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cppcheck/lib/checkother.cpp

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/*
* 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/>.
*/
//---------------------------------------------------------------------------
#include "checkother.h"
#include "mathlib.h"
#include "tokenize.h"
#include "executionpath.h"
#include <algorithm>
#include <list>
#include <map>
#include <sstream>
#include <cstring>
#include <cctype>
#include <memory>
#include <cmath> // fabs()
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
namespace
{
CheckOther instance;
}
//---------------------------------------------------------------------------
void CheckOther::warningOldStylePointerCast()
{
if (!_settings->_checkCodingStyle ||
(_tokenizer->tokens() && _tokenizer->fileLine(_tokenizer->tokens()).find(".cpp") == std::string::npos))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Old style pointer casting..
if (!Token::Match(tok, "( const| %type% * ) %var%") &&
!Token::Match(tok, "( const| %type% * ) (| new"))
continue;
int addToIndex = 0;
if (tok->tokAt(1)->str() == "const")
addToIndex = 1;
if (tok->tokAt(4 + addToIndex)->str() == "const")
continue;
// Is "type" a class?
const std::string pattern("class " + tok->tokAt(1 + addToIndex)->str());
if (!Token::findmatch(_tokenizer->tokens(), pattern.c_str()))
continue;
cstyleCastError(tok);
}
}
//---------------------------------------------------------------------------
// Redundant code..
//---------------------------------------------------------------------------
void CheckOther::warningRedundantCode()
{
if (!_settings->_checkCodingStyle)
return;
// if (p) delete p
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (! Token::simpleMatch(tok, "if ("))
continue;
const Token *tok2 = tok->tokAt(2);
/*
* Possible if-constructions:
*
* if (var)
* if (this->var)
* if (Foo::var)
*
**/
std::string varname = concatNames(&tok2);
if (!Token::Match(tok2, "%var% ) {"))
continue;
tok2 = tok2->tokAt(3);
/*
* Possible constructions:
*
* - delete %var%
* - delete [] %var%
* - free ( %var )
* - kfree ( %var% )
*
* Where %var% may be:
* - just variable name (var)
* - class member (this->var)
* - static member (Class::var)
*
**/
bool funcHasBracket = false;
if (Token::Match(tok2, "free|kfree ("))
{
tok2 = tok2->tokAt(2);
funcHasBracket = true;
}
else if (tok2->str() == "delete")
{
tok2 = tok2->next();
if (Token::simpleMatch(tok2, "[ ]"))
{
tok2 = tok2->tokAt(2);
}
}
std::string varname2 = concatNames(&tok2);
if (Token::Match(tok2, "%var%") && varname == varname2)
tok2 = tok2->next();
else
continue;
if (funcHasBracket)
{
if (tok2->str() != ")")
{
continue;
}
else
{
tok2 = tok2->next();
}
}
/*
* Possible constructions:
*
* - if (%var%) { delete %var%; }
* - if (%var%) { delete %var%; %var% = 0; }
*
**/
if (Token::Match(tok2, "; } !!else"))
{
redundantIfDelete0Error(tok);
}
else if (Token::Match(tok2, "; %var%"))
{
tok2 = tok2->next();
std::string varname3 = concatNames(&tok2);
if (Token::Match(tok2, "%var% = 0 ; } !!else") && varname2 == varname3)
{
redundantIfDelete0Error(tok);
}
}
}
// Redundant condition
// if (haystack.find(needle) != haystack.end())
// haystack.remove(needle);
redundantCondition2();
}
//---------------------------------------------------------------------------
void CheckOther::redundantCondition2()
{
const char pattern[] = "if ( %var% . find ( %any% ) != %var% . end ( ) ) "
"{|{|"
" %var% . remove ( %any% ) ; "
"}|}|";
const Token *tok = Token::findmatch(_tokenizer->tokens(), pattern);
while (tok)
{
bool b(tok->tokAt(15)->str() == "{");
// Get tokens for the fields %var% and %any%
const Token *var1 = tok->tokAt(2);
const Token *any1 = tok->tokAt(6);
const Token *var2 = tok->tokAt(9);
const Token *var3 = tok->tokAt(b ? 16 : 15);
const Token *any2 = tok->tokAt(b ? 20 : 19);
// Check if all the "%var%" fields are the same and if all the "%any%" are the same..
if (var1->str() == var2->str() &&
var2->str() == var3->str() &&
any1->str() == any2->str())
{
redundantIfRemoveError(tok);
}
tok = Token::findmatch(tok->next(), pattern);
}
}
//---------------------------------------------------------------------------
// "if (strlen(s))" can be rewritten as "if (*s != '\0')"
//---------------------------------------------------------------------------
void CheckOther::checkEmptyStringTest()
{
if (!_settings->_checkCodingStyle)
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Non-empty string tests
if (Token::Match(tok, "if ( strlen ( %any% ) )"))
{
emptyStringTestError(tok, tok->strAt(4), false);
}
else if (Token::Match(tok, "strlen ( %any% ) !=|> 0"))
{
emptyStringTestError(tok, tok->strAt(2), false);
}
else if (Token::Match(tok, "0 < strlen ( %any% )"))
{
emptyStringTestError(tok, tok->strAt(4), false);
}
// Empty string tests
else if (Token::Match(tok, "! strlen ( %any% )"))
{
emptyStringTestError(tok, tok->strAt(3), true);
}
else if (Token::Match(tok, "strlen ( %any% ) == 0"))
{
emptyStringTestError(tok, tok->strAt(2), true);
}
}
}
//---------------------------------------------------------------------------
// fflush(stdin) <- fflush only applies to output streams in ANSI C
//---------------------------------------------------------------------------
void CheckOther::checkFflushOnInputStream()
{
const Token *tok = _tokenizer->tokens();
while (tok && ((tok = Token::findmatch(tok, "fflush ( stdin )")) != NULL))
{
fflushOnInputStreamError(tok, tok->strAt(2));
tok = tok->tokAt(4);
}
}
//---------------------------------------------------------------------------
// strtol(str, 0, radix) <- radix must be 0 or 2-36
//---------------------------------------------------------------------------
void CheckOther::invalidFunctionUsage()
{
// strtol and strtoul..
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if ((tok->str() != "strtol") && (tok->str() != "strtoul"))
continue;
// Locate the third parameter of the function call..
int parlevel = 0;
int param = 1;
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
++parlevel;
else if (tok2->str() == ")")
--parlevel;
else if (parlevel == 1 && tok2->str() == ",")
{
++param;
if (param == 3)
{
if (Token::Match(tok2, ", %num% )"))
{
int radix = MathLib::toLongNumber(tok2->next()->str());
if (!(radix == 0 || (radix >= 2 && radix <= 36)))
{
dangerousUsageStrtolError(tok2);
}
}
break;
}
}
}
}
// sprintf|snprintf overlapping data
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Get variable id of target buffer..
unsigned int varid = 0;
if (Token::Match(tok, "sprintf|snprintf ( %var% ,"))
varid = tok->tokAt(2)->varId();
else if (Token::Match(tok, "sprintf|snprintf ( %var% . %var% ,"))
varid = tok->tokAt(4)->varId();
if (varid == 0)
continue;
// goto ","
const Token *tok2 = tok->tokAt(3);
while (tok2 && tok2->str() != ",")
tok2 = tok2->next();
// is any source buffer overlapping the target buffer?
int parlevel = 0;
while ((tok2 = tok2->next()) != NULL)
{
if (tok2->str() == "(")
++parlevel;
else if (tok2->str() == ")")
{
--parlevel;
if (parlevel < 0)
break;
}
else if (parlevel == 0 && Token::Match(tok2, ", %varid% [,)]", varid))
{
sprintfOverlappingDataError(tok2->next(), tok2->next()->str());
break;
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check for unsigned divisions
//---------------------------------------------------------------------------
void CheckOther::checkUnsignedDivision()
{
if (!_settings->_checkCodingStyle)
return;
// Check for "ivar / uvar" and "uvar / ivar"
std::map<unsigned int, char> varsign;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "[{};(,] %type% %var% [;=,)]"))
{
if (tok->tokAt(1)->isUnsigned())
varsign[tok->tokAt(2)->varId()] = 'u';
else
varsign[tok->tokAt(2)->varId()] = 's';
}
else if (!Token::Match(tok, "[).]") && Token::Match(tok->next(), "%var% / %num%"))
{
if (tok->strAt(3)[0] == '-')
{
char sign1 = varsign[tok->tokAt(1)->varId()];
if (sign1 == 'u')
{
udivError(tok->next());
}
}
}
else if (Token::Match(tok, "[([=*/+-,] %num% / %var%"))
{
if (tok->strAt(1)[0] == '-')
{
char sign2 = varsign[tok->tokAt(3)->varId()];
if (sign2 == 'u')
{
udivError(tok->next());
}
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Usage of function variables
//---------------------------------------------------------------------------
static bool isOp(const Token *tok)
{
return bool(tok &&
(tok->str() == "&&" ||
tok->str() == "||" ||
tok->str() == "==" ||
tok->str() == "!=" ||
tok->str() == "<" ||
tok->str() == "<=" ||
tok->str() == ">" ||
tok->str() == ">=" ||
tok->str() == "<<" ||
Token::Match(tok, "[+-*/%&!~|^,[])?:]")));
}
class Variables
{
public:
enum VariableType { standard, array, pointer, reference, pointerArray, referenceArray };
/** Store information about variable usage */
class VariableUsage
{
public:
VariableUsage(const Token *name = 0,
VariableType type = standard,
bool read = false,
bool write = false,
bool modified = false) :
_name(name),
_type(type),
_read(read),
_write(write),
_modified(modified),
_noAlias(false)
{
}
/** variable is used.. set both read+write */
void use()
{
_read = true;
_write = true;
}
/** is variable unused? */
bool unused() const
{
return (_read == false && _write == false);
}
const Token *_name;
VariableType _type;
bool _read;
bool _write;
bool _modified; // read/modify/write
bool _noAlias; // don't alias
std::set<unsigned int> _aliases;
};
typedef std::map<unsigned int, VariableUsage> VariableMap;
void clear()
{
_varUsage.clear();
}
VariableMap &varUsage()
{
return _varUsage;
}
void addVar(const Token *name, VariableType type, bool write_);
void read(unsigned int varid);
void readAliases(unsigned int varid);
void readAll(unsigned int varid);
void write(unsigned int varid);
void writeAliases(unsigned int varid);
void writeAll(unsigned int varid);
void use(unsigned int varid);
void modified(unsigned int varid);
VariableUsage *find(unsigned int varid);
void alias(unsigned int varid1, unsigned int varid2);
void erase(unsigned int varid)
{
_varUsage.erase(varid);
}
void eraseAliases(unsigned int varid);
void eraseAll(unsigned int varid);
// don't alias this variable because it's aliased to something undefined or unsupported
// or because it's aliased to something in a larger scope
void noAlias(unsigned int varid);
