qt5webengine: new package

This patch is based on works [1] and [2].

With this patch, one can run the Qt5 WebEngine quicknanobrowser sample
with the following options.

	BR2_TOOLCHAIN_BUILDROOT_LIBC="glibc" and
	BR2_TOOLCHAIN_BUILDROOT_CXX (Qt 5 needs a toolchain w/ wchar, NPTL, C++,
	dynamic library; for now it builds only with glibc)
	BR2_PACKAGE_LIBERATION (Qt needs at least one font)
	BR2_PACKAGE_QT5BASE_EXAMPLES (to install quicknanobrowser sample)
	BR2_PACKAGE_QT5BASE_GIF (do display gif)
	BR2_PACKAGE_QT5BASE_JPEG (do display jpeg)
	BR2_PACKAGE_QT5BASE_PNG (do display png)
	BR2_PACKAGE_QT5QUICKCONTROLS (needed by webengine)
	BR2_PACKAGE_QT5QUICKCONTROLS2 (needed by webengine)
	BR2_PACKAGE_QT5WEBENGINE (because it is what we want)

Qt WebEngine requires an Open(E)GL-capable backend. As an example, the
package rpi-userland must be enabled to build for a rpi.

	BR2_PACKAGE_RPI_USERLAND (to enable OpenGL ES backend)

To browse for HTTPS websites, please consider adding the following
options as well for SSL/TLS.

	BR2_PACKAGE_CA_CERT (for certificates)
	BR2_PACKAGE_NTPD (to sync date for certificates)

Since version 5.9, chromium requires udev at runtime (see note 4).

	BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV (input backend)

To run quicknanobrowser

	# cd /usr/lib/qt/examples/webengine/quicknanobrowser/
	# ./quicknanobrowser https://www.buildroot.org/

Note: The chromium.inc has been generated using the following command.

	( echo 'CHROMIUM_LICENSE_FILES = \' &&
	  cd output/build/qt5webengine-5.9.1/ && \
	  find "src/3rdparty/chromium/" -type f -iname "*LICENSE*" -o -iname "*COPYING*" -o -iname "*GPL*" | \
	  sed -e '/\.asm$/d' \
	      -e '/\.h$/d' \
	      -e '/\.c$/d' \
	      -e '/\.cc$/d' \
	      -e '/\.cpp$/d' \
	      -e '/\.pyc\?$/d' \
	      -e '/\.pl$/d' \
	      -e '/\.sha1$/d' \
	      -e '/\.patch$/d' \
	      -e '/licensecheck/d' \
	      -e 's,^,\t,' \
	      -e 's,$, \\,' | \
	  sort && \
	  echo '' ) >package/qt5/qt5webengine/chromium.inc

Note 2: Since 5.9.1, the chromium's copy of opus fails with neon [3].
Qt WebEngine can uses buildroot ffmpeg copy which compiles fine (using
qmake flag WEBENGINE_CONFIG+=use_system_ffmpeg). It implies selecting
the following options.

	BR2_PACKAGE_FFMPEG
	BR2_PACKAGE_OPUS
	BR2_PACKAGE_LIBVPX
	BR2_PACKAGE_WEBP
	BR2_PACKAGE_WEBP_DEMUX

	In file included from ../../3rdparty/chromium/third_party/opus/src/silk/arm/NSQ_neon.c:31:0:
	/home/gportay/src/buildroot/output-rpi3-qt5.9/host/lib/gcc/arm-buildroot-linux-gnueabihf/6.4.0/include/arm_neon.h:8997:1: error: inlining failed in call to always_inline ‘vld1q_s32’: target specific option mismatch
	 vld1q_s32 (const int32_t * __a)
	 ^~~~~~~~~
	../../3rdparty/chromium/third_party/opus/src/silk/arm/NSQ_neon.c:40:15: note: called from here
	     int32x4_t coef0 = vld1q_s32(coef32);
		       ^~~~~
	../../3rdparty/chromium/third_party/opus/src/silk/arm/NSQ_neon.c: At top level:
	cc1: warning: unrecognized command line option ‘-Wno-#pragma-messages’

Note 3: Version 5.6.2 causes a build issue while building chromium. The
build against this version is disabled until the release 5.6.3 is out.

