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_attr as attr;
24 use rustc_data_structures::sync::Lrc;
25 use rustc_errors::{struct_span_err, Applicability};
26 use rustc_expand::base::SyntaxExtension;
27 use rustc_expand::expand::AstFragment;
28 use rustc_hir::def::{self, *};
29 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
30 use rustc_metadata::creader::LoadedMacro;
31 use rustc_span::hygiene::{ExpnId, MacroKind};
32 use rustc_span::source_map::{respan, Spanned};
33 use rustc_span::symbol::{kw, sym};
34 use rustc_span::{Span, DUMMY_SP};
35 use syntax::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
36 use syntax::ast::{AssocItem, AssocItemKind, MetaItemKind, StmtKind};
37 use syntax::ast::{Ident, Name};
38 use syntax::token::{self, Token};
39 use syntax::visit::{self, AssocCtxt, Visitor};
45 type Res = def::Res<NodeId>;
47 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, ExpnId) {
48 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
49 arenas.alloc_name_binding(NameBinding {
50 kind: NameBindingKind::Module(self.0),
59 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId) {
60 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
61 arenas.alloc_name_binding(NameBinding {
62 kind: NameBindingKind::Res(self.0, false),
73 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId, IsMacroExport) {
74 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
75 arenas.alloc_name_binding(NameBinding {
76 kind: NameBindingKind::Res(self.0, true),
85 impl<'a> Resolver<'a> {
86 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
87 /// otherwise, reports an error.
88 crate fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T)
92 let binding = def.to_name_binding(self.arenas);
93 let key = self.new_key(ident, ns);
94 if let Err(old_binding) = self.try_define(parent, key, binding) {
95 self.report_conflict(parent, ident, ns, old_binding, &binding);
99 crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
100 if def_id.krate == LOCAL_CRATE {
101 return self.module_map[&def_id];
104 if let Some(&module) = self.extern_module_map.get(&def_id) {
108 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
109 (self.cstore().crate_name_untracked(def_id.krate), None)
111 let def_key = self.cstore().def_key(def_id);
113 def_key.disambiguated_data.data.get_opt_name().unwrap(),
114 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })),
118 let kind = ModuleKind::Def(DefKind::Mod, def_id, name);
119 let module = self.arenas.alloc_module(ModuleData::new(
126 self.extern_module_map.insert(def_id, module);
130 crate fn macro_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> {
131 let def_id = match self.macro_defs.get(&expn_id) {
132 Some(def_id) => *def_id,
133 None => return self.ast_transform_scopes.get(&expn_id).unwrap_or(&self.graph_root),
135 if let Some(id) = self.definitions.as_local_node_id(def_id) {
136 self.local_macro_def_scopes[&id]
138 let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
139 self.get_module(module_def_id)
143 crate fn get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
145 Res::Def(DefKind::Macro(..), def_id) => self.get_macro_by_def_id(def_id),
146 Res::NonMacroAttr(attr_kind) => Some(self.non_macro_attr(attr_kind.is_used())),
151 crate fn get_macro_by_def_id(&mut self, def_id: DefId) -> Option<Lrc<SyntaxExtension>> {
152 if let Some(ext) = self.macro_map.get(&def_id) {
153 return Some(ext.clone());
156 let ext = Lrc::new(match self.cstore().load_macro_untracked(def_id, &self.session) {
157 LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition),
158 LoadedMacro::ProcMacro(ext) => ext,
161 self.macro_map.insert(def_id, ext.clone());
165 crate fn build_reduced_graph(
167 fragment: &AstFragment,
168 parent_scope: ParentScope<'a>,
169 ) -> LegacyScope<'a> {
170 collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
171 let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
172 fragment.visit_with(&mut visitor);
173 visitor.parent_scope.legacy
176 crate fn build_reduced_graph_external(&mut self, module: Module<'a>) {
177 let def_id = module.def_id().expect("unpopulated module without a def-id");
178 for child in self.cstore().item_children_untracked(def_id, self.session) {
179 let child = child.map_id(|_| panic!("unexpected id"));
180 BuildReducedGraphVisitor { r: self, parent_scope: ParentScope::module(module) }
181 .build_reduced_graph_for_external_crate_res(child);
186 struct BuildReducedGraphVisitor<'a, 'b> {
187 r: &'b mut Resolver<'a>,
188 parent_scope: ParentScope<'a>,
191 impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> {
192 fn as_mut(&mut self) -> &mut Resolver<'a> {
197 impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
198 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
199 self.resolve_visibility_speculative(vis, false).unwrap_or_else(|err| {
200 self.r.report_vis_error(err);
201 ty::Visibility::Public
205 fn resolve_visibility_speculative<'ast>(
207 vis: &'ast ast::Visibility,
209 ) -> Result<ty::Visibility, VisResolutionError<'ast>> {
210 let parent_scope = &self.parent_scope;
212 ast::VisibilityKind::Public => Ok(ty::Visibility::Public),
213 ast::VisibilityKind::Crate(..) => {
214 Ok(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)))
216 ast::VisibilityKind::Inherited => {
217 Ok(ty::Visibility::Restricted(parent_scope.module.normal_ancestor_id))
219 ast::VisibilityKind::Restricted { ref path, id, .. } => {
220 // For visibilities we are not ready to provide correct implementation of "uniform
221 // paths" right now, so on 2018 edition we only allow module-relative paths for now.
