verilator/test_regress/t/t_lint_unused_bad.v

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed into the Public Domain, for any use,
// without warranty, 2010 by Wilson Snyder.

module t (/*AUTOARG*/
   // Outputs
   out,
   // Inputs
   in
   );

   input in;  // inputs don't get flagged as undriven
   output out;  // outputs don't get flagged as unused

   sub sub ();

   // Check we don't warn about unused UDP signals
   udp_mux2 udpsub (out, in, in, in);

   // Check ignoreds mark as used
   reg 	  sysused;
   initial $bboxed(sysused);

   wire   _unused_ok;

endmodule

module sub;

   wire pub /*verilator public*/;   // Ignore publics

   wire [5:0] assunu1 = 0;  // Assigned but unused

   wire [3:0] assunub2 = 0;  // Assigned but bit 2 unused

   wire [15:10] udrb2;  // [14:13,11] is undriven
   assign udrb2[15] = 0;
   assign udrb2[12] = 0;
   assign udrb2[10] = 0;
   
   wire       unu3;  // Totally unused

   wire [3:0] mixed;  // [3] unused & undr, [2] unused, [1] undr, [0] ok
   assign mixed[2] = 0;
   assign mixed[0] = 0;

   localparam THREE = 3;

   initial begin
      if (0 && assunu1[0] != 0 && udrb2 != 0) begin end
      if (0 && assunub2[THREE] && assunub2[1:0]!=0) begin end
      if (0 && mixed[1:0] != 0) begin end
   end
endmodule

primitive udp_mux2 (q, a, b, s);
   output q;
   input  a, b, s;
   table
      //a b  s  :  out
      1   ?  0  :  1 ;
      0   ?  0  :  0 ;
      ?   1  1  :  1 ;
      ?   0  1  :  0 ;
      0   0  x  :  0 ;
      1   1  x  :  1 ;
   endtable
endprimitive