Re: When crosscompiling, does configure really need --build?

[Dan Kegel]

Akim Demaille wrote:
> You are supposed to run this as:
>
>       ./configure --prefix=/ --host=ppc_405 CFLAGS="-mcpu=403 -D__PPC405__"
>
> You are to tell the configure that you are cross-compiling.  It cannot
> guess it, so it is entitled to fail.  Please, read the documentation.

I must have been unclear, apologies.  I have read the documentation carefully.
http://www.gnu.org/manual/autoconf/html_mono/autoconf.html#Preset%20Output%20Variables
says to override CFLAGS in the environment, so that's what I do.

Also, I *do* give the --host flag (I must have been unclear), yet I get
the warning:
 "configure: WARNING: If you wanted to set the --build type, don't use
 --host. If a cross compiler is detected then cross compile mode will be used."

Why?

For completeness, here's info about the tools I'm using:
I'm running Debian's autoconf2.52-4 package,
which reports itself as "autoconf (GNU Autoconf) 2.52"
I'm attaching a full log of an autoconf and configure of the ntp sources,
showing the command I use and the resulting warning from configure.
- Dan

mkdir -p ppc405
set -e; \
cd ppc405; \
tar -xzvf  /home/dank/ixia_tarballs/ntp-4.1.1a.tar.gz; \
patch -p0 < ../varport.patch; \
cd ntp-4.1.1a; \
autoconf2.50; \
CC=/opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc 
AR=/opt/hardhat/devkit/ppc/405/bin/ppc_405-ar 
RANLIB=/opt/hardhat/devkit/ppc/405/bin/ppc_405-ranlib CFLAGS="-mcpu=403 
-D__PPC405__"  ./configure --prefix=/ --host=ppc-unknown-linux 
configure.in:165: warning: AC_COMPILE_IFELSE was called before AC_AIX
configure.in:166: warning: AC_COMPILE_IFELSE was called before AC_MINIX
configure.in:167: warning: AC_COMPILE_IFELSE was called before AC_ISC_POSIX
configure: WARNING: If you wanted to set the --build type, don't use --host.
    If a cross compiler is detected then cross compile mode will be used.
checking build system type... ./config.guess: ./dummy-18411: cannot execute 
binary file
i686-pc-linux-gnu
checking host system type... powerpc-unknown-linux-gnu
checking target system type... powerpc-unknown-linux-gnu
checking for a BSD compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for mawk... mawk
checking whether make sets ${MAKE}... yes
checking for ppc-unknown-linux-gcc... 
/opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc
checking for C compiler default output... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... yes
checking for executable suffix... 
checking for object suffix... o
checking whether we are using the GNU C compiler... yes
checking whether /opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc accepts -g... yes
checking for style of include used by make... GNU
checking dependency style of /opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc... gcc
checking for /opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc option to accept ANSI 
C... none needed
checking how to run the C preprocessor... 
/opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc -E
checking for mawk... (cached) mawk
checking whether make sets ${MAKE}... (cached) yes
checking whether /opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc -pipe works... yes
checking whether ln -s works... yes
checking whether /opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc needs 
-traditional... no
checking for AIX... no
checking for minix/config.h... no
checking for POSIXized ISC... no
checking for ppc-unknown-linux-ranlib... 
/opt/hardhat/devkit/ppc/405/bin/ppc_405-ranlib
checking for sh... /bin/sh
checking for perl... /usr/bin/perl
checking for a BSD compatible install... /usr/bin/install -c
checking for nlist in -lelf... no
checking for main in -lkvm... no
checking for nlist in -lld... no
checking for nlist in -lmld... no
checking for gethostent... yes
checking for openlog... yes
checking for readline in -lreadline... no
checking for setsockopt... yes
checking for ANSI C header files... yes
checking for bstring.h... no
checking for errno.h... yes
