A C version of TRY / CATCH / FINALLY blocks. Compatible with GNU C89.
With this tool, you will be able to create self made exceptions and catch them to avoid your program to crash.
Provided exceptions are :
- Exception : the generic exception
- AbortException : your program was about to crash abruptly
- FloatingPointException : a division by zero was done
- IllegalInstruction : you tried to modify the memory of the program itself while running (not the stack or the heap)
- SignalInterupted : the program was asked to stop (by an interruption character such as control-C)
- SegmentationFault : the good old segmentation fault was caught
- SignalTermination : the program was asked to stop
Here is a commented example of how to catch an exception :
#include "exsee.h"
#include <stdio.h>
int main(){
void * a; // where you will store the exception
int * b; // used as an example of segmentation fault exception
TRY{
puts("ABORT TEST");
abort(); // here, we raise a AbortException
puts("failed"); // should not be printed
}CATCH(AbortException, a){
puts(WHAT(a)); // WHAT returns the content of an exception
}
TRY{
puts("\nSEGFAULT TEST");
b = (int*)25;
*b = 4; // here, we raise a SegmentationFault
puts("failed"); // should not be printed
}CATCH(SegmentationFault, a){
puts(WHAT(a)); // WHAT returns the content of an exception
}
return 0;
}To explain how to create a self-made exception, we will create one containing an int attribute.
First, we need to create our structure that will inerit from exception_t like below :
typedef struct myexcept{
exception_t except;
int i;
}myexcept_t;With this class, we will now instanciate the except attribute of our class (we do not really instanciate, we rather define how each instance will be instanciated). For that, we will do like below :
// In the .c file
NEW_EXCEPTION_EXSEE(MyExcept, // Name of the exception (name to use with new_exsee, delete_exsee and catch)
"Personnal exception", // WHAT message of the exception
sizeof(myexcept_t), // memory size of the exception (can be set to 0 if it is the same size as exception_t)
ctor_me, // constructor of type void*(*)(void*,va_list) (can be NULL)
NULL); // destructor of type void*(*)(void) (can be NULL)
// In the .h file
NEW_EXCEPTION_EXSEE_H(MyExcept);If we want to instanciate and delete an instance of our newly made exception (well, there is a missing function but it is described later), we can do like that :
void * except = new_exsee(MyExcept, 1); // can be of type myexcept_t *
delete_exsee(except);The last step (that will appeare before in your code) is the implementation of a constructor. It is really simple and can be done just like that :
void * ctor_me(void * e, va_list vl){
((myexcept_t *)e)->i = va_arg(vl, int);
return e;
}