/**
* Gets the type of a local variable that is used to store a value of a given class. This method
* partitions all classes into one of the following categories:
*
* <p>
*
* <blockquote>
*
* <pre>
*
* Local Variable Type | Types
* ---------------------+-------
* INT | boolean, byte, short, int
* FLOAT | float
* LONG | long
* DOUBLE | double
* ADDRESS | Address
* UWORD | UWord
* OFFSET | Offset
* REFERENCE | types in java.lang.Object hierarchy
*
* </pre>
*
* </blockquote>
*
* <p>
*
* @param type the type of a value that will be stored in a local variable
* @return the local variable type for storing values of type <code>type</code>
*/
public static Klass getLocalTypeFor(Klass type) {
switch (type.getSystemID()) {
case CID.BOOLEAN:
case CID.BYTE:
case CID.SHORT:
case CID.CHAR:
case CID.INT:
{
return Klass.INT;
}
case CID.FLOAT:
case CID.LONG:
case CID.DOUBLE:
{
return type;
}
case CID.UWORD:
case CID.OFFSET:
case CID.ADDRESS:
{
return type;
}
default:
{
Assert.that(Klass.REFERENCE.isAssignableFrom(type));
return Klass.REFERENCE;
}
}
}
/**
* Get a <code>Local</code> instance to represent a value of a given type that will be
* stored/loaded to/from a given local variable.
*
* @param type the type of the value
* @param index the index of the local variable
* @param isParameter true if the local is a parameter
* @return the variable at index <code>index</code> in which values of type <code>type</code> are
* stored
*/
private Local allocateLocalPrim(Klass type, int index, boolean isParameter) {
Assert.that(localTypes.length < 0xFFFF);
Assert.that(
index >= 0 && index < localTypes.length,
"index=" + index + " localTypes.length=" + localTypes.length);
Klass localType = getLocalTypeFor(type);
int key = localType.getSuiteID();
/* We need a hard partition between uses of a slot as a reference vs. an Address, Offset, or UWord.
* The partitioning of java primitives and objects is accomplished not only by the type passed in here, but
* by the bytecode verifier. We can't be sure that some bytecodes are refering to the same local variable
* as both a reference and as a Squawk primitive. Without that kind of support we are conservative here
* and force a clash whenever javac uses the same local index for a reference and a Squawk primitive.
*/
if (localType.isSquawkPrimitive()) {
key = Klass.REFERENCE.getSuiteID();
}
key = key << 16 | index;
if (localValues == null) {
localValues = new IntHashtable();
}
Local local = (Local) localValues.get(key);
if (local == null) {
local = new Local(localType, index, isParameter);
localValues.put(key, local);
}
/*
* Ensure that the original class file does not use the same local variable
* for both a Squawk primitive value and any other reference value. This prevents the
* translator from having to do a complete liveness analysis to de-multiplex
* such a local variable slot. Such de-multiplexing is required as Squawk primitives
* are 'magically' translated into integers (or longs on a 64 bit system).
*/
if (localType.isSquawkPrimitive() || local.getType().isSquawkPrimitive()) {
if (localType != local.getType()) {
throw codeParser.verifyError(
getBadAddressLocalVariableMessage(index, localType, local.getType()));
}
}
// System.out.println("allocated: "+local+" index "+index);
/// *if[SCOPEDLOCALVARIABLES]*/
codeParser.localVariableAllocated(codeParser.getCurrentIP(), local);
/// *end[SCOPEDLOCALVARIABLES]*/
return local;
}
