cppcheck/lib/checkother.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2009 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"
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#include "tokenize.h"
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#include <algorithm>
#include <list>
#include <map>
#include <sstream>
#include <cstring>
#include <cctype>
//---------------------------------------------------------------------------
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// Register this check class (by creating a static instance of it)
namespace
{
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CheckOther instance;
}
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//---------------------------------------------------------------------------
void CheckOther::warningOldStylePointerCast()
{
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;
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cstyleCastError(tok);
}
}
//---------------------------------------------------------------------------
// Redundant code..
//---------------------------------------------------------------------------
void CheckOther::warningRedundantCode()
{
// if (p) delete p
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (! Token::simpleMatch(tok, "if ("))
continue;
std::string varname;
const Token *tok2 = tok->tokAt(2);
/*
* Possible if-constructions:
*
* if (var)
* if (this->var)
* if (Foo::var)
*
**/
while (Token::Match(tok2, "%var% .|::"))
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{
varname.append(tok2->str());
varname.append(tok2->next()->str());
tok2 = tok2->tokAt(2);
}
if (!Token::Match(tok2, "%var% ) {"))
continue;
varname.append(tok2->str());
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;
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if (Token::Match(tok2, "free|kfree ("))
{
tok2 = tok2->tokAt(2);
funcHasBracket = true;
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}
else if (tok2->str() == "delete")
{
tok2 = tok2->next();
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if (Token::simpleMatch(tok2, "[ ]"))
{
tok2 = tok2->tokAt(2);
}
}
std::string varname2;
while (Token::Match(tok2, "%var% ::|."))
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{
varname2.append(tok2->str());
varname2.append(tok2->next()->str());
tok2 = tok2->tokAt(2);
}
varname2.append(tok2->str());
if (Token::Match(tok2, "%var%") && varname == varname2)
tok2 = tok2->next();
else
continue;
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if (funcHasBracket)
{
if (tok2->str() != ")")
{
continue;
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}
else
{
tok2 = tok2->next();
}
}
if (!Token::Match(tok2, "; } !!else"))
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{
continue;
}
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())
{
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redundantIfRemoveError(tok);
}
tok = Token::findmatch(tok->next(), pattern);
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// 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)))
{
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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;
}
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else if (parlevel == 0 && Token::Match(tok2, ", %varid% [,)]", varid))
{
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sprintfOverlappingDataError(tok2->next(), tok2->next()->str());
break;
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check for unsigned divisions
//---------------------------------------------------------------------------
void CheckOther::checkUnsignedDivision()
{
if (!_settings->_showAll || !_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% [;=,)]"))
{
const char *type = tok->strAt(1);
if (strcmp(type, "char") == 0 || strcmp(type, "short") == 0 || strcmp(type, "int") == 0)
varsign[tok->tokAt(2)->varId()] = 's';
}
else if (Token::Match(tok, "[{};(,] unsigned %type% %var% [;=,)]"))
varsign[tok->tokAt(3)->varId()] = 'u';
else if (!Token::Match(tok, "[).]") && Token::Match(tok->next(), "%var% / %var%"))
{
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if (ErrorLogger::udivWarning(*_settings))
{
char sign1 = varsign[tok->tokAt(1)->varId()];
char sign2 = varsign[tok->tokAt(3)->varId()];
if (sign1 && sign2 && sign1 != sign2)
{
// One of the operands are signed, the other is unsigned..
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udivWarning(tok->next());
}
}
}
else if (!Token::Match(tok, "[).]") && Token::Match(tok->next(), "%var% / %num%"))
{
if (tok->strAt(3)[0] == '-' && ErrorLogger::udivError())
{
char sign1 = varsign[tok->tokAt(1)->varId()];
if (sign1 == 'u')
{
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udivError(tok->next());
}
}
}
else if (Token::Match(tok, "[([=*/+-,] %num% / %var%"))
{
if (tok->strAt(1)[0] == '-' && ErrorLogger::udivError())
{
char sign2 = varsign[tok->tokAt(3)->varId()];
if (sign2 == 'u')
{
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udivError(tok->next());
}
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check scope of variables..
