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cppcheck/lib/checkclass.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2014 Daniel Marjamäki and 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 <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
#include "checkclass.h"
#include "tokenize.h"
#include "token.h"
#include "errorlogger.h"
#include "symboldatabase.h"
#include <string>
#include <algorithm>
#include <cctype>
//---------------------------------------------------------------------------
// Register CheckClass..
namespace {
CheckClass instance;
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 "";
}
inline bool isPureWithoutBody(Function const & func)
{
return func.isPure && !func.hasBody;
}
}
//---------------------------------------------------------------------------
CheckClass::CheckClass(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
: Check(myName(), tokenizer, settings, errorLogger),
symbolDatabase(tokenizer?tokenizer->getSymbolDatabase():nullptr)
{
}
//---------------------------------------------------------------------------
// ClassCheck: Check that all class constructors are ok.
//---------------------------------------------------------------------------
void CheckClass::constructors()
{
bool style = _settings->isEnabled("style");
bool warnings = _settings->isEnabled("warning");
if (!style && !warnings)
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
// There are no constructors.
if (scope->numConstructors == 0 && style) {
// If there is a private variable, there should be a constructor..
std::list<Variable>::const_iterator var;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var) {
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 (!warnings)
continue;
// #3196 => bailout if there are nested unions
// TODO: handle union variables better
{
bool bailout = false;
for (std::list<Scope *>::const_iterator it = scope->nestedList.begin(); it != scope->nestedList.end(); ++it) {
const Scope * const nestedScope = *it;
if (nestedScope->type == Scope::eUnion) {
bailout = true;
break;
}
}
if (bailout)
continue;
}
std::list<Function>::const_iterator func;
std::vector<Usage> usage(scope->varlist.size());
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (!func->hasBody || !(func->isConstructor() ||
func->type == Function::eOperatorEqual))
continue;
// Mark all variables not used
clearAllVar(usage);
std::list<const Function *> callstack;
initializeVarList(*func, callstack, &(*scope), usage);
// Check if any variables are uninitialized
std::list<Variable>::const_iterator var;
unsigned int count = 0;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var, ++count) {
// check for C++11 initializer
if (var->hasDefault())
usage[count].init = true;
bool inconclusive = false;
if (usage[count].assign || usage[count].init || var->isStatic())
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->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->typeScope()) {
if (func->type == Function::eMoveConstructor) {
if (canNotMove(var->typeScope()))
continue;
} else {
if (canNotCopy(var->typeScope()))
continue;
}
}
// Don't warn about unknown types in copy constructors since we
// don't know if they can be copied or not..
if (!var->isPointer() &&
!(var->type() && var->type()->needInitialization != Type::True) &&
(func->type == Function::eCopyConstructor || func->type == Function::eOperatorEqual)) {
bool stdtype = false;
for (const Token *type = var->typeStartToken(); type && type->isName(); type = type->next())
stdtype |= type->isStandardType();
if (!stdtype) {
if (_settings->inconclusive)
inconclusive = true;
else
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) {
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->classStart &&
func->functionScope->classStart->link() == func->functionScope->classStart->next()) {
// don't warn about user defined default constructor when there are other constructors
if (_settings->inconclusive)
uninitVarError(func->token, scope->className, var->name(), true);
} else
uninitVarError(func->token, scope->className, var->name(), inconclusive);
}
}
}
}
}
}
void CheckClass::copyconstructors()
{
if (!_settings->isEnabled("style"))
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
std::map<unsigned int, const Token*> allocatedVars;
for (std::list<Function>::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->type == Function::eConstructor && func->functionScope) {
const Token* tok = func->functionScope->classDef->linkAt(1);
for (const Token* const end = func->functionScope->classStart; tok != end; tok = tok->next()) {
if (Token::Match(tok, "%var% ( new|malloc|g_malloc|g_try_malloc|realloc|g_realloc|g_try_realloc")) {
const Variable* var = tok->variable();
if (var && var->isPointer() && var->scope() == &*scope)
allocatedVars[tok->varId()] = tok;
}
}
for (const Token* const end = func->functionScope->classEnd; tok != end; tok = tok->next()) {
if (Token::Match(tok, "%var% = new|malloc|g_malloc|g_try_malloc|realloc|g_realloc|g_try_realloc")) {
const Variable* var = tok->variable();
if (var && var->isPointer() && var->scope() == &*scope)
allocatedVars[tok->varId()] = tok;
}
}
}
}
std::set<const Token*> copiedVars;
const Token* copyCtor = 0;
for (std::list<Function>::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->type == Function::eCopyConstructor) {
copyCtor = func->tokenDef;
if (func->functionScope) {
const Token* tok = func->tokenDef->linkAt(1)->next();
if (tok->str()==":") {
tok=tok->next();
while (Token::Match(tok, "%var% (")) {
