From 5e543c506f41ff85c1bd540450b5a25e154b7c1f Mon Sep 17 00:00:00 2001
From: MediaPipe Team <mediapipe-team@google.com>
Date: Mon, 17 Oct 2022 12:13:09 -0700
Subject: [PATCH] Fix unused variable warnings

Remove some unused variables and add unused attribute to other variables

PiperOrigin-RevId: 481706551
---
 mediapipe/objc/MPPCameraInputSource.m |  3 +--
 mediapipe/objc/MPPGraph.mm            |  6 +++---
 mediapipe/objc/MPPGraphTestBase.mm    | 16 +++++-----------
 mediapipe/objc/MPPGraphTests.mm       |  4 +---
 4 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/mediapipe/objc/MPPCameraInputSource.m b/mediapipe/objc/MPPCameraInputSource.m
index b9718680c..73b3549c4 100644
--- a/mediapipe/objc/MPPCameraInputSource.m
+++ b/mediapipe/objc/MPPCameraInputSource.m
@@ -244,7 +244,7 @@
       if ([_session canAddOutput:_depthDataOutput]) {
         [_session addOutput:_depthDataOutput];
 
-        AVCaptureConnection* connection =
+        AVCaptureConnection* __unused connection =
             [_depthDataOutput connectionWithMediaType:AVMediaTypeDepthData];
 
         // Set this when we have a handler.
@@ -327,7 +327,6 @@
   if (depthData.depthDataType != kCVPixelFormatType_DepthFloat32) {
     depthData = [depthData depthDataByConvertingToDepthDataType:kCVPixelFormatType_DepthFloat32];
   }
-  CVPixelBufferRef depthBuffer = depthData.depthDataMap;
   [self.delegate processDepthData:depthData timestamp:timestamp fromSource:self];
 }
 
diff --git a/mediapipe/objc/MPPGraph.mm b/mediapipe/objc/MPPGraph.mm
index 67d71720e..080cca20f 100644
--- a/mediapipe/objc/MPPGraph.mm
+++ b/mediapipe/objc/MPPGraph.mm
@@ -134,12 +134,12 @@ void CallFrameDelegate(void* wrapperVoid, const std::string& streamName,
         if (format == mediapipe::ImageFormat::SRGBA) {
           // Swap R and B channels.
           const uint8_t permuteMap[4] = {2, 1, 0, 3};
-          vImage_Error vError = vImagePermuteChannels_ARGB8888(
-              &vSource, &vDestination, permuteMap, kvImageNoFlags);
+          vImage_Error __unused vError =
+              vImagePermuteChannels_ARGB8888(&vSource, &vDestination, permuteMap, kvImageNoFlags);
           _GTMDevAssert(vError == kvImageNoError, @"vImagePermuteChannels failed: %zd", vError);
         } else {
           // Convert grayscale back to BGRA
-          vImage_Error vError = vImageGrayToBGRA(&vSource, &vDestination);
+          vImage_Error __unused vError = vImageGrayToBGRA(&vSource, &vDestination);
           _GTMDevAssert(vError == kvImageNoError, @"vImageGrayToBGRA failed: %zd", vError);
         }
 
diff --git a/mediapipe/objc/MPPGraphTestBase.mm b/mediapipe/objc/MPPGraphTestBase.mm
index ddd15f736..eb4ea0535 100644
--- a/mediapipe/objc/MPPGraphTestBase.mm
+++ b/mediapipe/objc/MPPGraphTestBase.mm
@@ -32,10 +32,11 @@ static UIImage* UIImageWithPixelBuffer(CVPixelBufferRef pixelBuffer) {
 static void EnsureOutputDirFor(NSString *outputFile) {
   NSFileManager *fileManager = [NSFileManager defaultManager];
   NSError *error = nil;
-  BOOL result = [fileManager createDirectoryAtPath:[outputFile stringByDeletingLastPathComponent]
-                       withIntermediateDirectories:YES
-                                        attributes:nil
-                                             error:&error];
+  BOOL __unused result =
+      [fileManager createDirectoryAtPath:[outputFile stringByDeletingLastPathComponent]
+             withIntermediateDirectories:YES
+                              attributes:nil
+                                   error:&error];
   // TODO: Log the error for clarity. The file-write will fail later
   // but it would be nice to see this error. However, 'error' is still testing
   // false and result is true even on an unwritable path-- not sure what's up.
@@ -89,17 +90,10 @@ static void EnsureOutputDirFor(NSString *outputFile) {
   __block CVPixelBufferRef output;
   graph.delegate = self;
 
-  // The XCTAssert macros contain references to self, which causes a retain cycle,
-  // since the block retains self and self retains the block. The cycle is broken
-  // at the end of this method, with _pixelBufferOutputBlock = nil, but Clang does
-  // not realize that and outputs a warning. WEAKIFY and STRONGIFY, though not
-  // strictly necessary, are used here to avoid the warning.
-  WEAKIFY(self);
   if (!_pixelBufferOutputBlock) {
     XCTestExpectation* outputReceived = [self expectationWithDescription:@"output received"];
     _pixelBufferOutputBlock = ^(MPPGraph* outputGraph, CVPixelBufferRef outputBuffer,
                                 const std::string& outputStreamName) {
-      STRONGIFY(self);
       XCTAssertEqualObjects(outputGraph, graph);
       XCTAssertEqual(outputStreamName, outputStream);
       CFRetain(outputBuffer);
diff --git a/mediapipe/objc/MPPGraphTests.mm b/mediapipe/objc/MPPGraphTests.mm
index c3cf48047..a68d4528d 100644
--- a/mediapipe/objc/MPPGraphTests.mm
+++ b/mediapipe/objc/MPPGraphTests.mm
@@ -287,9 +287,7 @@ REGISTER_CALCULATOR(ErrorCalculator);
   CFHolder<CVPixelBufferRef> inputBuffer;
   absl::Status status = CreateCVPixelBufferFromCGImage(_sourceImage.CGImage, &inputBuffer);
   XCTAssert(status.ok());
-  CVPixelBufferRef outputBuffer = [self runGraph:_graph
-                                 withPixelBuffer:*inputBuffer
-                                      packetType:MPPPacketTypePixelBuffer];
+  [self runGraph:_graph withPixelBuffer:*inputBuffer packetType:MPPPacketTypePixelBuffer];
   __weak MPPGraph* weakGraph = _graph;
   _graph = nil;
   XCTAssertNil(weakGraph);