NVC Simulation Error

[David]

Hello Jim,

I’m not sure if this is an OSVVM issue, a QuestaSim issue or an NVC issue, could you help me identify where/if this should be raised please? or if my VHDL is wrong that is using OSVVM.

This code runs successfully in Questa but gives an error when run in NVC:

** Error: type of index BOOLEAN does not match type of array dimension POSITIVE
Error: > ../../../../00_Test_Libaries/generic_tb_components/output_checker_sl.vhd:658
Error: |
Error: 658 | Log(checker_rst_alert_id, get_component_name(TRUE) & “reset checks enabled”, INFO);
Error: | ^^^^

Not this is with an older release of OSVVM:
source ….ripts/StartNVC.tcl
OSVVM Script Version: 2023.07
Simulator Version: nvc-1.19.2

Any help appreciated,
Regards,
Dave

[Jim Lewis]

Hi Dave,
Is get_component_name a function that has an optional boolean parameter and returns type string?
It would help to see its definition, however, I will make some guesses.

I have seen this issue before when the optional parameter is type integer, but never with type boolean.
With type integer, in this context, it is correct if “get_component_name(1)” returns either a string
or a character value. If the 1 is seen as the optional parameter, the function returns a string
value. If the 1 is not seen as the optional parameter, then the 1 is indexing the string
return value and the expression results in a character value. Some tools will report this as
an ambiguous expression – some will not see the index and will not report it.
For me, the LRM is complex in this area and I am not clear about the proper interpretation.

The error is valid if TRUE is not a valid parameter of get_component_name. In which case NVC is
trying to use the TRUE to index a string and hence the message.

OTOH, if TRUE is a parameter (optional or not) of get_component_name, it looks like NVC has a
bug and you should report it at https://github.com/nickg/nvc/issues. Nick is generally quick
about responding – and explaining why he thinks the message is correct or it is a bug.

Best Regards,
Jim

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