Fix #176.

New precondition failure for when N is too small. Also, remove
workaround for #80 (it's not accurate).

Author: khatchad

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/analysis/PreconditionFailure.java

@@ -19,7 +19,8 @@ public enum PreconditionFailure {
 	CURRENTLY_NOT_HANDLED(14), // should just be #97 currently.
 	STREAM_CODE_NOT_REACHABLE(15), // either pivotal code isn't reachable or
 									// entry points are misconfigured.
-	NO_ENTRY_POINT(16); // user didn't specify entry points.
+	NO_ENTRY_POINT(16), // user didn't specify entry points.
+	NO_APPLICATION_CODE_IN_CALL_STRINGS(17); // N may be too small.
 
 	private int code;
 

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/analysis/Stream.java

@@ -59,6 +59,7 @@
 import com.ibm.wala.types.TypeReference;
 import com.ibm.wala.util.CancelException;
 
+import edu.cuny.hunter.streamrefactoring.core.safe.NoApplicationCodeExistsInCallStringsException;
 import edu.cuny.hunter.streamrefactoring.core.utils.LoggerNames;
 import edu.cuny.hunter.streamrefactoring.core.utils.Util;
 import edu.cuny.hunter.streamrefactoring.core.wala.EclipseProjectAnalysisEngine;
@@ -422,18 +423,33 @@ protected Ordering getInitialOrdering() {
 	}
 
 	public InstanceKey getInstanceKey(Collection<InstanceKey> trackedInstances,
-			EclipseProjectAnalysisEngine<InstanceKey> engine) throws InvalidClassFileException, IOException,
-			CoreException, InstanceKeyNotFoundException, UnhandledCaseException {
-		if (instanceKey == null) {
-			instanceKey = this.getInstructionForCreation(engine)
-					.flatMap(instruction -> trackedInstances.stream()
-							.filter(ik -> instanceKeyCorrespondsWithInstantiationInstruction(ik, instruction,
-									this.getEnclosingMethodReference(), engine.getCallGraph()))
-							.findFirst())
-					.orElseThrow(() -> new InstanceKeyNotFoundException("Can't find instance key for: "
-							+ this.getCreation() + " using tracked instances: " + trackedInstances));
+			EclipseProjectAnalysisEngine<InstanceKey> engine)
+			throws InvalidClassFileException, IOException, CoreException, InstanceKeyNotFoundException,
+			UnhandledCaseException, NoApplicationCodeExistsInCallStringsException {
+		// if not present.
+		if (this.instanceKey == null)
+			// compute it.
+			this.instanceKey = computeInstanceKey(trackedInstances, engine);
+		return this.instanceKey;
+	}
+
+	protected InstanceKey computeInstanceKey(Collection<InstanceKey> trackedInstances,
+			EclipseProjectAnalysisEngine<InstanceKey> engine)
+			throws InvalidClassFileException, IOException, CoreException, UnhandledCaseException,
+			NoApplicationCodeExistsInCallStringsException, InstanceKeyNotFoundException {
+		Optional<SSAInvokeInstruction> instructionForCreation = this.getInstructionForCreation(engine);
+
+		if (instructionForCreation.isPresent()) {
+			SSAInvokeInstruction instruction = instructionForCreation.get();
+
+			for (InstanceKey ik : trackedInstances)
+				if (instanceKeyCorrespondsWithInstantiationInstruction(ik, instruction,
+						this.getEnclosingMethodReference(), engine.getCallGraph()))
+					return ik;
 		}
-		return instanceKey;
+
+		throw new InstanceKeyNotFoundException(
+				"Can't find instance key for: " + this.getCreation() + " using tracked instances: " + trackedInstances);
 	}
 
 	Optional<SSAInvokeInstruction> getInstructionForCreation(EclipseProjectAnalysisEngine<InstanceKey> engine)

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/analysis/StreamStateMachine.java

