Fix fault on with %t, bug1443.

Changes

@@ -8,9 +8,11 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Support VerilatedFstC set_time_unit, bug1433. [Pieter Kapsenberg]
 
+****  Mark infrequently called functions with GCC cold attribute.
+
 ****  Fix sign-compare warning in verilated.cpp, bug1437. [Sergey Kvachonok]
 
-****  Mark infrequently called functions with GCC cold attribute.
+****  Fix fault on $realtime with %t, bug1443. [Julien Margetts]
 
 
 * Verilator 4.014 2019-05-08

include/verilated.cpp

@@ -642,14 +642,28 @@ void _vl_vsformat(std::string& output, const char* formatp, va_list ap) VL_MT_SA
             }
             case 'e':
             case 'f':
-            case 'g': {
+            case 'g':
+            case '^': {  // Realtime
                 const int lbits = va_arg(ap, int);
                 double d = va_arg(ap, double);
                 if (lbits) {}  // UNUSED - always 64
-                strncpy(tmpf, pctp, pos-pctp+1);
-                tmpf[pos-pctp+1] = '\0';
-                sprintf(tmp, tmpf, d);
-                output += tmp;
+                switch (fmt) {
+                case '^': {  // Realtime
+                    int digits = sprintf(tmp, "%g", d/VL_TIME_MULTIPLIER);
+                    int needmore = width-digits;
+                    if (needmore>0) output.append(needmore, ' ');  // Pre-pad spaces
+                    output += tmp;
+                    break;
+                }
+                default: {
+                    strncpy(tmpf, pctp, pos-pctp+1);
+                    tmpf[pos-pctp+1] = '\0';
+                    sprintf(tmp, tmpf, d);
+                    output += tmp;
+                    break;
+                }
+                break;
+                }  // switch
                 break;
             }
             default: {

src/V3EmitC.cpp

@@ -1638,8 +1638,9 @@ void EmitCStmts::displayNode(AstNode* nodep, AstScopeName* scopenamep,
 	    case 's': displayArg(nodep,&elistp,isScan, vfmt,'s'); break;
 	    case 'e': displayArg(nodep,&elistp,isScan, vfmt,'e'); break;
 	    case 'f': displayArg(nodep,&elistp,isScan, vfmt,'f'); break;
-	    case 'g': displayArg(nodep,&elistp,isScan, vfmt,'g'); break;
-	    case 'v': displayArg(nodep,&elistp,isScan, vfmt,'v'); break;
+            case 'g': displayArg(nodep,&elistp,isScan, vfmt,'g'); break;
+            case '^': displayArg(nodep,&elistp,isScan, vfmt,'^'); break;  // Realtime
+            case 'v': displayArg(nodep,&elistp,isScan, vfmt,'v'); break;
 	    case 'm': {
 		if (!scopenamep) nodep->v3fatalSrc("Display with %m but no AstScopeName");
 		string suffix = scopenamep->scopePrettySymName();

src/V3Number.cpp

@@ -582,8 +582,9 @@ string V3Number::displayed(FileLine*fl, const string& vformat) const {
     }
     case 'e':
     case 'f':
-    case 'g': {
-	char tmp[MAX_SPRINTF_DOUBLE_SIZE];
+    case 'g':
+    case '^': {  // Realtime
+        char tmp[MAX_SPRINTF_DOUBLE_SIZE];
 	sprintf(tmp, vformat.c_str(), toDouble());
 	return tmp;
     }

src/V3Width.cpp

@@ -2172,6 +2172,13 @@ private:
 		    if (argp) argp=argp->nextp();
 		    break;
 		}
+                case 't': {  // Convert decimal time to realtime
+                    if (argp && argp->isDouble()) {  // Convert it
+                        ch = '^';
+                    }
+                    if (argp) argp = argp->nextp();
+                    break;
+                }
 		default: {  // Most operators, just move to next argument
 		    if (argp) argp=argp->nextp();
 		    break;

test_regress/t/t_display_realtime.pl

@@ -0,0 +1,21 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(simulator => 1);
+
+compile(
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+
+1;

test_regress/t/t_display_realtime.v

@@ -0,0 +1,22 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by Wilson Snyder.
+
+module t (/*AUTOARG*/
+   // Inputs
+   clk
+   );
+   input clk;
+
+   integer      cyc=0;
+
+   always @ (posedge clk) begin
+      cyc <= cyc + 1;
+      $display("TestCase at %1t (%s)", $realtime, cyc[0] ? "Option1" : "Option2");
+      if (cyc==9) begin
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+   end
+endmodule