diff --git a/src/librustc/infer/equate.rs b/src/librustc/infer/equate.rs
index 5dfa0d29daf1b..96d40bc81add2 100644
--- a/src/librustc/infer/equate.rs
+++ b/src/librustc/infer/equate.rs
@@ -97,7 +97,7 @@ impl TypeRelation<'tcx> for Equate<'combine, 'infcx, 'tcx> {
self.tag(),
a,
b);
- let origin = Subtype(self.fields.trace.clone());
+ let origin = Subtype(box self.fields.trace.clone());
self.fields.infcx.borrow_region_constraints()
.make_eqregion(origin, a, b);
Ok(a)
diff --git a/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs b/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
index b4fb018920647..5f3c5fed3a3b2 100644
--- a/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
+++ b/src/librustc/infer/error_reporting/nice_region_error/placeholder_error.rs
@@ -30,7 +30,7 @@ impl NiceRegionError<'me, 'tcx> {
Some(RegionResolutionError::SubSupConflict(
vid,
_,
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
@@ -50,7 +50,7 @@ impl NiceRegionError<'me, 'tcx> {
Some(RegionResolutionError::SubSupConflict(
vid,
_,
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
@@ -70,7 +70,7 @@ impl NiceRegionError<'me, 'tcx> {
Some(RegionResolutionError::SubSupConflict(
vid,
_,
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
@@ -92,7 +92,7 @@ impl NiceRegionError<'me, 'tcx> {
_,
_,
_,
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
@@ -108,7 +108,7 @@ impl NiceRegionError<'me, 'tcx> {
)),
Some(RegionResolutionError::ConcreteFailure(
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
@@ -125,7 +125,7 @@ impl NiceRegionError<'me, 'tcx> {
)),
Some(RegionResolutionError::ConcreteFailure(
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
@@ -142,7 +142,7 @@ impl NiceRegionError<'me, 'tcx> {
)),
Some(RegionResolutionError::ConcreteFailure(
- SubregionOrigin::Subtype(TypeTrace {
+ SubregionOrigin::Subtype(box TypeTrace {
cause,
values: ValuePairs::TraitRefs(ExpectedFound { expected, found }),
}),
diff --git a/src/librustc/infer/error_reporting/note.rs b/src/librustc/infer/error_reporting/note.rs
index caed4288892ef..115ffea97bf1a 100644
--- a/src/librustc/infer/error_reporting/note.rs
+++ b/src/librustc/infer/error_reporting/note.rs
@@ -138,7 +138,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
sup: Region<'tcx>)
-> DiagnosticBuilder<'tcx> {
match origin {
- infer::Subtype(trace) => {
+ infer::Subtype(box trace) => {
let terr = TypeError::RegionsDoesNotOutlive(sup, sub);
let mut err = self.report_and_explain_type_error(trace, &terr);
self.tcx.note_and_explain_region(region_scope_tree, &mut err, "", sup, "...");
@@ -450,7 +450,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
) -> DiagnosticBuilder<'tcx> {
// I can't think how to do better than this right now. -nikomatsakis
match placeholder_origin {
- infer::Subtype(trace) => {
+ infer::Subtype(box trace) => {
let terr = TypeError::RegionsPlaceholderMismatch;
self.report_and_explain_type_error(trace, &terr)
}
diff --git a/src/librustc/infer/glb.rs b/src/librustc/infer/glb.rs
index 2cef521176269..10e45321a6d6a 100644
--- a/src/librustc/infer/glb.rs
+++ b/src/librustc/infer/glb.rs
@@ -57,7 +57,7 @@ impl TypeRelation<'tcx> for Glb<'combine, 'infcx, 'tcx> {
a,
b);
- let origin = Subtype(self.fields.trace.clone());
+ let origin = Subtype(box self.fields.trace.clone());
Ok(self.fields.infcx.borrow_region_constraints().glb_regions(self.tcx(), origin, a, b))
}
diff --git a/src/librustc/infer/lub.rs b/src/librustc/infer/lub.rs
index e20372f151371..8b64cda7bd26d 100644
--- a/src/librustc/infer/lub.rs
+++ b/src/librustc/infer/lub.rs
@@ -57,7 +57,7 @@ impl TypeRelation<'tcx> for Lub<'combine, 'infcx, 'tcx> {
a,
b);
- let origin = Subtype(self.fields.trace.clone());
+ let origin = Subtype(box self.fields.trace.clone());
Ok(self.fields.infcx.borrow_region_constraints().lub_regions(self.tcx(), origin, a, b))
}
diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs
index 8638f42976f04..a886c44a4792d 100644
--- a/src/librustc/infer/mod.rs
+++ b/src/librustc/infer/mod.rs
@@ -254,7 +254,7 @@ pub struct TypeTrace<'tcx> {
#[derive(Clone, Debug)]
pub enum SubregionOrigin<'tcx> {
/// Arose from a subtyping relation
- Subtype(TypeTrace<'tcx>),
+ Subtype(Box<TypeTrace<'tcx>>),
/// Stack-allocated closures cannot outlive innermost loop
/// or function so as to ensure we only require finite stack
@@ -340,6 +340,10 @@ pub enum SubregionOrigin<'tcx> {
},
}
+// `SubregionOrigin` is used a lot. Make sure it doesn't unintentionally get bigger.
+#[cfg(target_arch = "x86_64")]
+static_assert_size!(SubregionOrigin<'_>, 32);
+
/// Places that type/region parameters can appear.
#[derive(Clone, Copy, Debug)]
pub enum ParameterOrigin {
diff --git a/src/librustc/infer/sub.rs b/src/librustc/infer/sub.rs
index cd1d206b5fca1..76db55ecfa8ef 100644
--- a/src/librustc/infer/sub.rs
+++ b/src/librustc/infer/sub.rs
@@ -130,7 +130,7 @@ impl TypeRelation<'tcx> for Sub<'combine, 'infcx, 'tcx> {
// FIXME -- we have more fine-grained information available
// from the "cause" field, we could perhaps give more tailored
// error messages.
- let origin = SubregionOrigin::Subtype(self.fields.trace.clone());
+ let origin = SubregionOrigin::Subtype(box self.fields.trace.clone());
self.fields.infcx.borrow_region_constraints()
.make_subregion(origin, a, b);