diff --git a/Module.cc b/Module.cc
index d880c0009..e608a6401 100644
--- a/Module.cc
+++ b/Module.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998-2008 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2009 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
@@ -29,7 +29,9 @@ Module::Module(perm_string n)
 : PScope(n)
 {
       library_flag = false;
+      is_cell = false;
       default_nettype = NetNet::NONE;
+      timescale_warn_done = false;
 }
 
 Module::~Module()
diff --git a/Module.h b/Module.h
index f5fb524fd..a2960bc74 100644
--- a/Module.h
+++ b/Module.h
@@ -74,6 +74,8 @@ class Module : public PScope, public LineInfo {
 	   other effect. */
       bool library_flag;
 
+      bool is_cell;
+
       NetNet::Type default_nettype;
 
 	/* specparams are simpler then other params, in that they have
@@ -106,6 +108,7 @@ class Module : public PScope, public LineInfo {
 	   set by the `timescale directive. */
       int time_unit, time_precision;
       bool time_from_timescale;
+      bool timescale_warn_done;
 
 	/* Task definitions within this module */
       map<perm_string,PTask*> tasks;
diff --git a/design_dump.cc b/design_dump.cc
index cf54cfb0d..30a98325b 100644
--- a/design_dump.cc
+++ b/design_dump.cc
@@ -1081,6 +1081,7 @@ void NetScope::dump(ostream&o) const
 
       print_type(o);
       if (is_auto()) o << " (automatic)";
+      if (is_cell()) o << " (cell)";
       o << endl;
 
       for (unsigned idx = 0 ;  idx < attr_cnt() ;  idx += 1)
diff --git a/driver/cflexor.lex b/driver/cflexor.lex
index dd35c1fa2..526f8eaed 100644
--- a/driver/cflexor.lex
+++ b/driver/cflexor.lex
@@ -4,7 +4,7 @@
 
 %{
 /*
- * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 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
@@ -21,9 +21,6 @@
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
-#ifdef HAVE_CVS_IDENT
-#ident "$Id: cflexor.lex,v 1.11 2007/03/22 16:08:18 steve Exp $"
-#endif
 
 # include  "cfparse.h"
 # include  "cfparse_misc.h"
@@ -236,3 +233,17 @@ void cfreset(FILE*fd, const char*path)
       current_file = strdup(path);
       cflloc.first_line = 1;
 }
+
+/*
+ * Modern version of flex (>=2.5.9) can clean up the scanner data.
+ */
+void destroy_lexor()
+{
+# ifdef FLEX_SCANNER
+#   if YY_FLEX_MAJOR_VERSION >= 2 && YY_FLEX_MINOR_VERSION >= 5
+#     if defined(YY_FLEX_SUBMINOR_VERSION) && YY_FLEX_SUBMINOR_VERSION >= 9
+    yylex_destroy();
+#     endif
+#   endif
+# endif
+}
diff --git a/driver/cfparse.y b/driver/cfparse.y
index 67d85db94..9ee38e7d3 100644
--- a/driver/cfparse.y
+++ b/driver/cfparse.y
@@ -1,6 +1,6 @@
 %{
 /*
- * Copyright (c) 20001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 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
@@ -17,10 +17,6 @@
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
-#ifdef HAVE_CVS_IDENT
-#ident "$Id: cfparse.y,v 1.12 2007/04/19 02:52:53 steve Exp $"
-#endif
-
 
 # include  "globals.h"
 # include  "cfparse_misc.h"
diff --git a/driver/cfparse_misc.h b/driver/cfparse_misc.h
index b822bd7a9..708d79f93 100644
--- a/driver/cfparse_misc.h
+++ b/driver/cfparse_misc.h
@@ -1,7 +1,7 @@
 #ifndef __cfparse_misc_H
 #define __cfparse_misc_H
 /*
- * Copyright (c) 2001 Picture Elements, Inc.
+ * Copyright (c) 2001-2009 Picture Elements, Inc.
  *    Stephen Williams (steve@picturel.com)
  *
  *    This source code is free software; you can redistribute it
@@ -38,6 +38,7 @@ int cflex(void);
 int cferror(const char *);
 int cfparse(void);
 void switch_to_command_file(const char *);
+void destroy_lexor();
 char *current_file;
 
 #endif
diff --git a/driver/main.c b/driver/main.c
index b97decf7a..66e451397 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -870,6 +870,20 @@ int main(int argc, char **argv)
 		  break;
 		case '?':
 		default:
+		  fclose(source_file);
+		  remove(source_path);
+		  free(source_path);
+		  fclose(defines_file);
+		  remove(defines_path);
+		  free(defines_path);
+		  fclose(iconfig_file);
+		  remove(iconfig_path);
+		  free(iconfig_path);
+		  remove(compiled_defines_path);
+		  free(compiled_defines_path);
+		  while( (command_filename = get_cmd_file()) ) {
+			free(command_filename);
+		  }
 		  return 1;
 	    }
       }
@@ -941,7 +955,9 @@ int main(int argc, char **argv)
 		  return 1;
 	    }
             free(command_filename);
+            fclose(fp);
       }
+      destroy_lexor();
 
       if (depfile) {
 	    fprintf(defines_file, "M:%s\n", depfile);
diff --git a/elab_scope.cc b/elab_scope.cc
index f9a20cf89..afc438573 100644
--- a/elab_scope.cc
+++ b/elab_scope.cc
@@ -479,6 +479,8 @@ bool Module::elaborate_scope(Design*des, NetScope*scope,
 
       elaborate_scope_events_(des, scope, events);
 
