[Bug libstdc++/39237] New: Overloaded Operator delete not called

[Bug libstdc++/39237] New: Overloaded Operator delete not called

[caroline dot rioux at ca dot ibm dot com]

Hello,

We use a unit testing framework which overloads operator new and operator
delete to track memory allocations and detect leaks.  According to it, vector's
push_back method allocates memory through operator new but does not release it
through operator delete.

I am not sure if this is because the memory is not released, is not released
through delete, or that the overloaded operator is simply not called.

The simple test case is as follows;

----
#include <vector>
#include <iostream>

int main (int argc, char ** argv) 
{
  {
        std::vector< int > objects;
        objects.push_back(1);
  }
  return 0;
}

static int allocatedBlocks = 0;

void* operator new(size_t size)
{
        allocatedBlocks++;
        void * toReturn = malloc(size);
        std::cerr << "operator new(size = " << size 
                  << "), returns: " << toReturn 
                  << " allocatedBlocks: " << allocatedBlocks << std::endl;
        return toReturn;
}

void operator delete(void* mem)
{
        if(mem == NULL)
          return;
        allocatedBlocks--;
        std::cerr << "operator delete(mem = " << mem << ") allocatedBlocks: "
<< allocatedBlocks << std::endl;
        free(mem);
}
-----

Using gcc 3.2.3, running this program yields the following output:

operator new(size = 320), returns: 0x503010 allocatedBlocks: 1

Using gcc 4.1.2, I get the expected:

operator new(size = 4), returns: 0x503010 allocatedBlocks: 1
operator delete(mem = 0x503010) allocatedBlocks: 0

I read in the FAQ that containers save memory for later re-use, but shouldn't
it be released when the vector goes out of scope? 

Please see the preprocessed source (attached) and the g++ information below.

--------------
/home/riouxc/temp> g++ -v -save-temps simple_vector.cpp 
Reading specs from /isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--disable-checking --with-system-zlib --enable-__cxa_atexit
--enable-languages=c,c++ --disable-libgcj --host=x86_64-redhat-linux
Thread model: posix
gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3)
 /isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/cpp0 -lang-c++
-D__GNUG__=3 -D__DEPRECATED -D__EXCEPTIONS -v -iprefix
/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/ -D__GNUC__=3
-D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=3 -D__GXX_ABI_VERSION=102 -D__ELF__
-Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__
-D__unix -D__linux -Asystem(posix) -D__NO_INLINE__ -D__STDC_HOSTED__=1
-D_GNU_SOURCE -Acpu=x86_64 -Amachine=x86_64 -D__x86_64 -D__x86_64__
-D__SIZE_TYPE__=unsigned long int -D__PTRDIFF_TYPE__=long int -D__tune_athlon__
-D__tune_athlon_sse__ -D__LONG_MAX__=9223372036854775807L -D__LP64__ -D_LP64
simple_vector.cpp simple_vector.ii
GNU CPP version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3) (cpplib) (x86-64
Linux/ELF)
ignoring nonexistent directory "/isv/gnu/bin/../x86_64-redhat-linux/include"
ignoring nonexistent directory "/usr/x86_64-redhat-linux/include"
ignoring duplicate directory "/usr/include/c++/3.2.3"
ignoring duplicate directory "/usr/include/c++/3.2.3/x86_64-redhat-linux"
ignoring duplicate directory "/usr/include/c++/3.2.3/backward"
ignoring duplicate directory
"/usr/lib/gcc-lib/x86_64-redhat-linux/3.2.3/include"
#include "..." search starts here:
#include <...> search starts here:
 /isv/gnu/bin/../include/c++/3.2.3
 /isv/gnu/bin/../include/c++/3.2.3/x86_64-redhat-linux
 /isv/gnu/bin/../include/c++/3.2.3/backward
 /isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/include
 /usr/local/include
 /usr/include
End of search list.
 /isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/cc1plus -fpreprocessed
simple_vector.ii -quiet -dumpbase simple_vector.cpp -version -o simple_vector.s
GNU CPP version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3) (cpplib) (x86-64
Linux/ELF)
GNU C++ version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3) (x86_64-redhat-linux)
        compiled by GNU C version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3).
 as -V -Qy -o simple_vector.o simple_vector.s
GNU assembler version 2.15.92.0.2 (x86_64-redhat-linux) using BFD version
2.15.92.0.2 20040927
 /isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/collect2 --eh-frame-hdr
-m elf_x86_64 -Y P,/usr/lib64 -dynamic-linker /lib64/ld-linux-x86-64.so.2
/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../../../lib64/crt1.o
/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../../../lib64/crti.o
/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/crtbegin.o
-L/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3
-L/isv/gnu/bin/../lib/gcc-lib -L/usr/lib/gcc-lib/x86_64-redhat-linux/3.2.3
-L/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../../../lib64
-L/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../..
-L/usr/lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../../../lib64
-L/usr/lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../.. -L/lib/../lib64
-L/usr/lib/../lib64 simple_vector.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s
-lgcc /isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/crtend.o
/isv/gnu/bin/../lib/gcc-lib/x86_64-redhat-linux/3.2.3/../../../../lib64/crtn.o


