1 // ignore-tidy-filelength
3 //! This crate is responsible for the part of name resolution that doesn't require type checker.
5 //! Module structure of the crate is built here.
6 //! Paths in macros, imports, expressions, types, patterns are resolved here.
7 //! Label and lifetime names are resolved here as well.
9 //! Type-relative name resolution (methods, fields, associated items) happens in `rustc_typeck`.
11 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
12 #![feature(box_patterns)]
13 #![feature(drain_filter)]
14 #![feature(bool_to_option)]
15 #![feature(crate_visibility_modifier)]
17 #![feature(never_type)]
19 #![recursion_limit = "256"]
20 #![allow(rustdoc::private_intra_doc_links)]
25 pub use rustc_hir
::def
::{Namespace, PerNS}
;
29 use rustc_arena
::{DroplessArena, TypedArena}
;
30 use rustc_ast
::node_id
::NodeMap
;
31 use rustc_ast
::ptr
::P
;
32 use rustc_ast
::visit
::{self, Visitor}
;
33 use rustc_ast
::{self as ast, NodeId}
;
34 use rustc_ast
::{Crate, CRATE_NODE_ID}
;
35 use rustc_ast
::{Expr, ExprKind, LitKind}
;
36 use rustc_ast
::{ItemKind, ModKind, Path}
;
37 use rustc_ast_lowering
::ResolverAstLowering
;
38 use rustc_ast_pretty
::pprust
;
39 use rustc_data_structures
::fx
::{FxHashMap, FxHashSet, FxIndexMap}
;
40 use rustc_data_structures
::ptr_key
::PtrKey
;
41 use rustc_data_structures
::sync
::Lrc
;
42 use rustc_errors
::{struct_span_err, Applicability, DiagnosticBuilder}
;
43 use rustc_expand
::base
::{DeriveResolutions, SyntaxExtension, SyntaxExtensionKind}
;
44 use rustc_hir
::def
::Namespace
::*;
45 use rustc_hir
::def
::{self, CtorOf, DefKind, NonMacroAttrKind, PartialRes}
;
46 use rustc_hir
::def_id
::{CrateNum, DefId, DefIdMap, DefPathHash, LocalDefId}
;
47 use rustc_hir
::def_id
::{CRATE_DEF_ID, CRATE_DEF_INDEX, LOCAL_CRATE}
;
48 use rustc_hir
::definitions
::{DefKey, DefPathData, Definitions}
;
49 use rustc_hir
::TraitCandidate
;
50 use rustc_index
::vec
::IndexVec
;
51 use rustc_metadata
::creader
::{CStore, CrateLoader}
;
52 use rustc_middle
::hir
::exports
::ExportMap
;
53 use rustc_middle
::span_bug
;
54 use rustc_middle
::ty
::query
::Providers
;
55 use rustc_middle
::ty
::{self, DefIdTree, MainDefinition, ResolverOutputs}
;
56 use rustc_query_system
::ich
::StableHashingContext
;
57 use rustc_session
::cstore
::{CrateStore, MetadataLoaderDyn}
;
58 use rustc_session
::lint
;
59 use rustc_session
::lint
::{BuiltinLintDiagnostics, LintBuffer}
;
60 use rustc_session
::Session
;
61 use rustc_span
::edition
::Edition
;
62 use rustc_span
::hygiene
::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext, Transparency}
;
63 use rustc_span
::source_map
::Spanned
;
64 use rustc_span
::symbol
::{kw, sym, Ident, Symbol}
;
65 use rustc_span
::{Span, DUMMY_SP}
;
67 use smallvec
::{smallvec, SmallVec}
;
68 use std
::cell
::{Cell, RefCell}
;
69 use std
::collections
::{BTreeMap, BTreeSet}
;
70 use std
::ops
::ControlFlow
;
71 use std
::{cmp, fmt, iter, mem, ptr}
;
74 use diagnostics
::{extend_span_to_previous_binding, find_span_of_binding_until_next_binding}
;
75 use diagnostics
::{ImportSuggestion, LabelSuggestion, Suggestion}
;
76 use imports
::{Import, ImportKind, ImportResolver, NameResolution}
;
77 use late
::{ConstantItemKind, HasGenericParams, PathSource, Rib, RibKind::*}
;
78 use macros
::{MacroRulesBinding, MacroRulesScope, MacroRulesScopeRef}
;
80 type Res
= def
::Res
<NodeId
>;
82 mod build_reduced_graph
;
95 #[derive(Copy, Clone, PartialEq, Debug)]
96 pub enum Determinacy
{
102 fn determined(determined
: bool
) -> Determinacy
{
103 if determined { Determinacy::Determined }
else { Determinacy::Undetermined }
107 /// A specific scope in which a name can be looked up.
108 /// This enum is currently used only for early resolution (imports and macros),
109 /// but not for late resolution yet.
110 #[derive(Clone, Copy)]
112 DeriveHelpers(LocalExpnId
),
114 MacroRules(MacroRulesScopeRef
<'a
>),
116 // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK`
117 // lint if it should be reported.
118 Module(Module
<'a
>, Option
<NodeId
>),
128 /// Names from different contexts may want to visit different subsets of all specific scopes
129 /// with different restrictions when looking up the resolution.
130 /// This enum is currently used only for early resolution (imports and macros),
131 /// but not for late resolution yet.
132 #[derive(Clone, Copy)]
134 /// All scopes with the given namespace.
135 All(Namespace
, /*is_import*/ bool
),
136 /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
137 AbsolutePath(Namespace
),
138 /// All scopes with macro namespace and the given macro kind restriction.
140 /// All scopes with the given namespace, used for partially performing late resolution.
141 /// The node id enables lints and is used for reporting them.
142 Late(Namespace
, Module
<'a
>, Option
<NodeId
>),
145 /// Everything you need to know about a name's location to resolve it.
146 /// Serves as a starting point for the scope visitor.
147 /// This struct is currently used only for early resolution (imports and macros),
148 /// but not for late resolution yet.
149 #[derive(Clone, Copy, Debug)]
150 pub struct ParentScope
<'a
> {
152 expansion
: LocalExpnId
,
153 macro_rules
: MacroRulesScopeRef
<'a
>,
154 derives
: &'a
[ast
::Path
],
157 impl<'a
> ParentScope
<'a
> {
158 /// Creates a parent scope with the passed argument used as the module scope component,
159 /// and other scope components set to default empty values.
160 pub fn module(module
: Module
<'a
>, resolver
: &Resolver
<'a
>) -> ParentScope
<'a
> {
163 expansion
: LocalExpnId
::ROOT
,
164 macro_rules
: resolver
.arenas
.alloc_macro_rules_scope(MacroRulesScope
::Empty
),
170 #[derive(Copy, Debug, Clone)]
171 enum ImplTraitContext
{
173 Universal(LocalDefId
),
177 struct BindingError
{
179 origin
: BTreeSet
<Span
>,
180 target
: BTreeSet
<Span
>,
184 impl PartialOrd
for BindingError
{
185 fn partial_cmp(&self, other
: &BindingError
) -> Option
<cmp
::Ordering
> {
186 Some(self.cmp(other
))
190 impl PartialEq
for BindingError
{
191 fn eq(&self, other
: &BindingError
) -> bool
{
192 self.name
== other
.name
196 impl Ord
for BindingError
{
197 fn cmp(&self, other
: &BindingError
) -> cmp
::Ordering
{
198 self.name
.cmp(&other
.name
)
202 enum ResolutionError
<'a
> {
203 /// Error E0401: can't use type or const parameters from outer function.
204 GenericParamsFromOuterFunction(Res
, HasGenericParams
),
205 /// Error E0403: the name is already used for a type or const parameter in this generic
207 NameAlreadyUsedInParameterList(Symbol
, Span
),
208 /// Error E0407: method is not a member of trait.
209 MethodNotMemberOfTrait(Ident
, &'a
str, Option
<Symbol
>),
210 /// Error E0437: type is not a member of trait.
211 TypeNotMemberOfTrait(Ident
, &'a
str, Option
<Symbol
>),
212 /// Error E0438: const is not a member of trait.
213 ConstNotMemberOfTrait(Ident
, &'a
str, Option
<Symbol
>),
214 /// Error E0408: variable `{}` is not bound in all patterns.
215 VariableNotBoundInPattern(&'a BindingError
),
216 /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
217 VariableBoundWithDifferentMode(Symbol
, Span
),
218 /// Error E0415: identifier is bound more than once in this parameter list.
219 IdentifierBoundMoreThanOnceInParameterList(Symbol
),
220 /// Error E0416: identifier is bound more than once in the same pattern.
221 IdentifierBoundMoreThanOnceInSamePattern(Symbol
),
222 /// Error E0426: use of undeclared label.
223 UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> }
,
224 /// Error E0429: `self` imports are only allowed within a `{ }` list.
225 SelfImportsOnlyAllowedWithin { root: bool, span_with_rename: Span }
,
226 /// Error E0430: `self` import can only appear once in the list.
227 SelfImportCanOnlyAppearOnceInTheList
,
228 /// Error E0431: `self` import can only appear in an import list with a non-empty prefix.
229 SelfImportOnlyInImportListWithNonEmptyPrefix
,
230 /// Error E0433: failed to resolve.
231 FailedToResolve { label: String, suggestion: Option<Suggestion> }
,
232 /// Error E0434: can't capture dynamic environment in a fn item.
233 CannotCaptureDynamicEnvironmentInFnItem
,
234 /// Error E0435: attempt to use a non-constant value in a constant.
235 AttemptToUseNonConstantValueInConstant(
237 /* suggestion */ &'
static str,
238 /* current */ &'
static str,
240 /// Error E0530: `X` bindings cannot shadow `Y`s.
241 BindingShadowsSomethingUnacceptable
{
242 shadowing_binding_descr
: &'
static str,
244 participle
: &'
static str,
245 article
: &'
static str,
246 shadowed_binding_descr
: &'
static str,
247 shadowed_binding_span
: Span
,
249 /// Error E0128: generic parameters with a default cannot use forward-declared identifiers.
250 ForwardDeclaredGenericParam
,
251 /// ERROR E0770: the type of const parameters must not depend on other generic parameters.
252 ParamInTyOfConstParam(Symbol
),
253 /// generic parameters must not be used inside const evaluations.
255 /// This error is only emitted when using `min_const_generics`.
256 ParamInNonTrivialAnonConst { name: Symbol, is_type: bool }
,
257 /// Error E0735: generic parameters with a default cannot use `Self`
258 SelfInGenericParamDefault
,
259 /// Error E0767: use of unreachable label
260 UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> }
,
263 enum VisResolutionError
<'a
> {
264 Relative2018(Span
, &'a ast
::Path
),
266 FailedToResolve(Span
, String
, Option
<Suggestion
>),
267 ExpectedFound(Span
, String
, Res
),
272 /// A minimal representation of a path segment. We use this in resolve because we synthesize 'path
273 /// segments' which don't have the rest of an AST or HIR `PathSegment`.
274 #[derive(Clone, Copy, Debug)]
278 /// Signals whether this `PathSegment` has generic arguments. Used to avoid providing
279 /// nonsensical suggestions.
280 has_generic_args
: bool
,
284 fn from_path(path
: &Path
) -> Vec
<Segment
> {
285 path
.segments
.iter().map(|s
| s
.into()).collect()
288 fn from_ident(ident
: Ident
) -> Segment
{
289 Segment { ident, id: None, has_generic_args: false }
292 fn names_to_string(segments
: &[Segment
]) -> String
{
293 names_to_string(&segments
.iter().map(|seg
| seg
.ident
.name
).collect
::<Vec
<_
>>())
297 impl<'a
> From
<&'a ast
::PathSegment
> for Segment
{
298 fn from(seg
: &'a ast
::PathSegment
) -> Segment
{
299 Segment { ident: seg.ident, id: Some(seg.id), has_generic_args: seg.args.is_some() }
303 struct UsePlacementFinder
{
304 target_module
: NodeId
,
309 impl UsePlacementFinder
{
310 fn check(krate
: &Crate
, target_module
: NodeId
) -> (Option
<Span
>, bool
) {
311 let mut finder
= UsePlacementFinder { target_module, span: None, found_use: false }
;
312 if let ControlFlow
::Continue(..) = finder
.check_mod(&krate
.items
, CRATE_NODE_ID
) {
313 visit
::walk_crate(&mut finder
, krate
);
315 (finder
.span
, finder
.found_use
)
318 fn check_mod(&mut self, items
: &[P
<ast
::Item
>], node_id
: NodeId
) -> ControlFlow
<()> {
319 if self.span
.is_some() {
320 return ControlFlow
::Break(());
322 if node_id
!= self.target_module
{
323 return ControlFlow
::Continue(());
325 // find a use statement
328 ItemKind
::Use(..) => {
329 // don't suggest placing a use before the prelude
330 // import or other generated ones
331 if !item
.span
.from_expansion() {
332 self.span
= Some(item
.span
.shrink_to_lo());
333 self.found_use
= true;
334 return ControlFlow
::Break(());
337 // don't place use before extern crate
338 ItemKind
::ExternCrate(_
) => {}
339 // but place them before the first other item
341 if self.span
.map_or(true, |span
| item
.span
< span
)
342 && !item
.span
.from_expansion()
344 self.span
= Some(item
.span
.shrink_to_lo());
345 // don't insert between attributes and an item
346 // find the first attribute on the item
347 // FIXME: This is broken for active attributes.
348 for attr
in &item
.attrs
{
349 if !attr
.span
.is_dummy()
350 && self.span
.map_or(true, |span
| attr
.span
< span
)
352 self.span
= Some(attr
.span
.shrink_to_lo());
359 ControlFlow
::Continue(())
363 impl<'tcx
> Visitor
<'tcx
> for UsePlacementFinder
{
364 fn visit_item(&mut self, item
: &'tcx ast
::Item
) {
365 if let ItemKind
::Mod(_
, ModKind
::Loaded(items
, ..)) = &item
.kind
{
366 if let ControlFlow
::Break(..) = self.check_mod(items
, item
.id
) {
370 visit
::walk_item(self, item
);
374 /// An intermediate resolution result.
376 /// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
377 /// items are visible in their whole block, while `Res`es only from the place they are defined
380 enum LexicalScopeBinding
<'a
> {
381 Item(&'a NameBinding
<'a
>),
385 impl<'a
> LexicalScopeBinding
<'a
> {
386 fn res(self) -> Res
{
388 LexicalScopeBinding
::Item(binding
) => binding
.res(),
389 LexicalScopeBinding
::Res(res
) => res
,
394 #[derive(Copy, Clone, Debug)]
395 enum ModuleOrUniformRoot
<'a
> {
399 /// Virtual module that denotes resolution in crate root with fallback to extern prelude.
400 CrateRootAndExternPrelude
,
402 /// Virtual module that denotes resolution in extern prelude.
403 /// Used for paths starting with `::` on 2018 edition.
406 /// Virtual module that denotes resolution in current scope.
407 /// Used only for resolving single-segment imports. The reason it exists is that import paths
408 /// are always split into two parts, the first of which should be some kind of module.
