From afa884c03a90f4d773e28faaad4bc7845d677332 Mon Sep 17 00:00:00 2001
From: scalexm <alexandre@scalexm.fr>
Date: Thu, 1 Nov 2018 15:30:37 +0100
Subject: [PATCH] Instantiate all bound vars existentially
---
src/librustc/infer/canonical/substitute.rs | 2 +-
src/librustc/infer/higher_ranked/mod.rs | 10 +++----
src/librustc/infer/mod.rs | 12 ++++----
src/librustc/traits/error_reporting.rs | 5 ++--
src/librustc/ty/fold.rs | 30 +++++++++----------
.../nll/type_check/input_output.rs | 2 +-
.../borrow_check/nll/type_check/mod.rs | 2 +-
src/librustc_traits/chalk_context/mod.rs | 7 ++---
src/librustc_typeck/check/callee.rs | 11 +++----
src/librustc_typeck/check/closure.rs | 4 +--
src/librustc_typeck/check/compare_method.rs | 11 +++----
src/librustc_typeck/check/method/confirm.rs | 12 ++++----
src/librustc_typeck/check/method/mod.rs | 8 +++--
src/librustc_typeck/check/method/probe.rs | 7 +++--
src/librustc_typeck/check/mod.rs | 10 +++----
15 files changed, 68 insertions(+), 65 deletions(-)
diff --git a/src/librustc/infer/canonical/substitute.rs b/src/librustc/infer/canonical/substitute.rs
index b8c1ed236c0..70ce5d0d8dc 100644
--- a/src/librustc/infer/canonical/substitute.rs
+++ b/src/librustc/infer/canonical/substitute.rs
@@ -80,6 +80,6 @@ where
}
};
- tcx.replace_escaping_bound_vars(value, fld_r, fld_t)
+ tcx.replace_escaping_bound_vars(value, fld_r, fld_t).0
}
}
diff --git a/src/librustc/infer/higher_ranked/mod.rs b/src/librustc/infer/higher_ranked/mod.rs
index 3e08a4e021a..642382bcf0f 100644
--- a/src/librustc/infer/higher_ranked/mod.rs
+++ b/src/librustc/infer/higher_ranked/mod.rs
@@ -59,11 +59,11 @@ impl<'a, 'gcx, 'tcx> CombineFields<'a, 'gcx, 'tcx> {
// with a fresh region variable. These region variables --
// but no other pre-existing region variables -- can name
// the placeholders.
- let (a_prime, _) =
- self.infcx.replace_late_bound_regions_with_fresh_var(
- span,
- HigherRankedType,
- a);
+ let (a_prime, _) = self.infcx.replace_bound_vars_with_fresh_vars(
+ span,
+ HigherRankedType,
+ a
+ );
debug!("a_prime={:?}", a_prime);
debug!("b_prime={:?}", b_prime);
diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs
index f5513acecf9..4ddf47c88dd 100644
--- a/src/librustc/infer/mod.rs
+++ b/src/librustc/infer/mod.rs
@@ -1328,18 +1328,18 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
self.report_and_explain_type_error(trace, &err)
}
- pub fn replace_late_bound_regions_with_fresh_var<T>(
+ pub fn replace_bound_vars_with_fresh_vars<T>(
&self,
span: Span,
lbrct: LateBoundRegionConversionTime,
- value: &ty::Binder<T>,
+ value: &ty::Binder<T>
) -> (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)
where
- T: TypeFoldable<'tcx>,
+ T: TypeFoldable<'tcx>
{
- self.tcx.replace_late_bound_regions(value, |br| {
- self.next_region_var(LateBoundRegion(span, br, lbrct))
- })
+ let fld_r = |br| self.next_region_var(LateBoundRegion(span, br, lbrct));
+ let fld_t = |_| self.next_ty_var(TypeVariableOrigin::MiscVariable(span));
+ self.tcx.replace_bound_vars(value, fld_r, fld_t)
}
/// Given a higher-ranked projection predicate like:
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index fbada789956..2761a954cea 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -212,10 +212,11 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
// cause I have no idea for a good error message.
