[RFA] Some libgcc headers are missing the runtime exception

[Richard Sandiford]

David Edelsohn <dje.gcc@gmail.com> writes:
> On Mon, Jul 12, 2021 at 11:58 AM Richard Sandiford
> <richard.sandiford@arm.com> wrote:
>>
>> David Edelsohn <dje.gcc@gmail.com> writes:
>> > On Fri, Jul 9, 2021 at 1:31 PM Richard Sandiford
>> > <richard.sandiford@arm.com> wrote:
>> >>
>> >> David Edelsohn <dje.gcc@gmail.com> writes:
>> >> > On Fri, Jul 9, 2021 at 12:53 PM Richard Sandiford via Gcc
>> >> > <gcc@gcc.gnu.org> wrote:
>> >> >>
>> >> >> Hi,
>> >> >>
>> >> >> It was pointed out to me off-list that config/aarch64/value-unwind.h
>> >> >> is missing the runtime exception.  It looks like a few other files
>> >> >> are too; a fuller list is:
>> >> >>
>> >> >> libgcc/config/aarch64/value-unwind.h
>> >> >> libgcc/config/frv/frv-abi.h
>> >> >> libgcc/config/i386/value-unwind.h
>> >> >> libgcc/config/pa/pa64-hpux-lib.h
>> >> >>
>> >> >> Certainly for the aarch64 file this was simply a mistake;
>> >> >> it seems to have been copied from the i386 version, both of which
>> >> >> reference the runtime exception but don't actually include it.
>> >> >>
>> >> >> What's the procedure for fixing this?  Can we treat it as a textual
>> >> >> error or do the files need to be formally relicensed?
>> >> >
>> >> > I'm unsure what you mean by "formally relicensed".
>> >>
>> >> It seemed like there were two possibilities: the licence of the files
>> >> is actually GPL + exception despite what the text says (the textual
>> >> error case), or the licence of the files is plain GPL because the text
>> >> has said so since the introduction of the files.  In the latter case
>> >> I'd have imagined that someone would need to relicense the code so
>> >> that it is GPL + exception.
>> >>
>> >> > It generally is considered a textual omission.  The runtime library
>> >> > components of GCC are intended to be licensed under the runtime
>> >> > exception, which was granted and approved at the time of introduction.
>> >>
>> >> OK, thanks.  So would a patch to fix at least the i386 and aarch64 header
>> >> files be acceptable?  (I'm happy to fix the other two as well if that's
>> >> definitely the right thing to do.  It's just that there's more history
>> >> involved there…)
>> >
>> > Please correct the text in the files. The files in libgcc used in the
>> > GCC runtime are intended to be licensed with the runtime exception and
>> > GCC previously was granted approval for that licensing and purpose.
>> >
>> > As you are asking the question, I sincerely doubt that ARM and Cavium
>> > intended to apply a license without the exception to those files.  And
>> > similarly for Intel and FRV.
>>
>> FTR, I think only Linaro (rather than Arm) touched the aarch64 file.
>>
>> > The runtime exception explicitly was intended for this purpose and
>> > usage at the time that GCC received approval to apply the exception.
>>
>> Ack.  Is the patch below OK for trunk and branches?
>
> I'm not certain whom you are asking for approval,

I was assuming it would need a global reviewer.

> but it looks good to me.

Thanks.

> It would be nice to add SPDX License Identifier at the top of the
> files as well, but that's not required.

Yeah, I agree that might a good thing to have, but TBH I try to keep
my involvement with licensing stuff to the bare minimum :-)

Richard