Merged r2204 and r2205 from trunk.

jhalfs

@@ -27,6 +27,11 @@ Options:
                                 jhalfs produces will be in the directory
                                 DIR/jhalfs. Default is \"/mnt/lfs\".
 
+  --rebuild                     clean the build directory before to perfom
+                                any other task. The directory is cleaned
+                                only if it was populated by a previous
+                                jhalfs run.
+
   -P, --get-packages            download the packages and patches. This
                                 assumes that the server declared in the 
                                 jhalfs.conf file has the proper packages
@@ -113,6 +118,33 @@ HEADER="# This file is automatically generated by jhalfs
 ###################################
 
 
+#----------------------------#
+clean_builddir() {
+#----------------------------#
+  # Test if the clean must be done.
+  if [ "$CLEAN" = "1" ] ; then
+    # Test to make sure we're running the clean as root
+    if [ "$UID" != "0" ] ; then
+      echo "You must be logged in as root to clean the build directory."
+      exit 1
+    fi
+    # Test to make sure that the build directory was populated by jhalfs
+    if [ ! -d $JHALFSDIR ] || [ ! -d $BUILDDIR/sources ] ; then
+      echo "Look like $BUILDDIR was not populated by a previous jhalfs run."
+      exit 1
+    else
+      # Clean the build directory
+      echo -ne "Cleaning $BUILDDIR...\n"
+      rm -rf $BUILDDIR/{bin,boot,dev,etc,home,lib,media,mnt,opt,proc,root,sbin,srv,sys,tmp,tools,usr,var}
+      echo -ne "Cleaning $JHALFSDIR...\n"
+      rm -rf $JHALFSDIR/{0*,1*,envars,sources-dir,commands,logs,Makefile,dump-lfs-scripts.xsl,functions,packages,patches}
+      echo -ne "Cleaning remainig extracted sources in $BUILDDIR/sources...\n"
+      rm -rf `find $BUILDDIR/sources/* -maxdepth 0 -type d`
+      echo -ne "done\n"
+    fi
+  fi
+}
+
 #----------------------------#
 get_book() {
 #----------------------------#
@@ -962,6 +994,8 @@ while test $# -gt 0 ; do
       MKFILE=$JHALFSDIR/Makefile
       ;;
 
+    --rebuild )	  CLEAN=1 ;;
+
     --download-client | -D )
       test $# = 1 && eval "$exit_missing_arg"
       shift
@@ -1050,14 +1084,23 @@ while test $# -gt 0 ; do
   shift
 done
 
-# If $BUILDDIR have subdirectories like tools/ or bin/, stop the run
-# and notify the user about that. This also prevents setting "-d /"
-# by mistake.
+# Prevents setting "-d /" by mistake. 
 
-if [ -d $BUILDDIR/tools -o -d $BUILDDIR/bin ] ; then
+if [ $BUILDDIR = / ] ; then
+  echo -ne "\nThe root directory can't be used to build LFS.\n\n"
+  exit 1
+fi
+
+# If $BUILDDIR have subdirectories like tools/ or bin/, stop the run
+# and notify the user about that. 
+
+if [ -d $BUILDDIR/tools -o -d $BUILDDIR/bin ] && [ -z $CLEAN ] ; then
   eval "$no_empty_builddir"
 fi
 
+# If requested, clean the build directory
+clean_builddir
+
 # Find the download client to use, if not already specified.
 
 if [ -z $DL ] ; then