In message <[EMAIL PROTECTED]> "Jacques A. Vidrine" writes:
: Ever notice that you tend to send more email when you should be studying
: for a final?
That's why Style(9) wars break out this time of year. :-)
: /* Case 1 */ /* Case 2 */
: if (data) vs. free(data)
: free(data);
:
: I don't see that Case 1 obfuscates anything. In some cases I find it
: clearer: Case 1 implies that maybe no memory was allocated. Case 2
: seems to imply that memory was indeed allocated.
Depends on the reader. case 2 to me says "free the memory, if there's
any to free". This encapsulates case 1 better than having it be
explicit.
: I happy with the opinions I've received. Based on them, I seem to be in
: the minority of preferring `if (data) free(data);' in some cases. OTOH,
: our code base speaks differently than the email I've received -- `if
: (data) free(data);' seems to be used quite alot. I will probably
: continue to use it the way I have before -- to make it clear that there
: may or may not be memory to free at this point.
The if (data) free(data); is the dusty deck problem, also known as the
dead hand of the past problem. Back before ANSI-C (in the mid
1980's), some frees would core dump on free(NULL), while others would
accept it. ANSI-C dictated that it should be accepted and nothing
should happen. All code wasn't changed over night. This is the same
reason that we have the uglification of __P() in our tree too.
Compilers were slow to adpot ANSI-C (no called iso-c or c89) so
allowances needed to be made for the multiple environments the code
would work in. Now that K&R is totally dead, except maybe on Bruce's
machines, the need for it no longer exists.
Warner
To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-hackers" in the body of the message
