perl-5.16.2/hints/linux.sh - toolchain/perl - Git at Google

 # hints/linux.sh
 # Original version by rsanders
 # Additional support by Kenneth Albanowski <kjahds@kjahds.com>
 #
 # ELF support by H.J. Lu <hjl@nynexst.com>
 # Additional info from Nigel Head <nhead@ESOC.bitnet>
 # and Kenneth Albanowski <kjahds@kjahds.com>
 #
 # Consolidated by Andy Dougherty <doughera@lafayette.edu>
 #
 # Updated Thu Feb  8 11:56:10 EST 1996

 # Updated Thu May 30 10:50:22 EDT 1996 by <doughera@lafayette.edu>

 # Updated Fri Jun 21 11:07:54 EDT 1996
 # NDBM support for ELF re-enabled by <kjahds@kjahds.com>

 # No version of Linux supports setuid scripts.
 d_suidsafe='undef'

 # No version of Linux needs libutil for perl.
 i_libutil='undef'

 # Debian and Red Hat, and perhaps other vendors, provide both runtime and
 # development packages for some libraries.  The runtime packages contain shared
 # libraries with version information in their names (e.g., libgdbm.so.1.7.3);
 # the development packages supplement this with versionless shared libraries
 # (e.g., libgdbm.so).
 #
 # If you want to link against such a library, you must install the development
 # version of the package.
 #
 # These packages use a -dev naming convention in both Debian and Red Hat:
 #   libgdbmg1  (non-development version of GNU libc 2-linked GDBM library)
 #   libgdbmg1-dev (development version of GNU libc 2-linked GDBM library)
 # So make sure that for any libraries you wish to link Perl with under
 # Debian or Red Hat you have the -dev packages installed.

 # SuSE Linux can be used as cross-compilation host for Cray XT4 Catamount/Qk.
 if test -d /opt/xt-pe
 then
   case "`cc -V 2>&1`" in
   *catamount*) . hints/catamount.sh; return ;;
   esac
 fi

 # Some operating systems (e.g., Solaris 2.6) will link to a versioned shared
 # library implicitly.  For example, on Solaris, `ld foo.o -lgdbm' will find an
 # appropriate version of libgdbm, if one is available; Linux, however, doesn't
 # do the implicit mapping.
 ignore_versioned_solibs='y'

 # BSD compatibility library no longer needed
 # 'kaffe' has a /usr/lib/libnet.so which is not at all relevant for perl.
 # bind causes issues with several reentrant functions
 set `echo X "$libswanted "| sed -e 's/ bsd / /' -e 's/ net / /' -e 's/ bind / /'`
 shift
 libswanted="$*"

 # Debian 4.0 puts ndbm in the -lgdbm_compat library.
 libswanted="$libswanted gdbm_compat"

 # If you have glibc, then report the version for ./myconfig bug reporting.
 # (Configure doesn't need to know the specific version since it just uses
 # gcc to load the library for all tests.)
 # We don't use __GLIBC__ and  __GLIBC_MINOR__ because they
 # are insufficiently precise to distinguish things like
 # libc-2.0.6 and libc-2.0.7.
 if test -L /lib/libc.so.6; then
     libc=`ls -l /lib/libc.so.6 | awk '{print $NF}'`
     libc=/lib/$libc
 fi

 # Configure may fail to find lstat() since it's a static/inline
 # function in <sys/stat.h>.
 d_lstat=define

 # malloc wrap works
 case "$usemallocwrap" in
 '') usemallocwrap='define' ;;
 esac

 # The system malloc() is about as fast and as frugal as perl's.
 # Since the system malloc() has been the default since at least
 # 5.001, we might as well leave it that way.  --AD  10 Jan 2002
 case "$usemymalloc" in
 '') usemymalloc='n' ;;
 esac

