How to run QT's `lupdate`-tool with a `qmake CONFIG`? - qt

Question

This question has been posted before in the qt community: https://forum.qt.io/topic/106930/how-to-run-lupdate-with-a-qmake-config
I use such a construct in my project files:
LANGUAGES = de
TRANSLATION_NAME = authorization
include(../../gen_translations.pri)
where gen_translations.pri looks like so:
# parameters: var, prepend, append
defineReplace(prependAll) {
for(a,$$1):result += $$2$${a}$$3
return($$result)
}
TRANSLATIONS = $$prependAll(LANGUAGES, $$PWD/libs/$$TRANSLATION_NAME/translations/lib$${TRANSLATION_NAME}_, .ts)
TRANSLATIONS_FILES =
qtPrepareTool(LRELEASE, lrelease)
for(tsfile, TRANSLATIONS) {
qmfile = $$shadowed($$tsfile)
qmfile ~= s,.ts$,.qm,
qmdir = $$dirname(qmfile)
!exists($$qmdir) {
mkpath($$qmdir)|error("Aborting.")
}
command = $$LRELEASE -removeidentical $$tsfile -qm $$qmfile
system($$command)|error("Failed to run: $$command")
TRANSLATIONS_FILES += $$qmfile
}
for(qmentry, $$list($$TRANSLATIONS_FILES)) {
qmpath = $$OUT_PWD/../translations
qmpathname = $$replace(qmpath,/,)
qmpathname = $$replace(qmpathname,\.,)
qmpathname = $$replace(qmpathname,:,)
qmpathname = $$replace(qmpathname," ",)
qmentity = qmfiles_$${qmpathname}
eval($${qmentity}.files += $$qmentry)
eval($${qmentity}.path = $$qmpath)
INSTALLS *= $${qmentity}
}
It generates the *.qm files for me and moves them to a defined location with make install.
I do not want qmake to execute that whole stuff for each build on my developing machine. Therefore I want to make it conditional by wrapping it for qmake:
translate{
LANGUAGES = de
TRANSLATION_NAME = authorization
include(../../gen_translations.pri)
}
That way I can decide when I want to get *.qm files and when not.
But then I am unable to run lupdate on the project file beforehand because it is blocked by that conditional.
I am sure, that someone has a better idea to accomplish the task.
Thanks in advance.

Answer 1

I'm sharing here my recipe for the vmpk project. I've borrowed it from the Arora project (I think). It is much simpler than yours, and I let qmake to decide if it is necessary regenerate any .qm files when the output has been erased or the input .ts has changed, like any other compiler does.
updateqm.pri
# update translations
isEmpty(QMAKE_LRELEASE) {
win32:QMAKE_LRELEASE = $$[QT_INSTALL_BINS]\\lrelease.exe
else:QMAKE_LRELEASE = $$[QT_INSTALL_BINS]/lrelease
!exists($$QMAKE_LRELEASE) { QMAKE_LRELEASE = lrelease }
}
updateqm.input = TRANSLATIONS
updateqm.output = $$OUT_PWD/${QMAKE_FILE_BASE}.qm
updateqm.commands = $$QMAKE_LRELEASE ${QMAKE_FILE_IN} -qm $$OUT_PWD/${QMAKE_FILE_BASE}.qm
updateqm.CONFIG += no_link target_predeps
QMAKE_EXTRA_COMPILERS += updateqm
project.pro:
TRANSLATIONS += \
translations/project_en.ts \
translations/project_cs.ts \
translations/project_de.ts \
translations/project_es.ts \
translations/project_fr.ts \
translations/project_ru.ts
include(updateqm.pri)
With this project file you can do, as always:
lupdate project.pro
Anyway, Qt5 has a builtin CONFIG+=lrelease option that makes "updateqm.pri" deprecated.