676 lines
34 KiB
C++
676 lines
34 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2022 Cppcheck team.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//---------------------------------------------------------------------------
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// Check functions
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//---------------------------------------------------------------------------
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#include "checkfunctions.h"
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#include "astutils.h"
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#include "mathlib.h"
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#include "standards.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "tokenize.h"
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#include "valueflow.h"
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#include <iomanip>
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#include <ostream>
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#include <unordered_map>
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#include <vector>
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//---------------------------------------------------------------------------
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// Register this check class (by creating a static instance of it)
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namespace {
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CheckFunctions instance;
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}
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static const CWE CWE252(252U); // Unchecked Return Value
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static const CWE CWE477(477U); // Use of Obsolete Functions
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static const CWE CWE758(758U); // Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
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static const CWE CWE628(628U); // Function Call with Incorrectly Specified Arguments
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static const CWE CWE686(686U); // Function Call With Incorrect Argument Type
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static const CWE CWE687(687U); // Function Call With Incorrectly Specified Argument Value
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static const CWE CWE688(688U); // Function Call With Incorrect Variable or Reference as Argument
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void CheckFunctions::checkProhibitedFunctions()
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{
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const bool checkAlloca = mSettings->severity.isEnabled(Severity::warning) && ((mSettings->standards.c >= Standards::C99 && mTokenizer->isC()) || mSettings->standards.cpp >= Standards::CPP11);
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope *scope : symbolDatabase->functionScopes) {
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for (const Token* tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
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if (!Token::Match(tok, "%name% (") && tok->varId() == 0)
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continue;
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// alloca() is special as it depends on the code being C or C++, so it is not in Library
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if (checkAlloca && Token::simpleMatch(tok, "alloca (") && (!tok->function() || tok->function()->nestedIn->type == Scope::eGlobal)) {
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if (mTokenizer->isC()) {
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if (mSettings->standards.c > Standards::C89)
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reportError(tok, Severity::warning, "allocaCalled",
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"$symbol:alloca\n"
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"Obsolete function 'alloca' called. In C99 and later it is recommended to use a variable length array instead.\n"
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"The obsolete function 'alloca' is called. In C99 and later it is recommended to use a variable length array or "
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"a dynamically allocated array instead. The function 'alloca' is dangerous for many reasons "
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"(http://stackoverflow.com/questions/1018853/why-is-alloca-not-considered-good-practice and http://linux.die.net/man/3/alloca).");
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} else
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reportError(tok, Severity::warning, "allocaCalled",
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"$symbol:alloca\n"
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"Obsolete function 'alloca' called.\n"
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"The obsolete function 'alloca' is called. In C++11 and later it is recommended to use std::array<> or "
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"a dynamically allocated array instead. The function 'alloca' is dangerous for many reasons "
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"(http://stackoverflow.com/questions/1018853/why-is-alloca-not-considered-good-practice and http://linux.die.net/man/3/alloca).");
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} else {
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if (tok->function() && tok->function()->hasBody())
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continue;
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const Library::WarnInfo* wi = mSettings->library.getWarnInfo(tok);
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if (wi) {
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if (mSettings->severity.isEnabled(wi->severity) && mSettings->standards.c >= wi->standards.c && mSettings->standards.cpp >= wi->standards.cpp) {
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const std::string daca = mSettings->daca ? "prohibited" : "";
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reportError(tok, wi->severity, daca + tok->str() + "Called", wi->message, CWE477, Certainty::normal);
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}
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}
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}
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}
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}
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}
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//---------------------------------------------------------------------------
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// Check <valid>, <strz> and <not-bool>
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//---------------------------------------------------------------------------
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void CheckFunctions::invalidFunctionUsage()
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{
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const SymbolDatabase* symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope *scope : symbolDatabase->functionScopes) {
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for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
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if (!Token::Match(tok, "%name% ( !!)"))
