reflection support for java.lang.ClassLoader.loadClass

git-svn-id: https://wala.svn.sourceforge.net/svnroot/wala/trunk@3015 f5eafffb-2e1d-0410-98e4-8ec43c5233c4

com.ibm.wala.core/dat/natives.xml

@@ -272,7 +272,9 @@
 				</method>
 				<method name="findLoadedClass"
 					descriptor="(Ljava/lang/String;)Ljava/lang/Class;">
-					<new def="x" class="Ljava/lang/Class" />
+					<call type="static" name="forName"
+						class="Ljava/lang/Class" descriptor="(Ljava/lang/String;)Ljava/lang/Class;" 
+						arg0="arg0" def="x" />
 					<return value="x" />
 				</method>
 				<method name="getCallerClassLoader"

com.ibm.wala.core/src/com/ibm/wala/analysis/reflection/ClassFactoryContextInterpreter.java

@@ -30,29 +30,17 @@ import com.ibm.wala.ssa.SSALoadClassInstruction;
 import com.ibm.wala.ssa.SSAOptions;
 import com.ibm.wala.ssa.SSAReturnInstruction;
 import com.ibm.wala.ssa.SSAThrowInstruction;
-import com.ibm.wala.types.Descriptor;
 import com.ibm.wala.types.FieldReference;
-import com.ibm.wala.types.MethodReference;
 import com.ibm.wala.types.TypeReference;
 import com.ibm.wala.util.collections.EmptyIterator;
 import com.ibm.wala.util.collections.NonNullSingletonIterator;
 import com.ibm.wala.util.debug.Assertions;
-import com.ibm.wala.util.strings.Atom;
 
 /**
- * An {@link SSAContextInterpreter} specialized to interpret Class.forName in a {@link JavaTypeContext} which
+ * An {@link SSAContextInterpreter} specialized to interpret reflective class factories (e.g. Class.forName()) in a
- * represents the point-type of the class object created by the call.
+ * {@link JavaTypeContext} which represents the point-type of the class object created by the call.
- * 
- * @author pistoia
  */
-public class ForNameContextInterpreter implements SSAContextInterpreter {
+public class ClassFactoryContextInterpreter implements SSAContextInterpreter {
-
-  public final static Atom forNameAtom = Atom.findOrCreateUnicodeAtom("forName");
-
-  private final static Descriptor forNameDescriptor = Descriptor.findOrCreateUTF8("(Ljava/lang/String;)Ljava/lang/Class;");
-
-  public final static MethodReference FOR_NAME_REF = MethodReference.findOrCreate(TypeReference.JavaLangClass, forNameAtom,
-      forNameDescriptor);
 
   private static final boolean DEBUG = false;
 
@@ -77,15 +65,22 @@ public class ForNameContextInterpreter implements SSAContextInterpreter {
     return getIR(node).getInstructions().length;
   }
 
+  /* 
+   * @see com.ibm.wala.ipa.callgraph.propagation.rta.RTAContextInterpreter#understands(com.ibm.wala.ipa.callgraph.CGNode)
+   */
   public boolean understands(CGNode node) {
     if (node == null) {
       throw new IllegalArgumentException("node is null");
     }
-    if (!(node.getContext() instanceof JavaTypeContext))
+    if (!(node.getContext() instanceof JavaTypeContext)) {
       return false;
-    return node.getMethod().getReference().equals(FOR_NAME_REF);
+    }
+    return ClassFactoryContextSelector.isClassFactory(node.getMethod());
   }
 
+  /* 
+   * @see com.ibm.wala.ipa.callgraph.propagation.rta.RTAContextInterpreter#iterateNewSites(com.ibm.wala.ipa.callgraph.CGNode)
+   */
   public Iterator<NewSiteReference> iterateNewSites(CGNode node) {
     if (node == null) {
       throw new IllegalArgumentException("node is null");
@@ -101,6 +96,9 @@ public class ForNameContextInterpreter implements SSAContextInterpreter {
     return EmptyIterator.instance();
   }
 
