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_data_structures::sync::Lrc;
24 use rustc_error_codes::*;
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};
39 use syntax::token::{self, Token};
40 use syntax::visit::{self, Visitor};
46 type Res = def::Res<NodeId>;
48 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, ExpnId) {
49 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
50 arenas.alloc_name_binding(NameBinding {
51 kind: NameBindingKind::Module(self.0),
60 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId) {
61 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
62 arenas.alloc_name_binding(NameBinding {
63 kind: NameBindingKind::Res(self.0, false),
74 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId, IsMacroExport) {
75 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
76 arenas.alloc_name_binding(NameBinding {
77 kind: NameBindingKind::Res(self.0, true),
86 impl<'a> Resolver<'a> {
87 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
88 /// otherwise, reports an error.
89 crate fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T)
93 let binding = def.to_name_binding(self.arenas);
94 let key = self.new_key(ident, ns);
95 if let Err(old_binding) = self.try_define(parent, key, binding) {
96 self.report_conflict(parent, ident, ns, old_binding, &binding);
100 crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
101 if def_id.krate == LOCAL_CRATE {
102 return self.module_map[&def_id];
105 if let Some(&module) = self.extern_module_map.get(&def_id) {
109 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
110 (self.cstore().crate_name_untracked(def_id.krate), None)
112 let def_key = self.cstore().def_key(def_id);
114 def_key.disambiguated_data.data.get_opt_name().unwrap(),
115 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })),
119 let kind = ModuleKind::Def(DefKind::Mod, def_id, name);
120 let module = self.arenas.alloc_module(ModuleData::new(
127 self.extern_module_map.insert(def_id, module);
131 crate fn macro_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> {
132 let def_id = match self.macro_defs.get(&expn_id) {
133 Some(def_id) => *def_id,
134 None => return self.ast_transform_scopes.get(&expn_id).unwrap_or(&self.graph_root),
136 if let Some(id) = self.definitions.as_local_node_id(def_id) {
137 self.local_macro_def_scopes[&id]
139 let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
140 self.get_module(module_def_id)
144 crate fn get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
146 Res::Def(DefKind::Macro(..), def_id) => self.get_macro_by_def_id(def_id),
147 Res::NonMacroAttr(attr_kind) => Some(self.non_macro_attr(attr_kind.is_used())),
152 crate fn get_macro_by_def_id(&mut self, def_id: DefId) -> Option<Lrc<SyntaxExtension>> {
153 if let Some(ext) = self.macro_map.get(&def_id) {
154 return Some(ext.clone());
157 let ext = Lrc::new(match self.cstore().load_macro_untracked(def_id, &self.session) {
158 LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition),
159 LoadedMacro::ProcMacro(ext) => ext,
162 self.macro_map.insert(def_id, ext.clone());
166 crate fn build_reduced_graph(
168 fragment: &AstFragment,
169 parent_scope: ParentScope<'a>,
170 ) -> LegacyScope<'a> {
171 collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
172 let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
173 fragment.visit_with(&mut visitor);
174 visitor.parent_scope.legacy
177 crate fn build_reduced_graph_external(&mut self, module: Module<'a>) {
178 let def_id = module.def_id().expect("unpopulated module without a def-id");
179 for child in self.cstore().item_children_untracked(def_id, self.session) {
180 let child = child.map_id(|_| panic!("unexpected id"));
181 BuildReducedGraphVisitor { r: self, parent_scope: ParentScope::module(module) }
182 .build_reduced_graph_for_external_crate_res(child);
187 struct BuildReducedGraphVisitor<'a, 'b> {
188 r: &'b mut Resolver<'a>,
189 parent_scope: ParentScope<'a>,
192 impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> {
193 fn as_mut(&mut self) -> &mut Resolver<'a> {
198 impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
199 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
200 self.resolve_visibility_speculative(vis, false).unwrap_or_else(|err| {
201 self.r.report_vis_error(err);
202 ty::Visibility::Public
206 fn resolve_visibility_speculative<'ast>(
208 vis: &'ast ast::Visibility,
210 ) -> Result<ty::Visibility, VisResolutionError<'ast>> {
211 let parent_scope = &self.parent_scope;
213 ast::VisibilityKind::Public => Ok(ty::Visibility::Public),
214 ast::VisibilityKind::Crate(..) => {
215 Ok(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)))
217 ast::VisibilityKind::Inherited => {
218 Ok(ty::Visibility::Restricted(parent_scope.module.normal_ancestor_id))
220 ast::VisibilityKind::Restricted { ref path, id, .. } => {
221 // For visibilities we are not ready to provide correct implementation of "uniform
222 // paths" right now, so on 2018 edition we only allow module-relative paths for now.
