cppcheck/lib/checkclass.cpp

1669 lines
58 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* 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 <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
#include "checkclass.h"
#include "tokenize.h"
#include "token.h"
#include "errorlogger.h"
#include "symboldatabase.h"
#include <locale>
#include <cstring>
#include <string>
#include <sstream>
#include <algorithm>
//---------------------------------------------------------------------------
// 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<Scope>::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<Variable>::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<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->type == Function::eConstructor ||
func->type == Function::eCopyConstructor ||
func->type == Function::eOperatorEqual))
continue;
// Mark all variables not used
clearAllVar(usage);
std::list<std::string> 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)
{
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<Function>::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> &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 (size_t i = 0; i < usage.size(); ++i)
usage[i].assign = true;
}
void CheckClass::clearAllVar(std::vector<Usage> &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<Function>::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<std::string> &callstack, const Scope *scope, std::vector<Usage> &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::simpleMatch(ftok->next(), "* 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->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<Function>::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<Function>::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% [ %any% ] ="))
{
assignVar(ftok->str(), scope, usage);
}
// Assignment of member of array item of member variable?
else if (Token::Match(ftok, "%var% [ %any% ] . %var% =") ||
Token::Match(ftok, "%var% [ %any% ] . %var% . %var% ="))
{
assignVar(ftok->str(), scope, usage);
}
// Assignment of array item of member variable?
else if (Token::Match(ftok, "%var% [ %any% ] [ %any% ] ="))
{
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 initialised 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<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (!scope->isClassOrStruct())
continue;
// dont 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<Function>::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<const Token *> 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<const Token *>::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::checkMemsetType(const Scope *start, const Token *tok, const Token *typeTok)
{
// Warn if type is a class or struct that contains any std::* variables
const Scope *scope = symbolDatabase->findVariableType(start, typeTok);
if (!scope)
return;
const Token *tstruct = scope->classDef;
const std::string &typeName = tstruct->str();
if (tstruct->tokAt(2)->str() == ":")
{
tstruct = tstruct->tokAt(3);
for (; tstruct; tstruct = tstruct->next())
{
while (Token::Match(tstruct, "public|private|protected|virtual"))
{
tstruct = tstruct->next();
}
// recursively check all parent classes
checkMemsetType(start, tok, tstruct);
tstruct = tstruct->next();
if (tstruct->str() != ",")
break;
}
}
for (; tstruct; tstruct = tstruct->next())
{
if (tstruct->str() == "}")
break;
// struct with function? skip function body..
if (Token::simpleMatch(tstruct, ") {"))
{
tstruct = tstruct->next()->link();
if (!tstruct)
break;
}
// before a statement there must be either:
// * private:|protected:|public:
// * { } ;
if (Token::Match(tstruct, "[;{}]") ||
tstruct->str().find(":") != std::string::npos)
{
if (Token::Match(tstruct->next(), "std :: %type% %var% ;"))
memsetError(tok, tok->str(), "'std::" + tstruct->strAt(3) + "'", typeName);
else if (Token::Match(tstruct->next(), "std :: %type% <"))
{
// backup the type
const std::string typestr(tstruct->strAt(3));
// check if it's a pointer variable..
