536 lines
19 KiB
C++
536 lines
19 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2016 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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#include "astutils.h"
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#include "library.h"
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#include "mathlib.h"
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#include "settings.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "valueflow.h"
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#include <list>
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static bool astIsCharWithSign(const Token *tok, ValueType::Sign sign)
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{
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if (!tok)
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return false;
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const ValueType *valueType = tok->valueType();
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if (!valueType)
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return false;
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return valueType->type == ValueType::Type::CHAR && valueType->pointer == 0U && valueType->sign == sign;
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}
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bool astIsSignedChar(const Token *tok)
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{
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return astIsCharWithSign(tok, ValueType::Sign::SIGNED);
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}
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bool astIsUnknownSignChar(const Token *tok)
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{
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return astIsCharWithSign(tok, ValueType::Sign::UNKNOWN_SIGN);
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}
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bool astIsIntegral(const Token *tok, bool unknown)
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{
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const ValueType *vt = tok ? tok->valueType() : nullptr;
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if (!vt)
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return unknown;
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return vt->isIntegral() && vt->pointer == 0U;
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}
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bool astIsFloat(const Token *tok, bool unknown)
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{
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const ValueType *vt = tok ? tok->valueType() : nullptr;
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if (!vt)
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return unknown;
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return vt->type >= ValueType::Type::FLOAT && vt->pointer == 0U;
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}
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bool astIsBool(const Token *tok)
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{
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return tok && (tok->isBoolean() || (tok->valueType() && tok->valueType()->type == ValueType::Type::BOOL && !tok->valueType()->pointer));
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}
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std::string astCanonicalType(const Token *expr)
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{
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if (!expr)
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return "";
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if (expr->variable()) {
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const Variable *var = expr->variable();
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std::string ret;
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for (const Token *type = var->typeStartToken(); Token::Match(type,"%name%|::") && type != var->nameToken(); type = type->next()) {
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if (!Token::Match(type, "const|static"))
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ret += type->str();
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}
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return ret;
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}
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// TODO: handle expressions
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return "";
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}
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static bool match(const Token *tok, const std::string &rhs)
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{
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if (tok->str() == rhs)
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return true;
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if (tok->isName() && !tok->varId() && tok->values().size() == 1U && tok->values().front().isKnown() && MathLib::toString(tok->values().front().intvalue) == rhs)
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return true;
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return false;
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}
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const Token * astIsVariableComparison(const Token *tok, const std::string &comp, const std::string &rhs, const Token **vartok)
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{
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if (!tok)
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return nullptr;
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const Token *ret = nullptr;
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if (tok->isComparisonOp()) {
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if (tok->astOperand1() && match(tok->astOperand1(), rhs)) {
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// Invert comparator
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std::string s = tok->str();
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if (s[0] == '>')
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s[0] = '<';
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else if (s[0] == '<')
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s[0] = '>';
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if (s == comp) {
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ret = tok->astOperand2();
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}
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} else if (tok->str() == comp && tok->astOperand2() && match(tok->astOperand2(), rhs)) {
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ret = tok->astOperand1();
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}
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} else if (comp == "!=" && rhs == std::string("0")) {
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ret = tok;
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} else if (comp == "==" && rhs == std::string("0")) {
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if (tok->str() == "!")
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ret = tok->astOperand1();
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}
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while (ret && ret->str() == ".")
