Adding upstream version 1.65.0+dfsg1.upstream/1.65.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 82 insertions, 44 deletions

diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index d7d1b5fa2..3abed1221 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -20,6 +20,7 @@ use rustc_middle::infer::canonical::{Canonical, CanonicalVarValues};
 use rustc_middle::infer::unify_key::{ConstVarValue, ConstVariableValue};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind, ToType};
 use rustc_middle::mir::interpret::{ErrorHandled, EvalToValTreeResult};
+use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::traits::select;
 use rustc_middle::ty::abstract_const::{AbstractConst, FailureKind};
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
@@ -32,7 +33,7 @@ pub use rustc_middle::ty::IntVarValue;
 use rustc_middle::ty::{self, GenericParamDefKind, InferConst, Ty, TyCtxt};
 use rustc_middle::ty::{ConstVid, FloatVid, IntVid, TyVid};
 use rustc_span::symbol::Symbol;
-use rustc_span::Span;
+use rustc_span::{Span, DUMMY_SP};
 
 use std::cell::{Cell, Ref, RefCell};
 use std::fmt;
@@ -316,12 +317,12 @@ pub struct InferCtxt<'a, 'tcx> {
     ///
     /// Don't read this flag directly, call `is_tainted_by_errors()`
     /// and `set_tainted_by_errors()`.
-    tainted_by_errors_flag: Cell<bool>,
+    tainted_by_errors: Cell<Option<ErrorGuaranteed>>,
 
     /// Track how many errors were reported when this infcx is created.
     /// If the number of errors increases, that's also a sign (line
     /// `tainted_by_errors`) to avoid reporting certain kinds of errors.
-    // FIXME(matthewjasper) Merge into `tainted_by_errors_flag`
+    // FIXME(matthewjasper) Merge into `tainted_by_errors`
     err_count_on_creation: usize,
 
     /// This flag is true while there is an active snapshot.
@@ -337,6 +338,9 @@ pub struct InferCtxt<'a, 'tcx> {
     /// when we enter into a higher-ranked (`for<..>`) type or trait
     /// bound.
     universe: Cell<ty::UniverseIndex>,
+
+    normalize_fn_sig_for_diagnostic:
+        Option<Lrc<dyn Fn(&InferCtxt<'_, 'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>>,
 }
 
 /// See the `error_reporting` module for more details.
@@ -350,12 +354,11 @@ pub enum ValuePairs<'tcx> {
 
 impl<'tcx> ValuePairs<'tcx> {
     pub fn ty(&self) -> Option<(Ty<'tcx>, Ty<'tcx>)> {
-        if let ValuePairs::Terms(ExpectedFound {
-            expected: ty::Term::Ty(expected),
-            found: ty::Term::Ty(found),
-        }) = self
+        if let ValuePairs::Terms(ExpectedFound { expected, found }) = self
+            && let Some(expected) = expected.ty()
+            && let Some(found) = found.ty()
         {
-            Some((*expected, *found))
+            Some((expected, found))
         } else {
             None
         }
@@ -406,7 +409,11 @@ pub enum SubregionOrigin<'tcx> {
 
     /// Comparing the signature and requirements of an impl method against
     /// the containing trait.
-    CompareImplItemObligation { span: Span, impl_item_def_id: LocalDefId, trait_item_def_id: DefId },
+    CompareImplItemObligation {
+        span: Span,
+        impl_item_def_id: LocalDefId,
+        trait_item_def_id: DefId,
+    },
 
     /// Checking that the bounds of a trait's associated type hold for a given impl
     CheckAssociatedTypeBounds {
@@ -414,12 +421,24 @@ pub enum SubregionOrigin<'tcx> {
         impl_item_def_id: LocalDefId,
         trait_item_def_id: DefId,
     },
+
+    AscribeUserTypeProvePredicate(Span),
 }
 
 // `SubregionOrigin` is used a lot. Make sure it doesn't unintentionally get bigger.
 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 static_assert_size!(SubregionOrigin<'_>, 32);
 
