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The first Static Analysis and REMEDIATION tool

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/*
 * Copyright 2024 the original author or authors.
 * 
 * Licensed under the Moderne Source Available License (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 

 * https://docs.moderne.io/licensing/moderne-source-available-license
 * 
 * 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 org.openrewrite.staticanalysis;

import org.openrewrite.ExecutionContext;
import org.openrewrite.java.JavaVisitor;
import org.openrewrite.java.tree.J;
import org.openrewrite.java.tree.Statement;

import java.util.List;
import java.util.Optional;

class RemoveUnreachableCodeVisitor extends JavaVisitor {

  @Override
  public J visitBlock(J.Block block, ExecutionContext executionContext) {
    block = (J.Block) super.visitBlock(block, executionContext);

    List statements = block.getStatements();
    Optional maybeFirstJumpIndex = findFirstJump(statements);
    if (!maybeFirstJumpIndex.isPresent()) {
      return block;
    }
    int firstJumpIndex = maybeFirstJumpIndex.get();

    if (firstJumpIndex == statements.size() - 1) {
      // Jump is at the end of the block, so nothing to do
      return block;
    }

    List newStatements = statements.subList(0, firstJumpIndex + 1);
    return block.withStatements(newStatements);
  }

  private Optional findFirstJump(List statements) {
    for (int i = 0; i < statements.size(); i++) {
      Statement statement = statements.get(i);
      if (
          statement instanceof J.Return ||
          statement instanceof J.Throw ||
          statement instanceof J.Break ||
          statement instanceof J.Continue
      ) {
        return Optional.of(i);
      }
    }
    return Optional.empty();
  }
}