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::{Import, ImportKind};
10 use crate::macros::{MacroRulesBinding, MacroRulesScope};
11 use crate::Namespace::{self, MacroNS, TypeNS, ValueNS};
12 use crate::{CrateLint, Determinacy, PathResult, ResolutionError, VisResolutionError};
14 ExternPreludeEntry, ModuleOrUniformRoot, ParentScope, PerNS, Resolver, ResolverArenas,
16 use crate::{Module, ModuleData, ModuleKind, NameBinding, NameBindingKind, Segment, ToNameBinding};
18 use rustc_ast::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
19 use rustc_ast::ast::{AssocItem, AssocItemKind, MetaItemKind, StmtKind};
20 use rustc_ast::ast::{Ident, Name};
21 use rustc_ast::token::{self, Token};
22 use rustc_ast::visit::{self, AssocCtxt, Visitor};
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};
30 use rustc_metadata::creader::LoadedMacro;
31 use rustc_middle::bug;
32 use rustc_middle::hir::exports::Export;
33 use rustc_middle::middle::cstore::CrateStore;
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};
44 type Res = def::Res<NodeId>;
46 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, ExpnId) {
47 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
48 arenas.alloc_name_binding(NameBinding {
49 kind: NameBindingKind::Module(self.0),
58 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId) {
59 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
60 arenas.alloc_name_binding(NameBinding {
61 kind: NameBindingKind::Res(self.0, false),
72 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId, IsMacroExport) {
73 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
74 arenas.alloc_name_binding(NameBinding {
75 kind: NameBindingKind::Res(self.0, true),
84 impl<'a> Resolver<'a> {
85 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
86 /// otherwise, reports an error.
87 crate fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T)
91 let binding = def.to_name_binding(self.arenas);
92 let key = self.new_key(ident, ns);
93 if let Err(old_binding) = self.try_define(parent, key, binding) {
94 self.report_conflict(parent, ident, ns, old_binding, &binding);
98 crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
99 if let Some(def_id) = def_id.as_local() {
100 return self.module_map[&def_id];
103 if let Some(&module) = self.extern_module_map.get(&def_id) {
107 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
108 (self.cstore().crate_name_untracked(def_id.krate), None)
110 let def_key = self.cstore().def_key(def_id);
112 def_key.disambiguated_data.data.get_opt_name().unwrap(),
113 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })),
117 let kind = ModuleKind::Def(DefKind::Mod, def_id, name);
118 let module = self.arenas.alloc_module(ModuleData::new(
125 self.extern_module_map.insert(def_id, module);
129 crate fn macro_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> {
130 let def_id = match self.macro_defs.get(&expn_id) {
131 Some(def_id) => *def_id,
132 None => return self.ast_transform_scopes.get(&expn_id).unwrap_or(&self.graph_root),
134 if let Some(id) = self.definitions.as_local_node_id(def_id) {
135 self.local_macro_def_scopes[&id]
137 let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
138 self.get_module(module_def_id)
142 crate fn get_macro(&mut self, res: Res) -> Option<Lrc<SyntaxExtension>> {
144 Res::Def(DefKind::Macro(..), def_id) => self.get_macro_by_def_id(def_id),
145 Res::NonMacroAttr(attr_kind) => Some(self.non_macro_attr(attr_kind.is_used())),
150 crate fn get_macro_by_def_id(&mut self, def_id: DefId) -> Option<Lrc<SyntaxExtension>> {
151 if let Some(ext) = self.macro_map.get(&def_id) {
152 return Some(ext.clone());
155 let ext = Lrc::new(match self.cstore().load_macro_untracked(def_id, &self.session) {
156 LoadedMacro::MacroDef(item, edition) => self.compile_macro(&item, edition),
157 LoadedMacro::ProcMacro(ext) => ext,
160 self.macro_map.insert(def_id, ext.clone());
164 crate fn build_reduced_graph(
166 fragment: &AstFragment,
167 parent_scope: ParentScope<'a>,
168 ) -> MacroRulesScope<'a> {
169 collect_definitions(&mut self.definitions, fragment, parent_scope.expansion);
170 let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope };
171 fragment.visit_with(&mut visitor);
172 visitor.parent_scope.macro_rules
175 crate fn build_reduced_graph_external(&mut self, module: Module<'a>) {
176 let def_id = module.def_id().expect("unpopulated module without a def-id");
177 for child in self.cstore().item_children_untracked(def_id, self.session) {
178 let child = child.map_id(|_| panic!("unexpected id"));
179 BuildReducedGraphVisitor { r: self, parent_scope: ParentScope::module(module) }
180 .build_reduced_graph_for_external_crate_res(child);
185 struct BuildReducedGraphVisitor<'a, 'b> {
186 r: &'b mut Resolver<'a>,
187 parent_scope: ParentScope<'a>,
190 impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> {
191 fn as_mut(&mut self) -> &mut Resolver<'a> {
196 impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
197 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
198 self.resolve_visibility_speculative(vis, false).unwrap_or_else(|err| {
199 self.r.report_vis_error(err);
200 ty::Visibility::Public
204 fn resolve_visibility_speculative<'ast>(
206 vis: &'ast ast::Visibility,
208 ) -> Result<ty::Visibility, VisResolutionError<'ast>> {
209 let parent_scope = &self.parent_scope;
211 ast::VisibilityKind::Public => Ok(ty::Visibility::Public),
212 ast::VisibilityKind::Crate(..) => {
213 Ok(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)))
215 ast::VisibilityKind::Inherited => {
216 Ok(ty::Visibility::Restricted(parent_scope.module.normal_ancestor_id))
218 ast::VisibilityKind::Restricted { ref path, id, .. } => {
219 // For visibilities we are not ready to provide correct implementation of "uniform
220 // paths" right now, so on 2018 edition we only allow module-relative paths for now.
