org.apache.bcel.generic.PUTFIELD Java Examples

@Override
public void visitPUTFIELD(PUTFIELD obj) {
    if (doForwardSubstitution()) {
        XField xfield = Hierarchy.findXField(obj, getCPG());
        if (xfield != null) {
            storeInstanceField(xfield, obj, false);
            return;
        }

    }
    handleNormalInstruction(obj);
}
 

@Override
public void visitPUTFIELD(PUTFIELD obj) {
    if (getNumWordsConsumed(obj) != 2) {
        super.visitPUTFIELD(obj);
        return;
    }

    IsNullValue nullValueStored = null;
    try {
        nullValueStored = getFrame().getTopValue();
    } catch (DataflowAnalysisException e1) {
        AnalysisContext.logError("Oops", e1);
    }
    super.visitPUTFIELD(obj);
    XField field = XFactory.createXField(obj, cpg);
    if (nullValueStored != null && ValueNumberAnalysisFeatures.REDUNDANT_LOAD_ELIMINATION) {
        try {
            ValueNumberFrame vnaFrameBefore = vnaDataflow.getFactAtLocation(getLocation());
            ValueNumber refValue = vnaFrameBefore.getStackValue(1);
            AvailableLoad load = new AvailableLoad(refValue, field);
            ValueNumberFrame vnaFrameAfter = vnaDataflow.getFactAfterLocation(getLocation());
            ValueNumber[] newValueNumbersForField = vnaFrameAfter.getAvailableLoad(load);
            if (newValueNumbersForField != null && trackValueNumbers) {
                for (ValueNumber v : newValueNumbersForField) {
                    getFrame().setKnownValue(v, nullValueStored);
                }
            }
        } catch (DataflowAnalysisException e) {
            AnalysisContext.logError("Oops", e);
        }
    }
}
 

/**
 * Is the instruction a write of a field?
 *
 * @param ins
 *            the Instruction to check
 * @param cpg
 *            ConstantPoolGen of the method containing the instruction
 * @return the Field if instruction is a write of a field, null otherwise
 */
public static FieldAnnotation isWrite(Instruction ins, ConstantPoolGen cpg) {
    if (ins instanceof PUTFIELD || ins instanceof PUTSTATIC) {
        FieldInstruction fins = (FieldInstruction) ins;
        String className = fins.getClassName(cpg);
        return new FieldAnnotation(className, fins.getName(cpg), fins.getSignature(cpg), fins instanceof PUTSTATIC);
    } else {
        return null;
    }
}
 

/**
 * @param aInstruction
 * @param aPoolGen
 */
public PUTFIELDReference(
    PUTFIELD aInstruction,
    ConstantPoolGen aPoolGen)
{
    super(aInstruction, aPoolGen);
}
 

/**
 * @param aInstruction
 * @param aPoolGen
 */
public PUTFIELDReference(
    PUTFIELD aInstruction,
    ConstantPoolGen aPoolGen)
{
    super(aInstruction, aPoolGen);
}
 

@Override
public void visitPUTFIELD(PUTFIELD putfield) {
    handleFieldStore(putfield);
}
 

@Override
public void transferInstruction(InstructionHandle handle, BasicBlock basicBlock, UnconditionalValueDerefSet fact)
        throws DataflowAnalysisException {

    Instruction instruction = handle.getInstruction();
    if (fact.isTop()) {
        return;
    }
    Location location = new Location(handle, basicBlock);

    // If this is a call to an assertion method,
    // change the dataflow value to be TOP.
    // We don't want to report future derefs that would
    // be guaranteed only if the assertion methods
    // returns normally.
    // TODO: at some point, evaluate whether we should revisit this
    if (isAssertion(handle) // || handle.getInstruction() instanceof ATHROW
    ) {
        if (DEBUG) {
            System.out.println("MAKING BOTTOM0 AT: " + location);
        }
        fact.clear();
        return;
    }

