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android/toolchain/rustc/refs/heads/main/./compiler/rustc_resolve/src/ident.rs
blob: 8ae77902bce603fbab9874dc471cb80949d9b531 [file] [edit]
use Determinacy::*;
use Namespace::*;
use rustc_ast::{self as ast, NodeId};
use rustc_errors::ErrorGuaranteed;
use rustc_hir::def::{DefKind, Namespace, NonMacroAttrKind, PartialRes, PerNS};
use rustc_middle::{bug, ty};
use rustc_session::lint::BuiltinLintDiag;
use rustc_session::lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK;
use rustc_session::parse::feature_err;
use rustc_span::def_id::LocalDefId;
use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext};
use rustc_span::symbol::{Ident, kw};
use rustc_span::{Span, sym};
use tracing::{debug, instrument};
use crate::errors::{ParamKindInEnumDiscriminant, ParamKindInNonTrivialAnonConst};
use crate::imports::Import;
use crate::late::{ConstantHasGenerics, NoConstantGenericsReason, PathSource, Rib, RibKind};
use crate::macros::{MacroRulesScope, sub_namespace_match};
use crate::{
AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, BindingKey, Determinacy, Finalize,
ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot, NameBinding,
NameBindingKind, ParentScope, PathResult, PrivacyError, Res, ResolutionError, Resolver, Scope,
ScopeSet, Segment, ToNameBinding, Used, Weak, errors,
};
type Visibility = ty::Visibility<LocalDefId>;
#[derive(Copy, Clone)]
pub enum UsePrelude {
No,
Yes,
}
impl From<UsePrelude> for bool {
fn from(up: UsePrelude) -> bool {
matches!(up, UsePrelude::Yes)
}
}
impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
/// 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.
pub(crate) fn visit_scopes<T>(
&mut self,
scope_set: ScopeSet<'ra>,
parent_scope: &ParentScope<'ra>,
ctxt: SyntaxContext,
mut visitor: impl FnMut(&mut Self, Scope<'ra>, UsePrelude, SyntaxContext) -> 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 `macro_rules` 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).
let rust_2015 = ctxt.edition().is_rust_2015();
let (ns, macro_kind, is_absolute_path) = match scope_set {
ScopeSet::All(ns) => (ns, None, false),
ScopeSet::AbsolutePath(ns) => (ns, None, true),
ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
ScopeSet::Late(ns, ..) => (ns, None, false),
};
let module = match scope_set {
// Start with the specified module.
ScopeSet::Late(_, module, _) => module,
// Jump out of trait or enum modules, they do not act as scopes.
_ => parent_scope.module.nearest_item_scope(),
};
let mut scope = match ns {
_ if is_absolute_path => Scope::CrateRoot,
TypeNS | ValueNS => Scope::Module(module, None),
MacroNS => Scope::DeriveHelpers(parent_scope.expansion),
};
let mut ctxt = ctxt.normalize_to_macros_2_0();
let mut use_prelude = !module.no_implicit_prelude;
loop {
let visit = match scope {
// Derive helpers are not in scope when resolving derives in the same container.
Scope::DeriveHelpers(expn_id) => {
!(expn_id == parent_scope.expansion && macro_kind == Some(MacroKind::Derive))
}
Scope::DeriveHelpersCompat => true,
Scope::MacroRules(macro_rules_scope) => {
// Use "path compression" on `macro_rules` scope chains. This is an optimization
// used to avoid long scope chains, see the comments on `MacroRulesScopeRef`.
// As another consequence of this optimization visitors never observe invocation
// scopes for macros that were already expanded.
while let MacroRulesScope::Invocation(invoc_id) = macro_rules_scope.get() {
if let Some(next_scope) = self.output_macro_rules_scopes.get(&invoc_id) {
macro_rules_scope.set(next_scope.get());
} else {
break;
}
}
true
}
Scope::CrateRoot => true,
Scope::Module(..) => true,
Scope::MacroUsePrelude => use_prelude || rust_2015,
Scope::BuiltinAttrs => true,
Scope::ExternPrelude => use_prelude || is_absolute_path,
Scope::ToolPrelude => use_prelude,
Scope::StdLibPrelude => use_prelude || ns == MacroNS,
Scope::BuiltinTypes => true,
};
if visit {
let use_prelude = if use_prelude { UsePrelude::Yes } else { UsePrelude::No };
if let break_result @ Some(..) = visitor(self, scope, use_prelude, ctxt) {
return break_result;
}
}
scope = match scope {
Scope::DeriveHelpers(LocalExpnId::ROOT) => Scope::DeriveHelpersCompat,
Scope::DeriveHelpers(expn_id) => {
// Derive helpers are not visible to code generated by bang or derive macros.
let expn_data = expn_id.expn_data();
match expn_data.kind {
ExpnKind::Root
| ExpnKind::Macro(MacroKind::Bang | MacroKind::Derive, _) => {
Scope::DeriveHelpersCompat
}
_ => Scope::DeriveHelpers(expn_data.parent.expect_local()),
}
}
Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.macro_rules),
Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() {
MacroRulesScope::Binding(binding) => {
Scope::MacroRules(binding.parent_macro_rules_scope)
}
MacroRulesScope::Invocation(invoc_id) => {
Scope::MacroRules(self.invocation_parent_scopes[&invoc_id].macro_rules)
}
MacroRulesScope::Empty => Scope::Module(module, None),
},
Scope::CrateRoot => match ns {
TypeNS => {
ctxt.adjust(ExpnId::root());
Scope::ExternPrelude
}
ValueNS | MacroNS => break,
},
Scope::Module(module, prev_lint_id) => {
use_prelude = !module.no_implicit_prelude;
let derive_fallback_lint_id = match scope_set {
ScopeSet::Late(.., lint_id) => lint_id,
_ => None,
};
match self.hygienic_lexical_parent(module, &mut ctxt, derive_fallback_lint_id) {
Some((parent_module, lint_id)) => {
Scope::Module(parent_module, lint_id.or(prev_lint_id))
}
None => {
ctxt.adjust(ExpnId::root());
match ns {
TypeNS => Scope::ExternPrelude,
ValueNS => Scope::StdLibPrelude,
MacroNS => Scope::MacroUsePrelude,
}
}
}
}
Scope::MacroUsePrelude => Scope::StdLibPrelude,
Scope::BuiltinAttrs => 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
}
fn hygienic_lexical_parent(
&mut self,
module: Module<'ra>,
ctxt: &mut SyntaxContext,
derive_fallback_lint_id: Option<NodeId>,
) -> Option<(Module<'ra>, Option<NodeId>)> {
if !module.expansion.outer_expn_is_descendant_of(*ctxt) {
return Some((self.expn_def_scope(ctxt.remove_mark()), None));
}
if let ModuleKind::Block = module.kind {
return Some((module.parent.unwrap().nearest_item_scope(), None));
}
// We need to support the next case under a deprecation warning
// ```
// struct MyStruct;
// ---- begin: this comes from a proc macro derive
// mod implementation_details {
// // Note that `MyStruct` is not in scope here.
