir::ItemTrait(.., ref bounds, _) => {
1061                 if !self.trait_is_public(item.id) {
1062                     return
1063                 }
1064
1065                 for bound in bounds.iter() {
1066                     self.check_ty_param_bound(bound)
1067                 }
1068             }
1069
1070             // impls need some special handling to try to offer useful
1071             // error messages without (too many) false positives
1072             // (i.e. we could just return here to not check them at
1073             // all, or some worse estimation of whether an impl is
1074             // publicly visible).
1075             hir::ItemImpl(.., ref g, ref trait_ref, ref self_, ref impl_item_refs) => {
1076                 // `impl [... for] Private` is never visible.
1077                 let self_contains_private;
1078                 // impl [... for] Public<...>, but not `impl [... for]
1079                 // Vec<Public>` or `(Public,)` etc.
1080                 let self_is_public_path;
1081
1082                 // check the properties of the Self type:
1083                 {
1084                     let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1085                         inner: self,
1086                         contains_private: false,
1087                         at_outer_type: true,
1088                         outer_type_is_public_path: false,
1089                     };
1090                     visitor.visit_ty(&self_);
1091                     self_contains_private = visitor.contains_private;
1092                     self_is_public_path = visitor.outer_type_is_public_path;
1093                 }
1094
1095                 // miscellaneous info about the impl
1096
1097                 // `true` iff this is `impl Private for ...`.
1098                 let not_private_trait =
1099                     trait_ref.as_ref().map_or(true, // no trait counts as public trait
1100                                               |tr| {
1101                         let did = tr.path.def.def_id();
1102
1103                         if let Some(node_id) = self.tcx.hir.as_local_node_id(did) {
1104                             self.trait_is_public(node_id)
1105                         } else {
1106                             true // external traits must be public
1107                         }
1108                     });
1109
1110                 // `true` iff this is a trait impl or at least one method is public.
1111                 //
1112                 // `impl Public { $( fn ...() {} )* }` is not visible.
1113                 //
1114                 // This is required over just using the methods' privacy
1115                 // directly because we might have `impl<T: Foo<Private>> ...`,
1116                 // and we shouldn't warn about the generics if all the methods
1117                 // are private (because `T` won't be visible externally).
1118                 let trait_or_some_public_method =
1119                     trait_ref.is_some() ||
1120                     impl_item_refs.iter()
1121                                  .any(|impl_item_ref| {
1122                                      let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1123                                      match impl_item.node {
1124                                          hir::ImplItemKind::Const(..) |
1125                                          hir::ImplItemKind::Method(..) => {
1126                                              self.access_levels.is_reachable(impl_item.id)
1127                                          }
1128                                          hir::ImplItemKind::Type(_) => false,
1129                                      }
1130                                  });
1131
1132                 if !self_contains_private &&
1133                         not_private_trait &&
1134                         trait_or_some_public_method {
1135
1136                     intravisit::walk_generics(self, g);
1137
1138                     match *trait_ref {
1139                         None => {
1140                             for impl_item_ref in impl_item_refs {
1141                                 // This is where we choose whether to walk down
1142                                 // further into the impl to check its items. We
1143                                 // should only walk into public items so that we
1144                                 // don't erroneously report errors for private
1145                                 // types in private items.
1146                                 let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1147                                 match impl_item.node {
1148                                     hir::ImplItemKind::Const(..) |
1149                                     hir::ImplItemKind::Method(..)
1150                                         if self.item_is_public(&impl_item.id, &impl_item.vis) =>
1151                                     {
1152                                         intravisit::walk_impl_item(self, impl_item)
1153                                     }
1154                                     hir::ImplItemKind::Type(..) => {
1155                                         intravisit::walk_impl_item(self, impl_item)
1156                                     }
1157                                     _ => {}
1158                                 }
1159                             }
1160                         }
1161                         Some(ref tr) => {
1162                             // Any private types in a trait impl fall into three
1163                             // categories.
1164                             // 1. mentioned in the trait definition
1165                             // 2. mentioned in the type params/generics
1166                             // 3. mentioned in the associated types of the impl
1167                             //
1168                             // Those in 1. can only occur if the trait is in
1169                             // this crate and will've been warned about on the
1170                             // trait definition (there's no need to warn twice
1171                             // so we don't check the methods).
1172                             //
1173                             // Those in 2. are warned via walk_generics and this
1174                             // call here.
