1495 lines
61 KiB
C++
1495 lines
61 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2021 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 "checkuninitvar.h"
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#include "astutils.h"
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#include "checknullpointer.h" // CheckNullPointer::isPointerDeref
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#include "errorlogger.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 "tokenize.h"
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#include "valueflow.h"
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#include <cassert>
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#include <list>
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#include <map>
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#include <utility>
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namespace tinyxml2 {
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class XMLElement;
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}
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//---------------------------------------------------------------------------
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// Register this check class (by creating a static instance of it)
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namespace {
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CheckUninitVar instance;
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}
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//---------------------------------------------------------------------------
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// get ast parent, skip possible address-of and casts
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static const Token *getAstParentSkipPossibleCastAndAddressOf(const Token *vartok, bool *unknown)
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{
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if (unknown)
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*unknown = false;
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if (!vartok)
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return nullptr;
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const Token *parent = vartok->astParent();
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while (Token::Match(parent, ".|::"))
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parent = parent->astParent();
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if (!parent)
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return nullptr;
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if (parent->isUnaryOp("&"))
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parent = parent->astParent();
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else if (parent->str() == "&" && vartok == parent->astOperand2() && Token::Match(parent->astOperand1()->previous(), "( %type% )")) {
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parent = parent->astParent();
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if (unknown)
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*unknown = true;
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}
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while (parent && parent->isCast())
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parent = parent->astParent();
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return parent;
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}
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void CheckUninitVar::check()
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{
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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std::set<std::string> arrayTypeDefs;
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for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
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if (Token::Match(tok, "%name% [") && tok->variable() && Token::Match(tok->variable()->typeStartToken(), "%type% %var% ;"))
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arrayTypeDefs.insert(tok->variable()->typeStartToken()->str());
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}
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// check every executable scope
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for (const Scope &scope : symbolDatabase->scopeList) {
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if (scope.isExecutable()) {
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checkScope(&scope, arrayTypeDefs);
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}
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}
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}
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void CheckUninitVar::checkScope(const Scope* scope, const std::set<std::string> &arrayTypeDefs)
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{
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for (const Variable &var : scope->varlist) {
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if ((mTokenizer->isCPP() && var.type() && !var.isPointer() && var.type()->needInitialization != Type::NeedInitialization::True) ||
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var.isStatic() || var.isExtern() || var.isReference())
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continue;
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// don't warn for try/catch exception variable
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if (var.isThrow())
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continue;
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if (Token::Match(var.nameToken()->next(), "[({:]"))
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continue;
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if (Token::Match(var.nameToken(), "%name% =")) { // Variable is initialized, but Rhs might be not
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checkRhs(var.nameToken(), var, NO_ALLOC, 0U, emptyString);
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continue;
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}
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if (Token::Match(var.nameToken(), "%name% ) (") && Token::simpleMatch(var.nameToken()->linkAt(2), ") =")) { // Function pointer is initialized, but Rhs might be not
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checkRhs(var.nameToken()->linkAt(2)->next(), var, NO_ALLOC, 0U, emptyString);
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continue;
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}
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if (var.isArray() || var.isPointerToArray()) {
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const Token *tok = var.nameToken()->next();
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if (var.isPointerToArray())
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tok = tok->next();
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while (Token::simpleMatch(tok->link(), "] ["))
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tok = tok->link()->next();
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if (Token::Match(tok->link(), "] =|{"))
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continue;
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}
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bool stdtype = mTokenizer->isC() && arrayTypeDefs.find(var.typeStartToken()->str()) == arrayTypeDefs.end();
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const Token* tok = var.typeStartToken();
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for (; tok != var.nameToken() && tok->str() != "<"; tok = tok->next()) {
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if (tok->isStandardType() || tok->isEnumType())
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stdtype = true;
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}
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if (var.isArray() && !stdtype)
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continue;
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while (tok && tok->str() != ";")
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tok = tok->next();
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if (!tok)
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continue;
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if (tok->astParent() && Token::simpleMatch(tok->astParent()->previous(), "for (") &&
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checkLoopBody(tok->astParent()->link()->next(), var, var.isArray() ? ARRAY : NO_ALLOC, emptyString, true))
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continue;
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if (var.isArray()) {
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Alloc alloc = ARRAY;
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const std::map<nonneg int, VariableValue> variableValue;
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bool init = false;
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for (const Token *parent = var.nameToken(); parent; parent = parent->astParent()) {
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if (parent->str() == "=") {
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init = true;
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break;
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}
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}
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if (!init)
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checkScopeForVariable(tok, var, nullptr, nullptr, &alloc, emptyString, variableValue);
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continue;
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}
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if (stdtype || var.isPointer()) {
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Alloc alloc = NO_ALLOC;
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const std::map<nonneg int, VariableValue> variableValue;
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checkScopeForVariable(tok, var, nullptr, nullptr, &alloc, emptyString, variableValue);
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}
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if (var.type())
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checkStruct(tok, var);
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}
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if (scope->function) {
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for (const Variable &arg : scope->function->argumentList) {
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if (arg.declarationId() && Token::Match(arg.typeStartToken(), "%type% * %name% [,)]")) {
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// Treat the pointer as initialized until it is assigned by malloc
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for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
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if (!Token::Match(tok, "[;{}] %varid% =", arg.declarationId()))
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continue;
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const Token *allocFuncCallToken = findAllocFuncCallToken(tok->tokAt(2)->astOperand2(), mSettings->library);
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if (!allocFuncCallToken)
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continue;
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const Library::AllocFunc *allocFunc = mSettings->library.getAllocFuncInfo(allocFuncCallToken);
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if (!allocFunc || allocFunc->initData)
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continue;
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if (arg.typeStartToken()->strAt(-1) == "struct" || (arg.type() && arg.type()->isStructType()))
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checkStruct(tok, arg);
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else if (arg.typeStartToken()->isStandardType() || arg.typeStartToken()->isEnumType()) {
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Alloc alloc = NO_ALLOC;
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const std::map<nonneg int, VariableValue> variableValue;
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checkScopeForVariable(tok->next(), arg, nullptr, nullptr, &alloc, emptyString, variableValue);
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}
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}
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}
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}
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}
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}
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void CheckUninitVar::checkStruct(const Token *tok, const Variable &structvar)
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{
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const Token *typeToken = structvar.typeStartToken();
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const SymbolDatabase * symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope *scope2 : symbolDatabase->classAndStructScopes) {
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if (scope2->className == typeToken->str() && scope2->numConstructors == 0U) {
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for (const Variable &var : scope2->varlist) {
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if (var.isStatic() || var.hasDefault() || var.isArray() ||
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(!mTokenizer->isC() && var.isClass() && (!var.type() || var.type()->needInitialization != Type::NeedInitialization::True)))
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continue;
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// is the variable declared in a inner union?
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bool innerunion = false;
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for (const Scope *innerScope : scope2->nestedList) {
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if (innerScope->type == Scope::eUnion) {
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if (var.typeStartToken()->linenr() >= innerScope->bodyStart->linenr() &&
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var.typeStartToken()->linenr() <= innerScope->bodyEnd->linenr()) {
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innerunion = true;
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break;
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}
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}
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}
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if (!innerunion) {
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Alloc alloc = NO_ALLOC;
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const Token *tok2 = tok;
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if (tok->str() == "}")
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tok2 = tok2->next();
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const std::map<nonneg int, VariableValue> variableValue;
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checkScopeForVariable(tok2, structvar, nullptr, nullptr, &alloc, var.name(), variableValue);
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}
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}
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}
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}
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}
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static VariableValue operator!(VariableValue v)
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{
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v.notEqual = !v.notEqual;
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return v;
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}
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static bool operator==(const VariableValue & v, MathLib::bigint i)
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{
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return v.notEqual ? (i != v.value) : (i == v.value);
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}
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static bool operator!=(const VariableValue & v, MathLib::bigint i)
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{
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return v.notEqual ? (i == v.value) : (i != v.value);
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}
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static void conditionAlwaysTrueOrFalse(const Token *tok, const std::map<nonneg int, VariableValue> &variableValue, bool *alwaysTrue, bool *alwaysFalse)
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{
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if (!tok)
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return;
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if (tok->hasKnownIntValue()) {
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if (tok->getKnownIntValue() == 0)
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*alwaysFalse = true;
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else
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*alwaysTrue = true;
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return;
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}
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if (tok->isName() || tok->str() == ".") {
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while (tok && tok->str() == ".")