+      scope->is_cell(is_cell);
+
       return des->errors == 0;
 }
 
diff --git a/ivl.def b/ivl.def
index d57d9ad0d..c254c422a 100644
--- a/ivl.def
+++ b/ivl.def
@@ -161,6 +161,7 @@ ivl_scope_event
 ivl_scope_events
 ivl_scope_file
 ivl_scope_is_auto
+ivl_scope_is_cell
 ivl_scope_lineno
 ivl_scope_logs
 ivl_scope_log
diff --git a/ivl_target.h b/ivl_target.h
index 78723d155..8a2758a46 100644
--- a/ivl_target.h
+++ b/ivl_target.h
@@ -1537,6 +1537,9 @@ extern unsigned ivl_parameter_lineno(ivl_parameter_t net);
  * ivl_scope_is_auto
  *    Is the task or function declared to be automatic?
  *
+ * ivl_scope_is_cell
+ *    Is the module defined to be a cell?
+ *
  * ivl_scope_var
  * ivl_scope_vars
  *    REMOVED
@@ -1614,6 +1617,7 @@ extern unsigned     ivl_scope_events(ivl_scope_t net);
 extern ivl_event_t  ivl_scope_event(ivl_scope_t net, unsigned idx);
 extern const char* ivl_scope_file(ivl_scope_t net);
 extern unsigned ivl_scope_is_auto(ivl_scope_t net);
+extern unsigned ivl_scope_is_cell(ivl_scope_t net);
 extern unsigned ivl_scope_lineno(ivl_scope_t net);
 extern unsigned     ivl_scope_logs(ivl_scope_t net);
 extern ivl_net_logic_t ivl_scope_log(ivl_scope_t net, unsigned idx);
diff --git a/ivlpp/main.c b/ivlpp/main.c
index df9d1b811..1b3906c55 100644
--- a/ivlpp/main.c
+++ b/ivlpp/main.c
@@ -214,26 +214,34 @@ int main(int argc, char*argv[])
       FILE*precomp_out = NULL;
 
 	/* Define preprocessor keywords that I plan to just pass. */
+	/* From 1364-2005 Chapter 19. */
+      define_macro("begin_keywords",          "`begin_keywords", 1, 0);
       define_macro("celldefine",              "`celldefine", 1, 0);
-      define_macro("default_decay_time",      "`default_decay_time", 1, 0);
       define_macro("default_nettype",         "`default_nettype", 1, 0);
-      define_macro("default_trireg_strength", "`default_trireg_strength", 1, 0);
-      define_macro("delay_mode_distributed",  "`delay_mode_distributed", 1, 0);
-      define_macro("delay_mode_unit",         "`delay_mode_unit", 1, 0);
-      define_macro("delay_mode_path",         "`delay_mode_path", 1, 0);
-      define_macro("delay_mode_zero",         "`delay_mode_zero", 1, 0);
-      define_macro("disable_portfaults",      "`disable_portfaults", 1, 0);
-      define_macro("enable_portfaults",       "`enable_portfaults", 1, 0);
+      define_macro("end_keywords",            "`end_keywords", 1, 0);
       define_macro("endcelldefine",           "`endcelldefine", 1, 0);
-      define_macro("endprotect",              "`endprotect", 1, 0);
       define_macro("line",                    "`line", 1, 0);
-      define_macro("nosuppress_faults",       "`nosuppress_faults", 1, 0);
       define_macro("nounconnected_drive",     "`nounconnected_drive", 1, 0);
-      define_macro("protect",                 "`protect", 1, 0);
+      define_macro("pragma",                  "`pragma", 1, 0);
       define_macro("resetall",                "`resetall", 1, 0);
-      define_macro("suppress_faults",         "`suppress_faults", 1, 0);
       define_macro("timescale",               "`timescale", 1, 0);
       define_macro("unconnected_drive",       "`unconnected_drive", 1, 0);
+
+	/* From 1364-2005 Annex D. */
+      define_macro("default_decay_time",      "`default_decay_time", 1, 0);
+      define_macro("default_trireg_strength", "`default_trireg_strength", 1, 0);
+      define_macro("delay_mode_distributed",  "`delay_mode_distributed", 1, 0);
+      define_macro("delay_mode_path",         "`delay_mode_path", 1, 0);
+      define_macro("delay_mode_unit",         "`delay_mode_unit", 1, 0);
+      define_macro("delay_mode_zero",         "`delay_mode_zero", 1, 0);
+
+	/* From other places. */
+      define_macro("disable_portfaults",      "`disable_portfaults", 1, 0);
+      define_macro("enable_portfaults",       "`enable_portfaults", 1, 0);
+      define_macro("endprotect",              "`endprotect", 1, 0);
+      define_macro("nosuppress_faults",       "`nosuppress_faults", 1, 0);
+      define_macro("protect",                 "`protect", 1, 0);
+      define_macro("suppress_faults",         "`suppress_faults", 1, 0);
       define_macro("uselib",                  "`uselib", 1, 0);
 
       include_cnt = 2;
diff --git a/lexor.lex b/lexor.lex
index 447eaf813..ad0df6906 100644
--- a/lexor.lex
+++ b/lexor.lex
@@ -67,9 +67,6 @@ static const char* set_file_name(char*text)
       return path;
 }
 
