git.sesse.net Git - vlc/blob - m4/lib-link.m4

   1 # lib-link.m4 serial 3 (gettext-0.11.3)
   2 dnl Copyright (C) 2001-2002 Free Software Foundation, Inc.
   3 dnl This file is free software, distributed under the terms of the GNU
   4 dnl General Public License.  As a special exception to the GNU General
   5 dnl Public License, this file may be distributed as part of a program
   6 dnl that contains a configuration script generated by Autoconf, under
   7 dnl the same distribution terms as the rest of that program.
   8
   9 dnl From Bruno Haible.
  10
  11 dnl AC_LIB_LINKFLAGS(name [, dependencies]) searches for libname and
  12 dnl the libraries corresponding to explicit and implicit dependencies.
  13 dnl Sets and AC_SUBSTs the LIB${NAME} and LTLIB${NAME} variables and
  14 dnl augments the CPPFLAGS variable.
  15 AC_DEFUN([AC_LIB_LINKFLAGS],
  16 [
  17   AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
  18   AC_REQUIRE([AC_LIB_RPATH])
  19   define([Name],[translit([$1],[./-], [___])])
  20   define([NAME],[translit([$1],[abcdefghijklmnopqrstuvwxyz./-],
  21                                [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])])
  22   AC_CACHE_CHECK([how to link with lib[]$1], [ac_cv_lib[]Name[]_libs], [
  23     AC_LIB_LINKFLAGS_BODY([$1], [$2])
  24     ac_cv_lib[]Name[]_libs="$LIB[]NAME"
  25     ac_cv_lib[]Name[]_ltlibs="$LTLIB[]NAME"
  26     ac_cv_lib[]Name[]_cppflags="$INC[]NAME"
  27   ])
  28   LIB[]NAME="$ac_cv_lib[]Name[]_libs"
  29   LTLIB[]NAME="$ac_cv_lib[]Name[]_ltlibs"
  30   INC[]NAME="$ac_cv_lib[]Name[]_cppflags"
  31   AC_LIB_APPENDTOVAR([CPPFLAGS], [$INC]NAME)
  32   AC_SUBST([LIB]NAME)
  33   AC_SUBST([LTLIB]NAME)
  34   dnl Also set HAVE_LIB[]NAME so that AC_LIB_HAVE_LINKFLAGS can reuse the
  35   dnl results of this search when this library appears as a dependency.
  36   HAVE_LIB[]NAME=yes
  37   undefine([Name])
  38   undefine([NAME])
  39 ])
  40
  41 dnl AC_LIB_HAVE_LINKFLAGS(name, dependencies, includes, testcode)
  42 dnl searches for libname and the libraries corresponding to explicit and
  43 dnl implicit dependencies, together with the specified include files and
  44 dnl the ability to compile and link the specified testcode. If found, it
  45 dnl sets and AC_SUBSTs HAVE_LIB${NAME}=yes and the LIB${NAME} and
  46 dnl LTLIB${NAME} variables and augments the CPPFLAGS variable, and
  47 dnl #defines HAVE_LIB${NAME} to 1. Otherwise, it sets and AC_SUBSTs
  48 dnl HAVE_LIB${NAME}=no and LIB${NAME} and LTLIB${NAME} to empty.
  49 AC_DEFUN([AC_LIB_HAVE_LINKFLAGS],
  50 [
  51   AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
  52   AC_REQUIRE([AC_LIB_RPATH])
  53   define([Name],[translit([$1],[./-], [___])])
  54   define([NAME],[translit([$1],[abcdefghijklmnopqrstuvwxyz./-],
  55                                [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])])
  56
  57   dnl Search for lib[]Name and define LIB[]NAME, LTLIB[]NAME and INC[]NAME
  58   dnl accordingly.
  59   AC_LIB_LINKFLAGS_BODY([$1], [$2])
  60
  61   dnl Add $INC[]NAME to CPPFLAGS before performing the following checks,
  62   dnl because if the user has installed lib[]Name and not disabled its use
  63   dnl via --without-lib[]Name-prefix, he wants to use it.
