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A Java Optimization Framework
package soot.dexpler;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 2012 Michael Markert, Frank Hartmann
*
* (c) 2012 University of Luxembourg - Interdisciplinary Centre for
* Security Reliability and Trust (SnT) - All rights reserved
* Alexandre Bartel
*
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 2.1 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import static soot.dexpler.instructions.InstructionFactory.fromInstruction;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.jf.dexlib2.analysis.ClassPath;
import org.jf.dexlib2.analysis.ClassPathResolver;
import org.jf.dexlib2.analysis.ClassProvider;
import org.jf.dexlib2.dexbacked.DexBackedDexFile;
import org.jf.dexlib2.iface.DexFile;
import org.jf.dexlib2.iface.ExceptionHandler;
import org.jf.dexlib2.iface.Method;
import org.jf.dexlib2.iface.MethodImplementation;
import org.jf.dexlib2.iface.MethodParameter;
import org.jf.dexlib2.iface.TryBlock;
import org.jf.dexlib2.iface.debug.DebugItem;
import org.jf.dexlib2.iface.instruction.Instruction;
import org.jf.dexlib2.immutable.debug.ImmutableLineNumber;
import org.jf.dexlib2.util.MethodUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import soot.Body;
import soot.DoubleType;
import soot.Local;
import soot.LongType;
import soot.Modifier;
import soot.NullType;
import soot.PackManager;
import soot.PhaseOptions;
import soot.PrimType;
import soot.RefType;
import soot.Scene;
import soot.SootClass;
import soot.SootMethod;
import soot.Trap;
import soot.Type;
import soot.Unit;
import soot.UnknownType;
import soot.Value;
import soot.ValueBox;
import soot.dexpler.instructions.DanglingInstruction;
import soot.dexpler.instructions.DeferableInstruction;
import soot.dexpler.instructions.DexlibAbstractInstruction;
import soot.dexpler.instructions.MoveExceptionInstruction;
import soot.dexpler.instructions.OdexInstruction;
import soot.dexpler.instructions.PseudoInstruction;
import soot.dexpler.instructions.RetypeableInstruction;
import soot.dexpler.typing.DalvikTyper;
import soot.jimple.AssignStmt;
import soot.jimple.CastExpr;
import soot.jimple.CaughtExceptionRef;
import soot.jimple.ConditionExpr;
import soot.jimple.Constant;
import soot.jimple.DefinitionStmt;
import soot.jimple.EqExpr;
import soot.jimple.IfStmt;
import soot.jimple.IntConstant;
import soot.jimple.Jimple;
import soot.jimple.JimpleBody;
import soot.jimple.NeExpr;
import soot.jimple.NullConstant;
import soot.jimple.NumericConstant;
import soot.jimple.internal.JIdentityStmt;
import soot.jimple.toolkits.base.Aggregator;
import soot.jimple.toolkits.scalar.ConditionalBranchFolder;
import soot.jimple.toolkits.scalar.ConstantCastEliminator;
import soot.jimple.toolkits.scalar.CopyPropagator;
import soot.jimple.toolkits.scalar.DeadAssignmentEliminator;
import soot.jimple.toolkits.scalar.FieldStaticnessCorrector;
import soot.jimple.toolkits.scalar.IdentityCastEliminator;
import soot.jimple.toolkits.scalar.IdentityOperationEliminator;
import soot.jimple.toolkits.scalar.MethodStaticnessCorrector;
import soot.jimple.toolkits.scalar.NopEliminator;
import soot.jimple.toolkits.scalar.UnreachableCodeEliminator;
import soot.jimple.toolkits.typing.TypeAssigner;
import soot.options.JBOptions;
import soot.options.Options;
import soot.tagkit.LineNumberTag;
import soot.tagkit.SourceLineNumberTag;
import soot.toolkits.exceptions.TrapTightener;
import soot.toolkits.scalar.LocalPacker;
import soot.toolkits.scalar.LocalSplitter;
import soot.toolkits.scalar.UnusedLocalEliminator;
/**
* A DexBody contains the code of a DexMethod and is used as a wrapper around JimpleBody in the jimplification process.
