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cppcheck/lib/checkother.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2012 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
#include "checkother.h"
#include "mathlib.h"
#include "symboldatabase.h"
#include <cctype>
#include <cmath> // fabs()
#include <stack>
#include <algorithm> // find_if()
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
namespace {
CheckOther instance;
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkIncrementBoolean()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "%var% ++")) {
if (tok->varId()) {
const Variable *var = symbolDatabase->getVariableFromVarId(tok->varId());
if (var && var->typeEndToken()->str() == "bool")
incrementBooleanError(tok);
}
}
}
}
void CheckOther::incrementBooleanError(const Token *tok)
{
reportError(
tok,
Severity::style,
"incrementboolean",
"The use of a variable of type bool with the ++ postfix operator is always true and deprecated by the C++ Standard.\n"
"The operand of a postfix increment operator may be of type bool but it is deprecated by C++ Standard (Annex D-1) and the operand is always set to true."
);
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::clarifyCalculation()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (tok->str() == "?" && tok->previous()) {
// condition
const Token *cond = tok->previous();
if (cond->isName() || cond->isNumber())
cond = cond->previous();
else if (cond->str() == ")")
cond = cond->link()->previous();
else
continue;
if (cond && cond->str() == "!")
cond = cond->previous();
if (!cond)
continue;
// calculation
if (!cond->isArithmeticalOp())
continue;
const std::string &op = cond->str();
cond = cond->previous();
// skip previous multiplications..
while (cond && cond->previous()) {
if ((cond->isName() || cond->isNumber()) && cond->previous()->str() == "*")
cond = cond->tokAt(-2);
else if (cond->str() == ")")
cond = cond->link()->previous();
else
break;
}
if (!cond)
continue;
// first multiplication operand
if (cond->str() == ")") {
clarifyCalculationError(cond, op);
} else if (cond->isName() || cond->isNumber()) {
if (Token::Match(cond->previous(),("return|=|+|-|,|(|"+op).c_str()))
clarifyCalculationError(cond, op);
}
}
}
}
void CheckOther::clarifyCalculationError(const Token *tok, const std::string &op)
{
// suspicious calculation
const std::string calc("'a" + op + "b?c:d'");
// recommended calculation #1
const std::string s1("'(a" + op + "b)?c:d'");
// recommended calculation #2
const std::string s2("'a" + op + "(b?c:d)'");
reportError(tok,
Severity::style,
"clarifyCalculation",
"Clarify calculation precedence for " + op + " and ?\n"
"Suspicious calculation. Please use parentheses to clarify the code. "
"The code " + calc + " should be written as either " + s1 + " or " + s2 + ".");
}
//---------------------------------------------------------------------------
// Clarify condition '(x = a < 0)' into '((x = a) < 0)' or '(x = (a < 0))'
// Clarify condition '(a & b == c)' into '((a & b) == c)' or '(a & (b == c))'
//---------------------------------------------------------------------------
void CheckOther::clarifyCondition()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "( %var% [=&|^]")) {
for (const Token *tok2 = tok->tokAt(3); tok2; tok2 = tok2->next()) {
if (tok2->str() == "(" || tok2->str() == "[")
tok2 = tok2->link();
else if (Token::Match(tok2, "<|<=|==|!=|>|>=")) {
// This might be a template
if (!_tokenizer->isC() && Token::Match(tok2->previous(), "%var% <"))
break;
clarifyConditionError(tok, tok->strAt(2) == "=", false);
break;
} else if (!tok2->isName() && !tok2->isNumber() && tok2->str() != ".")
break;
}
}
}
// using boolean result in bitwise operation ! x [&|^]
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "!|<|<=|==|!=|>|>=")) {
const Token *tok2 = tok->next();
// Todo: There are false positives if '(' if encountered. It
// is assumed there is something like '(char *)&..' and therefore
// it bails out.
if (Token::Match(tok2, "(|&"))
continue;
while (tok2 && (tok2->isName() || tok2->isNumber() || Token::Match(tok2,".|(|["))) {
if (Token::Match(tok2, "(|["))
tok2 = tok2->link();
tok2 = tok2->next();
}
if (Token::Match(tok2, "[&|^]")) {
// don't write false positives when templates are used
if (Token::Match(tok, "<|>") && (Token::Match(tok2, "& ,|>") ||
Token::simpleMatch(tok2->previous(), "const &")))
continue;
clarifyConditionError(tok,false,true);
}
}
}
}
void CheckOther::clarifyConditionError(const Token *tok, bool assign, bool boolop)
{
std::string errmsg;
if (assign)
errmsg = "Suspicious condition (assignment+comparison), it can be clarified with parentheses";
else if (boolop)
errmsg = "Boolean result is used in bitwise operation. Clarify expression with parentheses\n"
"Suspicious expression. Boolean result is used in bitwise operation. The ! operator "
"and the comparison operators have higher precedence than bitwise operators. "
"It is recommended that the expression is clarified with parentheses.";
else
errmsg = "Suspicious condition (bitwise operator + comparison), it can be clarified with parentheses\n"
"Suspicious condition. Comparison operators have higher precedence than bitwise operators. Please clarify the condition with parentheses.";
reportError(tok,
Severity::style,
"clarifyCondition",
errmsg);
}
//---------------------------------------------------------------------------
// if (bool & bool) -> if (bool && bool)
// if (bool | bool) -> if (bool || bool)
//---------------------------------------------------------------------------
void CheckOther::checkBitwiseOnBoolean()
{
if (!_settings->isEnabled("style"))
return;
// danmar: this is inconclusive because I don't like that there are
// warnings for calculations. Example: set_flag(a & b);
if (!_settings->inconclusive)
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "(|.|return|&&|%oror% %var% [&|]")) {
if (tok->next()->varId()) {
const Variable *var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(tok->next()->varId());
if (var && (var->typeStartToken() == var->typeEndToken()) &&
var->typeStartToken()->str() == "bool") {
bitwiseOnBooleanError(tok->next(), tok->next()->str(), tok->strAt(2) == "&" ? "&&" : "||");
}
}
}
}
}
void CheckOther::bitwiseOnBooleanError(const Token *tok, const std::string &varname, const std::string &op)
{
reportInconclusiveError(tok, Severity::style, "bitwiseOnBoolean",
"Boolean variable '" + varname + "' is used in bitwise operation. Did you mean " + op + " ?");
}
void CheckOther::checkSuspiciousSemicolon()
{
if (!_settings->inconclusive || !_settings->isEnabled("style"))
return;
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
// Look for "if(); {}", "for(); {}" or "while(); {}"
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type == Scope::eIf || i->type == Scope::eElse || i->type == Scope::eElseIf || i->type == Scope::eWhile || i->type == Scope::eFor) {
const Token *tok = Token::findsimplematch(i->classDef, "(", i->classEnd);
if (!tok)
continue;
const Token *end = tok->link();
// Ensure the semicolon is at the same line number as the if/for/while statement
// and the {..} block follows it without an extra empty line.
if (Token::simpleMatch(end, ") { ; } {") &&
end->linenr() == end->tokAt(2)->linenr()
&& end->linenr()+1 >= end->tokAt(4)->linenr()) {
SuspiciousSemicolonError(tok);
}
}
}
}
void CheckOther::SuspiciousSemicolonError(const Token* tok)
{
reportInconclusiveError(tok, Severity::warning, "suspiciousSemicolon",
"Suspicious use of ; at the end of 'if/for/while' statement.");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::warningOldStylePointerCast()
{
if (!_settings->isEnabled("style")) {
return;
}
if (!_tokenizer->isCPP()) {
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;
unsigned char addToIndex = 0;
if (tok->strAt(1) == "const")
addToIndex = 1;
if (tok->strAt(4 + addToIndex) == "const")
continue;
// Is "type" a class?
const std::string pattern("class " + tok->strAt(1 + addToIndex));
if (!Token::findmatch(_tokenizer->tokens(), pattern.c_str()))
continue;
cstyleCastError(tok);
}
}
void CheckOther::cstyleCastError(const Token *tok)
{
reportError(tok, Severity::style, "cstyleCast", "C-style pointer casting");
}
//---------------------------------------------------------------------------
// fflush(stdin) <- fflush only applies to output streams in ANSI C
//---------------------------------------------------------------------------
void CheckOther::checkFflushOnInputStream()
{
const Token *tok = _tokenizer->tokens();
while (tok && ((tok = Token::findsimplematch(tok, "fflush ( stdin )")) != NULL)) {
fflushOnInputStreamError(tok, tok->strAt(2));
tok = tok->tokAt(4);
}
}
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::checkSizeofForNumericParameter()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "sizeof ( %num% )")
|| Token::Match(tok, "sizeof %num%")
) {
sizeofForNumericParameterError(tok);
}
}
}
void CheckOther::sizeofForNumericParameterError(const Token *tok)
{
reportError(tok, Severity::warning,
"sizeofwithnumericparameter", "Using sizeof with a numeric constant as function "
"argument might not be what you intended.\n"
"It is unusual to use constant value with sizeof. For example, sizeof(10)"
" returns 4 (in 32-bit systems) or 8 (in 64-bit systems) instead of 10. sizeof('A')"
" and sizeof(char) can return different results.");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkSizeofForArrayParameter()
{
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "sizeof ( %var% )") || Token::Match(tok, "sizeof %var%")) {
unsigned short tokIdx = 1;
if (tok->strAt(tokIdx) == "(") {
++tokIdx;
}
if (tok->tokAt(tokIdx)->varId() > 0) {
const Variable *var = symbolDatabase->getVariableFromVarId(tok->tokAt(tokIdx)->varId());
if (var) {
const Token *declTok = var->nameToken();
if (Token::simpleMatch(declTok->next(), "[")) {
declTok = declTok->next()->link();
// multidimensional array
while (Token::simpleMatch(declTok->next(), "[")) {
declTok = declTok->next()->link();
}
if (!(Token::Match(declTok->next(), "= %str%")) && !(Token::simpleMatch(declTok->next(), "= {")) && !(Token::simpleMatch(declTok->next(), ";"))) {
if (Token::simpleMatch(declTok->next(), ",")) {
declTok = declTok->next();
while (!Token::simpleMatch(declTok, ";")) {
if (Token::simpleMatch(declTok, ")")) {
sizeofForArrayParameterError(tok);
break;
}
if (Token::Match(declTok, "(|[|{")) {
declTok = declTok->link();
}
declTok = declTok->next();
}
}
}
if (Token::simpleMatch(declTok->next(), ")")) {
sizeofForArrayParameterError(tok);
}
}
}
}
}
}
}
void CheckOther::sizeofForArrayParameterError(const Token *tok)
{
reportError(tok, Severity::error,
"sizeofwithsilentarraypointer", "Using sizeof for array given as function argument "
"returns the size of pointer.\n"
"Giving array as function parameter and then using sizeof-operator for the array "
"argument. In this case the sizeof-operator returns the size of pointer (in the "
"system). It does not return the size of the whole array in bytes as might be "
"expected. For example, this code:\n"
" int f(char a[100]) {\n"
" return sizeof(a);\n"
" }\n"
" returns 4 (in 32-bit systems) or 8 (in 64-bit systems) instead of 100 (the "
"size of the array in bytes)."
