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::macros::{LegacyBinding, LegacyScope};
9 use crate::resolve_imports::ImportDirective;
10 use crate::resolve_imports::ImportDirectiveSubclass::{self, GlobImport, SingleImport};
11 use crate::{Module, ModuleData, ModuleKind, NameBinding, NameBindingKind, Segment, ToNameBinding};
12 use crate::{ModuleOrUniformRoot, ParentScope, PerNS, Resolver, ResolverArenas, ExternPreludeEntry};
13 use crate::Namespace::{self, TypeNS, ValueNS, MacroNS};
14 use crate::{ResolutionError, Determinacy, PathResult, CrateLint};
17 use rustc::hir::def::{self, *};
18 use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
19 use rustc::hir::map::DefCollector;
21 use rustc::middle::cstore::CrateStore;
22 use rustc_metadata::cstore::LoadedMacro;
26 use rustc_data_structures::sync::Lrc;
28 use errors::Applicability;
30 use syntax::ast::{Name, Ident};
33 use syntax::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
34 use syntax::ast::{MetaItemKind, StmtKind, TraitItem, TraitItemKind};
35 use syntax::feature_gate::is_builtin_attr;
36 use syntax::token::{self, Token};
37 use syntax::print::pprust;
38 use syntax::{span_err, struct_span_err};
39 use syntax::source_map::{respan, Spanned};
40 use syntax::symbol::{kw, sym};
41 use syntax::visit::{self, Visitor};
42 use syntax_expand::base::SyntaxExtension;
43 use syntax_expand::expand::AstFragment;
44 use syntax_pos::hygiene::{MacroKind, ExpnId};
45 use syntax_pos::{Span, DUMMY_SP};
49 use rustc_error_codes::*;
51 type Res = def::Res<NodeId>;
53 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, ExpnId) {
54 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
55 arenas.alloc_name_binding(NameBinding {
56 kind: NameBindingKind::Module(self.0),
65 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId) {
66 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
67 arenas.alloc_name_binding(NameBinding {
68 kind: NameBindingKind::Res(self.0, false),
79 impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, ExpnId, IsMacroExport) {
80 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
81 arenas.alloc_name_binding(NameBinding {
82 kind: NameBindingKind::Res(self.0, true),
91 impl<'a> Resolver<'a> {
92 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
93 /// otherwise, reports an error.
94 crate fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T)
95 where T: ToNameBinding<'a>,
97 let binding = def.to_name_binding(self.arenas);
98 let key = self.new_key(ident, ns);
99 if let Err(old_binding) = self.try_define(parent, key, binding) {
100 self.report_conflict(parent, ident, ns, old_binding, &binding);
104 crate fn get_module(&mut self, def_id: DefId) -> Module<'a> {
105 if def_id.krate == LOCAL_CRATE {
106 return self.module_map[&def_id]
109 if let Some(&module) = self.extern_module_map.get(&def_id) {
113 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
114 (self.cstore().crate_name_untracked(def_id.krate), None)
116 let def_key = self.cstore().def_key(def_id);
117 (def_key.disambiguated_data.data.get_opt_name().unwrap(),
118 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })))
121 let kind = ModuleKind::Def(DefKind::Mod, def_id, name);
122 let module = self.arenas.alloc_module(ModuleData::new(
123 parent, kind, def_id, ExpnId::root(), DUMMY_SP
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)
133 .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 let mut def_collector = DefCollector::new(&mut self.definitions, parent_scope.expansion);
171 fragment.visit_with(&mut def_collector);
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> { self.r }
196 impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
197 fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
198 let parent_scope = &self.parent_scope;
200 ast::VisibilityKind::Public => ty::Visibility::Public,
201 ast::VisibilityKind::Crate(..) => {
202 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
204 ast::VisibilityKind::Inherited => {
205 ty::Visibility::Restricted(parent_scope.module.normal_ancestor_id)
207 ast::VisibilityKind::Restricted { ref path, id, .. } => {
208 // For visibilities we are not ready to provide correct implementation of "uniform
209 // paths" right now, so on 2018 edition we only allow module-relative paths for now.
210 // On 2015 edition visibilities are resolved as crate-relative by default,
211 // so we are prepending a root segment if necessary.
