On 7/26/24 12:46, Solar Designer wrote:
Unfortunately, *asprintf() are not that easy to use safely:
"For asprintf(), if memory allocation was not possible, or if some other
error occurs, the function shall return a negative value, and the
contents of the location referenced by ptr are undefined, but shall not
refer to allocated memory."
[...]
As I recall, on *BSD's *asprintf() also reset the pointer to NULL. On
upstream glibc, it does not. We failed to get this change past Ulrich
back then:
https://sourceware.org/legacy-ml/libc-alpha/2001-12/msg00045.html
Yes, this came up in the discussion to add asprintf() to POSIX in
https://austingroupbugs.net/view.php?id=1496 :
Of the above listed implementations, all but GNU libc document that they will
set *ptr to NULL on error, while GNU libc explicitly states that you cannot
rely on it to do so (and looking at its code, sometimes it does, sometimes
it doesn't).
and so the standard was written to allow both ways to be conformant.
If GNU libc was willing to change that, perhaps the next version of the
standard could as well.
--
-Alan Coopersmith- alan.coopersm...@oracle.com
Oracle Solaris Engineering - https://blogs.oracle.com/solaris
