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.FieldReference;
  import com.strobel.assembler.metadata.MethodDefinition;
  import com.strobel.assembler.metadata.MethodReference;
  import com.strobel.assembler.metadata.TypeDefinition;
  import com.strobel.decompiler.ast.AstCode;
  import com.strobel.decompiler.ast.Expression;
  import com.strobel.decompiler.ast.Node;
  import com.strobel.decompiler.ast.TryCatchBlock;
  
  import one.util.huntbugs.db.Hierarchy.TypeHierarchy;
  import one.util.huntbugs.registry.MethodContext;
  import one.util.huntbugs.registry.anno.AstVisitor;
  import one.util.huntbugs.registry.anno.MethodVisitor;
  import one.util.huntbugs.registry.anno.WarningDefinition;
  import one.util.huntbugs.util.Exprs;
  import one.util.huntbugs.util.Methods;
  import one.util.huntbugs.util.Nodes;
  
  /**
   * @author Tagir Valeev
   *
   */
  @WarningDefinition(category="Multithreading", name="SyncOnGetClass", maxScore=65)
  public class SyncGetClass {
      @MethodVisitor
      public boolean checkMethod(MethodDefinition md, TypeDefinition td) {
          return !td.isFinal() && !md.isStatic();
      }
      
      @AstVisitor
      public void visit(Node node, MethodContext mc, TypeHierarchy th, TypeDefinition td) {
          if(node instanceof TryCatchBlock) {
              Expression syncObject = Nodes.getSyncObject((TryCatchBlock) node);
              if(syncObject != null) {
                  if(syncObject.getCode() == AstCode.InvokeVirtual && Methods.isGetClass((MethodReference) syncObject.getOperand())
                          && Exprs.isThis(Exprs.getChild(syncObject, 0))) {
                      int priority = 0;
                      if(th != null && !th.hasSubClasses())
                          priority += 10;
                      if(Nodes.find(node, n -> isStaticFieldAccess(n, td)) == null)
                          priority += 15;
                      mc.report("SyncOnGetClass", priority, syncObject);
                  }
              }
          }
      }
  
      private boolean isStaticFieldAccess(Node n, TypeDefinition td) {
          if(!Nodes.isOp(n, AstCode.GetStatic) && !Nodes.isOp(n, AstCode.PutStatic))
              return false;
          FieldReference fr = (FieldReference)((Expression)n).getOperand();
          return fr.getDeclaringType().isEquivalentTo(td);
      }
  }
  