221 // On 2015 edition visibilities are resolved as crate-relative by default,
222 // so we are prepending a root segment if necessary.
223 let ident = path.segments.get(0).expect("empty path in visibility").ident;
224 let crate_root = if ident.is_path_segment_keyword() {
226 } else if ident.span.rust_2015() {
227 Some(Segment::from_ident(Ident::new(
229 path.span.shrink_to_lo().with_ctxt(ident.span.ctxt()),
232 return Err(VisResolutionError::Relative2018(ident.span, path));
235 let segments = crate_root
237 .chain(path.segments.iter().map(|seg| seg.into()))
238 .collect::<Vec<_>>();
239 let expected_found_error = |res| {
240 Err(VisResolutionError::ExpectedFound(
242 Segment::names_to_string(&segments),
246 match self.r.resolve_path(
252 CrateLint::SimplePath(id),
254 PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
255 let res = module.res().expect("visibility resolved to unnamed block");
257 self.r.record_partial_res(id, PartialRes::new(res));
259 if module.is_normal() {
261 Ok(ty::Visibility::Public)
263 let vis = ty::Visibility::Restricted(res.def_id());
264 if self.r.is_accessible_from(vis, parent_scope.module) {
267 Err(VisResolutionError::AncestorOnly(path.span))
271 expected_found_error(res)
274 PathResult::Module(..) => Err(VisResolutionError::ModuleOnly(path.span)),
275 PathResult::NonModule(partial_res) => {
276 expected_found_error(partial_res.base_res())
278 PathResult::Failed { span, label, suggestion, .. } => {
279 Err(VisResolutionError::FailedToResolve(span, label, suggestion))
281 PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)),
287 fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
288 let field_names = vdata
291 .map(|field| respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name)))
293 self.insert_field_names(def_id, field_names);
296 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Name>>) {
297 if !field_names.is_empty() {
298 self.r.field_names.insert(def_id, field_names);
302 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
303 // If any statements are items, we need to create an anonymous module
304 block.stmts.iter().any(|statement| match statement.kind {
305 StmtKind::Item(_) | StmtKind::MacCall(_) => true,
310 // Add an import to the current module.
313 module_path: Vec<Segment>,
314 kind: ImportKind<'a>,
322 let current_module = self.parent_scope.module;
323 let import = self.r.arenas.alloc_import(Import {
325 parent_scope: self.parent_scope,
327 imported_module: Cell::new(None),
331 use_span_with_attributes: item.span_with_attributes(),
332 has_attributes: !item.attrs.is_empty(),
336 used: Cell::new(false),
339 debug!("add_import({:?})", import);
341 self.r.indeterminate_imports.push(import);
343 // Don't add unresolved underscore imports to modules
344 ImportKind::Single { target: Ident { name: kw::Underscore, .. }, .. } => {}
345 ImportKind::Single { target, type_ns_only, .. } => {
346 self.r.per_ns(|this, ns| {
347 if !type_ns_only || ns == TypeNS {
348 let key = this.new_key(target, ns);
349 let mut resolution = this.resolution(current_module, key).borrow_mut();
350 resolution.add_single_import(import);
354 // We don't add prelude imports to the globs since they only affect lexical scopes,
355 // which are not relevant to import resolution.
