Example #1
0
 private void markDeadInstructions() {
   Set<Instruction> instructionSet = Sets.newHashSet(instructions);
   for (Instruction instruction : mutableInstructionList) {
     if (!instructionSet.contains(instruction)) {
       ((InstructionImpl) instruction).setMarkedAsDead(true);
       for (Instruction nextInstruction : instruction.getNextInstructions()) {
         nextInstruction.getPreviousInstructions().remove(instruction);
       }
     }
   }
 }
Example #2
0
 private Set<Instruction> collectReachableInstructions() {
   Set<Instruction> visited = Sets.newHashSet();
   PseudocodeTraverserKt.traverseFollowingInstructions(
       getEnterInstruction(), visited, FORWARD, null);
   if (!visited.contains(getExitInstruction())) {
     visited.add(getExitInstruction());
   }
   if (!visited.contains(errorInstruction)) {
     visited.add(errorInstruction);
   }
   if (!visited.contains(getSinkInstruction())) {
     visited.add(getSinkInstruction());
   }
   return visited;
 }
Example #3
0
public class PseudocodeImpl implements Pseudocode {

  public class PseudocodeLabel implements Label {
    private final String name;
    private final String comment;
    private Integer targetInstructionIndex;

    private PseudocodeLabel(@NotNull String name, @Nullable String comment) {
      this.name = name;
      this.comment = comment;
    }

    @NotNull
    @Override
    public String getName() {
      return name;
    }

    @Override
    public String toString() {
      return comment == null ? name : (name + " [" + comment + "]");
    }

    public Integer getTargetInstructionIndex() {
      return targetInstructionIndex;
    }

    public void setTargetInstructionIndex(int targetInstructionIndex) {
      this.targetInstructionIndex = targetInstructionIndex;
    }

    @Nullable
    private List<Instruction> resolve() {
      assert targetInstructionIndex != null;
      return mutableInstructionList.subList(
          getTargetInstructionIndex(), mutableInstructionList.size());
    }

    public Instruction resolveToInstruction() {
      assert targetInstructionIndex != null;
      return mutableInstructionList.get(targetInstructionIndex);
    }

    public PseudocodeLabel copy(int newLabelIndex) {
      return new PseudocodeLabel("L" + newLabelIndex, "copy of " + name + ", " + comment);
    }

    public PseudocodeImpl getPseudocode() {
      return PseudocodeImpl.this;
    }
  }

  private final List<Instruction> mutableInstructionList = new ArrayList<Instruction>();
  private final List<Instruction> instructions = new ArrayList<Instruction>();

  private final BidirectionalMap<KtElement, PseudoValue> elementsToValues =
      new BidirectionalMap<KtElement, PseudoValue>();

  private final Map<PseudoValue, List<Instruction>> valueUsages = Maps.newHashMap();
  private final Map<PseudoValue, Set<PseudoValue>> mergedValues = Maps.newHashMap();
  private final Set<Instruction> sideEffectFree = Sets.newHashSet();

  private Pseudocode parent = null;
  private Set<LocalFunctionDeclarationInstruction> localDeclarations = null;
  // todo getters
  private final Map<KtElement, Instruction> representativeInstructions =
      new HashMap<KtElement, Instruction>();

  private final List<PseudocodeLabel> labels = new ArrayList<PseudocodeLabel>();

  private final KtElement correspondingElement;
  private SubroutineExitInstruction exitInstruction;
  private SubroutineSinkInstruction sinkInstruction;
  private SubroutineExitInstruction errorInstruction;
  private boolean postPrecessed = false;

  public PseudocodeImpl(KtElement correspondingElement) {
    this.correspondingElement = correspondingElement;
  }

  @NotNull
  @Override
  public KtElement getCorrespondingElement() {
    return correspondingElement;
  }

  @NotNull
  @Override
  public Set<LocalFunctionDeclarationInstruction> getLocalDeclarations() {
    if (localDeclarations == null) {
      localDeclarations = getLocalDeclarations(this);
    }
    return localDeclarations;
  }

