m4/lib-link.m4

   1 # lib-link.m4 serial 6 (gettext-0.14.3)
   2 dnl Copyright (C) 2001-2005 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 dnl From Bruno Haible.
   8
   9 AC_PREREQ(2.50)
  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 AC_DEFUN([AC_LIB_RPATH],
  97 [
  98   dnl Tell automake >= 1.10 to complain if config.rpath is missing.
  99   m4_ifdef([AC_REQUIRE_AUX_FILE], [AC_REQUIRE_AUX_FILE([config.rpath])])
 100   AC_REQUIRE([AC_PROG_CC])                dnl we use $CC, $GCC, $LDFLAGS
 101   AC_REQUIRE([AC_LIB_PROG_LD])            dnl we use $LD, $with_gnu_ld
 102   AC_REQUIRE([AC_CANONICAL_HOST])         dnl we use $host
 103   AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT]) dnl we use $ac_aux_dir
 104   AC_CACHE_CHECK([for shared library run path origin], acl_cv_rpath, [
 105     CC="$CC" GCC="$GCC" LDFLAGS="$LDFLAGS" LD="$LD" with_gnu_ld="$with_gnu_ld" \
 106     ${CONFIG_SHELL-/bin/sh} "$ac_aux_dir/config.rpath" "$host" > conftest.sh
 107     . ./conftest.sh
 108     rm -f ./conftest.sh
 109     acl_cv_rpath=done
 110   ])
 111   wl="$acl_cv_wl"
 112   libext="$acl_cv_libext"
 113   shlibext="$acl_cv_shlibext"
 114   hardcode_libdir_flag_spec="$acl_cv_hardcode_libdir_flag_spec"
 115   hardcode_libdir_separator="$acl_cv_hardcode_libdir_separator"
 116   hardcode_direct="$acl_cv_hardcode_direct"
 117   hardcode_minus_L="$acl_cv_hardcode_minus_L"
 118   dnl Determine whether the user wants rpath handling at all.
 119   AC_ARG_ENABLE(rpath,
 120     [  --disable-rpath         do not hardcode runtime library paths],
 121     :, enable_rpath=yes)
 122 ])
 123
 124 dnl AC_LIB_LINKFLAGS_BODY(name [, dependencies]) searches for libname and
 125 dnl the libraries corresponding to explicit and implicit dependencies.
 126 dnl Sets the LIB${NAME}, LTLIB${NAME} and INC${NAME} variables.
 127 AC_DEFUN([AC_LIB_LINKFLAGS_BODY],
 128 [
 129   define([NAME],[translit([$1],[abcdefghijklmnopqrstuvwxyz./-],
 130                                [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])])
 131   dnl By default, look in $includedir and $libdir.
 132   use_additional=yes
 133   AC_LIB_WITH_FINAL_PREFIX([
 134     eval additional_includedir=\"$includedir\"
 135     eval additional_libdir=\"$libdir\"
 136   ])
 137   AC_LIB_ARG_WITH([lib$1-prefix],
 138 [  --with-lib$1-prefix[=DIR]  search for lib$1 in DIR/include and DIR/lib
 139   --without-lib$1-prefix     don't search for lib$1 in includedir and libdir],
 140 [
 141     if test "X$withval" = "Xno"; then
 142       use_additional=no
 143     else
 144       if test "X$withval" = "X"; then
 145         AC_LIB_WITH_FINAL_PREFIX([
 146           eval additional_includedir=\"$includedir\"
 147           eval additional_libdir=\"$libdir\"
 148         ])
 149       else
 150         additional_includedir="$withval/include"
 151         additional_libdir="$withval/lib"
 152       fi
 153     fi
 154 ])
 155   dnl Search the library and its dependencies in $additional_libdir and
 156   dnl $LDFLAGS. Using breadth-first-seach.