212 let ident = path.segments.get(0).expect("empty path in visibility").ident;
213 let crate_root = if ident.is_path_segment_keyword() {
215 } else if ident.span.rust_2018() {
216 let msg = "relative paths are not supported in visibilities on 2018 edition";
217 self.r.session.struct_span_err(ident.span, msg)
221 format!("crate::{}", pprust::path_to_string(&path)),
222 Applicability::MaybeIncorrect,
225 return ty::Visibility::Public;
227 let ctxt = ident.span.ctxt();
228 Some(Segment::from_ident(Ident::new(
229 kw::PathRoot, path.span.shrink_to_lo().with_ctxt(ctxt)
233 let segments = crate_root.into_iter()
234 .chain(path.segments.iter().map(|seg| seg.into())).collect::<Vec<_>>();
235 let expected_found_error = |this: &Self, res: Res| {
236 let path_str = Segment::names_to_string(&segments);
237 struct_span_err!(this.r.session, path.span, E0577,
238 "expected module, found {} `{}`", res.descr(), path_str)
239 .span_label(path.span, "not a module").emit();
241 match self.r.resolve_path(
247 CrateLint::SimplePath(id),
249 PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
250 let res = module.res().expect("visibility resolved to unnamed block");
251 self.r.record_partial_res(id, PartialRes::new(res));
252 if module.is_normal() {
254 ty::Visibility::Public
256 let vis = ty::Visibility::Restricted(res.def_id());
257 if self.r.is_accessible_from(vis, parent_scope.module) {
260 struct_span_err!(self.r.session, path.span, E0742,
261 "visibilities can only be restricted to ancestor modules")
263 ty::Visibility::Public
267 expected_found_error(self, res);
268 ty::Visibility::Public
271 PathResult::Module(..) => {
272 self.r.session.span_err(path.span, "visibility must resolve to a module");
273 ty::Visibility::Public
275 PathResult::NonModule(partial_res) => {
276 expected_found_error(self, partial_res.base_res());
277 ty::Visibility::Public
279 PathResult::Failed { span, label, suggestion, .. } => {
281 span, ResolutionError::FailedToResolve { label, suggestion }
283 ty::Visibility::Public
285 PathResult::Indeterminate => {
286 span_err!(self.r.session, path.span, E0578,
287 "cannot determine resolution for the visibility");
288 ty::Visibility::Public
295 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Name>>) {
296 if !field_names.is_empty() {
297 self.r.field_names.insert(def_id, field_names);
301 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
302 // If any statements are items, we need to create an anonymous module
303 block.stmts.iter().any(|statement| match statement.kind {
304 StmtKind::Item(_) | StmtKind::Mac(_) => true,
309 // Add an import directive to the current module.
310 fn add_import_directive(
312 module_path: Vec<Segment>,
313 subclass: ImportDirectiveSubclass<'a>,
321 let current_module = self.parent_scope.module;
322 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
323 parent_scope: self.parent_scope,
325 imported_module: Cell::new(None),
330 use_span_with_attributes: item.span_with_attributes(),
331 has_attributes: !item.attrs.is_empty(),
335 used: Cell::new(false),
338 debug!("add_import_directive({:?})", directive);
340 self.r.indeterminate_imports.push(directive);
341 match directive.subclass {
342 // Don't add unresolved underscore imports to modules
343 SingleImport { target: Ident { name: kw::Underscore, .. }, .. } => {}
344 SingleImport { target, type_ns_only, .. } => {
345 self.r.per_ns(|this, ns| if !type_ns_only || ns == TypeNS {
346 let key = this.new_key(target, ns);
347 let mut resolution = this.resolution(current_module, key).borrow_mut();
348 resolution.add_single_import(directive);
351 // We don't add prelude imports to the globs since they only affect lexical scopes,
352 // which are not relevant to import resolution.
353 GlobImport { is_prelude: true, .. } => {}
354 GlobImport { .. } => current_module.globs.borrow_mut().push(directive),
359 fn build_reduced_graph_for_use_tree(
361 // This particular use tree
362 use_tree: &ast::UseTree,
364 parent_prefix: &[Segment],
366 // The whole `use` item
371 debug!("build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})",
372 parent_prefix, use_tree, nested);
374 let mut prefix_iter = parent_prefix.iter().cloned()
375 .chain(use_tree.prefix.segments.iter().map(|seg| seg.into())).peekable();
377 // On 2015 edition imports are resolved as crate-relative by default,
378 // so prefixes are prepended with crate root segment if necessary.
379 // The root is prepended lazily, when the first non-empty prefix or terminating glob
380 // appears, so imports in braced groups can have roots prepended independently.
