/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2010 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/>.
*/
//---------------------------------------------------------------------------
// Buffer overrun..
//---------------------------------------------------------------------------
#include "checkbufferoverrun.h"
#include "tokenize.h"
#include "errorlogger.h"
#include "mathlib.h"
#include <algorithm>
#include <sstream>
#include <list>
#include <cstring>
#include <cctype>
#include <climits>
#include <cassert> // <- assert
#include <cstdlib> // <- strtoul
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
namespace
{
CheckBufferOverrun instance;
}
//---------------------------------------------------------------------------
void CheckBufferOverrun::arrayIndexOutOfBounds(const Token *tok, int size, int index)
{
if (!tok)
arrayIndexOutOfBounds(size, index);
else
{
_callStack.push_back(tok);
arrayIndexOutOfBounds(size, index);
_callStack.pop_back();
}
}
void CheckBufferOverrun::arrayIndexOutOfBounds(int size, int index)
{
Severity::e severity;
if (size <= 1 || _callStack.size() > 1)
{
severity = Severity::possibleError;
if (_settings->inconclusive == false)
return;
}
else
{
severity = Severity::error;
}
if (_callStack.size() == 1)
{
std::ostringstream oss;
oss << "Array '" << (*_callStack.begin())->str() << "[" << size << "]' index " << index << " out of bounds";
reportError(_callStack, severity, "arrayIndexOutOfBounds", oss.str().c_str());
}
else
reportError(_callStack, severity, "arrayIndexOutOfBounds", "Array index out of bounds");
}
void CheckBufferOverrun::arrayIndexOutOfBounds(const Token *tok, const ArrayInfo &arrayInfo, const std::vector<int> &index)
{
std::ostringstream oss;
oss << "Array '" << arrayInfo.varname;
for (unsigned int i = 0; i < arrayInfo.num.size(); ++i)
oss << "[" << arrayInfo.num[i] << "]";
oss << "' index ";
if (index.size() == 1)
oss << index[0];
else
{
oss << arrayInfo.varname;
for (unsigned int i = 0; i < index.size(); ++i)
oss << "[" << index[i] << "]";
}
oss << " out of bounds";
reportError(tok, Severity::error, "arrayIndexOutOfBounds", oss.str().c_str());
}
void CheckBufferOverrun::bufferOverrun(const Token *tok, const std::string &varnames)
{
Severity::e severity;
if (_callStack.size() > 0)
{
severity = Severity::possibleError;
if (_settings->inconclusive == false)
return;
}
else
{
severity = Severity::error;
}
std::string v = varnames;
while (v.find(" ") != std::string::npos)
v.erase(v.find(" "), 1);
std::string errmsg("Buffer access out-of-bounds");
if (!v.empty())
errmsg += ": " + v;
reportError(tok, severity, "bufferAccessOutOfBounds", errmsg);
}
void CheckBufferOverrun::dangerousStdCin(const Token *tok)
{
if (_settings && _settings->inconclusive == false)
return;
reportError(tok, Severity::possibleError, "dangerousStdCin", "Dangerous usage of std::cin, possible buffer overrun");
}
void CheckBufferOverrun::strncatUsage(const Token *tok)
{
if (_settings && !_settings->_checkCodingStyle)
return;
reportError(tok, Severity::style, "strncatUsage", "Dangerous usage of strncat. Tip: the 3rd parameter means maximum number of characters to append");
}
void CheckBufferOverrun::outOfBounds(const Token *tok, const std::string &what)
{
reportError(tok, Severity::error, "outOfBounds", what + " is out of bounds");
}
void CheckBufferOverrun::sizeArgumentAsChar(const Token *tok)
{
if (_settings && !_settings->_checkCodingStyle)
return;
reportError(tok, Severity::style, "sizeArgumentAsChar", "The size argument is given as a char constant");
}
void CheckBufferOverrun::terminateStrncpyError(const Token *tok)
{
reportError(tok, Severity::style, "terminateStrncpy", "After a strncpy() the buffer should be zero-terminated");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check array usage..
//---------------------------------------------------------------------------
/**
* @brief This is a helper class to be used with std::find_if
*/
class TokenStrEquals
{
public:
/**
* @param str Token::str() is compared against this.
*/
TokenStrEquals(const std::string &str)
: value(str)
{
}
/**
* Called automatically by std::find_if
* @param tok Token inside the list
*/
bool operator()(const Token *tok) const
{
return value == tok->str();
}
private:
TokenStrEquals& operator=(const TokenStrEquals&); // disallow assignments
const std::string value;
};
/**
* Parse for loop initialization statement. Look for a counter variable
* \param tok [in] first token inside the parentheses
* \param varid [out] varid of counter variable
* \param init_value [out] init value of counter variable
* \return success => pointer to the for loop condition. fail => 0
*/
static const Token *for_init(const Token *tok, unsigned int &varid, std::string &init_value)
{
if (Token::Match(tok, "%var% = %any% ;"))
{
if (tok->tokAt(2)->isNumber())
{
init_value = tok->strAt(2);
}
varid = tok->varId();
tok = tok->tokAt(4);
}
else if (Token::Match(tok, "%type% %var% = %any% ;"))
{
if (tok->tokAt(3)->isNumber())
{
init_value = tok->strAt(3);
}
varid = tok->next()->varId();
tok = tok->tokAt(5);
}
else if (Token::Match(tok, "%type% %type% %var% = %any% ;"))
{
if (tok->tokAt(4)->isNumber())
{
init_value = tok->strAt(4);
}
varid = tok->tokAt(2)->varId();
tok = tok->tokAt(6);
}
else
return 0;
return tok;
}
/** Parse for condition */
static bool for_condition(const Token * const tok2, unsigned int varid, std::string &min_value, std::string &max_value, std::string &strindex, bool &maxMinFlipped)
