-// ignore-tidy-filelength
-
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
#![feature(crate_visibility_modifier)]
#![feature(label_break_value)]
+#![feature(mem_take)]
#![feature(nll)]
#![feature(rustc_diagnostic_macros)]
-#![cfg_attr(bootstrap, feature(type_alias_enum_variants))]
#![recursion_limit="256"]
-#![deny(rust_2018_idioms)]
-#![deny(internal)]
-#![deny(unused_lifetimes)]
-
pub use rustc::hir::def::{Namespace, PerNS};
-use GenericParameters::*;
-use RibKind::*;
-use smallvec::smallvec;
+use Determinacy::*;
-use rustc::hir::map::{Definitions, DefCollector};
+use rustc::hir::map::Definitions;
use rustc::hir::{self, PrimTy, Bool, Char, Float, Int, Uint, Str};
use rustc::middle::cstore::CrateStore;
use rustc::session::Session;
use rustc::lint;
-use rustc::hir::def::{
- self, DefKind, PartialRes, CtorKind, CtorOf, NonMacroAttrKind, ExportMap
-};
+use rustc::hir::def::{self, DefKind, PartialRes, CtorKind, CtorOf, NonMacroAttrKind, ExportMap};
use rustc::hir::def::Namespace::*;
use rustc::hir::def_id::{CRATE_DEF_INDEX, LOCAL_CRATE, DefId};
-use rustc::hir::{TraitCandidate, TraitMap, GlobMap};
-use rustc::ty::{self, DefIdTree};
+use rustc::hir::{TraitMap, GlobMap};
+use rustc::ty;
use rustc::util::nodemap::{NodeMap, NodeSet, FxHashMap, FxHashSet, DefIdMap};
-use rustc::{bug, span_bug};
+use rustc::span_bug;
use rustc_metadata::creader::CrateLoader;
use rustc_metadata::cstore::CStore;
-use syntax::source_map::SourceMap;
-use syntax::ext::hygiene::{Mark, Transparency, SyntaxContext};
+use syntax::ext::hygiene::{ExpnId, Transparency, SyntaxContext};
use syntax::ast::{self, Name, NodeId, Ident, FloatTy, IntTy, UintTy};
-use syntax::ext::base::{SyntaxExtension, SyntaxExtensionKind};
-use syntax::ext::base::Determinacy::{self, Determined, Undetermined};
-use syntax::ext::base::MacroKind;
+use syntax::ext::base::{SyntaxExtension, MacroKind, SpecialDerives};
use syntax::symbol::{Symbol, kw, sym};
-use syntax::util::lev_distance::find_best_match_for_name;
-use syntax::visit::{self, FnKind, Visitor};
+use syntax::visit::{self, Visitor};
use syntax::attr;
-use syntax::ast::{CRATE_NODE_ID, Arm, IsAsync, BindingMode, Block, Crate, Expr, ExprKind};
-use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, GenericParamKind, Generics};
-use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
-use syntax::ast::{Label, Local, Mutability, Pat, PatKind, Path};
-use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
-use syntax::ptr::P;
-use syntax::{span_err, struct_span_err, unwrap_or, walk_list};
+use syntax::ast::{CRATE_NODE_ID, Crate};
+use syntax::ast::{ItemKind, Path};
+use syntax::{struct_span_err, unwrap_or};
-use syntax_pos::{Span, DUMMY_SP, MultiSpan};
-use errors::{Applicability, DiagnosticBuilder, DiagnosticId};
+use syntax_pos::{Span, DUMMY_SP};
+use errors::{Applicability, DiagnosticBuilder};
use log::debug;
use std::cell::{Cell, RefCell};
-use std::{cmp, fmt, iter, mem, ptr};
+use std::{cmp, fmt, iter, ptr};
use std::collections::BTreeSet;
-use std::mem::replace;
use rustc_data_structures::ptr_key::PtrKey;
use rustc_data_structures::sync::Lrc;
-use smallvec::SmallVec;
+use diagnostics::{Suggestion, ImportSuggestion};
use diagnostics::{find_span_of_binding_until_next_binding, extend_span_to_previous_binding};
+use late::{PathSource, Rib, RibKind::*};
use resolve_imports::{ImportDirective, ImportDirectiveSubclass, NameResolution, ImportResolver};
-use macros::{InvocationData, LegacyBinding, ParentScope};
+use macros::{InvocationData, LegacyBinding, LegacyScope};
type Res = def::Res<NodeId>;
// registered before they are used.
mod error_codes;
mod diagnostics;
+mod late;
mod macros;
mod check_unused;
mod build_reduced_graph;
mod resolve_imports;
-fn is_known_tool(name: Name) -> bool {
- ["clippy", "rustfmt"].contains(&&*name.as_str())
-}
+const KNOWN_TOOLS: &[Name] = &[sym::clippy, sym::rustfmt];
enum Weak {
Yes,
No,
}
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum Determinacy {
+ Determined,
+ Undetermined,
+}
+
+impl Determinacy {
+ fn determined(determined: bool) -> Determinacy {
+ if determined { Determinacy::Determined } else { Determinacy::Undetermined }
+ }
+}
+
+/// A specific scope in which a name can be looked up.
+/// This enum is currently used only for early resolution (imports and macros),
+/// but not for late resolution yet.
+#[derive(Clone, Copy)]
+enum Scope<'a> {
+ DeriveHelpers,
+ MacroRules(LegacyScope<'a>),
+ CrateRoot,
+ Module(Module<'a>),
+ MacroUsePrelude,
+ BuiltinAttrs,
+ LegacyPluginHelpers,
+ ExternPrelude,
+ ToolPrelude,
+ StdLibPrelude,
+ BuiltinTypes,
+}
+
+/// Names from different contexts may want to visit different subsets of all specific scopes
+/// with different restrictions when looking up the resolution.
+/// This enum is currently used only for early resolution (imports and macros),
+/// but not for late resolution yet.
enum ScopeSet {
- Import(Namespace),
+ /// All scopes with the given namespace.
+ All(Namespace, /*is_import*/ bool),
+ /// Crate root, then extern prelude (used for mixed 2015-2018 mode in macros).
AbsolutePath(Namespace),
+ /// All scopes with macro namespace and the given macro kind restriction.
Macro(MacroKind),
- Module,
}
-/// A free importable items suggested in case of resolution failure.
-struct ImportSuggestion {
- did: Option<DefId>,
- path: Path,
-}
-
-/// A field or associated item from self type suggested in case of resolution failure.
-enum AssocSuggestion {
- Field,
- MethodWithSelf,
- AssocItem,
+/// Everything you need to know about a name's location to resolve it.
+/// Serves as a starting point for the scope visitor.
+/// This struct is currently used only for early resolution (imports and macros),
+/// but not for late resolution yet.
+#[derive(Clone, Debug)]
+pub struct ParentScope<'a> {
+ module: Module<'a>,
+ expansion: ExpnId,
+ legacy: LegacyScope<'a>,
+ derives: Vec<ast::Path>,
}
#[derive(Eq)]
name: Name,
origin: BTreeSet<Span>,
target: BTreeSet<Span>,
-}
-
-struct TypoSuggestion {
- candidate: Symbol,
-
- /// The kind of the binding ("crate", "module", etc.)
- kind: &'static str,
-
- /// An appropriate article to refer to the binding ("a", "an", etc.)
- article: &'static str,
+ could_be_path: bool
}
impl PartialOrd for BindingError {
}
}
-/// A vector of spans and replacements, a message and applicability.
-type Suggestion = (Vec<(Span, String)>, String, Applicability);
-
enum ResolutionError<'a> {
/// Error E0401: can't use type or const parameters from outer function.
GenericParamsFromOuterFunction(Res),
/// Error E0403: the name is already used for a type or const parameter in this generic
/// parameter list.
- NameAlreadyUsedInParameterList(Name, &'a Span),
+ NameAlreadyUsedInParameterList(Name, Span),
/// Error E0407: method is not a member of trait.
MethodNotMemberOfTrait(Name, &'a str),
/// Error E0437: type is not a member of trait.
ConstParamDependentOnTypeParam,
}
-/// Combines an error with provided span and emits it.
-///
-/// This takes the error provided, combines it with the span and any additional spans inside the
-/// error and emits it.
-fn resolve_error<'sess, 'a>(resolver: &'sess Resolver<'_>,
- span: Span,
- resolution_error: ResolutionError<'a>) {
- resolve_struct_error(resolver, span, resolution_error).emit();
-}
-
-fn resolve_struct_error<'sess, 'a>(resolver: &'sess Resolver<'_>,
- span: Span,
- resolution_error: ResolutionError<'a>)
- -> DiagnosticBuilder<'sess> {
- match resolution_error {
- ResolutionError::GenericParamsFromOuterFunction(outer_res) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0401,
- "can't use generic parameters from outer function",
- );
- err.span_label(span, format!("use of generic parameter from outer function"));
-
- let cm = resolver.session.source_map();
- match outer_res {
- Res::SelfTy(maybe_trait_defid, maybe_impl_defid) => {
- if let Some(impl_span) = maybe_impl_defid.and_then(|def_id| {
- resolver.definitions.opt_span(def_id)
- }) {
- err.span_label(
- reduce_impl_span_to_impl_keyword(cm, impl_span),
- "`Self` type implicitly declared here, by this `impl`",
- );
- }
- match (maybe_trait_defid, maybe_impl_defid) {
- (Some(_), None) => {
- err.span_label(span, "can't use `Self` here");
- }
- (_, Some(_)) => {
- err.span_label(span, "use a type here instead");
- }
- (None, None) => bug!("`impl` without trait nor type?"),
- }
- return err;
- },
- Res::Def(DefKind::TyParam, def_id) => {
- if let Some(span) = resolver.definitions.opt_span(def_id) {
- err.span_label(span, "type parameter from outer function");
- }
- }
- Res::Def(DefKind::ConstParam, def_id) => {
- if let Some(span) = resolver.definitions.opt_span(def_id) {
- err.span_label(span, "const parameter from outer function");
- }
- }
- _ => {
- bug!("GenericParamsFromOuterFunction should only be used with Res::SelfTy, \
- DefKind::TyParam");
- }
- }
-
- // Try to retrieve the span of the function signature and generate a new message with
- // a local type or const parameter.
- let sugg_msg = &format!("try using a local generic parameter instead");
- if let Some((sugg_span, new_snippet)) = cm.generate_local_type_param_snippet(span) {
- // Suggest the modification to the user
- err.span_suggestion(
- sugg_span,
- sugg_msg,
- new_snippet,
- Applicability::MachineApplicable,
- );
- } else if let Some(sp) = cm.generate_fn_name_span(span) {
- err.span_label(sp,
- format!("try adding a local generic parameter in this method instead"));
- } else {
- err.help(&format!("try using a local generic parameter instead"));
- }
-
- err
- }
- ResolutionError::NameAlreadyUsedInParameterList(name, first_use_span) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0403,
- "the name `{}` is already used for a generic \
- parameter in this list of generic parameters",
- name);
- err.span_label(span, "already used");
- err.span_label(first_use_span.clone(), format!("first use of `{}`", name));
- err
- }
- ResolutionError::MethodNotMemberOfTrait(method, trait_) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0407,
- "method `{}` is not a member of trait `{}`",
- method,
- trait_);
- err.span_label(span, format!("not a member of trait `{}`", trait_));
- err
- }
- ResolutionError::TypeNotMemberOfTrait(type_, trait_) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0437,
- "type `{}` is not a member of trait `{}`",
- type_,
- trait_);
- err.span_label(span, format!("not a member of trait `{}`", trait_));
- err
- }
- ResolutionError::ConstNotMemberOfTrait(const_, trait_) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0438,
- "const `{}` is not a member of trait `{}`",
- const_,
- trait_);
- err.span_label(span, format!("not a member of trait `{}`", trait_));
- err
- }
- ResolutionError::VariableNotBoundInPattern(binding_error) => {
- let target_sp = binding_error.target.iter().cloned().collect::<Vec<_>>();
- let msp = MultiSpan::from_spans(target_sp.clone());
- let msg = format!("variable `{}` is not bound in all patterns", binding_error.name);
- let mut err = resolver.session.struct_span_err_with_code(
- msp,
- &msg,
- DiagnosticId::Error("E0408".into()),
- );
- for sp in target_sp {
- err.span_label(sp, format!("pattern doesn't bind `{}`", binding_error.name));
- }
- let origin_sp = binding_error.origin.iter().cloned();
- for sp in origin_sp {
- err.span_label(sp, "variable not in all patterns");
- }
- err
- }
- ResolutionError::VariableBoundWithDifferentMode(variable_name,
- first_binding_span) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0409,
- "variable `{}` is bound in inconsistent \
- ways within the same match arm",
- variable_name);
- err.span_label(span, "bound in different ways");
- err.span_label(first_binding_span, "first binding");
- err
- }
- ResolutionError::IdentifierBoundMoreThanOnceInParameterList(identifier) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0415,
- "identifier `{}` is bound more than once in this parameter list",
- identifier);
- err.span_label(span, "used as parameter more than once");
- err
- }
- ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(identifier) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0416,
- "identifier `{}` is bound more than once in the same pattern",
- identifier);
- err.span_label(span, "used in a pattern more than once");
- err
- }
- ResolutionError::UndeclaredLabel(name, lev_candidate) => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0426,
- "use of undeclared label `{}`",
- name);
- if let Some(lev_candidate) = lev_candidate {
- err.span_suggestion(
- span,
- "a label with a similar name exists in this scope",
- lev_candidate.to_string(),
- Applicability::MaybeIncorrect,
- );
- } else {
- err.span_label(span, format!("undeclared label `{}`", name));
- }
- err
- }
- ResolutionError::SelfImportsOnlyAllowedWithin => {
- struct_span_err!(resolver.session,
- span,
- E0429,
- "{}",
- "`self` imports are only allowed within a { } list")
- }
- ResolutionError::SelfImportCanOnlyAppearOnceInTheList => {
- let mut err = struct_span_err!(resolver.session, span, E0430,
- "`self` import can only appear once in an import list");
- err.span_label(span, "can only appear once in an import list");
- err
- }
- ResolutionError::SelfImportOnlyInImportListWithNonEmptyPrefix => {
- let mut err = struct_span_err!(resolver.session, span, E0431,
- "`self` import can only appear in an import list with \
- a non-empty prefix");
- err.span_label(span, "can only appear in an import list with a non-empty prefix");
- err
- }
- ResolutionError::FailedToResolve { label, suggestion } => {
- let mut err = struct_span_err!(resolver.session, span, E0433,
- "failed to resolve: {}", &label);
- err.span_label(span, label);
-
- if let Some((suggestions, msg, applicability)) = suggestion {
- err.multipart_suggestion(&msg, suggestions, applicability);
- }
-
- err
- }
- ResolutionError::CannotCaptureDynamicEnvironmentInFnItem => {
- let mut err = struct_span_err!(resolver.session,
- span,
- E0434,
- "{}",
- "can't capture dynamic environment in a fn item");
- err.help("use the `|| { ... }` closure form instead");
- err
- }
- ResolutionError::AttemptToUseNonConstantValueInConstant => {
- let mut err = struct_span_err!(resolver.session, span, E0435,
- "attempt to use a non-constant value in a constant");
- err.span_label(span, "non-constant value");
- err
- }
- ResolutionError::BindingShadowsSomethingUnacceptable(what_binding, name, binding) => {
- let shadows_what = binding.descr();
- let mut err = struct_span_err!(resolver.session, span, E0530, "{}s cannot shadow {}s",
- what_binding, shadows_what);
- err.span_label(span, format!("cannot be named the same as {} {}",
- binding.article(), shadows_what));
- let participle = if binding.is_import() { "imported" } else { "defined" };
- let msg = format!("the {} `{}` is {} here", shadows_what, name, participle);
- err.span_label(binding.span, msg);
- err
- }
- ResolutionError::ForwardDeclaredTyParam => {
- let mut err = struct_span_err!(resolver.session, span, E0128,
- "type parameters with a default cannot use \
- forward declared identifiers");
- err.span_label(
- span, "defaulted type parameters cannot be forward declared".to_string());
- err
- }
- ResolutionError::ConstParamDependentOnTypeParam => {
- let mut err = struct_span_err!(
- resolver.session,
- span,
- E0671,
- "const parameters cannot depend on type parameters"
- );
- err.span_label(span, format!("const parameter depends on type parameter"));
- err
- }
- }
-}
-
-/// Adjust the impl span so that just the `impl` keyword is taken by removing
-/// everything after `<` (`"impl<T> Iterator for A<T> {}" -> "impl"`) and
-/// everything after the first whitespace (`"impl Iterator for A" -> "impl"`).
-///
-/// *Attention*: the method used is very fragile since it essentially duplicates the work of the
-/// parser. If you need to use this function or something similar, please consider updating the
-/// `source_map` functions and this function to something more robust.
-fn reduce_impl_span_to_impl_keyword(cm: &SourceMap, impl_span: Span) -> Span {
- let impl_span = cm.span_until_char(impl_span, '<');
- let impl_span = cm.span_until_whitespace(impl_span);
- impl_span
-}
-
-#[derive(Copy, Clone, Debug)]
-struct BindingInfo {
- span: Span,
- binding_mode: BindingMode,
-}
-
-/// Map from the name in a pattern to its binding mode.
-type BindingMap = FxHashMap<Ident, BindingInfo>;
-
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
-enum PatternSource {
- Match,
- Let,
- For,
- FnParam,
-}
-
-impl PatternSource {
- fn descr(self) -> &'static str {
- match self {
- PatternSource::Match => "match binding",
- PatternSource::Let => "let binding",
- PatternSource::For => "for binding",
- PatternSource::FnParam => "function parameter",
- }
- }
-}
-
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
-enum AliasPossibility {
- No,
- Maybe,
-}
-
-#[derive(Copy, Clone, Debug)]
-enum PathSource<'a> {
- // Type paths `Path`.
- Type,
- // Trait paths in bounds or impls.
- Trait(AliasPossibility),
- // Expression paths `path`, with optional parent context.
- Expr(Option<&'a Expr>),
- // Paths in path patterns `Path`.
- Pat,
- // Paths in struct expressions and patterns `Path { .. }`.
- Struct,
- // Paths in tuple struct patterns `Path(..)`.
- TupleStruct,
- // `m::A::B` in `<T as m::A>::B::C`.
- TraitItem(Namespace),
- // Path in `pub(path)`
- Visibility,
-}
-
-impl<'a> PathSource<'a> {
- fn namespace(self) -> Namespace {
- match self {
- PathSource::Type | PathSource::Trait(_) | PathSource::Struct |
- PathSource::Visibility => TypeNS,
- PathSource::Expr(..) | PathSource::Pat | PathSource::TupleStruct => ValueNS,
- PathSource::TraitItem(ns) => ns,
- }
- }
-
- fn global_by_default(self) -> bool {
- match self {
- PathSource::Visibility => true,
- PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
- PathSource::Struct | PathSource::TupleStruct |
- PathSource::Trait(_) | PathSource::TraitItem(..) => false,
- }
- }
-
- fn defer_to_typeck(self) -> bool {
- match self {
- PathSource::Type | PathSource::Expr(..) | PathSource::Pat |
- PathSource::Struct | PathSource::TupleStruct => true,
- PathSource::Trait(_) | PathSource::TraitItem(..) |
- PathSource::Visibility => false,
- }
- }
-
- fn descr_expected(self) -> &'static str {
- match self {
- PathSource::Type => "type",
- PathSource::Trait(_) => "trait",
- PathSource::Pat => "unit struct/variant or constant",
- PathSource::Struct => "struct, variant or union type",
- PathSource::TupleStruct => "tuple struct/variant",
- PathSource::Visibility => "module",
- PathSource::TraitItem(ns) => match ns {
- TypeNS => "associated type",
- ValueNS => "method or associated constant",
- MacroNS => bug!("associated macro"),
- },
- PathSource::Expr(parent) => match parent.map(|p| &p.node) {
- // "function" here means "anything callable" rather than `DefKind::Fn`,
- // this is not precise but usually more helpful than just "value".
- Some(&ExprKind::Call(..)) => "function",
- _ => "value",
- },
- }
- }
-
- fn is_expected(self, res: Res) -> bool {
- match self {
- PathSource::Type => match res {
- Res::Def(DefKind::Struct, _)
- | Res::Def(DefKind::Union, _)
- | Res::Def(DefKind::Enum, _)
- | Res::Def(DefKind::Trait, _)
- | Res::Def(DefKind::TraitAlias, _)
- | Res::Def(DefKind::TyAlias, _)
- | Res::Def(DefKind::AssocTy, _)
- | Res::PrimTy(..)
- | Res::Def(DefKind::TyParam, _)
- | Res::SelfTy(..)
