acinclude.m4

   1 # -*- autoconf -*-
   2
   3 # Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at:
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 dnl OVS_ENABLE_WERROR
  18 AC_DEFUN([OVS_ENABLE_WERROR],
  19   [AC_ARG_ENABLE(
  20      [Werror],
  21      [AC_HELP_STRING([--enable-Werror], [Add -Werror to CFLAGS])],
  22      [], [enable_Werror=no])
  23    AC_CONFIG_COMMANDS_PRE(
  24      [if test "X$enable_Werror" = Xyes; then
  25         CFLAGS="$CFLAGS -Werror"
  26       fi])])
  27
  28 dnl OVS_CHECK_LINUX
  29 dnl
  30 dnl Configure linux kernel source tree
  31 AC_DEFUN([OVS_CHECK_LINUX], [
  32   AC_ARG_WITH([linux],
  33               [AC_HELP_STRING([--with-linux=/path/to/linux],
  34                               [Specify the Linux kernel build directory])])
  35   AC_ARG_WITH([linux-source],
  36               [AC_HELP_STRING([--with-linux-source=/path/to/linux-source],
  37                               [Specify the Linux kernel source directory
  38                                (usually figured out automatically from build
  39                                directory)])])
  40
  41   # Deprecated equivalents to --with-linux, --with-linux-source.
  42   AC_ARG_WITH([l26])
  43   AC_ARG_WITH([l26-source])
  44
  45   if test X"$with_linux" != X; then
  46     KBUILD=$with_linux
  47   elif test X"$with_l26" != X; then
  48     KBUILD=$with_l26
  49     AC_MSG_WARN([--with-l26 is deprecated, please use --with-linux instead])
  50   else
  51     KBUILD=
  52   fi
  53
  54   if test X"$KBUILD" != X; then
  55     if test X"$with_linux_source" != X; then
  56       KSRC=$with_linux_source
  57     elif test X"$with_l26_source" != X; then
  58       KSRC=$with_l26_source
  59       AC_MSG_WARN([--with-l26-source is deprecated, please use --with-linux-source instead])
  60     else
  61       KSRC=
  62     fi
  63   elif test X"$with_linux_source" != X || test X"$with_l26_source" != X; then
  64     AC_MSG_ERROR([Linux source directory may not be specified without Linux build directory])
  65   fi
  66
  67   if test -n "$KBUILD"; then
  68     KBUILD=`eval echo "$KBUILD"`
  69     case $KBUILD in
  70         /*) ;;
  71         *) KBUILD=`pwd`/$KBUILD ;;
  72     esac
  73
  74     # The build directory is what the user provided.
  75     # Make sure that it exists.
  76     AC_MSG_CHECKING([for Linux build directory])
  77     if test -d "$KBUILD"; then
  78         AC_MSG_RESULT([$KBUILD])
  79         AC_SUBST(KBUILD)
  80     else
  81         AC_MSG_RESULT([no])
  82         AC_ERROR([source dir $KBUILD doesn't exist])
  83     fi
  84
  85     # Debian breaks kernel headers into "source" header and "build" headers.
  86     # We want the source headers, but $KBUILD gives us the "build" headers.
  87     # Use heuristics to find the source headers.
  88     AC_MSG_CHECKING([for Linux source directory])
  89     if test -n "$KSRC"; then
  90       KSRC=`eval echo "$KSRC"`
  91       case $KSRC in
  92           /*) ;;
  93           *) KSRC=`pwd`/$KSRC ;;
  94       esac
  95       if test ! -e $KSRC/include/linux/kernel.h; then
  96         AC_MSG_ERROR([$KSRC is not a kernel source directory])
  97       fi
  98     else
  99       KSRC=$KBUILD
 100       if test ! -e $KSRC/include/linux/kernel.h; then
 101         # Debian kernel build Makefiles tend to include a line of the form:
 102         # MAKEARGS := -C /usr/src/linux-headers-3.2.0-1-common O=/usr/src/linux-headers-3.2.0-1-486
 103         # First try to extract the source directory from this line.
