[F2C transpilation] (driver level) convert interface to import

[MichaelSt98]

Convert interface to kernel calls (e.g., interface kernel ...) to the appropriate import (e.g., kernel_fc_mod, only: kernel_fc).

[github-actions]

Documentation for this branch can be viewed at https://sites.ecmwf.int/docs/loki/422/index.html

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.06%. Comparing base (899f5ac) to head (6aaeeb3).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #422      +/-   ##
==========================================
+ Coverage   93.04%   93.06%   +0.01%     
==========================================
  Files         198      198              
  Lines       39320    39353      +33     
==========================================
+ Hits        36587    36622      +35     
+ Misses       2733     2731       -2     

Flag	Coverage Δ
lint_rules	96.39% <ø> (ø)
loki	93.01% <100.00%> (+0.01%)	⬆️

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[reuterbal]

Thanks, this looks good to me. I've left two remarks how to improve the implementation a little bit but that's not mandatory. I'll leave it up to you whether you want to give this a try.

[reuterbal]

We might want to use the API properties of Interface here:

Suggested change

	for b in i.body:
	if isinstance(b, Subroutine):
	if targets and b.name.lower() in targets:
	# Create a new module import with explicitly qualified symbol
	modname = f'{b.name}_FC_MOD'
	new_symbol = Variable(name=f'{b.name}_FC', scope=routine)
	new_import = Import(module=modname, c_import=False, symbols=(new_symbol,))
	routine.spec.prepend(new_import)
	# Mark current import for removal
	removal_map[i] = None
	for s in i.symbols:
	if targets and s in targets:
	# Create a new module import with explicitly qualified symbol
	new_symbol = s.clone(name=f'{s.name}_FC', scope=routine)
	modname = f'{new_symbol.name}_MOD'
	new_import = Import(module=modname, c_import=False, symbols=(new_symbol,))
	routine.spec.prepend(new_import)
	# Mark current import for removal
	removal_map[i] = None

[reuterbal]

You might want to verify here also the name of the imported symbol.

Suggested improvement that uses more API functions:

Suggested change

	interfaces = FindNodes(ir.Interface).visit(routine.spec)
	imports = FindNodes(ir.Import).visit(routine.spec)
	assert len(interfaces) == 2
	assert len(imports) == 1
	assert imports[0].module.upper() == 'KERNEL_FC_MOD'
	assert len(routine.interfaces) == 2
	imports = routine.imports
	assert len(imports) == 1
	assert imports[0].module.upper() == 'KERNEL_FC_MOD'
	assert imports[0].symbols == ('KERNEL_FC',)