469 lines
19 KiB
C++
469 lines
19 KiB
C++
/*
|
|
* Cppcheck - A tool for static C/C++ code analysis
|
|
* Copyright (C) 2007-2020 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 "checkbool.h"
|
|
|
|
#include "astutils.h"
|
|
#include "mathlib.h"
|
|
#include "settings.h"
|
|
#include "symboldatabase.h"
|
|
#include "token.h"
|
|
#include "tokenize.h"
|
|
|
|
#include <cstddef>
|
|
#include <list>
|
|
//---------------------------------------------------------------------------
|
|
|
|
// Register this check class (by creating a static instance of it)
|
|
namespace {
|
|
CheckBool instance;
|
|
}
|
|
|
|
static const CWE CWE398(398U); // Indicator of Poor Code Quality
|
|
static const CWE CWE571(571U); // Expression is Always True
|
|
static const CWE CWE587(587U); // Assignment of a Fixed Address to a Pointer
|
|
static const CWE CWE704(704U); // Incorrect Type Conversion or Cast
|
|
|
|
static bool isBool(const Variable* var)
|
|
{
|
|
return (var && Token::Match(var->typeEndToken(), "bool|_Bool"));
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
void CheckBool::checkIncrementBoolean()
|
|
{
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
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 (astIsBool(tok) && tok->astParent() && tok->astParent()->str() == "++") {
|
|
incrementBooleanError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::incrementBooleanError(const Token *tok)
|
|
{
|
|
reportError(
|
|
tok,
|
|
Severity::style,
|
|
"incrementboolean",
|
|
"Incrementing a variable of type 'bool' with postfix operator++ is deprecated by the C++ Standard. You should assign it the value 'true' instead.\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. You should assign it the value 'true' instead.",
|
|
CWE398, Certainty::normal
|
|
);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// if (bool & bool) -> if (bool && bool)
|
|
// if (bool | bool) -> if (bool || bool)
|
|
//---------------------------------------------------------------------------
|
|
void CheckBool::checkBitwiseOnBoolean()
|
|
{
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
return;
|
|
|
|
// danmar: this is inconclusive because I don't like that there are
|
|
// warnings for calculations. Example: set_flag(a & b);
|
|
if (!mSettings->certainty.isEnabled(Certainty::inconclusive))
|
|
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 (tok->isBinaryOp() && (tok->str() == "&" || tok->str() == "|")) {
|
|
if (astIsBool(tok->astOperand1()) || astIsBool(tok->astOperand2())) {
|
|
if (tok->astOperand2()->variable() && tok->astOperand2()->variable()->nameToken() == tok->astOperand2())
|
|
continue;
|
|
const std::string expression = astIsBool(tok->astOperand1()) ? tok->astOperand1()->expressionString() : tok->astOperand2()->expressionString();
|
|
bitwiseOnBooleanError(tok, expression, tok->str() == "&" ? "&&" : "||");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::bitwiseOnBooleanError(const Token *tok, const std::string &expression, const std::string &op)
|
|
{
|
|
reportError(tok, Severity::style, "bitwiseOnBoolean",
|
|
"Boolean expression '" + expression + "' is used in bitwise operation. Did you mean '" + op + "'?",
|
|
CWE398,
|
|
Certainty::inconclusive);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// if (!x==3) <- Probably meant to be "x!=3"
|
|
//---------------------------------------------------------------------------
|
|
|
|
void CheckBool::checkComparisonOfBoolWithInt()
|
|
{
|
|
if (!mSettings->severity.isEnabled(Severity::warning) || !mTokenizer->isCPP())
|
|
return;
|
|
|
|
const SymbolDatabase* const symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (!tok->isComparisonOp() || !tok->isBinaryOp())
|
|
continue;
|
|
const Token* const left = tok->astOperand1();
|
|
const Token* const right = tok->astOperand2();
|
|
if (left->isBoolean() && right->varId()) { // Comparing boolean constant with variable
