================ @@ -0,0 +1,193 @@ +//===--- 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 { + +EnumInitialValueCheck::EnumInitialValueCheck(StringRef Name, + ClangTidyContext *Context) + : ClangTidyCheck(Name, Context), + AllowExplicitZeroFirstInitialValue( + Options.get("AllowExplicitZeroFirstInitialValue", true)), + AllowExplicitLinearInitialValues( + Options.get("AllowExplicitLinearInitialValues", true)) {} + +void EnumInitialValueCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) { + Options.store(Opts, "AllowExplicitZeroFirstInitialValue", + AllowExplicitZeroFirstInitialValue); + Options.store(Opts, "AllowExplicitLinearInitialValues", + AllowExplicitLinearInitialValues); +} + +namespace { + +bool isNoneEnumeratorsInitialized(const EnumDecl &Node) { + return llvm::all_of(Node.enumerators(), [](const EnumConstantDecl *ECD) { + return ECD->getInitExpr() == nullptr; + }); +} + +bool isOnlyFirstEnumeratorsInitialized(const EnumDecl &Node) { + bool IsFirst = true; + for (const EnumConstantDecl *ECD : Node.enumerators()) + if (IsFirst) { + IsFirst = false; + if (ECD->getInitExpr() == nullptr) + return false; + } else { + if (ECD->getInitExpr() != nullptr) + return false; + } + return !IsFirst; +} + +bool isAllEnumeratorsInitialized(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. +bool isInitializedByLiteral(const EnumConstantDecl *Enumerator) { + const Expr *const Init = Enumerator->getInitExpr(); + if (!Init) + return false; + return Init->isIntegerConstantExpr(Enumerator->getASTContext()); +} + +AST_MATCHER(EnumDecl, hasConsistentInitialValues) { + return isNoneEnumeratorsInitialized(Node) || + isOnlyFirstEnumeratorsInitialized(Node) || + isAllEnumeratorsInitialized(Node); +} + +AST_MATCHER(EnumDecl, hasZeroFirstInitialValue) { + if (Node.enumerators().empty()) + return false; + const EnumConstantDecl *ECD = *Node.enumerators().begin(); + return isOnlyFirstEnumeratorsInitialized(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, hasLinearInitialValues) { + if (Node.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(Node.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 + +void EnumInitialValueCheck::registerMatchers(MatchFinder *Finder) { + Finder->addMatcher( + enumDecl(unless(hasConsistentInitialValues())).bind("inconsistent"), + this); + if (!AllowExplicitZeroFirstInitialValue) + Finder->addMatcher(enumDecl(hasZeroFirstInitialValue()).bind("zero_first"), + this); + if (!AllowExplicitLinearInitialValues) + Finder->addMatcher(enumDecl(hasLinearInitialValues()).bind("linear"), this); +} + +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; +} + +void EnumInitialValueCheck::check(const MatchFinder::MatchResult &Result) { + if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("inconsistent")) { + SourceLocation Loc = Enum->getBeginLoc(); + if (Loc.isInvalid() || Loc.isMacroID()) + return; ---------------- PiotrZSL wrote:
Put this into AST matcher to avoid duplicates. 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