 104         KSRC=`sed -n 's/.*-C \([[^ ]]*\).*/\1/p' "$KBUILD"/Makefile`
 105         if test ! -e "$KSRC"/include/linux/kernel.h; then
 106           # Didn't work.  Fall back to name-based heuristics that used to work.
 107           case `echo "$KBUILD" | sed 's,/*$,,'` in # (
 108             */build)
 109               KSRC=`echo "$KBUILD" | sed 's,/build/*$,/source,'`
 110               ;; # (
 111             *)
 112               KSRC=`(cd $KBUILD && pwd -P) | sed 's,-[[^-]]*$,-common,'`
 113               ;;
 114           esac
 115         fi
 116       fi
 117       if test ! -e "$KSRC"/include/linux/kernel.h; then
 118         AC_MSG_ERROR([cannot find source directory (please use --with-linux-source)])
 119       fi
 120     fi
 121     AC_MSG_RESULT([$KSRC])
 122
 123     AC_MSG_CHECKING([for kernel version])
 124     version=`sed -n 's/^VERSION = //p' "$KSRC/Makefile"`
 125     patchlevel=`sed -n 's/^PATCHLEVEL = //p' "$KSRC/Makefile"`
 126     sublevel=`sed -n 's/^SUBLEVEL = //p' "$KSRC/Makefile"`
 127     if test X"$version" = X || test X"$patchlevel" = X; then
 128        AC_ERROR([cannot determine kernel version])
 129     elif test X"$sublevel" = X; then
 130        kversion=$version.$patchlevel
 131     else
 132        kversion=$version.$patchlevel.$sublevel
 133     fi
 134     AC_MSG_RESULT([$kversion])
 135
 136     if test "$version" -ge 3; then
 137        : # Linux 3.x
 138     elif test "$version" = 2 && test "$patchlevel" -ge 6; then
 139        : # Linux 2.6.x
 140     else
 141        if test "$KBUILD" = "$KSRC"; then
 142          AC_ERROR([Linux kernel in $KBUILD is version $kversion, but version 2.6 or later is required])
 143        else
 144          AC_ERROR([Linux kernel in build tree $KBUILD (source tree $KSRC) is version $kversion, but version 2.6 or later is required])
 145        fi
 146     fi
 147     if (test ! -e "$KBUILD"/include/linux/version.h && \
 148         test ! -e "$KBUILD"/include/generated/uapi/linux/version.h)|| \
 149        (test ! -e "$KBUILD"/include/linux/autoconf.h && \
 150         test ! -e "$KBUILD"/include/generated/autoconf.h); then
 151         AC_MSG_ERROR([Linux kernel source in $KBUILD is not configured])
 152     fi
 153     OVS_CHECK_LINUX_COMPAT
 154   fi
 155   AM_CONDITIONAL(LINUX_ENABLED, test -n "$KBUILD")
 156 ])
 157
 158 dnl OVS_GREP_IFELSE(FILE, REGEX, [IF-MATCH], [IF-NO-MATCH])
 159 dnl
 160 dnl Greps FILE for REGEX.  If it matches, runs IF-MATCH, otherwise IF-NO-MATCH.
 161 dnl If IF-MATCH is empty then it defines to OVS_DEFINE(HAVE_<REGEX>), with
 162 dnl <REGEX> translated to uppercase.
 163 AC_DEFUN([OVS_GREP_IFELSE], [
 164   AC_MSG_CHECKING([whether $2 matches in $1])
 165   if test -f $1; then
 166     grep '$2' $1 >/dev/null 2>&1
 167     status=$?
 168     case $status in
 169       0)
 170         AC_MSG_RESULT([yes])
 171         m4_if([$3], [], [OVS_DEFINE([HAVE_]m4_toupper([$2]))], [$3])
 172         ;;
 173       1)
 174         AC_MSG_RESULT([no])
 175         $4
 176         ;;
 177       *)
 178         AC_MSG_ERROR([grep exited with status $status])
 179         ;;
 180     esac
 181   else
 182     AC_MSG_RESULT([file not found])
 183     $4
 184   fi
 185 ])
 186
 187 dnl OVS_DEFINE(NAME)
 188 dnl
 189 dnl Defines NAME to 1 in kcompat.h.
