From: Jim Meyering <jim@meyering.net>
To: rms@gnu.org
Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org
Subject: Re: emacs' turn: remove useless if-before-free tests
Date: Sun, 01 Jun 2008 16:22:37 +0200 [thread overview]
Message-ID: <87k5h9grpu.fsf@rho.meyering.net> (raw)
In-Reply-To: <E1K2o9F-0007Rw-Dk@fencepost.gnu.org> (Richard M. Stallman's message of "Sun, 01 Jun 2008 10:03:01 -0400")
Richard M Stallman <rms@gnu.org> wrote:
> Given that most Emacs code calls xfree rather than free, there are not
> many of these if statements, and we rarely add any.
> Why remove them?
Why *not* remove them?
I find that removing the inherent duplication is safe (mechanical),
and makes the code more readable and more maintainable. For example,
- if (x_customization_string)
- free (x_customization_string);
+ free (x_customization_string);
- if (fdp->infname != NULL) free (fdp->infname);
- if (fdp->infabsname != NULL) free (fdp->infabsname);
- if (fdp->infabsdir != NULL) free (fdp->infabsdir);
- if (fdp->taggedfname != NULL) free (fdp->taggedfname);
- if (fdp->prop != NULL) free (fdp->prop);
+ free (fdp->infname);
+ free (fdp->infabsname);
+ free (fdp->infabsdir);
+ free (fdp->taggedfname);
+ free (fdp->prop);
Another advantage is that readers won't wonder why the code is performing
what has long been a useless test -- and then re-read to ensure that
the tested expression and the free argument are properly related.
POSIX requires that free(NULL) be a no-op.
The same arguments hold for xfree, once it has been modified to
accept NULL like free does:
- if (font->bounds.rows[i])
- xfree (font->bounds.rows[i]);
+ xfree (font->bounds.rows[i]);
- if (f->output_data.x->saved_menu_event)
- xfree (f->output_data.x->saved_menu_event);
-
+ xfree (f->output_data.x->saved_menu_event);
next prev parent reply other threads:[~2008-06-01 14:22 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-31 16:29 emacs' turn: remove useless if-before-free tests Jim Meyering
2008-06-01 1:25 ` Miles Bader
2008-06-01 11:10 ` Jim Meyering
2008-06-01 13:48 ` Miles Bader
2008-06-01 14:35 ` Jim Meyering
2008-06-01 14:51 ` David Kastrup
2008-06-01 15:57 ` Miles Bader
2008-06-01 14:03 ` Richard M Stallman
2008-06-01 14:22 ` Jim Meyering [this message]
2008-06-02 10:54 ` Richard M Stallman
2008-06-02 11:22 ` Jim Meyering
2008-06-01 21:41 ` Stefan Monnier
2008-06-02 0:56 ` YAMAMOTO Mitsuharu
2008-06-02 2:05 ` Miles Bader
2008-06-02 2:34 ` YAMAMOTO Mitsuharu
2008-06-02 16:30 ` Richard M Stallman
2008-06-02 2:26 ` Stefan Monnier
2008-06-02 6:14 ` Jim Meyering
2008-06-08 10:53 ` Emanuele Giaquinta
2008-06-08 12:31 ` Jim Meyering
2008-06-10 10:25 ` Jim Meyering
2008-06-12 22:54 ` Jim Meyering
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