+impl<'tcx> SubregionOrigin<'tcx> {
+    pub fn to_constraint_category(&self) -> ConstraintCategory<'tcx> {
+        match self {
+            Self::Subtype(type_trace) => type_trace.cause.to_constraint_category(),
+            Self::AscribeUserTypeProvePredicate(span) => ConstraintCategory::Predicate(*span),
+            _ => ConstraintCategory::BoringNoLocation,
+        }
+    }
+}
+
 /// Times when we replace late-bound regions with variables:
 #[derive(Clone, Copy, Debug)]
 pub enum LateBoundRegionConversionTime {
@@ -504,7 +523,7 @@ pub enum FixupError<'tcx> {
 }
 
 /// See the `region_obligations` field for more information.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct RegionObligation<'tcx> {
     pub sub_region: ty::Region<'tcx>,
     pub sup_type: Ty<'tcx>,
@@ -540,6 +559,8 @@ pub struct InferCtxtBuilder<'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>>>,
 }
 
 pub trait TyCtxtInferExt<'tcx> {
@@ -553,6 +574,7 @@ impl<'tcx> TyCtxtInferExt<'tcx> for TyCtxt<'tcx> {
             defining_use_anchor: DefiningAnchor::Error,
             considering_regions: true,
             fresh_typeck_results: None,
+            normalize_fn_sig_for_diagnostic: None,
         }
     }
 }
@@ -582,6 +604,14 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
         self
     }
 
+    pub fn with_normalize_fn_sig_for_diagnostic(
+        mut self,
+        fun: Lrc<dyn Fn(&InferCtxt<'_, 'tcx>, ty::PolyFnSig<'tcx>) -> ty::PolyFnSig<'tcx>>,
+    ) -> Self {
+        self.normalize_fn_sig_for_diagnostic = Some(fun);
+        self
+    }
+
     /// Given a canonical value `C` as a starting point, create an
     /// inference context that contains each of the bound values
     /// within instantiated as a fresh variable. The `f` closure is
@@ -611,6 +641,7 @@ impl<'tcx> 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 {
@@ -624,11 +655,14 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
             evaluation_cache: Default::default(),
             reported_trait_errors: Default::default(),
             reported_closure_mismatch: Default::default(),
-            tainted_by_errors_flag: Cell::new(false),
+            tainted_by_errors: Cell::new(None),
             err_count_on_creation: tcx.sess.err_count(),
             in_snapshot: Cell::new(false),
             skip_leak_check: Cell::new(false),
             universe: Cell::new(ty::UniverseIndex::ROOT),
+            normalize_fn_sig_for_diagnostic: normalize_fn_sig_for_diagnostic
+                .as_ref()
+                .map(|f| f.clone()),
         })
     }
 }
@@ -988,7 +1022,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         cause: &ObligationCause<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
         predicate: ty::PolyCoercePredicate<'tcx>,
-    ) -> Option<InferResult<'tcx, ()>> {
+    ) -> Result<InferResult<'tcx, ()>, (TyVid, TyVid)> {
         let subtype_predicate = predicate.map_bound(|p| ty::SubtypePredicate {
             a_is_expected: false, // when coercing from `a` to `b`, `b` is expected
             a: p.a,
@@ -1002,7 +1036,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         cause: &ObligationCause<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
         predicate: ty::PolySubtypePredicate<'tcx>,
-    ) -> Option<InferResult<'tcx, ()>> {
+    ) -> Result<InferResult<'tcx, ()>, (TyVid, TyVid)> {
         // Check for two unresolved inference variables, in which case we can
         // make no progress. This is partly a micro-optimization, but it's
         // also an opportunity to "sub-unify" the variables. This isn't
@@ -1021,12 +1055,12 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         match (r_a.kind(), r_b.kind()) {
             (&ty::Infer(ty::TyVar(a_vid)), &ty::Infer(ty::TyVar(b_vid))) => {
                 self.inner.borrow_mut().type_variables().sub(a_vid, b_vid);
-                return None;
+                return Err((a_vid, b_vid));
             }
             _ => {}
         }
 
