download_and_compile.sh: add option --cleanup

This option recursively deletes build and install directories, but
preserves FGData if present (FGData is in
<base_dir>/install/flightgear/fgdata, hence the need to take special
care of it).

There is currently no way to trigger this cleanup routine whithout
pretending to act on at least one component, since "no components
specified" implies "SIMGEAR FGFS DATA". That said, using -pn -dn -rn -cn
with one of the components you already have should be close enough to
"only do the cleanup".

download_and_compile.sh

@@ -193,6 +193,43 @@ function _yes_no_quit_prompt(){
   return $res
 }
 
+# Recursively delete build and install directories, but preserve FGData if
+# present.
+function _cleanup(){
+  if [[ -z "$CBD" || -z "$INSTALL_DIR" || -z "$INSTALL_DIR_FGFS" ]]; then
+    _printLog "${PROGNAME}:" '_cleanup() called while $CBD or $INSTALL_DIR or'
+    _printLog '$INSTALL_DIR_FGFS is empty.'
+    _printLog "\$CBD='$CBD'"
+    _printLog "\$INSTALL_DIR='$INSTALL_DIR'"
+    _printLog "\$INSTALL_DIR_FGFS='$INSTALL_DIR_FGFS'"
+    _printLog 'This is unexpected; please report.'
+    exit 1
+  fi
+
+  local fgdata_backup="$CBD/fgdata.tmp.download_and_compile-cleanup"
+  local -i fgdata_moved=0
+
+  _printLog "Deleting build directories ($CBD/build)..."
+  rm -rf "$CBD/build"
+
+  if [[ -d "$INSTALL_DIR_FGFS/fgdata" ]]; then
+    _printLog "Moving FGData to $fgdata_backup..."
+    mv "$INSTALL_DIR_FGFS/fgdata" "$fgdata_backup"
+    fgdata_moved=1
+  fi
+
+  _printLog "Deleting install directories ($INSTALL_DIR)..."
+  rm -rf "$INSTALL_DIR"
+
+  if [[ $fgdata_moved -eq 1 ]]; then
+    mkdir -p "$INSTALL_DIR_FGFS"
+    _printLog "Moving FGData back to $INSTALL_DIR_FGFS/fgdata..."
+    mv "$fgdata_backup" "$INSTALL_DIR_FGFS/fgdata"
+  fi
+
+  _printLog
+}
+
 function _aptUpdate(){
   local cmd=()
 
@@ -530,6 +567,9 @@ function _usage() {
   echo "  -p y|n        y=install packages using PACKAGE_MANAGER, n=don't                     default=y"
   echo "  -c y|n        y=compile programs, n=don't                                           default=y"
   echo "  -d y|n        y=fetch programs from the Internet (Git, svn, etc.), n=don't          default=y"
+  echo "      --cleanup Remove all build and installation directories. Try this if a"
+  echo '                compilation fails and the "base directory" was not "fresh" when'
+  echo "                you started ${PROGNAME}."
   echo "      --git-clone-default-proto=PROTO                                                 default=https"
   echo "                default protocol to use for 'git clone' (https, git or ssh)"
   echo "      --git-clone-site-params=SITE=PROTOCOL[:USERNAME]"
@@ -599,6 +639,7 @@ declare -a WHATTOBUILD_AVAIL=(
 WHATTOBUILDALL=(SIMGEAR FGFS DATA)
 
 SELECTED_SUITE=next
+CLEANUP="n"
 APT_GET_UPDATE="y"
 DOWNLOAD_PACKAGES="y"
 COMPILE="y"
@@ -694,9 +735,9 @@ if [[ `uname` == 'OpenBSD' ]]; then
     getopt=gnugetopt
 fi
 TEMP=$($getopt -o '+shc:p:a:d:r:j:O:ib:' \
-  --longoptions git-clone-default-proto:,git-clone-site-params:,help,lts \
+  --longoptions cleanup,git-clone-default-proto:,git-clone-site-params:,lts \
   --longoptions package-manager:,sudo:,ignore-intercomponent-deps,compositor \
-  --longoptions component-branch:,non-interactive,version \
+  --longoptions component-branch:,non-interactive,help,version \
   -n "$PROGNAME" -- "$@")
 
 case $? in
@@ -742,6 +783,7 @@ while true; do
     -c) COMPILE="$2"; shift 2 ;;
     -p) DOWNLOAD_PACKAGES="$2"; shift 2 ;;
     -d) DOWNLOAD="$2"; shift 2 ;;
+    --cleanup) CLEANUP="y"; shift ;;
     --git-clone-default-proto)
       proto="${2,,}"            # convert to lowercase
 
@@ -1085,7 +1127,9 @@ fi
 #######################################################
 
 SUB_INSTALL_DIR=install
+FGFS_INSTALL_DIR=flightgear
 INSTALL_DIR="$CBD/$SUB_INSTALL_DIR"
+INSTALL_DIR_FGFS="$INSTALL_DIR/$FGFS_INSTALL_DIR"
 cd "$CBD"
 mkdir -p build install
 
@@ -1115,6 +1159,10 @@ fi
 
 _printLog
 
+if [[ "$CLEANUP" = "y" ]]; then
+  _cleanup
+fi
+
 #######################################################
 # cmake
 #######################################################
@@ -1318,8 +1366,6 @@ fi
 #######################################################
 # FGFS
 #######################################################
-FGFS_INSTALL_DIR=flightgear
-INSTALL_DIR_FGFS="$INSTALL_DIR/$FGFS_INSTALL_DIR"
 cd "$CBD"
 if _elementIn "FGFS" "${WHATTOBUILD[@]}" || \
    _elementIn "DATA" "${WHATTOBUILD[@]}"; then