223 // On 2015 edition visibilities are resolved as crate-relative by default,
224 // so we are prepending a root segment if necessary.
225 let ident = path.segments.get(0).expect("empty path in visibility").ident;
226 let crate_root = if ident.is_path_segment_keyword() {
228 } else if ident.span.rust_2015() {
229 Some(Segment::from_ident(Ident::new(
231 path.span.shrink_to_lo().with_ctxt(ident.span.ctxt()),
234 return Err(VisResolutionError::Relative2018(ident.span, path));
237 let segments = crate_root
239 .chain(path.segments.iter().map(|seg| seg.into()))
240 .collect::<Vec<_>>();
241 let expected_found_error = |res| {
242 Err(VisResolutionError::ExpectedFound(
244 Segment::names_to_string(&segments),
248 match self.r.resolve_path(
254 CrateLint::SimplePath(id),
256 PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
257 let res = module.res().expect("visibility resolved to unnamed block");
259 self.r.record_partial_res(id, PartialRes::new(res));
261 if module.is_normal() {
263 Ok(ty::Visibility::Public)
265 let vis = ty::Visibility::Restricted(res.def_id());
266 if self.r.is_accessible_from(vis, parent_scope.module) {
269 Err(VisResolutionError::AncestorOnly(path.span))
273 expected_found_error(res)
276 PathResult::Module(..) => Err(VisResolutionError::ModuleOnly(path.span)),
277 PathResult::NonModule(partial_res) => {
278 expected_found_error(partial_res.base_res())
280 PathResult::Failed { span, label, suggestion, .. } => {
281 Err(VisResolutionError::FailedToResolve(span, label, suggestion))
283 PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
289 fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
290 let field_names = vdata
293 .map(|field| respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name)))
295 self.insert_field_names(def_id, field_names);
298 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Name>>) {
299 if !field_names.is_empty() {
300 self.r.field_names.insert(def_id, field_names);
304 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
305 // If any statements are items, we need to create an anonymous module
306 block.stmts.iter().any(|statement| match statement.kind {
307 StmtKind::Item(_) | StmtKind::Mac(_) => true,
312 // Add an import directive to the current module.
313 fn add_import_directive(
315 module_path: Vec<Segment>,
316 subclass: ImportDirectiveSubclass<'a>,
324 let current_module = self.parent_scope.module;
325 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
326 parent_scope: self.parent_scope,
328 imported_module: Cell::new(None),
333 use_span_with_attributes: item.span_with_attributes(),
334 has_attributes: !item.attrs.is_empty(),
338 used: Cell::new(false),
341 debug!("add_import_directive({:?})", directive);
343 self.r.indeterminate_imports.push(directive);
344 match directive.subclass {
345 // Don't add unresolved underscore imports to modules
346 SingleImport { target: Ident { name: kw::Underscore, .. }, .. } => {}
347 SingleImport { target, type_ns_only, .. } => {
348 self.r.per_ns(|this, ns| {
349 if !type_ns_only || ns == TypeNS {
350 let key = this.new_key(target, ns);
351 let mut resolution = this.resolution(current_module, key).borrow_mut();
352 resolution.add_single_import(directive);
356 // We don't add prelude imports to the globs since they only affect lexical scopes,
357 // which are not relevant to import resolution.
358 GlobImport { is_prelude: true, .. } => {}
359 GlobImport { .. } => current_module.globs.borrow_mut().push(directive),
364 fn build_reduced_graph_for_use_tree(
366 // This particular use tree
367 use_tree: &ast::UseTree,
369 parent_prefix: &[Segment],
371 // The whole `use` item
377 "build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})",
378 parent_prefix, use_tree, nested
381 let mut prefix_iter = parent_prefix
384 .chain(use_tree.prefix.segments.iter().map(|seg| seg.into()))
387 // On 2015 edition imports are resolved as crate-relative by default,
388 // so prefixes are prepended with crate root segment if necessary.