1175                             intravisit::walk_path(self, &tr.path);
1176
1177                             // Those in 3. are warned with this call.
1178                             for impl_item_ref in impl_item_refs {
1179                                 let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1180                                 if let hir::ImplItemKind::Type(ref ty) = impl_item.node {
1181                                     self.visit_ty(ty);
1182                                 }
1183                             }
1184                         }
1185                     }
1186                 } else if trait_ref.is_none() && self_is_public_path {
1187                     // impl Public<Private> { ... }. Any public static
1188                     // methods will be visible as `Public::foo`.
1189                     let mut found_pub_static = false;
1190                     for impl_item_ref in impl_item_refs {
1191                         if self.item_is_public(&impl_item_ref.id.node_id, &impl_item_ref.vis) {
1192                             let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1193                             match impl_item_ref.kind {
1194                                 hir::AssociatedItemKind::Const => {
1195                                     found_pub_static = true;
1196                                     intravisit::walk_impl_item(self, impl_item);
1197                                 }
1198                                 hir::AssociatedItemKind::Method { has_self: false } => {
1199                                     found_pub_static = true;
1200                                     intravisit::walk_impl_item(self, impl_item);
1201                                 }
1202                                 _ => {}
1203                             }
1204                         }
1205                     }
1206                     if found_pub_static {
1207                         intravisit::walk_generics(self, g)
1208                     }
1209                 }
1210                 return
1211             }
1212
1213             // `type ... = ...;` can contain private types, because
1214             // we're introducing a new name.
1215             hir::ItemTy(..) => return,
1216
1217             // not at all public, so we don't care
1218             _ if !self.item_is_public(&item.id, &item.vis) => {
1219                 return;
1220             }
1221
1222             _ => {}
1223         }
1224
1225         // We've carefully constructed it so that if we're here, then
1226         // any `visit_ty`'s will be called on things that are in
1227         // public signatures, i.e. things that we're interested in for
1228         // this visitor.
1229         intravisit::walk_item(self, item);
1230     }
1231
1232     fn visit_generics(&mut self, generics: &'tcx hir::Generics) {
1233         for ty_param in generics.ty_params() {
1234             for bound in ty_param.bounds.iter() {
1235                 self.check_ty_param_bound(bound)
1236             }
1237         }
1238         for predicate in &generics.where_clause.predicates {
1239             match predicate {
1240                 &hir::WherePredicate::BoundPredicate(ref bound_pred) => {
1241                     for bound in bound_pred.bounds.iter() {
1242                         self.check_ty_param_bound(bound)
1243                     }
1244                 }
1245                 &hir::WherePredicate::RegionPredicate(_) => {}
1246                 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
1247                     self.visit_ty(&eq_pred.rhs_ty);
1248                 }
1249             }
1250         }
1251     }
1252
1253     fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem) {
1254         if self.access_levels.is_reachable(item.id) {
1255             intravisit::walk_foreign_item(self, item)
1256         }
1257     }
1258
1259     fn visit_ty(&mut self, t: &'tcx hir::Ty) {
1260         if let hir::TyPath(hir::QPath::Resolved(_, ref path)) = t.node {
1261             if self.path_is_private_type(path) {
1262                 self.old_error_set.insert(t.id);
1263             }
1264         }
1265         intravisit::walk_ty(self, t)
1266     }
1267
1268     fn visit_variant(&mut self,
1269                      v: &'tcx hir::Variant,
1270                      g: &'tcx hir::Generics,
1271                      item_id: ast::NodeId) {
1272         if self.access_levels.is_reachable(v.node.data.id()) {
1273             self.in_variant = true;
1274             intravisit::walk_variant(self, v, g, item_id);
1275             self.in_variant = false;
1276         }
1277     }
1278
1279     fn visit_struct_field(&mut self, s: &'tcx hir::StructField) {
1280         if s.vis == hir::Public || self.in_variant {
1281             intravisit::walk_struct_field(self, s);
1282         }
1283     }
1284
1285     // we don't need to introspect into these at all: an
1286     // expression/block context can't possibly contain exported things.
1287     // (Making them no-ops stops us from traversing the whole AST without
1288     // having to be super careful about our `walk_...` calls above.)
1289     fn visit_block(&mut self, _: &'tcx hir::Block) {}
1290     fn visit_expr(&mut self, _: &'tcx hir::Expr) {}
1291 }
1292
1293 ///////////////////////////////////////////////////////////////////////////////
1294 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1295 /// finds any private components in it.