  @NotNull
  private static Set<LocalFunctionDeclarationInstruction> getLocalDeclarations(
      @NotNull Pseudocode pseudocode) {
    Set<LocalFunctionDeclarationInstruction> localDeclarations = Sets.newLinkedHashSet();
    for (Instruction instruction : ((PseudocodeImpl) pseudocode).mutableInstructionList) {
      if (instruction instanceof LocalFunctionDeclarationInstruction) {
        localDeclarations.add((LocalFunctionDeclarationInstruction) instruction);
        localDeclarations.addAll(
            getLocalDeclarations(((LocalFunctionDeclarationInstruction) instruction).getBody()));
      }
    }
    return localDeclarations;
  }

  @Override
  @Nullable
  public Pseudocode getParent() {
    return parent;
  }

  private void setParent(Pseudocode parent) {
    this.parent = parent;
  }

  @NotNull
  public Pseudocode getRootPseudocode() {
    Pseudocode parent = getParent();
    while (parent != null) {
      if (parent.getParent() == null) return parent;
      parent = parent.getParent();
    }
    return this;
  }

  /*package*/ PseudocodeLabel createLabel(@NotNull String name, @Nullable String comment) {
    PseudocodeLabel label = new PseudocodeLabel(name, comment);
    labels.add(label);
    return label;
  }

  @Override
  @NotNull
  public List<Instruction> getInstructions() {
    return instructions;
  }

  @NotNull
  @Override
  public List<Instruction> getReversedInstructions() {
    LinkedHashSet<Instruction> traversedInstructions = Sets.newLinkedHashSet();
    PseudocodeTraverserKt.traverseFollowingInstructions(
        sinkInstruction, traversedInstructions, BACKWARD, null);
    if (traversedInstructions.size() < instructions.size()) {
      List<Instruction> simplyReversedInstructions = Lists.newArrayList(instructions);
      Collections.reverse(simplyReversedInstructions);
      for (Instruction instruction : simplyReversedInstructions) {
        if (!traversedInstructions.contains(instruction)) {
          PseudocodeTraverserKt.traverseFollowingInstructions(
              instruction, traversedInstructions, BACKWARD, null);
        }
      }
    }
    return Lists.newArrayList(traversedInstructions);
  }

  @Override
  @NotNull
  public List<Instruction> getInstructionsIncludingDeadCode() {
    return mutableInstructionList;
  }

  // for tests only
  @NotNull
  public List<PseudocodeLabel> getLabels() {
    return labels;
  }

  /*package*/ void addExitInstruction(SubroutineExitInstruction exitInstruction) {
    addInstruction(exitInstruction);
    assert this.exitInstruction == null;
    this.exitInstruction = exitInstruction;
  }

  /*package*/ void addSinkInstruction(SubroutineSinkInstruction sinkInstruction) {
    addInstruction(sinkInstruction);
    assert this.sinkInstruction == null;
    this.sinkInstruction = sinkInstruction;
  }

  /*package*/ void addErrorInstruction(SubroutineExitInstruction errorInstruction) {
    addInstruction(errorInstruction);
    assert this.errorInstruction == null;
    this.errorInstruction = errorInstruction;
  }

  /*package*/ void addInstruction(Instruction instruction) {
    mutableInstructionList.add(instruction);
    instruction.setOwner(this);

    if (instruction instanceof KtElementInstruction) {
      KtElementInstruction elementInstruction = (KtElementInstruction) instruction;
      representativeInstructions.put(elementInstruction.getElement(), instruction);
    }

    if (instruction instanceof MergeInstruction) {
      addMergedValues((MergeInstruction) instruction);
    }

    for (PseudoValue inputValue : instruction.getInputValues()) {
      addValueUsage(inputValue, instruction);
      for (PseudoValue mergedValue : getMergedValues(inputValue)) {
        addValueUsage(mergedValue, instruction);
      }
    }
    if (PseudocodeUtilsKt.calcSideEffectFree(instruction)) {
      sideEffectFree.add(instruction);
    }
  }

