[1/1] qt: fix build for arm with BR2_STATIC_LIBS

Some Buildroot-generated static toolchains for ARM do not have
dlfcn.h header, which breaks builds of qt-4.8.7 because its
QtCore's plugin loader expects this header to be present (and
dynamic libraries to be supported). For certain platforms without
dynamic libraries, there is a QT_NO_DYNAMIC_LIBRARY constant
defined in plugin loader's source. This patch puts that constant
into Qt's build environment if Buildroot is configured without
shared library support, and prevents plugin loader from defining
it if it has already been defined.

Fixes:
- http://autobuild.buildroot.net/results/11a4c19638ca211bd2a424fd92602166235c9433
- http://autobuild.buildroot.net/results/c056e8781558267f6971a5f017f47e90dcf24e07
- http://autobuild.buildroot.net/results/b8f34afa8686e890a1a3882a52081bb6a3b9c13b
and several others.

Signed-off-by: Alexander Lukichev <alexander.lukichev@gmail.com>
---
 package/qt/0009-no-dynamic-library-plugins.patch | 27 ++++++++++++++++++++++++
 package/qt/qt.mk                                 |  4 ++++
 2 files changed, 31 insertions(+)
 create mode 100644 package/qt/0009-no-dynamic-library-plugins.patch

On 06-10-15 11:56, Alexander Lukichev wrote:
> Some Buildroot-generated static toolchains for ARM do not have
> dlfcn.h header, which breaks builds of qt-4.8.7 because its
> QtCore's plugin loader expects this header to be present (and
> dynamic libraries to be supported). For certain platforms without
> dynamic libraries, there is a QT_NO_DYNAMIC_LIBRARY constant
> defined in plugin loader's source. This patch puts that constant
> into Qt's build environment if Buildroot is configured without
> shared library support, and prevents plugin loader from defining
> it if it has already been defined.
> 
> Fixes:
> - http://autobuild.buildroot.net/results/11a4c19638ca211bd2a424fd92602166235c9433
> - http://autobuild.buildroot.net/results/c056e8781558267f6971a5f017f47e90dcf24e07
> - http://autobuild.buildroot.net/results/b8f34afa8686e890a1a3882a52081bb6a3b9c13b
> and several others.
> 
> Signed-off-by: Alexander Lukichev <alexander.lukichev@gmail.com>
> ---
>  package/qt/0009-no-dynamic-library-plugins.patch | 27 ++++++++++++++++++++++++
>  package/qt/qt.mk                                 |  4 ++++
>  2 files changed, 31 insertions(+)
>  create mode 100644 package/qt/0009-no-dynamic-library-plugins.patch
> 
> diff --git a/package/qt/0009-no-dynamic-library-plugins.patch b/package/qt/0009-no-dynamic-library-plugins.patch
> new file mode 100644
> index 0000000..3836677
> --- /dev/null
> +++ b/package/qt/0009-no-dynamic-library-plugins.patch
> @@ -0,0 +1,27 @@
> +Do not define QT_NO_DYNAMIC_LIBRARY if it is already defined
> +
> +QtCore plugin loader behaves correctly on platforms that do not support
> +dynamic libraries. This is implemented by QT_NO_DYNAMIC_LIBRARY constant
> +defined at compile time in the loader's source for specific platforms.
> +Since Buildroot does not have a separate platform defined for it in
> +mkspecs, if shared libraries are not supported by its configuration, the
> +constant is specified in Qt's build environment. This patch prevents
> +compilation error in such cases.

 I'm sorry, but I fail to understand how there can be a compilation error...
We're not building for VxWorks or NaCl, so why should there be a problem?

 Otherwise the patch looks good to me BTW.

 Regards,
 Arnout

> +
> +Signed-off-by: Alexander Lukichev <alexander.lukichev@gmail.com>
> +
> +diff -uNrp qt-4.8.7.orig/src/corelib/plugin/qlibrary_unix.cpp qt-4.8.7/src/corelib/plugin/qlibrary_unix.cpp
> +--- qt-4.8.7.orig/src/corelib/plugin/qlibrary_unix.cpp	2015-05-07 17:14:48.000000000 +0300
> ++++ qt-4.8.7/src/corelib/plugin/qlibrary_unix.cpp	2015-10-06 08:53:27.189232642 +0300
> +@@ -56,9 +56,11 @@
> + #include <string.h>
> + #endif
> + 
> ++#ifndef QT_NO_DYNAMIC_LIBRARY
> + #if (defined(Q_OS_VXWORKS) && !defined(VXWORKS_RTP)) || defined (Q_OS_NACL)
> + #define QT_NO_DYNAMIC_LIBRARY
> + #endif
> ++#endif
> + 
> + QT_BEGIN_NAMESPACE
> + 
> diff --git a/package/qt/qt.mk b/package/qt/qt.mk
> index e0e5d22..a64d32f 100644
> --- a/package/qt/qt.mk
> +++ b/package/qt/qt.mk
> @@ -203,6 +203,10 @@ else
>  QT_CONFIGURE_OPTS += -static
>  endif
>  
> +ifeq ($(BR2_STATIC_LIBS),y)
> +QT_CONFIGURE_OPTS += -D QT_NO_DYNAMIC_LIBRARY
> +endif
> +
>  ifeq ($(BR2_ENDIAN),"LITTLE")
>  QT_CONFIGURE_OPTS += -little-endian
>  else
>

Hi, Arnout!

  Thanks for taking a look!

On 10/07/2015 12:51 AM, Arnout Vandecappelle wrote:
>> --- /dev/null
>> +++ b/package/qt/0009-no-dynamic-library-plugins.patch
>> @@ -0,0 +1,27 @@
>> +Do not define QT_NO_DYNAMIC_LIBRARY if it is already defined
[...]
>> ++#ifndef QT_NO_DYNAMIC_LIBRARY
>> + #if (defined(Q_OS_VXWORKS) && !defined(VXWORKS_RTP)) || defined (Q_OS_NACL)
>> + #define QT_NO_DYNAMIC_LIBRARY
>> + #endif
>> ++#endif

>  I'm sorry, but I fail to understand how there can be a compilation error...
> We're not building for VxWorks or NaCl, so why should there be a problem?

Indeed. I will remove unnecessary Qt patch and send a new version. Thanks again!

--
Best regards,
  Alexander Lukichev