Refactor unwind from Option to a new enum

39 files changed, 328 insertions, 250 deletions

diff --git a/compiler/rustc_borrowck/src/diagnostics/find_use.rs b/compiler/rustc_borrowck/src/diagnostics/find_use.rs
index fd1fda2ee4b..e2d04324f3b 100644
--- a/compiler/rustc_borrowck/src/diagnostics/find_use.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/find_use.rs
@@ -11,7 +11,7 @@ use crate::{
 };
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_middle::mir::visit::{MirVisitable, PlaceContext, Visitor};
-use rustc_middle::mir::{Body, Local, Location};
+use rustc_middle::mir::{self, Body, Local, Location};
 use rustc_middle::ty::{RegionVid, TyCtxt};
 
 pub(crate) fn find<'tcx>(
@@ -70,7 +70,10 @@ impl<'cx, 'tcx> UseFinder<'cx, 'tcx> {
                             block_data
                                 .terminator()
                                 .successors()
-                                .filter(|&bb| Some(&Some(bb)) != block_data.terminator().unwind())
+                                .filter(|&bb| {
+                                    Some(&mir::UnwindAction::Cleanup(bb))
+                                        != block_data.terminator().unwind()
+                                })
                                 .map(|bb| Location { statement_index: 0, block: bb }),
                         );
                     }
diff --git a/compiler/rustc_borrowck/src/invalidation.rs b/compiler/rustc_borrowck/src/invalidation.rs
index a71c4163286..f69b35549b4 100644
--- a/compiler/rustc_borrowck/src/invalidation.rs
+++ b/compiler/rustc_borrowck/src/invalidation.rs
@@ -125,7 +125,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                 args,
                 destination,
                 target: _,
-                cleanup: _,
+                unwind: _,
                 from_hir_call: _,
                 fn_span: _,
             } => {
@@ -135,7 +135,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                 }
                 self.mutate_place(location, *destination, Deep);
             }
-            TerminatorKind::Assert { cond, expected: _, msg, target: _, cleanup: _ } => {
+            TerminatorKind::Assert { cond, expected: _, msg, target: _, unwind: _ } => {
                 self.consume_operand(location, cond);
                 use rustc_middle::mir::AssertKind;
                 if let AssertKind::BoundsCheck { len, index } = msg {
@@ -173,7 +173,7 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> {
                 options: _,
                 line_spans: _,
                 destination: _,
-                cleanup: _,
+                unwind: _,
             } => {
                 for op in operands {
                     match op {
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 1d4d1406239..4787b0ea4e9 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -740,7 +740,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
                 args,
                 destination,
                 target: _,
-                cleanup: _,
+                unwind: _,
                 from_hir_call: _,
                 fn_span: _,
             } => {
@@ -750,7 +750,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
                 }
                 self.mutate_place(loc, (*destination, span), Deep, flow_state);
             }
-            TerminatorKind::Assert { cond, expected: _, msg, target: _, cleanup: _ } => {
+            TerminatorKind::Assert { cond, expected: _, msg, target: _, unwind: _ } => {
                 self.consume_operand(loc, (cond, span), flow_state);
                 use rustc_middle::mir::AssertKind;
                 if let AssertKind::BoundsCheck { len, index } = msg {
@@ -770,7 +770,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
                 options: _,
                 line_spans: _,
                 destination: _,
-                cleanup: _,
+                unwind: _,
             } => {
                 for op in operands {
                     match op {
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 2fc4e32ecb2..10332c6d9b5 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -1610,20 +1610,20 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
             TerminatorKind::Unreachable => {}
             TerminatorKind::Drop { target, unwind, .. }
-            | TerminatorKind::Assert { target, cleanup: unwind, .. } => {
+            | TerminatorKind::Assert { target, unwind, .. } => {
                 self.assert_iscleanup(body, block_data, target, is_cleanup);
-                if let Some(unwind) = unwind {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     if is_cleanup {
                         span_mirbug!(self, block_data, "unwind on cleanup block")
                     }
                     self.assert_iscleanup(body, block_data, unwind, true);
                 }
             }
-            TerminatorKind::Call { ref target, cleanup, .. } => {
+            TerminatorKind::Call { ref target, unwind, .. } => {
                 if let &Some(target) = target {
                     self.assert_iscleanup(body, block_data, target, is_cleanup);
                 }
-                if let Some(cleanup) = cleanup {
+                if let UnwindAction::Cleanup(cleanup) = unwind {
                     if is_cleanup {
                         span_mirbug!(self, block_data, "cleanup on cleanup block")
                     }
@@ -1636,18 +1636,18 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
             TerminatorKind::FalseUnwind { real_target, unwind } => {
                 self.assert_iscleanup(body, block_data, real_target, is_cleanup);
-                if let Some(unwind) = unwind {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     if is_cleanup {
                         span_mirbug!(self, block_data, "cleanup in cleanup block via false unwind");
                     }
                     self.assert_iscleanup(body, block_data, unwind, true);
                 }
             }
-            TerminatorKind::InlineAsm { destination, cleanup, .. } => {
+            TerminatorKind::InlineAsm { destination, unwind, .. } => {
                 if let Some(target) = destination {
                     self.assert_iscleanup(body, block_data, target, is_cleanup);
                 }
-                if let Some(cleanup) = cleanup {
+                if let UnwindAction::Cleanup(cleanup) = unwind {
                     if is_cleanup {
                         span_mirbug!(self, block_data, "cleanup on cleanup block")
                     }
diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
index 2630f02e6eb..94413318492 100644
--- a/compiler/rustc_codegen_cranelift/src/base.rs
+++ b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -345,7 +345,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
             TerminatorKind::Return => {
                 crate::abi::codegen_return(fx);
             }
-            TerminatorKind::Assert { cond, expected, msg, target, cleanup: _ } => {
+            TerminatorKind::Assert { cond, expected, msg, target, unwind: _ } => {
                 if !fx.tcx.sess.overflow_checks() && msg.is_optional_overflow_check() {
                     let target = fx.get_block(*target);
                     fx.bcx.ins().jump(target, &[]);
@@ -450,7 +450,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
                 destination,
                 target,
                 fn_span,
-                cleanup: _,
+                unwind: _,
                 from_hir_call: _,
             } => {
                 fx.tcx.prof.generic_activity("codegen call").run(|| {
@@ -470,7 +470,7 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
                 options,
                 destination,
                 line_spans: _,
-                cleanup: _,
+                unwind: _,
             } => {
                 if options.contains(InlineAsmOptions::MAY_UNWIND) {
                     fx.tcx.sess.span_fatal(
diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
index dcf533dc39c..7d1c80ba88f 100644
--- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
@@ -292,11 +292,11 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
                 | TerminatorKind::Yield { .. }
                 | TerminatorKind::FalseEdge { .. }
                 | TerminatorKind::FalseUnwind { .. } => { /* nothing to do */ }
-                TerminatorKind::Call { cleanup: unwind, .. }
-                | TerminatorKind::InlineAsm { cleanup: unwind, .. }
-                | TerminatorKind::Assert { cleanup: unwind, .. }
+                TerminatorKind::Call { unwind, .. }
+                | TerminatorKind::InlineAsm { unwind, .. }
+                | TerminatorKind::Assert { unwind, .. }
                 | TerminatorKind::Drop { unwind, .. } => {
-                    if let Some(unwind) = unwind {
+                    if let mir::UnwindAction::Cleanup(unwind) = unwind {
                         debug!(
                             "cleanup_kinds: {:?}/{:?} registering {:?} as funclet",
                             bb, data, unwind
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index c086d1b7f5a..a6891a8ff2f 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -156,7 +156,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         fn_ptr: Bx::Value,
         llargs: &[Bx::Value],
         destination: Option<(ReturnDest<'tcx, Bx::Value>, mir::BasicBlock)>,
-        cleanup: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         copied_constant_arguments: &[PlaceRef<'tcx, <Bx as BackendTypes>::Value>],
         mergeable_succ: bool,
     ) -> MergingSucc {
@@ -164,6 +164,10 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         // do an invoke, otherwise do a call.
         let fn_ty = bx.fn_decl_backend_type(&fn_abi);
 
+        let cleanup = match unwind {
+            mir::UnwindAction::Cleanup(cleanup) => Some(cleanup),
+            mir::UnwindAction::Continue => None,
+        };
         let unwind_block = if let Some(cleanup) = cleanup.filter(|_| fn_abi.can_unwind) {
             Some(self.llbb_with_cleanup(fx, cleanup))
         } else if fx.mir[self.bb].is_cleanup
@@ -244,11 +248,11 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         options: InlineAsmOptions,
         line_spans: &[Span],
         destination: Option<mir::BasicBlock>,
-        cleanup: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         instance: Instance<'_>,
         mergeable_succ: bool,
     ) -> MergingSucc {
-        if let Some(cleanup) = cleanup {
+        if let mir::UnwindAction::Cleanup(cleanup) = unwind {
             let ret_llbb = if let Some(target) = destination {
                 fx.llbb(target)
             } else {
@@ -431,7 +435,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         bx: &mut Bx,
         location: mir::Place<'tcx>,
         target: mir::BasicBlock,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         mergeable_succ: bool,
     ) -> MergingSucc {
         let ty = location.ty(self.mir, bx.tcx()).ty;
@@ -552,7 +556,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         expected: bool,
         msg: &mir::AssertMessage<'tcx>,
         target: mir::BasicBlock,
-        cleanup: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         mergeable_succ: bool,
     ) -> MergingSucc {
         let span = terminator.source_info.span;
@@ -618,7 +622,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let (fn_abi, llfn) = common::build_langcall(bx, Some(span), lang_item);
 
