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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2012 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/>.
*/
//---------------------------------------------------------------------------
// Leaks when using auto variables
//---------------------------------------------------------------------------
#include "checkleakautovar.h"
#include "checkmemoryleak.h" // <- CheckMemoryLeak::memoryLeak
#include "checkother.h" // <- doubleFreeError
#include "tokenize.h"
#include "errorlogger.h"
#include "symboldatabase.h"
#include <fstream>
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
namespace {
CheckLeakAutoVar instance;
}
//---------------------------------------------------------------------------
void VarInfo::print()
{
std::cout << "size=" << alloctype.size() << std::endl;
std::map<unsigned int, std::string>::const_iterator it;
for (it = alloctype.begin(); it != alloctype.end(); ++it) {
std::string strusage;
std::map<unsigned int, std::string>::const_iterator use = possibleUsage.find(it->first);
if (use != possibleUsage.end())
strusage = use->second;
std::cout << "alloctype='" << it->second << "' "
<< "possibleUsage='" << strusage << "'" << std::endl;
}
}
void VarInfo::possibleUsageAll(const std::string &functionName)
{
possibleUsage.clear();
std::map<unsigned int, std::string>::const_iterator it;
for (it = alloctype.begin(); it != alloctype.end(); ++it)
possibleUsage[it->first] = functionName;
}
void CheckLeakAutoVar::leakError(const Token *tok, const std::string &varname)
{
const Standards standards;
CheckMemoryLeak checkmemleak(_tokenizer, _errorLogger, standards);
checkmemleak.memleakError(tok, varname);
//reportError(tok, Severity::error, "newleak", "New memory leak: " + varname);
}
void CheckLeakAutoVar::mismatchError(const Token *tok, const std::string &varname)
{
const Standards standards;
CheckMemoryLeak c(_tokenizer, _errorLogger, standards);
std::list<const Token *> callstack;
callstack.push_back(tok);
c.mismatchAllocDealloc(callstack, varname);
//reportError(tok, Severity::error, "newmismatch", "New mismatching allocation and deallocation: " + varname);
}
void CheckLeakAutoVar::deallocUseError(const Token *tok, const std::string &varname)
{
const Standards standards;
CheckMemoryLeak c(_tokenizer, _errorLogger, standards);
c.deallocuseError(tok, varname);
//reportError(tok, Severity::error, "newdeallocuse", "Using deallocated pointer " + varname);
}
void CheckLeakAutoVar::deallocReturnError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "deallocret", "Returning/dereferencing '" + varname + "' after it is deallocated / released");
}
void CheckLeakAutoVar::configurationInfo(const Token* tok, const std::string &functionName)
{
if (((!cfgalloc.empty() || !cfgdealloc.empty()) && _settings->isEnabled("style")) || _settings->experimental) {
reportError(tok,
Severity::information,
"leakconfiguration",
functionName + " configuration is needed to establish if there is a leak or not");
}
}
void CheckLeakAutoVar::parseConfigurationFile(const std::string &filename)
{
std::ifstream fin(filename.c_str());
if (!fin.is_open())
return;
std::string line;
while (std::getline(fin,line)) {
if (line.compare(0,4,"MEM ",0,4) == 0) {
std::string f1;
enum {ALLOC, DEALLOC} type = ALLOC;
std::string::size_type pos1 = line.find_first_not_of(" ", 4U);
while (pos1 < line.size()) {
const std::string::size_type pos2 = line.find(" ", pos1);
std::string f;
if (pos2 == std::string::npos)
f = line.substr(pos1);
else
f = line.substr(pos1, pos2-pos1);
if (f1.empty())
f1 = f;
if (f == ":")
type = DEALLOC;
else if (type == ALLOC)
cfgalloc[f] = f1;
else if (type == DEALLOC)
cfgdealloc[f] = f1;
pos1 = line.find_first_not_of(" ", pos2);
}
}
else if (line.compare(0,7,"IGNORE ",0,7) == 0) {
std::string::size_type pos1 = line.find_first_not_of(" ", 7U);
while (pos1 < line.size()) {
std::string::size_type pos2 = line.find_first_of(" ", pos1);
std::string functionName;
if (pos2 == std::string::npos)
functionName = line.substr(pos1);
else
functionName = line.substr(pos1, pos2-pos1);
cfgignore.insert(functionName);
pos1 = line.find_first_not_of(" ", pos2);
}
}
else if (line.compare(0,4,"USE ",0,4) == 0) {
std::string::size_type pos1 = line.find_first_not_of(" ", 4U);
while (pos1 < line.size()) {
std::string::size_type pos2 = line.find_first_of(" ", pos1);
std::string functionName;
if (pos2 == std::string::npos)
functionName = line.substr(pos1);
else
functionName = line.substr(pos1, pos2-pos1);
cfguse.insert(functionName);
pos1 = line.find_first_not_of(" ", pos2);
}
}
else if (line.compare(0,9,"NORETURN ",0,9) == 0) {
std::string::size_type pos1 = line.find_first_not_of(" ", 9U);
while (pos1 < line.size()) {
std::string::size_type pos2 = line.find_first_of(" ", pos1);
std::string functionName;
if (pos2 == std::string::npos)
functionName = line.substr(pos1);
else
functionName = line.substr(pos1, pos2-pos1);
cfgnoreturn.insert(functionName);
pos1 = line.find_first_not_of(" ", pos2);
}
}
}
}
void CheckLeakAutoVar::check()
{
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
// Check function scopes
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type == Scope::eFunction) {
// Empty variable info
VarInfo varInfo;
// Local variables that are known to be non-zero.