private:
VariableMap _varUsage;
};
void Variables::alias(unsigned int varid1, unsigned int varid2)
{
// alias to self
if (varid1 == varid2)
{
VariableUsage *var = find(varid1);
if (var)
{
var->_noAlias = false;
var->use();
}
return;
}
std::set<unsigned int>::iterator i;
VariableUsage *var1 = find(varid1);
// remove var1 from all aliases
for (i = var1->_aliases.begin(); i != var1->_aliases.end(); ++i)
{
VariableUsage *temp = find(*i);
if (temp)
temp->_aliases.erase(var1->_name->varId());
}
// remove all aliases from var1
var1->_aliases.clear();
var1->_noAlias = false;
VariableUsage *var2 = find(varid2);
// var1 gets all var2s aliases
for (i = var2->_aliases.begin(); i != var2->_aliases.end(); ++i)
{
if (*i != varid1)
var1->_aliases.insert(*i);
}
// var2 is an alias of var1
var2->_aliases.insert(varid1);
var1->_aliases.insert(varid2);
if (var2->_type == Variables::pointer)
var2->_read = true;
}
void Variables::eraseAliases(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
erase(*aliases);
}
}
void Variables::eraseAll(unsigned int varid)
{
eraseAliases(varid);
erase(varid);
}
void Variables::noAlias(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
usage->_noAlias = true;
}
void Variables::addVar(const Token *name,
VariableType type,
bool write_)
{
_varUsage.insert(std::make_pair(name->varId(), VariableUsage(name, type, false, write_, false)));
}
void Variables::read(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
usage->_read = true;
}
void Variables::readAliases(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
if (!usage->_noAlias)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_read = true;
}
}
}
}
void Variables::readAll(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
usage->_read = true;
if (!usage->_noAlias)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_read = true;
}
}
}
}
void Variables::write(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
usage->_write = true;
}
void Variables::writeAliases(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
if (!usage->_noAlias)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_write = true;
}
}
}
}
void Variables::writeAll(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
usage->_write = true;
if (!usage->_noAlias)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_write = true;
}
}
}
}
void Variables::use(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
usage->use();
if (!usage->_noAlias)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->use();
}
}
}
}
void Variables::modified(unsigned int varid)
{
VariableUsage *usage = find(varid);
if (usage)
{
usage->_modified = true;
if (!usage->_noAlias)
{
std::set<unsigned int>::iterator aliases;
for (aliases = usage->_aliases.begin(); aliases != usage->_aliases.end(); ++aliases)
{
VariableUsage *aliased = find(*aliases);
if (aliased)
aliased->_modified = true;
}
}
}
}
Variables::VariableUsage *Variables::find(unsigned int varid)
{
if (varid)
{
VariableMap::iterator i = _varUsage.find(varid);
if (i != _varUsage.end())
return &i->second;
}
return 0;
}
static int doAssignment(Variables &variables, const Token *tok, bool pointer, bool post, bool paren)
{
int next = 0;
// check for aliased variable
unsigned int varid1 = tok->varId();
Variables::VariableUsage *var1 = variables.find(varid1);
if (var1)
{
Variables::VariableUsage *var2 = 0;
int start = 2;
if (post)
start++;
if (paren)
start++;
if (Token::Match(tok->tokAt(start), "&| %var%") ||
Token::Match(tok->tokAt(start), "( const| struct|union| %type% *| ) &| %var%") ||
Token::Match(tok->tokAt(start), "( const| struct|union| %type% *| ) ( &| %var%") ||
Token::Match(tok->tokAt(start), "%any% < const| struct|union| %type% *| > ( &| %var%"))
{
unsigned int offset = 0;
unsigned int varid2;
bool addressOf = false;
// check for C style cast
if (tok->tokAt(start)->str() == "(")
{
if (tok->tokAt(start + 1)->str() == "const")
offset++;
if (Token::Match(tok->tokAt(start + 1 + offset), "struct|union"))
offset++;
if (tok->tokAt(start + 2 + offset)->str() == "*")
offset++;
if (tok->tokAt(start + 3 + offset)->str() == "&")
{
addressOf = true;
next = start + 4 + offset;
}
else if (tok->tokAt(start + 3 + offset)->str() == "(")
{
if (tok->tokAt(start + 4 + offset)->str() == "&")
{
addressOf = true;
next = start + 5 + offset;
}
else
next = start + 4 + offset;
}
else
next = start + 3 + offset;
}
// check for C++ style cast
else if (tok->tokAt(start)->str().find("cast") != std::string::npos &&
tok->tokAt(start + 1)->str() == "<")
{
if (tok->tokAt(start + 2)->str() == "const")
offset++;
if (Token::Match(tok->tokAt(start + 2 + offset), "struct|union"))
offset++;
if (tok->tokAt(start + 3 + offset)->str() == "*")
offset++;
if (tok->tokAt(start + 5 + offset)->str() == "&")
{
addressOf = true;
next = start + 6 + offset;
}
else
next = start + 5 + offset;
}
// no cast
else
{
if (tok->tokAt(start)->str() == "&")
{
addressOf = true;
next = start + 1;
}
else if (tok->tokAt(start)->str() == "new")
return 0;
else
next = start;
}
// check if variable is local
varid2 = tok->tokAt(next)->varId();
var2 = variables.find(varid2);
if (var1->_type != Variables::reference && !addressOf)
{
if (var2)
{
if (var1->_type == Variables::pointer)
{
if (!(var2->_type == Variables::array || var2->_type == Variables::pointer))
variables.read(varid2);
}
else
{
if (var2->_type == Variables::pointer && tok->tokAt(next +1)->str() == "[")
variables.readAliases(varid2);
variables.read(varid2);
}
}
}
if (var2) // local variable
{
if (var1->_type == Variables::pointer && !pointer)
{
if (addressOf ||
var2->_type == Variables::array ||
var2->_type == Variables::pointer)
{
variables.alias(varid1, varid2);
}
}
else if (var1->_type == Variables::reference)
{
variables.alias(varid1, varid2);
}
else
variables.read(varid2);
}
else // not a local variable (or an unsupported local variable)
{
if (var1->_type == Variables::pointer && !pointer)
{
// aliased variables in a larger scope are not supported
var1->_noAlias = true;
}
}
}
}
// check for alias to struct member
// char c[10]; a.b = c;
else if (Token::Match(tok->tokAt(-2), "%var% ."))
{
if (Token::Match(tok->tokAt(2), "%var%"))
{
unsigned int varid2 = tok->tokAt(2)->varId();
Variables::VariableUsage *var2 = variables.find(varid2);
// struct member aliased to local variable
if (var2 && (var2->_type == Variables::array ||
var2->_type == Variables::pointer))
{
// erase aliased variable and all variables that alias it
// to prevent false positives
variables.eraseAll(varid2);
}
}
}
return next;
}
void CheckOther::functionVariableUsage()
{
if (!_settings->_checkCodingStyle)
return;
// Parse all executing scopes..
for (const Token *token = Token::findmatch(_tokenizer->tokens(), ") const| {"); token;)
{
// goto "{"
while (token->str() != "{")
token = token->next();
// First token for the current scope..
const Token *const tok1 = token;
// Find next scope that will be checked next time..
token = Token::findmatch(token->link(), ") const| {");
// varId, usage {read, write, modified}
Variables variables;
unsigned int indentlevel = 0;
for (const Token *tok = tok1; tok; tok = tok->next())
{
if (tok->str() == "{")
++indentlevel;
else if (tok->str() == "}")
{
--indentlevel;
if (indentlevel == 0)
break;
}
else if (Token::Match(tok, "struct|union|class {") ||
Token::Match(tok, "struct|union|class %type% {|:"))
{
while (tok->str() != "{")
tok = tok->next();
tok = tok->link();
if (! tok)
break;
}
if (Token::Match(tok, "[;{}] asm ( ) ;"))
{
variables.clear();
break;
}
// standard type declaration with possible initialization
// int i; int j = 0;
if (Token::Match(tok, "[;{}] %type% %var% ;|=") &&
tok->next()->isStandardType())
{
variables.addVar(tok->tokAt(2), Variables::standard,
tok->tokAt(3)->str() == "=");
tok = tok->tokAt(2);
}
// standard type declaration and initialization using constructor
// int i(0);
else if (Token::Match(tok, "[;{}] %type% %var% ( %any% ) ;") &&
tok->next()->isStandardType())
{
variables.addVar(tok->tokAt(2), Variables::standard, true);
// check if a local variable is used to initialize this variable
if (tok->tokAt(4)->varId() > 0)
variables.readAll(tok->tokAt(4)->varId());
tok = tok->tokAt(5);
}
// standard type declaration of array of with possible initialization
// int i[10]; int j[2] = { 0, 1 };
else if (Token::Match(tok, "[;{}] %type% %var% [ %any% ] ;|=") &&
tok->next()->isStandardType())
{
variables.addVar(tok->tokAt(2), Variables::array,
tok->tokAt(6)->str() == "=");
// check for reading array size from local variable
if (tok->tokAt(4)->varId() != 0)
variables.read(tok->tokAt(4)->varId());
tok = tok->tokAt(5);
}
// pointer or reference declaration with possible initialization
// int * i; int * j = 0;
else if (Token::Match(tok, "[;{}] %type% *|& %var% ;|="))
{
if (tok->next()->str() != "return")
{
Variables::VariableType type;
if (tok->tokAt(2)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
bool written = tok->tokAt(4)->str() == "=";
variables.addVar(tok->tokAt(3), type, written);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(3), false, false, false);
tok = tok->tokAt(3 + offset);
}
}
// const pointer or reference declaration with possible initialization
// const int * i; const int * j = 0;
else if (Token::Match(tok, "[;{}] const %type% *|& %var% ;|="))
{
Variables::VariableType type;
if (tok->tokAt(3)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
bool written = tok->tokAt(5)->str() == "=";
variables.addVar(tok->tokAt(4), type, written);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(4), false, false, false);
tok = tok->tokAt(4 + offset);
}
// pointer or reference of struct or union declaration with possible initialization
// struct s * i; struct s * j = 0;
else if (Token::Match(tok, "[;{}] struct|union %type% *|& %var% ;|="))
{
Variables::VariableType type;
if (tok->tokAt(3)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
bool written = tok->tokAt(5)->str() == "=";
variables.addVar(tok->tokAt(4), type, written);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(4), false, false, false);
tok = tok->tokAt(4 + offset);
}
// const pointer or reference of struct or union declaration with possible initialization
// const struct s * i; const struct s * j = 0;