if let ty::Predicate::Projection(ref data) = predicate {
let mut selcx = SelectionContext::new(self);
- let (data, _) = self.replace_late_bound_regions_with_fresh_var(
+ let (data, _) = self.replace_bound_vars_with_fresh_vars(
obligation.cause.span,
infer::LateBoundRegionConversionTime::HigherRankedType,
- data);
+ data
+ );
let mut obligations = vec![];
let normalized_ty = super::normalize_projection_type(
&mut selcx,
diff --git a/src/librustc/ty/fold.rs b/src/librustc/ty/fold.rs
index ffa4380a5d6..a897afa0ca6 100644
--- a/src/librustc/ty/fold.rs
+++ b/src/librustc/ty/fold.rs
@@ -520,22 +520,14 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
pub fn replace_late_bound_regions<T, F>(
self,
value: &Binder<T>,
- mut fld_r: F
+ fld_r: F
) -> (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)
where F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
T: TypeFoldable<'tcx>
{
- let mut map = BTreeMap::new();
- let mut real_fldr = |br| {
- *map.entry(br).or_insert_with(|| fld_r(br))
- };
-
// identity for bound types
- let mut fld_t = |bound_ty| self.mk_ty(ty::Bound(bound_ty));
-
- let mut replacer = BoundVarReplacer::new(self, &mut real_fldr, &mut fld_t);
- let result = value.skip_binder().fold_with(&mut replacer);
- (result, map)
+ let fld_t = |bound_ty| self.mk_ty(ty::Bound(bound_ty));
+ self.replace_escaping_bound_vars(value.skip_binder(), fld_r, fld_t)
}
/// Replace all escaping bound vars. The `fld_r` closure replaces escaping
@@ -545,17 +537,23 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
value: &T,
mut fld_r: F,
mut fld_t: G
- ) -> T
+ ) -> (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)
where F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
G: FnMut(ty::BoundTy) -> ty::Ty<'tcx>,
T: TypeFoldable<'tcx>
{
+ let mut map = BTreeMap::new();
+
if !value.has_escaping_bound_vars() {
- value.clone()
+ (value.clone(), map)
} else {
- let mut replacer = BoundVarReplacer::new(self, &mut fld_r, &mut fld_t);
+ let mut real_fld_r = |br| {
+ *map.entry(br).or_insert_with(|| fld_r(br))
+ };
+
+ let mut replacer = BoundVarReplacer::new(self, &mut real_fld_r, &mut fld_t);
let result = value.fold_with(&mut replacer);
- result
+ (result, map)
}
}
@@ -567,7 +565,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
value: &Binder<T>,
fld_r: F,
fld_t: G
- ) -> T
+ ) -> (T, BTreeMap<ty::BoundRegion, ty::Region<'tcx>>)
where F: FnMut(ty::BoundRegion) -> ty::Region<'tcx>,
G: FnMut(ty::BoundTy) -> ty::Ty<'tcx>,
T: TypeFoldable<'tcx>
diff --git a/src/librustc_mir/borrow_check/nll/type_check/input_output.rs b/src/librustc_mir/borrow_check/nll/type_check/input_output.rs
index ab4ee3a4ad0..85ea39e538f 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/input_output.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/input_output.rs
@@ -62,7 +62,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
// "inside" the closure.
Some(
self.infcx
- .replace_late_bound_regions_with_fresh_var(
+ .replace_bound_vars_with_fresh_vars(
mir.span,
LateBoundRegionConversionTime::FnCall,
&poly_sig,
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index c8d2bcd8b93..2193dba9fca 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -1406,7 +1406,7 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
return;
}
};
- let (sig, map) = self.infcx.replace_late_bound_regions_with_fresh_var(
+ let (sig, map) = self.infcx.replace_bound_vars_with_fresh_vars(
term.source_info.span,
LateBoundRegionConversionTime::FnCall,
&sig,
diff --git a/src/librustc_traits/chalk_context/mod.rs b/src/librustc_traits/chalk_context/mod.rs
index 611cace45df..0fd9f607a54 100644
--- a/src/librustc_traits/chalk_context/mod.rs
+++ b/src/librustc_traits/chalk_context/mod.rs
@@ -347,12 +347,11 @@ impl context::UnificationOps<ChalkArenas<'gcx>, ChalkArenas<'tcx>>
&mut self,
arg: &ty::Binder<Goal<'tcx>>,
) -> Goal<'tcx> {
- let (value, _map) = self.infcx.replace_late_bound_regions_with_fresh_var(
+ self.infcx.replace_bound_vars_with_fresh_vars(
DUMMY_SP,
LateBoundRegionConversionTime::HigherRankedType,
- arg,
- );
- value
+ arg
+ ).0
}
fn debug_ex_clause(&mut self, value: &'v ChalkExClause<'tcx>) -> Box<dyn Debug + 'v> {
diff --git a/src/librustc_typeck/check/callee.rs b/src/librustc_typeck/check/callee.rs
index de4293aaaea..411583b36b9 100644
--- a/src/librustc_typeck/check/callee.rs
+++ b/src/librustc_typeck/check/callee.rs
@@ -110,10 +110,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// fnmut vs fnonce. If so, we have to defer further processing.