381 let is_glob = if let ast::UseTreeKind::Glob = use_tree.kind { true } else { false };
382 let crate_root = match prefix_iter.peek() {
383 Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => {
384 Some(seg.ident.span.ctxt())
386 None if is_glob && use_tree.span.rust_2015() => {
387 Some(use_tree.span.ctxt())
390 }.map(|ctxt| Segment::from_ident(Ident::new(
391 kw::PathRoot, use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt)
394 let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>();
395 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
397 let empty_for_self = |prefix: &[Segment]| {
399 prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot
401 match use_tree.kind {
402 ast::UseTreeKind::Simple(rename, ..) => {
403 let mut ident = use_tree.ident();
404 let mut module_path = prefix;
405 let mut source = module_path.pop().unwrap();
406 let mut type_ns_only = false;
409 // Correctly handle `self`
410 if source.ident.name == kw::SelfLower {
413 if empty_for_self(&module_path) {
417 SelfImportOnlyInImportListWithNonEmptyPrefix
422 // Replace `use foo::self;` with `use foo;`
423 source = module_path.pop().unwrap();
424 if rename.is_none() {
425 ident = source.ident;
430 if source.ident.name == kw::SelfLower {
432 use_tree.span, ResolutionError::SelfImportsOnlyAllowedWithin
436 // Disallow `use $crate;`
437 if source.ident.name == kw::DollarCrate && module_path.is_empty() {
438 let crate_root = self.r.resolve_crate_root(source.ident);
439 let crate_name = match crate_root.kind {
440 ModuleKind::Def(.., name) => name,
441 ModuleKind::Block(..) => unreachable!(),
443 // HACK(eddyb) unclear how good this is, but keeping `$crate`
444 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
445 // while the current crate doesn't have a valid `crate_name`.
446 if crate_name != kw::Invalid {
447 // `crate_name` should not be interpreted as relative.
448 module_path.push(Segment {
451 span: source.ident.span,
453 id: Some(self.r.next_node_id()),
455 source.ident.name = crate_name;
457 if rename.is_none() {
458 ident.name = crate_name;
461 self.r.session.struct_span_warn(item.span, "`$crate` may not be imported")
462 .note("`use $crate;` was erroneously allowed and \
463 will become a hard error in a future release")
468 if ident.name == kw::Crate {
469 self.r.session.span_err(ident.span,
470 "crate root imports need to be explicitly named: \
471 `use crate as name;`");
474 let subclass = SingleImport {
475 source: source.ident,
477 source_bindings: PerNS {
478 type_ns: Cell::new(Err(Determinacy::Undetermined)),
479 value_ns: Cell::new(Err(Determinacy::Undetermined)),
480 macro_ns: Cell::new(Err(Determinacy::Undetermined)),
482 target_bindings: PerNS {
483 type_ns: Cell::new(None),
484 value_ns: Cell::new(None),
485 macro_ns: Cell::new(None),
490 self.add_import_directive(
501 ast::UseTreeKind::Glob => {
502 let subclass = GlobImport {
503 is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
504 max_vis: Cell::new(ty::Visibility::Invisible),
506 self.add_import_directive(
517 ast::UseTreeKind::Nested(ref items) => {
518 // Ensure there is at most one `self` in the list
519 let self_spans = items.iter().filter_map(|&(ref use_tree, _)| {
520 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
521 if use_tree.ident().name == kw::SelfLower {
522 return Some(use_tree.span);
527 }).collect::<Vec<_>>();
528 if self_spans.len() > 1 {
529 let mut e = self.r.into_struct_error(
531 ResolutionError::SelfImportCanOnlyAppearOnceInTheList);
533 for other_span in self_spans.iter().skip(1) {
534 e.span_label(*other_span, "another `self` import appears here");
540 for &(ref tree, id) in items {
541 self.build_reduced_graph_for_use_tree(
542 // This particular use tree
543 tree, id, &prefix, true,
544 // The whole `use` item
545 item, vis, root_span,
549 // Empty groups `a::b::{}` are turned into synthetic `self` imports
550 // `a::b::c::{self as _}`, so that their prefixes are correctly
551 // resolved and checked for privacy/stability/etc.
552 if items.is_empty() && !empty_for_self(&prefix) {
553 let new_span = prefix[prefix.len() - 1].ident.span;
554 let tree = ast::UseTree {
555 prefix: ast::Path::from_ident(
556 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
567 &tree, id, &prefix, true,
568 // The whole `use` item
569 item, ty::Visibility::Invisible, root_span,
576 /// Constructs the reduced graph for one item.