if (allocatedVars.find(tok->varId()) != allocatedVars.end()) {
if (tok->varId() && Token::Match(tok->tokAt(2), "%var% . %var% )"))
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->classStart; tok!=func->functionScope->classEnd; 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% = %var% . %var% ;") && allocatedVars.find(tok->varId()) != allocatedVars.end()) {
copiedVars.insert(tok);
}
}
} else // non-copyable or implementation not seen
allocatedVars.clear();
break;
}
}
if (!copyCtor) {
if (!allocatedVars.empty() && scope->definedType->derivedFrom.empty()) // TODO: Check if base class is non-copyable
noCopyConstructorError(scope->classDef, scope->className, scope->type == Scope::eStruct);
} else {
if (!copiedVars.empty()) {
for (std::set<const Token*>::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<unsigned int, const Token*>::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<const Token*> 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", "Value of pointer '" + varname + "', which points to allocated memory, is copied in copy constructor instead of allocating new memory.");
}
void CheckClass::noCopyConstructorError(const Token *tok, const std::string &classname, bool isStruct)
{
// The constructor might be intentionally missing. Therefore this is not a "warning"
reportError(tok, Severity::style, "noCopyConstructor",
"'" + std::string(isStruct ? "struct" : "class") + " " + classname +
"' does not have a copy constructor which is recommended since the class contains a pointer to allocated memory.");
}
bool CheckClass::canNotCopy(const Scope *scope)
{
std::list<Function>::const_iterator func;
bool constructor = false;
bool publicAssign = false;
bool publicCopy = false;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->isConstructor())
constructor = true;
if ((func->type == Function::eCopyConstructor) &&
func->access == Public)
publicCopy = true;
else if (func->type == Function::eOperatorEqual && func->access == Public)
publicAssign = true;
}
return constructor && !(publicAssign || publicCopy);
}
bool CheckClass::canNotMove(const Scope *scope)
{
std::list<Function>::const_iterator func;
bool constructor = false;
bool publicAssign = false;
bool publicCopy = false;
bool publicMove = false;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->isConstructor())
constructor = true;
if ((func->type == Function::eCopyConstructor) &&
func->access == Public)
publicCopy = true;
else if ((func->type == Function::eMoveConstructor) &&
func->access == Public)
publicMove = true;
else if (func->type == Function::eOperatorEqual && func->access == Public)
publicAssign = true;
}
return constructor && !(publicAssign || publicCopy || publicMove);
}
void CheckClass::assignVar(const std::string &varname, const Scope *scope, std::vector<Usage> &usage)
{
std::list<Variable>::const_iterator var;
unsigned int count = 0;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var, ++count) {
if (var->name() == varname) {
usage[count].assign = true;
return;
}
}
}
void CheckClass::initVar(const std::string &varname, const Scope *scope, std::vector<Usage> &usage)
{
std::list<Variable>::const_iterator var;
unsigned int count = 0;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var, ++count) {
if (var->name() == varname) {
usage[count].init = true;
return;
}
}
}
void CheckClass::assignAllVar(std::vector<Usage> &usage)
{
for (std::size_t i = 0; i < usage.size(); ++i)
usage[i].assign = true;
}
void CheckClass::clearAllVar(std::vector<Usage> &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) {
std::list<Function>::const_iterator func;
for (func = derivedFrom->classScope->functionList.begin(); func != derivedFrom->classScope->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<const Function *> &callstack, const Scope *scope, std::vector<Usage> &usage)
{
if (!func.functionScope)
throw InternalError(0, "Internal Error: Invalid syntax"); // #5702
bool initList = func.isConstructor();
const Token *ftok = func.arg->link()->next();
int level = 0;
for (; ftok && ftok != func.functionScope->classEnd; ftok = ftok->next()) {
// Class constructor.. initializing variables like this
// clKalle::clKalle() : var(value) { }
if (initList) {
if (level == 0 && Token::Match(ftok, "%var% (")) {
if (ftok->str() != func.name()) {
initVar(ftok->str(), scope, usage);
} else { // c++11 delegate constructor
const Function *member = scope->findFunction(ftok);
// 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, "%var% {") && ftok->str() != "const" && Token::Match(ftok->next()->link()->next(), "%type%|,|{")) {
if (ftok->str() != func.name()) {
initVar(ftok->str(), scope, usage);
} else { // c++11 delegate constructor
const Function *member = scope->findFunction(ftok);
// 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);
}
}
}
ftok = ftok->linkAt(1);
} else if (level != 0 && Token::Match(ftok, "%var% =")) // assignment in the initializer: var(value = x)
assignVar(ftok->str(), scope, usage);
else if (ftok->str() == "(")
level++;
else if (ftok->str() == ")")
level--;
else if (ftok->str() == "{") {
if (level == 0)
initList = false;
else
ftok = ftok->link();
}
}
if (initList)
continue;
// Variable getting value from stream?
if (Token::Match(ftok, ">> %var%")) {
assignVar(ftok->strAt(1), scope, usage);
}
// Before a new statement there is "[{};()=[]"
if (! Token::Match(ftok, "[{};()=[]"))
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, "[;{}] %var% (") && Token::Match(ftok->linkAt(2), ") . %var% ( *| this ) ;")) {
assignAllVar(usage);
break;
}
// Calling member variable function?