{
if (Token::Match(tok2, "%varid% < %num% ;", varid))
{
maxMinFlipped = false;
long value = MathLib::toLongNumber(tok2->strAt(2));
max_value = MathLib::toString<long>(value - 1);
}
else if (Token::Match(tok2, "%varid% <= %num% ;", varid))
{
maxMinFlipped = false;
max_value = tok2->strAt(2);
}
else if (Token::Match(tok2, " %num% < %varid% ;", varid))
{
maxMinFlipped = true;
long value = MathLib::toLongNumber(tok2->str());
max_value = min_value;
min_value = MathLib::toString<long>(value + 1);
}
else if (Token::Match(tok2, "%num% <= %varid% ;", varid))
{
maxMinFlipped = true;
max_value = min_value;
min_value = tok2->str();
}
else
{
return false;
}
strindex = tok2->isName() ? tok2->str() : tok2->strAt(2);
return true;
}
/**
* Parse the third sub-statement in for head
* \param tok first token
* \param varid variable id of counter
* \param min_value min value of counter
* \param max_value max value of counter
* \param maxMinFlipped counting from max to min
*/
static bool for3(const Token * const tok,
unsigned int varid,
std::string &min_value,
std::string &max_value,
const bool maxMinFlipped)
{
assert(tok != 0);
if (Token::Match(tok, "%varid% += %num% )", varid) ||
Token::Match(tok, "%varid% = %num% + %varid% )", varid))
{
if (!MathLib::isInt(tok->strAt(2)))
return false;
const int num = MathLib::toLongNumber(tok->strAt(2));
// We have for example code: "for(i=2;i<22;i+=6)
// We can calculate that max value for i is 20, not 21
// 21-2 = 19
// 19/6 = 3
// 6*3+2 = 20
long max = MathLib::toLongNumber(max_value);
long min = MathLib::toLongNumber(min_value);
max = ((max - min) / num) * num + min;
max_value = MathLib::toString<long>(max);
}
else if (Token::Match(tok, "%varid% = %varid% + %num% )", varid))
{
if (!MathLib::isInt(tok->strAt(4)))
return false;
const int num = MathLib::toLongNumber(tok->strAt(4));
long max = MathLib::toLongNumber(max_value);
long min = MathLib::toLongNumber(min_value);
max = ((max - min) / num) * num + min;
max_value = MathLib::toString<long>(max);
}
else if (Token::Match(tok, "%varid% -= %num% )", varid) ||
Token::Match(tok, "%varid% = %num% - %varid% )", varid))
{
if (!MathLib::isInt(tok->strAt(2)))
return false;
const int num = MathLib::toLongNumber(tok->strAt(2));
long max = MathLib::toLongNumber(max_value);
long min = MathLib::toLongNumber(min_value);
max = ((max - min) / num) * num + min;
max_value = MathLib::toString<long>(max);
}
else if (Token::Match(tok, "%varid% = %varid% - %num% )", varid))
{
if (!MathLib::isInt(tok->strAt(4)))
return false;
const int num = MathLib::toLongNumber(tok->strAt(4));
long max = MathLib::toLongNumber(max_value);
long min = MathLib::toLongNumber(min_value);
max = ((max - min) / num) * num + min;
max_value = MathLib::toString<long>(max);
}
else if (Token::Match(tok, "--| %varid% --| )", varid))
{
if (!maxMinFlipped && MathLib::toLongNumber(min_value) < MathLib::toLongNumber(max_value))
{
// Code relies on the fact that integer will overflow:
// for (unsigned int i = 3; i < 5; --i)
// Set min value in this case to zero.
max_value = min_value;
min_value = "0";
}
}
else if (! Token::Match(tok, "++| %varid% ++| )", varid))
{
return false;
}
return true;
}
/**
* Check is the counter variable increased elsewhere inside the loop or used
* for anything else except reading
* \param tok first token of for-body
* \param varid counter variable id
* \return bailout needed => true
*/
static bool for_bailout(const Token * const tok1, unsigned int varid)
{
for (const Token *loopTok = tok1; loopTok && loopTok != tok1->link(); loopTok = loopTok->next())
{
if (loopTok->varId() == varid)
{
// Counter variable used inside loop
if (Token::Match(loopTok->next(), "+=|-=|++|--|=") ||
Token::Match(loopTok->previous(), "++|--"))
{
return true;
}
}
}
return false;
}
void CheckBufferOverrun::parse_for_body(const Token *tok2, const ArrayInfo &arrayInfo, const std::string &strindex, bool condition_out_of_bounds, unsigned int counter_varid, const std::string &min_counter_value, const std::string &max_counter_value)
{
const std::string pattern((arrayInfo.varid ? std::string("%varid%") : arrayInfo.varname) + " [ " + strindex + " ]");
int indentlevel2 = 0;
for (; tok2; tok2 = tok2->next())
{
if (tok2->str() == ";" && indentlevel2 == 0)
break;
if (tok2->str() == "{")
++indentlevel2;
if (tok2->str() == "}")
{
--indentlevel2;
if (indentlevel2 <= 0)
break;
}
if (Token::Match(tok2, "if|switch"))
{
// Bailout
break;
}
if (condition_out_of_bounds && Token::Match(tok2, pattern.c_str(), arrayInfo.varid))
{
bufferOverrun(tok2, arrayInfo.varname);
break;
}
else if (arrayInfo.varid && counter_varid > 0 && !min_counter_value.empty() && !max_counter_value.empty())
{
int min_index = 0;
int max_index = 0;
if (Token::Match(tok2, "%varid% [ %var% +|-|*|/ %num% ]", arrayInfo.varid) &&
tok2->tokAt(2)->varId() == counter_varid)
{
const char action = tok2->strAt(3)[0];
const std::string &second(tok2->tokAt(4)->str());
//printf("min_index: %s %c %s\n", min_counter_value.c_str(), action, second.c_str());
//printf("max_index: %s %c %s\n", max_counter_value.c_str(), action, second.c_str());
min_index = std::atoi(MathLib::calculate(min_counter_value, second, action).c_str());
max_index = std::atoi(MathLib::calculate(max_counter_value, second, action).c_str());
}
else if (Token::Match(tok2, "%varid% [ %num% +|-|*|/ %var% ]", arrayInfo.varid) &&