577 fn build_reduced_graph_for_item(&mut self, item: &'b Item) {
578 let parent_scope = &self.parent_scope;
579 let parent = parent_scope.module;
580 let expansion = parent_scope.expansion;
581 let ident = item.ident;
583 let vis = self.resolve_visibility(&item.vis);
586 ItemKind::Use(ref use_tree) => {
587 self.build_reduced_graph_for_use_tree(
588 // This particular use tree
589 use_tree, item.id, &[], false,
590 // The whole `use` item
591 item, vis, use_tree.span,
595 ItemKind::ExternCrate(orig_name) => {
596 let module = if orig_name.is_none() && ident.name == kw::SelfLower {
598 .struct_span_err(item.span, "`extern crate self;` requires renaming")
602 "extern crate self as name;".into(),
603 Applicability::HasPlaceholders,
607 } else if orig_name == Some(kw::SelfLower) {
610 let crate_id = self.r.crate_loader.process_extern_crate(
611 item, &self.r.definitions
613 self.r.extern_crate_map.insert(item.id, crate_id);
614 self.r.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX })
617 let used = self.process_legacy_macro_imports(item, module);
619 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
620 let directive = self.r.arenas.alloc_import_directive(ImportDirective {
623 parent_scope: self.parent_scope,
624 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
625 subclass: ImportDirectiveSubclass::ExternCrate {
629 has_attributes: !item.attrs.is_empty(),
630 use_span_with_attributes: item.span_with_attributes(),
632 root_span: item.span,
634 module_path: Vec::new(),
636 used: Cell::new(used),
638 self.r.potentially_unused_imports.push(directive);
639 let imported_binding = self.r.import(binding, directive);
640 if ptr::eq(parent, self.r.graph_root) {
641 if let Some(entry) = self.r.extern_prelude.get(&ident.modern()) {
642 if expansion != ExpnId::root() && orig_name.is_some() &&
643 entry.extern_crate_item.is_none() {
644 let msg = "macro-expanded `extern crate` items cannot \
645 shadow names passed with `--extern`";
646 self.r.session.span_err(item.span, msg);
649 let entry = self.r.extern_prelude.entry(ident.modern())
650 .or_insert(ExternPreludeEntry {
651 extern_crate_item: None,
652 introduced_by_item: true,
654 entry.extern_crate_item = Some(imported_binding);
655 if orig_name.is_some() {
656 entry.introduced_by_item = true;
659 self.r.define(parent, ident, TypeNS, imported_binding);
662 ItemKind::GlobalAsm(..) => {}
664 ItemKind::Mod(..) if ident.name == kw::Invalid => {} // Crate root
666 ItemKind::Mod(..) => {
667 let def_id = self.r.definitions.local_def_id(item.id);
668 let module_kind = ModuleKind::Def(DefKind::Mod, def_id, ident.name);
669 let module = self.r.arenas.alloc_module(ModuleData {
670 no_implicit_prelude: parent.no_implicit_prelude || {
671 attr::contains_name(&item.attrs, sym::no_implicit_prelude)
673 ..ModuleData::new(Some(parent), module_kind, def_id, expansion, item.span)
675 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
676 self.r.module_map.insert(def_id, module);
678 // Descend into the module.
679 self.parent_scope.module = module;
682 // Handled in `rustc_metadata::{native_libs,link_args}`
683 ItemKind::ForeignMod(..) => {}
685 // These items live in the value namespace.
686 ItemKind::Static(..) => {
687 let res = Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id));
688 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
690 ItemKind::Const(..) => {
691 let res = Res::Def(DefKind::Const, self.r.definitions.local_def_id(item.id));
692 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
694 ItemKind::Fn(..) => {
695 let res = Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id));
696 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
698 // Functions introducing procedural macros reserve a slot
699 // in the macro namespace as well (see #52225).
700 self.define_macro(item);
703 // These items live in the type namespace.
704 ItemKind::TyAlias(ref ty, _) => {
705 let def_kind = match ty.kind.opaque_top_hack() {
706 None => DefKind::TyAlias,
707 Some(_) => DefKind::OpaqueTy,
709 let res = Res::Def(def_kind, self.r.definitions.local_def_id(item.id));
710 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
713 ItemKind::Enum(_, _) => {
714 let def_id = self.r.definitions.local_def_id(item.id);
715 self.r.variant_vis.insert(def_id, vis);
716 let module_kind = ModuleKind::Def(DefKind::Enum, def_id, ident.name);
717 let module = self.r.new_module(parent,
719 parent.normal_ancestor_id,
722 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
723 self.parent_scope.module = module;
726 ItemKind::TraitAlias(..) => {
727 let res = Res::Def(DefKind::TraitAlias, self.r.definitions.local_def_id(item.id));
728 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
731 // These items live in both the type and value namespaces.
732 ItemKind::Struct(ref struct_def, _) => {
733 // Define a name in the type namespace.
734 let def_id = self.r.definitions.local_def_id(item.id);
735 let res = Res::Def(DefKind::Struct, def_id);
736 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
738 let mut ctor_vis = vis;
740 let has_non_exhaustive = attr::contains_name(&item.attrs, sym::non_exhaustive);
742 // If the structure is marked as non_exhaustive then lower the visibility
743 // to within the crate.
744 if has_non_exhaustive && vis == ty::Visibility::Public {
745 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
748 // Record field names for error reporting.
749 let field_names = struct_def.fields().iter().map(|field| {
750 let field_vis = self.resolve_visibility(&field.vis);
751 if ctor_vis.is_at_least(field_vis, &*self.r) {
752 ctor_vis = field_vis;
754 respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name))
756 let item_def_id = self.r.definitions.local_def_id(item.id);
757 self.insert_field_names(item_def_id, field_names);
759 // If this is a tuple or unit struct, define a name
760 // in the value namespace as well.