*
* @author Michael Markert
* @author Frank Hartmann
*/
public class DexBody {
private static final Logger logger = LoggerFactory.getLogger(DexBody.class);
protected List instructions;
// keeps track about the jimple locals that are associated with the dex
// registers
protected Local[] registerLocals;
protected Local storeResultLocal;
protected Map instructionAtAddress;
protected List deferredInstructions;
protected Set instructionsToRetype;
protected DanglingInstruction dangling;
protected int numRegisters;
protected int numParameterRegisters;
protected final List parameterTypes;
protected final List parameterNames;
protected boolean isStatic;
protected JimpleBody jBody;
protected List> tries;
protected RefType declaringClassType;
protected final DexFile dexFile;
protected final Method method;
// detect array/instructions overlapping obfuscation
protected List pseudoInstructionData = new ArrayList();
PseudoInstruction isAddressInData(int a) {
for (PseudoInstruction pi : pseudoInstructionData) {
int fb = pi.getDataFirstByte();
int lb = pi.getDataLastByte();
if (fb <= a && a <= lb) {
return pi;
}
}
return null;
}
/**
* @param code
* the codeitem that is contained in this body
* @param method
* the method that is associated with this body
*/
protected DexBody(DexFile dexFile, Method method, RefType declaringClassType) {
MethodImplementation code = method.getImplementation();
if (code == null) {
throw new RuntimeException("error: no code for method " + method.getName());
}
this.declaringClassType = declaringClassType;
tries = code.getTryBlocks();
List parameters = method.getParameters();
if (parameters != null) {
parameterNames = new ArrayList();
parameterTypes = new ArrayList();
for (MethodParameter param : method.getParameters()) {
parameterNames.add(param.getName());
parameterTypes.add(DexType.toSoot(param.getType()));
}
} else {
parameterNames = Collections.emptyList();
parameterTypes = Collections.emptyList();
}
isStatic = Modifier.isStatic(method.getAccessFlags());
numRegisters = code.getRegisterCount();
numParameterRegisters = MethodUtil.getParameterRegisterCount(method);
if (!isStatic) {
numParameterRegisters--;
}
instructions = new ArrayList();
instructionAtAddress = new HashMap();
registerLocals = new Local[numRegisters];
extractDexInstructions(code);
// Check taken from Android's dalvik/libdex/DexSwapVerify.cpp
if (numParameterRegisters > numRegisters) {
throw new RuntimeException(
"Malformed dex file: insSize (" + numParameterRegisters + ") > registersSize (" + numRegisters + ")");
}
for (DebugItem di : code.getDebugItems()) {
if (di instanceof ImmutableLineNumber) {
ImmutableLineNumber ln = (ImmutableLineNumber) di;
DexlibAbstractInstruction ins = instructionAtAddress(ln.getCodeAddress());
if (ins == null) {
// Debug.printDbg("Line number tag pointing to invalid
// offset: " + ln.getCodeAddress());
continue;
}
ins.setLineNumber(ln.getLineNumber());
}
}
this.dexFile = dexFile;
this.method = method;
}
/**
* Extracts the list of dalvik instructions from dexlib and converts them into our own instruction data model
*
* @param code
* The dexlib method implementation
*/
protected void extractDexInstructions(MethodImplementation code) {
int address = 0;
for (Instruction instruction : code.getInstructions()) {
DexlibAbstractInstruction dexInstruction = fromInstruction(instruction, address);
instructions.add(dexInstruction);
instructionAtAddress.put(address, dexInstruction);
address += instruction.getCodeUnits();
}
}
/**
* Return the types that are used in this body.
