[Buildroot] [PATCH] package/cups: fix static linking with GnuTLS

[Buildroot] [PATCH] package/cups: fix static linking with GnuTLS

[Jörg Krause]

cups forgets to link against the libs found by pkg-config if it is build with
GnuTLS support.

Otherwise, static build fails with:
../cups/libcups.a(tls.o): In function `http_gnutls_create_credential':
cups-2.1.2/cups/tls-gnutls.c:762: undefined reference to `gnutls_x509_crt_init'
[..]

Fixes:
http://autobuild.buildroot.net/results/205/20509b7d1edc73dc2a7622f2ae7dbf9f6665a918/
http://autobuild.buildroot.net/results/b86/b86d685caf8cf812f9505fca2de36fb8c18baee1/

Patch is sent upstream.

Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
---
 .../cups/0004-Fix-static-linking-with-GnuTLS.patch | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 package/cups/0004-Fix-static-linking-with-GnuTLS.patch

diff --git a/package/cups/0004-Fix-static-linking-with-GnuTLS.patch b/package/cups/0004-Fix-static-linking-with-GnuTLS.patch
new file mode 100644
index 0000000..67df4dc
--- /dev/null
+++ b/package/cups/0004-Fix-static-linking-with-GnuTLS.patch
@@ -0,0 +1,39 @@
+From ceaed5f1efe917c70e5ae9161695ba1c559b912d Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?J=C3=B6rg=20Krause?= <joerg.krause@embedded.rocks>
+Date: Sun, 28 Feb 2016 16:35:56 +0100
+Subject: [PATCH] Fix static linking with GnuTLS
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+cups forgets to link against the libs found by pkg-config if it is build with
+GnuTLS support.
+
+Otherwise, static build fails with:
+../cups/libcups.a(tls.o): In function `http_gnutls_create_credential':
+cups-2.1.2/cups/tls-gnutls.c:762: undefined reference to `gnutls_x509_crt_init'
+[..]
+
+Status upstream: Pending
+
+Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
+---
+ Makedefs.in | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Makedefs.in b/Makedefs.in
+index 5d261c3..1d00c73 100644
+--- a/Makedefs.in
++++ b/Makedefs.in
+@@ -143,7 +143,7 @@ IPPFIND_MAN	=	@IPPFIND_MAN@
+ LDFLAGS		=	-L../cgi-bin -L../cups -L../filter -L../ppdc \
+ 			-L../scheduler @LDARCHFLAGS@ \
+ 			@LDFLAGS@ @RELROFLAGS@ @PIEFLAGS@ $(OPTIM)
+-LINKCUPS	=	@LINKCUPS@ $(LIBGSSAPI) $(DNSSDLIBS) $(LIBZ)
++LINKCUPS	=	@LINKCUPS@ $(SSLLIBS) $(LIBGSSAPI) $(DNSSDLIBS) $(LIBZ)
+ LINKCUPSIMAGE	=	@LINKCUPSIMAGE@
+ LIBS		=	$(LINKCUPS) $(COMMONLIBS)
+ ONDEMANDFLAGS	=	@ONDEMANDFLAGS@
+-- 
+2.7.2
+
-- 
2.7.2

[Buildroot] [PATCH] package/cups: fix static linking with GnuTLS

[Thomas Petazzoni]

Dear J?rg Krause,

On Sun, 28 Feb 2016 17:07:20 +0100, J?rg Krause wrote:
> cups forgets to link against the libs found by pkg-config if it is build with
> GnuTLS support.

If this was true, then it would not only fail in static linking
scenarios, but also in dynamic linking scenarios.

What apparently is happening is that libcups.so is properly linked
against libgnutls.so, so that when you link a binary against
libcups.so, everything works fine.

However, when you switch to static linking, this doesn't work, because
library dependencies are not recursively taken into account.

While your fix probably works (I haven't tested it), it has the
drawback of linking the cups binaries directly with libgnutls.so even
in a dynamic linking scenario, while this is not really needed.

This is normally fixed with pkg-config by using the Libs.private field,
but here we are *inside* a given package, so the pkg-config files have
not yet been installed by the time we link the cups binaries.

I think this problem is normally handled by libtool, but since cups is
using only autoconf and not automake/libtool... Maybe we should consult
with the cups developers?

Arnout, Yann, do you have other advises?

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH] package/cups: fix static linking with GnuTLS

[Arnout Vandecappelle]

On 02/28/16 23:00, Thomas Petazzoni wrote:
> This is normally fixed with pkg-config by using the Libs.private field,
> but here we are *inside* a given package, so the pkg-config files have
> not yet been installed by the time we link the cups binaries.
> 
> I think this problem is normally handled by libtool, but since cups is
> using only autoconf and not automake/libtool... Maybe we should consult
> with the cups developers?

 Well, inside a package, it's the responsibility of the package build system to
link with all required libraries (in the required order). That can either be
handled by a helper like libtool, or the Makefile should handle it manually.

 In other words: I beliver Joerg's fix is the correct one.

 Regards,
 Arnout

> 
> Arnout, Yann, do you have other advises?


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF

[Buildroot] [PATCH] package/cups: fix static linking with GnuTLS

[Thomas Petazzoni]

Dear Arnout Vandecappelle,

On Tue, 1 Mar 2016 23:54:59 +0100, Arnout Vandecappelle wrote:

>  Well, inside a package, it's the responsibility of the package build system to
> link with all required libraries (in the required order). That can either be
> handled by a helper like libtool, or the Makefile should handle it manually.
> 
>  In other words: I beliver Joerg's fix is the correct one.

As I said in my reply: the issue with Joerg fix is that in the dynamic
linking case, it creates useless additional NEEDED entries in the
binaries, which are not needed since those binaries are already linked
with libcups.so, which itself is linked with libgnutls.so.

Now whether it strongly matters can be discussed, but it is for sure
not very elegant.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[Buildroot] [PATCH] package/cups: fix static linking with GnuTLS

[Thomas Petazzoni]

Hello,

On Sun, 28 Feb 2016 17:07:20 +0100, J?rg Krause wrote:
> cups forgets to link against the libs found by pkg-config if it is build with
> GnuTLS support.
> 
> Otherwise, static build fails with:
> ../cups/libcups.a(tls.o): In function `http_gnutls_create_credential':
> cups-2.1.2/cups/tls-gnutls.c:762: undefined reference to `gnutls_x509_crt_init'
> [..]
> 
> Fixes:
> http://autobuild.buildroot.net/results/205/20509b7d1edc73dc2a7622f2ae7dbf9f6665a918/
> http://autobuild.buildroot.net/results/b86/b86d685caf8cf812f9505fca2de36fb8c18baee1/
> 
> Patch is sent upstream.
> 
> Signed-off-by: J?rg Krause <joerg.krause@embedded.rocks>
> ---
>  .../cups/0004-Fix-static-linking-with-GnuTLS.patch | 39 ++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>  create mode 100644 package/cups/0004-Fix-static-linking-with-GnuTLS.patch

In the end, since nobody ever worked on a better solution, I applied
your patch (together with a bump to cups 2.1.4).

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com