Add +timescale to the command file.

This patch adds a +timescale command to the command file
syntax that can be used to set the default time scale of
the simulation.

driver/cflexor.lex

@@ -72,19 +72,21 @@ int cmdfile_stack_ptr = 0;
 \n { cflloc.first_line += 1; }
 
 
-"+parameter+" { BEGIN(PLUS_ARGS); return TOK_PARAMETER; }
-
 "+define+" { BEGIN(PLUS_ARGS); return TOK_DEFINE; }
 
 "+incdir+" { BEGIN(PLUS_ARGS); return TOK_INCDIR; }
 
+"+integer-width+" { BEGIN(PLUS_ARGS); return TOK_INTEGER_WIDTH; }
+
 "+libdir+" { BEGIN(PLUS_ARGS); return TOK_LIBDIR; }
 
 "+libdir-nocase+" { BEGIN(PLUS_ARGS); return TOK_LIBDIR_NOCASE; }
 
 "+libext+" { BEGIN(PLUS_ARGS); return TOK_LIBEXT; }
 
-"+integer-width+" { BEGIN(PLUS_ARGS); return TOK_INTEGER_WIDTH; }
+"+parameter+" { BEGIN(PLUS_ARGS); return TOK_PARAMETER; }
+
+"+timescale+" { BEGIN(PLUS_ARGS); return TOK_TIMESCALE; }
 
   /* If it is not any known plus-flag, return the generic form. */
 "+"[^\n \t\b\f\r+]* {

driver/cfparse.y

@@ -57,8 +57,8 @@ static void translate_file_name(char*text)
 };
 
 %token TOK_Da TOK_Dc TOK_Dv TOK_Dy
-%token TOK_DEFINE TOK_INCDIR TOK_LIBDIR TOK_LIBDIR_NOCASE TOK_LIBEXT TOK_PARAMETER
+%token TOK_DEFINE TOK_INCDIR TOK_INTEGER_WIDTH TOK_LIBDIR TOK_LIBDIR_NOCASE
-%token TOK_INTEGER_WIDTH
+%token TOK_LIBEXT TOK_PARAMETER TOK_TIMESCALE
 %token <text> TOK_PLUSARG TOK_PLUSWORD TOK_STRING
 
 %%
@@ -142,6 +142,15 @@ item
 		  free(tmp);
 		}
 
+  /* The +timescale token is used to set the default timescale for
+     the simulator. */
+        | TOK_TIMESCALE TOK_PLUSARG
+                { char*tmp = substitutions($2);
+		  process_timescale(tmp);
+		  free($2);
+		  free(tmp);
+		}
+
 	| TOK_DEFINE TOK_PLUSARG
 		{ process_define($2);
 		  free($2);

driver/globals.h

@@ -43,5 +43,8 @@ extern void process_define(const char*name);
  
   /* Add a new parameter definition */
 extern void process_parameter(const char*name);
+ 
+  /* Set the default timescale for the simulator. */
+extern void process_timescale(const char*ts_string);
 
 #endif

driver/iverilog.man.in

@@ -1,4 +1,4 @@
-.TH iverilog 1 "October 28th, 2009" "" "Version %M.%m.%n %E"
+.TH iverilog 1 "December 29th, 2009" "" "Version %M.%m.%n %E"
 .SH NAME
 iverilog - Icarus Verilog compiler
 
@@ -425,9 +425,16 @@ command line. The value part of the token is optional.
 
 .TP 8
 .B +parameter+\fINAME\fP=\fIvalue\fP
-The \fB+default+\fP token is the same as the \fB\-P\fP option on the
+The \fB+parameter+\fP token is the same as the \fB\-P\fP option on the
 command line.
 
+.TP 8
+.B +timescale+\fIvalue\fP
+The \fB+timescale+\fP token is used to set the default timescale for
+the simulation. This is the time units and precision before any
+`timescale directive or after a `resetall directive. The default is
+1s/1s.
+
 .TP 8
 .B +toupper-filename
 This token causes file names after this in the command file to be

driver/main.c

@@ -582,6 +582,11 @@ void process_parameter(const char*name)
       fprintf(iconfig_file,"defparam:%s\n", name);
 }
 
+void process_timescale(const char*ts_string)
+{
+      fprintf(iconfig_file, "timescale:%s\n", ts_string);
+}
+
 /*
  * This function is called while processing a file name in a command
  * file, or a file name on the command line. Look to see if there is a

main.cc

@@ -312,6 +312,127 @@ static void parm_to_flagmap(const string&flag)
 static void find_module_mention(map<perm_string,bool>&check_map, Module*m);
 static void find_module_mention(map<perm_string,bool>&check_map, PGenerate*s);
 