389 // The root is prepended lazily, when the first non-empty prefix or terminating glob
390 // appears, so imports in braced groups can have roots prepended independently.
391 let is_glob = if let ast::UseTreeKind::Glob = use_tree.kind { true } else { false };
392 let crate_root = match prefix_iter.peek() {
393 Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => {
394 Some(seg.ident.span.ctxt())
396 None if is_glob && use_tree.span.rust_2015() => Some(use_tree.span.ctxt()),
400 Segment::from_ident(Ident::new(
402 use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt),
406 let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>();
407 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
409 let empty_for_self = |prefix: &[Segment]| {
410 prefix.is_empty() || prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot
412 match use_tree.kind {
413 ast::UseTreeKind::Simple(rename, ..) => {
414 let mut ident = use_tree.ident();
415 let mut module_path = prefix;
416 let mut source = module_path.pop().unwrap();
417 let mut type_ns_only = false;
420 // Correctly handle `self`
421 if source.ident.name == kw::SelfLower {
424 if empty_for_self(&module_path) {
427 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix,
432 // Replace `use foo::self;` with `use foo;`
433 source = module_path.pop().unwrap();
434 if rename.is_none() {
435 ident = source.ident;
440 if source.ident.name == kw::SelfLower {
443 ResolutionError::SelfImportsOnlyAllowedWithin,
447 // Disallow `use $crate;`
448 if source.ident.name == kw::DollarCrate && module_path.is_empty() {
449 let crate_root = self.r.resolve_crate_root(source.ident);
450 let crate_name = match crate_root.kind {
451 ModuleKind::Def(.., name) => name,
452 ModuleKind::Block(..) => unreachable!(),
454 // HACK(eddyb) unclear how good this is, but keeping `$crate`
455 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
456 // while the current crate doesn't have a valid `crate_name`.
457 if crate_name != kw::Invalid {
458 // `crate_name` should not be interpreted as relative.
459 module_path.push(Segment {
460 ident: Ident { name: kw::PathRoot, span: source.ident.span },
461 id: Some(self.r.next_node_id()),
463 source.ident.name = crate_name;
465 if rename.is_none() {
466 ident.name = crate_name;
471 .struct_span_err(item.span, "`$crate` may not be imported")
476 if ident.name == kw::Crate {
477 self.r.session.span_err(
479 "crate root imports need to be explicitly named: \
480 `use crate as name;`",
484 let subclass = SingleImport {
485 source: source.ident,
487 source_bindings: PerNS {
488 type_ns: Cell::new(Err(Determinacy::Undetermined)),
489 value_ns: Cell::new(Err(Determinacy::Undetermined)),
490 macro_ns: Cell::new(Err(Determinacy::Undetermined)),
492 target_bindings: PerNS {
493 type_ns: Cell::new(None),
494 value_ns: Cell::new(None),
495 macro_ns: Cell::new(None),
500 self.add_import_directive(
511 ast::UseTreeKind::Glob => {
512 let subclass = GlobImport {
513 is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
514 max_vis: Cell::new(ty::Visibility::Invisible),
516 self.add_import_directive(
527 ast::UseTreeKind::Nested(ref items) => {
528 // Ensure there is at most one `self` in the list
529 let self_spans = items
531 .filter_map(|&(ref use_tree, _)| {
532 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
533 if use_tree.ident().name == kw::SelfLower {
534 return Some(use_tree.span);
540 .collect::<Vec<_>>();
541 if self_spans.len() > 1 {
542 let mut e = self.r.into_struct_error(
544 ResolutionError::SelfImportCanOnlyAppearOnceInTheList,
547 for other_span in self_spans.iter().skip(1) {
548 e.span_label(*other_span, "another `self` import appears here");
554 for &(ref tree, id) in items {
555 self.build_reduced_graph_for_use_tree(
556 // This particular use tree
557 tree, id, &prefix, true, // The whole `use` item
558 item, vis, root_span,
562 // Empty groups `a::b::{}` are turned into synthetic `self` imports
563 // `a::b::c::{self as _}`, so that their prefixes are correctly
564 // resolved and checked for privacy/stability/etc.
