[Valgrind-users] C++ exception gives warning when pthread is linked

[Attila <sa...@fr...>]

Hello,

I got warning to the simple code below (exc.cpp) if I link
the pthread library like

gcc exc.cpp -lpthread -lstdc++

(-D_REENTRANT omitted for simplicity). No problem if I don't
link pthread like

gcc exc.cpp -lstdc++

I guess the libraries are linked dinamically because the
executable is only 37K.

#include <iostream>

class Exception
{
public:
    int _type;
    Exception(int i) : _type(i) {}
};
                                                           
                     
int main()
{
    try {
        throw new Exception(5);
    } catch(Exception* e) {
        std::cout << "gotcha! " << e->_type << std::endl;
        delete(e);
    }
    return 0;
}

The warning message follows:

==12826== Memcheck, a.k.a. Valgrind, a memory error detector
for x86-linux.
==12826== Copyright (C) 2002-2003, and GNU GPL'd, by Julian
Seward.
==12826== Using valgrind-20031012, a program supervision
framework for x86-linux.
==12826== Copyright (C) 2000-2003, and GNU GPL'd, by Julian
Seward.
==12826== Command line:
==12826==    ./a.out
==12826== Startup, with flags:
==12826==    --suppressions=/usr/local/lib/valgrind/default.supp
==12826==    --leak-check=yes
==12826==    --num-callers=9
==12826==    --show-reachable=yes
==12826==    --avoid-strlen-errors=yes
==12826==    -v
==12826== Reading syms from /home/avangel/test/exc/a.out
==12826== Reading syms from /lib/ld-2.3.2.so
==12826==    object doesn't have any debug info
==12826== Reading syms from
/usr/local/lib/valgrind/vgskin_memcheck.so
==12826== Reading syms from /usr/local/lib/valgrind/valgrind.so
==12826== Reading syms from
/usr/local/lib/valgrind/libpthread.so
==12826== Reading syms from /usr/lib/libstdc++.so.5.0.3
==12826==    object doesn't have a symbol table
==12826==    object doesn't have any debug info
==12826== Reading syms from /lib/i686/libc-2.3.2.so
==12826==    object doesn't have any debug info
==12826== Reading syms from /lib/i686/libm-2.3.2.so
==12826==    object doesn't have any debug info
==12826== Reading syms from /lib/libgcc_s-3.2.2-20030225.so.1
==12826==    object doesn't have a symbol table
==12826==    object doesn't have any debug info
==12826== Reading suppressions file:
/usr/local/lib/valgrind/default.supp
==12826== Estimated CPU clock rate is 930 MHz
==12826== REPLACING libc(__GI___errno_location) with
libpthread(__errno_location)
==12826== REPLACING libc(__GI___h_errno_location) with
libpthread(__h_errno_location)
==12826== REPLACING libc(__GI___res_state) with
libpthread(__res_state)
==12826==
==12826== TRANSLATE: 0x40326CB0 redirected to 0x40227DC8
gotcha! 5
==12826== TRANSLATE: 0x40402D80 redirected to 0x40227EAC
==12826==
==12826== ERROR SUMMARY: 0 errors from 0 contexts
(suppressed: 0 from 0)
==12826== malloc/free: in use at exit: 208 bytes in 2 blocks.
==12826== malloc/free: 4 allocs, 2 frees, 296 bytes allocated.
==12826==
==12826== searching for pointers to 2 not-freed blocks.
==12826== checked 4634284 bytes.
==12826==
==12826== 8 bytes in 1 blocks are still reachable in loss
record 1 of 2
==12826==    at 0x4002965E: malloc (vg_replace_malloc.c:153)
==12826==    by 0x402E9086: __cxa_get_globals (in
/usr/lib/libstdc++.so.5.0.3)
==12826==    by 0x402E9CFD: __cxa_throw (in
/usr/lib/libstdc++.so.5.0.3)
==12826==    by 0x80490D8: main (in
/home/avangel/test/exc/a.out)
==12826==    by 0x40326A06: __libc_start_main (in
/lib/i686/libc-2.3.2.so)
==12826==    by 0x8048F9C: ??? (start.S:81)
==12826==
==12826== LEAK SUMMARY:
==12826==    definitely lost: 0 bytes in 0 blocks.
==12826==    possibly lost:   0 bytes in 0 blocks.
==12826==    still reachable: 8 bytes in 1 blocks.
==12826==         suppressed: 200 bytes in 1 blocks.
==12826==
--12826--     TT/TC: 0 tc sectors discarded.
--12826--            1380 chainings, 0 unchainings.
--12826-- translate: new     2681 (41872 -> 540299; ratio
129:10)
--12826--            discard 0 (0 -> 0; ratio 0:10).
--12826--  dispatch: 0 jumps (bb entries), of which 7792
(779200%) were unchained.
--12826--            2/3043 major/minor sched events.  2701
tt_fast misses.
--12826-- reg-alloc: 382 t-req-spill, 101433+2445 orig+spill
uis, 13051 total-reg-r.
--12826--    sanity: 3 cheap, 1 expensive checks.
--12826--    ccalls: 11222 C calls, 55% saves+restores
avoided (36958 bytes)
--12826--            15152 args, avg 0.87 setup instrs each
(3696 bytes)
--12826--            0% clear the stack (33666 bytes)
--12826--            3880 retvals, 35% of reg-reg movs
avoided (2680 bytes)

system configuration:
gcc (GCC) 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
glibc 2.3.2
Redhat 8

Thanks in advance,
Attila