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ret = ret->astOperand2();
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if (ret && ret->varId() == 0U)
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ret = nullptr;
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if (vartok)
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*vartok = ret;
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return ret;
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}
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bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure)
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{
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if (tok1 == nullptr && tok2 == nullptr)
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return true;
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if (tok1 == nullptr || tok2 == nullptr)
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return false;
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if (cpp) {
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if (tok1->str() == "." && tok1->astOperand1() && tok1->astOperand1()->str() == "this")
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tok1 = tok1->astOperand2();
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if (tok2->str() == "." && tok2->astOperand1() && tok2->astOperand1()->str() == "this")
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tok2 = tok2->astOperand2();
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}
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if (tok1->varId() != tok2->varId() || tok1->str() != tok2->str() || tok1->originalName() != tok2->originalName()) {
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if ((Token::Match(tok1,"<|>") && Token::Match(tok2,"<|>")) ||
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(Token::Match(tok1,"<=|>=") && Token::Match(tok2,"<=|>="))) {
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return isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure) &&
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isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure);
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}
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return false;
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}
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if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro()))
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return false;
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if (tok1->isComplex() != tok2->isComplex())
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return false;
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if (tok1->isLong() != tok2->isLong())
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return false;
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if (tok1->isUnsigned() != tok2->isUnsigned())
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return false;
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if (tok1->isSigned() != tok2->isSigned())
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return false;
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if (tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof") {
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if (!tok1->function() && !Token::Match(tok1->previous(), ".|::") && pure && !library.isFunctionConst(tok1->str(), true) && !tok1->isAttributeConst() && !tok1->isAttributePure())
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return false;
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else if (tok1->function() && !tok1->function()->isConst() && !tok1->function()->isAttributeConst() && !tok1->function()->isAttributePure())
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return false;
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}
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// templates/casts
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if ((Token::Match(tok1, "%name% <") && tok1->next()->link()) ||
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(Token::Match(tok2, "%name% <") && tok2->next()->link())) {
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// non-const template function that is not a dynamic_cast => return false
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if (Token::simpleMatch(tok1->next()->link(), "> (") &&
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!(tok1->function() && tok1->function()->isConst()) &&
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tok1->str() != "dynamic_cast")
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return false;
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// some template/cast stuff.. check that the template arguments are same
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const Token *t1 = tok1->next();
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const Token *t2 = tok2->next();
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const Token *end1 = t1->link();
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const Token *end2 = t2->link();
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while (t1 && t2 && t1 != end1 && t2 != end2) {
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if (t1->str() != t2->str())
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return false;
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t1 = t1->next();
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t2 = t2->next();
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}
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if (t1 != end1 || t2 != end2)
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return false;
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}
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if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
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return false;
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// bailout when we see ({..})
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if (tok1->str() == "{")
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return false;
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if (tok1->str() == "(" && tok1->previous() && !tok1->previous()->isName()) { // cast => assert that the casts are equal
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const Token *t1 = tok1->next();
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const Token *t2 = tok2->next();
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while (t1 && t2 &&
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t1->str() == t2->str() &&
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t1->isLong() == t2->isLong() &&
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t1->isUnsigned() == t2->isUnsigned() &&
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t1->isSigned() == t2->isSigned() &&
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(t1->isName() || t1->str() == "*")) {
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t1 = t1->next();
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t2 = t2->next();
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}
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if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
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return false;
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}
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bool noncommutativeEquals =
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isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand1(), library, pure);
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noncommutativeEquals = noncommutativeEquals &&
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isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand2(), library, pure);
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if (noncommutativeEquals)
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return true;
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// in c++, a+b might be different to b+a, depending on the type of a and b
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if (cpp && tok1->str() == "+" && tok1->astOperand2()) {
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const ValueType* vt1 = tok1->astOperand1()->valueType();
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const ValueType* vt2 = tok1->astOperand2()->valueType();
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if (!(vt1 && (vt1->type >= ValueType::VOID || vt1->pointer) && vt2 && (vt2->type >= ValueType::VOID || vt2->pointer)))
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return false;
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}
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const bool commutative = tok1->astOperand1() && tok1->astOperand2() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
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bool commutativeEquals = commutative &&
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isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure);
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commutativeEquals = commutativeEquals &&
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isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure);
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return commutativeEquals;
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}
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bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const Library& library, bool pure)
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{
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if (!cond1 || !cond2)
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return false;
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if (cond1->str() == "!") {
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if (cond2->str() == "!=") {
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if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
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return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure);
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if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
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return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure);
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}
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return isSameExpression(cpp, true, cond1->astOperand1(), cond2, library, pure);
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}
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if (cond2->str() == "!")
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return isOppositeCond(isNot, cpp, cond2, cond1, library, pure);
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if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
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return false;
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const std::string &comp1 = cond1->str();
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// condition found .. get comparator
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std::string comp2;
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if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure) &&
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isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure)) {
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comp2 = cond2->str();
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} else if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure) &&
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isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand1(), library, pure)) {
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comp2 = cond2->str();
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if (comp2[0] == '>')
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comp2[0] = '<';
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else if (comp2[0] == '<')
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comp2[0] = '>';
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}
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if (!isNot && comp2.empty()) {
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if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure) &&
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cond1->astOperand2() && cond1->astOperand2()->hasKnownIntValue() &&
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cond2->astOperand2() && cond2->astOperand2()->hasKnownIntValue()) {
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const ValueFlow::Value &rhsValue1 = cond1->astOperand2()->values().front();
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const ValueFlow::Value &rhsValue2 = cond2->astOperand2()->values().front();
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bool secondAlwaysFalse = false;
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if (comp1 == "<" || comp1 == "<=")
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secondAlwaysFalse = Token::Match(cond2, "==|>|>=") && (rhsValue1.intvalue < rhsValue2.intvalue);
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else if (comp1 == ">=" || comp1 == ">")
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secondAlwaysFalse = Token::Match(cond2, "==|<|<=") && (rhsValue1.intvalue > rhsValue2.intvalue);
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if (secondAlwaysFalse)
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return true;
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}
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}
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// is condition opposite?
