Re: GPL and GCC profiling

[Tobias Oberstein <tobias dot oberstein at gmx dot de>]

Eljay,

> When you say "...using GCC..." I presume that you are using it to 
> produce a new application (one that doesn't violate the extensions to 
> GCC's GPL).

sorry: by "using GCC" i'm referring to the situation when
i have C++ source code completely unrelated to GCC/GNU and
feed it through GCC to produce native machine code.
that is GCC used as a blackbox tool.

> I'm not part of FSF.  I'm not a lawyer.  My comments are merely my naive 
> understanding.

that's great. i never expected hard legal advice but exactly those
little hints and ptrs you share. thanks for those.

> GCC has a very liberal license regarding using GCC to produce 
> applications, even if the other application is not GPL.  Even if the 
> other application is wholly proprietary.  (Except in a few instances, as 
> specified in GCC's GPL extensions ... those few instances are, 
> basically, to protect GCC itself from being lifted and repackaged as 
> proprietary).

my understanding of GCC/GPL up 'til recently was, that
in the described situation both the C++ source code and
the resulting native machine code can be placed under any
license (if you have full author rights of course):
properietory, BSD with advertising clause, any GPL incompatible
license, whatever ..

now i became aware of a FAQ (for MinGW) about GCC and profiling:

[quote from http://www.mingw.org/mingwfaq.shtml:
Profiled code, which is code compiled and linked with the -pg option for 
runtime profiling, also falls under the GNU General Public License. 
CAUTION: do not distribute proprietary source with profiling enabled. 
The profiling library is covered by the GPL which infects your product 
to conform to the GPL as well.
]

The GPL FAQ says:

[quote from http://www.gnu.org/licenses/gpl-faq.html#GPLOutput:
In what cases is the output of a GPL program covered by the GPL too?
    Only when the program copies part of itself into the output.
]

my current understanding is this:

i guess when building software with GCC and profiling enabled, GCC
puts profiling code into the resulting executable. the resulting
exectuable would be covered by GPL and thus not immediately
publishing the source that led to that executable means a
violation of the GPL.

so even if we don't dsitribute a release version of our software
with profiling code, using profiling while developing the software
infects our source.

so my interpretation is that one can't use GCC _with profiling_
to develop software licensed under a license incompatible
with the GPL.

or does it only mean i must release source if i distribute an
executable containing GCC profiling code? and what does
"distribute" then include?

this is all very obscure to me.

> If you have concerns about GCC and use in your product, you should 
> contact your company's lawyers and have them review the GCC GPL & 
> extensions, and read and interpret the GCC GPL & extensions for yourself.

well, do you think i can realistically find a lawyer who
understands all legal implication of using GCC/GPL'ed tools in
building software with GPL-incompatible license? you know one?

> Note - this forum is made up of a community of a GCC users.  A self-help 
> group.  There are few FSF members, and I presume that those who do 
> frequent this forum are not in a position to give legal advice about GPL 
> and/or the GCC extensions to it.

does it mean you would go posting to a list on http://www.fsf.org
instead?

> In other words, what you read on this forum is opinion and interpretation.
>
> Sincerely,
> --Eljay

Cheers,
Tobias