Adjusted CallRemover: when call in an assignment is removed, replace result by null

Author: palant

src/info/palant/apkInstrumentation/CallRemover.java

@@ -12,6 +12,8 @@
 import soot.Body;
 import soot.BodyTransformer;
 import soot.SootMethod;
+import soot.jimple.AssignStmt;
+import soot.jimple.NullConstant;
 
 public class CallRemover extends BodyTransformer
 {
@@ -40,7 +42,15 @@ protected void internalTransform(Body body, String phaseName, Map<String, String
 
     body.getUnits().removeIf(unit -> {
       SootMethod method = UnitParser.getInvocationMethod(unit);
-      return method != null && this.methodConfig.get(method) != null;
+      if (method != null && this.methodConfig.get(method) != null)
+      {
+        AssignStmt assignment = UnitParser.getAssignment(unit);
+        if (assignment != null)
+          assignment.setRightOp(NullConstant.v());
+        else
+          return true;
+      }
+      return false;
     });
 
     body.validate();