/* * Cppcheck - A tool for static C/C++ code analysis * Copyright (C) 2007-2023 Cppcheck team. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ //--------------------------------------------------------------------------- #include "checkclass.h" #include "astutils.h" #include "library.h" #include "settings.h" #include "standards.h" #include "symboldatabase.h" #include "errorlogger.h" #include "errortypes.h" #include "mathlib.h" #include "token.h" #include "tokenize.h" #include "tokenlist.h" #include "utils.h" #include #include #include #include #include #include #include #include namespace CTU { class FileInfo; } //--------------------------------------------------------------------------- // Register CheckClass.. namespace { CheckClass instance; } static const CWE CWE398(398U); // Indicator of Poor Code Quality static const CWE CWE404(404U); // Improper Resource Shutdown or Release static const CWE CWE665(665U); // Improper Initialization static const CWE CWE758(758U); // Reliance on Undefined, Unspecified, or Implementation-Defined Behavior static const CWE CWE762(762U); // Mismatched Memory Management Routines static const CWE CWE_ONE_DEFINITION_RULE(758U); static const char * getFunctionTypeName(Function::Type type) { switch (type) { case Function::eConstructor: return "constructor"; case Function::eCopyConstructor: return "copy constructor"; case Function::eMoveConstructor: return "move constructor"; case Function::eDestructor: return "destructor"; case Function::eFunction: return "function"; case Function::eOperatorEqual: return "operator="; case Function::eLambda: return "lambda"; } return ""; } static bool isVariableCopyNeeded(const Variable &var, Function::Type type) { bool isOpEqual = false; switch (type) { case Function::eOperatorEqual: isOpEqual = true; break; case Function::eCopyConstructor: case Function::eMoveConstructor: break; default: return true; } return (!var.hasDefault() || isOpEqual) && // default init does not matter for operator= (var.isPointer() || (var.type() && var.type()->needInitialization == Type::NeedInitialization::True) || (var.valueType() && var.valueType()->type >= ValueType::Type::CHAR)); } static bool isVclTypeInit(const Type *type) { if (!type) return false; return std::any_of(type->derivedFrom.begin(), type->derivedFrom.end(), [&](const Type::BaseInfo& baseInfo) { if (!baseInfo.type) return true; if (isVclTypeInit(baseInfo.type)) return true; return false; }); } //--------------------------------------------------------------------------- CheckClass::CheckClass(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) : Check(myName(), tokenizer, settings, errorLogger), mSymbolDatabase(tokenizer?tokenizer->getSymbolDatabase():nullptr) {} //--------------------------------------------------------------------------- // ClassCheck: Check that all class constructors are ok. //--------------------------------------------------------------------------- void CheckClass::constructors() { const bool printStyle = mSettings->severity.isEnabled(Severity::style); const bool printWarnings = mSettings->severity.isEnabled(Severity::warning); if (!printStyle && !printWarnings) return; const bool printInconclusive = mSettings->certainty.isEnabled(Certainty::inconclusive); for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { if (mSettings->hasLib("vcl") && isVclTypeInit(scope->definedType)) continue; const bool unusedTemplate = Token::simpleMatch(scope->classDef->previous(), ">"); const bool usedInUnion = std::any_of(mSymbolDatabase->scopeList.cbegin(), mSymbolDatabase->scopeList.cend(), [&](const Scope& unionScope) { if (unionScope.type != Scope::eUnion) return false; return std::any_of(unionScope.varlist.cbegin(), unionScope.varlist.cend(), [&](const Variable& var) { return var.type() && var.type()->classScope == scope; }); }); // There are no constructors. if (scope->numConstructors == 0 && printStyle && !usedInUnion) { // If there is a private variable, there should be a constructor.. int needInit = 0, haveInit = 0; std::vector uninitVars; for (const Variable &var : scope->varlist) { if (var.isPrivate() && !var.isStatic() && (!var.isClass() || (var.type() && var.type()->needInitialization == Type::NeedInitialization::True))) { ++needInit; if (!var.isInit() && !var.hasDefault() && var.nameToken()->scope() == scope) // don't warn for anonymous union members uninitVars.emplace_back(&var); else ++haveInit; } } if (needInit > haveInit) { if (haveInit == 0) noConstructorError(scope->classDef, scope->className, scope->classDef->str() == "struct"); else for (const Variable* uv : uninitVars) uninitVarError(uv->typeStartToken(), uv->scope()->className, uv->name()); } } if (!printWarnings) continue; // #3196 => bailout if there are nested unions // TODO: handle union variables better { const bool bailout = std::any_of(scope->nestedList.cbegin(), scope->nestedList.cend(), [](const Scope* nestedScope) { return nestedScope->type == Scope::eUnion; }); if (bailout) continue; } std::vector usageList = createUsageList(scope); for (const Function &func : scope->functionList) { if (!(func.isConstructor() && (func.hasBody() || (func.isDefault() && func.type == Function::eConstructor))) && !(func.type == Function::eOperatorEqual && func.hasBody())) continue; // a defaulted constructor does not initialize primitive members // Bail: If initializer list is not recognized as a variable or type then skip since parsing is incomplete if (unusedTemplate && func.type == Function::eConstructor) { const Token *initList = func.constructorMemberInitialization(); if (Token::Match(initList, ": %name% (") && initList->next()->tokType() == Token::eName) break; } // Mark all variables not used clearAllVar(usageList); // Variables with default initializers for (Usage &usage : usageList) { const Variable& var = *usage.var; // check for C++11 initializer if (var.hasDefault() && func.type != Function::eOperatorEqual && func.type != Function::eCopyConstructor) { // variable still needs to be copied usage.init = true; } } std::list callstack; initializeVarList(func, callstack, scope, usageList); // Assign 1 union member => assign all union members for (const Usage &usage : usageList) { const Variable& var = *usage.var; if (!usage.assign && !usage.init) continue; const Scope* varScope1 = var.nameToken()->scope(); while (varScope1->type == Scope::ScopeType::eStruct) varScope1 = varScope1->nestedIn; if (varScope1->type == Scope::ScopeType::eUnion) { for (Usage &usage2 : usageList) { const Variable& var2 = *usage2.var; if (usage2.assign || usage2.init || var2.isStatic()) continue; const Scope* varScope2 = var2.nameToken()->scope(); while (varScope2->type == Scope::ScopeType::eStruct) varScope2 = varScope2->nestedIn; if (varScope1 == varScope2) usage2.assign = true; } } } // Check if any variables are uninitialized for (const Usage &usage : usageList) { const Variable& var = *usage.var; if (usage.assign || usage.init || var.isStatic()) continue; if (var.valueType() && var.valueType()->pointer == 0 && var.type() && var.type()->needInitialization == Type::NeedInitialization::False && var.type()->derivedFrom.empty()) continue; if (var.isConst() && func.isOperator()) // We can't set const members in assignment operator continue; // Check if this is a class constructor if (!var.isPointer() && !var.isPointerArray() && var.isClass() && func.type == Function::eConstructor) { // Unknown type so assume it is initialized if (!var.type()) { if (var.isStlType() && var.valueType() && var.valueType()->containerTypeToken && var.getTypeName() == "std::array") { const Token* ctt = var.valueType()->containerTypeToken; if (!ctt->isStandardType() && (!ctt->type() || ctt->type()->needInitialization != Type::NeedInitialization::True) && !mSettings->library.podtype(ctt->str())) // TODO: handle complex type expression continue; } else continue; } // Known type that doesn't need initialization or // known type that has member variables of an unknown type else if (var.type()->needInitialization != Type::NeedInitialization::True) continue; } // Check if type can't be copied if (!var.isPointer() && !var.isPointerArray() && var.typeScope()) { if (func.type == Function::eMoveConstructor) { if (canNotMove(var.typeScope())) continue; } else { if (canNotCopy(var.typeScope())) continue; } } // Is there missing member copy in copy/move constructor or assignment operator? bool missingCopy = false; // Don't warn about unknown types in copy constructors since we // don't know if they can be copied or not.. if (!isVariableCopyNeeded(var, func.type)) { if (!printInconclusive) continue; missingCopy = true; } // It's non-static and it's not initialized => error if (func.type == Function::eOperatorEqual) { const Token *operStart = func.arg; bool classNameUsed = false; for (const Token *operTok = operStart; operTok != operStart->link(); operTok = operTok->next()) { if (operTok->str() == scope->className) { classNameUsed = true; break; } } if (classNameUsed && mSettings->library.getTypeCheck("operatorEqVarError", var.getTypeName()) != Library::TypeCheck::suppress) operatorEqVarError(func.token, scope->className, var.name(), missingCopy); } else if (func.access != AccessControl::Private || mSettings->standards.cpp >= Standards::CPP11) { // If constructor is not in scope then we maybe using a constructor from a different template specialization if (!precedes(scope->bodyStart, func.tokenDef)) continue; const Scope *varType = var.typeScope(); if (!varType || varType->type != Scope::eUnion) { const bool derived = scope != var.scope(); if (func.type == Function::eConstructor && func.nestedIn && (func.nestedIn->numConstructors - func.nestedIn->numCopyOrMoveConstructors) > 1 && func.argCount() == 0 && func.functionScope && func.arg && func.arg->link()->next() == func.functionScope->bodyStart && func.functionScope->bodyStart->link() == func.functionScope->bodyStart->next()) { // don't warn about user defined default constructor when there are other constructors if (printInconclusive) uninitVarError(func.token, func.access == AccessControl::Private, func.type, var.scope()->className, var.name(), derived, true); } else if (missingCopy) missingMemberCopyError(func.token, func.type, var.scope()->className, var.name()); else uninitVarError(func.token, func.access == AccessControl::Private, func.type, var.scope()->className, var.name(), derived, false); } } } } } } void CheckClass::checkExplicitConstructors() { if (!mSettings->severity.isEnabled(Severity::style)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { // Do not perform check, if the class/struct has not any constructors if (scope->numConstructors == 0) continue; // Is class abstract? Maybe this test is over-simplification, but it will suffice for simple cases, // and it will avoid false positives. const bool isAbstractClass = std::any_of(scope->functionList.cbegin(), scope->functionList.cend(), [](const Function& func) { return func.isPure(); }); // Abstract classes can't be instantiated. But if there is C++11 // "misuse" by derived classes then these constructors must be explicit. if (isAbstractClass && mSettings->standards.cpp >= Standards::CPP11) continue; for (const Function &func : scope->functionList) { // We are looking for constructors, which are meeting following criteria: // 1) Constructor is declared with a single parameter // 2) Constructor is not declared as explicit // 3) It is not a copy/move constructor of non-abstract class // 4) Constructor is not marked as delete (programmer can mark the default constructor as deleted, which is ok) if (!func.isConstructor() || func.isDelete() || (!func.hasBody() && func.access == AccessControl::Private)) continue; if (!func.isExplicit() && func.argCount() > 0 && func.minArgCount() < 2 && func.type != Function::eCopyConstructor && func.type != Function::eMoveConstructor && !(func.templateDef && Token::simpleMatch(func.argumentList.front().typeEndToken(), "...")) && func.argumentList.front().getTypeName() != "std::initializer_list") { noExplicitConstructorError(func.tokenDef, scope->className, scope->type == Scope::eStruct); } } } } static bool hasNonCopyableBase(const Scope *scope, bool *unknown) { // check if there is base class that is not copyable for (const Type::BaseInfo &baseInfo : scope->definedType->derivedFrom) { if (!baseInfo.type || !baseInfo.type->classScope) { *unknown = true; continue; } if (hasNonCopyableBase(baseInfo.type->classScope, unknown)) return true; for (const Function &func : baseInfo.type->classScope->functionList) { if (func.type != Function::eCopyConstructor) continue; if (func.access == AccessControl::Private || func.isDelete()) { *unknown = false; return true; } } } return false; } void CheckClass::copyconstructors() { if (!mSettings->severity.isEnabled(Severity::warning)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { std::map allocatedVars; for (const Function &func : scope->functionList) { if (func.type != Function::eConstructor || !func.functionScope) continue; const Token* tok = func.token->linkAt(1); for (const Token* const end = func.functionScope->bodyStart; tok != end; tok = tok->next()) { if (Token::Match(tok, "%var% ( new") || (Token::Match(tok, "%var% ( %name% (") && mSettings->library.getAllocFuncInfo(tok->tokAt(2)))) { const Variable* var = tok->variable(); if (var && var->isPointer() && var->scope() == scope) allocatedVars[tok->varId()] = tok; } } for (const Token* const end = func.functionScope->bodyEnd; tok != end; tok = tok->next()) { if (Token::Match(tok, "%var% = new") || (Token::Match(tok, "%var% = %name% (") && mSettings->library.getAllocFuncInfo(tok->tokAt(2)))) { const Variable* var = tok->variable(); if (var && var->isPointer() && var->scope() == scope && !var->isStatic()) allocatedVars[tok->varId()] = tok; } } } if (!allocatedVars.empty()) { const Function *funcCopyCtor = nullptr; const Function *funcOperatorEq = nullptr; const Function *funcDestructor = nullptr; for (const Function &func : scope->functionList) { if (func.type == Function::eCopyConstructor) funcCopyCtor = &func; else if (func.type == Function::eOperatorEqual) funcOperatorEq = &func; else if (func.type == Function::eDestructor) funcDestructor = &func; } if (!funcCopyCtor || funcCopyCtor->isDefault()) { bool unknown = false; if (!hasNonCopyableBase(scope, &unknown) && !unknown) noCopyConstructorError(scope, funcCopyCtor, allocatedVars.cbegin()->second, unknown); } if (!funcOperatorEq || funcOperatorEq->isDefault()) { bool unknown = false; if (!hasNonCopyableBase(scope, &unknown) && !unknown) noOperatorEqError(scope, funcOperatorEq, allocatedVars.cbegin()->second, unknown); } if (!funcDestructor || funcDestructor->isDefault()) { const Token * mustDealloc = nullptr; for (std::map::const_iterator it = allocatedVars.cbegin(); it != allocatedVars.cend(); ++it) { if (!Token::Match(it->second, "%var% [(=] new %type%")) { mustDealloc = it->second; break; } if (it->second->valueType() && it->second->valueType()->isIntegral()) { mustDealloc = it->second; break; } const Variable *var = it->second->variable(); if (var && var->typeScope() && var->typeScope()->functionList.empty() && var->type()->derivedFrom.empty()) { mustDealloc = it->second; break; } } if (mustDealloc) noDestructorError(scope, funcDestructor, mustDealloc); } } std::set copiedVars; const Token* copyCtor = nullptr; for (const Function &func : scope->functionList) { if (func.type != Function::eCopyConstructor) continue; copyCtor = func.tokenDef; if (!func.functionScope) { allocatedVars.clear(); break; } const Token* tok = func.tokenDef->linkAt(1)->next(); if (tok->str()==":") { tok=tok->next(); while (Token::Match(tok, "%name% (")) { if (allocatedVars.find(tok->varId()) != allocatedVars.end()) { if (tok->varId() && Token::Match(tok->tokAt(2), "%name% . %name% )")) copiedVars.insert(tok); else if (!Token::Match(tok->tokAt(2), "%any% )")) allocatedVars.erase(tok->varId()); // Assume memory is allocated } tok = tok->linkAt(1)->tokAt(2); } } for (tok = func.functionScope->bodyStart; tok != func.functionScope->bodyEnd; tok = tok->next()) { if ((mTokenizer->isCPP() && Token::Match(tok, "%var% = new")) || (Token::Match(tok, "%var% = %name% (") && (mSettings->library.getAllocFuncInfo(tok->tokAt(2)) || mSettings->library.getReallocFuncInfo(tok->tokAt(2))))) { allocatedVars.erase(tok->varId()); } else if (Token::Match(tok, "%var% = %name% . %name% ;") && allocatedVars.find(tok->varId()) != allocatedVars.end()) { copiedVars.insert(tok); } } break; } if (copyCtor && !copiedVars.empty()) { for (const Token *cv : copiedVars) copyConstructorShallowCopyError(cv, cv->str()); // throw error if count mismatch /* FIXME: This doesn't work. See #4154 for (std::map::const_iterator i = allocatedVars.begin(); i != allocatedVars.end(); ++i) { copyConstructorMallocError(copyCtor, i->second, i->second->str()); } */ } } } /* This doesn't work. See #4154 void CheckClass::copyConstructorMallocError(const Token *cctor, const Token *alloc, const std::string& varname) { std::list callstack; callstack.push_back(cctor); callstack.push_back(alloc); reportError(callstack, Severity::warning, "copyCtorNoAllocation", "Copy constructor does not allocate memory for member '" + varname + "' although memory has been allocated in other constructors."); } */ void CheckClass::copyConstructorShallowCopyError(const Token *tok, const std::string& varname) { reportError(tok, Severity::warning, "copyCtorPointerCopying", "$symbol:" + varname + "\nValue of pointer '$symbol', which points to allocated memory, is copied in copy constructor instead of allocating new memory.", CWE398, Certainty::normal); } static std::string noMemberErrorMessage(const Scope *scope, const char function[], bool isdefault) { const std::string &classname = scope ? scope->className : "class"; const std::string type = (scope && scope->type == Scope::eStruct) ? "Struct" : "Class"; const bool isDestructor = (function[0] == 'd'); std::string errmsg = "$symbol:" + classname + '\n'; if (isdefault) { errmsg += type + " '$symbol' has dynamic memory/resource allocation(s). The " + function + " is explicitly defaulted but the default " + function + " does not work well."; if (isDestructor) errmsg += " It is recommended to define the " + std::string(function) + '.'; else errmsg += " It is recommended to define or delete the " + std::string(function) + '.'; } else { errmsg += type + " '$symbol' does not have a " + function + " which is recommended since it has dynamic memory/resource allocation(s)."; } return errmsg; } void CheckClass::noCopyConstructorError(const Scope *scope, bool isdefault, const Token *alloc, bool inconclusive) { reportError(alloc, Severity::warning, "noCopyConstructor", noMemberErrorMessage(scope, "copy constructor", isdefault), CWE398, inconclusive ? Certainty::inconclusive : Certainty::normal); } void CheckClass::noOperatorEqError(const Scope *scope, bool isdefault, const Token *alloc, bool inconclusive) { reportError(alloc, Severity::warning, "noOperatorEq", noMemberErrorMessage(scope, "operator=", isdefault), CWE398, inconclusive ? Certainty::inconclusive : Certainty::normal); } void CheckClass::noDestructorError(const Scope *scope, bool isdefault, const Token *alloc) { reportError(alloc, Severity::warning, "noDestructor", noMemberErrorMessage(scope, "destructor", isdefault), CWE398, Certainty::normal); } bool CheckClass::canNotCopy(const Scope *scope) { bool constructor = false; bool publicAssign = false; bool publicCopy = false; for (const Function &func : scope->functionList) { if (func.isConstructor()) constructor = true; if (func.access != AccessControl::Public) continue; if (func.type == Function::eCopyConstructor) { publicCopy = true; break; } if (func.type == Function::eOperatorEqual) { publicAssign = true; break; } } return constructor && !(publicAssign || publicCopy); } bool CheckClass::canNotMove(const Scope *scope) { bool constructor = false; bool publicAssign = false; bool publicCopy = false; bool publicMove = false; for (const Function &func : scope->functionList) { if (func.isConstructor()) constructor = true; if (func.access != AccessControl::Public) continue; if (func.type == Function::eCopyConstructor) { publicCopy = true; break; } if (func.type == Function::eMoveConstructor) { publicMove = true; break; } if (func.type == Function::eOperatorEqual) { publicAssign = true; break; } } return constructor && !(publicAssign || publicCopy || publicMove); } static void getAllVariableMembers(const Scope *scope, std::vector& varList) { std::transform(scope->varlist.cbegin(), scope->varlist.cend(), std::back_inserter(varList), [](const Variable& var) { return &var; }); if (scope->definedType) { for (const Type::BaseInfo& baseInfo: scope->definedType->derivedFrom) { if (scope->definedType == baseInfo.type) continue; const Scope *baseClass = baseInfo.type ? baseInfo.type->classScope : nullptr; if (baseClass && baseClass->isClassOrStruct() && baseClass->numConstructors == 0) getAllVariableMembers(baseClass, varList); } } } std::vector CheckClass::createUsageList(const Scope *scope) { std::vector ret; std::vector varlist; getAllVariableMembers(scope, varlist); ret.reserve(varlist.size()); std::transform(varlist.cbegin(), varlist.cend(), std::back_inserter(ret), [](const Variable* var) { return Usage(var); }); return ret; } void CheckClass::assignVar(std::vector &usageList, nonneg int varid) { for (Usage& usage: usageList) { if (usage.var->declarationId() == varid) { usage.assign = true; return; } } } void CheckClass::assignVar(std::vector &usageList, const Token* vartok) { if (vartok->varId() > 0) { assignVar(usageList, vartok->varId()); return; } for (Usage& usage: usageList) { // FIXME: This is a workaround when varid is not set for a derived member if (usage.var->name() == vartok->str()) { usage.assign = true; return; } } } void CheckClass::initVar(std::vector &usageList, nonneg int varid) { for (Usage& usage: usageList) { if (usage.var->declarationId() == varid) { usage.init = true; return; } } } void CheckClass::assignAllVar(std::vector &usageList) { for (Usage & i : usageList) i.assign = true; } void CheckClass::assignAllVarsVisibleFromScope(std::vector& usageList, const Scope* scope) { for (Usage& usage : usageList) { if (usage.var->scope() == scope) usage.assign = true; } // Iterate through each base class... for (const Type::BaseInfo& i : scope->definedType->derivedFrom) { const Type *derivedFrom = i.type; if (derivedFrom && derivedFrom->classScope) assignAllVarsVisibleFromScope(usageList, derivedFrom->classScope); } } void CheckClass::clearAllVar(std::vector &usageList) { for (Usage & i : usageList) { i.assign = false; i.init = false; } } bool CheckClass::isBaseClassMutableMemberFunc(const Token *tok, const Scope *scope) { // Iterate through each base class... for (const Type::BaseInfo & i : scope->definedType->derivedFrom) { const Type *derivedFrom = i.type; // Check if base class exists in database if (derivedFrom && derivedFrom->classScope) { const std::list& functionList = derivedFrom->classScope->functionList; if (std::any_of(functionList.cbegin(), functionList.cend(), [&](const Function& func) { return func.tokenDef->str() == tok->str() && !func.isStatic() && !func.isConst(); })) return true; if (isBaseClassMutableMemberFunc(tok, derivedFrom->classScope)) return true; } // Base class not found so assume it is in it. else return true; } return false; } void CheckClass::initializeVarList(const Function &func, std::list &callstack, const Scope *scope, std::vector &usage) const { if (!func.functionScope) return; bool initList = func.isConstructor(); const Token *ftok = func.arg->link()->next(); int level = 0; for (; ftok && ftok != func.functionScope->bodyEnd; ftok = ftok->next()) { // Class constructor.. initializing variables like this // clKalle::clKalle() : var(value) { } if (initList) { if (level == 0 && Token::Match(ftok, "%name% {|(") && Token::Match(ftok->linkAt(1), "}|) ,|{")) { if (ftok->str() != func.name()) { initVar(usage, ftok->varId()); } else { // c++11 delegate constructor const Function *member = ftok->function(); // member function not found => assume it initializes all members if (!member) { assignAllVar(usage); return; } // recursive call // assume that all variables are initialized if (std::find(callstack.cbegin(), callstack.cend(), member) != callstack.cend()) { /** @todo false negative: just bail */ assignAllVar(usage); return; } // member function has implementation if (member->hasBody()) { // initialize variable use list using member function callstack.push_back(member); initializeVarList(*member, callstack, scope, usage); callstack.pop_back(); } // there is a called member function, but it has no implementation, so we assume it initializes everything else { assignAllVar(usage); } } } else if (level != 0 && Token::Match(ftok, "%name% =")) // assignment in the initializer: var(value = x) assignVar(usage, ftok->varId()); // Level handling if (ftok->link() && Token::Match(ftok, "(|<")) level++; else if (ftok->str() == "{") { if (level != 0 || (Token::Match(ftok->previous(), "%name%|>") && Token::Match(ftok->link(), "} ,|{"))) level++; else initList = false; } else if (ftok->link() && Token::Match(ftok, ")|>|}")) level--; } if (initList) continue; // Variable getting value from stream? if (Token::Match(ftok, ">>|& %name%") && isLikelyStreamRead(true, ftok)) { assignVar(usage, ftok->next()->varId()); } // If assignment comes after an && or || this is really inconclusive because of short circuiting if (Token::Match(ftok, "%oror%|&&")) continue; if (Token::simpleMatch(ftok, "( !")) ftok = ftok->next(); // Using the operator= function to initialize all variables.. if (Token::Match(ftok->next(), "return| (| * this )| =")) { assignAllVar(usage); break; } // Using swap to assign all variables.. if (func.type == Function::eOperatorEqual && Token::Match(ftok, "[;{}] %name% (") && Token::Match(ftok->linkAt(2), ") . %name% ( *| this ) ;")) { assignAllVar(usage); break; } // Calling member variable function? if (Token::Match(ftok->next(), "%var% . %name% (") && !(ftok->next()->valueType() && ftok->next()->valueType()->pointer)) { if (std::any_of(scope->varlist.cbegin(), scope->varlist.cend(), [&](const Variable& var) { return var.declarationId() == ftok->next()->varId(); })) /** @todo false negative: we assume function changes variable state */ assignVar(usage, ftok->next()->varId()); ftok = ftok->tokAt(2); } if (!Token::Match(ftok->next(), "::| %name%") && !Token::Match(ftok->next(), "*| this . %name%") && !Token::Match(ftok->next(), "* %name% =") && !Token::Match(ftok->next(), "( * this ) . %name%")) continue; // Goto the first token in this statement.. ftok = ftok->next(); // skip "return" if (ftok->str() == "return") ftok = ftok->next(); // Skip "( * this )" if (Token::simpleMatch(ftok, "( * this ) .")) { ftok = ftok->tokAt(5); } // Skip "this->" if (Token::simpleMatch(ftok, "this .")) ftok = ftok->tokAt(2); // Skip "classname :: " if (Token::Match(ftok, ":: %name%")) ftok = ftok->next(); while (Token::Match(ftok, "%name% ::")) ftok = ftok->tokAt(2); // Clearing all variables.. if (Token::Match(ftok, "::| memset ( this ,")) { assignAllVar(usage); return; } // Ticket #7068 if (Token::Match(ftok, "::| memset ( &| this . %name%")) { if (ftok->str() == "::") ftok = ftok->next(); int offsetToMember = 4; if (ftok->strAt(2) == "&") ++offsetToMember; assignVar(usage, ftok->tokAt(offsetToMember)->varId()); ftok = ftok->linkAt(1); continue; } // Clearing array.. if (Token::Match(ftok, "::| memset ( %name% ,")) { if (ftok->str() == "::") ftok = ftok->next(); assignVar(usage, ftok->tokAt(2)->varId()); ftok = ftok->linkAt(1); continue; } // Calling member function? if (Token::simpleMatch(ftok, "operator= (")) { if (ftok->function()) { const Function *member = ftok->function(); // recursive call // assume that all variables are initialized if (std::find(callstack.cbegin(), callstack.cend(), member) != callstack.cend()) { /** @todo false negative: just bail */ assignAllVar(usage); return; } // member function has implementation if (member->hasBody()) { // initialize variable use list using member function callstack.push_back(member); initializeVarList(*member, callstack, scope, usage); callstack.pop_back(); } // assume that a base class call to operator= assigns all its base members (but not more) else if (func.tokenDef->str() == ftok->str() && isBaseClassMutableMemberFunc(ftok, scope)) { if (member->nestedIn) assignAllVarsVisibleFromScope(usage, member->nestedIn->definedType->classScope); } // there is a called member function, but it has no implementation, so we assume it initializes everything else { assignAllVar(usage); } } // using default operator =, assume everything initialized else { assignAllVar(usage); } } else if (Token::Match(ftok, "::| %name% (") && !Token::Match(ftok, "if|while|for")) { if (ftok->str() == "::") ftok = ftok->next(); // Passing "this" => assume that everything is initialized for (const Token *tok2 = ftok->next()->link(); tok2 && tok2 != ftok; tok2 = tok2->previous()) { if (tok2->str() == "this") { assignAllVar(usage); return; } } // check if member function if (ftok->function() && ftok->function()->nestedIn == scope && !ftok->function()->isConstructor()) { const Function *member = ftok->function(); // recursive call // assume that all variables are initialized if (std::find(callstack.cbegin(), callstack.cend(), member) != callstack.cend()) { assignAllVar(usage); return; } // member function has implementation if (member->hasBody()) { // initialize variable use list using member function callstack.push_back(member); initializeVarList(*member, callstack, scope, usage); callstack.pop_back(); // Assume that variables that are passed to it are initialized.. for (const Token *tok2 = ftok; tok2; tok2 = tok2->next()) { if (Token::Match(tok2, "[;{}]")) break; if (Token::Match(tok2, "[(,] &| %name% [,)]")) { tok2 = tok2->next(); if (tok2->str() == "&") tok2 = tok2->next(); if (isVariableChangedByFunctionCall(tok2, tok2->previous()->str() == "&", tok2->varId(), mSettings, nullptr)) assignVar(usage, tok2->varId()); } } } // there is a called member function, but it has no implementation, so we assume it initializes everything (if it can mutate state) else if (!member->isConst() && !member->isStatic()) { assignAllVar(usage); } } // not member function else { // could be a base class virtual function, so we assume it initializes everything if (!func.isConstructor() && isBaseClassMutableMemberFunc(ftok, scope)) { /** @todo False Negative: we should look at the base class functions to see if they * call any derived class virtual functions that change the derived class state */ assignAllVar(usage); } // has friends, so we assume it initializes everything if (!scope->definedType->friendList.empty()) assignAllVar(usage); // the function is external and it's neither friend nor inherited virtual function. // assume all variables that are passed to it are initialized.. else { for (const Token *tok = ftok->tokAt(2); tok && tok != ftok->next()->link(); tok = tok->next()) { if (tok->isName()) { assignVar(usage, tok->varId()); } } } } } // Assignment of member variable? else if (Token::Match(ftok, "%name% =")) { assignVar(usage, ftok); bool bailout = ftok->variable() && ftok->variable()->isReference(); const Token* tok2 = ftok->tokAt(2); if (tok2->str() == "&") { tok2 = tok2->next(); bailout = true; } if (tok2->variable() && (bailout || tok2->variable()->isArray()) && tok2->strAt(1) != "[") assignVar(usage, tok2->varId()); } // Assignment of array item of member variable? else if (Token::Match(ftok, "%name% [|.")) { const Token *tok2 = ftok; while (tok2) { if (tok2->strAt(1) == "[") tok2 = tok2->next()->link(); else if (Token::Match(tok2->next(), ". %name%")) tok2 = tok2->tokAt(2); else break; } if (tok2 && tok2->strAt(1) == "=") assignVar(usage, ftok->varId()); } // Assignment of array item of member variable? else if (Token::Match(ftok, "* %name% =")) { assignVar(usage, ftok->next()->varId()); } else if (Token::Match(ftok, "* this . %name% =")) { assignVar(usage, ftok->tokAt(3)->varId()); } // The functions 'clear' and 'Clear' are supposed to initialize variable. if (Token::Match(ftok, "%name% . clear|Clear (")) { assignVar(usage, ftok->varId()); } } } void CheckClass::noConstructorError(const Token *tok, const std::string &classname, bool isStruct) { // For performance reasons the constructor might be intentionally missing. Therefore this is not a "warning" reportError(tok, Severity::style, "noConstructor", "$symbol:" + classname + "\n" + "The " + std::string(isStruct ? "struct" : "class") + " '$symbol' does not declare a constructor although it has private member variables which likely require initialization.