diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 138bd58d86c..0fe8ce89986 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4449,12 +4449,16 @@ dnl
 AC_DEFUN([GLIBCXX_ENABLE_LIBSTDCXX_DUAL_ABI], [
   GLIBCXX_ENABLE(libstdcxx-dual-abi,$1,,[support two versions of std::string])
   if test x$enable_symvers = xgnu-versioned-namespace; then
-    # gnu-versioned-namespace is incompatible with the dual ABI.
-    enable_libstdcxx_dual_abi="no"
-  fi
-  if test x"$enable_libstdcxx_dual_abi" != xyes; then
+    # gnu-versioned-namespace is incompatible with the dual ABI...
     AC_MSG_NOTICE([dual ABI is disabled])
-    default_libstdcxx_abi="gcc4-compatible"
+    enable_libstdcxx_dual_abi="no"
+    # ... and use the cxx11 one.
+    default_libstdcxx_abi="new"
+  else
+    if test x"$enable_libstdcxx_dual_abi" != xyes; then
+      AC_MSG_NOTICE([dual ABI is disabled])
+      default_libstdcxx_abi="gcc4-compatible"
+    fi
   fi
   GLIBCXX_CONDITIONAL(ENABLE_DUAL_ABI, test $enable_libstdcxx_dual_abi = yes)
 ])
diff --git a/libstdc++-v3/config/locale/dragonfly/monetary_members.cc b/libstdc++-v3/config/locale/dragonfly/monetary_members.cc
index 1265190dad9..5f91fd9b560 100644
--- a/libstdc++-v3/config/locale/dragonfly/monetary_members.cc
+++ b/libstdc++-v3/config/locale/dragonfly/monetary_members.cc
@@ -39,7 +39,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 // This file might be compiled twice, but we only want to define the members
 // of money_base once.
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
 
   // Construct and return valid pattern consisting of some combination of:
   // space none symbol sign value
@@ -207,7 +207,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       }
     return __ret;
   }
-#endif
+#endif // ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
 
   template<>
     void
diff --git a/libstdc++-v3/config/locale/generic/monetary_members.cc b/libstdc++-v3/config/locale/generic/monetary_members.cc
index a778a6f402d..6b56e30a568 100644
--- a/libstdc++-v3/config/locale/generic/monetary_members.cc
+++ b/libstdc++-v3/config/locale/generic/monetary_members.cc
@@ -36,7 +36,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 // This file might be compiled twice, but we only want to define the members
 // of money_base once.
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
 
   // Construct and return valid pattern consisting of some combination of:
   // space none symbol sign value
diff --git a/libstdc++-v3/config/locale/gnu/monetary_members.cc b/libstdc++-v3/config/locale/gnu/monetary_members.cc
index 556575363da..54be63c44d7 100644
--- a/libstdc++-v3/config/locale/gnu/monetary_members.cc
+++ b/libstdc++-v3/config/locale/gnu/monetary_members.cc
@@ -37,7 +37,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 // This file might be compiled twice, but we only want to define the members
 // of money_base once.
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
 
   // Construct and return valid pattern consisting of some combination of:
   // space none symbol sign value
@@ -205,7 +205,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       }
     return __ret;
   }
-#endif
+#endif // ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
 
   extern char __narrow_multibyte_chars(const char* s, __locale_t cloc);
 
diff --git a/libstdc++-v3/config/locale/gnu/numeric_members.cc b/libstdc++-v3/config/locale/gnu/numeric_members.cc
index c714d6a544f..ae17cb76c81 100644
--- a/libstdc++-v3/config/locale/gnu/numeric_members.cc
+++ b/libstdc++-v3/config/locale/gnu/numeric_members.cc
@@ -39,7 +39,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   extern char __narrow_multibyte_chars(const char* s, __locale_t cloc);
 
 // This file might be compiled twice, but we only want to define this once.
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   char
   __narrow_multibyte_chars(const char* s, __locale_t cloc)
   {
@@ -84,7 +84,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       }
     return '\0';
   }
-#endif
+#endif // ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
 
   template<>
     void
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 9b94fd71e42..d3c4106a74a 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -75217,13 +75217,18 @@ fi
 
 
   if test x$enable_symvers = xgnu-versioned-namespace; then
-    # gnu-versioned-namespace is incompatible with the dual ABI.
-    enable_libstdcxx_dual_abi="no"
-  fi
-  if test x"$enable_libstdcxx_dual_abi" != xyes; then
+    # gnu-versioned-namespace is incompatible with the dual ABI...
     { $as_echo "$as_me:${as_lineno-$LINENO}: dual ABI is disabled" >&5
 $as_echo "$as_me: dual ABI is disabled" >&6;}
-    default_libstdcxx_abi="gcc4-compatible"
+    enable_libstdcxx_dual_abi="no"
+    # ... and use the cxx11 one.
+    default_libstdcxx_abi="new"
+  else
+    if test x"$enable_libstdcxx_dual_abi" != xyes; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: dual ABI is disabled" >&5
+$as_echo "$as_me: dual ABI is disabled" >&6;}
+      default_libstdcxx_abi="gcc4-compatible"
+    fi
   fi
 
 
diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 191880fb99d..f899a580b60 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -325,26 +325,6 @@ namespace std
 #define _GLIBCXX_USE_CXX11_ABI
 #endif
 
-#if _GLIBCXX_USE_CXX11_ABI
-namespace std
-{
-  inline namespace __cxx11 __attribute__((__abi_tag__ ("cxx11"))) { }
-}
-namespace __gnu_cxx
-{
-  inline namespace __cxx11 __attribute__((__abi_tag__ ("cxx11"))) { }
-}
-# define _GLIBCXX_NAMESPACE_CXX11 __cxx11::
-# define _GLIBCXX_BEGIN_NAMESPACE_CXX11 namespace __cxx11 {
-# define _GLIBCXX_END_NAMESPACE_CXX11 }
-# define _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_ABI_TAG_CXX11
-#else
-# define _GLIBCXX_NAMESPACE_CXX11
-# define _GLIBCXX_BEGIN_NAMESPACE_CXX11
-# define _GLIBCXX_END_NAMESPACE_CXX11
-# define _GLIBCXX_DEFAULT_ABI_TAG
-#endif
-
 // Non-zero if inline namespaces are used for versioning the entire library.
 #define _GLIBCXX_INLINE_VERSION 
 