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tok = tok->astOperand2();
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const std::map<nonneg int, VariableValue>::const_iterator it = variableValue.find(tok ? tok->varId() : ~0U);
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if (it != variableValue.end()) {
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*alwaysTrue = (it->second != 0LL);
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*alwaysFalse = (it->second == 0LL);
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}
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}
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else if (tok->isComparisonOp()) {
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if (variableValue.empty()) {
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return;
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}
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const Token *vartok, *numtok;
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if (tok->astOperand2() && tok->astOperand2()->isNumber()) {
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vartok = tok->astOperand1();
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numtok = tok->astOperand2();
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} else if (tok->astOperand1() && tok->astOperand1()->isNumber()) {
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vartok = tok->astOperand2();
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numtok = tok->astOperand1();
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} else {
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return;
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}
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while (vartok && vartok->str() == ".")
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vartok = vartok->astOperand2();
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const std::map<nonneg int, VariableValue>::const_iterator it = variableValue.find(vartok ? vartok->varId() : ~0U);
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if (it == variableValue.end())
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return;
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if (tok->str() == "==")
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*alwaysTrue = (it->second == MathLib::toLongNumber(numtok->str()));
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else if (tok->str() == "!=")
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*alwaysTrue = (it->second != MathLib::toLongNumber(numtok->str()));
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else
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return;
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*alwaysFalse = !(*alwaysTrue);
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}
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else if (tok->str() == "!") {
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bool t=false,f=false;
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conditionAlwaysTrueOrFalse(tok->astOperand1(), variableValue, &t, &f);
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if (t||f) {
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*alwaysTrue = !t;
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*alwaysFalse = !f;
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}
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}
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else if (tok->str() == "||") {
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bool t1=false, f1=false;
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conditionAlwaysTrueOrFalse(tok->astOperand1(), variableValue, &t1, &f1);
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bool t2=false, f2=false;
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if (!t1)
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conditionAlwaysTrueOrFalse(tok->astOperand2(), variableValue, &t2, &f2);
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*alwaysTrue = (t1 || t2);
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*alwaysFalse = (f1 && f2);
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}
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else if (tok->str() == "&&") {
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bool t1=false, f1=false;
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conditionAlwaysTrueOrFalse(tok->astOperand1(), variableValue, &t1, &f1);
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bool t2=false, f2=false;
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if (!f1)
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conditionAlwaysTrueOrFalse(tok->astOperand2(), variableValue, &t2, &f2);
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*alwaysTrue = (t1 && t2);
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*alwaysFalse = (f1 || f2);
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}
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}
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static bool isVariableUsed(const Token *tok, const Variable& var)
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{
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if (!tok)
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return false;
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if (tok->str() == "&" && !tok->astOperand2())
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return false;
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if (tok->isConstOp())
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return isVariableUsed(tok->astOperand1(),var) || isVariableUsed(tok->astOperand2(),var);
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if (tok->varId() != var.declarationId())
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return false;
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if (!var.isArray())
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return true;
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const Token *parent = tok->astParent();
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while (Token::Match(parent, "[?:]"))
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parent = parent->astParent();
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// no dereference, then array is not "used"
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if (!Token::Match(parent, "*|["))
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return false;
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const Token *parent2 = parent->astParent();
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// TODO: handle function calls. There is a TODO assertion in TestUninitVar::uninitvar_arrays
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return !parent2 || parent2->isConstOp() || (parent2->str() == "=" && parent2->astOperand2() == parent);
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}
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bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn, Alloc* const alloc, const std::string &membervar, std::map<nonneg int, VariableValue> variableValue)
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{
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const bool suppressErrors(possibleInit && *possibleInit); // Assume that this is a variable delaratkon, rather than a fundef
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const bool printDebug = mSettings->debugwarnings;
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if (possibleInit)
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*possibleInit = false;
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int number_of_if = 0;
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if (var.declarationId() == 0U)
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return true;
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for (; tok; tok = tok->next()) {
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// End of scope..
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if (tok->str() == "}") {
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if (number_of_if && possibleInit)
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*possibleInit = true;
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// might be a noreturn function..
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if (mTokenizer->isScopeNoReturn(tok)) {
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if (noreturn)
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*noreturn = true;
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return false;
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}
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break;
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}
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// Unconditional inner scope or try..
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if (tok->str() == "{" && Token::Match(tok->previous(), ",|;|{|}|try")) {
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if (checkScopeForVariable(tok->next(), var, possibleInit, noreturn, alloc, membervar, variableValue))
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return true;
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tok = tok->link();
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continue;
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}
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// assignment with nonzero constant..
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if (Token::Match(tok->previous(), "[;{}] %var% = - %name% ;"))
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variableValue[tok->varId()] = !VariableValue(0);
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// Inner scope..
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else if (Token::simpleMatch(tok, "if (")) {
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bool alwaysTrue = false;
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bool alwaysFalse = false;
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// Is variable assigned in condition?
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if (!membervar.empty()) {
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for (const Token *cond = tok->linkAt(1); cond != tok; cond = cond->previous()) {
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if (cond->varId() == var.declarationId() && isMemberVariableAssignment(cond, membervar))
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return true;
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}
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}
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conditionAlwaysTrueOrFalse(tok->next()->astOperand2(), variableValue, &alwaysTrue, &alwaysFalse);
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// initialization / usage in condition..
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if (!alwaysTrue && checkIfForWhileHead(tok->next(), var, suppressErrors, bool(number_of_if == 0), *alloc, membervar))
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return true;
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// checking if a not-zero variable is zero => bail out
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nonneg int condVarId = 0;
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VariableValue condVarValue(0);
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const Token *condVarTok = nullptr;
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if (alwaysFalse)
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;
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else if (Token::simpleMatch(tok, "if (") &&
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astIsVariableComparison(tok->next()->astOperand2(), "!=", "0", &condVarTok)) {
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const std::map<nonneg int,VariableValue>::const_iterator it = variableValue.find(condVarTok->varId());
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if (it != variableValue.end() && it->second != 0)
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return true; // this scope is not fully analysed => return true
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else {
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condVarId = condVarTok->varId();
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condVarValue = !VariableValue(0);
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}
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} else if (Token::simpleMatch(tok, "if (") && Token::Match(tok->next()->astOperand2(), "==|!=")) {
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const Token *condition = tok->next()->astOperand2();
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const Token *lhs = condition->astOperand1();
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const Token *rhs = condition->astOperand2();
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const Token *vartok = (lhs && lhs->hasKnownIntValue()) ? rhs : lhs;
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const Token *numtok = (lhs == vartok) ? rhs : lhs;
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while (Token::simpleMatch(vartok, "."))
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vartok = vartok->astOperand2();
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if (vartok && vartok->varId() && numtok && numtok->hasKnownIntValue()) {
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const std::map<nonneg int,VariableValue>::const_iterator it = variableValue.find(vartok->varId());
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if (it != variableValue.end() && it->second != numtok->getKnownIntValue())
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return true; // this scope is not fully analysed => return true
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condVarId = vartok->varId();
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condVarValue = VariableValue(numtok->getKnownIntValue());
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if (condition->str() == "!=")
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condVarValue = !condVarValue;
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}
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}
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// goto the {
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tok = tok->next()->link()->next();
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if (!tok)
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break;
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if (tok->str() == "{") {
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bool possibleInitIf((!alwaysTrue && number_of_if > 0) || suppressErrors);
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bool noreturnIf = false;
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const bool initif = !alwaysFalse && checkScopeForVariable(tok->next(), var, &possibleInitIf, &noreturnIf, alloc, membervar, variableValue);
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// bail out for such code:
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// if (a) x=0; // conditional initialization
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// if (b) return; // cppcheck doesn't know if b can be false when a is false.
