Rollup merge of rust-lang#112972 - nbdd0121:mir, r=davidtwco

Make `UnwindAction::Continue` explicit in MIR dump

Makes it easier to spot unwinding related issues in MIR by making `UnwindAction::Continue` explicit, just like all other `UnwindAction`s.

compiler/rustc_middle/src/mir/terminator.rs

@@ -272,7 +272,8 @@ impl<'tcx> Debug for TerminatorKind<'tcx> {
 
         let unwind = match self.unwind() {
             // Not needed or included in successors
-            None | Some(UnwindAction::Continue) | Some(UnwindAction::Cleanup(_)) => None,
+            None | Some(UnwindAction::Cleanup(_)) => None,
+            Some(UnwindAction::Continue) => Some("unwind continue"),
             Some(UnwindAction::Unreachable) => Some("unwind unreachable"),
             Some(UnwindAction::Terminate) => Some("unwind terminate"),
         };

tests/mir-opt/array_index_is_temporary.main.SimplifyCfg-elaborate-drops.after.panic-unwind.mir

@@ -36,7 +36,7 @@ fn main() -> () {
         StorageLive(_5);
         StorageLive(_6);
         _6 = _3;
-        _5 = foo(move _6) -> bb1;
+        _5 = foo(move _6) -> [return: bb1, unwind continue];
     }
 
     bb1: {
@@ -45,7 +45,7 @@ fn main() -> () {
         _7 = _2;
         _8 = Len(_1);
         _9 = Lt(_7, _8);
-        assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, _7) -> bb2;
+        assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, _7) -> [success: bb2, unwind continue];
     }
 
     bb2: {

tests/mir-opt/basic_assignment.main.ElaborateDrops.diff

@@ -58,7 +58,7 @@
 
       bb4: {
           StorageDead(_5);
--         drop(_4) -> bb5;
+-         drop(_4) -> [return: bb5, unwind continue];
 +         goto -> bb5;
       }
 

tests/mir-opt/box_expr.main.ElaborateDrops.before.panic-unwind.mir

@@ -19,7 +19,7 @@ fn main() -> () {
         StorageLive(_1);
         _2 = SizeOf(S);
         _3 = AlignOf(S);
-        _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> bb1;
+        _4 = alloc::alloc::exchange_malloc(move _2, move _3) -> [return: bb1, unwind continue];
     }
 
     bb1: {
@@ -30,7 +30,7 @@ fn main() -> () {
 
     bb2: {
         _1 = move _5;
-        drop(_5) -> bb3;
+        drop(_5) -> [return: bb3, unwind continue];
     }
 
     bb3: {
@@ -45,7 +45,7 @@ fn main() -> () {
         StorageDead(_7);
         StorageDead(_6);
         _0 = const ();
-        drop(_1) -> bb5;
+        drop(_1) -> [return: bb5, unwind continue];
     }
 
     bb5: {

tests/mir-opt/building/async_await.a-{closure#0}.generator_resume.0.mir

@@ -30,7 +30,7 @@ fn a::{closure#0}(_1: Pin<&mut [async fn body@$DIR/async_await.rs:11:14: 11:16]>
     }
 
     bb2: {
-        assert(const false, "`async fn` resumed after completion") -> bb2;
+        assert(const false, "`async fn` resumed after completion") -> [success: bb2, unwind continue];
     }
 
     bb3: {

tests/mir-opt/building/async_await.b-{closure#0}.generator_resume.0.mir

@@ -310,7 +310,7 @@ fn b::{closure#0}(_1: Pin<&mut [async fn body@$DIR/async_await.rs:14:18: 17:2]>,
     }
 
     bb28: {
-        assert(const false, "`async fn` resumed after completion") -> bb28;
+        assert(const false, "`async fn` resumed after completion") -> [success: bb28, unwind continue];
     }
 
     bb29: {

tests/mir-opt/building/custom/terminators.direct_call.built.after.mir

@@ -4,7 +4,7 @@ fn direct_call(_1: i32) -> i32 {
     let mut _0: i32;
 
     bb0: {
-        _0 = ident::<i32>(_1) -> bb1;
+        _0 = ident::<i32>(_1) -> [return: bb1, unwind continue];
     }
 
