renamed JoinLattice to MeetLattice and joinWith to meetWith etc. beca…

…use previously it was all rather confusion: we are, in fact, implementing a meet lattice, so we should also name it that way

src/heros/EdgeFunction.java

@@ -36,12 +36,12 @@ public interface EdgeFunction<V> {
 	EdgeFunction<V> composeWith(EdgeFunction<V> secondFunction);
 
 	/**
-	 * Returns a function that represents that (element-wise) join
+	 * Returns a function that represents that (element-wise) meet
 	 * of this function with otherFunction. Naturally, this is a
 	 * symmetric operation.
-	 * @see JoinLattice#join(Object, Object)
+	 * @see MeetLattice#meet(Object, Object)
 	 */
-	EdgeFunction<V> joinWith(EdgeFunction<V> otherFunction);
+	EdgeFunction<V> meetWith(EdgeFunction<V> otherFunction);
 
 	/**
 	 * Returns true is this function represents exactly the same 

src/heros/IDETabulationProblem.java

@@ -17,8 +17,8 @@
  * of type D maps at any program point to a value of type V. The functions describe how
  * values are transformed when moving from one statement to another.
  * 
- * The problem further defines a {@link JoinLattice}, which describes how values of
- * type V are joined (merged) when multiple values are possible.
+ * The problem further defines a {@link MeetLattice}, which describes how values of
+ * type V are merged (via a meet operation) when multiple values are possible.
  *
  * @param <N> The type of nodes in the interprocedural control-flow graph. Typically {@link Unit}.
  * @param <D> The type of data-flow facts to be computed by the tabulation problem.
@@ -35,9 +35,9 @@ public interface IDETabulationProblem<N,D,M,V,I extends InterproceduralCFG<N,M>>
 	EdgeFunctions<N,D,M,V> edgeFunctions();
 
 	/**
-	 * Returns the lattice describing how values of type V need to be joined.
+	 * Returns the lattice describing how to compute the meet of two V values.
 	 */
-	JoinLattice<V> joinLattice();
+	MeetLattice<V> meetLattice();
 
 	/**
 	 * Returns a function mapping everything to top.

src/heros/JoinLattice.java → src/heros/MeetLattice.java

@@ -12,16 +12,26 @@
 
 /**
  * This class defines a lattice in terms of its top and bottom elements
- * and a join operation. 
+ * and a meet operation. This is meant to be a complete lattice, with a unique top and bottom element. 
  *
  * @param <V> The domain type for this lattice.
  */
-public interface JoinLattice<V> {
+public interface MeetLattice<V> {
 
+	/**
+	 * Returns the unique top element of this lattice.
+	 */
 	V topElement();
 
+	/**
+	 * Returns the unique bottom element of this lattice.
+	 */
 	V bottomElement();
 
-	V join(V left, V right);
+	/**
+	 * Computes the meet of left and right. Note that <pre>meet(top,x) = meet(x,top) = x</pre> and
+	 * <pre>meet(bottom,x) = meet(x,bottom) = bottom</pre>. 
+	 */
+	V meet(V left, V right);
 
 }

src/heros/edgefunc/AllBottom.java

@@ -31,7 +31,7 @@ public EdgeFunction<V> composeWith(EdgeFunction<V> secondFunction) {
 		return secondFunction;
 	}
 
-	public EdgeFunction<V> joinWith(EdgeFunction<V> otherFunction) {
+	public EdgeFunction<V> meetWith(EdgeFunction<V> otherFunction) {
 		if(otherFunction == this || otherFunction.equalTo(this)) return this;
 		if(otherFunction instanceof AllTop) {
 			return this;

src/heros/edgefunc/AllTop.java

@@ -29,7 +29,7 @@ public EdgeFunction<V> composeWith(EdgeFunction<V> secondFunction) {
 		return this;
 	}
 
-	public EdgeFunction<V> joinWith(EdgeFunction<V> otherFunction) {
+	public EdgeFunction<V> meetWith(EdgeFunction<V> otherFunction) {
 		return otherFunction;
 	}
 

src/heros/edgefunc/EdgeIdentity.java

@@ -31,16 +31,16 @@ public EdgeFunction<V> composeWith(EdgeFunction<V> secondFunction) {
 		return secondFunction;
 	}
 
