Re: [PATCH] Include safe-ctype.h after C++ standard headers, to avoid over-poisoning

[FX Coudert <fxcoudert@gmail.com>]

I would like to patch this patch from September 2023:
https://gcc.gnu.org/pipermail/gcc-patches/2023-September/631611.html

This bug is now hitting macOS in the latest version of Xcode (it was originally seen on freebsd).
I confirm that the patch is restoring bootstrap on x86_64-apple-darwin23

OK to push?
FX





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