+/*
+ * Convert a string to a time unit or precision.
+ *
+ * Returns true on failure.
+ */
+static bool get_ts_const(const char*&cp, int&res, bool is_units)
+{
+	/* Check for the 1 digit. */
+      if (*cp != '1') {
+	    if (is_units) {
+		  cerr << "Error: Invalid +timescale units constant "
+		          "(1st digit)." << endl;
+	    } else {
+		  cerr << "Error: Invalid +timescale precision constant "
+		          "(1st digit)." << endl;
+	    }
+	    return true;
+      }
+      cp += 1;
+
+	/* Check the number of zeros after the 1. */
+      res = strspn(cp, "0");
+      if (res > 2) {
+	    if (is_units) {
+		  cerr << "Error: Invalid +timescale units constant "
+		          "(number of zeros)." << endl;
+	    } else {
+		  cerr << "Error: Invalid +timescale precision constant "
+		          "(number of zeros)." << endl;
+	    }
+	    return true;
+      }
+      cp += res;
+
+	/* Now process the scaling string. */
+      if (strncmp("s", cp, 1) == 0) {
+	    res -= 0;
+	    cp += 1;
+	    return false;
+
+      } else if (strncmp("ms", cp, 2) == 0) {
+	    res -= 3;
+	    cp += 2;
+	    return false;
+
+      } else if (strncmp("us", cp, 2) == 0) {
+	    res -= 6;
+	    cp += 2;
+	    return false;
+
+      } else if (strncmp("ns", cp, 2) == 0) {
+	    res -= 9;
+	    cp += 2;
+	    return false;
+
+      } else if (strncmp("ps", cp, 2) == 0) {
+	    res -= 12;
+	    cp += 2;
+	    return false;
+
+      } else if (strncmp("fs", cp, 2) == 0) {
+	    res -= 15;
+	    cp += 2;
+	    return false;
+
+      }
+
+      if (is_units) {
+	    cerr << "Error: Invalid +timescale units scale." << endl;
+      } else {
+	    cerr << "Error: Invalid +timescale precision scale." << endl;
+      }
+      return true;
+}
+
+/*
+ * Process a string with the following form (no space allowed):
+ *
+ *   num = < '1' | '10' | '100' >
+ *   scale = < 's' | 'ms' | 'us' | 'ns' | 'ps' | 'fs' >
+ *
+ *   "<num> <scale> '/' <num> <scale>
+ *
+ * and set the default time units and precision if successful.
+ *
+ * Return true if we have an error processing the timescale string.
+ */
+static bool set_default_timescale(const char*ts_string)
+{
+	/* Because this came from a command file we can not have embedded
+	 * space in this string. */
+      const char*cp = ts_string;
+      int units = 0;
+      int prec = 0;
+
+	/* Get the time units. */
+      if (get_ts_const(cp, units, true)) return true;
+
+	/* Skip the '/'. */
+      if (*cp != '/') {
+	    cerr << "Error: +timescale separator '/' is missing." << endl;
+	    return true;
+      }
+      cp += 1;
+
+	/* Get the time precision. */
+      if (get_ts_const(cp, prec, false)) return true;
+
+	/* The time unit must be greater than or equal to the precision. */
+      if (units < prec) {
+	    cerr << "Error: +timescale unit must not be less than the "
+	            "precision." << endl;
+	    return true;
+      }
+
+	/* We have valid units and precision so set the global defaults. */
+      def_ts_units = units;
+      def_ts_prec = prec;
+      return false;
+}
+
 /*
  * Read the contents of a config file. This file is a temporary
  * configuration file made by the compiler driver to carry the bulky
@@ -384,6 +505,7 @@ static void find_module_mention(map<perm_string,bool>&check_map, PGenerate*s);
  *    warnings:<string>
  *        Warning flag letters.
  */
+bool had_timescale = false;
 static void read_iconfig_file(const char*ipath)
 {
       char buf[8*1024];
@@ -560,8 +682,19 @@ static void read_iconfig_file(const char*ipath)
 			flag_errors += 1;
 		  }
 	    } else if (strcmp(buf,"defparam") == 0) {
-            parm_to_defparam_list(cp);
+		  parm_to_defparam_list(cp);
-        }
+	    } else if (strcmp(buf,"timescale") == 0) {
+		  if (had_timescale) {
+			cerr << "Command File: Warning: default timescale "
+			        "is being set multiple times." << endl;
+			cerr << "                     : using the last valid "
+			        "+timescale found." << endl;
+		  }
+		  if (set_default_timescale(cp)) {
+			cerr << "     : with +timescale+" << cp << "+" << endl;
+			flag_errors += 1;
+		  } else had_timescale = true;
+	    }
       }
       fclose(ifile);
 }