/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2011 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 .
*/
//---------------------------------------------------------------------------
#include "checkclass.h"
#include "tokenize.h"
#include "token.h"
#include "errorlogger.h"
#include "symboldatabase.h"
#include
#include
#include
#include
#include
//---------------------------------------------------------------------------
// Register CheckClass..
namespace
{
CheckClass instance;
}
//---------------------------------------------------------------------------
CheckClass::CheckClass(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
: Check(myName(), tokenizer, settings, errorLogger),
symbolDatabase(NULL)
{
}
void CheckClass::createSymbolDatabase()
{
// Multiple calls => bail out
if (symbolDatabase)
return;
symbolDatabase = _tokenizer->getSymbolDatabase();
}
//---------------------------------------------------------------------------
// ClassCheck: Check that all class constructors are ok.
//---------------------------------------------------------------------------
void CheckClass::constructors()
{
if (!_settings->_checkCodingStyle)
return;
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (!scope->isClassOrStruct())
continue;
// There are no constructors.
if (scope->numConstructors == 0)
{
// If there is a private variable, there should be a constructor..
std::list::const_iterator var;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var)
{
if (var->isPrivate() && !var->isClass() && !var->isStatic())
{
noConstructorError(scope->classDef, scope->className, scope->classDef->str() == "struct");
break;
}
}
}
std::list::const_iterator func;
std::vector usage(scope->varlist.size());
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
if (!func->hasBody || !(func->type == Function::eConstructor ||
func->type == Function::eCopyConstructor ||
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
std::list::const_iterator var;
unsigned int count = 0;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var, ++count)
{
if (usage[count].assign || usage[count].init || var->isStatic())
continue;
if (var->isConst() && var->nameToken()->previous()->str() != "*")
continue;
// Check if this is a class constructor
if (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 != Scope::True)
continue;
}
// Check if type can't be copied
if (var->type() && canNotCopy(var->type()))
continue;
// It's non-static and it's not initialized => error
if (func->type == Function::eOperatorEqual)
{
const Token *operStart = func->token->tokAt(1);
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());
}
else if (func->access != Private)
uninitVarError(func->token, scope->className, var->name());
}
}
}
}
bool CheckClass::canNotCopy(const Scope *scope) const
{
std::list::const_iterator func;
bool privateAssign = false;
bool privateCopy = false;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
if (func->type == Function::eCopyConstructor && func->access == Private)
privateCopy = true;
else if (func->type == Function::eOperatorEqual && func->access == Private)
privateAssign = true;
}
return privateAssign && privateCopy;
}
void CheckClass::assignVar(const std::string &varname, const Scope *scope, std::vector &usage)
{
std::list::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)
{
std::list::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)
{
for (size_t i = 0; i < usage.size(); ++i)
usage[i].assign = true;
}
void CheckClass::clearAllVar(std::vector &usage)
{
for (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 (size_t i = 0; i < scope->derivedFrom.size(); ++i)
{
const Scope *derivedFrom = scope->derivedFrom[i].scope;
// Check if base class exists in database
if (derivedFrom)
{
std::list::const_iterator func;
for (func = derivedFrom->functionList.begin(); func != derivedFrom->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)
{
bool Assign = false;
unsigned int indentlevel = 0;
const Token *ftok = func.token;
for (; ftok; ftok = ftok->next())
{
if (!ftok->next())
break;
// Class constructor.. initializing variables like this
// clKalle::clKalle() : var(value) { }
if (indentlevel == 0)
{
if (Assign && Token::Match(ftok, "%var% ("))
{
initVar(ftok->str(), scope, usage);
// assignment in the initializer..
// : var(value = x)
if (Token::Match(ftok->tokAt(2), "%var% ="))
assignVar(ftok->strAt(2), scope, usage);
}
Assign |= (ftok->str() == ":");
}
if (ftok->str() == "{")
{
++indentlevel;
Assign = false;
}
else if (ftok->str() == "}")
{
if (indentlevel <= 1)
break;
--indentlevel;
}
if (indentlevel < 1)
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;
}
// Calling member variable function?
if (Token::Match(ftok->next(), "%var% . %var% ("))
{
std::list::const_iterator var;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var)
{
if (var->varId() == ftok->next()->varId())
{
/** @todo false negative: we assume function changes variable state */
assignVar(ftok->next()->str(), scope, usage);
continue;
}
}
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 "( * 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->tokAt(2);
// Clearing all variables..
