Variables and Scopes

Jan. 2025.

The table below describes the variable and parameter types defined in the McCode meta language, and the role they play in the generated code. This is not exhaustive, but describes the most important cases - and conditions for possible name clashes in cogen3.

what	where	use	symbol C scope	alternative access
instr input par	instr file DEFINE INSTRUMENT(type parname=default)	Runtime control	instrument section of init finally code-generated functions	INSTRUMENT_GETPAR() macro, instrument->_parameters.parname, _instrument_var.parameters.parname
instr var	instr file DECLARE	Instrument variables, comp init, sim flow control,...	global (For OpenACC/GPU use, add: #pragma acc declare create(var) #pragma acc update device(var))	symbol may be re-initialised locally via instr or comp pars, uservars or local variables
user var	instr / comp file USERVARS (become part of _particle)	Pass particle-dependent info along instrument	EXTEND section of comp trace functions, and cogen'd raytrace functions	_particle->varname from component trace or cogen'd raytrace functions
comp par	comp file DEFINE	Comp initialisation	component init, trace, finally, save and display functions (when called with the appropriate comp var)	COMP_GETPAR3(type, compname, par), _compname->_parameters.par, COMP_GETPAR(compname,par) for simple types
comp var	comp file DECLARE	Comp internal values (pr. instance)	none	COMP_GETPAR3(type, compname, var), _comp->_parameters.var, COMP_GETPAR(compname,var) for simple types
comp share	comp file SHARE	Common structs / functions pr. comp class	global	symbols may be overridden locally by instr or comp pars, user vars or local variables