cmake: fix variable expand in CMake conditions

CMakeLists.txt

@@ -96,6 +96,10 @@ if(POLICY CMP0051)
   cmake_policy(SET CMP0051 NEW)
 endif()
 
+if(POLICY CMP0054)  # CMake 3.1: Only interpret if() arguments as variables or keywords when unquoted.
+  cmake_policy(SET CMP0054 NEW)
+endif()
+
 if(POLICY CMP0056)
   cmake_policy(SET CMP0056 NEW)
 endif()

cmake/OpenCVCompilerOptimizations.cmake

@@ -50,13 +50,13 @@ endforeach()
 
 # process legacy flags
 macro(ocv_optimization_process_obsolete_option legacy_flag OPT legacy_warn)
-  if(DEFINED ${legacy_flag})
-    if(${legacy_warn})
+  if(DEFINED "${legacy_flag}")
+    if("${legacy_warn}")
       message(STATUS "WARNING: Option ${legacy_flag}='${${legacy_flag}}' is deprecated and should not be used anymore")
       message(STATUS "         Behaviour of this option is not backward compatible")
       message(STATUS "         Refer to 'CPU_BASELINE'/'CPU_DISPATCH' CMake options documentation")
     endif()
-    if(${legacy_flag})
+    if("${legacy_flag}")
       if(NOT ";${CPU_BASELINE_REQUIRE};" MATCHES ";${OPT};")
         set(CPU_BASELINE_REQUIRE "${CPU_BASELINE_REQUIRE};${OPT}" CACHE STRING "${HELP_CPU_BASELINE_REQUIRE}" FORCE)
       endif()

cmake/OpenCVDetectCUDA.cmake

@@ -114,9 +114,9 @@ if(CUDA_FOUND)
       endif()
       set(__cuda_arch_ptx "")
     else()
-      if(${CUDA_VERSION} VERSION_LESS "9.0")
+      if(CUDA_VERSION VERSION_LESS "9.0")
         set(__cuda_arch_bin "2.0 3.0 3.5 3.7 5.0 5.2 6.0 6.1")
-      elseif(${CUDA_VERSION} VERSION_LESS "10.0")
+      elseif(CUDA_VERSION VERSION_LESS "10.0")
         set(__cuda_arch_bin "3.0 3.5 3.7 5.0 5.2 6.0 6.1 7.0")
       else()
         set(__cuda_arch_bin "3.0 3.5 3.7 5.0 5.2 6.0 6.1 7.0 7.5")

cmake/OpenCVDetectVTK.cmake

@@ -20,27 +20,27 @@ if(NOT VTK_FOUND)
 endif()
 
 # Don't support earlier VTKs
-if(${VTK_VERSION} VERSION_LESS "5.8.0")
+if(VTK_VERSION VERSION_LESS "5.8.0")
   message(STATUS "VTK support is disabled. VTK ver. 5.8.0 is minimum required, but found VTK ver. ${VTK_VERSION}")
   return()
 endif()
 
 # Different Qt versions can't be linked together
-if(HAVE_QT5 AND ${VTK_VERSION} VERSION_LESS "6.0.0")
+if(HAVE_QT5 AND VTK_VERSION VERSION_LESS "6.0.0")
   if(VTK_USE_QT)
     message(STATUS "VTK support is disabled. Incompatible combination: OpenCV + Qt5 and VTK ver.${VTK_VERSION} + Qt4")
   endif()
 endif()
 
 # Different Qt versions can't be linked together. VTK 6.0.0 doesn't provide a way to get Qt version it was linked with
-if(HAVE_QT5 AND ${VTK_VERSION} VERSION_EQUAL "6.0.0" AND NOT DEFINED FORCE_VTK)
+if(HAVE_QT5 AND VTK_VERSION VERSION_EQUAL "6.0.0" AND NOT DEFINED FORCE_VTK)
   message(STATUS "VTK support is disabled. Possible incompatible combination: OpenCV+Qt5, and VTK ver.${VTK_VERSION} with Qt4")
   message(STATUS "If it is known that VTK was compiled without Qt4, please define '-DFORCE_VTK=TRUE' flag in CMake")
   return()
 endif()
 
