Merge branch 'master' of git://openvswitch.org/openvswitch
[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([$KSRC/include/linux/netdevice.h], [dev_get_by_index_rcu])
227
228   OVS_GREP_IFELSE([$KSRC/include/linux/rcupdate.h], [rcu_read_lock_held], [],
229                   [OVS_GREP_IFELSE([$KSRC/include/linux/rtnetlink.h],
230                                    [rcu_read_lock_held])])
231   
232   # Check for the proto_data_valid member in struct sk_buff.  The [^@]
233   # is necessary because some versions of this header remove the
234   # member but retain the kerneldoc comment that describes it (which
235   # starts with @).  The brackets must be doubled because of m4
236   # quoting rules.
237   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [[[^@]]proto_data_valid],
238                   [OVS_DEFINE([HAVE_PROTO_DATA_VALID])])
239   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [raw],
240                   [OVS_DEFINE([HAVE_MAC_RAW])])
241   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_dst(],
242                   [OVS_DEFINE([HAVE_SKB_DST_ACCESSOR_FUNCS])])
243   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], 
244                   [skb_copy_from_linear_data_offset])
245   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h],
246                   [skb_reset_tail_pointer])
247   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_cow_head])
248   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_transport_header],
249                   [OVS_DEFINE([HAVE_SKBUFF_HEADER_HELPERS])])
250   OVS_GREP_IFELSE([$KSRC/include/linux/icmpv6.h], [icmp6_hdr],
251                   [OVS_DEFINE([HAVE_ICMP6_HDR])])
252   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_warn_if_lro],
253                   [OVS_DEFINE([HAVE_SKB_WARN_LRO])])
254   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [consume_skb])
255   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_frag_page])
256   OVS_GREP_IFELSE([$KSRC/include/linux/skbuff.h], [skb_reset_mac_len])
257
258   OVS_GREP_IFELSE([$KSRC/include/linux/string.h], [kmemdup], [],
259                   [OVS_GREP_IFELSE([$KSRC/include/linux/slab.h], [kmemdup])])
260
261   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [bool],
262                   [OVS_DEFINE([HAVE_BOOL_TYPE])])
263   OVS_GREP_IFELSE([$KSRC/include/linux/types.h], [__wsum],
264                   [OVS_DEFINE([HAVE_CSUM_TYPES])])
265
266   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_replace4])
267   OVS_GREP_IFELSE([$KSRC/include/net/checksum.h], [csum_unfold])
268
269   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [NLA_NUL_STRING])
270   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_get_be16])
271   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
272
273   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
274                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
275
276   OVS_CHECK_LOG2_H
277
278   if cmp -s datapath/linux/kcompat.h.new \
279             datapath/linux/kcompat.h >/dev/null 2>&1; then
280     rm datapath/linux/kcompat.h.new
281   else
282     mv datapath/linux/kcompat.h.new datapath/linux/kcompat.h
283   fi
284 ])
285
286 dnl Checks for net/if_packet.h.
287 AC_DEFUN([OVS_CHECK_IF_PACKET],
288   [AC_CHECK_HEADER([net/if_packet.h],
289                    [HAVE_IF_PACKET=yes],
290                    [HAVE_IF_PACKET=no])
291    AM_CONDITIONAL([HAVE_IF_PACKET], [test "$HAVE_IF_PACKET" = yes])
292    if test "$HAVE_IF_PACKET" = yes; then
293       AC_DEFINE([HAVE_IF_PACKET], [1],
294                 [Define to 1 if net/if_packet.h is available.])
295    fi])
296
297 dnl Checks for net/if_dl.h.
298 dnl
299 dnl (We use this as a proxy for checking whether we're building on FreeBSD.)
300 AC_DEFUN([OVS_CHECK_IF_DL],
301   [AC_CHECK_HEADER([net/if_dl.h],
302                    [HAVE_IF_DL=yes],
303                    [HAVE_IF_DL=no])
304    AM_CONDITIONAL([HAVE_IF_DL], [test "$HAVE_IF_DL" = yes])
305    if test "$HAVE_IF_DL" = yes; then
306       AC_DEFINE([HAVE_IF_DL], [1],
307                 [Define to 1 if net/if_dl.h is available.])
308
309       # On FreeBSD we use libpcap to access network devices.
310       AC_SEARCH_LIBS([pcap_open_live], [pcap])
311    fi])
312
313 dnl Checks for buggy strtok_r.
