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package jdk.nashorn.internal.codegen;
import static jdk.nashorn.internal.codegen.CompilerConstants.ARGUMENTS;
import static jdk.nashorn.internal.codegen.CompilerConstants.constructorNoLookup;
import static jdk.nashorn.internal.codegen.CompilerConstants.typeDescriptor;
import static jdk.nashorn.internal.codegen.ObjectClassGenerator.PRIMITIVE_FIELD_TYPE;
import static jdk.nashorn.internal.codegen.ObjectClassGenerator.getFieldName;
import static jdk.nashorn.internal.codegen.ObjectClassGenerator.getPaddedFieldCount;
import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.getArrayIndex;
import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;
import java.util.List;
import jdk.nashorn.internal.codegen.types.Type;
import jdk.nashorn.internal.ir.Symbol;
import jdk.nashorn.internal.runtime.Context;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.PropertyMap;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.arrays.ArrayIndex;
/**
* Analyze an object's characteristics for appropriate code generation. This
* is used for functions and for objects. A field object take a set of values which
* to assign to the various fields in the object. This is done by the generated code
*
* @param <T> the value type for the fields being written on object creation, e.g. Node
* @see jdk.nashorn.internal.ir.Node
*/
public abstract class FieldObjectCreator<T> extends ObjectCreator<T> {
private String fieldObjectClassName;
private Class<? extends ScriptObject> fieldObjectClass;
private int fieldCount;
private int paddedFieldCount;
private int paramCount;
/** call site flags to be used for invocations */
private final int callSiteFlags;
/** are we creating this field object from 'eval' code? */
private final boolean evalCode;
/**
* Constructor
*
* @param codegen code generator
* @param tuples tuples for fields in object
*/
FieldObjectCreator(final CodeGenerator codegen, final List<MapTuple<T>> tuples) {
this(codegen, tuples, false, false);
}
/**
* Constructor
*
* @param codegen code generator
* @param tuples tuples for fields in object
* @param isScope is this a scope object
* @param hasArguments does the created object have an "arguments" property
*/
FieldObjectCreator(final CodeGenerator codegen, final List<MapTuple<T>> tuples, final boolean isScope, final boolean hasArguments) {
super(codegen, tuples, isScope, hasArguments);
this.callSiteFlags = codegen.getCallSiteFlags();
this.evalCode = codegen.isEvalCode();
countFields();
findClass();
}
@Override
public void createObject(final MethodEmitter method) {
makeMap();
final String className = getClassName();
// NOTE: we must load the actual structure class here, because the API operates with Nashorn Type objects,
// and Type objects need a loaded class, for better or worse. We also have to be specific and use the type
// of the actual structure class, we can't generalize it to e.g. Type.typeFor(ScriptObject.class) as the
// exact type information is needed for generating continuations in rest-of methods. If we didn't do this,
// object initializers like { x: arr[i] } would fail during deoptimizing compilation on arr[i], as the
// values restored from the RewriteException would be cast to "ScriptObject" instead of to e.g. "JO4", and
// subsequently the "PUTFIELD J04.L0" instruction in the continuation code would fail bytecode verification.
assert fieldObjectClass != null;
method._new(fieldObjectClass).dup();
loadMap(method); //load the map
if (isScope()) {
loadScope(method);
if (hasArguments()) {
method.loadCompilerConstant(ARGUMENTS);
method.invoke(constructorNoLookup(className, PropertyMap.class, ScriptObject.class, ARGUMENTS.type()));
} else {
method.invoke(constructorNoLookup(className, PropertyMap.class, ScriptObject.class));
}
} else {
method.invoke(constructorNoLookup(className, PropertyMap.class));
}
}
/**
* Create a scope for a for-in/of loop as defined in ES6 13.7.5.13 step 5.g.iii
*
* @param method the method emitter
*/
void createForInIterationScope(final MethodEmitter method) {
assert fieldObjectClass != null;
assert isScope();
assert getMap() != null;
final String className = getClassName();
method._new(fieldObjectClass).dup();
loadMap(method); //load the map
loadScope(method);
// We create a scope identical to the currently active one, so use its parent as our parent
method.invoke(ScriptObject.GET_PROTO);
method.invoke(constructorNoLookup(className, PropertyMap.class, ScriptObject.class));
}
@Override
public void populateRange(final MethodEmitter method, final Type objectType, final int objectSlot, final int start, final int end) {
method.load(objectType, objectSlot);
// Set values.
