[SOLVED] Slackware64-current clang-8.0.0 build failure with dolphin-emu

orbea · 05-08-2019, 04:08 PM

I was testing clang-8.0.0 in Slackware64-current by exporting CC=clang and CXX=clang++. This works as expected with most programs, but I encountered this issue with the git master for dolphin-emu.

Code:

In file included from /tmp/SBo/dolphin-emu/Source/Core/DiscIO/Blob.cpp:19:
In file included from /tmp/SBo/dolphin-emu/Source/Core/DiscIO/DirectoryBlob.h:13:
/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/variant:1559:55: error: '__get' is missing exception specification 'noexcept'
        friend constexpr decltype(auto) __detail::__variant::__get(_Vp&& __v);
                                                             ^
/tmp/SBo/dolphin-emu/Source/Core/DiscIO/DirectoryBlob.h:59:17: note: in instantiation of template class 'std::variant<std::__cxx11::basic_string<char>, const unsigned char *>' requested here
  ContentSource m_content_source;
                ^
/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/variant:263:5: note: previous declaration is here
    __get(_Variant&& __v) noexcept
    ^

Full log: https://pastebin.com/tSQ5Z0zX

As can be seen it is using gcc 9.1.0 includes.

This reference seems like it might be relevant.

https://stackoverflow.com/questions/...le-clang-6-0-0

So I appended -stdlib=libc++ to -DCMAKE_CXX_FLAGS="$SLKCFLAGS" and it got farther.

Code:

[ 80%] Linking CXX executable ../../../Binaries/dolphin-emu-nogui
/usr/bin/ld: ../Core/CMakeFiles/core.dir/NetPlayClient.cpp.o: in function `NetPlay::NetPlayClient::Connect()':
NetPlayClient.cpp:(.text+0x12cf): undefined reference to `sf::Packet::operator<<(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)'
/usr/bin/ld: NetPlayClient.cpp:(.text+0x12de): undefined reference to `sf::Packet::operator<<(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)'
/usr/bin/ld: NetPlayClient.cpp:(.text+0x12f1): undefined reference to `sf::Packet::operator<<(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)'
/usr/bin/ld: ../Core/CMakeFiles/core.dir/NetPlayClient.cpp.o: in function `NetPlay::NetPlayClient::OnData(sf::Packet&)':
NetPlayClient.cpp:(.text+0x1bc8): undefined reference to `sf::Packet::operator>>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)'
/usr/bin/ld: NetPlayClient.cpp:(.text+0x1d0c): undefined reference to `sf::Packet::operator>>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)'
/usr/bin/ld: NetPlayClient.cpp:(.text+0x1eb5): undefined reference to `sf::Packet::operator>>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)'
/usr/bin/ld: NetPlayClient.cpp:(.text+0x2255): undefined reference to `sf::Packet::operator>>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)'
/usr/bin/ld: NetPlayClient.cpp:(.text+0x2aba): undefined reference to `sf::Packet::operator>>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)'
/usr/bin/ld: ../Core/CMakeFiles/core.dir/NetPlayClient.cpp.o:NetPlayClient.cpp:(.text+0x2b4f): more undefined references to `sf::Packet::operator>>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)' follow
/usr/bin/ld: ../Core/CMakeFiles/core.dir/NetPlayClient.cpp.o: in function `NetPlay::NetPlayClient::SendChatMessage(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)':
NetPlayClient.cpp:(.text+0x7e50): undefined reference to `sf::Packet::operator<<(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)'
/usr/bin/ld: ../Core/CMakeFiles/core.dir/NetPlayClient.cpp.o: in function `void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, NetPlay::NetPlayClient::ComputeMD5(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::$_6> >(void*)':
NetPlayClient.cpp:(.text+0xa84e): undefined reference to `sf::Packet::operator<<(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)'
/usr/bin/ld: ../Core/CMakeFiles/core.dir/WiiUtils.cpp.o: in function `WiiUtils::OnlineSystemUpdater::GetSystemTitles()':
WiiUtils.cpp:(.text+0x1c73): undefined reference to `pugi::xml_document::save(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned int, pugi::xml_encoding) const'
clang-8: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [Source/Core/DolphinNoGUI/CMakeFiles/dolphin-nogui.dir/build.make:181: Binaries/dolphin-emu-nogui] Error 1
make[1]: *** [CMakeFiles/Makefile2:1470: Source/Core/DolphinNoGUI/CMakeFiles/dolphin-nogui.dir/all] Error 2
make: *** [Makefile:152: all] Error 2