Note 4: Here is trace when udev does not run

	# cd /usr/lib/qt/examples/webengine/quicknanobrowser
	# ./quicknanobrowser
	QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
	Unable to query physical screen size, defaulting to 100 dpi.
	To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters).
	[0101/000248.161973:WARNING:resource_bundle_qt.cpp(114)] locale_file_path.empty() for locale
	[0101/000248.384693:WARNING:resource_bundle_qt.cpp(114)] locale_file_path.empty() for locale
	[202:223:0101/000248.484954:FATAL:udev_loader.cc(38)] Check failed: false.
	#0 0x0000742b93de <unknown>
	#1 0x0000742c3c38 <unknown>
	#2 0x000073e1e1aa <unknown>
	#3 0x000073e1d96e <unknown>
	#4 0x000073e1defa <unknown>
	#5 0x000074af6364 <unknown>
	#6 0x000074302878 <unknown>
	#7 0x0000742c8fee <unknown>
	#8 0x0000742c9f44 <unknown>
	#9 0x0000742ca21e <unknown>
	#10 0x0000742cac4c <unknown>
	#11 0x0000742c87b2 <unknown>
	#12 0x0000742da4f6 <unknown>
	#13 0x000073ed9d38 <unknown>
	#14 0x000073eda03c <unknown>
	#15 0x0000742e9aec <unknown>
	#16 0x0000742e71dc <unknown>

	Aborted

Note 5: On rpi and depending on what is insinde the .config, more GPU
memory should be allocated to run properly qt samples.

	#0 0x0000742c63de <unknown>
	#1 0x0000742d0c38 <unknown>
	#2 0x0000749d7bde <unknown>
	#3 0x0000749e3c70 <unknown>
	#4 0x00007530227c <unknown>
	#5 0x000075302480 <unknown>
	#6 0x0000752fb1e4 <unknown>
	#7 0x00007430f878 <unknown>
	#8 0x0000742d5fee <unknown>
	#9 0x0000742d6f44 <unknown>
	#10 0x0000742d721e <unknown>
	#11 0x0000742d7ad6 <unknown>
	#12 0x0000742d57b2 <unknown>
	#13 0x0000742e74f6 <unknown>
	#14 0x0000742f6a74 <unknown>
	#15 0x0000742f41dc <unknown>

	Received signal 6
	#0 0x0000742c63de <unknown>
	#1 0x0000742c66a0 <unknown>
	#2 0x0000725b5d10 <unknown>
	[end of stack trace]
	qml: Render process exited with code 256 (abnormal exit)

	# mount /dev/mmcblk0p1 /mnt
	# sed '/^gpu_mem_/s,=.*,=200,' -i /mnt/config.txt
	# umount /mnt

Note 6: The first patch fixes a build issue when samples are compiled
without the support of printing [4]. This patch is already merged in
branch 5.9 [5] and concerns only 5.9.1.

	085c2c52 Always compile QWebEnginePage::print

It fixes the error below.

	.obj/browsermainwindow.o: In function `BrowserMainWindow::printRequested(QWebEnginePage*)': browsermainwindow.cpp:(.text+0x2cc0): undefined reference to `QWebEnginePage::print(QPrinter*, QWebEngineCallback<bool> const&)'

The second patch loads both libEGL and libGLESv2 symbols implicitly
instead of loading them with explicitly using hard-coded locations. It
fixes a bug when providers of lib*GL does not create libraries named
libEGL.so.1 and libGLESv2.s2 [6]. This patch is already merged in branch
5.9 [7].

	d4c621f6 Load libEGL and libGLES2 symbols implicitly

It fixes the error below.

	[327:347:1221/085837:ERROR:surface_factory_qt.cpp(68)] Failed to load /usr/lib/libGLESv2.so.2: /usr/lib/libGLESv2.so.2: cannot open shared object file: No such file or directory

[1]: http://lists.busybox.net/pipermail/buildroot/2015-July/132010.html
[2]: https://patchwork.ozlabs.org/patch/640633/
[3]: https://patchwork.ozlabs.org/patch/791332/
[4]: https://bugreports.qt.io/browse/QTBUG-61510
[5]: https://codereview.qt-project.org/#/c/198041/
[6]: https://bugreports.qt.io/browse/QTBUG-57761
[7]: https://codereview.qt-project.org/#/c/199554/

Cc: Akihiko Odaki <akihiko.odaki.4i@stu.hosei.ac.jp>
Cc: Julien Corjon <corjon.j@ecagroup.com>
Signed-off-by: Gaël PORTAY <gael.portay@savoirfairelinux.com>
[Arnout:
 - move more dependencies to _ARCH_DEPENDS;
 - mention all toolchain dependencies in the comments]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

1 files changed, 1 insertions, 0 deletions

diff --git a/DEVELOPERS b/DEVELOPERS
index 536ec5680a..e34802f2ba 100644
--- a/DEVELOPERS
+++ b/DEVELOPERS
@@ -643,6 +643,7 @@ F:	package/zxing-cpp/
 
 N:	Gaël Portay <gael.portay@savoirfairelinux.com>
 F:	package/qt5/qt5virtualkeyboard/
+F:	package/qt5/qt5webengine/
 
 N:	Gary Bisson <gary.bisson@boundarydevices.com>
 F:	board/boundarydevices/