 # Check if we're about to use Intel's ICC compiler
 case "`${cc:-cc} -V 2>&1`" in
 *"Intel(R) C++ Compiler"*|*"Intel(R) C Compiler"*)
     # record the version, formats:
     # icc (ICC) 10.1 20080801
     # icpc (ICC) 10.1 20080801
     # followed by a copyright on the second line
     ccversion=`${cc:-cc} --version | sed -n -e 's/^icp\?c \((ICC) \)\?//p'`
     # This is needed for Configure's prototype checks to work correctly
     # The -mp flag is needed to pass various floating point related tests
     # The -no-gcc flag is needed otherwise, icc pretends (poorly) to be gcc
     ccflags="-we147 -mp -no-gcc $ccflags"
     # Prevent relocation errors on 64bits arch
     case "`uname -m`" in
 	*ia64*|*x86_64*)
 	    cccdlflags='-fPIC'
 	;;
     esac
     # If we're using ICC, we usually want the best performance
     case "$optimize" in
     '') optimize='-O3' ;;
     esac
     ;;
 *" Sun "*"C"*)
     # Sun's C compiler, which might have a 'tag' name between
     # 'Sun' and the 'C':  Examples:
     # cc: Sun C 5.9 Linux_i386 Patch 124871-01 2007/07/31
     # cc: Sun Ceres C 5.10 Linux_i386 2008/07/10
     test "$optimize" || optimize='-xO2'
     cccdlflags='-KPIC'
     lddlflags='-G -Bdynamic'
     # Sun C doesn't support gcc attributes, but, in many cases, doesn't
     # complain either.  Not all cases, though.
     d_attribute_format='undef'
     d_attribute_malloc='undef'
     d_attribute_nonnull='undef'
     d_attribute_noreturn='undef'
     d_attribute_pure='undef'
     d_attribute_unused='undef'
     d_attribute_warn_unused_result='undef'
     ;;
 esac

 case "$optimize" in
 # use -O2 by default ; -O3 doesn't seem to bring significant benefits with gcc
 '')
     optimize='-O2'
     case "`uname -m`" in
         ppc*)
             # on ppc, it seems that gcc (at least gcc 3.3.2) isn't happy
             # with -O2 ; so downgrade to -O1.
             optimize='-O1'
         ;;
         ia64*)
             # This architecture has had various problems with gcc's
             # in the 3.2, 3.3, and 3.4 releases when optimized to -O2.  See
             # RT #37156 for a discussion of the problem.
             case "`${cc:-gcc} -v 2>&1`" in
             *"version 3.2"*|*"version 3.3"*|*"version 3.4"*)
                 ccflags="-fno-delete-null-pointer-checks $ccflags"
             ;;
             esac
         ;;
     esac
     ;;
 esac

 # Ubuntu 11.04 (and later, presumably) doesn't keep most libraries
 # (such as -lm) in /lib or /usr/lib.  So we have to ask gcc to tell us
 # where to look.  We don't want gcc's own libraries, however, so we
 # filter those out.
 # This could be conditional on Unbuntu, but other distributions may
 # follow suit, and this scheme seems to work even on rather old gcc's.
 # This unconditionally uses gcc because even if the user is using another
 # compiler, we still need to find the math library and friends, and I don't
 # know how other compilers will cope with that situation.
 # Morever, if the user has their own gcc earlier in $PATH than the system gcc,
 # we don't want its libraries. So we try to prefer the system gcc
 # Still, as an escape hatch, allow Configure command line overrides to
 # plibpth to bypass this check.
 if [ -x /usr/bin/gcc ] ; then
     gcc=/usr/bin/gcc
 else
     gcc=gcc
 fi

 case "$plibpth" in
 '') plibpth=`LANG=C LC_ALL=C $gcc -print-search-dirs | grep libraries |
 	cut -f2- -d= | tr ':' $trnl | grep -v 'gcc' | sed -e 's:/$::'`
     set X $plibpth # Collapse all entries on one line
     shift
     plibpth="$*"
     ;;
 esac

 # Are we using ELF?  Thanks to Kenneth Albanowski <kjahds@kjahds.com>
 # for this test.
 cat >try.c <<'EOM'
 /* Test for whether ELF binaries are produced */
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
 main() {
 	char buffer[4];
 	int i=open("a.out",O_RDONLY);
 	if(i==-1)
 		exit(1); /* fail */
 	if(read(i,&buffer[0],4)<4)
 		exit(1); /* fail */
 	if(buffer[0] != 127 || buffer[1] != 'E' ||
            buffer[2] != 'L' || buffer[3] != 'F')
 		exit(1); /* fail */
 	exit(0); /* succeed (yes, it's ELF) */
 }
 EOM
 if ${cc:-gcc} try.c >/dev/null 2>&1 && $run ./a.out; then
     cat <<'EOM' >&4

 You appear to have ELF support.  I'll try to use it for dynamic loading.
 If dynamic loading doesn't work, read hints/linux.sh for further information.
 EOM

 else
     cat <<'EOM' >&4

 You don't have an ELF gcc.  I will use dld if possible.  If you are
 using a version of DLD earlier than 3.2.6, or don't have it at all, you
 should probably upgrade. If you are forced to use 3.2.4, you should
 uncomment a couple of lines in hints/linux.sh and restart Configure so
 that shared libraries will be disallowed.

