Adjust msvc_stdlib_force_include.hpp to handle clang++

[EricWF]

Summary

This patch adjusts the newly added msvc_stdlib_force_include.hpp so that it also works when used with clang++.

[EricWF]

Upload correct diff.

[STL_MSFT]

test/support/msvc_stdlib_force_include.hpp

14

Is this comment accurate anymore - i.e. are you using it for Clang with MSVC's STL with libc++'s tests? (Note: we'll probably be interested in doing that in the future too, with Clang/C2 - I just haven't done so because it would double our testing time.)

If so, should it be reworded to drop "compiler and"?

24

Silly question, does stdlib.h define _LIBCPP_VERSION for you? I thought you didn't control your CRT.

56

Stylistically, I usually recommend !defined(clang) here, since that's what you tested.

64

We need TEST_STD_VER from somewhere - I preferred to define it here instead of in our test harness. (The idea was that this header would be our central source of macros.) Do you really need to remove it from this file? If so, I can live with that, I just want to make sure.

Note that MSVC's STL has a mostly-C++14 mode (all of C++14 plus the parts of C++17 we had implemented as of 2015 Update 2) and a partially-C++17 mode (enabled by /std:c++latest). While we test both modes in our internal tests, with libc++'s tests I've just used the C++17 mode so far (it is generally a superset, except for the removed features, and we have to enable those anyways for you).

I suppose there's another way to do this. After including any MSVC STL header, _HAS_CXX17 is defined to either 0 or 1, telling you what mode we're in. Good old <ciso646> provides this.

[EricWF]

test/support/msvc_stdlib_force_include.hpp

24

Yes stdlib.h and most other C headers define _LIBCPP_VERSION. We con't control our CRT but we do wrap the headers in our own versions that adjust according to the C++ library spec as needed. (PS. This is why libc++ needs #include_next)

64

I don't have to remove it, no. but shouldn't test_macros.h default TEST_STD_VER to 16 by default, or does MSVC still emit __cplusplus == 201403L? I know when targeting your STL with clang++ -std=c++1z this was unneeded, I assumed the same for MSVC.

[EricWF]

• Fix incorrect comment at top of file.
• Fix non-matching #endif comment.

[STL_MSFT]

test/support/msvc_stdlib_force_include.hpp

64

C1XX says __cplusplus == 199711 (even VS 2017 with /std:c++latest). Basically, we can't rev that number until we've implemented everything in C++11 (including two-phase, C99 preprocessor, and Expression SFINAE), or the Internet would riot ("how DARE you claim conformance you don't have", torches and pitchforks, etc.).

C1XX indicates /std:c++14 versus /std:c++latest with _MSVC_LANG (which is basically what __cplusplus would be), while the STL indicates its level of support with _HAS_CXX17 (because we support compiler-latest with STL-14).

How about this for a fix: (1) have this header stop defining TEST_STD_VER, (2) teach test_macros.h to see whether _HAS_CXX17 is defined before inspecting __cplusplus (and test_macros.h already includes <ciso646>), and (3) if _HAS_CXX17 is defined to 1, define TEST_STD_VER to 17 (it's the current year!), (4) if _HAS_CXX17 is defined to 0, define TEST_STD_VER to 14 (close enough, our extra Update 2 features shouldn't interfere).

[EricWF]

Re-add #define TEST_STD_VER 17

include/__config

 # define _LIBCPP_HAS_QUICK_EXIT
 #endif  // __NetBSD__
 
 #if defined(_WIN32)
 #  define _LIBCPP_WIN32API      1
 #  define _LIBCPP_LITTLE_ENDIAN 1
 #  define _LIBCPP_BIG_ENDIAN    0
 #  define _LIBCPP_SHORT_WCHAR   1
-
 // If mingw not explicitly detected, assume using MS C runtime only.
 #  ifndef __MINGW32__
 #    define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
 #  endif
 #  if (defined(_M_AMD64) || defined(__x86_64__)) || (defined(_M_ARM) || defined(__arm__))
 #    define _LIBCPP_HAS_BITSCAN64
 #  endif
+# if defined(_LIBCPP_MSVCRT)
+#   define _LIBCPP_HAS_QUICK_EXIT
+# endif
 #endif // defined(_WIN32)
 