222 // On 2015 edition visibilities are resolved as crate-relative by default,
223 // so we are prepending a root segment if necessary.
224 let ident = path.segments.get(0).expect("empty path in visibility").ident;
225 let crate_root = if ident.is_path_segment_keyword() {
227 } else if ident.span.rust_2015() {
228 Some(Segment::from_ident(Ident::new(
230 path.span.shrink_to_lo().with_ctxt(ident.span.ctxt()),
233 return Err(VisResolutionError::Relative2018(ident.span, path));
236 let segments = crate_root
238 .chain(path.segments.iter().map(|seg| seg.into()))
239 .collect::<Vec<_>>();
240 let expected_found_error = |res| {
241 Err(VisResolutionError::ExpectedFound(
243 Segment::names_to_string(&segments),
247 match self.r.resolve_path(
253 CrateLint::SimplePath(id),
255 PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
256 let res = module.res().expect("visibility resolved to unnamed block");
258 self.r.record_partial_res(id, PartialRes::new(res));
260 if module.is_normal() {
262 Ok(ty::Visibility::Public)
264 let vis = ty::Visibility::Restricted(res.def_id());
265 if self.r.is_accessible_from(vis, parent_scope.module) {
268 Err(VisResolutionError::AncestorOnly(path.span))
272 expected_found_error(res)
275 PathResult::Module(..) => Err(VisResolutionError::ModuleOnly(path.span)),
276 PathResult::NonModule(partial_res) => {
277 expected_found_error(partial_res.base_res())
279 PathResult::Failed { span, label, suggestion, .. } => {
280 Err(VisResolutionError::FailedToResolve(span, label, suggestion))
282 PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
288 fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
289 let field_names = vdata
292 .map(|field| respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name)))
294 self.insert_field_names(def_id, field_names);
297 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Name>>) {
298 if !field_names.is_empty() {
299 self.r.field_names.insert(def_id, field_names);
303 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
304 // If any statements are items, we need to create an anonymous module
305 block.stmts.iter().any(|statement| match statement.kind {
306 StmtKind::Item(_) | StmtKind::Mac(_) => true,
311 // Add an import directive to the current module.
312 fn add_import_directive(
314 module_path: Vec<Segment>,
315 subclass: ImportDirectiveSubclass<'a>,
323 let current_module = self.parent_scope.module;
324 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
325 parent_scope: self.parent_scope,
327 imported_module: Cell::new(None),
332 use_span_with_attributes: item.span_with_attributes(),
333 has_attributes: !item.attrs.is_empty(),
337 used: Cell::new(false),
340 debug!("add_import_directive({:?})", directive);
342 self.r.indeterminate_imports.push(directive);
343 match directive.subclass {
344 // Don't add unresolved underscore imports to modules
345 SingleImport { target: Ident { name: kw::Underscore, .. }, .. } => {}
346 SingleImport { target, type_ns_only, .. } => {
347 self.r.per_ns(|this, ns| {
348 if !type_ns_only || ns == TypeNS {
349 let key = this.new_key(target, ns);
350 let mut resolution = this.resolution(current_module, key).borrow_mut();
351 resolution.add_single_import(directive);
355 // We don't add prelude imports to the globs since they only affect lexical scopes,
356 // which are not relevant to import resolution.
