?RCS: $Id: libs.U 167 2013-05-08 17:58:00Z rmanfredi $
?RCS:
?RCS: Copyright (c) 1991-1997, 2004-2006, Raphael Manfredi
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic License,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic License; a copy of which may be found at the root
?RCS: of the source tree for dist 4.0.
?RCS:
?RCS: $Log: libs.U,v $
?RCS: Revision 3.0.1.6  1997/02/28  16:09:11  ram
?RCS: patch61: replaced .a with $_a all over the place
?RCS:
?RCS: Revision 3.0.1.5  1995/07/25  14:12:05  ram
?RCS: patch56: now knows about OS/2 platforms
?RCS:
?RCS: Revision 3.0.1.4  1994/10/29  16:24:22  ram
?RCS: patch36: removed old broken thislib/thatlib processing (ADO)
?RCS:
?RCS: Revision 3.0.1.3  1994/06/20  07:05:44  ram
?RCS: patch30: code cleanup with if/elif by ADO and RAM
?RCS: patch30: undone patch23 for libswanted default setting
?RCS:
?RCS: Revision 3.0.1.2  1994/05/06  15:08:45  ram
?RCS: patch23: now includes ordered default libswanted variable (ADO)
?RCS: patch23: major cleanup for library lookups (ADO)
?RCS:
?RCS: Revision 3.0.1.1  1993/08/25  14:02:31  ram
?RCS: patch6: added default for libs
?RCS:
?RCS: Revision 3.0  1993/08/18  12:09:03  ram
?RCS: Baseline for dist 3.0 netwide release.
?RCS:
?MAKE:libs libsfound libsfiles libsdirs libspath libscheck: \
	test cat Myread Oldconfig Loc libpth package xlibpth so _a \
	+usesocks sed +cc +ccflags +ldflags rm
?MAKE:	-pick add $@ %<
?S:libs:
?S:	This variable holds the additional libraries we want to use.
?S:	It is up to the Makefile to deal with it.  The list can be empty.
?S:.
?S:libsfound:
?S:	This variable holds the full pathnames of the libraries
?S:	we found and accepted.
?S:.
?S:libsfiles:
?S:	This variable holds the filenames aka basenames of the libraries
?S:	we found and accepted.
?S:.
?S:libsdirs:
?S:	This variable holds the directory names aka dirnames of the libraries
?S:	we found and accepted, duplicates are removed.
?S:.
?S:libspath:
?S:	This variable holds the directory names probed for libraries.
?S:.
?S:libscheck:
?S:	This variable is intended to be set by hint files, if needed.
?S:	It should contain shell code that will be eval'ed with $xxx holding
?S:	some library file.  It may change $xxx if needed.
?S:	For instance, on an Irix platform, you may make sure the right
?S:	library file is used depending on the cc command line, so that the
?S:	correct library is used depending on the selected ABI (for 32 and
?S:	64-bit compilations).
?S:	
?S:	Here is an example of code that could be found in a hint file on Irix
?S:	when the selected compiler was for 32-bit -- that code is put in the
?S:	cc.cbu call-back unit to be invoked AFTER the C compiler and its
?S:	flags have been chosen:
?S:	
?S:		libscheck='case "$xxx" in
?S:		*.a) /bin/ar p $xxx `/bin/ar t $xxx | sed q` >$$.o;
?S:			case "`/usr/bin/file $$.o`" in
?S:			*N32*) rm -f $$.o ;;  
?S:			*) rm -f $$.o; xxx=/no/n32$xxx ;;
?S:			esac ;;
?S:		*)	case "`/usr/bin/file $xxx`" in
?S:			*N32*) ;;
?S:			*) xxx=/no/n32$xxx ;;
?S:			esac ;;
?S:		esac'
?S:.
?D:libs=''
?LINT:extern libswanted
?LINT:change libswanted
?INIT:: default library list
?INIT:libswanted=''
?X: This order is chosen so that libraries  -lndir, -ldir, -lucb, -lbsd,
?X: -lBSD, -lPW, and -lx only get used if there are unresolved
?X: routines at link time.  Usually, these are backwards compatibility
?X: libraries, and may not be as reliable as the standard c library.
?X:
?X: The -lsocket -linet -lnsl order has been reported to be necessary
?X: for at least one SVR4 implementation.
?X: -lc must proceed -lucb or -lbsd for most Solaris applications.
?X: -lc_s proceeds -lc so we pick up the shared library version, if
?X: it is available.
?X:
?X: The ordering of c, posix, and cposix is a guess and almost
?X: certainly wrong on about half of all systems.
?X:
?X: Set proper libswanted in your private Myinit.U if needed.
?X:
?X:: default ordered library list
?X:libswanted='net socket inet bind nsl nm sdbm gdbm ndbm dbm malloc dl'