761 if let Some(ctor_node_id) = struct_def.ctor_id() {
762 let ctor_res = Res::Def(
763 DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(struct_def)),
764 self.r.definitions.local_def_id(ctor_node_id),
766 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
767 self.r.struct_constructors.insert(res.def_id(), (ctor_res, ctor_vis));
771 ItemKind::Union(ref vdata, _) => {
772 let res = Res::Def(DefKind::Union, self.r.definitions.local_def_id(item.id));
773 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
775 // Record field names for error reporting.
776 let field_names = vdata.fields().iter().map(|field| {
777 self.resolve_visibility(&field.vis);
778 respan(field.span, field.ident.map_or(kw::Invalid, |ident| ident.name))
780 let item_def_id = self.r.definitions.local_def_id(item.id);
781 self.insert_field_names(item_def_id, field_names);
784 ItemKind::Impl(.., ref impl_items) => {
785 for impl_item in impl_items {
786 self.resolve_visibility(&impl_item.vis);
790 ItemKind::Trait(..) => {
791 let def_id = self.r.definitions.local_def_id(item.id);
793 // Add all the items within to a new module.
794 let module_kind = ModuleKind::Def(DefKind::Trait, def_id, ident.name);
795 let module = self.r.new_module(parent,
797 parent.normal_ancestor_id,
800 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
801 self.parent_scope.module = module;
804 ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
808 /// Constructs the reduced graph for one foreign item.
809 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) {
810 let (res, ns) = match item.kind {
811 ForeignItemKind::Fn(..) => {
812 (Res::Def(DefKind::Fn, self.r.definitions.local_def_id(item.id)), ValueNS)
814 ForeignItemKind::Static(..) => {
815 (Res::Def(DefKind::Static, self.r.definitions.local_def_id(item.id)), ValueNS)
817 ForeignItemKind::Ty => {
818 (Res::Def(DefKind::ForeignTy, self.r.definitions.local_def_id(item.id)), TypeNS)
820 ForeignItemKind::Macro(_) => unreachable!(),
822 let parent = self.parent_scope.module;
823 let expansion = self.parent_scope.expansion;
824 let vis = self.resolve_visibility(&item.vis);
825 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
828 fn build_reduced_graph_for_block(&mut self, block: &Block) {
829 let parent = self.parent_scope.module;
830 let expansion = self.parent_scope.expansion;
831 if self.block_needs_anonymous_module(block) {
832 let module = self.r.new_module(parent,
833 ModuleKind::Block(block.id),
834 parent.normal_ancestor_id,
837 self.r.block_map.insert(block.id, module);
838 self.parent_scope.module = module; // Descend into the block.
842 /// Builds the reduced graph for a single item in an external crate.
843 fn build_reduced_graph_for_external_crate_res(&mut self, child: Export<NodeId>) {
844 let parent = self.parent_scope.module;
845 let Export { ident, res, vis, span } = child;
846 let expansion = ExpnId::root(); // FIXME(jseyfried) intercrate hygiene
847 // Record primary definitions.
849 Res::Def(kind @ DefKind::Mod, def_id)
850 | Res::Def(kind @ DefKind::Enum, def_id)
851 | Res::Def(kind @ DefKind::Trait, def_id) => {
852 let module = self.r.new_module(
854 ModuleKind::Def(kind, def_id, ident.name),
859 self.r.define(parent, ident, TypeNS, (module, vis, span, expansion));
861 Res::Def(DefKind::Struct, _)
862 | Res::Def(DefKind::Union, _)
863 | Res::Def(DefKind::Variant, _)
864 | Res::Def(DefKind::TyAlias, _)
865 | Res::Def(DefKind::ForeignTy, _)
866 | Res::Def(DefKind::OpaqueTy, _)
867 | Res::Def(DefKind::TraitAlias, _)
868 | Res::Def(DefKind::AssocTy, _)
869 | Res::Def(DefKind::AssocOpaqueTy, _)
872 self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)),
873 Res::Def(DefKind::Fn, _)
874 | Res::Def(DefKind::Method, _)
875 | Res::Def(DefKind::Static, _)
876 | Res::Def(DefKind::Const, _)
877 | Res::Def(DefKind::AssocConst, _)
878 | Res::Def(DefKind::Ctor(..), _) =>
879 self.r.define(parent, ident, ValueNS, (res, vis, span, expansion)),
880 Res::Def(DefKind::Macro(..), _)
881 | Res::NonMacroAttr(..) =>
882 self.r.define(parent, ident, MacroNS, (res, vis, span, expansion)),
883 Res::Def(DefKind::TyParam, _) | Res::Def(DefKind::ConstParam, _)
884 | Res::Local(..) | Res::SelfTy(..) | Res::SelfCtor(..) | Res::Err =>
885 bug!("unexpected resolution: {:?}", res)
887 // Record some extra data for better diagnostics.