if (Token::Match(ftok->next(), "%var% . %var% (")) {
std::list<Variable>::const_iterator var;
for (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()->str(), scope, usage);
break;
}
}
ftok = ftok->tokAt(2);
}
if (!Token::Match(ftok->next(), "::| %var%") &&
!Token::Match(ftok->next(), "this . %var%") &&
!Token::Match(ftok->next(), "* %var% =") &&
!Token::Match(ftok->next(), "( * this ) . %var%"))
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, ":: %var%"))
ftok = ftok->next();
while (Token::Match(ftok, "%var% ::"))
ftok = ftok->tokAt(2);
// Clearing all variables..
if (Token::Match(ftok, "::| memset ( this ,")) {
assignAllVar(usage);
return;
}
// Clearing array..
else if (Token::Match(ftok, "::| memset ( %var% ,")) {
if (ftok->str() == "::")
ftok = ftok->next();
assignVar(ftok->strAt(2), 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, "::| %var% (") && 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, "[(,] &| %var% [,)]")) {
tok2 = tok2->next();
if (tok2->str() == "&")
tok2 = tok2->next();
assignVar(tok2->str(), 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->str(), scope, usage);
}
}
}
}
}
// Assignment of member variable?
else if (Token::Match(ftok, "%var% =")) {
assignVar(ftok->str(), scope, usage);
}
// Assignment of array item of member variable?
else if (Token::Match(ftok, "%var% [|.")) {
const Token *tok2 = ftok;
while (tok2) {
if (tok2->strAt(1) == "[")
tok2 = tok2->next()->link();
else if (Token::Match(tok2->next(), ". %var%"))
tok2 = tok2->tokAt(2);
else
break;
}
if (tok2 && tok2->strAt(1) == "=")
assignVar(ftok->str(), scope, usage);
}
// Assignment of array item of member variable?
else if (Token::Match(ftok, "* %var% =")) {
assignVar(ftok->next()->str(), scope, usage);
}
// The functions 'clear' and 'Clear' are supposed to initialize variable.
if (Token::Match(ftok, "%var% . clear|Clear (")) {
assignVar(ftok->str(), 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",
"The " + std::string(isStruct ? "struct" : "class") + " '" + classname +
"' does not have a constructor.\n"
"The " + std::string(isStruct ? "struct" : "class") + " '" + classname +
"' 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.");
}
void CheckClass::uninitVarError(const Token *tok, const std::string &classname, const std::string &varname, bool inconclusive)
{
reportError(tok, Severity::warning, "uninitMemberVar", "Member variable '" + classname + "::" + varname + "' is not initialized in the constructor.", inconclusive);
}
void CheckClass::operatorEqVarError(const Token *tok, const std::string &classname, const std::string &varname, bool inconclusive)
{
reportError(tok, Severity::warning, "operatorEqVarError", "Member variable '" + classname + "::" + varname + "' is not assigned a value in '" + classname + "::operator='.", inconclusive);
}
//---------------------------------------------------------------------------
// ClassCheck: Use initialization list instead of assignment
//---------------------------------------------------------------------------
void CheckClass::initializationListUsage()
{
if (!_settings->isEnabled("performance"))
return;
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
// Check every constructor
if (!scope->function || (!scope->function->isConstructor()))
continue;
const Scope* owner = scope->functionOf;
for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "%var% (")) // 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 (tok->varId() && Token::Match(tok, "%var% = %any%")) {
const Variable* var = tok->variable();
if (var && var->scope() == owner && !var->isStatic()) {
bool allowed = true;
for (const Token* tok2 = tok->tokAt(2); tok2->str() != ";"; tok2 = tok2->next()) {
if (tok2->varId()) {
const Variable* var2 = tok2->variable();
if (var2 && var2->scope() == owner &&
tok2->strAt(-1)!=".") { // Is there a dependency between two member variables?
allowed = false;
break;
} else if (var2 && (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, "%var% (") && tok2->strAt(-1) != "." && isMemberFunc(owner, tok2)) { // Member function called?
allowed = false;
break;
}
}
if (!allowed)
continue;
if (!var->isPointer() && !var->isReference() && (var->type() || Token::Match(var->typeStartToken(), "std :: string|wstring !!::") || (Token::Match(var->typeStartToken(), "std :: %type% <") && !Token::simpleMatch(var->typeStartToken()->linkAt(3), "> ::"))))
suggestInitializationList(tok, tok->str());
}
}
}
}
}
void CheckClass::suggestInitializationList(const Token* tok, const std::string& varname)
{
reportError(tok, Severity::performance, "useInitializationList", "Variable '" + varname + "' 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 '" + varname + "' a value by passing the value to the constructor in the initialization list.");
}
//---------------------------------------------------------------------------
// ClassCheck: Unused private functions
//---------------------------------------------------------------------------
static bool checkFunctionUsage(const std::string& name, const Scope* scope)
{
if (!scope)
return true; // Assume it is used, if scope is not seen
for (std::list<Function>::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->functionScope) {
if (Token::Match(func->tokenDef, "%var% (")) {
for (const Token *ftok = func->tokenDef->tokAt(2); ftok && ftok->str() != ")"; ftok = ftok->next()) {
if (Token::Match(ftok, "= %var% [(,)]") && ftok->strAt(1) == name)
return true;
if (ftok->str() == "(")
ftok = ftok->link();
}
}
for (const Token *ftok = func->functionScope->classDef->linkAt(1); ftok != func->functionScope->classEnd; ftok = ftok->next()) {
if (ftok->str() == name) // Function used. TODO: Handle overloads
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;
}
for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
if ((*i)->isClassOrStruct())
if (checkFunctionUsage(name, *i)) // Check nested classes, which can access private functions of their base
return true;
}
return false; // Unused in this scope
}
void CheckClass::privateFunctions()
{
if (!_settings->isEnabled("style"))
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
// do not check borland classes with properties..
