Make the presence of stdin and stdout optional.

The idea behind Nuxi CloudABI is that it is targeted at (but not limited to)
running networked services in a sandboxed environment. The model behind stdin,
stdout and stderr is strongly focused on interactive tools in a command shell.
CloudABI does not support the notion of stdin and stdout, as 'standard
input/output' does not apply to services. The concept of stderr does makes
sense though, as services do need some mechanism to log error messages in a
uniform way.

This patch extends libc++ in such a way that std::cin and std::cout and the
associated <cstdio>/<cwchar> functions can be disabled through the flags
_LIBCPP_HAS_NO_STDIN and _LIBCPP_HAS_NO_STDOUT, respectively. At the same time
it attempts to clean up src/iostream.cpp a bit. Instead of using a single array
of mbstate_t objects and hardcoding the array indices, it creates separate
objects that declared next to the iostream objects and their buffers. The code
is also restructured by interleaving the construction and setup of c* and wc*
objects. That way it is more obvious that this is done identically.

The c* and wc* objects already have separate unit tests. Make use of this fact
by adding XFAILs in case libcpp-has-no-std* is set. That way the tests work in
both directions. If stdin or stdout is disabled, these tests will therefore
test for the absence of c* and wc*.

Differential Revision:	http://reviews.llvm.org/D8340

llvm-svn: 233275

7 files changed, 49 insertions, 20 deletions

diff --git a/libcxx/test/std/input.output/file.streams/c.files/cstdio.pass.cpp b/libcxx/test/std/input.output/file.streams/c.files/cstdio.pass.cpp
index 2ea09bc7bec..ec4ad8a3bbc 100644
--- a/libcxx/test/std/input.output/file.streams/c.files/cstdio.pass.cpp
+++ b/libcxx/test/std/input.output/file.streams/c.files/cstdio.pass.cpp
@@ -88,31 +88,17 @@ int main()
     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 @@ int main()
     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 @@ int main()
     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
 }
diff --git a/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp b/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp
index 9206d173fc0..cdf53f86277 100644
--- a/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cerr.pass.cpp
@@ -19,7 +19,11 @@ int main()
 #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
 }
diff --git a/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cin.pass.cpp b/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cin.pass.cpp
index 3481598aed9..1ce04ffb156 100644
--- a/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cin.pass.cpp
+++ b/libcxx/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 +25,10 @@ int main()
     std::cin >> i;
     std::cout << "The number is : " << i << '\n';
 #else  // 0
+#ifdef _LIBCPP_HAS_NO_STDOUT
+    assert(std::cin.tie() == NULL);
+#else
     assert(std::cin.tie() == &std::cout);
 #endif
+#endif
 }
diff --git a/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp b/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp
index 6000ae274b9..e5887e1625d 100644
--- a/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.objects/narrow.stream.objects/cout.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: libcpp-has-no-stdout
+
 // <iostream>
 
 // istream cout;
diff --git a/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp b/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp
index 19a1dcdcdb4..b050781671e 100644
--- a/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcerr.pass.cpp
@@ -19,7 +19,11 @@ int main()
 #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
 }
diff --git a/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcin.pass.cpp b/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcin.pass.cpp
index 90a56685a67..6abd6afa81c 100644
--- a/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcin.pass.cpp
+++ b/libcxx/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 +25,10 @@ int main()
     std::wcin >> i;
     std::wcout << L"The number is : " << i << L'\n';
 #else  // 0
+#ifdef _LIBCPP_HAS_NO_STDOUT
+    assert(std::wcin.tie() == NULL);
+#else
     assert(std::wcin.tie() == &std::wcout);
 #endif
+#endif
 }
diff --git a/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp b/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp
index 7a546aa528d..6543e0aa56a 100644
--- a/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp
+++ b/libcxx/test/std/input.output/iostream.objects/wide.stream.objects/wcout.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: libcpp-has-no-stdout
+
 // <iostream>
 
 // istream wcout;