 190 AC_DEFUN([OVS_DEFINE], [
 191   echo '#define $1 1' >> datapath/linux/kcompat.h.new
 192 ])
 193
 194 AC_DEFUN([OVS_CHECK_LOG2_H], [
 195   AC_MSG_CHECKING([for $KSRC/include/linux/log2.h])
 196   if test -e $KSRC/include/linux/log2.h; then
 197     AC_MSG_RESULT([yes])
 198     OVS_DEFINE([HAVE_LOG2_H])
 199   else
 200     AC_MSG_RESULT([no])
 201   fi
 202 ])
 203
 204 dnl OVS_CHECK_LINUX_COMPAT
 205 dnl
 206 dnl Runs various Autoconf checks on the Linux 2.6 kernel source in
 207 dnl the directory in $KBUILD.
 208 AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
 209   rm -f datapath/linux/kcompat.h.new
 210   mkdir -p datapath/linux
 211   : > datapath/linux/kcompat.h.new
 212
 213   OVS_GREP_IFELSE([$KSRC/arch/x86/include/asm/checksum_32.h], [src_err,],
 214                   [OVS_DEFINE([HAVE_CSUM_COPY_DBG])])
 215
 216   OVS_GREP_IFELSE([$KSRC/include/linux/err.h], [ERR_CAST])
 217
 218   OVS_GREP_IFELSE([$KSRC/include/linux/etherdevice.h], [eth_hw_addr_random])
 219
 220   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [vlan_set_encap_proto])
 221
 222   OVS_GREP_IFELSE([$KSRC/include/linux/in.h], [ipv4_is_multicast])
 223
 224   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_disable_lro])
 225   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_stats])
 226   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [dev_get_by_index_rcu])
 227   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [__skb_gso_segment])
 228   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [can_checksum_protocol])
 229
 230   OVS_GREP_IFELSE([$KSRC/include/linux/rcupdate.h], [rcu_read_lock_held], [],
 231                   [OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h],
 232                                    [rcu_read_lock_held])])
 233
 234   # Check for the proto_data_valid member in struct sk_buff.  The [^@]
 235   # is necessary because some versions of this header remove the
 236   # member but retain the kerneldoc comment that describes it (which
 237   # starts with @).  The brackets must be doubled because of m4
 238   # quoting rules.
 239   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
 240                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
 241   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [raw],
 242                   [OVS_DEFINE([HAVE_MAC_RAW])])
 243   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
 244                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
 245   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 246                   [skb_copy_from_linear_data_offset])
 247   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
 248                   [skb_reset_tail_pointer])
 249   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
 250   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_transport_header],
 251                   [OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
 252   OVS_GREP_IFELSE([$KSRC/include/linux/icmpv6.h], [icmp6_hdr],
 253                   [OVS_DEFINE([HAVE_ICMP6_HDR])])
 254   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_warn_if_lro],
 255                   [OVS_DEFINE([HAVE_SKB_WARN_LRO])])
 256   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [consume_skb])
 257   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_frag_page])
 258   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_reset_mac_len])
 259
 260   OVS_GREP_IFELSE([$KSRC/include/linux/string.h], [kmemdup], [],
 261                   [OVS_GREP_IFELSE([$KSRC/include/linux/slab.h], [kmemdup])])
 262
 263   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [bool],
 264                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
 265   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [__wsum],
 266                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
 267   OVS_GREP_IFELSE([$KSRC/include/uapi/linux/types.h], [__wsum],
 268                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
 269
 270   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_replace4])
 271   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_unfold])
 272
 273   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [NLA_NUL_STRING])
 274   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_get_be16])
 275   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be16])
 276   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be32])
 277   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be64])
 278   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
 279
 280   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
 281                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
 282
 283   OVS_GREP_IFELSE([$KSRC/include/linux/percpu.h], [this_cpu_ptr])
 284
 285   OVS_GREP_IFELSE([$KSRC/include/linux/openvswitch.h], [openvswitch_handle_frame_hook],
 286                   [OVS_DEFINE([HAVE_RHEL_OVS_HOOK])])
 287
 288   OVS_CHECK_LOG2_H
 289
 290   if cmp -s datapath/linux/kcompat.h.new \
 291             datapath/linux/kcompat.h >/dev/null 2>&1; then
 292     rm datapath/linux/kcompat.h.new
 293   else
 294     mv datapath/linux/kcompat.h.new datapath/linux/kcompat.h
 295   fi
 296 ])
 297
 298 dnl Checks for net/if_packet.h.
