lua-users home
lua-l archive

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]

On Tue, Nov 29, 2005 at 10:21:54AM +0100, Klaus Ripke wrote:
> The C language does define a lot of library functions and none
> checks bad pointers.

I wouldn't say "none".  There are a few cases where passing a null
pointer does have defined behavior in the C API.  The most obvious
example is free(NULL), which was originally undefined but considered
useful enough to add it as a safe operation for C89.

Now, if by "bad pointer" you also mean non-null bad pointers, then
indeed there are no checks for that sort of thing.

> but there is no way in C to check for a runaway pointer like a stack
> overflow.

In fact as far as standard C is concerned, the existence of a stack at
all is an implementation detail.  Terms such as "stack" and "heap"
aren't even in the Standard.  They just come from the most common ways
of implementing it.

                                                  -Dave Dodge