Xcode has a setting called Single-Object Prelink, which allows libraries and frameworks to include the necessary symbols from other libraries so that the underlying libraries do not need to be linked against in an application using your framework.
This repository contains a simple example of how to do this using the standard toolchain from the command line. The Makefiles in this example are deliberately simplistic, and don't use the power of Make, for clarity.
The main executable sop depends on the library libbrisbane. Internally,
libbrisbane uses libadelaide. However neither the libbrisbane headers,
nor the executable sop depend explicitly on libadelaide.
We will build a version of libbrisbane which contains the required symbol
files from libadelaide, meaning that when we build sop, we only need to
link against libbrisbane and so we don't need to know anything about
libadelaide at all.
The key step is on line 19 of brisbane/Makefile:
$(LD) -r -o brisbane-prelink.o b_one.o b_two.o ../adelaide/libadelaide.a
Instead of using the archive tool (ar) to build a static library from the
two object files b_one.o and b_two.o, we instead create a prelink file
linking the two object files against libadelaide. The -r flag tells the
linker to output another object file, rather than a final linked image.
We then use ar to build the final static library, but now it only has one
input, the prelinked object file brisbane-prelink.o.