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::exports::Export;
21 use rustc::middle::cstore::CrateStore;
23 use rustc_hir::def::{self, *};
24 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
25 use rustc_metadata::creader::LoadedMacro;
27 use rustc_data_structures::sync::Lrc;
31 use errors::{struct_span_err, 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};
43 use syntax::token::{self, Token};
44 use syntax::visit::{self, Visitor};
48 use rustc_error_codes::*;
50 type Res = def::Res<NodeId>;
52 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, ExpnId) {
53 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
54 arenas.alloc_name_binding(NameBinding {
55 kind: NameBindingKind::Module(self.0),
64 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId) {
65 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
66 arenas.alloc_name_binding(NameBinding {
67 kind: NameBindingKind::Res(self.0, false),
78 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId, IsMacroExport) {
79 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
80 arenas.alloc_name_binding(NameBinding {
81 kind: NameBindingKind::Res(self.0, true),
90 impl<'a> Resolver<'a> {
91 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
92 /// otherwise, reports an error.
93 crate fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T)
97 let binding = def.to_name_binding(self.arenas);
98 let key = self.new_key(ident, ns);
99 if let Err(old_binding) = self.try_define(parent, key, binding) {
100 self.report_conflict(parent, ident, ns, old_binding, &binding);
104 crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
105 if def_id.krate == LOCAL_CRATE {
106 return self.module_map[&def_id];
109 if let Some(&module) = self.extern_module_map.get(&def_id) {
113 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
114 (self.cstore().crate_name_untracked(def_id.krate), None)
116 let def_key = self.cstore().def_key(def_id);
118 def_key.disambiguated_data.data.get_opt_name().unwrap(),
119 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })),
123 let kind = ModuleKind::Def(DefKind::Mod, def_id, name);
124 let module = self.arenas.alloc_module(ModuleData::new(
131 self.extern_module_map.insert(def_id, module);
135 crate fn macro_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> {
136 let def_id = match self.macro_defs.get(&expn_id) {
137 Some(def_id) => *def_id,
138 None => return self.ast_transform_scopes.get(&expn_id).unwrap_or(&self.graph_root),
140 if let Some(id) = self.definitions.as_local_node_id(def_id) {
141 self.local_macro_def_scopes[&id]
143 let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
144 self.get_module(module_def_id)
148 crate fn get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
150 Res::Def(DefKind::Macro(..), def_id) => self.get_macro_by_def_id(def_id),
151 Res::NonMacroAttr(attr_kind) => Some(self.non_macro_attr(attr_kind.is_used())),
156 crate fn get_macro_by_def_id(&mut self, def_id: DefId) -> Option<Lrc<SyntaxExtension>> {
157 if let Some(ext) = self.macro_map.get(&def_id) {
158 return Some(ext.clone());
161 let ext = Lrc::new(match self.cstore().load_macro_untracked(def_id, &self.session) {
162 LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition),
163 LoadedMacro::ProcMacro(ext) => ext,
166 self.macro_map.insert(def_id, ext.clone());
170 crate fn build_reduced_graph(
172 fragment: &AstFragment,
173 parent_scope: ParentScope<'a>,
174 ) -> LegacyScope<'a> {
175 collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
176 let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
177 fragment.visit_with(&mut visitor);
178 visitor.parent_scope.legacy
181 crate fn build_reduced_graph_external(&mut self, module: Module<'a>) {
182 let def_id = module.def_id().expect("unpopulated module without a def-id");
183 for child in self.cstore().item_children_untracked(def_id, self.session) {
184 let child = child.map_id(|_| panic!("unexpected id"));
185 BuildReducedGraphVisitor { r: self, parent_scope: ParentScope::module(module) }
186 .build_reduced_graph_for_external_crate_res(child);
191 struct BuildReducedGraphVisitor<'a, 'b> {
192 r: &'b mut Resolver<'a>,
193 parent_scope: ParentScope<'a>,
196 impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> {
197 fn as_mut(&mut self) -> &mut Resolver<'a> {
202 impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
203 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
204 self.resolve_visibility_speculative(vis, false).unwrap_or_else(|err| {
205 self.r.report_vis_error(err);
206 ty::Visibility::Public
210 fn resolve_visibility_speculative<'ast>(
212 vis: &'ast ast::Visibility,
214 ) -> Result<ty::Visibility, VisResolutionError<'ast>> {
215 let parent_scope = &self.parent_scope;
217 ast::VisibilityKind::Public => Ok(ty::Visibility::Public),
218 ast::VisibilityKind::Crate(..) => {
219 Ok(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)))
221 ast::VisibilityKind::Inherited => {
222 Ok(ty::Visibility::Restricted(parent_scope.module.normal_ancestor_id))
224 ast::VisibilityKind::Restricted { ref path, id, .. } => {
225 // For visibilities we are not ready to provide correct implementation of "uniform
226 // paths" right now, so on 2018 edition we only allow module-relative paths for now.