-
-extern void pform_set_timescale(int, int, const char*file, unsigned line);
-
 void reset_lexor();
 static void line_directive();
 static void line_directive2();
@@ -88,6 +85,8 @@ static list<int> keyword_mask_stack;
 
 static int comment_enter;
 static bool in_module = false;
+static bool in_UDP = false;
+bool in_celldefine = false;
 %}
 
 %x CCOMMENT
@@ -107,8 +106,9 @@ S [afpnumkKMGT]
 
 %%
 
-^"#line"[ ]+\"[^\"]*\"[ ]+[0-9]+.* { line_directive(); }
-^"`line"[ ]+[0-9]+[ ]+\"[^\"]*\".* { line_directive2(); }
+  /* Recognize the various line directives. */
+^"#line"[ \t]+.+ { line_directive(); }
+^[ \t]?"`line"[ \t]+.+ { line_directive2(); }
 
 [ \t\b\f\r] { ; }
 \n { yylloc.first_line += 1; }
@@ -237,6 +237,14 @@ S [afpnumkKMGT]
 	    in_module = false;
 	    break;
 
+	  case K_primitive:
+	    in_UDP = true;
+	    break;
+
+	  case K_endprimitive:
+	    in_UDP = false;
+	    break;
+
 	  default:
 	    yylval.text = 0;
 	    break;
@@ -348,7 +356,7 @@ S [afpnumkKMGT]
       return REALTIME; }
 
 
-  /* Notice and handle the timescale directive. */
+  /* Notice and handle the `timescale directive. */
 
 ^{W}?`timescale { BEGIN(PPTIMESCALE); }
 <PPTIMESCALE>.* { process_timescale(yytext); }
@@ -362,28 +370,54 @@ S [afpnumkKMGT]
       yylloc.first_line += 1;
       BEGIN(0); }
 
+  /* Notice and handle the `celldefine and `endcelldefine directives. */
+
+^{W}?`celldefine{W}?    { in_celldefine = true; }
+^{W}?`endcelldefine{W}? { in_celldefine = false; }
+
+  /* Notice and handle the resetall directive. */
+
+^{W}?`resetall{W}? {
+      if (in_module) {
+	    cerr << yylloc.text << ":" << yylloc.first_line << ": error: "
+		    "`resetall directive can not be inside a module "
+		    "definition." << endl;
+	    error_count += 1;
+      } else if (in_UDP) {
+	    cerr << yylloc.text << ":" << yylloc.first_line << ": error: "
+		    "`resetall directive can not be inside a UDP "
+		    "definition." << endl;
+	    error_count += 1;
+      } else {
+	    pform_set_default_nettype(NetNet::WIRE, yylloc.text,
+	                              yylloc.first_line);
+	    in_celldefine = false;
+	    pform_set_timescale(def_ts_units, def_ts_prec, 0, 0);
+	    /* Add `nounconnected_drive when implemented. */
+      } }
 
   /* These are directives that I do not yet support. I think that IVL
      should handle these, not an external preprocessor. */
+  /* From 1364-2005 Chapter 19. */
+^{W}?`nounconnected_drive{W}?.*     {  }
+^{W}?`pragme{W}?.*                  {  }
+^{W}?`unconnected_drive{W}?.*       {  }
 
-^{W}?`celldefine{W}?.*              {  }
+  /* From 1364-2005 Annex D. */
 ^{W}?`default_decay_time{W}?.*      {  }
 ^{W}?`default_trireg_strength{W}?.* {  }
 ^{W}?`delay_mode_distributed{W}?.*  {  }
-^{W}?`delay_mode_unit{W}?.*         {  }
 ^{W}?`delay_mode_path{W}?.*         {  }
+^{W}?`delay_mode_unit{W}?.*         {  }
 ^{W}?`delay_mode_zero{W}?.*         {  }
+
+  /* From other places. */
 ^{W}?`disable_portfaults{W}?.*      {  }
 ^{W}?`enable_portfaults{W}?.*       {  }
-^{W}?`endcelldefine{W}?.*           {  }
 `endprotect                         {  }
-^{W}?`line{W}?.*                    {  }
 ^{W}?`nosuppress_faults{W}?.*       {  }
-^{W}?`nounconnected_drive{W}?.*     {  }
 `protect                            {  }
-^{W}?`resetall{W}?.*                {  }
 ^{W}?`suppress_faults{W}?.*         {  }
-^{W}?`unconnected_drive{W}?.*       {  }
 ^{W}?`uselib{W}?.*                  {  }
 
 ^{W}?`begin_keywords{W}? { BEGIN(PPBEGIN_KEYWORDS); }
@@ -483,6 +517,12 @@ S [afpnumkKMGT]
 	   << endl;
   }
 
+^{W}?`elsif{W}?.* {
+      cerr << yylloc.text << ":" << yylloc.first_line <<
+	    ": warning: `elsif not supported. Use an external preprocessor."
+	   << endl;
+  }
+
 ^{W}?`endif{W}?.* {
       cerr << yylloc.text << ":" << yylloc.first_line <<
 	    ": warning: `endif not supported. Use an external preprocessor."
@@ -495,6 +535,12 @@ S [afpnumkKMGT]
 	   << endl;
   }
 
