Remove TypeckResults from InferCtxt

compiler/rustc_infer/src/infer/mod.rs

@@ -16,7 +16,6 @@ use rustc_data_structures::undo_log::Rollback;
 use rustc_data_structures::unify as ut;
 use rustc_errors::{DiagnosticBuilder, ErrorGuaranteed};
 use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::hir_id::OwnerId;
 use rustc_middle::infer::canonical::{Canonical, CanonicalVarValues};
 use rustc_middle::infer::unify_key::{ConstVarValue, ConstVariableValue};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind, ToType};
@@ -36,7 +35,7 @@ use rustc_middle::ty::{ConstVid, FloatVid, IntVid, TyVid};
 use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 
-use std::cell::{Cell, Ref, RefCell};
+use std::cell::{Cell, RefCell};
 use std::fmt;
 
 use self::combine::CombineFields;
@@ -254,7 +253,7 @@ pub enum DefiningAnchor {
     Error,
 }
 
-pub struct InferCtxt<'a, 'tcx> {
+pub struct InferCtxt<'tcx> {
     pub tcx: TyCtxt<'tcx>,
 
     /// The `DefId` of the item in whose context we are performing inference or typeck.
@@ -274,12 +273,6 @@ pub struct InferCtxt<'a, 'tcx> {
     /// solving is left to borrowck instead.
     pub considering_regions: bool,
 
-    /// During type-checking/inference of a body, `in_progress_typeck_results`
-    /// contains a reference to the typeck results being built up, which are
-    /// used for reading closure kinds/signatures as they are inferred,
-    /// and for error reporting logic to read arbitrary node types.
-    pub in_progress_typeck_results: Option<&'a RefCell<ty::TypeckResults<'tcx>>>,
-
     pub inner: RefCell<InferCtxtInner<'tcx>>,
 
     /// If set, this flag causes us to skip the 'leak check' during
@@ -342,7 +335,7 @@ pub struct InferCtxt<'a, 'tcx> {
     universe: Cell<ty::UniverseIndex>,
 
     normalize_fn_sig_for_diagnostic:
-        Option<Lrc<dyn Fn(&InferCtxt<'_, 'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>>,
+        Option<Lrc<dyn Fn(&InferCtxt<'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>>,
 }
 
 /// See the `error_reporting` module for more details.
@@ -553,16 +546,13 @@ impl<'tcx> fmt::Display for FixupError<'tcx> {
     }
 }
 
-/// A temporary returned by `tcx.infer_ctxt()`. This is necessary
-/// for multiple `InferCtxt` to share the same `in_progress_typeck_results`
-/// without using `Rc` or something similar.
+/// Used to configure inference contexts before their creation
 pub struct InferCtxtBuilder<'tcx> {
     tcx: TyCtxt<'tcx>,
     defining_use_anchor: DefiningAnchor,
     considering_regions: bool,
-    fresh_typeck_results: Option<RefCell<ty::TypeckResults<'tcx>>>,
     normalize_fn_sig_for_diagnostic:
-        Option<Lrc<dyn Fn(&InferCtxt<'_, 'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>>,
+        Option<Lrc<dyn Fn(&InferCtxt<'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>>,
 }
 
 pub trait TyCtxtInferExt<'tcx> {
@@ -575,26 +565,17 @@ impl<'tcx> TyCtxtInferExt<'tcx> for TyCtxt<'tcx> {
             tcx: self,
             defining_use_anchor: DefiningAnchor::Error,
             considering_regions: true,
-            fresh_typeck_results: None,
             normalize_fn_sig_for_diagnostic: None,
         }
     }
 }
 
 impl<'tcx> InferCtxtBuilder<'tcx> {
-    /// Used only by `rustc_hir_analysis` during body type-checking/inference,
-    /// will initialize `in_progress_typeck_results` with fresh `TypeckResults`.
-    /// Will also change the scope for opaque type defining use checks to the given owner.
-    pub fn with_fresh_in_progress_typeck_results(mut self, table_owner: OwnerId) -> Self {
-        self.fresh_typeck_results = Some(RefCell::new(ty::TypeckResults::new(table_owner)));
-        self.with_opaque_type_inference(DefiningAnchor::Bind(table_owner.def_id))
-    }
-
     /// Whenever the `InferCtxt` should be able to handle defining uses of opaque types,
     /// you need to call this function. Otherwise the opaque type will be treated opaquely.
     ///
     /// It is only meant to be called in two places, for typeck
-    /// (via `with_fresh_in_progress_typeck_results`) and for the inference context used
+    /// (via `Inherited::build`) and for the inference context used
     /// in mir borrowck.
     pub fn with_opaque_type_inference(mut self, defining_use_anchor: DefiningAnchor) -> Self {
         self.defining_use_anchor = defining_use_anchor;
@@ -608,7 +589,7 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
 