?X:libswanted="$libswanted dld sun m c_s c posix cposix ndir dir ucb"
?X:libswanted="$libswanted bsd BSD PW x"
?X:
?INIT:: should be set by hint files if needed
?INIT:libscheck=''
?T:xxx yyy thislib thisdir libstyle linkmsg
?F:lt.c lt
: Looking for optional libraries
echo " "
echo "Checking for optional libraries..." >&4
case "$libs" in
' '|'') dflt='';;
*) dflt="$libs";;
esac
case "$libswanted" in
'') libswanted='c_s';;
esac
?X: libsocks has nasty naming scheme.
?X: This does not work if somebody wants SOCKS 4. 
case "$usesocks" in
"$define") libswanted="$libswanted socks5 socks5_sh" ;;
esac
?X: Used later for link checks
echo "extern void abort(void); int main(void) { abort(); return 0; }" > lt.c
libsfound=''
libsfiles=''
libsdirs=''
libspath=''
for thisdir in $libpth $xlibpth; do
  test -d $thisdir && libspath="$libspath $thisdir"
done
for thislib in $libswanted; do
	for thisdir in $libspath; do
	    xxx=''
	    if $test ! -f "$xxx" ; then
			xxx=`ls $thisdir/lib$thislib.$so.[0-9]* 2>/dev/null | $sed -n '1p'`
			$test -f "$xxx" && eval $libscheck
			$test -f "$xxx" && libstyle=shared
	    fi
	    if test ! -f "$xxx"; then
			xxx=$thisdir/lib$thislib.$so
			$test -f "$xxx" && eval $libscheck
			$test -f "$xxx" && libstyle=shared
	    fi	
	    if test ! -f "$xxx"; then
			xxx=$thisdir/lib$thislib$_a
	        $test -f "$xxx" && eval $libscheck
			$test -f "$xxx" && libstyle=static
	    fi
	    if test ! -f "$xxx"; then
			xxx=$thisdir/$thislib$_a
	        $test -f "$xxx" && eval $libscheck
			$test -f "$xxx" && libstyle=static
	    fi
	    if test ! -f "$xxx"; then
			xxx=$thisdir/lib${thislib}_s$_a
	        $test -f "$xxx" && eval $libscheck
			$test -f "$xxx" && libstyle=static
			$test -f "$xxx" && thislib=${thislib}_s
	    fi
	    if test ! -f "$xxx"; then
			xxx=$thisdir/Slib$thislib$_a
	        $test -f "$xxx" && eval $libscheck
			$test -f "$xxx" && libstyle=static
	    fi
	    if $test -f "$xxx"; then
?X:
?X: It is not sufficient to find a .so on the disk.  We must make sure
?X: that we can indeed supply the -lfoo line on the cc line to link against
?X: that library.  On Linux for instance, a versioned .so will not be
?X: implicitly linked against, whereas it will work fine on Solaris 2.6.
?X:		--RAM, 10/10/2003
?X:
			if $cc -o lt $ccflags $ldflags lt.c -l$thislib >/dev/null 2>&1;
			then
				linkmsg=""
			else
				linkmsg=" but I can't link against it"
			fi
			case "$libstyle" in
			shared) echo "Found -l$thislib (shared)$linkmsg." ;;
			static) echo "Found -l$thislib$linkmsg." ;;
			*)      echo "Found -l$thislib ($libstyle)$linkmsg." ;;
			esac
			case " $dflt " in
			*"-l$thislib "*) ;;
			*)
				case "$linkmsg" in
				'')
					dflt="$dflt -l$thislib"
					libsfound="$libsfound $xxx"
					yyy=`basename $xxx`
					libsfiles="$libsfiles $yyy"
					yyy=`echo $xxx|$sed -e "s%/$yyy\\$%%"`
					case " $libsdirs " in
					*" $yyy "*) ;;
					*) libsdirs="$libsdirs $yyy" ;;
					esac
				   ;;
				esac
				;;
			esac
			break
	    fi	
	done
	if $test ! -f "$xxx"; then
?X:
?X: Try linking against the library: gcc on linux platforms is notorious for
?X: using complex library search logic, especially on systems mixing 32-bit
?X: and 64-bit versions.
?X:
		if $cc -o lt $ccflags $ldflags lt.c -l$thislib >/dev/null 2>&1
		then
			echo "Found -l$thislib (via $cc)."
			case " $dflt " in
			*"-l$thislib "*) ;;
			*) dflt="$dflt -l$thislib";;
			esac
		else
			echo "No -l$thislib."
		fi
	fi
done
set X $dflt
shift
dflt="$*"
case "$libs" in
'') dflt="$dflt";;
*) dflt="$libs";;
esac
case "$dflt" in
' '|'') dflt='none';;
esac
$rm -f lt.c lt

$cat <<EOM

In order to compile $package on your machine, a number of libraries
are usually needed.  Include any other special libraries here as well.
Say "none" for none.  The default list is almost always right.
EOM

echo " "
rp="Which libraries to use?"
. ./myread
case "$ans" in
none) libs=' ';;
*) libs="$ans";;
esac