diff --git a/llvm/autoconf/configure.ac b/llvm/autoconf/configure.ac
index c8732b5dfdc8b46602cd99ed0238995a9f35e7e5..e8c00a476f258f33c6137e9db393f610846eda97 100644
--- a/llvm/autoconf/configure.ac
+++ b/llvm/autoconf/configure.ac
@@ -297,6 +297,11 @@ AC_LIBTOOL_DLOPEN
 AC_LIB_LTDL
 AC_PROG_LIBTOOL
 
+if test "$lt_cv_dlopen_self" = "yes" ; then
+  AC_DEFINE([CAN_DLOPEN_SELF],[1],
+              [Define if dlopen(0) will open the symbols of the program])
+fi
+
 dnl Check if we know how to tell etags we are using C++:
 etags_version=`$ETAGS --version 2>&1`
 case "$etags_version" in
@@ -465,7 +470,7 @@ AC_CHECK_FUNC(mprotect,,
 
 if test "$ac_cv_func_mmap_fixed_mapped" = "no"
 then
-  AC_MSG_WARN([mmap() required but not found])
+  AC_MSG_WARN([mmap() of a fixed address required but not supported])
 fi
 if test "$ac_cv_func_mmap_file" = "no"
 then
diff --git a/llvm/configure b/llvm/configure
index 592e0d982f85ab2c61e687f711db2e25f6a64de4..69e95560cd4bc373c54ce4c3ad794cc59f05211d 100755
--- a/llvm/configure
+++ b/llvm/configure
@@ -5514,7 +5514,7 @@ fi
 if test x"${ac_cv_path_tclsh}" = x ; then
   echo "$as_me:$LINENO: result: none" >&5
 echo "${ECHO_T}none" >&6
-  for ac_prog in tclsh8.4 tclsh8.4.8 tclsh8.4.7 tclsh8.4.6 tclsh8.4.5 tclsh8.4.4 tclsh8.4.3 tclsh8.4.2 tclsh8.4.1 tclsh8.4.0 tclsh8.3 tclsh8.3.5 tclsh8.3.4 tclsh8.3.3 .tclsh8.3.2 tclsh8.3.1 tclsh8.3.0 tclsh
+  for ac_prog in tclsh8.4 tclsh8.4.8 tclsh8.4.7 tclsh8.4.6 tclsh8.4.5 tclsh8.4.4 tclsh8.4.3 tclsh8.4.2 tclsh8.4.1 tclsh8.4.0 tclsh8.3 tclsh8.3.5 tclsh8.3.4 tclsh8.3.3 tclsh8.3.2 tclsh8.3.1 tclsh8.3.0 tclsh
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
 set dummy $ac_prog; ac_word=$2
@@ -24588,6 +24588,14 @@ LIBTOOL='$(SHELL) $(top_builddir)/mklib'
 
 
 
+
+if test "$lt_cv_dlopen_self" = "yes" ; then
+
+cat >>confdefs.h <<\_ACEOF
+#define CAN_DLOPEN_SELF 1
+_ACEOF
+
+fi
 
 etags_version=`$ETAGS --version 2>&1`
 case "$etags_version" in
@@ -29852,7 +29860,7 @@ echo $ECHO_N "checking if /dev/zero is needed for mmap... $ECHO_C" >&6
 if test "${ac_cv_need_dev_zero_for_mmap+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
-  if test "$llvm_cv_os_type" == "Interix" ; then
+  if test "$llvm_cv_os_type" = "Interix" ; then
    ac_cv_need_dev_zero_for_mmap=yes
  else
    ac_cv_need_dev_zero_for_mmap=no
@@ -29969,8 +29977,8 @@ fi
 
 if test "$ac_cv_func_mmap_fixed_mapped" = "no"
 then
-  { echo "$as_me:$LINENO: WARNING: mmap() required but not found" >&5
-echo "$as_me: WARNING: mmap() required but not found" >&2;}
+  { echo "$as_me:$LINENO: WARNING: mmap() of a fixed address required but not supported" >&5
+echo "$as_me: WARNING: mmap() of a fixed address required but not supported" >&2;}
 fi
 if test "$ac_cv_func_mmap_file" = "no"
 then
diff --git a/llvm/include/llvm/Config/config.h.in b/llvm/include/llvm/Config/config.h.in
index 372901d164147dfbddfe1b39744d5828ea135a66..f3f8129a4e7b123e91999da9a5ce99a908d3f6fb 100644
--- a/llvm/include/llvm/Config/config.h.in
+++ b/llvm/include/llvm/Config/config.h.in
@@ -1,5 +1,8 @@
 /* include/llvm/Config/config.h.in.  Generated from autoconf/configure.ac by autoheader.  */
 
+/* Define if dlopen(0) will open the symbols of the program */
+#undef CAN_DLOPEN_SELF
+
 /* Define to one of `_getb67', `GETB67', `getb67' for Cray-2 and Cray-YMP
    systems. This function is required for `alloca.c' support on those systems.
    */