Fwd: Re: zsh compilation problem with autoconf git

Fwd: Re: zsh compilation problem with autoconf git

[Ismail Dönmez]

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Hi Ralf,

I am forwarding your message to zsh-workers list. To summarise the issue zsh 
modules are not compiled with upcoming autoconf 2.62 and Ralf successfully 
identified that zsh/Src/mkmakemod.sh does some unportable stuff :

    # check 2.13, 2.50, and 2.60 syntaxes
    if grep '%@D@%D%' config.status >/dev/null ||
       grep ',@D@,D,' config.status >/dev/null ||
       grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
        is_dynamic=true
    else
        is_dynamic=false
    fi

So the question is, is this thing needed at all, if yes why?

-- 
Never learn by your mistakes, if you do you may never dare to try again.

[-- Attachment #2: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>: Re: zsh compilation problem with autoconf git --]
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From: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
To: "Ismail Dönmez" <ismail@pardus.org.tr>
Cc: bug-autoconf@gnu.org
Subject: Re: zsh compilation problem with autoconf git
Date: Tue, 29 Jan 2008 22:58:41 +0100
Message-ID: <20080129215840.GA11536@ins.uni-bonn.de>

* Ismail Dönmez wrote on Tue, Jan 29, 2008 at 09:38:33PM CET:
> 
> Sure, just grab zsh.git and create two copies of it, and do
[...]
> now if you compare zsh & zsh2 you will see that zsh directory have bunch of 
> shared objects in Src/Modules where as zsh2 have none.

Confirmed.  But with Autoconf 2.59 vs mainline, not 2.61a.
zsh/Src/mkmakemod.sh does ugly and nonsupported things such as
grepping config.status for values:

    # check 2.13, 2.50, and 2.60 syntaxes
    if grep '%@D@%D%' config.status >/dev/null ||
       grep ',@D@,D,' config.status >/dev/null ||
       grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
        is_dynamic=true
    else
        is_dynamic=false
    fi

That looks dubious, and should be fixed.  Further, I don't know why it
should be needed.  When config.status' documented interfaces are used,
there is no need to grep it.  grepping it is explicitly not supported.
Autoconf 2.62's config.status will internally work differently again as
2.61a (more efficiently), and we won't hesitate to change it in again in
every future version if changes help do things better in some way.

If zsh authors can explain why the above should be needed, we may be
able to see whether there is (or was) a bug in Autoconf to be worked
around, and then we can add that to the Autoconf test suite to ensure
that we don't regress.

I can get things to work fine with a hack as below.

Cheers,
Ralf


diff --git a/Src/mkmakemod.sh b/Src/mkmakemod.sh
index d275038..8e9cee5 100644
--- a/Src/mkmakemod.sh
+++ b/Src/mkmakemod.sh
@@ -114,7 +114,8 @@ if $first_stage; then
     # check 2.13, 2.50, and 2.60 syntaxes
     if grep '%@D@%D%' config.status >/dev/null ||
        grep ',@D@,D,' config.status >/dev/null ||
-       grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
+       grep ',@D@,|#_!!_#|D,' config.status >/dev/null ||
+       :; then
 	is_dynamic=true
     else
 	is_dynamic=false

Re: Fwd: Re: zsh compilation problem with autoconf git

[Clint Adams]

On Wed, Jan 30, 2008 at 12:03:33AM +0200, Ismail Dönmez wrote:
> Hi Ralf,
> 
> I am forwarding your message to zsh-workers list. To summarise the issue zsh 
> modules are not compiled with upcoming autoconf 2.62 and Ralf successfully 
> identified that zsh/Src/mkmakemod.sh does some unportable stuff :
> 
>     # check 2.13, 2.50, and 2.60 syntaxes
>     if grep '%@D@%D%' config.status >/dev/null ||
>        grep ',@D@,D,' config.status >/dev/null ||
>        grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
>         is_dynamic=true
>     else
>         is_dynamic=false
>     fi
> 
> So the question is, is this thing needed at all, if yes why?

Presumably Src/mkmakemod.sh would need to be generated to check that
value in any supported manner.  I don't recall a reason that that
can't be done.

