Code clean for libcameraservice

Cleaning compile warnings "variable 'XX' set but not used":
1. Remove the variables which are obviously not used;
2. Add "[[maybe_unused]]" to variable declaration of the ones
   which are potentially used.

For the unused function parameters which were cast by "(void)":
We have changed them to the C++17 attribute "[[maybe_unused]]".
This seems not that necessary but it avoids redundant code lines.

Test: mmm frameworks/av/services/camera/libcameraservice,
      presubmit check.

Change-Id: Ia68b78c01f8254d76be81b1ce98d2a5c3d7eea46
Signed-off-by: Jing Mike <jingyangliu@eswincomputing.com>
diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index 2a04658..8bfa588 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -3714,8 +3714,7 @@
 // ----------------------------------------------------------------------------
 
 void CameraService::Client::notifyError(int32_t errorCode,
-        const CaptureResultExtras& resultExtras) {
-    (void) resultExtras;
+        [[maybe_unused]] const CaptureResultExtras& resultExtras) {
     if (mRemoteCallback != NULL) {
         int32_t api1ErrorCode = CAMERA_ERROR_RELEASED;
         if (errorCode == hardware::camera2::ICameraDeviceCallbacks::ERROR_CAMERA_DISABLED) {
diff --git a/services/camera/libcameraservice/api1/Camera2Client.cpp b/services/camera/libcameraservice/api1/Camera2Client.cpp
index 0887ced..8e3f609 100644
--- a/services/camera/libcameraservice/api1/Camera2Client.cpp
+++ b/services/camera/libcameraservice/api1/Camera2Client.cpp
@@ -1332,21 +1332,18 @@
             || l.mParameters.state == Parameters::VIDEO_SNAPSHOT);
 }
 
-void Camera2Client::releaseRecordingFrame(const sp<IMemory>& mem) {
-    (void)mem;
+void Camera2Client::releaseRecordingFrame([[maybe_unused]] const sp<IMemory>& mem) {
     ATRACE_CALL();
     ALOGW("%s: Not supported in buffer queue mode.", __FUNCTION__);
 }
 
-void Camera2Client::releaseRecordingFrameHandle(native_handle_t *handle) {
-    (void)handle;
+void Camera2Client::releaseRecordingFrameHandle([[maybe_unused]] native_handle_t *handle) {
     ATRACE_CALL();
     ALOGW("%s: Not supported in buffer queue mode.", __FUNCTION__);
 }
 
 void Camera2Client::releaseRecordingFrameHandleBatch(
-        const std::vector<native_handle_t*>& handles) {
-    (void)handles;
+        [[maybe_unused]] const std::vector<native_handle_t*>& handles) {
     ATRACE_CALL();
     ALOGW("%s: Not supported in buffer queue mode.", __FUNCTION__);
 }
diff --git a/services/camera/libcameraservice/api2/CameraDeviceClient.cpp b/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
index bc76397..202599b 100644
--- a/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
+++ b/services/camera/libcameraservice/api2/CameraDeviceClient.cpp
@@ -61,7 +61,7 @@
         bool systemNativeClient,
         const std::optional<String16>& clientFeatureId,
         const String8& cameraId,
-        int api1CameraId,
+        [[maybe_unused]] int api1CameraId,
         int cameraFacing,
         int sensorOrientation,
         int clientPid,
@@ -81,8 +81,6 @@
             servicePid,
             overrideToPortrait),
     mRemoteCallback(remoteCallback) {
-    // We don't need it for API2 clients, but Camera2ClientBase requires it.
-    (void) api1CameraId;
 }
 
 // Interface used by CameraService
diff --git a/services/camera/libcameraservice/api2/CameraOfflineSessionClient.cpp b/services/camera/libcameraservice/api2/CameraOfflineSessionClient.cpp
index 2cb3397..acc805a 100644
--- a/services/camera/libcameraservice/api2/CameraOfflineSessionClient.cpp
+++ b/services/camera/libcameraservice/api2/CameraOfflineSessionClient.cpp
@@ -309,26 +309,20 @@
     finishCameraStreamingOps();
 }
 
-void CameraOfflineSessionClient::notifyAutoFocus(uint8_t newState, int triggerId) {
-    (void)newState;
-    (void)triggerId;
-
+void CameraOfflineSessionClient::notifyAutoFocus([[maybe_unused]] uint8_t newState,
+                [[maybe_unused]] int triggerId) {
     ALOGV("%s: Autofocus state now %d, last trigger %d",
           __FUNCTION__, newState, triggerId);
 }
 
