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cjgillotcjgillot
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Create a specific ObjectLifetimeDefault enum.
1 parent cac02f4 commit 5a0aaaf

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5 files changed

+56
-83
lines changed

5 files changed

+56
-83
lines changed

‎compiler/rustc_middle/src/middle/resolve_lifetime.rs‎

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -36,7 +36,13 @@ impl<T: PartialEq> Set1<T> {
3636
}
3737
}
3838

39-
pub type ObjectLifetimeDefault = Set1<Region>;
39+
#[derive(Copy, Clone, Debug, HashStable, Encodable, Decodable)]
40+
pub enum ObjectLifetimeDefault {
41+
Empty,
42+
Static,
43+
Ambiguous,
44+
Param(DefId),
45+
}
4046

4147
/// Maps the id of each lifetime reference to the lifetime decl
4248
/// that it corresponds to.

‎compiler/rustc_middle/src/query/mod.rs‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1591,7 +1591,7 @@ rustc_queries! {
15911591
/// for each parameter if a trait object were to be passed for that parameter.
15921592
/// For example, for `struct Foo<'a, T, U>`, this would be `['static, 'static]`.
15931593
/// For `struct Foo<'a, T: 'a, U>`, this would instead be `['a, 'static]`.
1594-
query object_lifetime_defaults(_: DefId) -> Option<&'tcx [ObjectLifetimeDefault]> {
1594+
query object_lifetime_defaults(_: LocalDefId) -> Option<&'tcx [ObjectLifetimeDefault]> {
15951595
desc { "looking up lifetime defaults for a region on an item" }
15961596
}
15971597
/// Fetch the lifetimes for all the trait objects in an item-like.

‎compiler/rustc_typeck/src/astconv/mod.rs‎

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -269,9 +269,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
269269
// (*) -- not late-bound, won't change
270270
}
271271
};
272-
273272
debug!("ast_region_to_region(lifetime={:?}) yields {:?}", lifetime, r);
274-
275273
r
276274
}
277275

‎compiler/rustc_typeck/src/collect.rs‎

Lines changed: 5 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -34,6 +34,7 @@ use rustc_hir::weak_lang_items;
3434
use rustc_hir::{GenericParamKind, HirId, Node};
3535
use rustc_middle::hir::nested_filter;
3636
use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
37+
use rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault;
3738
use rustc_middle::mir::mono::Linkage;
3839
use rustc_middle::ty::query::Providers;
3940
use rustc_middle::ty::subst::InternalSubsts;
@@ -1615,7 +1616,7 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
16151616
pure_wrt_drop: false,
16161617
kind: ty::GenericParamDefKind::Type {
16171618
has_default: false,
1618-
object_lifetime_default: rl::Set1::Empty,
1619+
object_lifetime_default: ObjectLifetimeDefault::Empty,
16191620
synthetic: false,
16201621
},
16211622
});
@@ -1689,7 +1690,7 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
16891690
has_default: default.is_some(),
16901691
object_lifetime_default: object_lifetime_defaults
16911692
.as_ref()
1692-
.map_or(rl::Set1::Empty, |o| o[i]),
1693+
.map_or(ObjectLifetimeDefault::Empty, |o| o[i]),
16931694
synthetic,
16941695
};
16951696

@@ -1741,7 +1742,7 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
17411742
pure_wrt_drop: false,
17421743
kind: ty::GenericParamDefKind::Type {
17431744
has_default: false,
1744-
object_lifetime_default: rl::Set1::Empty,
1745+
object_lifetime_default: ObjectLifetimeDefault::Empty,
17451746
synthetic: false,
17461747
},
17471748
}));
@@ -1758,7 +1759,7 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics {
17581759
pure_wrt_drop: false,
17591760
kind: ty::GenericParamDefKind::Type {
17601761
has_default: false,
1761-
object_lifetime_default: rl::Set1::Empty,
1762+
object_lifetime_default: ObjectLifetimeDefault::Empty,
17621763
synthetic: false,
17631764
},
17641765
});

‎compiler/rustc_typeck/src/collect/object_lifetime_defaults.rs‎

Lines changed: 43 additions & 75 deletions
Original file line numberDiff line numberDiff line change
@@ -17,30 +17,9 @@ use tracing::debug;
1717

1818
pub(super) fn object_lifetime_defaults(
1919
tcx: TyCtxt<'_>,
20-
def_id: DefId,
20+
def_id: LocalDefId,
2121
) -> Option<&[ObjectLifetimeDefault]> {
22-
if let Some(def_id) = def_id.as_local() {
23-
match tcx.hir().get_by_def_id(def_id) {
24-
Node::Item(item) => compute_object_lifetime_defaults(tcx, item),
25-
_ => None,
26-
}
27-
} else {
28-
Some(tcx.arena.alloc_from_iter(tcx.generics_of(def_id).params.iter().filter_map(|param| {
29-
match param.kind {
30-
GenericParamDefKind::Type { object_lifetime_default, .. } => {
31-
Some(object_lifetime_default)
32-
}
33-
GenericParamDefKind::Const { .. } => Some(Set1::Empty),
34-
GenericParamDefKind::Lifetime => None,
35-
}
36-
})))
37-
}
38-
}
39-
40-
fn compute_object_lifetime_defaults<'tcx>(
41-
tcx: TyCtxt<'tcx>,
42-
item: &hir::Item<'_>,
43-
) -> Option<&'tcx [ObjectLifetimeDefault]> {
22+
let Node::Item(item) = tcx.hir().get_by_def_id(def_id) else { return None };
4423
match item.kind {
4524
hir::ItemKind::Struct(_, ref generics)
4625
| hir::ItemKind::Union(_, ref generics)
@@ -61,24 +40,18 @@ fn compute_object_lifetime_defaults<'tcx>(
6140
let object_lifetime_default_reprs: String = result
6241
.iter()
6342
.map(|set| match *set {
64-
Set1::Empty => "BaseDefault".into(),
65-
Set1::One(Region::Static) => "'static".into(),
66-
Set1::One(Region::EarlyBound(mut i, _)) => generics
67-
.params
68-
.iter()
69-
.find_map(|param| match param.kind {
70-
GenericParamKind::Lifetime { .. } => {
71-
if i == 0 {
72-
return Some(param.name.ident().to_string().into());
73-
}
74-
i -= 1;
75-
None
76-
}
77-
_ => None,
78-
})
79-
.unwrap(),
80-
Set1::One(_) => bug!(),
81-
Set1::Many => "Ambiguous".into(),
43+
ObjectLifetimeDefault::Empty => "BaseDefault".into(),
44+
ObjectLifetimeDefault::Static => "'static".into(),
45+
ObjectLifetimeDefault::Param(def_id) => {
46+
let def_id = def_id.expect_local();
47+
generics
48+
.params
49+
.iter()
50+
.find(|param| tcx.hir().local_def_id(param.hir_id) == def_id)
51+
.map(|param| param.name.ident().to_string().into())
52+
.unwrap()
53+
}
54+
ObjectLifetimeDefault::Ambiguous => "Ambiguous".into(),
8255
})
8356
.collect::<Vec<Cow<'static, str>>>()
8457
.join(",");
@@ -133,32 +106,20 @@ fn object_lifetime_defaults_for_item<'tcx>(
133106
}
134107

135108
Some(match set {
136-
Set1::Empty => Set1::Empty,
137-
Set1::One(hir::LifetimeName::Static) => Set1::One(Region::Static),
138-
Set1::One(hir::LifetimeName::Param(def_id, _)) => generics
139-
.params
140-
.iter()
141-
.filter_map(|param| match param.kind {
142-
GenericParamKind::Lifetime { .. } => {
143-
let param_def_id = tcx.hir().local_def_id(param.hir_id);
144-
Some(param_def_id)
145-
}
146-
_ => None,
147-
})
148-
.enumerate()
149-
.find(|&(_, param_def_id)| param_def_id == def_id)
150-
.map_or(Set1::Many, |(i, _)| {
151-
Set1::One(Region::EarlyBound(i as u32, def_id.to_def_id()))
152-
}),
153-
Set1::One(_) | Set1::Many => Set1::Many,
109+
Set1::Empty => ObjectLifetimeDefault::Empty,
110+
Set1::One(hir::LifetimeName::Static) => ObjectLifetimeDefault::Static,
111+
Set1::One(hir::LifetimeName::Param(def_id, _)) => {
112+
ObjectLifetimeDefault::Param(def_id.to_def_id())
113+
}
114+
Set1::One(_) | Set1::Many => ObjectLifetimeDefault::Ambiguous,
154115
})
155116
}
156117
GenericParamKind::Const { .. } => {
157118
// Generic consts don't impose any constraints.
158119
//
159120
// We still store a dummy value here to allow generic parameters
160121
// in an arbitrary order.
161-
Some(Set1::Empty)
122+
Some(ObjectLifetimeDefault::Empty)
162123
}
163124
};
164125

@@ -529,9 +490,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
529490
loop {
530491
match *scope {
531492
Scope::Root => break false,
532-
533493
Scope::Body => break true,
534-
535494
Scope::Binder { s, .. }
536495
| Scope::Static { s, .. }
537496
| Scope::ObjectLifetimeDefault { s, .. } => {
@@ -540,28 +499,37 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
540499
}
541500
}
542501
};
543-
544-
let set_to_region = |set: &ObjectLifetimeDefault| match *set {
545-
Set1::Empty => {
502+
let generics = self.tcx.generics_of(def_id);
503+
let set_to_region = |set: ObjectLifetimeDefault| match set {
504+
ObjectLifetimeDefault::Empty => {
546505
if in_body {
547506
None
548507
} else {
549508
Some(Region::Static)
550509
}
551510
}
552-
Set1::One(Region::EarlyBound(index, _)) => {
553-
let mut lifetimes = generic_args.args.iter().filter_map(|arg| match arg {
554-
GenericArg::Lifetime(lt) => Some(lt),
511+
ObjectLifetimeDefault::Static => Some(Region::Static),
512+
ObjectLifetimeDefault::Param(def_id) => {
513+
let index = generics.param_def_id_to_index[&def_id];
514+
generic_args.args.get(index as usize).and_then(|arg| match arg {
515+
GenericArg::Lifetime(lt) => self.tcx.named_region(lt.hir_id),
555516
_ => None,
556-
});
557-
lifetimes
558-
.nth(index as usize)
559-
.and_then(|lifetime| self.tcx.named_region(lifetime.hir_id))
517+
})
560518
}
561-
Set1::One(r) => Some(r),
562-
Set1::Many => None,
519+
ObjectLifetimeDefault::Ambiguous => None,
563520
};
564-
self.tcx.object_lifetime_defaults(def_id).unwrap().iter().map(set_to_region).collect()
521+
generics
522+
.params
523+
.iter()
524+
.filter_map(|param| match param.kind {
525+
GenericParamDefKind::Type { object_lifetime_default, .. } => {
526+
Some(object_lifetime_default)
527+
}
528+
GenericParamDefKind::Const { .. } => Some(ObjectLifetimeDefault::Empty),
529+
GenericParamDefKind::Lifetime => None,
530+
})
531+
.map(set_to_region)
532+
.collect()
565533
});
566534
debug!(?object_lifetime_defaults);
567535

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