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// x++; // it's possible x is always initialized
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if (!alwaysTrue && noreturnIf && number_of_if > 0) {
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if (printDebug) {
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std::string condition;
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for (const Token *tok2 = tok->linkAt(-1); tok2 != tok; tok2 = tok2->next()) {
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condition += tok2->str();
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if (tok2->isName() && tok2->next()->isName())
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condition += ' ';
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}
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reportError(tok, Severity::debug, "bailoutUninitVar", "bailout uninitialized variable checking for '" + var.name() + "'. can't determine if this condition can be false when previous condition is false: " + condition);
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}
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return true;
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}
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if (alwaysTrue && (initif || noreturnIf))
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return true;
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std::map<nonneg int, VariableValue> varValueIf;
|
|
if (!alwaysFalse && !initif && !noreturnIf) {
|
|
for (const Token *tok2 = tok; tok2 && tok2 != tok->link(); tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[;{}.] %name% = - %name% ;"))
|
|
varValueIf[tok2->next()->varId()] = !VariableValue(0);
|
|
else if (Token::Match(tok2, "[;{}.] %name% = %num% ;"))
|
|
varValueIf[tok2->next()->varId()] = VariableValue(MathLib::toLongNumber(tok2->strAt(3)));
|
|
}
|
|
}
|
|
|
|
if (initif && condVarId > 0)
|
|
variableValue[condVarId] = !condVarValue;
|
|
|
|
// goto the }
|
|
tok = tok->link();
|
|
|
|
if (!Token::simpleMatch(tok, "} else {")) {
|
|
if (initif || possibleInitIf) {
|
|
++number_of_if;
|
|
if (number_of_if >= 2)
|
|
return true;
|
|
}
|
|
} else {
|
|
// goto the {
|
|
tok = tok->tokAt(2);
|
|
|
|
bool possibleInitElse((!alwaysFalse && number_of_if > 0) || suppressErrors);
|
|
bool noreturnElse = false;
|
|
const bool initelse = !alwaysTrue && checkScopeForVariable(tok->next(), var, &possibleInitElse, &noreturnElse, alloc, membervar, variableValue);
|
|
|
|
std::map<nonneg int, VariableValue> varValueElse;
|
|
if (!alwaysTrue && !initelse && !noreturnElse) {
|
|
for (const Token *tok2 = tok; tok2 && tok2 != tok->link(); tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[;{}.] %var% = - %name% ;"))
|
|
varValueElse[tok2->next()->varId()] = !VariableValue(0);
|
|
else if (Token::Match(tok2, "[;{}.] %var% = %num% ;"))
|
|
varValueElse[tok2->next()->varId()] = VariableValue(MathLib::toLongNumber(tok2->strAt(3)));
|
|
}
|
|
}
|
|
|
|
if (initelse && condVarId > 0 && !noreturnIf && !noreturnElse)
|
|
variableValue[condVarId] = condVarValue;
|
|
|
|
// goto the }
|
|
tok = tok->link();
|
|
|
|
if ((alwaysFalse || initif || noreturnIf) &&
|
|
(alwaysTrue || initelse || noreturnElse))
|
|
return true;
|
|
|
|
if (initif || initelse || possibleInitElse)
|
|
++number_of_if;
|
|
if (!initif && !noreturnIf)
|
|
variableValue.insert(varValueIf.begin(), varValueIf.end());
|
|
if (!initelse && !noreturnElse)
|
|
variableValue.insert(varValueElse.begin(), varValueElse.end());
|
|
}
|
|
}
|
|
}
|
|
|
|
// = { .. }
|
|
else if (Token::simpleMatch(tok, "= {")) {
|
|
// end token
|
|
const Token *end = tok->next()->link();
|
|
|
|
// If address of variable is taken in the block then bail out
|
|
if (var.isPointer() || var.isArray()) {
|
|
if (Token::findmatch(tok->tokAt(2), "%varid%", end, var.declarationId()))
|
|
return true;
|
|
} else if (Token::findmatch(tok->tokAt(2), "& %varid%", end, var.declarationId())) {
|
|
return true;
|
|
}
|
|
|
|
const Token *errorToken = nullptr;
|
|
visitAstNodes(tok->next(),
|
|
[&](const Token *child) {
|
|
if (child->isUnaryOp("&"))
|
|
return ChildrenToVisit::none;
|
|
if (child->str() == "," || child->str() == "{" || child->isConstOp())
|
|
return ChildrenToVisit::op1_and_op2;
|
|
if (child->str() == "." && Token::Match(child->astOperand1(), "%varid%", var.declarationId()) && child->astOperand2() && child->astOperand2()->str() == membervar) {
|
|
errorToken = child;
|
|
return ChildrenToVisit::done;
|
|
}
|
|
return ChildrenToVisit::none;
|
|
});
|
|
|
|
if (errorToken) {
|
|
uninitStructMemberError(errorToken->astOperand2(), errorToken->astOperand1()->str() + "." + membervar);
|
|
return true;
|
|
}
|
|
|
|
// Skip block
|
|
tok = end;
|
|
continue;
|
|
}
|
|
|
|
// skip sizeof / offsetof
|
|
if (Token::Match(tok, "sizeof|typeof|offsetof|decltype ("))
|
|
tok = tok->linkAt(1);
|
|
|
|
// for/while..
|
|
else if (Token::Match(tok, "for|while (") || Token::simpleMatch(tok, "do {")) {
|
|
const bool forwhile = Token::Match(tok, "for|while (");
|
|
|
|
// is variable initialized in for-head?
|
|
if (forwhile && checkIfForWhileHead(tok->next(), var, tok->str() == "for", false, *alloc, membervar))
|
|
return true;
|
|
|
|
// goto the {
|
|
const Token *tok2 = forwhile ? tok->next()->link()->next() : tok->next();
|
|
|
|
if (tok2 && tok2->str() == "{") {
|
|
const bool init = checkLoopBody(tok2, var, *alloc, membervar, (number_of_if > 0) || suppressErrors);
|
|
|
|
// variable is initialized in the loop..
|
|
if (init)
|
|
return true;
|
|
|
|
// is variable used in for-head?
|
|
bool initcond = false;
|
|
if (!suppressErrors) {
|
|
const Token *startCond = forwhile ? tok->next() : tok->next()->link()->tokAt(2);
|
|
initcond = checkIfForWhileHead(startCond, var, false, bool(number_of_if == 0), *alloc, membervar);
|
|
}
|
|
|
|
// goto "}"
|
|
tok = tok2->link();
|
|
|
|
// do-while => goto ")"
|
|
if (!forwhile) {
|
|
// Assert that the tokens are '} while ('
|
|
if (!Token::simpleMatch(tok, "} while (")) {
|
|
if (printDebug)
|
|
reportError(tok,Severity::debug,"","assertion failed '} while ('");
|
|
break;
|
|
}
|
|
|
|
// Goto ')'
|
|
tok = tok->linkAt(2);
|
|
|
|
if (!tok)
|
|
// bailout : invalid code / bad tokenizer
|
|
break;
|
|
|
|
if (initcond)
|
|
// variable is initialized in while-condition
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Unknown or unhandled inner scope
|
|
else if (Token::simpleMatch(tok, ") {") || (Token::Match(tok, "%name% {") && tok->str() != "try")) {
|
|
if (tok->str() == "struct" || tok->str() == "union") {
|
|
tok = tok->linkAt(1);
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// bailout if there is ({
|
|
if (Token::simpleMatch(tok, "( {")) {
|
|
return true;
|
|
}
|
|
|
|
// bailout if there is assembler code or setjmp
|
|
if (Token::Match(tok, "asm|setjmp (")) {
|
|
return true;
|
|
}
|
|
|
|
// bailout if there is a goto label
|
|
if (Token::Match(tok, "[;{}] %name% :")) {
|
|
return true;
|
|
}
|
|
|
|
if (tok->str() == "?") {
|
|
if (!tok->astOperand2())
|
|
return true;
|
|
const bool used1 = isVariableUsed(tok->astOperand2()->astOperand1(), var);
|
|
const bool used0 = isVariableUsed(tok->astOperand2()->astOperand2(), var);
|
|
const bool err = (number_of_if == 0) ? (used1 || used0) : (used1 && used0);
|
|
if (err)
|
|
uninitvarError(tok, var.nameToken()->str(), *alloc);
|
|
|
|
// Todo: skip expression if there is no error
|
|
return true;
|
|
}
|
|
|
|
if (Token::Match(tok, "return|break|continue|throw|goto")) {
|
|
if (noreturn)
|
|
*noreturn = true;
|
|
|
|
tok = tok->next();
|
|
while (tok && tok->str() != ";") {
|
|
// variable is seen..