         // Codegen the actual panic invoke/call.
-        let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &args, None, cleanup, &[], false);
+        let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &args, None, unwind, &[], false);
         assert_eq!(merging_succ, MergingSucc::False);
         MergingSucc::False
     }
@@ -636,7 +640,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let (fn_abi, llfn) = common::build_langcall(bx, Some(span), LangItem::PanicCannotUnwind);
 
         // Codegen the actual panic invoke/call.
-        let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &[], None, None, &[], false);
+        let merging_succ = helper.do_call(self, bx, fn_abi, llfn, &[], None, mir::UnwindAction::Continue, &[], false);
         assert_eq!(merging_succ, MergingSucc::False);
     }
 
@@ -649,7 +653,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         instance: Option<Instance<'tcx>>,
         source_info: mir::SourceInfo,
         target: Option<mir::BasicBlock>,
-        cleanup: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         mergeable_succ: bool,
     ) -> Option<MergingSucc> {
         // Emit a panic or a no-op for `assert_*` intrinsics.
@@ -696,7 +700,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     llfn,
                     &[msg.0, msg.1],
                     target.as_ref().map(|bb| (ReturnDest::Nothing, *bb)),
-                    cleanup,
+                    unwind,
                     &[],
                     mergeable_succ,
                 )
@@ -719,7 +723,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         args: &[mir::Operand<'tcx>],
         destination: mir::Place<'tcx>,
         target: Option<mir::BasicBlock>,
-        cleanup: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         fn_span: Span,
         mergeable_succ: bool,
     ) -> MergingSucc {
@@ -783,7 +787,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             instance,
             source_info,
             target,
-            cleanup,
+            unwind,
             mergeable_succ,
         ) {
             return merging_succ;
@@ -1064,7 +1068,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 fn_ptr,
                 &llargs,
                 target.as_ref().map(|&target| (ret_dest, target)),
-                cleanup,
+                unwind,
                 &copied_constant_arguments,
                 false,
             );
@@ -1084,7 +1088,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             fn_ptr,
             &llargs,
             target.as_ref().map(|&target| (ret_dest, target)),
-            cleanup,
+            unwind,
             &copied_constant_arguments,
             mergeable_succ,
         )
@@ -1100,7 +1104,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         options: ast::InlineAsmOptions,
         line_spans: &[Span],
         destination: Option<mir::BasicBlock>,
-        cleanup: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
         instance: Instance<'_>,
         mergeable_succ: bool,
     ) -> MergingSucc {
@@ -1164,7 +1168,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             options,
             line_spans,
             destination,
-            cleanup,
+            unwind,
             instance,
             mergeable_succ,
         )
@@ -1274,7 +1278,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 self.codegen_drop_terminator(helper, bx, place, target, unwind, mergeable_succ())
             }
 
-            mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, cleanup } => self
+            mir::TerminatorKind::Assert { ref cond, expected, ref msg, target, unwind } => self
                 .codegen_assert_terminator(
                     helper,
                     bx,
@@ -1283,7 +1287,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     expected,
                     msg,
                     target,
-                    cleanup,
+                    unwind,
                     mergeable_succ(),
                 ),
 
@@ -1292,7 +1296,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 ref args,
                 destination,
                 target,
-                cleanup,
+                unwind,
                 from_hir_call: _,
                 fn_span,
             } => self.codegen_call_terminator(
@@ -1303,7 +1307,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 args,
                 destination,
                 target,
-                cleanup,
+                unwind,
                 fn_span,
                 mergeable_succ(),
             ),
@@ -1320,7 +1324,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 options,
                 line_spans,
                 destination,
-                cleanup,
+                unwind,
             } => self.codegen_asm_terminator(
                 helper,
                 bx,
@@ -1330,7 +1334,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 options,
                 line_spans,
                 destination,
-                cleanup,
+                unwind,
                 self.instance,
                 mergeable_succ(),
             ),
diff --git a/compiler/rustc_const_eval/src/const_eval/machine.rs b/compiler/rustc_const_eval/src/const_eval/machine.rs
index c87ea18af4f..5fd99a9a84a 100644
--- a/compiler/rustc_const_eval/src/const_eval/machine.rs
+++ b/compiler/rustc_const_eval/src/const_eval/machine.rs
@@ -526,7 +526,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for CompileTimeInterpreter<'mir,
     fn assert_panic(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
         msg: &AssertMessage<'tcx>,
-        _unwind: Option<mir::BasicBlock>,
+        _unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         use rustc_middle::mir::AssertKind::*;
         // Convert `AssertKind<Operand>` to `AssertKind<Scalar>`.
diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs
index aca68dc454b..ca4da29ebbd 100644
--- a/compiler/rustc_const_eval/src/interpret/machine.rs
+++ b/compiler/rustc_const_eval/src/interpret/machine.rs
@@ -215,7 +215,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
     fn assert_panic(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
         msg: &mir::AssertMessage<'tcx>,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx>;
 
     /// Called to evaluate `Abort` MIR terminator.
diff --git a/compiler/rustc_const_eval/src/interpret/terminator.rs b/compiler/rustc_const_eval/src/interpret/terminator.rs
index 2d9fee9852c..2546423d4cc 100644
--- a/compiler/rustc_const_eval/src/interpret/terminator.rs
+++ b/compiler/rustc_const_eval/src/interpret/terminator.rs
@@ -60,7 +60,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 ref args,
                 destination,
                 target,
-                ref cleanup,
+                ref unwind,
                 from_hir_call: _,
                 fn_span: _,
             } => {
@@ -106,9 +106,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     with_caller_location,
                     &destination,
                     target,
-                    match (cleanup, fn_abi.can_unwind) {
-                        (Some(cleanup), true) => StackPopUnwind::Cleanup(*cleanup),
-                        (None, true) => StackPopUnwind::Skip,
+                    match (unwind, fn_abi.can_unwind) {
+                        (mir::UnwindAction::Cleanup(cleanup), true) => {
+                            StackPopUnwind::Cleanup(*cleanup)
+                        }
+                        (mir::UnwindAction::Continue, true) => StackPopUnwind::Skip,
                         (_, false) => StackPopUnwind::NotAllowed,
                     },
                 )?;
@@ -137,14 +139,14 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 self.drop_in_place(&place, instance, target, unwind)?;
             }
 
-            Assert { ref cond, expected, ref msg, target, cleanup } => {
+            Assert { ref cond, expected, ref msg, target, unwind } => {
                 let ignored =
                     M::ignore_optional_overflow_checks(self) && msg.is_optional_overflow_check();
                 let cond_val = self.read_scalar(&self.eval_operand(cond, None)?)?.to_bool()?;
                 if ignored || expected == cond_val {
                     self.go_to_block(target);
                 } else {
-                    M::assert_panic(self, msg, cleanup)?;
+                    M::assert_panic(self, msg, unwind)?;
                 }
             }
 
@@ -676,7 +678,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         place: &PlaceTy<'tcx, M::Provenance>,
         instance: ty::Instance<'tcx>,
         target: mir::BasicBlock,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         trace!("drop_in_place: {:?},\n  {:?}, {:?}", *place, place.layout.ty, instance);
         // We take the address of the object. This may well be unaligned, which is fine
@@ -718,8 +720,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             &ret.into(),
             Some(target),
             match unwind {
-                Some(cleanup) => StackPopUnwind::Cleanup(cleanup),
-                None => StackPopUnwind::Skip,
+                mir::UnwindAction::Cleanup(cleanup) => StackPopUnwind::Cleanup(cleanup),
+                mir::UnwindAction::Continue => StackPopUnwind::Skip,
             },
         )
     }
diff --git a/compiler/rustc_const_eval/src/transform/promote_consts.rs b/compiler/rustc_const_eval/src/transform/promote_consts.rs
index 6774e5a5837..7919aed097a 100644
--- a/compiler/rustc_const_eval/src/transform/promote_consts.rs
+++ b/compiler/rustc_const_eval/src/transform/promote_consts.rs
@@ -807,7 +807,7 @@ impl<'a, 'tcx> Promoter<'a, 'tcx> {
                         kind: TerminatorKind::Call {
                             func,
                             args,
-                            cleanup: None,
+                            unwind: UnwindAction::Continue,
                             destination: Place::from(new_temp),
                             target: Some(new_target),
                             from_hir_call,
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs
index e798c9d236e..be840ef6f7f 100644
--- a/compiler/rustc_const_eval/src/transform/validate.rs
+++ b/compiler/rustc_const_eval/src/transform/validate.rs
@@ -10,7 +10,7 @@ use rustc_middle::mir::{
     traversal, BasicBlock, BinOp, Body, BorrowKind, CastKind, CopyNonOverlapping, Local, Location,
     MirPass, MirPhase, NonDivergingIntrinsic, Operand, Place, PlaceElem, PlaceRef, ProjectionElem,
     RetagKind, RuntimePhase, Rvalue, SourceScope, Statement, StatementKind, Terminator,
-    TerminatorKind, UnOp, VarDebugInfo, VarDebugInfoContents, START_BLOCK,
+    TerminatorKind, UnOp, UnwindAction, VarDebugInfo, VarDebugInfoContents, START_BLOCK,
 };
 use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
 use rustc_mir_dataflow::impls::MaybeStorageLive;
@@ -902,11 +902,11 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             }
             TerminatorKind::Drop { target, unwind, .. } => {
                 self.check_edge(location, *target, EdgeKind::Normal);
-                if let Some(unwind) = unwind {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     self.check_edge(location, *unwind, EdgeKind::Unwind);
                 }
             }
-            TerminatorKind::Call { func, args, destination, target, cleanup, .. } => {
+            TerminatorKind::Call { func, args, destination, target, unwind, .. } => {
                 let func_ty = func.ty(&self.body.local_decls, self.tcx);
                 match func_ty.kind() {
                     ty::FnPtr(..) | ty::FnDef(..) => {}
@@ -918,7 +918,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 if let Some(target) = target {
                     self.check_edge(location, *target, EdgeKind::Normal);
                 }
-                if let Some(cleanup) = cleanup {
+                if let UnwindAction::Cleanup(cleanup) = unwind {
                     self.check_edge(location, *cleanup, EdgeKind::Unwind);
                 }
 
