Qt version checking at the project-file

[roxton]

Hello! How I can to check the Qt version dependency at the .pro-file?
In the pseudocode, I need something like this:


if (QT_VERSION < 4.4)
{
show some message; abort configuration;
}

[spirit]

read this
http://doc.trolltech.com/4.4/qmake-variable-reference.html#qt-version
http://doc.trolltech.com/4.4/qmake-function-reference.html#contains-variablename-value



contains(QT_VERSION, 4.4.1) {
message(4.4.1)
}

[jpn]

This is how we do it in LibQxt project:


#check Qt version
QT_VERSION = $$[QT_VERSION]
QT_VERSION = $$split(QT_VERSION, ".")
QT_VER_MAJ = $$member(QT_VERSION, 0)
QT_VER_MIN = $$member(QT_VERSION, 1)

lessThan(QT_VER_MAJ, 4) | lessThan(QT_VER_MIN, 2) {
error(LibQxt requires Qt 4.2 or newer but Qt $$[QT_VERSION] was detected.)
}

It would be nice if there was a built-in version check function in qmake...

[roxton]

Thanks a lot!

[cth35]

This is how we do it in LibQxt project:


#check Qt version
QT_VERSION = $$[QT_VERSION]
QT_VERSION = $$split(QT_VERSION, ".")
QT_VER_MAJ = $$member(QT_VERSION, 0)
QT_VER_MIN = $$member(QT_VERSION, 1)

lessThan(QT_VER_MAJ, 4) | lessThan(QT_VER_MIN, 2) {
error(LibQxt requires Qt 4.2 or newer but Qt $$[QT_VERSION] was detected.)
}

It would be nice if there was a built-in version check function in qmake...

Humm the code above will display the message for a 5.0 version also no ?

[ChrisW67]

Yes, but that code is from 2008 when there was no Qt5 only Qt3 and Qt4. LibQxt no longer checks to exclude Qt3.

For Qt4+ you can just:


greaterThan(QT_MAJOR_VERSION, 4) {
}
equals(QT_MAJOR_VERSION, 5) {
}

# or more complex stuff like
equals(QT_MAJOR_VERSION, 4):lessThan(QT_MINOR_VERSION, 8) {
}

QT_MAJOR_VERSION, QT_MINOR_VERSION, and QT_PATCH_VERSION are defined for you.