[libc++] Refactor Windows support headers.

Summary:
This patch refactors and tries to remove as much of the Windows support headers as possible. This is needed because they currently introduce super weird include cycles and dependencies between STL and libc headers.

The changes in this patch are:

* remove `support/win32/support.h` completely. The required parts have either been moved into `support/win32/msvc_support.h` (for `MSVC` only helpers not needed by Clang), or directly into their respective `foo.h` headers.

* Combine `locale_win32.h` and `locale_mgmt_win32.h` into a single headers, this header should only be included within `__locale` or `locale` to avoid include cycles.

* Remove the unneeded parts of `limits_win32.h` and re-name it to `limits_msvc_win32.h` since it's only needed by Clang.

I've tested this patch using Clang on Windows, but I suspect it might technically regress our non-existent support for MSVC. Is somebody able to double check?

This refactor is needed to support upcoming fixes to `<locale>` on Windows.



Reviewers: bcraig, rmaprath, compnerd, EricWF

Reviewed By: EricWF

Subscribers: majnemer, cfe-commits

Differential Revision: https://reviews.llvm.org/D32988

llvm-svn: 302727

libcxx/include/__mutex_base

@@ -15,6 +15,7 @@
 #include <chrono>
 #include <system_error>
 #include <__threading_support>
+#include <__undef_min_max>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header

libcxx/include/__threading_support

@@ -30,6 +30,7 @@
 #include <Windows.h>
 #include <process.h>
 #include <fibersapi.h>
+#include <__undef_min_max>
 #endif
 
 #if defined(_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL) || \

libcxx/include/algorithm

@@ -644,8 +644,8 @@ template <class BidirectionalIterator, class Compare>
 #if defined(__IBMCPP__)
 #include "support/ibm/support.h"
 #endif
-#if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
-#include "support/win32/support.h"
+#if defined(_LIBCPP_COMPILER_MSVC)
+#include "support/win32/msvc_builtin_support.h"
 #endif
 
 #include <__undef_min_max>

libcxx/include/ctype.h

@@ -40,15 +40,6 @@ int toupper(int c);
 
 #ifdef __cplusplus
 
-#if defined(_LIBCPP_MSVCRT)
-// We support including .h headers inside 'extern "C"' contexts, so switch
-// back to C++ linkage before including these C++ headers.
-extern "C++" {
-  #include "support/win32/support.h"
-  #include "support/win32/locale_win32.h"
-}
-#endif // _LIBCPP_MSVCRT
-
 #undef isalnum
 #undef isalpha
 #undef isblank

libcxx/include/limits

@@ -111,8 +111,8 @@ template<> class numeric_limits<cv long double>;
 
 #include <__undef_min_max>
 
-#if defined(_LIBCPP_MSVCRT)
-#include "support/win32/limits_win32.h"
+#if defined(_LIBCPP_COMPILER_MSVC)
+#include "support/win32/limits_msvc_win32.h"
 #endif // _LIBCPP_MSVCRT
 
 #if defined(__IBMCPP__)

libcxx/include/stdio.h

@@ -111,8 +111,9 @@ void perror(const char* s);
 
 // snprintf
 #if defined(_LIBCPP_MSVCRT)
-extern "C++" {
-#include "support/win32/support.h"
+extern "C" {
+int vasprintf(char **sptr, const char *__restrict fmt, va_list ap);
+int asprintf(char **sptr, const char *__restrict fmt, ...);
 }
 #endif
 

libcxx/include/stdlib.h

@@ -97,10 +97,6 @@ void *aligned_alloc(size_t alignment, size_t size);                       // C11
 
 extern "C++" {
 
-#ifdef _LIBCPP_MSVCRT
-#include "support/win32/locale_win32.h"
-#endif // _LIBCPP_MSVCRT
-
 #undef abs
 #undef div
 #undef labs

libcxx/include/support/win32/limits_msvc_win32.h

@@ -1,5 +1,5 @@
 // -*- C++ -*-
-//===--------------------- support/win32/limits_win32.h -------------------===//
+//===------------------ support/win32/limits_msvc_win32.h -----------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -8,17 +8,21 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP_SUPPORT_WIN32_LIMITS_WIN32_H
-#define _LIBCPP_SUPPORT_WIN32_LIMITS_WIN32_H
+#ifndef _LIBCPP_SUPPORT_WIN32_LIMITS_MSVC_WIN32_H
+#define _LIBCPP_SUPPORT_WIN32_LIMITS_MSVC_WIN32_H
 
 #if !defined(_LIBCPP_MSVCRT)
 #error "This header complements the Microsoft C Runtime library, and should not be included otherwise."
-#else
+#endif
+#if defined(__clang__)
+#error "This header should only be included when using Microsofts C1XX frontend"
+#endif
 