*/
public Set usedTypes() {
Set types = new HashSet();
for (DexlibAbstractInstruction i : instructions) {
types.addAll(i.introducedTypes());
}
if (tries != null) {
for (TryBlock tryItem : tries) {
List hList = tryItem.getExceptionHandlers();
for (ExceptionHandler handler : hList) {
String exType = handler.getExceptionType();
if (exType == null) {
// Exceptions
continue;
}
types.add(DexType.toSoot(exType));
}
}
}
return types;
}
/**
* Add unit to this body.
*
* @param u
* Unit to add.
*/
public void add(Unit u) {
getBody().getUnits().add(u);
}
/**
* Add a deferred instruction to this body.
*
* @param i
* the deferred instruction.
*/
public void addDeferredJimplification(DeferableInstruction i) {
deferredInstructions.add(i);
}
/**
* Add a retypeable instruction to this body.
*
* @param i
* the retypeable instruction.
*/
public void addRetype(RetypeableInstruction i) {
instructionsToRetype.add(i);
}
/**
* Return the associated JimpleBody.
*
* @throws RuntimeException
* if no jimplification happened yet.
*/
public Body getBody() {
if (jBody == null) {
throw new RuntimeException("No jimplification happened yet, no body available.");
}
return jBody;
}
/**
* Return the Locals that are associated with the current register state.
*
*/
public Local[] getRegisterLocals() {
return registerLocals;
}
/**
* Return the Local that are associated with the number in the current register state.
*
* Handles if the register number actually points to a method parameter.
*
* @param num
* the register number
* @throws InvalidDalvikBytecodeException
*/
public Local getRegisterLocal(int num) throws InvalidDalvikBytecodeException {
int totalRegisters = registerLocals.length;
if (num > totalRegisters) {
throw new InvalidDalvikBytecodeException(
"Trying to access register " + num + " but only " + totalRegisters + " is/are available.");
}
return registerLocals[num];
}
public Local getStoreResultLocal() {
return storeResultLocal;
}
/**
* Return the instruction that is present at the byte code address.
*
* @param address
* the byte code address.
* @throws RuntimeException
* if address is not part of this body.
*/
public DexlibAbstractInstruction instructionAtAddress(int address) {
DexlibAbstractInstruction i = null;
while (i == null && address >= 0) {
// catch addresses can be in the middlde of last instruction. Ex. in
// com.letang.ldzja.en.apk:
//
// 042c46: 7020 2a15 0100 |008f: invoke-direct {v1, v0},
// Ljavax/mi...
// 042c4c: 2701 |0092: throw v1
// catches : 4
// -> 0x0065
// 0x0069 - 0x0093
//
// SA, 14.05.2014: We originally scanned only two code units back.
// This is not sufficient
// if we e.g., have a wide constant and the line number in the debug
// sections points to
// some address the middle.
i = instructionAtAddress.get(address);
address--;
}
return i;
}
/**
* Return the jimple equivalent of this body.
