/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2018 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 "errorlogger.h"
#include "library.h"
#include "settings.h"
#include "standards.h"
#include "symboldatabase.h"
#include "token.h"
#include "tokenize.h"
#include "utils.h"
#include
#include
#include
#include
//---------------------------------------------------------------------------
// 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 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=";
}
return "";
}
static bool isVariableCopyNeeded(const Variable &var)
{
return var.isPointer() || (var.type() && var.type()->needInitialization == Type::True) || (var.valueType()->type >= ValueType::Type::CHAR);
}
//---------------------------------------------------------------------------
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->isEnabled(Settings::STYLE);
const bool printWarnings = mSettings->isEnabled(Settings::WARNING);
if (!printStyle && !printWarnings)
return;
const bool printInconclusive = mSettings->inconclusive;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
bool usedInUnion = false;
for (const Scope &unionScope : mSymbolDatabase->scopeList) {
if (unionScope.type != Scope::eUnion)
continue;
for (const Variable &var : unionScope.varlist) {
if (var.type() && var.type()->classScope == scope) {
usedInUnion = true;
break;
}
}
}
// There are no constructors.
if (scope->numConstructors == 0 && printStyle && !usedInUnion) {
// If there is a private variable, there should be a constructor..
for (const Variable &var : scope->varlist) {
if (var.isPrivate() && !var.isStatic() && !Token::Match(var.nameToken(), "%varid% ; %varid% =", var.declarationId()) &&
(!var.isClass() || (var.type() && var.type()->needInitialization == Type::True))) {
noConstructorError(scope->classDef, scope->className, scope->classDef->str() == "struct");
break;
}
}
}
if (!printWarnings)
continue;
// #3196 => bailout if there are nested unions
// TODO: handle union variables better
{
bool bailout = false;
for (const Scope * const nestedScope : scope->nestedList) {
if (nestedScope->type == Scope::eUnion) {
bailout = true;
break;
}
}
if (bailout)
continue;
}
std::vector usage(scope->varlist.size());
for (const Function &func : scope->functionList) {
if (!func.hasBody() || !(func.isConstructor() || func.type == Function::eOperatorEqual))
continue;
// Mark all variables not used
clearAllVar(usage);
std::list callstack;
initializeVarList(func, callstack, scope, usage);
// Check if any variables are uninitialized
int count = -1;
for (const Variable &var : scope->varlist) {
++count;
// check for C++11 initializer
if (var.hasDefault()) {
usage[count].init = true;
continue;
}
if (usage[count].assign || usage[count].init || var.isStatic())
continue;
if (var.valueType()->pointer == 0 && var.type() && var.type()->needInitialization == Type::False)
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())
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::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;
}
}
bool inconclusive = false;
// Don't warn about unknown types in copy constructors since we
// don't know if they can be copied or not..
if ((func.type == Function::eCopyConstructor || func.type == Function::eOperatorEqual) && !isVariableCopyNeeded(var))
inconclusive = true;
if (!printInconclusive && inconclusive)
continue;
// 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)
operatorEqVarError(func.token, scope->className, var.name(), inconclusive);
} else if (func.access != Private || mSettings->standards.cpp >= Standards::CPP11) {
const Scope *varType = var.typeScope();
if (!varType || varType->type != Scope::eUnion) {
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 == Private, scope->className, var.name(), true);
} else
uninitVarError(func.token, func.access == Private, scope->className, var.name(), inconclusive);
}
}
}
}
}
}
void CheckClass::checkExplicitConstructors()
{
if (!mSettings->isEnabled(Settings::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.
bool isAbstractClass = false;
for (const Function &func : scope->functionList) {
if (func.isPure()) {
isAbstractClass = true;
break;
}
}
// 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 == Private))
continue;
if (!func.isExplicit() &&
func.argCount() == 1 &&
func.type != Function::eCopyConstructor &&
func.type != Function::eMoveConstructor) {
noExplicitConstructorError(func.tokenDef, scope->className, scope->type == Scope::eStruct);
}
}
}
}
static bool isNonCopyable(const Scope *scope, bool *unknown)
{
bool u = false;
// check if there is base class that is not copyable
for (const Type::BaseInfo &baseInfo : scope->definedType->derivedFrom) {
if (!baseInfo.type || !baseInfo.type->classScope) {
u = true;
continue;
}
if (isNonCopyable(baseInfo.type->classScope, &u))
return true;
for (const Function &func : baseInfo.type->classScope->functionList) {
if (func.type != Function::eCopyConstructor)
continue;
if (func.access == Private || func.isDelete())
return true;
}
}
*unknown = u;
return false;
}
void CheckClass::copyconstructors()
{
if (!mSettings->isEnabled(Settings::STYLE))
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.alloc(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.alloc(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 (!isNonCopyable(scope, &unknown) && !unknown)
noCopyConstructorError(scope, funcCopyCtor, allocatedVars.begin()->second, unknown);
}
if (!funcOperatorEq || funcOperatorEq->isDefault()) {
