dllwrap fails to find last exported symbol alphabetically

dllwrap fails to find last exported symbol alphabetically

[Peter Stephenson]

A problem now seen by two of us with recent Cygwin installations:
mine was updated to `current' status last week.  However, I don't think
this is new since I've been seeing it on my own setup for a while.

Zsh uses `dllwrap --export-all-symbols' to link against it's own DLL's.
On the systems in question, dllwrap failed to identify the last symbol
exported from the main dll (zsh.dll) against which all the other DLL's
are linked.  The symbol in question is `zwarnnam'; we've verified it
really is the last symbol by adding a dummy one later in the alphabet,
and the problem goes away.  (This is an easy workaround so consequently
finding a real fix isn't a high priority for us.)

It sounds like if this is fundamental lots of people would have fallen
over it, but I've no idea what else might be relevant.

Anyway, on systems where it does trigger, it will show up by downloading
zsh 4.2.0 from ftp://ftp.zsh.org/pub/ and trying to compile with default
options.  You will see warnings about failures to find the symbol
zwarnnam when linking DLL's.  (The failure seen by users is a crash on
an attempt to print warning messages form libraries.  Running `vared
nonexistentvar' form the installed shell will do this.)  We haven't
narrowed it down any further.

If you (the Cygwin people) need more information, it's probably best to
prod zsh@sunsite.org (this list runs qconfirm but you only need to
confirm once).

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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Re: dllwrap fails to find last exported symbol alphabetically

[Peter A. Castro]

On Thu, 25 Mar 2004, Peter Stephenson wrote:

> A problem now seen by two of us with recent Cygwin installations:
> mine was updated to `current' status last week.  However, I don't think
> this is new since I've been seeing it on my own setup for a while.
>
> Zsh uses `dllwrap --export-all-symbols' to link against it's own DLL's.

This should be corrected.  I'd changed the Cygwin port to use
'gcc -shared -Wl,--export-all-symbols'
specifically to address export symbol and other loader related issues
under Cygwin.  Apparently my changes never made it back into the source.
I'll have to see why.

> On the systems in question, dllwrap failed to identify the last symbol
> exported from the main dll (zsh.dll) against which all the other DLL's
> are linked.  The symbol in question is `zwarnnam'; we've verified it
> really is the last symbol by adding a dummy one later in the alphabet,
> and the problem goes away.  (This is an easy workaround so consequently
> finding a real fix isn't a high priority for us.)
>
> It sounds like if this is fundamental lots of people would have fallen
> over it, but I've no idea what else might be relevant.

Don't know.  I've only recently pulled it and started my porting.  I'll
figure out what's happening and feed back.

> Anyway, on systems where it does trigger, it will show up by downloading
> zsh 4.2.0 from ftp://ftp.zsh.org/pub/ and trying to compile with default

4.2.0 has only been out for a few days.  Gimme a little time!

I'll get to the bottom of this.

> options.  You will see warnings about failures to find the symbol
> zwarnnam when linking DLL's.  (The failure seen by users is a crash on
> an attempt to print warning messages form libraries.  Running `vared
> nonexistentvar' form the installed shell will do this.)  We haven't
> narrowed it down any further.
>
> If you (the Cygwin people) need more information, it's probably best to
> prod zsh@sunsite.org (this list runs qconfirm but you only need to
> confirm once).

-- 
Peter A. Castro <doctor@fruitbat.org> or <Peter.Castro@oracle.com>
	"Cats are just autistic Dogs" -- Dr. Tony Attwood