  64   ac_save_CPPFLAGS="$CPPFLAGS"
  65   AC_LIB_APPENDTOVAR([CPPFLAGS], [$INC]NAME)
  66
  67   AC_CACHE_CHECK([for lib[]$1], [ac_cv_lib[]Name], [
  68     ac_save_LIBS="$LIBS"
  69     LIBS="$LIBS $LIB[]NAME"
  70     AC_TRY_LINK([$3], [$4], [ac_cv_lib[]Name=yes], [ac_cv_lib[]Name=no])
  71     LIBS="$ac_save_LIBS"
  72   ])
  73   if test "$ac_cv_lib[]Name" = yes; then
  74     HAVE_LIB[]NAME=yes
  75     AC_DEFINE([HAVE_LIB]NAME, 1, [Define if you have the $1 library.])
  76     AC_MSG_CHECKING([how to link with lib[]$1])
  77     AC_MSG_RESULT([$LIB[]NAME])
  78   else
  79     HAVE_LIB[]NAME=no
  80     dnl If $LIB[]NAME didn't lead to a usable library, we don't need
  81     dnl $INC[]NAME either.
  82     CPPFLAGS="$ac_save_CPPFLAGS"
  83     LIB[]NAME=
  84     LTLIB[]NAME=
  85   fi
  86   AC_SUBST([HAVE_LIB]NAME)
  87   AC_SUBST([LIB]NAME)
  88   AC_SUBST([LTLIB]NAME)
  89   undefine([Name])
  90   undefine([NAME])
  91 ])
  92
  93 dnl Determine the platform dependent parameters needed to use rpath:
  94 dnl libext, shlibext, hardcode_libdir_flag_spec, hardcode_libdir_separator,
  95 dnl hardcode_direct, hardcode_minus_L,
  96 dnl sys_lib_search_path_spec, sys_lib_dlsearch_path_spec.
  97 AC_DEFUN([AC_LIB_RPATH],
  98 [
  99   AC_REQUIRE([AC_PROG_CC])                dnl we use $CC, $GCC, $LDFLAGS
 100   AC_REQUIRE([AC_LIB_PROG_LD])            dnl we use $LD, $with_gnu_ld
 101   AC_REQUIRE([AC_CANONICAL_HOST])         dnl we use $host
 102   AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT]) dnl we use $ac_aux_dir
 103   AC_CACHE_CHECK([for shared library run path origin], acl_cv_rpath, [
 104     CC="$CC" GCC="$GCC" LDFLAGS="$LDFLAGS" LD="$LD" with_gnu_ld="$with_gnu_ld" \
 105     ${CONFIG_SHELL-/bin/sh} "$ac_aux_dir/config.rpath" "$host" > conftest.sh
 106     . ./conftest.sh
 107     rm -f ./conftest.sh
 108     acl_cv_rpath=done
 109   ])
 110   wl="$acl_cv_wl"
 111   libext="$acl_cv_libext"
 112   shlibext="$acl_cv_shlibext"
 113   hardcode_libdir_flag_spec="$acl_cv_hardcode_libdir_flag_spec"
 114   hardcode_libdir_separator="$acl_cv_hardcode_libdir_separator"
 115   hardcode_direct="$acl_cv_hardcode_direct"
 116   hardcode_minus_L="$acl_cv_hardcode_minus_L"
 117   sys_lib_search_path_spec="$acl_cv_sys_lib_search_path_spec"
 118   sys_lib_dlsearch_path_spec="$acl_cv_sys_lib_dlsearch_path_spec"
 119   dnl Determine whether the user wants rpath handling at all.
 120   AC_ARG_ENABLE(rpath,
 121     [  --disable-rpath         do not hardcode runtime library paths],
 122     :, enable_rpath=yes)
 123 ])
 124
 125 dnl AC_LIB_LINKFLAGS_BODY(name [, dependencies]) searches for libname and
 126 dnl the libraries corresponding to explicit and implicit dependencies.
 127 dnl Sets the LIB${NAME}, LTLIB${NAME} and INC${NAME} variables.
 128 AC_DEFUN([AC_LIB_LINKFLAGS_BODY],
 129 [
 130   define([NAME],[translit([$1],[abcdefghijklmnopqrstuvwxyz./-],
 131                                [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])])
 132   dnl By default, look in $includedir and $libdir.