|
|
if (tok->str() != "==" && tok->str() != "!=") {
|
|
comparisonOfBoolWithInvalidComparator(right, left->str());
|
|
}
|
|
} else if (left->varId() && right->isBoolean()) { // Comparing variable with boolean constant
|
|
if (tok->str() != "==" && tok->str() != "!=") {
|
|
comparisonOfBoolWithInvalidComparator(right, left->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::comparisonOfBoolWithInvalidComparator(const Token *tok, const std::string &expression)
|
|
{
|
|
reportError(tok, Severity::warning, "comparisonOfBoolWithInvalidComparator",
|
|
"Comparison of a boolean value using relational operator (<, >, <= or >=).\n"
|
|
"The result of the expression '" + expression + "' is of type 'bool'. "
|
|
"Comparing 'bool' value using relational (<, >, <= or >=)"
|
|
" operator could cause unexpected results.");
|
|
}
|
|
|
|
//-------------------------------------------------------------------------------
|
|
// Comparing functions which are returning value of type bool
|
|
//-------------------------------------------------------------------------------
|
|
|
|
static bool tokenIsFunctionReturningBool(const Token* tok)
|
|
{
|
|
const Function* func = tok->function();
|
|
if (func && Token::Match(tok, "%name% (")) {
|
|
if (func->tokenDef && Token::Match(func->tokenDef->previous(), "bool|_Bool")) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void CheckBool::checkComparisonOfFuncReturningBool()
|
|
{
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
return;
|
|
|
|
if (!mTokenizer->isCPP())
|
|
return;
|
|
|
|
const SymbolDatabase * const symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (!tok->isComparisonOp() || tok->str() == "==" || tok->str() == "!=")
|
|
continue;
|
|
const Token *firstToken = tok->previous();
|
|
if (tok->strAt(-1) == ")") {
|
|
firstToken = firstToken->link()->previous();
|
|
}
|
|
const Token *secondToken = tok->next();
|
|
while (secondToken->str() == "!") {
|
|
secondToken = secondToken->next();
|
|
}
|
|
const bool firstIsFunctionReturningBool = tokenIsFunctionReturningBool(firstToken);
|
|
const bool secondIsFunctionReturningBool = tokenIsFunctionReturningBool(secondToken);
|
|
if (firstIsFunctionReturningBool && secondIsFunctionReturningBool) {
|
|
comparisonOfTwoFuncsReturningBoolError(firstToken->next(), firstToken->str(), secondToken->str());
|
|
} else if (firstIsFunctionReturningBool) {
|
|
comparisonOfFuncReturningBoolError(firstToken->next(), firstToken->str());
|
|
} else if (secondIsFunctionReturningBool) {
|
|
comparisonOfFuncReturningBoolError(secondToken->previous(), secondToken->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::comparisonOfFuncReturningBoolError(const Token *tok, const std::string &expression)
|
|
{
|
|
reportError(tok, Severity::style, "comparisonOfFuncReturningBoolError",
|
|
"Comparison of a function returning boolean value using relational (<, >, <= or >=) operator.\n"
|
|
"The return type of function '" + expression + "' is 'bool' "
|
|
"and result is of type 'bool'. Comparing 'bool' value using relational (<, >, <= or >=)"
|
|
" operator could cause unexpected results.", CWE398, Certainty::normal);
|
|
}
|
|
|
|
void CheckBool::comparisonOfTwoFuncsReturningBoolError(const Token *tok, const std::string &expression1, const std::string &expression2)
|
|
{
|
|
reportError(tok, Severity::style, "comparisonOfTwoFuncsReturningBoolError",
|
|
"Comparison of two functions returning boolean value using relational (<, >, <= or >=) operator.\n"
|
|
"The return type of function '" + expression1 + "' and function '" + expression2 + "' is 'bool' "
|
|
"and result is of type 'bool'. Comparing 'bool' value using relational (<, >, <= or >=)"
|
|
" operator could cause unexpected results.", CWE398, Certainty::normal);
|
|
}
|
|
|
|
//-------------------------------------------------------------------------------
|
|
// Comparison of bool with bool
|
|
