Hi ! On Tuesday 09 June 2009 19:15:15 Vladimir Prus wrote:
Alexander Arhipenko wrote:
I have 2 major comment on the updated patch.
In this case, all the symbols marked with BOOST_FILESYSTEM_DECL will be exported from foo library. This could easily break foo library's ABI (in case of migration to the newest boost version etc.), so BOOST_SYMBOL_IMPORT should be defined for gcc as empty macro: # define BOOST_SYMBOL_IMPORT.
Oh, I've simply copied this from our own project settings. I've checked against Qt-4.5 and they use an empty symbol import macro, too. I'll attach an updated patch to the ticket this evening.
The second comment: BOOST_EXCEPTION_EXPORT/IMPORT are intended for re-exporting exceptions from shared library. So, they should be defined for gcc as:
# define BOOST_EXCEPTION_EXPORT BOOST_SYMBOL_EXPORT # define BOOST_EXCEPTION_IMPORT BOOST_SYMBOL_EXPORT
and not as:
# define BOOST_EXCEPTION_EXPORT BOOST_SYMBOL_EXPORT # define BOOST_EXCEPTION_IMPORT BOOST_SYMBOL_IMPORT
That means "__attribute__((visibility("default")))", right ? Okay, I'll add change the patch accordingly.
Oh, now I am confused. How exactly those symbols are to be used? Say, I declare an exception class in a header -- what modifiers should I use? Do we need BOOST_WHATEVER_EXCEPTION_DECL? Maybe you can write up some guidance for library authors?
Yeah, me too ;-)) That whole exception export thing is quite a miracle. Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! Ingenieurgesellschaft für * voice: ++49 511 262926 57 ! Verkehrs- und Eisenbahnwesen mbH * fax : ++49 511 262926 99 ! Lister Straße 15 * juergen.hunold@ivembh.de ! www.ivembh.de * * Geschäftsführer: ! Sitz des Unternehmens: Hannover * Prof. Dr.-Ing. Thomas Siefer ! Amtsgericht Hannover, HRB 56965 * PD Dr.-Ing. Alfons Radtke !