| /* |
| * Copyright 2000-2013 JetBrains s.r.o. |
| * |
| * 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 com.jetbrains.python.inspections; |
| |
| import com.intellij.codeInsight.controlflow.ControlFlow; |
| import com.intellij.codeInsight.controlflow.ControlFlowUtil; |
| import com.intellij.codeInsight.controlflow.Instruction; |
| import com.intellij.codeInspection.LocalInspectionToolSession; |
| import com.intellij.codeInspection.ProblemsHolder; |
| import com.intellij.openapi.util.Ref; |
| import com.intellij.psi.PsiElement; |
| import com.intellij.psi.PsiElementVisitor; |
| import com.intellij.util.Function; |
| import com.jetbrains.python.PyBundle; |
| import com.jetbrains.python.codeInsight.controlflow.ControlFlowCache; |
| import com.jetbrains.python.codeInsight.controlflow.ScopeOwner; |
| import com.jetbrains.python.codeInsight.dataflow.scope.ScopeUtil; |
| import org.jetbrains.annotations.Nls; |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Detects unreachable code using control flow graph |
| */ |
| public class PyUnreachableCodeInspection extends PyInspection { |
| @Nls |
| @NotNull |
| public String getDisplayName() { |
| return PyBundle.message("INSP.NAME.unreachable.code"); |
| } |
| |
| @NotNull |
| @Override |
| public PsiElementVisitor buildVisitor(@NotNull final ProblemsHolder holder, |
| boolean isOnTheFly, |
| @NotNull LocalInspectionToolSession session) { |
| return new Visitor(holder, session); |
| } |
| |
| public static class Visitor extends PyInspectionVisitor { |
| public Visitor(@NotNull ProblemsHolder holder, @NotNull LocalInspectionToolSession session) { |
| super(holder, session); |
| } |
| |
| @Override |
| public void visitElement(final PsiElement element) { |
| if (element instanceof ScopeOwner) { |
| final ControlFlow flow = ControlFlowCache.getControlFlow((ScopeOwner)element); |
| final Instruction[] instructions = flow.getInstructions(); |
| final List<PsiElement> unreachable = new ArrayList<PsiElement>(); |
| if (instructions.length > 0) { |
| ControlFlowUtil.iteratePrev(instructions.length - 1, instructions, new Function<Instruction, ControlFlowUtil.Operation>() { |
| @Override |
| public ControlFlowUtil.Operation fun(Instruction instruction) { |
| if (instruction.allPred().isEmpty() && !isFirstInstruction(instruction)) { |
| unreachable.add(instruction.getElement()); |
| } |
| return ControlFlowUtil.Operation.NEXT; |
| } |
| }); |
| } |
| for (PsiElement e : unreachable) { |
| registerProblem(e, PyBundle.message("INSP.unreachable.code")); |
| } |
| } |
| } |
| } |
| |
| public static boolean hasAnyInterruptedControlFlowPaths(@NotNull PsiElement element) { |
| final ScopeOwner owner = ScopeUtil.getScopeOwner(element); |
| if (owner != null) { |
| final ControlFlow flow = ControlFlowCache.getControlFlow(owner); |
| final Instruction[] instructions = flow.getInstructions(); |
| final int start = ControlFlowUtil.findInstructionNumberByElement(instructions, element); |
| if (start >= 0) { |
| final Ref<Boolean> resultRef = Ref.create(false); |
| ControlFlowUtil.iteratePrev(start, instructions, new Function<Instruction, ControlFlowUtil.Operation>() { |
| @Override |
| public ControlFlowUtil.Operation fun(Instruction instruction) { |
| if (instruction.allPred().isEmpty() && !isFirstInstruction(instruction)) { |
| resultRef.set(true); |
| return ControlFlowUtil.Operation.BREAK; |
| } |
| return ControlFlowUtil.Operation.NEXT; |
| } |
| }); |
| return resultRef.get(); |
| } |
| } |
| return false; |
| } |
| |
| private static boolean isFirstInstruction(Instruction instruction) { |
| return instruction.num() == 0; |
| } |
| } |