*
* @param m
* the SootMethod that contains this body
*/
public Body jimplify(Body b, SootMethod m) {
final Jimple jimple = Jimple.v();
final UnknownType unknownType = UnknownType.v();
final NullConstant nullConstant = NullConstant.v();
final Options options = Options.v();
/*
* Timer t_whole_jimplification = new Timer(); Timer t_num = new Timer(); Timer t_null = new Timer();
*
* t_whole_jimplification.start();
*/
JBOptions jbOptions = new JBOptions(PhaseOptions.v().getPhaseOptions("jb"));
jBody = (JimpleBody) b;
deferredInstructions = new ArrayList();
instructionsToRetype = new HashSet();
if (jbOptions.use_original_names()) {
PhaseOptions.v().setPhaseOptionIfUnset("jb.lns", "only-stack-locals");
}
if (jbOptions.stabilize_local_names()) {
PhaseOptions.v().setPhaseOption("jb.lns", "sort-locals:true");
}
if (IDalvikTyper.ENABLE_DVKTYPER) {
DalvikTyper.v().clear();
}
// process method parameters and generate Jimple locals from Dalvik
// registers
List paramLocals = new LinkedList();
if (!isStatic) {
int thisRegister = numRegisters - numParameterRegisters - 1;
Local thisLocal = jimple.newLocal("$u" + thisRegister, unknownType); // generateLocal(UnknownType.v());
jBody.getLocals().add(thisLocal);
registerLocals[thisRegister] = thisLocal;
JIdentityStmt idStmt = (JIdentityStmt) jimple.newIdentityStmt(thisLocal, jimple.newThisRef(declaringClassType));
add(idStmt);
paramLocals.add(thisLocal);
if (IDalvikTyper.ENABLE_DVKTYPER) {
DalvikTyper.v().setType(idStmt.leftBox, jBody.getMethod().getDeclaringClass().getType(), false);
}
}
{
int i = 0; // index of parameter type
int argIdx = 0;
int parameterRegister = numRegisters - numParameterRegisters; // index of parameter register
for (Type t : parameterTypes) {
String localName = null;
Type localType = null;
if (jbOptions.use_original_names()) {
// Attempt to read original parameter name.
try {
localName = parameterNames.get(argIdx);
localType = parameterTypes.get(argIdx);
} catch (Exception ex) {
logger.error("Exception while reading original parameter names.", ex);
}
}
if (localName == null) {
localName = "$u" + parameterRegister;
}
if (localType == null) {
// may only use UnknownType here because the local may be
// reused with a different type later (before splitting)
localType = unknownType;
}
Local gen = jimple.newLocal(localName, localType);
jBody.getLocals().add(gen);
registerLocals[parameterRegister] = gen;
JIdentityStmt idStmt = (JIdentityStmt) jimple.newIdentityStmt(gen, jimple.newParameterRef(t, i++));
add(idStmt);
paramLocals.add(gen);
if (IDalvikTyper.ENABLE_DVKTYPER) {
DalvikTyper.v().setType(idStmt.leftBox, t, false);
}
// some parameters may be encoded on two registers.
// in Jimple only the first Dalvik register name is used
// as the corresponding Jimple Local name. However, we also add
// the second register to the registerLocals array since it
// could be used later in the Dalvik bytecode
if (t instanceof LongType || t instanceof DoubleType) {
parameterRegister++;
// may only use UnknownType here because the local may be reused with a different
// type later (before splitting)
Local g = jimple.newLocal("$u" + parameterRegister, unknownType);
jBody.getLocals().add(g);
registerLocals[parameterRegister] = g;
}
parameterRegister++;
argIdx++;
}
}
for (int i = 0; i < (numRegisters - numParameterRegisters - (isStatic ? 0 : 1)); i++) {
registerLocals[i] = jimple.newLocal("$u" + i, unknownType);
jBody.getLocals().add(registerLocals[i]);
}
// add local to store intermediate results
storeResultLocal = jimple.newLocal("$u-1", unknownType);
jBody.getLocals().add(storeResultLocal);
// process bytecode instructions
final boolean isOdex = dexFile instanceof DexBackedDexFile ? ((DexBackedDexFile) dexFile).isOdexFile() : false;
ClassPath cp = null;
if (isOdex) {
String[] sootClasspath = options.soot_classpath().split(File.pathSeparator);
List classpathList = new ArrayList();
for (String str : sootClasspath) {
classpathList.add(str);
}
try {
ClassPathResolver resolver = new ClassPathResolver(classpathList, classpathList, classpathList, dexFile);
cp = new ClassPath(resolver.getResolvedClassProviders().toArray(new ClassProvider[0]));
} catch (IOException e) {
throw new RuntimeException(e);
}
}
int prevLineNumber = -1;
for (DexlibAbstractInstruction instruction : instructions) {
if (isOdex && instruction instanceof OdexInstruction) {
((OdexInstruction) instruction).deOdex(dexFile, method, cp);
}
if (dangling != null) {
dangling.finalize(this, instruction);
dangling = null;
}
instruction.jimplify(this);
if (instruction.getLineNumber() > 0) {
prevLineNumber = instruction.getLineNumber();
} else {
instruction.setLineNumber(prevLineNumber);
}
}
if (dangling != null) {
dangling.finalize(this, null);
}
for (DeferableInstruction instruction : deferredInstructions) {
instruction.deferredJimplify(this);
}
if (tries != null) {
addTraps();
}
if (options.keep_line_number()) {
fixLineNumbers();
}
// At this point Jimple code is generated
// Cleaning...