|
|
if (tok->varId() == var.declarationId()) {
|
|
if (!membervar.empty()) {
|
|
if (!suppressErrors && Token::Match(tok, "%name% . %name%") && tok->strAt(2) == membervar && Token::Match(tok->next()->astParent(), "%cop%|return|throw|?"))
|
|
uninitStructMemberError(tok, tok->str() + "." + membervar);
|
|
else if (mTokenizer->isCPP() && !suppressErrors && Token::Match(tok, "%name%") && Token::Match(tok->astParent(), "return|throw|?"))
|
|
uninitStructMemberError(tok, tok->str() + "." + membervar);
|
|
}
|
|
|
|
// Use variable
|
|
else if (!suppressErrors && isVariableUsage(tok, var.isPointer(), *alloc))
|
|
uninitvarError(tok, tok->str(), *alloc);
|
|
|
|
return true;
|
|
}
|
|
|
|
else if (Token::Match(tok, "sizeof|typeof|offsetof|decltype ("))
|
|
tok = tok->linkAt(1);
|
|
|
|
else if (tok->str() == "?") {
|
|
if (!tok->astOperand2())
|
|
return true;
|
|
const bool used1 = isVariableUsed(tok->astOperand2()->astOperand1(), var);
|
|
const bool used0 = isVariableUsed(tok->astOperand2()->astOperand2(), var);
|
|
const bool err = (number_of_if == 0) ? (used1 || used0) : (used1 && used0);
|
|
if (err)
|
|
uninitvarError(tok, var.nameToken()->str(), *alloc);
|
|
return true;
|
|
}
|
|
|
|
tok = tok->next();
|
|
}
|
|
|
|
return (noreturn == nullptr);
|
|
}
|
|
|
|
// variable is seen..
|
|
if (tok->varId() == var.declarationId()) {
|
|
// calling function that returns uninit data through pointer..
|
|
if (var.isPointer() && Token::simpleMatch(tok->next(), "=")) {
|
|
const Token *rhs = tok->next()->astOperand2();
|
|
while (rhs && rhs->isCast())
|
|
rhs = rhs->astOperand2() ? rhs->astOperand2() : rhs->astOperand1();
|
|
if (rhs && Token::Match(rhs->previous(), "%name% (")) {
|
|
const Library::AllocFunc *allocFunc = mSettings->library.getAllocFuncInfo(rhs->astOperand1());
|
|
if (allocFunc && !allocFunc->initData) {
|
|
*alloc = NO_CTOR_CALL;
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
if (mTokenizer->isCPP() && var.isPointer() && (var.typeStartToken()->isStandardType() || var.typeStartToken()->isEnumType() || (var.type() && var.type()->needInitialization == Type::NeedInitialization::True)) && Token::simpleMatch(tok->next(), "= new")) {
|
|
*alloc = CTOR_CALL;
|
|
|
|
// type has constructor(s)
|
|
if (var.typeScope() && var.typeScope()->numConstructors > 0)
|
|
return true;
|
|
|
|
// standard or enum type: check if new initializes the allocated memory
|
|
if (var.typeStartToken()->isStandardType() || var.typeStartToken()->isEnumType()) {
|
|
// scalar new with initialization
|
|
if (Token::Match(tok->next(), "= new %type% ("))
|
|
return true;
|
|
|
|
// array new
|
|
if (Token::Match(tok->next(), "= new %type% [") && Token::simpleMatch(tok->linkAt(4), "] ("))
|
|
return true;
|
|
}
|
|
|
|
continue;
|
|
}
|
|
|
|
|
|
if (!membervar.empty()) {
|
|
if (isMemberVariableAssignment(tok, membervar)) {
|
|
checkRhs(tok, var, *alloc, number_of_if, membervar);
|
|
return true;
|
|
}
|
|
|
|
if (isMemberVariableUsage(tok, var.isPointer(), *alloc, membervar)) {
|
|
uninitStructMemberError(tok, tok->str() + "." + membervar);
|
|
return true;
|
|
}
|
|
|
|
if (Token::Match(tok->previous(), "[(,] %name% [,)]"))
|
|
return true;
|
|
|
|
if (Token::Match(tok->previous(), "= %var% . %var% ;") && membervar == tok->strAt(2))
|
|
return true;
|
|
|
|
} else {
|
|
// Use variable
|
|
if (!suppressErrors && isVariableUsage(tok, var.isPointer(), *alloc)) {
|
|
uninitvarError(tok, tok->str(), *alloc);
|
|
return true;
|
|
}
|
|
|
|
else {
|
|
if (tok->strAt(1) == "=")
|
|
checkRhs(tok, var, *alloc, number_of_if, emptyString);
|
|
|
|
// assume that variable is assigned
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool CheckUninitVar::checkIfForWhileHead(const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit, Alloc alloc, const std::string &membervar)
|
|
{
|
|
const Token * const endpar = startparentheses->link();
|
|
if (Token::Match(startparentheses, "( ! %name% %oror%") && startparentheses->tokAt(2)->getValue(0))
|
|
suppressErrors = true;
|
|
for (const Token *tok = startparentheses->next(); tok && tok != endpar; tok = tok->next()) {
|
|
if (tok->varId() == var.declarationId()) {
|
|
if (Token::Match(tok, "%name% . %name%")) {
|
|
if (membervar.empty())
|
|
return true;
|
|
if (tok->strAt(2) == membervar) {
|
|
if (isMemberVariableAssignment(tok, membervar))
|
|
return true;
|
|
|
|
if (!suppressErrors && isMemberVariableUsage(tok, var.isPointer(), alloc, membervar))
|
|
uninitStructMemberError(tok, tok->str() + "." + membervar);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (isVariableUsage(tok, var.isPointer(), alloc)) {
|
|
if (suppressErrors)
|
|
continue;
|
|
uninitvarError(tok, tok->str(), alloc);
|
|
}
|
|
return true;
|
|
}
|
|
// skip sizeof / offsetof
|
|
if (Token::Match(tok, "sizeof|typeof|offsetof|decltype ("))
|
|
tok = tok->linkAt(1);
|
|
if ((!isuninit || !membervar.empty()) && tok->str() == "&&")
|
|
suppressErrors = true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/** recursively check loop, return error token */
|
|
const Token* CheckUninitVar::checkLoopBodyRecursive(const Token *start, const Variable& var, const Alloc alloc, const std::string &membervar, bool &bailout) const
|
|
{
|
|
assert(start->str() == "{");
|
|
|
|
const Token *errorToken = nullptr;
|
|
|
|
const Token *const end = start->link();
|
|
for (const Token *tok = start->next(); tok != end; tok = tok->next()) {
|
|
// skip sizeof / offsetof
|
|
if (Token::Match(tok, "sizeof|typeof|offsetof|decltype (")) {
|
|
tok = tok->linkAt(1);
|
|
continue;
|
|
}
|
|
|
|
if (Token::Match(tok, "asm ( %str% ) ;")) {
|
|
bailout = true;
|
|
return nullptr;
|
|
}
|
|
|
|
// for loop; skip third expression until loop body has been analyzed..
