3521 lines
163 KiB
C++
3521 lines
163 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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#include "checkother.h"
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#include "mathlib.h"
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#include "symboldatabase.h"
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#include <cmath> // fabs()
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#include <stack>
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#include <algorithm> // find_if()
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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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CheckOther instance;
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}
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//----------------------------------------------------------------------------------
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// The return value of fgetc(), getc(), ungetc(), getchar() etc. is an integer value.
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// If this return value is stored in a character variable and then compared
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// to compared to EOF, which is an integer, the comparison maybe be false.
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//
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// Reference:
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// - Ticket #160
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// - http://www.cplusplus.com/reference/cstdio/fgetc/
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// - http://www.cplusplus.com/reference/cstdio/getc/
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// - http://www.cplusplus.com/reference/cstdio/getchar/
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// - http://www.cplusplus.com/reference/cstdio/ungetc/ ...
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//----------------------------------------------------------------------------------
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void CheckOther::checkCastIntToCharAndBack()
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{
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if (!_settings->isEnabled("warning"))
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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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std::map<unsigned int, std::string> vars;
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for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
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if (Token::Match(tok, "%var% = fclose|fflush|fputc|fputs|fscanf|getchar|getc|fgetc|putchar|putc|puts|scanf|sscanf|ungetc (")) {
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const Variable *var = tok->variable();
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if (var && var->typeEndToken()->str() == "char" && !var->typeEndToken()->isSigned()) {
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vars[tok->varId()] = tok->strAt(2);
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}
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} else if (Token::Match(tok, "EOF %comp% ( %var% = fclose|fflush|fputc|fputs|fscanf|getchar|getc|fgetc|putchar|putc|puts|scanf|sscanf|ungetc (")) {
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tok = tok->tokAt(3);
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if (tok && tok->varId()) {
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const Variable *var = tok->variable();
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if (var && var->typeEndToken()->str() == "char" && !var->typeEndToken()->isSigned()) {
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checkCastIntToCharAndBackError(tok, tok->strAt(2));
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}
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}
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} else if (Token::Match(tok, "EOF %comp% ( %var% = std :: cin . get (") || Token::Match(tok, "EOF %comp% ( %var% = cin . get (")) {
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tok = tok->tokAt(3);
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if (tok && tok->varId()) {
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const Variable *var = tok->variable();
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if (var && var->typeEndToken()->str() == "char" && !var->typeEndToken()->isSigned()) {
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checkCastIntToCharAndBackError(tok, "cin.get");
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}
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}
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} else if (Token::Match(tok, "%var% = std :: cin . get (") || Token::Match(tok, "%var% = cin . get (")) {
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const Variable *var = tok->variable();
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if (var && var->typeEndToken()->str() == "char" && !var->typeEndToken()->isSigned()) {
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vars[tok->varId()] = "cin.get";
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}
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}
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if (Token::Match(tok, "%var% %comp% EOF")) {
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if (vars.find(tok->varId()) != vars.end()) {
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checkCastIntToCharAndBackError(tok, vars[tok->varId()]);
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}
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} else if (Token::Match(tok, "EOF %comp% %var%")) {
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tok = tok->tokAt(2);
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if (vars.find(tok->varId()) != vars.end()) {
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checkCastIntToCharAndBackError(tok, vars[tok->varId()]);
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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 CheckOther::checkCastIntToCharAndBackError(const Token *tok, const std::string &strFunctionName)
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{
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reportError(
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tok,
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Severity::warning,
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"checkCastIntToCharAndBack",
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"Storing "+ strFunctionName +"() return value in char variable and then comparing with EOF.\n"
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"When saving "+ strFunctionName +"() return value in char variable there is loss of precision. "
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" When "+ strFunctionName +"() returns EOF this value is truncated. Comparing the char "
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"variable with EOF can have unexpected results. For instance a loop \"while (EOF != (c = "+ strFunctionName +"());\" "
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"loops forever on some compilers/platforms and on other compilers/platforms it will stop "
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"when the file contains a matching character."
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);
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}
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//---------------------------------------------------------------------------
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//---------------------------------------------------------------------------
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void CheckOther::clarifyCalculation()
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{
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if (!_settings->isEnabled("style"))
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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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if (tok->str() == "?") {
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// condition
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const Token *cond = tok->previous();
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if (cond->isName() || cond->isNumber())
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cond = cond->previous();
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else if (cond->str() == ")")
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cond = cond->link()->previous();
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else
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continue;
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if (cond && cond->str() == "!")
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cond = cond->previous();
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if (!cond)
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continue;
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// calculation
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if (!cond->isArithmeticalOp())
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continue;
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const std::string &op = cond->str();
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cond = cond->previous();
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// skip previous multiplications..
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while (cond && cond->previous()) {
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if ((cond->isName() || cond->isNumber()) && cond->previous()->str() == "*")
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cond = cond->tokAt(-2);
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else if (cond->str() == ")")
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cond = cond->link()->previous();
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else
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break;
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}
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if (!cond)
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continue;
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// first multiplication operand
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if (cond->str() == ")") {
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clarifyCalculationError(cond, op);
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} else if (cond->isName() || cond->isNumber()) {
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if (Token::Match(cond->previous(),"return|=|+|-|,|(") || cond->strAt(-1) == op)
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clarifyCalculationError(cond, op);
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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 CheckOther::clarifyCalculationError(const Token *tok, const std::string &op)
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{
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// suspicious calculation
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const std::string calc("'a" + op + "b?c:d'");
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// recommended calculation #1
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const std::string s1("'(a" + op + "b)?c:d'");
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// recommended calculation #2
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const std::string s2("'a" + op + "(b?c:d)'");
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reportError(tok,
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Severity::style,
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"clarifyCalculation",
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"Clarify calculation precedence for '" + op + "' and '?'.\n"
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"Suspicious calculation. Please use parentheses to clarify the code. "
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"The code '" + calc + "' should be written as either '" + s1 + "' or '" + s2 + "'.");
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}
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//---------------------------------------------------------------------------
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// Clarify condition '(x = a < 0)' into '((x = a) < 0)' or '(x = (a < 0))'
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// Clarify condition '(a & b == c)' into '((a & b) == c)' or '(a & (b == c))'
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//---------------------------------------------------------------------------
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void CheckOther::clarifyCondition()
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{
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if (!_settings->isEnabled("style"))
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return;
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const bool isC = _tokenizer->isC();
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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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if (Token::Match(tok, "( %var% [=&|^]")) {
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for (const Token *tok2 = tok->tokAt(3); tok2; tok2 = tok2->next()) {
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if (tok2->str() == "(" || tok2->str() == "[")
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tok2 = tok2->link();
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else if (tok2->type() == Token::eComparisonOp) {
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// This might be a template
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if (!isC && tok2->link())
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break;
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clarifyConditionError(tok, tok->strAt(2) == "=", false);
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break;
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} else if (!tok2->isName() && !tok2->isNumber() && tok2->str() != ".")
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break;
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}
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}
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}
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}
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// using boolean result in bitwise operation ! x [&|^]
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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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if (Token::Match(tok, "%comp%|!")) {
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if (tok->link()) // don't write false positives when templates are used
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continue;
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const Token *tok2 = tok->next();
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// Todo: There are false positives if '(' if encountered. It
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// is assumed there is something like '(char *)&..' and therefore
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// it bails out.
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if (Token::Match(tok2, "(|&"))
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continue;
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while (tok2 && (tok2->isName() || tok2->isNumber() || Token::Match(tok2,".|(|["))) {
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if (Token::Match(tok2, "(|["))
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tok2 = tok2->link();
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tok2 = tok2->next();
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}
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if (Token::Match(tok2, "[&|^]")) {
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// don't write false positives when templates are used
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if (Token::Match(tok2, "&|* ,|>") || Token::simpleMatch(tok2->previous(), "const &"))
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continue;
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// #3609 - CWinTraits<WS_CHILD|WS_VISIBLE>::..
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if (!isC && Token::Match(tok->previous(), "%var% <")) {
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const Token *tok3 = tok2;
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while (Token::Match(tok3, "[&|^] %var%"))
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tok3 = tok3->tokAt(2);
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if (Token::Match(tok3, ",|>"))
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continue;
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}
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clarifyConditionError(tok,false,true);
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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 CheckOther::clarifyConditionError(const Token *tok, bool assign, bool boolop)
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{
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std::string errmsg;
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if (assign)
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errmsg = "Suspicious condition (assignment + comparison); Clarify expression with parentheses.";
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else if (boolop)
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errmsg = "Boolean result is used in bitwise operation. Clarify expression with parentheses.\n"
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"Suspicious expression. Boolean result is used in bitwise operation. The operator '!' "
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"and the comparison operators have higher precedence than bitwise operators. "
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"It is recommended that the expression is clarified with parentheses.";
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else
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errmsg = "Suspicious condition (bitwise operator + comparison); Clarify expression with parentheses.\n"
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"Suspicious condition. Comparison operators have higher precedence than bitwise operators. "
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"Please clarify the condition with parentheses.";
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reportError(tok,
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Severity::style,
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"clarifyCondition",
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errmsg);
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}
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//---------------------------------------------------------------------------
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// Clarify (meaningless) statements like *foo++; with parentheses.
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//---------------------------------------------------------------------------
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void CheckOther::clarifyStatement()
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{
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if (!_settings->isEnabled("warning"))
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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; tok != scope->classEnd; tok = tok->next()) {
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if (Token::Match(tok, "* %var%")) {
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const Token *tok2=tok->previous();
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while (tok2 && tok2->str() == "*")
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tok2=tok2->previous();
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if (Token::Match(tok2, "[{};]")) {
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tok = tok->tokAt(2);
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for (;;) {
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if (tok->str() == "[")
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tok = tok->link()->next();
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if (Token::Match(tok, ".|:: %var%")) {
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if (tok->strAt(2) == "(")
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tok = tok->linkAt(2)->next();
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else
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tok = tok->tokAt(2);
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} else
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break;
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}
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if (Token::Match(tok, "++|-- [;,]"))
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clarifyStatementError(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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void CheckOther::clarifyStatementError(const Token *tok)
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{
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reportError(tok, Severity::warning, "clarifyStatement", "Ineffective statement similar to '*A++;'. Did you intend to write '(*A)++;'?\n"
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"A statement like '*A++;' might not do what you intended. Postfix 'operator++' is executed before 'operator*'. "
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"Thus, the dereference is meaningless. Did you intend to write '(*A)++;'?");
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}
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void CheckOther::checkSuspiciousSemicolon()
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{
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if (!_settings->inconclusive || !_settings->isEnabled("warning"))
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return;
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const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
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// Look for "if(); {}", "for(); {}" or "while(); {}"
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for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
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if (i->type == Scope::eIf || i->type == Scope::eElse || i->type == Scope::eElseIf || i->type == Scope::eWhile || i->type == Scope::eFor) {
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// Ensure the semicolon is at the same line number as the if/for/while statement
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// and the {..} block follows it without an extra empty line.
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if (Token::simpleMatch(i->classStart, "{ ; } {") &&
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i->classStart->previous()->linenr() == i->classStart->tokAt(2)->linenr()
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&& i->classStart->linenr()+1 >= i->classStart->tokAt(3)->linenr()) {
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SuspiciousSemicolonError(i->classDef);
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}
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}
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}
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}
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void CheckOther::SuspiciousSemicolonError(const Token* tok)
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{
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reportError(tok, Severity::warning, "suspiciousSemicolon",
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"Suspicious use of ; at the end of '" + (tok ? tok->str() : std::string()) + "' statement.", true);
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}
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//---------------------------------------------------------------------------
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//---------------------------------------------------------------------------
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void CheckOther::warningOldStylePointerCast()
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{
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// Only valid on C++ code
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if (!_settings->isEnabled("style") || !_tokenizer->isCPP())
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return;
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for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
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// Old style pointer casting..
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if (!Token::Match(tok, "( const| %type% * ) (| %var%") &&
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!Token::Match(tok, "( const| %type% * ) (| new"))
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continue;
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if (tok->strAt(1) == "const")
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tok = tok->next();
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if (tok->strAt(4) == "const")
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continue;
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// Is "type" a class?
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const std::string pattern("class|struct " + tok->strAt(1));
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if (Token::findmatch(_tokenizer->tokens(), pattern.c_str(), tok))
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cstyleCastError(tok);
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}
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}
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void CheckOther::cstyleCastError(const Token *tok)
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{
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reportError(tok, Severity::style, "cstyleCast", "C-style pointer casting");
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}
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//---------------------------------------------------------------------------
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// float* f; double* d = (double*)f; <-- Pointer cast to a type with an incompatible binary data representation
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//---------------------------------------------------------------------------
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static std::string analyzeType(const Token* tok)
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{
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if (tok->str() == "double") {
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if (tok->isLong())
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return "long double";
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else
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return "double";
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}
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if (tok->str() == "float")
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return "float";
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if (Token::Match(tok, "int|long|short|char|size_t"))
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return "integer";
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return "";
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}
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void CheckOther::invalidPointerCast()
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{
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if (!_settings->isEnabled("warning") && !_settings->isEnabled("portability"))
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return;
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const SymbolDatabase* const 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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const Token* toTok = 0;
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const Token* nextTok = 0;
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// Find cast
|
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if (Token::Match(tok, "( const| %type% const| * )") ||
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Token::Match(tok, "( const| %type% %type% const| * )")) {
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toTok = tok->next();
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nextTok = tok->link()->next();
|
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if (nextTok && nextTok->str() == "(")
|
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nextTok = nextTok->next();
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} else if (Token::Match(tok, "reinterpret_cast < const| %type% const| * > (") ||
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Token::Match(tok, "reinterpret_cast < const| %type% %type% const| * > (")) {
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nextTok = tok->tokAt(5);
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while (nextTok->str() != "(")
|
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nextTok = nextTok->next();
|
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nextTok = nextTok->next();
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toTok = tok->tokAt(2);
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}
|
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if (toTok && toTok->str() == "const")
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toTok = toTok->next();
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|
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if (!nextTok || !toTok || !toTok->isStandardType())
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continue;
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|
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// Find casted variable
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const Variable *var = 0;
|
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bool allocation = false;
|
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bool ref = false;
|
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if (Token::Match(nextTok, "new %type%"))
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allocation = true;
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else if (Token::Match(nextTok, "%var% !!["))
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var = nextTok->variable();
|
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else if (Token::Match(nextTok, "& %var%") && !Token::Match(nextTok->tokAt(2), "(|[")) {
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var = nextTok->next()->variable();
|
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ref = true;
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}
|
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|
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const Token* fromTok = 0;
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|
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if (allocation) {
|
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fromTok = nextTok->next();
|
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} else {
|
|
if (!var || (!ref && !var->isPointer() && !var->isArray()) || (ref && (var->isPointer() || var->isArray())))
|
|
continue;
|
|
fromTok = var->typeStartToken();
|
|
}
|
|
|
|
while (Token::Match(fromTok, "static|const"))
|
|
fromTok = fromTok->next();
|
|
if (!fromTok->isStandardType())
|
|
continue;
|
|
|
|
std::string fromType = analyzeType(fromTok);
|
|
std::string toType = analyzeType(toTok);
|
|
if (fromType != toType && !fromType.empty() && !toType.empty() && (toType != "integer" || _settings->isEnabled("portability")) && (toTok->str() != "char" || _settings->inconclusive))
|
|
invalidPointerCastError(tok, fromType, toType, toTok->str() == "char");
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::invalidPointerCastError(const Token* tok, const std::string& from, const std::string& to, bool inconclusive)
|
|
{
|
|
if (to == "integer") { // If we cast something to int*, this can be useful to play with its binary data representation
|
|
if (!inconclusive)
|
|
reportError(tok, Severity::portability, "invalidPointerCast", "Casting from " + from + "* to integer* is not portable due to different binary data representations on different platforms.");
|
|
else
|
|
reportError(tok, Severity::portability, "invalidPointerCast", "Casting from " + from + "* to char* is not portable due to different binary data representations on different platforms.", true);
|
|
} else
|
|
reportError(tok, Severity::warning, "invalidPointerCast", "Casting between " + from + "* and " + to + "* which have an incompatible binary data representation.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// This check detects errors on POSIX systems, when a pipe command called
|
|
// with a wrong dimensioned file descriptor array. The pipe command requires
|
|
// exactly an integer array of dimension two as parameter.
