1 //! This crate is responsible for the part of name resolution that doesn't require type checker.
3 //! Module structure of the crate is built here.
4 //! Paths in macros, imports, expressions, types, patterns are resolved here.
5 //! Label names are resolved here as well.
7 //! Type-relative name resolution (methods, fields, associated items) happens in `librustc_typeck`.
8 //! Lifetime names are resolved in `librustc/middle/resolve_lifetime.rs`.
10 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
12 #![feature(crate_visibility_modifier)]
13 #![feature(label_break_value)]
16 #![recursion_limit="256"]
18 pub use rustc
::hir
::def
::{Namespace, PerNS}
;
22 use rustc
::hir
::map
::Definitions
;
23 use rustc
::hir
::{self, PrimTy, Bool, Char, Float, Int, Uint, Str}
;
24 use rustc
::middle
::cstore
::{CrateStore, MetadataLoaderDyn}
;
25 use rustc
::session
::Session
;
27 use rustc
::hir
::def
::{self, DefKind, PartialRes, CtorKind, CtorOf, NonMacroAttrKind, ExportMap}
;
28 use rustc
::hir
::def
::Namespace
::*;
29 use rustc
::hir
::def_id
::{CRATE_DEF_INDEX, LOCAL_CRATE, CrateNum, DefId}
;
30 use rustc
::hir
::{TraitMap, GlobMap}
;
31 use rustc
::ty
::{self, DefIdTree, ResolverOutputs}
;
32 use rustc
::util
::nodemap
::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap}
;
35 use rustc_metadata
::creader
::CrateLoader
;
36 use rustc_metadata
::cstore
::CStore
;
38 use syntax
::{struct_span_err, unwrap_or}
;
39 use syntax
::expand
::SpecialDerives
;
40 use syntax
::ast
::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy}
;
41 use syntax
::ast
::{CRATE_NODE_ID, Crate}
;
42 use syntax
::ast
::{ItemKind, Path}
;
44 use syntax
::print
::pprust
;
45 use syntax
::symbol
::{kw, sym}
;
46 use syntax
::source_map
::Spanned
;
47 use syntax
::visit
::{self, Visitor}
;
48 use syntax_expand
::base
::SyntaxExtension
;
49 use syntax_pos
::hygiene
::{MacroKind, ExpnId, Transparency, SyntaxContext}
;
50 use syntax_pos
::{Span, DUMMY_SP}
;
51 use errors
::{Applicability, DiagnosticBuilder}
;
55 use std
::cell
::{Cell, RefCell}
;
56 use std
::{cmp, fmt, iter, ptr}
;
57 use std
::collections
::BTreeSet
;
58 use rustc_data_structures
::ptr_key
::PtrKey
;
59 use rustc_data_structures
::sync
::Lrc
;
60 use rustc_data_structures
::fx
::FxIndexMap
;
62 use diagnostics
::{Suggestion, ImportSuggestion}
;
63 use diagnostics
::{find_span_of_binding_until_next_binding, extend_span_to_previous_binding}
;
64 use late
::{HasGenericParams, PathSource, Rib, RibKind::*}
;
65 use resolve_imports
::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver}
;
66 use macros
::{LegacyBinding, LegacyScope}
;
68 type Res
= def
::Res
<NodeId
>;
75 mod build_reduced_graph
;
78 const KNOWN_TOOLS
: &[Name
] = &[sym
::clippy
, sym
::rustfmt
];
85 #[derive(Copy, Clone, PartialEq, Debug)]
86 pub enum Determinacy
{
92 fn determined(determined
: bool
) -> Determinacy
{
93 if determined { Determinacy::Determined }
else { Determinacy::Undetermined }
97 /// A specific scope in which a name can be looked up.
98 /// This enum is currently used only for early resolution (imports and macros),
99 /// but not for late resolution yet.
100 #[derive(Clone, Copy)]
103 MacroRules(LegacyScope
<'a
>),
115 /// Names from different contexts may want to visit different subsets of all specific scopes
116 /// with different restrictions when looking up the resolution.
117 /// This enum is currently used only for early resolution (imports and macros),
118 /// but not for late resolution yet.
120 /// All scopes with the given namespace.
121 All(Namespace
, /*is_import*/ bool
),
122 /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
123 AbsolutePath(Namespace
),
124 /// All scopes with macro namespace and the given macro kind restriction.
128 /// Everything you need to know about a name's location to resolve it.
129 /// Serves as a starting point for the scope visitor.
130 /// This struct is currently used only for early resolution (imports and macros),
131 /// but not for late resolution yet.
132 #[derive(Clone, Copy, Debug)]
133 pub struct ParentScope
<'a
> {
136 legacy
: LegacyScope
<'a
>,
137 derives
: &'a
[ast
::Path
],
140 impl<'a
> ParentScope
<'a
> {
141 /// Creates a parent scope with the passed argument used as the module scope component,
142 /// and other scope components set to default empty values.
143 pub fn module(module
: Module
<'a
>) -> ParentScope
<'a
> {
146 expansion
: ExpnId
::root(),
147 legacy
: LegacyScope
::Empty
,
154 struct BindingError
{
156 origin
: BTreeSet
<Span
>,
157 target
: BTreeSet
<Span
>,
161 impl PartialOrd
for BindingError
{
162 fn partial_cmp(&self, other
: &BindingError
) -> Option
<cmp
::Ordering
> {
163 Some(self.cmp(other
))
167 impl PartialEq
for BindingError
{
168 fn eq(&self, other
: &BindingError
) -> bool
{
169 self.name
== other
.name
173 impl Ord
for BindingError
{
174 fn cmp(&self, other
: &BindingError
) -> cmp
::Ordering
{
175 self.name
.cmp(&other
.name
)
179 enum ResolutionError
<'a
> {
180 /// Error E0401: can't use type or const parameters from outer function.
181 GenericParamsFromOuterFunction(Res
, HasGenericParams
),
182 /// Error E0403: the name is already used for a type or const parameter in this generic
184 NameAlreadyUsedInParameterList(Name
, Span
),
185 /// Error E0407: method is not a member of trait.
186 MethodNotMemberOfTrait(Name
, &'a
str),
187 /// Error E0437: type is not a member of trait.
188 TypeNotMemberOfTrait(Name
, &'a
str),
189 /// Error E0438: const is not a member of trait.
190 ConstNotMemberOfTrait(Name
, &'a
str),
191 /// Error E0408: variable `{}` is not bound in all patterns.
192 VariableNotBoundInPattern(&'a BindingError
),
193 /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
194 VariableBoundWithDifferentMode(Name
, Span
),
195 /// Error E0415: identifier is bound more than once in this parameter list.
196 IdentifierBoundMoreThanOnceInParameterList(&'a
str),
197 /// Error E0416: identifier is bound more than once in the same pattern.
198 IdentifierBoundMoreThanOnceInSamePattern(&'a
str),
199 /// Error E0426: use of undeclared label.
200 UndeclaredLabel(&'a
str, Option
<Name
>),
201 /// Error E0429: `self` imports are only allowed within a `{ }` list.
202 SelfImportsOnlyAllowedWithin
,
203 /// Error E0430: `self` import can only appear once in the list.
204 SelfImportCanOnlyAppearOnceInTheList
,
205 /// Error E0431: `self` import can only appear in an import list with a non-empty prefix.
206 SelfImportOnlyInImportListWithNonEmptyPrefix
,
207 /// Error E0433: failed to resolve.
208 FailedToResolve { label: String, suggestion: Option<Suggestion> }
,
209 /// Error E0434: can't capture dynamic environment in a fn item.
210 CannotCaptureDynamicEnvironmentInFnItem
,
211 /// Error E0435: attempt to use a non-constant value in a constant.
212 AttemptToUseNonConstantValueInConstant
,
213 /// Error E0530: `X` bindings cannot shadow `Y`s.
214 BindingShadowsSomethingUnacceptable(&'a
str, Name
, &'a NameBinding
<'a
>),
215 /// Error E0128: type parameters with a default cannot use forward-declared identifiers.
216 ForwardDeclaredTyParam
, // FIXME(const_generics:defaults)
217 /// Error E0735: type parameters with a default cannot use `Self`
218 SelfInTyParamDefault
,
221 enum VisResolutionError
<'a
> {
222 Relative2018(Span
, &'a ast
::Path
),
224 FailedToResolve(Span
, String
, Option
<Suggestion
>),
225 ExpectedFound(Span
, String
, Res
),
230 // A minimal representation of a path segment. We use this in resolve because
231 // we synthesize 'path segments' which don't have the rest of an AST or HIR
233 #[derive(Clone, Copy, Debug)]
240 fn from_path(path
: &Path
) -> Vec
<Segment
> {
241 path
.segments
.iter().map(|s
| s
.into()).collect()
244 fn from_ident(ident
: Ident
) -> Segment
{
251 fn names_to_string(segments
: &[Segment
]) -> String
{
252 names_to_string(&segments
.iter()
253 .map(|seg
| seg
.ident
.name
)
254 .collect
::<Vec
<_
>>())
258 impl<'a
> From
<&'a ast
::PathSegment
> for Segment
{
259 fn from(seg
: &'a ast
::PathSegment
) -> Segment
{
267 struct UsePlacementFinder
{
268 target_module
: NodeId
,
273 impl UsePlacementFinder
{
274 fn check(krate
: &Crate
, target_module
: NodeId
) -> (Option
<Span
>, bool
) {
275 let mut finder
= UsePlacementFinder
{
280 visit
::walk_crate(&mut finder
, krate
);
281 (finder
.span
, finder
.found_use
)
285 impl<'tcx
> Visitor
<'tcx
> for UsePlacementFinder
{
288 module
: &'tcx ast
::Mod
,
290 _
: &[ast
::Attribute
],
293 if self.span
.is_some() {
296 if node_id
!= self.target_module
{
297 visit
::walk_mod(self, module
);
300 // find a use statement
301 for item
in &module
.items
{
303 ItemKind
::Use(..) => {
304 // don't suggest placing a use before the prelude
305 // import or other generated ones
306 if !item
.span
.from_expansion() {
307 self.span
= Some(item
.span
.shrink_to_lo());
308 self.found_use
= true;
312 // don't place use before extern crate
313 ItemKind
::ExternCrate(_
) => {}
314 // but place them before the first other item
315 _
=> if self.span
.map_or(true, |span
| item
.span
< span
) {
316 if !item
.span
.from_expansion() {
317 // don't insert between attributes and an item
318 if item
.attrs
.is_empty() {
319 self.span
= Some(item
.span
.shrink_to_lo());
321 // find the first attribute on the item
322 for attr
in &item
.attrs
{
323 if self.span
.map_or(true, |span
| attr
.span
< span
) {
324 self.span
= Some(attr
.span
.shrink_to_lo());
335 /// An intermediate resolution result.
337 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
338 /// items are visible in their whole block, while `Res`es only from the place they are defined
341 enum LexicalScopeBinding
<'a
> {
342 Item(&'a NameBinding
<'a
>),
346 impl<'a
> LexicalScopeBinding
<'a
> {
347 fn item(self) -> Option
<&'a NameBinding
<'a
>> {
349 LexicalScopeBinding
::Item(binding
) => Some(binding
),
354 fn res(self) -> Res
{
356 LexicalScopeBinding
::Item(binding
) => binding
.res(),
357 LexicalScopeBinding
::Res(res
) => res
,
362 #[derive(Copy, Clone, Debug)]
363 enum ModuleOrUniformRoot
<'a
> {
367 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
368 CrateRootAndExternPrelude
,
370 /// Virtual module that denotes resolution in extern prelude.
371 /// Used for paths starting with `::` on 2018 edition.
374 /// Virtual module that denotes resolution in current scope.
375 /// Used only for resolving single-segment imports. The reason it exists is that import paths
376 /// are always split into two parts, the first of which should be some kind of module.
380 impl ModuleOrUniformRoot
<'_
> {
381 fn same_def(lhs
: Self, rhs
: Self) -> bool
{
383 (ModuleOrUniformRoot
::Module(lhs
),
384 ModuleOrUniformRoot
::Module(rhs
)) => lhs
.def_id() == rhs
.def_id(),
385 (ModuleOrUniformRoot
::CrateRootAndExternPrelude
,
386 ModuleOrUniformRoot
::CrateRootAndExternPrelude
) |
387 (ModuleOrUniformRoot
::ExternPrelude
, ModuleOrUniformRoot
::ExternPrelude
) |
388 (ModuleOrUniformRoot
::CurrentScope
, ModuleOrUniformRoot
::CurrentScope
) => true,
394 #[derive(Clone, Debug)]
395 enum PathResult
<'a
> {
396 Module(ModuleOrUniformRoot
<'a
>),
397 NonModule(PartialRes
),
402 suggestion
: Option
<Suggestion
>,
403 is_error_from_last_segment
: bool
,
408 /// An anonymous module; e.g., just a block.
413 /// { // This is an anonymous module
414 /// f(); // This resolves to (2) as we are inside the block.