+^{W}?`ifndef{W}?.* {
+      cerr << yylloc.text << ":" << yylloc.first_line <<
+	    ": warning: `ifndef not supported. Use an external preprocessor."
+	   << endl;
+  }
+
 ^`include{W}?.* {
       cerr << yylloc.text << ":" << yylloc.first_line <<
 	    ": warning: `include not supported. Use an external preprocessor."
@@ -1053,47 +1099,150 @@ int yywrap()
  */
 static void line_directive()
 {
-      char*qt1 = strchr(yytext, '"');
-      assert(qt1);
-      qt1 += 1;
+      char *cpr;
+	/* Skip any leading space. */
+      char *cp = index(yytext, '#');
+	/* Skip the #line directive. */
+      assert(strncmp(cp, "#line", 5) == 0);
+      cp += 5;
+	/* Skip the space after the #line directive. */
+      cp += strspn(cp, " \t");
 
-      char*qt2 = strchr(qt1, '"');
-      assert(qt2);
+	/* Find the starting " and skip it. */
+      char*fn_start = strchr(cp, '"');
+      if (cp != fn_start) {
+	    VLerror(yylloc, "Invalid #line directive (file name start).");
+	    return;
+      }
+      fn_start += 1;
 
-      char*buf = new char[qt2-qt1+1];
-      strncpy(buf, qt1, qt2-qt1);
-      buf[qt2-qt1] = 0;
+	/* Find the last ". */
+      char*fn_end = strrchr(fn_start, '"');
+      if (!fn_end) {
+	    VLerror(yylloc, "Invalid #line directive (file name end).");
+	    return;
+      }
 
+	/* Copy the file name and assign it to yylloc. */
+      char*buf = new char[fn_end-fn_start+1];
+      strncpy(buf, fn_start, fn_end-fn_start);
+      buf[fn_end-fn_start] = 0;
+
+	/* Skip the space after the file name. */
+      cp = fn_end;
+      cp += 1;
+      cpr = cp;
+      cpr += strspn(cp, " \t");
+      if (cp == cpr) {
+	    VLerror(yylloc, "Invalid #line directive (missing space after "
+	                    "file name).");
+	    return;
+      }
+      cp = cpr;
+
+	/* Get the line number and verify that it is correct. */
+      unsigned long lineno = strtoul(cp, &cpr, 10);
+      if (cp == cpr) {
+	    VLerror(yylloc, "Invalid line number for #line directive.");
+	    return;
+      }
+      cp = cpr;
+
+	/* Verify that only space is left. */
+      cpr += strspn(cp, " \t");
+      if ((size_t)(cpr-yytext) != strlen(yytext)) {
+	    VLerror(yylloc, "Invalid #line directive (extra garbage after "
+	                    "line number).");
+	    return;
+      }
+
+	/* Now we can assign the new values to yyloc. */
       yylloc.text = set_file_name(buf);
-
-      qt2 += 1;
-      yylloc.first_line = strtoul(qt2,0,0);
+      yylloc.first_line = lineno;
 }
 
+/*
+ * The line directive matches lines of the form `line N "foo" M and
+ * calls this function. Here I parse out the file name and line
+ * number, and change the yylloc to suite. M is ignored.
+ */
 static void line_directive2()
 {
-      assert(strncmp(yytext,"`line",5) == 0);
-      char*cp = yytext + strlen("`line");
-      cp += strspn(cp, " ");
-      yylloc.first_line = strtoul(cp,&cp,10);
+      char *cpr;
+	/* Skip any leading space. */
+      char *cp = index(yytext, '`');
+	/* Skip the `line directive. */
+      assert(strncmp(cp, "`line", 5) == 0);
+      cp += 5;
 
-      yylloc.first_line -= 1;
+	/* strtoul skips leading space. */
+      unsigned long lineno = strtoul(cp, &cpr, 10);
+      if (cp == cpr) {
+	    VLerror(yylloc, "Invalid line number for `line directive.");
+	    return;
+      }
+      lineno -= 1;
+      cp = cpr;
 
-      cp += strspn(cp, " ");
-      if (*cp == 0) return;
+	/* Skip the space between the line number and the file name. */
+      cpr += strspn(cp, " \t");
+      if (cp == cpr) {
+	    VLerror(yylloc, "Invalid `line directive (missing space after "
+	                    "line number).");
+	    return;
+      }
+      cp = cpr;
 
-      char*qt1 = strchr(yytext, '"');
-      assert(qt1);
-      qt1 += 1;
+	/* Find the starting " and skip it. */
+      char*fn_start = strchr(cp, '"');
+      if (cp != fn_start) {
+	    VLerror(yylloc, "Invalid `line directive (file name start).");
+	    return;
+      }
+      fn_start += 1;
 
-      char*qt2 = strchr(qt1, '"');
-      assert(qt2);
+	/* Find the last ". */
+      char*fn_end = strrchr(fn_start, '"');
+      if (!fn_end) {
+	    VLerror(yylloc, "Invalid `line directive (file name end).");
+	    return;
+      }
 
