l i n u x - u s e r s - g r o u p - o f - d a v i s
Next Meeting:
July 7: Social gathering
Next Installfest:
Latest News:
Jun. 14: June LUGOD meeting cancelled
Page last updated:
2007 Jan 19 18:43

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
[vox-tech] Nifty macro expansion bug
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[vox-tech] Nifty macro expansion bug

So at work, a coworker noticed an issue with the following code:

  for (i = 0; i < n; i++)

which went away when he wrapped it in braces:

  for (i = 0; i < n; i++)

Figured maybe it was a weird compiler bug.  Being author of the myFREE()
code -- which happens to be a macro -- I realized immediately what I did
wrong.  (And continue to be annoyed with C syntax ;) )

See, myFREE() is actually a macro that looks like this:

  #define myFREE(x) if ((x) != NULL) FREE(x); x = NULL;

Two statements... hence the need for {} around the call to the macro.
(Or, more sensibly, including {}s around what the macro expands to.)

That was a neat catch. :)

vox-tech mailing list

LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
O'Reilly and Associates
For numerous book donations.