There's a brief coverage of some of the problems with this idea in http://www.openwall.com/lists/musl/2012/12/08/4
The relevant part is this bit: "But now you're potentially using two different versions of libc in the same program; if implementation-internal data structures like FILE or the pthread structure are not identical between the 2 versions, you'll hit an ABI incompatibility, despite the fact that these data structures were intended to be implementation-internal and never affect ABI. Even without that issue, you have issues like potentially 2 copies of malloc trying to manage the heap without being aware of one another, and thus clobbering it."
It's worth reading the whole thread as there a couple of other directly relevant bits. I've wanted to do the same as you in the past, but the number of possible (/probable) issues was quite discouraging.
Hello there,
Is it at all possible to link musl's libc.a statically into a shared lib? After a lot of trying I either get relocation errors (when using musl-gcc built on say centos7) as such (http://stackoverflow.com/questions/38251344/musl-fails-to-link-libc-a-into-shared-library) or hidden symbols not being defined like below (when using Alpine linux) :
/home/buildozer/aports/main/musll/src/musl-1.1.12/src/ldso/x86_64/tlsdesc.s:36: undefined reference to `__tls_get_new'
/usr/lib/gcc/x86_64-alpine-linux-musl/5.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: tgt/Linux-x86_64/mylib/lib/mylib.so: hidden symbol `__tls_get_new’ isn't defined
/usr/lib/gcc/x86_64-alpine-linux-musl/5.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: final link failed: Bad value
collect2: error: ld returned 1 exit status
Makefile:58: recipe for target ‘tgt/Linux-x86_64/mulib/lib/mylib.so’ failed
make: *** [tgt/Linux-x86_64/mylib/lib/mylib.so] Error 1I understand this might conflict when someone tries to link against this and libc.so from a binary, however would it be possible somehow to mangle all the libc calls internally inside the shared lib? Is there a tool that would be able to do this? It would be really nice to have a portable shared lib that has libc built in.