some conditional imports

compiler/rustc_borrowck/src/lib.rs

@@ -97,6 +97,7 @@
 use place_ext::PlaceExt;
 use places_conflict::{places_conflict, PlaceConflictBias};
 use region_infer::RegionInferenceContext;
+#[cfg(debug_assertions)]
 use renumber::RegionCtxt;
 
 // FIXME(eddyb) perhaps move this somewhere more centrally.

compiler/rustc_borrowck/src/nll.rs

@@ -257,11 +257,6 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
         borrow_set,
     );
 
-    if cfg!(debug_assertions) {
-        let var_to_origin = infcx.reg_var_to_origin.borrow();
-        debug!("var_to_origin: {:#?}", var_to_origin);
-    }
-
     let mut regioncx = RegionInferenceContext::new(
         infcx,
         var_origins,

compiler/rustc_borrowck/src/renumber.rs

@@ -8,6 +8,7 @@
 use rustc_middle::mir::{Body, Location, Promoted};
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
+#[cfg(debug_assertions)]
 use rustc_span::Symbol;
 
 /// Replaces all free regions appearing in the MIR with fresh

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -9,6 +9,7 @@
 
 use crate::constraints::OutlivesConstraint;
 use crate::diagnostics::UniverseInfo;
+#[cfg(debug_assertions)]
 use crate::renumber::RegionCtxt;
 use crate::type_check::{InstantiateOpaqueType, Locations, TypeChecker};
 

compiler/rustc_borrowck/src/universal_regions.rs

@@ -26,10 +26,12 @@
     self, DefIdTree, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt,
 };
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
+#[cfg(debug_assertions)]
 use rustc_span::Symbol;
 use std::iter;
 
 use crate::nll::ToRegionVid;
+#[cfg(debug_assertions)]
 use crate::renumber::RegionCtxt;
 use crate::BorrowckInferCtxt;