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

[Iain Sandoe <iain@sandoe.co.uk>]

> On 6 Mar 2024, at 13:54, Sam James <sam@gentoo.org> wrote:
> 
> FX Coudert <fxcoudert@gmail.com> writes:
> 
>> 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
> 
> Iain hit an issue with it and I never got a chance to look into how to
> fix it.

Hmm I recall trying it and finding a problem - was there some different fix applied
in the end?

Iain

> 
>> 
>> 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.
>>>