|
|
//
|
|
// References:
|
|
// - http://linux.die.net/man/2/pipe
|
|
// - ticket #3521
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkPipeParameterSize()
|
|
{
|
|
if (!_settings->standards.posix)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "pipe ( %var% )") ||
|
|
Token::Match(tok, "pipe2 ( %var% ,")) {
|
|
const Token * const varTok = tok->tokAt(2);
|
|
|
|
const Variable *var = varTok->variable();
|
|
MathLib::bigint dim;
|
|
if (var && (var->isArray() || var->isPointer()) && !var->isArgument() && ((dim=var->dimension(0U)) < 2)) {
|
|
const std::string strDim = MathLib::longToString(dim);
|
|
checkPipeParameterSizeError(varTok,varTok->str(), strDim);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::checkPipeParameterSizeError(const Token *tok, const std::string &strVarName, const std::string &strDim)
|
|
{
|
|
reportError(tok, Severity::error,
|
|
"wrongPipeParameterSize", "Buffer '" + strVarName + "' must have size of 2 integers if used as parameter of pipe().\n"
|
|
"The pipe()/pipe2() system command takes an argument, which is an array of exactly two integers.\n"
|
|
"The variable '" + strVarName + "' is an array of size " + strDim + ", which does not match.");
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// check usleep(), which is allowed to be called with in a range of [0,999999]
|
|
//
|
|
// Reference:
|
|
// - http://man7.org/linux/man-pages/man3/usleep.3.html
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::checkSleepTimeInterval()
|
|
{
|
|
if (!_settings->standards.posix)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "usleep ( %num% )")) {
|
|
const Token * const numTok = tok->tokAt(2);
|
|
MathLib::bigint value = MathLib::toLongNumber(numTok->str());
|
|
if (value > 999999) { // less than 1 million
|
|
checkSleepTimeError(numTok, numTok->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::checkSleepTimeError(const Token *tok, const std::string &strDim)
|
|
{
|
|
reportError(tok, Severity::error,
|
|
"tooBigSleepTime", "The argument of usleep must be less than 1000000.\n"
|
|
"The argument of usleep must be less than 1000000, but " + strDim + " is provided.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Detect redundant assignments: x = 0; x = 4;
|
|
//---------------------------------------------------------------------------
|
|
|
|
static bool nonLocal(const Variable* var)
|
|
{
|
|
return !var || (!var->isLocal() && !var->isArgument()) || var->isStatic() || var->isReference();
|
|
}
|
|
|
|
static void eraseNotLocalArg(std::map<unsigned int, const Token*>& container, const SymbolDatabase* symbolDatabase)
|
|
{
|
|
for (std::map<unsigned int, const Token*>::iterator i = container.begin(); i != container.end();) {
|
|
const Variable* var = symbolDatabase->getVariableFromVarId(i->first);
|
|
if (!var || nonLocal(var)) {
|
|
container.erase(i++);
|
|
if (i == container.end())
|
|
break;
|
|
} else
|
|
++i;
|
|
}
|
|
}
|
|
|
|
void CheckOther::checkRedundantAssignment()
|
|
{
|
|
bool performance = _settings->isEnabled("performance");
|
|
bool warning = _settings->isEnabled("warning");
|
|
if (!warning && !performance)
|
|
return;
|
|
|
|
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (std::list<Scope>::const_iterator scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
|
|
if (!scope->isExecutable())
|
|
continue;
|
|
|
|
std::map<unsigned int, const Token*> varAssignments;
|
|
std::map<unsigned int, const Token*> memAssignments;
|
|
std::set<unsigned int> initialized;
|
|
const Token* writtenArgumentsEnd = 0;
|
|
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (tok == writtenArgumentsEnd)
|
|
writtenArgumentsEnd = 0;
|
|
|
|
if (tok->str() == "{" && tok->strAt(-1) != "{" && tok->strAt(-1) != "=" && tok->strAt(-4) != "case" && tok->strAt(-3) != "default") { // conditional or non-executable inner scope: Skip it and reset status
|
|
tok = tok->link();
|
|
varAssignments.clear();
|
|
memAssignments.clear();
|
|
} else if (Token::Match(tok, "for|if|while (")) {
|
|
tok = tok->linkAt(1);
|
|
} else if (Token::Match(tok, "break|return|continue|throw|goto")) {
|
|
varAssignments.clear();
|
|
memAssignments.clear();
|
|
} else if (tok->type() == Token::eVariable) {
|
|
// Set initialization flag
|
|
if (!Token::Match(tok, "%var% ["))
|
|
initialized.insert(tok->varId());
|
|
else {
|
|
const Token *tok2 = tok->next();
|
|
while (tok2 && tok2->str() == "[")
|
|
tok2 = tok2->link()->next();
|
|
if (tok2 && tok2->str() != ";")
|
|
initialized.insert(tok->varId());
|
|
}
|
|
|
|
std::map<unsigned int, const Token*>::iterator it = varAssignments.find(tok->varId());
|
|
if (tok->next()->isAssignmentOp() && Token::Match(tok->previous(), "[;{}]")) { // Assignment
|
|
if (it != varAssignments.end()) {
|
|
bool error = true; // Ensure that variable is not used on right side
|
|
for (const Token* tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
|
|
if (tok2->str() == ";")
|
|
break;
|
|
else if (tok2->varId() == tok->varId())
|
|
error = false;
|
|
else if (Token::Match(tok2, "%var% (") && nonLocal(tok->variable())) { // Called function might use the variable
|
|
const Function* func = tok2->function();
|
|
const Variable* var = tok->variable();
|
|
if (!var || var->isGlobal() || var->isReference() || ((!func || func->nestedIn) && tok2->strAt(-1) != ".")) // Global variable, or member function
|
|
error = false;
|
|
}
|
|
}
|
|
if (error) {
|
|
if (scope->type == Scope::eSwitch && Token::findmatch(it->second, "default|case", tok) && warning)
|
|
redundantAssignmentInSwitchError(it->second, tok, tok->str());
|
|
else if (performance)
|
|
redundantAssignmentError(it->second, tok, tok->str(), nonLocal(it->second->variable())); // Inconclusive for non-local variables
|
|
}
|
|
it->second = tok;
|
|
}
|
|
if (Token::simpleMatch(tok->tokAt(2), "0 ;"))
|
|
varAssignments.erase(tok->varId());
|
|
else
|
|
varAssignments[tok->varId()] = tok;
|
|
memAssignments.erase(tok->varId());
|
|
} else if (tok->next()->type() == Token::eIncDecOp || (tok->previous()->type() == Token::eIncDecOp && !Token::Match(tok->next(), ".|[|("))) { // Variable incremented/decremented
|
|
varAssignments[tok->varId()] = tok;
|
|
memAssignments.erase(tok->varId());
|
|
} else if (!Token::simpleMatch(tok->tokAt(-2), "sizeof (")) { // Other usage of variable
|
|
if (it != varAssignments.end())
|
|
varAssignments.erase(it);
|
|
if (!writtenArgumentsEnd) // Indicates that we are in the first argument of strcpy/memcpy/... function
|
|
memAssignments.erase(tok->varId());
|
|
}
|
|
} else if (Token::Match(tok, "%var% (")) { // Function call. Global variables might be used. Reset their status
|
|
bool memfunc = Token::Match(tok, "memcpy|memmove|memset|strcpy|strncpy|sprintf|snprintf|strcat|strncat|wcscpy|wcsncpy|swprintf|wcscat|wcsncat");
|
|
if (memfunc) {
|
|
const Token* param1 = tok->tokAt(2);
|
|
writtenArgumentsEnd = param1->next();
|
|
if (param1->varId() && param1->strAt(1) == "," && !Token::Match(tok, "strcat|strncat|wcscat|wcsncat")) {
|
|
if (tok->str() == "memset" && initialized.find(param1->varId()) == initialized.end() && param1->variable() && param1->variable()->isLocal() && param1->variable()->isArray())
|
|
initialized.insert(param1->varId());
|
|
else if (memAssignments.find(param1->varId()) == memAssignments.end())
|
|
memAssignments[param1->varId()] = tok;
|
|
else {
|
|
const std::map<unsigned int, const Token*>::iterator it = memAssignments.find(param1->varId());
|
|
if (scope->type == Scope::eSwitch && Token::findmatch(it->second, "default|case", tok) && warning)
|
|
redundantCopyInSwitchError(it->second, tok, param1->str());
|
|
else if (performance)
|
|
redundantCopyError(it->second, tok, param1->str());
|
|
}
|
|
}
|
|
} else if (scope->type == Scope::eSwitch) { // Avoid false positives if noreturn function is called in switch
|
|
const Function* func = tok->function();
|
|
if (!func || !func->hasBody) {
|
|
varAssignments.clear();
|
|
memAssignments.clear();
|
|
continue;
|
|
}
|
|
const Token* funcEnd = func->functionScope->classEnd;
|
|
bool noreturn;
|
|
if (!_tokenizer->IsScopeNoReturn(funcEnd, &noreturn) && !noreturn) {
|
|
eraseNotLocalArg(varAssignments, symbolDatabase);
|
|
eraseNotLocalArg(memAssignments, symbolDatabase);
|
|
} else {
|
|
varAssignments.clear();
|
|
memAssignments.clear();
|
|
}
|
|
} else { // Noreturn functions outside switch don't cause problems
|
|
eraseNotLocalArg(varAssignments, symbolDatabase);
|
|
eraseNotLocalArg(memAssignments, symbolDatabase);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::redundantCopyError(const Token *tok1, const Token* tok2, const std::string& var)
|
|
{
|
|
std::list<const Token*> callstack;
|
|
callstack.push_back(tok1);
|
|
callstack.push_back(tok2);
|
|
reportError(callstack, Severity::performance, "redundantCopy",
|
|
"Buffer '" + var + "' is being written before its old content has been used.");
|
|
}
|
|
|
|
void CheckOther::redundantCopyInSwitchError(const Token *tok1, const Token* tok2, const std::string &var)
|
|
{
|
|
std::list<const Token*> callstack;
|
|
callstack.push_back(tok1);
|
|
callstack.push_back(tok2);
|
|
reportError(callstack, Severity::warning, "redundantCopyInSwitch",
|
|
"Buffer '" + var + "' is being written before its old content has been used. 'break;' missing?");
|
|
}
|
|
|
|
void CheckOther::redundantAssignmentError(const Token *tok1, const Token* tok2, const std::string& var, bool inconclusive)
|
|
{
|
|
std::list<const Token*> callstack;
|
|
callstack.push_back(tok1);
|
|
callstack.push_back(tok2);
|
|
if (inconclusive)
|
|
reportError(callstack, Severity::performance, "redundantAssignment",
|
|
"Variable '" + var + "' is reassigned a value before the old one has been used if variable is no semaphore variable.\n"
|
|
"Variable '" + var + "' is reassigned a value before the old one has been used. Make sure that this variable is not used like a semaphore in a threading environment before simplifying this code.", true);
|
|
else
|
|
reportError(callstack, Severity::performance, "redundantAssignment",
|
|
"Variable '" + var + "' is reassigned a value before the old one has been used.");
|
|
}
|
|
|
|
void CheckOther::redundantAssignmentInSwitchError(const Token *tok1, const Token* tok2, const std::string &var)
|
|
{
|
|
std::list<const Token*> callstack;
|
|
callstack.push_back(tok1);
|
|
callstack.push_back(tok2);
|
|
reportError(callstack, Severity::warning, "redundantAssignInSwitch",
|
|
"Variable '" + var + "' is reassigned a value before the old one has been used. 'break;' missing?");
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// switch (x)
|
|
// {
|
|
// case 2:
|
|
// y = a; // <- this assignment is redundant
|
|
// case 3:
|
|
// y = b; // <- case 2 falls through and sets y twice
|
|
// }
|
|
//---------------------------------------------------------------------------
|
|
static inline bool isFunctionOrBreakPattern(const Token *tok)
|
|
{
|
|
if (Token::Match(tok, "%var% (") || Token::Match(tok, "break|continue|return|exit|goto|throw"))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
void CheckOther::checkRedundantAssignmentInSwitch()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
// Find the beginning of a switch. E.g.:
|
|
// switch (var) { ...
|
|
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
|
|
if (i->type != Scope::eSwitch || !i->classStart)
|
|
continue;
|
|
|
|
// Check the contents of the switch statement
|
|
std::map<unsigned int, const Token*> varsWithBitsSet;
|
|
std::map<unsigned int, std::string> bitOperations;
|
|
|
|
for (const Token *tok2 = i->classStart->next(); tok2 != i->classEnd; tok2 = tok2->next()) {
|
|
if (tok2->str() == "{") {
|
|
// Inside a conditional or loop. Don't mark variable accesses as being redundant. E.g.:
|
|
// case 3: b = 1;
|
|
// case 4: if (a) { b = 2; } // Doesn't make the b=1 redundant because it's conditional
|
|
if (Token::Match(tok2->previous(), ")|else {") && tok2->link()) {
|
|
const Token* endOfConditional = tok2->link();
|
|
for (const Token* tok3 = tok2; tok3 != endOfConditional; tok3 = tok3->next()) {
|
|
if (tok3->varId() != 0) {
|
|
varsWithBitsSet.erase(tok3->varId());
|
|
bitOperations.erase(tok3->varId());
|
|
} else if (isFunctionOrBreakPattern(tok3)) {
|
|
varsWithBitsSet.clear();
|
|
bitOperations.clear();
|
|
}
|
|
}
|
|
tok2 = endOfConditional;
|
|
}
|
|
}
|
|
|
|
// Variable assignment. Report an error if it's assigned to twice before a break. E.g.:
|
|
// case 3: b = 1; // <== redundant
|
|
// case 4: b = 2;
|
|
|
|
if (Token::Match(tok2->previous(), ";|{|}|: %var% = %any% ;") && tok2->varId() != 0) {
|
|
varsWithBitsSet.erase(tok2->varId());
|
|
bitOperations.erase(tok2->varId());
|
|
}
|
|
|
|
// Bitwise operation. Report an error if it's performed twice before a break. E.g.:
|
|
// case 3: b |= 1; // <== redundant
|
|
// case 4: b |= 1;
|
|
else if (Token::Match(tok2->previous(), ";|{|}|: %var% = %var% %or%|& %num% ;") &&
|
|
tok2->varId() != 0 && tok2->varId() == tok2->tokAt(2)->varId()) {
|
|
std::string bitOp = tok2->strAt(3) + tok2->strAt(4);
|
|
std::map<unsigned int, const Token*>::iterator i2 = varsWithBitsSet.find(tok2->varId());
|
|
|
|
// This variable has not had a bit operation performed on it yet, so just make a note of it
|
|
if (i2 == varsWithBitsSet.end()) {
|
|
varsWithBitsSet[tok2->varId()] = tok2;
|
|
bitOperations[tok2->varId()] = bitOp;
|
|
}
|
|
|
|
// The same bit operation has been performed on the same variable twice, so report an error
|
|
else if (bitOperations[tok2->varId()] == bitOp)
|
|
redundantBitwiseOperationInSwitchError(i2->second, i2->second->str());
|
|
|
|
// A different bit operation was performed on the variable, so clear it
|
|
else {
|
|
varsWithBitsSet.erase(tok2->varId());
|
|
bitOperations.erase(tok2->varId());
|
|
}
|
|
}
|
|
|
|
// Not a simple assignment so there may be good reason if this variable is assigned to twice. E.g.:
|
|
// case 3: b = 1;
|
|
// case 4: b++;
|
|
else if (tok2->varId() != 0 && tok2->strAt(1) != "|" && tok2->strAt(1) != "&") {
|
|
varsWithBitsSet.erase(tok2->varId());
|
|
bitOperations.erase(tok2->varId());
|
|
}
|
|
|
|
// Reset our record of assignments if there is a break or function call. E.g.:
|
|
// case 3: b = 1; break;
|
|
if (isFunctionOrBreakPattern(tok2)) {
|
|
varsWithBitsSet.clear();
|
|
bitOperations.clear();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::redundantBitwiseOperationInSwitchError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::warning,
|
|
"redundantBitwiseOperationInSwitch", "Redundant bitwise operation on '" + varname + "' in 'switch' statement. 'break;' missing?");
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkSwitchCaseFallThrough()
|
|
{
|
|
if (!(_settings->isEnabled("style") && _settings->experimental))
|
|
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::eSwitch || !i->classStart) // Find the beginning of a switch
|
|
continue;
|
|
|
|
// Check the contents of the switch statement
|
|
std::stack<std::pair<Token *, bool> > ifnest;
|
|
std::stack<Token *> loopnest;
|
|
std::stack<Token *> scopenest;
|
|
bool justbreak = true;
|
|
bool firstcase = true;
|
|
for (const Token *tok2 = i->classStart; tok2 != i->classEnd; tok2 = tok2->next()) {
|
|
if (Token::simpleMatch(tok2, "if (")) {
|
|
tok2 = tok2->next()->link()->next();
|
|
if (tok2->link() == NULL) {
|
|
std::ostringstream errmsg;
|
|
errmsg << "unmatched if in switch: " << tok2->linenr();
|
|
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
|
|
break;
|
|
}
|
|
ifnest.push(std::make_pair(tok2->link(), false));
|
|
justbreak = false;
|
|
} else if (Token::simpleMatch(tok2, "while (")) {
|
|
tok2 = tok2->next()->link()->next();
|
|
// skip over "do { } while ( ) ;" case
|
|
if (tok2->str() == "{") {
|
|
if (tok2->link() == NULL) {
|
|
std::ostringstream errmsg;
|
|
errmsg << "unmatched while in switch: " << tok2->linenr();
|
|
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
|
|
break;
|
|
}
|
|
loopnest.push(tok2->link());
|
|
}
|
|
justbreak = false;
|
|
} else if (Token::simpleMatch(tok2, "do {")) {
|
|
tok2 = tok2->next();
|
|
if (tok2->link() == NULL) {
|
|
std::ostringstream errmsg;
|
|
errmsg << "unmatched do in switch: " << tok2->linenr();
|
|
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
|
|
break;
|
|
}
|
|
loopnest.push(tok2->link());
|
|
justbreak = false;
|
|
} else if (Token::simpleMatch(tok2, "for (")) {
|
|
tok2 = tok2->next()->link()->next();
|
|
if (tok2->link() == NULL) {
|
|
std::ostringstream errmsg;
|
|
errmsg << "unmatched for in switch: " << tok2->linenr();
|
|
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
|
|
break;
|
|
}
|
|
loopnest.push(tok2->link());
|
|
justbreak = false;
|
|
} else if (Token::simpleMatch(tok2, "switch (")) {
|
|
// skip over nested switch, we'll come to that soon
|
|
tok2 = tok2->next()->link()->next()->link();
|
|
} else if (Token::Match(tok2, "break|continue|return|exit|goto|throw")) {
|
|
if (loopnest.empty()) {
|
|
justbreak = true;
|
|
}
|
|
tok2 = Token::findsimplematch(tok2, ";");
|
|
} else if (Token::Match(tok2, "case|default")) {
|
|
if (!justbreak && !firstcase) {
|
|
switchCaseFallThrough(tok2);
|
|
}
|
|
tok2 = Token::findsimplematch(tok2, ":");
|
|
justbreak = true;
|
|
firstcase = false;
|
|
} else if (tok2->str() == "{") {
|
|
scopenest.push(tok2->link());
|
|
} else if (tok2->str() == "}") {
|
|
if (!ifnest.empty() && tok2 == ifnest.top().first) {
|
|
if (tok2->next()->str() == "else") {
|
|
tok2 = tok2->tokAt(2);
|
|
ifnest.pop();
|
|
if (tok2->link() == NULL) {
|
|
std::ostringstream errmsg;
|
|
errmsg << "unmatched if in switch: " << tok2->linenr();
|
|
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
|
|
break;
|
|
}
|
|
ifnest.push(std::make_pair(tok2->link(), justbreak));
|
|
justbreak = false;
|
|
} else {
|
|
justbreak &= ifnest.top().second;
|
|
ifnest.pop();
|
|
}
|
|
} else if (!loopnest.empty() && tok2 == loopnest.top()) {
|
|
loopnest.pop();
|
|
} else if (!scopenest.empty() && tok2 == scopenest.top()) {
|
|
scopenest.pop();
|
|
} else {
|
|
if (!ifnest.empty() || !loopnest.empty() || !scopenest.empty()) {
|
|
std::ostringstream errmsg;
|
|
errmsg << "unexpected end of switch: ";
|
|
errmsg << "ifnest=" << ifnest.size();
|
|
if (!ifnest.empty())
|
|
errmsg << "," << ifnest.top().first->linenr();
|
|
errmsg << ", loopnest=" << loopnest.size();
|
|
if (!loopnest.empty())
|
|
errmsg << "," << loopnest.top()->linenr();
|
|
errmsg << ", scopenest=" << scopenest.size();
|
|
if (!scopenest.empty())
|
|
errmsg << "," << scopenest.top()->linenr();
|
|
reportError(_tokenizer->tokens(), Severity::debug, "debug", errmsg.str());
|
|
}
|
|
// end of switch block
|
|
break;
|
|
}
|
|
} else if (tok2->str() != ";") {
|
|
justbreak = false;
|
|
}
|
|
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::switchCaseFallThrough(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::style,
|
|
"switchCaseFallThrough", "Switch falls through case without comment. 'break;' missing?");
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check for statements like case A||B: in switch()
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkSuspiciousCaseInSwitch()
|
|
{
|
|
if (!_settings->inconclusive || !_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
|
|
if (i->type != Scope::eSwitch)
|
|
continue;
|
|
|
|
for (const Token* tok = i->classStart->next(); tok != i->classEnd; tok = tok->next()) {
|
|
if (tok->str() == "case") {
|
|
const Token* end = 0;
|
|
for (const Token* tok2 = tok->next(); tok2; tok2 = tok2->next()) {
|
|
if (tok2->str() == ":") {
|
|
end = tok2;
|
|
break;
|
|
}
|
|
if (Token::Match(tok2, "[?;}{]")) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (end) {
|
|
const Token* finding = Token::findmatch(tok->next(), "&&|%oror%", end);
|
|
if (finding)
|
|
suspiciousCaseInSwitchError(tok, finding->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::suspiciousCaseInSwitchError(const Token* tok, const std::string& operatorString)
|
|
{
|
|
reportError(tok, Severity::warning, "suspiciousCase",
|
|
"Found suspicious case label in switch(). Operator '" + operatorString + "' probably doesn't work as intended.\n"
|
|
"Using an operator like '" + operatorString + "' in a case label is suspicious. Did you intend to use a bitwise operator, multiple case labels or if/else instead?", true);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// if (x == 1)
|
|
// x == 0; // <- suspicious equality comparison.
