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package jdk.nashorn.internal.codegen;

import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.getArrayIndex;
import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;

import java.util.ArrayList;
import java.util.List;
import jdk.nashorn.internal.ir.Symbol;
import jdk.nashorn.internal.runtime.AccessorProperty;
import jdk.nashorn.internal.runtime.Property;
import jdk.nashorn.internal.runtime.PropertyMap;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.SpillProperty;

Class that creates PropertyMap sent to script object constructors.
Type parameters:
  • <T> – value type for tuples, e.g. Symbol
/** * Class that creates PropertyMap sent to script object constructors. * @param <T> value type for tuples, e.g. Symbol */
public class MapCreator<T> {
Object structure for objects associated with this map
/** Object structure for objects associated with this map */
private final Class<?> structure;
key set for object map
/** key set for object map */
private final List<MapTuple<T>> tuples;
Constructor
Params:
  • structure – structure to generate map for (a JO subclass)
  • tuples – list of tuples for map
/** * Constructor * * @param structure structure to generate map for (a JO subclass) * @param tuples list of tuples for map */
MapCreator(final Class<? extends ScriptObject> structure, final List<MapTuple<T>> tuples) { this.structure = structure; this.tuples = tuples; }
Constructs a property map based on a set of fields.
Params:
  • hasArguments – does the created object have an "arguments" property
  • fieldCount – Number of fields in use.
  • fieldMaximum – Number of fields available.
  • evalCode – is this property map created for 'eval' code?
Returns:New map populated with accessor properties.
/** * Constructs a property map based on a set of fields. * * @param hasArguments does the created object have an "arguments" property * @param fieldCount Number of fields in use. * @param fieldMaximum Number of fields available. * @param evalCode is this property map created for 'eval' code? * @return New map populated with accessor properties. */
PropertyMap makeFieldMap(final boolean hasArguments, final boolean dualFields, final int fieldCount, final int fieldMaximum, final boolean evalCode) { final List<Property> properties = new ArrayList<>(); assert tuples != null; for (final MapTuple<T> tuple : tuples) { final String key = tuple.key; final Symbol symbol = tuple.symbol; final Class<?> initialType = dualFields ? tuple.getValueType() : Object.class; if (symbol != null && !isValidArrayIndex(getArrayIndex(key))) { final int flags = getPropertyFlags(symbol, hasArguments, evalCode, dualFields); final Property property = new AccessorProperty( key, flags, structure, symbol.getFieldIndex(), initialType); properties.add(property); } } return PropertyMap.newMap(properties, structure.getName(), fieldCount, fieldMaximum, 0); } PropertyMap makeSpillMap(final boolean hasArguments, final boolean dualFields) { final List<Property> properties = new ArrayList<>(); int spillIndex = 0; assert tuples != null; for (final MapTuple<T> tuple : tuples) { final String key = tuple.key; final Symbol symbol = tuple.symbol; final Class<?> initialType = dualFields ? tuple.getValueType() : Object.class; if (symbol != null && !isValidArrayIndex(getArrayIndex(key))) { final int flags = getPropertyFlags(symbol, hasArguments, false, dualFields); properties.add( new SpillProperty( key, flags, spillIndex++, initialType)); } } return PropertyMap.newMap(properties, structure.getName(), 0, 0, spillIndex); }
Compute property flags given local state of a field. May be overridden and extended,
Params:
  • symbol – symbol to check
  • hasArguments – does the created object have an "arguments" property
Returns:flags to use for fields
/** * Compute property flags given local state of a field. May be overridden and extended, * * @param symbol symbol to check * @param hasArguments does the created object have an "arguments" property * * @return flags to use for fields */
static int getPropertyFlags(final Symbol symbol, final boolean hasArguments, final boolean evalCode, final boolean dualFields) { int flags = 0; if (symbol.isParam()) { flags |= Property.IS_PARAMETER; } if (hasArguments) { flags |= Property.HAS_ARGUMENTS; } // See ECMA 5.1 10.5 Declaration Binding Instantiation. // Step 2 If code is eval code, then let configurableBindings // be true else let configurableBindings be false. // We have to make vars, functions declared in 'eval' code // configurable. But vars, functions from any other code is // not configurable. if (symbol.isScope() && !evalCode) { flags |= Property.NOT_CONFIGURABLE; } if (symbol.isFunctionDeclaration()) { flags |= Property.IS_FUNCTION_DECLARATION; } if (symbol.isConst()) { flags |= Property.NOT_WRITABLE; } if (symbol.isBlockScoped()) { flags |= Property.IS_LEXICAL_BINDING; } // Mark symbol as needing declaration. Access before declaration will throw a ReferenceError. if (symbol.isBlockScoped() && symbol.isScope()) { flags |= Property.NEEDS_DECLARATION; } if (dualFields) { flags |= Property.DUAL_FIELDS; } return flags; } }