codegen: Add integration tests for destructors.

Author: emilio

bindgen-integration/cpp/Test.cc

@@ -21,6 +21,15 @@ Test::Test(double foo)
   , m_double(foo)
 {}
 
+AutoRestoreBool::AutoRestoreBool(bool* ptr)
+  : m_ptr(ptr)
+  , m_value(*ptr)
+{}
+
+AutoRestoreBool::~AutoRestoreBool() {
+  *m_ptr = m_value;
+}
+
 namespace bitfields {
 
 bool
@@ -47,4 +56,4 @@ Third::assert(int first, bool second, ItemKind third)
         kind == third;
 }
 
-}
+} // namespace bitfields

bindgen-integration/cpp/Test.h

@@ -64,3 +64,11 @@ struct Third {
 };
 
 } // namespace bitfields
+
+struct AutoRestoreBool {
+  bool* m_ptr;
+  bool m_value;
+
+  AutoRestoreBool(bool*);
+  ~AutoRestoreBool();
+};

bindgen-integration/src/lib.rs

@@ -101,3 +101,21 @@ fn test_bitfields_third() {
                      bindings::bitfields::ItemKind::ITEM_KIND_TRES)
     });
 }
+
+impl Drop for bindings::AutoRestoreBool {
+    fn drop(&mut self) {
+        unsafe { bindings::AutoRestoreBool::destruct(self) }
+    }
+}
+
+#[test]
+fn test_destructors() {
+    let mut v = true;
+
+    {
+        let auto_restore = unsafe { bindings::AutoRestoreBool::new(&mut v) };
+        v = false;
+    }
+
+    assert!(v, "Should've been restored when going out of scope");
+}