howto catch access violation

[AMosmann]

I look for a possibility to catch an access violation like

try
int *p;
*p=1;
catch (CWhatever *e) {
if (e->m_cause==CWhatever::ecAccessViolation){
TRACE("There are big problems, lucky guy"
}
e->Delete();
}

Does anyone have such an Idea?
(-:



Greetings Andreas

 

[palbano]

That does not really reflect the typical usage of exception handling. Exceptions are generally caught by outer level code not inner level code. Then in that case what would you do. However if you want to try I believe structured exception handling can catch those errors but I don’t know how helpful that will be.

Generally when using pointers you always initialize them and always check them.

int* p = NULL;
if( p){
....
}

If you want DEBUG time notification of problems that is what asserstions are for

// C++
assert( p);
// MFC
ASSERT( p);

Also of course minimize the use of pointers by design. This eliminates the majority (99%) of those errors through design rather than error handling.

-pete

 

[AMosmann]

to explain it a bit more

I have to use some modules programmed by other programmers.
To avoid that the complete application crashes without any senseful hint I would like to catch nearly all possible exceptions when starting that modules.

try
BadFunctionThatCouldRaiseAccessViolation();
catch (CWhatever *e) {
if (e->m_cause==CWhatever::ecAccessViolation){
TRACE("There are big problems, lucky guy"
}
e->Delete();
}

;-)


Greetings Andreas

 

[palbano]

As I stated I believe structured exception handling is the only way to catch access violations. However it does not work the way you want. Basically you set a handler function that gets called. So you don’t get to use a try/catch block where you want to catch the exception.

So I guess the short answer is No.

>> I have to use some modules programmed by other programmers.

If you have the source you need to fix it. If you don’t have the source then if you don’t want the application to crash you should not use buggy libraries.


-pete

 

[AMosmann]

thx for your answer, but I dont have to choose between the libraries, the boss is doing that, I "only" have to manage that.
Libraries exist longer than I work in this company, are very complex and not too easy to debug, cause errors only come from time to time.
But, if the error happens in my part - I am the looser
So I try to catch as catch can

Hope dies last


Greetings Andreas

 

[JOLESEN]

catch(...) will catch an access violation - but you won't know what caused the exception.

/JOlesen

 

[AMosmann]

Can you explain it more?
catch(what)?
I tried CException*, but it did not work


Greetings Andreas

 

[JOLESEN]

Try it out :




#include <cstdio>
#include <cstring>

void main(void)
{
char * psrc = &quot;abc&quot;;
try {
strcpy(0, psrc);
}
catch(...) {
printf(&quot;\nGotYah&quot;
}
}

 

[palbano]

Sure, but that's not what he posted. Try this

int* p;
try{
	*p = 10;
}catch(...){
	TRACE("GotYahNot\r\n");
}

-pete

 

[AMosmann]

hi pete
>Sure, but that's not what he posted. Try this

>int* p;
>try{
> *p = 10; //;-)
>}catch(...){
> TRACE(&quot;GotYahNot\r\n&quot;
>}

thx pete and /JOlesen


Greetings Andreas

 

[Cagliostro]

you can use SEH frame:
__try
{
}__except(.......)
{
}

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com