use rustc_hir::def::Namespace::{self, *};
use rustc_hir::def::{self, CtorKind, DefKind, LifetimeRes, PartialRes, PerNS};
use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
-use rustc_hir::{PrimTy, TraitCandidate};
+use rustc_hir::{BindingAnnotation, PrimTy, TraitCandidate};
use rustc_middle::middle::resolve_lifetime::Set1;
use rustc_middle::ty::DefIdTree;
use rustc_middle::{bug, span_bug};
use smallvec::{smallvec, SmallVec};
use rustc_span::source_map::{respan, Spanned};
+use std::assert_matches::debug_assert_matches;
use std::collections::{hash_map::Entry, BTreeSet};
use std::mem::{replace, take};
-use tracing::debug;
mod diagnostics;
pub(crate) mod lifetimes;
#[derive(Copy, Clone, Debug)]
struct BindingInfo {
span: Span,
- binding_mode: BindingMode,
+ annotation: BindingAnnotation,
}
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
}
/// Does this the item (from the item rib scope) allow generic parameters?
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug)]
pub(crate) enum HasGenericParams {
+ Yes(Span),
+ No,
+}
+
+/// May this constant have generics?
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub(crate) enum ConstantHasGenerics {
Yes,
No,
}
-impl HasGenericParams {
+impl ConstantHasGenerics {
fn force_yes_if(self, b: bool) -> Self {
if b { Self::Yes } else { self }
}
/// We passed through a closure. Disallow labels.
ClosureOrAsyncRibKind,
- /// 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(HasGenericParams),
///
/// The item may reference generic parameters in trivial constant expressions.
/// All other constants aren't allowed to use generic params at all.
- ConstantItemRibKind(HasGenericParams, Option<(Ident, ConstantItemKind)>),
+ ConstantItemRibKind(ConstantHasGenerics, Option<(Ident, ConstantItemKind)>),
/// We passed through a module.
ModuleRibKind(Module<'a>),
match self {
NormalRibKind
| ClosureOrAsyncRibKind
- | FnItemRibKind
| ConstantItemRibKind(..)
| ModuleRibKind(_)
| MacroDefinition(_)
AssocItemRibKind
| ClosureOrAsyncRibKind
- | FnItemRibKind
| ItemRibKind(..)
| ConstantItemRibKind(..)
| ModuleRibKind(..)
/// They will be used to determine the correct lifetime for the fn return type.
/// The `LifetimeElisionCandidate` is used for diagnostics, to suggest introducing named
/// lifetimes.
- lifetime_elision_candidates: Option<FxIndexMap<LifetimeRes, LifetimeElisionCandidate>>,
+ lifetime_elision_candidates: Option<Vec<(LifetimeRes, LifetimeElisionCandidate)>>,
/// The trait that the current context can refer to.
current_trait_ref: Option<(Module<'a>, TraitRef)>,
// Elided lifetime in reference: we resolve as if there was some lifetime `'_` with
// NodeId `ty.id`.
// This span will be used in case of elision failure.
- let span = self.r.session.source_map().next_point(ty.span.shrink_to_lo());
+ let span = self.r.session.source_map().start_point(ty.span);
self.resolve_elided_lifetime(ty.id, span);
visit::walk_ty(self, ty);
}
self.diagnostic_metadata.current_trait_object = prev;
self.diagnostic_metadata.current_type_path = prev_ty;
}
- fn visit_poly_trait_ref(&mut self, tref: &'ast PolyTraitRef, _: &'ast TraitBoundModifier) {
+ fn visit_poly_trait_ref(&mut self, tref: &'ast PolyTraitRef) {
let span = tref.span.shrink_to_lo().to(tref.trait_ref.path.span.shrink_to_lo());
self.with_generic_param_rib(
&tref.bound_generic_params,
self.with_lifetime_rib(LifetimeRibKind::Item, |this| {
this.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: foreign_item.id,
kind: LifetimeBinderKind::Item,
self.with_lifetime_rib(LifetimeRibKind::Item, |this| {
this.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: foreign_item.id,
kind: LifetimeBinderKind::Function,
}
}
fn visit_fn(&mut self, fn_kind: FnKind<'ast>, sp: Span, fn_id: NodeId) {
- let rib_kind = match fn_kind {
+ let previous_value = self.diagnostic_metadata.current_function;
+ match fn_kind {
// Bail if the function is foreign, and thus cannot validly have
// a body, or if there's no body for some other reason.