888 let cstore = self.r.cstore();
890 Res::Def(DefKind::Struct, def_id) | Res::Def(DefKind::Union, def_id) => {
891 let field_names = cstore.struct_field_names_untracked(def_id, self.r.session);
892 self.insert_field_names(def_id, field_names);
894 Res::Def(DefKind::Method, def_id) => {
895 if cstore.associated_item_cloned_untracked(def_id).method_has_self_argument {
896 self.r.has_self.insert(def_id);
899 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), def_id) => {
900 let parent = cstore.def_key(def_id).parent;
901 if let Some(struct_def_id) = parent.map(|index| DefId { index, ..def_id }) {
902 self.r.struct_constructors.insert(struct_def_id, (res, vis));
909 fn legacy_import_macro(&mut self,
911 binding: &'a NameBinding<'a>,
913 allow_shadowing: bool) {
914 if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
915 let msg = format!("`{}` is already in scope", name);
917 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
918 self.r.session.struct_span_err(span, &msg).note(note).emit();
922 /// Returns `true` if we should consider the underlying `extern crate` to be used.
923 fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>) -> bool {
924 let mut import_all = None;
925 let mut single_imports = Vec::new();
926 for attr in &item.attrs {
927 if attr.check_name(sym::macro_use) {
928 if self.parent_scope.module.parent.is_some() {
929 span_err!(self.r.session, item.span, E0468,
930 "an `extern crate` loading macros must be at the crate root");
932 if let ItemKind::ExternCrate(Some(orig_name)) = item.kind {
933 if orig_name == kw::SelfLower {
934 self.r.session.span_err(attr.span,
935 "`macro_use` is not supported on `extern crate self`");
938 let ill_formed = |span| span_err!(self.r.session, span, E0466, "bad macro import");
940 Some(meta) => match meta.kind {
941 MetaItemKind::Word => {
942 import_all = Some(meta.span);
945 MetaItemKind::List(nested_metas) => for nested_meta in nested_metas {
946 match nested_meta.ident() {
947 Some(ident) if nested_meta.is_word() => single_imports.push(ident),
948 _ => ill_formed(nested_meta.span()),
951 MetaItemKind::NameValue(..) => ill_formed(meta.span),
953 None => ill_formed(attr.span),
958 let macro_use_directive =
959 |this: &Self, span| this.r.arenas.alloc_import_directive(ImportDirective {
962 parent_scope: this.parent_scope,
963 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
964 subclass: ImportDirectiveSubclass::MacroUse,
965 use_span_with_attributes: item.span_with_attributes(),
966 has_attributes: !item.attrs.is_empty(),
970 module_path: Vec::new(),
971 vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
972 used: Cell::new(false),
975 let allow_shadowing = self.parent_scope.expansion == ExpnId::root();
976 if let Some(span) = import_all {
977 let directive = macro_use_directive(self, span);
978 self.r.potentially_unused_imports.push(directive);
979 module.for_each_child(self, |this, ident, ns, binding| if ns == MacroNS {
980 let imported_binding = this.r.import(binding, directive);
981 this.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
984 for ident in single_imports.iter().cloned() {
985 let result = self.r.resolve_ident_in_module(
986 ModuleOrUniformRoot::Module(module),
993 if let Ok(binding) = result {
994 let directive = macro_use_directive(self, ident.span);
995 self.r.potentially_unused_imports.push(directive);
996 let imported_binding = self.r.import(binding, directive);
997 self.legacy_import_macro(ident.name, imported_binding,
998 ident.span, allow_shadowing);
1000 span_err!(self.r.session, ident.span, E0469, "imported macro not found");
1004 import_all.is_some() || !single_imports.is_empty()
1007 /// Returns `true` if this attribute list contains `macro_use`.
1008 fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool {
1010 if attr.check_name(sym::macro_escape) {
1011 let msg = "macro_escape is a deprecated synonym for macro_use";
1012 let mut err = self.r.session.struct_span_warn(attr.span, msg);
1013 if let ast::AttrStyle::Inner = attr.style {
1014 err.help("consider an outer attribute, `#[macro_use]` mod ...").emit();
1018 } else if !attr.check_name(sym::macro_use) {
1022 if !attr.is_word() {
1023 self.r.session.span_err(attr.span, "arguments to macro_use are not allowed here");
1031 fn visit_invoc(&mut self, id: NodeId) -> LegacyScope<'a> {
1032 let invoc_id = id.placeholder_to_expn_id();
1034 self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id);
1036 let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope);
1037 assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation");
1039 LegacyScope::Invocation(invoc_id)
1042 fn proc_macro_stub(item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
1043 if attr::contains_name(&item.attrs, sym::proc_macro) {
1044 return Some((MacroKind::Bang, item.ident, item.span));
1045 } else if attr::contains_name(&item.attrs, sym::proc_macro_attribute) {
1046 return Some((MacroKind::Attr, item.ident, item.span));
1047 } else if let Some(attr) = attr::find_by_name(&item.attrs, sym::proc_macro_derive) {
1048 if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
1049 if let Some(ident) = nested_meta.ident() {
1050 return Some((MacroKind::Derive, ident, ident.span));
1057 // Mark the given macro as unused unless its name starts with `_`.