\n" "The " + std::string(isStruct ? "struct" : "class") + " '$symbol' does not declare a constructor " "although it has private member variables. Member variables of builtin types are left " "uninitialized when the class is instantiated. That may cause bugs or undefined behavior.", CWE398, Certainty::normal); } void CheckClass::noExplicitConstructorError(const Token *tok, const std::string &classname, bool isStruct) { const std::string message(std::string(isStruct ? "Struct" : "Class") + " '$symbol' has a constructor with 1 argument that is not explicit."); const std::string verbose(message + " Such, so called \"Converting constructors\", should in general be explicit for type safety reasons as that prevents unintended implicit conversions."); reportError(tok, Severity::style, "noExplicitConstructor", "$symbol:" + classname + '\n' + message + '\n' + verbose, CWE398, Certainty::normal); } void CheckClass::uninitVarError(const Token *tok, bool isprivate, Function::Type functionType, const std::string &classname, const std::string &varname, bool derived, bool inconclusive) { std::string ctor; if (functionType == Function::eCopyConstructor) ctor = "copy "; else if (functionType == Function::eMoveConstructor) ctor = "move "; std::string message("Member variable '$symbol' is not initialized in the " + ctor + "constructor."); if (derived) message += " Maybe it should be initialized directly in the class " + classname + "?"; std::string id = std::string("uninit") + (derived ? "Derived" : "") + "MemberVar" + (isprivate ? "Private" : ""); reportError(tok, Severity::warning, id, "$symbol:" + classname + "::" + varname + "\n" + message, CWE398, inconclusive ? Certainty::inconclusive : Certainty::normal); } void CheckClass::uninitVarError(const Token *tok, const std::string &classname, const std::string &varname) { const std::string message("Member variable '$symbol' is not initialized."); // report missing in-class initializer const std::string id = std::string("uninitMemberVarPrivate"); reportError(tok, Severity::warning, id, "$symbol:" + classname + "::" + varname + "\n" + message, CWE398, Certainty::normal); } void CheckClass::missingMemberCopyError(const Token *tok, Function::Type functionType, const std::string& classname, const std::string& varname) { const std::string ctor(functionType == Function::Type::eCopyConstructor ? "copy" : "move"); const std::string action(functionType == Function::Type::eCopyConstructor ? "copied?" : "moved?"); const std::string message = "$symbol:" + classname + "::" + varname + "\n" + "Member variable '$symbol' is not assigned in the " + ctor + " constructor. Should it be " + action; const char id[] = "missingMemberCopy"; reportError(tok, Severity::warning, id, message, CWE398, Certainty::inconclusive); } void CheckClass::operatorEqVarError(const Token *tok, const std::string &classname, const std::string &varname, bool inconclusive) { reportError(tok, Severity::warning, "operatorEqVarError", "$symbol:" + classname + "::" + varname + "\nMember variable '$symbol' is not assigned a value in '" + classname + "::operator='.", CWE398, inconclusive ? Certainty::inconclusive : Certainty::normal); } //--------------------------------------------------------------------------- // ClassCheck: Use initialization list instead of assignment //--------------------------------------------------------------------------- void CheckClass::initializationListUsage() { if (!mSettings->severity.isEnabled(Severity::performance)) return; for (const Scope *scope : mSymbolDatabase->functionScopes) { // Check every constructor if (!scope->function || !scope->function->isConstructor()) continue; // Do not warn when a delegate constructor is called if (const Token *initList = scope->function->constructorMemberInitialization()) { if (Token::Match(initList, ": %name% {|(") && initList->strAt(1) == scope->className) continue; } const Scope* owner = scope->functionOf; for (const Token* tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) { if (Token::Match(tok, "%name% (")) // Assignments might depend on this function call or if/for/while/switch statement from now on. break; if (Token::Match(tok, "try|do {")) break; if (!Token::Match(tok, "%var% =") || tok->strAt(-1) == "*" || tok->strAt(-1) == ".") continue; const Variable* var = tok->variable(); if (!var || var->scope() != owner || var->isStatic()) continue; if (var->isPointer() || var->isReference() || var->isEnumType()) continue; if (!WRONG_DATA(!var->valueType(), tok) && var->valueType()->type > ValueType::Type::ITERATOR) continue; // bailout: multi line lambda in rhs => do not warn if (findLambdaEndToken(tok->tokAt(2)) && tok->tokAt(2)->findExpressionStartEndTokens().second->linenr() > tok->tokAt(2)->linenr()) continue; // Access local var member in rhs => do not warn bool localmember = false; visitAstNodes(tok->next()->astOperand2(), [&](const Token *rhs) { if (rhs->str() == "." && rhs->astOperand1() && rhs->astOperand1()->variable() && rhs->astOperand1()->variable()->isLocal()) localmember = true; return ChildrenToVisit::op1_and_op2; }); if (localmember) continue; bool allowed = true; visitAstNodes(tok->next()->astOperand2(), [&](const Token *tok2) { const Variable* var2 = tok2->variable(); if (var2) { if (var2->scope() == owner && tok2->strAt(-1)!=".") { // Is there a dependency between two member variables? allowed = false; return ChildrenToVisit::done; } if (var2->isArray() && var2->isLocal()) { // Can't initialize with a local array allowed = false; return ChildrenToVisit::done; } } else if (tok2->str() == "this") { // 'this' instance is not completely constructed in initialization list allowed = false; return ChildrenToVisit::done; } else if (Token::Match(tok2, "%name% (") && tok2->strAt(-1) != "." && isMemberFunc(owner, tok2)) { // Member function called? allowed = false; return ChildrenToVisit::done; } return ChildrenToVisit::op1_and_op2; }); if (!allowed) continue; suggestInitializationList(tok, tok->str()); } } } void CheckClass::suggestInitializationList(const Token* tok, const std::string& varname) { reportError(tok, Severity::performance, "useInitializationList", "$symbol:" + varname + "\nVariable '$symbol' is assigned in constructor body. Consider performing initialization in initialization list.\n" "When an object of a class is created, the constructors of all member variables are called consecutively " "in the order the variables are declared, even if you don't explicitly write them to the initialization list. You " "could avoid assigning '$symbol' a value by passing the value to the constructor in the initialization list.", CWE398, Certainty::normal); } //--------------------------------------------------------------------------- // ClassCheck: Unused private functions //--------------------------------------------------------------------------- static bool checkFunctionUsage(const Function *privfunc, const Scope* scope) { if (!scope) return true; // Assume it is used, if scope is not seen for (std::list::const_iterator func = scope->functionList.cbegin(); func != scope->functionList.cend(); ++func) { if (func->functionScope) { if (Token::Match(func->tokenDef, "%name% (")) { for (const Token *ftok = func->tokenDef->tokAt(2); ftok && ftok->str() != ")"; ftok = ftok->next()) { if (Token::Match(ftok, "= %name% [(,)]") && ftok->strAt(1) == privfunc->name()) return true; if (ftok->str() == "(") ftok = ftok->link(); } } for (const Token *ftok = func->functionScope->classDef->linkAt(1); ftok != func->functionScope->bodyEnd; ftok = ftok->next()) { if (ftok->function() == privfunc) return true; if (ftok->varId() == 0U && ftok->str() == privfunc->name()) // TODO: This condition should be redundant return true; } } else if ((func->type != Function::eCopyConstructor && func->type != Function::eOperatorEqual) || func->access != AccessControl::Private) // Assume it is used, if a function implementation isn't seen, but empty private copy constructors and assignment operators are OK return true; } const std::map::const_iterator end = scope->definedTypesMap.cend(); for (std::map::const_iterator iter = scope->definedTypesMap.cbegin(); iter != end; ++iter) { const Type *type = (*iter).second; if (type->enclosingScope == scope && checkFunctionUsage(privfunc, type->classScope)) return true; } for (const Variable &var : scope->varlist) { if (var.isStatic()) { const Token* tok = Token::findmatch(scope->bodyStart, "%varid% =|(|{", var.declarationId()); if (tok) tok = tok->tokAt(2); while (tok && tok->str() != ";") { if (tok->function() == privfunc) return true; tok = tok->next(); } } } return false; // Unused in this scope } void CheckClass::privateFunctions() { if (!mSettings->severity.isEnabled(Severity::style)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { // do not check borland classes with properties.. if (Token::findsimplematch(scope->bodyStart, "; __property ;", scope->bodyEnd)) continue; std::list privateFuncs; for (const Function &func : scope->functionList) { // Get private functions.. if (func.type == Function::eFunction && func.access == AccessControl::Private && !func.isOperator()) // TODO: There are smarter ways to check private operator usage privateFuncs.push_back(&func); } // Bailout for overridden virtual functions of base classes if (!scope->definedType->derivedFrom.empty()) { // Check virtual functions for (std::list::iterator it = privateFuncs.begin(); it != privateFuncs.end();) { if ((*it)->isImplicitlyVirtual(true)) // Give true as default value to be returned if we don't see all base classes it = privateFuncs.erase(it); else ++it; } } while (!privateFuncs.empty()) { const auto& pf = privateFuncs.front(); if (pf->retDef && pf->retDef->isAttributeMaybeUnused()) { privateFuncs.pop_front(); continue; } // Check that all private functions are used bool used = checkFunctionUsage(pf, scope); // Usage in this class // Check in friend classes const std::vector& friendList = scope->definedType->friendList; for (int i = 0; i < friendList.size() && !used; i++) { if (friendList[i].type) used = checkFunctionUsage(pf, friendList[i].type->classScope); else used = true; // Assume, it is used if we do not see friend class } if (!used) unusedPrivateFunctionError(pf->tokenDef, scope->className, pf->name()); privateFuncs.pop_front(); } } } void CheckClass::unusedPrivateFunctionError(const Token *tok, const std::string &classname, const std::string &funcname) { reportError(tok, Severity::style, "unusedPrivateFunction", "$symbol:" + classname + "::" + funcname + "\nUnused private function: '$symbol'", CWE398, Certainty::normal); } //--------------------------------------------------------------------------- // ClassCheck: Check that memset is not used on classes //--------------------------------------------------------------------------- static const Scope* findFunctionOf(const Scope* scope) { while (scope) { if (scope->type == Scope::eFunction) return scope->functionOf; scope = scope->nestedIn; } return nullptr; } void CheckClass::checkMemset() { const bool printWarnings = mSettings->severity.isEnabled(Severity::warning); for (const Scope *scope : mSymbolDatabase->functionScopes) { for (const Token *tok = scope->bodyStart; tok && tok != scope->bodyEnd; tok = tok->next()) { if (Token::Match(tok, "memset|memcpy|memmove (")) { const Token* arg1 = tok->tokAt(2); const Token* arg3 = arg1->nextArgument(); if (arg3) arg3 = arg3->nextArgument(); if (!arg3) // weird, shouldn't happen: memset etc should have // 3 arguments. continue; const Token *typeTok = nullptr; const Scope *type = nullptr; const Token* sizeofTok = arg3->previous()->astOperand2(); // try to find sizeof() in argument expression if (sizeofTok && sizeofTok->astOperand1() && Token::simpleMatch(sizeofTok->astOperand1()->previous(), "sizeof (")) sizeofTok = sizeofTok->astOperand1(); else if (sizeofTok && sizeofTok->astOperand2() && Token::simpleMatch(sizeofTok->astOperand2()->previous(), "sizeof (")) sizeofTok = sizeofTok->astOperand2(); if (Token::simpleMatch(sizeofTok, "(")) sizeofTok = sizeofTok->previous(); if (Token::Match(sizeofTok, "sizeof ( %type% )")) typeTok = sizeofTok->tokAt(2); else if (Token::Match(sizeofTok, "sizeof ( %type% :: %type% )")) typeTok = sizeofTok->tokAt(4); else if (Token::Match(sizeofTok, "sizeof ( struct %type% )")) typeTok = sizeofTok->tokAt(3); else if (Token::simpleMatch(sizeofTok, "sizeof ( * this )") || Token::simpleMatch(arg1, "this ,")) { type = findFunctionOf(sizeofTok->scope()); } else if (Token::Match(arg1, "&|*|%var%")) { int numIndirToVariableType = 0; // Offset to the actual type in terms of dereference/addressof for (;; arg1 = arg1->next()) { if (arg1->str() == "&") ++numIndirToVariableType; else if (arg1->str() == "*") --numIndirToVariableType; else break; } const Variable * const var = arg1->variable(); if (var && arg1->strAt(1) == ",") { if (var->isArrayOrPointer()) { const Token *endTok = var->typeEndToken(); while (Token::simpleMatch(endTok, "*")) { ++numIndirToVariableType; endTok = endTok->previous(); } } if (var->isArray()) numIndirToVariableType += int(var->dimensions().size()); if (numIndirToVariableType == 1) type = var->typeScope(); if (!type && !var->isPointer() && !Token::simpleMatch(var->typeStartToken(), "std :: array") && mSettings->library.detectContainerOrIterator(var->typeStartToken())) { memsetError(tok, tok->str(), var->getTypeName(), {}, /*isContainer*/ true); } } } // No type defined => The tokens didn't match if (!typeTok && !type) continue; if (typeTok && typeTok->str() == "(") typeTok = typeTok->next(); if (!type && typeTok->type()) type = typeTok->type()->classScope; if (type) { const std::set parsedTypes; checkMemsetType(scope, tok, type, false, parsedTypes); } } else if (tok->variable() && tok->variable()->typeScope() && Token::Match(tok, "%var% = %name% (") && (mSettings->library.getAllocFuncInfo(tok->tokAt(2)) || mSettings->library.getReallocFuncInfo(tok->tokAt(2)))) { const std::set parsedTypes; checkMemsetType(scope, tok->tokAt(2), tok->variable()->typeScope(), true, parsedTypes); if (printWarnings && tok->variable()->typeScope()->numConstructors > 0) mallocOnClassWarning(tok, tok->strAt(2), tok->variable()->typeScope()->classDef); } } } } void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Scope *type, bool allocation, std::set parsedTypes) { // If type has been checked there is no need to check it again if (parsedTypes.find(type) != parsedTypes.end()) return; parsedTypes.insert(type); const bool printPortability = mSettings->severity.isEnabled(Severity::portability); // recursively check all parent classes for (const Type::BaseInfo & i : type->definedType->derivedFrom) { const Type* derivedFrom = i.type; if (derivedFrom && derivedFrom->classScope) checkMemsetType(start, tok, derivedFrom->classScope, allocation, parsedTypes); } // Warn if type is a class that contains any virtual functions for (const Function &func : type->functionList) { if (func.hasVirtualSpecifier()) { if (allocation) mallocOnClassError(tok, tok->str(), type->classDef, "virtual function"); else memsetError(tok, tok->str(), "virtual function", type->classDef->str()); } } // Warn if type is a class or struct that contains any std::* variables for (const Variable &var : type->varlist) { if (var.isReference() && !var.isStatic()) { memsetErrorReference(tok, tok->str(), type->classDef->str()); continue; } // don't warn if variable static or const, pointer or array of pointers if (!var.isStatic() && !var.isConst() && !var.isPointer() && (!var.isArray() || var.typeEndToken()->str() != "*")) { const Token *tok1 = var.typeStartToken(); const Scope *typeScope = var.typeScope(); std::string typeName; if (Token::Match(tok1, "%type% ::")) { const Token *typeTok = tok1; while (Token::Match(typeTok, "%type% ::")) { typeName += typeTok->str() + "::"; typeTok = typeTok->tokAt(2); } typeName += typeTok->str(); } // check for std:: type if (var.isStlType() && typeName != "std::array" && !mSettings->library.podtype(typeName)) { if (allocation) mallocOnClassError(tok, tok->str(), type->classDef, "'" + typeName + "'"); else memsetError(tok, tok->str(), "'" + typeName + "'", type->classDef->str()); } // check for known type else if (typeScope && typeScope != type) checkMemsetType(start, tok, typeScope, allocation, parsedTypes); // check for float else if (printPortability && var.isFloatingType() && tok->str() == "memset") memsetErrorFloat(tok, type->classDef->str()); } } } void CheckClass::mallocOnClassWarning(const Token* tok, const std::string &memfunc, const Token* classTok) { std::list toks = { tok, classTok }; reportError(toks, Severity::warning, "mallocOnClassWarning", "$symbol:" + memfunc +"\n" "Memory for class instance allocated with $symbol(), but class provides constructors.\n" "Memory for class instance allocated with $symbol(), but class provides constructors. This is unsafe, " "since no constructor is called and class members remain uninitialized. Consider using 'new' instead.", CWE762, Certainty::normal); } void CheckClass::mallocOnClassError(const Token* tok, const std::string &memfunc, const Token* classTok, const std::string &classname) { std::list toks = { tok, classTok }; reportError(toks, Severity::error, "mallocOnClassError", "$symbol:" + memfunc +"\n" "$symbol:" + classname +"\n" "Memory for class instance allocated with " + memfunc + "(), but class contains a " + classname + ".\n" "Memory for class instance allocated with " + memfunc + "(), but class a " + classname + ". This is unsafe, " "since no constructor is called and class members remain uninitialized. Consider using 'new' instead.", CWE665, Certainty::normal); } void CheckClass::memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type, bool isContainer) { const std::string typeStr = isContainer ? std::string() : (type + " that contains a "); const std::string msg = "$symbol:" + memfunc + "\n" "$symbol:" + classname + "\n" "Using '" + memfunc + "' on " + typeStr + classname + ".\n" "Using '" + memfunc + "' on " + typeStr + classname + " is unsafe, because constructor, destructor " "and copy operator calls are omitted. These are necessary for this non-POD type to ensure that a valid object " "is created."; reportError(tok, Severity::error, "memsetClass", msg, CWE762, Certainty::normal); } void CheckClass::memsetErrorReference(const Token *tok, const std::string &memfunc, const std::string &type) { reportError(tok, Severity::error, "memsetClassReference", "$symbol:" + memfunc +"\n" "Using '" + memfunc + "' on " + type + " that contains a reference.", CWE665, Certainty::normal); } void CheckClass::memsetErrorFloat(const Token *tok, const std::string &type) { reportError(tok, Severity::portability, "memsetClassFloat", "Using memset() on " + type + " which contains a floating point number.\n" "Using memset() on " + type + " which contains a floating point number." " This is not portable because memset() sets each byte of a block of memory to a specific value and" " the actual representation of a floating-point value is implementation defined." " Note: In case of an IEEE754-1985 compatible implementation setting all bits to zero results in the value 0.0.", CWE758, Certainty::normal); } //--------------------------------------------------------------------------- // ClassCheck: "C& operator=(const C&) { ... return *this; }" // operator= should return a reference to *this //--------------------------------------------------------------------------- void CheckClass::operatorEqRetRefThis() { if (!mSettings->severity.isEnabled(Severity::style)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { for (std::list::const_iterator func = scope->functionList.cbegin(); func != scope->functionList.cend(); ++func) { if (func->type == Function::eOperatorEqual && func->hasBody()) { // make sure return signature is correct if (func->retType == func->nestedIn->definedType && func->tokenDef->strAt(-1) == "&") { checkReturnPtrThis(scope, &(*func), func->functionScope->bodyStart, func->functionScope->bodyEnd); } } } } } void CheckClass::checkReturnPtrThis(const Scope *scope, const Function *func, const Token *tok, const Token *last) { std::set analyzedFunctions; checkReturnPtrThis(scope, func, tok, last, analyzedFunctions); } void CheckClass::checkReturnPtrThis(const Scope *scope, const Function *func, const Token *tok, const Token *last, std::set& analyzedFunctions) { bool foundReturn = false; const Token* const startTok = tok; for (; tok && tok != last; tok = tok->next()) { // check for return of reference to this if (const Token* lScope = isLambdaCaptureList(tok)) // skip lambda tok = lScope->link(); if (tok->str() != "return") continue; foundReturn = true; const Token *retExpr = tok->astOperand1(); if (retExpr && retExpr->str() == "=") retExpr = retExpr->astOperand1(); if (retExpr && retExpr->isUnaryOp("*") && Token::simpleMatch(retExpr->astOperand1(), "this")) continue; std::string cast("( " + scope->className + " & )"); if (Token::simpleMatch(tok->next(), cast.c_str(), cast.size())) tok = tok->tokAt(4); // check if a function is called if (tok->strAt(2) == "(" && tok->linkAt(2)->next()->str() == ";") { // check if it is a member function for (std::list::const_iterator it = scope->functionList.cbegin(); it != scope->functionList.cend(); ++it) { // check for a regular function with the same name and a body if (it->type == Function::eFunction && it->hasBody() && it->token->str() == tok->next()->str()) { // check for the proper return type if (it->tokenDef->previous()->str() == "&" && it->tokenDef->strAt(-2) == scope->className) { // make sure it's not a const function if (!it->isConst()) { /** @todo make sure argument types match */ // avoid endless recursions if (analyzedFunctions.find(&*it) == analyzedFunctions.end()) { analyzedFunctions.insert(&*it); checkReturnPtrThis(scope, &*it, it->arg->link()->next(), it->arg->link()->next()->link(), analyzedFunctions); } // just bail for now else return; } } } } } // check if *this is returned else if (!(Token::simpleMatch(tok->next(), "operator= (") || Token::simpleMatch(tok->next(), "this . operator= (") || (Token::Match(tok->next(), "%type% :: operator= (") && tok->next()->str() == scope->className))) operatorEqRetRefThisError(func->token); } if (foundReturn) { return; } if (startTok->next() == last) { const std::string tmp("( const " + scope->className + " &"); if (Token::simpleMatch(func->argDef, tmp.c_str(), tmp.size())) { // Typical wrong way to suppress default assignment operator by declaring it and leaving empty operatorEqMissingReturnStatementError(func->token, func->access == AccessControl::Public); } else { operatorEqMissingReturnStatementError(func->token, true); } return; } if (mSettings->library.isScopeNoReturn(last, nullptr)) { // Typical wrong way to prohibit default assignment operator // by always throwing an exception or calling a noreturn function operatorEqShouldBeLeftUnimplementedError(func->token); return; } operatorEqMissingReturnStatementError(func->token, func->access == AccessControl::Public); } void CheckClass::operatorEqRetRefThisError(const Token *tok) { reportError(tok, Severity::style, "operatorEqRetRefThis", "'operator=' should return reference to 'this' instance.", CWE398, Certainty::normal); } void CheckClass::operatorEqShouldBeLeftUnimplementedError(const Token *tok) { reportError(tok, Severity::style, "operatorEqShouldBeLeftUnimplemented", "'operator=' should either return reference to 'this' instance or be declared private and left unimplemented.", CWE398, Certainty::normal); } void CheckClass::operatorEqMissingReturnStatementError(const Token *tok, bool error) { if (error) { reportError(tok, Severity::error, "operatorEqMissingReturnStatement", "No 'return' statement in non-void function causes undefined behavior.", CWE398, Certainty::normal); } else { operatorEqRetRefThisError(tok); } } //--------------------------------------------------------------------------- // ClassCheck: "C& operator=(const C& rhs) { if (this == &rhs) ... }" // operator= should check for assignment to self // // For simple classes, an assignment to self check is only a potential optimization. // // For classes that allocate dynamic memory, assignment to self can be a real error // if it is deallocated and allocated again without being checked for. // // This check is not valid for classes with multiple inheritance because a // class can have multiple addresses so there is no trivial way to check for // assignment to self. //--------------------------------------------------------------------------- void CheckClass::operatorEqToSelf() { if (!mSettings->severity.isEnabled(Severity::warning)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { // skip classes with multiple inheritance if (scope->definedType->derivedFrom.size() > 1) continue; for (const Function &func : scope->functionList) { if (func.type == Function::eOperatorEqual && func.hasBody()) { // make sure that the operator takes an object of the same type as *this, otherwise we can't detect self-assignment checks if (func.argumentList.empty()) continue; const Token* typeTok = func.argumentList.front().typeEndToken(); while (typeTok->str() == "const" || typeTok->str() == "&" || typeTok->str() == "*") typeTok = typeTok->previous(); if (typeTok->str() != scope->className) continue; // make sure return signature is correct if (Token::Match(func.retDef, "%type% &") && func.retDef->str() == scope->className) { // find the parameter name const Token *rhs = func.argumentList.cbegin()->nameToken(); const Token* out_ifStatementScopeStart = nullptr; if (!hasAssignSelf(&func, rhs, &out_ifStatementScopeStart)) { if (hasAllocation(&func, scope)) operatorEqToSelfError(func.token); } else if (out_ifStatementScopeStart != nullptr) { if (hasAllocationInIfScope(&func, scope, out_ifStatementScopeStart)) operatorEqToSelfError(func.token); } } } } } } bool CheckClass::hasAllocationInIfScope(const Function *func, const Scope* scope, const Token *ifStatementScopeStart) const { const Token *end; if (ifStatementScopeStart->str() == "{") end = ifStatementScopeStart->link(); else end = func->functionScope->bodyEnd; return hasAllocation(func, scope, ifStatementScopeStart, end); } bool CheckClass::hasAllocation(const Function *func, const Scope* scope) const { return hasAllocation(func, scope, func->functionScope->bodyStart, func->functionScope->bodyEnd); } bool CheckClass::hasAllocation(const Function *func, const Scope* scope, const Token *start, const Token *end) const { if (!end) end = func->functionScope->bodyEnd; for (const Token *tok = start; tok && (tok != end); tok = tok->next()) { if (((mTokenizer->isCPP() && Token::Match(tok, "%var% = new")) || (Token::Match(tok, "%var% = %name% (") && mSettings->library.getAllocFuncInfo(tok->tokAt(2)))) && isMemberVar(scope, tok)) return true; // check for deallocating memory const Token *var; if (Token::Match(tok, "%name% ( %var%") && mSettings->library.getDeallocFuncInfo(tok)) var = tok->tokAt(2); else if (mTokenizer->isCPP() && Token::Match(tok, "delete [ ] %var%")) var = tok->tokAt(3); else if (mTokenizer->isCPP() && Token::Match(tok, "delete %var%")) var = tok->next(); else continue; // Check for assignment to the deleted pointer (only if its a member of the class) if (isMemberVar(scope, var)) { for (const Token *tok1 = var->next(); tok1 && (tok1 != end); tok1 = tok1->next()) { if (Token::Match(tok1, "%varid% =", var->varId())) return true; } } } return false; } static bool isTrueKeyword(const Token* tok) { return tok->hasKnownIntValue() && tok->getKnownIntValue() == 1; } static bool isFalseKeyword(const Token* tok) { return tok->hasKnownIntValue() && tok->getKnownIntValue() == 0; } /* * Checks if self-assignment test is inverse * For example 'if (this == &rhs)' */ CheckClass::Bool CheckClass::isInverted(const Token *tok, const Token *rhs) { bool res = true; for (const Token *itr = tok; itr && itr->str()!="("; itr=itr->astParent()) { if (Token::simpleMatch(itr, "!=") && (isTrueKeyword(itr->astOperand1()) || isTrueKeyword(itr->astOperand2()))) { res = !res; } else if (Token::simpleMatch(itr, "!=") && ((Token::simpleMatch(itr->astOperand1(), "this") && Token::simpleMatch(itr->astOperand2(), "&") && Token::simpleMatch(itr->astOperand2()->next(), rhs->str().c_str(), rhs->str().size())) || (Token::simpleMatch(itr->astOperand2(), "this") && Token::simpleMatch(itr->astOperand1(), "&") && Token::simpleMatch(itr->astOperand1()->next(), rhs->str().c_str(), rhs->str().size())))) { res = !res; } else if (Token::simpleMatch(itr, "!