else if (Token::Match(tok, "[;{}] const struct|union %type% *|& %var% ;|="))
{
Variables::VariableType type;
if (tok->tokAt(4)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
bool written = tok->tokAt(6)->str() == "=";
variables.addVar(tok->tokAt(5), type, written);
int offset = 0;
// check for assignment
if (written)
offset = doAssignment(variables, tok->tokAt(5), false, false, false);
tok = tok->tokAt(5 + offset);
}
// pointer or reference declaration with initialization using constructor
// int * i(j); int * k(i);
else if (Token::Match(tok, "[;{}] %type% &|* %var% ( %any% ) ;") &&
(tok->next()->isStandardType() || tok->next()->str() == "void"))
{
Variables::VariableType type;
if (tok->tokAt(2)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
unsigned int varid = 0;
// check for aliased variable
if (Token::Match(tok->tokAt(5), "%var%"))
varid = tok->tokAt(5)->varId();
variables.addVar(tok->tokAt(3), type, true);
// check if a local variable is used to initialize this variable
if (varid > 0)
{
Variables::VariableUsage *var = variables.find(varid);
if (type == Variables::pointer)
{
variables.use(tok->tokAt(5)->varId());
if (var && (var->_type == Variables::array ||
var->_type == Variables::pointer))
var->_aliases.insert(tok->varId());
}
else
{
variables.readAll(tok->tokAt(5)->varId());
if (var)
var->_aliases.insert(tok->varId());
}
}
tok = tok->tokAt(6);
}
// const pointer or reference declaration with initialization using constructor
// const int * i(j); const int * k(i);
else if (Token::Match(tok, "[;{}] const %type% &|* %var% ( %any% ) ;") &&
(tok->tokAt(2)->isStandardType() || tok->tokAt(2)->str() == "void"))
{
Variables::VariableType type;
if (tok->tokAt(3)->str() == "*")
type = Variables::pointer;
else
type = Variables::reference;
unsigned int varid = 0;
// check for aliased variable
if (Token::Match(tok->tokAt(6), "%var%"))
varid = tok->tokAt(6)->varId();
variables.addVar(tok->tokAt(4), type, true);
// check if a local variable is used to initialize this variable
if (varid > 0)
{
Variables::VariableUsage *var = variables.find(varid);
if (type == Variables::pointer)
{
variables.use(tok->tokAt(6)->varId());
if (var && (var->_type == Variables::array ||
var->_type == Variables::pointer))
var->_aliases.insert(tok->varId());
}
else
{
variables.readAll(tok->tokAt(6)->varId());
if (var)
var->_aliases.insert(tok->varId());
}
}
tok = tok->tokAt(7);
}
// array of pointer or reference declaration with possible initialization
// int * p[10]; int * q[10] = { 0 };
else if (Token::Match(tok, "[;{}] %type% *|& %var% [ %any% ] ;|="))
{
if (tok->next()->str() != "return")
{
variables.addVar(tok->tokAt(3),
tok->tokAt(2)->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(7)->str() == "=");
// check for reading array size from local variable
if (tok->tokAt(5)->varId() != 0)
variables.read(tok->tokAt(5)->varId());
tok = tok->tokAt(6);
}
}
// const array of pointer or reference declaration with possible initialization
// const int * p[10]; const int * q[10] = { 0 };
else if (Token::Match(tok, "[;{}] const %type% *|& %var% [ %any% ] ;|="))
{
variables.addVar(tok->tokAt(4),
tok->tokAt(3)->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(8)->str() == "=");
// check for reading array size from local variable
if (tok->tokAt(6)->varId() != 0)
variables.read(tok->tokAt(6)->varId());
tok = tok->tokAt(7);
}
// array of pointer or reference of struct or union declaration with possible initialization
// struct S * p[10]; struct T * q[10] = { 0 };
else if (Token::Match(tok, "[;{}] struct|union %type% *|& %var% [ %any% ] ;|="))
{
variables.addVar(tok->tokAt(4),
tok->tokAt(3)->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(8)->str() == "=");
// check for reading array size from local variable
if (tok->tokAt(6)->varId() != 0)
variables.read(tok->tokAt(6)->varId());
tok = tok->tokAt(7);
}
// const array of pointer or reference of struct or union declaration with possible initialization
// const struct S * p[10]; const struct T * q[10] = { 0 };
else if (Token::Match(tok, "[;{}] const struct|union %type% *|& %var% [ %any% ] ;|="))
{
variables.addVar(tok->tokAt(5),
tok->tokAt(4)->str() == "*" ? Variables::pointerArray : Variables::referenceArray,
tok->tokAt(9)->str() == "=");
// check for reading array size from local variable
if (tok->tokAt(7)->varId() != 0)
variables.read(tok->tokAt(7)->varId());
tok = tok->tokAt(8);
}
else if (Token::Match(tok, "delete|return|throw %var%"))
variables.readAll(tok->next()->varId());
// assignment
else if (Token::Match(tok, "*| (| ++|--| %var% ++|--| )| ="))
{
bool pointer = false;
bool pre = false;
bool post = false;
bool paren = false;
if (tok->str() == "*")
{
pointer = true;
tok = tok->next();
}
if (tok->str() == "(")
{
paren = true;
tok = tok->next();
}
if (Token::Match(tok, "++|--"))
{
pre = true;
tok = tok->next();
}
if (Token::Match(tok->next(), "++|--"))
{
post = true;
}
unsigned int varid1 = tok->varId();
const Token *start = tok;
tok = tok->tokAt(doAssignment(variables, tok, pointer, post, paren));
if (pre || post)
variables.use(varid1);
if (pointer)
{
variables.writeAliases(varid1);
variables.read(varid1);
}
else
{
Variables::VariableUsage *var = variables.find(varid1);
if (var && var->_type == Variables::reference)
{
variables.writeAliases(varid1);
variables.read(varid1);
}
else
variables.write(varid1);
}
// checked for chained assignments
if (tok != start && tok->next()->str() == "=")
{
Variables::VariableUsage *var = variables.find(tok->varId());
if (var && var->_type != Variables::reference)
var->_read = true;
tok = tok->previous();
}
}
// assignment
else if (Token::Match(tok, "%var% [") && Token::Match(tok->next()->link(), "] ="))
{
unsigned int varid = tok->varId();
Variables::VariableUsage *var = variables.find(varid);
if (var)
{
if (var->_type == Variables::pointer)
{
variables.read(varid);
variables.writeAliases(varid);
}
else
variables.writeAll(varid);
}
}
else if (Token::Match(tok, ">>|& %var%"))
variables.use(tok->next()->varId()); // use = read + write
// function parameter
else if (Token::Match(tok, "[(,] %var% ["))
variables.use(tok->next()->varId()); // use = read + write
// function parameter
else if (Token::Match(tok, "[(,] %var% [,)]") && tok->previous()->str() != "*")
variables.use(tok->next()->varId()); // use = read + write
else if (Token::Match(tok, " %var% ."))
variables.use(tok->varId()); // use = read + write
else if ((Token::Match(tok, "[(=&!]") || isOp(tok)) &&
(Token::Match(tok->next(), "%var%") && !Token::Match(tok->next(), "true|false|new")))
variables.readAll(tok->next()->varId());
else if (Token::Match(tok, "-=|+=|*=|/=|&=|^= %var%") || Token::Match(tok, "|= %var%"))
variables.modified(tok->next()->varId());
else if (Token::Match(tok, "%var%") && (tok->next()->str() == ")" || isOp(tok->next())))
variables.readAll(tok->varId());
else if (Token::Match(tok, "; %var% ;"))
variables.readAll(tok->next()->varId());
else if (Token::Match(tok, "++|-- %var%"))
variables.modified(tok->next()->varId());
else if (Token::Match(tok, "%var% ++|--"))
variables.modified(tok->varId());
}
// Check usage of all variables in the current scope..
Variables::VariableMap::const_iterator it;
for (it = variables.varUsage().begin(); it != variables.varUsage().end(); ++it)
{
const Variables::VariableUsage &usage = it->second;
const std::string &varname = usage._name->str();
if (usage.unused() && !usage._modified)
unusedVariableError(usage._name, varname);
else if (usage._modified & !usage._write)
unassignedVariableError(usage._name, varname);
else if (!usage._read && !usage._modified)
unreadVariableError(usage._name, varname);
else if (!usage._write)
unassignedVariableError(usage._name, varname);
}
}
}
void CheckOther::unusedVariableError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::style, "unusedVariable", "Unused variable: " + varname);
}
void CheckOther::unreadVariableError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::style, "unreadVariable", "Variable '" + varname + "' is assigned a value that is never used");
}
void CheckOther::unassignedVariableError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::style, "unassignedVariable", "Variable '" + varname + "' is not assigned a value");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check scope of variables..
//---------------------------------------------------------------------------
void CheckOther::checkVariableScope()
{
if (!_settings->_checkCodingStyle)
return;
// Walk through all tokens..
bool func = false;
int indentlevel = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Skip class and struct declarations..
if ((tok->str() == "class") || (tok->str() == "struct"))
{
for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
{
if (tok2->str() == "{")
{
tok = tok2->link();
break;
}
if (Token::Match(tok2, "[,);]"))
{
break;
}
}
if (! tok)
break;
}
else if (tok->str() == "{")
{
++indentlevel;
}
else if (tok->str() == "}")
{
--indentlevel;
if (indentlevel == 0)
func = false;
}
if (indentlevel == 0 && Token::simpleMatch(tok, ") {"))
{
func = true;
}
if (indentlevel > 0 && func && Token::Match(tok, "[{};]"))
{
// First token of statement..
const Token *tok1 = tok->next();
if (! tok1)
continue;
if ((tok1->str() == "return") ||
(tok1->str() == "throw") ||
(tok1->str() == "delete") ||
(tok1->str() == "goto") ||
(tok1->str() == "else"))
continue;
// Variable declaration?
if (Token::Match(tok1, "%type% %var% ; %var% = %num% ;"))
{
// Tokenizer modify "int i = 0;" to "int i; i = 0;",
// so to handle this situation we just skip
// initialization (see ticket #272).
const unsigned int firstVarId = tok1->next()->varId();
const unsigned int secondVarId = tok1->tokAt(3)->varId();
if (firstVarId > 0 && firstVarId == secondVarId)
{
lookupVar(tok1->tokAt(6), tok1->strAt(1));
}
}
else if (tok1->isStandardType() && Token::Match(tok1, "%type% %var% [;=]"))
{
lookupVar(tok1, tok1->strAt(1));
}
}
}
}
//---------------------------------------------------------------------------
void CheckOther::lookupVar(const Token *tok1, const std::string &varname)
{
const Token *tok = tok1;
// Skip the variable declaration..
while (tok && tok->str() != ";")
tok = tok->next();
// Check if the variable is used in this indentlevel..