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkSuspiciousEqualityComparison()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
|
|
if (Token::simpleMatch(tok, "for (")) {
|
|
const Token* const openParen = tok->next();
|
|
const Token* const closeParen = tok->linkAt(1);
|
|
|
|
// Search for any suspicious equality comparison in the initialization
|
|
// or increment-decrement parts of the for() loop.
|
|
// For example:
|
|
// for (i == 2; i < 10; i++)
|
|
// or
|
|
// for (i = 0; i < 10; i == a)
|
|
const Token* tok2 = Token::findmatch(openParen, "[;(] %var% == %any% [;)]", closeParen);
|
|
if (tok2 && (tok2 == openParen || tok2->tokAt(4) == closeParen)) {
|
|
suspiciousEqualityComparisonError(tok2->tokAt(2));
|
|
}
|
|
|
|
// Equality comparisons with 0 are simplified to negation. For instance,
|
|
// (x == 0) is simplified to (!x), so also check for suspicious negation
|
|
// in the initialization or increment-decrement parts of the for() loop.
|
|
// For example:
|
|
// for (!i; i < 10; i++)
|
|
const Token* tok3 = Token::findmatch(openParen, "[;(] ! %var% [;)]", closeParen);
|
|
if (tok3 && (tok3 == openParen || tok3->tokAt(3) == closeParen)) {
|
|
suspiciousEqualityComparisonError(tok3->tokAt(2));
|
|
}
|
|
|
|
// Skip over for() loop conditions because "for (;running==1;)"
|
|
// is a bit strange, but not necessarily incorrect.
|
|
tok = closeParen;
|
|
} else if (Token::Match(tok, "[;{}] *| %var% == %any% ;")) {
|
|
|
|
// Exclude compound statements surrounded by parentheses, such as
|
|
// printf("%i\n", ({x==0;}));
|
|
// because they may appear as an expression in GNU C/C++.
|
|
// See http://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
|
|
const Token* afterStatement = tok->strAt(1) == "*" ? tok->tokAt(6) : tok->tokAt(5);
|
|
if (!Token::simpleMatch(afterStatement, "} )"))
|
|
suspiciousEqualityComparisonError(tok->next());
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::suspiciousEqualityComparisonError(const Token* tok)
|
|
{
|
|
reportError(tok, Severity::warning, "suspiciousEqualityComparison",
|
|
"Found suspicious equality comparison. Did you intend to assign a value instead?", true);
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// int x = 1;
|
|
// x = x; // <- redundant assignment to self
|
|
//
|
|
// int y = y; // <- redundant initialization to self
|
|
//---------------------------------------------------------------------------
|
|
static bool isTypeWithoutSideEffects(const Tokenizer *tokenizer, const Variable* var)
|
|
{
|
|
return ((var && (!var->isClass() || var->isPointer() || Token::simpleMatch(var->typeStartToken(), "std ::"))) || !tokenizer->isCPP());
|
|
}
|
|
|
|
static inline const Token *findSelfAssignPattern(const Token *start)
|
|
{
|
|
return Token::findmatch(start, "%var% = %var% ;|=|)");
|
|
}
|
|
|
|
void CheckOther::checkSelfAssignment()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const Token *tok = findSelfAssignPattern(_tokenizer->tokens());
|
|
while (tok) {
|
|
if (Token::Match(tok->previous(), "[;{}.]") &&
|
|
tok->varId() && tok->varId() == tok->tokAt(2)->varId() &&
|
|
isTypeWithoutSideEffects(_tokenizer, tok->variable())) {
|
|
bool err = true;
|
|
|
|
// no false positive for 'x = x ? x : 1;'
|
|
// it is simplified to 'if (x) { x=x; } else { x=1; }'. The simplification
|
|
// always write all tokens on 1 line (even if the statement is several lines), so
|
|
// check if the linenr is the same for all the tokens.
|
|
if (Token::Match(tok->tokAt(-2), ") { %var% = %var% ; } else { %varid% =", tok->varId())) {
|
|
// Find the 'if' token
|
|
const Token *tokif = tok->linkAt(-2)->previous();
|
|
|
|
// find the '}' that terminates the 'else'-block
|
|
const Token *else_end = tok->linkAt(6);
|
|
|
|
if (tokif && else_end && tokif->linenr() == else_end->linenr())
|
|
err = false;
|
|
}
|
|
|
|
if (err)
|
|
selfAssignmentError(tok, tok->str());
|
|
}
|
|
|
|
tok = findSelfAssignPattern(tok->next());
|
|
}
|
|
}
|
|
|
|
void CheckOther::selfAssignmentError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::warning,
|
|
"selfAssignment", "Redundant assignment of '" + varname + "' to itself.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// int a = 1;
|
|
// assert(a = 2); // <- assert should not have a side-effect
|
|
//---------------------------------------------------------------------------
|
|
static inline const Token *findAssertPattern(const Token *start)
|
|
{
|
|
return Token::findmatch(start, "assert ( %any%");
|
|
}
|
|
|
|
void CheckOther::checkAssignmentInAssert()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const Token *tok = findAssertPattern(_tokenizer->tokens());
|
|
const Token *endTok = tok ? tok->next()->link() : NULL;
|
|
|
|
while (tok && endTok) {
|
|
for (tok = tok->tokAt(2); tok != endTok; tok = tok->next()) {
|
|
if (tok->isName() && (tok->next()->isAssignmentOp() || tok->next()->type() == Token::eIncDecOp))
|
|
assignmentInAssertError(tok, tok->str());
|
|
else if (Token::Match(tok, "--|++ %var%"))
|
|
assignmentInAssertError(tok, tok->strAt(1));
|
|
}
|
|
|
|
tok = findAssertPattern(endTok->next());
|
|
endTok = tok ? tok->next()->link() : NULL;
|
|
}
|
|
}
|
|
|
|
void CheckOther::assignmentInAssertError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::warning,
|
|
"assignmentInAssert", "Assert statement modifies '" + varname + "'.\n"
|
|
"Variable '" + varname + "' is modified insert assert statement. "
|
|
"Assert statements are removed from release builds so the code inside "
|
|
"assert statement is not executed. If the code is needed also in release "
|
|
"builds, this is a bug.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// if ((x != 1) || (x != 3)) // expression always true
|
|
// if ((x == 1) && (x == 3)) // expression always false
|
|
// if ((x < 1) && (x > 3)) // expression always false
|
|
// if ((x > 3) || (x < 10)) // expression always true
|
|
// if ((x > 5) && (x != 1)) // second comparison always true
|
|
//
|
|
// Check for suspect logic for an expression consisting of 2 comparison
|
|
// expressions with a shared variable and constants and a logical operator
|
|
// between them.
|
|
//
|
|
// Suggest a different logical operator when the logical operator between
|
|
// the comparisons is probably wrong.
|
|
//
|
|
// Inform that second comparison is always true when first comparison is true.
|
|
//---------------------------------------------------------------------------
|
|
|
|
enum Position { First, Second, NA };
|
|
enum Relation { Equal, NotEqual, Less, LessEqual, More, MoreEqual };
|
|
struct Condition {
|
|
Position position;
|
|
const char *opTokStr;
|
|
};
|
|
|
|
static std::string invertOperatorForOperandSwap(std::string s)
|
|
{
|
|
for (std::string::size_type i = 0; i < s.length(); i++) {
|
|
if (s[i] == '>')
|
|
s[i] = '<';
|
|
else if (s[i] == '<')
|
|
s[i] = '>';
|
|
}
|
|
return s;
|
|
}
|
|
|
|
static bool analyzeLogicOperatorCondition(const Condition& c1, const Condition& c2,
|
|
bool inv1, bool inv2,
|
|
bool varFirst1, bool varFirst2,
|
|
const std::string& firstConstant, const std::string& secondConstant,
|
|
const Token* op1Tok, const Token* op3Tok,
|
|
Relation relation)
|
|
{
|
|
if (!(c1.position == NA || (c1.position == First && varFirst1) || (c1.position == Second && !varFirst1)))
|
|
return false;
|
|
|
|
if (!(c2.position == NA || (c2.position == First && varFirst2) || (c2.position == Second && !varFirst2)))
|
|
return false;
|
|
|
|
if (!Token::Match(op1Tok, inv1?invertOperatorForOperandSwap(c1.opTokStr).c_str():c1.opTokStr))
|
|
return false;
|
|
|
|
if (!Token::Match(op3Tok, inv2?invertOperatorForOperandSwap(c2.opTokStr).c_str():c2.opTokStr))
|
|
return false;
|
|
|
|
return (relation == Equal && MathLib::isEqual(firstConstant, secondConstant)) ||
|
|
(relation == NotEqual && MathLib::isNotEqual(firstConstant, secondConstant)) ||
|
|
(relation == Less && MathLib::isLess(firstConstant, secondConstant)) ||
|
|
(relation == LessEqual && MathLib::isLessEqual(firstConstant, secondConstant)) ||
|
|
(relation == More && MathLib::isGreater(firstConstant, secondConstant)) ||
|
|
(relation == MoreEqual && MathLib::isGreaterEqual(firstConstant, secondConstant));
|
|
}
|
|
|
|
void CheckOther::checkIncorrectLogicOperator()
|
|
{
|
|
bool style = _settings->isEnabled("style");
|
|
bool warning = _settings->isEnabled("warning");
|
|
if (!style && !warning)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t ii = 0; ii < functions; ++ii) {
|
|
const Scope * scope = symbolDatabase->functionScopes[ii];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
// Find a pair of comparison expressions with or without parentheses
|
|
// with a shared variable and constants and with a logical operator between them.
|
|
// e.g. if (x != 3 || x != 4)
|
|
const Token *term1Tok = NULL, *term2Tok = NULL;
|
|
const Token *op1Tok = NULL, *op2Tok = NULL, *op3Tok = NULL, *nextTok = NULL;
|
|
|
|
if (Token::Match(tok, "( %any% %comp% %any% ) &&|%oror%")) {
|
|
term1Tok = tok->next();
|
|
op1Tok = tok->tokAt(2);
|
|
op2Tok = tok->tokAt(5);
|
|
} else if (Token::Match(tok, "%any% %comp% %any% &&|%oror%")) {
|
|
term1Tok = tok;
|
|
op1Tok = tok->next();
|
|
op2Tok = tok->tokAt(3);
|
|
}
|
|
if (op2Tok) {
|
|
if (Token::Match(op2Tok->next(), "( %any% %comp% %any% ) %any%")) {
|
|
term2Tok = op2Tok->tokAt(2);
|
|
op3Tok = op2Tok->tokAt(3);
|
|
nextTok = op2Tok->tokAt(6);
|
|
} else if (Token::Match(op2Tok->next(), "%any% %comp% %any% %any%")) {
|
|
term2Tok = op2Tok->next();
|
|
op3Tok = op2Tok->tokAt(2);
|
|
nextTok = op2Tok->tokAt(4);
|
|
}
|
|
}
|
|
|
|
if (nextTok) {
|
|
// Find the common variable and the two different-valued constants
|
|
std::string firstConstant, secondConstant;
|
|
bool varFirst1, varFirst2;
|
|
unsigned int varId;
|
|
const Token *var1Tok = NULL, *var2Tok = NULL;
|
|
if (Token::Match(term1Tok, "%var% %any% %num%")) {
|
|
var1Tok = term1Tok;
|
|
varId = var1Tok->varId();
|
|
if (!varId) {
|
|
continue;
|
|
}
|
|
varFirst1 = true;
|
|
firstConstant = term1Tok->strAt(2);
|
|
} else if (Token::Match(term1Tok, "%num% %any% %var%")) {
|
|
var1Tok = term1Tok->tokAt(2);
|
|
varId = var1Tok->varId();
|
|
if (!varId) {
|
|
continue;
|
|
}
|
|
varFirst1 = false;
|
|
firstConstant = term1Tok->str();
|
|
} else {
|
|
continue;
|
|
}
|
|
|
|
if (Token::Match(term2Tok, "%var% %any% %num%")) {
|
|
var2Tok = term2Tok;
|
|
varFirst2 = true;
|
|
secondConstant = term2Tok->strAt(2);
|
|
} else if (Token::Match(term2Tok, "%num% %any% %var%")) {
|
|
var2Tok = term2Tok->tokAt(2);
|
|
varFirst2 = false;
|
|
secondConstant = term2Tok->str();
|
|
} else {
|
|
continue;
|
|
}
|
|
|
|
if (varId != var2Tok->varId() || firstConstant.empty() || secondConstant.empty()) {
|
|
continue;
|
|
}
|
|
|
|
enum LogicError { AlwaysFalse, AlwaysTrue, FirstTrue, FirstFalse, SecondTrue, SecondFalse };
|
|
|
|
static const struct LinkedConditions {
|
|
const char *before;
|
|
Condition c1;
|
|
const char *op2TokStr;
|
|
Condition c2;
|
|
const char *after;
|
|
Relation relation;
|
|
LogicError error;
|
|
} conditions[] = {
|
|
{ "!!&&", { NA, "!=" }, "%oror%", { NA, "!=" }, "!!&&", NotEqual, AlwaysTrue }, // (x != 1) || (x != 3) <- always true
|
|
{ 0, { NA, "==" }, "&&", { NA, "==" }, 0, NotEqual, AlwaysFalse }, // (x == 1) && (x == 3) <- always false
|
|
{ "!!&&", { First, ">" }, "%oror%", { First, "<" }, "!!&&", Less, AlwaysTrue }, // (x > 3) || (x < 10) <- always true
|
|
{ "!!&&", { First, ">=" }, "%oror%", { First, "<|<=" }, "!!&&", LessEqual, AlwaysTrue }, // (x >= 3) || (x < 10) <- always true
|
|
{ "!!&&", { First, ">" }, "%oror%", { First, "<=" }, "!!&&", LessEqual, AlwaysTrue }, // (x > 3) || (x <= 10) <- always true
|
|
{ 0, { First, "<" }, "&&", { First, ">" }, 0, LessEqual, AlwaysFalse }, // (x < 1) && (x > 3) <- always false
|
|
{ 0, { First, "<=" }, "&&", { First, ">|>=" }, 0, Less, AlwaysFalse }, // (x <= 1) && (x > 3) <- always false
|
|
{ 0, { First, "<" }, "&&", { First, ">=" }, 0, Less, AlwaysFalse }, // (x < 1) && (x >= 3) <- always false
|
|
{ 0, { First, ">" }, "&&", { NA, "==" }, 0, MoreEqual, AlwaysFalse }, // (x > 5) && (x == 1) <- always false
|
|
{ 0, { First, "<" }, "&&", { NA, "==" }, 0, LessEqual, AlwaysFalse }, // (x < 1) && (x == 3) <- always false
|
|
{ 0, { First, ">=" }, "&&", { NA, "==" }, 0, More, AlwaysFalse }, // (x >= 5) && (x == 1) <- always false
|
|
{ 0, { First, "<=" }, "&&", { NA, "==" }, 0, Less, AlwaysFalse }, // (x <= 1) && (x == 3) <- always false
|
|
{ "!!&&", { NA, "==" }, "%oror%", { First, ">" }, "!!&&", More, SecondTrue }, // (x == 4) || (x > 3) <- second expression always true
|
|
{ "!!&&", { NA, "==" }, "%oror%", { First, "<" }, "!!&&", Less, SecondTrue }, // (x == 4) || (x < 5) <- second expression always true
|
|
{ "!!&&", { NA, "==" }, "%oror%", { First, ">=" }, "!!&&", MoreEqual, SecondTrue }, // (x == 4) || (x >= 3) <- second expression always true
|
|
{ "!!&&", { NA, "==" }, "%oror%", { First, "<=" }, "!!&&", LessEqual, SecondTrue }, // (x == 4) || (x <= 5) <- second expression always true
|
|
{ "!!&&", { First, ">" }, "%oror%", { NA, "!=" }, "!!&&", MoreEqual, SecondTrue }, // (x > 5) || (x != 1) <- second expression always true
|
|
{ "!!&&", { First, "<" }, "%oror%", { NA, "!=" }, "!!&&", LessEqual, SecondTrue }, // (x < 1) || (x != 3) <- second expression always true
|
|
{ "!!&&", { First, ">=" }, "%oror%", { NA, "!=" }, "!!&&", More, SecondTrue }, // (x >= 5) || (x != 1) <- second expression always true
|
|
{ "!!&&", { First, "<=" }, "%oror%", { NA, "!=" }, "!!&&", Less, SecondTrue }, // (x <= 1) || (x != 3) <- second expression always true
|
|
{ 0, { First, ">" }, "&&", { NA, "!=" }, 0, MoreEqual, SecondTrue }, // (x > 5) && (x != 1) <- second expression always true
|
|
{ 0, { First, "<" }, "&&", { NA, "!=" }, 0, LessEqual, SecondTrue }, // (x < 1) && (x != 3) <- second expression always true
|
|
{ 0, { First, ">=" }, "&&", { NA, "!=" }, 0, More, SecondTrue }, // (x >= 5) && (x != 1) <- second expression always true
|
|
{ 0, { First, "<=" }, "&&", { NA, "!=" }, 0, Less, SecondTrue }, // (x <= 1) && (x != 3) <- second expression always true
|
|
{ "!!&&", { First, ">|>=" }, "%oror%", { First, ">|>=" }, "!!&&", LessEqual, SecondTrue }, // (x > 4) || (x > 5) <- second expression always true
|
|
{ "!!&&", { First, "<|<=" }, "%oror%", { First, "<|<=" }, "!!&&", MoreEqual, SecondTrue }, // (x < 5) || (x < 4) <- second expression always true
|
|
{ 0, { First, ">|>=" }, "&&", { First, ">|>=" }, 0, MoreEqual, SecondTrue }, // (x > 4) && (x > 5) <- second expression always true
|
|
{ 0, { First, "<|<=" }, "&&", { First, "<|<=" }, 0, MoreEqual, SecondTrue }, // (x < 5) && (x < 4) <- second expression always true
|
|
{ 0, { NA, "==" }, "&&", { NA, "!=" }, 0, NotEqual, SecondTrue }, // (x == 3) && (x != 4) <- second expression always true
|
|
