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 #![crate_name = "rustc_privacy"]
  12 #![unstable(feature = "rustc_private", issue = "27812")]
  13 #![crate_type = "dylib"]
  14 #![crate_type = "rlib"]
  15 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
  16       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
  17       html_root_url = "https://doc.rust-lang.org/nightly/")]
  18 #![deny(warnings)]
  19
  20 #![feature(rustc_diagnostic_macros)]
  21 #![feature(rustc_private)]
  22 #![feature(staged_api)]
  23
  24 extern crate rustc;
  25 #[macro_use] extern crate syntax;
  26 extern crate syntax_pos;
  27
  28 use rustc::dep_graph::DepNode;
  29 use rustc::hir::{self, PatKind};
  30 use rustc::hir::def::{self, Def, CtorKind};
  31 use rustc::hir::def_id::{CRATE_DEF_INDEX, DefId};
  32 use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
  33 use rustc::hir::itemlikevisit::DeepVisitor;
  34 use rustc::hir::pat_util::EnumerateAndAdjustIterator;
  35 use rustc::lint;
  36 use rustc::middle::privacy::{AccessLevel, AccessLevels};
  37 use rustc::ty::{self, TyCtxt, Ty, TypeFoldable};
  38 use rustc::ty::fold::TypeVisitor;
  39 use rustc::util::nodemap::NodeSet;
  40 use syntax::ast;
  41 use syntax_pos::Span;
  42
  43 use std::cmp;
  44 use std::mem::replace;
  45
  46 pub mod diagnostics;
  47
  48 ////////////////////////////////////////////////////////////////////////////////
  49 /// The embargo visitor, used to determine the exports of the ast
  50 ////////////////////////////////////////////////////////////////////////////////
  51
  52 struct EmbargoVisitor<'a, 'tcx: 'a> {
  53     tcx: TyCtxt<'a, 'tcx, 'tcx>,
  54     export_map: &'a def::ExportMap,
  55
  56     // Accessibility levels for reachable nodes
  57     access_levels: AccessLevels,
  58     // Previous accessibility level, None means unreachable
  59     prev_level: Option<AccessLevel>,
  60     // Have something changed in the level map?
  61     changed: bool,
  62 }
  63
  64 struct ReachEverythingInTheInterfaceVisitor<'b, 'a: 'b, 'tcx: 'a> {
  65     item_def_id: DefId,
  66     ev: &'b mut EmbargoVisitor<'a, 'tcx>,
  67 }
  68
  69 impl<'a, 'tcx> EmbargoVisitor<'a, 'tcx> {
  70     fn item_ty_level(&self, item_def_id: DefId) -> Option<AccessLevel> {
  71         let ty_def_id = match self.tcx.item_type(item_def_id).sty {
  72             ty::TyAdt(adt, _) => adt.did,
  73             ty::TyDynamic(ref obj, ..) if obj.principal().is_some() =>
  74                 obj.principal().unwrap().def_id(),
  75             ty::TyProjection(ref proj) => proj.trait_ref.def_id,
  76             _ => return Some(AccessLevel::Public)
  77         };
  78         if let Some(node_id) = self.tcx.hir.as_local_node_id(ty_def_id) {
  79             self.get(node_id)
  80         } else {
  81             Some(AccessLevel::Public)
  82         }
  83     }
  84
  85     fn impl_trait_level(&self, impl_def_id: DefId) -> Option<AccessLevel> {
  86         if let Some(trait_ref) = self.tcx.impl_trait_ref(impl_def_id) {
  87             if let Some(node_id) = self.tcx.hir.as_local_node_id(trait_ref.def_id) {
  88                 return self.get(node_id);
  89             }
  90         }
  91         Some(AccessLevel::Public)
  92     }
  93
  94     fn get(&self, id: ast::NodeId) -> Option<AccessLevel> {
  95         self.access_levels.map.get(&id).cloned()
  96     }
  97
  98     // Updates node level and returns the updated level
  99     fn update(&mut self, id: ast::NodeId, level: Option<AccessLevel>) -> Option<AccessLevel> {
 100         let old_level = self.get(id);
 101         // Accessibility levels can only grow
 102         if level > old_level {
 103             self.access_levels.map.insert(id, level.unwrap());
 104             self.changed = true;
 105             level
 106         } else {
 107             old_level
 108         }
 109     }
 110
 111     fn reach<'b>(&'b mut self, item_id: ast::NodeId)
 112                  -> ReachEverythingInTheInterfaceVisitor<'b, 'a, 'tcx> {
 113         ReachEverythingInTheInterfaceVisitor {
 114             item_def_id: self.tcx.hir.local_def_id(item_id),
 115             ev: self,
 116         }
 117     }
 118 }
 119
 120 impl<'a, 'tcx> Visitor<'tcx> for EmbargoVisitor<'a, 'tcx> {
 121     /// We want to visit items in the context of their containing
 122     /// module and so forth, so supply a crate for doing a deep walk.
