1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Reduced graph building
13 //! Here we build the "reduced graph": the graph of the module tree without
14 //! any imports resolved.
16 use macros::{InvocationData, LegacyScope};
17 use resolve_imports::ImportDirective;
18 use resolve_imports::ImportDirectiveSubclass::{self, GlobImport, SingleImport};
19 use {Module, ModuleData, ModuleKind, NameBinding, NameBindingKind, ToNameBinding};
20 use {ModuleOrUniformRoot, PerNS, Resolver, ResolverArenas};
21 use Namespace::{self, TypeNS, ValueNS, MacroNS};
22 use {resolve_error, resolve_struct_error, ResolutionError};
24 use rustc::hir::def::*;
25 use rustc::hir::def_id::{BUILTIN_MACROS_CRATE, CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
27 use rustc::middle::cstore::CrateStore;
28 use rustc_metadata::cstore::LoadedMacro;
31 use rustc_data_structures::sync::Lrc;
33 use syntax::ast::{Name, Ident};
36 use syntax::ast::{self, Block, ForeignItem, ForeignItemKind, Item, ItemKind, NodeId};
37 use syntax::ast::{Mutability, StmtKind, TraitItem, TraitItemKind, Variant};
38 use syntax::ext::base::{MacroKind, SyntaxExtension};
39 use syntax::ext::base::Determinacy::Undetermined;
40 use syntax::ext::hygiene::Mark;
41 use syntax::ext::tt::macro_rules;
42 use syntax::feature_gate::is_builtin_attr;
43 use syntax::parse::token::{self, Token};
44 use syntax::std_inject::injected_crate_name;
45 use syntax::symbol::keywords;
46 use syntax::visit::{self, Visitor};
48 use syntax_pos::{Span, DUMMY_SP};
50 impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, Mark) {
51 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
52 arenas.alloc_name_binding(NameBinding {
53 kind: NameBindingKind::Module(self.0),
61 impl<'a> ToNameBinding<'a> for (Def, ty::Visibility, Span, Mark) {
62 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
63 arenas.alloc_name_binding(NameBinding {
64 kind: NameBindingKind::Def(self.0, false),
72 pub(crate) struct IsMacroExport;
74 impl<'a> ToNameBinding<'a> for (Def, ty::Visibility, Span, Mark, IsMacroExport) {
75 fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
76 arenas.alloc_name_binding(NameBinding {
77 kind: NameBindingKind::Def(self.0, true),
85 #[derive(Default, PartialEq, Eq)]
86 struct LegacyMacroImports {
87 import_all: Option<Span>,
88 imports: Vec<(Name, Span)>,
91 impl<'a, 'cl> Resolver<'a, 'cl> {
92 /// Defines `name` in namespace `ns` of module `parent` to be `def` if it is not yet defined;
93 /// otherwise, reports an error.
94 pub 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 if let Err(old_binding) = self.try_define(parent, ident, ns, binding) {
99 self.report_conflict(parent, ident, ns, old_binding, &binding);
103 fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
104 // If any statements are items, we need to create an anonymous module
105 block.stmts.iter().any(|statement| match statement.node {
106 StmtKind::Item(_) | StmtKind::Mac(_) => true,
111 fn insert_field_names(&mut self, def_id: DefId, field_names: Vec<Name>) {
112 if !field_names.is_empty() {
113 self.field_names.insert(def_id, field_names);
117 fn build_reduced_graph_for_use_tree(
119 root_use_tree: &ast::UseTree,
121 use_tree: &ast::UseTree,
124 parent_prefix: &[Ident],
125 mut uniform_paths_canary_emitted: bool,
130 debug!("build_reduced_graph_for_use_tree(parent_prefix={:?}, \
131 uniform_paths_canary_emitted={}, \
132 use_tree={:?}, nested={})",
133 parent_prefix, uniform_paths_canary_emitted, use_tree, nested);
135 let is_prelude = attr::contains_name(&item.attrs, "prelude_import");
137 self.session.rust_2018() &&
138 self.session.features_untracked().uniform_paths;
140 let prefix_iter = || parent_prefix.iter().cloned()
141 .chain(use_tree.prefix.segments.iter().map(|seg| seg.ident));
142 let prefix_start = prefix_iter().nth(0);
143 let starts_with_non_keyword = prefix_start.map_or(false, |ident| {
144 !ident.is_path_segment_keyword()
147 // Imports are resolved as global by default, prepend `CrateRoot`,
148 // unless `#![feature(uniform_paths)]` is enabled.
