64 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 "TwineLocalCheck.h"10#include "clang/AST/ASTContext.h"11#include "clang/ASTMatchers/ASTMatchers.h"12#include "clang/Lex/Lexer.h"13 14using namespace clang::ast_matchers;15 16namespace clang::tidy::llvm_check {17 18void TwineLocalCheck::registerMatchers(MatchFinder *Finder) {19 auto TwineType =20 qualType(hasDeclaration(cxxRecordDecl(hasName("::llvm::Twine"))));21 Finder->addMatcher(22 varDecl(unless(parmVarDecl()), hasType(TwineType)).bind("variable"),23 this);24}25 26void TwineLocalCheck::check(const MatchFinder::MatchResult &Result) {27 const auto *VD = Result.Nodes.getNodeAs<VarDecl>("variable");28 auto Diag = diag(VD->getLocation(),29 "twine variables are prone to use-after-free bugs");30 31 // If this VarDecl has an initializer try to fix it.32 if (VD->hasInit()) {33 // Peel away implicit constructors and casts so we can see the actual type34 // of the initializer.35 const Expr *C = VD->getInit()->IgnoreImplicit();36 37 while (isa<CXXConstructExpr>(C)) {38 if (cast<CXXConstructExpr>(C)->getNumArgs() == 0)39 break;40 C = cast<CXXConstructExpr>(C)->getArg(0)->IgnoreParenImpCasts();41 }42 43 const SourceRange TypeRange =44 VD->getTypeSourceInfo()->getTypeLoc().getSourceRange();45 46 // A real Twine, turn it into a std::string.47 if (VD->getType()->getCanonicalTypeUnqualified() ==48 C->getType()->getCanonicalTypeUnqualified()) {49 const SourceLocation EndLoc = Lexer::getLocForEndOfToken(50 VD->getInit()->getEndLoc(), 0, *Result.SourceManager, getLangOpts());51 Diag << FixItHint::CreateReplacement(TypeRange, "std::string")52 << FixItHint::CreateInsertion(VD->getInit()->getBeginLoc(), "(")53 << FixItHint::CreateInsertion(EndLoc, ").str()");54 } else {55 // Just an implicit conversion. Insert the real type.56 Diag << FixItHint::CreateReplacement(57 TypeRange,58 C->getType().getAsString(Result.Context->getPrintingPolicy()));59 }60 }61}62 63} // namespace clang::tidy::llvm_check64