Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -55,6 +55,8 @@
 option(LIBCXX_ENABLE_CXX1Y "Enable -std=c++1y and use of c++1y language features if the compiler supports it." OFF)
 option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
 option(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE "Build libc++ with support for the global filesystem namespace." ON)
+option(LIBCXX_ENABLE_STDIN "Build libc++ with support for stdin/std::cin." ON)
+option(LIBCXX_ENABLE_STDOUT "Build libc++ with support for stdout/std::cout." ON)
 option(LIBCXX_ENABLE_THREADS "Build libc++ with support for threads." ON)
 option(LIBCXX_BUILD_32_BITS "Build 32 bit libc++" OFF)
 option(LIBCXX_ENABLE_MONOTONIC_CLOCK
@@ -238,6 +240,16 @@
   add_definitions(-D_LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE)
 endif()
 
+# LIBCXX_ENABLE_STDIN configuration
+if (NOT LIBCXX_ENABLE_STDIN)
+  add_definitions(-D_LIBCPP_HAS_NO_STDIN)
+endif()
+
+# LIBCXX_ENABLE_STDOUT configuration
+if (NOT LIBCXX_ENABLE_STDOUT)
+  add_definitions(-D_LIBCPP_HAS_NO_STDOUT)
+endif()
+
 # LIBCXX_ENABLE_THREADS configuration
 if (NOT LIBCXX_ENABLE_THREADS)
   add_definitions(-D_LIBCPP_HAS_NO_THREADS)
Index: include/__config
===================================================================
--- include/__config
+++ include/__config
@@ -732,6 +732,13 @@
 #define _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
 #endif
 
+// CloudABI is intended for running networked services. Processes do not
+// have standard input and output channels.
+#ifdef __CloudABI__
+#define _LIBCPP_HAS_NO_STDIN
+#define _LIBCPP_HAS_NO_STDOUT
+#endif
+
 #if defined(__ANDROID__) || defined(__CloudABI__)
 #define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
 #endif
Index: include/cstdio
===================================================================
--- include/cstdio
+++ include/cstdio
@@ -144,34 +144,20 @@
 using ::fpos_t;
 using ::size_t;
 
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-using ::remove;
-using ::rename;
-using ::tmpfile;
-using ::tmpnam;
-#endif
 using ::fclose;
 using ::fflush;
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-using ::fopen;
-using ::freopen;
-#endif
 using ::setbuf;
 using ::setvbuf;
 using ::fprintf;
 using ::fscanf;
-using ::printf;
-using ::scanf;
 using ::snprintf;
 using ::sprintf;
 using ::sscanf;
 #ifndef _LIBCPP_MSVCRT
 using ::vfprintf;
 using ::vfscanf;
-using ::vscanf;
 using ::vsscanf;
 #endif // _LIBCPP_MSVCRT
-using ::vprintf;
 using ::vsnprintf;
 using ::vsprintf;
 using ::fgetc;
@@ -179,13 +165,7 @@
 using ::fputc;
 using ::fputs;
 using ::getc;
-using ::getchar;
-#if _LIBCPP_STD_VER <= 11
-using ::gets;
-#endif
 using ::putc;
-using ::putchar;
-using ::puts;
 using ::ungetc;
 using ::fread;
 using ::fwrite;
@@ -199,6 +179,31 @@
 using ::ferror;
 using ::perror;
 
