CODEWITHSUNDEEP
c++cmakeshared-libraries
tjwrona
tjwrona

Reputation: 9025

CMake add_library containing other libraries

I'm designing a collection of libraries that can be linked in my other C++ projects. In order to make the collection easy to use I want to either be able to link to individual libraries, or link to one master library that contains all of the others. How can I specify this in a CMakeLists.txt file?

For example:

add_library(library1 SHARED
    file1.cpp
    file2.cpp
)

add_library(library2 SHARED
    file3.cpp
    file4.cpp
)

# Define a master library that contains both of the others
add_library(master_library SHARED
    library1
    library2
)

Is there a proper way to get this functionality with CMake?

EDIT:

This question is not a duplicate of: CMake: Is it possible to build an executable from only static libraries and no source?

This has to do with shared libraries only and has nothing to do with static libraries or executables.

Upvotes: 7

Views: 10419

Answers (3)

Caleb Huitt - cjhuitt
Caleb Huitt - cjhuitt

Reputation: 14951

If all you want is a convenient target for use by others and don't care about whether you have one or multiple libraries, cmake can do that with an interface library:

add_library(library1 SHARED
    file1.cpp
    file2.cpp
)

add_library(library2 SHARED
    file3.cpp
    file4.cpp
)

add_library(master_library INTERFACE)

# Link the master library with the other libraries
target_link_libraries(master_library INTERFACE
    library1
    library2
)

Then in another location if you have

target_link_libraries(my_executable PRIVATE
    master_library
)

my_executable will link against library1 and library2

Upvotes: 5

tjwrona
tjwrona

Reputation: 9025

This solution seemed to work.

add_library(library1 SHARED
    file1.cpp
    file2.cpp
)

add_library(library2 SHARED
    file3.cpp
    file4.cpp
)

# dummy file is required to avoid a cmake error, but this
# "dummy" file serves no other purpose and is empty.
add_library(master_library SHARED
    dummy.cpp
)

# Link the master library with the other libraries
target_link_libraries(master_library
    library1
    library2
)

After doing this, I was able to compile and link code using ONLY the master library.

Upvotes: 12

John Zwinck
John Zwinck

Reputation: 249592

Just make a function in your project:

function(link_all_libs TARGET)
    target_link_libraries(TARGET library1 library2)
endfunction(link_all_libs)

Now you can simply:

link_all_libs(myapp)

Upvotes: -1

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