diff options
| -rw-r--r-- | src/librustc_mir/transform/simplify_try.rs | 8 | ||||
| -rw-r--r-- | src/test/mir-opt/simplify-arm-identity.rs | 75 | ||||
| -rw-r--r-- | src/test/ui/issues/issue-66851.rs | 20 |
3 files changed, 102 insertions, 1 deletions
diff --git a/src/librustc_mir/transform/simplify_try.rs b/src/librustc_mir/transform/simplify_try.rs index de5c2ebb571..9dc5daa9b07 100644 --- a/src/librustc_mir/transform/simplify_try.rs +++ b/src/librustc_mir/transform/simplify_try.rs @@ -34,7 +34,8 @@ pub struct SimplifyArmIdentity; impl<'tcx> MirPass<'tcx> for SimplifyArmIdentity { fn run_pass(&self, _: TyCtxt<'tcx>, _: MirSource<'tcx>, body: &mut Body<'tcx>) { - for bb in body.basic_blocks_mut() { + let (basic_blocks, local_decls) = body.basic_blocks_and_local_decls_mut(); + for bb in basic_blocks { // Need 3 statements: let (s0, s1, s2) = match &mut *bb.statements { [s0, s1, s2] => (s0, s1, s2), @@ -51,7 +52,12 @@ impl<'tcx> MirPass<'tcx> for SimplifyArmIdentity { Some(x) => x, }; if local_tmp_s0 != local_tmp_s1 + // The field-and-variant information match up. || vf_s0 != vf_s1 + // Source and target locals have the same type. + // FIXME(Centril | oli-obk): possibly relax to same layout? + || local_decls[local_0].ty != local_decls[local_1].ty + // We're setting the discriminant of `local_0` to this variant. || Some((local_0, vf_s0.var_idx)) != match_set_discr(s2) { continue; diff --git a/src/test/mir-opt/simplify-arm-identity.rs b/src/test/mir-opt/simplify-arm-identity.rs new file mode 100644 index 00000000000..a8fa64255fb --- /dev/null +++ b/src/test/mir-opt/simplify-arm-identity.rs @@ -0,0 +1,75 @@ +// Checks that `SimplifyArmIdentity` is not applied if enums have incompatible layouts. +// Regression test for issue #66856. +// +// compile-flags: -Zmir-opt-level=2 + +enum Src { + Foo(u8), + Bar, +} + +enum Dst { + Foo(u8), +} + +fn main() { + let e: Src = Src::Foo(0); + let _: Dst = match e { + Src::Foo(x) => Dst::Foo(x), + Src::Bar => Dst::Foo(0), + }; +} + +// END RUST SOURCE +// START rustc.main.SimplifyArmIdentity.before.mir +// fn main() -> () { +// ... +// bb0: { +// StorageLive(_1); +// ((_1 as Foo).0: u8) = const 0u8; +// discriminant(_1) = 0; +// StorageLive(_2); +// _3 = discriminant(_1); +// switchInt(move _3) -> [0isize: bb3, 1isize: bb1, otherwise: bb2]; +// } +// bb1: { +// ((_2 as Foo).0: u8) = const 0u8; +// discriminant(_2) = 0; +// goto -> bb4; +// } +// ... +// bb3: { +// _4 = ((_1 as Foo).0: u8); +// ((_2 as Foo).0: u8) = move _4; +// discriminant(_2) = 0; +// goto -> bb4; +// } +// ... +// } +// END rustc.main.SimplifyArmIdentity.before.mir +// START rustc.main.SimplifyArmIdentity.after.mir +// fn main() -> () { +// ... +// bb0: { +// StorageLive(_1); +// ((_1 as Foo).0: u8) = const 0u8; +// discriminant(_1) = 0; +// StorageLive(_2); +// _3 = discriminant(_1); +// switchInt(move _3) -> [0isize: bb3, 1isize: bb1, otherwise: bb2]; +// } +// bb1: { +// ((_2 as Foo).0: u8) = const 0u8; +// discriminant(_2) = 0; +// goto -> bb4; +// } +// ... +// bb3: { +// _4 = ((_1 as Foo).0: u8); +// ((_2 as Foo).0: u8) = move _4; +// discriminant(_2) = 0; +// goto -> bb4; +// } +// ... +// } +// END rustc.main.SimplifyArmIdentity.after.mir diff --git a/src/test/ui/issues/issue-66851.rs b/src/test/ui/issues/issue-66851.rs new file mode 100644 index 00000000000..72d62a30a33 --- /dev/null +++ b/src/test/ui/issues/issue-66851.rs @@ -0,0 +1,20 @@ +// This used to mis-compile because the mir-opt `SimplifyArmIdentity` +// did not check that the types matched up in the `Ok(r)` branch. +// +// run-pass +// compile-flags: -Zmir-opt-level=2 + +#[derive(Debug, PartialEq, Eq)] +enum SpecialsRes { Res(u64) } + +fn e103() -> SpecialsRes { + if let Ok(r) = "1".parse() { + SpecialsRes::Res(r) + } else { + SpecialsRes::Res(42) + } +} + +fn main() { + assert_eq!(e103(), SpecialsRes::Res(1)); +} |