diff options
Diffstat (limited to 'compiler/rustc_resolve/src/build_reduced_graph.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/build_reduced_graph.rs | 1546 |
1 files changed, 1546 insertions, 0 deletions
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs new file mode 100644 index 000000000..e955a1798 --- /dev/null +++ b/compiler/rustc_resolve/src/build_reduced_graph.rs @@ -0,0 +1,1546 @@ +//! After we obtain a fresh AST fragment from a macro, code in this module helps to integrate +//! that fragment into the module structures that are already partially built. +//! +//! Items from the fragment are placed into modules, +//! unexpanded macros in the fragment are visited and registered. +//! Imports are also considered items and placed into modules here, but not resolved yet. + +use crate::def_collector::collect_definitions; +use crate::imports::{Import, ImportKind}; +use crate::macros::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef}; +use crate::Namespace::{self, MacroNS, TypeNS, ValueNS}; +use crate::{Determinacy, ExternPreludeEntry, Finalize, Module, ModuleKind, ModuleOrUniformRoot}; +use crate::{ + MacroData, NameBinding, NameBindingKind, ParentScope, PathResult, PerNS, ResolutionError, +}; +use crate::{Resolver, ResolverArenas, Segment, ToNameBinding, VisResolutionError}; + +use rustc_ast::visit::{self, AssocCtxt, Visitor}; +use rustc_ast::{self as ast, AssocItem, AssocItemKind, MetaItemKind, StmtKind}; +use rustc_ast::{Block, Fn, ForeignItem, ForeignItemKind, Impl, Item, ItemKind, NodeId}; +use rustc_attr as attr; +use rustc_data_structures::sync::Lrc; +use rustc_errors::{struct_span_err, Applicability}; +use rustc_expand::expand::AstFragment; +use rustc_hir::def::{self, *}; +use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID}; +use rustc_metadata::creader::LoadedMacro; +use rustc_middle::bug; +use rustc_middle::metadata::ModChild; +use rustc_middle::ty::{self, DefIdTree}; +use rustc_session::cstore::CrateStore; +use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind}; +use rustc_span::source_map::{respan, Spanned}; +use rustc_span::symbol::{kw, sym, Ident, Symbol}; +use rustc_span::Span; + +use std::cell::Cell; +use std::ptr; +use tracing::debug; + +type Res = def::Res<NodeId>; + +impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, LocalExpnId) { + fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> { + arenas.alloc_name_binding(NameBinding { + kind: NameBindingKind::Module(self.0), + ambiguity: None, + vis: self.1, + span: self.2, + expansion: self.3, + }) + } +} + +impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, LocalExpnId) { + fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> { + arenas.alloc_name_binding(NameBinding { + kind: NameBindingKind::Res(self.0, false), + ambiguity: None, + vis: self.1, + span: self.2, + expansion: self.3, + }) + } +} + +struct IsMacroExport; + +impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, LocalExpnId, IsMacroExport) { + fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> { + arenas.alloc_name_binding(NameBinding { + kind: NameBindingKind::Res(self.0, true), + ambiguity: None, + vis: self.1, + span: self.2, + expansion: self.3, + }) + } +} + +impl<'a> Resolver<'a> { + /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined; + /// otherwise, reports an error. + pub(crate) fn define<T>(&mut self, parent: Module<'a>, ident: Ident, ns: Namespace, def: T) + where + T: ToNameBinding<'a>, + { + let binding = def.to_name_binding(self.arenas); + let key = self.new_key(ident, ns); + if let Err(old_binding) = self.try_define(parent, key, binding) { + self.report_conflict(parent, ident, ns, old_binding, &binding); + } + } + + /// Walks up the tree of definitions starting at `def_id`, + /// stopping at the first encountered module. + /// Parent block modules for arbitrary def-ids are not recorded for the local crate, + /// and are not preserved in metadata for foreign crates, so block modules are never + /// returned by this function. + /// + /// For the local crate ignoring block modules may be incorrect, so use this method with care. + /// + /// For foreign crates block modules can be ignored without introducing observable differences, + /// moreover they has to be ignored right now because they are not kept in metadata. + /// Foreign parent modules are used for resolving names used by foreign macros with def-site + /// hygiene, therefore block module ignorability relies on macros with def-site hygiene and + /// block module parents being unreachable from other crates. + /// Reachable macros with block module parents exist due to `#[macro_export] macro_rules!`, + /// but they cannot use def-site hygiene, so the assumption holds + /// (<https://github.com/rust-lang/rust/pull/77984#issuecomment-712445508>). + pub fn get_nearest_non_block_module(&mut self, mut def_id: DefId) -> Module<'a> { + loop { + match self.get_module(def_id) { + Some(module) => return module, + None => def_id = self.parent(def_id), + } + } + } + + pub fn expect_module(&mut self, def_id: DefId) -> Module<'a> { + self.get_module(def_id).expect("argument `DefId` is not a module") + } + + /// If `def_id` refers to a module (in resolver's sense, i.e. a module item, crate root, enum, + /// or trait), then this function returns that module's resolver representation, otherwise it + /// returns `None`. + pub(crate) fn get_module(&mut self, def_id: DefId) -> Option<Module<'a>> { + if let module @ Some(..) = self.module_map.get(&def_id) { + return module.copied(); + } + + if !def_id.is_local() { + let def_kind = self.cstore().def_kind(def_id); + match def_kind { + DefKind::Mod | DefKind::Enum | DefKind::Trait => { + let def_key = self.cstore().def_key(def_id); + let parent = def_key.parent.map(|index| { + self.get_nearest_non_block_module(DefId { index, krate: def_id.krate }) + }); + let name = if let Some(cnum) = def_id.as_crate_root() { + self.cstore().crate_name(cnum) + } else { + def_key.disambiguated_data.data.get_opt_name().expect("module without