-      char*buf = new char[qt2-qt1+1];
-      strncpy(buf, qt1, qt2-qt1);
-      buf[qt2-qt1] = 0;
+	/* Skip the space after the file name. */
+      cp = fn_end;
+      cp += 1;
+      cpr = cp;
+      cpr += strspn(cp, " \t");
+      if (cp == cpr) {
+	    VLerror(yylloc, "Invalid `line directive (missing space after "
+	                    "file name).");
+	    return;
+      }
+      cp = cpr;
+
+	/* Check that the level is correct, we do not need the level. */
+      strtoul(cp, &cpr, 10);
+      if (cp == cpr) {
+	    VLerror(yylloc, "Invalid level for `line directive.");
+	    return;
+      }
+      cp = cpr;
+
+	/* Verify that only space is left. */
+      cpr += strspn(cp, " \t");
+      if ((size_t)(cpr-yytext) != strlen(yytext)) {
+	    VLerror(yylloc, "Invalid `line directive (extra garbage after "
+	                    "level).");
+	    return;
+      }
+
+	/* Copy the file name and assign it and the line number to yylloc. */
+      char*buf = new char[fn_end-fn_start+1];
+      strncpy(buf, fn_start, fn_end-fn_start);
+      buf[fn_end-fn_start] = 0;
 
       yylloc.text = set_file_name(buf);
+      yylloc.first_line = lineno;
 }
 
 extern FILE*vl_input;
diff --git a/main.cc b/main.cc
index c692a154a..b3f1201c0 100644
--- a/main.cc
+++ b/main.cc
@@ -142,6 +142,9 @@ bool verbose_flag = false;
 
 unsigned integer_width = 32;
 
+int def_ts_units = 0;
+int def_ts_prec = 0;
+
 /*
  * Keep a heap of identifier strings that I encounter. This is a more
  * efficient way to allocate those strings.
@@ -726,6 +729,7 @@ int main(int argc, char*argv[])
       if (flag_tmp) recursive_mod_limit = strtoul(flag_tmp,NULL,0);
 
 	/* Parse the input. Make the pform. */
+      pform_set_timescale(def_ts_units, def_ts_prec, 0, 0);
       int rc = pform_parse(argv[optind]);
 
       if (pf_path) {
diff --git a/net_scope.cc b/net_scope.cc
index 851ab0fb1..3a2e6f91b 100644
--- a/net_scope.cc
+++ b/net_scope.cc
@@ -41,6 +41,7 @@ NetScope::NetScope(NetScope*up, const hname_t&n, NetScope::TYPE t)
       events_ = 0;
       lcounter_ = 0;
       is_auto_ = false;
+      is_cell_ = false;
 
       if (up) {
 	    default_nettype_ = up->default_nettype();
diff --git a/netlist.h b/netlist.h
index ca9c78fbc..387adffc8 100644
--- a/netlist.h
+++ b/netlist.h
@@ -761,6 +761,10 @@ class NetScope : public Attrib {
       void is_auto(bool is_auto__) { is_auto_ = is_auto__; };
       bool is_auto() const { return is_auto_; };
 
+	/* Is the module a cell (is in a `celldefine) */
+      void is_cell(bool is_cell__) { is_cell_ = is_cell__; };
+      bool is_cell() const { return is_cell_; };
+
       const NetTaskDef* task_def() const;
       const NetFuncDef* func_def() const;
 
@@ -908,7 +912,7 @@ class NetScope : public Attrib {
       NetScope*sub_;
 
       unsigned lcounter_;
-      bool is_auto_;
+      bool is_auto_, is_cell_;
 };
 
 /*
diff --git a/parse.y b/parse.y
index 764d99ffc..e24d67bbc 100644
--- a/parse.y
+++ b/parse.y
@@ -921,6 +921,21 @@ expression
 		  FILE_NAME(tmp, @2);
 		  $$ = tmp;
 		}
+	| '~' '&' expr_primary %prec UNARY_PREC
+		{ yyerror(@1, "error: '~' '&'  is not a valid expression. "
+			  "Please use operator '~&' instead.");
+		  $$ = 0;
+		}
+	| '~' '|' expr_primary %prec UNARY_PREC
+		{ yyerror(@1, "error: '~' '|'  is not a valid expression. "
+			  "Please use operator '~|' instead.");
+		  $$ = 0;
+		}
+	| '~' '^' expr_primary %prec UNARY_PREC
+		{ yyerror(@1, "error: '~' '^'  is not a valid expression. "
+			  "Please use operator '~^' instead.");
+		  $$ = 0;
+		}
 	| K_NAND expr_primary %prec UNARY_PREC
 		{ PEUnary*tmp = new PEUnary('A', $2);
 		  FILE_NAME(tmp, @2);
@@ -1908,7 +1923,7 @@ module  : attribute_list_opt module_start IDENTIFIER
 		{ pform_module_set_ports($6); }
 	  module_item_list_opt
 	  K_endmodule
-		{ pform_endmodule($3);
+		{ pform_endmodule($3, in_celldefine);
 		  delete[]$3;
 		}
 
diff --git a/parse_api.h b/parse_api.h
index 76ea71531..ba23c564e 100644
--- a/parse_api.h
+++ b/parse_api.h
@@ -1,7 +1,7 @@
 #ifndef __parse_api_H
 #define __parse_api_H
 /*
- * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 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
@@ -46,4 +46,9 @@ extern int  pform_parse(const char*path, FILE*file =0);
 
 extern string vl_file;
 
+extern void pform_set_timescale(int units, int prec, const char*file,
+                                unsigned lineno);
+extern int def_ts_units;
+extern int def_ts_prec;
+
 #endif
diff --git a/parse_misc.h b/parse_misc.h
index d82b3c8f9..6aa623a13 100644
--- a/parse_misc.h
+++ b/parse_misc.h
@@ -1,7 +1,7 @@
 #ifndef __parse_misc_H
 #define __parse_misc_H
 /*
- * Copyright (c) 1998-2000 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2009 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
@@ -65,4 +65,6 @@ extern ostream& operator << (ostream&, const YYLTYPE&loc);
 extern unsigned error_count, warn_count;
 extern unsigned long based_size;
 