     bb1: {

tests/mir-opt/building/custom/terminators.drop_first.built.after.mir

@@ -4,7 +4,7 @@ fn drop_first(_1: WriteOnDrop<'_>, _2: WriteOnDrop<'_>) -> () {
     let mut _0: ();
 
     bb0: {
-        drop(_1) -> bb1;
+        drop(_1) -> [return: bb1, unwind continue];
     }
 
     bb1: {

tests/mir-opt/building/custom/terminators.drop_second.built.after.mir

@@ -4,7 +4,7 @@ fn drop_second(_1: WriteOnDrop<'_>, _2: WriteOnDrop<'_>) -> () {
     let mut _0: ();
 
     bb0: {
-        drop(_2) -> bb1;
+        drop(_2) -> [return: bb1, unwind continue];
     }
 
     bb1: {

tests/mir-opt/building/custom/terminators.indirect_call.built.after.mir

@@ -4,7 +4,7 @@ fn indirect_call(_1: i32, _2: fn(i32) -> i32) -> i32 {
     let mut _0: i32;
 
     bb0: {
-        _0 = _2(_1) -> bb1;
+        _0 = _2(_1) -> [return: bb1, unwind continue];
     }
 
     bb1: {

tests/mir-opt/combine_array_len.norm2.InstSimplify.panic-unwind.diff

@@ -32,7 +32,7 @@
 -         _4 = Len(_1);
 +         _4 = const 2_usize;
           _5 = Lt(_3, _4);
-          assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
+          assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
       }
 
       bb1: {
@@ -44,7 +44,7 @@
 -         _8 = Len(_1);
 +         _8 = const 2_usize;
           _9 = Lt(_7, _8);
-          assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, _7) -> bb2;
+          assert(move _9, "index out of bounds: the length is {} but the index is {}", move _8, _7) -> [success: bb2, unwind continue];
       }
 
       bb2: {

tests/mir-opt/combine_clone_of_primitives.{impl#0}-clone.InstSimplify.panic-unwind.diff

@@ -21,7 +21,7 @@
           _4 = &((*_1).0: T);
 -         _3 = &(*_4);
 +         _3 = _4;
-          _2 = <T as Clone>::clone(move _3) -> bb1;
+          _2 = <T as Clone>::clone(move _3) -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/aggregate.main.ConstProp.panic-unwind.diff

@@ -27,7 +27,7 @@
           StorageLive(_5);
 -         _5 = _1;
 +         _5 = const 1_u8;
-          _4 = foo(move _5) -> bb1;
+          _4 = foo(move _5) -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/aggregate.main.PreCodegen.after.panic-unwind.mir

@@ -23,7 +23,7 @@ fn main() -> () {
         StorageLive(_4);
         StorageLive(_5);
         _5 = const 1_u8;
-        _4 = foo(move _5) -> bb1;
+        _4 = foo(move _5) -> [return: bb1, unwind continue];
     }
 
     bb1: {

tests/mir-opt/const_prop/array_index.main.ConstProp.32bit.panic-unwind.diff

@@ -20,10 +20,10 @@
           _3 = const 2_usize;
 -         _4 = Len(_2);
 -         _5 = Lt(_3, _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
 +         _4 = const 4_usize;
 +         _5 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/array_index.main.ConstProp.64bit.panic-unwind.diff

@@ -20,10 +20,10 @@
           _3 = const 2_usize;
 -         _4 = Len(_2);
 -         _5 = Lt(_3, _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
 +         _4 = const 4_usize;
 +         _5 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/bad_op_div_by_zero.main.ConstProp.panic-unwind.diff