1058 // Macro uses will remove items from this set, and the remaining
1059 // items will be reported as `unused_macros`.
1060 fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) {
1061 if !ident.as_str().starts_with("_") {
1062 self.r.unused_macros.insert(node_id, span);
1066 fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> {
1067 let parent_scope = self.parent_scope;
1068 let expansion = parent_scope.expansion;
1069 let (ext, ident, span, is_legacy) = match &item.kind {
1070 ItemKind::MacroDef(def) => {
1071 let ext = Lrc::new(self.r.compile_macro(item, self.r.session.edition()));
1072 (ext, item.ident, item.span, def.legacy)
1074 ItemKind::Fn(..) => match Self::proc_macro_stub(item) {
1075 Some((macro_kind, ident, span)) => {
1076 self.r.proc_macro_stubs.insert(item.id);
1077 (self.r.dummy_ext(macro_kind), ident, span, false)
1079 None => return parent_scope.legacy,
1081 _ => unreachable!(),
1084 let def_id = self.r.definitions.local_def_id(item.id);
1085 let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id);
1086 self.r.macro_map.insert(def_id, ext);
1087 self.r.local_macro_def_scopes.insert(item.id, parent_scope.module);
1090 let ident = ident.modern();
1091 self.r.macro_names.insert(ident);
1092 let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
1093 let vis = if is_macro_export {
1094 ty::Visibility::Public
1096 ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
1098 let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas);
1099 self.r.set_binding_parent_module(binding, parent_scope.module);
1100 self.r.all_macros.insert(ident.name, res);
1101 if is_macro_export {
1102 let module = self.r.graph_root;
1103 self.r.define(module, ident, MacroNS,
1104 (res, vis, span, expansion, IsMacroExport));
1106 self.r.check_reserved_macro_name(ident, res);
1107 self.insert_unused_macro(ident, item.id, span);
1109 LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding {
1110 parent_legacy_scope: parent_scope.legacy, binding, ident
1113 let module = parent_scope.module;
1114 let vis = self.resolve_visibility(&item.vis);
1115 if vis != ty::Visibility::Public {
1116 self.insert_unused_macro(ident, item.id, span);
1118 self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
1119 self.parent_scope.legacy
1124 macro_rules! method {
1125 ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => {
1126 fn $visit(&mut self, node: &'b $ty) {
1127 if let $invoc(..) = node.kind {
1128 self.visit_invoc(node.id);
1130 visit::$walk(self, node);
1136 impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
1137 method!(visit_impl_item: ast::ImplItem, ast::ImplItemKind::Macro, walk_impl_item);
1138 method!(visit_expr: ast::Expr, ast::ExprKind::Mac, walk_expr);
1139 method!(visit_pat: ast::Pat, ast::PatKind::Mac, walk_pat);
1140 method!(visit_ty: ast::Ty, ast::TyKind::Mac, walk_ty);
1142 fn visit_item(&mut self, item: &'b Item) {
1143 let macro_use = match item.kind {
1144 ItemKind::MacroDef(..) => {
1145 self.parent_scope.legacy = self.define_macro(item);
1148 ItemKind::Mac(..) => {
1149 self.parent_scope.legacy = self.visit_invoc(item.id);
1152 ItemKind::Mod(..) => self.contains_macro_use(&item.attrs),
1155 let orig_current_module = self.parent_scope.module;
1156 let orig_current_legacy_scope = self.parent_scope.legacy;
1157 self.build_reduced_graph_for_item(item);
1158 visit::walk_item(self, item);
1159 self.parent_scope.module = orig_current_module;
1161 self.parent_scope.legacy = orig_current_legacy_scope;
1165 fn visit_stmt(&mut self, stmt: &'b ast::Stmt) {
1166 if let ast::StmtKind::Mac(..) = stmt.kind {
1167 self.parent_scope.legacy = self.visit_invoc(stmt.id);
1169 visit::walk_stmt(self, stmt);
1173 fn visit_foreign_item(&mut self, foreign_item: &'b ForeignItem) {
1174 if let ForeignItemKind::Macro(_) = foreign_item.kind {
1175 self.visit_invoc(foreign_item.id);
1179 self.build_reduced_graph_for_foreign_item(foreign_item);
1180 visit::walk_foreign_item(self, foreign_item);
1183 fn visit_block(&mut self, block: &'b Block) {
1184 let orig_current_module = self.parent_scope.module;
1185 let orig_current_legacy_scope = self.parent_scope.legacy;
1186 self.build_reduced_graph_for_block(block);
1187 visit::walk_block(self, block);
1188 self.parent_scope.module = orig_current_module;
1189 self.parent_scope.legacy = orig_current_legacy_scope;
1192 fn visit_trait_item(&mut self, item: &'b TraitItem) {
1193 let parent = self.parent_scope.module;
1195 if let TraitItemKind::Macro(_) = item.kind {
1196 self.visit_invoc(item.id);
1200 // Add the item to the trait info.
