Convert a Static Library to a Shared Library?
CLinuxShared LibrariesStatic LibrariesC Problem Overview
I have a third-party library which consists mainly of a large number of static (.a) library files. I can compile this into a single .a library file, but I really need it to be a single .so shared library file.
Is there any way to convert a static .a file into a shared .so file? Or more generally is there a good way to combine a huge number of static .a files with a few .o object files into a single .so file?
C Solutions
Solution 1 - C
Does this (with appropriate -L's of course)
gcc -shared -o megalib.so foo.o bar.o -la_static_lib -lb_static_lib
Not do it?
Solution 2 - C
You can't do this if objects within static library was compiled without -fPIC or like.
Solution 3 - C
g++ -shared -o megalib.so foo.o bar.o -Wl,--whole-archive -la_static_lib -lb_static_lib -Wl,--no-whole-archive -lc_static_lib -lother_shared_object
I'm not sure about gcc, but for g++ I had to add the --whole-archive linker option to include the objects from the static libraries in the shared object. The --no-whole-archive option is necessary if you want to link to libc_static_lib.a and libother_shared_object.so, but not include them as a whole in megalib.so.
Solution 4 - C
ar -x can be also useful if you want to focus on specific objects from your .as and you don't want to add anything on your own.
Examples:
ar -x lib***.a
gcc -shared *.o -o lib***.so
Solution 5 - C
ar -x lib***.a
gcc -shared *.o -o lib***.so