Re: Fwd: Re: zsh compilation problem with autoconf git

[Ismail Dönmez]

[ Removed bug-autoconf from CC because this might be off topic for them ]

Wednesday 30 January 2008 00:38:19 tarihinde Clint Adams şunları yazmıştı:
> On Wed, Jan 30, 2008 at 12:03:33AM +0200, Ismail Dönmez wrote:
> > Hi Ralf,
> >
> > I am forwarding your message to zsh-workers list. To summarise the issue
> > zsh modules are not compiled with upcoming autoconf 2.62 and Ralf
> > successfully identified that zsh/Src/mkmakemod.sh does some unportable
> > stuff :
> >
> >     # check 2.13, 2.50, and 2.60 syntaxes
> >     if grep '%@D@%D%' config.status >/dev/null ||
> >        grep ',@D@,D,' config.status >/dev/null ||
> >        grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
> >         is_dynamic=true
> >     else
> >         is_dynamic=false
> >     fi
> >
> > So the question is, is this thing needed at all, if yes why?
>
> Presumably Src/mkmakemod.sh would need to be generated to check that
> value in any supported manner.  I don't recall a reason that that
> can't be done.

Why doesn't it parse config.h instead? I got 

#define DYNAMIC 1

in config.h so this could be grepped easily.

Regards,
ismail

-- 
Never learn by your mistakes, if you do you may never dare to try again.

Re: Fwd: Re: zsh compilation problem with autoconf git

[Ralf Wildenhues]

* Ismail Dönmez wrote on Wed, Jan 30, 2008 at 05:42:40AM CET:
> Wednesday 30 January 2008 00:38:19 tarihinde Clint Adams şunları yazmıştı:
> > On Wed, Jan 30, 2008 at 12:03:33AM +0200, Ismail Dönmez wrote:
> > >
> > >     # check 2.13, 2.50, and 2.60 syntaxes
> > >     if grep '%@D@%D%' config.status >/dev/null ||
> > >        grep ',@D@,D,' config.status >/dev/null ||
> > >        grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
> > >         is_dynamic=true
> > >     else
> > >         is_dynamic=false
> > >     fi
> > >
> > > So the question is, is this thing needed at all, if yes why?
> >
> > Presumably Src/mkmakemod.sh would need to be generated to check that
> > value in any supported manner.  I don't recall a reason that that
> > can't be done.
> 
> Why doesn't it parse config.h instead? I got 

Clint is right.  The clean solution would be to have Src/mkmakemod.sh.in
(or a small helper file it sources) with
  D=@D@
  if test $D = D; then is_dynamic=true; else is_dynamic=false; fi

and of course in configure.ac you'd need
  AC_CONFIG_FILES([Src/mkmakemod.sh]).

Cheers,
Ralf

Re: Fwd: Re: zsh compilation problem with autoconf git

[Peter Stephenson]

Ismail =?utf-8?q?D=C3=B6nmez?= wrote:
> Why doesn't it parse config.h instead? I got
> 
> #define DYNAMIC 1
> 
> in config.h so this could be grepped easily.

That's a nice easy and effective fix.  If anyone wants to be more
sophisticated they can.

Index: Src/mkmakemod.sh
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/mkmakemod.sh,v
retrieving revision 1.16
diff -u -r1.16 mkmakemod.sh
--- Src/mkmakemod.sh	28 May 2007 22:57:41 -0000	1.16
+++ Src/mkmakemod.sh	30 Jan 2008 09:42:16 -0000
@@ -111,10 +111,7 @@
     sed -e '/^#/d' -e 's/ .*/ /' -e 's/^name=/ /'`"
     module_list="${bin_mods}${dyn_mods}"
 
-    # check 2.13, 2.50, and 2.60 syntaxes
-    if grep '%@D@%D%' config.status >/dev/null ||
-       grep ',@D@,D,' config.status >/dev/null ||
-       grep ',@D@,|#_!!_#|D,' config.status >/dev/null; then
+    if grep '^#define DYNAMIC ' config.h >/dev/null; then
 	is_dynamic=true
     else
 	is_dynamic=false


-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070

Re: Fwd: Re: zsh compilation problem with autoconf git

[Eric Blake]

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Hash: SHA1

According to Clint Adams on 1/29/2008 3:38 PM:
|> So the question is, is this thing needed at all, if yes why?
|
| Presumably Src/mkmakemod.sh would need to be generated to check that
| value in any supported manner.  I don't recall a reason that that
| can't be done.

The point was: Why not just use documented interfaces (such as AC_SUBST)
and skip the grep altogether?  The underlying interface is intentionally
unstable, and attempts to grep it are bound to fail as new autoconf
releases use new means of achieving the same results.  Your code will be
easier to maintain if you don't have to add a new grep statement for every
new autoconf release.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             ebb9@byu.net
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