bool unknown = false;
if (!isNonCopyable(scope, &unknown) && !unknown)
noOperatorEqError(scope, funcOperatorEq, allocatedVars.begin()->second, unknown);
}
if (!funcDestructor || funcDestructor->isDefault()) {
const Token * mustDealloc = nullptr;
for (std::map::const_iterator it = allocatedVars.begin(); it != allocatedVars.end(); ++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;
}
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 (Token::Match(tok, "%var% = new|malloc|g_malloc|g_try_malloc|realloc|g_realloc|g_try_realloc")) {
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 (std::set::const_iterator it = copiedVars.begin(); it != copiedVars.end(); ++it) {
copyConstructorShallowCopyError(*it, (*it)->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::style, "copyCtorPointerCopying",
"$symbol:" + varname + "\nValue of pointer '$symbol', which points to allocated memory, is copied in copy constructor instead of allocating new memory.", CWE398, false);
}
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::style, "noCopyConstructor", noMemberErrorMessage(scope, "copy constructor", isdefault), CWE398, inconclusive);
}
void CheckClass::noOperatorEqError(const Scope *scope, bool isdefault, const Token *alloc, bool inconclusive)
{
reportError(alloc, Severity::style, "noOperatorEq", noMemberErrorMessage(scope, "operator=", isdefault), CWE398, inconclusive);
}
void CheckClass::noDestructorError(const Scope *scope, bool isdefault, const Token *alloc)
{
reportError(alloc, Severity::style, "noDestructor", noMemberErrorMessage(scope, "destructor", isdefault), CWE398, false);
}
bool CheckClass::canNotCopy(const Scope *scope)
{
bool constructor = false;
bool publicAssign = false;
bool publicCopy = false;
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->isConstructor())
constructor = true;
if (func->access != Public)
continue;
if (func->type == Function::eCopyConstructor) {
publicCopy = true;
break;
} else 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 (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->isConstructor())
constructor = true;
if (func->access != Public)
continue;
if (func->type == Function::eCopyConstructor) {
publicCopy = true;
break;
} else if (func->type == Function::eMoveConstructor) {
publicMove = true;
break;
} else if (func->type == Function::eOperatorEqual) {
publicAssign = true;
break;
}
}
return constructor && !(publicAssign || publicCopy || publicMove);
}
void CheckClass::assignVar(unsigned int varid, const Scope *scope, std::vector &usage)
{
unsigned int count = 0;
for (std::list::const_iterator var = scope->varlist.begin(); var != scope->varlist.end(); ++var, ++count) {
if (var->declarationId() == varid) {
usage[count].assign = true;
return;
}
}
}
void CheckClass::initVar(unsigned int varid, const Scope *scope, std::vector &usage)
{
unsigned int count = 0;
for (std::list::const_iterator var = scope->varlist.begin(); var != scope->varlist.end(); ++var, ++count) {
if (var->declarationId() == varid) {
usage[count].init = true;
return;
}
}
}
void CheckClass::assignAllVar(std::vector &usage)
{
for (std::size_t i = 0; i < usage.size(); ++i)
usage[i].assign = true;
}
void CheckClass::clearAllVar(std::vector &usage)
{
for (std::size_t i = 0; i < usage.size(); ++i) {
usage[i].assign = false;
usage[i].init = false;
}
}
bool CheckClass::isBaseClassFunc(const Token *tok, const Scope *scope)
{
// Iterate through each base class...
for (std::size_t i = 0; i < scope->definedType->derivedFrom.size(); ++i) {
const Type *derivedFrom = scope->definedType->derivedFrom[i].type;
// Check if base class exists in database
if (derivedFrom && derivedFrom->classScope) {
const std::list& functionList = derivedFrom->classScope->functionList;
for (std::list::const_iterator func = functionList.begin(); func != functionList.end(); ++func) {
if (func->tokenDef->str() == tok->str())
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)
{
if (!func.functionScope)
throw InternalError(nullptr, "Internal Error: Invalid syntax"); // #5702
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(ftok->varId(), scope, usage);
} else { // c++11 delegate constructor
const Function *member = ftok->function();
// member function found
if (member) {
// recursive call
// assume that all variables are initialized
if (std::find(callstack.begin(), callstack.end(), member) != callstack.end()) {
/** @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(ftok->varId(), scope, usage);
// 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(ftok->next()->varId(), scope, usage);
}
// 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% (")) {
for (std::list::const_iterator var = scope->varlist.begin(); var != scope->varlist.end(); ++var) {
if (var->declarationId() == ftok->next()->varId()) {
/** @todo false negative: we assume function changes variable state */
assignVar(ftok->next()->varId(), scope, usage);
break;
}
}
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
else if (Token::Match(ftok, "::| memset ( &| this . %name%")) {
if (ftok->str() == "::")
ftok = ftok->next();
int offsetToMember = 4;
if (ftok->strAt(2) == "&")
++offsetToMember;
assignVar(ftok->tokAt(offsetToMember)->varId(), scope, usage);
ftok = ftok->linkAt(1);
continue;
}
// Clearing array..
else if (Token::Match(ftok, "::| memset ( %name% ,")) {
if (ftok->str() == "::")
ftok = ftok->next();
assignVar(ftok->tokAt(2)->varId(), scope, usage);
ftok = ftok->linkAt(1);
continue;
}
// Calling member function?
