Replace "--enable-zlib" with "--with-zlib", and have it take an optional

"=DIR" argument to specify the directory in subdirectories of which
zlib's headers and libraries can be found.

svn path=/trunk/; revision=5115

3 files changed, 173 insertions, 17 deletions

diff --git a/wiretap/acconfig.h b/wiretap/acconfig.h
index e9c52e450d..7f318a2d77 100644
--- a/wiretap/acconfig.h
+++ b/wiretap/acconfig.h
@@ -1,6 +1,6 @@
 /* acconfig.h
  *
- * $Id: acconfig.h,v 1.6 2001/11/13 23:55:42 gram Exp $
+ * $Id: acconfig.h,v 1.7 2002/04/08 01:34:39 guy Exp $
  *
  * Wiretap Library
  * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
@@ -24,3 +24,5 @@
 #undef PACKAGE
 
 #undef VERSION
+  
+#undef HAVE_LIBZ
diff --git a/wiretap/acinclude.m4 b/wiretap/acinclude.m4
index d30874b19e..df4cd6a020 100644
--- a/wiretap/acinclude.m4
+++ b/wiretap/acinclude.m4
@@ -2,10 +2,29 @@ dnl Macros that test for specific features.
 dnl This file is part of the Autoconf packaging for Ethereal.
 dnl Copyright (C) 1998-2000 by Gerald Combs.
 dnl
-dnl $Id: acinclude.m4,v 1.13 2002/02/06 09:58:30 guy Exp $
+dnl $Id: acinclude.m4,v 1.14 2002/04/08 01:34:39 guy Exp $
 dnl
 
 #
+# AC_WIRETAP_ADD_DASH_L
+#
+# Add to the variable specified as the first argument a "-L" flag for the
+# directory specified as the second argument, and, on Solaris, add a
+# "-R" flag for it as well.
+#
+# XXX - IRIX, and other OSes, may require some flag equivalent to
+# "-R" here.
+#
+AC_DEFUN(AC_WIRETAP_ADD_DASH_L,
+[$1="$$1 -L$2"
+case "$host_os" in
+  solaris*)
+    $1="$$1 -R$2"
+  ;;
+esac
+])
+
+#
 # AC_WIRETAP_PCAP_CHECK
 #
 AC_DEFUN(AC_WIRETAP_PCAP_CHECK,
@@ -46,10 +65,10 @@ AC_DEFUN(AC_WIRETAP_PCAP_CHECK,
 	  # the include file search path.
 	  #
 	  # XXX - if there's also a libpcap in a directory that's
-	  # already in CFLAGS, CPPFLAGS, or LDFLAGS, this won't
-	  # make us find the version in the specified directory,
-	  # as the compiler and/or linker will search that other
-	  # directory before it searches the specified directory.
+	  # already in CFLAGS or CPPFLAGS, this won't make us find
+	  # the version in the specified directory, as the compiler
+	  # will search that other directory before it searches the
+	  # specified directory.
 	  #
 	  CFLAGS="$CFLAGS -I$pcap_dir/include"
 	  CPPFLAGS="$CPPFLAGS -I$pcap_dir/include"
@@ -64,9 +83,63 @@ AC_DEFUN(AC_WIRETAP_PCAP_CHECK,
 #
 AC_DEFUN(AC_WIRETAP_ZLIB_CHECK,
 [
-	AC_CHECK_HEADER(zlib.h,,enable_zlib=no)
+	if test "x$zlib_dir" != "x"
+	then
+	  #
+	  # The user specified a directory in which zlib resides,
+	  # so add the "include" subdirectory of that directory to
+	  # the include file search path and the "lib" subdirectory
+	  # of that directory to the library search path.
+	  #
+	  # XXX - if there's also a zlib in a directory that's
+	  # already in CFLAGS, CPPFLAGS, or LDFLAGS, this won't
+	  # make us find the version in the specified directory,
+	  # as the compiler and/or linker will search that other
+	  # directory before it searches the specified directory.
+	  #
+	  wiretap_save_CFLAGS="$CFLAGS"
+	  CFLAGS="$CFLAGS -I$zlib_dir/include"
+	  wiretap_save_CPPLAGS="$CPPLAGS"
+	  CPPFLAGS="$CPPFLAGS -I$zlib_dir/include"
+	  wiretap_save_LIBS="$LIBS"
+	  AC_WIRETAP_ADD_DASH_L(LIBS, $zlib_dir/lib)
+	fi
+
+	#
+	# Make sure we have "zlib.h".  If we don't, it means we probably
+	# don't have zlib, so don't use it.
+	#
+	AC_CHECK_HEADER(zlib.h,,
+	  [
+	    if test "x$zlib_dir" != "x"
+	    then
+	      #
+	      # The user used "--with-zlib=" to specify a directory
+	      # containing zlib, but we didn't find the header file
+	      # there; that either means they didn't specify the
+	      # right directory or are confused about whether zlib
+	      # is, in fact, installed.  Report the error and give up.
+	      #
+	      AC_MSG_ERROR([zlib header not found in directory specified in --with-zlib])
+	    else
+	      if test "x$want_zlib" = "xyes"
+	      then
+		#
+		# The user tried to force us to use the library, but we
+		# couldn't find the header file; report an error.
+		#
+		AC_MSG_ERROR(Header file zlib.h not found.)
+	      else
+		#
+		# We couldn't find the header file; don't use the
+		# library, as it's probably not present.
+		#
+		want_zlib=no
+	      fi
+	    fi
+	  ])
 
