================ @@ -0,0 +1,74 @@ +//===----------------------------------------------------------------------===// +// +// 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 "ReplaceWithStringViewCheck.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" + +using namespace clang::ast_matchers; + +namespace clang::tidy::performance { + +static llvm::StringLiteral toStringViewTypeStr(StringRef Type) { + if (Type.contains("wchar_t")) + return "std::wstring_view"; + if (Type.contains("wchar_t")) + return "std::wstring_view"; + if (Type.contains("char8_t")) + return "std::u8string_view"; + if (Type.contains("char16_t")) + return "std::u16string_view"; + if (Type.contains("char32_t")) + return "std::u32string_view"; + return "std::string_view"; +} + +void ReplaceWithStringViewCheck::registerMatchers(MatchFinder *Finder) { + const auto IsStdString = hasCanonicalType( + hasDeclaration(cxxRecordDecl(hasName("::std::basic_string")))); + const auto IsStdStringView = expr(hasType(hasCanonicalType( + hasDeclaration(cxxRecordDecl(hasName("::std::basic_string_view")))))); + + Finder->addMatcher( + functionDecl( + isDefinition(), + unless(cxxMethodDecl(anyOf(isOverride(), isVirtual()))), + returns(IsStdString), hasDescendant(returnStmt()), + unless(hasDescendant( + returnStmt(hasReturnValue(unless(ignoringImplicit(anyOf( + stringLiteral(), IsStdStringView, + cxxConstructExpr( + hasType(IsStdString), + anyOf(argumentCountIs(0), + hasArgument(0, ignoringParenImpCasts(anyOf( + stringLiteral(), + IsStdStringView))))))))))))) + .bind("func"), + this); +} + +void ReplaceWithStringViewCheck::check(const MatchFinder::MatchResult &Result) { + const auto *MatchedDecl = Result.Nodes.getNodeAs<FunctionDecl>("func"); + assert(MatchedDecl); + const llvm::StringLiteral DestReturnTypeStr = + toStringViewTypeStr(MatchedDecl->getReturnType() + .getDesugaredType(*Result.Context) + .getAsString()); + + auto Diag = diag(MatchedDecl->getReturnTypeSourceRange().getBegin(), + "consider using '%0' to avoid unnecessary " + "copying and allocations") + << DestReturnTypeStr << MatchedDecl; ---------------- zwuis wrote:
What's the output of `<< MatchedDecl`? https://github.com/llvm/llvm-project/pull/172170 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