checking for fcntl.h... yes
checking for ieeefp.h... no
checking for math.h... yes
checking for memory.h... yes
checking for netdb.h... yes
checking for poll.h... yes
checking for resolv.h... yes
checking for sched.h... yes
checking for sgtty.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for termio.h... yes
checking for termios.h... yes
checking for timepps.h... no
checking for timex.h... no
checking for unistd.h... yes
checking for utmp.h... yes
checking for utmpx.h... yes
checking for arpa/nameser.h... yes
checking for net/if.h... yes
checking for netinet/in_system.h... no
checking for netinet/in_systm.h... yes
checking for netinet/in.h... yes
checking for netinet/ip.h... yes
checking for netinfo/ni.h... no
checking for sun/audioio.h... no
checking for sys/audioio.h... no
checking for sys/clkdefs.h... no
checking for sys/file.h... yes
checking for sys/ioctl.h... yes
checking for sys/lock.h... no
checking for sys/mman.h... yes
checking for sys/modem.h... no
checking for sys/param.h... yes
checking for sys/ppsclock.h... no
checking for sys/ppstime.h... no
checking for sys/proc.h... no
checking for sys/resource.h... yes
checking for sys/sched.h... no
checking for sys/select.h... yes
checking for sys/signal.h... yes
checking for sys/sockio.h... no
checking for sys/stat.h... yes
checking for sys/stream.h... no
checking for sys/stropts.h... yes
checking for sys/sysctl.h... yes
checking for sys/syssgi.h... no
checking for sys/termios.h... yes
checking for sys/time.h... yes
checking for sys/timers.h... no
checking for sys/timex.h... yes
checking for sys/tpro.h... no
checking for sys/types.h... yes
checking for sys/wait.h... yes
checking whether time.h and sys/time.h may both be included... yes
checking for nlist.h... no
checking for basic volatile support... yes
checking for /opt/hardhat/devkit/ppc/405/bin/ppc_405-gcc option to accept ANSI 
C... none needed
checking for function prototypes... yes
checking for ANSI C header files... (cached) yes
checking for string.h... (cached) yes
checking if C compiler permits function prototypes... yes
checking for an ANSI C-conforming const... yes
checking whether byte ordering is bigendian... yes
checking return type of signal handlers... void
checking for sys/types.h... (cached) yes
checking for sys/stat.h... (cached) yes
checking for stdlib.h... (cached) yes
checking for string.h... (cached) yes
checking for memory.h... (cached) yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... (cached) yes
checking for off_t... yes
checking for size_t... yes
checking for time_t... yes
checking whether struct tm is in sys/time.h or time.h... time.h
checking for a fallback value for HZ... 100
checking if we need to override the system's value for HZ... no
checking struct sigaction for sa_sigaction... yes
checking for struct ppsclockev... no
checking struct sockaddr for sa_len... no
checking struct clockinfo for hz... no
checking struct clockinfo for tickadj... no
checking for struct timespec... yes
checking for struct ntptimeval... yes
checking for struct ntptimeval.time.tv_nsec... no
checking for inline... inline
checking whether char is unsigned... yes
checking for signed char... yes
checking size of signed char... 1
checking for int... yes
checking size of int... 4
checking for long... yes
checking size of long... 4
checking for s_char... no
checking for uid_t in sys/types.h... yes
checking for __adjtimex... yes
checking for __ntp_gettime... no
checking for clock_gettime... no
checking for clock_settime... no
checking for daemon... yes
checking for finite... yes
checking for getbootfile... no
checking for getclock... no
checking for getdtablesize... yes
checking for getrusage... yes
checking for gettimeofday... yes
checking for getuid... yes
checking for hstrerror... yes
checking for K_open... no
checking for kvm_open... no
checking for memcpy... yes
checking for memmove... yes
checking for memset... yes
checking for mkstemp... yes
checking for mktime... yes
checking for mlockall... yes
checking for mrand48... yes
