Re: [Xen-devel] coverage license information

[Ian Lance Taylor <iant@xxxxxxxxxx>]

On Mon, Feb 4, 2013 at 6:54 AM, Frediano Ziglio
<frediano.ziglio@xxxxxxxxxx> wrote:
>
> I imported some headers from Linux kernel which mainly came from
> gcov-io.h and the structures used internally by GCC.
>
> Our problem is currently about the license. In gcov-io.h is stated that
> license is mainly GPL2 which the exception that linking the "library"
> with other files does not cause these files to be GPL2. Now however I'm
> not linking to any library but just using the structure declaration
> inside the header to produce a blob that is currently converted into GCC
> files by an external utility (Xen has not file system so we extract
> coverage information).
>
> It's not a problem to use these headers/structure from Xen (which is
> GPL2) but we'd like to have these defines in our public include headers.
> The license however of these headers is quite open and allow to be used
> for instance in commercial programs. How the license would affect these
> programs?
>
> Another question we have is the stability of these structures. Can we
> just check the version field of gcov_info to make sure that the internal
> structure is not changed or is it expected that even this field would
> change (for instance position or size inside the structure) ?

You neglected to say which version of GCC you are using.  In current
GCC the header file gcov-io.h is under GPLv3 with the GCC Runtime
Library Exception 3.1
(http://www.gnu.org/licenses/gcc-exception-3.1.html).

I don't fully grasp the situation in which a user of xen would want to
#include this header file.  But if a program does #include the header
file, then in the strictest possible reading that program would be
covered by GPLv3 plus the GCC Runtime Library Exception.  That would
impose certain requirements on the program, basically that if it is
compiled by a version of GCC with a proprietary extension, the program
may not be distributed in binary form.  Those requirements already
apply to essentially any program compiled by a current version of GCC.
 Inciuding the header file gcov-io.h should not add any additional
requirements.

Hope this helps.  This is of course not legal advice, but you are
unlikely to get good legal advice in this area.

Ian

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel