2730 lines
103 KiB
C++
2730 lines
103 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2020 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 "config.h"
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#include "errortypes.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 <algorithm>
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#include <functional>
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#include <iterator>
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#include <list>
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#include <stack>
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#include <utility>
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template<class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*>)>
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void visitAstNodesGeneric(T *ast, std::function<ChildrenToVisit(T *)> visitor)
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{
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std::stack<T *> tokens;
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tokens.push(ast);
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while (!tokens.empty()) {
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T *tok = tokens.top();
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tokens.pop();
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if (!tok)
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continue;
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ChildrenToVisit c = visitor(tok);
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if (c == ChildrenToVisit::done)
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break;
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if (c == ChildrenToVisit::op1 || c == ChildrenToVisit::op1_and_op2)
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tokens.push(tok->astOperand1());
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if (c == ChildrenToVisit::op2 || c == ChildrenToVisit::op1_and_op2)
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tokens.push(tok->astOperand2());
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}
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}
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void visitAstNodes(const Token *ast, std::function<ChildrenToVisit(const Token *)> visitor)
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{
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visitAstNodesGeneric(ast, std::move(visitor));
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}
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void visitAstNodes(Token *ast, std::function<ChildrenToVisit(Token *)> visitor)
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{
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visitAstNodesGeneric(ast, std::move(visitor));
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}
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const Token* findAstNode(const Token* ast, const std::function<bool(const Token*)>& pred)
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{
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const Token* result = nullptr;
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visitAstNodes(ast, [&](const Token* tok) {
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if (pred(tok)) {
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result = tok;
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return ChildrenToVisit::done;
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}
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return ChildrenToVisit::op1_and_op2;
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});
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return result;
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}
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static void astFlattenRecursive(const Token *tok, std::vector<const Token *> *result, const char* op, nonneg int depth = 0)
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{
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++depth;
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if (!tok || depth >= 100)
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return;
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if (tok->str() == op) {
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astFlattenRecursive(tok->astOperand1(), result, op, depth);
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astFlattenRecursive(tok->astOperand2(), result, op, depth);
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} else {
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result->push_back(tok);
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}
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}
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std::vector<const Token*> astFlatten(const Token* tok, const char* op)
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{
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std::vector<const Token*> result;
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astFlattenRecursive(tok, &result, op);
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return result;
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}
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bool astHasToken(const Token* root, const Token * tok)
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{
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if (!root)
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return false;
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if (root == tok)
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return true;
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return astHasToken(root->astOperand1(), tok) || astHasToken(root->astOperand2(), tok);
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}
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bool astHasVar(const Token * tok, nonneg int varid)
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{
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if (!tok)
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return false;
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if (tok->varId() == varid)
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return true;
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return astHasVar(tok->astOperand1(), varid) || astHasVar(tok->astOperand2(), varid);
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}
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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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bool astIsPointer(const Token *tok)
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{
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return tok && tok->valueType() && tok->valueType()->pointer;
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}
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bool astIsSmartPointer(const Token* tok)
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{
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return tok && tok->valueType() && tok->valueType()->smartPointerTypeToken;
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}
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bool astIsIterator(const Token *tok)
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{
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return tok && tok->valueType() && tok->valueType()->type == ValueType::Type::ITERATOR;
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}
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bool astIsContainer(const Token *tok)
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{
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return getLibraryContainer(tok) != nullptr && tok->valueType()->type != ValueType::Type::ITERATOR;
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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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std::pair<const Token*, const Token*> decl = Token::typeDecl(expr);
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if (decl.first && decl.second) {
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std::string ret;
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for (const Token *type = decl.first; Token::Match(type,"%name%|::") && type != decl.second; 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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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->varId() && tok->hasKnownIntValue() && 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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if (tok->str() == "!") {
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ret = tok->astOperand1();
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// handle (!(x==0)) as (x!=0)
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astIsVariableComparison(ret, "==", "0", &ret);
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} else
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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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// handle (!(x!=0)) as (x==0)
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astIsVariableComparison(ret, "!=", "0", &ret);
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}
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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->str() == "=" && ret->astOperand1() && ret->astOperand1()->varId())
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ret = ret->astOperand1();
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else 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 isTemporary(bool cpp, const Token* tok, const Library* library, bool unknown)
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{
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if (!tok)
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return false;
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if (Token::simpleMatch(tok, "."))
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return (tok->originalName() != "->" && isTemporary(cpp, tok->astOperand1(), library)) ||
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isTemporary(cpp, tok->astOperand2(), library);
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if (Token::Match(tok, ",|::"))
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return isTemporary(cpp, tok->astOperand2(), library);
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if (tok->isCast() || (cpp && isCPPCast(tok)))
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return isTemporary(cpp, tok->astOperand2(), library);
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if (Token::Match(tok, "?|.|[|++|--|%name%|%assign%"))
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return false;
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if (tok->isUnaryOp("*"))
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return false;
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if (Token::Match(tok, "&|<<|>>") && isLikelyStream(cpp, tok->astOperand1()))
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return false;
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if (Token::simpleMatch(tok, "(") && tok->astOperand1() &&
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(tok->astOperand2() || Token::simpleMatch(tok->next(), ")"))) {
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if (tok->valueType()) {
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return tok->valueType()->reference == Reference::None;
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}
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const Token* ftok = nullptr;
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if (Token::simpleMatch(tok->previous(), ">") && tok->previous()->link())
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ftok = tok->previous()->link()->previous();
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else
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ftok = tok->previous();
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if (!ftok)
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return false;
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if (const Function * f = ftok->function()) {
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return !Function::returnsReference(f, true);
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} else if (library) {
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std::string returnType = library->returnValueType(ftok);
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return !returnType.empty() && returnType.back() != '&';
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} else {
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return unknown;
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}
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}
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if (tok->isCast())
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return false;
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// Currying a function is unknown in cppcheck
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if (Token::simpleMatch(tok, "(") && Token::simpleMatch(tok->astOperand1(), "("))
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return unknown;
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if (Token::simpleMatch(tok, "{") && Token::simpleMatch(tok->astParent(), "return") && tok->astOperand1() &&
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!tok->astOperand2())
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return isTemporary(cpp, tok->astOperand1(), library);
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return true;
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}
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static bool isFunctionCall(const Token* tok)
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{
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if (Token::Match(tok, "%name% ("))
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return true;
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if (Token::Match(tok, "%name% <") && Token::simpleMatch(tok->next()->link(), "> ("))
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return true;
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if (Token::Match(tok, "%name% ::"))
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return isFunctionCall(tok->tokAt(2));
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return false;
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}
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static bool hasToken(const Token * startTok, const Token * stopTok, const Token * tok)
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{
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for (const Token * tok2 = startTok; tok2 != stopTok; tok2 = tok2->next()) {
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if (tok2 == tok)
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return true;
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}
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return false;
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}
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template <class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*>)>
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static T* previousBeforeAstLeftmostLeafGeneric(T* tok)
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{
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T* leftmostLeaf = tok;
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while (leftmostLeaf && leftmostLeaf->astOperand1())
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leftmostLeaf = leftmostLeaf->astOperand1();
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return leftmostLeaf->previous();
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}
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const Token* previousBeforeAstLeftmostLeaf(const Token* tok)
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{
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return previousBeforeAstLeftmostLeafGeneric(tok);
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}
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Token* previousBeforeAstLeftmostLeaf(Token* tok)
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{
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return previousBeforeAstLeftmostLeafGeneric(tok);
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}
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template <class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*>)>
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static T* nextAfterAstRightmostLeafGeneric(T* tok)
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{
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const Token * rightmostLeaf = tok;
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if (!rightmostLeaf || !rightmostLeaf->astOperand1())
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return nullptr;
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do {
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if (const Token* lam = findLambdaEndToken(rightmostLeaf)) {
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rightmostLeaf = lam;
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break;
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}
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if (rightmostLeaf->astOperand2())
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rightmostLeaf = rightmostLeaf->astOperand2();
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else
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rightmostLeaf = rightmostLeaf->astOperand1();
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} while (rightmostLeaf->astOperand1());
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while (Token::Match(rightmostLeaf->next(), "]|)") && !hasToken(rightmostLeaf->next()->link(), rightmostLeaf->next(), tok))
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rightmostLeaf = rightmostLeaf->next();
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if (rightmostLeaf->str() == "{" && rightmostLeaf->link())
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rightmostLeaf = rightmostLeaf->link();
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return rightmostLeaf->next();
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}
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const Token* nextAfterAstRightmostLeaf(const Token* tok)
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{
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return nextAfterAstRightmostLeafGeneric(tok);
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}
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Token* nextAfterAstRightmostLeaf(Token* tok)
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{
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return nextAfterAstRightmostLeafGeneric(tok);
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}
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const Token* astParentSkipParens(const Token* tok)
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{
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return astParentSkipParens(const_cast<Token*>(tok));
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}
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Token* astParentSkipParens(Token* tok)
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{
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if (!tok)
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return nullptr;
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Token * parent = tok->astParent();
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if (!Token::simpleMatch(parent, "("))
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return parent;
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if (parent->link() != nextAfterAstRightmostLeaf(tok))
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return parent;
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return astParentSkipParens(parent);
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}
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const Token* getParentMember(const Token * tok)
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{
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if (!tok)
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return tok;
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const Token * parent = tok->astParent();
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if (!Token::simpleMatch(parent, "."))
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return tok;
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if (tok == parent->astOperand2())
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return parent->astOperand1();
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const Token * gparent = parent->astParent();
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if (!Token::simpleMatch(gparent, ".") || gparent->astOperand2() != parent)
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return tok;
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if (gparent->astOperand1())
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return gparent->astOperand1();
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return tok;
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}
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const Token* getParentLifetime(const Token* tok)
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{
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if (!tok)
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return tok;
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const Variable* var = tok->variable();
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// TODO: Call getLifetimeVariable for deeper analysis
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if (!var)
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return tok;
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if (var->isLocal() || var->isArgument())
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return tok;
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const Token* parent = getParentMember(tok);
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if (parent != tok)
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return getParentLifetime(parent);
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return tok;
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}
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bool astIsLHS(const Token* tok)
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{
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if (!tok)
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return false;
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const Token* parent = tok->astParent();
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if (!parent)
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return false;
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if (!parent->astOperand1())
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return false;
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if (!parent->astOperand2())
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return false;
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return parent->astOperand1() == tok;
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}
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bool astIsRHS(const Token* tok)
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{
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if (!tok)
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return false;
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const Token* parent = tok->astParent();
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if (!parent)
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return false;
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if (!parent->astOperand1())
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return false;
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if (!parent->astOperand2())
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return false;
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return parent->astOperand2() == tok;
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}
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template <class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*>)>
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static T* getCondTokImpl(T* tok)
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{
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if (!tok)
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return nullptr;
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if (Token::simpleMatch(tok, "("))
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return getCondTok(tok->previous());
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if (Token::simpleMatch(tok, "for") && Token::simpleMatch(tok->next()->astOperand2(), ";") &&
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tok->next()->astOperand2()->astOperand2())
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return tok->next()->astOperand2()->astOperand2()->astOperand1();
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if (Token::simpleMatch(tok->next()->astOperand2(), ";"))
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return tok->next()->astOperand2()->astOperand1();
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return tok->next()->astOperand2();
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}
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template <class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*>)>
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static T* getCondTokFromEndImpl(T* endBlock)
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{
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if (!Token::simpleMatch(endBlock, "}"))
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return nullptr;
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T* startBlock = endBlock->link();
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if (!Token::simpleMatch(startBlock, "{"))
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return nullptr;
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if (Token::simpleMatch(startBlock->previous(), ")")) {
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return getCondTok(startBlock->previous()->link());
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} else if (Token::simpleMatch(startBlock->tokAt(-2), "} else {")) {
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return getCondTokFromEnd(startBlock->tokAt(-2));
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}
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return nullptr;
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}
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Token* getCondTok(Token* tok)
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{
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return getCondTokImpl(tok);
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}
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const Token* getCondTok(const Token* tok)
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{
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return getCondTokImpl(tok);
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}
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Token* getCondTokFromEnd(Token* endBlock)
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{
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return getCondTokFromEndImpl(endBlock);
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}
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const Token* getCondTokFromEnd(const Token* endBlock)
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{
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return getCondTokFromEndImpl(endBlock);
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}
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const Token *findNextTokenFromBreak(const Token *breakToken)
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{
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const Scope *scope = breakToken->scope();
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while (scope) {
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if (scope->isLoopScope() || scope->type == Scope::ScopeType::eSwitch) {
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if (scope->type == Scope::ScopeType::eDo && Token::simpleMatch(scope->bodyEnd, "} while ("))
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return scope->bodyEnd->linkAt(2)->next();
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return scope->bodyEnd;
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}
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scope = scope->nestedIn;
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}
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return nullptr;
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}
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bool extractForLoopValues(const Token *forToken,
|
|
nonneg int * const varid,
|
|
bool * const knownInitValue,
|
|
MathLib::bigint * const initValue,
|
|
bool * const partialCond,
|
|
MathLib::bigint * const stepValue,
|
|
MathLib::bigint * const lastValue)
|
|
{
|
|
if (!Token::simpleMatch(forToken, "for (") || !Token::simpleMatch(forToken->next()->astOperand2(), ";"))
|
|
return false;
|
|
const Token *initExpr = forToken->next()->astOperand2()->astOperand1();
|
|
const Token *condExpr = forToken->next()->astOperand2()->astOperand2()->astOperand1();
|
|
const Token *incExpr = forToken->next()->astOperand2()->astOperand2()->astOperand2();
|
|
if (!initExpr || !initExpr->isBinaryOp() || initExpr->str() != "=" || !Token::Match(initExpr->astOperand1(), "%var%"))
|
|
return false;
|
|
*varid = initExpr->astOperand1()->varId();
|
|
*knownInitValue = initExpr->astOperand2()->hasKnownIntValue();
|
|
*initValue = (*knownInitValue) ? initExpr->astOperand2()->getKnownIntValue() : 0;
|
|
*partialCond = Token::Match(condExpr, "%oror%|&&");
|
|
visitAstNodes(condExpr, [varid, &condExpr](const Token *tok) {
|
|
if (Token::Match(tok, "%oror%|&&"))
|
|
return ChildrenToVisit::op1_and_op2;
|
|
if (Token::Match(tok, "<|<=") && tok->isBinaryOp() && tok->astOperand1()->varId() == *varid && tok->astOperand2()->hasKnownIntValue()) {
|
|
if (Token::Match(condExpr, "%oror%|&&") || tok->astOperand2()->getKnownIntValue() < condExpr->astOperand2()->getKnownIntValue())
|
|
condExpr = tok;
|
|
}
|
|
return ChildrenToVisit::none;
|
|
});
|
|
if (!Token::Match(condExpr, "<|<=") || !condExpr->isBinaryOp() || condExpr->astOperand1()->varId() != *varid || !condExpr->astOperand2()->hasKnownIntValue())
|
|
return false;
|
|
if (!incExpr || !incExpr->isUnaryOp("++") || incExpr->astOperand1()->varId() != *varid)
|
|
return false;
|
|
*stepValue = 1;
|
|
if (condExpr->str() == "<")
|
|
*lastValue = condExpr->astOperand2()->getKnownIntValue() - 1;
|
|
else
|
|
*lastValue = condExpr->astOperand2()->getKnownIntValue();
|
|
return true;
|
|
}
|
|
|
|
|
|
static const Token * getVariableInitExpression(const Variable * var)
|
|
{
|
|
if (!var)
|
|
return nullptr;
|
|
const Token *varDeclEndToken = var->declEndToken();
|
|
if (!varDeclEndToken)
|
|
return nullptr;
|
|
if (Token::Match(varDeclEndToken, "; %varid% =", var->declarationId()))
|
|
return varDeclEndToken->tokAt(2)->astOperand2();
|
|
return varDeclEndToken->astOperand2();
|
|
}
|
|
|
|
static bool isInLoopCondition(const Token * tok)
|
|
{
|
|
return Token::Match(tok->astTop()->previous(), "for|while (");
|
|
}
|
|
|
|
/// If tok2 comes after tok1
|
|
bool precedes(const Token * tok1, const Token * tok2)
|
|
{
|
|
if (!tok1)
|
|
return false;
|
|
if (!tok2)
|
|
return false;
|
|
return tok1->index() < tok2->index();
|
|
}
|
|
|
|
bool isAliasOf(const Token *tok, nonneg int varid, bool* inconclusive)
|
|
{
|
|
if (tok->varId() == varid)
|
|
return false;
|
|
for (const ValueFlow::Value &val : tok->values()) {
|
|
if (!val.isLocalLifetimeValue())
|
|
continue;
|
|
if (val.tokvalue->varId() == varid) {
|
|
if (val.isInconclusive()) {
|
|
if (inconclusive)
|
|
*inconclusive = true;
|
|
else
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool isAliased(const Token *startTok, const Token *endTok, nonneg int varid)
|
|
{
|
|
if (!precedes(startTok, endTok))
|
|
return false;
|
|
for (const Token *tok = startTok; tok != endTok; tok = tok->next()) {
|
|
if (Token::Match(tok, "= & %varid% ;", varid))
|
|
return true;
|
|
if (isAliasOf(tok, varid))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isAliased(const Variable *var)
|
|
{
|
|
if (!var)
|
|
return false;
|
|
if (!var->scope())
|
|
return false;
|
|
const Token *start = var->declEndToken();
|
|
if (!start)
|
|
return false;
|
|
return isAliased(start, var->scope()->bodyEnd, var->declarationId());
|
|
}
|
|
|
|
bool exprDependsOnThis(const Token* expr, nonneg int depth)
|
|
{
|
|
if (!expr)
|
|
return false;
|
|
if (depth >= 1000)
|
|
// Abort recursion to avoid stack overflow
|
|
return true;
|
|
++depth;
|
|
// calling nonstatic method?
|
|
if (Token::Match(expr->previous(), "!!:: %name% (") && expr->function() && expr->function()->nestedIn && expr->function()->nestedIn->isClassOrStruct()) {
|
|
// is it a method of this?
|
|
const Scope* fScope = expr->scope();
|
|
while (!fScope->functionOf && fScope->nestedIn)
|
|
fScope = fScope->nestedIn;
|
|
const Scope* nestedIn = fScope->functionOf;
|
|
if (nestedIn && nestedIn->function)
|
|
nestedIn = nestedIn->function->token->scope();
|
|
while (nestedIn && nestedIn != expr->function()->nestedIn) {
|
|
nestedIn = nestedIn->nestedIn;
|
|
}
|
|
return nestedIn == expr->function()->nestedIn;
|
|
} else if (Token::Match(expr, "%var%") && expr->variable()) {
|
|
const Variable* var = expr->variable();
|
|
return (var->isPrivate() || var->isPublic() || var->isProtected());
|
|
}
|
|
if (Token::simpleMatch(expr, "."))
|
|
return exprDependsOnThis(expr->astOperand1(), depth);
|
|
return exprDependsOnThis(expr->astOperand1(), depth) || exprDependsOnThis(expr->astOperand2(), depth);
|
|
}
|
|
|
|
static bool hasUnknownVars(const Token* startTok)
|
|
{
|
|
bool result = false;
|
|
visitAstNodes(startTok, [&](const Token* tok) {
|
|
if (tok->varId() > 0 && !tok->variable()) {
|
|
result = true;
|
|
return ChildrenToVisit::done;
|
|
}
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
return result;
|
|
}
|
|
|
|
