[CMake] undef a symbol

[Totte Karlsson]

Hi,
I have a folder in which I build a library. For doing so I have a
add_definitions(-DMySymbol) line

It seems that subfolders inherits this,which I don't want. How do I "undef" the 
MySymbol symbol in a subfolder CMakeList file?

-totte

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Totte Karlsson, Ph.D.
Dune Scientific, LLC
425-296 1980 (office)
425-780 9648 (cell)
www.dunescientific.com
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