227 // On 2015 edition visibilities are resolved as crate-relative by default,
228 // so we are prepending a root segment if necessary.
229 let ident = path.segments.get(0).expect("empty path in visibility").ident;
230 let crate_root = if ident.is_path_segment_keyword() {
232 } else if ident.span.rust_2015() {
233 Some(Segment::from_ident(Ident::new(
235 path.span.shrink_to_lo().with_ctxt(ident.span.ctxt()),
238 return Err(VisResolutionError::Relative2018(ident.span, path));
241 let segments = crate_root
243 .chain(path.segments.iter().map(|seg| seg.into()))
244 .collect::<Vec<_>>();
245 let expected_found_error = |res| {
246 Err(VisResolutionError::ExpectedFound(
248 Segment::names_to_string(&segments),
252 match self.r.resolve_path(
258 CrateLint::SimplePath(id),
260 PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
261 let res = module.res().expect("visibility resolved to unnamed block");
263 self.r.record_partial_res(id, PartialRes::new(res));
265 if module.is_normal() {
267 Ok(ty::Visibility::Public)
269 let vis = ty::Visibility::Restricted(res.def_id());
270 if self.r.is_accessible_from(vis, parent_scope.module) {
273 Err(VisResolutionError::AncestorOnly(path.span))
277 expected_found_error(res)
280 PathResult::Module(..) => Err(VisResolutionError::ModuleOnly(path.span)),
281 PathResult::NonModule(partial_res) => {
282 expected_found_error(partial_res.base_res())
284 PathResult::Failed { span, label, suggestion, .. } => {
285 Err(VisResolutionError::FailedToResolve(span, label, suggestion))
287 PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
293 fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
294 let field_names = vdata
297 .map(|field| respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name)))
299 self.insert_field_names(def_id, field_names);
302 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Name>>) {
303 if !field_names.is_empty() {
304 self.r.field_names.insert(def_id, field_names);
308 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
309 // If any statements are items, we need to create an anonymous module
310 block.stmts.iter().any(|statement| match statement.kind {
311 StmtKind::Item(_) | StmtKind::Mac(_) => true,
316 // Add an import directive to the current module.
317 fn add_import_directive(
319 module_path: Vec<Segment>,
320 subclass: ImportDirectiveSubclass<'a>,
328 let current_module = self.parent_scope.module;
329 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
330 parent_scope: self.parent_scope,
332 imported_module: Cell::new(None),
337 use_span_with_attributes: item.span_with_attributes(),
338 has_attributes: !item.attrs.is_empty(),
342 used: Cell::new(false),
345 debug!("add_import_directive({:?})", directive);
347 self.r.indeterminate_imports.push(directive);
348 match directive.subclass {
349 // Don't add unresolved underscore imports to modules
350 SingleImport { target: Ident { name: kw::Underscore, .. }, .. } => {}
351 SingleImport { target, type_ns_only, .. } => {
352 self.r.per_ns(|this, ns| {
353 if !type_ns_only || ns == TypeNS {
354 let key = this.new_key(target, ns);
355 let mut resolution = this.resolution(current_module, key).borrow_mut();
356 resolution.add_single_import(directive);
360 // We don't add prelude imports to the globs since they only affect lexical scopes,
361 // which are not relevant to import resolution.
362 GlobImport { is_prelude: true, .. } => {}
363 GlobImport { .. } => current_module.globs.borrow_mut().push(directive),
368 fn build_reduced_graph_for_use_tree(
370 // This particular use tree
371 use_tree: &ast::UseTree,
373 parent_prefix: &[Segment],
375 // The whole `use` item
381 "build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})",
382 parent_prefix, use_tree, nested
385 let mut prefix_iter = parent_prefix
388 .chain(use_tree.prefix.segments.iter().map(|seg| seg.into()))
391 // On 2015 edition imports are resolved as crate-relative by default,
392 // so prefixes are prepended with crate root segment if necessary.
393 // The root is prepended lazily, when the first non-empty prefix or terminating glob
394 // appears, so imports in braced groups can have roots prepended independently.
