Auto merge of #85603 - ogoffart:fix-uninhabited-enum-branching-pass, r=wesleywiser

Fix uninhabited enum branching pass

when the discriminant is taken with some projection.
This commit is contained in:
bors 2021-06-25 15:35:47 +00:00
commit f726dbe934
4 changed files with 305 additions and 7 deletions

View File

@ -24,6 +24,7 @@ fn get_discriminant_local(terminator: &TerminatorKind<'_>) -> Option<Local> {
/// discriminant is read from. Otherwise, returns None.
fn get_switched_on_type<'tcx>(
block_data: &BasicBlockData<'tcx>,
tcx: TyCtxt<'tcx>,
body: &Body<'tcx>,
) -> Option<Ty<'tcx>> {
let terminator = block_data.terminator();
@ -36,12 +37,9 @@ fn get_switched_on_type<'tcx>(
if let Some(StatementKind::Assign(box (l, Rvalue::Discriminant(place)))) = stmt_before_term
{
if l.as_local() == Some(local) {
if let Some(r_local) = place.as_local() {
let ty = body.local_decls[r_local].ty;
if ty.is_enum() {
return Some(ty);
}
let ty = place.ty(body, tcx).ty;
if ty.is_enum() {
return Some(ty);
}
}
}
@ -86,7 +84,7 @@ impl<'tcx> MirPass<'tcx> for UninhabitedEnumBranching {
trace!("processing block {:?}", bb);
let discriminant_ty =
if let Some(ty) = get_switched_on_type(&body.basic_blocks()[bb], body) {
if let Some(ty) = get_switched_on_type(&body.basic_blocks()[bb], tcx, body) {
ty
} else {
continue;

View File

@ -0,0 +1,106 @@
// MIR for `main` after SimplifyCfg-after-uninhabited-enum-branching
fn main() -> () {
let mut _0: (); // return place in scope 0 at $DIR/uninhabited_enum_branching2.rs:18:11: 18:11
let _1: Plop; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:19:9: 19:13
let mut _2: Test1; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:19:38: 19:46
let _3: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
let mut _4: &Test1; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:21:11: 21:22
let mut _5: isize; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
let _6: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:23:24: 23:34
let _7: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
let _8: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
let _9: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
let mut _10: isize; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
let _11: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:30:24: 30:34
let _12: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
let _13: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
scope 1 {
debug plop => _1; // in scope 1 at $DIR/uninhabited_enum_branching2.rs:19:9: 19:13
}
bb0: {
StorageLive(_1); // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:9: 19:13
StorageLive(_2); // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:38: 19:46
discriminant(_2) = 2; // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:38: 19:46
(_1.0: u32) = const 51_u32; // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:16: 19:48
(_1.1: Test1) = move _2; // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:16: 19:48
StorageDead(_2); // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:47: 19:48
StorageLive(_3); // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
StorageLive(_4); // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:11: 21:22
_4 = &(_1.1: Test1); // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:11: 21:22
_5 = discriminant((*_4)); // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
switchInt(move _5) -> [2_isize: bb2, otherwise: bb1]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
}
bb1: {
StorageLive(_8); // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
_8 = const "D"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_3 = &(*_8); // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
StorageDead(_8); // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:23: 25:24
goto -> bb3; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
}
bb2: {
StorageLive(_7); // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
_7 = const "C"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_3 = &(*_7); // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
StorageDead(_7); // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:23: 24:24
goto -> bb3; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
}
bb3: {
StorageDead(_4); // scope 1 at $DIR/uninhabited_enum_branching2.rs:26:6: 26:7
StorageDead(_3); // scope 1 at $DIR/uninhabited_enum_branching2.rs:26:6: 26:7
StorageLive(_9); // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
_10 = discriminant((_1.1: Test1)); // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
switchInt(move _10) -> [2_isize: bb5, otherwise: bb4]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
}
bb4: {
StorageLive(_13); // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
_13 = const "D"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_9 = &(*_13); // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
StorageDead(_13); // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:23: 32:24
goto -> bb6; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
}
bb5: {
StorageLive(_12); // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
_12 = const "C"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_9 = &(*_12); // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
StorageDead(_12); // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:23: 31:24
goto -> bb6; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
}
bb6: {
StorageDead(_9); // scope 1 at $DIR/uninhabited_enum_branching2.rs:33:6: 33:7
_0 = const (); // scope 0 at $DIR/uninhabited_enum_branching2.rs:18:11: 34:2
StorageDead(_1); // scope 0 at $DIR/uninhabited_enum_branching2.rs:34:1: 34:2
return; // scope 0 at $DIR/uninhabited_enum_branching2.rs:34:2: 34:2
}
}