tok2->tokAt(4)->varId() == counter_varid)
{
const char action = tok2->strAt(3)[0];
const std::string &first(tok2->tokAt(2)->str());
//printf("min_index: %s %c %s\n", first.c_str(), action, min_counter_value.c_str());
//printf("max_index: %s %c %s\n", first.c_str(), action, max_counter_value.c_str());
min_index = std::atoi(MathLib::calculate(first, min_counter_value, action).c_str());
max_index = std::atoi(MathLib::calculate(first, max_counter_value, action).c_str());
}
//printf("min_index = %d, max_index = %d, size = %d\n", min_index, max_index, size);
if (min_index < 0 || max_index < 0)
{
arrayIndexOutOfBounds(tok2, (int)arrayInfo.num[0], std::min(min_index, max_index));
}
if (min_index >= (int)arrayInfo.num[0] || max_index >= (int)arrayInfo.num[0])
{
arrayIndexOutOfBounds(tok2, (int)arrayInfo.num[0], std::max(min_index, max_index));
}
}
}
}
void CheckBufferOverrun::checkFunctionCall(const Token &tok, unsigned int par, const ArrayInfo &arrayInfo)
{
std::map<std::string, unsigned int> total_size;
total_size["fgets"] = 2; // The second argument for fgets can't exceed the total size of the array
total_size["memcmp"] = 3;
total_size["memcpy"] = 3;
total_size["memmove"] = 3;
if (par == 1)
{
// reading from array
// if it is zero terminated properly there won't be buffer overruns
total_size["strncat"] = 3;
total_size["strncpy"] = 3;
total_size["memset"] = 3;
total_size["fread"] = 1001; // parameter 2 * parameter 3
total_size["fwrite"] = 1001; // parameter 2 * parameter 3
}
if (par == 2)
{
total_size["read"] = 3;
total_size["write"] = 3;
}
std::map<std::string, unsigned int>::const_iterator it = total_size.find(tok.str());
if (it != total_size.end())
{
unsigned int arg = it->second;
for (const Token *tok2 = tok.tokAt(2); tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
{
tok2 = tok2->link();
continue;
}
if (tok2->str() == ")")
break;
if (tok2->str() == ",")
{
--arg;
if (arg == 1)
{
if (Token::Match(tok2, ", %num% ,|)"))
{
const long sz = MathLib::toLongNumber(tok2->strAt(1));
unsigned int elements = 1;
for (unsigned int i = 0; i < arrayInfo.num.size(); ++i)
elements *= arrayInfo.num[i];
if (sz < 0 || sz > int(elements * arrayInfo.element_size))
{
bufferOverrun(&tok, arrayInfo.varname);
}
}
else if (Token::Match(tok2, ", %any% ,|)") && tok2->next()->str()[0] == '\'')
{
sizeArgumentAsChar(tok2->next());
}
break;
}
if (arg == 1000) // special code. This parameter multiplied with the next must not exceed total_size
{
if (Token::Match(tok2, ", %num% , %num% ,|)"))
{
const long sz = MathLib::toLongNumber(tok2->strAt(1)) * MathLib::toLongNumber(tok2->strAt(3));
unsigned int elements = 1;
for (unsigned int i = 0; i < arrayInfo.num.size(); ++i)
elements *= arrayInfo.num[i];
if (sz < 0 || sz > int(elements * arrayInfo.element_size))
{
bufferOverrun(&tok, arrayInfo.varname);
}
}
break;
}
}
}
}
}
void CheckBufferOverrun::checkScope(const Token *tok, const std::vector<std::string> &varname, const int size, const int total_size, unsigned int varid)
{
std::string varnames;
for (unsigned int i = 0; i < varname.size(); ++i)
varnames += (i == 0 ? "" : " . ") + varname[i];
const unsigned int varc(varname.empty() ? 0 : (varname.size() - 1) * 2);
if (Token::Match(tok, "return"))
{
tok = tok->next();
if (!tok)
return;
}
// Array index..
if (varid > 0)
{
if (Token::Match(tok, "%varid% [ %num% ]", varid))
{
int index = MathLib::toLongNumber(tok->strAt(2));
if (index >= size)
{
arrayIndexOutOfBounds(tok, size, index);
}
}
}
else if (Token::Match(tok, (varnames + " [ %num% ]").c_str()))
{
int index = MathLib::toLongNumber(tok->strAt(2 + varc));
if (index >= size)
{
arrayIndexOutOfBounds(tok->tokAt(varc), size, index);
}
}
int indentlevel = 0;
for (; tok; tok = tok->next())
{
if (tok->str() == "{")
{
++indentlevel;
}
else if (tok->str() == "}")
{
--indentlevel;
if (indentlevel < 0)
return;
}
if (varid != 0 && Token::Match(tok, "%varid% = new|malloc|realloc", varid))
{
// Abort
break;
}
// Array index..
if (varid > 0)
{
if (!tok->isName() && !Token::Match(tok, "[.&]") && Token::Match(tok->next(), "%varid% [ %num% ]", varid))
{
int index = MathLib::toLongNumber(tok->strAt(3));
if (index < 0 || index >= size)
{
if (index > size || !Token::Match(tok->previous(), "& ("))
{
arrayIndexOutOfBounds(tok->next(), size, index);
}
}
}
}
else if (!tok->isName() && !Token::Match(tok, "[.&]") && Token::Match(tok->next(), (varnames + " [ %num% ]").c_str()))
{
int index = MathLib::toLongNumber(tok->strAt(3 + varc));
if (index >= size)
{
arrayIndexOutOfBounds(tok->tokAt(1 + varc), size, index);
}
tok = tok->tokAt(4);
continue;
}
// memset, memcmp, memcpy, strncpy, fgets..
if (varid == 0)
{
ArrayInfo arrayInfo(0, varnames, 1, total_size);
if (Token::Match(tok, ("%var% ( " + varnames + " ,").c_str()))
checkFunctionCall(*tok, 1, arrayInfo);
if (Token::Match(tok, ("%var% ( %var% , " + varnames + " ,").c_str()))
checkFunctionCall(*tok, 2, arrayInfo);
}
// Loop..
if (Token::simpleMatch(tok, "for ("))
{
const Token *tok2 = tok->tokAt(2);
unsigned int counter_varid = 0;
std::string min_counter_value;
std::string max_counter_value;
tok2 = for_init(tok2, counter_varid, min_counter_value);
if (tok2 == 0 || counter_varid == 0)
continue;
bool maxMinFlipped = false;
std::string strindex;
if (!for_condition(tok2, counter_varid, min_counter_value, max_counter_value, strindex, maxMinFlipped))
continue;
// Get index variable and stopsize.
