LGPL Requirements (was: Selecting Ada95 compiler for MSDOS realtime application)
F. Britt Snodgrass
Samuel Tardieu <s...@hacker.org> wrote:
>>>>>> "Richard" == Richard Maffei <rama...@cedar-rapids.net> writes:
>
>Richard> A non-GNAT solution is preferred to avoid any potential
>Richard> restrictions/requirements associated with the commercial
>Richard> release of software containing GNU libraries.
>
>Richard,
>
>I really cannot understand this sentence: the GNU licence does concern
>you *only* if you want to redistribute a modified *compiler*, that is
>if your project is to produce and give away (sell ?) an Ada compiler
>(which I guess isn't, since you mention real-time) and choose to
>modify GNAT, then you have to distribute the sources as well and
>respect the licence.
>
>But if you use GNAT for development as a compiler, then it doesn't add
>any restriction or requirement compared to other compilers! I think
>you should take some time and read the General Public Licence which is
>distributed with GNAT.
>
>I know of several companies that use GNAT for developping commercial
>applications and sell these applications without any restriction.
>
> Sam, happy user of GNAT
>--
> Samuel Tardieu -- s...@hacker.org
Perhaps Richard's comment was made precisely because he has read the
GNU Library General Public License (LGPL) that covers GNAT's libraries.
The LGPL makes no distinction between compilers and any other type of
executable program that has LGPL'd libraries linked in. I assume that
the bodies of GNAT's standard Ada packages contain such library code.
As I read it, the LGPL says I have to either (1) provide all my object
code to my customers so that they may relink my program with a
newer/modified version of the LGPL'd libraries or (2) explictly allow
them to reverse engineer my program for the purpose of modifying it.
The complete LGPL is in the copying.lib file distributed with GNAT
or may be obtained from http://www.delorie.com/dl/prep/COPYING-LIB-2.0.
For reference, I quote Section 6 here:
LGPL> "6. As an exception to the Sections above, you may also compile or
LGPL> link a "work that uses the Library" with the Library to produce a
LGPL> work containing portions of the Library, and distribute that work
LGPL> under terms of your choice, provided that the terms permit
LGPL> modification of the work for the customer's own use and reverse
LGPL> engineering for debugging such modifications.
LGPL>
LGPL> You must give prominent notice with each copy of the work that the
LGPL> Library is used in it and that the Library and its use are covered by
LGPL> this License. You must supply a copy of this License. If the work
LGPL> during execution displays copyright notices, you must include the
LGPL> copyright notice for the Library among them, as well as a reference
LGPL> directing the user to the copy of this License. Also, you must do one
LGPL> of these things:
LGPL>
LGPL> a) Accompany the work with the complete corresponding
LGPL> machine-readable source code for the Library including whatever
LGPL> changes were used in the work (which must be distributed under
LGPL> Sections 1 and 2 aboveArticle Unavailable
Samuel Tardieu
>>>>> "F" == F Britt Snodgrass <ad...@fyiowa.infi.net> writes:
F> Perhaps Richard's comment was made precisely because he has read
F> the GNU Library General Public License (LGPL) that covers GNAT's
F> libraries.
GNAT's libraries covered by the LGPL ? Where did you read this ?
F> I would be happy to have someone convince me I'm reading too much
F> into the LGPL but it seems pretty clear to me. As much as I like
F> GNAT, using it to develop embedded software for a non-free
F> commercial product seems to levy additional requirements compared
F> to using a non-free Ada compiler. Am I wrong?
Well, let's take a GNAT library file: Ada.Text_IO (body) for
example. The copyright that is written in it reads:
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
Note the "As a special exception ..." paragraph ! Also note that the
LGPL isn't mentionned anywhere in this notice !
Sam
--
Samuel Tardieu -- s...@ada.eu.org
Dale Pontius
In article <55rs5t$2...@nw101.infi.net>,
"F. Britt Snodgrass" <ad...@fyiowa.infi.net> writes:
>...
>Perhaps Richard's comment was made precisely because he has read the
>GNU Library General Public License (LGPL) that covers GNAT's libraries.
>The LGPL makes no distinction between compilers and any other type of
>executable program that has LGPL'd libraries linked in. I assume that
>the bodies of GNAT's standard Ada packages contain such library code.
>As I read it, the LGPL says I have to either (1) provide all my object
>code to my customers so that they may relink my program with a
>newer/modified version of the LGPL'd libraries or (2) explictly allow
>them to reverse engineer my program for the purpose of modifying it.
