Use pkg-config if we can. Clean up some CMake stuff.

If we have pkg-config, *and* it has .pc files for libpcap, use it to get
the C compiler flags and linker flags for libpcap.

find_library() sets a cache variable; when we're looping over libraries,
trying to find their full paths, we really want the variable to act as a
local variable, as we're looking up different libraries, so unset it
after we're finished processing a particular library.

When we're searching for static libraries, save the current value of
CMAKE_FIND_LIBRARY_SUFFIXES, set it to ".a", and then restore it when
we're done.  Don't use cmake_push_check_state() for that, as
CMAKE_FIND_LIBRARY_SUFFIXES is *not* one of the variables that it's
guaranteed to save and restore.

1 files changed, 190 insertions, 41 deletions

diff --git a/configure b/configure
index 16a3ac0b..afd5fb5a 100755
--- a/configure
+++ b/configure
@@ -636,6 +636,7 @@ DEPENDENCY_CFLAG
 AR
 RANLIB
 PCAP_CONFIG
+PKG_CONFIG
 LIBOBJS
 EGREP
 GREP
@@ -5357,9 +5358,156 @@ fi
     if test $using_local_libpcap = no ; then
         #
         # We didn't find a local libpcap.
-        # Look for an installed pcap-config.
+        # Look for an installed pkg-config.
         #
         if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
+set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_PKG_CONFIG="$PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+PKG_CONFIG=$ac_cv_path_PKG_CONFIG
+if test -n "$PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $PKG_CONFIG" >&5
+$as_echo "$PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+fi
+if test -z "$ac_cv_path_PKG_CONFIG"; then
+  ac_pt_PKG_CONFIG=$PKG_CONFIG
+  # Extract the first word of "pkg-config", so it can be a program name with args.
+set dummy pkg-config; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_ac_pt_PKG_CONFIG+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $ac_pt_PKG_CONFIG in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_ac_pt_PKG_CONFIG="$ac_pt_PKG_CONFIG" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_ac_pt_PKG_CONFIG="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  ;;
+esac
+fi
+ac_pt_PKG_CONFIG=$ac_cv_path_ac_pt_PKG_CONFIG
+if test -n "$ac_pt_PKG_CONFIG"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_pt_PKG_CONFIG" >&5
+$as_echo "$ac_pt_PKG_CONFIG" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+  if test "x$ac_pt_PKG_CONFIG" = x; then
+    PKG_CONFIG=""
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    PKG_CONFIG=$ac_pt_PKG_CONFIG
+  fi
+else
+  PKG_CONFIG="$ac_cv_path_PKG_CONFIG"
+fi
+
+        if test -n "$PKG_CONFIG" ; then
+            #
+            # We have it.  Are there .pc files for libpcap?
+            #
+            { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether there are .pc files for libpcap" >&5
+$as_echo_n "checking whether there are .pc files for libpcap... " >&6; }
+            if "$PKG_CONFIG" libpcap --exists ; then
+                #
+                # Yes, so we can use pkg-config to get configuration
+                # information for libpcap.
+                #
+                { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+                pkg_config_usable=yes
+            else
+                #
+                # No, so we can't use pkg-config to get configuration
+                # information for libpcap.
+                #
+                { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+                pkg_config_usable=no
+            fi
+        else
+            #
+            # We don't have it, so we obviously can't use it.
+            #
+            pkg_config_usable=no
+        fi
+        if test "$pkg_config_usable" = "yes" ; then
+            #
+            # Found both - use pkg-config to get the include flags for
+            # libpcap and the flags to link with libpcap.
+            #
+            # Please read section 11.6 "Shell Substitutions"
+            # in the autoconf manual before doing anything
+            # to this that involves quoting.  Especially note
+            # the statement "There is just no portable way to use
+            # double-quoted strings inside double-quoted back-quoted
+            # expressions (pfew!)."
+            #
+            cflags=`"$PKG_CONFIG" libpcap --cflags`
+            V_INCLS="$cflags $V_INCLS"
+            libpcap=`"$PKG_CONFIG" libpcap --libs`
+        else
+            #
+            # No pkg-config
+            # Look for an installed pcap-config.
+            #
+            if test -n "$ac_tool_prefix"; then
   # Extract the first word of "${ac_tool_prefix}pcap-config", so it can be a program name with args.
 set dummy ${ac_tool_prefix}pcap-config; ac_word=$2
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
@@ -5457,26 +5605,26 @@ else
   PCAP_CONFIG="$ac_cv_path_PCAP_CONFIG"
 fi
 