  @Override
  @NotNull
  public SubroutineExitInstruction getExitInstruction() {
    return exitInstruction;
  }

  @Override
  @NotNull
  public SubroutineSinkInstruction getSinkInstruction() {
    return sinkInstruction;
  }

  @Override
  @NotNull
  public SubroutineEnterInstruction getEnterInstruction() {
    return (SubroutineEnterInstruction) mutableInstructionList.get(0);
  }

  @Nullable
  @Override
  public PseudoValue getElementValue(@Nullable KtElement element) {
    return elementsToValues.get(element);
  }

  @NotNull
  @Override
  public List<? extends KtElement> getValueElements(@Nullable PseudoValue value) {
    List<? extends KtElement> result = elementsToValues.getKeysByValue(value);
    return result != null ? result : Collections.<KtElement>emptyList();
  }

  @NotNull
  @Override
  public List<? extends Instruction> getUsages(@Nullable PseudoValue value) {
    List<? extends Instruction> result = valueUsages.get(value);
    return result != null ? result : Collections.<Instruction>emptyList();
  }

  @Override
  public boolean isSideEffectFree(@NotNull Instruction instruction) {
    return sideEffectFree.contains(instruction);
  }

  /*package*/ void bindElementToValue(@NotNull KtElement element, @NotNull PseudoValue value) {
    elementsToValues.put(element, value);
  }

  /*package*/ void bindLabel(Label label) {
    ((PseudocodeLabel) label).setTargetInstructionIndex(mutableInstructionList.size());
  }

  private Set<PseudoValue> getMergedValues(@NotNull PseudoValue value) {
    Set<PseudoValue> result = mergedValues.get(value);
    return result != null ? result : Collections.<PseudoValue>emptySet();
  }

  private void addMergedValues(@NotNull MergeInstruction instruction) {
    Set<PseudoValue> result = new LinkedHashSet<PseudoValue>();
    for (PseudoValue value : instruction.getInputValues()) {
      result.addAll(getMergedValues(value));
      result.add(value);
    }
    mergedValues.put(instruction.getOutputValue(), result);
  }

  private void addValueUsage(PseudoValue value, Instruction usage) {
    if (usage instanceof MergeInstruction) return;
    MapsKt.getOrPut(
            valueUsages,
            value,
            new Function0<List<Instruction>>() {
              @Override
              public List<Instruction> invoke() {
                return Lists.newArrayList();
              }
            })
        .add(usage);
  }

  public void postProcess() {
    if (postPrecessed) return;
    postPrecessed = true;
    errorInstruction.setSink(getSinkInstruction());
    exitInstruction.setSink(getSinkInstruction());
    int index = 0;
    for (Instruction instruction : mutableInstructionList) {
      // recursively invokes 'postProcess' for local declarations
      processInstruction(instruction, index);
      index++;
    }
    if (getParent() != null) return;

    // Collecting reachable instructions should be done after processing all instructions
    // (including instructions in local declarations) to avoid being in incomplete state.
    collectAndCacheReachableInstructions();
    for (LocalFunctionDeclarationInstruction localFunctionDeclarationInstruction :
        getLocalDeclarations()) {
      ((PseudocodeImpl) localFunctionDeclarationInstruction.getBody())
          .collectAndCacheReachableInstructions();
    }
  }

  private void collectAndCacheReachableInstructions() {
    Set<Instruction> reachableInstructions = collectReachableInstructions();
    for (Instruction instruction : mutableInstructionList) {
      if (reachableInstructions.contains(instruction)) {
        instructions.add(instruction);
      }
    }
    markDeadInstructions();
  }

  private void processInstruction(Instruction instruction, final int currentPosition) {
    instruction.accept(
        new InstructionVisitor() {
          @Override
          public void visitInstructionWithNext(@NotNull InstructionWithNext instruction) {
            instruction.setNext(getNextPosition(currentPosition));
          }

          @Override
          public void visitJump(@NotNull AbstractJumpInstruction instruction) {
            instruction.setResolvedTarget(getJumpTarget(instruction.getTargetLabel()));
          }