if (Token::simpleMatch(ftok, "memset ( this ,"))
{
assignAllVar(usage);
return;
}
// Clearing array..
else if (Token::Match(ftok, "memset ( %var% ,"))
{
assignVar(ftok->strAt(2), scope, usage);
ftok = ftok->next()->link();
continue;
}
// Calling member function?
else if (Token::simpleMatch(ftok, "operator= (") &&
ftok->previous()->str() != "::")
{
// check if member function exists
std::list::const_iterator it;
for (it = scope->functionList.begin(); it != scope->functionList.end(); ++it)
{
if (ftok->str() == it->tokenDef->str() && it->type != Function::eConstructor)
break;
}
// member function found
if (it != scope->functionList.end())
{
// member function has implementation
if (it->hasBody)
{
// initialize variable use list using member function
callstack.push_back(ftok->str());
initializeVarList(*it, 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")
{
// 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;
}
}
// recursive call / calling overloaded function
// assume that all variables are initialized
if (std::find(callstack.begin(), callstack.end(), ftok->str()) != callstack.end())
{
assignAllVar(usage);
return;
}
// check if member function
std::list::const_iterator it;
for (it = scope->functionList.begin(); it != scope->functionList.end(); ++it)
{
if (ftok->str() == it->tokenDef->str() && it->type != Function::eConstructor)
break;
}
// member function found
if (it != scope->functionList.end())
{
// member function has implementation
if (it->hasBody)
{
// initialize variable use list using member function
callstack.push_back(ftok->str());
initializeVarList(*it, 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);
}
}
// not member function
else
{
// could be a base class virtual function, so we assume it initializes everything
if (func.type != Function::eConstructor && 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->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
{
unsigned int indentlevel2 = 0;
for (const Token *tok = ftok->tokAt(2); tok; tok = tok->next())
{
if (tok->str() == "(")
++indentlevel2;
else if (tok->str() == ")")
{
if (indentlevel2 == 0)
break;
--indentlevel2;
}
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% [") &&
Token::simpleMatch(ftok->next()->link(), "] ="))
{
assignVar(ftok->str(), scope, usage);
}
// Assignment of member of array item of member variable?
else if (Token::Match(ftok, "%var% [ ") &&
(Token::Match(ftok->next()->link(), "] . %var% =") ||
Token::Match(ftok->next()->link(), "] . %var% . %var% =")))
{
assignVar(ftok->str(), scope, usage);
}
// Assignment of array item of member variable?
else if (Token::Match(ftok, "%var% [") &&
Token::simpleMatch(ftok->next()->link(), "] [") &&
Token::simpleMatch(ftok->next()->link()->next()->link(), "] ="))
{
assignVar(ftok->str(), scope, usage);
}
// Assignment of array item of member variable?
else if (Token::Match(ftok, "* %var% ="))
{
assignVar(ftok->next()->str(), scope, usage);
}
// Assignment of struct member of member variable?
else if (Token::Match(ftok, "%var% . %any% ="))
{
assignVar(ftok->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 but it has attributes. "
"The attributes are not initialized which may cause bugs or undefined behavior.");
}
void CheckClass::uninitVarError(const Token *tok, const std::string &classname, const std::string &varname)
{
reportError(tok, Severity::warning, "uninitVar", "Member variable '" + classname + "::" + varname + "' is not initialized in the constructor.");
}
void CheckClass::operatorEqVarError(const Token *tok, const std::string &classname, const std::string &varname)
{
reportError(tok, Severity::warning, "operatorEqVarError", "Member variable '" + classname + "::" + varname + "' is not assigned a value in '" + classname + "::operator=" + "'");
}
//---------------------------------------------------------------------------
// ClassCheck: Unused private functions
//---------------------------------------------------------------------------
void CheckClass::privateFunctions()
{
if (!_settings->_checkCodingStyle)
return;
// don't check code that contains templates. Templates that are
// "unused" are removed from the code. #2067
if (_tokenizer->codeWithTemplates())
return;
// dont check borland classes with properties..