else if (Token::simpleMatch(ftok, "operator= (") &&
ftok->previous()->str() != "::") {
if (ftok->function() && ftok->function()->nestedIn == scope) {
const Function *member = ftok->function();
// recursive call
// assume that all variables are initialized
if (std::find(callstack.begin(), callstack.end(), member) != callstack.end()) {
/** @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);
}
}
// using default operator =, assume everything initialized
else {
assignAllVar(usage);
}
} else if (Token::Match(ftok, "::| %name% (") && ftok->str() != "if") {
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.begin(), callstack.end(), member) != callstack.end()) {
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();
assignVar(tok2->varId(), scope, usage);
}
}
}
// there is a called member function, but it has no implementation, so we assume it initializes everything
else {
assignAllVar(usage);
}
}
// not member function
else {
// could be a base class virtual function, so we assume it initializes everything
if (!func.isConstructor() && isBaseClassFunc(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(tok->varId(), scope, usage);
}
}
}
}
}
// Assignment of member variable?
else if (Token::Match(ftok, "%name% =")) {
assignVar(ftok->varId(), scope, usage);
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(tok2->varId(), scope, usage);
}
// 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(ftok->varId(), scope, usage);
}
// Assignment of array item of member variable?
else if (Token::Match(ftok, "* %name% =")) {
assignVar(ftok->next()->varId(), scope, usage);
} else if (Token::Match(ftok, "* this . %name% =")) {
assignVar(ftok->tokAt(3)->varId(), scope, usage);
}
// The functions 'clear' and 'Clear' are supposed to initialize variable.
if (Token::Match(ftok, "%name% . clear|Clear (")) {
assignVar(ftok->varId(), scope, usage);
}
}
}
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") + " '$symbol' does not have a constructor although it has private member variables.\n"
"The " + std::string(isStruct ? "struct" : "class") + " '$symbol' does not have 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, false);
}
void CheckClass::noExplicitConstructorError(const Token *tok, const std::string &classname, bool isStruct)
{
const std::string message(std::string(isStruct ? "Struct" : "Class") + " '$symbol' has a constructor with 1 argument that is not explicit.");
const std::string verbose(message + " Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.");
reportError(tok, Severity::style, "noExplicitConstructor", "$symbol:" + classname + '\n' + message + '\n' + verbose, CWE398, false);
}
void CheckClass::uninitVarError(const Token *tok, bool isprivate, const std::string &classname, const std::string &varname, bool inconclusive)
{
reportError(tok, Severity::warning, isprivate ? "uninitMemberVarPrivate" : "uninitMemberVar", "$symbol:" + classname + "::" + varname + "\nMember variable '$symbol' is not initialized in the constructor.", CWE398, 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);
}
//---------------------------------------------------------------------------
// ClassCheck: Use initialization list instead of assignment
//---------------------------------------------------------------------------
void CheckClass::initializationListUsage()
{
if (!mSettings->isEnabled(Settings::PERFORMANCE))
return;
for (const Scope *scope : mSymbolDatabase->functionScopes) {
// Check every constructor
if (!scope->function || (!scope->function->isConstructor()))
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) != "*") {
const Variable* var = tok->variable();
if (var && var->scope() == owner && !var->isStatic()) {
if (var->isPointer() || var->isReference() || var->isEnumType() || var->valueType()->type > ValueType::Type::ITERATOR)
continue;
bool allowed = true;
for (const Token* tok2 = tok->tokAt(2); tok2 && tok2->str() != ";"; tok2 = tok2->next()) {
const Variable* var2 = tok2->variable();
if (var2) {
if (var2->scope() == owner && tok2->strAt(-1)!=".") { // Is there a dependency between two member variables?
allowed = false;
break;
} else if (var2->isArray() && var2->isLocal()) { // Can't initialize with a local array
allowed = false;
break;
}
} else if (tok2->str() == "this") { // 'this' instance is not completely constructed in initialization list
allowed = false;
break;
} else if (Token::Match(tok2, "%name% (") && tok2->strAt(-1) != "." && isMemberFunc(owner, tok2)) { // Member function called?
allowed = false;
break;
}
}
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, false);
}
//---------------------------------------------------------------------------
// 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.begin(); func != scope->functionList.end(); ++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 != 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.end();
for (std::map::const_iterator iter = scope->definedTypesMap.begin(); iter != end; ++ iter) {
const Type *type = (*iter).second;
if (type->enclosingScope == scope && checkFunctionUsage(privfunc, type->classScope))
return true;
}
for (std::list::const_iterator i = scope->varlist.begin(); i != scope->varlist.end(); ++i) {
if (i->isStatic()) {
const Token* tok = Token::findmatch(scope->bodyEnd, "%varid% =|(|{", i->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->isEnabled(Settings::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 (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
// Get private functions..