 123     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 124         NestedVisitorMap::All(&self.tcx.hir)
 125     }
 126
 127     fn visit_item(&mut self, item: &'tcx hir::Item) {
 128         let inherited_item_level = match item.node {
 129             // Impls inherit level from their types and traits
 130             hir::ItemImpl(..) => {
 131                 let def_id = self.tcx.hir.local_def_id(item.id);
 132                 cmp::min(self.item_ty_level(def_id), self.impl_trait_level(def_id))
 133             }
 134             hir::ItemDefaultImpl(..) => {
 135                 let def_id = self.tcx.hir.local_def_id(item.id);
 136                 self.impl_trait_level(def_id)
 137             }
 138             // Foreign mods inherit level from parents
 139             hir::ItemForeignMod(..) => {
 140                 self.prev_level
 141             }
 142             // Other `pub` items inherit levels from parents
 143             _ => {
 144                 if item.vis == hir::Public { self.prev_level } else { None }
 145             }
 146         };
 147
 148         // Update level of the item itself
 149         let item_level = self.update(item.id, inherited_item_level);
 150
 151         // Update levels of nested things
 152         match item.node {
 153             hir::ItemEnum(ref def, _) => {
 154                 for variant in &def.variants {
 155                     let variant_level = self.update(variant.node.data.id(), item_level);
 156                     for field in variant.node.data.fields() {
 157                         self.update(field.id, variant_level);
 158                     }
 159                 }
 160             }
 161             hir::ItemImpl(.., None, _, ref impl_item_refs) => {
 162                 for impl_item_ref in impl_item_refs {
 163                     if impl_item_ref.vis == hir::Public {
 164                         self.update(impl_item_ref.id.node_id, item_level);
 165                     }
 166                 }
 167             }
 168             hir::ItemImpl(.., Some(_), _, ref impl_item_refs) => {
 169                 for impl_item_ref in impl_item_refs {
 170                     self.update(impl_item_ref.id.node_id, item_level);
 171                 }
 172             }
 173             hir::ItemTrait(.., ref trait_item_refs) => {
 174                 for trait_item_ref in trait_item_refs {
 175                     self.update(trait_item_ref.id.node_id, item_level);
 176                 }
 177             }
 178             hir::ItemStruct(ref def, _) | hir::ItemUnion(ref def, _) => {
 179                 if !def.is_struct() {
 180                     self.update(def.id(), item_level);
 181                 }
 182                 for field in def.fields() {
 183                     if field.vis == hir::Public {
 184                         self.update(field.id, item_level);
 185                     }
 186                 }
 187             }
 188             hir::ItemForeignMod(ref foreign_mod) => {
 189                 for foreign_item in &foreign_mod.items {
 190                     if foreign_item.vis == hir::Public {
 191                         self.update(foreign_item.id, item_level);
 192                     }
 193                 }
 194             }
 195             _ => {}
 196         }
 197
 198         // Mark all items in interfaces of reachable items as reachable
 199         match item.node {
 200             // The interface is empty
 201             hir::ItemExternCrate(..) => {}
 202             // All nested items are checked by visit_item
 203             hir::ItemMod(..) => {}
 204             // Reexports are handled in visit_mod
 205             hir::ItemUse(..) => {}
 206             // The interface is empty
 207             hir::ItemDefaultImpl(..) => {}
 208             // Visit everything
 209             hir::ItemConst(..) | hir::ItemStatic(..) |
 210             hir::ItemFn(..) | hir::ItemTy(..) => {
 211                 if item_level.is_some() {
 212                     self.reach(item.id).generics().predicates().item_type();
 213                 }
 214             }
 215             hir::ItemTrait(.., ref trait_item_refs) => {
 216                 if item_level.is_some() {
 217                     self.reach(item.id).generics().predicates();
 218
 219                     for trait_item_ref in trait_item_refs {
 220                         let mut reach = self.reach(trait_item_ref.id.node_id);
 221                         reach.generics().predicates();
 222
 223                         if trait_item_ref.kind == hir::AssociatedItemKind::Type &&
 224                            !trait_item_ref.defaultness.has_value() {
 225                             // No type to visit.
 226                         } else {
 227                             reach.item_type();
 228                         }
 229                     }
 230                 }
 231             }
 232             // Visit everything except for private impl items
 233             hir::ItemImpl(.., ref trait_ref, _, ref impl_item_refs) => {
 234                 if item_level.is_some() {
 235                     self.reach(item.id).generics().predicates().impl_trait_ref();
 236
 237                     for impl_item_ref in impl_item_refs {
 238                         let id = impl_item_ref.id.node_id;
 239                         if trait_ref.is_some() || self.get(id).is_some() {
 240                             self.reach(id).generics().predicates().item_type();
 241                         }
 242                     }
 243                 }
 244             }
 245
 246             // Visit everything, but enum variants have their own levels
 247             hir::ItemEnum(ref def, _) => {
 248                 if item_level.is_some() {
 249                     self.reach(item.id).generics().predicates();
 250                 }
 251                 for variant in &def.variants {
 252                     if self.get(variant.node.data.id()).is_some() {
 253                         for field in variant.node.data.fields() {
 254                             self.reach(field.id).item_type();
 255                         }
 256                         // Corner case: if the variant is reachable, but its
 257                         // enum is not, make the enum reachable as well.
 258                         self.update(item.id, Some(AccessLevel::Reachable));
 259                     }
 260                 }
 261             }
 262             // Visit everything, but foreign items have their own levels
 263             hir::ItemForeignMod(ref foreign_mod) => {
 264                 for foreign_item in &foreign_mod.items {
 265                     if self.get(foreign_item.id).is_some() {
 266                         self.reach(foreign_item.id).generics().predicates().item_type();
 267                     }
 268                 }
 269             }
 270             // Visit everything except for private fields
 271             hir::ItemStruct(ref struct_def, _) |
 272             hir::ItemUnion(ref struct_def, _) => {
 273                 if item_level.is_some() {
 274                     self.reach(item.id).generics().predicates();
 275                     for field in struct_def.fields() {
 276                         if self.get(field.id).is_some() {
 277                             self.reach(field.id).item_type();
 278                         }
 279                     }
 280                 }
 281             }
 282         }
 283
 284         let orig_level = self.prev_level;
 285         self.prev_level = item_level;
 286
 287         intravisit::walk_item(self, item);
 288
 289         self.prev_level = orig_level;
 290     }
 291
 292     fn visit_block(&mut self, b: &'tcx hir::Block) {
 293         let orig_level = replace(&mut self.prev_level, None);
 294
 295         // Blocks can have public items, for example impls, but they always
 296         // start as completely private regardless of publicity of a function,
 297         // constant, type, field, etc. in which this block resides
 298         intravisit::walk_block(self, b);
 299
 300         self.prev_level = orig_level;
 301     }
 302
 303     fn visit_mod(&mut self, m: &'tcx hir::Mod, _sp: Span, id: ast::NodeId) {
 304         // This code is here instead of in visit_item so that the
 305         // crate module gets processed as well.
 306         if self.prev_level.is_some() {
 307             if let Some(exports) = self.export_map.get(&id) {
 308                 for export in exports {
 309                     if let Some(node_id) = self.tcx.hir.as_local_node_id(export.def.def_id()) {
 310                         self.update(node_id, Some(AccessLevel::Exported));
 311                     }
 312                 }
 313             }
 314         }
 315
 316         intravisit::walk_mod(self, m, id);
 317     }
 318
 319     fn visit_macro_def(&mut self, md: &'tcx hir::MacroDef) {
 320         self.update(md.id, Some(AccessLevel::Public));
 321     }
 322
 323     fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
 324         if let hir::TyImplTrait(..) = ty.node {
 325             if self.get(ty.id).is_some() {
 326                 // Reach the (potentially private) type and the API being exposed.