@@ -24,21 +24,21 @@
           StorageLive(_3);
 -         _3 = _1;
 -         _4 = Eq(_3, const 0_i32);
--         assert(!move _4, "attempt to divide `{}` by zero", const 1_i32) -> bb1;
+-         assert(!move _4, "attempt to divide `{}` by zero", const 1_i32) -> [success: bb1, unwind continue];
 +         _3 = const 0_i32;
 +         _4 = const true;
-+         assert(!const true, "attempt to divide `{}` by zero", const 1_i32) -> bb1;
++         assert(!const true, "attempt to divide `{}` by zero", const 1_i32) -> [success: bb1, unwind continue];
       }
 
       bb1: {
 -         _5 = Eq(_3, const -1_i32);
 -         _6 = Eq(const 1_i32, const i32::MIN);
 -         _7 = BitAnd(move _5, move _6);
--         assert(!move _7, "attempt to compute `{} / {}`, which would overflow", const 1_i32, _3) -> bb2;
+-         assert(!move _7, "attempt to compute `{} / {}`, which would overflow", const 1_i32, _3) -> [success: bb2, unwind continue];
 +         _5 = const false;
 +         _6 = const false;
 +         _7 = const false;
-+         assert(!const false, "attempt to compute `{} / {}`, which would overflow", const 1_i32, _3) -> bb2;
++         assert(!const false, "attempt to compute `{} / {}`, which would overflow", const 1_i32, _3) -> [success: bb2, unwind continue];
       }
 
       bb2: {

tests/mir-opt/const_prop/bad_op_mod_by_zero.main.ConstProp.panic-unwind.diff

@@ -24,21 +24,21 @@
           StorageLive(_3);
 -         _3 = _1;
 -         _4 = Eq(_3, const 0_i32);
--         assert(!move _4, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_i32) -> bb1;
+-         assert(!move _4, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_i32) -> [success: bb1, unwind continue];
 +         _3 = const 0_i32;
 +         _4 = const true;
-+         assert(!const true, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_i32) -> bb1;
++         assert(!const true, "attempt to calculate the remainder of `{}` with a divisor of zero", const 1_i32) -> [success: bb1, unwind continue];
       }
 
       bb1: {
 -         _5 = Eq(_3, const -1_i32);
 -         _6 = Eq(const 1_i32, const i32::MIN);
 -         _7 = BitAnd(move _5, move _6);
--         assert(!move _7, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _3) -> bb2;
+-         assert(!move _7, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _3) -> [success: bb2, unwind continue];
 +         _5 = const false;
 +         _6 = const false;
 +         _7 = const false;
-+         assert(!const false, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _3) -> bb2;
++         assert(!const false, "attempt to compute the remainder of `{} % {}`, which would overflow", const 1_i32, _3) -> [success: bb2, unwind continue];
       }
 
       bb2: {

tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.32bit.panic-unwind.diff

@@ -36,9 +36,9 @@
           _6 = const 3_usize;
           _7 = const 3_usize;
 -         _8 = Lt(_6, _7);
--         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1;
+-         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> [success: bb1, unwind continue];
 +         _8 = const false;
-+         assert(const false, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1;
++         assert(const false, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/bad_op_unsafe_oob_for_slices.main.ConstProp.64bit.panic-unwind.diff

@@ -36,9 +36,9 @@
           _6 = const 3_usize;
           _7 = const 3_usize;
 -         _8 = Lt(_6, _7);
--         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1;
+-         assert(move _8, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> [success: bb1, unwind continue];
 +         _8 = const false;
-+         assert(const false, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> bb1;
++         assert(const false, "index out of bounds: the length is {} but the index is {}", move _7, _6) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/boxes.main.ConstProp.panic-unwind.diff

@@ -26,7 +26,7 @@
 -         _5 = AlignOf(i32);
 +         _4 = const 4_usize;
 +         _5 = const 4_usize;
-          _6 = alloc::alloc::exchange_malloc(move _4, move _5) -> bb1;
+          _6 = alloc::alloc::exchange_malloc(move _4, move _5) -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/checked_add.main.ConstProp.panic-unwind.diff

@@ -12,9 +12,9 @@
       bb0: {
           StorageLive(_1);
 -         _2 = CheckedAdd(const 1_u32, const 1_u32);
--         assert(!move (_2.1: bool), "attempt to compute `{} + {}`, which would overflow", const 1_u32, const 1_u32) -> bb1;
+-         assert(!move (_2.1: bool), "attempt to compute `{} + {}`, which would overflow", const 1_u32, const 1_u32) -> [success: bb1, unwind continue];
 +         _2 = const (2_u32, false);
-+         assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 1_u32, const 1_u32) -> bb1;
++         assert(!const false, "attempt to compute `{} + {}`, which would overflow", const 1_u32, const 1_u32) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/const_prop_fails_gracefully.main.ConstProp.panic-unwind.diff