bool used1 = false; // used in one sub-scope -> reducable
bool used2 = false; // used in more sub-scopes -> not reducable
int indentlevel = 0;
int parlevel = 0;
bool for_or_while = false; // is sub-scope a "for/while/etc". anything that is not "if"
while (tok)
{
if (tok->str() == "{")
{
++indentlevel;
}
else if (tok->str() == "}")
{
if (indentlevel == 0)
break;
--indentlevel;
if (indentlevel == 0)
{
if (for_or_while && used2)
return;
used2 |= used1;
used1 = false;
}
}
else if (tok->str() == "(")
{
++parlevel;
}
else if (tok->str() == ")")
{
--parlevel;
}
// Bail out if references are used
else if (Token::simpleMatch(tok, (std::string("& ") + varname).c_str()))
{
return;
}
else if (tok->str() == varname)
{
if (indentlevel == 0)
return;
used1 = true;
if (for_or_while && !Token::simpleMatch(tok->next(), "="))
used2 = true;
if (used1 && used2)
return;
}
else if (indentlevel == 0)
{
// %unknown% ( %any% ) {
// If %unknown% is anything except if, we assume
// that it is a for or while loop or a macro hiding either one
if (Token::simpleMatch(tok->next(), "(") &&
Token::simpleMatch(tok->next()->link(), ") {"))
{
if (tok->str() != "if")
for_or_while = true;
}
if (Token::simpleMatch(tok, "do {"))
for_or_while = true;
if (parlevel == 0 && (tok->str() == ";"))
for_or_while = false;
}
tok = tok->next();
}
// Warning if this variable:
// * not used in this indentlevel
// * used in lower indentlevel
if (used1 || used2)
variableScopeError(tok1, varname);
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check for constant function parameters
//---------------------------------------------------------------------------
void CheckOther::checkConstantFunctionParameter()
{
if (!_settings->_checkCodingStyle)
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "[,(] const std :: %type% %var% [,)]"))
{
passedByValueError(tok, tok->strAt(5));
}
else if (Token::Match(tok, "[,(] const std :: %type% < %type% > %var% [,)]"))
{
passedByValueError(tok, tok->strAt(8));
}
else if (Token::Match(tok, "[,(] const std :: %type% < std :: %type% > %var% [,)]"))
{
passedByValueError(tok, tok->strAt(10));
}
else if (Token::Match(tok, "[,(] const std :: %type% < std :: %type% , std :: %type% > %var% [,)]"))
{
passedByValueError(tok, tok->strAt(14));
}
else if (Token::Match(tok, "[,(] const std :: %type% < %type% , std :: %type% > %var% [,)]"))
{
passedByValueError(tok, tok->strAt(12));
}
else if (Token::Match(tok, "[,(] const std :: %type% < std :: %type% , %type% > %var% [,)]"))
{
passedByValueError(tok, tok->strAt(12));
}
else if (Token::Match(tok, "[,(] const std :: %type% < %type% , %type% > %var% [,)]"))
{
passedByValueError(tok, tok->strAt(10));
}
else if (Token::Match(tok, "[,(] const %type% %var% [,)]"))
{
// Check if type is a struct or class.
const std::string pattern(std::string("class|struct ") + tok->strAt(2));
if (Token::findmatch(_tokenizer->tokens(), pattern.c_str()))
{
passedByValueError(tok, tok->strAt(3));
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check that all struct members are used
//---------------------------------------------------------------------------
void CheckOther::checkStructMemberUsage()
{
if (!_settings->_checkCodingStyle)
return;
std::string structname;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->fileIndex() != 0)
continue;
if (Token::Match(tok, "struct|union %type% {"))
{
structname.clear();
if (Token::simpleMatch(tok->previous(), "extern"))
continue;
if ((!tok->previous() || Token::simpleMatch(tok->previous(), ";")) && Token::Match(tok->tokAt(2)->link(), ("} ; " + tok->strAt(1) + " %var% ;").c_str()))
continue;
structname = tok->strAt(1);
// Bail out if struct/union contain any functions
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
{
structname = "";
break;
}
if (tok2->str() == "}")
break;
}
// Bail out if some data is casted to struct..
const std::string s("( struct| " + tok->next()->str() + " * ) & %var% [");
if (Token::findmatch(tok, s.c_str()))
structname = "";
// Try to prevent false positives when struct members are not used directly.
if (Token::findmatch(tok, (structname + " *").c_str()))
structname = "";
else if (Token::findmatch(tok, (structname + " %type% *").c_str()))
structname = "";
}
if (tok->str() == "}")
structname = "";
if (!structname.empty() && Token::Match(tok, "[{;]"))
{
// Declaring struct variable..
std::string varname;
if (Token::Match(tok->next(), "%type% %var% [;[]"))
varname = tok->strAt(2);
else if (Token::Match(tok->next(), "%type% %type% %var% [;[]"))
varname = tok->strAt(3);
else if (Token::Match(tok->next(), "%type% * %var% [;[]"))
varname = tok->strAt(3);
else if (Token::Match(tok->next(), "%type% %type% * %var% [;[]"))
varname = tok->strAt(4);
else
continue;
// Check if the struct variable is anywhere in the file
const std::string usagePattern(". " + varname);
bool used = false;
for (const Token *tok2 = _tokenizer->tokens(); tok2; tok2 = tok2->next())
{
if (Token::simpleMatch(tok2, usagePattern.c_str()))
{
used = true;
break;
}
}
if (! used)
{
unusedStructMemberError(tok->next(), structname, varname);
}
}
}
}
//---------------------------------------------------------------------------
// Check usage of char variables..
//---------------------------------------------------------------------------
void CheckOther::checkCharVariable()
{
if (!_settings->_checkCodingStyle)
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Declaring the variable..
if (Token::Match(tok, "[{};(,] char %var% [;=,)]"))
{
// Check for unsigned char
if (tok->tokAt(1)->isUnsigned())
continue;
// Set tok to point to the variable name
tok = tok->tokAt(2);
if (tok->str() == "char")
tok = tok->next();
// Check usage of char variable..
int indentlevel = 0;
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next())
{
if (tok2->str() == "{")
++indentlevel;
else if (tok2->str() == "}")
{
--indentlevel;
if (indentlevel <= 0)
break;
}
else if (tok2->str() == "return")
continue;
std::string temp = "%var% [ " + tok->str() + " ]";
if ((tok2->str() != ".") && Token::Match(tok2->next(), temp.c_str()))
{
charArrayIndexError(tok2->next());
break;
}
if (Token::Match(tok2, "[;{}] %var% = %any% [&|] %any% ;"))
{
// is the char variable used in the calculation?
if (tok2->tokAt(3)->varId() != tok->varId() && tok2->tokAt(5)->varId() != tok->varId())
continue;
// it's ok with a bitwise and where the other operand is 0xff or less..
if (std::string(tok2->strAt(4)) == "&")
{
if (tok2->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok2->strAt(3)))
continue;
if (tok2->tokAt(5)->isNumber() && MathLib::isGreater("0x100", tok2->strAt(5)))
continue;
}
// is the result stored in a short|int|long?
if (!Token::findmatch(_tokenizer->tokens(), "short|int|long %varid%", tok2->next()->varId()))
continue;
// This is an error..
charBitOpError(tok2);
break;
}
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Incomplete statement..
//---------------------------------------------------------------------------
void CheckOther::checkIncompleteStatement()
{
if (!_settings->_checkCodingStyle)
return;
int parlevel = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->str() == "(")
++parlevel;
else if (tok->str() == ")")
--parlevel;
if (parlevel != 0)
continue;
if (Token::simpleMatch(tok, "= {"))
{
/* We are in an assignment, so it's not a statement.
* Skip until ";" */
while (tok->str() != ";")
{
int level = 0;
do
{
if (tok->str() == "(" || tok->str() == "{")
++level;
else if (tok->str() == ")" || tok->str() == "}")
--level;
tok = tok->next();
if (tok == NULL)
return;
}
while (level > 0);
}
continue;
}
if (Token::Match(tok, "[;{}] %str%") && !Token::Match(tok->tokAt(2), "[,}]"))
{
constStatementError(tok->next(), "string");
}
if (Token::Match(tok, "[;{}] %num%") && !Token::Match(tok->tokAt(2), "[,}]"))
{
constStatementError(tok->next(), "numeric");
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// str plus char
//---------------------------------------------------------------------------
void CheckOther::strPlusChar()
{
bool charVars[10000] = {0};
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Declaring char variable..
if (Token::Match(tok, "char|int|short %var% [;=]"))
{
unsigned int varid = tok->next()->varId();
if (varid > 0 && varid < 10000)
charVars[varid] = true;
}
//
else if (Token::Match(tok, "[=(] %str% + %any%"))
{
// char constant..
const std::string s = tok->strAt(3);
if (s[0] == '\'')
strPlusChar(tok->next());
// char variable..
unsigned int varid = tok->tokAt(3)->varId();
if (varid > 0 && varid < 10000 && charVars[varid])
strPlusChar(tok->next());
}
}
}
void CheckOther::nullPointerAfterLoop()
{
// Locate insufficient null-pointer handling after loop
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (! Token::Match(tok, "while ( %var% )"))
continue;
const unsigned int varid(tok->tokAt(2)->varId());
if (varid == 0)
continue;
const std::string varname(tok->strAt(2));
// Locate the end of the while loop..
const Token *tok2 = tok->tokAt(4);
if (tok2->str() == "{")
tok2 = tok2->link();
else
{
while (tok2 && tok2->str() != ";")
tok2 = tok2->next();
}
// Goto next token
if (tok2)
tok2 = tok2->next();
// Check if the variable is dereferenced..
while (tok2)
{
if (tok2->str() == "{" || tok2->str() == "}" || tok2->str() == "break")
break;
if (tok2->varId() == varid)
{
if (tok2->next()->str() == "." || Token::Match(tok2->next(), "= %varid% .", varid))
{
// Is this variable a pointer?
const Token *tok3 = Token::findmatch(_tokenizer->tokens(), "%type% * %varid% [;)=]", varid);
if (!tok3)
break;
if (!tok3->previous() ||
Token::Match(tok3->previous(), "[({};]") ||
tok3->previous()->isName())
{
nullPointerError(tok2, varname);
}
}
break;
}
tok2 = tok2->next();
}
}
}
void CheckOther::nullPointerLinkedList()
{
// looping through items in a linked list in a inner loop..
for (const Token *tok1 = _tokenizer->tokens(); tok1; tok1 = tok1->next())
{
// search for a "for" token..
if (!Token::simpleMatch(tok1, "for ("))
continue;
if (!Token::simpleMatch(tok1->next()->link(), ") {"))
continue;
// is there any dereferencing occuring in the for statement..
unsigned int parlevel2 = 1;
for (const Token *tok2 = tok1->tokAt(2); tok2; tok2 = tok2->next())
{
// Parantheses..
if (tok2->str() == "(")
++parlevel2;
else if (tok2->str() == ")")
{
if (parlevel2 <= 1)
break;
--parlevel2;
}
// Dereferencing a variable inside the "for" parantheses..
else if (Token::Match(tok2, "%var% . %var%"))
{
const unsigned int varid(tok2->varId());
if (varid == 0)
continue;
if (Token::Match(tok2->tokAt(-2), "%varid% ?", varid))
continue;
const std::string varname(tok2->str());
// Check usage of dereferenced variable in the loop..
unsigned int indentlevel3 = 0;
for (const Token *tok3 = tok1->next()->link(); tok3; tok3 = tok3->next())
{
if (tok3->str() == "{")
++indentlevel3;
else if (tok3->str() == "}")
{
if (indentlevel3 <= 1)
break;
--indentlevel3;
}
else if (Token::Match(tok3, "while ( %varid% &&|)", varid))
{
// Make sure there is a "break" to prevent segmentation faults..
unsigned int indentlevel4 = indentlevel3;
for (const Token *tok4 = tok3->next()->link(); tok4; tok4 = tok4->next())
{
if (tok4->str() == "{")
++indentlevel4;
else if (tok4->str() == "}")
{
if (indentlevel4 <= 1)
{
// Is this variable a pointer?
const Token *tempTok = Token::findmatch(_tokenizer->tokens(), "%type% * %varid% [;)=]", varid);
if (tempTok)
nullPointerError(tok1, varname, tok3->linenr());
break;
}
--indentlevel4;
}
else if (tok4->str() == "break")
break;
}
}
}
}
}
}
}
void CheckOther::nullPointerStructByDeRefAndChec()
{
// Dereferencing a struct pointer and then checking if it's NULL..
for (const Token *tok1 = _tokenizer->tokens(); tok1; tok1 = tok1->next())
{
if (Token::Match(tok1, "[{};] %var% = %var% . %var%"))
{
if (std::string(tok1->strAt(1)) == tok1->strAt(3))
continue;
tok1 = tok1->tokAt(3);
const unsigned int varid1(tok1->varId());
if (varid1 == 0)
continue;
const std::string varname(tok1->str());
// Checking if the struct pointer is non-null before the assignment..
