Fix ConstantKind::Ty codegen

Author: bjorn3

src/base.rs

@@ -917,7 +917,7 @@ pub(crate) fn codegen_operand<'tcx>(
             let cplace = codegen_place(fx, *place);
             cplace.to_cvalue(fx)
         }
-        Operand::Constant(const_) => crate::constant::codegen_constant(fx, const_),
+        Operand::Constant(const_) => crate::constant::codegen_constant_operand(fx, const_),
     }
 }
 

src/constant.rs

@@ -7,7 +7,6 @@ use rustc_middle::mir::interpret::{
 };
 use rustc_span::DUMMY_SP;
 
-use cranelift_codegen::ir::GlobalValueData;
 use cranelift_module::*;
 
 use crate::prelude::*;
@@ -81,53 +80,46 @@ pub(crate) fn codegen_tls_ref<'tcx>(
     CValue::by_val(tls_ptr, layout)
 }
 
-fn codegen_static_ref<'tcx>(
-    fx: &mut FunctionCx<'_, '_, 'tcx>,
-    def_id: DefId,
-    layout: TyAndLayout<'tcx>,
-) -> CPlace<'tcx> {
-    let data_id = data_id_for_static(fx.tcx, fx.module, def_id, false);
-    let local_data_id = fx.module.declare_data_in_func(data_id, &mut fx.bcx.func);
-    if fx.clif_comments.enabled() {
-        fx.add_comment(local_data_id, format!("{:?}", def_id));
-    }
-    let global_ptr = fx.bcx.ins().global_value(fx.pointer_type, local_data_id);
-    assert!(!layout.is_unsized(), "unsized statics aren't supported");
-    assert!(
-        matches!(
-            fx.bcx.func.global_values[local_data_id],
-            GlobalValueData::Symbol { tls: false, .. }
-        ),
-        "tls static referenced without Rvalue::ThreadLocalRef"
-    );
-    CPlace::for_ptr(crate::pointer::Pointer::new(global_ptr), layout)
-}
-
-pub(crate) fn codegen_constant<'tcx>(
+pub(crate) fn eval_mir_constant<'tcx>(
     fx: &mut FunctionCx<'_, '_, 'tcx>,
     constant: &Constant<'tcx>,
-) -> CValue<'tcx> {
-    let (const_val, ty) = match fx.monomorphize(constant.literal) {
-        ConstantKind::Ty(const_) => unreachable!("{:?}", const_),
-        ConstantKind::Unevaluated(mir::UnevaluatedConst { def, substs, promoted }, ty)
+) -> (ConstValue<'tcx>, Ty<'tcx>) {
+    let constant_kind = fx.monomorphize(constant.literal);
+    let uv = match constant_kind {
+        ConstantKind::Ty(const_) => match const_.kind() {
+            ty::ConstKind::Unevaluated(uv) => uv.expand(),
+            ty::ConstKind::Value(val) => {
+                return (fx.tcx.valtree_to_const_val((const_.ty(), val)), const_.ty());
+            }
+            err => span_bug!(
+                constant.span,
+                "encountered bad ConstKind after monomorphizing: {:?}",
+                err
+            ),
+        },
+        ConstantKind::Unevaluated(mir::UnevaluatedConst { def, .. }, _)
             if fx.tcx.is_static(def.did) =>
         {
-            assert!(substs.is_empty());
-            assert!(promoted.is_none());
-
-            return codegen_static_ref(fx, def.did, fx.layout_of(ty)).to_cvalue(fx);
-        }
-        ConstantKind::Unevaluated(unevaluated, ty) => {
-            match fx.tcx.const_eval_resolve(ParamEnv::reveal_all(), unevaluated, None) {
-                Ok(const_val) => (const_val, ty),
-                Err(_) => {
-                    span_bug!(constant.span, "erroneous constant not captured by required_consts");
-                }
-            }
+            span_bug!(constant.span, "MIR constant refers to static");
         }
-        ConstantKind::Val(val, ty) => (val, ty),
+        ConstantKind::Unevaluated(uv, _) => uv,
+        ConstantKind::Val(val, _) => return (val, constant_kind.ty()),
     };
 
+    (
+        fx.tcx.const_eval_resolve(ty::ParamEnv::reveal_all(), uv, None).unwrap_or_else(|_err| {
+            span_bug!(constant.span, "erroneous constant not captured by required_consts");
+        }),
+        constant_kind.ty(),
+    )
+}
+
+pub(crate) fn codegen_constant_operand<'tcx>(
+    fx: &mut FunctionCx<'_, '_, 'tcx>,
+    constant: &Constant<'tcx>,
+) -> CValue<'tcx> {
+    let (const_val, ty) = eval_mir_constant(fx, constant);
+
     codegen_const_value(fx, const_val, ty)
 }