https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86215
--- Comment #5 from simon at pushface dot org ---
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/opt/gcc-9.1.0/bin/../libexec/gcc/x86_64-apple-darwin15/9.1.0/lto-wrapper
Target: x86_64-apple-darwin15
Configured with: /Volumes/Miscellaneous/tmp/gcc-9.1.0/configure
--prefix=/Volumes/Miscellaneous/tmp/opt/gcc-9.1.0 --without-libiconv-prefix
--disable-libmudflap --disable-libstdcxx-pch --disable-libsanitizer
--disable-libcc1 --disable-libcilkrts --disable-multilib --disable-nls
--enable-languages=c,c++,ada,fortran,objc,obj-c++ --host=x86_64-apple-darwin15
--target=x86_64-apple-darwin15 --build=x86_64-apple-darwin15
--with-boot-ldflags='-static-libstdc++ -static-libgcc
-Wl,-headerpad_max_install_names'
Thread model: posix
gcc version 9.1.0 (GCC)
$ g++ demo.cc -static-libgcc -static-libstdc++
ld: warning: direct access in function 'operator new[](unsigned long,
std::nothrow_t const&) [clone .cold]' from file
'/opt/gcc-9.1.0/bin/../lib/gcc/x86_64-apple-darwin15/9.1.0/../../../libstdc++.a(new_opvnt.o)'
to global weak symbol 'operator new[](unsigned long, std::nothrow_t const&)'
from file
'/opt/gcc-9.1.0/bin/../lib/gcc/x86_64-apple-darwin15/9.1.0/../../../libstdc++.a(new_opvnt.o)'
means the weak symbol cannot be overridden at runtime. This was likely caused
by different translation units being compiled with different visibility
settings.ld: warning: direct access in function 'operator new[](unsigned long,
std::nothrow_t const&) [clone .cold]' from file
'/opt/gcc-9.1.0/bin/../lib/gcc/x86_64-apple-darwin15/9.1.0/../../../libstdc++.a(new_opvnt.o)'
to global weak symbol 'operator new[](unsigned long, std::nothrow_t const&)'
from file
'/opt/gcc-9.1.0/bin/../lib/gcc/x86_64-apple-darwin15/9.1.0/../../../libstdc++.a(new_opvnt.o)'
means the weak symbol cannot be overridden at runtime. This was likely caused
by different translation units being compiled with different visibility
settings.
$ otool -L a.out
a.out:
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current
version 1252.250.1)
$ DYLD_PRINT_LIBRARIES=1 ./a.out
dyld: loaded: /Users/simon/tmp/bugs/86215/./a.out
dyld: loaded: /usr/lib/libSystem.B.dylib
dyld: loaded: /usr/lib/system/libcache.dylib
dyld: loaded: /usr/lib/system/libcommonCrypto.dylib
dyld: loaded: /usr/lib/system/libcompiler_rt.dylib
dyld: loaded: /usr/lib/system/libcopyfile.dylib
dyld: loaded: /usr/lib/system/libcorecrypto.dylib
dyld: loaded: /usr/lib/system/libdispatch.dylib
dyld: loaded: /usr/lib/system/libdyld.dylib
dyld: loaded: /usr/lib/system/libkeymgr.dylib
dyld: loaded: /usr/lib/system/liblaunch.dylib
dyld: loaded: /usr/lib/system/libmacho.dylib
dyld: loaded: /usr/lib/system/libquarantine.dylib
dyld: loaded: /usr/lib/system/libremovefile.dylib
dyld: loaded: /usr/lib/system/libsystem_asl.dylib
dyld: loaded: /usr/lib/system/libsystem_blocks.dylib
dyld: loaded: /usr/lib/system/libsystem_c.dylib
dyld: loaded: /usr/lib/system/libsystem_configuration.dylib
dyld: loaded: /usr/lib/system/libsystem_coreservices.dylib
dyld: loaded: /usr/lib/system/libsystem_darwin.dylib
dyld: loaded: /usr/lib/system/libsystem_dnssd.dylib
dyld: loaded: /usr/lib/system/libsystem_info.dylib
dyld: loaded: /usr/lib/system/libsystem_m.dylib
dyld: loaded: /usr/lib/system/libsystem_malloc.dylib
dyld: loaded: /usr/lib/system/libsystem_networkextension.dylib
dyld: loaded: /usr/lib/system/libsystem_notify.dylib
dyld: loaded: /usr/lib/system/libsystem_sandbox.dylib
dyld: loaded: /usr/lib/system/libsystem_secinit.dylib
dyld: loaded: /usr/lib/system/libsystem_kernel.dylib
dyld: loaded: /usr/lib/system/libsystem_platform.dylib
dyld: loaded: /usr/lib/system/libsystem_pthread.dylib
dyld: loaded: /usr/lib/system/libsystem_symptoms.dylib
dyld: loaded: /usr/lib/system/libsystem_trace.dylib
dyld: loaded: /usr/lib/system/libunwind.dylib
dyld: loaded: /usr/lib/system/libxpc.dylib
dyld: loaded: /usr/lib/libobjc.A.dylib
dyld: loaded: /usr/lib/libc++abi.dylib
dyld: loaded: /usr/lib/libc++.1.dylib
abc123
NB, this GCC was built for darwin15, run on darwin18.