{
const Token *tok2 = _tokenizer->tokens();
while (tok2)
{
if (tok2 == tok1)
break;
if (Token::Match(tok2, "if|while ( !| %varid% )", varid1))
break;
tok2 = tok2->next();
}
if (tok2 != tok1)
continue;
}
unsigned int indentlevel2 = 0;
for (const Token *tok2 = tok1->tokAt(3); tok2; tok2 = tok2->next())
{
if (tok2->str() == "{")
++indentlevel2;
else if (tok2->str() == "}")
{
if (indentlevel2 == 0)
break;
--indentlevel2;
}
// goto destination..
else if (tok2->isName() && Token::simpleMatch(tok2->next(), ":"))
break;
// Reassignment of the struct
else if (tok2->varId() == varid1)
{
if (tok2->next()->str() == "=")
break;
if (Token::Match(tok2->tokAt(-2), "[,(] &"))
break;
}
// Loop..
/** @todo don't bail out if the variable is not used in the loop */
else if (tok2->str() == "do")
break;
// return at base level => stop checking
else if (indentlevel2 == 0 && tok2->str() == "return")
break;
else if (Token::Match(tok2, "if ( !| %varid% )", varid1))
{
// Is this variable a pointer?
const Token *tempTok = Token::findmatch(_tokenizer->tokens(), "%type% * %varid% [;)=]", varid1);
if (tempTok)
nullPointerError(tok1, varname, tok2->linenr());
break;
}
}
}
}
}
void CheckOther::nullPointerByDeRefAndChec()
{
// Dereferencing a pointer and then checking if it's NULL..
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->str() == "if" && Token::Match(tok->previous(), "; if ( ! %var% )"))
{
const unsigned int varid(tok->tokAt(3)->varId());
if (varid == 0)
continue;
const std::string varname(tok->strAt(3));
const Token *decltok = Token::findmatch(_tokenizer->tokens(), "%varid%", varid);
if (!Token::Match(decltok->tokAt(-3), "[;,(] %var% *"))
continue;
for (const Token *tok1 = tok->previous(); tok1 && tok1 != decltok; tok1 = tok1->previous())
{
if (tok1->varId() == varid)
{
if (Token::Match(tok1->tokAt(-2), "[=;{}] *"))
{
nullPointerError(tok1, varname);
break;
}
else if (tok1->previous() && tok1->previous()->str() == "&")
{
break;
}
else if (tok1->next() && tok1->next()->str() == "=")
{
break;
}
}
else if (tok1->str() == "{" ||
tok1->str() == "}")
break;
// goto destination..
else if (tok1->isName() && Token::simpleMatch(tok1->next(), ":"))
break;
}
}
}
}
void CheckOther::nullPointer()
{
nullPointerAfterLoop();
nullPointerLinkedList();
nullPointerStructByDeRefAndChec();
nullPointerByDeRefAndChec();
}
/** Derefencing null constant (simplified token list) */
void CheckOther::nullConstantDereference()
{
// this is kept at 0 for all scopes that are not executing
unsigned int indentlevel = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// start of executable scope..
if (indentlevel == 0 && Token::Match(tok, ") const| {"))
indentlevel = 1;
else if (indentlevel >= 1)
{
if (tok->str() == "{")
++indentlevel;
else if (tok->str() == "}")
{
if (indentlevel <= 2)
indentlevel = 0;
else
--indentlevel;
}
if (tok->str() == "(" && Token::simpleMatch(tok->previous(), "sizeof"))
tok = tok->link();
else if (Token::simpleMatch(tok, "exit ( )"))
{
// Goto end of scope
while (tok && tok->str() != "}")
{
if (tok->str() == "{")
tok = tok->link();
tok = tok->next();
}
if (!tok)
break;
}
else if (Token::simpleMatch(tok, "* 0"))
{
if (Token::Match(tok->previous(), "[;{}=+-/(,]") ||
Token::Match(tok->previous(), "return|<<"))
{
nullPointerError(tok);
}
}
}
}
}
/**
* \brief parse a function call and extract information about variable usage
* \param tok first token
* \param var variables that the function read / write.
* \param value 0 => invalid with null pointers as parameter.
* 1-.. => invalid with uninitialized data.
*/
static void parseFunctionCall(const Token &tok, std::list<const Token *> &var, unsigned char value)
{
// standard functions that dereference first parameter..
// both uninitialized data and null pointers are invalid.
static std::set<std::string> functionNames1;
if (functionNames1.empty())
{
functionNames1.insert("memchr");
functionNames1.insert("memcmp");
functionNames1.insert("strcat");
functionNames1.insert("strncat");
functionNames1.insert("strchr");
functionNames1.insert("strrchr");
functionNames1.insert("strcmp");
functionNames1.insert("strncmp");
functionNames1.insert("strdup");
functionNames1.insert("strndup");
functionNames1.insert("strlen");
functionNames1.insert("strstr");
}
// standard functions that dereference second parameter..
// both uninitialized data and null pointers are invalid.
static std::set<std::string> functionNames2;
if (functionNames2.empty())
{
functionNames2.insert("memcmp");
functionNames2.insert("memcpy");
functionNames2.insert("memmove");
functionNames2.insert("strcat");
functionNames2.insert("strncat");
functionNames2.insert("strcmp");
functionNames2.insert("strncmp");
functionNames2.insert("strcpy");
functionNames2.insert("strncpy");
functionNames2.insert("strstr");
}
// 1st parameter..
if (Token::Match(&tok, "%var% ( %var% ,|)") && tok.tokAt(2)->varId() > 0)
{
if (functionNames1.find(tok.str()) != functionNames1.end())
var.push_back(tok.tokAt(2));
else if (value == 0 && Token::Match(&tok, "memchr|memcmp|memcpy|memmove|memset|strcpy|printf|sprintf|snprintf"))
var.push_back(tok.tokAt(2));
else if (Token::simpleMatch(&tok, "fflush"))
var.push_back(tok.tokAt(2));
}
// 2nd parameter..
if (Token::Match(&tok, "%var% ( %any% , %var% ,|)") && tok.tokAt(4)->varId() > 0)
{
if (functionNames2.find(tok.str()) != functionNames2.end())
var.push_back(tok.tokAt(4));
}
}
/// @addtogroup Checks
/// @{
/**
* @brief %Check for null pointer usage (using ExecutionPath)
*/
class CheckNullpointer : public ExecutionPath
{
public:
/** Startup constructor */
CheckNullpointer(Check *c) : ExecutionPath(c, 0), null(false)
{
}
private:
/** Create checking of specific variable: */
CheckNullpointer(Check *c, const unsigned int id, const std::string &name)
: ExecutionPath(c, id),
varname(name),
null(false)
{
}
/** Copy this check */
ExecutionPath *copy()
{
return new CheckNullpointer(*this);
}
/** no implementation => compiler error if used by accident */
void operator=(const CheckNullpointer &);
/** is other execution path equal? */
bool is_equal(const ExecutionPath *e) const
{
const CheckNullpointer *c = static_cast<const CheckNullpointer *>(e);
return (varname == c->varname && null == c->null);
}
/** variable name for this check (empty => dummy check) */
const std::string varname;
/** is this variable null? */
bool null;
/** variable is set to null */
static void setnull(std::list<ExecutionPath *> &checks, const unsigned int varid)
{
std::list<ExecutionPath *>::iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckNullpointer *c = dynamic_cast<CheckNullpointer *>(*it);
if (c && c->varId == varid)
c->null = true;
}
}
/**
* Dereferencing variable. Check if it is safe (if the variable is null there's an error)
* @param checks Checks
* @param tok token where dereferencing happens
*/
static void dereference(std::list<ExecutionPath *> &checks, const Token *tok)
{
const unsigned int varid(tok->varId());
std::list<ExecutionPath *>::iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckNullpointer *c = dynamic_cast<CheckNullpointer *>(*it);
if (c && c->varId == varid && c->null)
{
CheckOther *checkOther = dynamic_cast<CheckOther *>(c->owner);
if (checkOther)
{
checkOther->nullPointerError(tok, c->varname);
return;
}
}
}
}
/** parse tokens */
const Token *parse(const Token &tok, std::list<ExecutionPath *> &checks) const
{
if (Token::Match(tok.previous(), "[;{}] const| %type% * %var% ;"))
{
const Token * vartok = tok.tokAt(2);
if (tok.str() == "const")
vartok = vartok->next();
if (vartok->varId() != 0)
checks.push_back(new CheckNullpointer(owner, vartok->varId(), vartok->str()));
return vartok->next();
}
// Template pointer variable..
if (Token::Match(tok.previous(), "[;{}] %type% ::|<"))
{
const Token * vartok = &tok;
while (Token::Match(vartok, "%type% ::"))
vartok = vartok->tokAt(2);
if (Token::Match(vartok, "%type% < %type%"))
{
vartok = vartok->tokAt(3);
while (vartok && (vartok->str() == "*" || vartok->isName()))
vartok = vartok->next();
if (Token::Match(vartok, "> * %var% ;|="))
{
vartok = vartok->tokAt(2);
checks.push_back(new CheckNullpointer(owner, vartok->varId(), vartok->str()));
if (Token::simpleMatch(vartok->next(), "= 0 ;"))
setnull(checks, vartok->varId());
return vartok->next();
}
}
}
if (Token::Match(&tok, "%var% ("))
{
if (tok.str() == "sizeof")
return tok.next()->link();
// parse usage..