if (func->type == Function::eFunction && func->access == 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
privateFuncs.erase(it++);
else
++it;
}
}
while (!privateFuncs.empty()) {
// Check that all private functions are used
bool used = checkFunctionUsage(privateFuncs.front(), scope); // Usage in this class
// Check in friend classes
const std::vector& friendList = scope->definedType->friendList;
for (size_t i = 0; i < friendList.size() && !used; i++) {
if (friendList[i].type)
used = checkFunctionUsage(privateFuncs.front(), friendList[i].type->classScope);
else
used = true; // Assume, it is used if we do not see friend class
}
if (!used)
unusedPrivateFunctionError(privateFuncs.front()->tokenDef, scope->className, privateFuncs.front()->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, false);
}
//---------------------------------------------------------------------------
// 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->isEnabled(Settings::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;
if (Token::Match(arg3, "sizeof ( %type% ) )"))
typeTok = arg3->tokAt(2);
else if (Token::Match(arg3, "sizeof ( %type% :: %type% ) )"))
typeTok = arg3->tokAt(4);
else if (Token::Match(arg3, "sizeof ( struct %type% ) )"))
typeTok = arg3->tokAt(3);
else if (Token::simpleMatch(arg3, "sizeof ( * this ) )") || Token::simpleMatch(arg1, "this ,")) {
type = findFunctionOf(arg3->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();
}
}
// 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% = calloc|malloc|realloc|g_malloc|g_try_malloc|g_realloc|g_try_realloc (")) {
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->isEnabled(Settings::PORTABILITY);
// recursively check all parent classes
for (std::size_t i = 0; i < type->definedType->derivedFrom.size(); i++) {
const Type* derivedFrom = type->definedType->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
std::list::const_iterator func;
for (func = type->functionList.begin(); func != type->functionList.end(); ++func) {
if (func->isVirtual()) {
if (allocation)
mallocOnClassError(tok, tok->str(), type->classDef, "virtual method");
else
memsetError(tok, tok->str(), "virtual method", type->classDef->str());
}
}
// Warn if type is a class or struct that contains any std::* variables
std::list::const_iterator var;
for (var = type->varlist.begin(); var != type->varlist.end(); ++var) {
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();
// check for std:: type
if (var->isStlType() && tok1->strAt(2) != "array" && !mSettings->library.podtype(tok1->strAt(2)))
if (allocation)
mallocOnClassError(tok, tok->str(), type->classDef, "'std::" + tok1->strAt(2) + "'");
else
memsetError(tok, tok->str(), "'std::" + tok1->strAt(2) + "'", 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 $symbol(), but class provides constructors. This is unsafe, "
"since no constructor is called and class members remain uninitialized. Consider using 'new' instead.", CWE762, false);
}
void CheckClass::mallocOnClassError(const Token* tok, const std::string &memfunc, const Token* classTok, const std::string &classname)
{
std::list toks = { tok, classTok };
reportError(toks, Severity::error, "mallocOnClassError",
"$symbol:" + memfunc +"\n"
"$symbol:" + classname +"\n"
"Memory for class instance allocated with " + memfunc + "(), but class contains a " + classname + ".\n"
"Memory for class instance allocated with " + memfunc + "(), but class a " + classname + ". This is unsafe, "
"since no constructor is called and class members remain uninitialized. Consider using 'new' instead.", CWE665, false);
}
void CheckClass::memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type)
{
reportError(tok, Severity::error, "memsetClass",
"$symbol:" + memfunc +"\n"
"$symbol:" + classname +"\n"
"Using '" + memfunc + "' on " + type + " that contains a " + classname + ".\n"
"Using '" + memfunc + "' on " + type + " that contains a " + classname + " is unsafe, because constructor, destructor "
"and copy operator calls are omitted. These are necessary for this non-POD type to ensure that a valid object "
"is created.", CWE762, false);
}
void CheckClass::memsetErrorReference(const Token *tok, const std::string &memfunc, const std::string &type)
{
reportError(tok, Severity::error, "memsetClassReference",
"$symbol:" + memfunc +"\n"
"Using '" + memfunc + "' on " + type + " that contains a reference.", CWE665, false);
}
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, false);
}
//---------------------------------------------------------------------------
// ClassCheck: "void operator=(" and "const type & operator=("
//---------------------------------------------------------------------------
void CheckClass::operatorEq()
{
if (!mSettings->isEnabled(Settings::STYLE))
return;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->type == Function::eOperatorEqual && func->access == Public) {
// skip "deleted" functions - cannot be called anyway
if (func->isDelete())
continue;
// use definition for check so we don't have to deal with qualification
bool returnSelfRef = false;
if (func->retDef->str() == scope->className) {
if (Token::Match(func->retDef, "%type% &")) {
returnSelfRef = true;
} else {
// We might have "Self&""
const Token * const tok = func->retDef->next();
if (tok && tok->str() == "<" && tok->link() && tok->link()->next() && tok->link()->next()->str() == "&")
returnSelfRef = true;
}
}
if (!returnSelfRef) {
// make sure we really have a copy assignment operator
const Token *paramTok = func->tokenDef->tokAt(2);
if (Token::Match(paramTok, "const| %name% &")) {
if (paramTok->str() == "const" &&
paramTok->strAt(1) == scope->className)
operatorEqReturnError(func->retDef, scope->className);
else if (paramTok->str() == scope->className)
operatorEqReturnError(func->retDef, scope->className);
}
}
}
}
}
}
void CheckClass::operatorEqReturnError(const Token *tok, const std::string &className)
{
reportError(tok, Severity::style, "operatorEq",
"$symbol:" + className +"\n"
"'$symbol::operator=' should return '$symbol &'.\n"
"The $symbol::operator= does not conform to standard C/C++ behaviour. To conform to standard C/C++ behaviour, return a reference to self (such as: '$symbol &$symbol::operator=(..) { .. return *this; }'. For safety reasons it might be better to not fix this message. If you think that safety is always more important than conformance then please ignore/suppress this message. For more details about this topic, see the book \"Effective C++\" by Scott Meyers."