-        if test -n "$PCAP_CONFIG" ; then
-            #
-            # Found - use it to get the include flags for
-            # libpcap and the flags to link with libpcap.
-            #
-            # Please read section 11.6 "Shell Substitutions"
-            # in the autoconf manual before doing anything
-            # to this that involves quoting.  Especially note
-            # the statement "There is just no portable way to use
-            # double-quoted strings inside double-quoted back-quoted
-            # expressions (pfew!)."
-            #
-            cflags=`"$PCAP_CONFIG" --cflags`
-            V_INCLS="$cflags $V_INCLS"
-            libpcap=`"$PCAP_CONFIG" --libs`
-        else
-            #
-            # Not found; look for an installed pcap.
-            #
-            { $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -lpcap" >&5
+            if test -n "$PCAP_CONFIG" ; then
+                #
+                # Found - use it to get the include flags for
+                # libpcap and the flags to link with libpcap.
+                #
+                # Please read section 11.6 "Shell Substitutions"
+                # in the autoconf manual before doing anything
+                # to this that involves quoting.  Especially note
+                # the statement "There is just no portable way to use
+                # double-quoted strings inside double-quoted back-quoted
+                # expressions (pfew!)."
+                #
+                cflags=`"$PCAP_CONFIG" --cflags`
+                V_INCLS="$cflags $V_INCLS"
+                libpcap=`"$PCAP_CONFIG" --libs`
+            else
+                #
+                # Not found; look for an installed pcap.
+                #
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for main in -lpcap" >&5
 $as_echo_n "checking for main in -lpcap... " >&6; }
 if ${ac_cv_lib_pcap_main+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -5510,26 +5658,27 @@ if test "x$ac_cv_lib_pcap_main" = xyes; then :
   libpcap="-lpcap"
 fi
 
-            if test $libpcap = FAIL ; then
-                as_fn_error $? "see the INSTALL doc for more info" "$LINENO" 5
-            fi
-                                                                                                                                                                                                                                                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for extraneous pcap header directories" >&5
+                if test $libpcap = FAIL ; then
+                    as_fn_error $? "see the INSTALL doc for more info" "$LINENO" 5
+                fi
+                                                                                                                                                                                                                                                                                                                                { $as_echo "$as_me:${as_lineno-$LINENO}: checking for extraneous pcap header directories" >&5
 $as_echo_n "checking for extraneous pcap header directories... " >&6; }
-            if test \( ! -r /usr/local/include/pcap.h \) -a \
-                    \( ! -r /usr/include/pcap.h \); then
-                if test -r /usr/local/include/pcap/pcap.h; then
-                    d="/usr/local/include/pcap"
-                elif test -r /usr/include/pcap/pcap.h; then
-                    d="/usr/include/pcap"
+                if test \( ! -r /usr/local/include/pcap.h \) -a \
+                        \( ! -r /usr/include/pcap.h \); then
+                    if test -r /usr/local/include/pcap/pcap.h; then
+                        d="/usr/local/include/pcap"
+                    elif test -r /usr/include/pcap/pcap.h; then
+                        d="/usr/include/pcap"
+                    fi
                 fi
-            fi
-            if test -z "$d" ; then
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
+                if test -z "$d" ; then
+                    { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
 $as_echo "not found" >&6; }
-            else
-                V_INCLS="-I$d $V_INCLS"
-                { $as_echo "$as_me:${as_lineno-$LINENO}: result: found -- -I$d added" >&5
+                else
+                    V_INCLS="-I$d $V_INCLS"
+                    { $as_echo "$as_me:${as_lineno-$LINENO}: result: found -- -I$d added" >&5
 $as_echo "found -- -I$d added" >&6; }
+                fi
             fi
         fi
     else
@@ -5630,11 +5779,11 @@ fi
         fi
     fi
 
-    if test -z "$PCAP_CONFIG"; then
+    if test -z "$PKG_CONFIG" -a -z "$PCAP_CONFIG"; then
         #
-        # We don't have pcap-config; find out any additional link flags
-        # we need.  (If we have pcap-config, we assume it tells us what
-        # we need.)
+        # We don't have pkg-config or pcap-config; find out any additional
+        # link flags we need.  (If we have pkg-config or pcap-config, we
+        # assume it tells us what we need.)
         #
         case "$host_os" in