Merge commit '559eb2308b4d616590aba34bb8f4dd7f12ae4587'
[sliver-openvswitch.git] / 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([$KSRC/include/linux/types.h], [__wsum],
266                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
267
268   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_replace4])
269   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_unfold])
270
271   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [NLA_NUL_STRING])
272   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_get_be16])
273   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be16])
274   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be32])
275   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_be64])
276   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
277
278   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
279                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
280
281   OVS_GREP_IFELSE([$KSRC/include/linux/percpu.h], [this_cpu_ptr])
282
283   OVS_GREP_IFELSE([$KSRC/include/linux/openvswitch.h], [openvswitch_handle_frame_hook],
284                   [OVS_DEFINE([HAVE_RHEL_OVS_HOOK])])
285
286   OVS_CHECK_LOG2_H
287
288   if cmp -s datapath/linux/kcompat.h.new \
289             datapath/linux/kcompat.h >/dev/null 2>&1; then
290     rm datapath/linux/kcompat.h.new
291   else
292     mv datapath/linux/kcompat.h.new datapath/linux/kcompat.h
293   fi
294 ])
295
296 dnl Checks for net/if_packet.h.
297 AC_DEFUN([OVS_CHECK_IF_PACKET],
298   [AC_CHECK_HEADER([net/if_packet.h],
299                    [HAVE_IF_PACKET=yes],
300                    [HAVE_IF_PACKET=no])
301    AM_CONDITIONAL([HAVE_IF_PACKET], [test "$HAVE_IF_PACKET" = yes])
302    if test "$HAVE_IF_PACKET" = yes; then
303       AC_DEFINE([HAVE_IF_PACKET], [1],
304                 [Define to 1 if net/if_packet.h is available.])
305    fi])
306
307 dnl Checks for net/if_dl.h.
308 dnl
309 dnl (We use this as a proxy for checking whether we're building on FreeBSD.)
310 AC_DEFUN([OVS_CHECK_IF_DL],
311   [AC_CHECK_HEADER([net/if_dl.h],
312                    [HAVE_IF_DL=yes],
313                    [HAVE_IF_DL=no])
314    AM_CONDITIONAL([HAVE_IF_DL], [test "$HAVE_IF_DL" = yes])
315    if test "$HAVE_IF_DL" = yes; then
316       AC_DEFINE([HAVE_IF_DL], [1],
317                 [Define to 1 if net/if_dl.h is available.])
318
319       # On FreeBSD we use libpcap to access network devices.
320       AC_SEARCH_LIBS([pcap_open_live], [pcap])
321    fi])
322
323 dnl Checks for buggy strtok_r.
324 dnl
325 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
326 dnl with optimization that can cause segfaults:
327 dnl
328 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
329 AC_DEFUN([OVS_CHECK_STRTOK_R],
330   [AC_CACHE_CHECK(
331      [whether strtok_r macro segfaults on some inputs],
332      [ovs_cv_strtok_r_bug],
333      [AC_RUN_IFELSE(
334         [AC_LANG_PROGRAM([#include <stdio.h>
335                           #include <string.h>
336                          ],
337                          [[char string[] = ":::";
338                            char *save_ptr = (char *) 0xc0ffee;
339                            char *token1, *token2;
340                            token1 = strtok_r(string, ":", &save_ptr);
341                            token2 = strtok_r(NULL, ":", &save_ptr);
342                            freopen ("/dev/null", "w", stdout);
343                            printf ("%s %s\n", token1, token2);
344                            return 0;
345                           ]])],
346         [ovs_cv_strtok_r_bug=no],
347         [ovs_cv_strtok_r_bug=yes],
348         [ovs_cv_strtok_r_bug=yes])])
349    if test $ovs_cv_strtok_r_bug = yes; then
350      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
351                [Define if strtok_r macro segfaults on some inputs])
352    fi
353 ])
354
355 dnl ----------------------------------------------------------------------
356 dnl These macros are from GNU PSPP, with the following original license:
357 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
358 dnl This file is free software; the Free Software Foundation
359 dnl gives unlimited permission to copy and/or distribute it,
360 dnl with or without modifications, as long as this notice is preserved.
361
362 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
363 dnl Check whether the given C compiler OPTION is accepted.
364 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
365 AC_DEFUN([OVS_CHECK_CC_OPTION],
366 [
367   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-], [_])])dnl
368   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name], 
369     [ovs_save_CFLAGS="$CFLAGS"
370      CFLAGS="$CFLAGS $1"
371      AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,)], [ovs_cv_name[]=yes], [ovs_cv_name[]=no])
372      CFLAGS="$ovs_save_CFLAGS"])
373   if test $ovs_cv_name = yes; then
374     m4_if([$2], [], [:], [$2])
375   else
376     m4_if([$3], [], [:], [$3])
377   fi
378 ])
379
380 dnl OVS_ENABLE_OPTION([OPTION])
381 dnl Check whether the given C compiler OPTION is accepted.
382 dnl If so, add it to WARNING_FLAGS.
383 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
384 AC_DEFUN([OVS_ENABLE_OPTION], 
385   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
386    AC_SUBST([WARNING_FLAGS])])
387
388 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
389 dnl Check whether the given C compiler OPTION is accepted.
390 dnl If so, enable the given Automake CONDITIONAL.
391
392 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
393 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
394   [OVS_CHECK_CC_OPTION(
395     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
396    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
397 dnl ----------------------------------------------------------------------
398
399 dnl Check for too-old XenServer.
