arrays verilog system-verilog verilator vpi

Reading parameter array through VPI

I have a integer parameter array like:

parameter integer PAR_ARR [3:0] = '{ 12, 34, 56, 78 }

I want to read the values of the parameter array through VPI.

Here is what I've observed: vpi_get(vpiType, par_handle) returns vpiParameter vpi_get_str(vpiDecompile, vpi_handle(vpiTypespec,par_handle)) returns integer array [3:0] vpi_get_str(vpiType, vpi_handle(vpiTypespec,par_handle)) returns vpiArrayTypespec vpi_get_str(vpiType, vpi_handle(vpiElemTypespec,vpi_handle(vpiTypespec,par_handle))) returns vpiIntegerTypespec

So I am assuming this needs to be iterated over to get the individual integer values

s_vpi_value val = {vpiDecStrVal};
vpiHandle arrayIterator = vpi_iterate(vpiIntegerVar, par_handle);
if( arrayIterator != NULL ) {
    vpiHandle item = NULL;
    while( NULL != ( item = vpi_scan( arrayIterator ) ) ) {
        vpi_get_value(item, &val);
        vpi_printf("item type: %s = %s\n", vpi_get_str(vpiType, item), val.value.str);
        vpi_free_object( item );
    }
}

However arrayIterator returns NULL and I never enter the while loop. This same method seems to work on reg arrays but not on parameter arrays.

What am I be doing wrong here? Or does VPI not support iterating over parameter arrays? If so, is there any alternative to access the parameter value via VPI?

Solution

verilog/system verilog standard does not provide a vpi way to access members of parameter arrays. The only way I am aware of is to get data for every array element separately. Here is an example:

#include "vpi_user.h"

void dumpArray() {
    vpiHandle module = vpi_handle_by_name("test", 0);

    char name[16];
    for (int i = 0; i < 4; i++) {
        strcpy(name, "PAR_ARR[");
        char num[16];
        sprintf(num, "%d", i);
        strcat(name, num);
        strcat(name, "]");
        
        vpiHandle pHandle = vpi_handle_by_name(name, module);
        s_vpi_value value = {vpiIntVal};
        vpi_get_value(pHandle, &value);
        vpi_printf("%s: %d\n", name, value.value.integer);
    }
}

module test;
   parameter integer PAR_ARR [3:0] = '{ 12, 34, 56, 78 };

   import "DPI-C" function void dumpArray();

   initial begin
      for (int i = 0; i <  4; i++) 
        $display("[%0d] --> %0d", i, PAR_ARR[i]);
      
      dumpArray();
   end
  
endmodule // test