=") && (isFalseKeyword(itr->astOperand1()) || isFalseKeyword(itr->astOperand2()))) { //Do nothing } else if (Token::simpleMatch(itr, "!")) { res = !res; } else if (Token::simpleMatch(itr, "==") && (isFalseKeyword(itr->astOperand1()) || isFalseKeyword(itr->astOperand2()))) { res = !res; } else if (Token::simpleMatch(itr, "==") && (isTrueKeyword(itr->astOperand1()) || isTrueKeyword(itr->astOperand2()))) { //Do nothing } else if (Token::simpleMatch(itr, "==") && ((Token::simpleMatch(itr->astOperand1(), "this") && Token::simpleMatch(itr->astOperand2(), "&") && Token::simpleMatch(itr->astOperand2()->next(), rhs->str().c_str(), rhs->str().size())) || (Token::simpleMatch(itr->astOperand2(), "this") && Token::simpleMatch(itr->astOperand1(), "&") && Token::simpleMatch(itr->astOperand1()->next(), rhs->str().c_str(), rhs->str().size())))) { //Do nothing } else { return Bool::BAILOUT; } } if (res) return Bool::TRUE; return Bool::FALSE; } const Token * CheckClass::getIfStmtBodyStart(const Token *tok, const Token *rhs) { const Token *top = tok->astTop(); if (Token::simpleMatch(top->link(), ") {")) { switch (isInverted(tok->astParent(), rhs)) { case Bool::BAILOUT: return nullptr; case Bool::TRUE: return top->link()->next(); case Bool::FALSE: return top->link()->next()->link(); } } return nullptr; } bool CheckClass::hasAssignSelf(const Function *func, const Token *rhs, const Token **out_ifStatementScopeStart) { if (!rhs) return false; const Token *last = func->functionScope->bodyEnd; for (const Token *tok = func->functionScope->bodyStart; tok && tok != last; tok = tok->next()) { if (!Token::simpleMatch(tok, "if (")) continue; bool ret = false; visitAstNodes(tok->next()->astOperand2(), [&](const Token *tok2) { if (!Token::Match(tok2, "==|!=")) return ChildrenToVisit::op1_and_op2; if (Token::simpleMatch(tok2->astOperand1(), "this")) tok2 = tok2->astOperand2(); else if (Token::simpleMatch(tok2->astOperand2(), "this")) tok2 = tok2->astOperand1(); else return ChildrenToVisit::op1_and_op2; if (tok2 && tok2->isUnaryOp("&") && tok2->astOperand1()->str() == rhs->str()) ret = true; if (ret) { *out_ifStatementScopeStart = getIfStmtBodyStart(tok2, rhs); } return ret ? ChildrenToVisit::done : ChildrenToVisit::op1_and_op2; }); if (ret) return ret; } return false; } void CheckClass::operatorEqToSelfError(const Token *tok) { reportError(tok, Severity::warning, "operatorEqToSelf", "'operator=' should check for assignment to self to avoid problems with dynamic memory.\n" "'operator=' should check for assignment to self to ensure that each block of dynamically " "allocated memory is owned and managed by only one instance of the class.", CWE398, Certainty::normal); } //--------------------------------------------------------------------------- // A destructor in a base class should be virtual //--------------------------------------------------------------------------- void CheckClass::virtualDestructor() { // This error should only be given if: // * base class doesn't have virtual destructor // * derived class has non-empty destructor (only c++03, in c++11 it's UB see paragraph 3 in [expr.delete]) // * base class is deleted // unless inconclusive in which case: // * A class with any virtual functions should have a destructor that is either public and virtual or protected const bool printInconclusive = mSettings->certainty.isEnabled(Certainty::inconclusive); std::list inconclusiveErrors; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { // Skip base classes (unless inconclusive) if (scope->definedType->derivedFrom.empty()) { if (printInconclusive) { const Function *destructor = scope->getDestructor(); if (destructor && !destructor->hasVirtualSpecifier() && destructor->access == AccessControl::Public) { if (std::any_of(scope->functionList.cbegin(), scope->functionList.cend(), [](const Function& func) { return func.hasVirtualSpecifier(); })) inconclusiveErrors.push_back(destructor); } } continue; } // Check if destructor is empty and non-empty .. if (mSettings->standards.cpp <= Standards::CPP03) { // Find the destructor const Function *destructor = scope->getDestructor(); // Check for destructor with implementation if (!destructor || !destructor->hasBody()) continue; // Empty destructor if (destructor->token->linkAt(3) == destructor->token->tokAt(4)) continue; } const Token *derived = scope->classDef; const Token *derivedClass = derived->next(); // Iterate through each base class... for (const Type::BaseInfo & j : scope->definedType->derivedFrom) { // Check if base class is public and exists in database if (j.access != AccessControl::Private && j.type) { const Type *derivedFrom = j.type; const Scope *derivedFromScope = derivedFrom->classScope; if (!derivedFromScope) continue; // Check for this pattern: // 1. Base class pointer is given the address of derived class instance // 2. Base class pointer is deleted // // If this pattern is not seen then bailout the checking of these base/derived classes { // pointer variables of type 'Base *' std::set baseClassPointers; for (const Variable* var : mSymbolDatabase->variableList()) { if (var && var->isPointer() && var->type() == derivedFrom) baseClassPointers.insert(var->declarationId()); } // pointer variables of type 'Base *' that should not be deleted std::set dontDelete; // No deletion of derived class instance through base class pointer found => the code is ok bool ok = true; for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) { if (Token::Match(tok, "[;{}] %var% =") && baseClassPointers.find(tok->next()->varId()) != baseClassPointers.end()) { // new derived class.. const std::string tmp("new " + derivedClass->str()); if (Token::simpleMatch(tok->tokAt(3), tmp.c_str(), tmp.size())) { dontDelete.insert(tok->next()->varId()); } } // Delete base class pointer that might point at derived class else if (Token::Match(tok, "delete %var% ;") && dontDelete.find(tok->next()->varId()) != dontDelete.end()) { ok = false; break; } } // No base class pointer that points at a derived class is deleted if (ok) continue; } // Find the destructor declaration for the base class. const Function *baseDestructor = derivedFromScope->getDestructor(); // Check that there is a destructor.. if (!baseDestructor) { if (derivedFrom->derivedFrom.empty()) { virtualDestructorError(derivedFrom->classDef, derivedFrom->name(), derivedClass->str(), false); } } else if (!baseDestructor->hasVirtualSpecifier()) { // TODO: This is just a temporary fix, better solution is needed. // Skip situations where base class has base classes of its own, because // some of the base classes might have virtual destructor. // Proper solution is to check all of the base classes. If base class is not // found or if one of the base classes has virtual destructor, error should not // be printed. See TODO test case "virtualDestructorInherited" if (derivedFrom->derivedFrom.empty()) { // Make sure that the destructor is public (protected or private // would not compile if inheritance is used in a way that would // cause the bug we are trying to find here.) if (baseDestructor->access == AccessControl::Public) { virtualDestructorError(baseDestructor->token, derivedFrom->name(), derivedClass->str(), false); // check for duplicate error and remove it if found const std::list::iterator found = find(inconclusiveErrors.begin(), inconclusiveErrors.end(), baseDestructor); if (found != inconclusiveErrors.end()) inconclusiveErrors.erase(found); } } } } } } for (const Function *func : inconclusiveErrors) virtualDestructorError(func->tokenDef, func->name(), emptyString, true); } void CheckClass::virtualDestructorError(const Token *tok, const std::string &Base, const std::string &Derived, bool inconclusive) { if (inconclusive) { if (mSettings->severity.isEnabled(Severity::warning)) reportError(tok, Severity::warning, "virtualDestructor", "$symbol:" + Base + "\nClass '$symbol' which has virtual members does not have a virtual destructor.", CWE404, Certainty::inconclusive); } else { reportError(tok, Severity::error, "virtualDestructor", "$symbol:" + Base +"\n" "$symbol:" + Derived +"\n" "Class '" + Base + "' which is inherited by class '" + Derived + "' does not have a virtual destructor.\n" "Class '" + Base + "' which is inherited by class '" + Derived + "' does not have a virtual destructor. " "If you destroy instances of the derived class by deleting a pointer that points to the base class, only " "the destructor of the base class is executed. Thus, dynamic memory that is managed by the derived class " "could leak. This can be avoided by adding a virtual destructor to the base class.", CWE404, Certainty::normal); } } //--------------------------------------------------------------------------- // warn for "this-x". The indented code may be "this->x" //--------------------------------------------------------------------------- void CheckClass::thisSubtraction() { if (!mSettings->severity.isEnabled(Severity::warning)) return; const Token *tok = mTokenizer->tokens(); for (;;) { tok = Token::findmatch(tok, "this - %name%"); if (!tok) break; if (tok->strAt(-1) != "*") thisSubtractionError(tok); tok = tok->next(); } } void CheckClass::thisSubtractionError(const Token *tok) { reportError(tok, Severity::warning, "thisSubtraction", "Suspicious pointer subtraction. Did you intend to write '->'?", CWE398, Certainty::normal); } //--------------------------------------------------------------------------- // can member function be const? //--------------------------------------------------------------------------- void CheckClass::checkConst() { // This is an inconclusive check. False positives: #3322. if (!mSettings->certainty.isEnabled(Certainty::inconclusive)) return; if (!mSettings->severity.isEnabled(Severity::style)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { for (const Function &func : scope->functionList) { // does the function have a body? if (func.type != Function::eFunction || !func.hasBody()) continue; // don't warn for friend/static/virtual functions if (func.isFriend() || func.isStatic() || func.hasVirtualSpecifier()) continue; // don't suggest const when returning non-const pointer/reference, but still suggest static auto isPointerOrReference = [this](const Token* start, const Token* end) -> bool { bool inTemplArgList = false, isConstTemplArg = false; for (const Token* tok = start; tok != end; tok = tok->next()) { if (tok->str() == "{") // end of trailing return type return false; if (tok->str() == "<") { if (!tok->link()) mSymbolDatabase->debugMessage(tok, "debug", "CheckClass::checkConst found unlinked template argument list '" + tok->expressionString() + "'."); inTemplArgList = true; } else if (tok->str() == ">") { inTemplArgList = false; isConstTemplArg = false; } else if (tok->str() == "const") { if (!inTemplArgList) return false; isConstTemplArg = true; } else if (!isConstTemplArg && Token::Match(tok, "*|&")) return true; } return false; }; const bool returnsPtrOrRef = isPointerOrReference(func.retDef, func.tokenDef); if (Function::returnsPointer(&func, /*unknown*/ true) || Function::returnsReference(&func, /*unknown*/ true, /*includeRValueRef*/ true)) { // returns const/non-const depending on template arg bool isTemplateArg = false; for (const Token* tok2 = func.retDef; precedes(tok2, func.token); tok2 = tok2->next()) if (tok2->isTemplateArg() && tok2->str() == "const") { isTemplateArg = true; break; } if (isTemplateArg) continue; } if (func.isOperator()) { // Operator without return type: conversion operator const std::string& opName = func.tokenDef->str(); if (opName.compare(8, 5, "const") != 0 && (endsWith(opName,'&') || endsWith(opName,'*'))) continue; } else if (mSettings->library.isSmartPointer(func.retDef)) { // Don't warn if a std::shared_ptr etc is returned continue; } else { // don't warn for unknown types.. // LPVOID, HDC, etc if (func.retDef->str().size() > 2 && !func.retDef->type() && func.retDef->isUpperCaseName()) continue; } // check if base class function is virtual if (!scope->definedType->derivedFrom.empty() && func.isImplicitlyVirtual(true)) continue; enum MemberAccess memberAccessed = MemberAccess::NONE; // if nothing non-const was found. write error.. if (!checkConstFunc(scope, &func, memberAccessed)) continue; const bool suggestStatic = memberAccessed != MemberAccess::MEMBER && !func.isOperator(); if ((returnsPtrOrRef || func.isConst()) && !suggestStatic) continue; std::string classname = scope->className; const Scope *nest = scope->nestedIn; while (nest && nest->type != Scope::eGlobal) { classname = std::string(nest->className + "::" + classname); nest = nest->nestedIn; } // get function name std::string functionName = (func.tokenDef->isName() ? "" : "operator") + func.tokenDef->str(); if (func.tokenDef->str() == "(") functionName += ")"; else if (func.tokenDef->str() == "[") functionName += "]"; if (func.isInline()) checkConstError(func.token, classname, functionName, suggestStatic); else // not inline checkConstError2(func.token, func.tokenDef, classname, functionName, suggestStatic); } } } // tok should point at "this" static const Token* getFuncTokFromThis(const Token* tok) { if (!Token::simpleMatch(tok->next(), ".")) return nullptr; tok = tok->tokAt(2); while (Token::Match(tok, "%name% ::")) tok = tok->tokAt(2); return Token::Match(tok, "%name% (") ? tok : nullptr; } bool CheckClass::isMemberVar(const Scope *scope, const Token *tok) const { bool again = false; // try to find the member variable do { again = false; if (tok->str() == "this") return !getFuncTokFromThis(tok); // function calls are handled elsewhere if (Token::simpleMatch(tok->tokAt(-3), "( * this )")) return true; if (Token::Match(tok->tokAt(-3), "%name% ) . %name%")) { tok = tok->tokAt(-3); again = true; } else if (Token::Match(tok->tokAt(-2), "%name% . %name%")) { tok = tok->tokAt(-2); again = true; } else if (Token::Match(tok->tokAt(-2), "] . %name%")) { tok = tok->linkAt(-2)->previous(); again = true; } else if (tok->str() == "]") { tok = tok->link()->previous(); again = true; } } while (again); if (tok->isKeyword() || tok->isStandardType()) return false; for (const Variable& var : scope->varlist) { if (var.name() == tok->str()) { if (Token::Match(tok, "%name% ::")) continue; const Token* fqTok = tok; while (Token::Match(fqTok->tokAt(-2), "%name% ::")) fqTok = fqTok->tokAt(-2); if (fqTok->strAt(-1) == "::") fqTok = fqTok->previous(); bool isMember = tok == fqTok; std::string scopeStr; const Scope* curScope = scope; while (!isMember && curScope && curScope->type != Scope::ScopeType::eGlobal) { scopeStr.insert(0, curScope->className + " :: "); isMember = Token::Match(fqTok, scopeStr.c_str()); curScope = curScope->nestedIn; } if (isMember) { if (tok->varId() == 0) mSymbolDatabase->debugMessage(tok, "varid0", "CheckClass::isMemberVar found used member variable \'" + tok->str() + "\' with varid 0"); return !var.isStatic(); } } } // not found in this class if (!scope->definedType->derivedFrom.empty()) { // check each base class for (const Type::BaseInfo & i : scope->definedType->derivedFrom) { // find the base class const Type *derivedFrom = i.type; // find the function in the base class if (derivedFrom && derivedFrom->classScope && derivedFrom->classScope != scope) { if (isMemberVar(derivedFrom->classScope, tok)) return true; } } } return false; } bool CheckClass::isMemberFunc(const Scope *scope, const Token *tok) { if (!tok->function()) { for (const Function &func : scope->functionList) { if (func.name() == tok->str()) { const Token* tok2 = tok->tokAt(2); int argsPassed = tok2->str() == ")" ? 