395 let is_glob = if let ast::UseTreeKind::Glob = use_tree.kind { true } else { false };
396 let crate_root = match prefix_iter.peek() {
397 Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => {
398 Some(seg.ident.span.ctxt())
400 None if is_glob && use_tree.span.rust_2015() => Some(use_tree.span.ctxt()),
404 Segment::from_ident(Ident::new(
406 use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt),
410 let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>();
411 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
413 let empty_for_self = |prefix: &[Segment]| {
414 prefix.is_empty() || prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot
416 match use_tree.kind {
417 ast::UseTreeKind::Simple(rename, ..) => {
418 let mut ident = use_tree.ident();
419 let mut module_path = prefix;
420 let mut source = module_path.pop().unwrap();
421 let mut type_ns_only = false;
424 // Correctly handle `self`
425 if source.ident.name == kw::SelfLower {
428 if empty_for_self(&module_path) {
431 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix,
436 // Replace `use foo::self;` with `use foo;`
437 source = module_path.pop().unwrap();
438 if rename.is_none() {
439 ident = source.ident;
444 if source.ident.name == kw::SelfLower {
447 ResolutionError::SelfImportsOnlyAllowedWithin,
451 // Disallow `use $crate;`
452 if source.ident.name == kw::DollarCrate && module_path.is_empty() {
453 let crate_root = self.r.resolve_crate_root(source.ident);
454 let crate_name = match crate_root.kind {
455 ModuleKind::Def(.., name) => name,
456 ModuleKind::Block(..) => unreachable!(),
458 // HACK(eddyb) unclear how good this is, but keeping `$crate`
459 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
460 // while the current crate doesn't have a valid `crate_name`.
461 if crate_name != kw::Invalid {
462 // `crate_name` should not be interpreted as relative.
463 module_path.push(Segment {
464 ident: Ident { name: kw::PathRoot, span: source.ident.span },
465 id: Some(self.r.next_node_id()),
467 source.ident.name = crate_name;
469 if rename.is_none() {
470 ident.name = crate_name;
475 .struct_span_err(item.span, "`$crate` may not be imported")
480 if ident.name == kw::Crate {
481 self.r.session.span_err(
483 "crate root imports need to be explicitly named: \
484 `use crate as name;`",
488 let subclass = SingleImport {
489 source: source.ident,
491 source_bindings: PerNS {
492 type_ns: Cell::new(Err(Determinacy::Undetermined)),
493 value_ns: Cell::new(Err(Determinacy::Undetermined)),
494 macro_ns: Cell::new(Err(Determinacy::Undetermined)),
496 target_bindings: PerNS {
497 type_ns: Cell::new(None),
498 value_ns: Cell::new(None),
499 macro_ns: Cell::new(None),
504 self.add_import_directive(
515 ast::UseTreeKind::Glob => {
516 let subclass = GlobImport {
517 is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
518 max_vis: Cell::new(ty::Visibility::Invisible),
520 self.add_import_directive(
531 ast::UseTreeKind::Nested(ref items) => {
532 // Ensure there is at most one `self` in the list
533 let self_spans = items
535 .filter_map(|&(ref use_tree, _)| {
536 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
537 if use_tree.ident().name == kw::SelfLower {
538 return Some(use_tree.span);
544 .collect::<Vec<_>>();
545 if self_spans.len() > 1 {
546 let mut e = self.r.into_struct_error(
548 ResolutionError::SelfImportCanOnlyAppearOnceInTheList,
551 for other_span in self_spans.iter().skip(1) {
552 e.span_label(*other_span, "another `self` import appears here");
558 for &(ref tree, id) in items {
559 self.build_reduced_graph_for_use_tree(
560 // This particular use tree
561 tree, id, &prefix, true, // The whole `use` item
562 item, vis, root_span,
566 // Empty groups `a::b::{}` are turned into synthetic `self` imports
567 // `a::b::c::{self as _}`, so that their prefixes are correctly
568 // resolved and checked for privacy/stability/etc.
569 if items.is_empty() && !empty_for_self(&prefix) {
570 let new_span = prefix[prefix.len() - 1].ident.span;
571 let tree = ast::UseTree {
572 prefix: ast::Path::from_ident(Ident::new(kw::SelfLower, new_span)),
573 kind: ast::UseTreeKind::Simple(
574 Some(Ident::new(kw::Underscore, new_span)),
580 self.build_reduced_graph_for_use_tree(
581 // This particular use tree
586 // The whole `use` item
588 ty::Visibility::Invisible,
596 /// Constructs the reduced graph for one item.
