IY94697: operator delete called twice on exception

April 2007 VisualAge C++ Professional V6.0 for AIX PTF

APAR status

• Closed as program error.

Error description

• Using a custom operator delete, the testcase (below) shows that
  it is called twice:
  once after a throw, and once again after the exception has been
  cauaght and handled.
  
  <test.cc>
  #include <stdio.h>
  #include <cstdlib>
  #include <new>
  
  void* operator new(size_t size) throw(std::bad_alloc)
  {
      void* p=(void*)malloc(size);
      printf("operator new(size_t %d): %#lx\n", size, p);
      return p;
  }
  
  void operator delete(void *p) throw()
  {
      printf("operator delete: %#lx\n", p);
      //free(p);
  }
  
  class A {
  public:
  
      A()  {
          printf("A::A():constructor   this=%#lx\n", this);
      };
  
      A(const A& a) {
          printf("A::A(const A&):copy constructor   this=%#lx
  copy=%#lx\n", this, a);
          *this = a;
      };
  
      virtual ~A() {
          printf("A::~A():destructor   this=%#lx\n", this);
      };
  
      A& operator=(const A& a) {
          printf("A::operator=:assignment operator   this=%#lx\n",
  this);
          return *this;
      };
  };
  
  class B {
  public:
  
      B() {
          obj = 0;
          printf("B::B():constructor   this=%#lx\n", this);
      };
  
      B(A *o) {
          obj = o;
          printf("B::B(B *):constructor   this=%#lx   obj=%#lx\n",
  this, o);
      };
  
      B(const B& b) {
          printf("B::B(const B&):copy constructor   this=%#lx
  copy=%#lx\n", this, b);
          *this = b;
      };
  
      B& operator=(const B& b) {
          obj = b.obj;
          printf("B::operator=:assignment operator   this=%#lx
  copy=%#lx\n", this, b);
          return *this;
      };
  
      virtual ~B() {
          printf("B::~B():destructor   this=%#lx   obj=%#lx\n",
  this, obj);
          if (obj) {
              delete obj;
          };
      };
  
      A* obj;
  };
  
  class C {
  public:
      C() {};
      virtual ~C() {};
  };
  
  inline A * hide_work() {
    return new A(A());
  }
  
  int main(int argc, char *argv[])
  {
      printf("Memory of object destroyed before end of life\n");
      B *b;
      try {
          printf("main:try before\n");
          b= new B(new A(A()));
  //        b= new B(hide_work()); // using this instead is safe
          printf("main:try after\n");
  //        C c; // strange workaround
          printf("main:before exception\n");
          throw 1;
      }
      catch (...) {
          printf("main:in exception\n");
      }
      printf("main:after catch\n");
      delete b;
      printf("main:end\n");
  }
  </test.cc>
  

Local fix

• Create another local variable before the throw.
  or
  Use call a function to create the temporary variables instead of
  doing this inline to the creation of the new B object.
  (You could create locals to hold those values as well and things
  would work.)
  

Problem summary

• TBD
  

Problem conclusion

• TBD
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  IY99559 IZ01350

Fix information

• Fixed component name

  VA C++ PROF FOR

• Fixed component ID

  5765F5600

Applicable component levels

• R600 PSY U811611

     UP07/04/30 I 1000

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Product categories:

Software

Software Development

Analysis, Modeling, Design & Construction

VisualAge C++

Compiler

Software version:

600

Reference #:

IY94697

IBM Group:

Software Group

Modified date:

2007-06-22