149 let inject_crate_root =
151 match use_tree.kind {
152 // HACK(eddyb) special-case `use *` to mean `use ::*`.
153 ast::UseTreeKind::Glob if prefix_start.is_none() => true,
154 _ => starts_with_non_keyword,
156 let root = if inject_crate_root {
157 let span = use_tree.prefix.span.shrink_to_lo();
158 Some(Ident::new(keywords::CrateRoot.name(), span))
163 let prefix: Vec<_> = root.into_iter().chain(prefix_iter()).collect();
165 debug!("build_reduced_graph_for_use_tree: prefix={:?}", prefix);
167 // `#[feature(uniform_paths)]` allows an unqualified import path,
168 // e.g. `use x::...;` to resolve not just globally (`use ::x::...;`)
169 // but also relatively (`use self::x::...;`). To catch ambiguities
170 // that might arise from both of these being available and resolution
171 // silently picking one of them, an artificial `use self::x as _;`
172 // import is injected as a "canary", and an error is emitted if it
173 // successfully resolves while an `x` external crate exists.
175 // For each block scope around the `use` item, one special canary
176 // import of the form `use x as _;` is also injected, having its
177 // parent set to that scope; `resolve_imports` will only resolve
178 // it within its appropriate scope; if any of them successfully
179 // resolve, an ambiguity error is emitted, since the original
180 // import can't see the item in the block scope (`self::x` only
181 // looks in the enclosing module), but a non-`use` path could.
183 // Additionally, the canary might be able to catch limitations of the
184 // current implementation, where `::x` may be chosen due to `self::x`
185 // not existing, but `self::x` could appear later, from macro expansion.
187 // NB. The canary currently only errors if the `x::...` path *could*
188 // resolve as a relative path through the extern crate, i.e. `x` is
189 // in `extern_prelude`, *even though* `::x` might still forcefully
190 // load a non-`extern_prelude` crate.
191 // While always producing an ambiguity errors if `self::x` exists and
192 // a crate *could* be loaded, would be more conservative, imports for
193 // local modules named `test` (or less commonly, `syntax` or `log`),
194 // would need to be qualified (e.g. `self::test`), which is considered
195 // ergonomically unacceptable.
196 let emit_uniform_paths_canary =
197 !uniform_paths_canary_emitted &&
198 self.session.rust_2018() &&
199 starts_with_non_keyword;
200 if emit_uniform_paths_canary {
201 let source = prefix_start.unwrap();
203 // Helper closure to emit a canary with the given base path.
204 let emit = |this: &mut Self, base: Option<Ident>| {
205 let subclass = SingleImport {
207 name: keywords::Underscore.name().gensymed(),
212 type_ns: Cell::new(Err(Undetermined)),
213 value_ns: Cell::new(Err(Undetermined)),
214 macro_ns: Cell::new(Err(Undetermined)),
218 this.add_import_directive(
219 base.into_iter().collect(),
225 ty::Visibility::Invisible,
227 true, // is_uniform_paths_canary
231 // A single simple `self::x` canary.
232 emit(self, Some(Ident {
233 name: keywords::SelfValue.name(),
237 // One special unprefixed canary per block scope around
238 // the import, to detect items unreachable by `self::x`.
239 let orig_current_module = self.current_module;
240 let mut span = source.span.modern();
242 match self.current_module.kind {
243 ModuleKind::Block(..) => emit(self, None),
244 ModuleKind::Def(..) => break,
246 match self.hygienic_lexical_parent(self.current_module, &mut span) {
248 self.current_module = module;
253 self.current_module = orig_current_module;
255 uniform_paths_canary_emitted = true;
258 match use_tree.kind {
259 ast::UseTreeKind::Simple(rename, ..) => {
260 let mut ident = use_tree.ident();
261 let mut module_path = prefix;
262 let mut source = module_path.pop().unwrap();
263 let mut type_ns_only = false;
266 // Correctly handle `self`
267 if source.name == keywords::SelfValue.name() {
270 let empty_prefix = module_path.last().map_or(true, |ident| {
271 ident.name == keywords::CrateRoot.name()
278 SelfImportOnlyInImportListWithNonEmptyPrefix
283 // Replace `use foo::self;` with `use foo;`
284 source = module_path.pop().unwrap();
285 if rename.is_none() {
291 if source.name == keywords::SelfValue.name() {
294 ResolutionError::SelfImportsOnlyAllowedWithin);
297 // Disallow `use $crate;`
298 if source.name == keywords::DollarCrate.name() && module_path.is_empty() {
299 let crate_root = self.resolve_crate_root(source);
300 let crate_name = match crate_root.kind {
301 ModuleKind::Def(_, name) => name,
302 ModuleKind::Block(..) => unreachable!(),
304 // HACK(eddyb) unclear how good this is, but keeping `$crate`
305 // in `source` breaks `src/test/compile-fail/import-crate-var.rs`,
306 // while the current crate doesn't have a valid `crate_name`.