@@ -396,7 +376,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // Non-inline namespace for components replaced by alternates in active mode.
   namespace __cxx1998
   {
-# if _GLIBCXX_USE_CXX11_ABI
+# if _GLIBCXX_USE_CXX11_ABI && ! _GLIBCXX_VERSION_NAMESPACE
   inline namespace __cxx11 __attribute__((__abi_tag__ ("cxx11"))) { }
 # endif
   }
@@ -426,6 +406,26 @@ _GLIBCXX_END_NAMESPACE_VERSION
 # endif
 #endif
 
+#if _GLIBCXX_USE_CXX11_ABI && ! _GLIBCXX_INLINE_VERSION
+namespace std
+{
+  inline namespace __cxx11 __attribute__((__abi_tag__ ("cxx11"))) { }
+}
+namespace __gnu_cxx
+{
+  inline namespace __cxx11 __attribute__((__abi_tag__ ("cxx11"))) { }
+}
+# define _GLIBCXX_NAMESPACE_CXX11 __cxx11::
+# define _GLIBCXX_BEGIN_NAMESPACE_CXX11 namespace __cxx11 {
+# define _GLIBCXX_END_NAMESPACE_CXX11 }
+# define _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_ABI_TAG_CXX11
+#else
+# define _GLIBCXX_NAMESPACE_CXX11
+# define _GLIBCXX_BEGIN_NAMESPACE_CXX11
+# define _GLIBCXX_END_NAMESPACE_CXX11
+# define _GLIBCXX_DEFAULT_ABI_TAG
+#endif
+
 // Macros for namespace scope. Either namespace std:: or the name
 // of some nested namespace within it corresponding to the active mode.
 // _GLIBCXX_STD_A
diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py b/libstdc++-v3/python/libstdcxx/v6/printers.py
index 17c33c1e54f..f11ac066966 100644
--- a/libstdc++-v3/python/libstdcxx/v6/printers.py
+++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
@@ -942,6 +942,8 @@ class StdStringPrinter:
     def __init__(self, typename, val):
         self.val = val
         self.new_string = typename.find("::__cxx11::basic_string") != -1
+        if not self.new_string and _versioned_namespace:
+            self.new_string = typename.find("::" + _versioned_namespace + "basic_string") != -1
 
     def to_string(self):
         # Make sure &string works, too.
diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index b83c222d51d..fcab83ada2d 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -82,6 +82,9 @@ else
 ldbl_compat_sources =
 endif
 
+if ENABLE_SYMVERS_GNU_NAMESPACE
+ldbl_alt128_compat_sources =
+else
 if GLIBCXX_LDBL_ALT128_COMPAT
 if ENABLE_DUAL_ABI
 ldbl_alt128_compat_cxx11_sources = \
@@ -95,6 +98,7 @@ ldbl_alt128_compat_sources = \
 else
 ldbl_alt128_compat_sources =
 endif
+endif
 
 if ENABLE_SYMVERS_GNU_NAMESPACE
 cxx0x_compat_sources =
diff --git a/libstdc++-v3/src/Makefile.in b/libstdc++-v3/src/Makefile.in
index cef290c5d11..946101389c4 100644
--- a/libstdc++-v3/src/Makefile.in
+++ b/libstdc++-v3/src/Makefile.in
@@ -158,10 +158,9 @@ am__objects_2 = compatibility.lo compatibility-debug_list.lo \
 @ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-chrono.lo \
 @ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-condvar.lo \
 @ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-thread-c++0x.lo
-@ENABLE_DUAL_ABI_TRUE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_4 = compatibility-ldbl-alt128-cxx11.lo
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_5 =  \
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128.lo \
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	$(am__objects_4)
+@ENABLE_DUAL_ABI_TRUE@@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_4 = compatibility-ldbl-alt128-cxx11.lo
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@am__objects_5 = compatibility-ldbl-alt128.lo \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	$(am__objects_4)
 am__objects_6 = $(am__objects_3) $(am__objects_5)
 am_libstdc___la_OBJECTS = $(am__objects_2) $(am__objects_6)
 libstdc___la_OBJECTS = $(am_libstdc___la_OBJECTS)
@@ -506,14 +505,15 @@ SUBDIRS = c++98 c++11 c++17 c++20 $(filesystem_dir) $(backtrace_dir)
 
 @GLIBCXX_LDBL_COMPAT_FALSE@ldbl_compat_sources = 
 @GLIBCXX_LDBL_COMPAT_TRUE@ldbl_compat_sources = compatibility-ldbl.cc
-@ENABLE_DUAL_ABI_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@ldbl_alt128_compat_cxx11_sources = 
-@ENABLE_DUAL_ABI_TRUE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@ldbl_alt128_compat_cxx11_sources = \
-@ENABLE_DUAL_ABI_TRUE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128-cxx11.cc
-
-@GLIBCXX_LDBL_ALT128_COMPAT_FALSE@ldbl_alt128_compat_sources = 
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@ldbl_alt128_compat_sources = \
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128.cc \
-@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	${ldbl_alt128_compat_cxx11_sources}
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_FALSE@ldbl_alt128_compat_sources = 
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@ldbl_alt128_compat_sources = \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128.cc \
+@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	${ldbl_alt128_compat_cxx11_sources}
+
+@ENABLE_SYMVERS_GNU_NAMESPACE_TRUE@ldbl_alt128_compat_sources = 
+@ENABLE_DUAL_ABI_FALSE@@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@ldbl_alt128_compat_cxx11_sources = 
+@ENABLE_DUAL_ABI_TRUE@@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@ldbl_alt128_compat_cxx11_sources = \
+@ENABLE_DUAL_ABI_TRUE@@ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@@GLIBCXX_LDBL_ALT128_COMPAT_TRUE@	compatibility-ldbl-alt128-cxx11.cc
 
 @ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@cxx0x_compat_sources = \
 @ENABLE_SYMVERS_GNU_NAMESPACE_FALSE@	compatibility-atomic-c++0x.cc \
diff --git a/libstdc++-v3/src/c++11/Makefile.am b/libstdc++-v3/src/c++11/Makefile.am
index ecd46aafc01..b22c54fa057 100644
--- a/libstdc++-v3/src/c++11/Makefile.am
+++ b/libstdc++-v3/src/c++11/Makefile.am
@@ -40,22 +40,22 @@ ctype_members.cc: ${glibcxx_srcdir}/$(CCTYPE_CC)
 	$(LN_S) ${glibcxx_srcdir}/$(CCTYPE_CC) . || true
 
 if ENABLE_DUAL_ABI
-cxx11_abi_sources = \
-	cow-locale_init.cc \
+dual_abi_sources = \
 	cow-shim_facets.cc \
-	cxx11-hash_tr1.cc \
-	cxx11-ios_failure.cc \
-	cxx11-shim_facets.cc \
-	cxx11-stdexcept.cc
+	cxx11-shim_facets.cc
 else
-cxx11_abi_sources =
+dual_abi_sources =
 endif
 
