[1927] in SIPB_Linux_Development
Re: Can we release this now?
daemon@ATHENA.MIT.EDU (Salvatore Valente)
Mon Nov 24 20:17:41 1997
Date: Mon, 24 Nov 1997 20:17:07 -0500
To: amu@MIT.EDU
Cc: linux-dev@MIT.EDU
In-Reply-To: <udlwwi7rn5g.fsf@tux.mit.edu> (amu@MIT.EDU)
From: Salvatore Valente <svalente@MIT.EDU>
Aaron wrote:
> They use different versions of the X11 libraries but
> www.xfree86.org claims that they should be completely compatable.
At the *source* level, yes. Programs linked against newer versions of
the libraries may want Xkb-related symbols, which the older version
doesn't provide; I challenge you to prove backward binary
compatibility.
I love a good challenge. Unfortunately, I can't provide a mathmatical
proof, I can only offer empiracle evidence.
As a test program, I built xmcd on snork (running RH 4.2).
snork % ldd xmcd
libXt.so.6 => /usr/X11R6/lib/libXt.so.6.0
libX11.so.6 => /usr/X11R6/lib/libX11.so.6.1
libc.so.5 => /lib/libc.so.5.3.12
libSM.so.6 => /usr/X11R6/lib/libSM.so.6.0
libICE.so.6 => /usr/X11R6/lib/libICE.so.6.3
Then I ran it on keesh (running RH 4.0).
keesh % ldd xmcd
libXt.so.6 => /usr/X11R6/lib/libXt.so.6.0
libX11.so.6 => /usr/X11R6/lib/libX11.so.6.0
libc.so.5 => /lib/libc.so.5.3.12
libSM.so.6 => /usr/X11R6/lib/libSM.so.6.0
libICE.so.6 => /usr/X11R6/lib/libICE.so.6.0
It worked fine. It did not output any warnings or errors.
So I still claim that a 4.2 machine can be used as a build engine even
though there are still 4.0 machines out there.
I counter-challenge you to provide a reasonable example of a program
that, when built on a 4.2 machine, will not run on a 4.0 machine. (A
"reasonable" example means a program that could be compiled on a 4.0
machine.)
Have a nice day.
-Sal.