 EOM
     lddlflags="-r $lddlflags"
     # These empty values are so that Configure doesn't put in the
     # Linux ELF values.
     ccdlflags=' '
     cccdlflags=' '
     ccflags="-DOVR_DBL_DIG=14 $ccflags"
     so='sa'
     dlext='o'
     nm_so_opt=' '
     ## If you are using DLD 3.2.4 which does not support shared libs,
     ## uncomment the next two lines:
     #ldflags="-static"
     #so='none'

 	# In addition, on some systems there is a problem with perl and NDBM
 	# which causes AnyDBM and NDBM_File to lock up. This is evidenced
 	# in the tests as AnyDBM just freezing.  Apparently, this only
 	# happens on a.out systems, so we disable NDBM for all a.out linux
 	# systems.  If someone can suggest a more robust test
 	#  that would be appreciated.
 	#
 	# More info:
 	# Date: Wed, 7 Feb 1996 03:21:04 +0900
 	# From: Jeffrey Friedl <jfriedl@nff.ncl.omron.co.jp>
 	#
 	# I tried compiling with DBM support and sure enough things locked up
 	# just as advertised. Checking into it, I found that the lockup was
 	# during the call to dbm_open. Not *in* dbm_open -- but between the call
 	# to and the jump into.
 	#
 	# To make a long story short, making sure that the *.a and *.sa pairs of
 	#   /usr/lib/lib{m,db,gdbm}.{a,sa}
 	# were perfectly in sync took care of it.
 	#
 	# This will generate a harmless Whoa There! message
 	case "$d_dbm_open" in
 	'')	cat <<'EOM' >&4

 Disabling ndbm.  This will generate a Whoa There message in Configure.
 Read hints/linux.sh for further information.
 EOM
 		# You can override this with Configure -Dd_dbm_open
 		d_dbm_open=undef
 		;;
 	esac
 fi

 rm -f try.c a.out

 if /bin/sh -c exit; then
   echo ''
   echo 'You appear to have a working bash.  Good.'
 else
   cat << 'EOM' >&4

 *********************** Warning! *********************
 It would appear you have a defective bash shell installed. This is likely to
 give you a failure of op/exec test #5 during the test phase of the build,
 Upgrading to a recent version (1.14.4 or later) should fix the problem.
 ******************************************************
 EOM

 fi

 # On SPARClinux,
 # The following csh consistently coredumped in the test directory
 # "/home/mikedlr/perl5.003_94/t", though not most other directories.

 #Name        : csh                    Distribution: Red Hat Linux (Rembrandt)
 #Version     : 5.2.6                        Vendor: Red Hat Software
 #Release     : 3                        Build Date: Fri May 24 19:42:14 1996
 #Install date: Thu Jul 11 16:20:14 1996 Build Host: itchy.redhat.com
 #Group       : Shells                   Source RPM: csh-5.2.6-3.src.rpm
 #Size        : 184417
 #Description : BSD c-shell

 # For this reason I suggest using the much bug-fixed tcsh for globbing
 # where available.

 # November 2001:  That warning's pretty old now and probably not so
 # relevant, especially since perl now uses File::Glob for globbing.
 # We'll still look for tcsh, but tone down the warnings.
 # Andy Dougherty, Nov. 6, 2001
 if $csh -c 'echo $version' >/dev/null 2>&1; then
     echo 'Your csh is really tcsh.  Good.'
 else
     if xxx=`./UU/loc tcsh blurfl $pth`; $test -f "$xxx"; then
 	echo "Found tcsh.  I'll use it for globbing."
 	# We can't change Configure's setting of $csh, due to the way
 	# Configure handles $d_portable and commands found in $loclist.
 	# We can set the value for CSH in config.h by setting full_csh.
 	full_csh=$xxx
     elif [ -f "$csh" ]; then
 	echo "Couldn't find tcsh.  Csh-based globbing might be broken."
     fi
 fi