if self.closure_kind(def_id, substs).is_none() {
let closure_ty = self.closure_sig(def_id, substs);
- let fn_sig = self.replace_late_bound_regions_with_fresh_var(call_expr.span,
- infer::FnCall,
- &closure_ty)
- .0;
+ let fn_sig = self.replace_bound_vars_with_fresh_vars(
+ call_expr.span,
+ infer::FnCall,
+ &closure_ty
+ ).0;
let adjustments = autoderef.adjust_steps(Needs::None);
self.record_deferred_call_resolution(def_id, DeferredCallResolution {
call_expr,
@@ -284,7 +285,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// previously appeared within a `Binder<>` and hence would not
// have been normalized before.
let fn_sig =
- self.replace_late_bound_regions_with_fresh_var(call_expr.span, infer::FnCall, &fn_sig)
+ self.replace_bound_vars_with_fresh_vars(call_expr.span, infer::FnCall, &fn_sig)
.0;
let fn_sig = self.normalize_associated_types_in(call_expr.span, &fn_sig);
diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs
index 010561d1001..10ac2448d00 100644
--- a/src/librustc_typeck/check/closure.rs
+++ b/src/librustc_typeck/check/closure.rs
@@ -564,7 +564,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// `liberated_sig` is E'.
{
// Instantiate (this part of..) S to S', i.e., with fresh variables.
- let (supplied_ty, _) = self.infcx.replace_late_bound_regions_with_fresh_var(
+ let (supplied_ty, _) = self.infcx.replace_bound_vars_with_fresh_vars(
hir_ty.span,
LateBoundRegionConversionTime::FnCall,
&ty::Binder::bind(supplied_ty),
@@ -605,7 +605,7 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
);
}
- let (supplied_output_ty, _) = self.infcx.replace_late_bound_regions_with_fresh_var(
+ let (supplied_output_ty, _) = self.infcx.replace_bound_vars_with_fresh_vars(
decl.output.span(),
LateBoundRegionConversionTime::FnCall,
&supplied_sig.output(),
diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs
index 45c5457c9e1..e30ebe07e54 100644
--- a/src/librustc_typeck/check/compare_method.rs
+++ b/src/librustc_typeck/check/compare_method.rs
@@ -233,7 +233,7 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
let mut selcx = traits::SelectionContext::new(&infcx);
let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_skol_substs);
- let (impl_m_own_bounds, _) = infcx.replace_late_bound_regions_with_fresh_var(
+ let (impl_m_own_bounds, _) = infcx.replace_bound_vars_with_fresh_vars(
impl_m_span,
infer::HigherRankedType,
&ty::Binder::bind(impl_m_own_bounds.predicates)
@@ -262,10 +262,11 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
// Compute placeholder form of impl and trait method tys.
let tcx = infcx.tcx;
- let (impl_sig, _) =
- infcx.replace_late_bound_regions_with_fresh_var(impl_m_span,
- infer::HigherRankedType,
- &tcx.fn_sig(impl_m.def_id));
+ let (impl_sig, _) = infcx.replace_bound_vars_with_fresh_vars(
+ impl_m_span,
+ infer::HigherRankedType,
+ &tcx.fn_sig(impl_m.def_id)
+ );
let impl_sig =
inh.normalize_associated_types_in(impl_m_span,
impl_m_node_id,
diff --git a/src/librustc_typeck/check/method/confirm.rs b/src/librustc_typeck/check/method/confirm.rs
index 75f5bf74c6a..5144f3e41d4 100644
--- a/src/librustc_typeck/check/method/confirm.rs
+++ b/src/librustc_typeck/check/method/confirm.rs
@@ -245,7 +245,7 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
let original_poly_trait_ref = principal.with_self_ty(this.tcx, object_ty);
let upcast_poly_trait_ref = this.upcast(original_poly_trait_ref, trait_def_id);
let upcast_trait_ref =
- this.replace_late_bound_regions_with_fresh_var(&upcast_poly_trait_ref);
+ this.replace_bound_vars_with_fresh_vars(&upcast_poly_trait_ref);
debug!("original_poly_trait_ref={:?} upcast_trait_ref={:?} target_trait={:?}",
original_poly_trait_ref,
upcast_trait_ref,
@@ -268,7 +268,7 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
probe::WhereClausePick(ref poly_trait_ref) => {
// Where clauses can have bound regions in them. We need to instantiate
// those to convert from a poly-trait-ref to a trait-ref.