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+using ::fopen;
+using ::freopen;
+using ::remove;
+using ::rename;
+using ::tmpfile;
+using ::tmpnam;
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDIN
+using ::getchar;
+#if _LIBCPP_STD_VER <= 11
+using ::gets;
+#endif
+using ::scanf;
+using ::vscanf;
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDOUT
+using ::printf;
+using ::putchar;
+using ::puts;
+using ::vprintf;
+#endif
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_CSTDIO
Index: include/cwchar
===================================================================
--- include/cwchar
+++ include/cwchar
@@ -126,24 +126,18 @@
 using ::swprintf;
 using ::vfwprintf;
 using ::vswprintf;
-using ::vwprintf;
 #ifndef _LIBCPP_MSVCRT
 using ::swscanf;
 using ::vfwscanf;
 using ::vswscanf;
-using ::vwscanf;
 #endif // _LIBCPP_MSVCRT
-using ::wprintf;
-using ::wscanf;
 using ::fgetwc;
 using ::fgetws;
 using ::fputwc;
 using ::fputws;
 using ::fwide;
 using ::getwc;
-using ::getwchar;
 using ::putwc;
-using ::putwchar;
 using ::ungetwc;
 using ::wcstod;
 #ifndef _LIBCPP_MSVCRT
@@ -212,6 +206,20 @@
 using ::mbsrtowcs;
 using ::wcsrtombs;
 
+#ifndef _LIBCPP_HAS_NO_STDIN
+using ::getwchar;
+#ifndef _LIBCPP_MSVCRT
+using ::vwscanf;
+#endif // _LIBCPP_MSVCRT
+using ::wscanf;
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDOUT
+using ::putwchar;
+using ::vwprintf;
+using ::wprintf;
+#endif
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_CWCHAR
Index: include/iostream
===================================================================
--- include/iostream
+++ include/iostream
@@ -46,13 +46,17 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
+#ifndef _LIBCPP_HAS_NO_STDIN
 extern _LIBCPP_FUNC_VIS istream cin;
-extern _LIBCPP_FUNC_VIS ostream cout;
-extern _LIBCPP_FUNC_VIS ostream cerr;
-extern _LIBCPP_FUNC_VIS ostream clog;
 extern _LIBCPP_FUNC_VIS wistream wcin;
+#endif
+#ifndef _LIBCPP_HAS_NO_STDOUT
+extern _LIBCPP_FUNC_VIS ostream cout;
 extern _LIBCPP_FUNC_VIS wostream wcout;
+#endif
+extern _LIBCPP_FUNC_VIS ostream cerr;
 extern _LIBCPP_FUNC_VIS wostream wcerr;
+extern _LIBCPP_FUNC_VIS ostream clog;
 extern _LIBCPP_FUNC_VIS wostream wclog;
 
 _LIBCPP_END_NAMESPACE_STD
Index: src/iostream.cpp
===================================================================
--- src/iostream.cpp
+++ src/iostream.cpp
@@ -13,55 +13,75 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-static mbstate_t state_types[6] = {};
-
+#ifndef _LIBCPP_HAS_NO_STDIN
+_ALIGNAS_TYPE (istream)  _LIBCPP_FUNC_VIS char cin [sizeof(istream)];
 _ALIGNAS_TYPE (__stdinbuf<char> ) static char __cin [sizeof(__stdinbuf <char>)];
-_ALIGNAS_TYPE (__stdoutbuf<char>) static char __cout[sizeof(__stdoutbuf<char>)];
-_ALIGNAS_TYPE (__stdoutbuf<char>) static char __cerr[sizeof(__stdoutbuf<char>)];
+static mbstate_t mb_cin;
+_ALIGNAS_TYPE (wistream) _LIBCPP_FUNC_VIS char wcin [sizeof(wistream)];
 _ALIGNAS_TYPE (__stdinbuf<wchar_t> ) static char __wcin [sizeof(__stdinbuf <wchar_t>)];
-_ALIGNAS_TYPE (__stdoutbuf<wchar_t>) static char __wcout[sizeof(__stdoutbuf<wchar_t>)];
-_ALIGNAS_TYPE (__stdoutbuf<wchar_t>) static char __wcerr[sizeof(__stdoutbuf<wchar_t>)];
+static mbstate_t mb_wcin;
+#endif
 