1296 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1297 /// and traits in public interfaces.
1298 ///////////////////////////////////////////////////////////////////////////////
1299
1300 struct SearchInterfaceForPrivateItemsVisitor<'a, 'tcx: 'a> {
1301     tcx: TyCtxt<'a, 'tcx, 'tcx>,
1302     item_def_id: DefId,
1303     span: Span,
1304     /// The visitor checks that each component type is at least this visible
1305     required_visibility: ty::Visibility,
1306     /// The visibility of the least visible component that has been visited
1307     min_visibility: ty::Visibility,
1308     has_pub_restricted: bool,
1309     has_old_errors: bool,
1310     in_assoc_ty: bool,
1311 }
1312
1313 impl<'a, 'tcx: 'a> SearchInterfaceForPrivateItemsVisitor<'a, 'tcx> {
1314     fn generics(&mut self) -> &mut Self {
1315         for def in &self.tcx.generics_of(self.item_def_id).types {
1316             if def.has_default {
1317                 self.tcx.type_of(def.def_id).visit_with(self);
1318             }
1319         }
1320         self
1321     }
1322
1323     fn predicates(&mut self) -> &mut Self {
1324         let predicates = self.tcx.predicates_of(self.item_def_id);
1325         for predicate in &predicates.predicates {
1326             predicate.visit_with(self);
1327             match predicate {
1328                 &ty::Predicate::Trait(poly_predicate) => {
1329                     self.check_trait_ref(poly_predicate.skip_binder().trait_ref);
1330                 },
1331                 &ty::Predicate::Projection(poly_predicate) => {
1332                     let tcx = self.tcx;
1333                     self.check_trait_ref(
1334                         poly_predicate.skip_binder().projection_ty.trait_ref(tcx)
1335                     );
1336                 },
1337                 _ => (),
1338             };
1339         }
1340         self
1341     }
1342
1343     fn ty(&mut self) -> &mut Self {
1344         let ty = self.tcx.type_of(self.item_def_id);
1345         ty.visit_with(self);
1346         if let ty::TyFnDef(def_id, _) = ty.sty {
1347             if def_id == self.item_def_id {
1348                 self.tcx.fn_sig(def_id).visit_with(self);
1349             }
1350         }
1351         self
1352     }
1353
1354     fn impl_trait_ref(&mut self) -> &mut Self {
1355         if let Some(impl_trait_ref) = self.tcx.impl_trait_ref(self.item_def_id) {
1356             self.check_trait_ref(impl_trait_ref);
1357             impl_trait_ref.super_visit_with(self);
1358         }
1359         self
1360     }
1361
1362     fn check_trait_ref(&mut self, trait_ref: ty::TraitRef<'tcx>) {
1363         // Non-local means public (private items can't leave their crate, modulo bugs)
1364         if let Some(node_id) = self.tcx.hir.as_local_node_id(trait_ref.def_id) {
1365             let item = self.tcx.hir.expect_item(node_id);
1366             let vis = ty::Visibility::from_hir(&item.vis, node_id, self.tcx);
1367             if !vis.is_at_least(self.min_visibility, self.tcx) {
1368                 self.min_visibility = vis;
1369             }
1370             if !vis.is_at_least(self.required_visibility, self.tcx) {
1371                 if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1372                     struct_span_err!(self.tcx.sess, self.span, E0445,
1373                                      "private trait `{}` in public interface", trait_ref)
1374                         .span_label(self.span, format!(
1375                                     "can't leak private trait"))
1376                         .emit();
1377                 } else {
1378                     self.tcx.lint_node(lint::builtin::PRIVATE_IN_PUBLIC,
1379                                        node_id,
1380                                        self.span,
1381                                        &format!("private trait `{}` in public \
1382                                                  interface (error E0445)", trait_ref));
1383                 }
1384             }
1385         }
1386     }
1387 }
1388
1389 impl<'a, 'tcx: 'a> TypeVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'a, 'tcx> {
1390     fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
1391         let ty_def_id = match ty.sty {
1392             ty::TyAdt(adt, _) => Some(adt.did),
1393             ty::TyForeign(did) => Some(did),
1394             ty::TyDynamic(ref obj, ..) => obj.principal().map(|p| p.def_id()),
1395             ty::TyProjection(ref proj) => {
1396                 if self.required_visibility == ty::Visibility::Invisible {
1397                     // Conservatively approximate the whole type alias as public without
1398                     // recursing into its components when determining impl publicity.