412 impl ModuleOrUniformRoot
<'_
> {
413 fn same_def(lhs
: Self, rhs
: Self) -> bool
{
415 (ModuleOrUniformRoot
::Module(lhs
), ModuleOrUniformRoot
::Module(rhs
)) => {
419 ModuleOrUniformRoot
::CrateRootAndExternPrelude
,
420 ModuleOrUniformRoot
::CrateRootAndExternPrelude
,
422 | (ModuleOrUniformRoot
::ExternPrelude
, ModuleOrUniformRoot
::ExternPrelude
)
423 | (ModuleOrUniformRoot
::CurrentScope
, ModuleOrUniformRoot
::CurrentScope
) => true,
429 #[derive(Clone, Debug)]
430 enum PathResult
<'a
> {
431 Module(ModuleOrUniformRoot
<'a
>),
432 NonModule(PartialRes
),
437 suggestion
: Option
<Suggestion
>,
438 is_error_from_last_segment
: bool
,
444 /// An anonymous module; e.g., just a block.
449 /// { // This is an anonymous module
450 /// f(); // This resolves to (2) as we are inside the block.
453 /// f(); // Resolves to (1)
457 /// Any module with a name.
461 /// * A normal module – either `mod from_file;` or `mod from_block { }` –
462 /// or the crate root (which is conceptually a top-level module).
463 /// Note that the crate root's [name][Self::name] will be [`kw::Empty`].
464 /// * A trait or an enum (it implicitly contains associated types, methods and variant
466 Def(DefKind
, DefId
, Symbol
),
470 /// Get name of the module.
471 pub fn name(&self) -> Option
<Symbol
> {
473 ModuleKind
::Block(..) => None
,
474 ModuleKind
::Def(.., name
) => Some(*name
),
479 /// A key that identifies a binding in a given `Module`.
481 /// Multiple bindings in the same module can have the same key (in a valid
482 /// program) if all but one of them come from glob imports.
483 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
485 /// The identifier for the binding, aways the `normalize_to_macros_2_0` version of the
489 /// 0 if ident is not `_`, otherwise a value that's unique to the specific
490 /// `_` in the expanded AST that introduced this binding.
494 type Resolutions
<'a
> = RefCell
<FxIndexMap
<BindingKey
, &'a RefCell
<NameResolution
<'a
>>>>;
496 /// One node in the tree of modules.
498 /// Note that a "module" in resolve is broader than a `mod` that you declare in Rust code. It may be one of these:
501 /// * crate root (aka, top-level anonymous module)
504 /// * curly-braced block with statements
506 /// You can use [`ModuleData::kind`] to determine the kind of module this is.
507 pub struct ModuleData
<'a
> {
508 /// The direct parent module (it may not be a `mod`, however).
509 parent
: Option
<Module
<'a
>>,
510 /// What kind of module this is, because this may not be a `mod`.
513 /// Mapping between names and their (possibly in-progress) resolutions in this module.
514 /// Resolutions in modules from other crates are not populated until accessed.
515 lazy_resolutions
: Resolutions
<'a
>,
516 /// True if this is a module from other crate that needs to be populated on access.
517 populate_on_access
: Cell
<bool
>,
519 /// Macro invocations that can expand into items in this module.
520 unexpanded_invocations
: RefCell
<FxHashSet
<LocalExpnId
>>,
522 /// Whether `#[no_implicit_prelude]` is active.
523 no_implicit_prelude
: bool
,
525 glob_importers
: RefCell
<Vec
<&'a Import
<'a
>>>,
526 globs
: RefCell
<Vec
<&'a Import
<'a
>>>,
528 /// Used to memoize the traits in this module for faster searches through all traits in scope.
529 traits
: RefCell
<Option
<Box
<[(Ident
, &'a NameBinding
<'a
>)]>>>,
531 /// Span of the module itself. Used for error reporting.
537 type Module
<'a
> = &'a ModuleData
<'a
>;
539 impl<'a
> ModuleData
<'a
> {
541 parent
: Option
<Module
<'a
>>,
545 no_implicit_prelude
: bool
,
547 let is_foreign
= match kind
{
548 ModuleKind
::Def(_
, def_id
, _
) => !def_id
.is_local(),
549 ModuleKind
::Block(_
) => false,
554 lazy_resolutions
: Default
::default(),
555 populate_on_access
: Cell
::new(is_foreign
),
556 unexpanded_invocations
: Default
::default(),
558 glob_importers
: RefCell
::new(Vec
::new()),
559 globs
: RefCell
::new(Vec
::new()),
560 traits
: RefCell
::new(None
),
566 fn for_each_child
<R
, F
>(&'a
self, resolver
: &mut R
, mut f
: F
)
568 R
: AsMut
<Resolver
<'a
>>,
569 F
: FnMut(&mut R
, Ident
, Namespace
, &'a NameBinding
<'a
>),
571 for (key
, name_resolution
) in resolver
.as_mut().resolutions(self).borrow().iter() {
572 if let Some(binding
) = name_resolution
.borrow().binding
{
573 f(resolver
, key
.ident
, key
.ns
, binding
);
578 /// This modifies `self` in place. The traits will be stored in `self.traits`.
579 fn ensure_traits
<R
>(&'a
self, resolver
: &mut R
)
581 R
: AsMut
<Resolver
<'a
>>,
583 let mut traits
= self.traits
.borrow_mut();
584 if traits
.is_none() {
585 let mut collected_traits
= Vec
::new();
586 self.for_each_child(resolver
, |_
, name
, ns
, binding
| {
590 if let Res
::Def(DefKind
::Trait
| DefKind
::TraitAlias
, _
) = binding
.res() {
591 collected_traits
.push((name
, binding
))
594 *traits
= Some(collected_traits
.into_boxed_slice());
598 fn res(&self) -> Option
<Res
> {
600 ModuleKind
::Def(kind
, def_id
, _
) => Some(Res
::Def(kind
, def_id
)),
605 fn def_id(&self) -> DefId
{
606 self.opt_def_id().expect("`ModuleData::def_id` is called on a block module")
609 fn opt_def_id(&self) -> Option
<DefId
> {
611 ModuleKind
::Def(_
, def_id
, _
) => Some(def_id
),
616 // `self` resolves to the first module ancestor that `is_normal`.
617 fn is_normal(&self) -> bool
{
618 matches
!(self.kind
, ModuleKind
::Def(DefKind
::Mod
, _
, _
))
621 fn is_trait(&self) -> bool
{
622 matches
!(self.kind
, ModuleKind
::Def(DefKind
::Trait
, _
, _
))
625 fn nearest_item_scope(&'a
self) -> Module
<'a
> {
627 ModuleKind
::Def(DefKind
::Enum
| DefKind
::Trait
, ..) => {
628 self.parent
.expect("enum or trait module without a parent")
634 /// The [`DefId`] of the nearest `mod` item ancestor (which may be this module).
635 /// This may be the crate root.
636 fn nearest_parent_mod(&self) -> DefId
{
638 ModuleKind
::Def(DefKind
::Mod
, def_id
, _
) => def_id
,
639 _
=> self.parent
.expect("non-root module without parent").nearest_parent_mod(),
643 fn is_ancestor_of(&self, mut other
: &Self) -> bool
{
644 while !ptr
::eq(self, other
) {
645 if let Some(parent
) = other
.parent
{
655 impl<'a
> fmt
::Debug
for ModuleData
<'a
> {
656 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
657 write
!(f
, "{:?}", self.res())
661 /// Records a possibly-private value, type, or module definition.
662 #[derive(Clone, Debug)]
663 pub struct NameBinding
<'a
> {
664 kind
: NameBindingKind
<'a
>,
665 ambiguity
: Option
<(&'a NameBinding
<'a
>, AmbiguityKind
)>,
666 expansion
: LocalExpnId
,
671 pub trait ToNameBinding
<'a
> {
672 fn to_name_binding(self, arenas
: &'a ResolverArenas
<'a
>) -> &'a NameBinding
<'a
>;
675 impl<'a
> ToNameBinding
<'a
> for &'a NameBinding
<'a
> {
676 fn to_name_binding(self, _
: &'a ResolverArenas
<'a
>) -> &'a NameBinding
<'a
> {
681 #[derive(Clone, Debug)]
682 enum NameBindingKind
<'a
> {
683 Res(Res
, /* is_macro_export */ bool
),
685 Import { binding: &'a NameBinding<'a>, import: &'a Import<'a>, used: Cell<bool> }
,
688 impl<'a
> NameBindingKind
<'a
> {
689 /// Is this a name binding of an import?
690 fn is_import(&self) -> bool
{
691 matches
!(*self, NameBindingKind
::Import { .. }
)
695 struct PrivacyError
<'a
> {
697 binding
: &'a NameBinding
<'a
>,
701 struct UseError
<'a
> {
702 err
: DiagnosticBuilder
<'a
>,
703 /// Candidates which user could `use` to access the missing type.
704 candidates
: Vec
<ImportSuggestion
>,
705 /// The `DefId` of the module to place the use-statements in.
707 /// Whether the diagnostic should say "instead" (as in `consider importing ... instead`).
709 /// Extra free-form suggestion.
710 suggestion
: Option
<(Span
, &'
static str, String
, Applicability
)>,
713 #[derive(Clone, Copy, PartialEq, Debug)]
718 MacroRulesVsModularized
,
726 fn descr(self) -> &'
static str {
728 AmbiguityKind
::Import
=> "multiple potential import sources",
729 AmbiguityKind
::BuiltinAttr
=> "a name conflict with a builtin attribute",
730 AmbiguityKind
::DeriveHelper
=> "a name conflict with a derive helper attribute",
731 AmbiguityKind
::MacroRulesVsModularized
=> {
732 "a conflict between a `macro_rules` name and a non-`macro_rules` name from another module"
734 AmbiguityKind
::GlobVsOuter
=> {
735 "a conflict between a name from a glob import and an outer scope during import or macro resolution"
737 AmbiguityKind
::GlobVsGlob
=> "multiple glob imports of a name in the same module",
738 AmbiguityKind
::GlobVsExpanded
=> {
739 "a conflict between a name from a glob import and a macro-expanded name in the same module during import or macro resolution"
741 AmbiguityKind
::MoreExpandedVsOuter
=> {
742 "a conflict between a macro-expanded name and a less macro-expanded name from outer scope during import or macro resolution"
748 /// Miscellaneous bits of metadata for better ambiguity error reporting.
749 #[derive(Clone, Copy, PartialEq)]
750 enum AmbiguityErrorMisc
{
757 struct AmbiguityError
<'a
> {
760 b1
: &'a NameBinding
<'a
>,
761 b2
: &'a NameBinding
<'a
>,
762 misc1
: AmbiguityErrorMisc
,
763 misc2
: AmbiguityErrorMisc
,
766 impl<'a
> NameBinding
<'a
> {
767 fn module(&self) -> Option
<Module
<'a
>> {
769 NameBindingKind
::Module(module
) => Some(module
),
770 NameBindingKind
::Import { binding, .. }
=> binding
.module(),
775 fn res(&self) -> Res
{
777 NameBindingKind
::Res(res
, _
) => res
,
778 NameBindingKind
::Module(module
) => module
.res().unwrap(),
779 NameBindingKind
::Import { binding, .. }
=> binding
.res(),
783 fn is_ambiguity(&self) -> bool
{
784 self.ambiguity
.is_some()
786 NameBindingKind
::Import { binding, .. }
=> binding
.is_ambiguity(),
791 fn is_possibly_imported_variant(&self) -> bool
{
793 NameBindingKind
::Import { binding, .. }
=> binding
.is_possibly_imported_variant(),
794 NameBindingKind
::Res(
795 Res
::Def(DefKind
::Variant
| DefKind
::Ctor(CtorOf
::Variant
, ..), _
),
798 NameBindingKind
::Res(..) | NameBindingKind
::Module(..) => false,
802 fn is_extern_crate(&self) -> bool
{
804 NameBindingKind
::Import
{
805 import
: &Import { kind: ImportKind::ExternCrate { .. }
, .. },
808 NameBindingKind
::Module(&ModuleData
{
809 kind
: ModuleKind
::Def(DefKind
::Mod
, def_id
, _
),
811 }) => def_id
.index
== CRATE_DEF_INDEX
,
816 fn is_import(&self) -> bool
{
817 matches
!(self.kind
, NameBindingKind
::Import { .. }
)
820 fn is_glob_import(&self) -> bool
{
822 NameBindingKind
::Import { import, .. }
=> import
.is_glob(),
827 fn is_importable(&self) -> bool
{
830 Res
::Def(DefKind
::AssocConst
| DefKind
::AssocFn
| DefKind
::AssocTy
, _
)
834 fn is_macro_def(&self) -> bool
{
835 matches
!(self.kind
, NameBindingKind
::Res(Res
::Def(DefKind
::Macro(..), _
), _
))
838 fn macro_kind(&self) -> Option
<MacroKind
> {
839 self.res().macro_kind()
842 // Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
843 // at some expansion round `max(invoc, binding)` when they both emerged from macros.
844 // Then this function returns `true` if `self` may emerge from a macro *after* that
845 // in some later round and screw up our previously found resolution.
846 // See more detailed explanation in
847 // https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
850 invoc_parent_expansion
: LocalExpnId
,
851 binding
: &NameBinding
<'_
>,
853 // self > max(invoc, binding) => !(self <= invoc || self <= binding)
854 // Expansions are partially ordered, so "may appear after" is an inversion of
855 // "certainly appears before or simultaneously" and includes unordered cases.
856 let self_parent_expansion
= self.expansion
;
857 let other_parent_expansion
= binding
.expansion
;
858 let certainly_before_other_or_simultaneously
=
859 other_parent_expansion
.is_descendant_of(self_parent_expansion
);
860 let certainly_before_invoc_or_simultaneously
=
861 invoc_parent_expansion
.is_descendant_of(self_parent_expansion
);
862 !(certainly_before_other_or_simultaneously
|| certainly_before_invoc_or_simultaneously
)
866 #[derive(Debug, Default, Clone)]
867 pub struct ExternPreludeEntry
<'a
> {
868 extern_crate_item
: Option
<&'a NameBinding
<'a
>>,
869 pub introduced_by_item
: bool
,
872 /// Used for better errors for E0773
873 enum BuiltinMacroState
{
874 NotYetSeen(SyntaxExtensionKind
),
879 resolutions
: DeriveResolutions
,
880 helper_attrs
: Vec
<(usize, Ident
)>,
881 has_derive_copy
: bool
,
884 /// The main resolver class.
886 /// This is the visitor that walks the whole crate.
887 pub struct Resolver
<'a
> {
888 session
: &'a Session
,
890 definitions
: Definitions
,
892 graph_root
: Module
<'a
>,
894 prelude
: Option
<Module
<'a
>>,
895 extern_prelude
: FxHashMap
<Ident
, ExternPreludeEntry
<'a
>>,
897 /// N.B., this is used only for better diagnostics, not name resolution itself.
898 has_self
: FxHashSet
<DefId
>,
900 /// Names of fields of an item `DefId` accessible with dot syntax.
901 /// Used for hints during error reporting.
902 field_names
: FxHashMap
<DefId
, Vec
<Spanned
<Symbol
>>>,
904 /// All imports known to succeed or fail.
