--- gcc-4.2.1.org/configure
+++ gcc-4.2.1/configure
@@ -436,6 +436,16 @@
   -*) { echo "configure: error: $ac_option: invalid option; use --help to show usage" 1>&2; exit 1; }
     ;;
 
+  *=*)
+    ac_envvar=`expr "x$ac_option" : 'x\([^=]*\)='`
+    # Reject names that are not valid shell variable names.
+    case $ac_envvar in #(
+      '' | [0-9]* | *[!_$as_cr_alnum]* )
+      as_fn_error "invalid variable name: \`$ac_envvar'" ;;
+    esac
+    eval $ac_envvar=\$ac_optarg
+    export $ac_envvar ;;
+
   *)
     if test -n "`echo $ac_option| sed 's/[-a-z0-9.]//g'`"; then
       echo "configure: warning: $ac_option: invalid host type" 1>&2