com.tangosol.dev.assembler.MethodParametersAttribute Maven / Gradle / Ivy
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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.dev.assembler;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
/**
* Represents a Java Virtual Machine "MethodParameters" attribute which contains
* information of the various parameters of a method. This attribute can only
* reside on method_info.
*
* The MethodParameters Attribute is defined by the JDK 1.8 documentation as:
*
*
* MethodParameters_attribute
* {
* u2 attribute_name_index;
* u4 attribute_length;
* u1 parameters_count;
* {
* u2 name_index;
* u2 access_flags;
* } parameters[parameters_count];
* }
*
* Note: this method should be called prior to {@link #addParameter(int, String, int)}
*
* @param cParam the number of parameters within a method definition
*/
public void setParameterCount(int cParam)
{
ensureMethodParams(cParam);
}
// ----- helpers --------------------------------------------------------
/**
* Return a {@link MethodParameter} array to hold method parameter
* descriptions.
*
* @param cParam the maximum number of parameters
*
* @return a MethodParameter array to hold method parameter descriptions
*/
protected MethodParameter[] ensureMethodParams(int cParam)
{
MethodParameter[] aParam = m_aParam;
if (aParam == null)
{
aParam = m_aParam = new MethodParameter[cParam];
}
return aParam;
}
// ----- inner class: MethodParameter -----------------------------------
/**
* MethodParameter holds description information for each parameter including
* the parameter's name and access flags.
*/
protected class MethodParameter
extends VMStructure
implements Constants
{
// ----- constructors -----------------------------------------------
/**
* Construct a MethodParameter that refers to the ith
* parameter, where {@code i == iParam}.
*
* @param iParam the index of the parameter in the method descriptor
*/
protected MethodParameter(int iParam)
{
m_iParam = iParam;
}
// ----- VMStructure operations -------------------------------------
@Override
protected void disassemble(DataInput stream, ConstantPool pool) throws IOException
{
int iName = stream.readUnsignedShort();
if (iName > 0)
{
m_name = (UtfConstant) pool.getConstant(iName);
}
m_nFlags = stream.readUnsignedShort();
}
@Override
protected void preassemble(ConstantPool pool)
{
if (m_name != null)
{
pool.registerConstant(m_name);
}
}
@Override
protected void assemble(DataOutput stream, ConstantPool pool) throws IOException
{
stream.writeShort(pool.findConstant(m_name));
stream.writeShort(m_nFlags);
}
// ----- parameter name ---------------------------------------------
/**
* Return the name of the parameter.
*
* @return the name of the parameter
*/
public String getParameterName()
{
return m_name.getValue();
}
/**
* Set the name of the parameter.
*
* @param sName the name of the parameter
*/
public void setParameterName(String sName)
{
m_name = new UtfConstant(sName);
}
// ----- access flags methods ---------------------------------------
/**
* Return whether the parameter is marked as final.
*
* @return whether the parameter is marked as final
*/
public boolean isFinal()
{
return (m_nFlags & ACC_FINAL) == ACC_FINAL;
}
/**
* Set whether the parameter is marked as final.
*
* @param fFinal whether the parameter is marked as final
*/
public void setFinal(boolean fFinal)
{
m_nFlags = fFinal ? m_nFlags | ACC_FINAL
: m_nFlags & ~ACC_FINAL;
}
/**
* Return whether the parameter is marked as synthetic.
*
* @return whether the parameter is marked as synthetic
*/
public boolean isSynthetic()
{
return (m_nFlags & ACC_SYNTHETIC) == ACC_SYNTHETIC;
}
/**
* Set whether the parameter is marked as synthetic.
*
* @param fSynthetic whether the parameter is marked as synthetic
*/
public void setSynthetic(boolean fSynthetic)
{
m_nFlags = fSynthetic ? m_nFlags | ACC_SYNTHETIC
: m_nFlags & ~ACC_SYNTHETIC;
}
/**
* Return whether the parameter is marked as mandated.
*
* @return whether the parameter is marked as mandated
*/
public boolean isMandated()
{
return (m_nFlags & ACC_MANDATED) == ACC_MANDATED;
}
/**
* Set whether the parameter is marked as mandated.
*
* @param fMandated whether the parameter is marked as mandated
*/
public void setMandated(boolean fMandated)
{
m_nFlags = fMandated ? m_nFlags | ACC_MANDATED
: m_nFlags & ~ACC_MANDATED;
}
/**
* Set a bit mask representing the access flags for this parameter.
*
* @param nFlags a bit mask representing the access flags for this
* parameter
*/
public void setAccessFlags(int nFlags)
{
if ((nFlags & ~(ACC_FINAL | ACC_SYNTHETIC | ACC_MANDATED)) != 0)
{
throw new IllegalArgumentException("Invalid access flag set; " +
"only final, synthetic or mandated are permitted");
}
m_nFlags = nFlags;
}
/**
* Return the type for the parameter using internal type signatures.
*
* @return the type for the parameter using internal type signatures
*/
public String getType()
{
Method method = (Method) MethodParametersAttribute.this.getContext();
return method.getTypes()[m_iParam + 1];
}
// ----- constants --------------------------------------------------
/**
* Final parameter.
*/
public static final int ACC_FINAL = 0x0010;
/**
* Synthetic parameter.
*/
public static final int ACC_SYNTHETIC = 0x1000;
/**
* Mandated parameter.
*/
public static final int ACC_MANDATED = 0x8000;
// ----- data members -----------------------------------------------
/**
* The name of the parameter.
*/
protected UtfConstant m_name;
/**
* The access flags of the parameter.
*/
protected int m_nFlags;
/**
* The index of the parameter in the method descriptor.
*/
protected int m_iParam;
}
// ----- data members ---------------------------------------------------
/**
* An array of MethodParameters with each element describing the
* ith parameter as defined in the associated
* MethodDescriptor structure.
*/
protected MethodParameter[] m_aParam;
}