Re: [Jack-Devel] [Fwd: Re: [Guitarix-developer] jack session crash]

On Wed, Nov 2, 2011 at 3:14 PM, hermann <[hidden]> wrote:

> To make the mess complete, the weak linking doesn't work as
> advertised by the jackd developers. At least my understanding and
> that of the ubuntu / debian packagers seems to be:
>
>  1) you can compile and link with either package (works)
>  2) when the function is not in the shared library used at
>     runtime, the function address will be 0. Does NOT work.
>
> 2) only works when the shared lib used at runtime is the same as
> the one used when linking. The compiler / linker will set the address
> of a weak function that it does not find in the libraries supplied to
> constant 0. Even when the funktion is in the library which is used at
> runtime, there will be no runtime linking.

I have no idea what you are trying to say here.

If the function prototype was declared with weak linkage, and the
symbol is not found at runtime, then this condition:

     if (function_name)

will evaluate to false.

ardour is doing this all the time.

its fairly clear from your test program that you have not include
weakjack.h which is required to get weak linkage declarations.

--p

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