[fpc-devel] Dynamically Loading Libraries

[Jonas Maebe]

On 11 Nov 2009, at 11:54, Marco van de Voort wrote:

> In our previous episode, Jeppe Johansen said:
>>> This syntax is not possible. The external 'xxx' name 'proc' is  
>>> there for a reason,
>>> for systems with multiple linker namespaces. Moreover there is  
>>> already an
>>> enormous codebase that uses this.
>>>
>> I don't know if I'm making a fool of myself, but what systems?  
>> Skimming
>> the sources, I couldn't find any mention of it in the ELF writers. An
>> external symbol will simply be linked to the first occurrence of a
>> matching symbol in the first shared or static object(unless there's  
>> some
>> name mangling going on that I didn't spot). The COFF writer already  
>> does
>> it the way I suggested.
>
> Windows, Darwin, and afaik Solaris.

The library name is not used on Darwin. You also can't tell the static  
linker that a name should only be looked up in a particular library.  
It simply goes through all libraries/frameworks. Once it finds a  
library/framework that contains the symbol, I think it does record in  
the final binary from which library/framework the symbol comes though  
(so that if at run time multiple libraries export the symbol, the same  
one will always be chosen).


Jonas