@@ -946,7 +946,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     );
                 }
             }
-            TerminatorKind::Assert { cond, target, cleanup, .. } => {
+            TerminatorKind::Assert { cond, target, unwind, .. } => {
                 let cond_ty = cond.ty(&self.body.local_decls, self.tcx);
                 if cond_ty != self.tcx.types.bool {
                     self.fail(
@@ -958,7 +958,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     );
                 }
                 self.check_edge(location, *target, EdgeKind::Normal);
-                if let Some(cleanup) = cleanup {
+                if let UnwindAction::Cleanup(cleanup) = unwind {
                     self.check_edge(location, *cleanup, EdgeKind::Unwind);
                 }
             }
@@ -992,15 +992,15 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     );
                 }
                 self.check_edge(location, *real_target, EdgeKind::Normal);
-                if let Some(unwind) = unwind {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     self.check_edge(location, *unwind, EdgeKind::Unwind);
                 }
             }
-            TerminatorKind::InlineAsm { destination, cleanup, .. } => {
+            TerminatorKind::InlineAsm { destination, unwind, .. } => {
                 if let Some(destination) = destination {
                     self.check_edge(location, *destination, EdgeKind::Normal);
                 }
-                if let Some(cleanup) = cleanup {
+                if let UnwindAction::Cleanup(cleanup) = unwind {
                     self.check_edge(location, *cleanup, EdgeKind::Unwind);
                 }
             }
diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs
index cc35e6106e2..c2a12bb3b66 100644
--- a/compiler/rustc_middle/src/mir/syntax.rs
+++ b/compiler/rustc_middle/src/mir/syntax.rs
@@ -515,14 +515,14 @@ pub struct CopyNonOverlapping<'tcx> {
 ///
 /// A note on unwinding: Panics may occur during the execution of some terminators. Depending on the
 /// `-C panic` flag, this may either cause the program to abort or the call stack to unwind. Such
-/// terminators have a `cleanup: Option<BasicBlock>` field on them. If stack unwinding occurs, then
-/// once the current function is reached, execution continues at the given basic block, if any. If
-/// `cleanup` is `None` then no cleanup is performed, and the stack continues unwinding. This is
-/// equivalent to the execution of a `Resume` terminator.
+/// terminators have a `unwind: UnwindAction` field on them. If stack unwinding occurs, then
+/// once the current function is reached, an action will be taken based on the `unwind` field.
+/// If the action is `Cleanup`, then the execution continues at the given basic block. If the
+/// action is `Continue` then no cleanup is performed, and the stack continues unwinding.
 ///
-/// The basic block pointed to by a `cleanup` field must have its `cleanup` flag set. `cleanup`
-/// basic blocks have a couple restrictions:
-///  1. All `cleanup` fields in them must be `None`.
+/// The basic block pointed to by a `Cleanup` unwind action must have its `cleanup` flag set.
+/// `cleanup` basic blocks have a couple restrictions:
+///  1. All `unwind` fields in them must be `UnwindAction::Continue`.
 ///  2. `Return` terminators are not allowed in them. `Abort` and `Unwind` terminators are.
 ///  3. All other basic blocks (in the current body) that are reachable from `cleanup` basic blocks
 ///     must also be `cleanup`. This is a part of the type system and checked statically, so it is
@@ -604,7 +604,7 @@ pub enum TerminatorKind<'tcx> {
     /// > The drop glue is executed if, among all statements executed within this `Body`, an assignment to
     /// > the place or one of its "parents" occurred more recently than a move out of it. This does not
     /// > consider indirect assignments.
-    Drop { place: Place<'tcx>, target: BasicBlock, unwind: Option<BasicBlock> },
+    Drop { place: Place<'tcx>, target: BasicBlock, unwind: UnwindAction },
 
     /// Roughly speaking, evaluates the `func` operand and the arguments, and starts execution of
     /// the referred to function. The operand types must match the argument types of the function.
@@ -628,8 +628,8 @@ pub enum TerminatorKind<'tcx> {
         destination: Place<'tcx>,
         /// Where to go after this call returns. If none, the call necessarily diverges.
         target: Option<BasicBlock>,
-        /// Cleanups to be done if the call unwinds.
-        cleanup: Option<BasicBlock>,
+        /// Action to be taken if the call unwinds.
+        unwind: UnwindAction,
         /// `true` if this is from a call in HIR rather than from an overloaded
         /// operator. True for overloaded function call.
         from_hir_call: bool,
@@ -654,7 +654,7 @@ pub enum TerminatorKind<'tcx> {
         expected: bool,
         msg: AssertMessage<'tcx>,
         target: BasicBlock,
-        cleanup: Option<BasicBlock>,
+        unwind: UnwindAction,
     },
 
     /// Marks a suspend point.
@@ -720,9 +720,10 @@ pub enum TerminatorKind<'tcx> {
         /// in practice, but in order to avoid fragility we want to always
         /// consider it in borrowck. We don't want to accept programs which
         /// pass borrowck only when `panic=abort` or some assertions are disabled
-        /// due to release vs. debug mode builds. This needs to be an `Option` because
+        /// due to release vs. debug mode builds.
+        /// This field does not necessary have to be `UnwindAction::Cleanup` because
         /// of the `remove_noop_landing_pads` and `abort_unwinding_calls` passes.
-        unwind: Option<BasicBlock>,
+        unwind: UnwindAction,
     },
 
     /// Block ends with an inline assembly block. This is a terminator since
@@ -745,12 +746,22 @@ pub enum TerminatorKind<'tcx> {
         /// diverging (InlineAsmOptions::NORETURN).
         destination: Option<BasicBlock>,
 
-        /// Cleanup to be done if the inline assembly unwinds. This is present
+        /// Action to be taken if the inline assembly unwinds. This is present
         /// if and only if InlineAsmOptions::MAY_UNWIND is set.
-        cleanup: Option<BasicBlock>,
+        unwind: UnwindAction,
     },
 }
 
+/// Action to be taken when a stack unwind happens.
+#[derive(Copy, Clone, Debug, PartialEq, TyEncodable, TyDecodable, Hash, HashStable)]
+#[derive(TypeFoldable, TypeVisitable)]
+pub enum UnwindAction {
+    // No action is to be taken. Continue unwinding.
+    Continue,
+    // Cleanups to be done.
+    Cleanup(BasicBlock),
+}
+
 /// Information about an assertion failure.
 #[derive(Clone, TyEncodable, TyDecodable, Hash, HashStable, PartialEq, TypeFoldable, TypeVisitable)]
 pub enum AssertKind<O> {
diff --git a/compiler/rustc_middle/src/mir/terminator.rs b/compiler/rustc_middle/src/mir/terminator.rs
index cd970270727..19aa01c12bd 100644
--- a/compiler/rustc_middle/src/mir/terminator.rs
+++ b/compiler/rustc_middle/src/mir/terminator.rs
@@ -1,6 +1,6 @@
 use smallvec::SmallVec;
 
-use super::{BasicBlock, InlineAsmOperand, Operand, SourceInfo, TerminatorKind};
+use super::{BasicBlock, InlineAsmOperand, Operand, SourceInfo, TerminatorKind, UnwindAction};
 use rustc_ast::InlineAsmTemplatePiece;
 pub use rustc_ast::Mutability;
 use rustc_macros::HashStable;
@@ -118,11 +118,11 @@ impl<'tcx> Terminator<'tcx> {
         self.kind.successors_mut()
     }
 
-    pub fn unwind(&self) -> Option<&Option<BasicBlock>> {
+    pub fn unwind(&self) -> Option<&UnwindAction> {
         self.kind.unwind()
     }
 