          @Override
          public void visitNondeterministicJump(
              @NotNull NondeterministicJumpInstruction instruction) {
            instruction.setNext(getNextPosition(currentPosition));
            List<Label> targetLabels = instruction.getTargetLabels();
            for (Label targetLabel : targetLabels) {
              instruction.setResolvedTarget(targetLabel, getJumpTarget(targetLabel));
            }
          }

          @Override
          public void visitConditionalJump(@NotNull ConditionalJumpInstruction instruction) {
            Instruction nextInstruction = getNextPosition(currentPosition);
            Instruction jumpTarget = getJumpTarget(instruction.getTargetLabel());
            if (instruction.getOnTrue()) {
              instruction.setNextOnFalse(nextInstruction);
              instruction.setNextOnTrue(jumpTarget);
            } else {
              instruction.setNextOnFalse(jumpTarget);
              instruction.setNextOnTrue(nextInstruction);
            }
            visitJump(instruction);
          }

          @Override
          public void visitLocalFunctionDeclarationInstruction(
              @NotNull LocalFunctionDeclarationInstruction instruction) {
            PseudocodeImpl body = (PseudocodeImpl) instruction.getBody();
            body.setParent(PseudocodeImpl.this);
            body.postProcess();
            instruction.setNext(getSinkInstruction());
          }

          @Override
          public void visitSubroutineExit(@NotNull SubroutineExitInstruction instruction) {
            // Nothing
          }

          @Override
          public void visitSubroutineSink(@NotNull SubroutineSinkInstruction instruction) {
            // Nothing
          }

          @Override
          public void visitInstruction(@NotNull Instruction instruction) {
            throw new UnsupportedOperationException(instruction.toString());
          }
        });
  }

  private Set<Instruction> collectReachableInstructions() {
    Set<Instruction> visited = Sets.newHashSet();
    PseudocodeTraverserKt.traverseFollowingInstructions(
        getEnterInstruction(), visited, FORWARD, null);
    if (!visited.contains(getExitInstruction())) {
      visited.add(getExitInstruction());
    }
    if (!visited.contains(errorInstruction)) {
      visited.add(errorInstruction);
    }
    if (!visited.contains(getSinkInstruction())) {
      visited.add(getSinkInstruction());
    }
    return visited;
  }

  private void markDeadInstructions() {
    Set<Instruction> instructionSet = Sets.newHashSet(instructions);
    for (Instruction instruction : mutableInstructionList) {
      if (!instructionSet.contains(instruction)) {
        ((InstructionImpl) instruction).setMarkedAsDead(true);
        for (Instruction nextInstruction : instruction.getNextInstructions()) {
          nextInstruction.getPreviousInstructions().remove(instruction);
        }
      }
    }
  }

  @NotNull
  private Instruction getJumpTarget(@NotNull Label targetLabel) {
    return ((PseudocodeLabel) targetLabel).resolveToInstruction();
  }

  @NotNull
  private Instruction getNextPosition(int currentPosition) {
    int targetPosition = currentPosition + 1;
    assert targetPosition < mutableInstructionList.size() : currentPosition;
    return mutableInstructionList.get(targetPosition);
  }

  @Override
  public PseudocodeImpl copy() {
    PseudocodeImpl result = new PseudocodeImpl(correspondingElement);
    result.repeatWhole(this);
    return result;
  }

  private void repeatWhole(@NotNull PseudocodeImpl originalPseudocode) {
    repeatInternal(originalPseudocode, null, null, 0);
    parent = originalPseudocode.parent;
  }

  public int repeatPart(@NotNull Label startLabel, @NotNull Label finishLabel, int labelCount) {
    return repeatInternal(
        ((PseudocodeLabel) startLabel).getPseudocode(), startLabel, finishLabel, labelCount);
  }

  private int repeatInternal(
      @NotNull PseudocodeImpl originalPseudocode,
      @Nullable Label startLabel,
      @Nullable Label finishLabel,
      int labelCount) {
    Integer startIndex =
        startLabel != null
            ? ((PseudocodeLabel) startLabel).getTargetInstructionIndex()
            : Integer.valueOf(0);
    assert startIndex != null;
    Integer finishIndex =
        finishLabel != null
            ? ((PseudocodeLabel) finishLabel).getTargetInstructionIndex()
            : Integer.valueOf(originalPseudocode.mutableInstructionList.size());
    assert finishIndex != null;