-_ALIGNAS_TYPE (istream)  _LIBCPP_FUNC_VIS char cin [sizeof(istream)];
+#ifndef _LIBCPP_HAS_NO_STDOUT
 _ALIGNAS_TYPE (ostream)  _LIBCPP_FUNC_VIS char cout[sizeof(ostream)];
-_ALIGNAS_TYPE (ostream)  _LIBCPP_FUNC_VIS char cerr[sizeof(ostream)];
-_ALIGNAS_TYPE (ostream)  _LIBCPP_FUNC_VIS char clog[sizeof(ostream)];
-_ALIGNAS_TYPE (wistream) _LIBCPP_FUNC_VIS char wcin [sizeof(wistream)];
+_ALIGNAS_TYPE (__stdoutbuf<char>) static char __cout[sizeof(__stdoutbuf<char>)];
+static mbstate_t mb_cout;
 _ALIGNAS_TYPE (wostream) _LIBCPP_FUNC_VIS char wcout[sizeof(wostream)];
+_ALIGNAS_TYPE (__stdoutbuf<wchar_t>) static char __wcout[sizeof(__stdoutbuf<wchar_t>)];
+static mbstate_t mb_wcout;
+#endif
+
+_ALIGNAS_TYPE (ostream)  _LIBCPP_FUNC_VIS char cerr[sizeof(ostream)];
+_ALIGNAS_TYPE (__stdoutbuf<char>) static char __cerr[sizeof(__stdoutbuf<char>)];
+static mbstate_t mb_cerr;
 _ALIGNAS_TYPE (wostream) _LIBCPP_FUNC_VIS char wcerr[sizeof(wostream)];
+_ALIGNAS_TYPE (__stdoutbuf<wchar_t>) static char __wcerr[sizeof(__stdoutbuf<wchar_t>)];
+static mbstate_t mb_wcerr;
+
+_ALIGNAS_TYPE (ostream)  _LIBCPP_FUNC_VIS char clog[sizeof(ostream)];
 _ALIGNAS_TYPE (wostream) _LIBCPP_FUNC_VIS char wclog[sizeof(wostream)];
 
 ios_base::Init __start_std_streams;
 
 ios_base::Init::Init()
 {
-    istream* cin_ptr  = ::new(cin)  istream(::new(__cin)  __stdinbuf <char>(stdin, state_types+0) );
-    ostream* cout_ptr = ::new(cout) ostream(::new(__cout) __stdoutbuf<char>(stdout, state_types+1));
-    ostream* cerr_ptr = ::new(cerr) ostream(::new(__cerr) __stdoutbuf<char>(stderr, state_types+2));
+#ifndef _LIBCPP_HAS_NO_STDIN
+    istream* cin_ptr  = ::new(cin)  istream(::new(__cin)  __stdinbuf <char>(stdin, &mb_cin));
+    wistream* wcin_ptr  = ::new(wcin)  wistream(::new(__wcin)  __stdinbuf <wchar_t>(stdin, &mb_wcin));
+#endif
+#ifndef _LIBCPP_HAS_NO_STDOUT
+    ostream* cout_ptr = ::new(cout) ostream(::new(__cout) __stdoutbuf<char>(stdout, &mb_cout));
+    wostream* wcout_ptr = ::new(wcout) wostream(::new(__wcout) __stdoutbuf<wchar_t>(stdout, &mb_wcout));
+#endif
+    ostream* cerr_ptr = ::new(cerr) ostream(::new(__cerr) __stdoutbuf<char>(stderr, &mb_cerr));
                         ::new(clog) ostream(cerr_ptr->rdbuf());
-    cin_ptr->tie(cout_ptr);
-    _VSTD::unitbuf(*cerr_ptr);
-    cerr_ptr->tie(cout_ptr);
-
-    wistream* wcin_ptr  = ::new(wcin)  wistream(::new(__wcin)  __stdinbuf <wchar_t>(stdin, state_types+3) );
-    wostream* wcout_ptr = ::new(wcout) wostream(::new(__wcout) __stdoutbuf<wchar_t>(stdout, state_types+4));
-    wostream* wcerr_ptr = ::new(wcerr) wostream(::new(__wcerr) __stdoutbuf<wchar_t>(stderr, state_types+5));
+    wostream* wcerr_ptr = ::new(wcerr) wostream(::new(__wcerr) __stdoutbuf<wchar_t>(stderr, &mb_wcerr));
                           ::new(wclog) wostream(wcerr_ptr->rdbuf());
+
+#if !defined(_LIBCPP_HAS_NO_STDIN) && !defined(_LIBCPP_HAS_NO_STDOUT)
+    cin_ptr->tie(cout_ptr);
     wcin_ptr->tie(wcout_ptr);
+#endif
+    _VSTD::unitbuf(*cerr_ptr);
     _VSTD::unitbuf(*wcerr_ptr);
+#ifndef _LIBCPP_HAS_NO_STDOUT
+    cerr_ptr->tie(cout_ptr);
     wcerr_ptr->tie(wcout_ptr);
+#endif
 }
 
