Boatload of warnings in CVS HEAD :-(

Tom Lane wrote:

We can fix this for gcc by putting __attribute__((noreturn)) on the
declaration of pg_re_throw(), but what about other compilers?

Sun studio also complains about it :(.

Zdenek

Tome Lane wrote:

We can fix this for gcc by putting __attribute__((noreturn)) on the
declaration of pg_re_throw(), but what about other compilers?

For MSVC 2005 use __declspec(noreturn) (see [1]http://msdn2.microsoft.com/en-us/library/k6ktzx3s(VS.80).aspx). I think this also work for some older versions of MSVC.

Regards,
Hannes Eder

References:
[1]: http://msdn2.microsoft.com/en-us/library/k6ktzx3s(VS.80).aspx

"Hannes Eder" <Hannes@HannesEder.net> writes:

Tome Lane wrote:

We can fix this for gcc by putting __attribute__((noreturn)) on the
declaration of pg_re_throw(), but what about other compilers?

For MSVC 2005 use __declspec(noreturn) (see [1]). I think this also work for some older versions of MSVC.

It might be too messy to try to do this for all compilers. I thought of
a plan B, which is to make PG_RE_THROW() expand as

pg_re_throw(), exit(1)

which should be enough to persuade any compiler that understands the
concept at all. Comments?

regards, tom lane

Zdenek Kotala wrote:

Tom Lane wrote:

We can fix this for gcc by putting __attribute__((noreturn)) on the
declaration of pg_re_throw(), but what about other compilers?

Sun studio also complains about it :(.

I'm sorry it was to late for me, I recheck it again and Sun studio is
happy :-) and does not complaint about it, however there are a lot of
warning messages (not relevant with this issue). Most of them is about
following construct:

switch(..)
{

case x :
return(..);
break;
...

Is the reason for keeping this in a code? Another kind of construct is:

#define PG_RETURN_NULL() \
do { fcinfo->isnull = true; return (Datum) 0; } while (0)

It looks strange for me. Why it is used?

or

for(;;) { ... break;} see e.g
http://doxygen.postgresql.org/postgres_8c-source.html#l00198

or
why is there while ... break instead if?
http://doxygen.postgresql.org/comment_8c-source.html#l00221

thanks for explanation
Zdenek

On Fri, May 04, 2007 at 02:18:31PM +0200, Zdenek Kotala wrote:

Is the reason for keeping this in a code? Another kind of construct is:

#define PG_RETURN_NULL() \
do { fcinfo->isnull = true; return (Datum) 0; } while (0)

This is a standard way of getting multiple statements into a macro. If
the compiler complains, too bad, there isn't a standard alternative.

for(;;) { ... break;} see e.g
http://doxygen.postgresql.org/postgres_8c-source.html#l00198

So that within the loop you can use continue to start it again.

or
why is there while ... break instead if?
http://doxygen.postgresql.org/comment_8c-source.html#l00221

Not sure about this one. It's not wrong, but it is unusual. Maybe
someone wanted to make it so that in the future it would handle
multiple cases?

Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/

Martijn van Oosterhout wrote:

On Fri, May 04, 2007 at 02:18:31PM +0200, Zdenek Kotala wrote:

Is the reason for keeping this in a code? Another kind of construct is:

#define PG_RETURN_NULL() \
do { fcinfo->isnull = true; return (Datum) 0; } while (0)

This is a standard way of getting multiple statements into a macro. If
the compiler complains, too bad, there isn't a standard alternative.

So it is standard by it's not standard ;-)

or
why is there while ... break instead if?
http://doxygen.postgresql.org/comment_8c-source.html#l00221

Not sure about this one. It's not wrong, but it is unusual. Maybe
someone wanted to make it so that in the future it would handle
multiple cases?

There are many other cases where we do it cleanly, without the while
loop. I don't see any reason to not do this one the same way.

- while ((oldtuple = systable_getnext(sd)) != NULL)
+ oldtuple = systable_getnext(sd);
+ if (HeapTupleIsValid(oldtuple))
...
- break;

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.