I am writing a gnu make file to build and run C++ unit tests. I have the makefile put its .o files in the same directory that holds the make file.
We have a different set of makefiles used to build our products for delivery. Those makefiles puts each .o file in the same directory that has the corresponding C++ source file.
My unit test makefile defines its .o target as "%.o: %.cpp". In that makefile, I define VPATH to have the location of the .cpp files. In addition, my unit test compilation command generates and uses .d files using the g++ MMD and MP options.
So here is the problem I am having.
I want my unit test makefile target to only evaluate the .o target by looking in my unit test makefile directory.
If the product delivery makefile already generated a .o out where the source file lives, I still want my unit test makefile to only consider its directory to determine if I need to rebuild the .o file.
However, that's not happening. If a product delivery makefile had already put a .o where the source code lives, the unit test makefile sees that .o, and it says that the .o does not need to be built.
Is there a way for me to force my unit test makefile to only consider the unit test make file directory when evaluating .o file targets?