905 determined_imports
: Vec
<&'a Import
<'a
>>,
907 /// All non-determined imports.
908 indeterminate_imports
: Vec
<&'a Import
<'a
>>,
910 /// FIXME: Refactor things so that these fields are passed through arguments and not resolver.
911 /// We are resolving a last import segment during import validation.
912 last_import_segment
: bool
,
913 /// This binding should be ignored during in-module resolution, so that we don't get
914 /// "self-confirming" import resolutions during import validation.
915 unusable_binding
: Option
<&'a NameBinding
<'a
>>,
917 // Spans for local variables found during pattern resolution.
918 // Used for suggestions during error reporting.
919 pat_span_map
: NodeMap
<Span
>,
921 /// Resolutions for nodes that have a single resolution.
922 partial_res_map
: NodeMap
<PartialRes
>,
923 /// Resolutions for import nodes, which have multiple resolutions in different namespaces.
924 import_res_map
: NodeMap
<PerNS
<Option
<Res
>>>,
925 /// Resolutions for labels (node IDs of their corresponding blocks or loops).
926 label_res_map
: NodeMap
<NodeId
>,
928 /// `CrateNum` resolutions of `extern crate` items.
929 extern_crate_map
: FxHashMap
<LocalDefId
, CrateNum
>,
930 export_map
: ExportMap
,
931 trait_map
: NodeMap
<Vec
<TraitCandidate
>>,
933 /// A map from nodes to anonymous modules.
934 /// Anonymous modules are pseudo-modules that are implicitly created around items
935 /// contained within blocks.
937 /// For example, if we have this:
945 /// There will be an anonymous module created around `g` with the ID of the
946 /// entry block for `f`.
947 block_map
: NodeMap
<Module
<'a
>>,
948 /// A fake module that contains no definition and no prelude. Used so that
949 /// some AST passes can generate identifiers that only resolve to local or
951 empty_module
: Module
<'a
>,
952 module_map
: FxHashMap
<DefId
, Module
<'a
>>,
953 binding_parent_modules
: FxHashMap
<PtrKey
<'a
, NameBinding
<'a
>>, Module
<'a
>>,
954 underscore_disambiguator
: u32,
956 /// Maps glob imports to the names of items actually imported.
957 glob_map
: FxHashMap
<LocalDefId
, FxHashSet
<Symbol
>>,
958 /// Visibilities in "lowered" form, for all entities that have them.
959 visibilities
: FxHashMap
<LocalDefId
, ty
::Visibility
>,
960 used_imports
: FxHashSet
<NodeId
>,
961 maybe_unused_trait_imports
: FxHashSet
<LocalDefId
>,
962 maybe_unused_extern_crates
: Vec
<(LocalDefId
, Span
)>,
964 /// Privacy errors are delayed until the end in order to deduplicate them.
965 privacy_errors
: Vec
<PrivacyError
<'a
>>,
966 /// Ambiguity errors are delayed for deduplication.
967 ambiguity_errors
: Vec
<AmbiguityError
<'a
>>,
968 /// `use` injections are delayed for better placement and deduplication.
969 use_injections
: Vec
<UseError
<'a
>>,
970 /// Crate-local macro expanded `macro_export` referred to by a module-relative path.
971 macro_expanded_macro_export_errors
: BTreeSet
<(Span
, Span
)>,
973 arenas
: &'a ResolverArenas
<'a
>,
974 dummy_binding
: &'a NameBinding
<'a
>,
976 crate_loader
: CrateLoader
<'a
>,
977 macro_names
: FxHashSet
<Ident
>,
978 builtin_macros
: FxHashMap
<Symbol
, BuiltinMacroState
>,
979 registered_attrs
: FxHashSet
<Ident
>,
980 registered_tools
: FxHashSet
<Ident
>,
981 macro_use_prelude
: FxHashMap
<Symbol
, &'a NameBinding
<'a
>>,
982 all_macros
: FxHashMap
<Symbol
, Res
>,
983 macro_map
: FxHashMap
<DefId
, Lrc
<SyntaxExtension
>>,
984 dummy_ext_bang
: Lrc
<SyntaxExtension
>,
985 dummy_ext_derive
: Lrc
<SyntaxExtension
>,
986 non_macro_attr
: Lrc
<SyntaxExtension
>,
987 local_macro_def_scopes
: FxHashMap
<LocalDefId
, Module
<'a
>>,
988 ast_transform_scopes
: FxHashMap
<LocalExpnId
, Module
<'a
>>,
989 unused_macros
: FxHashMap
<LocalDefId
, (NodeId
, Ident
)>,
990 proc_macro_stubs
: FxHashSet
<LocalDefId
>,
991 /// Traces collected during macro resolution and validated when it's complete.
992 single_segment_macro_resolutions
:
993 Vec
<(Ident
, MacroKind
, ParentScope
<'a
>, Option
<&'a NameBinding
<'a
>>)>,
994 multi_segment_macro_resolutions
:
995 Vec
<(Vec
<Segment
>, Span
, MacroKind
, ParentScope
<'a
>, Option
<Res
>)>,
996 builtin_attrs
: Vec
<(Ident
, ParentScope
<'a
>)>,
997 /// `derive(Copy)` marks items they are applied to so they are treated specially later.
998 /// Derive macros cannot modify the item themselves and have to store the markers in the global
999 /// context, so they attach the markers to derive container IDs using this resolver table.
1000 containers_deriving_copy
: FxHashSet
<LocalExpnId
>,
1001 /// Parent scopes in which the macros were invoked.
1002 /// FIXME: `derives` are missing in these parent scopes and need to be taken from elsewhere.
1003 invocation_parent_scopes
: FxHashMap
<LocalExpnId
, ParentScope
<'a
>>,
1004 /// `macro_rules` scopes *produced* by expanding the macro invocations,
1005 /// include all the `macro_rules` items and other invocations generated by them.
1006 output_macro_rules_scopes
: FxHashMap
<LocalExpnId
, MacroRulesScopeRef
<'a
>>,
1007 /// Helper attributes that are in scope for the given expansion.
1008 helper_attrs
: FxHashMap
<LocalExpnId
, Vec
<Ident
>>,
1009 /// Ready or in-progress results of resolving paths inside the `#[derive(...)]` attribute
1010 /// with the given `ExpnId`.
1011 derive_data
: FxHashMap
<LocalExpnId
, DeriveData
>,
1013 /// Avoid duplicated errors for "name already defined".
1014 name_already_seen
: FxHashMap
<Symbol
, Span
>,
1016 potentially_unused_imports
: Vec
<&'a Import
<'a
>>,
1018 /// Table for mapping struct IDs into struct constructor IDs,
1019 /// it's not used during normal resolution, only for better error reporting.
1020 /// Also includes of list of each fields visibility
1021 struct_constructors
: DefIdMap
<(Res
, ty
::Visibility
, Vec
<ty
::Visibility
>)>,
1023 /// Features enabled for this crate.
1024 active_features
: FxHashSet
<Symbol
>,
1026 lint_buffer
: LintBuffer
,
1028 next_node_id
: NodeId
,
1030 node_id_to_def_id
: FxHashMap
<ast
::NodeId
, LocalDefId
>,
1031 def_id_to_node_id
: IndexVec
<LocalDefId
, ast
::NodeId
>,
1033 /// Indices of unnamed struct or variant fields with unresolved attributes.
1034 placeholder_field_indices
: FxHashMap
<NodeId
, usize>,
1035 /// When collecting definitions from an AST fragment produced by a macro invocation `ExpnId`
1036 /// we know what parent node that fragment should be attached to thanks to this table,
1037 /// and how the `impl Trait` fragments were introduced.
1038 invocation_parents
: FxHashMap
<LocalExpnId
, (LocalDefId
, ImplTraitContext
)>,
1040 next_disambiguator
: FxHashMap
<(LocalDefId
, DefPathData
), u32>,
1041 /// Some way to know that we are in a *trait* impl in `visit_assoc_item`.
1042 /// FIXME: Replace with a more general AST map (together with some other fields).
1043 trait_impl_items
: FxHashSet
<LocalDefId
>,
1045 legacy_const_generic_args
: FxHashMap
<DefId
, Option
<Vec
<usize>>>,
1046 /// Amount of lifetime parameters for each item in the crate.
1047 item_generics_num_lifetimes
: FxHashMap
<LocalDefId
, usize>,
1049 main_def
: Option
<MainDefinition
>,
1050 trait_impls
: BTreeMap
<DefId
, Vec
<LocalDefId
>>,
1051 /// A list of proc macro LocalDefIds, written out in the order in which
1052 /// they are declared in the static array generated by proc_macro_harness.
1053 proc_macros
: Vec
<NodeId
>,
1054 confused_type_with_std_module
: FxHashMap
<Span
, Span
>,
1057 /// Nothing really interesting here; it just provides memory for the rest of the crate.
1059 pub struct ResolverArenas
<'a
> {
1060 modules
: TypedArena
<ModuleData
<'a
>>,
1061 local_modules
: RefCell
<Vec
<Module
<'a
>>>,
1062 imports
: TypedArena
<Import
<'a
>>,
1063 name_resolutions
: TypedArena
<RefCell
<NameResolution
<'a
>>>,
1064 ast_paths
: TypedArena
<ast
::Path
>,
1065 dropless
: DroplessArena
,
1068 impl<'a
> ResolverArenas
<'a
> {
1071 parent
: Option
<Module
<'a
>>,
1075 no_implicit_prelude
: bool
,
1076 module_map
: &mut FxHashMap
<DefId
, Module
<'a
>>,
1079 self.modules
.alloc(ModuleData
::new(parent
, kind
, expn_id
, span
, no_implicit_prelude
));
1080 let def_id
= module
.opt_def_id();
1081 if def_id
.map_or(true, |def_id
| def_id
.is_local()) {
1082 self.local_modules
.borrow_mut().push(module
);
1084 if let Some(def_id
) = def_id
{
1085 module_map
.insert(def_id
, module
);
1089 fn local_modules(&'a
self) -> std
::cell
::Ref
<'a
, Vec
<Module
<'a
>>> {
1090 self.local_modules
.borrow()
1092 fn alloc_name_binding(&'a
self, name_binding
: NameBinding
<'a
>) -> &'a NameBinding
<'a
> {
1093 self.dropless
.alloc(name_binding
)
1095 fn alloc_import(&'a
self, import
: Import
<'a
>) -> &'a Import
<'_
> {
1096 self.imports
.alloc(import
)
1098 fn alloc_name_resolution(&'a
self) -> &'a RefCell
<NameResolution
<'a
>> {
1099 self.name_resolutions
.alloc(Default
::default())
1101 fn alloc_macro_rules_scope(&'a
self, scope
: MacroRulesScope
<'a
>) -> MacroRulesScopeRef
<'a
> {
1102 PtrKey(self.dropless
.alloc(Cell
::new(scope
)))
1104 fn alloc_macro_rules_binding(
1106 binding
: MacroRulesBinding
<'a
>,
1107 ) -> &'a MacroRulesBinding
<'a
> {
1108 self.dropless
.alloc(binding
)
1110 fn alloc_ast_paths(&'a
self, paths
: &[ast
::Path
]) -> &'a
[ast
::Path
] {
1111 self.ast_paths
.alloc_from_iter(paths
.iter().cloned())
1113 fn alloc_pattern_spans(&'a
self, spans
: impl Iterator
<Item
= Span
>) -> &'a
[Span
] {
1114 self.dropless
.alloc_from_iter(spans
)
1118 impl<'a
> AsMut
<Resolver
<'a
>> for Resolver
<'a
> {
1119 fn as_mut(&mut self) -> &mut Resolver
<'a
> {
1124 impl<'a
, 'b
> DefIdTree
for &'a Resolver
<'b
> {
1125 fn parent(self, id
: DefId
) -> Option
<DefId
> {
1126 match id
.as_local() {
1127 Some(id
) => self.definitions
.def_key(id
).parent
,
1128 None
=> self.cstore().def_key(id
).parent
,
1130 .map(|index
| DefId { index, ..id }
)
1134 /// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
1135 /// the resolver is no longer needed as all the relevant information is inline.
1136 impl ResolverAstLowering
for Resolver
<'_
> {
1137 fn def_key(&mut self, id
: DefId
) -> DefKey
{
1138 if let Some(id
) = id
.as_local() {
1139 self.definitions().def_key(id
)
1141 self.cstore().def_key(id
)
1146 fn def_span(&self, id
: LocalDefId
) -> Span
{
1147 self.definitions
.def_span(id
)
1150 fn item_generics_num_lifetimes(&self, def_id
: DefId
) -> usize {
1151 if let Some(def_id
) = def_id
.as_local() {
1152 self.item_generics_num_lifetimes
[&def_id
]
1154 self.cstore().item_generics_num_lifetimes(def_id
, self.session
)
1158 fn legacy_const_generic_args(&mut self, expr
: &Expr
) -> Option
<Vec
<usize>> {
1159 self.legacy_const_generic_args(expr
)
1162 fn get_partial_res(&self, id
: NodeId
) -> Option
<PartialRes
> {
1163 self.partial_res_map
.get(&id
).cloned()
1166 fn get_import_res(&mut self, id
: NodeId
) -> PerNS
<Option
<Res
>> {
1167 self.import_res_map
.get(&id
).cloned().unwrap_or_default()
1170 fn get_label_res(&mut self, id
: NodeId
) -> Option
<NodeId
> {
1171 self.label_res_map
.get(&id
).cloned()
1174 fn definitions(&mut self) -> &mut Definitions
{
1175 &mut self.definitions
1178 fn create_stable_hashing_context(&self) -> StableHashingContext
<'_
> {
1179 StableHashingContext
::new(self.session
, &self.definitions
, self.crate_loader
.cstore())
1182 fn lint_buffer(&mut self) -> &mut LintBuffer
{
1183 &mut self.lint_buffer
1186 fn next_node_id(&mut self) -> NodeId
{
1190 fn take_trait_map(&mut self, node
: NodeId
) -> Option
<Vec
<TraitCandidate
>> {
1191 self.trait_map
.remove(&node
)
1194 fn opt_local_def_id(&self, node
: NodeId
) -> Option
<LocalDefId
> {
1195 self.node_id_to_def_id
.get(&node
).copied()
1198 fn local_def_id(&self, node
: NodeId
) -> LocalDefId
{
1199 self.opt_local_def_id(node
).unwrap_or_else(|| panic
!("no entry for node id: `{:?}`", node
))
1202 fn def_path_hash(&self, def_id
: DefId
) -> DefPathHash
{
1203 match def_id
.as_local() {
1204 Some(def_id
) => self.definitions
.def_path_hash(def_id
),
1205 None
=> self.cstore().def_path_hash(def_id
),
1209 /// Adds a definition with a parent definition.
1213 node_id
: ast
::NodeId
,
1219 !self.node_id_to_def_id
.contains_key(&node_id
),
1220 "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
1223 self.definitions
.def_key(self.node_id_to_def_id
[&node_id
]),
1226 // Find the next free disambiguator for this key.
