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llvm-project/clang-tools-extra/clang-tidy/readability/SimplifyBooleanExprCheck.cpp

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//===--- SimplifyBooleanExpr.cpp clang-tidy ---------------------*- C++ -*-===//
//
// 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 "SimplifyBooleanExprCheck.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Lex/Lexer.h"
#include <cassert>
#include <string>
#include <utility>
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace readability {
namespace {
StringRef getText(const MatchFinder::MatchResult &Result, SourceRange Range) {
return Lexer::getSourceText(CharSourceRange::getTokenRange(Range),
*Result.SourceManager,
Result.Context->getLangOpts());
}
template <typename T>
StringRef getText(const MatchFinder::MatchResult &Result, T &Node) {
return getText(Result, Node.getSourceRange());
}
const char ConditionThenStmtId[] = "if-bool-yields-then";
const char ConditionElseStmtId[] = "if-bool-yields-else";
const char TernaryId[] = "ternary-bool-yields-condition";
const char TernaryNegatedId[] = "ternary-bool-yields-not-condition";
const char IfReturnsBoolId[] = "if-return";
const char IfReturnsNotBoolId[] = "if-not-return";
const char ThenLiteralId[] = "then-literal";
const char IfAssignVariableId[] = "if-assign-lvalue";
const char IfAssignLocId[] = "if-assign-loc";
const char IfAssignBoolId[] = "if-assign";
const char IfAssignNotBoolId[] = "if-assign-not";
const char IfAssignObjId[] = "if-assign-obj";
const char CompoundReturnId[] = "compound-return";
const char CompoundBoolId[] = "compound-bool";
const char CompoundNotBoolId[] = "compound-bool-not";
const char IfStmtId[] = "if";
const char SimplifyOperatorDiagnostic[] =
"redundant boolean literal supplied to boolean operator";
const char SimplifyConditionDiagnostic[] =
"redundant boolean literal in if statement condition";
const char SimplifyConditionalReturnDiagnostic[] =
"redundant boolean literal in conditional return statement";
const CXXBoolLiteralExpr *getBoolLiteral(const MatchFinder::MatchResult &Result,
StringRef Id) {
const auto *Literal = Result.Nodes.getNodeAs<CXXBoolLiteralExpr>(Id);
return (Literal && Literal->getBeginLoc().isMacroID()) ? nullptr : Literal;
}
internal::Matcher<Stmt> returnsBool(bool Value, StringRef Id = "ignored") {
auto SimpleReturnsBool =
returnStmt(has(cxxBoolLiteral(equals(Value)).bind(Id)))
.bind("returns-bool");
return anyOf(SimpleReturnsBool,
compoundStmt(statementCountIs(1), has(SimpleReturnsBool)));
}
bool needsParensAfterUnaryNegation(const Expr *E) {
E = E->IgnoreImpCasts();
if (isa<BinaryOperator>(E) || isa<ConditionalOperator>(E))
return true;
if (const auto *Op = dyn_cast<CXXOperatorCallExpr>(E))
return Op->getNumArgs() == 2 && Op->getOperator() != OO_Call &&
Op->getOperator() != OO_Subscript;
return false;
}
std::pair<BinaryOperatorKind, BinaryOperatorKind> Opposites[] = {
{BO_LT, BO_GE}, {BO_GT, BO_LE}, {BO_EQ, BO_NE}};
StringRef negatedOperator(const BinaryOperator *BinOp) {
const BinaryOperatorKind Opcode = BinOp->getOpcode();
for (auto NegatableOp : Opposites) {
if (Opcode == NegatableOp.first)
return BinOp->getOpcodeStr(NegatableOp.second);
if (Opcode == NegatableOp.second)
return BinOp->getOpcodeStr(NegatableOp.first);
}
return StringRef();
}
std::pair<OverloadedOperatorKind, StringRef> OperatorNames[] = {
{OO_EqualEqual, "=="}, {OO_ExclaimEqual, "!="}, {OO_Less, "<"},
{OO_GreaterEqual, ">="}, {OO_Greater, ">"}, {OO_LessEqual, "<="}};
StringRef getOperatorName(OverloadedOperatorKind OpKind) {
for (auto Name : OperatorNames) {
if (Name.first == OpKind)
return Name.second;
}
return StringRef();
}
std::pair<OverloadedOperatorKind, OverloadedOperatorKind> OppositeOverloads[] =