 133   use_additional=yes
 134   AC_LIB_WITH_FINAL_PREFIX([
 135     eval additional_includedir=\"$includedir\"
 136     eval additional_libdir=\"$libdir\"
 137   ])
 138   AC_ARG_WITH([lib$1-prefix],
 139 [  --with-lib$1-prefix[=DIR]  search for lib$1 in DIR/include and DIR/lib
 140   --without-lib$1-prefix     don't search for lib$1 in includedir and libdir],
 141 [
 142     if test "X$withval" = "Xno"; then
 143       use_additional=no
 144     else
 145       if test "X$withval" = "X"; then
 146         AC_LIB_WITH_FINAL_PREFIX([
 147           eval additional_includedir=\"$includedir\"
 148           eval additional_libdir=\"$libdir\"
 149         ])
 150       else
 151         additional_includedir="$withval/include"
 152         additional_libdir="$withval/lib"
 153       fi
 154     fi
 155 ])
 156   dnl Search the library and its dependencies in $additional_libdir and
 157   dnl $LDFLAGS. Using breadth-first-seach.
 158   LIB[]NAME=
 159   LTLIB[]NAME=
 160   INC[]NAME=
 161   rpathdirs=
 162   ltrpathdirs=
 163   names_already_handled=
 164   names_next_round='$1 $2'
 165   while test -n "$names_next_round"; do
 166     names_this_round="$names_next_round"
 167     names_next_round=
 168     for name in $names_this_round; do
 169       already_handled=
 170       for n in $names_already_handled; do
 171         if test "$n" = "$name"; then
 172           already_handled=yes
 173           break
 174         fi
 175       done
 176       if test -z "$already_handled"; then
 177         names_already_handled="$names_already_handled $name"
 178         dnl See if it was already located by an earlier AC_LIB_LINKFLAGS
 179         dnl or AC_LIB_HAVE_LINKFLAGS call.
 180         uppername=`echo "$name" | sed -e 'y|abcdefghijklmnopqrstuvwxyz./-|ABCDEFGHIJKLMNOPQRSTUVWXYZ___|'`
 181         eval value=\"\$HAVE_LIB$uppername\"
 182         if test -n "$value"; then
 183           if test "$value" = yes; then
 184             eval value=\"\$LIB$uppername\"
 185             test -z "$value" || LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$value"
 186             eval value=\"\$LTLIB$uppername\"
 187             test -z "$value" || LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }$value"
 188           else
 189             dnl An earlier call to AC_LIB_HAVE_LINKFLAGS has determined
 190             dnl that this library doesn't exist. So just drop it.
 191             :
 192           fi
 193         else
 194           dnl Search the library lib$name in $additional_libdir and $LDFLAGS
 195           dnl and the already constructed $LIBNAME/$LTLIBNAME.
 196           found_dir=
 197           found_la=
 198           found_so=
 199           found_a=
 200           if test $use_additional = yes; then
 201             if test -n "$shlibext" && test -f "$additional_libdir/lib$name.$shlibext"; then
 202               found_dir="$additional_libdir"
 203               found_so="$additional_libdir/lib$name.$shlibext"
 204               if test -f "$additional_libdir/lib$name.la"; then
 205                 found_la="$additional_libdir/lib$name.la"
 206               fi
 207             else
 208               if test -f "$additional_libdir/lib$name.$libext"; then
 209                 found_dir="$additional_libdir"
 210                 found_a="$additional_libdir/lib$name.$libext"
 211                 if test -f "$additional_libdir/lib$name.la"; then
 212                   found_la="$additional_libdir/lib$name.la"
 213                 fi
 214               fi
 215             fi
 216           fi
 217           if test "X$found_dir" = "X"; then
 218             for x in $LDFLAGS $LTLIB[]NAME; do
 219               AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 220               case "$x" in
 221                 -L*)
 222                   dir=`echo "X$x" | sed -e 's/^X-L//'`
 223                   if test -n "$shlibext" && test -f "$dir/lib$name.$shlibext"; then
 224                     found_dir="$dir"
 225                     found_so="$dir/lib$name.$shlibext"
 226                     if test -f "$dir/lib$name.la"; then
 227                       found_la="$dir/lib$name.la"
 228                     fi
 229                   else
 230                     if test -f "$dir/lib$name.$libext"; then
 231                       found_dir="$dir"
 232                       found_a="$dir/lib$name.$libext"
 233                       if test -f "$dir/lib$name.la"; then
 234                         found_la="$dir/lib$name.la"
 235                       fi
 236                     fi
 237                   fi
 238                   ;;
 239               esac
 240               if test "X$found_dir" != "X"; then
 241                 break
 242               fi
 243             done
 244           fi
 245           if test "X$found_dir" != "X"; then
 246             dnl Found the library.
