c++/6052: calls to allocator::~allocator made for empty class

c++/6052: calls to allocator::~allocator made for empty class

[georgeh]

>Number:         6052
>Category:       c++
>Synopsis:       calls to allocator::~allocator made for empty class
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          pessimizes-code
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 25 07:36:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     George Heintzelman <georgeh@aya.yale.edu>
>Release:        gcc-3.0.4
>Organization:
>Environment:
Solaris 2.8
>Description:
In the following code:
#include <string>

int main() {
  for (int i = 0; i < 100000; ++i) {
    std::string foo("Hello world");
  }
}

g++ generates calls to empty std::allocator::~allocator routines,
as well as empty std::string::Alloc_hider::~Alloc_hider routines,
within the loop.
>How-To-Repeat:
compile with g++ -O3
>Fix:
(sort of) I can get rid of the calls by commenting out
  ~allocator() __STL_NOTHROW {}
in the standard header stl_alloc.h. So I considered submitting
this as a library bug (and the library probably ought to be
changed)... but the compiler really ought to be able to figure
this out. It's not the __STL_NOTHROW, either, leaving it as
   ~allocator() {}
also causes the pessimizing behavior.



>Release-Note:
>Audit-Trail:
>Unformatted:

Re: c++/6052: calls to allocator::~allocator made for empty class

[bangerth]

Synopsis: calls to allocator::~allocator made for empty class

State-Changed-From-To: feedback->closed
State-Changed-By: bangerth
State-Changed-When: Thu Jan 23 15:49:12 2003
State-Changed-Why:
    Fixed according to submitter. 
    
    Thanks for your feedback. If you find that the complex case
    still doesn't work, then please open a new report.
    
    Thanks
      Wolfgang

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6052

Re: c++/6052: calls to allocator::~allocator made for empty class

[George A. Heintzelman]

The following reply was made to PR c++/6052; it has been noted by GNATS.

From: "George A. Heintzelman" <georgeh@aya.yale.edu>
To: bangerth@dealii.org, gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org,
   nobody@gcc.gnu.org, gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: c++/6052: calls to allocator::~allocator made for empty 
 class
Date: Thu, 23 Jan 2003 10:36:15 -0500

 > Synopsis: calls to allocator::~allocator made for empty class
 > 
 > State-Changed-From-To: analyzed->feedback
 > State-Changed-By: bangerth
 > State-Changed-When: Wed Jan 22 21:22:50 2003
 > State-Changed-Why:
 >     George,
 >     Jason reported that this may be fixed for 3.2 and 3.2.1.
 >     Can you verify this?
 >     
 >     Thanks
 >       Wolfgang
 > http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6052
 
 With g++ 3.2, it appears to be fixed in the simple case I submitted in 
 the bug report. I haven't looked again at the more complicated 
 real-life profiling that I had been doing that prompted the report in 
 the first place.
 
 George Heintzelman
 georgeh@aya.yale.edu
 
 

Re: c++/6052: calls to allocator::~allocator made for empty class

[bangerth]

Synopsis: calls to allocator::~allocator made for empty class

State-Changed-From-To: analyzed->feedback
State-Changed-By: bangerth
State-Changed-When: Wed Jan 22 21:22:50 2003
State-Changed-Why:
    George,
    Jason reported that this may be fixed for 3.2 and 3.2.1.
    Can you verify this?
    
    Thanks
      Wolfgang

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6052

Re: c++/6052: calls to allocator::~allocator made for empty class

[jason]

Synopsis: calls to allocator::~allocator made for empty class

State-Changed-From-To: open->analyzed
State-Changed-By: jason
State-Changed-When: Sun Apr  7 09:33:48 2002
State-Changed-Why:
    This seems to be fixed in the 3.1 branch.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6052