420 lines
22 KiB
C++
420 lines
22 KiB
C++
/*
|
|
* Cppcheck - A tool for static C/C++ code analysis
|
|
* Copyright (C) 2007-2016 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/>.
|
|
*/
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check functions
|
|
//---------------------------------------------------------------------------
|
|
|
|
#include "checkfunctions.h"
|
|
#include "astutils.h"
|
|
#include "symboldatabase.h"
|
|
#include <cmath>
|
|
|
|
//---------------------------------------------------------------------------
|
|
|
|
|
|
// Register this check class (by creating a static instance of it)
|
|
namespace {
|
|
CheckFunctions instance;
|
|
}
|
|
|
|
static const CWE CWE252(252U); // Unchecked Return Value
|
|
static const CWE CWE477(477U); // Use of Obsolete Functions
|
|
static const CWE CWE758(758U); // Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
|
|
static const CWE CWE628(628U); // Function Call with Incorrectly Specified Arguments
|
|
static const CWE CWE686(686U); // Function Call With Incorrect Argument Type
|
|
static const CWE CWE687(687U); // Function Call With Incorrectly Specified Argument Value
|
|
static const CWE CWE688(688U); // Function Call With Incorrect Variable or Reference as Argument
|
|
|
|
void CheckFunctions::checkProhibitedFunctions()
|
|
{
|
|
const bool checkAlloca = _settings->isEnabled(Settings::WARNING) && ((_settings->standards.c >= Standards::C99 && _tokenizer->isC()) || _settings->standards.cpp >= Standards::CPP11);
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
for (unsigned int i = 0; i < symbolDatabase->functionScopes.size(); i++) {
|
|
const Scope* scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
|
|
if (!Token::Match(tok, "%name% (") && tok->varId() == 0)
|
|
continue;
|
|
// alloca() is special as it depends on the code being C or C++, so it is not in Library
|
|
if (checkAlloca && Token::simpleMatch(tok, "alloca (") && (!tok->function() || tok->function()->nestedIn->type == Scope::eGlobal)) {
|
|
if (_tokenizer->isC()) {
|
|
if (_settings->standards.c > Standards::C89)
|
|
reportError(tok, Severity::warning, "allocaCalled",
|
|
"Obsolete function 'alloca' called. In C99 and later it is recommended to use a variable length array instead.\n"
|
|
"The obsolete function 'alloca' is called. In C99 and later it is recommended to use a variable length array or "
|
|
"a dynamically allocated array instead. The function 'alloca' is dangerous for many reasons "
|
|
"(http://stackoverflow.com/questions/1018853/why-is-alloca-not-considered-good-practice and http://linux.die.net/man/3/alloca).");
|
|
} else
|
|
reportError(tok, Severity::warning, "allocaCalled",
|
|
"Obsolete function 'alloca' called.\n"
|
|
"The obsolete function 'alloca' is called. In C++11 and later it is recommended to use std::array<> or "
|
|
"a dynamically allocated array instead. The function 'alloca' is dangerous for many reasons "
|
|
"(http://stackoverflow.com/questions/1018853/why-is-alloca-not-considered-good-practice and http://linux.die.net/man/3/alloca).");
|
|
} else {
|
|
if (tok->function() && tok->function()->hasBody())
|
|
continue;
|
|
|
|
const Library::WarnInfo* wi = _settings->library.getWarnInfo(tok);
|
|
if (wi) {
|
|
if (_settings->isEnabled(wi->severity) && _settings->standards.c >= wi->standards.c && _settings->standards.cpp >= wi->standards.cpp) {
|
|
reportError(tok, wi->severity, tok->str() + "Called", wi->message, CWE477, false);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check <valid> and <not-bool>
|
|
//---------------------------------------------------------------------------
|
|
void CheckFunctions::invalidFunctionUsage()
|
|
{
|
|
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (!Token::Match(tok, "%name% ( !!)"))