 327                 self.reach(ty.id).item_type().predicates();
 328             }
 329         }
 330
 331         intravisit::walk_ty(self, ty);
 332     }
 333 }
 334
 335 impl<'b, 'a, 'tcx> ReachEverythingInTheInterfaceVisitor<'b, 'a, 'tcx> {
 336     fn generics(&mut self) -> &mut Self {
 337         self.ev.tcx.item_generics(self.item_def_id).visit_with(self);
 338         self
 339     }
 340
 341     fn predicates(&mut self) -> &mut Self {
 342         self.ev.tcx.item_predicates(self.item_def_id).visit_with(self);
 343         self
 344     }
 345
 346     fn item_type(&mut self) -> &mut Self {
 347         self.ev.tcx.item_type(self.item_def_id).visit_with(self);
 348         self
 349     }
 350
 351     fn impl_trait_ref(&mut self) -> &mut Self {
 352         self.ev.tcx.impl_trait_ref(self.item_def_id).visit_with(self);
 353         self
 354     }
 355 }
 356
 357 impl<'b, 'a, 'tcx> TypeVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'b, 'a, 'tcx> {
 358     fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
 359         let ty_def_id = match ty.sty {
 360             ty::TyAdt(adt, _) => Some(adt.did),
 361             ty::TyDynamic(ref obj, ..) => obj.principal().map(|p| p.def_id()),
 362             ty::TyProjection(ref proj) => Some(proj.trait_ref.def_id),
 363             ty::TyFnDef(def_id, ..) |
 364             ty::TyAnon(def_id, _) => Some(def_id),
 365             _ => None
 366         };
 367
 368         if let Some(def_id) = ty_def_id {
 369             if let Some(node_id) = self.ev.tcx.hir.as_local_node_id(def_id) {
 370                 self.ev.update(node_id, Some(AccessLevel::Reachable));
 371             }
 372         }
 373
 374         ty.super_visit_with(self)
 375     }
 376
 377     fn visit_trait_ref(&mut self, trait_ref: ty::TraitRef<'tcx>) -> bool {
 378         if let Some(node_id) = self.ev.tcx.hir.as_local_node_id(trait_ref.def_id) {
 379             let item = self.ev.tcx.hir.expect_item(node_id);
 380             self.ev.update(item.id, Some(AccessLevel::Reachable));
 381         }
 382
 383         trait_ref.super_visit_with(self)
 384     }
 385 }
 386
 387 ////////////////////////////////////////////////////////////////////////////////
 388 /// The privacy visitor, where privacy checks take place (violations reported)
 389 ////////////////////////////////////////////////////////////////////////////////
 390
 391 struct PrivacyVisitor<'a, 'tcx: 'a> {
 392     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 393     curitem: DefId,
 394     in_foreign: bool,
 395     tables: &'a ty::TypeckTables<'tcx>,
 396 }
 397
 398 impl<'a, 'tcx> PrivacyVisitor<'a, 'tcx> {
 399     fn item_is_accessible(&self, did: DefId) -> bool {
 400         match self.tcx.hir.as_local_node_id(did) {
 401             Some(node_id) =>
 402                 ty::Visibility::from_hir(&self.tcx.hir.expect_item(node_id).vis, node_id, self.tcx),
 403             None => self.tcx.sess.cstore.visibility(did),
 404         }.is_accessible_from(self.curitem, self.tcx)
 405     }
 406
 407     // Checks that a field is in scope.
 408     fn check_field(&mut self, span: Span, def: &'tcx ty::AdtDef, field: &'tcx ty::FieldDef) {
 409         if !def.is_enum() && !field.vis.is_accessible_from(self.curitem, self.tcx) {
 410             struct_span_err!(self.tcx.sess, span, E0451, "field `{}` of {} `{}` is private",
 411                       field.name, def.variant_descr(), self.tcx.item_path_str(def.did))
 412                 .span_label(span, &format!("field `{}` is private", field.name))
 413                 .emit();
 414         }
 415     }
 416
 417     // Checks that a method is in scope.
 418     fn check_method(&mut self, span: Span, method_def_id: DefId) {
 419         match self.tcx.associated_item(method_def_id).container {
 420             // Trait methods are always all public. The only controlling factor
 421             // is whether the trait itself is accessible or not.
 422             ty::TraitContainer(trait_def_id) if !self.item_is_accessible(trait_def_id) => {
 423                 let msg = format!("source trait `{}` is private",
 424                                   self.tcx.item_path_str(trait_def_id));
 425                 self.tcx.sess.span_err(span, &msg);
 426             }
 427             _ => {}
 428         }
 429     }
 430 }
 431
 432 impl<'a, 'tcx> Visitor<'tcx> for PrivacyVisitor<'a, 'tcx> {
 433     /// We want to visit items in the context of their containing
 434     /// module and so forth, so supply a crate for doing a deep walk.
 435     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 436         NestedVisitorMap::All(&self.tcx.hir)
 437     }
 438
 439     fn visit_nested_body(&mut self, body: hir::BodyId) {
 440         let old_tables = self.tables;
 441         self.tables = self.tcx.body_tables(body);
 442         let body = self.tcx.hir.body(body);
 443         self.visit_body(body);
 444         self.tables = old_tables;
 445     }
 446
 447     fn visit_item(&mut self, item: &'tcx hir::Item) {
 448         let orig_curitem = replace(&mut self.curitem, self.tcx.hir.local_def_id(item.id));
 449         intravisit::walk_item(self, item);
 450         self.curitem = orig_curitem;
 451     }
 452
 453     fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
 454         match expr.node {
 455             hir::ExprMethodCall(..) => {
 456                 let method_call = ty::MethodCall::expr(expr.id);
 457                 let method = self.tables.method_map[&method_call];
 458                 self.check_method(expr.span, method.def_id);
 459             }
 460             hir::ExprStruct(ref qpath, ref expr_fields, _) => {
 461                 let def = self.tables.qpath_def(qpath, expr.id);
 462                 let adt = self.tables.expr_ty(expr).ty_adt_def().unwrap();
 463                 let variant = adt.variant_of_def(def);
 464                 // RFC 736: ensure all unmentioned fields are visible.
 465                 // Rather than computing the set of unmentioned fields
 466                 // (i.e. `all_fields - fields`), just check them all,
 467                 // unless the ADT is a union, then unmentioned fields
 468                 // are not checked.