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continue;
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const Token * const functionToken = tok;
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const std::vector<const Token *> arguments = getArguments(tok);
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for (int argnr = 1; argnr <= arguments.size(); ++argnr) {
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const Token * const argtok = arguments[argnr-1];
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// check <valid>...</valid>
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const ValueFlow::Value *invalidValue = argtok->getInvalidValue(functionToken,argnr,mSettings);
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if (invalidValue) {
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invalidFunctionArgError(argtok, functionToken->next()->astOperand1()->expressionString(), argnr, invalidValue, mSettings->library.validarg(functionToken, argnr));
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}
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if (astIsBool(argtok)) {
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// check <not-bool>
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if (mSettings->library.isboolargbad(functionToken, argnr))
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invalidFunctionArgBoolError(argtok, functionToken->str(), argnr);
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// Are the values 0 and 1 valid?
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else if (!mSettings->library.isIntArgValid(functionToken, argnr, 0))
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invalidFunctionArgError(argtok, functionToken->str(), argnr, nullptr, mSettings->library.validarg(functionToken, argnr));
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else if (!mSettings->library.isIntArgValid(functionToken, argnr, 1))
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invalidFunctionArgError(argtok, functionToken->str(), argnr, nullptr, mSettings->library.validarg(functionToken, argnr));
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}
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// check <strz>
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if (mSettings->library.isargstrz(functionToken, argnr)) {
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if (Token::Match(argtok, "& %var% !![") && argtok->next() && argtok->next()->valueType()) {
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const ValueType * valueType = argtok->next()->valueType();
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const Variable * variable = argtok->next()->variable();
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if ((valueType->type == ValueType::Type::CHAR || (valueType->type == ValueType::Type::RECORD && Token::Match(argtok, "& %var% . %var% ,|)"))) &&
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!variable->isArray() &&
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(variable->isConst() || !variable->isGlobal()) &&
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(!argtok->next()->hasKnownValue() || argtok->next()->getValue(0) == nullptr)) {
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invalidFunctionArgStrError(argtok, functionToken->str(), argnr);
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}
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}
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const ValueType* const valueType = argtok->valueType();
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const Variable* const variable = argtok->variable();
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// Is non-null terminated local variable of type char (e.g. char buf[] = {'x'};) ?
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if (variable && variable->isLocal()
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&& valueType && (valueType->type == ValueType::Type::CHAR || valueType->type == ValueType::Type::WCHAR_T)
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&& !isVariablesChanged(variable->declEndToken(), functionToken, 0 /*indirect*/, { variable }, mSettings, mTokenizer->isCPP())) {
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const Token* varTok = variable->declEndToken();
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auto count = -1; // Find out explicitly set count, e.g.: char buf[3] = {...}. Variable 'count' is set to 3 then.
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if (varTok && Token::simpleMatch(varTok->astOperand1(), "["))
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{
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const Token* const countTok = varTok->astOperand1()->astOperand2();
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if (countTok && countTok->hasKnownIntValue())
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count = countTok->getKnownIntValue();
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}
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if (Token::simpleMatch(varTok, "= {")) {
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varTok = varTok->tokAt(1);
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auto charsUntilFirstZero = 0;
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bool search = true;
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while (search && varTok && !Token::simpleMatch(varTok->next(), "}")) {
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varTok = varTok->next();
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if (!Token::simpleMatch(varTok, ",")) {
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if (Token::Match(varTok, "%op%")) {
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varTok = varTok->next();
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continue;
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}
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++charsUntilFirstZero;
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if (varTok && varTok->hasKnownIntValue() && varTok->getKnownIntValue() == 0)
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search=false; // stop counting for cases like char buf[3] = {'x', '\0', 'y'};
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}
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}
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if (varTok && varTok->hasKnownIntValue() && varTok->getKnownIntValue() != 0
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&& (count == -1 || (count > 0 && count <= charsUntilFirstZero))) {
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invalidFunctionArgStrError(argtok, functionToken->str(), argnr);
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}
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} else if (count > -1 && Token::Match(varTok, "= %str%")) {
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const Token* strTok = varTok->getValueTokenMinStrSize(mSettings);
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if (strTok) {
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const int strSize = Token::getStrArraySize(strTok);
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if (strSize > count && strTok->str().find('\0') == std::string::npos)
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invalidFunctionArgStrError(argtok, functionToken->str(), argnr);
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}
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}
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}
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}
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}
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}
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}
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}
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void CheckFunctions::invalidFunctionArgError(const Token *tok, const std::string &functionName, int argnr, const ValueFlow::Value *invalidValue, const std::string &validstr)
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{
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std::ostringstream errmsg;
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errmsg << "$symbol:" << functionName << '\n';
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if (invalidValue && invalidValue->condition)
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errmsg << ValueFlow::eitherTheConditionIsRedundant(invalidValue->condition)