597 fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
598 let parent_scope = &self.parent_scope;
599 let parent = parent_scope.module;
600 let expansion = parent_scope.expansion;
601 let ident = item.ident;
603 let vis = self.resolve_visibility(&item.vis);
606 ItemKind::Use(ref use_tree) => {
607 self.build_reduced_graph_for_use_tree(
608 // This particular use tree
613 // The whole `use` item
620 ItemKind::ExternCrate(orig_name) => {
621 let module = if orig_name.is_none() && ident.name == kw::SelfLower {
624 .struct_span_err(item.span, "`extern crate self;` requires renaming")
628 "extern crate self as name;".into(),
629 Applicability::HasPlaceholders,
633 } else if orig_name == Some(kw::SelfLower) {
637 self.r.crate_loader.process_extern_crate(item, &self.r.definitions);
638 self.r.extern_crate_map.insert(item.id, crate_id);
639 self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
642 let used = self.process_legacy_macro_imports(item, module);
644 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
645 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
648 parent_scope: self.parent_scope,
649 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
650 subclass: ImportDirectiveSubclass::ExternCrate {
654 has_attributes: !item.attrs.is_empty(),
655 use_span_with_attributes: item.span_with_attributes(),
657 root_span: item.span,
659 module_path: Vec::new(),
661 used: Cell::new(used),
663 self.r.potentially_unused_imports.push(directive);
664 let imported_binding = self.r.import(binding, directive);
665 if ptr::eq(parent, self.r.graph_root) {
666 if let Some(entry) = self.r.extern_prelude.get(&ident.modern()) {
667 if expansion != ExpnId::root()
668 && orig_name.is_some()
669 && entry.extern_crate_item.is_none()
671 let msg = "macro-expanded `extern crate` items cannot \
672 shadow names passed with `--extern`";
673 self.r.session.span_err(item.span, msg);
677 self.r.extern_prelude.entry(ident.modern()).or_insert(ExternPreludeEntry {
678 extern_crate_item: None,
679 introduced_by_item: true,
681 entry.extern_crate_item = Some(imported_binding);
682 if orig_name.is_some() {
683 entry.introduced_by_item = true;
686 self.r.define(parent, ident, TypeNS, imported_binding);
689 ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
691 ItemKind::Mod(..) => {
692 let def_id = self.r.definitions.local_def_id(item.id);
693 let module_kind = ModuleKind::Def(DefKind::Mod, def_id, ident.name);
694 let module = self.r.arenas.alloc_module(ModuleData {
695 no_implicit_prelude: parent.no_implicit_prelude || {
696 attr::contains_name(&item.attrs, sym::no_implicit_prelude)
698 ..ModuleData::new(Some(parent), module_kind, def_id, expansion, item.span)
700 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
701 self.r.module_map.insert(def_id, module);
703 // Descend into the module.
704 self.parent_scope.module = module;
707 // These items live in the value namespace.
708 ItemKind::Static(..) => {
709 let res = Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id));
710 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
712 ItemKind::Const(..) => {
713 let res = Res::Def(DefKind::Const, self.r.definitions.local_def_id(item.id));
714 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
716 ItemKind::Fn(..) => {
717 let res = Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id));
718 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
720 // Functions introducing procedural macros reserve a slot
721 // in the macro namespace as well (see #52225).
722 self.define_macro(item);
725 // These items live in the type namespace.
726 ItemKind::TyAlias(ref ty, _) => {
727 let def_kind = match ty.kind.opaque_top_hack() {
728 None => DefKind::TyAlias,
729 Some(_) => DefKind::OpaqueTy,
731 let res = Res::Def(def_kind, self.r.definitions.local_def_id(item.id));
732 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
735 ItemKind::Enum(_, _) => {
736 let def_id = self.r.definitions.local_def_id(item.id);
737 self.r.variant_vis.insert(def_id, vis);
738 let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
739 let module = self.r.new_module(
742 parent.normal_ancestor_id,
746 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
747 self.parent_scope.module = module;
750 ItemKind::TraitAlias(..) => {
751 let res = Res::Def(DefKind::TraitAlias, self.r.definitions.local_def_id(item.id));
752 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
755 // These items live in both the type and value namespaces.
756 ItemKind::Struct(ref vdata, _) => {
757 // Define a name in the type namespace.
758 let def_id = self.r.definitions.local_def_id(item.id);
759 let res = Res::Def(DefKind::Struct, def_id);
760 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
762 // Record field names for error reporting.
763 self.insert_field_names_local(def_id, vdata);
765 // If this is a tuple or unit struct, define a name
766 // in the value namespace as well.
