| //===--- QualifiedAutoCheck.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 "QualifiedAutoCheck.h" |
| #include "../utils/LexerUtils.h" |
| #include "clang/ASTMatchers/ASTMatchers.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/ADT/SmallVector.h" |
| |
| using namespace clang::ast_matchers; |
| |
| namespace clang { |
| namespace tidy { |
| namespace readability { |
| |
| namespace { |
| |
| // FIXME move to ASTMatchers |
| AST_MATCHER_P(QualType, hasUnqualifiedType, |
| ast_matchers::internal::Matcher<QualType>, InnerMatcher) { |
| return InnerMatcher.matches(Node.getUnqualifiedType(), Finder, Builder); |
| } |
| |
| enum class Qualifier { Const, Volatile, Restrict }; |
| |
| llvm::Optional<Token> findQualToken(const VarDecl *Decl, Qualifier Qual, |
| const MatchFinder::MatchResult &Result) { |
| // Since either of the locs can be in a macro, use `makeFileCharRange` to be |
| // sure that we have a consistent `CharSourceRange`, located entirely in the |
| // source file. |
| |
| assert(Qual == Qualifier::Const || Qual == Qualifier::Volatile || |
| Qual == Qualifier::Restrict && "Invalid Qualifier"); |
| |
| SourceLocation BeginLoc = Decl->getQualifierLoc().getBeginLoc(); |
| if (BeginLoc.isInvalid()) |
| BeginLoc = Decl->getBeginLoc(); |
| SourceLocation EndLoc = Decl->getLocation(); |
| |
| CharSourceRange FileRange = Lexer::makeFileCharRange( |
| CharSourceRange::getCharRange(BeginLoc, EndLoc), *Result.SourceManager, |
| Result.Context->getLangOpts()); |
| |
| if (FileRange.isInvalid()) |
| return llvm::None; |
| |
| tok::TokenKind Tok = |
| Qual == Qualifier::Const |
| ? tok::kw_const |
| : Qual == Qualifier::Volatile ? tok::kw_volatile : tok::kw_restrict; |
| |
| return utils::lexer::getQualifyingToken(Tok, FileRange, *Result.Context, |
| *Result.SourceManager); |
| } |
| |
| llvm::Optional<SourceRange> |
| getTypeSpecifierLocation(const VarDecl *Var, |
| const MatchFinder::MatchResult &Result) { |
| SourceRange TypeSpecifier( |
| Var->getTypeSpecStartLoc(), |
| Var->getTypeSpecEndLoc().getLocWithOffset(Lexer::MeasureTokenLength( |
| Var->getTypeSpecEndLoc(), *Result.SourceManager, |
| Result.Context->getLangOpts()))); |
| |
| if (TypeSpecifier.getBegin().isMacroID() || |
| TypeSpecifier.getEnd().isMacroID()) |
| return llvm::None; |
| return TypeSpecifier; |
| } |
| |
| llvm::Optional<SourceRange> mergeReplacementRange(SourceRange &TypeSpecifier, |
| const Token &ConstToken) { |
| if (TypeSpecifier.getBegin().getLocWithOffset(-1) == ConstToken.getEndLoc()) { |
| TypeSpecifier.setBegin(ConstToken.getLocation()); |
| return llvm::None; |
| } |
| if (TypeSpecifier.getEnd().getLocWithOffset(1) == ConstToken.getLocation()) { |
| TypeSpecifier.setEnd(ConstToken.getEndLoc()); |
| return llvm::None; |
| } |
| return SourceRange(ConstToken.getLocation(), ConstToken.getEndLoc()); |
| } |
| |
| bool isPointerConst(QualType QType) { |
| QualType Pointee = QType->getPointeeType(); |
| assert(!Pointee.isNull() && "can't have a null Pointee"); |
| return Pointee.isConstQualified(); |
| } |
| |
| bool isAutoPointerConst(QualType QType) { |
| QualType Pointee = |
| cast<AutoType>(QType->getPointeeType().getTypePtr())->desugar(); |
| assert(!Pointee.isNull() && "can't have a null Pointee"); |
| return Pointee.isConstQualified(); |
| } |
| |
| } // namespace |
| |
| void QualifiedAutoCheck::registerMatchers(MatchFinder *Finder) { |
