C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  (L)GPL and C++ templates issue Goto page 1, 2, 3  Next          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message Maciej Sobczak Guest Posted: Mon Oct 18, 2004 8:32 pm    Post subject: (L)GPL and C++ templates issue Hi, I think this is a good forum to ask this question. The problem affects C++ programmers that release libraries with LGPL licence and those who use such libraries in non-GPL products. Let's imagine a library containing some template definitions. The library has a LGPL license. I'm not concerned about what is the "derivative work" and was is not. I have problem with something different. The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. This is what FSF calls "freedom" and that's basically good. Let's now suppose that someone releases a product (not necessarily GPL) that uses this LGPLed library. Now, I'm the user of this software and, by inclusion, the user of the library. I want to benefit from my basic rights to modify (and possibly improve) this library. Let's say that I got the library source code and modified it. What next? I cannot compile it in separation and link with the rest of the product (or just link it dynamically), because I have modified the template code and to see my modifications in the library I have to instantiate the template, which means recompile the main product, which means... yes, I need the source code of the product, which is not necessarily open source. We can generalize this problem to any technology with the following property: If module A uses module B, then module A's source code must be re-processed in order for the module B's modifications to take effect. C++ with templates has this property (module B is a template library) and I can imagine that there can be (if not today then in the future) tons of other software technologies where this property is also true. My conclusion is that (L)GPL license on the C++ library that has at least one template definition *forces* every software using this library to be distributed with source code, because otherwise the user cannot benefit from his basic rights to modify this LGPLed library, which is a clear violation of the license. This in turn means that LGPL does not meet its intended goals. What about libraries without template definitions? a) They will have them in next versions, which must be LGPL. b) I want to modify those libraries (and I have the right to do so) by adding the template definitions. The modified library must be LGPL. My following conclusion is that (L)GPL license was invented without any thought about software technologies other than C with its traditional compile&link production cycles, where modules can be compiled in separation. I'm not really versed in (english) legalese, so I ask for your comments on this. I may be totally wrong and possibly messed up everything, but as a C++ programmer who from time to time releases C++ libraries containing template definitions I'm a little bit concerned. At the moment I steer away from LGPL license, and the above concern is one of the reasons. -- Maciej Sobczak : http://www.msobczak.com/ Programming : http://www.msobczak.com/prog/ [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ron Natalie Guest Posted: Tue Oct 19, 2004 4:25 pm    Post subject: Re: (L)GPL and C++ templates issue Maciej Sobczak wrote: Quote: The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. This is what FSF calls "freedom" and that's basically good., No, it doesn't assure that. It places restrictions on what people can do with the code. It's RMS's idea of freedom. In actuallity the BSD/ BOOST/libtiff etc... libraries are much more free (they pretty much just say do what you want with this but leave the copyright info intact and don't sue us). Quote: Let's now suppose that someone releases a product (not necessarily GPL) that uses this LGPLed library. If you modify the library code, you must give the modified source code out as specified in the LGPL license. Quote: My conclusion is that (L)GPL license on the C++ library that has at least one template definition *forces* every software using this library to be distributed with source code, because otherwise the user cannot benefit from his basic rights to modify this LGPLed library, which is a clear violation of the license. You keepputting the (L) in parens like you don't know if you are talking about the GPL or the Lesser GPL. What you are saying is true of the GPL. It's not true of the LGPL. The LGPL lets you use the library but only exposes the "must-give-source" aspects to changes made to library itself. Quote: This in turn means that LGPL does not meet its intended goals. You don't seem to understand the FSF goals. Their goal isn't to provide a flexible open source licensing scheme, it's a stated goal to kill off all proprietary software. Go to FSF.org, open up the licenses page, and read some of RMS's rants on why you shouldn't use the LPGL. Quote: My following conclusion is that (L)GPL license was invented without any thought about software technologies other than C with its traditional compile&link production cycles, where modules can be compiled in separation. I'm not even sure it had C in mind. The whole GPL boondoggle came from RMS getting (in his percetion) screwed over work he did on LISP at MIT. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top kanze@gabi-soft.fr Guest Posted: Wed Oct 20, 2004 4:16 pm    Post subject: Re: (L)GPL and C++ templates issue Maciej Sobczak <no_spam (AT) no_spam (DOT) com> wrote Quote: I think this is a good forum to ask this question. The problem affects C++ programmers that release libraries with LGPL licence and those who use such libraries in non-GPL products. Let's imagine a library containing some template definitions. The library has a LGPL license. I'm not concerned about what is the "derivative work" and was is not. I have problem with something different. The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. This is what FSF calls "freedom" and that's basically good. Allowing any one to make any possible modification, without requiring them to change the name, or at least make it clear that the software has been modified, is good? My experience with GPL software is that it is only good when you can ensure that the freedom hasn't actually been used: I download g++ from the g++ site, and they do have source code control, and don't let just anyone hack any modification in without verifying that it works. The "control" aspect of quality control is important if you want the quality. (This isn't to say that GPL is always bad. Just that, like most things, there are cases where it is good, cases where it is bad, and a lot of cases where it really doen't matter. G++ is g++, regardless of the license -- GPL doesn't make it any better, but as long as the g++ team do control the sources, and wild or unsupported copies with unknown modifications don't start floating around, GPL doesn't make it worse.) Quote: Let's now suppose that someone releases a product (not necessarily GPL) that uses this LGPLed library. In that case, if I understand correctly, the product is controlled by its licence. The fact that it uses an LGPLed library is irrelevant. Quote: Now, I'm the user of this software and, by inclusion, the user of the library. I want to benefit from my basic rights to modify (and possibly improve) this library. From what I understand of LGPL, you don't have any. Quote: Let's say that I got the library source code and modified it. What next? I cannot compile it in separation and link with the rest of the product (or just link it dynamically), because I have modified the template code and to see my modifications in the library I have to instantiate the template, which means recompile the main product, which means... yes, I need the source code of the product, which is not necessarily open source. Exactly. That is the whole point of LGPL (as opposed to GPL). Note that templates are irrelevant in the issue. If I deliver you a statically linked program using a LGPL licence, you can't do anything with it either. If I've sold you a product, and I stand behind my product, this is almost a necessary condition. Quote: We can generalize this problem to any technology with the following property: If module A uses module B, then module A's source code must be re-processed in order for the module B's modifications to take effect. C++ with templates has this property (module B is a template library) and I can imagine that there can be (if not today then in the future) tons of other software technologies where this property is also true. My conclusion is that (L)GPL license on the C++ library that has at least one template definition *forces* every software using this library to be distributed with source code, because otherwise the user cannot benefit from his basic rights to modify this LGPLed library, which is a clear violation of the license. This in turn means that LGPL does not meet its intended goals. I think that there has been some discussion concerning what LGPL means with regards to templates. From what I understand of LGPL, however, the goal is precisely not to contaminate the code which uses it. The intent of LGPL is precisely that I can use it without my code falling under GPL. The fact that I link with an LGPL library does NOT give you the right to modify my code. Quote: What about libraries without template definitions? a) They will have them in next versions, which must be LGPL. b) I want to modify those libraries (and I have the right to do so) by adding the template definitions. The modified library must be LGPL. There is no problem with modifying the libraries. But code which is linked with the libraries is NOT GPL, nor even LGPL. That's the whole purpose of LGPL. Quote: My following conclusion is that (L)GPL license was invented without any thought about software technologies other than C with its traditional compile&link production cycles, where modules can be compiled in separation. I'm not really versed in (english) legalese, so I ask for your comments on this. I may be totally wrong and possibly messed up everything, but as a C++ programmer who from time to time releases C++ libraries containing template definitions I'm a little bit concerned. At the moment I steer away from LGPL license, and the above concern is one of the reasons. I think that there are questions concerning templates and LGPL. But the questions go in the opposite direction -- with templates, I'm using source code, not a "library" in the classical sense. And traditionally, LGPL only gives the exception from GPL when I link object code. On the other hand, all LGPL libraries I've know have had header files. The header files may not result in any code being