Provide --enable-cxx11 configure option to enable building with C++11.

For LLVM >= 3.5 explicitly force this to be enabled otherwise we can't
compile against LLVM.

 - Some minor tweaks to the configure logic by me (Daniel Dunbar), to ensure C++
   compiler is tested before these checks run, and to properly restore CXXFLAGS.

4 files changed, 828 insertions, 698 deletions

diff --git a/Makefile.common b/Makefile.common
index e5e3c18a..e6de9f1e 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -30,6 +30,11 @@ endif
 # Needed to build runtime library using clang (gnu89 is the gcc default)
 C.Flags += -std=gnu89
 
+# Build using C++11 if requested
+ifeq ($(KLEE_USE_CXX11),1)
+	CXX.Flags += -std=c++11
+endif
+
 # This is filename that KLEE will look for when trying to load klee-uclibc
 KLEE_UCLIBC_BCA_NAME="klee-uclibc.bca"
 
diff --git a/Makefile.config.in b/Makefile.config.in
index a6dcdcaa..c8e2b57f 100644
--- a/Makefile.config.in
+++ b/Makefile.config.in
@@ -27,6 +27,8 @@ PROJ_OBJ_ROOT := $(subst //,/,@abs_top_builddir@)
 # Set the root directory of this project's install prefix
 PROJ_INSTALL_ROOT := @prefix@
 
+KLEE_USE_CXX11 := @KLEE_USE_CXX11@
+
 STP_ROOT := @STP_ROOT@
 
 STP_NEEDS_BOOST := @STP_NEEDS_BOOST@
diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 18822396..97bd5eb6 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -32,8 +32,9 @@ AH_TOP([#ifndef KLEE_CONFIG_CONFIG_H
 #define KLEE_CONFIG_CONFIG_H])
 AH_BOTTOM([#endif])
 
-dnl FIXME: Make out of tree builds work.
-
+dnl We need to check for the compiler up here to avoid anything else
+dnl starting with a different one.
+AC_PROG_CXX(g++ clang++ )
 AC_LANG([C++])
 
 dnl **************************************************************************
@@ -154,6 +155,36 @@ else
 fi
 AC_SUBST(REQUIRES_RTTI,$requires_rtti)
 
+dnl Provide option to use C++11
+AC_ARG_ENABLE([cxx11],[  --enable-cxx11          Build using C++11], [klee_use_cxx11=1], [klee_use_cxx11=0])
+
+dnl LLVM >= 3.5 requires C++11
+AC_MSG_CHECKING([if LLVM needs C++11])
+if test '(' $llvm_version_major -eq 3 -a $llvm_version_minor -ge 5 ')' -o '(' $llvm_version_major -gt 3 ')' ; then
+  klee_use_cxx11=1
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
+fi
+
+dnl Check if the compiler supports C++11 (this check is taken from LLVM's configure.ac).
+if test X${klee_use_cxx11} = X1; then
+  klee_old_cxxflags="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=c++11"
+  AC_LINK_IFELSE([AC_LANG_SOURCE([[
+#include <atomic>
+std::atomic<float> x(0.0f);
+int main() { return (float)x; }
+]])],
+            [AC_MSG_RESULT([yes])],
+            [AC_MSG_RESULT([no])
+             AC_MSG_ERROR([C++11 not supported])])
+  CXXFLAGS="$klee_old_cxxflags"
+fi
+
+AC_SUBST(KLEE_USE_CXX11,$klee_use_cxx11)
+
+
 AC_ARG_WITH(llvm-build-mode,
   AS_HELP_STRING([--with-llvm-build-mode],
     [LLVM build mode (e.g. Debug or Release, default autodetect)]),,[with_llvm_build_mode=check])
diff --git a/configure b/configure
index 38404d73..ff3b3536 100755
--- a/configure
+++ b/configure
@@ -639,6 +639,13 @@ host_alias
 target_alias
 LLVM_SRC
 LLVM_OBJ
+CXX
+CXXFLAGS
+LDFLAGS
+CPPFLAGS
+ac_ct_CXX
+EXEEXT
+OBJEXT
 build
 build_cpu
 build_vendor
@@ -655,6 +662,7 @@ LLVM_VERSION_MAJOR
 LLVM_VERSION_MINOR
 LLVM_IS_RELEASE
 REQUIRES_RTTI
+KLEE_USE_CXX11
 LLVM_BUILD_MODE
 llvm_gcc
 llvm_gxx
@@ -671,18 +679,11 @@ RUNTIME_DEBUG_SYMBOLS
 RUNTIME_CONFIGURATION
 CC
 CFLAGS
-LDFLAGS
-CPPFLAGS
 ac_ct_CC
-EXEEXT
-OBJEXT
 CPP
 GREP
 EGREP
 HAVE_SELINUX
-CXX
-CXXFLAGS
-ac_ct_CXX
 CXXCPP
 UPSTREAM_STP_LINK_FLAGS
 STP_NEEDS_BOOST
@@ -695,14 +696,14 @@ ac_subst_files=''
       ac_precious_vars='build_alias
 host_alias
 target_alias
-CC
-CFLAGS
-LDFLAGS
-CPPFLAGS
-CPP
 CXX
 CXXFLAGS
+LDFLAGS
+CPPFLAGS
 CCC
+CC
+CFLAGS
+CPP
 CXXCPP'
 
 
@@ -1279,6 +1280,7 @@ if test -n "$ac_init_help"; then
 Optional Features:
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
+  --enable-cxx11          Build using C++11
   --enable-posix-runtime  Enable the POSIX runtime
 
 Optional Packages:
@@ -1303,15 +1305,15 @@ Optional Packages:
   --with-metasmt          Location of metaSMT installation directory
 
 Some influential environment variables:
-  CC          C compiler command
-  CFLAGS      C compiler flags
+  CXX         C++ compiler command
+  CXXFLAGS    C++ compiler flags
   LDFLAGS     linker flags, e.g. -L<lib dir> if you have libraries in a
               nonstandard directory <lib dir>
   CPPFLAGS    C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
+  CC          C compiler command
+  CFLAGS      C compiler flags
   CPP         C preprocessor
-  CXX         C++ compiler command
-  CXXFLAGS    C++ compiler flags
   CXXCPP      C++ preprocessor
 
 Use these variables to override the choices made by `configure' or to help
@@ -1820,6 +1822,676 @@ ac_config_headers="$ac_config_headers include/klee/Config/config.h"
 
 
 
+ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+if test -z "$CXX"; then
+  if test -n "$CCC"; then
+    CXX=$CCC
+  else
+    if test -n "$ac_tool_prefix"; then
+  for ac_prog in g++ clang++
+  do
+    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
+set dummy $ac_tool_prefix$ac_prog; ac_word=$2
+{ echo "$as_me:$LINENO: checking for $ac_word" >&5
+echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6; }
+if test "${ac_cv_prog_CXX+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  if test -n "$CXX"; then
+  ac_cv_prog_CXX="$CXX" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_CXX="$ac_tool_prefix$ac_prog"
+    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+IFS=$as_save_IFS
+
+fi
+fi
+CXX=$ac_cv_prog_CXX
+if test -n "$CXX"; then
+  { echo "$as_me:$LINENO: result: $CXX" >&5
+echo "${ECHO_T}$CXX" >&6; }
+else
+  { echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+fi
+
+
+    test -n "$CXX" && break
+  done
+fi
+if test -z "$CXX"; then
+  ac_ct_CXX=$CXX
+  for ac_prog in g++ clang++
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ echo "$as_me:$LINENO: checking for $ac_word" >&5
+echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6; }
+if test "${ac_cv_prog_ac_ct_CXX+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  if test -n "$ac_ct_CXX"; then
+  ac_cv_prog_ac_ct_CXX="$ac_ct_CXX" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_ac_ct_CXX="$ac_prog"
+    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_CXX=$ac_cv_prog_ac_ct_CXX
+if test -n "$ac_ct_CXX"; then
+  { echo "$as_me:$LINENO: result: $ac_ct_CXX" >&5
+echo "${ECHO_T}$ac_ct_CXX" >&6; }
+else
+  { echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+fi
+
+
+  test -n "$ac_ct_CXX" && break
+done
+
+  if test "x$ac_ct_CXX" = x; then
+    CXX="g++"
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ echo "$as_me:$LINENO: WARNING: In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to autoconf@gnu.org." >&5
+echo "$as_me: WARNING: In the future, Autoconf will not detect cross-tools
+whose name does not start with the host triplet.  If you think this
+configuration is useful to you, please write to autoconf@gnu.org." >&2;}
+ac_tool_warned=yes ;;
+esac
+    CXX=$ac_ct_CXX
+  fi
+fi
+
+  fi
+fi
+# Provide some information about the compiler.
+echo "$as_me:$LINENO: checking for C++ compiler version" >&5
+ac_compiler=`set X $ac_compile; echo $2`
+{ (ac_try="$ac_compiler --version >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compiler --version >&5") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }
+{ (ac_try="$ac_compiler -v >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compiler -v >&5") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }
+{ (ac_try="$ac_compiler -V >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compiler -V >&5") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }
+
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+ac_clean_files_save=$ac_clean_files
+ac_clean_files="$ac_clean_files a.out a.exe b.out"
+# Try to create an executable without -o first, disregard a.out.
+# It will help us diagnose broken compilers, and finding out an intuition
+# of exeext.
+{ echo "$as_me:$LINENO: checking for C++ compiler default output file name" >&5
+echo $ECHO_N "checking for C++ compiler default output file name... $ECHO_C" >&6; }
+ac_link_default=`echo "$ac_link" | sed 's/ -o *conftest[^ ]*//'`
+#
+# List of possible output files, starting from the most likely.
+# The algorithm is not robust to junk in `.', hence go to wildcards (a.*)
+# only as a last resort.  b.out is created by i960 compilers.
+ac_files='a_out.exe a.exe conftest.exe a.out conftest a.* conftest.* b.out'
+#
+# The IRIX 6 linker writes into existing files which may not be
+# executable, retaining their permissions.  Remove them first so a
+# subsequent execution test works.
+ac_rmfiles=
+for ac_file in $ac_files
+do
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.o | *.obj ) ;;
+    * ) ac_rmfiles="$ac_rmfiles $ac_file";;
+  esac
+done
+rm -f $ac_rmfiles
+
+if { (ac_try="$ac_link_default"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link_default") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; then
+  # Autoconf-2.13 could set the ac_cv_exeext variable to `no'.
+# So ignore a value of `no', otherwise this would lead to `EXEEXT = no'
+# in a Makefile.  We should not override ac_cv_exeext if it was cached,
+# so that the user can short-circuit this test for compilers unknown to
+# Autoconf.
+for ac_file in $ac_files
+do
+  test -f "$ac_file" || continue
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.o | *.obj )
+	;;
+    [ab].out )
+	# We found the default executable, but exeext='' is most
+	# certainly right.
+	break;;
+    *.* )
+        if test "${ac_cv_exeext+set}" = set && test "$ac_cv_exeext" != no;
+	then :; else
+	   ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
+	fi
+	# We set ac_cv_exeext here because the later test for it is not
+	# safe: cross compilers may not add the suffix if given an `-o'
+	# argument, so we may need to know it at that point already.
+	# Even if this section looks crufty: it has the advantage of
+	# actually working.
+	break;;
