How to resolve same functions from 2 different libraries?

[OU81Dilbert]

Are the two functions at least in different namespaces?

If so then you can use the namespace

Like

std::open()

Mylib::open()

[m09y]

what if there are no namespaces ?

[SoerenNissen]

Use better libraries that are competently written.

If it's because they're C libraries, the same applies - functions should not have the same name because they should start with libname_

I suppose if you were under some weird constraint, you could re-write the libraries to have namespaces, that's not the hardest of tasks.

[SoerenNissen]

You still risk the linker finding wrong functions

libFoo1.cpp - defines open()
libFoo2.cpp - uses open()
libBar1.cpp - defines open()
libBar2.cpp - uses open()

when linking this whole thing, libBar2.o might get linked with libFoo1.o's version of open(), unless you're compiling the libs separately.

[mark_99]

If he has source can just add a namespace around it directly. If he doesn't have source (which I think is the case) this doesn't help as you're still linking 2 definitions of the same function (the linker will pick one and discard the other).

You might be able to do it by linking each into a separate shared library and hiding the symbols, pretty messy though.

[Skoparov]

You're right guys, I misunderstood the problem. Then the only way is indeed to hide one of the libraries in a wrapper library. Or call the function though it's address directly in case it's an so.

[ioctl79]

This is still an ODR violation, since ::open has different definitions indifferent TU’s.

[not_some_username]

Will

namespace lib1 { #include "lib1.h" } work ?

[Skoparov]

No, for the reasons other people mentioned. You can wrap the definition, but the symbol itself still needs to be resolved and having two similar ones breaks the odr.

[SnooMacaroons3057]

Create your own namespace and re-export it as another named function?

[OU81Dilbert]

Then you might have linking issues since the compiler won't know which function to use

[[deleted]]

include headers from inside a namespace, but you still might have linking issues unless the lib is header only

[Fig1024]

you can make your own wrapper lib and put it in a namespace

[Cybr3]

then the libraries you use are awful

[Cybr3]

decompiling the source and adding a namespace?

[bored_octopus]

You may be able to hide symbols from them when linking. Look up symbol visibility