[Bug libstdc++/97729] [11 Regression] Link failure due to basic_stringbuf and others when building DLL on MinGW

[markus.boeck02 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97729

--- Comment #4 from Markus Böck <markus.boeck02 at gmail dot com> ---
Indeed that sounds like it might be the issue. I am currently on a very recent
version of binutils:

$ ./x86_64-w64-mingw32-ld --version                            GNU ld (GNU
Binutils) 2.35.50.20200709                                                     
                            Copyright (C) 2020 Free Software Foundation, Inc.  
                                                                    This
program is free software; you may redistribute it under the terms of           
                                   the GNU General Public License version 3 or
(at your option) a later version.                                          
This program has absolutely no warranty.

Changing the lines you posted above yields me a compiler error now:

libtool: compile:  /mnt/c/GCC-Build-Array/gcc/build-host-x86_64/./gcc/xgcc
-shared-libgcc -B/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/./gcc -nostdinc++
-L/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/src
-L/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/src/.libs
-L/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/libsupc++/.libs
-L/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/x86_64-w64-mingw32/lib
-L/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/mingw/lib -isystem
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/x86_64-w64-mingw32/include
-isystem /mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/mingw/include
-B/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/x86_64-w64-mingw32/bin/
-B/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/x86_64-w64-mingw32/lib/
-isystem
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/x86_64-w64-mingw32/include
-isystem
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/x86_64-w64-mingw32/sys-include
-I/mnt/c/GCC-Build-Array/gcc/libstdc++-v3/../libgcc
-I/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/x86_64-w64-mingw32
-I/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include
-I/mnt/c/GCC-Build-Array/gcc/libstdc++-v3/libsupc++
-I/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/install/include -std=gnu++11
-D_GLIBCXX_SHARED -fno-implicit-templates -Wall -Wextra -Wwrite-strings
-Wcast-qual -Wabi=2 -fdiagnostics-show-location=once -ffunction-sections
-fdata-sections -frandom-seed=future.lo -Wno-error=format-extra-args
-Wno-error=format -g1 -fdebug-prefix-map=/mnt/c=C: -c
../../../../../libstdc++-v3/src/c++11/future.cc -o future.o
In file included from ../../../../../libstdc++-v3/src/c++11/future.cc:29:
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/future:
In member function 'std::__future_base::_Result<_Res>&
std::__basic_future<_Res>::_M_get_result() const':
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/future:712:30:
error: ambiguous overload for 'operator==' (operand types are
'std::__exception_ptr::exception_ptr' and 'int')
  712 |         if (!(__res._M_error == 0))
      |               ~~~~~~~~~~~~~~ ^~ ~
      |                     |           |
      |                     |           int
      |                     std::__exception_ptr::exception_ptr
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/future:712:30:
note: candidate: 'operator==(std::__exception_ptr::exception_ptr::__safe_bool
{aka void (std::__exception_ptr::exception_ptr::*)()},
std::__exception_ptr::exception_ptr::__safe_bool {aka void
(std::__exception_ptr::exception_ptr::*)()})' (built-in)
  712 |         if (!(__res._M_error == 0))
      |               ~~~~~~~~~~~~~~~^~~~
In file included from
/mnt/c/GCC-Build-Array/gcc/libstdc++-v3/libsupc++/exception:147,
                 from
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/mutex:40,
                 from
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/future:38,
                 from ../../../../../libstdc++-v3/src/c++11/future.cc:29:
/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/include/bits/exception_ptr.h:223:5:
note: candidate: 'bool std::__exception_ptr::operator==(const
std::__exception_ptr::exception_ptr&, const
std::__exception_ptr::exception_ptr&)'
  223 |     operator==(const exception_ptr&, const exception_ptr&)
      |     ^~~~~~~~
Makefile:644: recipe for target 'future.lo' failed
make[5]: Leaving directory
'/mnt/c/GCC-Build-Array/gcc/build-host-x86_64/x86_64-w64-mingw32/libstdc++-v3/src/c++11'