FileCheck box_expr.rs

This check is made `needs-unwind`, as the panic=abort case is a strictly
simpler version.

Author: cjgillot

tests/mir-opt/box_expr.main.ElaborateDrops.before.panic-unwind.mir renamed to tests/mir-opt/box_expr.main.ElaborateDrops.before.mir

@@ -1,10 +1,22 @@
-// skip-filecheck
-// EMIT_MIR_FOR_EACH_PANIC_STRATEGY
+// unit-test: ElaborateDrops
+// needs-unwind
 
 #![feature(rustc_attrs, stmt_expr_attributes)]
 
 // EMIT_MIR box_expr.main.ElaborateDrops.before.mir
 fn main() {
+    // CHECK-LABEL: fn main(
+    // CHECK:   [[box:_.*]] = ShallowInitBox(
+    // CHECK:   [[ptr:_.*]] = ((([[box]].0: std::ptr::Unique<S>).0: std::ptr::NonNull<S>).0: *const S);
+    // CHECK:   (*[[ptr]]) = S::new() -> [return: [[ret:bb.*]], unwind: [[unwind:bb.*]]];
+    // CHECK: [[ret]]: {
+    // CHECK:   [[box2:_.*]] = move [[box]];
+    // CHECK:   [[box3:_.*]] = move [[box2]];
+    // CHECK:   std::mem::drop::<Box<S>>(move [[box3]])
+    // CHECK: [[unwind]] (cleanup): {
+    // CHECK:   [[boxref:_.*]] = &mut [[box]];
+    // CHECK:   <Box<S> as Drop>::drop(move [[boxref]])
+
     let x = #[rustc_box]
     Box::new(S::new());
     drop(x);