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/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");
 }