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I've heard this said before. Why would someone want this? AFAIK the GPL isn't really relevant unless you're modifying and redistributing GCC itself. Even if you

I've heard this said before. Why would someone want this? AFAIK the GPL isn't really relevant unless you're modifying and redistributing GCC itself. Even if you use modified GCC internally for compiling for-profit software you just need to allow the employees who use GCC to see your modified code, which doesn't seem like a big deal since you already trust them with your application code.

saagarjha 6y ago
Because Apple modifies and distributes LLVM in their proprietary developer tools.
redwatch 6y ago
It is somewhat easy to work and modify llvm tools: an optimization pass for instance. Also, LLVM tools were designed to be interchangeable. One can pick specific parts of LLVM and integrate into the workflow of others.
redis_mlc 6y ago
Because Apple is intensely allergic to the GPL. The reasons are: - As somebody else mentioned, Apple redistributes developer tools, clang being the poster child - Since they releases OS products, they don't want to co-mingle their software with GPL code. (So they use an older bash on Mac OS X.) - fear of an Apple developer quietly copying GPL source into a commercial product (well-founded, actually) - Apple Legal exerting an "abundance of caution" on IP - at this point, it's institutional. When I worked there, Linux and MySQL were forbidden, for example, but that has relaxed recently. Also, I think you misunderstand the GPL. If you distribute modified gcc, anybody receiving it can ask for sources. So employees plus end-users. (One of the strangest examples is that Yamaha uses real-time linux in their synths, and you can download the GPL portions. I can't imagine a musician ever wanting to do that!) Source: ex-Apple.
- sjwright 6y ago
  > Apple is intensely allergic to the GPL. Their actual marketplace behaviour demonstrates that they're allergic to GPL version 3 specifically, not the GPL or copyleft in general.
  - stephen_g 6y ago
    Which I think is reasonable - I do think GNU went too far with the version 3 licenses. I think Rob Landley's perspective is interesting, where he was involved with Busybox and the legal action against companies violating the GPL with that software, but later created an alternative to Buysbox that was more permissively licensed because he felt that the whole GPL legal action exercise had been counter-productive for open source software in general (net effect of not encouraging many companies to contribute back but instead just making many companies avoid GPL-licensed software altogether).
  - saagarjha 6y ago
    They’re fairly allergic to copyleft these days; I can’t recall them adopting a new project with any version of GPL for quite a while.
    - sjwright 6y ago
      There aren't so many GPL 2.0–only projects out there to adopt.
- pcwalton 6y ago
  > (So they use an older bash on Mac OS X.) Presumably you mean that Apple specifically avoids GPL3 then, because bash was never distributed under anything other than the GPL to my knowledge. Bash moved from GPL2 to GPL3 though.
  - jabl 6y ago
    They've been on a general GPL purge rampage, in each macOS release there's less and less GPL software (there was some blog post with numbers). As for bash, in the latest release the default shell is zsh, though I think the old bash is still there, although clearly on the way out.
- alerighi 6y ago
  Isn't Apple clang open source anyway? So what is really the point? Even distribuiting GPL software isn't a big deal, nowadays even Microsoft does that, shipping an entire Linux distribution in Windows! There are no technical motivations for not using GPL software, you can do that as long you respect the GPL license (i.e. release the modified source code). I think that what Apple does is more a policy to go against the FOSS community for political reasons that anything else, and to me is bad, in a world where now even Microsoft is opening up a lot to the open source world.