1201 let item_def_id = self.r.definitions.local_def_id(item.id);
1202 let (res, ns) = match item.kind {
1203 TraitItemKind::Const(..) => (Res::Def(DefKind::AssocConst, item_def_id), ValueNS),
1204 TraitItemKind::Method(ref sig, _) => {
1205 if sig.decl.has_self() {
1206 self.r.has_self.insert(item_def_id);
1208 (Res::Def(DefKind::Method, item_def_id), ValueNS)
1210 TraitItemKind::Type(..) => (Res::Def(DefKind::AssocTy, item_def_id), TypeNS),
1211 TraitItemKind::Macro(_) => bug!(), // handled above
1214 let vis = ty::Visibility::Public;
1215 let expansion = self.parent_scope.expansion;
1216 self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion));
1218 visit::walk_trait_item(self, item);
1221 fn visit_token(&mut self, t: Token) {
1222 if let token::Interpolated(nt) = t.kind {
1223 if let token::NtExpr(ref expr) = *nt {
1224 if let ast::ExprKind::Mac(..) = expr.kind {
1225 self.visit_invoc(expr.id);
1231 fn visit_attribute(&mut self, attr: &'b ast::Attribute) {
1232 if !attr.is_doc_comment() && is_builtin_attr(attr) {
1233 self.r.builtin_attrs.push(
1234 (attr.get_normal_item().path.segments[0].ident, self.parent_scope)
1237 visit::walk_attribute(self, attr);
1240 fn visit_arm(&mut self, arm: &'b ast::Arm) {
1241 if arm.is_placeholder {
1242 self.visit_invoc(arm.id);
1244 visit::walk_arm(self, arm);
1248 fn visit_field(&mut self, f: &'b ast::Field) {
1249 if f.is_placeholder {
1250 self.visit_invoc(f.id);
1252 visit::walk_field(self, f);
1256 fn visit_field_pattern(&mut self, fp: &'b ast::FieldPat) {
1257 if fp.is_placeholder {
1258 self.visit_invoc(fp.id);
1260 visit::walk_field_pattern(self, fp);
1264 fn visit_generic_param(&mut self, param: &'b ast::GenericParam) {
1265 if param.is_placeholder {
1266 self.visit_invoc(param.id);
1268 visit::walk_generic_param(self, param);
1272 fn visit_param(&mut self, p: &'b ast::Param) {
1273 if p.is_placeholder {
1274 self.visit_invoc(p.id);
1276 visit::walk_param(self, p);
1280 fn visit_struct_field(&mut self, sf: &'b ast::StructField) {
1281 if sf.is_placeholder {
1282 self.visit_invoc(sf.id);
1284 visit::walk_struct_field(self, sf);
1288 // Constructs the reduced graph for one variant. Variants exist in the
1289 // type and value namespaces.
1290 fn visit_variant(&mut self, variant: &'b ast::Variant) {
1291 if variant.is_placeholder {
1292 self.visit_invoc(variant.id);
1296 let parent = self.parent_scope.module;
1297 let vis = self.r.variant_vis[&parent.def_id().expect("enum without def-id")];
1298 let expn_id = self.parent_scope.expansion;
1299 let ident = variant.ident;
1301 // Define a name in the type namespace.
1302 let def_id = self.r.definitions.local_def_id(variant.id);
1303 let res = Res::Def(DefKind::Variant, def_id);
1304 self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id));
1306 // If the variant is marked as non_exhaustive then lower the visibility to within the
1308 let mut ctor_vis = vis;
1309 let has_non_exhaustive = attr::contains_name(&variant.attrs, sym::non_exhaustive);
1310 if has_non_exhaustive && vis == ty::Visibility::Public {
1311 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
1314 // Define a constructor name in the value namespace.
1315 // Braced variants, unlike structs, generate unusable names in
1316 // value namespace, they are reserved for possible future use.
1317 // It's ok to use the variant's id as a ctor id since an
1318 // error will be reported on any use of such resolution anyway.
1319 let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id);
1320 let ctor_def_id = self.r.definitions.local_def_id(ctor_node_id);
1321 let ctor_kind = CtorKind::from_ast(&variant.data);
1322 let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id);
1323 self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id));
1325 visit::walk_variant(self, variant);