 469                 if adt.is_union() {
 470                     for expr_field in expr_fields {
 471                         self.check_field(expr.span, adt, variant.field_named(expr_field.name.node));
 472                     }
 473                 } else {
 474                     for field in &variant.fields {
 475                         let expr_field = expr_fields.iter().find(|f| f.name.node == field.name);
 476                         let span = if let Some(f) = expr_field { f.span } else { expr.span };
 477                         self.check_field(span, adt, field);
 478                     }
 479                 }
 480             }
 481             hir::ExprPath(hir::QPath::Resolved(_, ref path)) => {
 482                 if let Def::StructCtor(_, CtorKind::Fn) = path.def {
 483                     let adt_def = self.tcx.expect_variant_def(path.def);
 484                     let private_indexes = adt_def.fields.iter().enumerate().filter(|&(_, field)| {
 485                         !field.vis.is_accessible_from(self.curitem, self.tcx)
 486                     }).map(|(i, _)| i).collect::<Vec<_>>();
 487
 488                     if !private_indexes.is_empty() {
 489                         let mut error = struct_span_err!(self.tcx.sess, expr.span, E0450,
 490                                                          "cannot invoke tuple struct constructor \
 491                                                           with private fields");
 492                         error.span_label(expr.span,
 493                                          &format!("cannot construct with a private field"));
 494
 495                         if let Some(node_id) = self.tcx.hir.as_local_node_id(adt_def.did) {
 496                             let node = self.tcx.hir.find(node_id);
 497                             if let Some(hir::map::NodeStructCtor(vdata)) = node {
 498                                 for i in private_indexes {
 499                                     error.span_label(vdata.fields()[i].span,
 500                                                      &format!("private field declared here"));
 501                                 }
 502                             }
 503                         }
 504                         error.emit();
 505                     }
 506                 }
 507             }
 508             _ => {}
 509         }
 510
 511         intravisit::walk_expr(self, expr);
 512     }
 513
 514     fn visit_pat(&mut self, pattern: &'tcx hir::Pat) {
 515         // Foreign functions do not have their patterns mapped in the def_map,
 516         // and there's nothing really relevant there anyway, so don't bother
 517         // checking privacy. If you can name the type then you can pass it to an
 518         // external C function anyway.
 519         if self.in_foreign { return }
 520
 521         match pattern.node {
 522             PatKind::Struct(ref qpath, ref fields, _) => {
 523                 let def = self.tables.qpath_def(qpath, pattern.id);
 524                 let adt = self.tables.pat_ty(pattern).ty_adt_def().unwrap();
 525                 let variant = adt.variant_of_def(def);
 526                 for field in fields {
 527                     self.check_field(field.span, adt, variant.field_named(field.node.name));
 528                 }
 529             }
 530             PatKind::TupleStruct(_, ref fields, ddpos) => {
 531                 match self.tables.pat_ty(pattern).sty {
 532                     // enum fields have no privacy at this time
 533                     ty::TyAdt(def, _) if !def.is_enum() => {
 534                         let expected_len = def.struct_variant().fields.len();
 535                         for (i, field) in fields.iter().enumerate_and_adjust(expected_len, ddpos) {
 536                             if let PatKind::Wild = field.node {
 537                                 continue
 538                             }
 539                             self.check_field(field.span, def, &def.struct_variant().fields[i]);
 540                         }
 541                     }
 542                     _ => {}
 543                 }
 544             }
 545             _ => {}
 546         }
 547
 548         intravisit::walk_pat(self, pattern);
 549     }
 550
 551     fn visit_foreign_item(&mut self, fi: &'tcx hir::ForeignItem) {
 552         self.in_foreign = true;
 553         intravisit::walk_foreign_item(self, fi);
 554         self.in_foreign = false;
 555     }
 556 }
 557
 558 ///////////////////////////////////////////////////////////////////////////////
 559 /// Obsolete visitors for checking for private items in public interfaces.
 560 /// These visitors are supposed to be kept in frozen state and produce an
 561 /// "old error node set". For backward compatibility the new visitor reports
 562 /// warnings instead of hard errors when the erroneous node is not in this old set.
 563 ///////////////////////////////////////////////////////////////////////////////
 564
 565 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx: 'a> {
 566     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 567     access_levels: &'a AccessLevels,
 568     in_variant: bool,
 569     // set of errors produced by this obsolete visitor
 570     old_error_set: NodeSet,
 571 }
 572
 573 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b: 'a, 'tcx: 'b> {
 574     inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
 575     /// whether the type refers to private types.
 576     contains_private: bool,
 577     /// whether we've recurred at all (i.e. if we're pointing at the
 578     /// first type on which visit_ty was called).
 579     at_outer_type: bool,
 580     // whether that first type is a public path.
 581     outer_type_is_public_path: bool,
 582 }
 583
 584 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
 585     fn path_is_private_type(&self, path: &hir::Path) -> bool {
 586         let did = match path.def {
 587             Def::PrimTy(..) | Def::SelfTy(..) => return false,
 588             def => def.def_id(),
 589         };
 590
 591         // A path can only be private if:
 592         // it's in this crate...
 593         if let Some(node_id) = self.tcx.hir.as_local_node_id(did) {
 594             // .. and it corresponds to a private type in the AST (this returns
 595             // None for type parameters)
 596             match self.tcx.hir.find(node_id) {
 597                 Some(hir::map::NodeItem(ref item)) => item.vis != hir::Public,
 598                 Some(_) | None => false,
 599             }
 600         } else {
 601             return false
 602         }
 603     }
 604
 605     fn trait_is_public(&self, trait_id: ast::NodeId) -> bool {
 606         // FIXME: this would preferably be using `exported_items`, but all
 607         // traits are exported currently (see `EmbargoVisitor.exported_trait`)
 608         self.access_levels.is_public(trait_id)
 609     }
 610
 611     fn check_ty_param_bound(&mut self,
 612                             ty_param_bound: &hir::TyParamBound) {
 613         if let hir::TraitTyParamBound(ref trait_ref, _) = *ty_param_bound {
 614             if self.path_is_private_type(&trait_ref.trait_ref.path) {
 615                 self.old_error_set.insert(trait_ref.trait_ref.ref_id);
 616             }
 617         }
 618     }
 619
 620     fn item_is_public(&self, id: &ast::NodeId, vis: &hir::Visibility) -> bool {
 621         self.access_levels.is_reachable(*id) || *vis == hir::Public
 622     }
 623 }
 624
 625 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
 626     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v> {
 627         NestedVisitorMap::None
 628     }
 629
 630     fn visit_ty(&mut self, ty: &hir::Ty) {
 631         if let hir::TyPath(hir::QPath::Resolved(_, ref path)) = ty.node {
 632             if self.inner.path_is_private_type(path) {
 633                 self.contains_private = true;
 634                 // found what we're looking for so let's stop
 635                 // working.