Full log: https://pastebin.com/t1NebpLz

I asked dolphin developers on irc and was told they they could compile dolphin-emu with clang without doing anything special.

So am I doing something wrong, or maybe there is something missing in the llvm package?

For reference here is my build script.

https://notabug.org/orbea/SlackBuild...es/dolphin-emu

Edit: Relevant link.

https://forums.dolphin-emu.org/Threa...on-linux-fails

orbea · 05-08-2019, 07:02 PM

I found a basic c++ hello world.

Code:

#include <iostream>
using namespace std;

int main() 
{
    cout << "Hello, World!";
    return 0;
}

Code:

$ clang++ hello.cpp -o hello -v 
clang version 8.0.0 (tags/RELEASE_800/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-slackware-linux/9.1.0
Selected GCC installation: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
 "/usr/bin/clang-8" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name hello.cpp -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -v -resource-dir /usr/bin/../lib64/clang/8.0.0 -cxx-isystem /usr/lib64/qt/include -internal-isystem /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0 -internal-isystem /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/x86_64-slackware-linux -internal-isystem /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib64/clang/8.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /tmp -ferror-limit 19 -fmessage-length 82 -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/hello-603b51.o -x c++ hello.cpp -faddrsig
clang -cc1 version 8.0.0 based upon LLVM 8.0.0 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib64/qt/include
 /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0
 /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/x86_64-slackware-linux
 /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/backward
 /usr/local/include
 /usr/bin/../lib64/clang/8.0.0/include
 /usr/include
End of search list.
 "/usr/bin/ld" --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o hello /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crt1.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crti.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/crtbegin.o -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0 -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64 -L/usr/bin/../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../.. -L/usr/bin/../lib -L/lib -L/usr/lib /tmp/hello-603b51.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/crtend.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crtn.o

See how it includes gcc headers first.

Code:

#include "..." search starts here:
#include <...> search starts here:
 /usr/lib64/qt/include
 /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0
 /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/x86_64-slackware-linux
 /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../include/c++/9.1.0/backward
 /usr/local/include
 /usr/bin/../lib64/clang/8.0.0/include
 /usr/include
End of search list.

However if I build with -stdlib=libc++ it finds the llvm headers.

Code:

$ clang++ -stdlib=libc++ hello.cpp -o hello -v 
clang version 8.0.0 (tags/RELEASE_800/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-slackware-linux/9.1.0
Selected GCC installation: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
 "/usr/bin/clang-8" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name hello.cpp -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -v -resource-dir /usr/bin/../lib64/clang/8.0.0 -cxx-isystem /usr/lib64/qt/include -internal-isystem /usr/bin/../include/c++/v1 -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib64/clang/8.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /tmp -ferror-limit 19 -fmessage-length 82 -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/hello-d0685a.o -x c++ hello.cpp -faddrsig
clang -cc1 version 8.0.0 based upon LLVM 8.0.0 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib64/qt/include
 /usr/bin/../include/c++/v1
 /usr/local/include
 /usr/bin/../lib64/clang/8.0.0/include
 /usr/include
End of search list.
 "/usr/bin/ld" --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o hello /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crt1.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crti.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/crtbegin.o -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0 -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64 -L/usr/bin/../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../.. -L/usr/bin/../lib -L/lib -L/usr/lib /tmp/hello-d0685a.o -lc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/crtend.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crtn.o

Code:

#include "..." search starts here:
#include <...> search starts here:
 /usr/lib64/qt/include
 /usr/bin/../include/c++/v1
 /usr/local/include
 /usr/bin/../lib64/clang/8.0.0/include
 /usr/include
End of search list.