// impl SomeTrait for MyStruct { ... }
// }
// ---- end
// ```
// So we have to fall back to the module's parent during lexical resolution in this case.
if derive_fallback_lint_id.is_some() {
if let Some(parent) = module.parent {
// Inner module is inside the macro, parent module is outside of the macro.
if module.expansion != parent.expansion
&& module.expansion.is_descendant_of(parent.expansion)
{
// The macro is a proc macro derive
if let Some(def_id) = module.expansion.expn_data().macro_def_id {
let ext = &self.get_macro_by_def_id(def_id).ext;
if ext.builtin_name.is_none()
&& ext.macro_kind() == MacroKind::Derive
&& parent.expansion.outer_expn_is_descendant_of(*ctxt)
{
return Some((parent, derive_fallback_lint_id));
}
}
}
}
}
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).
///
/// A block's items are above its local variables in the scope hierarchy, regardless of where
/// the items are defined in the block. For example,
/// ```rust
/// fn f() {
/// g(); // Since there are no local variables in scope yet, this resolves to the item.
/// let g = || {};
/// fn g() {}
/// g(); // This resolves to the local variable `g` since it shadows the item.
/// }
/// ```
///
/// Invariant: This must only be called during main resolution, not during
/// import resolution.
#[instrument(level = "debug", skip(self, ribs))]
pub(crate) fn resolve_ident_in_lexical_scope(
&mut self,
mut ident: Ident,
ns: Namespace,
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
ribs: &[Rib<'ra>],
ignore_binding: Option<NameBinding<'ra>>,
) -> Option<LexicalScopeBinding<'ra>> {
assert!(ns == TypeNS || ns == ValueNS);
let orig_ident = ident;
if ident.name == kw::Empty {
return Some(LexicalScopeBinding::Res(Res::Err));
}
let (general_span, normalized_span) = if ident.name == kw::SelfUpper {
// FIXME(jseyfried) improve `Self` hygiene
let empty_span = ident.span.with_ctxt(SyntaxContext::root());
(empty_span, empty_span)
} else if ns == TypeNS {
let normalized_span = ident.span.normalize_to_macros_2_0();
(normalized_span, normalized_span)
} else {
(ident.span.normalize_to_macro_rules(), ident.span.normalize_to_macros_2_0())
};
ident.span = general_span;
let normalized_ident = Ident { span: normalized_span, ..ident };
// Walk backwards up the ribs in scope.
let mut module = self.graph_root;
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
// (macro 2.0 hygiene) or local variables (`macro_rules` hygiene).
let rib_ident = if ribs[i].kind.contains_params() { normalized_ident } else { ident };
if let Some((original_rib_ident_def, res)) = ribs[i].bindings.get_key_value(&rib_ident)
{
// The ident resolves to a type parameter or local variable.
return Some(LexicalScopeBinding::Res(self.validate_res_from_ribs(
i,
rib_ident,
*res,
finalize.map(|finalize| finalize.path_span),
*original_rib_ident_def,
ribs,
)));
}
module = match ribs[i].kind {
RibKind::Module(module) => module,
RibKind::MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => {
// If an invocation of this macro created `ident`, give up on `ident`
// and switch to `ident`'s source from the macro definition.
ident.span.remove_mark();
continue;
}
_ => continue,
};
match module.kind {
ModuleKind::Block => {} // We can see through blocks
_ => break,
}
let item = self.resolve_ident_in_module_unadjusted(
ModuleOrUniformRoot::Module(module),
ident,
ns,
parent_scope,
finalize.map(|finalize| Finalize { used: Used::Scope, ..finalize }),
ignore_binding,
None,
);
if let Ok(binding) = item {
// The ident resolves to an item.
return Some(LexicalScopeBinding::Item(binding));
}
}
self.early_resolve_ident_in_lexical_scope(
orig_ident,
ScopeSet::Late(ns, module, finalize.map(|finalize| finalize.node_id)),
parent_scope,
finalize,
finalize.is_some(),
ignore_binding,
None,
)
.ok()
.map(LexicalScopeBinding::Item)
}
/// Resolve an identifier in lexical scope.
/// This is a variation of `fn resolve_ident_in_lexical_scope` that can be run during
/// expansion and import resolution (perhaps they can be merged in the future).
/// The function is used for resolving initial segments of macro paths (e.g., `foo` in
/// `foo::bar!();` or `foo!();`) and also for import paths on 2018 edition.
