> On 26 Jan 2019, at 23:54, Christian Schoenebeck <schoeneb...@crudebyte.com> > wrote: > > On Samstag, 26. Januar 2019 22:29:08 CET Hans Åberg wrote: >>> No, that's not what the exception sais. The exception applies (and hence >>> the freedom to distribute a Bison generated parser under any arbitrary, >>> different license than GPL) only if the generated parser is not itself a >>> parser generator. This is not as obvious as you might think. It really >>> depends on what his generated parser is capable to do. >> >> From a legal point of view, copyright applies to the code in the skeleton >> file, as the other part is considered machine generated, like in an editor, >> and not copyrightable. > > Yes, the copyright applies to the skeleton. But if the exception does not > apply, and since your Bison generated parser contains the skeleton, the > result > would be that your entire application would be subject to the GPL.
And that was the case in some earlier versions. > So the point of whether or not the exception applies to your Bison generated > parser, is crucial if you intend to use Bison for developing a proprietary > application. Indeed. >>> I give you a simple example: let's say you used Bison to develop a tool >>> which converts source code from one programming language A to B. Now you >>> might think this is not a parser generator. Well, it was obviously not >>> your intention. But now consider somebody uses that conversion tool for >>> converting a parser originally written in programming language A to >>> language B. >>> >>> Right, your Bison generated conversion tool just generated a parser. >> >> A parser generator is not merely a program that generates a parser, but does >> so from a grammar [1]. So the intent of the exception, I think, is that you >> cannot use the skeleton as a part of a program like Bison, but perhaps >> there is the need for some clarification. >> >> 1. https://en.wikipedia.org/wiki/Compiler-compiler > > That Wikipedia article sais "The input *may* be a text file containing the > grammar written in BNF ... , although *other* definitions exist.", > immediately > followed by another type that is analogous to my example: meta compilers. > > It is clear what the intention of the exception was: a) allowing people to > use > Bison for generating parsers also for propriety projects, but preventing b) > that somebody simply takes Bison's skeleton source code, adds the missing > pieces and distributes an entire unGPLed version of Bison. That is how I parse it, too. > But if you intend to use Bison for proprietary purposes, you should be aware > that the current wordings of the exception go far beyond of what was probably > intended for case b) and might thus indeed lead to a potential legal issue > for > your company if your Bison generated parser only has the smallest chance of > being capable to generate another parser. The term "compiler-compiler" felt out of use, replaced by "parser generator", which I also prefer, and other renderings of that latter might be what confuses it. > Many big IT companies out there are using Bison extensively for generating > their arsenal of meta compilers, and if you take the exception text > literally, > and if they even used a GPLv3 Bison version ... well you get the idea. The idea of GPL is to block proprietary use. > And this issue is not just limited to meta compilers. There are many other > non > obvious use cases where you might theoretically get into the same situation. Maybe Akim can clarify. _______________________________________________ help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