  - throwaway09922 6y ago
    [Ex FAANG here] > I think that what Apple does is more a policy to go against the FOSS community for political reasons that anything else This is the real reason why FAANGs push for non-GPL licenses. GPL's end goal is to build a community where developers, testers, power users and regular users connect with each other and share knowledge, not just code. FAANGs want to wedge themselves as the middleman between developers and end users. They view such community as a threat.
    - andrekandre 6y ago
      > FAANGs want to wedge themselves as the middleman between developers and end users. well... ostensibly that is where the money can be made (at the point they meet the end-user)
  - belorn 6y ago
    > Isn't Apple clang open source anyway? So what is really the point? The best explanation I have seen is the speculation that apples software patents are seen as a critical part of apples business model and competitive strategy, especially 10 years ago when their anti-gpl stance was formed. GPLv3 patent clause adds risk, especially the patent agreement clause, and if you intend to spend millions over software patent lawsuits then staying away from GPLv3 looks much more reasonable, especially if you ask the patent lawyers.
- tobias3 6y ago
  Specifically GPLv3. One reason, I think, is the tivoization clause. Users must be able to modify GPLv3 software and then run the modified version. If they included a GPLv3 bash into iOS, iOS users must be able to modify bash and use the modified one instead. Your synth example is a good one actually. As a synth owner, I'd probably love to be able to replace the software on it with modified versions from the Internet or modify it myself. Linux is GPLv2, though. How that morphed into disallowing GCC, idk. Maybe they want to prohibit users from installing their own compilers at some point? Others have mentioned the patent clause. That one seems reasonable as well. In fact LLVM uses the Apache 2.0 license which also has a patent grant, albeit with a smaller scope. Apple could probably file a patent for a feature, then get a university department to implement that feature, then sue other LLVM users (like Sony). With the GPLv3 that loophole does not exist.
- jart 6y ago
  Apple's only overreacting due to deal Jobs made in the late 90's.
kevin_thibedeau 6y ago
You don't technically have to disclose internal mods to all employees because everyone is part of a single legal entity and no binary distribution occurs.
- marcoperaza 6y ago
  Perhaps but then you will kick yourself the first time you want to give a customer or business partner access to your modifications. Unforeseen business needs or opportunities can always make you need to distribute a tool you previously thought would only be internal. I'm not saying this is a slam-dunk reason to not use GPL tools, but I'm just pointing out that there is a legitimate worry here that is not fully alleviated by your point.
  - deleted 6y ago
    [deleted]
NobodyNada 6y ago
One argument I've heard before is that GCC's architecture is intentionally designed to make it difficult to extend GCC or integrate it into other tools such as IDEs, because that sort of modularlization could enable interoperability with non-GPL software. I'm not sure whether this argument has any merit, but see e.g. this email from ESR: https://gcc.gnu.org/legacy-ml/gcc/2014-01/msg00209.html https://gcc.gnu.org/legacy-ml/gcc/2014-01/msg00209.html Edit: that email from ESR cites a talk from an LLVM developer which goes into more detail about this argument and about a lot of the architectural differences between GCC and LLVM: https://www.youtube.com/watch?v=lqN15lrADlE https://www.youtube.com/watch?v=lqN15lrADlE. I'm not sure how up-to-date this is though, as it looks like it was recorded in 2012. At least in the Apple ecosystem, the results of LLVM certainly spoke for themselves. Immediately after hiring Chris Lattner and adopting LLVM, Apple's developer experience began to improve massively in a very short time, coming out with automatic reference counting, Objective-C 2.0, the Clang static analyzer, live syntax checking and vastly improved code completion, bitcode, Metal shaders, and Swift within just a few years. Of course, I don't know how much of this was due to technical reasons rather than legal reasons (but Apple did make most of this work open-source).
