701 lines
27 KiB
C++
701 lines
27 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2019 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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// Auto variables checks
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//---------------------------------------------------------------------------
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#include "checkautovariables.h"
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#include "astutils.h"
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#include "errorlogger.h"
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#include "library.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 <cstddef>
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#include <list>
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#include <functional>
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//---------------------------------------------------------------------------
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// Register this check class into cppcheck by creating a static instance of it..
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namespace {
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CheckAutoVariables instance;
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}
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static const CWE CWE398(398U); // Indicator of Poor Code Quality
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static const CWE CWE562(562U); // Return of Stack Variable Address
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static const CWE CWE590(590U); // Free of Memory not on the Heap
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static bool isPtrArg(const Token *tok)
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{
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const Variable *var = tok->variable();
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return (var && var->isArgument() && var->isPointer());
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}
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static bool isArrayArg(const Token *tok)
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{
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const Variable *var = tok->variable();
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return (var && var->isArgument() && var->isArray());
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}
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static bool isArrayVar(const Token *tok)
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{
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const Variable *var = tok->variable();
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return (var && var->isArray());
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}
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static bool isRefPtrArg(const Token *tok)
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{
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const Variable *var = tok->variable();
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return (var && var->isArgument() && var->isReference() && var->isPointer());
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}
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static bool isNonReferenceArg(const Token *tok)
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{
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const Variable *var = tok->variable();
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return (var && var->isArgument() && !var->isReference() && (var->isPointer() || var->valueType()->type >= ValueType::Type::CONTAINER || var->type()));
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}
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static bool isAutoVar(const Token *tok)
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{
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const Variable *var = tok->variable();
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if (!var || !var->isLocal() || var->isStatic())
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return false;
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if (var->isReference()) {
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// address of reference variable can be taken if the address
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// of the variable it points at is not a auto-var
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// TODO: check what the reference variable references.
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return false;
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}
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if (Token::Match(tok, "%name% .|::")) {
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do {
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tok = tok->tokAt(2);
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} while (Token::Match(tok, "%name% .|::"));
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if (Token::Match(tok, "%name% ("))
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return false;
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}
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return true;
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}
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static bool isAutoVarArray(const Token *tok)
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{
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if (!tok)
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return false;
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// &x[..]
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if (tok->isUnaryOp("&") && Token::simpleMatch(tok->astOperand1(), "["))
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return isAutoVarArray(tok->astOperand1()->astOperand1());
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// x+y
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if (tok->str() == "+")
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return isAutoVarArray(tok->astOperand1()) || isAutoVarArray(tok->astOperand2());
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// x-intexpr
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if (tok->str() == "-")
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return isAutoVarArray(tok->astOperand1()) &&
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tok->astOperand2() &&
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tok->astOperand2()->valueType() &&
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tok->astOperand2()->valueType()->isIntegral();
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const Variable *var = tok->variable();
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if (!var)
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return false;
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// Variable
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if (var->isLocal() && !var->isStatic() && var->isArray() && !var->isPointer())
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return true;
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// ValueFlow
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if (var->isPointer() && !var->isArgument()) {
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for (std::list<ValueFlow::Value>::const_iterator it = tok->values().begin(); it != tok->values().end(); ++it) {
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const ValueFlow::Value &val = *it;
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if (val.isTokValue() && isAutoVarArray(val.tokvalue))
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return true;
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}
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}
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return false;
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}
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// Verification that we really take the address of a local variable
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static bool checkRvalueExpression(const Token * const vartok)
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{
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const Variable * const var = vartok->variable();
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if (var == nullptr)
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return false;
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if (Token::Match(vartok->previous(), "& %name% [") && var->isPointer())
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return false;
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const Token * const next = vartok->next();
