/* * Cppcheck - A tool for static C/C++ code analysis * Copyright (C) 2007-2010 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 . */ #include "checkmemoryleak.h" #include "mathlib.h" #include "tokenize.h" #include "executionpath.h" #include #include #include #include #include #include //--------------------------------------------------------------------------- // Register this check class (by creating a static instance of it) namespace { CheckMemoryLeakInFunction instance1; CheckMemoryLeakInClass instance2; CheckMemoryLeakStructMember instance3; } // This list needs to be alphabetically sorted so we can run bsearch on it static const char * const call_func_white_list[] = { "asctime", "asctime_r", "asprintf", "atof", "atoi", "atol", "clearerr" , "ctime", "ctime_r", "delete", "fchmod", "fcntl" , "fdatasync", "feof", "ferror", "fflush", "fgetc", "fgetpos", "fgets" , "flock", "for", "fprintf", "fputc", "fputs", "fread", "free", "fscanf", "fseek" , "fseeko", "fsetpos", "fstat", "fsync", "ftell", "ftello", "ftruncate" , "fwrite", "getc", "gets", "gmtime", "gmtime_r", "if", "ioctl" , "localtime", "localtime_r" , "lockf", "lseek", "memchr", "memcmp", "memcpy", "memmove", "memset" , "posix_fadvise", "posix_fallocate", "pread" , "printf", "puts", "pwrite", "qsort", "read", "readahead", "readdir", "readdir_r", "readv" , "realloc", "return", "rewind", "rewinddir", "scandir", "scanf", "seekdir" , "setbuf", "setbuffer", "setlinebuf", "setvbuf", "snprintf", "sprintf", "sscanf", "strcasecmp" , "strcat", "strchr", "strcmp", "strcpy", "stricmp", "strlen", "strncat", "strncmp" , "strncpy", "strrchr", "strstr", "strtod", "strtol", "strtoul", "switch" , "sync_file_range", "telldir", "time", "typeid", "vfprintf", "vprintf" , "vsnprintf", "vsprintf", "while", "write", "writev" }; static int call_func_white_list_compare(const void *a, const void *b) { return strcmp((const char *)a, *(const char **)b); } //--------------------------------------------------------------------------- bool CheckMemoryLeak::isclass(const Tokenizer *_tokenizer, const Token *tok) const { if (tok->isStandardType()) return false; std::ostringstream pattern; pattern << "struct " << tok->str(); if (Token::findmatch(_tokenizer->tokens(), pattern.str().c_str())) return false; return true; } //--------------------------------------------------------------------------- CheckMemoryLeak::AllocType CheckMemoryLeak::getAllocationType(const Token *tok2, unsigned int varid) const { // What we may have... // * var = (char *)malloc(10); // * var = new char[10]; // * var = strdup("hello"); // * var = strndup("hello", 3); if (tok2 && tok2->str() == "(") { tok2 = tok2->link(); tok2 = tok2 ? tok2->next() : NULL; } if (! tok2) return No; if (! tok2->isName()) return No; // Does tok2 point on "malloc", "strdup" or "kmalloc".. static const char * const mallocfunc[] = {"malloc", "calloc", "strdup", "strndup", "kmalloc", "kzalloc", "kcalloc", 0 }; for (unsigned int i = 0; mallocfunc[i]; i++) { if (tok2->str() == mallocfunc[i]) return Malloc; } // Using realloc.. if (varid && Token::Match(tok2, "realloc ( %any% ,") && tok2->tokAt(2)->varId() != varid) return Malloc; // Does tok2 point on "g_malloc", "g_strdup", .. static const char * const gmallocfunc[] = {"g_new", "g_new0", "g_try_new", "g_try_new0", "g_malloc", "g_malloc0", "g_try_malloc", "g_try_malloc0", "g_strdup", "g_strndup", 0 }; for (unsigned int i = 0; gmallocfunc[i]; i++) { if (tok2->str() == gmallocfunc[i]) return gMalloc; } if (Token::Match(tok2, "new %type% [;()]") || Token::Match(tok2, "new ( std :: nothrow ) %type% [;()]") || Token::Match(tok2, "new ( nothrow ) %type% [;()]")) return New; if (Token::Match(tok2, "new %type% [") || Token::Match(tok2, "new ( std :: nothrow ) %type% [") || Token::Match(tok2, "new ( nothrow ) %type% [")) return NewArray; if (Token::Match(tok2, "fopen|tmpfile (")) return File; if (Token::Match(tok2, "open|openat|creat|mkstemp|mkostemp (")) { // is there a user function with this name? if (tokenizer && Token::findmatch(tokenizer->tokens(), ("%type% *|&| " + tok2->str()).c_str())) return No; return Fd; } if (Token::simpleMatch(tok2, "popen (")) return Pipe; if (Token::Match(tok2, "opendir|fdopendir (")) return Dir; return No; } CheckMemoryLeak::AllocType CheckMemoryLeak::getReallocationType(const Token *tok2, unsigned int varid) const { // What we may have... // * var = (char *)realloc(..; if (tok2 && tok2->str() == "(") { tok2 = tok2->link(); tok2 = tok2 ? tok2->next() : NULL; } if (! tok2) return No; if (varid > 0 && ! Token::Match(tok2, "%var% ( %varid% [,)]", varid)) return No; if (tok2->str() == "realloc") return Malloc; // GTK memory reallocation.. if (Token::Match(tok2, "g_realloc|g_try_realloc|g_renew|g_try_renew")) return gMalloc; return No; } CheckMemoryLeak::AllocType CheckMemoryLeak::getDeallocationType(const Token *tok, unsigned int varid) const { if (Token::Match(tok, "delete %varid% ;", varid)) return New; if (Token::Match(tok, "delete [ ] %varid% ;", varid)) return NewArray; if (Token::Match(tok, "delete ( %varid% ) ;", varid)) return New; if (Token::Match(tok, "delete [ ] ( %varid% ) ;", varid)) return NewArray; if (Token::Match(tok, "free ( %varid% ) ;", varid) || Token::Match(tok, "kfree ( %varid% ) ;", varid)) return Malloc; if (Token::Match(tok, "g_free ( %varid% ) ;", varid)) return gMalloc; if (Token::Match(tok, "fclose ( %varid% )", varid) || Token::Match(tok, "fcloseall ( )")) return File; if (Token::Match(tok, "close ( %varid% )", varid)) return Fd; if (Token::Match(tok, "pclose ( %varid% )", varid)) return Pipe; if (Token::Match(tok, "closedir ( %varid% )", varid)) return Dir; return No; } CheckMemoryLeak::AllocType CheckMemoryLeak::getDeallocationType(const Token *tok, const char *varnames[]) const { int i = 0; std::string names; while (varnames[i]) { if (i > 0) names += " . "; names += varnames[i]; i++; } if (Token::simpleMatch(tok, std::string("delete " + names + " ;").c_str())) return New; if (Token::simpleMatch(tok, std::string("delete [ ] " + names + " ;").c_str())) return NewArray; if (Token::simpleMatch(tok, std::string("delete ( " + names + " ) ;").c_str())) return New; if (Token::simpleMatch(tok, std::string("delete [ ] ( " + names + " ) ;").c_str())) return NewArray; if (Token::simpleMatch(tok, std::string("free ( " + names + " ) ;").c_str()) || Token::simpleMatch(tok, std::string("kfree ( " + names + " ) ;").c_str())) return Malloc; if (Token::simpleMatch(tok, std::string("g_free ( " + names + " ) ;").c_str())) return gMalloc; if (Token::simpleMatch(tok, std::string("fclose ( " + names + " )").c_str()) || Token::simpleMatch(tok, "fcloseall ( )")) return File; if (Token::simpleMatch(tok, std::string("close ( " + names + " )").c_str())) return Fd; if (Token::simpleMatch(tok, std::string("pclose ( " + names + " )").c_str())) return Pipe; if (Token::simpleMatch(tok, std::string("closedir ( " + names + " )").c_str())) return Dir; return No; } //-------------------------------------------------------------------------- //-------------------------------------------------------------------------- void CheckMemoryLeak::memoryLeak(const Token *tok, const std::string &varname, AllocType alloctype) { if (alloctype == CheckMemoryLeak::File || alloctype == CheckMemoryLeak::Pipe || alloctype == CheckMemoryLeak::Fd || alloctype == CheckMemoryLeak::Dir) resourceLeakError(tok, varname.c_str()); else