 # Shimpei Yamashita <shimpei@socrates.patnet.caltech.edu>
 # Message-Id: <33EF1634.B36B6500@pobox.com>
 #
 # The DR2 of MkLinux (osname=linux,archname=ppc-linux) may need
 # special flags passed in order for dynamic loading to work.
 # instead of the recommended:
 #
 # ccdlflags='-rdynamic'
 #
 # it should be:
 # ccdlflags='-Wl,-E'
 #
 # So if your DR2 (DR3 came out summer 1998, consider upgrading)
 # has problems with dynamic loading, uncomment the
 # following three lines, make distclean, and re-Configure:
 #case "`uname -r | sed 's/^[0-9.-]*//'``arch`" in
 #'osfmach3ppc') ccdlflags='-Wl,-E' ;;
 #esac

 case "`uname -m`" in
 sparc*)
 	case "$cccdlflags" in
 	*-fpic*) cccdlflags="`echo $cccdlflags|sed 's/-fpic/-fPIC/'`" ;;
 	*-fPIC*) ;;
 	*)	 cccdlflags="$cccdlflags -fPIC" ;;
 	esac
 	;;
 esac

 # SuSE8.2 has /usr/lib/libndbm* which are ld scripts rather than
 # true libraries. The scripts cause binding against static
 # version of -lgdbm which is a bad idea. So if we have 'nm'
 # make sure it can read the file
 # NI-S 2003/08/07
 if [ -r /usr/lib/libndbm.so  -a  -x /usr/bin/nm ] ; then
    if /usr/bin/nm /usr/lib/libndbm.so >/dev/null 2>&1 ; then
     echo 'Your shared -lndbm seems to be a real library.'
    else
     echo 'Your shared -lndbm is not a real library.'
     set `echo X "$libswanted "| sed -e 's/ ndbm / /'`
     shift
     libswanted="$*"
    fi
 fi


 # This script UU/usethreads.cbu will get 'called-back' by Configure
 # after it has prompted the user for whether to use threads.
 cat > UU/usethreads.cbu <<'EOCBU'
 case "$usethreads" in
 $define|true|[yY]*)
         ccflags="-D_REENTRANT -D_GNU_SOURCE $ccflags"
         if echo $libswanted | grep -v pthread >/dev/null
         then
             set `echo X "$libswanted "| sed -e 's/ c / pthread c /'`
             shift
             libswanted="$*"
         fi

 	# Somehow at least in Debian 2.2 these manage to escape
 	# the #define forest of <features.h> and <time.h> so that
 	# the hasproto macro of Configure doesn't see these protos,
 	# even with the -D_GNU_SOURCE.

 	d_asctime_r_proto="$define"
 	d_crypt_r_proto="$define"
 	d_ctime_r_proto="$define"
 	d_gmtime_r_proto="$define"
 	d_localtime_r_proto="$define"
 	d_random_r_proto="$define"

 	;;
 esac
 EOCBU

 cat > UU/uselargefiles.cbu <<'EOCBU'
 # This script UU/uselargefiles.cbu will get 'called-back' by Configure
 # after it has prompted the user for whether to use large files.
 case "$uselargefiles" in
 ''|$define|true|[yY]*)
 # Keep this in the left margin.
 ccflags_uselargefiles="-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"

 	ccflags="$ccflags $ccflags_uselargefiles"
 	;;
 esac
 EOCBU

 # Purify fails to link Perl if a "-lc" is passed into its linker
 # due to duplicate symbols.
 case "$PURIFY" in
 $define|true|[yY]*)
     set `echo X "$libswanted "| sed -e 's/ c / /'`
     shift
     libswanted="$*"
     ;;
 esac

 # If we are using g++ we must use nm and force ourselves to use
 # the /usr/lib/libc.a (resetting the libc below to an empty string
 # makes Configure to look for the right one) because the symbol
 # scanning tricks of Configure will crash and burn horribly.
 case "$cc" in
 *g++*) usenm=true
        libc=''
        ;;
 esac

 # If using g++, the Configure scan for dlopen() and (especially)
 # dlerror() might fail, easier just to forcibly hint them in.
 case "$cc" in
 *g++*)
   d_dlopen='define'
   d_dlerror='define'
   ;;
 esac

 # Under some circumstances libdb can get built in such a way as to
 # need pthread explicitly linked.

 libdb_needs_pthread="N"

 if echo " $libswanted " | grep -v " pthread " >/dev/null
 then
    if echo " $libswanted " | grep " db " >/dev/null
    then
      for DBDIR in $glibpth
      do
        DBLIB="$DBDIR/libdb.so"
        if [ -f $DBLIB ]
        then
          if nm -u $DBLIB | grep pthread >/dev/null
          then
            if ldd $DBLIB | grep pthread >/dev/null
            then
              libdb_needs_pthread="N"
            else
              libdb_needs_pthread="Y"
            fi
          fi
        fi
      done
    fi
 fi

 case "$libdb_needs_pthread" in
   "Y")
     libswanted="$libswanted pthread"
     ;;
 esac
	# hints/linux.sh
	# Original version by rsanders
	# Additional support by Kenneth Albanowski <kjahds@kjahds.com>
	#
	# ELF support by H.J. Lu <hjl@nynexst.com>
	# Additional info from Nigel Head <nhead@ESOC.bitnet>
	# and Kenneth Albanowski <kjahds@kjahds.com>
	#
	# Consolidated by Andy Dougherty <doughera@lafayette.edu>
	#
	# Updated Thu Feb 8 11:56:10 EST 1996