 #include <limits.h> // CHAR_BIT
 #include <float.h> // limit constants
+#include <math.h> // HUGE_VAL
+#include <ymath.h> // internal MSVC header providing the needed functionality
 
-#if ! defined(__clang__)
 #define __CHAR_BIT__       CHAR_BIT
 
 #define __FLT_MANT_DIG__   FLT_MANT_DIG
@@ -61,19 +65,8 @@
 #define __LDBL_DENORM_MIN__ 3.64519953188247460253e-4951L
 
 // __builtin replacements/workarounds
-#include <math.h> // HUGE_VAL
-#include <ymath.h> // internal MSVC header providing the needed functionality
-#define __builtin_huge_val()     HUGE_VAL
-#define __builtin_huge_valf()    _FInf._Float
 #define __builtin_huge_vall()    _LInf._Long_double
-#define __builtin_nan(__dummy)   _Nan._Double
-#define __builtin_nanf(__dummy)  _FNan._Float
 #define __builtin_nanl(__dummmy) _LNan._Long_double
-#define __builtin_nans(__dummy)  _Snan._Double
-#define __builtin_nansf(__dummy) _FSnan._Float
 #define __builtin_nansl(__dummy) _LSnan._Long_double
-#endif // ! defined(__clang__)
 
-#endif // _LIBCPP_MSVCRT
-
-#endif // _LIBCPP_SUPPORT_WIN32_LIMITS_WIN32_H
+#endif // _LIBCPP_SUPPORT_WIN32_LIMITS_MSVC_WIN32_H

libcxx/include/support/win32/locale_mgmt_win32.h

@@ -1,33 +0,0 @@
-// -*- C++ -*-
-//===----------------- support/win32/locale_mgmt_win32.h ------------------===//
-//
-//                     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 _LIBCPP_SUPPORT_WIN32_LOCALE_MGMT_WIN32_H
-#define _LIBCPP_SUPPORT_WIN32_LOCALE_MGMT_WIN32_H
-
-#include <xlocinfo.h> // _locale_t
-#define locale_t _locale_t
-#define LC_COLLATE_MASK _M_COLLATE
-#define LC_CTYPE_MASK _M_CTYPE
-#define LC_MONETARY_MASK _M_MONETARY
-#define LC_NUMERIC_MASK _M_NUMERIC
-#define LC_TIME_MASK _M_TIME
-#define LC_MESSAGES_MASK _M_MESSAGES
-#define LC_ALL_MASK (  LC_COLLATE_MASK \
-                     | LC_CTYPE_MASK \
-                     | LC_MESSAGES_MASK \
-                     | LC_MONETARY_MASK \
-                     | LC_NUMERIC_MASK \
-                     | LC_TIME_MASK )
-#define freelocale _free_locale
-// FIXME: base currently unused. Needs manual work to construct the new locale
-locale_t newlocale( int mask, const char * locale, locale_t base );
-locale_t uselocale( locale_t newloc );
-
-#endif // _LIBCPP_SUPPORT_WIN32_LOCALE_MGMT_WIN32_H

libcxx/include/support/win32/locale_win32.h

@@ -12,9 +12,30 @@
 #define _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
 
 #include <__config>
-#include "support/win32/support.h"
-#include "support/win32/locale_mgmt_win32.h"
 #include <stdio.h>
+#include <xlocinfo.h> // _locale_t
+
+#define LC_COLLATE_MASK _M_COLLATE
+#define LC_CTYPE_MASK _M_CTYPE
+#define LC_MONETARY_MASK _M_MONETARY
+#define LC_NUMERIC_MASK _M_NUMERIC
+#define LC_TIME_MASK _M_TIME
+#define LC_MESSAGES_MASK _M_MESSAGES
+#define LC_ALL_MASK (  LC_COLLATE_MASK \
+                     | LC_CTYPE_MASK \
+                     | LC_MESSAGES_MASK \
+                     | LC_MONETARY_MASK \
+                     | LC_NUMERIC_MASK \
+                     | LC_TIME_MASK )
+
+#define locale_t _locale_t
+
+// Locale management functions
+#define freelocale _free_locale
+// FIXME: base currently unused. Needs manual work to construct the new locale
+locale_t newlocale( int mask, const char * locale, locale_t base );
+locale_t uselocale( locale_t newloc );
+
 
 lconv *localeconv_l( locale_t loc );
 size_t mbrlen_l( const char *__restrict s, size_t n,
@@ -88,7 +109,6 @@ _LIBCPP_FUNC_VIS int snprintf_l(char *ret, size_t n, locale_t loc, const char *f
 _LIBCPP_FUNC_VIS int asprintf_l( char **ret, locale_t loc, const char *format, ... );
 _LIBCPP_FUNC_VIS int vasprintf_l( char **ret, locale_t loc, const char *format, va_list ap );
 
