| // this tests move up progration, which is not yet implemented |
| |
| // Check codegen for assignments (`a = b`) where the left-hand-side is |
| // not yet initialized. Assignments tend to be absent in simple code, |
| // so subtle breakage in them can leave a quite hard-to-find trail of |
| // destruction. |
| |
| fn main() { |
| let nodrop_x = false; |
| let nodrop_y; |
| |
| // Since boolean does not require drop, this can be a simple |
| // assignment: |
| nodrop_y = nodrop_x; |
| |
| let drop_x : Option<Box<u32>> = None; |
| let drop_y; |
| |
| // Since the type of `drop_y` has drop, we generate a `replace` |
| // terminator: |
| drop_y = drop_x; |
| } |
| |
| // END RUST SOURCE |
| // START rustc.main.SimplifyCfg-initial.after.mir |
| // bb0: { |
| // StorageLive(_1); |
| // _1 = const false; |
| // FakeRead(ForLet, _1); |
| // StorageLive(_2); |
| // StorageLive(_3); |
| // _3 = _1; |
| // _2 = move _3; |
| // StorageDead(_3); |
| // StorageLive(_4); |
| // _4 = std::option::Option::<std::boxed::Box<u32>>::None; |
| // FakeRead(ForLet, _4); |
| // AscribeUserType(_4, o, UserTypeProjection { base: UserType(1), projs: [] }); |
| // StorageLive(_5); |
| // StorageLive(_6); |
| // _6 = move _4; |
| // replace(_5 <- move _6) -> [return: bb2, unwind: bb5]; |
| // } |
| // ... |
| // bb2: { |
| // drop(_6) -> [return: bb6, unwind: bb4]; |
| // } |
| // ... |
| // bb5 (cleanup): { |
| // drop(_6) -> bb4; |
| // } |
| // END rustc.main.SimplifyCfg-initial.after.mir |