Re: c++/9075: Destructor is called more times than required..

Re: c++/9075: Destructor is called more times than required..

[lerdsuwa]

Synopsis: Destructor is called more times than required..

State-Changed-From-To: open->closed
State-Changed-By: lerdsuwa
State-Changed-When: Sun Dec 29 10:16:30 2002
State-Changed-Why:
    Not a bug.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9075

Re: c++/9075: Destructor is called more times than required..

[Andrew Pinski]

The following reply was made to PR c++/9075; it has been noted by GNATS.

From: Andrew Pinski <pinskia@physics.uc.edu>
To: sunil.k.davasam@intel.com
Cc: Andrew Pinski <pinskia@physics.uc.edu>, gcc-gnats@gcc.gnu.org
Subject: Re: c++/9075: Destructor is called more times than required..
Date: Fri, 27 Dec 2002 23:16:07 -0500

 This is not a bug because func's c is not a reference to a variable but 
 a variable that is copied.
 If you want a function that does not copy, then use a `&' and then the 
 destructor is not called twice, only once.
 
 Read a C++ book for more information about pass by value, not reference.
 
 Thanks,
 Andrew Pinski
 
 On Friday, Dec 27, 2002, at 22:46 US/Eastern, sunil.k.davasam@intel.com 
 wrote:
 
 >
 > void func(C c)
 > {
 >     printf("func()\n");
 > }
 >
 > int main(void)
 > {
 >     C c;
 >
 >     func(c);
 >     printf("main()\n");
 >     return 0;
 > }
 >
 

c++/9075: Destructor is called more times than required..

[sunil.k.davasam]

>Number:         9075
>Category:       c++
>Synopsis:       Destructor is called more times than required..
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Dec 27 19:56:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     sunil.k.davasam@intel.com
>Release:        g++3.2
>Organization:
>Environment:
$ g++ -v
Reading specs from /local/skdavasa/gcc321/lib/gcc-lib/i386-redhat-linux/3.2.1/specs
Configured with: gcc-3.2.1/configure --prefix=/local/skdavasa/gcc321 --enable-shared --enable-threads=posix --disable-checking --host=i386-redhat-linux --with-system-zlib --enable-__cxa_atexit
Thread model: posix
gcc version 3.2.1
$ cat /etc/issue
Red Hat Linux release 8.0 (Psyche)
Kernel \r on an \m
>Description:
I have a small testcase.

[skdavasa@yeti testing]$ cat t1.cpp 
#include <stdio.h>

class C {
  public:
    C() { 
            printf("C()\n");
    }
    ~C() { 
            printf("~C()\n"); 
    }
};


void func(C c)
{
    printf("func()\n");
}

int main(void)
{
    C c;

    func(c);
    printf("main()\n");
    return 0;
}

  When I compiled and ran the above the test case, I found that destructor is called twice, where as constructor is called only once. I think it is wrong.
>How-To-Repeat:
$ g++ t1.cpp 
$ a.out
C()
func()
~C()
main()
~C()
---

Where as expected output:
------
C()
func()
main()
~C()
--------
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: text/plain; name="t1.cpp"
Content-Disposition: inline; filename="t1.cpp"

#include <stdio.h>

class C {
  public:
    C() { 
	    printf("C()\n");
    }
    ~C() { 
	    printf("~C()\n"); 
    }
};


void func(C c)
{
    printf("func()\n");
}

int main(void)
{
    C c;

    func(c);
    printf("main()\n");
    return 0;
}