>Now if it is my business to write embedded software for video games machines
>and/or nuclear reactor control systems, I could reasonably view the LGPL
>requirements as both an annoyance and as a product safety risk. While I
>understand and appreciate the spirit of free software, I may not want my
>customers to have the ability to reverse engineer and modify software embedded
>in the products I sell.
>
>I would be happy to have someone convince me I'm reading too much into the LGPL
>but it seems pretty clear to me. As much as I like GNAT, using it to develop
>embedded software for a non-free commercial product seems to levy additional
>requirements compared to using a non-free Ada compiler. Am I wrong?
>
Would this be solved if dynamic linking were used? The GNAT runtime
could be kept in a completely separate file which could be replaced
at will without touching your code. That way there would be no need
to reverse engineer your code.
In practice this would end up looking like DOS4GW programs. The main
program becomes DOS4GW.EXE, and it dynamically loads and executes your
program. Otherwise you would need to have the dynamic loading part of
GNAT embedded in your code, and the same problems come back. If you're
concerned about 'one file', use binary concatenation. The GNAT loader/
library program looks 'after itself' to find the start of your code.
You could supply a simple strip/combine utility and you're done.
Dale Pontius
(NOT speaking for IBM)
Robert Dewar
Dale Pontius says
"Would this be solved if dynamic linking were used? The GNAT runtime
could be kept in a completely separate file which could be replaced
at will without touching your code. That way there would be no need
to reverse engineer your code."
No, this would not solve anything, but then as I trust previous posts
have made clear there was no problem that needed a solution in the
first place!
Robert Dewar
F. Britt Snodgrass says
>Perhaps Richard's comment was made precisely because he has read the
>GNU Library General Public License (LGPL) that covers GNAT's libraries.
This is confused, that is not the way GNAT's libraries are distributed.
It always amazes me that people run off on such irrelevant arguments without
even bothering to look!
>The LGPL makes no distinction between compilers and any other type of
All discussion of the LGPL is irrelevant to GNAT!
>I would be happy to have someone convince me I'm reading too much into
>the LGPL but it seems pretty clear to me. As much as I like GNAT, using
>it to develop embedded software for a non-free commercial product seems
>to levy additional requirements compared to using a non-free Ada compiler.
>Am I wrong?
Yes, completely wrong. You are in fact also misreading the LGPL, but
since it is irrelevant to GNAT, there is no point in persuing it.
For reference, here is the license used on GNAT runtime components:
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
As you can see from this there are no additional requirements compared to
using a non-free Ada compiler. You can build proprietary products, embedded
gizmos, or classified software using GNAT with no problems whatsoever in
this department.
A lot of people have an interest in spreading FUD on this point, so let's
try to keep things clear here. In particular, please READ the licenses that
apply, not ones that don't!
F. Britt Snodgrass
de...@merv.cs.nyu.edu (Robert Dewar) wrote:
>
> [snip]
>
> All discussion of the LGPL is irrelevant to GNAT!
>
>-- --
>-- As a special exception, if other files instantiate generics from this --
>-- unit, or you link this unit with other files to produce an executable, --
>-- this unit does not by itself cause the resulting executable to be --
>-- covered by the GNU General Public License. This exception does not --
>-- however invalidate any other reasons why the executable file might be --
>-- covered by the GNU Public License. --
>
>As you can see from this there are no additional requirements compared to
>using a non-free Ada compiler. You can build proprietary products, embedded
>gizmos, or classified software using GNAT with no problems whatsoever in
>this department.
>
>A lot of people have an interest in spreading FUD on this point, so let's
>try to keep things clear here. In particular, please READ the licenses that
>apply, not ones that don't!
>
Thank you and others who have corrected my misunderstanding
of GNAT's license. I had assumed that since the file "copying.lib"
is distributed with GNAT, it's requirements must apply to GNAT's
libraries. I did not think to look at the file headers because I
wasn't aware that "special exceptions" to the GPL were permitted.
I work for a large corporation which currently discourages the use
of GNU software. The company lawyers have read the GPL and LGPL and
are nervous that we might unknowingly incorporate GPL'd software
into a product and then have customers requesting "our" software
under the terms of the GPL.
I am trying to get this no-GNU policy changed. I need to understand
how GNAT's GPL license may or may not differ from that of plain gcc
or g77. While I now understand that GNAT may be used to produce
propriatary,for-profit executables, the last sentence of the special
exception warns me to do so very carefully.
Thanks,
F. Britt Snodgrass (Team Ada, ad...@fyiowa.infi.net)
Jon S Anthony
> or g77. While I now understand that GNAT may be used to produce
> propriatary,for-profit executables, the last sentence of the special
> exception warns me to do so very carefully.