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<< " or $symbol() argument nr " << argnr << " can have invalid value.";
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else
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errmsg << "Invalid $symbol() argument nr " << argnr << '.';
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if (invalidValue)
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errmsg << " The value is " << std::setprecision(10) << (invalidValue->isIntValue() ? invalidValue->intvalue : invalidValue->floatValue) << " but the valid values are '" << validstr << "'.";
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else
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errmsg << " The value is 0 or 1 (boolean) but the valid values are '" << validstr << "'.";
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if (invalidValue)
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reportError(getErrorPath(tok, invalidValue, "Invalid argument"),
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invalidValue->errorSeverity() && invalidValue->isKnown() ? Severity::error : Severity::warning,
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"invalidFunctionArg",
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errmsg.str(),
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CWE628,
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invalidValue->isInconclusive() ? Certainty::inconclusive : Certainty::normal);
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else
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reportError(tok,
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Severity::error,
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"invalidFunctionArg",
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errmsg.str(),
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CWE628,
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Certainty::normal);
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}
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void CheckFunctions::invalidFunctionArgBoolError(const Token *tok, const std::string &functionName, int argnr)
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{
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std::ostringstream errmsg;
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errmsg << "$symbol:" << functionName << '\n';
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errmsg << "Invalid $symbol() argument nr " << argnr << ". A non-boolean value is required.";
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reportError(tok, Severity::error, "invalidFunctionArgBool", errmsg.str(), CWE628, Certainty::normal);
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}
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void CheckFunctions::invalidFunctionArgStrError(const Token *tok, const std::string &functionName, nonneg int argnr)
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{
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std::ostringstream errmsg;
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errmsg << "$symbol:" << functionName << '\n';
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errmsg << "Invalid $symbol() argument nr " << argnr << ". A nul-terminated string is required.";
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reportError(tok, Severity::error, "invalidFunctionArgStr", errmsg.str(), CWE628, Certainty::normal);
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}
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//---------------------------------------------------------------------------
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// Check for ignored return values.
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//---------------------------------------------------------------------------
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void CheckFunctions::checkIgnoredReturnValue()
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{
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if (!mSettings->severity.isEnabled(Severity::warning) && !mSettings->severity.isEnabled(Severity::style))
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return;
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope *scope : symbolDatabase->functionScopes) {
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for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
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// skip c++11 initialization, ({...})
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if (Token::Match(tok, "%var%|(|,|return {"))
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tok = tok->linkAt(1);
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else if (Token::Match(tok, "[(<]") && tok->link())
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tok = tok->link();
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if (tok->varId() || !Token::Match(tok, "%name% (") || tok->isKeyword())
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continue;
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const Token *parent = tok->next()->astParent();
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while (Token::Match(parent, "%cop%")) {
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if (Token::Match(parent, "<<|>>") && !parent->astParent())
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break;
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parent = parent->astParent();
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}
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if (parent)
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continue;
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if (!tok->scope()->isExecutable()) {
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tok = tok->scope()->bodyEnd;
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continue;
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}
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if ((!tok->function() || !Token::Match(tok->function()->retDef, "void %name%")) &&
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!WRONG_DATA(!tok->next()->astOperand1(), tok)) {
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const Library::UseRetValType retvalTy = mSettings->library.getUseRetValType(tok);
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if (mSettings->severity.isEnabled(Severity::warning) &&
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((retvalTy == Library::UseRetValType::DEFAULT) ||
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(tok->function() && tok->function()->isAttributeNodiscard())))
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ignoredReturnValueError(tok, tok->next()->astOperand1()->expressionString());
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else if (mSettings->severity.isEnabled(Severity::style) &&
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retvalTy == Library::UseRetValType::ERROR_CODE)
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ignoredReturnErrorCode(tok, tok->next()->astOperand1()->expressionString());
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}
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}
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}
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}
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void CheckFunctions::ignoredReturnValueError(const Token* tok, const std::string& function)
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{
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reportError(tok, Severity::warning, "ignoredReturnValue",
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"$symbol:" + function + "\nReturn value of function $symbol() is not used.", CWE252, Certainty::normal);
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}
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void CheckFunctions::ignoredReturnErrorCode(const Token* tok, const std::string& function)
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{
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reportError(tok, Severity::style, "ignoredReturnErrorCode",
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"$symbol:" + function + "\nError code from the return value of function $symbol() is not used.", CWE252, Certainty::normal);
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}
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//---------------------------------------------------------------------------
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// Check for ignored return values.
