cppcheck/lib/checkpostfixoperator.cpp

87 lines
3.3 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2020 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/>.
*/
//---------------------------------------------------------------------------
// You should use ++ and -- as prefix whenever possible as these are more
// efficient than postfix operators
//---------------------------------------------------------------------------
#include "checkpostfixoperator.h"
#include "settings.h"
#include "symboldatabase.h"
#include "token.h"
#include <cstddef>
//---------------------------------------------------------------------------
// Register this check class (by creating a static instance of it)
namespace {
CheckPostfixOperator instance;
}
// CWE ids used
static const struct CWE CWE398(398U); // Indicator of Poor Code Quality
void CheckPostfixOperator::postfixOperator()
{
if (!mSettings->severity.isEnabled(Severity::performance))
return;
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope * scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
const Variable *var = tok->variable();
if (!var || !Token::Match(tok, "%var% ++|--"))
continue;
const Token* parent = tok->next()->astParent();
if (!parent || parent->str() == ";" || (parent->str() == "," && (!parent->astParent() || parent->astParent()->str() != "("))) {
if (var->isPointer() || var->isArray())
continue;
if (Token::Match(var->nameToken()->previous(), "iterator|const_iterator|reverse_iterator|const_reverse_iterator")) {
// the variable is an iterator
postfixOperatorError(tok);
} else if (var->type()) {
// the variable is an instance of class
postfixOperatorError(tok);
}
}
}
}
}
//---------------------------------------------------------------------------
void CheckPostfixOperator::postfixOperatorError(const Token *tok)
{
reportError(tok, Severity::performance, "postfixOperator",
"Prefer prefix ++/-- operators for non-primitive types.\n"
"Prefix ++/-- operators should be preferred for non-primitive types. "
"Pre-increment/decrement can be more efficient than "
"post-increment/decrement. Post-increment/decrement usually "
"involves keeping a copy of the previous value around and "
"adds a little extra code.", CWE398, Certainty::normal);
}