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// &a.b[0]
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if (Token::Match(vartok, "%name% . %var% [") && !var->isPointer()) {
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const Variable *var2 = next->next()->variable();
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return var2 && !var2->isPointer();
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}
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return ((next->str() != "." || (!var->isPointer() && (!var->isClass() || var->type()))) && next->strAt(2) != ".");
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}
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static bool isAddressOfLocalVariable(const Token *expr)
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{
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if (!expr)
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return false;
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if (Token::Match(expr, "+|-"))
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return isAddressOfLocalVariable(expr->astOperand1()) || isAddressOfLocalVariable(expr->astOperand2());
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if (expr->isCast())
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return isAddressOfLocalVariable(expr->astOperand2() ? expr->astOperand2() : expr->astOperand1());
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if (expr->isUnaryOp("&")) {
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const Token *op = expr->astOperand1();
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bool deref = false;
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while (Token::Match(op, ".|[")) {
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if (op->originalName() == "->")
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return false;
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if (op->str() == "[")
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deref = true;
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op = op->astOperand1();
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}
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return op && isAutoVar(op) && (!deref || !op->variable()->isPointer());
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}
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return false;
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}
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static bool variableIsUsedInScope(const Token* start, nonneg int varId, const Scope *scope)
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{
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if (!start) // Ticket #5024
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return false;
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for (const Token *tok = start; tok && tok != scope->bodyEnd; tok = tok->next()) {
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if (tok->varId() == varId)
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return true;
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const Scope::ScopeType scopeType = tok->scope()->type;
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if (scopeType == Scope::eFor || scopeType == Scope::eDo || scopeType == Scope::eWhile) // In case of loops, better checking would be necessary
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return true;
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if (Token::simpleMatch(tok, "asm ("))
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return true;
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}
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return false;
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}
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void CheckAutoVariables::assignFunctionArg()
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{
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const bool printStyle = mSettings->isEnabled(Settings::STYLE);
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const bool printWarning = mSettings->isEnabled(Settings::WARNING);
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if (!printStyle && !printWarning)
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return;
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope * scope : symbolDatabase->functionScopes) {
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for (const Token *tok = scope->bodyStart; tok && tok != scope->bodyEnd; tok = tok->next()) {
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// TODO: What happens if this is removed?
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if (tok->astParent())
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continue;
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if (!(tok->isAssignmentOp() || Token::Match(tok, "++|--")) || !Token::Match(tok->astOperand1(), "%var%"))
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continue;
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const Token* const vartok = tok->astOperand1();
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if (isNonReferenceArg(vartok) &&
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!Token::Match(vartok->next(), "= %varid% ;", vartok->varId()) &&
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!variableIsUsedInScope(Token::findsimplematch(vartok->next(), ";"), vartok->varId(), scope) &&
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!Token::findsimplematch(vartok, "goto", scope->bodyEnd)) {
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if (vartok->variable()->isPointer() && printWarning)
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errorUselessAssignmentPtrArg(vartok);
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else if (printStyle)
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errorUselessAssignmentArg(vartok);
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}
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}
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}
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}
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void CheckAutoVariables::autoVariables()
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{
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const bool printInconclusive = mSettings->inconclusive;
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope * scope : symbolDatabase->functionScopes) {
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for (const Token *tok = scope->bodyStart; tok && tok != scope->bodyEnd; tok = tok->next()) {
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// Skip lambda..
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if (const Token *lambdaEndToken = findLambdaEndToken(tok)) {
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tok = lambdaEndToken;
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continue;
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}
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// Critical assignment
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if (Token::Match(tok, "[;{}] %var% = & %var%") && isRefPtrArg(tok->next()) && isAutoVar(tok->tokAt(4))) {
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if (checkRvalueExpression(tok->tokAt(4)))
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errorAutoVariableAssignment(tok->next(), false);
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} else if (Token::Match(tok, "[;{}] * %var% =") && isPtrArg(tok->tokAt(2)) && isAddressOfLocalVariable(tok->tokAt(3)->astOperand2())) {
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errorAutoVariableAssignment(tok->next(), false);
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} else if (Token::Match(tok, "[;{}] %var% . %var% =") && isPtrArg(tok->next()) && isAddressOfLocalVariable(tok->tokAt(4)->astOperand2())) {
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errorAutoVariableAssignment(tok->next(), false);
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} else if (Token::Match(tok, "[;{}] %var% . %var% = %var% ;")) {
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// TODO: check if the parameter is only changed temporarily (#2969)
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if (printInconclusive && isPtrArg(tok->next())) {
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if (isAutoVarArray(tok->tokAt(5)))
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errorAutoVariableAssignment(tok->next(), true);
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}
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tok = tok->tokAt(5);
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} else if (Token::Match(tok, "[;{}] * %var% = %var% ;")) {