417 /// f(); // Resolves to (1)
421 /// Any module with a name.
425 /// * A normal module ‒ either `mod from_file;` or `mod from_block { }`.
426 /// * A trait or an enum (it implicitly contains associated types, methods and variant
428 Def(DefKind
, DefId
, Name
),
432 /// Get name of the module.
433 pub fn name(&self) -> Option
<Name
> {
435 ModuleKind
::Block(..) => None
,
436 ModuleKind
::Def(.., name
) => Some(*name
),
441 /// A key that identifies a binding in a given `Module`.
443 /// Multiple bindings in the same module can have the same key (in a valid
444 /// program) if all but one of them come from glob imports.
445 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
447 /// The identifier for the binding, aways the `modern` version of the
451 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
452 /// `_` in the expanded AST that introduced this binding.
456 type Resolutions
<'a
> = RefCell
<FxIndexMap
<BindingKey
, &'a RefCell
<NameResolution
<'a
>>>>;
458 /// One node in the tree of modules.
459 pub struct ModuleData
<'a
> {
460 parent
: Option
<Module
<'a
>>,
463 // The def id of the closest normal module (`mod`) ancestor (including this module).
464 normal_ancestor_id
: DefId
,
466 // Mapping between names and their (possibly in-progress) resolutions in this module.
467 // Resolutions in modules from other crates are not populated until accessed.
468 lazy_resolutions
: Resolutions
<'a
>,
469 // True if this is a module from other crate that needs to be populated on access.
470 populate_on_access
: Cell
<bool
>,
472 // Macro invocations that can expand into items in this module.
473 unexpanded_invocations
: RefCell
<FxHashSet
<ExpnId
>>,
475 no_implicit_prelude
: bool
,
477 glob_importers
: RefCell
<Vec
<&'a ImportDirective
<'a
>>>,
478 globs
: RefCell
<Vec
<&'a ImportDirective
<'a
>>>,
480 // Used to memoize the traits in this module for faster searches through all traits in scope.
481 traits
: RefCell
<Option
<Box
<[(Ident
, &'a NameBinding
<'a
>)]>>>,
483 /// Span of the module itself. Used for error reporting.
489 type Module
<'a
> = &'a ModuleData
<'a
>;
491 impl<'a
> ModuleData
<'a
> {
492 fn new(parent
: Option
<Module
<'a
>>,
494 normal_ancestor_id
: DefId
,
496 span
: Span
) -> Self {
501 lazy_resolutions
: Default
::default(),
502 populate_on_access
: Cell
::new(!normal_ancestor_id
.is_local()),
503 unexpanded_invocations
: Default
::default(),
504 no_implicit_prelude
: false,
505 glob_importers
: RefCell
::new(Vec
::new()),
506 globs
: RefCell
::new(Vec
::new()),
507 traits
: RefCell
::new(None
),
513 fn for_each_child
<R
, F
>(&'a
self, resolver
: &mut R
, mut f
: F
)
514 where R
: AsMut
<Resolver
<'a
>>, F
: FnMut(&mut R
, Ident
, Namespace
, &'a NameBinding
<'a
>)
516 for (key
, name_resolution
) in resolver
.as_mut().resolutions(self).borrow().iter() {
517 name_resolution
.borrow().binding
.map(|binding
| f(resolver
, key
.ident
, key
.ns
, binding
));
521 fn res(&self) -> Option
<Res
> {
523 ModuleKind
::Def(kind
, def_id
, _
) => Some(Res
::Def(kind
, def_id
)),
528 fn def_id(&self) -> Option
<DefId
> {
530 ModuleKind
::Def(_
, def_id
, _
) => Some(def_id
),
535 // `self` resolves to the first module ancestor that `is_normal`.
536 fn is_normal(&self) -> bool
{
538 ModuleKind
::Def(DefKind
::Mod
, _
, _
) => true,
543 fn is_trait(&self) -> bool
{
545 ModuleKind
::Def(DefKind
::Trait
, _
, _
) => true,
550 fn nearest_item_scope(&'a
self) -> Module
<'a
> {
552 ModuleKind
::Def(DefKind
::Enum
, ..) | ModuleKind
::Def(DefKind
::Trait
, ..) =>
553 self.parent
.expect("enum or trait module without a parent"),
558 fn is_ancestor_of(&self, mut other
: &Self) -> bool
{
559 while !ptr
::eq(self, other
) {
560 if let Some(parent
) = other
.parent
{
570 impl<'a
> fmt
::Debug
for ModuleData
<'a
> {
571 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
572 write
!(f
, "{:?}", self.res())
576 /// Records a possibly-private value, type, or module definition.
577 #[derive(Clone, Debug)]
578 pub struct NameBinding
<'a
> {
579 kind
: NameBindingKind
<'a
>,
580 ambiguity
: Option
<(&'a NameBinding
<'a
>, AmbiguityKind
)>,
586 pub trait ToNameBinding
<'a
> {
587 fn to_name_binding(self, arenas
: &'a ResolverArenas
<'a
>) -> &'a NameBinding
<'a
>;
590 impl<'a
> ToNameBinding
<'a
> for &'a NameBinding
<'a
> {
591 fn to_name_binding(self, _
: &'a ResolverArenas
<'a
>) -> &'a NameBinding
<'a
> {
596 #[derive(Clone, Debug)]
597 enum NameBindingKind
<'a
> {
598 Res(Res
, /* is_macro_export */ bool
),
601 binding
: &'a NameBinding
<'a
>,
602 directive
: &'a ImportDirective
<'a
>,
607 impl<'a
> NameBindingKind
<'a
> {
608 /// Is this a name binding of a import?
609 fn is_import(&self) -> bool
{
611 NameBindingKind
::Import { .. }
=> true,
617 struct PrivacyError
<'a
>(Span
, Ident
, &'a NameBinding
<'a
>);
619 struct UseError
<'a
> {
620 err
: DiagnosticBuilder
<'a
>,
621 /// Attach `use` statements for these candidates.
622 candidates
: Vec
<ImportSuggestion
>,
623 /// The `NodeId` of the module to place the use-statements in.
625 /// Whether the diagnostic should state that it's "better".
629 #[derive(Clone, Copy, PartialEq, Debug)]
634 LegacyHelperVsPrelude
,
643 fn descr(self) -> &'
static str {
645 AmbiguityKind
::Import
=>
646 "name vs any other name during import resolution",
647 AmbiguityKind
::BuiltinAttr
=>
648 "built-in attribute vs any other name",
649 AmbiguityKind
::DeriveHelper
=>
650 "derive helper attribute vs any other name",
651 AmbiguityKind
::LegacyHelperVsPrelude
=>
652 "legacy plugin helper attribute vs name from prelude",
653 AmbiguityKind
::LegacyVsModern
=>
654 "`macro_rules` vs non-`macro_rules` from other module",
655 AmbiguityKind
::GlobVsOuter
=>
656 "glob import vs any other name from outer scope during import/macro resolution",
657 AmbiguityKind
::GlobVsGlob
=>
658 "glob import vs glob import in the same module",
659 AmbiguityKind
::GlobVsExpanded
=>
660 "glob import vs macro-expanded name in the same \
661 module during import/macro resolution",
662 AmbiguityKind
::MoreExpandedVsOuter
=>
663 "macro-expanded name vs less macro-expanded name \
664 from outer scope during import/macro resolution",
669 /// Miscellaneous bits of metadata for better ambiguity error reporting.
670 #[derive(Clone, Copy, PartialEq)]
671 enum AmbiguityErrorMisc
{
678 struct AmbiguityError
<'a
> {
681 b1
: &'a NameBinding
<'a
>,
682 b2
: &'a NameBinding
<'a
>,
683 misc1
: AmbiguityErrorMisc
,
684 misc2
: AmbiguityErrorMisc
,
687 impl<'a
> NameBinding
<'a
> {
688 fn module(&self) -> Option
<Module
<'a
>> {
690 NameBindingKind
::Module(module
) => Some(module
),
691 NameBindingKind
::Import { binding, .. }
=> binding
.module(),
696 fn res(&self) -> Res
{
698 NameBindingKind
::Res(res
, _
) => res
,
699 NameBindingKind
::Module(module
) => module
.res().unwrap(),
700 NameBindingKind
::Import { binding, .. }
=> binding
.res(),
704 fn is_ambiguity(&self) -> bool
{
705 self.ambiguity
.is_some() || match self.kind
{
706 NameBindingKind
::Import { binding, .. }
=> binding
.is_ambiguity(),
711 // We sometimes need to treat variants as `pub` for backwards compatibility.
712 fn pseudo_vis(&self) -> ty
::Visibility
{
713 if self.is_variant() && self.res().def_id().is_local() {
714 ty
::Visibility
::Public
720 fn is_variant(&self) -> bool
{
722 NameBindingKind
::Res(Res
::Def(DefKind
::Variant
, _
), _
) |
723 NameBindingKind
::Res(Res
::Def(DefKind
::Ctor(CtorOf
::Variant
, ..), _
), _
) => true,
728 fn is_extern_crate(&self) -> bool
{
730 NameBindingKind
::Import
{
731 directive
: &ImportDirective
{
732 subclass
: ImportDirectiveSubclass
::ExternCrate { .. }
, ..
735 NameBindingKind
::Module(
736 &ModuleData { kind: ModuleKind::Def(DefKind::Mod, def_id, _), .. }
737 ) => def_id
.index
== CRATE_DEF_INDEX
,
742 fn is_import(&self) -> bool
{
744 NameBindingKind
::Import { .. }
=> true,
749 fn is_glob_import(&self) -> bool
{
751 NameBindingKind
::Import { directive, .. }
=> directive
.is_glob(),
756 fn is_importable(&self) -> bool
{
758 Res
::Def(DefKind
::AssocConst
, _
)
759 | Res
::Def(DefKind
::Method
, _
)
760 | Res
::Def(DefKind
::AssocTy
, _
) => false,
765 fn is_macro_def(&self) -> bool
{
767 NameBindingKind
::Res(Res
::Def(DefKind
::Macro(..), _
), _
) => true,
772 fn macro_kind(&self) -> Option
<MacroKind
> {
773 self.res().macro_kind()
776 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
777 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
778 // Then this function returns `true` if `self` may emerge from a macro *after* that
779 // in some later round and screw up our previously found resolution.
780 // See more detailed explanation in
781 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
782 fn may_appear_after(&self, invoc_parent_expansion
: ExpnId
, binding
: &NameBinding
<'_
>) -> bool
{
783 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
784 // Expansions are partially ordered, so "may appear after" is an inversion of
785 // "certainly appears before or simultaneously" and includes unordered cases.
786 let self_parent_expansion
= self.expansion
;
787 let other_parent_expansion
= binding
.expansion
;
788 let certainly_before_other_or_simultaneously
=
789 other_parent_expansion
.is_descendant_of(self_parent_expansion
);
790 let certainly_before_invoc_or_simultaneously
=
791 invoc_parent_expansion
.is_descendant_of(self_parent_expansion
);
792 !(certainly_before_other_or_simultaneously
|| certainly_before_invoc_or_simultaneously
)
796 /// Interns the names of the primitive types.
798 /// All other types are defined somewhere and possibly imported, but the primitive ones need
799 /// special handling, since they have no place of origin.
800 struct PrimitiveTypeTable
{
801 primitive_types
: FxHashMap
<Name
, PrimTy
>,
804 impl PrimitiveTypeTable
{
805 fn new() -> PrimitiveTypeTable
{
806 let mut table
= FxHashMap
::default();
808 table
.insert(sym
::bool
, Bool
);
809 table
.insert(sym
::char, Char
);
810 table
.insert(sym
::f32, Float(FloatTy
::F32
));
811 table
.insert(sym
::f64, Float(FloatTy
::F64
));
812 table
.insert(sym
::isize, Int(IntTy
::Isize
));
813 table
.insert(sym
::i8, Int(IntTy
::I8
));
814 table
.insert(sym
::i16, Int(IntTy
::I16
));
815 table
.insert(sym
::i32, Int(IntTy
::I32
));
816 table
.insert(sym
::i64, Int(IntTy
::I64
));
817 table
.insert(sym
::i128
, Int(IntTy
::I128
));
818 table
.insert(sym
::str, Str
);
819 table
.insert(sym
::usize, Uint(UintTy
::Usize
));
820 table
.insert(sym
::u8, Uint(UintTy
::U8
));
821 table
.insert(sym
::u16, Uint(UintTy
::U16
));
822 table
.insert(sym
::u32, Uint(UintTy
::U32
));
823 table
.insert(sym
::u64, Uint(UintTy
::U64
));
824 table
.insert(sym
::u128
, Uint(UintTy
::U128
));
825 Self { primitive_types: table }
829 #[derive(Debug, Default, Clone)]
830 pub struct ExternPreludeEntry
<'a
> {
831 extern_crate_item
: Option
<&'a NameBinding
<'a
>>,
832 pub introduced_by_item
: bool
,
835 /// The main resolver class.
837 /// This is the visitor that walks the whole crate.