- gumby 6y ago
  While RMS is opposed to such a thing there is no architectural reason for it not to happen, just little to no support for anything not GPLed. ESR has no idea what he is talking about. It is true that GCC's architecture dates to the 80s and so isn't modular in the same way LLVM is, but that is hardly due to some sort of policy-embodied-in-code. As well, RMS no longer controls gcc, and has not since the late 90s when I engineered a fork of gcc from the FSF and into the hands of an independent steering committee. At the time such an idea was radical...thankfully it is now commonplace.
  - NobodyNada 6y ago
    Thank you for the clarifications, this is really quite interesting. Compiler development is fascinating, and I love these sorts of threads because I always learn something new about the technology/culture/history.
magicalhippo 6y ago
> AFAIK the GPL isn't really relevant unless you're modifying and redistributing GCC itself. A lot of interesting LLVM use-cases are all about that, adding custom frontends or backends used in software that is distributed. Some random examples: https://www.elementscompiler.com/elements/island/ https://www.elementscompiler.com/elements/island/ https://ispc.github.io/ https://ispc.github.io/ https://www.khronos.org/spir/ https://www.khronos.org/spir/
- pjmlp 6y ago
  Just like GCC has had Cobol, Ada, Fortran, Modula-2, Pascal, Java, Go and plenty of other ones throughout the years.
  - magicalhippo 6y ago
    And how many of those were/are commercial or similar? The point is that GCC requires you to adhere to the GPL, which may not be desirable. The Island platform that I linked to is one such commercial example, made and sold by RemObjects[1]. OpenCL support in graphics drivers is another example. [1]: https://www.remobjects.com/ https://www.remobjects.com/
    - pjmlp 6y ago
      GNATPro is commercial, which is GNAT plus some extra stuff and commercial support from AdaCore. Modula-3 frontend was commercial, by Elego Software Solutions. Then naturally Objective-C and Objective-C++ frontends used on NeXTSTEP and OpenSTEP.
    - the_why_of_y 6y ago
      GCC's C, C++ and Fortran frontends are commercial products of at least Red Hat and SuSE, for example see https://developers.redhat.com/products/developertoolset/overview https://developers.redhat.com/products/developertoolset/over... and https://suse.com/c/suse-linux-essentials-where-are-the-compilers-understanding-the-development-tools-module/ https://suse.com/c/suse-linux-essentials-where-are-the-compi... GCC's Go frontend is still commercially supported as part of RHEL7 but was replaced by the more popular Go implementation in later versions. GCC's Java frontend used to be commercially supported in the days before OpenJDK.
bluGill 6y ago
Distributuon is a common use case. Not as much for a compiler, but for other things. My company spends a lot of time (money) ensuring we can ship the right source code when asked even though paying us $5 for it is silly when you can get it from the internet for free. I'd say nobody has ever asked, but that isn't true. One person in the test group actually read the entire eula and sent us $5 to get the source code. (I found out when his letter was returned to sender - we officially went through the entire release process just to fix the address at great expense. Even though it was still internal not released legal demanded we show good faith in correcting the problem) testers like that are worth far more than anyone pays them.