@@ -82,6 +82,7 @@
 import com.ibm.wala.util.strings.Atom;
 
 import edu.cuny.hunter.streamrefactoring.core.safe.ModifiedBenignOracle;
+import edu.cuny.hunter.streamrefactoring.core.safe.NoApplicationCodeExistsInCallStringsException;
 import edu.cuny.hunter.streamrefactoring.core.safe.TypestateSolverFactory;
 import edu.cuny.hunter.streamrefactoring.core.utils.LoggerNames;
 import edu.cuny.hunter.streamrefactoring.core.wala.CallStringWithReceivers;
@@ -866,18 +867,28 @@ private void fillInstanceToStreamMap(Set<Stream> streamSet, EclipseProjectAnalys
 			try {
 				instanceKey = stream.getInstanceKey(this.trackedInstances, engine);
 			} catch (InstanceKeyNotFoundException e) {
-				LOGGER.log(Level.WARNING, "Encountered unreachable code while processing: " + stream.getCreation(), e);
+				LOGGER.log(Level.WARNING,
+						"Encountered unreachable code while processing: " + stream.getCreation() + ".", e);
 				stream.addStatusEntry(PreconditionFailure.STREAM_CODE_NOT_REACHABLE,
 						"Either pivital code isn't reachable for stream: " + stream.getCreation()
 								+ " or entry points are misconfigured.");
 				++skippedStreams;
 				continue; // next stream.
 			} catch (UnhandledCaseException e) {
-				String msg = "Encountered possible unhandled case (AIC #155) while processing: " + stream.getCreation();
+				String msg = "Encountered possible unhandled case (AIC #155) while processing: " + stream.getCreation()
+						+ ".";
 				LOGGER.log(Level.WARNING, msg, e);
 				stream.addStatusEntry(PreconditionFailure.CURRENTLY_NOT_HANDLED, msg);
 				++skippedStreams;
 				continue; // next stream.
+			} catch (NoApplicationCodeExistsInCallStringsException e) {
+				LOGGER.log(Level.WARNING, "Did not encounter application code in call strings while processing: "
+						+ stream.getCreation() + ".", e);
+				stream.addStatusEntry(PreconditionFailure.NO_APPLICATION_CODE_IN_CALL_STRINGS,
+						"No application code in the call strings generated for stream: " + stream.getCreation()
+								+ " was found. The maximum call string length may need to be increased.");
+				++skippedStreams;
+				continue; // next stream.
 			}
 
 			// add the mapping.

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/safe/InstructionBasedSolver.java

@@ -2,6 +2,7 @@
 
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.ibm.safe.internal.exceptions.PropertiesException;
@@ -43,9 +44,14 @@ protected Collection<InstanceKey> computeTrackedInstances() throws PropertiesExc
 
 		for (InstanceKey instanceKey : trackedInstancesByType) {
 			LOGGER.info("Examining instance: " + instanceKey);
-			if (Util.instanceKeyCorrespondsWithInstantiationInstruction(instanceKey, this.getInstruction(), null,
-					this.getCallGraph()))
-				ret.add(instanceKey);
+			try {
+				if (Util.instanceKeyCorrespondsWithInstantiationInstruction(instanceKey, this.getInstruction(), null,
+						this.getCallGraph()))
+					ret.add(instanceKey);
+			} catch (NoApplicationCodeExistsInCallStringsException e) {
+				LOGGER.log(Level.SEVERE, e, () -> "Encountered NoApplicationCodeExistsInCallStringsException.");
+				throw new RuntimeException(e);
+			}
 		}
 
 		if (ret.size() != 1)

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/safe/NoApplicationCodeExistsInCallStringsException.java