|
|
continue;
|
|
const Token * const functionToken = tok;
|
|
const std::vector<const Token *> arguments = getArguments(tok);
|
|
for (unsigned int argnr = 1; argnr <= arguments.size(); ++argnr) {
|
|
const Token * const argtok = arguments[argnr-1];
|
|
|
|
// check <valid>...</valid>
|
|
const ValueFlow::Value *invalidValue = argtok->getInvalidValue(functionToken,argnr,_settings);
|
|
if (invalidValue) {
|
|
invalidFunctionArgError(argtok, functionToken->next()->astOperand1()->expressionString(), argnr, invalidValue, _settings->library.validarg(functionToken, argnr));
|
|
}
|
|
|
|
if (astIsBool(argtok)) {
|
|
// check <not-bool>
|
|
if (_settings->library.isboolargbad(functionToken, argnr))
|
|
invalidFunctionArgBoolError(argtok, functionToken->str(), argnr);
|
|
|
|
// Are the values 0 and 1 valid?
|
|
else if (!_settings->library.isargvalid(functionToken, argnr, 0))
|
|
invalidFunctionArgError(argtok, functionToken->str(), argnr, nullptr, _settings->library.validarg(functionToken, argnr));
|
|
else if (!_settings->library.isargvalid(functionToken, argnr, 1))
|
|
invalidFunctionArgError(argtok, functionToken->str(), argnr, nullptr, _settings->library.validarg(functionToken, argnr));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckFunctions::invalidFunctionArgError(const Token *tok, const std::string &functionName, int argnr, const ValueFlow::Value *invalidValue, const std::string &validstr)
|
|
{
|
|
std::ostringstream errmsg;
|
|
if (invalidValue && invalidValue->condition)
|
|
errmsg << ValueFlow::eitherTheConditionIsRedundant(invalidValue->condition)
|
|
<< " or " << functionName << "() argument nr " << argnr
|
|
<< " can have invalid value.";
|
|
else
|
|
errmsg << "Invalid " << functionName << "() argument nr " << argnr << '.';
|
|
if (invalidValue)
|
|
errmsg << " The value is " << invalidValue->intvalue << " but the valid values are '" << validstr << "'.";
|
|
else
|
|
errmsg << " The value is 0 or 1 (boolean) but the valid values are '" << validstr << "'.";
|
|
reportError(tok,
|
|
(!invalidValue || !invalidValue->condition) ? Severity::error : Severity::warning,
|
|
"invalidFunctionArg",
|
|
errmsg.str(),
|
|
CWE628,
|
|
invalidValue && invalidValue->inconclusive);
|
|
}
|
|
|
|
void CheckFunctions::invalidFunctionArgBoolError(const Token *tok, const std::string &functionName, int argnr)
|
|
{
|
|
std::ostringstream errmsg;
|
|
errmsg << "Invalid " << functionName << "() argument nr " << argnr << ". A non-boolean value is required.";
|
|
reportError(tok, Severity::error, "invalidFunctionArgBool", errmsg.str(), CWE628, false);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check for ignored return values.
