fix(SimpleLocalDefs): thread safe support

src/main/java/soot/toolkits/scalar/SimpleLocalDefs.java

@@ -22,6 +22,7 @@
  * #L%
  */
 
+import com.google.common.collect.Maps;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.BitSet;
@@ -309,7 +310,7 @@ public enum FlowAnalysisMode {
   }
 
   private final LocalDefs def;
-
+  private Map<Local, Integer> localNumberMap;
   /**
    * 
    * @param graph
@@ -337,12 +338,11 @@ public SimpleLocalDefs(UnitGraph graph, FlowAnalysisMode mode) {
     }
 
     // reassign local numbers
-    int[] oldNumbers = assignNumbers(locals);
+    this.localNumberMap = number2index(locals);
 
     this.def = init(graph, locals, mode);
 
-    // restore local numbering
-    restoreNumbers(locals, oldNumbers);
+    this.localNumberMap = null;
 
     if (time) {
       Timers.v().defsTimer.end();
@@ -355,14 +355,13 @@ protected void restoreNumbers(Local[] locals, int[] oldNumbers) {
     }
   }
 
-  protected int[] assignNumbers(Local[] locals) {
+  protected Map<Local, Integer> number2index(Local[] locals) {
     final int N = locals.length;
-    int[] oldNumbers = new int[N];
+    Map<Local, Integer> localNumberMap = Maps.newHashMapWithExpectedSize(N);
     for (int i = 0; i < N; i++) {
-      oldNumbers[i] = locals[i].getNumber();
-      locals[i].setNumber(i);
+      localNumberMap.put(locals[i], i);
     }
-    return oldNumbers;
+    return localNumberMap;
   }
 
   protected LocalDefs init(DirectedGraph<Unit> graph, Local[] locals, FlowAnalysisMode mode) {
@@ -415,7 +414,7 @@ protected LocalDefs init(DirectedGraph<Unit> graph, Local[] locals, FlowAnalysis
 
   // Is protected so that in case we have a smarter implementation we can use it.
   protected int getLocalNumber(Local l) {
-    return l.getNumber();
+    return localNumberMap.get(l);
   }
 
   @Override