, CWE398, false);
}
//---------------------------------------------------------------------------
// ClassCheck: "C& operator=(const C&) { ... return *this; }"
// operator= should return a reference to *this
//---------------------------------------------------------------------------
void CheckClass::operatorEqRetRefThis()
{
if (!mSettings->isEnabled(Settings::STYLE))
return;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->type == Function::eOperatorEqual && func->hasBody()) {
// make sure return signature is correct
if (Token::Match(func->retDef, "%type% &") && func->retDef->str() == scope->className) {
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 (tok->str() != "return")
continue;
foundReturn = true;
std::string cast("( " + scope->className + " & )");
if (Token::simpleMatch(tok->next(), cast.c_str()))
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.begin(); it != scope->functionList.end(); ++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::Match(tok->next(), "(| * this ;|=") ||
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) {
if (Token::simpleMatch(func->argDef, std::string("( const " + scope->className + " &").c_str())) {
// Typical wrong way to suppress default assignment operator by declaring it and leaving empty
operatorEqMissingReturnStatementError(func->token, func->access == 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 == Public);
}
void CheckClass::operatorEqRetRefThisError(const Token *tok)
{
reportError(tok, Severity::style, "operatorEqRetRefThis", "'operator=' should return reference to 'this' instance.", CWE398, false);
}
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, false);
}
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, false);
} 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->isEnabled(Settings::WARNING))
return;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
// skip classes with multiple inheritance
if (scope->definedType->derivedFrom.size() > 1)
continue;
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
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.begin()->nameToken();
if (!hasAssignSelf(&(*func), rhs)) {
if (hasAllocation(&(*func), scope))
operatorEqToSelfError(func->token);
}
}
}
}
}
}
bool CheckClass::hasAllocation(const Function *func, const Scope* scope) const
{
// This function is called when no simple check was found for assignment
// to self. We are currently looking for:
// - deallocate member ; ... member =
// - alloc member
// That is not ideal because it can cause false negatives but its currently
// necessary to prevent false positives.
const Token *last = func->functionScope->bodyEnd;
for (const Token *tok = func->functionScope->bodyStart; tok && (tok != last); tok = tok->next()) {
if (Token::Match(tok, "%var% = malloc|realloc|calloc|new") && isMemberVar(scope, tok))
return true;
// check for deallocating memory
const Token *var;
if (Token::Match(tok, "free ( %var%"))
var = tok->tokAt(2);
else if (Token::Match(tok, "delete [ ] %var%"))
var = tok->tokAt(3);
else if (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 != last); tok1 = tok1->next()) {
if (Token::Match(tok1, "%varid% =", var->varId()))
return true;
}
}
}
return false;
}
bool CheckClass::hasAssignSelf(const Function *func, const Token *rhs)
{
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;
std::stack tokens;
tokens.push(tok->next()->astOperand2());
while (!tokens.empty()) {
const Token *tok2 = tokens.top();
tokens.pop();
if (!tok2)
continue;
tokens.push(tok2->astOperand1());
tokens.push(tok2->astOperand2());
if (!Token::Match(tok2, "==|!="))
continue;
if (Token::simpleMatch(tok2->astOperand1(), "this"))
tok2 = tok2->astOperand2();
else if (Token::simpleMatch(tok2->astOperand2(), "this"))
tok2 = tok2->astOperand1();
else
continue;
if (tok2 && tok2->str() == "&" && !tok2->astOperand2() && tok2->astOperand1() && tok2->astOperand1()->str() == rhs->str())
return true;
}
}
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, false);
}
//---------------------------------------------------------------------------
// 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
// * base class is deleted
// unless inconclusive in which case:
// * base class has virtual members but doesn't have virtual destructor
const bool printInconclusive = mSettings->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->isVirtual()) {
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->isVirtual()) {
inconclusiveErrors.push_back(destructor);
break;
}
}
}
}
continue;
}
// 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 (std::size_t j = 0; j < scope->definedType->derivedFrom.size(); ++j) {
// Check if base class is public and exists in database
if (scope->definedType->derivedFrom[j].access != Private && scope->definedType->derivedFrom[j].type) {
const Type *derivedFrom = scope->definedType->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..
if (Token::simpleMatch(tok->tokAt(3), ("new " + derivedClass->str()).c_str())) {
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->isVirtual()) {
// 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 == 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 (std::list::const_iterator i = inconclusiveErrors.begin(); i != inconclusiveErrors.end(); ++i)
virtualDestructorError((*i)->tokenDef, (*i)->name(), emptyString, true);
}
void CheckClass::virtualDestructorError(const Token *tok, const std::string &Base, const std::string &Derived, bool inconclusive)
{
if (inconclusive) {
if (mSettings->isEnabled(Settings::WARNING))
reportError(tok, Severity::warning, "virtualDestructor", "$symbol:" + Base + "\nClass '$symbol' which has virtual members does not have a virtual destructor.", CWE404, true);
} else {
reportError(tok, Severity::error, "virtualDestructor",
"$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, false);
}
}
//---------------------------------------------------------------------------
// warn for "this-x". The indented code may be "this->x"
//---------------------------------------------------------------------------
void CheckClass::thisSubtraction()
{
if (!mSettings->isEnabled(Settings::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, false);
}
//---------------------------------------------------------------------------
// can member function be const?
