QMake. Legendary scope switch CONFIG(debug, debug|release)

[Algirdasss]

Hy,

I and many other developers came to this point, when project debug and release versions must have some different config. In QMake docs everything seems very easy ... just use "debug { ... }" or "release { ... }" and you have what you want, but that that's not so easy if one is using QtCreator.

For half of day I was searching for normal explanation in the internet what a heck these parameters mean in the config function: "CONFIG (debug, debug|release)" or "CONFIG (release, debug|release)". There is some info in QMake docs but it does not make much sense for me. What exactly the second parameters does??

[Franzk]

Here's a little test .pro:
@CONFIG(debug) {
message(debug)
}
CONFIG(release) {
message(release)
}
CONFIG(debug, debug|release) {
message("debug, debug|release")
}
CONFIG(release, debug|release) {
message("release, debug|release")
}
@

With the outputs:
@$ qmake
Project MESSAGE: debug
Project MESSAGE: release
Project MESSAGE: debug, debug|release

$ qmake CONFIG-=release CONFIG+=debug
Project MESSAGE: debug
Project MESSAGE: debug, debug|release

$ qmake CONFIG-=release CONFIG-=debug

$ qmake CONFIG+=release CONFIG-=debug
Project MESSAGE: release
Project MESSAGE: release, debug|release
@
The second parameter seems to be which configuration options to check for. If I change the last check into
@CONFIG(release, debug|unrelease) {
message("release, debug|release")
}@

@$ qmake CONFIG+= release CONFIG-=debug
Project MESSAGE: release
@

If I change the check into
@CONFIG(release, release) {
message("release, debug|release")
}@

I get
@$ qmake CONFIG+=release CONFIG+=debug
Project MESSAGE: debug
Project MESSAGE: release
Project MESSAGE: debug, debug|release
Project MESSAGE: release, debug|release
@

Besides specifying the items to check for, some seem to take precedence. I'm not all too sure how this is determined. Anyway, I hope this at least clarifies something.