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Date: Fri, 9 Jul 2004 11:24:04 +0200 (W. Europe Daylight Time)
From: Daniel Lungu <lungu AT nagra DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: negative error status: gcc vs. cl
In-Reply-To: <Pine.WNT.4.21.0407081839590.215-100000@pc0197.hq.k.grp>
Message-ID: <Pine.WNT.4.21.0407091045180.215-100000@pc0197.hq.k.grp>
X-X-Sender: lungu AT castor DOT hq DOT k DOT grp
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> -----wrong-nil(!)-exit-status-----
> % nerr-cl.exe; echo $?
> 0
> 
> $? cannot distinguish exit(0) from exit(-2) ... this is 
> logical anarchy!

:)   Ah, but those aren't just two different values passed to exit, they are
:) in fact two entirely different versions of the exit function: gcc links in
:) the version from newlib, whereas msvc links in the version from msvcrt.

What I meant was calling same msvcrt exit() with status = {0,-2} (in
nerr-cl.exe).

:)   So the problem really is that the Windoze version of the exit function
:) isn't POSIX compliant.  Still, we already knew that windoze != unix.  
:) That's why cygwin exists, after all!

Right. Still, Cygwin could do better. See below.

:)   Name one platform that *can* reliably test the exit status of binaries
:) that were written for a different platform?  It's an achievement that it
:) can even run them.

Cygwin? When exit status is positive.

If one wrote:

% cat perr.c
int main()
{
    exit (2);
}

she would get:

-----unsigned-8b-exit-status-----
% perr-cl.exe; echo $?
2

Isn't anybody finding weird that "positive exit status works fine from gcc and
cl" i.e. $? can always (gcc or cl) distinguish exit(0) from exit(2)? What I
meant with "reliably".

Isn't the same int exit status being set from mscvrt to 0xfffffffe (nerr-cl.exe)
and 0x00000002 (perr-cl.exe)?

Where does $? = 2 come from?

> ksh :) yields the same Cygwin bug.
:) Don't blame me!

Never meant to. Cheers, daniel.


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