for (int i = start; i < end; i++) {
final MapTuple<T> tuple = tuples.get(i);
//we only load when we have both symbols and values (which can be == the symbol)
//if we didn't load, we need an array property
if (tuple.symbol != null && tuple.value != null) {
final int index = getArrayIndex(tuple.key);
method.dup();
if (!isValidArrayIndex(index)) {
putField(method, tuple.key, tuple.symbol.getFieldIndex(), tuple);
} else {
putSlot(method, ArrayIndex.toLongIndex(index), tuple);
}
//this is a nop of tuple.key isn't e.g. "apply" or another special name
method.invalidateSpecialName(tuple.key);
}
}
}
@Override
protected PropertyMap makeMap() {
assert propertyMap == null : "property map already initialized";
propertyMap = newMapCreator(fieldObjectClass).makeFieldMap(hasArguments(), codegen.useDualFields(), fieldCount, paddedFieldCount, evalCode);
return propertyMap;
}
/**
* Store a value in a field of the generated class object.
*
* @param method Script method.
* @param key Property key.
* @param fieldIndex Field number.
* @param tuple Tuple to store.
*/
private void putField(final MethodEmitter method, final String key, final int fieldIndex, final MapTuple<T> tuple) {
final Type fieldType = codegen.useDualFields() && tuple.isPrimitive() ? PRIMITIVE_FIELD_TYPE : Type.OBJECT;
final String fieldClass = getClassName();
final String fieldName = getFieldName(fieldIndex, fieldType);
final String fieldDesc = typeDescriptor(fieldType.getTypeClass());
assert fieldName.equals(getFieldName(fieldIndex, PRIMITIVE_FIELD_TYPE)) || fieldType.isObject() : key + " object keys must store to L*-fields";
assert fieldName.equals(getFieldName(fieldIndex, Type.OBJECT)) || fieldType.isPrimitive() : key + " primitive keys must store to J*-fields";
loadTuple(method, tuple, true);
method.putField(fieldClass, fieldName, fieldDesc);
}
/**
* Store a value in an indexed slot of a generated class object.
*
* @param method Script method.
* @param index Slot index.
* @param tuple Tuple to store.
*/
private void putSlot(final MethodEmitter method, final long index, final MapTuple<T> tuple) {
loadIndex(method, index);
loadTuple(method, tuple, false); //we don't pack array like objects
method.dynamicSetIndex(callSiteFlags);
}
/**
* Locate (or indirectly create) the object container class.
*/
private void findClass() {
fieldObjectClassName = isScope() ?
ObjectClassGenerator.getClassName(fieldCount, paramCount, codegen.useDualFields()) :
ObjectClassGenerator.getClassName(paddedFieldCount, codegen.useDualFields());
try {
this.fieldObjectClass = Context.forStructureClass(Compiler.binaryName(fieldObjectClassName));
} catch (final ClassNotFoundException e) {
throw new AssertionError("Nashorn has encountered an internal error. Structure can not be created.");
}
}
@Override
protected Class<? extends ScriptObject> getAllocatorClass() {
return fieldObjectClass;
}
/**
* Get the class name for the object class,
* e.g. {@code com.nashorn.oracle.scripts.JO2P0}
*
* @return script class name
*/
String getClassName() {
return fieldObjectClassName;
}
/**
* Tally the number of fields and parameters.
*/
private void countFields() {
for (final MapTuple<T> tuple : tuples) {
final Symbol symbol = tuple.symbol;
if (symbol != null) {
if (hasArguments() && symbol.isParam()) {
symbol.setFieldIndex(paramCount++);
} else if (!isValidArrayIndex(getArrayIndex(tuple.key))) {
symbol.setFieldIndex(fieldCount++);
}
}
}
paddedFieldCount = getPaddedFieldCount(fieldCount);
}
}