name") + }; + + Some(self.new_module( + parent, + ModuleKind::Def(def_kind, def_id, name), + self.cstore().module_expansion_untracked(def_id, &self.session), + self.cstore().get_span_untracked(def_id, &self.session), + // FIXME: Account for `#[no_implicit_prelude]` attributes. + parent.map_or(false, |module| module.no_implicit_prelude), + )) + } + _ => None, + } + } else { + None + } + } + + pub(crate) fn expn_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> { + match expn_id.expn_data().macro_def_id { + Some(def_id) => self.macro_def_scope(def_id), + None => expn_id + .as_local() + .and_then(|expn_id| self.ast_transform_scopes.get(&expn_id)) + .unwrap_or(&self.graph_root), + } + } + + pub(crate) fn macro_def_scope(&mut self, def_id: DefId) -> Module<'a> { + if let Some(id) = def_id.as_local() { + self.local_macro_def_scopes[&id] + } else { + self.get_nearest_non_block_module(def_id) + } + } + + pub(crate) fn get_macro(&mut self, res: Res) -> Option<MacroData> { + match res { + Res::Def(DefKind::Macro(..), def_id) => Some(self.get_macro_by_def_id(def_id)), + Res::NonMacroAttr(_) => { + Some(MacroData { ext: self.non_macro_attr.clone(), macro_rules: false }) + } + _ => None, + } + } + + pub(crate) fn get_macro_by_def_id(&mut self, def_id: DefId) -> MacroData { + if let Some(macro_data) = self.macro_map.get(&def_id) { + return macro_data.clone(); + } + + let (ext, macro_rules) = match self.cstore().load_macro_untracked(def_id, &self.session) { + LoadedMacro::MacroDef(item, edition) => ( + Lrc::new(self.compile_macro(&item, edition).0), + matches!(item.kind, ItemKind::MacroDef(def) if def.macro_rules), + ), + LoadedMacro::ProcMacro(extz) => (Lrc::new(extz), false), + }; + + let macro_data = MacroData { ext, macro_rules }; + self.macro_map.insert(def_id, macro_data.clone()); + macro_data + } + + pub(crate) fn build_reduced_graph( + &mut self, + fragment: &AstFragment, + parent_scope: ParentScope<'a>, + ) -> MacroRulesScopeRef<'a> { + collect_definitions(self, fragment, parent_scope.expansion); + let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope }; + fragment.visit_with(&mut visitor); + visitor.parent_scope.macro_rules + } + + pub(crate) fn build_reduced_graph_external(&mut self, module: Module<'a>) { + for child in self.cstore().module_children_untracked(module.def_id(), self.session) { + let parent_scope = ParentScope::module(module, self); + BuildReducedGraphVisitor { r: self, parent_scope } + .build_reduced_graph_for_external_crate_res(child); + } + } +} + +struct BuildReducedGraphVisitor<'a, 'b> { + r: &'b mut Resolver<'a>, + parent_scope: ParentScope<'a>, +} + +impl<'a> AsMut<Resolver<'a>> for BuildReducedGraphVisitor<'a, '_> { + fn as_mut(&mut self) -> &mut Resolver<'a> { + self.r + } +} + +impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { + fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility { + self.try_resolve_visibility(vis, true).unwrap_or_else(|err| { + self.r.report_vis_error(err); + ty::Visibility::Public + }) + } + + fn try_resolve_visibility<'ast>( + &mut self, + vis: &'ast ast::Visibility, + finalize: bool, + ) -> Result<ty::Visibility, VisResolutionError<'ast>> { + let parent_scope = &self.parent_scope; + match vis.kind { + ast::VisibilityKind::Public => Ok(ty::Visibility::Public), + ast::VisibilityKind::Inherited => { + Ok(match self.parent_scope.module.kind { + // Any inherited visibility resolved directly inside an enum or trait + // (i.e. variants, fields, and trait items) inherits from the visibility + // of the enum or trait. + ModuleKind::Def(DefKind::Enum | DefKind::Trait, def_id, _) => { + self.r.visibilities[&def_id.expect_local()] + } + // Otherwise, the visibility is restricted to the nearest parent `mod` item. + _ => ty::Visibility::Restricted(self.parent_scope.module.nearest_parent_mod()), + }) + } + ast::VisibilityKind::Restricted { ref path, id, .. } => { + // Make `PRIVATE_IN_PUBLIC` lint a hard error. + self.r.has_pub_restricted = true; + // For visibilities we are not ready to provide correct implementation of "uniform + // paths" right now, so on 2018 edition we only allow module-relative paths for now. + // On 2015 edition visibilities are resolved as crate-relative by default, + // so we are prepending a root segment if necessary. + let ident = path.segments.get(0).expect("empty path in visibility").ident; + let crate_root = if ident.is_path_segment_keyword() { + None + } else if ident.span.rust_2015() { + Some(Segment::from_ident(Ident::new( + kw::PathRoot, + path.span.shrink_to_lo().with_ctxt(ident.span.ctxt()), + ))) + } else { + return Err(VisResolutionError::Relative2018(ident.span, path)); + }; + + let segments = crate_root + .into_iter() + .chain(path.segments.iter().map(|seg| seg.into())) + .collect::<Vec<_>>(); + let expected_found_error = |res| { + Err(VisResolutionError::ExpectedFound( + path.span, + Segment::names_to_string(&segments), + res, + )) + }; + match self.r.resolve_path( + &segments, + Some(TypeNS), + parent_scope, + finalize.then(|| Finalize::new(id, path.span)), + None, + ) { + PathResult::Module(ModuleOrUniformRoot::Module(module)) => { + let res = module.res().expect("visibility resolved to unnamed block"); + if finalize { + self.r.record_partial_res(id, PartialRes::new(res)); + } + if module.is_normal() { + if res == Res::Err { + Ok(ty::Visibility::Public) + } else { + let vis = ty::Visibility::Restricted(res.def_id()); + if self.r.is_accessible_from(vis, parent_scope.module) { + Ok(vis) + } else { + Err(VisResolutionError::AncestorOnly(path.span)) + } + } + } else { + expected_found_error(res) + } + } + PathResult::Module(..) => Err(VisResolutionError::ModuleOnly(path.span)), + PathResult::NonModule(partial_res) => { + expected_found_error(partial_res.base_res()) + } + PathResult::Failed { span, label, suggestion, .. } => { + Err(VisResolutionError::FailedToResolve(span, label, suggestion)) + } + PathResult::Indeterminate => Err(VisResolutionError::Indeterminate(path.span)), + } + } + } + } + + fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) { + let field_names = vdata + .fields() + .iter() + .map(|field| respan(field.span, field.ident.map_or(kw::Empty, |ident| ident.name))) + .collect(); + self.insert_field_names(def_id, field_names); + } + + fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Spanned<Symbol>>) { + self.r.field_names.insert(def_id, field_names); + } + + fn block_needs_anonymous_module(&mut self, block: &Block) -> bool { + // If any statements are items, we need to create an anonymous module + block + .stmts + .iter() + .any(|statement| matches!