    // Get value number frame
    ValueNumberFrame vnaFrame = vnaDataflow.getFactAtLocation(location);
    if (!vnaFrame.isValid()) {
        if (DEBUG) {
            System.out.println("MAKING TOP1 AT: " + location);
        }
        // Probably dead code.
        // Assume this location can't be reached.
        makeFactTop(fact);
        return;
    }
    if (isNullCheck(handle, methodGen.getConstantPool())) {
        handleNullCheck(location, vnaFrame, fact);
    }

    // Check for calls to a method that unconditionally dereferences
    // a parameter. Mark any such arguments as derefs.
    if (CHECK_CALLS && instruction instanceof InvokeInstruction) {
        checkUnconditionalDerefDatabase(location, vnaFrame, fact);
    }

    // If this is a method call instruction,
    // check to see if any of the parameters are @NonNull,
    // and treat them as dereferences.
    if (CHECK_ANNOTATIONS && instruction instanceof InvokeInstruction) {
        checkNonNullParams(location, vnaFrame, fact);
    }

    if (CHECK_ANNOTATIONS && instruction instanceof ARETURN) {
        XMethod thisMethod = XFactory.createXMethod(methodGen);
        checkNonNullReturnValue(thisMethod, location, vnaFrame, fact);
    }

    if (CHECK_ANNOTATIONS && (instruction instanceof PUTFIELD || instruction instanceof PUTSTATIC)) {
        checkNonNullPutField(location, vnaFrame, fact);
    }

    // Check to see if an instance value is dereferenced here
    checkInstance(location, vnaFrame, fact);

    /*
    if (false) {
        fact.cleanDerefSet(location, vnaFrame);
    }*/

    if (DEBUG && fact.isTop()) {
        System.out.println("MAKING TOP2 At: " + location);
    }

}
 

/**
 * Return whether or not the given instruction can throw exceptions.
 *
 * @param handle
 *            the instruction
 * @return true if the instruction can throw an exception, false otherwise
 * @throws CFGBuilderException
 */
private boolean isPEI(InstructionHandle handle) throws CFGBuilderException {
    Instruction ins = handle.getInstruction();

    if (!(ins instanceof ExceptionThrower)) {
        return false;
    }

    if (ins instanceof NEW) {
        return false;
    }
    // if (ins instanceof ATHROW) return false;
    if (ins instanceof GETSTATIC) {
        return false;
    }
    if (ins instanceof PUTSTATIC) {
        return false;
    }
    if (ins instanceof ReturnInstruction) {
        return false;
    }
    if (ins instanceof INSTANCEOF) {
        return false;
    }
    if (ins instanceof MONITOREXIT) {
        return false;
    }
    if (ins instanceof LDC) {
        return false;
    }
    if (ins instanceof GETFIELD && !methodGen.isStatic()) {
        // Assume that GETFIELD on this object is not PEI
        return !isSafeFieldSource(handle.getPrev());
    }
    if (ins instanceof PUTFIELD && !methodGen.isStatic()) {
        // Assume that PUTFIELD on this object is not PEI
        int depth = ins.consumeStack(cpg);
        for (InstructionHandle prev = handle.getPrev(); prev != null; prev = prev.getPrev()) {
            Instruction prevInst = prev.getInstruction();
            if (prevInst instanceof BranchInstruction) {
                if (prevInst instanceof GotoInstruction) {
                    // Currently we support only jumps to the PUTFIELD itself
                    // This will cover simple cases like this.a = flag ? foo : bar
                    if (((BranchInstruction) prevInst).getTarget() == handle) {
                        depth = ins.consumeStack(cpg);
                    } else {
                        return true;
                    }
                } else if (!(prevInst instanceof IfInstruction)) {
                    // As IF instructions may fall through then the stack depth remains unchanged
                    // Actually we should not go here for normal Java bytecode: switch or jsr should not appear in this context
                    return true;
                }
            }
            depth = depth - prevInst.produceStack(cpg) + prevInst.consumeStack(cpg);
            if (depth < 1) {
                throw new CFGBuilderException("Invalid stack at " + prev + " when checking " + handle);
            }
            if (depth == 1) {
                InstructionHandle prevPrev = prev.getPrev();
                if (prevPrev != null && prevPrev.getInstruction() instanceof BranchInstruction) {
                    continue;
                }
                return !isSafeFieldSource(prevPrev);
            }
        }
    }
    return true;
}
 

