From 971c4ca10be63bb2d3fa2201959b0ca60debe3d1 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@intel.com>
Date: Tue, 23 Oct 2018 14:45:51 +0300
Subject: [PATCH] cmake: don't undefine passed options

---
 cmake/OpenCVUtils.cmake | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/cmake/OpenCVUtils.cmake b/cmake/OpenCVUtils.cmake
index 3ae6162ba6..1751a2b44d 100644
--- a/cmake/OpenCVUtils.cmake
+++ b/cmake/OpenCVUtils.cmake
@@ -603,10 +603,12 @@ macro(OCV_OPTION variable description value)
       option(${variable} "${description}" ${__value})
     endif()
   else()
-    if(DEFINED ${variable})
-      # TODO: message(WARNING "Option will be ignored: ${variable} (=${${variable}})")
+    if(DEFINED ${variable} AND NOT OPENCV_HIDE_WARNING_UNSUPPORTED_OPTION)
+      message(WARNING "Unexpected option: ${variable} (=${${variable}})\nCondition: IF (${__condition})")
+    endif()
+    if(OPENCV_UNSET_UNSUPPORTED_OPTION)
+      unset(${variable} CACHE)
     endif()
-    unset(${variable} CACHE)
   endif()
   unset(__condition)
   unset(__value)