libblifparse: Updating libs/EXTERNAL/libblifparse/ (external git subtree from https://github.com/kmurray/libblifparse.git master)

Author: kmurray

libs/EXTERNAL/libblifparse/CMakeLists.txt

@@ -49,6 +49,19 @@ set_target_properties(libblifparse PROPERTIES PREFIX "") #Avoid extra 'lib' pref
 add_executable(blifparse_test src/main.cpp)
 target_link_libraries(blifparse_test libblifparse)
 
+#Suppress IPO link warnings
+get_target_property(USES_IPO blifparse_test INTERPROCEDURAL_OPTIMIZATION)
+if (USES_IPO)
+    set(IPO_LINK_WARN_FLAGS_TO_CHECK "-Wno-null-dereference")
+    foreach(flag ${IPO_LINK_WARN_FLAGS_TO_CHECK})
+        CHECK_CXX_COMPILER_FLAG(${flag} CXX_COMPILER_SUPPORTS_${flag})
+        if(CXX_COMPILER_SUPPORTS_${flag})
+            #Flag supported, so enable it
+            set_target_properties(blifparse_test PROPERTIES LINK_FLAGS ${flag})
+        endif()
+    endforeach()
+endif()
+
 if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
     #Add the tests if we are the root project
     enable_testing()