unsigned int level = 0;
while (0 != (tstruct = tstruct->next()))
{
if (tstruct->str() == "<")
++level;
else if (tstruct->str() == ">")
{
if (level <= 1)
break;
--level;
}
else if (tstruct->str() == "(")
tstruct = tstruct->link();
}
if (!tstruct)
break;
// found error => report
if (Token::Match(tstruct, "> %var% ;"))
memsetError(tok, tok->str(), "'std::" + typestr + "'", typeName);
}
else if (Token::simpleMatch(tstruct->next(), "virtual"))
memsetError(tok, tok->str(), "virtual method", typeName);
}
}
}
void CheckClass::noMemset()
{
createSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
std::list<Function>::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;
checkMemsetType(&(*scope), tok, typeTok);
}
}
}
}
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<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
std::list<Function>::const_iterator func;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
if (func->type == Function::eOperatorEqual && func->access != Private)
{
if (func->token->strAt(-1) == "void")
operatorEqReturnError(func->token->tokAt(-1));
}
}
}
}
void CheckClass::operatorEqReturnError(const Token *tok)
{
reportError(tok, Severity::style, "operatorEq", "'operator=' should return something");
}
//---------------------------------------------------------------------------
// ClassCheck: "C& operator=(const C&) { ... return *this; }"
// operator= should return a reference to *this
//---------------------------------------------------------------------------
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<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->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::Match(tok->tokAt(1), "%type% :: operator= (") &&
tok->next()->str() == scope->className)))
operatorEqRetRefThisError(func->token);
}
}
if (!foundReturn)
operatorEqRetRefThisError(func->token);
}
void CheckClass::operatorEqRetRefThis()
{
if (!_settings->_checkCodingStyle)
return;
createSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (scope->isClassOrStruct())
{
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->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::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<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
std::list<Function>::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)
{
// check for proper function parameter signature
if ((Token::Match(func->tokenDef->next(), "( const %var% & )") ||
Token::Match(func->tokenDef->next(), "( const %var% & %var% )")) &&
func->tokenDef->strAt(3) == scope->className)
{
// find the parameter name
const Token *rhs = func->token;
while (rhs->str() != "&")
rhs = rhs->next();
rhs = rhs->next();
// find the ')'
const Token *tok = func->token->next()->link();
const Token *tok1 = tok;
if (tok1 && tok1->tokAt(1) && tok1->tokAt(1)->str() == "{" && tok1->tokAt(1)->link())
{
const Token *first = tok1->tokAt(1);
const Token *last = first->link();
if (!hasAssignSelf(first, last, rhs))
{
if (hasDeallocation(first, last))
operatorEqToSelfError(tok);
}
}
}
}
}
}
}
}
bool CheckClass::hasDeallocation(const Token *first, const Token *last)
{
// 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.
for (const Token *tok = first; 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 Token *first, const Token *last, const Token *rhs)
{
for (const Token *tok = first; 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
if (!_settings->inconclusive)
return;
createSymbolDatabase();
std::list<Scope>::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;
// 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<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope)
{
// only check classes and structures
if (!scope->isClassOrStruct())
continue;
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->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)
{
const Token *tok1 = tok;
while (tok->previous() && !Token::Match(tok->previous(), "}|{|;(||public:|protected:|private:|return|:|?"))
{
if (Token::simpleMatch(tok->previous(), "* this"))
return true;
tok = tok->previous();
}
if (tok->str() == "this")
return true;
if (Token::Match(tok, "( * %var% ) [") || (Token::Match(tok, "( * %var% ) <<") && tok1->next()->str() == "<<"))
tok = tok->tokAt(2);
// ignore class namespace
if (tok->str() == scope->className && tok->next()->str() == "::")
tok = tok->tokAt(2);
std::list<Variable>::const_iterator var;
for (var = scope->varlist.begin(); var != scope->varlist.end(); ++var)
{
if (var->name() == tok->str())
{
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;
}
bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok)
{
std::list<Function>::const_iterator func;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func)
{
if (func->tokenDef->str() == tok->str() && 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->str() == "=" ||
(tok1->str().find("=") == 1 &&
tok1->str().find_first_of("<!>") == std::string::npos))
{
if (tok1->previous()->varId() == 0 && !scope->derivedFrom.empty())
{
isconst = false;
break;
}
else if (isMemberVar(scope, tok1->previous()))
{
isconst = false;
break;
}
else if (tok1->previous()->str() == "]")
{
// TODO: I assume that the assigned variable is a member variable
// don't assume it
isconst = false;
break;
}
else if (tok1->next()->str() == "this")
{
isconst = false;
break;
}
// FIXME: I assume that a member union/struct variable is assigned.
else if (Token::Match(tok1->tokAt(-2), ". %var%"))
{
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, "++|--"))
{
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;
}
// 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<Function>::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<const Token *> 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?");
}