[Bug libstdc++/64504] New: Invalid free() with _GLIBCXX_DEBUG and -fwhole-program

["andrey.vihrov at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64504

            Bug ID: 64504
           Summary: Invalid free() with _GLIBCXX_DEBUG and -fwhole-program
           Product: gcc
           Version: 4.9.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andrey.vihrov at gmail dot com

Created attachment 34383
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34383&action=edit
Preprocessed source

Compiling the following program:

#define _GLIBCXX_DEBUG

#include <iostream>
#include <string>

int main()
{
    std::string s;
    std::cin >> s;
}

with "g++ -fwhole-program x.cpp" gives me

*** Error in `./a.out': free(): invalid pointer: 0x00000000006017c0 ***
======= Backtrace: =========
/usr/lib/libc.so.6(+0x732ae)[0x7fb15966e2ae]
/usr/lib/libc.so.6(+0x7872e)[0x7fb15967372e]
/usr/lib/libc.so.6(+0x78eeb)[0x7fb159673eeb]
/usr/lib/libstdc++.so.6(_ZNSs7reserveEm+0xa4)[0x7fb159f7d3e4]
/usr/lib/libstdc++.so.6(_ZStrsIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RSbIS4_S5_T1_E+0x214)[0x7fb159f302f4]
./a.out[0x400b40]
/usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7fb15961b040]
./a.out[0x4009a9]

This is on 64-bit Arch Linux with GCC 4.9.2. My understanding of
-fwhole-program is that it can be used with one source file that includes
standard library headers and links with the standard library. If this is wrong,
then I'm sorry for filing a bogus bug report.

I have searched for similar reports and found bug #53838. And indeed the sample
program from that bug also crashes with the same message. However, my system
has only one GCC and libstdc++, unlike in that case.

gcc -v:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/4.9.2/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /build/gcc-multilib/src/gcc-4.9-20141224/configure
--prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared
--enable-threads=posix --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch
--disable-libssp --enable-gnu-unique-object --enable-linker-build-id
--enable-cloog-backend=isl --enable-lto --enable-plugin
--enable-install-libiberty --with-linker-hash-style=gnu --enable-multilib
--disable-werror --enable-checking=release
Thread model: posix
gcc version 4.9.2 20141224 (prerelease) (GCC)