     pub fn with_normalize_fn_sig_for_diagnostic(
         mut self,
-        fun: Lrc<dyn Fn(&InferCtxt<'_, 'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>,
+        fun: Lrc<dyn Fn(&InferCtxt<'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>,
     ) -> Self {
         self.normalize_fn_sig_for_diagnostic = Some(fun);
         self
@@ -625,7 +606,7 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
         &mut self,
         span: Span,
         canonical: &Canonical<'tcx, T>,
-        f: impl for<'a> FnOnce(InferCtxt<'a, 'tcx>, T, CanonicalVarValues<'tcx>) -> R,
+        f: impl FnOnce(InferCtxt<'tcx>, T, CanonicalVarValues<'tcx>) -> R,
     ) -> R
     where
         T: TypeFoldable<'tcx>,
@@ -637,20 +618,17 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
         })
     }
 
-    pub fn enter<R>(&mut self, f: impl for<'a> FnOnce(InferCtxt<'a, 'tcx>) -> R) -> R {
+    pub fn enter<R>(&mut self, f: impl FnOnce(InferCtxt<'tcx>) -> R) -> R {
         let InferCtxtBuilder {
             tcx,
             defining_use_anchor,
             considering_regions,
-            ref fresh_typeck_results,
             ref normalize_fn_sig_for_diagnostic,
         } = *self;
-        let in_progress_typeck_results = fresh_typeck_results.as_ref();
         f(InferCtxt {
             tcx,
             defining_use_anchor,
             considering_regions,
-            in_progress_typeck_results,
             inner: RefCell::new(InferCtxtInner::new()),
             lexical_region_resolutions: RefCell::new(None),
             selection_cache: Default::default(),
@@ -677,7 +655,7 @@ impl<'tcx, T> InferOk<'tcx, T> {
     /// Extracts `value`, registering any obligations into `fulfill_cx`.
     pub fn into_value_registering_obligations(
         self,
-        infcx: &InferCtxt<'_, 'tcx>,
+        infcx: &InferCtxt<'tcx>,
         fulfill_cx: &mut dyn TraitEngine<'tcx>,
     ) -> T {
         let InferOk { value, obligations } = self;
@@ -693,18 +671,17 @@ impl<'tcx> InferOk<'tcx, ()> {
 }
 
 #[must_use = "once you start a snapshot, you should always consume it"]
-pub struct CombinedSnapshot<'a, 'tcx> {
+pub struct CombinedSnapshot<'tcx> {
     undo_snapshot: Snapshot<'tcx>,
     region_constraints_snapshot: RegionSnapshot,
     universe: ty::UniverseIndex,
     was_in_snapshot: bool,
-    _in_progress_typeck_results: Option<Ref<'a, ty::TypeckResults<'tcx>>>,
 }
 
-impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
+impl<'tcx> InferCtxt<'tcx> {
     /// Creates a `TypeErrCtxt` for emitting various inference errors.
     /// During typeck, use `FnCtxt::infer_err` instead.
-    pub fn err_ctxt(&'a self) -> TypeErrCtxt<'a, 'tcx> {
+    pub fn err_ctxt(&self) -> TypeErrCtxt<'_, 'tcx> {
         TypeErrCtxt { infcx: self, typeck_results: None }
     }
 
@@ -746,7 +723,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     /// if this is not a type variable.
     ///
     /// No attempt is made to resolve `ty`.
-    pub fn type_var_origin(&'a self, ty: Ty<'tcx>) -> Option<TypeVariableOrigin> {
+    pub fn type_var_origin(&self, ty: Ty<'tcx>) -> Option<TypeVariableOrigin> {
         match *ty.kind() {
             ty::Infer(ty::TyVar(vid)) => {
                 Some(*self.inner.borrow_mut().type_variables().var_origin(vid))
@@ -787,7 +764,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         vars
     }
 
-    fn combine_fields(
+    fn combine_fields<'a>(
         &'a self,
         trace: TypeTrace<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
@@ -829,7 +806,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         result
     }
 
