port-sparc/39942: kernel crossbuild fails with "unused variable 'ch0_is_cons'"

[jdbaker%mylinuxisp.com@localhost]

>Number:         39942
>Category:       port-sparc
>Synopsis:       kernel crossbuild fails with "unused variable 'ch0_is_cons'"
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-sparc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Nov 17 18:15:00 +0000 2008
>Originator:     John D. Baker
>Release:        NetBSD4.0_STABLE, NetBSD 5.0_BETA
>Organization:
>Environment:
Host:
NetBSD drmemory.bozonet.ntc 4.0_STABLE NetBSD 4.0_STABLE (DRMEMORY) #3: Wed Sep 
17 06:34:25 CDT 2008  
sysop%drmemory.bozonet.ntc@localhost:/d0/nbsd/netbsd-4/obj/i386/sys/arch/i386/compile/DRMEMORY
 i386

Target:
NetBSD artychoke.bozonet.ntc 4.0_STABLE NetBSD 4.0_STABLE (ARTYCHOKE) #9: Fri 
Oct 10 09:22:29 CDT 2008  
sysop%drmemory.bozonet.ntc@localhost:/d0/nbsd/netbsd-4/obj/sparc/sys/arch/sparc/compile/ARTYCHOKE
 sparc

>Description:
Cross-building NetBSD-5.0_BETA/sparc on NetBSD-4.0_STABLE/i386.

Target machine will be serial-console only SUN4M, so unused driver and
attachment points are commented out as follows (this works fine with
NetBSD-4.0_STABLE/sparc):

[...]
#### Serial port configuration

## Zilog 8530 serial chips.  Each has two-channels.
## zs0 is ttya and ttyb.  zs1 is the keyboard and mouse.
#zs0    at mainbus0                                     # sun4c
zs0     at obio0                                        # sun4m
#zs0    at obio0 addr 0xf1000000 level 12               # sun4/200 and sun4/300
#zs0    at obio0 addr 0x01000000 level 12               # sun4/100
#zs0    at bootbus0                                     # sun4d
zstty0  at zs0 channel 0                                # ttya
zstty1  at zs0 channel 1                                # ttyb

#zs1    at mainbus0                                     # sun4c
#zs1    at obio0                                        # sun4m
#zs1    at obio0 addr 0xf0000000 level 12               # sun4/200 and sun4/300
#zs1    at obio0 addr 0x00000000 level 12               # sun4/100
#zs1    at bootbus0                                     # sun4d
#kbd0   at zs1 channel 0                                # keyboard
#ms0    at zs1 channel 1                                # mouse

#zs2    at obio0 addr 0xe0000000 level 12               # sun4/300
#zstty2 at zs2 channel 0                                # ttyc
#zstty3 at zs2 channel 1                                # ttyd

#zs*    at bootbus?                                     # sun4d
#zstty* at zs?
[...]


Which results in the following error:
[...]
#   compile  ARTYCHOKE/zs.o
/d0/nbsd/netbsd-5/src/../tools/i386/bin/sparc--netbsdelf-gcc -mno-fpu 
-ffreestanding -fno-zero-initialized-in-bss -O2 -std=gnu99 -fno-strict-aliasing 
-Werror -Wall -Wno-main -Wno-format-zero-length -Wpointer-arith 
-Wmissing-prototypes -Wstrict-prototypes -Wswitch -Wshadow -Wcast-qual 
-Wwrite-strings -Wno-unreachable-code -Wno-sign-compare -Wno-pointer-sign 
-Wno-attributes -Werror -mcpu=v8 -I. 
-I/d0/nbsd/netbsd-5/src/sys/../common/include -I/d0/nbsd/netbsd-5/src/sys/arch 
-I/d0/nbsd/netbsd-5/src/sys -nostdinc -DMAXUSERS=8 -D_KERNEL -D_KERNEL_OPT 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/quad 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/string 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/arch/sparc/string
 -I/d0/nbsd/netbsd-5/src/sys/dist/pf -c 
/d0/nbsd/netbsd-5/src/sys/arch/sparc/dev/zs.c
cc1: warnings being treated as errors
/d0/nbsd/netbsd-5/src/sys/arch/sparc/dev/zs.c: In function 'zs_attach':
/d0/nbsd/netbsd-5/src/sys/arch/sparc/dev/zs.c:400: warning: unused variable 
'ch0_is_cons'