+    * )
+	break;;
+  esac
+done
+test "$ac_cv_exeext" = no && ac_cv_exeext=
+
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { echo "$as_me:$LINENO: error: C++ compiler cannot create executables
+See \`config.log' for more details." >&5
+echo "$as_me: error: C++ compiler cannot create executables
+See \`config.log' for more details." >&2;}
+   { (exit 77); exit 77; }; }
+fi
+
+ac_exeext=$ac_cv_exeext
+{ echo "$as_me:$LINENO: result: $ac_file" >&5
+echo "${ECHO_T}$ac_file" >&6; }
+
+# Check that the compiler produces executables we can run.  If not, either
+# the compiler is broken, or we cross compile.
+{ echo "$as_me:$LINENO: checking whether the C++ compiler works" >&5
+echo $ECHO_N "checking whether the C++ compiler works... $ECHO_C" >&6; }
+# FIXME: These cross compiler hacks should be removed for Autoconf 3.0
+# If not cross compiling, check that we can run a simple program.
+if test "$cross_compiling" != yes; then
+  if { ac_try='./$ac_file'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+    cross_compiling=no
+  else
+    if test "$cross_compiling" = maybe; then
+	cross_compiling=yes
+    else
+	{ { echo "$as_me:$LINENO: error: cannot run C++ compiled programs.
+If you meant to cross compile, use \`--host'.
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot run C++ compiled programs.
+If you meant to cross compile, use \`--host'.
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; }
+    fi
+  fi
+fi
+{ echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+
+rm -f a.out a.exe conftest$ac_cv_exeext b.out
+ac_clean_files=$ac_clean_files_save
+# Check that the compiler produces executables we can run.  If not, either
+# the compiler is broken, or we cross compile.
+{ echo "$as_me:$LINENO: checking whether we are cross compiling" >&5
+echo $ECHO_N "checking whether we are cross compiling... $ECHO_C" >&6; }
+{ echo "$as_me:$LINENO: result: $cross_compiling" >&5
+echo "${ECHO_T}$cross_compiling" >&6; }
+
+{ echo "$as_me:$LINENO: checking for suffix of executables" >&5
+echo $ECHO_N "checking for suffix of executables... $ECHO_C" >&6; }
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; then
+  # If both `conftest.exe' and `conftest' are `present' (well, observable)
+# catch `conftest.exe'.  For instance with Cygwin, `ls conftest' will
+# work properly (i.e., refer to `conftest.exe'), while it won't with
+# `rm'.
+for ac_file in conftest.exe conftest conftest.*; do
+  test -f "$ac_file" || continue
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.o | *.obj ) ;;
+    *.* ) ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
+	  break;;
+    * ) break;;
+  esac
+done
+else
+  { { echo "$as_me:$LINENO: error: cannot compute suffix of executables: cannot compile and link
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot compute suffix of executables: cannot compile and link
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
+rm -f conftest$ac_cv_exeext
+{ echo "$as_me:$LINENO: result: $ac_cv_exeext" >&5
+echo "${ECHO_T}$ac_cv_exeext" >&6; }
+
+rm -f conftest.$ac_ext
+EXEEXT=$ac_cv_exeext
+ac_exeext=$EXEEXT
+{ echo "$as_me:$LINENO: checking for suffix of object files" >&5
+echo $ECHO_N "checking for suffix of object files... $ECHO_C" >&6; }
+if test "${ac_cv_objext+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.o conftest.obj
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; then
+  for ac_file in conftest.o conftest.obj conftest.*; do
+  test -f "$ac_file" || continue;
+  case $ac_file in
+    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf ) ;;
+    *) ac_cv_objext=`expr "$ac_file" : '.*\.\(.*\)'`
+       break;;
+  esac
+done
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { echo "$as_me:$LINENO: error: cannot compute suffix of object files: cannot compile
+See \`config.log' for more details." >&5
+echo "$as_me: error: cannot compute suffix of object files: cannot compile
+See \`config.log' for more details." >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
+rm -f conftest.$ac_cv_objext conftest.$ac_ext
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_objext" >&5
+echo "${ECHO_T}$ac_cv_objext" >&6; }
+OBJEXT=$ac_cv_objext
+ac_objext=$OBJEXT
+{ echo "$as_me:$LINENO: checking whether we are using the GNU C++ compiler" >&5
+echo $ECHO_N "checking whether we are using the GNU C++ compiler... $ECHO_C" >&6; }
+if test "${ac_cv_cxx_compiler_gnu+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+#ifndef __GNUC__
+       choke me
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_compiler_gnu=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_compiler_gnu=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_cv_cxx_compiler_gnu=$ac_compiler_gnu
+
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_cxx_compiler_gnu" >&5
+echo "${ECHO_T}$ac_cv_cxx_compiler_gnu" >&6; }
+GXX=`test $ac_compiler_gnu = yes && echo yes`
+ac_test_CXXFLAGS=${CXXFLAGS+set}
+ac_save_CXXFLAGS=$CXXFLAGS
+{ echo "$as_me:$LINENO: checking whether $CXX accepts -g" >&5
+echo $ECHO_N "checking whether $CXX accepts -g... $ECHO_C" >&6; }
+if test "${ac_cv_prog_cxx_g+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_save_cxx_werror_flag=$ac_cxx_werror_flag
+   ac_cxx_werror_flag=yes
+   ac_cv_prog_cxx_g=no
+   CXXFLAGS="-g"
+   cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_prog_cxx_g=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	CXXFLAGS=""
+      cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  :
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+	 CXXFLAGS="-g"
+	 cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest.$ac_objext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_prog_cxx_g=yes
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+   ac_cxx_werror_flag=$ac_save_cxx_werror_flag
+fi
+{ echo "$as_me:$LINENO: result: $ac_cv_prog_cxx_g" >&5
+echo "${ECHO_T}$ac_cv_prog_cxx_g" >&6; }
+if test "$ac_test_CXXFLAGS" = set; then
+  CXXFLAGS=$ac_save_CXXFLAGS
+elif test $ac_cv_prog_cxx_g = yes; then
+  if test "$GXX" = yes; then
+    CXXFLAGS="-g -O2"
+  else
+    CXXFLAGS="-g"
+  fi
+else
+  if test "$GXX" = yes; then
+    CXXFLAGS="-O2"
+  else
+    CXXFLAGS=
+  fi
+fi
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 ac_ext=cpp
 ac_cpp='$CXXCPP $CPPFLAGS'
@@ -2108,6 +2780,97 @@ fi
 REQUIRES_RTTI=$requires_rtti
 