//---------------------------------------------------------------------------
void CheckOther::checkVariableScope()
{
// 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 (Token::Match(tok1, "%type% %var% [;=]"))
{
lookupVar(tok1, tok1->strAt(1));
}
}
}
}
//---------------------------------------------------------------------------
void CheckOther::lookupVar(const Token *tok1, const char 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 used = false, used1 = false;
int indentlevel = 0;
int parlevel = 0;
bool for_or_while = false;
while (tok)
{
if (tok->str() == "{")
{
++indentlevel;
}
else if (tok->str() == "}")
{
if (indentlevel == 0)
break;
--indentlevel;
if (indentlevel == 0)
{
if (for_or_while && used)
return;
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used1 |= used;
used = 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 || used1)
return;
used = true;
}
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()->next(), "{"))
{
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 (!used && used1)
variableScopeError(tok1, varname);
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check for constant function parameters
//---------------------------------------------------------------------------
void CheckOther::checkConstantFunctionParameter()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "[,(] const std :: %type% %var% [,)]"))
{
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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()))
{
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passedByValueError(tok, tok->strAt(3));
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Check that all struct members are used
//---------------------------------------------------------------------------
void CheckOther::checkStructMemberUsage()
{
const char *structname = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (tok->fileIndex() != 0)
continue;
if (Token::Match(tok, "struct|union %type% {"))
{
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 = 0;
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 = 0;
}
if (tok->str() == "}")
structname = 0;
if (structname && Token::Match(tok, "[{;]"))
{
const char *varname = 0;
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;
const std::string usagePattern(". " + std::string(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)
{
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unusedStructMemberError(tok->next(), structname, varname);
}
}
}
}
//---------------------------------------------------------------------------
// Check usage of char variables..
//---------------------------------------------------------------------------
void CheckOther::checkCharVariable()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Declaring the variable..
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if (Token::Match(tok, "[{};(,] signed| char %var% [;=,)]"))
{
// Set tok to point to the variable name
tok = tok->tokAt(2);
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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()))
{
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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..
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charBitOpError(tok2);
break;
}
}
}
}
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// Incomplete statement..
//---------------------------------------------------------------------------
void CheckOther::checkIncompleteStatement()
{
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;
}
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if (Token::Match(tok, "[;{}] %str%") && !Token::Match(tok->tokAt(2), "[,}]"))
{
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constStatementError(tok->next(), "string");
}
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if (Token::Match(tok, "[;{}] %num%") && !Token::Match(tok->tokAt(2), "[,}]"))
{
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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 %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 char *s = tok->strAt(3);
if (*s == '\'')
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strPlusChar(tok->next());
// char variable..
unsigned int varid = tok->tokAt(3)->varId();
if (varid > 0 && varid < 10000 && charVars[varid])
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strPlusChar(tok->next());
}
}
}
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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;
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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);
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::nullPointerConditionalAssignment()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// 1. Initialize..
if (!Token::Match(tok, "; %var% = 0 ;"))
continue;
const unsigned int varid(tok->next()->varId());
if (!varid)
continue;
for (const Token *tok2 = tok->tokAt(4); tok2; tok2 = tok2->next())
{
if (tok2->str() == "{" || tok2->str() == "}")
break;
if (Token::simpleMatch(tok2, "if ("))
{
const Token *tok3 = tok2;
tok3 = tok3->next()->link();
if (!tok3)
break;
// check if the condition contains the variable..
for (const Token *tok4 = tok2->tokAt(2); tok4 && tok4 != tok3; tok4 = tok4->next())
{
if (tok4->varId() == varid)
{
// The condition contains the variable..
// to avoid false positives I bail out..
tok3 = 0;
break;
}
}
if (!tok3)
break;
if (tok3->next()->str() == "{")
{
tok2 = tok3->next()->link();
if (!tok2)
break;
}
continue;
}
if (Token::Match(tok2, "else !!if"))
break;
if (Token::Match(tok2, "%varid%", varid))
{
if (Token::Match(tok2, "%varid% . %var% (", varid))
{
const Token *tempTok = Token::findmatch(_tokenizer->tokens(), "%type% * %varid% [;)=]", varid);
if (tempTok)
nullPointerError(tok2, tok->next()->str());
}
break;
}
}
}
}
void CheckOther::nullPointer()
{
nullPointerAfterLoop();
nullPointerLinkedList();
nullPointerStructByDeRefAndChec();
nullPointerByDeRefAndChec();
nullPointerConditionalAssignment();
}
static const Token *uninitvar_checkscope(const Token * const tokens, const Token *tok, const unsigned int varid, bool &init, const bool pointer, const bool array)
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{
/* limit the checking in conditional code..