 157   LIB[]NAME=
 158   LTLIB[]NAME=
 159   INC[]NAME=
 160   rpathdirs=
 161   ltrpathdirs=
 162   names_already_handled=
 163   names_next_round='$1 $2'
 164   while test -n "$names_next_round"; do
 165     names_this_round="$names_next_round"
 166     names_next_round=
 167     for name in $names_this_round; do
 168       already_handled=
 169       for n in $names_already_handled; do
 170         if test "$n" = "$name"; then
 171           already_handled=yes
 172           break
 173         fi
 174       done
 175       if test -z "$already_handled"; then
 176         names_already_handled="$names_already_handled $name"
 177         dnl See if it was already located by an earlier AC_LIB_LINKFLAGS
 178         dnl or AC_LIB_HAVE_LINKFLAGS call.
 179         uppername=`echo "$name" | sed -e 'y|abcdefghijklmnopqrstuvwxyz./-|ABCDEFGHIJKLMNOPQRSTUVWXYZ___|'`
 180         eval value=\"\$HAVE_LIB$uppername\"
 181         if test -n "$value"; then
 182           if test "$value" = yes; then
 183             eval value=\"\$LIB$uppername\"
 184             test -z "$value" || LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$value"
 185             eval value=\"\$LTLIB$uppername\"
 186             test -z "$value" || LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }$value"
 187           else
 188             dnl An earlier call to AC_LIB_HAVE_LINKFLAGS has determined
 189             dnl that this library doesn't exist. So just drop it.
 190             :
 191           fi
 192         else
 193           dnl Search the library lib$name in $additional_libdir and $LDFLAGS
 194           dnl and the already constructed $LIBNAME/$LTLIBNAME.
 195           found_dir=
 196           found_la=
 197           found_so=
 198           found_a=
 199           if test $use_additional = yes; then
 200             if test -n "$shlibext" && test -f "$additional_libdir/lib$name.$shlibext"; then
 201               found_dir="$additional_libdir"
 202               found_so="$additional_libdir/lib$name.$shlibext"
 203               if test -f "$additional_libdir/lib$name.la"; then
 204                 found_la="$additional_libdir/lib$name.la"
 205               fi
 206             else
 207               if test -f "$additional_libdir/lib$name.$libext"; then
 208                 found_dir="$additional_libdir"
 209                 found_a="$additional_libdir/lib$name.$libext"
 210                 if test -f "$additional_libdir/lib$name.la"; then
 211                   found_la="$additional_libdir/lib$name.la"
 212                 fi
 213               fi
 214             fi
 215           fi
 216           if test "X$found_dir" = "X"; then
 217             for x in $LDFLAGS $LTLIB[]NAME; do
 218               AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 219               case "$x" in
 220                 -L*)
 221                   dir=`echo "X$x" | sed -e 's/^X-L//'`
 222                   if test -n "$shlibext" && test -f "$dir/lib$name.$shlibext"; then
 223                     found_dir="$dir"
 224                     found_so="$dir/lib$name.$shlibext"
 225                     if test -f "$dir/lib$name.la"; then
 226                       found_la="$dir/lib$name.la"
 227                     fi
 228                   else
 229                     if test -f "$dir/lib$name.$libext"; then
 230                       found_dir="$dir"
 231                       found_a="$dir/lib$name.$libext"
 232                       if test -f "$dir/lib$name.la"; then
 233                         found_la="$dir/lib$name.la"
 234                       fi
 235                     fi
 236                   fi
 237                   ;;
 238               esac
 239               if test "X$found_dir" != "X"; then
 240                 break
 241               fi
 242             done
 243           fi
 244           if test "X$found_dir" != "X"; then
 245             dnl Found the library.
 246             LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-L$found_dir -l$name"
 247             if test "X$found_so" != "X"; then
 248               dnl Linking with a shared library. We attempt to hardcode its
 249               dnl directory into the executable's runpath, unless it's the
 250               dnl standard /usr/lib.
 251               if test "$enable_rpath" = no || test "X$found_dir" = "X/usr/lib"; then
 252                 dnl No hardcoding is needed.
 253                 LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 254               else
 255                 dnl Use an explicit option to hardcode DIR into the resulting
 256                 dnl binary.
 257                 dnl Potentially add DIR to ltrpathdirs.
