[Buildroot] [PATCH 3/3 v4] package/qt5/qt5webengine: fix build dependencies for autodetected packages

[Nathan Ford]

Hi Thomas,

In src/buildtools/configure.json some of the library dependencies have
had their auto detection disabled ( look for the key "autoDetect" in
the features section ), at least as of 5.14.2 ( I have not migrated to
newer for the projects I work on yet ).

I assumed that any lib that qt5webengine built itself was a hard
dependency, so if it is present in the buildroot build, use it,
otherwise let qt5webengine build its own. The alternative is to make
all those libs build dependencies of qt5webengine.

--Nate



On Thu, Sep 17, 2020 at 2:51 PM Thomas Petazzoni
<thomas.petazzoni at bootlin.com> wrote:
>
> On Wed, 16 Sep 2020 23:11:34 +0200
> "Yann E. MORIN" <yann.morin.1998 at free.fr> wrote:
>
> > +ifeq ($(BR2_PACKAGE_JSONCPP),y)
> > +QT5WEBENGINE_DEPENDENCIES += jsoncpp
> > +endif
> > +
> > +ifeq ($(BR2_PACKAGE_LCMS2),y)
> > +QT5WEBENGINE_DEPENDENCIES += lcms2
> > +endif
> > +
> > +ifeq ($(BR2_PACKAGE_LIBEVENT),y)
> > +QT5WEBENGINE_DEPENDENCIES += libevent
> > +endif
> > +
> > +ifeq ($(BR2_PACKAGE_LIBXML2),y)
> > +QT5WEBENGINE_DEPENDENCIES += libxml2
> > +endif
> > +
> > +ifeq ($(BR2_PACKAGE_LIBXSLT),y)
> > +QT5WEBENGINE_DEPENDENCIES += libxslt
> > +endif
> > +
> > +ifeq ($(BR2_PACKAGE_PROTOBUF),y)
> > +QT5WEBENGINE_DEPENDENCIES += protobuf
> > +endif
> > +
> > +ifeq ($(BR2_PACKAGE_SNAPPY),y)
> > +QT5WEBENGINE_DEPENDENCIES += snappy
> > +endif
>
> I am not 100% sure but I believe those dependencies do have options,
> much like the -webengine-ffmpeg option that PATCH 1/3 is using. If you
> look at ./src/core/configure.json in the qt5webengine sources, you can
> see:
>
>     "commandline": {
>         "options": {
>             "webengine-alsa": "boolean",
>             "webengine-embedded-build": "boolean",
>             "webengine-full-debug-info": "boolean",
>             "webengine-icu": { "type": "enum", "name": "webengine-system-icu", "values": { "system": "yes", "qt": "no" } },
>             "webengine-ffmpeg": { "type": "enum", "name": "webengine-system-ffmpeg", "values": { "system": "yes", "qt": "no" } },
>             "webengine-opus": { "type": "enum", "name": "webengine-system-opus", "values": { "system": "yes", "qt": "no" } },
>             "webengine-webp": { "type": "enum", "name": "webengine-system-libwebp", "values": { "system": "yes", "qt": "no" } },
>             "webengine-pepper-plugins": "boolean",
>             "webengine-printing-and-pdf": "boolean",
>             "webengine-proprietary-codecs": "boolean",
>             "webengine-pulseaudio": "boolean",
>             "webengine-spellchecker": "boolean",
>             "webengine-native-spellchecker": "boolean",
>             "webengine-extensions": "boolean",
>             "webengine-webrtc": "boolean",
>             "webengine-geolocation": "boolean",
>             "webengine-webchannel": "boolean",
>             "webengine-kerberos": "boolean",
>             "alsa": { "type": "boolean", "name": "webengine-alsa" },
>             "pulseaudio": { "type": "boolean", "name": "webengine-pulseaudio" },
>             "ffmpeg": { "type": "enum", "name": "webengine-system-ffmpeg", "values": { "system": "yes", "qt": "no" } },
>             "opus": { "type": "enum", "name": "webengine-system-opus", "values": { "system": "yes", "qt": "no" } },
>             "webp": { "type": "enum", "name": "webengine-system-libwebp", "values": { "system": "yes", "qt": "no" } },
>             "pepper-plugins": { "type": "boolean", "name": "webengine-pepper-plugins" },
>             "printing-and-pdf": { "type": "boolean", "name": "webengine-printing-and-pdf" },
>             "proprietary-codecs": { "type": "boolean", "name": "webengine-proprietary-codecs" },
>             "spellchecker": { "type": "boolean", "name": "webengine-spellchecker" },
>             "extensions": { "type": "boolean", "name": "webengine-extensions" },
>             "webrtc": { "type": "boolean", "name": "webengine-webrtc" }
>         }
>     },
>
> So it seems like if we have a -webengine-ffmpeg option, then we should
> also have many other options to enable (and perhaps disable ?) other
> optional features.
>
> However, I'm not sure to understand the difference between the
> "webengine-<something>" option and the corresponding "<something>"
> option.
>
> Also, it seems like some options such as webengine-ffmpeg or
> webengine-icu can take multiple values: they are enums and not
> booleans. should we use -webengine-ffmpeg=system for example ? Ditto
> for the other dependencies;
>
> For the record, the qt5webengine source code bundles chromium in
> ./src/3rdparty/, which itself bundles a bunch of things including
> ffmpeg in ./src/3rdparty/chromium/third_party/ffmpeg/ (do you like when
> a 3rdparty folder includes another third_party folder ?).
>
> Obviously, in the context of Buildroot, we'd prefer to use as few
> bundled libraries as possible, and use as much as possible system
> libraries.
>
> How is the configure.json above being parsed and used ?
>
> Thomas
> --
> Thomas Petazzoni, CTO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
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