----- Mensaje original ----- De: Robert Ramey <ramey@rrsd.com> Fecha: Sábado, Febrero 11, 2006 10:26 pm Asunto: Re: [boost] [serialization] serialization/nvp.hppmakes autolink kickin

JOAQUIN LOPEZ MU?Z wrote: [...]

...

#include <boost/serialization/nvp.hpp> // rest of serialization headers which must not trigger autolink #include <...>

// declare some function of the serialization // lib (which shouldn't be linked)

int some_f();

int main() { // use the function in whatever manner int x=some_f(); }

Now, if autolink does not get activated, the program should fail as some_f is not linked in. So, in your Jamfile just mark this as a link-fail:

[ link-fail auto_link_not_invoked.cpp ]

I didn't know about link-fail - but I'm still missing something here.

If I refer to a function that is declared in one of my headers - then auto-linking will be triggered. It doesn't matter whether this reference occurs by taking its address or by invoking it by name.

I'm afraid I don't agree here --linkers are not that smart, in fact autolinking is triggered by the appropriate #pragmas only, when you include some header that have those. It doesn't have anything to do with whether the symbols of the lib are used or not. What I propose is that you declare some symbol of the lib *without* using the associate header, which would trigger autolinking. For instance (I haven't actually tested this): // all the serialization headers which mustn't trigger autolink #include <....> // unregister_void_casts is defined by the serialization lib. namespace boost { namespace serialization { class BOOST_SERIALIZATION_DECL(BOOST_PP_EMPTY()) extended_type_info; void BOOST_SERIALIZATION_DECL(BOOST_PP_EMPTY()) unregister_void_casts(extended_type_info *eti); } /* serialization */ } /* boost */ int main() { using namespace boost::serialization; typedef void BOOST_SERIALIZATION_DECL(BOOST_PP_EMPTY()) (* unregister_void_casts_type)(extended_type_info *); unregister_void_casts_type pf=&unregister_void_casts; return 0; } Only when the serialization lib is linked in can this program build OK --so, when autolinking has not been spuriously activated the expected outcome is link failure.

Now I "think" bjam sets up a path to the directory that contains my pre-built boost libraries - so the reference will be found and and the program will link. Its not clear to me that I can suppress this and guarentee that the link will fail.

My comment above applies: autolinking is a #pragma thing, nothing to do with linker finding dangling symbol references --unless I'm grossly mistaken :) Best regards, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost