org.sonar.java.checks.regex.CanonEqFlagInRegexCheck Maven / Gradle / Ivy

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/*
 * SonarQube Java
 * Copyright (C) 2012-2024 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the Sonar Source-Available License Version 1, as published by SonarSource SA.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the Sonar Source-Available License for more details.
 *
 * You should have received a copy of the Sonar Source-Available License
 * along with this program; if not, see https://sonarsource.com/license/ssal/
 */
package org.sonar.java.checks.regex;

import java.text.Normalizer;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
import org.sonar.check.Rule;
import org.sonar.plugins.java.api.semantic.MethodMatchers;
import org.sonar.plugins.java.api.tree.ExpressionTree;
import org.sonar.plugins.java.api.tree.MethodInvocationTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonarsource.analyzer.commons.regex.RegexParseResult;
import org.sonarsource.analyzer.commons.regex.ast.CharacterClassTree;
import org.sonarsource.analyzer.commons.regex.ast.CharacterTree;
import org.sonarsource.analyzer.commons.regex.ast.RegexBaseVisitor;
import org.sonarsource.analyzer.commons.regex.ast.SequenceTree;

import static org.sonarsource.analyzer.commons.regex.helpers.GraphemeHelper.getGraphemeInList;

@Rule(key = "S5854")
public class CanonEqFlagInRegexCheck extends AbstractRegexCheck {

  protected static final MethodMatchers STRING_MATCHES = MethodMatchers.create()
    .ofTypes(JAVA_LANG_STRING)
    .names("matches")
    .addParametersMatcher(JAVA_LANG_STRING)
    .build();

  protected static final MethodMatchers STRING_REPLACE_ALL = MethodMatchers.create()
    .ofTypes(JAVA_LANG_STRING)
    .names("replaceAll")
    .addParametersMatcher(JAVA_LANG_STRING, JAVA_LANG_STRING)
    .build();

  protected static final MethodMatchers STRING_REPLACE_FIRST = MethodMatchers.create()
    .ofTypes(JAVA_LANG_STRING)
    .names("replaceFirst")
    .addParametersMatcher(JAVA_LANG_STRING, JAVA_LANG_STRING)
    .build();

  protected static final MethodMatchers PATTERN_MATCHES = MethodMatchers.create()
    .ofTypes("java.util.regex.Pattern")
    .names("matches")
    .addParametersMatcher(JAVA_LANG_STRING, "java.lang.CharSequence")
    .build();

  @Override
  public void checkRegex(RegexParseResult regexForLiterals, ExpressionTree methodInvocationOrAnnotation) {
    if (regexForLiterals.getInitialFlags().contains(Pattern.CANON_EQ)) {
      return;
    }
    CharacterVisitor visitor = new CharacterVisitor();
    visitor.visit(regexForLiterals);

    if (!visitor.subjectToNormalization.isEmpty()) {
      String endOfMessage = "this pattern";
      if (methodInvocationOrAnnotation.is(Tree.Kind.METHOD_INVOCATION)) {
        MethodInvocationTree mit = (MethodInvocationTree) methodInvocationOrAnnotation;
        if (STRING_MATCHES.matches(mit) || PATTERN_MATCHES.matches(mit)) {
          endOfMessage = "\"Pattern.compile(regex, CANON_EQ).matcher(input).matches()\"";
        } else if (STRING_REPLACE_ALL.matches(mit)) {
          endOfMessage = "\"Pattern.compile(pattern, CANON_EQ).matcher(input).replaceAll(replacement)\"";
        } else if (STRING_REPLACE_FIRST.matches(mit)) {
          endOfMessage = "\"Pattern.compile(pattern, CANON_EQ).matcher(input).replaceFirst(replacement)\"";
        }
      }
      reportIssue(regexForLiterals.getResult(), String.format("Use the CANON_EQ flag with %s.", endOfMessage), null, visitor.subjectToNormalization);
    }
  }

  private static class CharacterVisitor extends RegexBaseVisitor {

    private final List subjectToNormalization = new ArrayList<>();

    @Override
    public void visitSequence(SequenceTree tree) {
      getGraphemeInList(tree.getItems())
        .stream()
        .map(RegexIssueLocation::fromCommonsRegexIssueLocation)
        .forEach(subjectToNormalization::add);
      super.visitSequence(tree);
    }

    @Override
    public void visitCharacterClass(CharacterClassTree tree) {
      // Stop visit in classes, S5868 will report an eventual issue for it.
    }

    @Override
    public void visitCharacter(CharacterTree tree) {
      String str = tree.characterAsString();
      if (isSubjectToNormalization(str)) {
        subjectToNormalization.add(new RegexIssueLocation(tree, ""));
      }
    }

    private static boolean isSubjectToNormalization(String str) {
      return !Normalizer.isNormalized(str, Normalizer.Form.NFD);
    }

  }

}