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Diffstat (limited to 'compilerplugins/clang/store/simplifybool.cxx')
| -rw-r--r-- | compilerplugins/clang/store/simplifybool.cxx | 1333 |
1 files changed, 1333 insertions, 0 deletions
diff --git a/compilerplugins/clang/store/simplifybool.cxx b/compilerplugins/clang/store/simplifybool.cxx new file mode 100644 index 000000000..973ab6a7a --- /dev/null +++ b/compilerplugins/clang/store/simplifybool.cxx @@ -0,0 +1,1333 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#include <cassert> + +#include "plugin.hxx" +#include "clang/AST/CXXInheritance.h" + +namespace { + +// Like clang::Stmt::IgnoreImplicit (lib/AST/Stmt.cpp), but also looking through implicit +// UserDefinedConversion's member function call: +Expr const * ignoreAllImplicit(Expr const * expr) { + if (auto const e = dyn_cast<ExprWithCleanups>(expr)) { + expr = e->getSubExpr(); + } + if (auto const e = dyn_cast<MaterializeTemporaryExpr>(expr)) { + expr = e->getSubExpr(); + } + if (auto const e = dyn_cast<CXXBindTemporaryExpr>(expr)) { + expr = e->getSubExpr(); + } + while (auto const e = dyn_cast<ImplicitCastExpr>(expr)) { + expr = e->getSubExpr(); + if (e->getCastKind() == CK_UserDefinedConversion) { + auto const ce = cast<CXXMemberCallExpr>(expr); + assert(ce->getNumArgs() == 0); + expr = ce->getImplicitObjectArgument(); + } + } + return expr; +} + +Expr const * ignoreParenImpCastAndComma(Expr const * expr) { + for (;;) { + expr = expr->IgnoreParenImpCasts(); + auto e = dyn_cast<BinaryOperator>(expr); + if (e == nullptr || e->getOpcode() != BO_Comma) { + return expr; + } + expr = e->getRHS(); + } +} + +Expr const * getSubExprOfLogicalNegation(Expr const * expr) { + auto e = dyn_cast<UnaryOperator>(ignoreParenImpCastAndComma(expr)); + return e == nullptr || e->getOpcode() != UO_LNot + ? nullptr : e->getSubExpr(); +} + +clang::Type const * stripConstRef(clang::Type const * type) { + auto lvalueType = dyn_cast<LValueReferenceType>(type); + if (!lvalueType) + return type; + return lvalueType->getPointeeType()->getUnqualifiedDesugaredType(); +} + +bool isCompatibleTypeForOperator(clang::Type const * paramType, CXXRecordDecl const * argRecordDecl) { + paramType = stripConstRef(paramType); + auto paramRecordType = dyn_cast<RecordType>(paramType); + if (!paramRecordType) + return false; + CXXRecordDecl const * paramRecordDecl = dyn_cast<CXXRecordDecl>(paramRecordType->getDecl()); + if (!paramRecordDecl) + return false; + return argRecordDecl == paramRecordDecl || argRecordDecl->isDerivedFrom(paramRecordDecl); +} + +FunctionDecl const * findMemberOperator(CXXRecordDecl const * recordDecl, OverloadedOperatorKind ooOpcode, CXXRecordDecl const * rhs) { + for (auto it = recordDecl->method_begin(); it != recordDecl->method_end(); ++it) { + if (it->getOverloadedOperator() == ooOpcode) { + if (it->getNumParams() == 1 && isCompatibleTypeForOperator(it->getParamDecl(0)->getType().getTypePtr(), rhs)) + return *it; + } + } + return nullptr; +} + +// Magic value to indicate we assume this operator exists +static FunctionDecl const * const ASSUME_OPERATOR_EXISTS = reinterpret_cast<FunctionDecl const *>(-1); + +// Search for an operator with matching parameter types; while this may miss some operators with +// odd parameter types that would actually be used by the compiler, it is overall better to have too +// many false negatives (i.e., miss valid loplugin:simplifybool warnings) than false positives here: +FunctionDecl const * findOperator(CompilerInstance& compiler, BinaryOperator::Opcode opcode, clang::Type const * lhsType, clang::Type const * rhsType) { + auto lhsRecordType = dyn_cast<RecordType>(lhsType); + if (!lhsRecordType) + return nullptr; + auto rhsRecordType = dyn_cast<RecordType>(rhsType); + if (!rhsRecordType) + return nullptr; + CXXRecordDecl const * lhsRecordDecl = dyn_cast<CXXRecordDecl>(lhsRecordType->getDecl()); + if (!lhsRecordDecl) + return nullptr; + CXXRecordDecl const * rhsRecordDecl = dyn_cast<CXXRecordDecl>(rhsRecordType->getDecl()); + if (!rhsRecordDecl) + return nullptr; + + auto ctx = lhsRecordDecl->getCanonicalDecl()->getDeclContext(); + + /* + It looks the clang Sema::LookupOverloadedOperatorName is the chunk of functionality I need, + but I have no idea how to call it from here. + Actually finding the right standard library operators requires doing conversions and other funky stuff. + For now, just assume that standard library operators are well-behaved, and have negated operators. + */ + if (ctx->isStdNamespace()) + return ASSUME_OPERATOR_EXISTS; + if (auto namespaceDecl = dyn_cast<NamespaceDecl>(ctx)) { + // because, of course, half the standard library is not "in the standard namespace" + if (namespaceDecl->getName() == "__gnu_debug") + return ASSUME_OPERATOR_EXISTS; + } + + // search for member overloads + // (using the hard way here because DeclContext::lookup