bool condition_out_of_bounds = true;
if (MathLib::toLongNumber(max_counter_value) < size)
condition_out_of_bounds = false;
if (!for3(tok2->tokAt(4), counter_varid, min_counter_value, max_counter_value, maxMinFlipped))
continue;
if (Token::Match(tok2->tokAt(4), "%var% =|+=|-=") && MathLib::toLongNumber(max_counter_value) <= size)
condition_out_of_bounds = false;
// Goto the end paranthesis of the for-statement: "for (x; y; z)" ..
tok2 = tok->next()->link();
if (!tok2 || !tok2->tokAt(5))
break;
// Check is the counter variable increased elsewhere inside the loop or used
// for anything else except reading
if (for_bailout(tok2->next(), counter_varid))
break;
ArrayInfo arrayInfo(varid, varnames, size, total_size);
parse_for_body(tok2->next(), arrayInfo, strindex, condition_out_of_bounds, counter_varid, min_counter_value, max_counter_value);
continue;
}
// Writing data into array..
if ((varid > 0 && Token::Match(tok, "strcpy|strcat ( %varid% , %str% )", varid)) ||
(varid == 0 && Token::Match(tok, ("strcpy|strcat ( " + varnames + " , %str% )").c_str())))
{
const long len = Token::getStrLength(tok->tokAt(varc + 4));
if (len < 0 || len >= total_size)
{
bufferOverrun(tok, varid > 0 ? "" : varnames.c_str());
continue;
}
}
// Detect few strcat() calls
if (varid > 0 && Token::Match(tok, "strcat ( %varid% , %str% ) ;", varid))
{
size_t charactersAppend = 0;
const Token *tok2 = tok;
while (tok2 && Token::Match(tok2, "strcat ( %varid% , %str% ) ;", varid))
{
charactersAppend += Token::getStrLength(tok2->tokAt(4));
if (charactersAppend >= static_cast<size_t>(total_size))
{
bufferOverrun(tok2);
break;
}
tok2 = tok2->tokAt(7);
}
}
// sprintf / snprintf..
if (varid > 0)
{
if (Token::Match(tok, "sprintf ( %varid% , %str% [,)]", varid))
{
checkSprintfCall(tok, total_size);
}
// snprintf..
if (Token::Match(tok, "snprintf ( %varid% , %num% ,", varid))
{
int n = MathLib::toLongNumber(tok->strAt(4));
if (n > total_size)
outOfBounds(tok->tokAt(4), "snprintf size");
}
}
// Function call..
// It's not interesting to check what happens when the whole struct is
// sent as the parameter, that is checked separately anyway.
if (Token::Match(tok, "%var% ("))
{
// Only perform this checking if showAll setting is enabled..
if (!_settings->inconclusive)
continue;
unsigned int parlevel = 0, par = 0;
const Token * tok1 = tok;
for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
{
++parlevel;
}
else if (tok2->str() == ")")
{
--parlevel;
if (parlevel < 1)
{
par = 0;
break;
}
}
else if (parlevel == 1 && (tok2->str() == ","))
{
++par;
}
if (parlevel == 1)
{
if (varid > 0 && Token::Match(tok2, "[(,] %varid% [,)]", varid))
{
++par;
tok1 = tok2->next();
break;
}
else if (varid == 0 && Token::Match(tok2, ("[(,] " + varnames + " [,)]").c_str()))
{
++par;
tok1 = tok2->tokAt(varc + 1);
break;
}
}
}
if (par == 0)
continue;
// Find function..
const Token *ftok = _tokenizer->getFunctionTokenByName(tok->str().c_str());
if (!ftok)
continue;
// Parse head of function..
ftok = ftok->tokAt(2);
parlevel = 1;
while (ftok && parlevel == 1 && par >= 1)
{
if (ftok->str() == "(")
++parlevel;
else if (ftok->str() == ")")
--parlevel;
else if (ftok->str() == ",")
--par;
else if (par == 1 && parlevel == 1 && Token::Match(ftok, "%var% [,)]"))
{
// Parameter name..
std::vector<std::string> parname;
parname.push_back(ftok->str());
const unsigned int parId = ftok->varId();
// Goto function body..
while (ftok && (ftok->str() != "{"))
ftok = ftok->next();
ftok = ftok ? ftok->next() : 0;
// Don't make recursive checking..
if (std::find_if(_callStack.begin(), _callStack.end(), TokenStrEquals(tok1->str())) != _callStack.end())
continue;
// Check variable usage in the function..
_callStack.push_back(tok1);
checkScope(ftok, parname, size, total_size, parId);
_callStack.pop_back();
// break out..
break;
}
ftok = ftok->next();
}
}
}
}
void CheckBufferOverrun::checkScope(const Token *tok, const ArrayInfo &arrayInfo)
{
const unsigned int total_size = arrayInfo.num[0] * arrayInfo.element_size;
unsigned int indentlevel = 0;
for (; tok; tok = tok->next())
{
if (tok->str() == "{")
{
++indentlevel;
}
else if (tok->str() == "}")
{
if (indentlevel == 0)
return;
--indentlevel;
}
else if (Token::Match(tok, "%varid% [ %num% ]", arrayInfo.varid))
{
std::vector<int> indexes;
for (const Token *tok2 = tok->next(); Token::Match(tok2, "[ %num% ]"); tok2 = tok2->tokAt(3))
{
const int index = MathLib::toLongNumber(tok2->strAt(1));
if (index < 0)
{
indexes.clear();
break;
}
indexes.push_back(index);
}
if (indexes.size() == arrayInfo.num.size())
{
// Check if the indexes point outside the whole array..
// char a[10][10];
// a[0][20] <-- ok.
// a[9][20] <-- error.