 636                 return
 637             }
 638         }
 639         if let hir::TyPath(_) = ty.node {
 640             if self.at_outer_type {
 641                 self.outer_type_is_public_path = true;
 642             }
 643         }
 644         self.at_outer_type = false;
 645         intravisit::walk_ty(self, ty)
 646     }
 647
 648     // don't want to recurse into [, .. expr]
 649     fn visit_expr(&mut self, _: &hir::Expr) {}
 650 }
 651
 652 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
 653     /// We want to visit items in the context of their containing
 654     /// module and so forth, so supply a crate for doing a deep walk.
 655     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
 656         NestedVisitorMap::All(&self.tcx.hir)
 657     }
 658
 659     fn visit_item(&mut self, item: &'tcx hir::Item) {
 660         match item.node {
 661             // contents of a private mod can be reexported, so we need
 662             // to check internals.
 663             hir::ItemMod(_) => {}
 664
 665             // An `extern {}` doesn't introduce a new privacy
 666             // namespace (the contents have their own privacies).
 667             hir::ItemForeignMod(_) => {}
 668
 669             hir::ItemTrait(.., ref bounds, _) => {
 670                 if !self.trait_is_public(item.id) {
 671                     return
 672                 }
 673
 674                 for bound in bounds.iter() {
 675                     self.check_ty_param_bound(bound)
 676                 }
 677             }
 678
 679             // impls need some special handling to try to offer useful
 680             // error messages without (too many) false positives
 681             // (i.e. we could just return here to not check them at
 682             // all, or some worse estimation of whether an impl is
 683             // publicly visible).
 684             hir::ItemImpl(.., ref g, ref trait_ref, ref self_, ref impl_item_refs) => {
 685                 // `impl [... for] Private` is never visible.
 686                 let self_contains_private;
 687                 // impl [... for] Public<...>, but not `impl [... for]
 688                 // Vec<Public>` or `(Public,)` etc.
 689                 let self_is_public_path;
 690
 691                 // check the properties of the Self type:
 692                 {
 693                     let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
 694                         inner: self,
 695                         contains_private: false,
 696                         at_outer_type: true,
 697                         outer_type_is_public_path: false,
 698                     };
 699                     visitor.visit_ty(&self_);
 700                     self_contains_private = visitor.contains_private;
 701                     self_is_public_path = visitor.outer_type_is_public_path;
 702                 }
 703
 704                 // miscellaneous info about the impl
 705
 706                 // `true` iff this is `impl Private for ...`.
 707                 let not_private_trait =
 708                     trait_ref.as_ref().map_or(true, // no trait counts as public trait
 709                                               |tr| {
 710                         let did = tr.path.def.def_id();
 711
 712                         if let Some(node_id) = self.tcx.hir.as_local_node_id(did) {
 713                             self.trait_is_public(node_id)
 714                         } else {
 715                             true // external traits must be public
 716                         }
 717                     });
 718
 719                 // `true` iff this is a trait impl or at least one method is public.
 720                 //
 721                 // `impl Public { $( fn ...() {} )* }` is not visible.
 722                 //
 723                 // This is required over just using the methods' privacy
 724                 // directly because we might have `impl<T: Foo<Private>> ...`,
 725                 // and we shouldn't warn about the generics if all the methods
 726                 // are private (because `T` won't be visible externally).
 727                 let trait_or_some_public_method =
 728                     trait_ref.is_some() ||
 729                     impl_item_refs.iter()
 730                                  .any(|impl_item_ref| {
 731                                      let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
 732                                      match impl_item.node {
 733                                          hir::ImplItemKind::Const(..) |
 734                                          hir::ImplItemKind::Method(..) => {
 735                                              self.access_levels.is_reachable(impl_item.id)
 736                                          }
 737                                          hir::ImplItemKind::Type(_) => false,
 738                                      }
 739                                  });
 740
 741                 if !self_contains_private &&
 742                         not_private_trait &&
 743                         trait_or_some_public_method {
 744
 745                     intravisit::walk_generics(self, g);
 746
 747                     match *trait_ref {
 748                         None => {
 749                             for impl_item_ref in impl_item_refs {
 750                                 // This is where we choose whether to walk down
 751                                 // further into the impl to check its items. We
 752                                 // should only walk into public items so that we
 753                                 // don't erroneously report errors for private
 754                                 // types in private items.
 755                                 let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
 756                                 match impl_item.node {
 757                                     hir::ImplItemKind::Const(..) |
 758                                     hir::ImplItemKind::Method(..)
 759                                         if self.item_is_public(&impl_item.id, &impl_item.vis) =>
 760                                     {
 761                                         intravisit::walk_impl_item(self, impl_item)
 762                                     }
 763                                     hir::ImplItemKind::Type(..) => {
 764                                         intravisit::walk_impl_item(self, impl_item)
 765                                     }
 766                                     _ => {}
 767                                 }
 768                             }
 769                         }
 770                         Some(ref tr) => {
 771                             // Any private types in a trait impl fall into three
 772                             // categories.
 773                             // 1. mentioned in the trait definition
 774                             // 2. mentioned in the type params/generics
 775                             // 3. mentioned in the associated types of the impl
 776                             //
 777                             // Those in 1. can only occur if the trait is in
 778                             // this crate and will've been warned about on the
 779                             // trait definition (there's no need to warn twice
 780                             // so we don't check the methods).
 781                             //
 782                             // Those in 2. are warned via walk_generics and this
 783                             // call here.
 784                             intravisit::walk_path(self, &tr.path);
 785
 786                             // Those in 3. are warned with this call.
 787                             for impl_item_ref in impl_item_refs {
 788                                 let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
 789                                 if let hir::ImplItemKind::Type(ref ty) = impl_item.node {
 790                                     self.visit_ty(ty);
 791                                 }
 792                             }
 793                         }
 794                     }
 795                 } else if trait_ref.is_none() && self_is_public_path {
 796                     // impl Public<Private> { ... }. Any public static
 797                     // methods will be visible as `Public::foo`.
