1 //! After we obtain a fresh AST fragment from a macro, code in this module helps to integrate
2 //! that fragment into the module structures that are already partially built.
4 //! Items from the fragment are placed into modules,
5 //! unexpanded macros in the fragment are visited and registered.
6 //! Imports are also considered items and placed into modules here, but not resolved yet.
8 use crate::def_collector::collect_definitions;
9 use crate::imports::ImportDirective;
10 use crate::imports::ImportDirectiveSubclass::{self, GlobImport, SingleImport};
11 use crate::macros::{LegacyBinding, LegacyScope};
12 use crate::Namespace::{self, MacroNS, TypeNS, ValueNS};
13 use crate::{CrateLint, Determinacy, PathResult, ResolutionError, VisResolutionError};
15 ExternPreludeEntry, ModuleOrUniformRoot, ParentScope, PerNS, Resolver, ResolverArenas,
17 use crate::{Module, ModuleData, ModuleKind, NameBinding, NameBindingKind, Segment, ToNameBinding};
20 use rustc::hir::def::{self, *};
21 use rustc::hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
22 use rustc::hir::exports::Export;
23 use rustc::middle::cstore::CrateStore;
25 use rustc_metadata::creader::LoadedMacro;
27 use rustc_data_structures::sync::Lrc;
31 use errors::Applicability;
33 use rustc_expand::base::SyntaxExtension;
34 use rustc_expand::expand::AstFragment;
35 use rustc_span::hygiene::{ExpnId, MacroKind};
36 use rustc_span::source_map::{respan, Spanned};
37 use rustc_span::symbol::{kw, sym};
38 use rustc_span::{Span, DUMMY_SP};
39 use syntax::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
40 use syntax::ast::{AssocItem, AssocItemKind, MetaItemKind, StmtKind};
41 use syntax::ast::{Ident, Name};
44 use syntax::token::{self, Token};
45 use syntax::visit::{self, Visitor};
49 use rustc_error_codes::*;
51 type Res = def::Res<NodeId>;
53 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, ExpnId) {
54 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
55 arenas.alloc_name_binding(NameBinding {
56 kind: NameBindingKind::Module(self.0),
65 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId) {
66 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
67 arenas.alloc_name_binding(NameBinding {
68 kind: NameBindingKind::Res(self.0, false),
79 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId, IsMacroExport) {
80 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
81 arenas.alloc_name_binding(NameBinding {
82 kind: NameBindingKind::Res(self.0, true),
91 impl<'a> Resolver<'a> {
92 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
93 /// otherwise, reports an error.
94 crate fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T)
98 let binding = def.to_name_binding(self.arenas);
99 let key = self.new_key(ident, ns);
100 if let Err(old_binding) = self.try_define(parent, key, binding) {
101 self.report_conflict(parent, ident, ns, old_binding, &binding);
105 crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
106 if def_id.krate == LOCAL_CRATE {
107 return self.module_map[&def_id];
110 if let Some(&module) = self.extern_module_map.get(&def_id) {
114 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
115 (self.cstore().crate_name_untracked(def_id.krate), None)
117 let def_key = self.cstore().def_key(def_id);
119 def_key.disambiguated_data.data.get_opt_name().unwrap(),
120 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })),
124 let kind = ModuleKind::Def(DefKind::Mod, def_id, name);
125 let module = self.arenas.alloc_module(ModuleData::new(
132 self.extern_module_map.insert(def_id, module);
136 crate fn macro_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> {
137 let def_id = match self.macro_defs.get(&expn_id) {
138 Some(def_id) => *def_id,
139 None => return self.ast_transform_scopes.get(&expn_id).unwrap_or(&self.graph_root),
141 if let Some(id) = self.definitions.as_local_node_id(def_id) {
142 self.local_macro_def_scopes[&id]
144 let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
145 self.get_module(module_def_id)
149 crate fn get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
151 Res::Def(DefKind::Macro(..), def_id) => self.get_macro_by_def_id(def_id),
152 Res::NonMacroAttr(attr_kind) => Some(self.non_macro_attr(attr_kind.is_used())),
157 crate fn get_macro_by_def_id(&mut self, def_id: DefId) -> Option<Lrc<SyntaxExtension>> {
158 if let Some(ext) = self.macro_map.get(&def_id) {
159 return Some(ext.clone());
162 let ext = Lrc::new(match self.cstore().load_macro_untracked(def_id, &self.session) {
163 LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition),
164 LoadedMacro::ProcMacro(ext) => ext,
167 self.macro_map.insert(def_id, ext.clone());
171 crate fn build_reduced_graph(
173 fragment: &AstFragment,
174 parent_scope: ParentScope<'a>,
175 ) -> LegacyScope<'a> {
176 collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
177 let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
178 fragment.visit_with(&mut visitor);
179 visitor.parent_scope.legacy