357 GlobImport { is_prelude: true, .. } => {}
358 GlobImport { .. } => current_module.globs.borrow_mut().push(directive),
363 fn build_reduced_graph_for_use_tree(
365 // This particular use tree
366 use_tree: &ast::UseTree,
368 parent_prefix: &[Segment],
370 // The whole `use` item
376 "build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})",
377 parent_prefix, use_tree, nested
380 let mut prefix_iter = parent_prefix
383 .chain(use_tree.prefix.segments.iter().map(|seg| seg.into()))
386 // On 2015 edition imports are resolved as crate-relative by default,
387 // so prefixes are prepended with crate root segment if necessary.
388 // The root is prepended lazily, when the first non-empty prefix or terminating glob
389 // appears, so imports in braced groups can have roots prepended independently.
390 let is_glob = if let ast::UseTreeKind::Glob = use_tree.kind { true } else { false };
391 let crate_root = match prefix_iter.peek() {
392 Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => {
393 Some(seg.ident.span.ctxt())
395 None if is_glob && use_tree.span.rust_2015() => Some(use_tree.span.ctxt()),
399 Segment::from_ident(Ident::new(
401 use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt),
405 let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>();
406 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
408 let empty_for_self = |prefix: &[Segment]| {
409 prefix.is_empty() || prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot
411 match use_tree.kind {
412 ast::UseTreeKind::Simple(rename, ..) => {
413 let mut ident = use_tree.ident();
414 let mut module_path = prefix;
415 let mut source = module_path.pop().unwrap();
416 let mut type_ns_only = false;
419 // Correctly handle `self`
420 if source.ident.name == kw::SelfLower {
423 if empty_for_self(&module_path) {
426 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix,
431 // Replace `use foo::self;` with `use foo;`
432 source = module_path.pop().unwrap();
433 if rename.is_none() {
434 ident = source.ident;
439 if source.ident.name == kw::SelfLower {
442 ResolutionError::SelfImportsOnlyAllowedWithin,
446 // Disallow `use $crate;`
447 if source.ident.name == kw::DollarCrate && module_path.is_empty() {
448 let crate_root = self.r.resolve_crate_root(source.ident);
449 let crate_name = match crate_root.kind {
450 ModuleKind::Def(.., name) => name,
451 ModuleKind::Block(..) => unreachable!(),
453 // HACK(eddyb) unclear how good this is, but keeping `$crate`
454 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
455 // while the current crate doesn't have a valid `crate_name`.
456 if crate_name != kw::Invalid {
457 // `crate_name` should not be interpreted as relative.
458 module_path.push(Segment {
459 ident: Ident { name: kw::PathRoot, span: source.ident.span },
460 id: Some(self.r.next_node_id()),
462 source.ident.name = crate_name;
464 if rename.is_none() {
465 ident.name = crate_name;
470 .struct_span_err(item.span, "`$crate` may not be imported")
475 if ident.name == kw::Crate {
476 self.r.session.span_err(
478 "crate root imports need to be explicitly named: \
479 `use crate as name;`",
483 let subclass = SingleImport {
484 source: source.ident,
486 source_bindings: PerNS {
487 type_ns: Cell::new(Err(Determinacy::Undetermined)),
488 value_ns: Cell::new(Err(Determinacy::Undetermined)),
489 macro_ns: Cell::new(Err(Determinacy::Undetermined)),
491 target_bindings: PerNS {
492 type_ns: Cell::new(None),
493 value_ns: Cell::new(None),
494 macro_ns: Cell::new(None),
499 self.add_import_directive(
510 ast::UseTreeKind::Glob => {
511 let subclass = GlobImport {
512 is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
513 max_vis: Cell::new(ty::Visibility::Invisible),
515 self.add_import_directive(
526 ast::UseTreeKind::Nested(ref items) => {
527 // Ensure there is at most one `self` in the list
528 let self_spans = items
530 .filter_map(|&(ref use_tree, _)| {
531 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
532 if use_tree.ident().name == kw::SelfLower {
533 return Some(use_tree.span);
539 .collect::<Vec<_>>();
540 if self_spans.len() > 1 {
541 let mut e = self.r.into_struct_error(
543 ResolutionError::SelfImportCanOnlyAppearOnceInTheList,
546 for other_span in self_spans.iter().skip(1) {
547 e.span_label(*other_span, "another `self` import appears here");
553 for &(ref tree, id) in items {
554 self.build_reduced_graph_for_use_tree(
555 // This particular use tree
556 tree, id, &prefix, true, // The whole `use` item
557 item, vis, root_span,
561 // Empty groups `a::b::{}` are turned into synthetic `self` imports
562 // `a::b::c::{self as _}`, so that their prefixes are correctly
563 // resolved and checked for privacy/stability/etc.
