/**
* Constructor.
*
* @param code The {@link Code} attribute being decompiled.
*/
public Frame(Code code) {
operandStack = new Stack<String>();
localVars = new LocalVarInfo[code.getMaxLocals()];
int i = 0;
MethodInfo mi = code.getMethodInfo();
// Instance methods have an implicit first parameter of "this".
if (!mi.isStatic()) {
localVars[i++] = new LocalVarInfo("this", true);
}
// Name the passed-in local vars by their types. longs and doubles
// take up two slots.
String[] paramTypes = mi.getParameterTypes();
for (int param_i = 0; param_i < paramTypes.length; param_i++) {
String type = paramTypes[param_i];
if (type.indexOf('.') > -1) { // Class types.
type = type.substring(type.lastIndexOf('.') + 1);
}
String name = "localVar_" + type + "_" + param_i;
localVars[i] = new LocalVarInfo(name, true);
i++;
if ("long".equals(type) || "double".equals(type)) {
i++; // longs and doubles take up two slots.
}
}
// NOTE: Other local vars will still be "null" here! We need to
// infer their types from their usage during disassembly/decompilation.
System.out.println("NOTE: " + (localVars.length - i) + " unknown localVars slots");
}
/**
* If debugging was enabled during compilation, this method returns the name of the given
* parameter to this method. Otherwise, <code>null</code> is returned.
*
* @param index The index of the parameter.
* @return The name of the parameter, or <code>null</code>.
*/
public String getParameterName(int index) {
if (index >= 0 && index < getParameterCount()) {
if (codeAttr != null) {
return codeAttr.getParameterName(index);
}
}
return null;
}
/**
* Reads an attribute for this method from the specified input stream.
*
* @param in The input stream to read from.
* @return The attribute read, possibly <code>null</code> if it was known to be unimportant for
* our purposes.
* @throws IOException If an IO error occurs.
*/
private AttributeInfo readAttribute(DataInputStream in) throws IOException {
AttributeInfo ai = null;
int attributeNameIndex = in.readUnsignedShort();
int attributeLength = in.readInt();
String attrName = cf.getUtf8ValueFromConstantPool(attributeNameIndex);
if (CODE.equals(attrName)) { // 4.7.3
ai = Code.read(this, in);
} else if (EXCEPTIONS.equals(attrName)) { // 4.7.4
int exceptionCount = in.readUnsignedShort();
int[] exceptionIndexTable = null;
if (exceptionCount > 0) {
exceptionIndexTable = new int[exceptionCount];
for (int i = 0; i < exceptionCount; i++) {
exceptionIndexTable[i] = in.readUnsignedShort();
}
}
Exceptions e = new Exceptions(this, exceptionIndexTable);
ai = e;
}
// TODO: Handle other Attribute types.
// Attributes common to all members, or unhandled attributes.
else {
ai = super.readAttribute(in, attrName, attributeLength);
// if (ai!=null) { // "Deprecated" attribute returns null
// System.out.println("-------------- " + ai.getName());
// }
}
return ai;
}