checking for srand48... yes
checking for nice... yes
checking for nlist... no
checking for ntp_adjtime... yes
checking for ntp_gettime... yes
checking for plock... no
checking for pututline... yes
checking for pututxline... yes
checking for readlink... yes
checking for rtprio... no
checking for sched_setscheduler... yes
checking for setlinebuf... yes
checking for setpgid... yes
checking for setpriority... yes
checking for setsid... yes
checking for settimeofday... yes
checking for setvbuf... yes
checking for sigaction... yes
checking for sigvec... yes
checking for sigset... yes
checking for sigsuspend... yes
checking for stime... yes
checking for strchr... yes
checking for sysconf... yes
checking for sysctl... yes
checking for snprintf... yes
checking for strdup... yes
checking for strerror... yes
checking for timer_create... no
checking for timer_settime... no
checking for umask... yes
checking for uname... yes
checking for updwtmp... yes
checking for updwtmpx... yes
checking for vsprintf... yes
checking number of arguments to gettimeofday()... 2
checking number of arguments taken by setpgrp()... 0
checking argument pointer type of qsort()'s compare function and base... void
checking if we need to declare 'errno'... no
checking if we may declare 'h_errno'... yes
checking if declaring 'char *sys_errlist[]' is ok... no
checking if declaring 'syscall()' is ok... no
checking if we should use a streams device for ifconfig... no
checking if we need extra room for SO_RCVBUF... no
checking if we will open the broadcast socket... no
checking if we want the HPUX version of FindConfig()... no
checking if process groups are set with -pid... yes
checking if we need a ctty for F_SETOWN... no
checking if we'll use clock_settime or settimeofday or stime... settimeofday()
configure: WARNING: *** But clock_settime() would be better (if we had it) ***
checking if we have a losing syscall()... no
checking for Streams/TLI... no
checking for SIGIO... yes
checking if we want to use signalled IO... no
checking for SIGPOLL... yes
checking for SIGSYS... yes
checking if we can use SIGPOLL for UDP I/O... no
checking if we can use SIGPOLL for TTY I/O... no
checking if nlist() values might require extra indirection... no
checking for a minimum recommended value of tickadj... no
checking if the TTY code permits PARENB and IGNPAR... no
checking if we're including debugging code... yes
checking for a the number of minutes in a DST adjustment... 60
checking if we have the tty_clk line discipline/streams module... 
checking for the ppsclock streams module... no
checking for kernel multicast support... yes
checking availability of ntp_{adj,get}time()... libc
checking if sys/timex.h has STA_FLL... yes
checking if we have kernel PLL support... yes
checking if SIOCGIFCONF returns buffer size in the buffer... no
checking ioctl TIOCGPPSEV... no
checking ioctl TIOCSPPS... no
checking ioctl CIOGETEV... no
checking for linux/serial.h... yes
checking ioctl TIOCGSERIAL... no
checking SHMEM_STATUS support... yes
checking for hopf serial clock device... 
checking for hopf PCI clock 6039... 
checking Datum/Bancomm bc635/VME interface... no
checking TrueTime GPS receiver/VME interface... no
checking for PCL720 clock support... no
checking for SHM clock attached thru shared memory... no
checking for default inclusion of all suitable non-PARSE clocks... yes
checking if we have support for PARSE clocks... yes
checking if we have support for audio clocks... no
checking ACTS modem service... yes
checking Arbiter 1088A/B GPS receiver... yes
checking Arcron MSF receiver... yes
checking ATOM PPS interface... yes
checking Austron 2200A/2201A GPS receiver... yes
checking CHU modem/decoder... yes
checking CHU audio/decoder... no
checking Datum Programmable Time System... yes
checking Forum Graphic GPS... yes
checking Heath GC-1000 WWV/WWVH receiver... yes
checking HP 58503A GPS receiver... yes
checking Sun IRIG audio decoder... no
checking for JJY receiver... yes
checking Leitch CSD 5300 Master Clock System Driver... yes