 sources = \
 	chrono.cc \
 	codecvt.cc \
 	condition_variable.cc \
+	cow-locale_init.cc \
 	cow-stdexcept.cc \
+	cxx11-hash_tr1.cc \
+	cxx11-ios_failure.cc \
+	cxx11-stdexcept.cc \
 	ctype.cc \
 	debug.cc \
 	functexcept.cc \
@@ -75,19 +75,11 @@ sources = \
 	snprintf_lite.cc \
 	system_error.cc \
 	thread.cc \
-	${cxx11_abi_sources} \
+	${dual_abi_sources} \
 	${host_sources}
 
 if ENABLE_DUAL_ABI
 extra_string_inst_sources = \
-	cow-fstream-inst.cc \
-	cow-sstream-inst.cc \
-	cow-string-inst.cc \
-	cow-string-io-inst.cc \
-	cow-wstring-inst.cc \
-	cow-wstring-io-inst.cc \
-	cxx11-locale-inst.cc \
-	cxx11-wlocale-inst.cc \
 	sso_string.cc
 else
 extra_string_inst_sources =
@@ -97,6 +89,14 @@ if ENABLE_EXTERN_TEMPLATE
 # XTEMPLATE_FLAGS = -fno-implicit-templates
 inst_sources = \
 	$(extra_string_inst_sources) \
+	cow-fstream-inst.cc \
+	cow-sstream-inst.cc \
+	cow-string-inst.cc \
+	cow-string-io-inst.cc \
+	cow-wstring-inst.cc \
+	cow-wstring-io-inst.cc \
+	cxx11-locale-inst.cc \
+	cxx11-wlocale-inst.cc \
 	ext11-inst.cc \
 	fstream-inst.cc \
 	ios-inst.cc \
diff --git a/libstdc++-v3/src/c++11/Makefile.in b/libstdc++-v3/src/c++11/Makefile.in
index 4db28bd8515..fa5b9543f76 100644
--- a/libstdc++-v3/src/c++11/Makefile.in
+++ b/libstdc++-v3/src/c++11/Makefile.in
@@ -122,26 +122,27 @@ CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
 LTLIBRARIES = $(noinst_LTLIBRARIES)
 libc__11convenience_la_LIBADD =
-@ENABLE_DUAL_ABI_TRUE@am__objects_1 = cow-locale_init.lo \
-@ENABLE_DUAL_ABI_TRUE@	cow-shim_facets.lo cxx11-hash_tr1.lo \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-ios_failure.lo \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-shim_facets.lo cxx11-stdexcept.lo
+@ENABLE_DUAL_ABI_TRUE@am__objects_1 = cow-shim_facets.lo \
+@ENABLE_DUAL_ABI_TRUE@	cxx11-shim_facets.lo
 am__objects_2 = ctype_configure_char.lo ctype_members.lo
 am__objects_3 = chrono.lo codecvt.lo condition_variable.lo \
-	cow-stdexcept.lo ctype.lo debug.lo functexcept.lo \
-	functional.lo futex.lo future.lo hash_c++0x.lo \
+	cow-locale_init.lo cow-stdexcept.lo cxx11-hash_tr1.lo \
+	cxx11-ios_failure.lo cxx11-stdexcept.lo ctype.lo debug.lo \
+	functexcept.lo functional.lo futex.lo future.lo hash_c++0x.lo \
 	hashtable_c++0x.lo ios.lo ios_errcat.lo limits.lo mutex.lo \
 	placeholders.lo random.lo regex.lo shared_ptr.lo \
 	snprintf_lite.lo system_error.lo thread.lo $(am__objects_1) \
 	$(am__objects_2)
-@ENABLE_DUAL_ABI_TRUE@am__objects_4 = cow-fstream-inst.lo \
-@ENABLE_DUAL_ABI_TRUE@	cow-sstream-inst.lo cow-string-inst.lo \
-@ENABLE_DUAL_ABI_TRUE@	cow-string-io-inst.lo \
-@ENABLE_DUAL_ABI_TRUE@	cow-wstring-inst.lo \
-@ENABLE_DUAL_ABI_TRUE@	cow-wstring-io-inst.lo \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-locale-inst.lo \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-wlocale-inst.lo sso_string.lo
+@ENABLE_DUAL_ABI_TRUE@am__objects_4 = sso_string.lo
 @ENABLE_EXTERN_TEMPLATE_TRUE@am__objects_5 = $(am__objects_4) \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-fstream-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-sstream-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-string-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-string-io-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-wstring-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-wstring-io-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cxx11-locale-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cxx11-wlocale-inst.lo \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	ext11-inst.lo fstream-inst.lo \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	ios-inst.lo iostream-inst.lo \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	istream-inst.lo locale-inst.lo \
@@ -457,20 +458,20 @@ host_sources = \
 	ctype_configure_char.cc \
 	ctype_members.cc
 
-@ENABLE_DUAL_ABI_FALSE@cxx11_abi_sources = 
-@ENABLE_DUAL_ABI_TRUE@cxx11_abi_sources = \
-@ENABLE_DUAL_ABI_TRUE@	cow-locale_init.cc \
+@ENABLE_DUAL_ABI_FALSE@dual_abi_sources = 
+@ENABLE_DUAL_ABI_TRUE@dual_abi_sources = \
 @ENABLE_DUAL_ABI_TRUE@	cow-shim_facets.cc \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-hash_tr1.cc \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-ios_failure.cc \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-shim_facets.cc \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-stdexcept.cc
+@ENABLE_DUAL_ABI_TRUE@	cxx11-shim_facets.cc
 
 sources = \
 	chrono.cc \
 	codecvt.cc \
 	condition_variable.cc \
+	cow-locale_init.cc \
 	cow-stdexcept.cc \
+	cxx11-hash_tr1.cc \
+	cxx11-ios_failure.cc \
+	cxx11-stdexcept.cc \
 	ctype.cc \
 	debug.cc \
 	functexcept.cc \
@@ -490,19 +491,11 @@ sources = \
 	snprintf_lite.cc \
 	system_error.cc \
 	thread.cc \
-	${cxx11_abi_sources} \
+	${dual_abi_sources} \
 	${host_sources}
 
 @ENABLE_DUAL_ABI_FALSE@extra_string_inst_sources = 
 @ENABLE_DUAL_ABI_TRUE@extra_string_inst_sources = \
-@ENABLE_DUAL_ABI_TRUE@	cow-fstream-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cow-sstream-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cow-string-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cow-string-io-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cow-wstring-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cow-wstring-io-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-locale-inst.cc \
-@ENABLE_DUAL_ABI_TRUE@	cxx11-wlocale-inst.cc \
 @ENABLE_DUAL_ABI_TRUE@	sso_string.cc
 