- | Res::Def(DefKind::Existential, _)
- | Res::Def(DefKind::ForeignTy, _) => true,
- _ => false,
- },
- PathSource::Trait(AliasPossibility::No) => match res {
- Res::Def(DefKind::Trait, _) => true,
- _ => false,
- },
- PathSource::Trait(AliasPossibility::Maybe) => match res {
- Res::Def(DefKind::Trait, _) => true,
- Res::Def(DefKind::TraitAlias, _) => true,
- _ => false,
- },
- PathSource::Expr(..) => match res {
- Res::Def(DefKind::Ctor(_, CtorKind::Const), _)
- | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _)
- | Res::Def(DefKind::Const, _)
- | Res::Def(DefKind::Static, _)
- | Res::Local(..)
- | Res::Def(DefKind::Fn, _)
- | Res::Def(DefKind::Method, _)
- | Res::Def(DefKind::AssocConst, _)
- | Res::SelfCtor(..)
- | Res::Def(DefKind::ConstParam, _) => true,
- _ => false,
- },
- PathSource::Pat => match res {
- Res::Def(DefKind::Ctor(_, CtorKind::Const), _) |
- Res::Def(DefKind::Const, _) | Res::Def(DefKind::AssocConst, _) |
- Res::SelfCtor(..) => true,
- _ => false,
- },
- PathSource::TupleStruct => match res {
- Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) | Res::SelfCtor(..) => true,
- _ => false,
- },
- PathSource::Struct => match res {
- Res::Def(DefKind::Struct, _)
- | Res::Def(DefKind::Union, _)
- | Res::Def(DefKind::Variant, _)
- | Res::Def(DefKind::TyAlias, _)
- | Res::Def(DefKind::AssocTy, _)
- | Res::SelfTy(..) => true,
- _ => false,
- },
- PathSource::TraitItem(ns) => match res {
- Res::Def(DefKind::AssocConst, _)
- | Res::Def(DefKind::Method, _) if ns == ValueNS => true,
- Res::Def(DefKind::AssocTy, _) if ns == TypeNS => true,
- _ => false,
- },
- PathSource::Visibility => match res {
- Res::Def(DefKind::Mod, _) => true,
- _ => false,
- },
- }
- }
-
- fn error_code(self, has_unexpected_resolution: bool) -> &'static str {
- __diagnostic_used!(E0404);
- __diagnostic_used!(E0405);
- __diagnostic_used!(E0412);
- __diagnostic_used!(E0422);
- __diagnostic_used!(E0423);
- __diagnostic_used!(E0425);
- __diagnostic_used!(E0531);
- __diagnostic_used!(E0532);
- __diagnostic_used!(E0573);
- __diagnostic_used!(E0574);
- __diagnostic_used!(E0575);
- __diagnostic_used!(E0576);
- __diagnostic_used!(E0577);
- __diagnostic_used!(E0578);
- match (self, has_unexpected_resolution) {
- (PathSource::Trait(_), true) => "E0404",
- (PathSource::Trait(_), false) => "E0405",
- (PathSource::Type, true) => "E0573",
- (PathSource::Type, false) => "E0412",
- (PathSource::Struct, true) => "E0574",
- (PathSource::Struct, false) => "E0422",
- (PathSource::Expr(..), true) => "E0423",
- (PathSource::Expr(..), false) => "E0425",
- (PathSource::Pat, true) | (PathSource::TupleStruct, true) => "E0532",
- (PathSource::Pat, false) | (PathSource::TupleStruct, false) => "E0531",
- (PathSource::TraitItem(..), true) => "E0575",
- (PathSource::TraitItem(..), false) => "E0576",
- (PathSource::Visibility, true) => "E0577",
- (PathSource::Visibility, false) => "E0578",
- }
- }
-}
-
// A minimal representation of a path segment. We use this in resolve because
// we synthesize 'path segments' which don't have the rest of an AST or HIR
// `PathSegment`.
}
}
-/// Walks the whole crate in DFS order, visiting each item, resolving names as it goes.
-impl<'a, 'tcx> Visitor<'tcx> for Resolver<'a> {
- fn visit_item(&mut self, item: &'tcx Item) {
- self.resolve_item(item);
- }
- fn visit_arm(&mut self, arm: &'tcx Arm) {
- self.resolve_arm(arm);
- }
- fn visit_block(&mut self, block: &'tcx Block) {
- self.resolve_block(block);
- }
- fn visit_anon_const(&mut self, constant: &'tcx ast::AnonConst) {
- debug!("visit_anon_const {:?}", constant);
- self.with_constant_rib(|this| {
- visit::walk_anon_const(this, constant);
- });
- }
- fn visit_expr(&mut self, expr: &'tcx Expr) {
- self.resolve_expr(expr, None);
- }
- fn visit_local(&mut self, local: &'tcx Local) {
- self.resolve_local(local);
- }
- fn visit_ty(&mut self, ty: &'tcx Ty) {
- match ty.node {
- TyKind::Path(ref qself, ref path) => {
- self.smart_resolve_path(ty.id, qself.as_ref(), path, PathSource::Type);
- }
- TyKind::ImplicitSelf => {
- let self_ty = Ident::with_empty_ctxt(kw::SelfUpper);
- let res = self.resolve_ident_in_lexical_scope(self_ty, TypeNS, Some(ty.id), ty.span)
- .map_or(Res::Err, |d| d.res());
- self.record_partial_res(ty.id, PartialRes::new(res));
- }
- _ => (),
- }
- visit::walk_ty(self, ty);
- }
- fn visit_poly_trait_ref(&mut self,
- tref: &'tcx ast::PolyTraitRef,
- m: &'tcx ast::TraitBoundModifier) {
- self.smart_resolve_path(tref.trait_ref.ref_id, None,
- &tref.trait_ref.path, PathSource::Trait(AliasPossibility::Maybe));
- visit::walk_poly_trait_ref(self, tref, m);
- }
- fn visit_foreign_item(&mut self, foreign_item: &'tcx ForeignItem) {
- let generic_params = match foreign_item.node {
- ForeignItemKind::Fn(_, ref generics) => {
- HasGenericParams(generics, ItemRibKind)
- }
- ForeignItemKind::Static(..) => NoGenericParams,
- ForeignItemKind::Ty => NoGenericParams,
- ForeignItemKind::Macro(..) => NoGenericParams,
- };
- self.with_generic_param_rib(generic_params, |this| {
- visit::walk_foreign_item(this, foreign_item);
- });
- }
- fn visit_fn(&mut self,
- function_kind: FnKind<'tcx>,
- declaration: &'tcx FnDecl,
- _: Span,
- _: NodeId)
- {
- debug!("(resolving function) entering function");
- let rib_kind = match function_kind {
- FnKind::ItemFn(..) => FnItemRibKind,
- FnKind::Method(..) => AssocItemRibKind,
- FnKind::Closure(_) => NormalRibKind,
- };
-
- // Create a value rib for the function.
- self.ribs[ValueNS].push(Rib::new(rib_kind));
-
- // Create a label rib for the function.
- self.label_ribs.push(Rib::new(rib_kind));
-
- // Add each argument to the rib.
- let mut bindings_list = FxHashMap::default();
- for argument in &declaration.inputs {
- self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
-
- self.visit_ty(&argument.ty);
-
- debug!("(resolving function) recorded argument");
- }
- visit::walk_fn_ret_ty(self, &declaration.output);
-
- // Resolve the function body, potentially inside the body of an async closure
- match function_kind {
- FnKind::ItemFn(.., body) |
- FnKind::Method(.., body) => {
- self.visit_block(body);
- }
- FnKind::Closure(body) => {
- self.visit_expr(body);
- }
- };
-
- debug!("(resolving function) leaving function");
-
- self.label_ribs.pop();
- self.ribs[ValueNS].pop();
- }
-
- fn visit_generics(&mut self, generics: &'tcx Generics) {
- // For type parameter defaults, we have to ban access
- // to following type parameters, as the InternalSubsts can only
- // provide previous type parameters as they're built. We
- // put all the parameters on the ban list and then remove
- // them one by one as they are processed and become available.
- let mut default_ban_rib = Rib::new(ForwardTyParamBanRibKind);
- let mut found_default = false;
- default_ban_rib.bindings.extend(generics.params.iter()
- .filter_map(|param| match param.kind {
- GenericParamKind::Const { .. } |
- GenericParamKind::Lifetime { .. } => None,
- GenericParamKind::Type { ref default, .. } => {
- found_default |= default.is_some();
- if found_default {
- Some((Ident::with_empty_ctxt(param.ident.name), Res::Err))
- } else {
- None
- }
- }
- }));
-
- // We also ban access to type parameters for use as the types of const parameters.
- let mut const_ty_param_ban_rib = Rib::new(TyParamAsConstParamTy);
- const_ty_param_ban_rib.bindings.extend(generics.params.iter()
- .filter(|param| {
- if let GenericParamKind::Type { .. } = param.kind {
- true
- } else {
- false
- }
- })
- .map(|param| (Ident::with_empty_ctxt(param.ident.name), Res::Err)));
-
- for param in &generics.params {
- match param.kind {
- GenericParamKind::Lifetime { .. } => self.visit_generic_param(param),
- GenericParamKind::Type { ref default, .. } => {
- for bound in ¶m.bounds {
- self.visit_param_bound(bound);
- }
-
- if let Some(ref ty) = default {
- self.ribs[TypeNS].push(default_ban_rib);
- self.visit_ty(ty);
- default_ban_rib = self.ribs[TypeNS].pop().unwrap();
- }
-
- // Allow all following defaults to refer to this type parameter.
- default_ban_rib.bindings.remove(&Ident::with_empty_ctxt(param.ident.name));
- }
- GenericParamKind::Const { ref ty } => {
- self.ribs[TypeNS].push(const_ty_param_ban_rib);
-
- for bound in ¶m.bounds {
- self.visit_param_bound(bound);
- }
-
- self.visit_ty(ty);
-
- const_ty_param_ban_rib = self.ribs[TypeNS].pop().unwrap();
- }
- }
- }
- for p in &generics.where_clause.predicates {
- self.visit_where_predicate(p);
- }
- }
-}
-
-#[derive(Copy, Clone)]
-enum GenericParameters<'a, 'b> {
- NoGenericParams,
- HasGenericParams(// Type parameters.
- &'b Generics,
-
- // The kind of the rib used for type parameters.
- RibKind<'a>),
-}
-
-/// The rib kind restricts certain accesses,
-/// e.g. to a `Res::Local` of an outer item.
-#[derive(Copy, Clone, Debug)]
-enum RibKind<'a> {
- /// No restriction needs to be applied.
- NormalRibKind,
-
- /// We passed through an impl or trait and are now in one of its
- /// methods or associated types. Allow references to ty params that impl or trait
- /// binds. Disallow any other upvars (including other ty params that are
- /// upvars).
- AssocItemRibKind,
-
- /// We passed through a function definition. Disallow upvars.
- /// Permit only those const parameters that are specified in the function's generics.
- FnItemRibKind,
-
- /// We passed through an item scope. Disallow upvars.
- ItemRibKind,
-
- /// We're in a constant item. Can't refer to dynamic stuff.
- ConstantItemRibKind,
-
- /// We passed through a module.
- ModuleRibKind(Module<'a>),
-
- /// We passed through a `macro_rules!` statement
- MacroDefinition(DefId),
-
- /// All bindings in this rib are type parameters that can't be used
- /// from the default of a type parameter because they're not declared
- /// before said type parameter. Also see the `visit_generics` override.
- ForwardTyParamBanRibKind,
-
- /// We forbid the use of type parameters as the types of const parameters.
- TyParamAsConstParamTy,
-}
-
-/// A single local scope.
-///
-/// A rib represents a scope names can live in. Note that these appear in many places, not just
-/// around braces. At any place where the list of accessible names (of the given namespace)
-/// changes or a new restrictions on the name accessibility are introduced, a new rib is put onto a
-/// stack. This may be, for example, a `let` statement (because it introduces variables), a macro,
-/// etc.
-///
-/// Different [rib kinds](enum.RibKind) are transparent for different names.
-///
-/// The resolution keeps a separate stack of ribs as it traverses the AST for each namespace. When
-/// resolving, the name is looked up from inside out.
-#[derive(Debug)]
-struct Rib<'a, R = Res> {
- bindings: FxHashMap<Ident, R>,
- kind: RibKind<'a>,
-}
-
-impl<'a, R> Rib<'a, R> {
- fn new(kind: RibKind<'a>) -> Rib<'a, R> {
- Rib {
- bindings: Default::default(),
- kind,
- }
- }
-}
-
/// An intermediate resolution result.
///
/// This refers to the thing referred by a name. The difference between `Res` and `Item` is that
/// items are visible in their whole block, while `Res`es only from the place they are defined
/// forward.
+#[derive(Debug)]
enum LexicalScopeBinding<'a> {
Item(&'a NameBinding<'a>),
Res(Res),
builtin_attrs: RefCell<Vec<(Ident, ParentScope<'a>)>>,
// Macro invocations that can expand into items in this module.
- unresolved_invocations: RefCell<FxHashSet<Mark>>,
+ unresolved_invocations: RefCell<FxHashSet<ExpnId>>,
no_implicit_prelude: bool,
/// Span of the module itself. Used for error reporting.
span: Span,
- expansion: Mark,
+ expansion: ExpnId,
}
type Module<'a> = &'a ModuleData<'a>;
fn new(parent: Option<Module<'a>>,
kind: ModuleKind,
normal_ancestor_id: DefId,
- expansion: Mark,
+ expansion: ExpnId,
span: Span) -> Self {
ModuleData {
parent,
}
}
- fn def_kind(&self) -> Option<DefKind> {
- match self.kind {
- ModuleKind::Def(kind, ..) => Some(kind),
- _ => None,
- }
- }
-
fn def_id(&self) -> Option<DefId> {
match self.kind {
ModuleKind::Def(_, def_id, _) => Some(def_id),
pub struct NameBinding<'a> {
kind: NameBindingKind<'a>,
ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
- expansion: Mark,
+ expansion: ExpnId,
span: Span,
vis: ty::Visibility,
}
}
fn macro_kind(&self) -> Option<MacroKind> {
- match self.res() {
- Res::Def(DefKind::Macro(kind), _) => Some(kind),
- Res::NonMacroAttr(..) => Some(MacroKind::Attr),
- _ => None,
- }
- }
-
- fn descr(&self) -> &'static str {
- if self.is_extern_crate() { "extern crate" } else { self.res().descr() }
- }
-
- fn article(&self) -> &'static str {
- if self.is_extern_crate() { "an" } else { self.res().article() }
+ self.res().macro_kind()
}
// Suppose that we resolved macro invocation with `invoc_parent_expansion` to binding `binding`
// in some later round and screw up our previously found resolution.
// See more detailed explanation in
// https://github.com/rust-lang/rust/pull/53778#issuecomment-419224049
- fn may_appear_after(&self, invoc_parent_expansion: Mark, binding: &NameBinding<'_>) -> bool {
+ fn may_appear_after(&self, invoc_parent_expansion: ExpnId, binding: &NameBinding<'_>) -> bool {
// self > max(invoc, binding) => !(self <= invoc || self <= binding)
// Expansions are partially ordered, so "may appear after" is an inversion of
// "certainly appears before or simultaneously" and includes unordered cases.
/// All non-determined imports.
indeterminate_imports: Vec<&'a ImportDirective<'a>>,
- /// The module that represents the current item scope.
- current_module: Module<'a>,
-
- /// The current set of local scopes for types and values.
- /// FIXME #4948: Reuse ribs to avoid allocation.
- ribs: PerNS<Vec<Rib<'a>>>,
-
- /// The current set of local scopes, for labels.
- label_ribs: Vec<Rib<'a, NodeId>>,
-
- /// The trait that the current context can refer to.
- current_trait_ref: Option<(Module<'a>, TraitRef)>,
-
- /// The current self type if inside an impl (used for better errors).
- current_self_type: Option<Ty>,
-
- /// The current self item if inside an ADT (used for better errors).
- current_self_item: Option<NodeId>,
-
/// FIXME: Refactor things so that these fields are passed through arguments and not resolver.
/// We are resolving a last import segment during import validation.
last_import_segment: bool,
pub maybe_unused_trait_imports: NodeSet,
pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
- /// A list of labels as of yet unused. Labels will be removed from this map when
- /// they are used (in a `break` or `continue` statement)
- pub unused_labels: FxHashMap<NodeId, Span>,
-
/// Privacy errors are delayed until the end in order to deduplicate them.
privacy_errors: Vec<PrivacyError<'a>>,
/// Ambiguity errors are delayed for deduplication.
crate_loader: &'a mut CrateLoader<'a>,
macro_names: FxHashSet<Ident>,
- builtin_macros: FxHashMap<Name, &'a NameBinding<'a>>,
+ builtin_macros: FxHashMap<Name, SyntaxExtension>,
macro_use_prelude: FxHashMap<Name, &'a NameBinding<'a>>,
pub all_macros: FxHashMap<Name, Res>,
macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
+ dummy_ext_bang: Lrc<SyntaxExtension>,
+ dummy_ext_derive: Lrc<SyntaxExtension>,
non_macro_attrs: [Lrc<SyntaxExtension>; 2],
- macro_defs: FxHashMap<Mark, DefId>,
+ macro_defs: FxHashMap<ExpnId, DefId>,
local_macro_def_scopes: FxHashMap<NodeId, Module<'a>>,
-
- /// List of crate local macros that we need to warn about as being unused.
- /// Right now this only includes macro_rules! macros, and macros 2.0.
- unused_macros: FxHashSet<DefId>,
-
- /// Maps the `Mark` of an expansion to its containing module or block.
- invocations: FxHashMap<Mark, &'a InvocationData<'a>>,
+ unused_macros: NodeMap<Span>,
+ proc_macro_stubs: NodeSet,
+ /// Some built-in derives mark items they are applied to so they are treated specially later.
+ /// Derive macros cannot modify the item themselves and have to store the markers in the global
+ /// context, so they attach the markers to derive container IDs using this resolver table.
+ /// FIXME: Find a way for `PartialEq` and `Eq` to emulate `#[structural_match]`
+ /// by marking the produced impls rather than the original items.
+ special_derives: FxHashMap<ExpnId, SpecialDerives>,
+
+ /// Maps the `ExpnId` of an expansion to its containing module or block.
+ invocations: FxHashMap<ExpnId, &'a InvocationData<'a>>,
/// Avoid duplicated errors for "name already defined".
name_already_seen: FxHashMap<Name, Span>,
/// it's not used during normal resolution, only for better error reporting.
struct_constructors: DefIdMap<(Res, ty::Visibility)>,
- /// Only used for better errors on `fn(): fn()`.
- current_type_ascription: Vec<Span>,
-
- injected_crate: Option<Module<'a>>,
+ /// Features enabled for this crate.
+ active_features: FxHashSet<Symbol>,
}
/// Nothing really interesting here; it just provides memory for the rest of the crate.
/// This interface is used through the AST→HIR step, to embed full paths into the HIR. After that
/// the resolver is no longer needed as all the relevant information is inline.
impl<'a> hir::lowering::Resolver for Resolver<'a> {
- fn resolve_ast_path(
- &mut self,
- path: &ast::Path,
- is_value: bool,
- ) -> Res {
- self.resolve_ast_path_cb(path, is_value,
- |resolver, span, error| resolve_error(resolver, span, error))
- }
-
fn resolve_str_path(
&mut self,
span: Span,
crate_root: Option<Symbol>,
components: &[Symbol],
- is_value: bool
+ ns: Namespace,
) -> (ast::Path, Res) {
let root = if crate_root.is_some() {
kw::PathRoot
segments,
};
- let res = self.resolve_ast_path(&path, is_value);
+ let parent_scope = &self.dummy_parent_scope();
+ let res = match self.resolve_ast_path(&path, ns, parent_scope) {
+ Ok(res) => res,
+ Err((span, error)) => {
+ self.report_error(span, error);
+ Res::Err
+ }
+ };
(path, res)
}
fn definitions(&mut self) -> &mut Definitions {
&mut self.definitions
- }
-}
-
-impl<'a> Resolver<'a> {
- /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
- /// isn't something that can be returned because it can't be made to live that long,
- /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
- /// just that an error occurred.
- pub fn resolve_str_path_error(&mut self, span: Span, path_str: &str, is_value: bool)
- -> Result<(ast::Path, Res), ()> {
- let mut errored = false;
-
- let path = if path_str.starts_with("::") {
- ast::Path {
- span,
- segments: iter::once(Ident::with_empty_ctxt(kw::PathRoot))
- .chain({
- path_str.split("::").skip(1).map(Ident::from_str)
- })
- .map(|i| self.new_ast_path_segment(i))
- .collect(),
- }
- } else {
- ast::Path {
- span,
- segments: path_str
- .split("::")
- .map(Ident::from_str)
- .map(|i| self.new_ast_path_segment(i))
- .collect(),
- }
- };
- let res = self.resolve_ast_path_cb(&path, is_value, |_, _, _| errored = true);
- if errored || res == def::Res::Err {
- Err(())
- } else {
- Ok((path, res))
- }
- }
-
- /// Like `resolve_ast_path`, but takes a callback in case there was an error.