-void CameraOfflineSessionClient::notifyAutoExposure(uint8_t newState, int triggerId) {
-    (void)newState;
-    (void)triggerId;
-
+void CameraOfflineSessionClient::notifyAutoExposure([[maybe_unused]] uint8_t newState,
+                [[maybe_unused]] int triggerId) {
     ALOGV("%s: Autoexposure state now %d, last trigger %d",
             __FUNCTION__, newState, triggerId);
 }
 
-void CameraOfflineSessionClient::notifyAutoWhitebalance(uint8_t newState, int triggerId) {
-    (void)newState;
-    (void)triggerId;
-
+void CameraOfflineSessionClient::notifyAutoWhitebalance([[maybe_unused]] uint8_t newState,
+                [[maybe_unused]] int triggerId) {
     ALOGV("%s: Auto-whitebalance state now %d, last trigger %d", __FUNCTION__, newState,
             triggerId);
 }
diff --git a/services/camera/libcameraservice/common/Camera2ClientBase.cpp b/services/camera/libcameraservice/common/Camera2ClientBase.cpp
index ad24392..71d0f9e 100644
--- a/services/camera/libcameraservice/common/Camera2ClientBase.cpp
+++ b/services/camera/libcameraservice/common/Camera2ClientBase.cpp
@@ -380,50 +380,38 @@
 }
 
 template <typename TClientBase>
-void Camera2ClientBase<TClientBase>::notifyShutter(const CaptureResultExtras& resultExtras,
-                                                   nsecs_t timestamp) {
-    (void)resultExtras;
-    (void)timestamp;
-
+void Camera2ClientBase<TClientBase>::notifyShutter(
+                [[maybe_unused]] const CaptureResultExtras& resultExtras,
+                [[maybe_unused]] nsecs_t timestamp) {
     ALOGV("%s: Shutter notification for request id %" PRId32 " at time %" PRId64,
             __FUNCTION__, resultExtras.requestId, timestamp);
 }
 
 template <typename TClientBase>
-void Camera2ClientBase<TClientBase>::notifyAutoFocus(uint8_t newState,
-                                                     int triggerId) {
-    (void)newState;
-    (void)triggerId;
-
+void Camera2ClientBase<TClientBase>::notifyAutoFocus([[maybe_unused]] uint8_t newState,
+                                                     [[maybe_unused]] int triggerId) {
     ALOGV("%s: Autofocus state now %d, last trigger %d",
           __FUNCTION__, newState, triggerId);
 
 }
 
 template <typename TClientBase>
-void Camera2ClientBase<TClientBase>::notifyAutoExposure(uint8_t newState,
-                                                        int triggerId) {
-    (void)newState;
-    (void)triggerId;
-
+void Camera2ClientBase<TClientBase>::notifyAutoExposure([[maybe_unused]] uint8_t newState,
+                                                        [[maybe_unused]] int triggerId) {
     ALOGV("%s: Autoexposure state now %d, last trigger %d",
             __FUNCTION__, newState, triggerId);
 }
 
 template <typename TClientBase>
-void Camera2ClientBase<TClientBase>::notifyAutoWhitebalance(uint8_t newState,
-                                                            int triggerId) {
-    (void)newState;
-    (void)triggerId;
-
+void Camera2ClientBase<TClientBase>::notifyAutoWhitebalance(
+                [[maybe_unused]] uint8_t newState,
+                [[maybe_unused]] int triggerId) {
     ALOGV("%s: Auto-whitebalance state now %d, last trigger %d",
             __FUNCTION__, newState, triggerId);
 }
 
 template <typename TClientBase>
-void Camera2ClientBase<TClientBase>::notifyPrepared(int streamId) {
-    (void)streamId;
-
+void Camera2ClientBase<TClientBase>::notifyPrepared([[maybe_unused]] int streamId) {
     ALOGV("%s: Stream %d now prepared",
             __FUNCTION__, streamId);
 }
@@ -435,9 +423,8 @@
 }
 