);
}
void CheckOther::checkSizeofForStrncmpSize()
{
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
static const char pattern0[] = "strncmp (";
static const char pattern1[] = "sizeof ( %var% ) )";
static const char pattern2[] = "sizeof %var% )";
// danmar : this is inconclusive in case the size parameter is
// sizeof(char *) by intention.
if (!_settings->inconclusive || !_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, pattern0)) {
const Token *tokVar = tok->tokAt(2);
if (tokVar)
tokVar = tokVar->nextArgument();
if (tokVar)
tokVar = tokVar->nextArgument();
if (Token::Match(tokVar, pattern1) || Token::Match(tokVar, pattern2)) {
tokVar = tokVar->next();
if (tokVar->str() == "(")
tokVar = tokVar->next();
if (tokVar->varId() > 0) {
const Variable *var = symbolDatabase->getVariableFromVarId(tokVar->varId());
if (var && var->isPointer()) {
sizeofForStrncmpError(tokVar);
}
}
}
}
}
}
void CheckOther::sizeofForStrncmpError(const Token *tok)
{
reportInconclusiveError(tok, Severity::warning, "strncmpLen",
"Passing sizeof(pointer) as the last argument to strncmp.\n"
"Passing a pointer to sizeof returns the size of the pointer, not "
"the number of characters pointed to by that pointer. This "
"means that only 4 or 8 (on 64-bit systems) characters are "
"compared, which is probably not what was expected.");
}
//---------------------------------------------------------------------------
// switch (x)
// {
// case 2:
// y = a; // <- this assignment is redundant
// case 3:
// y = b; // <- case 2 falls through and sets y twice
// }
//---------------------------------------------------------------------------
void CheckOther::checkRedundantAssignmentInSwitch()
{
if (!_settings->isEnabled("style"))
return;
const char switchPattern[] = "switch ( %any% ) { case";
const char breakPattern[] = "break|continue|return|exit|goto|throw";
const char functionPattern[] = "%var% (";
// Find the beginning of a switch. E.g.:
// switch (var) { ...
const Token *tok = Token::findmatch(_tokenizer->tokens(), switchPattern);
while (tok) {
// Check the contents of the switch statement
std::map<unsigned int, const Token*> varsAssigned;
std::map<unsigned int, const Token*> stringsCopied;
int indentLevel = 0;
for (const Token *tok2 = tok->tokAt(5); tok2; tok2 = tok2->next()) {
if (tok2->str() == "{") {
// Inside a conditional or loop. Don't mark variable accesses as being redundant. E.g.:
// case 3: b = 1;
// case 4: if (a) { b = 2; } // Doesn't make the b=1 redundant because it's conditional
if (Token::Match(tok2->previous(), ")|else {") && tok2->link()) {
const Token* endOfConditional = tok2->link();
for (const Token* tok3 = tok2; tok3 != endOfConditional; tok3 = tok3->next()) {
if (tok3->varId() != 0) {
varsAssigned.erase(tok3->varId());
stringsCopied.erase(tok3->varId());
} else if (Token::Match(tok3, functionPattern) || Token::Match(tok3, breakPattern)) {
varsAssigned.clear();
if (tok3->str() != "strcpy" && tok3->str() != "strncpy")
stringsCopied.clear();
}
}
tok2 = endOfConditional;
} else
++ indentLevel;
} else if (tok2->str() == "}") {
-- indentLevel;
// End of the switch block
if (indentLevel < 0)
break;
}
// Variable assignment. Report an error if it's assigned to twice before a break. E.g.:
// case 3: b = 1; // <== redundant
// case 4: b = 2;
if (Token::Match(tok2->previous(), ";|{|}|: %var% = %any% ;") && tok2->varId() != 0) {
std::map<unsigned int, const Token*>::iterator i = varsAssigned.find(tok2->varId());
if (i == varsAssigned.end())
varsAssigned[tok2->varId()] = tok2;
else
redundantAssignmentInSwitchError(i->second, i->second->str());
stringsCopied.erase(tok2->varId());
}
// String copy. Report an error if it's copied to twice before a break. E.g.:
// case 3: strcpy(str, "a"); // <== redundant
// case 4: strcpy(str, "b");
else if (Token::Match(tok2->previous(), ";|{|}|: strcpy|strncpy ( %var% ,") && tok2->tokAt(2)->varId() != 0) {
std::map<unsigned int, const Token*>::iterator i = stringsCopied.find(tok2->tokAt(2)->varId());
if (i == stringsCopied.end())
stringsCopied[tok2->tokAt(2)->varId()] = tok2->tokAt(2);
else
redundantStrcpyInSwitchError(i->second, i->second->str());
}
// Not a simple assignment so there may be good reason if this variable is assigned to twice. E.g.:
// case 3: b = 1;
// case 4: b++;
else if (tok2->varId() != 0)
varsAssigned.erase(tok2->varId());
// Reset our record of assignments if there is a break or function call. E.g.:
// case 3: b = 1; break;
if (Token::Match(tok2, functionPattern) || Token::Match(tok2, breakPattern)) {
varsAssigned.clear();
if (tok2->str() != "strcpy" && tok2->str() != "strncpy")
stringsCopied.clear();
}
}
tok = Token::findmatch(tok->next(), switchPattern);
}
}
void CheckOther::redundantAssignmentInSwitchError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::warning,
"redundantAssignInSwitch", "Redundant assignment of \"" + varname + "\" in switch");
}
void CheckOther::redundantStrcpyInSwitchError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::warning,
"redundantStrcpyInSwitch",
"Switch case fall-through. Redundant strcpy of \"" + varname + "\".\n"
"Switch case fall-through. Redundant strcpy of \"" + varname + "\". The string is overwritten in a later case block.");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkSwitchCaseFallThrough()
{
if (!(_settings->isEnabled("style") && _settings->experimental))
return;
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
const char breakPattern[] = "break|continue|return|exit|goto|throw";
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type != Scope::eSwitch || !i->classStart) // Find the beginning of a switch
continue;
// Check the contents of the switch statement
std::stack<std::pair<Token *, bool> > ifnest;
std::stack<Token *> loopnest;
std::stack<Token *> scopenest;
bool justbreak = true;
bool firstcase = true;
for (const Token *tok2 = i->classStart; tok2 != i->classEnd; tok2 = tok2->next()) {
if (Token::simpleMatch(tok2, "if (")) {
tok2 = tok2->next()->link()->next();
if (tok2->link() == NULL) {
std::ostringstream errmsg;
errmsg << "unmatched if in switch: " << tok2->linenr();
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
break;
}
ifnest.push(std::make_pair(tok2->link(), false));
justbreak = false;
} else if (Token::simpleMatch(tok2, "while (")) {
tok2 = tok2->next()->link()->next();
// skip over "do { } while ( ) ;" case
if (tok2->str() == "{") {
if (tok2->link() == NULL) {
std::ostringstream errmsg;
errmsg << "unmatched while in switch: " << tok2->linenr();
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
break;
}
loopnest.push(tok2->link());
}
justbreak = false;
} else if (Token::simpleMatch(tok2, "do {")) {
tok2 = tok2->next();
if (tok2->link() == NULL) {
std::ostringstream errmsg;
errmsg << "unmatched do in switch: " << tok2->linenr();
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
break;
}
loopnest.push(tok2->link());
justbreak = false;
} else if (Token::simpleMatch(tok2, "for (")) {
tok2 = tok2->next()->link()->next();
if (tok2->link() == NULL) {
std::ostringstream errmsg;
errmsg << "unmatched for in switch: " << tok2->linenr();
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
break;
}
loopnest.push(tok2->link());
justbreak = false;
} else if (Token::simpleMatch(tok2, "switch (")) {
// skip over nested switch, we'll come to that soon
tok2 = tok2->next()->link()->next()->link();
} else if (Token::Match(tok2, breakPattern)) {
if (loopnest.empty()) {
justbreak = true;
}
tok2 = Token::findsimplematch(tok2, ";");
} else if (Token::Match(tok2, "case|default")) {
if (!justbreak && !firstcase) {
switchCaseFallThrough(tok2);
}
tok2 = Token::findsimplematch(tok2, ":");
justbreak = true;
firstcase = false;
} else if (tok2->str() == "{") {
scopenest.push(tok2->link());
} else if (tok2->str() == "}") {
if (!ifnest.empty() && tok2 == ifnest.top().first) {
if (tok2->next()->str() == "else") {
tok2 = tok2->tokAt(2);
ifnest.pop();
if (tok2->link() == NULL) {
std::ostringstream errmsg;
errmsg << "unmatched if in switch: " << tok2->linenr();
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
break;
}
ifnest.push(std::make_pair(tok2->link(), justbreak));
justbreak = false;
} else {
justbreak &= ifnest.top().second;
ifnest.pop();
}
} else if (!loopnest.empty() && tok2 == loopnest.top()) {
loopnest.pop();
} else if (!scopenest.empty() && tok2 == scopenest.top()) {
scopenest.pop();
} else {
if (!ifnest.empty() || !loopnest.empty() || !scopenest.empty()) {
std::ostringstream errmsg;
errmsg << "unexpected end of switch: ";
errmsg << "ifnest=" << ifnest.size();
if (!ifnest.empty())
errmsg << "," << ifnest.top().first->linenr();
errmsg << ", loopnest=" << loopnest.size();
if (!loopnest.empty())
errmsg << "," << loopnest.top()->linenr();
errmsg << ", scopenest=" << scopenest.size();
if (!scopenest.empty())
errmsg << "," << scopenest.top()->linenr();
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
}
// end of switch block
break;
}
} else if (tok2->str() != ";") {
justbreak = false;
}
}
}
}
void CheckOther::switchCaseFallThrough(const Token *tok)
{
reportError(tok, Severity::style,
"switchCaseFallThrough", "Switch falls through case without comment");
}
//---------------------------------------------------------------------------
// std::cout << std::cout;
//---------------------------------------------------------------------------
void CheckOther::checkCoutCerrMisusage()
{
bool firstCout = false;
unsigned int roundbraces = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (tok->str() == "(")
++roundbraces;
else if (tok->str() == ")") {
if (!roundbraces)
break;
--roundbraces;
}
if (roundbraces)
continue;
if (Token::Match(tok, "std :: cout|cerr")) {
if (firstCout && tok->strAt(-1) == "<<" && tok->strAt(3) != ".") {
coutCerrMisusageError(tok, tok->strAt(2));
firstCout = false;
} else if (tok->strAt(3) == "<<")
firstCout = true;
} else if (firstCout && tok->str() == ";")
firstCout = false;
}
}
void CheckOther::coutCerrMisusageError(const Token* tok, const std::string& streamName)
{
reportError(tok, Severity::error, "coutCerrMisusage", "Invalid usage of output stream: '<< std::" + streamName + "'.");
}
//---------------------------------------------------------------------------
// int x = 1;
// x = x; // <- redundant assignment to self
//
// int y = y; // <- redundant initialization to self
//---------------------------------------------------------------------------
static bool isPOD(const Variable* var)
{
// TODO: Implement real support for POD definition
return(var && var->nameToken()->previous()->isStandardType());
}
void CheckOther::checkSelfAssignment()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
const char selfAssignmentPattern[] = "%var% = %var% ;|=|)";
const Token *tok = Token::findmatch(_tokenizer->tokens(), selfAssignmentPattern);
while (tok) {
if (Token::Match(tok->previous(), "[;{}]") &&
tok->varId() && tok->varId() == tok->tokAt(2)->varId() &&
isPOD(symbolDatabase->getVariableFromVarId(tok->varId()))) {
bool err = true;
// no false positive for 'x = x ? x : 1;'
// it is simplified to 'if (x) { x=x; } else { x=1; }'. The simplification
// always write all tokens on 1 line (even if the statement is several lines), so
// check if the linenr is the same for all the tokens.
if (Token::Match(tok->tokAt(-2), ") { %var% = %var% ; } else { %varid% =", tok->varId())) {
// Find the 'if' token
const Token *tokif = tok->linkAt(-2)->previous();
// find the '}' that terminates the 'else'-block
const Token *else_end = tok->linkAt(6);
if (tokif && else_end && tokif->linenr() == else_end->linenr())
err = false;
}
if (err)
selfAssignmentError(tok, tok->str());
}
tok = Token::findmatch(tok->next(), selfAssignmentPattern);
}
}
void CheckOther::selfAssignmentError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::warning,
"selfAssignment", "Redundant assignment of \"" + varname + "\" to itself");
}
//---------------------------------------------------------------------------
// int a = 1;
// assert(a = 2); // <- assert should not have a side-effect
//---------------------------------------------------------------------------
void CheckOther::checkAssignmentInAssert()
{
if (!_settings->isEnabled("style"))
return;
const char assertPattern[] = "assert ( %any%";
const Token *tok = Token::findmatch(_tokenizer->tokens(), assertPattern);
const Token *endTok = tok ? tok->next()->link() : NULL;
while (tok && endTok) {
for (tok = tok->tokAt(2); tok != endTok; tok = tok->next()) {
if (tok->isName() && (tok->next()->isAssignmentOp() || tok->next()->str() == "++" || tok->next()->str() == "--"))
assignmentInAssertError(tok, tok->str());
else if (Token::Match(tok, "--|++ %var%"))
assignmentInAssertError(tok, tok->strAt(1));
}
tok = Token::findmatch(endTok->next(), assertPattern);
endTok = tok ? tok->next()->link() : NULL;
}
}
void CheckOther::assignmentInAssertError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::warning,
"assignmentInAssert", "Assert statement modifies '" + varname + "'.\n"
"Variable '" + varname + "' is modified insert assert statement. "
"Assert statements are removed from release builds so the code inside "
"assert statement is not run. If the code is needed also in release "
"builds this is a bug.");
}
//---------------------------------------------------------------------------
// if ((x != 1) || (x != 3)) // expression always true
// if ((x == 1) && (x == 3)) // expression always false
// if ((x < 1) && (x > 3)) // expression always false
// if ((x > 3) || (x < 10)) // expression always true
// if ((x > 5) && (x != 1)) // second comparison always true
//
// Check for suspect logic for an expression consisting of 2 comparison
// expressions with a shared variable and constants and a logical operator
// between them.
