Detect version of clang compiler

CMakeLists.txt

@@ -523,10 +523,21 @@ if(NOT CMAKE_GENERATOR MATCHES "Xcode|Visual Studio")
 endif()
 
 # ========================== C/C++ options ==========================
+if(CMAKE_CXX_COMPILER_VERSION)
+  set(OPENCV_COMPILER_STR "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} (ver ${CMAKE_CXX_COMPILER_VERSION})")
+elseif(CMAKE_COMPILER_IS_CLANGCXX)
+  set(OPENCV_COMPILER_STR "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} (ver ${CMAKE_CLANG_REGEX_VERSION})")
+elseif(CMAKE_COMPILER_IS_GNUCXX)
+  set(OPENCV_COMPILER_STR "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} (ver ${CMAKE_GCC_REGEX_VERSION})")
+else()
+  set(OPENCV_COMPILER_STR "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1}")
+endif()
+string(STRIP "${OPENCV_COMPILER_STR}" OPENCV_COMPILER_STR)
+
 status("")
 status("  C/C++:")
 status("    Built as dynamic libs?:" BUILD_SHARED_LIBS THEN YES ELSE NO)
-status("    C++ Compiler:"           CMAKE_COMPILER_IS_GNUCXX THEN "${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} (ver ${CMAKE_GCC_REGEX_VERSION})" ELSE "${CMAKE_CXX_COMPILER}" )
+status("    C++ Compiler:"           ${OPENCV_COMPILER_STR})
 status("    C++ flags (Release):"    ${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_RELEASE})
 status("    C++ flags (Debug):"      ${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_DEBUG})
 status("    C Compiler:"             ${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ARG1})

cmake/OpenCVDetectCXXCompiler.cmake

@@ -8,10 +8,12 @@ endif()
 if(NOT APPLE)
   if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
     set(CMAKE_COMPILER_IS_GNUCXX 1)
+    set(CMAKE_COMPILER_IS_CLANGCXX 1)
     set(ENABLE_PRECOMPILED_HEADERS OFF CACHE BOOL "" FORCE)
   endif()
   if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
     set(CMAKE_COMPILER_IS_GNUCC 1)
+    set(CMAKE_COMPILER_IS_CLANGCC 1)
     set(ENABLE_PRECOMPILED_HEADERS OFF CACHE BOOL "" FORCE)
   endif()
 endif()
@@ -44,16 +46,24 @@ if(MSVC AND CMAKE_C_COMPILER MATCHES "icc")
     set(CV_ICC   __INTEL_COMPILER_FOR_WINDOWS)
 endif()
 
-if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang" OR (UNIX AND CV_ICC))
-  set(CV_COMPILER_IS_GNU TRUE)
-else()
-  set(CV_COMPILER_IS_GNU FALSE)
-endif()
-
 # ----------------------------------------------------------------------------
 # Detect GNU version:
 # ----------------------------------------------------------------------------
-if(CMAKE_COMPILER_IS_GNUCXX)
+if(CMAKE_COMPILER_IS_CLANGCXX)
+  set(CMAKE_GCC_REGEX_VERSION "4.2.1")
+  set(CMAKE_OPENCV_GCC_VERSION_MAJOR 4)
+  set(CMAKE_OPENCV_GCC_VERSION_MINOR 2)
+  set(CMAKE_OPENCV_GCC_VERSION 42)
+  set(CMAKE_OPENCV_GCC_VERSION_NUM 402)
+
+  execute_process(COMMAND ${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} -v
+                  ERROR_VARIABLE CMAKE_OPENCV_CLANG_VERSION_FULL
+                  ERROR_STRIP_TRAILING_WHITESPACE)
+
+  string(REGEX MATCH "version.*$" CMAKE_OPENCV_CLANG_VERSION_FULL "${CMAKE_OPENCV_CLANG_VERSION_FULL}")
+  string(REGEX MATCH "[0-9]+\\.[0-9]+" CMAKE_CLANG_REGEX_VERSION "${CMAKE_OPENCV_CLANG_VERSION_FULL}")
+
+elseif(CMAKE_COMPILER_IS_GNUCXX)
     execute_process(COMMAND ${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1} -dumpversion
                   OUTPUT_VARIABLE CMAKE_OPENCV_GCC_VERSION_FULL
                   OUTPUT_STRIP_TRAILING_WHITESPACE)

cmake/OpenCVUtils.cmake

@@ -141,7 +141,7 @@ macro(ocv_warnings_disable)
           set(${var} "${${var}} ${warning}")
         endforeach()
       endforeach()
-    elseif(CV_COMPILER_IS_GNU AND _gxx_warnings AND _flag_vars)
+    elseif((CMAKE_COMPILER_IS_GNUCXX OR (UNIX AND CV_ICC)) AND _gxx_warnings AND _flag_vars)
       foreach(var ${_flag_vars})
         foreach(warning ${_gxx_warnings})
           if(NOT warning MATCHES "^-Wno-")