Re: No Bison 3 in untainted macOS installs

[Christian Schoenebeck]

On Samstag, 15. Dezember 2018 17:13:20 CET Uxio Prego wrote:
> > I was unaware that Bison was shipped as part of macOS.  Apple
> > cannot stand the GPLv3, so there's no surprise they are stuck
> > with 2.3, and won't change.  Although there's no license on the
> > generated code.
> 
> I don't see the license in neither generated parsers, but in both
> generated parsers there is the same nice exception note, the
> `special exception` to `distribute that work under terms of your
> choice, so long as [the nesting work is not a parser generator
> itself] or a modified version thereof as a parser skeleton`.

Fact is Apple does not and will not ship Bison 3. I've heard that clearly from 
an Apple engineer a year ago and the reason was indeed the GPLv3. So that's 
why latest Xcode 10.1 still ships Bison 2.3.

There is a license exception in the generated parser source files, that's 
correct, but if you read that exception it sais:

        "As a special exception, you may create a larger work that contains
         part or all of the Bison parser skeleton and distribute that work
         under terms of your choice, so long as that work isn't itself a
         parser generator using the skeleton ..."

Considering the amount of tools Apple has which in turn create new 
intermediate source files, I can imagine why they fear ending up with GPL3 
issues was too dangerous.

Best regards,
Christian Schoenebeck