182 crate fn build_reduced_graph_external(&mut self, module: Module<'a>) {
183 let def_id = module.def_id().expect("unpopulated module without a def-id");
184 for child in self.cstore().item_children_untracked(def_id, self.session) {
185 let child = child.map_id(|_| panic!("unexpected id"));
186 BuildReducedGraphVisitor { r: self, parent_scope: ParentScope::module(module) }
187 .build_reduced_graph_for_external_crate_res(child);
192 struct BuildReducedGraphVisitor<'a, 'b> {
193 r: &'b mut Resolver<'a>,
194 parent_scope: ParentScope<'a>,
197 impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> {
198 fn as_mut(&mut self) -> &mut Resolver<'a> {
203 impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
204 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
205 self.resolve_visibility_speculative(vis, false).unwrap_or_else(|err| {
206 self.r.report_vis_error(err);
207 ty::Visibility::Public
211 fn resolve_visibility_speculative<'ast>(
213 vis: &'ast ast::Visibility,
215 ) -> Result<ty::Visibility, VisResolutionError<'ast>> {
216 let parent_scope = &self.parent_scope;
218 ast::VisibilityKind::Public => Ok(ty::Visibility::Public),
219 ast::VisibilityKind::Crate(..) => {
220 Ok(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)))
222 ast::VisibilityKind::Inherited => {
223 Ok(ty::Visibility::Restricted(parent_scope.module.normal_ancestor_id))
225 ast::VisibilityKind::Restricted { ref path, id, .. } => {
226 // For visibilities we are not ready to provide correct implementation of "uniform
227 // paths" right now, so on 2018 edition we only allow module-relative paths for now.
228 // On 2015 edition visibilities are resolved as crate-relative by default,
229 // so we are prepending a root segment if necessary.
230 let ident = path.segments.get(0).expect("empty path in visibility").ident;
231 let crate_root = if ident.is_path_segment_keyword() {
233 } else if ident.span.rust_2015() {
234 Some(Segment::from_ident(Ident::new(
236 path.span.shrink_to_lo().with_ctxt(ident.span.ctxt()),
239 return Err(VisResolutionError::Relative2018(ident.span, path));
242 let segments = crate_root
244 .chain(path.segments.iter().map(|seg| seg.into()))
245 .collect::<Vec<_>>();
246 let expected_found_error = |res| {
247 Err(VisResolutionError::ExpectedFound(
249 Segment::names_to_string(&segments),
253 match self.r.resolve_path(
259 CrateLint::SimplePath(id),
261 PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
262 let res = module.res().expect("visibility resolved to unnamed block");
264 self.r.record_partial_res(id, PartialRes::new(res));
266 if module.is_normal() {
268 Ok(ty::Visibility::Public)
270 let vis = ty::Visibility::Restricted(res.def_id());
271 if self.r.is_accessible_from(vis, parent_scope.module) {
274 Err(VisResolutionError::AncestorOnly(path.span))
278 expected_found_error(res)
281 PathResult::Module(..) => Err(VisResolutionError::ModuleOnly(path.span)),
282 PathResult::NonModule(partial_res) => {
283 expected_found_error(partial_res.base_res())
285 PathResult::Failed { span, label, suggestion, .. } => {
286 Err(VisResolutionError::FailedToResolve(span, label, suggestion))
288 PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
294 fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
295 let field_names = vdata
298 .map(|field| respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name)))
300 self.insert_field_names(def_id, field_names);
303 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Name>>) {
304 if !field_names.is_empty() {
305 self.r.field_names.insert(def_id, field_names);
309 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
310 // If any statements are items, we need to create an anonymous module
311 block.stmts.iter().any(|statement| match statement.kind {
312 StmtKind::Item(_) | StmtKind::Mac(_) => true,
317 // Add an import directive to the current module.
318 fn add_import_directive(
320 module_path: Vec<Segment>,
321 subclass: ImportDirectiveSubclass<'a>,
329 let current_module = self.parent_scope.module;
330 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
331 parent_scope: self.parent_scope,
333 imported_module: Cell::new(None),
338 use_span_with_attributes: item.span_with_attributes(),
339 has_attributes: !item.attrs.is_empty(),
343 used: Cell::new(false),
346 debug!("add_import_directive({:?})", directive);
348 self.r.indeterminate_imports.push(directive);
349 match directive.subclass {
350 // Don't add unresolved underscore imports to modules
351 SingleImport { target: Ident { name: kw::Underscore, .. }, .. } => {}
352 SingleImport { target, type_ns_only, .. } => {
353 self.r.per_ns(|this, ns| {
354 if !type_ns_only || ns == TypeNS {
355 let key = this.new_key(target, ns);
356 let mut resolution = this.resolution(current_module, key).borrow_mut();
357 resolution.add_single_import(directive);
361 // We don't add prelude imports to the globs since they only affect lexical scopes,
362 // which are not relevant to import resolution.
363 GlobImport { is_prelude: true, .. } => {}
364 GlobImport { .. } => current_module.globs.borrow_mut().push(directive),
369 fn build_reduced_graph_for_use_tree(
371 // This particular use tree
372 use_tree: &ast::UseTree,
374 parent_prefix: &[Segment],
376 // The whole `use` item
382 "build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})",
383 parent_prefix, use_tree, nested
386 let mut prefix_iter = parent_prefix
389 .chain(use_tree.prefix.segments.iter().map(|seg| seg.into()))
392 // On 2015 edition imports are resolved as crate-relative by default,
393 // so prefixes are prepended with crate root segment if necessary.
394 // The root is prepended lazily, when the first non-empty prefix or terminating glob
395 // appears, so imports in braced groups can have roots prepended independently.
396 let is_glob = if let ast::UseTreeKind::Glob = use_tree.kind { true } else { false };
397 let crate_root = match prefix_iter.peek() {
398 Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => {
399 Some(seg.ident.span.ctxt())
401 None if is_glob && use_tree.span.rust_2015() => Some(use_tree.span.ctxt()),
405 Segment::from_ident(Ident::new(
407 use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt),
411 let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>();
412 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
414 let empty_for_self = |prefix: &[Segment]| {
415 prefix.is_empty() || prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot
417 match use_tree.kind {
418 ast::UseTreeKind::Simple(rename, ..) => {
419 let mut ident = use_tree.ident();
420 let mut module_path = prefix;
421 let mut source = module_path.pop().unwrap();
422 let mut type_ns_only = false;
425 // Correctly handle `self`
426 if source.ident.name == kw::SelfLower {
429 if empty_for_self(&module_path) {
432 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix,
437 // Replace `use foo::self;` with `use foo;`
438 source = module_path.pop().unwrap();
439 if rename.is_none() {
440 ident = source.ident;
445 if source.ident.name == kw::SelfLower {
448 ResolutionError::SelfImportsOnlyAllowedWithin,
452 // Disallow `use $crate;`
453 if source.ident.name == kw::DollarCrate && module_path.is_empty() {
454 let crate_root = self.r.resolve_crate_root(source.ident);
455 let crate_name = match crate_root.kind {
456 ModuleKind::Def(.., name) => name,
457 ModuleKind::Block(..) => unreachable!(),
459 // HACK(eddyb) unclear how good this is, but keeping `$crate`
460 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
461 // while the current crate doesn't have a valid `crate_name`.
462 if crate_name != kw::Invalid {
463 // `crate_name` should not be interpreted as relative.
464 module_path.push(Segment {
465 ident: Ident { name: kw::PathRoot, span: source.ident.span },
466 id: Some(self.r.next_node_id()),
468 source.ident.name = crate_name;
470 if rename.is_none() {
471 ident.name = crate_name;
476 .struct_span_err(item.span, "`$crate` may not be imported")
481 if ident.name == kw::Crate {
482 self.r.session.span_err(
484 "crate root imports need to be explicitly named: \
485 `use crate as name;`",
489 let subclass = SingleImport {
490 source: source.ident,
492 source_bindings: PerNS {
493 type_ns: Cell::new(Err(Determinacy::Undetermined)),
494 value_ns: Cell::new(Err(Determinacy::Undetermined)),
495 macro_ns: Cell::new(Err(Determinacy::Undetermined)),
497 target_bindings: PerNS {
498 type_ns: Cell::new(None),
499 value_ns: Cell::new(None),
500 macro_ns: Cell::new(None),
505 self.add_import_directive(
516 ast::UseTreeKind::Glob => {
517 let subclass = GlobImport {
518 is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
519 max_vis: Cell::new(ty::Visibility::Invisible),
521 self.add_import_directive(
532 ast::UseTreeKind::Nested(ref items) => {
533 // Ensure there is at most one `self` in the list
534 let self_spans = items
536 .filter_map(|&(ref use_tree, _)| {
537 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
538 if use_tree.ident().name == kw::SelfLower {
539 return Some(use_tree.span);
545 .collect::<Vec<_>>();
546 if self_spans.len() > 1 {
547 let mut e = self.r.into_struct_error(
549 ResolutionError::SelfImportCanOnlyAppearOnceInTheList,
552 for other_span in self_spans.iter().skip(1) {
553 e.span_label(*other_span, "another `self` import appears here");
559 for &(ref tree, id) in items {
560 self.build_reduced_graph_for_use_tree(
561 // This particular use tree
562 tree, id, &prefix, true, // The whole `use` item
563 item, vis, root_span,
567 // Empty groups `a::b::{}` are turned into synthetic `self` imports
568 // `a::b::c::{self as _}`, so that their prefixes are correctly
569 // resolved and checked for privacy/stability/etc.