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@ -0,0 +1,160 @@
- // MIR for `main` before UninhabitedEnumBranching
+ // MIR for `main` after UninhabitedEnumBranching
fn main() -> () {
let mut _0: (); // return place in scope 0 at $DIR/uninhabited_enum_branching2.rs:18:11: 18:11
let _1: Plop; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:19:9: 19:13
let mut _2: Test1; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:19:38: 19:46
let _3: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
let mut _4: &Test1; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:21:11: 21:22
let mut _5: isize; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
let _6: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:23:24: 23:34
let _7: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
let _8: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
let _9: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
let mut _10: isize; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
let _11: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:30:24: 30:34
let _12: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
let _13: &str; // in scope 0 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
scope 1 {
debug plop => _1; // in scope 1 at $DIR/uninhabited_enum_branching2.rs:19:9: 19:13
}
bb0: {
StorageLive(_1); // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:9: 19:13
StorageLive(_2); // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:38: 19:46
discriminant(_2) = 2; // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:38: 19:46
(_1.0: u32) = const 51_u32; // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:16: 19:48
(_1.1: Test1) = move _2; // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:16: 19:48
StorageDead(_2); // scope 0 at $DIR/uninhabited_enum_branching2.rs:19:47: 19:48
StorageLive(_3); // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
StorageLive(_4); // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:11: 21:22
_4 = &(_1.1: Test1); // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:11: 21:22
_5 = discriminant((*_4)); // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
- switchInt(move _5) -> [0_isize: bb2, 1_isize: bb3, 2_isize: bb4, otherwise: bb1]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
+ switchInt(move _5) -> [2_isize: bb4, otherwise: bb1]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20
}
bb1: {
StorageLive(_8); // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
_8 = const "D"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_3 = &(*_8); // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:21: 25:24
StorageDead(_8); // scope 1 at $DIR/uninhabited_enum_branching2.rs:25:23: 25:24
goto -> bb5; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
}
bb2: {
_3 = const "A(Empty)"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:24: 22:34
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [65, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:22:24: 22:34
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [65, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 }) }
goto -> bb5; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
}
bb3: {
StorageLive(_6); // scope 1 at $DIR/uninhabited_enum_branching2.rs:23:24: 23:34
_6 = const "B(Empty)"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:23:24: 23:34
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [66, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:23:24: 23:34
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [66, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 }) }
_3 = &(*_6); // scope 1 at $DIR/uninhabited_enum_branching2.rs:23:24: 23:34
StorageDead(_6); // scope 1 at $DIR/uninhabited_enum_branching2.rs:23:33: 23:34
goto -> bb5; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
}
bb4: {
StorageLive(_7); // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
_7 = const "C"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_3 = &(*_7); // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:21: 24:24
StorageDead(_7); // scope 1 at $DIR/uninhabited_enum_branching2.rs:24:23: 24:24
goto -> bb5; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6
}
bb5: {
StorageDead(_4); // scope 1 at $DIR/uninhabited_enum_branching2.rs:26:6: 26:7
StorageDead(_3); // scope 1 at $DIR/uninhabited_enum_branching2.rs:26:6: 26:7
StorageLive(_9); // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
_10 = discriminant((_1.1: Test1)); // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
- switchInt(move _10) -> [0_isize: bb7, 1_isize: bb8, 2_isize: bb9, otherwise: bb6]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
+ switchInt(move _10) -> [2_isize: bb9, otherwise: bb6]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20
}
bb6: {
StorageLive(_13); // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
_13 = const "D"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [68], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_9 = &(*_13); // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:21: 32:24
StorageDead(_13); // scope 1 at $DIR/uninhabited_enum_branching2.rs:32:23: 32:24
goto -> bb10; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
}
bb7: {
_9 = const "A(Empty)"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:24: 29:34
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [65, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:29:24: 29:34
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [65, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 }) }
goto -> bb10; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
}
bb8: {
StorageLive(_11); // scope 1 at $DIR/uninhabited_enum_branching2.rs:30:24: 30:34
_11 = const "B(Empty)"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:30:24: 30:34
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [66, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:30:24: 30:34
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [66, 40, 69, 109, 112, 116, 121, 41], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [255], len: Size { raw: 8 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 8 }) }
_9 = &(*_11); // scope 1 at $DIR/uninhabited_enum_branching2.rs:30:24: 30:34
StorageDead(_11); // scope 1 at $DIR/uninhabited_enum_branching2.rs:30:33: 30:34
goto -> bb10; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
}
bb9: {
StorageLive(_12); // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
_12 = const "C"; // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
// ty::Const
// + ty: &str
// + val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 })
// mir::Constant
// + span: $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [67], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1], len: Size { raw: 1 } }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 1 }) }
_9 = &(*_12); // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:21: 31:24
StorageDead(_12); // scope 1 at $DIR/uninhabited_enum_branching2.rs:31:23: 31:24
goto -> bb10; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6
}
bb10: {
StorageDead(_9); // scope 1 at $DIR/uninhabited_enum_branching2.rs:33:6: 33:7
_0 = const (); // scope 0 at $DIR/uninhabited_enum_branching2.rs:18:11: 34:2
StorageDead(_1); // scope 0 at $DIR/uninhabited_enum_branching2.rs:34:1: 34:2
return; // scope 0 at $DIR/uninhabited_enum_branching2.rs:34:2: 34:2
}
}

View File

@ -0,0 +1,34 @@
enum Empty { }
// test matching an enum with uninhabited variants
enum Test1 {
A(Empty),
B(Empty),
C,
D,
}
struct Plop {
xx: u32,
test1: Test1,
}
// EMIT_MIR uninhabited_enum_branching2.main.UninhabitedEnumBranching.diff
// EMIT_MIR uninhabited_enum_branching2.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir
fn main() {
let plop = Plop { xx: 51, test1: Test1::C };
match &plop.test1 {
Test1::A(_) => "A(Empty)",
Test1::B(_) => "B(Empty)",
Test1::C => "C",
Test1::D => "D",
};
match plop.test1 {
Test1::A(_) => "A(Empty)",
Test1::B(_) => "B(Empty)",
Test1::C => "C",
Test1::D => "D",
};
}