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const Variable * var1 = tok->tokAt(2)->variable();
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if (var1 && var1->isArgument() && Token::Match(var1->nameToken()->tokAt(-3), "%type% * *")) {
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if (isAutoVarArray(tok->tokAt(4)))
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errorAutoVariableAssignment(tok->next(), false);
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}
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tok = tok->tokAt(4);
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} else if (Token::Match(tok, "[;{}] %var% [") && Token::simpleMatch(tok->linkAt(2), "] =") &&
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(isPtrArg(tok->next()) || isArrayArg(tok->next())) && isAddressOfLocalVariable(tok->linkAt(2)->next()->astOperand2())) {
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errorAutoVariableAssignment(tok->next(), false);
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}
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// Invalid pointer deallocation
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else if ((Token::Match(tok, "%name% ( %var% ) ;") && mSettings->library.getDeallocFuncInfo(tok)) ||
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(mTokenizer->isCPP() && Token::Match(tok, "delete [| ]| (| %var% !!["))) {
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tok = Token::findmatch(tok->next(), "%var%");
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if (isArrayVar(tok))
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errorInvalidDeallocation(tok, nullptr);
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else if (tok && tok->variable() && tok->variable()->isPointer()) {
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for (const ValueFlow::Value &v : tok->values()) {
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if (v.isTokValue() && isArrayVar(v.tokvalue)) {
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errorInvalidDeallocation(tok, &v);
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break;
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}
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}
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}
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} else if ((Token::Match(tok, "%name% ( & %var% ) ;") && mSettings->library.getDeallocFuncInfo(tok)) ||
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(mTokenizer->isCPP() && Token::Match(tok, "delete [| ]| (| & %var% !!["))) {
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tok = Token::findmatch(tok->next(), "%var%");
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if (isAutoVar(tok))
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errorInvalidDeallocation(tok, nullptr);
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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 CheckAutoVariables::errorReturnAddressToAutoVariable(const Token *tok)
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{
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reportError(tok, Severity::error, "returnAddressOfAutoVariable", "Address of an auto-variable returned.", CWE562, false);
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}
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void CheckAutoVariables::errorReturnAddressToAutoVariable(const Token *tok, const ValueFlow::Value *value)
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{
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reportError(tok, Severity::error, "returnAddressOfAutoVariable", "Address of auto-variable '" + value->tokvalue->astOperand1()->expressionString() + "' returned", CWE562, false);
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}
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void CheckAutoVariables::errorReturnPointerToLocalArray(const Token *tok)
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{
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reportError(tok, Severity::error, "returnLocalVariable", "Pointer to local array variable returned.", CWE562, false);
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}
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void CheckAutoVariables::errorAutoVariableAssignment(const Token *tok, bool inconclusive)
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{
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if (!inconclusive) {
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reportError(tok, Severity::error, "autoVariables",
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"Address of local auto-variable assigned to a function parameter.\n"
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"Dangerous assignment - the function parameter is assigned the address of a local "
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"auto-variable. Local auto-variables are reserved from the stack which "
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"is freed when the function ends. So the pointer to a local variable "
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"is invalid after the function ends.", CWE562, false);
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} else {
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reportError(tok, Severity::error, "autoVariables",
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"Address of local auto-variable assigned to a function parameter.\n"
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"Function parameter is assigned the address of a local auto-variable. "
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"Local auto-variables are reserved from the stack which is freed when "
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"the function ends. The address is invalid after the function ends and it "
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"might 'leak' from the function through the parameter.",
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CWE562,
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true);
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}
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}
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void CheckAutoVariables::errorReturnAddressOfFunctionParameter(const Token *tok, const std::string &varname)
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{
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reportError(tok, Severity::error, "returnAddressOfFunctionParameter",
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"$symbol:" + varname + "\n"
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"Address of function parameter '$symbol' returned.\n"
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"Address of the function parameter '$symbol' becomes invalid after the function exits because "
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"function parameters are stored on the stack which is freed when the function exits. Thus the returned "
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"value is invalid.", CWE562, false);
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}
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void CheckAutoVariables::errorUselessAssignmentArg(const Token *tok)
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{
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reportError(tok,
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Severity::style,
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"uselessAssignmentArg",
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"Assignment of function parameter has no effect outside the function.", CWE398, false);
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}
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void CheckAutoVariables::errorUselessAssignmentPtrArg(const Token *tok)
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{
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reportError(tok,
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Severity::warning,
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"uselessAssignmentPtrArg",
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"Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?", CWE398, false);
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}
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//---------------------------------------------------------------------------
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// return temporary?
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bool CheckAutoVariables::returnTemporary(const Token *tok)
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{
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bool func = false; // Might it be a function call?