- // FIXME(eddyb) use `Result` or something instead of callbacks.
- fn resolve_ast_path_cb<F>(
- &mut self,
- path: &ast::Path,
- is_value: bool,
- error_callback: F,
- ) -> Res
- where F: for<'c, 'b> FnOnce(&'c mut Resolver<'_>, Span, ResolutionError<'b>)
- {
- let namespace = if is_value { ValueNS } else { TypeNS };
- let span = path.span;
- let path = Segment::from_path(&path);
- // FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
- match self.resolve_path_without_parent_scope(&path, Some(namespace), true,
- span, CrateLint::No) {
- PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
- module.res().unwrap(),
- PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
- path_res.base_res(),
- PathResult::NonModule(..) => {
- error_callback(self, span, ResolutionError::FailedToResolve {
- label: String::from("type-relative paths are not supported in this context"),
- suggestion: None,
- });
- Res::Err
- }
- PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
- PathResult::Failed { span, label, suggestion, .. } => {
- error_callback(self, span, ResolutionError::FailedToResolve {
- label,
- suggestion,
- });
- Res::Err
- }
- }
- }
-
- fn new_ast_path_segment(&self, ident: Ident) -> ast::PathSegment {
- let mut seg = ast::PathSegment::from_ident(ident);
- seg.id = self.session.next_node_id();
- seg
+ }
+
+ fn has_derives(&self, node_id: NodeId, derives: SpecialDerives) -> bool {
+ let def_id = self.definitions.local_def_id(node_id);
+ let expn_id = self.definitions.expansion_that_defined(def_id.index);
+ self.has_derives(expn_id, derives)
}
}
);
let graph_root = arenas.alloc_module(ModuleData {
no_implicit_prelude: attr::contains_name(&krate.attrs, sym::no_implicit_prelude),
- ..ModuleData::new(None, root_module_kind, root_def_id, Mark::root(), krate.span)
+ ..ModuleData::new(None, root_module_kind, root_def_id, ExpnId::root(), krate.span)
});
let mut module_map = FxHashMap::default();
module_map.insert(DefId::local(CRATE_DEF_INDEX), graph_root);
let mut definitions = Definitions::default();
- DefCollector::new(&mut definitions, Mark::root())
- .collect_root(crate_name, session.local_crate_disambiguator());
+ definitions.create_root_def(crate_name, session.local_crate_disambiguator());
let mut extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'_>> =
session.opts.externs.iter().map(|kv| (Ident::from_str(kv.0), Default::default()))
}
let mut invocations = FxHashMap::default();
- invocations.insert(Mark::root(),
+ invocations.insert(ExpnId::root(),
arenas.alloc_invocation_data(InvocationData::root(graph_root)));
let mut macro_defs = FxHashMap::default();
- macro_defs.insert(Mark::root(), root_def_id);
+ macro_defs.insert(ExpnId::root(), root_def_id);
- let non_macro_attr = |mark_used| Lrc::new(SyntaxExtension::default(
- SyntaxExtensionKind::NonMacroAttr { mark_used }, session.edition()
- ));
+ let features = session.features_untracked();
+ let non_macro_attr =
+ |mark_used| Lrc::new(SyntaxExtension::non_macro_attr(mark_used, session.edition()));
Resolver {
session,
determined_imports: Vec::new(),
indeterminate_imports: Vec::new(),
- current_module: graph_root,
- ribs: PerNS {
- value_ns: vec![Rib::new(ModuleRibKind(graph_root))],
- type_ns: vec![Rib::new(ModuleRibKind(graph_root))],
- macro_ns: vec![Rib::new(ModuleRibKind(graph_root))],
- },
- label_ribs: Vec::new(),
-
- current_trait_ref: None,
- current_self_type: None,
- current_self_item: None,
last_import_segment: false,
blacklisted_binding: None,
maybe_unused_trait_imports: Default::default(),
maybe_unused_extern_crates: Vec::new(),
- unused_labels: FxHashMap::default(),
-
privacy_errors: Vec::new(),
ambiguity_errors: Vec::new(),
use_injections: Vec::new(),
dummy_binding: arenas.alloc_name_binding(NameBinding {
kind: NameBindingKind::Res(Res::Err, false),
ambiguity: None,
- expansion: Mark::root(),
+ expansion: ExpnId::root(),
span: DUMMY_SP,
vis: ty::Visibility::Public,
}),
crate_loader,
macro_names: FxHashSet::default(),
- builtin_macros: FxHashMap::default(),
+ builtin_macros: Default::default(),
macro_use_prelude: FxHashMap::default(),
all_macros: FxHashMap::default(),
macro_map: FxHashMap::default(),
+ dummy_ext_bang: Lrc::new(SyntaxExtension::dummy_bang(session.edition())),
+ dummy_ext_derive: Lrc::new(SyntaxExtension::dummy_derive(session.edition())),
non_macro_attrs: [non_macro_attr(false), non_macro_attr(true)],
invocations,
macro_defs,
name_already_seen: FxHashMap::default(),
potentially_unused_imports: Vec::new(),
struct_constructors: Default::default(),
- unused_macros: FxHashSet::default(),
- current_type_ascription: Vec::new(),
- injected_crate: None,
+ unused_macros: Default::default(),
+ proc_macro_stubs: Default::default(),
+ special_derives: Default::default(),
+ active_features:
+ features.declared_lib_features.iter().map(|(feat, ..)| *feat)
+ .chain(features.declared_lang_features.iter().map(|(feat, ..)| *feat))
+ .collect(),
}
}
self.non_macro_attrs[mark_used as usize].clone()
}
+ fn dummy_ext(&self, macro_kind: MacroKind) -> Lrc<SyntaxExtension> {
+ match macro_kind {
+ MacroKind::Bang => self.dummy_ext_bang.clone(),
+ MacroKind::Derive => self.dummy_ext_derive.clone(),
+ MacroKind::Attr => self.non_macro_attr(true),
+ }
+ }
+
/// Runs the function on each namespace.
fn per_ns<F: FnMut(&mut Self, Namespace)>(&mut self, mut f: F) {
f(self, TypeNS);
f(self, MacroNS);
}
+ fn is_builtin_macro(&mut self, def_id: Option<DefId>) -> bool {
+ def_id.and_then(|def_id| self.get_macro_by_def_id(def_id))
+ .map_or(false, |ext| ext.is_builtin)
+ }
+
fn macro_def(&self, mut ctxt: SyntaxContext) -> DefId {
loop {
- match self.macro_defs.get(&ctxt.outer()) {
+ match self.macro_defs.get(&ctxt.outer_expn()) {
Some(&def_id) => return def_id,
None => ctxt.remove_mark(),
};
}
}
+ fn has_derives(&self, expn_id: ExpnId, markers: SpecialDerives) -> bool {
+ self.special_derives.get(&expn_id).map_or(false, |m| m.contains(markers))
+ }
+
/// Entry point to crate resolution.
pub fn resolve_crate(&mut self, krate: &Crate) {
- ImportResolver { resolver: self }.finalize_imports();
- self.current_module = self.graph_root;
- self.finalize_current_module_macro_resolutions();
+ ImportResolver { r: self }.finalize_imports();
- visit::walk_crate(self, krate);
+ self.late_resolve_crate(krate);
- check_unused::check_crate(self, krate);
+ self.check_unused(krate);
self.report_errors(krate);
self.crate_loader.postprocess(krate);
}
parent: Module<'a>,
kind: ModuleKind,
normal_ancestor_id: DefId,
- expansion: Mark,
+ expn_id: ExpnId,
span: Span,
) -> Module<'a> {
- let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expansion, span);
+ let module = ModuleData::new(Some(parent), kind, normal_ancestor_id, expn_id, span);
self.arenas.alloc_module(module)
}
}
}
+ /// A generic scope visitor.
+ /// Visits scopes in order to resolve some identifier in them or perform other actions.
+ /// If the callback returns `Some` result, we stop visiting scopes and return it.
+ fn visit_scopes<T>(
+ &mut self,
+ scope_set: ScopeSet,
+ parent_scope: &ParentScope<'a>,
+ ident: Ident,
+ mut visitor: impl FnMut(&mut Self, Scope<'a>, /*use_prelude*/ bool, Ident) -> Option<T>,
+ ) -> Option<T> {
+ // General principles:
+ // 1. Not controlled (user-defined) names should have higher priority than controlled names
+ // built into the language or standard library. This way we can add new names into the
+ // language or standard library without breaking user code.
+ // 2. "Closed set" below means new names cannot appear after the current resolution attempt.
+ // Places to search (in order of decreasing priority):
+ // (Type NS)
+ // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet
+ // (open set, not controlled).
+ // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
+ // (open, not controlled).
+ // 3. Extern prelude (open, the open part is from macro expansions, not controlled).
+ // 4. Tool modules (closed, controlled right now, but not in the future).
+ // 5. Standard library prelude (de-facto closed, controlled).
+ // 6. Language prelude (closed, controlled).
+ // (Value NS)
+ // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet
+ // (open set, not controlled).
+ // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
+ // (open, not controlled).
+ // 3. Standard library prelude (de-facto closed, controlled).
+ // (Macro NS)
+ // 1-3. Derive helpers (open, not controlled). All ambiguities with other names
+ // are currently reported as errors. They should be higher in priority than preludes
+ // and probably even names in modules according to the "general principles" above. They
+ // also should be subject to restricted shadowing because are effectively produced by
+ // derives (you need to resolve the derive first to add helpers into scope), but they
+ // should be available before the derive is expanded for compatibility.
+ // It's mess in general, so we are being conservative for now.
+ // 1-3. `macro_rules` (open, not controlled), loop through legacy scopes. Have higher
+ // priority than prelude macros, but create ambiguities with macros in modules.
+ // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents
+ // (open, not controlled). Have higher priority than prelude macros, but create
+ // ambiguities with `macro_rules`.
+ // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled).
+ // 4a. User-defined prelude from macro-use
+ // (open, the open part is from macro expansions, not controlled).
+ // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled).
+ // 4c. Standard library prelude (de-facto closed, controlled).
+ // 6. Language prelude: builtin attributes (closed, controlled).
+ // 4-6. Legacy plugin helpers (open, not controlled). Similar to derive helpers,
+ // but introduced by legacy plugins using `register_attribute`. Priority is somewhere
+ // in prelude, not sure where exactly (creates ambiguities with any other prelude names).
+
+ let rust_2015 = ident.span.rust_2015();
+ let (ns, is_absolute_path) = match scope_set {
+ ScopeSet::All(ns, _) => (ns, false),
+ ScopeSet::AbsolutePath(ns) => (ns, true),
+ ScopeSet::Macro(_) => (MacroNS, false),
+ };
+ let mut scope = match ns {
+ _ if is_absolute_path => Scope::CrateRoot,
+ TypeNS | ValueNS => Scope::Module(parent_scope.module),
+ MacroNS => Scope::DeriveHelpers,
+ };
+ let mut ident = ident.modern();
+ let mut use_prelude = !parent_scope.module.no_implicit_prelude;
+
+ loop {
+ let visit = match scope {
+ Scope::DeriveHelpers => true,
+ Scope::MacroRules(..) => true,
+ Scope::CrateRoot => true,
+ Scope::Module(..) => true,
+ Scope::MacroUsePrelude => use_prelude || rust_2015,
+ Scope::BuiltinAttrs => true,
+ Scope::LegacyPluginHelpers => use_prelude || rust_2015,
+ Scope::ExternPrelude => use_prelude || is_absolute_path,
+ Scope::ToolPrelude => use_prelude,
+ Scope::StdLibPrelude => use_prelude || ns == MacroNS,
+ Scope::BuiltinTypes => true,
+ };
+
+ if visit {
+ if let break_result @ Some(..) = visitor(self, scope, use_prelude, ident) {
+ return break_result;
+ }
+ }
+
+ scope = match scope {
+ Scope::DeriveHelpers =>
+ Scope::MacroRules(parent_scope.legacy),
+ Scope::MacroRules(legacy_scope) => match legacy_scope {
+ LegacyScope::Binding(binding) => Scope::MacroRules(
+ binding.parent_legacy_scope
+ ),
+ LegacyScope::Invocation(invoc) => Scope::MacroRules(
+ invoc.output_legacy_scope.get().unwrap_or(invoc.parent_legacy_scope)
+ ),
+ LegacyScope::Empty => Scope::Module(parent_scope.module),
+ }
+ Scope::CrateRoot => match ns {
+ TypeNS => {
+ ident.span.adjust(ExpnId::root());
+ Scope::ExternPrelude
+ }
+ ValueNS | MacroNS => break,
+ }
+ Scope::Module(module) => {
+ use_prelude = !module.no_implicit_prelude;
+ match self.hygienic_lexical_parent(module, &mut ident.span) {
+ Some(parent_module) => Scope::Module(parent_module),
+ None => {
+ ident.span.adjust(ExpnId::root());
+ match ns {
+ TypeNS => Scope::ExternPrelude,
+ ValueNS => Scope::StdLibPrelude,
+ MacroNS => Scope::MacroUsePrelude,
+ }
+ }
+ }
+ }
+ Scope::MacroUsePrelude => Scope::StdLibPrelude,
+ Scope::BuiltinAttrs => Scope::LegacyPluginHelpers,
+ Scope::LegacyPluginHelpers => break, // nowhere else to search
+ Scope::ExternPrelude if is_absolute_path => break,
+ Scope::ExternPrelude => Scope::ToolPrelude,
+ Scope::ToolPrelude => Scope::StdLibPrelude,
+ Scope::StdLibPrelude => match ns {
+ TypeNS => Scope::BuiltinTypes,
+ ValueNS => break, // nowhere else to search
+ MacroNS => Scope::BuiltinAttrs,
+ }
+ Scope::BuiltinTypes => break, // nowhere else to search
+ };
+ }
+
+ None
+ }
+
/// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope.
/// More specifically, we proceed up the hierarchy of scopes and return the binding for
/// `ident` in the first scope that defines it (or None if no scopes define it).
fn resolve_ident_in_lexical_scope(&mut self,
mut ident: Ident,
ns: Namespace,
+ parent_scope: &ParentScope<'a>,
record_used_id: Option<NodeId>,
- path_span: Span)
+ path_span: Span,
+ ribs: &[Rib<'a>])
-> Option<LexicalScopeBinding<'a>> {
assert!(ns == TypeNS || ns == ValueNS);
if ident.name == kw::Invalid {
return Some(LexicalScopeBinding::Res(Res::Err));
}
- ident.span = if ident.name == kw::SelfUpper {
+ let (general_span, modern_span) = if ident.name == kw::SelfUpper {
// FIXME(jseyfried) improve `Self` hygiene
- ident.span.with_ctxt(SyntaxContext::empty())
+ let empty_span = ident.span.with_ctxt(SyntaxContext::empty());
+ (empty_span, empty_span)
} else if ns == TypeNS {
- ident.span.modern()
+ let modern_span = ident.span.modern();
+ (modern_span, modern_span)
} else {
- ident.span.modern_and_legacy()
+ (ident.span.modern_and_legacy(), ident.span.modern())
};
+ ident.span = general_span;
+ let modern_ident = Ident { span: modern_span, ..ident };
// Walk backwards up the ribs in scope.
let record_used = record_used_id.is_some();
let mut module = self.graph_root;
- for i in (0 .. self.ribs[ns].len()).rev() {
- debug!("walk rib\n{:?}", self.ribs[ns][i].bindings);
- if let Some(res) = self.ribs[ns][i].bindings.get(&ident).cloned() {
+ for i in (0 .. ribs.len()).rev() {
+ debug!("walk rib\n{:?}", ribs[i].bindings);
+ // Use the rib kind to determine whether we are resolving parameters
+ // (modern hygiene) or local variables (legacy hygiene).
+ let rib_ident = if let AssocItemRibKind | ItemRibKind = ribs[i].kind {
+ modern_ident
+ } else {
+ ident
+ };
+ if let Some(res) = ribs[i].bindings.get(&rib_ident).cloned() {
// The ident resolves to a type parameter or local variable.
return Some(LexicalScopeBinding::Res(
- self.validate_res_from_ribs(ns, i, res, record_used, path_span),
+ self.validate_res_from_ribs(i, res, record_used, path_span, ribs),
));
}
- module = match self.ribs[ns][i].kind {
+ module = match ribs[i].kind {
ModuleRibKind(module) => module,
MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
// If an invocation of this macro created `ident`, give up on `ident`
_ => continue,
};
+
let item = self.resolve_ident_in_module_unadjusted(
ModuleOrUniformRoot::Module(module),
ident,
ns,
+ parent_scope,
record_used,
path_span,
);
}
}
- ident.span = ident.span.modern();
+ ident = modern_ident;
let mut poisoned = None;
loop {
let opt_module = if let Some(node_id) = record_used_id {
self.hygienic_lexical_parent(module, &mut ident.span)
};
module = unwrap_or!(opt_module, break);
- let orig_current_module = self.current_module;
- self.current_module = module; // Lexical resolutions can never be a privacy error.
+ let adjusted_parent_scope = &ParentScope { module, ..parent_scope.clone() };
let result = self.resolve_ident_in_module_unadjusted(
ModuleOrUniformRoot::Module(module),
ident,
ns,
+ adjusted_parent_scope,
record_used,
path_span,
);
- self.current_module = orig_current_module;
match result {
Ok(binding) => {
}
if !module.no_implicit_prelude {
+ ident.span.adjust(ExpnId::root());
if ns == TypeNS {
if let Some(binding) = self.extern_prelude_get(ident, !record_used) {
return Some(LexicalScopeBinding::Item(binding));
}
}
- if ns == TypeNS && is_known_tool(ident.name) {
+ if ns == TypeNS && KNOWN_TOOLS.contains(&ident.name) {
let binding = (Res::ToolMod, ty::Visibility::Public,
- DUMMY_SP, Mark::root()).to_name_binding(self.arenas);
+ DUMMY_SP, ExpnId::root()).to_name_binding(self.arenas);
return Some(LexicalScopeBinding::Item(binding));
}
if let Some(prelude) = self.prelude {
ModuleOrUniformRoot::Module(prelude),
ident,
ns,
+ parent_scope,
false,
path_span,
) {
fn hygienic_lexical_parent(&mut self, module: Module<'a>, span: &mut Span)
-> Option<Module<'a>> {
- if !module.expansion.outer_is_descendant_of(span.ctxt()) {
+ if !module.expansion.outer_expn_is_descendant_of(span.ctxt()) {
return Some(self.macro_def_scope(span.remove_mark()));
}
module.expansion.is_descendant_of(parent.expansion) {
// The macro is a proc macro derive
if module.expansion.looks_like_proc_macro_derive() {
- if parent.expansion.outer_is_descendant_of(span.ctxt()) {
+ if parent.expansion.outer_expn_is_descendant_of(span.ctxt()) {
*poisoned = Some(node_id);
return module.parent;
}
module: ModuleOrUniformRoot<'a>,
ident: Ident,
ns: Namespace,
- parent_scope: Option<&ParentScope<'a>>,
+ parent_scope: &ParentScope<'a>,
record_used: bool,
path_span: Span
) -> Result<&'a NameBinding<'a>, Determinacy> {
module: ModuleOrUniformRoot<'a>,
mut ident: Ident,
ns: Namespace,
- parent_scope: Option<&ParentScope<'a>>,
+ parent_scope: &ParentScope<'a>,
record_used: bool,
path_span: Span
) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> {
- let orig_current_module = self.current_module;
+ let tmp_parent_scope;
+ let mut adjusted_parent_scope = parent_scope;
match module {
- ModuleOrUniformRoot::Module(module) => {
- if let Some(def) = ident.span.modernize_and_adjust(module.expansion) {
- self.current_module = self.macro_def_scope(def);
+ ModuleOrUniformRoot::Module(m) => {
+ if let Some(def) = ident.span.modernize_and_adjust(m.expansion) {
+ tmp_parent_scope =
+ ParentScope { module: self.macro_def_scope(def), ..parent_scope.clone() };
+ adjusted_parent_scope = &tmp_parent_scope;
}
}
ModuleOrUniformRoot::ExternPrelude => {
- ident.span.modernize_and_adjust(Mark::root());
+ ident.span.modernize_and_adjust(ExpnId::root());
}
ModuleOrUniformRoot::CrateRootAndExternPrelude |
ModuleOrUniformRoot::CurrentScope => {
}
}
let result = self.resolve_ident_in_module_unadjusted_ext(
- module, ident, ns, parent_scope, false, record_used, path_span,
+ module, ident, ns, adjusted_parent_scope, false, record_used, path_span,
);
- self.current_module = orig_current_module;
result
}
result
} else {
ctxt = ctxt.modern();
- ctxt.adjust(Mark::root())
+ ctxt.adjust(ExpnId::root())
};
let module = match mark {
Some(def) => self.macro_def_scope(def),
module
}
- // AST resolution
- //
- // We maintain a list of value ribs and type ribs.