-    pub fn unwind_mut(&mut self) -> Option<&mut Option<BasicBlock>> {
+    pub fn unwind_mut(&mut self) -> Option<&mut UnwindAction> {
         self.kind.unwind_mut()
     }
 }
@@ -135,34 +135,34 @@ impl<'tcx> TerminatorKind<'tcx> {
     pub fn successors(&self) -> Successors<'_> {
         use self::TerminatorKind::*;
         match *self {
+            Call { target: Some(t), unwind: UnwindAction::Cleanup(ref u), .. }
+            | Yield { resume: t, drop: Some(ref u), .. }
+            | Drop { target: t, unwind: UnwindAction::Cleanup(ref u), .. }
+            | Assert { target: t, unwind: UnwindAction::Cleanup(ref u), .. }
+            | FalseUnwind { real_target: t, unwind: UnwindAction::Cleanup(ref u) }
+            | InlineAsm { destination: Some(t), unwind: UnwindAction::Cleanup(ref u), .. } => {
+                Some(t).into_iter().chain(slice::from_ref(u).into_iter().copied())
+            }
+            Goto { target: t }
+            | Call { target: None, unwind: UnwindAction::Cleanup(t), .. }
+            | Call { target: Some(t), unwind: _, .. }
+            | Yield { resume: t, drop: None, .. }
+            | Drop { target: t, unwind: _, .. }
+            | Assert { target: t, unwind: _, .. }
+            | FalseUnwind { real_target: t, unwind: _ }
+            | InlineAsm { destination: None, unwind: UnwindAction::Cleanup(t), .. }
+            | InlineAsm { destination: Some(t), unwind: _, .. } => {
+                Some(t).into_iter().chain((&[]).into_iter().copied())
+            }
             Resume
             | Abort
             | GeneratorDrop
             | Return
             | Unreachable
-            | Call { target: None, cleanup: None, .. }
-            | InlineAsm { destination: None, cleanup: None, .. } => {
+            | Call { target: None, unwind: _, .. }
+            | InlineAsm { destination: None, unwind: _, .. } => {
                 None.into_iter().chain((&[]).into_iter().copied())
             }
-            Goto { target: t }
-            | Call { target: None, cleanup: Some(t), .. }
-            | Call { target: Some(t), cleanup: None, .. }
-            | Yield { resume: t, drop: None, .. }
-            | Drop { target: t, unwind: None, .. }
-            | Assert { target: t, cleanup: None, .. }
-            | FalseUnwind { real_target: t, unwind: None }
-            | InlineAsm { destination: Some(t), cleanup: None, .. }
-            | InlineAsm { destination: None, cleanup: Some(t), .. } => {
-                Some(t).into_iter().chain((&[]).into_iter().copied())
-            }
-            Call { target: Some(t), cleanup: Some(ref u), .. }
-            | Yield { resume: t, drop: Some(ref u), .. }
-            | Drop { target: t, unwind: Some(ref u), .. }
-            | Assert { target: t, cleanup: Some(ref u), .. }
-            | FalseUnwind { real_target: t, unwind: Some(ref u) }
-            | InlineAsm { destination: Some(t), cleanup: Some(ref u), .. } => {
-                Some(t).into_iter().chain(slice::from_ref(u).into_iter().copied())
-            }
             SwitchInt { ref targets, .. } => {
                 None.into_iter().chain(targets.targets.iter().copied())
             }
@@ -175,32 +175,34 @@ impl<'tcx> TerminatorKind<'tcx> {
     pub fn successors_mut(&mut self) -> SuccessorsMut<'_> {
         use self::TerminatorKind::*;
         match *self {
+            Call { target: Some(ref mut t), unwind: UnwindAction::Cleanup(ref mut u), .. }
+            | Yield { resume: ref mut t, drop: Some(ref mut u), .. }
+            | Drop { target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u), .. }
+            | Assert { target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u), .. }
+            | FalseUnwind { real_target: ref mut t, unwind: UnwindAction::Cleanup(ref mut u) }
+            | InlineAsm {
+                destination: Some(ref mut t),
+                unwind: UnwindAction::Cleanup(ref mut u),
+                ..
+            } => Some(t).into_iter().chain(slice::from_mut(u)),
+            Goto { target: ref mut t }
+            | Call { target: None, unwind: UnwindAction::Cleanup(ref mut t), .. }
+            | Call { target: Some(ref mut t), unwind: _, .. }
+            | Yield { resume: ref mut t, drop: None, .. }
+            | Drop { target: ref mut t, unwind: _, .. }
+            | Assert { target: ref mut t, unwind: _, .. }
+            | FalseUnwind { real_target: ref mut t, unwind: _ }
+            | InlineAsm { destination: None, unwind: UnwindAction::Cleanup(ref mut t), .. }
+            | InlineAsm { destination: Some(ref mut t), unwind: _, .. } => {
+                Some(t).into_iter().chain(&mut [])
+            }
             Resume
             | Abort
             | GeneratorDrop
             | Return
             | Unreachable
-            | Call { target: None, cleanup: None, .. }
-            | InlineAsm { destination: None, cleanup: None, .. } => None.into_iter().chain(&mut []),
-            Goto { target: ref mut t }
-            | Call { target: None, cleanup: Some(ref mut t), .. }
-            | Call { target: Some(ref mut t), cleanup: None, .. }
-            | Yield { resume: ref mut t, drop: None, .. }
-            | Drop { target: ref mut t, unwind: None, .. }
-            | Assert { target: ref mut t, cleanup: None, .. }
-            | FalseUnwind { real_target: ref mut t, unwind: None }
-            | InlineAsm { destination: Some(ref mut t), cleanup: None, .. }
-            | InlineAsm { destination: None, cleanup: Some(ref mut t), .. } => {
-                Some(t).into_iter().chain(&mut [])
-            }
-            Call { target: Some(ref mut t), cleanup: Some(ref mut u), .. }
-            | Yield { resume: ref mut t, drop: Some(ref mut u), .. }
-            | Drop { target: ref mut t, unwind: Some(ref mut u), .. }
-            | Assert { target: ref mut t, cleanup: Some(ref mut u), .. }
-            | FalseUnwind { real_target: ref mut t, unwind: Some(ref mut u) }
-            | InlineAsm { destination: Some(ref mut t), cleanup: Some(ref mut u), .. } => {
-                Some(t).into_iter().chain(slice::from_mut(u))
-            }
+            | Call { target: None, unwind: _, .. }
+            | InlineAsm { destination: None, unwind: _, .. } => None.into_iter().chain(&mut []),
             SwitchInt { ref mut targets, .. } => None.into_iter().chain(&mut targets.targets),
             FalseEdge { ref mut real_target, ref mut imaginary_target } => {
                 Some(real_target).into_iter().chain(slice::from_mut(imaginary_target))
@@ -208,7 +210,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         }
     }
 
-    pub fn unwind(&self) -> Option<&Option<BasicBlock>> {
+    pub fn unwind(&self) -> Option<&UnwindAction> {
         match *self {
             TerminatorKind::Goto { .. }
             | TerminatorKind::Resume
@@ -219,15 +221,15 @@ impl<'tcx> TerminatorKind<'tcx> {
             | TerminatorKind::Yield { .. }
             | TerminatorKind::SwitchInt { .. }
             | TerminatorKind::FalseEdge { .. } => None,
-            TerminatorKind::Call { cleanup: ref unwind, .. }
-            | TerminatorKind::Assert { cleanup: ref unwind, .. }
+            TerminatorKind::Call { ref unwind, .. }
+            | TerminatorKind::Assert { ref unwind, .. }
             | TerminatorKind::Drop { ref unwind, .. }
             | TerminatorKind::FalseUnwind { ref unwind, .. }
-            | TerminatorKind::InlineAsm { cleanup: ref unwind, .. } => Some(unwind),
+            | TerminatorKind::InlineAsm { ref unwind, .. } => Some(unwind),
         }
     }
 
-    pub fn unwind_mut(&mut self) -> Option<&mut Option<BasicBlock>> {
+    pub fn unwind_mut(&mut self) -> Option<&mut UnwindAction> {
         match *self {
             TerminatorKind::Goto { .. }
             | TerminatorKind::Resume
@@ -238,11 +240,11 @@ impl<'tcx> TerminatorKind<'tcx> {
             | TerminatorKind::Yield { .. }
             | TerminatorKind::SwitchInt { .. }
             | TerminatorKind::FalseEdge { .. } => None,
-            TerminatorKind::Call { cleanup: ref mut unwind, .. }
-            | TerminatorKind::Assert { cleanup: ref mut unwind, .. }
+            TerminatorKind::Call { ref mut unwind, .. }
+            | TerminatorKind::Assert { ref mut unwind, .. }
             | TerminatorKind::Drop { ref mut unwind, .. }
             | TerminatorKind::FalseUnwind { ref mut unwind, .. }
-            | TerminatorKind::InlineAsm { cleanup: ref mut unwind, .. } => Some(unwind),
+            | TerminatorKind::InlineAsm { ref mut unwind, .. } => Some(unwind),
         }
     }
 