const std::set<unsigned int> notzero;
checkScope(i->classStart, &varInfo, notzero);
varInfo.conditionalAlloc.clear();
// Clear reference arguments from varInfo..
std::map<unsigned int, std::string>::iterator it = varInfo.alloctype.begin();
while (it != varInfo.alloctype.end()) {
const Variable *var = symbolDatabase->getVariableFromVarId(it->first);
if (!var ||
(var->isArgument() && var->isReference()) ||
(!var->isArgument() && !var->isLocal()))
varInfo.alloctype.erase(it++);
else
++it;
}
ret(i->classEnd, varInfo);
}
}
}
void CheckLeakAutoVar::checkScope(const Token * const startToken,
VarInfo *varInfo,
std::set<unsigned int> notzero)
{
std::map<unsigned int, std::string> &alloctype = varInfo->alloctype;
std::map<unsigned int, std::string> &possibleUsage = varInfo->possibleUsage;
const std::set<unsigned int> conditionalAlloc(varInfo->conditionalAlloc);
// Allocation functions. key = function name, value = allocation type
std::map<std::string, std::string> allocFunctions(cfgalloc);
allocFunctions["malloc"] = "malloc";
allocFunctions["strdup"] = "malloc";
allocFunctions["fopen"] = "fopen";
// Deallocation functions. key = function name, value = allocation type
std::map<std::string, std::string> deallocFunctions(cfgdealloc);
deallocFunctions["free"] = "malloc";
deallocFunctions["fclose"] = "fopen";
// Parse all tokens
const Token * const endToken = startToken->link();
for (const Token *tok = startToken; tok && tok != endToken; tok = tok->next()) {
// Deallocation and then dereferencing pointer..
if (tok->varId() > 0) {
const std::map<unsigned int, std::string>::iterator var = alloctype.find(tok->varId());
if (var != alloctype.end()) {
if (var->second == "dealloc" && !Token::Match(tok->previous(), "[;{},=] %var% =")) {
deallocUseError(tok, tok->str());
} else if (Token::simpleMatch(tok->tokAt(-2), "= &")) {
varInfo->erase(tok->varId());
} else if (Token::simpleMatch(tok->previous(), "=")) {
varInfo->erase(tok->varId());
}
}
}
if (tok->str() == "(" && tok->previous()->isName()) {
functionCall(tok->previous(), varInfo, "");
tok = tok->link();
continue;
}
// look for end of statement
if (!Token::Match(tok, "[;{}]") || Token::Match(tok->next(), "[;{}]"))
continue;
tok = tok->next();
if (tok == endToken)
break;
// parse statement
// assignment..
if (tok && tok->varId() && Token::Match(tok, "%var% =")) {
// taking address of another variable..
if (Token::Match(tok->next(), "= %var% [+;]")) {
if (tok->tokAt(2)->varId() != tok->varId()) {
// If variable points at allocated memory => error
leakIfAllocated(tok, *varInfo);
// no multivariable checking currently => bail out for rhs variables
for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
if (tok2->str() == ";") {
break;
}
if (tok2->varId()) {
varInfo->erase(tok2->varId());
}
}
}
}
// is variable used in rhs?
bool used_in_rhs = false;
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
if (tok2->str() == ";") {
break;
}
if (tok->varId() == tok2->varId()) {
used_in_rhs = true;
break;
}
}
// TODO: Better checking how the pointer is used in rhs?
if (used_in_rhs)
continue;
// Variable has already been allocated => error
if (conditionalAlloc.find(tok->varId()) == conditionalAlloc.end())
leakIfAllocated(tok, *varInfo);
varInfo->erase(tok->varId());
// not a local variable nor argument?
const Variable *var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(tok->varId());
if (var && !var->isArgument() && !var->isLocal()) {
continue;
}
// Don't check reference variables
if (var && var->isReference())
continue;
// allocation?
if (Token::Match(tok->tokAt(2), "%type% (")) {
const std::map<std::string, std::string>::const_iterator it = allocFunctions.find(tok->strAt(2));
if (it != allocFunctions.end()) {
alloctype[tok->varId()] = it->second;
}
}
// Assigning non-zero value variable. It might be used to
// track the execution for a later if condition.
if (Token::Match(tok->tokAt(2), "%num% ;") && MathLib::toLongNumber(tok->strAt(2)) != 0)
notzero.insert(tok->varId());
else if (Token::Match(tok->tokAt(2), "- %type% ;") && tok->tokAt(3)->isUpperCaseName())
notzero.insert(tok->varId());
else
notzero.erase(tok->varId());
}
// if/else
else if (Token::simpleMatch(tok, "if (")) {
// Parse function calls inside the condition
for (const Token *innerTok = tok->tokAt(2); innerTok; innerTok = innerTok->next()) {
if (innerTok->str() == ")")
break;
if (innerTok->str() == "(" && innerTok->previous()->isName()) {
std::string dealloc;
{
const std::map<std::string, std::string>::iterator func = deallocFunctions.find(tok->str());
if (func != deallocFunctions.end()) {
dealloc = func->second;
}
}
functionCall(innerTok->previous(), varInfo, dealloc);
innerTok = innerTok->link();
}
}
const Token *tok2 = tok->linkAt(1);
if (Token::simpleMatch(tok2, ") {")) {
VarInfo varInfo1(*varInfo);
VarInfo varInfo2(*varInfo);
if (Token::Match(tok->next(), "( %var% )")) {
varInfo2.erase(tok->tokAt(2)->varId());
if (notzero.find(tok->tokAt(2)->varId()) != notzero.end())
varInfo2.clear();
} else if (Token::Match(tok->next(), "( ! %var% )|&&")) {
varInfo1.erase(tok->tokAt(3)->varId());
} else if (Token::Match(tok->next(), "( %var% ( ! %var% ) )|&&")) {
varInfo1.erase(tok->tokAt(5)->varId());
}
checkScope(tok2->next(), &varInfo1, notzero);
tok2 = tok2->linkAt(1);
if (Token::simpleMatch(tok2, "} else {")) {
checkScope(tok2->tokAt(2), &varInfo2, notzero);
tok = tok2->linkAt(2)->previous();
} else {
tok = tok2->previous();
}
VarInfo old;
old.swap(*varInfo);
// Conditional allocation in varInfo1
std::map<unsigned int, std::string>::const_iterator it;
for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
if (varInfo2.alloctype.find(it->first) == varInfo2.alloctype.end() &&
old.alloctype.find(it->first) == old.alloctype.end()) {
varInfo->conditionalAlloc.insert(it->first);
}
}
// Conditional allocation in varInfo2
for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
if (varInfo1.alloctype.find(it->first) == varInfo1.alloctype.end() &&
old.alloctype.find(it->first) == old.alloctype.end()) {
varInfo->conditionalAlloc.insert(it->first);
}
}
// Conditional allocation/deallocation
for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
if (it->second == "dealloc" && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
varInfo->conditionalAlloc.erase(it->first);
varInfo2.erase(it->first);
}
}
for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
if (it->second == "dealloc" && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
varInfo->conditionalAlloc.erase(it->first);
varInfo1.erase(it->first);
}
}
alloctype.insert(varInfo1.alloctype.begin(), varInfo1.alloctype.end());
alloctype.insert(varInfo2.alloctype.begin(), varInfo2.alloctype.end());
possibleUsage.insert(varInfo1.possibleUsage.begin(), varInfo1.possibleUsage.end());
possibleUsage.insert(varInfo2.possibleUsage.begin(), varInfo2.possibleUsage.end());
}
}
// unknown control..
else if (Token::Match(tok, "%type% (") && Token::simpleMatch(tok->linkAt(1), ") {")) {
varInfo->clear();
break;
}
// Function call..