 
+# Check whether --enable-cxx11 was given.
+if test "${enable_cxx11+set}" = set; then
+  enableval=$enable_cxx11; klee_use_cxx11=1
+else
+  klee_use_cxx11=0
+fi
+
+
+{ echo "$as_me:$LINENO: checking if LLVM needs C++11" >&5
+echo $ECHO_N "checking if LLVM needs C++11... $ECHO_C" >&6; }
+if test '(' $llvm_version_major -eq 3 -a $llvm_version_minor -ge 5 ')' -o '(' $llvm_version_major -gt 3 ')' ; then
+  klee_use_cxx11=1
+  { echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+else
+  { echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+fi
+
+if test X${klee_use_cxx11} = X1; then
+  klee_old_cxxflags="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=c++11"
+
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+#include <atomic>
+std::atomic<float> x(0.0f);
+int main() { return (float)x; }
+
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  { echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6; }
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	{ echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6; }
+             { { echo "$as_me:$LINENO: error: C++11 not supported" >&5
+echo "$as_me: error: C++11 not supported" >&2;}
+   { (exit 1); exit 1; }; }
+fi
+
+rm -f core conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+  CXXFLAGS="$klee_old_cxxflags"
+fi
+
+KLEE_USE_CXX11=$klee_use_cxx11
+
+
+
 
