Обсуждение: 'errno' undefined?

I get the following when building cvs:

gcc -I../../include  -O2 -g -Wall -Wmissing-prototypes
-Wmissing-declarations   -c pqformat.c -o pqformat.o
pqformat.c: In function `pq_endmessage':
pqformat.c:219: `errno' undeclared (first use in this function)
pqformat.c:219: (Each undeclared identifier is reported only once
pqformat.c:219: for each function it appears in.)
make: *** [pqformat.o] Error 1

Any ideas?

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Philip Warner <pjw@rhyme.com.au> writes:
> I get the following when building cvs:

Is that with the be-pqexec removal I just did?  I pulled out a couple
of header inclusions that I thought were no longer necessary --- and
they weren't on my platform.  But maybe something in there was needed
on yours.  Where does errno get declared in your system's headers?
        regards, tom lane

At 00:57 8/07/00 -0400, Tom Lane wrote:
>Philip Warner <pjw@rhyme.com.au> writes:
>> I get the following when building cvs:
>
>Is that with the be-pqexec removal I just did?  I pulled out a couple
>of header inclusions that I thought were no longer necessary --- and
>they weren't on my platform.  But maybe something in there was needed
>on yours.  Where does errno get declared in your system's headers?

errno.h


----------------------------------------------------------------
Philip Warner                    |     __---_____
Albatross Consulting Pty. Ltd.   |----/       -  \
(A.C.N. 008 659 498)             |          /(@)   ______---_
Tel: (+61) 0500 83 82 81         |                 _________  \
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and from pgp5.ai.mit.edu:11371   |/

Philip Warner <pjw@rhyme.com.au> writes:
>> they weren't on my platform.  But maybe something in there was needed
>> on yours.  Where does errno get declared in your system's headers?

> errno.h

Hmm.  The stuff I just removed doesn't look like it would cause an
inclusion of errno.h.  Which other system headers include errno.h
on your box?

The answer probably is that pqformat.h needs to include <errno.h>,
but I'm just curious to understand why it didn't before ...
        regards, tom lane

At 01:17 8/07/00 -0400, Tom Lane wrote:
>Hmm.  The stuff I just removed doesn't look like it would cause an
>inclusion of errno.h.  Which other system headers include errno.h
>on your box?
>
>The answer probably is that pqformat.h needs to include <errno.h>,
>but I'm just curious to understand why it didn't before ...
>

pjw@Cerberus2:~/work/postgresql-cvs/pgsql > grep errno.h /usr/include/*.h
/usr/include/argz.h:#include <errno.h>
/usr/include/envz.h:#include <errno.h>
/usr/include/errno.h: * ISO C Standard: 4.1.3 Errors    <errno.h>
/usr/include/errno.h:#endif /* errno.h  */
/usr/include/errnos.h:# include <linux/errno.h>
/usr/include/pthread.h:#include <errno.h>

pjw@Cerberus2:~/work/postgresql-cvs/pgsql > grep errno.h /usr/include/*/*.h
/usr/include/X11/Xlibint.h:#include <errno.h>
/usr/include/X11/Xos.h:#include <errno.h>
/usr/include/asm/unistd.h:/* user-visible error numbers are in the range -1
- -122: see <asm-i386/errno.h> */
/usr/include/linux/errno.h:#include <asm/errno.h>
/usr/include/linux/isdn.h:#include <linux/errno.h>
/usr/include/linux/mm.h:#include <linux/errno.h>
/usr/include/linux/notifier.h:#include <linux/errno.h>
/usr/include/linux/quota.h:#include <linux/errno.h>
/usr/include/mysql/my_sys.h:#include <errno.h>                  /* errno is
a define */
/usr/include/python1.5/Python.h:#include <errno.h>
/usr/include/rpcsvc/bootparam.h:#include <sys/errno.h>
/usr/include/rpcsvc/bootparam_prot.h:#include <sys/errno.h>
/usr/include/sys/errno.h:#include <errno.h>

no matches in local/include
----------------------------------------------------------------
Philip Warner                    |     __---_____
Albatross Consulting Pty. Ltd.   |----/       -  \
(A.C.N. 008 659 498)             |          /(@)   ______---_
Tel: (+61) 0500 83 82 81         |                 _________  \
Fax: (+61) 0500 83 82 82         |                 ___________ |
Http://www.rhyme.com.au          |                /           \|                                |    --________--
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and from pgp5.ai.mit.edu:11371   |/

>> The answer probably is that pqformat.h needs to include <errno.h>,
>> but I'm just curious to understand why it didn't before ...

Well, I noticed that <stdlib.h> pulls in <errno.h> on my box, so that
explains why I didn't see a problem.  I still don't see the connection
between the includes I killed and <errno.h> on your box, though...
curious.  Anyway I committed the change to pqformat.c.
        regards, tom lane

> Where does errno get declared in your system's headers?

The ANSI C standard says errno is declared in <errno.h>.  Since ANSI C
also says that the standard header files are independent, it is poor
form for your system to have included <errno.h> via <stdlib.h>.

(Yeah, since you've already added <errno.h> this is a bit pedantic.)

Ciao,

Giles