soot.toDex

Class DexArrayInitDetector

java.lang.Object

soot.toDex.DexArrayInitDetector

public class DexArrayInitDetector
extends Object

Detector class that identifies array initializations and packs them into a single instruction: a = new char[2]; a[0] = 42; a[1] = 3; In dex, this can be expressed in a more concise way: a = new char[2]; fill(a, ...)

Author:

Steven Arzt

Constructor Summary

Constructors

Constructor and Description
DexArrayInitDetector()

Method Summary

Modifier and Type	Method and Description
void	constructArrayInitializations(Body body) Constructs packed array initializations from the individual element assignments in the given body
void	fixTraps(Body activeBody) Fixes the traps in the given body to account for assignments to individual array elements being replaced by a single fill instruction.
Set<Unit>	getIgnoreUnits()
List<Value>	getValuesForArrayInit(Unit arrayInit)
void	setMinimumArrayLength(int l) Sets the minimum array length to consider Only arrays with more than this number of elements will be identified, because we only need to handle those explicitly.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DexArrayInitDetector

public DexArrayInitDetector()

Method Detail

constructArrayInitializations

public void constructArrayInitializations(Body body)

Constructs packed array initializations from the individual element assignments in the given body

Parameters:

body - The body in which to look for element assignments

setMinimumArrayLength

public void setMinimumArrayLength(int l)

Sets the minimum array length to consider Only arrays with more than this number of elements will be identified, because we only need to handle those explicitly. For small arrays, we can have individual assignments for each element in the code, but for larger methods, this would exceed the allowed method size according to the JVM / Dalvik Spec.

Parameters:

l - the minimum length of arrays

getValuesForArrayInit

public List<Value> getValuesForArrayInit(Unit arrayInit)

getIgnoreUnits

public Set<Unit> getIgnoreUnits()

fixTraps

public void fixTraps(Body activeBody)

Fixes the traps in the given body to account for assignments to individual array elements being replaced by a single fill instruction. If a trap starts or ends in the middle of the replaced instructions, we have to move the trap.

Parameters:

activeBody - The body in which to fix the traps