if (Token::findmatch(_tokenizer->tokens(), "; __property ;"))
return;
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (!scope->isClassOrStruct())
continue;
// don’t check derived classes
if (!scope->derivedFrom.empty())
continue;
// skip checking if there are friends
if (!scope->friendList.empty())
continue;
// Locate some class
const Token *tok1 = scope->classDef;
// check that the whole class implementation is seen
bool whole = true;
std::list::const_iterator func;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
if (!func->hasBody)
{
// empty private copy constructors and assignment operators are OK
if ((func->type == Function::eCopyConstructor ||
func->type == Function::eOperatorEqual) &&
func->access == Private)
continue;
whole = false;
break;
}
}
if (!whole)
continue;
const std::string &classname = tok1->next()->str();
std::list FuncList;
/** @todo embedded class have access to private functions */
if (!scope->getNestedNonFunctions())
{
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
// Get private functions..
if (func->type == Function::eFunction && func->access == Private)
FuncList.push_back(func->tokenDef);
}
}
// Check that all private functions are used..
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
const Token *ftok = func->start;
if (ftok)
{
const Token *etok = ftok->link();
for (; ftok != etok; ftok = ftok->next())
{
if (Token::Match(ftok, "%var% ("))
{
// Remove function from FuncList
std::list::iterator it = FuncList.begin();
while (it != FuncList.end())
{
if (ftok->str() == (*it)->str())
FuncList.erase(it++);
else
++it;
}
}
}
}
}
while (!FuncList.empty())
{
// Final check; check if the function pointer is used somewhere..
const std::string _pattern("return|(|)|,|= &|" + FuncList.front()->str());
// or if the function address is used somewhere...
// eg. sigc::mem_fun(this, &className::classFunction)
const std::string _pattern2("& " + classname + " :: " + FuncList.front()->str());
const std::string methodAsArgument("(|, " + classname + " :: " + FuncList.front()->str() + " ,|)");
if (!Token::findmatch(_tokenizer->tokens(), _pattern.c_str()) &&
!Token::findmatch(_tokenizer->tokens(), _pattern2.c_str()) &&
!Token::findmatch(_tokenizer->tokens(), methodAsArgument.c_str())
)
{
unusedPrivateFunctionError(FuncList.front(), classname, FuncList.front()->str());
}
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
//---------------------------------------------------------------------------
void CheckClass::noMemset()
{
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
std::list::const_iterator func;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
// only check functions with bodies
if (!func->hasBody)
continue;
// Locate all 'memset' tokens..
const Token *end = func->start->link();
for (const Token *tok = func->start; tok && tok != end; tok = tok->next())
{
if (!Token::Match(tok, "memset|memcpy|memmove"))
continue;
const Token *typeTok = 0;
if (Token::Match(tok, "memset ( %var% , %num% , sizeof ( %type% ) )"))
typeTok = tok->tokAt(8);
else if (Token::Match(tok, "memset ( & %var% , %num% , sizeof ( %type% ) )"))
typeTok = tok->tokAt(9);
else if (Token::Match(tok, "memset ( & %var% , %num% , sizeof ( %type% :: %type% ) )"))
typeTok = tok->tokAt(11);
else if (Token::Match(tok, "memset ( %var% , %num% , sizeof ( struct %type% ) )"))
typeTok = tok->tokAt(9);
else if (Token::Match(tok, "memset ( & %var% , %num% , sizeof ( struct %type% ) )"))
typeTok = tok->tokAt(10);
else if (Token::Match(tok, "%type% ( %var% , %var% , sizeof ( %type% ) )"))
typeTok = tok->tokAt(8);
else if (Token::Match(tok, "memset ( & %var% , %num% , sizeof ( %var% ) )"))
{
unsigned int varid = tok->tokAt(3)->varId();
const Variable *var = symbolDatabase->getVariableFromVarId(varid);
if (var && (var->typeStartToken() == var->typeEndToken() ||
Token::Match(var->typeStartToken(), "%type% :: %type%")))
typeTok = var->typeEndToken();
}
// No type defined => The tokens didn't match
if (!typeTok)
continue;
const Scope *type = symbolDatabase->findVariableType(&(*scope), typeTok);
if (type)
checkMemsetType(&(*scope), tok, type);
}
}
}
}
void CheckClass::checkMemsetType(const Scope *start, const Token *tok, const Scope *type)
{
// recursively check all parent classes
for (size_t i = 0; i < type->derivedFrom.size(); i++)