//-------------------------------------------------------------------------------
|
|
|
|
void CheckBool::checkComparisonOfBoolWithBool()
|
|
{
|
|
// FIXME: This checking is "experimental" because of the false positives
|
|
// when self checking lib/tokenize.cpp (#2617)
|
|
if (!mSettings->certainty.isEnabled(Certainty::experimental))
|
|
return;
|
|
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
return;
|
|
|
|
if (!mTokenizer->isCPP())
|
|
return;
|
|
|
|
const SymbolDatabase* const symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (!tok->isComparisonOp() || tok->str() == "==" || tok->str() == "!=")
|
|
continue;
|
|
bool firstTokenBool = false;
|
|
|
|
const Token *firstToken = tok->previous();
|
|
if (firstToken->varId()) {
|
|
if (isBool(firstToken->variable())) {
|
|
firstTokenBool = true;
|
|
}
|
|
}
|
|
if (!firstTokenBool)
|
|
continue;
|
|
|
|
bool secondTokenBool = false;
|
|
const Token *secondToken = tok->next();
|
|
if (secondToken->varId()) {
|
|
if (isBool(secondToken->variable())) {
|
|
secondTokenBool = true;
|
|
}
|
|
}
|
|
if (secondTokenBool) {
|
|
comparisonOfBoolWithBoolError(firstToken->next(), secondToken->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::comparisonOfBoolWithBoolError(const Token *tok, const std::string &expression)
|
|
{
|
|
reportError(tok, Severity::style, "comparisonOfBoolWithBoolError",
|
|
"Comparison of a variable having boolean value using relational (<, >, <= or >=) operator.\n"
|
|
"The variable '" + expression + "' is of type 'bool' "
|
|
"and comparing 'bool' value using relational (<, >, <= or >=)"
|
|
" operator could cause unexpected results.", CWE398, Certainty::normal);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
void CheckBool::checkAssignBoolToPointer()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (tok->str() == "=" && astIsPointer(tok->astOperand1()) && astIsBool(tok->astOperand2())) {
|
|
assignBoolToPointerError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::assignBoolToPointerError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::error, "assignBoolToPointer",
|
|
"Boolean value assigned to pointer.", CWE587, Certainty::normal);
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
//-----------------------------------------------------------------------------
|
|
void CheckBool::checkComparisonOfBoolExpressionWithInt()
|
|
{
|
|
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 (!tok->isComparisonOp())
|
|
continue;
|
|
|
|
const Token* numTok = nullptr;
|
|
const Token* boolExpr = nullptr;
|
|
bool numInRhs;
|
|
if (astIsBool(tok->astOperand1())) {
|
|
boolExpr = tok->astOperand1();
|
|
numTok = tok->astOperand2();
|
|
numInRhs = true;
|
|
} else if (astIsBool(tok->astOperand2())) {
|
|
boolExpr = tok->astOperand2();
|
|
numTok = tok->astOperand1();
|
|
numInRhs = false;
|
|
} else {
|
|
continue;
|
|
}
|
|
|
|
if (!numTok || !boolExpr)
|
|
continue;
|
|
|
|
if (boolExpr->isOp() && numTok->isName() && Token::Match(tok, "==|!="))
|
|
// there is weird code such as: ((a<b)==c)
|
|
// but it is probably written this way by design.
|
|
continue;
|
|
|
|
if (astIsBool(numTok))
|
|
continue;
|
|
|
|
const ValueFlow::Value *minval = numTok->getValueLE(0, mSettings);
|
|
if (minval && minval->intvalue == 0 &&
|
|
(numInRhs ? Token::Match(tok, ">|==|!=")
|
|
: Token::Match(tok, "<|==|!=")))
|
|
minval = nullptr;
|
|
|
|
const ValueFlow::Value *maxval = numTok->getValueGE(1, mSettings);
|
|
if (maxval && maxval->intvalue == 1 &&
|
|
(numInRhs ? Token::Match(tok, "<|==|!=")
|
|
: Token::Match(tok, ">|==|!=")))
|
|
maxval = nullptr;
|
|
|
|
if (minval || maxval) {
|
|
bool not0or1 = (minval && minval->intvalue < 0) || (maxval && maxval->intvalue > 1);
|
|
comparisonOfBoolExpressionWithIntError(tok, not0or1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::comparisonOfBoolExpressionWithIntError(const Token *tok, bool not0or1)
|
|
{
|
|
