autotools: Use package flags to configure libpcap

Change-Id: Icd64014b597a8e60d2aff9d180c441c6ffccff26
Reviewed-on: https://code.wireshark.org/review/23329
Reviewed-by: João Valverde <j@v6e.pt>

1 files changed, 73 insertions, 65 deletions

diff --git a/acinclude.m4 b/acinclude.m4
index 79064539c9..a5d9642364 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -131,6 +131,9 @@ AC_DEFUN([AC_WIRESHARK_PCAP_BREAKLOOP_TRY_LINK],
 #
 AC_DEFUN([AC_WIRESHARK_PCAP_CHECK],
 [
+	AC_WIRESHARK_PUSH_FLAGS
+	ws_ac_save_LIBS="$LIBS"
+
 	if test -z "$pcap_dir"
 	then
 	  # Pcap header checks
@@ -174,7 +177,17 @@ AC_DEFUN([AC_WIRESHARK_PCAP_CHECK],
 	    # Found it, and it's usable; use it to get the include flags
 	    # for libpcap.
 	    #
-	    CPPFLAGS="$CPPFLAGS `\"$PCAP_CONFIG\" --cflags`"
+	    PCAP_CFLAGS=`\"$PCAP_CONFIG\" --cflags`
+	    #
+	    # We have pcap-config; we assume that means we have libpcap
+	    # installed and that pcap-config will tell us whatever
+	    # libraries libpcap needs.
+	    #
+	    if test x$enable_static = xyes; then
+	      PCAP_LIBS="`\"$PCAP_CONFIG\" --libs --static`"
+	    else
+	      PCAP_LIBS="`\"$PCAP_CONFIG\" --libs`"
+	    fi
 	  else
 	    #
 	    # Didn't find it; we have to look for libpcap ourselves.
@@ -196,7 +209,7 @@ AC_DEFUN([AC_WIRESHARK_PCAP_CHECK],
 	    do
 	      if test -d $pcap_dir ; then
 		if test x$pcap_dir != x/usr/include -a x$pcap_dir != x/usr/local/include ; then
-		    CPPFLAGS="$CPPFLAGS -I$pcap_dir"
+		    PCAP_CFLAGS="-I$pcap_dir"
 		fi
 		found_pcap_dir=" $found_pcap_dir -I$pcap_dir"
 		break
@@ -222,85 +235,79 @@ AC_DEFUN([AC_WIRESHARK_PCAP_CHECK],
 	  # and/or linker will search that other directory before it
 	  # searches the specified directory.
 	  #
-	  CPPFLAGS="$CPPFLAGS -I$pcap_dir/include"
-	  AC_WIRESHARK_ADD_DASH_L(LDFLAGS, $pcap_dir/lib)
+	  PCAP_CFLAGS="-I$pcap_dir/include"
+	  #
+	  # XXX - This doesn't use AC_WIRESHARK_ADD_DASH_L
+	  #
+	  PCAP_LIBS="-L$pcap_dir/lib -lpcap"
 	fi
 
+	CFLAGS="$PCAP_CFLAGS $CFLAGS"
+	LIBS="$PCAP_LIBS $LIBS"
+
 	# Pcap header check
-	AC_CHECK_HEADER(pcap.h,,
-	    AC_MSG_ERROR([[Header file pcap.h not found; if you installed libpcap
+	AC_CHECK_HEADER(pcap.h,
+	  [
+	      AC_DEFINE(HAVE_LIBPCAP, 1, [Define to use libpcap library])
+	  ],
+	  [
+	      AC_MSG_ERROR([[Header file pcap.h not found; if you installed libpcap
 from source, did you also do \"make install-incl\", and if you installed a
 binary package of libpcap, is there also a developer's package of libpcap,
-and did you also install that package?]]))
+and did you also install that package?]])
+	  ])
 