|
|
//---------------------------------------------------------------------------
|
|
void CheckFunctions::checkIgnoredReturnValue()
|
|
{
|
|
if (!_settings->isEnabled(Settings::WARNING))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
// skip c++11 initialization, ({...})
|
|
if (Token::Match(tok, "%var%|(|, {"))
|
|
tok = tok->linkAt(1);
|
|
else if (tok->str() == "(")
|
|
tok = tok->link();
|
|
|
|
if (tok->varId() || !Token::Match(tok, "%name% ("))
|
|
continue;
|
|
|
|
if (tok->next()->astParent())
|
|
continue;
|
|
|
|
if (!tok->scope()->isExecutable()) {
|
|
tok = tok->scope()->classEnd;
|
|
continue;
|
|
}
|
|
|
|
const Token* parent = tok;
|
|
while (parent->astParent() && parent->astParent()->str() == "::")
|
|
parent = parent->astParent();
|
|
|
|
if (CHECK_WRONG_DATA(tok->next()->astOperand1()) && !tok->next()->astParent() && (!tok->function() || !Token::Match(tok->function()->retDef, "void %name%")) && _settings->library.isUseRetVal(tok))
|
|
ignoredReturnValueError(tok, tok->next()->astOperand1()->expressionString());
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckFunctions::ignoredReturnValueError(const Token* tok, const std::string& function)
|
|
{
|
|
reportError(tok, Severity::warning, "ignoredReturnValue",
|
|
"Return value of function " + function + "() is not used.", CWE252, false);
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Detect passing wrong values to <cmath> functions like atan(0, x);
|
|
//---------------------------------------------------------------------------
|
|
void CheckFunctions::checkMathFunctions()
|
|
{
|
|
const bool styleC99 = _settings->isEnabled(Settings::STYLE) && _settings->standards.c != Standards::C89 && _settings->standards.cpp != Standards::CPP03;
|
|
const bool printWarnings = _settings->isEnabled(Settings::WARNING);
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (tok->varId())
|
|
continue;
|
|
if (printWarnings && Token::Match(tok, "%name% ( !!)")) {
|
|
if (tok->strAt(-1) != "."
|
|
&& Token::Match(tok, "log|logf|logl|log10|log10f|log10l ( %num% )")) {
|
|
const std::string& number = tok->strAt(2);
|
|
bool isNegative = MathLib::isNegative(number);
|
|
bool isInt = MathLib::isInt(number);
|
|
bool isFloat = MathLib::isFloat(number);
|
|
if (isNegative && isInt && MathLib::toLongNumber(number) <= 0) {
|
|
mathfunctionCallWarning(tok); // case log(-2)
|
|
} else if (isNegative && isFloat && MathLib::toDoubleNumber(number) <= 0.) {
|
|
mathfunctionCallWarning(tok); // case log(-2.0)
|
|
} else if (!isNegative && isFloat && MathLib::toDoubleNumber(number) <= 0.) {
|
|
mathfunctionCallWarning(tok); // case log(0.0)
|
|
} else if (!isNegative && isInt && MathLib::toLongNumber(number) <= 0) {
|
|
mathfunctionCallWarning(tok); // case log(0)
|
|
}
|
|
}
|
|
|
|
// acos( x ), asin( x ) where x is defined for interval [-1,+1], but not beyond
|
|
else if (Token::Match(tok, "acos|acosl|acosf|asin|asinf|asinl ( %num% )")) {
|
|
if (std::fabs(MathLib::toDoubleNumber(tok->strAt(2))) > 1.0)
|
|
mathfunctionCallWarning(tok);
|
|
}
|
|
// sqrt( x ): if x is negative the result is undefined
|
|
else if (Token::Match(tok, "sqrt|sqrtf|sqrtl ( %num% )")) {
|
|
if (MathLib::isNegative(tok->strAt(2)))
|
|
mathfunctionCallWarning(tok);
|
|
}
|
|
// atan2 ( x , y): x and y can not be zero, because this is mathematically not defined
|
|
else if (Token::Match(tok, "atan2|atan2f|atan2l ( %num% , %num% )")) {
|
|
if (MathLib::isNullValue(tok->strAt(2)) && MathLib::isNullValue(tok->strAt(4)))
|
|
mathfunctionCallWarning(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|fmodf|fmodl (")) {
|
|
const Token* nextArg = tok->tokAt(2)->nextArgument();
|
|
if (nextArg && nextArg->isNumber() && MathLib::isNullValue(nextArg->str()))
