--- a/ChangeLog	Mon Jul 11 11:29:40 2005 +0000
+++ b/ChangeLog	Mon Jul 11 11:37:09 2005 +0000
@@ -1,3 +1,10 @@
+2005-07-09  Bruno Haible  <bruno@clisp.org>
+
+	* gnulib-tool (func_usage): Document option --avoid.
+	(Command line options): Handle --avoid.
+	(func_acceptable): New function.
+	(func_modules_transitive_closure): Use it.
+
 2005-07-11  Bruno Haible  <bruno@clisp.org>
 
 	* MODULES.html.sh: Use shortcut URLs to the www.opengroup.org site.

--- a/gnulib-tool	Mon Jul 11 11:29:40 2005 +0000
+++ b/gnulib-tool	Mon Jul 11 11:37:09 2005 +0000
@@ -22,7 +22,7 @@
 
 progname=$0
 package=gnulib
-cvsdatestamp='$Date: 2005-07-05 07:14:00 $'
+cvsdatestamp='$Date: 2005-07-11 11:37:09 $'
 last_checkin_date=`echo "$cvsdatestamp" | sed -e 's,^\$[D]ate: ,,'`
 version=`echo "$last_checkin_date" | sed -e 's/ .*$//' -e 's,/,-,g'`
 
@@ -90,6 +90,9 @@
                             placed (default \"m4\"), for --import.
       --aux-dir=DIRECTORY   Directory relative --dir where auxiliary build
                             tools are placed (default \".\"), for --import.
+      --avoid=MODULE        Avoid including the given MODULE. Useful if you
+                            have code that provides equivalent functionality.
+                            This option can be repeated.
       --lgpl                Abort if modules aren't available under the LGPL.
                             Also modify license template from GPL to LGPL.
       --libtool             Use libtool rules, for --import.
@@ -181,8 +184,9 @@
 # - sourcebase      from --source-base
 # - m4base          from --m4-base
 # - auxdir          from --aux-dir
+# - avoidlist       list of modules to avoid, from --avoid
+# - lgpl            true if --lgpl was given, blank otherwise
 # - libtool         true if --libtool was given, blank otherwise
-# - lgpl            true if --lgpl was given, blank otherwise
 # - do_changelog    false if --no-changelog was given, : otherwise
 # - dry_run         true if --dry-run was given, blank otherwise
 {
@@ -193,12 +197,12 @@
   sourcebase=
   m4base=
   auxdir=
+  avoidlist=
+  lgpl=
   libtool=
-  lgpl=
   do_changelog=:
   dry_run=
   symbolic=
-  lgpl=
 
   supplied_opts="$@"
 
@@ -277,12 +281,22 @@
       --aux-dir=* )
         auxdir=`echo "X$1" | sed -e 's/^X--aux-dir=//'`
         shift ;;
-      --libtool )
-        libtool=true
+      --avoid )
+        shift
+        if test $# = 0; then
+          func_fatal_error "missing argument for --avoid"
+        fi
+        avoidlist="$avoidlist $1"
+        shift ;;
+      --avoid=* )
+        avoidlist="$avoidlist "`echo "X$1" | sed -e 's/^X--avoid=//'`
         shift ;;
       --lgpl )
         lgpl=true
         shift ;;
+      --libtool )
+        libtool=true
+        shift ;;
       --no-changelog | --no-changelo | --no-changel | --no-change | --no-chang | --no-chan | --no-cha | --no-ch | --no-c )
         do_changelog=false
         shift ;;
@@ -429,9 +443,24 @@
   sed -n -e "/^Maintainer$sed_extract_prog" < "$gnulib_dir/modules/$1"
 }
 
+# func_acceptable module
+# tests whether a module is acceptable.
+# Input:
+# - avoidlist       list of modules to avoid
+func_acceptable ()
+{
+  for avoid in $avoidlist; do
+    if test "$avoid" = "$1"; then
+      return 1
+    fi
+  done
+  return 0
+}
+
 # func_modules_transitive_closure
 # Input:
 # - modules         list of specified modules
+# - avoidlist       list of modules to avoid
 # Output:
 # - modules         list of modules, including dependencies
 func_modules_transitive_closure ()
@@ -441,12 +470,19 @@
     for module in $modules; do
       func_verify_module
       if test -n "$module"; then
-        # Duplicate dependenies are harmless, but Jim wants a warning.
+        # Duplicate dependencies are harmless, but Jim wants a warning.
         duplicated_deps=`func_get_dependencies $module | sort | uniq -d`
         if test -n "$duplicated_deps"; then
           echo "warning: module $module has duplicated dependencies: "`echo $duplicated_deps` 1>&2
         fi
-        xmodules="$xmodules $module "`func_get_dependencies $module`
+        if func_acceptable $module; then
+          xmodules="$xmodules $module"
+          for depmodule in `func_get_dependencies $module`; do
+            if func_acceptable $depmodule; then
+              xmodules="$xmodules $depmodule"
+            fi
+          done
+        fi
       fi
     done
     xmodules=`for m in $xmodules; do echo $m; done | sort | uniq`
@@ -554,8 +590,9 @@
 # - libname         library name
 # - sourcebase      directory relative to destdir where to place source code
 # - m4base          directory relative to destdir where to place *.m4 macros
+# - avoidlist       list of modules to avoid, from --avoid
+# - lgpl            true if library's license shall be LGPL, blank otherwise
 # - libtool         true if libtool will be used, blank otherwise
-# - lgpl            true if library's license shall be LGPL, blank otherwise
 # - dry_run         true if actions shall only be printed, blank otherwise
 # - symbolic        true if files should be symlinked, copied otherwise
 # - supplied_opts   all options passed to gnulib-tool