307 if crate_name != keywords::Invalid.name() {
308 // `crate_name` should not be interpreted as relative.
309 module_path.push(Ident {
310 name: keywords::CrateRoot.name(),
313 source.name = crate_name;
315 if rename.is_none() {
316 ident.name = crate_name;
319 self.session.struct_span_warn(item.span, "`$crate` may not be imported")
320 .note("`use $crate;` was erroneously allowed and \
321 will become a hard error in a future release")
326 if ident.name == keywords::Crate.name() {
327 self.session.span_err(ident.span,
328 "crate root imports need to be explicitly named: \
329 `use crate as name;`");
332 let subclass = SingleImport {
336 type_ns: Cell::new(Err(Undetermined)),
337 value_ns: Cell::new(Err(Undetermined)),
338 macro_ns: Cell::new(Err(Undetermined)),
342 self.add_import_directive(
351 false, // is_uniform_paths_canary
354 ast::UseTreeKind::Glob => {
355 let subclass = GlobImport {
357 max_vis: Cell::new(ty::Visibility::Invisible),
359 self.add_import_directive(
368 false, // is_uniform_paths_canary
371 ast::UseTreeKind::Nested(ref items) => {
372 // Ensure there is at most one `self` in the list
373 let self_spans = items.iter().filter_map(|&(ref use_tree, _)| {
374 if let ast::UseTreeKind::Simple(..) = use_tree.kind {
375 if use_tree.ident().name == keywords::SelfValue.name() {
376 return Some(use_tree.span);
381 }).collect::<Vec<_>>();
382 if self_spans.len() > 1 {
383 let mut e = resolve_struct_error(self,
385 ResolutionError::SelfImportCanOnlyAppearOnceInTheList);
387 for other_span in self_spans.iter().skip(1) {
388 e.span_label(*other_span, "another `self` import appears here");
394 for &(ref tree, id) in items {
395 self.build_reduced_graph_for_use_tree(
402 uniform_paths_canary_emitted,
412 /// Constructs the reduced graph for one item.
413 fn build_reduced_graph_for_item(&mut self, item: &Item, expansion: Mark) {
414 let parent = self.current_module;
415 let ident = item.ident;
417 let vis = self.resolve_visibility(&item.vis);
420 ItemKind::Use(ref use_tree) => {
421 self.build_reduced_graph_for_use_tree(
428 false, // uniform_paths_canary_emitted
435 ItemKind::ExternCrate(orig_name) => {
436 let crate_id = self.crate_loader.process_extern_crate(item, &self.definitions);
438 self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
439 self.populate_module_if_necessary(module);
440 if injected_crate_name().map_or(false, |name| item.ident.name == name) {
441 self.injected_crate = Some(module);
444 let used = self.process_legacy_macro_imports(item, module, expansion);
446 (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.arenas);
447 let directive = self.arenas.alloc_import_directive(ImportDirective {
451 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
452 subclass: ImportDirectiveSubclass::ExternCrate(orig_name),
453 root_span: item.span,
455 module_path: Vec::new(),
458 used: Cell::new(used),
459 is_uniform_paths_canary: false,
461 self.potentially_unused_imports.push(directive);
462 let imported_binding = self.import(binding, directive);
463 self.define(parent, ident, TypeNS, imported_binding);
466 ItemKind::GlobalAsm(..) => {}
468 ItemKind::Mod(..) if item.ident == keywords::Invalid.ident() => {} // Crate root
470 ItemKind::Mod(..) => {
471 let def_id = self.definitions.local_def_id(item.id);
472 let module_kind = ModuleKind::Def(Def::Mod(def_id), ident.name);
473 let module = self.arenas.alloc_module(ModuleData {
474 no_implicit_prelude: parent.no_implicit_prelude || {
475 attr::contains_name(&item.attrs, "no_implicit_prelude")
477 ..ModuleData::new(Some(parent), module_kind, def_id, expansion, item.span)
479 self.define(parent, ident, TypeNS, (module, vis, sp, expansion));
480 self.module_map.insert(def_id, module);
482 // Descend into the module.