838 pub struct Resolver
<'a
> {
839 session
: &'a Session
,
841 definitions
: Definitions
,
843 graph_root
: Module
<'a
>,
845 prelude
: Option
<Module
<'a
>>,
846 extern_prelude
: FxHashMap
<Ident
, ExternPreludeEntry
<'a
>>,
848 /// N.B., this is used only for better diagnostics, not name resolution itself.
849 has_self
: FxHashSet
<DefId
>,
851 /// Names of fields of an item `DefId` accessible with dot syntax.
852 /// Used for hints during error reporting.
853 field_names
: FxHashMap
<DefId
, Vec
<Spanned
<Name
>>>,
855 /// All imports known to succeed or fail.
856 determined_imports
: Vec
<&'a ImportDirective
<'a
>>,
858 /// All non-determined imports.
859 indeterminate_imports
: Vec
<&'a ImportDirective
<'a
>>,
861 /// FIXME: Refactor things so that these fields are passed through arguments and not resolver.
862 /// We are resolving a last import segment during import validation.
863 last_import_segment
: bool
,
864 /// This binding should be ignored during in-module resolution, so that we don't get
865 /// "self-confirming" import resolutions during import validation.
866 blacklisted_binding
: Option
<&'a NameBinding
<'a
>>,
868 /// The idents for the primitive types.
869 primitive_type_table
: PrimitiveTypeTable
,
871 /// Resolutions for nodes that have a single resolution.
872 partial_res_map
: NodeMap
<PartialRes
>,
873 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
874 import_res_map
: NodeMap
<PerNS
<Option
<Res
>>>,
875 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
876 label_res_map
: NodeMap
<NodeId
>,
878 /// `CrateNum` resolutions of `extern crate` items.
879 extern_crate_map
: NodeMap
<CrateNum
>,
880 export_map
: ExportMap
<NodeId
>,
883 /// A map from nodes to anonymous modules.
884 /// Anonymous modules are pseudo-modules that are implicitly created around items
885 /// contained within blocks.
887 /// For example, if we have this:
895 /// There will be an anonymous module created around `g` with the ID of the
896 /// entry block for `f`.
897 block_map
: NodeMap
<Module
<'a
>>,
898 /// A fake module that contains no definition and no prelude. Used so that
899 /// some AST passes can generate identifiers that only resolve to local or
901 empty_module
: Module
<'a
>,
902 module_map
: FxHashMap
<DefId
, Module
<'a
>>,
903 extern_module_map
: FxHashMap
<DefId
, Module
<'a
>>,
904 binding_parent_modules
: FxHashMap
<PtrKey
<'a
, NameBinding
<'a
>>, Module
<'a
>>,
905 underscore_disambiguator
: u32,
907 /// Maps glob imports to the names of items actually imported.
910 used_imports
: FxHashSet
<(NodeId
, Namespace
)>,
911 maybe_unused_trait_imports
: NodeSet
,
912 maybe_unused_extern_crates
: Vec
<(NodeId
, Span
)>,
914 /// Privacy errors are delayed until the end in order to deduplicate them.
915 privacy_errors
: Vec
<PrivacyError
<'a
>>,
916 /// Ambiguity errors are delayed for deduplication.
917 ambiguity_errors
: Vec
<AmbiguityError
<'a
>>,
918 /// `use` injections are delayed for better placement and deduplication.
919 use_injections
: Vec
<UseError
<'a
>>,
920 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
921 macro_expanded_macro_export_errors
: BTreeSet
<(Span
, Span
)>,
923 arenas
: &'a ResolverArenas
<'a
>,
924 dummy_binding
: &'a NameBinding
<'a
>,
926 crate_loader
: CrateLoader
<'a
>,
927 macro_names
: FxHashSet
<Ident
>,
928 builtin_macros
: FxHashMap
<Name
, SyntaxExtension
>,
929 macro_use_prelude
: FxHashMap
<Name
, &'a NameBinding
<'a
>>,
930 all_macros
: FxHashMap
<Name
, Res
>,
931 macro_map
: FxHashMap
<DefId
, Lrc
<SyntaxExtension
>>,
932 dummy_ext_bang
: Lrc
<SyntaxExtension
>,
933 dummy_ext_derive
: Lrc
<SyntaxExtension
>,
934 non_macro_attrs
: [Lrc
<SyntaxExtension
>; 2],
935 macro_defs
: FxHashMap
<ExpnId
, DefId
>,
936 local_macro_def_scopes
: FxHashMap
<NodeId
, Module
<'a
>>,
937 ast_transform_scopes
: FxHashMap
<ExpnId
, Module
<'a
>>,
938 unused_macros
: NodeMap
<Span
>,
939 proc_macro_stubs
: NodeSet
,
940 /// Traces collected during macro resolution and validated when it's complete.
941 single_segment_macro_resolutions
: Vec
<(Ident
, MacroKind
, ParentScope
<'a
>,
942 Option
<&'a NameBinding
<'a
>>)>,
943 multi_segment_macro_resolutions
: Vec
<(Vec
<Segment
>, Span
, MacroKind
, ParentScope
<'a
>,
945 builtin_attrs
: Vec
<(Ident
, ParentScope
<'a
>)>,
946 /// Some built-in derives mark items they are applied to so they are treated specially later.
947 /// Derive macros cannot modify the item themselves and have to store the markers in the global
948 /// context, so they attach the markers to derive container IDs using this resolver table.
949 /// FIXME: Find a way for `PartialEq` and `Eq` to emulate `#[structural_match]`
950 /// by marking the produced impls rather than the original items.
951 special_derives
: FxHashMap
<ExpnId
, SpecialDerives
>,
952 /// Parent scopes in which the macros were invoked.
953 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
954 invocation_parent_scopes
: FxHashMap
<ExpnId
, ParentScope
<'a
>>,
955 /// Legacy scopes *produced* by expanding the macro invocations,
956 /// include all the `macro_rules` items and other invocations generated by them.
957 output_legacy_scopes
: FxHashMap
<ExpnId
, LegacyScope
<'a
>>,
959 /// Avoid duplicated errors for "name already defined".
960 name_already_seen
: FxHashMap
<Name
, Span
>,
962 potentially_unused_imports
: Vec
<&'a ImportDirective
<'a
>>,
964 /// Table for mapping struct IDs into struct constructor IDs,
965 /// it's not used during normal resolution, only for better error reporting.
966 struct_constructors
: DefIdMap
<(Res
, ty
::Visibility
)>,
968 /// Features enabled for this crate.
969 active_features
: FxHashSet
<Name
>,
971 /// Stores enum visibilities to properly build a reduced graph
972 /// when visiting the correspondent variants.
973 variant_vis
: DefIdMap
<ty
::Visibility
>,
975 lint_buffer
: lint
::LintBuffer
,
978 /// Nothing really interesting here; it just provides memory for the rest of the crate.
980 pub struct ResolverArenas
<'a
> {
981 modules
: arena
::TypedArena
<ModuleData
<'a
>>,
982 local_modules
: RefCell
<Vec
<Module
<'a
>>>,
983 name_bindings
: arena
::TypedArena
<NameBinding
<'a
>>,
984 import_directives
: arena
::TypedArena
<ImportDirective
<'a
>>,
985 name_resolutions
: arena
::TypedArena
<RefCell
<NameResolution
<'a
>>>,
986 legacy_bindings
: arena
::TypedArena
<LegacyBinding
<'a
>>,
987 ast_paths
: arena
::TypedArena
<ast
::Path
>,
990 impl<'a
> ResolverArenas
<'a
> {
991 fn alloc_module(&'a
self, module
: ModuleData
<'a
>) -> Module
<'a
> {
992 let module
= self.modules
.alloc(module
);
993 if module
.def_id().map(|def_id
| def_id
.is_local()).unwrap_or(true) {
994 self.local_modules
.borrow_mut().push(module
);
998 fn local_modules(&'a
self) -> std
::cell
::Ref
<'a
, Vec
<Module
<'a
>>> {
999 self.local_modules
.borrow()
1001 fn alloc_name_binding(&'a
self, name_binding
: NameBinding
<'a
>) -> &'a NameBinding
<'a
> {
1002 self.name_bindings
.alloc(name_binding
)
1004 fn alloc_import_directive(&'a
self, import_directive
: ImportDirective
<'a
>)
1005 -> &'a ImportDirective
<'_
> {
1006 self.import_directives
.alloc(import_directive
)
1008 fn alloc_name_resolution(&'a
self) -> &'a RefCell
<NameResolution
<'a
>> {
1009 self.name_resolutions
.alloc(Default
::default())
1011 fn alloc_legacy_binding(&'a
self, binding
: LegacyBinding
<'a
>) -> &'a LegacyBinding
<'a
> {
1012 self.legacy_bindings
.alloc(binding
)
1014 fn alloc_ast_paths(&'a
self, paths
: &[ast
::Path
]) -> &'a
[ast
::Path
] {
1015 self.ast_paths
.alloc_from_iter(paths
.iter().cloned())
1019 impl<'a
> AsMut
<Resolver
<'a
>> for Resolver
<'a
> {
1020 fn as_mut(&mut self) -> &mut Resolver
<'a
> { self }
1023 impl<'a
, 'b
> DefIdTree
for &'a Resolver
<'b
> {
1024 fn parent(self, id
: DefId
) -> Option
<DefId
> {
1026 LOCAL_CRATE
=> self.definitions
.def_key(id
.index
).parent
,
1027 _
=> self.cstore().def_key(id
).parent
,
1028 }.map(|index
| DefId { index, ..id }
)
1032 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1033 /// the resolver is no longer needed as all the relevant information is inline.