{
if (type->derivedFrom[i].scope)
checkMemsetType(start, tok, type->derivedFrom[i].scope);
}
// 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)
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)
{
// don't warn if variable static or const
if (!var->isStatic() && !var->isConst())
{
const Token *tok1 = var->typeStartToken();
// check for std:: type that is not a pointer or reference
if (Token::simpleMatch(tok1, "std ::") && !Token::Match(var->nameToken()->previous(), "*|&"))
memsetError(tok, tok->str(), "'std::" + tok1->strAt(2) + "'", type->classDef->str());
// check for known type that is not a pointer or reference
else if (var->type() && !Token::Match(var->nameToken()->previous(), "*|&"))
checkMemsetType(start, tok, var->type());
}
}
}
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);
}
//---------------------------------------------------------------------------
// ClassCheck: "void operator=(" and "const type & operator=("
//---------------------------------------------------------------------------
void CheckClass::operatorEq()
{
if (!_settings->_checkCodingStyle)
return;
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
if (!scope->isClassOrStruct())
continue;
std::list::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->tokenDef->tokAt(-3), ";|}|{|public:|protected:|private: %type% &") &&
func->tokenDef->strAt(-2) == scope->className))
operatorEqReturnError(func->tokenDef->tokAt(-1), scope->className);
}
}
}
}
void CheckClass::operatorEqReturnError(const Token *tok, const std::string &className)
{
reportError(tok, Severity::style, "operatorEq", "\'" + className + "::operator=' should return \'" + className + " &\'");
}
//---------------------------------------------------------------------------
// ClassCheck: "C& operator=(const C&) { ... return *this; }"
// operator= should return a reference to *this
//---------------------------------------------------------------------------
void CheckClass::operatorEqRetRefThis()
{
if (!_settings->_checkCodingStyle)
return;
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (scope->isClassOrStruct())
{
std::list::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->tokenDef->tokAt(-3), ";|}|{|public:|protected:|private: %type% &") &&
func->tokenDef->strAt(-2) == scope->className)
{
// find the ')'
const Token *tok = func->token->next()->link();
checkReturnPtrThis(&(*scope), &(*func), tok->tokAt(2), tok->next()->link());
}
}
}
}
}
}
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::Match(tok->next(), cast.c_str()))
tok = tok->tokAt(4);
// check if a function is called
if (Token::Match(tok->tokAt(1), "%any% (") &&
tok->tokAt(2)->link()->next()->str() == ";")
{
std::list::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->arg->link()->next()->str() != "const")
{
/** @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->tokAt(1), "(| * this ;|=") ||
Token::Match(tok->tokAt(1), "(| * this +=") ||
Token::simpleMatch(tok->tokAt(1), "operator= (") ||
Token::simpleMatch(tok->tokAt(1), "this . operator= (") ||
(Token::Match(tok->tokAt(1), "%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 self");
}
//---------------------------------------------------------------------------
// 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->_checkCodingStyle)
return;
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
if (!scope->isClassOrStruct())
continue;
std::list::const_iterator func;
// skip classes with multiple inheritance
if (scope->derivedFrom.size() > 1)
continue;
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->tokenDef->tokAt(-3), ";|}|{|public:|protected:|private: %type% &") &&
func->tokenDef->strAt(-2) == scope->className)
{
// find the parameter name
const Token *rhs = func->argumentList.begin()->nameToken();
if (!hasAssignSelf(&(*func), rhs))
{
if (hasDeallocation(&(*func)))
operatorEqToSelfError(func->token);
}
}
}
}
}
}
bool CheckClass::hasDeallocation(const Function *func)
{
// This function is called when no simple check was found for assignment
// to self. We are currently looking for a specific sequence of:
// deallocate member ; ... member = allocate
// This check is far from ideal because it can cause false negatives.
// Unfortunately, this is necessary to prevent false positives.
