cups: parse cups-config output to reduce flags spew

cups: parse cups-config output to reduce flags spew

On both Lucid and Natty, cups-config --libs includes cflags and other
unneeded output.  Parse the cups-config output to emit only the relevant
subsets of flags.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=96635

[Evan Martin, 2011-08-12 17:46:31]

I was surprised to discover this worked without any gyp changes; apparently, the
cups cflags and ldflags aren't actually needed to build?  I did verify the
resulting link line no longer has these extra flags.  Please let me know if
there's some better way to verify this change.

[Lei Zhang, 2011-08-12 18:32:06]

On my machine --cflags returns nothing and --libs returns only "-l" flags. What
are you seeing?

Also, is this wrapper something we'd want to use for all foo-config calls?

[Evan Martin, 2011-08-12 18:37:07]

On 2011/08/12 18:32:06, Lei Zhang wrote:
> On my machine --cflags returns nothing and --libs returns only "-l" flags.
What
> are you seeing?

That's what I see on Lucid.

On Natty (first two empty lines indicate no output):
 for i in cflags ldflags libs; do echo -n "$i: "; cups-config --$i; done
cflags: 
ldflags: 
libs: -lcups -L/usr/lib/x86_64-linux-gnu -g -O2 -g -O2 -I/usr/include/dbus-1.0
-I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -DDBUS_API_SUBJECT_TO_CHANGE
-Wl,-Bsymbolic-functions -lgssapi_krb5 -lkrb5 -lk5crypto -lcom_err
-L/usr/lib/x86_64-linux-gnu -lgnutls -L/lib/x86_64-linux-gnu -lgcrypt -lz -lm
-lcrypt

> Also, is this wrapper something we'd want to use for all foo-config calls?

I don't think so.  It seems specifically cups is broken.
I wonder if I could simplify my code to just examine the --libs output of cups. 
:\

[Lei Zhang, 2011-08-12 19:40:59]

On 2011/08/12 18:37:07, Evan Martin wrote:
> On 2011/08/12 18:32:06, Lei Zhang wrote:
> > On my machine --cflags returns nothing and --libs returns only "-l" flags.
> What
> > are you seeing?
> 
> That's what I see on Lucid.
> 
> On Natty (first two empty lines indicate no output):
>  for i in cflags ldflags libs; do echo -n "$i: "; cups-config --$i; done
> cflags: 
> ldflags: 
> libs: -lcups -L/usr/lib/x86_64-linux-gnu -g -O2 -g -O2 -I/usr/include/dbus-1.0
> -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -DDBUS_API_SUBJECT_TO_CHANGE
> -Wl,-Bsymbolic-functions -lgssapi_krb5 -lkrb5 -lk5crypto -lcom_err
> -L/usr/lib/x86_64-linux-gnu -lgnutls -L/lib/x86_64-linux-gnu -lgcrypt -lz -lm
> -lcrypt
> 
> > Also, is this wrapper something we'd want to use for all foo-config calls?
> 
> I don't think so.  It seems specifically cups is broken.
> I wonder if I could simplify my code to just examine the --libs output of
cups. 
> :\

My natty box has the same sane output as my lucid box. Is your natty box badly
configured in some way?

I feel like we should either not bother with this if it's just your machien, or
if we are going to sanitize foo-config output, then do it for all of them.

[Evan Martin, 2011-08-12 19:45:36]

On Fri, Aug 12, 2011 at 12:40 PM,  <thestig@chromium.org> wrote:
> My natty box has the same sane output as my lucid box. Is your natty box
> badly
> configured in some way?

$ dpkg -s libcups2-dev | grep Version
Version: 1.4.6-5ubuntu1.3

That seems like the current one:
http://packages.ubuntu.com/search?keywords=libcups2-dev

[Lei Zhang, 2011-08-12 20:11:22]

Doh, I think tested on the wrong machine. I see it on my natty box. If you look
in /usr/bin/cups-config, the LIBS= value is clearly incorrect. 

We should file a bug upstream with Ubuntu. It looks like someone complained
about a similar bug in Gutsy a while ago.
https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/163704

[Evan Martin, 2011-08-12 20:14:31]

On Fri, Aug 12, 2011 at 1:11 PM,  <thestig@chromium.org> wrote:
> Doh, I think tested on the wrong machine. I see it on my natty box. If you
> look
> in /usr/bin/cups-config, the LIBS= value is clearly incorrect.
>
> We should file a bug upstream with Ubuntu. It looks like someone complained
> about a similar bug in Gutsy a while ago.
> https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/163704

I updated that bug with this info.  I'll wait a bit, but I don't have
a lot of confidence the fix will be backported...

[Lei Zhang, 2011-08-12 20:19:45]

Ok, since it's a systematic problem for cups-config, LGTM.

Let's mention the bug # in cups_config_helper.py.

[fta, 2011-08-13 10:31:24]

looks this broke oneiric (with cups 1.5.0) :(

https://launchpadlibrarian.net/77154008/buildlog_ubuntu-oneiric-i386.chromium...

[fta, 2011-08-13 15:43:27]

On 2011/08/13 10:31:24, fta wrote:
> looks this broke oneiric (with cups 1.5.0) :(

I filed http://code.google.com/p/chromium/issues/detail?id=92772