[Bug libgcc/66212] New: Exception handling broken on powerpc

[Bug libgcc/66212] New: Exception handling broken on powerpc

[andri.yngvason at marel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66212

            Bug ID: 66212
           Summary: Exception handling broken on powerpc
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: libgcc
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andri.yngvason at marel dot com
  Target Milestone: ---

All exceptions cause the running process to be aborted.

The following program is aborted when trying to unwind the stack:
#include <exception>
#include <stdexcept>
#include <iostream>

using std::cout;
using std::endl;

void foobar()
{
    cout << "..." << endl;
    throw std::runtime_error("Whoohoo");
    cout << "Wtf?" << endl;
}

int main(int, char**)
{
    cout << "Throwing standard exception..." << endl;

    try {
        foobar();
    } catch(std::exception& e) {
        cout << "Caught: " << e.what() << endl;
    }

    cout << "Done!" << endl;

    return 0;
}

Backtrace:
#0  0x0fbff76c in raise () from /lib/libc.so.6
#1  0x0fc010cc in abort () from /lib/libc.so.6
#2  0x0fd5fc1c in uw_init_context_1 () from /lib/glibc2.21/libgcc_s.so.1
#3  0x0fd60408 in _Unwind_RaiseException () from /lib/glibc2.21/libgcc_s.so.1
#4  0x0fed10ac in __cxa_throw () at
../../../../gcc-5.1.0/libstdc++-v3/libsupc++/eh_throw.cc:82
#5  0x10000c28 in foobar() ()
#6  0x10000cac in main ()

$ powerpc-marel-linux-gnu-g++ -v 
Using built-in specs.
COLLECT_GCC=powerpc-marel-linux-gnu-g++
COLLECT_LTO_WRAPPER=/opt/plutotoolchain/libexec/gcc/powerpc-marel-linux-gnu/5.1.0/lto-wrapper
Target: powerpc-marel-linux-gnu
Configured with: ../gcc-5.1.0/configure --prefix=/opt/plutotoolchain
--target=powerpc-marel-linux-gnu --enable-languages=c,c++
--enable-threads=posix --enable-shared --disable-multilib --enable-__cxa_atexit
--disable-sjlj-exceptions --disable-nls --enable-symvers=gnu --enable-c99
--enable-long-long --enable-profile --with-tune=e300c3 --disable-altivec
Thread model: posix
gcc version 5.1.0 (GCC) 

I tried to compile libgcc with debug symbols so that I could see which
assertion fails, but my attempts had no effect. I'd be happy to learn how to
get those debug symbols in there.

[Bug libgcc/66212] Exception handling broken on powerpc

[andri.yngvason at marel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66212

--- Comment #1 from Andri Yngvason <andri.yngvason at marel dot com> ---
I've now compiled the same toolchain for i686 and I have the same issue there,
so I assume that I'm doing something wrong. It's hard to pin down what I'm
doing wrong though. Everything seems to be linked correctly:

# ldd stdexcept             
        linux-gate.so.1 (0xb77ad000)
        libstdc++.so.6 => /lib/libstdc++.so.6 (0xb7633000)
        libm.so.6 => /lib/libm.so.6 (0xb75ea000)
        libgcc_s.so.1 => /lib/glibc2.21/libgcc_s.so.1 (0xb75ce000)
        libc.so.6 => /lib/libc.so.6 (0xb7420000)
        /lib/ld-linux.so.2 (0xb77ae000)

# ls -l /lib/libstdc++.so.6 /lib/libm.so.6 /lib/libc.so.6
/lib/glibc2.21/libgcc_s.so.1 /lib/ld-linux.so.2                                 
-rw-r--r--    1 root     root        397872 May 20 10:11
/lib/glibc2.21/libgcc_s.so.1
lrwxrwxrwx    1 root     root            10 May 20 10:57 /lib/ld-linux.so.2 ->
ld-2.21.so
lrwxrwxrwx    1 root     root            12 May 20 10:57 /lib/libc.so.6 ->
libc-2.21.so
lrwxrwxrwx    1 root     root            12 May 20 10:57 /lib/libm.so.6 ->
libm-2.21.so
lrwxrwxrwx    1 root     root            19 May 20 10:57 /lib/libstdc++.so.6 ->
libstdc++.so.6.0.21

I'll try 4.9...

[Bug libgcc/66212] Exception handling broken on powerpc

[wilson at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66212

--- Comment #2 from Jim Wilson <wilson at gcc dot gnu.org> ---
libgcc should be built with debug info by default, but the one in /lib is
probably stripped.  Try setting LD_LIBRARY_PATH to point at the gcc-5.1
libraries that you built, instead of using the default ones provided by the OS
in /lib.

[Bug libgcc/66212] Exception handling broken on powerpc

[andri.yngvason at marel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66212

--- Comment #3 from Andri Yngvason <andri.yngvason at marel dot com> ---
This is the libgcc that I built. I put it there. However, it is entirely within
the realm of possibility that it may have been stripped on it's way there via
dpkg. I'll try copying it there directly. Thanks!

[Bug libgcc/66212] Exception handling broken on powerpc

[andri.yngvason at marel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66212

Andri Yngvason <andri.yngvason at marel dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #4 from Andri Yngvason <andri.yngvason at marel dot com> ---
I downloaded everything again and started from scratch. I've no idea what was
wrong but now the problem is gone. Mea culpa.