- //
- // Simultaneously, we keep track of the current position in the module
- // graph in the `current_module` pointer. When we go to resolve a name in
- // the value or type namespaces, we first look through all the ribs and
- // then query the module graph. When we resolve a name in the module
- // namespace, we can skip all the ribs (since nested modules are not
- // allowed within blocks in Rust) and jump straight to the current module
- // graph node.
- //
- // Named implementations are handled separately. When we find a method
- // call, we consult the module node to find all of the implementations in
- // scope. This information is lazily cached in the module node. We then
- // generate a fake "implementation scope" containing all the
- // implementations thus found, for compatibility with old resolve pass.
-
- pub fn with_scope<F, T>(&mut self, id: NodeId, f: F) -> T
- where F: FnOnce(&mut Resolver<'_>) -> T
- {
- let id = self.definitions.local_def_id(id);
- let module = self.module_map.get(&id).cloned(); // clones a reference
- if let Some(module) = module {
- // Move down in the graph.
- let orig_module = replace(&mut self.current_module, module);
- self.ribs[ValueNS].push(Rib::new(ModuleRibKind(module)));
- self.ribs[TypeNS].push(Rib::new(ModuleRibKind(module)));
-
- self.finalize_current_module_macro_resolutions();
- let ret = f(self);
-
- self.current_module = orig_module;
- self.ribs[ValueNS].pop();
- self.ribs[TypeNS].pop();
- ret
- } else {
- f(self)
- }
- }
-
- /// Searches the current set of local scopes for labels. Returns the first non-`None` label that
- /// is returned by the given predicate function
- ///
- /// Stops after meeting a closure.
- fn search_label<P, R>(&self, mut ident: Ident, pred: P) -> Option<R>
- where P: Fn(&Rib<'_, NodeId>, Ident) -> Option<R>
- {
- for rib in self.label_ribs.iter().rev() {
- match rib.kind {
- NormalRibKind => {}
- // If an invocation of this macro created `ident`, give up on `ident`
- // and switch to `ident`'s source from the macro definition.
- MacroDefinition(def) => {
- if def == self.macro_def(ident.span.ctxt()) {
- ident.span.remove_mark();
- }
- }
- _ => {
- // Do not resolve labels across function boundary
- return None;
- }
- }
- let r = pred(rib, ident);
- if r.is_some() {
- return r;
- }
- }
- None
- }
-
- fn resolve_adt(&mut self, item: &Item, generics: &Generics) {
- debug!("resolve_adt");
- self.with_current_self_item(item, |this| {
- this.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| {
- let item_def_id = this.definitions.local_def_id(item.id);
- this.with_self_rib(Res::SelfTy(None, Some(item_def_id)), |this| {
- visit::walk_item(this, item);
- });
- });
- });
+ fn resolve_path(
+ &mut self,
+ path: &[Segment],
+ opt_ns: Option<Namespace>, // `None` indicates a module path in import
+ parent_scope: &ParentScope<'a>,
+ record_used: bool,
+ path_span: Span,
+ crate_lint: CrateLint,
+ ) -> PathResult<'a> {
+ self.resolve_path_with_ribs(
+ path, opt_ns, parent_scope, record_used, path_span, crate_lint, None
+ )
}
- fn future_proof_import(&mut self, use_tree: &ast::UseTree) {
- let segments = &use_tree.prefix.segments;
- if !segments.is_empty() {
- let ident = segments[0].ident;
- if ident.is_path_segment_keyword() || ident.span.rust_2015() {
- return;
- }
+ fn resolve_path_with_ribs(
+ &mut self,
+ path: &[Segment],
+ opt_ns: Option<Namespace>, // `None` indicates a module path in import
+ parent_scope: &ParentScope<'a>,
+ record_used: bool,
+ path_span: Span,
+ crate_lint: CrateLint,
+ ribs: Option<&PerNS<Vec<Rib<'a>>>>,
+ ) -> PathResult<'a> {
+ let mut module = None;
+ let mut allow_super = true;
+ let mut second_binding = None;
- let nss = match use_tree.kind {
- ast::UseTreeKind::Simple(..) if segments.len() == 1 => &[TypeNS, ValueNS][..],
- _ => &[TypeNS],
- };
- let report_error = |this: &Self, ns| {
- let what = if ns == TypeNS { "type parameters" } else { "local variables" };
- this.session.span_err(ident.span, &format!("imports cannot refer to {}", what));
- };
+ debug!(
+ "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
+ path_span={:?}, crate_lint={:?})",
+ path,
+ opt_ns,
+ record_used,
+ path_span,
+ crate_lint,
+ );
- for &ns in nss {
- match self.resolve_ident_in_lexical_scope(ident, ns, None, use_tree.prefix.span) {
- Some(LexicalScopeBinding::Res(..)) => {
- report_error(self, ns);
- }
- Some(LexicalScopeBinding::Item(binding)) => {
- let orig_blacklisted_binding =
- mem::replace(&mut self.blacklisted_binding, Some(binding));
- if let Some(LexicalScopeBinding::Res(..)) =
- self.resolve_ident_in_lexical_scope(ident, ns, None,
- use_tree.prefix.span) {
- report_error(self, ns);
+ for (i, &Segment { ident, id }) in path.iter().enumerate() {
+ debug!("resolve_path ident {} {:?} {:?}", i, ident, id);
+ let record_segment_res = |this: &mut Self, res| {
+ if record_used {
+ if let Some(id) = id {
+ if !this.partial_res_map.contains_key(&id) {
+ assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id");
+ this.record_partial_res(id, PartialRes::new(res));
}
- self.blacklisted_binding = orig_blacklisted_binding;
}
- None => {}
}
- }
- } else if let ast::UseTreeKind::Nested(use_trees) = &use_tree.kind {
- for (use_tree, _) in use_trees {
- self.future_proof_import(use_tree);
- }
- }
- }
-
- fn resolve_item(&mut self, item: &Item) {
- let name = item.ident.name;
- debug!("(resolving item) resolving {} ({:?})", name, item.node);
-
- match item.node {
- ItemKind::Ty(_, ref generics) |
- ItemKind::Existential(_, ref generics) |
- ItemKind::Fn(_, _, ref generics, _) => {
- self.with_generic_param_rib(
- HasGenericParams(generics, ItemRibKind),
- |this| visit::walk_item(this, item)
- );
- }
-
- ItemKind::Enum(_, ref generics) |
- ItemKind::Struct(_, ref generics) |
- ItemKind::Union(_, ref generics) => {
- self.resolve_adt(item, generics);
- }
-
- ItemKind::Impl(.., ref generics, ref opt_trait_ref, ref self_type, ref impl_items) =>
- self.resolve_implementation(generics,
- opt_trait_ref,
- &self_type,
- item.id,
- impl_items),
-
- ItemKind::Trait(.., ref generics, ref bounds, ref trait_items) => {
- // Create a new rib for the trait-wide type parameters.
- self.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| {
- let local_def_id = this.definitions.local_def_id(item.id);
- this.with_self_rib(Res::SelfTy(Some(local_def_id), None), |this| {
- this.visit_generics(generics);
- walk_list!(this, visit_param_bound, bounds);
-
- for trait_item in trait_items {
- let generic_params = HasGenericParams(&trait_item.generics,
- AssocItemRibKind);
- this.with_generic_param_rib(generic_params, |this| {
- match trait_item.node {
- TraitItemKind::Const(ref ty, ref default) => {
- this.visit_ty(ty);
-
- // Only impose the restrictions of
- // ConstRibKind for an actual constant
- // expression in a provided default.
- if let Some(ref expr) = *default{
- this.with_constant_rib(|this| {
- this.visit_expr(expr);
- });
- }
- }
- TraitItemKind::Method(_, _) => {
- visit::walk_trait_item(this, trait_item)
- }
- TraitItemKind::Type(..) => {
- visit::walk_trait_item(this, trait_item)
- }
- TraitItemKind::Macro(_) => {
- panic!("unexpanded macro in resolve!")
- }
- };
- });
- }
- });
- });
- }
-
- ItemKind::TraitAlias(ref generics, ref bounds) => {
- // Create a new rib for the trait-wide type parameters.
- self.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| {
- let local_def_id = this.definitions.local_def_id(item.id);
- this.with_self_rib(Res::SelfTy(Some(local_def_id), None), |this| {
- this.visit_generics(generics);
- walk_list!(this, visit_param_bound, bounds);
- });
- });
- }
-
- ItemKind::Mod(_) | ItemKind::ForeignMod(_) => {
- self.with_scope(item.id, |this| {
- visit::walk_item(this, item);
- });
- }
-
- ItemKind::Static(ref ty, _, ref expr) |
- ItemKind::Const(ref ty, ref expr) => {
- debug!("resolve_item ItemKind::Const");
- self.with_item_rib(|this| {
- this.visit_ty(ty);
- this.with_constant_rib(|this| {
- this.visit_expr(expr);
- });
- });
- }
-
- ItemKind::Use(ref use_tree) => {
- self.future_proof_import(use_tree);
- }
-
- ItemKind::ExternCrate(..) |
- ItemKind::MacroDef(..) | ItemKind::GlobalAsm(..) => {
- // do nothing, these are just around to be encoded
- }
-
- ItemKind::Mac(_) => panic!("unexpanded macro in resolve!"),
- }
- }
+ };
- fn with_generic_param_rib<'b, F>(&'b mut self, generic_params: GenericParameters<'a, 'b>, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- debug!("with_generic_param_rib");
- match generic_params {
- HasGenericParams(generics, rib_kind) => {
- let mut function_type_rib = Rib::new(rib_kind);
- let mut function_value_rib = Rib::new(rib_kind);
- let mut seen_bindings = FxHashMap::default();
- for param in &generics.params {
- match param.kind {
- GenericParamKind::Lifetime { .. } => {}
- GenericParamKind::Type { .. } => {
- let ident = param.ident.modern();
- debug!("with_generic_param_rib: {}", param.id);
-
- if seen_bindings.contains_key(&ident) {
- let span = seen_bindings.get(&ident).unwrap();
- let err = ResolutionError::NameAlreadyUsedInParameterList(
- ident.name,
- span,
- );
- resolve_error(self, param.ident.span, err);
- }
- seen_bindings.entry(ident).or_insert(param.ident.span);
+ let is_last = i == path.len() - 1;
+ let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
+ let name = ident.name;
- // Plain insert (no renaming).
- let res = Res::Def(
- DefKind::TyParam,
- self.definitions.local_def_id(param.id),
- );
- function_type_rib.bindings.insert(ident, res);
- self.record_partial_res(param.id, PartialRes::new(res));
- }
- GenericParamKind::Const { .. } => {
- let ident = param.ident.modern();
- debug!("with_generic_param_rib: {}", param.id);
-
- if seen_bindings.contains_key(&ident) {
- let span = seen_bindings.get(&ident).unwrap();
- let err = ResolutionError::NameAlreadyUsedInParameterList(
- ident.name,
- span,
- );
- resolve_error(self, param.ident.span, err);
- }
- seen_bindings.entry(ident).or_insert(param.ident.span);
+ allow_super &= ns == TypeNS &&
+ (name == kw::SelfLower ||
+ name == kw::Super);
- let res = Res::Def(
- DefKind::ConstParam,
- self.definitions.local_def_id(param.id),
- );
- function_value_rib.bindings.insert(ident, res);
- self.record_partial_res(param.id, PartialRes::new(res));
+ if ns == TypeNS {
+ if allow_super && name == kw::Super {
+ let mut ctxt = ident.span.ctxt().modern();
+ let self_module = match i {
+ 0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)),
+ _ => match module {
+ Some(ModuleOrUniformRoot::Module(module)) => Some(module),
+ _ => None,
+ },
+ };
+ if let Some(self_module) = self_module {
+ if let Some(parent) = self_module.parent {
+ module = Some(ModuleOrUniformRoot::Module(
+ self.resolve_self(&mut ctxt, parent)));
+ continue;
}
}
+ let msg = "there are too many initial `super`s.".to_string();
+ return PathResult::Failed {
+ span: ident.span,
+ label: msg,
+ suggestion: None,
+ is_error_from_last_segment: false,
+ };
+ }
+ if i == 0 {
+ if name == kw::SelfLower {
+ let mut ctxt = ident.span.ctxt().modern();
+ module = Some(ModuleOrUniformRoot::Module(
+ self.resolve_self(&mut ctxt, parent_scope.module)));
+ continue;
+ }
+ if name == kw::PathRoot && ident.span.rust_2018() {
+ module = Some(ModuleOrUniformRoot::ExternPrelude);
+ continue;
+ }
+ if name == kw::PathRoot &&
+ ident.span.rust_2015() && self.session.rust_2018() {
+ // `::a::b` from 2015 macro on 2018 global edition
+ module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude);
+ continue;
+ }
+ if name == kw::PathRoot ||
+ name == kw::Crate ||
+ name == kw::DollarCrate {
+ // `::a::b`, `crate::a::b` or `$crate::a::b`
+ module = Some(ModuleOrUniformRoot::Module(
+ self.resolve_crate_root(ident)));
+ continue;
+ }
}
- self.ribs[ValueNS].push(function_value_rib);
- self.ribs[TypeNS].push(function_type_rib);
}
- NoGenericParams => {
- // Nothing to do.
+ // Report special messages for path segment keywords in wrong positions.
+ if ident.is_path_segment_keyword() && i != 0 {
+ let name_str = if name == kw::PathRoot {
+ "crate root".to_string()
+ } else {
+ format!("`{}`", name)
+ };
+ let label = if i == 1 && path[0].ident.name == kw::PathRoot {
+ format!("global paths cannot start with {}", name_str)
+ } else {
+ format!("{} in paths can only be used in start position", name_str)
+ };
+ return PathResult::Failed {
+ span: ident.span,
+ label,
+ suggestion: None,
+ is_error_from_last_segment: false,
+ };
}
- }
-
- f(self);
- if let HasGenericParams(..) = generic_params {
- self.ribs[TypeNS].pop();
- self.ribs[ValueNS].pop();
- }
- }
-
- fn with_label_rib<F>(&mut self, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- self.label_ribs.push(Rib::new(NormalRibKind));
- f(self);
- self.label_ribs.pop();
- }
-
- fn with_item_rib<F>(&mut self, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- self.ribs[ValueNS].push(Rib::new(ItemRibKind));
- self.ribs[TypeNS].push(Rib::new(ItemRibKind));
- f(self);
- self.ribs[TypeNS].pop();
- self.ribs[ValueNS].pop();
- }
-
- fn with_constant_rib<F>(&mut self, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- debug!("with_constant_rib");
- self.ribs[ValueNS].push(Rib::new(ConstantItemRibKind));
- self.label_ribs.push(Rib::new(ConstantItemRibKind));
- f(self);
- self.label_ribs.pop();
- self.ribs[ValueNS].pop();
- }
-
- fn with_current_self_type<T, F>(&mut self, self_type: &Ty, f: F) -> T
- where F: FnOnce(&mut Resolver<'_>) -> T
- {
- // Handle nested impls (inside fn bodies)
- let previous_value = replace(&mut self.current_self_type, Some(self_type.clone()));
- let result = f(self);
- self.current_self_type = previous_value;
- result
- }
-
- fn with_current_self_item<T, F>(&mut self, self_item: &Item, f: F) -> T
- where F: FnOnce(&mut Resolver<'_>) -> T
- {
- let previous_value = replace(&mut self.current_self_item, Some(self_item.id));
- let result = f(self);
- self.current_self_item = previous_value;
- result
- }
-
- /// This is called to resolve a trait reference from an `impl` (i.e., `impl Trait for Foo`).
- fn with_optional_trait_ref<T, F>(&mut self, opt_trait_ref: Option<&TraitRef>, f: F) -> T
- where F: FnOnce(&mut Resolver<'_>, Option<DefId>) -> T
- {
- let mut new_val = None;
- let mut new_id = None;
- if let Some(trait_ref) = opt_trait_ref {
- let path: Vec<_> = Segment::from_path(&trait_ref.path);
- let res = self.smart_resolve_path_fragment(
- trait_ref.ref_id,
- None,
- &path,
- trait_ref.path.span,
- PathSource::Trait(AliasPossibility::No),
- CrateLint::SimplePath(trait_ref.ref_id),
- ).base_res();
- if res != Res::Err {
- new_id = Some(res.def_id());
- let span = trait_ref.path.span;
- if let PathResult::Module(ModuleOrUniformRoot::Module(module)) =
- self.resolve_path_without_parent_scope(
- &path,
- Some(TypeNS),
- false,
- span,
- CrateLint::SimplePath(trait_ref.ref_id),
- )
- {
- new_val = Some((module, trait_ref.clone()));
- }
- }
- }
- let original_trait_ref = replace(&mut self.current_trait_ref, new_val);
- let result = f(self, new_id);
- self.current_trait_ref = original_trait_ref;
- result
- }
-
- fn with_self_rib<F>(&mut self, self_res: Res, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- let mut self_type_rib = Rib::new(NormalRibKind);
-
- // Plain insert (no renaming, since types are not currently hygienic)
- self_type_rib.bindings.insert(Ident::with_empty_ctxt(kw::SelfUpper), self_res);
- self.ribs[TypeNS].push(self_type_rib);
- f(self);
- self.ribs[TypeNS].pop();
- }
-
- fn with_self_struct_ctor_rib<F>(&mut self, impl_id: DefId, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- let self_res = Res::SelfCtor(impl_id);
- let mut self_type_rib = Rib::new(NormalRibKind);
- self_type_rib.bindings.insert(Ident::with_empty_ctxt(kw::SelfUpper), self_res);
- self.ribs[ValueNS].push(self_type_rib);
- f(self);
- self.ribs[ValueNS].pop();
- }
-
- fn resolve_implementation(&mut self,
- generics: &Generics,
- opt_trait_reference: &Option<TraitRef>,
- self_type: &Ty,
- item_id: NodeId,
- impl_items: &[ImplItem]) {
- debug!("resolve_implementation");
- // If applicable, create a rib for the type parameters.
- self.with_generic_param_rib(HasGenericParams(generics, ItemRibKind), |this| {
- // Dummy self type for better errors if `Self` is used in the trait path.
- this.with_self_rib(Res::SelfTy(None, None), |this| {
- // Resolve the trait reference, if necessary.
- this.with_optional_trait_ref(opt_trait_reference.as_ref(), |this, trait_id| {
- let item_def_id = this.definitions.local_def_id(item_id);
- this.with_self_rib(Res::SelfTy(trait_id, Some(item_def_id)), |this| {
- if let Some(trait_ref) = opt_trait_reference.as_ref() {
- // Resolve type arguments in the trait path.
- visit::walk_trait_ref(this, trait_ref);
- }
- // Resolve the self type.
- this.visit_ty(self_type);
- // Resolve the generic parameters.
- this.visit_generics(generics);
- // Resolve the items within the impl.
- this.with_current_self_type(self_type, |this| {
- this.with_self_struct_ctor_rib(item_def_id, |this| {
- debug!("resolve_implementation with_self_struct_ctor_rib");
- for impl_item in impl_items {
- this.resolve_visibility(&impl_item.vis);
-
- // We also need a new scope for the impl item type parameters.