{{OO_EqualEqual, OO_ExclaimEqual},
{OO_Less, OO_GreaterEqual},
{OO_Greater, OO_LessEqual}};
StringRef negatedOperator(const CXXOperatorCallExpr *OpCall) {
const OverloadedOperatorKind Opcode = OpCall->getOperator();
for (auto NegatableOp : OppositeOverloads) {
if (Opcode == NegatableOp.first)
return getOperatorName(NegatableOp.second);
if (Opcode == NegatableOp.second)
return getOperatorName(NegatableOp.first);
}
return StringRef();
}
std::string asBool(StringRef text, bool NeedsStaticCast) {
if (NeedsStaticCast)
return ("static_cast<bool>(" + text + ")").str();
return text;
}
bool needsNullPtrComparison(const Expr *E) {
if (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E))
return ImpCast->getCastKind() == CK_PointerToBoolean ||
ImpCast->getCastKind() == CK_MemberPointerToBoolean;
return false;
}
bool needsZeroComparison(const Expr *E) {
if (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E))
return ImpCast->getCastKind() == CK_IntegralToBoolean;
return false;
}
bool needsStaticCast(const Expr *E) {
if (const auto *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
if (ImpCast->getCastKind() == CK_UserDefinedConversion &&
ImpCast->getSubExpr()->getType()->isBooleanType()) {
if (const auto *MemCall =
dyn_cast<CXXMemberCallExpr>(ImpCast->getSubExpr())) {
if (const auto *MemDecl =
dyn_cast<CXXConversionDecl>(MemCall->getMethodDecl())) {
if (MemDecl->isExplicit())
return true;
}
}
}
}
E = E->IgnoreImpCasts();
return !E->getType()->isBooleanType();
}
std::string compareExpressionToConstant(const MatchFinder::MatchResult &Result,
const Expr *E, bool Negated,
const char *Constant) {
E = E->IgnoreImpCasts();
const std::string ExprText =
(isa<BinaryOperator>(E) ? ("(" + getText(Result, *E) + ")")
: getText(Result, *E))
.str();
return ExprText + " " + (Negated ? "!=" : "==") + " " + Constant;
}
std::string compareExpressionToNullPtr(const MatchFinder::MatchResult &Result,
const Expr *E, bool Negated) {
const char *NullPtr =
Result.Context->getLangOpts().CPlusPlus11 ? "nullptr" : "NULL";
return compareExpressionToConstant(Result, E, Negated, NullPtr);
}
std::string compareExpressionToZero(const MatchFinder::MatchResult &Result,
const Expr *E, bool Negated) {
return compareExpressionToConstant(Result, E, Negated, "0");
}
std::string replacementExpression(const MatchFinder::MatchResult &Result,
bool Negated, const Expr *E) {
E = E->ignoreParenBaseCasts();
if (const auto *EC = dyn_cast<ExprWithCleanups>(E))
E = EC->getSubExpr();
const bool NeedsStaticCast = needsStaticCast(E);
if (Negated) {
if (const auto *UnOp = dyn_cast<UnaryOperator>(E)) {
if (UnOp->getOpcode() == UO_LNot) {
if (needsNullPtrComparison(UnOp->getSubExpr()))
return compareExpressionToNullPtr(Result, UnOp->getSubExpr(), true);
if (needsZeroComparison(UnOp->getSubExpr()))
return compareExpressionToZero(Result, UnOp->getSubExpr(), true);
return replacementExpression(Result, false, UnOp->getSubExpr());
}
}
if (needsNullPtrComparison(E))
return compareExpressionToNullPtr(Result, E, false);
if (needsZeroComparison(E))
return compareExpressionToZero(Result, E, false);
StringRef NegatedOperator;
const Expr *LHS = nullptr;
const Expr *RHS = nullptr;
if (const auto *BinOp = dyn_cast<BinaryOperator>(E)) {
NegatedOperator = negatedOperator(BinOp);
LHS = BinOp->getLHS();
RHS = BinOp->getRHS();
} else if (const auto *OpExpr = dyn_cast<CXXOperatorCallExpr>(E)) {
if (OpExpr->getNumArgs() == 2) {
NegatedOperator = negatedOperator(OpExpr);
LHS = OpExpr->getArg(0);
RHS = OpExpr->getArg(1);
}
}
if (!NegatedOperator.empty() && LHS && RHS)
return (asBool((getText(Result, *LHS) + " " + NegatedOperator + " " +
getText(Result, *RHS))
.str(),
NeedsStaticCast));