-- 
           Summary: Overloaded Operator delete not called
           Product: gcc
           Version: 3.2.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: caroline dot rioux at ca dot ibm dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39237

[Bug libstdc++/39237] Overloaded Operator delete not called

[caroline dot rioux at ca dot ibm dot com]

------- Comment #1 from caroline dot rioux at ca dot ibm dot com  2009-02-18 21:39 -------
Created an attachment (id=17327)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17327&action=view)
Preprocessed source


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39237

[Bug libstdc++/39237] Overloaded Operator delete not called

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2009-02-18 21:45 -------
Fixed in 4.1.0 as mentioned already.  3.3.x is no longer maintained and any bug
that is reported against that old version is most likely not going to be ever
fixed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39237

[Bug libstdc++/39237] Overloaded Operator delete not called

[caroline dot rioux at ca dot ibm dot com]

------- Comment #3 from caroline dot rioux at ca dot ibm dot com  2009-02-18 22:02 -------
(In reply to comment #2)
> Fixed in 4.1.0 as mentioned already.  3.3.x is no longer maintained and any bug
> that is reported against that old version is most likely not going to be ever
> fixed.
> 

Ok thanks for your input. Was this explicitly fixed or a result of other
framework changes?  Is there any way a patch exists and could be applied?

I ask because it is unlikely we will move to gcc4 in the short term. Is
gcc3.4.x still supported? Because it also occurs there.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39237

[Bug libstdc++/39237] Overloaded Operator delete not called

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2009-02-18 22:06 -------
(In reply to comment #3)
> Ok thanks for your input. Was this explicitly fixed or a result of other
> framework changes?  Is there any way a patch exists and could be applied?

Off hand I don't know.

> I ask because it is unlikely we will move to gcc4 in the short term. Is
> gcc3.4.x still supported? Because it also occurs there.

Nope, only currently 4.2 and above are being maintained.  Is there a reason why
you unlikely to move to 4.x in the short term? 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39237

[Bug libstdc++/39237] Overloaded Operator delete not called

[caroline dot rioux at ca dot ibm dot com]

------- Comment #5 from caroline dot rioux at ca dot ibm dot com  2009-02-18 22:15 -------
(In reply to comment #4)
> Nope, only currently 4.2 and above are being maintained.  Is there a reason why
> you unlikely to move to 4.x in the short term? 

We have a big code base and changing compilers is done seldom and very
carefully.  This bug will be one more reason to move though, so that's good :)

Is there any way you would know exactly what the bug is in this case? Is it a
leak, or that the memory is not free'd through delete, or that the overloaded
operator is not called when it should?  I searched the bug database but
couldn't find anything similar. 

Thanks again!


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39237