//---------------------------------------------------------------------------
void CheckClass::checkConst()
{
// This is an inconclusive check. False positives: #3322.
if (!mSettings->inconclusive)
return;
if (!mSettings->isEnabled(Settings::STYLE))
return;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
// does the function have a body?
if (func->type != Function::eFunction || !func->hasBody())
continue;
// don't warn for friend/static/virtual methods
if (func->isFriend() || func->isStatic() || func->isVirtual())
continue;
// get last token of return type
const Token *previous = func->tokenDef->previous();
// does the function return a pointer or reference?
if (Token::Match(previous, "*|&")) {
if (func->retDef->str() != "const")
continue;
} else if (Token::Match(previous->previous(), "*|& >")) {
const Token *temp = previous->previous();
bool foundConst = false;
while (!Token::Match(temp->previous(), ";|}|{|public:|protected:|private:")) {
temp = temp->previous();
if (temp->str() == "const") {
foundConst = true;
break;
}
}
if (!foundConst)
continue;
} else if (func->isOperator() && Token::Match(previous, ";|{|}|public:|private:|protected:")) { // 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 {
// don't warn for unknown types..
// LPVOID, HDC, etc
if (previous->str().size() > 2 && !previous->type() && previous->isUpperCaseName())
continue;
}
// check if base class function is virtual
if (!scope->definedType->derivedFrom.empty() && func->isImplicitlyVirtual(true))
continue;
bool memberAccessed = false;
// if nothing non-const was found. write error..
if (!checkConstFunc(scope, &*func, memberAccessed))
continue;
if (func->isConst() && (memberAccessed || func->isOperator()))
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, !memberAccessed && !func->isOperator());
else // not inline
checkConstError2(func->token, func->tokenDef, classname, functionName, !memberAccessed && !func->isOperator());
}
}
}
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 true;
} else if (Token::simpleMatch(tok->tokAt(-3), "( * this )")) {
return 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);
for (std::list::const_iterator var = scope->varlist.begin(); var != scope->varlist.end(); ++var) {
if (var->name() == tok->str()) {
if (tok->varId() == 0)
mSymbolDatabase->debugMessage(tok, "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 (std::size_t i = 0; i < scope->definedType->derivedFrom.size(); ++i) {
// find the base class
const Type *derivedFrom = scope->definedType->derivedFrom[i].type;
// find the function in the base class
if (derivedFrom && derivedFrom->classScope) {
if (isMemberVar(derivedFrom->classScope, tok))
return true;
}
}
}
return false;
}
bool CheckClass::isMemberFunc(const Scope *scope, const Token *tok) const
{
if (!tok->function()) {
for (std::list::const_iterator i = scope->functionList.cbegin(); i != scope->functionList.cend(); ++i) {
if (i->name() == tok->str()) {
const Token* tok2 = tok->tokAt(2);
size_t argsPassed = tok2->str() == ")" ? 0 : 1;
for (;;) {
tok2 = tok2->nextArgument();
if (tok2)
argsPassed++;
else
break;
}
if (argsPassed == i->argCount() || (argsPassed < i->argCount() && argsPassed >= i->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 (std::size_t i = 0; i < scope->definedType->derivedFrom.size(); ++i) {
// find the base class
const Type *derivedFrom = scope->definedType->derivedFrom[i].type;
// find the function in the base class
if (derivedFrom && derivedFrom->classScope) {
if (isMemberFunc(derivedFrom->classScope, tok))
return true;
}
}
}
return false;
}
bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok) const
{
if (!tok->function())
return false;
else if (tok->function()->nestedIn == scope)
return tok->function()->isConst();
// not found in this class
if (!scope->definedType->derivedFrom.empty()) {
// check each base class
for (std::size_t i = 0; i < scope->definedType->derivedFrom.size(); ++i) {
// find the base class
const Type *derivedFrom = scope->definedType->derivedFrom[i].type;
// find the function in the base class
if (derivedFrom && derivedFrom->classScope) {
if (isConstMemberFunc(derivedFrom->classScope, tok))
return true;
}
}
}
return false;
}
namespace {
// The container contains the STL types whose operator[] is not a const.
const std::set stl_containers_not_const = { "map", "unordered_map" };
}
bool CheckClass::checkConstFunc(const Scope *scope, const Function *func, bool& memberAccessed) const
{
// 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 = true;
const Variable* v = tok1->variable();
if (v && v->isMutable())
continue;
if (tok1->str() == "this" && tok1->previous()->isAssignmentOp())
return false;
const Token* lhs = tok1->previous();
if (lhs->str() == "&") {
lhs = lhs->previous();
if (lhs->tokType() == Token::eAssignmentOp && lhs->previous()->variable()) {
if (lhs->previous()->variable()->typeStartToken()->strAt(-1) != "const" && lhs->previous()->variable()->isPointer())
return false;
}
} else if (lhs->str() == ":" && lhs->astParent() && lhs->astParent()->str() == "(" && tok1->strAt(1) == ")") { // 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->tokType() == Token::eAssignmentOp) {
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;
}
if (!jumpBackToken)
jumpBackToken = end->next(); // Check inside the [] brackets
end = end->linkAt(1);
} else if (end->strAt(1) == ")")
end = end->next();
else
break;
}
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")))
;
else if (!var->typeScope() || !isConstMemberFunc(var->typeScope(), end))
return false;
}
// Assignment
else if (end->next()->tokType() == Token::eAssignmentOp)
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
}
// 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;
}
// function call..