@@ -24,7 +24,7 @@
           StorageLive(_4);
           StorageLive(_5);
           _5 = _1;
-          _4 = read(move _5) -> bb1;
+          _4 = read(move _5) -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/control_flow_simplification.hello.ConstProp.panic-unwind.diff

@@ -14,7 +14,7 @@
       }
 
       bb1: {
-          _2 = begin_panic::<&str>(const "explicit panic");
+          _2 = begin_panic::<&str>(const "explicit panic") -> unwind continue;
       }
 
       bb2: {

tests/mir-opt/const_prop/indirect.main.ConstProp.panic-unwind.diff

@@ -15,10 +15,10 @@
           StorageLive(_2);
 -         _2 = const 2_u32 as u8 (IntToInt);
 -         _3 = CheckedAdd(_2, const 1_u8);
--         assert(!move (_3.1: bool), "attempt to compute `{} + {}`, which would overflow", move _2, const 1_u8) -> bb1;
+-         assert(!move (_3.1: bool), "attempt to compute `{} + {}`, which would overflow", move _2, const 1_u8) -> [success: bb1, unwind continue];
 +         _2 = const 2_u8;
 +         _3 = const (3_u8, false);
-+         assert(!const false, "attempt to compute `{} + {}`, which would overflow", move _2, const 1_u8) -> bb1;
++         assert(!const false, "attempt to compute `{} + {}`, which would overflow", move _2, const 1_u8) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/inherit_overflow.main.ConstProp.panic-unwind.diff

@@ -21,9 +21,9 @@
           StorageLive(_3);
           _3 = const 1_u8;
 -         _4 = CheckedAdd(_2, _3);
--         assert(!move (_4.1: bool), "attempt to compute `{} + {}`, which would overflow", _2, _3) -> bb1;
+-         assert(!move (_4.1: bool), "attempt to compute `{} + {}`, which would overflow", _2, _3) -> [success: bb1, unwind continue];
 +         _4 = const (0_u8, true);
-+         assert(!const true, "attempt to compute `{} + {}`, which would overflow", _2, _3) -> bb1;
++         assert(!const true, "attempt to compute `{} + {}`, which would overflow", _2, _3) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/issue_66971.main.ConstProp.panic-unwind.diff

@@ -9,7 +9,7 @@
       bb0: {
           StorageLive(_2);
           _2 = (const (), const 0_u8, const 0_u8);
-          _1 = encode(move _2) -> bb1;
+          _1 = encode(move _2) -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/issue_67019.main.ConstProp.panic-unwind.diff

@@ -14,7 +14,7 @@
 +         _3 = const (1_u8, 2_u8);
           _2 = (move _3,);
           StorageDead(_3);
-          _1 = test(move _2) -> bb1;
+          _1 = test(move _2) -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/large_array_index.main.ConstProp.32bit.panic-unwind.diff

@@ -20,10 +20,10 @@
           _3 = const 2_usize;
 -         _4 = Len(_2);
 -         _5 = Lt(_3, _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
 +         _4 = const 5000_usize;
 +         _5 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/large_array_index.main.ConstProp.64bit.panic-unwind.diff

@@ -20,10 +20,10 @@
           _3 = const 2_usize;
 -         _4 = Len(_2);
 -         _5 = Lt(_3, _4);
--         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
+-         assert(move _5, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
 +         _4 = const 5000_usize;
 +         _5 = const true;
-+         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> bb1;
++         assert(const true, "index out of bounds: the length is {} but the index is {}", move _4, _3) -> [success: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/mutable_variable_aggregate_partial_read.main.ConstProp.panic-unwind.diff

@@ -14,7 +14,7 @@
 
       bb0: {
           StorageLive(_1);
-          _1 = foo() -> bb1;
+          _1 = foo() -> [return: bb1, unwind continue];
       }
 
       bb1: {

tests/mir-opt/const_prop/mutable_variable_unprop_assign.main.ConstProp.panic-unwind.diff

@@ -23,7 +23,7 @@
 
       bb0: {
           StorageLive(_1);
-          _1 = foo() -> bb1;
+          _1 = foo() -> [return: bb1, unwind continue];
       }
 
       bb1: {