/// This takes a token that refers to a variable and it will return the token
|
|
/// to the expression that the variable is assigned to. If its not valid to
|
|
/// make such substitution then it will return the original token.
|
|
static const Token * followVariableExpression(const Token * tok, bool cpp, const Token * end = nullptr)
|
|
{
|
|
if (!tok)
|
|
return tok;
|
|
// Skip following variables that is across multiple files
|
|
if (end && end->fileIndex() != tok->fileIndex())
|
|
return tok;
|
|
// Skip array access
|
|
if (Token::Match(tok, "%var% ["))
|
|
return tok;
|
|
// Skip pointer indirection
|
|
if (tok->astParent() && tok->isUnaryOp("*"))
|
|
return tok;
|
|
// Skip following variables if it is used in an assignment
|
|
if (Token::Match(tok->next(), "%assign%"))
|
|
return tok;
|
|
const Variable * var = tok->variable();
|
|
const Token * varTok = getVariableInitExpression(var);
|
|
if (!varTok)
|
|
return tok;
|
|
if (hasUnknownVars(varTok))
|
|
return tok;
|
|
if (var->isVolatile())
|
|
return tok;
|
|
if (!var->isLocal() && !var->isConst())
|
|
return tok;
|
|
if (var->isStatic() && !var->isConst())
|
|
return tok;
|
|
if (var->isArgument())
|
|
return tok;
|
|
const Token * lastTok = precedes(tok, end) ? end : tok;
|
|
// If this is in a loop then check if variables are modified in the entire scope
|
|
const Token * endToken = (isInLoopCondition(tok) || isInLoopCondition(varTok) || var->scope() != tok->scope()) ? var->scope()->bodyEnd : lastTok;
|
|
if (!var->isConst() && (!precedes(varTok, endToken) || isVariableChanged(varTok, endToken, tok->varId(), false, nullptr, cpp)))
|
|
return tok;
|
|
if (precedes(varTok, endToken) && isAliased(varTok, endToken, tok->varId()))
|
|
return tok;
|
|
const Token* startToken = nextAfterAstRightmostLeaf(varTok);
|
|
if (!startToken)
|
|
startToken = varTok;
|
|
if (varTok->exprId() == 0) {
|
|
if (!varTok->isLiteral())
|
|
return tok;
|
|
} else if (!precedes(startToken, endToken)) {
|
|
return tok;
|
|
} else if (isExpressionChanged(varTok, startToken, endToken, nullptr, cpp)) {
|
|
return tok;
|
|
}
|
|
return varTok;
|
|
}
|
|
|
|
static void followVariableExpressionError(const Token *tok1, const Token *tok2, ErrorPath* errors)
|
|
{
|
|
if (!errors)
|
|
return;
|
|
if (!tok1)
|
|
return;
|
|
if (!tok2)
|
|
return;
|
|
ErrorPathItem item = std::make_pair(tok2, "'" + tok1->str() + "' is assigned value '" + tok2->expressionString() + "' here.");
|
|
if (std::find(errors->begin(), errors->end(), item) != errors->end())
|
|
return;
|
|
errors->push_back(item);
|
|
}
|
|
|
|
const Token* followReferences(const Token* tok, ErrorPath* errors, int depth = 20)
|
|
{
|
|
if (!tok)
|
|
return nullptr;
|
|
if (depth < 0)
|
|
return tok;
|
|
const Variable *var = tok->variable();
|
|
if (var && var->declarationId() == tok->varId()) {
|
|
if (var->nameToken() == tok) {
|
|
return tok;
|
|
} else if (var->isReference() || var->isRValueReference()) {
|
|
if (!var->declEndToken())
|
|
return tok;
|
|
if (var->isArgument()) {
|
|
if (errors)
|
|
errors->emplace_back(var->declEndToken(), "Passed to reference.");
|
|
return tok;
|
|
} else if (Token::simpleMatch(var->declEndToken(), "=")) {
|
|
if (errors)
|
|
errors->emplace_back(var->declEndToken(), "Assigned to reference.");
|
|
const Token *vartok = var->declEndToken()->astOperand2();
|
|
if (vartok == tok)
|
|
return tok;
|
|
if (vartok)
|
|
return followReferences(vartok, errors, depth - 1);
|
|
} else {
|
|
return tok;
|
|
}
|
|
}
|
|
} else if (Token::Match(tok->previous(), "%name% (")) {
|
|
const Function *f = tok->previous()->function();
|
|
if (f) {
|
|
if (!Function::returnsReference(f))
|
|
return tok;
|
|
std::set<const Token*> result;
|
|
ErrorPath errorPath;
|
|
for (const Token* returnTok : Function::findReturns(f)) {
|
|
if (returnTok == tok)
|
|
continue;
|
|
const Token* argvarTok = followReferences(returnTok, errors, depth - 1);
|
|
const Variable* argvar = argvarTok->variable();
|
|
if (!argvar)
|
|
return tok;
|
|
if (argvar->isArgument() && (argvar->isReference() || argvar->isRValueReference())) {
|
|
int n = getArgumentPos(argvar, f);
|
|
if (n < 0)
|
|
return tok;
|
|
std::vector<const Token*> args = getArguments(tok->previous());
|
|
if (n >= args.size())
|
|
return tok;
|
|
const Token* argTok = args[n];
|
|
ErrorPath er;
|
|
er.emplace_back(returnTok, "Return reference.");
|
|
er.emplace_back(tok->previous(), "Called function passing '" + argTok->expressionString() + "'.");
|
|
const Token* tok2 = followReferences(argTok, &er, depth - 1);
|
|
errorPath = er;
|
|
result.insert(tok2);
|
|
}
|
|
}
|
|
if (result.size() == 1) {
|
|
if (errors)
|
|
errors->insert(errors->end(), errorPath.begin(), errorPath.end());
|
|
return *result.begin();
|
|
}
|
|
}
|
|
}
|
|
return tok;
|
|
}
|
|
|
|
static bool isSameLifetime(const Token * const tok1, const Token * const tok2)
|
|
{
|
|
ValueFlow::Value v1 = getLifetimeObjValue(tok1);
|
|
ValueFlow::Value v2 = getLifetimeObjValue(tok2);
|
|
if (!v1.isLifetimeValue() || !v2.isLifetimeValue())
|
|
return false;
|
|
return v1.tokvalue == v2.tokvalue;
|
|
}
|
|
|
|
static bool compareKnownValue(const Token * const tok1, const Token * const tok2, std::function<bool(const ValueFlow::Value&, const ValueFlow::Value&, bool)> compare)
|
|
{
|
|
static const auto isKnownFn = std::mem_fn(&ValueFlow::Value::isKnown);
|
|
|
|
const auto v1 = std::find_if(tok1->values().begin(), tok1->values().end(), isKnownFn);
|
|
if (v1 == tok1->values().end()) {
|
|
return false;
|
|
}
|
|
if (v1->isNonValue() || v1->isContainerSizeValue())
|
|
return false;
|
|
const auto v2 = std::find_if(tok2->values().begin(), tok2->values().end(), isKnownFn);
|
|
if (v2 == tok2->values().end()) {
|
|
return false;
|
|
}
|
|
if (v1->valueType != v2->valueType) {
|
|
return false;
|
|
}
|
|
const bool sameLifetime = isSameLifetime(tok1, tok2);
|
|
return compare(*v1, *v2, sameLifetime);
|
|
}
|
|
|
|
bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
|
|
{
|
|
return compareKnownValue(tok1, tok2, [&](const ValueFlow::Value& v1, const ValueFlow::Value& v2, bool sameLifetime) {
|
|
bool r = v1.equalValue(v2);
|
|
if (v1.isIteratorValue()) {
|
|
r &= sameLifetime;
|
|
}
|
|
return r;
|
|
});
|
|
}
|
|
|
|
bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2)
|
|
{
|
|
return compareKnownValue(tok1, tok2, [&](const ValueFlow::Value& v1, const ValueFlow::Value& v2, bool sameLifetime) {
|
|
bool r = v1.equalValue(v2);
|
|
if (v1.isIteratorValue()) {
|
|
r &= sameLifetime;
|
|
}
|
|
return !r;
|
|
});
|
|
}
|
|
|
|
static bool isSameConstantValue(bool macro, const Token * const tok1, const Token * const tok2)
|
|
{
|
|
if (tok1 == nullptr || tok2 == nullptr)
|
|
return false;
|
|
|
|
if (!tok1->isNumber() || !tok2->isNumber())
|
|
return false;
|
|
|
|
if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro() || tok1->isTemplateArg() || tok2->isTemplateArg()))
|
|
return false;
|
|
|
|
const ValueType * v1 = tok1->valueType();
|
|
const ValueType * v2 = tok2->valueType();
|
|
|
|
if (!v1 || !v2 || v1->sign != v2->sign || v1->type != v2->type || v1->pointer != v2->pointer)
|
|
return false;
|
|
|
|
return isEqualKnownValue(tok1, tok2);
|
|
}
|
|
|
|
static bool astIsBoolLike(const Token* tok)
|
|
{
|
|
return astIsBool(tok) || astIsPointer(tok) || astIsSmartPointer(tok);
|
|
}
|
|
|
|
bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
|
|
{
|
|
if (tok1 == nullptr && tok2 == nullptr)
|
|
return true;
|
|
if (tok1 == nullptr || tok2 == nullptr)
|
|
return false;
|
|
if (cpp) {
|
|
if (tok1->str() == "." && tok1->astOperand1() && tok1->astOperand1()->str() == "this")
|
|
tok1 = tok1->astOperand2();
|
|
if (tok2->str() == "." && tok2->astOperand1() && tok2->astOperand1()->str() == "this")
|
|
tok2 = tok2->astOperand2();
|
|
}
|
|
// Skip double not
|
|
if (Token::simpleMatch(tok1, "!") && Token::simpleMatch(tok1->astOperand1(), "!") && !Token::simpleMatch(tok1->astParent(), "=")) {
|
|
return isSameExpression(cpp, macro, tok1->astOperand1()->astOperand1(), tok2, library, pure, followVar, errors);
|
|
}
|
|
if (Token::simpleMatch(tok2, "!") && Token::simpleMatch(tok2->astOperand1(), "!") && !Token::simpleMatch(tok2->astParent(), "=")) {
|
|
return isSameExpression(cpp, macro, tok1, tok2->astOperand1()->astOperand1(), library, pure, followVar, errors);
|
|
}
|
|
if (tok1->str() != tok2->str() && isDifferentKnownValues(tok1, tok2))
|
|
return false;
|
|
if (isSameConstantValue(macro, tok1, tok2))
|
|
return true;
|
|
|
|
// Follow variable
|
|
if (followVar && tok1->str() != tok2->str() && (Token::Match(tok1, "%var%") || Token::Match(tok2, "%var%"))) {
|
|
const Token * varTok1 = followVariableExpression(tok1, cpp, tok2);
|
|
if ((varTok1->str() == tok2->str()) || isSameConstantValue(macro, varTok1, tok2)) {
|
|
followVariableExpressionError(tok1, varTok1, errors);
|
|
return isSameExpression(cpp, macro, varTok1, tok2, library, true, followVar, errors);
|
|
}
|
|
const Token * varTok2 = followVariableExpression(tok2, cpp, tok1);
|
|
if ((tok1->str() == varTok2->str()) || isSameConstantValue(macro, tok1, varTok2)) {
|
|
followVariableExpressionError(tok2, varTok2, errors);
|
|
return isSameExpression(cpp, macro, tok1, varTok2, library, true, followVar, errors);
|
|
}
|
|
if ((varTok1->str() == varTok2->str()) || isSameConstantValue(macro, varTok1, varTok2)) {
|
|
followVariableExpressionError(tok1, varTok1, errors);
|
|
followVariableExpressionError(tok2, varTok2, errors);
|
|
return isSameExpression(cpp, macro, varTok1, varTok2, library, true, followVar, errors);
|
|
}
|
|
}
|
|
// Follow references
|
|
if (tok1->str() != tok2->str()) {
|
|
const Token* refTok1 = followReferences(tok1, errors);
|
|
const Token* refTok2 = followReferences(tok2, errors);
|
|
if (refTok1 != tok1 || refTok2 != tok2)
|
|
return isSameExpression(cpp, macro, refTok1, refTok2, library, pure, followVar, errors);
|
|
}
|
|
if (tok1->varId() != tok2->varId() || tok1->str() != tok2->str() || tok1->originalName() != tok2->originalName()) {
|
|
if ((Token::Match(tok1,"<|>") && Token::Match(tok2,"<|>")) ||
|
|
(Token::Match(tok1,"<=|>=") && Token::Match(tok2,"<=|>="))) {
|
|
return isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors) &&
|
|
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
|
|
}
|
|
const Token* condTok = nullptr;
|
|
const Token* exprTok = nullptr;
|
|
if (Token::Match(tok1, "==|!=")) {
|
|
condTok = tok1;
|
|
exprTok = tok2;
|
|
} else if (Token::Match(tok2, "==|!=")) {
|
|
condTok = tok2;
|
|
exprTok = tok1;
|
|
}
|
|
if (condTok && condTok->astOperand1() && condTok->astOperand2() && !Token::Match(exprTok, "%comp%")) {
|
|
const Token* varTok1 = nullptr;
|
|
const Token* varTok2 = exprTok;
|
|
const ValueFlow::Value* value = nullptr;
|
|
if (condTok->astOperand1()->hasKnownIntValue()) {
|
|
value = &condTok->astOperand1()->values().front();
|
|
varTok1 = condTok->astOperand2();
|
|
} else if (condTok->astOperand2()->hasKnownIntValue()) {
|
|
value = &condTok->astOperand2()->values().front();
|
|
varTok1 = condTok->astOperand1();
|
|
}
|
|
if (Token::simpleMatch(exprTok, "!"))
|
|
varTok2 = exprTok->astOperand1();
|
|
bool compare = false;
|
|
if (value) {
|
|
if (value->intvalue == 0 && Token::simpleMatch(exprTok, "!") && Token::simpleMatch(condTok, "==")) {
|
|
compare = true;
|
|
} else if (value->intvalue == 0 && !Token::simpleMatch(exprTok, "!") && Token::simpleMatch(condTok, "!=")) {
|
|
compare = true;
|
|
} else if (value->intvalue != 0 && Token::simpleMatch(exprTok, "!") && Token::simpleMatch(condTok, "!=")) {
|
|
compare = true;
|
|
} else if (value->intvalue != 0 && !Token::simpleMatch(exprTok, "!") && Token::simpleMatch(condTok, "==")) {
|
|
compare = true;
|
|
}
|
|
|
|
}
|
|
if (compare && astIsBoolLike(varTok1) && astIsBoolLike(varTok2))
|
|
return isSameExpression(cpp, macro, varTok1, varTok2, library, pure, followVar, errors);
|
|
|
|
}
|
|
return false;
|
|
}
|
|
if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro() || tok1->isTemplateArg() || tok2->isTemplateArg()))
|
|
return false;
|
|
if (tok1->isComplex() != tok2->isComplex())
|
|
return false;
|
|
if (tok1->isLong() != tok2->isLong())
|
|
return false;
|
|
if (tok1->isUnsigned() != tok2->isUnsigned())
|
|
return false;
|
|
if (tok1->isSigned() != tok2->isSigned())
|
|
return false;
|
|
if (pure && tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof" && !(tok1->variable() && tok1 == tok1->variable()->nameToken())) {
|
|
if (!tok1->function()) {
|
|
if (Token::simpleMatch(tok1->previous(), ".")) {
|
|
const Token *lhs = tok1->previous();
|
|
while (Token::Match(lhs, "(|.|["))
|
|
lhs = lhs->astOperand1();
|
|
if (!lhs)
|
|
return false;
|
|
const bool lhsIsConst = (lhs->variable() && lhs->variable()->isConst()) ||
|
|
(lhs->valueType() && lhs->valueType()->constness > 0) ||
|
|
(Token::Match(lhs, "%var% . %name% (") && library.isFunctionConst(lhs->tokAt(2)));
|
|
if (!lhsIsConst)
|
|
return false;
|
|
} else {
|
|
const Token * ftok = tok1;
|
|
if (Token::simpleMatch(tok1->previous(), "::"))
|
|
ftok = tok1->previous();
|
|
if (!library.isFunctionConst(ftok) && !ftok->isAttributeConst() && !ftok->isAttributePure())
|
|
return false;
|
|
}
|
|
} else {
|
|
if (tok1->function() && !tok1->function()->isConst() && !tok1->function()->isAttributeConst() && !tok1->function()->isAttributePure())
|
|
return false;
|
|
}
|
|
}
|
|
// templates/casts
|
|
if ((Token::Match(tok1, "%name% <") && tok1->next()->link()) ||
|
|
(Token::Match(tok2, "%name% <") && tok2->next()->link())) {
|
|
|
|
// non-const template function that is not a dynamic_cast => return false
|
|
if (pure && Token::simpleMatch(tok1->next()->link(), "> (") &&
|
|
!(tok1->function() && tok1->function()->isConst()) &&
|
|
tok1->str() != "dynamic_cast")
|
|
return false;
|
|
|
|
// some template/cast stuff.. check that the template arguments are same
|
|
const Token *t1 = tok1->next();
|
|
const Token *t2 = tok2->next();
|
|
const Token *end1 = t1->link();
|
|
const Token *end2 = t2->link();
|
|
while (t1 && t2 && t1 != end1 && t2 != end2) {
|
|
if (t1->str() != t2->str())
|
|
return false;
|
|
t1 = t1->next();
|
|
t2 = t2->next();
|
|
}
|
|
if (t1 != end1 || t2 != end2)
|
|
return false;
|
|
}
|
|
if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
|
|
return false;
|
|
// bailout when we see ({..})
|
|
if (tok1->str() == "{")
|
|
return false;
|
|
// cast => assert that the casts are equal
|
|
if (tok1->str() == "(" && tok1->previous() &&
|
|
!tok1->previous()->isName() &&
|
|
!(tok1->previous()->str() == ">" && tok1->previous()->link())) {
|
|
const Token *t1 = tok1->next();
|
|
const Token *t2 = tok2->next();
|
|
while (t1 && t2 &&
|
|
t1->str() == t2->str() &&
|
|
t1->isLong() == t2->isLong() &&
|
|
t1->isUnsigned() == t2->isUnsigned() &&
|
|
t1->isSigned() == t2->isSigned() &&
|
|
(t1->isName() || t1->str() == "*")) {
|
|
t1 = t1->next();
|
|
t2 = t2->next();
|
|
}
|
|
if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
|
|
return false;
|
|
}
|
|
bool noncommutativeEquals =
|
|
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand1(), library, pure, followVar, errors);
|
|
noncommutativeEquals = noncommutativeEquals &&
|
|
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand2(), library, pure, followVar, errors);
|
|
|
|
if (noncommutativeEquals)
|
|
return true;
|
|
|
|
// in c++, a+b might be different to b+a, depending on the type of a and b
|
|
if (cpp && tok1->str() == "+" && tok1->isBinaryOp()) {
|
|
const ValueType* vt1 = tok1->astOperand1()->valueType();
|
|
const ValueType* vt2 = tok1->astOperand2()->valueType();
|
|
if (!(vt1 && (vt1->type >= ValueType::VOID || vt1->pointer) && vt2 && (vt2->type >= ValueType::VOID || vt2->pointer)))
|
|
return false;
|
|
}
|
|
|
|
const bool commutative = tok1->isBinaryOp() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
|
|
bool commutativeEquals = commutative &&
|
|
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
|
|
commutativeEquals = commutativeEquals &&
|
|
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors);
|
|
|
|
|
|
return commutativeEquals;
|
|
}
|
|
|
|
static bool isZeroBoundCond(const Token * const cond)
|
|
{
|
|
if (cond == nullptr)
|
|
return false;
|
|
// Assume unsigned
|
|
// TODO: Handle reverse conditions
|
|
const bool isZero = cond->astOperand2()->getValue(0);
|
|
if (cond->str() == "==" || cond->str() == ">=")
|
|
return isZero;
|
|
if (cond->str() == "<=")
|
|
return true;
|
|
if (cond->str() == "<")
|
|
return !isZero;
|
|
if (cond->str() == ">")
|
|
return false;
|
|
return false;
|
|
}
|
|
|
|
bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
|
|
{
|
|
if (!cond1 || !cond2)
|
|
return false;
|
|
|
|
if (!isNot && cond1->str() == "&&" && cond2->str() == "&&") {
|
|
for (const Token* tok1: {
|
|
cond1->astOperand1(), cond1->astOperand2()
|
|
}) {
|
|
for (const Token* tok2: {
|
|
cond2->astOperand1(), cond2->astOperand2()
|
|
}) {
|
|
if (isSameExpression(cpp, true, tok1, tok2, library, pure, followVar, errors)) {
|
|
if (isOppositeCond(isNot, cpp, tok1->astSibling(), tok2->astSibling(), library, pure, followVar, errors))
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (cond1->str() == "!") {
|
|
if (cond2->str() == "!=") {
|
|
if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
|
|
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors);
|
|
if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
|
|
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors);
|
|
}
|
|
return isSameExpression(cpp, true, cond1->astOperand1(), cond2, library, pure, followVar, errors);
|
|
}
|
|
|
|
if (cond2->str() == "!")