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//---------------------------------------------------------------------------
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static const Token *checkMissingReturnScope(const Token *tok, const Library &library);
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void CheckFunctions::checkMissingReturn()
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{
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope *scope : symbolDatabase->functionScopes) {
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const Function *function = scope->function;
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if (!function || !function->hasBody())
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continue;
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if (function->name() == "main" && !(mSettings->standards.c < Standards::C99 && mTokenizer->isC()))
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continue;
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if (function->type != Function::Type::eFunction && function->type != Function::Type::eOperatorEqual)
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continue;
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if (Token::Match(function->retDef, "%name% (") && function->retDef->isUpperCaseName())
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continue;
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if (Function::returnsVoid(function, true))
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continue;
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const Token *errorToken = checkMissingReturnScope(scope->bodyEnd, mSettings->library);
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if (errorToken)
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missingReturnError(errorToken);
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}
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}
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static bool isForwardJump(const Token *gotoToken)
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{
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if (!Token::Match(gotoToken, "goto %name% ;"))
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return false;
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for (const Token *prev = gotoToken; gotoToken; gotoToken = gotoToken->previous()) {
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if (Token::Match(prev, "%name% :") && prev->str() == gotoToken->next()->str())
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return true;
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if (prev->str() == "{" && prev->scope()->type == Scope::eFunction)
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return false;
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}
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return false;
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}
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static const Token *checkMissingReturnScope(const Token *tok, const Library &library)
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{
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const Token *lastStatement = nullptr;
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while ((tok = tok->previous()) != nullptr) {
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if (tok->str() == ")")
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tok = tok->link();
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if (tok->str() == "{")
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return lastStatement ? lastStatement : tok->next();
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if (tok->str() == "}") {
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for (const Token *prev = tok->link()->previous(); prev && prev->scope() == tok->scope() && !Token::Match(prev, "[;{}]"); prev = prev->previous()) {
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if (prev->isKeyword() && Token::Match(prev, "return|throw"))
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return nullptr;
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if (prev->str() == "goto" && !isForwardJump(prev))
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return nullptr;
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}
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if (tok->scope()->type == Scope::ScopeType::eSwitch) {
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// find reachable break / !default
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bool hasDefault = false;
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bool reachable = false;
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for (const Token *switchToken = tok->link()->next(); switchToken != tok; switchToken = switchToken->next()) {
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if (reachable && Token::simpleMatch(switchToken, "break ;")) {
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if (Token::simpleMatch(switchToken->previous(), "}") && !checkMissingReturnScope(switchToken->previous(), library))
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reachable = false;
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else
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return switchToken;
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}
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if (switchToken->isKeyword() && Token::Match(switchToken, "return|throw"))
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reachable = false;
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if (Token::Match(switchToken, "%name% (") && library.isnoreturn(switchToken))
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reachable = false;
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if (Token::Match(switchToken, "case|default"))
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reachable = true;
