| /* |
| * 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.codeInsight.codeFragment; |
| |
| import com.intellij.codeInsight.codeFragment.CannotCreateCodeFragmentException; |
| import com.intellij.codeInsight.codeFragment.CodeFragmentUtil; |
| import com.intellij.codeInsight.codeFragment.Position; |
| import com.intellij.codeInsight.controlflow.ControlFlow; |
| import com.intellij.codeInsight.controlflow.Instruction; |
| import com.intellij.openapi.util.Pair; |
| import com.intellij.psi.*; |
| import com.intellij.psi.util.PsiTreeUtil; |
| import com.jetbrains.python.PyBundle; |
| import com.jetbrains.python.codeInsight.controlflow.ControlFlowCache; |
| import com.jetbrains.python.codeInsight.controlflow.ReadWriteInstruction; |
| import com.jetbrains.python.codeInsight.controlflow.ScopeOwner; |
| import com.jetbrains.python.codeInsight.dataflow.scope.Scope; |
| import com.jetbrains.python.codeInsight.dataflow.scope.ScopeUtil; |
| import com.jetbrains.python.psi.*; |
| import com.jetbrains.python.psi.impl.PyForStatementNavigator; |
| import com.jetbrains.python.psi.impl.PyPsiUtils; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| import java.util.*; |
| |
| /** |
| * @author oleg |
| */ |
| public class PyCodeFragmentUtil { |
| private PyCodeFragmentUtil() { |
| } |
| |
| @NotNull |
| public static PyCodeFragment createCodeFragment(@NotNull final ScopeOwner owner, |
| @NotNull final PsiElement startInScope, |
| @NotNull final PsiElement endInScope) throws CannotCreateCodeFragmentException { |
| final int start = startInScope.getTextOffset(); |
| final int end = endInScope.getTextOffset() + endInScope.getTextLength(); |
| final ControlFlow flow = ControlFlowCache.getControlFlow(owner); |
| if (flow == null) { |
| throw new CannotCreateCodeFragmentException("Cannot determine execution flow for the code fragment"); |
| } |
| final List<Instruction> graph = Arrays.asList(flow.getInstructions()); |
| final List<Instruction> subGraph = getFragmentSubGraph(graph, start, end); |
| final AnalysisResult subGraphAnalysis = analyseSubGraph(subGraph, start, end); |
| if ((subGraphAnalysis.regularExits > 0 && subGraphAnalysis.returns > 0) || |
| subGraphAnalysis.targetInstructions > 1 || |
| subGraphAnalysis.outerLoopBreaks > 0) { |
| throw new CannotCreateCodeFragmentException( |
| PyBundle.message("refactoring.extract.method.error.cannot.perform.refactoring.when.execution.flow.is.interrupted")); |
| } |
| if (subGraphAnalysis.starImports > 0) { |
| throw new CannotCreateCodeFragmentException( |
| PyBundle.message("refactoring.extract.method.error.cannot.perform.refactoring.when.from.import.inside")); |
| } |
| |
| final Set<String> globalWrites = getGlobalWrites(subGraph, owner); |
| final Set<String> nonlocalWrites = getNonlocalWrites(subGraph, owner); |
| |
| final Set<String> inputNames = new HashSet<String>(); |
| for (PsiElement element : filterElementsInScope(getInputElements(subGraph, graph), owner)) { |
| final String name = getName(element); |
| if (name != null) { |
| // Ignore "self" and "cls", they are generated automatically when extracting any method fragment |
| if (resolvesToBoundMethodParameter(element)) { |
| continue; |
| } |
| if (globalWrites.contains(name) || nonlocalWrites.contains(name)) { |
| continue; |
| } |
| inputNames.add(name); |
| } |
| } |
| |
| final Set<String> outputNames = new HashSet<String>(); |
| for (PsiElement element : getOutputElements(subGraph, graph)) { |
| final String name = getName(element); |
| if (name != null) { |
| if (globalWrites.contains(name) || nonlocalWrites.contains(name)) { |
| continue; |
| } |
| outputNames.add(name); |
| } |
| } |
| |
| |
| final boolean yieldsFound = subGraphAnalysis.yieldExpressions > 0; |
| if (yieldsFound && LanguageLevel.forElement(owner).isOlderThan(LanguageLevel.PYTHON33)) { |
| throw new CannotCreateCodeFragmentException("Cannot perform refactoring with 'yield' statement inside code block"); |
| } |
| |