// total number of elements of array..
unsigned int totalElements = 1;
// total index..
unsigned int totalIndex = 0;
// calculate the totalElements and totalIndex..
for (unsigned int i = 0; i < indexes.size(); ++i)
{
unsigned int ri = indexes.size() - 1 - i;
totalIndex += indexes[ri] * totalElements;
totalElements *= arrayInfo.num[ri];
}
// just taking the address?
const bool addr(Token::Match(tok->previous(), "[.&]") ||
Token::simpleMatch(tok->tokAt(-2), "& ("));
// Is totalIndex in bounds?
if (totalIndex > totalElements || (!addr && totalIndex == totalElements))
{
arrayIndexOutOfBounds(tok, arrayInfo, indexes);
}
}
}
// cin..
else if (Token::Match(tok, "cin >> %varid% ;", arrayInfo.varid))
{
dangerousStdCin(tok);
}
// Loop..
else if (Token::simpleMatch(tok, "for ("))
{
const Token *tok2 = tok->tokAt(2);
unsigned int counter_varid = 0;
std::string min_counter_value;
std::string max_counter_value;
tok2 = for_init(tok2, counter_varid, min_counter_value);
if (tok2 == 0 || counter_varid == 0)
continue;
bool maxMinFlipped = false;
std::string strindex;
if (!for_condition(tok2, counter_varid, min_counter_value, max_counter_value, strindex, maxMinFlipped))
continue;
// Get index variable and stopsize.
bool condition_out_of_bounds = true;
if (MathLib::toLongNumber(max_counter_value) < (int)arrayInfo.num[0])
condition_out_of_bounds = false;
if (!for3(tok2->tokAt(4), counter_varid, min_counter_value, max_counter_value, maxMinFlipped))
continue;
if (Token::Match(tok2->tokAt(4), "%var% =|+=|-=") && MathLib::toLongNumber(max_counter_value) <= (int)arrayInfo.num[0])
condition_out_of_bounds = false;
// Goto the end paranthesis of the for-statement: "for (x; y; z)" ..
tok2 = tok->next()->link();
if (!tok2 || !tok2->tokAt(5))
break;
// Check is the counter variable increased elsewhere inside the loop or used
// for anything else except reading
if (for_bailout(tok2->next(), counter_varid))
break;
parse_for_body(tok2->next(), arrayInfo, strindex, condition_out_of_bounds, counter_varid, min_counter_value, max_counter_value);
continue;
}
// Check function call..
if (Token::Match(tok, "%var% ("))
{
// 1st parameter..
if (Token::Match(tok->tokAt(2), "%varid% ,", arrayInfo.varid))
checkFunctionCall(*tok, 1, arrayInfo);
else if (Token::Match(tok->tokAt(2), "%varid% + %num% ,", arrayInfo.varid))
{
const ArrayInfo ai(arrayInfo.limit(MathLib::toLongNumber(tok->strAt(4))));
checkFunctionCall(*tok, 1, ai);
}
// goto 2nd parameter and check it..
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
{
tok2 = tok2->link();
continue;
}
if (tok2->str() == ";" || tok2->str() == ")")
break;
if (tok2->str() == ",")
{
if (Token::Match(tok2, ", %varid% ,", arrayInfo.varid))
checkFunctionCall(*tok, 2, arrayInfo);
else if (Token::Match(tok2, ", %varid% + %num% ,", arrayInfo.varid))
{
const ArrayInfo ai(arrayInfo.limit(MathLib::toLongNumber(tok2->strAt(3))));
checkFunctionCall(*tok, 2, ai);
}
break;
}
}
}
if (_settings->_checkCodingStyle)
{
// check for strncpy which is not terminated
if ((Token::Match(tok, "strncpy ( %varid% , %var% , %num% )", arrayInfo.varid)))
{
// strncpy takes entire variable length as input size
if ((unsigned int)MathLib::toLongNumber(tok->strAt(6)) >= total_size)
{
const Token *tok2 = tok->next()->link()->next();
for (; tok2; tok2 = tok2->next())
{
if (tok2->varId() == tok->tokAt(2)->varId())
{
if (!Token::Match(tok2, "%varid% [ %any% ] = 0 ;", tok->tokAt(2)->varId()))
{
terminateStrncpyError(tok);
}
break;
}
}
}
}
}
// Dangerous usage of strncat..
if (Token::Match(tok, "strncpy|strncat ( %varid% , %any% , %num% )", arrayInfo.varid))
{
if (tok->str() == "strncat")
{
const unsigned int n = MathLib::toLongNumber(tok->strAt(6));
if (n >= total_size)
strncatUsage(tok);
}
// Dangerous usage of strncpy + strncat..
if (Token::Match(tok->tokAt(8), "; strncat ( %varid% , %any% , %num% )", arrayInfo.varid))
{
const unsigned int n = MathLib::toLongNumber(tok->strAt(6)) + MathLib::toLongNumber(tok->strAt(15));
if (n > total_size)
strncatUsage(tok->tokAt(9));
}
}
// Writing data into array..
if (Token::Match(tok, "strcpy|strcat ( %varid% , %str% )", arrayInfo.varid))
{
const unsigned long len = Token::getStrLength(tok->tokAt(4));
if (len >= total_size)
{
bufferOverrun(tok, arrayInfo.varname);
continue;
}
}
// Detect few strcat() calls
if (Token::Match(tok, "strcat ( %varid% , %str% ) ;", arrayInfo.varid))
{
size_t charactersAppend = 0;
const Token *tok2 = tok;
while (tok2 && Token::Match(tok2, "strcat ( %varid% , %str% ) ;", arrayInfo.varid))
{
charactersAppend += Token::getStrLength(tok2->tokAt(4));
if (charactersAppend >= static_cast<size_t>(total_size))
{
bufferOverrun(tok2, arrayInfo.varname);
break;
}
tok2 = tok2->tokAt(7);
}
}
if (Token::Match(tok, "sprintf ( %varid% , %str% [,)]", arrayInfo.varid))
{
checkSprintfCall(tok, total_size);
}
// snprintf..