Not to worry. The last sentence merely means that if you are (would
be) already covered by GPL (say you decide to use the SA of GNAT for
some reason), and you include/link-in the library, the special
exception does not mean that you now free of GPL.
/Jon
--
Jon Anthony
Organon Motives, Inc.
Belmont, MA 02178
617.484.3383
j...@organon.com
Richard Kenner
>wasn't aware that "special exceptions" to the GPL were permitted.
How could they *not* be permitted? The GPL itself isn't being changed
here, it's just that the copyright is only including by reference
a different set of conditions than referencing the whole GPL would
produce.
>I work for a large corporation which currently discourages the use
>of GNU software. The company lawyers have read the GPL and LGPL and
>are nervous that we might unknowingly incorporate GPL'd software
>into a product and then have customers requesting "our" software
>under the terms of the GPL.
First of all, if you'd "unknowingly" incorporate GPL'ed software into
a product, I'd be concerned you also might unknowingly incorporate
some third-party licenced software into your product. Most companies
carefully track what software is part of their products, so I'm
confused why you don't.
Secondly, your lawyers might want to consider NeXT. This is a company
whose sole propriety asset is compiled using GPL'ed compilers and
linked with GPL'ed libraries.
>While I now understand that GNAT may be used to produce
>propriatary,for-profit executables, the last sentence of the special
>exception warns me to do so very carefully.
What are you talking about? What's your concern here?
All that sentence is saying is that if you have executable that would
be covered by the GPL by virtue of including a GPL'ed file, the mere
presence of that library file doesn't mean you can ignore that fact.
In other words, that fact that GNAT itself contains that file does not
mean that it no longer is covered by the GPL.
Vague concerns can't be dealt with. You and your company's lawyers needs
to come up with specific scenarios that you are concerned about. Then
discuss them with RMS or people on this group who will be happy to explain
why each of those scenarios can't happen.
Robert Dewar
Thank you and others who have corrected my misunderstanding
of GNAT's license. I had assumed that since the file "copying.lib"
is distributed with GNAT, it's requirements must apply to GNAT's
wasn't aware that "special exceptions" to the GPL were permitted.
Again, a huge misunderstanding of the GPL. Anyone holding a copyright
can license things however they please. For instance, someone could
use a license that allowed anyone but Microsoft to use a product free.
The GPL is simply a starting point that you can use or not as you
please, and modify anyway you like.
Now the FSF is interested in free availability, so for software copyrighted
by the FSF, it is unlikely that you would see peculiar restrictive versions
of the GPL. The idea of the special exceptions is to extend the utility
rather than to restrict it.
I work for a large corporation which currently discourages the use
of GNU software. The company lawyers have read the GPL and LGPL and
are nervous that we might unknowingly incorporate GPL'd software
into a product and then have customers requesting "our" software
under the terms of the GPL.
Well you can't blame the lawyers if you give them the wrong information.
They are right to worry about incorporating GPL'ed software and also, if
you don't want to distribute object files, you should also avoid including
anything that is copyrighted under the LGPL.
In general, you have to be very careful about incorporating components
into your software whose copyrights are held by others. This applies
equally to any copyrighted software. For example, if you use a TSP
compiler, then you are incorporating TSP copyrighted code into your
application, and you should have your lawyers make sure that this
does not cause you problems (I assume it does not, like ACT, TSP is
interested in avoiding such problems).
In the case of GNAT, you should also check carefully to make sure that
the copyrighted units you include do not cause you trouble, but please
give the right copyright statement to your lawyers, and not some
entirely irrelevant stuff!
I am trying to get this no-GNU policy changed. I need to understand
how GNAT's GPL license may or may not differ from that of plain gcc
or g77. While I now understand that GNAT may be used to produce
propriatary,for-profit executables, the last sentence of the special
exception warns me to do so very carefully.
No, you are not a lawyer probably, so you overreact to the last sentence.
All this says is that you can't go including units covered by the normal
GPL, and say "Hey, that's OK, I've got a unit here from GNAT that says
everything is OK".
I have occasionally run into cases where lawyers do not understand the issues
clearly, and indeed many people are confused and read all sorts of things into
the GPL that are not there (for example, the adahome page says that GPL'ed
software cannot be sold -- which is of course nonsense). However, in this
case, it seems that your lawyers were giving you correct information about
something that does not in fact apply to you.