 247             LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-L$found_dir -l$name"
 248             if test "X$found_so" != "X"; then
 249               dnl Linking with a shared library. We attempt to hardcode its
 250               dnl directory into the executable's runpath, unless it's the
 251               dnl standard /usr/lib.
 252               if test "$enable_rpath" = no || test "X$found_dir" = "X/usr/lib"; then
 253                 dnl No hardcoding is needed.
 254                 LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 255               else
 256                 dnl Use an explicit option to hardcode DIR into the resulting
 257                 dnl binary.
 258                 dnl Potentially add DIR to ltrpathdirs.
 259                 dnl The ltrpathdirs will be appended to $LTLIBNAME at the end.
 260                 haveit=
 261                 for x in $ltrpathdirs; do
 262                   if test "X$x" = "X$found_dir"; then
 263                     haveit=yes
 264                     break
 265                   fi
 266                 done
 267                 if test -z "$haveit"; then
 268                   ltrpathdirs="$ltrpathdirs $found_dir"
 269                 fi
 270                 dnl The hardcoding into $LIBNAME is system dependent.
 271                 if test "$hardcode_direct" = yes; then
 272                   dnl Using DIR/libNAME.so during linking hardcodes DIR into the
 273                   dnl resulting binary.
 274                   LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 275                 else
 276                   if test -n "$hardcode_libdir_flag_spec" && test "$hardcode_minus_L" = no; then
 277                     dnl Use an explicit option to hardcode DIR into the resulting
 278                     dnl binary.
 279                     LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 280                     dnl Potentially add DIR to rpathdirs.
 281                     dnl The rpathdirs will be appended to $LIBNAME at the end.
 282                     haveit=
 283                     for x in $rpathdirs; do
 284                       if test "X$x" = "X$found_dir"; then
 285                         haveit=yes
 286                         break
 287                       fi
 288                     done
 289                     if test -z "$haveit"; then
 290                       rpathdirs="$rpathdirs $found_dir"
 291                     fi
 292                   else
 293                     dnl Rely on "-L$found_dir".
 294                     dnl But don't add it if it's already contained in the LDFLAGS
 295                     dnl or the already constructed $LIBNAME
 296                     haveit=
 297                     for x in $LDFLAGS $LIB[]NAME; do
 298                       AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 299                       if test "X$x" = "X-L$found_dir"; then
 300                         haveit=yes
 301                         break
 302                       fi
 303                     done
 304                     if test -z "$haveit"; then
 305                       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$found_dir"
 306                     fi
 307                     if test "$hardcode_minus_L" != no; then
 308                       dnl FIXME: Not sure whether we should use
 309                       dnl "-L$found_dir -l$name" or "-L$found_dir $found_so"
 310                       dnl here.
 311                       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 312                     else
 313                       dnl We cannot use $hardcode_runpath_var and LD_RUN_PATH
 314                       dnl here, because this doesn't fit in flags passed to the
 315                       dnl compiler. So give up. No hardcoding. This affects only
 316                       dnl very old systems.
 317                       dnl FIXME: Not sure whether we should use
 318                       dnl "-L$found_dir -l$name" or "-L$found_dir $found_so"
 319                       dnl here.
 320                       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-l$name"
 321                     fi
 322                   fi
 323                 fi
 324               fi
 325             else
 326               if test "X$found_a" != "X"; then
 327                 dnl Linking with a static library.
 328                 LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_a"
 329               else
 330                 dnl We shouldn't come here, but anyway it's good to have a
 331                 dnl fallback.
 332                 LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$found_dir -l$name"
 333               fi
 334             fi
 335             dnl Assume the include files are nearby.
 336             additional_includedir=
 337             case "$found_dir" in
 338               */lib | */lib/)
 339                 basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e 's,/lib/*$,,'`
 340                 additional_includedir="$basedir/include"
 341                 ;;
 342             esac
 343             if test "X$additional_includedir" != "X"; then
 344               dnl Potentially add $additional_includedir to $INCNAME.