if (Token::Match(tok, "snprintf ( %varid% , %num% ,", arrayInfo.varid))
{
const unsigned int n = MathLib::toLongNumber(tok->strAt(4));
if (n > total_size)
outOfBounds(tok->tokAt(4), "snprintf size");
}
}
}
//---------------------------------------------------------------------------
// Checking local variables in a scope
//---------------------------------------------------------------------------
void CheckBufferOverrun::checkGlobalAndLocalVariable()
{
int indentlevel = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->str() == "{")
++indentlevel;
else if (tok->str() == "}")
--indentlevel;
int size = 0;
std::string type;
unsigned int varid = 0;
int nextTok = 0;
// if the previous token exists, it must be either a variable name or "[;{}]"
if (tok->previous() && (!tok->previous()->isName() && !Token::Match(tok->previous(), "[;{}]")))
continue;
ArrayInfo arrayInfo;
if (arrayInfo.declare(tok, *_tokenizer))
{
while (tok && tok->str() != ";")
tok = tok->next();
if (!tok)
break;
checkScope(tok, arrayInfo);
continue;
}
if (Token::Match(tok, "%type% *| %var% [ %var% ] [;=]"))
{
unsigned int varpos = 1;
if (tok->next()->str() == "*")
++varpos;
// make sure the variable is defined
if (tok->tokAt(varpos + 2)->varId() == 0)
continue; // FIXME we loose the check for negative index when we bail
// get maximum size from type
// find where this token is defined
const Token *index_type = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->tokAt(varpos + 2)->varId());
index_type = index_type->previous();
if (index_type->str() == "char")
{
if (index_type->isUnsigned())
size = UCHAR_MAX + 1;
else if (index_type->isSigned())
size = SCHAR_MAX + 1;
else
size = CHAR_MAX + 1;
}
else if (index_type->str() == "short")
{
if (index_type->isUnsigned())
size = USHRT_MAX + 1;
else
size = SHRT_MAX + 1;
}
// checkScope assumes size is signed int so we limit the following sizes to INT_MAX
else if (index_type->str() == "int")
{
if (index_type->isUnsigned())
size = INT_MAX; // should be UINT_MAX + 1U;
else
size = INT_MAX; // should be INT_MAX + 1U;
}
else if (index_type->str() == "long")
{
if (index_type->isUnsigned())
{
if (index_type->isLong())
size = INT_MAX; // should be ULLONG_MAX + 1ULL;
else
size = INT_MAX; // should be ULONG_MAX + 1UL;
}
else
{
if (index_type->isLong())
size = INT_MAX; // should be LLONG_MAX + 1LL;
else
size = INT_MAX; // should be LONG_MAX + 1L;
}
}
type = tok->strAt(varpos - 1);
varid = tok->tokAt(varpos)->varId();
nextTok = varpos + 5;
}
else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = new %type% [ %num% ]"))
{
size = MathLib::toLongNumber(tok->strAt(6));
type = tok->strAt(4);
varid = tok->tokAt(1)->varId();
nextTok = 8;
}
else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = new %type% ( %num% )"))
{
size = 1;
type = tok->strAt(4);
varid = tok->tokAt(1)->varId();
nextTok = 8;
}
else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = malloc ( %num% ) ;"))
{
size = MathLib::toLongNumber(tok->strAt(5));
type = "char"; // minimum type, typesize=1
varid = tok->tokAt(1)->varId();
nextTok = 7;
if (varid > 0)
{
// get type of variable
const Token *declTok = Token::findmatch(_tokenizer->tokens(), "[;{}] %type% * %varid% ;", varid);
if (!declTok)
continue;
type = declTok->next()->str();
// malloc() gets count of bytes and not count of
// elements, so we should calculate count of elements
// manually
unsigned int sizeOfType = _tokenizer->sizeOfType(declTok->next());
if (sizeOfType > 0)
size /= sizeOfType;
}
}
else
{
continue;
}
if (varid == 0)
continue;
Token sizeTok(0);
sizeTok.str(type);
int total_size = size * _tokenizer->sizeOfType(&sizeTok);
if (total_size == 0)
continue;
// The callstack is empty
_callStack.clear();
std::vector<std::string> v;
checkScope(tok->tokAt(nextTok), v, size, total_size, varid);
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Checking member variables of structs..
//---------------------------------------------------------------------------
void CheckBufferOverrun::checkStructVariable()
{
const char declstruct[] = "struct|class %var% {";
for (const Token *tok = Token::findmatch(_tokenizer->tokens(), declstruct);
tok; tok = Token::findmatch(tok->next(), declstruct))
{
const std::string &structname = tok->next()->str();
// Found a struct declaration. Search for arrays..
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
{
// skip inner scopes..
if (tok2->next() && tok2->next()->str() == "{")
{
tok2 = tok2->next()->link();
continue;
}
if (tok2->str() == "}")
break;
ArrayInfo arrayInfo;
if (!arrayInfo.declare(tok2->next(), *_tokenizer))
continue;
// Only handling 1-dimensional arrays yet..
if (arrayInfo.num.size() > 1)
continue;
std::vector<std::string> varname;
varname.push_back("");
varname.push_back(arrayInfo.varname);
// Class member variable => Check functions
if (tok->str() == "class")
{
std::string func_pattern(structname + " :: %var% (");
const Token *tok3 = Token::findmatch(_tokenizer->tokens(), func_pattern.c_str());
while (tok3)
{
for (const Token *tok4 = tok3; tok4; tok4 = tok4->next())
{
if (Token::Match(tok4, "[;{}]"))
break;
if (Token::simpleMatch(tok4, ") {"))
{
std::vector<std::string> v;
checkScope(tok4->tokAt(2), v, arrayInfo.num[0], arrayInfo.num[0] * arrayInfo.element_size, arrayInfo.varid);
break;
}
}
tok3 = Token::findmatch(tok3->next(), func_pattern.c_str());
}
}
for (const Token *tok3 = _tokenizer->tokens(); tok3; tok3 = tok3->next())
{
if (tok3->str() != structname)
continue;
// Declare variable: Fred fred1;
if (Token::Match(tok3->next(), "%var% ;"))
varname[0] = tok3->strAt(1);
// Declare pointer: Fred *fred1
else if (Token::Match(tok3->next(), "* %var% [,);=]"))
varname[0] = tok3->strAt(2);
else
continue;
// Goto end of statement.
const Token *CheckTok = NULL;
while (tok3)
{
// End of statement.
if (tok3->str() == ";")
{
CheckTok = tok3;
break;
}
// End of function declaration..
if (Token::simpleMatch(tok3, ") ;"))
break;
// Function implementation..
if (Token::simpleMatch(tok3, ") {"))
{
CheckTok = tok3->tokAt(2);
break;
}
tok3 = tok3->next();
}
if (!tok3)
break;
if (!CheckTok)
continue;
// Check variable usage..