 # XTEMPLATE_FLAGS =
@@ -511,6 +504,14 @@ sources = \
 # XTEMPLATE_FLAGS = -fno-implicit-templates
 @ENABLE_EXTERN_TEMPLATE_TRUE@inst_sources = \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	$(extra_string_inst_sources) \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-fstream-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-sstream-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-string-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-string-io-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-wstring-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cow-wstring-io-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cxx11-locale-inst.cc \
+@ENABLE_EXTERN_TEMPLATE_TRUE@	cxx11-wlocale-inst.cc \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	ext11-inst.cc \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	fstream-inst.cc \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	ios-inst.cc \
diff --git a/libstdc++-v3/src/c++11/cow-fstream-inst.cc b/libstdc++-v3/src/c++11/cow-fstream-inst.cc
index 6b6352c1419..d9657484326 100644
--- a/libstdc++-v3/src/c++11/cow-fstream-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-fstream-inst.cc
@@ -29,10 +29,7 @@
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <fstream>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
-
+#if ! _GLIBCXX_USE_CXX11_ABI
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -76,3 +73,4 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+#endif
diff --git a/libstdc++-v3/src/c++11/cow-locale_init.cc b/libstdc++-v3/src/c++11/cow-locale_init.cc
index 4d5c08f20cc..fa27b4142f2 100644
--- a/libstdc++-v3/src/c++11/cow-locale_init.cc
+++ b/libstdc++-v3/src/c++11/cow-locale_init.cc
@@ -24,10 +24,7 @@
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <locale>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
-
+#if ! _GLIBCXX_USE_CXX11_ABI
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -193,3 +190,4 @@ namespace
 
 _GLIBCXX_END_NAMESPACE_VERSION
 }
+#endif // ! _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++11/cow-sstream-inst.cc b/libstdc++-v3/src/c++11/cow-sstream-inst.cc
index 8839f4a6f75..2db78a43f50 100644
--- a/libstdc++-v3/src/c++11/cow-sstream-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-sstream-inst.cc
@@ -27,8 +27,8 @@
 //
 
 #define _GLIBCXX_USE_CXX11_ABI 0
-#include "sstream-inst.cc"
+#include <bits/c++config.h>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
+#if ! _GLIBCXX_USE_CXX11_ABI
+# include "sstream-inst.cc"
 #endif
diff --git a/libstdc++-v3/src/c++11/cow-stdexcept.cc b/libstdc++-v3/src/c++11/cow-stdexcept.cc
index 9e8787485eb..8b217c45960 100644
--- a/libstdc++-v3/src/c++11/cow-stdexcept.cc
+++ b/libstdc++-v3/src/c++11/cow-stdexcept.cc
@@ -41,7 +41,7 @@ _txnal_logic_error_get_msg(void* e);
 void*
 _txnal_runtime_error_get_msg(void* e);
 
-// All exception classes still use the classic COW std::string.
+// In dual abi all exception classes still use the classic COW std::string.
 #define _GLIBCXX_USE_CXX11_ABI 0
 #define _GLIBCXX_DEFINE_STDEXCEPT_COPY_OPS 1
 #define __cow_string __cow_stringxxx
@@ -169,6 +169,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                 "alignof(std::string) has changed");
 #endif
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   // Return error_category::message() as an SSO string
   __sso_string
   error_category::_M_message(int i) const
@@ -176,10 +177,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     string msg = this->message(i);
     return {msg.c_str(), msg.length()};
   }
+#endif
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 
+#if ! _GLIBCXX_USE_CXX11_ABI
 // Support for the Transactional Memory TS (N4514).
 //
 // logic_error and runtime_error both carry a message in the form of a COW
@@ -463,3 +466,4 @@ CTORDTOR(15underflow_error, std::underflow_error, runtime_error)
 
 #endif  // _GLIBCXX_USE_C99_STDINT_TR1
 #endif  // _GLIBCXX_USE_WEAK_REF
+#endif  // ! _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++11/cow-string-inst.cc b/libstdc++-v3/src/c++11/cow-string-inst.cc
index e5331bb029a..40ebe708971 100644
--- a/libstdc++-v3/src/c++11/cow-string-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-string-inst.cc
@@ -27,11 +27,10 @@
 //
 
 #define _GLIBCXX_USE_CXX11_ABI 0
-#include "string-inst.cc"
+#include <bits/c++config.h>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
+#if ! _GLIBCXX_USE_CXX11_ABI
+#include "string-inst.cc"
 
 #ifdef  _GLIBCXX_USE_C99_STDINT_TR1
 #include <random>
@@ -47,3 +46,4 @@ namespace std _GLIBCXX_VISIBILITY(default)
   { _M_init(token.c_str(), token.length()); }
 } // namespace
 #endif
+#endif
diff --git a/libstdc++-v3/src/c++11/cow-string-io-inst.cc b/libstdc++-v3/src/c++11/cow-string-io-inst.cc
index 3f65aeb9873..a3720680907 100644
--- a/libstdc++-v3/src/c++11/cow-string-io-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-string-io-inst.cc
@@ -30,10 +30,7 @@
 #include <istream>
 #include <ostream>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
-
+#if ! _GLIBCXX_USE_CXX11_ABI
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -57,3 +54,4 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+#endif
diff --git a/libstdc++-v3/src/c++11/cow-wstring-inst.cc b/libstdc++-v3/src/c++11/cow-wstring-inst.cc
index a38c1288ef3..b0eff7ef97d 100644
--- a/libstdc++-v3/src/c++11/cow-wstring-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-wstring-inst.cc
@@ -29,12 +29,9 @@
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <bits/c++config.h>
 
+#if ! _GLIBCXX_USE_CXX11_ABI
 #ifdef _GLIBCXX_USE_WCHAR_T
 #define C wchar_t
 #include "string-inst.cc"
-
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
 #endif
-
 #endif
diff --git a/libstdc++-v3/src/c++11/cow-wstring-io-inst.cc b/libstdc++-v3/src/c++11/cow-wstring-io-inst.cc
index dbd19e0feb0..f0ed5cc6b6b 100644
--- a/libstdc++-v3/src/c++11/cow-wstring-io-inst.cc
+++ b/libstdc++-v3/src/c++11/cow-wstring-io-inst.cc
@@ -29,14 +29,11 @@
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <bits/c++config.h>
 