 798                     let mut found_pub_static = false;
 799                     for impl_item_ref in impl_item_refs {
 800                         if self.item_is_public(&impl_item_ref.id.node_id, &impl_item_ref.vis) {
 801                             let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
 802                             match impl_item_ref.kind {
 803                                 hir::AssociatedItemKind::Const => {
 804                                     found_pub_static = true;
 805                                     intravisit::walk_impl_item(self, impl_item);
 806                                 }
 807                                 hir::AssociatedItemKind::Method { has_self: false } => {
 808                                     found_pub_static = true;
 809                                     intravisit::walk_impl_item(self, impl_item);
 810                                 }
 811                                 _ => {}
 812                             }
 813                         }
 814                     }
 815                     if found_pub_static {
 816                         intravisit::walk_generics(self, g)
 817                     }
 818                 }
 819                 return
 820             }
 821
 822             // `type ... = ...;` can contain private types, because
 823             // we're introducing a new name.
 824             hir::ItemTy(..) => return,
 825
 826             // not at all public, so we don't care
 827             _ if !self.item_is_public(&item.id, &item.vis) => {
 828                 return;
 829             }
 830
 831             _ => {}
 832         }
 833
 834         // We've carefully constructed it so that if we're here, then
 835         // any `visit_ty`'s will be called on things that are in
 836         // public signatures, i.e. things that we're interested in for
 837         // this visitor.
 838         intravisit::walk_item(self, item);
 839     }
 840
 841     fn visit_generics(&mut self, generics: &'tcx hir::Generics) {
 842         for ty_param in generics.ty_params.iter() {
 843             for bound in ty_param.bounds.iter() {
 844                 self.check_ty_param_bound(bound)
 845             }
 846         }
 847         for predicate in &generics.where_clause.predicates {
 848             match predicate {
 849                 &hir::WherePredicate::BoundPredicate(ref bound_pred) => {
 850                     for bound in bound_pred.bounds.iter() {
 851                         self.check_ty_param_bound(bound)
 852                     }
 853                 }
 854                 &hir::WherePredicate::RegionPredicate(_) => {}
 855                 &hir::WherePredicate::EqPredicate(ref eq_pred) => {
 856                     self.visit_ty(&eq_pred.rhs_ty);
 857                 }
 858             }
 859         }
 860     }
 861
 862     fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem) {
 863         if self.access_levels.is_reachable(item.id) {
 864             intravisit::walk_foreign_item(self, item)
 865         }
 866     }
 867
 868     fn visit_ty(&mut self, t: &'tcx hir::Ty) {
 869         if let hir::TyPath(hir::QPath::Resolved(_, ref path)) = t.node {
 870             if self.path_is_private_type(path) {
 871                 self.old_error_set.insert(t.id);
 872             }
 873         }
 874         intravisit::walk_ty(self, t)
 875     }
 876
 877     fn visit_variant(&mut self,
 878                      v: &'tcx hir::Variant,
 879                      g: &'tcx hir::Generics,
 880                      item_id: ast::NodeId) {
 881         if self.access_levels.is_reachable(v.node.data.id()) {
 882             self.in_variant = true;
 883             intravisit::walk_variant(self, v, g, item_id);
 884             self.in_variant = false;
 885         }
 886     }
 887
 888     fn visit_struct_field(&mut self, s: &'tcx hir::StructField) {
 889         if s.vis == hir::Public || self.in_variant {
 890             intravisit::walk_struct_field(self, s);
 891         }
 892     }
 893
 894     // we don't need to introspect into these at all: an
 895     // expression/block context can't possibly contain exported things.
 896     // (Making them no-ops stops us from traversing the whole AST without
 897     // having to be super careful about our `walk_...` calls above.)
 898     fn visit_block(&mut self, _: &'tcx hir::Block) {}
 899     fn visit_expr(&mut self, _: &'tcx hir::Expr) {}
 900 }
 901
 902 ///////////////////////////////////////////////////////////////////////////////
 903 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
 904 /// finds any private components in it.
 905 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
 906 /// and traits in public interfaces.
 907 ///////////////////////////////////////////////////////////////////////////////
 908
 909 struct SearchInterfaceForPrivateItemsVisitor<'a, 'tcx: 'a> {
 910     tcx: TyCtxt<'a, 'tcx, 'tcx>,
 911     item_def_id: DefId,
 912     span: Span,
 913     /// The visitor checks that each component type is at least this visible
 914     required_visibility: ty::Visibility,
 915     /// The visibility of the least visible component that has been visited
 916     min_visibility: ty::Visibility,
 917     has_old_errors: bool,
 918 }
 919
 920 impl<'a, 'tcx: 'a> SearchInterfaceForPrivateItemsVisitor<'a, 'tcx> {
 921     fn generics(&mut self) -> &mut Self {
 922         self.tcx.item_generics(self.item_def_id).visit_with(self);
 923         self
 924     }
 925
 926     fn predicates(&mut self) -> &mut Self {
 927         self.tcx.item_predicates(self.item_def_id).visit_with(self);
 928         self
 929     }
 930
 931     fn item_type(&mut self) -> &mut Self {
 932         self.tcx.item_type(self.item_def_id).visit_with(self);
 933         self
 934     }
 935
 936     fn impl_trait_ref(&mut self) -> &mut Self {
 937         self.tcx.impl_trait_ref(self.item_def_id).visit_with(self);
 938         self
 939     }
 940 }
 941
 942 impl<'a, 'tcx: 'a> TypeVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'a, 'tcx> {
 943     fn visit_ty(&mut self, ty: Ty<'tcx>) -> bool {
 944         let ty_def_id = match ty.sty {
 945             ty::TyAdt(adt, _) => Some(adt.did),
 946             ty::TyDynamic(ref obj, ..) => obj.principal().map(|p| p.def_id()),
 947             ty::TyProjection(ref proj) => {
 948                 if self.required_visibility == ty::Visibility::Invisible {
 949                     // Conservatively approximate the whole type alias as public without
 950                     // recursing into its components when determining impl publicity.
 951                     // For example, `impl <Type as Trait>::Alias {...}` may be a public impl
 952                     // even if both `Type` and `Trait` are private.