@@ -0,0 +1,21 @@
+package edu.cuny.hunter.streamrefactoring.core.safe;
+
+public class NoApplicationCodeExistsInCallStringsException extends Exception {
+
+	public NoApplicationCodeExistsInCallStringsException(String message) {
+		super(message);
+	}
+
+	public NoApplicationCodeExistsInCallStringsException(Throwable cause) {
+		super(cause);
+	}
+
+	public NoApplicationCodeExistsInCallStringsException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+	public NoApplicationCodeExistsInCallStringsException(String message, Throwable cause, boolean enableSuppression,
+			boolean writableStackTrace) {
+		super(message, cause, enableSuppression, writableStackTrace);
+	}
+}

edu.cuny.hunter.streamrefactoring.core/src/edu/cuny/hunter/streamrefactoring/core/safe/Util.java

@@ -4,6 +4,7 @@
 import java.util.logging.Logger;
 
 import com.ibm.wala.classLoader.CallSiteReference;
+import com.ibm.wala.classLoader.IClassLoader;
 import com.ibm.wala.classLoader.IMethod;
 import com.ibm.wala.classLoader.NewSiteReference;
 import com.ibm.wala.ipa.callgraph.CGNode;
@@ -13,28 +14,33 @@
 import com.ibm.wala.ipa.callgraph.propagation.cfa.CallString;
 import com.ibm.wala.ipa.callgraph.propagation.cfa.CallStringContextSelector;
 import com.ibm.wala.ssa.SSAInvokeInstruction;
+import com.ibm.wala.types.ClassLoaderReference;
 import com.ibm.wala.types.MethodReference;
 import com.ibm.wala.types.TypeName;
 import com.ibm.wala.util.collections.Pair;
 import com.ibm.wala.util.strings.Atom;
 
 import edu.cuny.hunter.streamrefactoring.core.utils.LoggerNames;
+import edu.cuny.hunter.streamrefactoring.core.wala.nCFAContextWithReceiversSelector;
 
 public class Util {
 
 	/**
 	 * The {@link TypeName} of the type {@link java.util.Arrays}.
 	 */
+	@SuppressWarnings("unused")
 	private static final TypeName ARRAYS_TYPE_NAME = TypeName.string2TypeName("Ljava/util/Arrays");
 
 	/**
 	 * {@link Atom} corresponding the the stream() method.
 	 */
+	@SuppressWarnings("unused")
 	private static final Atom STREAM_METHOD_NAME_ATOM = Atom.findOrCreateAsciiAtom("stream");
 
 	/**
 	 * The {@link TypeName} for the type {@link java.util.stream.StreamSupport}.
 	 */
+	@SuppressWarnings("unused")
 	private static final TypeName STREAM_SUPPORT_TYPE_NAME = TypeName
 			.string2TypeName("Ljava/util/stream/StreamSupport");
 
@@ -54,16 +60,23 @@ public class Util {
 	 *            The corresponding call graph.
 	 * @return True iff the given instruction was used to instantiate the given
 	 *         instance key according to the given call graph.
+	 * @throws NoApplicationCodeExistsInCallStringsException
+	 *             Iff application code was not found while processing call strings.
 	 */
 	public static boolean instanceKeyCorrespondsWithInstantiationInstruction(InstanceKey instanceKey,
-			SSAInvokeInstruction instruction, MethodReference instructionEnclosingMethod, CallGraph callGraph) {
+			SSAInvokeInstruction instruction, MethodReference instructionEnclosingMethod, CallGraph callGraph)
+			throws NoApplicationCodeExistsInCallStringsException {
 		// Creation sites for the instance with the given key in the given call
 		// graph.
 		Iterator<Pair<CGNode, NewSiteReference>> creationSites = instanceKey.getCreationSites(callGraph);
 
 		CallSiteReference instructionCallSite = instruction.getCallSite();
 		LOGGER.fine("instruction call site is: " + instructionCallSite);
 
+		// did we see an application code entity in a call string? If not, this could
+		// indicate that N is too small.
+		boolean applicationCodeInCallString = false;
+
 		// for each creation site.
 		while (creationSites.hasNext()) {
 			Pair<CGNode, NewSiteReference> pair = creationSites.next();
@@ -89,6 +102,21 @@ public static boolean instanceKeyCorrespondsWithInstantiationInstruction(Instanc
 				IMethod method = methods[i];
 				LOGGER.fine("Method at " + i + " is: " + method);
 
