private static EnumMap<JavaKind, LocationIdentity> initArrayLocations() {
EnumMap<JavaKind, LocationIdentity> result = new EnumMap<>(JavaKind.class);
for (JavaKind kind : JavaKind.values()) {
result.put(kind, NamedLocationIdentity.mutable("Array: " + kind.getJavaName()));
}
return result;
}
@Fold
static LocationIdentity getArrayLocation(JavaKind kind) {
return NamedLocationIdentity.getArrayLocation(kind);
}
/** A {@link LocationIdentity} with a name. */
public class NamedLocationIdentity extends LocationIdentity implements FormatWithToString {
/** Map for asserting all {@link NamedLocationIdentity} instances have a unique name. */
static class DB {
private static final HashSet<String> map = new HashSet<>();
static boolean checkUnique(String name) {
if (!map.add(name)) {
throw new AssertionError("identity " + name + " already exists");
}
return true;
}
}
/** Denotes the location of a value that is guaranteed to be unchanging. */
public static final LocationIdentity FINAL_LOCATION =
NamedLocationIdentity.immutable("FINAL_LOCATION");
/** Denotes the location of the length field of a Java array. */
public static final LocationIdentity ARRAY_LENGTH_LOCATION =
NamedLocationIdentity.immutable("[].length");
public static LocationIdentity any() {
return ANY_LOCATION;
}
private final String name;
private final boolean immutable;
protected NamedLocationIdentity(String name, boolean immutable) {
this.name = name;
this.immutable = immutable;
assert DB.checkUnique(name);
}
/**
* Creates a named unique location identity for read and write operations against mutable memory.
*
* @param name the name of the new location identity
*/
public static NamedLocationIdentity mutable(String name) {
return create(name, false);
}
/**
* Creates a named unique location identity for read operations against immutable memory.
* Immutable memory will never have a visible write in the graph, which is more restictive than
* Java final.
*
* @param name the name of the new location identity
*/
public static NamedLocationIdentity immutable(String name) {
return create(name, true);
}
/**
* Creates a named unique location identity for read and write operations.
*
* @param name the name of the new location identity
* @param immutable true if the location is immutable
*/
private static NamedLocationIdentity create(String name, boolean immutable) {
return new NamedLocationIdentity(name, immutable);
}
@Override
public boolean isImmutable() {
return immutable;
}
@Override
public String toString() {
return name + (isImmutable() ? ":final" : "");
}
/**
* Returns the named location identity for an array of the given element kind. Array accesses of
* the same kind must have the same location identity unless an alias analysis guarantees that two
* distinct arrays are accessed.
*/
public static LocationIdentity getArrayLocation(JavaKind elementKind) {
return ARRAY_LOCATIONS.get(elementKind);
}
private static final EnumMap<JavaKind, LocationIdentity> ARRAY_LOCATIONS = initArrayLocations();
private static EnumMap<JavaKind, LocationIdentity> initArrayLocations() {
EnumMap<JavaKind, LocationIdentity> result = new EnumMap<>(JavaKind.class);
for (JavaKind kind : JavaKind.values()) {
result.put(kind, NamedLocationIdentity.mutable("Array: " + kind.getJavaName()));
}
return result;
}
}