 345               dnl But don't add it
 346               dnl   1. if it's the standard /usr/include,
 347               dnl   2. if it's /usr/local/include and we are using GCC on Linux,
 348               dnl   3. if it's already present in $CPPFLAGS or the already
 349               dnl      constructed $INCNAME,
 350               dnl   4. if it doesn't exist as a directory.
 351               if test "X$additional_includedir" != "X/usr/include"; then
 352                 haveit=
 353                 if test "X$additional_includedir" = "X/usr/local/include"; then
 354                   if test -n "$GCC"; then
 355                     case $host_os in
 356                       linux*) haveit=yes;;
 357                     esac
 358                   fi
 359                 fi
 360                 if test -z "$haveit"; then
 361                   for x in $CPPFLAGS $INC[]NAME; do
 362                     AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 363                     if test "X$x" = "X-I$additional_includedir"; then
 364                       haveit=yes
 365                       break
 366                     fi
 367                   done
 368                   if test -z "$haveit"; then
 369                     if test -d "$additional_includedir"; then
 370                       dnl Really add $additional_includedir to $INCNAME.
 371                       INC[]NAME="${INC[]NAME}${INC[]NAME:+ }-I$additional_includedir"
 372                     fi
 373                   fi
 374                 fi
 375               fi
 376             fi
 377             dnl Look for dependencies.
 378             if test -n "$found_la"; then
 379               dnl Read the .la file. It defines the variables
 380               dnl dlname, library_names, old_library, dependency_libs, current,
 381               dnl age, revision, installed, dlopen, dlpreopen, libdir.
 382               save_libdir="$libdir"
 383               case "$found_la" in
 384                 */* | *\\*) . "$found_la" ;;
 385                 *) . "./$found_la" ;;
 386               esac
 387               libdir="$save_libdir"
 388               dnl We use only dependency_libs.
 389               for dep in $dependency_libs; do
 390                 case "$dep" in
 391                   -L*)
 392                     additional_libdir=`echo "X$dep" | sed -e 's/^X-L//'`
 393                     dnl Potentially add $additional_libdir to $LIBNAME and $LTLIBNAME.
 394                     dnl But don't add it
 395                     dnl   1. if it's the standard /usr/lib,
 396                     dnl   2. if it's /usr/local/lib and we are using GCC on Linux,
 397                     dnl   3. if it's already present in $LDFLAGS or the already
 398                     dnl      constructed $LIBNAME,
 399                     dnl   4. if it doesn't exist as a directory.
 400                     if test "X$additional_libdir" != "X/usr/lib"; then
 401                       haveit=
 402                       if test "X$additional_libdir" = "X/usr/local/lib"; then
 403                         if test -n "$GCC"; then
 404                           case $host_os in
 405                             linux*) haveit=yes;;
 406                           esac
 407                         fi
 408                       fi
 409                       if test -z "$haveit"; then
 410                         haveit=
 411                         for x in $LDFLAGS $LIB[]NAME; do
 412                           AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 413                           if test "X$x" = "X-L$additional_libdir"; then
 414                             haveit=yes
 415                             break
 416                           fi
 417                         done
 418                         if test -z "$haveit"; then
 419                           if test -d "$additional_libdir"; then
 420                             dnl Really add $additional_libdir to $LIBNAME.
 421                             LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$additional_libdir"
 422                           fi
 423                         fi
 424                         haveit=
 425                         for x in $LDFLAGS $LTLIB[]NAME; do
 426                           AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 427                           if test "X$x" = "X-L$additional_libdir"; then
 428                             haveit=yes
 429                             break
 430                           fi
 431                         done
 432                         if test -z "$haveit"; then
 433                           if test -d "$additional_libdir"; then
 434                             dnl Really add $additional_libdir to $LTLIBNAME.
 435                             LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-L$additional_libdir"
 436                           fi
 437                         fi
 438                       fi
 439                     fi
 440                     ;;
 441                   -R*)
 442                     dir=`echo "X$dep" | sed -e 's/^X-R//'`
 443                     if test "$enable_rpath" != no; then
 444                       dnl Potentially add DIR to rpathdirs.