1034 impl<'a
> hir
::lowering
::Resolver
for Resolver
<'a
> {
1035 fn cstore(&self) -> &dyn CrateStore
{
1039 fn resolve_str_path(
1042 crate_root
: Option
<Name
>,
1043 components
: &[Name
],
1045 ) -> (ast
::Path
, Res
) {
1046 let root
= if crate_root
.is_some() {
1051 let segments
= iter
::once(Ident
::with_dummy_span(root
))
1053 crate_root
.into_iter()
1054 .chain(components
.iter().cloned())
1055 .map(Ident
::with_dummy_span
)
1056 ).map(|i
| self.new_ast_path_segment(i
)).collect
::<Vec
<_
>>();
1058 let path
= ast
::Path
{
1063 let parent_scope
= &ParentScope
::module(self.graph_root
);
1064 let res
= match self.resolve_ast_path(&path
, ns
, parent_scope
) {
1066 Err((span
, error
)) => {
1067 self.report_error(span
, error
);
1074 fn get_partial_res(&mut self, id
: NodeId
) -> Option
<PartialRes
> {
1075 self.partial_res_map
.get(&id
).cloned()
1078 fn get_import_res(&mut self, id
: NodeId
) -> PerNS
<Option
<Res
>> {
1079 self.import_res_map
.get(&id
).cloned().unwrap_or_default()
1082 fn get_label_res(&mut self, id
: NodeId
) -> Option
<NodeId
> {
1083 self.label_res_map
.get(&id
).cloned()
1086 fn definitions(&mut self) -> &mut Definitions
{
1087 &mut self.definitions
1090 fn has_derives(&self, node_id
: NodeId
, derives
: SpecialDerives
) -> bool
{
1091 let def_id
= self.definitions
.local_def_id(node_id
);
1092 let expn_id
= self.definitions
.expansion_that_defined(def_id
.index
);
1093 self.has_derives(expn_id
, derives
)
1096 fn lint_buffer(&mut self) -> &mut lint
::LintBuffer
{
1097 &mut self.lint_buffer
1101 impl<'a
> Resolver
<'a
> {
1102 pub fn new(session
: &'a Session
,
1105 metadata_loader
: &'a MetadataLoaderDyn
,
1106 arenas
: &'a ResolverArenas
<'a
>)
1108 let root_def_id
= DefId
::local(CRATE_DEF_INDEX
);
1109 let root_module_kind
= ModuleKind
::Def(
1114 let graph_root
= arenas
.alloc_module(ModuleData
{
1115 no_implicit_prelude
: attr
::contains_name(&krate
.attrs
, sym
::no_implicit_prelude
),
1116 ..ModuleData
::new(None
, root_module_kind
, root_def_id
, ExpnId
::root(), krate
.span
)
1118 let empty_module_kind
= ModuleKind
::Def(
1123 let empty_module
= arenas
.alloc_module(ModuleData
{
1124 no_implicit_prelude
: true,
1133 let mut module_map
= FxHashMap
::default();
1134 module_map
.insert(DefId
::local(CRATE_DEF_INDEX
), graph_root
);
1136 let mut definitions
= Definitions
::default();
1137 definitions
.create_root_def(crate_name
, session
.local_crate_disambiguator());
1139 let mut extern_prelude
: FxHashMap
<Ident
, ExternPreludeEntry
<'_
>> =
1140 session
.opts
.externs
.iter().map(|kv
| (Ident
::from_str(kv
.0), Default
::default()))
1143 if !attr
::contains_name(&krate
.attrs
, sym
::no_core
) {
1144 extern_prelude
.insert(Ident
::with_dummy_span(sym
::core
), Default
::default());
1145 if !attr
::contains_name(&krate
.attrs
, sym
::no_std
) {
1146 extern_prelude
.insert(Ident
::with_dummy_span(sym
::std
), Default
::default());
1147 if session
.rust_2018() {
1148 extern_prelude
.insert(Ident
::with_dummy_span(sym
::meta
), Default
::default());
1153 let mut invocation_parent_scopes
= FxHashMap
::default();
1154 invocation_parent_scopes
.insert(ExpnId
::root(), ParentScope
::module(graph_root
));
1156 let mut macro_defs
= FxHashMap
::default();
1157 macro_defs
.insert(ExpnId
::root(), root_def_id
);
1159 let features
= session
.features_untracked();
1160 let non_macro_attr
=
1161 |mark_used
| Lrc
::new(SyntaxExtension
::non_macro_attr(mark_used
, session
.edition()));
1168 // The outermost module has def ID 0; this is not reflected in the
1174 has_self
: FxHashSet
::default(),
1175 field_names
: FxHashMap
::default(),
1177 determined_imports
: Vec
::new(),
1178 indeterminate_imports
: Vec
::new(),
1180 last_import_segment
: false,
1181 blacklisted_binding
: None
,
1183 primitive_type_table
: PrimitiveTypeTable
::new(),
1185 partial_res_map
: Default
::default(),
1186 import_res_map
: Default
::default(),
1187 label_res_map
: Default
::default(),
1188 extern_crate_map
: Default
::default(),
1189 export_map
: FxHashMap
::default(),
1190 trait_map
: Default
::default(),
1191 underscore_disambiguator
: 0,
1194 block_map
: Default
::default(),
1195 extern_module_map
: FxHashMap
::default(),
1196 binding_parent_modules
: FxHashMap
::default(),
1197 ast_transform_scopes
: FxHashMap
::default(),
1199 glob_map
: Default
::default(),
1201 used_imports
: FxHashSet
::default(),
1202 maybe_unused_trait_imports
: Default
::default(),
1203 maybe_unused_extern_crates
: Vec
::new(),
1205 privacy_errors
: Vec
::new(),
1206 ambiguity_errors
: Vec
::new(),
1207 use_injections
: Vec
::new(),
1208 macro_expanded_macro_export_errors
: BTreeSet
::new(),
1211 dummy_binding
: arenas
.alloc_name_binding(NameBinding
{
1212 kind
: NameBindingKind
::Res(Res
::Err
, false),
1214 expansion
: ExpnId
::root(),
1216 vis
: ty
::Visibility
::Public
,
1219 crate_loader
: CrateLoader
::new(session
, metadata_loader
, crate_name
),
1220 macro_names
: FxHashSet
::default(),
1221 builtin_macros
: Default
::default(),
1222 macro_use_prelude
: FxHashMap
::default(),
1223 all_macros
: FxHashMap
::default(),
1224 macro_map
: FxHashMap
::default(),
1225 dummy_ext_bang
: Lrc
::new(SyntaxExtension
::dummy_bang(session
.edition())),
1226 dummy_ext_derive
: Lrc
::new(SyntaxExtension
::dummy_derive(session
.edition())),
1227 non_macro_attrs
: [non_macro_attr(false), non_macro_attr(true)],
1228 invocation_parent_scopes
,
1229 output_legacy_scopes
: Default
::default(),
1231 local_macro_def_scopes
: FxHashMap
::default(),
1232 name_already_seen
: FxHashMap
::default(),
1233 potentially_unused_imports
: Vec
::new(),
1234 struct_constructors
: Default
::default(),
1235 unused_macros
: Default
::default(),
1236 proc_macro_stubs
: Default
::default(),
1237 single_segment_macro_resolutions
: Default
::default(),
1238 multi_segment_macro_resolutions
: Default
::default(),
1239 builtin_attrs
: Default
::default(),
1240 special_derives
: Default
::default(),
1242 features
.declared_lib_features
.iter().map(|(feat
, ..)| *feat
)
1243 .chain(features
.declared_lang_features
.iter().map(|(feat
, ..)| *feat
))
1245 variant_vis
: Default
::default(),
1246 lint_buffer
: lint
::LintBuffer
::default(),
1250 pub fn lint_buffer(&mut self) -> &mut lint
::LintBuffer
{
1251 &mut self.lint_buffer
1254 pub fn arenas() -> ResolverArenas
<'a
> {
1258 pub fn into_outputs(self) -> ResolverOutputs
{
1260 definitions
: self.definitions
,
1261 cstore
: Box
::new(self.crate_loader
.into_cstore()),
1262 extern_crate_map
: self.extern_crate_map
,
1263 export_map
: self.export_map
,
1264 trait_map
: self.trait_map
,
1265 glob_map
: self.glob_map
,
1266 maybe_unused_trait_imports
: self.maybe_unused_trait_imports
,
1267 maybe_unused_extern_crates
: self.maybe_unused_extern_crates
,
1268 extern_prelude
: self.extern_prelude
.iter().map(|(ident
, entry
)| {
1269 (ident
.name
, entry
.introduced_by_item
)
1274 pub fn clone_outputs(&self) -> ResolverOutputs
{
1276 definitions
: self.definitions
.clone(),
1277 cstore
: Box
::new(self.cstore().clone()),
1278 extern_crate_map
: self.extern_crate_map
.clone(),
1279 export_map
: self.export_map
.clone(),
1280 trait_map
: self.trait_map
.clone(),
1281 glob_map
: self.glob_map
.clone(),
1282 maybe_unused_trait_imports
: self.maybe_unused_trait_imports
.clone(),
1283 maybe_unused_extern_crates
: self.maybe_unused_extern_crates
.clone(),
1284 extern_prelude
: self.extern_prelude
.iter().map(|(ident
, entry
)| {
1285 (ident
.name
, entry
.introduced_by_item
)
1290 pub fn cstore(&self) -> &CStore
{
1291 self.crate_loader
.cstore()
1294 fn non_macro_attr(&self, mark_used
: bool
) -> Lrc
<SyntaxExtension
> {
1295 self.non_macro_attrs
[mark_used
as usize].clone()
1298 fn dummy_ext(&self, macro_kind
: MacroKind
) -> Lrc
<SyntaxExtension
> {
1300 MacroKind
::Bang
=> self.dummy_ext_bang
.clone(),
1301 MacroKind
::Derive
=> self.dummy_ext_derive
.clone(),
1302 MacroKind
::Attr
=> self.non_macro_attr(true),
1306 /// Runs the function on each namespace.
1307 fn per_ns
<F
: FnMut(&mut Self, Namespace
)>(&mut self, mut f
: F
) {
1313 fn is_builtin_macro(&mut self, res
: Res
) -> bool
{
1314 self.get_macro(res
).map_or(false, |ext
| ext
.is_builtin
)
1317 fn macro_def(&self, mut ctxt
: SyntaxContext
) -> DefId
{
1319 match self.macro_defs
.get(&ctxt
.outer_expn()) {
1320 Some(&def_id
) => return def_id
,
1321 None
=> ctxt
.remove_mark(),
1326 fn has_derives(&self, expn_id
: ExpnId
, markers
: SpecialDerives
) -> bool
{
1327 self.special_derives
.get(&expn_id
).map_or(false, |m
| m
.contains(markers
))
1330 /// Entry point to crate resolution.
1331 pub fn resolve_crate(&mut self, krate
: &Crate
) {
1333 self.session
.prof
.generic_activity("resolve_crate");
1335 ImportResolver { r: self }
.finalize_imports();
1336 self.finalize_macro_resolutions();
1338 self.late_resolve_crate(krate
);
1340 self.check_unused(krate
);
1341 self.report_errors(krate
);
1342 self.crate_loader
.postprocess(krate
);
1349 normal_ancestor_id
: DefId
,
1353 let module
= ModuleData
::new(Some(parent
), kind
, normal_ancestor_id
, expn_id
, span
);
1354 self.arenas
.alloc_module(module
)
1357 fn new_key(&mut self, ident
: Ident
, ns
: Namespace
) -> BindingKey
{
1358 let ident
= ident
.modern();
1359 let disambiguator
= if ident
.name
== kw
::Underscore
{
1360 self.underscore_disambiguator
+= 1;
1361 self.underscore_disambiguator
1365 BindingKey { ident, ns, disambiguator }
1368 fn resolutions(&mut self, module
: Module
<'a
>) -> &'a Resolutions
<'a
> {
1369 if module
.populate_on_access
.get() {
1370 module
.populate_on_access
.set(false);
1371 self.build_reduced_graph_external(module
);
1373 &module
.lazy_resolutions
1376 fn resolution(&mut self, module
: Module
<'a
>, key
: BindingKey
)
1377 -> &'a RefCell
<NameResolution
<'a
>> {
1378 *self.resolutions(module
).borrow_mut().entry(key
)
1379 .or_insert_with(|| self.arenas
.alloc_name_resolution())
1382 fn record_use(&mut self, ident
: Ident
, ns
: Namespace
,
1383 used_binding
: &'a NameBinding
<'a
>, is_lexical_scope
: bool
) {
1384 if let Some((b2
, kind
)) = used_binding
.ambiguity
{
1385 self.ambiguity_errors
.push(AmbiguityError
{
1386 kind
, ident
, b1
: used_binding
, b2
,
1387 misc1
: AmbiguityErrorMisc
::None
,
1388 misc2
: AmbiguityErrorMisc
::None
,
1391 if let NameBindingKind
::Import { directive, binding, ref used }
= used_binding
.kind
{
1392 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1393 // but not introduce it, as used if they are accessed from lexical scope.
1394 if is_lexical_scope
{
1395 if let Some(entry
) = self.extern_prelude
.get(&ident
.modern()) {
1396 if let Some(crate_item
) = entry
.extern_crate_item
{
1397 if ptr
::eq(used_binding
, crate_item
) && !entry
.introduced_by_item
{
1404 directive
.used
.set(true);
1405 self.used_imports
.insert((directive
.id
, ns
));
1406 self.add_to_glob_map(&directive
, ident
);
1407 self.record_use(ident
, ns
, binding
, false);
1412 fn add_to_glob_map(&mut self, directive
: &ImportDirective
<'_
>, ident
: Ident
) {
1413 if directive
.is_glob() {
1414 self.glob_map
.entry(directive
.id
).or_default().insert(ident
.name
);
1418 /// A generic scope visitor.
1419 /// Visits scopes in order to resolve some identifier in them or perform other actions.
1420 /// If the callback returns `Some` result, we stop visiting scopes and return it.
1423 scope_set
: ScopeSet
,
1424 parent_scope
: &ParentScope
<'a
>,
1426 mut visitor
: impl FnMut(&mut Self, Scope
<'a
>, /*use_prelude*/ bool
, Ident
) -> Option
<T
>,
1428 // General principles:
1429 // 1. Not controlled (user-defined) names should have higher priority than controlled names
1430 // built into the language or standard library. This way we can add new names into the
1431 // language or standard library without breaking user code.
1432 // 2. "Closed set" below means new names cannot appear after the current resolution attempt.
1433 // Places to search (in order of decreasing priority):
1435 // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet
1436 // (open set, not controlled).
1437 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1438 // (open, not controlled).
1439 // 3. Extern prelude (open, the open part is from macro expansions, not controlled).
1440 // 4. Tool modules (closed, controlled right now, but not in the future).
1441 // 5. Standard library prelude (de-facto closed, controlled).
1442 // 6. Language prelude (closed, controlled).
1444 // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet
1445 // (open set, not controlled).
1446 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1447 // (open, not controlled).
1448 // 3. Standard library prelude (de-facto closed, controlled).
1450 // 1-3. Derive helpers (open, not controlled). All ambiguities with other names
1451 // are currently reported as errors. They should be higher in priority than preludes
1452 // and probably even names in modules according to the "general principles" above. They
1453 // also should be subject to restricted shadowing because are effectively produced by
1454 // derives (you need to resolve the derive first to add helpers into scope), but they
1455 // should be available before the derive is expanded for compatibility.
1456 // It's mess in general, so we are being conservative for now.
1457 // 1-3. `macro_rules` (open, not controlled), loop through legacy scopes. Have higher
1458 // priority than prelude macros, but create ambiguities with macros in modules.
1459 // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1460 // (open, not controlled). Have higher priority than prelude macros, but create
1461 // ambiguities with `macro_rules`.
1462 // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled).
1463 // 4a. User-defined prelude from macro-use
1464 // (open, the open part is from macro expansions, not controlled).
1465 // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled).
1466 // 4c. Standard library prelude (de-facto closed, controlled).
1467 // 6. Language prelude: builtin attributes (closed, controlled).
1468 // 4-6. Legacy plugin helpers (open, not controlled). Similar to derive helpers,
1469 // but introduced by legacy plugins using `register_attribute`. Priority is somewhere
1470 // in prelude, not sure where exactly (creates ambiguities with any other prelude names).