	# Updated Thu May 30 10:50:22 EDT 1996 by <doughera@lafayette.edu>

	# Updated Fri Jun 21 11:07:54 EDT 1996
	# NDBM support for ELF re-enabled by <kjahds@kjahds.com>

	# No version of Linux supports setuid scripts.
	d_suidsafe='undef'

	# No version of Linux needs libutil for perl.
	i_libutil='undef'

	# Debian and Red Hat, and perhaps other vendors, provide both runtime and
	# development packages for some libraries. The runtime packages contain shared
	# libraries with version information in their names (e.g., libgdbm.so.1.7.3);
	# the development packages supplement this with versionless shared libraries
	# (e.g., libgdbm.so).
	#
	# If you want to link against such a library, you must install the development
	# version of the package.
	#
	# These packages use a -dev naming convention in both Debian and Red Hat:
	# libgdbmg1 (non-development version of GNU libc 2-linked GDBM library)
	# libgdbmg1-dev (development version of GNU libc 2-linked GDBM library)
	# So make sure that for any libraries you wish to link Perl with under
	# Debian or Red Hat you have the -dev packages installed.

	# SuSE Linux can be used as cross-compilation host for Cray XT4 Catamount/Qk.
	if test -d /opt/xt-pe
	then
	case "`cc -V 2>&1`" in
	catamount) . hints/catamount.sh; return ;;
	esac
	fi

	# Some operating systems (e.g., Solaris 2.6) will link to a versioned shared
	# library implicitly. For example, on Solaris, `ld foo.o -lgdbm' will find an
	# appropriate version of libgdbm, if one is available; Linux, however, doesn't
	# do the implicit mapping.
	ignore_versioned_solibs='y'

	# BSD compatibility library no longer needed
	# 'kaffe' has a /usr/lib/libnet.so which is not at all relevant for perl.
	# bind causes issues with several reentrant functions
	set `echo X "$libswanted "\| sed -e 's/ bsd / /' -e 's/ net / /' -e 's/ bind / /'`
	shift
	libswanted="$*"

	# Debian 4.0 puts ndbm in the -lgdbm_compat library.
	libswanted="$libswanted gdbm_compat"

	# If you have glibc, then report the version for ./myconfig bug reporting.
	# (Configure doesn't need to know the specific version since it just uses
	# gcc to load the library for all tests.)
	# We don't use __GLIBC__ and __GLIBC_MINOR__ because they
	# are insufficiently precise to distinguish things like
	# libc-2.0.6 and libc-2.0.7.
	if test -L /lib/libc.so.6; then
	libc=`ls -l /lib/libc.so.6 \| awk '{print $NF}'`
	libc=/lib/$libc
	fi

	# Configure may fail to find lstat() since it's a static/inline
	# function in <sys/stat.h>.
	d_lstat=define

	# malloc wrap works
	case "$usemallocwrap" in
	'') usemallocwrap='define' ;;
	esac

	# The system malloc() is about as fast and as frugal as perl's.
	# Since the system malloc() has been the default since at least
	# 5.001, we might as well leave it that way. --AD 10 Jan 2002
	case "$usemymalloc" in
	'') usemymalloc='n' ;;
	esac

