Add --disable-rpath switch to avoid hardcoded path

Author: lgbaldoni

configure.ac

@@ -4,6 +4,18 @@ AM_INIT_AUTOMAKE([-Wall -Werror foreign subdir-objects tar-pax])
 m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 LT_INIT
 
+# Check if we should disable rpath.
+#
+# For advanced users: In certain configurations, the rpath attributes
+# added by libtool cause problems as rpath will be preferred over
+# LD_LIBRARY_PATH. This does not seem to be a problem with
+# clang. When using --disable-rpath you will likely need to set
+# LD_LIBRARY_PATH if you are using libraries in non-system locations.
+# YMMV.
+#
+
+DISABLE_RPATH
+
 AC_PROG_CXX
 AC_LANG(C++)
 

m4/disable-rpath.m4

@@ -0,0 +1,27 @@
+dnl file      : m4/disable-rpath.m4
+dnl author    : Boris Kolpackov <[email protected]>
+dnl copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+dnl license   : GNU GPL v2; see accompanying LICENSE file
+dnl
+AC_DEFUN([DISABLE_RPATH],[
+
+AC_MSG_CHECKING([whether to use rpath])
+AC_ARG_ENABLE(
+  [rpath],
+  [AC_HELP_STRING([--disable-rpath], [patch libtool to not use rpath])],
+  [libtool_rpath="$enable_rpath"],
+  [libtool_rpath="yes"])
+AC_MSG_RESULT($libtool_rpath)
+
+# Patch libtool to not use rpath if requested.
+#
+AC_CONFIG_COMMANDS(
+  [libtool-rpath-patch],
+  [if test "$libtool_use_rpath" = "no"; then
+     sed < libtool > libtool-2 's/^hardcode_libdir_flag_spec.*$'/'hardcode_libdir_flag_spec=" -D__LIBTOOL_NO_RPATH__ "/'
+     mv libtool-2 libtool
+     chmod 755 libtool
+  fi],
+  [libtool_use_rpath=$libtool_rpath])
+])dnl
+