cppcheck/lib/checkunusedfunctions.cpp

201 lines
6.8 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2011 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
//---------------------------------------------------------------------------
#include "checkunusedfunctions.h"
#include "tokenize.h"
#include "token.h"
#include <cctype>
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
// FUNCTION USAGE - Check for unused functions etc
//---------------------------------------------------------------------------
void CheckUnusedFunctions::parseTokens(const Tokenizer &tokenizer)
{
// if there are templates there might be false positives
templates |= tokenizer.codeWithTemplates();
if (templates)
return;
// Function declarations..
for (const Token *tok = tokenizer.tokens(); tok; tok = tok->next()) {
if (tok->fileIndex() != 0)
continue;
// token contains a ':' => skip to next ; or {
if (tok->str().find(":") != std::string::npos) {
while (tok && tok->str().find_first_of(";{"))
tok = tok->next();
if (tok)
continue;
break;
}
// If this is a template function, skip it
if (tok->previous() && tok->previous()->str() == ">")
continue;
const Token *funcname = 0;
if (Token::Match(tok, "%type% %var% ("))
funcname = tok->next();
else if (Token::Match(tok, "%type% * %var% ("))
funcname = tok->tokAt(2);
else if (Token::Match(tok, "%type% :: %var% (") && !Token::Match(tok, tok->strAt(2).c_str()))
funcname = tok->tokAt(2);
// Don't assume throw as a function name: void foo() throw () {}
if (Token::Match(tok->previous(), ")|const"))
funcname = 0;
// Check that ") {" is found..
for (const Token *tok2 = funcname; tok2; tok2 = tok2->next()) {
if (tok2->str() == ")") {
if (! Token::simpleMatch(tok2, ") {") &&
! Token::simpleMatch(tok2, ") const {") &&
! Token::simpleMatch(tok2, ") const throw ( ) {") &&
! Token::simpleMatch(tok2, ") throw ( ) {"))
funcname = 0;
break;
}
}
if (funcname) {
FunctionUsage &func = _functions[ funcname->str()];
if (!func.lineNumber)
func.lineNumber = funcname->linenr();
// No filename set yet..
if (func.filename.empty()) {
func.filename = tokenizer.getFiles()->at(0);
}
// Multiple files => filename = "+"
else if (func.filename != tokenizer.getFiles()->at(0)) {
//func.filename = "+";
func.usedOtherFile |= func.usedSameFile;
}
}
}
// Function usage..
for (const Token *tok = tokenizer.tokens(); tok; tok = tok->next()) {
const Token *funcname = 0;
if (Token::Match(tok->next(), "%var% (")) {
funcname = tok->next();
}
else if (Token::Match(tok, "[;{}.,()[=+-/&|!?:] %var% [(),;:}]"))
funcname = tok->next();
else if (Token::Match(tok, "[=(,] & %var% :: %var% [,);]"))
funcname = tok->tokAt(4);
else
continue;
// funcname ( => Assert that the end parenthesis isn't followed by {
if (Token::Match(funcname, "%var% (")) {
int parlevel = 0;
for (const Token *tok2 = funcname; tok2; tok2 = tok2->next()) {
if (tok2->str() == "(")
++parlevel;
else if (tok2->str() == ")") {
--parlevel;
if (parlevel == 0 && (Token::Match(tok2, ") const|{")))
funcname = NULL;
if (parlevel <= 0)
break;
}
}
}
if (funcname) {
FunctionUsage &func = _functions[ funcname->str()];
if (func.filename.empty() || func.filename == "+")
func.usedOtherFile = true;
else
func.usedSameFile = true;
}
}
}
void CheckUnusedFunctions::check(ErrorLogger * const errorLogger)
{
if (templates)
return;
for (std::map<std::string, FunctionUsage>::const_iterator it = _functions.begin(); it != _functions.end(); ++it) {
const FunctionUsage &func = it->second;
if (func.usedOtherFile || func.filename.empty())
continue;
if (it->first == "main" ||
it->first == "WinMain" ||
it->first == "_tmain" ||
it->first == "if" ||
(it->first.compare(0, 8, "operator") == 0 && it->first.size() > 8 && !std::isalnum(it->first[8])))
continue;
if (! func.usedSameFile) {
std::string filename;
if (func.filename == "+")
filename = "";
else
filename = func.filename;
unusedFunctionError(errorLogger, filename, func.lineNumber, it->first);
} else if (! func.usedOtherFile) {
/** @todo add error message "function is only used in <file> it can be static" */
/*
std::ostringstream errmsg;
errmsg << "The function '" << it->first << "' is only used in the file it was declared in so it should have local linkage.";
_errorLogger->reportErr( errmsg.str() );
*/
}
}
}
void CheckUnusedFunctions::unusedFunctionError(ErrorLogger * const errorLogger,
const std::string &filename, unsigned int lineNumber,
const std::string &funcname)
{
std::list<ErrorLogger::ErrorMessage::FileLocation> locationList;
if (!filename.empty()) {
ErrorLogger::ErrorMessage::FileLocation fileLoc;
fileLoc.setfile(filename);
fileLoc.line = lineNumber;
locationList.push_back(fileLoc);
}
const ErrorLogger::ErrorMessage errmsg(locationList, Severity::style, "The function '" + funcname + "' is never used", "unusedFunction", false);
if (errorLogger)
errorLogger->reportErr(errmsg);
else
reportError(errmsg);
}