-        Some(self.commit_if_ok(|_snapshot| {
+        Ok(self.commit_if_ok(|_snapshot| {
             let ty::SubtypePredicate { a_is_expected, a, b } =
                 self.replace_bound_vars_with_placeholders(predicate);
 
@@ -1227,23 +1261,25 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     pub fn is_tainted_by_errors(&self) -> bool {
         debug!(
             "is_tainted_by_errors(err_count={}, err_count_on_creation={}, \
-             tainted_by_errors_flag={})",
+             tainted_by_errors={})",
             self.tcx.sess.err_count(),
             self.err_count_on_creation,
-            self.tainted_by_errors_flag.get()
+            self.tainted_by_errors.get().is_some()
         );
 
         if self.tcx.sess.err_count() > self.err_count_on_creation {
             return true; // errors reported since this infcx was made
         }
-        self.tainted_by_errors_flag.get()
+        self.tainted_by_errors.get().is_some()
     }
 
     /// Set the "tainted by errors" flag to true. We call this when we
     /// observe an error from a prior pass.
     pub fn set_tainted_by_errors(&self) {
         debug!("set_tainted_by_errors()");
-        self.tainted_by_errors_flag.set(true)
+        self.tainted_by_errors.set(Some(
+            self.tcx.sess.delay_span_bug(DUMMY_SP, "`InferCtxt` incorrectly tainted by errors"),
+        ));
     }
 
     pub fn skip_region_resolution(&self) {
@@ -1313,7 +1349,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     /// `resolve_vars_if_possible` as well as `fully_resolve`.
     ///
     /// Make sure to call [`InferCtxt::process_registered_region_obligations`]
-    /// first, or preferrably use [`InferCtxt::check_region_obligations_and_report_errors`]
+    /// first, or preferably use [`InferCtxt::check_region_obligations_and_report_errors`]
     /// to do both of these operations together.
     pub fn resolve_regions_and_report_errors(
         &self,
@@ -1527,8 +1563,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         actual: Ty<'tcx>,
         err: TypeError<'tcx>,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
-        let trace = TypeTrace::types(cause, true, expected, actual);
-        self.report_and_explain_type_error(trace, &err)
+        self.report_and_explain_type_error(TypeTrace::types(cause, true, expected, actual), err)
     }
 
     pub fn report_mismatched_consts(
@@ -1538,8 +1573,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         actual: ty::Const<'tcx>,
         err: TypeError<'tcx>,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
-        let trace = TypeTrace::consts(cause, true, expected, actual);
-        self.report_and_explain_type_error(trace, &err)
+        self.report_and_explain_type_error(TypeTrace::consts(cause, true, expected, actual), err)
     }
 
     pub fn replace_bound_vars_with_fresh_vars<T>(
@@ -1656,7 +1690,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     pub fn try_const_eval_resolve(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        unevaluated: ty::Unevaluated<'tcx>,
+        unevaluated: ty::Unevaluated<'tcx, ()>,
         ty: Ty<'tcx>,
         span: Option<Span>,
     ) -> Result<ty::Const<'tcx>, ErrorHandled> {
@@ -1691,7 +1725,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     pub fn const_eval_resolve(
         &self,
         mut param_env: ty::ParamEnv<'tcx>,
-        unevaluated: ty::Unevaluated<'tcx>,
+        unevaluated: ty::Unevaluated<'tcx, ()>,
         span: Option<Span>,
     ) -> EvalToValTreeResult<'tcx> {
         let mut substs = self.resolve_vars_if_possible(unevaluated.substs);
@@ -1700,7 +1734,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         // Postpone the evaluation of constants whose substs depend on inference
         // variables
         if substs.has_infer_types_or_consts() {
-            let ac = AbstractConst::new(self.tcx, unevaluated.shrink());
+            let ac = AbstractConst::new(self.tcx, unevaluated);
             match ac {
                 Ok(None) => {
                     substs = InternalSubsts::identity_for_item(self.tcx, unevaluated.def.did);
@@ -1722,11 +1756,8 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         debug!(?param_env_erased);
         debug!(?substs_erased);
 