+#if ! _GLIBCXX_USE_CXX11_ABI
 #ifdef _GLIBCXX_USE_WCHAR_T
 #include <ostream>
 #include <istream>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
-
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -61,3 +58,4 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 #endif
+#endif
diff --git a/libstdc++-v3/src/c++11/cxx11-hash_tr1.cc b/libstdc++-v3/src/c++11/cxx11-hash_tr1.cc
index f36541fd4cc..edd89974e1b 100644
--- a/libstdc++-v3/src/c++11/cxx11-hash_tr1.cc
+++ b/libstdc++-v3/src/c++11/cxx11-hash_tr1.cc
@@ -25,9 +25,7 @@
 #define _GLIBCXX_USE_CXX11_ABI 1
 #include <string>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
+#if _GLIBCXX_USE_CXX11_ABI
 
 #include <tr1/functional>
 namespace std _GLIBCXX_VISIBILITY(default)
@@ -57,3 +55,5 @@ namespace std _GLIBCXX_VISIBILITY(default)
 #endif
   }
 }
+
+#endif // _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++11/cxx11-ios_failure.cc b/libstdc++-v3/src/c++11/cxx11-ios_failure.cc
index 0a81e15e4c0..db4c623a536 100644
--- a/libstdc++-v3/src/c++11/cxx11-ios_failure.cc
+++ b/libstdc++-v3/src/c++11/cxx11-ios_failure.cc
@@ -38,9 +38,7 @@
 # define _(msgid)   (msgid)
 #endif
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
+#if _GLIBCXX_USE_CXX11_ABI
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -62,7 +60,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   ios_base::failure::what() const throw()
   { return runtime_error::what(); }
 
-#if __cpp_rtti
+#if _GLIBCXX_USE_DUAL_ABI && __cpp_rtti
   // These functions are defined in src/c++98/ios_failure.cc
   extern void __construct_ios_failure(void*, const char*);
   extern void __destroy_ios_failure(void*);
@@ -118,7 +116,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     // Otherwise proceed as normal to see if the handler matches.
     return __class_type_info::__do_upcast(dst_type, obj_ptr);
   }
-#else // ! __cpp_rtti
+#else // ! _GLIBCXX_USE_DUAL_ABI || ! __cpp_rtti
   using __ios_failure = ios::failure;
 #endif
 
@@ -136,3 +134,5 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+
+#endif // _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++11/cxx11-locale-inst.cc b/libstdc++-v3/src/c++11/cxx11-locale-inst.cc
index 5c860054ea6..814cdcc9902 100644
--- a/libstdc++-v3/src/c++11/cxx11-locale-inst.cc
+++ b/libstdc++-v3/src/c++11/cxx11-locale-inst.cc
@@ -27,11 +27,5 @@
 // Facet instantiations using new ABI strings.
 
 #define _GLIBCXX_USE_CXX11_ABI 1
-#include <bits/c++config.h>
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
 
-#define C char
-#define C_is_char
-# include "locale-inst.cc"
+#include "locale-inst.cc"
diff --git a/libstdc++-v3/src/c++11/cxx11-stdexcept.cc b/libstdc++-v3/src/c++11/cxx11-stdexcept.cc
index 236bc40cd55..9faf355977a 100644
--- a/libstdc++-v3/src/c++11/cxx11-stdexcept.cc
+++ b/libstdc++-v3/src/c++11/cxx11-stdexcept.cc
@@ -29,9 +29,7 @@
 #define _GLIBCXX_USE_CXX11_ABI 1
 #include <stdexcept>
 
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
+#if _GLIBCXX_USE_CXX11_ABI
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -70,9 +68,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   underflow_error::underflow_error(const string& __arg)
   : runtime_error(__arg) { }
 
+# if _GLIBCXX_USE_DUAL_ABI
   // Converting constructor from ABI-tagged std::string to COW string.
   __cow_string::__cow_string(const string& s)
   : __cow_string(s.c_str(), s.length()) { }
+# endif
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+
+#endif // _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++11/cxx11-wlocale-inst.cc b/libstdc++-v3/src/c++11/cxx11-wlocale-inst.cc
index 6d26292075d..7491d5117df 100644
--- a/libstdc++-v3/src/c++11/cxx11-wlocale-inst.cc
+++ b/libstdc++-v3/src/c++11/cxx11-wlocale-inst.cc
@@ -28,11 +28,10 @@
 
 #define _GLIBCXX_USE_CXX11_ABI 1
 #include <bits/c++config.h>
-#if ! _GLIBCXX_USE_DUAL_ABI
-# error This file should not be compiled for this configuration.
-#endif
 
-#ifdef _GLIBCXX_USE_WCHAR_T
-#define C wchar_t
-#include "locale-inst.cc"
+#if _GLIBCXX_USE_CXX11_ABI
+# ifdef _GLIBCXX_USE_WCHAR_T
+#  define C wchar_t
+#  include "locale-inst.cc"
+# endif
 #endif
diff --git a/libstdc++-v3/src/c++11/fstream-inst.cc b/libstdc++-v3/src/c++11/fstream-inst.cc
index 7bf56c7e864..494c7bb51d0 100644
--- a/libstdc++-v3/src/c++11/fstream-inst.cc
+++ b/libstdc++-v3/src/c++11/fstream-inst.cc
@@ -29,6 +29,7 @@
 #define _GLIBCXX_USE_CXX11_ABI 1
 #include <fstream>
 
+#if _GLIBCXX_USE_CXX11_ABI
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -47,3 +48,4 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+#endif
diff --git a/libstdc++-v3/src/c++11/locale-inst-numeric.h b/libstdc++-v3/src/c++11/locale-inst-numeric.h
index 1417ac25ed4..5b72c30bd5a 100644
--- a/libstdc++-v3/src/c++11/locale-inst-numeric.h
+++ b/libstdc++-v3/src/c++11/locale-inst-numeric.h
@@ -23,12 +23,12 @@
 // <http://www.gnu.org/licenses/>.
 