 # Check whether --with-llvm-build-mode was given.
 if test "${with_llvm_build_mode+set}" = set; then
@@ -3013,245 +3776,6 @@ eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
   echo "$as_me:$LINENO: \$? = $ac_status" >&5
   (exit $ac_status); }
 
-cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-ac_clean_files_save=$ac_clean_files
-ac_clean_files="$ac_clean_files a.out a.exe b.out"
-# Try to create an executable without -o first, disregard a.out.
-# It will help us diagnose broken compilers, and finding out an intuition
-# of exeext.
-{ echo "$as_me:$LINENO: checking for C compiler default output file name" >&5
-echo $ECHO_N "checking for C compiler default output file name... $ECHO_C" >&6; }
-ac_link_default=`echo "$ac_link" | sed 's/ -o *conftest[^ ]*//'`
-#
-# List of possible output files, starting from the most likely.
-# The algorithm is not robust to junk in `.', hence go to wildcards (a.*)
-# only as a last resort.  b.out is created by i960 compilers.
-ac_files='a_out.exe a.exe conftest.exe a.out conftest a.* conftest.* b.out'
-#
-# The IRIX 6 linker writes into existing files which may not be
-# executable, retaining their permissions.  Remove them first so a
-# subsequent execution test works.
-ac_rmfiles=
-for ac_file in $ac_files
-do
-  case $ac_file in
-    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.o | *.obj ) ;;
-    * ) ac_rmfiles="$ac_rmfiles $ac_file";;
-  esac
-done
-rm -f $ac_rmfiles
-
-if { (ac_try="$ac_link_default"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_link_default") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; then
-  # Autoconf-2.13 could set the ac_cv_exeext variable to `no'.
-# So ignore a value of `no', otherwise this would lead to `EXEEXT = no'
-# in a Makefile.  We should not override ac_cv_exeext if it was cached,
-# so that the user can short-circuit this test for compilers unknown to
-# Autoconf.
-for ac_file in $ac_files
-do
-  test -f "$ac_file" || continue
-  case $ac_file in
-    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.o | *.obj )
-	;;
-    [ab].out )
-	# We found the default executable, but exeext='' is most
-	# certainly right.
-	break;;
-    *.* )
-        if test "${ac_cv_exeext+set}" = set && test "$ac_cv_exeext" != no;
-	then :; else
-	   ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
-	fi
-	# We set ac_cv_exeext here because the later test for it is not
-	# safe: cross compilers may not add the suffix if given an `-o'
-	# argument, so we may need to know it at that point already.
-	# Even if this section looks crufty: it has the advantage of
-	# actually working.
-	break;;
-    * )
-	break;;
-  esac
-done
-test "$ac_cv_exeext" = no && ac_cv_exeext=
-
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-{ { echo "$as_me:$LINENO: error: C compiler cannot create executables
-See \`config.log' for more details." >&5
-echo "$as_me: error: C compiler cannot create executables
-See \`config.log' for more details." >&2;}
-   { (exit 77); exit 77; }; }
-fi
-
-ac_exeext=$ac_cv_exeext
-{ echo "$as_me:$LINENO: result: $ac_file" >&5
-echo "${ECHO_T}$ac_file" >&6; }
-
-# Check that the compiler produces executables we can run.  If not, either
-# the compiler is broken, or we cross compile.
-{ echo "$as_me:$LINENO: checking whether the C compiler works" >&5
-echo $ECHO_N "checking whether the C compiler works... $ECHO_C" >&6; }
-# FIXME: These cross compiler hacks should be removed for Autoconf 3.0
-# If not cross compiling, check that we can run a simple program.
-if test "$cross_compiling" != yes; then
-  if { ac_try='./$ac_file'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-    cross_compiling=no
-  else
-    if test "$cross_compiling" = maybe; then
-	cross_compiling=yes
-    else
-	{ { echo "$as_me:$LINENO: error: cannot run C compiled programs.
-If you meant to cross compile, use \`--host'.
