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xcodelinkerclangxcframework

dynamic framework: how to hide the local symbols?

I am building an .xcframework which contains an iphonesimulator and iphoneos frameworks. There is some Swift code, and some C++ code, which is linked into a shared object (Mach-O 64-bit dynamically linked shared library arm64). I build my C++ with -fvisibility=hidden, and only the symbols that I explicitly mark, are exported. But, when I run nm -gC, I see all kinds of symbols that are still there – and they are visible even in the iOS app that is built using this framework. For example, I have an inner class Secret (it is only used in one cpp file). And nm -gC shows me (and all hackers out there)

00010292 t Secret::getString() const

Is there a way to hide this and other sensitive information?

And, on the other hand, how can I keep the auto-generated _AlexSDKVersionNumber exported?

Solution

  • You should configure your project settings correctly for Stripping to hide internal names.

    Go to Your target > Build Settings > Deployment:

    1. Set Deployment Postprocessing to YES to enable Stripping.

    2. Set Strip Style to Non-Global Symbols.

    Now nm should provide global (external) symbols only for your binary.