From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9939 invoked by alias); 5 Nov 2012 21:14:46 -0000 Received: (qmail 9888 invoked by uid 48); 5 Nov 2012 21:14:26 -0000 From: "adivilceanu at yahoo dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/54791] AIX-only: Constructors are not called in main program. Date: Mon, 05 Nov 2012 21:14:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: X-Bugzilla-Severity: major X-Bugzilla-Who: adivilceanu at yahoo dot com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-11/txt/msg00419.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54791 --- Comment #12 from Adi 2012-11-05 21:14:22 UTC --- (In reply to comment #11) > I believe that the G++ front end tries to create a unique name from the first > symbol it sees. I do not now if this is related to the constructor name > collision that you are seeing. What do you mean that it is not related? From my point of view it is. > > Is it valid C++ to define an object with the same name in multiple files? I > cannot tell if you were doing something that happened to work but the behavior > is not clearly defined by the language, or if this is allowed and does not work > on AIX, in which case it is a bug. I agree with you here. This is why I am not insisting that this is a bug. I mean you can expect bad results if you define this. BTW on Linux GNU ld does not let me to define 2 globals with same name. I get a multiple definition error. it seems that the AIX ld is more friendly :(. > > Why does inlining or not inlining affect the name collision? Because if you have a function declared as inline in a header file that gets propagated to multiple source files is ok, but in my case that inline keyword was removed by some $ifdef LINUX and so I end up with having the constructor body defined in the header like this: ClassA::ClassA(){//body}. Now because this is in the header it will propagate to all sources that includes it. So finally I end up with that constructor in multiple constructors sources. This would not happen if the inline keyword have not been removed from it. This was a bug in our code and I removed it. > > Do SVR4/ELF systems mangle each of the constructors uniquely? I thought that > they all would end up in the ".init" sections, which will be concatenated. I am > curious how the calls to the different ctors are disambiguated at link time. I admit I am not very good at compilers(I am a beginner in understanding how compilers are working on various platforms ) so on this question I am going to make assumptions. I am going to test on Linux and see what happens there. > > collect2 could warn, but it currently does not scan the constructor names it > finds for duplicates in its object file scan. A warning would be nice, but I > do not know if it is valid C++ that it should expect. > > I am not sure what you mean by order of initialization of global constructors > across compilation units. This is within one library? GCC has a way to > decorate constructors with a priority to order the constructors. If you mean > order of constructors among multiple shared libraries, that is a separate, > known issue on AIX. Our project has one exe and several shared and static libs. To make the things easier I moved every source file in the exe. Now the problem I have is with the order of the initialization of global objects that reside in multiple object files. I need objects in a source file by constructed first before any other objects in the rest of the files are constructed. You said that I can decorate the constructors with a priority. How to do that ? Before migrating from xlC we used #pragma priority. This is ignored by gcc. We also used -qpriority flag of xlC. Also gcc does not have something like this. Or? Also I tried moving the objects I need constructed in the source files where main() is defined. Still seems that these objects are not constructed first. Also I put the object file where these objects are defined as the first one wen passing to the linker. Still no luck.