Environment variables and qmake

Is there a way to do a conditional compilation according to environment variables with qmake:

I am trying to recreate the following:

ifdef AMDAPPSDKROOT
INC_DIRS = "$(AMDAPPSDKROOT)include"
endif

ifdev NVSDKCOMPUTE_ROOT
INC_DIRS = "$(NVSDKCOMPUTE_ROOT)\OpenCL\common\inc"
endif

Also there is another problem

Even though I have done this:
INCLUDEPATH += "$NVSDKCOMPUTE_ROOT\OpenCL\common\inc"

where NVSDKCOMPUTE_ROOT is "C:\ProgramData\NVIDIA Corporation\NVIDIA GPU Computing SDK 4.2"

Even though I use double quotes, the gcc gets the path as separate words. Actually that part \NVIDIA Corporation\ is OK but the next: NVIDIA GPU Computing SDK 4.2 gets split into five words and causes errors. Why don't the double quotes work? My workaround was to copy these files to a folder without white spaces for now. Is this a bug or a feature.

I would like my project file to compile on 3-4 different configurations: Linux 32/64bit, Windows 7 32/64 bit with NVIDIA SDK or AMD SDK respectively depending on the available hardware.

Double quotes do not quote the whole path while being sent to gcc, they just make qmake treat it as a single token instead of splitting it into a list. It's best to explicitly escape all spaces, as far as I remember qmake has a function to do that (consult qmake manual).

Thanx! The function quote() did the trick. Although according to the documentation it is just a fancy way to put double quotes around a string.

I still cannot figure out how to check if environment variables are defined.

Have a look at qmake function reference. I guess you will find the answer contained in it :-)

Code:

---

AMDAPPSDKROOT = $$(AMDAPPSDKROOT)
!isEmpty(AMDAPPSDKROOT) {
  INC_DIRS = "$${AMDAPPSDKROOT}include"   
}

---