if (not0or1)
|
|
reportError(tok, Severity::warning, "compareBoolExpressionWithInt",
|
|
"Comparison of a boolean expression with an integer other than 0 or 1.", CWE398, Certainty::normal);
|
|
else
|
|
reportError(tok, Severity::warning, "compareBoolExpressionWithInt",
|
|
"Comparison of a boolean expression with an integer.", CWE398, Certainty::normal);
|
|
}
|
|
|
|
|
|
void CheckBool::pointerArithBool()
|
|
{
|
|
const SymbolDatabase* symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
for (const Scope &scope : symbolDatabase->scopeList) {
|
|
if (scope.type != Scope::eIf && !scope.isLoopScope())
|
|
continue;
|
|
const Token* tok = scope.classDef->next()->astOperand2();
|
|
if (scope.type == Scope::eFor) {
|
|
tok = Token::findsimplematch(scope.classDef->tokAt(2), ";");
|
|
if (tok)
|
|
tok = tok->astOperand2();
|
|
if (tok)
|
|
tok = tok->astOperand1();
|
|
} else if (scope.type == Scope::eDo)
|
|
tok = (scope.bodyEnd->tokAt(2)) ? scope.bodyEnd->tokAt(2)->astOperand2() : nullptr;
|
|
|
|
pointerArithBoolCond(tok);
|
|
}
|
|
}
|
|
|
|
void CheckBool::pointerArithBoolCond(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return;
|
|
if (Token::Match(tok, "&&|%oror%")) {
|
|
pointerArithBoolCond(tok->astOperand1());
|
|
pointerArithBoolCond(tok->astOperand2());
|
|
return;
|
|
}
|
|
if (tok->str() != "+" && tok->str() != "-")
|
|
return;
|
|
|
|
if (tok->isBinaryOp() &&
|
|
tok->astOperand1()->isName() &&
|
|
tok->astOperand1()->variable() &&
|
|
tok->astOperand1()->variable()->isPointer() &&
|
|
tok->astOperand2()->isNumber())
|
|
pointerArithBoolError(tok);
|
|
}
|
|
|
|
void CheckBool::pointerArithBoolError(const Token *tok)
|
|
{
|
|
reportError(tok,
|
|
Severity::error,
|
|
"pointerArithBool",
|
|
"Converting pointer arithmetic result to bool. The bool is always true unless there is undefined behaviour.\n"
|
|
"Converting pointer arithmetic result to bool. The boolean result is always true unless there is pointer arithmetic overflow, and overflow is undefined behaviour. Probably a dereference is forgotten.", CWE571, Certainty::normal);
|
|
}
|
|
|
|
void CheckBool::checkAssignBoolToFloat()
|
|
{
|
|
if (!mTokenizer->isCPP())
|
|
return;
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
return;
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
for (const Token* tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (tok->str() == "=" && astIsFloat(tok->astOperand1(), false) && astIsBool(tok->astOperand2())) {
|
|
assignBoolToFloatError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::assignBoolToFloatError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::style, "assignBoolToFloat",
|
|
"Boolean value assigned to floating point variable.", CWE704, Certainty::normal);
|
|
}
|
|
|
|
void CheckBool::returnValueOfFunctionReturningBool()
|
|
{
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
return;
|
|
|
|
const SymbolDatabase * const symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
if (!(scope->function && Token::Match(scope->function->retDef, "bool|_Bool")))
|
|
continue;
|
|
|
|
for (const Token* tok = scope->bodyStart->next(); tok && (tok != scope->bodyEnd); tok = tok->next()) {
|
|
// Skip lambdas
|
|
const Token* tok2 = findLambdaEndToken(tok);
|
|
if (tok2)
|
|
tok = tok2;
|
|
else if (tok->scope() && tok->scope()->isClassOrStruct())
|
|
tok = tok->scope()->bodyEnd;
|
|
else if (Token::simpleMatch(tok, "return") && tok->astOperand1() &&
|
|
(tok->astOperand1()->getValueGE(2, mSettings) || tok->astOperand1()->getValueLE(-1, mSettings)) &&
|
|
!(tok->astOperand1()->astOperand1() && Token::Match(tok->astOperand1(), "&|%or%")))
|
|
returnValueBoolError(tok);
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckBool::returnValueBoolError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::style, "returnNonBoolInBooleanFunction", "Non-boolean value returned from function returning bool");
|
|
}
|