@@ -386,31 +388,33 @@ impl<'tcx> TerminatorKind<'tcx> {
                 .map(|&u| Cow::Owned(u.to_string()))
                 .chain(iter::once("otherwise".into()))
                 .collect(),
-            Call { target: Some(_), cleanup: Some(_), .. } => {
+            Call { target: Some(_), unwind: UnwindAction::Cleanup(_), .. } => {
                 vec!["return".into(), "unwind".into()]
             }
-            Call { target: Some(_), cleanup: None, .. } => vec!["return".into()],
-            Call { target: None, cleanup: Some(_), .. } => vec!["unwind".into()],
-            Call { target: None, cleanup: None, .. } => vec![],
+            Call { target: Some(_), unwind: UnwindAction::Continue, .. } => vec!["return".into()],
+            Call { target: None, unwind: UnwindAction::Cleanup(_), .. } => vec!["unwind".into()],
+            Call { target: None, unwind: UnwindAction::Continue, .. } => vec![],
             Yield { drop: Some(_), .. } => vec!["resume".into(), "drop".into()],
             Yield { drop: None, .. } => vec!["resume".into()],
-            Drop { unwind: None, .. } => {
-                vec!["return".into()]
-            }
-            Drop { unwind: Some(_), .. } => {
-                vec!["return".into(), "unwind".into()]
-            }
-            Assert { cleanup: None, .. } => vec!["".into()],
+            Drop { unwind: UnwindAction::Continue, .. } => vec!["return".into()],
+            Drop { unwind: UnwindAction::Cleanup(_), .. } => vec!["return".into(), "unwind".into()],
+            Assert { unwind: UnwindAction::Continue, .. } => vec!["".into()],
             Assert { .. } => vec!["success".into(), "unwind".into()],
             FalseEdge { .. } => vec!["real".into(), "imaginary".into()],
-            FalseUnwind { unwind: Some(_), .. } => vec!["real".into(), "cleanup".into()],
-            FalseUnwind { unwind: None, .. } => vec!["real".into()],
-            InlineAsm { destination: Some(_), cleanup: Some(_), .. } => {
+            FalseUnwind { unwind: UnwindAction::Cleanup(_), .. } => {
+                vec!["real".into(), "cleanup".into()]
+            }
+            FalseUnwind { unwind: UnwindAction::Continue, .. } => vec!["real".into()],
+            InlineAsm { destination: Some(_), unwind: UnwindAction::Cleanup(_), .. } => {
                 vec!["return".into(), "unwind".into()]
             }
-            InlineAsm { destination: Some(_), cleanup: None, .. } => vec!["return".into()],
-            InlineAsm { destination: None, cleanup: Some(_), .. } => vec!["unwind".into()],
-            InlineAsm { destination: None, cleanup: None, .. } => vec![],
+            InlineAsm { destination: Some(_), unwind: UnwindAction::Continue, .. } => {
+                vec!["return".into()]
+            }
+            InlineAsm { destination: None, unwind: UnwindAction::Cleanup(_), .. } => {
+                vec!["unwind".into()]
+            }
+            InlineAsm { destination: None, unwind: UnwindAction::Continue, .. } => vec![],
         }
     }
 }
diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs
index 7aa446ae966..243c62f4a9c 100644
--- a/compiler/rustc_middle/src/mir/visit.rs
+++ b/compiler/rustc_middle/src/mir/visit.rs
@@ -509,7 +509,7 @@ macro_rules! make_mir_visitor {
                         args,
                         destination,
                         target: _,
-                        cleanup: _,
+                        unwind: _,
                         from_hir_call: _,
                         fn_span: _
                     } => {
@@ -529,7 +529,7 @@ macro_rules! make_mir_visitor {
                         expected: _,
                         msg,
                         target: _,
-                        cleanup: _,
+                        unwind: _,
                     } => {
                         self.visit_operand(cond, location);
                         self.visit_assert_message(msg, location);
@@ -555,7 +555,7 @@ macro_rules! make_mir_visitor {
                         options: _,
                         line_spans: _,
                         destination: _,
-                        cleanup: _,
+                        unwind: _,
                     } => {
                         for op in operands {
                             match op {
diff --git a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
index baa12ec11c3..8631749a524 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
@@ -171,7 +171,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         args: vec![Operand::Move(size), Operand::Move(align)],
                         destination: storage,
                         target: Some(success),
-                        cleanup: None,
+                        unwind: UnwindAction::Continue,
                         from_hir_call: false,
                         fn_span: expr_span,
                     },
@@ -702,7 +702,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 this.cfg.terminate(
                     block,
                     outer_source_info,
-                    TerminatorKind::Drop { place: to_drop, target: success, unwind: None },
+                    TerminatorKind::Drop {
+                        place: to_drop,
+                        target: success,
+                        unwind: UnwindAction::Continue,
+                    },
                 );
                 this.diverge_from(block);
                 block = success;
diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs
index 8efaba1f602..bafe7ede3d9 100644
--- a/compiler/rustc_mir_build/src/build/expr/into.rs
+++ b/compiler/rustc_mir_build/src/build/expr/into.rs
@@ -228,7 +228,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     this.cfg.terminate(
                         loop_block,
                         source_info,
-                        TerminatorKind::FalseUnwind { real_target: body_block, unwind: None },
+                        TerminatorKind::FalseUnwind {
+                            real_target: body_block,
+                            unwind: UnwindAction::Continue,
+                        },
                     );
                     this.diverge_from(loop_block);
 
@@ -264,7 +267,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                     TerminatorKind::Call {
                         func: fun,
                         args,
-                        cleanup: None,
+                        unwind: UnwindAction::Continue,
                         destination,
                         // The presence or absence of a return edge affects control-flow sensitive
                         // MIR checks and ultimately whether code is accepted or not. We can only
@@ -466,7 +469,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         } else {
                             Some(destination_block)
                         },
-                        cleanup: None,
+                        unwind: UnwindAction::Continue,
                     },
                 );
                 if options.contains(InlineAsmOptions::MAY_UNWIND) {
diff --git a/compiler/rustc_mir_build/src/build/matches/test.rs b/compiler/rustc_mir_build/src/build/matches/test.rs
index 2de89f67dfd..8a03ea7e2cc 100644
--- a/compiler/rustc_mir_build/src/build/matches/test.rs
+++ b/compiler/rustc_mir_build/src/build/matches/test.rs
@@ -263,7 +263,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                             args: vec![Operand::Move(ref_string)],
                             destination: ref_str,
                             target: Some(eq_block),
-                            cleanup: None,
+                            unwind: UnwindAction::Continue,
                             from_hir_call: false,
                             fn_span: source_info.span
                         }
@@ -466,7 +466,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                 args: vec![val, expect],
                 destination: eq_result,
                 target: Some(eq_block),
-                cleanup: None,
+                unwind: UnwindAction::Continue,
                 from_hir_call: false,
                 fn_span: source_info.span,
             },
diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs
index 25af221bf36..f67659ac6bf 100644
--- a/compiler/rustc_mir_build/src/build/scope.rs
+++ b/compiler/rustc_mir_build/src/build/scope.rs
@@ -369,7 +369,7 @@ impl DropTree {
                     let terminator = TerminatorKind::Drop {
                         target: blocks[drop_data.1].unwrap(),
                         // The caller will handle this if needed.
-                        unwind: None,
+                        unwind: UnwindAction::Continue,
                         place: drop_data.0.local.into(),
                     };
                     cfg.terminate(block, drop_data.0.source_info, terminator);
@@ -1141,7 +1141,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         self.cfg.terminate(
             block,
             source_info,
-            TerminatorKind::Drop { place, target: assign, unwind: Some(assign_unwind) },
+            TerminatorKind::Drop {
+                place,
+                target: assign,
+                unwind: UnwindAction::Cleanup(assign_unwind),
+            },
         );
         self.diverge_from(block);
 
@@ -1165,7 +1169,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         self.cfg.terminate(
             block,
             source_info,
-            TerminatorKind::Assert { cond, expected, msg, target: success_block, cleanup: None },
+            TerminatorKind::Assert {
+                cond,
+                expected,
+                msg,
+                target: success_block,
+                unwind: UnwindAction::Continue,
+            },
         );
         self.diverge_from(block);
 
@@ -1244,7 +1254,11 @@ fn build_scope_drops<'tcx>(
                 cfg.terminate(
                     block,
                     source_info,
-                    TerminatorKind::Drop { place: local.into(), target: next, unwind: None },
+                    TerminatorKind::Drop {
+                        place: local.into(),
+                        target: next,
+                        unwind: UnwindAction::Continue,
+                    },
                 );
                 block = next;
             }
@@ -1432,10 +1446,10 @@ impl<'tcx> DropTreeBuilder<'tcx> for Unwind {
                 }
             }
             TerminatorKind::FalseUnwind { unwind, .. }
-            | TerminatorKind::Call { cleanup: unwind, .. }
-            | TerminatorKind::Assert { cleanup: unwind, .. }
-            | TerminatorKind::InlineAsm { cleanup: unwind, .. } => {
-                *unwind = Some(to);
+            | TerminatorKind::Call { unwind, .. }
+            | TerminatorKind::Assert { unwind, .. }
+            | TerminatorKind::InlineAsm { unwind, .. } => {
+                *unwind = UnwindAction::Cleanup(to);
             }
             TerminatorKind::Goto { .. }
             | TerminatorKind::SwitchInt { .. }
diff --git a/compiler/rustc_mir_build/src/lints.rs b/compiler/rustc_mir_build/src/lints.rs
index 8937b78fe34..910db7f676d 100644
--- a/compiler/rustc_mir_build/src/lints.rs
+++ b/compiler/rustc_mir_build/src/lints.rs
@@ -3,7 +3,7 @@ use rustc_data_structures::graph::iterate::{
     NodeStatus, TriColorDepthFirstSearch, TriColorVisitor,
 };
 use rustc_hir::def::DefKind;
-use rustc_middle::mir::{BasicBlock, BasicBlocks, Body, Operand, TerminatorKind};
+use rustc_middle::mir::{self, BasicBlock, BasicBlocks, Body, Operand, TerminatorKind};
 use rustc_middle::ty::subst::{GenericArg, InternalSubsts};
 use rustc_middle::ty::{self, Instance, TyCtxt};
 use rustc_session::lint::builtin::UNCONDITIONAL_RECURSION;
@@ -149,7 +149,9 @@ impl<'mir, 'tcx> TriColorVisitor<BasicBlocks<'tcx>> for Search<'mir, 'tcx> {
 