instructions = null;
// registerLocals = null;
// storeResultLocal = null;
instructionAtAddress.clear();
// localGenerator = null;
deferredInstructions = null;
// instructionsToRetype = null;
dangling = null;
tries = null;
parameterNames.clear();
/*
* We eliminate dead code. Dead code has been shown to occur under the following circumstances.
*
* 0006ec: 0d00 |00a2: move-exception v0 ... 0006f2: 0d00 |00a5: move-exception v0 ... 0x0041 - 0x008a
* Ljava/lang/Throwable; -> 0x00a5 -> 0x00a2
*
* Here there are two traps both over the same region. But the same always fires, hence rendering the code at a2
* unreachable. Dead code yields problems during local splitting because locals within dead code will not be split. Hence
* we remove all dead code here.
*/
// Fix traps that do not catch exceptions
DexTrapStackFixer.v().transform(jBody);
// Sort out jump chains
DexJumpChainShortener.v().transform(jBody);
// Make sure that we don't have any overlapping uses due to returns
DexReturnInliner.v().transform(jBody);
// Shortcut: Reduce array initializations
DexArrayInitReducer.v().transform(jBody);
// split first to find undefined uses
getLocalSplitter().transform(jBody);
// Remove dead code and the corresponding locals before assigning types
getUnreachableCodeEliminator().transform(jBody);
DeadAssignmentEliminator.v().transform(jBody);
UnusedLocalEliminator.v().transform(jBody);
for (RetypeableInstruction i : instructionsToRetype) {
i.retype(jBody);
}
// {
// // remove instructions from instructions list
// List iToRemove = new
// ArrayList();
// for (DexlibAbstractInstruction i: instructions)
// if (!jBody.getUnits().contains(i.getUnit()))
// iToRemove.add(i);
// for (DexlibAbstractInstruction i: iToRemove) {
// Debug.printDbg("removing dexinstruction containing unit '",
// i.getUnit() ,"'");
// instructions.remove(i);
// }
// }
if (IDalvikTyper.ENABLE_DVKTYPER) {
DexReturnValuePropagator.v().transform(jBody);
getCopyPopagator().transform(jBody);
DexNullThrowTransformer.v().transform(jBody);
DalvikTyper.v().typeUntypedConstrantInDiv(jBody);
DeadAssignmentEliminator.v().transform(jBody);
UnusedLocalEliminator.v().transform(jBody);
DalvikTyper.v().assignType(jBody);
// jBody.validate();
jBody.validateUses();
jBody.validateValueBoxes();
// jBody.checkInit();
// Validate.validateArrays(jBody);
// jBody.checkTypes();
// jBody.checkLocals();
} else {
// t_num.start();
DexNumTransformer.v().transform(jBody);
// t_num.end();
DexReturnValuePropagator.v().transform(jBody);
getCopyPopagator().transform(jBody);
DexNullThrowTransformer.v().transform(jBody);
// t_null.start();
DexNullTransformer.v().transform(jBody);
// t_null.end();
DexIfTransformer.v().transform(jBody);
DeadAssignmentEliminator.v().transform(jBody);
UnusedLocalEliminator.v().transform(jBody);
// DexRefsChecker.v().transform(jBody);
DexNullArrayRefTransformer.v().transform(jBody);
}
if (IDalvikTyper.ENABLE_DVKTYPER) {
for (Local l : jBody.getLocals()) {
l.setType(unknownType);
}
}
// Remove "instanceof" checks on the null constant
DexNullInstanceofTransformer.v().transform(jBody);
TypeAssigner.v().transform(jBody);
