Apple will "take at least several months" to release LLVM backend for 64-bit A7

Have you read past the first sentence?

We already have a copyleft compiler, GCC, and under the stewardship of the FSF it has turned into a total mess. The community has been wasting effort for years duplicating issues that have already been solved in GCC because the FSF refused to merge patches that would make it modular. On the other hand, you can download Clang and make your own tools from it now. Go ahead, I dare you to do either of the following:

* Use GCC's C frontend to write a code analysis tool of any sort,

* Write a new frontend to GCC.

FSF's damage to the GCC code base proved that you can still sabotage freedom while adhering to the letter of a copyleft license.

I suspect the KHTML mess is still fresh in the minds of many engineers at Apple.

> If LLVM were under a copyleft license like the GPL, ...

You say that as if making such a dramatic license change would affect nothing else besides the rate at which changes made by companies get released to the wild. That's preposterous. If LLVM were GPL'd then Apple would not be using it. Full stop.

The whole reason Apple started heavily backing LLVM and built clang is because of gcc's license. Do not think for a moment that LLVM being GPLd means Apple would be releasing this code now. Instead, it means Apple would never release this code, because it would be part of some internal compiler project they probably would not feel like making open source at all.

At this point, LLVM and clang largely are Apple. This complaining about the timeline of the open source release of their own work is a bit nuts.

Well feel free to release your compiler under whichever license you want.

The LLVM people released theirs under a BSD style license precisely so that people and companies could do things like this

If "the community" wastes their time solving ARM 64-bit problems it's their own fault for not waiting for Apple's code.

"In the mean-time, the community will be wasting time and effort in trying to solve ARM 64-bit issues which Apple has already solved."

Yep, Release them as early as possible so Samsung could copy and sit there does nothing? And Solving 64bit issues of what? The whole thing surprise the industry because Absolutely NO one was expecting an ARMv8 64bit chip on market until late 2014!

[1] Apple try to open it as standard, and they got sued by Patents Trolls. And are still battling it in court.

> I'm reading this over and over and still not understanding how withholding source code is "the right thing" and worthy of praise

Because the other option is to do a code-dump of their customized code, making it nearly impossible to merge back into the main trunk. They've done that before, and gotten bitched out about it (and rightfully so). Doing it this way shows that their goal is to move the project forward by adding their new contributions, not merely fulfilling their legal obligation to "get it out there", regardless of whether the main project gets any benefit.

The "right thing" is merging it back into LLVM instead of hoarding it in their private repository.

Apple, like many proprietary companies, don't use the public repository for any working branches, so a meticulous and time-consuming merge back into the trunk (which will have changed on its own in the meantime) is required.

Additionally, since large companies like Apple tend to be magnets for lawsuits, everything the company publishes (even in open-source code repositories) may need to be reviewed by lawyers (or at least more senior engineers) to make sure there's no plagiarism, accidental inclusion of privately licensed code or leaking of confidential information.

> Either it's an open source toolchain or it's not.

LLVM is an open source toolchain. Not every project built on LLVM is an open source toolchain. For copyleft ideologues this is a problem. Not everyone is a copyleft ideologue.

Yes, dumping a huge diff of all the changes they've made to their internal LLVM project today would definitely be the right thing to do; I'd guess it's on the order of at least hundreds of thousands of lines of code. What Apple are doing here is making sure it can be cleanly added to where LLVM has got to outside Apple, and not just saying "hey, you want our code? Well here it is, you try and make it work!" Yes this takes longer, but, as they say, it's the right way to do things with an open source project used commercially.

It seems obvious that they kept it secret because if Apple had been pushing out improvements to the ARM64 code generator for the past months, someone would have connected the dots and understood they were building an ARM64 device.

All Chris Lattner's message is saying is that Apple's contributions here are subject to the same process as anyone else, namely incremental commits with community review.