cmake: use SYSTEM include directories

3rdparty/ippicv/CMakeLists.txt

@@ -4,7 +4,7 @@
 # ----------------------------------------------------------------------------
 project(${IPP_IW_LIBRARY})
 
-ocv_include_directories(${IPP_INCLUDE_DIRS} ${IPP_IW_PATH}/include)
+ocv_include_directories(SYSTEM ${IPP_INCLUDE_DIRS} ${IPP_IW_PATH}/include)
 add_definitions(-DIW_BUILD)
 if(HAVE_IPP_ICV)
   add_definitions(-DICV_BASE)

cmake/OpenCVFindLibsPerf.cmake

@@ -13,10 +13,10 @@ if(WITH_IPP)
   if(HAVE_IPP)
     include("${OpenCV_SOURCE_DIR}/cmake/OpenCVFindIPPIW.cmake")
     if(HAVE_IPP_IW)
-      ocv_include_directories(${IPP_IW_INCLUDES})
+      ocv_include_directories(SYSTEM ${IPP_IW_INCLUDES})
       list(APPEND OPENCV_LINKER_LIBS ${IPP_IW_LIBRARIES})
     endif()
-    ocv_include_directories(${IPP_INCLUDE_DIRS})
+    ocv_include_directories(SYSTEM ${IPP_INCLUDE_DIRS})
     list(APPEND OPENCV_LINKER_LIBS ${IPP_LIBRARIES})
 
     # Details: #10229

cmake/OpenCVFindProtobuf.cmake

@@ -51,7 +51,7 @@ else()
       add_library(libprotobuf UNKNOWN IMPORTED)
       set_target_properties(libprotobuf PROPERTIES
         IMPORTED_LOCATION "${Protobuf_LIBRARY}"
-        INTERFACE_INCLUDE_DIRECTORIES "${Protobuf_INCLUDE_DIR}"
+        INTERFACE_INCLUDE_SYSTEM_DIRECTORIES "${Protobuf_INCLUDE_DIR}"
       )
       get_protobuf_version(Protobuf_VERSION "${Protobuf_INCLUDE_DIR}")
     endif()