| if (!getLangOpts().CPlusPlus11) |
| return; // Auto deduction not used in 'C or C++03 and earlier', so don't |
| // register Matchers. |
| auto ExplicitSingleVarDecl = |
| [](const ast_matchers::internal::Matcher<VarDecl> &InnerMatcher, |
| llvm::StringRef ID) { |
| return declStmt( |
| unless(isInTemplateInstantiation()), |
| hasSingleDecl( |
| varDecl(unless(isImplicit()), InnerMatcher).bind(ID))); |
| }; |
| auto ExplicitSingleVarDeclInTemplate = |
| [](const ast_matchers::internal::Matcher<VarDecl> &InnerMatcher, |
| llvm::StringRef ID) { |
| return declStmt( |
| isInTemplateInstantiation(), |
| hasSingleDecl( |
| varDecl(unless(isImplicit()), InnerMatcher).bind(ID))); |
| }; |
| |
| auto IsBoundToType = refersToType(equalsBoundNode("type")); |
| |
| Finder->addMatcher( |
| ExplicitSingleVarDecl(hasType(autoType(hasDeducedType( |
| pointerType(pointee(unless(functionType())))))), |
| "auto"), |
| this); |
| |
| Finder->addMatcher( |
| ExplicitSingleVarDeclInTemplate( |
| allOf(hasType(autoType(hasDeducedType(pointerType( |
| pointee(hasUnqualifiedType(qualType().bind("type")), |
| unless(functionType())))))), |
| anyOf(hasAncestor( |
| functionDecl(hasAnyTemplateArgument(IsBoundToType))), |
| hasAncestor(classTemplateSpecializationDecl( |
| hasAnyTemplateArgument(IsBoundToType))))), |
| "auto"), |
| this); |
| Finder->addMatcher(ExplicitSingleVarDecl( |
| hasType(pointerType(pointee(autoType()))), "auto_ptr"), |
| this); |
| Finder->addMatcher( |
| ExplicitSingleVarDecl(hasType(lValueReferenceType(pointee(autoType()))), |
| "auto_ref"), |
| this); |
| } |
| |
| void QualifiedAutoCheck::check(const MatchFinder::MatchResult &Result) { |
| if (const auto *Var = Result.Nodes.getNodeAs<VarDecl>("auto")) { |
| SourceRange TypeSpecifier; |
| if (llvm::Optional<SourceRange> TypeSpec = |
| getTypeSpecifierLocation(Var, Result)) { |
| TypeSpecifier = *TypeSpec; |
| } else |
| return; |
| |
| llvm::SmallVector<SourceRange, 4> RemoveQualifiersRange; |
| auto CheckQualifier = [&](bool IsPresent, Qualifier Qual) { |
| if (IsPresent) { |
| llvm::Optional<Token> Token = findQualToken(Var, Qual, Result); |
| if (!Token || Token->getLocation().isMacroID()) |
| return true; // Disregard this VarDecl. |
| if (llvm::Optional<SourceRange> Result = |
| mergeReplacementRange(TypeSpecifier, *Token)) |
| RemoveQualifiersRange.push_back(*Result); |
| } |
| return false; |
| }; |
| |
| bool IsLocalConst = Var->getType().isLocalConstQualified(); |
| bool IsLocalVolatile = Var->getType().isLocalVolatileQualified(); |
| bool IsLocalRestrict = Var->getType().isLocalRestrictQualified(); |
| |
| if (CheckQualifier(IsLocalConst, Qualifier::Const)) |
| return; |
| if (CheckQualifier(IsLocalVolatile, Qualifier::Volatile)) |
| return; |
| if (CheckQualifier(IsLocalRestrict, Qualifier::Restrict)) |
| return; |
| |
| // Check for bridging the gap between the asterisk and name. |
| if (Var->getLocation() == TypeSpecifier.getEnd().getLocWithOffset(1)) |
| TypeSpecifier.setEnd(TypeSpecifier.getEnd().getLocWithOffset(1)); |
| |
| CharSourceRange FixItRange = CharSourceRange::getCharRange(TypeSpecifier); |
| if (FixItRange.isInvalid()) |
| return; |
| |
| SourceLocation FixitLoc = FixItRange.getBegin(); |
| for (SourceRange &Range : RemoveQualifiersRange) { |
| if (Range.getBegin() < FixitLoc) |
| FixitLoc = Range.getBegin(); |
| } |
| |
