Multiple spec files in one directory

[nthallen]

There are various reasons why one might want to have multiple instrument configurations defined within a single experiment:

• Realtime operation versus simulation
• Options for changing data rates under different circumstances
• Supporting different hardware complements With the module structure, it is fairly easy to cut out a subsystem or alter the data rate. The maintain two (or more) distinct configurations:
• Create two (or more .spec files)
• Define prefix in all spec files to match the original. This prevents the implicit creation of multiple collection programs with different names. One remaining difficulty is managing the VERSION file. The different configurations will most likely have incompatible TM frames, so they will require different VERSIONs. This could be resolved with a simple module that would copy in the appropriate version file:
• Module Version src=cfg3.ver The VERSION file itself should then be removed from source control while adding in the version sources.

Source control is also complicated where generated source files change with different configurations. Those files could be removed from source control easily enough, since they are in fact easily regenerated. Assuming the relevant compilers are fairly stable, having the source should be sufficient to know what the output files looked like, but it may be early to assume that.

[nthallen]

VERSION is now solved with Version module.

Setting prefix prevents creating multiple collection programs as noted above, but it does mean that all specs will produce $prefix.pcm, so we lose the benefit of having the pcm file in source control, which gives a useful check on whether a version bump is required. A solution could be as simple as specifying the PCMFILE in the .spec file.

Other generated code that comes and goes is a minor problem. The files get dropped from .gitignore, so then they show up as untracked in git status. They could be removed by make clean, but that does mean that the next run of make will require a rerun of appgen.

[nthallen]

If PCMFILE were spec-specific, saverun would need to be checked to make sure it saves the right one.

Alternately, make sure the prefix is actually different between different spec files.