checkScope(CheckTok, varname, arrayInfo.num[0], arrayInfo.num[0] * arrayInfo.element_size, 0);
}
}
}
}
//---------------------------------------------------------------------------
void CheckBufferOverrun::bufferOverrun()
{
checkGlobalAndLocalVariable();
checkStructVariable();
}
//---------------------------------------------------------------------------
int CheckBufferOverrun::countSprintfLength(const std::string &input_string, const std::list<const Token*> ¶meters)
{
bool percentCharFound = false;
int input_string_size = 1;
bool handleNextParameter = false;
std::string digits_string = "";
bool i_d_x_f_found = false;
std::list<const Token*>::const_iterator paramIter = parameters.begin();
unsigned int parameterLength = 0;
for (std::string::size_type i = 0; i < input_string.length(); ++i)
{
if (input_string[i] == '\\')
{
if (input_string[i+1] == '0')
break;
++input_string_size;
++i;
continue;
}
if (percentCharFound)
{
switch (input_string[i])
{
case 'f':
case 'x':
case 'X':
case 'i':
i_d_x_f_found = true;
case 'c':
case 'e':
case 'E':
case 'g':
case 'o':
case 'u':
case 'p':
case 'n':
handleNextParameter = true;
break;
case 'd':
i_d_x_f_found = true;
if (paramIter != parameters.end() && *paramIter && (*paramIter)->str()[0] != '"')
parameterLength = (*paramIter)->str().length();
handleNextParameter = true;
break;
case 's':
if (paramIter != parameters.end() && *paramIter && (*paramIter)->str()[0] == '"')
parameterLength = Token::getStrLength(*paramIter);
handleNextParameter = true;
break;
}
}
if (input_string[i] == '%')
percentCharFound = !percentCharFound;
else if (percentCharFound)
{
digits_string.append(1, input_string[i]);
}
if (!percentCharFound)
input_string_size++;
if (handleNextParameter)
{
unsigned int tempDigits = std::abs(std::atoi(digits_string.c_str()));
if (i_d_x_f_found)
tempDigits = std::max(static_cast<int>(tempDigits), 1);
if (digits_string.find('.') != std::string::npos)
{
const std::string endStr = digits_string.substr(digits_string.find('.') + 1);
unsigned int maxLen = std::max(std::abs(std::atoi(endStr.c_str())), 1);
if (input_string[i] == 's')
{
// For strings, the length after the dot "%.2s" will limit
// the length of the string.
if (parameterLength > maxLen)
parameterLength = maxLen;
}
else
{
// For integers, the length after the dot "%.2d" can
// increase required length
if (tempDigits < maxLen)
tempDigits = maxLen;
}
}
if (tempDigits < parameterLength)
input_string_size += parameterLength;
else
input_string_size += tempDigits;
parameterLength = 0;
digits_string = "";
i_d_x_f_found = false;
percentCharFound = false;
handleNextParameter = false;
if (paramIter != parameters.end())
++paramIter;
}
}
return input_string_size;
}
void CheckBufferOverrun::checkSprintfCall(const Token *tok, int size)
{
std::list<const Token*> parameters;
if (tok->tokAt(5)->str() == ",")
{
const Token *end = tok->next()->link();
for (const Token *tok2 = tok->tokAt(5); tok2 && tok2 != end; tok2 = tok2->next())
{
if (Token::Match(tok2, ", %any% [,)]"))
{
if (Token::Match(tok2->next(), "%str%"))
parameters.push_back(tok2->next());
else if (Token::Match(tok2->next(), "%num%"))
parameters.push_back(tok2->next());
// TODO, get value of the variable if possible and use that instead of 0
else
parameters.push_back(0);
}
else
{
// Parameter is more complex, than just a value or variable. Ignore it for now
// and skip to next token.
parameters.push_back(0);
int ind = 0;
for (const Token *tok3 = tok2->next(); tok3; tok3 = tok3->next())
{
if (tok3->str() == "(")
++ind;
else if (tok3->str() == ")")
{
--ind;
if (ind < 0)
break;
}
else if (ind == 0 && tok3->str() == ",")
{
tok2 = tok3->previous();
break;
}
}
if (ind < 0)
break;
}
}
}
int len = countSprintfLength(tok->tokAt(4)->strValue(), parameters);
if (len > size)
{
bufferOverrun(tok);
}
}
void CheckBufferOverrun::negativeIndexError(const Token *tok, long index)
{
std::ostringstream ostr;
ostr << "Array index " << index << " is out of bounds";
reportError(tok, Severity::error, "negativeIndex", ostr.str());
}
void CheckBufferOverrun::negativeIndex()
{
const char pattern[] = "[ %num% ]";
for (const Token *tok = Token::findmatch(_tokenizer->tokens(), pattern); tok; tok = Token::findmatch(tok->next(),pattern))
{
const long index = MathLib::toLongNumber(tok->next()->str());
if (index < 0)
{
// Multidimensional index => error
if (Token::simpleMatch(tok->previous(), "]") || Token::simpleMatch(tok->tokAt(3), "["))
negativeIndexError(tok, index);
// 1-dimensional array => error
else if (tok->previous() && tok->previous()->varId())
{
const Token *tok2 = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->previous()->varId());
if (tok2 && Token::Match(tok2->next(), "[ %any% ] ;"))
negativeIndexError(tok, index);
}
}
}
}
#include "executionpath.h"
/// @addtogroup Checks
/// @{
CheckBufferOverrun::ArrayInfo::ArrayInfo()
: num(_num), element_size(_element_size), varid(_varid), varname(_varname)
{
_element_size = 0;
_varid = 0;
}
CheckBufferOverrun::ArrayInfo::ArrayInfo(const CheckBufferOverrun::ArrayInfo &ai)
: num(_num), element_size(_element_size), varid(_varid), varname(_varname)
{
*this = ai;
}
const CheckBufferOverrun::ArrayInfo & CheckBufferOverrun::ArrayInfo::operator=(const CheckBufferOverrun::ArrayInfo &ai)
{
if (&ai != this)
{
_element_size = ai.element_size;
_num = ai.num;
_varid = ai.varid;
_varname = ai.varname;
}
return *this;
}
/**
* Create array info with specified data
* The intention is that this is only a temporary solution.. all
* checking should be based on ArrayInfo from the start and then
* this will not be needed as the declare can be used instead.
