--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/gov/nasa/jpf/util/SourceRef.java	Fri Jan 23 10:14:01 2015 -0800
@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2014, United States Government, as represented by the
+ * Administrator of the National Aeronautics and Space Administration.
+ * All rights reserved.
+ *
+ * The Java Pathfinder core (jpf-core) platform is licensed under the
+ * Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ *        http://www.apache.org/licenses/LICENSE-2.0. 
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and 
+ * limitations under the License.
+ */
+package gov.nasa.jpf.util;
+
+/**
+ * a source reference abstraction wrapping file and line information
+ */
+public class SourceRef {
+  public String fileName;
+  public int    line;
+
+  public SourceRef (String f, int l) {
+    if (f == null) {
+      fileName = "?";
+    } else {
+      fileName = f;
+    }
+    
+    line = l;
+  }
+
+  public SourceRef (String spec){
+    int idx = spec.indexOf(':');
+    if (idx > 0){
+      fileName = spec.substring(0, idx);
+      line = Integer.parseInt(spec.substring(idx+1));
+    } else {
+      fileName = spec;
+      line = 0;
+    }
+  }
+
+  public String getLocationString() {
+    return (fileName + ':' + line);
+  }
+  
+  public String getLineString () {
+    Source source = Source.getSource(fileName);
+    if (source != null) {
+      return source.getLine(line);
+    } else {
+      return null;
+    }
+  }
+
+  @Override
+  public boolean equals (Object o) {
+    if (o == null) {
+      return false;
+    }
+
+    if (!(o instanceof SourceRef)) {
+      return false;
+    }
+
+    SourceRef that = (SourceRef) o;
+
+    if (this.fileName == null) {
+      return false;
+    }
+
+    if (this.line == -1) {
+      return false;
+    }
+
+    if (!this.fileName.equals(that.fileName)) {
+      return false;
+    }
+
+    if (this.line != that.line) {
+      return false;
+    }
+
+    return true;
+  }
+
+  public boolean equals (String f, int l) {
+    if (fileName == null) {
+      return false;
+    }
+
+    if (line == -1) {
+      return false;
+    }
+
+    if (!fileName.equals(f)) {
+      return false;
+    }
+
+    if (line != l) {
+      return false;
+    }
+
+    return true;
+  }
+
+  public boolean equals (String filePos){
+    if (filePos.startsWith(fileName)){
+      int len = fileName.length();
+      if (filePos.charAt(len) == ':'){
+        if (Integer.parseInt(filePos.substring(len+1)) == line){
+          return true;
+        }
+      }
+    }
+
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    assert false : "hashCode not designed";
+    return 42; // any arbitrary constant will do
+    // thanks, FindBugs!
+  }
+
+  public String getFileName () {
+    return fileName;
+  }
+
+  public void set (SourceRef sr) {
+    fileName = sr.fileName;
+    line = sr.line;
+  }
+
+  @Override
+  public String toString () {
+    return (fileName + ':' + line);
+  }
+}