StringRef Text = getText(Result, *E);
if (!NeedsStaticCast && needsParensAfterUnaryNegation(E))
return ("!(" + Text + ")").str();
if (needsNullPtrComparison(E))
return compareExpressionToNullPtr(Result, E, false);
if (needsZeroComparison(E))
return compareExpressionToZero(Result, E, false);
return ("!" + asBool(Text, NeedsStaticCast));
}
if (const auto *UnOp = dyn_cast<UnaryOperator>(E)) {
if (UnOp->getOpcode() == UO_LNot) {
if (needsNullPtrComparison(UnOp->getSubExpr()))
return compareExpressionToNullPtr(Result, UnOp->getSubExpr(), false);
if (needsZeroComparison(UnOp->getSubExpr()))
return compareExpressionToZero(Result, UnOp->getSubExpr(), false);
}
}
if (needsNullPtrComparison(E))
return compareExpressionToNullPtr(Result, E, true);
if (needsZeroComparison(E))
return compareExpressionToZero(Result, E, true);
return asBool(getText(Result, *E), NeedsStaticCast);
}
const CXXBoolLiteralExpr *stmtReturnsBool(const ReturnStmt *Ret, bool Negated) {
if (const auto *Bool = dyn_cast<CXXBoolLiteralExpr>(Ret->getRetValue())) {
if (Bool->getValue() == !Negated)
return Bool;
}
return nullptr;
}
const CXXBoolLiteralExpr *stmtReturnsBool(const IfStmt *IfRet, bool Negated) {
if (IfRet->getElse() != nullptr)
return nullptr;
if (const auto *Ret = dyn_cast<ReturnStmt>(IfRet->getThen()))
return stmtReturnsBool(Ret, Negated);
if (const auto *Compound = dyn_cast<CompoundStmt>(IfRet->getThen())) {
if (Compound->size() == 1) {
if (const auto *CompoundRet = dyn_cast<ReturnStmt>(Compound->body_back()))
return stmtReturnsBool(CompoundRet, Negated);
}
}
return nullptr;
}
bool containsDiscardedTokens(const MatchFinder::MatchResult &Result,
CharSourceRange CharRange) {
std::string ReplacementText =
Lexer::getSourceText(CharRange, *Result.SourceManager,
Result.Context->getLangOpts())
.str();
Lexer Lex(CharRange.getBegin(), Result.Context->getLangOpts(),
ReplacementText.data(), ReplacementText.data(),
ReplacementText.data() + ReplacementText.size());
Lex.SetCommentRetentionState(true);
Token Tok;
while (!Lex.LexFromRawLexer(Tok)) {
if (Tok.is(tok::TokenKind::comment) || Tok.is(tok::TokenKind::hash))
return true;
}
return false;
}
} // namespace
class SimplifyBooleanExprCheck::Visitor : public RecursiveASTVisitor<Visitor> {
public:
Visitor(SimplifyBooleanExprCheck *Check,
const MatchFinder::MatchResult &Result)
: Check(Check), Result(Result) {}
bool VisitBinaryOperator(BinaryOperator *Op) {
Check->reportBinOp(Result, Op);
return true;
}
private:
SimplifyBooleanExprCheck *Check;
const MatchFinder::MatchResult &Result;
};
SimplifyBooleanExprCheck::SimplifyBooleanExprCheck(StringRef Name,
ClangTidyContext *Context)
: ClangTidyCheck(Name, Context),
ChainedConditionalReturn(Options.get("ChainedConditionalReturn", 0U)),
ChainedConditionalAssignment(
Options.get("ChainedConditionalAssignment", 0U)) {}
bool containsBoolLiteral(const Expr *E) {
if (!E)
return false;
E = E->IgnoreParenImpCasts();
if (isa<CXXBoolLiteralExpr>(E))
return true;
if (const auto *BinOp = dyn_cast<BinaryOperator>(E))
return containsBoolLiteral(BinOp->getLHS()) ||
containsBoolLiteral(BinOp->getRHS());
if (const auto *UnaryOp = dyn_cast<UnaryOperator>(E))
return containsBoolLiteral(UnaryOp->getSubExpr());
return false;
}
void SimplifyBooleanExprCheck::reportBinOp(
const MatchFinder::MatchResult &Result, const BinaryOperator *Op) {
const auto *LHS = Op->getLHS()->IgnoreParenImpCasts();
const auto *RHS = Op->getRHS()->IgnoreParenImpCasts();
const CXXBoolLiteralExpr *Bool = nullptr;
const Expr *Other = nullptr;
if ((Bool = dyn_cast<CXXBoolLiteralExpr>(LHS)))
Other = RHS;
else if ((Bool = dyn_cast<CXXBoolLiteralExpr>(RHS)))
Other = LHS;
else
return;
if (Bool->getBeginLoc().isMacroID())
return;
// FIXME: why do we need this?