0 : 1; for (;;) { tok2 = tok2->nextArgument(); if (tok2) argsPassed++; else break; } if (argsPassed == func.argCount() || (func.isVariadic() && argsPassed >= (func.argCount() - 1)) || (argsPassed < func.argCount() && argsPassed >= func.minArgCount())) return true; } } } else if (tok->function()->nestedIn == scope) return !tok->function()->isStatic(); // not found in this class if (!scope->definedType->derivedFrom.empty()) { // check each base class for (const Type::BaseInfo & i : scope->definedType->derivedFrom) { // find the base class const Type *derivedFrom = i.type; // find the function in the base class if (derivedFrom && derivedFrom->classScope && derivedFrom->classScope != scope) { if (isMemberFunc(derivedFrom->classScope, tok)) return true; } } } return false; } bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok) { if (!tok->function()) return false; if (tok->function()->nestedIn == scope) return tok->function()->isConst(); // not found in this class if (!scope->definedType->derivedFrom.empty()) { // check each base class for (const Type::BaseInfo & i : scope->definedType->derivedFrom) { // find the base class const Type *derivedFrom = i.type; // find the function in the base class if (derivedFrom && derivedFrom->classScope) { if (isConstMemberFunc(derivedFrom->classScope, tok)) return true; } } } return false; } const std::set CheckClass::stl_containers_not_const = { "map", "unordered_map", "std :: map|unordered_map <" }; // start pattern bool CheckClass::checkConstFunc(const Scope *scope, const Function *func, MemberAccess& memberAccessed) const { if (mTokenizer->hasIfdef(func->functionScope->bodyStart, func->functionScope->bodyEnd)) return false; auto getFuncTok = [](const Token* tok) -> const Token* { if (Token::simpleMatch(tok, "this")) tok = getFuncTokFromThis(tok); bool isReturn = false; if ((Token::Match(tok, "%name% (|{") || (isReturn = Token::simpleMatch(tok->astParent(), "return {"))) && !tok->isStandardType() && !tok->isKeyword()) { if (isReturn) tok = tok->astParent(); return tok; } return nullptr; }; auto checkFuncCall = [this, &memberAccessed](const Token* funcTok, const Scope* scope, const Function* func) { if (isMemberFunc(scope, funcTok) && (funcTok->strAt(-1) != "." || Token::simpleMatch(funcTok->tokAt(-2), "this ."))) { const bool isSelf = func == funcTok->function(); if (!isConstMemberFunc(scope, funcTok) && !isSelf) return false; memberAccessed = (isSelf && memberAccessed != MemberAccess::MEMBER) ? MemberAccess::SELF : MemberAccess::MEMBER; } if (const Function* f = funcTok->function()) { // check known function const std::vector args = getArguments(funcTok); const auto argMax = std::min(args.size(), f->argCount()); for (nonneg int argIndex = 0; argIndex < argMax; ++argIndex) { const Variable* const argVar = f->getArgumentVar(argIndex); if (!argVar || ((argVar->isArrayOrPointer() || argVar->isReference()) && !(argVar->valueType() && argVar->valueType()->isConst(argVar->valueType()->pointer)))) { // argument might be modified const Token* arg = args[argIndex]; // Member variable given as parameter const Token* varTok = previousBeforeAstLeftmostLeaf(arg); if (!varTok) return false; varTok = varTok->next(); if ((varTok->isName() && isMemberVar(scope, varTok)) || (varTok->isUnaryOp("&") && (varTok = varTok->astOperand1()) && isMemberVar(scope, varTok))) { const Variable* var = varTok->variable(); if (!var || (!var->isMutable() && !var->isConst())) return false; } } } return true; } // Member variable given as parameter to unknown function const Token *lpar = funcTok->next(); if (Token::simpleMatch(lpar, "( ) (")) lpar = lpar->tokAt(2); for (const Token* tok = lpar->next(); tok && tok != funcTok->next()->link(); tok = tok->next()) { if (tok->str() == "(") tok = tok->link(); else if ((tok->isName() && isMemberVar(scope, tok)) || (tok->isUnaryOp("&") && (tok = tok->astOperand1()) && isMemberVar(scope, tok))) { const Variable* var = tok->variable(); if (!var || (!var->isMutable() && !var->isConst())) return false; } } return true; }; // if the function doesn't have any assignment nor function call, // it can be a const function.. for (const Token *tok1 = func->functionScope->bodyStart; tok1 && tok1 != func->functionScope->bodyEnd; tok1 = tok1->next()) { if (tok1->isName() && isMemberVar(scope, tok1)) { memberAccessed = MemberAccess::MEMBER; const Variable* v = tok1->variable(); if (v && v->isMutable()) continue; if (tok1->str() == "this") { if (tok1->previous()->isAssignmentOp()) return false; if (Token::Match(tok1->previous(), "( this . * %var% )")) // call using ptr to member function TODO: check constness return false; if (Token::simpleMatch(tok1->astParent(), "*") && tok1->astParent()->astParent() && tok1->astParent()->astParent()->isIncDecOp()) return false; } // non const pointer cast if (tok1->valueType() && tok1->valueType()->pointer > 0 && tok1->astParent() && tok1->astParent()->isCast() && !(tok1->astParent()->valueType() && (tok1->astParent()->valueType()->pointer == 0 || tok1->astParent()->valueType()->isConst(tok1->astParent()->valueType()->pointer)))) return false; const Token* lhs = tok1->previous(); if (lhs->str() == "(" && tok1->astParent() && tok1->astParent()->astParent()) lhs = tok1->astParent()->astParent(); else if (lhs->str() == "?" && lhs->astParent()) lhs = lhs->astParent(); else if (lhs->str() == ":" && lhs->astParent() && lhs->astParent()->astParent() && lhs->astParent()->str() == "?") lhs = lhs->astParent()->astParent(); if (lhs->str() == "&") { const Token* const top = lhs->astTop(); if (top->isAssignmentOp()) { if (Token::simpleMatch(top->astOperand2(), "{") && !top->astOperand2()->previous()->function()) // TODO: check usage in init list return false; if (top->previous()->variable()) { if (top->previous()->variable()->typeStartToken()->strAt(-1) != "const" && top->previous()->variable()->isPointer()) return false; } } } else if (lhs->str() == ":" && lhs->astParent() && lhs->astParent()->str() == "(") { // range-based for-loop (C++11) // TODO: We could additionally check what is done with the elements to avoid false negatives. Here we just rely on "const" keyword being used. if (lhs->astParent()->strAt(1) != "const") return false; } else { if (lhs->isAssignmentOp()) { const Variable* lhsVar = lhs->previous()->variable(); if (lhsVar && !lhsVar->isConst() && lhsVar->isReference() && lhs == lhsVar->nameToken()->next()) return false; } } const Token* jumpBackToken = nullptr; const Token *lastVarTok = tok1; const Token *end = tok1; for (;;) { if (Token::Match(end->next(), ". %name%")) { end = end->tokAt(2); if (end->varId()) lastVarTok = end; } else if (end->strAt(1) == "[") { if (end->varId()) { const Variable *var = end->variable(); if (var && var->isStlType(stl_containers_not_const)) return false; const Token* assignTok = end->next()->astParent(); if (var && assignTok && assignTok->isAssignmentOp() && assignTok->astOperand1() && assignTok->astOperand1()->variable()) { const Variable* assignVar = assignTok->astOperand1()->variable(); if (assignVar->isPointer() && !assignVar->isConst() && var->typeScope()) { const auto& funcMap = var->typeScope()->functionMap; // if there is no operator that is const and returns a non-const pointer, func cannot be const if (std::none_of(funcMap.cbegin(), funcMap.cend(), [](const std::pair& fm) { return fm.second->isConst() && fm.first == "operator[]" && !Function::returnsConst(fm.second); })) return false; } } } if (!jumpBackToken) jumpBackToken = end->next(); // Check inside the [] brackets end = end->linkAt(1); } else if (end->strAt(1) == ")") end = end->next(); else break; } auto hasOverloadedMemberAccess = [](const Token* end, const Scope* scope) -> bool { if (!end || !scope || !Token::simpleMatch(end->astParent(), ".")) return false; const std::string op = "operator" + end->astParent()->originalName(); auto it = std::find_if(scope->functionList.begin(), scope->functionList.end(), [&op](const Function& f) { return f.isConst() && f.name() == op; }); if (it == scope->functionList.end() || !it->retType || !it->retType->classScope) return false; const Function* func = it->retType->classScope->findFunction(end, /*requireConst*/ true); return func && func->isConst(); }; if (end->strAt(1) == "(") { const Variable *var = lastVarTok->variable(); if (!var) return false; if ((var->isStlType() // assume all std::*::size() and std::*::empty() are const && (Token::Match(end, "size|empty|cend|crend|cbegin|crbegin|max_size|length|count|capacity|get_allocator|c_str|str ( )") || Token::Match(end, "rfind|copy"))) || (lastVarTok->valueType() && lastVarTok->valueType()->container && ((lastVarTok->valueType()->container->getYield(end->str()) == Library::Container::Yield::START_ITERATOR) || (lastVarTok->valueType()->container->getYield(end->str()) == Library::Container::Yield::END_ITERATOR)) && (tok1->previous()->isComparisonOp() || (tok1->previous()->isAssignmentOp() && tok1->tokAt(-2)->variable() && Token::Match(tok1->tokAt(-2)->variable()->typeEndToken(), "const_iterator|const_reverse_iterator"))))) ; else if (var->smartPointerType() && var->smartPointerType()->classScope && isConstMemberFunc(var->smartPointerType()->classScope, end)) { ; } else if (var->isSmartPointer() && Token::simpleMatch(tok1->next(), ".") && tok1->next()->originalName().empty() && mSettings->library.isFunctionConst(end)) { ; } else if (hasOverloadedMemberAccess(end, var->typeScope())) { ; } else if (!var->typeScope() || (end->function() != func && !isConstMemberFunc(var->typeScope(), end))) return false; } // Assignment else if (end->next()->isAssignmentOp()) return false; // Streaming else if (end->strAt(1) == "<<" && tok1->strAt(-1) != "<<") return false; else if (isLikelyStreamRead(true, tok1->previous())) return false; // ++/-- else if (end->next()->tokType() == Token::eIncDecOp || tok1->previous()->tokType() == Token::eIncDecOp) return false; const Token* start = tok1; while (tok1->strAt(-1) == ")") tok1 = tok1->linkAt(-1); if (start->strAt(-1) == "delete") return false; tok1 = jumpBackToken?jumpBackToken:end; // Jump back to first [ to check inside, or jump to end of expression if (tok1 == end && Token::Match(end->previous(), ". %name% ( !!)") && !checkFuncCall(tok1, scope, func)) // function call on member return false; } // streaming: << else if (Token::simpleMatch(tok1->previous(), ") <<") && isMemberVar(scope, tok1->tokAt(-2))) { const Variable* var = tok1->tokAt(-2)->variable(); if (!var || !var->isMutable()) return false; } // streaming: >> *this else if (Token::simpleMatch(tok1, ">> * this") && isLikelyStreamRead(true, tok1)) { return false; } // function/constructor call, return init list else if (const Token* funcTok = getFuncTok(tok1)) { if (!checkFuncCall(funcTok, scope, func)) return false; } else if (Token::simpleMatch(tok1, "> (") && (!tok1->link() || !Token::Match(tok1->link()->previous(), "static_cast|const_cast|dynamic_cast|reinterpret_cast"))) { return false; } } return true; } void CheckClass::checkConstError(const Token *tok, const std::string &classname, const std::string &funcname, bool suggestStatic) { checkConstError2(tok, nullptr, classname, funcname, suggestStatic); } void CheckClass::checkConstError2(const Token *tok1, const Token *tok2, const std::string &classname, const std::string &funcname, bool suggestStatic) { std::list toks; toks.push_back(tok1); if (tok2) toks.push_back(tok2); if (!suggestStatic) reportError(toks, Severity::style, "functionConst", "$symbol:" + classname + "::" + funcname +"\n" "Technically the member function '$symbol' can be const.\n" "The member function '$symbol' can be made a const " "function. Making this function 'const' should not cause compiler errors. " "Even though the function can be made const function technically it may not make " "sense conceptually. Think about your design and the task of the function first - is " "it a function that must not change object internal state?", CWE398, Certainty::inconclusive); else reportError(toks, Severity::performance, "functionStatic", "$symbol:" + classname + "::" + funcname +"\n" "Technically the member function '$symbol' can be static (but you may consider moving to unnamed namespace).\n" "The member function '$symbol' can be made a static " "function. Making a function static can bring a performance benefit since no 'this' instance is " "passed to the function. This change should not cause compiler errors but it does not " "necessarily make sense conceptually. Think about your design and the task of the function first - " "is it a function that must not access members of class instances? And maybe it is more appropriate " "to move this function to an unnamed namespace.", CWE398, Certainty::inconclusive); } //--------------------------------------------------------------------------- // ClassCheck: Check that initializer list is in declared order. //--------------------------------------------------------------------------- namespace { // avoid one-definition-rule violation struct VarInfo { VarInfo(const Variable *_var, const Token *_tok) : var(_var), tok(_tok) {} const Variable *var; const Token *tok; }; } void CheckClass::initializerListOrder() { if (!mSettings->severity.isEnabled(Severity::style)) return; // This check is not inconclusive. However it only determines if the initialization // order is incorrect. It does not determine if being out of order causes // a real error. Out of order is not necessarily an error but you can never // have an error if the list is in order so this enforces defensive programming. if (!mSettings->certainty.isEnabled(Certainty::inconclusive)) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { // iterate through all member functions looking for constructors for (std::list::const_iterator func = scope->functionList.cbegin(); func != scope->functionList.cend(); ++func) { if (func->isConstructor() && func->hasBody()) { // check for initializer list const Token *tok = func->arg->link()->next(); if (tok->str() == ":") { std::vector vars; tok = tok->next(); // find all variable initializations in list while (tok && tok != func->functionScope->bodyStart) { if (Token::Match(tok, "%name% (|{")) { const Variable *var = scope->getVariable(tok->str()); if (var) vars.emplace_back(var, tok); if (Token::Match(tok->tokAt(2), "%name% =")) { var = scope->getVariable(tok->strAt(2)); if (var) vars.emplace_back(var, tok->tokAt(2)); } tok = tok->next()->link()->next(); } else tok = tok->next(); } // need at least 2 members to have out of order initialization for (int j = 1; j < vars.size(); j++) { // check for out of order initialization if (vars[j].var->index() < vars[j - 1].var->index()) initializerListError(vars[j].tok,vars[j].var->nameToken(), scope->className, vars[j].var->name()); } } } } } } void CheckClass::initializerListError(const Token *tok1, const Token *tok2, const std::string &classname, const std::string &varname) { std::list toks = { tok1, tok2 }; reportError(toks, Severity::style, "initializerList", "$symbol:" + classname + "::" + varname +"\n" "Member variable '$symbol' is in the wrong place in the initializer list.