1472 let rust_2015
= ident
.span
.rust_2015();
1473 let (ns
, is_absolute_path
) = match scope_set
{
1474 ScopeSet
::All(ns
, _
) => (ns
, false),
1475 ScopeSet
::AbsolutePath(ns
) => (ns
, true),
1476 ScopeSet
::Macro(_
) => (MacroNS
, false),
1478 // Jump out of trait or enum modules, they do not act as scopes.
1479 let module
= parent_scope
.module
.nearest_item_scope();
1480 let mut scope
= match ns
{
1481 _
if is_absolute_path
=> Scope
::CrateRoot
,
1482 TypeNS
| ValueNS
=> Scope
::Module(module
),
1483 MacroNS
=> Scope
::DeriveHelpers
,
1485 let mut ident
= ident
.modern();
1486 let mut use_prelude
= !module
.no_implicit_prelude
;
1489 let visit
= match scope
{
1490 Scope
::DeriveHelpers
=> true,
1491 Scope
::MacroRules(..) => true,
1492 Scope
::CrateRoot
=> true,
1493 Scope
::Module(..) => true,
1494 Scope
::MacroUsePrelude
=> use_prelude
|| rust_2015
,
1495 Scope
::BuiltinAttrs
=> true,
1496 Scope
::LegacyPluginHelpers
=> use_prelude
|| rust_2015
,
1497 Scope
::ExternPrelude
=> use_prelude
|| is_absolute_path
,
1498 Scope
::ToolPrelude
=> use_prelude
,
1499 Scope
::StdLibPrelude
=> use_prelude
|| ns
== MacroNS
,
1500 Scope
::BuiltinTypes
=> true,
1504 if let break_result @
Some(..) = visitor(self, scope
, use_prelude
, ident
) {
1505 return break_result
;
1509 scope
= match scope
{
1510 Scope
::DeriveHelpers
=>
1511 Scope
::MacroRules(parent_scope
.legacy
),
1512 Scope
::MacroRules(legacy_scope
) => match legacy_scope
{
1513 LegacyScope
::Binding(binding
) => Scope
::MacroRules(
1514 binding
.parent_legacy_scope
1516 LegacyScope
::Invocation(invoc_id
) => Scope
::MacroRules(
1517 self.output_legacy_scopes
.get(&invoc_id
).cloned()
1518 .unwrap_or(self.invocation_parent_scopes
[&invoc_id
].legacy
)
1520 LegacyScope
::Empty
=> Scope
::Module(module
),
1522 Scope
::CrateRoot
=> match ns
{
1524 ident
.span
.adjust(ExpnId
::root());
1525 Scope
::ExternPrelude
1527 ValueNS
| MacroNS
=> break,
1529 Scope
::Module(module
) => {
1530 use_prelude
= !module
.no_implicit_prelude
;
1531 match self.hygienic_lexical_parent(module
, &mut ident
.span
) {
1532 Some(parent_module
) => Scope
::Module(parent_module
),
1534 ident
.span
.adjust(ExpnId
::root());
1536 TypeNS
=> Scope
::ExternPrelude
,
1537 ValueNS
=> Scope
::StdLibPrelude
,
1538 MacroNS
=> Scope
::MacroUsePrelude
,
1543 Scope
::MacroUsePrelude
=> Scope
::StdLibPrelude
,
1544 Scope
::BuiltinAttrs
=> Scope
::LegacyPluginHelpers
,
1545 Scope
::LegacyPluginHelpers
=> break, // nowhere else to search
1546 Scope
::ExternPrelude
if is_absolute_path
=> break,
1547 Scope
::ExternPrelude
=> Scope
::ToolPrelude
,
1548 Scope
::ToolPrelude
=> Scope
::StdLibPrelude
,
1549 Scope
::StdLibPrelude
=> match ns
{
1550 TypeNS
=> Scope
::BuiltinTypes
,
1551 ValueNS
=> break, // nowhere else to search
1552 MacroNS
=> Scope
::BuiltinAttrs
,
1554 Scope
::BuiltinTypes
=> break, // nowhere else to search
1561 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1562 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1563 /// `ident` in the first scope that defines it (or None if no scopes define it).
1565 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1566 /// the items are defined in the block. For example,
1569 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1572 /// g(); // This resolves to the local variable `g` since it shadows the item.
1576 /// Invariant: This must only be called during main resolution, not during
1577 /// import resolution.
1578 fn resolve_ident_in_lexical_scope(&mut self,
1581 parent_scope
: &ParentScope
<'a
>,
1582 record_used_id
: Option
<NodeId
>,
1585 -> Option
<LexicalScopeBinding
<'a
>> {
1586 assert
!(ns
== TypeNS
|| ns
== ValueNS
);
1587 if ident
.name
== kw
::Invalid
{
1588 return Some(LexicalScopeBinding
::Res(Res
::Err
));
1590 let (general_span
, modern_span
) = if ident
.name
== kw
::SelfUpper
{
1591 // FIXME(jseyfried) improve `Self` hygiene
1592 let empty_span
= ident
.span
.with_ctxt(SyntaxContext
::root());
1593 (empty_span
, empty_span
)
1594 } else if ns
== TypeNS
{
1595 let modern_span
= ident
.span
.modern();
1596 (modern_span
, modern_span
)
1598 (ident
.span
.modern_and_legacy(), ident
.span
.modern())
1600 ident
.span
= general_span
;
1601 let modern_ident
= Ident { span: modern_span, ..ident }
;
1603 // Walk backwards up the ribs in scope.
1604 let record_used
= record_used_id
.is_some();
1605 let mut module
= self.graph_root
;
1606 for i
in (0 .. ribs
.len()).rev() {
1607 debug
!("walk rib\n{:?}", ribs
[i
].bindings
);
1608 // Use the rib kind to determine whether we are resolving parameters
1609 // (modern hygiene) or local variables (legacy hygiene).
1610 let rib_ident
= if ribs
[i
].kind
.contains_params() {
1615 if let Some(res
) = ribs
[i
].bindings
.get(&rib_ident
).cloned() {
1616 // The ident resolves to a type parameter or local variable.
1617 return Some(LexicalScopeBinding
::Res(
1618 self.validate_res_from_ribs(i
, rib_ident
, res
, record_used
, path_span
, ribs
),
1622 module
= match ribs
[i
].kind
{
1623 ModuleRibKind(module
) => module
,
1624 MacroDefinition(def
) if def
== self.macro_def(ident
.span
.ctxt()) => {
1625 // If an invocation of this macro created `ident`, give up on `ident`
1626 // and switch to `ident`'s source from the macro definition.
1627 ident
.span
.remove_mark();
1634 let item
= self.resolve_ident_in_module_unadjusted(
1635 ModuleOrUniformRoot
::Module(module
),
1642 if let Ok(binding
) = item
{
1643 // The ident resolves to an item.
1644 return Some(LexicalScopeBinding
::Item(binding
));
1648 ModuleKind
::Block(..) => {}
, // We can see through blocks
1653 ident
= modern_ident
;
1654 let mut poisoned
= None
;
1656 let opt_module
= if let Some(node_id
) = record_used_id
{
1657 self.hygienic_lexical_parent_with_compatibility_fallback(module
, &mut ident
.span
,
1658 node_id
, &mut poisoned
)
1660 self.hygienic_lexical_parent(module
, &mut ident
.span
)
1662 module
= unwrap_or
!(opt_module
, break);
1663 let adjusted_parent_scope
= &ParentScope { module, ..*parent_scope }
;
1664 let result
= self.resolve_ident_in_module_unadjusted(
1665 ModuleOrUniformRoot
::Module(module
),
1668 adjusted_parent_scope
,
1675 if let Some(node_id
) = poisoned
{
1676 self.lint_buffer
.buffer_lint_with_diagnostic(
1677 lint
::builtin
::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK
,
1678 node_id
, ident
.span
,
1679 &format
!("cannot find {} `{}` in this scope", ns
.descr(), ident
),
1680 lint
::builtin
::BuiltinLintDiagnostics
::
1681 ProcMacroDeriveResolutionFallback(ident
.span
),
1684 return Some(LexicalScopeBinding
::Item(binding
))
1686 Err(Determined
) => continue,
1687 Err(Undetermined
) =>
1688 span_bug
!(ident
.span
, "undetermined resolution during main resolution pass"),
1692 if !module
.no_implicit_prelude
{
1693 ident
.span
.adjust(ExpnId
::root());
1695 if let Some(binding
) = self.extern_prelude_get(ident
, !record_used
) {
1696 return Some(LexicalScopeBinding
::Item(binding
));
1699 if ns
== TypeNS
&& KNOWN_TOOLS
.contains(&ident
.name
) {
1700 let binding
= (Res
::ToolMod
, ty
::Visibility
::Public
,
1701 DUMMY_SP
, ExpnId
::root()).to_name_binding(self.arenas
);
1702 return Some(LexicalScopeBinding
::Item(binding
));
1704 if let Some(prelude
) = self.prelude
{
1705 if let Ok(binding
) = self.resolve_ident_in_module_unadjusted(
1706 ModuleOrUniformRoot
::Module(prelude
),
1713 return Some(LexicalScopeBinding
::Item(binding
));
1721 fn hygienic_lexical_parent(&mut self, module
: Module
<'a
>, span
: &mut Span
)
1722 -> Option
<Module
<'a
>> {
1723 if !module
.expansion
.outer_expn_is_descendant_of(span
.ctxt()) {
1724 return Some(self.macro_def_scope(span
.remove_mark()));
1727 if let ModuleKind
::Block(..) = module
.kind
{
1728 return Some(module
.parent
.unwrap().nearest_item_scope());
1734 fn hygienic_lexical_parent_with_compatibility_fallback(&mut self, module
: Module
<'a
>,
1735 span
: &mut Span
, node_id
: NodeId
,
1736 poisoned
: &mut Option
<NodeId
>)
1737 -> Option
<Module
<'a
>> {
1738 if let module @
Some(..) = self.hygienic_lexical_parent(module
, span
) {
1742 // We need to support the next case under a deprecation warning
1745 // ---- begin: this comes from a proc macro derive
1746 // mod implementation_details {
1747 // // Note that `MyStruct` is not in scope here.
1748 // impl SomeTrait for MyStruct { ... }
1752 // So we have to fall back to the module's parent during lexical resolution in this case.
1753 if let Some(parent
) = module
.parent
{
1754 // Inner module is inside the macro, parent module is outside of the macro.
1755 if module
.expansion
!= parent
.expansion
&&
1756 module
.expansion
.is_descendant_of(parent
.expansion
) {
1757 // The macro is a proc macro derive
1758 if let Some(&def_id
) = self.macro_defs
.get(&module
.expansion
) {
1759 if let Some(ext
) = self.get_macro_by_def_id(def_id
) {
1760 if !ext
.is_builtin
&& ext
.macro_kind() == MacroKind
::Derive
{
1761 if parent
.expansion
.outer_expn_is_descendant_of(span
.ctxt()) {
1762 *poisoned
= Some(node_id
);
1763 return module
.parent
;
1774 fn resolve_ident_in_module(
1776 module
: ModuleOrUniformRoot
<'a
>,
1779 parent_scope
: &ParentScope
<'a
>,
1782 ) -> Result
<&'a NameBinding
<'a
>, Determinacy
> {
1783 self.resolve_ident_in_module_ext(
1784 module
, ident
, ns
, parent_scope
, record_used
, path_span
1785 ).map_err(|(determinacy
, _
)| determinacy
)
1788 fn resolve_ident_in_module_ext(
1790 module
: ModuleOrUniformRoot
<'a
>,
1793 parent_scope
: &ParentScope
<'a
>,
1796 ) -> Result
<&'a NameBinding
<'a
>, (Determinacy
, Weak
)> {
1797 let tmp_parent_scope
;
1798 let mut adjusted_parent_scope
= parent_scope
;
1800 ModuleOrUniformRoot
::Module(m
) => {
1801 if let Some(def
) = ident
.span
.modernize_and_adjust(m
.expansion
) {
1803 ParentScope { module: self.macro_def_scope(def), ..*parent_scope }
;
1804 adjusted_parent_scope
= &tmp_parent_scope
;
1807 ModuleOrUniformRoot
::ExternPrelude
=> {
1808 ident
.span
.modernize_and_adjust(ExpnId
::root());
1810 ModuleOrUniformRoot
::CrateRootAndExternPrelude
|
1811 ModuleOrUniformRoot
::CurrentScope
=> {
1815 let result
= self.resolve_ident_in_module_unadjusted_ext(
1816 module
, ident
, ns
, adjusted_parent_scope
, false, record_used
, path_span
,
1821 fn resolve_crate_root(&mut self, ident
: Ident
) -> Module
<'a
> {
1822 let mut ctxt
= ident
.span
.ctxt();
1823 let mark
= if ident
.name
== kw
::DollarCrate
{
1824 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
1825 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
1826 // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
1827 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
1828 // definitions actually produced by `macro` and `macro` definitions produced by
1829 // `macro_rules!`, but at least such configurations are not stable yet.
1830 ctxt
= ctxt
.modern_and_legacy();
1831 let mut iter
= ctxt
.marks().into_iter().rev().peekable();
1832 let mut result
= None
;
1833 // Find the last modern mark from the end if it exists.
1834 while let Some(&(mark
, transparency
)) = iter
.peek() {
1835 if transparency
== Transparency
::Opaque
{
1836 result
= Some(mark
);
1842 // Then find the last legacy mark from the end if it exists.
1843 for (mark
, transparency
) in iter
{
1844 if transparency
== Transparency
::SemiTransparent
{
1845 result
= Some(mark
);
1852 ctxt
= ctxt
.modern();
1853 ctxt
.adjust(ExpnId
::root())
1855 let module
= match mark
{
1856 Some(def
) => self.macro_def_scope(def
),
1857 None
=> return self.graph_root
,
1859 self.get_module(DefId { index: CRATE_DEF_INDEX, ..module.normal_ancestor_id }
)
1862 fn resolve_self(&mut self, ctxt
: &mut SyntaxContext
, module
: Module
<'a
>) -> Module
<'a
> {
1863 let mut module
= self.get_module(module
.normal_ancestor_id
);
1864 while module
.span
.ctxt().modern() != *ctxt
{
1865 let parent
= module
.parent
.unwrap_or_else(|| self.macro_def_scope(ctxt
.remove_mark()));
1866 module
= self.get_module(parent
.normal_ancestor_id
);
1874 opt_ns
: Option
<Namespace
>, // `None` indicates a module path in import
1875 parent_scope
: &ParentScope
<'a
>,
1878 crate_lint
: CrateLint
,
1879 ) -> PathResult
<'a
> {
1880 self.resolve_path_with_ribs(
1881 path
, opt_ns
, parent_scope
, record_used
, path_span
, crate_lint
, None
1885 fn resolve_path_with_ribs(
1888 opt_ns
: Option
<Namespace
>, // `None` indicates a module path in import
1889 parent_scope
: &ParentScope
<'a
>,
1892 crate_lint
: CrateLint
,
1893 ribs
: Option
<&PerNS
<Vec
<Rib
<'a
>>>>,
1894 ) -> PathResult
<'a
> {
1895 let mut module
= None
;
1896 let mut allow_super
= true;
1897 let mut second_binding
= None
;
1900 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
1901 path_span={:?}, crate_lint={:?})",
1909 for (i
, &Segment { ident, id }
) in path
.iter().enumerate() {
1910 debug
!("resolve_path ident {} {:?} {:?}", i
, ident
, id
);
1911 let record_segment_res
= |this
: &mut Self, res
| {
1913 if let Some(id
) = id
{
1914 if !this
.partial_res_map
.contains_key(&id
) {
1915 assert
!(id
!= ast
::DUMMY_NODE_ID
, "Trying to resolve dummy id");
1916 this
.record_partial_res(id
, PartialRes
::new(res
));
1922 let is_last
= i
== path
.len() - 1;
1923 let ns
= if is_last { opt_ns.unwrap_or(TypeNS) }
else { TypeNS }
;
1924 let name
= ident
.name
;
1926 allow_super
&= ns
== TypeNS
&&
1927 (name
== kw
::SelfLower
||
1931 if allow_super
&& name
== kw
::Super
{
1932 let mut ctxt
= ident
.span
.ctxt().modern();
1933 let self_module
= match i
{
1934 0 => Some(self.resolve_self(&mut ctxt
, parent_scope
.module
)),
1936 Some(ModuleOrUniformRoot
::Module(module
)) => Some(module
),
1940 if let Some(self_module
) = self_module
{
1941 if let Some(parent
) = self_module
.parent
{
1942 module
= Some(ModuleOrUniformRoot
::Module(
1943 self.resolve_self(&mut ctxt
, parent
)));
1947 let msg
= "there are too many initial `super`s.".to_string();
1948 return PathResult
::Failed
{
1952 is_error_from_last_segment
: false,
1956 if name
== kw
::SelfLower
{
1957 let mut ctxt
= ident
.span
.ctxt().modern();
1958 module
= Some(ModuleOrUniformRoot
::Module(
1959 self.resolve_self(&mut ctxt
, parent_scope
.module
)));
1962 if name
== kw
::PathRoot
&& ident
.span
.rust_2018() {
1963 module
= Some(ModuleOrUniformRoot
::ExternPrelude
);
1966 if name
== kw
::PathRoot
&&
1967 ident
.span
.rust_2015() && self.session
.rust_2018() {
1968 // `::a::b` from 2015 macro on 2018 global edition
1969 module
= Some(ModuleOrUniformRoot
::CrateRootAndExternPrelude
);
1972 if name
== kw
::PathRoot
||
1973 name
== kw
::Crate
||
1974 name
== kw
::DollarCrate
{
1975 // `::a::b`, `crate::a::b` or `$crate::a::b`
1976 module
= Some(ModuleOrUniformRoot
::Module(
1977 self.resolve_crate_root(ident
)));
1983 // Report special messages for path segment keywords in wrong positions.
1984 if ident
.is_path_segment_keyword() && i
!= 0 {
1985 let name_str
= if name
== kw
::PathRoot
{
1986 "crate root".to_string()
1988 format
!("`{}`", name
)
1990 let label
= if i
== 1 && path
[0].ident
.name
== kw
::PathRoot
{
1991 format
!("global paths cannot start with {}", name_str
)
1993 format
!("{} in paths can only be used in start position", name_str
)
1995 return PathResult
::Failed
{
1999 is_error_from_last_segment
: false,
2003 let binding
= if let Some(module
) = module
{
2004 self.resolve_ident_in_module(
2005 module
, ident
, ns
, parent_scope
, record_used
, path_span
2007 } else if ribs
.is_none() || opt_ns
.is_none() || opt_ns
== Some(MacroNS
) {
2008 let scopes
= ScopeSet
::All(ns
, opt_ns
.is_none());
2009 self.early_resolve_ident_in_lexical_scope(ident
, scopes
, parent_scope
, record_used
,
2010 record_used
, path_span
)
2012 let record_used_id
=
2013 if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) }
else { None }
;
2014 match self.resolve_ident_in_lexical_scope(
2015 ident
, ns
, parent_scope
, record_used_id
, path_span
, &ribs
.unwrap()[ns
]
2017 // we found a locally-imported or available item/module
2018 Some(LexicalScopeBinding
::Item(binding
)) => Ok(binding
),
2019 // we found a local variable or type param
2020 Some(LexicalScopeBinding
::Res(res
))
2021 if opt_ns
== Some(TypeNS
) || opt_ns
== Some(ValueNS
) => {
2022 record_segment_res(self, res
);
2023 return PathResult
::NonModule(PartialRes
::with_unresolved_segments(
2027 _
=> Err(Determinacy
::determined(record_used
)),
2034 second_binding
= Some(binding
);
2036 let res
= binding
.res();
2037 let maybe_assoc
= opt_ns
!= Some(MacroNS
) && PathSource
::Type
.is_expected(res
);
2038 if let Some(next_module
) = binding
.module() {
2039 module
= Some(ModuleOrUniformRoot
::Module(next_module
));
2040 record_segment_res(self, res
);
2041 } else if res
== Res
::ToolMod
&& i
+ 1 != path
.len() {
2042 if binding
.is_import() {
2043 self.session
.struct_span_err(
2044 ident
.span
, "cannot use a tool module through an import"
2046 binding
.span
, "the tool module imported here"
2049 let res
= Res
::NonMacroAttr(NonMacroAttrKind
::Tool
);
2050 return PathResult
::NonModule(PartialRes
::new(res
));
2051 } else if res
== Res
::Err
{
2052 return PathResult
::NonModule(PartialRes
::new(Res
::Err
));
2053 } else if opt_ns
.is_some() && (is_last
|| maybe_assoc
) {
2054 self.lint_if_path_starts_with_module(
2060 return PathResult
::NonModule(PartialRes
::with_unresolved_segments(
2061 res
, path
.len() - i
- 1
2064 let label
= format
!(
2065 "`{}` is {} {}, not a module",
2071 return PathResult
::Failed
{
2075 is_error_from_last_segment
: is_last
,
2079 Err(Undetermined
) => return PathResult
::Indeterminate
,
2080 Err(Determined
) => {
2081 if let Some(ModuleOrUniformRoot
::Module(module
)) = module
{
2082 if opt_ns
.is_some() && !module
.is_normal() {
2083 return PathResult
::NonModule(PartialRes
::with_unresolved_segments(
2084 module
.res().unwrap(), path
.len() - i
2088 let module_res
= match module
{
2089 Some(ModuleOrUniformRoot
::Module(module
)) => module
.res(),
2092 let (label
, suggestion
) = if module_res
== self.graph_root
.res() {
2093 let is_mod
= |res
| {
2094 match res { Res::Def(DefKind::Mod, _) => true, _ => false }
2096 let mut candidates
=
2097 self.lookup_import_candidates(ident
, TypeNS
, is_mod
);
2098 candidates
.sort_by_cached_key(|c
| {
2099 (c
.path
.segments
.len(), pprust
::path_to_string(&c
.path
))
2101 if let Some(candidate
) = candidates
.get(0) {
2103 String
::from("unresolved import"),
2105 vec
![(ident
.span
, pprust
::path_to_string(&candidate
.path
))],
2106 String
::from("a similar path exists"),
2107 Applicability
::MaybeIncorrect
,
2110 } else if !ident
.is_reserved() {
2111 (format
!("maybe a missing crate `{}`?", ident
), None
)
2113 // the parser will already have complained about the keyword being used
2114 return PathResult
::NonModule(PartialRes
::new(Res
::Err
));
2117 (format
!("use of undeclared type or module `{}`", ident
), None
)
2119 (format
!("could not find `{}` in `{}`", ident
, path
[i
- 1].ident
), None
)
2121 return PathResult
::Failed
{
2125 is_error_from_last_segment
: is_last
,
2131 self.lint_if_path_starts_with_module(crate_lint
, path
, path_span
, second_binding
);
2133 PathResult
::Module(match module
{
2134 Some(module
) => module
,
2135 None
if path
.is_empty() => ModuleOrUniformRoot
::CurrentScope
,
2136 _
=> span_bug
!(path_span
, "resolve_path: non-empty path `{:?}` has no module", path
),
2140 fn lint_if_path_starts_with_module(
2142 crate_lint
: CrateLint
,
2145 second_binding
: Option
<&NameBinding
<'_
>>,
2147 let (diag_id
, diag_span
) = match crate_lint
{
2148 CrateLint
::No
=> return,
2149 CrateLint
::SimplePath(id
) => (id
, path_span
),
2150 CrateLint
::UsePath { root_id, root_span }
=> (root_id
, root_span
),
2151 CrateLint
::QPathTrait { qpath_id, qpath_span }
=> (qpath_id
, qpath_span
),
2154 let first_name
= match path
.get(0) {
2155 // In the 2018 edition this lint is a hard error, so nothing to do
2156 Some(seg
) if seg
.ident
.span
.rust_2015() && self.session
.rust_2015() => seg
.ident
.name
,
2160 // We're only interested in `use` paths which should start with
2161 // `{{root}}` currently.
2162 if first_name
!= kw
::PathRoot
{
2167 // If this import looks like `crate::...` it's already good
2168 Some(Segment { ident, .. }
) if ident
.name
== kw
::Crate
=> return,
2169 // Otherwise go below to see if it's an extern crate
2171 // If the path has length one (and it's `PathRoot` most likely)
2172 // then we don't know whether we're gonna be importing a crate or an
2173 // item in our crate. Defer this lint to elsewhere
2177 // If the first element of our path was actually resolved to an
2178 // `ExternCrate` (also used for `crate::...`) then no need to issue a
2179 // warning, this looks all good!
2180 if let Some(binding
) = second_binding
{
2181 if let NameBindingKind
::Import { directive: d, .. }
= binding
.kind
{
2182 // Careful: we still want to rewrite paths from
2183 // renamed extern crates.
2184 if let ImportDirectiveSubclass
::ExternCrate { source: None, .. }
= d
.subclass
{
2190 let diag
= lint
::builtin
::BuiltinLintDiagnostics
2191 ::AbsPathWithModule(diag_span
);
2192 self.lint_buffer
.buffer_lint_with_diagnostic(
2193 lint
::builtin
::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE
,
2195 "absolute paths must start with `self`, `super`, \
2196 `crate`, or an external crate name in the 2018 edition",
2200 // Validate a local resolution (from ribs).
2201 fn validate_res_from_ribs(
2208 all_ribs
: &[Rib
<'a
>],
2210 debug
!("validate_res_from_ribs({:?})", res
);
2211 let ribs
= &all_ribs
[rib_index
+ 1..];
2213 // An invalid forward use of a type parameter from a previous default.
