Bug#848368: llvm-toolchain-3.9: Please add ELF symbols versions to the libraries

[Rebecca N. Palmer]

On 22/01/17 21:07, Sylvestre Ledru wrote:
> , you haven't pass the arg to LDFLAGS to make sure that libclang or
> liblldb get it,
> is that on purpose?

My original intent was to avoid passing it to those parts of LLVM that
already use a "version" (actually which-symbols-are-public) script, as
I suspect having two version scripts is an error; you're right that
there might be other parts of LLVM that would benefit.

>> - Are the symbols versioned? For this creating a temporary symbols files is 
>> enough. Ping me if you don't know how to do this.
> Just libclang is (the C lib).
> I haven't done it for the rest because it is C++ and not commitment
> from upstream on API stability

The lack of API stability is exactly why we need symbol versioning
(otherwise we could just make everything use 3.9).  We're not proposing
to ship this .symbols file (which would be a compatibility statement),
just use it to check whether symbol versioning was successfully enabled.

>> - Install and test LLVM 3.9 with stuff built with previous versions, like for 
>> example kdevelop ;-) Everything should just work.

kdevelop (#846410) has already been fixed by moving it to all-3.9; if
you need a test case, I suggest the pocl-opencl-icd + blender one above.