(statement.kind, StmtKind::Item(_) | StmtKind::MacCall(_))) + } + + // Add an import to the current module. + fn add_import( + &mut self, + module_path: Vec<Segment>, + kind: ImportKind<'a>, + span: Span, + id: NodeId, + item: &ast::Item, + root_span: Span, + root_id: NodeId, + vis: ty::Visibility, + ) { + let current_module = self.parent_scope.module; + let import = self.r.arenas.alloc_import(Import { + kind, + parent_scope: self.parent_scope, + module_path, + imported_module: Cell::new(None), + span, + id, + use_span: item.span, + use_span_with_attributes: item.span_with_attributes(), + has_attributes: !item.attrs.is_empty(), + root_span, + root_id, + vis: Cell::new(vis), + used: Cell::new(false), + }); + + self.r.indeterminate_imports.push(import); + match import.kind { + // Don't add unresolved underscore imports to modules + ImportKind::Single { target: Ident { name: kw::Underscore, .. }, .. } => {} + ImportKind::Single { target, type_ns_only, .. } => { + self.r.per_ns(|this, ns| { + if !type_ns_only || ns == TypeNS { + let key = this.new_key(target, ns); + let mut resolution = this.resolution(current_module, key).borrow_mut(); + resolution.add_single_import(import); + } + }); + } + // We don't add prelude imports to the globs since they only affect lexical scopes, + // which are not relevant to import resolution. + ImportKind::Glob { is_prelude: true, .. } => {} + ImportKind::Glob { .. } => current_module.globs.borrow_mut().push(import), + _ => unreachable!(), + } + } + + fn build_reduced_graph_for_use_tree( + &mut self, + // This particular use tree + use_tree: &ast::UseTree, + id: NodeId, + parent_prefix: &[Segment], + nested: bool, + // The whole `use` item + item: &Item, + vis: ty::Visibility, + root_span: Span, + ) { + debug!( + "build_reduced_graph_for_use_tree(parent_prefix={:?}, use_tree={:?}, nested={})", + parent_prefix, use_tree, nested + ); + + let mut prefix_iter = parent_prefix + .iter() + .cloned() + .chain(use_tree.prefix.segments.iter().map(|seg| seg.into())) + .peekable(); + + // On 2015 edition imports are resolved as crate-relative by default, + // so prefixes are prepended with crate root segment if necessary. + // The root is prepended lazily, when the first non-empty prefix or terminating glob + // appears, so imports in braced groups can have roots prepended independently. + let is_glob = matches!(use_tree.kind, ast::UseTreeKind::Glob); + let crate_root = match prefix_iter.peek() { + Some(seg) if !seg.ident.is_path_segment_keyword() && seg.ident.span.rust_2015() => { + Some(seg.ident.span.ctxt()) + } + None if is_glob && use_tree.span.rust_2015() => Some(use_tree.span.ctxt()), + _ => None, + } + .map(|ctxt| { + Segment::from_ident(Ident::new( + kw::PathRoot, + use_tree.prefix.span.shrink_to_lo().with_ctxt(ctxt), + )) + }); + + let prefix = crate_root.into_iter().chain(prefix_iter).collect::<Vec<_>>(); + debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix); + + let empty_for_self = |prefix: &[Segment]| { + prefix.is_empty() || prefix.len() == 1 && prefix[0].ident.name == kw::PathRoot + }; + match use_tree.kind { + ast::UseTreeKind::Simple(rename, id1, id2) => { + let mut ident = use_tree.ident(); + let mut module_path = prefix; + let mut source = module_path.pop().unwrap(); + let mut type_ns_only = false; + + self.r.visibilities.insert(self.r.local_def_id(id), vis); + if id1 != ast::DUMMY_NODE_ID { + self.r.visibilities.insert(self.r.local_def_id(id1), vis); + } + if id2 != ast::DUMMY_NODE_ID { + self.r.visibilities.insert(self.r.local_def_id(id2), vis); + } + + if nested { + // Correctly handle `self` + if source.ident.name == kw::SelfLower { + type_ns_only = true; + + if empty_for_self(&module_path) { + self.r.report_error( + use_tree.span, + ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix, + ); + return; + } + + // Replace `use foo::{ self };` with `use foo;` + source = module_path.pop().unwrap(); + if rename.is_none() { + ident = source.ident; + } + } + } else { + // Disallow `self` + if source.ident.name == kw::SelfLower { + let parent = module_path.last(); + + let span = match parent { + // only `::self` from `use foo::self as bar` + Some(seg) => seg.ident.span.shrink_to_hi().to(source.ident.span), + None => source.ident.span, + }; + let span_with_rename = match rename { + // only `self as bar` from `use foo::self as bar` + Some(rename) => source.ident.span.to(rename.span), + None => source.ident.span, + }; + self.r.report_error( + span, + ResolutionError::SelfImportsOnlyAllowedWithin { + root: parent.is_none(), + span_with_rename, + }, + ); + + // Error recovery: replace `use foo::self;` with `use foo;` + if let Some(parent) = module_path.pop() { + source = parent; + if rename.is_none() { + ident = source.ident; + } + } + } + + // Disallow `use $crate;` + if source.ident.name == kw::DollarCrate && module_path.is_empty() { + let crate_root = self.r.resolve_crate_root(source.ident); + let crate_name = match crate_root.kind { + ModuleKind::Def(.., name) => name, + ModuleKind::Block => unreachable!