//
// Suggest a different logical operator when the logical operator between
// the comparisons is probably wrong.
//
// Inform that second comparison is always true when first comparison is true.
//---------------------------------------------------------------------------
void CheckOther::checkIncorrectLogicOperator()
{
if (!_settings->isEnabled("style"))
return;
const char conditionPattern[] = "if|while (";
const Token *tok = Token::findmatch(_tokenizer->tokens(), conditionPattern);
const Token *endTok = tok ? tok->next()->link() : NULL;
while (tok && endTok) {
// Find a pair of comparison expressions with or without parenthesis
// with a shared variable and constants and with a logical operator between them.
// e.g. if (x != 3 || x != 4)
const Token *logicTok = NULL, *term1Tok = NULL, *term2Tok = NULL;
const Token *op1Tok = NULL, *op2Tok = NULL, *op3Tok = NULL, *nextTok = NULL;
if (NULL != (logicTok = Token::findmatch(tok, "( %any% !=|==|<|>|>=|<= %any% ) &&|%oror% ( %any% !=|==|<|>|>=|<= %any% ) %any%", endTok))) {
term1Tok = logicTok->next();
term2Tok = logicTok->tokAt(7);
op1Tok = logicTok->tokAt(2);
op2Tok = logicTok->tokAt(5);
op3Tok = logicTok->tokAt(8);
nextTok = logicTok->tokAt(11);
} else if (NULL != (logicTok = Token::findmatch(tok, "%any% !=|==|<|>|>=|<= %any% &&|%oror% %any% !=|==|<|>|>=|<= %any% %any%", endTok))) {
term1Tok = logicTok;
term2Tok = logicTok->tokAt(4);
op1Tok = logicTok->next();
op2Tok = logicTok->tokAt(3);
op3Tok = logicTok->tokAt(5);
nextTok = logicTok->tokAt(7);
}
if (logicTok) {
// Find the common variable and the two different-valued constants
unsigned int variableTested = 0;
std::string firstConstant, secondConstant;
bool varFirst1, varFirst2;
unsigned int varId;
const Token *varTok = NULL;
if (Token::Match(term1Tok, "%var% %any% %num%")) {
varTok = term1Tok;
varId = varTok->varId();
if (!varId) {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
varFirst1 = true;
firstConstant = term1Tok->strAt(2);
} else if (Token::Match(term1Tok, "%num% %any% %var%")) {
varTok = term1Tok->tokAt(2);
varId = varTok->varId();
if (!varId) {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
varFirst1 = false;
firstConstant = term1Tok->str();
} else {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
if (Token::Match(term2Tok, "%var% %any% %num%")) {
const unsigned int varId2 = term2Tok->varId();
if (!varId2 || varId != varId2) {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
varFirst2 = true;
secondConstant = term2Tok->strAt(2);
variableTested = varId;
} else if (Token::Match(term2Tok, "%num% %any% %var%")) {
const unsigned int varId2 = term1Tok->tokAt(2)->varId();
if (!varId2 || varId != varId2) {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
varFirst2 = false;
secondConstant = term2Tok->str();
variableTested = varId;
} else {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
if (variableTested == 0 || firstConstant.empty() || secondConstant.empty()) {
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
continue;
}
enum Position { First, Second, NA };
enum Relation { Equal, NotEqual, Less, LessEqual, More, MoreEqual };
enum LogicError { Exclusion, AlwaysTrue, AlwaysFalse, AlwaysFalseOr };
static const struct Condition {
const char *before;
Position position1;
const char *op1TokStr;
const char *op2TokStr;
Position position2;
const char *op3TokStr;
const char *after;
Relation relation;
LogicError error;
} conditions[] = {
{ "!!&&", NA, "!=", "||", NA, "!=", "!!&&", NotEqual, Exclusion }, // (x != 1) || (x != 3) <- always true
{ "(", NA, "==", "&&", NA, "==", ")", NotEqual, AlwaysFalseOr }, // (x == 1) && (x == 3) <- always false
{ "(", First, "<", "&&", First, ">", ")", LessEqual, AlwaysFalseOr }, // (x < 1) && (x > 3) <- always false
{ "(", First, ">", "&&", First, "<", ")", MoreEqual, AlwaysFalseOr }, // (x > 3) && (x < 1) <- always false
{ "(", Second, ">", "&&", First, ">", ")", LessEqual, AlwaysFalseOr }, // (1 > x) && (x > 3) <- always false
{ "(", First, ">", "&&", Second, ">", ")", MoreEqual, AlwaysFalseOr }, // (x > 3) && (1 > x) <- always false
{ "(", First, "<", "&&", Second, "<", ")", LessEqual, AlwaysFalseOr }, // (x < 1) && (3 < x) <- always false
{ "(", Second, "<", "&&", First, "<", ")", MoreEqual, AlwaysFalseOr }, // (3 < x) && (x < 1) <- always false
{ "(", Second, ">", "&&", Second, "<", ")", LessEqual, AlwaysFalseOr }, // (1 > x) && (3 < x) <- always false
{ "(", Second, "<", "&&", Second, ">", ")", MoreEqual, AlwaysFalseOr }, // (3 < x) && (1 > x) <- always false
{ "(", First , ">|>=", "||", First, "<|<=", ")", Less, Exclusion }, // (x > 3) || (x < 10) <- always true
{ "(", First , "<|<=", "||", First, ">|>=", ")", More, Exclusion }, // (x < 10) || (x > 3) <- always true
{ "(", Second, "<|<=", "||", First, "<|<=", ")", Less, Exclusion }, // (3 < x) || (x < 10) <- always true
{ "(", First, "<|<=", "||", Second, "<|<=", ")", More, Exclusion }, // (x < 10) || (3 < x) <- always true
{ "(", First, ">|>=", "||", Second, ">|>=", ")", Less, Exclusion }, // (x > 3) || (10 > x) <- always true
{ "(", Second, ">|>=", "||", First, ">|>=", ")", More, Exclusion }, // (10 > x) || (x > 3) <- always true
{ "(", Second, "<|<=", "||", Second, ">|<=", ")", Less, Exclusion }, // (3 < x) || (10 > x) <- always true
{ "(", Second, ">|>=", "||", Second, "<|<=", ")", More, Exclusion }, // (10 > x) || (3 < x) <- always true
{ "(", First, ">", "&&", NA, "!=", ")", More, AlwaysTrue }, // (x > 5) && (x != 1) <- second expression always true
{ "(", Second, "<", "&&", NA, "!=", ")", More, AlwaysTrue }, // (5 < x) && (x != 1) <- second expression always true
{ "(", First, ">", "&&", NA, "==", ")", More, AlwaysFalse }, // (x > 5) && (x == 1) <- second expression always false
{ "(", Second, "<", "&&", NA, "==", ")", More, AlwaysFalse }, // (5 < x) && (x == 1) <- second expression always false
};
for (unsigned int i = 0; i < (sizeof(conditions) / sizeof(conditions[0])); i++) {
if (!((conditions[i].position1 == NA) || (((conditions[i].position1 == First) && varFirst1) || ((conditions[i].position1 == Second) && !varFirst1))))
continue;
if (!((conditions[i].position2 == NA) || (((conditions[i].position2 == First) && varFirst2) || ((conditions[i].position2 == Second) && !varFirst2))))
continue;
if (!Token::Match(op1Tok, conditions[i].op1TokStr))
continue;
if (!Token::Match(op2Tok, conditions[i].op2TokStr))
continue;
if (!Token::Match(op3Tok, conditions[i].op3TokStr))
continue;
if (!Token::Match(logicTok->previous(), conditions[i].before))
continue;
if (!Token::Match(nextTok, conditions[i].after))
continue;
if ((conditions[i].relation == Equal && MathLib::isEqual(firstConstant, secondConstant)) ||
(conditions[i].relation == NotEqual && MathLib::isNotEqual(firstConstant, secondConstant)) ||
(conditions[i].relation == Less && MathLib::isLess(firstConstant, secondConstant)) ||
(conditions[i].relation == LessEqual && MathLib::isLessEqual(firstConstant, secondConstant)) ||
(conditions[i].relation == More && MathLib::isGreater(firstConstant, secondConstant)) ||
(conditions[i].relation == MoreEqual && MathLib::isGreaterEqual(firstConstant, secondConstant))) {
if (conditions[i].error == Exclusion || conditions[i].error == AlwaysFalseOr)
incorrectLogicOperatorError(term1Tok, conditions[i].error == Exclusion);
else {
std::string text("When " + varTok->str() + " is greater than " + firstConstant + ", the comparison " +
varTok->str() + " " + conditions[i].op3TokStr + " " + secondConstant +
" is always " + (conditions[i].error == AlwaysTrue ? "true." : "false."));
secondAlwaysTrueFalseWhenFirstTrueError(term1Tok, text);
}
}
}
}
tok = Token::findmatch(endTok->next(), conditionPattern);
endTok = tok ? tok->next()->link() : NULL;
}
}
void CheckOther::incorrectLogicOperatorError(const Token *tok, bool always)
{
if (always)
reportError(tok, Severity::warning,
"incorrectLogicOperator", "Mutual exclusion over || always evaluates to true. Did you intend to use && instead?");
else
reportError(tok, Severity::warning,
"incorrectLogicOperator", "Expression always evaluates to false. Did you intend to use || instead?");
}
void CheckOther::secondAlwaysTrueFalseWhenFirstTrueError(const Token *tok, const std::string &truefalse)
{
reportError(tok, Severity::style, "secondAlwaysTrueFalseWhenFirstTrue", truefalse);
}
//---------------------------------------------------------------------------
// try {} catch (std::exception err) {} <- Should be "std::exception& err"
//---------------------------------------------------------------------------
void CheckOther::checkCatchExceptionByValue()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type != Scope::eCatch)
continue;
// Find a pass-by-value declaration in the catch(), excluding basic types
// e.g. catch (std::exception err)
const Variable* var = symbolDatabase->getVariableFromVarId(i->classStart->tokAt(-2)->varId());
if (var && var->isClass() && !var->isPointer() && !var->isReference())
catchExceptionByValueError(i->classDef);
}
}
void CheckOther::catchExceptionByValueError(const Token *tok)
{
reportError(tok, Severity::style,
"catchExceptionByValue", "Exception should be caught by reference.\n"
"The exception is caught as a value. It could be caught "
"as a (const) reference which is usually recommended in C++.");
}
//---------------------------------------------------------------------------
// 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 (!Token::Match(tok, "strtol|strtoul ("))
continue;
// Locate the third parameter of the function call..
unsigned int param = 1;
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
if (tok2->str() == "(")
tok2 = tok2->link();
else if (tok2->str() == ")")
break;
else if (tok2->str() == ",") {
++param;
if (param == 3) {
if (Token::Match(tok2, ", %num% )")) {
const MathLib::bigint 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->str() != ",")
tok2 = tok2->next();
tok2 = tok2->next(); // Jump behind ","
if (tok->str() == "snprintf") { // Jump over second parameter for snprintf
tok2 = tok2->nextArgument();
if (!tok2)
continue;
}
// is any source buffer overlapping the target buffer?