     fn ignore_edge(&mut self, bb: BasicBlock, target: BasicBlock) -> bool {
         let terminator = self.body[bb].terminator();
-        if terminator.unwind() == Some(&Some(target)) && terminator.successors().count() > 1 {
+        if terminator.unwind() == Some(&mir::UnwindAction::Cleanup(target))
+            && terminator.successors().count() > 1
+        {
             return true;
         }
         // Don't traverse successors of recursive calls or false CFG edges.
diff --git a/compiler/rustc_mir_dataflow/src/elaborate_drops.rs b/compiler/rustc_mir_dataflow/src/elaborate_drops.rs
index 7ef3d41ac48..70ed0c22640 100644
--- a/compiler/rustc_mir_dataflow/src/elaborate_drops.rs
+++ b/compiler/rustc_mir_dataflow/src/elaborate_drops.rs
@@ -77,10 +77,10 @@ impl Unwind {
         }
     }
 
-    fn into_option(self) -> Option<BasicBlock> {
+    fn into_action(self) -> UnwindAction {
         match self {
-            Unwind::To(bb) => Some(bb),
-            Unwind::InCleanup => None,
+            Unwind::To(bb) => UnwindAction::Cleanup(bb),
+            Unwind::InCleanup => UnwindAction::Continue,
         }
     }
 
@@ -236,7 +236,7 @@ where
                     TerminatorKind::Drop {
                         place: self.place,
                         target: self.succ,
-                        unwind: self.unwind.into_option(),
+                        unwind: self.unwind.into_action(),
                     },
                 );
             }
@@ -640,7 +640,7 @@ where
                     args: vec![Operand::Move(Place::from(ref_place))],
                     destination: unit_temp,
                     target: Some(succ),
-                    cleanup: unwind.into_option(),
+                    unwind: unwind.into_action(),
                     from_hir_call: true,
                     fn_span: self.source_info.span,
                 },
@@ -717,7 +717,7 @@ where
             TerminatorKind::Drop {
                 place: tcx.mk_place_deref(ptr),
                 target: loop_block,
-                unwind: unwind.into_option(),
+                unwind: unwind.into_action(),
             },
         );
 
@@ -946,7 +946,7 @@ where
             args,
             destination: unit_temp,
             target: Some(target),
-            cleanup: None,
+            unwind: UnwindAction::Continue,
             from_hir_call: false,
             fn_span: self.source_info.span,
         }; // FIXME(#43234)
@@ -959,7 +959,7 @@ where
 
     fn drop_block(&mut self, target: BasicBlock, unwind: Unwind) -> BasicBlock {
         let block =
-            TerminatorKind::Drop { place: self.place, target, unwind: unwind.into_option() };
+            TerminatorKind::Drop { place: self.place, target, unwind: unwind.into_action() };
         self.new_block(unwind, block)
     }
 
diff --git a/compiler/rustc_mir_dataflow/src/framework/direction.rs b/compiler/rustc_mir_dataflow/src/framework/direction.rs
index a40c38aa4c3..a078c6b550e 100644
--- a/compiler/rustc_mir_dataflow/src/framework/direction.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/direction.rs
@@ -1,4 +1,4 @@
-use rustc_middle::mir::{self, BasicBlock, Location, SwitchTargets};
+use rustc_middle::mir::{self, BasicBlock, Location, SwitchTargets, UnwindAction};
 use rustc_middle::ty::TyCtxt;
 use std::ops::RangeInclusive;
 
@@ -478,10 +478,10 @@ impl Direction for Forward {
 
             Goto { target } => propagate(target, exit_state),
 
-            Assert { target, cleanup: unwind, expected: _, msg: _, cond: _ }
+            Assert { target, unwind, expected: _, msg: _, cond: _ }
             | Drop { target, unwind, place: _ }
             | FalseUnwind { real_target: target, unwind } => {
-                if let Some(unwind) = unwind {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     propagate(unwind, exit_state);
                 }
 
@@ -503,7 +503,7 @@ impl Direction for Forward {
             }
 
             Call {
-                cleanup,
+                unwind,
                 destination,
                 target,
                 func: _,
@@ -511,7 +511,7 @@ impl Direction for Forward {
                 from_hir_call: _,
                 fn_span: _,
             } => {
-                if let Some(unwind) = cleanup {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     propagate(unwind, exit_state);
                 }
 
@@ -533,9 +533,9 @@ impl Direction for Forward {
                 options: _,
                 line_spans: _,
                 destination,
-                cleanup,
+                unwind,
             } => {
-                if let Some(unwind) = cleanup {
+                if let UnwindAction::Cleanup(unwind) = unwind {
                     propagate(unwind, exit_state);
                 }
 
diff --git a/compiler/rustc_mir_dataflow/src/framework/tests.rs b/compiler/rustc_mir_dataflow/src/framework/tests.rs
index 17102454a88..60679b17d6c 100644
--- a/compiler/rustc_mir_dataflow/src/framework/tests.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/tests.rs
@@ -39,7 +39,7 @@ fn mock_body<'tcx>() -> mir::Body<'tcx> {
             args: vec![],
             destination: dummy_place.clone(),
             target: Some(mir::START_BLOCK),
-            cleanup: None,
+            unwind: mir::UnwindAction::Continue,
             from_hir_call: false,
             fn_span: DUMMY_SP,
         },
@@ -53,7 +53,7 @@ fn mock_body<'tcx>() -> mir::Body<'tcx> {
             args: vec![],
             destination: dummy_place.clone(),
             target: Some(mir::START_BLOCK),
-            cleanup: None,
+            unwind: mir::UnwindAction::Continue,
             from_hir_call: false,
             fn_span: DUMMY_SP,
         },
diff --git a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
index d9ceac1154f..9f9a5c94b56 100644
--- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
+++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs
@@ -398,7 +398,7 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> {
                 ref args,
                 destination,
                 target,
-                cleanup: _,
+                unwind: _,
                 from_hir_call: _,
                 fn_span: _,
             } => {
@@ -417,7 +417,7 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> {
                 options: _,
                 line_spans: _,
                 destination: _,
-                cleanup: _,
+                unwind: _,
             } => {
                 for op in operands {
                     match *op {
diff --git a/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs b/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs
index 893018e0d8e..8fddbe4ad9f 100644
--- a/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs
+++ b/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs
@@ -125,13 +125,13 @@ impl<'tcx> MirPass<'tcx> for AbortUnwindingCalls {
 
             for bb in calls_to_terminate {
                 let cleanup = body.basic_blocks_mut()[bb].terminator_mut().unwind_mut().unwrap();
-                *cleanup = Some(abort_bb);
+                *cleanup = UnwindAction::Cleanup(abort_bb);
             }
         }
 
         for id in cleanups_to_remove {
             let cleanup = body.basic_blocks_mut()[id].terminator_mut().unwind_mut().unwrap();
-            *cleanup = None;
+            *cleanup = UnwindAction::Continue;
         }
 