(), + }; + // HACK(eddyb) unclear how good this is, but keeping `$crate` + // in `source` breaks `src/test/ui/imports/import-crate-var.rs`, + // while the current crate doesn't have a valid `crate_name`. + if crate_name != kw::Empty { + // `crate_name` should not be interpreted as relative. + module_path.push(Segment::from_ident_and_id( + Ident { name: kw::PathRoot, span: source.ident.span }, + self.r.next_node_id(), + )); + source.ident.name = crate_name; + } + if rename.is_none() { + ident.name = crate_name; + } + + self.r + .session + .struct_span_err(item.span, "`$crate` may not be imported") + .emit(); + } + } + + if ident.name == kw::Crate { + self.r.session.span_err( + ident.span, + "crate root imports need to be explicitly named: \ + `use crate as name;`", + ); + } + + let kind = ImportKind::Single { + source: source.ident, + target: ident, + source_bindings: PerNS { + type_ns: Cell::new(Err(Determinacy::Undetermined)), + value_ns: Cell::new(Err(Determinacy::Undetermined)), + macro_ns: Cell::new(Err(Determinacy::Undetermined)), + }, + target_bindings: PerNS { + type_ns: Cell::new(None), + value_ns: Cell::new(None), + macro_ns: Cell::new(None), + }, + type_ns_only, + nested, + additional_ids: (id1, id2), + }; + + self.add_import( + module_path, + kind, + use_tree.span, + id, + item, + root_span, + item.id, + vis, + ); + } + ast::UseTreeKind::Glob => { + let kind = ImportKind::Glob { + is_prelude: self.r.session.contains_name(&item.attrs, sym::prelude_import), + max_vis: Cell::new(ty::Visibility::Invisible), + }; + self.r.visibilities.insert(self.r.local_def_id(id), vis); + self.add_import(prefix, kind, use_tree.span, id, item, root_span, item.id, vis); + } + ast::UseTreeKind::Nested(ref items) => { + // Ensure there is at most one `self` in the list + let self_spans = items + .iter() + .filter_map(|&(ref use_tree, _)| { + if let ast::UseTreeKind::Simple(..) = use_tree.kind { + if use_tree.ident().name == kw::SelfLower { + return Some(use_tree.span); + } + } + + None + }) + .collect::<Vec<_>>(); + if self_spans.len() > 1 { + let mut e = self.r.into_struct_error( + self_spans[0], + ResolutionError::SelfImportCanOnlyAppearOnceInTheList, + ); + + for other_span in self_spans.iter().skip(1) { + e.span_label(*other_span, "another `self` import appears here"); + } + + e.emit(); + } + + for &(ref tree, id) in items { + self.build_reduced_graph_for_use_tree( + // This particular use tree + tree, id, &prefix, true, // The whole `use` item + item, vis, root_span, + ); + } + + // Empty groups `a::b::{}` are turned into synthetic `self` imports + // `a::b::c::{self as _}`, so that their prefixes are correctly + // resolved and checked for privacy/stability/etc. + if items.is_empty() && !empty_for_self(&prefix) { + let new_span = prefix[prefix.len() - 1].ident.span; + let tree = ast::UseTree { + prefix: ast::Path::from_ident(Ident::new(kw::SelfLower, new_span)), + kind: ast::UseTreeKind::Simple( + Some(Ident::new(kw::Underscore, new_span)), + ast::DUMMY_NODE_ID, + ast::DUMMY_NODE_ID, + ), + span: use_tree.span, + }; + self.build_reduced_graph_for_use_tree( + // This particular use tree + &tree, + id, + &prefix, + true, + // The whole `use` item + item, + ty::Visibility::Invisible, + root_span, + ); + } + } + } + } + + /// Constructs the reduced graph for one item. + fn build_reduced_graph_for_item(&mut self, item: &'b Item) { + let parent_scope = &self.parent_scope; + let parent = parent_scope.module; + let expansion = parent_scope.expansion; + let ident = item.ident; + let sp = item.span; + let vis = self.resolve_visibility(&item.vis); + let local_def_id = self.r.local_def_id(item.id); + let def_id = local_def_id.to_def_id(); + + self.r.visibilities.insert(local_def_id, vis); + + match item.kind { + ItemKind::Use(ref use_tree) => { + self.build_reduced_graph_for_use_tree( + // This particular use tree + use_tree, + item.id, + &[], + false, + // The whole `use` item + item, + vis, + use_tree.span, + ); + } + + ItemKind::ExternCrate(orig_name) => { + self.build_reduced_graph_for_extern_crate( + orig_name, + item, + local_def_id, + vis, + parent, + ); + } + + ItemKind::Mod(..) => { + let module = self.r.new_module( + Some(parent), + ModuleKind::Def(DefKind::Mod, def_id, ident.name), + expansion.to_expn_id(), + item.span, + parent.no_implicit_prelude + || self.r.session.contains_name(&item.attrs, sym::no_implicit_prelude), + ); + self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion)); + + // Descend into the module. + self.parent_scope.module = module; + } + + // These items live in the value namespace. + ItemKind::Static(_, mt, _) => { + let res = Res::Def(DefKind::Static(mt), def_id); + self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion)); + } + ItemKind::Const(..) => { + let res = Res::Def(DefKind::Const, def_id); + self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion)); + } + ItemKind::Fn(..) => { + let res = Res::Def(DefKind::Fn, def_id); + self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion)); + + // Functions introducing procedural macros reserve a slot + // in the macro namespace as well (see #52225). + self.define_macro(item); + } + + // These items live in the type namespace. + ItemKind::TyAlias(..) => { + let res = Res::Def(DefKind::TyAlias, def_id); + self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion)); + } + + ItemKind::Enum(_, _) => { + let module = self.r.new_module( + Some(parent), + ModuleKind::Def(DefKind::Enum, def_id, ident.name), + expansion.to_expn_id(), + item.span, + parent.no_implicit_prelude, + ); + self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion)); + self.parent_scope.module = module; + } + + ItemKind::TraitAlias(..) => { + let res = Res::Def(DefKind::TraitAlias, def_id); + self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion)); + } + + // These items live in both the type and value namespaces. + ItemKind::Struct(ref vdata, _) => { + // Define a name in the type namespace. + let res = Res::Def(DefKind::Struct, def_id); + self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion)); + + // Record field names for error reporting. + self.insert_field_names_local(def_id, vdata); + + // If this is a tuple or unit struct, define a name + // in the value namespace as well. + if let Some(ctor_node_id) = vdata.ctor_id() { + // If the structure is marked as non_exhaustive then lower the visibility + // to within the crate. + let mut ctor_vis = if vis == ty::Visibility::Public + && self.r.session.contains_name(&item.attrs, sym::non_exhaustive) + { + ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id()) + } else { + vis + }; + + let mut ret_fields = Vec::with_capacity(vdata.fields().len()); + + for field in vdata.fields() { + // NOTE: The field may be an expansion placeholder, but expansion sets + // correct visibilities for unnamed field placeholders specifically, so the + // constructor visibility should still be determined correctly. + let field_vis = self + .try_resolve_visibility(&field.vis, false) + .unwrap_or(ty::Visibility::Public); + if ctor_vis.is_at_least(field_vis, &*self.r) { + ctor_vis = field_vis; + } + ret_fields.push(field_vis); + } + let ctor_def_id = self.r.local_def_id(ctor_node_id); + let ctor_res = Res::Def( + DefKind::Ctor(CtorOf::Struct, CtorKind::from_ast(vdata)), + ctor_def_id.to_def_id(), + ); + self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion)); + self.r.visibilities.insert(ctor_def_id, ctor_vis); + + self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis, ret_fields)); + } + } + + ItemKind::Union(ref vdata, _) => { + let res = Res::Def(DefKind::Union, def_id); + self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion)); + + // Record field names for error reporting. + self.insert_field_names_local(def_id, vdata); + } + + ItemKind::Trait(..) => { + // Add all the items within to a new module. + let module = self.r.new_module( + Some(parent), + ModuleKind::Def(DefKind::Trait, def_id, ident.name), + expansion.to_expn_id(), + item.span, + parent.no_implicit_prelude, + ); + self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion)); + self.parent_scope.module = module; + } + + // These items do not add names to modules. + ItemKind::Impl(box Impl { of_trait: Some(..), .. }) => { + self.r.trait_impl_items.insert(local_def_id); + } + ItemKind::Impl { .. } | ItemKind::ForeignMod(..) | ItemKind::GlobalAsm(..) => {} + + ItemKind::MacroDef(..) | ItemKind::MacCall(_) => unreachable!(), + } + } + + fn build_reduced_graph_for_extern_crate( + &mut self, + orig_name: Option<Symbol>, + item: &Item, + local_def_id: LocalDefId, + vis: ty::Visibility, + parent: Module<'a>, + ) { + let ident = item.ident; + let sp = item.span; + let parent_scope = self.parent_scope; + let expansion = parent_scope.expansion; + + let (used, module, binding) = if orig_name.is_none() && ident.name == kw::SelfLower { + self.r + .session + .struct_span_err(item.span, "`extern crate self;` requires renaming") + .span_suggestion( + item.span, + "rename the `self` crate to be able to import it", + "extern crate self as name;", + Applicability::HasPlaceholders, + ) + .emit(); + return; + } else if orig_name == Some(kw::SelfLower) { + Some(self.r.graph_root) + } else { + self.r.crate_loader.process_extern_crate(item, &self.r.definitions, local_def_id).map( + |crate_id| { + self.r.extern_crate_map.insert(local_def_id, crate_id); + self.r.expect_module(crate_id.as_def_id()) + }, + ) + } + .map(|module| { + let used = self.process_macro_use_imports(item, module); + let binding = + (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas); + (used, Some(ModuleOrUniformRoot::Module(module)), binding) + }) + .unwrap_or((true, None, self.r.dummy_binding)); + let import = self.r.arenas.alloc_import(Import { + kind: ImportKind::ExternCrate { source: orig_name, target: ident }, + root_id: item.id, + id: item.id, + parent_scope: self.parent_scope, + imported_module: Cell::new(module), + has_attributes: !item.attrs.is_empty(), + use_span_with_attributes: item.span_with_attributes(), + use_span: item.span, + root_span: item.span, + span: item.span, + module_path: Vec::new(), + vis: Cell::new(vis), + used: Cell::new(used), + }); + self.r.potentially_unused_imports.push(import); + let imported_binding = self.r.import(binding, import); + if ptr::eq(parent, self.r.graph_root) { + if let Some(entry) = self.r.extern_prelude.get(&ident.normalize_to_macros_2_0()) { + if expansion != LocalExpnId::ROOT + && orig_name.is_some() + && entry.extern_crate_item.is_none() + { + let msg = "macro-expanded `extern crate` items cannot \ + shadow names passed with `--extern`"; + self.r.session.span_err(item.span, msg); + } + } + let entry = self.r.extern_prelude.entry(ident.normalize_to_macros_2_0()).or_insert( + ExternPreludeEntry { extern_crate_item: None, introduced_by_item: true }, + ); + entry.extern_crate_item = Some(imported_binding); + if orig_name.is_some() { + entry.introduced_by_item = true; + } + } + self.r.define(parent, ident, TypeNS, imported_binding); + } + + /// Constructs the reduced graph for one foreign item. + fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem) { + let local_def_id = self.r.local_def_id(item.id); + let def_id = local_def_id.to_def_id(); + let (def_kind, ns) = match item.kind { + ForeignItemKind::Fn(..) => (DefKind::Fn, ValueNS), + ForeignItemKind::Static(_, mt, _) => (DefKind::Static(mt), ValueNS), + ForeignItemKind::TyAlias(..) => (DefKind::ForeignTy, TypeNS), + ForeignItemKind::MacCall(_) => unreachable!(), + }; + let parent = self.parent_scope.module; + let expansion = self.parent_scope.expansion; + let vis = self.resolve_visibility(&item.vis); + let res = Res::Def(def_kind, def_id); + self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion)); + self.r.visibilities.insert(local_def_id, vis); + } + + fn build_reduced_graph_for_block(&mut self, block: &Block) { + let parent = self.parent_scope.module; + let expansion = self.parent_scope.expansion; + if self.block_needs_anonymous_module(block) { + let module = self.r.new_module( + Some(parent), + ModuleKind::Block, + expansion.to_expn_id(), + block.span, + parent.no_implicit_prelude, + ); + self.r.block_map.insert(block.id, module); + self.parent_scope.module = module; // Descend into the block. + } + } + + /// Builds the reduced graph for a single item in an external crate. + fn build_reduced_graph_for_external_crate_res(&mut self, child: ModChild) { + let parent = self.parent_scope.module; + let ModChild { ident, res, vis, span, macro_rules } = child; + let res = res.expect_non_local(); + let expansion = self.parent_scope.expansion; + // Record primary definitions. + match res { + Res::Def(DefKind::Mod | DefKind::Enum | DefKind::Trait, def_id) => { + let module = self.r.expect_module(def_id); + self.r.define(parent, ident, TypeNS, (module, vis, span, expansion)); + } + Res::Def( + DefKind::Struct + | DefKind::Union + | DefKind::Variant + | DefKind::TyAlias + | DefKind::ForeignTy + | DefKind::OpaqueTy + | DefKind::TraitAlias + | DefKind::AssocTy, + _, + ) + | Res::PrimTy(..) + | Res::ToolMod => self.r.define(parent, ident, TypeNS, (res, vis, span, expansion)), + Res::Def( + DefKind::Fn + | DefKind::AssocFn + | DefKind::Static(_) + | DefKind::Const + | DefKind::AssocConst + | DefKind::Ctor(..), + _, + ) => self.r.define(parent, ident, ValueNS, (res, vis, span, expansion)), + Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => { + if !macro_rules { + self.r.define(parent, ident, MacroNS, (res, vis, span, expansion)) + } + } + Res::Def( + DefKind::TyParam + | DefKind::ConstParam + | DefKind::ExternCrate + | DefKind::Use + | DefKind::ForeignMod + | DefKind::AnonConst + | DefKind::InlineConst + | DefKind::Field + | DefKind::LifetimeParam + | DefKind::GlobalAsm + | DefKind::Closure + | DefKind::Impl + | DefKind::Generator, + _, + ) + | Res::Local(..) + | Res::SelfTy { .. } + | Res::SelfCtor(..) + | Res::Err => bug!("unexpected resolution: {:?}", res), + } + // Record some extra data for better diagnostics. + let cstore = self.r.cstore(); + match res { + Res::Def(DefKind::Struct, def_id) => { + let field_names = + cstore.struct_field_names_untracked(def_id, self.r.session).collect(); + let ctor = cstore.ctor_def_id_and_kind_untracked(def_id); + if let Some((ctor_def_id, ctor_kind)) = ctor { + let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id); + let ctor_vis = cstore.visibility_untracked(ctor_def_id); + let field_visibilities = + cstore.struct_field_visibilities_untracked(def_id).collect(); + self.r + .struct_constructors + .insert(def_id, (ctor_res, ctor_vis, field_visibilities)); + } + self.insert_field_names(def_id, field_names); + } + Res::Def(DefKind::Union, def_id) => { + let field_names = + cstore.struct_field_names_untracked(def_id, self.r.session).collect(); + self.insert_field_names(def_id, field_names); + } + Res::Def(DefKind::AssocFn, def_id) => { + if cstore.fn_has_self_parameter_untracked(def_id) { + self.r.has_self.insert(def_id); + } + } + _ => {} + } + } + + fn add_macro_use_binding( + &mut self, + name: Symbol, + binding: &'a NameBinding<'a>, + span: Span, + allow_shadowing: bool, + ) { + if self.r.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing { + let msg = format!("`{}` is already in scope", name); + let note = + "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)"; + self.r.session.struct_span_err(span, &msg).note(note).emit(); + } + } + + /// Returns `true` if we should consider the underlying `extern crate` to be used. + fn process_macro_use_imports(&mut self, item: &Item, module: Module<'a>) -> bool { + let mut import_all = None; + let mut single_imports = Vec::new(); + for attr in &item.attrs { + if attr.has_name(sym::macro_use) { + if self.parent_scope.module.parent.is_some() { + struct_span_err!( + self.r.session, + item.span, + E0468, + "an `extern crate` loading macros must be at the crate root" + ) + .emit(); + } + if let ItemKind::ExternCrate(Some(orig_name)) = item.kind { + if orig_name == kw::SelfLower { + self.r + .session + .struct_span_err( + attr.span, + "`#[macro_use]` is not supported on `extern crate self`", + ) + .emit(); + } + } + let ill_formed = |span| { + struct_span_err!(self.r.session, span, E0466, "bad macro import").emit(); + }; + match attr.meta() { + Some(meta) => match meta.kind { + MetaItemKind::Word => { + import_all = Some(meta.span); + break; + } + MetaItemKind::List(nested_metas) => { + for nested_meta in nested_metas { + match nested_meta.ident() { + Some(ident) if nested_meta.is_word() => { + single_imports.push(ident) + } + _ => ill_formed(nested_meta.span()), + } + } + } + MetaItemKind::NameValue(..) => ill_formed(meta.span), + }, + None => ill_formed(attr.span), + } + } + } + + let macro_use_import = |this: &Self, span| { + this.r.arenas.alloc_import(Import { + kind: ImportKind::MacroUse, + root_id: item.id, + id: item.id, + parent_scope: this.parent_scope, + imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))), + use_span_with_attributes: item.span_with_attributes(), + has_attributes: !item.attrs.is_empty(), + use_span: item.span, + root_span: span, + span, + module_path: Vec::new(), + vis: Cell::new(ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id())), + used: Cell::new(false), + }) + }; + + let allow_shadowing = self.parent_scope.expansion == LocalExpnId::ROOT; + if let Some(span) = import_all { + let import = macro_use_import(self, span); + self.r.potentially_unused_imports.push(import); + module.for_each_child(self, |this, ident, ns, binding| { + if ns == MacroNS { + let imported_binding = this.r.import(binding, import); + this.add_macro_use_binding(ident.name, imported_binding, span, allow_shadowing); + } + }); + } else { + for ident in single_imports.iter().cloned() { + let result = self.r.maybe_resolve_ident_in_module( + ModuleOrUniformRoot::Module(module), + ident, + MacroNS, + &self.parent_scope, + ); + if let Ok(binding) = result { + let import = macro_use_import(self, ident.span); + self.r.potentially_unused_imports.push(import); + let imported_binding = self.r.import(binding, import); + self.add_macro_use_binding( + ident.name, + imported_binding, + ident.span, + allow_shadowing, + ); + } else { + struct_span_err!(self.r.session, ident.span, E0469, "imported macro not found") + .emit(); + } + } + } + import_all.is_some() || !single_imports.is_empty() + } + + /// Returns `true` if this attribute list contains `macro_use`. + fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool { + for attr in attrs { + if attr.has_name(sym::macro_escape) { + let msg = "`#[macro_escape]` is a deprecated synonym for `#[macro_use]`"; + let mut err = self.r.session.struct_span_warn(attr.span, msg); + if let ast::AttrStyle::Inner = attr.style { + err.help("try an outer attribute: `#[macro_use]`").emit(); + } else { + err.emit(); + } + } else if !attr.has_name(sym::macro_use) { + continue; + } + + if !attr.is_word() { + self.r.session.span_err(attr.span, "arguments to `macro_use` are not allowed here"); + } + return true; + } + + false + } + + fn visit_invoc(&mut self, id: NodeId) -> LocalExpnId { + let invoc_id = id.placeholder_to_expn_id(); + let old_parent_scope = self.r.invocation_parent_scopes.insert(invoc_id, self.parent_scope); + assert!