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return ((comp1 == "==" && comp2 == "!=") ||
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(comp1 == "!=" && comp2 == "==") ||
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(comp1 == "<" && comp2 == ">=") ||
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(comp1 == "<=" && comp2 == ">") ||
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(comp1 == ">" && comp2 == "<=") ||
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(comp1 == ">=" && comp2 == "<") ||
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(!isNot && ((comp1 == "<" && comp2 == ">") ||
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(comp1 == ">" && comp2 == "<"))));
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}
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bool isConstExpression(const Token *tok, const Library& library, bool pure)
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{
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if (!tok)
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return true;
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if (tok->isName() && tok->next()->str() == "(") {
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if (!tok->function() && !Token::Match(tok->previous(), ".|::") && !library.isFunctionConst(tok->str(), pure))
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return false;
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else if (tok->function() && !tok->function()->isConst())
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return false;
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}
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if (tok->tokType() == Token::eIncDecOp)
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return false;
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// bailout when we see ({..})
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if (tok->str() == "{")
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return false;
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return isConstExpression(tok->astOperand1(), library, pure) && isConstExpression(tok->astOperand2(), library, pure);
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}
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bool isWithoutSideEffects(bool cpp, const Token* tok)
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{
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if (!cpp)
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return true;
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while (tok && tok->astOperand2() && tok->astOperand2()->str() != "(")
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tok = tok->astOperand2();
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if (tok && tok->varId()) {
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const Variable* var = tok->variable();
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return var && (!var->isClass() || var->isPointer() || var->isStlType());
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}
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return true;
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}
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bool isReturnScope(const Token * const endToken)
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{
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if (!endToken || endToken->str() != "}")
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return false;
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const Token *prev = endToken->previous();
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while (prev && Token::simpleMatch(prev->previous(), "; ;"))
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prev = prev->previous();
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if (prev && Token::simpleMatch(prev->previous(), "} ;"))
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prev = prev->previous();
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if (Token::simpleMatch(prev, "}")) {
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if (Token::simpleMatch(prev->link()->tokAt(-2), "} else {"))
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return isReturnScope(prev) && isReturnScope(prev->link()->tokAt(-2));
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if (Token::simpleMatch(prev->link()->previous(), ") {") &&
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Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "switch (") &&
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!Token::findsimplematch(prev->link(), "break", prev)) {
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return true;
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}
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if (Token::simpleMatch(prev->link()->previous(), ") {") &&
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Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "return (")) {
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return true;
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}
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if (Token::Match(prev->link()->previous(), "[;{}] {"))
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return isReturnScope(prev);
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} else if (Token::simpleMatch(prev, ";")) {
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// noreturn function
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if (Token::simpleMatch(prev->previous(), ") ;") && Token::Match(prev->linkAt(-1)->tokAt(-2), "[;{}] %name% ("))
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return true;
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// return/goto statement
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prev = prev->previous();
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while (prev && !Token::Match(prev, ";|{|}|return|goto|throw|continue|break"))
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prev = prev->previous();
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return prev && prev->isName();
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}
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return false;
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}
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bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings, bool *inconclusive)
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{
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if (!tok)
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return false;
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// address of variable
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const bool addressOf = tok && Token::simpleMatch(tok->previous(), "&");
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// passing variable to subfunction?
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if (Token::Match(tok->tokAt(-2), ") & %name% [,)]") && Token::Match(tok->linkAt(-2)->previous(), "[,(] ("))
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;
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else if (Token::Match(tok->tokAt(addressOf?-2:-1), "[(,] &| %name% [,)]"))
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;
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else
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return false;
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// reinterpret_cast etc..