|
|
return isOppositeCond(isNot, cpp, cond2, cond1, library, pure, followVar, errors);
|
|
|
|
if (!isNot) {
|
|
if (cond1->str() == "==" && cond2->str() == "==") {
|
|
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors))
|
|
return isDifferentKnownValues(cond1->astOperand2(), cond2->astOperand2());
|
|
if (isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors))
|
|
return isDifferentKnownValues(cond1->astOperand1(), cond2->astOperand1());
|
|
}
|
|
// TODO: Handle reverse conditions
|
|
if (Library::isContainerYield(cond1, Library::Container::Yield::EMPTY, "empty") &&
|
|
Library::isContainerYield(cond2->astOperand1(), Library::Container::Yield::SIZE, "size") &&
|
|
cond1->astOperand1()->astOperand1()->varId() == cond2->astOperand1()->astOperand1()->astOperand1()->varId()) {
|
|
return !isZeroBoundCond(cond2);
|
|
}
|
|
|
|
if (Library::isContainerYield(cond2, Library::Container::Yield::EMPTY, "empty") &&
|
|
Library::isContainerYield(cond1->astOperand1(), Library::Container::Yield::SIZE, "size") &&
|
|
cond2->astOperand1()->astOperand1()->varId() == cond1->astOperand1()->astOperand1()->astOperand1()->varId()) {
|
|
return !isZeroBoundCond(cond1);
|
|
}
|
|
}
|
|
|
|
|
|
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
|
|
return false;
|
|
|
|
const std::string &comp1 = cond1->str();
|
|
|
|
// condition found .. get comparator
|
|
std::string comp2;
|
|
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors) &&
|
|
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors)) {
|
|
comp2 = cond2->str();
|
|
} else if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors) &&
|
|
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand1(), library, pure, followVar, errors)) {
|
|
comp2 = cond2->str();
|
|
if (comp2[0] == '>')
|
|
comp2[0] = '<';
|
|
else if (comp2[0] == '<')
|
|
comp2[0] = '>';
|
|
}
|
|
|
|
if (!isNot && comp2.empty()) {
|
|
const Token *expr1 = nullptr, *value1 = nullptr, *expr2 = nullptr, *value2 = nullptr;
|
|
std::string op1 = cond1->str(), op2 = cond2->str();
|
|
if (cond1->astOperand2()->hasKnownIntValue()) {
|
|
expr1 = cond1->astOperand1();
|
|
value1 = cond1->astOperand2();
|
|
} else if (cond1->astOperand1()->hasKnownIntValue()) {
|
|
expr1 = cond1->astOperand2();
|
|
value1 = cond1->astOperand1();
|
|
if (op1[0] == '>')
|
|
op1[0] = '<';
|
|
else if (op1[0] == '<')
|
|
op1[0] = '>';
|
|
}
|
|
if (cond2->astOperand2()->hasKnownIntValue()) {
|
|
expr2 = cond2->astOperand1();
|
|
value2 = cond2->astOperand2();
|
|
} else if (cond2->astOperand1()->hasKnownIntValue()) {
|
|
expr2 = cond2->astOperand2();
|
|
value2 = cond2->astOperand1();
|
|
if (op2[0] == '>')
|
|
op2[0] = '<';
|
|
else if (op2[0] == '<')
|
|
op2[0] = '>';
|
|
}
|
|
if (!expr1 || !value1 || !expr2 || !value2) {
|
|
return false;
|
|
}
|
|
if (!isSameExpression(cpp, true, expr1, expr2, library, pure, followVar, errors))
|
|
return false;
|
|
|
|
const ValueFlow::Value &rhsValue1 = value1->values().front();
|
|
const ValueFlow::Value &rhsValue2 = value2->values().front();
|
|
|
|
if (op1 == "<" || op1 == "<=")
|
|
return (op2 == "==" || op2 == ">" || op2 == ">=") && (rhsValue1.intvalue < rhsValue2.intvalue);
|
|
else if (op1 == ">=" || op1 == ">")
|
|
return (op2 == "==" || op2 == "<" || op2 == "<=") && (rhsValue1.intvalue > rhsValue2.intvalue);
|
|
|
|
return false;
|
|
}
|
|
|
|
// is condition opposite?
|
|
return ((comp1 == "==" && comp2 == "!=") ||
|
|
(comp1 == "!=" && comp2 == "==") ||
|
|
(comp1 == "<" && comp2 == ">=") ||
|
|
(comp1 == "<=" && comp2 == ">") ||
|
|
(comp1 == ">" && comp2 == "<=") ||
|
|
(comp1 == ">=" && comp2 == "<") ||
|
|
(!isNot && ((comp1 == "<" && comp2 == ">") ||
|
|
(comp1 == ">" && comp2 == "<") ||
|
|
(comp1 == "==" && (comp2 == "!=" || comp2 == ">" || comp2 == "<")) ||
|
|
((comp1 == "!=" || comp1 == ">" || comp1 == "<") && comp2 == "==")
|
|
)));
|
|
}
|
|
|
|
bool isOppositeExpression(bool cpp, const Token * const tok1, const Token * const tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
|
|
{
|
|
if (!tok1 || !tok2)
|
|
return false;
|
|
if (isOppositeCond(true, cpp, tok1, tok2, library, pure, followVar, errors))
|
|
return true;
|
|
if (tok1->isUnaryOp("-"))
|
|
return isSameExpression(cpp, true, tok1->astOperand1(), tok2, library, pure, followVar, errors);
|
|
if (tok2->isUnaryOp("-"))
|
|
return isSameExpression(cpp, true, tok2->astOperand1(), tok1, library, pure, followVar, errors);
|
|
return false;
|
|
}
|
|
|
|
bool isConstExpression(const Token *tok, const Library& library, bool pure, bool cpp)
|
|
{
|
|
if (!tok)
|
|
return true;
|
|
if (tok->isName() && tok->next()->str() == "(") {
|
|
if (!tok->function() && !Token::Match(tok->previous(), ".|::") && !library.isFunctionConst(tok->str(), pure))
|
|
return false;
|
|
else if (tok->function() && !tok->function()->isConst())
|
|
return false;
|
|
}
|
|
if (tok->tokType() == Token::eIncDecOp)
|
|
return false;
|
|
if (tok->isAssignmentOp())
|
|
return false;
|
|
if (isLikelyStreamRead(cpp, tok))
|
|
return false;
|
|
// bailout when we see ({..})
|
|
if (tok->str() == "{")
|
|
return false;
|
|
return isConstExpression(tok->astOperand1(), library, pure, cpp) && isConstExpression(tok->astOperand2(), library, pure, cpp);
|
|
}
|
|
|
|
bool isWithoutSideEffects(bool cpp, const Token* tok)
|
|
{
|
|
if (!cpp)
|
|
return true;
|
|
|
|
while (tok && tok->astOperand2() && tok->astOperand2()->str() != "(")
|
|
tok = tok->astOperand2();
|
|
if (tok && tok->varId()) {
|
|
const Variable* var = tok->variable();
|
|
return var && (!var->isClass() || var->isPointer() || var->isStlType());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool isUniqueExpression(const Token* tok)
|
|
{
|
|
if (!tok)
|
|
return true;
|
|
if (tok->function()) {
|
|
const Function * fun = tok->function();
|
|
const Scope * scope = fun->nestedIn;
|
|
if (!scope)
|
|
return true;
|
|
const std::string returnType = fun->retType ? fun->retType->name() : fun->retDef->stringifyList(fun->tokenDef);
|
|
for (const Function& f:scope->functionList) {
|
|
if (f.type != Function::eFunction)
|
|
continue;
|
|
|
|
const std::string freturnType = f.retType ? f.retType->name() : f.retDef->stringifyList(f.tokenDef);
|
|
if (f.argumentList.size() == fun->argumentList.size() &&
|
|
returnType == freturnType &&
|
|
f.name() != fun->name()) {
|
|
return false;
|
|
}
|
|
}
|
|
} else if (tok->variable()) {
|
|
const Variable * var = tok->variable();
|
|
const Scope * scope = var->scope();
|
|
if (!scope)
|
|
return true;
|
|
const Type * varType = var->type();
|
|
// Iterate over the variables in scope and the parameters of the function if possible
|
|
const Function * fun = scope->function;
|
|
const std::list<Variable>* setOfVars[] = {&scope->varlist, fun ? &fun->argumentList : nullptr};
|
|
|
|
for (const std::list<Variable>* vars:setOfVars) {
|
|
if (!vars)
|
|
continue;
|
|
bool other = std::any_of(vars->cbegin(), vars->cend(), [=](const Variable &v) {
|
|
if (varType)
|
|
return v.type() && v.type()->name() == varType->name() && v.name() != var->name();
|
|
return v.isFloatingType() == var->isFloatingType() &&
|
|
v.isEnumType() == var->isEnumType() &&
|
|
v.isClass() == var->isClass() &&
|
|
v.isArray() == var->isArray() &&
|
|
v.isPointer() == var->isPointer() &&
|
|
v.name() != var->name();
|
|
});
|
|
if (other)
|
|
return false;
|
|
}
|
|
} else if (!isUniqueExpression(tok->astOperand1())) {
|
|
return false;
|
|
}
|
|
|
|
return isUniqueExpression(tok->astOperand2());
|
|
}
|
|
|
|
static bool isEscaped(const Token* tok, bool functionsScope, const Library* library)
|
|
{
|
|
if (library && library->isnoreturn(tok))
|
|
return true;
|
|
if (functionsScope)
|
|
return Token::simpleMatch(tok, "throw");
|
|
else
|
|
return Token::Match(tok, "return|throw");
|
|
}
|
|
|
|
static bool isEscapedOrJump(const Token* tok, bool functionsScope, const Library* library)
|
|
{
|
|
if (library && library->isnoreturn(tok))
|
|
return true;
|
|
if (functionsScope)
|
|
return Token::simpleMatch(tok, "throw");
|
|
else
|
|
return Token::Match(tok, "return|goto|throw|continue|break");
|
|
}
|
|
|
|
bool isEscapeFunction(const Token* ftok, const Library* library)
|
|
{
|
|
if (!Token::Match(ftok, "%name% ("))
|
|
return false;
|
|
const Function* function = ftok->function();
|
|
if (function) {
|
|
if (function->isEscapeFunction())
|
|
return true;
|
|
if (function->isAttributeNoreturn())
|
|
return true;
|
|
} else if (library) {
|
|
if (library->isnoreturn(ftok))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool hasNoreturnFunction(const Token* tok, const Library* library, const Token** unknownFunc)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
const Token* ftok = tok->str() == "(" ? tok->previous() : nullptr;
|
|
while (Token::simpleMatch(ftok, "("))
|
|
ftok = ftok->astOperand1();
|
|
if (ftok) {
|
|
const Function * function = ftok->function();
|
|
if (function) {
|
|
if (function->isEscapeFunction())
|
|
return true;
|
|
if (function->isAttributeNoreturn())
|
|
return true;
|
|
} else if (library && library->isnoreturn(ftok)) {
|
|
return true;
|
|
} else if (Token::Match(ftok, "exit|abort")) {
|
|
return true;
|
|
}
|
|
if (unknownFunc && !function && library && library->functions.count(library->getFunctionName(ftok)) == 0)
|
|
*unknownFunc = ftok;
|
|
return false;
|
|
} else if (tok->isConstOp()) {
|
|
return hasNoreturnFunction(tok->astOperand1(), library, unknownFunc) || hasNoreturnFunction(tok->astOperand2(), library, unknownFunc);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool isReturnScope(const Token* const endToken, const Library* library, const Token** unknownFunc, bool functionScope)
|
|
{
|
|
if (!endToken || endToken->str() != "}")
|
|
return false;
|
|
|
|
const Token *prev = endToken->previous();
|
|
while (prev && Token::simpleMatch(prev->previous(), "; ;"))
|
|
prev = prev->previous();
|
|
if (prev && Token::simpleMatch(prev->previous(), "} ;"))
|
|
prev = prev->previous();
|
|
|
|
if (Token::simpleMatch(prev, "}")) {
|
|
if (Token::simpleMatch(prev->link()->tokAt(-2), "} else {"))
|
|
return isReturnScope(prev, library, unknownFunc, functionScope) &&
|
|
isReturnScope(prev->link()->tokAt(-2), library, unknownFunc, functionScope);
|
|
if (Token::simpleMatch(prev->link()->previous(), ") {") &&
|
|
Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "switch (") &&
|
|
!Token::findsimplematch(prev->link(), "break", prev)) {
|
|
return true;
|
|
}
|
|
if (isEscaped(prev->link()->astTop(), functionScope, library))
|
|
return true;
|
|
if (Token::Match(prev->link()->previous(), "[;{}] {"))
|
|
return isReturnScope(prev, library, unknownFunc, functionScope);
|
|
} else if (Token::simpleMatch(prev, ";")) {
|
|
if (prev->tokAt(-2) && hasNoreturnFunction(prev->tokAt(-2)->astTop(), library, unknownFunc))
|
|
return true;
|
|
// Unknown symbol
|
|
if (Token::Match(prev->tokAt(-2), ";|}|{ %name% ;") && prev->previous()->isIncompleteVar()) {
|
|
if (unknownFunc)
|
|
*unknownFunc = prev->previous();
|
|
return false;
|
|
}
|
|
if (Token::simpleMatch(prev->previous(), ") ;") && prev->previous()->link() &&
|
|
isEscaped(prev->previous()->link()->astTop(), functionScope, library))
|
|
return true;
|
|
if (isEscaped(prev->previous()->astTop(), functionScope, library))
|
|
return true;
|
|
// return/goto statement
|
|
prev = prev->previous();
|
|
while (prev && !Token::Match(prev, ";|{|}") && !isEscapedOrJump(prev, functionScope, library))
|
|
prev = prev->previous();
|
|
return prev && prev->isName();
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isVariableChangedByFunctionCall(const Token *tok, int indirect, nonneg int varid, const Settings *settings, bool *inconclusive)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (tok->varId() == varid)
|
|
return isVariableChangedByFunctionCall(tok, indirect, settings, inconclusive);
|
|
return isVariableChangedByFunctionCall(tok->astOperand1(), indirect, varid, settings, inconclusive) ||
|
|
isVariableChangedByFunctionCall(tok->astOperand2(), indirect, varid, settings, inconclusive);
|
|
}
|
|
|
|
bool isScopeBracket(const Token* tok)
|
|
{
|
|
if (!Token::Match(tok, "{|}"))
|
|
return false;
|
|
if (!tok->scope())
|
|
return false;
|
|
if (tok->str() == "{")
|
|
return tok->scope()->bodyStart == tok;
|
|
if (tok->str() == "}")
|
|
return tok->scope()->bodyEnd == tok;
|
|
return false;
|
|
}
|
|
|
|
const Token * getTokenArgumentFunction(const Token * tok, int& argn)
|
|
{
|
|
argn = -1;
|
|
{
|
|
const Token *parent = tok->astParent();
|
|
if (parent && parent->isUnaryOp("&"))
|
|
parent = parent->astParent();
|
|
while (parent && parent->isCast())
|
|
parent = parent->astParent();
|
|
if (Token::Match(parent, "[+-]") && parent->valueType() && parent->valueType()->pointer)
|
|
parent = parent->astParent();
|
|
|
|
// passing variable to subfunction?
