How to limit the scope of compiler flags only to a (my) local library?

Code
1

1

I am trying the example below :

add_library(
        mylib
        src/my_code.cpp)

target_include_directories(mylib
        PUBLIC include ${catkin_INCLUDE_DIRS} ${thirdPartyLib_INCLUDE_DIRS})

add_dependencies(
        mylib
        ${mylib_EXPORTED_TARGETS}
        ${catkin_EXPORTED_TARGETS})


target_link_libraries(mylib
        PUBLIC
        ${thirdPartyLib_LIBRARY} ${ ${catkin_LIBRARIES})

target_compile_options(mylib PRIVATE -Werror -Wall -Wextra)

The issue is that the compile options also propagate to thirdPartyLib , yet I need them only for mylib .

2

Try adding the thirdPartyLib_INCLUDE_DIRS as SYSTEM. That should silence the warnings/errors those headers may cause.

3

Isn’t add_dependencies causing that behavior? Did you try to create a separate target for the third party lib (so it compiles with default flags) and then link it with your main lib using target_link_libraries?

4

Did not solve the issue.

5

Your example is incomplete. How is created thirdPartyLib? Are you sure same compile flags are not also defined for this target?

6

It is found with
find_package(thirdPartyLib)

7

Is it a module delivered as part of CMake? If yes, please give the information.
If no, how is consumed this library? through a imported target or not?
Did you check that these flags are not defined elsewhere (globally or at directory level using command add_compile_options or variable CMAKE_<LANG>_FLAGS)?

Currently, without a complete environment description, it is impossible to identify where come from your problem.

8

thirdPartyLib is a custom lib not part of CMake. The compilation does not break if I remove my compile flags. Then the issue is at my CMake file.