memleakError(tok, varname.c_str()); } //--------------------------------------------------------------------------- void CheckMemoryLeak::reportErr(const Token *tok, Severity::e severity, const std::string &id, const std::string &msg) const { std::list callstack; if (tok) callstack.push_back(tok); reportErr(callstack, severity, id, msg); } void CheckMemoryLeak::reportErr(const std::list &callstack, Severity::e severity, const std::string &id, const std::string &msg) const { std::list locations; for (std::list::const_iterator it = callstack.begin(); it != callstack.end(); ++it) { const Token * const tok = *it; ErrorLogger::ErrorMessage::FileLocation loc; loc.line = tok->linenr(); loc.file = tokenizer->file(tok); locations.push_back(loc); } const ErrorLogger::ErrorMessage errmsg(locations, Severity::stringify(severity), msg, id); if (errorLogger) errorLogger->reportErr(errmsg); else std::cout << errmsg.toXML() << std::endl; } void CheckMemoryLeak::memleakError(const Token *tok, const std::string &varname) { reportErr(tok, Severity::error, "memleak", "Memory leak: " + varname); } void CheckMemoryLeak::memleakUponReallocFailureError(const Token *tok, const std::string &varname) { reportErr(tok, Severity::error, "memleakOnRealloc", "Memory leak: \"" + varname + "\" nulled but not freed upon failure"); } void CheckMemoryLeak::resourceLeakError(const Token *tok, const std::string &varname) { std::string errmsg("Resource leak"); if (!varname.empty()) errmsg += ": " + varname; reportErr(tok, Severity::error, "resourceLeak", errmsg); } void CheckMemoryLeak::deallocDeallocError(const Token *tok, const std::string &varname) { reportErr(tok, Severity::error, "deallocDealloc", "Deallocating a deallocated pointer: " + varname); } void CheckMemoryLeak::deallocuseError(const Token *tok, const std::string &varname) { reportErr(tok, Severity::error, "deallocuse", "Dereferencing '" + varname + "' after it is deallocated / released"); } void CheckMemoryLeak::mismatchSizeError(const Token *tok, const std::string &sz) { reportErr(tok, Severity::error, "mismatchSize", "The given size " + sz + " is mismatching"); } void CheckMemoryLeak::mismatchAllocDealloc(const std::list &callstack, const std::string &varname) { reportErr(callstack, Severity::error, "mismatchAllocDealloc", "Mismatching allocation and deallocation: " + varname); } CheckMemoryLeak::AllocType CheckMemoryLeak::functionReturnType(const Token *tok) const { // Locate the start of the function.. unsigned int parlevel = 0; while (tok) { if (tok->str() == "{" || tok->str() == "}") return No; if (tok->str() == "(") { if (parlevel != 0) return No; ++parlevel; } else if (tok->str() == ")") { if (parlevel != 1) return No; break; } tok = tok->next(); } // Is this the start of a function? if (!Token::Match(tok, ") const| {")) return No; while (tok->str() != "{") tok = tok->next(); // Get return pointer.. unsigned int varid = 0; unsigned int indentlevel = 0; for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "{") ++indentlevel; else if (tok2->str() == "}") { if (indentlevel <= 1) return No; } if (Token::Match(tok2, "return %var% ;")) { if (indentlevel != 1) return No; varid = tok2->next()->varId(); break; } else if (tok2->str() == "return") { AllocType allocType = getAllocationType(tok2->next(), 0); if (allocType != No) return allocType; allocType = getReallocationType(tok2->next(), 0); if (allocType != No) return allocType; } } // Not returning pointer value.. if (varid == 0) return No; // Check if return pointer is allocated.. AllocType allocType = No; while (0 != (tok = tok->next())) { if (Token::Match(tok, "%varid% =", varid)) { allocType = getAllocationType(tok->tokAt(2), varid); if (allocType == No) { allocType = getReallocationType(tok->tokAt(2), varid); } if (allocType != No) return allocType; } if (tok->str() == "return") return allocType; } return No; } void CheckMemoryLeakInFunction::parse_noreturn() { noreturn.insert("exit"); noreturn.insert("_exit"); noreturn.insert("_Exit"); noreturn.insert("abort"); noreturn.insert("err"); noreturn.insert("verr"); noreturn.insert("errx"); noreturn.insert("verrx"); for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() == "{") tok = tok->link(); if (tok->str() == "(") { const std::string function_name((tok->previous() && tok->previous()->isName()) ? tok->strAt(-1).c_str() : ""); tok = tok->link(); if (!function_name.empty() && Token::simpleMatch(tok, ") {")) { // parse this function to check if it contains an "exit" call.. unsigned int indentlevel = 0; for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) { if (tok2->str() == "{") ++indentlevel; else if (tok2->str() == "}") { if (indentlevel <= 1) break; --indentlevel; } if (Token::Match(tok2, "[;{}] exit (")) { noreturn.insert(function_name); break; } } } } } } bool CheckMemoryLeakInFunction::matchFunctionsThatReturnArg(const Token *tok, unsigned int varid) const { return Token::Match(tok, "; %varid% = strcat|memcpy|memmove|strcpy ( %varid% ,", varid); } bool CheckMemoryLeakInFunction::notvar(const Token *tok, unsigned int varid, bool endpar) const { const std::string end(endpar ? " &&|)" : " [;)&|]"); return bool(Token::Match(tok, ("! %varid%" + end).c_str(), varid) || Token::Match(tok, ("! ( %varid% )" + end).c_str(), varid)); } static int countParameters(const Token *tok) { if (!Token::Match(tok, "%var% (")) return -1; if (Token::Match(tok->tokAt(2), "void| )")) return 0; int numpar = 1; int parlevel = 0; for (; tok; tok = tok->next()) { if (tok->str() == "(") ++parlevel; else if (tok->str() == ")") { if (parlevel <= 1) return numpar; --parlevel; } else if (parlevel == 1 && tok->str() == ",") ++numpar; } return -1; } bool CheckMemoryLeakInFunction::test_white_list(const std::string &funcname) { return (std::bsearch(funcname.c_str(), call_func_white_list, sizeof(call_func_white_list) / sizeof(call_func_white_list[0]), sizeof(call_func_white_list[0]), call_func_white_list_compare) != NULL); } const char * CheckMemoryLeakInFunction::call_func(const Token *tok, std::list callstack, const unsigned int varid, AllocType &alloctype, AllocType &dealloctype, unsigned int sz) { if (test_white_list(tok->str())) return 0; if (noreturn.find(tok->str()) != noreturn.end()) return "exit"; if (varid > 0 && (getAllocationType(tok, varid) != No || getReallocationType(tok, varid) != No || getDeallocationType(tok, varid) != No)) return 0; if (callstack.size() > 2) return "dealloc_"; const std::string funcname(tok->str()); for (std::list::const_iterator it = callstack.begin(); it != callstack.end(); ++it) { if ((*it) && (*it)->str() == funcname) return "recursive"; } callstack.push_back(tok); // lock/unlock.. if (varid == 0) { const Token *ftok = _tokenizer->getFunctionTokenByName(funcname.c_str()); while (ftok && (ftok->str() != "{")) ftok = ftok->next(); if (!ftok) return 0; Token *func = getcode(ftok->tokAt(1), callstack, 0, alloctype, dealloctype, false, 1); simplifycode(func); const char *ret = 0; if (Token::simpleMatch(func, "; alloc ; }")) ret = "alloc"; else if (Token::simpleMatch(func, "; dealloc ; }")) ret = "dealloc"; Tokenizer::deleteTokens(func); return ret; } // Check if this is a function that allocates memory.. { const Token *ftok = _tokenizer->getFunctionTokenByName(funcname.c_str()); AllocType a = functionReturnType(ftok); if (a != No) { if (alloctype == No) alloctype = a; else if (alloctype != a) alloctype = Many; return "alloc"; } } // how many parameters is there in the function call? int numpar = countParameters(tok); if (numpar <= 0) return "callfunc"; int par = 1; int parlevel = 0; const bool dot(tok->previous()->str() == "."); for (; tok; tok = tok->next()) { if (tok->str() == "(") ++parlevel; else if (tok->str() == ")") { --parlevel; if (parlevel < 1) { return (_settings && _settings->inconclusive) ? 