564 if items.is_empty() && !empty_for_self(&prefix) {
565 let new_span = prefix[prefix.len() - 1].ident.span;
566 let tree = ast::UseTree {
567 prefix: ast::Path::from_ident(Ident::new(kw::SelfLower, new_span)),
568 kind: ast::UseTreeKind::Simple(
569 Some(Ident::new(kw::Underscore, new_span)),
575 self.build_reduced_graph_for_use_tree(
576 // This particular use tree
581 // The whole `use` item
583 ty::Visibility::Invisible,
591 /// Constructs the reduced graph for one item.
592 fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
593 let parent_scope = &self.parent_scope;
594 let parent = parent_scope.module;
595 let expansion = parent_scope.expansion;
596 let ident = item.ident;
598 let vis = self.resolve_visibility(&item.vis);
601 ItemKind::Use(ref use_tree) => {
602 self.build_reduced_graph_for_use_tree(
603 // This particular use tree
608 // The whole `use` item
615 ItemKind::ExternCrate(orig_name) => {
616 let module = if orig_name.is_none() && ident.name == kw::SelfLower {
619 .struct_span_err(item.span, "`extern crate self;` requires renaming")
623 "extern crate self as name;".into(),
624 Applicability::HasPlaceholders,
628 } else if orig_name == Some(kw::SelfLower) {
632 self.r.crate_loader.process_extern_crate(item, &self.r.definitions);
633 self.r.extern_crate_map.insert(item.id, crate_id);
634 self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
637 let used = self.process_legacy_macro_imports(item, module);
639 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
640 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
643 parent_scope: self.parent_scope,
644 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
645 subclass: ImportDirectiveSubclass::ExternCrate {
649 has_attributes: !item.attrs.is_empty(),
650 use_span_with_attributes: item.span_with_attributes(),
652 root_span: item.span,
654 module_path: Vec::new(),
656 used: Cell::new(used),
658 self.r.potentially_unused_imports.push(directive);
659 let imported_binding = self.r.import(binding, directive);
660 if ptr::eq(parent, self.r.graph_root) {
661 if let Some(entry) = self.r.extern_prelude.get(&ident.modern()) {
662 if expansion != ExpnId::root()
663 && orig_name.is_some()
664 && entry.extern_crate_item.is_none()
666 let msg = "macro-expanded `extern crate` items cannot \
667 shadow names passed with `--extern`";
668 self.r.session.span_err(item.span, msg);
672 self.r.extern_prelude.entry(ident.modern()).or_insert(ExternPreludeEntry {
673 extern_crate_item: None,
674 introduced_by_item: true,
676 entry.extern_crate_item = Some(imported_binding);
677 if orig_name.is_some() {
678 entry.introduced_by_item = true;
681 self.r.define(parent, ident, TypeNS, imported_binding);
684 ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
686 ItemKind::Mod(..) => {
687 let def_id = self.r.definitions.local_def_id(item.id);
688 let module_kind = ModuleKind::Def(DefKind::Mod, def_id, ident.name);
689 let module = self.r.arenas.alloc_module(ModuleData {
690 no_implicit_prelude: parent.no_implicit_prelude || {
691 attr::contains_name(&item.attrs, sym::no_implicit_prelude)
693 ..ModuleData::new(Some(parent), module_kind, def_id, expansion, item.span)
695 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
696 self.r.module_map.insert(def_id, module);
698 // Descend into the module.
699 self.parent_scope.module = module;
702 // These items live in the value namespace.
703 ItemKind::Static(..) => {
704 let res = Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id));
705 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
707 ItemKind::Const(..) => {
708 let res = Res::Def(DefKind::Const, self.r.definitions.local_def_id(item.id));
709 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
711 ItemKind::Fn(..) => {
712 let res = Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id));
713 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
715 // Functions introducing procedural macros reserve a slot
716 // in the macro namespace as well (see #52225).
717 self.define_macro(item);
720 // These items live in the type namespace.