-        let unevaluated = ty::Unevaluated {
-            def: unevaluated.def,
-            substs: substs_erased,
-            promoted: unevaluated.promoted,
-        };
+        let unevaluated =
+            ty::Unevaluated { def: unevaluated.def, substs: substs_erased, promoted: () };
 
         // The return value is the evaluated value which doesn't contain any reference to inference
         // variables, thus we don't need to substitute back the original values.
@@ -1814,7 +1845,7 @@ impl<'tcx> TyOrConstInferVar<'tcx> {
 
     /// Tries to extract an inference variable from a type, returns `None`
     /// for types other than `ty::Infer(_)` (or `InferTy::Fresh*`).
-    pub fn maybe_from_ty(ty: Ty<'tcx>) -> Option<Self> {
+    fn maybe_from_ty(ty: Ty<'tcx>) -> Option<Self> {
         match *ty.kind() {
             ty::Infer(ty::TyVar(v)) => Some(TyOrConstInferVar::Ty(v)),
             ty::Infer(ty::IntVar(v)) => Some(TyOrConstInferVar::TyInt(v)),
@@ -1825,7 +1856,7 @@ impl<'tcx> TyOrConstInferVar<'tcx> {
 
     /// Tries to extract an inference variable from a constant, returns `None`
     /// for constants other than `ty::ConstKind::Infer(_)` (or `InferConst::Fresh`).
-    pub fn maybe_from_const(ct: ty::Const<'tcx>) -> Option<Self> {
+    fn maybe_from_const(ct: ty::Const<'tcx>) -> Option<Self> {
         match ct.kind() {
             ty::ConstKind::Infer(InferConst::Var(v)) => Some(TyOrConstInferVar::Const(v)),
             _ => None,
@@ -1937,6 +1968,18 @@ impl<'tcx> TypeTrace<'tcx> {
         }
     }
 
+    pub fn poly_trait_refs(
+        cause: &ObligationCause<'tcx>,
+        a_is_expected: bool,
+        a: ty::PolyTraitRef<'tcx>,
+        b: ty::PolyTraitRef<'tcx>,
+    ) -> TypeTrace<'tcx> {
+        TypeTrace {
+            cause: cause.clone(),
+            values: PolyTraitRefs(ExpectedFound::new(a_is_expected, a.into(), b.into())),
+        }
+    }
+
     pub fn consts(
         cause: &ObligationCause<'tcx>,
         a_is_expected: bool,
@@ -1962,6 +2005,7 @@ impl<'tcx> SubregionOrigin<'tcx> {
             DataBorrowed(_, a) => a,
             ReferenceOutlivesReferent(_, a) => a,
             CompareImplItemObligation { span, .. } => span,
+            AscribeUserTypeProvePredicate(span) => span,
             CheckAssociatedTypeBounds { ref parent, .. } => parent.span(),
         }
     }
@@ -1994,6 +2038,10 @@ impl<'tcx> SubregionOrigin<'tcx> {
                 parent: Box::new(default()),
             },
 
+            traits::ObligationCauseCode::AscribeUserTypeProvePredicate(span) => {
+                SubregionOrigin::AscribeUserTypeProvePredicate(span)
+            }
+
             _ => default(),
         }
     }
@@ -2015,16 +2063,6 @@ impl RegionVariableOrigin {
     }
 }
 
-impl<'tcx> fmt::Debug for RegionObligation<'tcx> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "RegionObligation(sub_region={:?}, sup_type={:?})",
-            self.sub_region, self.sup_type
-        )
-    }
-}
-
 /// Replaces substs that reference param or infer variables with suitable
 /// placeholders. This function is meant to remove these param and infer
 /// substs when they're not actually needed to evaluate a constant.