|
|
if (tok->str() == ";" && Token::simpleMatch(tok->astParent(), ";") && Token::simpleMatch(tok->astParent()->astParent(), "(")) {
|
|
const Token *top = tok->astParent()->astParent();
|
|
if (!Token::simpleMatch(top->previous(), "for (") || !Token::simpleMatch(top->link(), ") {"))
|
|
continue;
|
|
const Token *bodyStart = top->link()->next();
|
|
const Token *errorToken1 = checkLoopBodyRecursive(bodyStart, var, alloc, membervar, bailout);
|
|
if (errorToken1)
|
|
return errorToken1;
|
|
if (bailout)
|
|
return nullptr;
|
|
}
|
|
// for loop; skip loop body if there is third expression
|
|
if (Token::simpleMatch(tok, ") {") &&
|
|
Token::simpleMatch(tok->link()->previous(), "for (") &&
|
|
Token::simpleMatch(tok->link()->astOperand2(), ";") &&
|
|
Token::simpleMatch(tok->link()->astOperand2()->astOperand2(), ";")) {
|
|
tok = tok->linkAt(1);
|
|
}
|
|
|
|
if (tok->str() == "{") {
|
|
const Token *errorToken1 = checkLoopBodyRecursive(tok, var, alloc, membervar, bailout);
|
|
tok = tok->link();
|
|
if (Token::simpleMatch(tok, "} else {")) {
|
|
const Token *elseBody = tok->tokAt(2);
|
|
const Token *errorToken2 = checkLoopBodyRecursive(elseBody, var, alloc, membervar, bailout);
|
|
tok = elseBody->link();
|
|
if (errorToken1 && errorToken2)
|
|
return errorToken1;
|
|
if (errorToken2)
|
|
errorToken = errorToken2;
|
|
}
|
|
if (bailout)
|
|
return nullptr;
|
|
if (!errorToken)
|
|
errorToken = errorToken1;
|
|
}
|
|
|
|
if (tok->varId() != var.declarationId())
|
|
continue;
|
|
|
|
if (!membervar.empty()) {
|
|
if (isMemberVariableAssignment(tok, membervar)) {
|
|
bool assign = true;
|
|
bool rhs = false;
|
|
// Used for tracking if an ")" is inner or outer
|
|
const Token *rpar = nullptr;
|
|
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) {
|
|
if (tok2->str() == "=")
|
|
rhs = true;
|
|
|
|
// Look at inner expressions but not outer expressions
|
|
if (!rpar && tok2->str() == "(")
|
|
rpar = tok2->link();
|
|
else if (tok2->str() == ")") {
|
|
// No rpar => this is an outer right parenthesis
|
|
if (!rpar)
|
|
break;
|
|
if (rpar == tok2)
|
|
rpar = nullptr;
|
|
}
|
|
|
|
if (tok2->str() == ";" || (!rpar && tok2->str() == ","))
|
|
break;
|
|
if (rhs && tok2->varId() == var.declarationId() && isMemberVariableUsage(tok2, var.isPointer(), alloc, membervar)) {
|
|
assign = false;
|
|
break;
|
|
}
|
|
}
|
|
if (assign) {
|
|
bailout = true;
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
if (isMemberVariableUsage(tok, var.isPointer(), alloc, membervar))
|
|
return tok;
|
|
else if (Token::Match(tok->previous(), "[(,] %name% [,)]")) {
|
|
bailout = true;
|
|
return nullptr;
|
|
}
|
|
} else {
|
|
if (isVariableUsage(tok, var.isPointer(), alloc))
|
|
return tok;
|
|
else if (tok->strAt(1) == "=") {
|
|
bool varIsUsedInRhs = false;
|
|
visitAstNodes(tok->next()->astOperand2(), [&](const Token * t) {
|
|
if (!t)
|
|
return ChildrenToVisit::none;
|
|
if (t->varId() == var.declarationId()) {
|
|
varIsUsedInRhs = true;
|
|
return ChildrenToVisit::done;
|
|
}
|
|
if (Token::Match(t->previous(), "sizeof|typeof|offsetof|decltype ("))
|
|
return ChildrenToVisit::none;
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
if (!varIsUsedInRhs) {
|
|
bailout = true;
|
|
return nullptr;
|
|
}
|
|
} else {
|
|
bailout = true;
|
|
return nullptr;
|
|
}
|
|
}
|
|
}
|
|
|
|
return errorToken;
|
|
}
|
|
|
|
bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const Alloc alloc, const std::string &membervar, const bool suppressErrors)
|
|
{
|
|
bool bailout = false;
|
|
const Token *errorToken = checkLoopBodyRecursive(tok, var, alloc, membervar, bailout);
|
|
|
|
if (!suppressErrors && !bailout && errorToken) {
|
|
if (membervar.empty())
|
|
uninitvarError(errorToken, errorToken->str(), alloc);
|
|
else
|
|
uninitStructMemberError(errorToken, errorToken->str() + "." + membervar);
|
|
return true;
|
|
}
|
|
|
|
return bailout;
|
|
}
|
|
|
|
void CheckUninitVar::checkRhs(const Token *tok, const Variable &var, Alloc alloc, nonneg int number_of_if, const std::string &membervar)
|
|
{
|
|
bool rhs = false;
|
|
int indent = 0;
|
|
while (nullptr != (tok = tok->next())) {
|
|
if (tok->str() == "=")
|
|
rhs = true;
|
|
else if (rhs && tok->varId() == var.declarationId()) {
|
|
if (membervar.empty() && isVariableUsage(tok, var.isPointer(), alloc))
|
|
uninitvarError(tok, tok->str(), alloc);
|
|
else if (!membervar.empty() && isMemberVariableUsage(tok, var.isPointer(), alloc, membervar))
|
|
uninitStructMemberError(tok, tok->str() + "." + membervar);
|
|
else if (Token::Match(tok, "%var% ="))
|
|
break;
|
|
else if (Token::Match(tok->previous(), "[(,&]"))
|
|
break;
|
|
} else if (tok->str() == ";" || (indent==0 && tok->str() == ","))
|
|
break;
|
|
else if (tok->str() == "(")
|
|
++indent;
|
|
else if (tok->str() == ")") {
|
|
if (indent == 0)
|
|
break;
|
|
--indent;
|
|
} else if (tok->str() == "?" && tok->astOperand2()) {
|
|
const bool used1 = isVariableUsed(tok->astOperand2()->astOperand1(), var);
|
|
const bool used0 = isVariableUsed(tok->astOperand2()->astOperand2(), var);
|
|
const bool err = (number_of_if == 0) ? (used1 || used0) : (used1 && used0);
|
|
if (err)
|
|
uninitvarError(tok, var.nameToken()->str(), alloc);
|
|
break;
|
|
} else if (Token::Match(tok, "sizeof|typeof|offsetof|decltype ("))
|
|
tok = tok->linkAt(1);
|
|
|
|
}
|
|
}
|
|
|
|
static bool astIsLhs(const Token *tok)
|
|
{
|
|
return tok && tok->astParent() && tok == tok->astParent()->astOperand1();
|
|
}
|
|
|
|
static bool astIsRhs(const Token *tok)
|
|
{
|
|
return tok && tok->astParent() && tok == tok->astParent()->astOperand2();
|
|
}
|
|
|
|
const Token* CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, Alloc alloc, int indirect) const
|
|
{
|
|
const Token *valueExpr = vartok; // non-dereferenced , no address of value as variable
|
|
if (!pointer) {
|
|
if (Token::Match(vartok, "%name% [.(]") && vartok->variable() && !vartok->variable()->isPointer() && vartok->variable()->isClass())
|
|
return nullptr;
|
|
while (Token::simpleMatch(valueExpr->astParent(), ".") && astIsLhs(valueExpr) && valueExpr->astParent()->valueType() && valueExpr->astParent()->valueType()->pointer == 0)
|
|
valueExpr = valueExpr->astParent();
|
|
}
|
|
const Token *derefValue = nullptr; // dereferenced value expression
|
|
if (alloc != NO_ALLOC) {
|
|
const int arrayDim = (vartok->variable() && vartok->variable()->isArray()) ? vartok->variable()->dimensions().size() : 1;
|
|
int deref = 0;
|
|
derefValue = valueExpr;
|
|
while (Token::Match(derefValue->astParent(), "+|-|*|[|.") || (derefValue->astParent() && derefValue->astParent()->isCast())) {
|
|
if (derefValue->astParent()->isUnaryOp("*"))
|
|
++deref;
|
|
else if (derefValue->astParent()->str() == "[") {
|
|
if (astIsLhs(derefValue))
|
|
++deref;
|
|
else
|
|
break;
|
|
} else if (derefValue->astParent()->str() == ".")
