Updated warning options for GCC; fixed new warnings.

cmake/OpenCVCompilerOptions.cmake

@@ -58,6 +58,7 @@ endif()
 
 if(CMAKE_COMPILER_IS_GNUCXX)
   # High level of warnings.
+  add_extra_compiler_option(-W)
   add_extra_compiler_option(-Wall)
   add_extra_compiler_option(-Werror=return-type)
   add_extra_compiler_option(-Werror=non-virtual-dtor)
@@ -72,6 +73,7 @@ if(CMAKE_COMPILER_IS_GNUCXX)
   add_extra_compiler_option(-Winit-self)
   add_extra_compiler_option(-Wpointer-arith)
   add_extra_compiler_option(-Wshadow)
+  add_extra_compiler_option(-Wsign-promo)
 
   if(ENABLE_NOISY_WARNINGS)
     add_extra_compiler_option(-Wcast-align)
@@ -81,6 +83,7 @@ if(CMAKE_COMPILER_IS_GNUCXX)
     add_extra_compiler_option(-Wno-delete-non-virtual-dtor)
     add_extra_compiler_option(-Wno-unnamed-type-template-args)
   endif()
+  add_extra_compiler_option(-fdiagnostics-show-option)
 
   # The -Wno-long-long is required in 64bit systems when including sytem headers.
   if(X86_64)

cmake/OpenCVConfig.cmake

@@ -30,10 +30,7 @@
 #    Advanced variables:
 #      - OpenCV_SHARED
 #      - OpenCV_CONFIG_PATH
-#      - OpenCV_INSTALL_PATH  (not set on Windows)
 #      - OpenCV_LIB_COMPONENTS
-#      - OpenCV_USE_MANGLED_PATHS
-#      - OpenCV_HAVE_ANDROID_CAMERA
 #
 # ===================================================================================
 #
@@ -41,6 +38,13 @@
 #      - OpenCV_STATIC
 #      - OpenCV_CUDA
 
+if(CMAKE_VERSION VERSION_GREATER 2.6)
+  get_property(OpenCV_LANGUAGES GLOBAL PROPERTY ENABLED_LANGUAGES)
+  if(NOT ";${OpenCV_LANGUAGES};" MATCHES ";CXX;")
+    enable_language(CXX)
+  endif()
+endif()
+
 if(NOT DEFINED OpenCV_STATIC)
   # look for global setting
   if(NOT DEFINED BUILD_SHARED_LIBS OR BUILD_SHARED_LIBS)

cmake/OpenCVUtils.cmake

@@ -34,6 +34,7 @@ endmacro()
 
 set(OCV_COMPILER_FAIL_REGEX
     "command line option .* is valid for .* but not for C\\+\\+" # GNU
+    "command line option .* is valid for .* but not for C" # GNU
     "unrecognized .*option"                     # GNU
     "unknown .*option"                          # Clang
     "ignoring unknown option"                   # MSVC