1227 let next_disambiguator
= &mut self.next_disambiguator
;
1228 let next_disambiguator
= |parent
, data
| {
1229 let next_disamb
= next_disambiguator
.entry((parent
, data
)).or_insert(0);
1230 let disambiguator
= *next_disamb
;
1231 *next_disamb
= next_disamb
.checked_add(1).expect("disambiguator overflow");
1235 let def_id
= self.definitions
.create_def(parent
, data
, expn_id
, next_disambiguator
, span
);
1237 // Some things for which we allocate `LocalDefId`s don't correspond to
1238 // anything in the AST, so they don't have a `NodeId`. For these cases
1239 // we don't need a mapping from `NodeId` to `LocalDefId`.
1240 if node_id
!= ast
::DUMMY_NODE_ID
{
1241 debug
!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id
, node_id
);
1242 self.node_id_to_def_id
.insert(node_id
, def_id
);
1244 assert_eq
!(self.def_id_to_node_id
.push(node_id
), def_id
);
1250 impl<'a
> Resolver
<'a
> {
1252 session
: &'a Session
,
1255 metadata_loader
: Box
<MetadataLoaderDyn
>,
1256 arenas
: &'a ResolverArenas
<'a
>,
1258 let root_def_id
= CRATE_DEF_ID
.to_def_id();
1259 let mut module_map
= FxHashMap
::default();
1260 let graph_root
= arenas
.new_module(
1262 ModuleKind
::Def(DefKind
::Mod
, root_def_id
, kw
::Empty
),
1265 session
.contains_name(&krate
.attrs
, sym
::no_implicit_prelude
),
1268 let empty_module
= arenas
.new_module(
1270 ModuleKind
::Def(DefKind
::Mod
, root_def_id
, kw
::Empty
),
1274 &mut FxHashMap
::default(),
1277 let definitions
= Definitions
::new(session
.local_stable_crate_id(), krate
.span
);
1278 let root
= definitions
.get_root_def();
1280 let mut visibilities
= FxHashMap
::default();
1281 visibilities
.insert(CRATE_DEF_ID
, ty
::Visibility
::Public
);
1283 let mut def_id_to_node_id
= IndexVec
::default();
1284 assert_eq
!(def_id_to_node_id
.push(CRATE_NODE_ID
), root
);
1285 let mut node_id_to_def_id
= FxHashMap
::default();
1286 node_id_to_def_id
.insert(CRATE_NODE_ID
, root
);
1288 let mut invocation_parents
= FxHashMap
::default();
1289 invocation_parents
.insert(LocalExpnId
::ROOT
, (root
, ImplTraitContext
::Existential
));
1291 let mut extern_prelude
: FxHashMap
<Ident
, ExternPreludeEntry
<'_
>> = session
1295 .filter(|(_
, entry
)| entry
.add_prelude
)
1296 .map(|(name
, _
)| (Ident
::from_str(name
), Default
::default()))
1299 if !session
.contains_name(&krate
.attrs
, sym
::no_core
) {
1300 extern_prelude
.insert(Ident
::with_dummy_span(sym
::core
), Default
::default());
1301 if !session
.contains_name(&krate
.attrs
, sym
::no_std
) {
1302 extern_prelude
.insert(Ident
::with_dummy_span(sym
::std
), Default
::default());
1306 let (registered_attrs
, registered_tools
) =
1307 macros
::registered_attrs_and_tools(session
, &krate
.attrs
);
1309 let features
= session
.features_untracked();
1311 let mut resolver
= Resolver
{
1316 // The outermost module has def ID 0; this is not reflected in the
1322 has_self
: FxHashSet
::default(),
1323 field_names
: FxHashMap
::default(),
1325 determined_imports
: Vec
::new(),
1326 indeterminate_imports
: Vec
::new(),
1328 last_import_segment
: false,
1329 unusable_binding
: None
,
1331 pat_span_map
: Default
::default(),
1332 partial_res_map
: Default
::default(),
1333 import_res_map
: Default
::default(),
1334 label_res_map
: Default
::default(),
1335 extern_crate_map
: Default
::default(),
1336 export_map
: FxHashMap
::default(),
1337 trait_map
: NodeMap
::default(),
1338 underscore_disambiguator
: 0,
1341 block_map
: Default
::default(),
1342 binding_parent_modules
: FxHashMap
::default(),
1343 ast_transform_scopes
: FxHashMap
::default(),
1345 glob_map
: Default
::default(),
1347 used_imports
: FxHashSet
::default(),
1348 maybe_unused_trait_imports
: Default
::default(),
1349 maybe_unused_extern_crates
: Vec
::new(),
1351 privacy_errors
: Vec
::new(),
1352 ambiguity_errors
: Vec
::new(),
1353 use_injections
: Vec
::new(),
1354 macro_expanded_macro_export_errors
: BTreeSet
::new(),
1357 dummy_binding
: arenas
.alloc_name_binding(NameBinding
{
1358 kind
: NameBindingKind
::Res(Res
::Err
, false),
1360 expansion
: LocalExpnId
::ROOT
,
1362 vis
: ty
::Visibility
::Public
,
1365 crate_loader
: CrateLoader
::new(session
, metadata_loader
, crate_name
),
1366 macro_names
: FxHashSet
::default(),
1367 builtin_macros
: Default
::default(),
1370 macro_use_prelude
: FxHashMap
::default(),
1371 all_macros
: FxHashMap
::default(),
1372 macro_map
: FxHashMap
::default(),
1373 dummy_ext_bang
: Lrc
::new(SyntaxExtension
::dummy_bang(session
.edition())),
1374 dummy_ext_derive
: Lrc
::new(SyntaxExtension
::dummy_derive(session
.edition())),
1375 non_macro_attr
: Lrc
::new(SyntaxExtension
::non_macro_attr(session
.edition())),
1376 invocation_parent_scopes
: Default
::default(),
1377 output_macro_rules_scopes
: Default
::default(),
1378 helper_attrs
: Default
::default(),
1379 derive_data
: Default
::default(),
1380 local_macro_def_scopes
: FxHashMap
::default(),
1381 name_already_seen
: FxHashMap
::default(),
1382 potentially_unused_imports
: Vec
::new(),
1383 struct_constructors
: Default
::default(),
1384 unused_macros
: Default
::default(),
1385 proc_macro_stubs
: Default
::default(),
1386 single_segment_macro_resolutions
: Default
::default(),
1387 multi_segment_macro_resolutions
: Default
::default(),
1388 builtin_attrs
: Default
::default(),
1389 containers_deriving_copy
: Default
::default(),
1390 active_features
: features
1391 .declared_lib_features
1393 .map(|(feat
, ..)| *feat
)
1394 .chain(features
.declared_lang_features
.iter().map(|(feat
, ..)| *feat
))
1396 lint_buffer
: LintBuffer
::default(),
1397 next_node_id
: CRATE_NODE_ID
,
1400 placeholder_field_indices
: Default
::default(),
1402 next_disambiguator
: Default
::default(),
1403 trait_impl_items
: Default
::default(),
1404 legacy_const_generic_args
: Default
::default(),
1405 item_generics_num_lifetimes
: Default
::default(),
1406 main_def
: Default
::default(),
1407 trait_impls
: Default
::default(),
1408 proc_macros
: Default
::default(),
1409 confused_type_with_std_module
: Default
::default(),
1412 let root_parent_scope
= ParentScope
::module(graph_root
, &resolver
);
1413 resolver
.invocation_parent_scopes
.insert(LocalExpnId
::ROOT
, root_parent_scope
);
1420 parent
: Option
<Module
<'a
>>,
1424 no_implicit_prelude
: bool
,
1426 let module_map
= &mut self.module_map
;
1427 self.arenas
.new_module(parent
, kind
, expn_id
, span
, no_implicit_prelude
, module_map
)
1430 pub fn next_node_id(&mut self) -> NodeId
{
1432 self.next_node_id
.as_u32().checked_add(1).expect("input too large; ran out of NodeIds");
1433 mem
::replace(&mut self.next_node_id
, ast
::NodeId
::from_u32(next
))
1436 pub fn lint_buffer(&mut self) -> &mut LintBuffer
{
1437 &mut self.lint_buffer
1440 pub fn arenas() -> ResolverArenas
<'a
> {
1444 pub fn into_outputs(self) -> ResolverOutputs
{
1445 let proc_macros
= self.proc_macros
.iter().map(|id
| self.local_def_id(*id
)).collect();
1446 let definitions
= self.definitions
;
1447 let visibilities
= self.visibilities
;
1448 let extern_crate_map
= self.extern_crate_map
;
1449 let export_map
= self.export_map
;
1450 let maybe_unused_trait_imports
= self.maybe_unused_trait_imports
;
1451 let maybe_unused_extern_crates
= self.maybe_unused_extern_crates
;
1452 let glob_map
= self.glob_map
;
1453 let main_def
= self.main_def
;
1454 let confused_type_with_std_module
= self.confused_type_with_std_module
;
1457 cstore
: Box
::new(self.crate_loader
.into_cstore()),
1462 maybe_unused_trait_imports
,
1463 maybe_unused_extern_crates
,
1464 extern_prelude
: self
1467 .map(|(ident
, entry
)| (ident
.name
, entry
.introduced_by_item
))
1470 trait_impls
: self.trait_impls
,
1472 confused_type_with_std_module
,
1476 pub fn clone_outputs(&self) -> ResolverOutputs
{
1477 let proc_macros
= self.proc_macros
.iter().map(|id
| self.local_def_id(*id
)).collect();
1479 definitions
: self.definitions
.clone(),
1480 cstore
: Box
::new(self.cstore().clone()),
1481 visibilities
: self.visibilities
.clone(),
1482 extern_crate_map
: self.extern_crate_map
.clone(),
1483 export_map
: self.export_map
.clone(),
1484 glob_map
: self.glob_map
.clone(),
1485 maybe_unused_trait_imports
: self.maybe_unused_trait_imports
.clone(),
1486 maybe_unused_extern_crates
: self.maybe_unused_extern_crates
.clone(),
1487 extern_prelude
: self
1490 .map(|(ident
, entry
)| (ident
.name
, entry
.introduced_by_item
))
1492 main_def
: self.main_def
,
1493 trait_impls
: self.trait_impls
.clone(),
1495 confused_type_with_std_module
: self.confused_type_with_std_module
.clone(),
1499 pub fn cstore(&self) -> &CStore
{
1500 self.crate_loader
.cstore()
1503 fn dummy_ext(&self, macro_kind
: MacroKind
) -> Lrc
<SyntaxExtension
> {
1505 MacroKind
::Bang
=> self.dummy_ext_bang
.clone(),
1506 MacroKind
::Derive
=> self.dummy_ext_derive
.clone(),
1507 MacroKind
::Attr
=> self.non_macro_attr
.clone(),
1511 /// Runs the function on each namespace.
1512 fn per_ns
<F
: FnMut(&mut Self, Namespace
)>(&mut self, mut f
: F
) {
1518 fn is_builtin_macro(&mut self, res
: Res
) -> bool
{
1519 self.get_macro(res
).map_or(false, |ext
| ext
.builtin_name
.is_some())
1522 fn macro_def(&self, mut ctxt
: SyntaxContext
) -> DefId
{
1524 match ctxt
.outer_expn_data().macro_def_id
{
1525 Some(def_id
) => return def_id
,
1526 None
=> ctxt
.remove_mark(),
1531 /// Entry point to crate resolution.
1532 pub fn resolve_crate(&mut self, krate
: &Crate
) {
1533 self.session
.time("resolve_crate", || {
1534 self.session
.time("finalize_imports", || ImportResolver { r: self }
.finalize_imports());
1535 self.session
.time("finalize_macro_resolutions", || self.finalize_macro_resolutions());
1536 self.session
.time("late_resolve_crate", || self.late_resolve_crate(krate
));
1537 self.session
.time("resolve_main", || self.resolve_main());
1538 self.session
.time("resolve_check_unused", || self.check_unused(krate
));
1539 self.session
.time("resolve_report_errors", || self.report_errors(krate
));
1540 self.session
.time("resolve_postprocess", || self.crate_loader
.postprocess(krate
));
1544 pub fn traits_in_scope(
1546 current_trait
: Option
<Module
<'a
>>,
1547 parent_scope
: &ParentScope
<'a
>,
1548 ctxt
: SyntaxContext
,
1549 assoc_item
: Option
<(Symbol
, Namespace
)>,
1550 ) -> Vec
<TraitCandidate
> {
1551 let mut found_traits
= Vec
::new();
1553 if let Some(module
) = current_trait
{
1554 if self.trait_may_have_item(Some(module
), assoc_item
) {
1555 let def_id
= module
.def_id();
1556 found_traits
.push(TraitCandidate { def_id, import_ids: smallvec![] }
);
1560 self.visit_scopes(ScopeSet
::All(TypeNS
, false), parent_scope
, ctxt
, |this
, scope
, _
, _
| {
1562 Scope
::Module(module
, _
) => {
1563 this
.traits_in_module(module
, assoc_item
, &mut found_traits
);
1565 Scope
::StdLibPrelude
=> {
1566 if let Some(module
) = this
.prelude
{
1567 this
.traits_in_module(module
, assoc_item
, &mut found_traits
);
1570 Scope
::ExternPrelude
| Scope
::ToolPrelude
| Scope
::BuiltinTypes
=> {}
1571 _
=> unreachable
!(),
1579 fn traits_in_module(
1582 assoc_item
: Option
<(Symbol
, Namespace
)>,
1583 found_traits
: &mut Vec
<TraitCandidate
>,
1585 module
.ensure_traits(self);
1586 let traits
= module
.traits
.borrow();
1587 for (trait_name
, trait_binding
) in traits
.as_ref().unwrap().iter() {
1588 if self.trait_may_have_item(trait_binding
.module(), assoc_item
) {
1589 let def_id
= trait_binding
.res().def_id();
1590 let import_ids
= self.find_transitive_imports(&trait_binding
.kind
, *trait_name
);
1591 found_traits
.push(TraitCandidate { def_id, import_ids }
);
1596 // List of traits in scope is pruned on best effort basis. We reject traits not having an
1597 // associated item with the given name and namespace (if specified). This is a conservative
1598 // optimization, proper hygienic type-based resolution of associated items is done in typeck.
1599 // We don't reject trait aliases (`trait_module == None`) because we don't have access to their
1600 // associated items.
