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// unit-test: ElaborateDrops
// needs-unwind
// this tests move up progration, which is not yet implemented
// EMIT_MIR basic_assignment.main.ElaborateDrops.diff
// EMIT_MIR basic_assignment.main.SimplifyCfg-initial.after.mir
// 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() {
// CHECK-LABEL: fn main(
// CHECK: debug nodrop_x => [[nodrop_x:_.*]];
// CHECK: debug nodrop_y => [[nodrop_y:_.*]];
// CHECK: debug drop_x => [[drop_x:_.*]];
// CHECK: debug drop_y => [[drop_y:_.*]];
// CHECK-NOT: drop([[nodrop_x]])
// CHECK-NOT: drop([[nodrop_y]])
// CHECK-NOT: drop([[drop_x]])
// CHECK: [[drop_tmp:_.*]] = move [[drop_x]];
// CHECK-NOT: drop([[drop_x]])
// CHECK-NOT: drop([[drop_tmp]])
// CHECK: [[drop_y]] = move [[drop_tmp]];
// CHECK-NOT: drop([[drop_x]])
// CHECK-NOT: drop([[drop_tmp]])
// CHECK: drop([[drop_y]])
// CHECK-NOT: drop([[drop_x]])
// CHECK-NOT: drop([[drop_tmp]])
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;
}
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