570 if items.is_empty() && !empty_for_self(&prefix) {
571 let new_span = prefix[prefix.len() - 1].ident.span;
572 let tree = ast::UseTree {
573 prefix: ast::Path::from_ident(Ident::new(kw::SelfLower, new_span)),
574 kind: ast::UseTreeKind::Simple(
575 Some(Ident::new(kw::Underscore, new_span)),
581 self.build_reduced_graph_for_use_tree(
582 // This particular use tree
587 // The whole `use` item
589 ty::Visibility::Invisible,
597 /// Constructs the reduced graph for one item.
598 fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
599 let parent_scope = &self.parent_scope;
600 let parent = parent_scope.module;
601 let expansion = parent_scope.expansion;
602 let ident = item.ident;
604 let vis = self.resolve_visibility(&item.vis);
607 ItemKind::Use(ref use_tree) => {
608 self.build_reduced_graph_for_use_tree(
609 // This particular use tree
614 // The whole `use` item
621 ItemKind::ExternCrate(orig_name) => {
622 let module = if orig_name.is_none() && ident.name == kw::SelfLower {
625 .struct_span_err(item.span, "`extern crate self;` requires renaming")
629 "extern crate self as name;".into(),
630 Applicability::HasPlaceholders,
634 } else if orig_name == Some(kw::SelfLower) {
638 self.r.crate_loader.process_extern_crate(item, &self.r.definitions);
639 self.r.extern_crate_map.insert(item.id, crate_id);
640 self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
643 let used = self.process_legacy_macro_imports(item, module);
645 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
646 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
649 parent_scope: self.parent_scope,
650 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
651 subclass: ImportDirectiveSubclass::ExternCrate {
655 has_attributes: !item.attrs.is_empty(),
656 use_span_with_attributes: item.span_with_attributes(),
658 root_span: item.span,
660 module_path: Vec::new(),
662 used: Cell::new(used),
664 self.r.potentially_unused_imports.push(directive);
665 let imported_binding = self.r.import(binding, directive);
666 if ptr::eq(parent, self.r.graph_root) {
667 if let Some(entry) = self.r.extern_prelude.get(&ident.modern()) {
668 if expansion != ExpnId::root()
669 && orig_name.is_some()
670 && entry.extern_crate_item.is_none()
672 let msg = "macro-expanded `extern crate` items cannot \
673 shadow names passed with `--extern`";
674 self.r.session.span_err(item.span, msg);
678 self.r.extern_prelude.entry(ident.modern()).or_insert(ExternPreludeEntry {
679 extern_crate_item: None,
680 introduced_by_item: true,
682 entry.extern_crate_item = Some(imported_binding);
683 if orig_name.is_some() {
684 entry.introduced_by_item = true;
687 self.r.define(parent, ident, TypeNS, imported_binding);
690 ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
692 ItemKind::Mod(..) => {
693 let def_id = self.r.definitions.local_def_id(item.id);
694 let module_kind = ModuleKind::Def(DefKind::Mod, def_id, ident.name);
695 let module = self.r.arenas.alloc_module(ModuleData {
696 no_implicit_prelude: parent.no_implicit_prelude || {
697 attr::contains_name(&item.attrs, sym::no_implicit_prelude)
699 ..ModuleData::new(Some(parent), module_kind, def_id, expansion, item.span)
701 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
702 self.r.module_map.insert(def_id, module);
704 // Descend into the module.
705 self.parent_scope.module = module;
708 // These items live in the value namespace.
709 ItemKind::Static(..) => {
710 let res = Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id));
711 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
713 ItemKind::Const(..) => {
714 let res = Res::Def(DefKind::Const, self.r.definitions.local_def_id(item.id));
715 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
717 ItemKind::Fn(..) => {
718 let res = Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id));
719 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
721 // Functions introducing procedural macros reserve a slot
722 // in the macro namespace as well (see #52225).
723 self.define_macro(item);
726 // These items live in the type namespace.
727 ItemKind::TyAlias(ref ty, _) => {
728 let def_kind = match ty.kind.opaque_top_hack() {
729 None => DefKind::TyAlias,
730 Some(_) => DefKind::OpaqueTy,
732 let res = Res::Def(def_kind, self.r.definitions.local_def_id(item.id));
733 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
736 ItemKind::Enum(_, _) => {
737 let def_id = self.r.definitions.local_def_id(item.id);
738 self.r.variant_vis.insert(def_id, vis);
739 let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
740 let module = self.r.new_module(
743 parent.normal_ancestor_id,
747 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
748 self.parent_scope.module = module;
751 ItemKind::TraitAlias(..) => {
752 let res = Res::Def(DefKind::TraitAlias, self.r.definitions.local_def_id(item.id));
753 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
756 // These items live in both the type and value namespaces.