1601 fn trait_may_have_item(
1603 trait_module
: Option
<Module
<'a
>>,
1604 assoc_item
: Option
<(Symbol
, Namespace
)>,
1606 match (trait_module
, assoc_item
) {
1607 (Some(trait_module
), Some((name
, ns
))) => {
1608 self.resolutions(trait_module
).borrow().iter().any(|resolution
| {
1609 let (&BindingKey { ident: assoc_ident, ns: assoc_ns, .. }
, _
) = resolution
;
1610 assoc_ns
== ns
&& assoc_ident
.name
== name
1617 fn find_transitive_imports(
1619 mut kind
: &NameBindingKind
<'_
>,
1621 ) -> SmallVec
<[LocalDefId
; 1]> {
1622 let mut import_ids
= smallvec
![];
1623 while let NameBindingKind
::Import { import, binding, .. }
= kind
{
1624 let id
= self.local_def_id(import
.id
);
1625 self.maybe_unused_trait_imports
.insert(id
);
1626 self.add_to_glob_map(&import
, trait_name
);
1627 import_ids
.push(id
);
1628 kind
= &binding
.kind
;
1633 fn new_key(&mut self, ident
: Ident
, ns
: Namespace
) -> BindingKey
{
1634 let ident
= ident
.normalize_to_macros_2_0();
1635 let disambiguator
= if ident
.name
== kw
::Underscore
{
1636 self.underscore_disambiguator
+= 1;
1637 self.underscore_disambiguator
1641 BindingKey { ident, ns, disambiguator }
1644 fn resolutions(&mut self, module
: Module
<'a
>) -> &'a Resolutions
<'a
> {
1645 if module
.populate_on_access
.get() {
1646 module
.populate_on_access
.set(false);
1647 self.build_reduced_graph_external(module
);
1649 &module
.lazy_resolutions
1656 ) -> &'a RefCell
<NameResolution
<'a
>> {
1658 .resolutions(module
)
1661 .or_insert_with(|| self.arenas
.alloc_name_resolution())
1667 used_binding
: &'a NameBinding
<'a
>,
1668 is_lexical_scope
: bool
,
1670 if let Some((b2
, kind
)) = used_binding
.ambiguity
{
1671 self.ambiguity_errors
.push(AmbiguityError
{
1676 misc1
: AmbiguityErrorMisc
::None
,
1677 misc2
: AmbiguityErrorMisc
::None
,
1680 if let NameBindingKind
::Import { import, binding, ref used }
= used_binding
.kind
{
1681 // Avoid marking `extern crate` items that refer to a name from extern prelude,
1682 // but not introduce it, as used if they are accessed from lexical scope.
1683 if is_lexical_scope
{
1684 if let Some(entry
) = self.extern_prelude
.get(&ident
.normalize_to_macros_2_0()) {
1685 if let Some(crate_item
) = entry
.extern_crate_item
{
1686 if ptr
::eq(used_binding
, crate_item
) && !entry
.introduced_by_item
{
1693 import
.used
.set(true);
1694 self.used_imports
.insert(import
.id
);
1695 self.add_to_glob_map(&import
, ident
);
1696 self.record_use(ident
, binding
, false);
1701 fn add_to_glob_map(&mut self, import
: &Import
<'_
>, ident
: Ident
) {
1702 if import
.is_glob() {
1703 let def_id
= self.local_def_id(import
.id
);
1704 self.glob_map
.entry(def_id
).or_default().insert(ident
.name
);
1708 /// A generic scope visitor.
1709 /// Visits scopes in order to resolve some identifier in them or perform other actions.
1710 /// If the callback returns `Some` result, we stop visiting scopes and return it.
1713 scope_set
: ScopeSet
<'a
>,
1714 parent_scope
: &ParentScope
<'a
>,
1715 ctxt
: SyntaxContext
,
1716 mut visitor
: impl FnMut(
1719 /*use_prelude*/ bool
,
1723 // General principles:
1724 // 1. Not controlled (user-defined) names should have higher priority than controlled names
1725 // built into the language or standard library. This way we can add new names into the
1726 // language or standard library without breaking user code.
1727 // 2. "Closed set" below means new names cannot appear after the current resolution attempt.
1728 // Places to search (in order of decreasing priority):
1730 // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet
1731 // (open set, not controlled).
1732 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1733 // (open, not controlled).
1734 // 3. Extern prelude (open, the open part is from macro expansions, not controlled).
1735 // 4. Tool modules (closed, controlled right now, but not in the future).
1736 // 5. Standard library prelude (de-facto closed, controlled).
1737 // 6. Language prelude (closed, controlled).
1739 // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet
1740 // (open set, not controlled).
1741 // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1742 // (open, not controlled).
1743 // 3. Standard library prelude (de-facto closed, controlled).
1745 // 1-3. Derive helpers (open, not controlled). All ambiguities with other names
1746 // are currently reported as errors. They should be higher in priority than preludes
1747 // and probably even names in modules according to the "general principles" above. They
1748 // also should be subject to restricted shadowing because are effectively produced by
1749 // derives (you need to resolve the derive first to add helpers into scope), but they
1750 // should be available before the derive is expanded for compatibility.
1751 // It's mess in general, so we are being conservative for now.
1752 // 1-3. `macro_rules` (open, not controlled), loop through `macro_rules` scopes. Have higher
1753 // priority than prelude macros, but create ambiguities with macros in modules.
1754 // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
1755 // (open, not controlled). Have higher priority than prelude macros, but create
1756 // ambiguities with `macro_rules`.
1757 // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled).
1758 // 4a. User-defined prelude from macro-use
1759 // (open, the open part is from macro expansions, not controlled).
1760 // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled).
1761 // 4c. Standard library prelude (de-facto closed, controlled).
1762 // 6. Language prelude: builtin attributes (closed, controlled).
1764 let rust_2015
= ctxt
.edition() == Edition
::Edition2015
;
1765 let (ns
, macro_kind
, is_absolute_path
) = match scope_set
{
1766 ScopeSet
::All(ns
, _
) => (ns
, None
, false),
1767 ScopeSet
::AbsolutePath(ns
) => (ns
, None
, true),
1768 ScopeSet
::Macro(macro_kind
) => (MacroNS
, Some(macro_kind
), false),
1769 ScopeSet
::Late(ns
, ..) => (ns
, None
, false),
1771 let module
= match scope_set
{
1772 // Start with the specified module.
1773 ScopeSet
::Late(_
, module
, _
) => module
,
1774 // Jump out of trait or enum modules, they do not act as scopes.
1775 _
=> parent_scope
.module
.nearest_item_scope(),
1777 let mut scope
= match ns
{
1778 _
if is_absolute_path
=> Scope
::CrateRoot
,
1779 TypeNS
| ValueNS
=> Scope
::Module(module
, None
),
1780 MacroNS
=> Scope
::DeriveHelpers(parent_scope
.expansion
),
1782 let mut ctxt
= ctxt
.normalize_to_macros_2_0();
1783 let mut use_prelude
= !module
.no_implicit_prelude
;
1786 let visit
= match scope
{
1787 // Derive helpers are not in scope when resolving derives in the same container.
1788 Scope
::DeriveHelpers(expn_id
) => {
1789 !(expn_id
== parent_scope
.expansion
&& macro_kind
== Some(MacroKind
::Derive
))
1791 Scope
::DeriveHelpersCompat
=> true,
1792 Scope
::MacroRules(macro_rules_scope
) => {
1793 // Use "path compression" on `macro_rules` scope chains. This is an optimization
1794 // used to avoid long scope chains, see the comments on `MacroRulesScopeRef`.
1795 // As another consequence of this optimization visitors never observe invocation
1796 // scopes for macros that were already expanded.
1797 while let MacroRulesScope
::Invocation(invoc_id
) = macro_rules_scope
.get() {
1798 if let Some(next_scope
) = self.output_macro_rules_scopes
.get(&invoc_id
) {
1799 macro_rules_scope
.set(next_scope
.get());
1806 Scope
::CrateRoot
=> true,
1807 Scope
::Module(..) => true,
1808 Scope
::RegisteredAttrs
=> use_prelude
,
1809 Scope
::MacroUsePrelude
=> use_prelude
|| rust_2015
,
1810 Scope
::BuiltinAttrs
=> true,
1811 Scope
::ExternPrelude
=> use_prelude
|| is_absolute_path
,
1812 Scope
::ToolPrelude
=> use_prelude
,
1813 Scope
::StdLibPrelude
=> use_prelude
|| ns
== MacroNS
,
1814 Scope
::BuiltinTypes
=> true,
1818 if let break_result @
Some(..) = visitor(self, scope
, use_prelude
, ctxt
) {
1819 return break_result
;
1823 scope
= match scope
{
1824 Scope
::DeriveHelpers(LocalExpnId
::ROOT
) => Scope
::DeriveHelpersCompat
,
1825 Scope
::DeriveHelpers(expn_id
) => {
1826 // Derive helpers are not visible to code generated by bang or derive macros.
1827 let expn_data
= expn_id
.expn_data();
1828 match expn_data
.kind
{
1830 | ExpnKind
::Macro(MacroKind
::Bang
| MacroKind
::Derive
, _
) => {
1831 Scope
::DeriveHelpersCompat
1833 _
=> Scope
::DeriveHelpers(expn_data
.parent
.expect_local()),
1836 Scope
::DeriveHelpersCompat
=> Scope
::MacroRules(parent_scope
.macro_rules
),
1837 Scope
::MacroRules(macro_rules_scope
) => match macro_rules_scope
.get() {
1838 MacroRulesScope
::Binding(binding
) => {
1839 Scope
::MacroRules(binding
.parent_macro_rules_scope
)
1841 MacroRulesScope
::Invocation(invoc_id
) => {
1842 Scope
::MacroRules(self.invocation_parent_scopes
[&invoc_id
].macro_rules
)
1844 MacroRulesScope
::Empty
=> Scope
::Module(module
, None
),
1846 Scope
::CrateRoot
=> match ns
{
1848 ctxt
.adjust(ExpnId
::root());
1849 Scope
::ExternPrelude
1851 ValueNS
| MacroNS
=> break,
1853 Scope
::Module(module
, prev_lint_id
) => {
1854 use_prelude
= !module
.no_implicit_prelude
;
1855 let derive_fallback_lint_id
= match scope_set
{
1856 ScopeSet
::Late(.., lint_id
) => lint_id
,
1859 match self.hygienic_lexical_parent(module
, &mut ctxt
, derive_fallback_lint_id
) {
1860 Some((parent_module
, lint_id
)) => {
1861 Scope
::Module(parent_module
, lint_id
.or(prev_lint_id
))
1864 ctxt
.adjust(ExpnId
::root());
1866 TypeNS
=> Scope
::ExternPrelude
,
1867 ValueNS
=> Scope
::StdLibPrelude
,
1868 MacroNS
=> Scope
::RegisteredAttrs
,
1873 Scope
::RegisteredAttrs
=> Scope
::MacroUsePrelude
,
1874 Scope
::MacroUsePrelude
=> Scope
::StdLibPrelude
,
1875 Scope
::BuiltinAttrs
=> break, // nowhere else to search
1876 Scope
::ExternPrelude
if is_absolute_path
=> break,
1877 Scope
::ExternPrelude
=> Scope
::ToolPrelude
,
1878 Scope
::ToolPrelude
=> Scope
::StdLibPrelude
,
1879 Scope
::StdLibPrelude
=> match ns
{
1880 TypeNS
=> Scope
::BuiltinTypes
,
1881 ValueNS
=> break, // nowhere else to search
1882 MacroNS
=> Scope
::BuiltinAttrs
,
1884 Scope
::BuiltinTypes
=> break, // nowhere else to search
1891 /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
1892 /// More specifically, we proceed up the hierarchy of scopes and return the binding for
1893 /// `ident` in the first scope that defines it (or None if no scopes define it).
1895 /// A block's items are above its local variables in the scope hierarchy, regardless of where
1896 /// the items are defined in the block. For example,
1899 /// g(); // Since there are no local variables in scope yet, this resolves to the item.
1902 /// g(); // This resolves to the local variable `g` since it shadows the item.
1906 /// Invariant: This must only be called during main resolution, not during
1907 /// import resolution.
1908 fn resolve_ident_in_lexical_scope(
1912 parent_scope
: &ParentScope
<'a
>,
1913 record_used_id
: Option
<NodeId
>,
1916 ) -> Option
<LexicalScopeBinding
<'a
>> {
1917 assert
!(ns
== TypeNS
|| ns
== ValueNS
);
1918 let orig_ident
= ident
;
1919 if ident
.name
== kw
::Empty
{
1920 return Some(LexicalScopeBinding
::Res(Res
::Err
));
1922 let (general_span
, normalized_span
) = if ident
.name
== kw
::SelfUpper
{
1923 // FIXME(jseyfried) improve `Self` hygiene
1924 let empty_span
= ident
.span
.with_ctxt(SyntaxContext
::root());
1925 (empty_span
, empty_span
)
1926 } else if ns
== TypeNS
{
1927 let normalized_span
= ident
.span
.normalize_to_macros_2_0();
1928 (normalized_span
, normalized_span
)
1930 (ident
.span
.normalize_to_macro_rules(), ident
.span
.normalize_to_macros_2_0())
1932 ident
.span
= general_span
;
1933 let normalized_ident
= Ident { span: normalized_span, ..ident }
;
1935 // Walk backwards up the ribs in scope.
1936 let record_used
= record_used_id
.is_some();
1937 let mut module
= self.graph_root
;
1938 for i
in (0..ribs
.len()).rev() {
1939 debug
!("walk rib\n{:?}", ribs
[i
].bindings
);
1940 // Use the rib kind to determine whether we are resolving parameters
1941 // (macro 2.0 hygiene) or local variables (`macro_rules` hygiene).
1942 let rib_ident
= if ribs
[i
].kind
.contains_params() { normalized_ident }
else { ident }
;
1943 if let Some((original_rib_ident_def
, res
)) = ribs
[i
].bindings
.get_key_value(&rib_ident
)
1945 // The ident resolves to a type parameter or local variable.
1946 return Some(LexicalScopeBinding
::Res(self.validate_res_from_ribs(
1952 *original_rib_ident_def
,
1957 module
= match ribs
[i
].kind
{
1958 ModuleRibKind(module
) => module
,
1959 MacroDefinition(def
) if def
== self.macro_def(ident
.span
.ctxt()) => {
1960 // If an invocation of this macro created `ident`, give up on `ident`
1961 // and switch to `ident`'s source from the macro definition.
1962 ident
.span
.remove_mark();
1969 ModuleKind
::Block(..) => {}
// We can see through blocks
1973 let item
= self.resolve_ident_in_module_unadjusted(
1974 ModuleOrUniformRoot
::Module(module
),
1981 if let Ok(binding
) = item
{
1982 // The ident resolves to an item.
1983 return Some(LexicalScopeBinding
::Item(binding
));
1986 self.early_resolve_ident_in_lexical_scope(
1988 ScopeSet
::Late(ns
, module
, record_used_id
),
1995 .map(LexicalScopeBinding
::Item
)
1998 fn hygienic_lexical_parent(
2001 ctxt
: &mut SyntaxContext
,
2002 derive_fallback_lint_id
: Option
<NodeId
>,
2003 ) -> Option
<(Module
<'a
>, Option
<NodeId
>)> {
2004 if !module
.expansion
.outer_expn_is_descendant_of(*ctxt
) {
2005 return Some((self.expn_def_scope(ctxt
.remove_mark()), None
));
2008 if let ModuleKind
::Block(..) = module
.kind
{
2009 return Some((module
.parent
.unwrap().nearest_item_scope(), None
));
2012 // We need to support the next case under a deprecation warning
2015 // ---- begin: this comes from a proc macro derive
2016 // mod implementation_details {
2017 // // Note that `MyStruct` is not in scope here.
2018 // impl SomeTrait for MyStruct { ... }
2022 // So we have to fall back to the module's parent during lexical resolution in this case.