if (!isa<CXXBoolLiteralExpr>(Other) && containsBoolLiteral(Other))
return;
bool BoolValue = Bool->getValue();
auto replaceWithExpression = [this, &Result, LHS, RHS, Bool](
const Expr *ReplaceWith, bool Negated) {
std::string Replacement =
replacementExpression(Result, Negated, ReplaceWith);
SourceRange Range(LHS->getBeginLoc(), RHS->getEndLoc());
issueDiag(Result, Bool->getBeginLoc(), SimplifyOperatorDiagnostic, Range,
Replacement);
};
switch (Op->getOpcode()) {
case BO_LAnd:
if (BoolValue) {
// expr && true -> expr
replaceWithExpression(Other, /*Negated=*/false);
} else {
// expr && false -> false
replaceWithExpression(Bool, /*Negated=*/false);
}
break;
case BO_LOr:
if (BoolValue) {
// expr || true -> true
replaceWithExpression(Bool, /*Negated=*/false);
} else {
// expr || false -> expr
replaceWithExpression(Other, /*Negated=*/false);
}
break;
case BO_EQ:
// expr == true -> expr, expr == false -> !expr
replaceWithExpression(Other, /*Negated=*/!BoolValue);
break;
case BO_NE:
// expr != true -> !expr, expr != false -> expr
replaceWithExpression(Other, /*Negated=*/BoolValue);
break;
default:
break;
}
}
void SimplifyBooleanExprCheck::matchBoolCondition(MatchFinder *Finder,
bool Value,
StringRef BooleanId) {
Finder->addMatcher(
ifStmt(isExpansionInMainFile(),
hasCondition(cxxBoolLiteral(equals(Value)).bind(BooleanId)))
.bind(IfStmtId),
this);
}
void SimplifyBooleanExprCheck::matchTernaryResult(MatchFinder *Finder,
bool Value,
StringRef TernaryId) {
Finder->addMatcher(
conditionalOperator(isExpansionInMainFile(),
hasTrueExpression(cxxBoolLiteral(equals(Value))),
hasFalseExpression(cxxBoolLiteral(equals(!Value))))
.bind(TernaryId),
this);
}
void SimplifyBooleanExprCheck::matchIfReturnsBool(MatchFinder *Finder,
bool Value, StringRef Id) {
if (ChainedConditionalReturn)
Finder->addMatcher(ifStmt(isExpansionInMainFile(),
hasThen(returnsBool(Value, ThenLiteralId)),
hasElse(returnsBool(!Value)))
.bind(Id),
this);
else
Finder->addMatcher(ifStmt(isExpansionInMainFile(),
unless(hasParent(ifStmt())),
hasThen(returnsBool(Value, ThenLiteralId)),
hasElse(returnsBool(!Value)))
.bind(Id),
this);
}
void SimplifyBooleanExprCheck::matchIfAssignsBool(MatchFinder *Finder,
bool Value, StringRef Id) {
auto SimpleThen = binaryOperator(
hasOperatorName("="),
hasLHS(declRefExpr(hasDeclaration(decl().bind(IfAssignObjId)))),
hasLHS(expr().bind(IfAssignVariableId)),
hasRHS(cxxBoolLiteral(equals(Value)).bind(IfAssignLocId)));
auto Then = anyOf(SimpleThen, compoundStmt(statementCountIs(1),
hasAnySubstatement(SimpleThen)));
auto SimpleElse = binaryOperator(
hasOperatorName("="),
hasLHS(declRefExpr(hasDeclaration(equalsBoundNode(IfAssignObjId)))),
hasRHS(cxxBoolLiteral(equals(!Value))));
auto Else = anyOf(SimpleElse, compoundStmt(statementCountIs(1),
hasAnySubstatement(SimpleElse)));
if (ChainedConditionalAssignment)
Finder->addMatcher(
ifStmt(isExpansionInMainFile(), hasThen(Then), hasElse(Else)).bind(Id),
this);
else
Finder->addMatcher(ifStmt(isExpansionInMainFile(),
unless(hasParent(ifStmt())), hasThen(Then),
hasElse(Else))
.bind(Id),
this);
}
void SimplifyBooleanExprCheck::matchCompoundIfReturnsBool(MatchFinder *Finder,
bool Value,
StringRef Id) {
Finder->addMatcher(
compoundStmt(
hasAnySubstatement(
ifStmt(hasThen(returnsBool(Value)), unless(hasElse(stmt())))),
hasAnySubstatement(returnStmt(has(ignoringParenImpCasts(
cxxBoolLiteral(equals(!Value)))))
.bind(CompoundReturnId)))
.bind(Id),
this);
}
void SimplifyBooleanExprCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
Options.store(Opts, "ChainedConditionalReturn", ChainedConditionalReturn);
Options.store(Opts, "ChainedConditionalAssignment",
ChainedConditionalAssignment);
}
void SimplifyBooleanExprCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(translationUnitDecl().bind("top"), this);
matchBoolCondition(Finder, true, ConditionThenStmtId);
matchBoolCondition(Finder, false, ConditionElseStmtId);
matchTernaryResult(Finder, true, TernaryId);
matchTernaryResult(Finder, false, TernaryNegatedId);
matchIfReturnsBool(Finder, true, IfReturnsBoolId);
matchIfReturnsBool(Finder, false, IfReturnsNotBoolId);
matchIfAssignsBool(Finder, true, IfAssignBoolId);
matchIfAssignsBool(Finder, false, IfAssignNotBoolId);
matchCompoundIfReturnsBool(Finder, true, CompoundBoolId);
matchCompoundIfReturnsBool(Finder, false, CompoundNotBoolId);
}
void SimplifyBooleanExprCheck::check(const MatchFinder::MatchResult &Result) {
if (Result.Nodes.getNodeAs<TranslationUnitDecl>("top"))
Visitor(this, Result).TraverseAST(*Result.Context);
else if (const CXXBoolLiteralExpr *TrueConditionRemoved =
getBoolLiteral(Result, ConditionThenStmtId))
replaceWithThenStatement(Result, TrueConditionRemoved);
else if (const CXXBoolLiteralExpr *FalseConditionRemoved =
getBoolLiteral(Result, ConditionElseStmtId))
replaceWithElseStatement(Result, FalseConditionRemoved);
else if (const auto *Ternary =
Result.Nodes.getNodeAs<ConditionalOperator>(TernaryId))
replaceWithCondition(Result, Ternary);
else if (const auto *TernaryNegated =
Result.Nodes.getNodeAs<ConditionalOperator>(TernaryNegatedId))
replaceWithCondition(Result, TernaryNegated, true);
else if (const auto *If = Result.Nodes.getNodeAs<IfStmt>(IfReturnsBoolId))
replaceWithReturnCondition(Result, If);
else if (const auto *IfNot =
Result.Nodes.getNodeAs<IfStmt>(IfReturnsNotBoolId))
replaceWithReturnCondition(Result, IfNot, true);
else if (const auto *IfAssign =
Result.Nodes.getNodeAs<IfStmt>(IfAssignBoolId))
replaceWithAssignment(Result, IfAssign);
else if (const auto *IfAssignNot =
Result.Nodes.getNodeAs<IfStmt>(IfAssignNotBoolId))
replaceWithAssignment(Result, IfAssignNot, true);
else if (const auto *Compound =
Result.Nodes.getNodeAs<CompoundStmt>(CompoundBoolId))
replaceCompoundReturnWithCondition(Result, Compound);
else if (const auto *Compound =
Result.Nodes.getNodeAs<CompoundStmt>(CompoundNotBoolId))
replaceCompoundReturnWithCondition(Result, Compound, true);
}
void SimplifyBooleanExprCheck::issueDiag(
const ast_matchers::MatchFinder::MatchResult &Result, SourceLocation Loc,
StringRef Description, SourceRange ReplacementRange,
StringRef Replacement) {
CharSourceRange CharRange =
Lexer::makeFileCharRange(CharSourceRange::getTokenRange(ReplacementRange),
*Result.SourceManager, getLangOpts());
DiagnosticBuilder Diag = diag(Loc, Description);
if (!containsDiscardedTokens(Result, CharRange))
Diag << FixItHint::CreateReplacement(CharRange, Replacement);
}
void SimplifyBooleanExprCheck::replaceWithThenStatement(
const MatchFinder::MatchResult &Result,
const CXXBoolLiteralExpr *TrueConditionRemoved) {
const auto *IfStatement = Result.Nodes.getNodeAs<IfStmt>(IfStmtId);
issueDiag(Result, TrueConditionRemoved->getBeginLoc(),
SimplifyConditionDiagnostic, IfStatement->getSourceRange(),
getText(Result, *IfStatement->getThen()));
}
void SimplifyBooleanExprCheck::replaceWithElseStatement(
const MatchFinder::MatchResult &Result,
const CXXBoolLiteralExpr *FalseConditionRemoved) {
