Appgen best practices

Driver distribution

The standard directory layout for an experiment looks like:

• src
  • TM
    • MyExp.spec
    • ...
  • MyDriver
    • MyDriver.cc
    • TM
      • MyDriver.agm
      • ...

The standard method for building the instrument software is to run

$ make distribution

in src/TM. We would like to make sure that when we do that we will be assured of getting the latest updates from MyDriver and the MyDriver Module. For the most part, appgen takes care of that. It knows that it must regenerate source files if the templates have been changed. It does not directly address making sure the driver itself is up to date.

The driver for the SCoPEx PropMtr has the current best approach. The idea is to add the driver executable to the DISTRIB list, but also declare it as a .PHONY target. That seems to prevent make from trying to build it using default rules.* Then add an explicit rule to run make in the driver's directory.

DISTRIB = @MODDIR@/../MyDriver
CPPFLAGS = -I @MODDIR@/..
%%
.PHONY : clean-MyDriver @MODDIR@/../MyDriver
@MODDIR@/../MyDriver :
	$(MAKE) --directory=@MODDIR@/..
clean-dist : clean-MyDriver
clean-MyDriver :
	$(MAKE) --directory=@MODDIR@/.. clean

*I had previously attempted adding the rule without the .PHONY definition, and make would go ahead and apply a default rule, seeing a matching .cc file in the driver's directory and assuming it could build the driver with that alone. That usually fails because there is more to the driver's build configuration that is specified in its own Makefile. The .PHONY definition seems to be the key to getting this to work reliably.