Note that the runtime code for other GNU compilers (e.g. g++) is also
distributed under specialized versions of the GPL designed to eliminate
problems with incorporation of runtime library code. The statement for
GNAT is a specialized one, that specifically addresses the concern about
generic instantiation.
We are currently preparing a Web page that will attempt to clarify these
issues in further detail. Meanwhile, a useful example to think about is
NextStep. At this stage, the only property that this company has is its
proprietary operating system software. This is entirely written using
GCC. There are many other such examples.
I also note that we have run into a number of situations where sales people
from other Ada vendors have, shall we say, rather peculiar notions about
GNU software and the GPL, and work hard to pass these peculiar notions
on to their customers :-)
Robert Dewar
Robert White says
"All of the above still has me very confused. You need to make it
crystal clear to lawyers that there is not a problem. I do not think that
you and Robert Dewar have completely re-assured Richard, Britt and me that
there is not a problem. We need to get the lawyers to clear it."
It *is* quite clear to lawyers, but you need to give them the right
material to look at. Remember this thread started with an incorrect
uniformed guess that GNAT used the LGPL, and a comment that some lawyers
did not like the LGPL. The latter may be true, but given that GNAT does
NOT use the LGPL, not relevant
By all means have your lawyers read the GPL, and then read the exception
clause that is used in the license for GNAT components, as indeed you
should have them read ALL copyright and license provisions for ANY
components you intend to include in your software. If your lawyer
has a question, then, as Richard noted, have him get in touch with
RMS, or with us, and we will explain. In particular, if you or your
lawyer have some idea of a scenario which is worrisome, then explain
it to us, and we will explain to you why your worry is groundless.
We can't react to vague unarticulated concerns. Such concerns without
specific questions are indeed in the FUD category :-)
Lots of major companies, including Silicon Graphics, Lockheed, Boeing, and
many others are creating proprietary and/or classified Ada codes using
GNAT. Furthermore, in the past, many companies have used GNU C or G++
to create proprietary software. I gave the example of Nextstep, but there
are several other companies that use only GNU software to create their
proprietary software.
There is no problem here. Why you think there might be is unclear to us,
since you have not articulated any specific concern that can be addressed.
Robert S. White
In article <55v2eq$8...@news.nyu.edu>, ken...@lab.ultra.nyu.edu says...
...snip...
>>While I now understand that GNAT may be used to produce
>>propriatary,for-profit executables, the last sentence of the special
>>exception warns me to do so very carefully.
>
>What are you talking about? What's your concern here?
>
>All that sentence is saying is that if you have executable that would
>be covered by the GPL by virtue of including a GPL'ed file, the mere
>presence of that library file doesn't mean you can ignore that fact.
>In other words, that fact that GNAT itself contains that file does not
>mean that it no longer is covered by the GPL.
Huh? What file? So the GPL still applies?
>
>Vague concerns can't be dealt with. You and your company's lawyers needs
>to come up with specific scenarios that you are concerned about. Then
>discuss them with RMS or people on this group who will be happy to explain
>why each of those scenarios can't happen.
All of the above still has me very confused. You need to make it
crystal clear to lawyers that there is not a problem. I do not think that
you and Robert Dewar have completely re-assured Richard, Britt and me that
there is not a problem. We need to get the lawyers to clear it. We do not
want to spread FUD. We want to tell upper management that this is NOT
a barrier. In the meantime, other companies have a competitive advantage
over ACT for our business.
_______________________________________________________________________
Robert S. White -- an embedded sys software engineer
Whi...@CRPL.Cedar-Rapids.lib.IA.US --long/cheap alternate I-net address
Fergus Henderson
Whi...@CRPL.Cedar-Rapids.lib.IA.US (Robert S. White) writes:
]In article <55v2eq$8...@news.nyu.edu>, ken...@lab.ultra.nyu.edu says...
]>>While I now understand that GNAT may be used to produce
]>>propriatary,for-profit executables, the last sentence of the special
]>>exception warns me to do so very carefully.
]>
]>What are you talking about? What's your concern here?
]>
]>All that sentence is saying is that if you have executable that would
]>be covered by the GPL by virtue of including a GPL'ed file, the mere
]>presence of that library file doesn't mean you can ignore that fact.
]
]>In other words, that fact that GNAT itself contains that file does not
]>mean that it no longer is covered by the GPL.
]
] Huh? What file? So the GPL still applies?
Let me clarify:
All that sentence [the last sentence of the special exception
to the GLP in the copying conditions of a GNAT library file] is
saying is that if you have an executable that would be covered
by the GPL by virtue of including a GPL'ed file [some *other*
GPL'd file], the mere presence of that library file [the GNAT
library file] doesn't mean you can ignore that fact [the fact
that your executable is covered by the GPL, since it includes
that *other* GPL'd file].