#[instrument(level = "debug", skip(self))]
pub(crate) fn early_resolve_ident_in_lexical_scope(
&mut self,
orig_ident: Ident,
scope_set: ScopeSet<'ra>,
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
force: bool,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> Result<NameBinding<'ra>, Determinacy> {
bitflags::bitflags! {
#[derive(Clone, Copy)]
struct Flags: u8 {
const MACRO_RULES = 1 << 0;
const MODULE = 1 << 1;
const MISC_SUGGEST_CRATE = 1 << 2;
const MISC_SUGGEST_SELF = 1 << 3;
const MISC_FROM_PRELUDE = 1 << 4;
}
}
assert!(force || finalize.is_none()); // `finalize` implies `force`
// Make sure `self`, `super` etc produce an error when passed to here.
if orig_ident.is_path_segment_keyword() {
return Err(Determinacy::Determined);
}
let (ns, macro_kind) = match scope_set {
ScopeSet::All(ns) => (ns, None),
ScopeSet::AbsolutePath(ns) => (ns, None),
ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind)),
ScopeSet::Late(ns, ..) => (ns, None),
};
// This is *the* result, resolution from the scope closest to the resolved identifier.
// However, sometimes this result is "weak" because it comes from a glob import or
// a macro expansion, and in this case it cannot shadow names from outer scopes, e.g.
// mod m { ... } // solution in outer scope
// {
// use prefix::*; // imports another `m` - innermost solution
// // weak, cannot shadow the outer `m`, need to report ambiguity error
// m::mac!();
// }
// So we have to save the innermost solution and continue searching in outer scopes
// to detect potential ambiguities.
let mut innermost_result: Option<(NameBinding<'_>, Flags)> = None;
let mut determinacy = Determinacy::Determined;
// Go through all the scopes and try to resolve the name.
let break_result = self.visit_scopes(
scope_set,
parent_scope,
orig_ident.span.ctxt(),
|this, scope, use_prelude, ctxt| {
let ident = Ident::new(orig_ident.name, orig_ident.span.with_ctxt(ctxt));
let result = match scope {
Scope::DeriveHelpers(expn_id) => {
if let Some(binding) = this.helper_attrs.get(&expn_id).and_then(|attrs| {
attrs.iter().rfind(|(i, _)| ident == *i).map(|(_, binding)| *binding)
}) {
Ok((binding, Flags::empty()))
} else {
Err(Determinacy::Determined)
}
}
Scope::DeriveHelpersCompat => {
// FIXME: Try running this logic earlier, to allocate name bindings for
// legacy derive helpers when creating an attribute invocation with
// following derives. Legacy derive helpers are not common, so it shouldn't
// affect performance. It should also allow to remove the `derives`
// component from `ParentScope`.
let mut result = Err(Determinacy::Determined);
for derive in parent_scope.derives {
let parent_scope = &ParentScope { derives: &[], ..*parent_scope };
match this.resolve_macro_path(
derive,
Some(MacroKind::Derive),
parent_scope,
true,
force,
ignore_import,
) {
Ok((Some(ext), _)) => {
if ext.helper_attrs.contains(&ident.name) {
let binding = (
Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat),
Visibility::Public,
derive.span,
LocalExpnId::ROOT,
)
.to_name_binding(this.arenas);
result = Ok((binding, Flags::empty()));
break;
}
}
Ok(_) | Err(Determinacy::Determined) => {}
Err(Determinacy::Undetermined) => {
result = Err(Determinacy::Undetermined)
}
}
}
result
}
Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() {
MacroRulesScope::Binding(macro_rules_binding)
if ident == macro_rules_binding.ident =>
{
Ok((macro_rules_binding.binding, Flags::MACRO_RULES))
}
MacroRulesScope::Invocation(_) => Err(Determinacy::Undetermined),
_ => Err(Determinacy::Determined),
},
Scope::CrateRoot => {
let root_ident = Ident::new(kw::PathRoot, ident.span);
let root_module = this.resolve_crate_root(root_ident);
let binding = this.resolve_ident_in_module_ext(
ModuleOrUniformRoot::Module(root_module),
ident,
ns,
parent_scope,
finalize,
ignore_binding,
ignore_import,
);
match binding {
Ok(binding) => Ok((binding, Flags::MODULE | Flags::MISC_SUGGEST_CRATE)),
Err((Determinacy::Undetermined, Weak::No)) => {
return Some(Err(Determinacy::determined(force)));
}
Err((Determinacy::Undetermined, Weak::Yes)) => {
Err(Determinacy::Undetermined)
}
Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
}
}
Scope::Module(module, derive_fallback_lint_id) => {
let adjusted_parent_scope = &ParentScope { module, ..*parent_scope };
let binding = this.resolve_ident_in_module_unadjusted_ext(
ModuleOrUniformRoot::Module(module),
ident,
ns,
adjusted_parent_scope,
!matches!(scope_set, ScopeSet::Late(..)),
finalize.map(|finalize| Finalize { used: Used::Scope, ..finalize }),
ignore_binding,
ignore_import,
);
match binding {
Ok(binding) => {
if let Some(lint_id) = derive_fallback_lint_id {
this.lint_buffer.buffer_lint(
PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
lint_id,
orig_ident.span,
BuiltinLintDiag::ProcMacroDeriveResolutionFallback {
span: orig_ident.span,
