CFG fix create edges only if nodes != (found by graphviz)

1 files changed, 16 insertions, 8 deletions

diff --git a/vaporize/library/ControlFlowGraph.java b/vaporize/library/ControlFlowGraph.java
index 364cec1..b4c995c 100644
--- a/vaporize/library/ControlFlowGraph.java
+++ b/vaporize/library/ControlFlowGraph.java
@@ -38,16 +38,24 @@ public class ControlFlowGraph {
     }
 
     protected String addEdge(CFGNode source, CFGNode dest) {
-        String ret = String.format("%d -> %d",
-                                   source.getInstruction().sourcePos.line,
-                                   dest.getInstruction().sourcePos.line);
-        MinimalLogger.info(String.format("Edge %s",
-                                         ret));
+        /**
+         * Iff the CFGNodes are different, construct an edge between them.
+         * Returns a string capable of being manipulated by graphviz.
+         */
+        String ret = "";
+        if (!source.equals(dest)) {
+            ret = String.format("%d -> %d",
+                                source.getInstruction().sourcePos.line,
+                                dest.getInstruction().sourcePos.line);
+            MinimalLogger.info(String.format("Edge %s",
+                                             ret));
 
-        source.addDest(dest);
-        dest.addSource(source);
+            source.addDest(dest);
+            dest.addSource(source);
+            ret += ";";
+        }
 
-        return ret +";";
+        return ret;
     }
 
     protected void setStart(CFGNode start) {