How to limit C_FLAGS to certain libraries

Code
#1

We are trying to reduce warnings in our code base by promoting some warnings to errors.
We build the list of warnings during configure time and add them to CMAKE_C_FLAGS.
This was fine until we started implementing the list of -Werror=xxx.
First was CMake FortranCInterface failed to compile with:
-Werror=missing-declarations
-Werror=missing-prototypes
After fixing that, then the errors in examples and tests started failing - libraries and programs outside the intended code base for the stricter warnings.

I am looking for advice and how to selectively choose which library/sub-folder/target get which list of flags. Is there an easy way to set the CMAKE_C_FLAGS only on a specific library/sub-folder/target?

Allen

#2

Use target properties (Mainly target COMPILE_OPTIONS).

Properties can also be set at directory level (see directory COMPILE_OPTIONS).