ns,
ident,
},
);
}
let misc_flags = if module == this.graph_root {
Flags::MISC_SUGGEST_CRATE
} else if module.is_normal() {
Flags::MISC_SUGGEST_SELF
} else {
Flags::empty()
};
Ok((binding, Flags::MODULE | misc_flags))
}
Err((Determinacy::Undetermined, Weak::No)) => {
return Some(Err(Determinacy::determined(force)));
}
Err((Determinacy::Undetermined, Weak::Yes)) => {
Err(Determinacy::Undetermined)
}
Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
}
}
Scope::MacroUsePrelude => {
match this.macro_use_prelude.get(&ident.name).cloned() {
Some(binding) => Ok((binding, Flags::MISC_FROM_PRELUDE)),
None => Err(Determinacy::determined(
this.graph_root.unexpanded_invocations.borrow().is_empty(),
)),
}
}
Scope::BuiltinAttrs => match this.builtin_attrs_bindings.get(&ident.name) {
Some(binding) => Ok((*binding, Flags::empty())),
None => Err(Determinacy::Determined),
},
Scope::ExternPrelude => {
match this.extern_prelude_get(ident, finalize.is_some()) {
Some(binding) => Ok((binding, Flags::empty())),
None => Err(Determinacy::determined(
this.graph_root.unexpanded_invocations.borrow().is_empty(),
)),
}
}
Scope::ToolPrelude => match this.registered_tool_bindings.get(&ident) {
Some(binding) => Ok((*binding, Flags::empty())),
None => Err(Determinacy::Determined),
},
Scope::StdLibPrelude => {
let mut result = Err(Determinacy::Determined);
if let Some(prelude) = this.prelude {
if let Ok(binding) = this.resolve_ident_in_module_unadjusted(
ModuleOrUniformRoot::Module(prelude),
ident,
ns,
parent_scope,
None,
ignore_binding,
ignore_import,
) {
if matches!(use_prelude, UsePrelude::Yes)
|| this.is_builtin_macro(binding.res())
{
result = Ok((binding, Flags::MISC_FROM_PRELUDE));
}
}
}
result
}
Scope::BuiltinTypes => match this.builtin_types_bindings.get(&ident.name) {
Some(binding) => {
if matches!(ident.name, sym::f16)
&& !this.tcx.features().f16
&& !ident.span.allows_unstable(sym::f16)
&& finalize.is_some()
&& innermost_result.is_none()
{
feature_err(
this.tcx.sess,
sym::f16,
ident.span,
"the type `f16` is unstable",
)
.emit();
}
if matches!(ident.name, sym::f128)
&& !this.tcx.features().f128
&& !ident.span.allows_unstable(sym::f128)
&& finalize.is_some()
&& innermost_result.is_none()
{
feature_err(
this.tcx.sess,
sym::f128,
ident.span,
"the type `f128` is unstable",
)
.emit();
}
Ok((*binding, Flags::empty()))
}
None => Err(Determinacy::Determined),
},
};
match result {
Ok((binding, flags))
if sub_namespace_match(binding.macro_kind(), macro_kind) =>
{
if finalize.is_none() || matches!(scope_set, ScopeSet::Late(..)) {
return Some(Ok(binding));
}
if let Some((innermost_binding, innermost_flags)) = innermost_result {
// Found another solution, if the first one was "weak", report an error.
let (res, innermost_res) = (binding.res(), innermost_binding.res());
if res != innermost_res {
let is_builtin = |res| {
matches!(res, Res::NonMacroAttr(NonMacroAttrKind::Builtin(..)))
};
let derive_helper =
Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper);
let derive_helper_compat =
Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat);
let ambiguity_error_kind = if is_builtin(innermost_res)
|| is_builtin(res)
{
Some(AmbiguityKind::BuiltinAttr)
} else if innermost_res == derive_helper_compat
|| res == derive_helper_compat && innermost_res != derive_helper
{
Some(AmbiguityKind::DeriveHelper)
} else if innermost_flags.contains(Flags::MACRO_RULES)
&& flags.contains(Flags::MODULE)
&& !this.disambiguate_macro_rules_vs_modularized(
innermost_binding,
binding,
)
|| flags.contains(Flags::MACRO_RULES)
&& innermost_flags.contains(Flags::MODULE)
&& !this.disambiguate_macro_rules_vs_modularized(
binding,
innermost_binding,
)
{
Some(AmbiguityKind::MacroRulesVsModularized)
} else if innermost_binding.is_glob_import() {
Some(AmbiguityKind::GlobVsOuter)
} else if innermost_binding
.may_appear_after(parent_scope.expansion, binding)
{
Some(AmbiguityKind::MoreExpandedVsOuter)
} else {
None
};
if let Some(kind) = ambiguity_error_kind {
let misc = |f: Flags| {
if f.contains(Flags::MISC_SUGGEST_CRATE) {
AmbiguityErrorMisc::SuggestCrate
} else if f.contains(Flags::MISC_SUGGEST_SELF) {
AmbiguityErrorMisc::SuggestSelf
} else if f.contains(Flags::MISC_FROM_PRELUDE) {
AmbiguityErrorMisc::FromPrelude
} else {
AmbiguityErrorMisc::None
}
};
this.ambiguity_errors.push(AmbiguityError {
kind,
ident: orig_ident,
b1: innermost_binding,
b2: binding,
warning: false,
misc1: misc(innermost_flags),
misc2: misc(flags),
});
return Some(Ok(innermost_binding));
}
}
} else {
// Found the first solution.
innermost_result = Some((binding, flags));
}
}
Ok(..) | Err(Determinacy::Determined) => {}
Err(Determinacy::Undetermined) => determinacy = Determinacy::Undetermined,
}
None
},
);
if let Some(break_result) = break_result {
return break_result;
}
// The first found solution was the only one, return it.
