const: don't ICE when encountering a mutable ref to immutable memory

1 files changed, 2 insertions, 8 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 469af35ec1b..ca38f779256 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -14,6 +14,7 @@ use hir::def::DefKind;
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
+use rustc_middle::bug;
 use rustc_middle::mir::interpret::ValidationErrorKind::{self, *};
 use rustc_middle::mir::interpret::{
     alloc_range, ExpectedKind, InterpError, InvalidMetaKind, Misalignment, PointerKind, Provenance,
@@ -21,7 +22,6 @@ use rustc_middle::mir::interpret::{
 };
 use rustc_middle::ty::layout::{LayoutCx, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Ty, TyCtxt};
-use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_target::abi::{
     Abi, FieldIdx, FieldsShape, Scalar as ScalarAbi, Size, VariantIdx, Variants, WrappingRange,
@@ -617,13 +617,7 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValidityVisitor<'rt, 'tcx, M> {
                         if ptr_expected_mutbl == Mutability::Mut
                             && alloc_actual_mutbl == Mutability::Not
                         {
-                            if !self.ecx.tcx.sess.opts.unstable_opts.unleash_the_miri_inside_of_you
-                            {
-                                span_bug!(
-                                    self.ecx.tcx.span,
-                                    "the static const safety checks accepted mutable references they should not have accepted"
-                                );
-                            }
+                            // This can actually occur with transmutes.
                             throw_validation_failure!(self.path, MutableRefToImmutable);
                         }
                         // In a const, everything must be completely immutable.