1399                     // For example, `impl <Type as Trait>::Alias {...}` may be a public impl
1400                     // even if both `Type` and `Trait` are private.
1401                     // Ideally, associated types should be substituted in the same way as
1402                     // free type aliases, but this isn't done yet.
1403                     return false;
1404                 }
1405                 let trait_ref = proj.trait_ref(self.tcx);
1406                 Some(trait_ref.def_id)
1407             }
1408             _ => None
1409         };
1410
1411         if let Some(def_id) = ty_def_id {
1412             // Non-local means public (private items can't leave their crate, modulo bugs)
1413             if let Some(node_id) = self.tcx.hir.as_local_node_id(def_id) {
1414                 let vis = match self.tcx.hir.find(node_id) {
1415                     Some(hir::map::NodeItem(item)) => &item.vis,
1416                     Some(hir::map::NodeForeignItem(item)) => &item.vis,
1417                     _ => bug!("expected item of foreign item"),
1418                 };
1419
1420                 let vis = ty::Visibility::from_hir(vis, node_id, self.tcx);
1421
1422                 if !vis.is_at_least(self.min_visibility, self.tcx) {
1423                     self.min_visibility = vis;
1424                 }
1425                 if !vis.is_at_least(self.required_visibility, self.tcx) {
1426                     if self.has_pub_restricted || self.has_old_errors || self.in_assoc_ty {
1427                         let mut err = struct_span_err!(self.tcx.sess, self.span, E0446,
1428                             "private type `{}` in public interface", ty);
1429                         err.span_label(self.span, "can't leak private type");
1430                         err.emit();
1431                     } else {
1432                         self.tcx.lint_node(lint::builtin::PRIVATE_IN_PUBLIC,
1433                                            node_id,
1434                                            self.span,
1435                                            &format!("private type `{}` in public \
1436                                                      interface (error E0446)", ty));
1437                     }
1438                 }
1439             }
1440         }
1441
1442         ty.super_visit_with(self)
1443     }
1444 }
1445
1446 struct PrivateItemsInPublicInterfacesVisitor<'a, 'tcx: 'a> {
1447     tcx: TyCtxt<'a, 'tcx, 'tcx>,
1448     has_pub_restricted: bool,
1449     old_error_set: &'a NodeSet,
1450     inner_visibility: ty::Visibility,
1451 }
1452
1453 impl<'a, 'tcx> PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1454     fn check(&self, item_id: ast::NodeId, required_visibility: ty::Visibility)
1455              -> SearchInterfaceForPrivateItemsVisitor<'a, 'tcx> {
1456         let mut has_old_errors = false;
1457
1458         // Slow path taken only if there any errors in the crate.
1459         for &id in self.old_error_set {
1460             // Walk up the nodes until we find `item_id` (or we hit a root).
1461             let mut id = id;
1462             loop {
1463                 if id == item_id {
1464                     has_old_errors = true;
1465                     break;
1466                 }
1467                 let parent = self.tcx.hir.get_parent_node(id);
1468                 if parent == id {
1469                     break;
1470                 }
1471                 id = parent;
1472             }
1473
1474             if has_old_errors {
1475                 break;
1476             }
1477         }
1478
1479         SearchInterfaceForPrivateItemsVisitor {
1480             tcx: self.tcx,
1481             item_def_id: self.tcx.hir.local_def_id(item_id),
1482             span: self.tcx.hir.span(item_id),
1483             min_visibility: ty::Visibility::Public,
1484             required_visibility,
1485             has_pub_restricted: self.has_pub_restricted,
1486             has_old_errors,
1487             in_assoc_ty: false,
1488         }
1489     }
1490 }
1491
1492 impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1493     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
1494         NestedVisitorMap::OnlyBodies(&self.tcx.hir)
1495     }
1496
1497     fn visit_item(&mut self, item: &'tcx hir::Item) {
1498         let tcx = self.tcx;
1499         let min = |vis1: ty::Visibility, vis2| {
1500             if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
1501         };
1502
1503         let item_visibility = ty::Visibility::from_hir(&item.vis, item.id, tcx);
1504
1505         match item.node {
1506             // Crates are always public
1507             hir::ItemExternCrate(..) => {}
1508             // All nested items are checked by visit_item
1509             hir::ItemMod(..) => {}
1510             // Checked in resolve
1511             hir::ItemUse(..) => {}
1512             // No subitems
1513             hir::ItemGlobalAsm(..) => {}
1514             // Subitems of these items have inherited publicity
1515             hir::ItemConst(..) | hir::ItemStatic(..) | hir::ItemFn(..) |
1516             hir::ItemTy(..) => {
1517                 self.check(item.id, item_visibility).generics().predicates().ty();
1518
1519                 // Recurse for e.g. `impl Trait` (see `visit_ty`).