(old_parent_scope.is_none(), "invocation data is reset for an invocation"); + invoc_id + } + + /// Visit invocation in context in which it can emit a named item (possibly `macro_rules`) + /// directly into its parent scope's module. + fn visit_invoc_in_module(&mut self, id: NodeId) -> MacroRulesScopeRef<'a> { + let invoc_id = self.visit_invoc(id); + self.parent_scope.module.unexpanded_invocations.borrow_mut().insert(invoc_id); + self.r.arenas.alloc_macro_rules_scope(MacroRulesScope::Invocation(invoc_id)) + } + + fn proc_macro_stub(&self, item: &ast::Item) -> Option<(MacroKind, Ident, Span)> { + if self.r.session.contains_name(&item.attrs, sym::proc_macro) { + return Some((MacroKind::Bang, item.ident, item.span)); + } else if self.r.session.contains_name(&item.attrs, sym::proc_macro_attribute) { + return Some((MacroKind::Attr, item.ident, item.span)); + } else if let Some(attr) = self.r.session.find_by_name(&item.attrs, sym::proc_macro_derive) + { + if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) { + if let Some(ident) = nested_meta.ident() { + return Some((MacroKind::Derive, ident, ident.span)); + } + } + } + None + } + + // Mark the given macro as unused unless its name starts with `_`. + // Macro uses will remove items from this set, and the remaining + // items will be reported as `unused_macros`. + fn insert_unused_macro( + &mut self, + ident: Ident, + def_id: LocalDefId, + node_id: NodeId, + rule_spans: &[(usize, Span)], + ) { + if !ident.as_str().starts_with('_') { + self.r.unused_macros.insert(def_id, (node_id, ident)); + for (rule_i, rule_span) in rule_spans.iter() { + self.r.unused_macro_rules.insert((def_id, *rule_i), (ident, *rule_span)); + } + } + } + + fn define_macro(&mut self, item: &ast::Item) -> MacroRulesScopeRef<'a> { + let parent_scope = self.parent_scope; + let expansion = parent_scope.expansion; + let def_id = self.r.local_def_id(item.id); + let (ext, ident, span, macro_rules, rule_spans) = match &item.kind { + ItemKind::MacroDef(def) => { + let (ext, rule_spans) = self.r.compile_macro(item, self.r.session.edition()); + let ext = Lrc::new(ext); + (ext, item.ident, item.span, def.macro_rules, rule_spans) + } + ItemKind::Fn(..) => match self.proc_macro_stub(item) { + Some((macro_kind, ident, span)) => { + self.r.proc_macro_stubs.insert(def_id); + (self.r.dummy_ext(macro_kind), ident, span, false, Vec::new()) + } + None => return parent_scope.macro_rules, + }, + _ => unreachable!(), + }; + + let res = Res::Def(DefKind::Macro(ext.macro_kind()), def_id.to_def_id()); + self.r.macro_map.insert(def_id.to_def_id(), MacroData { ext, macro_rules }); + self.r.local_macro_def_scopes.insert(def_id, parent_scope.module); + + if macro_rules { + let ident = ident.normalize_to_macros_2_0(); + self.r.macro_names.insert(ident); + let is_macro_export = self.r.session.contains_name(&item.attrs, sym::macro_export); + let vis = if is_macro_export { + ty::Visibility::Public + } else { + ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id()) + }; + let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas); + self.r.set_binding_parent_module(binding, parent_scope.module); + if is_macro_export { + let module = self.r.graph_root; + self.r.define(module, ident, MacroNS, (res, vis, span, expansion, IsMacroExport)); + } else { + self.r.check_reserved_macro_name(ident, res); + self.insert_unused_macro(ident, def_id, item.id, &rule_spans); + } + self.r.visibilities.insert(def_id, vis); + let scope = self.r.arenas.alloc_macro_rules_scope(MacroRulesScope::Binding( + self.r.arenas.alloc_macro_rules_binding(MacroRulesBinding { + parent_macro_rules_scope: parent_scope.macro_rules, + binding, + ident, + }), + )); + self.r.macro_rules_scopes.insert(def_id, scope); + scope + } else { + let module = parent_scope.module; + let vis = match item.kind { + // Visibilities must not be resolved non-speculatively twice + // and we already resolved this one as a `fn` item visibility. + ItemKind::Fn(..) => { + self.try_resolve_visibility(&item.vis, false).unwrap_or(ty::Visibility::Public) + } + _ => self.resolve_visibility(&item.vis), + }; + if vis != ty::Visibility::Public { + self.insert_unused_macro(ident, def_id, item.id, &rule_spans); + } + self.r.define(module, ident, MacroNS, (res, vis, span, expansion)); + self.r.visibilities.insert(def_id, vis); + self.parent_scope.macro_rules + } + } +} + +macro_rules! method { + ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => { + fn $visit(&mut self, node: &'b $ty) { + if let $invoc(..) = node.kind { + self.visit_invoc(node.id); + } else { + visit::$walk(self, node); + } + } + }; +} + +impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> { + method!(visit_expr: ast::Expr, ast::ExprKind::MacCall, walk_expr); + method!(visit_pat: ast::Pat, ast::PatKind::MacCall, walk_pat); + method!