 258                 dnl The ltrpathdirs will be appended to $LTLIBNAME at the end.
 259                 haveit=
 260                 for x in $ltrpathdirs; do
 261                   if test "X$x" = "X$found_dir"; then
 262                     haveit=yes
 263                     break
 264                   fi
 265                 done
 266                 if test -z "$haveit"; then
 267                   ltrpathdirs="$ltrpathdirs $found_dir"
 268                 fi
 269                 dnl The hardcoding into $LIBNAME is system dependent.
 270                 if test "$hardcode_direct" = yes; then
 271                   dnl Using DIR/libNAME.so during linking hardcodes DIR into the
 272                   dnl resulting binary.
 273                   LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 274                 else
 275                   if test -n "$hardcode_libdir_flag_spec" && test "$hardcode_minus_L" = no; then
 276                     dnl Use an explicit option to hardcode DIR into the resulting
 277                     dnl binary.
 278                     LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 279                     dnl Potentially add DIR to rpathdirs.
 280                     dnl The rpathdirs will be appended to $LIBNAME at the end.
 281                     haveit=
 282                     for x in $rpathdirs; do
 283                       if test "X$x" = "X$found_dir"; then
 284                         haveit=yes
 285                         break
 286                       fi
 287                     done
 288                     if test -z "$haveit"; then
 289                       rpathdirs="$rpathdirs $found_dir"
 290                     fi
 291                   else
 292                     dnl Rely on "-L$found_dir".
 293                     dnl But don't add it if it's already contained in the LDFLAGS
 294                     dnl or the already constructed $LIBNAME
 295                     haveit=
 296                     for x in $LDFLAGS $LIB[]NAME; do
 297                       AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 298                       if test "X$x" = "X-L$found_dir"; then
 299                         haveit=yes
 300                         break
 301                       fi
 302                     done
 303                     if test -z "$haveit"; then
 304                       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$found_dir"
 305                     fi
 306                     if test "$hardcode_minus_L" != no; then
 307                       dnl FIXME: Not sure whether we should use
 308                       dnl "-L$found_dir -l$name" or "-L$found_dir $found_so"
 309                       dnl here.
 310                       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_so"
 311                     else
 312                       dnl We cannot use $hardcode_runpath_var and LD_RUN_PATH
 313                       dnl here, because this doesn't fit in flags passed to the
 314                       dnl compiler. So give up. No hardcoding. This affects only
 315                       dnl very old systems.
 316                       dnl FIXME: Not sure whether we should use
 317                       dnl "-L$found_dir -l$name" or "-L$found_dir $found_so"
 318                       dnl here.
 319                       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-l$name"
 320                     fi
 321                   fi
 322                 fi
 323               fi
 324             else
 325               if test "X$found_a" != "X"; then
 326                 dnl Linking with a static library.
 327                 LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$found_a"
 328               else
 329                 dnl We shouldn't come here, but anyway it's good to have a
 330                 dnl fallback.
 331                 LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$found_dir -l$name"
 332               fi
 333             fi
 334             dnl Assume the include files are nearby.
 335             additional_includedir=
 336             case "$found_dir" in
 337               */lib | */lib/)
 338                 basedir=`echo "X$found_dir" | sed -e 's,^X,,' -e 's,/lib/*$,,'`
 339                 additional_includedir="$basedir/include"
 340                 ;;
 341             esac
 342             if test "X$additional_includedir" != "X"; then
 343               dnl Potentially add $additional_includedir to $INCNAME.
 344               dnl But don't add it
 345               dnl   1. if it's the standard /usr/include,
 346               dnl   2. if it's /usr/local/include and we are using GCC on Linux,
 347               dnl   3. if it's already present in $CPPFLAGS or the already
 348               dnl      constructed $INCNAME,
 349               dnl   4. if it doesn't exist as a directory.
