>>>>>>>>
I have a user who is porting an application from Solaris to Suse linux. He
is having a problem in compiling some of his code and has a question:
> In Solaris, I have 5 different source modules that all contain the same
> data area. I can separately compile each of the source modules to objects
> and then link them all together with no complaints.
>
> When I try the same thing on Linux, ld screams bloody murder. Apparently,
> Linux ld isn't bright enough to either combine all the data areas into a
> single one or treat each one as a separate data area for that program
> only. The data area is coded in a system header file that is included in
> each of the programs (unistd.h seems to be the ornery one).
>
> Is there a linker option that controls this type of behavior on Linux?
<<<<<<<<
Actually, this sounds like the "standard problem" when dealing
with portation issues; The problem is probably in Solaris rather
than Linux.
In terms of portation techniques, you may want to encapsulate the
"global" data area definitions/declarations in a shared .h (include)
file and use a (-Dtagname) in the make file to turn on/off the
"extern" prefix in front of various data structures, to wit:
#if !defined(MAINLINE)
extern
#endif
int a,b,c,d,e,f;
...and the like. This pays off quickly since it avoids any
possibility
of common data areas becoming... ...uncommon (where it's "private"
to
a particular module). I've seen some pretty funky stuff in the past
when I used to deal with porting Thoroughbred Business BASIC to a
wide
range of Unix/Xenix platforms...
--------------------
John R. Campbell, Speaker to Machines (GNUrd) {813-356|697}-5322
"Will Work for CLAIM Codes"
IBM Certified: IBM AIX 4.3 System Administration, System Support
