ac97: Add top level unit test

Check that the device can be created. This test would have caught the
bug with adding pci bars.

Change-Id: Ib0cc2edf0d8d1b2d95d9c3588ac325b5da886603
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1497738
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>

devices/src/pci/ac97.rs

@@ -210,3 +210,24 @@ impl PciDevice for Ac97Dev {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use audio_streams::DummyStreamSource;
+    use resources::AddressRanges;
+    use sys_util::GuestAddress;
+
+    #[test]
+    fn create() {
+        let mem = GuestMemory::new(&[(GuestAddress(0u64), 4 * 1024 * 1024)]).unwrap();
+        let mut ac97_dev = Ac97Dev::new(mem, Box::new(DummyStreamSource::new()));
+        let mut allocator = AddressRanges::new()
+            .add_io_addresses(0x1000_0000, 0x1000_0000)
+            .add_mmio_addresses(0x2000_0000, 0x1000_0000)
+            .add_device_addresses(0x3000_0000, 0x1000_0000)
+            .create_allocator(5, false)
+            .unwrap();
+        assert!(ac97_dev.allocate_io_bars(&mut allocator).is_ok());
+    }
+}