314 dnl
315 dnl Some versions of glibc 2.7 has a bug in strtok_r when compiling
316 dnl with optimization that can cause segfaults:
317 dnl
318 dnl http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
319 AC_DEFUN([OVS_CHECK_STRTOK_R],
320   [AC_CACHE_CHECK(
321      [whether strtok_r macro segfaults on some inputs],
322      [ovs_cv_strtok_r_bug],
323      [AC_RUN_IFELSE(
324         [AC_LANG_PROGRAM([#include <stdio.h>
325                           #include <string.h>
326                          ],
327                          [[char string[] = ":::";
328                            char *save_ptr = (char *) 0xc0ffee;
329                            char *token1, *token2;
330                            token1 = strtok_r(string, ":", &save_ptr);
331                            token2 = strtok_r(NULL, ":", &save_ptr);
332                            freopen ("/dev/null", "w", stdout);
333                            printf ("%s %s\n", token1, token2);
334                            return 0;
335                           ]])],
336         [ovs_cv_strtok_r_bug=no],
337         [ovs_cv_strtok_r_bug=yes],
338         [ovs_cv_strtok_r_bug=yes])])
339    if test $ovs_cv_strtok_r_bug = yes; then
340      AC_DEFINE([HAVE_STRTOK_R_BUG], [1],
341                [Define if strtok_r macro segfaults on some inputs])
342    fi
343 ])
344
345 dnl ----------------------------------------------------------------------
346 dnl These macros are from GNU PSPP, with the following original license:
347 dnl Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
348 dnl This file is free software; the Free Software Foundation
349 dnl gives unlimited permission to copy and/or distribute it,
350 dnl with or without modifications, as long as this notice is preserved.
351
352 dnl OVS_CHECK_CC_OPTION([OPTION], [ACTION-IF-ACCEPTED], [ACTION-IF-REJECTED])
353 dnl Check whether the given C compiler OPTION is accepted.
354 dnl If so, execute ACTION-IF-ACCEPTED, otherwise ACTION-IF-REJECTED.
355 AC_DEFUN([OVS_CHECK_CC_OPTION],
356 [
357   m4_define([ovs_cv_name], [ovs_cv_[]m4_translit([$1], [-], [_])])dnl
358   AC_CACHE_CHECK([whether $CC accepts $1], [ovs_cv_name], 
359     [ovs_save_CFLAGS="$CFLAGS"
360      CFLAGS="$CFLAGS $1"
361      AC_COMPILE_IFELSE([AC_LANG_PROGRAM(,)], [ovs_cv_name[]=yes], [ovs_cv_name[]=no])
362      CFLAGS="$ovs_save_CFLAGS"])
363   if test $ovs_cv_name = yes; then
364     m4_if([$2], [], [:], [$2])
365   else
366     m4_if([$3], [], [:], [$3])
367   fi
368 ])
369
370 dnl OVS_ENABLE_OPTION([OPTION])
371 dnl Check whether the given C compiler OPTION is accepted.
372 dnl If so, add it to WARNING_FLAGS.
373 dnl Example: OVS_ENABLE_OPTION([-Wdeclaration-after-statement])
374 AC_DEFUN([OVS_ENABLE_OPTION], 
375   [OVS_CHECK_CC_OPTION([$1], [WARNING_FLAGS="$WARNING_FLAGS $1"])
376    AC_SUBST([WARNING_FLAGS])])
377
378 dnl OVS_CONDITIONAL_CC_OPTION([OPTION], [CONDITIONAL])
379 dnl Check whether the given C compiler OPTION is accepted.
380 dnl If so, enable the given Automake CONDITIONAL.
381
382 dnl Example: OVS_CONDITIONAL_CC_OPTION([-Wno-unused], [HAVE_WNO_UNUSED])
383 AC_DEFUN([OVS_CONDITIONAL_CC_OPTION],
384   [OVS_CHECK_CC_OPTION(
385     [$1], [ovs_have_cc_option=yes], [ovs_have_cc_option=no])
386    AM_CONDITIONAL([$2], [test $ovs_have_cc_option = yes])])
387 dnl ----------------------------------------------------------------------
388
389 dnl Check for too-old XenServer.
390 AC_DEFUN([OVS_CHECK_XENSERVER_VERSION],
391   [AC_CACHE_CHECK([XenServer release], [ovs_cv_xsversion],
392     [if test -e /etc/redhat-release; then
393        ovs_cv_xsversion=`sed -n 's/^XenServer DDK release \([[^-]]*\)-.*/\1/p' /etc/redhat-release`
394      fi
395      if test -z "$ovs_cv_xsversion"; then
396        ovs_cv_xsversion=none
397      fi])
398   case $ovs_cv_xsversion in
399     none)
400       ;;
401
402     [[1-9]][[0-9]]* |                    dnl XenServer 10 or later
403     [[6-9]]* |                           dnl XenServer 6 or later
404     5.[[7-9]]* |                         dnl XenServer 5.7 or later
405     5.6.[[1-9]][[0-9]][[0-9]][[0-9]]* |  dnl XenServer 5.6.1000 or later
406     5.6.[[2-9]][[0-9]][[0-9]]* |         dnl XenServer 5.6.200 or later
407     5.6.1[[0-9]][[0-9]])                 dnl Xenserver 5.6.100 or later
408       ;;
409
410     *)
411       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.)])