         // We may have invalidated some `cleanup` blocks so clean those up now.
diff --git a/compiler/rustc_mir_transform/src/add_call_guards.rs b/compiler/rustc_mir_transform/src/add_call_guards.rs
index 30966d22e2f..ea7ccb512e0 100644
--- a/compiler/rustc_mir_transform/src/add_call_guards.rs
+++ b/compiler/rustc_mir_transform/src/add_call_guards.rs
@@ -50,10 +50,10 @@ impl AddCallGuards {
         for block in body.basic_blocks_mut() {
             match block.terminator {
                 Some(Terminator {
-                    kind: TerminatorKind::Call { target: Some(ref mut destination), cleanup, .. },
+                    kind: TerminatorKind::Call { target: Some(ref mut destination), unwind, .. },
                     source_info,
                 }) if pred_count[*destination] > 1
-                    && (cleanup.is_some() || self == &AllCallEdges) =>
+                    && (matches!(unwind, UnwindAction::Cleanup(_)) || self == &AllCallEdges) =>
                 {
                     // It's a critical edge, break it
                     let call_guard = BasicBlockData {
diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index ac55948e61b..b9af74a2061 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -228,7 +228,7 @@ impl<'mir, 'tcx> interpret::Machine<'mir, 'tcx> for ConstPropMachine<'mir, 'tcx>
     fn assert_panic(
         _ecx: &mut InterpCx<'mir, 'tcx, Self>,
         _msg: &rustc_middle::mir::AssertMessage<'tcx>,
-        _unwind: Option<rustc_middle::mir::BasicBlock>,
+        _unwind: rustc_middle::mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         bug!("panics terminators are not evaluated in ConstProp")
     }
diff --git a/compiler/rustc_mir_transform/src/coverage/tests.rs b/compiler/rustc_mir_transform/src/coverage/tests.rs
index 59b506e7345..0f6c06e370b 100644
--- a/compiler/rustc_mir_transform/src/coverage/tests.rs
+++ b/compiler/rustc_mir_transform/src/coverage/tests.rs
@@ -140,7 +140,7 @@ impl<'tcx> MockBlocks<'tcx> {
                 args: vec![],
                 destination: self.dummy_place.clone(),
                 target: Some(TEMP_BLOCK),
-                cleanup: None,
+                unwind: UnwindAction::Continue,
                 from_hir_call: false,
                 fn_span: DUMMY_SP,
             },
diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs
index a028d6356d5..9217c2dc81c 100644
--- a/compiler/rustc_mir_transform/src/elaborate_drops.rs
+++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs
@@ -120,7 +120,7 @@ fn remove_dead_unwinds<'tcx>(
         .into_results_cursor(body);
     for (bb, bb_data) in body.basic_blocks.iter_enumerated() {
         let place = match bb_data.terminator().kind {
-            TerminatorKind::Drop { ref place, unwind: Some(_), .. } => {
+            TerminatorKind::Drop { ref place, unwind: UnwindAction::Cleanup(_), .. } => {
                 und.derefer(place.as_ref(), body).unwrap_or(*place)
             }
             _ => continue,
@@ -417,7 +417,10 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> {
                             if data.is_cleanup {
                                 Unwind::InCleanup
                             } else {
-                                Unwind::To(Option::unwrap_or(unwind, resume_block))
+                                match unwind {
+                                    UnwindAction::Cleanup(cleanup) => Unwind::To(cleanup),
+                                    UnwindAction::Continue => Unwind::To(resume_block),
+                                }
                             },
                             bb,
                         ),
@@ -474,7 +477,10 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> {
                 continue;
             }
             if let TerminatorKind::Call {
-                destination, target: Some(tgt), cleanup: Some(_), ..
+                destination,
+                target: Some(tgt),
+                unwind: UnwindAction::Cleanup(_),
+                ..
             } = data.terminator().kind
             {
                 assert!(!self.patch.is_patched(bb));
@@ -543,8 +549,12 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> {
             // There may be a critical edge after this call,
             // so mark the return as initialized *before* the
             // call.
-            if let TerminatorKind::Call { destination, target: Some(_), cleanup: None, .. } =
-                data.terminator().kind
+            if let TerminatorKind::Call {
+                destination,
+                target: Some(_),
+                unwind: UnwindAction::Continue,
+                ..
+            } = data.terminator().kind
             {
                 assert!(!self.patch.is_patched(bb));
 
diff --git a/compiler/rustc_mir_transform/src/function_item_references.rs b/compiler/rustc_mir_transform/src/function_item_references.rs
index 66d32b954e4..8601c1b2d71 100644
--- a/compiler/rustc_mir_transform/src/function_item_references.rs
+++ b/compiler/rustc_mir_transform/src/function_item_references.rs
@@ -34,7 +34,7 @@ impl<'tcx> Visitor<'tcx> for FunctionItemRefChecker<'_, 'tcx> {
             args,
             destination: _,
             target: _,
-            cleanup: _,
+            unwind: _,
             from_hir_call: _,
             fn_span: _,
         } = &terminator.kind
diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs
index af6422c7246..a83e6a5b680 100644
--- a/compiler/rustc_mir_transform/src/generator.rs
+++ b/compiler/rustc_mir_transform/src/generator.rs
@@ -1060,7 +1060,10 @@ fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let unwind = if block_data.is_cleanup {
             Unwind::InCleanup
         } else {
-            Unwind::To(unwind.unwrap_or_else(|| elaborator.patch.resume_block()))
+            Unwind::To(match *unwind {
+                UnwindAction::Cleanup(tgt) => tgt,
+                UnwindAction::Continue => elaborator.patch.resume_block(),
+            })
         };
         elaborate_drop(
             &mut elaborator,
@@ -1147,7 +1150,7 @@ fn insert_panic_block<'tcx>(
         expected: true,
         msg: message,
         target: assert_block,
-        cleanup: None,
+        unwind: UnwindAction::Continue,
     };
 
     let source_info = SourceInfo::outermost(body.span);
@@ -1248,8 +1251,8 @@ fn create_generator_resume_function<'tcx>(
             } else if !block.is_cleanup {
                 // Any terminators that *can* unwind but don't have an unwind target set are also
                 // pointed at our poisoning block (unless they're part of the cleanup path).
-                if let Some(unwind @ None) = block.terminator_mut().unwind_mut() {
-                    *unwind = Some(poison_block);
+                if let Some(unwind @ UnwindAction::Continue) = block.terminator_mut().unwind_mut() {
+                    *unwind = UnwindAction::Cleanup(poison_block);
                 }
             }
         }
@@ -1294,8 +1297,11 @@ fn create_generator_resume_function<'tcx>(
 fn insert_clean_drop(body: &mut Body<'_>) -> BasicBlock {
     let return_block = insert_term_block(body, TerminatorKind::Return);
 
-    let term =
-        TerminatorKind::Drop { place: Place::from(SELF_ARG), target: return_block, unwind: None };
+    let term = TerminatorKind::Drop {
+        place: Place::from(SELF_ARG),
+        target: return_block,
+        unwind: UnwindAction::Continue,
+    };
     let source_info = SourceInfo::outermost(body.span);
 
     // Create a block to destroy an unresumed generators. This can only destroy upvars.
@@ -1670,7 +1676,7 @@ impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> {
                 args,
                 destination,
                 target: Some(_),
-                cleanup: _,
+                unwind: _,
                 from_hir_call: _,
                 fn_span: _,
             } => {
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index 15b31d38394..c46cb5e98df 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -453,7 +453,7 @@ impl<'tcx> Inliner<'tcx> {
 
                 // If the place doesn't actually need dropping, treat it like a regular goto.
                 let ty = callsite.callee.subst_mir(self.tcx, &place.ty(callee_body, tcx).ty);
-                if ty.needs_drop(tcx, self.param_env) && let Some(unwind) = unwind {
+                if ty.needs_drop(tcx, self.param_env) && let UnwindAction::Cleanup(unwind) = unwind {
                         work_list.push(unwind);
                     }
             } else if callee_attrs.instruction_set != self.codegen_fn_attrs.instruction_set
@@ -500,7 +500,7 @@ impl<'tcx> Inliner<'tcx> {
     ) {
         let terminator = caller_body[callsite.block].terminator.take().unwrap();
         match terminator.kind {
-            TerminatorKind::Call { args, destination, cleanup, .. } => {
+            TerminatorKind::Call { args, destination, unwind, .. } => {
                 // If the call is something like `a[*i] = f(i)`, where
                 // `i : &mut usize`, then just duplicating the `a[*i]`
                 // Place could result in two different locations if `f`
@@ -571,7 +571,7 @@ impl<'tcx> Inliner<'tcx> {
                     destination: destination_local,
                     callsite_scope: caller_body.source_scopes[callsite.source_info.scope].clone(),
                     callsite,
-                    cleanup_block: cleanup,
+                    cleanup_block: unwind,
                     in_cleanup_block: false,
                     tcx: self.tcx,
                     expn_data,
@@ -813,14 +813,14 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
                 let ty = self.instance.subst_mir(tcx, &place.ty(self.callee_body, tcx).ty);
                 if ty.needs_drop(tcx, self.param_env) {
                     self.cost += CALL_PENALTY;
-                    if unwind.is_some() {
+                    if let UnwindAction::Cleanup(_) = unwind {
                         self.cost += LANDINGPAD_PENALTY;
                     }
                 } else {
                     self.cost += INSTR_COST;
                 }
             }
-            TerminatorKind::Call { func: Operand::Constant(ref f), cleanup, .. } => {
+            TerminatorKind::Call { func: Operand::Constant(ref f), unwind, .. } => {
                 let fn_ty = self.instance.subst_mir(tcx, &f.literal.ty());
                 self.cost += if let ty::FnDef(def_id, _) = *fn_ty.kind() && tcx.is_intrinsic(def_id) {
                     // Don't give intrinsics the extra penalty for calls
@@ -828,20 +828,20 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
                 } else {
                     CALL_PENALTY
                 };
-                if cleanup.is_some() {
+                if let UnwindAction::Cleanup(_) = unwind {
                     self.cost += LANDINGPAD_PENALTY;
                 }
             }
-            TerminatorKind::Assert { cleanup, .. } => {
+            TerminatorKind::Assert { unwind, .. } => {
                 self.cost += CALL_PENALTY;
-                if cleanup.is_some() {
+                if let UnwindAction::Cleanup(_) = unwind {
                     self.cost += LANDINGPAD_PENALTY;
                 }
             }
             TerminatorKind::Resume => self.cost += RESUME_PENALTY,
-            TerminatorKind::InlineAsm { cleanup, .. } => {
+            TerminatorKind::InlineAsm { unwind, .. } => {
                 self.cost += INSTR_COST;
-                if cleanup.is_some() {
+                if let UnwindAction::Cleanup(_) = unwind {
                     self.cost += LANDINGPAD_PENALTY;
                 }
             }
@@ -979,7 +979,7 @@ struct Integrator<'a, 'tcx> {
     destination: Local,
     callsite_scope: SourceScopeData<'tcx>,
     callsite: &'a CallSite<'tcx>,
-    cleanup_block: Option<BasicBlock>,
+    cleanup_block: UnwindAction,
     in_cleanup_block: bool,
     tcx: TyCtxt<'tcx>,
     expn_data: LocalExpnId,
@@ -1014,18 +1014,20 @@ impl Integrator<'_, '_> {
         new
     }
 
