GNU bug report logs - #18592
FFI should have portable access to ‘errno’

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Message #34 received at 18592 <at> debbugs.gnu.org (full text, mbox):

From: "guile <at> discard.email" <guile <at> discard.email>
To: 18592 <at> debbugs.gnu.org
Subject: Re: FFI should have portable access to ‘errno’
Date: Sun, 25 Jan 2015 21:59:32 +0100

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I'd like to point out that when calling a function that might set errno in C,
it's usually good practice to set errno to zero immediately before the call,
so as to be sure that any subsequent non-zero errno value was actually
a consequence of the function call:
 
errno = 0; /* clear errno before the function call */
rtnval = my_func(...);
if (errno != 0) {...}
 
This should probably be taken into account if you're extending
the FFI to provide access to errno.

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