else if (Token::Match(tok1, "%name% (") && !tok1->isStandardType() &&
!Token::Match(tok1, "return|if|string|switch|while|catch|for")) {
if (isMemberFunc(scope, tok1) && tok1->strAt(-1) != ".") {
if (!isConstMemberFunc(scope, tok1))
return false;
memberAccessed = true;
}
// Member variable given as parameter
const Token *lpar = tok1->next();
if (Token::simpleMatch(lpar, "( ) ("))
lpar = lpar->tokAt(2);
for (const Token* tok2 = lpar->next(); tok2 && tok2 != tok1->next()->link(); tok2 = tok2->next()) {
if (tok2->str() == "(")
tok2 = tok2->link();
else if (tok2->isName() && isMemberVar(scope, tok2)) {
const Variable* var = tok2->variable();
if (!var || !var->isMutable())
return false; // TODO: Only bailout if function takes argument as non-const reference
}
}
} 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, true);
else
reportError(toks, Severity::performance, "functionStatic",
"$symbol:" + classname + "::" + funcname +"\n"
"Technically the member function '$symbol' can be static.\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?", CWE398, true);
}
//---------------------------------------------------------------------------
// 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->isEnabled(Settings::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->inconclusive)
return;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
// iterate through all member functions looking for constructors
for (std::list::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++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 (std::size_t 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, true);
}
//---------------------------------------------------------------------------
// 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% (|{ %var% )|}") && tok->next()->varId() == tok->tokAt(3)->varId()) {
selfInitializationError(tok, tok->strAt(1));
}
}
}
}
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, false);
}
//---------------------------------------------------------------------------
// Check for virtual function calls in constructor/destructor
//---------------------------------------------------------------------------
void CheckClass::checkVirtualFunctionCallInConstructor()
{
if (! mSettings->isEnabled(Settings::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 (std::list::const_iterator it = virtualFunctionCalls.begin(); it != virtualFunctionCalls.end(); ++it) {
const Token * callToken = *it;
std::list callstack(1, callToken);
getFirstVirtualFunctionCallStack(virtualFunctionCallsMap, callToken, callstack);
if (callstack.empty())
continue;
if (callstack.back()->function()->isPure())
pureVirtualFunctionCallInConstructorError(scope->function, callstack, callstack.back()->str());
else
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())
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 ||
(tok->previous() && tok->previous()->str() == "."))
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->isVirtual()) {
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->isVirtual() && (!callFunction->isPure() || !callFunction->hasBody())) {
pureFuncStack.push_back(callFunction->tokenDef);
return;
}
std::map >::const_iterator found = virtualFunctionCallsMap.find(callFunction);
if (found == virtualFunctionCallsMap.end() || found->second.empty()) {
pureFuncStack.clear();
return;
}
const Token * firstCall = *found->second.begin();
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;
int lineNumber = 1;
for (std::list::const_iterator it = tokStack.begin(); it != tokStack.end(); ++it)
errorPath.emplace_back(*it, "Calling " + (*it)->str());
if (!errorPath.empty()) {
lineNumber = errorPath.front().first->linenr();
errorPath.back().second = funcname + " is a virtual method";
}
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::warning, "virtualCallInConstructor",
"Virtual function '" + funcname + "' is called from " + scopeFunctionTypeName + " '" + constructorName + "' at line " + MathLib::toString(lineNumber) + ".\n"
"Call of pure virtual function '" + funcname + "' in " + scopeFunctionTypeName + ". Dynamic binding is not used.", CWE(0U), false);
}
void CheckClass::pureVirtualFunctionCallInConstructorError(
const Function * scopeFunction,
const std::list & tokStack,
const std::string &purefuncname)
{
const char * scopeFunctionTypeName = scopeFunction ? getFunctionTypeName(scopeFunction->type) : "constructor";
ErrorPath errorPath;
for (std::list::const_iterator it = tokStack.begin(); it != tokStack.end(); ++it)
errorPath.emplace_back(*it, "Calling " + (*it)->str());
if (!errorPath.empty())
errorPath.back().second = purefuncname + " is a pure virtual method without body";
reportError(tokStack, Severity::warning, "pureVirtualCall",
"$symbol:" + purefuncname +"\n"
"Call of pure virtual function '$symbol' in " + scopeFunctionTypeName + ".\n"
"Call of pure virtual function '$symbol' in " + scopeFunctionTypeName + ". The call will fail during runtime.", CWE(0U), false);
}
//---------------------------------------------------------------------------
// Check for members hiding inherited members with the same name
//---------------------------------------------------------------------------
void CheckClass::checkDuplInheritedMembers()
{
if (!mSettings->isEnabled(Settings::WARNING))
return;
// Iterate over all classes
for (std::list::const_iterator classIt = mSymbolDatabase->typeList.begin();