 ios_base::Init::~Init()
 {
+#ifndef _LIBCPP_HAS_NO_STDOUT
     ostream* cout_ptr = reinterpret_cast<ostream*>(cout);
-    ostream* clog_ptr = reinterpret_cast<ostream*>(clog);
+    wostream* wcout_ptr = reinterpret_cast<wostream*>(wcout);
     cout_ptr->flush();
-    clog_ptr->flush();
+    wcout_ptr->flush();
+#endif
 
-    wostream* wcout_ptr = reinterpret_cast<wostream*>(wcout);
+    ostream* clog_ptr = reinterpret_cast<ostream*>(clog);
     wostream* wclog_ptr = reinterpret_cast<wostream*>(wclog);
-    wcout_ptr->flush();
+    clog_ptr->flush();
     wclog_ptr->flush();
 }
 
Index: test/CMakeLists.txt
===================================================================
--- test/CMakeLists.txt
+++ test/CMakeLists.txt
@@ -43,6 +43,8 @@
   pythonize_bool(LIBCXX_ENABLE_SHARED)
   pythonize_bool(LIBCXX_BUILD_32_BITS)
   pythonize_bool(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE)
+  pythonize_bool(LIBCXX_ENABLE_STDIN)
+  pythonize_bool(LIBCXX_ENABLE_STDOUT)
   pythonize_bool(LIBCXX_ENABLE_THREADS)
   pythonize_bool(LIBCXX_ENABLE_MONOTONIC_CLOCK)
   # The tests shouldn't link to any ABI library when it has been linked into
Index: test/libcxx/test/config.py
===================================================================
--- test/libcxx/test/config.py
+++ test/libcxx/test/config.py
@@ -348,6 +348,8 @@
         self.configure_compile_flags_exceptions()
         self.configure_compile_flags_rtti()
         self.configure_compile_flags_no_global_filesystem_namespace()
+        self.configure_compile_flags_no_stdin()
+        self.configure_compile_flags_no_stdout()
         enable_32bit = self.get_lit_bool('enable_32bit', False)
         if enable_32bit:
             self.cxx.flags += ['-m32']
@@ -405,6 +407,18 @@
             self.cxx.compile_flags += [
                 '-D_LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE']
 