+  /* 
+   * @see com.ibm.wala.ipa.callgraph.propagation.rta.RTAContextInterpreter#iterateCallSites(com.ibm.wala.ipa.callgraph.CGNode)
+   */
   public Iterator<CallSiteReference> iterateCallSites(CGNode node) {
     if (Assertions.verifyAssertions) {
       Assertions._assert(understands(node));
@@ -108,6 +106,7 @@ public class ForNameContextInterpreter implements SSAContextInterpreter {
     return EmptyIterator.instance();
   }
 
+
   private SSAInstruction[] makeStatements(JavaTypeContext context) {
     ArrayList<SSAInstruction> statements = new ArrayList<SSAInstruction>();
     // vn1 is the string parameter

com.ibm.wala.core/src/com/ibm/wala/analysis/reflection/ClassFactoryContextSelector.java

@@ -22,36 +22,74 @@ import com.ibm.wala.ipa.cha.IClassHierarchy;
 import com.ibm.wala.ssa.IR;
 import com.ibm.wala.ssa.SSAAbstractInvokeInstruction;
 import com.ibm.wala.ssa.SymbolTable;
+import com.ibm.wala.types.ClassLoaderReference;
+import com.ibm.wala.types.Descriptor;
+import com.ibm.wala.types.MethodReference;
 import com.ibm.wala.types.TypeReference;
+import com.ibm.wala.util.strings.Atom;
 import com.ibm.wala.util.strings.StringStuff;
 
 /**
- * A {@link ContextSelector} to intercept calls to Class.forName() when the parameter is a string constant
+ * A {@link ContextSelector} to intercept calls to reflective class factories (e.g. Class.forName()) when the parameter is a string
- * 
+ * constant
- * @author pistoia
  */
-class ForNameContextSelector implements ContextSelector {
+class ClassFactoryContextSelector implements ContextSelector {
 
-  public ForNameContextSelector() {
+  public final static Atom forNameAtom = Atom.findOrCreateUnicodeAtom("forName");
+
+  private final static Descriptor forNameDescriptor = Descriptor.findOrCreateUTF8("(Ljava/lang/String;)Ljava/lang/Class;");
+
+  public final static MethodReference FOR_NAME_REF = MethodReference.findOrCreate(TypeReference.JavaLangClass, forNameAtom,
+      forNameDescriptor);
+
+  public final static Atom loadClassAtom = Atom.findOrCreateUnicodeAtom("loadClass");
+
+  private final static Descriptor loadClassDescriptor = Descriptor.findOrCreateUTF8("(Ljava/lang/String;)Ljava/lang/Class;");
+
+  private final static TypeReference CLASSLOADER = TypeReference.findOrCreate(ClassLoaderReference.Primordial,
+      "Ljava/lang/ClassLoader");
+
+  public final static MethodReference LOAD_CLASS_REF = MethodReference
+      .findOrCreate(CLASSLOADER, loadClassAtom, loadClassDescriptor);
+
+  public ClassFactoryContextSelector() {
+  }
+
+  public static boolean isClassFactory(IMethod m) {
+    if (m.getReference().equals(FOR_NAME_REF)) {
+      return true;
+    }
+    if (m.getReference().equals(LOAD_CLASS_REF)) {
+      return true;
+    }
+    return false;
+  }
+
+  public int getUseOfStringParameter(SSAAbstractInvokeInstruction call) {
+    if (call.isStatic()) {
+      return call.getUse(0);
+    } else {
+      return call.getUse(1);
+    }
   }
 