do {
if (Token::Match(tok2, "%varid% [,)]", varid)) {
sprintfOverlappingDataError(tok2->next(), tok2->next()->str());
break;
}
} while (NULL != (tok2 = tok2->nextArgument()));
}
}
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 behavior: variable is used as parameter and destination in s[n]printf().\n"
"The variable '" + varname + "' is used both as a parameter and as a destination in "
"s[n]printf(). The origin and destination buffers overlap. Quote from glibc (C-library) "
"documentation (http://www.gnu.org/software/libc/manual/html_mono/libc.html#Formatted-Output-Functions): "
"'If copying takes place between objects that overlap as a result of a call "
"to sprintf() or snprintf(), the results are undefined.'");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::invalidScanf()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
const Token *formatToken = 0;
if (Token::Match(tok, "scanf|vscanf ( %str% ,"))
formatToken = tok->tokAt(2);
else if (Token::Match(tok, "sscanf|vsscanf|fscanf|vfscanf (")) {
const Token* nextArg = tok->tokAt(2)->nextArgument();
if (nextArg && Token::Match(nextArg, "%str%"))
formatToken = nextArg;
else
continue;
} else
continue;
bool format = false;
// scan the string backwards, so we dont need to keep states
const std::string &formatstr(formatToken->str());
for (unsigned int i = 1; i < formatstr.length(); i++) {
if (formatstr[i] == '%')
format = !format;
else if (!format)
continue;
else if (std::isdigit(formatstr[i])) {
format = false;
}
else if (std::isalpha(formatstr[i])) {
if (formatstr[i] != 'c') // #3490 - field width limits are not necessary for %c
invalidScanfError(tok);
format = false;
}
}
}
}
void CheckOther::invalidScanfError(const Token *tok)
{
reportError(tok, Severity::warning,
"invalidscanf", "scanf without field width limits can crash with huge input data\n"
"scanf without field width limits can crash with huge input data. To fix this error "
"message add a field width specifier:\n"
" %s => %20s\n"
" %i => %3i\n"
"\n"
"Sample program that can crash:\n"
"\n"
"#include <stdio.h>\n"
"int main()\n"
"{\n"
" int a;\n"
" scanf(\"%i\", &a);\n"
" return 0;\n"
"}\n"
"\n"
"To make it crash:\n"
"perl -e 'print \"5\"x2100000' | ./a.out");
}
//---------------------------------------------------------------------------
// printf("%u", "xyz"); // Wrong argument type
// printf("%u%s", 1); // Too few arguments
// printf("", 1); // Too much arguments
//---------------------------------------------------------------------------
static bool isComplexType(const Variable* var, const Token* varTypeTok)
{
if (var->type())
return(true);
static std::set<std::string> knownTypes;
if (knownTypes.empty()) {
knownTypes.insert("struct"); // If a type starts with the struct keyword, its a complex type
knownTypes.insert("string");
}
if (varTypeTok->str() == "std")
varTypeTok = varTypeTok->tokAt(2);
return(knownTypes.find(varTypeTok->str()) != knownTypes.end() && !var->isPointer() && !var->isArray());
}
static bool isKnownType(const Variable* var, const Token* varTypeTok)
{
return(varTypeTok->isStandardType() || varTypeTok->next()->isStandardType() || isComplexType(var, varTypeTok));
}
void CheckOther::checkWrongPrintfScanfArguments()
{
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (!tok->isName()) continue;
const Token* argListTok = 0; // Points to first va_list argument
std::string formatString;
if (Token::Match(tok, "printf|scanf ( %str%")) {
formatString = tok->strAt(2);
if (tok->strAt(3) == ",") {
argListTok = tok->tokAt(4);
} else if (tok->strAt(3) == ")") {
argListTok = 0;
} else {
continue;
}
} else if (Token::Match(tok, "sprintf|fprintf|sscanf|fscanf ( %any%")) {
const Token* formatStringTok = tok->tokAt(2)->nextArgument(); // Find second parameter (format string)
if (Token::Match(formatStringTok, "%str% ,")) {
argListTok = formatStringTok->nextArgument(); // Find third parameter (first argument of va_args)
formatString = formatStringTok->str();
} else if (Token::Match(formatStringTok, "%str% )")) {
argListTok = 0; // Find third parameter (first argument of va_args)
formatString = formatStringTok->str();
} else {
continue;
}
} else if (Token::Match(tok, "snprintf|fnprintf ( %any%")) {
const Token* formatStringTok = tok->tokAt(2);
for (int i = 0; i < 2 && formatStringTok; i++) {
formatStringTok = formatStringTok->nextArgument(); // Find third parameter (format string)
}
if (Token::Match(formatStringTok, "%str% ,")) {
argListTok = formatStringTok->nextArgument(); // Find fourth parameter (first argument of va_args)
formatString = formatStringTok->str();
}
if (Token::Match(formatStringTok, "%str% )")) {
argListTok = 0; // Find fourth parameter (first argument of va_args)
formatString = formatStringTok->str();
} else {
continue;
}
} else {
continue;
}
// Count format string parameters..
bool scan = Token::Match(tok, "sscanf|fscanf|scanf");
unsigned int numFormat = 0;
bool percent = false;
const Token* argListTok2 = argListTok;
for (std::string::iterator i = formatString.begin(); i != formatString.end(); ++i) {
if (*i == '%') {
percent = !percent;
} else if (percent && *i == '[') {
while (i != formatString.end()) {
if (*i == ']') {
numFormat++;
if (argListTok)
argListTok = argListTok->nextArgument();
percent = false;
break;
}
++i;
}
if (i == formatString.end())
break;
} else if (percent) {
percent = false;
bool _continue = false;
while (i != formatString.end() && *i != ']' && !std::isalpha(*i)) {
if (*i == '*') {
if (scan)
_continue = true;
else {
numFormat++;
if (argListTok)
argListTok = argListTok->nextArgument();
}
}
++i;
}
if (i == formatString.end())
break;
if (_continue)
continue;
if (scan || *i != 'm') { // %m is a non-standard extension that requires no parameter on print functions.
numFormat++;
// Perform type checks
if (_settings->isEnabled("style") && Token::Match(argListTok, "%any% ,|)")) { // We can currently only check the type of arguments matching this simple pattern.
const Variable* variableInfo = symbolDatabase->getVariableFromVarId(argListTok->varId());
const Token* varTypeTok = variableInfo ? variableInfo->typeStartToken() : NULL;
if (varTypeTok && varTypeTok->str() == "static")
varTypeTok = varTypeTok->next();
if (scan && varTypeTok) {
if ((!variableInfo->isPointer() && !variableInfo->isArray()) || varTypeTok->str() == "const")
invalidScanfArgTypeError(tok, tok->str(), numFormat);
} else if (!scan) {
switch (*i) {
case 's':
if (variableInfo && !Token::Match(argListTok, "%str%") && isKnownType(variableInfo, varTypeTok) && (!variableInfo->isPointer() && !variableInfo->isArray()))
invalidPrintfArgTypeError_s(tok, numFormat);
break;
case 'n':
if ((varTypeTok && isKnownType(variableInfo, varTypeTok) && ((!variableInfo->isPointer() && !variableInfo->isArray()) || varTypeTok->str() == "const")) || Token::Match(argListTok, "%str%"))
invalidPrintfArgTypeError_n(tok, numFormat);
break;
case 'c':
case 'd':
case 'i':
case 'u':
case 'x':
case 'X':
case 'o':
if (varTypeTok && varTypeTok->str() == "const")
varTypeTok = varTypeTok->next();
if ((varTypeTok && isKnownType(variableInfo, varTypeTok) && !Token::Match(varTypeTok, "unsigned|signed| bool|short|long|int|char|size_t|unsigned|signed") && !variableInfo->isPointer() && !variableInfo->isArray()))
invalidPrintfArgTypeError_int(tok, numFormat, *i);
else if (Token::Match(argListTok, "%str%"))
invalidPrintfArgTypeError_int(tok, numFormat, *i);
break;
case 'p':
if (varTypeTok && varTypeTok->str() == "const")
varTypeTok = varTypeTok->next();
if (varTypeTok && isKnownType(variableInfo, varTypeTok) && !Token::Match(varTypeTok, "unsigned|signed| short|long|int|size_t|unsigned|signed") && !variableInfo->isPointer() && !variableInfo->isArray())
invalidPrintfArgTypeError_p(tok, numFormat);
else if (Token::Match(argListTok, "%str%"))
invalidPrintfArgTypeError_p(tok, numFormat);
break;
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
if (varTypeTok && varTypeTok->str() == "const")
varTypeTok = varTypeTok->next();
if (varTypeTok && ((isKnownType(variableInfo, varTypeTok) && !Token::Match(varTypeTok, "float|double")) || variableInfo->isPointer() || variableInfo->isArray()))
invalidPrintfArgTypeError_float(tok, numFormat, *i);
else if (Token::Match(argListTok, "%str%"))
invalidPrintfArgTypeError_float(tok, numFormat, *i);
break;
default:
break;
}
}
}
if (argListTok)
argListTok = argListTok->nextArgument(); // Find next argument
}
}
}
// Count printf/scanf parameters..
unsigned int numFunction = 0;
while (argListTok2) {
numFunction++;
argListTok2 = argListTok2->nextArgument(); // Find next argument
}
// Mismatching number of parameters => warning
if (numFormat != numFunction)
wrongPrintfScanfArgumentsError(tok, tok->str(), numFormat, numFunction);
}
}
void CheckOther::wrongPrintfScanfArgumentsError(const Token* tok,
const std::string &functionName,
unsigned int numFormat,
unsigned int numFunction)
{
Severity::SeverityType severity = numFormat > numFunction ? Severity::error : Severity::warning;
if (severity != Severity::error && !_settings->isEnabled("style"))
return;
std::ostringstream errmsg;
errmsg << functionName
<< " format string has "
<< numFormat
<< " parameters but "
<< (numFormat > numFunction ? "only " : "")
<< numFunction
<< " are given";
reportError(tok, severity, "wrongPrintfScanfArgNum", errmsg.str());
}
void CheckOther::invalidScanfArgTypeError(const Token* tok, const std::string &functionName, unsigned int numFormat)
{
std::ostringstream errmsg;
errmsg << functionName << " argument no. " << numFormat << ": requires non-const pointers or arrays as arguments";
reportError(tok, Severity::warning, "invalidScanfArgType", errmsg.str());
}
void CheckOther::invalidPrintfArgTypeError_s(const Token* tok, unsigned int numFormat)
{
std::ostringstream errmsg;
errmsg << "%s in format string (no. " << numFormat << ") requires a char* given in the argument list";
reportError(tok, Severity::warning, "invalidPrintfArgType_s", errmsg.str());
}
void CheckOther::invalidPrintfArgTypeError_n(const Token* tok, unsigned int numFormat)
{
std::ostringstream errmsg;
errmsg << "%n in format string (no. " << numFormat << ") requires a pointer to an non-const integer given in the argument list";
reportError(tok, Severity::warning, "invalidPrintfArgType_n", errmsg.str());
}
void CheckOther::invalidPrintfArgTypeError_p(const Token* tok, unsigned int numFormat)
{
std::ostringstream errmsg;
errmsg << "%p in format string (no. " << numFormat << ") requires an integer or pointer given in the argument list";
reportError(tok, Severity::warning, "invalidPrintfArgType_p", errmsg.str());
}
void CheckOther::invalidPrintfArgTypeError_int(const Token* tok, unsigned int numFormat, char c)
{
std::ostringstream errmsg;
errmsg << "%" << c << " in format string (no. " << numFormat << ") requires an integer given in the argument list";
reportError(tok, Severity::warning, "invalidPrintfArgType_int", errmsg.str());
}
void CheckOther::invalidPrintfArgTypeError_float(const Token* tok, unsigned int numFormat, char c)
{
std::ostringstream errmsg;
errmsg << "%" << c << " in format string (no. " << numFormat << ") requires a floating point number given in the argument list";
reportError(tok, Severity::warning, "invalidPrintfArgType_float", errmsg.str());
}
//---------------------------------------------------------------------------
// if (!x==3) <- Probably meant to be "x!=3"
//---------------------------------------------------------------------------
void CheckOther::checkComparisonOfBoolWithInt()
{
if (!_settings->isEnabled("style"))
return;
std::map<unsigned int, bool> boolvars; // Contains all declarated standard type variables and indicates whether its a bool or not.