2023 if derive_fallback_lint_id
.is_some() {
2024 if let Some(parent
) = module
.parent
{
2025 // Inner module is inside the macro, parent module is outside of the macro.
2026 if module
.expansion
!= parent
.expansion
2027 && module
.expansion
.is_descendant_of(parent
.expansion
)
2029 // The macro is a proc macro derive
2030 if let Some(def_id
) = module
.expansion
.expn_data().macro_def_id
{
2031 let ext
= self.get_macro_by_def_id(def_id
);
2032 if ext
.builtin_name
.is_none()
2033 && ext
.macro_kind() == MacroKind
::Derive
2034 && parent
.expansion
.outer_expn_is_descendant_of(*ctxt
)
2036 return Some((parent
, derive_fallback_lint_id
));
2046 fn resolve_ident_in_module(
2048 module
: ModuleOrUniformRoot
<'a
>,
2051 parent_scope
: &ParentScope
<'a
>,
2054 ) -> Result
<&'a NameBinding
<'a
>, Determinacy
> {
2055 self.resolve_ident_in_module_ext(module
, ident
, ns
, parent_scope
, record_used
, path_span
)
2056 .map_err(|(determinacy
, _
)| determinacy
)
2059 fn resolve_ident_in_module_ext(
2061 module
: ModuleOrUniformRoot
<'a
>,
2064 parent_scope
: &ParentScope
<'a
>,
2067 ) -> Result
<&'a NameBinding
<'a
>, (Determinacy
, Weak
)> {
2068 let tmp_parent_scope
;
2069 let mut adjusted_parent_scope
= parent_scope
;
2071 ModuleOrUniformRoot
::Module(m
) => {
2072 if let Some(def
) = ident
.span
.normalize_to_macros_2_0_and_adjust(m
.expansion
) {
2074 ParentScope { module: self.expn_def_scope(def), ..*parent_scope }
;
2075 adjusted_parent_scope
= &tmp_parent_scope
;
2078 ModuleOrUniformRoot
::ExternPrelude
=> {
2079 ident
.span
.normalize_to_macros_2_0_and_adjust(ExpnId
::root());
2081 ModuleOrUniformRoot
::CrateRootAndExternPrelude
| ModuleOrUniformRoot
::CurrentScope
=> {
2085 self.resolve_ident_in_module_unadjusted_ext(
2089 adjusted_parent_scope
,
2096 fn resolve_crate_root(&mut self, ident
: Ident
) -> Module
<'a
> {
2097 debug
!("resolve_crate_root({:?})", ident
);
2098 let mut ctxt
= ident
.span
.ctxt();
2099 let mark
= if ident
.name
== kw
::DollarCrate
{
2100 // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
2101 // we don't want to pretend that the `macro_rules!` definition is in the `macro`
2102 // as described in `SyntaxContext::apply_mark`, so we ignore prepended opaque marks.
2103 // FIXME: This is only a guess and it doesn't work correctly for `macro_rules!`
2104 // definitions actually produced by `macro` and `macro` definitions produced by
2105 // `macro_rules!`, but at least such configurations are not stable yet.
2106 ctxt
= ctxt
.normalize_to_macro_rules();
2108 "resolve_crate_root: marks={:?}",
2109 ctxt
.marks().into_iter().map(|(i
, t
)| (i
.expn_data(), t
)).collect
::<Vec
<_
>>()
2111 let mut iter
= ctxt
.marks().into_iter().rev().peekable();
2112 let mut result
= None
;
2113 // Find the last opaque mark from the end if it exists.
2114 while let Some(&(mark
, transparency
)) = iter
.peek() {
2115 if transparency
== Transparency
::Opaque
{
2116 result
= Some(mark
);
2123 "resolve_crate_root: found opaque mark {:?} {:?}",
2125 result
.map(|r
| r
.expn_data())
2127 // Then find the last semi-transparent mark from the end if it exists.
2128 for (mark
, transparency
) in iter
{
2129 if transparency
== Transparency
::SemiTransparent
{
2130 result
= Some(mark
);
2136 "resolve_crate_root: found semi-transparent mark {:?} {:?}",
2138 result
.map(|r
| r
.expn_data())
2142 debug
!("resolve_crate_root: not DollarCrate");
2143 ctxt
= ctxt
.normalize_to_macros_2_0();
2144 ctxt
.adjust(ExpnId
::root())
2146 let module
= match mark
{
2147 Some(def
) => self.expn_def_scope(def
),
2150 "resolve_crate_root({:?}): found no mark (ident.span = {:?})",
2153 return self.graph_root
;
2156 let module
= self.expect_module(
2157 module
.opt_def_id().map_or(LOCAL_CRATE
, |def_id
| def_id
.krate
).as_def_id(),
2160 "resolve_crate_root({:?}): got module {:?} ({:?}) (ident.span = {:?})",
2169 fn resolve_self(&mut self, ctxt
: &mut SyntaxContext
, module
: Module
<'a
>) -> Module
<'a
> {
2170 let mut module
= self.expect_module(module
.nearest_parent_mod());
2171 while module
.span
.ctxt().normalize_to_macros_2_0() != *ctxt
{
2172 let parent
= module
.parent
.unwrap_or_else(|| self.expn_def_scope(ctxt
.remove_mark()));
2173 module
= self.expect_module(parent
.nearest_parent_mod());
2181 opt_ns
: Option
<Namespace
>, // `None` indicates a module path in import
2182 parent_scope
: &ParentScope
<'a
>,
2185 crate_lint
: CrateLint
,
2186 ) -> PathResult
<'a
> {
2187 self.resolve_path_with_ribs(
2198 fn resolve_path_with_ribs(
2201 opt_ns
: Option
<Namespace
>, // `None` indicates a module path in import
2202 parent_scope
: &ParentScope
<'a
>,
2205 crate_lint
: CrateLint
,
2206 ribs
: Option
<&PerNS
<Vec
<Rib
<'a
>>>>,
2207 ) -> PathResult
<'a
> {
2208 let mut module
= None
;
2209 let mut allow_super
= true;
2210 let mut second_binding
= None
;
2213 "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
2214 path_span={:?}, crate_lint={:?})",
2215 path
, opt_ns
, record_used
, path_span
, crate_lint
,
2218 for (i
, &Segment { ident, id, has_generic_args: _ }
) in path
.iter().enumerate() {
2219 debug
!("resolve_path ident {} {:?} {:?}", i
, ident
, id
);
2220 let record_segment_res
= |this
: &mut Self, res
| {
2222 if let Some(id
) = id
{
2223 if !this
.partial_res_map
.contains_key(&id
) {
2224 assert
!(id
!= ast
::DUMMY_NODE_ID
, "Trying to resolve dummy id");
2225 this
.record_partial_res(id
, PartialRes
::new(res
));
2231 let is_last
= i
== path
.len() - 1;
2232 let ns
= if is_last { opt_ns.unwrap_or(TypeNS) }
else { TypeNS }
;
2233 let name
= ident
.name
;
2235 allow_super
&= ns
== TypeNS
&& (name
== kw
::SelfLower
|| name
== kw
::Super
);
2238 if allow_super
&& name
== kw
::Super
{
2239 let mut ctxt
= ident
.span
.ctxt().normalize_to_macros_2_0();
2240 let self_module
= match i
{
2241 0 => Some(self.resolve_self(&mut ctxt
, parent_scope
.module
)),
2243 Some(ModuleOrUniformRoot
::Module(module
)) => Some(module
),
2247 if let Some(self_module
) = self_module
{
2248 if let Some(parent
) = self_module
.parent
{
2249 module
= Some(ModuleOrUniformRoot
::Module(
2250 self.resolve_self(&mut ctxt
, parent
),
2255 let msg
= "there are too many leading `super` keywords".to_string();
2256 return PathResult
::Failed
{
2260 is_error_from_last_segment
: false,
2264 if name
== kw
::SelfLower
{
2265 let mut ctxt
= ident
.span
.ctxt().normalize_to_macros_2_0();
2266 module
= Some(ModuleOrUniformRoot
::Module(
2267 self.resolve_self(&mut ctxt
, parent_scope
.module
),
2271 if name
== kw
::PathRoot
&& ident
.span
.rust_2018() {
2272 module
= Some(ModuleOrUniformRoot
::ExternPrelude
);
2275 if name
== kw
::PathRoot
&& ident
.span
.rust_2015() && self.session
.rust_2018() {
2276 // `::a::b` from 2015 macro on 2018 global edition
2277 module
= Some(ModuleOrUniformRoot
::CrateRootAndExternPrelude
);
2280 if name
== kw
::PathRoot
|| name
== kw
::Crate
|| name
== kw
::DollarCrate
{
2281 // `::a::b`, `crate::a::b` or `$crate::a::b`
2282 module
= Some(ModuleOrUniformRoot
::Module(self.resolve_crate_root(ident
)));
2288 // Report special messages for path segment keywords in wrong positions.
2289 if ident
.is_path_segment_keyword() && i
!= 0 {
2290 let name_str
= if name
== kw
::PathRoot
{
2291 "crate root".to_string()
2293 format
!("`{}`", name
)
2295 let label
= if i
== 1 && path
[0].ident
.name
== kw
::PathRoot
{
2296 format
!("global paths cannot start with {}", name_str
)
2298 format
!("{} in paths can only be used in start position", name_str
)
2300 return PathResult
::Failed
{
2304 is_error_from_last_segment
: false,
2308 enum FindBindingResult
<'a
> {
2309 Binding(Result
<&'a NameBinding
<'a
>, Determinacy
>),
2310 PathResult(PathResult
<'a
>),
2312 let find_binding_in_ns
= |this
: &mut Self, ns
| {
2313 let binding
= if let Some(module
) = module
{
2314 this
.resolve_ident_in_module(
2322 } else if ribs
.is_none() || opt_ns
.is_none() || opt_ns
== Some(MacroNS
) {
2323 let scopes
= ScopeSet
::All(ns
, opt_ns
.is_none());
2324 this
.early_resolve_ident_in_lexical_scope(
2333 let record_used_id
= if record_used
{
2334 crate_lint
.node_id().or(Some(CRATE_NODE_ID
))
2338 match this
.resolve_ident_in_lexical_scope(
2346 // we found a locally-imported or available item/module
2347 Some(LexicalScopeBinding
::Item(binding
)) => Ok(binding
),
2348 // we found a local variable or type param
2349 Some(LexicalScopeBinding
::Res(res
))
2350 if opt_ns
== Some(TypeNS
) || opt_ns
== Some(ValueNS
) =>
2352 record_segment_res(this
, res
);
2353 return FindBindingResult
::PathResult(PathResult
::NonModule(
2354 PartialRes
::with_unresolved_segments(res
, path
.len() - 1),
2357 _
=> Err(Determinacy
::determined(record_used
)),
2360 FindBindingResult
::Binding(binding
)
2362 let binding
= match find_binding_in_ns(self, ns
) {
2363 FindBindingResult
::PathResult(x
) => return x
,
2364 FindBindingResult
::Binding(binding
) => binding
,
2369 second_binding
= Some(binding
);
2371 let res
= binding
.res();
2372 let maybe_assoc
= opt_ns
!= Some(MacroNS
) && PathSource
::Type
.is_expected(res
);
2373 if let Some(next_module
) = binding
.module() {
2374 module
= Some(ModuleOrUniformRoot
::Module(next_module
));
2375 record_segment_res(self, res
);
2376 } else if res
== Res
::ToolMod
&& i
+ 1 != path
.len() {
2377 if binding
.is_import() {
2381 "cannot use a tool module through an import",
2383 .span_note(binding
.span
, "the tool module imported here")
2386 let res
= Res
::NonMacroAttr(NonMacroAttrKind
::Tool
);
2387 return PathResult
::NonModule(PartialRes
::new(res
));
2388 } else if res
== Res
::Err
{
2389 return PathResult
::NonModule(PartialRes
::new(Res
::Err
));
2390 } else if opt_ns
.is_some() && (is_last
|| maybe_assoc
) {
2391 self.lint_if_path_starts_with_module(
2397 return PathResult
::NonModule(PartialRes
::with_unresolved_segments(
2402 let label
= format
!(
2403 "`{}` is {} {}, not a module",
2409 return PathResult
::Failed
{
2413 is_error_from_last_segment
: is_last
,
2417 Err(Undetermined
) => return PathResult
::Indeterminate
,
2418 Err(Determined
) => {
2419 if let Some(ModuleOrUniformRoot
::Module(module
)) = module
{
2420 if opt_ns
.is_some() && !module
.is_normal() {
2421 return PathResult
::NonModule(PartialRes
::with_unresolved_segments(
2422 module
.res().unwrap(),
2427 let module_res
= match module
{
2428 Some(ModuleOrUniformRoot
::Module(module
)) => module
.res(),
2431 let (label
, suggestion
) = if module_res
== self.graph_root
.res() {
2432 let is_mod
= |res
| matches
!(res
, Res
::Def(DefKind
::Mod
, _
));
2433 // Don't look up import candidates if this is a speculative resolve
2434 let mut candidates
= if record_used
{
2435 self.lookup_import_candidates(ident
, TypeNS
, parent_scope
, is_mod
)
2439 candidates
.sort_by_cached_key(|c
| {
2440 (c
.path
.segments
.len(), pprust
::path_to_string(&c
.path
))
2442 if let Some(candidate
) = candidates
.get(0) {
2444 String
::from("unresolved import"),
2446 vec
![(ident
.span
, pprust
::path_to_string(&candidate
.path
))],
2447 String
::from("a similar path exists"),
2448 Applicability
::MaybeIncorrect
,
2451 } else if self.session
.edition() == Edition
::Edition2015
{
2452 (format
!("maybe a missing crate `{}`?", ident
), None
)
2454 (format
!("could not find `{}` in the crate root", ident
), None
)
2462 .map_or(false, |c
| c
.is_ascii_uppercase())
2464 // Check whether the name refers to an item in the value namespace.
2465 let suggestion
= if ribs
.is_some() {
2466 let match_span
= match self.resolve_ident_in_lexical_scope(
2472 &ribs
.unwrap()[ValueNS
],
2474 // Name matches a local variable. For example:
2477 // let Foo: &str = "";
2478 // println!("{}", Foo::Bar); // Name refers to local
2479 // // variable `Foo`.
2482 Some(LexicalScopeBinding
::Res(Res
::Local(id
))) => {
2483 Some(*self.pat_span_map
.get(&id
).unwrap())
2486 // Name matches item from a local name binding
2487 // created by `use` declaration. For example:
2489 // pub Foo: &str = "";
2493 // println!("{}", Foo::Bar); // Name refers to local
2494 // // binding `Foo`.