if (Token::findsimplematch(scope->classStart, "; __property ;", scope->classEnd))
continue;
std::list<const Function*> FuncList;
for (std::list<Function>::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
FuncList.push_back(&*func);
}
// Bailout for overridden virtual functions of base classes
if (!scope->definedType->derivedFrom.empty()) {
// Check virtual functions
for (std::list<const Function*>::iterator it = FuncList.begin(); it != FuncList.end();) {
if ((*it)->isImplicitlyVirtual(true)) // Give true as default value to be returned if we don't see all base classes
FuncList.erase(it++);
else
++it;
}
}
while (!FuncList.empty()) {
const std::string& funcName = FuncList.front()->tokenDef->str();
// Check that all private functions are used
bool used = checkFunctionUsage(funcName, &*scope); // Usage in this class
// Check in friend classes
for (std::list<Type::FriendInfo>::const_iterator it = scope->definedType->friendList.begin(); !used && it != scope->definedType->friendList.end(); ++it) {
if (it->type)
used = checkFunctionUsage(funcName, it->type->classScope);
else
used = true; // Assume, it is used if we do not see friend class
}
if (!used)
unusedPrivateFunctionError(FuncList.front()->tokenDef, scope->className, funcName);
FuncList.pop_front();
}
}
}
void CheckClass::unusedPrivateFunctionError(const Token *tok, const std::string &classname, const std::string &funcname)
{
reportError(tok, Severity::style, "unusedPrivateFunction", "Unused private function: '" + classname + "::" + funcname + "'");
}
//---------------------------------------------------------------------------
// 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 0;
}
void CheckClass::checkMemset()
{
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "memset|memcpy|memmove ( %any%")) {
const Token* arg1 = tok->tokAt(2);
const Token* arg3 = arg1;
arg3 = arg3->nextArgument();
arg3 = (arg3 != nullptr) ? arg3->nextArgument() : nullptr;
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 derefs = 1;
for (;; arg1 = arg1->next()) {
if (arg1->str() == "&")
derefs--;
else if (arg1->str() == "*")
derefs++;
else
break;
}
const Variable *var = arg1->variable();
if (var && arg1->strAt(1) == ",") {
if (var->isPointer()) {
derefs--;
if (var->typeEndToken() && Token::simpleMatch(var->typeEndToken()->previous(), "* *")) // Check if it's a pointer to pointer
derefs--;
}
if (var->isArray())
derefs -= (int)var->dimensions().size();
if (derefs == 0)
type = var->typeScope();
// TODO: The SymbolDatabase mix up variables in nested structs.
// So we must bailout right now if there are nested structs.
bool bailout = false;
for (const Token *typetok2 = var->typeStartToken(); typetok2 && typetok2 != var->typeEndToken(); typetok2 = typetok2->next()) {
if (typetok2->str() == "::")
bailout = true;
if (typetok2->str() == "{") {
bailout = false;
break;
}
}
if (bailout)
continue;
}
}
// No type defined => The tokens didn't match
if (!typeTok && !type)
continue;
if (typeTok && typeTok->str() == "(")
typeTok = typeTok->next();
if (!type) {
const Type* t = symbolDatabase->findVariableType(&(*scope), typeTok);
if (t)
type = t->classScope;
}
if (type) {
std::list<const Scope *> 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 (")) {
std::list<const Scope *> parsedTypes;
checkMemsetType(&(*scope), tok->tokAt(2), tok->variable()->typeScope(), true, parsedTypes);
if (tok->variable()->typeScope()->numConstructors > 0 && _settings->isEnabled("warning"))
mallocOnClassWarning(tok, tok->strAt(2), tok->variable()->typeScope()->classDef);
}
}
}
}
void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Scope *type, bool allocation, std::list<const Scope *> parsedTypes)
{
// If type has been checked there is no need to check it again
if (std::find(parsedTypes.begin(), parsedTypes.end(), type) != parsedTypes.end())
return;
parsedTypes.push_back(type);
// recursively check all parent classes
for (std::size_t i = 0; i < type->definedType->derivedFrom.size(); i++) {
if (type->definedType->derivedFrom[i].type && type->definedType->derivedFrom[i].type->classScope)
checkMemsetType(start, tok, type->definedType->derivedFrom[i].type->classScope, allocation, parsedTypes);
}
// Warn if type is a class that contains any virtual functions
std::list<Function>::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<Variable>::const_iterator var;
for (var = type->varlist.begin(); var != type->varlist.end(); ++var) {
if (var->isReference()) {
memsetErrorReference(tok, tok->str(), type->classDef->str());
continue;
}
// don't warn if variable static or const, pointer or reference
if (!var->isStatic() && !var->isConst() && !var->isPointer()) {
const Token *tok1 = var->typeStartToken();
const Scope *typeScope = var->typeScope();
// check for std:: type
if (var->isStlType() && tok1->strAt(2) != "array")
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);