757 ItemKind::Struct(ref vdata, _) => {
758 // Define a name in the type namespace.
759 let def_id = self.r.definitions.local_def_id(item.id);
760 let res = Res::Def(DefKind::Struct, def_id);
761 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
763 // Record field names for error reporting.
764 self.insert_field_names_local(def_id, vdata);
766 // If this is a tuple or unit struct, define a name
767 // in the value namespace as well.
768 if let Some(ctor_node_id) = vdata.ctor_id() {
769 let mut ctor_vis = vis;
770 // If the structure is marked as non_exhaustive then lower the visibility
771 // to within the crate.
772 if vis == ty::Visibility::Public
773 && attr::contains_name(&item.attrs, sym::non_exhaustive)
775 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
777 for field in vdata.fields() {
778 // NOTE: The field may be an expansion placeholder, but expansion sets
779 // correct visibilities for unnamed field placeholders specifically, so the
780 // constructor visibility should still be determined correctly.
781 if let Ok(field_vis) = self.resolve_visibility_speculative(&field.vis, true)
783 if ctor_vis.is_at_least(field_vis, &*self.r) {
784 ctor_vis = field_vis;
788 let ctor_res = Res::Def(
789 DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(vdata)),
790 self.r.definitions.local_def_id(ctor_node_id),
792 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
793 self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis));
797 ItemKind::Union(ref vdata, _) => {
798 let def_id = self.r.definitions.local_def_id(item.id);
799 let res = Res::Def(DefKind::Union, def_id);
800 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
802 // Record field names for error reporting.
803 self.insert_field_names_local(def_id, vdata);
806 ItemKind::Trait(..) => {
807 let def_id = self.r.definitions.local_def_id(item.id);
809 // Add all the items within to a new module.
810 let module_kind = ModuleKind::Def(DefKind::Trait, def_id, ident.name);
811 let module = self.r.new_module(
814 parent.normal_ancestor_id,
818 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
819 self.parent_scope.module = module;
822 // These items do not add names to modules.
823 ItemKind::Impl(..) | ItemKind::ForeignMod(..) | ItemKind::GlobalAsm(..) => {}
825 ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
829 /// Constructs the reduced graph for one foreign item.
830 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
831 let (res, ns) = match item.kind {
832 ForeignItemKind::Fn(..) => {
833 (Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id)), ValueNS)
835 ForeignItemKind::Static(..) => {
836 (Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id)), ValueNS)
838 ForeignItemKind::Ty => {
839 (Res::Def(DefKind::ForeignTy, self.r.definitions.local_def_id(item.id)), TypeNS)
841 ForeignItemKind::Macro(_) => unreachable!(),
843 let parent = self.parent_scope.module;
844 let expansion = self.parent_scope.expansion;
845 let vis = self.resolve_visibility(&item.vis);
846 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
849 fn build_reduced_graph_for_block(&mut self, block: &Block) {
850 let parent = self.parent_scope.module;
851 let expansion = self.parent_scope.expansion;
852 if self.block_needs_anonymous_module(block) {
853 let module = self.r.new_module(
855 ModuleKind::Block(block.id),
856 parent.normal_ancestor_id,
860 self.r.block_map.insert(block.id, module);
861 self.parent_scope.module = module; // Descend into the block.
865 /// Builds the reduced graph for a single item in an external crate.
866 fn build_reduced_graph_for_external_crate_res(&mut self, child: Export<NodeId>) {
867 let parent = self.parent_scope.module;
868 let Export { ident, res, vis, span } = child;
869 let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
870 // Record primary definitions.
872 Res::Def(kind @ DefKind::Mod, def_id)
873 | Res::Def(kind @ DefKind::Enum, def_id)
874 | Res::Def(kind @ DefKind::Trait, def_id) => {
875 let module = self.r.new_module(
877 ModuleKind::Def(kind, def_id, ident.name),
882 self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
884 Res::Def(DefKind::Struct, _)
885 | Res::Def(DefKind::Union, _)
886 | Res::Def(DefKind::Variant, _)
887 | Res::Def(DefKind::TyAlias, _)
888 | Res::Def(DefKind::ForeignTy, _)
889 | Res::Def(DefKind::OpaqueTy, _)
890 | Res::Def(DefKind::TraitAlias, _)
891 | Res::Def(DefKind::AssocTy, _)
892 | Res::Def(DefKind::AssocOpaqueTy, _)
894 | Res::ToolMod => self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
895 Res::Def(DefKind::Fn, _)
896 | Res::Def(DefKind::Method, _)
897 | Res::Def(DefKind::Static, _)
898 | Res::Def(DefKind::Const, _)
899 | Res::Def(DefKind::AssocConst, _)
900 | Res::Def(DefKind::Ctor(..), _) => {
901 self.r.define(parent, ident, ValueNS, (res, vis, span, expansion))
903 Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
904 self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
906 Res::Def(DefKind::TyParam, _)
907 | Res::Def(DefKind::ConstParam, _)
911 | Res::Err => bug!("unexpected resolution: {:?}", res),
913 // Record some extra data for better diagnostics.