 #ifndef C
-#define "This file should not be compiled directly, only included"
+# error "This file should not be compiled directly, only included"
 #endif
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template const num_get<C>& use_facet<num_get<C> >(const locale&);
   template const num_put<C>& use_facet<num_put<C> >(const locale&);
 
@@ -38,7 +38,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
 
 _GLIBCXX_BEGIN_NAMESPACE_LDBL
 
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template class num_get<C, istreambuf_iterator<C> >;
   template class num_put<C, ostreambuf_iterator<C> >;
 #endif
@@ -88,7 +88,7 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
 		   unsigned long long&) const;
 #endif
 
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   // num_put member function templates
   template
     ostreambuf_iterator<C>
diff --git a/libstdc++-v3/src/c++11/locale-inst.cc b/libstdc++-v3/src/c++11/locale-inst.cc
index 3aee5df9b04..30847cbef7f 100644
--- a/libstdc++-v3/src/c++11/locale-inst.cc
+++ b/libstdc++-v3/src/c++11/locale-inst.cc
@@ -35,8 +35,17 @@
 # define _GLIBCXX_USE_CXX11_ABI 0
 #endif
 
-#include <locale>
+#if _GLIBCXX_USE_CXX11_ABI
+# define _GLIBCXX_BUILD_CXX11_ABI 1
+#else
+# define _GLIBCXX_BUILD_CXX11_ABI 0
+#endif
+
+#include <bits/c++config.h>
 
+#if _GLIBCXX_BUILD_CXX11_ABI == _GLIBCXX_USE_CXX11_ABI
+
+#include <locale>
 // Instantiation configuration.
 #ifndef C
 # define C char
@@ -51,7 +60,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   // moneypunct, money_get, and money_put
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template struct __moneypunct_cache<C, false>;
   template struct __moneypunct_cache<C, true>;
 #endif
@@ -63,7 +72,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 _GLIBCXX_END_NAMESPACE_CXX11
 
   // numpunct, numpunct_byname, num_get, and num_put
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template struct __numpunct_cache<C>;
 #endif
 _GLIBCXX_BEGIN_NAMESPACE_CXX11
@@ -72,7 +81,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 _GLIBCXX_END_NAMESPACE_CXX11
 
   // time_get and time_put
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template class __timepunct<C>;
   template struct __timepunct_cache<C>;
   template class time_put<C, ostreambuf_iterator<C> >;
@@ -96,13 +105,13 @@ _GLIBCXX_END_NAMESPACE_CXX11
   ctype_byname<C>::ctype_byname(const string& __s, size_t __refs)
   : ctype_byname(__s.c_str(), __refs) { }
 
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   inline template class __ctype_abstract_base<C>;
   template class ctype_byname<C>;
 #endif
 
   // codecvt
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   inline template class __codecvt_abstract_base<C, char, mbstate_t>;
   template class codecvt_byname<C, char, mbstate_t>;
 #else
@@ -117,7 +126,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 _GLIBCXX_END_NAMESPACE_CXX11
 
   // use_facet
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template
     const ctype<C>&
     use_facet<ctype<C> >(const locale&);
@@ -143,7 +152,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     const moneypunct<C, false>&
     use_facet<moneypunct<C, false> >(const locale&);
 
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template
     const __timepunct<C>&
     use_facet<__timepunct<C> >(const locale&);
@@ -162,7 +171,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     use_facet<messages<C> >(const locale&);
 
   // has_facet
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template
     bool
     has_facet<ctype<C> >(const locale&);
@@ -184,7 +193,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     bool
     has_facet<moneypunct<C> >(const locale&);
 
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   template
     bool
     has_facet<__timepunct<C> >(const locale&);
@@ -203,7 +212,7 @@ _GLIBCXX_END_NAMESPACE_CXX11
     has_facet<messages<C> >(const locale&);
 
 
-#if ! _GLIBCXX_USE_CXX11_ABI
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
   // locale functions.
   template
     C*
@@ -228,7 +237,11 @@ _GLIBCXX_END_NAMESPACE_CXX11
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 
+#if ! _GLIBCXX_INLINE_VERSION
 // XXX GLIBCXX_ABI Deprecated
-#if defined _GLIBCXX_LONG_DOUBLE_COMPAT && ! _GLIBCXX_USE_CXX11_ABI
-#include "compatibility-ldbl-facets-aliases.h"
-#endif // _GLIBCXX_LONG_DOUBLE_COMPAT
+# if defined _GLIBCXX_LONG_DOUBLE_COMPAT && ! _GLIBCXX_USE_CXX11_ABI
+#  include "compatibility-ldbl-facets-aliases.h"
+# endif // _GLIBCXX_LONG_DOUBLE_COMPAT
+#endif
+
+#endif //  _GLIBCXX_BUILD_CXX11_ABI == _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++11/wlocale-inst.cc b/libstdc++-v3/src/c++11/wlocale-inst.cc
index 0855f67707c..0338a9554a2 100644
--- a/libstdc++-v3/src/c++11/wlocale-inst.cc
+++ b/libstdc++-v3/src/c++11/wlocale-inst.cc
@@ -30,7 +30,9 @@
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <bits/c++config.h>
 
-#ifdef _GLIBCXX_USE_WCHAR_T
-#define C wchar_t
-#include "locale-inst.cc"
-#endif // _GLIBCXX_USE_WCHAR_T
+#if ! _GLIBCXX_USE_CXX11_ABI
+# ifdef _GLIBCXX_USE_WCHAR_T
+#  define C wchar_t
+#  include "locale-inst.cc"
+# endif // _GLIBCXX_USE_WCHAR_T
+#endif
diff --git a/libstdc++-v3/src/c++98/Makefile.am b/libstdc++-v3/src/c++98/Makefile.am
index b96588bd95c..9bbe8c00a73 100644
--- a/libstdc++-v3/src/c++98/Makefile.am
+++ b/libstdc++-v3/src/c++98/Makefile.am
@@ -90,13 +90,6 @@ c++locale.cc: ${glibcxx_srcdir}/$(CLOCALE_CC)
 basic_file.cc: ${glibcxx_srcdir}/$(BASIC_FILE_CC)
 	$(LN_S) ${glibcxx_srcdir}/$(BASIC_FILE_CC) ./$@ || true
 
-if ENABLE_DUAL_ABI
-cxx11_abi_sources = \
-	cow-istream-string.cc
-else
-cxx11_abi_sources =
-endif
-
 if ENABLE_EXTERN_TEMPLATE
 # XTEMPLATE_FLAGS = -fno-implicit-templates
 inst_sources = \
@@ -118,6 +111,7 @@ sources = \
 	mt_allocator.cc \
 	codecvt.cc \
 	complex_io.cc \
+	cow-istream-string.cc \
 	globals_io.cc \
 	hash_tr1.cc \
 	hashtable_tr1.cc \
@@ -142,7 +136,6 @@ sources = \
 	istream-string.cc \
 	streambuf.cc \
 	valarray.cc \
-	${cxx11_abi_sources} \
 	${host_sources} \
 	${host_sources_extra}
 