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bool retref = false; // is there such a function that returns a reference?
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bool retvalue = false; // is there such a function that returns a value?
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const Function *function = tok->function();
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if (function) {
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// Ticket #5478: Only functions or operator equal might return a temporary
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if (function->type != Function::eOperatorEqual && function->type != Function::eFunction)
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return false;
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retref = function->tokenDef->strAt(-1) == "&";
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if (!retref) {
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const Token *start = function->retDef;
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if (start->str() == "const")
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start = start->next();
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if (start->str() == "::")
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start = start->next();
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if (Token::simpleMatch(start, "std ::")) {
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if (start->strAt(3) != "<" || !Token::simpleMatch(start->linkAt(3), "> ::"))
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retvalue = true;
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else
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retref = true; // Assume that a reference is returned
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} else {
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if (start->type())
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retvalue = true;
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else
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retref = true;
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}
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}
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func = true;
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}
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if (!func && tok->type())
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return true;
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return (!retref && retvalue);
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}
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//---------------------------------------------------------------------------
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static bool astHasAutoResult(const Token *tok)
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{
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if (tok->astOperand1() && !astHasAutoResult(tok->astOperand1()))
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return false;
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if (tok->astOperand2() && !astHasAutoResult(tok->astOperand2()))
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return false;
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if (tok->isOp()) {
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if (tok->tokType() == Token::eIncDecOp)
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return false;
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if ((tok->str() == "<<" || tok->str() == ">>") && tok->astOperand1()) {
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const Token* tok2 = tok->astOperand1();
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while (tok2 && tok2->isUnaryOp("*"))
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tok2 = tok2->astOperand1();
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return tok2 && tok2->variable() && !tok2->variable()->isClass() && !tok2->variable()->isStlType(); // Class or unknown type on LHS: Assume it is a stream
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}
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return true;
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}
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if (tok->isLiteral())
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return true;
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if (tok->isName()) {
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// TODO: check function calls, struct members, arrays, etc also
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if (!tok->variable())
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return false;
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if (tok->variable()->isStlType())
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return true;
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if (tok->variable()->isClass() || tok->variable()->isPointer() || tok->variable()->isReference()) // TODO: Properly handle pointers/references to classes in symbol database
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return false;
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return true;
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}
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return false;
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}
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void CheckAutoVariables::returnReference()
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{
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if (mTokenizer->isC())
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return;
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const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
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for (const Scope * scope : symbolDatabase->functionScopes) {
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if (!scope->function)
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continue;
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const Token *tok = scope->function->tokenDef;
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// have we reached a function that returns a reference?
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if (tok->previous() && tok->previous()->str() == "&") {
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for (const Token *tok2 = scope->bodyStart->next(); tok2 && tok2 != scope->bodyEnd; tok2 = tok2->next()) {
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if (!tok2->scope()->isExecutable()) {
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tok2 = tok2->scope()->bodyEnd;
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if (!tok2)
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break;
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continue;
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}
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// Skip over lambdas
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const Token *lambdaEndToken = findLambdaEndToken(tok2);
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if (lambdaEndToken)
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tok2 = lambdaEndToken->next();
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if (tok2->str() == "(")
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tok2 = tok2->link();
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if (tok2->str() != "return")
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continue;
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// return reference to temporary..
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if (Token::Match(tok2, "return %name% (") && Token::simpleMatch(tok2->linkAt(2), ") ;")) {
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if (returnTemporary(tok2->next())) {
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// report error..