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if (Token::Match(tok->tokAt(-3), "> ( & %name% ) [,)]") &&
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tok->linkAt(-3) &&
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Token::Match(tok->linkAt(-3)->tokAt(-2), "[,(] %type% <"))
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tok = tok->linkAt(-3);
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// goto start of function call and get argnr
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unsigned int argnr = 0;
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while (tok && tok->str() != "(") {
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if (tok->str() == ",")
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++argnr;
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else if (tok->str() == ")")
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tok = tok->link();
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tok = tok->previous();
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}
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tok = tok ? tok->previous() : nullptr;
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if (tok && tok->link() && tok->str() == ">")
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tok = tok->link()->previous();
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if (!Token::Match(tok, "%name% ("))
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return false; // not a function => variable not changed
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if (tok->varId())
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return false; // Constructor call of tok => variable probably not changed by constructor call
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if (!tok->function()) {
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// if the library says 0 is invalid
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// => it is assumed that parameter is an in parameter (TODO: this is a bad heuristic)
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if (!addressOf && settings->library.isnullargbad(tok, 1+argnr))
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return false;
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// addressOf => inconclusive
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if (!addressOf) {
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if (inconclusive != nullptr)
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*inconclusive = true;
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return false;
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}
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return true;
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}
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const Variable *arg = tok->function()->getArgumentVar(argnr);
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if (addressOf && !(arg && arg->isConst()))
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return true;
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return arg && !arg->isConst() && arg->isReference();
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}
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bool isVariableChanged(const Token *start, const Token *end, const unsigned int varid, bool globalvar, const Settings *settings)
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{
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for (const Token *tok = start; tok != end; tok = tok->next()) {
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if (tok->varId() != varid) {
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if (globalvar && Token::Match(tok, "%name% ("))
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// TODO: Is global variable really changed by function call?
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return true;
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continue;
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}
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if (Token::Match(tok, "%name% %assign%|++|--"))
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return true;
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if (Token::Match(tok->previous(), "++|-- %name%"))
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return true;
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if (Token::simpleMatch(tok->previous(), ">>")) {
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const Token *shr = tok->previous();
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if (Token::simpleMatch(shr->astParent(), ">>"))
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return true;
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const Token *lhs = shr->astOperand1();
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if (!lhs || !lhs->valueType() || !lhs->valueType()->isIntegral())
|
|
return true;
|
|
}
|
|
|
|
const Token *ftok = tok;
|
|
while (ftok && !Token::Match(ftok, "[({[]"))
|
|
ftok = ftok->astParent();
|
|
|
|
if (ftok && Token::Match(ftok->link(), ") !!{")) {
|
|
bool inconclusive = false;
|
|
bool isChanged = isVariableChangedByFunctionCall(tok, settings, &inconclusive);
|
|
isChanged |= inconclusive;
|
|
if (isChanged)
|
|
return true;
|
|
}
|
|
|
|
const Token *parent = tok->astParent();
|
|
while (Token::Match(parent, ".|::"))
|
|
parent = parent->astParent();
|
|
if (parent && parent->tokType() == Token::eIncDecOp)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
int numberOfArguments(const Token *start)
|
|
{
|
|
int arguments=0;
|
|
const Token* const openBracket = start->next();
|
|
if (openBracket && openBracket->str()=="(" && openBracket->next() && openBracket->next()->str()!=")") {
|
|
const Token* argument=openBracket->next();
|
|
while (argument) {
|
|
++arguments;
|
|
argument = argument->nextArgument();
|
|
}
|
|
}
|
|
return arguments;
|
|
}
|
|
|
|
static void getArgumentsRecursive(const Token *tok, std::vector<const Token *> *arguments)
|
|
{
|
|
if (!tok)
|
|
return;
|
|
if (tok->str() == ",") {
|
|
getArgumentsRecursive(tok->astOperand1(), arguments);
|
|
getArgumentsRecursive(tok->astOperand2(), arguments);
|
|
} else {
|
|
arguments->push_back(tok);
|
|
}
|
|
}
|
|
|
|
std::vector<const Token *> getArguments(const Token *ftok)
|
|
{
|
|
std::vector<const Token *> arguments;
|
|
getArgumentsRecursive(ftok->next()->astOperand2(), &arguments);
|
|
return arguments;
|
|
}
|
|
|
|
const Token *findLambdaEndToken(const Token *first)
|
|
{
|
|
if (!first || first->str() != "[")
|
|
return nullptr;
|
|
const Token* tok = first->link();
|
|
if (Token::simpleMatch(tok, "] {"))
|
|
return tok->linkAt(1);
|
|
if (!Token::simpleMatch(tok, "] ("))
|
|
return nullptr;
|
|
tok = tok->linkAt(1)->next();
|
|
if (tok && tok->str() == "constexpr")
|
|
tok = tok->next();
|
|
if (tok && tok->str() == "mutable")
|
|
tok = tok->next();
|
|
if (tok && tok->str() == "{")
|
|
return tok->link();
|
|
return nullptr;
|
|
}
|