final RefType objectType = RefType.v("java.lang.Object");
if (IDalvikTyper.ENABLE_DVKTYPER) {
for (Unit u : jBody.getUnits()) {
if (u instanceof IfStmt) {
ConditionExpr expr = (ConditionExpr) ((IfStmt) u).getCondition();
if (((expr instanceof EqExpr) || (expr instanceof NeExpr))) {
Value op1 = expr.getOp1();
Value op2 = expr.getOp2();
if (op1 instanceof Constant && op2 instanceof Local) {
Local l = (Local) op2;
Type ltype = l.getType();
if (ltype instanceof PrimType) {
continue;
}
if (!(op1 instanceof IntConstant)) {
// null is
// IntConstant(0)
// in Dalvik
continue;
}
IntConstant icst = (IntConstant) op1;
int val = icst.value;
if (val != 0) {
continue;
}
expr.setOp1(nullConstant);
} else if (op1 instanceof Local && op2 instanceof Constant) {
Local l = (Local) op1;
Type ltype = l.getType();
if (ltype instanceof PrimType) {
continue;
}
if (!(op2 instanceof IntConstant)) {
// null is
// IntConstant(0)
// in Dalvik
continue;
}
IntConstant icst = (IntConstant) op2;
int val = icst.value;
if (val != 0) {
continue;
}
expr.setOp2(nullConstant);
} else if (op1 instanceof Local && op2 instanceof Local) {
// nothing to do
} else if (op1 instanceof Constant && op2 instanceof Constant) {
if (op1 instanceof NullConstant && op2 instanceof NumericConstant) {
IntConstant nc = (IntConstant) op2;
if (nc.value != 0) {
throw new RuntimeException("expected value 0 for int constant. Got " + expr);
}
expr.setOp2(NullConstant.v());
} else if (op2 instanceof NullConstant && op1 instanceof NumericConstant) {
IntConstant nc = (IntConstant) op1;
if (nc.value != 0) {
throw new RuntimeException("expected value 0 for int constant. Got " + expr);
}
expr.setOp1(nullConstant);
}
} else {
throw new RuntimeException("error: do not handle if: " + u);
}
}
}
}
// For null_type locals: replace their use by NullConstant()
List uses = jBody.getUseBoxes();
// List defs = jBody.getDefBoxes();
List toNullConstantify = new ArrayList();
List toRemove = new ArrayList();
for (Local l : jBody.getLocals()) {
if (l.getType() instanceof NullType) {
toRemove.add(l);
for (ValueBox vb : uses) {
Value v = vb.getValue();
if (v == l) {
toNullConstantify.add(vb);
}
}
}
}
for (ValueBox vb : toNullConstantify) {
System.out.println("replace valuebox '" + vb + " with null constant");
vb.setValue(nullConstant);
}
for (Local l : toRemove) {
System.out.println("removing null_type local " + l);
l.setType(objectType);
}
}
// We pack locals that are not used in overlapping regions. This may
// again lead to unused locals which we have to remove.
LocalPacker.v().transform(jBody);
UnusedLocalEliminator.v().transform(jBody);
PackManager.v().getTransform("jb.lns").apply(jBody);
// Some apps reference static fields as instance fields. We fix this
// on the fly.
if (Options.v().wrong_staticness() == Options.wrong_staticness_fix
|| Options.v().wrong_staticness() == Options.wrong_staticness_fixstrict) {
FieldStaticnessCorrector.v().transform(jBody);
MethodStaticnessCorrector.v().transform(jBody);
}
// Inline PackManager.v().getPack("jb").apply(jBody);
// Keep only transformations that have not been done
// at this point.