2497 Some(LexicalScopeBinding
::Item(name_binding
)) => {
2498 Some(name_binding
.span
)
2503 if let Some(span
) = match_span
{
2505 vec
![(span
, String
::from(""))],
2506 format
!("`{}` is defined here, but is not a type", ident
),
2507 Applicability
::MaybeIncorrect
,
2516 (format
!("use of undeclared type `{}`", ident
), suggestion
)
2519 format
!("use of undeclared crate or module `{}`", ident
),
2520 if ident
.name
== sym
::alloc
{
2524 "add `extern crate alloc` to use the `alloc` crate",
2526 Applicability
::MaybeIncorrect
,
2529 self.find_similarly_named_module_or_crate(
2531 &parent_scope
.module
,
2535 vec
![(ident
.span
, sugg
.to_string())],
2537 "there is a crate or module with a similar name",
2539 Applicability
::MaybeIncorrect
,
2546 let parent
= path
[i
- 1].ident
.name
;
2547 let parent
= match parent
{
2548 // ::foo is mounted at the crate root for 2015, and is the extern
2549 // prelude for 2018+
2550 kw
::PathRoot
if self.session
.edition() > Edition
::Edition2015
=> {
2551 "the list of imported crates".to_owned()
2553 kw
::PathRoot
| kw
::Crate
=> "the crate root".to_owned(),
2555 format
!("`{}`", parent
)
2559 let mut msg
= format
!("could not find `{}` in {}", ident
, parent
);
2560 if ns
== TypeNS
|| ns
== ValueNS
{
2561 let ns_to_try
= if ns
== TypeNS { ValueNS }
else { TypeNS }
;
2562 if let FindBindingResult
::Binding(Ok(binding
)) =
2563 find_binding_in_ns(self, ns_to_try
)
2565 let mut found
= |what
| {
2567 "expected {}, found {} `{}` in {}",
2574 if binding
.module().is_some() {
2577 match binding
.res() {
2578 def
::Res
::<NodeId
>::Def(kind
, id
) => found(kind
.descr(id
)),
2579 _
=> found(ns_to_try
.descr()),
2586 return PathResult
::Failed
{
2590 is_error_from_last_segment
: is_last
,
2596 self.lint_if_path_starts_with_module(crate_lint
, path
, path_span
, second_binding
);
2598 PathResult
::Module(match module
{
2599 Some(module
) => module
,
2600 None
if path
.is_empty() => ModuleOrUniformRoot
::CurrentScope
,
2601 _
=> span_bug
!(path_span
, "resolve_path: non-empty path `{:?}` has no module", path
),
2605 fn lint_if_path_starts_with_module(
2607 crate_lint
: CrateLint
,
2610 second_binding
: Option
<&NameBinding
<'_
>>,
2612 let (diag_id
, diag_span
) = match crate_lint
{
2613 CrateLint
::No
=> return,
2614 CrateLint
::SimplePath(id
) => (id
, path_span
),
2615 CrateLint
::UsePath { root_id, root_span }
=> (root_id
, root_span
),
2616 CrateLint
::QPathTrait { qpath_id, qpath_span }
=> (qpath_id
, qpath_span
),
2619 let first_name
= match path
.get(0) {
2620 // In the 2018 edition this lint is a hard error, so nothing to do
2621 Some(seg
) if seg
.ident
.span
.rust_2015() && self.session
.rust_2015() => seg
.ident
.name
,
2625 // We're only interested in `use` paths which should start with
2626 // `{{root}}` currently.
2627 if first_name
!= kw
::PathRoot
{
2632 // If this import looks like `crate::...` it's already good
2633 Some(Segment { ident, .. }
) if ident
.name
== kw
::Crate
=> return,
2634 // Otherwise go below to see if it's an extern crate
2636 // If the path has length one (and it's `PathRoot` most likely)
2637 // then we don't know whether we're gonna be importing a crate or an
2638 // item in our crate. Defer this lint to elsewhere
2642 // If the first element of our path was actually resolved to an
2643 // `ExternCrate` (also used for `crate::...`) then no need to issue a
2644 // warning, this looks all good!
2645 if let Some(binding
) = second_binding
{
2646 if let NameBindingKind
::Import { import, .. }
= binding
.kind
{
2647 // Careful: we still want to rewrite paths from renamed extern crates.
2648 if let ImportKind
::ExternCrate { source: None, .. }
= import
.kind
{
2654 let diag
= BuiltinLintDiagnostics
::AbsPathWithModule(diag_span
);
2655 self.lint_buffer
.buffer_lint_with_diagnostic(
2656 lint
::builtin
::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE
,
2659 "absolute paths must start with `self`, `super`, \
2660 `crate`, or an external crate name in the 2018 edition",
2665 // Validate a local resolution (from ribs).
2666 fn validate_res_from_ribs(
2673 original_rib_ident_def
: Ident
,
2674 all_ribs
: &[Rib
<'a
>],
2676 const CG_BUG_STR
: &str = "min_const_generics resolve check didn't stop compilation";
2677 debug
!("validate_res_from_ribs({:?})", res
);
2678 let ribs
= &all_ribs
[rib_index
+ 1..];
2680 // An invalid forward use of a generic parameter from a previous default.
2681 if let ForwardGenericParamBanRibKind
= all_ribs
[rib_index
].kind
{
2683 let res_error
= if rib_ident
.name
== kw
::SelfUpper
{
2684 ResolutionError
::SelfInGenericParamDefault
2686 ResolutionError
::ForwardDeclaredGenericParam
2688 self.report_error(span
, res_error
);
2690 assert_eq
!(res
, Res
::Err
);
2696 use ResolutionError
::*;
2697 let mut res_err
= None
;
2702 | ClosureOrAsyncRibKind
2704 | MacroDefinition(..)
2705 | ForwardGenericParamBanRibKind
=> {
2706 // Nothing to do. Continue.
2708 ItemRibKind(_
) | FnItemRibKind
| AssocItemRibKind
=> {
2709 // This was an attempt to access an upvar inside a
2710 // named function item. This is not allowed, so we
2713 // We don't immediately trigger a resolve error, because
2714 // we want certain other resolution errors (namely those
2715 // emitted for `ConstantItemRibKind` below) to take
2717 res_err
= Some(CannotCaptureDynamicEnvironmentInFnItem
);
2720 ConstantItemRibKind(_
, item
) => {
2721 // Still doesn't deal with upvars
2723 let (span
, resolution_error
) =
2724 if let Some((ident
, constant_item_kind
)) = item
{
2725 let kind_str
= match constant_item_kind
{
2726 ConstantItemKind
::Const
=> "const",
2727 ConstantItemKind
::Static
=> "static",
2731 AttemptToUseNonConstantValueInConstant(
2732 ident
, "let", kind_str
,
2738 AttemptToUseNonConstantValueInConstant(
2739 original_rib_ident_def
,
2745 self.report_error(span
, resolution_error
);
2749 ConstParamTyRibKind
=> {
2751 self.report_error(span
, ParamInTyOfConstParam(rib_ident
.name
));
2757 if let Some(res_err
) = res_err
{
2758 self.report_error(span
, res_err
);
2762 Res
::Def(DefKind
::TyParam
, _
) | Res
::SelfTy(..) => {
2764 let has_generic_params
: HasGenericParams
= match rib
.kind
{
2766 | ClosureOrAsyncRibKind
2769 | MacroDefinition(..)
2770 | ForwardGenericParamBanRibKind
=> {
2771 // Nothing to do. Continue.
2775 ConstantItemRibKind(trivial
, _
) => {
2776 let features
= self.session
.features_untracked();
2777 // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
2778 if !(trivial
|| features
.generic_const_exprs
) {
2779 // HACK(min_const_generics): If we encounter `Self` in an anonymous constant
2780 // we can't easily tell if it's generic at this stage, so we instead remember
2781 // this and then enforce the self type to be concrete later on.
2782 if let Res
::SelfTy(trait_def
, Some((impl_def
, _
))) = res
{
2783 res
= Res
::SelfTy(trait_def
, Some((impl_def
, true)));
2788 ResolutionError
::ParamInNonTrivialAnonConst
{
2789 name
: rib_ident
.name
,
2795 self.session
.delay_span_bug(span
, CG_BUG_STR
);
2803 // This was an attempt to use a type parameter outside its scope.
2804 ItemRibKind(has_generic_params
) => has_generic_params
,
2805 FnItemRibKind
=> HasGenericParams
::Yes
,
2806 ConstParamTyRibKind
=> {
2810 ResolutionError
::ParamInTyOfConstParam(rib_ident
.name
),
2820 ResolutionError
::GenericParamsFromOuterFunction(
2829 Res
::Def(DefKind
::ConstParam
, _
) => {
2830 let mut ribs
= ribs
.iter().peekable();
2831 if let Some(Rib { kind: FnItemRibKind, .. }
) = ribs
.peek() {
2832 // When declaring const parameters inside function signatures, the first rib
2833 // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
2834 // (spuriously) conflicting with the const param.
2839 let has_generic_params
= match rib
.kind
{
2841 | ClosureOrAsyncRibKind
2844 | MacroDefinition(..)
2845 | ForwardGenericParamBanRibKind
=> continue,
2847 ConstantItemRibKind(trivial
, _
) => {
2848 let features
= self.session
.features_untracked();
2849 // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
2850 if !(trivial
|| features
.generic_const_exprs
) {
2854 ResolutionError
::ParamInNonTrivialAnonConst
{
2855 name
: rib_ident
.name
,
2861 self.session
.delay_span_bug(span
, CG_BUG_STR
);
2868 ItemRibKind(has_generic_params
) => has_generic_params
,
2869 FnItemRibKind
=> HasGenericParams
::Yes
,
2870 ConstParamTyRibKind
=> {
2874 ResolutionError
::ParamInTyOfConstParam(rib_ident
.name
),
2881 // This was an attempt to use a const parameter outside its scope.
2885 ResolutionError
::GenericParamsFromOuterFunction(
2899 fn record_partial_res(&mut self, node_id
: NodeId
, resolution
: PartialRes
) {
2900 debug
!("(recording res) recording {:?} for {}", resolution
, node_id
);
2901 if let Some(prev_res
) = self.partial_res_map
.insert(node_id
, resolution
) {
2902 panic
!("path resolved multiple times ({:?} before, {:?} now)", prev_res
, resolution
);
2906 fn record_pat_span(&mut self, node
: NodeId
, span
: Span
) {
2907 debug
!("(recording pat) recording {:?} for {:?}", node
, span
);
2908 self.pat_span_map
.insert(node
, span
);
2911 fn is_accessible_from(&self, vis
: ty
::Visibility
, module
: Module
<'a
>) -> bool
{
2912 vis
.is_accessible_from(module
.nearest_parent_mod(), self)
2915 fn set_binding_parent_module(&mut self, binding
: &'a NameBinding
<'a
>, module
: Module
<'a
>) {
2916 if let Some(old_module
) = self.binding_parent_modules
.insert(PtrKey(binding
), module
) {
2917 if !ptr
::eq(module
, old_module
) {
2918 span_bug
!(binding
.span
, "parent module is reset for binding");
2923 fn disambiguate_macro_rules_vs_modularized(
2925 macro_rules
: &'a NameBinding
<'a
>,
2926 modularized
: &'a NameBinding
<'a
>,
2928 // Some non-controversial subset of ambiguities "modularized macro name" vs "macro_rules"
2929 // is disambiguated to mitigate regressions from macro modularization.
2930 // Scoping for `macro_rules` behaves like scoping for `let` at module level, in general.
2932 self.binding_parent_modules
.get(&PtrKey(macro_rules
)),
2933 self.binding_parent_modules
.get(&PtrKey(modularized
)),
2935 (Some(macro_rules
), Some(modularized
)) => {
2936 macro_rules
.nearest_parent_mod() == modularized
.nearest_parent_mod()
2937 && modularized
.is_ancestor_of(macro_rules
)
2943 fn report_errors(&mut self, krate
: &Crate
) {
2944 self.report_with_use_injections(krate
);
2946 for &(span_use
, span_def
) in &self.macro_expanded_macro_export_errors
{
2947 let msg
= "macro-expanded `macro_export` macros from the current crate \
2948 cannot be referred to by absolute paths";
2949 self.lint_buffer
.buffer_lint_with_diagnostic(
2950 lint
::builtin
::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS
,
2954 BuiltinLintDiagnostics
::MacroExpandedMacroExportsAccessedByAbsolutePaths(span_def
),
2958 for ambiguity_error
in &self.ambiguity_errors
{
2959 self.report_ambiguity_error(ambiguity_error
);
2962 let mut reported_spans
= FxHashSet
::default();
2963 for error
in &self.privacy_errors
{
2964 if reported_spans
.insert(error
.dedup_span
) {
2965 self.report_privacy_error(error
);
2970 fn report_with_use_injections(&mut self, krate
: &Crate
) {
2971 for UseError { mut err, candidates, def_id, instead, suggestion }
in
2972 self.use_injections
.drain(..)
2974 let (span
, found_use
) = if let Some(def_id
) = def_id
.as_local() {
2975 UsePlacementFinder
::check(krate
, self.def_id_to_node_id
[def_id
])
2979 if !candidates
.is_empty() {
2980 diagnostics
::show_candidates(
2989 } else if let Some((span
, msg
, sugg
, appl
)) = suggestion
{
2990 err
.span_suggestion(span
, msg
, sugg
, appl
);
2996 fn report_conflict
<'b
>(
3001 new_binding
: &NameBinding
<'b
>,
3002 old_binding
: &NameBinding
<'b
>,
3004 // Error on the second of two conflicting names
3005 if old_binding
.span
.lo() > new_binding
.span
.lo() {
3006 return self.report_conflict(parent
, ident
, ns
, old_binding
, new_binding
);
3009 let container
= match parent
.kind
{
3010 ModuleKind
::Def(kind
, _
, _
) => kind
.descr(parent
.def_id()),
3011 ModuleKind
::Block(..) => "block",
3014 let old_noun
= match old_binding
.is_import() {
3016 false => "definition",
3019 let new_participle
= match new_binding
.is_import() {
3025 (ident
.name
, self.session
.source_map().guess_head_span(new_binding
.span
));
3027 if let Some(s
) = self.name_already_seen
.get(&name
) {
3033 let old_kind
= match (ns
, old_binding
.module()) {
3034 (ValueNS
, _
) => "value",
3035 (MacroNS
, _
) => "macro",
3036 (TypeNS
, _
) if old_binding
.is_extern_crate() => "extern crate",
3037 (TypeNS
, Some(module
)) if module
.is_normal() => "module",
3038 (TypeNS
, Some(module
)) if module
.is_trait() => "trait",
3039 (TypeNS
, _
) => "type",
3042 let msg
= format
!("the name `{}` is defined multiple times", name
);
3044 let mut err
= match (old_binding
.is_extern_crate(), new_binding
.is_extern_crate()) {
3045 (true, true) => struct_span_err
!(self.session
, span
, E0259
, "{}", msg
),
3046 (true, _
) | (_
, true) => match new_binding
.is_import() && old_binding
.is_import() {
3047 true => struct_span_err
!(self.session
, span
, E0254
, "{}", msg
),
3048 false => struct_span_err
!(self.session
, span
, E0260
, "{}", msg
),
3050 _
=> match (old_binding
.is_import(), new_binding
.is_import()) {
3051 (false, false) => struct_span_err
!(self.session
, span
, E0428
, "{}", msg
),
3052 (true, true) => struct_span_err
!(self.session
, span
, E0252
, "{}", msg
),
3053 _
=> struct_span_err
!(self.session
, span
, E0255
, "{}", msg
),
3058 "`{}` must be defined only once in the {} namespace of this {}",
3064 err
.span_label(span
, format
!("`{}` re{} here", name
, new_participle
));
3066 self.session
.source_map().guess_head_span(old_binding
.span
),
3067 format
!("previous {} of the {} `{}` here", old_noun
, old_kind
, name
),
3070 // See https://github.com/rust-lang/rust/issues/32354
3071 use NameBindingKind
::Import
;
3072 let import
= match (&new_binding
.kind
, &old_binding
.kind
) {
3073 // If there are two imports where one or both have attributes then prefer removing the
3074 // import without attributes.
