From 5bece28b096a82bf2a9a273ce43b3122839a1bcb Mon Sep 17 00:00:00 2001 From: Olivier Goffart Date: Sun, 23 May 2021 16:12:01 +0200 Subject: [PATCH] unhinabited_enum_branching: Fix the pass when the enum is taken indirectly If there is a projection on the place of the discriminent, the pass wouldn't trigger --- .../transform/uninhabited_enum_branching.rs | 12 ++-- ...after-uninhabited-enum-branching.after.mir | 70 +++---------------- ...nching2.main.UninhabitedEnumBranching.diff | 6 +- 3 files changed, 19 insertions(+), 69 deletions(-) diff --git a/compiler/rustc_mir/src/transform/uninhabited_enum_branching.rs b/compiler/rustc_mir/src/transform/uninhabited_enum_branching.rs index 465832c89fd..5c6c158d46e 100644 --- a/compiler/rustc_mir/src/transform/uninhabited_enum_branching.rs +++ b/compiler/rustc_mir/src/transform/uninhabited_enum_branching.rs @@ -24,6 +24,7 @@ fn get_discriminant_local(terminator: &TerminatorKind<'_>) -> Option { /// discriminant is read from. Otherwise, returns None. fn get_switched_on_type<'tcx>( block_data: &BasicBlockData<'tcx>, + tcx: TyCtxt<'tcx>, body: &Body<'tcx>, ) -> Option> { 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; diff --git a/src/test/mir-opt/uninhabited_enum_branching2.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir b/src/test/mir-opt/uninhabited_enum_branching2.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir index bb21ca46a70..373be9f174b 100644 --- a/src/test/mir-opt/uninhabited_enum_branching2.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir +++ b/src/test/mir-opt/uninhabited_enum_branching2.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir @@ -30,7 +30,7 @@ fn main() -> () { 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: bb2, otherwise: bb1]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:22:9: 22:20 } bb1: { @@ -44,35 +44,10 @@ fn main() -> () { // + 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 + goto -> bb3; // 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 @@ -83,18 +58,18 @@ fn main() -> () { // + 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 + goto -> bb3; // scope 1 at $DIR/uninhabited_enum_branching2.rs:21:5: 26:6 } - bb5: { + 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) -> [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: bb5, otherwise: bb4]; // scope 1 at $DIR/uninhabited_enum_branching2.rs:29:9: 29:20 } - bb6: { + 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 @@ -105,35 +80,10 @@ fn main() -> () { // + 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 + goto -> bb6; // 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: { + 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 @@ -144,10 +94,10 @@ fn main() -> () { // + 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 + goto -> bb6; // scope 1 at $DIR/uninhabited_enum_branching2.rs:28:5: 33:6 } - bb10: { + 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 diff --git a/src/test/mir-opt/uninhabited_enum_branching2.main.UninhabitedEnumBranching.diff b/src/test/mir-opt/uninhabited_enum_branching2.main.UninhabitedEnumBranching.diff index 387ab97dab4..f9488bae4c8 100644 --- a/src/test/mir-opt/uninhabited_enum_branching2.main.UninhabitedEnumBranching.diff +++ b/src/test/mir-opt/uninhabited_enum_branching2.main.UninhabitedEnumBranching.diff @@ -31,7 +31,8 @@ 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) -> [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: { @@ -92,7 +93,8 @@ 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) -> [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: {