1520                 self.inner_visibility = item_visibility;
1521                 intravisit::walk_item(self, item);
1522             }
1523             hir::ItemTrait(.., ref trait_item_refs) => {
1524                 self.check(item.id, item_visibility).generics().predicates();
1525
1526                 for trait_item_ref in trait_item_refs {
1527                     let mut check = self.check(trait_item_ref.id.node_id, item_visibility);
1528                     check.in_assoc_ty = trait_item_ref.kind == hir::AssociatedItemKind::Type;
1529                     check.generics().predicates();
1530
1531                     if trait_item_ref.kind == hir::AssociatedItemKind::Type &&
1532                        !trait_item_ref.defaultness.has_value() {
1533                         // No type to visit.
1534                     } else {
1535                         check.ty();
1536                     }
1537                 }
1538             }
1539             hir::ItemTraitAlias(..) => {
1540                 self.check(item.id, item_visibility).generics().predicates();
1541             }
1542             hir::ItemEnum(ref def, _) => {
1543                 self.check(item.id, item_visibility).generics().predicates();
1544
1545                 for variant in &def.variants {
1546                     for field in variant.node.data.fields() {
1547                         self.check(field.id, item_visibility).ty();
1548                     }
1549                 }
1550             }
1551             // Subitems of foreign modules have their own publicity
1552             hir::ItemForeignMod(ref foreign_mod) => {
1553                 for foreign_item in &foreign_mod.items {
1554                     let vis = ty::Visibility::from_hir(&foreign_item.vis, item.id, tcx);
1555                     self.check(foreign_item.id, vis).generics().predicates().ty();
1556                 }
1557             }
1558             // Subitems of structs and unions have their own publicity
1559             hir::ItemStruct(ref struct_def, _) |
1560             hir::ItemUnion(ref struct_def, _) => {
1561                 self.check(item.id, item_visibility).generics().predicates();
1562
1563                 for field in struct_def.fields() {
1564                     let field_visibility = ty::Visibility::from_hir(&field.vis, item.id, tcx);
1565                     self.check(field.id, min(item_visibility, field_visibility)).ty();
1566                 }
1567             }
1568             // An inherent impl is public when its type is public
1569             // Subitems of inherent impls have their own publicity
1570             hir::ItemImpl(.., None, _, ref impl_item_refs) => {
1571                 let ty_vis =
1572                     self.check(item.id, ty::Visibility::Invisible).ty().min_visibility;
1573                 self.check(item.id, ty_vis).generics().predicates();
1574
1575                 for impl_item_ref in impl_item_refs {
1576                     let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1577                     let impl_item_vis = ty::Visibility::from_hir(&impl_item.vis, item.id, tcx);
1578                     let mut check = self.check(impl_item.id, min(impl_item_vis, ty_vis));
1579                     check.in_assoc_ty = impl_item_ref.kind == hir::AssociatedItemKind::Type;
1580                     check.generics().predicates().ty();
1581
1582                     // Recurse for e.g. `impl Trait` (see `visit_ty`).
1583                     self.inner_visibility = impl_item_vis;
1584                     intravisit::walk_impl_item(self, impl_item);
1585                 }
1586             }
1587             // A trait impl is public when both its type and its trait are public
1588             // Subitems of trait impls have inherited publicity
1589             hir::ItemImpl(.., Some(_), _, ref impl_item_refs) => {
1590                 let vis = self.check(item.id, ty::Visibility::Invisible)
1591                               .ty().impl_trait_ref().min_visibility;
1592                 self.check(item.id, vis).generics().predicates();
1593                 for impl_item_ref in impl_item_refs {
1594                     let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1595                     let mut check = self.check(impl_item.id, vis);
1596                     check.in_assoc_ty = impl_item_ref.kind == hir::AssociatedItemKind::Type;
1597                     check.generics().predicates().ty();
1598
1599                     // Recurse for e.g. `impl Trait` (see `visit_ty`).