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errorReturnTempReference(tok2);
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}
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}
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// Return reference to a literal or the result of a calculation
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else if (tok2->astOperand1() && (tok2->astOperand1()->isCalculation() || tok2->next()->isLiteral()) &&
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astHasAutoResult(tok2->astOperand1())) {
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errorReturnTempReference(tok2);
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}
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}
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}
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}
|
|
}
|
|
|
|
static bool isInScope(const Token * tok, const Scope * scope)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (!scope)
|
|
return false;
|
|
const Variable * var = tok->variable();
|
|
if (var && (var->isGlobal() || var->isStatic() || var->isExtern()))
|
|
return false;
|
|
if (tok->scope() && tok->scope()->isNestedIn(scope))
|
|
return true;
|
|
if (!var)
|
|
return false;
|
|
if (var->isArgument() && !var->isReference()) {
|
|
const Scope * tokScope = tok->scope();
|
|
if (!tokScope)
|
|
return false;
|
|
for (const Scope * argScope:tokScope->nestedList) {
|
|
if (argScope && argScope->isNestedIn(scope))
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool isDeadScope(const Token * tok, const Scope * scope)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (!scope)
|
|
return false;
|
|
const Variable * var = tok->variable();
|
|
if (var && (!var->isLocal() || var->isStatic() || var->isExtern()))
|
|
return false;
|
|
if (tok->scope() && tok->scope()->bodyEnd != scope->bodyEnd && precedes(tok->scope()->bodyEnd, scope->bodyEnd))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static int getPointerDepth(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return 0;
|
|
return tok->valueType() ? tok->valueType()->pointer : 0;
|
|
}
|
|
|
|
void CheckAutoVariables::checkVarLifetimeScope(const Token * start, const Token * end)
|
|
{
|
|
if (!start)
|
|
return;
|
|
const Scope * scope = start->scope();
|
|
if (!scope)
|
|
return;
|
|
// If the scope is not set correctly then skip checking it
|
|
if (scope->bodyStart != start)
|
|
return;
|
|
bool returnRef = Function::returnsReference(scope->function);
|
|
for (const Token *tok = start; tok && tok != end; tok = tok->next()) {
|
|
// Return reference from function
|
|
if (returnRef && Token::simpleMatch(tok->astParent(), "return")) {
|
|
ErrorPath errorPath;
|
|
const Variable *var = getLifetimeVariable(tok, errorPath);
|
|
if (var && !var->isGlobal() && !var->isStatic() && !var->isReference() && !var->isRValueReference() &&
|
|
isInScope(var->nameToken(), tok->scope())) {
|
|
errorReturnReference(tok, errorPath);
|
|
continue;
|
|
}
|
|
// Assign reference to non-local variable
|
|
} else if (Token::Match(tok->previous(), "&|&& %var% =") && tok->astParent() == tok->next() &&
|
|
tok->variable() && tok->variable()->nameToken() == tok &&
|
|
tok->variable()->declarationId() == tok->varId() && tok->variable()->isStatic() &&
|
|
!tok->variable()->isArgument()) {
|
|
ErrorPath errorPath;
|
|
const Variable *var = getLifetimeVariable(tok, errorPath);
|
|
if (var && isInScope(var->nameToken(), tok->scope())) {
|
|
errorDanglingReference(tok, var, errorPath);
|
|
continue;
|
|
}
|
|
}
|
|
for (const ValueFlow::Value& val:tok->values()) {
|
|
if (!val.isLocalLifetimeValue())
|
|
continue;
|
|
if (!val.tokvalue->variable())
|
|
continue;
|
|
if (Token::Match(tok->astParent(), "return|throw")) {
|
|
if (getPointerDepth(tok) < getPointerDepth(val.tokvalue))
|
|
continue;
|
|
if (!isLifetimeBorrowed(tok, mSettings))
|
|
continue;
|
|
if (isInScope(val.tokvalue->variable()->nameToken(), scope)) {
|
|
errorReturnDanglingLifetime(tok, &val);
|
|
break;
|
|
}
|
|
} else if (isDeadScope(val.tokvalue->variable()->nameToken(), tok->scope())) {
|
|
errorInvalidLifetime(tok, &val);
|
|
break;
|
|
} else if (isInScope(val.tokvalue->variable()->nameToken(), tok->scope())) {
|
|
const Variable * var = nullptr;
|
|
const Token * tok2 = tok;
|
|
if (Token::simpleMatch(tok->astParent(), "=")) {
|
|
if (tok->astParent()->astOperand2() == tok) {
