plugins/InspectionGadgets/src/com/siyeh/ig/bugs/MalformedRegexInspection.java

   1 /*
   2  * Copyright 2003-2007 Dave Griffith, Bas Leijdekkers
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package com.siyeh.ig.bugs;
  17
  18 import com.intellij.psi.PsiExpression;
  19 import com.intellij.psi.PsiExpressionList;
  20 import com.intellij.psi.PsiMethodCallExpression;
  21 import com.intellij.psi.PsiType;
  22 import com.intellij.psi.util.ConstantExpressionUtil;
  23 import com.intellij.psi.util.PsiUtil;
  24 import com.siyeh.InspectionGadgetsBundle;
  25 import com.siyeh.ig.BaseInspection;
  26 import com.siyeh.ig.BaseInspectionVisitor;
  27 import com.siyeh.ig.psiutils.MethodCallUtils;
  28 import com.siyeh.ig.psiutils.TypeUtils;
  29 import org.jetbrains.annotations.NotNull;
  30
  31 import java.util.regex.Pattern;
  32 import java.util.regex.PatternSyntaxException;
  33
  34 public class MalformedRegexInspection extends BaseInspection {
  35
  36     @NotNull
  37     public String getDisplayName(){
  38         return InspectionGadgetsBundle.message(
  39                 "malformed.regular.expression.display.name");
  40     }
  41
  42     @NotNull
  43     public String buildErrorString(Object... infos){
  44         if (infos.length == 0) {
  45             return InspectionGadgetsBundle.message(
  46                     "malformed.regular.expression.problem.descriptor1");
  47         } else {
  48             return InspectionGadgetsBundle.message(
  49                     "malformed.regular.expression.problem.descriptor2",
  50                     infos[0]);
  51         }
  52     }
  53
  54     public boolean isEnabledByDefault(){
  55         return true;
  56     }
  57
  58     public BaseInspectionVisitor buildVisitor(){
  59         return new MalformedRegexVisitor();
  60     }
  61
  62     private static class MalformedRegexVisitor extends BaseInspectionVisitor{
  63
  64         @Override public void visitMethodCallExpression(
  65                 @NotNull PsiMethodCallExpression expression){
  66             super.visitMethodCallExpression(expression);
  67             final PsiExpressionList argList = expression.getArgumentList();
  68             if(argList == null){
  69                 return;
  70             }
  71             final PsiExpression[] args = argList.getExpressions();
  72             if(args.length == 0){
  73                 return;
  74             }
  75             final PsiExpression regexArg = args[0];
  76             if(!TypeUtils.expressionHasType("java.lang.String", regexArg)){
  77                 return;
  78             }
  79             if(!PsiUtil.isConstantExpression(regexArg)){
  80                 return;
  81             }
  82             final PsiType regexType = regexArg.getType();
  83             final String value =
  84                     (String) ConstantExpressionUtil.computeCastTo(regexArg,
  85                             regexType);
  86             if(value == null){
  87                 return;
  88             }
  89             if(!MethodCallUtils.isCallToRegexMethod(expression)){
  90                 return;
  91             }
  92             //noinspection UnusedCatchParameter,ProhibitedExceptionCaught
  93             try{
  94                 Pattern.compile(value);
  95             } catch(PatternSyntaxException e){
  96                 registerError(regexArg, e.getDescription());
  97             } catch(NullPointerException e){
  98                 registerError(regexArg); // due to a bug in the sun regex code
  99             }
 100         }
 101     }
 102 }