 # Different Qt versions can't be linked together
-if(HAVE_QT AND ${VTK_VERSION} VERSION_GREATER "6.0.0" AND NOT ${VTK_QT_VERSION} STREQUAL "")
+if(HAVE_QT AND VTK_VERSION VERSION_GREATER "6.0.0" AND NOT ${VTK_QT_VERSION} STREQUAL "")
   if(HAVE_QT5 AND ${VTK_QT_VERSION} EQUAL "4")
     message(STATUS "VTK support is disabled. Incompatible combination: OpenCV + Qt5 and VTK ver.${VTK_VERSION} + Qt4")
     return()

cmake/OpenCVFindIPP.cmake

@@ -105,7 +105,7 @@ macro(ipp_detect_version)
   message(STATUS "found Intel IPP${__msg}: ${_MAJOR}.${_MINOR}.${_BUILD} [${IPP_VERSION_STR}]")
   message(STATUS "at: ${IPP_ROOT_DIR}")
 
-  if(${IPP_VERSION_STR} VERSION_LESS "7.0")
+  if(IPP_VERSION_STR VERSION_LESS "7.0")
     _ipp_not_supported("Intel IPP ${IPP_VERSION_STR} is not supported")
   endif()
 
@@ -166,7 +166,7 @@ macro(ipp_detect_version)
   endmacro()
 
   set(IPP_PREFIX "ipp")
-  if(${IPP_VERSION_STR} VERSION_LESS "8.0")
+  if(IPP_VERSION_STR VERSION_LESS "8.0")
     if (BUILD_WITH_DYNAMIC_IPP AND NOT HAVE_IPP_ICV)
       set(IPP_SUFFIX "")      # dynamic not threaded libs suffix Intel IPP 7.x
     else ()

cmake/OpenCVFindMKL.cmake

@@ -94,7 +94,7 @@ else()
     set(MKL_ARCH_SUFFIX "c")
 endif()
 
-if(${MKL_VERSION_STR} VERSION_GREATER "11.3.0" OR ${MKL_VERSION_STR} VERSION_EQUAL "11.3.0")
+if(MKL_VERSION_STR VERSION_GREATER "11.3.0" OR MKL_VERSION_STR VERSION_EQUAL "11.3.0")
     set(mkl_lib_find_paths
         ${MKL_ROOT_DIR}/lib
         ${MKL_ROOT_DIR}/lib/${MKL_ARCH} ${MKL_ROOT_DIR}/../tbb/lib/${MKL_ARCH})

cmake/OpenCVModule.cmake

@@ -615,7 +615,7 @@ function(__ocv_resolve_dependencies)
               list(APPEND LINK_DEPS opencv_world)
             endif()
           endif()
-          if(${m} STREQUAL opencv_world)
+          if("${m}" STREQUAL opencv_world)
             list(APPEND OPENCV_MODULE_opencv_world_DEPS_EXT ${OPENCV_MODULE_${m2}_DEPS_EXT})
           endif()
         endif()
@@ -842,7 +842,7 @@ macro(ocv_create_module)
   if(NOT " ${ARGN}" STREQUAL " ")
     set(OPENCV_MODULE_${the_module}_LINK_DEPS "${OPENCV_MODULE_${the_module}_LINK_DEPS};${ARGN}" CACHE INTERNAL "")
   endif()
-  if(${BUILD_opencv_world} AND OPENCV_MODULE_${the_module}_IS_PART_OF_WORLD)
+  if(BUILD_opencv_world AND OPENCV_MODULE_${the_module}_IS_PART_OF_WORLD)
     # nothing
     set(the_module_target opencv_world)
   else()

cmake/OpenCVPackaging.cmake

@@ -89,7 +89,7 @@ set(CPACK_COMPONENT_TESTS_DEPENDS libs)
 
 if(HAVE_CUDA)
   string(REPLACE "." "-" cuda_version_suffix ${CUDA_VERSION})
-  if(${CUDA_VERSION} VERSION_LESS "6.5")
+  if(CUDA_VERSION VERSION_LESS "6.5")
     set(CPACK_DEB_libs_PACKAGE_DEPENDS "cuda-core-libs-${cuda_version_suffix}, cuda-extra-libs-${cuda_version_suffix}")
     set(CPACK_DEB_dev_PACKAGE_DEPENDS "cuda-headers-${cuda_version_suffix}")
   else()

cmake/templates/OpenCVConfig-CUDA.cmake.in

@@ -16,7 +16,7 @@ endif()
 
 set(OpenCV_CUDA_LIBS_ABSPATH ${CUDA_LIBRARIES})
 
-if(${CUDA_VERSION} VERSION_LESS "5.5")
+if(CUDA_VERSION VERSION_LESS "5.5")
   list(APPEND OpenCV_CUDA_LIBS_ABSPATH ${CUDA_npp_LIBRARY})
 else()
   find_cuda_helper_libs(nppc)