Rollup merge of #104359 - Nilstrieb:plus-one, r=fee1-dead

[rust.git] / compiler / rustc_hir_typeck / src / cast.rs

diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index d1dab0540be956087c2236fa649818272eb1c251..5e1e44dcb6d158d9d5321736ed46a1bd6ce50f24 100644 (file)
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -33,6 +33,7 @@
 use crate::type_error_struct;
 use rustc_errors::{struct_span_err, Applicability, DelayDm, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_hir as hir;
+use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::mir::Mutability;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::cast::{CastKind, CastTy};
@@ -67,7 +68,7 @@ pub struct CastCheck<'tcx> {
 /// The kind of pointer and associated metadata (thin, length or vtable) - we
 /// only allow casts between fat pointers if their metadata have the same
 /// kind.
-#[derive(Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, TypeVisitable, TypeFoldable)]
 enum PointerKind<'tcx> {
     /// No metadata attached, ie pointer to sized type or foreign type
     Thin,
@@ -76,11 +77,11 @@ enum PointerKind<'tcx> {
     /// Slice
     Length,
     /// The unsize info of this projection
-    OfProjection(&'tcx ty::ProjectionTy<'tcx>),
+    OfProjection(ty::ProjectionTy<'tcx>),
     /// The unsize info of this opaque ty
     OfOpaque(DefId, SubstsRef<'tcx>),
     /// The unsize info of this parameter
-    OfParam(&'tcx ty::ParamTy),
+    OfParam(ty::ParamTy),
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
@@ -94,10 +95,7 @@ fn pointer_kind(
         debug!("pointer_kind({:?}, {:?})", t, span);
 
         let t = self.resolve_vars_if_possible(t);
-
-        if let Some(reported) = t.error_reported() {
-            return Err(reported);
-        }
+        t.error_reported()?;
 
         if self.type_is_sized_modulo_regions(self.param_env, t, span) {
             return Ok(Some(PointerKind::Thin));
@@ -121,9 +119,9 @@ fn pointer_kind(
             // Pointers to foreign types are thin, despite being unsized
             ty::Foreign(..) => Some(PointerKind::Thin),
             // We should really try to normalize here.
-            ty::Projection(ref pi) => Some(PointerKind::OfProjection(pi)),
+            ty::Projection(pi) => Some(PointerKind::OfProjection(pi)),
             ty::Opaque(def_id, substs) => Some(PointerKind::OfOpaque(def_id, substs)),
-            ty::Param(ref p) => Some(PointerKind::OfParam(p)),
+            ty::Param(p) => Some(PointerKind::OfParam(p)),
             // Insufficient type information.
             ty::Placeholder(..) | ty::Bound(..) | ty::Infer(_) => None,
 
@@ -222,8 +220,7 @@ pub fn new(
         // inference is more completely known.
         match cast_ty.kind() {
             ty::Dynamic(_, _, ty::Dyn) | ty::Slice(..) => {
-                let reported = check.report_cast_to_unsized_type(fcx);
-                Err(reported)
+                Err(check.report_cast_to_unsized_type(fcx))
             }
             _ => Ok(check),
         }
@@ -501,10 +498,9 @@ fn report_cast_error(&self, fcx: &FnCtxt<'a, 'tcx>, e: CastError) {
                         let ty = fcx.tcx.erase_regions(ty);
                         let expr_ty = fcx.resolve_vars_if_possible(self.expr_ty);
                         let expr_ty = fcx.tcx.erase_regions(expr_ty);
-                        let ty_params = fcx.tcx.mk_substs_trait(expr_ty, &[]);
                         if fcx
                             .infcx
-                            .type_implements_trait(from_trait, ty, ty_params, fcx.param_env)
+                            .type_implements_trait(from_trait, [ty, expr_ty], fcx.param_env)
                             .must_apply_modulo_regions()
                         {
                             label = false;
@@ -614,10 +610,11 @@ fn report_cast_error(&self, fcx: &FnCtxt<'a, 'tcx>, e: CastError) {
     }
 
     fn report_cast_to_unsized_type(&self, fcx: &FnCtxt<'a, 'tcx>) -> ErrorGuaranteed {
-        if let Some(reported) =
-            self.cast_ty.error_reported().or_else(|| self.expr_ty.error_reported())
-        {
-            return reported;
+        if let Err(err) = self.cast_ty.error_reported() {
+            return err;
+        }
+        if let Err(err) = self.expr_ty.error_reported() {
+            return err;
         }
 
         let tstr = fcx.ty_to_string(self.cast_ty);
@@ -912,7 +909,7 @@ fn check_ptr_ptr_cast(
         }
 
         // vtable kinds must match
-        if cast_kind == expr_kind {
+        if fcx.tcx.erase_regions(cast_kind) == fcx.tcx.erase_regions(expr_kind) {
             Ok(CastKind::PtrPtrCast)
         } else {
             Err(CastError::DifferingKinds)