does not work for member operators) + auto ooOpcode = BinaryOperator::getOverloadedOperator(opcode); + FunctionDecl const * foundFunction = findMemberOperator(lhsRecordDecl, ooOpcode, rhsRecordDecl); + if (foundFunction) + return foundFunction; + auto ForallBasesCallback = [&](const CXXRecordDecl *baseCXXRecordDecl) + { + if (baseCXXRecordDecl->isInvalidDecl()) + return false; + foundFunction = findMemberOperator(baseCXXRecordDecl, ooOpcode, rhsRecordDecl); + return false; + }; + + lhsRecordDecl->forallBases(ForallBasesCallback); + if (foundFunction) + return foundFunction; + + // search for free function overloads + if (ctx->getDeclKind() == Decl::LinkageSpec) { + ctx = ctx->getParent(); + } + auto operatorDeclName = compiler.getASTContext().DeclarationNames.getCXXOperatorName(ooOpcode); + auto res = ctx->lookup(operatorDeclName); + for (auto d = res.begin(); d != res.end(); ++d) { + FunctionDecl const * f = dyn_cast<FunctionDecl>(*d); + if (!f || f->getNumParams() != 2) + continue; + if (!isCompatibleTypeForOperator(f->getParamDecl(0)->getType().getTypePtr(), lhsRecordDecl)) + continue; + if (!isCompatibleTypeForOperator(f->getParamDecl(1)->getType().getTypePtr(), rhsRecordDecl)) + continue; + return f; + } + return nullptr; +} + +enum class Value { Unknown, False, True }; + +Value getValue(Expr const * expr) { + expr = ignoreParenImpCastAndComma(expr); + if (expr->getType()->isBooleanType()) { + // Instead going via Expr::isCXX11ConstantExpr would turn up exactly one + // additional place in svx/source/dialog/framelinkarray.cxx + // + // const bool DIAG_DBL_CLIP_DEFAULT = false; + // ... + // ... = mxImpl.get() ? mxImpl->mbDiagDblClip : DIAG_DBL_CLIP_DEFAULT; + // + // where it is unclear whether it is not actually better to consider + // DIAG_DBL_CLIP_DEFAULT a tunable parameter (and thus not to simplify): + auto lit = dyn_cast<CXXBoolLiteralExpr>(expr); + if (lit != nullptr) { + return lit->getValue() ? Value::True : Value::False; + } + } + return Value::Unknown; +} + +class SimplifyBool: + public loplugin::FilteringPlugin<SimplifyBool> +{ +public: + explicit SimplifyBool(loplugin::InstantiationData const & data): + FilteringPlugin(data) {} + + void run() override; + + bool VisitUnaryOperator(UnaryOperator const * expr); + + bool VisitBinaryOperator(BinaryOperator const * expr); + + bool VisitConditionalOperator(ConditionalOperator const * expr); + + bool TraverseFunctionDecl(FunctionDecl *); + + bool TraverseCXXMethodDecl(CXXMethodDecl *); + +private: + bool visitBinLT(BinaryOperator const * expr); + + bool visitBinGT(BinaryOperator const * expr); + + bool visitBinLE(BinaryOperator const * expr); + + bool visitBinGE(BinaryOperator const * expr); + + bool visitBinEQ(BinaryOperator const * expr); + + bool visitBinNE(BinaryOperator const * expr); + + FunctionDecl* m_insideFunctionDecl = nullptr; +}; + +void SimplifyBool::run() { + if (compiler.getLangOpts().CPlusPlus) { + TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); + } +} + +bool SimplifyBool::VisitUnaryOperator(UnaryOperator const * expr) { + if (expr->getOpcode() != UO_LNot) { + return true; + } + if (ignoreLocation(expr)) { + return true; + } + auto e = getSubExprOfLogicalNegation(expr->getSubExpr()); + if (e) { + // Ignore macros, otherwise + // OSL_ENSURE(!b, ...); + // triggers. + if (e->getBeginLoc().isMacroID()) + return true; + // double logical not of an int is an idiom to convert to bool + auto const sub = ignoreAllImplicit(e); + if (!sub->getType()->isBooleanType()) + return true; + report( + DiagnosticsEngine::Warning, + ("double logical negation expression of the form '!!A' (with A of type" + " %0) can %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << sub->getType() + << sub->getType()->isBooleanType() + << expr->getSourceRange(); + return true; + } + auto sub = expr->getSubExpr()->IgnoreParenImpCasts(); + auto reversed = false; + if (auto const rewritten = dyn_cast<CXXRewrittenBinaryOperator>(sub)) { + if (rewritten->isReversed()) { + if (rewritten->getOperator() == BO_EQ) { + auto const sem = rewritten->getSemanticForm(); + bool match; + if (auto const op1 = dyn_cast<BinaryOperator>(sem)) { + match = op1->getOpcode() == BO_EQ; + } else if (auto const op2 = dyn_cast<CXXOperatorCallExpr>(sem)) { + match = op2->getOperator() == OO_EqualEqual; + } else { + match = false; + } + if (match) { + sub = sem; + reversed = true; + } + } + } + } + if (auto binaryOp = dyn_cast<BinaryOperator>(sub)) { + // Ignore macros, otherwise + // OSL_ENSURE(!b, ...); + // triggers. + if (binaryOp->getBeginLoc().isMacroID()) + return true; + if (binaryOp->isComparisonOp()) + { + auto t = binaryOp->getLHS()->IgnoreImpCasts()->getType()->getUnqualifiedDesugaredType(); + if (t->isTemplateTypeParmType() || t->isDependentType() || t->isRecordType()) + return true; + // for floating point (with NaN) !