Passing queue of structs by ref

SystemVerilog
1

I have a task that takes in a queue of structs as ref.
File1 has:

  1. struct defined
  2. queue of struct declared and initialized
  3. task definition

File2(which reads file 1)

  1. Has a struct and queue declaration (exactly the same as file1)
  2. calling the task method
//file1
 typedef struct {
                     string field_name;
                     int addr;
                     int value;
                  } s_cdt_info_t;
     
 typedef s_cdt_info_t creg_arr[$];
 creg_arr  sn_creg_arr;

  task get_creg_fields(string sw_type, ref creg_arr sn_creg_arr);

      case(sw_type)

         "A" : sbn_creg_arr = asn_sbn_cdt_struct_q;
         ..
         default ..;
      endcase
   endtask : get_creg_fields
//----------------------------------------------------------------------//
//FILE2
typedef struct {
                     string field_name;
                     int addr;
                     int value;
                  } base_cdt_info_t;

base_cdt_info_t  abn_cdt_struct_q[$];

//calling the task
file1.get_creg_fields("A", abn_cdt_struct_q);

Error#1: the formal and actual arguments don’t match

to resolve Error#1, I tried $cast(struct_file1, struct_file2)
but that failed too as some unclear verilog syntax err

Maybe I am wrong on many levels… but need some initial thoughts to begin with…

2

You have two unpacked struct declarations. It does not matter that they have the same field layout—they are not assignment compatible. And because at least one of the fields is a string type, you cannot do a bit-stream cast between them.

Unpacked structs variables are only assignment compatible if they share the same single typedef. You need to put the struct typedef in a common package and import the package in both places you use the struct.

See SystemVerilog Coding Guidelines: Package import versus `include - Verification Horizons

Also, I suggest using a function void instead of a task unless your routine needs to consume time. And use an output instead of a ref argument. See Passing arguments by reference

3

thanks for the info, Dave.
The common package is an option for me but wanted to have more knowledge about the failure which you gave me. And yes, I do have time consuming element and that’s why I am using task over func.