checking local clock reference... yes
checking EES M201 MSF receiver... yes
checking Magnavox MX4200 GPS receiver... no
checking NMEA GPS receiver... yes
checking for ONCORE Motorola VP/UT Oncore GPS... no
checking for Palisade clock... yes
checking PST/Traconex 1020 WWV/WWVH receiver... yes
checking Rockwell Jupiter GPS receiver... no
checking PTB modem service... yes
checking KSI/Odetics TPRO/S GPS receiver/IRIG interface... no
checking TRAK 8810 GPS receiver... yes
checking Chrono-log K-series WWVB receiver... yes
checking Dumb generic hh:mm:ss local clock... yes
checking Conrad parallel port radio clock... yes
checking Spectracom 8170/Netclock/2 WWVB receiver... yes
checking Kinemetrics/TrueTime receivers... yes
checking TrueTime 560 IRIG-B decoder... no
checking Ultralink M320 WWVB receiver... yes
checking WWV receiver... no
checking USNO modem service... yes
checking for Zyfer receiver... yes
checking for default inclusion of all suitable PARSE clocks... no
checking Diem Computime Radio Clock... no
checking ELV/DCF7000 clock... no
checking HOPF 6021 clock... no
checking Meinberg clocks... no
checking DCF77 raw time code... no
checking RCC 8000 clock... no
checking Schmid DCF77 clock... no
checking Trimble GPS receiver/TAIP protocol... no
checking Trimble GPS receiver/TSIP protocol... no
checking WHARTON 400A Series clock... no
checking VARITEXT clock... no
checking if we need to make and use the parse libraries... no
checking for openssl library directory... no
checking for openssl include directory... no
checking for the level of crypto support... no
checking if we want to compile with ElectricFence... no
checking if we can make dcf parse utilities... no
checking if we can build kernel streams modules for parse... no
checking if we need basic refclock support... yes
checking if we want HP-UX adjtimed support... no
checking if we can read kmem... no
checking if adjtime is accurate... yes
checking the name of 'tick' in the kernel... _tick
checking for the units of 'tick'... usec
checking the name of 'tickadj' in the kernel... _tickadj
checking for the units of 'tickadj'... usec
checking half-heartedly for 'dosynctodr' in the kernel... _dosynctodr
checking half-heartedly for 'noprintf' in the kernel... _noprintf
checking for a default value for 'tick'... txc.tick
checking for a default value for 'tickadj'... 500/hz
checking if we want and can make the ntptime utility... yes
checking if we want and can make the tickadj utility... (cached) yes
checking if we want and can make the timetrim utility... no
checking if we want UDP wildcard delivery... yes
checking if we should always slew the time... no
checking if we should step and slew the time... no
checking if ntpdate should step the time... no
checking if we should sync TODR clock every hour... no
checking if we should avoid kernel FLL bug... no
configure: creating ./config.status
config.status: creating Makefile
config.status: creating adjtimed/Makefile
config.status: creating clockstuff/Makefile
config.status: creating ElectricFence/Makefile
config.status: creating include/Makefile
config.status: creating kernel/Makefile
config.status: creating kernel/sys/Makefile
config.status: creating libntp/Makefile
config.status: creating libparse/Makefile
config.status: creating librsaref/Makefile
config.status: creating ntpd/Makefile
config.status: creating ntpdc/Makefile
config.status: creating ntpdate/Makefile
config.status: creating ntpq/Makefile
config.status: creating ntptrace/Makefile
config.status: creating parseutil/Makefile
config.status: creating scripts/Makefile
config.status: creating scripts/calc_tickadj
config.status: creating scripts/checktime
config.status: creating scripts/freq_adj
config.status: creating scripts/mkver
config.status: creating scripts/ntp-wait
config.status: creating scripts/ntpsweep
config.status: creating scripts/ntpver
config.status: creating scripts/plot_summary
config.status: creating scripts/summary
config.status: creating util/Makefile
config.status: creating config.h