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "[{};(,] %type% %var% [;=,)]") && tok->next()->isStandardType() && tok->tokAt(2)->varId() > 0) { // Declaration of standard type variable
boolvars[tok->tokAt(2)->varId()] = (tok->strAt(1) == "bool");
} else if (Token::Match(tok, "%var% >|>=|==|!=|<=|< %num%")) { // Comparing variable with number
const Token *varTok = tok;
const Token *numTok = tok->tokAt(2);
std::map<unsigned int, bool>::const_iterator iVar = boolvars.find(varTok->varId());
if (iVar != boolvars.end() && iVar->second && // Variable has to be a boolean
((tok->strAt(1) != "==" && tok->strAt(1) != "!=") ||
(MathLib::toLongNumber(numTok->str()) != 0 && MathLib::toLongNumber(numTok->str()) != 1))) { // == 0 and != 0 are allowed, for C also == 1 and != 1
comparisonOfBoolWithIntError(varTok, numTok->str());
}
} else if (Token::Match(tok, "%num% >|>=|==|!=|<=|< %var%")) { // Comparing number with variable
const Token *varTok = tok->tokAt(2);
const Token *numTok = tok;
std::map<unsigned int, bool>::const_iterator iVar = boolvars.find(varTok->varId());
if (iVar != boolvars.end() && iVar->second && // Variable has to be a boolean
((tok->strAt(1) != "==" && tok->strAt(1) != "!=") ||
(MathLib::toLongNumber(numTok->str()) != 0 && MathLib::toLongNumber(numTok->str()) != 1))) { // == 0 and != 0 are allowed, for C also == 1 and != 1
comparisonOfBoolWithIntError(varTok, numTok->str());
}
} else if (Token::Match(tok, "true|false >|>=|==|!=|<=|< %var%")) { // Comparing boolean constant with variable
const Token *varTok = tok->tokAt(2);
const Token *constTok = tok;
std::map<unsigned int, bool>::const_iterator iVar = boolvars.find(varTok->varId());
if (iVar != boolvars.end() && !iVar->second) { // Variable has to be of non-boolean standard type
comparisonOfBoolWithIntError(varTok, constTok->str());
}
} else if (Token::Match(tok, "%var% >|>=|==|!=|<=|< true|false")) { // Comparing variable with boolean constant
const Token *varTok = tok;
const Token *constTok = tok->tokAt(2);
std::map<unsigned int, bool>::const_iterator iVar = boolvars.find(varTok->varId());
if (iVar != boolvars.end() && !iVar->second) { // Variable has to be of non-boolean standard type
comparisonOfBoolWithIntError(varTok, constTok->str());
}
} else if (Token::Match(tok, "%var% >|>=|==|!=|<=|< %var%") &&
!Token::Match(tok->tokAt(3), ".|::|(")) { // Comparing two variables, one of them boolean, one of them integer
const Token *var1Tok = tok->tokAt(2);
const Token *var2Tok = tok;
std::map<unsigned int, bool>::const_iterator iVar1 = boolvars.find(var1Tok->varId());
std::map<unsigned int, bool>::const_iterator iVar2 = boolvars.find(var2Tok->varId());
if (iVar1 != boolvars.end() && iVar2 != boolvars.end()) {
if (iVar1->second && !iVar2->second) // Comparing boolean with non-bool standard type
comparisonOfBoolWithIntError(var2Tok, var1Tok->str());
else if (!iVar1->second && iVar2->second) // Comparing non-bool standard type with boolean
comparisonOfBoolWithIntError(var2Tok, var2Tok->str());
}
} else if (Token::Match(tok, "( ! %var% ==|!= %num% )")) {
const Token *numTok = tok->tokAt(4);
if (numTok && numTok->str() != "0" && numTok->str() != "1") {
comparisonOfBoolWithIntError(numTok, "!"+tok->strAt(2));
}
} else if (Token::Match(tok, "( %num% ==|!= ! %var% )")) {
const Token *numTok = tok->next();
if (numTok && numTok->str() != "0" && numTok->str() != "1") {
comparisonOfBoolWithIntError(numTok, "!"+tok->strAt(4));
}
}
}
}
void CheckOther::comparisonOfBoolWithIntError(const Token *tok, const std::string &expression)
{
reportError(tok, Severity::warning, "comparisonOfBoolWithInt",
"Comparison of a boolean with integer that is neither 1 nor 0\n"
"The expression \"" + expression + "\" is of type 'bool' "
"and it is compared against a integer value that is "
"neither 1 nor 0.");
}
//---------------------------------------------------------------------------
// Find consecutive return, break, continue, goto or throw statements. e.g.:
// break; break;
// Detect dead code, that follows such a statement. e.g.:
// return(0); foo();
//---------------------------------------------------------------------------
void CheckOther::checkUnreachableCode()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
const Token* secondBreak = 0;
const Token* labelName = 0;
if (tok->str() == "(")
tok = tok->link();
else if (Token::Match(tok, "break|continue ;"))
secondBreak = tok->tokAt(2);
else if (Token::Match(tok, "[;{}:] return|throw")) {
tok = tok->next(); // tok should point to return or throw
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next())
if (tok2->str() == ";") {
secondBreak = tok2->next();
break;
}
} else if (Token::Match(tok, "goto %any% ;")) {
secondBreak = tok->tokAt(3);
labelName = tok->tokAt(1);
}
if (secondBreak) {
if (Token::Match(secondBreak, "continue|goto|throw") ||
(secondBreak->str() == "return" && (tok->str() == "return" || secondBreak->strAt(1) == ";"))) { // return with value after statements like throw can be necessary to make a function compile
duplicateBreakError(secondBreak);
tok = Token::findmatch(secondBreak, "[}:]");
} else if (secondBreak->str() == "break") { // break inside switch as second break statement should not issue a warning
if (tok->str() == "break") // If the previous was a break, too: Issue warning
duplicateBreakError(secondBreak);
else {
unsigned int indent = 0;
for (const Token* tok2 = tok; tok2; tok2 = tok2->previous()) { // Check, if the enclosing scope is a switch (TODO: Can we use SymbolDatabase here?)
if (tok2->str() == "}")
indent++;
else if (indent == 0 && tok2->str() == "{" && tok2->strAt(-1) == ")") {
if (tok2->previous()->link()->strAt(-1) != "switch") {
duplicateBreakError(secondBreak);
break;
} else
break;
} else if (tok2->str() == "{")
indent--;
}
}
tok = Token::findmatch(secondBreak, "[}:]");
} else if (!Token::Match(secondBreak, "return|}|case|default") && secondBreak->strAt(1) != ":") { // TODO: No bailout for unconditional scopes
// If the goto label is followed by a loop construct in which the label is defined it's quite likely
// that the goto jump was intended to skip some code on the first loop iteration.
bool labelInFollowingLoop = false;
if (labelName && Token::Match(secondBreak, "while|do|for")) {
const Token *scope = Token::findsimplematch(secondBreak, "{");
if (scope) {
for (const Token *tokIter = scope; tokIter != scope->link() && tokIter; tokIter = tokIter->next()) {
if (Token::Match(tokIter, "[;{}] %any% :") && labelName->str() == tokIter->strAt(1)) {
labelInFollowingLoop = true;
break;
}
}
}
}
if (!labelInFollowingLoop)
unreachableCodeError(secondBreak);
tok = Token::findmatch(secondBreak, "[}:]");
} else
tok = secondBreak;
if (!tok)
break;
}
}
}
void CheckOther::duplicateBreakError(const Token *tok)
{
reportError(tok, Severity::style, "duplicateBreak",
"Consecutive return, break, continue, goto or throw statements are unnecessary.\n"
"The second of the two statements can never be executed, and so should be removed.");
}
void CheckOther::unreachableCodeError(const Token *tok)
{
reportError(tok, Severity::style, "unreachableCode",
"Statements following return, break, continue, goto or throw will never be executed.");
}
//---------------------------------------------------------------------------
// Check for unsigned divisions
//---------------------------------------------------------------------------
static bool isUnsigned(const Variable* var)
{
return(var && var->typeStartToken()->isUnsigned() && !var->isPointer() && !var->isArray());
}
static bool isSigned(const Variable* var)
{
return(var && !var->typeStartToken()->isUnsigned() && Token::Match(var->typeEndToken(), "int|char|short|long") && !var->isPointer() && !var->isArray());
}
void CheckOther::checkUnsignedDivision()
{
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
bool style = _settings->isEnabled("style");
const Token* ifTok = 0;
// Check for "ivar / uvar" and "uvar / ivar"
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "[).]")) // Don't check members or casted variables
continue;
if (Token::Match(tok->next(), "%var% / %num%")) {
if (tok->strAt(3)[0] == '-' && isUnsigned(symbolDatabase->getVariableFromVarId(tok->next()->varId()))) {
udivError(tok->next(), false);
}
} else if (Token::Match(tok->next(), "%num% / %var%")) {
if (tok->strAt(1)[0] == '-' && isUnsigned(symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId()))) {
udivError(tok->next(), false);
}
} else if (Token::Match(tok->next(), "%var% / %var%") && _settings->inconclusive && style && !ifTok) {
const Variable* var1 = symbolDatabase->getVariableFromVarId(tok->next()->varId());
const Variable* var2 = symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId());
if ((isUnsigned(var1) && isSigned(var2)) || (isUnsigned(var2) && isSigned(var1))) {
udivError(tok->next(), true);
}
} else if (!ifTok && Token::Match(tok, "if ("))
ifTok = tok->next()->link()->next()->link();
else if (ifTok == tok)
ifTok = 0;
}
}
void CheckOther::udivError(const Token *tok, bool inconclusive)
{
if (inconclusive)
reportError(tok, Severity::warning, "udivError", "Division with signed and unsigned operators. The result might be wrong.");
else
reportError(tok, Severity::error, "udivError", "Unsigned division. The result will be wrong.");
}
//---------------------------------------------------------------------------
// memset(p, y, 0 /* bytes to fill */) <- 2nd and 3rd arguments inverted
//---------------------------------------------------------------------------
void CheckOther::checkMemsetZeroBytes()
{
if (!_settings->isEnabled("style"))
return;
for (const Token* tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::simpleMatch(tok, "memset (")) {
const Token* lastParamTok = tok->next()->link()->previous();
if (lastParamTok->str() == "0")
memsetZeroBytesError(tok, tok->strAt(2));
}
}
}
void CheckOther::memsetZeroBytesError(const Token *tok, const std::string &varname)
{
const std::string summary("memset() called to fill 0 bytes of \'" + varname + "\'");
const std::string verbose(summary + ". Second and third arguments might be inverted.");
reportError(tok, Severity::warning, "memsetZeroBytes", summary + "\n" + verbose);
}
//---------------------------------------------------------------------------
// Check scope of variables..
//---------------------------------------------------------------------------
void CheckOther::checkVariableScope()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
// Walk through all tokens..
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
// Skip function local class and struct declarations..
if ((tok->str() == "class") || (tok->str() == "struct") || (tok->str() == "union")) {
for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
if (tok2->str() == "{") {
tok = tok2->link();
break;
}
if (Token::Match(tok2, "[,);]")) {
break;
}
}
if (! tok)
break;
}
if (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
unsigned 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() == "{") {
if (tok->strAt(-1) == "=") {
if (Token::findmatch(tok, varname.c_str(), tok->link())) {
return;
}
tok = tok->link();
} else
++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;
}
else if (Token::simpleMatch(tok, "do {"))
for_or_while = true;
// possible unexpanded macro hiding for/while..
else if (tok->str() != "else" && Token::Match(tok->previous(), "[;{}] %type% {")) {
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);
}
void CheckOther::variableScopeError(const Token *tok, const std::string &varname)
{
reportError(tok,
Severity::style,
"variableScope",
"The scope of the variable '" + varname + "' can be reduced\n"
"The scope of the variable '" + varname + "' can be reduced. Warning: It can be unsafe "
"to fix this message. Be careful. Especially when there are inner loops. Here is an "
"example where cppcheck will write that the scope for 'i' can be reduced:\n"
"void f(int x)\n"
"{\n"
" int i = 0;\n"
" if (x) {\n"
" // it's safe to move 'int i = 0' here\n"
" for (int n = 0; n < 10; ++n) {\n"
" // it is possible but not safe to move 'int i = 0' here\n"
" do_something(&i);\n"
" }\n"
" }\n"
"}\n"
"When you see this message it is always safe to reduce the variable scope 1 level.");
}
//---------------------------------------------------------------------------
// Check for constant function parameters
//---------------------------------------------------------------------------
void CheckOther::checkConstantFunctionParameter()
{
if (!_settings->isEnabled("performance"))
return;
const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type == Scope::eFunction && i->function) {
for (const Token* tok = i->function->arg->next(); tok; tok = tok->nextArgument()) {
// TODO: False negatives. This pattern only checks for string.
