[39/39] Update the buildsystem for KConfig finding Qt

Commit Message

Stefan Lippers-Hollmann Oct. 16, 2015, 4:12 a.m. UTC

Hi

On 2015-09-22, Thiago Macieira wrote:
> The buildsystem will now only search for Qt 4 and Qt 5. Support for Qt 2
> and 3 was dropped in the previous commits (Qt 3 was EOL'ed in 2010 or
> so...).
> 
> For Qt 5, to be future-proof with the future direction notice appearing
> in the 5.5 release, C++11 support is automatically enabled.
[...]
> --- a/scripts/kconfig/Makefile
> +++ b/scripts/kconfig/Makefile
[...]
> +	@set -e; $(kecho) "  CHECK   qt"; \
> +	qtver=`qmake -query QT_VERSION` || { \
> +	    echo >&2 "*"; \
> +	    echo >&2 "* qmake failed."; \
> +	    echo >&2 "*"; \
> +	    exit 1; \
> +	}; \
[...]

"qmake -query QT_VERSION" appears to be a little fragile on Debian 
with both qt4-qmake and qt5-qmake installed, as it reports back 
"4.8.7" by default. The actual qmake is hiding behind qtchooser
(/usr/bin/qmake -> qtchooser) and will report different environments
based on the chosen personality:

$ qmake -query QT_VERSION
4.8.7

$ QT_SELECT=5 qmake -query QT_VERSION
5.4.2

While I'm not quite sure what would be the best kind of test
here (and if qtchooser can be commonly expected), the following 
might provide another approach to query the most recent installed 
qt version:

$ qtchooser --list-versions | grep ^[0-9]*$ | sort | tac | head -n1
5

(and then exporting QT_SELECT=5 to the rest of the build).

Another approach which appears to work for me (with both qt4 and qt5) 
would be this, but I'm not quite sure if this would be a good solution:


Regards
	Stefan Lippers-Hollmann
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Comments

Michal Marek Oct. 16, 2015, 9:47 a.m. UTC | #1

On 2015-10-16 06:12, Stefan Lippers-Hollmann wrote:
> Hi
> 
> On 2015-09-22, Thiago Macieira wrote:
>> The buildsystem will now only search for Qt 4 and Qt 5. Support for Qt 2
>> and 3 was dropped in the previous commits (Qt 3 was EOL'ed in 2010 or
>> so...).
>>
>> For Qt 5, to be future-proof with the future direction notice appearing
>> in the 5.5 release, C++11 support is automatically enabled.
> [...]
>> --- a/scripts/kconfig/Makefile
>> +++ b/scripts/kconfig/Makefile
> [...]
>> +	@set -e; $(kecho) "  CHECK   qt"; \
>> +	qtver=`qmake -query QT_VERSION` || { \
>> +	    echo >&2 "*"; \
>> +	    echo >&2 "* qmake failed."; \
>> +	    echo >&2 "*"; \
>> +	    exit 1; \
>> +	}; \
> [...]
> 
> "qmake -query QT_VERSION" appears to be a little fragile on Debian 
> with both qt4-qmake and qt5-qmake installed, as it reports back 
> "4.8.7" by default.

On openSUSE, I had to change qmake and moc to qmake-qt5 and moc-qt5,
respectively. But I don't think that it is a reason to call it fragile.
make xconfig works fine if qmake defaults to Qt4 (which seems to be the
predominant choice nowadays), but it will continue work once
distributions start preferring Qt5. I don't think users have such strong
preference as to which Qt version to build against. In the end, it's a
simple application with three windows and some buttons.

Michal
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Thiago Macieira Oct. 16, 2015, 3:28 p.m. UTC | #2

On Friday 16 October 2015 06:12:41 Stefan Lippers-Hollmann wrote:
> > +     @set -e; $(kecho) "  CHECK   qt"; \
> > +     qtver=`qmake -query QT_VERSION` || { \
> > +         echo >&2 "*"; \
> > +         echo >&2 "* qmake failed."; \
> > +         echo >&2 "*"; \
> > +         exit 1; \
> > +     }; \
> 
> [...]
> 
> "qmake -query QT_VERSION" appears to be a little fragile on Debian 
> with both qt4-qmake and qt5-qmake installed, as it reports back 
> "4.8.7" by default. The actual qmake is hiding behind qtchooser
> (/usr/bin/qmake -> qtchooser) and will report different environments
> based on the chosen personality:

Since xconfig still builds with Qt 4, I didn't feel the need to force the 
choice for Qt 5. If your environment is qtchooser, then you can just set 
QT_SELECT=5 before running "make xconfig".

Patch

--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -227,6 +227,7 @@  $(obj)/.tmp_qtcheck: $(src)/Makefile
 # Qt needs some extra effort...
 $(obj)/.tmp_qtcheck:
 	@set -e; $(kecho) "  CHECK   qt"; \
+	QT_SELECT=5 qmake -query QT_VERSION >/dev/null 2>&1 && export QT_SELECT=5 ||: ; \
 	qtver=`qmake -query QT_VERSION` || { \
 	    echo >&2 "*"; \
 	    echo >&2 "* qmake failed."; \