356 ImportKind::Glob { is_prelude: true, .. } => {}
357 ImportKind::Glob { .. } => current_module.globs.borrow_mut().push(import),
362 fn build_reduced_graph_for_use_tree(
364 // This particular use tree
365 use_tree: &ast::UseTree,
367 parent_prefix: &[Segment],
369 // The whole `use` item
375 "build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})",
376 parent_prefix, use_tree, nested
379 let mut prefix_iter = parent_prefix
382 .chain(use_tree.prefix.segments.iter().map(|seg| seg.into()))
385 // On 2015 edition imports are resolved as crate-relative by default,
386 // so prefixes are prepended with crate root segment if necessary.
387 // The root is prepended lazily, when the first non-empty prefix or terminating glob
388 // appears, so imports in braced groups can have roots prepended independently.
389 let is_glob = if let ast::UseTreeKind::Glob = use_tree.kind { true } else { false };
390 let crate_root = match prefix_iter.peek() {
391 Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => {
392 Some(seg.ident.span.ctxt())
394 None if is_glob && use_tree.span.rust_2015() => Some(use_tree.span.ctxt()),
398 Segment::from_ident(Ident::new(
400 use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt),
404 let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>();
405 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
407 let empty_for_self = |prefix: &[Segment]| {
408 prefix.is_empty() || prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot
410 match use_tree.kind {
411 ast::UseTreeKind::Simple(rename, ..) => {
412 let mut ident = use_tree.ident();
413 let mut module_path = prefix;
414 let mut source = module_path.pop().unwrap();
415 let mut type_ns_only = false;
418 // Correctly handle `self`
419 if source.ident.name == kw::SelfLower {
422 if empty_for_self(&module_path) {
425 ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix,
430 // Replace `use foo::self;` with `use foo;`
431 source = module_path.pop().unwrap();
432 if rename.is_none() {
433 ident = source.ident;
438 if source.ident.name == kw::SelfLower {
441 ResolutionError::SelfImportsOnlyAllowedWithin,
445 // Disallow `use $crate;`
446 if source.ident.name == kw::DollarCrate && module_path.is_empty() {
447 let crate_root = self.r.resolve_crate_root(source.ident);
448 let crate_name = match crate_root.kind {
449 ModuleKind::Def(.., name) => name,
450 ModuleKind::Block(..) => unreachable!(),
452 // HACK(eddyb) unclear how good this is, but keeping `$crate`
453 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
454 // while the current crate doesn't have a valid `crate_name`.
455 if crate_name != kw::Invalid {
456 // `crate_name` should not be interpreted as relative.
457 module_path.push(Segment {
458 ident: Ident { name: kw::PathRoot, span: source.ident.span },
459 id: Some(self.r.next_node_id()),
461 source.ident.name = crate_name;
463 if rename.is_none() {
464 ident.name = crate_name;
469 .struct_span_err(item.span, "`$crate` may not be imported")
474 if ident.name == kw::Crate {
475 self.r.session.span_err(
477 "crate root imports need to be explicitly named: \
478 `use crate as name;`",
482 let kind = ImportKind::Single {
483 source: source.ident,
485 source_bindings: PerNS {
486 type_ns: Cell::new(Err(Determinacy::Undetermined)),
487 value_ns: Cell::new(Err(Determinacy::Undetermined)),
488 macro_ns: Cell::new(Err(Determinacy::Undetermined)),
490 target_bindings: PerNS {
491 type_ns: Cell::new(None),
492 value_ns: Cell::new(None),
493 macro_ns: Cell::new(None),
509 ast::UseTreeKind::Glob => {
510 let kind = ImportKind::Glob {
511 is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
512 max_vis: Cell::new(ty::Visibility::Invisible),
514 self.add_import(prefix, kind, use_tree.span, id, item, root_span, item.id, vis);
516 ast::UseTreeKind::Nested(ref items) => {
517 // Ensure there is at most one `self` in the list
518 let self_spans = items
520 .filter_map(|&(ref use_tree, _)| {
521 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
522 if use_tree.ident().name == kw::SelfLower {
523 return Some(use_tree.span);
529 .collect::<Vec<_>>();
530 if self_spans.len() > 1 {
531 let mut e = self.r.into_struct_error(
533 ResolutionError::SelfImportCanOnlyAppearOnceInTheList,
536 for other_span in self_spans.iter().skip(1) {
537 e.span_label(*other_span, "another `self` import appears here");
543 for &(ref tree, id) in items {
544 self.build_reduced_graph_for_use_tree(
545 // This particular use tree
546 tree, id, &prefix, true, // The whole `use` item
547 item, vis, root_span,
551 // Empty groups `a::b::{}` are turned into synthetic `self` imports
552 // `a::b::c::{self as _}`, so that their prefixes are correctly
553 // resolved and checked for privacy/stability/etc.