FnKind::Fn(FnCtxt::Foreign, _, sig, _, generics, _)
);
return;
}
- FnKind::Fn(FnCtxt::Free, ..) => FnItemRibKind,
- FnKind::Fn(FnCtxt::Assoc(_), ..) => NormalRibKind,
- FnKind::Closure(..) => ClosureOrAsyncRibKind,
+ FnKind::Fn(..) => {
+ self.diagnostic_metadata.current_function = Some((fn_kind, sp));
+ }
+ // Do not update `current_function` for closures: it suggests `self` parameters.
+ FnKind::Closure(..) => {}
};
- let previous_value = self.diagnostic_metadata.current_function;
- if matches!(fn_kind, FnKind::Fn(..)) {
- self.diagnostic_metadata.current_function = Some((fn_kind, sp));
- }
debug!("(resolving function) entering function");
// Create a value rib for the function.
- self.with_rib(ValueNS, rib_kind, |this| {
+ self.with_rib(ValueNS, ClosureOrAsyncRibKind, |this| {
// Create a label rib for the function.
- this.with_label_rib(FnItemRibKind, |this| {
+ this.with_label_rib(ClosureOrAsyncRibKind, |this| {
match fn_kind {
FnKind::Fn(_, _, sig, _, generics, body) => {
this.visit_generics(generics);
// We include all lifetime parameters, either named or "Fresh".
// The order of those parameters does not matter, as long as it is
// deterministic.
- if let Some(async_node_id) = async_node_id {
+ if let Some((async_node_id, _)) = async_node_id {
let mut extra_lifetime_params = this
.r
.extra_lifetime_params_map
// non-trivial constants this is doesn't matter.
self.with_constant_rib(
IsRepeatExpr::No,
- HasGenericParams::Yes,
+ ConstantHasGenerics::Yes,
None,
|this| {
this.smart_resolve_path(
if let Some(ref gen_args) = constraint.gen_args {
// Forbid anonymous lifetimes in GAT parameters until proper semantics are decided.
self.with_lifetime_rib(LifetimeRibKind::AnonymousReportError, |this| {
- this.visit_generic_args(gen_args.span(), gen_args)
+ this.visit_generic_args(gen_args)
});
}
match constraint.kind {
}
}
- fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
+ fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) {
if let Some(ref args) = path_segment.args {
match &**args {
- GenericArgs::AngleBracketed(..) => visit::walk_generic_args(self, path_span, args),
+ GenericArgs::AngleBracketed(..) => visit::walk_generic_args(self, args),
GenericArgs::Parenthesized(p_args) => {
// Probe the lifetime ribs to know how to behave.
for rib in self.lifetime_ribs.iter().rev() {
// We have nowhere to introduce generics. Code is malformed,
// so use regular lifetime resolution to avoid spurious errors.