	# Check if we're about to use Intel's ICC compiler
	case "`${cc:-cc} -V 2>&1`" in
	"Intel(R) C++ Compiler"\|"Intel(R) C Compiler")
	# record the version, formats:
	# icc (ICC) 10.1 20080801
	# icpc (ICC) 10.1 20080801
	# followed by a copyright on the second line
	ccversion=`${cc:-cc} --version \| sed -n -e 's/^icp\?c \((ICC) \)\?//p'`
	# This is needed for Configure's prototype checks to work correctly
	# The -mp flag is needed to pass various floating point related tests
	# The -no-gcc flag is needed otherwise, icc pretends (poorly) to be gcc
	ccflags="-we147 -mp -no-gcc $ccflags"
	# Prevent relocation errors on 64bits arch
	case "`uname -m`" in
	ia64\|x86_64)
	cccdlflags='-fPIC'
	;;
	esac
	# If we're using ICC, we usually want the best performance
	case "$optimize" in
	'') optimize='-O3' ;;
	esac
	;;
	" Sun ""C"*)
	# Sun's C compiler, which might have a 'tag' name between
	# 'Sun' and the 'C': Examples:
	# cc: Sun C 5.9 Linux_i386 Patch 124871-01 2007/07/31
	# cc: Sun Ceres C 5.10 Linux_i386 2008/07/10
	test "$optimize" \|\| optimize='-xO2'
	cccdlflags='-KPIC'
	lddlflags='-G -Bdynamic'
	# Sun C doesn't support gcc attributes, but, in many cases, doesn't
	# complain either. Not all cases, though.
	d_attribute_format='undef'
	d_attribute_malloc='undef'
	d_attribute_nonnull='undef'
	d_attribute_noreturn='undef'
	d_attribute_pure='undef'
	d_attribute_unused='undef'
	d_attribute_warn_unused_result='undef'
	;;
	esac

	case "$optimize" in
	# use -O2 by default ; -O3 doesn't seem to bring significant benefits with gcc
	'')
	optimize='-O2'
	case "`uname -m`" in
	ppc*)
	# on ppc, it seems that gcc (at least gcc 3.3.2) isn't happy
	# with -O2 ; so downgrade to -O1.
	optimize='-O1'
	;;
	ia64*)
	# This architecture has had various problems with gcc's
	# in the 3.2, 3.3, and 3.4 releases when optimized to -O2. See
	# RT #37156 for a discussion of the problem.
	case "`${cc:-gcc} -v 2>&1`" in
	"version 3.2"\|"version 3.3"\|"version 3.4")
	ccflags="-fno-delete-null-pointer-checks $ccflags"
	;;
	esac
	;;
	esac
	;;
	esac

	# Ubuntu 11.04 (and later, presumably) doesn't keep most libraries
	# (such as -lm) in /lib or /usr/lib. So we have to ask gcc to tell us
	# where to look. We don't want gcc's own libraries, however, so we
	# filter those out.
	# This could be conditional on Unbuntu, but other distributions may
	# follow suit, and this scheme seems to work even on rather old gcc's.
	# This unconditionally uses gcc because even if the user is using another
	# compiler, we still need to find the math library and friends, and I don't
	# know how other compilers will cope with that situation.
	# Morever, if the user has their own gcc earlier in $PATH than the system gcc,
	# we don't want its libraries. So we try to prefer the system gcc
	# Still, as an escape hatch, allow Configure command line overrides to
	# plibpth to bypass this check.
	if [ -x /usr/bin/gcc ] ; then
	gcc=/usr/bin/gcc
	else
	gcc=gcc
	fi

	case "$plibpth" in
	'') plibpth=`LANG=C LC_ALL=C $gcc -print-search-dirs \| grep libraries \|
	cut -f2- -d= \| tr ':' $trnl \| grep -v 'gcc' \| sed -e 's:/$::'`
	set X $plibpth # Collapse all entries on one line
	shift
	plibpth="$*"
	;;
	esac

	# Are we using ELF? Thanks to Kenneth Albanowski <kjahds@kjahds.com>
	# for this test.
	cat >try.c <<'EOM'
	/* Test for whether ELF binaries are produced */
	#include <fcntl.h>
	#include <stdlib.h>
	#include <unistd.h>
	main() {
	char buffer[4];
	int i=open("a.out",O_RDONLY);
	if(i==-1)
	exit(1); /* fail */
	if(read(i,&buffer[0],4)<4)
	exit(1); /* fail */
	if(buffer[0] != 127 \|\| buffer[1] != 'E' \|\|
	buffer[2] != 'L' \|\| buffer[3] != 'F')
	exit(1); /* fail */
	exit(0); /* succeed (yes, it's ELF) */
	}
	EOM
	if ${cc:-gcc} try.c >/dev/null 2>&1 && $run ./a.out; then
	cat <<'EOM' >&4

	You appear to have ELF support. I'll try to use it for dynamic loading.
	If dynamic loading doesn't work, read hints/linux.sh for further information.
	EOM

	else
	cat <<'EOM' >&4

	You don't have an ELF gcc. I will use dld if possible. If you are
	using a version of DLD earlier than 3.2.6, or don't have it at all, you
	should probably upgrade. If you are forced to use 3.2.4, you should
	uncomment a couple of lines in hints/linux.sh and restart Configure so
	that shared libraries will be disallowed.

