================ @@ -0,0 +1,199 @@ +//===--- EnumInitialValueCheck.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 "EnumInitialValueCheck.h" +#include "../utils/LexerUtils.h" +#include "clang/AST/Decl.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" +#include "clang/Basic/Diagnostic.h" +#include "clang/Basic/SourceLocation.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallString.h" + +using namespace clang::ast_matchers; + +namespace clang::tidy::readability { + +static bool isNoneEnumeratorsInitialized(const EnumDecl &Node) { + return llvm::all_of(Node.enumerators(), [](const EnumConstantDecl *ECD) { + return ECD->getInitExpr() == nullptr; + }); +} + +static bool isOnlyFirstEnumeratorInitialized(const EnumDecl &Node) { + bool IsFirst = true; + for (const EnumConstantDecl *ECD : Node.enumerators()) { + if ((IsFirst && ECD->getInitExpr() == nullptr) || + (!IsFirst && ECD->getInitExpr() != nullptr)) + return false; + IsFirst = false; + } + return !IsFirst; +} + +static bool areAllEnumeratorsInitialized(const EnumDecl &Node) { + return llvm::all_of(Node.enumerators(), [](const EnumConstantDecl *ECD) { + return ECD->getInitExpr() != nullptr; + }); +} + +/// Check if \p Enumerator is initialized with a (potentially negated) \c +/// IntegerLiteral. +static bool isInitializedByLiteral(const EnumConstantDecl *Enumerator) { + const Expr *const Init = Enumerator->getInitExpr(); + if (!Init) + return false; + return Init->isIntegerConstantExpr(Enumerator->getASTContext()); +} + +static void cleanInitialValue(DiagnosticBuilder &Diag, + const EnumConstantDecl *ECD, + const SourceManager &SM, + const LangOptions &LangOpts) { + std::optional<Token> EqualToken = utils::lexer::findNextTokenSkippingComments( + ECD->getLocation(), SM, LangOpts); + if (!EqualToken.has_value()) + return; + SourceLocation EqualLoc{EqualToken->getLocation()}; + if (EqualLoc.isInvalid() || EqualLoc.isMacroID()) + return; + SourceRange InitExprRange = ECD->getInitExpr()->getSourceRange(); + if (InitExprRange.isInvalid() || InitExprRange.getBegin().isMacroID() || + InitExprRange.getEnd().isMacroID()) + return; + Diag << FixItHint::CreateRemoval(EqualLoc) + << FixItHint::CreateRemoval(InitExprRange); + return; +} + +namespace { + +AST_MATCHER(EnumDecl, isMacro) { + SourceLocation Loc = Node.getBeginLoc(); + return Loc.isMacroID(); +} + +AST_MATCHER(EnumDecl, hasConsistentInitialValues) { + return isNoneEnumeratorsInitialized(Node) || + isOnlyFirstEnumeratorInitialized(Node) || + areAllEnumeratorsInitialized(Node); +} + +AST_MATCHER(EnumDecl, hasZeroInitialValueForFirstEnumerator) { + EnumDecl::enumerator_range Enumerators = Node.enumerators(); + if (Enumerators.empty()) + return false; + const EnumConstantDecl *ECD = *Enumerators.begin(); + return isOnlyFirstEnumeratorInitialized(Node) && + isInitializedByLiteral(ECD) && ECD->getInitVal().isZero(); +} + +/// Excludes bitfields because enumerators initialized with the result of a +/// bitwise operator on enumeration values or any other expr that is not a +/// potentially negative integer literal. +/// Enumerations where it is not directly clear if they are used with +/// bitmask, evident when enumerators are only initialized with (potentially +/// negative) integer literals, are ignored. This is also the case when all +/// enumerators are powers of two (e.g., 0, 1, 2). +AST_MATCHER(EnumDecl, hasSequentialInitialValues) { + EnumDecl::enumerator_range Enumerators = Node.enumerators(); + if (Enumerators.empty()) + return false; + const EnumConstantDecl *const FirstEnumerator = *Node.enumerator_begin(); + llvm::APSInt PrevValue = FirstEnumerator->getInitVal(); + if (!isInitializedByLiteral(FirstEnumerator)) + return false; + bool AllEnumeratorsArePowersOfTwo = true; + for (const EnumConstantDecl *Enumerator : llvm::drop_begin(Enumerators)) { + const llvm::APSInt NewValue = Enumerator->getInitVal(); + if (NewValue != ++PrevValue) + return false; + if (!isInitializedByLiteral(Enumerator)) + return false; + PrevValue = NewValue; + AllEnumeratorsArePowersOfTwo &= NewValue.isPowerOf2(); + } + return !AllEnumeratorsArePowersOfTwo; +} + +} // namespace + +EnumInitialValueCheck::EnumInitialValueCheck(StringRef Name, + ClangTidyContext *Context) + : ClangTidyCheck(Name, Context), + AllowExplicitZeroFirstInitialValue( + Options.get("AllowExplicitZeroFirstInitialValue", true)), + AllowExplicitSequentialInitialValues( + Options.get("AllowExplicitSequentialInitialValues", true)) {} + +void EnumInitialValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { + Options.store(Opts, "AllowExplicitZeroFirstInitialValue", + AllowExplicitZeroFirstInitialValue); + Options.store(Opts, "AllowExplicitSequentialInitialValues", + AllowExplicitSequentialInitialValues); +} + +void EnumInitialValueCheck::registerMatchers(MatchFinder *Finder) { + Finder->addMatcher( + enumDecl(unless(isMacro()), unless(hasConsistentInitialValues())) + .bind("inconsistent"), + this); + if (!AllowExplicitZeroFirstInitialValue) + Finder->addMatcher( + enumDecl(hasZeroInitialValueForFirstEnumerator()).bind("zero_first"), + this); + if (!AllowExplicitSequentialInitialValues) + Finder->addMatcher(enumDecl(unless(isMacro()), hasSequentialInitialValues()) + .bind("sequential"), + this); +} + +void EnumInitialValueCheck::check(const MatchFinder::MatchResult &Result) { + if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("inconsistent")) { + DiagnosticBuilder Diag = + diag(Enum->getBeginLoc(), + "inital values in enum %0 are not consistent, consider " + "explicit initialization first, all or none of enumerators") + << Enum; + for (const EnumConstantDecl *ECD : Enum->enumerators()) + if (ECD->getInitExpr() == nullptr) { + std::optional<Token> Next = utils::lexer::findNextTokenSkippingComments( + ECD->getLocation(), *Result.SourceManager, getLangOpts()); + if (!Next.has_value() || Next->getLocation().isMacroID()) + continue; ---------------- 5chmidti wrote:
I was about to suggest removing the `findNextTokenSkippingComments`, but it looks like the `EnumConstantDecl`s end loc is not actually saved (although I don't know how streaming its `SourceRange` into a diagnostic still underlines the whole word...). However, you could use `Lexer::getLocForEndOfToken(ECD->getLocation(), 0, *Result.SourceManager, getLangOpts())` instead, which looks to be cheaper than `findNextTokenSkippingComments`, from what I can tell from quickly skimming their function bodies. https://github.com/llvm/llvm-project/pull/86129 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
