Class Verifier

java.lang.Object

com.ibm.wala.shrike.shrikeBT.analysis.Analyzer

com.ibm.wala.shrike.shrikeBT.analysis.Verifier

public final class Verifier
extends Analyzer

This class typechecks intermediate code. It's very easy to use:

      MethodData md = ...;
      try {
          (new Verifier(md)).verify();
      } catch (Verifier.FailureException ex) {
          System.out.println("Verification failed at instruction "
              + ex.getOffset() + ": " + ex.getReason());
      }

 

For full verification you need to provide class hierarchy information using setClassHierarchy. Without this information, we can't compute the exact types of variables at control flow merge points. If you don't provide a hierarchy, or the hierarchy you provide is partial, then the Verifier will be optimistic.

This method can also be used to gather type information for every stack and local variable at every program point. Just call computeTypes() instead of verify() and then retrieve the results with getLocalTypes() and getStackTypes().

Nested Class Summary

Nested classes/interfaces inherited from class com.ibm.wala.shrike.shrikeBT.analysis.Analyzer

Analyzer.FailureException, Analyzer.PathElement, Analyzer.TypeVisitor

Field Summary

Fields inherited from class com.ibm.wala.shrike.shrikeBT.analysis.Analyzer

backEdges, basicBlockStarts, classType, handlers, hierarchy, instructions, instToBC, isConstructor, isStatic, locals, maxLocals, maxStack, noEdges, noStrings, signature, stacks, stackSizes, thisType, topType, varTypes

Constructor Summary

Constructors

Constructor	Description
Verifier(boolean isConstructor, boolean isStatic, String classType, String signature, IInstruction[] instructions, ExceptionHandler[][] handlers, int[] instToBC, String[][] vars)	Initialize a verifier.
Verifier(MethodData info)	Initialize a verifier.
Verifier(MethodData info, int[] instToBC, String[][] vars)

Method Summary

Modifier and Type	Method	Description
void	computeTypes()
void	verify()	Try to verify the method.
void	verifyCollectAll()

Methods inherited from class com.ibm.wala.shrike.shrikeBT.analysis.Analyzer

computeTypes, createAnalyzer, findCommonSupertype, getBackEdges, getBasicBlockStarts, getInstructions, getLocalTypes, getReachableFrom, getReachableFrom, getReachableFromUpdate, getReachingToUpdate, getStackSizes, getStackTypes, initTypeInfo, isSubtypeOf, setClassHierarchy, stripSharp

Methods inherited from class java.lang.Object

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

Constructor Details

Verifier

public Verifier(boolean isConstructor,
 boolean isStatic,
 String classType,
 String signature,
 IInstruction[] instructions,
 ExceptionHandler[][] handlers,
 int[] instToBC,
 String[][] vars)

Initialize a verifier.

Verifier

public Verifier(MethodData info)
         throws NullPointerException

Initialize a verifier.

Throws:

NullPointerException - if info is null

Verifier

public Verifier(MethodData info,
 int[] instToBC,
 String[][] vars)
         throws NullPointerException

Throws:

NullPointerException

Method Details

verify

public void verify()
            throws Analyzer.FailureException

Try to verify the method. If verification is unsuccessful, we throw an exception.

Throws:

Analyzer.FailureException - the method contains invalid bytecode

verifyCollectAll

public void verifyCollectAll()
                      throws Analyzer.FailureException

Throws:

Analyzer.FailureException

computeTypes

public void computeTypes()
                  throws Analyzer.FailureException

Throws:

Analyzer.FailureException