    Map<Label, Label> originalToCopy = Maps.newLinkedHashMap();
    Multimap<Instruction, Label> originalLabelsForInstruction = HashMultimap.create();
    for (PseudocodeLabel label : originalPseudocode.labels) {
      Integer index = label.getTargetInstructionIndex();
      if (index == null) continue; // label is not bounded yet
      if (label == startLabel || label == finishLabel) continue;

      if (startIndex <= index && index <= finishIndex) {
        originalToCopy.put(label, label.copy(labelCount++));
        originalLabelsForInstruction.put(getJumpTarget(label), label);
      }
    }
    for (Label label : originalToCopy.values()) {
      labels.add((PseudocodeLabel) label);
    }
    for (int index = startIndex; index < finishIndex; index++) {
      Instruction originalInstruction = originalPseudocode.mutableInstructionList.get(index);
      repeatLabelsBindingForInstruction(
          originalInstruction, originalToCopy, originalLabelsForInstruction);
      Instruction copy = copyInstruction(originalInstruction, originalToCopy);
      addInstruction(copy);
      if (originalInstruction == originalPseudocode.errorInstruction
          && copy instanceof SubroutineExitInstruction) {
        errorInstruction = (SubroutineExitInstruction) copy;
      }
      if (originalInstruction == originalPseudocode.exitInstruction
          && copy instanceof SubroutineExitInstruction) {
        exitInstruction = (SubroutineExitInstruction) copy;
      }
      if (originalInstruction == originalPseudocode.sinkInstruction
          && copy instanceof SubroutineSinkInstruction) {
        sinkInstruction = (SubroutineSinkInstruction) copy;
      }
    }
    if (finishIndex < mutableInstructionList.size()) {
      repeatLabelsBindingForInstruction(
          originalPseudocode.mutableInstructionList.get(finishIndex),
          originalToCopy,
          originalLabelsForInstruction);
    }
    return labelCount;
  }

  private void repeatLabelsBindingForInstruction(
      @NotNull Instruction originalInstruction,
      @NotNull Map<Label, Label> originalToCopy,
      @NotNull Multimap<Instruction, Label> originalLabelsForInstruction) {
    for (Label originalLabel : originalLabelsForInstruction.get(originalInstruction)) {
      bindLabel(originalToCopy.get(originalLabel));
    }
  }

  private static Instruction copyInstruction(
      @NotNull Instruction instruction, @NotNull Map<Label, Label> originalToCopy) {
    if (instruction instanceof AbstractJumpInstruction) {
      Label originalTarget = ((AbstractJumpInstruction) instruction).getTargetLabel();
      if (originalToCopy.containsKey(originalTarget)) {
        return ((AbstractJumpInstruction) instruction).copy(originalToCopy.get(originalTarget));
      }
    }
    if (instruction instanceof NondeterministicJumpInstruction) {
      List<Label> originalTargets =
          ((NondeterministicJumpInstruction) instruction).getTargetLabels();
      List<Label> copyTargets = copyLabels(originalTargets, originalToCopy);
      return ((NondeterministicJumpInstruction) instruction).copy(copyTargets);
    }
    return ((InstructionImpl) instruction).copy();
  }

  @NotNull
  private static List<Label> copyLabels(
      Collection<Label> labels, Map<Label, Label> originalToCopy) {
    List<Label> newLabels = Lists.newArrayList();
    for (Label label : labels) {
      Label newLabel = originalToCopy.get(label);
      newLabels.add(newLabel != null ? newLabel : label);
    }
    return newLabels;
  }
}