| return new PyCodeFragment(inputNames, outputNames, globalWrites, nonlocalWrites, subGraphAnalysis.returns > 0, yieldsFound); |
| } |
| |
| private static boolean resolvesToBoundMethodParameter(@NotNull PsiElement element) { |
| if (PyPsiUtils.isMethodContext(element)) { |
| final PyFunction function = PsiTreeUtil.getParentOfType(element, PyFunction.class); |
| if (function != null) { |
| final PsiReference reference = element.getReference(); |
| if (reference != null) { |
| final PsiElement resolved = reference.resolve(); |
| if (resolved instanceof PyParameter) { |
| final PyParameterList parameterList = PsiTreeUtil.getParentOfType(resolved, PyParameterList.class); |
| if (parameterList != null) { |
| final PyParameter[] parameters = parameterList.getParameters(); |
| if (parameters.length > 0) { |
| if (resolved == parameters[0]) { |
| final PyFunction.Modifier modifier = function.getModifier(); |
| if (modifier == null || modifier == PyFunction.Modifier.CLASSMETHOD) { |
| return true; |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| return false; |
| } |
| |
| @Nullable |
| private static String getName(@NotNull PsiElement element) { |
| if (element instanceof PsiNamedElement) { |
| return ((PsiNamedElement)element).getName(); |
| } |
| else if (element instanceof PyImportElement) { |
| return ((PyImportElement)element).getVisibleName(); |
| } |
| else if (element instanceof PyElement) { |
| return ((PyElement)element).getName(); |
| } |
| return null; |
| } |
| |
| @NotNull |
| private static List<Instruction> getFragmentSubGraph(@NotNull List<Instruction> graph, int start, int end) { |
| List<Instruction> instructions = new ArrayList<Instruction>(); |
| for (Instruction instruction : graph) { |
| final PsiElement element = instruction.getElement(); |
| if (element != null) { |
| if (CodeFragmentUtil.getPosition(element, start, end) == Position.INSIDE) { |
| instructions.add(instruction); |
| } |
| } |
| } |
| // Hack for including inner assert type instructions that can point to elements outside of the selected scope |
| for (Instruction instruction : graph) { |
| if (instruction instanceof ReadWriteInstruction) { |
| final ReadWriteInstruction readWriteInstruction = (ReadWriteInstruction)instruction; |
| if (readWriteInstruction.getAccess().isAssertTypeAccess()) { |
| boolean innerAssertType = true; |
| for (Instruction next : readWriteInstruction.allSucc()) { |
| if (!instructions.contains(next)) { |
| innerAssertType = false; |
| break; |
| } |
| } |
| if (innerAssertType && !instructions.contains(instruction)) { |
| instructions.add(instruction); |
| } |
| } |
| } |
| } |
| return instructions; |
| } |
| |
| private static class AnalysisResult { |
| private final int starImports; |
| private final int targetInstructions; |
| private final int regularExits; |
| private final int returns; |
| private final int outerLoopBreaks; |
| private final int yieldExpressions; |
| |
| public AnalysisResult(int starImports, int targetInstructions, int returns, int regularExits, int outerLoopBreaks, int yieldExpressions) { |
| this.starImports = starImports; |
| this.targetInstructions = targetInstructions; |
| this.regularExits = regularExits; |
| this.returns = returns; |
| this.outerLoopBreaks = outerLoopBreaks; |
| this.yieldExpressions = yieldExpressions; |
| } |
| } |
| |
| @NotNull |
| private static AnalysisResult analyseSubGraph(@NotNull List<Instruction> subGraph, int start, int end) { |
| int returnSources = 0; |
| int regularSources = 0; |
| final Set<Instruction> targetInstructions = new HashSet<Instruction>(); |
| int starImports = 0; |
| int outerLoopBreaks = 0; |
| int yieldExpressions = 0; |
| |
| for (Pair<Instruction, Instruction> edge : getOutgoingEdges(subGraph)) { |
| final Instruction sourceInstruction = edge.getFirst(); |
| final Instruction targetInstruction = edge.getSecond(); |
| final PsiElement source = sourceInstruction.getElement(); |
| final PsiElement target = targetInstruction.getElement(); |
| |
| final PyReturnStatement returnStatement = PsiTreeUtil.getParentOfType(source, PyReturnStatement.class, false); |