If I understand correctly dolphin-emu is failing without -stdlib=libc++ because of a conflict between the gcc headers and clang while when built with -stdlib=libc++ it fails later because various dependencies are not built with that compiler argument. How would someone get out of this or should I conclude that clang is not fully usable in Slackware?

orbea · 05-09-2019, 12:58 AM

Following gentoo's ebuild I tried to rebuild llvm with the following.

Code:

-DCLANG_DEFAULT_CXX_STDLIB=libc++ \
-DCLANG_DEFAULT_RTLIB=compiler-rt

https://gitweb.gentoo.org/repo/gento...g-8.0.0.ebuild

This seem to have the intended effect of finding the correct includes, but now nothing links with clang so I am obviously missing something.

Code:

$ clang++ hello.cpp -o hello -v
clang version 8.0.0 (tags/RELEASE_800/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-slackware-linux/9.1.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-slackware-linux/9.1.0
Selected GCC installation: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
 "/usr/bin/clang-8" -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name hello.cpp -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -v -resource-dir /usr/bin/../lib64/clang/8.0.0 -cxx-isystem /usr/lib64/qt/include -internal-isystem /usr/bin/../include/c++/v1 -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib64/clang/8.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /tmp -ferror-limit 19 -fmessage-length 82 -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /tmp/hello-99b552.o -x c++ hello.cpp -faddrsig
clang -cc1 version 8.0.0 based upon LLVM 8.0.0 default target x86_64-unknown-linux-gnu
ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib64/qt/include
 /usr/bin/../include/c++/v1
 /usr/local/include
 /usr/bin/../lib64/clang/8.0.0/include
 /usr/include
End of search list.
 "/usr/bin/ld" --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o hello /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crt1.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crti.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/crtbegin.o -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0 -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64 -L/usr/bin/../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../.. -L/usr/bin/../lib -L/lib -L/usr/lib /tmp/hello-99b552.o -lc++ -lm /usr/bin/../lib64/clang/8.0.0/lib/linux/libclang_rt.builtins-x86_64.a -lc /usr/bin/../lib64/clang/8.0.0/lib/linux/libclang_rt.builtins-x86_64.a /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/crtend.o /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/crtn.o
/usr/bin/ld: /tmp/hello-99b552.o: undefined reference to symbol '_Unwind_Resume@@GCC_3.0'
/usr/bin/ld: /usr/bin/../lib64/gcc/x86_64-slackware-linux/9.1.0/../../../../lib64/../lib64/libgcc_s.so.1: error adding symbols: DSO missing from command line
clang-8: error: linker command failed with exit code 1 (use -v to see invocation)

orbea · 05-09-2019, 10:19 AM

I added llvm's libunwind to the llvm.SlackBuild.

http://releases.llvm.org/8.0.0/libun...0.0.src.tar.xz

And added the following configure argument.

Code:

-DLIBCXXABI_USE_LLVM_UNWINDER=ON

Now hello.cpp compiles and links. Unfortunately dolphin-emu now fails to link instead of the first issue, so I am still missing something...

Code:

/usr/bin/ld: CMakeFiles/common.dir/FileUtil.cpp.o: undefined reference to symbol '_ZNSt14basic_ifstreamIcSt11char_traitsIcEEC1ERKNSt7__cxx1112basic_stringIcS1_SaIcEEESt13_Ios_Openmode@@GLIBCXX_3.4.21'
/usr/bin/ld: /usr/lib64/libstdc++.so.6: error adding symbols: DSO missing from command line
clang-8: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [Source/Core/Common/CMakeFiles/traversal_server.dir/build.make:95: Binaries/traversal_server] Error 1

Reference: https://stackoverflow.com/questions/...ocker-image-sh

orbea · 05-09-2019, 12:18 PM

Regarding the original error it seems variant is broken using clang++ with libstdc++, but not with libc++. Slackware uses the former and switching to libc++ doesn't seem practical given how many libraries would conflict.