-See \`config.log' for more details." >&5
-echo "$as_me: error: cannot run C compiled programs.
-If you meant to cross compile, use \`--host'.
-See \`config.log' for more details." >&2;}
-   { (exit 1); exit 1; }; }
-    fi
-  fi
-fi
-{ echo "$as_me:$LINENO: result: yes" >&5
-echo "${ECHO_T}yes" >&6; }
-
-rm -f a.out a.exe conftest$ac_cv_exeext b.out
-ac_clean_files=$ac_clean_files_save
-# Check that the compiler produces executables we can run.  If not, either
-# the compiler is broken, or we cross compile.
-{ echo "$as_me:$LINENO: checking whether we are cross compiling" >&5
-echo $ECHO_N "checking whether we are cross compiling... $ECHO_C" >&6; }
-{ echo "$as_me:$LINENO: result: $cross_compiling" >&5
-echo "${ECHO_T}$cross_compiling" >&6; }
-
-{ echo "$as_me:$LINENO: checking for suffix of executables" >&5
-echo $ECHO_N "checking for suffix of executables... $ECHO_C" >&6; }
-if { (ac_try="$ac_link"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_link") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; then
-  # If both `conftest.exe' and `conftest' are `present' (well, observable)
-# catch `conftest.exe'.  For instance with Cygwin, `ls conftest' will
-# work properly (i.e., refer to `conftest.exe'), while it won't with
-# `rm'.
-for ac_file in conftest.exe conftest conftest.*; do
-  test -f "$ac_file" || continue
-  case $ac_file in
-    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf | *.o | *.obj ) ;;
-    *.* ) ac_cv_exeext=`expr "$ac_file" : '[^.]*\(\..*\)'`
-	  break;;
-    * ) break;;
-  esac
-done
-else
-  { { echo "$as_me:$LINENO: error: cannot compute suffix of executables: cannot compile and link
-See \`config.log' for more details." >&5
-echo "$as_me: error: cannot compute suffix of executables: cannot compile and link
-See \`config.log' for more details." >&2;}
-   { (exit 1); exit 1; }; }
-fi
-
-rm -f conftest$ac_cv_exeext
-{ echo "$as_me:$LINENO: result: $ac_cv_exeext" >&5
-echo "${ECHO_T}$ac_cv_exeext" >&6; }
-
-rm -f conftest.$ac_ext
-EXEEXT=$ac_cv_exeext
-ac_exeext=$EXEEXT
-{ echo "$as_me:$LINENO: checking for suffix of object files" >&5
-echo $ECHO_N "checking for suffix of object files... $ECHO_C" >&6; }
-if test "${ac_cv_objext+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.o conftest.obj
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compile") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; then
-  for ac_file in conftest.o conftest.obj conftest.*; do
-  test -f "$ac_file" || continue;
-  case $ac_file in
-    *.$ac_ext | *.xcoff | *.tds | *.d | *.pdb | *.xSYM | *.bb | *.bbg | *.map | *.inf ) ;;
-    *) ac_cv_objext=`expr "$ac_file" : '.*\.\(.*\)'`
-       break;;
-  esac
-done
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-{ { echo "$as_me:$LINENO: error: cannot compute suffix of object files: cannot compile
-See \`config.log' for more details." >&5
-echo "$as_me: error: cannot compute suffix of object files: cannot compile
-See \`config.log' for more details." >&2;}
-   { (exit 1); exit 1; }; }
-fi
-
-rm -f conftest.$ac_cv_objext conftest.$ac_ext
-fi
-{ echo "$as_me:$LINENO: result: $ac_cv_objext" >&5
-echo "${ECHO_T}$ac_cv_objext" >&6; }
-OBJEXT=$ac_cv_objext
-ac_objext=$OBJEXT
 { echo "$as_me:$LINENO: checking whether we are using the GNU C compiler" >&5
 echo $ECHO_N "checking whether we are using the GNU C compiler... $ECHO_C" >&6; }
 if test "${ac_cv_c_compiler_gnu+set}" = set; then
@@ -4811,439 +5335,6 @@ ac_cpp='$CXXCPP $CPPFLAGS'
 ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-if test -z "$CXX"; then
-  if test -n "$CCC"; then
-    CXX=$CCC
-  else
-    if test -n "$ac_tool_prefix"; then
-  for ac_prog in g++ c++ gpp aCC CC cxx cc++ cl.exe FCC KCC RCC xlC_r xlC
-  do
-    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
-set dummy $ac_tool_prefix$ac_prog; ac_word=$2
-{ echo "$as_me:$LINENO: checking for $ac_word" >&5
-echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6; }
-if test "${ac_cv_prog_CXX+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  if test -n "$CXX"; then
-  ac_cv_prog_CXX="$CXX" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-  for ac_exec_ext in '' $ac_executable_extensions; do
-  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; }; then
-    ac_cv_prog_CXX="$ac_tool_prefix$ac_prog"
-    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-done
-IFS=$as_save_IFS
-
-fi
-fi
-CXX=$ac_cv_prog_CXX
-if test -n "$CXX"; then
-  { echo "$as_me:$LINENO: result: $CXX" >&5
-echo "${ECHO_T}$CXX" >&6; }
-else
-  { echo "$as_me:$LINENO: result: no" >&5
-echo "${ECHO_T}no" >&6; }
-fi
-
-
-    test -n "$CXX" && break
-  done
-fi
-if test -z "$CXX"; then
-  ac_ct_CXX=$CXX
-  for ac_prog in g++ c++ gpp aCC CC cxx cc++ cl.exe FCC KCC RCC xlC_r xlC
-do
-  # Extract the first word of "$ac_prog", so it can be a program name with args.
-set dummy $ac_prog; ac_word=$2
-{ echo "$as_me:$LINENO: checking for $ac_word" >&5
-echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6; }
-if test "${ac_cv_prog_ac_ct_CXX+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  if test -n "$ac_ct_CXX"; then
-  ac_cv_prog_ac_ct_CXX="$ac_ct_CXX" # Let the user override the test.
-else
-as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in $PATH
-do
-  IFS=$as_save_IFS
-  test -z "$as_dir" && as_dir=.
-  for ac_exec_ext in '' $ac_executable_extensions; do
-  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; }; then
-    ac_cv_prog_ac_ct_CXX="$ac_prog"
-    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
-    break 2
-  fi
-done
-done
-IFS=$as_save_IFS
-
-fi
-fi
-ac_ct_CXX=$ac_cv_prog_ac_ct_CXX
-if test -n "$ac_ct_CXX"; then
-  { echo "$as_me:$LINENO: result: $ac_ct_CXX" >&5
-echo "${ECHO_T}$ac_ct_CXX" >&6; }
-else
-  { echo "$as_me:$LINENO: result: no" >&5
-echo "${ECHO_T}no" >&6; }
-fi
-
-
-  test -n "$ac_ct_CXX" && break
-done
-
-  if test "x$ac_ct_CXX" = x; then
-    CXX="g++"
-  else
-    case $cross_compiling:$ac_tool_warned in
-yes:)
-{ echo "$as_me:$LINENO: WARNING: In the future, Autoconf will not detect cross-tools
-whose name does not start with the host triplet.  If you think this
-configuration is useful to you, please write to autoconf@gnu.org." >&5
-echo "$as_me: WARNING: In the future, Autoconf will not detect cross-tools
-whose name does not start with the host triplet.  If you think this
-configuration is useful to you, please write to autoconf@gnu.org." >&2;}
-ac_tool_warned=yes ;;
-esac
-    CXX=$ac_ct_CXX
-  fi
-fi
-
-  fi
-fi
-# Provide some information about the compiler.
-echo "$as_me:$LINENO: checking for C++ compiler version" >&5
-ac_compiler=`set X $ac_compile; echo $2`
-{ (ac_try="$ac_compiler --version >&5"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compiler --version >&5") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }
-{ (ac_try="$ac_compiler -v >&5"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compiler -v >&5") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }
-{ (ac_try="$ac_compiler -V >&5"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compiler -V >&5") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }
-
-{ echo "$as_me:$LINENO: checking whether we are using the GNU C++ compiler" >&5
-echo $ECHO_N "checking whether we are using the GNU C++ compiler... $ECHO_C" >&6; }
-if test "${ac_cv_cxx_compiler_gnu+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-#ifndef __GNUC__
-       choke me
-#endif
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compile") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_compiler_gnu=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	ac_compiler_gnu=no
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-ac_cv_cxx_compiler_gnu=$ac_compiler_gnu
-
-fi
-{ echo "$as_me:$LINENO: result: $ac_cv_cxx_compiler_gnu" >&5