 299 AC_DEFUN([OVS_CHECK_IF_PACKET],
 300   [AC_CHECK_HEADER([net/if_packet.h],
 301                    [HAVE_IF_PACKET=yes],
 302                    [HAVE_IF_PACKET=no])
 303    AM_CONDITIONAL([HAVE_IF_PACKET], [test "$HAVE_IF_PACKET" = yes])
 304    if test "$HAVE_IF_PACKET" = yes; then
 305       AC_DEFINE([HAVE_IF_PACKET], [1],
 306                 [Define to 1 if net/if_packet.h is available.])
 307    fi])
 308
 309 dnl Checks for net/if_dl.h.
 310 dnl
 311 dnl (We use this as a proxy for checking whether we're building on FreeBSD
 312 dnl or NetBSD.)
 313 AC_DEFUN([OVS_CHECK_IF_DL],
 314   [AC_CHECK_HEADER([net/if_dl.h],
 315                    [HAVE_IF_DL=yes],
 316                    [HAVE_IF_DL=no])
 317    AM_CONDITIONAL([HAVE_IF_DL], [test "$HAVE_IF_DL" = yes])
 318    if test "$HAVE_IF_DL" = yes; then
 319       AC_DEFINE([HAVE_IF_DL], [1],
 320                 [Define to 1 if net/if_dl.h is available.])
 321
 322       # On these platforms we use libpcap to access network devices.
 323       AC_SEARCH_LIBS([pcap_open_live], [pcap])
 324    fi])
 325
 326 dnl Checks for buggy strtok_r.
 327 dnl
 328 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
 329 dnl with optimization that can cause segfaults:
 330 dnl
 331 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
 332 AC_DEFUN([OVS_CHECK_STRTOK_R],
 333   [AC_CACHE_CHECK(
 334      [whether strtok_r macro segfaults on some inputs],
 335      [ovs_cv_strtok_r_bug],
 336      [AC_RUN_IFELSE(
 337         [AC_LANG_PROGRAM([#include <stdio.h>
 338                           #include <string.h>
 339                          ],
 340                          [[char string[] = ":::";
 341                            char *save_ptr = (char *) 0xc0ffee;
 342                            char *token1, *token2;
 343                            token1 = strtok_r(string, ":", &save_ptr);
 344                            token2 = strtok_r(NULL, ":", &save_ptr);
 345                            freopen ("/dev/null", "w", stdout);
 346                            printf ("%s %s\n", token1, token2);
 347                            return 0;
 348                           ]])],
 349         [ovs_cv_strtok_r_bug=no],
 350         [ovs_cv_strtok_r_bug=yes],
 351         [ovs_cv_strtok_r_bug=yes])])
 352    if test $ovs_cv_strtok_r_bug = yes; then
 353      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
 354                [Define if strtok_r macro segfaults on some inputs])
 355    fi
 356 ])
 357
 358 dnl ----------------------------------------------------------------------
 359 dnl These macros are from GNU PSPP, with the following original license:
 360 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
 361 dnl This file is free software; the Free Software Foundation
 362 dnl gives unlimited permission to copy and/or distribute it,
 363 dnl with or without modifications, as long as this notice is preserved.
 364
 365 AC_DEFUN([_OVS_CHECK_CC_OPTION], [dnl
 366   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-], [_])])dnl
 367   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name],
 368     [ovs_save_CFLAGS="$CFLAGS"
 369      dnl Include -Werror in the compiler options, because without -Werror
 370      dnl clang's GCC-compatible compiler driver does not return a failure
 371      dnl exit status even though it complains about options it does not
 372      dnl understand.
 373      CFLAGS="$CFLAGS $WERROR $1"
 374      AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,)], [ovs_cv_name[]=yes], [ovs_cv_name[]=no])
 375      CFLAGS="$ovs_save_CFLAGS"])
 376   if test $ovs_cv_name = yes; then
 377     m4_if([$2], [], [:], [$2])
 378   else
 379     m4_if([$3], [], [:], [$3])
 380   fi
 381 ])
 382
 383 dnl OVS_CHECK_WERROR
 384 dnl
 385 dnl Check whether the C compiler accepts -Werror.
