fix for bug reported by Juergen Graf: handle multiple fields with the same name in a JVM class

git-svn-id: https://wala.svn.sourceforge.net/svnroot/wala/trunk@4552 f5eafffb-2e1d-0410-98e4-8ec43c5233c4

com.ibm.wala.cast/source/java/com/ibm/wala/cast/loader/AstClass.java

@@ -153,6 +153,10 @@ abstract public class AstClass implements IClass, ClassConstants {
     }
   }
 
+  public IField getField(Atom name, TypeName type) {
+    // assume that for AST classes, you can't have multiple fields with the same name
+    return getField(name);
+  }
   public Collection<IMethod> getDeclaredMethods() {
     return declaredMethods.values();
   }

com.ibm.wala.cast/source/java/com/ibm/wala/cast/loader/AstFunctionClass.java

@@ -117,6 +117,11 @@ abstract public class AstFunctionClass implements IClass, ClassConstants {
     return loader.lookupClass(superReference.getName()).getField(name);
   }
 
+  public IField getField(Atom name, TypeName type) {
+    // assume that for AST classes, you can't have multiple fields with the same name    
+    return loader.lookupClass(superReference.getName()).getField(name);
+  }
+
   public TypeReference getReference() {
     return reference;
   }

com.ibm.wala.core.testdata/build.xml

@@ -152,6 +152,9 @@
 		<copy todir="${destination.temp.folder}/com.ibm.wala.core.testdata_1.0.0" failonerror="true" overwrite="false">
 			<fileset dir="${basedir}" includes="META-INF/"			/>
 		</copy>
+		<copy todir="${destination.temp.folder}/com.ibm.wala.core.testdata_1.0.0" failonerror="true" overwrite="false">
+			<fileset dir="${basedir}/classes" includes="**"			/>
+		</copy>
 	</target>
 
 	<target name="build.zips" depends="init">

com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/cha/DupFieldsTest.java

@@ -0,0 +1,51 @@
+/*******************************************************************************
+ * Copyright (c) 2008 IBM Corporation.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package com.ibm.wala.core.tests.cha;
+
+import java.io.IOException;
+
+import junit.framework.Assert;
+
+import org.junit.Test;
+
+import com.ibm.wala.classLoader.IClass;
+import com.ibm.wala.classLoader.IField;
+import com.ibm.wala.core.tests.util.TestConstants;
+import com.ibm.wala.core.tests.util.WalaTestCase;
+import com.ibm.wala.ipa.callgraph.AnalysisScope;
+import com.ibm.wala.ipa.cha.ClassHierarchy;
+import com.ibm.wala.ipa.cha.ClassHierarchyException;
+import com.ibm.wala.types.ClassLoaderReference;
+import com.ibm.wala.types.TypeReference;
+import com.ibm.wala.util.config.AnalysisScopeReader;
+import com.ibm.wala.util.io.FileProvider;
+import com.ibm.wala.util.strings.Atom;
+
+public class DupFieldsTest extends WalaTestCase {
+
+  @Test public void testDupFieldNames() throws IOException, ClassHierarchyException {
+    AnalysisScope scope = null;
+    scope = AnalysisScopeReader.readJavaScope(TestConstants.WALA_TESTDATA, FileProvider.getFile("J2SEClassHierarchyExclusions.txt"), DupFieldsTest.class.getClassLoader());
+    ClassHierarchy cha = ClassHierarchy.make(scope);
+    IClass klass = cha.lookupClass(TypeReference.findOrCreate(ClassLoaderReference.Application, "LDupFieldName"));
+    boolean threwException = false;
+    try {
+      klass.getField(Atom.findOrCreateUnicodeAtom("a"));
+    } catch (IllegalStateException e) {
+      threwException = true;
+    }
+    Assert.assertTrue(threwException);
+    IField f = klass.getField(Atom.findOrCreateUnicodeAtom("a"), TypeReference.IntName);
+    Assert.assertEquals(f.getFieldTypeReference(), TypeReference.Int);
+    f = klass.getField(Atom.findOrCreateUnicodeAtom("a"), TypeReference.BooleanName);
+    Assert.assertEquals(f.getFieldTypeReference(), TypeReference.Boolean);
+  }
+}

com.ibm.wala.core/src/com/ibm/wala/classLoader/ArrayClass.java

@@ -129,6 +129,10 @@ public class ArrayClass implements IClass, Constants {
     return getSuperclass().getField(name);
   }
 