}
}
}
void CheckClass::mallocOnClassWarning(const Token* tok, const std::string &memfunc, const Token* classTok)
{
std::list<const Token *> toks;
toks.push_back(tok);
toks.push_back(classTok);
reportError(toks, Severity::warning, "mallocOnClassWarning",
"Memory for class instance allocated with " + memfunc + "(), but class provides constructors.\n"
"Memory for class instance allocated with " + memfunc + "(), but class provides constructors. This is unsafe, "
"since no constructor is called and class members remain uninitialized. Consider using 'new' instead.");
}
void CheckClass::mallocOnClassError(const Token* tok, const std::string &memfunc, const Token* classTok, const std::string &classname)
{
std::list<const Token *> toks;
toks.push_back(tok);
toks.push_back(classTok);
reportError(toks, Severity::error, "mallocOnClassError",
"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.");
}
void CheckClass::memsetError(const Token *tok, const std::string &memfunc, const std::string &classname, const std::string &type)
{
reportError(tok, Severity::error, "memsetClass",
"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.");
}
void CheckClass::memsetErrorReference(const Token *tok, const std::string &memfunc, const std::string &type)
{
reportError(tok, Severity::error, "memsetClass", "Using '" + memfunc + "' on " + type + " that contains a reference.");
}
//---------------------------------------------------------------------------
// ClassCheck: "void operator=(" and "const type & operator=("
//---------------------------------------------------------------------------
void CheckClass::operatorEq()
{
if (!_settings->isEnabled("style"))
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
std::list<Function>::const_iterator func;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
if (func->type == Function::eOperatorEqual && func->access != Private) {
// use definition for check so we don't have to deal with qualification
if (!(Token::Match(func->retDef, "%type% &") && func->retDef->str() == scope->className)) {
// make sure we really have a copy assignment operator
if (Token::Match(func->tokenDef->tokAt(2), "const| %var% &")) {
if (func->tokenDef->strAt(2) == "const" &&
func->tokenDef->strAt(3) == scope->className)
operatorEqReturnError(func->retDef, scope->className);
else if (func->tokenDef->strAt(2) == scope->className)
operatorEqReturnError(func->retDef, scope->className);
}
}
}
}
}
}
void CheckClass::operatorEqReturnError(const Token *tok, const std::string &className)
{
reportError(tok, Severity::style, "operatorEq", "'" + className + "::operator=' should return '" + className + " &'.\n"
"The "+className+"::operator= does not conform to standard C/C++ behaviour. To conform to standard C/C++ behaviour, return a reference to self (such as: '"+className+" &"+className+"::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."
);
}
//---------------------------------------------------------------------------
// ClassCheck: "C& operator=(const C&) { ... return *this; }"
// operator= should return a reference to *this
//---------------------------------------------------------------------------
void CheckClass::operatorEqRetRefThis()
{
if (!_settings->isEnabled("style"))
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
std::list<Function>::const_iterator func;
for (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->classStart, func->functionScope->classEnd);
}
}
}
}
}
void CheckClass::checkReturnPtrThis(const Scope *scope, const Function *func, const Token *tok, const Token *last)
{
bool foundReturn = false;
for (; tok && tok != last; tok = tok->next()) {
// check for return of reference to this
if (tok->str() == "return") {
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() == ";") {
std::list<Function>::const_iterator it;
// check if it is a member function
for (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 */
// make sure it's not the same function
if (&*it != func)
checkReturnPtrThis(scope, &*it, it->arg->link()->next(), it->arg->link()->next()->link());
// 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)
operatorEqRetRefThisError(func->token);
}
void CheckClass::operatorEqRetRefThisError(const Token *tok)
{
reportError(tok, Severity::style, "operatorEqRetRefThis", "'operator=' should return reference to 'this' instance.");
}
//---------------------------------------------------------------------------
// 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 (!_settings->isEnabled("warning"))
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
std::list<Function>::const_iterator func;
// skip classes with multiple inheritance
if (scope->definedType->derivedFrom.size() > 1)
continue;
for (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->classEnd;
for (const Token *tok = func->functionScope->classStart; 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 = nullptr;