565 if items.is_empty() && !empty_for_self(&prefix) {
566 let new_span = prefix[prefix.len() - 1].ident.span;
567 let tree = ast::UseTree {
568 prefix: ast::Path::from_ident(Ident::new(kw::SelfLower, new_span)),
569 kind: ast::UseTreeKind::Simple(
570 Some(Ident::new(kw::Underscore, new_span)),
576 self.build_reduced_graph_for_use_tree(
577 // This particular use tree
582 // The whole `use` item
584 ty::Visibility::Invisible,
592 /// Constructs the reduced graph for one item.
593 fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
594 let parent_scope = &self.parent_scope;
595 let parent = parent_scope.module;
596 let expansion = parent_scope.expansion;
597 let ident = item.ident;
599 let vis = self.resolve_visibility(&item.vis);
602 ItemKind::Use(ref use_tree) => {
603 self.build_reduced_graph_for_use_tree(
604 // This particular use tree
609 // The whole `use` item
616 ItemKind::ExternCrate(orig_name) => {
617 let module = if orig_name.is_none() && ident.name == kw::SelfLower {
620 .struct_span_err(item.span, "`extern crate self;` requires renaming")
624 "extern crate self as name;".into(),
625 Applicability::HasPlaceholders,
629 } else if orig_name == Some(kw::SelfLower) {
633 self.r.crate_loader.process_extern_crate(item, &self.r.definitions);
634 self.r.extern_crate_map.insert(item.id, crate_id);
635 self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
638 let used = self.process_legacy_macro_imports(item, module);
640 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
641 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
644 parent_scope: self.parent_scope,
645 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
646 subclass: ImportDirectiveSubclass::ExternCrate {
650 has_attributes: !item.attrs.is_empty(),
651 use_span_with_attributes: item.span_with_attributes(),
653 root_span: item.span,
655 module_path: Vec::new(),
657 used: Cell::new(used),
659 self.r.potentially_unused_imports.push(directive);
660 let imported_binding = self.r.import(binding, directive);
661 if ptr::eq(parent, self.r.graph_root) {
662 if let Some(entry) = self.r.extern_prelude.get(&ident.modern()) {
663 if expansion != ExpnId::root()
664 && orig_name.is_some()
665 && entry.extern_crate_item.is_none()
667 let msg = "macro-expanded `extern crate` items cannot \
668 shadow names passed with `--extern`";
669 self.r.session.span_err(item.span, msg);
673 self.r.extern_prelude.entry(ident.modern()).or_insert(ExternPreludeEntry {
674 extern_crate_item: None,
675 introduced_by_item: true,
677 entry.extern_crate_item = Some(imported_binding);
678 if orig_name.is_some() {
679 entry.introduced_by_item = true;
682 self.r.define(parent, ident, TypeNS, imported_binding);
685 ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
687 ItemKind::Mod(..) => {
688 let def_id = self.r.definitions.local_def_id(item.id);
689 let module_kind = ModuleKind::Def(DefKind::Mod, def_id, ident.name);
690 let module = self.r.arenas.alloc_module(ModuleData {
691 no_implicit_prelude: parent.no_implicit_prelude || {
692 attr::contains_name(&item.attrs, sym::no_implicit_prelude)
694 ..ModuleData::new(Some(parent), module_kind, def_id, expansion, item.span)
696 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
697 self.r.module_map.insert(def_id, module);
699 // Descend into the module.
700 self.parent_scope.module = module;
703 // These items live in the value namespace.
704 ItemKind::Static(..) => {
705 let res = Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id));
706 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
708 ItemKind::Const(..) => {
709 let res = Res::Def(DefKind::Const, self.r.definitions.local_def_id(item.id));
710 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
712 ItemKind::Fn(..) => {
713 let res = Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id));
714 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
716 // Functions introducing procedural macros reserve a slot
717 // in the macro namespace as well (see #52225).
718 self.define_macro(item);
721 // These items live in the type namespace.
722 ItemKind::TyAlias(ref ty, _) => {
723 let def_kind = match ty.kind.opaque_top_hack() {
724 None => DefKind::TyAlias,
725 Some(_) => DefKind::OpaqueTy,
727 let res = Res::Def(def_kind, self.r.definitions.local_def_id(item.id));
728 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
731 ItemKind::Enum(_, _) => {
732 let def_id = self.r.definitions.local_def_id(item.id);
733 self.r.variant_vis.insert(def_id, vis);
734 let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
735 let module = self.r.new_module(
738 parent.normal_ancestor_id,
742 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
743 self.parent_scope.module = module;
746 ItemKind::TraitAlias(..) => {
747 let res = Res::Def(DefKind::TraitAlias, self.r.definitions.local_def_id(item.id));
748 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
751 // These items live in both the type and value namespaces.
