102 lines
4.2 KiB
C++
102 lines
4.2 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2013 Daniel Marjamäki and 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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// You should use ++ and -- as prefix whenever possible as these are more
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// efficient than postfix operators
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//---------------------------------------------------------------------------
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#include "checkpostfixoperator.h"
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#include "symboldatabase.h"
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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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CheckPostfixOperator instance;
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}
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void CheckPostfixOperator::postfixOperator()
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{
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if (!_settings->isEnabled("performance"))
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return;
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const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
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const std::size_t functions = symbolDatabase->functionScopes.size();
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for (std::size_t i = 0; i < functions; ++i) {
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const Scope * scope = symbolDatabase->functionScopes[i];
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for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
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bool result = false;
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const Variable *var = tok->variable();
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if (var && Token::Match(tok, "%var% ++|--")) {
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if (Token::Match(tok->previous(), ";|{|}") && Token::Match(tok->tokAt(2), ";|,|)")) {
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result = true;
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} else if (tok->strAt(-1) == ",") {
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for (const Token* tok2 = tok->tokAt(2); tok2 != 0 && tok2->str() != ")"; tok2 = tok2->next()) {
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if (tok2->str() == ";") {
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result = true;
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break;
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} else if (tok2->str() == "(")
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tok2 = tok2->link();
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}
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} else if (tok->strAt(-1) == ".") {
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for (const Token* tok2 = tok->tokAt(-2); tok2 != 0; tok2 = tok2->previous()) {
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if (Token::Match(tok2, ";|{|}")) {
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result = true;
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break;
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} else if (Token::Match(tok2, ")|]|>") && tok2->link())
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tok2 = tok2->link();
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else if (tok2->isAssignmentOp() || Token::Match(tok2, "(|["))
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break;
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}
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}
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}
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if (result) {
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if (var->isPointer() || var->isArray())
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continue;
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const Token *decltok = var->nameToken();
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if (Token::Match(decltok->previous(), "iterator|const_iterator|reverse_iterator|const_reverse_iterator")) {
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// the variable is an iterator
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postfixOperatorError(tok);
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} else if (var->type()) {
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// the variable is an instance of class
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postfixOperatorError(tok);
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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 CheckPostfixOperator::postfixOperatorError(const Token *tok)
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{
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reportError(tok, Severity::performance, "postfixOperator",
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"Prefer prefix ++/-- operators for non-primitive types.\n"
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"Prefix ++/-- operators should be preferred for non-primitive types. "
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"Pre-increment/decrement can be more efficient than "
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"post-increment/decrement. Post-increment/decrement usually "
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"involves keeping a copy of the previous value around and "
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"adds a little extra code.");
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}
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