* int x;
* if (y)
* x = 33;
* if (y)
* return x;
*/
bool limit = false;
for (; tok; tok = tok->next())
{
if (tok->str() == "}")
return 0;
// todo: handle for/while
if (Token::Match(tok, "for|while|switch"))
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{
init = true;
return 0;
}
if (Token::Match(tok, "= {"))
{
tok = tok->next()->link();
if (!tok)
{
init = true;
return 0;
}
continue;
}
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if (tok->str() == "if")
{
bool canInit = false;
bool ifInit = true;
while (tok->str() == "if")
{
// goto "("
tok = tok->next();
// goto ")"
tok = tok ? tok->link() : 0;
// Check if the condition contains the variable
if (tok)
{
for (const Token *tok2 = tok->link(); tok2 && tok2 != tok; tok2 = tok2->next())
{
// The variable may be initialized..
// if (someFunction(&var)) ..
if (tok2->varId())
{
init = true;
return 0;
}
}
}
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// goto "{"
tok = tok ? tok->next() : 0;
if (!Token::simpleMatch(tok, "{"))
return 0;
// Recursively check into the if ..
bool init2 = false;
const Token *tokerr = uninitvar_checkscope(tokens, tok->next(), varid, init2, pointer, array);
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if (!limit && tokerr)
return tokerr;
// if the scope didn't initialize then this whole if-chain is treated as non-initializing
ifInit &= init2;
canInit |= init2;
// goto "}"
tok = tok->link();
// there is no else => not initialized
if (Token::Match(tok, "} !!else"))
{
ifInit = false;
break;
}
// parse next "if"..
tok = tok->tokAt(2);
if (tok->str() == "if")
continue;
// there is no "if"..
init2 = false;
tokerr = uninitvar_checkscope(tokens, tok->next(), varid, init2, pointer, array);
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if (!limit && tokerr)
return tokerr;
ifInit &= init2;
canInit |= init2;
tok = tok->link();
if (!tok)
return 0;
}
if (ifInit)
{
init = true;
return 0;
}
if (canInit)
{
limit = true;
}
}
if (Token::Match(tok, "%varid%", varid))
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{
if (Token::simpleMatch(tok->previous(), ">>") || Token::simpleMatch(tok->next(), "="))
{
init = true;
return 0;
}
if (Token::simpleMatch(tok->next(), "["))
{
const Token *tok2 = tok->next()->link();
if (Token::simpleMatch(tok2 ? tok2->next() : 0, "="))
{
init = true;
return 0;
}
}
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}
if (Token::Match(tok, "%var% ("))
{
if (Token::Match(tok, "strlen ( %varid% )", varid))
return tok->tokAt(2);
if (Token::Match(tok, "strcpy|strcat|strncpy|strncat|memcpy ( %any% , %varid% [,)]", varid))
return tok->tokAt(4);
if (Token::Match(tok, "strcat|strncat ( %varid% ,", varid))
return tok->tokAt(3);
if (Token::Match(tok, "strncpy ( %varid%", varid))
{
tok = tok->tokAt(3);
continue;
}
if (Token::Match(tok, "asm ( )"))
{
init = true;
return 0;
}
// is the variable passed as a parameter to some function?
unsigned int parlevel = 0;
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 (tok2->varId() == varid)
{
// it is possible that the variable is initialized here
init = true;
return 0;
}
}
}
if (tok->str() == "return")
{
for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
{
if (tok2->str() == ";")
return 0;
if (tok2->varId() == varid)
break;
}
}
if (tok->varId() == varid)
{
if (array && !Token::simpleMatch(tok->next(), "["))
continue;
if (Token::simpleMatch(tok->previous(), "return"))
return tok;
if (Token::simpleMatch(tok->previous(), "="))
{
if (!Token::Match(tok->tokAt(-3), ". %var% ="))
{
if (!Token::Match(tok->tokAt(-3), "[;{}] %var% ="))
return tok;
const unsigned int varid2 = tok->tokAt(-2)->varId();
if (varid2)
{
const Token *tok2 = Token::findmatch(tokens, "%varid%", varid2);
if (tok2 && !Token::simpleMatch(tok2->previous(), "*"))
return tok;
}
}
}
if (pointer && Token::simpleMatch(tok->next(), "."))
return tok;
if (array && Token::simpleMatch(tok->next(), "["))
{
init = true;
return 0;
}
}
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}
return 0;
}
void CheckOther::uninitvar()
{
// start of function..