767 if let Some(ctor_node_id) = vdata.ctor_id() {
768 let mut ctor_vis = vis;
769 // If the structure is marked as non_exhaustive then lower the visibility
770 // to within the crate.
771 if vis == ty::Visibility::Public
772 && attr::contains_name(&item.attrs, sym::non_exhaustive)
774 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
776 for field in vdata.fields() {
777 // NOTE: The field may be an expansion placeholder, but expansion sets
778 // correct visibilities for unnamed field placeholders specifically, so the
779 // constructor visibility should still be determined correctly.
780 if let Ok(field_vis) = self.resolve_visibility_speculative(&field.vis, true)
782 if ctor_vis.is_at_least(field_vis, &*self.r) {
783 ctor_vis = field_vis;
787 let ctor_res = Res::Def(
788 DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(vdata)),
789 self.r.definitions.local_def_id(ctor_node_id),
791 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
792 self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis));
796 ItemKind::Union(ref vdata, _) => {
797 let def_id = self.r.definitions.local_def_id(item.id);
798 let res = Res::Def(DefKind::Union, def_id);
799 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
801 // Record field names for error reporting.
802 self.insert_field_names_local(def_id, vdata);
805 ItemKind::Trait(..) => {
806 let def_id = self.r.definitions.local_def_id(item.id);
808 // Add all the items within to a new module.
809 let module_kind = ModuleKind::Def(DefKind::Trait, def_id, ident.name);
810 let module = self.r.new_module(
813 parent.normal_ancestor_id,
817 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
818 self.parent_scope.module = module;
821 // These items do not add names to modules.
822 ItemKind::Impl(..) | ItemKind::ForeignMod(..) | ItemKind::GlobalAsm(..) => {}
824 ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
828 /// Constructs the reduced graph for one foreign item.
829 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
830 let (res, ns) = match item.kind {
831 ForeignItemKind::Fn(..) => {
832 (Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id)), ValueNS)
834 ForeignItemKind::Static(..) => {
835 (Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id)), ValueNS)
837 ForeignItemKind::Ty => {
838 (Res::Def(DefKind::ForeignTy, self.r.definitions.local_def_id(item.id)), TypeNS)
840 ForeignItemKind::Macro(_) => unreachable!(),
842 let parent = self.parent_scope.module;
843 let expansion = self.parent_scope.expansion;
844 let vis = self.resolve_visibility(&item.vis);
845 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
848 fn build_reduced_graph_for_block(&mut self, block: &Block) {
849 let parent = self.parent_scope.module;
850 let expansion = self.parent_scope.expansion;
851 if self.block_needs_anonymous_module(block) {
852 let module = self.r.new_module(
854 ModuleKind::Block(block.id),
855 parent.normal_ancestor_id,
859 self.r.block_map.insert(block.id, module);
860 self.parent_scope.module = module; // Descend into the block.
864 /// Builds the reduced graph for a single item in an external crate.
865 fn build_reduced_graph_for_external_crate_res(&mut self, child: Export<NodeId>) {
866 let parent = self.parent_scope.module;
867 let Export { ident, res, vis, span } = child;
868 let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
869 // Record primary definitions.
871 Res::Def(kind @ DefKind::Mod, def_id)
872 | Res::Def(kind @ DefKind::Enum, def_id)
873 | Res::Def(kind @ DefKind::Trait, def_id) => {
874 let module = self.r.new_module(
876 ModuleKind::Def(kind, def_id, ident.name),
881 self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
883 Res::Def(DefKind::Struct, _)
884 | Res::Def(DefKind::Union, _)
885 | Res::Def(DefKind::Variant, _)
886 | Res::Def(DefKind::TyAlias, _)
887 | Res::Def(DefKind::ForeignTy, _)
888 | Res::Def(DefKind::OpaqueTy, _)
889 | Res::Def(DefKind::TraitAlias, _)
890 | Res::Def(DefKind::AssocTy, _)
891 | Res::Def(DefKind::AssocOpaqueTy, _)
893 | Res::ToolMod => self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
894 Res::Def(DefKind::Fn, _)
895 | Res::Def(DefKind::Method, _)
896 | Res::Def(DefKind::Static, _)
897 | Res::Def(DefKind::Const, _)
898 | Res::Def(DefKind::AssocConst, _)
899 | Res::Def(DefKind::Ctor(..), _) => {
900 self.r.define(parent, ident, ValueNS, (res, vis, span, expansion))
902 Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
903 self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
905 Res::Def(DefKind::TyParam, _)
906 | Res::Def(DefKind::ConstParam, _)
910 | Res::Err => bug!("unexpected resolution: {:?}", res),
912 // Record some extra data for better diagnostics.
