I am trying to write a Qt .pro file that will run a set of commands, without compiling anything else first. Setting TEMPLATE=aux allows me to run just the script, and with help from this answer I have the following .pro file
# Target and build folders
TARGET = MySuperLibrary.dll
DESTDIR = ../../BuildAll
# Creates a Makefile for not building anything.
TEMPLATE = aux
extralib.target = extra
extralib.commands = echo \"Build the library\";
extralib.depends =
QMAKE_EXTRA_TARGETS += extralib
PRE_TARGETDEPS = extra
The problem is that the script commands are run every time, but I don't want them to run if the target file already exists. How should I modify the file so that the extralib commands are not run if the target file already exists?
Edit 16.01.2021
Following from zgyarmati's answer, I have modified the pro file as follows. Note that the new mytarget.commands actually generates the target dll and gives it a new timestamp. Unfortunately, this modified pro file still generates the dll every time it is run. Naturally the real script I want to run to generate this dll takes about ten minutes, so I really do not want it to run every time I build the project.
TARGET = MySuperLibrary.dll
DESTDIR = ../../BuildAll
# Creates a Makefile for not building anything.
TEMPLATE = aux
DESTDIR_WIN = $${DESTDIR}
DESTDIR_WIN ~= s,/,\\,g
mytarget.target = $${DESTDIR_WIN}\\$${TARGET}
mytarget.commands = echo \"MyDll\" > $${DESTDIR_WIN}\\$${TARGET}
mytarget.depends = mytarget2
mytarget2.commands = @echo Building $$mytarget.target
QMAKE_EXTRA_TARGETS += mytarget mytarget2
PRE_TARGETDEPS += mytarget2