   /**
-   * If the {@link CallSiteReference} invokes Class.forName(s) and s is a string constant, return a
+   * If the {@link CallSiteReference} invokes Class.forName(s) and s is a string constant, return a {@link JavaTypeContext}
-   * {@link JavaTypeContext} representing the type named by s, if we can resolve it in the {@link IClassHierarchy}.
+   * representing the type named by s, if we can resolve it in the {@link IClassHierarchy}.
    * 
    * @see com.ibm.wala.ipa.callgraph.ContextSelector#getCalleeTarget(com.ibm.wala.ipa.callgraph.CGNode,
    *      com.ibm.wala.classLoader.CallSiteReference, com.ibm.wala.classLoader.IMethod,
    *      com.ibm.wala.ipa.callgraph.propagation.InstanceKey)
    */
   public Context getCalleeTarget(CGNode caller, CallSiteReference site, IMethod callee, InstanceKey receiver) {
-    if (callee.getReference().equals(ForNameContextInterpreter.FOR_NAME_REF)) {
+    if (isClassFactory(callee)) {
       IR ir = caller.getIR();
       SymbolTable symbolTable = ir.getSymbolTable();
       SSAAbstractInvokeInstruction[] invokeInstructions = caller.getIR().getCalls(site);
       if (invokeInstructions.length != 1) {
         return null;
       }
-      int use = invokeInstructions[0].getUse(0);
+      int use = getUseOfStringParameter(invokeInstructions[0]);
       if (symbolTable.isStringConstant(use)) {
         String className = StringStuff.deployment2CanonicalTypeString(symbolTable.getStringValue(use));
         TypeReference t = TypeReference.findOrCreate(caller.getMethod().getDeclaringClass().getClassLoader().getReference(),
@@ -69,14 +107,14 @@ class ForNameContextSelector implements ContextSelector {
    * This object may understand a dispatch to Class.forName(s) when s is a string constant.
    */
   public boolean mayUnderstand(CGNode caller, CallSiteReference site, IMethod targetMethod, InstanceKey instance) {
-    if (targetMethod.getReference().equals(ForNameContextInterpreter.FOR_NAME_REF)) {
+    if (isClassFactory(targetMethod)) {
       IR ir = caller.getIR();
       SymbolTable symbolTable = ir.getSymbolTable();
       SSAAbstractInvokeInstruction[] invokeInstructions = caller.getIR().getCalls(site);
       if (invokeInstructions.length != 1) {
         return false;
       }
-      int use = invokeInstructions[0].getUse(0);
+      int use = getUseOfStringParameter(invokeInstructions[0]);
       if (symbolTable.isStringConstant(use)) {
         return true;
       }

com.ibm.wala.core/src/com/ibm/wala/analysis/reflection/ReflectionContextInterpreter.java

@@ -34,7 +34,7 @@ public class ReflectionContextInterpreter extends DelegatingSSAContextInterprete
       ReflectionSpecification userSpec) {
     super(new ReflectiveInvocationInterpreter(), new DelegatingSSAContextInterpreter(new DelegatingSSAContextInterpreter(
         new GetClassContextInterpeter(), new JavaLangClassContextInterpreter()), new DelegatingSSAContextInterpreter(
-        new DelegatingSSAContextInterpreter(new ForNameContextInterpreter(), new ClassNewInstanceContextInterpreter(cha)),
+        new DelegatingSSAContextInterpreter(new ClassFactoryContextInterpreter(), new ClassNewInstanceContextInterpreter(cha)),
         new FactoryBypassInterpreter(options, cache, userSpec))));
   }
 

com.ibm.wala.core/src/com/ibm/wala/analysis/reflection/ReflectionContextSelector.java

@@ -31,7 +31,7 @@ public class ReflectionContextSelector extends DelegatingContextSelector {
    */
   private ReflectionContextSelector() {
     super(new ReflectiveInvocationSelector(), new DelegatingContextSelector(new JavaLangClassContextSelector(),
-        new DelegatingContextSelector(new DelegatingContextSelector(new DelegatingContextSelector(new ForNameContextSelector(),
+        new DelegatingContextSelector(new DelegatingContextSelector(new DelegatingContextSelector(new ClassFactoryContextSelector(),
             new GetClassContextSelector()), new ClassNewInstanceContextSelector()), new FactoryContextSelector())));
   }