if let Some((binding, _)) = innermost_result {
return Ok(binding);
}
Err(Determinacy::determined(determinacy == Determinacy::Determined || force))
}
#[instrument(level = "debug", skip(self))]
pub(crate) fn maybe_resolve_ident_in_module(
&mut self,
module: ModuleOrUniformRoot<'ra>,
ident: Ident,
ns: Namespace,
parent_scope: &ParentScope<'ra>,
ignore_import: Option<Import<'ra>>,
) -> Result<NameBinding<'ra>, Determinacy> {
self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, None, None, ignore_import)
.map_err(|(determinacy, _)| determinacy)
}
#[instrument(level = "debug", skip(self))]
pub(crate) fn resolve_ident_in_module(
&mut self,
module: ModuleOrUniformRoot<'ra>,
ident: Ident,
ns: Namespace,
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> Result<NameBinding<'ra>, Determinacy> {
self.resolve_ident_in_module_ext(
module,
ident,
ns,
parent_scope,
finalize,
ignore_binding,
ignore_import,
)
.map_err(|(determinacy, _)| determinacy)
}
#[instrument(level = "debug", skip(self))]
fn resolve_ident_in_module_ext(
&mut self,
module: ModuleOrUniformRoot<'ra>,
mut ident: Ident,
ns: Namespace,
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> Result<NameBinding<'ra>, (Determinacy, Weak)> {
let tmp_parent_scope;
let mut adjusted_parent_scope = parent_scope;
match module {
ModuleOrUniformRoot::Module(m) => {
if let Some(def) = ident.span.normalize_to_macros_2_0_and_adjust(m.expansion) {
tmp_parent_scope =
ParentScope { module: self.expn_def_scope(def), ..*parent_scope };
adjusted_parent_scope = &tmp_parent_scope;
}
}
ModuleOrUniformRoot::ExternPrelude => {
ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root());
}
ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => {
// No adjustments
}
}
self.resolve_ident_in_module_unadjusted_ext(
module,
ident,
ns,
adjusted_parent_scope,
false,
finalize,
ignore_binding,
ignore_import,
)
}
#[instrument(level = "debug", skip(self))]
fn resolve_ident_in_module_unadjusted(
&mut self,
module: ModuleOrUniformRoot<'ra>,
ident: Ident,
ns: Namespace,
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> Result<NameBinding<'ra>, Determinacy> {
self.resolve_ident_in_module_unadjusted_ext(
module,
ident,
ns,
parent_scope,
false,
finalize,
ignore_binding,
ignore_import,
)
.map_err(|(determinacy, _)| determinacy)
}
/// Attempts to resolve `ident` in namespaces `ns` of `module`.
/// Invariant: if `finalize` is `Some`, expansion and import resolution must be complete.
#[instrument(level = "debug", skip(self))]
fn resolve_ident_in_module_unadjusted_ext(
&mut self,
module: ModuleOrUniformRoot<'ra>,
ident: Ident,
ns: Namespace,
parent_scope: &ParentScope<'ra>,
restricted_shadowing: bool,
finalize: Option<Finalize>,
// This binding should be ignored during in-module resolution, so that we don't get
// "self-confirming" import resolutions during import validation and checking.
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> Result<NameBinding<'ra>, (Determinacy, Weak)> {
let module = match module {
ModuleOrUniformRoot::Module(module) => module,
ModuleOrUniformRoot::CrateRootAndExternPrelude => {
assert!(!restricted_shadowing);
let binding = self.early_resolve_ident_in_lexical_scope(
ident,
ScopeSet::AbsolutePath(ns),
parent_scope,
finalize,
finalize.is_some(),
ignore_binding,
ignore_import,
);
return binding.map_err(|determinacy| (determinacy, Weak::No));
}
ModuleOrUniformRoot::ExternPrelude => {
assert!(!restricted_shadowing);
return if ns != TypeNS {
Err((Determined, Weak::No))
} else if let Some(binding) = self.extern_prelude_get(ident, finalize.is_some()) {
Ok(binding)
} else if !self.graph_root.unexpanded_invocations.borrow().is_empty() {
// Macro-expanded `extern crate` items can add names to extern prelude.
Err((Undetermined, Weak::No))
} else {
Err((Determined, Weak::No))
};
}
ModuleOrUniformRoot::CurrentScope => {
assert!(!restricted_shadowing);
if ns == TypeNS {
if ident.name == kw::Crate || ident.name == kw::DollarCrate {
let module = self.resolve_crate_root(ident);
return Ok(self.module_self_bindings[&module]);
} else if ident.name == kw::Super || ident.name == kw::SelfLower {
// FIXME: Implement these with renaming requirements so that e.g.
// `use super;` doesn't work, but `use super as name;` does.
// Fall through here to get an error from `early_resolve_...`.
}
}
let binding = self.early_resolve_ident_in_lexical_scope(
ident,
ScopeSet::All(ns),
parent_scope,
finalize,
finalize.is_some(),
ignore_binding,
ignore_import,
);
return binding.map_err(|determinacy| (determinacy, Weak::No));
}
};
let key = BindingKey::new(ident, ns);
let resolution =
self.resolution(module, key).try_borrow_mut().map_err(|_| (Determined, Weak::No))?; // This happens when there is a cycle of imports.
// If the primary binding is unusable, search further and return the shadowed glob
// binding if it exists. What we really want here is having two separate scopes in
// a module - one for non-globs and one for globs, but until that's done use this
// hack to avoid inconsistent resolution ICEs during import validation.
let binding = [resolution.binding, resolution.shadowed_glob]
.into_iter()
.find_map(|binding| if binding == ignore_binding { None } else { binding });
if let Some(Finalize { path_span, report_private, used, root_span, .. }) = finalize {
let Some(binding) = binding else {
return Err((Determined, Weak::No));
};
if !self.is_accessible_from(binding.vis, parent_scope.module) {
if report_private {
self.privacy_errors.push(PrivacyError {
ident,
binding,
dedup_span: path_span,
outermost_res: None,
parent_scope: *parent_scope,
single_nested: path_span != root_span,
});
} else {
return Err((Determined, Weak::No));
}
}
// Forbid expanded shadowing to avoid time travel.
if let Some(shadowed_glob) = resolution.shadowed_glob
&& restricted_shadowing
&& binding.expansion != LocalExpnId::ROOT
&& binding.res() != shadowed_glob.res()
{
self.ambiguity_errors.push(AmbiguityError {
kind: AmbiguityKind::GlobVsExpanded,
ident,
b1: binding,
b2: shadowed_glob,
warning: false,
misc1: AmbiguityErrorMisc::None,
misc2: AmbiguityErrorMisc::None,
});
}
if !restricted_shadowing
&& binding.expansion != LocalExpnId::ROOT
&& let NameBindingKind::Import { import, .. } = binding.kind
&& matches!(import.kind, ImportKind::MacroExport)
{
self.macro_expanded_macro_export_errors.insert((path_span, binding.span));
}
self.record_use(ident, binding, used);
return Ok(binding);
}
let check_usable = |this: &mut Self, binding: NameBinding<'ra>| {
let usable = this.is_accessible_from(binding.vis, parent_scope.module);
if usable { Ok(binding) } else { Err((Determined, Weak::No)) }
};
// Items and single imports are not shadowable, if we have one, then it's determined.
if let Some(binding) = binding {
if !binding.is_glob_import() {
return check_usable(self, binding);
}
}
// --- From now on we either have a glob resolution or no resolution. ---
// Check if one of single imports can still define the name,
// if it can then our result is not determined and can be invalidated.
for single_import in &resolution.single_imports {
if ignore_import == Some(*single_import) {
// This branch handles a cycle in single imports.
