================ @@ -0,0 +1,95 @@ +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "LoopVariableCopiedThenModifiedCheck.h" +#include "../utils/Matchers.h" +#include "../utils/TypeTraits.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/Analysis/Analyses/ExprMutationAnalyzer.h" +#include "clang/Basic/Diagnostic.h" +#include "clang/Lex/Lexer.h" + +using namespace clang::ast_matchers; + +namespace clang::tidy::bugprone { + +namespace { +AST_MATCHER(VarDecl, isInMacro) { return Node.getBeginLoc().isMacroID(); } +} // namespace + +LoopVariableCopiedThenModifiedCheck::LoopVariableCopiedThenModifiedCheck( + StringRef Name, ClangTidyContext *Context) + : ClangTidyCheck(Name, Context), IgnoreInexpensiveVariables(Options.get( + "IgnoreInexpensiveVariables", false)), + WarnOnlyOnAutoCopies(Options.get("WarnOnlyOnAutoCopies", false)) {} + +void LoopVariableCopiedThenModifiedCheck::storeOptions( + ClangTidyOptions::OptionMap &Opts) { + Options.store(Opts, "IgnoreInexpensiveVariables", IgnoreInexpensiveVariables); + Options.store(Opts, "WarnOnlyOnAutoCopies", WarnOnlyOnAutoCopies); +} + +void LoopVariableCopiedThenModifiedCheck::registerMatchers( + MatchFinder *Finder) { + const auto HasReferenceOrPointerType = hasType(qualType( + unless(hasCanonicalType(anyOf(referenceType(), pointerType()))))); + const auto IteratorReturnsValueType = cxxOperatorCallExpr( + hasOverloadedOperatorName("*"), + callee( + cxxMethodDecl(returns(unless(hasCanonicalType(referenceType())))))); + const auto NotConstructedByCopy = cxxConstructExpr( + hasDeclaration(cxxConstructorDecl(unless(isCopyConstructor())))); + const auto ConstructedByConversion = + cxxMemberCallExpr(callee(cxxConversionDecl())); + const auto LoopVar = + varDecl(unless(isInMacro()), HasReferenceOrPointerType, + unless(hasInitializer(expr(hasDescendant(expr( + anyOf(materializeTemporaryExpr(), IteratorReturnsValueType, + NotConstructedByCopy, ConstructedByConversion))))))); + Finder->addMatcher(cxxForRangeStmt(hasLoopVariable(LoopVar.bind("loopVar"))) + .bind("forRange"), + this); +} + +void LoopVariableCopiedThenModifiedCheck::check( + const MatchFinder::MatchResult &Result) { + const auto *LoopVar = Result.Nodes.getNodeAs<VarDecl>("loopVar"); + std::optional<bool> Expensive = utils::type_traits::isExpensiveToCopy( + LoopVar->getType(), *Result.Context); + if ((!Expensive || !*Expensive) && IgnoreInexpensiveVariables) + return; + if (WarnOnlyOnAutoCopies) { + if (!isa<AutoType>(LoopVar->getType())) { + return; + } + } + const auto *ForRange = Result.Nodes.getNodeAs<CXXForRangeStmt>("forRange"); + + if (!ExprMutationAnalyzer(*ForRange->getBody(), *Result.Context) + .isMutated(LoopVar)) { + return; + } + + clang::SourceRange LoopVarSourceRange = + LoopVar->getTypeSourceInfo()->getTypeLoc().getSourceRange(); + clang::SourceLocation EndLoc = clang::Lexer::getLocForEndOfToken( + LoopVarSourceRange.getEnd(), 0, Result.Context->getSourceManager(), + Result.Context->getLangOpts()); + diag(LoopVar->getLocation(), + "loop variable '%0' is copied and then (possibly) modified; use an " + "explicit copy inside the body of the loop or make the variable a " + "reference") + << LoopVar->getName(); + diag(LoopVar->getLocation(), "consider making '%0' a reference", + DiagnosticIDs::Note) + << LoopVar->getName() + << FixItHint::CreateInsertion(LoopVarSourceRange.getBegin(), "const ") + << FixItHint::CreateInsertion(EndLoc, "&"); +} + +} // namespace clang::tidy::bugprone ---------------- EugeneZelenko wrote:
Please add newline. https://github.com/llvm/llvm-project/pull/157213 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
