Index: libcxx/include/ios
===================================================================
--- libcxx/include/ios
+++ libcxx/include/ios
@@ -425,6 +425,16 @@
     virtual ~failure() throw();
 };
 
+_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
+void __throw_failure(char const* __msg) {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    throw ios_base::failure(__msg);
+#else
+    ((void)__msg);
+    _VSTD::abort();
+#endif
+}
+
 class _LIBCPP_TYPE_VIS ios_base::Init
 {
 public:
Index: libcxx/include/unordered_map
===================================================================
--- libcxx/include/unordered_map
+++ libcxx/include/unordered_map
@@ -1602,10 +1602,8 @@
 unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k)
 {
     iterator __i = find(__k);
-#ifndef _LIBCPP_NO_EXCEPTIONS
     if (__i == end())
-        throw out_of_range("unordered_map::at: key not found");
-#endif  // _LIBCPP_NO_EXCEPTIONS
+        __throw_out_of_range("unordered_map::at: key not found");
     return __i->second;
 }
 
@@ -1614,10 +1612,8 @@
 unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k) const
 {
     const_iterator __i = find(__k);
-#ifndef _LIBCPP_NO_EXCEPTIONS
     if (__i == end())
-        throw out_of_range("unordered_map::at: key not found");
-#endif  // _LIBCPP_NO_EXCEPTIONS
+        __throw_out_of_range("unordered_map::at: key not found");
     return __i->second;
 }
 
Index: libcxx/src/hash.cpp
===================================================================
--- libcxx/src/hash.cpp
+++ libcxx/src/hash.cpp
@@ -153,12 +153,8 @@
 typename enable_if<_Sz == 4, void>::type
 __check_for_overflow(size_t N)
 {
-#ifndef _LIBCPP_NO_EXCEPTIONS
     if (N > 0xFFFFFFFB)
-        throw overflow_error("__next_prime overflow");
-#else
-    (void)N;
-#endif
+        __throw_overflow_error("__next_prime overflow");
 }
 
 template <size_t _Sz = sizeof(size_t)>
@@ -166,12 +162,8 @@
 typename enable_if<_Sz == 8, void>::type
 __check_for_overflow(size_t N)
 {
-#ifndef _LIBCPP_NO_EXCEPTIONS
     if (N > 0xFFFFFFFFFFFFFFC5ull)
-        throw overflow_error("__next_prime overflow");
-#else
-    (void)N;
-#endif
+        __throw_overflow_error("__next_prime overflow");
 }
 
 size_t
Index: libcxx/src/ios.cpp
===================================================================
--- libcxx/src/ios.cpp
+++ libcxx/src/ios.cpp
@@ -266,10 +266,9 @@
         __rdstate_ = state;
     else
         __rdstate_ = state | badbit;
-#ifndef _LIBCPP_NO_EXCEPTIONS
+
     if (((state | (__rdbuf_ ? goodbit : badbit)) & __exceptions_) != 0)
-        throw failure("ios_base::clear");
-#endif  // _LIBCPP_NO_EXCEPTIONS
+        __throw_failure("ios_base::clear");
 }
 
 // init
@@ -309,35 +308,27 @@
     {
         size_t newesize = sizeof(event_callback) * rhs.__event_size_;
         new_callbacks.reset(static_cast<event_callback*>(malloc(newesize)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
         if (!new_callbacks)
-            throw bad_alloc();
-#endif  // _LIBCPP_NO_EXCEPTIONS
+            __throw_bad_alloc();
 
         size_t newisize = sizeof(int) * rhs.__event_size_;
         new_ints.reset(static_cast<int *>(malloc(newisize)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
         if (!new_ints)
-            throw bad_alloc();
-#endif  // _LIBCPP_NO_EXCEPTIONS
+            __throw_bad_alloc();
     }
     if (__iarray_cap_ < rhs.__iarray_size_)
     {
         size_t newsize = sizeof(long) * rhs.__iarray_size_;
         new_longs.reset(static_cast<long*>(malloc(newsize)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
         if (!new_longs)
-            throw bad_alloc();
-#endif  // _LIBCPP_NO_EXCEPTIONS
+            __throw_bad_alloc();
     }
     if (__parray_cap_ < rhs.__parray_size_)
     {
         size_t newsize = sizeof(void*) * rhs.__parray_size_;
         new_pointers.reset(static_cast<void**>(malloc(newsize)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
         if (!new_pointers)
-            throw bad_alloc();
-#endif  // _LIBCPP_NO_EXCEPTIONS
+            __throw_bad_alloc();
     }
     // Got everything we need.  Copy everything but __rdstate_, __rdbuf_ and __exceptions_
     __fmtflags_ = rhs.__fmtflags_;
Index: libcxx/src/locale.cpp
===================================================================
--- libcxx/src/locale.cpp
+++ libcxx/src/locale.cpp
@@ -468,10 +468,8 @@
 const locale::facet*
 locale::__imp::use_facet(long id) const
 {
-#ifndef _LIBCPP_NO_EXCEPTIONS
     if (!has_facet(id))
-        throw bad_cast();
-#endif  // _LIBCPP_NO_EXCEPTIONS
+        __throw_bad_cast();
     return facets_[static_cast<size_t>(id)];
 }
 
@@ -537,12 +535,8 @@
 }
 
 locale::locale(const char* name)
-#ifndef _LIBCPP_NO_EXCEPTIONS
     : __locale_(name ? new __imp(name)
-                     : throw runtime_error("locale constructed with null"))
-#else  // _LIBCPP_NO_EXCEPTIONS
-    : __locale_(new __imp(name))
-#endif
+                     : (__throw_runtime_error("locale constructed with null"), (__imp*)0))
 {
     __locale_->__add_shared();
 }
@@ -554,12 +548,8 @@
 }
 
 locale::locale(const locale& other, const char* name, category c)
-#ifndef _LIBCPP_NO_EXCEPTIONS
     : __locale_(name ? new __imp(*other.__locale_, name, c)
-                     : throw runtime_error("locale constructed with null"))
-#else  // _LIBCPP_NO_EXCEPTIONS
-    : __locale_(new __imp(*other.__locale_, name, c))
-#endif
+                     : (__throw_runtime_error("locale constructed with null"), (__imp*)0))
 {
     __locale_->__add_shared();
 }