Fixed the CMake add_cxx_compiler_flag function

cmake/AddCXXCompilerFlag.cmake

@@ -25,13 +25,12 @@ function(add_cxx_compiler_flag FLAG)
     string(TOLOWER ${VARIANT} VARIANT)
     set(VARIANT " ${VARIANT}")
   endif()
-  message("-- Check compiler${VARIANT} flag ${FLAG}")
-  string(TOUPPER ${FLAG} SANITIZED_FLAG)
-  string(REGEX REPLACE "[^A-Za-z_0-9]" "_" ${SANITIZED_FLAG} SANITIZED_FLAG)
+  string(TOUPPER "HAVE_${FLAG}" SANITIZED_FLAG)
+  string(REGEX REPLACE "[^A-Za-z_0-9]" "_" SANITIZED_FLAG ${SANITIZED_FLAG})
+  string(REGEX REPLACE "_+" "_" SANITIZED_FLAG ${SANITIZED_FLAG})
   check_cxx_compiler_flag(${FLAG} ${SANITIZED_FLAG})
   if(${SANITIZED_FLAG})
-    message("-- Check compiler${VARIANT} flag ${FLAG} -- works")
-    string(REGEX REPLACE "[^A-Za-z_0-9]" "_" "${VARIANT}" VARIANT)
+    string(REGEX REPLACE "[^A-Za-z_0-9]" "_" VARIANT "${VARIANT}")
     string(TOUPPER "${VARIANT}" VARIANT)
     set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS}${VARIANT} ${FLAG}" PARENT_SCOPE)
   endif()

cmake/CXXFeatureCheck.cmake

@@ -4,19 +4,18 @@
 # and adds the corresponding `HAVE_[FILENAME]` flag to the CMake
 # environment
 #
-#  add_cxx_compiler_FLAG(<FLAG> [<VARIANT>])
+#  cxx_feature_check(<FLAG> [<VARIANT>])
 #
 # - Example
 #
-# include(AddCXXCompilerFlag)
-# add_cxx_compiler_FLAG(-Wall)
-# add_cxx_compiler_FLAG(-no-strict-aliasing RELEASE)
+# include(CXXFeatureCheck)
+# cxx_feature_check(STD_REGEX)
 # Requires CMake 2.6+
 
-if(__cxx_feature_check_FLAG)
+if(__cxx_feature_check)
   return()
 endif()
-set(__cxx_feature_check_FLAG INCLUDED)
+set(__cxx_feature_check INCLUDED)
 
 function(cxx_feature_check FILE)
   string(TOLOWER ${FILE} FILE)