721 ItemKind::TyAlias(_, _, _, ref ty) => {
722 let def_kind = match ty.as_deref().and_then(|ty| ty.kind.opaque_top_hack()) {
723 None => DefKind::TyAlias,
724 Some(_) => DefKind::OpaqueTy,
726 let res = Res::Def(def_kind, self.r.definitions.local_def_id(item.id));
727 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
730 ItemKind::Enum(_, _) => {
731 let def_id = self.r.definitions.local_def_id(item.id);
732 self.r.variant_vis.insert(def_id, vis);
733 let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
734 let module = self.r.new_module(
737 parent.normal_ancestor_id,
741 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
742 self.parent_scope.module = module;
745 ItemKind::TraitAlias(..) => {
746 let res = Res::Def(DefKind::TraitAlias, self.r.definitions.local_def_id(item.id));
747 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
750 // These items live in both the type and value namespaces.
751 ItemKind::Struct(ref vdata, _) => {
752 // Define a name in the type namespace.
753 let def_id = self.r.definitions.local_def_id(item.id);
754 let res = Res::Def(DefKind::Struct, def_id);
755 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
757 // Record field names for error reporting.
758 self.insert_field_names_local(def_id, vdata);
760 // If this is a tuple or unit struct, define a name
761 // in the value namespace as well.
762 if let Some(ctor_node_id) = vdata.ctor_id() {
763 let mut ctor_vis = vis;
764 // If the structure is marked as non_exhaustive then lower the visibility
765 // to within the crate.
766 if vis == ty::Visibility::Public
767 && attr::contains_name(&item.attrs, sym::non_exhaustive)
769 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
771 for field in vdata.fields() {
772 // NOTE: The field may be an expansion placeholder, but expansion sets
773 // correct visibilities for unnamed field placeholders specifically, so the
774 // constructor visibility should still be determined correctly.
775 if let Ok(field_vis) = self.resolve_visibility_speculative(&field.vis, true)
777 if ctor_vis.is_at_least(field_vis, &*self.r) {
778 ctor_vis = field_vis;
782 let ctor_res = Res::Def(
783 DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(vdata)),
784 self.r.definitions.local_def_id(ctor_node_id),
786 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
787 self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis));
791 ItemKind::Union(ref vdata, _) => {
792 let def_id = self.r.definitions.local_def_id(item.id);
793 let res = Res::Def(DefKind::Union, def_id);
794 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
796 // Record field names for error reporting.
797 self.insert_field_names_local(def_id, vdata);
800 ItemKind::Trait(..) => {
801 let def_id = self.r.definitions.local_def_id(item.id);
803 // Add all the items within to a new module.
804 let module_kind = ModuleKind::Def(DefKind::Trait, def_id, ident.name);
805 let module = self.r.new_module(
808 parent.normal_ancestor_id,
812 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
813 self.parent_scope.module = module;
816 // These items do not add names to modules.
817 ItemKind::Impl { .. } | ItemKind::ForeignMod(..) | ItemKind::GlobalAsm(..) => {}
819 ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
823 /// Constructs the reduced graph for one foreign item.
824 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
825 let (res, ns) = match item.kind {
826 ForeignItemKind::Fn(..) => {
827 (Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id)), ValueNS)
829 ForeignItemKind::Static(..) | ForeignItemKind::Const(..) => {
830 (Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id)), ValueNS)
832 ForeignItemKind::TyAlias(..) => {
833 (Res::Def(DefKind::ForeignTy, self.r.definitions.local_def_id(item.id)), TypeNS)
835 ForeignItemKind::Macro(_) => unreachable!(),
837 let parent = self.parent_scope.module;
838 let expansion = self.parent_scope.expansion;
839 let vis = self.resolve_visibility(&item.vis);
840 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
843 fn build_reduced_graph_for_block(&mut self, block: &Block) {
844 let parent = self.parent_scope.module;
845 let expansion = self.parent_scope.expansion;
846 if self.block_needs_anonymous_module(block) {
847 let module = self.r.new_module(
849 ModuleKind::Block(block.id),
850 parent.normal_ancestor_id,
854 self.r.block_map.insert(block.id, module);
855 self.parent_scope.module = module; // Descend into the block.
859 /// Builds the reduced graph for a single item in an external crate.
860 fn build_reduced_graph_for_external_crate_res(&mut self, child: Export<NodeId>) {
861 let parent = self.parent_scope.module;
862 let Export { ident, res, vis, span } = child;
863 let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
864 // Record primary definitions.