| std::string ReplStr = [&] { |
| llvm::StringRef PtrConst = isPointerConst(Var->getType()) ? "const " : ""; |
| llvm::StringRef LocalConst = IsLocalConst ? "const " : ""; |
| llvm::StringRef LocalVol = IsLocalVolatile ? "volatile " : ""; |
| llvm::StringRef LocalRestrict = IsLocalRestrict ? "__restrict " : ""; |
| return (PtrConst + "auto *" + LocalConst + LocalVol + LocalRestrict) |
| .str(); |
| }(); |
| |
| DiagnosticBuilder Diag = |
| diag(FixitLoc, "'%0%1%2auto %3' can be declared as '%4%3'") |
| << (IsLocalConst ? "const " : "") |
| << (IsLocalVolatile ? "volatile " : "") |
| << (IsLocalRestrict ? "__restrict " : "") << Var->getName() << ReplStr; |
| |
| for (SourceRange &Range : RemoveQualifiersRange) { |
| Diag << FixItHint::CreateRemoval( |
| CharSourceRange::getCharRange(Range.getBegin(), Range.getEnd())); |
| } |
| |
| Diag << FixItHint::CreateReplacement(FixItRange, ReplStr); |
| return; |
| } |
| if (const auto *Var = Result.Nodes.getNodeAs<VarDecl>("auto_ptr")) { |
| if (!isPointerConst(Var->getType())) |
| return; // Pointer isn't const, no need to add const qualifier. |
| if (!isAutoPointerConst(Var->getType())) |
| return; // Const isnt wrapped in the auto type, so must be declared |
| // explicitly. |
| |
| if (Var->getType().isLocalConstQualified()) { |
| llvm::Optional<Token> Token = |
| findQualToken(Var, Qualifier::Const, Result); |
| if (!Token || Token->getLocation().isMacroID()) |
| return; |
| } |
| if (Var->getType().isLocalVolatileQualified()) { |
| llvm::Optional<Token> Token = |
| findQualToken(Var, Qualifier::Volatile, Result); |
| if (!Token || Token->getLocation().isMacroID()) |
| return; |
| } |
| if (Var->getType().isLocalRestrictQualified()) { |
| llvm::Optional<Token> Token = |
| findQualToken(Var, Qualifier::Restrict, Result); |
| if (!Token || Token->getLocation().isMacroID()) |
| return; |
| } |
| |
| CharSourceRange FixItRange; |
| if (llvm::Optional<SourceRange> TypeSpec = |
| getTypeSpecifierLocation(Var, Result)) { |
| FixItRange = CharSourceRange::getCharRange(*TypeSpec); |
| if (FixItRange.isInvalid()) |
| return; |
| } else |
| return; |
| |
| DiagnosticBuilder Diag = |
| diag(FixItRange.getBegin(), |
| "'auto *%0%1%2' can be declared as 'const auto *%0%1%2'") |
| << (Var->getType().isLocalConstQualified() ? "const " : "") |
| << (Var->getType().isLocalVolatileQualified() ? "volatile " : "") |
| << Var->getName(); |
| Diag << FixItHint::CreateReplacement(FixItRange, "const auto *"); |
| return; |
| } |
| if (const auto *Var = Result.Nodes.getNodeAs<VarDecl>("auto_ref")) { |
| if (!isPointerConst(Var->getType())) |
| return; // Pointer isn't const, no need to add const qualifier. |
| if (!isAutoPointerConst(Var->getType())) |
| // Const isnt wrapped in the auto type, so must be declared explicitly. |
| return; |
| |
| CharSourceRange FixItRange; |
| if (llvm::Optional<SourceRange> TypeSpec = |
| getTypeSpecifierLocation(Var, Result)) { |
| FixItRange = CharSourceRange::getCharRange(*TypeSpec); |
| if (FixItRange.isInvalid()) |
| return; |
| } else |
| return; |
| |
| DiagnosticBuilder Diag = |
| diag(FixItRange.getBegin(), |
| "'auto &%0' can be declared as 'const auto &%0'") |
| << Var->getName(); |
| Diag << FixItHint::CreateReplacement(FixItRange, "const auto &"); |
| return; |
| } |
| } |
| |
| } // namespace readability |
| } // namespace tidy |
| } // namespace clang |