 386 dnl Sets $WERROR to "-Werror", if so, and otherwise to the empty string.
 387 AC_DEFUN([OVS_CHECK_WERROR],
 388   [WERROR=
 389    _OVS_CHECK_CC_OPTION([-Werror], [WERROR=-Werror])])
 390
 391 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
 392 dnl Check whether the given C compiler OPTION is accepted.
 393 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
 394 AC_DEFUN([OVS_CHECK_CC_OPTION],
 395   [AC_REQUIRE([OVS_CHECK_WERROR])
 396    _OVS_CHECK_CC_OPTION([$1], [$2], [$3])])
 397
 398 dnl OVS_ENABLE_OPTION([OPTION])
 399 dnl Check whether the given C compiler OPTION is accepted.
 400 dnl If so, add it to WARNING_FLAGS.
 401 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
 402 AC_DEFUN([OVS_ENABLE_OPTION],
 403   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
 404    AC_SUBST([WARNING_FLAGS])])
 405
 406 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
 407 dnl Check whether the given C compiler OPTION is accepted.
 408 dnl If so, enable the given Automake CONDITIONAL.
 409
 410 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
 411 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
 412   [OVS_CHECK_CC_OPTION(
 413     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
 414    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
 415 dnl ----------------------------------------------------------------------
 416
 417 dnl Check for too-old XenServer.
 418 AC_DEFUN([OVS_CHECK_XENSERVER_VERSION],
 419   [AC_CACHE_CHECK([XenServer release], [ovs_cv_xsversion],
 420     [if test -e /etc/redhat-release; then
 421        ovs_cv_xsversion=`sed -n 's/^XenServer DDK release \([[^-]]*\)-.*/\1/p' /etc/redhat-release`
 422      fi
 423      if test -z "$ovs_cv_xsversion"; then
 424        ovs_cv_xsversion=none
 425      fi])
 426   case $ovs_cv_xsversion in
 427     none)
 428       ;;
 429
 430     [[1-9]][[0-9]]* |                    dnl XenServer 10 or later
 431     [[6-9]]* |                           dnl XenServer 6 or later
 432     5.[[7-9]]* |                         dnl XenServer 5.7 or later
 433     5.6.[[1-9]][[0-9]][[0-9]][[0-9]]* |  dnl XenServer 5.6.1000 or later
 434     5.6.[[2-9]][[0-9]][[0-9]]* |         dnl XenServer 5.6.200 or later
 435     5.6.1[[0-9]][[0-9]])                 dnl Xenserver 5.6.100 or later
 436       ;;
 437
 438     *)
 439       AC_MSG_ERROR([This appears to be XenServer $ovs_cv_xsversion, but only XenServer 5.6.100 or later is supported.  (If you are really using a supported version of XenServer, you may override this error message by specifying 'ovs_cv_xsversion=5.6.100' on the "configure" command line.)])
 440       ;;
 441   esac])
 442
 443 dnl OVS_MAKE_HAS_IF([if-true], [if-false])
 444 dnl
 445 dnl Checks whether make has the GNU make $(if condition,then,else) extension.
 446 dnl Runs 'if-true' if so, 'if-false' otherwise.
 447 AC_DEFUN([OVS_CHECK_MAKE_IF],
 448   [AC_CACHE_CHECK(
 449      [whether ${MAKE-make} has GNU make \$(if) extension],
 450      [ovs_cv_gnu_make_if],
 451      [cat <<'EOF' > conftest.mk
 452 conftest.out:
 453         echo $(if x,y,z) > conftest.out
 454 .PHONY: all
 455 EOF
 456       rm -f conftest.out
 457       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} -f conftest.mk all:"]) >&AS_MESSAGE_LOG_FD 2>&1
 458       ${MAKE-make} -f conftest.mk conftest.out >&AS_MESSAGE_LOG_FD 2>&1
 459       AS_ECHO(["$as_me:$LINENO: conftest.out contains:"]) >&AS_MESSAGE_LOG_FD 2>&1
 460       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
 461       result=`cat conftest.out`
 462       rm -f conftest.mk conftest.out
 463       if test "X$result" = "Xy"; then
 464         ovs_cv_gnu_make_if=yes
 465       else
 466         ovs_cv_gnu_make_if=no
 467       fi])])
 468
 469 dnl OVS_CHECK_GNU_MAKE
 470 dnl
 471 dnl Checks whether make is GNU make (because Linux kernel Makefiles
 472 dnl only work with GNU make).
