问题
My problem is as follows :
I have OpenSSL as static libraries (libcrypto.a and libssl.a).
Compiled on Windows with MSys2/MinGW64.
Besides that, I have a small self written library based on OpenSSL.
Now I want to "bundle" the Crypto lib from OpenSSL with My lib to a "big" static library for later statically compiling in other applications on Windows without deploying any library.
What would a CMakeLists.txt file looks like? And are the prerequisites (OpenSSL as static libs) correct?
Actually compiling this to a dynamic DLL works like a charm. But My static lib are only includes the symbols of My own library, not from OpenSSL too.
Actually I have no working CMake file, so I can't include an example. I'm just looking for a direction how to do it.
A short suggestion how to begin would be highly appreciated.
回答1:
If what you really want to do is combine multiple static libraries into one, for the convenience of external consumers, you'll probably need to run a custom command to do this (as it's not something that's frequently done).
Using the GNU toolchain, the commands to do so might look something like this (untested though):
${CMAKE_COMMAND} -E make_directory tempdir
cd tempdir
${CMAKE_AR} x $<yourlib:TARGET_FILE>
${CMAKE_AR} x ${OPENSSL_CRYPTO_LIBRARY}
${CMAKE_AR} x ${OPENSSL_SSL_LIBRARY}
${CMAKE_AR} cf ${CMAKE_BINARY_DIR}/bin/libyourmegalib.a *.o
cd ..
${CMAKE_COMMAND} -E remove_directory tempdir
Then you would use add_custom_command() to create a target to run this script - either put those lines as COMMAND arguments, or create a script template, substitute values at CMake generation time using configure_file(), then have the custom command run that script.
That said, if the external consumers are all using CMake themselves, I would skip this entirely, and just have the installation process for your library generate CMake package configuration files that declare the dependencies on the OpenSSL libraries.
回答2:
target_link_library() works both for add_executable() and add_library(), so you should be able to do:
add_library(yourlib STATIC ...)
target_link_libraries(yourlib lib1 lib2 ...)
(where yourlib is your library, and lib1, ... are the libraries you want to bundle.
来源：https://stackoverflow.com/questions/49945142/cmake-building-a-static-library-with-other-static-library