1600                     self.inner_visibility = vis;
1601                     intravisit::walk_impl_item(self, impl_item);
1602                 }
1603             }
1604         }
1605     }
1606
1607     fn visit_impl_item(&mut self, _impl_item: &'tcx hir::ImplItem) {
1608         // handled in `visit_item` above
1609     }
1610
1611     fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
1612         if let hir::TyImplTraitExistential(..) = ty.node {
1613             // Check the traits being exposed, as they're separate,
1614             // e.g. `impl Iterator<Item=T>` has two predicates,
1615             // `X: Iterator` and `<X as Iterator>::Item == T`,
1616             // where `X` is the `impl Iterator<Item=T>` itself,
1617             // stored in `predicates_of`, not in the `Ty` itself.
1618             self.check(ty.id, self.inner_visibility).predicates();
1619         }
1620
1621         intravisit::walk_ty(self, ty);
1622     }
1623
1624     // Don't recurse into expressions in array sizes or const initializers
1625     fn visit_expr(&mut self, _: &'tcx hir::Expr) {}
1626     // Don't recurse into patterns in function arguments
1627     fn visit_pat(&mut self, _: &'tcx hir::Pat) {}
1628 }
1629
1630 pub fn provide(providers: &mut Providers) {
1631     *providers = Providers {
1632         privacy_access_levels,
1633         ..*providers
1634     };
1635 }
1636
1637 pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Rc<AccessLevels> {
1638     tcx.privacy_access_levels(LOCAL_CRATE)
1639 }
1640
1641 fn privacy_access_levels<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1642                                    krate: CrateNum)
1643                                    -> Rc<AccessLevels> {
1644     assert_eq!(krate, LOCAL_CRATE);
1645
1646     let krate = tcx.hir.krate();
1647     let empty_tables = ty::TypeckTables::empty(None);
1648
1649     // Check privacy of names not checked in previous compilation stages.
1650     let mut visitor = NamePrivacyVisitor {
1651         tcx,
1652         tables: &empty_tables,
1653         current_item: CRATE_NODE_ID,
1654         empty_tables: &empty_tables,
1655     };
1656     intravisit::walk_crate(&mut visitor, krate);
1657
1658     // Check privacy of explicitly written types and traits as well as
1659     // inferred types of expressions and patterns.
1660     let mut visitor = TypePrivacyVisitor {
1661         tcx,
1662         tables: &empty_tables,
1663         current_item: DefId::local(CRATE_DEF_INDEX),
1664         in_body: false,
1665         span: krate.span,
1666         empty_tables: &empty_tables,
1667     };
1668     intravisit::walk_crate(&mut visitor, krate);
1669
1670     // Build up a set of all exported items in the AST. This is a set of all
1671     // items which are reachable from external crates based on visibility.
1672     let mut visitor = EmbargoVisitor {
1673         tcx,
1674         access_levels: Default::default(),
1675         prev_level: Some(AccessLevel::Public),
1676         changed: false,
1677     };
1678     loop {
1679         intravisit::walk_crate(&mut visitor, krate);
1680         if visitor.changed {
1681             visitor.changed = false;
1682         } else {
1683             break
1684         }
1685     }
1686     visitor.update(ast::CRATE_NODE_ID, Some(AccessLevel::Public));
1687
1688     {
1689         let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
1690             tcx,
1691             access_levels: &visitor.access_levels,
1692             in_variant: false,
1693             old_error_set: NodeSet(),
1694         };
1695         intravisit::walk_crate(&mut visitor, krate);
1696
1697
1698         let has_pub_restricted = {
1699             let mut pub_restricted_visitor = PubRestrictedVisitor {
1700                 tcx,
1701                 has_pub_restricted: false
1702             };
1703             intravisit::walk_crate(&mut pub_restricted_visitor, krate);
1704             pub_restricted_visitor.has_pub_restricted
1705         };
1706
1707         // Check for private types and traits in public interfaces
1708         let mut visitor = PrivateItemsInPublicInterfacesVisitor {
1709             tcx,
1710             has_pub_restricted,
1711             old_error_set: &visitor.old_error_set,
1712             inner_visibility: ty::Visibility::Public,
1713         };
1714         krate.visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));
1715     }
1716
1717     Rc::new(visitor.access_levels)
1718 }
1719
1720 #[cfg(not(stage0))] // remove after the next snapshot
1721 __build_diagnostic_array! { librustc_privacy, DIAGNOSTICS }