	EOM
	lddlflags="-r $lddlflags"
	# These empty values are so that Configure doesn't put in the
	# Linux ELF values.
	ccdlflags=' '
	cccdlflags=' '
	ccflags="-DOVR_DBL_DIG=14 $ccflags"
	so='sa'
	dlext='o'
	nm_so_opt=' '
	## If you are using DLD 3.2.4 which does not support shared libs,
	## uncomment the next two lines:
	#ldflags="-static"
	#so='none'

	# In addition, on some systems there is a problem with perl and NDBM
	# which causes AnyDBM and NDBM_File to lock up. This is evidenced
	# in the tests as AnyDBM just freezing. Apparently, this only
	# happens on a.out systems, so we disable NDBM for all a.out linux
	# systems. If someone can suggest a more robust test
	# that would be appreciated.
	#
	# More info:
	# Date: Wed, 7 Feb 1996 03:21:04 +0900
	# From: Jeffrey Friedl <jfriedl@nff.ncl.omron.co.jp>
	#
	# I tried compiling with DBM support and sure enough things locked up
	# just as advertised. Checking into it, I found that the lockup was
	# during the call to dbm_open. Not in dbm_open -- but between the call
	# to and the jump into.
	#
	# To make a long story short, making sure that the .a and .sa pairs of
	# /usr/lib/lib{m,db,gdbm}.{a,sa}
	# were perfectly in sync took care of it.
	#
	# This will generate a harmless Whoa There! message
	case "$d_dbm_open" in
	'') cat <<'EOM' >&4

	Disabling ndbm. This will generate a Whoa There message in Configure.
	Read hints/linux.sh for further information.
	EOM
	# You can override this with Configure -Dd_dbm_open
	d_dbm_open=undef
	;;
	esac
	fi

	rm -f try.c a.out

	if /bin/sh -c exit; then
	echo ''
	echo 'You appear to have a working bash. Good.'
	else
	cat << 'EOM' >&4

	********************* Warning! *******************
	It would appear you have a defective bash shell installed. This is likely to
	give you a failure of op/exec test #5 during the test phase of the build,
	Upgrading to a recent version (1.14.4 or later) should fix the problem.
	******************************************************
	EOM

	fi

	# On SPARClinux,
	# The following csh consistently coredumped in the test directory
	# "/home/mikedlr/perl5.003_94/t", though not most other directories.

	#Name : csh Distribution: Red Hat Linux (Rembrandt)
	#Version : 5.2.6 Vendor: Red Hat Software
	#Release : 3 Build Date: Fri May 24 19:42:14 1996
	#Install date: Thu Jul 11 16:20:14 1996 Build Host: itchy.redhat.com
	#Group : Shells Source RPM: csh-5.2.6-3.src.rpm
	#Size : 184417
	#Description : BSD c-shell

	# For this reason I suggest using the much bug-fixed tcsh for globbing
	# where available.

	# November 2001: That warning's pretty old now and probably not so
	# relevant, especially since perl now uses File::Glob for globbing.
	# We'll still look for tcsh, but tone down the warnings.
	# Andy Dougherty, Nov. 6, 2001
	if $csh -c 'echo $version' >/dev/null 2>&1; then
	echo 'Your csh is really tcsh. Good.'
	else
	if xxx=`./UU/loc tcsh blurfl $pth`; $test -f "$xxx"; then
	echo "Found tcsh. I'll use it for globbing."
	# We can't change Configure's setting of $csh, due to the way
	# Configure handles $d_portable and commands found in $loclist.
	# We can set the value for CSH in config.h by setting full_csh.
	full_csh=$xxx
	elif [ -f "$csh" ]; then
	echo "Couldn't find tcsh. Csh-based globbing might be broken."
	fi
	fi

