meson: Remove -Wno-unused-parameter

We build libcamera with -Wno-unused-parameter and this doesn't cause
much issue internally. However, it prevents catching unused parameters
in inline functions defined in public headers. This can lead to
compilation warnings for applications compiled without
-Wno-unused-parameter.

To catch those issues, remove -Wno-unused-parameter and fix all the
related warnings with [[maybe_unused]].

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/android/camera3_hal.cpp

@@ -32,20 +32,23 @@ static int hal_get_camera_info(int id, struct camera_info *info)
 	return cameraManager.getCameraInfo(id, info);
 }
 
-static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)
+static int hal_set_callbacks([[maybe_unused]] const camera_module_callbacks_t *callbacks)
 {
 	cameraManager.setCallbacks(callbacks);
 
 	return 0;
 }
 
-static int hal_open_legacy(const struct hw_module_t *module, const char *id,
-			   uint32_t halVersion, struct hw_device_t **device)
+static int hal_open_legacy([[maybe_unused]] const struct hw_module_t *module,
+			   [[maybe_unused]] const char *id,
+			   [[maybe_unused]] uint32_t halVersion,
+			   [[maybe_unused]] struct hw_device_t **device)
 {
 	return -ENOSYS;
 }
 
-static int hal_set_torch_mode(const char *camera_id, bool enabled)
+static int hal_set_torch_mode([[maybe_unused]] const char *camera_id,
+			      [[maybe_unused]] bool enabled)
 {
 	return -ENOSYS;
 }

src/android/camera_device.cpp

@@ -1548,8 +1548,9 @@ void CameraDevice::notifyError(uint32_t frameNumber, camera3_stream_t *stream)
 /*
  * Produce a set of fixed result metadata.
  */
-std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number,
-								int64_t timestamp)
+std::unique_ptr<CameraMetadata>
+CameraDevice::getResultMetadata([[maybe_unused]] int frame_number,
+				int64_t timestamp)
 {
 	/*
 	 * \todo Keep this in sync with the actual number of entries.

src/android/camera_ops.cpp

@@ -61,11 +61,12 @@ static int hal_dev_process_capture_request(const struct camera3_device *dev,
 	return camera->processCaptureRequest(request);
 }
 
-static void hal_dev_dump(const struct camera3_device *dev, int fd)
+static void hal_dev_dump([[maybe_unused]] const struct camera3_device *dev,
+			 [[maybe_unused]] int fd)
 {
 }
 
-static int hal_dev_flush(const struct camera3_device *dev)
+static int hal_dev_flush([[maybe_unused]] const struct camera3_device *dev)
 {
 	return 0;
 }