I am working on a port of LLVM targeting a proprietary VM. Thus far
development has been under Linux and Cygwin. Cygwin licensing would appear
to require that LLVM built under Cygwin would have to be released under the
GPL, so alternatives are being investigated.
I am not a lawyer, but:
I think that you are misinterpreting the GPL.
Just because Cygwin contains some GPL software
does not automatically make all software it
compiles GPL. Compiling LLVM with Cygwin
does not change Cygwin's license.
So, you are safe here.
(The only way the GPL would apply is if you
were modifying Cygwin itself here, which you are not.
You are just using it to compile something else.)
Unfortunately, I believe the issue is not that Cygwin contains GPL code, it
is that applications which it compiles do. This is explicitly stated at http://cygwin.com/licensing.html:
"The Cygwin API library found in the winsup subdirectory of the source code
is also covered by the GNU GPL (with exceptions; see below). By default, all
executables link against this library (and in the process include GPL'd
Cygwin glue code). This means that unless you modify the tools so that
compiled executables do not make use of the Cygwin library, your compiled
programs will also have to be free software distributed under the GPL with
source code available to all."
The exceptions mentioned are for applications which are themselves Open
Source. But, by their definition, I do not believe LLVM is considered Open
Source, because it allows someone to modify it and distribute the binaries
without the modified sources.
Unfortunately, I believe the issue is not that Cygwin contains GPL code, it
is that applications which it compiles do. This is explicitly stated at http://cygwin.com/licensing.html:
If you have serious questions about the licensing of Cygwin/LLVM, you
really need to talk to a lawyer. No one on this list can give you
advice in that area which will accurately reflect what is correct for
you and your needs because none of us are lawyers.
Perhaps you should explore the possibilities of VC, etc., which are
actively maintained by members of the community. If you have specific
questions about getting up and started with these, let us know.
For your previous questions:
1) "svn" is a Subversion command (see http://subversion.tigris.org/).
Subversion is the versioning system we use here.
2) There are "make" commands out there for Windows. But if you're
having troubles with them, ask if there are other ways to get around
it...
Many thanks. Yes, this question has slightly sidetracked on the license
issue, which was mostly an aside as to why we wish to use something other
than Cygwin.
On the make issue, I am very interested to know what it is supposed to be
doing. Is this a standard Linux-like make, and if so where is the Makefile
which defines the "checkout" target?
Many thanks. Yes, this question has slightly sidetracked on the license
issue, which was mostly an aside as to why we wish to use something other
than Cygwin.
I totally understand. I just wanted to bring it back on a technical track.
On the make issue, I am very interested to know what it is supposed to be
doing. Is this a standard Linux-like make, and if so where is the Makefile
which defines the "checkout" target?
It's not a standard target. You probably don't need to use "svn" or
the "make" command. Just follow the directions in the "With the
distributed file" section.
I just wanted to bring it back on a technical track.