Date: Sat, 25 Jun 94 16:57:31 JST
From: Stephen Turnbull <turnbull AT shako DOT sk DOT tsukuba DOT ac DOT jp>
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: libgpl, LGPL, and DJGPP license [was: iostream unresolved externals]

According to: Paul Harness <gapa83 AT udcf DOT gla DOT ac DOT uk>

   > iostream classes.  I have been linking like this:
   > 
   > gcc -o myprog -lgpp -lgpl myprog.cc
   > 
   > and still not getting the iostreams library linked.  In

   Try gcc -o myprog myprog.cc -lgpp -lm

Right.

   libgpl is something to do with debugging. You need to link the maths

Well, a little bit different.  Libgpl is those parts of GNU CC
protected by the LGPL (as opposed to the GPL).  It includes the
obstack routines and a good regular expression parser (not as good as
flex, but you can change the expression at runtime), and maybe some
other stuff (an alloca?)  I believe that LGPL means that if you use
these routines in a program, you may provide it as a separate library
which the customer may link in.  Then you need only provide the source
to those routines, and not the rest of your program.  (*Don't* trust
this information, I haven't read the LGPL in a while.  I provide it
only because you might want to know and it is correct to the best of
my knowledge.)

As long as I'm on the subject, please remember that, according to the
docs that come with DJGPP, including a Bison parser in your program
automatically makes it subject to the GPL.  The docs predate the LGPL,
I believe, so that this *may* be a way to dodge GPL-ing your whole
program if it includes a Bison parser.  (Of course, if the important
proprietary information is the Bison grammar itself, you're hosed.)

And in response to the person who asked for a plain English
translation of the DJGPP licensing:  that *is* plain English.  If you
simplify it any more, it won't tell you precisely what you can do; it
will be wrong.  If you want examples, try reading the whole GPL and
LGPL; or if you have something specific in mind, you can always ask
DJ; assuming you have ethics rather than legalities in mind, he's the
ultimate arbiter.

   library too as some routines in libgpp use it.

   -- 
   Paul Harness,                        |  Internet: gapa83 AT udcf DOT gla DOT ac DOT uk

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|                           Stephen Turnbull                            |
|     University of Tsukuba, Institute of Socio-Economic Planning       |
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