*** Failed target:  zs.o
*** Failed command: echo '# ' "compile ARTYCHOKE/zs.o"; echo 
/d0/nbsd/netbsd-5/src/../tools/i386/bin/sparc--netbsdelf-gcc -mno-fpu 
-ffreestanding -fno-zero-initialized-in-bss -O2 -std=gnu99 -fno-strict-aliasing 
-Werror -Wall -Wno-main -Wno-format-zero-length -Wpointer-arith 
-Wmissing-prototypes -Wstrict-prototypes -Wswitch -Wshadow -Wcast-qual 
-Wwrite-strings -Wno-unreachable-code -Wno-sign-compare -Wno-pointer-sign 
-Wno-attributes -Werror -mcpu=v8 -I. 
-I/d0/nbsd/netbsd-5/src/sys/../common/include -I/d0/nbsd/netbsd-5/src/sys/arch 
-I/d0/nbsd/netbsd-5/src/sys -nostdinc -DMAXUSERS=8 -D_KERNEL -D_KERNEL_OPT 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/quad 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/string 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/arch/sparc/string
 -I/d0/nbsd/netbsd-5/src/sys/dist/pf -c 
/d0/nbsd/netbsd-5/src/sys/arch/sparc/dev/zs.c; 
/d0/nbsd/netbsd-5/src/../tools/i386/bin/sparc--netbsdelf-gcc -mno-fp
 u -ffreestanding -fno-zero-initialized-in-bss -O2 -std=gnu99 
-fno-strict-aliasing -Werror -Wall -Wno-main -Wno-format-zero-length 
-Wpointer-arith -Wmissing-prototypes -Wstrict-prototypes -Wswitch -Wshadow 
-Wcast-qual -Wwrite-strings -Wno-unreachable-code -Wno-sign-compare 
-Wno-pointer-sign -Wno-attributes -Werror -mcpu=v8 -I. 
-I/d0/nbsd/netbsd-5/src/sys/../common/include -I/d0/nbsd/netbsd-5/src/sys/arch 
-I/d0/nbsd/netbsd-5/src/sys -nostdinc -DMAXUSERS=8 -D_KERNEL -D_KERNEL_OPT 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/quad 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/string 
-I/d0/nbsd/netbsd-5/src/sys/lib/libkern/../../../common/lib/libc/arch/sparc/string
 -I/d0/nbsd/netbsd-5/src/sys/dist/pf -c 
/d0/nbsd/netbsd-5/src/sys/arch/sparc/dev/zs.c
*** Error code 1

Stop.
nbmake: stopped in /d0/nbsd/netbsd-5/obj/sparc/sys/arch/sparc/compile/ARTYCHOKE

ERROR: Failed to make all in 
/d0/nbsd/netbsd-5/src/../obj/sparc/sys/arch/sparc/compile/ARTYCHOKE
*** BUILD ABORTED ***

>How-To-Repeat:
Configure serial drivers as shown above.  Specifically, enable:

  zs1 at obio     # or any attachment point

and disable:

  kbd0 at zs1 channel 0

and attempt to build kernel.


>Fix:
Workaround:  enable zs1 and kbd0 devices.

Possibly this patch, to match the use case:

Index: sys/arch/sparc/dev/zs.c
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc/dev/zs.c,v
retrieving revision 1.111
diff -u -r1.111 zs.c
--- sys/arch/sparc/dev/zs.c     13 Jun 2008 13:10:18 -0000      1.111
+++ sys/arch/sparc/dev/zs.c     17 Nov 2008 18:10:39 -0000
@@ -397,7 +397,10 @@
        struct zs_chanstate *cs;
        int s, channel;
        static int didintr, prevpri;
+#if NWSKBD == 0        
+#else
        int ch0_is_cons = 0;
+#endif
 
        if (zsd == NULL) {
                aprint_error(": configuration incomplete\n");