+  public IField getField(Atom name, TypeName typeName) {
+    return getSuperclass().getField(name, typeName);
+  } 
+
   /*
    * @see com.ibm.wala.classLoader.IClass#getDeclaredMethods()
    */

com.ibm.wala.core/src/com/ibm/wala/classLoader/BytecodeClass.java

@@ -121,7 +121,7 @@ public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
   protected int hashCode;
 
   private final HashMap<Atom, IField> fieldMap = HashMapFactory.make(5);
-
+  
   /**
    * A warning for when we get a class not found exception
    */
@@ -192,12 +192,17 @@ public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
     if (fieldMap.containsKey(name)) {
       return fieldMap.get(name);
     } else {
-      IField f = findDeclaredField(name);
-      if (f != null) {
-        fieldMap.put(name, f);
-        return f;
+      List<IField> fields = findDeclaredField(name);
+      if (!fields.isEmpty()) {
+        if (fields.size() == 1) {
+          IField f = fields.iterator().next();
+          fieldMap.put(name, f);
+          return f;
+        } else {
+          throw new IllegalStateException("multiple fields with name " + name);
+        }
       } else if ((superClass = getSuperclass()) != null) {
-        f = superClass.getField(name);
+        IField f = superClass.getField(name);
         if (f != null) {
           fieldMap.put(name, f);
           return f;
@@ -205,7 +210,7 @@ public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
       }
       // try superinterfaces
       for (IClass i : getAllImplementedInterfaces()) {
-        f = i.getField(name);
+        IField f = i.getField(name);
         if (f != null) {
           fieldMap.put(name, f);
           return f;
@@ -216,6 +221,43 @@ public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
     return null;
   }
 
+  
+  public IField getField(Atom name, TypeName type) {
+    try {
+      // typically, there will be at most one field with the name
+      IField field = getField(name);
+      if (field != null && field.getFieldTypeReference().getName().equals(type)) {
+        return field;
+      } else {
+        return null;
+      }
+    } catch (IllegalStateException e) {
+      assert e.getMessage().startsWith("multiple fields with");
+      // multiple fields.  look through all of them and see if any have the appropriate type
+      List<IField> fields = findDeclaredField(name);
+      for (IField f : fields) {
+        if (f.getFieldTypeReference().getName().equals(type)) {
+          return f;
+        }
+      }
+      // check superclass
+      if (getSuperclass() != null) {
+        IField f = superClass.getField(name, type);
+        if (f != null) {
+          return f;
+        }
+      }
+      // try superinterfaces
+      for (IClass i : getAllImplementedInterfaces()) {
+        IField f = i.getField(name, type);
+        if (f != null) {
+          return f;
+        }
+      }
+    }
+    return null;
+  }
+
   private void computeSuperclass() {
     superclassComputed = true;
 
@@ -466,11 +508,14 @@ public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
     return result;
   }
 
-  protected IField findDeclaredField(Atom name) {
+  protected List<IField> findDeclaredField(Atom name) {
+    
+    List<IField> result = new ArrayList<IField>(1);
+    
     if (instanceFields != null) {
       for (int i = 0; i < instanceFields.length; i++) {
         if (instanceFields[i].getName() == name) {
-          return instanceFields[i];
+          result.add(instanceFields[i]);
         }
       }
     }
@@ -478,12 +523,12 @@ public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
     if (staticFields != null) {
       for (int i = 0; i < staticFields.length; i++) {
         if (staticFields[i].getName() == name) {
-          return staticFields[i];
+          result.add(staticFields[i]);
         }
       }
     }
 
-    return null;
+    return result;
   }
 
   protected void addFieldToList(List<FieldImpl> L, Atom name, ImmutableByteArray fieldType, int accessFlags,

com.ibm.wala.core/src/com/ibm/wala/classLoader/IClass.java

@@ -88,9 +88,16 @@ public interface IClass extends IClassHierarchyDweller {
 
   /**
    * Finds a field.
+   * 
+   * @throws IllegalStateException if the class contains multiple fields with name <code>name</code>.
    */
   IField getField(Atom name);
 
+  /**
+   * Finds a field, given a name and a type.  Returns <code>null</code> if not found.
+   */
+  IField getField(Atom name, TypeName type);
+  
   /**
    * @return canonical TypeReference corresponding to this class
    */

com.ibm.wala.core/src/com/ibm/wala/classLoader/SyntheticClass.java

@@ -17,6 +17,7 @@ import com.ibm.wala.ipa.cha.IClassHierarchy;
 import com.ibm.wala.types.ClassLoaderReference;
 import com.ibm.wala.types.TypeName;
 import com.ibm.wala.types.TypeReference;
+import com.ibm.wala.util.strings.Atom;
 
 /**
  * An {@link IClass} that exists nowhere in bytecode.
@@ -121,4 +122,11 @@ public abstract class SyntheticClass implements IClass {
   public TypeName getName() {
     return getReference().getName();
   }
+
+  /**
+   * we assume synthetic classes do not need to have multiple fields with the same name.  
+   */
+  public IField getField(Atom name, TypeName typeName) {
+    return getField(name);
+  }
 }