|
|
++deref;
|
|
derefValue = derefValue->astParent();
|
|
if (deref < arrayDim)
|
|
valueExpr = derefValue;
|
|
}
|
|
if (deref < arrayDim) {
|
|
// todo compare deref with array dimensions
|
|
derefValue = nullptr;
|
|
}
|
|
} else if (vartok->astParent() && vartok->astParent()->isUnaryOp("&")) {
|
|
const Token *child = vartok->astParent();
|
|
const Token *parent = child->astParent();
|
|
while (parent && (parent->isCast() || parent->str() == "+")) {
|
|
child = parent;
|
|
parent = child->astParent();
|
|
}
|
|
if (parent && (parent->isUnaryOp("*") || (parent->str() == "[" && astIsLhs(child))))
|
|
derefValue = parent;
|
|
}
|
|
|
|
if (!valueExpr->astParent())
|
|
return nullptr;
|
|
|
|
// FIXME handle address of!!
|
|
if (valueExpr->astParent()->isUnaryOp("&"))
|
|
return nullptr;
|
|
if (derefValue && derefValue->astParent() && derefValue->astParent()->isUnaryOp("&"))
|
|
return nullptr;
|
|
|
|
// safe operations
|
|
if (alloc != NO_ALLOC) {
|
|
if (Token::Match(valueExpr->astParent(), "%comp%|%oror%|&&|?|!"))
|
|
return nullptr;
|
|
if (Token::Match(valueExpr->astParent(), "%or%|&") && valueExpr->astParent()->isBinaryOp())
|
|
return nullptr;
|
|
if (alloc == CTOR_CALL && derefValue && Token::simpleMatch(derefValue->astParent(), "(") && astIsLhs(derefValue))
|
|
return nullptr;
|
|
}
|
|
|
|
// Passing variable to function..
|
|
if (Token::Match(valueExpr->astParent(), "[(,]") && (valueExpr->astParent()->str() == "," || astIsRhs(valueExpr))) {
|
|
const Token *parent = valueExpr->astParent();
|
|
while (Token::simpleMatch(parent, ","))
|
|
parent = parent->astParent();
|
|
if (Token::simpleMatch(parent, "{"))
|
|
return valueExpr;
|
|
const int use = isFunctionParUsage(valueExpr, pointer, alloc, indirect);
|
|
return (use>0) ? valueExpr : nullptr;
|
|
}
|
|
if (derefValue && Token::Match(derefValue->astParent(), "[(,]") && (derefValue->astParent()->str() == "," || astIsRhs(derefValue))) {
|
|
const int use = isFunctionParUsage(derefValue, false, NO_ALLOC, indirect);
|
|
return (use>0) ? derefValue : nullptr;
|
|
}
|
|
|
|
|
|
// Assignments;
|
|
// * Is this LHS in assignment
|
|
// * Passing address in RHS to pointer variable
|
|
{
|
|
const Token *tok = derefValue ? derefValue : valueExpr;
|
|
if (Token::simpleMatch(tok->astParent(), "=")) {
|
|
if (astIsLhs(tok))
|
|
return nullptr;
|
|
if (alloc != NO_ALLOC && astIsRhs(valueExpr))
|
|
return nullptr;
|
|
}
|
|
}
|
|
|
|
// Initialize reference variable
|
|
if (Token::Match((derefValue ? derefValue : vartok)->astParent(), "(|=") && astIsRhs(derefValue ? derefValue : vartok)) {
|
|
const Token *rhstok = derefValue ? derefValue : vartok;
|
|
const Token *lhstok = rhstok->astParent()->astOperand1();
|
|
const Variable *lhsvar = lhstok->variable();
|
|
if (lhsvar && lhsvar->isReference() && lhsvar->nameToken() == lhstok)
|
|
return nullptr;
|
|
}
|
|
|
|
// Stream read/write
|
|
// FIXME this code is a hack!!
|
|
if (mTokenizer->isCPP() && Token::Match(valueExpr->astParent(), "<<|>>")) {
|
|
if (isLikelyStreamRead(mTokenizer->isCPP(), vartok->previous()))
|
|
return nullptr;
|
|
|
|
if (valueExpr->valueType() && valueExpr->valueType()->type == ValueType::Type::VOID)
|
|
return nullptr;
|
|
|
|
// overloaded << operator to initialize variable?
|
|
if (Token::simpleMatch(valueExpr->astParent(), "<<") && !valueExpr->astParent()->astParent()) {
|
|
if (astIsLhs(valueExpr))
|
|
return nullptr;
|
|
const Token *lhs = valueExpr->astParent()->astOperand1();
|
|
if (Token::simpleMatch(lhs, "<<"))
|
|
return valueExpr;
|
|
if (Token::simpleMatch(lhs->previous(), "std ::"))
|
|
return valueExpr;
|
|
const Variable *var = lhs->variable();
|
|
if (var && (var->typeStartToken()->isStandardType() || var->typeStartToken()->isEnumType() || Token::simpleMatch(var->typeStartToken(), "std ::")))
|
|
return valueExpr;
|
|
return nullptr;
|
|
}
|
|
}
|
|
if (mTokenizer->isCPP() && Token::simpleMatch(valueExpr->astParent(), "&") && !valueExpr->astParent()->astParent() && astIsRhs(valueExpr) && Token::Match(valueExpr->astSibling(), "%type%"))
|
|
return nullptr;
|
|
|
|
return derefValue ? derefValue : valueExpr;
|
|
}
|
|
|
|
/***
|
|
* Is function parameter "used" so a "usage of uninitialized variable" can
|
|
* be written? If parameter is passed "by value" then it is "used". If it
|
|
* is passed "by reference" then it is not necessarily "used".
|
|
* @return -1 => unknown 0 => not used 1 => used
|
|
*/
|
|
int CheckUninitVar::isFunctionParUsage(const Token *vartok, bool pointer, Alloc alloc, int indirect) const
|
|
{
|
|
bool unknown = false;
|
|
const Token *parent = getAstParentSkipPossibleCastAndAddressOf(vartok, &unknown);
|
|
if (unknown || !Token::Match(parent, "[(,]"))
|
|
return -1;
|
|
|
|
// locate start parentheses in function call..
|
|
int argumentNumber = 0;
|
|
const Token *start = vartok;
|
|
while (start && !Token::Match(start, "[;{}(]")) {
|
|
if (start->str() == ")")
|
|
start = start->link();
|
|
else if (start->str() == ",")
|
|
++argumentNumber;
|
|
start = start->previous();
|
|
}
|
|
if (!start)
|
|
return -1;
|
|
|
|
if (Token::simpleMatch(start->link(), ") {") && Token::Match(start->previous(), "if|for|while|switch"))
|
|
return (!pointer || alloc == NO_ALLOC);
|
|
|
|
// is this a function call?