+    def configure_compile_flags_no_stdin(self):
+        enable_stdin = self.get_lit_bool('enable_stdin', True)
+        if not enable_stdin:
+            self.config.available_features.add('libcpp-has-no-stdin')
+            self.cxx.compile_flags += ['-D_LIBCPP_HAS_NO_STDIN']
+
+    def configure_compile_flags_no_stdout(self):
+        enable_stdout = self.get_lit_bool('enable_stdout', True)
+        if not enable_stdout:
+            self.config.available_features.add('libcpp-has-no-stdout')
+            self.cxx.compile_flags += ['-D_LIBCPP_HAS_NO_STDOUT']
+
     def configure_compile_flags_no_threads(self):
         self.cxx.compile_flags += ['-D_LIBCPP_HAS_NO_THREADS']
         self.config.available_features.add('libcpp-has-no-threads')
Index: test/lit.site.cfg.in
===================================================================
--- test/lit.site.cfg.in
+++ test/lit.site.cfg.in
@@ -9,6 +9,8 @@
 config.enable_shared            = "@LIBCXX_ENABLE_SHARED@"
 config.enable_32bit             = "@LIBCXX_BUILD_32_BITS@"
 config.enable_global_filesystem_namespace = "@LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE@"
+config.enable_stdin             = "@LIBCXX_ENABLE_STDIN@"
+config.enable_stdout            = "@LIBCXX_ENABLE_STDOUT@"
 config.enable_threads           = "@LIBCXX_ENABLE_THREADS@"
 config.enable_monotonic_clock   = "@LIBCXX_ENABLE_MONOTONIC_CLOCK@"
 config.cxx_abi                  = "@LIBCXX_CXX_ABI_LIBNAME@"
Index: test/std/input.output/file.streams/c.files/cstdio.pass.cpp
===================================================================
--- test/std/input.output/file.streams/c.files/cstdio.pass.cpp
+++ test/std/input.output/file.streams/c.files/cstdio.pass.cpp
@@ -88,31 +88,17 @@
     std::size_t s = 0;
     char* cp = 0;
     std::va_list va;
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    static_assert((std::is_same<decltype(std::remove("")), int>::value), "");
-    static_assert((std::is_same<decltype(std::rename("","")), int>::value), "");
-    static_assert((std::is_same<decltype(std::tmpfile()), std::FILE*>::value), "");
-    static_assert((std::is_same<decltype(std::tmpnam(cp)), char*>::value), "");
-#endif
     static_assert((std::is_same<decltype(std::fclose(fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::fflush(fp)), int>::value), "");
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    static_assert((std::is_same<decltype(std::fopen("", "")), std::FILE*>::value), "");
-    static_assert((std::is_same<decltype(std::freopen("", "", fp)), std::FILE*>::value), "");
-#endif
     static_assert((std::is_same<decltype(std::setbuf(fp,cp)), void>::value), "");
     static_assert((std::is_same<decltype(std::vfprintf(fp,"",va)), int>::value), "");
     static_assert((std::is_same<decltype(std::fprintf(fp," ")), int>::value), "");
     static_assert((std::is_same<decltype(std::fscanf(fp,"")), int>::value), "");
-    static_assert((std::is_same<decltype(std::printf(" ")), int>::value), "");
-    static_assert((std::is_same<decltype(std::scanf(" ")), int>::value), "");
     static_assert((std::is_same<decltype(std::snprintf(cp,0," ")), int>::value), "");
     static_assert((std::is_same<decltype(std::sprintf(cp," ")), int>::value), "");
     static_assert((std::is_same<decltype(std::sscanf("","")), int>::value), "");
     static_assert((std::is_same<decltype(std::vfprintf(fp,"",va)), int>::value), "");
     static_assert((std::is_same<decltype(std::vfscanf(fp,"",va)), int>::value), "");
-    static_assert((std::is_same<decltype(std::vprintf(" ",va)), int>::value), "");
-    static_assert((std::is_same<decltype(std::vscanf("",va)), int>::value), "");
     static_assert((std::is_same<decltype(std::vsnprintf(cp,0," ",va)), int>::value), "");
     static_assert((std::is_same<decltype(std::vsprintf(cp," ",va)), int>::value), "");
     static_assert((std::is_same<decltype(std::vsscanf("","",va)), int>::value), "");
@@ -121,13 +107,7 @@
     static_assert((std::is_same<decltype(std::fputc(0,fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::fputs("",fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::getc(fp)), int>::value), "");
-    static_assert((std::is_same<decltype(std::getchar()), int>::value), "");
-#if _LIBCPP_STD_VER <= 11
-    static_assert((std::is_same<decltype(std::gets(cp)), char*>::value), "");
-#endif
     static_assert((std::is_same<decltype(std::putc(0,fp)), int>::value), "");
-    static_assert((std::is_same<decltype(std::putchar(0)), int>::value), "");
-    static_assert((std::is_same<decltype(std::puts("")), int>::value), "");
     static_assert((std::is_same<decltype(std::ungetc(0,fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::fread((void*)0,0,0,fp)), std::size_t>::value), "");
     static_assert((std::is_same<decltype(std::fwrite((const void*)0,0,0,fp)), std::size_t>::value), "");
@@ -140,4 +120,29 @@
     static_assert((std::is_same<decltype(std::feof(fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::ferror(fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::perror("")), void>::value), "");
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    static_assert((std::is_same<decltype(std::fopen("", "")), std::FILE*>::value), "");
+    static_assert((std::is_same<decltype(std::freopen("", "", fp)), std::FILE*>::value), "");
+    static_assert((std::is_same<decltype(std::remove("")), int>::value), "");
+    static_assert((std::is_same<decltype(std::rename("","")), int>::value), "");
+    static_assert((std::is_same<decltype(std::tmpfile()), std::FILE*>::value), "");
+    static_assert((std::is_same<decltype(std::tmpnam(cp)), char*>::value), "");
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDIN
+    static_assert((std::is_same<decltype(std::getchar()), int>::value), "");
+#if _LIBCPP_STD_VER <= 11
+    static_assert((std::is_same<decltype(std::gets(cp)), char*>::value), "");
+#endif
+    static_assert((std::is_same<decltype(std::scanf(" ")), int>::value), "");
+    static_assert((std::is_same<decltype(std::vscanf("",va)), int>::value), "");
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDOUT
+    static_assert((std::is_same<decltype(std::printf(" ")), int>::value), "");
+    static_assert((std::is_same<decltype(std::putchar(0)), int>::value), "");
+    static_assert((std::is_same<decltype(std::puts("")), int>::value), "");
+    static_assert((std::is_same<decltype(std::vprintf(" ",va)), int>::value), "");
+#endif
 }
Index: test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp
===================================================================
--- test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp
+++ test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp
@@ -19,7 +19,11 @@
 #if 0
     std::cerr << "Hello World!\n";
 #else
+#ifdef _LIBCPP_HAS_NO_STDOUT
+    assert(std::cerr.tie() == NULL);
+#else
     assert(std::cerr.tie() == &std::cout);
+#endif
     assert(std::cerr.flags() & std::ios_base::unitbuf);
 #endif  // 0
 }
Index: test/std/input.output/iostream.objects/narrow.stream.objects/cin.pass.cpp
===================================================================
--- test/std/input.output/iostream.objects/narrow.stream.objects/cin.pass.cpp
+++ test/std/input.output/iostream.objects/narrow.stream.objects/cin.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: libcpp-has-no-stdin
+
 // <iostream>
 
