Re: commit ee46f6404b033f4d1312c6b52a207ec2da99d94b

[Ben Pfaff]

John Darrington <address@hidden> writes:

> Regarding Jason's latest commit to master, ("Merged changes from 
> branch interaction-review"): 
>
> I get nervous when I see memcpy used, because :
>
> 1) Its use of void * arguments circumvents type checking.
> 2) It offers no protection against buffer overflow.
>
> The patch below fixes the first problem (you'll have to re-run make -f Smake).

I don't mind using a function that provides more type-checking,
but for that purpose u8_cpy() is a better choice than
u8_strncpy(), since it has less overhead.  It also won't stop at
a null byte, which matches the behavior of most of our current
code.  (It might make sense to change that behavior, but I would
want to do it as a conscious choice all at one time, not
accidentally bit by bit, if possible.)

> Regarding the second problem, (specifically, I can't see anything to ensure
> that result->val will be large enough to contain  the concatenated string)
> I suggest an assertion similar to assert (offset < val_width);

result->val should be large enough because it should have been
created by interaction_variable_create(), which sums up the
widths of the values that are to be concatenated.
-- 
Ben Pfaff 
http://benpfaff.org