//
// For example:
// ```
// use a::b;
// use b as a;
// ```
// 1. Record `use a::b` as the `ignore_import` and attempt to locate `a` in the
// current module.
// 2. Encounter the import `use b as a`, which is a `single_import` for `a`,
// and try to find `b` in the current module.
// 3. Re-encounter the `use a::b` import since it's a `single_import` of `b`.
// This leads to entering this branch.
continue;
}
if !self.is_accessible_from(single_import.vis, parent_scope.module) {
continue;
}
if let Some(ignored) = ignore_binding
&& let NameBindingKind::Import { import, .. } = ignored.kind
&& import == *single_import
{
// Ignore not just the binding itself, but if it has a shadowed_glob,
// ignore that, too, because this loop is supposed to only process
// named imports.
continue;
}
let Some(module) = single_import.imported_module.get() else {
return Err((Undetermined, Weak::No));
};
let ImportKind::Single { source, target, target_bindings, .. } = &single_import.kind
else {
unreachable!();
};
if source != target {
// This branch allows the binding to be defined or updated later if the target name
// can hide the source.
if target_bindings.iter().all(|binding| binding.get().is_none()) {
// None of the target bindings are available, so we can't determine
// if this binding is correct or not.
// See more details in #124840
return Err((Undetermined, Weak::No));
} else if target_bindings[ns].get().is_none() && binding.is_some() {
// `binding.is_some()` avoids the condition where the binding
// truly doesn't exist in this namespace and should return `Err(Determined)`.
return Err((Undetermined, Weak::No));
}
}
match self.resolve_ident_in_module(
module,
*source,
ns,
&single_import.parent_scope,
None,
ignore_binding,
ignore_import,
) {
Err(Determined) => continue,
Ok(binding)
if !self.is_accessible_from(binding.vis, single_import.parent_scope.module) =>
{
continue;
}
Ok(_) | Err(Undetermined) => return Err((Undetermined, Weak::No)),
}
}
// So we have a resolution that's from a glob import. This resolution is determined
// if it cannot be shadowed by some new item/import expanded from a macro.
// This happens either if there are no unexpanded macros, or expanded names cannot
// shadow globs (that happens in macro namespace or with restricted shadowing).
//
// Additionally, any macro in any module can plant names in the root module if it creates
// `macro_export` macros, so the root module effectively has unresolved invocations if any
// module has unresolved invocations.
// However, it causes resolution/expansion to stuck too often (#53144), so, to make
// progress, we have to ignore those potential unresolved invocations from other modules
// and prohibit access to macro-expanded `macro_export` macros instead (unless restricted
// shadowing is enabled, see `macro_expanded_macro_export_errors`).
if let Some(binding) = binding {
if binding.determined() || ns == MacroNS || restricted_shadowing {
return check_usable(self, binding);
} else {
return Err((Undetermined, Weak::No));
}
}
// --- From now on we have no resolution. ---
// Now we are in situation when new item/import can appear only from a glob or a macro
// expansion. With restricted shadowing names from globs and macro expansions cannot
// shadow names from outer scopes, so we can freely fallback from module search to search
// in outer scopes. For `early_resolve_ident_in_lexical_scope` to continue search in outer
// scopes we return `Undetermined` with `Weak::Yes`.
// Check if one of unexpanded macros can still define the name,
// if it can then our "no resolution" result is not determined and can be invalidated.
if !module.unexpanded_invocations.borrow().is_empty() {
return Err((Undetermined, Weak::Yes));
}
// Check if one of glob imports can still define the name,
// if it can then our "no resolution" result is not determined and can be invalidated.
for glob_import in module.globs.borrow().iter() {
if ignore_import == Some(*glob_import) {
continue;
}
if !self.is_accessible_from(glob_import.vis, parent_scope.module) {
continue;
}
let module = match glob_import.imported_module.get() {
Some(ModuleOrUniformRoot::Module(module)) => module,
Some(_) => continue,
None => return Err((Undetermined, Weak::Yes)),
};
let tmp_parent_scope;
let (mut adjusted_parent_scope, mut ident) =
(parent_scope, ident.normalize_to_macros_2_0());
match ident.span.glob_adjust(module.expansion, glob_import.span) {
Some(Some(def)) => {
tmp_parent_scope =
ParentScope { module: self.expn_def_scope(def), ..*parent_scope };
adjusted_parent_scope = &tmp_parent_scope;
}
Some(None) => {}
None => continue,
};
let result = self.resolve_ident_in_module_unadjusted(
ModuleOrUniformRoot::Module(module),
ident,
ns,
adjusted_parent_scope,
None,
ignore_binding,
ignore_import,
);
match result {
Err(Determined) => continue,
Ok(binding)
if !self.is_accessible_from(binding.vis, glob_import.parent_scope.module) =>
{
continue;
}
Ok(_) | Err(Undetermined) => return Err((Undetermined, Weak::Yes)),
}
}
// No resolution and no one else can define the name - determinate error.
Err((Determined, Weak::No))
}
/// Validate a local resolution (from ribs).
