Parse all the 1364-1995 and 1364-2001 timing checks.

This patch adds code to parse and ignore the following timing checks:

$nochange  1364-1995
$skew      1364-1995
$fullskew  1364-2001
$removal   1364-2001
$timeskew  1364-2001

The other checks were already supported. These have not been tested,
but they use the same basic terms as the other checks. We can fully
test these when we actually implement them.

lexor.lex

@@ -274,22 +274,35 @@ S [afpnumkKMGT]
       return IDENTIFIER; }
 
 \$([a-zA-Z0-9$_]+)        {
-      if (strcmp(yytext,"$setuphold") == 0)
+	/* The 1364-1995 timing checks. */
-	    return K_Ssetuphold;
-      if (strcmp(yytext,"$attribute") == 0)
-	    return KK_attribute;
       if (strcmp(yytext,"$hold") == 0)
 	    return K_Shold;
+      if (strcmp(yytext,"$nochange") == 0)
+	    return K_Snochange;
       if (strcmp(yytext,"$period") == 0)
 	    return K_Speriod;
       if (strcmp(yytext,"$recovery") == 0)
 	    return K_Srecovery;
-      if (strcmp(yytext,"$recrem") == 0)
-	    return K_Srecrem;
       if (strcmp(yytext,"$setup") == 0)
 	    return K_Ssetup;
+      if (strcmp(yytext,"$setuphold") == 0)
+	    return K_Ssetuphold;
+      if (strcmp(yytext,"$skew") == 0)
+	    return K_Sskew;
       if (strcmp(yytext,"$width") == 0)
 	    return K_Swidth;
+	/* The new 1364-2001 timing checks. */
+      if (strcmp(yytext,"$fullskew") == 0)
+	    return K_Sfullskew;
+      if (strcmp(yytext,"$recrem") == 0)
+	    return K_Srecrem;
+      if (strcmp(yytext,"$removal") == 0)
+	    return K_Sremoval;
+      if (strcmp(yytext,"$timeskew") == 0)
+	    return K_Stimeskew;
+
+      if (strcmp(yytext,"$attribute") == 0)
+	    return KK_attribute;
       yylval.text = strdupnew(yytext);
       return SYSTEM_IDENTIFIER; }
 

parse.y

@@ -248,7 +248,8 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
 %token K_trireg K_vectored K_wait K_wand K_weak0 K_weak1 K_while K_wire
 %token K_wor K_xnor K_xor
 
-%token K_Shold K_Speriod K_Srecovery K_Ssetup K_Swidth K_Ssetuphold
+%token K_Shold K_Snochange K_Speriod K_Srecovery K_Ssetup K_Ssetuphold
+%token K_Sskew K_Swidth
 
  /* Icarus specific tokens. */
 %token KK_attribute K_bool K_logic
@@ -258,7 +259,7 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
 %token K_noshowcancelled K_pulsestyle_onevent K_pulsestyle_ondetect
 %token K_showcancelled K_signed K_unsigned
 
-%token K_Srecrem
+%token K_Sfullskew K_Srecrem K_Sremoval K_Stimeskew
 
  /* The 1364-2001 configuration tokens. */
 %token K_cell K_config K_design K_endconfig K_incdir K_include K_instance
@@ -3199,10 +3200,20 @@ specify_item
 		  }
 		  pform_module_specify_path(tmp);
 		}
+	| K_Sfullskew '(' spec_reference_event ',' spec_reference_event
+	  ',' delay_value ',' delay_value spec_notifier_opt ')' ';'
+		{ delete $7;
+		  delete $9;
+		}
 	| K_Shold '(' spec_reference_event ',' spec_reference_event
 	  ',' delay_value spec_notifier_opt ')' ';'
 		{ delete $7;
 		}
+	| K_Snochange '(' spec_reference_event ',' spec_reference_event
+	  ',' delay_value ',' delay_value spec_notifier_opt ')' ';'
+		{ delete $7;
+		  delete $9;
+		}
 	| K_Speriod '(' spec_reference_event ',' delay_value
 	  spec_notifier_opt ')' ';'
 		{ delete $5;
@@ -3211,6 +3222,15 @@ specify_item
 	  ',' delay_value spec_notifier_opt ')' ';'
 		{ delete $7;
 		}
+	| K_Srecrem '(' spec_reference_event ',' spec_reference_event
+	  ',' delay_value ',' delay_value spec_notifier_opt ')' ';'
+		{ delete $7;
+		  delete $9;
+		}
+	| K_Sremoval '(' spec_reference_event ',' spec_reference_event
+	  ',' delay_value spec_notifier_opt ')' ';'
+		{ delete $7;
+		}
 	| K_Ssetup '(' spec_reference_event ',' spec_reference_event
 	  ',' delay_value spec_notifier_opt ')' ';'
 		{ delete $7;
@@ -3220,10 +3240,13 @@ specify_item
 		{ delete $7;
 		  delete $9;
 		}
-	| K_Srecrem '(' spec_reference_event ',' spec_reference_event
+	| K_Sskew '(' spec_reference_event ',' spec_reference_event
-	  ',' delay_value ',' delay_value spec_notifier_opt ')' ';'
+	  ',' delay_value spec_notifier_opt ')' ';'
+		{ delete $7;
+		}
+	| K_Stimeskew '(' spec_reference_event ',' spec_reference_event
+	  ',' delay_value spec_notifier_opt ')' ';'
 		{ delete $7;
-		  delete $9;
 		}
 	| K_Swidth '(' spec_reference_event ',' delay_value ',' expression
 	  spec_notifier_opt ')' ';'