================ @@ -0,0 +1,646 @@ +//===--- RedundantNestedIfCheck.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 "RedundantNestedIfCheck.h" +#include "../utils/LexerUtils.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/DeclTemplate.h" +#include "clang/AST/Stmt.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/Basic/Diagnostic.h" +#include "clang/Lex/Lexer.h" +#include "clang/Tooling/FixIt.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallVector.h" +#include <cassert> +#include <optional> +#include <string> +#include <vector> + +using namespace clang::ast_matchers; + +namespace clang::tidy::readability { + +static constexpr llvm::StringLiteral AllowUserDefinedBoolConversionStr = + "AllowUserDefinedBoolConversion"; +static constexpr llvm::StringLiteral MergeableIfDiag = + "nested if statements can be merged"; +static constexpr llvm::StringLiteral NestedIfNote = + "nested if statement to merge is here"; + +namespace { + +using IfChain = llvm::SmallVector<const IfStmt *>; + +enum class ChainHandling { + None, + WarnOnly, + WarnAndFix, +}; + +enum class CombinedConditionBuildStatus { + Success, + UnsupportedCommentPlacement, + Failure, +}; + +struct CombinedConditionBuildResult { + CombinedConditionBuildStatus Status = CombinedConditionBuildStatus::Failure; + std::string Text; +}; + +} // namespace + +// Conjoining conditions with `&&` can change behavior when a condition relies +// on contextual user-defined conversion to `bool`. +static bool containsUserDefinedBoolConversion(const Expr *Expression) { + assert(Expression); + + if (const auto *Cast = dyn_cast<ImplicitCastExpr>(Expression); + Cast && Cast->getCastKind() == CK_UserDefinedConversion) + return true; + + return llvm::any_of(Expression->children(), [](const Stmt *Child) { + const auto *ChildExpr = dyn_cast_or_null<Expr>(Child); + return ChildExpr && containsUserDefinedBoolConversion(ChildExpr); + }); +} + +static bool conditionNeedsBoolCast(const Expr *Condition) { + assert(Condition); + + if (!containsUserDefinedBoolConversion(Condition)) + return false; + + const Expr *const Unwrapped = + Condition->IgnoreImplicitAsWritten()->IgnoreParens(); + if (!Unwrapped) + return true; + + const QualType ConditionType = Unwrapped->getType(); + return ConditionType.isNull() || !ConditionType->isScalarType(); +} + +static bool +isConditionExpressionMergeable(const Expr *Condition, + bool AllowUserDefinedBoolConversion) { + assert(Condition); + + if (Condition->isTypeDependent()) + return false; + + if (containsUserDefinedBoolConversion(Condition)) + return AllowUserDefinedBoolConversion; + + const Expr *const Unwrapped = Condition->IgnoreParenImpCasts(); + if (!Unwrapped) + return false; + + const QualType ConditionType = Unwrapped->getType(); + return !ConditionType.isNull() && ConditionType->isScalarType(); +} + +static std::optional<CharSourceRange> +getIfConditionRange(const IfStmt *If, const SourceManager &SM, + const LangOptions &LangOpts) { + assert(If); + + const SourceLocation ConditionBegin = + Lexer::getLocForEndOfToken(If->getLParenLoc(), 0, SM, LangOpts); + if (ConditionBegin.isInvalid() || If->getRParenLoc().isInvalid()) + return std::nullopt; + + const CharSourceRange ConditionRange = + CharSourceRange::getCharRange(ConditionBegin, If->getRParenLoc()); + const CharSourceRange FileRange = + Lexer::makeFileCharRange(ConditionRange, SM, LangOpts); + if (FileRange.isInvalid()) + return std::nullopt; + + return FileRange; +} + +static std::optional<std::string> +getIfConditionText(const IfStmt *If, const SourceManager &SM, + const LangOptions &LangOpts) { + const std::optional<CharSourceRange> ConditionRange = + getIfConditionRange(If, SM, LangOpts); + if (!ConditionRange) + return std::nullopt; + + bool Invalid = false; + const StringRef ConditionText = + Lexer::getSourceText(*ConditionRange, SM, LangOpts, &Invalid); + return Invalid || ConditionText.empty() + ? std::nullopt + : std::optional<std::string>(ConditionText.str()); +} + +static bool isLocationInCharRange(SourceLocation Loc, CharSourceRange Range, + const SourceManager &SM) { + return Loc.isValid() && Range.isValid() && + !SM.isBeforeInTranslationUnit(Loc, Range.getBegin()) && + SM.isBeforeInTranslationUnit(Loc, Range.getEnd()); +} + +// Keep fix-its only when comments in removed nested headers stay inside the +// preserved condition text. Other comment placements keep the diagnostic but +// suppress the rewrite. +static bool hasOnlyPayloadCommentsInNestedHeader(const IfStmt *Nested, + const SourceManager &SM, + const LangOptions &LangOpts) { + assert(Nested); + + const CharSourceRange HeaderRange = CharSourceRange::getCharRange( + Nested->getBeginLoc(), Nested->getThen()->getBeginLoc()); + const CharSourceRange HeaderFileRange = + Lexer::makeFileCharRange(HeaderRange, SM, LangOpts); ---------------- vbvictor wrote:
Ditto https://github.com/llvm/llvm-project/pull/181558 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