diff --git a/libstdc++-v3/src/c++98/Makefile.in b/libstdc++-v3/src/c++98/Makefile.in
index 90eff5da986..aafc04efe89 100644
--- a/libstdc++-v3/src/c++98/Makefile.in
+++ b/libstdc++-v3/src/c++98/Makefile.in
@@ -122,30 +122,29 @@ CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
 LTLIBRARIES = $(noinst_LTLIBRARIES)
 libc__98convenience_la_LIBADD =
-@ENABLE_DUAL_ABI_TRUE@am__objects_1 = cow-istream-string.lo
-@ENABLE_DUAL_ABI_TRUE@am__objects_2 = collate_members_cow.lo \
+@ENABLE_DUAL_ABI_TRUE@am__objects_1 = collate_members_cow.lo \
 @ENABLE_DUAL_ABI_TRUE@	messages_members_cow.lo \
 @ENABLE_DUAL_ABI_TRUE@	monetary_members_cow.lo \
 @ENABLE_DUAL_ABI_TRUE@	numeric_members_cow.lo
-am__objects_3 = $(am__objects_2) codecvt_members.lo collate_members.lo \
+am__objects_2 = $(am__objects_1) codecvt_members.lo collate_members.lo \
 	messages_members.lo monetary_members.lo numeric_members.lo \
 	time_members.lo
-@ENABLE_EXTERN_TEMPLATE_TRUE@am__objects_4 = allocator-inst.lo \
+@ENABLE_EXTERN_TEMPLATE_TRUE@am__objects_3 = allocator-inst.lo \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	concept-inst.lo ext-inst.lo \
 @ENABLE_EXTERN_TEMPLATE_TRUE@	misc-inst.lo
-am__objects_5 = parallel_settings.lo
-am__objects_6 = basic_file.lo c++locale.lo $(am__objects_4) \
-	$(am__objects_5)
-am__objects_7 = bitmap_allocator.lo pool_allocator.lo mt_allocator.lo \
-	codecvt.lo complex_io.lo globals_io.lo hash_tr1.lo \
-	hashtable_tr1.lo ios_failure.lo ios_init.lo ios_locale.lo \
-	list.lo list-aux.lo list-aux-2.lo list_associated.lo \
-	list_associated-2.lo locale.lo locale_init.lo locale_facets.lo \
-	localename.lo math_stubs_float.lo math_stubs_long_double.lo \
-	stdexcept.lo strstream.lo tree.lo istream.lo istream-string.lo \
-	streambuf.lo valarray.lo $(am__objects_1) $(am__objects_3) \
-	$(am__objects_6)
-am_libc__98convenience_la_OBJECTS = $(am__objects_7)
+am__objects_4 = parallel_settings.lo
+am__objects_5 = basic_file.lo c++locale.lo $(am__objects_3) \
+	$(am__objects_4)
+am__objects_6 = bitmap_allocator.lo pool_allocator.lo mt_allocator.lo \
+	codecvt.lo complex_io.lo cow-istream-string.lo globals_io.lo \
+	hash_tr1.lo hashtable_tr1.lo ios_failure.lo ios_init.lo \
+	ios_locale.lo list.lo list-aux.lo list-aux-2.lo \
+	list_associated.lo list_associated-2.lo locale.lo \
+	locale_init.lo locale_facets.lo localename.lo \
+	math_stubs_float.lo math_stubs_long_double.lo stdexcept.lo \
+	strstream.lo tree.lo istream.lo istream-string.lo streambuf.lo \
+	valarray.lo $(am__objects_2) $(am__objects_5)
+am_libc__98convenience_la_OBJECTS = $(am__objects_6)
 libc__98convenience_la_OBJECTS = $(am_libc__98convenience_la_OBJECTS)
 AM_V_lt = $(am__v_lt_@AM_V@)
 am__v_lt_ = $(am__v_lt_@AM_DEFAULT_V@)
@@ -470,10 +469,6 @@ host_sources_extra = \
 	basic_file.cc c++locale.cc \
 	${inst_sources} ${parallel_sources}
 
-@ENABLE_DUAL_ABI_FALSE@cxx11_abi_sources = 
-@ENABLE_DUAL_ABI_TRUE@cxx11_abi_sources = \
-@ENABLE_DUAL_ABI_TRUE@	cow-istream-string.cc
-
 # XTEMPLATE_FLAGS =
 @ENABLE_EXTERN_TEMPLATE_FALSE@inst_sources = 
 
@@ -493,6 +488,7 @@ sources = \
 	mt_allocator.cc \
 	codecvt.cc \
 	complex_io.cc \
+	cow-istream-string.cc \
 	globals_io.cc \
 	hash_tr1.cc \
 	hashtable_tr1.cc \
@@ -517,7 +513,6 @@ sources = \
 	istream-string.cc \
 	streambuf.cc \
 	valarray.cc \
-	${cxx11_abi_sources} \
 	${host_sources} \
 	${host_sources_extra}
 
diff --git a/libstdc++-v3/src/c++98/cow-istream-string.cc b/libstdc++-v3/src/c++98/cow-istream-string.cc
index d90ec2a0cf3..ff406830c61 100644
--- a/libstdc++-v3/src/c++98/cow-istream-string.cc
+++ b/libstdc++-v3/src/c++98/cow-istream-string.cc
@@ -27,4 +27,8 @@
 //
 
 #define _GLIBCXX_USE_CXX11_ABI 0
-#include "istream-string.cc"
+#include <bits/c++config.h>
+
+#if ! _GLIBCXX_USE_CXX11_ABI
+# include "istream-string.cc"
+#endif
diff --git a/libstdc++-v3/src/c++98/hash_tr1.cc b/libstdc++-v3/src/c++98/hash_tr1.cc
index caa424e423f..7256d2529cf 100644
--- a/libstdc++-v3/src/c++98/hash_tr1.cc
+++ b/libstdc++-v3/src/c++98/hash_tr1.cc
@@ -28,6 +28,7 @@
 
 #include "hash-long-double-tr1-aux.cc"
 
+#if ! _GLIBCXX_USE_CXX11_ABI
 namespace std _GLIBCXX_VISIBILITY(default)
 {
   namespace tr1
@@ -57,3 +58,4 @@ namespace std _GLIBCXX_VISIBILITY(default)
 #endif
   }
 }
+#endif // ! _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++98/ios_failure.cc b/libstdc++-v3/src/c++98/ios_failure.cc
index 523d1f6a4e9..7fea41af56c 100644
--- a/libstdc++-v3/src/c++98/ios_failure.cc
+++ b/libstdc++-v3/src/c++98/ios_failure.cc
@@ -29,22 +29,24 @@
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <ios>
 