752 ItemKind::Struct(ref vdata, _) => {
753 // Define a name in the type namespace.
754 let def_id = self.r.definitions.local_def_id(item.id);
755 let res = Res::Def(DefKind::Struct, def_id);
756 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
758 // Record field names for error reporting.
759 self.insert_field_names_local(def_id, vdata);
761 // If this is a tuple or unit struct, define a name
762 // in the value namespace as well.
763 if let Some(ctor_node_id) = vdata.ctor_id() {
764 let mut ctor_vis = vis;
765 // If the structure is marked as non_exhaustive then lower the visibility
766 // to within the crate.
767 if vis == ty::Visibility::Public
768 && attr::contains_name(&item.attrs, sym::non_exhaustive)
770 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
772 for field in vdata.fields() {
773 // NOTE: The field may be an expansion placeholder, but expansion sets
774 // correct visibilities for unnamed field placeholders specifically, so the
775 // constructor visibility should still be determined correctly.
776 if let Ok(field_vis) = self.resolve_visibility_speculative(&field.vis, true)
778 if ctor_vis.is_at_least(field_vis, &*self.r) {
779 ctor_vis = field_vis;
783 let ctor_res = Res::Def(
784 DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(vdata)),
785 self.r.definitions.local_def_id(ctor_node_id),
787 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
788 self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis));
792 ItemKind::Union(ref vdata, _) => {
793 let def_id = self.r.definitions.local_def_id(item.id);
794 let res = Res::Def(DefKind::Union, def_id);
795 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
797 // Record field names for error reporting.
798 self.insert_field_names_local(def_id, vdata);
801 ItemKind::Trait(..) => {
802 let def_id = self.r.definitions.local_def_id(item.id);
804 // Add all the items within to a new module.
805 let module_kind = ModuleKind::Def(DefKind::Trait, def_id, ident.name);
806 let module = self.r.new_module(
809 parent.normal_ancestor_id,
813 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
814 self.parent_scope.module = module;
817 // These items do not add names to modules.
818 ItemKind::Impl { .. } | ItemKind::ForeignMod(..) | ItemKind::GlobalAsm(..) => {}
820 ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
824 /// Constructs the reduced graph for one foreign item.
825 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
826 let (res, ns) = match item.kind {
827 ForeignItemKind::Fn(..) => {
828 (Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id)), ValueNS)
830 ForeignItemKind::Static(..) => {
831 (Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id)), ValueNS)
833 ForeignItemKind::Ty => {
834 (Res::Def(DefKind::ForeignTy, self.r.definitions.local_def_id(item.id)), TypeNS)
836 ForeignItemKind::Macro(_) => unreachable!(),
838 let parent = self.parent_scope.module;
839 let expansion = self.parent_scope.expansion;
840 let vis = self.resolve_visibility(&item.vis);
841 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
844 fn build_reduced_graph_for_block(&mut self, block: &Block) {
845 let parent = self.parent_scope.module;
846 let expansion = self.parent_scope.expansion;
847 if self.block_needs_anonymous_module(block) {
848 let module = self.r.new_module(
850 ModuleKind::Block(block.id),
851 parent.normal_ancestor_id,
855 self.r.block_map.insert(block.id, module);
856 self.parent_scope.module = module; // Descend into the block.
860 /// Builds the reduced graph for a single item in an external crate.
861 fn build_reduced_graph_for_external_crate_res(&mut self, child: Export<NodeId>) {
862 let parent = self.parent_scope.module;
863 let Export { ident, res, vis, span } = child;
864 let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
865 // Record primary definitions.