866 Res::Def(kind @ DefKind::Mod, def_id)
867 | Res::Def(kind @ DefKind::Enum, def_id)
868 | Res::Def(kind @ DefKind::Trait, def_id) => {
869 let module = self.r.new_module(
871 ModuleKind::Def(kind, def_id, ident.name),
876 self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
878 Res::Def(DefKind::Struct, _)
879 | Res::Def(DefKind::Union, _)
880 | Res::Def(DefKind::Variant, _)
881 | Res::Def(DefKind::TyAlias, _)
882 | Res::Def(DefKind::ForeignTy, _)
883 | Res::Def(DefKind::OpaqueTy, _)
884 | Res::Def(DefKind::TraitAlias, _)
885 | Res::Def(DefKind::AssocTy, _)
886 | Res::Def(DefKind::AssocOpaqueTy, _)
888 | Res::ToolMod => self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
889 Res::Def(DefKind::Fn, _)
890 | Res::Def(DefKind::Method, _)
891 | Res::Def(DefKind::Static, _)
892 | Res::Def(DefKind::Const, _)
893 | Res::Def(DefKind::AssocConst, _)
894 | Res::Def(DefKind::Ctor(..), _) => {
895 self.r.define(parent, ident, ValueNS, (res, vis, span, expansion))
897 Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
898 self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
900 Res::Def(DefKind::TyParam, _)
901 | Res::Def(DefKind::ConstParam, _)
905 | Res::Err => bug!("unexpected resolution: {:?}", res),
907 // Record some extra data for better diagnostics.
908 let cstore = self.r.cstore();
910 Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
911 let field_names = cstore.struct_field_names_untracked(def_id, self.r.session);
912 self.insert_field_names(def_id, field_names);
914 Res::Def(DefKind::Method, def_id) => {
915 if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
916 self.r.has_self.insert(def_id);
919 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
920 let parent = cstore.def_key(def_id).parent;
921 if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
922 self.r.struct_constructors.insert(struct_def_id, (res, vis));
929 fn legacy_import_macro(
932 binding: &'a NameBinding<'a>,
934 allow_shadowing: bool,
936 if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
937 let msg = format!("`{}` is already in scope", name);
939 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
940 self.r.session.struct_span_err(span, &msg).note(note).emit();
944 /// Returns `true` if we should consider the underlying `extern crate` to be used.
945 fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
946 let mut import_all = None;
947 let mut single_imports = Vec::new();
948 for attr in &item.attrs {
949 if attr.check_name(sym::macro_use) {
950 if self.parent_scope.module.parent.is_some() {
955 "an `extern crate` loading macros must be at the crate root"
959 if let ItemKind::ExternCrate(Some(orig_name)) = item.kind {
960 if orig_name == kw::SelfLower {
965 "`#[macro_use]` is not supported on `extern crate self`",
971 |span| struct_span_err!(self.r.session, span, E0466, "bad macro import").emit();
973 Some(meta) => match meta.kind {
974 MetaItemKind::Word => {
975 import_all = Some(meta.span);
978 MetaItemKind::List(nested_metas) => {
979 for nested_meta in nested_metas {
980 match nested_meta.ident() {
981 Some(ident) if nested_meta.is_word() => {
982 single_imports.push(ident)
984 _ => ill_formed(nested_meta.span()),
988 MetaItemKind::NameValue(..) => ill_formed(meta.span),
990 None => ill_formed(attr.span),
995 let macro_use_directive = |this: &Self, span| {
996 this.r.arenas.alloc_import_directive(ImportDirective {
999 parent_scope: this.parent_scope,
1000 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
1001 subclass: ImportDirectiveSubclass::MacroUse,
1002 use_span_with_attributes: item.span_with_attributes(),
1003 has_attributes: !item.attrs.is_empty(),
1004 use_span: item.span,
1007 module_path: Vec::new(),
1008 vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
1009 used: Cell::new(false),
1013 let allow_shadowing = self.parent_scope.expansion == ExpnId::root();
1014 if let Some(span) = import_all {
1015 let directive = macro_use_directive(self, span);
1016 self.r.potentially_unused_imports.push(directive);
1017 module.for_each_child(self, |this, ident, ns, binding| {
1019 let imported_binding = this.r.import(binding, directive);
1020 this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
1024 for ident in single_imports.iter().cloned() {
1025 let result = self.r.resolve_ident_in_module(
1026 ModuleOrUniformRoot::Module(module),
1033 if let Ok(binding) = result {
1034 let directive = macro_use_directive(self, ident.span);
1035 self.r.potentially_unused_imports.push(directive);
1036 let imported_binding = self.r.import(binding, directive);
1037 self.legacy_import_macro(
1044 struct_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("try an outer attribute: `#[macro_use]`").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_assoc_item(&mut self, item: &'b AssocItem, ctxt: AssocCtxt) {
1238 let parent = self.parent_scope.module;
1240 if let AssocItemKind::Macro(_) = item.kind {
1241 self.visit_invoc(item.id);
1245 if let AssocCtxt::Impl = ctxt {
1246 self.resolve_visibility(&item.vis);
1247 visit::walk_assoc_item(self, item, ctxt);
1251 // Add the item to the trait info.
