Re: "this" pointer get corrupted after function call

From:

"Krishs P." <krishs.patil@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 27 Jun 2012 01:35:27 -0700 (PDT)

Message-ID:

<da9ba575-6b3d-4fec-93ac-052c81648dd1@googlegroups.com>

On Wednesday, 27 June 2012 13:42:33 UTC+5:30, Ian Collins wrote:

On 06/27/12 07:39 PM, Krishs P. wrote:

On Wednesday, 27 June 2012 12:44:53 UTC+5:30, Alf P. Steinbach wrote:

On 27.06.2012 08:36, Krishs wrote:

Hi all,
well this is pretty much confusion to me as well, but here is
scenario. I have two shared objects file and one loader executable.
loader calls extern function in shared1 , which has one class ,
initialize it and run its method , which would call extern in shared2=

after shared2 extern function returns, the "this" pointer get 0x00=

A::Run(),
any guess what would have been happened, I have using gcc version =

to build the project.

** loader.cpp
       - calls run_test(); in shared1.cpp

** shared1.cpp
         class A {
             public:
                  Run() { mum_tum(); doWell(); }
                  doWell() { }
         };

         extern void run_test() {
                 A *a = new A();
                 a->Run();
         }

** shared2.cpp
        extern void mum_tum() { }

thank you.

with three different method naming conventions in so short a code, plu=

a question of non-reproducable behavior where even the description of
what's allegedly wrong is suspect, this is clearly a troll posting

thx for the reply . but, the code i am working with is pretty much big =

and complex, so I described the scenario with short pseudo code. The main p=
roblem relies when actual this pointer of "class A" get vanished after call=
to extern function in second shared dll. What I am concerned here is if it=
is case of stack corruption or something. I have checked similar case from=
gdb forum but no clue.

Please wrap your lines!

It looks like you problem may be windows rather than C++ related, have
you tried a windows group?

--
Ian Collins

No actually, this is on linux with gcc compiler suite. here is short debugg=
ing session information

(gdb) l
tResult = RunClient(&tParams, &tResults, &m_bStopped, m_szName, m_szInstH=
dl,
gethostbyname);

(gdb) p this
$1 = (CActiveTest * const) 0x80da4a0
(gdb) n
(gdb)
CActiveTest::Run (this=0x0) at ActiveTest.cpp:47
47 if (tResult != TESTERR_OK)
(gdb)
(gdb) p this
$2 = (CActiveTest* const) 0x0
(gdb)