std::list<const Token *> var;
parseFunctionCall(tok, var, 0);
for (std::list<const Token *>::const_iterator it = var.begin(); it != var.end(); ++it)
dereference(checks, *it);
}
if (tok.varId() != 0)
{
if (Token::Match(tok.previous(), "[;{}=] %var% = 0 ;"))
setnull(checks, tok.varId());
else if (Token::Match(tok.tokAt(-2), "[;{}=+-/(,] * %var%"))
dereference(checks, &tok);
else if (Token::Match(tok.tokAt(-2), "return * %var%"))
dereference(checks, &tok);
else if (!Token::simpleMatch(tok.tokAt(-2), "& (") && Token::Match(tok.next(), ". %var%"))
dereference(checks, &tok);
else if (Token::Match(tok.previous(), "[;{}=+-/(,] %var% [ %any% ]"))
dereference(checks, &tok);
else if (Token::Match(tok.previous(), "return %var% [ %any% ]"))
dereference(checks, &tok);
else if (Token::Match(&tok, "%var% ("))
dereference(checks, &tok);
else
bailOutVar(checks, tok.varId());
}
else if (tok.str() == "delete")
{
const Token *ret = tok.next();
if (Token::simpleMatch(ret, "[ ]"))
ret = ret->tokAt(2);
if (Token::Match(ret, "%var% ;"))
return ret->next();
}
return &tok;
}
/** parse condition. @sa ExecutionPath::parseCondition */
bool parseCondition(const Token &tok, std::list<ExecutionPath *> &checks)
{
for (const Token *tok2 = &tok; tok2; tok2 = tok2->next())
{
if (tok2->str() == "(" || tok2->str() == ")")
break;
if (Token::Match(tok2, "[<>=] * %var%"))
dereference(checks, tok2->tokAt(2));
}
if (Token::Match(&tok, "!| %var% ("))
{
std::list<const Token *> var;
parseFunctionCall(tok.str() == "!" ? *tok.next() : tok, var, 0);
for (std::list<const Token *>::const_iterator it = var.begin(); it != var.end(); ++it)
dereference(checks, *it);
}
return ExecutionPath::parseCondition(tok, checks);
}
};
/**
* @brief %Check that uninitialized variables aren't used (using ExecutionPath)
* */
class CheckUninitVar : public ExecutionPath
{
public:
/** Startup constructor */
CheckUninitVar(Check *c)
: ExecutionPath(c, 0), pointer(false), array(false), alloc(false), strncpy_(false)
{
}
private:
/** Create a copy of this check */
ExecutionPath *copy()
{
return new CheckUninitVar(*this);
}
/** no implementation => compiler error if used */
void operator=(const CheckUninitVar &);
/** internal constructor for creating extra checks */
CheckUninitVar(Check *c, unsigned int v, const std::string &name, bool p, bool a)
: ExecutionPath(c, v), varname(name), pointer(p), array(a), alloc(false), strncpy_(false)
{
}
/** is other execution path equal? */
bool is_equal(const ExecutionPath *e) const
{
const CheckUninitVar *c = static_cast<const CheckUninitVar *>(e);
return (varname == c->varname && pointer == c->pointer && array == c->array && alloc == c->alloc && strncpy_ == c->strncpy_);
}
/** variable name for this check */
const std::string varname;
/** is this variable a pointer? */
const bool pointer;
/** is this variable an array? */
const bool array;
/** is this variable allocated? */
bool alloc;
/** is this variable initialized with strncpy (not always zero-terminated) */
bool strncpy_;
/** allocating pointer. For example : p = malloc(10); */
static void alloc_pointer(std::list<ExecutionPath *> &checks, unsigned int varid)
{
std::list<ExecutionPath *>::const_iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid)
c->alloc = true;
}
}
/** Initializing a pointer value. For example: *p = 0; */
static void init_pointer(std::list<ExecutionPath *> &checks, const Token *tok)
{
const unsigned int varid(tok->varId());
if (!varid)
return;
std::list<ExecutionPath *>::iterator it = checks.begin();
while (it != checks.end())
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid)
{
if (c->alloc || c->array)
{
delete c;
checks.erase(it++);
continue;
}
else
{
use_pointer(checks, tok);
}
}
++it;
}
}
/** Deallocate a pointer. For example: free(p); */
static void dealloc_pointer(std::list<ExecutionPath *> &checks, const Token *tok)
{
const unsigned int varid(tok->varId());
if (!varid)
return;
std::list<ExecutionPath *>::const_iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid)
{
if (c->pointer && !c->alloc)
{
CheckOther *checkOther = dynamic_cast<CheckOther *>(c->owner);
if (checkOther)
{
checkOther->uninitvarError(tok, c->varname);
break;
}
}
c->alloc = false;
}
}
}
/**
* Pointer assignment: p = x;
* if p is a pointer and x is an array/pointer then bail out
* \param checks all available checks
* \param tok1 the "p" token
* \param tok2 the "x" token
*/
static void pointer_assignment(std::list<ExecutionPath *> &checks, const Token *tok1, const Token *tok2)
{
const unsigned int varid1(tok1->varId());
if (varid1 == 0)
return;
const unsigned int varid2(tok2->varId());
if (varid2 == 0)
return;
std::list<ExecutionPath *>::const_iterator it;
// bail out if first variable is a pointer
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid1 && c->pointer)
{
bailOutVar(checks, varid1);
break;
}
}
// bail out if second variable is a array/pointer
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid2 && (c->pointer || c->array))
{
bailOutVar(checks, varid2);
break;
}
}
}
/** Initialize an array with strncpy. */
static void init_strncpy(std::list<ExecutionPath *> &checks, const Token *tok)
{
const unsigned int varid(tok->varId());
if (!varid)
return;
std::list<ExecutionPath *>::const_iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid)
{
c->strncpy_ = true;
}
}
}
/**
* use - called from the use* functions below.
* @param checks all available checks
* @param tok variable token
* @param mode specific behaviour
* @return if error is found, true is returned
*/
static bool use(std::list<ExecutionPath *> &checks, const Token *tok, const int mode)
{
const unsigned int varid(tok->varId());
if (varid == 0)
return false;
std::list<ExecutionPath *>::const_iterator it;
for (it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varId == varid)
{
// mode 0 : the variable is used "directly"
// example: .. = var;
// it is ok to read the address of an uninitialized array.
// it is ok to read the address of an allocated pointer
if (mode == 0 && (c->array || (c->pointer && c->alloc)))
continue;
// mode 2 : bad usage of pointer. if it's not a pointer then the usage is ok.
// example: ptr->foo();
if (mode == 2 && !c->pointer)
continue;
// mode 3 : using dead pointer is invalid.
if (mode == 3 && (!c->pointer || c->alloc))
continue;
// mode 4 : reading uninitialized array or pointer is invalid.
if (mode == 4 && (!c->array && !c->pointer))
continue;
CheckOther *checkOther = dynamic_cast<CheckOther *>(c->owner);
if (checkOther)
{
if (c->strncpy_)
checkOther->uninitstringError(tok, c->varname);
else if (c->pointer && c->alloc)
checkOther->uninitdataError(tok, c->varname);
else
checkOther->uninitvarError(tok, c->varname);
return true;
}
}
}
// No error found
return false;
}
/**
* Reading variable. Use this function in situations when it is
* invalid to read the data of the variable but not the address.
* @param checks all available checks
* @param tok variable token
* @return if error is found, true is returned
*/
static bool use(std::list<ExecutionPath *> &checks, const Token *tok)
{
return use(checks, tok, 0);
}
/**
* Reading array elements. If the variable is not an array then the usage is ok.
* @param checks all available checks
* @param tok variable token
*/
static void use_array(std::list<ExecutionPath *> &checks, const Token *tok)
{
use(checks, tok, 1);
}
/**
* Bad pointer usage. If the variable is not a pointer then the usage is ok.
* @param checks all available checks
* @param tok variable token
* @return if error is found, true is returned
*/
static bool use_pointer(std::list<ExecutionPath *> &checks, const Token *tok)
{
return use(checks, tok, 2);
}
/**
* Using variable.. if it's a dead pointer the usage is invalid.
* @param checks all available checks
* @param tok variable token
* @return if error is found, true is returned
*/
static bool use_dead_pointer(std::list<ExecutionPath *> &checks, const Token *tok)
{
return use(checks, tok, 3);
}
/**
* Using variable.. reading from uninitialized array or pointer data is invalid.
* Example: = x[0];
* @param checks all available checks
* @param tok variable token
* @return if error is found, true is returned
*/
static bool use_array_or_pointer_data(std::list<ExecutionPath *> &checks, const Token *tok)
{
return use(checks, tok, 4);
}
/** declaring a variable */
void declare(std::list<ExecutionPath *> &checks, const Token *vartok, const Token &tok, const bool p, const bool a) const
{
if (vartok->varId() == 0)
return;
bool isenum = false;
if (!tok.isStandardType())
{
const std::string pattern("enum " + tok.str());
for (const Token *tok2 = tok.previous(); tok2; tok2 = tok2->previous())
{
if (tok2->str() != "{")
continue;
if (Token::simpleMatch(tok2->tokAt(-2), pattern.c_str()))
{
isenum = true;
break;
}
}
}
// Suppress warnings if variable in inner scope has same name as variable in outer scope
if (!tok.isStandardType() && !isenum)
{
std::set<unsigned int> dup;
for (std::list<ExecutionPath *>::const_iterator it = checks.begin(); it != checks.end(); ++it)
{
CheckUninitVar *c = dynamic_cast<CheckUninitVar *>(*it);
if (c && c->varname == vartok->str() && c->varId != vartok->varId())
dup.insert(c->varId);
}
if (!dup.empty())
{
for (std::set<unsigned int>::const_iterator it = dup.begin(); it != dup.end(); ++it)
bailOutVar(checks, *it);
return;
}
}
if (a || p || tok.isStandardType() || isenum)
checks.push_back(new CheckUninitVar(owner, vartok->varId(), vartok->str(), p, a));
}
/** parse tokens. @sa ExecutionPath::parse */
const Token *parse(const Token &tok, std::list<ExecutionPath *> &checks) const
{
// Variable declaration..
if (Token::Match(tok.previous(), "[;{}] %var%") && tok.str() != "return")
{
if (Token::Match(&tok, "enum %type% {"))
return tok.tokAt(2)->link();
const Token * vartok = &tok;
while (Token::Match(vartok, "const|struct"))
vartok = vartok->next();
if (Token::Match(vartok, "%type% *| %var% ;"))
{
vartok = vartok->next();
const bool p(vartok->str() == "*");
if (p)
vartok = vartok->next();
declare(checks, vartok, tok, p, false);
return vartok;
}
// Variable declaration for array..
if (Token::Match(vartok, "%type% %var% [ %num% ] ;"))
{
vartok = vartok->next();
declare(checks, vartok, tok, false, true);
return vartok->next()->link();
}
// Template pointer variable..
if (Token::Match(vartok, "%type% ::|<"))
{
while (Token::Match(vartok, "%type% ::"))
vartok = vartok->tokAt(2);
if (Token::Match(vartok, "%type% < %type%"))
{
vartok = vartok->tokAt(3);
while (vartok && (vartok->str() == "*" || vartok->isName()))
vartok = vartok->next();
if (Token::Match(vartok, "> * %var% ;"))
{
declare(checks, vartok->tokAt(2), tok, true, false);
return vartok->tokAt(2);
}
}
}
}
if (tok.varId())
{
// Used..
if (Token::Match(tok.previous(), "[[(,+-*/] %var% []),+-*/]"))
{
use(checks, &tok);
return &tok;
}
if (Token::Match(tok.previous(), "++|--") || Token::Match(tok.next(), "++|--"))
{
use(checks, &tok);
return &tok;
}
if (Token::Match(tok.previous(), "[;{}] %var% =|[|."))
{
if (tok.next()->str() == ".")