+extern bool in_celldefine;
+
 #endif
diff --git a/pform.cc b/pform.cc
index b3bac9103..52dfed03c 100644
--- a/pform.cc
+++ b/pform.cc
@@ -70,11 +70,11 @@ static NetNet::Type pform_default_nettype = NetNet::WIRE;
  * These variables track the current time scale, as well as where the
  * timescale was set. This supports warnings about tangled timescales.
  */
-static int pform_time_unit = 0;
-static int pform_time_prec = 0;
+static int pform_time_unit;
+static int pform_time_prec;
 
 static char*pform_timescale_file = 0;
-static unsigned pform_timescale_line = 0;
+static unsigned pform_timescale_line;
 
 static inline void FILE_NAME(LineInfo*obj, const char*file, unsigned lineno)
 {
@@ -298,10 +298,25 @@ void pform_set_timescale(int unit, int prec,
 	    first_flag = false;
       }
 
-      pform_timescale_file = strdup(file);
+      if (file) pform_timescale_file = strdup(file);
+      else pform_timescale_file = 0;
       pform_timescale_line = lineno;
 
-      if (warn_timescale && first_flag && (pform_modules.size() > 0)) {
+      if (!warn_timescale || !first_flag || !file) return;
+
+	/* Look to see if we have any modules without a timescale. */
+      bool have_no_ts = false;
+      map<perm_string,Module*>::iterator mod;
+      for (mod = pform_modules.begin(); mod != pform_modules.end(); mod++) {
+	    const Module*mp = (*mod).second;
+	    if (mp->time_from_timescale ||
+	        mp->timescale_warn_done) continue;
+	    have_no_ts = true;
+	    break;
+      }
+
+	/* If we do then print a message for the new ones. */
+      if (have_no_ts) {
 	    cerr << file << ":" << lineno << ": warning: "
 		 << "Some modules have no timescale. This may cause"
 		 << endl;
@@ -312,7 +327,10 @@ void pform_set_timescale(int unit, int prec,
 	    map<perm_string,Module*>::iterator mod;
 	    for (mod = pform_modules.begin()
 		       ; mod != pform_modules.end() ; mod++) {
-		  const Module*mp = (*mod).second;
+		  Module*mp = (*mod).second;
+		  if (mp->time_from_timescale ||
+		      mp->timescale_warn_done) continue;
+		  mp->timescale_warn_done = true;
 
 		  cerr << file << ":" << lineno << ":        : "
 		       << "  -- module " << (*mod).first
@@ -449,11 +467,12 @@ void pform_module_set_ports(vector<Module::port_t*>*ports)
       }
 }
 
-void pform_endmodule(const char*name)
+void pform_endmodule(const char*name, bool in_celldefine)
 {
       assert(pform_cur_module);
       perm_string mod_name = pform_cur_module->mod_name();
       assert(strcmp(name, mod_name) == 0);
+      pform_cur_module->is_cell = in_celldefine;
 
       map<perm_string,Module*>::const_iterator test =
 	    pform_modules.find(mod_name);
diff --git a/pform.h b/pform.h
index ef18234e9..92166d41b 100644
--- a/pform.h
+++ b/pform.h
@@ -159,7 +159,7 @@ extern void pform_module_define_port(const struct vlltype&li,
 extern Module::port_t* pform_module_port_reference(perm_string name,
 						   const char*file,
 						   unsigned lineno);
-extern void pform_endmodule(const char*);
+extern void pform_endmodule(const char*, bool in_celldefine);
 
 extern void pform_make_udp(perm_string name, list<perm_string>*parms,
 			   svector<PWire*>*decl, list<string>*table,
diff --git a/pform_dump.cc b/pform_dump.cc
index e65a7c7bc..a522eb8ac 100644
--- a/pform_dump.cc
+++ b/pform_dump.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998-2008 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2009 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
@@ -1147,7 +1147,9 @@ void Module::dump(ostream&out) const
 	    out << " *)  ";
       }
 
-      out << "module " << mod_name() << ";" << endl;
+      out << "module " << mod_name() << ";";
+      if (is_cell) out << "  // Is in `celldefine.";
+      out << endl;
 
       for (unsigned idx = 0 ;  idx < ports.size() ;  idx += 1) {
 	    port_t*cur = ports[idx];
diff --git a/t-dll-api.cc b/t-dll-api.cc
index 46e261b93..e5a513e8d 100644
--- a/t-dll-api.cc
+++ b/t-dll-api.cc
@@ -1655,6 +1655,12 @@ extern "C" unsigned ivl_scope_is_auto(ivl_scope_t net)
       return net->is_auto;
 }
 
