Package com.pnfsoftware.jeb.core.units.code.asm.cfg

Class CFGVerifier<InsnType extends IInstruction>

java.lang.Object

com.pnfsoftware.jeb.core.units.code.asm.cfg.CFGVerifier<InsnType>

Type Parameters:

InsnType -

public class CFGVerifier<InsnType extends IInstruction>
extends Object

Verifier of control flow graphs. Verification is expensive: this class should be reserved for test cases or debug-mode.

Field Summary

Fields

Modifier and Type	Field	Description
protected CFG<InsnType>	cfg

Constructor Summary

Constructors

Constructor	Description
CFGVerifier(CFG<InsnType> cfg)

Method Summary

Modifier and Type	Method	Description
protected void	customVerification()	Custom validation method that may be overridden by subclasses which wish to validate the CFG further.
protected boolean	shouldExpectFallthrough(InsnType insn)
void	verify()	A CFG is considered valid if:

Methods inherited from class java.lang.Object

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

Field Details

cfg

protected CFG<InsnType extends IInstruction> cfg

Constructor Details

CFGVerifier

public CFGVerifier(CFG<InsnType> cfg)

Method Details

customVerification

protected void customVerification()
                           throws CfgVerificationException

Custom validation method that may be overridden by subclasses which wish to validate the CFG further. This method is called by verify() as a first validation step. The default implementation does nothing (return true).

Throws:

CfgVerificationException - thrown if the CFG is deemed invalid

shouldExpectFallthrough

protected boolean shouldExpectFallthrough(InsnType insn)

Parameters:

insn -

Returns:

verify

public void verify()
            throws CfgVerificationException

A CFG is considered valid if:

• there is only one (or none) branching instruction per basic block, located at its end (taking into account the possible delay-slot)
• the branching instructions are synchronized with the edges, i.e. they both represent the same information in the same order (fallthrough first)
• there is no duplicate edges

Note: duplicate edges can happen at native level due to JCC-to-fallthrough.

Throws:

CfgVerificationException - thrown if the CFG verification failed