#[instrument(level = "debug", skip(self, all_ribs))]
fn validate_res_from_ribs(
&mut self,
rib_index: usize,
rib_ident: Ident,
mut res: Res,
finalize: Option<Span>,
original_rib_ident_def: Ident,
all_ribs: &[Rib<'ra>],
) -> Res {
debug!("validate_res_from_ribs({:?})", res);
let ribs = &all_ribs[rib_index + 1..];
// An invalid forward use of a generic parameter from a previous default.
if let RibKind::ForwardGenericParamBan = all_ribs[rib_index].kind {
if let Some(span) = finalize {
let res_error = if rib_ident.name == kw::SelfUpper {
ResolutionError::SelfInGenericParamDefault
} else {
ResolutionError::ForwardDeclaredGenericParam
};
self.report_error(span, res_error);
}
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 {
RibKind::Normal
| RibKind::FnOrCoroutine
| RibKind::Module(..)
| RibKind::MacroDefinition(..)
| RibKind::ForwardGenericParamBan => {
// Nothing to do. Continue.
}
RibKind::Item(..) | RibKind::AssocItem => {
// This was an attempt to access an upvar inside a
// named function item. This is not allowed, so we
// report an error.
if let Some(span) = finalize {
// 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((span, CannotCaptureDynamicEnvironmentInFnItem));
}
}
RibKind::ConstantItem(_, item) => {
// Still doesn't deal with upvars
if let Some(span) = finalize {
let (span, resolution_error) = match item {
None if rib_ident.as_str() == "self" => (span, LowercaseSelf),
None => {
// If we have a `let name = expr;`, we have the span for
// `name` and use that to see if it is followed by a type
// specifier. If not, then we know we need to suggest
// `const name: Ty = expr;`. This is a heuristic, it will
// break down in the presence of macros.
let sm = self.tcx.sess.source_map();
let type_span = match sm.span_look_ahead(
original_rib_ident_def.span,
":",
None,
) {
None => {
Some(original_rib_ident_def.span.shrink_to_hi())
}
Some(_) => None,
};
(rib_ident.span, AttemptToUseNonConstantValueInConstant {
ident: original_rib_ident_def,
suggestion: "const",
current: "let",
type_span,
})
}
Some((ident, kind)) => {
(span, AttemptToUseNonConstantValueInConstant {
ident,
suggestion: "let",
current: kind.as_str(),
type_span: None,
})
}
};
self.report_error(span, resolution_error);
}
return Res::Err;
}
RibKind::ConstParamTy => {
if let Some(span) = finalize {
self.report_error(span, ParamInTyOfConstParam {
name: rib_ident.name,
param_kind: None,
});
}
return Res::Err;
}
RibKind::InlineAsmSym => {
if let Some(span) = finalize {
self.report_error(span, InvalidAsmSym);
}
return Res::Err;
}
}
}
if let Some((span, res_err)) = res_err {
self.report_error(span, res_err);
return Res::Err;
}
}
Res::Def(DefKind::TyParam, _) | Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } => {
for rib in ribs {
let (has_generic_params, def_kind) = match rib.kind {
RibKind::Normal
| RibKind::FnOrCoroutine
| RibKind::Module(..)
| RibKind::MacroDefinition(..)
| RibKind::InlineAsmSym
| RibKind::AssocItem
| RibKind::ForwardGenericParamBan => {
// Nothing to do. Continue.
continue;
}
RibKind::ConstantItem(trivial, _) => {
if let ConstantHasGenerics::No(cause) = trivial {
// HACK(min_const_generics): If we encounter `Self` in an anonymous
// constant we can't easily tell if it's generic at this stage, so
// we instead remember this and then enforce the self type to be
// concrete later on.
if let Res::SelfTyAlias {
alias_to: def,
forbid_generic: _,
is_trait_impl,
} = res
{
res = Res::SelfTyAlias {
alias_to: def,
forbid_generic: true,
is_trait_impl,
}
} else {
if let Some(span) = finalize {
let error = match cause {
NoConstantGenericsReason::IsEnumDiscriminant => {
ResolutionError::ParamInEnumDiscriminant {
name: rib_ident.name,
param_kind: ParamKindInEnumDiscriminant::Type,
}
}
NoConstantGenericsReason::NonTrivialConstArg => {
ResolutionError::ParamInNonTrivialAnonConst {
name: rib_ident.name,
param_kind:
ParamKindInNonTrivialAnonConst::Type,
}
}
};
let _: ErrorGuaranteed = self.report_error(span, error);
}
return Res::Err;
}
}
continue;
}
// This was an attempt to use a type parameter outside its scope.
RibKind::Item(has_generic_params, def_kind) => {
(has_generic_params, def_kind)
}
RibKind::ConstParamTy => {
if let Some(span) = finalize {
self.report_error(span, ResolutionError::ParamInTyOfConstParam {
name: rib_ident.name,
param_kind: Some(errors::ParamKindInTyOfConstParam::Type),
});
}
return Res::Err;
}
};
if let Some(span) = finalize {
self.report_error(
span,
ResolutionError::GenericParamsFromOuterItem(
res,
has_generic_params,
def_kind,
),
);
}
return Res::Err;
}
}
Res::Def(DefKind::ConstParam, _) => {
for rib in ribs {
let (has_generic_params, def_kind) = match rib.kind {
RibKind::Normal
| RibKind::FnOrCoroutine
| RibKind::Module(..)
| RibKind::MacroDefinition(..)
| RibKind::InlineAsmSym
| RibKind::AssocItem
| RibKind::ForwardGenericParamBan => continue,
RibKind::ConstantItem(trivial, _) => {
if let ConstantHasGenerics::No(cause) = trivial {
if let Some(span) = finalize {
let error = match cause {
NoConstantGenericsReason::IsEnumDiscriminant => {
ResolutionError::ParamInEnumDiscriminant {
name: rib_ident.name,
param_kind: ParamKindInEnumDiscriminant::Const,
}
}
NoConstantGenericsReason::NonTrivialConstArg => {
ResolutionError::ParamInNonTrivialAnonConst {
name: rib_ident.name,
param_kind: ParamKindInNonTrivialAnonConst::Const {
name: rib_ident.name,
},
}
}
};
self.report_error(span, error);
}
return Res::Err;
}
continue;
}
RibKind::Item(has_generic_params, def_kind) => {
(has_generic_params, def_kind)
}
RibKind::ConstParamTy => {
if let Some(span) = finalize {
self.report_error(span, ResolutionError::ParamInTyOfConstParam {
name: rib_ident.name,
param_kind: Some(errors::ParamKindInTyOfConstParam::Const),
});
}
return Res::Err;
}
};
// This was an attempt to use a const parameter outside its scope.