saagarjha 6y ago

Because Apple modifies and distributes LLVM in their proprietary developer tools.

redwatch 6y ago

It is somewhat easy to work and modify llvm tools: an optimization pass for instance. Also, LLVM tools were designed to be interchangeable. One can pick specific parts of LLVM and integrate into the workflow of others.

redis_mlc 6y ago

Because Apple is intensely allergic to the GPL. The reasons are: - As somebody else mentioned, Apple redistributes developer tools, clang being the poster child - Since they releases OS products, they don't want to co-mingle their software with GPL code. (So they use an older bash on Mac OS X.) - fear of an Apple developer quietly copying GPL source into a commercial product (well-founded, actually) - Apple Legal exerting an "abundance of caution" on IP - at this point, it's institutional. When I worked there, Linux and MySQL were forbidden, for example, but that has relaxed recently. Also, I think you misunderstand the GPL. If you distribute modified gcc, anybody receiving it can ask for sources. So employees plus end-users. (One of the strangest examples is that Yamaha uses real-time linux in their synths, and you can download the GPL portions. I can't imagine a musician ever wanting to do that!) Source: ex-Apple.

sjwright 6y ago
> Apple is intensely allergic to the GPL. Their actual marketplace behaviour demonstrates that they're allergic to GPL version 3 specifically, not the GPL or copyleft in general.
- stephen_g 6y ago
  Which I think is reasonable - I do think GNU went too far with the version 3 licenses. I think Rob Landley's perspective is interesting, where he was involved with Busybox and the legal action against companies violating the GPL with that software, but later created an alternative to Buysbox that was more permissively licensed because he felt that the whole GPL legal action exercise had been counter-productive for open source software in general (net effect of not encouraging many companies to contribute back but instead just making many companies avoid GPL-licensed software altogether).
- saagarjha 6y ago
  They’re fairly allergic to copyleft these days; I can’t recall them adopting a new project with any version of GPL for quite a while.
  - sjwright 6y ago
    There aren't so many GPL 2.0–only projects out there to adopt.
pcwalton 6y ago
> (So they use an older bash on Mac OS X.) Presumably you mean that Apple specifically avoids GPL3 then, because bash was never distributed under anything other than the GPL to my knowledge. Bash moved from GPL2 to GPL3 though.
- jabl 6y ago
  They've been on a general GPL purge rampage, in each macOS release there's less and less GPL software (there was some blog post with numbers). As for bash, in the latest release the default shell is zsh, though I think the old bash is still there, although clearly on the way out.
alerighi 6y ago
Isn't Apple clang open source anyway? So what is really the point? Even distribuiting GPL software isn't a big deal, nowadays even Microsoft does that, shipping an entire Linux distribution in Windows! There are no technical motivations for not using GPL software, you can do that as long you respect the GPL license (i.e. release the modified source code). I think that what Apple does is more a policy to go against the FOSS community for political reasons that anything else, and to me is bad, in a world where now even Microsoft is opening up a lot to the open source world.
- throwaway09922 6y ago
  [Ex FAANG here] > I think that what Apple does is more a policy to go against the FOSS community for political reasons that anything else This is the real reason why FAANGs push for non-GPL licenses. GPL's end goal is to build a community where developers, testers, power users and regular users connect with each other and share knowledge, not just code. FAANGs want to wedge themselves as the middleman between developers and end users. They view such community as a threat.
  - andrekandre 6y ago
    > FAANGs want to wedge themselves as the middleman between developers and end users. well... ostensibly that is where the money can be made (at the point they meet the end-user)
- belorn 6y ago
  > Isn't Apple clang open source anyway? So what is really the point? The best explanation I have seen is the speculation that apples software patents are seen as a critical part of apples business model and competitive strategy, especially 10 years ago when their anti-gpl stance was formed. GPLv3 patent clause adds risk, especially the patent agreement clause, and if you intend to spend millions over software patent lawsuits then staying away from GPLv3 looks much more reasonable, especially if you ask the patent lawyers.
tobias3 6y ago
Specifically GPLv3. One reason, I think, is the tivoization clause. Users must be able to modify GPLv3 software and then run the modified version. If they included a GPLv3 bash into iOS, iOS users must be able to modify bash and use the modified one instead. Your synth example is a good one actually. As a synth owner, I'd probably love to be able to replace the software on it with modified versions from the Internet or modify it myself. Linux is GPLv2, though. How that morphed into disallowing GCC, idk. Maybe they want to prohibit users from installing their own compilers at some point? Others have mentioned the patent clause. That one seems reasonable as well. In fact LLVM uses the Apache 2.0 license which also has a patent grant, albeit with a smaller scope. Apple could probably file a patent for a feature, then get a university department to implement that feature, then sue other LLVM users (like Sony). With the GPLv3 that loophole does not exist.
jart 6y ago
Apple's only overreacting due to deal Jobs made in the late 90's.

kevin_thibedeau 6y ago

You don't technically have to disclose internal mods to all employees because everyone is part of a single legal entity and no binary distribution occurs.

marcoperaza 6y ago
Perhaps but then you will kick yourself the first time you want to give a customer or business partner access to your modifications. Unforeseen business needs or opportunities can always make you need to distribute a tool you previously thought would only be internal. I'm not saying this is a slam-dunk reason to not use GPL tools, but I'm just pointing out that there is a legitimate worry here that is not fully alleviated by your point.
- deleted 6y ago
  [deleted]

