port-evbarm/48668: Raspberry Pi evbarm kernels fail to build with sources as of March 19, 2014

[dhgutteridge%sympatico.ca@localhost]

>Number:         48668
>Category:       port-evbarm
>Synopsis:       Raspberry Pi evbarm kernels fail to build with sources as of 
>March 19, 2014
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-evbarm-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 20 04:35:00 +0000 2014
>Originator:     David H. Gutteridge
>Release:        6.99.37 sources as of March 19, 2014
>Organization:
>Environment:
NetBSD arcusiii.nonus-porta.net 5.2_STABLE NetBSD 5.2_STABLE (ARCUSIII) #19: 
Wed Jan  1 21:19:53 EST 2014  
disciple%arcusiii.nonus-porta.net@localhost:/home/disciple/netbsd-5/usr/src/sys/arch/i386/compile/obj/ARCUSIII
 i386

>Description:
When compiling a new Raspberry Pi kernel (my first since updating to
sources that include GCC 4.8.3), I've encountered the following error:

#   compile  ARCUSVIII/bcm2835_bsc.o
/usr/builds/netbsd-current/src/obj/tooldir.NetBSD-5.2_STABLE-i386/bin/arm--netbsdelf-gcc
 -pipe -O2 -mfloat-abi=soft -ffreestanding -fno-zero-initialized-in-bss -pipe 
-O2 -msoft-float -fno-strict-aliasing -fno-common -std=gnu99 -Werror -Wall 
-Wno-main -Wno-format-zero-length -Wpointer-arith -Wmissing-prototypes 
-Wstrict-prototypes -Wold-style-definition -Wswitch -Wshadow -Wcast-qual 
-Wwrite-strings -Wno-unreachable-code -Wno-pointer-sign -Wno-attributes 
-Wno-sign-compare --sysroot=/usr/builds/netbsd-current/src/obj/destdir.evbarm 
-march=armv6z -mtune=arm1176jzf-s -mfpu=vfp -I. 
-I/usr/builds/netbsd-current/src/sys/../common/include 
-I/usr/builds/netbsd-current/src/sys/arch -I/usr/builds/netbsd-current/src/sys 
-nostdinc -D__HAVE_CPU_COUNTER -D__HAVE_FAST_SOFTINTS 
-D__HAVE_CPU_UAREA_ALLOC_IDLELWP -DKERNEL_BASE_EXT=0xc0000000 
-DARM_GENERIC_TODR -DBCM2835 -DPLCONSOLE -DMAXUSERS=32 -D_KERNEL -D_KERNEL_OPT 
-std=gnu99 -I/usr/builds/netbsd-current/src/sys/lib/libkern/../../../common/li
 b/libc/quad 
-I/usr/builds/netbsd-current/src/sys/lib/libkern/../../../common/lib/libc/string
 
-I/usr/builds/netbsd-current/src/sys/lib/libkern/../../../common/lib/libc/arch/arm/string
 -I/usr/builds/netbsd-current/src/sys/dist/pf 
-I/usr/builds/netbsd-current/src/sys/external/bsd/common/include 
-I/usr/builds/netbsd-current/src/sys/external/bsd 
-I/usr/builds/netbsd-current/src/sys/external/bsd/dwc2/dist 
-I/usr/builds/netbsd-current/src/sys/external/bsd/vchiq/dist 
-I/usr/builds/netbsd-current/src/sys/external/bsd/common/include 
-DVCOS_VERIFY_BKPTS=1 -DUSE_VCHIQ_ARM -D__VCCOREVER__=0x04000000 
-DVCHIQ_ENABLE_DEBUG=1 -DVCHIQ_LOG_DEFAULT=5 -c 
/usr/builds/netbsd-current/src/sys/arch/arm/broadcom/bcm2835_bsc.c
/usr/builds/netbsd-current/src/sys/arch/arm/broadcom/bcm2835_bsc.c: In function 
'bsciic_acquire_bus':
/usr/builds/netbsd-current/src/sys/arch/arm/broadcom/bcm2835_bsc.c:172:11: 
error: variable 's' set but not used [-Werror=unused-but-set-variable]
  uint32_t s;
           ^
cc1: all warnings being treated as errors
*** [bcm2835_bsc.o] Error code 1

It's complaining about the following code:

static int
bsciic_acquire_bus(void *v, int flags)
{
        struct bsciic_softc * const sc = v;
        uint32_t s;

        mutex_enter(&sc->sc_buslock);

        bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, BSC_S_CLKT |
            BSC_S_ERR | BSC_S_DONE);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_I2CEN |
            BSC_C_CLEAR_CLEAR);
        s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S);
        KASSERT((s & BSC_S_TA) == 0);

        return 0;
}


>How-To-Repeat:
Try compiling a Raspberry Pi kernel with current sources.
>Fix:
--- bcm2835_bsc.c.orig  2013-01-05 15:15:17.000000000 -0500
+++ bcm2835_bsc.c       2014-03-20 00:34:43.000000000 -0400
@@ -169,7 +169,7 @@
 bsciic_acquire_bus(void *v, int flags)
 {
        struct bsciic_softc * const sc = v;
-       uint32_t s;
+       uint32_t s __diagused;
 
        mutex_enter(&sc->sc_buslock);