 #ifdef __sun__
 # include <sys/isa_defs.h>
 # ifdef _LITTLE_ENDIAN
 #   define _LIBCPP_LITTLE_ENDIAN 1
 #   define _LIBCPP_BIG_ENDIAN    0
 # else

test/libcxx/test/config.py

class Configuration(object):
 
     def configure_compile_flags_header_includes(self):
         support_path = os.path.join(self.libcxx_src_root, 'test', 'support')
         if self.cxx_stdlib_under_test != 'libstdc++' and \
            not self.is_windows:
             self.cxx.compile_flags += [
                 '-include', os.path.join(support_path, 'nasty_macros.hpp')]
         if self.cxx_stdlib_under_test == 'msvc':
-            # FIXME: Uncomment this once STL commits the support header.
-            # self.cxx.compile_flags += [
-            #    '-include', os.path.join(support_path,
-            #                             'msvc_stdlib_force_include.h')]
+            self.cxx.compile_flags += [
+                '-include', os.path.join(support_path,
+                                         'msvc_stdlib_force_include.hpp')]
             pass
         if self.is_windows and self.debug_build and \
                 self.cxx_stdlib_under_test != 'msvc':
             self.cxx.compile_flags += [
                 '-include', os.path.join(support_path,
                                          'set_windows_crt_report_mode.h')
             ]
         self.configure_config_site_header()

test/support/msvc_stdlib_force_include.hpp

 //===----------------------------------------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_HPP
 #define SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_HPP
 
-
-// This header is force-included when running MSVC's compiler and standard library with libc++'s tests.
-
+// This header is force-included when running the libc++ tests against the
+// MSVC standard library.
 
 // Avoid assertion dialogs.
 #define _CRT_SECURE_INVALID_PARAMETER(EXPR) ::abort()
 
 #include <crtdbg.h>
 #include <stdlib.h>
 
+#if defined(_LIBCPP_VERSION)
+#error This header may not be used when targeting libc++
+#endif
+
 struct AssertionDialogAvoider {
     AssertionDialogAvoider() {
         _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE);
         _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
 
         _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE);
         _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
     }
 };
 
 const AssertionDialogAvoider assertion_dialog_avoider{};
 
 
+// MSVC frontend only configurations
+#if !defined(__clang__)
 // Simulate feature-test macros.
 #define __has_feature(X) _MSVC_HAS_FEATURE_ ## X
 #define _MSVC_HAS_FEATURE_cxx_exceptions    1
 #define _MSVC_HAS_FEATURE_cxx_rtti          1
 #define _MSVC_HAS_FEATURE_address_sanitizer 0
 #define _MSVC_HAS_FEATURE_memory_sanitizer  0
 #define _MSVC_HAS_FEATURE_thread_sanitizer  0
 
+// Silence compiler warnings.
+#pragma warning(disable: 4180) // qualifier applied to function type has no meaning; ignored
+#pragma warning(disable: 4521) // multiple copy constructors specified
+#pragma warning(disable: 4702) // unreachable code
+#pragma warning(disable: 6294) // Ill-defined for-loop:  initial condition does not satisfy test.  Loop body not executed.
+#pragma warning(disable: 28251) // Inconsistent annotation for 'new': this instance has no annotations.
 
-// atomic_is_lock_free.pass.cpp needs this VS 2015 Update 2 fix.
-#define _ENABLE_ATOMIC_ALIGNMENT_FIX
-
-
-// Enable features that /std:c++latest removes by default.
-#define _HAS_AUTO_PTR_ETC          1
-#define _HAS_FUNCTION_ASSIGN       1
-#define _HAS_OLD_IOSTREAMS_MEMBERS 1
-
+#endif // !defined(__clang__)
 
 // MSVC doesn't have __int128_t.
 #define _LIBCPP_HAS_NO_INT128
 
-
 // MSVC has quick_exit() and at_quick_exit().
 #define _LIBCPP_HAS_QUICK_EXIT
 
+// atomic_is_lock_free.pass.cpp needs this VS 2015 Update 2 fix.
+#define _ENABLE_ATOMIC_ALIGNMENT_FIX
 
-// MSVC's STL partially supports C++17.
-#define TEST_STD_VER 17
-
+// Enable features that /std:c++latest removes by default.
+#define _HAS_AUTO_PTR_ETC          1
+#define _HAS_FUNCTION_ASSIGN       1
+#define _HAS_OLD_IOSTREAMS_MEMBERS 1
 
 // Silence warnings about raw pointers and other unchecked iterators.
 #define _SCL_SECURE_NO_WARNINGS
 
-
-// Silence compiler warnings.
-#pragma warning(disable: 4180) // qualifier applied to function type has no meaning; ignored
-#pragma warning(disable: 4521) // multiple copy constructors specified
-#pragma warning(disable: 4702) // unreachable code
-#pragma warning(disable: 6294) // Ill-defined for-loop:  initial condition does not satisfy test.  Loop body not executed.
-#pragma warning(disable: 28251) // Inconsistent annotation for 'new': this instance has no annotations.
-
-
 #endif // SUPPORT_MSVC_STDLIB_FORCE_INCLUDE_HPP