[Bug c++/15764] New: no cleanup if temporary's dtor terminates with an exception

[Bug c++/15764] New: no cleanup if temporary's dtor terminates with an exception

[boris at kolpackov dot net]

$ cat >test.cxx

#include <cstdlib>

struct a
{
  ~a ()
  {
    throw 1;
  }
};

int 
f (a const& acr = a ())
{
  return 1;
}

struct b
{
  b (int)
  {
  }

  ~b ()
  {
    std::abort ();
  }
};

int
main ()
{
  try
  {
    b b_ (f ());    
  } 
  catch (...) {}
}

$ g++ -v
Reading specs from /home/boris/local/lib/gcc/x86_64-unknown-linux-gnu/3.4.0/specs
Configured with: /home/boris/gcc-3.4.0/configure --prefix=/home/boris/local
--enable-__cxa_atexit --enable-languages=c,c++ --enable-long-long
--with-system-zlib --enable-shared --disable-multilib
Thread model: posix
gcc version 3.4.0

$ g++ test.cxx
$ ./a.out

I tried it on Intel C++ 8.0 and Compaq C++ 6.5-040 and they both call b::~b.

-boris

-- 
           Summary: no cleanup if temporary's dtor terminates with an
                    exception
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: boris at kolpackov dot net
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-01 17:13 -------
    b b_ (f ());    

b is not initialized when ~a throws as it is equivant to
int i;
{
  const a &c= a();
  i = f(c);
}
b b_ (i);

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-06-01 17:45 -------
Andrew is right: b::b() isn't called (as you can easily verify by 
placing another call to std::abort into the constructor). Thus, 
there shouldn't be any call to the destructor either. 
 
W. 

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[boris at kolpackov dot net]

------- Additional Comments From boris at kolpackov dot net  2004-06-01 17:52 -------
$ cat >test.cxx

#include <iostream>

using std::cerr;
using std::endl;

struct a
{
  ~a ()
  {
    throw 1;
  }
};

int 
f (a const& acr = a ())
{
  return 1;
}

struct b
{
  b (int)
  {
    cerr << "b" << endl;
  }

  ~b ()
  {
    cerr << "~b" << endl;
    // std::abort ();
  }
};

int
main ()
{
  try
  {
    b b_ (f ());    
  } 
  catch (...) {}
}

$ g++ test.cxx
$ ./a.out
b
$ #?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-06-01 18:15 -------
Alright, I shouldn't first reduce and then draw conclusions. The 
call to f() is the necessary step. Here is a slightly smaller testcase: 
 
------------------ 
extern "C" void abort (); 
 
int counter = 0; 
 
struct a { 
  ~a () { throw 1; } 
}; 
 
int f (a const&) { return 1; } 
 
struct b { 
  b (...) { ++counter; } 
  ~b ()   { --counter; } 
}; 
 
int main () { 
  try { b tmp(f (a())); }  
  catch (...) {} 
 
  if (counter != 0) 
    abort (); 
} 
-------------- 
 
In 
  b tmp(f(a())); 
the call to a::a() throws, so f return prematurely, and we shouldn't 
even start to construct tmp. However, we do, thus incrementing the 
counter. Then we fail to run the destructor, though. 
 
W. 

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-06-01 18:16 -------
Confirmed, indeed, with 2.95 through mainline. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-06-01 18:16:26
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[boris at kolpackov dot net]

------- Additional Comments From boris at kolpackov dot net  2004-06-01 18:18 -------
> the call to a::a() throws
              ^^^^^^
              a::~a()



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-06-01 18:29 -------
Gee, yes, I can't seem to read code today. Since the lifetime 
of the temporary a() is until the end of the expression, the 
variable tmp is fully constructed. It needs to be destroyed  
again as part of the cleanup to be done when a::~a throws, 
but isn't. 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764

[Bug c++/15764] no cleanup if temporary's dtor terminates with an exception

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-10-15 02:20 -------
The try/finally block for the tmp is not around the initializer, why?

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
   Last reconfirmed|2004-06-01 18:16:26         |2004-10-15 02:20:26
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15764