[Bug c++/46732] New: Valgrind emits false(?) alarms on boost::make_shared

[dgsteffen at numerica dot us]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46732

           Summary: Valgrind emits false(?) alarms on boost::make_shared
           Product: gcc
           Version: 4.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: dgstef...@numerica.us


Compiling the following code with 4.4.4 and running it under Valgrind produces
what look like (and I hope are) false alarms.  After some discussion with the
Boost people, the conclusion is that it's a compiler bug.

Here's the code (preprocessed code attached as well)

#include <iostream>
#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>

using std::cout;
using std::endl;
using boost::make_shared;
namespace Numerica {
class StateSpace
{
public:
    enum SpaceType {
        Unknown = 0,
        ECI,
        ECEF,
        Topo
    };
    StateSpace(SpaceType spaceType)
        {
            if (spaceType == Topo)
                cout <<  "origin required for topocentric system" << endl;
        }
};

class State
{
public:
    State()
        : m_rep(make_shared<StateRep>(StateSpace::Unknown) )
        {}
protected:
    struct StateRep
    {
        StateRep(StateSpace theStateSpace)
            :
              stateSpace(theStateSpace)
            { }
        StateSpace stateSpace;

    };
    typedef boost::shared_ptr<StateRep> StateRepPtr;
    StateRepPtr m_rep;
};

} // end of namespace Numerica
using namespace Numerica;
using namespace std;
int main()
{
    State state;
}

Here is the Valgrind output:

==478== Memcheck, a memory error detector
==478== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==478== Using Valgrind-3.6.0.SVN-Debian and LibVEX; rerun with -h for copyright
info
==478== Command: testStateSpace
==478== 
==478== Conditional jump or move depends on uninitialised value(s)
==478==    at 0x401749:
Numerica::StateSpace::StateSpace(Numerica::StateSpace::SpaceType)
(testDaveCase.cpp:26)
==478==    by 0x40186F: boost::shared_ptr<Numerica::State::StateRep>
boost::make_shared<Numerica::State::StateRep, Numerica::StateSpace::SpaceType,
>(Numerica::StateSpace::SpaceType&&, ) (make_shared.hpp:150)
==478==    by 0x4017AD: Numerica::State::State() (testDaveCase.cpp:39)
==478==    by 0x401407: main (testDaveCase.cpp:78)
==478== 
==478== 
==478== HEAP SUMMARY:
==478==     in use at exit: 464 bytes in 5 blocks
==478==   total heap usage: 1,080 allocs, 1,076 frees, 85,240 bytes allocated
==478== 
==478== LEAK SUMMARY:
==478==    definitely lost: 0 bytes in 0 blocks
==478==    indirectly lost: 0 bytes in 0 blocks
==478==      possibly lost: 0 bytes in 0 blocks
==478==    still reachable: 464 bytes in 5 blocks
==478==         suppressed: 0 bytes in 0 blocks
==478== Reachable blocks (those to which a pointer was found) are not shown.
==478== To see them, rerun with: --leak-check=full --show-reachable=yes
==478== 
==478== For counts of detected and suppressed errors, rerun with: -v
==478== Use --track-origins=yes to see where uninitialised values come from
==478== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 5 from 5)

Here's the compile command
/usr/local/compilers/4.4.4/bin/c++ -o dynamics/state/Test/testStateSpace.o -c
-isystem/usr/local/Boost/1.44 -isystem/usr/include/python2.6
-isystem/home/dgsteffen/local/kml/include -ansi -Wall -Wextra -pedantic
-Wno-long-long -Wmissing-include-dirs -fshow-column -pthread -g
-fdiagnostics-show-option -std=c++0x -Woverloaded-virtual -Wno-write-strings
-DBOOST_TEST_DYN_LINK -I. dynamics/state/Test/testStateSpace.cpp
/usr/local/compilers/4.4.4/bin/c++ -o dynamics/state/Test/testStateSpace
-Wl,-rpath=/home/dgsteffen/Local/MFATS/testcase/lib
-Wl,-rpath=/usr/local/Boost/1.44/lib/4.4
-Wl,-rpath=/home/dgsteffen/local/kml/lib
-Wl,-rpath=/usr/local/compilers/4.4.4/lib64 -pthread
dynamics/state/Test/testStateSpace.o -Llib -L/usr/local/Boost/1.44/lib/4.4
-L/usr/lib64/python2.6/config -L/home/dgsteffen/local/kml/lib
-lboost_unit_test_framework -lnumerica_dynamics -lnumerica_math -llapack -lblas
-lnumerica_util -lboost_signals -lboost_filesystem -lboost_iostreams
-lboost_thread -lboost_system
scons: done building targets.

Compiler info:
/usr/local/compilers/4.4.4/bin/c++ -v
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: /home/seroberts/gcc-4.4.4/configure
--prefix=/usr/local/compilers/.gcc-4.4.4 --enable-languages=c,c++
--enable-threads=posix --with-system-zlib --enable-__cxa_atexit --enable-shared
--enable-checking=release --disable-multilib --enable-clocale=gnu
--with-mpfr=/usr/local/compilers/mpfr/3.0.0
--with-gmp=/usr/local/compilers/gmp/4.3.2
Thread model: posix
gcc version 4.4.4 (GCC)