Update autogen.sh

autogen.sh

@@ -1,5 +1,55 @@
 #! /bin/sh
 
+args=$(getopt bfos "$@")
+if [ $? -ne 0 ]; then
+  echo "Usage: autogen.sh [-b] [-f] [-o] [-s] [--]"
+  echo
+  echo ">   -b: do not update the system detection scripts"
+  echo ">   -f: force the recreation of all autoconf scripts"
+  echo ">   -o: overwrite/downgrade system detection scripts"
+  echo ">   -s: setup an environment for developers"
+  exit 2
+fi
+
+force=false
+update_config=true
+overwrite_config=false
+dev_setup=false
+
+eval set -- "$args"
+
+while [ $# -ne 0 ]; do
+  case $1 in
+  -b)
+    update_config=false
+    ;;
+  -f)
+    force=true
+    ;;
+  -o)
+    overwrite_config=true
+    ;;
+  -s)
+    dev_setup=true
+    ;;
+  --)
+    shift
+    break
+    ;;
+  esac
+  shift
+done
+
+if [ -s configure ]; then
+  if [ "$force" != true ]; then
+    echo "autoconf scripts already exist." >&2
+    exit 0
+  fi
+elif [ "$dev_setup" != true ]; then
+  echo "A development environment was not created."
+  exit 0
+fi
+
 if glibtoolize --version >/dev/null 2>&1; then
   LIBTOOLIZE='glibtoolize'
 else
@@ -26,6 +76,14 @@ command -v automake >/dev/null 2>&1 || {
   exit 1
 }
 
+if [ "$overwrite_config" = false ]; then
+  if [ -f build-aux/config.guess ]; then
+    mv build-aux/config.guess build-aux/config.guess.stable
+  fi
+  if [ -f build-aux/config.sub ]; then
+    mv build-aux/config.sub build-aux/config.sub.stable
+  fi
+fi
 if autoreconf --version >/dev/null 2>&1; then
   autoreconf -ivf
 else
@@ -34,8 +92,16 @@ else
     automake --add-missing --force-missing --include-deps &&
     autoconf
 fi
+if [ "$overwrite_config" = false ]; then
+  if [ -f build-aux/config.guess.stable ]; then
+    mv build-aux/config.guess.stable build-aux/config.guess
+  fi
+  if [ -f build-aux/config.sub.stable ]; then
+    mv build-aux/config.sub.stable build-aux/config.sub
+  fi
+fi
 
-[ -z "$DO_NOT_UPDATE_CONFIG_SCRIPTS" ] &&
+[ "$update_config" = true ] && [ -z "$DO_NOT_UPDATE_CONFIG_SCRIPTS" ] &&
   command -v curl >/dev/null 2>&1 && {
   echo "Downloading config.guess and config.sub..."