On Sat, 13 Jun 1998, Ken Nakata wrote:

> Hi,
> 
> My last sup was on June 11.  I had other problems compiling tn3270
> last time I did make build so I commented tn3270 out of SUBDIRS in
> usr.bin/Makefile...  I'm doing it again since I don't use tn3270.
> Oh, BTW, /s is where I sup everything into.  And this is on mac68k if
> it matters (although I doubt it does).
> 
> Ken
> 
> # make COPTS='-O2 -pipe' build
> [...]
> all ===> usr.bin/tn3270
> all ===> usr.bin/tn3270/tn3270
> cc -O -O2 -pipe -Werror -Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith  -I/s/src/usr.bin/tn3270/tn3270/../../../lib -I/s/src/usr.bin/tn3270/tn3270/../../telnet -DTERMCAP -DSRCRT -DKLUDGELINEMODE -DUSE_TERMIO -DTN3270 -Dunix -I/s/src/usr.bin/tn3270/tn3270 -I. -c /s/src/usr.bin/tn3270/tn3270/../ctlr/api.c
> cc1: warnings being treated as errors
> In file included from /s/src/usr.bin/tn3270/tn3270/../ctlr/api.c:61:
> /s/src/usr.bin/tn3270/tn3270/../ctlr/externs.h:44: warning: function declaration isn't a prototype
> /s/src/usr.bin/tn3270/tn3270/../ctlr/externs.h:45: warning: function declaration isn't a prototype
> /s/src/usr.bin/tn3270/tn3270/../ctlr/externs.h:45: warning: function declaration isn't a prototype
> /s/src/usr.bin/tn3270/tn3270/../ctlr/externs.h:45: warning: function declaration isn't a prototype

It works for me, also on mac68k. But I don't have a ../ctlr/externs.h.
Here's an excerpt from /usr/obj/usr.bin/tn3270/tn3270/.depend:

api.o api.ln: /usr/src/usr.bin/tn3270/tn3270/../ctlr/api.c \
 /usr/include/sys/cdefs.h /usr/include/machine/cdefs.h \
 /usr/include/m68k/cdefs.h /usr/include/stdio.h \
 /usr/include/sys/types.h /usr/include/machine/types.h \
 /usr/include/m68k/types.h /usr/include/machine/ansi.h \
 /usr/include/m68k/ansi.h /usr/include/machine/endian.h \
 /usr/include/m68k/endian.h /usr/include/sys/featuretest.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/api.h /usr/include/sys/param.h \
 /usr/include/sys/syslimits.h /usr/include/sys/signal.h \
 /usr/include/machine/signal.h /usr/include/m68k/signal.h \
 /usr/include/machine/trap.h /usr/include/m68k/trap.h \
 /usr/include/machine/param.h /usr/include/machine/intr.h \
 /usr/include/m68k/param.h /usr/include/machine/psl.h \
 /usr/include/m68k/psl.h /usr/include/machine/limits.h \
 /usr/include/m68k/limits.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/../general/general.h \
 /usr/include/string.h /usr/include/strings.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/../api/disp_asc.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/screen.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/hostctlr.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/oia.h \
 /usr/src/usr.bin/tn3270/tn3270/../ctlr/declare.h \
 /usr/src/usr.bin/tn3270/tn3270/../../telnet/externs.h \
 /usr/include/stdlib.h /usr/include/setjmp.h \

It looks like it's supposed to be pulling in ../../telnet/externs.h.
Maybe you should try blowing tn3270 away, and then doing a sup with the
"old" option.