103 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "MisleadingCaptureDefaultByValueCheck.h"10#include "../utils/LexerUtils.h"11#include "clang/AST/ASTContext.h"12#include "clang/ASTMatchers/ASTMatchFinder.h"13#include "llvm/Support/raw_ostream.h"14 15#include <algorithm>16 17using namespace clang::ast_matchers;18 19namespace clang::tidy::cppcoreguidelines {20 21MisleadingCaptureDefaultByValueCheck::MisleadingCaptureDefaultByValueCheck(22 StringRef Name, ClangTidyContext *Context)23 : ClangTidyCheck(Name, Context) {}24 25void MisleadingCaptureDefaultByValueCheck::registerMatchers(26 MatchFinder *Finder) {27 Finder->addMatcher(lambdaExpr(hasAnyCapture(capturesThis())).bind("lambda"),28 this);29}30 31static SourceLocation findDefaultCaptureEnd(const LambdaExpr *Lambda,32 ASTContext &Context) {33 for (const LambdaCapture &Capture : Lambda->explicit_captures()) {34 if (Capture.isExplicit()) {35 if (Capture.getCaptureKind() == LCK_ByRef) {36 const SourceManager &SourceMgr = Context.getSourceManager();37 SourceLocation AddressofLoc = utils::lexer::findPreviousTokenKind(38 Capture.getLocation(), SourceMgr, Context.getLangOpts(), tok::amp);39 return AddressofLoc;40 }41 return Capture.getLocation();42 }43 }44 return Lambda->getIntroducerRange().getEnd();45}46 47static std::string createReplacementText(const LambdaExpr *Lambda) {48 std::string Replacement;49 llvm::raw_string_ostream Stream(Replacement);50 51 auto AppendName = [&](llvm::StringRef Name) {52 if (!Replacement.empty()) {53 Stream << ", ";54 }55 if (Lambda->getCaptureDefault() == LCD_ByRef && Name != "this") {56 Stream << "&" << Name;57 } else {58 Stream << Name;59 }60 };61 62 for (const LambdaCapture &Capture : Lambda->implicit_captures()) {63 assert(Capture.isImplicit());64 if (Capture.capturesVariable() && Capture.isImplicit()) {65 AppendName(Capture.getCapturedVar()->getName());66 } else if (Capture.capturesThis()) {67 AppendName("this");68 }69 }70 if (!Replacement.empty() && !Lambda->explicit_captures().empty()) {71 // Add back separator if we are adding explicit capture variables.72 Stream << ", ";73 }74 return Replacement;75}76 77void MisleadingCaptureDefaultByValueCheck::check(78 const MatchFinder::MatchResult &Result) {79 const auto *Lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");80 if (!Lambda)81 return;82 83 if (Lambda->getCaptureDefault() == LCD_ByCopy) {84 const bool IsThisImplicitlyCaptured = std::any_of(85 Lambda->implicit_capture_begin(), Lambda->implicit_capture_end(),86 [](const LambdaCapture &Capture) { return Capture.capturesThis(); });87 auto Diag = diag(Lambda->getCaptureDefaultLoc(),88 "lambdas that %select{|implicitly }0capture 'this' "89 "should not specify a by-value capture default")90 << IsThisImplicitlyCaptured;91 92 const std::string ReplacementText = createReplacementText(Lambda);93 const SourceLocation DefaultCaptureEnd =94 findDefaultCaptureEnd(Lambda, *Result.Context);95 Diag << FixItHint::CreateReplacement(96 CharSourceRange::getCharRange(Lambda->getCaptureDefaultLoc(),97 DefaultCaptureEnd),98 ReplacementText);99 }100}101 102} // namespace clang::tidy::cppcoreguidelines103