|
|
if (Token::Match(parent, "[(,{]"))
|
|
;
|
|
else if (Token::simpleMatch(parent, ":")) {
|
|
while (Token::Match(parent, "[?:]"))
|
|
parent = parent->astParent();
|
|
while (Token::simpleMatch(parent, ","))
|
|
parent = parent->astParent();
|
|
if (!parent || parent->str() != "(")
|
|
return nullptr;
|
|
} else
|
|
return nullptr;
|
|
}
|
|
|
|
const Token* argtok = tok;
|
|
while (argtok && argtok->astParent() && (!Token::Match(argtok->astParent(), ",|(|{") || argtok->astParent()->isCast())) {
|
|
argtok = argtok->astParent();
|
|
}
|
|
if (!argtok)
|
|
return nullptr;
|
|
if (Token::simpleMatch(argtok, ","))
|
|
argtok = argtok->astOperand1();
|
|
if (Token::simpleMatch(argtok, "(") && argtok->astOperand2())
|
|
argtok = argtok->astOperand2();
|
|
tok = argtok;
|
|
while (Token::Match(tok->astParent(), ",|(|{")) {
|
|
tok = tok->astParent();
|
|
if (Token::Match(tok, "(|{"))
|
|
break;
|
|
}
|
|
std::vector<const Token*> args = getArguments(tok);
|
|
auto it = std::find(args.begin(), args.end(), argtok);
|
|
if (it != args.end())
|
|
argn = std::distance(args.begin(), it);
|
|
if (argn == -1)
|
|
return nullptr;
|
|
if (!Token::Match(tok, "{|("))
|
|
return nullptr;
|
|
tok = tok->astOperand1();
|
|
while (Token::simpleMatch(tok, "."))
|
|
tok = tok->astOperand2();
|
|
while (Token::simpleMatch(tok, "::")) {
|
|
// If there is only a op1 and not op2, then this is a global scope
|
|
if (!tok->astOperand2() && tok->astOperand1()) {
|
|
tok = tok->astOperand1();
|
|
break;
|
|
}
|
|
tok = tok->astOperand2();
|
|
if (Token::simpleMatch(tok, "<") && tok->link())
|
|
tok = tok->astOperand1();
|
|
}
|
|
if (tok && tok->link() && tok->str() == ">")
|
|
tok = tok->link()->previous();
|
|
if (!Token::Match(tok, "%name%|(|{"))
|
|
return nullptr;
|
|
return tok;
|
|
}
|
|
|
|
static std::vector<const Variable*> getArgumentVars(const Token* tok, int argnr)
|
|
{
|
|
std::vector<const Variable*> result;
|
|
if (!tok)
|
|
return result;
|
|
if (tok->function())
|
|
return {tok->function()->getArgumentVar(argnr)};
|
|
if (Token::Match(tok->previous(), "%type% (|{") || tok->variable()) {
|
|
const bool constructor = tok->variable() && tok->variable()->nameToken() == tok;
|
|
const Type* type = Token::typeOf(tok);
|
|
if (!type)
|
|
return result;
|
|
const Scope* typeScope = type->classScope;
|
|
if (!typeScope)
|
|
return result;
|
|
const int argCount = numberOfArguments(tok);
|
|
for (const Function &function : typeScope->functionList) {
|
|
if (function.argCount() < argCount)
|
|
continue;
|
|
if (constructor && !function.isConstructor())
|
|
continue;
|
|
if (!constructor && !Token::simpleMatch(function.token, "operator()"))
|
|
continue;
|
|
result.push_back(function.getArgumentVar(argnr));
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
static bool isCPPCastKeyword(const Token* tok)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
return endsWith(tok->str(), "_cast", 5);
|
|
}
|
|
|
|
bool isVariableChangedByFunctionCall(const Token *tok, int indirect, const Settings *settings, bool *inconclusive)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
|
|
if (Token::simpleMatch(tok, ","))
|
|
return false;
|
|
|
|
const Token * const tok1 = tok;
|
|
|
|
// address of variable
|
|
const bool addressOf = tok->astParent() && tok->astParent()->isUnaryOp("&");
|
|
|
|
int argnr;
|
|
tok = getTokenArgumentFunction(tok, argnr);
|
|
if (!tok)
|
|
return false; // not a function => variable not changed
|
|
if (tok->isKeyword() && !isCPPCastKeyword(tok))
|
|
return false;
|
|
const Token * parenTok = tok->next();
|
|
if (Token::simpleMatch(parenTok, "<") && parenTok->link())
|
|
parenTok = parenTok->link()->next();
|
|
const bool possiblyPassedByReference = (parenTok->next() == tok1 || Token::Match(tok1->previous(), ", %name% [,)}]"));
|
|
|
|
if (!tok->function() && !tok->variable() && Token::Match(tok, "%name%")) {
|
|
// Check if direction (in, out, inout) is specified in the library configuration and use that
|
|
if (!addressOf && settings) {
|
|
const Library::ArgumentChecks::Direction argDirection = settings->library.getArgDirection(tok, 1 + argnr);
|
|
if (argDirection == Library::ArgumentChecks::Direction::DIR_IN)
|
|
return false;
|
|
else if (argDirection == Library::ArgumentChecks::Direction::DIR_OUT ||
|
|
argDirection == Library::ArgumentChecks::Direction::DIR_INOUT) {
|
|
// With out or inout the direction of the content is specified, not a pointer itself, so ignore pointers for now
|
|
const ValueType * const valueType = tok1->valueType();
|
|
if (valueType && valueType->pointer == indirect) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
// if the library says 0 is invalid
|
|
// => it is assumed that parameter is an in parameter (TODO: this is a bad heuristic)
|
|
if (!addressOf && settings && settings->library.isnullargbad(tok, 1+argnr))
|
|
return false;
|
|
// possible pass-by-reference => inconclusive
|
|
if (possiblyPassedByReference) {
|
|
if (inconclusive != nullptr)
|
|
*inconclusive = true;
|
|
return false;
|
|
}
|
|
// Safe guess: Assume that parameter is changed by function call
|
|
return true;
|
|
}
|
|
|
|
std::vector<const Variable*> args = getArgumentVars(tok, argnr);
|
|
bool conclusive = false;
|
|
for (const Variable *arg:args) {
|
|
if (!arg)
|
|
continue;
|
|
conclusive = true;
|
|
if (addressOf || (indirect > 0 && arg->isPointer())) {
|
|
if (!arg->isConst())
|
|
return true;
|
|
// If const is applied to the pointer, then the value can still be modified
|
|
if (Token::simpleMatch(arg->typeEndToken(), "* const"))
|
|
return true;
|
|
}
|
|
if (!arg->isConst() && arg->isReference())
|
|
return true;
|
|
}
|
|
if (!conclusive && inconclusive) {
|
|
*inconclusive = true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isVariableChanged(const Token *tok, int indirect, const Settings *settings, bool cpp, int depth)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
const Token *tok2 = tok;
|
|
int derefs = 0;
|
|
while (Token::simpleMatch(tok2->astParent(), "*") ||
|
|
(Token::simpleMatch(tok2->astParent(), ".") && !Token::simpleMatch(tok2->astParent()->astParent(), "(")) ||
|
|
(Token::simpleMatch(tok2->astParent(), "[") && tok2 == tok2->astParent()->astOperand1())) {
|
|
if (Token::simpleMatch(tok2->astParent(), "*") || tok2->astParent()->originalName() == "->")
|
|
derefs++;
|
|
if (derefs > indirect)
|
|
break;
|
|
tok2 = tok2->astParent();
|
|
}
|
|
|
|
while (Token::simpleMatch(tok2->astParent(), "?") || (Token::simpleMatch(tok2->astParent(), ":") && Token::simpleMatch(tok2->astParent()->astParent(), "?")))