{ "!!&&", { NA, "==" }, "%oror%", { NA, "!=" }, "!!&&", NotEqual, SecondTrue }, // (x == 3) || (x != 4) <- second expression always true
|
|
{ 0, { NA, "!=" }, "&&", { NA, "==" }, 0, Equal, AlwaysFalse }, // (x != 3) && (x == 3) <- expression always false
|
|
{ "!!&&", { NA, "!=" }, "%oror%", { NA, "==" }, "!!&&", Equal, AlwaysTrue }, // (x != 3) || (x == 3) <- expression always true
|
|
};
|
|
|
|
for (unsigned int i = 0; i < (sizeof(conditions) / sizeof(conditions[0])); i++) {
|
|
if (!Token::Match(op2Tok, conditions[i].op2TokStr))
|
|
continue;
|
|
|
|
if (conditions[i].before != 0 && !Token::Match(tok->previous(), conditions[i].before))
|
|
continue;
|
|
|
|
if (conditions[i].after != 0 && !Token::Match(nextTok, conditions[i].after))
|
|
continue;
|
|
|
|
if (tok->previous()->isArithmeticalOp() || nextTok->isArithmeticalOp())
|
|
continue;
|
|
|
|
std::string cond1str = var1Tok->str() + " " + (varFirst1?op1Tok->str():invertOperatorForOperandSwap(op1Tok->str())) + " " + firstConstant;
|
|
std::string cond2str = var2Tok->str() + " " + (varFirst2?op3Tok->str():invertOperatorForOperandSwap(op3Tok->str())) + " " + secondConstant;
|
|
// cond1 op cond2
|
|
bool error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, false, false,
|
|
varFirst1, varFirst2, firstConstant, secondConstant,
|
|
op1Tok, op3Tok,
|
|
conditions[i].relation);
|
|
// inv(cond1) op cond2 // invert first condition
|
|
if (!error && conditions[i].c1.position != NA)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, true, false,
|
|
!varFirst1, varFirst2, firstConstant, secondConstant,
|
|
op1Tok, op3Tok,
|
|
conditions[i].relation);
|
|
// cond1 op inv(cond2) // invert second condition
|
|
if (!error && conditions[i].c2.position != NA)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, false, true,
|
|
varFirst1, !varFirst2, firstConstant, secondConstant,
|
|
op1Tok, op3Tok,
|
|
conditions[i].relation);
|
|
// inv(cond1) op inv(cond2) // invert both conditions
|
|
if (!error && conditions[i].c1.position != NA && conditions[i].c2.position != NA)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, true, true,
|
|
!varFirst1, !varFirst2, firstConstant, secondConstant,
|
|
op1Tok, op3Tok,
|
|
conditions[i].relation);
|
|
if (!error)
|
|
std::swap(cond1str, cond2str);
|
|
// cond2 op cond1 // swap conditions
|
|
if (!error)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, false, false,
|
|
varFirst2, varFirst1, secondConstant, firstConstant,
|
|
op3Tok, op1Tok,
|
|
conditions[i].relation);
|
|
// cond2 op inv(cond1) // swap conditions; invert first condition
|
|
if (!error && conditions[i].c1.position != NA)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, true, false,
|
|
!varFirst2, varFirst1, secondConstant, firstConstant,
|
|
op3Tok, op1Tok,
|
|
conditions[i].relation);
|
|
// inv(cond2) op cond1 // swap conditions; invert second condition
|
|
if (!error && conditions[i].c2.position != NA)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, false, true,
|
|
varFirst2, !varFirst1, secondConstant, firstConstant,
|
|
op3Tok, op1Tok,
|
|
conditions[i].relation);
|
|
// inv(cond2) op inv(cond1) // swap conditions; invert both conditions
|
|
if (!error && conditions[i].c1.position != NA && conditions[i].c2.position != NA)
|
|
error = analyzeLogicOperatorCondition(conditions[i].c1, conditions[i].c2, true, true,
|
|
!varFirst2, !varFirst1, secondConstant, firstConstant,
|
|
op3Tok, op1Tok,
|
|
conditions[i].relation);
|
|
|
|
if (error) {
|
|
if (conditions[i].error == AlwaysFalse || conditions[i].error == AlwaysTrue) {
|
|
if (warning) {
|
|
const std::string text = cond1str + " " + op2Tok->str() + " " + cond2str;
|
|
incorrectLogicOperatorError(term1Tok, text, conditions[i].error == AlwaysTrue);
|
|
}
|
|
} else {
|
|
if (style) {
|
|
const std::string text = "If " + cond1str + ", the comparison " + cond2str +
|
|
" is always " + ((conditions[i].error == SecondTrue || conditions[i].error == AlwaysTrue) ? "true" : "false") + ".";
|
|
redundantConditionError(term1Tok, text);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::incorrectLogicOperatorError(const Token *tok, const std::string &condition, bool always)
|
|
{
|
|
if (always)
|
|
reportError(tok, Severity::warning, "incorrectLogicOperator",
|
|
"Logical disjunction always evaluates to true: " + condition + ".\n"
|
|
"Logical disjunction always evaluates to true: " + condition + ". "
|
|
"Are these conditions necessary? Did you intend to use && instead? Are the numbers correct? Are you comparing the correct variables?");
|
|
else
|
|
reportError(tok, Severity::warning, "incorrectLogicOperator",
|
|
"Logical conjunction always evaluates to false: " + condition + ".\n"
|
|
"Logical conjunction always evaluates to false: " + condition + ". "
|
|
"Are these conditions necessary? Did you intend to use || instead? Are the numbers correct? Are you comparing the correct variables?");
|
|
}
|
|
|
|
void CheckOther::redundantConditionError(const Token *tok, const std::string &text)
|
|
{
|
|
reportError(tok, Severity::style, "redundantCondition", "Redundant condition: " + text);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// strtol(str, 0, radix) <- radix must be 0 or 2-36
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::invalidFunctionUsage()
|
|
{
|
|
// strtol and strtoul..
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (!Token::Match(tok, "strtol|strtoul|strtoll|strtoull|wcstol|wcstoul|wcstoll|wcstoull ("))
|
|
continue;
|
|
|
|
const std::string& funcname = tok->str();
|
|
tok = tok->tokAt(2);
|
|
// Locate the third parameter of the function call..
|
|
for (int i = 0; i < 2 && tok; i++)
|
|
tok = tok->nextArgument();
|
|
|
|
if (Token::Match(tok, "%num% )")) {
|
|
const MathLib::bigint radix = MathLib::toLongNumber(tok->str());
|
|
if (!(radix == 0 || (radix >= 2 && radix <= 36))) {
|
|
dangerousUsageStrtolError(tok, funcname);
|
|
}
|
|
} else
|
|
break;
|
|
}
|
|
|
|
// sprintf|snprintf overlapping data
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
// Get variable id of target buffer..
|
|
unsigned int varid = 0;
|
|
|
|
if (Token::Match(tok, "sprintf|snprintf|swprintf ( %var% ,"))
|
|
varid = tok->tokAt(2)->varId();
|
|
|
|
else if (Token::Match(tok, "sprintf|snprintf|swprintf ( %var% . %var% ,"))
|
|
varid = tok->tokAt(4)->varId();
|
|
|
|
if (varid == 0)
|
|
continue;
|
|
|
|
// goto ","
|
|
const Token *tok2 = tok->tokAt(3);
|
|
while (tok2->str() != ",")
|
|
tok2 = tok2->next();
|
|
|
|
tok2 = tok2->next(); // Jump behind ","
|
|
|
|
if (tok->str() == "snprintf" || tok->str() == "swprintf") { // Jump over second parameter for snprintf and swprintf
|
|
tok2 = tok2->nextArgument();
|
|
if (!tok2)
|
|
continue;
|
|
}
|
|
|
|
// is any source buffer overlapping the target buffer?
|
|
do {
|
|
if (Token::Match(tok2, "%varid% [,)]", varid)) {
|
|
sprintfOverlappingDataError(tok2, tok2->str());
|
|
break;
|
|
}
|
|
} while (NULL != (tok2 = tok2->nextArgument()));
|
|
}
|
|
}
|
|
|
|
void CheckOther::dangerousUsageStrtolError(const Token *tok, const std::string& funcname)
|
|
{
|
|
reportError(tok, Severity::error, "dangerousUsageStrtol", "Invalid radix in call to " + funcname + "(). It must be 0 or 2-36.");
|
|
}
|
|
|
|
void CheckOther::sprintfOverlappingDataError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "sprintfOverlappingData",
|
|
"Undefined behavior: Variable '" + varname + "' is used as parameter and destination in s[n]printf().\n"
|
|
"The variable '" + varname + "' is used both as a parameter and as destination in "
|
|
"s[n]printf(). The origin and destination buffers overlap. Quote from glibc (C-library) "
|
|
"documentation (http://www.gnu.org/software/libc/manual/html_mono/libc.html#Formatted-Output-Functions): "
|
|
"\"If copying takes place between objects that overlap as a result of a call "
|
|
"to sprintf() or snprintf(), the results are undefined.\"");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Find consecutive return, break, continue, goto or throw statements. e.g.:
|
|
// break; break;
|
|
// Detect dead code, that follows such a statement. e.g.:
|
|
// return(0); foo();
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkUnreachableCode()
|
|
{
|
|
if (!_settings->isEnabled("style"))
|
|
return;
|
|
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
const Token* secondBreak = 0;
|
|
const Token* labelName = 0;
|
|
if (tok->str() == "(")
|
|
tok = tok->link();
|
|
else if (Token::Match(tok, "break|continue ;"))
|
|
secondBreak = tok->tokAt(2);
|
|
else if (Token::Match(tok, "[;{}:] return|throw")) {
|
|
tok = tok->next(); // tok should point to return or throw
|
|
for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next())
|
|
if (tok2->str() == ";") {
|
|
secondBreak = tok2->next();
|
|
break;
|
|
}
|
|
} else if (Token::Match(tok, "goto %any% ;")) {
|
|
secondBreak = tok->tokAt(3);
|
|
labelName = tok->next();
|
|
}
|
|
|
|
// Statements follow directly, no line between them. (#3383)
|
|
// TODO: Try to find a better way to avoid false positives due to preprocessor configurations.
|
|
bool inconclusive = secondBreak && (secondBreak->linenr()-1 > secondBreak->previous()->linenr());
|
|
|
|
if (secondBreak && (_settings->inconclusive || !inconclusive)) {
|
|
if (Token::Match(secondBreak, "continue|goto|throw") ||
|
|
(secondBreak->str() == "return" && (tok->str() == "return" || secondBreak->strAt(1) == ";"))) { // return with value after statements like throw can be necessary to make a function compile
|
|
duplicateBreakError(secondBreak, inconclusive);
|
|
tok = Token::findmatch(secondBreak, "[}:]");
|
|
} else if (secondBreak->str() == "break") { // break inside switch as second break statement should not issue a warning
|
|
if (tok->str() == "break") // If the previous was a break, too: Issue warning
|
|
duplicateBreakError(secondBreak, inconclusive);
|
|
else {
|
|
if (tok->scope()->type != Scope::eSwitch) // Check, if the enclosing scope is a switch
|
|
duplicateBreakError(secondBreak, inconclusive);
|
|
}
|
|
tok = Token::findmatch(secondBreak, "[}:]");
|
|
} else if (!Token::Match(secondBreak, "return|}|case|default") && secondBreak->strAt(1) != ":") { // TODO: No bailout for unconditional scopes
|
|
// If the goto label is followed by a loop construct in which the label is defined it's quite likely
|
|
// that the goto jump was intended to skip some code on the first loop iteration.
|
|
bool labelInFollowingLoop = false;
|
|
if (labelName && Token::Match(secondBreak, "while|do|for")) {
|
|
const Token *scope = Token::findsimplematch(secondBreak, "{");
|
|
if (scope) {
|
|
for (const Token *tokIter = scope; tokIter != scope->link() && tokIter; tokIter = tokIter->next()) {
|
|
if (Token::Match(tokIter, "[;{}] %any% :") && labelName->str() == tokIter->strAt(1)) {
|
|
labelInFollowingLoop = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (!labelInFollowingLoop)
|
|
unreachableCodeError(secondBreak, inconclusive);
|
|
tok = Token::findmatch(secondBreak, "[}:]");
|
|
} else
|
|
tok = secondBreak;
|
|
|
|
if (!tok)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::duplicateBreakError(const Token *tok, bool inconclusive)
|
|
{
|
|
reportError(tok, Severity::style, "duplicateBreak",
|
|
"Consecutive return, break, continue, goto or throw statements are unnecessary.\n"
|
|
"Consecutive return, break, continue, goto or throw statements are unnecessary. "
|
|
"The second statement can never be executed, and so should be removed.", inconclusive);
|
|
}
|
|
|
|
void CheckOther::unreachableCodeError(const Token *tok, bool inconclusive)
|
|
{
|
|
reportError(tok, Severity::style, "unreachableCode",
|
|
"Statements following return, break, continue, goto or throw will never be executed.", inconclusive);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check for unsigned divisions
|
|
//---------------------------------------------------------------------------
|
|
bool CheckOther::isUnsigned(const Variable* var) const
|
|
{
|
|
return(var && var->typeStartToken()->isUnsigned() && !var->isPointer() && !var->isArray() && _tokenizer->sizeOfType(var->typeStartToken()) >= _settings->sizeof_int);
|
|
}
|
|
bool CheckOther::isSigned(const Variable* var)
|
|
{
|
|
return(var && !var->typeStartToken()->isUnsigned() && Token::Match(var->typeEndToken(), "int|char|short|long") && !var->isPointer() && !var->isArray());
|
|
}
|
|
|
|
void CheckOther::checkUnsignedDivision()
|
|
{
|
|
bool warning = _settings->isEnabled("warning");
|
|
|
|
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
const Token* ifTok = 0;
|
|
// Check for "ivar / uvar" and "uvar / ivar"
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
|
|
if (Token::Match(tok, "[).]")) // Don't check members or casted variables
|
|
continue;
|
|
|
|
if (Token::Match(tok->next(), "%var% / %num%")) {
|
|
if (tok->strAt(3)[0] == '-' && isUnsigned(tok->next()->variable())) {
|
|
udivError(tok->next(), false);
|
|
}
|
|
} else if (Token::Match(tok->next(), "%num% / %var%")) {
|
|
if (tok->strAt(1)[0] == '-' && isUnsigned(tok->tokAt(3)->variable())) {
|
|
udivError(tok->next(), false);
|
|
}
|
|
} else if (Token::Match(tok->next(), "%var% / %var%") && _settings->inconclusive && warning && !ifTok) {
|
|
const Variable* var1 = tok->next()->variable();
|
|
const Variable* var2 = tok->tokAt(3)->variable();
|
|
if ((isUnsigned(var1) && isSigned(var2)) || (isUnsigned(var2) && isSigned(var1))) {
|
|
udivError(tok->next(), true);
|
|
}
|
|
} else if (!ifTok && Token::simpleMatch(tok, "if ("))
|
|
ifTok = tok->next()->link()->next()->link();
|
|
else if (ifTok == tok)
|
|
ifTok = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::udivError(const Token *tok, bool inconclusive)
|
|
{
|
|
if (inconclusive)
|
|
reportError(tok, Severity::warning, "udivError", "Division with signed and unsigned operators. The result might be wrong.", true);
|
|
else
|
|
reportError(tok, Severity::error, "udivError", "Unsigned division. The result will be wrong.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// memset(p, y, 0 /* bytes to fill */) <- 2nd and 3rd arguments inverted
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkMemsetZeroBytes()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::simpleMatch(tok, "memset (")) {
|
|
const Token* lastParamTok = tok->next()->link()->previous();
|
|
if (lastParamTok->str() == "0")
|
|
memsetZeroBytesError(tok, tok->strAt(2));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::memsetZeroBytesError(const Token *tok, const std::string &varname)
|
|
{
|
|
const std::string summary("memset() called to fill 0 bytes of '" + varname + "'.");
|
|
const std::string verbose(summary + " Second and third arguments might be inverted.");
|
|
reportError(tok, Severity::warning, "memsetZeroBytes", summary + "\n" + verbose);
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check scope of variables..