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if (Token::simpleMatch(switchToken, "default :"))
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hasDefault = true;
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else if (switchToken->str() == "{" && (switchToken->scope()->isLoopScope() || switchToken->scope()->type == Scope::ScopeType::eSwitch))
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switchToken = switchToken->link();
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}
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if (!hasDefault)
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return tok->link();
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} else if (tok->scope()->type == Scope::ScopeType::eIf) {
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const Token *condition = tok->scope()->classDef->next()->astOperand2();
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if (condition && condition->hasKnownIntValue() && condition->getKnownIntValue() == 1)
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return checkMissingReturnScope(tok, library);
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return tok;
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} else if (tok->scope()->type == Scope::ScopeType::eElse) {
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const Token *errorToken = checkMissingReturnScope(tok, library);
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if (errorToken)
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return errorToken;
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tok = tok->link();
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if (Token::simpleMatch(tok->tokAt(-2), "} else {"))
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return checkMissingReturnScope(tok->tokAt(-2), library);
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return tok;
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}
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// FIXME
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return nullptr;
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}
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if (tok->isKeyword() && Token::Match(tok, "return|throw"))
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return nullptr;
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if (tok->str() == "goto" && !isForwardJump(tok))
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return nullptr;
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if (Token::Match(tok, "%name% (") && !library.isnotnoreturn(tok)) {
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const Token *start = tok;
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while (Token::Match(start->tokAt(-2), "%name% :: %name%"))
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start = start->tokAt(-2);
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if (Token::Match(start->previous(), "[;{}] %name% ::|("))
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return nullptr;
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}
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if (Token::Match(tok, "[;{}] %name% :"))
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return tok;
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if (Token::Match(tok, "; !!}") && !lastStatement)
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lastStatement = tok->next();
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}
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return nullptr;
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}
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void CheckFunctions::missingReturnError(const Token* tok)
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{
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reportError(tok, Severity::error, "missingReturn",
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"Found a exit path from function with non-void return type that has missing return statement", CWE758, Certainty::normal);
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}
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//---------------------------------------------------------------------------
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// Detect passing wrong values to <cmath> functions like atan(0, x);
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//---------------------------------------------------------------------------
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void CheckFunctions::checkMathFunctions()
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{
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const bool styleC99 = mSettings->severity.isEnabled(Severity::style) && mSettings->standards.c != Standards::C89 && mSettings->standards.cpp != Standards::CPP03;
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const bool printWarnings = mSettings->severity.isEnabled(Severity::warning);
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope *scope : symbolDatabase->functionScopes) {
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for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
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if (tok->varId())
|
|
continue;
|
|
if (printWarnings && Token::Match(tok, "%name% ( !!)")) {
|
|
if (tok->strAt(-1) != "."
|
|
&& Token::Match(tok, "log|logf|logl|log10|log10f|log10l|log2|log2f|log2l ( %num% )")) {
|
|
const std::string& number = tok->strAt(2);
|
|
if ((MathLib::isInt(number) && MathLib::toLongNumber(number) <= 0) ||
|
|
(MathLib::isFloat(number) && MathLib::toDoubleNumber(number) <= 0.))
|
|
mathfunctionCallWarning(tok);
|
|
} else if (Token::Match(tok, "log1p|log1pf|log1pl ( %num% )")) {
|
|
const std::string& number = tok->strAt(2);
|
|
if ((MathLib::isInt(number) && MathLib::toLongNumber(number) <= -1) ||
|
|
(MathLib::isFloat(number) && MathLib::toDoubleNumber(number) <= -1.))