-    fn map_unwind(&self, unwind: Option<BasicBlock>) -> Option<BasicBlock> {
+    fn map_unwind(&self, unwind: UnwindAction) -> UnwindAction {
         if self.in_cleanup_block {
-            if unwind.is_some() {
-                bug!("cleanup on cleanup block");
+            match unwind {
+                UnwindAction::Cleanup(_) => {
+                    bug!("cleanup on cleanup block");
+                }
+                UnwindAction::Continue => return unwind,
             }
-            return unwind;
         }
 
         match unwind {
-            Some(target) => Some(self.map_block(target)),
+            UnwindAction::Cleanup(target) => UnwindAction::Cleanup(self.map_block(target)),
             // Add an unwind edge to the original call's cleanup block
-            None => self.cleanup_block,
+            UnwindAction::Continue => self.cleanup_block,
         }
     }
 }
@@ -1116,15 +1118,15 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
                 *target = self.map_block(*target);
                 *unwind = self.map_unwind(*unwind);
             }
-            TerminatorKind::Call { ref mut target, ref mut cleanup, .. } => {
+            TerminatorKind::Call { ref mut target, ref mut unwind, .. } => {
                 if let Some(ref mut tgt) = *target {
                     *tgt = self.map_block(*tgt);
                 }
-                *cleanup = self.map_unwind(*cleanup);
+                *unwind = self.map_unwind(*unwind);
             }
-            TerminatorKind::Assert { ref mut target, ref mut cleanup, .. } => {
+            TerminatorKind::Assert { ref mut target, ref mut unwind, .. } => {
                 *target = self.map_block(*target);
-                *cleanup = self.map_unwind(*cleanup);
+                *unwind = self.map_unwind(*unwind);
             }
             TerminatorKind::Return => {
                 terminator.kind = if let Some(tgt) = self.callsite.target {
@@ -1133,11 +1135,12 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
                     TerminatorKind::Unreachable
                 }
             }
-            TerminatorKind::Resume => {
-                if let Some(tgt) = self.cleanup_block {
-                    terminator.kind = TerminatorKind::Goto { target: tgt }
+            TerminatorKind::Resume => match self.cleanup_block {
+                UnwindAction::Cleanup(tgt) => {
+                    terminator.kind = TerminatorKind::Goto { target: tgt };
                 }
-            }
+                UnwindAction::Continue => (),
+            },
             TerminatorKind::Abort => {}
             TerminatorKind::Unreachable => {}
             TerminatorKind::FalseEdge { ref mut real_target, ref mut imaginary_target } => {
@@ -1149,11 +1152,11 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
             {
                 bug!("False unwinds should have been removed before inlining")
             }
-            TerminatorKind::InlineAsm { ref mut destination, ref mut cleanup, .. } => {
+            TerminatorKind::InlineAsm { ref mut destination, ref mut unwind, .. } => {
                 if let Some(ref mut tgt) = *destination {
                     *tgt = self.map_block(*tgt);
                 }
-                *cleanup = self.map_unwind(*cleanup);
+                *unwind = self.map_unwind(*unwind);
             }
         }
     }
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index b52de4b72c9..2e418c1dafc 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -159,7 +159,7 @@ fn remap_mir_for_const_eval_select<'tcx>(
                 ref mut args,
                 destination,
                 target,
-                cleanup,
+                unwind,
                 fn_span,
                 ..
             } if let ty::FnDef(def_id, _) = *literal.ty().kind()
@@ -196,7 +196,7 @@ fn remap_mir_for_const_eval_select<'tcx>(
                     };
                     method(place)
                 }).collect();
-                terminator.kind = TerminatorKind::Call { func, args: arguments, destination, target, cleanup, from_hir_call: false, fn_span };
+                terminator.kind = TerminatorKind::Call { func, args: arguments, destination, target, unwind, from_hir_call: false, fn_span };
             }
             _ => {}
         }
diff --git a/compiler/rustc_mir_transform/src/lower_slice_len.rs b/compiler/rustc_mir_transform/src/lower_slice_len.rs
index 101fae2f08c..75a415d88ee 100644
--- a/compiler/rustc_mir_transform/src/lower_slice_len.rs
+++ b/compiler/rustc_mir_transform/src/lower_slice_len.rs
@@ -54,7 +54,7 @@ fn lower_slice_len_call<'tcx>(
             args,
             destination,
             target: Some(bb),
-            cleanup: None,
+            unwind: UnwindAction::Continue,
             from_hir_call: true,
             ..
         } => {
diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
index e962819b691..b4d68f4a322 100644
--- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
+++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs
@@ -103,11 +103,11 @@ impl RemoveNoopLandingPads {
         for bb in postorder {
             debug!("  processing {:?}", bb);
             if let Some(unwind) = body[bb].terminator_mut().unwind_mut() {
-                if let Some(unwind_bb) = *unwind {
+                if let UnwindAction::Cleanup(unwind_bb) = *unwind {
                     if nop_landing_pads.contains(unwind_bb) {
                         debug!("    removing noop landing pad");
                         landing_pads_removed += 1;
-                        *unwind = None;
+                        *unwind = UnwindAction::Continue;
                     }
                 }
             }
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs
index 9e406eba0fc..f5a65e12705 100644
--- a/compiler/rustc_mir_transform/src/shim.rs
+++ b/compiler/rustc_mir_transform/src/shim.rs
@@ -499,7 +499,7 @@ impl<'tcx> CloneShimBuilder<'tcx> {
                 args: vec![Operand::Move(ref_loc)],
                 destination: dest,
                 target: Some(next),
-                cleanup: Some(cleanup),
+                unwind: UnwindAction::Cleanup(cleanup),
                 from_hir_call: true,
                 fn_span: self.span,
             },
@@ -540,7 +540,11 @@ impl<'tcx> CloneShimBuilder<'tcx> {
             self.make_clone_call(dest_field, src_field, ity, next_block, unwind);
             self.block(
                 vec![],
-                TerminatorKind::Drop { place: dest_field, target: unwind, unwind: None },
+                TerminatorKind::Drop {
+                    place: dest_field,
+                    target: unwind,
+                    unwind: UnwindAction::Continue,
+                },
                 true,
             );
             unwind = next_unwind;
@@ -776,10 +780,10 @@ fn build_call_shim<'tcx>(
             args,
             destination: Place::return_place(),
             target: Some(BasicBlock::new(1)),
-            cleanup: if let Some(Adjustment::RefMut) = rcvr_adjustment {
-                Some(BasicBlock::new(3))
+            unwind: if let Some(Adjustment::RefMut) = rcvr_adjustment {
+                UnwindAction::Cleanup(BasicBlock::new(3))
             } else {
-                None
+                UnwindAction::Continue
             },
             from_hir_call: true,
             fn_span: span,
@@ -792,7 +796,11 @@ fn build_call_shim<'tcx>(
         block(
             &mut blocks,
             vec![],
-            TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(2), unwind: None },
+            TerminatorKind::Drop {
+                place: rcvr_place(),
+                target: BasicBlock::new(2),
+                unwind: UnwindAction::Continue,
+            },
             false,
         );
     }
@@ -803,7 +811,11 @@ fn build_call_shim<'tcx>(
         block(
             &mut blocks,
             vec![],
-            TerminatorKind::Drop { place: rcvr_place(), target: BasicBlock::new(4), unwind: None },
+            TerminatorKind::Drop {
+                place: rcvr_place(),
+                target: BasicBlock::new(4),
+                unwind: UnwindAction::Continue,
+            },
             true,
         );
 
diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
index d66640ba0b7..ff195cd7288 100644
--- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
+++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs
@@ -318,7 +318,7 @@ fn check_terminator<'tcx>(
             from_hir_call: _,
             destination: _,
             target: _,
-            cleanup: _,
+            unwind: _,
             fn_span: _,
         } => {
             let fn_ty = func.ty(body, tcx);
@@ -361,7 +361,7 @@ fn check_terminator<'tcx>(
             expected: _,
             msg: _,
             target: _,
-            cleanup: _,
+            unwind: _,
         } => check_operand(tcx, cond, span, body),
 
         TerminatorKind::InlineAsm { .. } => Err((span, "cannot use inline assembly in const fn".into())),
diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs
index cc1964de332..621b90f0e57 100644
--- a/src/tools/miri/src/machine.rs
+++ b/src/tools/miri/src/machine.rs
@@ -868,7 +868,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
     fn assert_panic(
         ecx: &mut MiriInterpCx<'mir, 'tcx>,
         msg: &mir::AssertMessage<'tcx>,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         ecx.assert_panic(msg, unwind)
     }
diff --git a/src/tools/miri/src/shims/panic.rs b/src/tools/miri/src/shims/panic.rs
index acc97c4b8a0..c31194b4b93 100644
--- a/src/tools/miri/src/shims/panic.rs
+++ b/src/tools/miri/src/shims/panic.rs
@@ -189,7 +189,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn assert_panic(
         &mut self,
         msg: &mir::AssertMessage<'tcx>,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         use rustc_middle::mir::AssertKind::*;
         let this = self.eval_context_mut();