	# Shimpei Yamashita <shimpei@socrates.patnet.caltech.edu>
	# Message-Id: <33EF1634.B36B6500@pobox.com>
	#
	# The DR2 of MkLinux (osname=linux,archname=ppc-linux) may need
	# special flags passed in order for dynamic loading to work.
	# instead of the recommended:
	#
	# ccdlflags='-rdynamic'
	#
	# it should be:
	# ccdlflags='-Wl,-E'
	#
	# So if your DR2 (DR3 came out summer 1998, consider upgrading)
	# has problems with dynamic loading, uncomment the
	# following three lines, make distclean, and re-Configure:
	#case "`uname -r \| sed 's/^[0-9.-]*//'``arch`" in
	#'osfmach3ppc') ccdlflags='-Wl,-E' ;;
	#esac

	case "`uname -m`" in
	sparc*)
	case "$cccdlflags" in
	-fpic) cccdlflags="`echo $cccdlflags\|sed 's/-fpic/-fPIC/'`" ;;
	-fPIC) ;;
	*) cccdlflags="$cccdlflags -fPIC" ;;
	esac
	;;
	esac

	# SuSE8.2 has /usr/lib/libndbm* which are ld scripts rather than
	# true libraries. The scripts cause binding against static
	# version of -lgdbm which is a bad idea. So if we have 'nm'
	# make sure it can read the file
	# NI-S 2003/08/07
	if [ -r /usr/lib/libndbm.so -a -x /usr/bin/nm ] ; then
	if /usr/bin/nm /usr/lib/libndbm.so >/dev/null 2>&1 ; then
	echo 'Your shared -lndbm seems to be a real library.'
	else
	echo 'Your shared -lndbm is not a real library.'
	set `echo X "$libswanted "\| sed -e 's/ ndbm / /'`
	shift
	libswanted="$*"
	fi
	fi


	# This script UU/usethreads.cbu will get 'called-back' by Configure
	# after it has prompted the user for whether to use threads.
	cat > UU/usethreads.cbu <<'EOCBU'
	case "$usethreads" in
	$define\|true\|[yY]*)
	ccflags="-D_REENTRANT -D_GNU_SOURCE $ccflags"
	if echo $libswanted \| grep -v pthread >/dev/null
	then
	set `echo X "$libswanted "\| sed -e 's/ c / pthread c /'`
	shift
	libswanted="$*"
	fi

	# Somehow at least in Debian 2.2 these manage to escape
	# the #define forest of <features.h> and <time.h> so that
	# the hasproto macro of Configure doesn't see these protos,
	# even with the -D_GNU_SOURCE.

	d_asctime_r_proto="$define"
	d_crypt_r_proto="$define"
	d_ctime_r_proto="$define"
	d_gmtime_r_proto="$define"
	d_localtime_r_proto="$define"
	d_random_r_proto="$define"

	;;
	esac
	EOCBU

	cat > UU/uselargefiles.cbu <<'EOCBU'
	# This script UU/uselargefiles.cbu will get 'called-back' by Configure
	# after it has prompted the user for whether to use large files.
	case "$uselargefiles" in
	''\|$define\|true\|[yY]*)
	# Keep this in the left margin.
	ccflags_uselargefiles="-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"

	ccflags="$ccflags $ccflags_uselargefiles"
	;;
	esac
	EOCBU

	# Purify fails to link Perl if a "-lc" is passed into its linker
	# due to duplicate symbols.
	case "$PURIFY" in
	$define\|true\|[yY]*)
	set `echo X "$libswanted "\| sed -e 's/ c / /'`
	shift
	libswanted="$*"
	;;
	esac

	# If we are using g++ we must use nm and force ourselves to use
	# the /usr/lib/libc.a (resetting the libc below to an empty string
	# makes Configure to look for the right one) because the symbol
	# scanning tricks of Configure will crash and burn horribly.
	case "$cc" in
	g++) usenm=true
	libc=''
	;;
	esac

	# If using g++, the Configure scan for dlopen() and (especially)
	# dlerror() might fail, easier just to forcibly hint them in.
	case "$cc" in
	g++)
	d_dlopen='define'
	d_dlerror='define'
	;;
	esac

	# Under some circumstances libdb can get built in such a way as to
	# need pthread explicitly linked.

	libdb_needs_pthread="N"

	if echo " $libswanted " \| grep -v " pthread " >/dev/null
	then
	if echo " $libswanted " \| grep " db " >/dev/null
	then
	for DBDIR in $glibpth
	do
	DBLIB="$DBDIR/libdb.so"
	if [ -f $DBLIB ]
	then
	if nm -u $DBLIB \| grep pthread >/dev/null
	then
	if ldd $DBLIB \| grep pthread >/dev/null
	then
	libdb_needs_pthread="N"
	else
	libdb_needs_pthread="Y"
	fi
	fi
	fi
	done
	fi
	fi

	case "$libdb_needs_pthread" in
	"Y")
	libswanted="$libswanted pthread"
	;;
	esac