+				// if we haven't encountered application code in the call string yet.
+				if (!applicationCodeInCallString) {
+					// get the class loaders.
+					ClassLoaderReference callSiteReferenceClassLoader = callSiteReference.getDeclaredTarget()
+							.getDeclaringClass().getClassLoader();
+					IClassLoader methodClassLoader = method.getDeclaringClass().getClassLoader();
+
+					// if either the call site reference class loader or the (enclosing) method
+					// class loader is of type Application.
+					if (callSiteReferenceClassLoader.equals(ClassLoaderReference.Application)
+							|| methodClassLoader.equals(ClassLoaderReference.Application))
+						// then, we've seen application code.
+						applicationCodeInCallString = true;
+				}
+
 				// if the call site reference equals the call site corresponding
 				// to the creation instruction.
 				if (callSiteReference.equals(instructionCallSite)
@@ -97,27 +125,18 @@ public static boolean instanceKeyCorrespondsWithInstantiationInstruction(Instanc
 							+ instruction + ".");
 					return true;
 				}
-				// workaround #80.
-				else if (callSiteReference.getProgramCounter() == instructionCallSite.getProgramCounter()) {
-					// compare declared targets.
-					MethodReference callSiteDeclaredTarget = callSiteReference.getDeclaredTarget();
-					TypeName callSiteTargetDeclaringClassName = callSiteDeclaredTarget.getDeclaringClass().getName();
-
-					MethodReference instructionCallDeclaredTarget = instructionCallSite.getDeclaredTarget();
-					TypeName instructionTargetDeclaringClassName = instructionCallDeclaredTarget.getDeclaringClass()
-							.getName();
-
-					if (callSiteTargetDeclaringClassName.equals(instructionTargetDeclaringClassName)
-							&& (callSiteTargetDeclaringClassName.equals(ARRAYS_TYPE_NAME)
-									|| callSiteTargetDeclaringClassName.equals(STREAM_SUPPORT_TYPE_NAME))
-							&& callSiteDeclaredTarget.getName().equals(instructionCallDeclaredTarget.getName())
-							&& callSiteDeclaredTarget.getName().equals(STREAM_METHOD_NAME_ATOM))
-						return true;
-				}
 			}
 		}
 		LOGGER.fine("No match found. Instance key: " + instanceKey + " does not correspond with instruction: "
 				+ instruction + ".");
+
+		// if we did not encounter application code in the call strings.
+		if (!applicationCodeInCallString)
+			throw new NoApplicationCodeExistsInCallStringsException(
+					"Could not find application code in call string while processing instance key: " + instanceKey
+							+ " and instruction: " + instruction + ". This may indicate that the current value of N ("
+							+ nCFAContextWithReceiversSelector.CONTEXT_LENGTH_FOR_STREAMS + ") is too small.");
+
 		return false;
 	}
 

edu.cuny.hunter.streamrefactoring.tests/test cases/edu/cuny/hunter/streamrefactoring/ui/tests/ConvertStreamToParallelRefactoringTest.java

@@ -383,8 +383,8 @@ public void testEntrySet4() throws Exception {
 	public void testArraysStream() throws Exception {
 		helper(new StreamAnalysisExpectedResult("Arrays.stream(new Object[1])",
 				Collections.singleton(ExecutionMode.SEQUENTIAL), EnumSet.of(Ordering.ORDERED), false, false, false,
-				EnumSet.of(TransformationAction.CONVERT_TO_PARALLEL), PreconditionSuccess.P2,
-				Refactoring.CONVERT_SEQUENTIAL_STREAM_TO_PARALLEL, RefactoringStatus.OK, Collections.emptySet()));
+				null, null, null, RefactoringStatus.ERROR,
+				EnumSet.of(PreconditionFailure.NO_APPLICATION_CODE_IN_CALL_STRINGS)));
 	}
 
 	public void testConstructor() throws Exception {