// Investigate if there are other classes in the std
// namespace and add them to the pattern. There are
// streams for example (however it seems strange with
// const stream parameter).
if (Token::Match(tok, "const std :: string %var% [,)]")) {
passedByValueError(tok, tok->strAt(4));
} else if (Token::Match(tok, "const std :: %type% < std| ::| %type% > %var% [,)]")) {
passedByValueError(tok, Token::findsimplematch(tok->tokAt(5), ">")->strAt(1));
} else if (Token::Match(tok, "const std :: %type% < std| ::| %type% , std| ::| %type% > %var% [,)]")) {
passedByValueError(tok, Token::findsimplematch(tok->tokAt(7), ">")->strAt(1));
} else if (Token::Match(tok, "const %type% %var% [,)]")) {
// Check if type is a struct or class.
if (symbolDatabase->isClassOrStruct(tok->strAt(1))) {
passedByValueError(tok, tok->strAt(2));
}
}
}
}
}
}
void CheckOther::passedByValueError(const Token *tok, const std::string &parname)
{
reportError(tok, Severity::performance, "passedByValue",
"Function parameter '" + parname + "' should be passed by reference.\n"
"Parameter '" + parname + "' is passed as a value. It could be passed "
"as a (const) reference which is usually faster and recommended in C++.");
}
//---------------------------------------------------------------------------
// Check usage of char variables..
//---------------------------------------------------------------------------
static bool isChar(const Variable* var)
{
return(var && !var->isPointer() && !var->isArray() && (var->typeEndToken()->str() == "char" || var->typeEndToken()->previous()->str() == "char"));
}
static bool isSignedChar(const Variable* var)
{
return(isChar(var) && !var->typeEndToken()->isUnsigned() && !var->typeEndToken()->previous()->isUnsigned());
}
void CheckOther::checkCharVariable()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if ((tok->str() != ".") && Token::Match(tok->next(), "%var% [ %var% ]")) {
const Variable* var = symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId());
if (isSignedChar(var))
charArrayIndexError(tok->next());
}
else if (Token::Match(tok, "[;{}] %var% = %any% [&|] %any% ;")) {
// is a char variable used in the calculation?
if (!isSignedChar(symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId())) &&
!isSignedChar(symbolDatabase->getVariableFromVarId(tok->tokAt(5)->varId())))
continue;
// it's ok with a bitwise and where the other operand is 0xff or less..
if (tok->strAt(4) == "&") {
if (tok->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok->strAt(3)))
continue;
if (tok->tokAt(5)->isNumber() && MathLib::isGreater("0x100", tok->strAt(5)))
continue;
}
// is the result stored in a short|int|long?
const Variable *var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (!(var && Token::Match(var->typeEndToken(), "short|int|long")))
continue;
// This is an error..
charBitOpError(tok->tokAt(4));
}
else if (Token::Match(tok, "[;{}] %var% = %any% [&|] ( * %var% ) ;")) {
const Variable* var = symbolDatabase->getVariableFromVarId(tok->tokAt(7)->varId());
if (!var || !var->isPointer())
continue;
// it's ok with a bitwise and where the other operand is 0xff or less..
if (tok->strAt(4) == "&" && tok->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok->strAt(3)))
continue;
// is the result stored in a short|int|long?
var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (!(var && Token::Match(var->typeEndToken(), "short|int|long")))
continue;
// This is an error..
charBitOpError(tok->tokAt(4));
}
}
}
void CheckOther::charArrayIndexError(const Token *tok)
{
reportError(tok,
Severity::warning,
"charArrayIndex",
"Using char type as array index\n"
"Using signed char type as array index. If the value "
"can be greater than 127 there will be a buffer overflow "
"(because of sign extension).");
}
void CheckOther::charBitOpError(const Token *tok)
{
reportError(tok,
Severity::warning,
"charBitOp",
"When using char variables in bit operations, sign extension can generate unexpected results.\n"
"When using char variables in bit operations, sign extension can generate unexpected results. For example:\n"
" char c = 0x80;\n"
" int i = 0 | c;\n"
" if (i & 0x8000)\n"
" printf(\"not expected\");\n"
"The 'not expected' will be printed on the screen.");
}
//---------------------------------------------------------------------------
// Incomplete statement..
//---------------------------------------------------------------------------
void CheckOther::checkIncompleteStatement()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (tok->str() == "(") {
tok = tok->link();
if (Token::simpleMatch(tok, ") {") && Token::simpleMatch(tok->next()->link(), "} ;"))
tok = tok->next()->link();
}
else if (Token::simpleMatch(tok, "= {"))
tok = tok->next()->link();
else if (tok->str() == "{" && Token::Match(tok->tokAt(-2), "%type% %var%"))
tok = tok->link();
else if (Token::Match(tok, "[;{}] %str%") || Token::Match(tok, "[;{}] %num%")) {
// No warning if numeric constant is followed by a "." or ","
if (Token::Match(tok->next(), "%num% [,.]"))
continue;
// bailout if there is a "? :" in this statement
bool bailout = false;
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
if (tok2->str() == "?")
bailout = true;
else if (tok2->str() == ";")
break;
}
if (bailout)
continue;
constStatementError(tok->next(), tok->next()->isNumber() ? "numeric" : "string");
}
}
}
void CheckOther::constStatementError(const Token *tok, const std::string &type)
{
reportError(tok, Severity::warning, "constStatement", "Redundant code: Found a statement that begins with " + type + " constant");
}
//---------------------------------------------------------------------------
// str plus char
//---------------------------------------------------------------------------
void CheckOther::strPlusChar()
{
// Don't use this check for Java and C# programs..
if (_tokenizer->isJavaOrCSharp()) {
return;
}
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "[=(] %str% + %any%")) {
// char constant..
if (tok->strAt(3)[0] == '\'')
strPlusCharError(tok->next());
// char variable..
unsigned int varid = tok->tokAt(3)->varId();
if (isChar(symbolDatabase->getVariableFromVarId(varid)))
strPlusCharError(tok->next());
}
}
}
void CheckOther::strPlusCharError(const Token *tok)
{
reportError(tok, Severity::error, "strPlusChar", "Unusual pointer arithmetic");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
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->strAt(4)) &&
MathLib::toLongNumber(tok->strAt(4)) == 0L) {
zerodivError(tok);
}
}
}
void CheckOther::zerodivError(const Token *tok)
{
reportError(tok, Severity::error, "zerodiv", "Division by zero");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkMathFunctions()
{
const SymbolDatabase *db = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = db->scopeList.begin(); scope != db->scopeList.end(); ++scope) {
if (scope->type != Scope::eFunction)
continue;
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
if (tok->varId())
continue;
if (Token::Match(tok, "log|log10 ( %num% )")) {
bool isNegative = MathLib::isNegative(tok->strAt(2));
bool isInt = MathLib::isInt(tok->strAt(2));
bool isFloat = MathLib::isFloat(tok->strAt(2));
if (isNegative && isInt && MathLib::toLongNumber(tok->strAt(2)) <= 0) {
mathfunctionCallError(tok); // case log(-2)
} else if (isNegative && isFloat && MathLib::toDoubleNumber(tok->strAt(2)) <= 0.) {
mathfunctionCallError(tok); // case log(-2.0)
} else if (!isNegative && isFloat && MathLib::toDoubleNumber(tok->strAt(2)) <= 0.) {
mathfunctionCallError(tok); // case log(0.0)
} else if (!isNegative && isInt && MathLib::toLongNumber(tok->strAt(2)) <= 0) {
mathfunctionCallError(tok); // case log(0)
}
}
// 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->strAt(2))) > 1.0) {
mathfunctionCallError(tok);
}
// sqrt( x ): if x is negative the result is undefined
else if (Token::Match(tok, "sqrt|sqrtf|sqrtl ( %num% )") &&
MathLib::isNegative(tok->strAt(2))) {
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->strAt(2)) &&
MathLib::isNullValue(tok->strAt(4))) {
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 ( %any%")) {
const Token* nextArg = tok->tokAt(2)->nextArgument();
if (nextArg && nextArg->isNumber() && MathLib::isNullValue(nextArg->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->strAt(2)) &&
MathLib::isNegative(tok->strAt(4))) {
mathfunctionCallError(tok, 2);
}
}
}
}
void CheckOther::mathfunctionCallError(const Token *tok, const unsigned int numParam)
{
if (tok) {
if (numParam == 1)
reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->strAt(2) + " to " + tok->str() + "() leads to undefined result");
else if (numParam == 2)
reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->strAt(2) + " and " + tok->strAt(4) + " to " + tok->str() + "() leads to undefined result");
} else
reportError(tok, Severity::error, "wrongmathcall", "Passing value " " to " "() leads to undefined result");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkCCTypeFunctions()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (tok->varId() == 0 &&
Token::Match(tok, "isalnum|isalpha|iscntrl|isdigit|isgraph|islower|isprint|ispunct|isspace|isupper|isxdigit ( %num% ,|)") &&
MathLib::isNegative(tok->strAt(2))) {
cctypefunctionCallError(tok, tok->str(), tok->tokAt(2)->str());
}
}
}
void CheckOther::cctypefunctionCallError(const Token *tok, const std::string &functionName, const std::string &value)
{
reportError(tok, Severity::error, "wrongcctypecall", "Passing value " + value + " to " + functionName + "() cause undefined behavior, which may lead to a crash");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
/** Is there a function with given name? */
static bool isFunction(const std::string &name, const Token *startToken)
{
const std::string pattern1(name + " (");
for (const Token *tok = startToken; tok; tok = tok->next()) {
// skip executable scopes etc
if (tok->str() == "(") {
tok = tok->link();
if (Token::simpleMatch(tok, ") {"))
tok = tok->next()->link();
else if (Token::simpleMatch(tok, ") const {"))
tok = tok->linkAt(2);
}
// function declaration/implementation found
if ((tok->str() == "*" || (tok->isName() && tok->str().find(":") ==std::string::npos))
&& Token::simpleMatch(tok->next(), pattern1.c_str()))
return true;
}
return false;
}
void CheckOther::checkMisusedScopedObject()
{
// Skip this check for .c files
if (_tokenizer->isC()) {
return;
}
const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "[;{}] %var% (")
&& Token::simpleMatch(tok->linkAt(2), ") ;")
&& symbolDatabase->isClassOrStruct(tok->next()->str())
&& !isFunction(tok->next()->str(), _tokenizer->tokens())) {
tok = tok->next();
misusedScopeObjectError(tok, tok->str());
tok = tok->next();
}
}
}
}
void CheckOther::misusedScopeObjectError(const Token *tok, const std::string& varname)
{
reportError(tok, Severity::error,
"unusedScopedObject", "instance of \"" + varname + "\" object destroyed immediately");
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
void CheckOther::checkIncorrectStringCompare()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, ". substr ( %any% , %num% ) ==|!= %str%")) {
MathLib::bigint clen = MathLib::toLongNumber(tok->strAt(5));
std::size_t slen = Token::getStrLength(tok->tokAt(8));
if (clen != (int)slen) {
incorrectStringCompareError(tok->next(), "substr", tok->strAt(8), tok->strAt(5));
}
} else if (Token::Match(tok, "%str% ==|!= %var% . substr ( %any% , %num% )")) {
MathLib::bigint clen = MathLib::toLongNumber(tok->strAt(8));
std::size_t slen = Token::getStrLength(tok);
if (clen != (int)slen) {
incorrectStringCompareError(tok->next(), "substr", tok->str(), tok->strAt(8));
}
} else if (Token::Match(tok, "&&|%oror% %str% &&|%oror%|)")) {
// assert(condition && "debug message") would be considered a fp.
if (tok->str() == "&&" && tok->strAt(2) == ")" && tok->linkAt(2)->previous()->str() == "assert")
continue;
incorrectStringBooleanError(tok->next(), tok->strAt(1));
} else if (Token::Match(tok, "if|while|assert ( %str% &&|%oror%|)")) {
// assert("debug message" && condition) would be considered a fp.
