Qt – C++ Qt – How to add “-std=c++11” to the makefile which is generated by qmake

Lazy Set

VARIABLE = value

Normal setting of a variable, but any other variables mentioned with the value field are recursively expanded with their value at the point at which the variable is used, not the one it had when it was declared

Immediate Set

VARIABLE := value

Setting of a variable with simple expansion of the values inside - values within it are expanded at declaration time.

Lazy Set If Absent

VARIABLE ?= value

Setting of a variable only if it doesn't have a value. value is always evaluated when VARIABLE is accessed. It is equivalent to

ifeq ($(origin VARIABLE), undefined)
  VARIABLE = value
endif

See the documentation for more details.

Append

VARIABLE += value

Appending the supplied value to the existing value (or setting to that value if the variable didn't exist)

You may need to do this in two passes.

In your qmake file, add the following line:

include( generated/generated.pri )

Then, at the end of your code_generator script, add the sources to the generated.pri file (using bash for the example, but the idea is the same for almost all languages):

rm generated/generated.pri
for file in $( ls generated/*.cpp ); do
    echo "SOURCES += ${file}" >> generated/generated.pri
done

The first time you run the qmake file, generated/generated.pri will presumably be empty. When you run make, it will populate the generated.pri file. The second time, it will recreate the make file (as a source .pri file changed), then compile again. You might be able to fiddle around with other commands which would do the second stage for you.