generated by the compiler, but they are source code which I incorporate into my program. And traditionally, it has been understood that this is OK. I'm not a lawyer, but from a pratical point of view, I think that the intent behind LGPL is clear, templates or not. As I understand it, originally, any use of GPL'ed code in my program meant that my program must also be GPL. Since then, a number of exceptions have been defined: - I can use GPL'ed programs in the generation of my code without "contamination". (The fact that I compile my program with g++ doesn't mean that my program must be GPL.) - I can deliver complete GPL'ed programs as part of a larger product, provided there is sufficient separation of the program (and presumably the sources). (Sun Workshop comes with emacs. As long as the emacs is in a separate directory, and none of the emacs sources were used in the elaboration of the rest of the product, Sun Workshop does not become GPL.) - LGPL was created so that linking with the libraries delivered with a compiler doesn't contaminate my product. Libraries normally also contain header files, and traditionally, including those has not meant contamination either, although I'm not sure what the legalese says about this. - Finally, some software is available under several licences -- if I use the GPL'ed version of Ghostscript in my code, my code must also be GPL, but I can also purchase a version from Adallin with a non GPL licence, and use it without my code necessarily becoming GPL. -- James Kanze GABI Software http://www.gabi-soft.fr Conseils en informatique orientée objet/ Beratung in objektorientierter Datenverarbeitung 9 place Sémard, 78210 St.-Cyr-l'École, France, +33 (0)1 30 23 00 34 [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top johnchx Guest Posted: Wed Oct 20, 2004 4:18 pm    Post subject: Re: (L)GPL and C++ templates issue Maciej Sobczak <no_spam (AT) no_spam (DOT) com> wrote Quote: Let's now suppose that someone releases a product (not necessarily GPL) that uses this LGPLed library. Now, I'm the user of this software and, by inclusion, the user of the library. I want to benefit from my basic rights to modify (and possibly improve) this library. Let's say that I got the library source code and modified it. What next? I cannot compile it in separation and link with the rest of the product (or just link it dynamically), Sure you can, *if* the proprietary application actually conforms to the LGPL. Quote: because I have modified the template code and to see my modifications in the library I have to instantiate the template, which means recompile the main product, which means... yes, I need the source code of the product, which is not necessarily open source. Which means that the application violates the LGPL. To conform to the LGPL, an application must ensure that all object code covered by the LGPL resides in a distinct binary module (or modules) so that it can be separately re-compiled and re-linked into the proprietary application. In the C++ context, this means that all instantiations of LGPL'ed function templates (including member functions of class templates) must reside in a distinct GPL/LGPL-only module. No LGPL'ed function template instantiations may be present in a proprietary binary module. Class template instantiations (*not* including member functions) are essentially analagous to struct definitions, and follow the same rules. (IIRC, LGPL'ed struct definitions are traditionally allowed to be #included in non-GPL/LGPL modules.) This does constrain somewhat the changes that can be made to the LGPL'ed class template definition, but successful re-linking always depends on not breaking "ABI-compatibility", so there is no real loss of freedom here. Further wrinkles, like template templates and template members of class templates, are left as an exercise for the reader. :-) [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Hyman Rosen Guest Posted: Wed Oct 20, 2004 4:30 pm    Post subject: Re: (L)GPL and C++ templates issue Ron Natalie wrote: Quote: Maciej Sobczak wrote: The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. No, it doesn't assure that. It doesn't? In what way can it happen that a user of (L)GPL code does not have full rights to modify that code? Quote: It places restrictions on what people can do with the code. It's RMS's idea of freedom. In actuallity the BSD/BOOST/libtiff etc... libraries are much more free As MS wrote above, the purpose of the (L)GPL is to give *all users* the ability to examine, modify, and redistribute the code. The "more free" licenses permit some users to deny others these abilities. That is, they can take the code, examine it, modify it, redistribute it, and prohibit their recipients from examining this code, modifying it, or redistributing it. That certainly may be what some people like, but those downstream second-class users now have much less freedom. Quote: The LGPL lets you use the library but only exposes the "must-give-source" aspects to changes made to library itself. But "must-be-able-to-relink" is also part of the LGPL requirements. Since templated libraries can't really be used that way, that vitiates one of the goals of the LGPL. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Hyman Rosen Guest Posted: Thu Oct 21, 2004 4:04 pm    Post subject: Re: (L)GPL and C++ templates issue johnchx wrote: Quote: No LGPL'ed function template instantiations may be present in a proprietary binary module. Yep. The GNAT (GNU Ada) runtime library has the same issues, since Ada has generic instantiation. They solve it by extending further special permissions for files which contain such instantiations as the result of compilation, so that they have a special exemption. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Hyman Rosen Guest Posted: Thu Oct 21, 2004 4:35 pm    Post subject: Re: (L)GPL and C++ templates issue [email]kanze (AT) gabi-soft (DOT) fr[/email] wrote: Quote: Allowing any one to make any possible modification, without requiring them to change the name, or at least make it clear that the software has been modified, is good? That is not allowed. Section 2b states You must cause the files modified to carry prominent notices stating that you changed the files and the date of any change. Quote: My experience with GPL software is that it is only good when you can ensure that the freedom hasn't actually been used That's pretty silly. The whole EGCS fork would have been impossible without the rights granted by the GPL. And any number of companies have modified gcc to compile to custom processors. Quote: Note that templates are irrelevant in the issue. If I deliver you a statically linked program using a LGPL licence, you can't do anything with it either. They are very relevant. See sections 5 and 6 of the LGPL. Object files which contain instantiations of LGPLed functions may (depending on the law, not just on technical issues) be considered derived works, and may only be distributed under the LGPL, which means with full source code. Furthermore, programs which link against LGPLed libraries must use dynamic linking or must be shipped in a form which allows them to be relinked. Quote: The header files may not result in any code being generated by the compiler, but they are source code which I incorporate into my program. And traditionally, it has been understood that this is OK. This permission is given explicitly by the LGPL. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top johnchx Guest Posted: Thu Oct 21, 2004 5:14 pm    Post subject: Re: (L)GPL and C++ templates issue Ron Natalie <ron (AT) sensor (DOT) com> wrote Quote: Maciej Sobczak wrote: The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. This is what FSF calls "freedom" and that's basically good., No, it doesn't assure that. It places restrictions on what people can do with the code. It's RMS's idea of freedom. Plea to moderators: isn't a flamewar on the merits and evils of the GPL, LGPL and the FSF wildly off-topic here? Could we nip this in the bud? The OP has a legitimate C++ question about the interaction between the C++ template inclusion model and the LGPL. I hope we can discuss that without getting into a 200-post thread about what "freedom" means. --jc [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Wil Evers Guest Posted: Thu Oct 21, 2004 5:25 pm    Post subject: Re: (L)GPL and C++ templates issue In article <4174046c$1_2 (AT) news (DOT) bluewin.ch>, Maciej Sobczak wrote: [snip] Quote: My conclusion is that (L)GPL license on the C++ library that has at least one template definition *forces* every software using this library to be distributed with source code, because otherwise the user cannot benefit from his basic rights to modify this LGPLed library, which is a clear violation of the license. This in turn means that LGPL does not meet its intended goals. [snip] Quote: I'm not really versed in (english) legalese, so I ask for your comments on this. I may be totally wrong and possibly messed up everything, but as a C++ programmer who from time to time releases C++ libraries containing template definitions I'm a little bit concerned. At the moment I steer away from LGPL license, and the above concern is one of the reasons. I agree; the LGPL is unsuitable for template libraries. The gcc folks are aware of this; libstdc++, for example, is GPL, not LGPL, but with the following addition: As a special exception, you may use this file as part of a free software library without restriction. Specifically, if other files instantiate templates or use macros or inline functions from this file, or you compile this file and link it with other files to produce an executable, this file does not by itself cause the resulting executable to be covered by the GNU General Public License. This exception does not however invalidate any other reasons why the executable file might be covered by the GNU General Public License. - Wil [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top kanze@gabi-soft.fr Guest Posted: Thu Oct 21, 2004 5:40 pm    Post subject: Re: (L)GPL and C++ templates issue Hyman Rosen <hyrosen (AT) mail (DOT) com> wrote Quote: Ron Natalie wrote: Maciej Sobczak wrote: The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. No, it doesn't assure that. It doesn't? In what way can it happen that a user of (L)GPL code does not have full rights to modify that code? It places restrictions on what people can do with the code. It's RMS's idea of freedom. In actuallity the BSD/BOOST/libtiff etc... libraries are much more free As MS wrote above, the purpose of the (L)GPL is to give *all users* the ability to examine, modify, and redistribute the code. The original intent of the (L)GPL, as I understand it, was specifically to allow people to use free software in the development