914 let cstore = self.r.cstore();
916 Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
917 let field_names = cstore.struct_field_names_untracked(def_id, self.r.session);
918 self.insert_field_names(def_id, field_names);
920 Res::Def(DefKind::Method, def_id) => {
921 if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
922 self.r.has_self.insert(def_id);
925 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
926 let parent = cstore.def_key(def_id).parent;
927 if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
928 self.r.struct_constructors.insert(struct_def_id, (res, vis));
935 fn legacy_import_macro(
938 binding: &'a NameBinding<'a>,
940 allow_shadowing: bool,
942 if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
943 let msg = format!("`{}` is already in scope", name);
945 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
946 self.r.session.struct_span_err(span, &msg).note(note).emit();
950 /// Returns `true` if we should consider the underlying `extern crate` to be used.
951 fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
952 let mut import_all = None;
953 let mut single_imports = Vec::new();
954 for attr in &item.attrs {
955 if attr.check_name(sym::macro_use) {
956 if self.parent_scope.module.parent.is_some() {
961 "an `extern crate` loading macros must be at the crate root"
964 if let ItemKind::ExternCrate(Some(orig_name)) = item.kind {
965 if orig_name == kw::SelfLower {
966 self.r.session.span_err(
968 "`macro_use` is not supported on `extern crate self`",
972 let ill_formed = |span| span_err!(self.r.session, span, E0466, "bad macro import");
974 Some(meta) => match meta.kind {
975 MetaItemKind::Word => {
976 import_all = Some(meta.span);
979 MetaItemKind::List(nested_metas) => {
980 for nested_meta in nested_metas {
981 match nested_meta.ident() {
982 Some(ident) if nested_meta.is_word() => {
983 single_imports.push(ident)
985 _ => ill_formed(nested_meta.span()),
989 MetaItemKind::NameValue(..) => ill_formed(meta.span),
991 None => ill_formed(attr.span),
996 let macro_use_directive = |this: &Self, span| {
997 this.r.arenas.alloc_import_directive(ImportDirective {
1000 parent_scope: this.parent_scope,
1001 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
1002 subclass: ImportDirectiveSubclass::MacroUse,
1003 use_span_with_attributes: item.span_with_attributes(),
1004 has_attributes: !item.attrs.is_empty(),
1005 use_span: item.span,
1008 module_path: Vec::new(),
1009 vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
1010 used: Cell::new(false),
1014 let allow_shadowing = self.parent_scope.expansion == ExpnId::root();
1015 if let Some(span) = import_all {
1016 let directive = macro_use_directive(self, span);
1017 self.r.potentially_unused_imports.push(directive);
1018 module.for_each_child(self, |this, ident, ns, binding| {
1020 let imported_binding = this.r.import(binding, directive);
1021 this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
1025 for ident in single_imports.iter().cloned() {
1026 let result = self.r.resolve_ident_in_module(
1027 ModuleOrUniformRoot::Module(module),
1034 if let Ok(binding) = result {
1035 let directive = macro_use_directive(self, ident.span);
1036 self.r.potentially_unused_imports.push(directive);
1037 let imported_binding = self.r.import(binding, directive);
1038 self.legacy_import_macro(
1045 span_err!(self.r.session, ident.span, E0469, "imported macro not found");
1049 import_all.is_some() || !single_imports.is_empty()
1052 /// Returns `true` if this attribute list contains `macro_use`.
1053 fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool {
1055 if attr.check_name(sym::macro_escape) {
1056 let msg = "macro_escape is a deprecated synonym for macro_use";
1057 let mut err = self.r.session.struct_span_warn(attr.span, msg);
1058 if let ast::AttrStyle::Inner = attr.style {
1059 err.help("consider an outer attribute, `#[macro_use]` mod ...").emit();
1063 } else if !attr.check_name(sym::macro_use) {
1067 if !attr.is_word() {
1068 self.r.session.span_err(attr.span, "arguments to macro_use are not allowed here");
1076 fn visit_invoc(&mut self, id: NodeId) -> LegacyScope<'a> {
1077 let invoc_id = id.placeholder_to_expn_id();
1079 self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id);
1081 let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope);
1082 assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation");
1084 LegacyScope::Invocation(invoc_id)
1087 fn proc_macro_stub(item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
1088 if attr::contains_name(&item.attrs, sym::proc_macro) {
1089 return Some((MacroKind::Bang, item.ident, item.span));
1090 } else if attr::contains_name(&item.attrs, sym::proc_macro_attribute) {
1091 return Some((MacroKind::Attr, item.ident, item.span));
1092 } else if let Some(attr) = attr::find_by_name(&item.attrs, sym::proc_macro_derive) {
1093 if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
1094 if let Some(ident) = nested_meta.ident() {
1095 return Some((MacroKind::Derive, ident, ident.span));
1102 // Mark the given macro as unused unless its name starts with `_`.
1103 // Macro uses will remove items from this set, and the remaining
1104 // items will be reported as `unused_macros`.
1105 fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) {
1106 if !ident.as_str().starts_with("_") {
1107 self.r.unused_macros.insert(node_id, span);
1111 fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> {
1112 let parent_scope = self.parent_scope;
1113 let expansion = parent_scope.expansion;
1114 let (ext, ident, span, is_legacy) = match &item.kind {
1115 ItemKind::MacroDef(def) => {
1116 let ext = Lrc::new(self.r.compile_macro(item, self.r.session.edition()));
1117 (ext, item.ident, item.span, def.legacy)
1119 ItemKind::Fn(..) => match Self::proc_macro_stub(item) {
1120 Some((macro_kind, ident, span)) => {
1121 self.r.proc_macro_stubs.insert(item.id);
1122 (self.r.dummy_ext(macro_kind), ident, span, false)
1124 None => return parent_scope.legacy,
1126 _ => unreachable!(),
1129 let def_id = self.r.definitions.local_def_id(item.id);
1130 let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id);
1131 self.r.macro_map.insert(def_id, ext);
1132 self.r.local_macro_def_scopes.insert(item.id, parent_scope.module);
1135 let ident = ident.modern();
1136 self.r.macro_names.insert(ident);
1137 let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
1138 let vis = if is_macro_export {
1139 ty::Visibility::Public
1141 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
1143 let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas);
1144 self.r.set_binding_parent_module(binding, parent_scope.module);
1145 self.r.all_macros.insert(ident.name, res);
1146 if is_macro_export {
1147 let module = self.r.graph_root;
1148 self.r.define(module, ident, MacroNS, (res, vis, span, expansion, IsMacroExport));
1150 self.r.check_reserved_macro_name(ident, res);
1151 self.insert_unused_macro(ident, item.id, span);
1153 LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding {
1154 parent_legacy_scope: parent_scope.legacy,
1159 let module = parent_scope.module;
1160 let vis = self.resolve_visibility(&item.vis);
1161 if vis != ty::Visibility::Public {
1162 self.insert_unused_macro(ident, item.id, span);
1164 self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
1165 self.parent_scope.legacy
1170 macro_rules! method {
1171 ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => {
1172 fn $visit(&mut self, node: &'b $ty) {
1173 if let $invoc(..) = node.kind {
1174 self.visit_invoc(node.id);
1176 visit::$walk(self, node);
1182 impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
1183 method!(visit_expr: ast::Expr, ast::ExprKind::Mac, walk_expr);
1184 method!(visit_pat: ast::Pat, ast::PatKind::Mac, walk_pat);
1185 method!(visit_ty: ast::Ty, ast::TyKind::Mac, walk_ty);
1187 fn visit_item(&mut self, item: &'b Item) {
1188 let macro_use = match item.kind {
1189 ItemKind::MacroDef(..) => {
1190 self.parent_scope.legacy = self.define_macro(item);
1193 ItemKind::Mac(..) => {
1194 self.parent_scope.legacy = self.visit_invoc(item.id);
1197 ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
1200 let orig_current_module = self.parent_scope.module;
1201 let orig_current_legacy_scope = self.parent_scope.legacy;
1202 self.build_reduced_graph_for_item(item);
1203 visit::walk_item(self, item);
1204 self.parent_scope.module = orig_current_module;
1206 self.parent_scope.legacy = orig_current_legacy_scope;
1210 fn visit_stmt(&mut self, stmt: &'b ast::Stmt) {
1211 if let ast::StmtKind::Mac(..) = stmt.kind {
1212 self.parent_scope.legacy = self.visit_invoc(stmt.id);
1214 visit::walk_stmt(self, stmt);
1218 fn visit_foreign_item(&mut self, foreign_item: &'b ForeignItem) {
1219 if let ForeignItemKind::Macro(_) = foreign_item.kind {
1220 self.visit_invoc(foreign_item.id);
1224 self.build_reduced_graph_for_foreign_item(foreign_item);
1225 visit::walk_foreign_item(self, foreign_item);
1228 fn visit_block(&mut self, block: &'b Block) {
1229 let orig_current_module = self.parent_scope.module;
1230 let orig_current_legacy_scope = self.parent_scope.legacy;
1231 self.build_reduced_graph_for_block(block);
1232 visit::walk_block(self, block);
1233 self.parent_scope.module = orig_current_module;
1234 self.parent_scope.legacy = orig_current_legacy_scope;
1237 fn visit_trait_item(&mut self, item: &'b AssocItem) {
1238 let parent = self.parent_scope.module;
1240 if let AssocItemKind::Macro(_) = item.kind {
1241 self.visit_invoc(item.id);
1245 // Add the item to the trait info.
