Java Code Examples for proguard.classfile.instruction.Instruction#stackPushCount()

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Example 1
Source File: EscapingClassMarker.java    From proguard with GNU General Public License v2.0 5 votes vote down vote up 
public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction)
{
    // Does the instruction push a value that escapes?
    // We'll also count values that are returned, since they may be
    // downcast and the downcast type may escape in some calling
    // method.
    // TODO: Refine check: is a value is downcast to an escaping class, while it is being returned?
    if (instruction.stackPushCount(clazz) == 1 &&
        (referenceEscapeChecker.isInstanceEscaping(offset) ||
         referenceEscapeChecker.isInstanceReturned(offset)))
    {
        TracedStack stackAfter = partialEvaluator.getStackAfter(offset);
        Value       stackEntry = stackAfter.getTop(0);

        // Is it really a reference type?
        if (stackEntry.computationalType() == Value.TYPE_REFERENCE)
        {
            // Is it a plain class reference type?
            ReferenceValue referenceValue = stackEntry.referenceValue();
            if (referenceValue.isNull() != Value.ALWAYS &&
                !ClassUtil.isInternalArrayType(referenceValue.getType()))
            {
                // Do we know the class?
                Clazz referencedClass = referenceValue.getReferencedClass();
                if (referencedClass != null)
                {
                    if (DEBUG)
                    {
                        System.out.println("EscapingClassMarker: ["+clazz.getName()+"."+method.getName(clazz)+method.getDescriptor(clazz)+"]: "+instruction.toString(offset)+" pushes escaping ["+referencedClass.getName()+"]");
                    }

                    // Mark it, along with its superclasses.
                    referencedClass.hierarchyAccept(true, true, true, false, this);
                }
            }
        }
    }
}