 953                     // Ideally, associated types should be substituted in the same way as
 954                     // free type aliases, but this isn't done yet.
 955                     return false;
 956                 }
 957
 958                 Some(proj.trait_ref.def_id)
 959             }
 960             _ => None
 961         };
 962
 963         if let Some(def_id) = ty_def_id {
 964             // Non-local means public (private items can't leave their crate, modulo bugs)
 965             if let Some(node_id) = self.tcx.hir.as_local_node_id(def_id) {
 966                 let item = self.tcx.hir.expect_item(node_id);
 967                 let vis = ty::Visibility::from_hir(&item.vis, node_id, self.tcx);
 968
 969                 if !vis.is_at_least(self.min_visibility, self.tcx) {
 970                     self.min_visibility = vis;
 971                 }
 972                 if !vis.is_at_least(self.required_visibility, self.tcx) {
 973                     if self.tcx.sess.features.borrow().pub_restricted || self.has_old_errors {
 974                         let mut err = struct_span_err!(self.tcx.sess, self.span, E0446,
 975                             "private type `{}` in public interface", ty);
 976                         err.span_label(self.span, &format!("can't leak private type"));
 977                         err.emit();
 978                     } else {
 979                         self.tcx.sess.add_lint(lint::builtin::PRIVATE_IN_PUBLIC,
 980                                                node_id,
 981                                                self.span,
 982                                                format!("private type `{}` in public \
 983                                                         interface (error E0446)", ty));
 984                     }
 985                 }
 986             }
 987         }
 988
 989         if let ty::TyProjection(ref proj) = ty.sty {
 990             // Avoid calling `visit_trait_ref` below on the trait,
 991             // as we have already checked the trait itself above.
 992             proj.trait_ref.super_visit_with(self)
 993         } else {
 994             ty.super_visit_with(self)
 995         }
 996     }
 997
 998     fn visit_trait_ref(&mut self, trait_ref: ty::TraitRef<'tcx>) -> bool {
 999         // Non-local means public (private items can't leave their crate, modulo bugs)
1000         if let Some(node_id) = self.tcx.hir.as_local_node_id(trait_ref.def_id) {
1001             let item = self.tcx.hir.expect_item(node_id);
1002             let vis = ty::Visibility::from_hir(&item.vis, node_id, self.tcx);
1003
1004             if !vis.is_at_least(self.min_visibility, self.tcx) {
1005                 self.min_visibility = vis;
1006             }
1007             if !vis.is_at_least(self.required_visibility, self.tcx) {
1008                 if self.tcx.sess.features.borrow().pub_restricted || self.has_old_errors {
1009                     struct_span_err!(self.tcx.sess, self.span, E0445,
1010                                      "private trait `{}` in public interface", trait_ref)
1011                         .span_label(self.span, &format!(
1012                                     "private trait can't be public"))
1013                         .emit();
1014                 } else {
1015                     self.tcx.sess.add_lint(lint::builtin::PRIVATE_IN_PUBLIC,
1016                                            node_id,
1017                                            self.span,
1018                                            format!("private trait `{}` in public \
1019                                                     interface (error E0445)", trait_ref));
1020                 }
1021             }
1022         }
1023
1024         trait_ref.super_visit_with(self)
1025     }
1026 }
1027
1028 struct PrivateItemsInPublicInterfacesVisitor<'a, 'tcx: 'a> {
1029     tcx: TyCtxt<'a, 'tcx, 'tcx>,
1030     old_error_set: &'a NodeSet,
1031     inner_visibility: ty::Visibility,
1032 }
1033
1034 impl<'a, 'tcx> PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1035     fn check(&self, item_id: ast::NodeId, required_visibility: ty::Visibility)
1036              -> SearchInterfaceForPrivateItemsVisitor<'a, 'tcx> {
1037         let mut has_old_errors = false;
1038
1039         // Slow path taken only if there any errors in the crate.
1040         for &id in self.old_error_set {
1041             // Walk up the nodes until we find `item_id` (or we hit a root).
1042             let mut id = id;
1043             loop {
1044                 if id == item_id {
1045                     has_old_errors = true;
1046                     break;
1047                 }
1048                 let parent = self.tcx.hir.get_parent_node(id);
1049                 if parent == id {
1050                     break;
1051                 }
1052                 id = parent;
1053             }
1054
1055             if has_old_errors {
1056                 break;
1057             }
1058         }
1059
1060         SearchInterfaceForPrivateItemsVisitor {
1061             tcx: self.tcx,
1062             item_def_id: self.tcx.hir.local_def_id(item_id),
1063             span: self.tcx.hir.span(item_id),
1064             min_visibility: ty::Visibility::Public,
1065             required_visibility: required_visibility,
1066             has_old_errors: has_old_errors,
1067         }
1068     }
1069 }
1070
1071 impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx> {
1072     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
1073         NestedVisitorMap::OnlyBodies(&self.tcx.hir)
1074     }
1075
1076     fn visit_item(&mut self, item: &'tcx hir::Item) {
1077         let tcx = self.tcx;
1078         let min = |vis1: ty::Visibility, vis2| {
1079             if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
1080         };
1081
1082         let item_visibility = ty::Visibility::from_hir(&item.vis, item.id, tcx);
1083
1084         match item.node {
1085             // Crates are always public
1086             hir::ItemExternCrate(..) => {}
1087             // All nested items are checked by visit_item
1088             hir::ItemMod(..) => {}
1089             // Checked in resolve
1090             hir::ItemUse(..) => {}
1091             // Subitems of these items have inherited publicity
1092             hir::ItemConst(..) | hir::ItemStatic(..) | hir::ItemFn(..) |
1093             hir::ItemTy(..) => {
1094                 self.check(item.id, item_visibility).generics().predicates().item_type();
1095
1096                 // Recurse for e.g. `impl Trait` (see `visit_ty`).
1097                 self.inner_visibility = item_visibility;
1098                 intravisit::walk_item(self, item);
1099             }
1100             hir::ItemTrait(.., ref trait_item_refs) => {
1101                 self.check(item.id, item_visibility).generics().predicates();
1102
1103                 for trait_item_ref in trait_item_refs {
1104                     let mut check = self.check(trait_item_ref.id.node_id, item_visibility);
1105                     check.generics().predicates();
1106
1107                     if trait_item_ref.kind == hir::AssociatedItemKind::Type &&
1108                        !trait_item_ref.defaultness.has_value() {
1109                         // No type to visit.
