kernel build error with ACPI_DEBUG option

My kernel build failed with the following error when I used the
ACPI_DEBUG kernel option:


cc -O -pipe -mcpu=pentiumpro -I/usr/src/sys/modules/acpi/acpi/../../../contrib/dev/acpica -DACPI_DEBUG  -D_KERNEL -DKLD_MODULE -nostdinc -I-  -I/usr/src/sys/modules/acpi/acpi/../../../contrib/dev/acpica -include /usr/obj/usr/src/sys/ACPI_DEBUG/opt_global.h -I. -I_at_ -I_at_/../include -finline-limit=15000 -fno-common -g -I/usr/obj/usr/src/sys/ACPI_DEBUG -mno-align-long-strings -mpreferred-stack-boundary=2 -ffreestanding -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes  -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -fformat-extensions -std=c99 -c /usr/src/sys/dev/acpica/acpi.c
/usr/src/sys/dev/acpica/acpi.c: In function `acpi_Startup':
/usr/src/sys/dev/acpica/acpi.c:208: error: `_Dbg' undeclared (first use in this function)
/usr/src/sys/dev/acpica/acpi.c:208: error: (Each undeclared identifier is reported only once
/usr/src/sys/dev/acpica/acpi.c:208: error: for each function it appears in.)
*** Error code 1


I'm also getting the following warnings both with and without
ACPI_DEBUG:

cc -O -pipe -mcpu=pentiumpro -I/usr/src/sys/modules/acpi/acpi/../../../contrib/dev/acpica  -D_KERNEL -DKLD_MODULE -nostdinc -I-  -I/usr/src/sys/modules/acpi/acpi/../../../contrib/dev/acpica -include /usr/obj/usr/src/sys/ACPI_DEBUG/opt_global.h -I. -I_at_ -I_at_/../include -finline-limit=15000 -fno-common -g -I/usr/obj/usr/src/sys/ACPI_DEBUG -mno-align-long-strings -mpreferred-stack-boundary=2 -ffreestanding -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes  -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -fformat-extensions -std=c99 -c /usr/src/sys/contrib/dev/acpica/utglobal.c
/usr/src/sys/contrib/dev/acpica/utglobal.c: In function `AcpiUtGetRegionName':
/usr/src/sys/contrib/dev/acpica/utglobal.c:489: warning: cast discards qualifiers from pointer target type
/usr/src/sys/contrib/dev/acpica/utglobal.c: In function `AcpiUtGetEventName':
/usr/src/sys/contrib/dev/acpica/utglobal.c:527: warning: cast discards qualifiers from pointer target type
/usr/src/sys/contrib/dev/acpica/utglobal.c: In function `AcpiUtGetTypeName':
/usr/src/sys/contrib/dev/acpica/utglobal.c:597: warning: cast discards qualifiers from pointer target type
/usr/src/sys/contrib/dev/acpica/utglobal.c:600: warning: cast discards qualifiers from pointer target type
/usr/src/sys/contrib/dev/acpica/utglobal.c: In function `AcpiUtGetDescriptorName':
/usr/src/sys/contrib/dev/acpica/utglobal.c:703: warning: cast discards qualifiers from pointer target type
/usr/src/sys/contrib/dev/acpica/utglobal.c:706: warning: cast discards qualifiers from pointer target type