For example, the fact that GNAT itself contains that file [the
GNAT library file] does not mean that it [the GNAT executable]
no longer is covered by the GPL. [The GNAT executable is covered
by the GPL because the non-library files in GNAT are covered
by the GLP.]
If your executable is produced by linking only your own proprietry code
and the GNAT libraries, then it is NOT covered by the GPL.
] All of the above still has me very confused. You need to make it
]crystal clear to lawyers that there is not a problem. I do not think that
]you and Robert Dewar have completely re-assured Richard, Britt and me that
]there is not a problem.
If your executable is produced by linking only your own proprietry code
and the GNAT libraries, then it is NOT covered by the GPL.
I'm sure that Rober Dewar, Richard Kenner, or Richard Stallman
will confirm this for you if you ask them.
--
Fergus Henderson <f...@cs.mu.oz.au> | "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh> | of excellence is a lethal habit"
PGP: finger f...@128.250.37.3 | -- the last words of T. S. Garp.
Richard Kenner
In article <560nst$b...@flood.weeg.uiowa.edu> Whi...@CRPL.Cedar-Rapids.lib.IA.US (Robert S. White) writes:
> Huh? What file? So the GPL still applies?
In general, no. Let me try again.
Consider two files: R, which is in the GNAT RTL and covered by the
"special exception" and X, some GPL'ed file not part of GNAT and which
does not have this exception.
If you make an executable containing X, but not R, clearly the GPL
applies to that executable.
If you make an executable containing R, but not X, the special
exception means that the GPL does *not* apply to that executable.
The last sentence is there for the case of an executable containing
*both* X and R. It is making it clear that if you had an executable
containing X which is subject to the GPL, you cannot avoid having the
GPL apply to that executable by *adding* R.
Clear now?
>All of the above still has me very confused. You need to make it
>crystal clear to lawyers that there is not a problem.
It's logically impossible to prove a negative. Sorry.
>We do not want to spread FUD. We want to tell upper management that this
>is NOT a barrier. In the meantime, other companies have a competitive
>advantage over ACT for our business.
Why is that? Do you know any compiler whose run-time libraries are
*not* copyrighted and licensed? In *all* cases, you need to carefully
read the applicable terms and conditions to make sure you can legally
use them in your executables and what, if any, restrictions they
impose on redistribution of your product. Be sure your lawyers review
these as well.
By that measure, GNAT cannot possibly be worse than any other compiler
because it imposes *no* restrictions whatsoever.
But you need to decide what compiler is best for you using whatever
criteria you find important and make your choice on that basis.
Robert Dewar
Fergus says
"If your executable is produced by linking only your own proprietry code
and the GNAT libraries, then it is NOT covered by the GPL.
I'm sure that Rober Dewar, Richard Kenner, or Richard Stallman
will confirm this for you if you ask them."
Right, more accurately, the provision in the GPL that requires availability
of source, and transfer of the right to redistribute does not apply (these
are the only two items that would be worrisome if you want to create a
non-redistribtable program where you retain trade secret rights to the
sources).
Robert White is still confused it would appear. My advice to him is to
have his lawyer explain the situation, that's what lawyers are for. If
you are in the business of including other people's code in your own,
then no matter what the source, you have to be very careful of the
legal situation (we are sure to be careful in the GNU world when we
include code that comes from other sources!)
If your lawyer is confused, or thinks that there is a problem, then the
lawyer should contact us, and we will be happy to explain in more detail.
Robert Dewar
Ada Core Technologies
Robert Dewar
iRobert White said
"it. But it is not easy to straighten out corperate lawyers after they make
broad based pronouncments about GNU software. This will be interesting to see
if we can make them modify their position."
It hardly seems fair to talk about "straightening out" the lawyers here.
They made pronouncements on certain contractual instruments, namely the
GPL and LGPL, and deemed that neither was accceptable for your purposes.
Well that's not surprising, it is because of such problems that we have
a different set of license conditoins for the GNAT runtime sources.
If you want useful output from lawyers, you have to give them relevant
input!
Give your lawyers specifically the license agreement in question, i.e.
a copy of the GPL, with the additional paragraphs, and then ask them
if there is a problem. If they think there is a problem, then have them
get in touch with us, just as you would do with any vendor if you have
a problem with the licesnse conditions on their runtime.
As Richard notes, the GNAT runtime is the least restrictive it could be,
so it is least likely to cause you trouble!