[Bug target/65344] New: Exception is not catched on AIX - class with more ancestors, virtual method throws

[jezz at hkfree dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65344

            Bug ID: 65344
           Summary: Exception is not catched on AIX - class with more
                    ancestors, virtual method throws
           Product: gcc
           Version: 4.8.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jezz at hkfree dot org

Created attachment 34983
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34983&action=edit
Sources for reproducing

In my program exception is not catched, when it is compiled with gcc newer than
4.4 (4.2.4 & 4.4.7 works). I have created sample (sample with Makefile in in
attachment). I have tested the sample with 4.5.4 and 4.8.3 - both fails. All
compilers are from http://www.perzl.org/aix/index.php?n=Main.Gcc

This is output from sample compiled with 4.4.7:

./main 
Case 1:

Case 2:
(Class*)ThrowingClass=0x0x200013b8
(DoThrowIface*)this=0x0x200013bc
(DoThrowIface*)ThrowingClass=0x0x200013bc
Called doThrow.
Thrown && catched BaseException.
End.

This is output from sample compiled with 4.8.3:
 ./main 
Case 1:

Case 2:
(Class*)ThrowingClass=0x0x20001ab8
(DoThrowIface*)this=0x0x20001abc
(DoThrowIface*)ThrowingClass=0x0x20001abc
Called doThrow.
terminate called after throwing an instance of 'Exception'

(gdb) where
#0  0xd37bd440 in raise () from /usr/lib/libc.a(shr.o)
#1  0xd384bca8 in abort () from /usr/lib/libc.a(shr.o)
#2  0xd8055610 in __gnu_cxx::__verbose_terminate_handler () at  _start_ :95
#3  0xd80609ec in __cxxabiv1::__terminate (handler=<incomplete type>)
    at  _start_ :38
#4  0xd8055404 in std::terminate () at  _start_ :48
#5  0xd8060d7c in __cxa_throw (obj=<incomplete type>, 
    tinfo=<incomplete type>, dest=<incomplete type>) at  _start_ :87
#6  0x10001604 in ThrowingClass::doThrow (this=0x20001ab8)
    at throwing_class.cc:24
#7  0x100006a8 in main (argc=1, argv=0x2ff22af4) at main.cc:39

g++ -v:
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/freeware/libexec/gcc/powerpc-ibm-aix6.1.0.0/4.8.3/lto-wrapper
Target: powerpc-ibm-aix6.1.0.0
Configured with: ../gcc-4.8.3/configure --with-as=/usr/bin/as
--with-ld=/usr/bin/ld --enable-languages=c,c++,fortran --prefix=/opt/freeware
--mandir=/opt/freeware/man --infodir=/opt/freeware/info
--enable-version-specific-runtime-libs --disable-nls --enable-decimal-float=dpd
--host=powerpc-ibm-aix6.1.0.0
Thread model: aix
gcc version 4.8.3 (GCC) 


Sample sources:

base.hh:
#ifndef BASE_HH
#define BASE_HH 1

class Exception
   {
   public:
      Exception() {}
   };

class Iface
   {
   public:
      virtual ~Iface() {}
   };

class Class
   {
   public:
      virtual ~Class() {}
      virtual Iface *getIface() = 0;
   };

class DoThrowIface
   : public Iface
   {
   public:
      virtual void doThrow() = 0;
   };

class Registrator
   {
   public:
      virtual Class* getClass() = 0;
   };

#endif /* BASE_HH */

throwing_class.hh:
#ifndef THROWING_CLASS_HH
#define THROWING_CLASS_HH 1

class ThrowingClass
   : public Class
   , public DoThrowIface
   {
   public:
      virtual void doThrow();
      virtual Iface *getIface();
   };

#endif /* THROWING_CLASS_HH */

throwing_class.cc:
#include <iostream>
#include "base.hh"
#include "throwing_class.hh"

extern Registrator *reg;

// This class must be in separate object file
class ThrowingClassRegistrator : public Registrator
   {
   public:
      ThrowingClassRegistrator()
         {
         reg = this;
         }
      virtual Class *getClass()
         {
         return new ThrowingClass();
         }
   } ThrowingClassRegistrator_I;

void ThrowingClass::doThrow()
   {
   std::cout << "Called doThrow." << std::endl;
   throw Exception();
   }

Iface *ThrowingClass::getIface()
   {
   std::cout << "(DoThrowIface*)this=0x" << (DoThrowIface*)this << std::endl;
   return static_cast<DoThrowIface*>(this);
   }


main.cc:
#include <iostream>
#include <exception>
#include "base.hh"
#include "throwing_class.hh"

Registrator *reg;

int
main(int argc, char *argv[])
   {
   std::cout << "Case 1:" << std::endl;
   try
      {
      // This always works, but if I uncomment this, case 2 is also working.
      /*
      Class *throwingClass = new ThrowingClass();
      std::cout << "(Class*)ThrowingClass=0x" << throwingClass << std::endl;
      DoThrowIface *throwIface = (DoThrowIface *)throwingClass->getIface();
      std::cout << "(DoThrowIface*)ThrowingClass=0x" << throwIface <<
std::endl;
      throwIface->doThrow();
      //*/
      }
   catch (Exception const& e)
      {
      std::cout << "Thrown && catched BaseException." << std::endl;
      }
   catch (...)
      {
      std::cout << "General catch." << std::endl;
      }

   std::cout << std::endl << "Case 2:" << std::endl;
   try
      {
      Class *throwingClass = reg->getClass();
      std::cout << "(Class*)ThrowingClass=0x" << throwingClass << std::endl;
      DoThrowIface *throwIface = (DoThrowIface *)throwingClass->getIface();
      std::cout << "(DoThrowIface*)ThrowingClass=0x" << throwIface <<
std::endl;
      throwIface->doThrow();
      }
   catch (Exception const& e)
      {
      std::cout << "Thrown && catched BaseException." << std::endl;
      }
   catch (...)
      {
      std::cout << "General catch." << std::endl;
      }
   std::cout << "End." << std::endl;
   return 0;
   }