\n" "Member variable '$symbol' is in the wrong place in the initializer list. " "Members are initialized in the order they are declared, not in the " "order they are in the initializer list. Keeping the initializer list " "in the same order that the members were declared prevents order dependent " "initialization errors.", CWE398, Certainty::inconclusive); } //--------------------------------------------------------------------------- // Check for self initialization in initialization list //--------------------------------------------------------------------------- void CheckClass::checkSelfInitialization() { for (const Scope *scope : mSymbolDatabase->functionScopes) { const Function* function = scope->function; if (!function || !function->isConstructor()) continue; const Token* tok = function->arg->link()->next(); if (tok->str() != ":") continue; for (; tok != scope->bodyStart; tok = tok->next()) { if (Token::Match(tok, "[:,] %var% (|{")) { const Token* varTok = tok->next(); if (Token::Match(varTok->astParent(), "(|{")) { if (const Token* initTok = varTok->astParent()->astOperand2()) { if (initTok->varId() == varTok->varId()) selfInitializationError(tok, varTok->str()); else if (initTok->isCast() && ((initTok->astOperand1() && initTok->astOperand1()->varId() == varTok->varId()) || (initTok->astOperand2() && initTok->astOperand2()->varId() == varTok->varId()))) selfInitializationError(tok, varTok->str()); } } } } } } void CheckClass::selfInitializationError(const Token* tok, const std::string& varname) { reportError(tok, Severity::error, "selfInitialization", "$symbol:" + varname + "\nMember variable '$symbol' is initialized by itself.", CWE665, Certainty::normal); } //--------------------------------------------------------------------------- // Check for virtual function calls in constructor/destructor //--------------------------------------------------------------------------- void CheckClass::checkVirtualFunctionCallInConstructor() { if (!mSettings->severity.isEnabled(Severity::warning)) return; std::map> virtualFunctionCallsMap; for (const Scope *scope : mSymbolDatabase->functionScopes) { if (scope->function == nullptr || !scope->function->hasBody() || !(scope->function->isConstructor() || scope->function->isDestructor())) continue; const std::list & virtualFunctionCalls = getVirtualFunctionCalls(*scope->function, virtualFunctionCallsMap); for (const Token *callToken : virtualFunctionCalls) { std::list callstack(1, callToken); getFirstVirtualFunctionCallStack(virtualFunctionCallsMap, callToken, callstack); if (callstack.empty()) continue; const Function* const func = callstack.back()->function(); if (!(func->hasVirtualSpecifier() || func->hasOverrideSpecifier())) continue; if (func->isPure()) pureVirtualFunctionCallInConstructorError(scope->function, callstack, callstack.back()->str()); else if (!func->hasFinalSpecifier() && !(func->nestedIn && func->nestedIn->classDef && func->nestedIn->classDef->isFinalType())) virtualFunctionCallInConstructorError(scope->function, callstack, callstack.back()->str()); } } } const std::list & CheckClass::getVirtualFunctionCalls(const Function & function, std::map> & virtualFunctionCallsMap) { const std::map>::const_iterator found = virtualFunctionCallsMap.find(&function); if (found != virtualFunctionCallsMap.end()) return found->second; virtualFunctionCallsMap[&function] = std::list(); std::list & virtualFunctionCalls = virtualFunctionCallsMap.find(&function)->second; if (!function.hasBody() || !function.functionScope) return virtualFunctionCalls; for (const Token *tok = function.arg->link(); tok != function.functionScope->bodyEnd; tok = tok->next()) { if (function.type != Function::eConstructor && function.type != Function::eCopyConstructor && function.type != Function::eMoveConstructor && function.type != Function::eDestructor) { if ((Token::simpleMatch(tok, ") {") && tok->link() && Token::Match(tok->link()->previous(), "if|switch")) || Token::simpleMatch(tok, "else {")) { // Assume pure virtual function call is prevented by "if|else|switch" condition tok = tok->linkAt(1); continue; } } if (tok->scope()->type == Scope::eLambda) tok = tok->scope()->bodyEnd->next(); const Function * callFunction = tok->function(); if (!callFunction || function.nestedIn != callFunction->nestedIn || Token::simpleMatch(tok->previous(), ".") || !(tok->astParent() && (tok->astParent()->str() == "(" || (tok->astParent()->str() == "::" && Token::simpleMatch(tok->astParent()->astParent(), "("))))) continue; if (tok->previous() && tok->previous()->str() == "(") { const Token * prev = tok->previous(); if (prev->previous() && (mSettings->library.ignorefunction(tok->str()) || mSettings->library.ignorefunction(prev->previous()->str()))) continue; } if (callFunction->isImplicitlyVirtual()) { if (!callFunction->isPure() && Token::simpleMatch(tok->previous(), "::")) continue; virtualFunctionCalls.push_back(tok); continue; } const std::list & virtualFunctionCallsOfTok = getVirtualFunctionCalls(*callFunction, virtualFunctionCallsMap); if (!virtualFunctionCallsOfTok.empty()) virtualFunctionCalls.push_back(tok); } return virtualFunctionCalls; } void CheckClass::getFirstVirtualFunctionCallStack( std::map> & virtualFunctionCallsMap, const Token * callToken, std::list & pureFuncStack) { const Function *callFunction = callToken->function(); if (callFunction->isImplicitlyVirtual() && (!callFunction->isPure() || !callFunction->hasBody())) { pureFuncStack.push_back(callFunction->tokenDef); return; } std::map>::const_iterator found = virtualFunctionCallsMap.find(callFunction); if (found == virtualFunctionCallsMap.cend() || found->second.empty()) { pureFuncStack.clear(); return; } const Token * firstCall = *found->second.cbegin(); pureFuncStack.push_back(firstCall); getFirstVirtualFunctionCallStack(virtualFunctionCallsMap, firstCall, pureFuncStack); } void CheckClass::virtualFunctionCallInConstructorError( const Function * scopeFunction, const std::list & tokStack, const std::string &funcname) { const char * scopeFunctionTypeName = scopeFunction ? getFunctionTypeName(scopeFunction->type) : "constructor"; ErrorPath errorPath; std::transform(tokStack.cbegin(), tokStack.cend(), std::back_inserter(errorPath), [](const Token* tok) { return ErrorPathItem(tok, "Calling " + tok->str()); }); int lineNumber = 1; if (!errorPath.empty()) { lineNumber = errorPath.front().first->linenr(); errorPath.back().second = funcname + " is a virtual function"; } std::string constructorName; if (scopeFunction) { const Token *endToken = scopeFunction->argDef->link()->next(); if (scopeFunction->type == Function::Type::eDestructor) constructorName = "~"; for (const Token *tok = scopeFunction->tokenDef; tok != endToken; tok = tok->next()) { if (!constructorName.empty() && Token::Match(tok->previous(), "%name%|%num% %name%|%num%")) constructorName += ' '; constructorName += tok->str(); if (tok->str() == ")") break; } } reportError(errorPath, Severity::style, "virtualCallInConstructor", "Virtual function '" + funcname + "' is called from " + scopeFunctionTypeName + " '" + constructorName + "' at line " + MathLib::toString(lineNumber) + ". Dynamic binding is not used.", CWE(0U), Certainty::normal); } void CheckClass::pureVirtualFunctionCallInConstructorError( const Function * scopeFunction, const std::list & tokStack, const std::string &purefuncname) { const char * scopeFunctionTypeName = scopeFunction ? getFunctionTypeName(scopeFunction->type) : "constructor"; ErrorPath errorPath; std::transform(tokStack.cbegin(), tokStack.cend(), std::back_inserter(errorPath), [](const Token* tok) { return ErrorPathItem(tok, "Calling " + tok->str()); }); if (!errorPath.empty()) errorPath.back().second = purefuncname + " is a pure virtual function without body"; reportError(errorPath, Severity::warning, "pureVirtualCall", "$symbol:" + purefuncname +"\n" "Call of pure virtual function '$symbol' in " + scopeFunctionTypeName + ".\n" "Call of pure virtual function '$symbol' in " + scopeFunctionTypeName + ". The call will fail during runtime.", CWE(0U), Certainty::normal); } //--------------------------------------------------------------------------- // Check for members hiding inherited members with the same name //--------------------------------------------------------------------------- void CheckClass::checkDuplInheritedMembers() { if (!mSettings->severity.isEnabled(Severity::warning)) return; // Iterate over all classes for (const Type &classIt : mSymbolDatabase->typeList) { // Iterate over the parent classes checkDuplInheritedMembersRecursive(&classIt, &classIt); } } namespace { struct DuplMemberInfo { DuplMemberInfo(const Variable* cv, const Variable* pcv, const Type::BaseInfo* pc) : classVar(cv), parentClassVar(pcv), parentClass(pc) {} const Variable* classVar; const Variable* parentClassVar; const Type::BaseInfo* parentClass; }; struct DuplMemberFuncInfo { DuplMemberFuncInfo(const Function* cf, const Function* pcf, const Type::BaseInfo* pc) : classFunc(cf), parentClassFunc(pcf), parentClass(pc) {} const Function* classFunc; const Function* parentClassFunc; const Type::BaseInfo* parentClass; }; } static std::vector getDuplInheritedMembersRecursive(const Type* typeCurrent, const Type* typeBase, bool skipPrivate = true) { std::vector results; for (const Type::BaseInfo &parentClassIt : typeBase->derivedFrom) { // Check if there is info about the 'Base' class if (!parentClassIt.type || !parentClassIt.type->classScope) continue; // Don't crash on recursive templates if (parentClassIt.type == typeBase) continue; // Check if they have a member variable in common for (const Variable &classVarIt : typeCurrent->classScope->varlist) { for (const Variable &parentClassVarIt : parentClassIt.type->classScope->varlist) { if (classVarIt.name() == parentClassVarIt.name() && (!parentClassVarIt.isPrivate() || !skipPrivate)) // Check if the class and its parent have a common variable results.emplace_back(&classVarIt, &parentClassVarIt, &parentClassIt); } } if (typeCurrent != parentClassIt.type) { const auto recursive = getDuplInheritedMembersRecursive(typeCurrent, parentClassIt.type, skipPrivate); results.insert(results.end(), recursive.begin(), recursive.end()); } } return results; } static std::vector getDuplInheritedMemberFunctionsRecursive(const Type* typeCurrent, const Type* typeBase, bool skipPrivate = true) { std::vector results; for (const Type::BaseInfo &parentClassIt : typeBase->derivedFrom) { // Check if there is info about the 'Base' class if (!parentClassIt.type || !parentClassIt.type->classScope) continue; // Don't crash on recursive templates if (parentClassIt.type == typeBase) continue; for (const Function& classFuncIt : typeCurrent->classScope->functionList) { if (classFuncIt.isImplicitlyVirtual()) continue; for (const Function& parentClassFuncIt : parentClassIt.type->classScope->functionList) { if (classFuncIt.name() == parentClassFuncIt.name() && (parentClassFuncIt.access != AccessControl::Private || !skipPrivate) && !classFuncIt.isConstructor() && !classFuncIt.isDestructor() && classFuncIt.argsMatch(parentClassIt.type->classScope, parentClassFuncIt.argDef, classFuncIt.argDef, emptyString, 0)) results.emplace_back(&classFuncIt, &parentClassFuncIt, &parentClassIt); } } if (typeCurrent != parentClassIt.type) { const auto recursive = getDuplInheritedMemberFunctionsRecursive(typeCurrent, parentClassIt.type); results.insert(results.end(), recursive.begin(), recursive.end()); } } return results; } void CheckClass::checkDuplInheritedMembersRecursive(const Type* typeCurrent, const Type* typeBase) { const auto resultsVar = getDuplInheritedMembersRecursive(typeCurrent, typeBase); for (const auto& r : resultsVar) { duplInheritedMembersError(r.classVar->nameToken(), r.parentClassVar->nameToken(), typeCurrent->name(), r.parentClass->type->name(), r.classVar->name(), typeCurrent->classScope->type == Scope::eStruct, r.parentClass->type->classScope->type == Scope::eStruct); } const auto resultsFunc = getDuplInheritedMemberFunctionsRecursive(typeCurrent, typeBase); for (const auto& r : resultsFunc) { duplInheritedMembersError(r.classFunc->token, r.parentClassFunc->token, typeCurrent->name(), r.parentClass->type->name(), r.classFunc->name(), typeCurrent->classScope->type == Scope::eStruct, r.parentClass->type->classScope->type == Scope::eStruct, /*isFunction*/ true); } } void CheckClass::duplInheritedMembersError(const Token *tok1, const Token* tok2, const std::string &derivedName, const std::string &baseName, const std::string &memberName, bool derivedIsStruct, bool baseIsStruct, bool isFunction) { ErrorPath errorPath; const std::string member = isFunction ? "function" : "variable"; errorPath.emplace_back(tok2, "Parent " + member + " '" + baseName + "::" + memberName + "'"); errorPath.emplace_back(tok1, "Derived " + member + " '" + derivedName + "::" + memberName + "'"); const std::string symbols = "$symbol:" + derivedName + "\n$symbol:" + memberName + "\n$symbol:" + baseName; const std::string message = "The " + std::string(derivedIsStruct ? "struct" : "class") + " '" + derivedName + "' defines member " + member + " with name '" + memberName + "' also defined in its parent " + std::string(baseIsStruct ? "struct" : "class") + " '" + baseName + "'."; reportError(errorPath, Severity::warning, "duplInheritedMember", symbols + '\n' + message, CWE398, Certainty::normal); } //--------------------------------------------------------------------------- // Check that copy constructor and operator defined together //--------------------------------------------------------------------------- enum class CtorType { NO, WITHOUT_BODY, WITH_BODY }; void CheckClass::checkCopyCtorAndEqOperator() { // This is disabled because of #8388 // The message must be clarified. How is the behaviour different? // cppcheck-suppress unreachableCode - remove when code is enabled again if ((true) || !mSettings->severity.isEnabled(Severity::warning)) // NOLINT(readability-simplify-boolean-expr) return; for (const Scope * scope : mSymbolDatabase->classAndStructScopes) { const bool hasNonStaticVars = std::any_of(scope->varlist.begin(), scope->varlist.end(), [](const Variable& var) { return !var.isStatic(); }); if (!hasNonStaticVars) continue; CtorType copyCtors = CtorType::NO; bool moveCtor = false; CtorType assignmentOperators = CtorType::NO; for (const Function &func : scope->functionList) { if (copyCtors == CtorType::NO && func.type == Function::eCopyConstructor) { copyCtors = func.hasBody() ? CtorType::WITH_BODY : CtorType::WITHOUT_BODY; } if (assignmentOperators == CtorType::NO && func.type == Function::eOperatorEqual) { const Variable * variable = func.getArgumentVar(0); if (variable && variable->type() && variable->type()->classScope == scope) { assignmentOperators = func.hasBody() ? CtorType::WITH_BODY : CtorType::WITHOUT_BODY; } } if (func.type == Function::eMoveConstructor) { moveCtor = true; break; } } if (moveCtor) continue; // No method defined if (copyCtors != CtorType::WITH_BODY && assignmentOperators != CtorType::WITH_BODY) continue; // both methods are defined if (copyCtors != CtorType::NO && assignmentOperators != CtorType::NO) continue; copyCtorAndEqOperatorError(scope->classDef, scope->className, scope->type == Scope::eStruct, copyCtors == CtorType::WITH_BODY); } } void CheckClass::copyCtorAndEqOperatorError(const Token *tok, const std::string &classname, bool isStruct, bool hasCopyCtor) { const std::string message = "$symbol:" + classname + "\n" "The " + std::string(isStruct ? "struct" : "class") + " '$symbol' has '" + getFunctionTypeName(hasCopyCtor ? Function::eCopyConstructor : Function::eOperatorEqual) + "' but lack of '" + getFunctionTypeName(hasCopyCtor ? Function::eOperatorEqual : Function::eCopyConstructor) + "'."; reportError(tok, Severity::warning, "copyCtorAndEqOperator", message); } void