400 AC_DEFUN([OVS_CHECK_XENSERVER_VERSION],
401   [AC_CACHE_CHECK([XenServer release], [ovs_cv_xsversion],
402     [if test -e /etc/redhat-release; then
403        ovs_cv_xsversion=`sed -n 's/^XenServer DDK release \([[^-]]*\)-.*/\1/p' /etc/redhat-release`
404      fi
405      if test -z "$ovs_cv_xsversion"; then
406        ovs_cv_xsversion=none
407      fi])
408   case $ovs_cv_xsversion in
409     none)
410       ;;
411
412     [[1-9]][[0-9]]* |                    dnl XenServer 10 or later
413     [[6-9]]* |                           dnl XenServer 6 or later
414     5.[[7-9]]* |                         dnl XenServer 5.7 or later
415     5.6.[[1-9]][[0-9]][[0-9]][[0-9]]* |  dnl XenServer 5.6.1000 or later
416     5.6.[[2-9]][[0-9]][[0-9]]* |         dnl XenServer 5.6.200 or later
417     5.6.1[[0-9]][[0-9]])                 dnl Xenserver 5.6.100 or later
418       ;;
419
420     *)
421       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.)])
422       ;;
423   esac])
424
425 dnl OVS_MAKE_HAS_IF([if-true], [if-false])
426 dnl
427 dnl Checks whether make has the GNU make $(if condition,then,else) extension.
428 dnl Runs 'if-true' if so, 'if-false' otherwise.
429 AC_DEFUN([OVS_CHECK_MAKE_IF],
430   [AC_CACHE_CHECK(
431      [whether ${MAKE-make} has GNU make \$(if) extension],
432      [ovs_cv_gnu_make_if],
433      [cat <<'EOF' > conftest.mk
434 conftest.out:
435         echo $(if x,y,z) > conftest.out
436 .PHONY: all
437 EOF
438       rm -f conftest.out
439       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} -f conftest.mk all:"]) >&AS_MESSAGE_LOG_FD 2>&1
440       ${MAKE-make} -f conftest.mk conftest.out >&AS_MESSAGE_LOG_FD 2>&1
441       AS_ECHO(["$as_me:$LINENO: conftest.out contains:"]) >&AS_MESSAGE_LOG_FD 2>&1
442       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
443       result=`cat conftest.out`
444       rm -f conftest.mk conftest.out
445       if test "X$result" = "Xy"; then
446         ovs_cv_gnu_make_if=yes
447       else
448         ovs_cv_gnu_make_if=no
449       fi])])
450
451 dnl OVS_CHECK_GNU_MAKE
452 dnl
453 dnl Checks whether make is GNU make (because Linux kernel Makefiles
454 dnl only work with GNU make).
455 AC_DEFUN([OVS_CHECK_GNU_MAKE],
456   [AC_CACHE_CHECK(
457      [whether ${MAKE-make} is GNU make],
458      [ovs_cv_gnu_make],
459      [rm -f conftest.out
460       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} --version:"]) >&AS_MESSAGE_LOG_FD 2>&1
461       ${MAKE-make} --version >conftest.out 2>&1
462       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
463       result=`cat conftest.out`
464       rm -f conftest.mk conftest.out
465
466       case $result in # (
467         GNU*) ovs_cv_gnu_make=yes ;; # (
468         *) ovs_cv_gnu_make=no ;;
469       esac])
470    AM_CONDITIONAL([GNU_MAKE], [test $ovs_cv_gnu_make = yes])])
471
472 dnl OVS_CHECK_SPARSE_TARGET
473 dnl
474 dnl The "cgcc" script from "sparse" isn't very good at detecting the
475 dnl target for which the code is being built.  This helps it out.
476 AC_DEFUN([OVS_CHECK_SPARSE_TARGET],
477   [AC_CACHE_CHECK(
478     [target hint for cgcc],
479     [ac_cv_sparse_target],
480     [AS_CASE([`$CC -dumpmachine 2>/dev/null`],
481        [i?86-* | athlon-*], [ac_cv_sparse_target=x86],
482        [x86_64-*], [ac_cv_sparse_target=x86_64],
483        [ac_cv_sparse_target=other])])
484    AS_CASE([$ac_cv_sparse_target],
485      [x86], [SPARSEFLAGS= CGCCFLAGS=-target=i86],
486      [x86_64], [SPARSEFLAGS=-m64 CGCCFLAGS=-target=x86_64],
487      [SPARSEFLAGS= CGCCFLAGS=])
488    AC_SUBST([SPARSEFLAGS])
489    AC_SUBST([CGCCFLAGS])])
490
491 dnl OVS_SPARSE_EXTRA_INCLUDES
492 dnl
493 dnl The cgcc script from "sparse" does not search gcc's default
494 dnl search path. Get the default search path from GCC and pass
495 dnl them to sparse.
496 AC_DEFUN([OVS_SPARSE_EXTRA_INCLUDES],
497     AC_SUBST([SPARSE_EXTRA_INCLUDES],
498            [`$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 ' ' `] ))
499
500 dnl OVS_ENABLE_SPARSE
501 AC_DEFUN([OVS_ENABLE_SPARSE],
502   [AC_REQUIRE([OVS_CHECK_SPARSE_TARGET])
503    AC_REQUIRE([OVS_CHECK_MAKE_IF])
504    AC_REQUIRE([OVS_SPARSE_EXTRA_INCLUDES])
505    : ${SPARSE=sparse}
506    AC_SUBST([SPARSE])
507    AC_CONFIG_COMMANDS_PRE(
508      [if test $ovs_cv_gnu_make_if = yes; then
509         CC='$(if $(C),REAL_CC="'"$CC"'" CHECK="$(SPARSE) -I $(top_srcdir)/include/sparse $(SPARSEFLAGS) $(SPARSE_EXTRA_INCLUDES) " cgcc $(CGCCFLAGS),'"$CC"')'
510       fi])])