-	if test -n "$PCAP_CONFIG" ; then
-	  #
-	  # We have pcap-config; we assume that means we have libpcap
-	  # installed and that pcap-config will tell us whatever
-	  # libraries libpcap needs.
-	  #
-	  if test x$enable_static = xyes; then
-	    PCAP_LIBS="`\"$PCAP_CONFIG\" --libs --static`"
-	  else
-	    PCAP_LIBS="`\"$PCAP_CONFIG\" --libs`"
-	  fi
-	  AC_DEFINE(HAVE_LIBPCAP, 1, [Define to use libpcap library])
-	else
-	  #
-	  # Check to see if we find "pcap_open_live" in "-lpcap".
-	  # Also check for various additional libraries that libpcap might
-	  # require.
-	  #
-	  AC_CHECK_LIB(pcap, pcap_open_live,
-	    [
-	      PCAP_LIBS=-lpcap
-	      AC_DEFINE(HAVE_LIBPCAP, 1, [Define to use libpcap library])
-	    ], [
-	      ac_wireshark_extras_found=no
-	      ac_save_LIBS="$LIBS"
-	      for extras in "-lcfg -lodm" "-lpfring"
-	      do
-		AC_MSG_CHECKING([for pcap_open_live in -lpcap with $extras])
-		LIBS="-lpcap $extras $ac_save_LIBS"
-		#
-		# XXX - can't we use AC_CHECK_LIB here?
-		#
-		AC_TRY_LINK(
-		    [
+	#
+	# Check to see if we find "pcap_open_live" in "-lpcap".
+	# Also check for various additional libraries that libpcap might
+	# require.
+	#
+	AC_CHECK_LIB(pcap, pcap_open_live,
+	  [
+	  ],
+	  [
+	    ac_wireshark_extras_found=no
+	    ac_save_LIBS="$LIBS"
+	    for extras in "-lcfg -lodm" "-lpfring"
+	    do
+	      AC_MSG_CHECKING([for pcap_open_live in -lpcap with $extras])
+	      LIBS="-lpcap $extras $ac_save_LIBS"
+	      #
+	      # XXX - can't we use AC_CHECK_LIB here?
+	      #
+	      AC_TRY_LINK(
+		[
 #	include <pcap.h>
-		    ],
-		    [
+		],
+		[
 	pcap_open_live(NULL, 0, 0, 0, NULL);
-		    ],
-		    [
-			ac_wireshark_extras_found=yes
-			AC_MSG_RESULT([yes])
-			PCAP_LIBS="-lpcap $extras"
-			AC_DEFINE(HAVE_LIBPCAP, 1, [Define to use libpcap library])
-		    ],
-		    [
-			AC_MSG_RESULT([no])
-		    ])
+		],
+		[
+		  ac_wireshark_extras_found=yes
+		  AC_MSG_RESULT([yes])
+		  PCAP_LIBS="$PCAP_LIBS $extras"
+		],
+		[
+		  AC_MSG_RESULT([no])
+		])
 		if test x$ac_wireshark_extras_found = xyes
 		then
-		    break
+		  break
 		fi
-	      done
-	      if test x$ac_wireshark_extras_found = xno
-	      then
-		AC_MSG_ERROR([Can't link with library libpcap.])
-	      fi
-	      LIBS=$ac_save_LIBS
-	    ])
-	fi
+	    done
+	    if test x$ac_wireshark_extras_found = xno
+	    then
+	      AC_MSG_ERROR([Can't link with library libpcap.])
+	    fi
+	    LIBS=$ac_save_LIBS
+	  ])
+	AC_SUBST(PCAP_CFLAGS)
 	AC_SUBST(PCAP_LIBS)
 
 	#
 	# Check whether various variables and functions are defined by
 	# libpcap.
 	#
-	ac_save_LIBS="$LIBS"
-	LIBS="$PCAP_LIBS $LIBS"
 	AC_CHECK_FUNCS(pcap_open_dead pcap_freecode)
 	#
 	# pcap_breakloop may be present in the library but not declared
@@ -413,7 +420,8 @@ install a newer version of the header file.])
 	  AC_CHECK_FUNCS(bpf_image pcap_set_tstamp_precision pcap_set_tstamp_type)
 	fi
 
-	LIBS="$ac_save_LIBS"
+	AC_WIRESHARK_POP_FLAGS
+	LIBS="$ws_ac_save_LIBS"
 ])
 
 AC_DEFUN([AC_WIRESHARK_PCAP_REMOTE_CHECK],