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkVariableScope()
|
|
{
|
|
if (!_settings->isEnabled("style"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (unsigned int i = 1; i < symbolDatabase->getVariableListSize(); i++) {
|
|
const Variable* var = symbolDatabase->getVariableFromVarId(i);
|
|
if (!var || !var->isLocal() || (!var->isPointer() && !var->typeStartToken()->isStandardType() && !var->typeStartToken()->next()->isStandardType()))
|
|
continue;
|
|
|
|
bool forHead = false; // Don't check variables declared in header of a for loop
|
|
for (const Token* tok = var->typeStartToken(); tok; tok = tok->previous()) {
|
|
if (tok->str() == "(") {
|
|
forHead = true;
|
|
break;
|
|
} else if (tok->str() == "{" || tok->str() == ";" || tok->str() == "}")
|
|
break;
|
|
}
|
|
if (forHead)
|
|
continue;
|
|
|
|
const Token* tok = var->nameToken()->next();
|
|
if (Token::Match(tok, "; %varid% = %any% ;", var->varId())) {
|
|
tok = tok->tokAt(3);
|
|
if (!tok->isNumber() && tok->type() != Token::eString && tok->type() != Token::eChar && !tok->isBoolean())
|
|
continue;
|
|
} else if ((tok->str() == "=" || tok->str() == "(") &&
|
|
((!tok->next()->isNumber() && tok->next()->type() != Token::eString && tok->next()->type() != Token::eChar && !tok->next()->isBoolean()) || tok->strAt(2) != ";"))
|
|
continue;
|
|
|
|
bool reduce = true;
|
|
bool used = false; // Don't warn about unused variables
|
|
for (; tok != var->scope()->classEnd; tok = tok->next()) {
|
|
if (tok->str() == "{" && tok->strAt(-1) != "=") {
|
|
if (used) {
|
|
bool used2 = false;
|
|
if (!checkInnerScope(tok, var, used2) || used2) {
|
|
reduce = false;
|
|
break;
|
|
}
|
|
} else if (!checkInnerScope(tok, var, used)) {
|
|
reduce = false;
|
|
break;
|
|
}
|
|
|
|
tok = tok->link();
|
|
} else if (tok->varId() == var->varId() || tok->str() == "goto") {
|
|
reduce = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (reduce && used)
|
|
variableScopeError(var->nameToken(), var->name());
|
|
}
|
|
}
|
|
|
|
bool CheckOther::checkInnerScope(const Token *tok, const Variable* var, bool& used)
|
|
{
|
|
const Scope* scope = tok->next()->scope();
|
|
bool loopVariable = scope->type == Scope::eFor || scope->type == Scope::eWhile || scope->type == Scope::eDo;
|
|
bool noContinue = true;
|
|
const Token* forHeadEnd = 0;
|
|
const Token* end = tok->link();
|
|
if (scope->type == Scope::eUnconditional && (tok->strAt(-1) == ")" || tok->previous()->isName())) // Might be an unknown macro like BOOST_FOREACH
|
|
loopVariable = true;
|
|
|
|
if (scope->type == Scope::eDo) {
|
|
end = end->linkAt(2);
|
|
} else if (loopVariable && tok->strAt(-1) == ")") {
|
|
tok = tok->linkAt(-1); // Jump to opening ( of for/while statement
|
|
} else if (scope->type == Scope::eSwitch) {
|
|
for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
|
|
if (used) {
|
|
bool used2 = false;
|
|
if (!checkInnerScope((*i)->classStart, var, used2) || used2) {
|
|
return false;
|
|
}
|
|
} else if (!checkInnerScope((*i)->classStart, var, used)) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (; tok != end; tok = tok->next()) {
|
|
if (tok->str() == "goto")
|
|
return false;
|
|
if (tok->str() == "continue")
|
|
noContinue = false;
|
|
|
|
if (Token::simpleMatch(tok, "for ("))
|
|
forHeadEnd = tok->linkAt(1);
|
|
if (tok == forHeadEnd)
|
|
forHeadEnd = 0;
|
|
|
|
if (loopVariable && noContinue && tok->scope() == scope && !forHeadEnd && scope->type != Scope::eSwitch && Token::Match(tok, "%varid% =", var->varId())) { // Assigned in outer scope.
|
|
loopVariable = false;
|
|
unsigned int indent = 0;
|
|
for (const Token* tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { // Ensure that variable isn't used on right side of =, too
|
|
if (tok2->str() == "(")
|
|
indent++;
|
|
else if (tok2->str() == ")") {
|
|
if (indent == 0)
|
|
break;
|
|
indent--;
|
|
} else if (tok2->str() == ";")
|
|
break;
|
|
else if (tok2->varId() == var->varId()) {
|
|
loopVariable = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (loopVariable && Token::Match(tok, "%varid% !!=", var->varId())) // Variable used in loop
|
|
return false;
|
|
|
|
if (Token::Match(tok, "& %varid%", var->varId())) // Taking address of variable
|
|
return false;
|
|
|
|
if (Token::Match(tok, "= %varid%", var->varId()) && (var->isArray() || var->isPointer())) // Create a copy of array/pointer. Bailout, because the memory it points to might be necessary in outer scope
|
|
return false;
|
|
|
|
if (tok->varId() == var->varId()) {
|
|
used = true;
|
|
if (scope->type == Scope::eSwitch && scope == tok->scope())
|
|
return false; // Used in outer switch scope - unsafe or impossible to reduce scope
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void CheckOther::variableScopeError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok,
|
|
Severity::style,
|
|
"variableScope",
|
|
"The scope of the variable '" + varname + "' can be reduced.\n"
|
|
"The scope of the variable '" + varname + "' can be reduced. Warning: Be careful "
|
|
"when fixing this message, especially when there are inner loops. Here is an "
|
|
"example where cppcheck will write that the scope for 'i' can be reduced:\n"
|
|
"void f(int x)\n"
|
|
"{\n"
|
|
" int i = 0;\n"
|
|
" if (x) {\n"
|
|
" // it's safe to move 'int i = 0;' here\n"
|
|
" for (int n = 0; n < 10; ++n) {\n"
|
|
" // it is possible but not safe to move 'int i = 0;' here\n"
|
|
" do_something(&i);\n"
|
|
" }\n"
|
|
" }\n"
|
|
"}\n"
|
|
"When you see this message it is always safe to reduce the variable scope 1 level.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check for constant function parameters
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkConstantFunctionParameter()
|
|
{
|
|
if (!_settings->isEnabled("performance") || _tokenizer->isC())
|
|
return;
|
|
|
|
const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (unsigned int i = 1; i < symbolDatabase->getVariableListSize(); i++) {
|
|
const Variable* var = symbolDatabase->getVariableFromVarId(i);
|
|
if (!var || !var->isArgument() || !var->isClass() || !var->isConst() || var->isPointer() || var->isArray() || var->isReference())
|
|
continue;
|
|
|
|
const Token* const tok = var->typeStartToken();
|
|
// TODO: False negatives. This pattern only checks for string.
|
|
// Investigate if there are other classes in the std
|
|
// namespace and add them to the pattern. There are
|
|
// streams for example (however it seems strange with
|
|
// const stream parameter).
|
|
if (Token::Match(tok, "std :: string|wstring")) {
|
|
passedByValueError(tok, var->name());
|
|
} else if (Token::Match(tok, "std :: %type% <") && !Token::simpleMatch(tok->linkAt(3), "> ::")) {
|
|
passedByValueError(tok, var->name());
|
|
} else if (var->type()) { // Check if type is a struct or class.
|
|
passedByValueError(tok, var->name());
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::passedByValueError(const Token *tok, const std::string &parname)
|
|
{
|
|
reportError(tok, Severity::performance, "passedByValue",
|
|
"Function parameter '" + parname + "' should be passed by reference.\n"
|
|
"Parameter '" + parname + "' is passed by value. It could be passed "
|
|
"as a (const) reference which is usually faster and recommended in C++.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check usage of char variables..
|
|
//---------------------------------------------------------------------------
|
|
static bool isChar(const Variable* var)
|
|
{
|
|
return(var && !var->isPointer() && !var->isArray() && var->typeStartToken()->str() == "char");
|
|
}
|
|
|
|
static bool isSignedChar(const Variable* var)
|
|
{
|
|
return(isChar(var) && !var->typeStartToken()->isUnsigned());
|
|
}
|
|
|
|
void CheckOther::checkCharVariable()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
|
|
if ((tok->str() != ".") && Token::Match(tok->next(), "%var% [ %var% ]")) {
|
|
const Variable* arrayvar = tok->next()->variable();
|
|
const Variable* indexvar = tok->tokAt(3)->variable();
|
|
const MathLib::bigint arraysize = (arrayvar && arrayvar->isArray()) ? arrayvar->dimension(0U) : 0;
|
|
if (isSignedChar(indexvar) && arraysize > 0x80)
|
|
charArrayIndexError(tok->next());
|
|
}
|
|
|
|
else if (Token::Match(tok, "[;{}] %var% = %any% [&^|] %any% ;")) {
|
|
// is a char variable used in the calculation?
|
|
if (!isSignedChar(tok->tokAt(3)->variable()) &&
|
|
!isSignedChar(tok->tokAt(5)->variable()))
|
|
continue;
|
|
|
|
// it's ok with a bitwise and where the other operand is 0xff or less..
|
|
if (tok->strAt(4) == "&") {
|
|
if (tok->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok->strAt(3)))
|
|
continue;
|
|
if (tok->tokAt(5)->isNumber() && MathLib::isGreater("0x100", tok->strAt(5)))
|
|
continue;
|
|
}
|
|
|
|
// is the result stored in a short|int|long?
|
|
const Variable *var = tok->next()->variable();
|
|
if (var && Token::Match(var->typeStartToken(), "short|int|long") && !var->isPointer() && !var->isArray())
|
|
charBitOpError(tok->tokAt(4)); // This is an error..
|
|
}
|
|
|
|
else if (Token::Match(tok, "[;{}] %var% = %any% [&^|] ( * %var% ) ;")) {
|
|
const Variable* var = tok->tokAt(7)->variable();
|
|
if (!var || !var->isPointer() || var->typeStartToken()->str() != "char" || var->typeStartToken()->isUnsigned())
|
|
continue;
|
|
// it's ok with a bitwise and where the other operand is 0xff or less..
|
|
if (tok->strAt(4) == "&" && tok->tokAt(3)->isNumber() && MathLib::isGreater("0x100", tok->strAt(3)))
|
|
continue;
|
|
|
|
// is the result stored in a short|int|long?
|
|
var = tok->next()->variable();
|
|
if (var && Token::Match(var->typeStartToken(), "short|int|long") && !var->isPointer() && !var->isArray())
|
|
charBitOpError(tok->tokAt(4)); // This is an error..
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::charArrayIndexError(const Token *tok)
|
|
{
|
|
reportError(tok,
|
|
Severity::warning,
|
|
"charArrayIndex",
|
|
"Signed 'char' type used as array index.\n"
|
|
"Signed 'char' type used as array index. If the value "
|
|
"can be greater than 127 there will be a buffer underflow "
|
|
"because of sign extension.");
|
|
}
|
|
|
|
void CheckOther::charBitOpError(const Token *tok)
|
|
{
|
|
reportError(tok,
|
|
Severity::warning,
|
|
"charBitOp",
|
|
"When using 'char' variables in bit operations, sign extension can generate unexpected results.\n"
|
|
"When using 'char' variables in bit operations, sign extension can generate unexpected results. For example:\n"
|
|
" char c = 0x80;\n"
|
|
" int i = 0 | c;\n"
|
|
" if (i & 0x8000)\n"
|
|
" printf(\"not expected\");\n"
|
|
"The \"not expected\" will be printed on the screen.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Incomplete statement..
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkIncompleteStatement()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (tok->str() == "(") {
|
|
tok = tok->link();
|
|
if (Token::simpleMatch(tok, ") {") && Token::simpleMatch(tok->next()->link(), "} ;"))
|
|
tok = tok->next()->link();
|
|
}
|
|
|
|
else if (Token::simpleMatch(tok, "= {"))
|
|
tok = tok->next()->link();
|
|
|
|
// C++11 struct/array initialization in initializer list
|
|
else if (tok->str() == "{" && Token::Match(tok->tokAt(-2), ",|: %var%") && Token::Match(tok->link(), "} [,{]"))
|
|
tok = tok->link();
|
|
|
|
// C++11 vector initialization / return { .. }
|
|
else if (Token::Match(tok,"> %var% {") || Token::Match(tok, "[;{}] return {"))
|
|
tok = tok->linkAt(2);
|
|
|
|
else if (Token::Match(tok, "[;{}] %str%") || Token::Match(tok, "[;{}] %num%")) {
|
|
// No warning if numeric constant is followed by a "." or ","
|
|
if (Token::Match(tok->next(), "%num% [,.]"))
|
|
continue;
|
|
|
|
// bailout if there is a "? :" in this statement
|
|
bool bailout = false;
|
|
for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
|
|
if (tok2->str() == "?")
|
|
bailout = true;
|
|
else if (tok2->str() == ";")
|
|
break;
|
|
}
|
|
if (bailout)
|
|
continue;
|
|
|
|
constStatementError(tok->next(), tok->next()->isNumber() ? "numeric" : "string");
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::constStatementError(const Token *tok, const std::string &type)
|
|
{
|
|
reportError(tok, Severity::warning, "constStatement", "Redundant code: Found a statement that begins with " + type + " constant.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// str plus char
|
|
//---------------------------------------------------------------------------
|
|
|
|
void CheckOther::strPlusChar()
|
|
{
|
|
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "[=(] %str% + %any%")) {
|
|
// char constant..
|
|
if (tok->tokAt(3)->type() == Token::eChar)
|
|
strPlusCharError(tok->next());
|
|
|
|
// char variable..
|
|
if (isChar(tok->tokAt(3)->variable()))
|
|
strPlusCharError(tok->next());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::strPlusCharError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::error, "strPlusChar", "Unusual pointer arithmetic. A value of type 'char' is added to a string literal.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkZeroDivision()
|
|
{
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (Token::Match(tok, "[/%] %num%") &&
|
|
MathLib::isInt(tok->next()->str()) &&
|
|
MathLib::toLongNumber(tok->next()->str()) == 0L) {
|
|
zerodivError(tok);
|
|
} else if (Token::Match(tok, "div|ldiv|lldiv|imaxdiv ( %num% , %num% )") &&
|
|
MathLib::isInt(tok->strAt(4)) &&
|
|
MathLib::toLongNumber(tok->strAt(4)) == 0L) {
|
|
zerodivError(tok);
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::zerodivError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::error, "zerodiv", "Division by zero.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkMathFunctions()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (tok->varId())
|
|
continue;
|
|
if (Token::Match(tok, "log|log10 ( %num% )")) {
|
|
bool isNegative = MathLib::isNegative(tok->strAt(2));
|
|
bool isInt = MathLib::isInt(tok->strAt(2));
|
|
bool isFloat = MathLib::isFloat(tok->strAt(2));
|
|
if (isNegative && isInt && MathLib::toLongNumber(tok->strAt(2)) <= 0) {
|
|
mathfunctionCallError(tok); // case log(-2)
|
|
} else if (isNegative && isFloat && MathLib::toDoubleNumber(tok->strAt(2)) <= 0.) {
|
|
mathfunctionCallError(tok); // case log(-2.0)
|
|
} else if (!isNegative && isFloat && MathLib::toDoubleNumber(tok->strAt(2)) <= 0.) {
|
|
mathfunctionCallError(tok); // case log(0.0)
|
|
} else if (!isNegative && isInt && MathLib::toLongNumber(tok->strAt(2)) <= 0) {
|
|
mathfunctionCallError(tok); // case log(0)
|
|
}
|
|
}
|
|
|
|
// acos( x ), asin( x ) where x is defined for interval [-1,+1], but not beyond
|
|
else if (Token::Match(tok, "acos|asin ( %num% )") &&
|
|
std::fabs(MathLib::toDoubleNumber(tok->strAt(2))) > 1.0) {
|
|
mathfunctionCallError(tok);
|
|
}
|
|
// sqrt( x ): if x is negative the result is undefined
|
|
else if (Token::Match(tok, "sqrt|sqrtf|sqrtl ( %num% )") &&
|
|
MathLib::isNegative(tok->strAt(2))) {
|
|
mathfunctionCallError(tok);
|
|
}
|
|
// atan2 ( x , y): x and y can not be zero, because this is mathematically not defined
|
|
else if (Token::Match(tok, "atan2 ( %num% , %num% )") &&
|
|
MathLib::isNullValue(tok->strAt(2)) &&
|
|
MathLib::isNullValue(tok->strAt(4))) {
|
|
mathfunctionCallError(tok, 2);
|
|
}
|
|
// fmod ( x , y) If y is zero, then either a range error will occur or the function will return zero (implementation-defined).