+extern "C" unsigned ivl_scope_is_cell(ivl_scope_t net)
+{
+      assert(net);
+      return net->is_cell;
+}
+
 extern "C" unsigned ivl_scope_lineno(ivl_scope_t net)
 {
       assert(net);
diff --git a/t-dll.cc b/t-dll.cc
index a66feefb3..f1b18f857 100644
--- a/t-dll.cc
+++ b/t-dll.cc
@@ -2389,6 +2389,7 @@ void dll_target::scope(const NetScope*net)
 	    scop->nattr = net->attr_cnt();
 	    scop->attr = fill_in_attributes(net);
 	    scop->is_auto = net->is_auto();
+	    scop->is_cell = net->is_cell();
 
 	    switch (net->type()) {
 		case NetScope::MODULE:
diff --git a/t-dll.h b/t-dll.h
index e6c7bd6bc..5006a6ab4 100644
--- a/t-dll.h
+++ b/t-dll.h
@@ -606,6 +606,8 @@ struct ivl_scope_s {
       ivl_statement_t def;
       unsigned is_auto;
 
+      unsigned is_cell;
+
       unsigned ports;
       ivl_signal_t*port;
 
diff --git a/tgt-stub/stub.c b/tgt-stub/stub.c
index 98723b0a8..2a378b737 100644
--- a/tgt-stub/stub.c
+++ b/tgt-stub/stub.c
@@ -1533,7 +1533,8 @@ static int show_scope(ivl_scope_t net, void*x)
       is_auto = ivl_scope_is_auto(net) ? "automatic " : "";
       switch (ivl_scope_type(net)) {
 	  case IVL_SCT_MODULE:
-	    fprintf(out, " module %s", ivl_scope_tname(net));
+	    fprintf(out, " module %s%s", ivl_scope_tname(net),
+                    ivl_scope_is_cell(net) ? " (cell)" : "");
 	    break;
 	  case IVL_SCT_FUNCTION:
 	    fprintf(out, " function %s%s", is_auto, ivl_scope_tname(net));
diff --git a/tgt-vvp/vvp_scope.c b/tgt-vvp/vvp_scope.c
index eea3ab47b..3d6b119ca 100644
--- a/tgt-vvp/vvp_scope.c
+++ b/tgt-vvp/vvp_scope.c
@@ -1825,9 +1825,9 @@ int draw_scope(ivl_scope_t net, ivl_scope_t parent)
               ivl_scope_lineno(net));
 
       if (parent) {
-	    fprintf(vvp_out, ", %d %d, S_%p;\n",
+	    fprintf(vvp_out, ", %d %d %u, S_%p;\n",
 	            ivl_file_table_index(ivl_scope_def_file(net)),
-	            ivl_scope_def_lineno(net), parent);
+	            ivl_scope_def_lineno(net), ivl_scope_is_cell(net), parent);
       } else {
 
 	    fprintf(vvp_out, ";\n");
diff --git a/vpi_user.h b/vpi_user.h
index c335c0a72..ba019190b 100644
--- a/vpi_user.h
+++ b/vpi_user.h
@@ -304,33 +304,34 @@ typedef struct t_vpi_delay  {
 #define vpiCallback  1000
 
 /* PROPERTIES */
-#define vpiUndefined  (-1)
-#define vpiType       1
-#define vpiName       2
-#define vpiFullName   3
-#define vpiSize       4
-#define vpiFile       5
-#define vpiLineNo     6
-#define vpiTopModule  7
-#define vpiDefName    9
+#define vpiUndefined   (-1)
+#define vpiType           1
+#define vpiName           2
+#define vpiFullName       3
+#define vpiSize           4
+#define vpiFile           5
+#define vpiLineNo         6
+#define vpiTopModule      7
+#define vpiCellInstance   8
+#define vpiDefName        9
 #define vpiTimeUnit      11
 #define vpiTimePrecision 12
-#define vpiDefFile   15
-#define vpiDefLineNo 16
-#define vpiNetType   22
-#   define vpiWire        1
-#define vpiArray     28
-#define vpiEdge      36
-#   define vpiNoEdge     0x00 /* No edge */
-#   define vpiEdge01     0x01 /* 0 --> 1 */
-#   define vpiEdge10     0x02 /* 1 --> 0 */
-#   define vpiEdge0x     0x04 /* 0 --> x */
-#   define vpiEdgex1     0x08 /* x --> 1 */
-#   define vpiEdge1x     0x10 /* 1 --> x */
-#   define vpiEdgex0     0x20 /* x --> 0 */
-#   define vpiPosedge    (vpiEdgex1|vpiEdge01|vpiEdge0x)
-#   define vpiNegedge    (vpiEdgex0|vpiEdge10|vpiEdge1x)
-#   define vpiAnyEdge    (vpiPosedge|vpiNegedge)
+#define vpiDefFile       15
+#define vpiDefLineNo     16
+#define vpiNetType       22
+#   define vpiWire         1
+#define vpiArray         28
+#define vpiEdge          36
+#   define vpiNoEdge       0x00 /* No edge */
+#   define vpiEdge01       0x01 /* 0 --> 1 */
+#   define vpiEdge10       0x02 /* 1 --> 0 */
+#   define vpiEdge0x       0x04 /* 0 --> x */
+#   define vpiEdgex1       0x08 /* x --> 1 */
+#   define vpiEdge1x       0x10 /* 1 --> x */
+#   define vpiEdgex0       0x20 /* x --> 0 */
+#   define vpiPosedge      (vpiEdgex1|vpiEdge01|vpiEdge0x)
+#   define vpiNegedge      (vpiEdgex0|vpiEdge10|vpiEdge1x)
+#   define vpiAnyEdge      (vpiPosedge|vpiNegedge)
 #define vpiConstType 40
 #   define vpiDecConst    1
 #   define vpiRealConst   2
diff --git a/vvp/compile.h b/vvp/compile.h
index c28036755..f63732246 100644
--- a/vvp/compile.h
+++ b/vvp/compile.h
@@ -414,7 +414,8 @@ extern void compile_codelabel(char*label);
  */
 extern void compile_scope_decl(char*typ, char*lab, char*nam, char*tnam,
                                char*par, long file_idx, long lineno,
-                               long def_file_idx, long def_lineno);
+                               long def_file_idx, long def_lineno,
+                               long is_cell);
 extern void compile_scope_recall(char*sym);
 
