Qt project file: Add libs depending on Kit

Question

I have a QT project which runs on x86 linux and ARM linux embedded (yocto). For each platform I defined a Kit within QtCreator referencing the appropriate compiler etc.

Now I want to add LIBS to my pro file, but I got different libraries on each platform. I didn't find a way to specify the LIBS-directive dependant on the compiling Kit.

I search something like:

if (Kit == "Desktop")
    LIBS += ...

if (Kit == "Embedded Yocto")
    LIBS += ...

How to achieve this? Thank you in advance

Answer 1

I scraped together a solution to the OP's problem by using the answer suggested by @vsz in the comments found here.

I have two kits, one for the local Desktop and one for the Target_ARM device, and I wanted a way to easily build for both of those without having to specially modify the .pro file or anything else. I followed the linked answer and added the following:

• In my Desktop kit (for both Debug and Release), I added CONFIG+=Desktop as an additional qmake argument in the qmake build step.
• For the Target_ARM kit, I added CONFIG+=Target_ARM in the same spot.

Now, this is where things shifted from the linked answer to the OP's problem. I didn't simply want #defineed variables in my code, I wanted to alter the behavior of qmake based on the selected kit. I don't know if the CONFIG built-in test function supports block designations or not (ie, CONFIG { _several lines here_ }), but it turned out I could copy and paste the CONFIG test function in front of each line that I wanted to be conditional; in fact I could string multiple CONFIGs together, like this:

CONFIG(Desktop, Desktop|Target_ARM):unix:!macx:CONFIG(debug, debug|release): LIBS += /path/to/Desktop/debug/lib
else:CONFIG(Desktop, Desktop|Target_ARM):unix:!macx:CONFIG(release, debug|release): LIBS += /path/to/Destop/release/lib

As it suggests, the above statement will run qmake with the appropriate LIBS path depending on which kit and configuration I have selected. Desktop->debug will generate a Makefile with /path/to/Desktop/debug/lib in it whereas Desktop->release will generate a Makefile with /path/to/Desktop/release/lib. I have similar statements for the Target_ARM kit. Below is an example of selecting the correct INCLUDEPATH: Both tests will evaluate to true when Target_ARM->release is selected.

CONFIG(Target_ARM, Desktop|Target_ARM):CONFIG(release, debug|release): INCLUDEPATH += /include/path/for/Target_ARM/release

In all, I used this method to modify LIBS, INCLUDEPATH, DEPENDPATH, and PRE_TARGETDEPS. I have 4 possible configurations of include paths and libraries depending on which kit I select (Desktop or Target_ARM) and which build configuration I select (build or release). Once this is set up, there is no need to modify the .pro file, simply pick your kit, your build configuration, run qmake, then rebuild.

I don't know off the top of my head where the CONFIG+=Desktop (for example) data is stored, but I would guess in the .pro.user file. So if somebody pulls your .pro file from a repo, they may have to initially configure the project in this manner at least once, but not afterwards (as long as the .pro.user file persists). QT should really have an easy mechanism for doing this front-and-center, especially since one of their selling points is multiple-platform integration. If there's a better way of doing this, I haven't seen it on SO or in the QT documentation yet.

Answer 2

You have all qmake variables here: qt-project.org/doc/qt-4.8/qmake-function-reference.html

You can define a variable

KIT = Desktop
#KIT = EmbeddedYocto

And use contains function

contains( KIT, Desktop ) {
     LIBS += ...
}
contains( KIT, EmbeddedYocto ) {
     LIBS += ...
}