|
|
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 && 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 nonneg int numParam)
|
|
{
|
|
if (tok) {
|
|
if (numParam == 1)
|
|
reportError(tok, Severity::warning, "wrongmathcall", "$symbol:" + tok->str() + "\nPassing value " + tok->strAt(2) + " to $symbol() leads to implementation-defined result.", CWE758, Certainty::normal);
|
|
else if (numParam == 2)
|
|
reportError(tok, Severity::warning, "wrongmathcall", "$symbol:" + tok->str() + "\nPassing values " + tok->strAt(2) + " and " + tok->strAt(4) + " to $symbol() leads to implementation-defined result.", CWE758, Certainty::normal);
|
|
} else
|
|
reportError(tok, Severity::warning, "wrongmathcall", "Passing value '#' to #() leads to implementation-defined result.", CWE758, Certainty::normal);
|
|
}
|
|
|
|
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, Certainty::normal);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// 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 (!mSettings->severity.isEnabled(Severity::warning))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope *scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "memset|wmemset (") && (numberOfArguments(tok)==3)) {
|
|
const std::vector<const Token *> &arguments = getArguments(tok);
|
|
if (WRONG_DATA(arguments.size() != 3U, tok))
|
|
continue;
|
|
const Token* lastParamTok = arguments[2];
|
|
if (MathLib::isNullValue(lastParamTok->str()))
|
|
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, Certainty::normal);
|
|
}
|
|
|
|
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 = mSettings->severity.isEnabled(Severity::portability);
|
|
const bool printWarning = mSettings->severity.isEnabled(Severity::warning);
|
|
if (!printWarning && !printPortability)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope *scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart->next(); tok && (tok != scope->bodyEnd); 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());
|
|
const long long sCharMin = mSettings->signedCharMin();
|
|
const long long uCharMax = mSettings->unsignedCharMax();
|
|
if (value < sCharMin || value > uCharMax)
|
|
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, Certainty::normal);
|
|
}
|
|
|
|
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, Certainty::normal);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// --check-library => warn for unconfigured functions
|
|
//---------------------------------------------------------------------------
|
|
|
|
void CheckFunctions::checkLibraryMatchFunctions()
|
|
{
|
|
if (!mSettings->checkLibrary || !mSettings->severity.isEnabled(Severity::information))
|
|
return;
|
|
|
|
bool insideNew = false;
|
|
for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (!tok->scope() || !tok->scope()->isExecutable())
|
|
continue;
|
|
|
|
if (tok->str() == "new")
|
|
insideNew = true;
|
|
else if (tok->str() == ";")
|
|
insideNew = false;
|
|
else if (insideNew)
|
|
continue;
|
|
|
|
if (!Token::Match(tok, "%name% (") || Token::Match(tok, "asm|sizeof|catch"))
|
|
continue;
|
|
|
|
if (tok->varId() != 0 || tok->type() || tok->isStandardType() || tok->isControlFlowKeyword())
|
|
continue;
|
|
|
|
if (tok->linkAt(1)->strAt(1) == "(")
|
|
continue;
|
|
|
|
if (tok->function())
|
|
continue;
|
|
|
|
if (!mSettings->library.isNotLibraryFunction(tok))
|
|
continue;
|
|
|
|
const std::string &functionName = mSettings->library.getFunctionName(tok);
|
|
if (functionName.empty() || mSettings->library.functions.find(functionName) != mSettings->library.functions.end())
|
|
continue;
|
|
|
|
reportError(tok,
|
|
Severity::information,
|
|
"checkLibraryFunction",
|
|
"--check-library: There is no matching configuration for function " + functionName + "()");
|
|
}
|
|
}
|
|
|
|
// Check for problems to compiler apply (Named) Return Value Optimization for local variable
|
|
// Technically we have different guarantees between standard versions
|
|
// details: https://en.cppreference.com/w/cpp/language/copy_elision
|
|
void CheckFunctions::returnLocalStdMove()
|
|
{
|
|
if (!mTokenizer->isCPP() || mSettings->standards.cpp < Standards::CPP11)
|
|
return;
|
|
|
|
if (!mSettings->severity.isEnabled(Severity::performance))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope *scope : symbolDatabase->functionScopes) {
|
|
// Expect return by-value
|
|
if (Function::returnsReference(scope->function, true))
|
|
continue;
|
|
const auto rets = Function::findReturns(scope->function);
|
|
for (const Token* ret : rets) {
|
|
if (!Token::simpleMatch(ret->tokAt(-3), "std :: move ("))
|
|
continue;
|
|
const Token* retval = ret->astOperand2();
|
|
// NRVO
|
|
if (retval->variable() && retval->variable()->isLocal() && !retval->variable()->isVolatile())
|
|
copyElisionError(retval);
|
|
// RVO
|
|
if (Token::Match(retval, "(|{") && !retval->isCast() && !(retval->valueType() && retval->valueType()->reference != Reference::None))
|
|
copyElisionError(retval);
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckFunctions::copyElisionError(const Token *tok)
|
|
{
|
|
reportError(tok,
|
|
Severity::performance,
|
|
"returnStdMoveLocal",
|
|
"Using std::move for returning object by-value from function will affect copy elision optimization."
|
|
" More: https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rf-return-move-local");
|
|
}
|