|
|
tok2 = tok2->astParent();
|
|
|
|
if (Token::Match(tok2->astParent(), "++|--"))
|
|
return true;
|
|
|
|
if (tok2->astParent() && tok2->astParent()->isAssignmentOp()) {
|
|
if (tok2 == tok2->astParent()->astOperand1())
|
|
return true;
|
|
// Check if assigning to a non-const lvalue
|
|
const Variable * var = getLHSVariable(tok2->astParent());
|
|
if (var && var->isReference() && !var->isConst() && var->nameToken() && var->nameToken()->next() == tok2->astParent()) {
|
|
if (!var->isLocal() || isVariableChanged(var, settings, cpp, depth - 1))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
if (cpp && Token::simpleMatch(tok2->astParent(), ">>") && tok2->astParent()->astOperand2() == tok2 && isLikelyStreamRead(cpp, tok2->astParent()))
|
|
return true;
|
|
|
|
if (isLikelyStream(cpp, tok2))
|
|
return true;
|
|
|
|
// Member function call
|
|
if (tok->variable() && Token::Match(tok2->astParent(), ". %name%") && isFunctionCall(tok2->astParent()->next()) && tok2->astParent()->astOperand1() == tok2) {
|
|
const Variable * var = tok->variable();
|
|
bool isConst = var && var->isConst();
|
|
if (!isConst) {
|
|
const ValueType * valueType = var->valueType();
|
|
isConst = (valueType && valueType->pointer == 1 && valueType->constness == 1);
|
|
}
|
|
|
|
const Token *ftok = tok->tokAt(2);
|
|
const Function * fun = ftok->function();
|
|
if (!isConst && (!fun || !fun->isConst()))
|
|
return true;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
const Token *ftok = tok2;
|
|
while (ftok && (!Token::Match(ftok, "[({]") || ftok->isCast()))
|
|
ftok = ftok->astParent();
|
|
|
|
if (ftok && Token::Match(ftok->link(), ")|} !!{")) {
|
|
const Token * ptok = tok2;
|
|
while (Token::Match(ptok->astParent(), ".|::|["))
|
|
ptok = ptok->astParent();
|
|
bool inconclusive = false;
|
|
bool isChanged = isVariableChangedByFunctionCall(ptok, indirect, settings, &inconclusive);
|
|
isChanged |= inconclusive;
|
|
if (isChanged)
|
|
return true;
|
|
}
|
|
|
|
const Token *parent = tok2->astParent();
|
|
while (Token::Match(parent, ".|::"))
|
|
parent = parent->astParent();
|
|
if (parent && parent->tokType() == Token::eIncDecOp)
|
|
return true;
|
|
|
|
if (Token::simpleMatch(tok2->astParent(), ":") && tok2->astParent()->astParent() && Token::simpleMatch(tok2->astParent()->astParent()->previous(), "for (")) {
|
|
const Token * varTok = tok2->astParent()->previous();
|
|
if (!varTok)
|
|
return false;
|
|
const Variable * loopVar = varTok->variable();
|
|
if (!loopVar)
|
|
return false;
|
|
if (!loopVar->isConst() && loopVar->isReference() && isVariableChanged(loopVar, settings, cpp, depth - 1))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
if (indirect > 0) {
|
|
// check for `*(ptr + 1) = new_value` case
|
|
parent = tok2->astParent();
|
|
while (parent && parent->isArithmeticalOp() && parent->isBinaryOp()) {
|
|
parent = parent->astParent();
|
|
}
|
|
if (Token::simpleMatch(parent, "*")) {
|
|
if (parent->astParent() && parent->astParent()->isAssignmentOp() &&
|
|
(parent->astParent()->astOperand1() == parent)) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool isVariableChanged(const Token *start, const Token *end, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
|
|
{
|
|
return findVariableChanged(start, end, 0, exprid, globalvar, settings, cpp, depth) != nullptr;
|
|
}
|
|
|
|
bool isVariableChanged(const Token *start, const Token *end, int indirect, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
|
|
{
|
|
return findVariableChanged(start, end, indirect, exprid, globalvar, settings, cpp, depth) != nullptr;
|
|
}
|
|
|
|
static const Token* findExpression(const Token* start, const nonneg int exprid)
|
|
{
|
|
Function * f = Scope::nestedInFunction(start->scope());
|
|
if (!f)
|
|
return nullptr;
|
|
const Scope* scope = f->functionScope;
|
|
if (!scope)
|
|
return nullptr;
|
|
for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (tok->exprId() != exprid)
|
|
continue;
|
|
return tok;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
// Thread-unsafe memoization
|
|
template<class F, class R=decltype(std::declval<F>()())>
|
|
static std::function<R()> memoize(F f)
|
|
{
|
|
bool init = false;
|
|
R result{};
|
|
return [=]() mutable -> R {
|
|
if (init)
|
|
return result;
|
|
result = f();
|
|
init = true;
|
|
return result;
|
|
};
|
|
}
|
|
|
|
Token* findVariableChanged(Token *start, const Token *end, int indirect, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
|
|
{
|
|
if (!precedes(start, end))
|
|
return nullptr;
|
|
if (depth < 0)
|
|
return start;
|
|
auto getExprTok = memoize([&] { return findExpression(start, exprid); });
|
|
for (Token *tok = start; tok != end; tok = tok->next()) {
|
|
if (tok->exprId() != exprid) {
|
|
if (globalvar && Token::Match(tok, "%name% ("))
|
|
// TODO: Is global variable really changed by function call?
|
|
return tok;
|
|
// Is aliased function call
|
|
if (Token::Match(tok, "%var% (") && std::any_of(tok->values().begin(), tok->values().end(), std::mem_fn(&ValueFlow::Value::isLifetimeValue))) {
|
|
bool aliased = false;
|
|
// If we can't find the expression then assume it was modified
|
|
if (!getExprTok())
|
|
return tok;
|
|
visitAstNodes(getExprTok(), [&](const Token* childTok) {
|
|
if (childTok->varId() > 0 && isAliasOf(tok, childTok->varId())) {
|
|
aliased = true;
|
|
return ChildrenToVisit::done;
|
|
}
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
// TODO: Try to traverse the lambda function
|
|
if (aliased)
|
|
return tok;
|
|
}
|
|
continue;
|
|
}
|
|
if (isVariableChanged(tok, indirect, settings, cpp, depth))
|
|
return tok;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
const Token* findVariableChanged(const Token *start, const Token *end, int indirect, const nonneg int exprid, bool globalvar, const Settings *settings, bool cpp, int depth)
|
|
{
|
|
return findVariableChanged(const_cast<Token*>(start), end, indirect, exprid, globalvar, settings, cpp, depth);
|
|
}
|
|
|
|
bool isVariableChanged(const Variable * var, const Settings *settings, bool cpp, int depth)
|
|
{
|
|
if (!var)
|
|
return false;
|
|
if (!var->scope())
|
|
return false;
|
|
const Token * start = var->declEndToken();
|
|
if (!start)
|
|
return false;
|
|
if (Token::Match(start, "; %varid% =", var->declarationId()))
|
|
start = start->tokAt(2);
|
|
return isVariableChanged(start->next(), var->scope()->bodyEnd, var->declarationId(), var->isGlobal(), settings, cpp, depth);
|
|
}
|
|
|
|
bool isVariablesChanged(const Token* start,
|
|
const Token* end,
|
|
int indirect,
|
|
std::vector<const Variable*> vars,
|
|
const Settings* settings,
|
|
bool cpp)
|
|
{
|
|
std::set<int> varids;
|
|
std::transform(vars.begin(), vars.end(), std::inserter(varids, varids.begin()), [](const Variable* var) {
|
|
return var->declarationId();
|
|
});
|
|
const bool globalvar = std::any_of(vars.begin(), vars.end(), [](const Variable* var) {
|
|
return var->isGlobal();
|
|
});
|
|
for (const Token* tok = start; tok != end; tok = tok->next()) {
|
|
if (tok->varId() == 0 || varids.count(tok->varId()) == 0) {
|
|
if (globalvar && Token::Match(tok, "%name% ("))
|
|
// TODO: Is global variable really changed by function call?
|
|
return true;
|
|
continue;
|
|
}
|
|
if (isVariableChanged(tok, indirect, settings, cpp))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isThisChanged(const Token* start, const Token* end, int indirect, const Settings* settings, bool cpp)
|
|
{
|
|
if (!precedes(start, end))
|
|
return false;
|
|
for (const Token* tok = start; tok != end; tok = tok->next()) {
|
|
if (!exprDependsOnThis(tok))
|
|
continue;
|
|
if (Token::Match(tok->previous(), "%name% (")) {
|
|
if (tok->previous()->function()) {
|
|
if (!tok->previous()->function()->isConst())
|
|
return true;
|
|
else
|
|
continue;
|
|
} else if (!tok->previous()->isKeyword()) {
|
|
return true;
|
|
}
|
|
}
|
|
if (isVariableChanged(tok, indirect, settings, cpp))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isExpressionChanged(const Token* expr, const Token* start, const Token* end, const Settings* settings, bool cpp, int depth)
|
|
{
|
|
if (!precedes(start, end))
|
|
return false;
|
|
const Token* result = findAstNode(expr, [&](const Token* tok) {
|
|
if (exprDependsOnThis(tok) && isThisChanged(start, end, false, settings, cpp)) {
|
|
return true;
|
|
}
|
|
bool global = false;
|
|
if (tok->variable()) {
|
|
if (tok->variable()->isConst())
|
|
return false;
|
|
global = !tok->variable()->isLocal() && !tok->variable()->isArgument();
|
|
}
|
|
if (tok->exprId() > 0 &&
|
|
isVariableChanged(
|
|
start, end, tok->valueType() ? tok->valueType()->pointer : 0, tok->exprId(), global, settings, cpp, depth))
|
|
return true;
|
|
return false;
|
|
});
|
|
return result;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
std::vector<const Token *> getArguments(const Token *ftok)
|
|
{
|
|
const Token* tok = ftok;
|
|
if (Token::Match(tok, "%name% (|{"))
|
|
tok = ftok->next();
|
|
if (!Token::Match(tok, "(|{|["))
|
|
return std::vector<const Token *> {};
|
|
const Token *startTok = tok->astOperand2();
|
|
if (!startTok && tok->next() != tok->link())
|
|
startTok = tok->astOperand1();
|
|
return astFlatten(startTok, ",");
|
|
}
|
|
|
|
int getArgumentPos(const Variable* var, const Function* f)
|
|
{
|
|
auto arg_it = std::find_if(f->argumentList.begin(), f->argumentList.end(), [&](const Variable& v) {
|
|
return v.nameToken() == var->nameToken();
|
|
});
|
|
if (arg_it == f->argumentList.end())
|
|
return -1;
|
|
return std::distance(f->argumentList.begin(), arg_it);
|
|
}
|
|
|
|
const Token *findLambdaStartToken(const Token *last)
|
|
{
|
|
if (!last || last->str() != "}")
|
|
return nullptr;
|
|
const Token* tok = last->link();
|
|
if (Token::simpleMatch(tok->astParent(), "("))
|
|
tok = tok->astParent();
|
|
if (Token::simpleMatch(tok->astParent(), "["))
|
|
return tok->astParent();
|
|
return nullptr;
|
|
}
|
|
|
|
template <class T>
|
|
T* findLambdaEndTokenGeneric(T* first)
|
|
{
|
|
if (!first || first->str() != "[")
|
|
return nullptr;
|
|
if (!Token::Match(first->link(), "] (|{"))
|
|
return nullptr;
|
|
if (first->astOperand1() != first->link()->next())
|
|
return nullptr;
|
|
const Token * tok = first;
|
|
|
|
if (tok->astOperand1() && tok->astOperand1()->str() == "(")
|
|
tok = tok->astOperand1();
|
|
if (tok->astOperand1() && tok->astOperand1()->str() == "{")
|
|
return tok->astOperand1()->link();
|
|
return nullptr;
|
|
}
|
|
|
|
const Token* findLambdaEndToken(const Token* first)
|
|
{
|
|
return findLambdaEndTokenGeneric(first);
|
|
}
|
|
Token* findLambdaEndToken(Token* first)
|
|
{
|
|
return findLambdaEndTokenGeneric(first);
|
|
}
|
|
|
|
bool isLikelyStream(bool cpp, const Token *stream)
|
|
{
|
|
if (!cpp)
|
|
return false;
|
|
|
|
if (!stream)
|
|
return false;
|
|
|
|
if (!Token::Match(stream->astParent(), "&|<<|>>") || !stream->astParent()->isBinaryOp())
|
|
return false;
|
|
|
|
if (stream->astParent()->astOperand1() != stream)
|
|
return false;
|
|
|
|
return !astIsIntegral(stream, false);
|
|
}
|
|
|
|
bool isLikelyStreamRead(bool cpp, const Token *op)
|
|
{
|
|
if (!cpp)
|
|
return false;
|
|
|
|
if (!Token::Match(op, "&|>>") || !op->isBinaryOp())
|
|
return false;
|
|
|
|
if (!Token::Match(op->astOperand2(), "%name%|.|*|[") && op->str() != op->astOperand2()->str())
|
|
return false;
|
|
|
|
const Token *parent = op;
|
|
while (parent->astParent() && parent->astParent()->str() == op->str())
|
|
parent = parent->astParent();
|
|
if (parent->astParent() && !Token::Match(parent->astParent(), "%oror%|&&|(|,|.|!"))