-	if test x$enable_zlib != xno
+	if test "x$want_zlib" != "xno"
 	then
 		#
 		# Well, we at least have the zlib header file.
@@ -92,6 +165,69 @@ AC_DEFUN(AC_WIRETAP_ZLIB_CHECK,
 		# versions of zlib without "gzgets()" are likely to have
 		# a broken "gzseek()".
 		#
-		AC_CHECK_LIB(z, gzgets,,enable_zlib=no)
+		AC_CHECK_LIB(z, gzgets,
+		[
+			if test "x$zlib_dir" != "x"
+			then
+				#
+				# Put the "-I" and "-L" flags for zlib at
+				# the beginning of CFLAGS, CPPFLAGS, and
+				# LIBS.
+				#
+				LIBS=""
+				AC_WIRETAP_ADD_DASH_L(LIBS, $zlib_dir/lib)
+				LIBS="$LIBS -lz $wiretap_save_LIBS"
+			else
+				LIBS="-lz $LIBS"
+			fi
+			AC_DEFINE(HAVE_LIBZ)
+		],[
+			if test "x$zlib_dir" != "x"
+			then
+				#
+				# Restore the versions of CFLAGS, CPPFLAGS,
+				# and LIBS before we added the "-with-zlib="
+				# directory, as we didn't actually find
+				# zlib there, or didn't find a zlib that
+				# contains gzgets there.
+				#
+			        CFLAGS="$wiretap_save_CFLAGS"
+				CPPFLAGS="$wiretap_save_CPPLAGS"
+				LIBS="$wiretap_save_LIBS"
+			fi
+			want_zlib=no
+		])
+	fi
+
+	if test "x$want_zlib" != "xno"
+	then
+		#
+		# Well, we at least have the zlib header file and a zlib
+		# with "gzgets()".
+		#
+		# Now check for "gzgets()" in zlib when linking with the
+		# linker flags for GTK+ applications; people often grab
+		# XFree86 source and build and install it on their systems,
+		# and they appear sometimes to misconfigure XFree86 so that,
+		# even on systems with zlib, it assumes there is no zlib,
+		# so the XFree86 build process builds and installs its
+		# own zlib in the X11 library directory.
+		#
+		# The XFree86 zlib is an older version that lacks
+		# "gzgets()", and that's the zlib with which Ethereal
+		# gets linked, so the build of Ethereal fails.
+		#
+		ac_save_CFLAGS="$CFLAGS"
+		ac_save_LIBS="$LIBS"
+		CFLAGS="$CFLAGS $GTK_CFLAGS"
+		LIBS="$GTK_LIBS -lz $LIBS"
+		AC_MSG_CHECKING([for gzgets missing when linking with X11])
+	        AC_TRY_LINK_FUNC(gzgets, AC_MSG_RESULT(no),
+		  [
+		    AC_MSG_RESULT(yes)
+		    AC_MSG_ERROR(old zlib found when linking with X11 - get rid of old zlib.)
+		  ])
+		CFLAGS="$ac_save_CFLAGS"
+		LIBS="$ac_save_LIBS"
 	fi
 ])
diff --git a/wiretap/configure.in b/wiretap/configure.in
index 86345a3154..f4928dfe36 100644
--- a/wiretap/configure.in
+++ b/wiretap/configure.in
@@ -1,4 +1,4 @@
-# $Id: configure.in,v 1.37 2002/03/02 20:41:07 guy Exp $
+# $Id: configure.in,v 1.38 2002/04/08 01:34:39 guy Exp $
 dnl
 dnl Process this file with autoconf 2.13 or later to produce a
 dnl configure script; 2.12 doesn't generate a "configure" script that
@@ -165,16 +165,34 @@ AC_ARG_WITH(pcap,
 AC_WIRETAP_PCAP_CHECK
 
 dnl zlib check
-AC_ARG_ENABLE(zlib,
-[  --enable-zlib           use zlib to read compressed data.  [default=yes]],,enable_zlib=yes)
-
 AC_MSG_CHECKING(whether to use zlib for reading compressed capture files)
-if test "x$enable_zlib" = "xno" ; then
-        AC_MSG_RESULT(no)
+
+AC_ARG_WITH(zlib,
+[  --with-zlib[=DIR]       use zlib (located in directory DIR, if supplied) to read compressed data.  [default=yes, if present]],
+[
+	if test $withval = no
+	then
+		want_zlib=no
+	elif test $withval = yes
+	then
+		want_zlib=yes
+	else
+		want_zlib=yes
+		zlib_dir=$withval
+	fi
+],[
+	#
+	# Use zlib if it's present, otherwise don't.
+	#
+	want_zlib=ifpresent
+	zlib_dir=
+])
+if test "x$want_zlib" = "xno" ; then
+	AC_MSG_RESULT(no)
 else
-        AC_MSG_RESULT(yes)
+	AC_MSG_RESULT(yes)
 	AC_WIRETAP_ZLIB_CHECK
-	if test "x$enable_zlib" = "xno" ; then
+	if test "x$want_zlib" = "xno" ; then
 		AC_MSG_RESULT(zlib not found - disabling compressed capture file support)
 	fi
 fi