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();
// Check for assignment to the deleted pointer (only if its a member of the class)
if (var && isMemberVar(scope, var)) {
for (const Token *tok1 = var->next(); tok1 && (tok1 != last); tok1 = tok1->next()) {
if (Token::Match(tok1, "%var% =")) {
if (tok1->str() == var->str())
return true;
}
}
}
}
return false;
}
bool CheckClass::hasAssignSelf(const Function *func, const Token *rhs)
{
const Token *last = func->functionScope->classEnd;
for (const Token *tok = func->functionScope->classStart; tok && tok != last; tok = tok->next()) {
if (Token::simpleMatch(tok, "if (")) {
const Token *tok1 = tok->tokAt(2);
const Token *tok2 = tok->next()->link();
if (tok1 && tok2) {
for (; tok1 && tok1 != tok2; tok1 = tok1->next()) {
if (Token::Match(tok1, "this ==|!= & %var%")) {
if (tok1->strAt(3) == rhs->str())
return true;
} else if (Token::Match(tok1, "& %var% ==|!= this")) {
if (tok1->strAt(1) == 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.");
}
//---------------------------------------------------------------------------
// 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
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
// Skip base classes
if (scope->definedType->derivedFrom.empty())
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 (unsigned int 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<unsigned int> basepointer;
for (std::size_t k = 0; k < symbolDatabase->getVariableListSize(); k++) {
const Variable* var = symbolDatabase->getVariableFromVarId(k);
if (var && var->isPointer() && var->type() == derivedFrom)
basepointer.insert(var->declarationId());
}
// pointer variables of type 'Base *' that should not be deleted
std::set<unsigned int> dontDelete;
// No deletion of derived class instance through base class pointer found => the code is ok
bool ok = true;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "[;{}] %var% =") &&
tok->next()->varId() > 0 &&
basepointer.find(tok->next()->varId()) != basepointer.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% ;") &&
tok->next()->varId() &&
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 *base_destructor = derivedFromScope->getDestructor();
const Token *base = nullptr;
if (base_destructor)
base = base_destructor->token;
// Check that there is a destructor..
if (!base_destructor) {
if (derivedFrom->derivedFrom.empty())
virtualDestructorError(derivedFrom->classDef, derivedFrom->name(), derivedClass->str());
} else if (!base_destructor->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 (base_destructor->access == Public)
virtualDestructorError(base, derivedFrom->name(), derivedClass->str());
}
}
}
}
}
}
void CheckClass::virtualDestructorError(const Token *tok, const std::string &Base, const std::string &Derived)
{
reportError(tok, Severity::error, "virtualDestructor", "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.");
}
//---------------------------------------------------------------------------
// warn for "this-x". The indented code may be "this->x"
//---------------------------------------------------------------------------
void CheckClass::thisSubtraction()
{
if (!_settings->isEnabled("warning"))
return;
const Token *tok = _tokenizer->tokens();
for (;;) {
tok = Token::findmatch(tok, "this - %var%");
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 '->'?");
}
//---------------------------------------------------------------------------
// can member function be const?
//---------------------------------------------------------------------------
void CheckClass::checkConst()
{
// This is an inconclusive check. False positives: #3322.
if (!_settings->inconclusive)
return;
if (!_settings->isEnabled("style"))
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * scope = symbolDatabase->classAndStructScopes[i];
std::list<Function>::const_iterator func;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
// does the function have a body?
if (func->type == Function::eFunction && func->hasBody && !func->isFriend && !func->isStatic && !func->isVirtual) {
// 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;
while (!Token::Match(temp->previous(), ";|}|{|public:|protected:|private:")) {
temp = temp->previous();
if (temp->str() == "const")
break;
}
if (temp->str() != "const")
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 && opName[opName.size()-1] == '&')
continue;
} else {
// don't warn for unknown types..
// LPVOID, HDC, etc
if (previous->isUpperCaseName() && previous->str().size() > 2 && !symbolDatabase->isClassOrStruct(previous->str()))
continue;
}
// check if base class function is virtual
if (!scope->definedType->derivedFrom.empty()) {
if (func->isImplicitlyVirtual(true))
continue;
}
bool memberAccessed = false;
// if nothing non-const was found. write error..