CheckClass::checkOverride() { if (!mSettings->severity.isEnabled(Severity::style)) return; if (mSettings->standards.cpp < Standards::CPP11) return; for (const Scope * classScope : mSymbolDatabase->classAndStructScopes) { if (!classScope->definedType || classScope->definedType->derivedFrom.empty()) continue; for (const Function &func : classScope->functionList) { if (func.hasOverrideSpecifier() || func.hasFinalSpecifier()) continue; const Function *baseFunc = func.getOverriddenFunction(); if (baseFunc) overrideError(baseFunc, &func); } } } void CheckClass::overrideError(const Function *funcInBase, const Function *funcInDerived) { const std::string functionName = funcInDerived ? ((funcInDerived->isDestructor() ? "~" : "") + funcInDerived->name()) : ""; const std::string funcType = (funcInDerived && funcInDerived->isDestructor()) ? "destructor" : "function"; ErrorPath errorPath; if (funcInBase && funcInDerived) { errorPath.emplace_back(funcInBase->tokenDef, "Virtual " + funcType + " in base class"); errorPath.emplace_back(funcInDerived->tokenDef, char(std::toupper(funcType[0])) + funcType.substr(1) + " in derived class"); } reportError(errorPath, Severity::style, "missingOverride", "$symbol:" + functionName + "\n" "The " + funcType + " '$symbol' overrides a " + funcType + " in a base class but is not marked with a 'override' specifier.", CWE(0U) /* Unknown CWE! */, Certainty::normal); } void CheckClass::uselessOverrideError(const Function *funcInBase, const Function *funcInDerived, bool isSameCode) { const std::string functionName = funcInDerived ? ((funcInDerived->isDestructor() ? "~" : "") + funcInDerived->name()) : ""; const std::string funcType = (funcInDerived && funcInDerived->isDestructor()) ? "destructor" : "function"; ErrorPath errorPath; if (funcInBase && funcInDerived) { errorPath.emplace_back(funcInBase->tokenDef, "Virtual " + funcType + " in base class"); errorPath.emplace_back(funcInDerived->tokenDef, char(std::toupper(funcType[0])) + funcType.substr(1) + " in derived class"); } std::string errStr = "\nThe " + funcType + " '$symbol' overrides a " + funcType + " in a base class but "; if (isSameCode) { errStr += "is identical to the overridden function"; } else errStr += "just delegates back to the base class."; reportError(errorPath, Severity::style, "uselessOverride", "$symbol:" + functionName + errStr, CWE(0U) /* Unknown CWE! */, Certainty::normal); } static const Token* getSingleFunctionCall(const Scope* scope) { const Token* const start = scope->bodyStart->next(); const Token* const end = Token::findsimplematch(start, ";", 1, scope->bodyEnd); if (!end || end->next() != scope->bodyEnd) return nullptr; const Token* ftok = start; if (ftok->str() == "return") ftok = ftok->astOperand1(); else { while (Token::Match(ftok, "%name%|::")) ftok = ftok->next(); } if (Token::simpleMatch(ftok, "(") && ftok->previous()->function()) return ftok->previous(); return nullptr; } static bool compareTokenRanges(const Token* start1, const Token* end1, const Token* start2, const Token* end2) { const Token* tok1 = start1; const Token* tok2 = start2; bool isEqual = false; while (tok1 && tok2) { if (tok1->str() != tok2->str()) break; if (tok1->str() == "this") break; if (tok1->isExpandedMacro() || tok2->isExpandedMacro()) break; if (tok1 == end1 && tok2 == end2) { isEqual = true; break; } tok1 = tok1->next(); tok2 = tok2->next(); } return isEqual; } void CheckClass::checkUselessOverride() { if (!mSettings->severity.isEnabled(Severity::style)) return; for (const Scope* classScope : mSymbolDatabase->classAndStructScopes) { if (!classScope->definedType || classScope->definedType->derivedFrom.size() != 1) continue; for (const Function& func : classScope->functionList) { if (!func.functionScope) continue; if (func.hasFinalSpecifier()) continue; const Function* baseFunc = func.getOverriddenFunction(); if (!baseFunc || baseFunc->isPure() || baseFunc->access != func.access) continue; if (std::any_of(classScope->functionList.begin(), classScope->functionList.end(), [&func](const Function& f) { // check for overloads if (&f == &func) return false; return f.name() == func.name(); })) continue; if (func.token->isExpandedMacro() || baseFunc->token->isExpandedMacro()) continue; if (baseFunc->functionScope) { bool isSameCode = compareTokenRanges(baseFunc->argDef, baseFunc->argDef->link(), func.argDef, func.argDef->link()); // function arguments if (isSameCode) { isSameCode = compareTokenRanges(baseFunc->functionScope->bodyStart, baseFunc->functionScope->bodyEnd, // function body func.functionScope->bodyStart, func.functionScope->bodyEnd); if (isSameCode) { // bailout for shadowed members if (!classScope->definedType || !getDuplInheritedMembersRecursive(classScope->definedType, classScope->definedType, /*skipPrivate*/ false).empty() || !getDuplInheritedMemberFunctionsRecursive(classScope->definedType, classScope->definedType, /*skipPrivate*/ false).empty()) continue; uselessOverrideError(baseFunc, &func, true); continue; } } } if (const Token* const call = getSingleFunctionCall(func.functionScope)) { if (call->function() != baseFunc) continue; std::vector funcArgs = getArguments(func.tokenDef); std::vector callArgs = getArguments(call); if (funcArgs.size() != callArgs.size() || !std::equal(funcArgs.begin(), funcArgs.end(), callArgs.begin(), [](const Token* t1, const Token* t2) { return t1->str() == t2->str(); })) continue; uselessOverrideError(baseFunc, &func); } } } } void CheckClass::checkThisUseAfterFree() { if (!mSettings->severity.isEnabled(Severity::warning)) return; for (const Scope * classScope : mSymbolDatabase->classAndStructScopes) { for (const Variable &var : classScope->varlist) { // Find possible "self pointer".. pointer/smartpointer member variable of "self" type. if (var.valueType() && var.valueType()->smartPointerType != classScope->definedType && var.valueType()->typeScope != classScope) { const ValueType valueType = ValueType::parseDecl(var.typeStartToken(), *mSettings, true); // this is only called for C++ if (valueType.smartPointerType != classScope->definedType) continue; } // If variable is not static, check that "this" is assigned if (!var.isStatic()) { bool hasAssign = false; for (const Function &func : classScope->functionList) { if (func.type != Function::Type::eFunction || !func.hasBody()) continue; for (const Token *tok = func.functionScope->bodyStart; tok != func.functionScope->bodyEnd; tok = tok->next()) { if (Token::Match(tok, "%varid% = this|shared_from_this", var.declarationId())) { hasAssign = true; break; } } if (hasAssign) break; } if (!hasAssign) continue; } // Check usage of self pointer.. for (const Function &func : classScope->functionList) { if (func.type != Function::Type::eFunction || !func.hasBody()) continue; const Token * freeToken = nullptr; std::set callstack; checkThisUseAfterFreeRecursive(classScope, &func, &var, callstack, &freeToken); } } } } bool CheckClass::checkThisUseAfterFreeRecursive(const Scope *classScope, const Function *func, const Variable *selfPointer, std::set callstack, const Token **freeToken) { if (!func || !func->functionScope) return false; // avoid recursion if (callstack.count(func)) return false; callstack.insert(func); const Token * const bodyStart = func->functionScope->bodyStart; const Token * const bodyEnd = func->functionScope->bodyEnd; for (const Token *tok = bodyStart; tok != bodyEnd; tok = tok->next()) { const bool isDestroyed = *freeToken != nullptr && !func->isStatic(); if (Token::Match(tok, "delete %var% ;") && selfPointer == tok->next()->variable()) { *freeToken = tok; tok = tok->tokAt(2); } else if (Token::Match(tok, "%var% . reset ( )") && selfPointer == tok->variable()) *freeToken = tok; else if (Token::Match(tok->previous(), "!!. %name% (") && tok->function() && tok->function()->nestedIn == classScope) { if (isDestroyed) { thisUseAfterFree(selfPointer->nameToken(), *freeToken, tok); return true; } if (checkThisUseAfterFreeRecursive(classScope, tok->function(), selfPointer, callstack, freeToken)) return true; } else if (isDestroyed && Token::Match(tok->previous(), "!!. %name%") && tok->variable() && tok->variable()->scope() == classScope && !tok->variable()->isStatic() && !tok->variable()->isArgument()) { thisUseAfterFree(selfPointer->nameToken(), *freeToken, tok); return true; } else if (*freeToken && Token::Match(tok, "return|throw")) { // TODO return tok->str() == "throw"; } else if (tok->str() == "{" && tok->scope()->type == Scope::ScopeType::eLambda) { tok = tok->link(); } } return false; } void CheckClass::thisUseAfterFree(const Token *self, const Token *free, const Token *use) { std::string selfPointer = self ? self->str() : "ptr"; const ErrorPath errorPath = { ErrorPathItem(self, "Assuming '" + selfPointer + "' is used as 'this'"), ErrorPathItem(free, "Delete '" + selfPointer + "', invalidating 'this'"), ErrorPathItem(use, "Call method when 'this' is invalid") }; const std::string usestr = use ? use->str() : "x"; const std::string usemsg = use && use->function() ? ("Calling method '" + usestr + "()'") : ("Using member '" + usestr + "'"); reportError(errorPath, Severity::warning, "thisUseAfterFree", "$symbol:" + selfPointer + "\n" + usemsg + " when 'this' might be invalid", CWE(0), Certainty::normal); } void CheckClass::checkUnsafeClassRefMember() { if (!mSettings->safeChecks.classes || !mSettings->severity.isEnabled(Severity::warning)) return; for (const Scope * classScope : mSymbolDatabase->classAndStructScopes) { for (const Function &func : classScope->functionList) { if (!func.hasBody() || !func.isConstructor()) continue; const Token *initList = func.constructorMemberInitialization(); while (Token::Match(initList, "[:,] %name% (")) { if (Token::Match(initList->tokAt(2), "( %var% )")) { const Variable * const memberVar = initList->next()->variable(); const Variable * const argVar = initList->tokAt(3)->variable(); if (memberVar && argVar && memberVar->isConst() && memberVar->isReference() && argVar->isArgument() && argVar->isConst() && argVar->isReference()) unsafeClassRefMemberError(initList->next(), classScope->className + "::" + memberVar->name()); } initList = initList->linkAt(2)->next(); } } } } void CheckClass::unsafeClassRefMemberError(const Token *tok, const std::string &varname) { reportError(tok, Severity::warning, "unsafeClassRefMember", "$symbol:" + varname + "\n" "Unsafe class: The const reference member '$symbol' is initialized by a const reference constructor argument. You need to be careful about lifetime issues.\n" "Unsafe class checking: The const reference member '$symbol' is initialized by a const reference constructor argument. You need to be careful about lifetime issues. If you pass a local variable or temporary value in this constructor argument, be extra careful. If the argument is always some global object that is never destroyed then this is safe usage. However it would be defensive to make the member '$symbol' a non-reference variable or a smart pointer.", CWE(0), Certainty::normal); } Check::FileInfo *CheckClass::getFileInfo(const Tokenizer *tokenizer, const Settings *settings) const { if (!tokenizer->isCPP()) return nullptr; (void)settings; // One definition rule std::vector classDefinitions; for (const Scope * classScope : tokenizer->getSymbolDatabase()->classAndStructScopes) { if (classScope->isAnonymous()) continue; if (classScope->classDef && Token::simpleMatch(classScope->classDef->previous(), ">")) continue; // the full definition must be compared const bool fullDefinition = std::all_of(classScope->functionList.cbegin(), classScope->functionList.cend(), [](const Function& f) { return f.hasBody(); }); if (!fullDefinition) continue; std::string name; const Scope *scope = classScope; while (scope->isClassOrStruct() && !classScope->className.empty()) { if (Token::Match(scope->classDef, "struct|class %name% :: %name%")) { // TODO handle such classnames name.clear(); break; } name = scope->className + "::" + name; scope = scope->nestedIn; } if (name.empty()) continue; name.erase(name.size() - 2); if (scope->type != Scope::ScopeType::eGlobal) continue; MyFileInfo::NameLoc nameLoc; nameLoc.className = name; nameLoc.fileName = tokenizer->list.file(classScope->classDef); nameLoc.lineNumber = classScope->classDef->linenr(); nameLoc.column = classScope->classDef->column(); // Calculate hash from the full class/struct definition std::string def; for (const Token *tok = classScope->classDef; tok != classScope->bodyEnd; tok = tok->next()) def += tok->str(); for (const Function &f: classScope->functionList) { if (f.functionScope && f.functionScope->nestedIn != classScope) { for (const Token *tok = f.functionScope->bodyStart; tok != f.functionScope->bodyEnd; tok = tok->next()) def += tok->str(); } } nameLoc.hash = std::hash {}(def); classDefinitions.push_back(std::move(nameLoc)); } if (classDefinitions.empty()) return nullptr; MyFileInfo *fileInfo = new MyFileInfo; fileInfo->classDefinitions.swap(classDefinitions); return fileInfo; } std::string CheckClass::MyFileInfo::toString() const { std::string ret; for (const MyFileInfo::NameLoc &nameLoc: classDefinitions) { ret += "\n"; } return ret; } Check::FileInfo * CheckClass::loadFileInfoFromXml(const tinyxml2::XMLElement *xmlElement) const { MyFileInfo *fileInfo = new MyFileInfo; for (const tinyxml2::XMLElement *e = xmlElement->FirstChildElement(); e; e = e->NextSiblingElement()) { if (std::strcmp(e->Name(), "class") != 0) continue; const char *name = e->Attribute("name"); const char *file = e->Attribute("file"); const char *line = e->Attribute("line"); const char *col = e->Attribute("col"); const char *hash = e->Attribute("hash"); if (name && file && line && col && hash) { MyFileInfo::NameLoc nameLoc; nameLoc.className = name; nameLoc.fileName = file; nameLoc.lineNumber = strToInt(line); nameLoc.column = strToInt(col); nameLoc.hash = strToInt(hash); fileInfo->classDefinitions.push_back(std::move(nameLoc)); } } if (fileInfo->classDefinitions.empty()) { delete fileInfo; fileInfo = nullptr; } return fileInfo; } bool CheckClass::analyseWholeProgram(const CTU::FileInfo *ctu, const std::list &fileInfo, const Settings& settings, ErrorLogger &errorLogger) { bool foundErrors = false; (void)ctu; // This argument is unused (void)settings; // This argument is unused std::unordered_map all; for (const Check::FileInfo* fi1 : fileInfo) { const MyFileInfo *fi = dynamic_cast(fi1); if (!fi) continue; for (const MyFileInfo::NameLoc &nameLoc : fi->classDefinitions) { auto it = all.find(nameLoc.className); if (it == all.end()) { all[nameLoc.className] = nameLoc; continue; } if (it->second.hash == nameLoc.hash) continue; // Same location, sometimes the hash is different wrongly (possibly because of different token simplifications). if (it->second.isSameLocation(nameLoc)) continue; std::list locationList; locationList.emplace_back(nameLoc.fileName, nameLoc.lineNumber, nameLoc.column); locationList.emplace_back(it->second.fileName, it->second.lineNumber, it->second.column); const ErrorMessage errmsg(locationList, emptyString, Severity::error, "$symbol:" + nameLoc.className + "\nThe one definition rule is violated, different classes/structs have the same name '$symbol'", "ctuOneDefinitionRuleViolation", CWE_ONE_DEFINITION_RULE, Certainty::normal); errorLogger.reportErr(errmsg); foundErrors = true; } } return foundErrors; }