867 Res::Def(kind @ DefKind::Mod, def_id)
868 | Res::Def(kind @ DefKind::Enum, def_id)
869 | Res::Def(kind @ DefKind::Trait, def_id) => {
870 let module = self.r.new_module(
872 ModuleKind::Def(kind, def_id, ident.name),
877 self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
879 Res::Def(DefKind::Struct, _)
880 | Res::Def(DefKind::Union, _)
881 | Res::Def(DefKind::Variant, _)
882 | Res::Def(DefKind::TyAlias, _)
883 | Res::Def(DefKind::ForeignTy, _)
884 | Res::Def(DefKind::OpaqueTy, _)
885 | Res::Def(DefKind::TraitAlias, _)
886 | Res::Def(DefKind::AssocTy, _)
887 | Res::Def(DefKind::AssocOpaqueTy, _)
889 | Res::ToolMod => self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
890 Res::Def(DefKind::Fn, _)
891 | Res::Def(DefKind::Method, _)
892 | Res::Def(DefKind::Static, _)
893 | Res::Def(DefKind::Const, _)
894 | Res::Def(DefKind::AssocConst, _)
895 | Res::Def(DefKind::Ctor(..), _) => {
896 self.r.define(parent, ident, ValueNS, (res, vis, span, expansion))
898 Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
899 self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
901 Res::Def(DefKind::TyParam, _)
902 | Res::Def(DefKind::ConstParam, _)
906 | Res::Err => bug!("unexpected resolution: {:?}", res),
908 // Record some extra data for better diagnostics.
909 let cstore = self.r.cstore();
911 Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
912 let field_names = cstore.struct_field_names_untracked(def_id, self.r.session);
913 self.insert_field_names(def_id, field_names);
915 Res::Def(DefKind::Method, def_id) => {
916 if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
917 self.r.has_self.insert(def_id);
920 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
921 let parent = cstore.def_key(def_id).parent;
922 if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
923 self.r.struct_constructors.insert(struct_def_id, (res, vis));
930 fn legacy_import_macro(
933 binding: &'a NameBinding<'a>,
935 allow_shadowing: bool,
937 if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
938 let msg = format!("`{}` is already in scope", name);
940 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
941 self.r.session.struct_span_err(span, &msg).note(note).emit();
945 /// Returns `true` if we should consider the underlying `extern crate` to be used.
946 fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
947 let mut import_all = None;
948 let mut single_imports = Vec::new();
949 for attr in &item.attrs {
950 if attr.check_name(sym::macro_use) {
951 if self.parent_scope.module.parent.is_some() {
956 "an `extern crate` loading macros must be at the crate root"
960 if let ItemKind::ExternCrate(Some(orig_name)) = item.kind {
961 if orig_name == kw::SelfLower {
966 "`#[macro_use]` is not supported on `extern crate self`",
972 |span| struct_span_err!(self.r.session, span, E0466, "bad macro import").emit();
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 struct_span_err!(self.r.session, ident.span, E0469, "imported macro not found")
1050 import_all.is_some() || !single_imports.is_empty()
1053 /// Returns `true` if this attribute list contains `macro_use`.
1054 fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool {
1056 if attr.check_name(sym::macro_escape) {
1057 let msg = "`#[macro_escape]` is a deprecated synonym for `#[macro_use]`";
1058 let mut err = self.r.session.struct_span_warn(attr.span, msg);
1059 if let ast::AttrStyle::Inner = attr.style {
1060 err.help("try an outer attribute: `#[macro_use]`").emit();
1064 } else if !attr.check_name(sym::macro_use) {
1068 if !attr.is_word() {
1069 self.r.session.span_err(attr.span, "arguments to `macro_use` are not allowed here");
1077 fn visit_invoc(&mut self, id: NodeId) -> LegacyScope<'a> {
1078 let invoc_id = id.placeholder_to_expn_id();
1080 self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id);
1082 let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope);
1083 assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation");
1085 LegacyScope::Invocation(invoc_id)
1088 fn proc_macro_stub(item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
1089 if attr::contains_name(&item.attrs, sym::proc_macro) {
1090 return Some((MacroKind::Bang, item.ident, item.span));
1091 } else if attr::contains_name(&item.attrs, sym::proc_macro_attribute) {
1092 return Some((MacroKind::Attr, item.ident, item.span));
1093 } else if let Some(attr) = attr::find_by_name(&item.attrs, sym::proc_macro_derive) {
1094 if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
1095 if let Some(ident) = nested_meta.ident() {
1096 return Some((MacroKind::Derive, ident, ident.span));
1103 // Mark the given macro as unused unless its name starts with `_`.
1104 // Macro uses will remove items from this set, and the remaining
1105 // items will be reported as `unused_macros`.
