| //===--- CopyConstructorInitCheck.cpp - clang-tidy-------------------------===// |
| // |
| // 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 "CopyConstructorInitCheck.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/ASTMatchers/ASTMatchFinder.h" |
| #include "clang/Lex/Lexer.h" |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace bugprone { |
| |
| void CopyConstructorInitCheck::registerMatchers(MatchFinder *Finder) { |
| // In the future this might be extended to move constructors? |
| Finder->addMatcher( |
| cxxConstructorDecl( |
| isCopyConstructor(), |
| hasAnyConstructorInitializer(cxxCtorInitializer( |
| isBaseInitializer(), |
| withInitializer(cxxConstructExpr(hasDeclaration( |
| cxxConstructorDecl(isDefaultConstructor())))))), |
| unless(isInstantiated())) |
| .bind("ctor"), |
| this); |
| } |
| |
| void CopyConstructorInitCheck::check(const MatchFinder::MatchResult &Result) { |
| const auto *Ctor = Result.Nodes.getNodeAs<CXXConstructorDecl>("ctor"); |
| std::string ParamName = Ctor->getParamDecl(0)->getNameAsString(); |
| |
| // We want only one warning (and FixIt) for each ctor. |
| std::string FixItInitList; |
| bool HasRelevantBaseInit = false; |
| bool ShouldNotDoFixit = false; |
| bool HasWrittenInitializer = false; |
| SmallVector<FixItHint, 2> SafeFixIts; |
| for (const auto *Init : Ctor->inits()) { |
| bool CtorInitIsWritten = Init->isWritten(); |
| HasWrittenInitializer = HasWrittenInitializer || CtorInitIsWritten; |
| if (!Init->isBaseInitializer()) |
| continue; |
| const Type *BaseType = Init->getBaseClass(); |
| // Do not do fixits if there is a type alias involved or one of the bases |
| // are explicitly initialized. In the latter case we not do fixits to avoid |
| // -Wreorder warnings. |
| if (const auto *TempSpecTy = dyn_cast<TemplateSpecializationType>(BaseType)) |
| ShouldNotDoFixit = ShouldNotDoFixit || TempSpecTy->isTypeAlias(); |
| ShouldNotDoFixit = ShouldNotDoFixit || isa<TypedefType>(BaseType); |
| ShouldNotDoFixit = ShouldNotDoFixit || CtorInitIsWritten; |
| const CXXRecordDecl *BaseClass = |
| BaseType->getAsCXXRecordDecl()->getDefinition(); |
| if (BaseClass->field_empty() && |
| BaseClass->forallBases( |
| [](const CXXRecordDecl *Class) { return Class->field_empty(); })) |
| continue; |
| bool NonCopyableBase = false; |
| for (const auto *Ctor : BaseClass->ctors()) { |
| if (Ctor->isCopyConstructor() && |
| (Ctor->getAccess() == AS_private || Ctor->isDeleted())) { |
| NonCopyableBase = true; |
| break; |
| } |
| } |
| if (NonCopyableBase) |
| continue; |
| const auto *CExpr = dyn_cast<CXXConstructExpr>(Init->getInit()); |
| if (!CExpr || !CExpr->getConstructor()->isDefaultConstructor()) |
| continue; |
| HasRelevantBaseInit = true; |
| if (CtorInitIsWritten) { |
| if (!ParamName.empty()) |
| SafeFixIts.push_back( |
| FixItHint::CreateInsertion(CExpr->getEndLoc(), ParamName)); |
| } else { |
| if (Init->getSourceLocation().isMacroID() || |
| Ctor->getLocation().isMacroID() || ShouldNotDoFixit) |
| break; |
| FixItInitList += BaseClass->getNameAsString(); |
| FixItInitList += "(" + ParamName + "), "; |
| } |
| } |
| if (!HasRelevantBaseInit) |
| return; |
| |
| auto Diag = diag(Ctor->getLocation(), |
| "calling a base constructor other than the copy constructor") |
| << SafeFixIts; |
| |
| if (FixItInitList.empty() || ParamName.empty() || ShouldNotDoFixit) |
| return; |
| |
| std::string FixItMsg{FixItInitList.substr(0, FixItInitList.size() - 2)}; |
| SourceLocation FixItLoc; |
| // There is no initialization list in this constructor. |
| if (!HasWrittenInitializer) { |
| FixItLoc = Ctor->getBody()->getBeginLoc(); |
| FixItMsg = " : " + FixItMsg; |
| } else { |
| // We apply the missing ctors at the beginning of the initialization list. |
| FixItLoc = (*Ctor->init_begin())->getSourceLocation(); |
| FixItMsg += ','; |
| } |
| FixItMsg += ' '; |
| |
| Diag << FixItHint::CreateInsertion(FixItLoc, FixItMsg); |
| } |
| |
| } // namespace bugprone |
| } // namespace tidy |
| } // namespace clang |