LifetimeRibKind::Item | LifetimeRibKind::Generics { .. } => {
- visit::walk_generic_args(self, path_span, args);
+ visit::walk_generic_args(self, args);
break;
}
LifetimeRibKind::AnonymousCreateParameter { .. }
})
}
- #[tracing::instrument(level = "debug", skip(self, work))]
+ #[instrument(level = "debug", skip(self, work))]
fn with_lifetime_rib<T>(
&mut self,
kind: LifetimeRibKind,
ret
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn resolve_lifetime(&mut self, lifetime: &'ast Lifetime, use_ctxt: visit::LifetimeCtxt) {
let ident = lifetime.ident;
self.record_lifetime_res(lifetime.id, LifetimeRes::Error, LifetimeElisionCandidate::Named);
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn resolve_anonymous_lifetime(&mut self, lifetime: &Lifetime, elided: bool) {
debug_assert_eq!(lifetime.ident.name, kw::UnderscoreLifetime);
self.report_missing_lifetime_specifiers(vec![missing_lifetime], None);
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn resolve_elided_lifetime(&mut self, anchor_id: NodeId, span: Span) {
let id = self.r.next_node_id();
let lt = Lifetime { id, ident: Ident::new(kw::UnderscoreLifetime, span) };
self.resolve_anonymous_lifetime(<, true);
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn create_fresh_lifetime(&mut self, id: NodeId, ident: Ident, binder: NodeId) -> LifetimeRes {
debug_assert_eq!(ident.name, kw::UnderscoreLifetime);
debug!(?ident.span);
res
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn resolve_elided_lifetimes_in_path(
&mut self,
path_id: NodeId,
}
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn record_lifetime_res(
&mut self,
id: NodeId,
match res {
LifetimeRes::Param { .. } | LifetimeRes::Fresh { .. } | LifetimeRes::Static => {
if let Some(ref mut candidates) = self.lifetime_elision_candidates {
- candidates.insert(res, candidate);
+ candidates.push((res, candidate));
}
}
LifetimeRes::Infer | LifetimeRes::Error | LifetimeRes::ElidedAnchor { .. } => {}
}
}
- #[tracing::instrument(level = "debug", skip(self))]
+ #[instrument(level = "debug", skip(self))]
fn record_lifetime_param(&mut self, id: NodeId, res: LifetimeRes) {
if let Some(prev_res) = self.r.lifetimes_res_map.insert(id, res) {
panic!(
}
/// Perform resolution of a function signature, accounting for lifetime elision.
- #[tracing::instrument(level = "debug", skip(self, inputs))]
+ #[instrument(level = "debug", skip(self, inputs))]
fn resolve_fn_signature(
&mut self,
fn_id: NodeId,
has_self: bool,
inputs: impl Iterator<Item = (Option<&'ast Pat>, &'ast Ty)>,
) -> Result<LifetimeRes, (Vec<MissingLifetime>, Vec<ElisionFnParameter>)> {
- let outer_candidates =
- replace(&mut self.lifetime_elision_candidates, Some(Default::default()));
+ enum Elision {
+ /// We have not found any candidate.
+ None,
+ /// We have a candidate bound to `self`.
+ Self_(LifetimeRes),
+ /// We have a candidate bound to a parameter.
+ Param(LifetimeRes),
+ /// We failed elision.
+ Err,
+ }
+
+ // Save elision state to reinstate it later.
+ let outer_candidates = self.lifetime_elision_candidates.take();
- let mut elision_lifetime = None;
- let mut lifetime_count = 0;
+ // Result of elision.
+ let mut elision_lifetime = Elision::None;
+ // Information for diagnostics.
let mut parameter_info = Vec::new();
+ let mut all_candidates = Vec::new();
let mut bindings = smallvec![(PatBoundCtx::Product, Default::default())];
for (index, (pat, ty)) in inputs.enumerate() {
if let Some(pat) = pat {
self.resolve_pattern(pat, PatternSource::FnParam, &mut bindings);
}
+
+ // Record elision candidates only for this parameter.
+ debug_assert_matches!(self.lifetime_elision_candidates, None);
+ self.lifetime_elision_candidates = Some(Default::default());
self.visit_ty(ty);
+ let local_candidates = self.lifetime_elision_candidates.take();
- if let Some(ref candidates) = self.lifetime_elision_candidates {
- let new_count = candidates.len();
- let local_count = new_count - lifetime_count;
- if local_count != 0 {
+ if let Some(candidates) = local_candidates {
+ let distinct: FxHashSet<_> = candidates.iter().map(|(res, _)| *res).collect();
+ let lifetime_count = distinct.len();
+ if lifetime_count != 0 {
parameter_info.push(ElisionFnParameter {
index,
ident: if let Some(pat) = pat && let PatKind::Ident(_, ident, _) = pat.kind {
} else {
None
},
- lifetime_count: local_count,
+ lifetime_count,
span: ty.span,
});
+ all_candidates.extend(candidates.into_iter().filter_map(|(_, candidate)| {
+ match candidate {
+ LifetimeElisionCandidate::Ignore | LifetimeElisionCandidate::Named => {
+ None
+ }
+ LifetimeElisionCandidate::Missing(missing) => Some(missing),
+ }
+ }));
+ }
+ let mut distinct_iter = distinct.into_iter();
+ if let Some(res) = distinct_iter.next() {
+ match elision_lifetime {
+ // We are the first parameter to bind lifetimes.
