Factor out common code for warning about inconsistent timescales.

Also reword the warning for SystemVerilog, where `timescale is not
the only (or indeed preferred) way of specifying timescales.

(cherry picked from commit 9382d22063)

PDelays.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2011 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1999-2017 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -26,11 +26,6 @@
 # include  "verinum.h"
 # include  "netmisc.h"
 
-bool dly_used_no_timescale = false;
-bool dly_used_timescale = false;
-bool display_ts_dly_warning = true;
-
-
 PDelays::PDelays()
 {
       delete_flag_ = true;
@@ -80,19 +75,7 @@ static NetExpr*calculate_val(Design*des, NetScope*scope, PExpr*expr)
 {
       NetExpr*dex = elab_and_eval(des, scope, expr, -1);
 
-	/* Print a warning if we find default and `timescale based
+      check_for_inconsistent_delays(scope);
-	 * delays in the design, since this is likely an error. */
-      if (scope->time_from_timescale()) dly_used_timescale = true;
-      else dly_used_no_timescale = true;
-
-      if (display_ts_dly_warning &&
-          dly_used_no_timescale && dly_used_timescale) {
-	    cerr << "warning: Found both default and "
-	            "`timescale based delays. Use" << endl;
-	    cerr << "         -Wtimescale to find the "
-	            "module(s) with no `timescale." << endl;
-	    display_ts_dly_warning = false;
-      }
 
 	/* If the delay expression is a real constant or vector
 	   constant, then evaluate it, scale it to the local time

elaborate.cc

@@ -2374,19 +2374,7 @@ static NetExpr*elaborate_delay_expr(PExpr*expr, Design*des, NetScope*scope)
 {
       NetExpr*dex = elab_and_eval(des, scope, expr, -1);
 
-	/* Print a warning if we find default and `timescale based
+      check_for_inconsistent_delays(scope);
-	 * delays in the design, since this is likely an error. */
-      if (scope->time_from_timescale()) dly_used_timescale = true;
-      else dly_used_no_timescale = true;
-
-      if (display_ts_dly_warning &&
-          dly_used_no_timescale && dly_used_timescale) {
-	    cerr << "warning: Found both default and "
-	            "`timescale based delays. Use" << endl;
-	    cerr << "         -Wtimescale to find the "
-	            "module(s) with no `timescale." << endl;
-	    display_ts_dly_warning = false;
-      }
 
 	/* If the delay expression is a real constant or vector
 	   constant, then evaluate it, scale it to the local time
@@ -5434,19 +5422,7 @@ void PSpecPath::elaborate(Design*des, NetScope*scope) const
       ndelays = delays.size();
       if (ndelays > 12) ndelays = 12;
 
-	/* Print a warning if we find default and `timescale based
+      check_for_inconsistent_delays(scope);
-	 * delays in the design, since this is likely an error. */
-      if (scope->time_from_timescale()) dly_used_timescale = true;
-      else dly_used_no_timescale = true;
-
-      if (display_ts_dly_warning &&
-          dly_used_no_timescale && dly_used_timescale) {
-	    cerr << "warning: Found both default and "
-	            "`timescale based delays. Use" << endl;
-	    cerr << "         -Wtimescale to find the "
-	            "module(s) with no `timescale." << endl;
-	    display_ts_dly_warning = false;
-      }
 
 	/* Elaborate the delay values themselves. Remember to scale
 	   them for the timescale/precision of the scope. */

netmisc.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001-2016 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2017 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -1665,3 +1665,38 @@ NetScope* find_method_containing_scope(const LineInfo&, NetScope*scope)
 
       return scope;
 }
+
+
+/*
+ * Print a warning if we find a mixture of default and explicit timescale
+ * based delays in the design, since this is likely an error.
+ */
+void check_for_inconsistent_delays(NetScope*scope)
+{
+      static bool used_implicit_timescale = false;
+      static bool used_explicit_timescale = false;
+      static bool display_ts_dly_warning = true;
+
+      if (scope->time_from_timescale())
+	    used_explicit_timescale = true;
+      else
+	    used_implicit_timescale = true;
+
+      if (display_ts_dly_warning &&
+	  used_explicit_timescale &&
+	  used_implicit_timescale) {
+	    if (gn_system_verilog()) {
+		  cerr << "warning: Found both default and explicit "
+			  "timescale based delays. Use" << endl;
+		  cerr << "       : -Wtimescale to find the design "
+			  "element(s) with no explicit" << endl;
+		  cerr << "       : timescale." << endl;
+	    } else {
+		  cerr << "warning: Found both default and "
+			  "`timescale based delays. Use" << endl;
+		  cerr << "       : -Wtimescale to find the "
+			  "module(s) with no `timescale." << endl;
+	    }
+	    display_ts_dly_warning = false;
+      }
+}

netmisc.h

@@ -1,7 +1,7 @@
 #ifndef IVL_netmisc_H
 #define IVL_netmisc_H
 /*
- * Copyright (c) 1999-2016 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1999-2017 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -378,10 +378,6 @@ const char *human_readable_op(const char op, bool unary = false);
 enum const_bool { C_NON, C_0, C_1, C_X };
 const_bool const_logical(const NetExpr*expr);
 
-extern bool dly_used_no_timescale;
-extern bool dly_used_timescale;
-extern bool display_ts_dly_warning;
-
 /*
  * When scaling a real value to a time we need to do some standard
  * processing.
@@ -409,4 +405,10 @@ extern void assign_unpacked_with_bufz(Design*des, NetScope*scope,
 
 extern NetPartSelect* detect_partselect_lval(Link&pin);
 
+/*
+ * Print a warning if we find a mixture of default and explicit timescale
+ * based delays in the design, since this is likely an error.
+ */
+extern void check_for_inconsistent_delays(NetScope*scope);
+
 #endif /* IVL_netmisc_H */