554 if items.is_empty() && !empty_for_self(&prefix) {
555 let new_span = prefix[prefix.len() - 1].ident.span;
556 let tree = ast::UseTree {
557 prefix: ast::Path::from_ident(Ident::new(kw::SelfLower, new_span)),
558 kind: ast::UseTreeKind::Simple(
559 Some(Ident::new(kw::Underscore, new_span)),
565 self.build_reduced_graph_for_use_tree(
566 // This particular use tree
571 // The whole `use` item
573 ty::Visibility::Invisible,
581 /// Constructs the reduced graph for one item.
582 fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
583 let parent_scope = &self.parent_scope;
584 let parent = parent_scope.module;
585 let expansion = parent_scope.expansion;
586 let ident = item.ident;
588 let vis = self.resolve_visibility(&item.vis);
591 ItemKind::Use(ref use_tree) => {
592 self.build_reduced_graph_for_use_tree(
593 // This particular use tree
598 // The whole `use` item
605 ItemKind::ExternCrate(orig_name) => {
606 let module = if orig_name.is_none() && ident.name == kw::SelfLower {
609 .struct_span_err(item.span, "`extern crate self;` requires renaming")
613 "extern crate self as name;".into(),
614 Applicability::HasPlaceholders,
618 } else if orig_name == Some(kw::SelfLower) {
622 self.r.crate_loader.process_extern_crate(item, &self.r.definitions);
623 self.r.extern_crate_map.insert(item.id, crate_id);
624 self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
627 let used = self.process_macro_use_imports(item, module);
629 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
630 let import = self.r.arenas.alloc_import(Import {
631 kind: ImportKind::ExternCrate { source: orig_name, target: ident },
634 parent_scope: self.parent_scope,
635 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
636 has_attributes: !item.attrs.is_empty(),
637 use_span_with_attributes: item.span_with_attributes(),
639 root_span: item.span,
641 module_path: Vec::new(),
643 used: Cell::new(used),
645 self.r.potentially_unused_imports.push(import);
646 let imported_binding = self.r.import(binding, import);
647 if ptr::eq(parent, self.r.graph_root) {
648 if let Some(entry) = self.r.extern_prelude.get(&ident.normalize_to_macros_2_0())
650 if expansion != ExpnId::root()
651 && orig_name.is_some()
652 && entry.extern_crate_item.is_none()
654 let msg = "macro-expanded `extern crate` items cannot \
655 shadow names passed with `--extern`";
656 self.r.session.span_err(item.span, msg);
660 self.r.extern_prelude.entry(ident.normalize_to_macros_2_0()).or_insert(
662 extern_crate_item: None,
663 introduced_by_item: true,
666 entry.extern_crate_item = Some(imported_binding);
667 if orig_name.is_some() {
668 entry.introduced_by_item = true;
671 self.r.define(parent, ident, TypeNS, imported_binding);
674 ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
676 ItemKind::Mod(..) => {
677 let def_id = self.r.definitions.local_def_id(item.id);
678 let module_kind = ModuleKind::Def(DefKind::Mod, def_id.to_def_id(), ident.name);
679 let module = self.r.arenas.alloc_module(ModuleData {
680 no_implicit_prelude: parent.no_implicit_prelude || {
681 attr::contains_name(&item.attrs, sym::no_implicit_prelude)
691 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
692 self.r.module_map.insert(def_id, module);
694 // Descend into the module.
695 self.parent_scope.module = module;
698 // These items live in the value namespace.
699 ItemKind::Static(..) => {
701 Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id).to_def_id());
702 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
704 ItemKind::Const(..) => {
706 Res::Def(DefKind::Const, self.r.definitions.local_def_id(item.id).to_def_id());
707 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
709 ItemKind::Fn(..) => {
711 Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id).to_def_id());
712 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
714 // Functions introducing procedural macros reserve a slot
715 // in the macro namespace as well (see #52225).
716 self.define_macro(item);
719 // These items live in the type namespace.
720 ItemKind::TyAlias(_, _, _, ref ty) => {
721 let def_kind = match ty.as_deref().and_then(|ty| ty.kind.opaque_top_hack()) {
722 None => DefKind::TyAlias,
723 Some(_) => DefKind::OpaqueTy,
725 let res = Res::Def(def_kind, self.r.definitions.local_def_id(item.id).to_def_id());
726 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
729 ItemKind::Enum(_, _) => {
730 let def_id = self.r.definitions.local_def_id(item.id).to_def_id();
731 self.r.variant_vis.insert(def_id, vis);
732 let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
733 let module = self.r.new_module(
736 parent.normal_ancestor_id,
740 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
741 self.parent_scope.module = module;
744 ItemKind::TraitAlias(..) => {
747 self.r.definitions.local_def_id(item.id).to_def_id(),
749 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
752 // These items live in both the type and value namespaces.
