146 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 "StringFindStartswithCheck.h"10 11#include "../utils/OptionsUtils.h"12#include "clang/AST/ASTContext.h"13#include "clang/ASTMatchers/ASTMatchers.h"14#include "clang/Frontend/CompilerInstance.h"15#include "clang/Lex/Lexer.h"16#include "clang/Lex/Preprocessor.h"17 18using namespace clang::ast_matchers;19 20namespace clang::tidy::abseil {21 22const auto DefaultStringLikeClasses =23 "::std::basic_string;::std::basic_string_view";24 25StringFindStartswithCheck::StringFindStartswithCheck(StringRef Name,26 ClangTidyContext *Context)27 : ClangTidyCheck(Name, Context),28 StringLikeClasses(utils::options::parseStringList(29 Options.get("StringLikeClasses", DefaultStringLikeClasses))),30 IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",31 utils::IncludeSorter::IS_LLVM),32 areDiagsSelfContained()),33 AbseilStringsMatchHeader(34 Options.get("AbseilStringsMatchHeader", "absl/strings/match.h")) {}35 36void StringFindStartswithCheck::registerMatchers(MatchFinder *Finder) {37 auto ZeroLiteral = integerLiteral(equals(0));38 auto StringClassMatcher = cxxRecordDecl(hasAnyName(StringLikeClasses));39 auto StringType = hasUnqualifiedDesugaredType(40 recordType(hasDeclaration(StringClassMatcher)));41 42 auto StringFind = cxxMemberCallExpr(43 // .find()-call on a string...44 callee(cxxMethodDecl(hasName("find")).bind("findfun")),45 on(hasType(StringType)),46 // ... with some search expression ...47 hasArgument(0, expr().bind("needle")),48 // ... and either "0" as second argument or the default argument (also 0).49 anyOf(hasArgument(1, ZeroLiteral), hasArgument(1, cxxDefaultArgExpr())));50 51 Finder->addMatcher(52 // Match [=!]= with a zero on one side and a string.find on the other.53 binaryOperator(54 hasAnyOperatorName("==", "!="),55 hasOperands(ignoringParenImpCasts(ZeroLiteral),56 ignoringParenImpCasts(StringFind.bind("findexpr"))))57 .bind("expr"),58 this);59 60 auto StringRFind = cxxMemberCallExpr(61 // .rfind()-call on a string...62 callee(cxxMethodDecl(hasName("rfind")).bind("findfun")),63 on(hasType(StringType)),64 // ... with some search expression ...65 hasArgument(0, expr().bind("needle")),66 // ... and "0" as second argument.67 hasArgument(1, ZeroLiteral));68 69 Finder->addMatcher(70 // Match [=!]= with either a zero or npos on one side and a string.rfind71 // on the other.72 binaryOperator(73 hasAnyOperatorName("==", "!="),74 hasOperands(ignoringParenImpCasts(ZeroLiteral),75 ignoringParenImpCasts(StringRFind.bind("findexpr"))))76 .bind("expr"),77 this);78}79 80void StringFindStartswithCheck::check(const MatchFinder::MatchResult &Result) {81 const ASTContext &Context = *Result.Context;82 const SourceManager &Source = Context.getSourceManager();83 84 // Extract matching (sub)expressions85 const auto *ComparisonExpr = Result.Nodes.getNodeAs<BinaryOperator>("expr");86 assert(ComparisonExpr != nullptr);87 const auto *Needle = Result.Nodes.getNodeAs<Expr>("needle");88 assert(Needle != nullptr);89 const Expr *Haystack = Result.Nodes.getNodeAs<CXXMemberCallExpr>("findexpr")90 ->getImplicitObjectArgument();91 assert(Haystack != nullptr);92 const auto *FindFun = Result.Nodes.getNodeAs<CXXMethodDecl>("findfun");93 assert(FindFun != nullptr);94 95 const bool Rev = FindFun->getName().contains("rfind");96 97 if (ComparisonExpr->getBeginLoc().isMacroID())98 return;99 100 // Get the source code blocks (as characters) for both the string object101 // and the search expression102 const StringRef NeedleExprCode = Lexer::getSourceText(103 CharSourceRange::getTokenRange(Needle->getSourceRange()), Source,104 Context.getLangOpts());105 const StringRef HaystackExprCode = Lexer::getSourceText(106 CharSourceRange::getTokenRange(Haystack->getSourceRange()), Source,107 Context.getLangOpts());108 109 // Create the StartsWith string, negating if comparison was "!=".110 const bool Neg = ComparisonExpr->getOpcode() == BO_NE;111 112 // Create the warning message and a FixIt hint replacing the original expr.113 auto Diagnostic =114 diag(ComparisonExpr->getBeginLoc(),115 "use %select{absl::StartsWith|!absl::StartsWith}0 "116 "instead of %select{find()|rfind()}1 %select{==|!=}0 0")117 << Neg << Rev;118 119 Diagnostic << FixItHint::CreateReplacement(120 ComparisonExpr->getSourceRange(),121 ((Neg ? "!absl::StartsWith(" : "absl::StartsWith(") + HaystackExprCode +122 ", " + NeedleExprCode + ")")123 .str());124 125 // Create a preprocessor #include FixIt hint (createIncludeInsertion checks126 // whether this already exists).127 Diagnostic << IncludeInserter.createIncludeInsertion(128 Source.getFileID(ComparisonExpr->getBeginLoc()),129 AbseilStringsMatchHeader);130}131 132void StringFindStartswithCheck::registerPPCallbacks(133 const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {134 IncludeInserter.registerPreprocessor(PP);135}136 137void StringFindStartswithCheck::storeOptions(138 ClangTidyOptions::OptionMap &Opts) {139 Options.store(Opts, "StringLikeClasses",140 utils::options::serializeStringList(StringLikeClasses));141 Options.store(Opts, "IncludeStyle", IncludeInserter.getStyle());142 Options.store(Opts, "AbseilStringsMatchHeader", AbseilStringsMatchHeader);143}144 145} // namespace clang::tidy::abseil146