classIt != mSymbolDatabase->typeList.end();
++classIt) {
// Iterate over the parent classes
for (std::vector::const_iterator parentClassIt = classIt->derivedFrom.begin();
parentClassIt != classIt->derivedFrom.end();
++parentClassIt) {
// Check if there is info about the 'Base' class
if (!parentClassIt->type || !parentClassIt->type->classScope)
continue;
// Check if they have a member variable in common
for (std::list::const_iterator classVarIt = classIt->classScope->varlist.begin();
classVarIt != classIt->classScope->varlist.end();
++classVarIt) {
for (std::list::const_iterator parentClassVarIt = parentClassIt->type->classScope->varlist.begin();
parentClassVarIt != parentClassIt->type->classScope->varlist.end();
++parentClassVarIt) {
if (classVarIt->name() == parentClassVarIt->name() && !parentClassVarIt->isPrivate()) { // Check if the class and its parent have a common variable
duplInheritedMembersError(classVarIt->nameToken(), parentClassVarIt->nameToken(),
classIt->name(), parentClassIt->type->name(), classVarIt->name(),
classIt->classScope->type == Scope::eStruct,
parentClassIt->type->classScope->type == Scope::eStruct);
}
}
}
}
}
}
void CheckClass::duplInheritedMembersError(const Token *tok1, const Token* tok2,
const std::string &derivedname, const std::string &basename,
const std::string &variablename, bool derivedIsStruct, bool baseIsStruct)
{
std::list toks = { tok1, tok2 };
const std::string symbols = "$symbol:" + derivedname + "\n$symbol:" + variablename + "\n$symbol:" + basename;
const std::string message = "The " + std::string(derivedIsStruct ? "struct" : "class") + " '" + derivedname +
"' defines member variable with name '" + variablename + "' also defined in its parent " +
std::string(baseIsStruct ? "struct" : "class") + " '" + basename + "'.";
reportError(toks, Severity::warning, "duplInheritedMember", symbols + '\n' + message, CWE398, false);
}
//---------------------------------------------------------------------------
// Check that copy constructor and operator defined together
//---------------------------------------------------------------------------
enum CtorType {
NO,
WITHOUT_BODY,
WITH_BODY
};
void CheckClass::checkCopyCtorAndEqOperator()
{
if (!mSettings->isEnabled(Settings::WARNING))
return;
for (const Scope * scope : mSymbolDatabase->classAndStructScopes) {
bool hasNonStaticVars = false;
for (std::list::const_iterator var = scope->varlist.begin(); var != scope->varlist.end(); ++var) {
if (!var->isStatic()) {
hasNonStaticVars = true;
break;
}
}
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::checkUnsafeClassDivZero(bool test)
{
// style severity: it is a style decision if classes should be safe or
// if users should be required to be careful. I expect that many users
// will disagree about these reports.
if (!mSettings->isEnabled(Settings::STYLE))
return;
for (const Scope * classScope : mSymbolDatabase->classAndStructScopes) {
if (!test && classScope->classDef->fileIndex() != 1)
continue;
for (const Function &func : classScope->functionList) {
if (func.access != AccessControl::Public)
continue;
if (!func.hasBody())
continue;
if (func.name().compare(0,8,"operator")==0)
continue;
for (const Token *tok = func.functionScope->bodyStart; tok; tok = tok->next()) {
if (Token::Match(tok, "if|switch|while|for|do|}"))
break;
if (tok->str() != "/")
continue;
if (!tok->valueType() || !tok->valueType()->isIntegral())
continue;
if (!tok->astOperand2())
continue;
const Variable *var = tok->astOperand2()->variable();
if (!var || !var->isArgument())
continue;
unsafeClassDivZeroError(tok, classScope->className, func.name(), var->name());
break;
}
}
}
}
void CheckClass::unsafeClassDivZeroError(const Token *tok, const std::string &className, const std::string &methodName, const std::string &varName)
{
const std::string symbols = "$symbol:" + className + "\n$symbol:" + methodName + "\n$symbol:" + varName + '\n';
const std::string s = className + "::" + methodName + "()";
reportError(tok, Severity::style, "unsafeClassDivZero", symbols + "Public interface of " + className + " is not safe. When calling " + s + ", if parameter " + varName + " is 0 that leads to division by zero.");
}
void CheckClass::checkOverride()
{
if (!mSettings->isEnabled(Settings::STYLE))
return;
if (mSettings->standards.cpp < Standards::CPP11)
return;
for (const Scope * classScope : mSymbolDatabase->classAndStructScopes) {
if (!classScope->definedType || classScope->definedType->derivedFrom.empty())
continue;
for (const Function &func : classScope->functionList) {
if (func.hasOverrideSpecifier() || func.hasFinalSpecifier())
continue;
const Function *baseFunc = func.getOverridenFunction();
if (baseFunc)
overrideError(baseFunc, &func);
}
}
}
void CheckClass::overrideError(const Function *funcInBase, const Function *funcInDerived)
{
const std::string functionName = funcInDerived ? funcInDerived->name() : "";
ErrorPath errorPath;
if (funcInBase && funcInDerived) {
errorPath.push_back(ErrorPathItem(funcInBase->tokenDef, "Virtual function in base class"));
errorPath.push_back(ErrorPathItem(funcInDerived->tokenDef, "Function in derived class"));
}
reportError(errorPath, Severity::style, "missingOverride",
"$symbol:" + functionName + "\n"
"The function '$symbol' overrides a function in a base class but is not marked with a 'override' specifier.",
CWE(0U) /* Unknown CWE! */,
false);
}