|
|
mathfunctionCallWarning(tok, 2);
|
|
}
|
|
// pow ( x , y) If x is zero, and y is negative --> division by zero
|
|
else if (Token::Match(tok, "pow|powf|powl ( %num% , %num% )")) {
|
|
if (MathLib::isNullValue(tok->strAt(2)) && MathLib::isNegative(tok->strAt(4)))
|
|
mathfunctionCallWarning(tok, 2);
|
|
}
|
|
}
|
|
|
|
if (styleC99) {
|
|
if (Token::Match(tok, "%num% - erf (") && Tokenizer::isOneNumber(tok->str()) && tok->next()->astOperand2() == tok->tokAt(3)) {
|
|
mathfunctionCallWarning(tok, "1 - erf(x)", "erfc(x)");
|
|
} else if (Token::simpleMatch(tok, "exp (") && Token::Match(tok->linkAt(1), ") - %num%") && Tokenizer::isOneNumber(tok->linkAt(1)->strAt(2)) && tok->linkAt(1)->next()->astOperand1() == tok->next()) {
|
|
mathfunctionCallWarning(tok, "exp(x) - 1", "expm1(x)");
|
|
} else if (Token::simpleMatch(tok, "log (") && tok->next()->astOperand2()) {
|
|
const Token* plus = tok->next()->astOperand2();
|
|
if (plus->str() == "+" && ((plus->astOperand1() && Tokenizer::isOneNumber(plus->astOperand1()->str())) || (plus->astOperand2() && Tokenizer::isOneNumber(plus->astOperand2()->str()))))
|
|
mathfunctionCallWarning(tok, "log(1 + x)", "log1p(x)");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckFunctions::mathfunctionCallWarning(const Token *tok, const unsigned int numParam)
|
|
{
|
|
if (tok) {
|
|
if (numParam == 1)
|
|
reportError(tok, Severity::warning, "wrongmathcall", "Passing value " + tok->strAt(2) + " to " + tok->str() + "() leads to implementation-defined result.", CWE758, false);
|
|
else if (numParam == 2)
|
|
reportError(tok, Severity::warning, "wrongmathcall", "Passing values " + tok->strAt(2) + " and " + tok->strAt(4) + " to " + tok->str() + "() leads to implementation-defined result.", CWE758, false);
|
|
} else
|
|
reportError(tok, Severity::warning, "wrongmathcall", "Passing value '#' to #() leads to implementation-defined result.", CWE758, false);
|
|
}
|
|
|
|
void CheckFunctions::mathfunctionCallWarning(const Token *tok, const std::string& oldexp, const std::string& newexp)
|
|
{
|
|
reportError(tok, Severity::style, "unpreciseMathCall", "Expression '" + oldexp + "' can be replaced by '" + newexp + "' to avoid loss of precision.", CWE758, false);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// memset(p, y, 0 /* bytes to fill */) <- 2nd and 3rd arguments inverted
|
|
//---------------------------------------------------------------------------
|
|
void CheckFunctions::memsetZeroBytes()
|
|
{
|
|
// FIXME:
|
|
// Replace this with library configuration.
|
|
// For instance:
|
|
// <arg nr="3">
|
|
// <warn knownIntValue="0" severity="warning" msg="..."/>
|
|
// </arg>
|
|
|
|
if (!_settings->isEnabled(Settings::WARNING))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "memset|wmemset (") && (numberOfArguments(tok)==3)) {
|
|
const std::vector<const Token *> &arguments = getArguments(tok);
|
|
if (!CHECK_WRONG_DATA(arguments.size() == 3U))
|
|
continue;
|
|
const Token* lastParamTok = arguments[2];
|
|
if (lastParamTok->str() == "0")
|
|
memsetZeroBytesError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckFunctions::memsetZeroBytesError(const Token *tok)
|
|
{
|
|
const std::string summary("memset() called to fill 0 bytes.");
|
|
const std::string verbose(summary + " The second and third arguments might be inverted."
|
|
" The function memset ( void * ptr, int value, size_t num ) sets the"
|
|
" first num bytes of the block of memory pointed by ptr to the specified value.");
|
|
reportError(tok, Severity::warning, "memsetZeroBytes", summary + "\n" + verbose, CWE687, false);
|
|
}
|
|
|
|
void CheckFunctions::memsetInvalid2ndParam()
|
|
{
|
|
// FIXME:
|
|
// Replace this with library configuration.