753 ItemKind::Struct(ref vdata, _) => {
754 // Define a name in the type namespace.
755 let def_id = self.r.definitions.local_def_id(item.id).to_def_id();
756 let res = Res::Def(DefKind::Struct, def_id);
757 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
759 // Record field names for error reporting.
760 self.insert_field_names_local(def_id, vdata);
762 // If this is a tuple or unit struct, define a name
763 // in the value namespace as well.
764 if let Some(ctor_node_id) = vdata.ctor_id() {
765 // If the structure is marked as non_exhaustive then lower the visibility
766 // to within the crate.
767 let mut ctor_vis = if vis == ty::Visibility::Public
768 && attr::contains_name(&item.attrs, sym::non_exhaustive)
770 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
775 for field in vdata.fields() {
776 // NOTE: The field may be an expansion placeholder, but expansion sets
777 // correct visibilities for unnamed field placeholders specifically, so the
778 // constructor visibility should still be determined correctly.
779 if let Ok(field_vis) = self.resolve_visibility_speculative(&field.vis, true)
781 if ctor_vis.is_at_least(field_vis, &*self.r) {
782 ctor_vis = field_vis;
786 let ctor_res = Res::Def(
787 DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(vdata)),
788 self.r.definitions.local_def_id(ctor_node_id).to_def_id(),
790 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
791 self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis));
795 ItemKind::Union(ref vdata, _) => {
796 let def_id = self.r.definitions.local_def_id(item.id).to_def_id();
797 let res = Res::Def(DefKind::Union, def_id);
798 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
800 // Record field names for error reporting.
801 self.insert_field_names_local(def_id, vdata);
804 ItemKind::Trait(..) => {
805 let def_id = self.r.definitions.local_def_id(item.id).to_def_id();
807 // Add all the items within to a new module.
808 let module_kind = ModuleKind::Def(DefKind::Trait, def_id, ident.name);
809 let module = self.r.new_module(
812 parent.normal_ancestor_id,
816 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
817 self.parent_scope.module = module;
820 // These items do not add names to modules.
821 ItemKind::Impl { .. } | ItemKind::ForeignMod(..) | ItemKind::GlobalAsm(..) => {}
823 ItemKind::MacroDef(..) | ItemKind::MacCall(_) => unreachable!(),
827 /// Constructs the reduced graph for one foreign item.
828 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
829 let (res, ns) = match item.kind {
830 ForeignItemKind::Fn(..) => (
831 Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id).to_def_id()),
834 ForeignItemKind::Static(..) => (
835 Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id).to_def_id()),
838 ForeignItemKind::TyAlias(..) => (
839 Res::Def(DefKind::ForeignTy, self.r.definitions.local_def_id(item.id).to_def_id()),
842 ForeignItemKind::MacCall(_) => unreachable!(),
844 let parent = self.parent_scope.module;
845 let expansion = self.parent_scope.expansion;
846 let vis = self.resolve_visibility(&item.vis);
847 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
850 fn build_reduced_graph_for_block(&mut self, block: &Block) {
851 let parent = self.parent_scope.module;
852 let expansion = self.parent_scope.expansion;
853 if self.block_needs_anonymous_module(block) {
854 let module = self.r.new_module(
856 ModuleKind::Block(block.id),
857 parent.normal_ancestor_id,
861 self.r.block_map.insert(block.id, module);
862 self.parent_scope.module = module; // Descend into the block.
866 /// Builds the reduced graph for a single item in an external crate.
867 fn build_reduced_graph_for_external_crate_res(&mut self, child: Export<NodeId>) {
868 let parent = self.parent_scope.module;
869 let Export { ident, res, vis, span } = child;
870 let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
871 // Record primary definitions.
873 Res::Def(kind @ (DefKind::Mod | DefKind::Enum | 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));
890 | DefKind::TraitAlias
892 | DefKind::AssocOpaqueTy,
896 | Res::ToolMod => self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
902 | DefKind::AssocConst
905 ) => self.r.define(parent, ident, ValueNS, (res, vis, span, expansion)),
906 Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
907 self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
909 Res::Def(DefKind::TyParam | DefKind::ConstParam, _)
913 | Res::Err => bug!("unexpected resolution: {:?}", res),
915 // Record some extra data for better diagnostics.
