[Bug middle-end/111632] gcc fails to bootstrap when using libc++

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111632

--- Comment #24 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Iain D Sandoe
<iains@gcc.gnu.org>:

https://gcc.gnu.org/g:68057560ff1fc0fb2df38c2f9627a20c9a8da5c5

commit r13-8571-g68057560ff1fc0fb2df38c2f9627a20c9a8da5c5
Author: Francois-Xavier Coudert <fxcoudert@gcc.gnu.org>
Date:   Thu Mar 7 14:36:03 2024 +0100

    Include safe-ctype.h after C++ standard headers, to avoid over-poisoning

    When building gcc's C++ sources against recent libc++, the poisoning of
    the ctype macros due to including safe-ctype.h before including C++
    standard headers such as <list>, <map>, etc, causes many compilation
    errors, similar to:

      In file included from /home/dim/src/gcc/master/gcc/gensupport.cc:23:
      In file included from /home/dim/src/gcc/master/gcc/system.h:233:
      In file included from /usr/include/c++/v1/vector:321:
      In file included from
      /usr/include/c++/v1/__format/formatter_bool.h:20:
      In file included from
      /usr/include/c++/v1/__format/formatter_integral.h:32:
      In file included from /usr/include/c++/v1/locale:202:
      /usr/include/c++/v1/__locale:546:5: error: '__abi_tag__' attribute
      only applies to structs, variables, functions, and namespaces
        546 |     _LIBCPP_INLINE_VISIBILITY
            |     ^
      /usr/include/c++/v1/__config:813:37: note: expanded from macro
      '_LIBCPP_INLINE_VISIBILITY'
        813 | #  define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI
            |                                     ^
      /usr/include/c++/v1/__config:792:26: note: expanded from macro
      '_LIBCPP_HIDE_FROM_ABI'
        792 |
        __attribute__((__abi_tag__(_LIBCPP_TOSTRING(
      _LIBCPP_VERSIONED_IDENTIFIER))))
            |                          ^
      In file included from /home/dim/src/gcc/master/gcc/gensupport.cc:23:
      In file included from /home/dim/src/gcc/master/gcc/system.h:233:
      In file included from /usr/include/c++/v1/vector:321:
      In file included from
      /usr/include/c++/v1/__format/formatter_bool.h:20:
      In file included from
      /usr/include/c++/v1/__format/formatter_integral.h:32:
      In file included from /usr/include/c++/v1/locale:202:
      /usr/include/c++/v1/__locale:547:37: error: expected ';' at end of
      declaration list
        547 |     char_type toupper(char_type __c) const
            |                                     ^
      /usr/include/c++/v1/__locale:553:48: error: too many arguments
      provided to function-like macro invocation
        553 |     const char_type* toupper(char_type* __low, const
        char_type* __high) const
            |                                                ^
      /home/dim/src/gcc/master/gcc/../include/safe-ctype.h:146:9: note:
      macro 'toupper' defined here
        146 | #define toupper(c) do_not_use_toupper_with_safe_ctype
            |         ^

    This is because libc++ uses different transitive includes than
    libstdc++, and some of those transitive includes pull in various ctype
    declarations (typically via <locale>).

    There was already a special case for including <string> before
    safe-ctype.h, so move the rest of the C++ standard header includes to
    the same location, to fix the problem.

            PR middle-end/111632

    gcc/ChangeLog:

            * system.h: Include safe-ctype.h after C++ standard headers.

    Signed-off-by: Dimitry Andric <dimitry@andric.com>
    (cherry picked from commit 9970b576b7e4ae337af1268395ff221348c4b34a)