1252 let item_def_id = self.r.definitions.local_def_id(item.id);
1253 let (res, ns) = match item.kind {
1254 AssocItemKind::Static(..) // Let's pretend it's a `const` for recovery.
1255 | AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
1256 AssocItemKind::Fn(_, ref sig, _, _) => {
1257 if sig.decl.has_self() {
1258 self.r.has_self.insert(item_def_id);
1260 (Res::Def(DefKind::Method, item_def_id), ValueNS)
1262 AssocItemKind::TyAlias(..) => (Res::Def(DefKind::AssocTy, item_def_id), TypeNS),
1263 AssocItemKind::Macro(_) => bug!(), // handled above
1266 let vis = ty::Visibility::Public;
1267 let expansion = self.parent_scope.expansion;
1268 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
1270 visit::walk_assoc_item(self, item, ctxt);
1273 fn visit_token(&mut self, t: Token) {
1274 if let token::Interpolated(nt) = t.kind {
1275 if let token::NtExpr(ref expr) = *nt {
1276 if let ast::ExprKind::Mac(..) = expr.kind {
1277 self.visit_invoc(expr.id);
1283 fn visit_attribute(&mut self, attr: &'b ast::Attribute) {
1284 if !attr.is_doc_comment() && attr::is_builtin_attr(attr) {
1287 .push((attr.get_normal_item().path.segments[0].ident, self.parent_scope));
1289 visit::walk_attribute(self, attr);
1292 fn visit_arm(&mut self, arm: &'b ast::Arm) {
1293 if arm.is_placeholder {
1294 self.visit_invoc(arm.id);
1296 visit::walk_arm(self, arm);
1300 fn visit_field(&mut self, f: &'b ast::Field) {
1301 if f.is_placeholder {
1302 self.visit_invoc(f.id);
1304 visit::walk_field(self, f);
1308 fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
1309 if fp.is_placeholder {
1310 self.visit_invoc(fp.id);
1312 visit::walk_field_pattern(self, fp);
1316 fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
1317 if param.is_placeholder {
1318 self.visit_invoc(param.id);
1320 visit::walk_generic_param(self, param);
1324 fn visit_param(&mut self, p: &'b ast::Param) {
1325 if p.is_placeholder {
1326 self.visit_invoc(p.id);
1328 visit::walk_param(self, p);
1332 fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
1333 if sf.is_placeholder {
1334 self.visit_invoc(sf.id);
1336 self.resolve_visibility(&sf.vis);
1337 visit::walk_struct_field(self, sf);
1341 // Constructs the reduced graph for one variant. Variants exist in the
1342 // type and value namespaces.
1343 fn visit_variant(&mut self, variant: &'b ast::Variant) {
1344 if variant.is_placeholder {
1345 self.visit_invoc(variant.id);
1349 let parent = self.parent_scope.module;
1350 let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
1351 let expn_id = self.parent_scope.expansion;
1352 let ident = variant.ident;
1354 // Define a name in the type namespace.
1355 let def_id = self.r.definitions.local_def_id(variant.id);
1356 let res = Res::Def(DefKind::Variant, def_id);
1357 self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
1359 // If the variant is marked as non_exhaustive then lower the visibility to within the
1361 let mut ctor_vis = vis;
1362 let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
1363 if has_non_exhaustive && vis == ty::Visibility::Public {
1364 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
1367 // Define a constructor name in the value namespace.
1368 // Braced variants, unlike structs, generate unusable names in
1369 // value namespace, they are reserved for possible future use.
1370 // It's ok to use the variant's id as a ctor id since an
1371 // error will be reported on any use of such resolution anyway.
1372 let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
1373 let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
1374 let ctor_kind = CtorKind::from_ast(&variant.data);
1375 let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1376 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
1378 visit::walk_variant(self, variant);