Any way to pass enum values by name as commandline args? - system-verilog

Question

Is there any way to pass the value of an enum by name from the commandline? Rather what's the cleanest solution?
I tried the below,
typedef enum int unsigned { white, black, red } colour_e;
class house;
rand colour_e colour;
string n_colour = "white";
constraint c_colour {
colour.name() == n_colour;
}
endclass: house
program top;
house paradise;
initial begin
paradise = new();
void'($value$plusargs("colour=%0s", paradise.n_colour));
if (!paradise.randomize())
$display("not randomized");
else
$display("paradise.colour = %s",paradise.colour);
end
endprogram: top
I would want to pass something like this +colour=black. so that the paradise.colour is assigned black.
vcs cribbed for using enum.name() in the constraints.
below is the error.
Error-[NYI-CSTR-SYS-FTC] NYI constraint: sys function calls
T-enum_1.sv, 9 $unit, "this.colour.name" System function calls are
not yet implemented in constraints. Remove the function call or if
possible replace it with an integral state variable assigned in
pre_randomize().
while Riviera cried as below
ERROR VCP7734 "Type of 'this.colour.name()' is not allowed in a
constraint block. Only integral types are allowed in a constraint
block." "design.sv" 9 1 ERROR VCP7734 "Type of 'n_colour' is not
allowed in a constraint block. Only integral types are allowed in a
constraint block." "design.sv" 9 1 WARNING VCP7114 "STRING value
expected for format specifier %s as parameter
paradise.colour." "testbench.sv" 13 54
which brings the question to me, does everything in the contraint block has to be of integral type (just like we cannot declare a string as rand variable)?
ANyone wants to play around the code please have a look at the code at EDA playground here

Answer 1

Use uvm_enum_wrapper class to do the conversion from string to corresponding enum value. It is a template class wrapper defined in uvm_globals.svh (part of UVM 1.2) and you can use it as follows:
typedef enum {white, black, red} colour_e;
typedef uvm_enum_wrapper#(colour_e) colour_wrapper;
string colour_str;
void'($value$plusargs("colour=%0s", colour_str));
colour_wrapper::from_name(colour_str, paradize.n_colour);
The wrapper class uvm_enum_wrapper works by traversing the enum entries and creating an assoc array for a enum[string] map for the given enum type (supplied as template parameter). For more details take a look at the documentation.

Answer 2

There is another solution for the same. If you are not using UVM 1.2 version then there is like you can take string as an input argument and convert that string argument into int type. After that you can directly cast int to enum type by $cast.
Because there is no way to convert string to enum type (except UVM 1.2) so you have to add one extra step for the same.
module Test;
typedef enum {black,red,blue} color_e; //enum declaration
color_e color; //type of enum
string cmd_str; //Commandline string input
int cmd_int; //Input string is first converted into int
initial
begin
$value$plusargs("enum_c=%0s",cmd_str); //Take input argument as string it may be 0,1 or 2
cmd_int=cmd_str.atoi(); //Now convert that string argument into int type
$cast(color,cmd_int); //Casting int to enum type
$display("Value of color is --> %p",color); //Display value of enum
end
endmodule