1 //===--- MisplacedArrayIndexCheck.cpp - clang-tidy-------------------------===// 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "MisplacedArrayIndexCheck.h" 10 #include "clang/AST/ASTContext.h" 11 #include "clang/ASTMatchers/ASTMatchFinder.h" 12 #include "clang/Lex/Lexer.h" 13 #include "clang/Tooling/FixIt.h" 14 15 using namespace clang::ast_matchers; 16 17 namespace clang { 18 namespace tidy { 19 namespace readability { 20 21 void MisplacedArrayIndexCheck::registerMatchers(MatchFinder *Finder) { 22 Finder->addMatcher( 23 traverse(ast_type_traits::TK_AsIs, 24 arraySubscriptExpr(hasLHS(hasType(isInteger())), 25 hasRHS(hasType(isAnyPointer()))) 26 .bind("expr")), 27 this); 28 } 29 30 void MisplacedArrayIndexCheck::check(const MatchFinder::MatchResult &Result) { 31 const auto *ArraySubscriptE = 32 Result.Nodes.getNodeAs<ArraySubscriptExpr>("expr"); 33 34 auto Diag = diag(ArraySubscriptE->getBeginLoc(), "confusing array subscript " 35 "expression, usually the " 36 "index is inside the []"); 37 38 // Only try to fixit when LHS and RHS can be swapped directly without changing 39 // the logic. 40 const Expr *RHSE = ArraySubscriptE->getRHS()->IgnoreParenImpCasts(); 41 if (!isa<StringLiteral>(RHSE) && !isa<DeclRefExpr>(RHSE) && 42 !isa<MemberExpr>(RHSE)) 43 return; 44 45 const StringRef LText = tooling::fixit::getText( 46 ArraySubscriptE->getLHS()->getSourceRange(), *Result.Context); 47 const StringRef RText = tooling::fixit::getText( 48 ArraySubscriptE->getRHS()->getSourceRange(), *Result.Context); 49 50 Diag << FixItHint::CreateReplacement( 51 ArraySubscriptE->getLHS()->getSourceRange(), RText); 52 Diag << FixItHint::CreateReplacement( 53 ArraySubscriptE->getRHS()->getSourceRange(), LText); 54 } 55 56 } // namespace readability 57 } // namespace tidy 58 } // namespace clang 59