Does Qt offer a (guaranteed) debug definition?

Question

Does anyone know an officially supported way to include debug-build only code in Qt? For example:

#ifdef QT_DEBUG
// do something
#endif

Basically like Q_ASSERT but for more complex tests.

I can't seem to find any documentation which says that the Qt framework guarantees to define a debug macro. If there isn't, what would be a sensible unofficial way to implement this feature project wide?

Answer 1

Qt defines QT_NO_DEBUG for release builds. Otherwise QT_DEBUG is defined.

Of course you are free to specify any DEFINES in your .pro files and scope them for either debug or release.

Answer 2

An alternative is to write in your project file something like:

debug {
  DEFINES += MYPREFIX_DEBUG
}
release {
  DEFINES += MYPREFIX_RELEASE
}

Then you will not depend on the Qt internal definition.

Answer 3

For check debug mode:

#ifdef QT_DEBUG
    //Some codes
#endif

For check release mode:

#ifndef QT_DEBUG    //<== Please note... if not defined
    //Some codes
#endif