-    fn start_snapshot(&self) -> CombinedSnapshot<'a, 'tcx> {
+    fn start_snapshot(&self) -> CombinedSnapshot<'tcx> {
         debug!("start_snapshot()");
 
         let in_snapshot = self.in_snapshot.replace(true);
@@ -841,22 +818,16 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             region_constraints_snapshot: inner.unwrap_region_constraints().start_snapshot(),
             universe: self.universe(),
             was_in_snapshot: in_snapshot,
-            // Borrow typeck results "in progress" (i.e., during typeck)
-            // to ban writes from within a snapshot to them.
-            _in_progress_typeck_results: self
-                .in_progress_typeck_results
-                .map(|typeck_results| typeck_results.borrow()),
         }
     }
 
     #[instrument(skip(self, snapshot), level = "debug")]
-    fn rollback_to(&self, cause: &str, snapshot: CombinedSnapshot<'a, 'tcx>) {
+    fn rollback_to(&self, cause: &str, snapshot: CombinedSnapshot<'tcx>) {
         let CombinedSnapshot {
             undo_snapshot,
             region_constraints_snapshot,
             universe,
             was_in_snapshot,
-            _in_progress_typeck_results,
         } = snapshot;
 
         self.in_snapshot.set(was_in_snapshot);
@@ -868,13 +839,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     }
 
     #[instrument(skip(self, snapshot), level = "debug")]
-    fn commit_from(&self, snapshot: CombinedSnapshot<'a, 'tcx>) {
+    fn commit_from(&self, snapshot: CombinedSnapshot<'tcx>) {
         let CombinedSnapshot {
             undo_snapshot,
             region_constraints_snapshot: _,
             universe: _,
             was_in_snapshot,
-            _in_progress_typeck_results,
         } = snapshot;
 
         self.in_snapshot.set(was_in_snapshot);
@@ -886,7 +856,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     #[instrument(skip(self, f), level = "debug")]
     pub fn commit_if_ok<T, E, F>(&self, f: F) -> Result<T, E>
     where
-        F: FnOnce(&CombinedSnapshot<'a, 'tcx>) -> Result<T, E>,
+        F: FnOnce(&CombinedSnapshot<'tcx>) -> Result<T, E>,
     {
         let snapshot = self.start_snapshot();
         let r = f(&snapshot);
@@ -906,7 +876,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     #[instrument(skip(self, f), level = "debug")]
     pub fn probe<R, F>(&self, f: F) -> R
     where
-        F: FnOnce(&CombinedSnapshot<'a, 'tcx>) -> R,
+        F: FnOnce(&CombinedSnapshot<'tcx>) -> R,
     {
         let snapshot = self.start_snapshot();
         let r = f(&snapshot);
@@ -918,7 +888,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     #[instrument(skip(self, f), level = "debug")]
     pub fn probe_maybe_skip_leak_check<R, F>(&self, should_skip: bool, f: F) -> R
     where
-        F: FnOnce(&CombinedSnapshot<'a, 'tcx>) -> R,
+        F: FnOnce(&CombinedSnapshot<'tcx>) -> R,
     {
         let snapshot = self.start_snapshot();
         let was_skip_leak_check = self.skip_leak_check.get();
@@ -938,7 +908,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     /// - `Some(false)` -- if there are `'a: 'b` constraints but none involve placeholders
     pub fn region_constraints_added_in_snapshot(
         &self,
-        snapshot: &CombinedSnapshot<'a, 'tcx>,
+        snapshot: &CombinedSnapshot<'tcx>,
     ) -> Option<bool> {
         self.inner
             .borrow_mut()
@@ -946,7 +916,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
             .region_constraints_added_in_snapshot(&snapshot.undo_snapshot)
     }
 
-    pub fn opaque_types_added_in_snapshot(&self, snapshot: &CombinedSnapshot<'a, 'tcx>) -> bool {
+    pub fn opaque_types_added_in_snapshot(&self, snapshot: &CombinedSnapshot<'tcx>) -> bool {
         self.inner.borrow().undo_log.opaque_types_in_snapshot(&snapshot.undo_snapshot)
     }
 
@@ -1519,7 +1489,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         }
 
         struct ToFreshVars<'a, 'tcx> {
-            infcx: &'a InferCtxt<'a, 'tcx>,
+            infcx: &'a InferCtxt<'tcx>,
             span: Span,
             lbrct: LateBoundRegionConversionTime,
             map: FxHashMap<ty::BoundVar, ty::GenericArg<'tcx>>,
@@ -1893,7 +1863,7 @@ impl<'tcx> TypeFolder<'tcx> for InferenceLiteralEraser<'tcx> {
 }
 
 struct ShallowResolver<'a, 'tcx> {
-    infcx: &'a InferCtxt<'a, 'tcx>,
+    infcx: &'a InferCtxt<'tcx>,
 }
 
 impl<'a, 'tcx> TypeFolder<'tcx> for ShallowResolver<'a, 'tcx> {