913 let cstore = self.r.cstore();
915 Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
916 let field_names = cstore.struct_field_names_untracked(def_id, self.r.session);
917 self.insert_field_names(def_id, field_names);
919 Res::Def(DefKind::Method, def_id) => {
920 if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
921 self.r.has_self.insert(def_id);
924 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
925 let parent = cstore.def_key(def_id).parent;
926 if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
927 self.r.struct_constructors.insert(struct_def_id, (res, vis));
934 fn legacy_import_macro(
937 binding: &'a NameBinding<'a>,
939 allow_shadowing: bool,
941 if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
942 let msg = format!("`{}` is already in scope", name);
944 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
945 self.r.session.struct_span_err(span, &msg).note(note).emit();
949 /// Returns `true` if we should consider the underlying `extern crate` to be used.
950 fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
951 let mut import_all = None;
952 let mut single_imports = Vec::new();
953 for attr in &item.attrs {
954 if attr.check_name(sym::macro_use) {
955 if self.parent_scope.module.parent.is_some() {
960 "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 {
970 "`macro_use` is not supported on `extern crate self`",
976 |span| struct_span_err!(self.r.session, span, E0466, "bad macro import").emit();
978 Some(meta) => match meta.kind {
979 MetaItemKind::Word => {
980 import_all = Some(meta.span);
983 MetaItemKind::List(nested_metas) => {
984 for nested_meta in nested_metas {
985 match nested_meta.ident() {
986 Some(ident) if nested_meta.is_word() => {
987 single_imports.push(ident)
989 _ => ill_formed(nested_meta.span()),
993 MetaItemKind::NameValue(..) => ill_formed(meta.span),
995 None => ill_formed(attr.span),
1000 let macro_use_directive = |this: &Self, span| {
1001 this.r.arenas.alloc_import_directive(ImportDirective {
1004 parent_scope: this.parent_scope,
1005 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
1006 subclass: ImportDirectiveSubclass::MacroUse,
1007 use_span_with_attributes: item.span_with_attributes(),
1008 has_attributes: !item.attrs.is_empty(),
1009 use_span: item.span,
1012 module_path: Vec::new(),
1013 vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
1014 used: Cell::new(false),
1018 let allow_shadowing = self.parent_scope.expansion == ExpnId::root();
1019 if let Some(span) = import_all {
1020 let directive = macro_use_directive(self, span);
1021 self.r.potentially_unused_imports.push(directive);
1022 module.for_each_child(self, |this, ident, ns, binding| {
1024 let imported_binding = this.r.import(binding, directive);
1025 this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
1029 for ident in single_imports.iter().cloned() {
1030 let result = self.r.resolve_ident_in_module(
1031 ModuleOrUniformRoot::Module(module),
1038 if let Ok(binding) = result {
1039 let directive = macro_use_directive(self, ident.span);
1040 self.r.potentially_unused_imports.push(directive);
1041 let imported_binding = self.r.import(binding, directive);
1042 self.legacy_import_macro(
1049 struct_span_err!(self.r.session, ident.span, E0469, "imported macro not found")
1054 import_all.is_some() || !single_imports.is_empty()
1057 /// Returns `true` if this attribute list contains `macro_use`.
1058 fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool {
1060 if attr.check_name(sym::macro_escape) {
1061 let msg = "macro_escape is a deprecated synonym for macro_use";
1062 let mut err = self.r.session.struct_span_warn(attr.span, msg);
1063 if let ast::AttrStyle::Inner = attr.style {
1064 err.help("consider an outer attribute, `#[macro_use]` mod ...").emit();
1068 } else if !attr.check_name(sym::macro_use) {
1072 if !attr.is_word() {
1073 self.r.session.span_err(attr.span, "arguments to macro_use are not allowed here");
1081 fn visit_invoc(&mut self, id: NodeId) -> LegacyScope<'a> {
1082 let invoc_id = id.placeholder_to_expn_id();
1084 self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id);
1086 let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope);
1087 assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation");
1089 LegacyScope::Invocation(invoc_id)
1092 fn proc_macro_stub(item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
1093 if attr::contains_name(&item.attrs, sym::proc_macro) {
1094 return Some((MacroKind::Bang, item.ident, item.span));
1095 } else if attr::contains_name(&item.attrs, sym::proc_macro_attribute) {
1096 return Some((MacroKind::Attr, item.ident, item.span));
1097 } else if let Some(attr) = attr::find_by_name(&item.attrs, sym::proc_macro_derive) {
1098 if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
1099 if let Some(ident) = nested_meta.ident() {
1100 return Some((MacroKind::Derive, ident, ident.span));
1107 // Mark the given macro as unused unless its name starts with `_`.