{
if (use_dead_pointer(checks, &tok))
{
return &tok;
}
}
else
{
// check variable usages in rhs/index
for (const Token *tok2 = tok.tokAt(2); tok2; tok2 = tok2->next())
{
if (Token::Match(tok2, ";|)|="))
break;
if (Token::Match(tok2, "%var% ("))
break;
if (tok2->varId() &&
!Token::Match(tok2->previous(), "&|::") &&
!Token::simpleMatch(tok2->next(), "="))
{
bool foundError;
if (tok2->next()->str() == "[")
foundError = use_array_or_pointer_data(checks, tok2);
else
foundError = use(checks, tok2);
// prevent duplicate error messages
if (foundError)
{
bailOutVar(checks, tok2->varId());
}
}
}
}
// pointer aliasing?
if (Token::Match(tok.tokAt(2), "%var% ;"))
{
pointer_assignment(checks, &tok, tok.tokAt(2));
}
}
if (Token::simpleMatch(tok.next(), "("))
{
use_pointer(checks, &tok);
}
if (Token::Match(tok.tokAt(-2), "[;{}] *"))
{
if (Token::simpleMatch(tok.next(), "="))
init_pointer(checks, &tok);
else
use_pointer(checks, &tok);
return &tok;
}
// += etc
if (Token::Match(tok.previous(), "[;{}]") || Token::Match(tok.tokAt(-2), "[;{}] *"))
{
// goto the equal..
const Token *eq = tok.next();
if (eq && eq->str() == "[" && eq->link() && eq->link()->next())
eq = eq->link()->next();
// is it X=
if (Token::Match(eq, "+=|-=|*=|/=|&=|^=") || eq->str() == "|=")
{
if (tok.previous()->str() == "*")
use_pointer(checks, &tok);
else if (tok.next()->str() == "[")
use_array(checks, &tok);
else
use(checks, &tok);
}
}
if (Token::Match(tok.next(), "= malloc|kmalloc") || Token::simpleMatch(tok.next(), "= new char ["))
{
alloc_pointer(checks, tok.varId());
if (tok.tokAt(3)->str() == "(")
return tok.tokAt(3);
}
else if (Token::simpleMatch(tok.previous(), ">>") || Token::simpleMatch(tok.next(), "="))
{
ExecutionPath::bailOutVar(checks, tok.varId());
return &tok;
}
if (Token::simpleMatch(tok.next(), "["))
{
const Token *tok2 = tok.next()->link();
if (Token::simpleMatch(tok2 ? tok2->next() : 0, "="))
{
ExecutionPath::bailOutVar(checks, tok.varId());
return &tok;
}
}
if (Token::simpleMatch(tok.previous(), "delete") ||
Token::simpleMatch(tok.tokAt(-3), "delete [ ]"))
{
dealloc_pointer(checks, &tok);
return &tok;
}
}
if (Token::Match(&tok, "%var% (") && uvarFunctions.find(tok.str()) == uvarFunctions.end())
{
if (Token::simpleMatch(&tok, "sizeof ("))
return tok.next()->link();
// deallocate pointer
if (Token::Match(&tok, "free|kfree|fclose ( %var% )"))
{
dealloc_pointer(checks, tok.tokAt(2));
return tok.tokAt(3);
}
// parse usage..
{
std::list<const Token *> var;
parseFunctionCall(tok, var, 1);
for (std::list<const Token *>::const_iterator it = var.begin(); it != var.end(); ++it)
use_array(checks, *it);
// Using uninitialized pointer is bad if using null pointer is bad
std::list<const Token *> var2;
parseFunctionCall(tok, var2, 0);
for (std::list<const Token *>::const_iterator it = var2.begin(); it != var2.end(); ++it)
{
if (std::find(var.begin(), var.end(), *it) == var.end())
use_dead_pointer(checks, *it);
}
}
// strncpy doesn't 0-terminate first parameter
if (Token::Match(&tok, "strncpy ( %var% ,"))
{
init_strncpy(checks, tok.tokAt(2));
return tok.next()->link();
}
if (Token::Match(&tok, "asm ( )"))
{
ExecutionPath::bailOut(checks);
return &tok;
}
// is the variable passed as a parameter to some function?
unsigned int parlevel = 0;
std::set<unsigned int> bailouts;
for (const Token *tok2 = tok.next(); tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
++parlevel;
else if (tok2->str() == ")")
{
if (parlevel <= 1)
break;
--parlevel;
}
else if (Token::simpleMatch(tok2, "sizeof ("))
{
tok2 = tok2->next()->link();
if (!tok2)
break;
}
else if (tok2->varId())
{
if (Token::Match(tok2->tokAt(-2), "[(,] *") || Token::Match(tok2->next(), ". %var%"))
{
if (use_dead_pointer(checks, tok2))
ExecutionPath::bailOutVar(checks, tok2->varId());
}
// it is possible that the variable is initialized here
if (Token::Match(tok2->previous(), "[(,] %var% [,)]"))
bailouts.insert(tok2->varId());
}
}
for (std::set<unsigned int>::const_iterator it = bailouts.begin(); it != bailouts.end(); ++it)
ExecutionPath::bailOutVar(checks, *it);
}
// function call via function pointer
if (Token::Match(&tok, "( * %var% ) ("))
{
// is the variable passed as a parameter to some function?
unsigned int parlevel = 0;
for (const Token *tok2 = tok.link()->next(); tok2; tok2 = tok2->next())
{
if (tok2->str() == "(")
++parlevel;
else if (tok2->str() == ")")
{
if (parlevel <= 1)
break;
--parlevel;
}
else if (tok2->varId())
{
// it is possible that the variable is initialized here
ExecutionPath::bailOutVar(checks, tok2->varId());
}
}
}
if (tok.str() == "return")
{
// Todo: if (!array && ..
if (Token::Match(tok.next(), "%var% ;"))
{
use(checks, tok.next());
}
}
if (tok.varId())
{
if (Token::simpleMatch(tok.previous(), "="))
{
if (Token::Match(tok.tokAt(-3), "& %var% ="))
{
bailOutVar(checks, tok.varId());
return &tok;
}
if (!Token::Match(tok.tokAt(-3), ". %var% ="))
{
if (!Token::Match(tok.tokAt(-3), "[;{}] %var% ="))
{
use(checks, &tok);
return &tok;
}
const unsigned int varid2 = tok.tokAt(-2)->varId();
if (varid2)
{
/*
const Token *tok2 = Token::findmatch(owner->_tokenizer->tokens(), "%varid%", varid2);
if (tok2 && !Token::simpleMatch(tok2->previous(), "*"))
*/
{
use(checks, &tok);
return &tok;
}
}
}
}
if (Token::simpleMatch(tok.next(), "."))
{
const Token *tok2 = tok.next();
while (Token::Match(tok2, ". %var%"))
tok2 = tok2->tokAt(2);
if (tok2 && tok2->str() != "=")
use_pointer(checks, &tok);
else
bailOutVar(checks, tok.varId());
return &tok;
}
if (Token::simpleMatch(tok.next(), "["))
{
ExecutionPath::bailOutVar(checks, tok.varId());
return &tok;
}
if (Token::Match(tok.tokAt(-2), "[,(=] *"))
{
use_pointer(checks, &tok);
return &tok;
}
if (Token::simpleMatch(tok.previous(), "&"))
{
ExecutionPath::bailOutVar(checks, tok.varId());
}
}
// Parse "for"
if (Token::Match(&tok, "[;{}] for ("))
{
// initialized variables
std::set<unsigned int> varid1;
varid1.insert(0);
// Parse token
const Token *tok2;
// parse setup
for (tok2 = tok.tokAt(3); tok2; tok2 = tok2->next())
{
if (tok2->str() == ";")
break;
if (tok2->varId())
varid1.insert(tok2->varId());
}
// parse condition
if (Token::Match(tok2, "; %var% <|<=|>=|> %num% ;"))
{
// If the variable hasn't been initialized then call "use"
if (varid1.find(tok2->next()->varId()) == varid1.end())
use(checks, tok2->next());
}
// goto stepcode
tok2 = tok2->next();
while (tok2 && tok2->str() != ";")
tok2 = tok2->next();
// parse the stepcode
if (Token::Match(tok2, "; ++|-- %var% ) {") ||
Token::Match(tok2, "; %var% ++|-- ) {"))
{
// get id of variable..
unsigned int varid = tok2->next()->varId();
if (!varid)
varid = tok2->tokAt(2)->varId();
// Check that the variable hasn't been initialized and
// that it isn't initialized in the body..
if (varid1.find(varid) == varid1.end())
{
unsigned int indentlevel = 0;
for (const Token *tok3 = tok2->tokAt(5); tok3; tok3 = tok3->next())
{
if (tok3->str() == "{")
++indentlevel;
else if (tok3->str() == "}")
{
if (indentlevel == 0)
break;
--indentlevel;
}
if (tok3->varId() == varid)
{
varid = 0; // variable is used.. maybe it's initialized. clear the variable id.
break;
}
}
// If the variable isn't initialized in the body call "use"
if (varid != 0)
{
// goto variable
tok2 = tok2->next();
if (!tok2->varId())
tok2 = tok2->next();
// call "use"
use(checks, tok2);
}
}
}
}
return &tok;
}
bool parseCondition(const Token &tok, std::list<ExecutionPath *> &checks)
{
if (tok.varId() && Token::Match(&tok, "%var% <|<=|==|!=|)|["))
use(checks, &tok);
else if (Token::Match(&tok, "!| %var% ("))
{
std::list<const Token *> var;
parseFunctionCall(tok.str() == "!" ? *tok.next() : tok, var, 1);
for (std::list<const Token *>::const_iterator it = var.begin(); it != var.end(); ++it)
use_array(checks, *it);
}
else if (Token::Match(&tok, "! %var% )"))
{
use(checks, &tok);
return false;
}
return ExecutionPath::parseCondition(tok, checks);
}
public:
/** Functions that don't handle uninitialized variables well */
static std::set<std::string> uvarFunctions;
static void analyseFunctions(const Token * const tokens, std::set<std::string> &func)
{
for (const Token *tok = tokens; tok; tok = tok->next())
{
if (tok->str() == "{")
{
tok = tok->link();
continue;
}
if (tok->str() != "::" && Token::Match(tok->next(), "%var% ( %type%"))
{
if (!Token::simpleMatch(tok->tokAt(2)->link(), ") {"))
continue;
const Token *tok2 = tok->tokAt(3);
while (tok2 && tok2->str() != ")")
{
if (tok2->str() == ",")
tok2 = tok2->next();
if (Token::Match(tok2, "%type% %var% ,|)") && tok2->isStandardType())
{
tok2 = tok2->tokAt(2);
continue;
}
if (tok2->isStandardType() && Token::Match(tok2, "%type% & %var% ,|)"))
{
const unsigned int varid(tok2->tokAt(2)->varId());
// flags for read/write
bool r = false, w = false;
// check how the variable is used in the function
unsigned int indentlevel = 0;
for (const Token *tok3 = tok2; tok3; tok3 = tok3->next())
{
if (tok3->str() == "{")
++indentlevel;
else if (tok3->str() == "}")
{
if (indentlevel <= 1)
break;
--indentlevel;
}
else if (indentlevel == 0 && tok3->str() == ";")
break;
else if (indentlevel >= 1 && tok3->varId() == varid)
{
if (Token::Match(tok3->previous(), "++|--") ||
Token::Match(tok3->next(), "++|--"))
{
r = true;
}
else
{
w = true;
break;
}
}
}
if (!r || w)
break;
tok2 = tok2->tokAt(3);
continue;
}
if (Token::Match(tok2, "const %type% &|*| const| %var% ,|)") && tok2->next()->isStandardType())
{
tok2 = tok2->tokAt(3);
while (tok2->isName())
tok2 = tok2->next();
continue;
}
break;
}
// found simple function..
if (tok2->link() == tok->tokAt(2))
func.insert(tok->next()->str());
}
}
}
};
/** Functions that don't handle uninitialized variables well */
std::set<std::string> CheckUninitVar::uvarFunctions;
/// @}
void CheckOther::analyse(const Token * const tokens, std::set<std::string> &func) const
{
CheckUninitVar::analyseFunctions(tokens, func);
}
void CheckOther::saveAnalysisData(const std::set<std::string> &data) const
{
CheckUninitVar::uvarFunctions.insert(data.begin(), data.end());
}
void CheckOther::executionPaths()
{
// Check for null pointer errors..
