CODEWITHSUNDEEP
cgcclinkerldsymbols
user3860311
user3860311

Reputation: 11

Linking two shared libraries together - undefined reference to symbol

I've got two shared libraries libA and libB, and I want to create a new library libC, that links to both libraries, so I can link my application with -lC instead of -lA and -lB. I can't use -lA and -lB one, because I'd have to fix many packages otherwise.

libB is a precompiled binary.

I tried to run this:

gcc -fPIC -shared -o libA.so A.c
gcc -shared -Wl,--no-as-needed -L. -lA -lB -o libC.so

But when I link my application, that needs libB with -lC I 

App.o: undefined reference to symbol 'SymbolInB'

note: 'SymbolInB' is defined in DSO libB.so so try adding it to the linker command line

libB.so: could not read symbols: Invalid operation

If I run readelf -a libB.so I see the SymbolInB in .dynsym, it is missing in libC.so. So I assume I miss a linking option to resolve the symbols correctly?

Upvotes: 1

Views: 832

Answers (1)

Some programmer dude
Some programmer dude

Reputation: 409472

It doesn't work that way. The functions in libC can use the functions in libA and libB fine, because libC was linked with the other libraries. However, those symbols from libA and libB are not exported from libC, so if you have an application which directly uses functions from libB then you need to link with libB.

Upvotes: 2

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