#[no_drop_flag]

test.ll

%struct.Foo = type { i64 }

define void @_ZN14__extensions__9meth_29568finalize16_d7d397690bb61803_00E({ i64, %tydesc*, i8*, i8*, i8 }*) #1 {
static_allocas:
  br label %1

; <label>:1                                       ; preds = %static_allocas
  br label %return

return:                                           ; preds = %1
  ret void
}

define internal void @_ZN4main16_d7d397690bb61803_00E({ i64, %tydesc*, i8*, i8*, i8 }*) #1 {
static_allocas:
  %1 = alloca %struct.Foo
  br label %2

; <label>:2                                       ; preds = %static_allocas
  %3 = getelementptr inbounds %struct.Foo* %1, i32 0, i32 0
  store i64 1, i64* %3
  br label %4

return:                                           ; preds = %4
  ret void

; <label>:4                                       ; preds = %2
  %5 = bitcast %struct.Foo* %1 to i8*
  call void @_ZN3Foo17_9681d6fdb97ccc5b14glue_drop_2963E({}* null, %tydesc** null, i8* %5)
  br label %return
}

define internal void @_ZN3Foo17_9681d6fdb97ccc5b14glue_drop_2963E({}*, %tydesc**, i8*) #2 {
static_allocas:
  %3 = alloca %struct.Foo*
  br label %4

return:                                           ; preds = %4
  ret void

; <label>:4                                       ; preds = %static_allocas
  %5 = bitcast i8* %2 to %struct.Foo*
  store %struct.Foo* %5, %struct.Foo** %3
  %6 = bitcast %struct.Foo** %3 to { i64, %tydesc*, i8*, i8*, i8 }*
  call void @_ZN14__extensions__9meth_29568finalize16_d7d397690bb61803_00E({ i64, %tydesc*, i8*, i8*, i8 }* %6)
  %7 = getelementptr inbounds %struct.Foo* %5, i32 0, i32 0
  %8 = bitcast %struct.Foo* %5 to i8*
  call void @llvm.memset.p0i8.i64(i8* %8, i8 0, i64 8, i32 8, i1 false)
  br label %return
}

test.rs

#[no_drop_flag]
struct Foo {
    a: uint
}

impl Drop for Foo {
    fn finalize(&self) {
    
    }
}

fn main() {
    let _a = Foo { a: 1 };
}