예제 #1
0
 /*
  * @see com.ibm.wala.cfg.ControlFlowGraph#getProgramCounter(int)
  */
 public int getProgramCounter(int index) {
   try {
     return method.getBytecodeIndex(index);
   } catch (InvalidClassFileException e) {
     e.printStackTrace();
     Assertions.UNREACHABLE();
     return -1;
   }
 }
예제 #2
0
 public IInstruction[] getInstructions() {
   try {
     return method.getInstructions();
   } catch (InvalidClassFileException e) {
     e.printStackTrace();
     Assertions.UNREACHABLE();
     return null;
   }
 }
예제 #3
0
 /*
  * @see com.ibm.wala.classLoader.IClass#getDeclaredMethods()
  */
 @Override
 public Collection<IMethod> getDeclaredMethods() {
   try {
     computeMethodMapIfNeeded();
   } catch (InvalidClassFileException e) {
     e.printStackTrace();
     Assertions.UNREACHABLE();
   }
   return Collections.unmodifiableCollection(methodMap.values());
 }
예제 #4
0
 private ExceptionHandler[] getExceptionHandlers() {
   ExceptionHandler[][] handlers;
   try {
     handlers = method.getHandlers();
   } catch (InvalidClassFileException e) {
     e.printStackTrace();
     Assertions.UNREACHABLE();
     handlers = null;
   }
   ExceptionHandler[] hs = handlers[getLastInstructionIndex()];
   return hs;
 }
예제 #5
0
  /*
   * @see com.ibm.wala.classLoader.IClass#getMethod(com.ibm.wala.types.Selector)
   */
  @Override
  public IMethod getMethod(Selector selector) {
    try {
      computeMethodMapIfNeeded();
    } catch (InvalidClassFileException e1) {
      e1.printStackTrace();
      Assertions.UNREACHABLE();
    }

    // my methods + cached parent stuff
    IMethod result = methodMap.get(selector);
    if (result != null) {
      return result;
    }
    if (inheritCache != null) {
      result = inheritCache.get(selector);
      if (result != null) {
        return result;
      }
    }

    // check parent, caching if found
    if (!selector.equals(MethodReference.clinitSelector)
        && !selector.equals(MethodReference.initSelector)) {
      IClass superclass = getSuperclass();
      if (superclass != null) {
        IMethod inherit = superclass.getMethod(selector);
        if (inherit != null) {
          if (inheritCache == null) {
            inheritCache = new BimodalMap<Selector, IMethod>(5);
          }
          inheritCache.put(selector, inherit);
          return inherit;
        }
      }
    }

    // didn't find it yet. special logic for interfaces
    if (isInterface() || isAbstract()) {
      final Iterator<IClass> it = getAllImplementedInterfaces().iterator();
      // try each superinterface
      while (it.hasNext()) {
        IClass k = it.next();
        result = k.getMethod(selector);
        if (result != null) {
          return result;
        }
      }
    }
    return null;
  }
예제 #6
0
    /**
     * Add any exceptional edges generated by the last instruction in a basic block.
     *
     * @param last the last instruction in a basic block.
     */
    protected void addExceptionalEdges(IInstruction last) {
      IClassHierarchy cha = getMethod().getClassHierarchy();
      if (last.isPEI()) {
        Collection<TypeReference> exceptionTypes = null;
        boolean goToAllHandlers = false;

        ExceptionHandler[] hs = getExceptionHandlers();
        if (last instanceof ThrowInstruction) {
          // this class does not have the type information needed
          // to determine what the athrow throws. So, add an
          // edge to all reachable handlers. Better information can
          // be obtained later with SSA type propagation.
          // TODO: consider pruning to only the exception types that
          // this method either catches or allocates, since these are
          // the only types that can flow to an athrow.
          goToAllHandlers = true;
        } else {
          if (hs != null && hs.length > 0) {
            IClassLoader loader = getMethod().getDeclaringClass().getClassLoader();
            BytecodeLanguage l = (BytecodeLanguage) loader.getLanguage();
            exceptionTypes = l.getImplicitExceptionTypes(last);
            if (last instanceof IInvokeInstruction) {
              IInvokeInstruction call = (IInvokeInstruction) last;
              exceptionTypes = HashSetFactory.make(exceptionTypes);
              MethodReference target =
                  MethodReference.findOrCreate(
                      l,
                      loader.getReference(),
                      call.getClassType(),
                      call.getMethodName(),
                      call.getMethodSignature());
              try {
                exceptionTypes.addAll(l.inferInvokeExceptions(target, cha));
              } catch (InvalidClassFileException e) {
                e.printStackTrace();
                Assertions.UNREACHABLE();
              }
            }
          }
        }

        if (hs != null && hs.length > 0) {
          // found a handler for this PEI

          // create a mutable copy
          if (!goToAllHandlers) {
            exceptionTypes = HashSetFactory.make(exceptionTypes);
          }

          // this var gets set to false if goToAllHandlers is true but some enclosing exception
          // handler catches all
          // exceptions.  in such a case, we need not add an exceptional edge to the method exit
          boolean needEdgeToExitForAllHandlers = true;
          for (int j = 0; j < hs.length; j++) {
            if (DEBUG) {
              System.err.println(" handler " + hs[j]);
            }
            BasicBlock b = getBlockForInstruction(hs[j].getHandler());
            if (DEBUG) {
              System.err.println(" target " + b);
            }
            if (goToAllHandlers) {
              // add an edge to the catch block.
              if (DEBUG) {
                System.err.println(" gotoAllHandlers " + b);
              }
              addExceptionalEdgeTo(b);
              // if the handler catches all exceptions, we don't need to add an edge to the exit or
              // any other handlers
              if (hs[j].getCatchClass() == null) {
                needEdgeToExitForAllHandlers = false;
                break;
              }
            } else {
              TypeReference caughtException = null;
              if (hs[j].getCatchClass() != null) {
                ClassLoaderReference loader =
                    ShrikeCFG.this.getMethod().getDeclaringClass().getReference().getClassLoader();
                caughtException = ShrikeUtil.makeTypeReference(loader, hs[j].getCatchClass());
                if (DEBUG) {
                  System.err.println(" caughtException " + caughtException);
                }
                IClass caughtClass = cha.lookupClass(caughtException);
                if (caughtClass == null) {
                  // conservatively add the edge, and raise a warning
                  addExceptionalEdgeTo(b);
                  Warnings.add(FailedExceptionResolutionWarning.create(caughtException));
                  // null out caughtException, to avoid attempting to process it
                  caughtException = null;
                }
              } else {
                if (DEBUG) {
                  System.err.println(" catchClass() == null");
                }
                // hs[j].getCatchClass() == null.
                // this means that the handler catches all exceptions.
                // add the edge and null out all types
                if (!exceptionTypes.isEmpty()) {
                  addExceptionalEdgeTo(b);
                  exceptionTypes.clear();
                  caughtException = null;
                }
              }
              if (caughtException != null) {
                IClass caughtClass = cha.lookupClass(caughtException);
                // the set "caught" should be the set of exceptions that MUST
                // have been caught by the handlers in scope
                ArrayList<TypeReference> caught =
                    new ArrayList<TypeReference>(exceptionTypes.size());
                // check if we should add an edge to the catch block.
                for (TypeReference t : exceptionTypes) {
                  if (t != null) {
                    IClass klass = cha.lookupClass(t);
                    if (klass == null) {
                      Warnings.add(FailedExceptionResolutionWarning.create(caughtException));
                      // conservatively add an edge
                      addExceptionalEdgeTo(b);
                    } else {
                      boolean subtype1 = cha.isSubclassOf(klass, caughtClass);
                      if (subtype1 || cha.isSubclassOf(caughtClass, klass)) {
                        // add the edge and null out the type from the array
                        addExceptionalEdgeTo(b);
                        if (subtype1) {
                          caught.add(t);
                        }
                      }
                    }
                  }
                }
                exceptionTypes.removeAll(caught);
              }
            }
          }
          // if needed, add an edge to the exit block.
          if ((exceptionTypes == null && needEdgeToExitForAllHandlers)
              || (exceptionTypes != null && !exceptionTypes.isEmpty())) {
            BasicBlock exit = exit();
            addExceptionalEdgeTo(exit);
          }
        } else {
          // found no handler for this PEI ... link to the exit block.
          BasicBlock exit = exit();
          addExceptionalEdgeTo(exit);
        }
      }
    }
예제 #7
0
  private void makeBasicBlocks() {
    ExceptionHandler[][] handlers;
    try {
      handlers = method.getHandlers();
    } catch (InvalidClassFileException e) {
      e.printStackTrace();
      Assertions.UNREACHABLE();
      handlers = null;
    }
    boolean[] r = new boolean[getInstructions().length];
    boolean[] catchers = new boolean[getInstructions().length];
    // we initially start with both the entry and exit block.
    int blockCount = 2;

    // Compute r so r[i] == true iff instruction i begins a basic block.
    // While doing so count the number of blocks.
    r[0] = true;
    IInstruction[] instructions = getInstructions();
    for (int i = 0; i < instructions.length; i++) {
      int[] targets = instructions[i].getBranchTargets();

      // if there are any targets, then break the basic block here.
      // also break the basic block after a return
      if (targets.length > 0 || !instructions[i].isFallThrough()) {
        if (i + 1 < instructions.length && !r[i + 1]) {
          r[i + 1] = true;
          blockCount++;
        }
      }

      for (int j = 0; j < targets.length; j++) {
        if (!r[targets[j]]) {
          r[targets[j]] = true;
          blockCount++;
        }
      }
      if (instructions[i].isPEI()) {
        ExceptionHandler[] hs = handlers[i];
        // break the basic block here.
        if (i + 1 < instructions.length && !r[i + 1]) {
          r[i + 1] = true;
          blockCount++;
        }
        if (hs != null && hs.length > 0) {
          for (int j = 0; j < hs.length; j++) {
            exceptionHandlers.add(hs[j]);
            if (!r[hs[j].getHandler()]) {
              // we have not discovered the catch block yet.
              // form a new basic block
              r[hs[j].getHandler()] = true;
              blockCount++;
            }
            catchers[hs[j].getHandler()] = true;
          }
        }
      }
    }

    BasicBlock entry = new BasicBlock(-1);
    addNode(entry);

    int j = 1;
    for (int i = 0; i < r.length; i++) {
      if (r[i]) {
        BasicBlock b = new BasicBlock(i);
        addNode(b);
        if (catchers[i]) {
          setCatchBlock(j);
        }
        j++;
      }
    }

    BasicBlock exit = new BasicBlock(-1);
    addNode(exit);
  }