| final boolean isExceptTarget = target instanceof PyExceptPart || target instanceof PyFinallyPart; |
| final boolean isLoopTarget = target instanceof PyWhileStatement || PyForStatementNavigator.getPyForStatementByIterable(target) != null; |
| |
| if (target != null && !isExceptTarget && !isLoopTarget) { |
| targetInstructions.add(targetInstruction); |
| } |
| |
| if (returnStatement != null && CodeFragmentUtil.getPosition(returnStatement, start, end) == Position.INSIDE) { |
| returnSources++; |
| } |
| else if (!isExceptTarget) { |
| regularSources++; |
| } |
| } |
| |
| final Set<PsiElement> subGraphElements = getSubGraphElements(subGraph); |
| for (PsiElement element : subGraphElements) { |
| if (element instanceof PyFromImportStatement) { |
| final PyFromImportStatement fromImportStatement = (PyFromImportStatement)element; |
| if (fromImportStatement.getStarImportElement() != null) { |
| starImports++; |
| } |
| } |
| if (element instanceof PyContinueStatement || element instanceof PyBreakStatement) { |
| final PyLoopStatement loopStatement = PsiTreeUtil.getParentOfType(element, PyLoopStatement.class); |
| if (loopStatement != null && !subGraphElements.contains(loopStatement)) { |
| outerLoopBreaks++; |
| } |
| } |
| if (element instanceof PyYieldExpression) { |
| yieldExpressions++; |
| } |
| } |
| |
| return new AnalysisResult(starImports, targetInstructions.size(), returnSources, regularSources, outerLoopBreaks, yieldExpressions); |
| } |
| |
| @NotNull |
| private static Set<Pair<Instruction, Instruction>> getOutgoingEdges(@NotNull Collection<Instruction> subGraph) { |
| final Set<Pair<Instruction, Instruction>> outgoing = new HashSet<Pair<Instruction, Instruction>>(); |
| for (Instruction instruction : subGraph) { |
| for (Instruction next : instruction.allSucc()) { |
| if (!subGraph.contains(next)) { |
| outgoing.add(Pair.create(instruction, next)); |
| } |
| } |
| } |
| return outgoing; |
| } |
| |
| @NotNull |
| public static List<PsiElement> getInputElements(@NotNull List<Instruction> subGraph, @NotNull List<Instruction> graph) { |
| final List<PsiElement> result = new ArrayList<PsiElement>(); |
| final Set<PsiElement> subGraphElements = getSubGraphElements(subGraph); |
| for (Instruction instruction : getReadInstructions(subGraph)) { |
| final PsiElement element = instruction.getElement(); |
| if (element != null) { |
| final PsiReference reference = element.getReference(); |
| if (reference != null) { |
| for (PsiElement resolved : multiResolve(reference)) { |
| if (!subGraphElements.contains(resolved)) { |
| result.add(element); |
| } |
| } |
| } |
| } |
| } |
| final List<PsiElement> outputElements = getOutputElements(subGraph, graph); |
| for (Instruction instruction : getWriteInstructions(subGraph)) { |
| final PsiElement element = instruction.getElement(); |
| if (element != null) { |
| final PsiReference reference = element.getReference(); |
| if (reference != null) { |
| for (PsiElement resolved : multiResolve(reference)) { |
| if (!subGraphElements.contains(resolved) && outputElements.contains(element)) { |
| result.add(element); |
| } |
| } |
| } |
| } |
| } |
| return result; |
| } |
| |
| @NotNull |
| private static List<PsiElement> getOutputElements(@NotNull List<Instruction> subGraph, @NotNull List<Instruction> graph) { |
| final List<PsiElement> result = new ArrayList<PsiElement>(); |
| final List<Instruction> outerGraph = new ArrayList<Instruction>(); |
| for (Instruction instruction : graph) { |
| if (!subGraph.contains(instruction)) { |
| outerGraph.add(instruction); |
| } |
| } |
| final Set<PsiElement> subGraphElements = getSubGraphElements(subGraph); |
| for (Instruction instruction : getReadInstructions(outerGraph)) { |
| final PsiElement element = instruction.getElement(); |
| if (element != null) { |
| final PsiReference reference = element.getReference(); |
| if (reference != null) { |
| for (PsiElement resolved : multiResolve(reference)) { |