of commercial programs, e.g. to be able to compile and link using gcc (or g++) even if the program was to be sold, or the sources not made available, later. In the end, it was more or less to bring the free development tools in line with the commercial ones -- there has never been any question that linking with the libc provided by Sun with Solaris places any restrictions on my software. Unless this is possible with g++, of course, g++ becomes pretty much unusable for many people. I believe, in fact, that LGPL originally came to be because the GPL on the libraries furnished with gcc was making gcc pretty much unusable. (There is the additional problem that corporate lawyers do not always understand the intent or purpose of these licenses, and sometimes seem incapable of understanding what they mean. I know of one case where the corporate legal departement refused to allow us to use g++, even though we were delivering full sources to the customer, and the customer had no problem with GPL applying to those sources, since he wasn't distributing the software anywhere else.) Quote: The "more free" licenses permit some users to deny others these abilities. That is, they can take the code, examine it, modify it, redistribute it, and prohibit their recipients from examining this code, modifying it, or redistributing it. That certainly may be what some people like, but those downstream second-class users now have much less freedom. There are many complicated issues that have to be balanced. If you take pride in the quality of your work, you certainly don't want people downstream hacking it in any sloppy fashion, and then redistributing it as if it were the original. I doubt that the people at g++ were happy when an internal development version was pawned off as a 2.96 release. And Knuth is very clear about it in the license to TeX -- you can do what you want with the sources, but you cannot call the results TeX. You may consider that taking away freedom, but I consider it pride in your work. (But of course, both positions are ridiculous oversimplifications.) Note too that the "freedom" is largely imaginary. If you understand the algorithms and the programming techniques involved, it is usually quicker and easier to develop something new from scratch that it is to modify undocumented existing source code. And since the license doesn't require documentation (and I would be at a loss as to how to formulate text so that the required documentation would be adequate), it's really as if you didn't have the source code if you want to make a modification of any quality. (This obviously depends on the size of the project, and the type of modification.) Quote: The LGPL lets you use the library but only exposes the "must-give-source" aspects to changes made to library itself. But "must-be-able-to-relink" is also part of the LGPL requirements. Since templated libraries can't really be used that way, that vitiates one of the goals of the LGPL. The "must-be-able-to-relink" seems to contradict the expressed intent of: "We use this license for certain libraries in order to permit linking those libraries into non-free programs." In fact, of course, I suspect that this clause is widely ignored. There is, after all, commercial software available for Linux, and what alternative do you have on Linux, other than to link with a library that is distributed under LGPL? -- James Kanze GABI Software http://www.gabi-soft.fr Conseils en informatique orientée objet/ Beratung in objektorientierter Datenverarbeitung 9 place Sémard, 78210 St.-Cyr-l'École, France, +33 (0)1 30 23 00 34 [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Hyman Rosen Guest Posted: Fri Oct 22, 2004 5:14 pm    Post subject: Re: (L)GPL and C++ templates issue [email]kanze (AT) gabi-soft (DOT) fr[/email] wrote: Quote: The "must-be-able-to-relink" seems to contradict the expressed intent of: "We use this license for certain libraries in order to permit linking those libraries into non-free programs." The right of all users to be able to examine, modify, and redistribute is at the core of what the FSF believes, and the LGPL expresses that as much as the GPL does. The LGPL allows more latitude to proprietary vendors, in that they can link these libraries into their code and not cause that code to fall under the same license, but the core freedoms with regard to the library itself are preserved. LGPL exists for the cases where it is clear that a GPLed version would not be used at all. In terms of freedom, it is truly "lesser". Quote: In fact, of course, I suspect that this clause is widely ignored. There is, after all, commercial software available for Linux, and what alternative do you have on Linux, other than to link with a library that is distributed under LGPL? If these are shared libraries, then there is no problem, since modified ones can simply be put in place. But if you do come across cases where the LGPL on a library owned by the FSF is being ignored, why don't you contact them? I'm sure they'd be interested. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ron Natalie Guest Posted: Sat Oct 23, 2004 2:16 pm    Post subject: Re: (L)GPL and C++ templates issue {Please ensure thart follow-ups contain C++ content and do not degenerate into discussion of the terms of (L)GPL). Hyman Rosen wrote: Quote: The right of all users to be able to examine, modify, and redistribute is at the core of what the FSF believes, Redistribution is very seriously restricted. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ben Hutchings Guest Posted: Sat Oct 23, 2004 2:19 pm    Post subject: Re: (L)GPL and C++ templates issue [email]kanze (AT) gabi-soft (DOT) fr[/email] wrote: Quote: Hyman Rosen <hyrosen (AT) mail (DOT) com> wrote in message news:<1098207931.824248 (AT) master (DOT) nyc.kbcfp.com>... Ron Natalie wrote: Maciej Sobczak wrote: The most fundamental thing in (L)GPL is to ensure that every user of the software has full rights to modify (and possibly improve) the code. No, it doesn't assure that. It doesn't? In what way can it happen that a user of (L)GPL code does not have full rights to modify that code? It places restrictions on what people can do with the code. It's RMS's idea of freedom. In actuallity the BSD/BOOST/libtiff etc... libraries are much more free As MS wrote above, the purpose of the (L)GPL is to give *all users* the ability to examine, modify, and redistribute the code. The original intent of the (L)GPL, as I understand it, was specifically to allow people to use free software in the development of commercial programs, e.g. to be able to compile and link using gcc (or g++) even if the program was to be sold, or the sources not made available, later. In the end, it was more or less to bring the free development tools in line with the commercial ones -- there has never been any question that linking with the libc provided by Sun with Solaris places any restrictions on my software. Unless this is possible with g++, of course, g++ becomes pretty much unusable for many people. I believe, in fact, that LGPL originally came to be because the GPL on the libraries furnished with gcc was making gcc pretty much unusable. The C/C++ run-time library (libgcc_s) and the whole of the standard C++ library (libstdc++) included in GCC are under a special licence, the "Runtime GPL". This is the GPL plus an exception that allows their code to be used "as part of a library" without the usual "copyleft" or "viral" conditions of the GPL or the LGPL. <snip> Quote: I doubt that the people at g++ were happy when an internal development version was pawned off as a 2.96 release. The absurdity is that GCC "2.96" was distributed by Red Hat, which employs many of the core GCC developers (following its purchase of Cygnus). The left hand didn't know what the right hand was doing, it seems. <snip> Quote: The LGPL lets you use the library but only exposes the "must-give-source" aspects to changes made to library itself. But "must-be-able-to-relink" is also part of the LGPL requirements. Since templated libraries can't really be used that way, that vitiates one of the goals of the LGPL. The "must-be-able-to-relink" seems to contradict the expressed intent of: "We use this license for certain libraries in order to permit linking those libraries into non-free programs." In fact, of course, I suspect that this clause is widely ignored. There is, after all, commercial software available for Linux, and what alternative do you have on Linux, other than to link with a library that is distributed under LGPL? The key is that the linking is done dynamically, not statically. I think most proprietary software for Linux does not breach the copyright of LGPL'd libraries. -- Ben Hutchings If you seem to know what you are doing, you'll be given more to do. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Gabriel Dos Reis Guest Posted: Sun Oct 24, 2004 4:11 am    Post subject: Re: (L)GPL and C++ templates issue [email]kanze (AT) gabi-soft (DOT) fr[/email] writes: Quote: Unless this is possible with g++, of course, g++ becomes pretty much unusable for many people. I believe, in fact, that LGPL originally came to be because the GPL on the libraries furnished with gcc was making gcc pretty much unusable. I noted you switched from "g++" to "gcc" in your last sentence; I wanted to add that the libstdc++ coming with g++ does not use LGPL. It uses "GPL with runtime exception". http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/license.html -- Gabriel Dos Reis [email]gdr (AT) cs (DOT) tamu.edu[/email] Texas A&M University -- Computer Science Department 301, Bright Building -- College Station, TX 77843-3112 [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Markus Elfring Guest Posted: Sun Oct 24, 2004 4:12 am    Post subject: Re: (L)GPL and C++ templates issue Quote: To conform to the LGPL, an application must ensure that all object code covered by the LGPL resides in a distinct binary module (or modules) so that it can be separately re-compiled and re-linked into the proprietary application. In the C++ context, this means that all instantiations of LGPL'ed function templates (including member functions of class templates) must reside in a distinct GPL/LGPL-only module. No LGPL'ed function template instantiations may be present in a proprietary binary module. Is it applicable to divide a license between the raw data structures and the executable code (functions, methods) that works with them? How do you think about inlined code in this context? May macros/inline functions be used by a LGPL'ed library in their public interface? Regards, Markus [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ Language (Moderated) All times are GMT Goto page 1, 2, 3  Next Page 1 of 3   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.