if (tok->strAt(3) == "&&" && tok->str() == "assert")
continue;
incorrectStringBooleanError(tok->tokAt(2), tok->strAt(2));
}
}
}
void CheckOther::incorrectStringCompareError(const Token *tok, const std::string& func, const std::string &string, const std::string &len)
{
reportError(tok, Severity::warning, "incorrectStringCompare", "String literal " + string + " doesn't match length argument for " + func + "(" + len + ").");
}
void CheckOther::incorrectStringBooleanError(const Token *tok, const std::string& string)
{
reportError(tok, Severity::warning, "incorrectStringBooleanError", "A boolean comparison with the string literal " + string + " is always true.");
}
//-----------------------------------------------------------------------------
// check for duplicate expressions in if statements
// if (a) { } else if (a) { }
//-----------------------------------------------------------------------------
static bool expressionHasSideEffects(const Token *first, const Token *last)
{
for (const Token *tok = first; tok != last->next(); tok = tok->next()) {
// check for assignment
if (tok->isAssignmentOp())
return true;
// check for inc/dec
else if (Token::Match(tok, "++|--"))
return true;
// check for function call
else if (Token::Match(tok, "%var% (") &&
!(Token::Match(tok, "c_str|string") || tok->isStandardType()))
return true;
}
return false;
}
void CheckOther::checkDuplicateIf()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
const Token* const tok = scope->classDef;
// only check if statements
if (scope->type != Scope::eIf || !tok)
continue;
std::map<std::string, const Token*> expressionMap;
// get the expression from the token stream
std::string expression = tok->tokAt(2)->stringify(tok->next()->link());
// save the expression and its location
expressionMap.insert(std::make_pair(expression, tok));
// find the next else if (...) statement
const Token *tok1 = tok->next()->link()->next()->link();
// check all the else if (...) statements
while (Token::simpleMatch(tok1, "} else if (") &&
Token::simpleMatch(tok1->linkAt(3), ") {")) {
// get the expression from the token stream
expression = tok1->tokAt(4)->stringify(tok1->linkAt(3));
// try to look up the expression to check for duplicates
std::map<std::string, const Token *>::iterator it = expressionMap.find(expression);
// found a duplicate
if (it != expressionMap.end()) {
// check for expressions that have side effects and ignore them
if (!expressionHasSideEffects(tok1->tokAt(4), tok1->linkAt(3)->previous()))
duplicateIfError(it->second, tok1->next());
}
// not a duplicate expression so save it and its location
else
expressionMap.insert(std::make_pair(expression, tok1->next()));
// find the next else if (...) statement
tok1 = tok1->linkAt(3)->next()->link();
}
}
}
void CheckOther::duplicateIfError(const Token *tok1, const Token *tok2)
{
std::list<const Token *> toks;
toks.push_back(tok2);
toks.push_back(tok1);
reportError(toks, Severity::style, "duplicateIf", "Found duplicate if expressions.\n"
"Finding the same expression more than once is suspicious and might indicate "
"a cut and paste or logic error. Please examine this code carefully to determine "
"if it is correct.");
}
//-----------------------------------------------------------------------------
// check for duplicate code in if and else branches
// if (a) { b = true; } else { b = true; }
//-----------------------------------------------------------------------------
void CheckOther::checkDuplicateBranch()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
const Token* tok = scope->classDef;
if ((scope->type != Scope::eIf && scope->type != Scope::eElseIf) || !tok)
continue;
if (tok->str() == "else")
tok = tok->next();
// check all the code in the function for if (..) else
if (tok && tok->next() && Token::simpleMatch(tok->next()->link(), ") {") &&
Token::simpleMatch(tok->next()->link()->next()->link(), "} else {")) {
// save if branch code
std::string branch1 = tok->next()->link()->tokAt(2)->stringify(tok->next()->link()->next()->link());
// find else branch
const Token *tok1 = tok->next()->link()->next()->link();
// save else branch code
std::string branch2 = tok1->tokAt(3)->stringify(tok1->linkAt(2));
// check for duplicates
if (branch1 == branch2)
duplicateBranchError(tok, tok1->tokAt(2));
}
}
}
//-----------------------------------------------------------------------------
// Check for double free
// free(p); free(p);
//-----------------------------------------------------------------------------
void CheckOther::checkDoubleFree()
{
std::set<unsigned int> freedVariables;
std::set<unsigned int> closeDirVariables;
for (const Token* tok = _tokenizer->tokens(); tok; tok = tok->next()) {
// Keep track of any variables passed to "free()", "g_free()" or "closedir()",
// and report an error if the same variable is passed twice.
if (Token::Match(tok, "free|g_free|closedir ( %var% )")) {
unsigned int var = tok->tokAt(2)->varId();
if (var) {
if (Token::Match(tok, "free|g_free")) {
if (freedVariables.find(var) != freedVariables.end())
doubleFreeError(tok, tok->tokAt(2)->str());
else
freedVariables.insert(var);
} else if (tok->str() == "closedir") {
if (closeDirVariables.find(var) != closeDirVariables.end())
doubleCloseDirError(tok, tok->tokAt(2)->str());
else
closeDirVariables.insert(var);
}
}
}
// Keep track of any variables operated on by "delete" or "delete[]"
// and report an error if the same variable is delete'd twice.
else if (Token::Match(tok, "delete %var% ;") || Token::Match(tok, "delete [ ] %var% ;")) {
int varIdx = (tok->strAt(1) == "[") ? 3 : 1;
unsigned int var = tok->tokAt(varIdx)->varId();
if (var) {
if (freedVariables.find(var) != freedVariables.end())
doubleFreeError(tok, tok->tokAt(varIdx)->str());
else
freedVariables.insert(var);
}
}
// If this scope doesn't return, clear the set of previously freed variables
else if (tok->str() == "}" && _tokenizer->IsScopeNoReturn(tok)) {
freedVariables.clear();
closeDirVariables.clear();
}
// If a variable is passed to a function, remove it from the set of previously freed variables
else if (Token::Match(tok, "%var% (") && !Token::Match(tok, "printf|sprintf|snprintf|fprintf|if|while")) {
// If this is a new function definition, clear all variables
if (Token::Match(tok->next()->link(), ") {")) {
freedVariables.clear();
closeDirVariables.clear();
}
// If it is a function call, then clear those variables in its argument list
else if (Token::Match(tok->next()->link(), ") ;")) {
for (const Token* tok2 = tok->tokAt(2); tok2 != tok->linkAt(1); tok2 = tok2->next()) {
if (Token::Match(tok2, "%var%")) {
unsigned int var = tok2->varId();
if (var) {
freedVariables.erase(var);
closeDirVariables.erase(var);
}
}
}
}
}
// If a pointer is assigned a new value, remove it from the set of previously freed variables
else if (Token::Match(tok, "%var% =")) {
unsigned int var = tok->varId();
if (var) {
freedVariables.erase(var);
closeDirVariables.erase(var);
}
}
// Any control statements in-between delete, free() or closedir() statements
// makes it unclear whether any subsequent statements would be redundant.
if (Token::Match(tok, "else|break|continue|goto|return")) {
freedVariables.clear();
closeDirVariables.clear();
}
}
}
void CheckOther::doubleFreeError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "doubleFree", "Memory pointed to by '" + varname +"' is freed twice.");
}
void CheckOther::doubleCloseDirError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "doubleCloseDir", "Directory handle '" + varname +"' closed twice.");
}
void CheckOther::duplicateBranchError(const Token *tok1, const Token *tok2)
{
std::list<const Token *> toks;
toks.push_back(tok2);
toks.push_back(tok1);
reportError(toks, Severity::style, "duplicateBranch", "Found duplicate branches for if and else.\n"
"Finding the same code for an if branch and an else branch is suspicious and "
"might indicate a cut and paste or logic error. Please examine this code "
"carefully to determine if it is correct.");
}
namespace {
struct ExpressionTokens {
const Token *start;
const Token *end;
int count;
bool inconclusiveFunction;
ExpressionTokens(const Token *s, const Token *e): start(s), end(e), count(1), inconclusiveFunction(false) {}
};
struct FuncFilter {
FuncFilter(const Scope *scope, const Token *tok): _scope(scope), _tok(tok) {}
bool operator()(const Function &func) {
bool matchingFunc = func.type == Function::eFunction &&
_tok->str() == func.token->str();
// either a class function, or a global function with the same name
return (_scope && _scope == func.functionScope && matchingFunc) ||
(!_scope && matchingFunc);
}
const Scope *_scope;
const Token *_tok;
};
bool inconclusiveFunctionCall(const SymbolDatabase *symbolDatabase,
const std::list<Function> &constFunctions,
const ExpressionTokens &tokens)
{
const Token *start = tokens.start;
const Token *end = tokens.end;
// look for function calls between start and end...
for (const Token *tok = start; tok && tok != end; tok = tok->next()) {
if (tok != start && tok->str() == "(") {
// go back to find the function call.
const Token *prev = tok->previous();
if (!prev)
continue;
if (prev->str() == ">") {
// ignore template functions like boo<double>()
return true;
}
if (prev->isName()) {
const Variable *v = 0;
if (Token::Match(prev->tokAt(-2), "%var% .")) {
const Token *scope = prev->tokAt(-2);
v = symbolDatabase->getVariableFromVarId(scope->varId());
}
// hard coded list of safe, no-side-effect functions
if (v == 0 && Token::Match(prev, "strcmp|strncmp|strlen|memcmp|strcasecmp|strncasecmp"))
return false;
std::list<Function>::const_iterator it = std::find_if(constFunctions.begin(),
constFunctions.end(),
FuncFilter(v ? v->type(): 0, prev));
if (it == constFunctions.end())
return true;
}
}
}
return false;
}
class Expressions {
public:
Expressions(const SymbolDatabase *symbolDatabase, const
std::list<Function> &constFunctions)
: _start(0),
_lastTokens(0),
_symbolDatabase(symbolDatabase),
_constFunctions(constFunctions) { }
void endExpr(const Token *end) {
const std::string &e = _expression.str();
if (!e.empty()) {
std::map<std::string, ExpressionTokens>::iterator it = _expressions.find(e);
bool lastInconclusive = _lastTokens && _lastTokens->inconclusiveFunction;
if (it == _expressions.end()) {
ExpressionTokens exprTokens(_start, end);
exprTokens.inconclusiveFunction = lastInconclusive || inconclusiveFunctionCall(
_symbolDatabase, _constFunctions, exprTokens);
_expressions.insert(std::make_pair(e, exprTokens));
_lastTokens = &_expressions.find(e)->second;
} else {
ExpressionTokens &expr = it->second;
expr.count += 1;
expr.inconclusiveFunction = expr.inconclusiveFunction || lastInconclusive;
_lastTokens = &expr;
}
}
_expression.str("");
_start = 0;
}
void append(const Token *tok) {
if (!_start)
_start = tok;
_expression << tok->str();
}
std::map<std::string,ExpressionTokens> &getMap() {
return _expressions;
}
private:
std::map<std::string, ExpressionTokens> _expressions;
std::ostringstream _expression;
const Token *_start;
ExpressionTokens *_lastTokens;
const SymbolDatabase *_symbolDatabase;
const std::list<Function> &_constFunctions;
};
bool notconst(const Function &func)
{
return !func.isConst;
}
void getConstFunctions(const SymbolDatabase *symbolDatabase, std::list<Function> &constFunctions)
{
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
std::list<Function>::const_iterator func;
// only add const functions that do not have a non-const overloaded version
// since it is pretty much impossible to tell which is being called.
typedef std::map<std::string, std::list<Function> > StringFunctionMap;
StringFunctionMap functionsByName;
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
StringFunctionMap::iterator it = functionsByName.find(func->token->str());
Scope *currScope = const_cast<Scope*>(&*scope);
if (it == functionsByName.end()) {
std::list<Function> tmp;
tmp.push_back(*func);
tmp.back().functionScope = currScope;
functionsByName[func->token->str()] = tmp;
} else {
it->second.push_back(*func);
it->second.back().functionScope = currScope;
}
}
for (StringFunctionMap::iterator it = functionsByName.begin();
it != functionsByName.end(); ++it) {
std::list<Function>::const_iterator nc = std::find_if(it->second.begin(), it->second.end(), notconst);
if (nc == it->second.end()) {
// ok to add all of them
constFunctions.splice(constFunctions.end(), it->second);
}
}
}
}
}
void CheckOther::checkExpressionRange(const std::list<Function> &constFunctions,
const Token *start,
const Token *end,
const std::string &toCheck)
{
if (!start || !end)
return;
Expressions expressions(_tokenizer->getSymbolDatabase(), constFunctions);
std::string opName;
int level = 0;
for (const Token *tok = start->next(); tok && tok != end; tok = tok->next()) {
if (tok->str() == ")")
level--;
else if (tok->str() == "(")
level++;
if (level == 0 && Token::Match(tok, toCheck.c_str())) {
opName = tok->str();
expressions.endExpr(tok);
} else {
expressions.append(tok);
}
}
expressions.endExpr(end);
std::map<std::string,ExpressionTokens>::const_iterator it = expressions.getMap().begin();
for (; it != expressions.getMap().end(); ++it) {
// check expression..
bool valid = true;
unsigned int parantheses = 0; // ()
unsigned int brackets = 0; // []
// taking address?
