[Buildroot] Analysis of build failures

[Thomas Petazzoni]

Dear Richard Genoud,

On Mon, 4 May 2015 16:57:59 +0200, Richard Genoud wrote:

> >  > We currently only allow BR2_PACKAGE_QT_QT_COORD_TYPE_DOUBLE for soft
> >  > float toolchains, but perhaps it needs to also be disallowed for mips64?
> >  > Richard, care to take a look?
> >
> > QT_COORD_TYPE_DOUBLE also causes issues with python-pyqt because of
> > qreal* -> float* conversion. Could you take a look?
> >
> > http://autobuild.buildroot.net/results/891/891dc6ad46039740867a0b436281fc489cfb2772/build-end.log
> 
> yes, no problem.

And I also believe
http://autobuild.buildroot.org/results/3a7/3a70305be4a78af9404b0bd027dbcdd011ca01b3/build-end.log
is caused by BR2_PACKAGE_QT_QT_COORD_TYPE_DOUBLE:

../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QPen::setWidthF(float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QTransform::translate(float, float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QMatrix::setMatrix(float, float, float, float, float, float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QTransform::rotate(float, Qt::Axis)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QColor::setRgbF(float, float, float, float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QPen::setDashOffset(float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QColor::setAlphaF(float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QPen::setMiterLimit(float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QTransform::QTransform(float, float, float, float, float, float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QColor::setCmykF(float, float, float, float, float)'
../../qt4/src/.libs/libpoppler-qt4.so: undefined reference to `QPen::setDashPattern(QVector<float> const&)'

The libpoppler code is expecting "float" arguments for all these
functions, but they are now taking "double" instead.

Seems like using a double type is breaking a lot of assumptions of
existing applications and libraries. Do we really want to support this
option?

I would personally suggest to revert the patch for now in 2015.05, and
take the time to make sure it is properly tested with all the Qt-based
libraries and applications.

Richard, what do you think?

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