 445                       dnl The rpathdirs will be appended to $LIBNAME at the end.
 446                       haveit=
 447                       for x in $rpathdirs; do
 448                         if test "X$x" = "X$dir"; then
 449                           haveit=yes
 450                           break
 451                         fi
 452                       done
 453                       if test -z "$haveit"; then
 454                         rpathdirs="$rpathdirs $dir"
 455                       fi
 456                       dnl Potentially add DIR to ltrpathdirs.
 457                       dnl The ltrpathdirs will be appended to $LTLIBNAME at the end.
 458                       haveit=
 459                       for x in $ltrpathdirs; do
 460                         if test "X$x" = "X$dir"; then
 461                           haveit=yes
 462                           break
 463                         fi
 464                       done
 465                       if test -z "$haveit"; then
 466                         ltrpathdirs="$ltrpathdirs $dir"
 467                       fi
 468                     fi
 469                     ;;
 470                   -l*)
 471                     dnl Handle this in the next round.
 472                     names_next_round="$names_next_round "`echo "X$dep" | sed -e 's/^X-l//'`
 473                     ;;
 474                   *.la)
 475                     dnl Handle this in the next round. Throw away the .la's
 476                     dnl directory; it is already contained in a preceding -L
 477                     dnl option.
 478                     names_next_round="$names_next_round "`echo "X$dep" | sed -e 's,^X.*/,,' -e 's,^lib,,' -e 's,\.la$,,'`
 479                     ;;
 480                   *)
 481                     dnl Most likely an immediate library name.
 482                     LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$dep"
 483                     LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }$dep"
 484                     ;;
 485                 esac
 486               done
 487             fi
 488           else
 489             dnl Didn't find the library; assume it is in the system directories
 490             dnl known to the linker and runtime loader. (All the system
 491             dnl directories known to the linker should also be known to the
 492             dnl runtime loader, otherwise the system is severely misconfigured.)
 493             LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-l$name"
 494             LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-l$name"
 495           fi
 496         fi
 497       fi
 498     done
 499   done
 500   if test "X$rpathdirs" != "X"; then
 501     if test -n "$hardcode_libdir_separator"; then
 502       dnl Weird platform: only the last -rpath option counts, the user must
 503       dnl pass all path elements in one option. We can arrange that for a
 504       dnl single library, but not when more than one $LIBNAMEs are used.
 505       alldirs=
 506       for found_dir in $rpathdirs; do
 507         alldirs="${alldirs}${alldirs:+$hardcode_libdir_separator}$found_dir"
 508       done
 509       dnl Note: hardcode_libdir_flag_spec uses $libdir and $wl.
 510       acl_save_libdir="$libdir"
 511       libdir="$alldirs"
 512       eval flag=\"$hardcode_libdir_flag_spec\"
 513       libdir="$acl_save_libdir"
 514       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$flag"
 515     else
 516       dnl The -rpath options are cumulative.
 517       for found_dir in $rpathdirs; do
 518         acl_save_libdir="$libdir"
 519         libdir="$found_dir"
 520         eval flag=\"$hardcode_libdir_flag_spec\"
 521         libdir="$acl_save_libdir"
 522         LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$flag"
 523       done
 524     fi
 525   fi
 526   if test "X$ltrpathdirs" != "X"; then
 527     dnl When using libtool, the option that works for both libraries and
 528     dnl executables is -R. The -R options are cumulative.
 529     for found_dir in $ltrpathdirs; do
 530       LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-R$found_dir"
 531     done
 532   fi
 533 ])
 534
 535 dnl AC_LIB_APPENDTOVAR(VAR, CONTENTS) appends the elements of CONTENTS to VAR,
 536 dnl unless already present in VAR.
 537 dnl Works only for CPPFLAGS, not for LIB* variables because that sometimes
 538 dnl contains two or three consecutive elements that belong together.
 539 AC_DEFUN([AC_LIB_APPENDTOVAR],
 540 [
 541   for element in [$2]; do
 542     haveit=
 543     for x in $[$1]; do
 544       AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 545       if test "X$x" = "X$element"; then
 546         haveit=yes
 547         break
 548       fi
 549     done
 550     if test -z "$haveit"; then
 551       [$1]="${[$1]}${[$1]:+ }$element"
 552     fi
 553   done
 554 ])