TrapTightener.v().transform(jBody);
TrapMinimizer.v().transform(jBody);
// LocalSplitter.v().transform(jBody);
Aggregator.v().transform(jBody);
// UnusedLocalEliminator.v().transform(jBody);
// TypeAssigner.v().transform(jBody);
// LocalPacker.v().transform(jBody);
// LocalNameStandardizer.v().transform(jBody);
// Remove if (null == null) goto x else . We can only do this
// after we have run the constant propagation as we might not be able
// to statically decide the conditions earlier.
ConditionalBranchFolder.v().transform(jBody);
// Remove unnecessary typecasts
ConstantCastEliminator.v().transform(jBody);
IdentityCastEliminator.v().transform(jBody);
// Remove unnecessary logic operations
IdentityOperationEliminator.v().transform(jBody);
// We need to run this transformer since the conditional branch folder
// might have rendered some code unreachable (well, it was unreachable
// before as well, but we didn't know).
UnreachableCodeEliminator.v().transform(jBody);
// Not sure whether we need this even though we do it earlier on as
// the earlier pass does not have type information
// CopyPropagator.v().transform(jBody);
// we might have gotten new dead assignments and unused locals through
// copy propagation and unreachable code elimination, so we have to do
// this again
DeadAssignmentEliminator.v().transform(jBody);
UnusedLocalEliminator.v().transform(jBody);
NopEliminator.v().transform(jBody);
// Remove unnecessary chains of return statements
DexReturnPacker.v().transform(jBody);
for (Unit u : jBody.getUnits()) {
if (u instanceof AssignStmt) {
AssignStmt ass = (AssignStmt) u;
if (ass.getRightOp() instanceof CastExpr) {
CastExpr c = (CastExpr) ass.getRightOp();
if (c.getType() instanceof NullType) {
ass.setRightOp(nullConstant);
}
}
}
if (u instanceof DefinitionStmt) {
DefinitionStmt def = (DefinitionStmt) u;
// If the body references a phantom class in a
// CaughtExceptionRef,
// we must manually fix the hierarchy
if (def.getLeftOp() instanceof Local && def.getRightOp() instanceof CaughtExceptionRef) {
Type t = def.getLeftOp().getType();
if (t instanceof RefType) {
RefType rt = (RefType) t;
if (rt.getSootClass().isPhantom() && !rt.getSootClass().hasSuperclass()
&& !rt.getSootClass().getName().equals("java.lang.Throwable")) {
rt.getSootClass().setSuperclass(Scene.v().getSootClass("java.lang.Throwable"));
}
}
}
}
}
// Replace local type null_type by java.lang.Object.
//
// The typing engine cannot find correct type for such code:
//
// null_type $n0;
// $n0 = null;
// $r4 = virtualinvoke $n0.();
//
for (Local l : jBody.getLocals()) {
Type t = l.getType();
if (t instanceof NullType) {
l.setType(objectType);
}
}
//Must be last to ensure local ordering does not change
PackManager.v().getTransform("jb.lns").apply(jBody);
// t_whole_jimplification.end();
return jBody;
}
/**
* Fixes the line numbers. If there is a unit without a line number, it gets the line number of the last (transitive)
* predecessor that has a line number.
