Verilator

It looks like there is a related problem: localparam defined inside package cannot be used in function defined inside the same package:

package functions;
        localparam MAX_STRING_LENGTH = 20;

        function [8*3:1] get_time_unit;
                input [8*MAX_STRING_LENGTH:1] time_string;

                integer index;
                reg [8*3:1] time_unit;

                begin
                        index = 0;
                        time_unit = "";

                        for (index = 1; index <= MAX_STRING_LENGTH; index = index + 1)
...
                        get_time_unit = time_unit;
                end
        endfunction
...
        function integer is_period;
                input [8*MAX_STRING_LENGTH:1] time_string;
...
endpackage

module generic_a
#(
...
        parameter output_clock_frequency = "0 ps",
...
) (
        input wire          refclk,
        input wire          rst,
...
);
        import functions::*;
localparam output_clock_as_period = is_period(output_clock_frequency);
...

I get 2 errors:

%Error: ...: Expecting expression to be constant, but can't determine constant for FUNCREF 'is_period'
%Error: ...: ... Location of non-constant VARREF 'MAX_STRING_LENGTH': Language violation: reference to non-function-local variable

The first is on localparam output_clock_as_period = is_period(

The second is on for (index = 1; index <= MAX_STRING_LENGTH; index = index + 1)

Another example:

package verbosity_pkg;

   typedef enum int {VERBOSITY_NONE, 
             VERBOSITY_FAILURE, 
             VERBOSITY_ERROR, 
             VERBOSITY_WARNING, 
             VERBOSITY_INFO,
             VERBOSITY_DEBUG} Verbosity_t;

   Verbosity_t  verbosity = VERBOSITY_INFO;
   string     message = "";
...
endpackage

module a_clock_source (clk);
   output clk;

   parameter CLOCK_RATE = 10;  // clock rate in MHz

// synthesis translate_off
   import verbosity_pkg::*;

   localparam HALF_CLOCK_PERIOD   = 1000.000000/CLOCK_RATE/2; // half clock period in ns

   logic clk = 1'b0;

   string message   = "*uninitialized*";
...

verilator error:

%Error: Internal Error: ...: ../V3SymTable.h:60: Inserting two symbols with same name: message

Was this issue really fixed?

Changes file says about different issue:

Fix parameters not supported in constant functions, bug474. [Alex Solomatnikov]