// This check needs to do careful analysis someday to get this
// correct with a high degree of certainty.
const Token *last = func->start->link();
for (const Token *tok = func->start; tok && (tok != last); tok = tok->next())
{
// check for deallocating memory
if (Token::Match(tok, "{|;|, free ( %var%"))
{
const Token *var = tok->tokAt(3);
// we should probably check that var is a pointer in this class
const Token *tok1 = tok->tokAt(4);
while (tok1 && (tok1 != last))
{
if (Token::Match(tok1, "%var% ="))
{
if (tok1->str() == var->str())
return true;
}
tok1 = tok1->next();
}
}
else if (Token::Match(tok, "{|;|, delete [ ] %var%"))
{
const Token *var = tok->tokAt(4);
// we should probably check that var is a pointer in this class
const Token *tok1 = tok->tokAt(5);
while (tok1 && (tok1 != last))
{
if (Token::Match(tok1, "%var% = new %type% ["))
{
if (tok1->str() == var->str())
return true;
}
tok1 = tok1->next();
}
}
else if (Token::Match(tok, "{|;|, delete %var%"))
{
const Token *var = tok->tokAt(2);
// we should probably check that var is a pointer in this class
const Token *tok1 = tok->tokAt(3);
while (tok1 && (tok1 != last))
{
if (Token::Match(tok1, "%var% = new"))
{
if (tok1->str() == var->str())
return true;
}
tok1 = tok1->next();
}
}
}
return false;
}
bool CheckClass::hasAssignSelf(const Function *func, const Token *rhs)
{
const Token *last = func->start->link();
for (const Token *tok = func->start; tok && tok != last; tok = tok->next())
{
if (Token::simpleMatch(tok, "if ("))
{
const Token *tok1 = tok->tokAt(2);
const Token *tok2 = tok->tokAt(1)->link();
if (tok1 && tok2)
{
for (; tok1 && tok1 != tok2; tok1 = tok1->next())
{
if (Token::Match(tok1, "this ==|!= & %var%"))
{
if (tok1->tokAt(3)->str() == rhs->str())
return true;
}
else if (Token::Match(tok1, "& %var% ==|!= this"))
{
if (tok1->tokAt(1)->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");
}
//---------------------------------------------------------------------------
// 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
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// Skip base classes and namespaces
if (scope->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->tokAt(3)->link() == destructor->token->tokAt(4))
continue;
const Token *derived = scope->classDef;
const Token *derivedClass = derived->tokAt(1);
// Iterate through each base class...
for (unsigned int j = 0; j < scope->derivedFrom.size(); ++j)
{
// Check if base class is public and exists in database
if (scope->derivedFrom[j].access != Private && scope->derivedFrom[j].scope)
{
const Scope *derivedFrom = scope->derivedFrom[j].scope;
// Name of base class..
const std::string baseName = derivedFrom->className;
// 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 basepointer;
// 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 = _tokenizer->tokens(); tok; tok = tok->next())
{
// Declaring base class pointer
if (Token::simpleMatch(tok, baseName.c_str()))
{
if (Token::Match(tok->previous(), ("[;{}] " + baseName + " * %var% ;").c_str()))
basepointer.insert(tok->tokAt(2)->varId());
}
// Assign base class pointer with pointer to derived class instance
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
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 = derivedFrom->getDestructor();
const Token *base = 0;
if (base_destructor)
base = base_destructor->token;
// Check that there is a destructor..
if (!base_destructor)
{
if (derivedFrom->derivedFrom.empty())
virtualDestructorError(derivedFrom->classDef, baseName, 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, baseName, 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");
}
//---------------------------------------------------------------------------
// warn for "this-x". The indented code may be "this->x"
//---------------------------------------------------------------------------
void CheckClass::thisSubtraction()
{
if (!_settings->_checkCodingStyle)
return;
const Token *tok = _tokenizer->tokens();
for (;;)
{
tok = Token::findmatch(tok, "this - %var%");
if (!tok)
break;
if (!Token::simpleMatch(tok->previous(), "*"))
thisSubtractionError(tok);
tok = tok->next();
}
}
void CheckClass::thisSubtractionError(const Token *tok)
{
reportError(tok, Severity::warning, "thisSubtraction", "Suspicious pointer subtraction");
}
//---------------------------------------------------------------------------
// can member function be const?