1106 fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) {
1107 if !ident.as_str().starts_with("_") {
1108 self.r.unused_macros.insert(node_id, span);
1112 fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> {
1113 let parent_scope = self.parent_scope;
1114 let expansion = parent_scope.expansion;
1115 let (ext, ident, span, is_legacy) = match &item.kind {
1116 ItemKind::MacroDef(def) => {
1117 let ext = Lrc::new(self.r.compile_macro(item, self.r.session.edition()));
1118 (ext, item.ident, item.span, def.legacy)
1120 ItemKind::Fn(..) => match Self::proc_macro_stub(item) {
1121 Some((macro_kind, ident, span)) => {
1122 self.r.proc_macro_stubs.insert(item.id);
1123 (self.r.dummy_ext(macro_kind), ident, span, false)
1125 None => return parent_scope.legacy,
1127 _ => unreachable!(),
1130 let def_id = self.r.definitions.local_def_id(item.id);
1131 let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id);
1132 self.r.macro_map.insert(def_id, ext);
1133 self.r.local_macro_def_scopes.insert(item.id, parent_scope.module);
1136 let ident = ident.modern();
1137 self.r.macro_names.insert(ident);
1138 let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
1139 let vis = if is_macro_export {
1140 ty::Visibility::Public
1142 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
1144 let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas);
1145 self.r.set_binding_parent_module(binding, parent_scope.module);
1146 self.r.all_macros.insert(ident.name, res);
1147 if is_macro_export {
1148 let module = self.r.graph_root;
1149 self.r.define(module, ident, MacroNS, (res, vis, span, expansion, IsMacroExport));
1151 self.r.check_reserved_macro_name(ident, res);
1152 self.insert_unused_macro(ident, item.id, span);
1154 LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding {
1155 parent_legacy_scope: parent_scope.legacy,
1160 let module = parent_scope.module;
1161 let vis = self.resolve_visibility(&item.vis);
1162 if vis != ty::Visibility::Public {
1163 self.insert_unused_macro(ident, item.id, span);
1165 self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
1166 self.parent_scope.legacy
1171 macro_rules! method {
1172 ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => {
1173 fn $visit(&mut self, node: &'b $ty) {
1174 if let $invoc(..) = node.kind {
1175 self.visit_invoc(node.id);
1177 visit::$walk(self, node);
1183 impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
1184 method!(visit_expr: ast::Expr, ast::ExprKind::Mac, walk_expr);
1185 method!(visit_pat: ast::Pat, ast::PatKind::Mac, walk_pat);
1186 method!(visit_ty: ast::Ty, ast::TyKind::Mac, walk_ty);
1188 fn visit_item(&mut self, item: &'b Item) {
1189 let macro_use = match item.kind {
1190 ItemKind::MacroDef(..) => {
1191 self.parent_scope.legacy = self.define_macro(item);
1194 ItemKind::Mac(..) => {
1195 self.parent_scope.legacy = self.visit_invoc(item.id);
1198 ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
1201 let orig_current_module = self.parent_scope.module;
1202 let orig_current_legacy_scope = self.parent_scope.legacy;
1203 self.build_reduced_graph_for_item(item);
1204 visit::walk_item(self, item);
1205 self.parent_scope.module = orig_current_module;
1207 self.parent_scope.legacy = orig_current_legacy_scope;
1211 fn visit_stmt(&mut self, stmt: &'b ast::Stmt) {
1212 if let ast::StmtKind::Mac(..) = stmt.kind {
1213 self.parent_scope.legacy = self.visit_invoc(stmt.id);
1215 visit::walk_stmt(self, stmt);
1219 fn visit_foreign_item(&mut self, foreign_item: &'b ForeignItem) {
1220 if let ForeignItemKind::Macro(_) = foreign_item.kind {
1221 self.visit_invoc(foreign_item.id);
1225 self.build_reduced_graph_for_foreign_item(foreign_item);
1226 visit::walk_foreign_item(self, foreign_item);
1229 fn visit_block(&mut self, block: &'b Block) {
1230 let orig_current_module = self.parent_scope.module;
1231 let orig_current_legacy_scope = self.parent_scope.legacy;
1232 self.build_reduced_graph_for_block(block);
1233 visit::walk_block(self, block);
1234 self.parent_scope.module = orig_current_module;
1235 self.parent_scope.legacy = orig_current_legacy_scope;
1238 fn visit_trait_item(&mut self, item: &'b AssocItem) {
1239 let parent = self.parent_scope.module;
1241 if let AssocItemKind::Macro(_) = item.kind {
1242 self.visit_invoc(item.id);
1246 // Add the item to the trait info.