- let generic_params = HasGenericParams(&impl_item.generics,
- AssocItemRibKind);
- this.with_generic_param_rib(generic_params, |this| {
- use self::ResolutionError::*;
- match impl_item.node {
- ImplItemKind::Const(..) => {
- debug!(
- "resolve_implementation ImplItemKind::Const",
- );
- // If this is a trait impl, ensure the const
- // exists in trait
- this.check_trait_item(
- impl_item.ident,
- ValueNS,
- impl_item.span,
- |n, s| ConstNotMemberOfTrait(n, s),
- );
-
- this.with_constant_rib(|this| {
- visit::walk_impl_item(this, impl_item)
- });
- }
- ImplItemKind::Method(..) => {
- // If this is a trait impl, ensure the method
- // exists in trait
- this.check_trait_item(impl_item.ident,
- ValueNS,
- impl_item.span,
- |n, s| MethodNotMemberOfTrait(n, s));
-
- visit::walk_impl_item(this, impl_item);
- }
- ImplItemKind::Type(ref ty) => {
- // If this is a trait impl, ensure the type
- // exists in trait
- this.check_trait_item(impl_item.ident,
- TypeNS,
- impl_item.span,
- |n, s| TypeNotMemberOfTrait(n, s));
-
- this.visit_ty(ty);
- }
- ImplItemKind::Existential(ref bounds) => {
- // If this is a trait impl, ensure the type
- // exists in trait
- this.check_trait_item(impl_item.ident,
- TypeNS,
- impl_item.span,
- |n, s| TypeNotMemberOfTrait(n, s));
-
- for bound in bounds {
- this.visit_param_bound(bound);
- }
- }
- ImplItemKind::Macro(_) =>
- panic!("unexpanded macro in resolve!"),
- }
- });
- }
- });
- });
- });
- });
- });
- });
- }
-
- fn check_trait_item<F>(&mut self, ident: Ident, ns: Namespace, span: Span, err: F)
- where F: FnOnce(Name, &str) -> ResolutionError<'_>
- {
- // If there is a TraitRef in scope for an impl, then the method must be in the
- // trait.
- if let Some((module, _)) = self.current_trait_ref {
- if self.resolve_ident_in_module(
- ModuleOrUniformRoot::Module(module),
- ident,
- ns,
- None,
- false,
- span,
- ).is_err() {
- let path = &self.current_trait_ref.as_ref().unwrap().1.path;
- resolve_error(self, span, err(ident.name, &path_names_to_string(path)));
- }
- }
- }
-
- fn resolve_local(&mut self, local: &Local) {
- // Resolve the type.
- walk_list!(self, visit_ty, &local.ty);
-
- // Resolve the initializer.
- walk_list!(self, visit_expr, &local.init);
-
- // Resolve the pattern.
- self.resolve_pattern(&local.pat, PatternSource::Let, &mut FxHashMap::default());
- }
-
- // build a map from pattern identifiers to binding-info's.
- // this is done hygienically. This could arise for a macro
- // that expands into an or-pattern where one 'x' was from the
- // user and one 'x' came from the macro.
- fn binding_mode_map(&mut self, pat: &Pat) -> BindingMap {
- let mut binding_map = FxHashMap::default();
-
- pat.walk(&mut |pat| {
- if let PatKind::Ident(binding_mode, ident, ref sub_pat) = pat.node {
- if sub_pat.is_some() || match self.partial_res_map.get(&pat.id)
- .map(|res| res.base_res()) {
- Some(Res::Local(..)) => true,
- _ => false,
- } {
- let binding_info = BindingInfo { span: ident.span, binding_mode: binding_mode };
- binding_map.insert(ident, binding_info);
- }
- }
- true
- });
-
- binding_map
- }
-
- // Checks that all of the arms in an or-pattern have exactly the
- // same set of bindings, with the same binding modes for each.
- fn check_consistent_bindings(&mut self, pats: &[P<Pat>]) {
- if pats.is_empty() {
- return;
- }
-
- let mut missing_vars = FxHashMap::default();
- let mut inconsistent_vars = FxHashMap::default();
- for (i, p) in pats.iter().enumerate() {
- let map_i = self.binding_mode_map(&p);
-
- for (j, q) in pats.iter().enumerate() {
- if i == j {
- continue;
- }
-
- let map_j = self.binding_mode_map(&q);
- for (&key, &binding_i) in &map_i {
- if map_j.is_empty() { // Account for missing bindings when
- let binding_error = missing_vars // `map_j` has none.
- .entry(key.name)
- .or_insert(BindingError {
- name: key.name,
- origin: BTreeSet::new(),
- target: BTreeSet::new(),
- });
- binding_error.origin.insert(binding_i.span);
- binding_error.target.insert(q.span);
- }
- for (&key_j, &binding_j) in &map_j {
- match map_i.get(&key_j) {
- None => { // missing binding
- let binding_error = missing_vars
- .entry(key_j.name)
- .or_insert(BindingError {
- name: key_j.name,
- origin: BTreeSet::new(),
- target: BTreeSet::new(),
- });
- binding_error.origin.insert(binding_j.span);
- binding_error.target.insert(p.span);
- }
- Some(binding_i) => { // check consistent binding
- if binding_i.binding_mode != binding_j.binding_mode {
- inconsistent_vars
- .entry(key.name)
- .or_insert((binding_j.span, binding_i.span));
- }
- }
- }
- }
- }
- }
- }
- let mut missing_vars = missing_vars.iter().collect::<Vec<_>>();
- missing_vars.sort();
- for (_, v) in missing_vars {
- resolve_error(self,
- *v.origin.iter().next().unwrap(),
- ResolutionError::VariableNotBoundInPattern(v));
- }
- let mut inconsistent_vars = inconsistent_vars.iter().collect::<Vec<_>>();
- inconsistent_vars.sort();
- for (name, v) in inconsistent_vars {
- resolve_error(self, v.0, ResolutionError::VariableBoundWithDifferentMode(*name, v.1));
- }
- }
-
- fn resolve_arm(&mut self, arm: &Arm) {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
-
- self.resolve_pats(&arm.pats, PatternSource::Match);
-
- if let Some(ref expr) = arm.guard {
- self.visit_expr(expr)
- }
- self.visit_expr(&arm.body);
-
- self.ribs[ValueNS].pop();
- }
-
- /// Arising from `source`, resolve a sequence of patterns (top level or-patterns).
- fn resolve_pats(&mut self, pats: &[P<Pat>], source: PatternSource) {
- let mut bindings_list = FxHashMap::default();
- for pat in pats {
- self.resolve_pattern(pat, source, &mut bindings_list);
- }
- // This has to happen *after* we determine which pat_idents are variants
- self.check_consistent_bindings(pats);
- }
-
- fn resolve_block(&mut self, block: &Block) {
- debug!("(resolving block) entering block");
- // Move down in the graph, if there's an anonymous module rooted here.
- let orig_module = self.current_module;
- let anonymous_module = self.block_map.get(&block.id).cloned(); // clones a reference
-
- let mut num_macro_definition_ribs = 0;
- if let Some(anonymous_module) = anonymous_module {
- debug!("(resolving block) found anonymous module, moving down");
- self.ribs[ValueNS].push(Rib::new(ModuleRibKind(anonymous_module)));
- self.ribs[TypeNS].push(Rib::new(ModuleRibKind(anonymous_module)));
- self.current_module = anonymous_module;
- self.finalize_current_module_macro_resolutions();
- } else {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- }
-
- // Descend into the block.
- for stmt in &block.stmts {
- if let ast::StmtKind::Item(ref item) = stmt.node {
- if let ast::ItemKind::MacroDef(..) = item.node {
- num_macro_definition_ribs += 1;
- let res = self.definitions.local_def_id(item.id);
- self.ribs[ValueNS].push(Rib::new(MacroDefinition(res)));
- self.label_ribs.push(Rib::new(MacroDefinition(res)));
- }
- }
-
- self.visit_stmt(stmt);
- }
-
- // Move back up.
- self.current_module = orig_module;
- for _ in 0 .. num_macro_definition_ribs {
- self.ribs[ValueNS].pop();
- self.label_ribs.pop();
- }
- self.ribs[ValueNS].pop();
- if anonymous_module.is_some() {
- self.ribs[TypeNS].pop();
- }
- debug!("(resolving block) leaving block");
- }
-
- fn fresh_binding(&mut self,
- ident: Ident,
- pat_id: NodeId,
- outer_pat_id: NodeId,
- pat_src: PatternSource,
- bindings: &mut FxHashMap<Ident, NodeId>)
- -> Res {
- // Add the binding to the local ribs, if it
- // doesn't already exist in the bindings map. (We
- // must not add it if it's in the bindings map
- // because that breaks the assumptions later
- // passes make about or-patterns.)
- let ident = ident.modern_and_legacy();
- let mut res = Res::Local(pat_id);
- match bindings.get(&ident).cloned() {
- Some(id) if id == outer_pat_id => {
- // `Variant(a, a)`, error
- resolve_error(
- self,
- ident.span,
- ResolutionError::IdentifierBoundMoreThanOnceInSamePattern(
- &ident.as_str())
- );
- }
- Some(..) if pat_src == PatternSource::FnParam => {
- // `fn f(a: u8, a: u8)`, error
- resolve_error(
- self,
- ident.span,
- ResolutionError::IdentifierBoundMoreThanOnceInParameterList(
- &ident.as_str())
- );
- }
- Some(..) if pat_src == PatternSource::Match ||
- pat_src == PatternSource::Let => {
- // `Variant1(a) | Variant2(a)`, ok
- // Reuse definition from the first `a`.
- res = self.ribs[ValueNS].last_mut().unwrap().bindings[&ident];
- }
- Some(..) => {
- span_bug!(ident.span, "two bindings with the same name from \
- unexpected pattern source {:?}", pat_src);
- }
- None => {
- // A completely fresh binding, add to the lists if it's valid.
- if ident.name != kw::Invalid {
- bindings.insert(ident, outer_pat_id);
- self.ribs[ValueNS].last_mut().unwrap().bindings.insert(ident, res);
- }
- }
- }
-
- res
- }
-
- fn resolve_pattern(&mut self,
- pat: &Pat,
- pat_src: PatternSource,
- // Maps idents to the node ID for the
- // outermost pattern that binds them.
- bindings: &mut FxHashMap<Ident, NodeId>) {
- // Visit all direct subpatterns of this pattern.
- let outer_pat_id = pat.id;
- pat.walk(&mut |pat| {
- debug!("resolve_pattern pat={:?} node={:?}", pat, pat.node);
- match pat.node {
- PatKind::Ident(bmode, ident, ref opt_pat) => {
- // First try to resolve the identifier as some existing
- // entity, then fall back to a fresh binding.
- let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS,
- None, pat.span)
- .and_then(LexicalScopeBinding::item);
- let res = binding.map(NameBinding::res).and_then(|res| {
- let is_syntactic_ambiguity = opt_pat.is_none() &&
- bmode == BindingMode::ByValue(Mutability::Immutable);
- match res {
- Res::Def(DefKind::Ctor(_, CtorKind::Const), _) |
- Res::Def(DefKind::Const, _) if is_syntactic_ambiguity => {
- // Disambiguate in favor of a unit struct/variant
- // or constant pattern.
- self.record_use(ident, ValueNS, binding.unwrap(), false);
- Some(res)
- }
- Res::Def(DefKind::Ctor(..), _)
- | Res::Def(DefKind::Const, _)
- | Res::Def(DefKind::Static, _) => {
- // This is unambiguously a fresh binding, either syntactically
- // (e.g., `IDENT @ PAT` or `ref IDENT`) or because `IDENT` resolves
- // to something unusable as a pattern (e.g., constructor function),
- // but we still conservatively report an error, see
- // issues/33118#issuecomment-233962221 for one reason why.
- resolve_error(
- self,
- ident.span,
- ResolutionError::BindingShadowsSomethingUnacceptable(
- pat_src.descr(), ident.name, binding.unwrap())
- );
- None
- }
- Res::Def(DefKind::Fn, _) | Res::Err => {
- // These entities are explicitly allowed
- // to be shadowed by fresh bindings.
- None
- }
- res => {
- span_bug!(ident.span, "unexpected resolution for an \
- identifier in pattern: {:?}", res);
- }
- }
- }).unwrap_or_else(|| {
- self.fresh_binding(ident, pat.id, outer_pat_id, pat_src, bindings)
- });
-
- self.record_partial_res(pat.id, PartialRes::new(res));
- }
-
- PatKind::TupleStruct(ref path, ..) => {
- self.smart_resolve_path(pat.id, None, path, PathSource::TupleStruct);
- }
-
- PatKind::Path(ref qself, ref path) => {
- self.smart_resolve_path(pat.id, qself.as_ref(), path, PathSource::Pat);
- }
-
- PatKind::Struct(ref path, ..) => {
- self.smart_resolve_path(pat.id, None, path, PathSource::Struct);
- }
-
- _ => {}
- }
- true
- });
-
- visit::walk_pat(self, pat);
- }
-
- // High-level and context dependent path resolution routine.
- // Resolves the path and records the resolution into definition map.
- // If resolution fails tries several techniques to find likely
- // resolution candidates, suggest imports or other help, and report
- // errors in user friendly way.
- fn smart_resolve_path(&mut self,
- id: NodeId,
- qself: Option<&QSelf>,
- path: &Path,
- source: PathSource<'_>) {
- self.smart_resolve_path_fragment(
- id,
- qself,
- &Segment::from_path(path),
- path.span,
- source,
- CrateLint::SimplePath(id),
- );
- }
-
- fn smart_resolve_path_fragment(&mut self,
- id: NodeId,
- qself: Option<&QSelf>,
- path: &[Segment],
- span: Span,
- source: PathSource<'_>,
- crate_lint: CrateLint)
- -> PartialRes {
- let ns = source.namespace();
- let is_expected = &|res| source.is_expected(res);
-
- let report_errors = |this: &mut Self, res: Option<Res>| {
- let (err, candidates) = this.smart_resolve_report_errors(path, span, source, res);
- let def_id = this.current_module.normal_ancestor_id;
- let node_id = this.definitions.as_local_node_id(def_id).unwrap();
- let better = res.is_some();
- this.use_injections.push(UseError { err, candidates, node_id, better });
- PartialRes::new(Res::Err)
- };
-
- let partial_res = match self.resolve_qpath_anywhere(
- id,
- qself,
- path,
- ns,
- span,
- source.defer_to_typeck(),
- source.global_by_default(),
- crate_lint,
- ) {
- Some(partial_res) if partial_res.unresolved_segments() == 0 => {
- if is_expected(partial_res.base_res()) || partial_res.base_res() == Res::Err {
- partial_res
- } else {
- // Add a temporary hack to smooth the transition to new struct ctor
- // visibility rules. See #38932 for more details.
- let mut res = None;
- if let Res::Def(DefKind::Struct, def_id) = partial_res.base_res() {
- if let Some((ctor_res, ctor_vis))
- = self.struct_constructors.get(&def_id).cloned() {
- if is_expected(ctor_res) && self.is_accessible(ctor_vis) {
- let lint = lint::builtin::LEGACY_CONSTRUCTOR_VISIBILITY;
- self.session.buffer_lint(lint, id, span,
- "private struct constructors are not usable through \
- re-exports in outer modules",
- );
- res = Some(PartialRes::new(ctor_res));
- }
- }
- }
-
- res.unwrap_or_else(|| report_errors(self, Some(partial_res.base_res())))
- }
- }
- Some(partial_res) if source.defer_to_typeck() => {
- // Not fully resolved associated item `T::A::B` or `<T as Tr>::A::B`
- // or `<T>::A::B`. If `B` should be resolved in value namespace then
- // it needs to be added to the trait map.
- if ns == ValueNS {
- let item_name = path.last().unwrap().ident;
- let traits = self.get_traits_containing_item(item_name, ns);
- self.trait_map.insert(id, traits);
- }
-
- let mut std_path = vec![Segment::from_ident(Ident::with_empty_ctxt(sym::std))];
- std_path.extend(path);
- if self.primitive_type_table.primitive_types.contains_key(&path[0].ident.name) {
- let cl = CrateLint::No;
- let ns = Some(ns);
- if let PathResult::Module(_) | PathResult::NonModule(_) =
- self.resolve_path_without_parent_scope(&std_path, ns, false, span, cl)
- {
- // check if we wrote `str::from_utf8` instead of `std::str::from_utf8`
- let item_span = path.iter().last().map(|segment| segment.ident.span)
- .unwrap_or(span);
- debug!("accessed item from `std` submodule as a bare type {:?}", std_path);
- let mut hm = self.session.confused_type_with_std_module.borrow_mut();
- hm.insert(item_span, span);
- // In some places (E0223) we only have access to the full path
- hm.insert(span, span);
- }
- }
- partial_res
- }
- _ => report_errors(self, None)
- };
-
- if let PathSource::TraitItem(..) = source {} else {
- // Avoid recording definition of `A::B` in `<T as A>::B::C`.
- self.record_partial_res(id, partial_res);
- }
- partial_res
- }
-
- /// Only used in a specific case of type ascription suggestions
- #[doc(hidden)]
- fn get_colon_suggestion_span(&self, start: Span) -> Span {
- let cm = self.session.source_map();
- start.to(cm.next_point(start))
- }
-
- fn type_ascription_suggestion(
- &self,
- err: &mut DiagnosticBuilder<'_>,
- base_span: Span,
- ) {
- debug!("type_ascription_suggetion {:?}", base_span);
- let cm = self.session.source_map();
- let base_snippet = cm.span_to_snippet(base_span);
- debug!("self.current_type_ascription {:?}", self.current_type_ascription);
- if let Some(sp) = self.current_type_ascription.last() {
- let mut sp = *sp;
- loop {
- // Try to find the `:`; bail on first non-':' / non-whitespace.
- sp = cm.next_point(sp);
- if let Ok(snippet) = cm.span_to_snippet(sp.to(cm.next_point(sp))) {
- let line_sp = cm.lookup_char_pos(sp.hi()).line;
- let line_base_sp = cm.lookup_char_pos(base_span.lo()).line;
- if snippet == ":" {
- let mut show_label = true;
- if line_sp != line_base_sp {
- err.span_suggestion_short(
- sp,
- "did you mean to use `;` here instead?",
- ";".to_string(),
- Applicability::MaybeIncorrect,
- );
- } else {
- let colon_sp = self.get_colon_suggestion_span(sp);
- let after_colon_sp = self.get_colon_suggestion_span(
- colon_sp.shrink_to_hi(),
- );
- if !cm.span_to_snippet(after_colon_sp).map(|s| s == " ")
- .unwrap_or(false)
- {
- err.span_suggestion(
- colon_sp,
- "maybe you meant to write a path separator here",
- "::".to_string(),
- Applicability::MaybeIncorrect,
- );
- show_label = false;
- }
- if let Ok(base_snippet) = base_snippet {
- let mut sp = after_colon_sp;
- for _ in 0..100 {
- // Try to find an assignment
- sp = cm.next_point(sp);
- let snippet = cm.span_to_snippet(sp.to(cm.next_point(sp)));
- match snippet {
- Ok(ref x) if x.as_str() == "=" => {
- err.span_suggestion(
- base_span,
- "maybe you meant to write an assignment here",
- format!("let {}", base_snippet),
- Applicability::MaybeIncorrect,
- );
- show_label = false;
- break;
- }
- Ok(ref x) if x.as_str() == "\n" => break,
- Err(_) => break,
- Ok(_) => {}
- }
- }
- }
- }
- if show_label {
- err.span_label(base_span,
- "expecting a type here because of type ascription");
- }
- break;
- } else if !snippet.trim().is_empty() {
- debug!("tried to find type ascription `:` token, couldn't find it");
- break;
- }
- } else {
- break;
- }
- }
- }
- }
-
- fn self_type_is_available(&mut self, span: Span) -> bool {
- let binding = self.resolve_ident_in_lexical_scope(Ident::with_empty_ctxt(kw::SelfUpper),
- TypeNS, None, span);
- if let Some(LexicalScopeBinding::Res(res)) = binding { res != Res::Err } else { false }
- }
-
- fn self_value_is_available(&mut self, self_span: Span, path_span: Span) -> bool {
- let ident = Ident::new(kw::SelfLower, self_span);
- let binding = self.resolve_ident_in_lexical_scope(ident, ValueNS, None, path_span);
- if let Some(LexicalScopeBinding::Res(res)) = binding { res != Res::Err } else { false }
- }
-
- // Resolve in alternative namespaces if resolution in the primary namespace fails.
- fn resolve_qpath_anywhere(
- &mut self,
- id: NodeId,
- qself: Option<&QSelf>,
- path: &[Segment],
- primary_ns: Namespace,
- span: Span,
- defer_to_typeck: bool,
- global_by_default: bool,
- crate_lint: CrateLint,
- ) -> Option<PartialRes> {
- let mut fin_res = None;
- // FIXME: can't resolve paths in macro namespace yet, macros are
- // processed by the little special hack below.
- for (i, ns) in [primary_ns, TypeNS, ValueNS, /*MacroNS*/].iter().cloned().enumerate() {
- if i == 0 || ns != primary_ns {
- match self.resolve_qpath(id, qself, path, ns, span, global_by_default, crate_lint) {
- // If defer_to_typeck, then resolution > no resolution,
- // otherwise full resolution > partial resolution > no resolution.
- Some(partial_res) if partial_res.unresolved_segments() == 0 ||
- defer_to_typeck =>
- return Some(partial_res),
- partial_res => if fin_res.is_none() { fin_res = partial_res },
- };
- }
- }
- if primary_ns != MacroNS &&
- (self.macro_names.contains(&path[0].ident.modern()) ||
- self.builtin_macros.get(&path[0].ident.name).cloned()
- .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang) ||
- self.macro_use_prelude.get(&path[0].ident.name).cloned()
- .and_then(NameBinding::macro_kind) == Some(MacroKind::Bang)) {
- // Return some dummy definition, it's enough for error reporting.