-echo "${ECHO_T}$ac_cv_cxx_compiler_gnu" >&6; }
-GXX=`test $ac_compiler_gnu = yes && echo yes`
-ac_test_CXXFLAGS=${CXXFLAGS+set}
-ac_save_CXXFLAGS=$CXXFLAGS
-{ echo "$as_me:$LINENO: checking whether $CXX accepts -g" >&5
-echo $ECHO_N "checking whether $CXX accepts -g... $ECHO_C" >&6; }
-if test "${ac_cv_prog_cxx_g+set}" = set; then
-  echo $ECHO_N "(cached) $ECHO_C" >&6
-else
-  ac_save_cxx_werror_flag=$ac_cxx_werror_flag
-   ac_cxx_werror_flag=yes
-   ac_cv_prog_cxx_g=no
-   CXXFLAGS="-g"
-   cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compile") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_cv_prog_cxx_g=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	CXXFLAGS=""
-      cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compile") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  :
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-	 CXXFLAGS="-g"
-	 cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_compile") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } &&
-	 { ac_try='test -z "$ac_cxx_werror_flag" || test ! -s conftest.err'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; } &&
-	 { ac_try='test -s conftest.$ac_objext'
-  { (case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
-  (eval "$ac_try") 2>&5
-  ac_status=$?
-  echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_cv_prog_cxx_g=yes
-else
-  echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-   ac_cxx_werror_flag=$ac_save_cxx_werror_flag
-fi
-{ echo "$as_me:$LINENO: result: $ac_cv_prog_cxx_g" >&5
-echo "${ECHO_T}$ac_cv_prog_cxx_g" >&6; }
-if test "$ac_test_CXXFLAGS" = set; then
-  CXXFLAGS=$ac_save_CXXFLAGS
-elif test $ac_cv_prog_cxx_g = yes; then
-  if test "$GXX" = yes; then
-    CXXFLAGS="-g -O2"
-  else
-    CXXFLAGS="-g"
-  fi
-else
-  if test "$GXX" = yes; then
-    CXXFLAGS="-O2"
-  else
-    CXXFLAGS=
-  fi
-fi
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
-
-
-ac_ext=cpp
-ac_cpp='$CXXCPP $CPPFLAGS'
-ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
 { echo "$as_me:$LINENO: checking how to run the C++ preprocessor" >&5
 echo $ECHO_N "checking how to run the C++ preprocessor... $ECHO_C" >&6; }
 if test -z "$CXXCPP"; then
@@ -7420,6 +7511,13 @@ host_alias!$host_alias$ac_delim
 target_alias!$target_alias$ac_delim
 LLVM_SRC!$LLVM_SRC$ac_delim
 LLVM_OBJ!$LLVM_OBJ$ac_delim
+CXX!$CXX$ac_delim
+CXXFLAGS!$CXXFLAGS$ac_delim
+LDFLAGS!$LDFLAGS$ac_delim
+CPPFLAGS!$CPPFLAGS$ac_delim
+ac_ct_CXX!$ac_ct_CXX$ac_delim
+EXEEXT!$EXEEXT$ac_delim
+OBJEXT!$OBJEXT$ac_delim
 build!$build$ac_delim
 build_cpu!$build_cpu$ac_delim
 build_vendor!$build_vendor$ac_delim
@@ -7436,6 +7534,7 @@ LLVM_VERSION_MAJOR!$LLVM_VERSION_MAJOR$ac_delim
 LLVM_VERSION_MINOR!$LLVM_VERSION_MINOR$ac_delim
 LLVM_IS_RELEASE!$LLVM_IS_RELEASE$ac_delim
 REQUIRES_RTTI!$REQUIRES_RTTI$ac_delim
+KLEE_USE_CXX11!$KLEE_USE_CXX11$ac_delim
 LLVM_BUILD_MODE!$LLVM_BUILD_MODE$ac_delim
 llvm_gcc!$llvm_gcc$ac_delim
 llvm_gxx!$llvm_gxx$ac_delim
@@ -7452,18 +7551,11 @@ RUNTIME_DEBUG_SYMBOLS!$RUNTIME_DEBUG_SYMBOLS$ac_delim
 RUNTIME_CONFIGURATION!$RUNTIME_CONFIGURATION$ac_delim
 CC!$CC$ac_delim
 CFLAGS!$CFLAGS$ac_delim
-LDFLAGS!$LDFLAGS$ac_delim
-CPPFLAGS!$CPPFLAGS$ac_delim
 ac_ct_CC!$ac_ct_CC$ac_delim
-EXEEXT!$EXEEXT$ac_delim
-OBJEXT!$OBJEXT$ac_delim
 CPP!$CPP$ac_delim
 GREP!$GREP$ac_delim
 EGREP!$EGREP$ac_delim
 HAVE_SELINUX!$HAVE_SELINUX$ac_delim
-CXX!$CXX$ac_delim
-CXXFLAGS!$CXXFLAGS$ac_delim
-ac_ct_CXX!$ac_ct_CXX$ac_delim
 CXXCPP!$CXXCPP$ac_delim
 UPSTREAM_STP_LINK_FLAGS!$UPSTREAM_STP_LINK_FLAGS$ac_delim
 STP_NEEDS_BOOST!$STP_NEEDS_BOOST$ac_delim
@@ -7474,7 +7566,7 @@ LIBOBJS!$LIBOBJS$ac_delim
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
 
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 91; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 92; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5