https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111632
Bug ID: 111632
Summary: gcc's C++ components fail to compile against recent
libc++ headers
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: dimitry at andric dot com
Target Milestone: ---
As reported in https://bugs.freebsd.org/274041 and a number of related PRs,
when building gcc's C++ sources against recent libc++ (>= 17), 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.
