unhandled exception with a chook

[ksoufi]

I am programming a chook with MSVC++. When I debug the chook, I get an error :

 

"Unhandled exception in Router8.exe Access

Violation"

I'm trying to get a level name using get_levname function from m_io.h.

Any idea what the problem could be?

 

Thanks!

[Bullines]

Have you tested to see if get_levname() is returning TRUE/FALSE?

[ksoufi]

Yes

boolean succ = get_levname(num_level,20,Name_level);

but i can't see the result,the error message pop up!

thanks

[ksoufi]

the main problem, is that the error appears when get_levname function is called, so i don't can test the return value.

Is there any relation with Router or mill?

[Bullines]

Did you try something like?:

 

code:

---

boolean succ = get_levname(num_level,20,Name_level);

 

if (succ == TRUE)

AfxMessageBox("Success");

else

AfxMessageBox("Something went wrong");

---

Just to see if it's ever successful.

[Bullines]

quote:

---

the main problem, is that the error appears when get_levname function

---

Are you certain that you allowed enough room for a '0' in the string name? It could be that the max_size parameter is too small for the level name. For example:

 

code:

---

char szSomeCharArray[7] = "Testing";  // bad

char szSomeCharArray[8] = "Testing"; // good

---

[ksoufi]

I'd tryied many lengths of max_size, the problem isn't there

[bryan314]

Here's a slight modification of Bullines' code. It's not too pretty but compiles and runs fine on my machine. It prints the name level or error to mastercams prompt areas. See if this works any better.

 

Bryan

 

code:

---

boolean succ;

short num_level = 1;

char Name_level[600];

 

succ = get_levname(num_level,599,Name_level);

 

if (succ == TRUE){

cleartextall();

mprintf("Successn");

mprintf("levelname:%sn",Name_level);

wait_for_space();

}

else

{

cleartextall();

mprintf("Something went wrongn");

wait_for_space();

}

 

---

[ksoufi]

Thanks

it runs fine also

you know the oly difference between my code and your's is that i declared "char *Name_level" and u have declared an array!

in m_io.h, they said

 

EXTERN boolean (*_get_levname) (

short lev_num, /* I: level number */

short max_size, /* I: size of string */

char *level_name); /* O: level name (max of 'max_size' characters) */

#define get_levname (*_get_levname)

 

I don't understand why they (mastercam programmers) need to know the size of the level name if the same time they ask for an array!!?

thnk u very much

[Bullines]

quote:

---

I don't understand why they (mastercam programmers) need to know the size of the level name if the same time they ask for an array!!?

thnk u very much

---

Likely for a call to malloc() or memset()

[ksoufi]

No, Sorry itsn't the same thing.

With malloc we need to know the memory space to allocate dynamically, but here when we declare an array (staticaly) we know in advance the space needed!

So the max_size in get_levname function will be unused

[Bullines]

quote:

---

With malloc we need to know the memory space to allocate

---

malloc(), on most platforms, takes only one parameter; the number of bytes to reserve. But this is besides the point

 

quote:

---

No, Sorry itsn't the same thing.

With malloc we need to know the memory space to allocate dynamically, but here when we declare an array (staticaly) we know in advance the space needed!

So the max_size in get_levname function will be unused

---

You missed what I meant I meant that the malloc() or memset() is likely called in Mastercam after a C-Hook developer, such as yourself, passes a var like max_size to a C-Hook function. Mastercam, in turn, probably uses malloc() or memset() internally.

[ProductDevelopmentGuy]

get_levname() is expecting that the programmer has declared the string size himself, i.e.

 

char lName[200];

 

or

 

char *lName = (char *)malloc(200, sizeof(char));

 

before calling the function. We will put the name in the memory that you provide. Passing the 'size' of the string ensures that we don't try to fill beyond the true length of the array

 

PDG

[Bullines]

quote:

---

Passing the 'size' of the string ensures that we don't try to fill beyond the true length of the array

---

No buffer overrun's allowed!

[ksoufi]

Ah.... yeah ...I understand now your remark

But it still an ambiguos method used by mastercam