|
|
else if (Token::Match(tok, "fmod ( %any%")) {
|
|
const Token* nextArg = tok->tokAt(2)->nextArgument();
|
|
if (nextArg && nextArg->isNumber() && MathLib::isNullValue(nextArg->str()))
|
|
mathfunctionCallError(tok, 2);
|
|
}
|
|
// pow ( x , y) If x is zero, and y is negative --> division by zero
|
|
else if (Token::Match(tok, "pow ( %num% , %num% )") &&
|
|
MathLib::isNullValue(tok->strAt(2)) &&
|
|
MathLib::isNegative(tok->strAt(4))) {
|
|
mathfunctionCallError(tok, 2);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::mathfunctionCallError(const Token *tok, const unsigned int numParam)
|
|
{
|
|
if (tok) {
|
|
if (numParam == 1)
|
|
reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->strAt(2) + " to " + tok->str() + "() leads to undefined result.");
|
|
else if (numParam == 2)
|
|
reportError(tok, Severity::error, "wrongmathcall", "Passing values " + tok->strAt(2) + " and " + tok->strAt(4) + " to " + tok->str() + "() leads to undefined result.");
|
|
} else
|
|
reportError(tok, Severity::error, "wrongmathcall", "Passing value '#' to #() leads to undefined result.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkCCTypeFunctions()
|
|
{
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (tok->varId() == 0 &&
|
|
Token::Match(tok, "isalnum|isalpha|iscntrl|isdigit|isgraph|islower|isprint|ispunct|isspace|isupper|isxdigit ( %num% ,|)") &&
|
|
MathLib::isNegative(tok->strAt(2))) {
|
|
cctypefunctionCallError(tok, tok->str(), tok->strAt(2));
|
|
}
|
|
}
|
|
}
|
|
void CheckOther::cctypefunctionCallError(const Token *tok, const std::string &functionName, const std::string &value)
|
|
{
|
|
reportError(tok, Severity::error, "wrongcctypecall", "Passing value " + value + " to " + functionName + "() causes undefined behavior which may lead to a crash.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkMisusedScopedObject()
|
|
{
|
|
// Skip this check for .c files
|
|
if (_tokenizer->isC()) {
|
|
return;
|
|
}
|
|
|
|
const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token *tok = scope->classStart; tok && tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "[;{}] %var% (")
|
|
&& Token::simpleMatch(tok->linkAt(2), ") ;")
|
|
&& symbolDatabase->isClassOrStruct(tok->next()->str())
|
|
&& !tok->next()->function()) {
|
|
tok = tok->next();
|
|
misusedScopeObjectError(tok, tok->str());
|
|
tok = tok->next();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::misusedScopeObjectError(const Token *tok, const std::string& varname)
|
|
{
|
|
reportError(tok, Severity::error,
|
|
"unusedScopedObject", "Instance of '" + varname + "' object is destroyed immediately.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkIncorrectStringCompare()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
// skip "assert(str && ..)" and "assert(.. && str)"
|
|
if (Token::Match(tok, "%var% (") &&
|
|
(Token::Match(tok->tokAt(2), "%str% &&") || Token::Match(tok->next()->link()->tokAt(-2), "&& %str% )")) &&
|
|
(tok->str().find("assert")+6U==tok->str().size() || tok->str().find("ASSERT")+6U==tok->str().size()))
|
|
tok = tok->next()->link();
|
|
|
|
if (Token::simpleMatch(tok, ". substr (") && Token::Match(tok->tokAt(3)->nextArgument(), "%num% )")) {
|
|
MathLib::bigint clen = MathLib::toLongNumber(tok->linkAt(2)->strAt(-1));
|
|
const Token* begin = tok->previous();
|
|
for (;;) { // Find start of statement
|
|
while (begin->link() && Token::Match(begin, "]|)|>"))
|
|
begin = begin->link()->previous();
|
|
if (Token::Match(begin->previous(), ".|::"))
|
|
begin = begin->tokAt(-2);
|
|
else
|
|
break;
|
|
}
|
|
begin = begin->previous();
|
|
const Token* end = tok->linkAt(2)->next();
|
|
if (Token::Match(begin->previous(), "%str% ==|!=") && begin->strAt(-2) != "+") {
|
|
std::size_t slen = Token::getStrLength(begin->previous());
|
|
if (clen != (int)slen) {
|
|
incorrectStringCompareError(tok->next(), "substr", begin->strAt(-1));
|
|
}
|
|
} else if (Token::Match(end, "==|!= %str% !!+")) {
|
|
std::size_t slen = Token::getStrLength(end->next());
|
|
if (clen != (int)slen) {
|
|
incorrectStringCompareError(tok->next(), "substr", end->strAt(1));
|
|
}
|
|
}
|
|
} else if (Token::Match(tok, "&&|%oror%|( %str% &&|%oror%|)") && !Token::Match(tok, "( %str% )")) {
|
|
incorrectStringBooleanError(tok->next(), tok->strAt(1));
|
|
} else if (Token::Match(tok, "if|while ( %str% )")) {
|
|
incorrectStringBooleanError(tok->tokAt(2), tok->strAt(2));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::incorrectStringCompareError(const Token *tok, const std::string& func, const std::string &string)
|
|
{
|
|
reportError(tok, Severity::warning, "incorrectStringCompare", "String literal " + string + " doesn't match length argument for " + func + "().");
|
|
}
|
|
|
|
void CheckOther::incorrectStringBooleanError(const Token *tok, const std::string& string)
|
|
{
|
|
reportError(tok, Severity::warning, "incorrectStringBooleanError", "Conversion of string literal " + string + " to bool always evaluates to true.");
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// check for duplicate expressions in if statements
|
|
// if (a) { } else if (a) { }
|
|
//-----------------------------------------------------------------------------
|
|
|
|
static bool expressionHasSideEffects(const Token *first, const Token *last)
|
|
{
|
|
for (const Token *tok = first; tok != last->next(); tok = tok->next()) {
|
|
// check for assignment
|
|
if (tok->isAssignmentOp())
|
|
return true;
|
|
|
|
// check for inc/dec
|
|
else if (tok->type() == Token::eIncDecOp)
|
|
return true;
|
|
|
|
// check for function call
|
|
else if (Token::Match(tok, "%var% (") &&
|
|
!(Token::Match(tok, "c_str|string") || tok->isStandardType()))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
void CheckOther::checkDuplicateIf()
|
|
{
|
|
if (!_settings->isEnabled("style"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (std::list<Scope>::const_iterator scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
|
|
const Token* const tok = scope->classDef;
|
|
// only check if statements
|
|
if (scope->type != Scope::eIf || !tok)
|
|
continue;
|
|
|
|
std::map<std::string, const Token*> expressionMap;
|
|
|
|
// get the expression from the token stream
|
|
std::string expression = tok->tokAt(2)->stringifyList(tok->next()->link());
|
|
|
|
// save the expression and its location
|
|
expressionMap.insert(std::make_pair(expression, tok));
|
|
|
|
// find the next else if (...) statement
|
|
const Token *tok1 = scope->classEnd;
|
|
|
|
// check all the else if (...) statements
|
|
while ((Token::simpleMatch(tok1, "} else if (") &&
|
|
Token::simpleMatch(tok1->linkAt(3), ") {")) ||
|
|
(Token::simpleMatch(tok1, "} else { if (") &&
|
|
Token::simpleMatch(tok1->linkAt(4), ") {"))) {
|
|
int conditionIndex=(tok1->strAt(3)=="(") ? 3 : 4;
|
|
// get the expression from the token stream
|
|
expression = tok1->tokAt(conditionIndex+1)->stringifyList(tok1->linkAt(conditionIndex));
|
|
|
|
// try to look up the expression to check for duplicates
|
|
std::map<std::string, const Token *>::iterator it = expressionMap.find(expression);
|
|
|
|
// found a duplicate
|
|
if (it != expressionMap.end()) {
|
|
// check for expressions that have side effects and ignore them
|
|
if (!expressionHasSideEffects(tok1->tokAt(conditionIndex+1), tok1->linkAt(conditionIndex)->previous()))
|
|
duplicateIfError(it->second, tok1->next());
|
|
}
|
|
|
|
// not a duplicate expression so save it and its location
|
|
else
|
|
expressionMap.insert(std::make_pair(expression, tok1->next()));
|
|
|
|
// find the next else if (...) statement
|
|
tok1 = tok1->linkAt(conditionIndex)->next()->link();
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::duplicateIfError(const Token *tok1, const Token *tok2)
|
|
{
|
|
std::list<const Token *> toks;
|
|
toks.push_back(tok2);
|
|
toks.push_back(tok1);
|
|
|
|
reportError(toks, Severity::style, "duplicateIf", "Duplicate conditions in 'if' and related 'else if'.\n"
|
|
"Duplicate conditions in 'if' and related 'else if'. This is suspicious and might indicate "
|
|
"a cut and paste or logic error. Please examine this code carefully to determine "
|
|
"if it is correct.");
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// check for duplicate code in if and else branches
|
|
// if (a) { b = true; } else { b = true; }
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::checkDuplicateBranch()
|
|
{
|
|
if (!_settings->isEnabled("style"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
std::list<Scope>::const_iterator scope;
|
|
|
|
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
|
|
if (scope->type != Scope::eIf && scope->type != Scope::eElseIf)
|
|
continue;
|
|
|
|
// check all the code in the function for if (..) else
|
|
if (Token::simpleMatch(scope->classEnd, "} else {")) {
|
|
// Make sure there are no macros (different macros might be expanded
|
|
// to the same code)
|
|
bool macro = false;
|
|
for (const Token *tok = scope->classStart; tok != scope->classEnd->linkAt(2); tok = tok->next()) {
|
|
if (tok->isExpandedMacro()) {
|
|
macro = true;
|
|
break;
|
|
}
|
|
}
|
|
if (macro)
|
|
continue;
|
|
|
|
// save if branch code
|
|
std::string branch1 = scope->classStart->next()->stringifyList(scope->classEnd);
|
|
|
|
// save else branch code
|
|
std::string branch2 = scope->classEnd->tokAt(3)->stringifyList(scope->classEnd->linkAt(2));
|
|
|
|
// check for duplicates
|
|
if (branch1 == branch2)
|
|
duplicateBranchError(scope->classDef, scope->classEnd->next());
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::duplicateBranchError(const Token *tok1, const Token *tok2)
|
|
{
|
|
std::list<const Token *> toks;
|
|
toks.push_back(tok2);
|
|
toks.push_back(tok1);
|
|
|
|
reportError(toks, Severity::style, "duplicateBranch", "Found duplicate branches for 'if' and 'else'.\n"
|
|
"Finding the same code in an 'if' and related 'else' branch is suspicious and "
|
|
"might indicate a cut and paste or logic error. Please examine this code "
|
|
"carefully to determine if it is correct.");
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Check for a free() of an invalid address
|
|
// char* p = malloc(100);
|
|
// free(p + 10);
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::checkInvalidFree()
|
|
{
|
|
std::map<unsigned int, bool> allocatedVariables;
|
|
for (const Token* tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
|
|
// Keep track of which variables were assigned addresses to newly-allocated memory
|
|
if (Token::Match(tok, "%var% = malloc|g_malloc|new")) {
|
|
allocatedVariables.insert(std::make_pair(tok->varId(), false));
|
|
}
|
|
|
|
// If a previously-allocated pointer is incremented or decremented, any subsequent
|
|
// free involving pointer arithmetic may or may not be invalid, so we should only
|
|
// report an inconclusive result.
|
|
else if (Token::Match(tok, "%var% = %var% +|-") &&
|
|
tok->varId() == tok->tokAt(2)->varId() &&
|
|
allocatedVariables.find(tok->varId()) != allocatedVariables.end()) {
|
|
if (_settings->inconclusive)
|
|
allocatedVariables[tok->varId()] = true;
|
|
else
|
|
allocatedVariables.erase(tok->varId());
|
|
}
|
|
|
|
// If a previously-allocated pointer is assigned a completely new value,
|
|
// we can't know if any subsequent free() on that pointer is valid or not.
|
|
else if (Token::Match(tok, "%var% = ")) {
|
|
allocatedVariables.erase(tok->varId());
|
|
}
|
|
|
|
// If a variable that was previously assigned a newly-allocated memory location is
|
|
// added or subtracted from when used to free the memory, report an error.
|
|
else if (Token::Match(tok, "free|g_free|delete ( %any% +|- %any%") ||
|
|
Token::Match(tok, "delete [ ] ( %any% +|- %any%") ||
|
|
Token::Match(tok, "delete %any% +|- %any%")) {
|
|
|
|
const int varIdx = tok->strAt(1) == "(" ? 2 :
|
|
tok->strAt(3) == "(" ? 4 : 1;
|
|
const unsigned int var1 = tok->tokAt(varIdx)->varId();
|
|
const unsigned int var2 = tok->tokAt(varIdx + 2)->varId();
|
|
const std::map<unsigned int, bool>::iterator alloc1 = allocatedVariables.find(var1);
|
|
const std::map<unsigned int, bool>::iterator alloc2 = allocatedVariables.find(var2);
|
|
if (alloc1 != allocatedVariables.end()) {
|
|
invalidFreeError(tok, alloc1->second);
|
|
} else if (alloc2 != allocatedVariables.end()) {
|
|
invalidFreeError(tok, alloc2->second);
|
|
}
|
|
}
|
|
|
|
// If the previously-allocated variable is passed in to another function
|
|
// as a parameter, it might be modified, so we shouldn't report an error
|
|
// if it is later used to free memory
|
|
else if (Token::Match(tok, "%var% (")) {
|
|
const Token* tok2 = Token::findmatch(tok->next(), "%var%", tok->linkAt(1));
|
|
while (tok2 != NULL) {
|
|
allocatedVariables.erase(tok2->varId());
|
|
tok2 = Token::findmatch(tok2->next(), "%var%", tok->linkAt(1));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::invalidFreeError(const Token *tok, bool inconclusive)
|
|
{
|
|
reportError(tok, Severity::error, "invalidFree", "Invalid memory address freed.", inconclusive);
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Check for double free
|
|
// free(p); free(p);
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::checkDoubleFree()
|
|
{
|
|
std::set<unsigned int> freedVariables;
|
|
std::set<unsigned int> closeDirVariables;
|
|
|
|
for (const Token* tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
// Keep track of any variables passed to "free()", "g_free()" or "closedir()",
|
|
// and report an error if the same variable is passed twice.
|
|
if (Token::Match(tok, "free|g_free|closedir ( %var% )")) {
|
|
unsigned int var = tok->tokAt(2)->varId();
|
|
if (var) {
|
|
if (Token::Match(tok, "free|g_free")) {
|
|
if (freedVariables.find(var) != freedVariables.end())
|
|
doubleFreeError(tok, tok->strAt(2));
|
|
else
|
|
freedVariables.insert(var);
|
|
} else if (tok->str() == "closedir") {
|
|
if (closeDirVariables.find(var) != closeDirVariables.end())
|
|
doubleCloseDirError(tok, tok->strAt(2));
|
|
else
|
|
closeDirVariables.insert(var);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Keep track of any variables operated on by "delete" or "delete[]"
|
|
// and report an error if the same variable is delete'd twice.
|
|
else if (Token::Match(tok, "delete %var% ;") || Token::Match(tok, "delete [ ] %var% ;")) {
|
|
int varIdx = (tok->strAt(1) == "[") ? 3 : 1;
|
|
unsigned int var = tok->tokAt(varIdx)->varId();
|
|
if (var) {
|
|
if (freedVariables.find(var) != freedVariables.end())
|
|
doubleFreeError(tok, tok->strAt(varIdx));
|
|
else
|
|
freedVariables.insert(var);
|
|
}
|
|
}
|
|
|
|
// If this scope doesn't return, clear the set of previously freed variables
|
|
else if (tok->str() == "}" && _tokenizer->IsScopeNoReturn(tok)) {
|
|
freedVariables.clear();
|
|
closeDirVariables.clear();
|
|
}
|
|
|
|
// If this scope is a "for" or "while" loop that contains "break" or "continue",
|
|
// give up on trying to figure out the flow of execution and just clear the set
|
|
// of previously freed variables.
|
|
// TODO: There are false negatives. This bailout is only needed when the
|
|
// loop will exit without free()'ing the memory on the last iteration.
|
|
else if (tok->str() == "}" && tok->link() && tok->link()->previous() &&
|
|
tok->link()->linkAt(-1) &&
|
|
Token::Match(tok->link()->linkAt(-1)->previous(), "while|for") &&
|
|
Token::findmatch(tok->link()->linkAt(-1), "break|continue ;", tok) != NULL) {
|
|
freedVariables.clear();
|
|
closeDirVariables.clear();
|
|
}
|
|
|
|
// If a variable is passed to a function, remove it from the set of previously freed variables
|
|
else if (Token::Match(tok, "%var% (") && !Token::Match(tok, "printf|sprintf|snprintf|fprintf|wprintf|swprintf|fwprintf")) {
|
|
|
|
// If this is a new function definition, clear all variables
|
|
if (Token::simpleMatch(tok->next()->link(), ") {")) {
|
|
freedVariables.clear();
|
|
closeDirVariables.clear();
|
|
}
|
|
// If it is a function call, then clear those variables in its argument list
|
|
else if (Token::simpleMatch(tok->next()->link(), ") ;")) {
|
|
for (const Token* tok2 = tok->tokAt(2); tok2 != tok->linkAt(1); tok2 = tok2->next()) {
|
|
if (tok2->varId()) {
|
|
unsigned int var = tok2->varId();
|
|
freedVariables.erase(var);
|
|
closeDirVariables.erase(var);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// If a pointer is assigned a new value, remove it from the set of previously freed variables
|
|
else if (Token::Match(tok, "%var% =")) {
|
|
unsigned int var = tok->varId();
|
|
if (var) {
|
|
freedVariables.erase(var);
|
|
closeDirVariables.erase(var);
|
|
}
|
|
}
|
|
|
|
// Any control statements in-between delete, free() or closedir() statements
|
|
// makes it unclear whether any subsequent statements would be redundant.