There are already existing llvm issues for this.

https://bugs.llvm.org/show_bug.cgi?id=31852
https://bugs.llvm.org/show_bug.cgi?id=33222

Which reports it was fixed, I think in these two commits which should already be applied.

https://github.com/llvm-mirror/clang...e37368f2243edc
https://github.com/llvm-mirror/clang...087f43cd21fb27

However it clearly is not fixed...

orbea · 05-09-2019, 01:29 PM

I found a variant demo.

Code:

#include <variant>
#include <string>
#include <cassert>
 
int main()
{
    std::variant<int, float> v, w;
    v = 12; // v contains int
    int i = std::get<int>(v);
    w = std::get<int>(v);
    w = std::get<0>(v); // same effect as the previous line
    w = v; // same effect as the previous line
 
//  std::get<double>(v); // error: no double in [int, float]
//  std::get<3>(v);      // error: valid index values are 0 and 1
 
    try {
      std::get<float>(w); // w contains int, not float: will throw
    }
    catch (const std::bad_variant_access&) {}
 
    using namespace std::literals;
 
    std::variant<std::string> x("abc");
    // converting constructors work when unambiguous
    x = "def"; // converting assignment also works when unambiguous
 
    std::variant<std::string, void const*> y("abc");
    // casts to void const * when passed a char const *
    assert(std::holds_alternative<void const*>(y)); // succeeds
    y = "xyz"s;
    assert(std::holds_alternative<std::string>(y)); // succeeds
}

Source: https://en.cppreference.com/w/cpp/utility/variant

Compiling this g++ works.

Code:

g++ -std=c++17 test.cpp -o test -v

And it will fail with clang++.

Code:

clang++ -std=c++17 test.cpp -o test -v

However as expected it works with -stdlib=libc++.

Code:

clang++ -std=c++17 -stdlib=libc++ test.cpp -o test -v

I next started a Slackware64-current chroot which I have not updated in a while which successfully compiles the demo using clang with and without stdlib=libc++.

Code:

gcc-g++-8.2.0-x86_64-1
llvm-7.0.1-x86_64-1

orbea · 05-09-2019, 05:59 PM

The issue seems like it could of started here.

https://gcc.gnu.org/viewcvs/gcc/trun...500&r2=270501&

orbea · 05-09-2019, 07:11 PM

With some help in the dolphin-emu irc channel I was suggested to make this change to /usr/include/c++/9.1.0/variant.

Code:

--- variant.orig        2019-05-09 16:49:37.963890851 -0700
+++ variant     2019-05-09 16:45:56.600805688 -0700
@@ -1556,7 +1556,7 @@
 #endif
 
       template<size_t _Np, typename _Vp>
-       friend constexpr decltype(auto) __detail::__variant::__get(_Vp&& __v);
+       friend constexpr decltype(auto) __detail::__variant::__get(_Vp&& __v) noexcept;
 
       template<typename _Vp>
        friend void* __detail::__variant::__get_storage(_Vp&& __v);

And now dolphin-emu builds successfully with clang++ and works.

I did have to disable my ccache to avoid the previous linker issues from mixing libstdc++ and libc++.

orbea · 05-16-2019, 09:16 AM

This is now solved in libstdc++ and current.

Fixed in: https://gcc.gnu.org/viewcvs/gcc?view...evision=271083

llvm issue report: https://bugs.llvm.org/show_bug.cgi?id=41863
gcc issue report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90397

Code:

Thu May 16 04:55:49 UTC 2019
d/gcc-g++-9.1.0-x86_64-5.txz: Rebuilt.
       Applied patch: PR libstdc++/90397 fix std::variant friend declaration
       This fixes problems compiling programs that use std::variant with clang.