|
|
// For instance:
|
|
// <arg nr="2">
|
|
// <not-float/>
|
|
// <warn possibleIntValue=":-129,256:" severity="warning" msg="..."/>
|
|
// </arg>
|
|
|
|
const bool printPortability = _settings->isEnabled(Settings::PORTABILITY);
|
|
const bool printWarning = _settings->isEnabled(Settings::WARNING);
|
|
if (!printWarning && !printPortability)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok && (tok != scope->classEnd); tok = tok->next()) {
|
|
if (!Token::simpleMatch(tok, "memset ("))
|
|
continue;
|
|
|
|
const std::vector<const Token *> args = getArguments(tok);
|
|
if (args.size() != 3)
|
|
continue;
|
|
|
|
// Second parameter is zero literal, i.e. 0.0f
|
|
const Token * const secondParamTok = args[1];
|
|
if (Token::Match(secondParamTok, "%num% ,") && MathLib::isNullValue(secondParamTok->str()))
|
|
continue;
|
|
|
|
// Check if second parameter is a float variable or a float literal != 0.0f
|
|
if (printPortability && astIsFloat(secondParamTok,false)) {
|
|
memsetFloatError(secondParamTok, secondParamTok->expressionString());
|
|
}
|
|
|
|
if (printWarning && secondParamTok->isNumber()) { // Check if the second parameter is a literal and is out of range
|
|
const long long int value = MathLib::toLongNumber(secondParamTok->str());
|
|
if (value < -128 || value > 255) // FIXME: Use platform char_bits
|
|
memsetValueOutOfRangeError(secondParamTok, secondParamTok->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckFunctions::memsetFloatError(const Token *tok, const std::string &var_value)
|
|
{
|
|
const std::string message("The 2nd memset() argument '" + var_value +
|
|
"' is a float, its representation is implementation defined.");
|
|
const std::string verbose(message + " memset() is used to set each byte of a block of memory to a specific value and"
|
|
" the actual representation of a floating-point value is implementation defined.");
|
|
reportError(tok, Severity::portability, "memsetFloat", message + "\n" + verbose, CWE688, false);
|
|
}
|
|
|
|
void CheckFunctions::memsetValueOutOfRangeError(const Token *tok, const std::string &value)
|
|
{
|
|
const std::string message("The 2nd memset() argument '" + value + "' doesn't fit into an 'unsigned char'.");
|
|
const std::string verbose(message + " The 2nd parameter is passed as an 'int', but the function fills the block of memory using the 'unsigned char' conversion of this value.");
|
|
reportError(tok, Severity::warning, "memsetValueOutOfRange", message + "\n" + verbose, CWE686, false);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// --check-library => warn for unconfigured functions
|
|
//---------------------------------------------------------------------------
|
|
|
|
void CheckFunctions::checkLibraryMatchFunctions()
|
|
{
|
|
if (!_settings->checkLibrary || !_settings->isEnabled(Settings::INFORMATION))
|
|
return;
|
|
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (Token::Match(tok, "%name% (") &&
|
|
!Token::Match(tok, "for|if|while|switch|sizeof|catch|asm|return") &&
|
|
!tok->function() &&
|
|
!tok->varId() &&
|
|
!tok->type() &&
|
|
!tok->isStandardType() &&
|
|
tok->linkAt(1)->strAt(1) != "(" &&
|
|
!Token::simpleMatch(tok->astParent(), "new") &&
|
|
tok->astParent() == tok->next() &&
|
|
_settings->library.isNotLibraryFunction(tok)) {
|
|
reportError(tok,
|
|
Severity::information,
|
|
"checkLibraryFunction",
|
|
"--check-library: There is no matching configuration for function " + tok->str() + "()");
|
|
}
|
|
}
|
|
}
|