[Bug libstdc++/110572] ld.lld: error: duplicate symbol: std::type_info::operator==(std::type_info const&) const
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110572
peter0x44 at disroot dot org changed:
What|Removed |Added
CC||peter0x44 at disroot dot org
--- Comment #5 from peter0x44 at disroot dot org ---
#include
int main() { return typeid(0) == typeid(0); }
The following reproduces for me, although strangely only with -std=c++23 and
-static-libstdc++.
x86_64-w64-mingw32-g++ test.cpp -static-libstdc++ -std=c++20
// no error
x86_64-w64-mingw32-g++ test.cpp -static-libstdc++ -std=c++23
/usr/lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld:
/usr/lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libstdc++.a(tinfo.o):
in function `std::type_info::operator==(std::type_info const&) const':
/build/mingw-w64-gcc/src/gcc/libstdc++-v3/libsupc++/tinfo.cc:42: multiple
definition of `std::type_info::operator==(std::type_info const&) const';
/tmp/ccyAJVlk.o:test.cpp:(.text$_ZNKSt9type_infoeqERKS_[_ZNKSt9type_infoeqERKS_]+0x0):
first defined here
Related issue:
https://github.com/skeeto/w64devkit/issues/86
[Bug libstdc++/110572] ld.lld: error: duplicate symbol: std::type_info::operator==(std::type_info const&) const
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110572 --- Comment #4 from Thomas Arndt --- Sounds good, I would agree on your solution as well. So since it's not related to clang and can be reproduced with gcc is there a fix planned?
[Bug libstdc++/110572] ld.lld: error: duplicate symbol: std::type_info::operator==(std::type_info const&) const
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110572 --- Comment #3 from Jonathan Wakely --- N.B. this can be reproduced without clang, just by using -std=c++20 -static-libstdc++ /usr/bin/x86_64-w64-mingw32-ld: /home/jwakely/gcc/mingw/lib/gcc/x86_64-w64-mingw32/13.0.1/../../../../x86_64-w64-mingw32/lib/../lib/libstdc++.a(tinfo.o): in function `std::type_info::operator==(std::type_info const&) const': /home/jwakely/src/gcc/build-mingw64/x86_64-w64-mingw32/libstdc++-v3/libsupc++/../../../../gcc/libstdc++-v3/libsupc++/tinfo.cc:61: multiple definition of `std::type_info::operator==(std::type_info const&) const'; /tmp/ccmMqprE.o:/home/jwakely/gcc/mingw/x86_64-w64-mingw32/include/c++/13.0.1/typeinfo:194: first defined here collect2: error: ld returned 1 exit status
[Bug libstdc++/110572] ld.lld: error: duplicate symbol: std::type_info::operator==(std::type_info const&) const
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110572 Jonathan Wakely changed: What|Removed |Added Ever confirmed|0 |1 Target Milestone|--- |12.4 Last reconfirmed||2023-07-06 Status|UNCONFIRMED |NEW Keywords||ABI --- Comment #2 from Jonathan Wakely --- Prior to r12-6266-g3633cc54284450 making the definition in tinfo.cc inline would have meant it is never emitted into tinfo.o (unless __attribute__((used)) was added to it). Since the __equal alias, the operator== definition is always used, so it will still generate a symbol even if it's an inline function. But I'm not sure adding 'inline' there will actually fix anything. I still see it produce the same symbol whether inline or not: T _ZNKSt9type_info7__equalERKS_ T _ZNKSt9type_infoeqERKS_ I'm also concerned that the __equal function could end up in infinite recursion. If you compile C++20 code then the inline definition of type_info::operator== in the header is used, which calls type_info::__equal, which is an alias for type_info::operator==. If the alias doesn't bind locally then it could call the inline definition from the header again, and recurse. I think a better fix would be to declare the operator== in the header with __attribute__((__always_inline__)). That will ensure there is never a symbol emitted for that inline definition, and so no multiple definition errors.
[Bug libstdc++/110572] ld.lld: error: duplicate symbol: std::type_info::operator==(std::type_info const&) const
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110572 --- Comment #1 from Jonathan Wakely --- I would argue that the root cause is that Clang does not conform to the platform ABI for mingw-w64, which requires __GXX_TYPEINFO_EQUALITY_INLINE=0 to be defined.
