cppcheck/src/checkautovariables.cpp

293 lines
8.8 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2009 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/
*/
//---------------------------------------------------------------------------
// Auto variables checks
//---------------------------------------------------------------------------
#include "checkautovariables.h"
#include <algorithm>
#include <sstream>
#include <list>
#include <iostream>
#include <string>
//---------------------------------------------------------------------------
// Register this check class into cppcheck by creating a static instance of it..
namespace
{
static CheckAutoVariables instance;
}
// _callStack used when parsing into subfunctions.
bool CheckAutoVariables::errorAv(const Token* left, const Token* right)
{
const std::string left_var(left->str());
const std::string right_var(right->str());
std::list<std::string>::iterator it_fp;
for (it_fp = fp_list.begin(); it_fp != fp_list.end(); ++it_fp)
{
std::string vname(*it_fp);
//The left argument is a formal parameter
if (vname == left_var)
{
//cout << "Beccato" << endl;
break;
}
}
//The left argument is NOT a formal parameter
if (it_fp == fp_list.end())
return false;
std::list<std::string>::iterator id_vd;
for (id_vd = vd_list.begin(); id_vd != vd_list.end(); ++id_vd)
{
std::string vname(*id_vd);
//The left argument is a variable declaration
if (vname == right_var)
break;
}
//The left argument is NOT a variable declaration
if (id_vd == vd_list.end())
return false;
//If I reach this point there is a wrong assignement of an auto-variable to an effective parameter of a function
return true;
}
bool CheckAutoVariables::isAutoVar(const Token* t)
{
std::list<std::string>::iterator id_vd;
std::string v(t->str());
for (id_vd = vd_list.begin(); id_vd != vd_list.end(); ++id_vd)
{
std::string vname(*id_vd);
if (vname == v)
return true;
}
return false;
}
void print(const Token *tok, int num)
{
const Token *t = tok;
std::cout << tok->linenr() << " PRINT ";
for (int i = 0; i < num; i++)
{
std::cout << " [" << t->str() << "] ";
t = t->next();
}
std::cout << std::endl;
}
bool isTypeName(const Token *tok)
{
bool ret = false;
std::string _str(tok->str());
static const char * const type[] = {"case", "return", "delete", 0};
for (int i = 0; type[i]; i++)
ret |= (_str == type[i]);
return !ret;
}
bool isExternOrStatic(const Token *tok)
{
bool res = false;
if (Token::Match(tok->tokAt(-1), "extern|static"))
res = true;
else if (Token::Match(tok->tokAt(-2), "extern|static"))
res = true;
else if (Token::Match(tok->tokAt(-3), "extern|static"))
res = true;
//std::cout << __PRETTY_FUNCTION__ << " " << tok->str() << " " << res << std::endl;
return res;
}
void CheckAutoVariables::addVD(const Token* tok)
{
std::string var_name(tok->str());
//std::cout << "VD " << tok->linenr() << " " << var_name << std::endl;
vd_list.push_back(var_name);
}
void CheckAutoVariables::autoVariables()
{
bool begin_function = false;
bool begin_function_decl = false;
int bindent = 0;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
if (Token::Match(tok, "%type% *|::| %var% ("))
{
begin_function = true;
fp_list.clear();
vd_list.clear();
}
else if (begin_function && begin_function_decl && Token::Match(tok, "%type% * * %var%"))
{
std::string var_name(tok->tokAt(3)->str());
fp_list.push_back(var_name);
}
else if (begin_function && begin_function_decl && Token::Match(tok, "%type% * %var% ["))
{
std::string var_name(tok->tokAt(2)->str());
fp_list.push_back(var_name);
}
else if (begin_function && tok->str() == "(")
begin_function_decl = true;
else if (begin_function && tok->str() == ")")
{
begin_function_decl = false;
}
else if (begin_function && tok->str() == "{")
bindent++;
else if (begin_function && tok->str() == "}")
{
bindent--;
}
else if (bindent > 0 && Token::Match(tok, "%type% :: %any%") && !isExternOrStatic(tok)) //Inside a function
{
addVD(tok->tokAt(2));
}
else if (bindent > 0 && Token::Match(tok, "%var% %var% ;") && !isExternOrStatic(tok)) //Inside a function
{
if (!isTypeName(tok))
continue;
addVD(tok->tokAt(1));
}
else if (bindent > 0 && Token::Match(tok, "const %var% %var% ;") && !isExternOrStatic(tok)) //Inside a function
{
if (!isTypeName(tok->tokAt(1)))
continue;
addVD(tok->tokAt(2));
}
else if (bindent > 0 && Token::Match(tok, "[;{}] %var% = & %var%")) //Critical assignement
{
if (errorAv(tok->tokAt(1), tok->tokAt(4)))
reportError(tok,
Severity::error,
"autoVariables",
"Wrong assignement of an auto-variable to an effective parameter of a function");
}
else if (bindent > 0 && Token::Match(tok, "[;{}] %var% [ %any% ] = & %var%")) //Critical assignement
{
if (errorAv(tok->tokAt(1), tok->tokAt(7)))
reportError(tok,
Severity::error,
"autoVariables",
"Wrong assignement of an auto-variable to an effective parameter of a function");
}
else if (bindent > 0 && Token::Match(tok, "return & %var% ;")) //Critical return
{
if (isAutoVar(tok->tokAt(2)))
reportError(tok,
Severity::error,
"autoVariables",
"Return of the address of an auto-variable");
}
}
vd_list.clear();
fp_list.clear();
}
//---------------------------------------------------------------------------
void CheckAutoVariables::returnPointerToLocalArray()
{
bool infunc = false;
int indentlevel = 0;
std::list<unsigned int> arrayVar;
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Is there a function declaration for a function that returns a pointer?
if (!infunc && (Token::Match(tok, "%type% * %var% (") || Token::Match(tok, "%type% * %var% :: %var% (")))
{
for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
{
if (tok2->str() == ")")
{
tok = tok2;
break;
}
}
if (Token::simpleMatch(tok, ") {"))
{
infunc = true;
indentlevel = 0;
arrayVar.clear();
}
}
// Parsing a function that returns a pointer..
if (infunc)
{
if (tok->str() == "{")
++indentlevel;
else if (tok->str() == "}")
{
--indentlevel;
if (indentlevel <= 0)
infunc = false;
continue;
}
// Declaring a local array..
if (Token::Match(tok, "[;{}] %type% %var% ["))
{
arrayVar.push_back(tok->tokAt(2)->varId());
}
// Return pointer to local array variable..
if (Token::Match(tok, "return %var% ;"))
{
unsigned int varid = tok->next()->varId();
if (varid > 0 && std::find(arrayVar.begin(), arrayVar.end(), varid) != arrayVar.end())
errorReturnPointerToLocalArray(tok);
}
}
// Declaring array variable..
}
}
void CheckAutoVariables::errorReturnPointerToLocalArray(const Token *tok)
{
reportError(tok, Severity::error, "returnLocalVariable", "Returning pointer to local array variable");
}