Sync from rust debd22da66

src/abi/mod.rs

@@ -593,6 +593,7 @@ pub(crate) fn codegen_drop<'tcx>(
     fx: &mut FunctionCx<'_, '_, 'tcx>,
     source_info: mir::SourceInfo,
     drop_place: CPlace<'tcx>,
+    target: BasicBlock,
 ) {
     let ty = drop_place.layout().ty;
     let drop_instance = Instance::resolve_drop_in_place(fx.tcx, ty).polymorphize(fx.tcx);
@@ -620,6 +621,12 @@ pub(crate) fn codegen_drop<'tcx>(
                 let ptr = ptr.get_addr(fx);
                 let drop_fn = crate::vtable::drop_fn_of_obj(fx, vtable);
 
+                let is_null = fx.bcx.ins().icmp_imm(IntCC::Equal, drop_fn, 0);
+                let target_block = fx.get_block(target);
+                let continued = fx.bcx.create_block();
+                fx.bcx.ins().brif(is_null, target_block, &[], continued, &[]);
+                fx.bcx.switch_to_block(continued);
+
                 // FIXME(eddyb) perhaps move some of this logic into
                 // `Instance::resolve_drop_in_place`?
                 let virtual_drop = Instance {
@@ -659,6 +666,12 @@ pub(crate) fn codegen_drop<'tcx>(
                 let (data, vtable) = drop_place.to_cvalue(fx).dyn_star_force_data_on_stack(fx);
                 let drop_fn = crate::vtable::drop_fn_of_obj(fx, vtable);
 
+                let is_null = fx.bcx.ins().icmp_imm(IntCC::Equal, drop_fn, 0);
+                let target_block = fx.get_block(target);
+                let continued = fx.bcx.create_block();
+                fx.bcx.ins().brif(is_null, target_block, &[], continued, &[]);
+                fx.bcx.switch_to_block(continued);
+
                 let virtual_drop = Instance {
                     def: ty::InstanceDef::Virtual(drop_instance.def_id(), 0),
                     args: drop_instance.args,
@@ -697,4 +710,7 @@ pub(crate) fn codegen_drop<'tcx>(
             }
         }
     }
+
+    let target_block = fx.get_block(target);
+    fx.bcx.ins().jump(target_block, &[]);
 }

src/base.rs

@@ -548,10 +548,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
             }
             TerminatorKind::Drop { place, target, unwind: _, replace: _ } => {
                 let drop_place = codegen_place(fx, *place);
-                crate::abi::codegen_drop(fx, source_info, drop_place);
-
-                let target_block = fx.get_block(*target);
-                fx.bcx.ins().jump(target_block, &[]);
+                crate::abi::codegen_drop(fx, source_info, drop_place, *target);
             }
         };
     }
@@ -619,22 +616,34 @@ fn codegen_stmt<'tcx>(
                 Rvalue::UnaryOp(un_op, ref operand) => {
                     let operand = codegen_operand(fx, operand);
                     let layout = operand.layout();
-                    let val = operand.load_scalar(fx);
                     let res = match un_op {
-                        UnOp::Not => match layout.ty.kind() {
-                            ty::Bool => {
-                                let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
-                                CValue::by_val(res, layout)
+                        UnOp::Not => {
+                            let val = operand.load_scalar(fx);
+                            match layout.ty.kind() {
+                                ty::Bool => {
+                                    let res = fx.bcx.ins().icmp_imm(IntCC::Equal, val, 0);
+                                    CValue::by_val(res, layout)
+                                }
+                                ty::Uint(_) | ty::Int(_) => {
+                                    CValue::by_val(fx.bcx.ins().bnot(val), layout)
+                                }
+                                _ => unreachable!("un op Not for {:?}", layout.ty),
                             }
-                            ty::Uint(_) | ty::Int(_) => {
-                                CValue::by_val(fx.bcx.ins().bnot(val), layout)
+                        }
+                        UnOp::Neg => {
+                            let val = operand.load_scalar(fx);
+                            match layout.ty.kind() {
+                                ty::Int(_) => CValue::by_val(fx.bcx.ins().ineg(val), layout),
+                                ty::Float(_) => CValue::by_val(fx.bcx.ins().fneg(val), layout),
+                                _ => unreachable!("un op Neg for {:?}", layout.ty),
                             }
-                            _ => unreachable!("un op Not for {:?}", layout.ty),
-                        },
-                        UnOp::Neg => match layout.ty.kind() {
-                            ty::Int(_) => CValue::by_val(fx.bcx.ins().ineg(val), layout),
-                            ty::Float(_) => CValue::by_val(fx.bcx.ins().fneg(val), layout),
-                            _ => unreachable!("un op Neg for {:?}", layout.ty),
+                        }
+                        UnOp::PtrMetadata => match layout.abi {
+                            Abi::Scalar(_) => CValue::zst(dest_layout),
+                            Abi::ScalarPair(_, _) => {
+                                CValue::by_val(operand.load_scalar_pair(fx).1, dest_layout)
+                            }
+                            _ => bug!("Unexpected `PtrToMetadata` operand: {operand:?}"),
                         },
                     };
                     lval.write_cvalue(fx, res);

src/constant.rs

@@ -100,7 +100,7 @@ pub(crate) fn codegen_const_value<'tcx>(
     assert!(layout.is_sized(), "unsized const value");
 
     if layout.is_zst() {
-        return CValue::by_ref(crate::Pointer::dangling(layout.align.pref), layout);
+        return CValue::zst(layout);
     }
 
     match const_val {

src/driver/aot.rs

@@ -200,7 +200,7 @@ fn produce_final_output_artifacts(
     // to get rid of it.
     for output_type in crate_output.outputs.keys() {
         match *output_type {
-            OutputType::Bitcode => {
+            OutputType::Bitcode | OutputType::ThinLinkBitcode => {
                 // Cranelift doesn't have bitcode
                 // user_wants_bitcode = true;
                 // // Copy to .bc, but always keep the .0.bc. There is a later

src/value_and_place.rs

@@ -95,6 +95,14 @@ pub(crate) fn by_val_pair(
         CValue(CValueInner::ByValPair(value, extra), layout)
     }
 
+    /// Create an instance of a ZST
+    ///
+    /// The is represented by a dangling pointer of suitable alignment.
+    pub(crate) fn zst(layout: TyAndLayout<'tcx>) -> CValue<'tcx> {
+        assert!(layout.is_zst());
+        CValue::by_ref(crate::Pointer::dangling(layout.align.pref), layout)
+    }
+
     pub(crate) fn layout(&self) -> TyAndLayout<'tcx> {
         self.1
     }