- return Some(PartialRes::new(Res::Def(
- DefKind::Macro(MacroKind::Bang),
- DefId::local(CRATE_DEF_INDEX),
- )));
- }
- fin_res
- }
-
- /// Handles paths that may refer to associated items.
- fn resolve_qpath(
- &mut self,
- id: NodeId,
- qself: Option<&QSelf>,
- path: &[Segment],
- ns: Namespace,
- span: Span,
- global_by_default: bool,
- crate_lint: CrateLint,
- ) -> Option<PartialRes> {
- debug!(
- "resolve_qpath(id={:?}, qself={:?}, path={:?}, \
- ns={:?}, span={:?}, global_by_default={:?})",
- id,
- qself,
- path,
- ns,
- span,
- global_by_default,
- );
-
- if let Some(qself) = qself {
- if qself.position == 0 {
- // This is a case like `<T>::B`, where there is no
- // trait to resolve. In that case, we leave the `B`
- // segment to be resolved by type-check.
- return Some(PartialRes::with_unresolved_segments(
- Res::Def(DefKind::Mod, DefId::local(CRATE_DEF_INDEX)), path.len()
- ));
- }
-
- // Make sure `A::B` in `<T as A::B>::C` is a trait item.
- //
- // Currently, `path` names the full item (`A::B::C`, in
- // our example). so we extract the prefix of that that is
- // the trait (the slice upto and including
- // `qself.position`). And then we recursively resolve that,
- // but with `qself` set to `None`.
- //
- // However, setting `qself` to none (but not changing the
- // span) loses the information about where this path
- // *actually* appears, so for the purposes of the crate
- // lint we pass along information that this is the trait
- // name from a fully qualified path, and this also
- // contains the full span (the `CrateLint::QPathTrait`).
- let ns = if qself.position + 1 == path.len() { ns } else { TypeNS };
- let partial_res = self.smart_resolve_path_fragment(
- id,
- None,
- &path[..=qself.position],
- span,
- PathSource::TraitItem(ns),
- CrateLint::QPathTrait {
- qpath_id: id,
- qpath_span: qself.path_span,
- },
- );
-
- // The remaining segments (the `C` in our example) will
- // have to be resolved by type-check, since that requires doing
- // trait resolution.
- return Some(PartialRes::with_unresolved_segments(
- partial_res.base_res(),
- partial_res.unresolved_segments() + path.len() - qself.position - 1,
- ));
- }
-
- let result = match self.resolve_path_without_parent_scope(
- &path,
- Some(ns),
- true,
- span,
- crate_lint,
- ) {
- PathResult::NonModule(path_res) => path_res,
- PathResult::Module(ModuleOrUniformRoot::Module(module)) if !module.is_normal() => {
- PartialRes::new(module.res().unwrap())
- }
- // In `a(::assoc_item)*` `a` cannot be a module. If `a` does resolve to a module we
- // don't report an error right away, but try to fallback to a primitive type.
- // So, we are still able to successfully resolve something like
- //
- // use std::u8; // bring module u8 in scope
- // fn f() -> u8 { // OK, resolves to primitive u8, not to std::u8
- // u8::max_value() // OK, resolves to associated function <u8>::max_value,
- // // not to non-existent std::u8::max_value
- // }
- //
- // Such behavior is required for backward compatibility.
- // The same fallback is used when `a` resolves to nothing.
- PathResult::Module(ModuleOrUniformRoot::Module(_)) |
- PathResult::Failed { .. }
- if (ns == TypeNS || path.len() > 1) &&
- self.primitive_type_table.primitive_types
- .contains_key(&path[0].ident.name) => {
- let prim = self.primitive_type_table.primitive_types[&path[0].ident.name];
- PartialRes::with_unresolved_segments(Res::PrimTy(prim), path.len() - 1)
- }
- PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
- PartialRes::new(module.res().unwrap()),
- PathResult::Failed { is_error_from_last_segment: false, span, label, suggestion } => {
- resolve_error(self, span, ResolutionError::FailedToResolve { label, suggestion });
- PartialRes::new(Res::Err)
- }
- PathResult::Module(..) | PathResult::Failed { .. } => return None,
- PathResult::Indeterminate => bug!("indetermined path result in resolve_qpath"),
- };
-
- if path.len() > 1 && !global_by_default && result.base_res() != Res::Err &&
- path[0].ident.name != kw::PathRoot &&
- path[0].ident.name != kw::DollarCrate {
- let unqualified_result = {
- match self.resolve_path_without_parent_scope(
- &[*path.last().unwrap()],
- Some(ns),
- false,
- span,
- CrateLint::No,
- ) {
- PathResult::NonModule(path_res) => path_res.base_res(),
- PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
- module.res().unwrap(),
- _ => return Some(result),
- }
- };
- if result.base_res() == unqualified_result {
- let lint = lint::builtin::UNUSED_QUALIFICATIONS;
- self.session.buffer_lint(lint, id, span, "unnecessary qualification")
- }
- }
-
- Some(result)
- }
-
- fn resolve_path_without_parent_scope(
- &mut self,
- path: &[Segment],
- opt_ns: Option<Namespace>, // `None` indicates a module path in import
- record_used: bool,
- path_span: Span,
- crate_lint: CrateLint,
- ) -> PathResult<'a> {
- // Macro and import paths must have full parent scope available during resolution,
- // other paths will do okay with parent module alone.
- assert!(opt_ns != None && opt_ns != Some(MacroNS));
- let parent_scope = ParentScope { module: self.current_module, ..self.dummy_parent_scope() };
- self.resolve_path(path, opt_ns, &parent_scope, record_used, path_span, crate_lint)
- }
-
- fn resolve_path(
- &mut self,
- path: &[Segment],
- opt_ns: Option<Namespace>, // `None` indicates a module path in import
- parent_scope: &ParentScope<'a>,
- record_used: bool,
- path_span: Span,
- crate_lint: CrateLint,
- ) -> PathResult<'a> {
- let mut module = None;
- let mut allow_super = true;
- let mut second_binding = None;
- self.current_module = parent_scope.module;
-
- debug!(
- "resolve_path(path={:?}, opt_ns={:?}, record_used={:?}, \
- path_span={:?}, crate_lint={:?})",
- path,
- opt_ns,
- record_used,
- path_span,
- crate_lint,
- );
-
- for (i, &Segment { ident, id }) in path.iter().enumerate() {
- debug!("resolve_path ident {} {:?} {:?}", i, ident, id);
- let record_segment_res = |this: &mut Self, res| {
- if record_used {
- if let Some(id) = id {
- if !this.partial_res_map.contains_key(&id) {
- assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id");
- this.record_partial_res(id, PartialRes::new(res));
- }
- }
- }
- };
-
- let is_last = i == path.len() - 1;
- let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
- let name = ident.name;
-
- allow_super &= ns == TypeNS &&
- (name == kw::SelfLower ||
- name == kw::Super);
-
- if ns == TypeNS {
- if allow_super && name == kw::Super {
- let mut ctxt = ident.span.ctxt().modern();
- let self_module = match i {
- 0 => Some(self.resolve_self(&mut ctxt, self.current_module)),
- _ => match module {
- Some(ModuleOrUniformRoot::Module(module)) => Some(module),
- _ => None,
- },
- };
- if let Some(self_module) = self_module {
- if let Some(parent) = self_module.parent {
- module = Some(ModuleOrUniformRoot::Module(
- self.resolve_self(&mut ctxt, parent)));
- continue;
- }
- }
- let msg = "there are too many initial `super`s.".to_string();
- return PathResult::Failed {
- span: ident.span,
- label: msg,
- suggestion: None,
- is_error_from_last_segment: false,
- };
- }
- if i == 0 {
- if name == kw::SelfLower {
- let mut ctxt = ident.span.ctxt().modern();
- module = Some(ModuleOrUniformRoot::Module(
- self.resolve_self(&mut ctxt, self.current_module)));
- continue;
- }
- if name == kw::PathRoot && ident.span.rust_2018() {
- module = Some(ModuleOrUniformRoot::ExternPrelude);
- continue;
- }
- if name == kw::PathRoot &&
- ident.span.rust_2015() && self.session.rust_2018() {
- // `::a::b` from 2015 macro on 2018 global edition
- module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude);
- continue;
- }
- if name == kw::PathRoot ||
- name == kw::Crate ||
- name == kw::DollarCrate {
- // `::a::b`, `crate::a::b` or `$crate::a::b`
- module = Some(ModuleOrUniformRoot::Module(
- self.resolve_crate_root(ident)));
- continue;
- }
- }
- }
-
- // Report special messages for path segment keywords in wrong positions.
- if ident.is_path_segment_keyword() && i != 0 {
- let name_str = if name == kw::PathRoot {
- "crate root".to_string()
- } else {
- format!("`{}`", name)
- };
- let label = if i == 1 && path[0].ident.name == kw::PathRoot {
- format!("global paths cannot start with {}", name_str)
- } else {
- format!("{} in paths can only be used in start position", name_str)
- };
- return PathResult::Failed {
- span: ident.span,
- label,
- suggestion: None,
- is_error_from_last_segment: false,
- };
- }
-
- let binding = if let Some(module) = module {
- self.resolve_ident_in_module(module, ident, ns, None, record_used, path_span)
- } else if opt_ns.is_none() || opt_ns == Some(MacroNS) {
- assert!(ns == TypeNS);
- let scopes = if opt_ns.is_none() { ScopeSet::Import(ns) } else { ScopeSet::Module };
- self.early_resolve_ident_in_lexical_scope(ident, scopes, parent_scope, record_used,
- record_used, path_span)
- } else {
- let record_used_id =
- if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None };
- match self.resolve_ident_in_lexical_scope(ident, ns, record_used_id, path_span) {
- // we found a locally-imported or available item/module
- Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
- // we found a local variable or type param
- Some(LexicalScopeBinding::Res(res))
- if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
- record_segment_res(self, res);
- return PathResult::NonModule(PartialRes::with_unresolved_segments(
- res, path.len() - 1
- ));
- }
- _ => Err(Determinacy::determined(record_used)),
- }
- };
-
- match binding {
- Ok(binding) => {
- if i == 1 {
- second_binding = Some(binding);
- }
- let res = binding.res();
- let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res);
- if let Some(next_module) = binding.module() {
- module = Some(ModuleOrUniformRoot::Module(next_module));
- record_segment_res(self, res);
- } else if res == Res::ToolMod && i + 1 != path.len() {
- if binding.is_import() {
- self.session.struct_span_err(
- ident.span, "cannot use a tool module through an import"
- ).span_note(
- binding.span, "the tool module imported here"
- ).emit();
- }
- let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
- return PathResult::NonModule(PartialRes::new(res));
- } else if res == Res::Err {
- return PathResult::NonModule(PartialRes::new(Res::Err));
- } else if opt_ns.is_some() && (is_last || maybe_assoc) {
- self.lint_if_path_starts_with_module(
- crate_lint,
- path,
- path_span,
- second_binding,
- );
- return PathResult::NonModule(PartialRes::with_unresolved_segments(
- res, path.len() - i - 1
- ));
- } else {
- let label = format!(
- "`{}` is {} {}, not a module",
- ident,
- res.article(),
- res.descr(),
- );
-
- return PathResult::Failed {
- span: ident.span,
- label,
- suggestion: None,
- is_error_from_last_segment: is_last,
- };
- }
- }
- Err(Undetermined) => return PathResult::Indeterminate,
- Err(Determined) => {
- if let Some(ModuleOrUniformRoot::Module(module)) = module {
- if opt_ns.is_some() && !module.is_normal() {
- return PathResult::NonModule(PartialRes::with_unresolved_segments(
- module.res().unwrap(), path.len() - i
- ));
- }
- }
- let module_res = match module {
- Some(ModuleOrUniformRoot::Module(module)) => module.res(),
- _ => None,
- };
- let (label, suggestion) = if module_res == self.graph_root.res() {
- let is_mod = |res| {
- match res { Res::Def(DefKind::Mod, _) => true, _ => false }
- };
- let mut candidates =
- self.lookup_import_candidates(ident, TypeNS, is_mod);
- candidates.sort_by_cached_key(|c| {
- (c.path.segments.len(), c.path.to_string())
- });
- if let Some(candidate) = candidates.get(0) {
- (
- String::from("unresolved import"),
- Some((
- vec![(ident.span, candidate.path.to_string())],
- String::from("a similar path exists"),
- Applicability::MaybeIncorrect,
- )),
- )
- } else if !ident.is_reserved() {
- (format!("maybe a missing `extern crate {};`?", ident), None)
- } else {
- // the parser will already have complained about the keyword being used
- return PathResult::NonModule(PartialRes::new(Res::Err));
- }
- } else if i == 0 {
- (format!("use of undeclared type or module `{}`", ident), None)
- } else {
- (format!("could not find `{}` in `{}`", ident, path[i - 1].ident), None)
- };
- return PathResult::Failed {
- span: ident.span,
- label,
- suggestion,
- is_error_from_last_segment: is_last,
- };
- }
- }
- }
-
- self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
-
- PathResult::Module(match module {
- Some(module) => module,
- None if path.is_empty() => ModuleOrUniformRoot::CurrentScope,
- _ => span_bug!(path_span, "resolve_path: non-empty path `{:?}` has no module", path),
- })
- }
-
- fn lint_if_path_starts_with_module(
- &self,
- crate_lint: CrateLint,
- path: &[Segment],
- path_span: Span,
- second_binding: Option<&NameBinding<'_>>,
- ) {
- let (diag_id, diag_span) = match crate_lint {
- CrateLint::No => return,
- CrateLint::SimplePath(id) => (id, path_span),
- CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
- CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
- };
-
- let first_name = match path.get(0) {
- // In the 2018 edition this lint is a hard error, so nothing to do
- Some(seg) if seg.ident.span.rust_2015() && self.session.rust_2015() => seg.ident.name,
- _ => return,
- };
-
- // We're only interested in `use` paths which should start with
- // `{{root}}` currently.
- if first_name != kw::PathRoot {
- return
- }
-
- match path.get(1) {
- // If this import looks like `crate::...` it's already good
- Some(Segment { ident, .. }) if ident.name == kw::Crate => return,
- // Otherwise go below to see if it's an extern crate
- Some(_) => {}
- // If the path has length one (and it's `PathRoot` most likely)
- // then we don't know whether we're gonna be importing a crate or an
- // item in our crate. Defer this lint to elsewhere
- None => return,
- }
-
- // If the first element of our path was actually resolved to an
- // `ExternCrate` (also used for `crate::...`) then no need to issue a
- // warning, this looks all good!
- if let Some(binding) = second_binding {
- if let NameBindingKind::Import { directive: d, .. } = binding.kind {
- // Careful: we still want to rewrite paths from
- // renamed extern crates.
- if let ImportDirectiveSubclass::ExternCrate { source: None, .. } = d.subclass {
- return
- }
- }
- }
-
- let diag = lint::builtin::BuiltinLintDiagnostics
- ::AbsPathWithModule(diag_span);
- self.session.buffer_lint_with_diagnostic(
- lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
- diag_id, diag_span,
- "absolute paths must start with `self`, `super`, \
- `crate`, or an external crate name in the 2018 edition",
- diag);
- }
-
- // Validate a local resolution (from ribs).
- fn validate_res_from_ribs(
- &mut self,
- ns: Namespace,
- rib_index: usize,
- res: Res,
- record_used: bool,
- span: Span,
- ) -> Res {
- debug!("validate_res_from_ribs({:?})", res);
- let ribs = &self.ribs[ns][rib_index + 1..];
-
- // An invalid forward use of a type parameter from a previous default.
- if let ForwardTyParamBanRibKind = self.ribs[ns][rib_index].kind {
- if record_used {
- resolve_error(self, span, ResolutionError::ForwardDeclaredTyParam);
- }
- assert_eq!(res, Res::Err);
- return Res::Err;
- }
-
- // An invalid use of a type parameter as the type of a const parameter.
- if let TyParamAsConstParamTy = self.ribs[ns][rib_index].kind {
- if record_used {
- resolve_error(self, span, ResolutionError::ConstParamDependentOnTypeParam);
- }
- assert_eq!(res, Res::Err);
- return Res::Err;
- }
-
- match res {
- Res::Local(_) => {
- use ResolutionError::*;
- let mut res_err = None;
-
- for rib in ribs {
- match rib.kind {
- NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
- ForwardTyParamBanRibKind | TyParamAsConstParamTy => {
- // Nothing to do. Continue.
- }
- ItemRibKind | FnItemRibKind | AssocItemRibKind => {
- // This was an attempt to access an upvar inside a
- // named function item. This is not allowed, so we
- // report an error.
- if record_used {
- // We don't immediately trigger a resolve error, because
- // we want certain other resolution errors (namely those
- // emitted for `ConstantItemRibKind` below) to take
- // precedence.
- res_err = Some(CannotCaptureDynamicEnvironmentInFnItem);
- }
- }
- ConstantItemRibKind => {
- // Still doesn't deal with upvars
- if record_used {
- resolve_error(self, span, AttemptToUseNonConstantValueInConstant);
- }
- return Res::Err;
- }
- }
- }
- if let Some(res_err) = res_err {
- resolve_error(self, span, res_err);
- return Res::Err;
- }
- }
- Res::Def(DefKind::TyParam, _) | Res::SelfTy(..) => {
- for rib in ribs {
- match rib.kind {
- NormalRibKind | AssocItemRibKind |
- ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
- ConstantItemRibKind | TyParamAsConstParamTy => {
- // Nothing to do. Continue.
- }
- ItemRibKind | FnItemRibKind => {
- // This was an attempt to use a type parameter outside its scope.
- if record_used {
- resolve_error(
- self,
- span,
- ResolutionError::GenericParamsFromOuterFunction(res),
- );
- }
- return Res::Err;
- }
- }
- }
- }
- Res::Def(DefKind::ConstParam, _) => {
- let mut ribs = ribs.iter().peekable();
- if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() {
- // When declaring const parameters inside function signatures, the first rib
- // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
- // (spuriously) conflicting with the const param.
- ribs.next();
- }
- for rib in ribs {
- if let ItemRibKind | FnItemRibKind = rib.kind {
- // This was an attempt to use a const parameter outside its scope.
- if record_used {
- resolve_error(
- self,
- span,
- ResolutionError::GenericParamsFromOuterFunction(res),
- );
- }
- return Res::Err;
+ let binding = if let Some(module) = module {
+ self.resolve_ident_in_module(
+ module, ident, ns, parent_scope, record_used, path_span
+ )
+ } else if ribs.is_none() || opt_ns.is_none() || opt_ns == Some(MacroNS) {
+ let scopes = ScopeSet::All(ns, opt_ns.is_none());
+ self.early_resolve_ident_in_lexical_scope(ident, scopes, parent_scope, record_used,
+ record_used, path_span)
+ } else {
+ let record_used_id =
+ if record_used { crate_lint.node_id().or(Some(CRATE_NODE_ID)) } else { None };
+ match self.resolve_ident_in_lexical_scope(
+ ident, ns, parent_scope, record_used_id, path_span, &ribs.unwrap()[ns]
+ ) {
+ // we found a locally-imported or available item/module
+ Some(LexicalScopeBinding::Item(binding)) => Ok(binding),
+ // we found a local variable or type param
+ Some(LexicalScopeBinding::Res(res))
+ if opt_ns == Some(TypeNS) || opt_ns == Some(ValueNS) => {
+ record_segment_res(self, res);
+ return PathResult::NonModule(PartialRes::with_unresolved_segments(
+ res, path.len() - 1
+ ));
}
+ _ => Err(Determinacy::determined(record_used)),
}
- }
- _ => {}
- }
- res
- }
-
- fn lookup_assoc_candidate<FilterFn>(&mut self,
- ident: Ident,
- ns: Namespace,
- filter_fn: FilterFn)
- -> Option<AssocSuggestion>
- where FilterFn: Fn(Res) -> bool
- {
- fn extract_node_id(t: &Ty) -> Option<NodeId> {
- match t.node {
- TyKind::Path(None, _) => Some(t.id),
- TyKind::Rptr(_, ref mut_ty) => extract_node_id(&mut_ty.ty),
- // This doesn't handle the remaining `Ty` variants as they are not
- // that commonly the self_type, it might be interesting to provide
- // support for those in future.
- _ => None,
- }
- }
+ };
- // Fields are generally expected in the same contexts as locals.
