Remove CastCheckResult since it's unused

compiler/rustc_hir_analysis/src/check/cast.rs

@@ -203,28 +203,8 @@ fn make_invalid_casting_error<'a, 'tcx>(
     )
 }
 
-pub enum CastCheckResult<'tcx> {
-    Ok,
-    Deferred(CastCheck<'tcx>),
-    Err(ErrorGuaranteed),
-}
-
-pub fn check_cast<'tcx>(
-    fcx: &FnCtxt<'_, 'tcx>,
-    expr: &'tcx hir::Expr<'tcx>,
-    expr_ty: Ty<'tcx>,
-    cast_ty: Ty<'tcx>,
-    cast_span: Span,
-    span: Span,
-) -> CastCheckResult<'tcx> {
-    match CastCheck::new(fcx, expr, expr_ty, cast_ty, cast_span, span) {
-        Ok(check) => CastCheckResult::Deferred(check),
-        Err(e) => CastCheckResult::Err(e),
-    }
-}
-
 impl<'a, 'tcx> CastCheck<'tcx> {
-    fn new(
+    pub fn new(
         fcx: &FnCtxt<'a, 'tcx>,
         expr: &'tcx hir::Expr<'tcx>,
         expr_ty: Ty<'tcx>,

compiler/rustc_hir_analysis/src/check/expr.rs

@@ -3,7 +3,7 @@
 //! See `mod.rs` for more context on type checking in general.
 
 use crate::astconv::AstConv as _;
-use crate::check::cast::{self, CastCheckResult};
+use crate::check::cast;
 use crate::check::coercion::CoerceMany;
 use crate::check::fatally_break_rust;
 use crate::check::method::SelfSource;
@@ -1270,9 +1270,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else {
             // Defer other checks until we're done type checking.
             let mut deferred_cast_checks = self.deferred_cast_checks.borrow_mut();
-            match cast::check_cast(self, e, t_expr, t_cast, t.span, expr.span) {
-                CastCheckResult::Ok => t_cast,
-                CastCheckResult::Deferred(cast_check) => {
+            match cast::CastCheck::new(self, e, t_expr, t_cast, t.span, expr.span) {
+                Ok(cast_check) => {
                     debug!(
                         "check_expr_cast: deferring cast from {:?} to {:?}: {:?}",
                         t_cast, t_expr, cast_check,
@@ -1280,7 +1279,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     deferred_cast_checks.push(cast_check);
                     t_cast
                 }
-                CastCheckResult::Err(ErrorGuaranteed { .. }) => self.tcx.ty_error(),
+                Err(_) => self.tcx.ty_error(),
             }
         }
     }

src/tools/clippy/clippy_lints/src/transmute/utils.rs

@@ -1,15 +1,16 @@
 use rustc_hir::Expr;
-use rustc_hir_analysis::check::{
-    cast::{self, CastCheckResult},
-    FnCtxt, Inherited,
-};
+use rustc_hir_analysis::check::{cast, FnCtxt, Inherited};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{cast::CastKind, Ty};
 use rustc_span::DUMMY_SP;
 
 // check if the component types of the transmuted collection and the result have different ABI,
 // size or alignment
-pub(super) fn is_layout_incompatible<'tcx>(cx: &LateContext<'tcx>, from: Ty<'tcx>, to: Ty<'tcx>) -> bool {
+pub(super) fn is_layout_incompatible<'tcx>(
+    cx: &LateContext<'tcx>,
+    from: Ty<'tcx>,
+    to: Ty<'tcx>,
+) -> bool {
     if let Ok(from) = cx.tcx.try_normalize_erasing_regions(cx.param_env, from)
         && let Ok(to) = cx.tcx.try_normalize_erasing_regions(cx.param_env, to)
         && let Ok(from_layout) = cx.tcx.layout_of(cx.param_env.and(from))
@@ -32,7 +33,9 @@ pub(super) fn can_be_expressed_as_pointer_cast<'tcx>(
     from_ty: Ty<'tcx>,
     to_ty: Ty<'tcx>,
 ) -> bool {
-    use CastKind::{AddrPtrCast, ArrayPtrCast, FnPtrAddrCast, FnPtrPtrCast, PtrAddrCast, PtrPtrCast};
+    use CastKind::{
+        AddrPtrCast, ArrayPtrCast, FnPtrAddrCast, FnPtrPtrCast, PtrAddrCast, PtrPtrCast,
+    };
     matches!(
         check_cast(cx, e, from_ty, to_ty),
         Some(PtrPtrCast | PtrAddrCast | AddrPtrCast | ArrayPtrCast | FnPtrPtrCast | FnPtrAddrCast)
@@ -43,7 +46,12 @@ pub(super) fn can_be_expressed_as_pointer_cast<'tcx>(
 /// the cast. In certain cases, including some invalid casts from array references
 /// to pointers, this may cause additional errors to be emitted and/or ICE error
 /// messages. This function will panic if that occurs.
-fn check_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> Option<CastKind> {
+fn check_cast<'tcx>(
+    cx: &LateContext<'tcx>,
+    e: &'tcx Expr<'_>,
+    from_ty: Ty<'tcx>,
+    to_ty: Ty<'tcx>,
+) -> Option<CastKind> {
     let hir_id = e.hir_id;
     let local_def_id = hir_id.owner.def_id;
 
@@ -51,12 +59,9 @@ fn check_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>
         let fn_ctxt = FnCtxt::new(&inherited, cx.param_env, hir_id);
 
         // If we already have errors, we can't be sure we can pointer cast.
-        assert!(
-            !fn_ctxt.errors_reported_since_creation(),
-            "Newly created FnCtxt contained errors"
-        );
+        assert!(!fn_ctxt.errors_reported_since_creation(), "Newly created FnCtxt contained errors");
 
-        if let CastCheckResult::Deferred(check) = cast::check_cast(
+        if let Ok(check) = cast::CastCheck::new(
             &fn_ctxt, e, from_ty, to_ty,
             // We won't show any error to the user, so we don't care what the span is here.
             DUMMY_SP, DUMMY_SP,