*/
protected void fixLineNumbers() {
int prevLn = -1;
for (DexlibAbstractInstruction instruction : instructions) {
Unit unit = instruction.getUnit();
int lineNumber = unit.getJavaSourceStartLineNumber();
if (lineNumber < 0) {
if (prevLn >= 0) {
unit.addTag(new LineNumberTag(prevLn));
unit.addTag(new SourceLineNumberTag(prevLn));
}
} else {
prevLn = lineNumber;
}
}
}
private LocalSplitter localSplitter = null;
protected LocalSplitter getLocalSplitter() {
if (this.localSplitter == null) {
this.localSplitter = new LocalSplitter(DalvikThrowAnalysis.v());
}
return this.localSplitter;
}
private UnreachableCodeEliminator unreachableCodeEliminator = null;
protected UnreachableCodeEliminator getUnreachableCodeEliminator() {
if (this.unreachableCodeEliminator == null) {
this.unreachableCodeEliminator = new UnreachableCodeEliminator(DalvikThrowAnalysis.v());
}
return this.unreachableCodeEliminator;
}
private CopyPropagator copyPropagator = null;
protected CopyPropagator getCopyPopagator() {
if (this.copyPropagator == null) {
this.copyPropagator = new CopyPropagator(DalvikThrowAnalysis.v(), false);
}
return this.copyPropagator;
}
/**
* Set a dangling instruction for this body.
*
*/
public void setDanglingInstruction(DanglingInstruction i) {
dangling = i;
}
/**
* Return the instructions that appear (lexically) after the given instruction.
*
* @param instruction
* the instruction which successors will be returned.
*/
public List instructionsAfter(DexlibAbstractInstruction instruction) {
int i = instructions.indexOf(instruction);
if (i == -1) {
throw new IllegalArgumentException("Instruction" + instruction + "not part of this body.");
}
return instructions.subList(i + 1, instructions.size());
}
/**
* Return the instructions that appear (lexically) before the given instruction.
*
* The instruction immediately before the given is the first instruction and so on.
*
* @param instruction
* the instruction which successors will be returned.
*/
public List instructionsBefore(DexlibAbstractInstruction instruction) {
int i = instructions.indexOf(instruction);
if (i == -1) {
throw new IllegalArgumentException("Instruction " + instruction + " not part of this body.");
}
List l = new ArrayList();
l.addAll(instructions.subList(0, i));
Collections.reverse(l);
return l;
}
/**
* Add the traps of this body.
*
* Should only be called at the end jimplify.
*/
private void addTraps() {
final Jimple jimple = Jimple.v();
for (TryBlock tryItem : tries) {
int startAddress = tryItem.getStartCodeAddress();
int length = tryItem.getCodeUnitCount();// .getTryLength();
int endAddress = startAddress + length;// - 1;
Unit beginStmt = instructionAtAddress(startAddress).getUnit();
// (startAddress + length) typically points to the first byte of the
// first instruction after the try block
// except if there is no instruction after the try block in which
// case it points to the last byte of the last
// instruction of the try block. Removing 1 from (startAddress +
// length) always points to "somewhere" in
// the last instruction of the try block since the smallest
// instruction is on two bytes (nop = 0x0000).
Unit endStmt = instructionAtAddress(endAddress).getUnit();
// if the try block ends on the last instruction of the body, add a
// nop instruction so Soot can include
// the last instruction in the try block.
if (jBody.getUnits().getLast() == endStmt && instructionAtAddress(endAddress - 1).getUnit() == endStmt) {
Unit nop = jimple.newNopStmt();
jBody.getUnits().insertAfter(nop, endStmt);
endStmt = nop;
}
List hList = tryItem.getExceptionHandlers();
for (ExceptionHandler handler : hList) {
String exceptionType = handler.getExceptionType();
if (exceptionType == null) {
exceptionType = "Ljava/lang/Throwable;";
}
Type t = DexType.toSoot(exceptionType);
// exceptions can only be of RefType
if (t instanceof RefType) {
SootClass exception = ((RefType) t).getSootClass();
DexlibAbstractInstruction instruction = instructionAtAddress(handler.getHandlerCodeAddress());
if (!(instruction instanceof MoveExceptionInstruction)) {
logger.debug("" + String.format("First instruction of trap handler unit not MoveException but %s",
instruction.getClass().getName()));
} else {
((MoveExceptionInstruction) instruction).setRealType(this, exception.getType());
}
Trap trap = jimple.newTrap(exception, beginStmt, endStmt, instruction.getUnit());
jBody.getTraps().add(trap);
}
}
}
}
}
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