|
|
return false;
|
|
if (op->str() == "&" && parent->astParent())
|
|
return false;
|
|
if (!parent->astOperand1() || !parent->astOperand2())
|
|
return false;
|
|
return (!parent->astOperand1()->valueType() || !parent->astOperand1()->valueType()->isIntegral());
|
|
}
|
|
|
|
bool isCPPCast(const Token* tok)
|
|
{
|
|
return tok && Token::simpleMatch(tok->previous(), "> (") && tok->astOperand2() && tok->astOperand1() && isCPPCastKeyword(tok->astOperand1());
|
|
}
|
|
|
|
bool isConstVarExpression(const Token *tok, const char* skipMatch)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (skipMatch && Token::Match(tok, skipMatch))
|
|
return false;
|
|
if (Token::simpleMatch(tok->previous(), "sizeof ("))
|
|
return true;
|
|
if (Token::Match(tok->previous(), "%name% (")) {
|
|
if (Token::simpleMatch(tok->astOperand1(), ".") && !isConstVarExpression(tok->astOperand1(), skipMatch))
|
|
return false;
|
|
std::vector<const Token *> args = getArguments(tok);
|
|
return std::all_of(args.begin(), args.end(), [&](const Token* t) {
|
|
return isConstVarExpression(t, skipMatch);
|
|
});
|
|
}
|
|
if (isCPPCast(tok)) {
|
|
return isConstVarExpression(tok->astOperand2(), skipMatch);
|
|
}
|
|
if (Token::Match(tok, "( %type%"))
|
|
return isConstVarExpression(tok->astOperand1(), skipMatch);
|
|
if (tok->str() == "::" && tok->hasKnownValue())
|
|
return isConstVarExpression(tok->astOperand2(), skipMatch);
|
|
if (Token::Match(tok, "%cop%|[|.")) {
|
|
if (tok->astOperand1() && !isConstVarExpression(tok->astOperand1(), skipMatch))
|
|
return false;
|
|
if (tok->astOperand2() && !isConstVarExpression(tok->astOperand2(), skipMatch))
|
|
return false;
|
|
return true;
|
|
}
|
|
if (Token::Match(tok, "%bool%|%num%|%str%|%char%|nullptr|NULL"))
|
|
return true;
|
|
if (tok->isEnumerator())
|
|
return true;
|
|
if (tok->variable())
|
|
return tok->variable()->isConst() && tok->variable()->nameToken() && tok->variable()->nameToken()->hasKnownValue();
|
|
return false;
|
|
}
|
|
|
|
static void getLHSVariablesRecursive(std::vector<const Variable*>& vars, const Token* tok)
|
|
{
|
|
if (!tok)
|
|
return;
|
|
if (vars.empty() && Token::Match(tok, "*|&|&&|[")) {
|
|
getLHSVariablesRecursive(vars, tok->astOperand1());
|
|
if (!vars.empty() || Token::simpleMatch(tok, "["))
|
|
return;
|
|
getLHSVariablesRecursive(vars, tok->astOperand2());
|
|
} else if (Token::Match(tok->previous(), "this . %var%")) {
|
|
getLHSVariablesRecursive(vars, tok->next());
|
|
} else if (Token::simpleMatch(tok, ".")) {
|
|
getLHSVariablesRecursive(vars, tok->astOperand1());
|
|
getLHSVariablesRecursive(vars, tok->astOperand2());
|
|
} else if (tok->variable()) {
|
|
vars.push_back(tok->variable());
|
|
}
|
|
}
|
|
|
|
std::vector<const Variable*> getLHSVariables(const Token* tok)
|
|
{
|
|
std::vector<const Variable*> result;
|
|
if (!Token::Match(tok, "%assign%"))
|
|
return result;
|
|
if (!tok->astOperand1())
|
|
return result;
|
|
if (tok->astOperand1()->varId() > 0 && tok->astOperand1()->variable())
|
|
return {tok->astOperand1()->variable()};
|
|
getLHSVariablesRecursive(result, tok->astOperand1());
|
|
return result;
|
|
}
|
|
|
|
static const Variable *getLHSVariableRecursive(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return nullptr;
|
|
if (Token::Match(tok, "*|&|&&|[")) {
|
|
const Variable *var = getLHSVariableRecursive(tok->astOperand1());
|
|
if (var || Token::simpleMatch(tok, "["))
|
|
return var;
|
|
return getLHSVariableRecursive(tok->astOperand2());
|
|
}
|
|
if (Token::Match(tok->previous(), "this . %var%"))
|
|
return tok->next()->variable();
|
|
return tok->variable();
|
|
}
|
|
|
|
const Variable *getLHSVariable(const Token *tok)
|
|
{
|
|
if (!Token::Match(tok, "%assign%"))
|
|
return nullptr;
|
|
if (!tok->astOperand1())
|
|
return nullptr;
|
|
if (tok->astOperand1()->varId() > 0 && tok->astOperand1()->variable())
|
|
return tok->astOperand1()->variable();
|
|
return getLHSVariableRecursive(tok->astOperand1());
|
|
}
|
|
|
|
static bool nonLocal(const Variable* var, bool deref)
|
|
{
|
|
return !var || (!var->isLocal() && !var->isArgument()) || (deref && var->isArgument() && var->isPointer()) || var->isStatic() || var->isReference() || var->isExtern();
|
|
}
|
|
|
|
static bool hasGccCompoundStatement(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (tok->str() == "{" && Token::simpleMatch(tok->previous(), "( {"))
|
|
return true;
|
|
return hasGccCompoundStatement(tok->astOperand1()) || hasGccCompoundStatement(tok->astOperand2());
|
|
}
|
|
|
|
static bool hasFunctionCall(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (Token::Match(tok, "%name% ("))
|
|
// todo, const/pure function?
|
|
return true;
|
|
return hasFunctionCall(tok->astOperand1()) || hasFunctionCall(tok->astOperand2());
|
|
}
|
|
|
|
static bool isUnchanged(const Token *startToken, const Token *endToken, const std::set<int> &exprVarIds, bool local)
|
|
{
|
|
for (const Token *tok = startToken; tok != endToken; tok = tok->next()) {
|
|
if (!local && Token::Match(tok, "%name% (") && !Token::simpleMatch(tok->linkAt(1), ") {"))
|
|
// TODO: this is a quick bailout
|
|
return false;
|
|
if (tok->varId() <= 0 || exprVarIds.find(tok->varId()) == exprVarIds.end())
|
|
continue;
|
|
const Token *parent = tok;
|
|
while (parent->astParent() && !parent->astParent()->isAssignmentOp() && parent->astParent()->tokType() != Token::Type::eIncDecOp) {
|
|
if (parent->str() == "," || parent->isUnaryOp("&"))
|
|
// TODO: This is a quick bailout
|
|
return false;
|
|
parent = parent->astParent();
|
|
}
|
|
if (parent->astParent()) {
|
|
if (parent->astParent()->tokType() == Token::Type::eIncDecOp)
|
|
return false;
|
|
else if (parent->astParent()->isAssignmentOp() && parent == parent->astParent()->astOperand1())
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool isNullOperand(const Token *expr)
|
|
{
|
|
if (!expr)
|
|
return false;
|
|
if (Token::Match(expr, "static_cast|const_cast|dynamic_cast|reinterpret_cast <"))
|
|
expr = expr->astParent();
|
|
else if (!expr->isCast())
|
|
return Token::Match(expr, "NULL|nullptr");
|
|
if (expr->valueType() && expr->valueType()->pointer == 0)
|
|
return false;
|
|
const Token *castOp = expr->astOperand2() ? expr->astOperand2() : expr->astOperand1();
|
|
return Token::Match(castOp, "NULL|nullptr") || (MathLib::isInt(castOp->str()) && MathLib::isNullValue(castOp->str()));
|
|
}
|
|
|
|
bool isGlobalData(const Token *expr, bool cpp)
|
|
{
|
|
bool globalData = false;
|
|
visitAstNodes(expr,
|
|
[&](const Token *tok) {
|
|
if (tok->varId() && !tok->variable()) {
|
|
// Bailout, this is probably global
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->originalName() == "->") {
|
|
// TODO check if pointer points at local data
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
} else if (Token::Match(tok, "[*[]") && tok->astOperand1() && tok->astOperand1()->variable()) {
|
|
// TODO check if pointer points at local data
|
|
const Variable *lhsvar = tok->astOperand1()->variable();
|
|
const ValueType *lhstype = tok->astOperand1()->valueType();
|
|
if (lhsvar->isPointer()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
} else if (lhsvar->isArgument() && lhsvar->isArray()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
} else if (lhsvar->isArgument() && (!lhstype || (lhstype->type <= ValueType::Type::VOID && !lhstype->container))) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
}
|
|
if (tok->varId() == 0 && tok->isName() && tok->previous()->str() != ".") {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()) {
|
|
// TODO : Check references
|
|
if (tok->variable()->isReference() && tok != tok->variable()->nameToken()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()->isExtern()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->previous()->str() != "." && !tok->variable()->isLocal() && !tok->variable()->isArgument()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()->isArgument() && tok->variable()->isPointer() && tok != expr) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()->isPointerArray()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
}
|
|
// Unknown argument type => it might be some reference type..
|
|
if (cpp && tok->str() == "." && tok->astOperand1() && tok->astOperand1()->variable() && !tok->astOperand1()->valueType()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (Token::Match(tok, ".|["))
|
|
return ChildrenToVisit::op1;
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
return globalData;
|
|
}
|
|
|
|
struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<int> &exprVarIds, bool local, bool inInnerClass, int depth)
|
|
{
|
|
// Parse the given tokens
|
|
if (++depth > 1000)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
for (const Token* tok = startToken; precedes(tok, endToken); tok = tok->next()) {
|
|
if (Token::simpleMatch(tok, "try {")) {
|
|
// TODO: handle try
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, "break ;")) {
|
|
return Result(Result::Type::BREAK, tok);
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, "goto"))
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (!inInnerClass && tok->str() == "{" && tok->scope()->isClassOrStruct()) {
|
|
// skip returns from local class definition
|
|
FwdAnalysis::Result result = checkRecursive(expr, tok, tok->link(), exprVarIds, local, true, depth);
|
|
if (result.type != Result::Type::NONE)
|
|
return result;
|
|
tok=tok->link();
|
|
}
|
|
|
|
if (tok->str() == "continue")
|
|
// TODO
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (const Token *lambdaEndToken = findLambdaEndToken(tok)) {
|
|
tok = lambdaEndToken;
|
|
const Result lambdaResult = checkRecursive(expr, lambdaEndToken->link()->next(), lambdaEndToken, exprVarIds, local, inInnerClass, depth);
|
|
if (lambdaResult.type == Result::Type::READ || lambdaResult.type == Result::Type::BAILOUT)
|
|
return lambdaResult;
|
|
}
|
|
|
|
if (Token::Match(tok, "return|throw")) {
|
|
// TODO: Handle these better
|
|
// Is expr variable used in expression?
|
|
|
|
const Token* opTok = tok->astOperand1();
|
|
if (!opTok)
|
|
opTok = tok->next();
|
|
std::pair<const Token*, const Token*> startEndTokens = opTok->findExpressionStartEndTokens();
|
|
FwdAnalysis::Result result =
|
|
checkRecursive(expr, startEndTokens.first, startEndTokens.second->next(), exprVarIds, local, true, depth);
|
|
if (result.type != Result::Type::NONE)
|
|
return result;
|
|
|
|
// #9167: if the return is inside an inner class, it does not tell us anything
|
|
if (!inInnerClass) {
|
|
if (!local && mWhat == What::Reassign)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
return Result(Result::Type::RETURN);
|
|
}
|
|
}
|
|
|
|
if (tok->str() == "}") {
|
|
// Known value => possible value
|
|
if (tok->scope() == expr->scope())
|
|
mValueFlowKnown = false;
|
|
|
|
if (tok->scope()->isLoopScope()) {
|
|
// check condition
|
|
const Token *conditionStart = nullptr;
|
|
const Token *conditionEnd = nullptr;
|
|
if (Token::simpleMatch(tok->link()->previous(), ") {")) {
|
|
conditionEnd = tok->link()->previous();
|
|
conditionStart = conditionEnd->link();
|
|
} else if (Token::simpleMatch(tok->link()->previous(), "do {") && Token::simpleMatch(tok, "} while (")) {
|
|
conditionStart = tok->tokAt(2);
|
|
conditionEnd = conditionStart->link();
|
|
}
|
|
if (conditionStart && conditionEnd) {
|
|
bool used = false;
|
|
for (const Token *condTok = conditionStart; condTok != conditionEnd; condTok = condTok->next()) {
|
|
if (exprVarIds.find(condTok->varId()) != exprVarIds.end()) {
|
|
used = true;
|
|
break;
|
|
}
|
|
}
|
|
if (used)
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
// check loop body again..
|
|
const struct FwdAnalysis::Result &result = checkRecursive(expr, tok->link(), tok, exprVarIds, local, inInnerClass, depth);
|
|
if (result.type == Result::Type::BAILOUT || result.type == Result::Type::READ)
|
|
return result;
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, "else {"))
|
|
tok = tok->linkAt(1);
|
|
|
|
if (Token::simpleMatch(tok, "asm ("))
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (mWhat == What::ValueFlow && (Token::Match(tok, "while|for (") || Token::simpleMatch(tok, "do {"))) {
|
|
const Token *bodyStart = nullptr;
|
|
const Token *conditionStart = nullptr;
|
|
if (Token::simpleMatch(tok, "do {")) {
|
|
bodyStart = tok->next();
|
|
if (Token::simpleMatch(bodyStart->link(), "} while ("))
|
|
conditionStart = bodyStart->link()->tokAt(2);
|
|
} else {
|
|
conditionStart = tok->next();
|
|
if (Token::simpleMatch(conditionStart->link(), ") {"))
|
|
bodyStart = conditionStart->link()->next();
|
|
}
|
|
|
|
if (!bodyStart || !conditionStart)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
// Is expr changed in condition?
|
|
if (!isUnchanged(conditionStart, conditionStart->link(), exprVarIds, local))
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
// Is expr changed in loop body?
|
|
if (!isUnchanged(bodyStart, bodyStart->link(), exprVarIds, local))
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (mWhat == What::ValueFlow && Token::simpleMatch(tok, "if (") && Token::simpleMatch(tok->linkAt(1), ") {")) {
|
|
const Token *bodyStart = tok->linkAt(1)->next();
|
|
const Token *conditionStart = tok->next();
|
|
const Token *condTok = conditionStart->astOperand2();
|
|
if (condTok->hasKnownIntValue()) {
|
|
bool cond = condTok->values().front().intvalue;
|
|
if (cond) {
|
|
FwdAnalysis::Result result = checkRecursive(expr, bodyStart, bodyStart->link(), exprVarIds, local, true, depth);
|
|
if (result.type != Result::Type::NONE)
|
|
return result;
|
|
} else if (Token::simpleMatch(bodyStart->link(), "} else {")) {
|
|
bodyStart = bodyStart->link()->tokAt(2);
|
|
FwdAnalysis::Result result = checkRecursive(expr, bodyStart, bodyStart->link(), exprVarIds, local, true, depth);
|
|
if (result.type != Result::Type::NONE)
|
|
return result;
|
|
}
|
|
}
|
|
tok = bodyStart->link();
|
|
if (isReturnScope(tok, &mLibrary))
|
|
return Result(Result::Type::BAILOUT);
|
|
if (Token::simpleMatch(tok, "} else {"))
|
|
tok = tok->linkAt(2);
|
|
if (!tok)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
// Is expr changed in condition?
|
|
if (!isUnchanged(conditionStart, conditionStart->link(), exprVarIds, local))
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
// Is expr changed in condition body?