{
CheckNullpointer c(this);
checkExecutionPaths(_tokenizer->tokens(), &c);
}
// check if variable is accessed uninitialized..
{
// no writing if multiple threads are used (TODO: thread safe analysis?)
if (_settings->_jobs == 1)
CheckUninitVar::analyseFunctions(_tokenizer->tokens(), CheckUninitVar::uvarFunctions);
CheckUninitVar c(this);
checkExecutionPaths(_tokenizer->tokens(), &c);
}
}
void CheckOther::checkZeroDivision()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "/ %num%") &&
MathLib::isInt(tok->next()->str()) &&
MathLib::toLongNumber(tok->next()->str()) == 0L)
{
zerodivError(tok);
}
else if (Token::Match(tok, "div|ldiv|lldiv|imaxdiv ( %num% , %num% )") &&
MathLib::isInt(tok->tokAt(4)->str()) &&
MathLib::toLongNumber(tok->tokAt(4)->str()) == 0L)
{
zerodivError(tok);
}
}
}
void CheckOther::checkMathFunctions()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// case log(-2)
if (Token::Match(tok, "log|log10 ( %num% )") &&
MathLib::isNegative(tok->tokAt(2)->str()) &&
MathLib::isInt(tok->tokAt(2)->str()) &&
MathLib::toLongNumber(tok->tokAt(2)->str()) <= 0)
{
mathfunctionCallError(tok);
}
// case log(-2.0)
else if (Token::Match(tok, "log|log10 ( %num% )") &&
MathLib::isNegative(tok->tokAt(2)->str()) &&
MathLib::isFloat(tok->tokAt(2)->str()) &&
MathLib::toDoubleNumber(tok->tokAt(2)->str()) <= 0.)
{
mathfunctionCallError(tok);
}
// case log(0.0)
else if (Token::Match(tok, "log|log10 ( %num% )") &&
!MathLib::isNegative(tok->tokAt(2)->str()) &&
MathLib::isFloat(tok->tokAt(2)->str()) &&
MathLib::toDoubleNumber(tok->tokAt(2)->str()) <= 0.)
{
mathfunctionCallError(tok);
}
// case log(0)
else if (Token::Match(tok, "log|log10 ( %num% )") &&
!MathLib::isNegative(tok->tokAt(2)->str()) &&
MathLib::isInt(tok->tokAt(2)->str()) &&
MathLib::toLongNumber(tok->tokAt(2)->str()) <= 0)
{
mathfunctionCallError(tok);
}
// acos( x ), asin( x ) where x is defined for intervall [-1,+1], but not beyound
else if (Token::Match(tok, "acos|asin ( %num% )") &&
std::fabs(MathLib::toDoubleNumber(tok->tokAt(2)->str())) > 1.0)
{
mathfunctionCallError(tok);
}
// sqrt( x ): if x is negative the result is undefined
else if (Token::Match(tok, "sqrt ( %num% )") &&
MathLib::isNegative(tok->tokAt(2)->str()))
{
mathfunctionCallError(tok);
}
// atan2 ( x , y): x and y can not be zero, because this is mathematically not defined
else if (Token::Match(tok, "atan2 ( %num% , %num% )") &&
MathLib::isNullValue(tok->tokAt(2)->str()) &&
MathLib::isNullValue(tok->tokAt(4)->str()))
{
mathfunctionCallError(tok, 2);
}
// fmod ( x , y) If y is zero, then either a range error will occur or the function will return zero (implementation-defined).
else if (Token::Match(tok, "fmod ( %num% , %num% )") &&
MathLib::isNullValue(tok->tokAt(4)->str()))
{
mathfunctionCallError(tok, 2);
}
// pow ( x , y) If x is zero, and y is negative --> division by zero
else if (Token::Match(tok, "pow ( %num% , %num% )") &&
MathLib::isNullValue(tok->tokAt(2)->str()) &&
MathLib::isNegative(tok->tokAt(4)->str()))
{
mathfunctionCallError(tok, 2);
}
}
}
void CheckOther::postIncrement()
{
if (!_settings->_checkCodingStyle || !_settings->inconclusive)
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::simpleMatch(tok, "for ("))
{
const Token *tok2 = tok->next()->link();
if (tok2)
tok2 = tok2->tokAt(-3);
if (Token::Match(tok2, "; %var% ++|-- )"))
{
if (tok2->next()->varId() == 0)
continue;
// Take a look at the variable declaration
const Token *decltok = Token::findmatch(_tokenizer->tokens(), "%varid%", tok2->tokAt(1)->varId());
const std::string classDef = std::string("class ") + std::string(decltok->previous()->strAt(0));
// Is the variable an iterator?
if (decltok && Token::Match(decltok->previous(), "iterator|const_iterator"))
postIncrementError(tok2, tok2->strAt(1), (std::string("++") == tok2->strAt(2)));
// Is the variable a class?
else if (Token::findmatch(_tokenizer->tokens(), classDef.c_str()))
postIncrementError(tok2, tok2->strAt(1), (std::string("++") == tok2->strAt(2)));
}
}
}
}
void CheckOther::cstyleCastError(const Token *tok)
{
reportError(tok, Severity::style, "cstyleCast", "C-style pointer casting");
}
void CheckOther::redundantIfDelete0Error(const Token *tok)
{
reportError(tok, Severity::style, "redundantIfDelete0", "Redundant condition. It is safe to deallocate a NULL pointer");
}
void CheckOther::redundantIfRemoveError(const Token *tok)
{
reportError(tok, Severity::style, "redundantIfRemove", "Redundant condition. The remove function in the STL will not do anything if element doesn't exist");
}
void CheckOther::dangerousUsageStrtolError(const Token *tok)
{
reportError(tok, Severity::error, "dangerousUsageStrtol", "Invalid radix in call to strtol or strtoul. Must be 0 or 2-36");
}
void CheckOther::sprintfOverlappingDataError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "sprintfOverlappingData", "Undefined behaviour: " + varname + " is used wrong in call to sprintf or snprintf. Quote: If copying takes place between objects that overlap as a result of a call to sprintf() or snprintf(), the results are undefined.");
}
void CheckOther::udivError(const Token *tok)
{
reportError(tok, Severity::error, "udivError", "Unsigned division. The result will be wrong.");
}
void CheckOther::unusedStructMemberError(const Token *tok, const std::string &structname, const std::string &varname)
{
reportError(tok, Severity::style, "unusedStructMember", "struct or union member '" + structname + "::" + varname + "' is never used");
}
void CheckOther::passedByValueError(const Token *tok, const std::string &parname)
{
reportError(tok, Severity::style, "passedByValue", "Function parameter '" + parname + "' is passed by value. It could be passed by reference instead.");
}
void CheckOther::constStatementError(const Token *tok, const std::string &type)
{
reportError(tok, Severity::style, "constStatement", "Redundant code: Found a statement that begins with " + type + " constant");
}
void CheckOther::charArrayIndexError(const Token *tok)
{
reportError(tok, Severity::style, "charArrayIndex", "Warning - using char variable as array index");
}
void CheckOther::charBitOpError(const Token *tok)
{
reportError(tok, Severity::style, "charBitOp", "Warning - using char variable in bit operation");
}
void CheckOther::variableScopeError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::style, "variableScope", "The scope of the variable " + varname + " can be reduced");
}
void CheckOther::conditionAlwaysTrueFalse(const Token *tok, const std::string &truefalse)
{
reportError(tok, Severity::style, "conditionAlwaysTrueFalse", "Condition is always " + truefalse);
}
void CheckOther::strPlusChar(const Token *tok)
{
reportError(tok, Severity::error, "strPlusChar", "Unusual pointer arithmetic");
}
void CheckOther::nullPointerError(const Token *tok)
{
reportError(tok, Severity::error, "nullPointer", "Null pointer dereference");
}
void CheckOther::nullPointerError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "nullPointer", "Possible null pointer dereference: " + varname);
}
void CheckOther::nullPointerError(const Token *tok, const std::string &varname, const int line)
{
reportError(tok, Severity::error, "nullPointer", "Possible null pointer dereference: " + varname + " - otherwise it is redundant to check if " + varname + " is null at line " + MathLib::toString<long>(line));
}
void CheckOther::uninitstringError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "uninitstring", "Dangerous usage of '" + varname + "' (strncpy doesn't always 0-terminate it)");
}
void CheckOther::uninitdataError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "uninitdata", "Data is allocated but not initialized: " + varname);
}
void CheckOther::uninitvarError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "uninitvar", "Uninitialized variable: " + varname);
}
void CheckOther::zerodivError(const Token *tok)
{
reportError(tok, Severity::error, "zerodiv", "Division by zero");
}
void CheckOther::mathfunctionCallError(const Token *tok, const unsigned int numParam)
{
if (tok)
{
if (numParam == 1)
reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->tokAt(2)->str() + " to " + tok->str() + "() leads to undefined result");
else if (numParam == 2)
reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->tokAt(2)->str() + " and " + tok->tokAt(4)->str() + " to " + tok->str() + "() leads to undefined result");
}
else
reportError(tok, Severity::error, "wrongmathcall", "Passing value " " to " "() leads to undefined result");
}
void CheckOther::postIncrementError(const Token *tok, const std::string &var_name, const bool isIncrement)
{
std::string type = (isIncrement ? "Incrementing" : "Decrementing");
reportError(tok, Severity::style, "postIncrementDecrement", ("Pre-" + type + " variable '" + var_name + "' is preferred to Post-" + type));
}
void CheckOther::emptyStringTestError(const Token *tok, const std::string &var_name, const bool isTestForEmpty)
{
if (isTestForEmpty)
{
reportError(tok, Severity::style,
"emptyStringTest", "Empty string test can be simplified to \"*" + var_name + " == '\\0'\"");
}
else
{
reportError(tok, Severity::style,
"emptyStringTest", "Non-empty string test can be simplified to \"*" + var_name + " != '\\0'\"");
}
}
void CheckOther::fflushOnInputStreamError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error,
"fflushOnInputStream", "fflush() called on input stream \"" + varname + "\" may result in undefined behaviour");
}
void CheckOther::sizeofsizeof()
{
if (!_settings->_checkCodingStyle)
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::simpleMatch(tok, "sizeof sizeof"))
sizeofsizeofError(tok);
}
}
void CheckOther::sizeofsizeofError(const Token *tok)
{
reportError(tok, Severity::style,
"sizeofsizeof", "Suspicios code 'sizeof sizeof ..', most likely there should only be one sizeof. The current code is equivalent with 'sizeof(size_t)'.");
}
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