 473 AC_DEFUN([OVS_CHECK_GNU_MAKE],
 474   [AC_CACHE_CHECK(
 475      [whether ${MAKE-make} is GNU make],
 476      [ovs_cv_gnu_make],
 477      [rm -f conftest.out
 478       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} --version:"]) >&AS_MESSAGE_LOG_FD 2>&1
 479       ${MAKE-make} --version >conftest.out 2>&1
 480       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
 481       result=`cat conftest.out`
 482       rm -f conftest.mk conftest.out
 483
 484       case $result in # (
 485         GNU*) ovs_cv_gnu_make=yes ;; # (
 486         *) ovs_cv_gnu_make=no ;;
 487       esac])
 488    AM_CONDITIONAL([GNU_MAKE], [test $ovs_cv_gnu_make = yes])])
 489
 490 dnl OVS_CHECK_SPARSE_TARGET
 491 dnl
 492 dnl The "cgcc" script from "sparse" isn't very good at detecting the
 493 dnl target for which the code is being built.  This helps it out.
 494 AC_DEFUN([OVS_CHECK_SPARSE_TARGET],
 495   [AC_CACHE_CHECK(
 496     [target hint for cgcc],
 497     [ac_cv_sparse_target],
 498     [AS_CASE([`$CC -dumpmachine 2>/dev/null`],
 499        [i?86-* | athlon-*], [ac_cv_sparse_target=x86],
 500        [x86_64-*], [ac_cv_sparse_target=x86_64],
 501        [ac_cv_sparse_target=other])])
 502    AS_CASE([$ac_cv_sparse_target],
 503      [x86], [SPARSEFLAGS= CGCCFLAGS=-target=i86],
 504      [x86_64], [SPARSEFLAGS=-m64 CGCCFLAGS=-target=x86_64],
 505      [SPARSEFLAGS= CGCCFLAGS=])
 506    AC_SUBST([SPARSEFLAGS])
 507    AC_SUBST([CGCCFLAGS])])
 508
 509 dnl OVS_SPARSE_EXTRA_INCLUDES
 510 dnl
 511 dnl The cgcc script from "sparse" does not search gcc's default
 512 dnl search path. Get the default search path from GCC and pass
 513 dnl them to sparse.
 514 AC_DEFUN([OVS_SPARSE_EXTRA_INCLUDES],
 515     AC_SUBST([SPARSE_EXTRA_INCLUDES],
 516            [`$CC -v -E - </dev/null 2>&1 >/dev/null | sed -n -e '/^#include.*search.*starts.*here:/,/^End.*of.*search.*list\./s/^ \(.*\)/-I \1/p' |grep -v /usr/lib | grep -x -v '\-I /usr/include' | tr \\\n ' ' `] ))
 517
 518 dnl OVS_ENABLE_SPARSE
 519 AC_DEFUN([OVS_ENABLE_SPARSE],
 520   [AC_REQUIRE([OVS_CHECK_SPARSE_TARGET])
 521    AC_REQUIRE([OVS_CHECK_MAKE_IF])
 522    AC_REQUIRE([OVS_SPARSE_EXTRA_INCLUDES])
 523    : ${SPARSE=sparse}
 524    AC_SUBST([SPARSE])
 525    AC_CONFIG_COMMANDS_PRE(
 526      [if test $ovs_cv_gnu_make_if = yes; then
 527         CC='$(if $(C),REAL_CC="'"$CC"'" CHECK="$(SPARSE) -I $(top_srcdir)/include/sparse $(SPARSEFLAGS) $(SPARSE_EXTRA_INCLUDES) " cgcc $(CGCCFLAGS),'"$CC"')'
 528       fi])])