*/
CheckBufferOverrun::ArrayInfo::ArrayInfo(unsigned int id, const std::string &name, unsigned int size1, unsigned int n)
: num(_num), element_size(_element_size), varid(_varid), varname(_varname)
{
_element_size = size1;
_num.push_back(n);
_varid = id;
_varname = name;
}
CheckBufferOverrun::ArrayInfo CheckBufferOverrun::ArrayInfo::limit(long value) const
{
unsigned int n = 1;
for (unsigned int i = 0; i < num.size(); ++i)
n *= num[i];
return ArrayInfo(varid, varname, element_size, value > (int)n ? 0 : n - value);
}
bool CheckBufferOverrun::ArrayInfo::declare(const Token *tok, const Tokenizer &tokenizer)
{
_num.clear();
_element_size = 0;
_varname.clear();
if (!tok->isName())
return false;
int ivar = 0;
if (Token::Match(tok, "%type% *| %var% ["))
ivar = 1;
else if (Token::Match(tok, "%type% %type% *| %var% ["))
ivar = 2;
else
return false;
// Goto variable name token, get element size..
const Token *vartok = tok->tokAt(ivar);
if (vartok->str() == "*")
{
_element_size = tokenizer.sizeOfType(vartok);
vartok = vartok->next();
}
else
{
_element_size = tokenizer.sizeOfType(tok);
}
if (_element_size == 0)
return false;
_varname = vartok->str();
_varid = vartok->varId();
if (!varid)
return false;
const Token *atok = vartok->tokAt(2);
if (!Token::Match(atok, "%num% ] ;|=|["))
return false;
while (Token::Match(atok, "%num% ] ;|=|["))
{
_num.push_back(MathLib::toLongNumber(atok->str()));
atok = atok->next();
if (Token::simpleMatch(atok, "] ["))
atok = atok->tokAt(2);
}
return (!_num.empty() && Token::Match(atok, "] ;|="));
}
/**
* @brief %Check for buffer overruns (using ExecutionPath)
*/
class ExecutionPathBufferOverrun : public ExecutionPath
{
public:
/** Startup constructor */
ExecutionPathBufferOverrun(Check *c, const std::map<unsigned int, CheckBufferOverrun::ArrayInfo> &arrayinfo)
: ExecutionPath(c, 0), arrayInfo(arrayinfo)
{
}
private:
/** Copy this check */
ExecutionPath *copy()
{
return new ExecutionPathBufferOverrun(*this);
}
/** is other execution path equal? */
bool is_equal(const ExecutionPath *e) const
{
const ExecutionPathBufferOverrun *c = static_cast<const ExecutionPathBufferOverrun *>(e);
return (value == c->value);
}
/** @brief buffer information */
const std::map<unsigned int, CheckBufferOverrun::ArrayInfo> &arrayInfo;
/** no implementation => compiler error if used by accident */
void operator=(const ExecutionPathBufferOverrun &);
/** internal constructor for creating extra checks */
ExecutionPathBufferOverrun(Check *c, const std::map<unsigned int, CheckBufferOverrun::ArrayInfo> &arrayinfo, unsigned int varid_)
: ExecutionPath(c, varid_),
arrayInfo(arrayinfo)
{
// Pretend that variables are initialized to 0
// This checking is not about uninitialized variables
value = 0;
}
unsigned int value;
/** @brief Assign value to a variable */
static void assign_value(std::list<ExecutionPath *> &checks, unsigned int varid, const std::string &value)
{
if (varid == 0)
return;
std::list<ExecutionPath *>::const_iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
ExecutionPathBufferOverrun *c = dynamic_cast<ExecutionPathBufferOverrun *>(*it);
if (c && c->varId == varid)
c->value = MathLib::toLongNumber(value);
}
}
/** @brief Found array usage.. */
static void array_index(const Token *tok, std::list<ExecutionPath *> &checks, unsigned int varid1, unsigned int varid2)
{
if (checks.empty() || varid1 == 0 || varid2 == 0)
return;
// Locate array info corresponding to varid1
CheckBufferOverrun::ArrayInfo ai;
{
ExecutionPathBufferOverrun *c = dynamic_cast<ExecutionPathBufferOverrun *>(checks.front());
std::map<unsigned int, CheckBufferOverrun::ArrayInfo>::const_iterator it;
it = c->arrayInfo.find(varid1);
if (it == c->arrayInfo.end())
return;
ai = it->second;
}
// Check if varid2 variable has a value that is out-of-bounds
std::list<ExecutionPath *>::const_iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
ExecutionPathBufferOverrun *c = dynamic_cast<ExecutionPathBufferOverrun *>(*it);
if (c && c->varId == varid2 && c->value >= ai.num[0])
{
// variable value is out of bounds, report error
CheckBufferOverrun *checkBufferOverrun = dynamic_cast<CheckBufferOverrun *>(c->owner);
if (checkBufferOverrun)
{
std::vector<int> index;
index.push_back(c->value);
checkBufferOverrun->arrayIndexOutOfBounds(tok, ai, index);
break;
}
}
}
}
const Token *parse(const Token &tok, std::list<ExecutionPath *> &checks) const
{
if (Token::Match(tok.previous(), "[;{}]"))
{
// Declaring variable..
if (Token::Match(&tok, "%type% %var% ;") && tok.isStandardType())
{
checks.push_back(new ExecutionPathBufferOverrun(owner, arrayInfo, tok.next()->varId()));
return tok.tokAt(2);
}
// Assign variable..
if (Token::Match(&tok, "%var% = %num% ;"))
{
assign_value(checks, tok.varId(), tok.strAt(2));
return tok.tokAt(3);
}
}
// Assign variable (unknown value = 0)..
if (Token::Match(&tok, "%var% ="))
{
assign_value(checks, tok.varId(), "0");
return &tok;
}
// Array index..
if (Token::Match(&tok, "%var% [ %var% ]"))
{
array_index(&tok, checks, tok.varId(), tok.tokAt(2)->varId());
return tok.tokAt(3);
}
return &tok;
}
};
/// @}
void CheckBufferOverrun::executionPaths()
{
// Parse all tokens and extract array info..
std::map<unsigned int, ArrayInfo> arrayInfo;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "[;{}] %type%"))
{
ArrayInfo ai;
if (!ai.declare(tok->next(), *_tokenizer))
continue;
arrayInfo[ai.varid] = ai;
}
}
// Perform checking - check how the arrayInfo arrays are used
ExecutionPathBufferOverrun c(this, arrayInfo);
checkExecutionPaths(_tokenizer->tokens(), &c);
}