Class DexSSABuilder

java.lang.Object

com.ibm.wala.dalvik.ssa.AbstractIntRegisterMachine

com.ibm.wala.dalvik.ssa.DexSSABuilder

All Implemented Interfaces:

FixedPointConstants

public class DexSSABuilder
extends AbstractIntRegisterMachine

This class constructs an SSA IR from a backing ShrikeBT instruction stream.

The basic algorithm here is an abstract interpretation over the Java bytecode to determine types of stack locations and local variables. As a side effect, the flow functions of the abstract interpretation emit instructions, eliminating the stack abstraction and moving to a register-transfer language in SSA form.

Nested Class Summary

Nested classes/interfaces inherited from class AbstractIntRegisterMachine

AbstractIntRegisterMachine.BasicRegisterFlowProvider, AbstractIntRegisterMachine.FlowProvider, AbstractIntRegisterMachine.MachineState, AbstractIntRegisterMachine.Meeter

Modifier and Type	Class	Description
protected static class	AbstractIntRegisterMachine.BasicRegisterFlowProvider	This gives some basic facilities for shoving things around on the stack.
static interface	AbstractIntRegisterMachine.FlowProvider	Interface which defines a flow function for a basic block
class	AbstractIntRegisterMachine.MachineState	Representation of the state of the JVM stack machine at some program point.
protected static interface	AbstractIntRegisterMachine.Meeter	A Meeter object provides the dataflow logic needed to meet the abstract machine state for a dataflow meet.

Field Summary

Fields inherited from class AbstractIntRegisterMachine

BOTTOM, IGNORE, maxLocals, OPTIMISTIC, TOP, UNANALYZED

Modifier and Type	Field	Description
static final int	BOTTOM
static final int	IGNORE
protected final int	maxLocals	the max number of locals in play
static final boolean	OPTIMISTIC	Should uninitialized variables be considered TOP (optimistic) or BOTTOM (pessimistic);
static final int	TOP
static final int	UNANALYZED

Fields inherited from interface FixedPointConstants

CHANGED, CHANGED_AND_FIXED, CHANGED_MASK, FIXED_MASK, NOT_CHANGED, NOT_CHANGED_AND_FIXED, SIDE_EFFECT_MASK

Modifier and Type	Field	Description
static final byte	CHANGED	A return value which indicates that a lhs has changed, and the statement might need to be evaluated again.
static final byte	CHANGED_AND_FIXED	A return value which indicates that lhs has changed, and the statement need not be evaluated again.
static final int	CHANGED_MASK	The bit-mask which defines the "CHANGED" flag
static final int	FIXED_MASK	The bit-mask which defines the "FIXED" flag
static final byte	NOT_CHANGED	A return value which indicates that lhs has not changed, and the statement might need to be evaluated again.
static final byte	NOT_CHANGED_AND_FIXED	A return value which indicates that lhs has not changed, and the statement need not be evaluated again.
static final int	SIDE_EFFECT_MASK	The bit-mask which defines the "SIDE EFFECT" flag

Method Summary

Modifier and Type	Method	Description
void	build()	Build the IR
ShrikeIndirectionData	getIndirectionData()
com.ibm.wala.dalvik.ssa.DexSSABuilder.SSA2LocalMap	getLocalMap()
protected void	initializeVariables()	Convenience method ...
static DexSSABuilder	make(DexIMethod method, SSACFG cfg, DexCFG scfg, SSAInstruction[] instructions, SymbolTable symbolTable, boolean buildLocalMap, SSAPiNodePolicy piNodePolicy)

Methods inherited from class AbstractIntRegisterMachine

allocateNewLocalsArray, getEntryState, getIn, init, solve

Modifier and Type	Method	Description
int[]	allocateNewLocalsArray()
AbstractIntRegisterMachine.MachineState	getEntryState()
AbstractIntRegisterMachine.MachineState	getIn(DexCFG.BasicBlock bb)
protected void	init(AbstractIntRegisterMachine.Meeter meeter, AbstractIntRegisterMachine.FlowProvider flow)
boolean	solve()

Methods inherited from class Object

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

Method Details

make

public static DexSSABuilder make(DexIMethod method,
 SSACFG cfg,
 DexCFG scfg,
 SSAInstruction[] instructions,
 SymbolTable symbolTable,
 boolean buildLocalMap,
 SSAPiNodePolicy piNodePolicy)
                          throws IllegalArgumentException

Throws:

IllegalArgumentException

initializeVariables

protected void initializeVariables()

Description copied from class: AbstractIntRegisterMachine

Convenience method ... a little ugly .. perhaps delete later.

Overrides:

initializeVariables in class AbstractIntRegisterMachine

build

public void build()

Build the IR

getLocalMap

public com.ibm.wala.dalvik.ssa.DexSSABuilder.SSA2LocalMap getLocalMap()

getIndirectionData

public ShrikeIndirectionData getIndirectionData()