- self.replace_late_bound_regions_with_fresh_var(&poly_trait_ref).substs
+ self.replace_bound_vars_with_fresh_vars(&poly_trait_ref).substs
}
}
}
@@ -398,7 +398,7 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
// NB: Instantiate late-bound regions first so that
// `instantiate_type_scheme` can normalize associated types that
// may reference those regions.
- let method_sig = self.replace_late_bound_regions_with_fresh_var(&sig);
+ let method_sig = self.replace_bound_vars_with_fresh_vars(&sig);
debug!("late-bound lifetimes from method instantiated, method_sig={:?}",
method_sig);
@@ -633,11 +633,9 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
upcast_trait_refs.into_iter().next().unwrap()
}
- fn replace_late_bound_regions_with_fresh_var<T>(&self, value: &ty::Binder<T>) -> T
+ fn replace_bound_vars_with_fresh_vars<T>(&self, value: &ty::Binder<T>) -> T
where T: TypeFoldable<'tcx>
{
- self.fcx
- .replace_late_bound_regions_with_fresh_var(self.span, infer::FnCall, value)
- .0
+ self.fcx.replace_bound_vars_with_fresh_vars(self.span, infer::FnCall, value).0
}
}
diff --git a/src/librustc_typeck/check/method/mod.rs b/src/librustc_typeck/check/method/mod.rs
index 637f3eaae9a..ac338ba6678 100644
--- a/src/librustc_typeck/check/method/mod.rs
+++ b/src/librustc_typeck/check/method/mod.rs
@@ -311,9 +311,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
// `instantiate_type_scheme` can normalize associated types that
// may reference those regions.
let fn_sig = tcx.fn_sig(def_id);
- let fn_sig = self.replace_late_bound_regions_with_fresh_var(span,
- infer::FnCall,
- &fn_sig).0;
+ let fn_sig = self.replace_bound_vars_with_fresh_vars(
+ span,
+ infer::FnCall,
+ &fn_sig
+ ).0;
let fn_sig = fn_sig.subst(self.tcx, substs);
let fn_sig = match self.normalize_associated_types_in_as_infer_ok(span, &fn_sig) {
InferOk { value, obligations: o } => {
diff --git a/src/librustc_typeck/check/method/probe.rs b/src/librustc_typeck/check/method/probe.rs
index 305efd0d75a..4c06cae1d07 100644
--- a/src/librustc_typeck/check/method/probe.rs
+++ b/src/librustc_typeck/check/method/probe.rs
@@ -755,8 +755,11 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> {
self.probe(|_| {
let substs = self.fresh_substs_for_item(self.span, method.def_id);
let fty = fty.subst(self.tcx, substs);
- let (fty, _) = self.replace_late_bound_regions_with_fresh_var(
- self.span, infer::FnCall, &fty);
+ let (fty, _) = self.replace_bound_vars_with_fresh_vars(
+ self.span,
+ infer::FnCall,
+ &fty
+ );
if let Some(self_ty) = self_ty {
if self.at(&ObligationCause::dummy(), self.param_env)
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 2e6797ef23a..41e0c6c0a19 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1921,11 +1921,11 @@ impl<'a, 'gcx, 'tcx> AstConv<'gcx, 'tcx> for FnCtxt<'a, 'gcx, 'tcx> {
poly_trait_ref: ty::PolyTraitRef<'tcx>)
-> Ty<'tcx>
{
- let (trait_ref, _) =
- self.replace_late_bound_regions_with_fresh_var(
- span,
- infer::LateBoundRegionConversionTime::AssocTypeProjection(item_def_id),
- &poly_trait_ref);
+ let (trait_ref, _) = self.replace_bound_vars_with_fresh_vars(
+ span,
+ infer::LateBoundRegionConversionTime::AssocTypeProjection(item_def_id),
+ &poly_trait_ref
+ );
self.tcx().mk_projection(item_def_id, trait_ref.substs)
}