916 let cstore = self.r.cstore();
918 Res::Def(DefKind::Struct | DefKind::Union, def_id) => {
919 let field_names = cstore.struct_field_names_untracked(def_id, self.r.session);
920 self.insert_field_names(def_id, field_names);
922 Res::Def(DefKind::AssocFn, def_id) => {
924 .associated_item_cloned_untracked(def_id, self.r.session)
925 .fn_has_self_parameter
927 self.r.has_self.insert(def_id);
930 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
931 let parent = cstore.def_key(def_id).parent;
932 if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
933 self.r.struct_constructors.insert(struct_def_id, (res, vis));
940 fn add_macro_use_binding(
943 binding: &'a NameBinding<'a>,
945 allow_shadowing: bool,
947 if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
948 let msg = format!("`{}` is already in scope", name);
950 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
951 self.r.session.struct_span_err(span, &msg).note(note).emit();
955 /// Returns `true` if we should consider the underlying `extern crate` to be used.
956 fn process_macro_use_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
957 let mut import_all = None;
958 let mut single_imports = Vec::new();
959 for attr in &item.attrs {
960 if attr.check_name(sym::macro_use) {
961 if self.parent_scope.module.parent.is_some() {
966 "an `extern crate` loading macros must be at the crate root"
970 if let ItemKind::ExternCrate(Some(orig_name)) = item.kind {
971 if orig_name == kw::SelfLower {
976 "`#[macro_use]` is not supported on `extern crate self`",
982 |span| struct_span_err!(self.r.session, span, E0466, "bad macro import").emit();
984 Some(meta) => match meta.kind {
985 MetaItemKind::Word => {
986 import_all = Some(meta.span);
989 MetaItemKind::List(nested_metas) => {
990 for nested_meta in nested_metas {
991 match nested_meta.ident() {
992 Some(ident) if nested_meta.is_word() => {
993 single_imports.push(ident)
995 _ => ill_formed(nested_meta.span()),
999 MetaItemKind::NameValue(..) => ill_formed(meta.span),
1001 None => ill_formed(attr.span),
1006 let macro_use_import = |this: &Self, span| {
1007 this.r.arenas.alloc_import(Import {
1008 kind: ImportKind::MacroUse,
1011 parent_scope: this.parent_scope,
1012 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
1013 use_span_with_attributes: item.span_with_attributes(),
1014 has_attributes: !item.attrs.is_empty(),
1015 use_span: item.span,
1018 module_path: Vec::new(),
1019 vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
1020 used: Cell::new(false),
1024 let allow_shadowing = self.parent_scope.expansion == ExpnId::root();
1025 if let Some(span) = import_all {
1026 let import = macro_use_import(self, span);
1027 self.r.potentially_unused_imports.push(import);
1028 module.for_each_child(self, |this, ident, ns, binding| {
1030 let imported_binding = this.r.import(binding, import);
1031 this.add_macro_use_binding(ident.name, imported_binding, span, allow_shadowing);
1035 for ident in single_imports.iter().cloned() {
1036 let result = self.r.resolve_ident_in_module(
1037 ModuleOrUniformRoot::Module(module),
1044 if let Ok(binding) = result {
1045 let import = macro_use_import(self, ident.span);
1046 self.r.potentially_unused_imports.push(import);
1047 let imported_binding = self.r.import(binding, import);
1048 self.add_macro_use_binding(
1055 struct_span_err!(self.r.session, ident.span, E0469, "imported macro not found")
1060 import_all.is_some() || !single_imports.is_empty()
1063 /// Returns `true` if this attribute list contains `macro_use`.
1064 fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool {
1066 if attr.check_name(sym::macro_escape) {
1067 let msg = "`#[macro_escape]` is a deprecated synonym for `#[macro_use]`";
1068 let mut err = self.r.session.struct_span_warn(attr.span, msg);
1069 if let ast::AttrStyle::Inner = attr.style {
1070 err.help("try an outer attribute: `#[macro_use]`").emit();
1074 } else if !attr.check_name(sym::macro_use) {
1078 if !attr.is_word() {
1079 self.r.session.span_err(attr.span, "arguments to `macro_use` are not allowed here");
1087 fn visit_invoc(&mut self, id: NodeId) -> MacroRulesScope<'a> {
1088 let invoc_id = id.placeholder_to_expn_id();
1090 self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id);
1092 let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope);
1093 assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation");
1095 MacroRulesScope::Invocation(invoc_id)
1098 fn proc_macro_stub(item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
1099 if attr::contains_name(&item.attrs, sym::proc_macro) {
1100 return Some((MacroKind::Bang, item.ident, item.span));
1101 } else if attr::contains_name(&item.attrs, sym::proc_macro_attribute) {
1102 return Some((MacroKind::Attr, item.ident, item.span));
1103 } else if let Some(attr) = attr::find_by_name(&item.attrs, sym::proc_macro_derive) {
1104 if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
1105 if let Some(ident) = nested_meta.ident() {
1106 return Some((MacroKind::Derive, ident, ident.span));
1113 // Mark the given macro as unused unless its name starts with `_`.