483 self.current_module = module;
486 // Handled in `rustc_metadata::{native_libs,link_args}`
487 ItemKind::ForeignMod(..) => {}
489 // These items live in the value namespace.
490 ItemKind::Static(_, m, _) => {
491 let mutbl = m == Mutability::Mutable;
492 let def = Def::Static(self.definitions.local_def_id(item.id), mutbl);
493 self.define(parent, ident, ValueNS, (def, vis, sp, expansion));
495 ItemKind::Const(..) => {
496 let def = Def::Const(self.definitions.local_def_id(item.id));
497 self.define(parent, ident, ValueNS, (def, vis, sp, expansion));
499 ItemKind::Fn(..) => {
500 let def = Def::Fn(self.definitions.local_def_id(item.id));
501 self.define(parent, ident, ValueNS, (def, vis, sp, expansion));
503 // Functions introducing procedural macros reserve a slot
504 // in the macro namespace as well (see #52225).
505 if attr::contains_name(&item.attrs, "proc_macro") ||
506 attr::contains_name(&item.attrs, "proc_macro_attribute") {
507 let def = Def::Macro(def.def_id(), MacroKind::ProcMacroStub);
508 self.define(parent, ident, MacroNS, (def, vis, sp, expansion));
510 if let Some(attr) = attr::find_by_name(&item.attrs, "proc_macro_derive") {
511 if let Some(trait_attr) =
512 attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
513 if let Some(ident) = trait_attr.name().map(Ident::with_empty_ctxt) {
514 let sp = trait_attr.span;
515 let def = Def::Macro(def.def_id(), MacroKind::ProcMacroStub);
516 self.define(parent, ident, MacroNS, (def, vis, sp, expansion));
522 // These items live in the type namespace.
523 ItemKind::Ty(..) => {
524 let def = Def::TyAlias(self.definitions.local_def_id(item.id));
525 self.define(parent, ident, TypeNS, (def, vis, sp, expansion));
528 ItemKind::Existential(_, _) => {
529 let def = Def::Existential(self.definitions.local_def_id(item.id));
530 self.define(parent, ident, TypeNS, (def, vis, sp, expansion));
533 ItemKind::Enum(ref enum_definition, _) => {
534 let def = Def::Enum(self.definitions.local_def_id(item.id));
535 let module_kind = ModuleKind::Def(def, ident.name);
536 let module = self.new_module(parent,
538 parent.normal_ancestor_id,
541 self.define(parent, ident, TypeNS, (module, vis, sp, expansion));
543 for variant in &(*enum_definition).variants {
544 self.build_reduced_graph_for_variant(variant, module, vis, expansion);
548 ItemKind::TraitAlias(..) => {
549 let def = Def::TraitAlias(self.definitions.local_def_id(item.id));
550 self.define(parent, ident, TypeNS, (def, vis, sp, expansion));
553 // These items live in both the type and value namespaces.
554 ItemKind::Struct(ref struct_def, _) => {
555 // Define a name in the type namespace.
556 let def_id = self.definitions.local_def_id(item.id);
557 let def = Def::Struct(def_id);
558 self.define(parent, ident, TypeNS, (def, vis, sp, expansion));
560 let mut ctor_vis = vis;
562 let has_non_exhaustive = attr::contains_name(&item.attrs, "non_exhaustive");
564 // If the structure is marked as non_exhaustive then lower the visibility
565 // to within the crate.
566 if has_non_exhaustive && vis == ty::Visibility::Public {
567 ctor_vis = ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX));
570 // Record field names for error reporting.
571 let field_names = struct_def.fields().iter().filter_map(|field| {
572 let field_vis = self.resolve_visibility(&field.vis);
573 if ctor_vis.is_at_least(field_vis, &*self) {
574 ctor_vis = field_vis;
576 field.ident.map(|ident| ident.name)
578 let item_def_id = self.definitions.local_def_id(item.id);
579 self.insert_field_names(item_def_id, field_names);
581 // If this is a tuple or unit struct, define a name
582 // in the value namespace as well.
583 if !struct_def.is_struct() {
584 let ctor_def = Def::StructCtor(self.definitions.local_def_id(struct_def.id()),
585 CtorKind::from_ast(struct_def));
586 self.define(parent, ident, ValueNS, (ctor_def, ctor_vis, sp, expansion));
587 self.struct_constructors.insert(def.def_id(), (ctor_def, ctor_vis));
588 self.tuple_structs.insert(def.def_id(), ctor_def);
592 ItemKind::Union(ref vdata, _) => {
593 let def = Def::Union(self.definitions.local_def_id(item.id));
594 self.define(parent, ident, TypeNS, (def, vis, sp, expansion));
596 // Record field names for error reporting.
597 let field_names = vdata.fields().iter().filter_map(|field| {
598 self.resolve_visibility(&field.vis);
599 field.ident.map(|ident| ident.name)
601 let item_def_id = self.definitions.local_def_id(item.id);
602 self.insert_field_names(item_def_id, field_names);
605 ItemKind::Impl(..) => {}
607 ItemKind::Trait(..) => {
608 let def_id = self.definitions.local_def_id(item.id);
610 // Add all the items within to a new module.
611 let module_kind = ModuleKind::Def(Def::Trait(def_id), ident.name);
612 let module = self.new_module(parent,
614 parent.normal_ancestor_id,
617 self.define(parent, ident, TypeNS, (module, vis, sp, expansion));
618 self.current_module = module;
621 ItemKind::MacroDef(..) | ItemKind::Mac(_) => unreachable!(),
625 // Constructs the reduced graph for one variant. Variants exist in the
626 // type and value namespaces.
627 fn build_reduced_graph_for_variant(&mut self,
632 let ident = variant.node.ident;
633 let def_id = self.definitions.local_def_id(variant.node.data.id());
635 // Define a name in the type namespace.
636 let def = Def::Variant(def_id);
637 self.define(parent, ident, TypeNS, (def, vis, variant.span, expansion));
639 // Define a constructor name in the value namespace.
640 // Braced variants, unlike structs, generate unusable names in
641 // value namespace, they are reserved for possible future use.
642 let ctor_kind = CtorKind::from_ast(&variant.node.data);
643 let ctor_def = Def::VariantCtor(def_id, ctor_kind);
645 self.define(parent, ident, ValueNS, (ctor_def, vis, variant.span, expansion));
648 /// Constructs the reduced graph for one foreign item.
649 fn build_reduced_graph_for_foreign_item(&mut self, item: &ForeignItem, expansion: Mark) {
650 let (def, ns) = match item.node {
651 ForeignItemKind::Fn(..) => {
652 (Def::Fn(self.definitions.local_def_id(item.id)), ValueNS)
654 ForeignItemKind::Static(_, m) => {
655 (Def::Static(self.definitions.local_def_id(item.id), m), ValueNS)
657 ForeignItemKind::Ty => {
658 (Def::ForeignTy(self.definitions.local_def_id(item.id)), TypeNS)
660 ForeignItemKind::Macro(_) => unreachable!(),
662 let parent = self.current_module;
663 let vis = self.resolve_visibility(&item.vis);
664 self.define(parent, item.ident, ns, (def, vis, item.span, expansion));
667 fn build_reduced_graph_for_block(&mut self, block: &Block, expansion: Mark) {
668 let parent = self.current_module;
669 if self.block_needs_anonymous_module(block) {
670 let module = self.new_module(parent,
671 ModuleKind::Block(block.id),
672 parent.normal_ancestor_id,
675 self.block_map.insert(block.id, module);
676 self.current_module = module; // Descend into the block.
680 /// Builds the reduced graph for a single item in an external crate.
681 fn build_reduced_graph_for_external_crate_def(&mut self, parent: Module<'a>, child: Export) {
682 let Export { ident, def, vis, span, .. } = child;
683 let def_id = def.def_id();
684 let expansion = Mark::root(); // FIXME(jseyfried) intercrate hygiene
686 Def::Mod(..) | Def::Enum(..) => {
687 let module = self.new_module(parent,
688 ModuleKind::Def(def, ident.name),
692 self.define(parent, ident, TypeNS, (module, vis, DUMMY_SP, expansion));
694 Def::Variant(..) | Def::TyAlias(..) | Def::ForeignTy(..) => {
695 self.define(parent, ident, TypeNS, (def, vis, DUMMY_SP, expansion));
697 Def::Fn(..) | Def::Static(..) | Def::Const(..) | Def::VariantCtor(..) => {
698 self.define(parent, ident, ValueNS, (def, vis, DUMMY_SP, expansion));
700 Def::StructCtor(..) => {
701 self.define(parent, ident, ValueNS, (def, vis, DUMMY_SP, expansion));
703 if let Some(struct_def_id) =
704 self.cstore.def_key(def_id).parent
705 .map(|index| DefId { krate: def_id.krate, index: index }) {
706 self.struct_constructors.insert(struct_def_id, (def, vis));
707 self.tuple_structs.insert(struct_def_id, def);
711 let module_kind = ModuleKind::Def(def, ident.name);
712 let module = self.new_module(parent,
714 parent.normal_ancestor_id,
717 self.define(parent, ident, TypeNS, (module, vis, DUMMY_SP, expansion));
719 for child in self.cstore.item_children_untracked(def_id, self.session) {
720 let ns = if let Def::AssociatedTy(..) = child.def { TypeNS } else { ValueNS };
721 self.define(module, child.ident, ns,
722 (child.def, ty::Visibility::Public, DUMMY_SP, expansion));
724 if self.cstore.associated_item_cloned_untracked(child.def.def_id())
725 .method_has_self_argument {
726 self.has_self.insert(child.def.def_id());
729 module.populated.set(true);
731 Def::Struct(..) | Def::Union(..) => {
732 self.define(parent, ident, TypeNS, (def, vis, DUMMY_SP, expansion));
734 // Record field names for error reporting.
735 let field_names = self.cstore.struct_field_names_untracked(def_id);
736 self.insert_field_names(def_id, field_names);
739 self.define(parent, ident, MacroNS, (def, vis, DUMMY_SP, expansion));
741 _ => bug!("unexpected definition: {:?}", def)
745 pub fn get_module(&mut self, def_id: DefId) -> Module<'a> {
746 if def_id.krate == LOCAL_CRATE {
747 return self.module_map[&def_id]
750 let macros_only = self.cstore.dep_kind_untracked(def_id.krate).macros_only();
751 if let Some(&module) = self.extern_module_map.get(&(def_id, macros_only)) {
755 let (name, parent) = if def_id.index == CRATE_DEF_INDEX {
756 (self.cstore.crate_name_untracked(def_id.krate).as_interned_str(), None)
758 let def_key = self.cstore.def_key(def_id);
759 (def_key.disambiguated_data.data.get_opt_name().unwrap(),
760 Some(self.get_module(DefId { index: def_key.parent.unwrap(), ..def_id })))
763 let kind = ModuleKind::Def(Def::Mod(def_id), name.as_symbol());
765 self.arenas.alloc_module(ModuleData::new(parent, kind, def_id, Mark::root(), DUMMY_SP));
766 self.extern_module_map.insert((def_id, macros_only), module);
770 pub fn macro_def_scope(&mut self, expansion: Mark) -> Module<'a> {
771 let def_id = self.macro_defs[&expansion];
772 if let Some(id) = self.definitions.as_local_node_id(def_id) {
773 self.local_macro_def_scopes[&id]
774 } else if def_id.krate == BUILTIN_MACROS_CRATE {
775 self.injected_crate.unwrap_or(self.graph_root)
777 let module_def_id = ty::DefIdTree::parent(&*self, def_id).unwrap();
778 self.get_module(module_def_id)
782 pub fn get_macro(&mut self, def: Def) -> Lrc<SyntaxExtension> {
783 let def_id = match def {
784 Def::Macro(def_id, ..) => def_id,
785 Def::NonMacroAttr(attr_kind) => return Lrc::new(SyntaxExtension::NonMacroAttr {
786 mark_used: attr_kind == NonMacroAttrKind::Tool,
788 _ => panic!("expected `Def::Macro` or `Def::NonMacroAttr`"),
790 if let Some(ext) = self.macro_map.get(&def_id) {
794 let macro_def = match self.cstore.load_macro_untracked(def_id, &self.session) {
795 LoadedMacro::MacroDef(macro_def) => macro_def,
796 LoadedMacro::ProcMacro(ext) => return ext,
799 let ext = Lrc::new(macro_rules::compile(&self.session.parse_sess,
800 &self.session.features_untracked(),
802 self.cstore.crate_edition_untracked(def_id.krate)));
803 self.macro_map.insert(def_id, ext.clone());
807 /// Ensures that the reduced graph rooted at the given external module
808 /// is built, building it if it is not.
