port-xen/50282: can't compile 7.0 Xen kernel without DDB

[jnemeth%CornerstoneService.ca@localhost]

>Number:         50282
>Category:       port-xen
>Synopsis:       can't compile 7.0 Xen kernel without DDB
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Sep 27 10:45:00 +0000 2015
>Originator:     John Nemeth
>Release:        NetBSD 7.0
>Organization:
>Environment:
System: NetBSD rel7build 7.0 NetBSD 7.0 (XEN3_DOMU) #0: Sat Sep 26 06:19:12 PDT 2015  jnemeth@rel7build:/usr/local/NetBSD-7/amd64-objdir/sys/arch/amd64/compile/XEN3_DOMU amd64
Architecture: x86_64
Machine: amd64
>Description:
	Trying to build a Xen kernel without DDB fails to link.

#      link  ADG_7_DOMU/netbsd
ld -Map netbsd.map --cref -T ../../../../arch/amd64/conf/kern.ldscript.Xen -Ttext 0xffffffff80100000 -e start -X -o netbsd ${SYSTEM_OBJ} ${EXTRA_OBJ} vers.o
locore.o: In function `cpu_switchto':
(.text+0x20bd): undefined reference to `cpu_Debugger'
xen_ipi.o: In function `xen_ipi_ddb':
xen_ipi.c:(.text+0xcc): undefined reference to `ddb_ipi'
*** Error code 1

Stop.
make: stopped in /sys/arch/amd64/compile/ADG_7_DOMU
>How-To-Repeat:
	Create a custom kernel config without DDB and try to build it.
>Fix:
	Wrap calls to DDB with appropriate protection.