Question

Suppose that I have used a free() function to free a memory that,for many reasons, I’m not allowed to.
How can I stop my C application from crashing and just generate an error and continue the execution? I don’t have try-catch kind of provision here (like C++/java…). Is there any way to ignore this error and continue execution?

If yes,

1. How do you do that?
2. More importantly, is it advisable to do so (continuing execution considering this memory error occurred)?

Thank you

Answer 1

There is nothing in the C standard that you can use to do what you want. The description of the free function is very clear on that (§7.20.3.2 in C99):

The free function causes the space pointed to by ptr to be deallocated, that is, made
available for further allocation. If ptr is a null pointer, no action occurs. Otherwise, if
the argument does not match a pointer earlier returned by the calloc, malloc, or
realloc function, or if the space has been deallocated by a call to free or realloc,
the behavior is undefined.