if (Token::Match(it->second.end->previous(), "%op% &")) {
continue;
}
for (const Token *tok = it->second.start; tok && tok != it->second.end; tok = tok->next()) {
if (tok->str() == "(") {
++parantheses;
} else if (tok->str() == ")") {
if (parantheses == 0) {
valid = false;
break;
}
--parantheses;
} else if (tok->str() == "[") {
++brackets;
} else if (tok->str() == "]") {
if (brackets == 0) {
valid = false;
break;
}
--brackets;
} else if (tok->str() == "++" || tok->str() == "--") {
valid = false;
break;
}
}
if (!valid || parantheses!=0 || brackets!=0)
continue;
const ExpressionTokens &expr = it->second;
if (expr.count > 1 && !expr.inconclusiveFunction) {
duplicateExpressionError(expr.start, expr.start, opName);
}
}
}
void CheckOther::complexDuplicateExpressionCheck(const std::list<Function> &constFunctions,
const Token *classStart,
const std::string &toCheck,
const std::string &alt)
{
std::string statementStart(",|=|return");
if (!alt.empty())
statementStart += "|" + alt;
std::string statementEnd(";|,");
if (!alt.empty())
statementEnd += "|" + alt;
for (const Token *tok = classStart; tok && tok != classStart->link(); tok = tok->next()) {
if (!Token::Match(tok, toCheck.c_str()))
continue;
// look backward for the start of the statement
const Token *start = 0;
int level = 0;
for (const Token *tok1 = tok->previous(); tok1 && tok1 != classStart; tok1 = tok1->previous()) {
if (tok1->str() == ")")
level++;
else if (tok1->str() == "(")
level--;
if (level < 0 || (level == 0 && Token::Match(tok1, statementStart.c_str()))) {
start = tok1;
break;
}
}
const Token *end = 0;
level = 0;
// look for the end of the statement
for (const Token *tok1 = tok->next(); tok1 && tok1 != classStart->link(); tok1 = tok1->next()) {
if (tok1->str() == ")")
level--;
else if (tok1->str() == "(")
level++;
if (level < 0 || (level == 0 && Token::Match(tok1, statementEnd.c_str()))) {
end = tok1;
break;
}
}
checkExpressionRange(constFunctions, start, end, toCheck);
}
}
//---------------------------------------------------------------------------
// check for the same expression on both sides of an operator
// (x == x), (x && x), (x || x)
// (x.y == x.y), (x.y && x.y), (x.y || x.y)
//---------------------------------------------------------------------------
void CheckOther::checkDuplicateExpression()
{
if (!_settings->isEnabled("style"))
return;
// Parse all executing scopes..
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
std::list<Function> constFunctions;
getConstFunctions(symbolDatabase, constFunctions);
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "%or%", "");
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "%oror%", "");
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "&", "%oror%|%or%");
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "&&", "%oror%|%or%");
for (const Token *tok = scope->classStart; tok && tok != scope->classStart->link(); tok = tok->next()) {
if (Token::Match(tok, ",|=|return|(|&&|%oror% %var% ==|!=|<=|>=|<|>|- %var% )|&&|%oror%|;|,") &&
tok->strAt(1) == tok->strAt(3)) {
// float == float and float != float are valid NaN checks
if (Token::Match(tok->tokAt(2), "==|!=") && tok->next()->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (var && var->typeStartToken() == var->typeEndToken()) {
if (Token::Match(var->typeStartToken(), "float|double"))
continue;
}
}
duplicateExpressionError(tok->next(), tok->tokAt(3), tok->strAt(2));
} else if (Token::Match(tok, ",|=|return|(|&&|%oror% %var% . %var% ==|!=|<=|>=|<|>|- %var% . %var% )|&&|%oror%|;|,") &&
tok->strAt(1) == tok->strAt(5) && tok->strAt(3) == tok->strAt(7)) {
duplicateExpressionError(tok->next(), tok->tokAt(6), tok->strAt(4));
}
}
}
}
void CheckOther::duplicateExpressionError(const Token *tok1, const Token *tok2, const std::string &op)
{
std::list<const Token *> toks;
toks.push_back(tok2);
toks.push_back(tok1);
reportError(toks, Severity::style, "duplicateExpression", "Same expression on both sides of \'" + op + "\'.\n"
"Finding the same expression on both sides of an operator is suspicious and might "
"indicate a cut and paste or logic error. Please examine this code carefully to "
"determine if it is correct.");
}
//---------------------------------------------------------------------------
// Check for string comparison involving two static strings.
// if(strcmp("00FF00","00FF00")==0) // <- statement is always true
//---------------------------------------------------------------------------
void CheckOther::checkAlwaysTrueOrFalseStringCompare()
{
if (!_settings->isEnabled("style") && !_settings->isEnabled("performance"))
return;
const char pattern1[] = "strncmp|strcmp|stricmp|strcmpi|strcasecmp|wcscmp ( %str% , %str% ";
const char pattern2[] = "QString :: compare ( %str% , %str% )";
const char pattern3[] = "strncmp|strcmp|stricmp|strcmpi|strcasecmp|wcscmp ( %var% , %var% ";
const Token *tok = _tokenizer->tokens();
while (tok && (tok = Token::findmatch(tok, pattern1)) != NULL) {
alwaysTrueFalseStringCompareError(tok, tok->strAt(2), tok->strAt(4));
tok = tok->tokAt(5);
}
tok = _tokenizer->tokens();
while (tok && (tok = Token::findmatch(tok, pattern2)) != NULL) {
alwaysTrueFalseStringCompareError(tok, tok->strAt(4), tok->strAt(6));
tok = tok->tokAt(7);
}
tok = _tokenizer->tokens();
while (tok && (tok = Token::findmatch(tok, pattern3)) != NULL) {
const Token *var1 = tok->tokAt(2);
const Token *var2 = tok->tokAt(4);
const std::string &str1 = var1->str();
const std::string &str2 = var2->str();
if (str1 == str2)
alwaysTrueStringVariableCompareError(tok, str1, str2);
tok = tok->tokAt(5);
}
}
void CheckOther::alwaysTrueFalseStringCompareError(const Token *tok, const std::string& str1, const std::string& str2)
{
const std::size_t stringLen = 10;
const std::string string1 = (str1.size() < stringLen) ? str1 : (str1.substr(0, stringLen-2) + "..");
const std::string string2 = (str2.size() < stringLen) ? str2 : (str2.substr(0, stringLen-2) + "..");
if (str1 == str2) {
reportError(tok, Severity::warning, "staticStringCompare",
"Comparison of always identical static strings.\n"
"The compared strings, '" + string1 + "' and '" + string2 + "', are always identical. "
"If the purpose is to compare these two strings, the comparison is unnecessary. "
"If the strings are supposed to be different, then there is a bug somewhere.");
} else if (_settings->isEnabled("performance")) {
reportError(tok, Severity::performance, "staticStringCompare",
"Unnecessary comparison of static strings.\n"
"The compared strings, '" + string1 + "' and '" + string2 + "', are static and always different. "
"If the purpose is to compare these two strings, the comparison is unnecessary.");
}
}
void CheckOther::alwaysTrueStringVariableCompareError(const Token *tok, const std::string& str1, const std::string& str2)
{
reportError(tok, Severity::warning, "stringCompare",
"Comparison of identical string variables.\n"
"The compared strings, '" + str1 + "' and '" + str2 + "', are identical. "
"This could be a logic bug.");
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void CheckOther::sizeofsizeof()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "sizeof (| sizeof")) {
sizeofsizeofError(tok);
tok = tok->next();
}
}
}
void CheckOther::sizeofsizeofError(const Token *tok)
{
reportError(tok, Severity::warning,
"sizeofsizeof", "Calling sizeof for 'sizeof'.\n"
"Calling sizeof for 'sizeof looks like a suspicious code and "
"most likely there should be just one 'sizeof'. The current "
"code is equivalent to 'sizeof(size_t)'");
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void CheckOther::sizeofCalculation()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::simpleMatch(tok, "sizeof (")) {
unsigned int parlevel = 0;
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
if (tok2->str() == "(")
++parlevel;
else if (tok2->str() == ")") {
if (parlevel <= 1)
break;
--parlevel;
} else if (Token::Match(tok2, "+|/")) {
sizeofCalculationError(tok2);
break;
}
}
}
}
}
void CheckOther::sizeofCalculationError(const Token *tok)
{
reportError(tok, Severity::warning,
"sizeofCalculation", "Found calculation inside sizeof()");
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void CheckOther::checkAssignBoolToPointer()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "[;{}] %var% = %bool% ;")) {
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
const Variable *var1(symbolDatabase->getVariableFromVarId(tok->next()->varId()));
// Is variable a pointer?
if (var1 && var1->nameToken()->strAt(-1) == "*")
assignBoolToPointerError(tok->next());
}
}
}
void CheckOther::assignBoolToPointerError(const Token *tok)
{
reportError(tok, Severity::error, "assignBoolToPointer",
"Assigning bool value to pointer (converting bool value to address)");
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void CheckOther::checkComparisonOfBoolExpressionWithInt()
{
if (!_settings->isEnabled("style"))
return;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "&&|%oror% %any% ) ==|!=|>|< %num%")) {
const std::string& op = tok->strAt(3);
const std::string& num = tok->strAt(4);
if ((op == "<" || num != "0") && (op == ">" || num != "1")) {
comparisonOfBoolExpressionWithIntError(tok->next());
}
}
else if (Token::Match(tok, "%num% ==|!=|>|< ( %any% &&|%oror%")) {
const std::string& op = tok->strAt(1);
const std::string& num = tok->str();
if ((op == ">" || num != "0") && (op == "<" || num != "1")) {
comparisonOfBoolExpressionWithIntError(tok->next());
}
}
}
}
void CheckOther::comparisonOfBoolExpressionWithIntError(const Token *tok)
{
reportError(tok, Severity::warning, "compareBoolExpressionWithInt",
"Comparison of a boolean expression with an integer other than 0 or 1.");
}
//---------------------------------------------------------------------------
// Check testing sign of unsigned variables.
//---------------------------------------------------------------------------
void CheckOther::checkSignOfUnsignedVariable()
{
if (!_settings->isEnabled("style"))
return;
const bool inconclusive = _tokenizer->codeWithTemplates();
if (inconclusive && !_settings->inconclusive)
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
// check all the code in the function
for (const Token *tok = scope->classStart; tok && tok != scope->classStart->link(); tok = tok->next()) {
if (Token::Match(tok, ";|(|&&|%oror% %var% <|<= 0 ;|)|&&|%oror%") && tok->next()->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedLessThanZeroError(tok->next(), tok->next()->str(), inconclusive);
} else if (Token::Match(tok, ";|(|&&|%oror% 0 > %var% ;|)|&&|%oror%") && tok->tokAt(3)->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedLessThanZeroError(tok->tokAt(3), tok->strAt(3), inconclusive);
} else if (Token::Match(tok, ";|(|&&|%oror% 0 <= %var% ;|)|&&|%oror%") && tok->tokAt(3)->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedPositiveError(tok->tokAt(3), tok->strAt(3), inconclusive);
} else if (Token::Match(tok, ";|(|&&|%oror% %var% >= 0 ;|)|&&|%oror%") && tok->next()->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedPositiveError(tok->next(), tok->next()->str(), inconclusive);
}
}
}
}
void CheckOther::unsignedLessThanZeroError(const Token *tok, const std::string &varname, bool inconclusive)
{
if (inconclusive) {
reportInconclusiveError(tok, Severity::style, "unsignedLessThanZero",
"Checking if unsigned variable '" + varname + "' is less than zero. This might be a false warning.\n"
"Checking if unsigned variable '" + varname + "' is less than zero. An unsigned "
"variable will never be negative so it is either pointless or an error to check if it is. "
"It's not known if the used constant is a template parameter or not and therefore "
"this message might be a false warning");
} else {
reportError(tok, Severity::style, "unsignedLessThanZero",
"Checking if unsigned variable '" + varname + "' is less than zero.\n"
"An unsigned variable will never be negative so it is either pointless or "
"an error to check if it is.");
}
}
void CheckOther::unsignedPositiveError(const Token *tok, const std::string &varname, bool inconclusive)
{
if (inconclusive) {
reportInconclusiveError(tok, Severity::style, "unsignedPositive",
"An unsigned variable '" + varname + "' can't be negative so it is unnecessary to test it. This might be a false warning.\n"
"An unsigned variable '" + varname + "' can't be negative so it is unnecessary to test it. "
"It's not known if the used constant is a "
"template parameter or not and therefore this message might be a false warning");
} else {
reportError(tok, Severity::style, "unsignedPositive",
"An unsigned variable '" + varname + "' can't be negative so it is unnecessary to test it.");
}
}
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