if (checkConstFunc(&(*scope), &*func, memberAccessed)) {
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->isConst || (!memberAccessed && !func->isOperator)) {
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), "%var% . %var%")) {
tok = tok->tokAt(-2);
again = true;
} else if (Token::Match(tok->tokAt(-2), "] . %var%")) {
tok = tok->linkAt(-2)->previous();
again = true;
} else if (tok->str() == "]") {
tok = tok->link()->previous();
again = true;
}
} while (again);
std::list<Variable>::const_iterator var;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var) {
if (var->name() == tok->str()) {
if (tok->varId() == 0)
symbolDatabase->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() && !scope->definedType->hasCircularDependencies()) {
// check each base class
for (unsigned int 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;
}
static unsigned int countParameters(const Token *tok)
{
tok = tok->tokAt(2);
if (tok->str() == ")")
return 0;
unsigned int numpar = 1;
while (nullptr != (tok = tok->nextArgument()))
numpar++;
return numpar;
}
static unsigned int countMinArgs(const Token* argList)
{
if (!argList)
return 0;
argList = argList->next();
if (argList->str() == ")")
return 0;
unsigned int count = 1;
for (; argList; argList = argList->next()) {
if (argList->link() && Token::Match(argList, "(|[|{|<"))
argList = argList->link();
else if (argList->str() == ",")
count++;
else if (argList->str() == "=")
return count-1;
else if (argList->str() == ")")
break;
}
return count;
}
bool CheckClass::isMemberFunc(const Scope *scope, const Token *tok) const
{
unsigned int args = countParameters(tok);
for (std::list<Function>::const_iterator func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
/** @todo we need to look at the argument types when there are overloaded functions
* with the same number of arguments */
if (func->tokenDef->str() == tok->str() && (func->argCount() == args || (func->argCount() > args && countMinArgs(func->argDef) <= args))) {
return !func->isStatic;
}
}
// not found in this class
if (!scope->definedType->derivedFrom.empty()) {
// check each base class
for (unsigned int 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 && !derivedFrom->hasCircularDependencies()) {
if (isMemberFunc(derivedFrom->classScope, tok))
return true;
}
}
}
return false;
}
bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok) const
{
unsigned int args = countParameters(tok);
std::list<Function>::const_iterator func;
unsigned int matches = 0;
unsigned int consts = 0;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
/** @todo we need to look at the argument types when there are overloaded functions
* with the same number of arguments */
if (func->tokenDef->str() == tok->str() && (func->argCount() == args || (func->argCount() > args && countMinArgs(func->argDef) <= args))) {
matches++;
if (func->isConst)
consts++;
}
}
// if there are multiple matches that are all const, return const
if (matches > 0 && matches == consts)
return true;
// not found in this class
if (!scope->definedType->derivedFrom.empty()) {
// check each base class
for (unsigned int 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 && !derivedFrom->hasCircularDependencies()) {
if (isConstMemberFunc(derivedFrom->classScope, tok))
return true;
}
}
}
return false;
}
bool CheckClass::checkConstFunc(const Scope *scope, const Function *func, bool& memberAccessed)
{
// if the function doesn't have any assignment nor function call,
// it can be a const function..
for (const Token *tok1 = func->functionScope->classStart; tok1 && tok1 != func->functionScope->classEnd; 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* jumpBackToken = 0;
const Token *lastVarTok = tok1;
const Token *end = tok1;
for (;;) {
if (Token::Match(end->next(), ". %var%")) {
end = end->tokAt(2);
if (end->varId())
lastVarTok = end;
} else if (end->strAt(1) == "[") {
if (end->varId()) {
const Variable *var = end->variable();
// The container contains the STL types whose operator[] is not a const.
// THIS ARRAY MUST BE ORDERED ALPHABETICALLY
static const char* const stl_containers [] = {
"map", "unordered_map"
};
if (var && var->isStlType(stl_containers))
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()->type() == Token::eAssignmentOp)
return (false);
// Streaming
else if (end->strAt(1) == "<<" && tok1->strAt(-1) != "<<")
return (false);
else if (tok1->strAt(-1) == ">>")
return (false);
// ++/--
else if (end->next()->type() == Token::eIncDecOp || tok1->previous()->type() == 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, "%var% (") && !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
for (const Token* tok2 = tok1->tokAt(2); 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, 0, classname, funcname, suggestStatic);
}
void CheckClass::checkConstError2(const Token *tok1, const Token *tok2, const std::string &classname, const std::string &funcname, bool suggestStatic)
{
std::list<const Token *> toks;
toks.push_back(tok1);
if (tok2)
toks.push_back(tok2);
if (!suggestStatic)
reportError(toks, Severity::style, "functionConst",
"Technically the member function '" + classname + "::" + funcname + "' can be const.\n"
"The member function '" + classname + "::" + funcname + "' 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?", true);
else
reportError(toks, Severity::performance, "functionStatic",
"Technically the member function '" + classname + "::" + funcname + "' can be static.\n"
"The member function '" + classname + "::" + funcname + "' 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?", true);
}
//---------------------------------------------------------------------------
// ClassCheck: Check that initializer list is in declared order.
