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package org.checkerframework.dataflow.constantpropagation;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import org.checkerframework.dataflow.analysis.FlowExpressions;
import org.checkerframework.dataflow.analysis.Store;
import org.checkerframework.dataflow.cfg.CFGVisualizer;
import org.checkerframework.dataflow.cfg.node.IntegerLiteralNode;
import org.checkerframework.dataflow.cfg.node.LocalVariableNode;
import org.checkerframework.dataflow.cfg.node.Node;
import org.checkerframework.dataflow.constantpropagation.Constant.Type;
public class ConstantPropagationStore implements Store<ConstantPropagationStore> {
/** Information about variables gathered so far. */
Map<Node, Constant> contents;
public ConstantPropagationStore() {
contents = new HashMap<>();
}
protected ConstantPropagationStore(Map<Node, Constant> contents) {
this.contents = contents;
}
public Constant getInformation(Node n) {
if (contents.containsKey(n)) {
return contents.get(n);
}
return new Constant(Type.TOP);
}
public void mergeInformation(Node n, Constant val) {
Constant value;
if (contents.containsKey(n)) {
value = val.leastUpperBound(contents.get(n));
} else {
value = val;
}
// TODO: remove (only two nodes supported atm)
assert n instanceof IntegerLiteralNode || n instanceof LocalVariableNode;
contents.put(n, value);
}
public void setInformation(Node n, Constant val) {
// TODO: remove (only two nodes supported atm)
assert n instanceof IntegerLiteralNode || n instanceof LocalVariableNode;
contents.put(n, val);
}
@Override
public ConstantPropagationStore copy() {
return new ConstantPropagationStore(new HashMap<>(contents));
}
@Override
public ConstantPropagationStore leastUpperBound(ConstantPropagationStore other) {
Map<Node, Constant> newContents = new HashMap<>();
// go through all of the information of the other class
for (Entry<Node, Constant> e : other.contents.entrySet()) {
Node n = e.getKey();
Constant otherVal = e.getValue();
if (contents.containsKey(n)) {
// merge if both contain information about a variable
newContents.put(n, otherVal.leastUpperBound(contents.get(n)));
} else {
// add new information
newContents.put(n, otherVal);
}
}
for (Entry<Node, Constant> e : contents.entrySet()) {
Node n = e.getKey();
Constant thisVal = e.getValue();
if (!other.contents.containsKey(n)) {
// add new information
newContents.put(n, thisVal);
}
}
return new ConstantPropagationStore(newContents);
}
@Override
public ConstantPropagationStore widenedUpperBound(ConstantPropagationStore previous) {
return leastUpperBound(previous);
}
@Override
public boolean equals(Object o) {
if (o == null) {
return false;
}
if (!(o instanceof ConstantPropagationStore)) {
return false;
}
ConstantPropagationStore other = (ConstantPropagationStore) o;
// go through all of the information of the other object
for (Entry<Node, Constant> e : other.contents.entrySet()) {
Node n = e.getKey();
Constant otherVal = e.getValue();
if (otherVal.isBottom()) {
continue; // no information
}
if (contents.containsKey(n)) {
if (!otherVal.equals(contents.get(n))) {
return false;
}
} else {
return false;
}
}
// go through all of the information of the this object
for (Entry<Node, Constant> e : contents.entrySet()) {
Node n = e.getKey();
Constant thisVal = e.getValue();
if (thisVal.isBottom()) {
continue; // no information
}
if (other.contents.containsKey(n)) {
continue;
} else {
return false;
}
}
return true;
}
@Override
public int hashCode() {
int s = 0;
for (Entry<Node, Constant> e : contents.entrySet()) {
if (!e.getValue().isBottom()) {
s += e.hashCode();
}
}
return s;
}
@Override
public String toString() {
// only output local variable information
Map<Node, Constant> smallerContents = new HashMap<>();
for (Entry<Node, Constant> e : contents.entrySet()) {
if (e.getKey() instanceof LocalVariableNode) {
smallerContents.put(e.getKey(), e.getValue());
}
}
return smallerContents.toString();
}
@Override
public boolean canAlias(FlowExpressions.Receiver a, FlowExpressions.Receiver b) {
return true;
}
@Override
public void visualize(CFGVisualizer<?, ConstantPropagationStore, ?> viz) {
// Do nothing since ConstantPropagationStore doesn't support visualize
}
}
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