3075 (Import { import: new, .. }
, Import { import: old, .. }
)
3077 !new_binding
.span
.is_dummy()
3078 && !old_binding
.span
.is_dummy()
3079 && (new
.has_attributes
|| old
.has_attributes
)
3082 if old
.has_attributes
{
3083 Some((new
, new_binding
.span
, true))
3085 Some((old
, old_binding
.span
, true))
3088 // Otherwise prioritize the new binding.
3089 (Import { import, .. }
, other
) if !new_binding
.span
.is_dummy() => {
3090 Some((import
, new_binding
.span
, other
.is_import()))
3092 (other
, Import { import, .. }
) if !old_binding
.span
.is_dummy() => {
3093 Some((import
, old_binding
.span
, other
.is_import()))
3098 // Check if the target of the use for both bindings is the same.
3099 let duplicate
= new_binding
.res().opt_def_id() == old_binding
.res().opt_def_id();
3100 let has_dummy_span
= new_binding
.span
.is_dummy() || old_binding
.span
.is_dummy();
3102 self.extern_prelude
.get(&ident
).map_or(true, |entry
| entry
.introduced_by_item
);
3103 // Only suggest removing an import if both bindings are to the same def, if both spans
3104 // aren't dummy spans. Further, if both bindings are imports, then the ident must have
3105 // been introduced by an item.
3106 let should_remove_import
= duplicate
3108 && ((new_binding
.is_extern_crate() || old_binding
.is_extern_crate()) || from_item
);
3111 Some((import
, span
, true)) if should_remove_import
&& import
.is_nested() => {
3112 self.add_suggestion_for_duplicate_nested_use(&mut err
, import
, span
)
3114 Some((import
, _
, true)) if should_remove_import
&& !import
.is_glob() => {
3115 // Simple case - remove the entire import. Due to the above match arm, this can
3116 // only be a single use so just remove it entirely.
3117 err
.tool_only_span_suggestion(
3118 import
.use_span_with_attributes
,
3119 "remove unnecessary import",
3121 Applicability
::MaybeIncorrect
,
3124 Some((import
, span
, _
)) => {
3125 self.add_suggestion_for_rename_of_use(&mut err
, name
, import
, span
)
3131 self.name_already_seen
.insert(name
, span
);
3134 /// This function adds a suggestion to change the binding name of a new import that conflicts
3135 /// with an existing import.
3137 /// ```text,ignore (diagnostic)
3138 /// help: you can use `as` to change the binding name of the import
3140 /// LL | use foo::bar as other_bar;
3141 /// | ^^^^^^^^^^^^^^^^^^^^^
3143 fn add_suggestion_for_rename_of_use(
3145 err
: &mut DiagnosticBuilder
<'_
>,
3147 import
: &Import
<'_
>,
3150 let suggested_name
= if name
.as_str().chars().next().unwrap().is_uppercase() {
3151 format
!("Other{}", name
)
3153 format
!("other_{}", name
)
3156 let mut suggestion
= None
;
3158 ImportKind
::Single { type_ns_only: true, .. }
=> {
3159 suggestion
= Some(format
!("self as {}", suggested_name
))
3161 ImportKind
::Single { source, .. }
=> {
3163 source
.span
.hi().0.checked_sub(binding_span
.lo().0).map(|pos
| pos
as usize)
3165 if let Ok(snippet
) = self.session
.source_map().span_to_snippet(binding_span
) {
3166 if pos
<= snippet
.len() {
3167 suggestion
= Some(format
!(
3171 if snippet
.ends_with('
;'
) { ";" }
else { "" }
3177 ImportKind
::ExternCrate { source, target, .. }
=> {
3178 suggestion
= Some(format
!(
3179 "extern crate {} as {};",
3180 source
.unwrap_or(target
.name
),
3184 _
=> unreachable
!(),
3187 let rename_msg
= "you can use `as` to change the binding name of the import";
3188 if let Some(suggestion
) = suggestion
{
3189 err
.span_suggestion(
3193 Applicability
::MaybeIncorrect
,
3196 err
.span_label(binding_span
, rename_msg
);
3200 /// This function adds a suggestion to remove an unnecessary binding from an import that is
3201 /// nested. In the following example, this function will be invoked to remove the `a` binding
3202 /// in the second use statement:
3204 /// ```ignore (diagnostic)
3205 /// use issue_52891::a;
3206 /// use issue_52891::{d, a, e};
3209 /// The following suggestion will be added:
3211 /// ```ignore (diagnostic)
3212 /// use issue_52891::{d, a, e};
3213 /// ^-- help: remove unnecessary import
3216 /// If the nested use contains only one import then the suggestion will remove the entire
3219 /// It is expected that the provided import is nested - this isn't checked by the
3220 /// function. If this invariant is not upheld, this function's behaviour will be unexpected
3221 /// as characters expected by span manipulations won't be present.
3222 fn add_suggestion_for_duplicate_nested_use(
3224 err
: &mut DiagnosticBuilder
<'_
>,
3225 import
: &Import
<'_
>,
3228 assert
!(import
.is_nested());
3229 let message
= "remove unnecessary import";
3231 // Two examples will be used to illustrate the span manipulations we're doing:
3233 // - Given `use issue_52891::{d, a, e};` where `a` is a duplicate then `binding_span` is
3234 // `a` and `import.use_span` is `issue_52891::{d, a, e};`.
3235 // - Given `use issue_52891::{d, e, a};` where `a` is a duplicate then `binding_span` is
3236 // `a` and `import.use_span` is `issue_52891::{d, e, a};`.
3238 let (found_closing_brace
, span
) =
3239 find_span_of_binding_until_next_binding(self.session
, binding_span
, import
.use_span
);
3241 // If there was a closing brace then identify the span to remove any trailing commas from
3242 // previous imports.
3243 if found_closing_brace
{
3244 if let Some(span
) = extend_span_to_previous_binding(self.session
, span
) {
3245 err
.tool_only_span_suggestion(
3249 Applicability
::MaybeIncorrect
,
3252 // Remove the entire line if we cannot extend the span back, this indicates an
3253 // `issue_52891::{self}` case.
3254 err
.span_suggestion(
3255 import
.use_span_with_attributes
,
3258 Applicability
::MaybeIncorrect
,
3265 err
.span_suggestion(span
, message
, String
::new(), Applicability
::MachineApplicable
);
3268 fn extern_prelude_get(
3272 ) -> Option
<&'a NameBinding
<'a
>> {
3273 if ident
.is_path_segment_keyword() {
3274 // Make sure `self`, `super` etc produce an error when passed to here.
3277 self.extern_prelude
.get(&ident
.normalize_to_macros_2_0()).cloned().and_then(|entry
| {
3278 if let Some(binding
) = entry
.extern_crate_item
{
3279 if !speculative
&& entry
.introduced_by_item
{
3280 self.record_use(ident
, binding
, false);
3284 let crate_id
= if !speculative
{
3285 let Some(crate_id
) =
3286 self.crate_loader
.process_path_extern(ident
.name
, ident
.span
) else { return Some(self.dummy_binding); }
;
3289 self.crate_loader
.maybe_process_path_extern(ident
.name
)?
3291 let crate_root
= self.expect_module(crate_id
.as_def_id());
3293 (crate_root
, ty
::Visibility
::Public
, DUMMY_SP
, LocalExpnId
::ROOT
)
3294 .to_name_binding(self.arenas
),
3300 /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
3301 /// isn't something that can be returned because it can't be made to live that long,
3302 /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
3303 /// just that an error occurred.
3304 // FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
3305 pub fn resolve_str_path_error(
3311 ) -> Result
<(ast
::Path
, Res
), ()> {
3312 let path
= if path_str
.starts_with("::") {
3315 segments
: iter
::once(Ident
::with_dummy_span(kw
::PathRoot
))
3316 .chain(path_str
.split("::").skip(1).map(Ident
::from_str
))
3317 .map(|i
| self.new_ast_path_segment(i
))
3326 .map(Ident
::from_str
)
3327 .map(|i
| self.new_ast_path_segment(i
))
3332 let module
= self.expect_module(module_id
);
3333 let parent_scope
= &ParentScope
::module(module
, self);
3334 let res
= self.resolve_ast_path(&path
, ns
, parent_scope
).map_err(|_
| ())?
;
3338 // Resolve a path passed from rustdoc or HIR lowering.
3339 fn resolve_ast_path(
3343 parent_scope
: &ParentScope
<'a
>,
3344 ) -> Result
<Res
, (Span
, ResolutionError
<'a
>)> {
3345 match self.resolve_path(
3346 &Segment
::from_path(path
),
3353 PathResult
::Module(ModuleOrUniformRoot
::Module(module
)) => Ok(module
.res().unwrap()),
3354 PathResult
::NonModule(path_res
) if path_res
.unresolved_segments() == 0 => {
3355 Ok(path_res
.base_res())
3357 PathResult
::NonModule(..) => Err((
3359 ResolutionError
::FailedToResolve
{
3360 label
: String
::from("type-relative paths are not supported in this context"),
3364 PathResult
::Module(..) | PathResult
::Indeterminate
=> unreachable
!(),
3365 PathResult
::Failed { span, label, suggestion, .. }
=> {
3366 Err((span
, ResolutionError
::FailedToResolve { label, suggestion }
))
3371 fn new_ast_path_segment(&mut self, ident
: Ident
) -> ast
::PathSegment
{
3372 let mut seg
= ast
::PathSegment
::from_ident(ident
);
3373 seg
.id
= self.next_node_id();
3378 pub fn graph_root(&self) -> Module
<'a
> {
3383 pub fn all_macros(&self) -> &FxHashMap
<Symbol
, Res
> {
3387 /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
3389 pub fn opt_span(&self, def_id
: DefId
) -> Option
<Span
> {
3390 def_id
.as_local().map(|def_id
| self.definitions
.def_span(def_id
))
3393 /// Checks if an expression refers to a function marked with
3394 /// `#[rustc_legacy_const_generics]` and returns the argument index list
3395 /// from the attribute.
3396 pub fn legacy_const_generic_args(&mut self, expr
: &Expr
) -> Option
<Vec
<usize>> {
3397 if let ExprKind
::Path(None
, path
) = &expr
.kind
{
3398 // Don't perform legacy const generics rewriting if the path already
3399 // has generic arguments.
3400 if path
.segments
.last().unwrap().args
.is_some() {
3404 let partial_res
= self.partial_res_map
.get(&expr
.id
)?
;
3405 if partial_res
.unresolved_segments() != 0 {
3409 if let Res
::Def(def
::DefKind
::Fn
, def_id
) = partial_res
.base_res() {
3410 // We only support cross-crate argument rewriting. Uses
3411 // within the same crate should be updated to use the new
3412 // const generics style.
3413 if def_id
.is_local() {
3417 if let Some(v
) = self.legacy_const_generic_args
.get(&def_id
) {
3423 .item_attrs_untracked(def_id
, self.session
)
3425 .find(|a
| a
.has_name(sym
::rustc_legacy_const_generics
))?
;
3426 let mut ret
= Vec
::new();
3427 for meta
in attr
.meta_item_list()?
{
3428 match meta
.literal()?
.kind
{
3429 LitKind
::Int(a
, _
) => ret
.push(a
as usize),
3430 _
=> panic
!("invalid arg index"),
3433 // Cache the lookup to avoid parsing attributes for an iterm multiple times.
3434 self.legacy_const_generic_args
.insert(def_id
, Some(ret
.clone()));
3441 fn resolve_main(&mut self) {
3442 let module
= self.graph_root
;
3443 let ident
= Ident
::with_dummy_span(sym
::main
);
3444 let parent_scope
= &ParentScope
::module(module
, self);
3446 let name_binding
= match self.resolve_ident_in_module(
3447 ModuleOrUniformRoot
::Module(module
),
3454 Ok(name_binding
) => name_binding
,
3458 let res
= name_binding
.res();
3459 let is_import
= name_binding
.is_import();
3460 let span
= name_binding
.span
;
3461 if let Res
::Def(DefKind
::Fn
, _
) = res
{
3462 self.record_use(ident
, name_binding
, false);
3464 self.main_def
= Some(MainDefinition { res, is_import, span }
);
3468 fn names_to_string(names
: &[Symbol
]) -> String
{
3469 let mut result
= String
::new();
3470 for (i
, name
) in names
.iter().filter(|name
| **name
!= kw
::PathRoot
).enumerate() {
3472 result
.push_str("::");
3474 if Ident
::with_dummy_span(*name
).is_raw_guess() {
3475 result
.push_str("r#");
3477 result
.push_str(name
.as_str());
3482 fn path_names_to_string(path
: &Path
) -> String
{
3483 names_to_string(&path
.segments
.iter().map(|seg
| seg
.ident
.name
).collect
::<Vec
<_
>>())
3486 /// A somewhat inefficient routine to obtain the name of a module.
3487 fn module_to_string(module
: Module
<'_
>) -> Option
<String
> {
3488 let mut names
= Vec
::new();
3490 fn collect_mod(names
: &mut Vec
<Symbol
>, module
: Module
<'_
>) {
3491 if let ModuleKind
::Def(.., name
) = module
.kind
{
3492 if let Some(parent
) = module
.parent
{
3494 collect_mod(names
, parent
);
3497 names
.push(Symbol
::intern("<opaque>"));
3498 collect_mod(names
, module
.parent
.unwrap());
3501 collect_mod(&mut names
, module
);
3503 if names
.is_empty() {
3507 Some(names_to_string(&names
))
3510 #[derive(Copy, Clone, Debug)]
3512 /// Do not issue the lint.
3515 /// This lint applies to some arbitrary path; e.g., `impl ::foo::Bar`.
3516 /// In this case, we can take the span of that path.
3519 /// This lint comes from a `use` statement. In this case, what we
3520 /// care about really is the *root* `use` statement; e.g., if we
3521 /// have nested things like `use a::{b, c}`, we care about the
3523 UsePath { root_id: NodeId, root_span: Span }
,
3525 /// This is the "trait item" from a fully qualified path. For example,
3526 /// we might be resolving `X::Y::Z` from a path like `<T as X::Y>::Z`.
3527 /// The `path_span` is the span of the to the trait itself (`X::Y`).
3528 QPathTrait { qpath_id: NodeId, qpath_span: Span }
,
3532 fn node_id(&self) -> Option
<NodeId
> {
3534 CrateLint
::No
=> None
,
3535 CrateLint
::SimplePath(id
)
3536 | CrateLint
::UsePath { root_id: id, .. }
3537 | CrateLint
::QPathTrait { qpath_id: id, .. }
=> Some(id
),
3542 pub fn provide(providers
: &mut Providers
) {
3543 late
::lifetimes
::provide(providers
);