Modified behavior for the "-noflatten" option on LVS: Added a

command option "flatten prohibit" (or "flatten deny") to prevent
a subcell from being flattened at any time during the compare
process.  Previously, the "-noflatten" option for the "lvs"
script had been used to prevent flattening during initial
pre-match, but if the circuit passed the prematch phase and
subcells were mismatched, they would be flattened regardless of
whether or not they were listed by the "-noflatten" option.  This
also codifies a way to prevent subcells from being flattened in
the setup file rather than in the "lvs" command line.  Also:
Found and fixed a bug that prevents the use of "-noflatten=" with
a cell name or list of cell names instead of a filename.

VERSION

@@ -1 +1 @@
-1.5.227
+1.5.228

base/flatten.c

@@ -69,6 +69,10 @@ void flattenCell(char *name, int file)
     Printf("No cell %s found.\n", name);
     return;
   }
+
+  /* Placeholder cells must not be flattened */
+  if (ThisCell->flags & CELL_PLACEHOLDER) return;
+
   FreeNodeNames(ThisCell);
 
   ParentParams = ThisCell->cell;
@@ -288,6 +292,9 @@ int flattenInstancesOf(char *name, int fnum, char *instance)
       return 0;
     }
   }
+  /* Placeholder cells must not be flattened */
+  if (ThisCell->flags & CELL_PLACEHOLDER) return 0;
+
   FreeNodeNames(ThisCell);
 
   ParentParams = ThisCell->cell;
@@ -1620,19 +1627,22 @@ PrematchLists(char *name1, int file1, char *name2, int file2)
 		}
 	    }
 	    if (match) {
-		if (ecomp->cell1 && (ecomp->num1 > 0)) {
+		if (ecomp->cell1 && (ecomp->num1 > 0) &&
+				(!(ecomp->cell1->flags & CELL_PLACEHOLDER))) {
 		    Fprintf(stdout, "Flattening instances of %s in cell %s (%d)"
 				" makes a better match\n", ecomp->cell1->name,
 				name1, file1);
 		    flattenInstancesOf(name1, file1, ecomp->cell1->name); 
+		    modified++;
 		}
-		if (ecomp->cell2 && (ecomp->num2 > 0)) {
+		if (ecomp->cell2 && (ecomp->num2 > 0) &&
+				(!(ecomp->cell2->flags & CELL_PLACEHOLDER))) {
 		    Fprintf(stdout, "Flattening instances of %s in cell %s (%d)"
 				" makes a better match\n", ecomp->cell2->name,
 				name2, file2);
 		    flattenInstancesOf(name2, file2, ecomp->cell2->name); 
+		    modified++;
 		}
-		modified++;
 	    }
 
 	    /* Reset or apply the count adjustments */
@@ -1716,13 +1726,13 @@ PrematchLists(char *name1, int file1, char *name2, int file2)
 		if ((ecomp->num1 == 0) || (ecomp->cell1->class !=
 				CLASS_MODULE)) {
 
-		    if (ecomp->cell2) {
+		    if (ecomp->cell2 && !(ecomp->cell2->flags & CELL_PLACEHOLDER)) {
 		    	Fprintf(stdout, "Flattening instances of %s in cell %s (%d)"
 				" makes a better match\n", ecomp->cell2->name,
 				name2, file2);
 		    	flattenInstancesOf(name2, file2, ecomp->cell2->name); 
+		    	modified++;
 		    }
-		    modified++;
 		}
 	    }
 
@@ -1782,13 +1792,13 @@ PrematchLists(char *name1, int file1, char *name2, int file2)
 		if ((ecomp->num2 == 0) || (ecomp->cell2->class !=
 				CLASS_MODULE)) {
 
-		    if (ecomp->cell1) {
+		    if (ecomp->cell1 && !(ecomp->cell1->flags & CELL_PLACEHOLDER)) {
 		    	Fprintf(stdout, "Flattening instances of %s in cell %s (%d)"
 				" makes a better match\n", ecomp->cell1->name,
 				name1, file1);
 		    	flattenInstancesOf(name1, file1, ecomp->cell1->name); 
+		        modified++;
 		    }
-		    modified++;
 		}
 	    }
 

tcltk/netgen.tcl.in

@@ -393,7 +393,7 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
 	 # If argument is a filename then read the list of cells from it;
 	 # otherwise, argument is the list of files itself in quotes or
 	 # braces.
-	 if {![catch {file exists $value}]} {
+	 if {[file exists $value]} {
 	    if {![catch {open $value r} fnf]} {
 	       while {[gets $fnf line] >= 0} {
 		  if {[lindex $line 0] != "#"} {
@@ -569,6 +569,8 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
 	           netgen::log put "  Continuing with black-boxed subcircuits $endval\n"
 		   lappend matcherr [lindex $endval 0]"($fnum1)"
 		   lappend matcherr [lindex $endval 1]"($fnum2)"
+		   netgen::flatten prohibit "[lindex $endval 0] $fnum1"
+		   netgen::flatten prohibit "[lindex $endval 1] $fnum2"
 	           # Match pins
                    netgen::log echo off
 	           if {$dolist == 1} {

tcltk/tclnetgen.c

@@ -1056,6 +1056,12 @@ _netgen_flatten(ClientData clientData,
             FlattenInstancesOf(repstr, filenum);
 	 }
       }
+      else if (!strcmp(argv, "prohibit") || !strcmp(argv, "deny")) {
+	 tp = GetTopCell(filenum);
+	 Printf("Will not flatten instances of %s in file %s\n", repstr, tp->name);
+	 /* Mark cell as placeholder so it will not be flattened */
+	 tp->flags |= CELL_PLACEHOLDER;
+      }
       else {
 	 Tcl_WrongNumArgs(interp, 1, objv, "class valid_cellname");
 	 return TCL_ERROR;