(x<y) need not be equivalent to x>=y + if (t->isFloatingType() || + binaryOp->getRHS()->IgnoreImpCasts()->getType()->getUnqualifiedDesugaredType()->isFloatingType()) + return true; + report( + DiagnosticsEngine::Warning, + ("logical negation of comparison operator, can be simplified by inverting operator"), + expr->getBeginLoc()) + << expr->getSourceRange(); + } + else if (binaryOp->isLogicalOp()) + { + // if we find a negation condition inside, it is definitely better + // to expand it out + bool foundLNot = false; + auto containsNegationOrComparison = [&](Expr const * expr) { + expr = ignoreParenImpCastAndComma(expr); + if (auto unaryOp = dyn_cast<UnaryOperator>(expr)) + if (unaryOp->getOpcode() == UO_LNot) + { + foundLNot = true; + return expr; + } + if (auto binaryOp = dyn_cast<BinaryOperator>(expr)) + if (binaryOp->isComparisonOp()) + return expr; + if (auto cxxOpCall = dyn_cast<CXXOperatorCallExpr>(expr)) + if (cxxOpCall->isComparisonOp()) + return expr; + return (Expr const*)nullptr; + }; + auto lhs = containsNegationOrComparison(binaryOp->getLHS()); + auto rhs = containsNegationOrComparison(binaryOp->getRHS()); + if (foundLNot || (lhs && rhs)) + report( + DiagnosticsEngine::Warning, + ("logical negation of logical op containing negation, can be simplified"), + binaryOp->getBeginLoc()) + << binaryOp->getSourceRange(); + } + } + if (auto binaryOp = dyn_cast<CXXOperatorCallExpr>(sub)) { + // Ignore macros, otherwise + // OSL_ENSURE(!b, ...); + // triggers. + if (binaryOp->getBeginLoc().isMacroID()) + return true; + auto op = binaryOp->getOperator(); + // Negating things like > and >= would probably not be wise, there is no guarantee the negation holds for operator overloaded types. + // However, == and != are normally considered ok. + if (!(op == OO_EqualEqual || op == OO_ExclaimEqual)) + return true; + BinaryOperator::Opcode negatedOpcode = BinaryOperator::negateComparisonOp(BinaryOperator::getOverloadedOpcode(op)); + auto lhs = binaryOp->getArg(reversed ? 1 : 0)->IgnoreImpCasts()->getType()->getUnqualifiedDesugaredType(); + auto rhs = binaryOp->getArg(reversed ? 0 : 1)->IgnoreImpCasts()->getType()->getUnqualifiedDesugaredType(); + auto const negOp = findOperator(compiler, negatedOpcode, lhs, rhs); + if (!negOp) + return true; + // if we are inside a similar operator, ignore, eg. operator!= is often defined by calling !operator== + if (m_insideFunctionDecl && m_insideFunctionDecl->getNumParams() >= 1) { + auto t = stripConstRef(m_insideFunctionDecl->getParamDecl(0)->getType().getTypePtr()); + if (t == lhs) + return true; + } + // QA code + StringRef fn(handler.getMainFileName()); + if (loplugin::isSamePathname(fn, SRCDIR "/testtools/source/bridgetest/bridgetest.cxx")) + return true; + report( + DiagnosticsEngine::Warning, + ("logical negation of comparison operator, can be simplified by inverting operator"), + expr->getBeginLoc()) + << expr->getSourceRange(); + if (negOp != ASSUME_OPERATOR_EXISTS) + report( + DiagnosticsEngine::Note, "the presumed corresponding negated operator for %0 and %1 is declared here", + negOp->getLocation()) + << binaryOp->getArg(reversed ? 1 : 0)->IgnoreImpCasts()->getType() + << binaryOp->getArg(reversed ? 0 : 1)->IgnoreImpCasts()->getType() + << negOp->getSourceRange(); + } + return true; +} + +bool SimplifyBool::VisitBinaryOperator(BinaryOperator const * expr) { + switch (expr->getOpcode()) { + case BO_LT: + return visitBinLT(expr); + case BO_GT: + return visitBinGT(expr); + case BO_LE: + return visitBinLE(expr); + case BO_GE: + return visitBinGE(expr); + case BO_EQ: + return visitBinEQ(expr); + case BO_NE: + return visitBinNE(expr); + default: + return true; + } +} + +bool SimplifyBool::visitBinLT(BinaryOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (!(expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + && expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType())) + { + return true; + } + auto v1 = getValue(expr->getLHS()); + auto v2 = getValue(expr->getRHS()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'A < false' (with A of type" + " %0) can logically be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::True: + { + auto e = getSubExprOfLogicalNegation(expr->getLHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'A < true' (with A" + " of type %0) can %select{logically|literally}1 be" + " simplified as '!A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << (expr->getLHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form '!A < true' (with A" + " of type %0) can %select{logically|literally}1 be" + " simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'false < A' (with A of type" + " %0) can %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'false < false' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'false < true' can" + " literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'true < A' (with A of type" + " %0) can logically be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'true < false' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("less-than expression of the form 'true < true' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::visitBinGT(BinaryOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (!(expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + && expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType())) + { + return true; + } + auto v1 = getValue(expr->getLHS()); + auto v2 = getValue(expr->getRHS()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'A > false' (with A of" + " type %0) can %select{logically|literally}1 be simplified as" + " 'A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'A > true' (with A of" + " type %0) can logically be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'false > A' (with A of" + " type %0) can logically be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'false > false' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'false > true' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + { + auto e = getSubExprOfLogicalNegation(expr->getRHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'true > A' (with" + " A of type %0) can %select{logically|literally}1 be" + " simplified as '!A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << (expr->getRHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'true > !A' (with" + " A of type %0) can %select{logically|literally}1 be" + " simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + case Value::False: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'true > false' can" + " literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("greater-than expression of the form 'true > true' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::visitBinLE(BinaryOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (!(expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + && expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType())) + { + return true; + } + auto v1 = getValue(expr->getLHS()); + auto v2 = getValue(expr->getRHS()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + { + auto e = getSubExprOfLogicalNegation(expr->getLHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'A <=" + " false' (with A of type %0) can" + " %select{logically|literally}1 be simplified as" + " '!A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << (expr->getLHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form '!A <=" + " false' (with A of type %0) can" + " %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + case Value::True: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'A <= true'" + " (with A of type %0) can logically be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'false <= A'" + " (with A of type %0) can logically be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'false <= false'" + " can literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'false <= true'" + " can literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'true <= A'" + " (with A of type %0) can %select{logically|literally}1 be" + " simplified as 'A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'true <= false'" + " can literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("less-than-or-equal-to expression of the form 'true <= true'" + " can literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::visitBinGE(BinaryOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (!(expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + && expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType())) + { + return true; + } + auto v1 = getValue(expr->getLHS()); + auto v2 = getValue(expr->getRHS()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'A >= false'" + " (with A of type %0) can logically be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'A >= true'" + " (with A of type %0) can %select{logically|literally}1 be" + " simplified as 'A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + { + auto e = getSubExprOfLogicalNegation(expr->getRHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form" + " 'false >= A' (with A of type %0) can" + " %select{logically|literally}1 be simplified as" + " '!A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << (expr->getRHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form" + " 'false >= !A' (with A of type %0) can" + " %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + case Value::False: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'false >=" + " false' can literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'false >=" + " true' can literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'true >= A'" + " (with A of type %0) can logically be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'true >=" + " false' can literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("greater-than-or-equal-to expression of the form 'true >=" + " true' can literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::visitBinEQ(BinaryOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (!(expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + && expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType())) + { + return true; + } + auto v1 = getValue(expr->getLHS()); + auto v2 = getValue(expr->getRHS()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + { + auto e = getSubExprOfLogicalNegation(expr->getLHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'A == false' (with A" + " of type %0) can %select{logically|literally}1 be" + " simplified as '!A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << (expr->getLHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form '!A == false' (with A" + " of type %0) can %select{logically|literally}1 be" + " simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + case Value::True: + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'A == true' (with A of type" + " %0) can %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + { + auto e = getSubExprOfLogicalNegation(expr->getRHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'false == A' (with A" + " of type %0) can %select{logically|literally}1 be" + " simplified as '!A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << (expr->getRHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'false == !A' (with A" + " of type %0) can %select{logically|literally}1 be" + " simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + case Value::False: + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'false == false' can" + " literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'false == true' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'true == A' (with A of type" + " %0) can %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'true == false' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("equal-to expression of the form 'true == true' can" + " literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::visitBinNE(BinaryOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (!(expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + && expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType())) + { + return true; + } + auto v1 = getValue(expr->getLHS()); + auto v2 = getValue(expr->getRHS()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'A != false' (with A of" + " type %0) can %select{logically|literally}1 be simplified as" + " 'A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << expr->getLHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::True: + { + auto e = getSubExprOfLogicalNegation(expr->getLHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'A != true' (with" + " A of type %0) can %select{logically|literally}1 be" + " simplified as '!A'"), + expr->getBeginLoc()) + << expr->getLHS()->IgnoreImpCasts()->getType() + << (expr->getLHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form '!A != true'" + " (with A of type %0) can" + " %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'false != A' (with A of" + " type %0) can %select{logically|literally}1 be simplified as" + " 'A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << expr->getRHS()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'false != false' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'false != true' can" + " literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + { + auto e = getSubExprOfLogicalNegation(expr->getRHS()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'true != A' (with" + " A of type %0) can %select{logically|literally}1 be" + " simplified as '!A'"), + expr->getBeginLoc()) + << expr->getRHS()->IgnoreImpCasts()->getType() + << (expr->getRHS()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'true != !A'" + " (with A of type %0) can" + " %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + case Value::False: + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'true != false' can" + " literally be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("not-equal-to expression of the form 'true != true' can" + " literally be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::VisitConditionalOperator(ConditionalOperator const * expr) { + if (ignoreLocation(expr)) { + return true; + } + auto v1 = getValue(expr->getTrueExpr()); + auto v2 = getValue(expr->getFalseExpr()); + switch (v1) { + case Value::Unknown: + switch (v2) { + case Value::Unknown: + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? B : false' (with A of" + " type %0 and B of type %1) can %select{logically|literally}2" + " be simplified as 'A && B'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getTrueExpr()->IgnoreImpCasts()->getType() + << ((expr->getCond()->IgnoreImpCasts()->getType() + ->isBooleanType()) + && (expr->getTrueExpr()->IgnoreImpCasts()->getType() + ->isBooleanType())) + << expr->getSourceRange(); + break; + case