 // istream cin;
@@ -23,6 +25,11 @@
     std::cin >> i;
     std::cout << "The number is : " << i << '\n';
 #else  // 0
+    (void)std::cin;
+#ifdef _LIBCPP_HAS_NO_STDOUT
+    assert(std::cin.tie() == NULL);
+#else
     assert(std::cin.tie() == &std::cout);
 #endif
+#endif
 }
Index: test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp
===================================================================
--- test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp
+++ test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: libcpp-has-no-stdout
+
 // <iostream>
 
 // istream cout;
Index: test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp
===================================================================
--- test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp
+++ test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp
@@ -19,7 +19,11 @@
 #if 0
     std::wcerr << L"Hello World!\n";
 #else
+#ifdef _LIBCPP_HAS_NO_STDOUT
+    assert(std::wcerr.tie() == NULL);
+#else
     assert(std::wcerr.tie() == &std::wcout);
+#endif
     assert(std::wcerr.flags() & std::ios_base::unitbuf);
 #endif  // 0
 }
Index: test/std/input.output/iostream.objects/wide.stream.objects/wcin.pass.cpp
===================================================================
--- test/std/input.output/iostream.objects/wide.stream.objects/wcin.pass.cpp
+++ test/std/input.output/iostream.objects/wide.stream.objects/wcin.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: libcpp-has-no-stdin
+
 // <iostream>
 