//---------------------------------------------------------------------------
void CheckClass::checkConst()
{
if (!_settings->isEnabled("information") || _settings->ifcfg)
return;
// Don't check C# and JAVA classes
if (_tokenizer->isJavaOrCSharp())
{
return;
}
createSymbolDatabase();
std::list::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (!scope->isClassOrStruct())
continue;
std::list::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->isConst && !func->isVirtual)
{
// get last token of return type
const Token *previous = func->tokenDef->isName() ? func->token->previous() : func->token->tokAt(-2);
while (previous && previous->str() == "::")
previous = previous->tokAt(-2);
// does the function return a pointer or reference?
if (Token::Match(previous, "*|&"))
{
const Token *temp = func->token->previous();
while (!Token::Match(temp->previous(), ";|}|{|public:|protected:|private:"))
temp = temp->previous();
if (temp->str() != "const")
continue;
}
else if (Token::Match(previous->previous(), "*|& >"))
{
const Token *temp = func->token->previous();
while (!Token::Match(temp->previous(), ";|}|{|public:|protected:|private:"))
{
temp = temp->previous();
if (temp->str() == "const")
break;
}
if (temp->str() != "const")
continue;
}
else
{
// don't warn for unknown types..
// LPVOID, HDC, etc
if (previous->isName())
{
bool allupper = true;
const std::string s(previous->str());
for (std::string::size_type pos = 0; pos < s.size(); ++pos)
{
const char ch = s[pos];
if (!(ch == '_' || (ch >= 'A' && ch <= 'Z')))
{
allupper = false;
break;
}
}
if (allupper && previous->str().size() > 2)
continue;
}
}
const Token *paramEnd = func->arg->link();
// check if base class function is virtual
if (!scope->derivedFrom.empty())
{
if (isVirtualFunc(&(*scope), func->tokenDef))
continue;
}
// if nothing non-const was found. write error..
if (checkConstFunc(&(*scope), paramEnd))
{
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);
else // not inline
checkConstError2(func->token, func->tokenDef, classname, functionName);
}
}
}
}
}
bool CheckClass::isMemberVar(const Scope *scope, const Token *tok)
{
bool again = false;
// try to find the member variable
do
{
again = false;
if (tok->str() == "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->tokAt(-2)->link()->previous();
again = true;
}
else if (tok->str() == "]")
{
tok = tok->link()->previous();
again = true;
}
}
while (again);
std::list::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->isMutable();
}
}
// not found in this class
if (!scope->derivedFrom.empty())
{
// check each base class
for (unsigned int i = 0; i < scope->derivedFrom.size(); ++i)
{
// find the base class
const Scope *derivedFrom = scope->derivedFrom[i].scope;
// find the function in the base class
if (derivedFrom)
{
if (isMemberVar(derivedFrom, tok))
return true;
}
}
}
return false;
}
static int countParameters(const Token *tok)
{
if (Token::Match(tok->tokAt(2), "void| )"))
return 0;
int numpar = 1;
int parlevel = 0;
for (; tok; tok = tok->next())
{
if (tok->str() == "(")
++parlevel;
else if (tok->str() == ")")
{
if (parlevel <= 1)
break;
--parlevel;
}
else if (parlevel == 1 && tok->str() == ",")
{
++numpar;
}
}
return numpar;
}
bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok)
{
unsigned int args = countParameters(tok);
std::list::const_iterator func;
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->isConst)
return true;
}
// not found in this class
if (!scope->derivedFrom.empty())
{
// check each base class
for (unsigned int i = 0; i < scope->derivedFrom.size(); ++i)
{
// find the base class
const Scope *derivedFrom = scope->derivedFrom[i].scope;
// find the function in the base class
if (derivedFrom)
{
if (isConstMemberFunc(derivedFrom, tok))
return true;
}
}
}
return false;
}
bool CheckClass::checkConstFunc(const Scope *scope, const Token *tok)
{
// if the function doesn't have any assignment nor function call,
// it can be a const function..
unsigned int indentlevel = 0;
bool isconst = true;
for (const Token *tok1 = tok; tok1; tok1 = tok1->next())
{
if (tok1->str() == "{")
++indentlevel;
else if (tok1->str() == "}")
{
if (indentlevel <= 1)
break;
--indentlevel;
}
// assignment.. = += |= ..
else if (tok1->isAssignmentOp())
{
if (tok1->next()->str() == "this")
{
isconst = false;
break;
}
else if (isMemberVar(scope, tok1->previous()))
{
isconst = false;
break;
}
}
// streaming: <<
else if (tok1->str() == "<<" && isMemberVar(scope, tok1->previous()))
{
isconst = false;
break;
}
else if (Token::simpleMatch(tok1->previous(), ") <<") &&
isMemberVar(scope, tok1->tokAt(-2)))
{
isconst = false;
break;
}
// increment/decrement (member variable?)..