- if filter_fn(Res::Local(ast::DUMMY_NODE_ID)) {
- if let Some(node_id) = self.current_self_type.as_ref().and_then(extract_node_id) {
- // Look for a field with the same name in the current self_type.
- if let Some(resolution) = self.partial_res_map.get(&node_id) {
- match resolution.base_res() {
- Res::Def(DefKind::Struct, did) | Res::Def(DefKind::Union, did)
- if resolution.unresolved_segments() == 0 => {
- if let Some(field_names) = self.field_names.get(&did) {
- if field_names.iter().any(|&field_name| ident.name == field_name) {
- return Some(AssocSuggestion::Field);
- }
- }
- }
- _ => {}
+ match binding {
+ Ok(binding) => {
+ if i == 1 {
+ second_binding = Some(binding);
}
- }
- }
- }
-
- // Look for associated items in the current trait.
- if let Some((module, _)) = self.current_trait_ref {
- if let Ok(binding) = self.resolve_ident_in_module(
- ModuleOrUniformRoot::Module(module),
- ident,
- ns,
- None,
- false,
- module.span,
- ) {
- let res = binding.res();
- if filter_fn(res) {
- return Some(if self.has_self.contains(&res.def_id()) {
- AssocSuggestion::MethodWithSelf
+ let res = binding.res();
+ let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res);
+ if let Some(next_module) = binding.module() {
+ module = Some(ModuleOrUniformRoot::Module(next_module));
+ record_segment_res(self, res);
+ } else if res == Res::ToolMod && i + 1 != path.len() {
+ if binding.is_import() {
+ self.session.struct_span_err(
+ ident.span, "cannot use a tool module through an import"
+ ).span_note(
+ binding.span, "the tool module imported here"
+ ).emit();
+ }
+ let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
+ return PathResult::NonModule(PartialRes::new(res));
+ } else if res == Res::Err {
+ return PathResult::NonModule(PartialRes::new(Res::Err));
+ } else if opt_ns.is_some() && (is_last || maybe_assoc) {
+ self.lint_if_path_starts_with_module(
+ crate_lint,
+ path,
+ path_span,
+ second_binding,
+ );
+ return PathResult::NonModule(PartialRes::with_unresolved_segments(
+ res, path.len() - i - 1
+ ));
} else {
- AssocSuggestion::AssocItem
- });
- }
- }
- }
-
- None
- }
-
- fn lookup_typo_candidate<FilterFn>(
- &mut self,
- path: &[Segment],
- ns: Namespace,
- filter_fn: FilterFn,
- span: Span,
- ) -> Option<TypoSuggestion>
- where
- FilterFn: Fn(Res) -> bool,
- {
- let add_module_candidates = |module: Module<'_>, names: &mut Vec<TypoSuggestion>| {
- for (&(ident, _), resolution) in module.resolutions.borrow().iter() {
- if let Some(binding) = resolution.borrow().binding {
- if filter_fn(binding.res()) {
- names.push(TypoSuggestion {
- candidate: ident.name,
- article: binding.res().article(),
- kind: binding.res().descr(),
- });
- }
- }
- }
- };
+ let label = format!(
+ "`{}` is {} {}, not a module",
+ ident,
+ res.article(),
+ res.descr(),
+ );
- let mut names = Vec::new();
- if path.len() == 1 {
- // Search in lexical scope.
- // Walk backwards up the ribs in scope and collect candidates.
- for rib in self.ribs[ns].iter().rev() {
- // Locals and type parameters
- for (ident, &res) in &rib.bindings {
- if filter_fn(res) {
- names.push(TypoSuggestion {
- candidate: ident.name,
- article: res.article(),
- kind: res.descr(),
- });
+ return PathResult::Failed {
+ span: ident.span,
+ label,
+ suggestion: None,
+ is_error_from_last_segment: is_last,
+ };
}
}
- // Items in scope
- if let ModuleRibKind(module) = rib.kind {
- // Items from this module
- add_module_candidates(module, &mut names);
-
- if let ModuleKind::Block(..) = module.kind {
- // We can see through blocks
- } else {
- // Items from the prelude
- if !module.no_implicit_prelude {
- names.extend(self.extern_prelude.clone().iter().flat_map(|(ident, _)| {
- self.crate_loader
- .maybe_process_path_extern(ident.name, ident.span)
- .and_then(|crate_id| {
- let crate_mod = Res::Def(
- DefKind::Mod,
- DefId {
- krate: crate_id,
- index: CRATE_DEF_INDEX,
- },
- );
-
- if filter_fn(crate_mod) {
- Some(TypoSuggestion {
- candidate: ident.name,
- article: "a",
- kind: "crate",
- })
- } else {
- None
- }
- })
- }));
-
- if let Some(prelude) = self.prelude {
- add_module_candidates(prelude, &mut names);
- }
+ Err(Undetermined) => return PathResult::Indeterminate,
+ Err(Determined) => {
+ if let Some(ModuleOrUniformRoot::Module(module)) = module {
+ if opt_ns.is_some() && !module.is_normal() {
+ return PathResult::NonModule(PartialRes::with_unresolved_segments(
+ module.res().unwrap(), path.len() - i
+ ));
}
- break;
}
- }
- }
- // Add primitive types to the mix
- if filter_fn(Res::PrimTy(Bool)) {
- names.extend(
- self.primitive_type_table.primitive_types.iter().map(|(name, _)| {
- TypoSuggestion {
- candidate: *name,
- article: "a",
- kind: "primitive type",
+ let module_res = match module {
+ Some(ModuleOrUniformRoot::Module(module)) => module.res(),
+ _ => None,
+ };
+ let (label, suggestion) = if module_res == self.graph_root.res() {
+ let is_mod = |res| {
+ match res { Res::Def(DefKind::Mod, _) => true, _ => false }
+ };
+ let mut candidates =
+ self.lookup_import_candidates(ident, TypeNS, is_mod);
+ candidates.sort_by_cached_key(|c| {
+ (c.path.segments.len(), c.path.to_string())
+ });
+ if let Some(candidate) = candidates.get(0) {
+ (
+ String::from("unresolved import"),
+ Some((
+ vec![(ident.span, candidate.path.to_string())],
+ String::from("a similar path exists"),
+ Applicability::MaybeIncorrect,
+ )),
+ )
+ } else if !ident.is_reserved() {
+ (format!("maybe a missing crate `{}`?", ident), None)
+ } else {
+ // the parser will already have complained about the keyword being used
+ return PathResult::NonModule(PartialRes::new(Res::Err));
}
- })
- )
- }
- } else {
- // Search in module.
- let mod_path = &path[..path.len() - 1];
- if let PathResult::Module(module) = self.resolve_path_without_parent_scope(
- mod_path, Some(TypeNS), false, span, CrateLint::No
- ) {
- if let ModuleOrUniformRoot::Module(module) = module {
- add_module_candidates(module, &mut names);
+ } else if i == 0 {
+ (format!("use of undeclared type or module `{}`", ident), None)
+ } else {
+ (format!("could not find `{}` in `{}`", ident, path[i - 1].ident), None)
+ };
+ return PathResult::Failed {
+ span: ident.span,
+ label,
+ suggestion,
+ is_error_from_last_segment: is_last,
+ };
}
}
}
- let name = path[path.len() - 1].ident.name;
- // Make sure error reporting is deterministic.
- names.sort_by_cached_key(|suggestion| suggestion.candidate.as_str());
-
- match find_best_match_for_name(
- names.iter().map(|suggestion| &suggestion.candidate),
- &name.as_str(),
- None,
- ) {
- Some(found) if found != name => names
- .into_iter()
- .find(|suggestion| suggestion.candidate == found),
- _ => None,
- }
- }
-
- fn with_resolved_label<F>(&mut self, label: Option<Label>, id: NodeId, f: F)
- where F: FnOnce(&mut Resolver<'_>)
- {
- if let Some(label) = label {
- self.unused_labels.insert(id, label.ident.span);
- self.with_label_rib(|this| {
- let ident = label.ident.modern_and_legacy();
- this.label_ribs.last_mut().unwrap().bindings.insert(ident, id);
- f(this);
- });
- } else {
- f(self);
- }
- }
-
- fn resolve_labeled_block(&mut self, label: Option<Label>, id: NodeId, block: &Block) {
- self.with_resolved_label(label, id, |this| this.visit_block(block));
- }
-
- fn resolve_expr(&mut self, expr: &Expr, parent: Option<&Expr>) {
- // First, record candidate traits for this expression if it could
- // result in the invocation of a method call.
-
- self.record_candidate_traits_for_expr_if_necessary(expr);
-
- // Next, resolve the node.
- match expr.node {
- ExprKind::Path(ref qself, ref path) => {
- self.smart_resolve_path(expr.id, qself.as_ref(), path, PathSource::Expr(parent));
- visit::walk_expr(self, expr);
- }
-
- ExprKind::Struct(ref path, ..) => {
- self.smart_resolve_path(expr.id, None, path, PathSource::Struct);
- visit::walk_expr(self, expr);
- }
-
- ExprKind::Break(Some(label), _) | ExprKind::Continue(Some(label)) => {
- let node_id = self.search_label(label.ident, |rib, ident| {
- rib.bindings.get(&ident.modern_and_legacy()).cloned()
- });
- match node_id {
- None => {
- // Search again for close matches...
- // Picks the first label that is "close enough", which is not necessarily
- // the closest match
- let close_match = self.search_label(label.ident, |rib, ident| {
- let names = rib.bindings.iter().filter_map(|(id, _)| {
- if id.span.ctxt() == label.ident.span.ctxt() {
- Some(&id.name)
- } else {
- None
- }
- });
- find_best_match_for_name(names, &*ident.as_str(), None)
- });
- self.record_partial_res(expr.id, PartialRes::new(Res::Err));
- resolve_error(self,
- label.ident.span,
- ResolutionError::UndeclaredLabel(&label.ident.as_str(),
- close_match));
- }
- Some(node_id) => {
- // Since this res is a label, it is never read.
- self.label_res_map.insert(expr.id, node_id);
- self.unused_labels.remove(&node_id);
- }
- }
-
- // visit `break` argument if any
- visit::walk_expr(self, expr);
- }
-
- ExprKind::Let(ref pats, ref scrutinee) => {
- self.visit_expr(scrutinee);
- self.resolve_pats(pats, PatternSource::Let);
- }
-
- ExprKind::If(ref cond, ref then, ref opt_else) => {
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- self.visit_expr(cond);
- self.visit_block(then);
- self.ribs[ValueNS].pop();
-
- opt_else.as_ref().map(|expr| self.visit_expr(expr));
- }
-
- ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
-
- ExprKind::While(ref subexpression, ref block, label) => {
- self.with_resolved_label(label, expr.id, |this| {
- this.ribs[ValueNS].push(Rib::new(NormalRibKind));
- this.visit_expr(subexpression);
- this.visit_block(block);
- this.ribs[ValueNS].pop();
- });
- }
-
- ExprKind::ForLoop(ref pattern, ref subexpression, ref block, label) => {
- self.visit_expr(subexpression);
- self.ribs[ValueNS].push(Rib::new(NormalRibKind));
- self.resolve_pattern(pattern, PatternSource::For, &mut FxHashMap::default());
-
- self.resolve_labeled_block(label, expr.id, block);
-
- self.ribs[ValueNS].pop();
- }
-
- ExprKind::Block(ref block, label) => self.resolve_labeled_block(label, block.id, block),
-
- // Equivalent to `visit::walk_expr` + passing some context to children.
- ExprKind::Field(ref subexpression, _) => {
- self.resolve_expr(subexpression, Some(expr));
- }
- ExprKind::MethodCall(ref segment, ref arguments) => {
- let mut arguments = arguments.iter();
- self.resolve_expr(arguments.next().unwrap(), Some(expr));
- for argument in arguments {
- self.resolve_expr(argument, None);
- }
- self.visit_path_segment(expr.span, segment);
- }
+ self.lint_if_path_starts_with_module(crate_lint, path, path_span, second_binding);
- ExprKind::Call(ref callee, ref arguments) => {
- self.resolve_expr(callee, Some(expr));
- for argument in arguments {
- self.resolve_expr(argument, None);
- }
- }
- ExprKind::Type(ref type_expr, _) => {
- self.current_type_ascription.push(type_expr.span);
- visit::walk_expr(self, expr);
- self.current_type_ascription.pop();
- }
- // `async |x| ...` gets desugared to `|x| future_from_generator(|| ...)`, so we need to
- // resolve the arguments within the proper scopes so that usages of them inside the
- // closure are detected as upvars rather than normal closure arg usages.
- ExprKind::Closure(
- _, IsAsync::Async { .. }, _,
- ref fn_decl, ref body, _span,
- ) => {
- let rib_kind = NormalRibKind;
- self.ribs[ValueNS].push(Rib::new(rib_kind));
- // Resolve arguments:
- let mut bindings_list = FxHashMap::default();
- for argument in &fn_decl.inputs {
- self.resolve_pattern(&argument.pat, PatternSource::FnParam, &mut bindings_list);
- self.visit_ty(&argument.ty);
- }
- // No need to resolve return type-- the outer closure return type is
- // FunctionRetTy::Default
-
- // Now resolve the inner closure
- {
- // No need to resolve arguments: the inner closure has none.
- // Resolve the return type:
- visit::walk_fn_ret_ty(self, &fn_decl.output);
- // Resolve the body
- self.visit_expr(body);
- }
- self.ribs[ValueNS].pop();
- }
- _ => {
- visit::walk_expr(self, expr);
- }
- }
+ PathResult::Module(match module {
+ Some(module) => module,
+ None if path.is_empty() => ModuleOrUniformRoot::CurrentScope,
+ _ => span_bug!(path_span, "resolve_path: non-empty path `{:?}` has no module", path),
+ })
}
- fn record_candidate_traits_for_expr_if_necessary(&mut self, expr: &Expr) {
- match expr.node {
- ExprKind::Field(_, ident) => {
- // FIXME(#6890): Even though you can't treat a method like a
- // field, we need to add any trait methods we find that match
- // the field name so that we can do some nice error reporting
- // later on in typeck.
- let traits = self.get_traits_containing_item(ident, ValueNS);
- self.trait_map.insert(expr.id, traits);
- }
- ExprKind::MethodCall(ref segment, ..) => {
- debug!("(recording candidate traits for expr) recording traits for {}",
- expr.id);
- let traits = self.get_traits_containing_item(segment.ident, ValueNS);
- self.trait_map.insert(expr.id, traits);
- }
- _ => {
- // Nothing to do.
- }
- }
- }
+ fn lint_if_path_starts_with_module(
+ &self,
+ crate_lint: CrateLint,
+ path: &[Segment],
+ path_span: Span,
+ second_binding: Option<&NameBinding<'_>>,
+ ) {
+ let (diag_id, diag_span) = match crate_lint {
+ CrateLint::No => return,
+ CrateLint::SimplePath(id) => (id, path_span),
+ CrateLint::UsePath { root_id, root_span } => (root_id, root_span),
+ CrateLint::QPathTrait { qpath_id, qpath_span } => (qpath_id, qpath_span),
+ };
- fn get_traits_containing_item(&mut self, mut ident: Ident, ns: Namespace)
- -> Vec<TraitCandidate> {
- debug!("(getting traits containing item) looking for '{}'", ident.name);
+ let first_name = match path.get(0) {
+ // In the 2018 edition this lint is a hard error, so nothing to do
+ Some(seg) if seg.ident.span.rust_2015() && self.session.rust_2015() => seg.ident.name,
+ _ => return,
+ };
- let mut found_traits = Vec::new();
- // Look for the current trait.
- if let Some((module, _)) = self.current_trait_ref {
- if self.resolve_ident_in_module(
- ModuleOrUniformRoot::Module(module),
- ident,
- ns,
- None,
- false,
- module.span,
- ).is_ok() {
- let def_id = module.def_id().unwrap();
- found_traits.push(TraitCandidate { def_id: def_id, import_ids: smallvec![] });
- }
+ // We're only interested in `use` paths which should start with
+ // `{{root}}` currently.
+ if first_name != kw::PathRoot {
+ return
}
- ident.span = ident.span.modern();
- let mut search_module = self.current_module;
- loop {
- self.get_traits_in_module_containing_item(ident, ns, search_module, &mut found_traits);
- search_module = unwrap_or!(
- self.hygienic_lexical_parent(search_module, &mut ident.span), break
- );
+ match path.get(1) {
+ // If this import looks like `crate::...` it's already good
+ Some(Segment { ident, .. }) if ident.name == kw::Crate => return,
+ // Otherwise go below to see if it's an extern crate
+ Some(_) => {}
+ // If the path has length one (and it's `PathRoot` most likely)
+ // then we don't know whether we're gonna be importing a crate or an
+ // item in our crate. Defer this lint to elsewhere
+ None => return,
}
- if let Some(prelude) = self.prelude {
- if !search_module.no_implicit_prelude {
- self.get_traits_in_module_containing_item(ident, ns, prelude, &mut found_traits);
+ // If the first element of our path was actually resolved to an
+ // `ExternCrate` (also used for `crate::...`) then no need to issue a
+ // warning, this looks all good!
+ if let Some(binding) = second_binding {
+ if let NameBindingKind::Import { directive: d, .. } = binding.kind {
+ // Careful: we still want to rewrite paths from
+ // renamed extern crates.
+ if let ImportDirectiveSubclass::ExternCrate { source: None, .. } = d.subclass {
+ return
+ }
}
}
- found_traits
+ let diag = lint::builtin::BuiltinLintDiagnostics
+ ::AbsPathWithModule(diag_span);
+ self.session.buffer_lint_with_diagnostic(
+ lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE,
+ diag_id, diag_span,
+ "absolute paths must start with `self`, `super`, \
+ `crate`, or an external crate name in the 2018 edition",
+ diag);
}
- fn get_traits_in_module_containing_item(&mut self,
- ident: Ident,
- ns: Namespace,
- module: Module<'a>,
- found_traits: &mut Vec<TraitCandidate>) {
- assert!(ns == TypeNS || ns == ValueNS);
- let mut traits = module.traits.borrow_mut();
- if traits.is_none() {
- let mut collected_traits = Vec::new();
- module.for_each_child(|name, ns, binding| {
- if ns != TypeNS { return }
- match binding.res() {
- Res::Def(DefKind::Trait, _) |
- Res::Def(DefKind::TraitAlias, _) => collected_traits.push((name, binding)),
- _ => (),
- }
- });
- *traits = Some(collected_traits.into_boxed_slice());
+ // Validate a local resolution (from ribs).
+ fn validate_res_from_ribs(
+ &mut self,
+ rib_index: usize,
+ res: Res,
+ record_used: bool,
+ span: Span,
+ all_ribs: &[Rib<'a>],
+ ) -> Res {
+ debug!("validate_res_from_ribs({:?})", res);
+ let ribs = &all_ribs[rib_index + 1..];
+
+ // An invalid forward use of a type parameter from a previous default.
+ if let ForwardTyParamBanRibKind = all_ribs[rib_index].kind {
+ if record_used {
+ self.report_error(span, ResolutionError::ForwardDeclaredTyParam);
+ }
+ assert_eq!(res, Res::Err);
+ return Res::Err;
}
- for &(trait_name, binding) in traits.as_ref().unwrap().iter() {
- // Traits have pseudo-modules that can be used to search for the given ident.
- if let Some(module) = binding.module() {
- let mut ident = ident;
- if ident.span.glob_adjust(
- module.expansion,
- binding.span,
- ).is_none() {
- continue
- }
- if self.resolve_ident_in_module_unadjusted(
- ModuleOrUniformRoot::Module(module),
- ident,
- ns,
- false,
- module.span,
- ).is_ok() {
- let import_ids = self.find_transitive_imports(&binding.kind, trait_name);
- let trait_def_id = module.def_id().unwrap();
- found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids });
- }
- } else if let Res::Def(DefKind::TraitAlias, _) = binding.res() {
- // For now, just treat all trait aliases as possible candidates, since we don't
- // know if the ident is somewhere in the transitive bounds.
- let import_ids = self.find_transitive_imports(&binding.kind, trait_name);
- let trait_def_id = binding.res().def_id();
- found_traits.push(TraitCandidate { def_id: trait_def_id, import_ids });
- } else {
- bug!("candidate is not trait or trait alias?")
+ // An invalid use of a type parameter as the type of a const parameter.