1114 // Macro uses will remove items from this set, and the remaining
1115 // items will be reported as `unused_macros`.
1116 fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) {
1117 if !ident.as_str().starts_with('_') {
1118 self.r.unused_macros.insert(node_id, span);
1122 fn define_macro(&mut self, item: &ast::Item) -> MacroRulesScope<'a> {
1123 let parent_scope = self.parent_scope;
1124 let expansion = parent_scope.expansion;
1125 let (ext, ident, span, macro_rules) = match &item.kind {
1126 ItemKind::MacroDef(def) => {
1127 let ext = Lrc::new(self.r.compile_macro(item, self.r.session.edition()));
1128 (ext, item.ident, item.span, def.macro_rules)
1130 ItemKind::Fn(..) => match Self::proc_macro_stub(item) {
1131 Some((macro_kind, ident, span)) => {
1132 self.r.proc_macro_stubs.insert(item.id);
1133 (self.r.dummy_ext(macro_kind), ident, span, false)
1135 None => return parent_scope.macro_rules,
1137 _ => unreachable!(),
1140 let def_id = self.r.definitions.local_def_id(item.id).to_def_id();
1141 let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id);
1142 self.r.macro_map.insert(def_id, ext);
1143 self.r.local_macro_def_scopes.insert(item.id, parent_scope.module);
1146 let ident = ident.normalize_to_macros_2_0();
1147 self.r.macro_names.insert(ident);
1148 let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
1149 let vis = if is_macro_export {
1150 ty::Visibility::Public
1152 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
1154 let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas);
1155 self.r.set_binding_parent_module(binding, parent_scope.module);
1156 self.r.all_macros.insert(ident.name, res);
1157 if is_macro_export {
1158 let module = self.r.graph_root;
1159 self.r.define(module, ident, MacroNS, (res, vis, span, expansion, IsMacroExport));
1161 self.r.check_reserved_macro_name(ident, res);
1162 self.insert_unused_macro(ident, item.id, span);
1164 MacroRulesScope::Binding(self.r.arenas.alloc_macro_rules_binding(MacroRulesBinding {
1165 parent_macro_rules_scope: parent_scope.macro_rules,
1170 let module = parent_scope.module;
1171 let vis = match item.kind {
1172 // Visibilities must not be resolved non-speculatively twice
1173 // and we already resolved this one as a `fn` item visibility.
1174 ItemKind::Fn(..) => self
1175 .resolve_visibility_speculative(&item.vis, true)
1176 .unwrap_or(ty::Visibility::Public),
1177 _ => self.resolve_visibility(&item.vis),
1179 if vis != ty::Visibility::Public {
1180 self.insert_unused_macro(ident, item.id, span);
1182 self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
1183 self.parent_scope.macro_rules
1188 macro_rules! method {
1189 ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => {
1190 fn $visit(&mut self, node: &'b $ty) {
1191 if let $invoc(..) = node.kind {
1192 self.visit_invoc(node.id);
1194 visit::$walk(self, node);
1200 impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
1201 method!(visit_expr: ast::Expr, ast::ExprKind::MacCall, walk_expr);
1202 method!(visit_pat: ast::Pat, ast::PatKind::MacCall, walk_pat);
1203 method!(visit_ty: ast::Ty, ast::TyKind::MacCall, walk_ty);
1205 fn visit_item(&mut self, item: &'b Item) {
1206 let macro_use = match item.kind {
1207 ItemKind::MacroDef(..) => {
1208 self.parent_scope.macro_rules = self.define_macro(item);
1211 ItemKind::MacCall(..) => {
1212 self.parent_scope.macro_rules = self.visit_invoc(item.id);
1215 ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
1218 let orig_current_module = self.parent_scope.module;
1219 let orig_current_macro_rules_scope = self.parent_scope.macro_rules;
1220 self.build_reduced_graph_for_item(item);
1221 visit::walk_item(self, item);
1222 self.parent_scope.module = orig_current_module;
1224 self.parent_scope.macro_rules = orig_current_macro_rules_scope;
1228 fn visit_stmt(&mut self, stmt: &'b ast::Stmt) {
1229 if let ast::StmtKind::MacCall(..) = stmt.kind {
1230 self.parent_scope.macro_rules = self.visit_invoc(stmt.id);
1232 visit::walk_stmt(self, stmt);
1236 fn visit_foreign_item(&mut self, foreign_item: &'b ForeignItem) {
1237 if let ForeignItemKind::MacCall(_) = foreign_item.kind {
1238 self.visit_invoc(foreign_item.id);
1242 self.build_reduced_graph_for_foreign_item(foreign_item);
1243 visit::walk_foreign_item(self, foreign_item);
1246 fn visit_block(&mut self, block: &'b Block) {
1247 let orig_current_module = self.parent_scope.module;
1248 let orig_current_macro_rules_scope = self.parent_scope.macro_rules;
1249 self.build_reduced_graph_for_block(block);
1250 visit::walk_block(self, block);
1251 self.parent_scope.module = orig_current_module;
1252 self.parent_scope.macro_rules = orig_current_macro_rules_scope;
1255 fn visit_assoc_item(&mut self, item: &'b AssocItem, ctxt: AssocCtxt) {
1256 let parent = self.parent_scope.module;
1258 if let AssocItemKind::MacCall(_) = item.kind {
1259 self.visit_invoc(item.id);
1263 if let AssocCtxt::Impl = ctxt {
1264 self.resolve_visibility(&item.vis);
1265 visit::walk_assoc_item(self, item, ctxt);
1269 // Add the item to the trait info.
