content: /*
   * Copyright 2016 HuntBugs contributors
   * 
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *     http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package one.util.huntbugs.detect;
  
  import com.strobel.assembler.metadata.MethodReference;
  import com.strobel.assembler.metadata.TypeReference;
  import com.strobel.decompiler.ast.AstCode;
  import com.strobel.decompiler.ast.Expression;
  
  import one.util.huntbugs.registry.MethodContext;
  import one.util.huntbugs.registry.anno.AstNodes;
  import one.util.huntbugs.registry.anno.AstVisitor;
  import one.util.huntbugs.registry.anno.WarningDefinition;
  import one.util.huntbugs.util.Exprs;
  import one.util.huntbugs.util.Types;
  import one.util.huntbugs.warning.Roles;
  import one.util.huntbugs.warning.Role.TypeRole;
  
  /**
   * @author Tagir Valeev
   *
   */
  @WarningDefinition(category = "Correctness", name = "ImpossibleToArrayDowncast", maxScore = 65)
  public class ToArrayDowncast {
      private static final TypeRole TARGET_ELEMENT_TYPE = TypeRole.forName("TARGET_ELEMENT_TYPE");
  
      @AstVisitor(nodes = AstNodes.EXPRESSIONS)
      public void visit(Expression expr, MethodContext mc) {
          if (expr.getCode() != AstCode.CheckCast)
              return;
          TypeReference targetType = (TypeReference) expr.getOperand();
          if (!targetType.isArray() || Types.isObject(targetType.getElementType()))
              return;
          Expression arg = Exprs.getChild(expr, 0);
          if (arg.getCode() != AstCode.InvokeVirtual && arg.getCode() != AstCode.InvokeInterface)
              return;
          MethodReference mr = (MethodReference) arg.getOperand();
          if (!mr.getName().equals("toArray") || !mr.getSignature().equals("()[Ljava/lang/Object;"))
              return;
          Expression target = Exprs.getChild(arg, 0);
          if (!Types.isInstance(target.getInferredType(), "java/util/Collection"))
              return;
          mc.report("ImpossibleToArrayDowncast", 0, target, Roles.TARGET_TYPE.create(targetType),
              TARGET_ELEMENT_TYPE.create(targetType.getElementType()));
      }
  }
  