cppcheck/lib/checkexceptionsafety.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
2012-01-01 00:05:37 +01:00
* Copyright (C) 2007-2012 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
#include "checkexceptionsafety.h"
#include "symboldatabase.h"
#include "token.h"
//---------------------------------------------------------------------------
// Register CheckExceptionSafety..
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namespace {
CheckExceptionSafety instance;
}
//---------------------------------------------------------------------------
void CheckExceptionSafety::destructors()
{
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
// Perform check..
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
for (std::list<Function>::const_iterator j = i->functionList.begin(); j != i->functionList.end(); ++j) {
// only looking for destructors
if (j->type == Function::eDestructor && j->functionScope) {
// Inspect this destructor..
for (const Token *tok = j->functionScope->classStart->next(); tok != j->functionScope->classEnd; tok = tok->next()) {
// throw found within a destructor
if (tok->str() == "throw") {
destructorsError(tok);
break;
}
}
}
}
}
}
void CheckExceptionSafety::deallocThrow()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
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// Deallocate a global/member pointer and then throw exception
// the pointer will be a dead pointer
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for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
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// only looking for delete now
if (tok->str() != "delete")
continue;
// Check if this is something similar with: "delete p;"
tok = tok->next();
if (Token::simpleMatch(tok, "[ ]"))
tok = tok->tokAt(2);
if (!tok)
break;
if (!Token::Match(tok, "%var% ;"))
continue;
const unsigned int varid(tok->varId());
if (varid == 0)
continue;
// we only look for global variables
const Variable* var = symbolDatabase->getVariableFromVarId(varid);
if (!var || !(var->isGlobal() || var->isStatic()))
continue;
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// indentlevel..
unsigned int indentlevel = 0;
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// Token where throw occurs
const Token *ThrowToken = 0;
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// is there a throw after the deallocation?
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for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
if (tok2->str() == "{")
++indentlevel;
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else if (tok2->str() == "}") {
if (indentlevel == 0)
break;
--indentlevel;
}
// Throw after delete -> Dead pointer
else if (tok2->str() == "throw") {
if (_settings->inconclusive) { // For inconclusive checking, throw directly.
deallocThrowError(tok2, tok->str());
break;
}
ThrowToken = tok2;
}
// Variable is assigned -> Bail out
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else if (Token::Match(tok2, "%varid% =", varid)) {
if (ThrowToken) // For non-inconclusive checking, wait until we find an assignement to it. Otherwise we assume it is safe to leave a dead pointer.
deallocThrowError(ThrowToken, tok2->str());
break;
}
// Variable passed to function. Assume it becomes assigned -> Bail out
else if (Token::Match(tok2, "[,(] &| %varid% [,)]", varid)) // TODO: No bailout if passed by value or as const reference
break;
}
}
}
//---------------------------------------------------------------------------
// catch(const exception & err)
// {
// throw err; // <- should be just "throw;"
// }
//---------------------------------------------------------------------------
void CheckExceptionSafety::checkRethrowCopy()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type != Scope::eCatch)
continue;
const unsigned int varid = i->classStart->tokAt(-2)->varId();
if (varid) {
for (const Token* tok = i->classStart->next(); tok && tok != i->classEnd; tok = tok->next()) {
if (Token::simpleMatch(tok, "catch (") && tok->next()->link() && tok->next()->link()->next()) // Don't check inner catch - it is handled in another iteration of outer loop.
tok = tok->next()->link()->next()->link();
else if (Token::Match(tok, "throw %varid% ;", varid))
rethrowCopyError(tok, tok->strAt(1));
}
}
}
}
//---------------------------------------------------------------------------
// try {} catch (std::exception err) {} <- Should be "std::exception& err"
//---------------------------------------------------------------------------
void CheckExceptionSafety::checkCatchExceptionByValue()
{
if (!_settings->isEnabled("style"))
return;
const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
if (i->type != Scope::eCatch)
continue;
// Find a pass-by-value declaration in the catch(), excluding basic types
// e.g. catch (std::exception err)
const Variable* var = symbolDatabase->getVariableFromVarId(i->classStart->tokAt(-2)->varId());
if (var && var->isClass() && !var->isPointer() && !var->isReference())
catchExceptionByValueError(i->classDef);
}
}