/** @see org.apache.bcel.generic.Visitor */
public void visitPUTFIELD(PUTFIELD aPUTFIELD)
{
    addFieldReference(
        new PUTFIELDReference(aPUTFIELD, mCurrentPoolGen));
}
 

byte[] counterAdaptClass(final InputStream is, final String name)
        throws Exception
{
    JavaClass jc = new ClassParser(is, name + ".class").parse();
    ClassGen cg = new ClassGen(jc);
    ConstantPoolGen cp = cg.getConstantPool();
    if (!cg.isInterface()) {
        FieldGen fg = new FieldGen(ACC_PUBLIC,
                Type.getType("I"),
                "_counter",
                cp);
        cg.addField(fg.getField());
    }
    Method[] ms = cg.getMethods();
    for (int j = 0; j < ms.length; ++j) {
        MethodGen mg = new MethodGen(ms[j], cg.getClassName(), cp);
        if (!mg.getName().equals("<init>") && !mg.isStatic()
                && !mg.isAbstract() && !mg.isNative())
        {
            if (mg.getInstructionList() != null) {
                InstructionList il = new InstructionList();
                il.append(new ALOAD(0));
                il.append(new ALOAD(0));
                il.append(new GETFIELD(cp.addFieldref(name, "_counter", "I")));
                il.append(new ICONST(1));
                il.append(new IADD());
                il.append(new PUTFIELD(cp.addFieldref(name, "_counter", "I")));
                mg.getInstructionList().insert(il);
                mg.setMaxStack(Math.max(mg.getMaxStack(), 2));
                boolean lv = ms[j].getLocalVariableTable() == null;
                boolean ln = ms[j].getLineNumberTable() == null;
                if (lv) {
                    mg.removeLocalVariables();
                }
                if (ln) {
                    mg.removeLineNumbers();
                }
                cg.replaceMethod(ms[j], mg.getMethod());
            }
        }
    }
    return cg.getJavaClass().getBytes();
}
 

byte[] counterAdaptClass(final InputStream is, final String name)
        throws Exception
{
    JavaClass jc = new ClassParser(is, name + ".class").parse();
    ClassGen cg = new ClassGen(jc);
    ConstantPoolGen cp = cg.getConstantPool();
    if (!cg.isInterface()) {
        FieldGen fg = new FieldGen(ACC_PUBLIC,
                Type.getType("I"),
                "_counter",
                cp);
        cg.addField(fg.getField());
    }
    Method[] ms = cg.getMethods();
    for (int j = 0; j < ms.length; ++j) {
        MethodGen mg = new MethodGen(ms[j], cg.getClassName(), cp);
        if (!mg.getName().equals("<init>") && !mg.isStatic()
                && !mg.isAbstract() && !mg.isNative())
        {
            if (mg.getInstructionList() != null) {
                InstructionList il = new InstructionList();
                il.append(new ALOAD(0));
                il.append(new ALOAD(0));
                il.append(new GETFIELD(cp.addFieldref(name, "_counter", "I")));
                il.append(new ICONST(1));
                il.append(new IADD());
                il.append(new PUTFIELD(cp.addFieldref(name, "_counter", "I")));
                mg.getInstructionList().insert(il);
                mg.setMaxStack(Math.max(mg.getMaxStack(), 2));
                boolean lv = ms[j].getLocalVariableTable() == null;
                boolean ln = ms[j].getLineNumberTable() == null;
                if (lv) {
                    mg.removeLocalVariables();
                }
                if (ln) {
                    mg.removeLineNumbers();
                }
                cg.replaceMethod(ms[j], mg.getMethod());
            }
        }
    }
    return cg.getJavaClass().getBytes();
}
 

/** @see org.apache.bcel.generic.Visitor */
public void visitPUTFIELD(PUTFIELD aPUTFIELD)
{
    addFieldReference(
        new PUTFIELDReference(aPUTFIELD, mCurrentPoolGen));
}