 350               if test "X$additional_includedir" != "X/usr/include"; then
 351                 haveit=
 352                 if test "X$additional_includedir" = "X/usr/local/include"; then
 353                   if test -n "$GCC"; then
 354                     case $host_os in
 355                       linux* | gnu* | k*bsd*-gnu) haveit=yes;;
 356                     esac
 357                   fi
 358                 fi
 359                 if test -z "$haveit"; then
 360                   for x in $CPPFLAGS $INC[]NAME; do
 361                     AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 362                     if test "X$x" = "X-I$additional_includedir"; then
 363                       haveit=yes
 364                       break
 365                     fi
 366                   done
 367                   if test -z "$haveit"; then
 368                     if test -d "$additional_includedir"; then
 369                       dnl Really add $additional_includedir to $INCNAME.
 370                       INC[]NAME="${INC[]NAME}${INC[]NAME:+ }-I$additional_includedir"
 371                     fi
 372                   fi
 373                 fi
 374               fi
 375             fi
 376             dnl Look for dependencies.
 377             if test -n "$found_la"; then
 378               dnl Read the .la file. It defines the variables
 379               dnl dlname, library_names, old_library, dependency_libs, current,
 380               dnl age, revision, installed, dlopen, dlpreopen, libdir.
 381               save_libdir="$libdir"
 382               case "$found_la" in
 383                 */* | *\\*) . "$found_la" ;;
 384                 *) . "./$found_la" ;;
 385               esac
 386               libdir="$save_libdir"
 387               dnl We use only dependency_libs.
 388               for dep in $dependency_libs; do
 389                 case "$dep" in
 390                   -L*)
 391                     additional_libdir=`echo "X$dep" | sed -e 's/^X-L//'`
 392                     dnl Potentially add $additional_libdir to $LIBNAME and $LTLIBNAME.
 393                     dnl But don't add it
 394                     dnl   1. if it's the standard /usr/lib,
 395                     dnl   2. if it's /usr/local/lib and we are using GCC on Linux,
 396                     dnl   3. if it's already present in $LDFLAGS or the already
 397                     dnl      constructed $LIBNAME,
 398                     dnl   4. if it doesn't exist as a directory.
 399                     if test "X$additional_libdir" != "X/usr/lib"; then
 400                       haveit=
 401                       if test "X$additional_libdir" = "X/usr/local/lib"; then
 402                         if test -n "$GCC"; then
 403                           case $host_os in
 404                             linux* | gnu* | k*bsd*-gnu) haveit=yes;;
 405                           esac
 406                         fi
 407                       fi
 408                       if test -z "$haveit"; then
 409                         haveit=
 410                         for x in $LDFLAGS $LIB[]NAME; do
 411                           AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 412                           if test "X$x" = "X-L$additional_libdir"; then
 413                             haveit=yes
 414                             break
 415                           fi
 416                         done
 417                         if test -z "$haveit"; then
 418                           if test -d "$additional_libdir"; then
 419                             dnl Really add $additional_libdir to $LIBNAME.
 420                             LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-L$additional_libdir"
 421                           fi
 422                         fi
 423                         haveit=
 424                         for x in $LDFLAGS $LTLIB[]NAME; do
 425                           AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 426                           if test "X$x" = "X-L$additional_libdir"; then
 427                             haveit=yes
 428                             break
 429                           fi
 430                         done
 431                         if test -z "$haveit"; then
 432                           if test -d "$additional_libdir"; then
 433                             dnl Really add $additional_libdir to $LTLIBNAME.
 434                             LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-L$additional_libdir"
 435                           fi
 436                         fi
 437                       fi
 438                     fi
 439                     ;;
 440                   -R*)
 441                     dir=`echo "X$dep" | sed -e 's/^X-R//'`
 442                     if test "$enable_rpath" != no; then
 443                       dnl Potentially add DIR to rpathdirs.
 444                       dnl The rpathdirs will be appended to $LIBNAME at the end.
 445                       haveit=
 446                       for x in $rpathdirs; do
 447                         if test "X$x" = "X$dir"; then
 448                           haveit=yes
 449                           break
 450                         fi
 451                       done
 452                       if test -z "$haveit"; then
 453                         rpathdirs="$rpathdirs $dir"
 454                       fi
 455                       dnl Potentially add DIR to ltrpathdirs.