(visit_ty: ast::Ty, ast::TyKind::MacCall, walk_ty); + + fn visit_item(&mut self, item: &'b Item) { + let orig_module_scope = self.parent_scope.module; + self.parent_scope.macro_rules = match item.kind { + ItemKind::MacroDef(..) => { + let macro_rules_scope = self.define_macro(item); + visit::walk_item(self, item); + macro_rules_scope + } + ItemKind::MacCall(..) => { + let macro_rules_scope = self.visit_invoc_in_module(item.id); + visit::walk_item(self, item); + macro_rules_scope + } + _ => { + let orig_macro_rules_scope = self.parent_scope.macro_rules; + self.build_reduced_graph_for_item(item); + visit::walk_item(self, item); + match item.kind { + ItemKind::Mod(..) if self.contains_macro_use(&item.attrs) => { + self.parent_scope.macro_rules + } + _ => orig_macro_rules_scope, + } + } + }; + self.parent_scope.module = orig_module_scope; + } + + fn visit_stmt(&mut self, stmt: &'b ast::Stmt) { + if let ast::StmtKind::MacCall(..) = stmt.kind { + self.parent_scope.macro_rules = self.visit_invoc_in_module(stmt.id); + } else { + visit::walk_stmt(self, stmt); + } + } + + fn visit_foreign_item(&mut self, foreign_item: &'b ForeignItem) { + if let ForeignItemKind::MacCall(_) = foreign_item.kind { + self.visit_invoc_in_module(foreign_item.id); + return; + } + + self.build_reduced_graph_for_foreign_item(foreign_item); + visit::walk_foreign_item(self, foreign_item); + } + + fn visit_block(&mut self, block: &'b Block) { + let orig_current_module = self.parent_scope.module; + let orig_current_macro_rules_scope = self.parent_scope.macro_rules; + self.build_reduced_graph_for_block(block); + visit::walk_block(self, block); + self.parent_scope.module = orig_current_module; + self.parent_scope.macro_rules = orig_current_macro_rules_scope; + } + + fn visit_assoc_item(&mut self, item: &'b AssocItem, ctxt: AssocCtxt) { + if let AssocItemKind::MacCall(_) = item.kind { + match ctxt { + AssocCtxt::Trait => { + self.visit_invoc_in_module(item.id); + } + AssocCtxt::Impl => { + self.visit_invoc(item.id); + } + } + return; + } + + let vis = self.resolve_visibility(&item.vis); + let local_def_id = self.r.local_def_id(item.id); + let def_id = local_def_id.to_def_id(); + + if !(ctxt == AssocCtxt::Impl + && matches!(item.vis.kind, ast::VisibilityKind::Inherited) + && self + .r + .trait_impl_items + .contains(&ty::DefIdTree::local_parent(&*self.r, local_def_id))) + { + // Trait impl item visibility is inherited from its trait when not specified + // explicitly. In that case we cannot determine it here in early resolve, + // so we leave a hole in the visibility table to be filled later. + self.r.visibilities.insert(local_def_id, vis); + } + + if ctxt == AssocCtxt::Trait { + let (def_kind, ns) = match item.kind { + AssocItemKind::Const(..) => (DefKind::AssocConst, ValueNS), + AssocItemKind::Fn(box Fn { ref sig, .. }) => { + if sig.decl.has_self() { + self.r.has_self.insert(def_id); + } + (DefKind::AssocFn, ValueNS) + } + AssocItemKind::TyAlias(..) => (DefKind::AssocTy, TypeNS), + AssocItemKind::MacCall(_) => bug!(), // handled above + }; + + let parent = self.parent_scope.module; + let expansion = self.parent_scope.expansion; + let res = Res::Def(def_kind, def_id); + self.r.define(parent, item.ident, ns, (res, vis, item.span, expansion)); + } + + visit::walk_assoc_item(self, item, ctxt); + } + + fn visit_attribute(&mut self, attr: &'b ast::Attribute) { + if !attr.is_doc_comment() && attr::is_builtin_attr(attr) { + self.r + .builtin_attrs + .push((attr.get_normal_item().path.segments[0].ident, self.parent_scope)); + } + visit::walk_attribute(self, attr); + } + + fn visit_arm(&mut self, arm: &'b ast::Arm) { + if arm.is_placeholder { + self.visit_invoc(arm.id); + } else { + visit::walk_arm(self, arm); + } + } + + fn visit_expr_field(&mut self, f: &'b ast::ExprField) { + if f.is_placeholder { + self.visit_invoc(f.id); + } else { + visit::walk_expr_field(self, f); + } + } + + fn visit_pat_field(&mut self, fp: &'b ast::PatField) { + if fp.is_placeholder { + self.visit_invoc(fp.id); + } else { + visit::walk_pat_field(self, fp); + } + } + + fn visit_generic_param(&mut self, param: &'b ast::GenericParam) { + if param.is_placeholder { + self.visit_invoc(param.id); + } else { + visit::walk_generic_param(self, param); + } + } + + fn visit_param(&mut self, p: &'b ast::Param) { + if p.is_placeholder { + self.visit_invoc(p.id); + } else { + visit::walk_param(self, p); + } + } + + fn visit_field_def(&mut self, sf: &'b ast::FieldDef) { + if sf.is_placeholder { + self.visit_invoc(sf.id); + } else { + let vis = self.resolve_visibility(&sf.vis); + self.r.visibilities.insert(self.r.local_def_id(sf.id), vis); + visit::walk_field_def(self, sf); + } + } + + // Constructs the reduced graph for one variant. Variants exist in the + // type and value namespaces. + fn visit_variant(&mut self, variant: &'b ast::Variant) { + if variant.is_placeholder { + self.visit_invoc_in_module(variant.id); + return; + } + + let parent = self.parent_scope.module; + let expn_id = self.parent_scope.expansion; + let ident = variant.ident; + + // Define a name in the type namespace. + let def_id = self.r.local_def_id(variant.id); + let res = Res::Def(DefKind::Variant, def_id.to_def_id()); + let vis = self.resolve_visibility(&variant.vis); + self.r.define(parent, ident, TypeNS, (res, vis, variant.span, expn_id)); + self.r.visibilities.insert(def_id, vis); + + // If the variant is marked as non_exhaustive then lower the visibility to within the crate. + let ctor_vis = if vis == ty::Visibility::Public + && self.r.session.contains_name(&variant.attrs, sym::non_exhaustive) + { + ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id()) + } else { + vis + }; + + // Define a constructor name in the value namespace. + // Braced variants, unlike structs, generate unusable names in + // value namespace, they are reserved for possible future use. + // It's ok to use the variant's id as a ctor id since an + // error will be reported on any use of such resolution anyway. + let ctor_node_id = variant.data.ctor_id().unwrap_or(variant.id); + let ctor_def_id = self.r.local_def_id(ctor_node_id); + let ctor_kind = CtorKind::from_ast(&variant.data); + let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Variant, ctor_kind), ctor_def_id.to_def_id()); + self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, variant.span, expn_id)); + if ctor_def_id != def_id { + self.r.visibilities.insert(ctor_def_id, ctor_vis); + } + // Record field names for error reporting. + self.insert_field_names_local(ctor_def_id.to_def_id(), &variant.data); + + visit::walk_variant(self, variant); + } + + fn visit_crate(&mut self, krate: &'b ast::Crate) { + if krate.is_placeholder { + self.visit_invoc_in_module(krate.id); + } else { + visit::walk_crate(self, krate); + self.contains_macro_use(&krate.attrs); + } + } +} |