if let Some(span) = finalize {
self.report_error(
span,
ResolutionError::GenericParamsFromOuterItem(
res,
has_generic_params,
def_kind,
),
);
}
return Res::Err;
}
}
_ => {}
}
res
}
#[instrument(level = "debug", skip(self))]
pub(crate) fn maybe_resolve_path(
&mut self,
path: &[Segment],
opt_ns: Option<Namespace>, // `None` indicates a module path in import
parent_scope: &ParentScope<'ra>,
ignore_import: Option<Import<'ra>>,
) -> PathResult<'ra> {
self.resolve_path_with_ribs(path, opt_ns, parent_scope, None, None, None, ignore_import)
}
#[instrument(level = "debug", skip(self))]
pub(crate) fn resolve_path(
&mut self,
path: &[Segment],
opt_ns: Option<Namespace>, // `None` indicates a module path in import
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> PathResult<'ra> {
self.resolve_path_with_ribs(
path,
opt_ns,
parent_scope,
finalize,
None,
ignore_binding,
ignore_import,
)
}
pub(crate) fn resolve_path_with_ribs(
&mut self,
path: &[Segment],
opt_ns: Option<Namespace>, // `None` indicates a module path in import
parent_scope: &ParentScope<'ra>,
finalize: Option<Finalize>,
ribs: Option<&PerNS<Vec<Rib<'ra>>>>,
ignore_binding: Option<NameBinding<'ra>>,
ignore_import: Option<Import<'ra>>,
) -> PathResult<'ra> {
let mut module = None;
let mut allow_super = true;
let mut second_binding = None;
// We'll provide more context to the privacy errors later, up to `len`.
let privacy_errors_len = self.privacy_errors.len();
for (segment_idx, &Segment { ident, id, .. }) in path.iter().enumerate() {
debug!("resolve_path ident {} {:?} {:?}", segment_idx, ident, id);
let record_segment_res = |this: &mut Self, res| {
if finalize.is_some() {
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 = segment_idx + 1 == path.len();
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().normalize_to_macros_2_0();
let self_module = match segment_idx {
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;
}
}
return PathResult::failed(ident, false, finalize.is_some(), module, || {
("there are too many leading `super` keywords".to_string(), None)
});
}
if segment_idx == 0 {
if name == kw::SelfLower {
let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0();
module = Some(ModuleOrUniformRoot::Module(
self.resolve_self(&mut ctxt, parent_scope.module),
));
continue;
}
if name == kw::PathRoot && ident.span.at_least_rust_2018() {
module = Some(ModuleOrUniformRoot::ExternPrelude);
continue;
}
if name == kw::PathRoot
&& ident.span.is_rust_2015()
&& self.tcx.sess.at_least_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() && segment_idx != 0 {
return PathResult::failed(ident, false, finalize.is_some(), module, || {
let name_str = if name == kw::PathRoot {
"crate root".to_string()
} else {
format!("`{name}`")
};
let label = if segment_idx == 1 && path[0].ident.name == kw::PathRoot {
format!("global paths cannot start with {name_str}")
} else {
format!("{name_str} in paths can only be used in start position")
};
(label, None)
});
}
let binding = if let Some(module) = module {
self.resolve_ident_in_module(
module,
ident,
ns,
parent_scope,
finalize,
ignore_binding,
ignore_import,
)
} else if let Some(ribs) = ribs
&& let Some(TypeNS | ValueNS) = opt_ns
{
assert!(ignore_import.is_none());
match self.resolve_ident_in_lexical_scope(
ident,
ns,
parent_scope,
finalize,
&ribs[ns],
ignore_binding,
) {
// 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)) => {
record_segment_res(self, res);
return PathResult::NonModule(PartialRes::with_unresolved_segments(
res,
path.len() - 1,
));
}
_ => Err(Determinacy::determined(finalize.is_some())),
}
} else {
self.early_resolve_ident_in_lexical_scope(
ident,
ScopeSet::All(ns),
parent_scope,
finalize,
finalize.is_some(),
ignore_binding,
ignore_import,
)
};
match binding {
Ok(binding) => {
if segment_idx == 1 {
second_binding = Some(binding);
}
let res = binding.res();
// Mark every privacy error in this path with the res to the last element. This allows us
// to detect the item the user cares about and either find an alternative import, or tell
// the user it is not accessible.
for error in &mut self.privacy_errors[privacy_errors_len..] {
error.outermost_res = Some((res, ident));
}
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 && !is_last && opt_ns.is_some() {
if binding.is_import() {
self.dcx().emit_err(errors::ToolModuleImported {
span: ident.span,
import: binding.span,
});
}
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(finalize, path, second_binding);
record_segment_res(self, res);
return PathResult::NonModule(PartialRes::with_unresolved_segments(
res,
path.len() - segment_idx - 1,
));
} else {
return PathResult::failed(
ident,
is_last,
finalize.is_some(),
module,
|| {
let label = format!(
"`{ident}` is {} {}, not a module",
res.article(),
res.descr()
);
(label, None)
},
);
}
}
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() - segment_idx,
));
}
}
return PathResult::failed(ident, is_last, finalize.is_some(), module, || {
self.report_path_resolution_error(
path,
opt_ns,
parent_scope,
ribs,
ignore_binding,
ignore_import,
module,
segment_idx,
ident,
)
});
}
}
}
self.lint_if_path_starts_with_module(finalize, path, second_binding);
PathResult::Module(match module {
Some(module) => module,
None if path.is_empty() => ModuleOrUniformRoot::CurrentScope,
_ => bug!("resolve_path: non-empty path `{:?}` has no module", path),
})
}
}