//---------------------------------------------------------------------------
struct VarInfo {
VarInfo(const Variable *_var, const Token *_tok)
: var(_var), tok(_tok) { }
const Variable *var;
const Token *tok;
};
void CheckClass::initializerListOrder()
{
if (!_settings->isEnabled("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 (!_settings->inconclusive)
return;
const std::size_t classes = symbolDatabase->classAndStructScopes.size();
for (std::size_t i = 0; i < classes; ++i) {
const Scope * info = symbolDatabase->classAndStructScopes[i];
std::list<Function>::const_iterator func;
// iterate through all member functions looking for constructors
for (func = info->functionList.begin(); func != info->functionList.end(); ++func) {
if ((func->isConstructor()) && func->hasBody) {
// check for initializer list
const Token *tok = func->arg->link()->next();
if (tok->str() == ":") {
std::vector<VarInfo> vars;
tok = tok->next();
// find all variable initializations in list
while (tok && tok->str() != "{") {
if (Token::Match(tok, "%var% (")) {
const Variable *var = info->getVariable(tok->str());
if (var)
vars.push_back(VarInfo(var, tok));
if (Token::Match(tok->tokAt(2), "%var% =")) {
var = info->getVariable(tok->strAt(2));
if (var)
vars.push_back(VarInfo(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(), info->className, vars[j].var->name());
}
}
}
}
}
}
void CheckClass::initializerListError(const Token *tok1, const Token *tok2, const std::string &classname, const std::string &varname)
{
std::list<const Token *> toks;
toks.push_back(tok1);
toks.push_back(tok2);
reportError(toks, Severity::style, "initializerList",
"Member variable '" + classname + "::" +
varname + "' is in the wrong place in the initializer list.\n"
"Member variable '" + classname + "::" +
varname + "' 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.", true);
}
void CheckClass::checkPureVirtualFunctionCall()
{
const std::size_t functions = symbolDatabase->functionScopes.size();
std::map<const Function *, std::list<const Token *> > callsPureVirtualFunctionMap;
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
if (scope->function == 0 || !scope->function->hasBody ||
!(scope->function->isConstructor() ||
scope->function->isDestructor()))
continue;
const std::list<const Token *> & pureVirtualFunctionCalls=callsPureVirtualFunction(*scope->function,callsPureVirtualFunctionMap);
for (std::list<const Token *>::const_iterator pureCallIter=pureVirtualFunctionCalls.begin();
pureCallIter!=pureVirtualFunctionCalls.end();
++pureCallIter) {
const Token & pureCall=**pureCallIter;
std::list<const Token *> pureFuncStack;
pureFuncStack.push_back(&pureCall);
getFirstPureVirtualFunctionCallStack(callsPureVirtualFunctionMap, pureCall, pureFuncStack);
if (!pureFuncStack.empty())
callsPureVirtualFunctionError(*scope->function, pureFuncStack, pureFuncStack.back()->str());
}
}
}
void CheckClass::checkDuplInheritedMembers()
{
if (!_settings->isEnabled("warning"))
return;
// Iterate over all classes
for (std::list<Type>::const_iterator classIt = symbolDatabase->typeList.begin();
classIt != symbolDatabase->typeList.end();
++classIt) {
// Iterate over the parent classes
for (std::vector<Type::BaseInfo>::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<Variable>::const_iterator classVarIt = classIt->classScope->varlist.begin();
classVarIt != classIt->classScope->varlist.end();
++classVarIt) {
for (std::list<Variable>::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<const Token *> toks;
toks.push_back(tok1);
toks.push_back(tok2);
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", message);
}
const std::list<const Token *> & CheckClass::callsPureVirtualFunction(const Function & function,
std::map<const Function *, std::list<const Token *> > & callsPureVirtualFunctionMap)
{
std::pair<std::map<const Function *, std::list<const Token *> >::iterator , bool > found=
callsPureVirtualFunctionMap.insert(std::pair<const Function *, std::list< const Token *> >(&function,std::list<const Token *>()));
std::list<const Token *> & pureFunctionCalls=found.first->second;
if (found.second) {
if (function.hasBody) {
for (const Token *tok = function.arg->link();
tok && tok != function.functionScope->classEnd;
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;
}
}
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() &&
(_settings->library.ignorefunction(tok->str())
|| _settings->library.ignorefunction(prev->previous()->str())))
continue;
}
if (isPureWithoutBody(*callFunction)) {
pureFunctionCalls.push_back(tok);
continue;
}
const std::list<const Token *> & pureFunctionCallsOfTok=callsPureVirtualFunction(*callFunction,
callsPureVirtualFunctionMap);
if (!pureFunctionCallsOfTok.empty()) {
pureFunctionCalls.push_back(tok);
continue;
}
}
}
}
return pureFunctionCalls;
}
void CheckClass::getFirstPureVirtualFunctionCallStack(
std::map<const Function *, std::list<const Token *> > & callsPureVirtualFunctionMap,
const Token & pureCall,
std::list<const Token *> & pureFuncStack)
{
if (isPureWithoutBody(*pureCall.function())) {
pureFuncStack.push_back(pureCall.function()->token);
return;
}
std::map<const Function *, std::list<const Token *> >::const_iterator found=callsPureVirtualFunctionMap.find(pureCall.function());
if (found==callsPureVirtualFunctionMap.end() ||
found->second.empty()) {
pureFuncStack.clear();
return;
}
const Token & firstPureCall=**found->second.begin();
pureFuncStack.push_back(&firstPureCall);
getFirstPureVirtualFunctionCallStack(callsPureVirtualFunctionMap, firstPureCall, pureFuncStack);
}
void CheckClass::callsPureVirtualFunctionError(
const Function & scopeFunction,
const std::list<const Token *> & tokStack,
const std::string &purefuncname)
{
const char * scopeFunctionTypeName=getFunctionTypeName(scopeFunction.type);
reportError(tokStack, Severity::warning, "pureVirtualCall", "Call of pure virtual function '" + purefuncname + "' in " + scopeFunctionTypeName + ".\n"
"Call of pure virtual function '" + purefuncname + "' in " + scopeFunctionTypeName + ". The call will fail during runtime.");
}
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