2214 if let ForwardTyParamBanRibKind
= all_ribs
[rib_index
].kind
{
2216 let res_error
= if rib_ident
.name
== kw
::SelfUpper
{
2217 ResolutionError
::SelfInTyParamDefault
2219 ResolutionError
::ForwardDeclaredTyParam
2221 self.report_error(span
, res_error
);
2223 assert_eq
!(res
, Res
::Err
);
2229 use ResolutionError
::*;
2230 let mut res_err
= None
;
2234 NormalRibKind
| ModuleRibKind(..) | MacroDefinition(..) |
2235 ForwardTyParamBanRibKind
=> {
2236 // Nothing to do. Continue.
2238 ItemRibKind(_
) | FnItemRibKind
| AssocItemRibKind
=> {
2239 // This was an attempt to access an upvar inside a
2240 // named function item. This is not allowed, so we
2243 // We don't immediately trigger a resolve error, because
2244 // we want certain other resolution errors (namely those
2245 // emitted for `ConstantItemRibKind` below) to take
2247 res_err
= Some(CannotCaptureDynamicEnvironmentInFnItem
);
2250 ConstantItemRibKind
=> {
2251 // Still doesn't deal with upvars
2253 self.report_error(span
, AttemptToUseNonConstantValueInConstant
);
2259 if let Some(res_err
) = res_err
{
2260 self.report_error(span
, res_err
);
2264 Res
::Def(DefKind
::TyParam
, _
) | Res
::SelfTy(..) => {
2266 let has_generic_params
= match rib
.kind
{
2267 NormalRibKind
| AssocItemRibKind
|
2268 ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind
|
2269 ConstantItemRibKind
=> {
2270 // Nothing to do. Continue.
2273 // This was an attempt to use a type parameter outside its scope.
2274 ItemRibKind(has_generic_params
) => has_generic_params
,
2275 FnItemRibKind
=> HasGenericParams
::Yes
,
2279 self.report_error(span
, ResolutionError
::GenericParamsFromOuterFunction(
2280 res
, has_generic_params
));
2285 Res
::Def(DefKind
::ConstParam
, _
) => {
2286 let mut ribs
= ribs
.iter().peekable();
2287 if let Some(Rib { kind: FnItemRibKind, .. }
) = ribs
.peek() {
2288 // When declaring const parameters inside function signatures, the first rib
2289 // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
2290 // (spuriously) conflicting with the const param.
2294 let has_generic_params
= match rib
.kind
{
2295 ItemRibKind(has_generic_params
) => has_generic_params
,
2296 FnItemRibKind
=> HasGenericParams
::Yes
,
2300 // This was an attempt to use a const parameter outside its scope.
2302 self.report_error(span
, ResolutionError
::GenericParamsFromOuterFunction(
2303 res
, has_generic_params
));
2313 fn record_partial_res(&mut self, node_id
: NodeId
, resolution
: PartialRes
) {
2314 debug
!("(recording res) recording {:?} for {}", resolution
, node_id
);
2315 if let Some(prev_res
) = self.partial_res_map
.insert(node_id
, resolution
) {
2316 panic
!("path resolved multiple times ({:?} before, {:?} now)", prev_res
, resolution
);
2320 fn is_accessible_from(&self, vis
: ty
::Visibility
, module
: Module
<'a
>) -> bool
{
2321 vis
.is_accessible_from(module
.normal_ancestor_id
, self)
2324 fn set_binding_parent_module(&mut self, binding
: &'a NameBinding
<'a
>, module
: Module
<'a
>) {
2325 if let Some(old_module
) = self.binding_parent_modules
.insert(PtrKey(binding
), module
) {
2326 if !ptr
::eq(module
, old_module
) {
2327 span_bug
!(binding
.span
, "parent module is reset for binding");
2332 fn disambiguate_legacy_vs_modern(
2334 legacy
: &'a NameBinding
<'a
>,
2335 modern
: &'a NameBinding
<'a
>,
2337 // Some non-controversial subset of ambiguities "modern macro name" vs "macro_rules"
2338 // is disambiguated to mitigate regressions from macro modularization.
2339 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
2340 match (self.binding_parent_modules
.get(&PtrKey(legacy
)),
2341 self.binding_parent_modules
.get(&PtrKey(modern
))) {
2342 (Some(legacy
), Some(modern
)) =>
2343 legacy
.normal_ancestor_id
== modern
.normal_ancestor_id
&&
2344 modern
.is_ancestor_of(legacy
),
2349 fn binding_description(&self, b
: &NameBinding
<'_
>, ident
: Ident
, from_prelude
: bool
) -> String
{
2351 if b
.span
.is_dummy() {
2352 let add_built_in
= match b
.res() {
2353 // These already contain the "built-in" prefix or look bad with it.
2354 Res
::NonMacroAttr(..) | Res
::PrimTy(..) | Res
::ToolMod
=> false,
2357 let (built_in
, from
) = if from_prelude
{
2358 ("", " from prelude")
2359 } else if b
.is_extern_crate() && !b
.is_import() &&
2360 self.session
.opts
.externs
.get(&ident
.as_str()).is_some() {
2361 ("", " passed with `--extern`")
2362 } else if add_built_in
{
2368 let article
= if built_in
.is_empty() { res.article() }
else { "a" }
;
2369 format
!("{a}{built_in} {thing}{from}",
2370 a
= article
, thing
= res
.descr(), built_in
= built_in
, from
= from
)
2372 let introduced
= if b
.is_import() { "imported" }
else { "defined" }
;
2373 format
!("the {thing} {introduced} here",
2374 thing
= res
.descr(), introduced
= introduced
)
2378 fn report_ambiguity_error(&self, ambiguity_error
: &AmbiguityError
<'_
>) {
2379 let AmbiguityError { kind, ident, b1, b2, misc1, misc2 }
= *ambiguity_error
;
2380 let (b1
, b2
, misc1
, misc2
, swapped
) = if b2
.span
.is_dummy() && !b1
.span
.is_dummy() {
2381 // We have to print the span-less alternative first, otherwise formatting looks bad.
2382 (b2
, b1
, misc2
, misc1
, true)
2384 (b1
, b2
, misc1
, misc2
, false)
2387 let mut err
= struct_span_err
!(self.session
, ident
.span
, E0659
,
2388 "`{ident}` is ambiguous ({why})",
2389 ident
= ident
, why
= kind
.descr());
2390 err
.span_label(ident
.span
, "ambiguous name");
2392 let mut could_refer_to
= |b
: &NameBinding
<'_
>, misc
: AmbiguityErrorMisc
, also
: &str| {
2393 let what
= self.binding_description(b
, ident
, misc
== AmbiguityErrorMisc
::FromPrelude
);
2394 let note_msg
= format
!("`{ident}` could{also} refer to {what}",
2395 ident
= ident
, also
= also
, what
= what
);
2397 let thing
= b
.res().descr();
2398 let mut help_msgs
= Vec
::new();
2399 if b
.is_glob_import() && (kind
== AmbiguityKind
::GlobVsGlob
||
2400 kind
== AmbiguityKind
::GlobVsExpanded
||
2401 kind
== AmbiguityKind
::GlobVsOuter
&&
2402 swapped
!= also
.is_empty()) {
2403 help_msgs
.push(format
!("consider adding an explicit import of \
2404 `{ident}` to disambiguate", ident
= ident
))
2406 if b
.is_extern_crate() && ident
.span
.rust_2018() {
2407 help_msgs
.push(format
!(
2408 "use `::{ident}` to refer to this {thing} unambiguously",
2409 ident
= ident
, thing
= thing
,
2412 if misc
== AmbiguityErrorMisc
::SuggestCrate
{
2413 help_msgs
.push(format
!(
2414 "use `crate::{ident}` to refer to this {thing} unambiguously",
2415 ident
= ident
, thing
= thing
,
2417 } else if misc
== AmbiguityErrorMisc
::SuggestSelf
{
2418 help_msgs
.push(format
!(
2419 "use `self::{ident}` to refer to this {thing} unambiguously",
2420 ident
= ident
, thing
= thing
,
2424 err
.span_note(b
.span
, ¬e_msg
);
2425 for (i
, help_msg
) in help_msgs
.iter().enumerate() {
2426 let or
= if i
== 0 { "" }
else { "or " }
;
2427 err
.help(&format
!("{}{}", or
, help_msg
));
2431 could_refer_to(b1
, misc1
, "");
2432 could_refer_to(b2
, misc2
, " also");
2436 fn report_errors(&mut self, krate
: &Crate
) {
2437 self.report_with_use_injections(krate
);
2439 for &(span_use
, span_def
) in &self.macro_expanded_macro_export_errors
{
2440 let msg
= "macro-expanded `macro_export` macros from the current crate \
2441 cannot be referred to by absolute paths";
2442 self.lint_buffer
.buffer_lint_with_diagnostic(
2443 lint
::builtin
::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS
,
2444 CRATE_NODE_ID
, span_use
, msg
,
2445 lint
::builtin
::BuiltinLintDiagnostics
::
2446 MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def
),
2450 for ambiguity_error
in &self.ambiguity_errors
{
2451 self.report_ambiguity_error(ambiguity_error
);
2454 let mut reported_spans
= FxHashSet
::default();
2455 for &PrivacyError(dedup_span
, ident
, binding
) in &self.privacy_errors
{
2456 if reported_spans
.insert(dedup_span
) {
2457 let session
= &self.session
;
2458 let mk_struct_span_error
= |is_constructor
| {
2463 "{}{} `{}` is private",
2464 binding
.res().descr(),
2465 if is_constructor { " constructor"}
else { "" }
,
2470 let mut err
= if let NameBindingKind
::Res(
2471 Res
::Def(DefKind
::Ctor(CtorOf
::Struct
, CtorKind
::Fn
), ctor_def_id
), _
2473 let def_id
= (&*self).parent(ctor_def_id
).expect("no parent for a constructor");
2474 if let Some(fields
) = self.field_names
.get(&def_id
) {
2475 let mut err
= mk_struct_span_error(true);
2476 let first_field
= fields
.first().expect("empty field list in the map");
2478 fields
.iter().fold(first_field
.span
, |acc
, field
| acc
.to(field
.span
)),
2479 "a constructor is private if any of the fields is private",
2483 mk_struct_span_error(false)
2486 mk_struct_span_error(false)
2494 fn report_with_use_injections(&mut self, krate
: &Crate
) {
2495 for UseError { mut err, candidates, node_id, better }
in self.use_injections
.drain(..) {
2496 let (span
, found_use
) = UsePlacementFinder
::check(krate
, node_id
);
2497 if !candidates
.is_empty() {
2498 diagnostics
::show_candidates(&mut err
, span
, &candidates
, better
, found_use
);
2504 fn report_conflict
<'b
>(&mut self,
2508 new_binding
: &NameBinding
<'b
>,
2509 old_binding
: &NameBinding
<'b
>) {
2510 // Error on the second of two conflicting names
2511 if old_binding
.span
.lo() > new_binding
.span
.lo() {
2512 return self.report_conflict(parent
, ident
, ns
, old_binding
, new_binding
);
2515 let container
= match parent
.kind
{
2516 ModuleKind
::Def(DefKind
::Mod
, _
, _
) => "module",
2517 ModuleKind
::Def(DefKind
::Trait
, _
, _
) => "trait",
2518 ModuleKind
::Block(..) => "block",
2522 let old_noun
= match old_binding
.is_import() {
2524 false => "definition",
2527 let new_participle
= match new_binding
.is_import() {
2532 let (name
, span
) = (ident
.name
, self.session
.source_map().def_span(new_binding
.span
));
2534 if let Some(s
) = self.name_already_seen
.get(&name
) {
2540 let old_kind
= match (ns
, old_binding
.module()) {
2541 (ValueNS
, _
) => "value",
2542 (MacroNS
, _
) => "macro",
2543 (TypeNS
, _
) if old_binding
.is_extern_crate() => "extern crate",
2544 (TypeNS
, Some(module
)) if module
.is_normal() => "module",
2545 (TypeNS
, Some(module
)) if module
.is_trait() => "trait",
2546 (TypeNS
, _
) => "type",
2549 let msg
= format
!("the name `{}` is defined multiple times", name
);
2551 let mut err
= match (old_binding
.is_extern_crate(), new_binding
.is_extern_crate()) {
2552 (true, true) => struct_span_err
!(self.session
, span
, E0259
, "{}", msg
),
2553 (true, _
) | (_
, true) => match new_binding
.is_import() && old_binding
.is_import() {
2554 true => struct_span_err
!(self.session
, span
, E0254
, "{}", msg
),
2555 false => struct_span_err
!(self.session
, span
, E0260
, "{}", msg
),
2557 _
=> match (old_binding
.is_import(), new_binding
.is_import()) {
2558 (false, false) => struct_span_err
!(self.session
, span
, E0428
, "{}", msg
),
2559 (true, true) => struct_span_err
!(self.session
, span
, E0252
, "{}", msg
),
2560 _
=> struct_span_err
!(self.session
, span
, E0255
, "{}", msg
),
2564 err
.note(&format
!("`{}` must be defined only once in the {} namespace of this {}",
2569 err
.span_label(span
, format
!("`{}` re{} here", name
, new_participle
));
2571 self.session
.source_map().def_span(old_binding
.span
),
2572 format
!("previous {} of the {} `{}` here", old_noun
, old_kind
, name
),
2575 // See https://github.com/rust-lang/rust/issues/32354
2576 use NameBindingKind
::Import
;
2577 let directive
= match (&new_binding
.kind
, &old_binding
.kind
) {
2578 // If there are two imports where one or both have attributes then prefer removing the
2579 // import without attributes.