 /*
diff --git a/vvp/parse.y b/vvp/parse.y
index ae2454891..03cf2dccf 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -574,19 +574,19 @@ statement
      parent scope, then this is a root scope. */
 
 	| T_LABEL K_SCOPE T_SYMBOL ',' T_STRING T_STRING T_NUMBER T_NUMBER ';'
-		{ compile_scope_decl($1, $3, $5, $6, 0, $7, $8, $7, $8); }
+		{ compile_scope_decl($1, $3, $5, $6, 0, $7, $8, $7, $8, 0); }
 
 	| T_LABEL K_SCOPE T_SYMBOL ',' T_STRING T_STRING T_NUMBER T_NUMBER ','
-	  T_NUMBER T_NUMBER ',' T_SYMBOL ';'
-		{ compile_scope_decl($1, $3, $5, $6, $13, $7, $8, $10, $11); }
+	  T_NUMBER T_NUMBER T_NUMBER ',' T_SYMBOL ';'
+		{ compile_scope_decl($1, $3, $5, $6, $14, $7, $8, $10, $11, $12); }
 
   /* XXXX Legacy declaration has no type name. */
 
 	| T_LABEL K_SCOPE T_SYMBOL ',' T_STRING ';'
-		{ compile_scope_decl($1, $3, $5, 0, 0, 0, 0, 0, 0); }
+		{ compile_scope_decl($1, $3, $5, 0, 0, 0, 0, 0, 0, 0); }
 
 	| T_LABEL K_SCOPE T_SYMBOL ',' T_STRING ',' T_SYMBOL ';'
-		{ compile_scope_decl($1, $3, $5, 0, $7, 0, 0, 0, 0); }
+		{ compile_scope_decl($1, $3, $5, 0, $7, 0, 0, 0, 0, 0); }
 
   /* Scope recall has no label of its own, but refers by label to a
      declared scope. */
diff --git a/vvp/stop.cc b/vvp/stop.cc
index 0b6aad7a3..889f1b90f 100644
--- a/vvp/stop.cc
+++ b/vvp/stop.cc
@@ -478,6 +478,13 @@ static void invoke_command(char*txt)
       delete[]argv;
 }
 
+static void invoke_command_const(const char*txt)
+{
+      char *vtxt = strdup(txt);
+      invoke_command(vtxt);
+      free(vtxt);
+}
+
 void stop_handler(int rc)
 {
         /* The user may be running in a non-interactive environment, so
@@ -489,8 +496,8 @@ void stop_handler(int rc)
 
       vpi_mcd_printf(1,"** VVP Stop(%d) **\n", rc);
       vpi_mcd_printf(1,"** Flushing output streams.\n");
-      invoke_command("$fflush");
-      invoke_command("$dumpflush");
+      invoke_command_const("$fflush");
+      invoke_command_const("$dumpflush");
       vpi_mcd_printf(1,"** Current simulation time is %" TIME_FMT_U " ticks.\n",
 		     schedule_simtime());
 
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index a3a40653a..a1d0ba6e8 100644
--- a/vvp/vpi_priv.h
+++ b/vvp/vpi_priv.h
@@ -186,6 +186,7 @@ struct __vpiScope {
       unsigned def_file_idx;
       unsigned def_lineno;
       bool is_automatic;
+      bool is_cell;
 	/* The scope has a system time of its own. */
       struct __vpiSystemTime scoped_time;
       struct __vpiSystemTime scoped_stime;
diff --git a/vvp/vpi_scope.cc b/vvp/vpi_scope.cc
index 975928bfe..ac3aac5a5 100644
--- a/vvp/vpi_scope.cc
+++ b/vvp/vpi_scope.cc
@@ -128,6 +128,9 @@ static int scope_get(int code, vpiHandle obj)
       assert(handle_is_scope(obj));
 
       switch (code) {
+	  case vpiCellInstance:
+	    return (int) ref->is_cell;
+
 	  case vpiDefLineNo:
 	    return ref->def_lineno;
 
@@ -395,7 +398,7 @@ static void attach_to_scope_(struct __vpiScope*scope, vpiHandle obj)
 void
 compile_scope_decl(char*label, char*type, char*name, char*tname,
                    char*parent, long file_idx, long lineno,
-                   long def_file_idx, long def_lineno)
+                   long def_file_idx, long def_lineno, long is_cell)
 {
       struct __vpiScope*scope = new struct __vpiScope;
       count_vpi_scopes += 1;
@@ -409,6 +412,9 @@ compile_scope_decl(char*label, char*type, char*name, char*tname,
             base_type = &type[0];
       }
 
+      if (is_cell) scope->is_cell = true;
+      else scope->is_cell = false;
+
       if (strcmp(base_type,"module") == 0) {
 	    scope->base.vpi_type = &vpip_scope_module_rt;
       } else if (strcmp(base_type,"function") == 0) {