-	public EdgeFunction<V> joinWith(EdgeFunction<V> otherFunction) {
+	public EdgeFunction<V> meetWith(EdgeFunction<V> otherFunction) {
 		if(otherFunction == this || otherFunction.equalTo(this)) return this;
 		if(otherFunction instanceof AllBottom) {
 			return otherFunction;
 		}
 		if(otherFunction instanceof AllTop) {
 			return this;
 		}
-		//do not know how to join; hence ask other function to decide on this
-		return otherFunction.joinWith(this);
+		//do not know how to meet; hence ask other function to decide on this
+		return otherFunction.meetWith(this);
 	}
 
 	public boolean equalTo(EdgeFunction<V> other) {

src/heros/solver/BiDiIDESolver.java

@@ -17,7 +17,7 @@
 import heros.IDETabulationProblem;
 import heros.IFDSTabulationProblem;
 import heros.InterproceduralCFG;
-import heros.JoinLattice;
+import heros.MeetLattice;
 import heros.solver.IFDSSolver.BinaryDomain;
 
 import java.util.Collections;
@@ -479,8 +479,8 @@ public EdgeFunction<V> getCallToReturnEdgeFunction(N callSite, AbstractionWithSo
 		}
 
 		@Override
-		public JoinLattice<V> joinLattice() {
-			return delegate.joinLattice();
+		public MeetLattice<V> meetLattice() {
+			return delegate.meetLattice();
 		}
 
 		@Override

src/heros/solver/IDESolver.java

@@ -23,7 +23,7 @@
 import heros.FlowFunctions;
 import heros.IDETabulationProblem;
 import heros.InterproceduralCFG;
-import heros.JoinLattice;
+import heros.MeetLattice;
 import heros.SynchronizedBy;
 import heros.ZeroedFlowFunctions;
 import heros.edgefunc.EdgeIdentity;
@@ -117,7 +117,7 @@ public class IDESolver<N,D,M,V,I extends InterproceduralCFG<N, M>> {
 	protected final Map<N,Set<D>> initialSeeds;
 
 	@DontSynchronize("stateless")
-	protected final JoinLattice<V> valueLattice;
+	protected final MeetLattice<V> valueLattice;
 
 	@DontSynchronize("stateless")
 	protected final EdgeFunction<V> allTop;
@@ -199,7 +199,7 @@ public IDESolver(IDETabulationProblem<N,D,M,V,I> tabulationProblem, @SuppressWar
 		this.edgeFunctions = edgeFunctions;
 		this.initialSeeds = tabulationProblem.initialSeeds();
 		this.unbalancedRetSites = Collections.newSetFromMap(new ConcurrentHashMap<N, Boolean>());
-		this.valueLattice = tabulationProblem.joinLattice();
+		this.valueLattice = tabulationProblem.meetLattice();
 		this.allTop = tabulationProblem.allTopFunction();
 		this.jumpFn = new JumpFunctions<N,D,V>(allTop);
 		this.followReturnsPastSeeds = tabulationProblem.followReturnsPastSeeds();
@@ -640,7 +640,7 @@ protected void propagate(D sourceVal, N target, D targetVal, EdgeFunction<V> f,
 		synchronized (jumpFn) {
 			jumpFnE = jumpFn.reverseLookup(target, targetVal).get(sourceVal);
 			if(jumpFnE==null) jumpFnE = allTop; //JumpFn is initialized to all-top (see line [2] in SRH96 paper)
-			fPrime = jumpFnE.joinWith(f);
+			fPrime = jumpFnE.meetWith(f);
 			newFunction = !fPrime.equalTo(jumpFnE);
 			if(newFunction) {
 				jumpFn.addFunction(sourceVal, target, targetVal, fPrime);
@@ -746,14 +746,14 @@ private void propagateValueAtCall(Pair<N, D> nAndD, N n) {
 		}
 	}
 
