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Thread: undefined reference to _sys_nerr

undefined reference to _sys_nerr

From
Juhan Ernits
Date:
Hello!

System is NT4 SP6, cygwin 1.1, gcc 2.95.2, PG7RC2.
Having fixed the dllmain problem, I got the following one:

The step that assembles postgres.exe fails with the following messages:

utils/SUBSYS.o(text+0x42de7):elog.c: undefined reference to '_sys_nerr'
utils/SUBSYS.o(text+0x437b3):exc.c: undefined reference to '_sys_nerr'
collect2: ld returned 1 exit status
make[1]: *** [postgres] Error 1
...

How should one cope with that?

Thanks,

Juhan Ernits

Re: undefined reference to _sys_nerr

From
Enrique Perez Terron
Date:
I have run into the same sequence of problems as Juhan Ernits,
and I still do not have a solution.

I just tried a few commands that might shed some light on the problem of
undefined sys_nerr:

    bash-2.04$ nm /lib/libc.a | grep errno
    00000000 ? __imp__h_errno
    00000000 T ___errno
    00000000 ? __imp____errno

    bash-2.04$ nm /lib/libc.a | grep sys_nerr
    00000000 ? __imp___sys_nerr

We see that the C library does define errno, but not sys_nerr.

Searching the other libraries I found that sys_nerr and sys_errlist are both
defined
in the libraries /usr/lib/libmsvcrt20.a and /usr/lib/libmsvcrt40.a

I do not know what these libraries are for, or why sys_errlist is not in
libc.a,
does anyone have a hint?

(Oh, could be that msvcrt stands for Microsoft Visual C Runtime?)

If libc does not have sys_errlist, where does strerror() get its data from?
Should we rather rely on strerror to check the validity of the argument,
and output the alternative string only if strerror returns a null pointer
or a pointer to an empty string?

Yours
Enrique Perez-Terron

Juhan Ernits <Juhan@suhkur.cc.ioc.ee> wrote:
>Hello!
>
>System is NT4 SP6, cygwin 1.1, gcc 2.95.2, PG7RC2.
>Having fixed the dllmain problem, I got the following one:
>The step that assembles postgres.exe fails with the following messages:
>
>utils/SUBSYS.o(text+0x42de7):elog.c: undefined reference to '_sys_nerr'
>utils/SUBSYS.o(text+0x437b3):exc.c: undefined reference to '_sys_nerr'
>collect2: ld returned 1 exit status
>make[1]: *** [postgres] Error 1
>...
>
>How should one cope with that?
>Thanks,
>Juhan Ernits

Re: Re: undefined reference to _sys_nerr

From
Peter Eisentraut
Date:
Enrique Perez Terron writes:

> If libc does not have sys_errlist, where does strerror() get its data from?

I think the coding in elog.c and exc.c is kind of pointless (other
locations happily use strerror indiscriminately) and obviously not
portable. It should probably be changed.

> Should we rather rely on strerror to check the validity of the argument,
> and output the alternative string only if strerror returns a null pointer
> or a pointer to an empty string?

strerror should always return some error message, even if the argument
isn't valid. That's its whole point, versus using sys_errlist[errno]
(which is probably not portable either).


> Juhan Ernits <Juhan@suhkur.cc.ioc.ee> wrote:
> >Hello!
> >
> >System is NT4 SP6, cygwin 1.1, gcc 2.95.2, PG7RC2.
> >Having fixed the dllmain problem, I got the following one:
> >The step that assembles postgres.exe fails with the following messages:
> >
> >utils/SUBSYS.o(text+0x42de7):elog.c: undefined reference to '_sys_nerr'
> >utils/SUBSYS.o(text+0x437b3):exc.c: undefined reference to '_sys_nerr'
> >collect2: ld returned 1 exit status
> >make[1]: *** [postgres] Error 1
> >...


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Peter Eisentraut                  Sernanders väg 10:115
peter_e@gmx.net                   75262 Uppsala
http://yi.org/peter-e/            Sweden