+ if let TyParamAsConstParamTy = all_ribs[rib_index].kind {
+ if record_used {
+ self.report_error(span, ResolutionError::ConstParamDependentOnTypeParam);
}
+ assert_eq!(res, Res::Err);
+ return Res::Err;
}
- }
- fn find_transitive_imports(&mut self, mut kind: &NameBindingKind<'_>,
- trait_name: Ident) -> SmallVec<[NodeId; 1]> {
- let mut import_ids = smallvec![];
- while let NameBindingKind::Import { directive, binding, .. } = kind {
- self.maybe_unused_trait_imports.insert(directive.id);
- self.add_to_glob_map(&directive, trait_name);
- import_ids.push(directive.id);
- kind = &binding.kind;
- };
- import_ids
- }
+ match res {
+ Res::Local(_) => {
+ use ResolutionError::*;
+ let mut res_err = None;
- fn lookup_import_candidates_from_module<FilterFn>(&mut self,
- lookup_ident: Ident,
- namespace: Namespace,
- start_module: &'a ModuleData<'a>,
- crate_name: Ident,
- filter_fn: FilterFn)
- -> Vec<ImportSuggestion>
- where FilterFn: Fn(Res) -> bool
- {
- let mut candidates = Vec::new();
- let mut seen_modules = FxHashSet::default();
- let not_local_module = crate_name.name != kw::Crate;
- let mut worklist = vec![(start_module, Vec::<ast::PathSegment>::new(), not_local_module)];
-
- while let Some((in_module,
- path_segments,
- in_module_is_extern)) = worklist.pop() {
- self.populate_module_if_necessary(in_module);
-
- // We have to visit module children in deterministic order to avoid
- // instabilities in reported imports (#43552).
- in_module.for_each_child_stable(|ident, ns, name_binding| {
- // avoid imports entirely
- if name_binding.is_import() && !name_binding.is_extern_crate() { return; }
- // avoid non-importable candidates as well
- if !name_binding.is_importable() { return; }
-
- // collect results based on the filter function
- if ident.name == lookup_ident.name && ns == namespace {
- let res = name_binding.res();
- if filter_fn(res) {
- // create the path
- let mut segms = path_segments.clone();
- if lookup_ident.span.rust_2018() {
- // crate-local absolute paths start with `crate::` in edition 2018
- // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
- segms.insert(
- 0, ast::PathSegment::from_ident(crate_name)
- );
+ for rib in ribs {
+ match rib.kind {
+ NormalRibKind | ModuleRibKind(..) | MacroDefinition(..) |
+ ForwardTyParamBanRibKind | TyParamAsConstParamTy => {
+ // Nothing to do. Continue.
}
-
- segms.push(ast::PathSegment::from_ident(ident));
- let path = Path {
- span: name_binding.span,
- segments: segms,
- };
- // the entity is accessible in the following cases:
- // 1. if it's defined in the same crate, it's always
- // accessible (since private entities can be made public)
- // 2. if it's defined in another crate, it's accessible
- // only if both the module is public and the entity is
- // declared as public (due to pruning, we don't explore
- // outside crate private modules => no need to check this)
- if !in_module_is_extern || name_binding.vis == ty::Visibility::Public {
- let did = match res {
- Res::Def(DefKind::Ctor(..), did) => self.parent(did),
- _ => res.opt_def_id(),
- };
- candidates.push(ImportSuggestion { did, path });
+ ItemRibKind | FnItemRibKind | AssocItemRibKind => {
+ // This was an attempt to access an upvar inside a
+ // named function item. This is not allowed, so we
+ // report an error.
+ if record_used {
+ // We don't immediately trigger a resolve error, because
+ // we want certain other resolution errors (namely those
+ // emitted for `ConstantItemRibKind` below) to take
+ // precedence.
+ res_err = Some(CannotCaptureDynamicEnvironmentInFnItem);
+ }
+ }
+ ConstantItemRibKind => {
+ // Still doesn't deal with upvars
+ if record_used {
+ self.report_error(span, AttemptToUseNonConstantValueInConstant);
+ }
+ return Res::Err;
}
}
}
-
- // collect submodules to explore
- if let Some(module) = name_binding.module() {
- // form the path
- let mut path_segments = path_segments.clone();
- path_segments.push(ast::PathSegment::from_ident(ident));
-
- let is_extern_crate_that_also_appears_in_prelude =
- name_binding.is_extern_crate() &&
- lookup_ident.span.rust_2018();
-
- let is_visible_to_user =
- !in_module_is_extern || name_binding.vis == ty::Visibility::Public;
-
- if !is_extern_crate_that_also_appears_in_prelude && is_visible_to_user {
- // add the module to the lookup
- let is_extern = in_module_is_extern || name_binding.is_extern_crate();
- if seen_modules.insert(module.def_id().unwrap()) {
- worklist.push((module, path_segments, is_extern));
+ if let Some(res_err) = res_err {
+ self.report_error(span, res_err);
+ return Res::Err;
+ }
+ }
+ Res::Def(DefKind::TyParam, _) | Res::SelfTy(..) => {
+ for rib in ribs {
+ match rib.kind {
+ NormalRibKind | AssocItemRibKind |
+ ModuleRibKind(..) | MacroDefinition(..) | ForwardTyParamBanRibKind |
+ ConstantItemRibKind | TyParamAsConstParamTy => {
+ // Nothing to do. Continue.
+ }
+ ItemRibKind | FnItemRibKind => {
+ // This was an attempt to use a type parameter outside its scope.
+ if record_used {
+ self.report_error(
+ span, ResolutionError::GenericParamsFromOuterFunction(res)
+ );
+ }
+ return Res::Err;
}
}
}
- })
- }
-
- candidates
- }
-
- /// When name resolution fails, this method can be used to look up candidate
- /// entities with the expected name. It allows filtering them using the
- /// supplied predicate (which should be used to only accept the types of
- /// definitions expected, e.g., traits). The lookup spans across all crates.
- ///
- /// N.B., the method does not look into imports, but this is not a problem,
- /// since we report the definitions (thus, the de-aliased imports).
- fn lookup_import_candidates<FilterFn>(&mut self,
- lookup_ident: Ident,
- namespace: Namespace,
- filter_fn: FilterFn)
- -> Vec<ImportSuggestion>
- where FilterFn: Fn(Res) -> bool
- {
- let mut suggestions = self.lookup_import_candidates_from_module(
- lookup_ident, namespace, self.graph_root, Ident::with_empty_ctxt(kw::Crate), &filter_fn
- );
-
- if lookup_ident.span.rust_2018() {
- let extern_prelude_names = self.extern_prelude.clone();
- for (ident, _) in extern_prelude_names.into_iter() {
- if let Some(crate_id) = self.crate_loader.maybe_process_path_extern(ident.name,
- ident.span) {
- let crate_root = self.get_module(DefId {
- krate: crate_id,
- index: CRATE_DEF_INDEX,
- });
- self.populate_module_if_necessary(&crate_root);
-
- suggestions.extend(self.lookup_import_candidates_from_module(
- lookup_ident, namespace, crate_root, ident, &filter_fn));
- }
}
- }
-
- suggestions
- }
-
- fn find_module(&mut self, def_id: DefId) -> Option<(Module<'a>, ImportSuggestion)> {
- let mut result = None;
- let mut seen_modules = FxHashSet::default();
- let mut worklist = vec![(self.graph_root, Vec::new())];
-
- while let Some((in_module, path_segments)) = worklist.pop() {
- // abort if the module is already found
- if result.is_some() { break; }
-
- self.populate_module_if_necessary(in_module);
-
- in_module.for_each_child_stable(|ident, _, name_binding| {
- // abort if the module is already found or if name_binding is private external
- if result.is_some() || !name_binding.vis.is_visible_locally() {
- return
+ Res::Def(DefKind::ConstParam, _) => {
+ let mut ribs = ribs.iter().peekable();
+ if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() {
+ // When declaring const parameters inside function signatures, the first rib
+ // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
+ // (spuriously) conflicting with the const param.
+ ribs.next();
}
- if let Some(module) = name_binding.module() {
- // form the path
- let mut path_segments = path_segments.clone();
- path_segments.push(ast::PathSegment::from_ident(ident));
- let module_def_id = module.def_id().unwrap();
- if module_def_id == def_id {
- let path = Path {
- span: name_binding.span,
- segments: path_segments,
- };
- result = Some((module, ImportSuggestion { did: Some(def_id), path }));
- } else {
- // add the module to the lookup
- if seen_modules.insert(module_def_id) {
- worklist.push((module, path_segments));
+ for rib in ribs {
+ if let ItemRibKind | FnItemRibKind = rib.kind {
+ // This was an attempt to use a const parameter outside its scope.
+ if record_used {
+ self.report_error(
+ span, ResolutionError::GenericParamsFromOuterFunction(res)
+ );
}
+ return Res::Err;
}
}
- });
+ }
+ _ => {}
}
-
- result
- }
-
- fn collect_enum_variants(&mut self, def_id: DefId) -> Option<Vec<Path>> {
- self.find_module(def_id).map(|(enum_module, enum_import_suggestion)| {
- self.populate_module_if_necessary(enum_module);
-
- let mut variants = Vec::new();
- enum_module.for_each_child_stable(|ident, _, name_binding| {
- if let Res::Def(DefKind::Variant, _) = name_binding.res() {
- let mut segms = enum_import_suggestion.path.segments.clone();
- segms.push(ast::PathSegment::from_ident(ident));
- variants.push(Path {
- span: name_binding.span,
- segments: segms,
- });
- }
- });
- variants
- })
+ res
}
fn record_partial_res(&mut self, node_id: NodeId, resolution: PartialRes) {
}
}
- fn resolve_visibility(&mut self, vis: &ast::Visibility) -> ty::Visibility {
- match vis.node {
- ast::VisibilityKind::Public => ty::Visibility::Public,
- ast::VisibilityKind::Crate(..) => {
- ty::Visibility::Restricted(DefId::local(CRATE_DEF_INDEX))
- }
- ast::VisibilityKind::Inherited => {
- ty::Visibility::Restricted(self.current_module.normal_ancestor_id)
- }
- ast::VisibilityKind::Restricted { ref path, id, .. } => {
- // For visibilities we are not ready to provide correct implementation of "uniform
- // paths" right now, so on 2018 edition we only allow module-relative paths for now.
- // On 2015 edition visibilities are resolved as crate-relative by default,
- // so we are prepending a root segment if necessary.
- let ident = path.segments.get(0).expect("empty path in visibility").ident;
- let crate_root = if ident.is_path_segment_keyword() {
- None
- } else if ident.span.rust_2018() {
- let msg = "relative paths are not supported in visibilities on 2018 edition";
- self.session.struct_span_err(ident.span, msg)
- .span_suggestion(
- path.span,
- "try",
- format!("crate::{}", path),
- Applicability::MaybeIncorrect,
- )
- .emit();
- return ty::Visibility::Public;
- } else {
- let ctxt = ident.span.ctxt();
- Some(Segment::from_ident(Ident::new(
- kw::PathRoot, path.span.shrink_to_lo().with_ctxt(ctxt)
- )))
- };
-
- let segments = crate_root.into_iter()
- .chain(path.segments.iter().map(|seg| seg.into())).collect::<Vec<_>>();
- let res = self.smart_resolve_path_fragment(
- id,
- None,
- &segments,
- path.span,
- PathSource::Visibility,
- CrateLint::SimplePath(id),
- ).base_res();
- if res == Res::Err {
- ty::Visibility::Public
- } else {
- let vis = ty::Visibility::Restricted(res.def_id());
- if self.is_accessible(vis) {
- vis
- } else {
- self.session.span_err(path.span, "visibilities can only be restricted \
- to ancestor modules");
- ty::Visibility::Public
- }
- }
- }
- }
- }
-
- fn is_accessible(&self, vis: ty::Visibility) -> bool {
- vis.is_accessible_from(self.current_module.normal_ancestor_id, self)
- }
-
fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
vis.is_accessible_from(module.normal_ancestor_id, self)
}
}
fn binding_description(&self, b: &NameBinding<'_>, ident: Ident, from_prelude: bool) -> String {
+ let res = b.res();
if b.span.is_dummy() {
let add_built_in = match b.res() {
// These already contain the "built-in" prefix or look bad with it.
("", "")
};
- let article = if built_in.is_empty() { b.article() } else { "a" };
+ let article = if built_in.is_empty() { res.article() } else { "a" };
format!("{a}{built_in} {thing}{from}",
- a = article, thing = b.descr(), built_in = built_in, from = from)
+ a = article, thing = res.descr(), built_in = built_in, from = from)
} else {
let introduced = if b.is_import() { "imported" } else { "defined" };
format!("the {thing} {introduced} here",
- thing = b.descr(), introduced = introduced)
+ thing = res.descr(), introduced = introduced)
}
}
let note_msg = format!("`{ident}` could{also} refer to {what}",
ident = ident, also = also, what = what);
+ let thing = b.res().descr();
let mut help_msgs = Vec::new();
if b.is_glob_import() && (kind == AmbiguityKind::GlobVsGlob ||
kind == AmbiguityKind::GlobVsExpanded ||
if b.is_extern_crate() && ident.span.rust_2018() {
help_msgs.push(format!(
"use `::{ident}` to refer to this {thing} unambiguously",
- ident = ident, thing = b.descr(),
+ ident = ident, thing = thing,
))
}
if misc == AmbiguityErrorMisc::SuggestCrate {
help_msgs.push(format!(
"use `crate::{ident}` to refer to this {thing} unambiguously",
- ident = ident, thing = b.descr(),
+ ident = ident, thing = thing,
))
} else if misc == AmbiguityErrorMisc::SuggestSelf {
help_msgs.push(format!(
"use `self::{ident}` to refer to this {thing} unambiguously",
- ident = ident, thing = b.descr(),
+ ident = ident, thing = thing,
))
}
let mut reported_spans = FxHashSet::default();
for &PrivacyError(dedup_span, ident, binding) in &self.privacy_errors {
if reported_spans.insert(dedup_span) {
- span_err!(self.session, ident.span, E0603, "{} `{}` is private",
- binding.descr(), ident.name);
+ let mut err = struct_span_err!(
+ self.session,
+ ident.span,
+ E0603,
+ "{} `{}` is private",
+ binding.res().descr(),
+ ident.name,
+ );
+ // FIXME: use the ctor's `def_id` to check wether any of the fields is not visible
+ match binding.kind {
+ NameBindingKind::Res(Res::Def(DefKind::Ctor(
+ CtorOf::Struct,
+ CtorKind::Fn,
+ ), _def_id), _) => {
+ err.note("a tuple struct constructor is private if any of its fields \
+ is private");
+ }
+ NameBindingKind::Res(Res::Def(DefKind::Ctor(
+ CtorOf::Variant,
+ CtorKind::Fn,
+ ), _def_id), _) => {
+ err.note("a tuple variant constructor is private if any of its fields \
+ is private");
+ }
+ _ => {}
+ }
+ err.emit();
}
}
}
for UseError { mut err, candidates, node_id, better } in self.use_injections.drain(..) {
let (span, found_use) = UsePlacementFinder::check(krate, node_id);
if !candidates.is_empty() {
- show_candidates(&mut err, span, &candidates, better, found_use);
+ diagnostics::show_candidates(&mut err, span, &candidates, better, found_use);
}
err.emit();
}
};
let crate_root = self.get_module(DefId { krate: crate_id, index: CRATE_DEF_INDEX });
self.populate_module_if_necessary(&crate_root);
- Some((crate_root, ty::Visibility::Public, DUMMY_SP, Mark::root())
+ Some((crate_root, ty::Visibility::Public, DUMMY_SP, ExpnId::root())
.to_name_binding(self.arenas))
}
})
}
-}
-fn is_self_type(path: &[Segment], namespace: Namespace) -> bool {
- namespace == TypeNS && path.len() == 1 && path[0].ident.name == kw::SelfUpper
-}
+ /// Rustdoc uses this to resolve things in a recoverable way. `ResolutionError<'a>`
+ /// isn't something that can be returned because it can't be made to live that long,
+ /// and also it's a private type. Fortunately rustdoc doesn't need to know the error,
+ /// just that an error occurred.
+ // FIXME(Manishearth): intra-doc links won't get warned of epoch changes.
+ pub fn resolve_str_path_error(
+ &mut self, span: Span, path_str: &str, ns: Namespace, module_id: NodeId
+ ) -> Result<(ast::Path, Res), ()> {
+ let path = if path_str.starts_with("::") {
+ ast::Path {
+ span,
+ segments: iter::once(Ident::with_empty_ctxt(kw::PathRoot))
+ .chain({
+ path_str.split("::").skip(1).map(Ident::from_str)
+ })
+ .map(|i| self.new_ast_path_segment(i))
+ .collect(),
+ }
+ } else {
+ ast::Path {
+ span,
+ segments: path_str
+ .split("::")
+ .map(Ident::from_str)
+ .map(|i| self.new_ast_path_segment(i))
+ .collect(),
+ }
+ };
+ let module = self.block_map.get(&module_id).copied().unwrap_or_else(|| {
+ let def_id = self.definitions.local_def_id(module_id);
+ self.module_map.get(&def_id).copied().unwrap_or(self.graph_root)
+ });
+ let parent_scope = &ParentScope { module, ..self.dummy_parent_scope() };
+ let res = self.resolve_ast_path(&path, ns, parent_scope).map_err(|_| ())?;
+ Ok((path, res))
+ }
+
+ // Resolve a path passed from rustdoc or HIR lowering.
+ fn resolve_ast_path(
+ &mut self,
+ path: &ast::Path,
+ ns: Namespace,
+ parent_scope: &ParentScope<'a>,
+ ) -> Result<Res, (Span, ResolutionError<'a>)> {
+ match self.resolve_path(
+ &Segment::from_path(path), Some(ns), parent_scope, true, path.span, CrateLint::No
+ ) {
+ PathResult::Module(ModuleOrUniformRoot::Module(module)) =>
+ Ok(module.res().unwrap()),
+ PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 =>
+ Ok(path_res.base_res()),
+ PathResult::NonModule(..) => {
+ Err((path.span, ResolutionError::FailedToResolve {
+ label: String::from("type-relative paths are not supported in this context"),
+ suggestion: None,
+ }))
+ }
+ PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
+ PathResult::Failed { span, label, suggestion, .. } => {
+ Err((span, ResolutionError::FailedToResolve {
+ label,
+ suggestion,
+ }))
+ }
+ }
+ }
-fn is_self_value(path: &[Segment], namespace: Namespace) -> bool {
- namespace == ValueNS && path.len() == 1 && path[0].ident.name == kw::SelfLower
+ fn new_ast_path_segment(&self, ident: Ident) -> ast::PathSegment {
+ let mut seg = ast::PathSegment::from_ident(ident);
+ seg.id = self.session.next_node_id();
+ seg
+ }
}
fn names_to_string(idents: &[Ident]) -> String {
.collect::<Vec<_>>())
}
-/// Gets the stringified path for an enum from an `ImportSuggestion` for an enum variant.
-fn import_candidate_to_enum_paths(suggestion: &ImportSuggestion) -> (String, String) {
- let variant_path = &suggestion.path;
- let variant_path_string = path_names_to_string(variant_path);
-
- let path_len = suggestion.path.segments.len();
- let enum_path = ast::Path {
- span: suggestion.path.span,
- segments: suggestion.path.segments[0..path_len - 1].to_vec(),
- };
- let enum_path_string = path_names_to_string(&enum_path);
-
- (variant_path_string, enum_path_string)
-}
-
-/// When an entity with a given name is not available in scope, we search for
-/// entities with that name in all crates. This method allows outputting the
-/// results of this search in a programmer-friendly way
-fn show_candidates(err: &mut DiagnosticBuilder<'_>,
- // This is `None` if all placement locations are inside expansions
- span: Option<Span>,
- candidates: &[ImportSuggestion],
- better: bool,
- found_use: bool) {
-
- // we want consistent results across executions, but candidates are produced
- // by iterating through a hash map, so make sure they are ordered:
- let mut path_strings: Vec<_> =
- candidates.into_iter().map(|c| path_names_to_string(&c.path)).collect();
- path_strings.sort();
-
- let better = if better { "better " } else { "" };
- let msg_diff = match path_strings.len() {
- 1 => " is found in another module, you can import it",
- _ => "s are found in other modules, you can import them",
- };
- let msg = format!("possible {}candidate{} into scope", better, msg_diff);
-
- if let Some(span) = span {
- for candidate in &mut path_strings {
- // produce an additional newline to separate the new use statement
- // from the directly following item.
- let additional_newline = if found_use {
- ""
- } else {
- "\n"
- };
- *candidate = format!("use {};\n{}", candidate, additional_newline);
- }
-
- err.span_suggestions(
- span,
- &msg,
- path_strings.into_iter(),
- Applicability::Unspecified,
- );
- } else {
- let mut msg = msg;
- msg.push(':');
- for candidate in path_strings {
- msg.push('\n');
- msg.push_str(&candidate);
- }
- }
-}
-
/// A somewhat inefficient routine to obtain the name of a module.
fn module_to_string(module: Module<'_>) -> Option<String> {
let mut names = Vec::new();
projects / rustc.git / blobdiff