NobodyNada 6y ago

One argument I've heard before is that GCC's architecture is intentionally designed to make it difficult to extend GCC or integrate it into other tools such as IDEs, because that sort of modularlization could enable interoperability with non-GPL software. I'm not sure whether this argument has any merit, but see e.g. this email from ESR: https://gcc.gnu.org/legacy-ml/gcc/2014-01/msg00209.html https://gcc.gnu.org/legacy-ml/gcc/2014-01/msg00209.html Edit: that email from ESR cites a talk from an LLVM developer which goes into more detail about this argument and about a lot of the architectural differences between GCC and LLVM: https://www.youtube.com/watch?v=lqN15lrADlE https://www.youtube.com/watch?v=lqN15lrADlE. I'm not sure how up-to-date this is though, as it looks like it was recorded in 2012. At least in the Apple ecosystem, the results of LLVM certainly spoke for themselves. Immediately after hiring Chris Lattner and adopting LLVM, Apple's developer experience began to improve massively in a very short time, coming out with automatic reference counting, Objective-C 2.0, the Clang static analyzer, live syntax checking and vastly improved code completion, bitcode, Metal shaders, and Swift within just a few years. Of course, I don't know how much of this was due to technical reasons rather than legal reasons (but Apple did make most of this work open-source).

gumby 6y ago
While RMS is opposed to such a thing there is no architectural reason for it not to happen, just little to no support for anything not GPLed. ESR has no idea what he is talking about. It is true that GCC's architecture dates to the 80s and so isn't modular in the same way LLVM is, but that is hardly due to some sort of policy-embodied-in-code. As well, RMS no longer controls gcc, and has not since the late 90s when I engineered a fork of gcc from the FSF and into the hands of an independent steering committee. At the time such an idea was radical...thankfully it is now commonplace.
- NobodyNada 6y ago
  Thank you for the clarifications, this is really quite interesting. Compiler development is fascinating, and I love these sorts of threads because I always learn something new about the technology/culture/history.

magicalhippo 6y ago

> AFAIK the GPL isn't really relevant unless you're modifying and redistributing GCC itself. A lot of interesting LLVM use-cases are all about that, adding custom frontends or backends used in software that is distributed. Some random examples: https://www.elementscompiler.com/elements/island/ https://www.elementscompiler.com/elements/island/ https://ispc.github.io/ https://ispc.github.io/ https://www.khronos.org/spir/ https://www.khronos.org/spir/

pjmlp 6y ago
Just like GCC has had Cobol, Ada, Fortran, Modula-2, Pascal, Java, Go and plenty of other ones throughout the years.
- magicalhippo 6y ago
  And how many of those were/are commercial or similar? The point is that GCC requires you to adhere to the GPL, which may not be desirable. The Island platform that I linked to is one such commercial example, made and sold by RemObjects[1]. OpenCL support in graphics drivers is another example. [1]: https://www.remobjects.com/ https://www.remobjects.com/
  - pjmlp 6y ago
    GNATPro is commercial, which is GNAT plus some extra stuff and commercial support from AdaCore. Modula-3 frontend was commercial, by Elego Software Solutions. Then naturally Objective-C and Objective-C++ frontends used on NeXTSTEP and OpenSTEP.
  - the_why_of_y 6y ago
    GCC's C, C++ and Fortran frontends are commercial products of at least Red Hat and SuSE, for example see https://developers.redhat.com/products/developertoolset/overview https://developers.redhat.com/products/developertoolset/over... and https://suse.com/c/suse-linux-essentials-where-are-the-compilers-understanding-the-development-tools-module/ https://suse.com/c/suse-linux-essentials-where-are-the-compi... GCC's Go frontend is still commercially supported as part of RHEL7 but was replaced by the more popular Go implementation in later versions. GCC's Java frontend used to be commercially supported in the days before OpenJDK.

bluGill 6y ago

Distributuon is a common use case. Not as much for a compiler, but for other things. My company spends a lot of time (money) ensuring we can ship the right source code when asked even though paying us $5 for it is silly when you can get it from the internet for free. I'd say nobody has ever asked, but that isn't true. One person in the test group actually read the entire eula and sent us $5 to get the source code. (I found out when his letter was returned to sender - we officially went through the entire release process just to fix the address at great expense. Even though it was still internal not released legal demanded we show good faith in correcting the problem) testers like that are worth far more than anyone pays them.