-#if _GLIBCXX_USE_DUAL_ABI && __cpp_rtti
-#include <cxxabi.h>
-#include <typeinfo>
-#endif
-
-#ifdef _GLIBCXX_USE_NLS
-# include <libintl.h>
-# define _(msgid)   gettext (msgid)
-#else
-# define _(msgid)   (msgid)
-#endif
+#if ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
+# if _GLIBCXX_USE_DUAL_ABI && __cpp_rtti
+#  include <cxxabi.h>
+#  include <typeinfo>
+# endif
+
+# ifdef _GLIBCXX_USE_NLS
+#  include <libintl.h>
+#  define _(msgid)   gettext (msgid)
+# else
+#  define _(msgid)   (msgid)
+# endif
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+# if ! _GLIBCXX_USE_CXX11_ABI
   ios_base::failure::failure(const string& __str) throw()
   : _M_msg(__str) { }
 
@@ -54,11 +56,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   const char*
   ios_base::failure::what() const throw()
   { return _M_msg.c_str(); }
+# endif
 
-#if _GLIBCXX_USE_DUAL_ABI
+# if _GLIBCXX_USE_DUAL_ABI
   // When the dual ABI is enabled __throw_ios_failure() is defined in
   // src/c++11/cxx11-ios_failure.cc
-#if __cpp_rtti
+#  if __cpp_rtti
   // If RTTI is enabled the exception type thrown will use these functions to
   // construct/destroy a gcc4-compatible ios::failure object in a buffer,
   // and to catch that object via a handler of the gcc4-compatible type.
@@ -80,9 +83,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   typedef char S[1 / (sizeof(ios::failure) <= sizeof(runtime_error))];
   typedef char A[1 / (__alignof(ios::failure) <= __alignof(runtime_error))];
   }
-#endif // __cpp_rtti
+#  endif // __cpp_rtti
 
-#else // ! _GLIBCXX_USE_DUAL_ABI
+# elif ! _GLIBCXX_USE_CXX11_ABI
 
   void
   __throw_ios_failure(const char* __s __attribute__((unused)))
@@ -92,7 +95,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   __throw_ios_failure(const char* str, int)
   { __throw_ios_failure(str); }
 
-#endif // _GLIBCXX_USE_DUAL_ABI
+# endif // _GLIBCXX_USE_DUAL_ABI
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+
+#endif // ! _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
diff --git a/libstdc++-v3/src/c++98/istream-string.cc b/libstdc++-v3/src/c++98/istream-string.cc
index 19f5f0c1a47..034cd951d6d 100644
--- a/libstdc++-v3/src/c++98/istream-string.cc
+++ b/libstdc++-v3/src/c++98/istream-string.cc
@@ -31,6 +31,16 @@
 // by another file which defines _GLIBCXX_USE_CXX11_ABI=0.
 # define _GLIBCXX_USE_CXX11_ABI 1
 #endif
+
+#if _GLIBCXX_USE_CXX11_ABI
+# define _GLIBCXX_BUILD_CXX11_ABI 1
+#else
+# define _GLIBCXX_BUILD_CXX11_ABI 0
+#endif
+
+#include <bits/c++config.h>
+
+#if _GLIBCXX_BUILD_CXX11_ABI == _GLIBCXX_USE_CXX11_ABI
 #include <istream>
 #include <string>
 
@@ -289,3 +299,4 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
+#endif // _GLIBCXX_BUILD_CXX11_ABI == _GLIBCXX_USE_CXX11_ABI
diff --git a/libstdc++-v3/src/c++98/locale_facets.cc b/libstdc++-v3/src/c++98/locale_facets.cc
index 1293a37e642..4b351b2e8ef 100644
--- a/libstdc++-v3/src/c++98/locale_facets.cc
+++ b/libstdc++-v3/src/c++98/locale_facets.cc
@@ -125,6 +125,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     return __test;
   }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   bool
   __verify_grouping(const char* __grouping, size_t __grouping_size,
 		    const string& __grouping_tmp) throw()
@@ -133,6 +134,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                                   __grouping_tmp.c_str(),
                                   __grouping_tmp.size());
   }
+#endif
 
   namespace
   {
diff --git a/libstdc++-v3/src/c++98/stdexcept.cc b/libstdc++-v3/src/c++98/stdexcept.cc
index 0a24b054ca0..786f0ff0523 100644
--- a/libstdc++-v3/src/c++98/stdexcept.cc
+++ b/libstdc++-v3/src/c++98/stdexcept.cc
@@ -26,7 +26,7 @@
 // ISO C++ 14882: 19.1  Exception classes
 //
 
-// All exception classes still use the classic COW std::string.
+// In dual abi all exception classes still use the classic COW std::string.
 #define _GLIBCXX_USE_CXX11_ABI 0
 #include <string>
 #include <stdexcept>
@@ -35,8 +35,10 @@ namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   logic_error::logic_error(const string& __arg)
   : exception(), _M_msg(__arg) { }
+#endif
 
   logic_error::~logic_error() _GLIBCXX_USE_NOEXCEPT { }
 
@@ -44,28 +46,38 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   logic_error::what() const _GLIBCXX_USE_NOEXCEPT
   { return _M_msg.c_str(); }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   domain_error::domain_error(const string& __arg)
   : logic_error(__arg) { }
+#endif
 
   domain_error::~domain_error() _GLIBCXX_USE_NOEXCEPT { }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   invalid_argument::invalid_argument(const string& __arg)
   : logic_error(__arg) { }
+#endif
 
   invalid_argument::~invalid_argument() _GLIBCXX_USE_NOEXCEPT { }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   length_error::length_error(const string& __arg)
   : logic_error(__arg) { }
+#endif
 
   length_error::~length_error() _GLIBCXX_USE_NOEXCEPT { }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   out_of_range::out_of_range(const string& __arg)
   : logic_error(__arg) { }
+#endif
 
   out_of_range::~out_of_range() _GLIBCXX_USE_NOEXCEPT { }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   runtime_error::runtime_error(const string& __arg)
   : exception(), _M_msg(__arg) { }
+#endif
 
   runtime_error::~runtime_error() _GLIBCXX_USE_NOEXCEPT { }
 
@@ -73,18 +85,24 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   runtime_error::what() const _GLIBCXX_USE_NOEXCEPT
   { return _M_msg.c_str(); }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   range_error::range_error(const string& __arg)
   : runtime_error(__arg) { }
+#endif
 
   range_error::~range_error() _GLIBCXX_USE_NOEXCEPT { }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   overflow_error::overflow_error(const string& __arg)
   : runtime_error(__arg) { }
+#endif
 
   overflow_error::~overflow_error() _GLIBCXX_USE_NOEXCEPT { }
 
+#if ! _GLIBCXX_USE_CXX11_ABI
   underflow_error::underflow_error(const string& __arg)
   : runtime_error(__arg) { }
+#endif
 
   underflow_error::~underflow_error() _GLIBCXX_USE_NOEXCEPT { }