1110                     } else {
1111                         check.item_type();
1112                     }
1113                 }
1114             }
1115             hir::ItemEnum(ref def, _) => {
1116                 self.check(item.id, item_visibility).generics().predicates();
1117
1118                 for variant in &def.variants {
1119                     for field in variant.node.data.fields() {
1120                         self.check(field.id, item_visibility).item_type();
1121                     }
1122                 }
1123             }
1124             // Subitems of foreign modules have their own publicity
1125             hir::ItemForeignMod(ref foreign_mod) => {
1126                 for foreign_item in &foreign_mod.items {
1127                     let vis = ty::Visibility::from_hir(&foreign_item.vis, item.id, tcx);
1128                     self.check(foreign_item.id, vis).generics().predicates().item_type();
1129                 }
1130             }
1131             // Subitems of structs and unions have their own publicity
1132             hir::ItemStruct(ref struct_def, _) |
1133             hir::ItemUnion(ref struct_def, _) => {
1134                 self.check(item.id, item_visibility).generics().predicates();
1135
1136                 for field in struct_def.fields() {
1137                     let field_visibility = ty::Visibility::from_hir(&field.vis, item.id, tcx);
1138                     self.check(field.id, min(item_visibility, field_visibility)).item_type();
1139                 }
1140             }
1141             // The interface is empty
1142             hir::ItemDefaultImpl(..) => {}
1143             // An inherent impl is public when its type is public
1144             // Subitems of inherent impls have their own publicity
1145             hir::ItemImpl(.., None, _, ref impl_item_refs) => {
1146                 let ty_vis =
1147                     self.check(item.id, ty::Visibility::Invisible).item_type().min_visibility;
1148                 self.check(item.id, ty_vis).generics().predicates();
1149
1150                 for impl_item_ref in impl_item_refs {
1151                     let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1152                     let impl_item_vis =
1153                         ty::Visibility::from_hir(&impl_item.vis, item.id, tcx);
1154                     self.check(impl_item.id, min(impl_item_vis, ty_vis))
1155                         .generics().predicates().item_type();
1156
1157                     // Recurse for e.g. `impl Trait` (see `visit_ty`).
1158                     self.inner_visibility = impl_item_vis;
1159                     intravisit::walk_impl_item(self, impl_item);
1160                 }
1161             }
1162             // A trait impl is public when both its type and its trait are public
1163             // Subitems of trait impls have inherited publicity
1164             hir::ItemImpl(.., Some(_), _, ref impl_item_refs) => {
1165                 let vis = self.check(item.id, ty::Visibility::Invisible)
1166                               .item_type().impl_trait_ref().min_visibility;
1167                 self.check(item.id, vis).generics().predicates();
1168                 for impl_item_ref in impl_item_refs {
1169                     let impl_item = self.tcx.hir.impl_item(impl_item_ref.id);
1170                     self.check(impl_item.id, vis).generics().predicates().item_type();
1171
1172                     // Recurse for e.g. `impl Trait` (see `visit_ty`).
1173                     self.inner_visibility = vis;
1174                     intravisit::walk_impl_item(self, impl_item);
1175                 }
1176             }
1177         }
1178     }
1179
1180     fn visit_impl_item(&mut self, _impl_item: &'tcx hir::ImplItem) {
1181         // handled in `visit_item` above
1182     }
1183
1184     fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
1185         if let hir::TyImplTrait(..) = ty.node {
1186             // Check the traits being exposed, as they're separate,
1187             // e.g. `impl Iterator<Item=T>` has two predicates,
1188             // `X: Iterator` and `<X as Iterator>::Item == T`,
1189             // where `X` is the `impl Iterator<Item=T>` itself,
1190             // stored in `item_predicates`, not in the `Ty` itself.
1191             self.check(ty.id, self.inner_visibility).predicates();
1192         }
1193
1194         intravisit::walk_ty(self, ty);
1195     }
1196
1197     // Don't recurse into expressions in array sizes or const initializers
1198     fn visit_expr(&mut self, _: &'tcx hir::Expr) {}
1199     // Don't recurse into patterns in function arguments
1200     fn visit_pat(&mut self, _: &'tcx hir::Pat) {}
1201 }
1202
1203 pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1204                              export_map: &def::ExportMap)
1205                              -> AccessLevels {
1206     let _task = tcx.dep_graph.in_task(DepNode::Privacy);
1207
1208     let krate = tcx.hir.krate();
1209
1210     // Use the parent map to check the privacy of everything
1211     let mut visitor = PrivacyVisitor {
1212         curitem: DefId::local(CRATE_DEF_INDEX),
1213         in_foreign: false,
1214         tcx: tcx,
1215         tables: &ty::TypeckTables::empty(),
1216     };
1217     intravisit::walk_crate(&mut visitor, krate);
1218
1219     tcx.sess.abort_if_errors();
1220
1221     // Build up a set of all exported items in the AST. This is a set of all
1222     // items which are reachable from external crates based on visibility.
1223     let mut visitor = EmbargoVisitor {
1224         tcx: tcx,
1225         export_map: export_map,
1226         access_levels: Default::default(),
1227         prev_level: Some(AccessLevel::Public),
1228         changed: false,
1229     };
1230     loop {
1231         intravisit::walk_crate(&mut visitor, krate);
1232         if visitor.changed {
1233             visitor.changed = false;
1234         } else {
1235             break
1236         }
1237     }
1238     visitor.update(ast::CRATE_NODE_ID, Some(AccessLevel::Public));
1239
1240     {
1241         let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
1242             tcx: tcx,
1243             access_levels: &visitor.access_levels,
1244             in_variant: false,
1245             old_error_set: NodeSet(),
1246         };
1247         intravisit::walk_crate(&mut visitor, krate);
1248
1249         // Check for private types and traits in public interfaces
1250         let mut visitor = PrivateItemsInPublicInterfacesVisitor {
1251             tcx: tcx,
1252             old_error_set: &visitor.old_error_set,
1253             inner_visibility: ty::Visibility::Public,
1254         };
1255         krate.visit_all_item_likes(&mut DeepVisitor::new(&mut visitor));
1256     }
1257
1258     visitor.access_levels
1259 }
1260
1261 __build_diagnostic_array! { librustc_privacy, DIAGNOSTICS }