|
|
if (Token::Match(tok, "if|else|for|while|break|continue|goto|return|throw|switch")) {
|
|
freedVariables.clear();
|
|
closeDirVariables.clear();
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::doubleFreeError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "doubleFree", "Memory pointed to by '" + varname +"' is freed twice.");
|
|
}
|
|
|
|
void CheckOther::doubleCloseDirError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::error, "doubleCloseDir", "Directory handle '" + varname +"' closed twice.");
|
|
}
|
|
|
|
namespace {
|
|
struct ExpressionTokens {
|
|
const Token *start;
|
|
const Token *end;
|
|
int count;
|
|
bool inconclusiveFunction;
|
|
ExpressionTokens(const Token *s, const Token *e): start(s), end(e), count(1), inconclusiveFunction(false) {}
|
|
};
|
|
|
|
struct FuncFilter {
|
|
FuncFilter(const Scope *scope, const Token *tok): _scope(scope), _tok(tok) {}
|
|
|
|
bool operator()(const Function* func) const {
|
|
bool matchingFunc = func->type == Function::eFunction &&
|
|
_tok->str() == func->token->str();
|
|
// either a class function, or a global function with the same name
|
|
return (_scope && _scope == func->nestedIn && matchingFunc) ||
|
|
(!_scope && matchingFunc);
|
|
}
|
|
const Scope *_scope;
|
|
const Token *_tok;
|
|
};
|
|
|
|
bool inconclusiveFunctionCall(const std::list<const Function*> &constFunctions,
|
|
const ExpressionTokens &tokens)
|
|
{
|
|
const Token *start = tokens.start;
|
|
const Token *end = tokens.end;
|
|
// look for function calls between start and end...
|
|
for (const Token *tok = start; tok && tok != end; tok = tok->next()) {
|
|
if (tok != start && tok->str() == "(") {
|
|
// go back to find the function call.
|
|
const Token *prev = tok->previous();
|
|
if (!prev)
|
|
continue;
|
|
if (prev->str() == ">") {
|
|
// ignore template functions like boo<double>()
|
|
return true;
|
|
}
|
|
if (prev->isName()) {
|
|
const Variable *v = 0;
|
|
if (Token::Match(prev->tokAt(-2), "%var% .")) {
|
|
const Token *scope = prev->tokAt(-2);
|
|
v = scope->variable();
|
|
}
|
|
// hard coded list of safe, no-side-effect functions
|
|
if (v == 0 && Token::Match(prev, "strcmp|strncmp|strlen|wcscmp|wcsncmp|wcslen|memcmp|strcasecmp|strncasecmp"))
|
|
return false;
|
|
std::list<const Function*>::const_iterator it = std::find_if(constFunctions.begin(),
|
|
constFunctions.end(),
|
|
FuncFilter(v ? v->typeScope(): 0, prev));
|
|
if (it == constFunctions.end())
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
class Expressions {
|
|
public:
|
|
Expressions(const std::list<const Function*> &constFunctions)
|
|
: _start(0),
|
|
_lastTokens(0),
|
|
_constFunctions(constFunctions) { }
|
|
|
|
void endExpr(const Token *end) {
|
|
const std::string &e = _expression.str();
|
|
if (!e.empty()) {
|
|
std::map<std::string, ExpressionTokens>::iterator it = _expressions.find(e);
|
|
bool lastInconclusive = _lastTokens && _lastTokens->inconclusiveFunction;
|
|
if (it == _expressions.end()) {
|
|
ExpressionTokens exprTokens(_start, end);
|
|
exprTokens.inconclusiveFunction = lastInconclusive || inconclusiveFunctionCall(
|
|
_constFunctions, exprTokens);
|
|
_expressions.insert(std::make_pair(e, exprTokens));
|
|
_lastTokens = &_expressions.find(e)->second;
|
|
} else {
|
|
ExpressionTokens &expr = it->second;
|
|
expr.count += 1;
|
|
expr.inconclusiveFunction = expr.inconclusiveFunction || lastInconclusive;
|
|
_lastTokens = &expr;
|
|
}
|
|
}
|
|
_expression.str("");
|
|
_start = 0;
|
|
}
|
|
|
|
void append(const Token *tok) {
|
|
if (!_start)
|
|
_start = tok;
|
|
_expression << tok->str();
|
|
}
|
|
|
|
std::map<std::string,ExpressionTokens> &getMap() {
|
|
return _expressions;
|
|
}
|
|
|
|
private:
|
|
std::map<std::string, ExpressionTokens> _expressions;
|
|
std::ostringstream _expression;
|
|
const Token *_start;
|
|
ExpressionTokens *_lastTokens;
|
|
const std::list<const Function*> &_constFunctions;
|
|
};
|
|
|
|
bool notconst(const Function* func)
|
|
{
|
|
return !func->isConst;
|
|
}
|
|
|
|
void getConstFunctions(const SymbolDatabase *symbolDatabase, std::list<const Function*> &constFunctions)
|
|
{
|
|
std::list<Scope>::const_iterator scope;
|
|
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
|
|
std::list<Function>::const_iterator func;
|
|
// only add const functions that do not have a non-const overloaded version
|
|
// since it is pretty much impossible to tell which is being called.
|
|
typedef std::map<std::string, std::list<const Function*> > StringFunctionMap;
|
|
StringFunctionMap functionsByName;
|
|
for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
|
|
functionsByName[func->tokenDef->str()].push_back(&*func);
|
|
}
|
|
for (StringFunctionMap::iterator it = functionsByName.begin();
|
|
it != functionsByName.end(); ++it) {
|
|
std::list<const Function*>::const_iterator nc = std::find_if(it->second.begin(), it->second.end(), notconst);
|
|
if (nc == it->second.end()) {
|
|
// ok to add all of them
|
|
constFunctions.splice(constFunctions.end(), it->second);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
void CheckOther::checkExpressionRange(const std::list<const Function*> &constFunctions,
|
|
const Token *start,
|
|
const Token *end,
|
|
const std::string &toCheck)
|
|
{
|
|
if (!start || !end)
|
|
return;
|
|
Expressions expressions(constFunctions);
|
|
std::string opName;
|
|
int level = 0;
|
|
for (const Token *tok = start->next(); tok && tok != end; tok = tok->next()) {
|
|
if (tok->str() == ")")
|
|
level--;
|
|
else if (tok->str() == "(")
|
|
level++;
|
|
|
|
if (level == 0 && Token::Match(tok, toCheck.c_str())) {
|
|
opName = tok->str();
|
|
expressions.endExpr(tok);
|
|
} else {
|
|
expressions.append(tok);
|
|
}
|
|
}
|
|
expressions.endExpr(end);
|
|
std::map<std::string,ExpressionTokens>::const_iterator it = expressions.getMap().begin();
|
|
for (; it != expressions.getMap().end(); ++it) {
|
|
// check expression..
|
|
bool valid = true;
|
|
unsigned int parentheses = 0; // ()
|
|
unsigned int brackets = 0; // []
|
|
|
|
// taking address?
|
|
if (Token::Match(it->second.end->previous(), "%op% &")) {
|
|
continue;
|
|
}
|
|
|
|
for (const Token *tok = it->second.start; tok && tok != it->second.end; tok = tok->next()) {
|
|
if (tok->str() == "(") {
|
|
++parentheses;
|
|
} else if (tok->str() == ")") {
|
|
if (parentheses == 0) {
|
|
valid = false;
|
|
break;
|
|
}
|
|
--parentheses;
|
|
} else if (tok->str() == "[") {
|
|
++brackets;
|
|
} else if (tok->str() == "]") {
|
|
if (brackets == 0) {
|
|
valid = false;
|
|
break;
|
|
}
|
|
--brackets;
|
|
} else if (tok->type() == Token::eIncDecOp) {
|
|
valid = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!valid || parentheses!=0 || brackets!=0)
|
|
continue;
|
|
|
|
const ExpressionTokens &expr = it->second;
|
|
if (expr.count > 1 && !expr.inconclusiveFunction) {
|
|
duplicateExpressionError(expr.start, expr.start, opName);
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::complexDuplicateExpressionCheck(const std::list<const Function*> &constFunctions,
|
|
const Token *classStart,
|
|
const std::string &toCheck,
|
|
const std::string &alt)
|
|
{
|
|
std::string statementStart(",|=|?|:|return");
|
|
if (!alt.empty())
|
|
statementStart += "|" + alt;
|
|
std::string statementEnd(";|,|?|:");
|
|
if (!alt.empty())
|
|
statementEnd += "|" + alt;
|
|
|
|
for (const Token *tok = classStart; tok && tok != classStart->link(); tok = tok->next()) {
|
|
if (!Token::Match(tok, toCheck.c_str()))
|
|
continue;
|
|
|
|
// look backward for the start of the statement
|
|
const Token *start = 0;
|
|
int level = 0;
|
|
for (const Token *tok1 = tok->previous(); tok1 && tok1 != classStart; tok1 = tok1->previous()) {
|
|
if (tok1->str() == ")")
|
|
level++;
|
|
else if (tok1->str() == "(")
|
|
level--;
|
|
|
|
if (level < 0 || (level == 0 && Token::Match(tok1, statementStart.c_str()))) {
|
|
start = tok1;
|
|
break;
|
|
}
|
|
}
|
|
const Token *end = 0;
|
|
level = 0;
|
|
// look for the end of the statement
|
|
for (const Token *tok1 = tok->next(); tok1 && tok1 != classStart->link(); tok1 = tok1->next()) {
|
|
if (tok1->str() == ")")
|
|
level--;
|
|
else if (tok1->str() == "(")
|
|
level++;
|
|
|
|
if (level < 0 || (level == 0 && Token::Match(tok1, statementEnd.c_str()))) {
|
|
end = tok1;
|
|
break;
|
|
}
|
|
}
|
|
checkExpressionRange(constFunctions, start, end, toCheck);
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// check for the same expression on both sides of an operator
|
|
// (x == x), (x && x), (x || x)
|
|
// (x.y == x.y), (x.y && x.y), (x.y || x.y)
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkDuplicateExpression()
|
|
{
|
|
if (!_settings->isEnabled("style"))
|
|
return;
|
|
|
|
// Parse all executing scopes..
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
std::list<Scope>::const_iterator scope;
|
|
std::list<const Function*> constFunctions;
|
|
getConstFunctions(symbolDatabase, constFunctions);
|
|
|
|
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
|
|
// only check functions
|
|
if (scope->type != Scope::eFunction)
|
|
continue;
|
|
|
|
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "%or%", "");
|
|
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "%oror%", "");
|
|
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "&", "%oror%|%or%");
|
|
complexDuplicateExpressionCheck(constFunctions, scope->classStart, "&&", "%oror%|%or%");
|
|
|
|
for (const Token *tok = scope->classStart; tok && tok != scope->classStart->link(); tok = tok->next()) {
|
|
if (Token::Match(tok, ",|=|return|(|&&|%oror% %var% %comp%|- %var% )|&&|%oror%|;|,") &&
|
|
tok->strAt(1) == tok->strAt(3)) {
|
|
// float == float and float != float are valid NaN checks
|
|
// float - float is a valid Inf check
|
|
if (Token::Match(tok->tokAt(2), "==|!=|-") && tok->next()->varId()) {
|
|
const Variable *var = tok->next()->variable();
|
|
if (var && var->typeStartToken() == var->typeEndToken()) {
|
|
if (Token::Match(var->typeStartToken(), "float|double"))
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// If either variable token is an expanded macro then
|
|
// don't write the warning
|
|
if (tok->next()->isExpandedMacro() || tok->tokAt(3)->isExpandedMacro())
|
|
continue;
|
|
|
|
duplicateExpressionError(tok->next(), tok->tokAt(3), tok->strAt(2));
|
|
} else if (Token::Match(tok, ",|=|return|(|&&|%oror% %var% . %var% %comp%|- %var% . %var% )|&&|%oror%|;|,") &&
|
|
tok->strAt(1) == tok->strAt(5) && tok->strAt(3) == tok->strAt(7)) {
|
|
|
|
// If either variable token is an expanded macro then
|
|
// don't write the warning
|
|
if (tok->next()->isExpandedMacro() || tok->tokAt(6)->isExpandedMacro())
|
|
continue;
|
|
|
|
duplicateExpressionError(tok->next(), tok->tokAt(6), tok->strAt(4));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::duplicateExpressionError(const Token *tok1, const Token *tok2, const std::string &op)
|
|
{
|
|
std::list<const Token *> toks;
|
|
toks.push_back(tok2);
|
|
toks.push_back(tok1);
|
|
|
|
reportError(toks, Severity::style, "duplicateExpression", "Same expression on both sides of \'" + op + "\'.\n"
|
|
"Finding the same expression on both sides of an operator is suspicious and might "
|
|
"indicate a cut and paste or logic error. Please examine this code carefully to "
|
|
"determine if it is correct.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check for string comparison involving two static strings.
|
|
// if(strcmp("00FF00","00FF00")==0) // <- statement is always true
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkAlwaysTrueOrFalseStringCompare()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const Token *tok = _tokenizer->tokens();
|
|
while (tok && (tok = Token::findmatch(tok, "strncmp|strcmp|stricmp|strcmpi|strcasecmp|wcscmp|wcsncmp ( %str% , %str% ")) != NULL) {
|
|
const std::string &str1 = tok->strAt(2);
|
|
const std::string &str2 = tok->strAt(4);
|
|
alwaysTrueFalseStringCompareError(tok, str1, str2);
|
|
tok = tok->tokAt(5);
|
|
}
|
|
|
|
tok = _tokenizer->tokens();
|
|
while (tok && (tok = Token::findmatch(tok, "QString :: compare ( %str% , %str% )")) != NULL) {
|
|
const std::string &str1 = tok->strAt(4);
|
|
const std::string &str2 = tok->strAt(6);
|
|
alwaysTrueFalseStringCompareError(tok, str1, str2);
|
|
tok = tok->tokAt(7);
|
|
}
|
|
|
|
tok = _tokenizer->tokens();
|
|
while (tok && (tok = Token::findmatch(tok, "strncmp|strcmp|stricmp|strcmpi|strcasecmp|wcscmp|wcsncmp ( %var% , %var% ")) != NULL) {
|
|
const std::string &str1 = tok->strAt(2);
|
|
const std::string &str2 = tok->strAt(4);
|
|
if (str1 == str2)
|
|
alwaysTrueStringVariableCompareError(tok, str1, str2);
|
|
tok = tok->tokAt(5);
|
|
}
|
|
|
|
tok = _tokenizer->tokens();
|
|
while (tok && (tok = Token::findmatch(tok, "!!+ %str% ==|!= %str% !!+")) != NULL) {
|
|
const std::string &str1 = tok->strAt(1);
|
|
const std::string &str2 = tok->strAt(3);
|
|
alwaysTrueFalseStringCompareError(tok, str1, str2);
|
|
tok = tok->tokAt(5);
|
|
}
|
|
}
|
|
|
|
void CheckOther::alwaysTrueFalseStringCompareError(const Token *tok, const std::string& str1, const std::string& str2)
|
|
{
|
|
const std::size_t stringLen = 10;
|
|
const std::string string1 = (str1.size() < stringLen) ? str1 : (str1.substr(0, stringLen-2) + "..");
|
|
const std::string string2 = (str2.size() < stringLen) ? str2 : (str2.substr(0, stringLen-2) + "..");
|
|
|
|
reportError(tok, Severity::warning, "staticStringCompare",
|
|
"Unnecessary comparison of static strings.\n"
|
|
"The compared strings, '" + string1 + "' and '" + string2 + "', are always " + (str1==str2?"identical":"unequal") + ". "
|
|
"Therefore the comparison is unnecessary and looks suspicious.");
|
|
}
|
|
|
|
void CheckOther::alwaysTrueStringVariableCompareError(const Token *tok, const std::string& str1, const std::string& str2)
|
|
{
|
|
reportError(tok, Severity::warning, "stringCompare",
|
|
"Comparison of identical string variables.\n"
|
|
"The compared strings, '" + str1 + "' and '" + str2 + "', are identical. "
|
|
"This could be a logic bug.");
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::checkSuspiciousStringCompare()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase* symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (tok->next()->type() != Token::eComparisonOp)
|
|
continue;
|
|
|
|
const Token* varTok = tok;
|
|
const Token* litTok = tok->tokAt(2);
|
|
|
|
if (varTok->strAt(-1) == "+" || litTok->strAt(1) == "+")
|
|
continue;
|
|
|
|
if ((varTok->type() == Token::eString || varTok->type() == Token::eVariable) && (litTok->type() == Token::eString || litTok->type() == Token::eVariable) && litTok->type() != varTok->type()) {
|
|
if (varTok->type() == Token::eString)
|
|
std::swap(varTok, litTok);
|
|
|
|
const Variable *var = varTok->variable();
|
|
if (var) {
|
|
if (_tokenizer->isC() ||
|
|
(var->isPointer() && varTok->strAt(-1) != "*" && !Token::Match(varTok->next(), "[.([]")))
|
|
suspiciousStringCompareError(tok, var->name());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::suspiciousStringCompareError(const Token* tok, const std::string& var)
|
|
{
|
|
reportError(tok, Severity::warning, "literalWithCharPtrCompare",
|
|
"String literal compared with variable '" + var + "'. Did you intend to use strcmp() instead?");
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::checkModuloAlwaysTrueFalse()
|
|
{
|
|
if (!_settings->isEnabled("warning"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if ((Token::Match(tok, "% %num% %comp% %num%")) &&
|
|
(!tok->tokAt(4) || !tok->tokAt(4)->isArithmeticalOp())) {
|
|
if (MathLib::isLessEqual(tok->strAt(1), tok->strAt(3)))
|
|
moduloAlwaysTrueFalseError(tok, tok->strAt(1));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::moduloAlwaysTrueFalseError(const Token* tok, const std::string& maxVal)
|
|
{
|
|
reportError(tok, Severity::warning, "moduloAlwaysTrueFalse",
|
|
"Comparison of modulo result is predetermined, because it is always less than " + maxVal + ".");
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
// Check for code like:
|
|
// seteuid(geteuid()) or setuid(getuid()), which first gets and then sets the
|
|
// (effective) user id to itself. Very often this indicates a copy and paste
|
|
// error.
|
|
//-----------------------------------------------------------------------------
|
|
void CheckOther::redundantGetAndSetUserId()
|
|
{
|
|
if (_settings->isEnabled("warning")
|
|
&& _settings->standards.posix) {
|
|
|
|
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
|
|
if (Token::simpleMatch(tok, "setuid ( getuid ( ) )")
|
|
|| Token::simpleMatch(tok, "seteuid ( geteuid ( ) )")
|
|
|| Token::simpleMatch(tok, "setgid ( getgid ( ) )")
|
|
|| Token::simpleMatch(tok, "setegid ( getegid ( ) )")) {
|
|
redundantGetAndSetUserIdError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
void CheckOther::redundantGetAndSetUserIdError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::warning,
|
|
"redundantGetAndSetUserId", "Redundant get and set of user id.\n"
|
|
"Redundant statement without any effect. First the user id is retrieved"
|
|
"by get(e)uid() and then set with set(e)uid().", false);
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check testing sign of unsigned variables and pointers.