|
|
var = getLHSVariable(tok->astParent());
|
|
tok2 = tok->astParent()->astOperand1();
|
|
}
|
|
} else if (tok->variable() && tok->variable()->declarationId() == tok->varId()) {
|
|
var = tok->variable();
|
|
}
|
|
if (var && !var->isLocal() && !var->isArgument() && !isVariableChanged(tok->next(), tok->scope()->bodyEnd, var->declarationId(), var->isGlobal(), mSettings, mTokenizer->isCPP())) {
|
|
errorDanglngLifetime(tok2, &val);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
const Token *lambdaEndToken = findLambdaEndToken(tok);
|
|
if (lambdaEndToken) {
|
|
checkVarLifetimeScope(lambdaEndToken->link(), lambdaEndToken);
|
|
tok = lambdaEndToken;
|
|
}
|
|
if (tok->str() == "{" && tok->scope()) {
|
|
// Check functions in local classes
|
|
if (tok->scope()->type == Scope::eClass ||
|
|
tok->scope()->type == Scope::eStruct ||
|
|
tok->scope()->type == Scope::eUnion) {
|
|
for (const Function& f:tok->scope()->functionList) {
|
|
if (f.functionScope)
|
|
checkVarLifetimeScope(f.functionScope->bodyStart, f.functionScope->bodyEnd);
|
|
}
|
|
tok = tok->link();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckAutoVariables::checkVarLifetime()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
if (!scope->function)
|
|
continue;
|
|
checkVarLifetimeScope(scope->bodyStart, scope->bodyEnd);
|
|
}
|
|
}
|
|
|
|
void CheckAutoVariables::errorReturnDanglingLifetime(const Token *tok, const ValueFlow::Value *val)
|
|
{
|
|
ErrorPath errorPath = val ? val->errorPath : ErrorPath();
|
|
std::string msg = "Returning " + lifetimeMessage(tok, val, errorPath);
|
|
errorPath.emplace_back(tok, "");
|
|
reportError(errorPath, Severity::error, "returnDanglingLifetime", msg + " that will be invalid when returning.", CWE562, false);
|
|
}
|
|
|
|
void CheckAutoVariables::errorInvalidLifetime(const Token *tok, const ValueFlow::Value* val)
|
|
{
|
|
ErrorPath errorPath = val ? val->errorPath : ErrorPath();
|
|
std::string msg = "Using " + lifetimeMessage(tok, val, errorPath);
|
|
errorPath.emplace_back(tok, "");
|
|
reportError(errorPath, Severity::error, "invalidLifetime", msg + " that is out of scope.", CWE562, false);
|
|
}
|
|
|
|
void CheckAutoVariables::errorDanglngLifetime(const Token *tok, const ValueFlow::Value *val)
|
|
{
|
|
ErrorPath errorPath = val ? val->errorPath : ErrorPath();
|
|
std::string tokName = tok ? tok->expressionString() : "x";
|
|
std::string msg = "Non-local variable '" + tokName + "' will use " + lifetimeMessage(tok, val, errorPath);
|
|
errorPath.emplace_back(tok, "");
|
|
reportError(errorPath, Severity::error, "danglingLifetime", msg + ".", CWE562, false);
|
|
}
|
|
|
|
void CheckAutoVariables::errorReturnReference(const Token *tok, ErrorPath errorPath)
|
|
{
|
|
errorPath.emplace_back(tok, "");
|
|
reportError(errorPath, Severity::error, "returnReference", "Reference to local variable returned.", CWE562, false);
|
|
}
|
|
|
|
void CheckAutoVariables::errorDanglingReference(const Token *tok, const Variable *var, ErrorPath errorPath)
|
|
{
|
|
std::string tokName = tok ? tok->str() : "x";
|
|
std::string varName = var ? var->name() : "y";
|
|
std::string msg = "Non-local reference variable '" + tokName + "' to local variable '" + varName + "'";
|
|
errorPath.emplace_back(tok, "");
|
|
reportError(errorPath, Severity::error, "danglingReference", msg, CWE562, false);
|
|
}
|
|
|
|
void CheckAutoVariables::errorReturnTempReference(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::error, "returnTempReference", "Reference to temporary returned.", CWE562, false);
|
|
}
|
|
|
|
void CheckAutoVariables::errorInvalidDeallocation(const Token *tok, const ValueFlow::Value *val)
|
|
{
|
|
const Variable *var = val ? val->tokvalue->variable() : (tok ? tok->variable() : nullptr);
|
|
|
|
std::string type = "auto-variable";
|
|
if (var) {
|
|
if (var->isGlobal())
|
|
type = "global variable";
|
|
else if (var->isStatic())
|
|
type = "static variable";
|
|
}
|
|
|
|
if (val)
|
|
type += " (" + val->tokvalue->str() + ")";
|
|
|
|
reportError(getErrorPath(tok, val, "Deallocating memory that was not dynamically allocated"),
|
|
Severity::error,
|
|
"autovarInvalidDeallocation",
|
|
"Deallocation of an " + type + " results in undefined behaviour.\n"
|
|
"The deallocation of an " + type + " results in undefined behaviour. You should only free memory "
|
|
"that has been allocated dynamically.", CWE590, false);
|
|
}
|