const auto *IfStatement = Result.Nodes.getNodeAs<IfStmt>(IfStmtId);
const Stmt *ElseStatement = IfStatement->getElse();
issueDiag(Result, FalseConditionRemoved->getBeginLoc(),
SimplifyConditionDiagnostic, IfStatement->getSourceRange(),
ElseStatement ? getText(Result, *ElseStatement) : "");
}
void SimplifyBooleanExprCheck::replaceWithCondition(
const MatchFinder::MatchResult &Result, const ConditionalOperator *Ternary,
bool Negated) {
std::string Replacement =
replacementExpression(Result, Negated, Ternary->getCond());
issueDiag(Result, Ternary->getTrueExpr()->getBeginLoc(),
"redundant boolean literal in ternary expression result",
Ternary->getSourceRange(), Replacement);
}
void SimplifyBooleanExprCheck::replaceWithReturnCondition(
const MatchFinder::MatchResult &Result, const IfStmt *If, bool Negated) {
StringRef Terminator = isa<CompoundStmt>(If->getElse()) ? ";" : "";
std::string Condition = replacementExpression(Result, Negated, If->getCond());
std::string Replacement = ("return " + Condition + Terminator).str();
SourceLocation Start =
Result.Nodes.getNodeAs<CXXBoolLiteralExpr>(ThenLiteralId)->getBeginLoc();
issueDiag(Result, Start, SimplifyConditionalReturnDiagnostic,
If->getSourceRange(), Replacement);
}
void SimplifyBooleanExprCheck::replaceCompoundReturnWithCondition(
const MatchFinder::MatchResult &Result, const CompoundStmt *Compound,
bool Negated) {
const auto *Ret = Result.Nodes.getNodeAs<ReturnStmt>(CompoundReturnId);
// The body shouldn't be empty because the matcher ensures that it must
// contain at least two statements:
// 1) A `return` statement returning a boolean literal `false` or `true`
// 2) An `if` statement with no `else` clause that consists of a single
// `return` statement returning the opposite boolean literal `true` or
// `false`.
assert(Compound->size() >= 2);
const IfStmt *BeforeIf = nullptr;
CompoundStmt::const_body_iterator Current = Compound->body_begin();
CompoundStmt::const_body_iterator After = Compound->body_begin();
for (++After; After != Compound->body_end() && *Current != Ret;
++Current, ++After) {
if (const auto *If = dyn_cast<IfStmt>(*Current)) {
if (const CXXBoolLiteralExpr *Lit = stmtReturnsBool(If, Negated)) {
if (*After == Ret) {
if (!ChainedConditionalReturn && BeforeIf)
continue;
const Expr *Condition = If->getCond();
std::string Replacement =
"return " + replacementExpression(Result, Negated, Condition);
issueDiag(
Result, Lit->getBeginLoc(), SimplifyConditionalReturnDiagnostic,
SourceRange(If->getBeginLoc(), Ret->getEndLoc()), Replacement);
return;
}
BeforeIf = If;
}
} else {
BeforeIf = nullptr;
}
}
}
void SimplifyBooleanExprCheck::replaceWithAssignment(
const MatchFinder::MatchResult &Result, const IfStmt *IfAssign,
bool Negated) {
SourceRange Range = IfAssign->getSourceRange();
StringRef VariableName =
getText(Result, *Result.Nodes.getNodeAs<Expr>(IfAssignVariableId));
StringRef Terminator = isa<CompoundStmt>(IfAssign->getElse()) ? ";" : "";
std::string Condition =
replacementExpression(Result, Negated, IfAssign->getCond());
std::string Replacement =
(VariableName + " = " + Condition + Terminator).str();
SourceLocation Location =
Result.Nodes.getNodeAs<CXXBoolLiteralExpr>(IfAssignLocId)->getBeginLoc();
issueDiag(Result, Location,
"redundant boolean literal in conditional assignment", Range,
Replacement);
}
} // namespace readability
} // namespace tidy
} // namespace clang
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