[libcxx-commits] [libcxx] Fix wchar.h to work with modules. (PR #146630)

[via libcxx-commits]

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@@ -0,0 +1,105 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// Lack of header guards is intentional.
+// This file should only ever be included by wchar.h, which provides its own
+// header guard. This prevents macro hiding issues with modules where cwchar
+// complains that _LIBCPP_WCHAR_H isn't present.
+
+#include <__config>
+#include <__mbstate_t.h> // provide mbstate_t
+#include <stddef.h>      // provide size_t
+
+// include_next doesn't work with modules.
+#if __has_include_next(<wchar.h>)
+#  define _LIBCPP_INCLUDE_NEXT_WCHAR
+#  include_next <wchar.h>
+#  undef _LIBCPP_INCLUDE_NEXT_WCHAR
+#endif
+
+// Determine whether we have const-correct overloads for wcschr and friends.
+#if defined(_WCHAR_H_CPLUSPLUS_98_CONFORMANCE_)
+#  define _LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS 1
+#elif defined(__GLIBC_PREREQ)
+#  if __GLIBC_PREREQ(2, 10)
+#    define _LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS 1
+#  endif
+#elif defined(_LIBCPP_MSVCRT)
+#  if defined(_CRT_CONST_CORRECT_OVERLOADS)
+#    define _LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS 1
+#  endif
+#endif
+
+#if _LIBCPP_HAS_WIDE_CHARACTERS
+#  if defined(__cplusplus) && !defined(_LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS) && defined(_LIBCPP_PREFERRED_OVERLOAD)
+extern "C++" {
+inline _LIBCPP_HIDE_FROM_ABI wchar_t* __libcpp_wcschr(const wchar_t* __s, wchar_t __c) {
+  return (wchar_t*)wcschr(__s, __c);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD const wchar_t* wcschr(const wchar_t* __s, wchar_t __c) {
+  return __libcpp_wcschr(__s, __c);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD wchar_t* wcschr(wchar_t* __s, wchar_t __c) {
+  return __libcpp_wcschr(__s, __c);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI wchar_t* __libcpp_wcspbrk(const wchar_t* __s1, const wchar_t* __s2) {
+  return (wchar_t*)wcspbrk(__s1, __s2);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD const wchar_t*
+wcspbrk(const wchar_t* __s1, const wchar_t* __s2) {
+  return __libcpp_wcspbrk(__s1, __s2);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD wchar_t* wcspbrk(wchar_t* __s1, const wchar_t* __s2) {
+  return __libcpp_wcspbrk(__s1, __s2);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI wchar_t* __libcpp_wcsrchr(const wchar_t* __s, wchar_t __c) {
+  return (wchar_t*)wcsrchr(__s, __c);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD const wchar_t* wcsrchr(const wchar_t* __s, wchar_t __c) {
+  return __libcpp_wcsrchr(__s, __c);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD wchar_t* wcsrchr(wchar_t* __s, wchar_t __c) {
+  return __libcpp_wcsrchr(__s, __c);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI wchar_t* __libcpp_wcsstr(const wchar_t* __s1, const wchar_t* __s2) {
+  return (wchar_t*)wcsstr(__s1, __s2);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD const wchar_t*
+wcsstr(const wchar_t* __s1, const wchar_t* __s2) {
+  return __libcpp_wcsstr(__s1, __s2);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD wchar_t* wcsstr(wchar_t* __s1, const wchar_t* __s2) {
+  return __libcpp_wcsstr(__s1, __s2);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI wchar_t* __libcpp_wmemchr(const wchar_t* __s, wchar_t __c, size_t __n) {
+  return (wchar_t*)wmemchr(__s, __c, __n);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD const wchar_t*
+wmemchr(const wchar_t* __s, wchar_t __c, size_t __n) {
+  return __libcpp_wmemchr(__s, __c, __n);
+}
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD wchar_t* wmemchr(wchar_t* __s, wchar_t __c, size_t __n) {
+  return __libcpp_wmemchr(__s, __c, __n);
+}
+}
+#  endif
+
+#  if defined(__cplusplus) && (defined(_LIBCPP_MSVCRT_LIKE) || defined(__MVS__))
+extern "C" {
+size_t mbsnrtowcs(
----------------
matts1 wrote:

These ones don't strictly *need* to be here, but unless something relies on macros that can be set by the includer, it should prefer to be non-textual (this relies on macros set in __config).

So if we're going to the effort of moving the definitions, we might as well move this.

https://github.com/llvm/llvm-project/pull/146630