[libc++][AIX] Correct the definition of __regex_word for AIX

[xingxue]

Summary

The patch changes the definition of __regex_word to 0x8000 for AIX because the current definition 0x80 clashes with ctype_base::print (_ISPRINT is defined as 0x80 in AIX ctype.h).

[Mordante]

Thanks for the fixes! LGTM for libc++, please wait for approval of one of the AIX maintainers.

[hubert.reinterpretcast]

LGTM; thanks! Can we have a test with a static_assert that checks the bits are disjoint (check union of all flags has the right number of 1s)?

[xingxue]

Can we have a test with a static_assert that checks the bits are disjoint (check union of all flags has the right number of 1s)?

Thanks for catching this, @hubert.reinterpretcast! There is actually an static_assert that checks if regex_word overlaps other bits but it is disabled for AIX. This update enables it.

[hubert.reinterpretcast]

In D129862#3657209, @xingxue wrote:

Can we have a test with a static_assert that checks the bits are disjoint (check union of all flags has the right number of 1s)?

Thanks for catching this, @hubert.reinterpretcast! There is actually an static_assert that checks if regex_word overlaps other bits but it is disabled for AIX. This update enables it.

Thank you, Xing, for the update! Confirming LGTM.

libcxx/include/__locale

#elif defined(__sun__) || defined(_AIX)
     static const mask cntrl  = _ISCNTRL;
     static const mask upper  = _ISUPPER;
     static const mask lower  = _ISLOWER;
     static const mask alpha  = _ISALPHA;
     static const mask digit  = _ISDIGIT;
     static const mask punct  = _ISPUNCT;
     static const mask xdigit = _ISXDIGIT;
     static const mask blank  = _ISBLANK;
+# if defined(_AIX)
+    static const mask __regex_word = 0x8000;
+# else
     static const mask __regex_word = 0x80;
+# endif
 #elif defined(_NEWLIB_VERSION)
     // Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
     typedef char mask;
     static const mask space  = _S;
     static const mask print  = _P | _U | _L | _N | _B;
     static const mask cntrl  = _C;
     static const mask upper  = _U;
     static const mask lower  = _L;

 #else
 # error unknown rune table for this platform -- do you mean to define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE?
 #endif
     static const mask alnum  = alpha | digit;
     static const mask graph  = alnum | punct;
 
     _LIBCPP_INLINE_VISIBILITY ctype_base() {}
 
-// TODO: Remove the ifndef when the assert no longer fails on AIX.
-#ifndef _AIX
     static_assert((__regex_word & ~(space | print | cntrl | upper | lower | alpha | digit | punct | xdigit | blank)) == __regex_word,
                   "__regex_word can't overlap other bits");
-#endif
 };
 
 template <class _CharT> class _LIBCPP_TEMPLATE_VIS ctype;
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS ctype<wchar_t>
     : public locale::facet,

libcxx/test/std/re/re.traits/isctype.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: LIBCXX-AIX-FIXME
-
 // <regex>
 
 // template <class charT> struct regex_traits;
 
 // bool isctype(charT c, char_class_type f) const;
 
 
 #include <regex>

libcxx/test/std/re/re.traits/lookup_classname.pass.cpp

 //===----------------------------------------------------------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: LIBCXX-AIX-FIXME
-
 // <regex>
 
 // template <class charT> struct regex_traits;
 
 // template <class ForwardIterator>
 //   char_class_type
 //   lookup_classname(ForwardIterator first, ForwardIterator last,
 //                    bool icase = false) const;