 456                       dnl The ltrpathdirs will be appended to $LTLIBNAME at the end.
 457                       haveit=
 458                       for x in $ltrpathdirs; do
 459                         if test "X$x" = "X$dir"; then
 460                           haveit=yes
 461                           break
 462                         fi
 463                       done
 464                       if test -z "$haveit"; then
 465                         ltrpathdirs="$ltrpathdirs $dir"
 466                       fi
 467                     fi
 468                     ;;
 469                   -l*)
 470                     dnl Handle this in the next round.
 471                     names_next_round="$names_next_round "`echo "X$dep" | sed -e 's/^X-l//'`
 472                     ;;
 473                   *.la)
 474                     dnl Handle this in the next round. Throw away the .la's
 475                     dnl directory; it is already contained in a preceding -L
 476                     dnl option.
 477                     names_next_round="$names_next_round "`echo "X$dep" | sed -e 's,^X.*/,,' -e 's,^lib,,' -e 's,\.la$,,'`
 478                     ;;
 479                   *)
 480                     dnl Most likely an immediate library name.
 481                     LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$dep"
 482                     LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }$dep"
 483                     ;;
 484                 esac
 485               done
 486             fi
 487           else
 488             dnl Didn't find the library; assume it is in the system directories
 489             dnl known to the linker and runtime loader. (All the system
 490             dnl directories known to the linker should also be known to the
 491             dnl runtime loader, otherwise the system is severely misconfigured.)
 492             LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }-l$name"
 493             LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-l$name"
 494           fi
 495         fi
 496       fi
 497     done
 498   done
 499   if test "X$rpathdirs" != "X"; then
 500     if test -n "$hardcode_libdir_separator"; then
 501       dnl Weird platform: only the last -rpath option counts, the user must
 502       dnl pass all path elements in one option. We can arrange that for a
 503       dnl single library, but not when more than one $LIBNAMEs are used.
 504       alldirs=
 505       for found_dir in $rpathdirs; do
 506         alldirs="${alldirs}${alldirs:+$hardcode_libdir_separator}$found_dir"
 507       done
 508       dnl Note: hardcode_libdir_flag_spec uses $libdir and $wl.
 509       acl_save_libdir="$libdir"
 510       libdir="$alldirs"
 511       eval flag=\"$hardcode_libdir_flag_spec\"
 512       libdir="$acl_save_libdir"
 513       LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$flag"
 514     else
 515       dnl The -rpath options are cumulative.
 516       for found_dir in $rpathdirs; do
 517         acl_save_libdir="$libdir"
 518         libdir="$found_dir"
 519         eval flag=\"$hardcode_libdir_flag_spec\"
 520         libdir="$acl_save_libdir"
 521         LIB[]NAME="${LIB[]NAME}${LIB[]NAME:+ }$flag"
 522       done
 523     fi
 524   fi
 525   if test "X$ltrpathdirs" != "X"; then
 526     dnl When using libtool, the option that works for both libraries and
 527     dnl executables is -R. The -R options are cumulative.
 528     for found_dir in $ltrpathdirs; do
 529       LTLIB[]NAME="${LTLIB[]NAME}${LTLIB[]NAME:+ }-R$found_dir"
 530     done
 531   fi
 532 ])
 533
 534 dnl AC_LIB_APPENDTOVAR(VAR, CONTENTS) appends the elements of CONTENTS to VAR,
 535 dnl unless already present in VAR.
 536 dnl Works only for CPPFLAGS, not for LIB* variables because that sometimes
 537 dnl contains two or three consecutive elements that belong together.
 538 AC_DEFUN([AC_LIB_APPENDTOVAR],
 539 [
 540   for element in [$2]; do
 541     haveit=
 542     for x in $[$1]; do
 543       AC_LIB_WITH_FINAL_PREFIX([eval x=\"$x\"])
 544       if test "X$x" = "X$element"; then
 545         haveit=yes
 546         break
 547       fi
 548     done
 549     if test -z "$haveit"; then
 550       [$1]="${[$1]}${[$1]:+ }$element"
 551     fi
 552   done
 553 ])