|
|
if (Token::Match(start->previous(), "%name% (")) {
|
|
const bool address(vartok->previous()->str() == "&");
|
|
const bool array(vartok->variable() && vartok->variable()->isArray());
|
|
// check how function handle uninitialized data arguments..
|
|
const Function *func = start->previous()->function();
|
|
if (func) {
|
|
const Variable *arg = func->getArgumentVar(argumentNumber);
|
|
if (arg) {
|
|
const Token *argStart = arg->typeStartToken();
|
|
if (!address && !array && Token::Match(argStart, "%type% %name%| [,)]"))
|
|
return 1;
|
|
if (pointer && !address && alloc == NO_ALLOC && Token::Match(argStart, "%type% * %name% [,)]"))
|
|
return 1;
|
|
while (argStart->previous() && argStart->previous()->isName())
|
|
argStart = argStart->previous();
|
|
if (Token::Match(argStart, "const %type% & %name% [,)]")) {
|
|
// If it's a record it's ok to pass a partially uninitialized struct.
|
|
if (vartok->variable() && vartok->variable()->valueType() && vartok->variable()->valueType()->type == ValueType::Type::RECORD)
|
|
return -1;
|
|
return 1;
|
|
}
|
|
if ((pointer || address) && alloc == NO_ALLOC && Token::Match(argStart, "const struct| %type% * %name% [,)]"))
|
|
return 1;
|
|
if ((pointer || address) && Token::Match(argStart, "const %type% %name% [") && Token::Match(argStart->linkAt(3), "] [,)]"))
|
|
return 1;
|
|
}
|
|
|
|
} else if (Token::Match(start->previous(), "if|while|for")) {
|
|
// control-flow statement reading the variable "by value"
|
|
return alloc == NO_ALLOC;
|
|
} else {
|
|
const bool isnullbad = mSettings->library.isnullargbad(start->previous(), argumentNumber + 1);
|
|
if (indirect == 0 && pointer && !address && isnullbad && alloc == NO_ALLOC)
|
|
return 1;
|
|
bool hasIndirect = false;
|
|
const bool isuninitbad = mSettings->library.isuninitargbad(start->previous(), argumentNumber + 1, indirect, &hasIndirect);
|
|
if (alloc != NO_ALLOC)
|
|
return (isnullbad || hasIndirect) && isuninitbad;
|
|
return isuninitbad && (!address || isnullbad);
|
|
}
|
|
}
|
|
|
|
// unknown
|
|
return -1;
|
|
}
|
|
|
|
bool CheckUninitVar::isMemberVariableAssignment(const Token *tok, const std::string &membervar) const
|
|
{
|
|
if (Token::Match(tok, "%name% . %name%") && tok->strAt(2) == membervar) {
|
|
if (Token::Match(tok->tokAt(3), "[=.[]"))
|
|
return true;
|
|
else if (Token::Match(tok->tokAt(-2), "[(,=] &"))
|
|
return true;
|
|
else if (isLikelyStreamRead(mTokenizer->isCPP(), tok->previous()))
|
|
return true;
|
|
else if ((tok->previous() && tok->previous()->isConstOp()) || Token::Match(tok->previous(), "[|="))
|
|
; // member variable usage
|
|
else if (tok->tokAt(3)->isConstOp())
|
|
; // member variable usage
|
|
else if (Token::Match(tok->previous(), "[(,] %name% . %name% [,)]") &&
|
|
1 == isFunctionParUsage(tok, false, NO_ALLOC)) {
|
|
return false;
|
|
} else
|
|
return true;
|
|
} else if (tok->strAt(1) == "=")
|
|
return true;
|
|
else if (Token::Match(tok, "%var% . %name% (")) {
|
|
const Token *ftok = tok->tokAt(2);
|
|
if (!ftok->function() || !ftok->function()->isConst())
|
|
// TODO: Try to determine if membervar is assigned in method
|
|
return true;
|
|
} else if (tok->strAt(-1) == "&") {
|
|
if (Token::Match(tok->tokAt(-2), "[(,] & %name%")) {
|
|
// locate start parentheses in function call..
|
|
int argumentNumber = 0;
|
|
const Token *ftok = tok;
|
|
while (ftok && !Token::Match(ftok, "[;{}(]")) {
|
|
if (ftok->str() == ")")
|
|
ftok = ftok->link();
|
|
else if (ftok->str() == ",")
|
|
++argumentNumber;
|
|
ftok = ftok->previous();
|
|
}
|
|
|
|
// is this a function call?
|
|
ftok = ftok ? ftok->previous() : nullptr;
|
|
if (Token::Match(ftok, "%name% (")) {
|
|
// check how function handle uninitialized data arguments..
|
|
const Function *function = ftok->function();
|
|
|
|
if (!function && mSettings) {
|
|
// Function definition not seen, check if direction is specified in the library configuration
|
|
const Library::ArgumentChecks::Direction argDirection = mSettings->library.getArgDirection(ftok, 1 + argumentNumber);
|
|
if (argDirection == Library::ArgumentChecks::Direction::DIR_IN)
|
|
return false;
|
|
else if (argDirection == Library::ArgumentChecks::Direction::DIR_OUT)
|
|
return true;
|
|
}
|
|
|
|
const Variable *arg = function ? function->getArgumentVar(argumentNumber) : nullptr;
|
|
const Token *argStart = arg ? arg->typeStartToken() : nullptr;
|
|
while (argStart && argStart->previous() && argStart->previous()->isName())
|
|
argStart = argStart->previous();
|
|
if (Token::Match(argStart, "const struct| %type% * const| %name% [,)]"))
|
|
return false;
|
|
}
|
|
|
|
else if (ftok && Token::simpleMatch(ftok->previous(), "= * ("))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool CheckUninitVar::isMemberVariableUsage(const Token *tok, bool isPointer, Alloc alloc, const std::string &membervar) const
|
|
{
|
|
if (Token::Match(tok->previous(), "[(,] %name% . %name% [,)]") &&
|
|
tok->strAt(2) == membervar) {
|
|
const int use = isFunctionParUsage(tok, isPointer, alloc);
|
|
if (use == 1)
|
|
return true;
|
|
}
|
|
|
|
if (isMemberVariableAssignment(tok, membervar))
|
|
return false;
|
|
|
|
if (Token::Match(tok, "%name% . %name%") && tok->strAt(2) == membervar && !(tok->tokAt(-2)->variable() && tok->tokAt(-2)->variable()->isReference())) {
|
|
const Token *parent = tok->next()->astParent();
|
|
if (parent && parent->isUnaryOp("&"))
|
|
return false;
|
|
return true;
|
|
} else if (!isPointer && Token::Match(tok->previous(), "[(,] %name% [,)]") && isVariableUsage(tok, isPointer, alloc))
|
|
return true;
|
|
|
|
else if (!isPointer && Token::Match(tok->previous(), "= %name% ;"))
|
|
return true;
|
|
|
|
// = *(&var);
|
|
else if (!isPointer &&
|
|
Token::simpleMatch(tok->astParent(),"&") &&
|
|
Token::simpleMatch(tok->astParent()->astParent(),"*") &&
|
|
Token::Match(tok->astParent()->astParent()->astParent(), "= * (| &") &&
|
|
tok->astParent()->astParent()->astParent()->astOperand2() == tok->astParent()->astParent())
|
|
return true;
|
|
|
|
else if (mSettings->certainty.isEnabled(Certainty::experimental) &&
|
|
!isPointer &&
|
|
Token::Match(tok->tokAt(-2), "[(,] & %name% [,)]") &&
|
|
isVariableUsage(tok, isPointer, alloc))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
void CheckUninitVar::uninitstringError(const Token *tok, const std::string &varname, bool strncpy_)
|
|
{
|
|
reportError(tok, Severity::error, "uninitstring", "$symbol:" + varname + "\nDangerous usage of '$symbol'" + (strncpy_ ? " (strncpy doesn't always null-terminate it)." : " (not null-terminated)."), CWE_USE_OF_POTENTIALLY_DANGEROUS_FUNCTION, Certainty::normal);
|
|
}
|
|
|
|
void CheckUninitVar::uninitdataError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "uninitdata", "$symbol:" + varname + "\nMemory is allocated but not initialized: $symbol", CWE_USE_OF_UNINITIALIZED_VARIABLE, Certainty::normal);
|
|
}
|
|
|
|
void CheckUninitVar::uninitvarError(const Token *tok, const std::string &varname, ErrorPath errorPath)
|
|
{
|
|
errorPath.emplace_back(tok, "");
|
|
reportError(errorPath, Severity::error, "uninitvar", "$symbol:" + varname + "\nUninitialized variable: $symbol", CWE_USE_OF_UNINITIALIZED_VARIABLE, Certainty::normal);
|
|
}
|
|
|
|
void CheckUninitVar::uninitStructMemberError(const Token *tok, const std::string &membername)
|
|
{
|
|
reportError(tok,
|
|
Severity::error,
|
|
"uninitStructMember",
|
|
"$symbol:" + membername + "\nUninitialized struct member: $symbol", CWE_USE_OF_UNINITIALIZED_VARIABLE, Certainty::normal);
|
|
}
|
|
|
|
static bool isLeafDot(const Token* tok)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
const Token * parent = tok->astParent();
|
|
if (!Token::simpleMatch(parent, "."))
