experimental directive "allow holes" to allow multiple holes per pad

This is for thermal vias and the unusual grounding method NXP use in
their HVQFN33 footprints.

README

@@ -177,7 +177,14 @@ allow overlap
 Do not check for overlaps at all.
 
 If the "allow" directive is omitted, fped defaults to allowing
-neigher overlap nor touch.
+neither overlap nor touch.
+
+There is also the following experimental directive that can be used
+alone or without one of the overlap-checking directives:
+
+allow holes
+
+Allow multiple holes per pad.
 
 
 Vectors

dump.c

@@ -591,6 +591,8 @@ static void dump_allow(FILE *file)
 	default:
 		abort();
 	}
+	if (!holes_linked)
+		fprintf(file, "allow holes\n");
 }
 
 

fpd.l

@@ -133,6 +133,7 @@ SP	[\t ]*
 <INITIAL>"allow"		BEGIN(ALLOW);
 <ALLOW>"overlap"		return TOK_ALLOW_OVERLAP;
 <ALLOW>"touch"			return TOK_ALLOW_TOUCH;
+<ALLOW>"holes"			return TOK_ALLOW_HOLES;
 
 <INITIAL>"%del"			{ BEGIN(NOKEYWORD);
 				  return TOK_DBG_DEL; }

fpd.y

@@ -462,7 +462,7 @@ static int dbg_meas(const char *name)
 %token		TOK_DBG_DEL TOK_DBG_MOVE TOK_DBG_FRAME
 %token		TOK_DBG_PRINT TOK_DBG_IPRINT
 %token		TOK_DBG_DUMP TOK_DBG_EXIT TOK_DBG_TSORT TOK_DBG_MEAS
-%token		TOK_ALLOW_OVERLAP TOK_ALLOW_TOUCH
+%token		TOK_ALLOW_HOLES TOK_ALLOW_OVERLAP TOK_ALLOW_TOUCH
 
 %token	<num>	NUMBER
 %token	<str>	STRING
@@ -544,9 +544,16 @@ opt_setup:
 
 setup:
 	unit
-	| allow
-	| unit allow
-	| allow unit
+	| allow_pads
+	| allow_holes
+	| unit allow_pads
+	| unit allow_pads allow_holes
+	| unit allow_holes
+	| unit allow_holes allow_pads
+	| allow_pads unit
+	| allow_pads unit allow_holes
+	| allow_holes unit
+	| allow_holes unit allow_pads
 	;
 
 unit:
@@ -565,7 +572,7 @@ unit:
 		}
 	;
 
-allow:
+allow_pads:
 	TOK_ALLOW_TOUCH
 		{
 			allow_overlap = ao_touch;
@@ -576,6 +583,13 @@ allow:
 		}
 	;
 
+allow_holes:
+	TOK_ALLOW_HOLES
+		{
+			holes_linked = 0;
+		}
+	;
+
 frame_defs:
 	| frame_defs frame_def
 	;

hole.c

@@ -1,8 +1,8 @@
 /*
  * hole.c - Classify holes and connect them with pads
  *
- * Written 2010 by Werner Almesberger
- * Copyright 2010 by Werner Almesberger
+ * Written 2010, 2012 by Werner Almesberger
+ * Copyright 2010, 2012 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -73,14 +73,15 @@ static void clear_links(const struct pkg *pkg)
 }
 
 
-int link_holes(void)
+int link_holes(int linked)
 {
 	const struct pkg *pkg;
 
 	for (pkg = pkgs; pkg; pkg = pkg->next) {
 		clear_links(pkg);
-		if (!connect_holes(pkg))
-			return 0;
+		if (linked)
+			if (!connect_holes(pkg))
+				return 0;
 	}
         return 1;
 }

hole.h

@@ -1,8 +1,8 @@
 /*
  * hole.h - Classify holes and connect them with pads
  *
- * Written 2010 by Werner Almesberger
- * Copyright 2010 by Werner Almesberger
+ * Written 2010, 2012 by Werner Almesberger
+ * Copyright 2010, 2012 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -13,6 +13,6 @@
 #ifndef HOLE_H
 #define HOLE_H
 
-int link_holes(void);
+int link_holes(int linked);
 
 #endif /* !HOLE_H */

obj.c

@@ -40,6 +40,7 @@ struct frame *frames = NULL;
 struct frame *active_frame = NULL;
 void *instantiation_error = NULL;
 enum allow_overlap allow_overlap = ao_none;
+int holes_linked = 1;
 
 
 static struct bitset *frame_set; /* frames visited in "call chain" */
@@ -577,7 +578,7 @@ int instantiate(void)
 	find_vec = NULL;
 	find_obj = NULL;
 	if (ok)
-		ok = link_holes();
+		ok = link_holes(holes_linked);
 	if (ok)
 		ok = refine_layers(allow_overlap);
 	if (ok)

obj.h

@@ -255,6 +255,7 @@ extern struct frame *frames; /* root frame first */
 extern struct frame *active_frame;
 extern void *instantiation_error;
 extern enum allow_overlap allow_overlap;
+extern int holes_linked;
 
 
 struct inst;