-	protected V joinValueAt(N unit, D fact, V curr, V newVal) {
-		return valueLattice.join(curr, newVal);
+	protected V meetValueAt(N unit, D fact, V curr, V newVal) {
+		return valueLattice.meet(curr, newVal);
 	}
 
 	private void propagateValue(N nHashN, D nHashD, V v) {
 		synchronized (val) {
 			V valNHash = val(nHashN, nHashD);
-			V vPrime = joinValueAt(nHashN, nHashD, valNHash,v);
+			V vPrime = meetValueAt(nHashN, nHashD, valNHash,v);
 			if(!vPrime.equals(valNHash)) {
 				setVal(nHashN, nHashD, vPrime);
 				scheduleValueProcessing(new ValuePropagationTask(new Pair<N,D>(nHashN,nHashD)));
@@ -946,7 +946,7 @@ public void run() {
 						D d = sourceValTargetValAndFunction.getColumnKey();
 						EdgeFunction<V> fPrime = sourceValTargetValAndFunction.getValue();
 						synchronized (val) {
-							setVal(n,d,valueLattice.join(val(n,d),fPrime.computeTarget(val(sP,dPrime))));
+							setVal(n,d,valueLattice.meet(val(n,d),fPrime.computeTarget(val(sP,dPrime))));
 						}
 						flowFunctionApplicationCount++;
 					}

src/heros/solver/IFDSSolver.java

@@ -18,7 +18,7 @@
 import heros.IDETabulationProblem;
 import heros.IFDSTabulationProblem;
 import heros.InterproceduralCFG;
-import heros.JoinLattice;
+import heros.MeetLattice;
 import heros.edgefunc.AllBottom;
 import heros.edgefunc.AllTop;
 import heros.edgefunc.EdgeIdentity;
@@ -76,8 +76,8 @@ public EdgeFunctions<N,D,M,BinaryDomain> edgeFunctions() {
 				return new IFDSEdgeFunctions();
 			}
 
-			public JoinLattice<BinaryDomain> joinLattice() {
-				return new JoinLattice<BinaryDomain>() {
+			public MeetLattice<BinaryDomain> meetLattice() {
+				return new MeetLattice<BinaryDomain>() {
 
 					public BinaryDomain topElement() {
 						return BinaryDomain.TOP;
@@ -87,7 +87,7 @@ public BinaryDomain bottomElement() {
 						return BinaryDomain.BOTTOM;
 					}
 
-					public BinaryDomain join(BinaryDomain left, BinaryDomain right) {
+					public BinaryDomain meet(BinaryDomain left, BinaryDomain right) {
 						if(left==TOP && right==TOP) {
 							return TOP;
 						} else {

src/heros/template/DefaultIDETabulationProblem.java

@@ -14,7 +14,7 @@
 import heros.EdgeFunctions;
 import heros.IDETabulationProblem;
 import heros.InterproceduralCFG;
-import heros.JoinLattice;
+import heros.MeetLattice;
 
 /**
  * This is a template for {@link IDETabulationProblem}s that automatically caches values
@@ -31,7 +31,7 @@ public abstract class DefaultIDETabulationProblem<N,D,M,V,I extends Interprocedu
     extends DefaultIFDSTabulationProblem<N,D,M,I> implements IDETabulationProblem<N,D,M,V,I>{
 
 	private final EdgeFunction<V> allTopFunction;
-	private final JoinLattice<V> joinLattice;
+	private final MeetLattice<V> joinLattice;
 	private final EdgeFunctions<N,D,M,V> edgeFunctions;
 
 	public DefaultIDETabulationProblem(I icfg) {
@@ -43,7 +43,7 @@ public DefaultIDETabulationProblem(I icfg) {
 
 	protected abstract EdgeFunction<V> createAllTopFunction();
 
-	protected abstract JoinLattice<V> createJoinLattice();
+	protected abstract MeetLattice<V> createJoinLattice();
 
 	protected abstract EdgeFunctions<N,D,M,V> createEdgeFunctionsFactory();
 
@@ -53,7 +53,7 @@ public final EdgeFunction<V> allTopFunction() {
 	}
 
 	@Override
-	public final JoinLattice<V> joinLattice() {
+	public final MeetLattice<V> meetLattice() {
 		return joinLattice;
 	}