[Bug lto/58922] New: LTO undefined symbols with virtual destructor

[Bug lto/58922] New: LTO undefined symbols with virtual destructor

[jamiespence2 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58922

            Bug ID: 58922
           Summary: LTO undefined symbols with virtual destructor
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jamiespence2 at gmail dot com

Created attachment 31111
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31111&action=edit
Small project to demonstrate virtual destructor with LTO

There seems to be an issue when compiling/Linking with LTO enabled with GCC
4.8.1. I get undefined references to symbols in a DLL even though they seem to
be present. With LTO disabled it compiles and links successfully. 

Dependency walker shows the symbols are present in the DLL. LTO can't seem to
find them.
Removing LTO optimization makes everything compile successfully, I'm wondering
why this is an issue.

Attached a small project which demonstrates the problem. 

GCC information: MinGW-Builds 4.8.1
>gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=c:/mingw32/bin/../libexec/gcc/i686-w64-mingw32/4.8.1/lto-wrapper.exe
Target: i686-w64-mingw32
Configured with: ../../../src/gcc-4.8.1/configure --host=i686-w64-mingw32
--build=i686-w64-mingw32 --target=i686-w64-mingw32 --prefix=/mingw32
--with-sysroot=/tmp/x32-481-win32-dwarf-r5/mingw32 --enable-shared
--enable-static --disable-multilib
--enable-languages=ada,c,c++,fortran,objc,obj-c++,lto
--enable-libstdcxx-time=yes --enable-threads=win32 --enable-libgomp
--enable-lto --enable-graphite --enable-checking=release
--enable-fully-dynamic-string --enable-version-specific-runtime-libs
--disable-sjlj-exceptions --with-dwarf2 --disable-isl-version-check
--disable-cloog-version-check --disable-libstdcxx-pch --disable-libstdcxx-debug
--enable-bootstrap --disable-rpath --disable-win32-registry --disable-nls
--disable-werror --disable-symvers --with-gnu-as --with-gnu-ld --with-arch=i686
--with-tune=generic --with-libiconv --with-system-zlib
--with-gmp=/tmp/mingw-prereq/i686-w64-mingw32-static
--with-mpfr=/tmp/mingw-prereq/i686-w64-mingw32-static
--with-mpc=/tmp/mingw-prereq/i686-w64-mingw32-static
--with-isl=/tmp/mingw-prereq/i686-w64-mingw32-static
--with-cloog=/tmp/mingw-prereq/i686-w64-mingw32-static
--enable-cloog-backend=isl --with-pkgversion='rev5, Built by MinGW-W64 project'
--with-bugurl=http://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe
-I/tmp/x32-481-win32-dwarf-r5/libs/include -I/tmp/mingw-prereq/x32-zlib/include
-I/tmp/mingw-prereq/i686-w64-mingw32-static/include' CXXFLAGS='-O2 -pipe
-I/tmp/x32-481-win32-dwarf-r5/libs/include -I/tmp/mingw-prereq/x32-zlib/include
-I/tmp/mingw-prereq/i686-w64-mingw32-static/include' CPPFLAGS= LDFLAGS='-pipe
-L/tmp/x32-481-win32-dwarf-r5/libs/lib -L/tmp/mingw-prereq/x32-zlib/lib
-L/tmp/mingw-prereq/i686-w64-mingw32-static/lib
-L/tmp/x32-481-win32-dwarf-r5/mingw32/opt/lib -Wl,--large-address-aware'
Thread model: win32
gcc version 4.8.1 (rev5, Built by MinGW-W64 project)