 template <typename TClientBase>
-void Camera2ClientBase<TClientBase>::notifyRepeatingRequestError(long lastFrameNumber) {
-    (void)lastFrameNumber;
-
+void Camera2ClientBase<TClientBase>::notifyRepeatingRequestError(
+            [[maybe_unused]] long lastFrameNumber) {
     ALOGV("%s: Repeating request was stopped. Last frame number is %ld",
             __FUNCTION__, lastFrameNumber);
 }
diff --git a/services/camera/libcameraservice/common/CameraProviderManager.cpp b/services/camera/libcameraservice/common/CameraProviderManager.cpp
index 3aab0b1..c72986d 100644
--- a/services/camera/libcameraservice/common/CameraProviderManager.cpp
+++ b/services/camera/libcameraservice/common/CameraProviderManager.cpp
@@ -1858,13 +1858,12 @@
 CameraProviderManager::ProviderInfo::ProviderInfo(
         const std::string &providerName,
         const std::string &providerInstance,
-        CameraProviderManager *manager) :
+        [[maybe_unused]] CameraProviderManager *manager) :
         mProviderName(providerName),
         mProviderInstance(providerInstance),
         mProviderTagid(generateVendorTagId(providerName)),
         mUniqueDeviceCount(0),
         mManager(manager) {
-    (void) mManager;
 }
 
 const std::string& CameraProviderManager::ProviderInfo::getType() const {
diff --git a/services/camera/libcameraservice/common/CameraProviderManager.h b/services/camera/libcameraservice/common/CameraProviderManager.h
index e8d9a37..8d60afd 100644
--- a/services/camera/libcameraservice/common/CameraProviderManager.h
+++ b/services/camera/libcameraservice/common/CameraProviderManager.h
@@ -572,17 +572,15 @@
                     hardware::CameraInfo *info) const = 0;
             virtual bool isAPI1Compatible() const = 0;
             virtual status_t dumpState(int fd) = 0;
-            virtual status_t getCameraCharacteristics(bool overrideForPerfClass,
-                    CameraMetadata *characteristics, bool overrideToPortrait) {
-                (void) overrideForPerfClass;
-                (void) characteristics;
-                (void) overrideToPortrait;
+            virtual status_t getCameraCharacteristics(
+                    [[maybe_unused]] bool overrideForPerfClass,
+                    [[maybe_unused]] CameraMetadata *characteristics,
+                    [[maybe_unused]] bool overrideToPortrait) {
                 return INVALID_OPERATION;
             }
-            virtual status_t getPhysicalCameraCharacteristics(const std::string& physicalCameraId,
-                    CameraMetadata *characteristics) const {
-                (void) physicalCameraId;
-                (void) characteristics;
+            virtual status_t getPhysicalCameraCharacteristics(
+                    [[maybe_unused]] const std::string& physicalCameraId,
+                    [[maybe_unused]] CameraMetadata *characteristics) const {
                 return INVALID_OPERATION;
             }
 
diff --git a/services/camera/libcameraservice/common/hidl/HidlProviderInfo.cpp b/services/camera/libcameraservice/common/hidl/HidlProviderInfo.cpp
index 15aa5a5..fec7f05 100644
--- a/services/camera/libcameraservice/common/hidl/HidlProviderInfo.cpp
+++ b/services/camera/libcameraservice/common/hidl/HidlProviderInfo.cpp
@@ -442,8 +442,7 @@
 }
 
 void HidlProviderInfo::serviceDied(uint64_t cookie,
-        const wp<hidl::base::V1_0::IBase>& who) {
-    (void) who;
+        [[maybe_unused]] const wp<hidl::base::V1_0::IBase>& who) {
     ALOGI("Camera provider '%s' has died; removing it", mProviderInstance.c_str());
     if (cookie != mId) {
         ALOGW("%s: Unexpected serviceDied cookie %" PRIu64 ", expected %" PRIu32,
diff --git a/services/camera/libcameraservice/device3/Camera3BufferManager.cpp b/services/camera/libcameraservice/device3/Camera3BufferManager.cpp
index a556200..2ac38d5 100644
--- a/services/camera/libcameraservice/device3/Camera3BufferManager.cpp
+++ b/services/camera/libcameraservice/device3/Camera3BufferManager.cpp
@@ -451,10 +451,9 @@
     return OK;
 }
 
-void Camera3BufferManager::dump(int fd, const Vector<String16>& args) const {
+void Camera3BufferManager::dump(int fd, [[maybe_unused]] const Vector<String16>& args) const {
     Mutex::Autolock l(mLock);
 
-    (void) args;
     String8 lines;
     lines.appendFormat("      Total stream sets: %zu\n", mStreamSetMap.size());
     for (size_t i = 0; i < mStreamSetMap.size(); i++) {
diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index 5e7fe7f..9a627f3 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -497,9 +497,8 @@
     return BAD_VALUE;
 }
 
