llvm dev - Sep 2016 - RFC #2: Improving license & patent issues in the LLVM community

On Sep 12, 2016, at 10:10 AM, Ed Schouten <ed at nuxi.nl>
wrote:
>> 
>> ---- end ---
> 
> Just to make sure I get this straight, I can substitute 'this
> Software' by the names of components provided by the LLVM project.
This is the literal license text that will be included with each of these
projects, so no, you cannot literally make that substitution.

However, yes, this will cover all parts of the LLVM project including LLVM,
Clang, LLDB, libc++ etc if that’s what you’re asking.
> For
> example:
> 
>> As an exception, if you use LLVM, Clang and/or DragonEgg to compile
your source code and portions of compiler-rt, libc++, libc++abi and/or libunwind
are embedded into the binary product as a result, you may redistribute such
product without providing attribution as would otherwise be required by Sections
4(a), 4(b) and 4(d) of the License.
The license specifically does not make a distinction between LLVM/clang and
libc++/compiler-rt.  You should be able to embed LLVM or clang code into a
binary without having to provide attribution.

> I've got a couple of questions about this.
> 
> - Now that we're also in the business of providing other kinds of
> tools that are not compilers (e.g., LLD being a linker), are we sure
> that this will cover all of our needs?
Yes, I don’t see anything functionally or use-case different between LLD and
Clang or LLDB.
> - What about derived software?
You need to specify what you mean by derived, I’ll answer the specific questions
below to the best of my knowledge.  However, it would be great for someone like
DannyB to confirm this.
> Would this also apply if I'd be using
> the Swift compiler to generate an executable that contains some bits
> from compiler-rt?
Yes, the runtime exception clause covers the code being embedded (compiler-rt)
not relating to how it got embedded.

FWIW, Swift already uses the Apache 2 license with the runtime exception clause,
but that isn’t important for the question.
> What if I'd be using GCC, but added a tiny fraction
> of LLVM's source code to it? What about a stock version of GCC that is
> linked against compiler-rt?
Both are fine, the compiler-rt code is covered regardless of how it gets
embedded.  You could use a fully proprietary compiler like Intel’s ICC and that
would also be fine.
> Sorry if some of these questions may seem hypothetical or silly; I'm
> merely interested in knowing where the boundary is and how this
> licensing exception will work in practice.
No problem at all,

-Chris

>
> > - What about derived software?
>
> You need to specify what you mean by derived, I’ll answer the specific
> questions below to the best of my knowledge.  However, it would be great
> for someone like DannyB to confirm this.
>
>
Happy to try to give you specific answers if you have specific questions
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Hi Chris,

2016-09-12 19:58 GMT+02:00 Chris Lattner <clattner at
llvm.org>:
> You could use a fully proprietary compiler like Intel’s ICC and that would
also be fine.
Got it. That's good to hear. What got me on the wrong track is the
following:
> As an exception, if you use this Software to compile your source code [...]
I interpreted this as if 'this Software' has an active role, namely
that it has to be the compiler itself. If I read your response
correctly, this doesn't need to be the case. Any piece of software can
be used for that purpose. It would have been a lot more clear for me
if it said:
> As an exception, if this Software is compiled and/or linked together with
your source code [...]
But I am not a laywer. :-)

-- 
Ed Schouten <ed at nuxi.nl>
Nuxi, 's-Hertogenbosch, the Netherlands
KvK-nr.: 62051717

> On Sep 12, 2016, at 1:09 PM, Ed Schouten <ed at nuxi.nl> wrote:
> 
> Hi Chris,
> 
> 2016-09-12 19:58 GMT+02:00 Chris Lattner <clattner at llvm.org>:
>> You could use a fully proprietary compiler like Intel’s ICC and that
would also be fine.
> 
> Got it. That's good to hear. What got me on the wrong track is the
following:
> 
>> As an exception, if you use this Software to compile your source code
[...]
> 
> I interpreted this as if 'this Software' has an active role, namely
> that it has to be the compiler itself. If I read your response
> correctly, this doesn't need to be the case. Any piece of software can
> be used for that purpose. It would have been a lot more clear for me
> if it said:
> 
>> As an exception, if this Software is compiled and/or linked together
with your source code [...]
> 
> But I am not a laywer. :-)

Ah, I see what you’re saying.  Let me chat with a few folks and get back to you,
thank you for pointing this out!

-Chris