Re: Bug in tracing in DBD::Oracle

[Charles Jardine]

On 27/01/10 17:38, Martin Evans wrote:

Charles Jardine wrote:

On 27/01/10 15:52, Martin Evans wrote:

Hi,

I was asked to enable ora_verbose and send a trace a few days ago.

I'm getting a segfault with DBD::Oracle when ora_verbose or dbd_verbose
is set to 15 in the connect method call. The stack trace is:

[snip]

and that refers to the following line in dbdimp.c:

OCINlsEnvironmentVariableGet_log_stat( &ncharsetid,(size_t)  0,
OCI_NLS_NCHARSET_ID, 0, &rsize ,status );

Oracle defines the second argument as size_t so I guess that cast of 0
to size_t is ok but ocitrace.h then goes on to cast it again to
(unsigned long long) and the format argument has been changed to %llu.
Although these match it segfaults.

I am responsible for this change. It was part of a campaign to avoid
warnings
when compiling on 64-bit gcc platforms. All that is necessary to avoid
the compiler warnings is that the format arguments match the casts
(subject to integral promotion).

I used (unsigned long long) in this case for maximum portability. I
couldn't
find any standard that said that (size_t) might not be wider than
(unsigned long).

If my change breaks PerlIO_vprintf, we must back off. Using (unsigned long)
and %lu would work on all platforms I use. Using (unsigned int) and %u,
would work in this case, but not for all uses of size_t.

This is the only place where I used a %llu or %lld, so there is only
one place to change.

Martin, can you try changing the casts to (unsigned long) and the formats
to %lu, and see if this fixes your problem.

That is what I did in effect (nearly).

I took the casts of 0 to size_t out of the 2 calls in dbdimp.c and added
a cast to size_t on the real call to oracle in the macro. Then I change
the format in the PerlIO_printf to %lu and change the cast to (unsigned
long). This works for me and I guess it will work without warning for
you too.

This isn't exactly what John has in subversion at the moment.

John seems to have corrected my over-zealous cast, and produced
a version which complies without warning and works on both 32-
and 64-bit platforms. Thank you John.

I prefer his version, with the cast to site_t left where it was,
rather than imported into the macro.

If the current SVN version works for Martin, I suggest that no
more needs to be done.

I an sorry to have caused this bother.

--
Charles Jardine - Computing Service, University of Cambridge
c...@cam.ac.uk    Tel: +44 1223 334506, Fax: +44 1223 334679