From 5e66675c12048adc17f4dfecfc44dec59bd9020d Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Fri, 5 Jan 2018 14:04:32 +0100
Subject: [PATCH] Add tileconnloops.py script

Signed-off-by: Clifford Wolf <clifford@clifford.at>
---
 utils/tileconnloops.py | 82 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 utils/tileconnloops.py

diff --git a/utils/tileconnloops.py b/utils/tileconnloops.py
new file mode 100644
index 00000000..2bfa3685
--- /dev/null
+++ b/utils/tileconnloops.py
@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+#
+# Produces a complete database of wires in the ROI and their connections and tests if each
+# routing node is a tree (i.e. fails with an error when a loop is found).
+
+import os, sys, json
+
+with open("%s/%s/tilegrid.json" % (os.getenv("XRAY_DATABASE_DIR"), os.getenv("XRAY_DATABASE")), "r") as f:
+    tilegrid = json.load(f)["tiles"]
+
+with open("%s/%s/tileconn.json" % (os.getenv("XRAY_DATABASE_DIR"), os.getenv("XRAY_DATABASE")), "r") as f:
+    tileconn = json.load(f)
+
+grid = dict()
+wirepairs = dict()
+remwires = set()
+
+for tilename, tiledata in tilegrid.items():
+    key = (tiledata["grid_x"], tiledata["grid_y"])
+    grid[key] = tilename
+
+def check_tileconn_entry(tilename, tiledata, entry, idx):
+    if idx == 0:
+        otheridx = 1
+        otherxy = (tiledata["grid_x"] + entry["grid_deltas"][0], tiledata["grid_y"] + entry["grid_deltas"][1])
+    else:
+        otheridx = 0
+        otherxy = (tiledata["grid_x"] - entry["grid_deltas"][0], tiledata["grid_y"] - entry["grid_deltas"][1])
+
+    if otherxy not in grid:
+        return
+
+    othertilename = grid[otherxy]
+    othertiledata = tilegrid[othertilename]
+
+    if othertiledata["type"] != entry["tile_types"][otheridx]:
+        return
+
+    print("  Found relevant entry (%s %s %d %d): %s" % (entry["tile_types"][0], entry["tile_types"][1],
+            entry["grid_deltas"][0], entry["grid_deltas"][1], othertilename))
+
+    for pair in entry["wire_pairs"]:
+        wirename = "%s/%s" % (tilename, pair[idx])
+        otherwirename = "%s/%s" % (othertilename, pair[otheridx])
+
+        remwires.add(wirename)
+        remwires.add(otherwirename)
+
+        if wirename not in wirepairs:
+            wirepairs[wirename] = set()
+        wirepairs[wirename].add(otherwirename)
+
+        if otherwirename not in wirepairs:
+            wirepairs[otherwirename] = set()
+        wirepairs[otherwirename].add(wirename)
+
+for tilename, tiledata in tilegrid.items():
+    print("Connecting wires in tile %s." % tilename)
+    for entry in tileconn:
+        if entry["tile_types"][0] == tiledata["type"]:
+            check_tileconn_entry(tilename, tiledata, entry, 0)
+        if entry["tile_types"][1] == tiledata["type"]:
+            check_tileconn_entry(tilename, tiledata, entry, 1)
+
+def check_wire(wire, source):
+    for next_wire in wirepairs[wire]:
+        if next_wire == source:
+            continue
+        print("  %s" % next_wire)
+        if next_wire not in remwires:
+            print("  ** FOUND LOOP IN THIS NODE **")
+            sys.exit(1)
+        remwires.remove(next_wire)
+        check_wire(next_wire, wire)
+
+while len(remwires):
+    wire = remwires.pop()
+    print("Checking %s:" % wire)
+    check_wire(wire, None)
+
+print("NO LOOP FOUND: OK")
+