+ Elision::None => {
+ if distinct_iter.next().is_none() {
+ // We have a single lifetime => success.
+ elision_lifetime = Elision::Param(res)
+ } else {
+ // We have have multiple lifetimes => error.
+ elision_lifetime = Elision::Err;
+ }
+ }
+ // We have 2 parameters that bind lifetimes => error.
+ Elision::Param(_) => elision_lifetime = Elision::Err,
+ // `self` elision takes precedence over everything else.
+ Elision::Self_(_) | Elision::Err => {}
+ }
}
- lifetime_count = new_count;
}
// Handle `self` specially.
if index == 0 && has_self {
let self_lifetime = self.find_lifetime_for_self(ty);
if let Set1::One(lifetime) = self_lifetime {
- elision_lifetime = Some(lifetime);
- self.lifetime_elision_candidates = None;
+ // We found `self` elision.
+ elision_lifetime = Elision::Self_(lifetime);
} else {
- self.lifetime_elision_candidates = Some(Default::default());
- lifetime_count = 0;
+ // We do not have `self` elision: disregard the `Elision::Param` that we may
+ // have found.
+ elision_lifetime = Elision::None;
}
}
debug!("(resolving function / closure) recorded parameter");
}
- let all_candidates = replace(&mut self.lifetime_elision_candidates, outer_candidates);
- debug!(?all_candidates);
+ // Reinstate elision state.
+ debug_assert_matches!(self.lifetime_elision_candidates, None);
+ self.lifetime_elision_candidates = outer_candidates;
- if let Some(res) = elision_lifetime {
+ if let Elision::Param(res) | Elision::Self_(res) = elision_lifetime {
return Ok(res);
}
- // We do not have a `self` candidate, look at the full list.
- let all_candidates = all_candidates.unwrap();
- if all_candidates.len() == 1 {
- Ok(*all_candidates.first().unwrap().0)
- } else {
- let all_candidates = all_candidates
- .into_iter()
- .filter_map(|(_, candidate)| match candidate {
- LifetimeElisionCandidate::Ignore | LifetimeElisionCandidate::Named => None,
- LifetimeElisionCandidate::Missing(missing) => Some(missing),
- })
- .collect();
- Err((all_candidates, parameter_info))
- }
+ // We do not have a candidate.
+ Err((all_candidates, parameter_info))
}
/// List all the lifetimes that appear in the provided type.
self.with_current_self_item(item, |this| {
this.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: item.id,
kind: LifetimeBinderKind::Item,
ItemKind::TyAlias(box TyAlias { ref generics, .. }) => {
self.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: item.id,
kind: LifetimeBinderKind::Item,
ItemKind::Fn(box Fn { ref generics, .. }) => {
self.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: item.id,
kind: LifetimeBinderKind::Function,
// Create a new rib for the trait-wide type parameters.
self.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: item.id,
kind: LifetimeBinderKind::Item,
// Create a new rib for the trait-wide type parameters.
self.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
binder: item.id,
kind: LifetimeBinderKind::Item,
// so it doesn't matter whether this is a trivial constant.
this.with_constant_rib(
IsRepeatExpr::No,
- HasGenericParams::Yes,
+ ConstantHasGenerics::Yes,
Some((item.ident, constant_item_kind)),
|this| this.visit_expr(expr),
);
// Do not account for the parameters we just bound for function lifetime elision.
if let Some(ref mut candidates) = self.lifetime_elision_candidates {
for (_, res) in function_lifetime_rib.bindings.values() {
- candidates.remove(res);
+ candidates.retain(|(r, _)| r != res);
}
}
fn with_constant_rib(
&mut self,
is_repeat: IsRepeatExpr,
- may_use_generics: HasGenericParams,
+ may_use_generics: ConstantHasGenerics,
item: Option<(Ident, ConstantItemKind)>,
f: impl FnOnce(&mut Self),
) {
|this| {
this.with_constant_rib(
IsRepeatExpr::No,
- HasGenericParams::Yes,
+ ConstantHasGenerics::Yes,
None,
|this| this.visit_expr(expr),
)
// If applicable, create a rib for the type parameters.
self.with_generic_param_rib(
&generics.params,
- ItemRibKind(HasGenericParams::Yes),
+ ItemRibKind(HasGenericParams::Yes(generics.span)),
LifetimeRibKind::Generics {
span: generics.span,
binder: item_id,
self.with_lifetime_rib(LifetimeRibKind::Elided(LifetimeRes::Infer), |this| {
this.with_constant_rib(
IsRepeatExpr::No,
- HasGenericParams::Yes,
+ ConstantHasGenerics::Yes,
None,
|this| this.visit_expr(expr),
)
pat.walk(&mut |pat| {
match pat.kind {
- PatKind::Ident(binding_mode, ident, ref sub_pat)
+ PatKind::Ident(annotation, ident, ref sub_pat)
if sub_pat.is_some() || self.is_base_res_local(pat.id) =>
{
- binding_map.insert(ident, BindingInfo { span: ident.span, binding_mode });
+ binding_map.insert(ident, BindingInfo { span: ident.span, annotation });
}
PatKind::Or(ref ps) => {
// Check the consistency of this or-pattern and
binding_error.target.insert(pat_outer.span);
}
Some(binding_outer) => {
- if binding_outer.binding_mode != binding_inner.binding_mode {
+ if binding_outer.annotation != binding_inner.annotation {
// The binding modes in the outer and inner bindings differ.
inconsistent_vars
.entry(name)
fn try_resolve_as_non_binding(
&mut self,
pat_src: PatternSource,
- bm: BindingMode,
+ ann: BindingAnnotation,
ident: Ident,
has_sub: bool,
) -> Option<Res> {
// An immutable (no `mut`) by-value (no `ref`) binding pattern without
// a sub pattern (no `@ $pat`) is syntactically ambiguous as it could
// also be interpreted as a path to e.g. a constant, variant, etc.
- let is_syntactic_ambiguity = !has_sub && bm == BindingMode::ByValue(Mutability::Not);
+ let is_syntactic_ambiguity = !has_sub && ann == BindingAnnotation::NONE;
let ls_binding = self.maybe_resolve_ident_in_lexical_scope(ident, ValueNS)?;
let (res, binding) = match ls_binding {
source: PathSource<'ast>,
finalize: Finalize,
) -> PartialRes {
- tracing::debug!(
+ debug!(
"smart_resolve_path_fragment(qself={:?}, path={:?}, finalize={:?})",
- qself,
- path,
- finalize,
+ qself, path, finalize,
);
let ns = source.namespace();
self.with_constant_rib(
is_repeat,
if constant.value.is_potential_trivial_const_param() {
- HasGenericParams::Yes
+ ConstantHasGenerics::Yes
} else {
- HasGenericParams::No
+ ConstantHasGenerics::No
},
None,
|this| visit::walk_anon_const(this, constant),
fn resolve_inline_const(&mut self, constant: &'ast AnonConst) {
debug!("resolve_anon_const {constant:?}");
- self.with_constant_rib(IsRepeatExpr::No, HasGenericParams::Yes, None, |this| {
- visit::walk_anon_const(this, constant);
+ self.with_constant_rib(IsRepeatExpr::No, ConstantHasGenerics::Yes, None, |this| {
+ visit::walk_anon_const(this, constant)
});
}
for argument in arguments {
self.resolve_expr(argument, None);
}
- self.visit_path_segment(expr.span, segment);
+ self.visit_path_segment(segment);
}
ExprKind::Call(ref callee, ref arguments) => {
self.with_constant_rib(
IsRepeatExpr::No,
if argument.is_potential_trivial_const_param() {
- HasGenericParams::Yes
+ ConstantHasGenerics::Yes
} else {
- HasGenericParams::No
+ ConstantHasGenerics::No
},
None,
|this| {
projects / rustc.git / blobdiff