|
|
if (!isUnchanged(bodyStart, bodyStart->link(), exprVarIds, local))
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (!local && Token::Match(tok, "%name% (") && !Token::simpleMatch(tok->linkAt(1), ") {")) {
|
|
// TODO: this is a quick bailout
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (mWhat == What::Reassign &&
|
|
Token::simpleMatch(tok, ";") &&
|
|
Token::simpleMatch(tok->astParent(), ";") &&
|
|
Token::simpleMatch(tok->astParent()->astParent(), "(") &&
|
|
Token::simpleMatch(tok->astParent()->astParent()->previous(), "for (") &&
|
|
!isUnchanged(tok, tok->astParent()->astParent()->link(), exprVarIds, local))
|
|
// TODO: This is a quick bailout to avoid FP #9420, there are false negatives (TODO_ASSERT_EQUALS)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (expr->isName() && Token::Match(tok, "%name% (") && tok->str().find("<") != std::string::npos && tok->str().find(expr->str()) != std::string::npos)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (exprVarIds.find(tok->varId()) != exprVarIds.end()) {
|
|
const Token *parent = tok;
|
|
bool other = false;
|
|
bool same = tok->astParent() && isSameExpression(mCpp, false, expr, tok, mLibrary, true, false, nullptr);
|
|
while (!same && Token::Match(parent->astParent(), "*|.|::|[|(|%cop%")) {
|
|
parent = parent->astParent();
|
|
if (parent && isSameExpression(mCpp, false, expr, parent, mLibrary, true, false, nullptr)) {
|
|
same = true;
|
|
if (mWhat == What::ValueFlow) {
|
|
KnownAndToken v;
|
|
v.known = mValueFlowKnown;
|
|
v.token = parent;
|
|
mValueFlow.push_back(v);
|
|
}
|
|
}
|
|
if (Token::Match(parent, ". %var%") && parent->next()->varId() && exprVarIds.find(parent->next()->varId()) == exprVarIds.end()) {
|
|
other = true;
|
|
break;
|
|
}
|
|
}
|
|
if (mWhat != What::ValueFlow && same && Token::simpleMatch(parent->astParent(), "[") && parent == parent->astParent()->astOperand2()) {
|
|
return Result(Result::Type::READ);
|
|
}
|
|
if (other)
|
|
continue;
|
|
if (Token::simpleMatch(parent->astParent(), "=") && parent == parent->astParent()->astOperand1()) {
|
|
if (!local && hasFunctionCall(parent->astParent()->astOperand2())) {
|
|
// TODO: this is a quick bailout
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
if (hasOperand(parent->astParent()->astOperand2(), expr)) {
|
|
if (mWhat == What::Reassign)
|
|
return Result(Result::Type::READ);
|
|
continue;
|
|
}
|
|
// ({ .. })
|
|
if (hasGccCompoundStatement(parent->astParent()->astOperand2()))
|
|
return Result(Result::Type::BAILOUT);
|
|
const bool reassign = isSameExpression(mCpp, false, expr, parent, mLibrary, false, false, nullptr);
|
|
if (reassign)
|
|
return Result(Result::Type::WRITE, parent->astParent());
|
|
return Result(Result::Type::READ);
|
|
} else if (mWhat == What::Reassign && parent->valueType() && parent->valueType()->pointer && Token::Match(parent->astParent(), "%assign%") && parent == parent->astParent()->astOperand1()) {
|
|
return Result(Result::Type::READ);
|
|
} else if (Token::Match(parent->astParent(), "%assign%") && !parent->astParent()->astParent() && parent == parent->astParent()->astOperand1()) {
|
|
if (mWhat == What::Reassign)
|
|
return Result(Result::Type::BAILOUT, parent->astParent());
|
|
continue;
|
|
} else {
|
|
// TODO: this is a quick bailout
|
|
return Result(Result::Type::BAILOUT, parent->astParent());
|
|
}
|
|
}
|
|
|
|
if (Token::Match(tok, ")|do {")) {
|
|
if (tok->str() == ")" && Token::simpleMatch(tok->link()->previous(), "switch ("))
|
|
// TODO: parse switch
|
|
return Result(Result::Type::BAILOUT);
|
|
const Result &result1 = checkRecursive(expr, tok->tokAt(2), tok->linkAt(1), exprVarIds, local, inInnerClass, depth);
|
|
if (result1.type == Result::Type::READ || result1.type == Result::Type::BAILOUT)
|
|
return result1;
|
|
if (mWhat == What::ValueFlow && result1.type == Result::Type::WRITE)
|
|
mValueFlowKnown = false;
|
|
if (mWhat == What::Reassign && result1.type == Result::Type::BREAK) {
|
|
const Token *scopeEndToken = findNextTokenFromBreak(result1.token);
|
|
if (scopeEndToken) {
|
|
const Result &result2 = checkRecursive(expr, scopeEndToken->next(), endToken, exprVarIds, local, inInnerClass, depth);
|
|
if (result2.type == Result::Type::BAILOUT)
|
|
return result2;
|
|
}
|
|
}
|
|
if (Token::simpleMatch(tok->linkAt(1), "} else {")) {
|
|
const Token *elseStart = tok->linkAt(1)->tokAt(2);
|
|
const Result &result2 = checkRecursive(expr, elseStart, elseStart->link(), exprVarIds, local, inInnerClass, depth);
|
|
if (mWhat == What::ValueFlow && result2.type == Result::Type::WRITE)
|
|
mValueFlowKnown = false;
|
|
if (result2.type == Result::Type::READ || result2.type == Result::Type::BAILOUT)
|
|
return result2;
|
|
if (result1.type == Result::Type::WRITE && result2.type == Result::Type::WRITE)
|
|
return result1;
|
|
tok = elseStart->link();
|
|
} else {
|
|
tok = tok->linkAt(1);
|
|
}
|
|
}
|
|
}
|
|
|
|
return Result(Result::Type::NONE);
|
|
}
|
|
|
|
static bool hasVolatileCastOrVar(const Token *expr)
|
|
{
|
|
bool ret = false;
|
|
visitAstNodes(expr,
|
|
[&ret](const Token *tok) {
|
|
if (Token::simpleMatch(tok, "( volatile"))
|
|
ret = true;
|
|
else if (tok->variable() && tok->variable()->isVolatile())
|
|
ret = true;
|
|
return ret ? ChildrenToVisit::none : ChildrenToVisit::op1_and_op2;
|
|
});
|
|
return ret;
|
|
}
|
|
|
|
bool FwdAnalysis::isGlobalData(const Token *expr) const
|
|
{
|
|
return ::isGlobalData(expr, mCpp);
|
|
}
|
|
|
|
std::set<int> FwdAnalysis::getExprVarIds(const Token* expr, bool* localOut, bool* unknownVarIdOut) const
|
|
{
|
|
// all variable ids in expr.
|
|
std::set<int> exprVarIds;
|
|
bool local = true;
|
|
bool unknownVarId = false;
|
|
visitAstNodes(expr,
|
|
[&](const Token *tok) {
|
|
if (tok->varId() == 0 && tok->isName() && tok->previous()->str() != ".") {
|
|
// unknown variable
|
|
unknownVarId = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->varId() > 0) {
|
|
exprVarIds.insert(tok->varId());
|
|
if (!Token::simpleMatch(tok->previous(), ".")) {
|
|
const Variable *var = tok->variable();
|
|
if (var && var->isReference() && var->isLocal() && Token::Match(var->nameToken(), "%var% [=(]") && !isGlobalData(var->nameToken()->next()->astOperand2()))
|
|
return ChildrenToVisit::none;
|
|
const bool deref = tok->astParent() && (tok->astParent()->isUnaryOp("*") || (tok->astParent()->str() == "[" && tok == tok->astParent()->astOperand1()));
|
|
local &= !nonLocal(tok->variable(), deref);
|
|
}
|
|
}
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
if (localOut)
|
|
*localOut = local;
|
|
if (unknownVarIdOut)
|
|
*unknownVarIdOut = unknownVarId;
|
|
return exprVarIds;
|
|
}
|
|
|
|
FwdAnalysis::Result FwdAnalysis::check(const Token* expr, const Token* startToken, const Token* endToken)
|
|
{
|
|
// all variable ids in expr.
|
|
bool local = true;
|
|
bool unknownVarId = false;
|
|
std::set<int> exprVarIds = getExprVarIds(expr, &local, &unknownVarId);
|
|
|
|
if (unknownVarId)
|
|
return Result(FwdAnalysis::Result::Type::BAILOUT);
|
|
|
|
if (mWhat == What::Reassign && isGlobalData(expr))
|
|
local = false;
|
|
|
|
// In unused values checking we do not want to check assignments to
|
|
// global data.
|
|
if (mWhat == What::UnusedValue && isGlobalData(expr))
|
|
return Result(FwdAnalysis::Result::Type::BAILOUT);
|
|
|
|
Result result = checkRecursive(expr, startToken, endToken, exprVarIds, local, false);
|
|
|
|
// Break => continue checking in outer scope
|
|
while (mWhat!=What::ValueFlow && result.type == FwdAnalysis::Result::Type::BREAK) {
|
|
const Token *scopeEndToken = findNextTokenFromBreak(result.token);
|
|
if (!scopeEndToken)
|
|
break;
|
|
result = checkRecursive(expr, scopeEndToken->next(), endToken, exprVarIds, local, false);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
bool FwdAnalysis::hasOperand(const Token *tok, const Token *lhs) const
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (isSameExpression(mCpp, false, tok, lhs, mLibrary, false, false, nullptr))
|
|
return true;
|
|
return hasOperand(tok->astOperand1(), lhs) || hasOperand(tok->astOperand2(), lhs);
|
|
}
|
|
|
|
const Token *FwdAnalysis::reassign(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
if (hasVolatileCastOrVar(expr))
|
|
return nullptr;
|
|
mWhat = What::Reassign;
|
|
Result result = check(expr, startToken, endToken);
|
|
return result.type == FwdAnalysis::Result::Type::WRITE ? result.token : nullptr;
|
|
}
|
|
|
|
bool FwdAnalysis::unusedValue(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
if (isEscapedAlias(expr))
|
|
return false;
|
|
if (hasVolatileCastOrVar(expr))
|
|
return false;
|
|
mWhat = What::UnusedValue;
|
|
Result result = check(expr, startToken, endToken);
|
|
return (result.type == FwdAnalysis::Result::Type::NONE || result.type == FwdAnalysis::Result::Type::RETURN) && !possiblyAliased(expr, startToken);
|
|
}
|
|
|
|
std::vector<FwdAnalysis::KnownAndToken> FwdAnalysis::valueFlow(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
mWhat = What::ValueFlow;
|
|
mValueFlowKnown = true;
|
|
check(expr, startToken, endToken);
|
|
return mValueFlow;
|
|
}
|
|
|
|
bool FwdAnalysis::possiblyAliased(const Token *expr, const Token *startToken) const
|
|
{
|
|
if (expr->isUnaryOp("*"))
|
|
return true;
|
|
|
|
const bool macro = false;
|
|
const bool pure = false;
|
|
const bool followVar = false;
|
|
for (const Token *tok = startToken; tok; tok = tok->previous()) {
|
|
if (tok->str() == "{" && tok->scope()->type == Scope::eFunction)
|
|
break;
|
|
|
|
if (Token::Match(tok, "%name% (") && !Token::Match(tok, "if|while|for")) {
|
|
// Is argument passed by reference?
|
|
const std::vector<const Token*> args = getArguments(tok);
|
|
for (int argnr = 0; argnr < args.size(); ++argnr) {
|
|
if (!Token::Match(args[argnr], "%name%|.|::"))
|
|
continue;
|
|
if (tok->function() && tok->function()->getArgumentVar(argnr) && !tok->function()->getArgumentVar(argnr)->isReference() && !tok->function()->isConst())
|
|
continue;
|
|
for (const Token *subexpr = expr; subexpr; subexpr = subexpr->astOperand1()) {
|
|
if (isSameExpression(mCpp, macro, subexpr, args[argnr], mLibrary, pure, followVar))
|
|
return true;
|
|
}
|
|
}
|
|
continue;
|
|
}
|
|
|
|
const Token *addrOf = nullptr;
|
|
if (Token::Match(tok, "& %name% ="))
|
|
addrOf = tok->tokAt(2)->astOperand2();
|
|
else if (tok->isUnaryOp("&"))
|
|
addrOf = tok->astOperand1();
|
|
else if (Token::simpleMatch(tok, "std :: ref ("))
|
|
addrOf = tok->tokAt(3)->astOperand2();
|
|
else
|
|
continue;
|
|
|
|
for (const Token *subexpr = expr; subexpr; subexpr = subexpr->astOperand1()) {
|
|
if (isSameExpression(mCpp, macro, subexpr, addrOf, mLibrary, pure, followVar))
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool FwdAnalysis::isEscapedAlias(const Token* expr)
|
|
{
|
|
for (const Token *subexpr = expr; subexpr; subexpr = subexpr->astOperand1()) {
|
|
for (const ValueFlow::Value &val : subexpr->values()) {
|
|
if (!val.isLocalLifetimeValue())
|
|
continue;
|
|
const Variable* var = val.tokvalue->variable();
|
|
if (!var)
|
|
continue;
|
|
if (!var->isLocal())
|
|
return true;
|
|
if (var->isArgument())
|
|
return true;
|
|
|
|
}
|
|
}
|
|
return false;
|
|
}
|