From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 789 invoked by alias); 19 Oct 2004 10:17:34 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 781 invoked from network); 19 Oct 2004 10:17:32 -0000 Received: from unknown (HELO smtp1.clear.net.nz) (203.97.33.27) by sourceware.org with SMTP; 19 Oct 2004 10:17:32 -0000 Received: from DANNY (t001-m001-u182.acld.clear.net.nz [203.97.72.182]) by smtp1.clear.net.nz (CLEAR Net Mail) with SMTP id <0I5T00HN1TX5EU@smtp1.clear.net.nz> for gcc-patches@gcc.gnu.org; Tue, 19 Oct 2004 23:17:31 +1300 (NZDT) Date: Tue, 19 Oct 2004 10:52:00 -0000 From: Danny Smith Subject: Re: [Patch} Fix dynamic casts across dll boundaries on windows targets To: "Aaron W. LaFramboise" Cc: GCC Patches , Christopher Faylor Reply-to: Danny Smith Message-id: <000601c4b5c4$017f8b90$b64861cb@DANNY> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7bit References: <20041016090410.17530.qmail@web50904.mail.yahoo.com> <4174AF4B.2080307@aaronwl.com> X-SW-Source: 2004-10/txt/msg01594.txt.bz2 Aaron W. LaFramboise wrote: > Danny Smith wrote: > >> 2004-10-16 Danny Smith <> >> >> * config/i386/cygming.h (TARGET_OS_CPP_BUILTINS): Define >> __GXX_MERGED_TYPEINFO_NAMES to 0. > > Does this pessimize the case where typeinfo symbols really are > availible? It pessimizes linking against static libs/objects An example might be when a DLL exports the typeinfo > symbols and they are linkable with auto-import. (Will auto-import > work for this, anyway?) > There is a test case in the original bug report : http://sourceforge.net/tracker/?func=detail&atid=102435&aid=568054&group _id=2435 > Another source for experience in this area is the recent ELF > visibility work. For example, see the secton Caveats in > . The suggestion > here is that if you want RTTI to work, you must take necessary steps > to export typeinfo symbols. Is a similar approach for PE > unreasonable? One of the problems with RTTI vs dllimport is that dllimported objects do not have a constant address at compile time. This creates a problem for static initialisation of, say, another RTTI object or a vtable that has a dllimported typeinfo member. Danny > > Aaron W. LaFramboise