Re: [COMMITTERS] pgsql: Add comments about why errno is set to zero.

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org>
Subject: Re: [COMMITTERS] pgsql: Add comments about why errno is set to zero.
Date: 2005-12-01 21:00:15
Message-ID: 200512012100.jB1L0FS26208@candle.pha.pa.us
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Tom Lane wrote:
> momjian(at)postgresql(dot)org (Bruce Momjian) writes:
> > Log Message:
> > -----------
> > Add comments about why errno is set to zero.
>
> These comments seem a bit wrongheaded, since "checking
> LONG_MIN/LONG_MAX" is exactly not what we could do to detect an overflow
> error.

Yea, I noticed the 0 was listed as another value that needs to be
checked. Should I just change them all to:

errno = 0; /* avoid checking result for failure */

or should I add a macro to c.h as:

/* Sometimes we need to clear errno so we can check errno
* without having to check for a failure value from the function
* call.
*/
#define CLEAR_ERRNO \\
do { \
errno = 0; \\
while (0);

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
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