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const Token *tok = _tokenizer->tokens();
while (0 != (tok = Token::findmatch(tok, ") const| {")))
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{
// Scan through this scope and check all variables..
unsigned int indentlevel = 0;
for (; tok; tok = tok->next())
{
if (tok->str() == "{")
++indentlevel;
else if (tok->str() == "}")
{
if (indentlevel <= 1)
break;
--indentlevel;
}
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if (Token::Match(tok, "[{};] %var% = malloc|kmalloc (") ||
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Token::Match(tok, "[{};] %var% = new char ["))
{
// check that the variable id is non-zero
const unsigned int varid = tok->next()->varId();
if (varid == 0)
continue;
// goto ')'
tok = tok->tokAt(4);
if (tok->str() == "(")
tok = tok->link();
if (!tok)
break;
// check if data is accessed uninitialized..
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next())
{
if (tok2->str() == "{" || tok2->str() == "}")
break;
if (tok2->varId() == varid)
break;
if (Token::Match(tok2, "strcat|strncat|strlen ( %varid%", varid))
uninitdataError(tok2, tok2->strAt(2));
}
}
else if (Token::Match(tok, "[{};] %type% *| %var% [;[]"))
{
if (Token::Match(tok->next(), "return|goto"))
continue;
// if it's a pointer, dereferencing is forbidden
const bool pointer(tok->strAt(2) == std::string("*"));
// classes are initialized by their constructors
if (!pointer && !tok->next()->isStandardType())
continue;
// goto the variable
tok = tok->tokAt(2);
if (tok->str() == "*")
tok = tok->next();
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// check that the variable id is non-zero
if (tok->varId() == 0)
continue;
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// Is it an array?
const bool array(tok->next()->str() == "[");
if (array)
{
// is the array initialized?
if (Token::simpleMatch(tok->next(), "[ ] =") ||
Token::Match(tok->next(), "[ %any% ] ="))
continue;
}
// check if variable is accessed uninitialized..
bool init = false;
const Token *tokerr = uninitvar_checkscope(_tokenizer->tokens(), tok->next(), tok->varId(), init, pointer, array);
if (tokerr)
uninitvarError(tokerr, tok->str());
}
}
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}
}
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)
{
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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::postIncrement()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
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if (Token::simpleMatch(tok, "for ("))
{
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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)));
break;
}
}
}
}
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void CheckOther::cstyleCastError(const Token *tok)
{
reportError(tok, Severity::style, "cstyleCast", "C-style pointer casting");
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}
void CheckOther::redundantIfDelete0Error(const Token *tok)
{
reportError(tok, Severity::style, "redundantIfDelete0", "Redundant condition. It is safe to deallocate a NULL pointer");
2009-03-21 17:58:13 +01:00
}
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");
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}
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");
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}
void CheckOther::sprintfOverlappingDataError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "sprintfOverlappingData", "Overlapping data buffer " + varname + "\nWhen using sprintf the same buffer must not be used both for output and input. The behaviour is undefined when that happens.\nFor example: 'sprintf(str,\"<%s>\",str);'");
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}
void CheckOther::udivError(const Token *tok)
{
reportError(tok, Severity::error, "udivError", "Unsigned division. The result will be wrong.");
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}
void CheckOther::udivWarning(const Token *tok)
{
reportError(tok, Severity::possibleStyle, "udivWarning", "Division with signed and unsigned operators");
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}
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");
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}
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.");
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}
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");
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}
void CheckOther::charArrayIndexError(const Token *tok)
{
reportError(tok, Severity::style, "charArrayIndex", "Warning - using char variable as array index");
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}
void CheckOther::charBitOpError(const Token *tok)
{
reportError(tok, Severity::style, "charBitOp", "Warning - using char variable in bit operation");
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}
void CheckOther::variableScopeError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::style, "variableScope", "The scope of the variable " + varname + " can be limited");
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}
void CheckOther::conditionAlwaysTrueFalse(const Token *tok, const std::string &truefalse)
{
reportError(tok, Severity::style, "conditionAlwaysTrueFalse", "Condition is always " + truefalse);
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}
void CheckOther::strPlusChar(const Token *tok)
{
reportError(tok, Severity::error, "strPlusChar", "Unusual pointer arithmetic");
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}
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::uninitdataError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "uninitdata", "Data is allocated but not initialized: " + varname);
}
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void CheckOther::uninitvarError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "uninitvar", "Uninitialized variable: " + varname);
}
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void CheckOther::zerodivError(const Token *tok)
{
reportError(tok, Severity::error, "zerodiv", "Division by zero");
}
void CheckOther::postIncrementError(const Token *tok, const std::string &var_name, const bool isIncrement)
{
std::string type = (isIncrement ? "Incrementing" : "Decrementing");
reportError(tok, Severity::possibleStyle, "postIncrementDecrement", ("Pre-" + type + " variable '" + var_name + "' is preferred to Post-" + type));
}