From ed5640d8b587fbcfed7dd7967f3de04b37a76f26 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 11:06:44 +0200 Subject: Adding upstream version 4:7.4.7. Signed-off-by: Daniel Baumann --- compilerplugins/clang/casttovoid.cxx | 535 +++++++++++++++++++++++++++++++++++ 1 file changed, 535 insertions(+) create mode 100644 compilerplugins/clang/casttovoid.cxx (limited to 'compilerplugins/clang/casttovoid.cxx') diff --git a/compilerplugins/clang/casttovoid.cxx b/compilerplugins/clang/casttovoid.cxx new file mode 100644 index 000000000..bddfcb4da --- /dev/null +++ b/compilerplugins/clang/casttovoid.cxx @@ -0,0 +1,535 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */ +/* + * 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 +#include +#include +#include + +#include "clang/AST/Attr.h" + +#include "check.hxx" +#include "plugin.hxx" + +namespace { + +bool isWarnUnusedType(QualType type) { + if (auto const t = type->getAs()) { + if (t->getDecl()->hasAttr()) { + return true; + } + } + if (auto const t = type->getAs()) { + if (t->getDecl()->hasAttr()) { + return true; + } + } + return loplugin::isExtraWarnUnusedType(type); +} + +Expr const * lookThroughInitListExpr(Expr const * expr) { + if (auto const ile = dyn_cast(expr->IgnoreParenImpCasts())) { + if (ile->getNumInits() == 1) { + return ile->getInit(0); + } + } + return expr; +} + +class CastToVoid final: + public loplugin::FilteringPlugin +{ +public: + explicit CastToVoid(loplugin::InstantiationData const & data): + FilteringPlugin(data) {} + + bool TraverseCStyleCastExpr(CStyleCastExpr * expr) { + auto const dre = checkCast(expr); + if (dre != nullptr) { + castToVoid_.push({expr, dre}); + } + auto const ret = RecursiveASTVisitor::TraverseCStyleCastExpr(expr); + if (dre != nullptr) { + assert(!castToVoid_.empty()); + assert(castToVoid_.top().cast == expr); + assert(castToVoid_.top().sub == dre); + castToVoid_.pop(); + } + return ret; + } + + bool TraverseCXXStaticCastExpr(CXXStaticCastExpr * expr) { + auto const dre = checkCast(expr); + if (dre != nullptr) { + castToVoid_.push({expr, dre}); + } + auto const ret = RecursiveASTVisitor::TraverseCXXStaticCastExpr(expr); + if (dre != nullptr) { + assert(!castToVoid_.empty()); + assert(castToVoid_.top().cast == expr); + assert(castToVoid_.top().sub == dre); + castToVoid_.pop(); + } + return ret; + } + + bool TraverseCXXFunctionalCastExpr(CXXFunctionalCastExpr * expr) { + auto const dre = checkCast(expr); + if (dre != nullptr) { + castToVoid_.push({expr, dre}); + } + auto const ret = RecursiveASTVisitor::TraverseCXXFunctionalCastExpr( + expr); + if (dre != nullptr) { + assert(!castToVoid_.empty()); + assert(castToVoid_.top().cast == expr); + assert(castToVoid_.top().sub == dre); + castToVoid_.pop(); + } + return ret; + } + + bool TraverseFunctionDecl(FunctionDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseFunctionDecl(decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseCXXDeductionGuideDecl(CXXDeductionGuideDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseCXXDeductionGuideDecl( + decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseCXXMethodDecl(CXXMethodDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseCXXMethodDecl(decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseCXXConstructorDecl(CXXConstructorDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseCXXConstructorDecl(decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseCXXDestructorDecl(CXXDestructorDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseCXXDestructorDecl(decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseCXXConversionDecl(CXXConversionDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseCXXConversionDecl(decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseObjCMethodDecl(ObjCMethodDecl * decl) { + returnTypes_.push(decl->getReturnType()); + auto const ret = RecursiveASTVisitor::TraverseObjCMethodDecl(decl); + assert(!returnTypes_.empty()); + assert(returnTypes_.top() == decl->getReturnType()); + returnTypes_.pop(); + return ret; + } + + bool TraverseConstructorInitializer(CXXCtorInitializer * init) { + if (auto const field = init->getAnyMember()) { + if (loplugin::TypeCheck(field->getType()).LvalueReference()) { + recordConsumption(lookThroughInitListExpr(init->getInit())); + } + } + return RecursiveASTVisitor::TraverseConstructorInitializer(init); + } + + bool TraverseLambdaExpr(LambdaExpr * expr, DataRecursionQueue * queue = nullptr) { + if (!shouldTraversePostOrder()) { + if (!WalkUpFromLambdaExpr(expr)) { + return false; + } + } + auto const n = expr->capture_size(); + for (unsigned i = 0; i != n; ++i) { + auto const c = expr->capture_begin() + i; + if (c->isExplicit() || shouldVisitImplicitCode()) { + if (!TraverseLambdaCapture(expr, c, expr->capture_init_begin()[i])) { + return false; + } + } + } + if (!TraverseCXXRecordDecl(expr->getLambdaClass())) { + return false; + } + if (!queue && shouldTraversePostOrder()) { + if (!WalkUpFromLambdaExpr(expr)) { + return false; + } + } + return true; + } + + bool VisitDeclRefExpr(DeclRefExpr const * expr) { + if (ignoreLocation(expr)) { + return true; + } + auto const var = dyn_cast(expr->getDecl()); + if (var == nullptr) { + return true; + } + if (var->getType().isVolatileQualified()) { + return true; + } + auto & usage = vars_[var->getCanonicalDecl()]; + if (!castToVoid_.empty() && castToVoid_.top().sub == expr) { + usage.castToVoid.push_back(castToVoid_.top().cast); + } else { + usage.mentioned = true; + } + return true; + } + + bool VisitImplicitCastExpr(ImplicitCastExpr const * expr) { + if (ignoreLocation(expr)) { + return true; + } + if (expr->getCastKind() != CK_LValueToRValue) { + return true; + } + recordConsumption(expr->getSubExpr()); + return true; + } + + bool VisitCallExpr(CallExpr const * expr) { + if (ignoreLocation(expr)) { + return true; + } + unsigned firstArg = 0; + if (auto const cmce = dyn_cast(expr)) { + if (auto const e1 = cmce->getMethodDecl()) { + if (e1->isConst() || e1->isStatic()) { + recordConsumption(cmce->getImplicitObjectArgument()); + } + } else if (auto const e2 = dyn_cast( + cmce->getCallee()->IgnoreParenImpCasts())) + { + switch (e2->getOpcode()) { + case BO_PtrMemD: + case BO_PtrMemI: + if (e2->getRHS()->getType()->getAs() + ->getPointeeType()->getAs() + ->isConst()) + { + recordConsumption(e2->getLHS()); + } + break; + default: + break; + } + } + } else if (isa(expr)) { + if (auto const cmd = dyn_cast_or_null( + expr->getDirectCallee())) + { + if (!cmd->isStatic()) { + assert(expr->getNumArgs() != 0); + if (cmd->isConst()) { + recordConsumption(expr->getArg(0)); + } + firstArg = 1; + } + } + } + auto fun = expr->getDirectCallee(); + if (fun == nullptr) { + return true; + } + unsigned const n = std::min(fun->getNumParams(), expr->getNumArgs()); + for (unsigned i = firstArg; i < n; ++i) { + if (!loplugin::TypeCheck(fun->getParamDecl(i)->getType()) + .LvalueReference().Const()) + { + continue; + } + recordConsumption(lookThroughInitListExpr(expr->getArg(i))); + } + return true; + } + + bool VisitCXXConstructExpr(CXXConstructExpr const * expr) { + if (ignoreLocation(expr)) { + return true; + } + auto const ctor = expr->getConstructor(); + unsigned const n = std::min(ctor->getNumParams(), expr->getNumArgs()); + for (unsigned i = 0; i != n; ++i) { + if (!loplugin::TypeCheck(ctor->getParamDecl(i)->getType()) + .LvalueReference().Const()) + { + continue; + } + recordConsumption(lookThroughInitListExpr(expr->getArg(i))); + } + return true; + } + + bool VisitReturnStmt(ReturnStmt const * stmt) { + if (ignoreLocation(stmt)) { + return true; + } + assert(!returnTypes_.empty()); + if (!loplugin::TypeCheck(returnTypes_.top()).LvalueReference().Const()) + { + return true; + } + auto const ret = stmt->getRetValue(); + if (ret == nullptr) { + return true; + } + recordConsumption(lookThroughInitListExpr(ret)); + return true; + } + + bool VisitVarDecl(VarDecl const * decl) { + if (ignoreLocation(decl)) { + return true; + } + if (!loplugin::TypeCheck(decl->getType()).LvalueReference()) { + return true; + } + auto const init = decl->getInit(); + if (init == nullptr) { + return true; + } + recordConsumption(lookThroughInitListExpr(init)); + return true; + } + + bool VisitFieldDecl(FieldDecl const * decl) { + if (ignoreLocation(decl)) { + return true; + } + if (!loplugin::TypeCheck(decl->getType()).LvalueReference()) { + return true; + } + auto const init = decl->getInClassInitializer(); + if (init == nullptr) { + return true; + } + recordConsumption(lookThroughInitListExpr(init)); + return true; + } + +private: + struct Usage { + std::vector castToVoid; + bool mentioned = false; + DeclRefExpr const * firstConsumption = nullptr; + }; + + struct Cast { + ExplicitCastExpr const * cast; + DeclRefExpr const * sub; + }; + + std::map vars_; + std::stack castToVoid_; + std::stack returnTypes_; + + void run() override { + if (compiler.getPreprocessor().getIdentifierInfo("NDEBUG")->hasMacroDefinition()) { + return; + } + if (!TraverseDecl(compiler.getASTContext().getTranslationUnitDecl())) { + return; + } + for (auto const & i: vars_) { + if (i.second.firstConsumption == nullptr) { + if (i.second.mentioned) { + continue; + } + if (isa(i.first)) { + if (!compiler.getLangOpts().CPlusPlus + || isSharedCAndCppCode(i.first)) + { + continue; + } + auto const ctxt = i.first->getDeclContext(); + if (dyn_cast_or_null(ctxt) != nullptr) { + continue; + } + auto const fun = dyn_cast_or_null(ctxt); + assert(fun != nullptr); + if (containsPreprocessingConditionalInclusion( + fun->getSourceRange())) + { + continue; + } + auto const meth = dyn_cast(fun); + report( + DiagnosticsEngine::Warning, + "unused%select{| virtual function}0 parameter name", + i.first->getLocation()) + << (meth != nullptr && meth->isVirtual()) + << i.first->getSourceRange(); + for (auto const j: i.second.castToVoid) { + report( + DiagnosticsEngine::Note, "cast to void here", + j->getExprLoc()) + << j->getSourceRange(); + } + } else if (!i.second.castToVoid.empty() + && !isWarnUnusedType(i.first->getType())) + { + auto const fun = dyn_cast_or_null(i.first->getDeclContext()); + assert(fun != nullptr); + if (containsPreprocessingConditionalInclusion(fun->getSourceRange())) { + continue; + } + report( + DiagnosticsEngine::Warning, + "unused variable %select{declaration|name}0", + i.first->getLocation()) + << i.first->isExceptionVariable() + << i.first->getSourceRange(); + for (auto const j: i.second.castToVoid) { + report( + DiagnosticsEngine::Note, "cast to void here", + j->getExprLoc()) + << j->getSourceRange(); + } + } + } else { + for (auto const j: i.second.castToVoid) { + report( + DiagnosticsEngine::Warning, "unnecessary cast to void", + j->getExprLoc()) + << j->getSourceRange(); + report( + DiagnosticsEngine::Note, "first consumption is here", + i.second.firstConsumption->getExprLoc()) + << i.second.firstConsumption->getSourceRange(); + } + } + } + } + + bool isFromCIncludeFile(SourceLocation spellingLocation) const { + return !compiler.getSourceManager().isInMainFile(spellingLocation) + && (StringRef( + compiler.getSourceManager().getPresumedLoc(spellingLocation) + .getFilename()) + .endswith(".h")); + } + + bool isSharedCAndCppCode(VarDecl const * decl) const { + auto loc = decl->getLocation(); + while (compiler.getSourceManager().isMacroArgExpansion(loc)) { + loc = compiler.getSourceManager().getImmediateMacroCallerLoc(loc); + } + // Assume that code is intended to be shared between C and C++ if it + // comes from an include file ending in .h, and is either in an extern + // "C" context or the body of a macro definition: + return + isFromCIncludeFile(compiler.getSourceManager().getSpellingLoc(loc)) + && (decl->isInExternCContext() + || compiler.getSourceManager().isMacroBodyExpansion(loc)); + } + + DeclRefExpr const * checkCast(ExplicitCastExpr const * expr) { + if (!loplugin::TypeCheck(expr->getTypeAsWritten()).Void()) { + return nullptr; + } + if (compiler.getSourceManager().isMacroBodyExpansion( + expr->getBeginLoc())) + { + return nullptr; + } + return dyn_cast(expr->getSubExpr()->IgnoreParenImpCasts()); + } + + void recordConsumption(Expr const * expr) { + for (;;) { + expr = expr->IgnoreParenImpCasts(); + if (auto const e = dyn_cast(expr)) { + expr = e->getBase(); + continue; + } + if (auto const e = dyn_cast(expr)) { + expr = e->getBase(); + continue; + } + if (auto const e = dyn_cast(expr)) { + if (e->getOpcode() == BO_PtrMemD) { + expr = e->getLHS(); + continue; + } + } + break; + } + auto const dre = dyn_cast(expr); + if (dre == nullptr) { + return; + } + // In C (but not in C++) + // + // (void) x + // + // contains an implicit lvalue-to-rvalue cast, so VisitImplicitCastExpr + // would record that as a consumption if we didn't filter it out here: + if (!castToVoid_.empty() && castToVoid_.top().sub == dre) { + return; + } + auto const var = dyn_cast(dre->getDecl()); + if (var == nullptr) { + return; + } + if (var->getType().isVolatileQualified()) { + return; + } + auto & usage = vars_[var->getCanonicalDecl()]; + if (usage.firstConsumption != nullptr) { + return; + } + auto const loc = dre->getBeginLoc(); + if (compiler.getSourceManager().isMacroArgExpansion(loc) + && (Lexer::getImmediateMacroNameForDiagnostics( + loc, compiler.getSourceManager(), compiler.getLangOpts()) + == "assert")) + { + return; + } + usage.firstConsumption = dre; + } +}; + +static loplugin::Plugin::Registration reg("casttovoid"); + +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */ -- cgit v1.2.3