809 pub fn populate_module_if_necessary(&mut self, module: Module<'a>) {
810 if module.populated.get() { return }
811 let def_id = module.def_id().unwrap();
812 for child in self.cstore.item_children_untracked(def_id, self.session) {
813 self.build_reduced_graph_for_external_crate_def(module, child);
815 module.populated.set(true)
818 fn legacy_import_macro(&mut self,
820 binding: &'a NameBinding<'a>,
822 allow_shadowing: bool) {
823 if self.macro_use_prelude.insert(name, binding).is_some() && !allow_shadowing {
824 let msg = format!("`{}` is already in scope", name);
826 "macro-expanded `#[macro_use]`s may not shadow existing macros (see RFC 1560)";
827 self.session.struct_span_err(span, &msg).note(note).emit();
831 // This returns true if we should consider the underlying `extern crate` to be used.
832 fn process_legacy_macro_imports(&mut self, item: &Item, module: Module<'a>, expansion: Mark)
834 let allow_shadowing = expansion == Mark::root();
835 let legacy_imports = self.legacy_macro_imports(&item.attrs);
836 let used = legacy_imports != LegacyMacroImports::default();
838 // `#[macro_use]` is only allowed at the crate root.
839 if self.current_module.parent.is_some() && used {
840 span_err!(self.session, item.span, E0468,
841 "an `extern crate` loading macros must be at the crate root");
844 let (graph_root, arenas) = (self.graph_root, self.arenas);
845 let macro_use_directive = |span| arenas.alloc_import_directive(ImportDirective {
849 imported_module: Cell::new(Some(ModuleOrUniformRoot::Module(module))),
850 subclass: ImportDirectiveSubclass::MacroUse,
853 module_path: Vec::new(),
854 vis: Cell::new(ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))),
856 used: Cell::new(false),
857 is_uniform_paths_canary: false,
860 if let Some(span) = legacy_imports.import_all {
861 let directive = macro_use_directive(span);
862 self.potentially_unused_imports.push(directive);
863 module.for_each_child(|ident, ns, binding| if ns == MacroNS {
864 let imported_binding = self.import(binding, directive);
865 self.legacy_import_macro(ident.name, imported_binding, span, allow_shadowing);
868 for (name, span) in legacy_imports.imports {
869 let ident = Ident::with_empty_ctxt(name);
870 let result = self.resolve_ident_in_module(
871 ModuleOrUniformRoot::Module(module),
877 if let Ok(binding) = result {
878 let directive = macro_use_directive(span);
879 self.potentially_unused_imports.push(directive);
880 let imported_binding = self.import(binding, directive);
881 self.legacy_import_macro(name, imported_binding, span, allow_shadowing);
883 span_err!(self.session, span, E0469, "imported macro not found");
890 // does this attribute list contain "macro_use"?
891 fn contains_macro_use(&mut self, attrs: &[ast::Attribute]) -> bool {
893 if attr.check_name("macro_escape") {
894 let msg = "macro_escape is a deprecated synonym for macro_use";
895 let mut err = self.session.struct_span_warn(attr.span, msg);
896 if let ast::AttrStyle::Inner = attr.style {
897 err.help("consider an outer attribute, #[macro_use] mod ...").emit();
901 } else if !attr.check_name("macro_use") {
906 self.session.span_err(attr.span, "arguments to macro_use are not allowed here");
914 fn legacy_macro_imports(&mut self, attrs: &[ast::Attribute]) -> LegacyMacroImports {
915 let mut imports = LegacyMacroImports::default();
917 if attr.check_name("macro_use") {
918 match attr.meta_item_list() {
919 Some(names) => for attr in names {
920 if let Some(word) = attr.word() {
921 imports.imports.push((word.name(), attr.span()));
923 span_err!(self.session, attr.span(), E0466, "bad macro import");
926 None => imports.import_all = Some(attr.span),
934 pub struct BuildReducedGraphVisitor<'a, 'b: 'a, 'c: 'b> {
935 pub resolver: &'a mut Resolver<'b, 'c>,
936 pub current_legacy_scope: LegacyScope<'b>,
940 impl<'a, 'b, 'cl> BuildReducedGraphVisitor<'a, 'b, 'cl> {
941 fn visit_invoc(&mut self, id: ast::NodeId) -> &'b InvocationData<'b> {
942 let mark = id.placeholder_to_mark();
943 self.resolver.current_module.unresolved_invocations.borrow_mut().insert(mark);