1247 let item_def_id = self.r.definitions.local_def_id(item.id);
1248 let (res, ns) = match item.kind {
1249 AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
1250 AssocItemKind::Fn(ref sig, _) => {
1251 if sig.decl.has_self() {
1252 self.r.has_self.insert(item_def_id);
1254 (Res::Def(DefKind::Method, item_def_id), ValueNS)
1256 AssocItemKind::TyAlias(..) => (Res::Def(DefKind::AssocTy, item_def_id), TypeNS),
1257 AssocItemKind::Macro(_) => bug!(), // handled above
1260 let vis = ty::Visibility::Public;
1261 let expansion = self.parent_scope.expansion;
1262 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
1264 visit::walk_trait_item(self, item);
1267 fn visit_impl_item(&mut self, item: &'b ast::AssocItem) {
1268 if let ast::AssocItemKind::Macro(..) = item.kind {
1269 self.visit_invoc(item.id);
1271 self.resolve_visibility(&item.vis);
1272 visit::walk_impl_item(self, item);
1276 fn visit_token(&mut self, t: Token) {
1277 if let token::Interpolated(nt) = t.kind {
1278 if let token::NtExpr(ref expr) = *nt {
1279 if let ast::ExprKind::Mac(..) = expr.kind {
1280 self.visit_invoc(expr.id);
1286 fn visit_attribute(&mut self, attr: &'b ast::Attribute) {
1287 if !attr.is_doc_comment() && attr::is_builtin_attr(attr) {
1290 .push((attr.get_normal_item().path.segments[0].ident, self.parent_scope));
1292 visit::walk_attribute(self, attr);
1295 fn visit_arm(&mut self, arm: &'b ast::Arm) {
1296 if arm.is_placeholder {
1297 self.visit_invoc(arm.id);
1299 visit::walk_arm(self, arm);
1303 fn visit_field(&mut self, f: &'b ast::Field) {
1304 if f.is_placeholder {
1305 self.visit_invoc(f.id);
1307 visit::walk_field(self, f);
1311 fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
1312 if fp.is_placeholder {
1313 self.visit_invoc(fp.id);
1315 visit::walk_field_pattern(self, fp);
1319 fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
1320 if param.is_placeholder {
1321 self.visit_invoc(param.id);
1323 visit::walk_generic_param(self, param);
1327 fn visit_param(&mut self, p: &'b ast::Param) {
1328 if p.is_placeholder {
1329 self.visit_invoc(p.id);
1331 visit::walk_param(self, p);
1335 fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
1336 if sf.is_placeholder {
1337 self.visit_invoc(sf.id);
1339 self.resolve_visibility(&sf.vis);
1340 visit::walk_struct_field(self, sf);
1344 // Constructs the reduced graph for one variant. Variants exist in the
1345 // type and value namespaces.
1346 fn visit_variant(&mut self, variant: &'b ast::Variant) {
1347 if variant.is_placeholder {
1348 self.visit_invoc(variant.id);
1352 let parent = self.parent_scope.module;
1353 let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
1354 let expn_id = self.parent_scope.expansion;
1355 let ident = variant.ident;
1357 // Define a name in the type namespace.
1358 let def_id = self.r.definitions.local_def_id(variant.id);
1359 let res = Res::Def(DefKind::Variant, def_id);
1360 self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
1362 // If the variant is marked as non_exhaustive then lower the visibility to within the
1364 let mut ctor_vis = vis;
1365 let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
1366 if has_non_exhaustive && vis == ty::Visibility::Public {
1367 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
1370 // Define a constructor name in the value namespace.
1371 // Braced variants, unlike structs, generate unusable names in
1372 // value namespace, they are reserved for possible future use.
1373 // It's ok to use the variant's id as a ctor id since an
1374 // error will be reported on any use of such resolution anyway.
1375 let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
1376 let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
1377 let ctor_kind = CtorKind::from_ast(&variant.data);
1378 let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1379 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
1381 visit::walk_variant(self, variant);