Chat Gpt Chat Duplicates

So lets say i have another library lib-demo.a and it also dependency on libcrypto.a there will be duplicate libraries brought into my application if I use lib-demo.a and libgit2.a (meaning libcrypto.a will be duplicated)

Answer:

Yes, if you link against both lib-demo.a and libgit2.a, and both of them have a dependency on libcrypto.a, then there will be duplicate copies of libcrypto.a in your application. This can increase the size of your application and potentially cause problems at runtime.

To avoid this issue, you can create a single static library that includes both lib-demo.a and libgit2.a, and then link against this combined library. You can do this by using the ar command to combine the object files from both libraries into a single library file.

For example, to combine lib-demo.a and libgit2.a into a single library file called libcombined.a, you can use the following command:

ar -x lib-demo.a
ar -x libgit2.a
ar -rcs libcombined.a *.o

This will extract the object files from both libraries, combine them into a single library file, and remove the intermediate object files. You can then link against libcombined.a instead of lib-demo.a and libgit2.a, and there will be no duplicate copies of libcrypto.a in your application. #chatgpt

Myself:

Checked the build artifacts of different type of builds and it does look like the libgit2.a file is considarably larger:

admin  9041206 Feb 24 20:27 libgit2.a
admin      128 Feb 24 20:31 ..
admin  4941256 Feb 24 20:41 libgit2.so
admin      128 Feb 24 20:44 .

admin  7985868 Feb 24 19:58 libcrypto.a
admin  1154404 Feb 24 19:58 libssl.a

Hmm this isn't aligning as I thought it would if libgit2.a were to embed both libcrypto.a and libssl.a I would expect it to be heavier

#chatgpt: Even if libgit2.a is statically linked against libcrypto.a and libssl.a, it's possible that not all of the functions and symbols in those libraries are actually being used by libgit2.a. If libgit2.a only uses a subset of the functionality provided by libcrypto.a and libssl.a, then it would not need to include the entire contents of those libraries.

#chatgpt: When a library is statically linked against another library, the linker will include all of the object code from the linked library, even if not all of the functions or symbols in that library are actually used by the application. However, during the optimization phase of the linker, unused functions and symbols may be removed from the final binary. This process is called "dead code elimination" and can significantly reduce the size of the final binary. In other words, it's possible that libgit2.a statically linked against libcrypto.a, but during the dead code elimination phase, the linker determined that some of the functions and symbols from libcrypto.a were not actually used by libgit2.a, and removed them from the final binary. This could explain why libgit2.a is smaller than expected, even though it includes functionality from libcrypto.a.

Myself: