From 22ee5c0c4db9111780c6d34eb2a3c85e0f4046ff Mon Sep 17 00:00:00 2001
From: Rob Timpe <rob@xwing.com>
Date: Wed, 21 Oct 2020 15:51:46 -0700
Subject: [PATCH] Fix errors when building with cuda stubs

Fixes two errors when building with the options WITH_CUDA=ON and BUILD_CUDA_STUBS=ON on a machine without CUDA.

In the cudaarithm module, make sure cuda_runtime.h only gets included when CUDA is installed.

In the stitching module, don't assume that cuda is present just because cudaarithm and cudawarping are present (as is the case when building with the above options).
---
 modules/cudaarithm/src/lut.cpp     |  5 +++--
 modules/stitching/src/blenders.cpp | 16 ++++++++--------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/modules/cudaarithm/src/lut.cpp b/modules/cudaarithm/src/lut.cpp
index a4b4e02650..5ef2836017 100644
--- a/modules/cudaarithm/src/lut.cpp
+++ b/modules/cudaarithm/src/lut.cpp
@@ -4,8 +4,6 @@
 
 #include "precomp.hpp"
 
-#include "lut.hpp"
-
 using namespace cv;
 using namespace cv::cuda;
 
@@ -15,6 +13,9 @@ Ptr<LookUpTable> cv::cuda::createLookUpTable(InputArray) { throw_no_cuda(); retu
 
 #else /* !defined (HAVE_CUDA) || defined (CUDA_DISABLER) */
 
+// lut.hpp includes cuda_runtime.h and can only be included when we have CUDA
+#include "lut.hpp"
+
 Ptr<LookUpTable> cv::cuda::createLookUpTable(InputArray lut)
 {
     return makePtr<LookUpTableImpl>(lut);
diff --git a/modules/stitching/src/blenders.cpp b/modules/stitching/src/blenders.cpp
index aeddc142dc..05e7ca85e4 100644
--- a/modules/stitching/src/blenders.cpp
+++ b/modules/stitching/src/blenders.cpp
@@ -219,7 +219,7 @@ MultiBandBlender::MultiBandBlender(int try_gpu, int num_bands, int weight_type)
     num_bands_ = 0;
     setNumBands(num_bands);
 
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     can_use_gpu_ = try_gpu && cuda::getCudaEnabledDeviceCount();
     gpu_feed_idx_ = 0;
 #else
@@ -246,7 +246,7 @@ void MultiBandBlender::prepare(Rect dst_roi)
 
     Blender::prepare(dst_roi);
 
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     if (can_use_gpu_)
     {
         gpu_initialized_ = false;
@@ -332,7 +332,7 @@ void MultiBandBlender::feed(InputArray _img, InputArray mask, Point tl)
 
     UMat img;
 
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     // If using gpu save the top left coordinate when running first time after prepare
     if (can_use_gpu_)
     {
@@ -353,7 +353,7 @@ void MultiBandBlender::feed(InputArray _img, InputArray mask, Point tl)
     {
         img = _img.getUMat();
     }
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     else
     {
         gpu_img_ = _img.getGpuMat();
@@ -394,7 +394,7 @@ void MultiBandBlender::feed(InputArray _img, InputArray mask, Point tl)
     int bottom = br_new.y - tl.y - img.rows;
     int right = br_new.x - tl.x - img.cols;
 
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     if (can_use_gpu_)
     {
         if (!gpu_initialized_)
@@ -603,7 +603,7 @@ void MultiBandBlender::feed(InputArray _img, InputArray mask, Point tl)
 void MultiBandBlender::blend(InputOutputArray dst, InputOutputArray dst_mask)
 {
     Rect dst_rc(0, 0, dst_roi_final_.width, dst_roi_final_.height);
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     if (can_use_gpu_)
     {
         if (!gpu_initialized_)
@@ -850,7 +850,7 @@ void createLaplacePyr(InputArray img, int num_levels, std::vector<UMat> &pyr)
 
 void createLaplacePyrGpu(InputArray img, int num_levels, std::vector<UMat> &pyr)
 {
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     pyr.resize(num_levels + 1);
 
     std::vector<cuda::GpuMat> gpu_pyr(num_levels + 1);
@@ -891,7 +891,7 @@ void restoreImageFromLaplacePyr(std::vector<UMat> &pyr)
 
 void restoreImageFromLaplacePyrGpu(std::vector<UMat> &pyr)
 {
-#if defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
+#if defined(HAVE_CUDA) && defined(HAVE_OPENCV_CUDAARITHM) && defined(HAVE_OPENCV_CUDAWARPING)
     if (pyr.empty())
         return;