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkSignOfUnsignedVariable()
|
|
{
|
|
if (!_settings->isEnabled("style"))
|
|
return;
|
|
|
|
const bool inconclusive = _tokenizer->codeWithTemplates();
|
|
if (inconclusive && !_settings->inconclusive)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
// check all the code in the function
|
|
for (const Token *tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "%var% <|<= 0") && tok->varId() && !Token::Match(tok->previous(), "++|--|)|+|-|*|/|~|<<|>>") && !Token::Match(tok->tokAt(3), "+|-")) {
|
|
const Variable *var = tok->variable();
|
|
if (var && var->typeEndToken()->isUnsigned())
|
|
unsignedLessThanZeroError(tok, var->name(), inconclusive);
|
|
else if (var && var->isPointer() && tok->strAt(-1) != "*")
|
|
pointerLessThanZeroError(tok, inconclusive);
|
|
} else if (Token::Match(tok, "0 >|>= %var%") && tok->tokAt(2)->varId() && !Token::Match(tok->tokAt(3), "+|-|*|/") && !Token::Match(tok->previous(), "+|-|<<|>>|~")) {
|
|
const Variable *var = tok->tokAt(2)->variable();
|
|
if (var && var->typeEndToken()->isUnsigned())
|
|
unsignedLessThanZeroError(tok, var->name(), inconclusive);
|
|
else if (var && var->isPointer() && !Token::Match(tok->tokAt(3), "[.[]"))
|
|
pointerLessThanZeroError(tok, inconclusive);
|
|
} else if (Token::Match(tok, "0 <= %var%") && tok->tokAt(2)->varId() && !Token::Match(tok->tokAt(3), "+|-|*|/") && !Token::Match(tok->previous(), "+|-|<<|>>|~")) {
|
|
const Variable *var = tok->tokAt(2)->variable();
|
|
if (var && var->typeEndToken()->isUnsigned())
|
|
unsignedPositiveError(tok, var->name(), inconclusive);
|
|
else if (var && var->isPointer() && !Token::Match(tok->tokAt(3), "[.[]"))
|
|
pointerPositiveError(tok, inconclusive);
|
|
} else if (Token::Match(tok, "%var% >= 0") && tok->varId() && !Token::Match(tok->previous(), "++|--|)|+|-|*|/|~|<<|>>") && !Token::Match(tok->tokAt(3), "+|-")) {
|
|
const Variable *var = tok->variable();
|
|
if (var && var->typeEndToken()->isUnsigned())
|
|
unsignedPositiveError(tok, var->name(), inconclusive);
|
|
else if (var && var->isPointer() && tok->strAt(-1) != "*")
|
|
pointerPositiveError(tok, inconclusive);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::unsignedLessThanZeroError(const Token *tok, const std::string &varname, bool inconclusive)
|
|
{
|
|
if (inconclusive) {
|
|
reportError(tok, Severity::style, "unsignedLessThanZero",
|
|
"Checking if unsigned variable '" + varname + "' is less than zero. This might be a false warning.\n"
|
|
"Checking if unsigned variable '" + varname + "' is less than zero. An unsigned "
|
|
"variable will never be negative so it is either pointless or an error to check if it is. "
|
|
"It's not known if the used constant is a template parameter or not and therefore "
|
|
"this message might be a false warning.", true);
|
|
} else {
|
|
reportError(tok, Severity::style, "unsignedLessThanZero",
|
|
"Checking if unsigned variable '" + varname + "' is less than zero.\n"
|
|
"The unsigned variable '" + varname + "' will never be negative so it "
|
|
"is either pointless or an error to check if it is.");
|
|
}
|
|
}
|
|
|
|
void CheckOther::pointerLessThanZeroError(const Token *tok, bool inconclusive)
|
|
{
|
|
reportError(tok, Severity::style, "pointerLessThanZero",
|
|
"A pointer can not be negative so it is either pointless or an error to check if it is.", inconclusive);
|
|
}
|
|
|
|
void CheckOther::unsignedPositiveError(const Token *tok, const std::string &varname, bool inconclusive)
|
|
{
|
|
if (inconclusive) {
|
|
reportError(tok, Severity::style, "unsignedPositive",
|
|
"Unsigned variable '" + varname + "' can't be negative so it is unnecessary to test it.\n"
|
|
"The unsigned variable '" + varname + "' can't be negative so it is unnecessary to test it. "
|
|
"It's not known if the used constant is a "
|
|
"template parameter or not and therefore this message might be a false warning", true);
|
|
} else {
|
|
reportError(tok, Severity::style, "unsignedPositive",
|
|
"Unsigned variable '" + varname + "' can't be negative so it is unnecessary to test it.");
|
|
}
|
|
}
|
|
|
|
void CheckOther::pointerPositiveError(const Token *tok, bool inconclusive)
|
|
{
|
|
reportError(tok, Severity::style, "pointerPositive",
|
|
"A pointer can not be negative so it is either pointless or an error to check if it is not.", inconclusive);
|
|
}
|
|
|
|
/*
|
|
This check rule works for checking the "const A a = getA()" usage when getA() returns "const A &" or "A &".
|
|
In most scenarios, "const A & a = getA()" will be more efficient.
|
|
*/
|
|
void CheckOther::checkRedundantCopy()
|
|
{
|
|
if (!_settings->isEnabled("performance") || _tokenizer->isC())
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (std::size_t i = 0; i < symbolDatabase->getVariableListSize(); i++) {
|
|
const Variable* var = symbolDatabase->getVariableFromVarId(i);
|
|
|
|
if (!var || var->isReference() || !var->isConst() || var->isPointer() || !var->type()) // bailout if var is of standard type, if it is a pointer or non-const
|
|
continue;
|
|
|
|
const Token* startTok = var->nameToken();
|
|
const Token* endToken;
|
|
if (startTok->strAt(1) == "=") // %type% %var% = ... ;
|
|
endToken = Token::findsimplematch(startTok->tokAt(2), ";");
|
|
else if (startTok->strAt(1) == "(") // %type% %var%(...)
|
|
endToken = startTok->linkAt(1);
|
|
else
|
|
continue;
|
|
|
|
const Token* tok = startTok->tokAt(2);
|
|
while (tok && Token::Match(tok, "%var% .|::"))
|
|
tok = tok->tokAt(2);
|
|
if (!Token::Match(tok, "%var% ("))
|
|
continue;
|
|
if (tok->linkAt(1)->next() != endToken) // bailout for usage like "const A a = getA()+3"
|
|
continue;
|
|
|
|
const Function* func = tok->function();
|
|
if (func && func->tokenDef->strAt(-1) == "&") {
|
|
redundantCopyError(startTok, startTok->str());
|
|
}
|
|
}
|
|
}
|
|
void CheckOther::redundantCopyError(const Token *tok,const std::string& varname)
|
|
{
|
|
reportError(tok, Severity::performance, "redundantCopyLocalConst",
|
|
"Use const reference for '" + varname + "' to avoid unnecessary data copying.\n"
|
|
"The const variable '"+varname+"' is assigned a copy of the data. You can avoid "
|
|
"the unnecessary data copying by converting '" + varname + "' to const reference.");
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Checking for shift by negative values
|
|
//---------------------------------------------------------------------------
|
|
|
|
void CheckOther::checkNegativeBitwiseShift()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
|
|
if ((Token::Match(tok,"%var% >>|<< %num%") || Token::Match(tok,"%num% >>|<< %num%")) && !Token::Match(tok->previous(),">>|<<")) {
|
|
if (tok->isName()) {
|
|
const Variable *var = tok->variable();
|
|
if (var && var->typeStartToken()->isStandardType() && (tok->strAt(2))[0] == '-')
|
|
negativeBitwiseShiftError(tok);
|
|
} else {
|
|
if ((tok->strAt(2))[0] == '-')
|
|
negativeBitwiseShiftError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void CheckOther::negativeBitwiseShiftError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::error, "shiftNegative", "Shifting by a negative value.");
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check for incompletely filled buffers.
|
|
//---------------------------------------------------------------------------
|
|
void CheckOther::checkIncompleteArrayFill()
|
|
{
|
|
bool warning = _settings->isEnabled("warning");
|
|
bool portability = _settings->isEnabled("portability");
|
|
if (!_settings->inconclusive || (!portability && !warning))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "memset|memcpy|memmove ( %var% ,") && Token::Match(tok->linkAt(1)->tokAt(-2), ", %num% )")) {
|
|
const Variable *var = tok->tokAt(2)->variable();
|
|
if (!var || !var->isArray() || var->dimensions().empty() || !var->dimension(0))
|
|
continue;
|
|
|
|
if (MathLib::toLongNumber(tok->linkAt(1)->strAt(-1)) == var->dimension(0)) {
|
|
unsigned int size = _tokenizer->sizeOfType(var->typeStartToken());
|
|
if ((size != 1 && size != 100 && size != 0) || var->isPointer()) {
|
|
if (warning)
|
|
incompleteArrayFillError(tok, var->name(), tok->str(), false);
|
|
} else if (var->typeStartToken()->str() == "bool" && portability) // sizeof(bool) is not 1 on all platforms
|
|
incompleteArrayFillError(tok, var->name(), tok->str(), true);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::incompleteArrayFillError(const Token* tok, const std::string& buffer, const std::string& function, bool boolean)
|
|
{
|
|
if (boolean)
|
|
reportError(tok, Severity::portability, "incompleteArrayFill",
|
|
"Array '" + buffer + "' might be filled incompletely. Did you forget to multiply the size given to '" + function + "()' with 'sizeof(*" + buffer + ")'?\n"
|
|
"The array '" + buffer + "' is filled incompletely. The function '" + function + "()' needs the size given in bytes, but the type 'bool' is larger than 1 on some platforms. Did you forget to multiply the size with 'sizeof(*" + buffer + ")'?", true);
|
|
else
|
|
reportError(tok, Severity::warning, "incompleteArrayFill",
|
|
"Array '" + buffer + "' is filled incompletely. Did you forget to multiply the size given to '" + function + "()' with 'sizeof(*" + buffer + ")'?\n"
|
|
"The array '" + buffer + "' is filled incompletely. The function '" + function + "()' needs the size given in bytes, but an element of the given array is larger than one byte. Did you forget to multiply the size with 'sizeof(*" + buffer + ")'?", true);
|
|
}
|
|
|
|
|
|
void CheckOther::oppositeInnerCondition()
|
|
{
|
|
// FIXME: This check is experimental because of #4170 and #4186. Fix those tickets and remove the "experimental".
|
|
if (!_settings->isEnabled("warning") || !_settings->inconclusive || !_settings->experimental)
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
|
|
for (std::list<Scope>::const_iterator scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
|
|
const Token* const toke = scope->classDef;
|
|
|
|
|
|
if (scope->type == Scope::eIf && toke) {
|
|
|
|
const Token *op1Tok, *op2Tok;
|
|
op1Tok = scope->classDef->tokAt(2);
|
|
op2Tok = scope->classDef->tokAt(4);
|
|
|
|
if (scope->classDef->strAt(6) == "{") {
|
|
|
|
const char *oppositeCondition = NULL;
|
|
|
|
if (scope->classDef->strAt(3) == "==")
|
|
oppositeCondition = "if ( %any% !=|<|>|<=|>= %any% )";
|
|
else if (scope->classDef->strAt(3) == "!=")
|
|
oppositeCondition = "if ( %any% ==|>=|<= %any% )";
|
|
else if (scope->classDef->strAt(3) == "<")
|
|
oppositeCondition = "if ( %any% >|>=|== %any% )";
|
|
else if (scope->classDef->strAt(3) == "<=")
|
|
oppositeCondition = "if ( %any% > %any% )";
|
|
else if (scope->classDef->strAt(3) == ">")
|
|
oppositeCondition = "if ( %any% <|<=|== %any% )";
|
|
else if (scope->classDef->strAt(3) == ">=")
|
|
oppositeCondition = "if ( %any% < %any% )";
|
|
|
|
if (oppositeCondition) {
|
|
int flag = 0;
|
|
|
|
for (const Token* tok = scope->classStart; tok != scope->classEnd && flag == 0; tok = tok->next()) {
|
|
if ((tok->str() == op1Tok->str() || tok->str() == op2Tok->str()) && tok->strAt(1) == "=")
|
|
break;
|
|
else if (Token::Match(tok, "%any% ( %any% )")) {
|
|
if ((tok->strAt(2) == op1Tok->str() || tok->strAt(2) == op2Tok->str()))
|
|
break;
|
|
} else if (Token::Match(tok, "%any% ( %any% , %any%")) {
|
|
for (const Token* tok2 = tok->next(); tok2 != tok->linkAt(1); tok2 = tok2->next()) {
|
|
if (tok2->str() == op1Tok->str()) {
|
|
flag = 1;
|
|
break;
|
|
}
|
|
}
|
|
} else if (Token::Match(tok, oppositeCondition)) {
|
|
if ((tok->strAt(2) == op1Tok->str() && tok->strAt(4) == op2Tok->str()) || (tok->strAt(2) == op2Tok->str() && tok->strAt(4) == op1Tok->str()))
|
|
oppositeInnerConditionError(toke);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::oppositeInnerConditionError(const Token *tok)
|
|
{
|
|
reportError(tok, Severity::warning, "oppositeInnerCondition", "Opposite conditions in nested 'if' blocks lead to a dead code block.", true);
|
|
}
|
|
|
|
|
|
void CheckOther::checkVarFuncNullUB()
|
|
{
|
|
if (!_settings->isEnabled("portability"))
|
|
return;
|
|
|
|
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
|
|
const std::size_t functions = symbolDatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symbolDatabase->functionScopes[i];
|
|
for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
|
|
// Is NULL passed to a function?
|
|
if (Token::Match(tok,"[(,] NULL [,)]")) {
|
|
// Locate function name in this function call.
|
|
const Token *ftok = tok;
|
|
std::size_t argnr = 1;
|
|
while (ftok && ftok->str() != "(") {
|
|
if (ftok->str() == ")")
|
|
ftok = ftok->link();
|
|
else if (ftok->str() == ",")
|
|
++argnr;
|
|
ftok = ftok->previous();
|
|
}
|
|
ftok = ftok ? ftok->previous() : NULL;
|
|
if (ftok && ftok->isName()) {
|
|
// If this is a variadic function then report error
|
|
const Function *f = ftok->function();
|
|
if (f && f->argCount() <= argnr) {
|
|
const Token *tok2 = f->argDef;
|
|
tok2 = tok2 ? tok2->link() : NULL; // goto ')'
|
|
if (Token::simpleMatch(tok2->tokAt(-3), ". . ."))
|
|
varFuncNullUBError(tok);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckOther::varFuncNullUBError(const Token *tok)
|
|
{
|
|
reportError(tok,
|
|
Severity::portability,
|
|
"varFuncNullUB",
|
|
"Passing NULL after the last typed argument to a variadic function leads to undefined behaviour.\n"
|
|
"Passing NULL after the last typed argument to a variadic function leads to undefined behaviour.\n"
|
|
"The C99 standard, in section 7.15.1.1, states that if the type used by va_arg() is not compatible with the type of the actual next argument (as promoted according to the default argument promotions), the behavior is undefined.\n"
|
|
"The value of the NULL macro is an implementation-defined null pointer constant (7.17), which can be any integer constant expression with the value 0, or such an expression casted to (void*) (6.3.2.3). This includes values like 0, 0L, or even 0LL.\n"
|
|
"In practice on common architectures, this will cause real crashes if sizeof(int) != sizeof(void*), and NULL is defined to 0 or any other null pointer constant that promotes to int.\n"
|
|
"To reproduce you might be able to use this little code example on 64bit platforms. If the output includes \"ERROR\", the sentinel had only 4 out of 8 bytes initialized to zero and was not detected as the final argument to stop argument processing via va_arg(). Changing the 0 to (void*)0 or 0L will make the \"ERROR\" output go away.\n"
|
|
"#include <stdarg.h>\n"
|
|
"#include <stdio.h>\n"
|
|
"\n"
|
|
"void f(char *s, ...) {\n"
|
|
" va_list ap;\n"
|
|
" va_start(ap,s);\n"
|
|
" for (;;) {\n"
|
|
" char *p = va_arg(ap,char*);\n"
|
|
" printf(\"%018p, %s\n\", p, (long)p & 255 ? p : \"\");\n"
|
|
" if(!p) break;\n"
|
|
" }\n"
|
|
" va_end(ap);\n"
|
|
"}\n"
|
|
"\n"
|
|
"void g() {\n"
|
|
" char *s2 = \"x\";\n"
|
|
" char *s3 = \"ERROR\";\n"
|
|
"\n"
|
|
" // changing 0 to 0L for the 7th argument (which is intended to act as sentinel) makes the error go away on x86_64\n"
|
|
" f(\"first\", s2, s2, s2, s2, s2, 0, s3, (char*)0);\n"
|
|
"}\n"
|
|
"\n"
|
|
"void h() {\n"
|
|
" int i;\n"
|
|
" volatile unsigned char a[1000];\n"
|
|
" for (i = 0; i<sizeof(a); i++)\n"
|
|
" a[i] = -1;\n"
|
|
"}\n"
|
|
"\n"
|
|
"int main() {\n"
|
|
" h();\n"
|
|
" g();\n"
|
|
" return 0;\n"
|
|
"}");
|
|
}
|