412       ;;
413   esac])
414
415 dnl OVS_MAKE_HAS_IF([if-true], [if-false])
416 dnl
417 dnl Checks whether make has the GNU make $(if condition,then,else) extension.
418 dnl Runs 'if-true' if so, 'if-false' otherwise.
419 AC_DEFUN([OVS_CHECK_MAKE_IF],
420   [AC_CACHE_CHECK(
421      [whether ${MAKE-make} has GNU make \$(if) extension],
422      [ovs_cv_gnu_make_if],
423      [cat <<'EOF' > conftest.mk
424 conftest.out:
425         echo $(if x,y,z) > conftest.out
426 .PHONY: all
427 EOF
428       rm -f conftest.out
429       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} -f conftest.mk all:"]) >&AS_MESSAGE_LOG_FD 2>&1
430       ${MAKE-make} -f conftest.mk conftest.out >&AS_MESSAGE_LOG_FD 2>&1
431       AS_ECHO(["$as_me:$LINENO: conftest.out contains:"]) >&AS_MESSAGE_LOG_FD 2>&1
432       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
433       result=`cat conftest.out`
434       rm -f conftest.mk conftest.out
435       if test "X$result" = "Xy"; then
436         ovs_cv_gnu_make_if=yes
437       else
438         ovs_cv_gnu_make_if=no
439       fi])])
440
441 dnl OVS_CHECK_GNU_MAKE
442 dnl
443 dnl Checks whether make is GNU make (because Linux kernel Makefiles
444 dnl only work with GNU make).
445 AC_DEFUN([OVS_CHECK_GNU_MAKE],
446   [AC_CACHE_CHECK(
447      [whether ${MAKE-make} is GNU make],
448      [ovs_cv_gnu_make],
449      [rm -f conftest.out
450       AS_ECHO(["$as_me:$LINENO: invoking ${MAKE-make} --version:"]) >&AS_MESSAGE_LOG_FD 2>&1
451       ${MAKE-make} --version >conftest.out 2>&1
452       cat conftest.out >&AS_MESSAGE_LOG_FD 2>&1
453       result=`cat conftest.out`
454       rm -f conftest.mk conftest.out
455
456       case $result in # (
457         GNU*) ovs_cv_gnu_make=yes ;; # (
458         *) ovs_cv_gnu_make=no ;;
459       esac])
460    AM_CONDITIONAL([GNU_MAKE], [test $ovs_cv_gnu_make = yes])])
461
462 dnl OVS_CHECK_SPARSE_TARGET
463 dnl
464 dnl The "cgcc" script from "sparse" isn't very good at detecting the
465 dnl target for which the code is being built.  This helps it out.
466 AC_DEFUN([OVS_CHECK_SPARSE_TARGET],
467   [AC_CACHE_CHECK(
468     [target hint for cgcc],
469     [ac_cv_sparse_target],
470     [AS_CASE([`$CC -dumpmachine 2>/dev/null`],
471        [i?86-* | athlon-*], [ac_cv_sparse_target=x86],
472        [x86_64-*], [ac_cv_sparse_target=x86_64],
473        [ac_cv_sparse_target=other])])
474    AS_CASE([$ac_cv_sparse_target],
475      [x86], [SPARSEFLAGS= CGCCFLAGS=-target=i86],
476      [x86_64], [SPARSEFLAGS=-m64 CGCCFLAGS=-target=x86_64],
477      [SPARSEFLAGS= CGCCFLAGS=])
478    AC_SUBST([SPARSEFLAGS])
479    AC_SUBST([CGCCFLAGS])])
480
481 dnl OVS_ENABLE_SPARSE
482 AC_DEFUN([OVS_ENABLE_SPARSE],
483   [AC_REQUIRE([OVS_CHECK_SPARSE_TARGET])
484    AC_REQUIRE([OVS_CHECK_MAKE_IF])
485    : ${SPARSE=sparse}
486    AC_SUBST([SPARSE])
487    AC_CONFIG_COMMANDS_PRE(
488      [if test $ovs_cv_gnu_make_if = yes; then
489         CC='$(if $(C),REAL_CC="'"$CC"'" CHECK="$(SPARSE) -I $(top_srcdir)/include/sparse $(SPARSEFLAGS)" cgcc $(CGCCFLAGS),'"$CC"')'
490       fi])])