Two fixes for mapping source positions to IR

1: get the right position for methods from the JDT AST
2: more seriously, there was a nasty bug in how source positions got
mapped in unwound code: mappings were wrong for instructions that
were the result of duplicating code to replicate unwind handling in
exceptional and non-local exits.

com.ibm.wala.cast/source/java/com/ibm/wala/cast/ir/translator/ExposedNamesCollector.java

@@ -5,6 +5,7 @@ import java.util.Set;
 
 import com.ibm.wala.cast.tree.CAstEntity;
 import com.ibm.wala.cast.tree.CAstNode;
+import com.ibm.wala.cast.tree.CAstSourcePositionMap;
 import com.ibm.wala.cast.tree.CAstSymbol;
 import com.ibm.wala.cast.tree.visit.CAstVisitor;
 import com.ibm.wala.util.collections.HashMapFactory;
@@ -41,6 +42,10 @@ public class ExposedNamesCollector extends CAstVisitor<ExposedNamesCollector.Ent
       return top;
     }
 
+    public CAstSourcePositionMap getSourceMap() {
+      return top.getSourceMap();
+    }
+
   }
 
   /**

com.ibm.wala.cast/source/java/com/ibm/wala/cast/tree/visit/CAstVisitor.java

@@ -16,6 +16,7 @@ import java.util.Map;
 
 import com.ibm.wala.cast.tree.CAstEntity;
 import com.ibm.wala.cast.tree.CAstNode;
+import com.ibm.wala.cast.tree.CAstSourcePositionMap;
 import com.ibm.wala.cast.tree.CAstSourcePositionMap.Position;
 import com.ibm.wala.cast.util.CAstPrinter;
 import com.ibm.wala.util.collections.HashMapFactory;
@@ -30,10 +31,14 @@ public abstract class CAstVisitor<C extends CAstVisitor.Context> {
 
   private Position currentPosition;
   
-  protected Position getCurrentPosition() {
+  public Position getCurrentPosition() {
     return currentPosition;
   }
   
+  protected CAstVisitor() {
+    
+  }
+  
   /**
    * This interface represents a visitor-specific context.  All
    * it knows is how to get its top-level entity.  It is expected
@@ -43,7 +48,10 @@ public abstract class CAstVisitor<C extends CAstVisitor.Context> {
    * @author Igor Peshansky
    */
   public interface Context {
+    
     CAstEntity top();
+    
+    CAstSourcePositionMap getSourceMap();
   }
 
   /**
@@ -406,8 +414,8 @@ public abstract class CAstVisitor<C extends CAstVisitor.Context> {
    */
   public final void visit(final CAstNode n, C context, CAstVisitor<C> visitor) {
     Position restore = currentPosition;
-    if (context.top().getSourceMap() != null) {
-      Position p = context.top().getSourceMap().getPosition(n);
+    if (context.getSourceMap() != null) {
+      Position p = context.getSourceMap().getPosition(n);
       if (p != null) {
         currentPosition = p;
       }
@@ -939,7 +947,7 @@ public abstract class CAstVisitor<C extends CAstVisitor.Context> {
 	System.err.println(("cannot handle assign to kind " + n.getKind()));
 	throw new UnsupportedOperationException(
 	  "cannot handle assignment: " + 
-	  CAstPrinter.print(a, context.top().getSourceMap()));
+	  CAstPrinter.print(a, context.getSourceMap()));
       }
     }
     }

com.ibm.wala.cast/source/java/com/ibm/wala/cast/util/CAstPattern.java

@@ -22,6 +22,7 @@ import java.util.regex.Pattern;
 
 import com.ibm.wala.cast.tree.CAstEntity;
 import com.ibm.wala.cast.tree.CAstNode;
+import com.ibm.wala.cast.tree.CAstSourcePositionMap;
 import com.ibm.wala.cast.tree.visit.CAstVisitor;
 import com.ibm.wala.cast.tree.visit.CAstVisitor.Context;
 import com.ibm.wala.util.collections.HashMapFactory;
@@ -394,6 +395,9 @@ public class CAstPattern {
       public CAstEntity top() {
         return e;
       }
+      public CAstSourcePositionMap getSourceMap() {
+        return e.getSourceMap();
+      }
     }, v);
   
     return result;

com.ibm.wala.ide.jdt/source/com/ibm/wala/cast/java/translator/jdt/JDTJava2CAstTranslator.java

@@ -914,7 +914,7 @@ public class JDTJava2CAstTranslator {
     }
 
     public CAstSourcePositionMap.Position getPosition() {
-      return getSourceMap().getPosition(fAst);
+      return fDecl==null? getSourceMap().getPosition(fAst): makePosition(fDecl);
     }
 
     public CAstNodeTypeMap getNodeTypeMap() {