|
|
return false;
|
|
if (parent->astOperand2() == tok)
|
|
return true;
|
|
return isLeafDot(parent);
|
|
}
|
|
|
|
void CheckUninitVar::valueFlowUninit()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
// check every executable scope
|
|
for (const Scope &scope : symbolDatabase->scopeList) {
|
|
if (!scope.isExecutable())
|
|
continue;
|
|
for (const Token* tok = scope.bodyStart; tok != scope.bodyEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "sizeof|typeof|offsetof|decltype (")) {
|
|
tok = tok->linkAt(1);
|
|
continue;
|
|
}
|
|
if (!tok->variable() && !tok->isUnaryOp("*"))
|
|
continue;
|
|
auto v = std::find_if(tok->values().begin(), tok->values().end(), std::mem_fn(&ValueFlow::Value::isUninitValue));
|
|
if (v == tok->values().end())
|
|
continue;
|
|
if (v->isInconclusive())
|
|
continue;
|
|
if (v->indirect > 1 || v->indirect < 0)
|
|
continue;
|
|
bool uninitderef = false;
|
|
if (tok->variable()) {
|
|
if (!isVariableUsage(tok, tok->variable()->isPointer(), tok->variable()->isArray() ? ARRAY : NO_ALLOC, v->indirect))
|
|
continue;
|
|
bool unknown;
|
|
const bool deref = CheckNullPointer::isPointerDeRef(tok, unknown, mSettings);
|
|
if (v->indirect == 1 && !deref)
|
|
continue;
|
|
uninitderef = deref && v->indirect == 0;
|
|
const bool isleaf = isLeafDot(tok) || uninitderef;
|
|
if (Token::Match(tok->astParent(), ". %var%") && !isleaf)
|
|
continue;
|
|
}
|
|
if (!Token::Match(tok->astParent(), ". %name% (") && !uninitderef && isVariableChanged(tok, v->indirect, mSettings, mTokenizer->isCPP()))
|
|
continue;
|
|
uninitvarError(tok, tok->expressionString(), v->errorPath);
|
|
const Token * nextTok = tok;
|
|
while (Token::simpleMatch(nextTok->astParent(), "."))
|
|
nextTok = nextTok->astParent();
|
|
nextTok = nextAfterAstRightmostLeaf(nextTok);
|
|
if (nextTok == scope.bodyEnd)
|
|
break;
|
|
tok = nextTok ? nextTok : tok;
|
|
}
|
|
}
|
|
}
|
|
|
|
std::string CheckUninitVar::MyFileInfo::toString() const
|
|
{
|
|
return CTU::toString(unsafeUsage);
|
|
}
|
|
|
|
Check::FileInfo *CheckUninitVar::getFileInfo(const Tokenizer *tokenizer, const Settings *settings) const
|
|
{
|
|
const CheckUninitVar checker(tokenizer, settings, nullptr);
|
|
return checker.getFileInfo();
|
|
}
|
|
|
|
static bool isVariableUsage(const Check *check, const Token *vartok, MathLib::bigint *value)
|
|
{
|
|
(void)value;
|
|
const CheckUninitVar *c = dynamic_cast<const CheckUninitVar *>(check);
|
|
return c && c->isVariableUsage(vartok, true, CheckUninitVar::Alloc::ARRAY);
|
|
}
|
|
|
|
Check::FileInfo *CheckUninitVar::getFileInfo() const
|
|
{
|
|
const std::list<CTU::FileInfo::UnsafeUsage> &unsafeUsage = CTU::getUnsafeUsage(mTokenizer, mSettings, this, ::isVariableUsage);
|
|
if (unsafeUsage.empty())
|
|
return nullptr;
|
|
|
|
MyFileInfo *fileInfo = new MyFileInfo;
|
|
fileInfo->unsafeUsage = unsafeUsage;
|
|
return fileInfo;
|
|
}
|
|
|
|
Check::FileInfo * CheckUninitVar::loadFileInfoFromXml(const tinyxml2::XMLElement *xmlElement) const
|
|
{
|
|
const std::list<CTU::FileInfo::UnsafeUsage> &unsafeUsage = CTU::loadUnsafeUsageListFromXml(xmlElement);
|
|
if (unsafeUsage.empty())
|
|
return nullptr;
|
|
|
|
MyFileInfo *fileInfo = new MyFileInfo;
|
|
fileInfo->unsafeUsage = unsafeUsage;
|
|
return fileInfo;
|
|
}
|
|
|
|
bool CheckUninitVar::analyseWholeProgram(const CTU::FileInfo *ctu, const std::list<Check::FileInfo*> &fileInfo, const Settings& settings, ErrorLogger &errorLogger)
|
|
{
|
|
if (!ctu)
|
|
return false;
|
|
bool foundErrors = false;
|
|
(void)settings; // This argument is unused
|
|
|
|
const std::map<std::string, std::list<const CTU::FileInfo::CallBase *>> callsMap = ctu->getCallsMap();
|
|
|
|
for (Check::FileInfo *fi1 : fileInfo) {
|
|
const MyFileInfo *fi = dynamic_cast<MyFileInfo*>(fi1);
|
|
if (!fi)
|
|
continue;
|
|
for (const CTU::FileInfo::UnsafeUsage &unsafeUsage : fi->unsafeUsage) {
|
|
const CTU::FileInfo::FunctionCall *functionCall = nullptr;
|
|
|
|
const std::list<ErrorMessage::FileLocation> &locationList =
|
|
CTU::FileInfo::getErrorPath(CTU::FileInfo::InvalidValueType::uninit,
|
|
unsafeUsage,
|
|
callsMap,
|
|
"Using argument ARG",
|
|
&functionCall,
|
|
false);
|
|
if (locationList.empty())
|
|
continue;
|
|
|
|
const ErrorMessage errmsg(locationList,
|
|
emptyString,
|
|
Severity::error,
|
|
"Using argument " + unsafeUsage.myArgumentName + " that points at uninitialized variable " + functionCall->callArgumentExpression,
|
|
"ctuuninitvar",
|
|
CWE_USE_OF_UNINITIALIZED_VARIABLE,
|
|
Certainty::normal);
|
|
errorLogger.reportErr(errmsg);
|
|
|
|
foundErrors = true;
|
|
}
|
|
}
|
|
return foundErrors;
|
|
}
|