BorrowckInferCtxt: infcx by value

compiler/rustc_borrowck/src/lib.rs

@@ -23,9 +23,8 @@ use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
 use rustc_index::bit_set::{BitSet, ChunkedBitSet};
 use rustc_index::{IndexSlice, IndexVec};
-use rustc_infer::infer::{
-    InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin, TyCtxtInferExt,
-};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin};
 use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::mir::*;
 use rustc_middle::query::Providers;
@@ -123,9 +122,8 @@ fn mir_borrowck(tcx: TyCtxt<'_>, def: LocalDefId) -> &BorrowCheckResult<'_> {
         return tcx.arena.alloc(result);
     }
 
-    let infcx = tcx.infer_ctxt().with_opaque_type_inference(def).build();
     let promoted: &IndexSlice<_, _> = &promoted.borrow();
-    let opt_closure_req = do_mir_borrowck(&infcx, input_body, promoted, None).0;
+    let opt_closure_req = do_mir_borrowck(tcx, input_body, promoted, None).0;
     debug!("mir_borrowck done");
 
     tcx.arena.alloc(opt_closure_req)
@@ -136,18 +134,15 @@ fn mir_borrowck(tcx: TyCtxt<'_>, def: LocalDefId) -> &BorrowCheckResult<'_> {
 /// Use `consumer_options: None` for the default behavior of returning
 /// [`BorrowCheckResult`] only. Otherwise, return [`BodyWithBorrowckFacts`] according
 /// to the given [`ConsumerOptions`].
-#[instrument(skip(infcx, input_body, input_promoted), fields(id=?input_body.source.def_id()), level = "debug")]
+#[instrument(skip(tcx, input_body, input_promoted), fields(id=?input_body.source.def_id()), level = "debug")]
 fn do_mir_borrowck<'tcx>(
-    infcx: &InferCtxt<'tcx>,
+    tcx: TyCtxt<'tcx>,
     input_body: &Body<'tcx>,
     input_promoted: &IndexSlice<Promoted, Body<'tcx>>,
     consumer_options: Option<ConsumerOptions>,
 ) -> (BorrowCheckResult<'tcx>, Option<Box<BodyWithBorrowckFacts<'tcx>>>) {
     let def = input_body.source.def_id().expect_local();
-    debug!(?def);
-
-    let tcx = infcx.tcx;
-    let infcx = BorrowckInferCtxt::new(infcx);
+    let infcx = BorrowckInferCtxt::new(tcx, def);
     let param_env = tcx.param_env(def);
 
     let mut local_names = IndexVec::from_elem(None, &input_body.local_decls);
@@ -440,13 +435,14 @@ fn do_mir_borrowck<'tcx>(
     (result, body_with_facts)
 }
 
-pub struct BorrowckInferCtxt<'cx, 'tcx> {
-    pub(crate) infcx: &'cx InferCtxt<'tcx>,
+pub struct BorrowckInferCtxt<'tcx> {
+    pub(crate) infcx: InferCtxt<'tcx>,
     pub(crate) reg_var_to_origin: RefCell<FxIndexMap<ty::RegionVid, RegionCtxt>>,
 }
 
-impl<'cx, 'tcx> BorrowckInferCtxt<'cx, 'tcx> {
-    pub(crate) fn new(infcx: &'cx InferCtxt<'tcx>) -> Self {
+impl<'tcx> BorrowckInferCtxt<'tcx> {
+    pub(crate) fn new(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Self {
+        let infcx = tcx.infer_ctxt().with_opaque_type_inference(def_id).build();
         BorrowckInferCtxt { infcx, reg_var_to_origin: RefCell::new(Default::default()) }
     }
 
@@ -494,16 +490,16 @@ impl<'cx, 'tcx> BorrowckInferCtxt<'cx, 'tcx> {
     }
 }
 
-impl<'cx, 'tcx> Deref for BorrowckInferCtxt<'cx, 'tcx> {
+impl<'tcx> Deref for BorrowckInferCtxt<'tcx> {
     type Target = InferCtxt<'tcx>;
 
-    fn deref(&self) -> &'cx Self::Target {
-        self.infcx
+    fn deref(&self) -> &Self::Target {
+        &self.infcx
     }
 }
 
 struct MirBorrowckCtxt<'cx, 'tcx> {
-    infcx: &'cx BorrowckInferCtxt<'cx, 'tcx>,
+    infcx: &'cx BorrowckInferCtxt<'tcx>,
     param_env: ParamEnv<'tcx>,
     body: &'cx Body<'tcx>,
     move_data: &'cx MoveData<'tcx>,