Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Date: Fri, 11 Mar 2005 10:21:15 +1300 From: Danny Smith Subject: Re: Possible bug in gas/ld when using .linkonce To: Pavel Tsekov , cygwin@cygwin.com Cc: binutils@sourceware.org Reply-to: Danny Smith Message-id: <001001c525b7$20881800$2d4861cb@DANNY> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7bit References: Pavel Tsekov wrote: > Hello, > > I found this one while playing with Cygwin's code which takes care of > seamless loading of dll functions (autoload.cc). It seems that when a > symbol in a section marked .linkonce is referenced, wrong relocation info > is generated for that symbol. > > For example if you have several symbols - symbol1, symbol2 and symbol3, > - which are placed like this: > > offset name > 0 symbol1 > 3 symbol2 > 15 symbol3 > > References to this symbols will be generated like this: > > symbol1 -> 0 > symbol2 -> 6 > symbol3 -> 30 > > I am attaching a testcase. linkonce.cc is the code which demonstrates the > problem. linkonce1.cc is the same code but with .linkonce directives > removed and doesn't suffer from the problem. Here is also the output of > `objdump -r' on both object files. > I don't think your usage of .linkonce in your example is quite corect. In PECOFF, each linkonce symbol needs to have its own unique section. When you try to put more than one linkonce symbol into a section you get problems like those mentioned here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14808 Secondly, I believe you need to specify a linkonce type (ie, one_only, discard, same_size, same_content) ' Danny -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/