Skip to content

Remove Scope::Elision from bound-vars resolution. #113950

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 22, 2023
Merged

Remove Scope::Elision from bound-vars resolution. #113950

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
59 changes: 21 additions & 38 deletions compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -137,12 +137,6 @@ enum Scope<'a> {
s: ScopeRef<'a>,
},

/// A scope which either determines unspecified lifetimes or errors
/// on them (e.g., due to ambiguity).
Elision {
s: ScopeRef<'a>,
},

/// Use a specific lifetime (if `Some`) or leave it unset (to be
/// inferred in a function body or potentially error outside one),
/// for the default choice of lifetime in a trait object type.
Expand Down Expand Up @@ -211,7 +205,6 @@ impl<'a> fmt::Debug for TruncatedScopeDebug<'a> {
Scope::Body { id, s: _ } => {
f.debug_struct("Body").field("id", id).field("s", &"..").finish()
}
Scope::Elision { s: _ } => f.debug_struct("Elision").field("s", &"..").finish(),
Scope::ObjectLifetimeDefault { lifetime, s: _ } => f
.debug_struct("ObjectLifetimeDefault")
.field("lifetime", lifetime)
Expand Down Expand Up @@ -325,9 +318,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
break (vec![], BinderScopeType::Normal);
}

Scope::Elision { s, .. }
| Scope::ObjectLifetimeDefault { s, .. }
| Scope::AnonConstBoundary { s } => {
Scope::ObjectLifetimeDefault { s, .. } | Scope::AnonConstBoundary { s } => {
scope = s;
}

Expand Down Expand Up @@ -526,16 +517,12 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
| hir::ItemKind::Macro(..)
| hir::ItemKind::Mod(..)
| hir::ItemKind::ForeignMod { .. }
| hir::ItemKind::Static(..)
| hir::ItemKind::Const(..)
| hir::ItemKind::GlobalAsm(..) => {
// These sorts of items have no lifetime parameters at all.
intravisit::walk_item(self, item);
}
hir::ItemKind::Static(..) | hir::ItemKind::Const(..) => {
// No lifetime parameters, but implied 'static.
self.with(Scope::Elision { s: self.scope }, |this| {
intravisit::walk_item(this, item)
});
}
hir::ItemKind::OpaqueTy(hir::OpaqueTy {
origin: hir::OpaqueTyOrigin::TyAlias { .. },
..
Expand Down Expand Up @@ -727,12 +714,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
// Elided lifetimes are not allowed in non-return
// position impl Trait
let scope = Scope::TraitRefBoundary { s: self.scope };
self.with(scope, |this| {
let scope = Scope::Elision { s: this.scope };
this.with(scope, |this| {
intravisit::walk_item(this, opaque_ty);
})
});
self.with(scope, |this| intravisit::walk_item(this, opaque_ty));
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

For TAIT, a trait object necessarily inside generic arguments, that have their own ObjectLifetimeDefault rib.


return;
}
Expand Down Expand Up @@ -1293,8 +1275,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
scope = s;
}

Scope::Elision { s, .. }
| Scope::ObjectLifetimeDefault { s, .. }
Scope::ObjectLifetimeDefault { s, .. }
| Scope::Supertrait { s, .. }
| Scope::TraitRefBoundary { s, .. }
| Scope::AnonConstBoundary { s } => {
Expand Down Expand Up @@ -1357,7 +1338,6 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
Scope::Root { .. } => break,
Scope::Binder { s, .. }
| Scope::Body { s, .. }
| Scope::Elision { s, .. }
| Scope::ObjectLifetimeDefault { s, .. }
| Scope::Supertrait { s, .. }
| Scope::TraitRefBoundary { s, .. }
Expand Down Expand Up @@ -1409,8 +1389,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
scope = s;
}

Scope::Elision { s, .. }
| Scope::ObjectLifetimeDefault { s, .. }
Scope::ObjectLifetimeDefault { s, .. }
| Scope::Supertrait { s, .. }
| Scope::TraitRefBoundary { s, .. } => {
scope = s;
Expand Down Expand Up @@ -1483,7 +1462,6 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
Scope::Root { .. } => break,
Scope::Binder { s, .. }
| Scope::Body { s, .. }
| Scope::Elision { s, .. }
| Scope::ObjectLifetimeDefault { s, .. }
| Scope::Supertrait { s, .. }
| Scope::TraitRefBoundary { s, .. }
Expand Down Expand Up @@ -1564,7 +1542,6 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
Scope::Body { .. } => break true,

Scope::Binder { s, .. }
| Scope::Elision { s, .. }
| Scope::ObjectLifetimeDefault { s, .. }
| Scope::Supertrait { s, .. }
| Scope::TraitRefBoundary { s, .. }
Expand Down Expand Up @@ -1832,14 +1809,20 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
output: Option<&'tcx hir::Ty<'tcx>>,
in_closure: bool,
) {
self.with(Scope::Elision { s: self.scope }, |this| {
for input in inputs {
this.visit_ty(input);
}
if !in_closure && let Some(output) = output {
this.visit_ty(output);
}
});
self.with(
Scope::ObjectLifetimeDefault {
lifetime: Some(ResolvedArg::StaticLifetime),
s: self.scope,
},
|this| {
for input in inputs {
this.visit_ty(input);
}
if !in_closure && let Some(output) = output {
this.visit_ty(output);
}
},
);
if in_closure && let Some(output) = output {
self.visit_ty(output);
}
Expand All @@ -1859,7 +1842,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
scope = s;
}

Scope::Root { .. } | Scope::Elision { .. } => break ResolvedArg::StaticLifetime,
Scope::Root { .. } => break ResolvedArg::StaticLifetime,

Scope::Body { .. } | Scope::ObjectLifetimeDefault { lifetime: None, .. } => return,

Expand Down