[MacPorts] #70341: g++ fails to compile when -libstd=libc++ is set

[MacPorts]

#70341: g++ fails to compile when -libstd=libc++ is set
--------------------------------+--------------------
  Reporter:  mouse07410         |      Owner:  (none)
      Type:  defect             |     Status:  new
  Priority:  Normal             |  Milestone:
 Component:  ports              |    Version:
Resolution:                     |   Keywords:
      Port:  gcc12 gcc13 gcc14  |
--------------------------------+--------------------

Comment (by mouse07410):

 >  libc++ support with GCC is, and always has been, somewhat experimental.
 Its a nice idea, and when I first added support it worked OK, for some
 cases, but even then you could not compile every you could with
 GCC+stdlibc++ or clang+libc++, there where plenty of things which just did
 not work

 I see. I was not aware of that. In fact, for a long time, I used G++ to
 compile Crypto++ package with {{{-stdlib=libc++}}}, and it worked fine
 (!!!).

 Starting with GCC12, it stopped working. :-(

 Yes, I confirm that "quick_exit" is the issue that keeps rearing its ugly
 head now.


 > by all means play with this. Try out different clang versions to use as
 the header source

 Here's what I get ({{{gcc13-libcxx +clang18}}} and {{{gcc12-libcxx
 +clang17}}}):

 {{{
 $ g++-mp-13 -stdlib=libc++ -o t3 t3.cpp
 In file included from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/new:364,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/__memory/construct_at.h:23,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/__memory/allocator_traits.h:14,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/__memory/allocation_guard.h:15,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/__memory/shared_ptr.h:24,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/__locale:15,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/ios:223,
                  from
 /opt/local/libexec/gcc13/libc++/include/c++/v1/iostream:43,
                  from t3.cpp:1:
 /opt/local/libexec/gcc13/libc++/include/c++/v1/cstdlib:146:9: error:
 'at_quick_exit' has not been declared in '::'
   146 | using ::at_quick_exit _LIBCPP_USING_IF_EXISTS;
       |         ^~~~~~~~~~~~~
 /opt/local/libexec/gcc13/libc++/include/c++/v1/cstdlib:147:9: error:
 'quick_exit' has not been declared in '::'
   147 | using ::quick_exit _LIBCPP_USING_IF_EXISTS;
       |         ^~~~~~~~~~
 $ g++-mp-12 -stdlib=libc++ -o t3 t3.cpp
 In file included from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/new:99,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/__memory/construct_at.h:23,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/__memory/allocator_traits.h:14,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/__memory/allocation_guard.h:15,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/__memory/shared_ptr.h:22,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/__locale:15,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/ios:222,
                  from
 /opt/local/libexec/gcc12/libc++/include/c++/v1/iostream:43,
                  from t3.cpp:1:
 /opt/local/libexec/gcc12/libc++/include/c++/v1/cstdlib:144:9: error:
 'at_quick_exit' has not been declared in '::'
   144 | using ::at_quick_exit _LIBCPP_USING_IF_EXISTS;
       |         ^~~~~~~~~~~~~
 /opt/local/libexec/gcc12/libc++/include/c++/v1/cstdlib:145:9: error:
 'quick_exit' has not been declared in '::'
   145 | using ::quick_exit _LIBCPP_USING_IF_EXISTS;
       |         ^~~~~~~~~~
 $
 }}}

 Same problem you're observing. Any luck approaching it, BTW?

-- 
Ticket URL: <https://trac.macports.org/ticket/70341#comment:4>
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