 // istream wcin;
@@ -23,6 +25,11 @@
     std::wcin >> i;
     std::wcout << L"The number is : " << i << L'\n';
 #else  // 0
+    (void)std::wcin;
+#ifdef _LIBCPP_HAS_NO_STDOUT
+    assert(std::wcin.tie() == NULL);
+#else
     assert(std::wcin.tie() == &std::wcout);
 #endif
+#endif
 }
Index: test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp
===================================================================
--- test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp
+++ test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: libcpp-has-no-stdout
+
 // <iostream>
 
 // istream wcout;
Index: test/std/strings/c.strings/cwchar.pass.cpp
===================================================================
--- test/std/strings/c.strings/cwchar.pass.cpp
+++ test/std/strings/c.strings/cwchar.pass.cpp
@@ -50,19 +50,13 @@
     static_assert((std::is_same<decltype(std::vfwscanf(fp, L"", va)), int>::value), "");
     static_assert((std::is_same<decltype(std::vswprintf(ws, s, L"", va)), int>::value), "");
     static_assert((std::is_same<decltype(std::vswscanf(L"", L"", va)), int>::value), "");
-    static_assert((std::is_same<decltype(std::vwprintf(L"", va)), int>::value), "");
-    static_assert((std::is_same<decltype(std::vwscanf(L"", va)), int>::value), "");
-    static_assert((std::is_same<decltype(std::wprintf(L"")), int>::value), "");
-    static_assert((std::is_same<decltype(std::wscanf(L"")), int>::value), "");
     static_assert((std::is_same<decltype(std::fgetwc(fp)), std::wint_t>::value), "");
     static_assert((std::is_same<decltype(std::fgetws(ws, 0, fp)), wchar_t*>::value), "");
     static_assert((std::is_same<decltype(std::fputwc(L' ', fp)), std::wint_t>::value), "");
     static_assert((std::is_same<decltype(std::fputws(L"", fp)), int>::value), "");
     static_assert((std::is_same<decltype(std::fwide(fp, 0)), int>::value), "");
     static_assert((std::is_same<decltype(std::getwc(fp)), std::wint_t>::value), "");
-    static_assert((std::is_same<decltype(std::getwchar()), std::wint_t>::value), "");
     static_assert((std::is_same<decltype(std::putwc(L' ', fp)), std::wint_t>::value), "");
-    static_assert((std::is_same<decltype(std::putwchar(L' ')), std::wint_t>::value), "");
     static_assert((std::is_same<decltype(std::ungetwc(L' ', fp)), std::wint_t>::value), "");
     static_assert((std::is_same<decltype(std::wcstod(L"", (wchar_t**)0)), double>::value), "");
     static_assert((std::is_same<decltype(std::wcstof(L"", (wchar_t**)0)), float>::value), "");
@@ -106,4 +100,16 @@
     static_assert((std::is_same<decltype(std::wcrtomb(ns, L' ', &mb)), std::size_t>::value), "");
     static_assert((std::is_same<decltype(std::mbsrtowcs(ws, (const char**)0, s, &mb)), std::size_t>::value), "");
     static_assert((std::is_same<decltype(std::wcsrtombs(ns, (const wchar_t**)0, s, &mb)), std::size_t>::value), "");
+
+#ifndef _LIBCPP_HAS_NO_STDIN
+    static_assert((std::is_same<decltype(std::getwchar()), std::wint_t>::value), "");
+    static_assert((std::is_same<decltype(std::vwscanf(L"", va)), int>::value), "");
+    static_assert((std::is_same<decltype(std::wscanf(L"")), int>::value), "");
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDOUT
+    static_assert((std::is_same<decltype(std::putwchar(L' ')), std::wint_t>::value), "");
+    static_assert((std::is_same<decltype(std::vwprintf(L"", va)), int>::value), "");
+    static_assert((std::is_same<decltype(std::wprintf(L"")), int>::value), "");
+#endif
 }