-status_t Camera3Device::dump(int fd, const Vector<String16> &args) {
+status_t Camera3Device::dump(int fd, [[maybe_unused]] const Vector<String16> &args) {
     ATRACE_CALL();
-    (void)args;
 
     // Try to lock, but continue in case of failure (to avoid blocking in
     // deadlocks)
diff --git a/services/camera/libcameraservice/device3/Camera3FakeStream.cpp b/services/camera/libcameraservice/device3/Camera3FakeStream.cpp
index 19afd69..8c0ac71 100644
--- a/services/camera/libcameraservice/device3/Camera3FakeStream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3FakeStream.cpp
@@ -67,8 +67,7 @@
     return INVALID_OPERATION;
 }
 
-void Camera3FakeStream::dump(int fd, const Vector<String16> &args) const {
-    (void) args;
+void Camera3FakeStream::dump(int fd, [[maybe_unused]] const Vector<String16> &args) const {
     String8 lines;
     lines.appendFormat("    Stream[%d]: Fake\n", mId);
     write(fd, lines.string(), lines.size());
@@ -82,9 +81,8 @@
     return OK;
 }
 
-status_t Camera3FakeStream::detachBuffer(sp<GraphicBuffer>* buffer, int* fenceFd) {
-    (void) buffer;
-    (void) fenceFd;
+status_t Camera3FakeStream::detachBuffer([[maybe_unused]] sp<GraphicBuffer>* buffer,
+                [[maybe_unused]] int* fenceFd) {
     // Do nothing
     return OK;
 }
diff --git a/services/camera/libcameraservice/device3/Camera3IOStreamBase.cpp b/services/camera/libcameraservice/device3/Camera3IOStreamBase.cpp
index f594f84..314e007 100644
--- a/services/camera/libcameraservice/device3/Camera3IOStreamBase.cpp
+++ b/services/camera/libcameraservice/device3/Camera3IOStreamBase.cpp
@@ -73,8 +73,7 @@
     return false;
 }
 
-void Camera3IOStreamBase::dump(int fd, const Vector<String16> &args) const {
-    (void) args;
+void Camera3IOStreamBase::dump(int fd, [[maybe_unused]] const Vector<String16> &args) const {
     String8 lines;
 
     uint64_t consumerUsage = 0;
diff --git a/services/camera/libcameraservice/device3/Camera3InputStream.cpp b/services/camera/libcameraservice/device3/Camera3InputStream.cpp
index 9a3f7ed..631bb43 100644
--- a/services/camera/libcameraservice/device3/Camera3InputStream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3InputStream.cpp
@@ -104,17 +104,14 @@
 
 status_t Camera3InputStream::returnBufferCheckedLocked(
             const camera_stream_buffer &buffer,
-            nsecs_t timestamp,
-            nsecs_t readoutTimestamp,
-            bool output,
+            [[maybe_unused]] nsecs_t timestamp,
+            [[maybe_unused]] nsecs_t readoutTimestamp,
+            [[maybe_unused]] bool output,
             int32_t /*transform*/,
             const std::vector<size_t>&,
             /*out*/
             sp<Fence> *releaseFenceOut) {
 
-    (void)timestamp;
-    (void)readoutTimestamp;
-    (void)output;
     ALOG_ASSERT(!output, "Expected output to be false");
 
     status_t res;
@@ -218,8 +215,7 @@
     return OK;
 }
 
-void Camera3InputStream::dump(int fd, const Vector<String16> &args) const {
-    (void) args;
+void Camera3InputStream::dump(int fd, [[maybe_unused]] const Vector<String16> &args) const {
     String8 lines;
     lines.appendFormat("    Stream[%d]: Input\n", mId);
     write(fd, lines.string(), lines.size());
diff --git a/services/camera/libcameraservice/device3/Camera3OutputStream.cpp b/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
index 396104c..3035aa5 100644
--- a/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3OutputStream.cpp
@@ -393,13 +393,12 @@
             const camera_stream_buffer &buffer,
             nsecs_t timestamp,
             nsecs_t readoutTimestamp,
-            bool output,
+            [[maybe_unused]] bool output,
             int32_t transform,
             const std::vector<size_t>& surface_ids,
             /*out*/
             sp<Fence> *releaseFenceOut) {
 