1246 let item_def_id = self.r.definitions.local_def_id(item.id);
1247 let (res, ns) = match item.kind {
1248 AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
1249 AssocItemKind::Fn(ref sig, _) => {
1250 if sig.decl.has_self() {
1251 self.r.has_self.insert(item_def_id);
1253 (Res::Def(DefKind::Method, item_def_id), ValueNS)
1255 AssocItemKind::TyAlias(..) => (Res::Def(DefKind::AssocTy, item_def_id), TypeNS),
1256 AssocItemKind::Macro(_) => bug!(), // handled above
1259 let vis = ty::Visibility::Public;
1260 let expansion = self.parent_scope.expansion;
1261 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
1263 visit::walk_trait_item(self, item);
1266 fn visit_impl_item(&mut self, item: &'b ast::AssocItem) {
1267 if let ast::AssocItemKind::Macro(..) = item.kind {
1268 self.visit_invoc(item.id);
1270 self.resolve_visibility(&item.vis);
1271 visit::walk_impl_item(self, item);
1275 fn visit_token(&mut self, t: Token) {
1276 if let token::Interpolated(nt) = t.kind {
1277 if let token::NtExpr(ref expr) = *nt {
1278 if let ast::ExprKind::Mac(..) = expr.kind {
1279 self.visit_invoc(expr.id);
1285 fn visit_attribute(&mut self, attr: &'b ast::Attribute) {
1286 if !attr.is_doc_comment() && attr::is_builtin_attr(attr) {
1289 .push((attr.get_normal_item().path.segments[0].ident, self.parent_scope));
1291 visit::walk_attribute(self, attr);
1294 fn visit_arm(&mut self, arm: &'b ast::Arm) {
1295 if arm.is_placeholder {
1296 self.visit_invoc(arm.id);
1298 visit::walk_arm(self, arm);
1302 fn visit_field(&mut self, f: &'b ast::Field) {
1303 if f.is_placeholder {
1304 self.visit_invoc(f.id);
1306 visit::walk_field(self, f);
1310 fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
1311 if fp.is_placeholder {
1312 self.visit_invoc(fp.id);
1314 visit::walk_field_pattern(self, fp);
1318 fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
1319 if param.is_placeholder {
1320 self.visit_invoc(param.id);
1322 visit::walk_generic_param(self, param);
1326 fn visit_param(&mut self, p: &'b ast::Param) {
1327 if p.is_placeholder {
1328 self.visit_invoc(p.id);
1330 visit::walk_param(self, p);
1334 fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
1335 if sf.is_placeholder {
1336 self.visit_invoc(sf.id);
1338 self.resolve_visibility(&sf.vis);
1339 visit::walk_struct_field(self, sf);
1343 // Constructs the reduced graph for one variant. Variants exist in the
1344 // type and value namespaces.
1345 fn visit_variant(&mut self, variant: &'b ast::Variant) {
1346 if variant.is_placeholder {
1347 self.visit_invoc(variant.id);
1351 let parent = self.parent_scope.module;
1352 let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
1353 let expn_id = self.parent_scope.expansion;
1354 let ident = variant.ident;
1356 // Define a name in the type namespace.
1357 let def_id = self.r.definitions.local_def_id(variant.id);
1358 let res = Res::Def(DefKind::Variant, def_id);
1359 self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
1361 // If the variant is marked as non_exhaustive then lower the visibility to within the
1363 let mut ctor_vis = vis;
1364 let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
1365 if has_non_exhaustive && vis == ty::Visibility::Public {
1366 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
1369 // Define a constructor name in the value namespace.
1370 // Braced variants, unlike structs, generate unusable names in
1371 // value namespace, they are reserved for possible future use.
1372 // It's ok to use the variant's id as a ctor id since an
1373 // error will be reported on any use of such resolution anyway.
1374 let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
1375 let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
1376 let ctor_kind = CtorKind::from_ast(&variant.data);
1377 let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1378 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
1380 visit::walk_variant(self, variant);