else if (Token::Match(tok, "%type% (") && tok->str() != "return") {
std::string dealloc;
{
const std::map<std::string, std::string>::iterator func = deallocFunctions.find(tok->str());
if (func != deallocFunctions.end()) {
dealloc = func->second;
}
}
functionCall(tok, varInfo, dealloc);
tok = tok->next()->link();
// Handle scopes that might be noreturn
if (dealloc.empty() && Token::simpleMatch(tok, ") ; }")) {
const std::string &functionName(tok->link()->previous()->str());
bool unknown = false;
if (cfgignore.find(functionName) == cfgignore.end() &&
cfguse.find(functionName) == cfguse.end() &&
_tokenizer->IsScopeNoReturn(tok->tokAt(2), &unknown)) {
if (unknown) {
//const std::string &functionName(tok->link()->previous()->str());
varInfo->possibleUsageAll(functionName);
} else {
varInfo->clear();
}
}
}
continue;
}
// return
else if (tok->str() == "return" || tok->str() == "throw") {
ret(tok, *varInfo);
varInfo->clear();
}
}
}
void CheckLeakAutoVar::functionCall(const Token *tok, VarInfo *varInfo, const std::string &dealloc)
{
std::map<unsigned int, std::string> &alloctype = varInfo->alloctype;
std::map<unsigned int, std::string> &possibleUsage = varInfo->possibleUsage;
// Ignore function call?
const bool ignore = bool(cfgignore.find(tok->str()) != cfgignore.end());
//const bool use = bool(cfguse.find(tok->str()) != cfguse.end());
if (ignore)
return;
for (const Token *arg = tok->tokAt(2); arg; arg = arg->nextArgument()) {
if ((Token::Match(arg, "%var% [-,)]") && arg->varId() > 0) ||
(Token::Match(arg, "& %var%") && arg->next()->varId() > 0)) {
// goto variable
if (arg->str() == "&")
arg = arg->next();
// Is variable allocated?
const std::map<unsigned int,std::string>::iterator var = alloctype.find(arg->varId());
if (var != alloctype.end()) {
if (dealloc.empty()) {
// possible usage
possibleUsage[arg->varId()] = tok->str();
} else if (var->second == "dealloc") {
CheckOther checkOther(_tokenizer, _settings, _errorLogger);
checkOther.doubleFreeError(tok, arg->str());
} else if (var->second != dealloc) {
// mismatching allocation and deallocation
mismatchError(tok, arg->str());
varInfo->erase(arg->varId());
} else {
// deallocation
var->second = "dealloc";
}
} else if (!dealloc.empty()) {
alloctype[arg->varId()] = "dealloc";
}
} else if (Token::Match(arg, "%var% (")) {
functionCall(arg, varInfo, dealloc);
}
}
}
void CheckLeakAutoVar::leakIfAllocated(const Token *vartok,
const VarInfo &varInfo)
{
const std::map<unsigned int, std::string> &alloctype = varInfo.alloctype;
const std::map<unsigned int, std::string> &possibleUsage = varInfo.possibleUsage;
const std::map<unsigned int,std::string>::const_iterator var = alloctype.find(vartok->varId());
if (var != alloctype.end() && var->second != "dealloc") {
const std::map<unsigned int, std::string>::const_iterator use = possibleUsage.find(vartok->varId());
if (use == possibleUsage.end()) {
leakError(vartok, vartok->str());
} else {
configurationInfo(vartok, use->second);
}
}
}
void CheckLeakAutoVar::ret(const Token *tok, const VarInfo &varInfo)
{
const std::map<unsigned int, std::string> &alloctype = varInfo.alloctype;
const std::map<unsigned int, std::string> &possibleUsage = varInfo.possibleUsage;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::map<unsigned int, std::string>::const_iterator it = alloctype.begin(); it != alloctype.end(); ++it) {
// don't warn if variable is conditionally allocated
if (it->second != "dealloc" && varInfo.conditionalAlloc.find(it->first) != varInfo.conditionalAlloc.end())
continue;
const unsigned int varid = it->first;
const Variable *var = symbolDatabase->getVariableFromVarId(varid);
if (var) {
bool used = false;
for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
if (tok2->str() == ";")
break;
if (Token::Match(tok2, "return|(|, %varid% [);,]", varid)) {
used = true;
break;
}
if (Token::Match(tok2, "return|(|, & %varid% . %var% [);,]", varid)) {
used = true;
break;
}
}
// return deallocated pointer
if (used && it->second == "dealloc")
deallocReturnError(tok, var->name());
else if (!used && it->second != "dealloc") {
const std::map<unsigned int, std::string>::const_iterator use = possibleUsage.find(varid);
if (use == possibleUsage.end()) {
leakError(tok, var->name());
} else {
configurationInfo(tok, use->second);
}
}
}
}
}
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