1108 // Macro uses will remove items from this set, and the remaining
1109 // items will be reported as `unused_macros`.
1110 fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) {
1111 if !ident.as_str().starts_with("_") {
1112 self.r.unused_macros.insert(node_id, span);
1116 fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> {
1117 let parent_scope = self.parent_scope;
1118 let expansion = parent_scope.expansion;
1119 let (ext, ident, span, is_legacy) = match &item.kind {
1120 ItemKind::MacroDef(def) => {
1121 let ext = Lrc::new(self.r.compile_macro(item, self.r.session.edition()));
1122 (ext, item.ident, item.span, def.legacy)
1124 ItemKind::Fn(..) => match Self::proc_macro_stub(item) {
1125 Some((macro_kind, ident, span)) => {
1126 self.r.proc_macro_stubs.insert(item.id);
1127 (self.r.dummy_ext(macro_kind), ident, span, false)
1129 None => return parent_scope.legacy,
1131 _ => unreachable!(),
1134 let def_id = self.r.definitions.local_def_id(item.id);
1135 let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id);
1136 self.r.macro_map.insert(def_id, ext);
1137 self.r.local_macro_def_scopes.insert(item.id, parent_scope.module);
1140 let ident = ident.modern();
1141 self.r.macro_names.insert(ident);
1142 let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
1143 let vis = if is_macro_export {
1144 ty::Visibility::Public
1146 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
1148 let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas);
1149 self.r.set_binding_parent_module(binding, parent_scope.module);
1150 self.r.all_macros.insert(ident.name, res);
1151 if is_macro_export {
1152 let module = self.r.graph_root;
1153 self.r.define(module, ident, MacroNS, (res, vis, span, expansion, IsMacroExport));
1155 self.r.check_reserved_macro_name(ident, res);
1156 self.insert_unused_macro(ident, item.id, span);
1158 LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding {
1159 parent_legacy_scope: parent_scope.legacy,
1164 let module = parent_scope.module;
1165 let vis = self.resolve_visibility(&item.vis);
1166 if vis != ty::Visibility::Public {
1167 self.insert_unused_macro(ident, item.id, span);
1169 self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
1170 self.parent_scope.legacy
1175 macro_rules! method {
1176 ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => {
1177 fn $visit(&mut self, node: &'b $ty) {
1178 if let $invoc(..) = node.kind {
1179 self.visit_invoc(node.id);
1181 visit::$walk(self, node);
1187 impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
1188 method!(visit_expr: ast::Expr, ast::ExprKind::Mac, walk_expr);
1189 method!(visit_pat: ast::Pat, ast::PatKind::Mac, walk_pat);
1190 method!(visit_ty: ast::Ty, ast::TyKind::Mac, walk_ty);
1192 fn visit_item(&mut self, item: &'b Item) {
1193 let macro_use = match item.kind {
1194 ItemKind::MacroDef(..) => {
1195 self.parent_scope.legacy = self.define_macro(item);
1198 ItemKind::Mac(..) => {
1199 self.parent_scope.legacy = self.visit_invoc(item.id);
1202 ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
1205 let orig_current_module = self.parent_scope.module;
1206 let orig_current_legacy_scope = self.parent_scope.legacy;
1207 self.build_reduced_graph_for_item(item);
1208 visit::walk_item(self, item);
1209 self.parent_scope.module = orig_current_module;
1211 self.parent_scope.legacy = orig_current_legacy_scope;
1215 fn visit_stmt(&mut self, stmt: &'b ast::Stmt) {
1216 if let ast::StmtKind::Mac(..) = stmt.kind {
1217 self.parent_scope.legacy = self.visit_invoc(stmt.id);
1219 visit::walk_stmt(self, stmt);
1223 fn visit_foreign_item(&mut self, foreign_item: &'b ForeignItem) {
1224 if let ForeignItemKind::Macro(_) = foreign_item.kind {
1225 self.visit_invoc(foreign_item.id);
1229 self.build_reduced_graph_for_foreign_item(foreign_item);
1230 visit::walk_foreign_item(self, foreign_item);
1233 fn visit_block(&mut self, block: &'b Block) {
1234 let orig_current_module = self.parent_scope.module;
1235 let orig_current_legacy_scope = self.parent_scope.legacy;
1236 self.build_reduced_graph_for_block(block);
1237 visit::walk_block(self, block);
1238 self.parent_scope.module = orig_current_module;
1239 self.parent_scope.legacy = orig_current_legacy_scope;
1242 fn visit_trait_item(&mut self, item: &'b AssocItem) {
1243 let parent = self.parent_scope.module;
1245 if let AssocItemKind::Macro(_) = item.kind {
1246 self.visit_invoc(item.id);
1250 // Add the item to the trait info.