1270 let item_def_id = self.r.definitions.local_def_id(item.id).to_def_id();
1271 let (res, ns) = match item.kind {
1272 AssocItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
1273 AssocItemKind::Fn(_, ref sig, _, _) => {
1274 if sig.decl.has_self() {
1275 self.r.has_self.insert(item_def_id);
1277 (Res::Def(DefKind::AssocFn, item_def_id), ValueNS)
1279 AssocItemKind::TyAlias(..) => (Res::Def(DefKind::AssocTy, item_def_id), TypeNS),
1280 AssocItemKind::MacCall(_) => bug!(), // handled above
1283 let vis = ty::Visibility::Public;
1284 let expansion = self.parent_scope.expansion;
1285 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
1287 visit::walk_assoc_item(self, item, ctxt);
1290 fn visit_token(&mut self, t: Token) {
1291 if let token::Interpolated(nt) = t.kind {
1292 if let token::NtExpr(ref expr) = *nt {
1293 if let ast::ExprKind::MacCall(..) = expr.kind {
1294 self.visit_invoc(expr.id);
1300 fn visit_attribute(&mut self, attr: &'b ast::Attribute) {
1301 if !attr.is_doc_comment() && attr::is_builtin_attr(attr) {
1304 .push((attr.get_normal_item().path.segments[0].ident, self.parent_scope));
1306 visit::walk_attribute(self, attr);
1309 fn visit_arm(&mut self, arm: &'b ast::Arm) {
1310 if arm.is_placeholder {
1311 self.visit_invoc(arm.id);
1313 visit::walk_arm(self, arm);
1317 fn visit_field(&mut self, f: &'b ast::Field) {
1318 if f.is_placeholder {
1319 self.visit_invoc(f.id);
1321 visit::walk_field(self, f);
1325 fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
1326 if fp.is_placeholder {
1327 self.visit_invoc(fp.id);
1329 visit::walk_field_pattern(self, fp);
1333 fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
1334 if param.is_placeholder {
1335 self.visit_invoc(param.id);
1337 visit::walk_generic_param(self, param);
1341 fn visit_param(&mut self, p: &'b ast::Param) {
1342 if p.is_placeholder {
1343 self.visit_invoc(p.id);
1345 visit::walk_param(self, p);
1349 fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
1350 if sf.is_placeholder {
1351 self.visit_invoc(sf.id);
1353 self.resolve_visibility(&sf.vis);
1354 visit::walk_struct_field(self, sf);
1358 // Constructs the reduced graph for one variant. Variants exist in the
1359 // type and value namespaces.
1360 fn visit_variant(&mut self, variant: &'b ast::Variant) {
1361 if variant.is_placeholder {
1362 self.visit_invoc(variant.id);
1366 let parent = self.parent_scope.module;
1367 let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
1368 let expn_id = self.parent_scope.expansion;
1369 let ident = variant.ident;
1371 // Define a name in the type namespace.
1372 let def_id = self.r.definitions.local_def_id(variant.id).to_def_id();
1373 let res = Res::Def(DefKind::Variant, def_id);
1374 self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
1376 // If the variant is marked as non_exhaustive then lower the visibility to within the
1378 let mut ctor_vis = vis;
1379 let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
1380 if has_non_exhaustive && vis == ty::Visibility::Public {
1381 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
1384 // Define a constructor name in the value namespace.
1385 // Braced variants, unlike structs, generate unusable names in
1386 // value namespace, they are reserved for possible future use.
1387 // It's ok to use the variant's id as a ctor id since an
1388 // error will be reported on any use of such resolution anyway.
1389 let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
1390 let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id).to_def_id();
1391 let ctor_kind = CtorKind::from_ast(&variant.data);
1392 let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1393 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
1395 visit::walk_variant(self, variant);