else if (Token::Match(tok1, "++|--"))
{
// var++ and var--
if (Token::Match(tok1->previous(), "%var%") &&
tok1->previous()->str() != "return")
{
if (isMemberVar(scope, tok1->previous()))
{
isconst = false;
break;
}
}
// var[...]++ and var[...]--
else if (tok1->previous()->str() == "]")
{
if (isMemberVar(scope, tok1->previous()->link()->previous()))
{
isconst = false;
break;
}
}
// ++var and --var
else if (Token::Match(tok1->next(), "%var%"))
{
if (isMemberVar(scope, tok1->next()))
{
isconst = false;
break;
}
}
}
// std::map variable member
else if (Token::Match(tok1, "%var% [") && isMemberVar(scope, tok1))
{
const Variable *var = symbolDatabase->getVariableFromVarId(tok1->varId());
if (var && (var->typeStartToken()->str() == "map" ||
Token::simpleMatch(var->typeStartToken(), "std :: map")))
{
isconst = false;
break;
}
}
// function call..
else if (Token::Match(tok1, "%var% (") &&
!(Token::Match(tok1, "return|c_str|if|string") || tok1->isStandardType()))
{
if (!isConstMemberFunc(scope, tok1))
{
isconst = false;
break;
}
}
else if (Token::Match(tok1, "%var% < %any% > ("))
{
isconst = false;
break;
}
else if (Token::Match(tok1, "%var% . size ( )") && tok1->varId())
{
// STL container size() is const
static const char STL_CONTAINER_LIST[] = "bitset|deque|list|map|multimap|multiset|priority_queue|queue|set|stack|hash_map|hash_multimap|hash_set|string|vector";
const Variable *var = symbolDatabase->getVariableFromVarId(tok1->varId());
if (var)
{
const Token *tok2 = var->typeStartToken();
// skip namespace if present
if (Token::simpleMatch(tok2, "std ::"))
tok2 = tok2->tokAt(2);
// check for STL container
if (Token::Match(tok2, STL_CONTAINER_LIST))
tok1 = tok1->tokAt(4);
}
}
// delete..
else if (tok1->str() == "delete")
{
isconst = false;
break;
}
}
return isconst;
}
// check if this function is defined virtual in the base classes
bool CheckClass::isVirtualFunc(const Scope *scope, const Token *functionToken) const
{
// check each base class
for (unsigned int i = 0; i < scope->derivedFrom.size(); ++i)
{
// check if base class exists in database
if (scope->derivedFrom[i].scope)
{
const Scope *derivedFrom = scope->derivedFrom[i].scope;
std::list::const_iterator func;
// check if function defined in base class
for (func = derivedFrom->functionList.begin(); func != derivedFrom->functionList.end(); ++func)
{
if (func->isVirtual)
{
const Token *tok = func->tokenDef;
if (tok->str() == functionToken->str())
{
const Token *temp1 = tok->previous();
const Token *temp2 = functionToken->previous();
bool returnMatch = true;
// check for matching return parameters
while (temp1->str() != "virtual")
{
if (temp1->str() != temp2->str())
{
returnMatch = false;
break;
}
temp1 = temp1->previous();
temp2 = temp2->previous();
}
// check for matching function parameters
if (returnMatch && symbolDatabase->argsMatch(scope, tok->tokAt(2), functionToken->tokAt(2), std::string(""), 0))
{
return true;
}
}
}
}
if (!derivedFrom->derivedFrom.empty())
{
if (isVirtualFunc(derivedFrom, functionToken))
return true;
}
}
else
{
// unable to find base class so assume it has a virtual function
return true;
}
}
return false;
}
void CheckClass::checkConstError(const Token *tok, const std::string &classname, const std::string &funcname)
{
reportError(tok, Severity::information, "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 function 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 task of the function first - is "
"it a function that must not change object internal state?");
}
void CheckClass::checkConstError2(const Token *tok1, const Token *tok2, const std::string &classname, const std::string &funcname)
{
std::list toks;
toks.push_back(tok1);
toks.push_back(tok2);
reportError(toks, Severity::information, "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 function 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 task of the function first - is "
"it a function that must not change object internal state?");
}