2580 (Import { directive: new, .. }
, Import { directive: old, .. }
) if {
2581 !new_binding
.span
.is_dummy() && !old_binding
.span
.is_dummy() &&
2582 (new
.has_attributes
|| old
.has_attributes
)
2584 if old
.has_attributes
{
2585 Some((new
, new_binding
.span
, true))
2587 Some((old
, old_binding
.span
, true))
2590 // Otherwise prioritize the new binding.
2591 (Import { directive, .. }
, other
) if !new_binding
.span
.is_dummy() =>
2592 Some((directive
, new_binding
.span
, other
.is_import())),
2593 (other
, Import { directive, .. }
) if !old_binding
.span
.is_dummy() =>
2594 Some((directive
, old_binding
.span
, other
.is_import())),
2598 // Check if the target of the use for both bindings is the same.
2599 let duplicate
= new_binding
.res().opt_def_id() == old_binding
.res().opt_def_id();
2600 let has_dummy_span
= new_binding
.span
.is_dummy() || old_binding
.span
.is_dummy();
2601 let from_item
= self.extern_prelude
.get(&ident
)
2602 .map(|entry
| entry
.introduced_by_item
)
2604 // Only suggest removing an import if both bindings are to the same def, if both spans
2605 // aren't dummy spans. Further, if both bindings are imports, then the ident must have
2606 // been introduced by a item.
2607 let should_remove_import
= duplicate
&& !has_dummy_span
&&
2608 ((new_binding
.is_extern_crate() || old_binding
.is_extern_crate()) || from_item
);
2611 Some((directive
, span
, true)) if should_remove_import
&& directive
.is_nested() =>
2612 self.add_suggestion_for_duplicate_nested_use(&mut err
, directive
, span
),
2613 Some((directive
, _
, true)) if should_remove_import
&& !directive
.is_glob() => {
2614 // Simple case - remove the entire import. Due to the above match arm, this can
2615 // only be a single use so just remove it entirely.
2616 err
.tool_only_span_suggestion(
2617 directive
.use_span_with_attributes
,
2618 "remove unnecessary import",
2620 Applicability
::MaybeIncorrect
,
2623 Some((directive
, span
, _
)) =>
2624 self.add_suggestion_for_rename_of_use(&mut err
, name
, directive
, span
),
2629 self.name_already_seen
.insert(name
, span
);
2632 /// This function adds a suggestion to change the binding name of a new import that conflicts
2633 /// with an existing import.
2635 /// ```ignore (diagnostic)
2636 /// help: you can use `as` to change the binding name of the import
2638 /// LL | use foo::bar as other_bar;
2639 /// | ^^^^^^^^^^^^^^^^^^^^^
2641 fn add_suggestion_for_rename_of_use(
2643 err
: &mut DiagnosticBuilder
<'_
>,
2645 directive
: &ImportDirective
<'_
>,
2648 let suggested_name
= if name
.as_str().chars().next().unwrap().is_uppercase() {
2649 format
!("Other{}", name
)
2651 format
!("other_{}", name
)
2654 let mut suggestion
= None
;
2655 match directive
.subclass
{
2656 ImportDirectiveSubclass
::SingleImport { type_ns_only: true, .. }
=>
2657 suggestion
= Some(format
!("self as {}", suggested_name
)),
2658 ImportDirectiveSubclass
::SingleImport { source, .. }
=> {
2659 if let Some(pos
) = source
.span
.hi().0.checked_sub(binding_span
.lo().0)
2660 .map(|pos
| pos
as usize) {
2661 if let Ok(snippet
) = self.session
.source_map()
2662 .span_to_snippet(binding_span
) {
2663 if pos
<= snippet
.len() {
2664 suggestion
= Some(format
!(
2668 if snippet
.ends_with(";") { ";" }
else { "" }
2674 ImportDirectiveSubclass
::ExternCrate { source, target, .. }
=>
2675 suggestion
= Some(format
!(
2676 "extern crate {} as {};",
2677 source
.unwrap_or(target
.name
),
2680 _
=> unreachable
!(),
2683 let rename_msg
= "you can use `as` to change the binding name of the import";
2684 if let Some(suggestion
) = suggestion
{
2685 err
.span_suggestion(
2689 Applicability
::MaybeIncorrect
,
2692 err
.span_label(binding_span
, rename_msg
);
2696 /// This function adds a suggestion to remove a unnecessary binding from an import that is
2697 /// nested. In the following example, this function will be invoked to remove the `a` binding
2698 /// in the second use statement:
2700 /// ```ignore (diagnostic)
2701 /// use issue_52891::a;
2702 /// use issue_52891::{d, a, e};
2705 /// The following suggestion will be added:
2707 /// ```ignore (diagnostic)
2708 /// use issue_52891::{d, a, e};
2709 /// ^-- help: remove unnecessary import
2712 /// If the nested use contains only one import then the suggestion will remove the entire
2715 /// It is expected that the directive provided is a nested import - this isn't checked by the
2716 /// function. If this invariant is not upheld, this function's behaviour will be unexpected
2717 /// as characters expected by span manipulations won't be present.
2718 fn add_suggestion_for_duplicate_nested_use(
2720 err
: &mut DiagnosticBuilder
<'_
>,
2721 directive
: &ImportDirective
<'_
>,
2724 assert
!(directive
.is_nested());
2725 let message
= "remove unnecessary import";
2727 // Two examples will be used to illustrate the span manipulations we're doing:
2729 // - Given `use issue_52891::{d, a, e};` where `a` is a duplicate then `binding_span` is
2730 // `a` and `directive.use_span` is `issue_52891::{d, a, e};`.
2731 // - Given `use issue_52891::{d, e, a};` where `a` is a duplicate then `binding_span` is
2732 // `a` and `directive.use_span` is `issue_52891::{d, e, a};`.
2734 let (found_closing_brace
, span
) = find_span_of_binding_until_next_binding(
2735 self.session
, binding_span
, directive
.use_span
,
2738 // If there was a closing brace then identify the span to remove any trailing commas from
2739 // previous imports.
2740 if found_closing_brace
{
2741 if let Some(span
) = extend_span_to_previous_binding(self.session
, span
) {
2742 err
.tool_only_span_suggestion(span
, message
, String
::new(),
2743 Applicability
::MaybeIncorrect
);
2745 // Remove the entire line if we cannot extend the span back, this indicates a
2746 // `issue_52891::{self}` case.
2747 err
.span_suggestion(directive
.use_span_with_attributes
, message
, String
::new(),
2748 Applicability
::MaybeIncorrect
);
2754 err
.span_suggestion(span
, message
, String
::new(), Applicability
::MachineApplicable
);
2757 fn extern_prelude_get(&mut self, ident
: Ident
, speculative
: bool
)
2758 -> Option
<&'a NameBinding
<'a
>> {
2759 if ident
.is_path_segment_keyword() {
2760 // Make sure `self`, `super` etc produce an error when passed to here.
2763 self.extern_prelude
.get(&ident
.modern()).cloned().and_then(|entry
| {
2764 if let Some(binding
) = entry
.extern_crate_item
{
2765 if !speculative
&& entry
.introduced_by_item
{
2766 self.record_use(ident
, TypeNS
, binding
, false);
2770 let crate_id
= if !speculative
{
2771 self.crate_loader
.process_path_extern(ident
.name
, ident
.span
)
2772 } else if let Some(crate_id
) =
2773 self.crate_loader
.maybe_process_path_extern(ident
.name
, ident
.span
) {
2778 let crate_root
= self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX }
);
2779 Some((crate_root
, ty
::Visibility
::Public
, DUMMY_SP
, ExpnId
::root())
2780 .to_name_binding(self.arenas
))
2785 /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
2786 /// isn't something that can be returned because it can't be made to live that long,
2787 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
2788 /// just that an error occurred.
2789 // FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
2790 pub fn resolve_str_path_error(
2791 &mut self, span
: Span
, path_str
: &str, ns
: Namespace
, module_id
: NodeId
2792 ) -> Result
<(ast
::Path
, Res
), ()> {
2793 let path
= if path_str
.starts_with("::") {
2796 segments
: iter
::once(Ident
::with_dummy_span(kw
::PathRoot
))
2798 path_str
.split("::").skip(1).map(Ident
::from_str
)
2800 .map(|i
| self.new_ast_path_segment(i
))
2808 .map(Ident
::from_str
)
2809 .map(|i
| self.new_ast_path_segment(i
))
2813 let module
= self.block_map
.get(&module_id
).copied().unwrap_or_else(|| {
2814 let def_id
= self.definitions
.local_def_id(module_id
);
2815 self.module_map
.get(&def_id
).copied().unwrap_or(self.graph_root
)
2817 let parent_scope
= &ParentScope
::module(module
);
2818 let res
= self.resolve_ast_path(&path
, ns
, parent_scope
).map_err(|_
| ())?
;
2822 // Resolve a path passed from rustdoc or HIR lowering.
2823 fn resolve_ast_path(
2827 parent_scope
: &ParentScope
<'a
>,
2828 ) -> Result
<Res
, (Span
, ResolutionError
<'a
>)> {
2829 match self.resolve_path(
2830 &Segment
::from_path(path
), Some(ns
), parent_scope
, true, path
.span
, CrateLint
::No
2832 PathResult
::Module(ModuleOrUniformRoot
::Module(module
)) =>
2833 Ok(module
.res().unwrap()),
2834 PathResult
::NonModule(path_res
) if path_res
.unresolved_segments() == 0 =>
2835 Ok(path_res
.base_res()),
2836 PathResult
::NonModule(..) => {
2837 Err((path
.span
, ResolutionError
::FailedToResolve
{
2838 label
: String
::from("type-relative paths are not supported in this context"),
2842 PathResult
::Module(..) | PathResult
::Indeterminate
=> unreachable
!(),
2843 PathResult
::Failed { span, label, suggestion, .. }
=> {
2844 Err((span
, ResolutionError
::FailedToResolve
{
2852 fn new_ast_path_segment(&self, ident
: Ident
) -> ast
::PathSegment
{
2853 let mut seg
= ast
::PathSegment
::from_ident(ident
);
2854 seg
.id
= self.session
.next_node_id();
2859 pub fn graph_root(&self) -> Module
<'a
> {
2864 pub fn all_macros(&self) -> &FxHashMap
<Name
, Res
> {
2869 fn names_to_string(names
: &[Name
]) -> String
{
2870 let mut result
= String
::new();
2871 for (i
, name
) in names
.iter()
2872 .filter(|name
| **name
!= kw
::PathRoot
)
2875 result
.push_str("::");
2877 result
.push_str(&name
.as_str());
2882 fn path_names_to_string(path
: &Path
) -> String
{
2883 names_to_string(&path
.segments
.iter()
2884 .map(|seg
| seg
.ident
.name
)
2885 .collect
::<Vec
<_
>>())
2888 /// A somewhat inefficient routine to obtain the name of a module.
2889 fn module_to_string(module
: Module
<'_
>) -> Option
<String
> {
2890 let mut names
= Vec
::new();
2892 fn collect_mod(names
: &mut Vec
<Name
>, module
: Module
<'_
>) {
2893 if let ModuleKind
::Def(.., name
) = module
.kind
{
2894 if let Some(parent
) = module
.parent
{
2896 collect_mod(names
, parent
);
2899 names
.push(Name
::intern("<opaque>"));
2900 collect_mod(names
, module
.parent
.unwrap());
2903 collect_mod(&mut names
, module
);
2905 if names
.is_empty() {
2909 Some(names_to_string(&names
))
2912 #[derive(Copy, Clone, Debug)]
2914 /// Do not issue the lint.
2917 /// This lint applies to some arbitrary path; e.g., `impl ::foo::Bar`.
2918 /// In this case, we can take the span of that path.
2921 /// This lint comes from a `use` statement. In this case, what we
2922 /// care about really is the *root* `use` statement; e.g., if we
2923 /// have nested things like `use a::{b, c}`, we care about the
2925 UsePath { root_id: NodeId, root_span: Span }
,
2927 /// This is the "trait item" from a fully qualified path. For example,
2928 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
2929 /// The `path_span` is the span of the to the trait itself (`X::Y`).
2930 QPathTrait { qpath_id: NodeId, qpath_span: Span }
,
2934 fn node_id(&self) -> Option
<NodeId
> {
2936 CrateLint
::No
=> None
,
2937 CrateLint
::SimplePath(id
) |
2938 CrateLint
::UsePath { root_id: id, .. }
|
2939 CrateLint
::QPathTrait { qpath_id: id, .. }
=> Some(id
),