-
 // not-so-pressing FIXME: use locale to determine blank characters
 inline int isblank_l( int c, locale_t /*loc*/ )
 {
@@ -99,10 +119,4 @@ inline int iswblank_l( wint_t c, locale_t /*loc*/ )
     return ( c == L' ' || c == L'\t' );
 }
 
-#if defined(_LIBCPP_MSVCRT)
-inline int isblank( int c, locale_t /*loc*/ )
-{ return ( c == ' ' || c == '\t' ); }
-inline int iswblank( wint_t c, locale_t /*loc*/ )
-{ return ( c == L' ' || c == L'\t' ); }
-#endif // _LIBCPP_MSVCRT
 #endif // _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H

libcxx/include/support/win32/msvc_builtin_support.h

@@ -8,40 +8,20 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP_SUPPORT_WIN32_SUPPORT_H
-#define _LIBCPP_SUPPORT_WIN32_SUPPORT_H
+#ifndef _LIBCPP_SUPPORT_WIN32_MSVC_BUILTIN_SUPPORT_H
+#define _LIBCPP_SUPPORT_WIN32_MSVC_BUILTIN_SUPPORT_H
 
-// Functions and constants used in libc++ that
-// are missing from the Windows C library.
-
-#include <wchar.h> // mbstate_t
-#include <cstdarg> // va_ macros
-// "builtins" not implemented here for Clang or GCC as they provide
-// implementations. Assuming required for elsewhere else, certainly MSVC.
-#if defined(_LIBCPP_COMPILER_MSVC)
-#include <intrin.h>
+#ifndef _LIBCPP_COMPILER_MSVC
+#error "This header can only be included when using Microsoft's C1XX frontend"
 #endif
-#define swprintf _snwprintf
-#define vswprintf _vsnwprintf
 
 #ifndef NOMINMAX
 #define NOMINMAX
 #endif
 
-// The mingw headers already define these as static.
-#ifndef __MINGW32__
-extern "C" {
-
-int vasprintf(char **sptr, const char *__restrict fmt, va_list ap);
-int asprintf(char **sptr, const char *__restrict fmt, ...);
-size_t mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
-                  size_t nmc, size_t len, mbstate_t *__restrict ps);
-size_t wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
-                  size_t nwc, size_t len, mbstate_t *__restrict ps);
-}
-#endif // __MINGW32__
-
-#if defined(_LIBCPP_COMPILER_MSVC)
+// "builtins" not implemented here for Clang or GCC as they provide
+// implementations. Assuming required for elsewhere else, certainly MSVC.
+#include <intrin.h>
 
 // Bit builtin's make these assumptions when calling _BitScanForward/Reverse
 // etc. These assumptions are expected to be true for Win32/Win64 which this
@@ -172,6 +152,5 @@ _LIBCPP_ALWAYS_INLINE int __builtin_clz(unsigned int x)
 {
   return __builtin_clzl(x);
 }
-#endif // _LIBCPP_MSVC
 
-#endif // _LIBCPP_SUPPORT_WIN32_SUPPORT_H
+#endif // _LIBCPP_SUPPORT_WIN32_MSVC_BUILTIN_SUPPORT_H

libcxx/include/wchar.h

@@ -166,9 +166,12 @@ inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
 }
 #endif
 
-#if defined(__cplusplus) && (defined(_LIBCPP_MSVCRT) || defined(__MINGW32__))
-extern "C++" {
-#include <support/win32/support.h> // pull in *swprintf defines
+#if defined(__cplusplus) && defined(_LIBCPP_MSVCRT)
+extern "C" {
+size_t mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+                  size_t nmc, size_t len, mbstate_t *__restrict ps);
+size_t wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
+                  size_t nwc, size_t len, mbstate_t *__restrict ps);
 }  // extern "C++"
 #endif  // __cplusplus && _LIBCPP_MSVCRT
 

libcxx/src/string.cpp

@@ -13,9 +13,6 @@
 #include "cerrno"
 #include "limits"
 #include "stdexcept"
-#ifdef _LIBCPP_MSVCRT
-#include "support/win32/support.h"
-#endif // _LIBCPP_MSVCRT
 #include <stdio.h>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
@@ -430,7 +427,7 @@ get_swprintf()
 #ifndef _LIBCPP_MSVCRT
     return swprintf;
 #else
-    return static_cast<int (__cdecl*)(wchar_t* __restrict, size_t, const wchar_t*__restrict, ...)>(swprintf);
+    return static_cast<int (__cdecl*)(wchar_t* __restrict, size_t, const wchar_t*__restrict, ...)>(_snwprintf);
 #endif
 }
 

libcxx/src/support/runtime/exception_pointer_msvc.ipp

@@ -10,6 +10,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <yvals.h> // for _CRTIMP2_PURE
 
 _CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL __ExceptionPtrCreate(_Out_ void*);
 _CRTIMP2_PURE void __CLRCALL_PURE_OR_CDECL __ExceptionPtrDestroy(_Inout_ void*);