1251 let item_def_id = self.r.definitions.local_def_id(item.id);
1252 let (res, ns) = match item.kind {
1253 AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
1254 AssocItemKind::Fn(ref sig, _) => {
1255 if sig.decl.has_self() {
1256 self.r.has_self.insert(item_def_id);
1258 (Res::Def(DefKind::Method, item_def_id), ValueNS)
1260 AssocItemKind::TyAlias(..) => (Res::Def(DefKind::AssocTy, item_def_id), TypeNS),
1261 AssocItemKind::Macro(_) => bug!(), // handled above
1264 let vis = ty::Visibility::Public;
1265 let expansion = self.parent_scope.expansion;
1266 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
1268 visit::walk_trait_item(self, item);
1271 fn visit_impl_item(&mut self, item: &'b ast::AssocItem) {
1272 if let ast::AssocItemKind::Macro(..) = item.kind {
1273 self.visit_invoc(item.id);
1275 self.resolve_visibility(&item.vis);
1276 visit::walk_impl_item(self, item);
1280 fn visit_token(&mut self, t: Token) {
1281 if let token::Interpolated(nt) = t.kind {
1282 if let token::NtExpr(ref expr) = *nt {
1283 if let ast::ExprKind::Mac(..) = expr.kind {
1284 self.visit_invoc(expr.id);
1290 fn visit_attribute(&mut self, attr: &'b ast::Attribute) {
1291 if !attr.is_doc_comment() && attr::is_builtin_attr(attr) {
1294 .push((attr.get_normal_item().path.segments[0].ident, self.parent_scope));
1296 visit::walk_attribute(self, attr);
1299 fn visit_arm(&mut self, arm: &'b ast::Arm) {
1300 if arm.is_placeholder {
1301 self.visit_invoc(arm.id);
1303 visit::walk_arm(self, arm);
1307 fn visit_field(&mut self, f: &'b ast::Field) {
1308 if f.is_placeholder {
1309 self.visit_invoc(f.id);
1311 visit::walk_field(self, f);
1315 fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
1316 if fp.is_placeholder {
1317 self.visit_invoc(fp.id);
1319 visit::walk_field_pattern(self, fp);
1323 fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
1324 if param.is_placeholder {
1325 self.visit_invoc(param.id);
1327 visit::walk_generic_param(self, param);
1331 fn visit_param(&mut self, p: &'b ast::Param) {
1332 if p.is_placeholder {
1333 self.visit_invoc(p.id);
1335 visit::walk_param(self, p);
1339 fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
1340 if sf.is_placeholder {
1341 self.visit_invoc(sf.id);
1343 self.resolve_visibility(&sf.vis);
1344 visit::walk_struct_field(self, sf);
1348 // Constructs the reduced graph for one variant. Variants exist in the
1349 // type and value namespaces.
1350 fn visit_variant(&mut self, variant: &'b ast::Variant) {
1351 if variant.is_placeholder {
1352 self.visit_invoc(variant.id);
1356 let parent = self.parent_scope.module;
1357 let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
1358 let expn_id = self.parent_scope.expansion;
1359 let ident = variant.ident;
1361 // Define a name in the type namespace.
1362 let def_id = self.r.definitions.local_def_id(variant.id);
1363 let res = Res::Def(DefKind::Variant, def_id);
1364 self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
1366 // If the variant is marked as non_exhaustive then lower the visibility to within the
1368 let mut ctor_vis = vis;
1369 let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
1370 if has_non_exhaustive && vis == ty::Visibility::Public {
1371 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
1374 // Define a constructor name in the value namespace.
1375 // Braced variants, unlike structs, generate unusable names in
1376 // value namespace, they are reserved for possible future use.
1377 // It's ok to use the variant's id as a ctor id since an
1378 // error will be reported on any use of such resolution anyway.
1379 let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
1380 let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
1381 let ctor_kind = CtorKind::from_ast(&variant.data);
1382 let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1383 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
1385 visit::walk_variant(self, variant);