944 let invocation = self.resolver.invocations[&mark];
945 invocation.module.set(self.resolver.current_module);
946 invocation.parent_legacy_scope.set(self.current_legacy_scope);
947 invocation.output_legacy_scope.set(self.current_legacy_scope);
952 macro_rules! method {
953 ($visit:ident: $ty:ty, $invoc:path, $walk:ident) => {
954 fn $visit(&mut self, node: &'a $ty) {
955 if let $invoc(..) = node.node {
956 self.visit_invoc(node.id);
958 visit::$walk(self, node);
964 impl<'a, 'b, 'cl> Visitor<'a> for BuildReducedGraphVisitor<'a, 'b, 'cl> {
965 method!(visit_impl_item: ast::ImplItem, ast::ImplItemKind::Macro, walk_impl_item);
966 method!(visit_expr: ast::Expr, ast::ExprKind::Mac, walk_expr);
967 method!(visit_pat: ast::Pat, ast::PatKind::Mac, walk_pat);
968 method!(visit_ty: ast::Ty, ast::TyKind::Mac, walk_ty);
970 fn visit_item(&mut self, item: &'a Item) {
971 let macro_use = match item.node {
972 ItemKind::MacroDef(..) => {
973 self.resolver.define_macro(item, self.expansion, &mut self.current_legacy_scope);
976 ItemKind::Mac(..) => {
977 self.current_legacy_scope = LegacyScope::Invocation(self.visit_invoc(item.id));
980 ItemKind::Mod(..) => self.resolver.contains_macro_use(&item.attrs),
984 let orig_current_module = self.resolver.current_module;
985 let orig_current_legacy_scope = self.current_legacy_scope;
986 self.resolver.build_reduced_graph_for_item(item, self.expansion);
987 visit::walk_item(self, item);
988 self.resolver.current_module = orig_current_module;
990 self.current_legacy_scope = orig_current_legacy_scope;
994 fn visit_stmt(&mut self, stmt: &'a ast::Stmt) {
995 if let ast::StmtKind::Mac(..) = stmt.node {
996 self.current_legacy_scope = LegacyScope::Invocation(self.visit_invoc(stmt.id));
998 visit::walk_stmt(self, stmt);
1002 fn visit_foreign_item(&mut self, foreign_item: &'a ForeignItem) {
1003 if let ForeignItemKind::Macro(_) = foreign_item.node {
1004 self.visit_invoc(foreign_item.id);
1008 self.resolver.build_reduced_graph_for_foreign_item(foreign_item, self.expansion);
1009 visit::walk_foreign_item(self, foreign_item);
1012 fn visit_block(&mut self, block: &'a Block) {
1013 let orig_current_module = self.resolver.current_module;
1014 let orig_current_legacy_scope = self.current_legacy_scope;
1015 self.resolver.build_reduced_graph_for_block(block, self.expansion);
1016 visit::walk_block(self, block);
1017 self.resolver.current_module = orig_current_module;
1018 self.current_legacy_scope = orig_current_legacy_scope;
1021 fn visit_trait_item(&mut self, item: &'a TraitItem) {
1022 let parent = self.resolver.current_module;
1024 if let TraitItemKind::Macro(_) = item.node {
1025 self.visit_invoc(item.id);
1029 // Add the item to the trait info.
1030 let item_def_id = self.resolver.definitions.local_def_id(item.id);
1031 let (def, ns) = match item.node {
1032 TraitItemKind::Const(..) => (Def::AssociatedConst(item_def_id), ValueNS),
1033 TraitItemKind::Method(ref sig, _) => {
1034 if sig.decl.has_self() {
1035 self.resolver.has_self.insert(item_def_id);
1037 (Def::Method(item_def_id), ValueNS)
1039 TraitItemKind::Type(..) => (Def::AssociatedTy(item_def_id), TypeNS),
1040 TraitItemKind::Macro(_) => bug!(), // handled above
1043 let vis = ty::Visibility::Public;
1044 self.resolver.define(parent, item.ident, ns, (def, vis, item.span, self.expansion));
1046 self.resolver.current_module = parent.parent.unwrap(); // nearest normal ancestor
1047 visit::walk_trait_item(self, item);
1048 self.resolver.current_module = parent;
1051 fn visit_token(&mut self, t: Token) {
1052 if let Token::Interpolated(nt) = t {
1054 token::NtExpr(ref expr) => {
1055 if let ast::ExprKind::Mac(..) = expr.node {
1056 self.visit_invoc(expr.id);
1064 fn visit_attribute(&mut self, attr: &'a ast::Attribute) {
1065 if !attr.is_sugared_doc && is_builtin_attr(attr) {
1066 self.resolver.current_module.builtin_attrs.borrow_mut().push((
1067 attr.path.segments[0].ident, self.expansion, self.current_legacy_scope
1070 visit::walk_attribute(self, attr);