| if (subGraphElements.contains(resolved)) { |
| result.add(resolved); |
| } |
| } |
| } |
| } |
| } |
| return result; |
| } |
| |
| private static List<PsiElement> filterElementsInScope(@NotNull Collection<PsiElement> elements, @NotNull ScopeOwner owner) { |
| final List<PsiElement> result = new ArrayList<PsiElement>(); |
| for (PsiElement element : elements) { |
| final PsiReference reference = element.getReference(); |
| if (reference != null) { |
| final PsiElement resolved = reference.resolve(); |
| if (resolved != null && ScopeUtil.getScopeOwner(resolved) == owner && !(owner instanceof PsiFile)) { |
| result.add(element); |
| } |
| } |
| } |
| return result; |
| } |
| |
| private static Set<PsiElement> getSubGraphElements(@NotNull List<Instruction> subGraph) { |
| final Set<PsiElement> result = new HashSet<PsiElement>(); |
| for (Instruction instruction : subGraph) { |
| final PsiElement element = instruction.getElement(); |
| if (element != null) { |
| result.add(element); |
| } |
| } |
| return result; |
| } |
| |
| @NotNull |
| private static Set<String> getGlobalWrites(@NotNull List<Instruction> instructions, @NotNull ScopeOwner owner) { |
| final Scope scope = ControlFlowCache.getScope(owner); |
| final Set<String> globalWrites = new LinkedHashSet<String>(); |
| for (Instruction instruction : getWriteInstructions(instructions)) { |
| if (instruction instanceof ReadWriteInstruction) { |
| final String name = ((ReadWriteInstruction)instruction).getName(); |
| if (scope.isGlobal(name) || owner instanceof PsiFile) { |
| globalWrites.add(name); |
| } |
| } |
| } |
| return globalWrites; |
| } |
| |
| @NotNull |
| private static Set<String> getNonlocalWrites(@NotNull List<Instruction> instructions, @NotNull ScopeOwner owner) { |
| final Scope scope = ControlFlowCache.getScope(owner); |
| final Set<String> nonlocalWrites = new LinkedHashSet<String>(); |
| for (Instruction instruction : getWriteInstructions(instructions)) { |
| if (instruction instanceof ReadWriteInstruction) { |
| final String name = ((ReadWriteInstruction)instruction).getName(); |
| if (scope.isNonlocal(name)) { |
| nonlocalWrites.add(name); |
| } |
| } |
| } |
| return nonlocalWrites; |
| } |
| |
| @NotNull |
| private static List<PsiElement> multiResolve(@NotNull PsiReference reference) { |
| if (reference instanceof PsiPolyVariantReference) { |
| final ResolveResult[] results = ((PsiPolyVariantReference)reference).multiResolve(false); |
| final List<PsiElement> resolved = new ArrayList<PsiElement>(); |
| for (ResolveResult result : results) { |
| final PsiElement element = result.getElement(); |
| if (element != null) { |
| resolved.add(element); |
| } |
| } |
| for (PsiElement element : resolved) { |
| if (element instanceof PyClass) { |
| return Collections.singletonList(element); |
| } |
| } |
| return resolved; |
| } |
| final PsiElement element = reference.resolve(); |
| if (element != null) { |
| return Collections.singletonList(element); |
| } |
| return Collections.emptyList(); |
| } |
| |
| private static List<Instruction> getReadInstructions(@NotNull List<Instruction> subGraph) { |
| final List<Instruction> result = new ArrayList<Instruction>(); |
| for (Instruction instruction : subGraph) { |
| if (instruction instanceof ReadWriteInstruction) { |
| final ReadWriteInstruction readWriteInstruction = (ReadWriteInstruction)instruction; |
| if (readWriteInstruction.getAccess().isReadAccess()) { |
| result.add(readWriteInstruction); |
| } |
| } |
| } |
| return result; |
| } |
| |
| private static List<Instruction> getWriteInstructions(@NotNull List<Instruction> subGraph) { |
| final List<Instruction> result = new ArrayList<Instruction>(); |
| for (Instruction instruction : subGraph) { |
| if (instruction instanceof ReadWriteInstruction) { |
| final ReadWriteInstruction readWriteInstruction = (ReadWriteInstruction)instruction; |
| if (readWriteInstruction.getAccess().isWriteAccess()) { |
| result.add(readWriteInstruction); |
| } |
| } |
| } |
| return result; |
| } |
| } |