-    (void)output;
     ALOG_ASSERT(output, "Expected output to be true");
 
     status_t res;
@@ -522,8 +521,7 @@
     return res;
 }
 
-void Camera3OutputStream::dump(int fd, const Vector<String16> &args) const {
-    (void) args;
+void Camera3OutputStream::dump(int fd, [[maybe_unused]] const Vector<String16> &args) const {
     String8 lines;
     lines.appendFormat("    Stream[%d]: Output\n", mId);
     lines.appendFormat("      Consumer name: %s\n", mConsumerName.string());
diff --git a/services/camera/libcameraservice/device3/Camera3Stream.cpp b/services/camera/libcameraservice/device3/Camera3Stream.cpp
index 88be9ff..2c21e7e 100644
--- a/services/camera/libcameraservice/device3/Camera3Stream.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Stream.cpp
@@ -949,9 +949,8 @@
     }
 }
 
-void Camera3Stream::dump(int fd, const Vector<String16> &args) const
+void Camera3Stream::dump(int fd, [[maybe_unused]] const Vector<String16> &args) const
 {
-    (void)args;
     mBufferLimitLatency.dump(fd,
             "      Latency histogram for wait on max_buffers");
 }
diff --git a/services/camera/libcameraservice/tests/CameraProviderManagerTest.cpp b/services/camera/libcameraservice/tests/CameraProviderManagerTest.cpp
index 2f55def..1a6b2e0 100644
--- a/services/camera/libcameraservice/tests/CameraProviderManagerTest.cpp
+++ b/services/camera/libcameraservice/tests/CameraProviderManagerTest.cpp
@@ -185,9 +185,8 @@
     using getCameraDeviceInterface_V1_x_cb = std::function<void(Status status,
             const sp<device::V1_0::ICameraDevice>& device)>;
     virtual hardware::Return<void> getCameraDeviceInterface_V1_x(
-            const hardware::hidl_string& cameraDeviceName,
+            [[maybe_unused]] const hardware::hidl_string& cameraDeviceName,
             getCameraDeviceInterface_V1_x_cb _hidl_cb) override {
-        (void) cameraDeviceName;
         _hidl_cb(Status::OK, nullptr); //TODO: impl. of ver. 1.0 device interface
                                        //      otherwise enumeration will fail.
         return hardware::Void();
@@ -261,9 +260,8 @@
     virtual ~TestInteractionProxy() {}
 
     virtual bool registerForNotifications(
-            const std::string &serviceName,
+            [[maybe_unused]] const std::string &serviceName,
             const sp<hidl::manager::V1_0::IServiceNotification> &notification) override {
-        (void) serviceName;
         mManagerNotificationInterface = notification;
         return true;
     }
diff --git a/services/camera/libcameraservice/tests/DistortionMapperTest.cpp b/services/camera/libcameraservice/tests/DistortionMapperTest.cpp
index 8331136..b367571 100644
--- a/services/camera/libcameraservice/tests/DistortionMapperTest.cpp
+++ b/services/camera/libcameraservice/tests/DistortionMapperTest.cpp
@@ -355,8 +355,6 @@
 #include "DistortionMapperTest_OpenCvData.h"
 
 TEST(DistortionMapperTest, CompareToOpenCV) {
-    status_t res;
-
     float bigDistortion[] = {0.1, -0.003, 0.004, 0.02, 0.01};
 
     // Expect to match within sqrt(2) radius pixels
@@ -370,7 +368,7 @@
     using namespace openCvData;
 
     DistortionMapperInfo *mapperInfo = m.getMapperInfo();
-    res = m.mapRawToCorrected(rawCoords.data(), rawCoords.size() / 2, mapperInfo, /*clamp*/false,
+    m.mapRawToCorrected(rawCoords.data(), rawCoords.size() / 2, mapperInfo, /*clamp*/false,
             /*simple*/false);
 
     for (size_t i = 0; i < rawCoords.size(); i+=2) {
diff --git a/services/camera/libcameraservice/tests/ZoomRatioTest.cpp b/services/camera/libcameraservice/tests/ZoomRatioTest.cpp
index ff7aafd..b3a1d18 100644
--- a/services/camera/libcameraservice/tests/ZoomRatioTest.cpp
+++ b/services/camera/libcameraservice/tests/ZoomRatioTest.cpp
@@ -160,11 +160,9 @@
             false/*hasZoomRatioRange*/, zoomRatioRange,
             usePreCorrectArray));
 
-    size_t index = 0;
     int32_t width = testActiveArraySize[2];
     int32_t height = testActiveArraySize[3];
     if (usePreCorrectArray) {
-        index = 1;
         width = testPreCorrActiveArraySize[2];
         height = testPreCorrActiveArraySize[3];
     }