Value::True: + { + auto e = getSubExprOfLogicalNegation(expr->getCond()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? B : true'" + " (with A of type %0 and B of type %1) can" + " %select{logically|literally}2 be simplified as '!A" + " || B'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getTrueExpr()->IgnoreImpCasts()->getType() + << ((expr->getCond()->IgnoreImpCasts()->getType() + ->isBooleanType()) + && (expr->getTrueExpr()->IgnoreImpCasts()->getType() + ->isBooleanType())) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form '!A ? B : true'" + " (with A of type %0 and B of type %1) can" + " %select{logically|literally}2 be simplified as 'A ||" + " B'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << expr->getTrueExpr()->IgnoreImpCasts()->getType() + << (e->IgnoreImpCasts()->getType()->isBooleanType() + && (expr->getTrueExpr()->IgnoreImpCasts() + ->getType()->isBooleanType())) + << expr->getSourceRange(); + } + break; + } + } + break; + case Value::False: + switch (v2) { + case Value::Unknown: + { + auto e = getSubExprOfLogicalNegation(expr->getCond()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? false : B'" + " (with A of type %0 and B of type %1) can" + " %select{logically|literally}2 be simplified as '!A" + " && B'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getFalseExpr()->IgnoreImpCasts()->getType() + << ((expr->getCond()->IgnoreImpCasts()->getType() + ->isBooleanType()) + && (expr->getFalseExpr()->IgnoreImpCasts() + ->getType()->isBooleanType())) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form '!A ? false : B'" + " (with A of type %0 and B of type %1) can" + " %select{logically|literally}2 be simplified as 'A &&" + " B'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << expr->getFalseExpr()->IgnoreImpCasts()->getType() + << (e->IgnoreImpCasts()->getType()->isBooleanType() + && (expr->getFalseExpr()->IgnoreImpCasts() + ->getType()->isBooleanType())) + << expr->getSourceRange(); + } + break; + } + case Value::False: + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? false : false' (with" + " A of type %0) can logically be simplified as 'false'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + case Value::True: + { + auto e = getSubExprOfLogicalNegation(expr->getCond()); + if (e == nullptr) { + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? false : true'" + " (with A of type %0) can" + " %select{logically|literally}1 be simplified as" + " '!A'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << (expr->getCond()->IgnoreImpCasts()->getType() + ->isBooleanType()) + << expr->getSourceRange(); + } else { + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form '!A ? false :" + " true' (with A of type %0) can" + " %select{logically|literally}1 be simplified as 'A'"), + expr->getBeginLoc()) + << e->IgnoreImpCasts()->getType() + << e->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + } + break; + } + } + break; + case Value::True: + switch (v2) { + case Value::Unknown: + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? true : B' (with A of" + " type %0 and B of type %1) can %select{logically|literally}2" + " be simplified as 'A || B'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getFalseExpr()->IgnoreImpCasts()->getType() + << ((expr->getCond()->IgnoreImpCasts()->getType() + ->isBooleanType()) + && (expr->getFalseExpr()->IgnoreImpCasts()->getType() + ->isBooleanType())) + << expr->getSourceRange(); + break; + case Value::False: + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? true : false' (with A" + " of type %0) can %select{logically|literally}1 be simplified" + " as 'A'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getCond()->IgnoreImpCasts()->getType()->isBooleanType() + << expr->getSourceRange(); + break; + case Value::True: + report( + DiagnosticsEngine::Warning, + ("conditional expression of the form 'A ? true : true' (with A" + " of type %0) can logically be simplified as 'true'"), + expr->getBeginLoc()) + << expr->getCond()->IgnoreImpCasts()->getType() + << expr->getSourceRange(); + break; + } + break; + } + return true; +} + +bool SimplifyBool::TraverseFunctionDecl(FunctionDecl * functionDecl) { + auto copy = m_insideFunctionDecl; + m_insideFunctionDecl = functionDecl; + bool ret = RecursiveASTVisitor::TraverseFunctionDecl(functionDecl); + m_insideFunctionDecl = copy; + return ret; +} + +bool SimplifyBool::TraverseCXXMethodDecl(CXXMethodDecl * functionDecl) { + auto copy = m_insideFunctionDecl; + m_insideFunctionDecl = functionDecl; + bool ret = RecursiveASTVisitor::TraverseCXXMethodDecl(functionDecl); + m_insideFunctionDecl = copy; + return ret; +} + +loplugin::Plugin::Registration<SimplifyBool> X("simplifybool"); + +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |