tabulation API generalization

git-svn-id: https://wala.svn.sourceforge.net/svnroot/wala/trunk@2532 f5eafffb-2e1d-0410-98e4-8ec43c5233c4

com.ibm.wala.core/src/com/ibm/wala/dataflow/IFDS/TabulationProblem.java

@@ -12,8 +12,6 @@ package com.ibm.wala.dataflow.IFDS;
 
 import java.util.Collection;
 
-import com.ibm.wala.util.collections.Pair;
-
 /**
  * 
  * Representation of a Dyck-language graph reachability problem for the 
@@ -41,10 +39,9 @@ public interface TabulationProblem<T,P> {
   public IFlowFunctionMap<T> getFunctionMap();
 
   /**
-   * Define the set of facts that are live on entry to the analysis.  Each fact represents a dataflow
+   * Define the set of path edges to start propagation with.
-   * factoid number (Integer) at a particular supergraph node (T).
    */
-  public Collection<Pair<T,Integer>> initialSeeds();
+  public Collection<PathEdge<T>> initialSeeds();
 
   /**
    * Special case: if supportsMerge(), then the problem is not really IFDS

com.ibm.wala.core/src/com/ibm/wala/dataflow/IFDS/TabulationSolver.java

@@ -29,7 +29,6 @@ import com.ibm.wala.util.collections.HashMapFactory;
 import com.ibm.wala.util.collections.HashSetFactory;
 import com.ibm.wala.util.collections.Heap;
 import com.ibm.wala.util.collections.Iterator2Collection;
-import com.ibm.wala.util.collections.Pair;
 import com.ibm.wala.util.collections.ToStringComparator;
 import com.ibm.wala.util.debug.Assertions;
 import com.ibm.wala.util.heapTrace.HeapTracer;
@@ -188,8 +187,8 @@ public class TabulationSolver<T, P> {
    * Start tabulation with the initial seeds.
    */
   protected void initialize() {
-    for (Pair<T, Integer> seed : problem.initialSeeds()) {
+    for (PathEdge<T> seed : problem.initialSeeds()) {
-      propagate(seed.fst, seed.snd, seed.fst, seed.snd);
+      propagate(seed.entry, seed.d1, seed.target, seed.d2);
     }
   }
 

com.ibm.wala.core/src/com/ibm/wala/ipa/slicer/MethodEntryStatement.java

@@ -13,11 +13,12 @@ package com.ibm.wala.ipa.slicer;
 import com.ibm.wala.ipa.callgraph.CGNode;
 
 /**
- * A statement representing method entry, used for managing
+ * A statement representing method entry, used for managing control dependence.
- * control dependence
+ * 
+ * This is also used as a dummy entry for starting propagation to a seed statement.
  * 
  * @author sjfink
- *
+ * 
  */
 public class MethodEntryStatement extends Statement {
 
@@ -31,7 +32,7 @@ public class MethodEntryStatement extends Statement {
       return false;
     }
     if (getClass().equals(obj.getClass())) {
-      MethodEntryStatement other = (MethodEntryStatement)obj;
+      MethodEntryStatement other = (MethodEntryStatement) obj;
       return getNode().equals(other.getNode());
     } else {
       return false;
@@ -40,12 +41,12 @@ public class MethodEntryStatement extends Statement {
 
   @Override
   public Kind getKind() {
-   return Kind.METHOD_ENTRY;
+    return Kind.METHOD_ENTRY;
   }
 
   @Override
   public int hashCode() {
-    return getKind().hashCode() + 9901*getNode().hashCode();
+    return getKind().hashCode() + 9901 * getNode().hashCode();
   }
 
   @Override

com.ibm.wala.core/src/com/ibm/wala/ipa/slicer/PDG.java

@@ -119,14 +119,11 @@ public class PDG implements NumberedGraph<Statement> {
   private boolean isPopulated = false;
 
   /**
-   * @param mod
+   * @param mod the set of heap locations which may be written (transitively) by this node. These are logically return
-   *            the set of heap locations which may be written (transitively) by this node. These are logically return
+   *        values in the SDG.
-   *            values in the SDG.
+   * @param ref the set of heap locations which may be read (transitively) by this node. These are logically parameters
-   * @param ref
+   *        in the SDG.
-   *            the set of heap locations which may be read (transitively) by this node. These are logically parameters
+   * @throws IllegalArgumentException if node is null
-   *            in the SDG.
-   * @throws IllegalArgumentException
-   *             if node is null
    */
   public PDG(final CGNode node, PointerAnalysis pa, Map<CGNode, OrdinalSet<PointerKey>> mod,
       Map<CGNode, OrdinalSet<PointerKey>> ref, DataDependenceOptions dOptions, ControlDependenceOptions cOptions,
@@ -135,14 +132,11 @@ public class PDG implements NumberedGraph<Statement> {
   }
 
   /**
-   * @param mod
+   * @param mod the set of heap locations which may be written (transitively) by this node. These are logically return
-   *            the set of heap locations which may be written (transitively) by this node. These are logically return
+   *        values in the SDG.
-   *            values in the SDG.
+   * @param ref the set of heap locations which may be read (transitively) by this node. These are logically parameters
-   * @param ref
+   *        in the SDG.
-   *            the set of heap locations which may be read (transitively) by this node. These are logically parameters
+   * @throws IllegalArgumentException if node is null
-   *            in the SDG.
-   * @throws IllegalArgumentException
-   *             if node is null
    */
   public PDG(final CGNode node, PointerAnalysis pa, Map<CGNode, OrdinalSet<PointerKey>> mod,
       Map<CGNode, OrdinalSet<PointerKey>> ref, DataDependenceOptions dOptions, ControlDependenceOptions cOptions,
@@ -448,7 +442,7 @@ public class PDG implements NumberedGraph<Statement> {
           Assertions.UNREACHABLE();
         }
         // TODO: this is overly conservative. deal with catch blocks?
-        for (IntIterator ii = getPEIs(ir).intIterator(); ii.hasNext(); ) {
+        for (IntIterator ii = getPEIs(ir).intIterator(); ii.hasNext();) {
           int index = ii.next();
           SSAInstruction pei = ir.getInstructions()[index];
           if (dOptions.isTerminateAtCast() && (pei instanceof SSACheckCastInstruction)) {
@@ -720,7 +714,8 @@ public class PDG implements NumberedGraph<Statement> {
     return ssaInstruction2Statement(node, s, instructionIndices);
   }
 
-  public static synchronized Statement ssaInstruction2Statement(CGNode node, SSAInstruction s, Map<SSAInstruction, Integer> instructionIndices) {
+  public static synchronized Statement ssaInstruction2Statement(CGNode node, SSAInstruction s,
+      Map<SSAInstruction, Integer> instructionIndices) {
     assert s != null;
     if (s instanceof SSAPhiInstruction) {
       SSAPhiInstruction phi = (SSAPhiInstruction) s;
@@ -800,17 +795,14 @@ public class PDG implements NumberedGraph<Statement> {
     createCalleeParams(ref);
     createReturnStatements();
 
-    if (!cOptions.equals(ControlDependenceOptions.NONE)) {
+    delegate.addNode(new MethodEntryStatement(node));
-      delegate.addNode(new MethodEntryStatement(node));
-    }
   }
 
   /**
    * create nodes representing defs of the return values
    * 
-   * @param mod
+   * @param mod the set of heap locations which may be written (transitively) by this node. These are logically
-   *            the set of heap locations which may be written (transitively) by this node. These are logically
+   *        parameters in the SDG.
-   *            parameters in the SDG.
    * @param dOptions
    */
   private void createReturnStatements() {
@@ -839,9 +831,8 @@ public class PDG implements NumberedGraph<Statement> {
   /**
    * create nodes representing defs of formal parameters
    * 
-   * @param ref
+   * @param ref the set of heap locations which may be read (transitively) by this node. These are logically parameters
-   *            the set of heap locations which may be read (transitively) by this node. These are logically parameters
+   *        in the SDG.
-   *            in the SDG.
    */
   private void createCalleeParams(Map<CGNode, OrdinalSet<PointerKey>> ref) {
     ArrayList<Statement> list = new ArrayList<Statement>();

com.ibm.wala.core/src/com/ibm/wala/ipa/slicer/SDGSupergraph.java

@@ -178,7 +178,7 @@ class SDGSupergraph implements ISupergraph<Statement, PDG> {
    */
   public Statement getMainEntry() {
     Assertions.productionAssertion(!backward, "todo: support backward");
-    return srcStatement;
+    return new MethodEntryStatement(srcStatement.getNode());
   }
 
   /*
@@ -188,7 +188,7 @@ class SDGSupergraph implements ISupergraph<Statement, PDG> {
     // We pretend that sink is the "main exit" .. we don't care about
     // flow past the sink.
     Assertions.productionAssertion(backward, "todo: support forward");
-    return srcStatement;
+    return new MethodEntryStatement(srcStatement.getNode());
   }
 
   /*

com.ibm.wala.core/src/com/ibm/wala/ipa/slicer/Slicer.java

@@ -18,6 +18,7 @@ import com.ibm.wala.dataflow.IFDS.BackwardsSupergraph;
 import com.ibm.wala.dataflow.IFDS.IFlowFunctionMap;
 import com.ibm.wala.dataflow.IFDS.IMergeFunction;
 import com.ibm.wala.dataflow.IFDS.ISupergraph;
+import com.ibm.wala.dataflow.IFDS.PathEdge;
 import com.ibm.wala.dataflow.IFDS.TabulationDomain;
 import com.ibm.wala.dataflow.IFDS.TabulationProblem;
 import com.ibm.wala.dataflow.IFDS.TabulationResult;
@@ -28,7 +29,6 @@ import com.ibm.wala.ipa.callgraph.propagation.PointerAnalysis;
 import com.ibm.wala.ipa.modref.ModRef;
 import com.ibm.wala.util.collections.HashSetFactory;
 import com.ibm.wala.util.collections.Iterator2Collection;
-import com.ibm.wala.util.collections.Pair;
 import com.ibm.wala.util.debug.Assertions;
 
 /**
@@ -419,8 +419,8 @@ public class Slicer {
       return supergraph;
     }
 
-    public Collection<Pair<Statement, Integer>> initialSeeds() {
+    public Collection<PathEdge<Statement>> initialSeeds() {
-      Pair<Statement,Integer> seed = Pair.make(src, 0);
+      PathEdge<Statement> seed = PathEdge.createPathEdge(new MethodEntryStatement(src.getNode()), 0, src, 0);
       return Collections.singleton(seed);
     }
   }