0 : "callfunc"; } } if (parlevel == 1) { if (tok->str() == ",") ++par; if (varid > 0 && Token::Match(tok, "[,()] %varid% [,()]", varid)) { if (dot) return "use"; const Token *ftok = _tokenizer->getFunctionTokenByName(funcname.c_str()); if (!ftok) return "use"; // how many parameters does the function want? if (numpar != countParameters(ftok)) return "recursive"; const char *parname = Tokenizer::getParameterName(ftok, par); if (! parname) return "recursive"; unsigned int parameterVarid = 0; { const Token *partok = Token::findmatch(ftok, parname); if (partok) parameterVarid = partok->varId(); } if (parameterVarid == 0) return "recursive"; // Check if the function deallocates the variable.. while (ftok && (ftok->str() != "{")) ftok = ftok->next(); Token *func = getcode(ftok->tokAt(1), callstack, parameterVarid, alloctype, dealloctype, false, sz); //simplifycode(func, all); const Token *func_ = func; while (func_ && func_->str() == ";") func_ = func_->next(); const char *ret = 0; /** @todo handle "goto" */ if (Token::findmatch(func_, "dealloc")) ret = "dealloc"; else if (Token::findmatch(func_, "use")) ret = "use"; else if (Token::findmatch(func_, "&use")) ret = "&use"; Tokenizer::deleteTokens(func); return ret; } } } return NULL; } Token *CheckMemoryLeakInFunction::getcode(const Token *tok, std::list callstack, const unsigned int varid, CheckMemoryLeak::AllocType &alloctype, CheckMemoryLeak::AllocType &dealloctype, bool classmember, unsigned int sz) { Token *rethead = 0, *rettail = 0; #define addtoken(_str) \ { \ if (rettail) \ { \ rettail->insertToken(_str); \ rettail = rettail->next(); \ } \ else \ { \ rethead = new Token(0); \ rettail = rethead; \ rettail->str(_str); \ } \ \ rettail->linenr( tok->linenr() ); \ rettail->fileIndex( tok->fileIndex() ); \ } // The first token should be ";" addtoken(";"); bool isloop = false; int indentlevel = 0; int parlevel = 0; for (; tok; tok = tok->next()) { if (tok->str() == "{") { addtoken("{"); ++indentlevel; } else if (tok->str() == "}") { addtoken("}"); if (indentlevel <= 0) break; --indentlevel; } if (tok->str() == "(") ++parlevel; else if (tok->str() == ")") --parlevel; isloop &= (parlevel > 0); if (parlevel == 0 && tok->str() == ";") addtoken(";"); if (varid == 0) { if (!callstack.empty() && Token::Match(tok, "[;{}] __cppcheck_lock|__cppcheck_unlock ( ) ;")) { // Type of leak = Resource leak alloctype = dealloctype = CheckMemoryLeak::File; if (tok->next()->str() == "__cppcheck_lock") { addtoken("alloc"); } else { addtoken("dealloc"); } tok = tok->tokAt(3); continue; } if (Token::simpleMatch(tok, "if (")) { addtoken("if"); tok = tok->next()->link(); continue; } } else { // var = strcpy|.. ( var , if (Token::Match(tok, "[;{}] %varid% = memcpy|memmove|memset|strcpy|strncpy|strcat|strncat ( %varid% ,", varid)) { tok = tok->tokAt(4)->link(); continue; } if (Token::Match(tok->previous(), "[(;{}] %varid% =", varid) || Token::Match(tok, "asprintf ( & %varid% ,", varid)) { CheckMemoryLeak::AllocType alloc; if (Token::simpleMatch(tok, "asprintf (")) { // todo: check how the return value is used. if (!Token::Match(tok->previous(), "[;{}]")) { Tokenizer::deleteTokens(rethead); return 0; } alloc = Malloc; tok = tok->next()->link(); } else { alloc = getAllocationType(tok->tokAt(2), varid); } bool realloc = false; if (sz > 1 && Token::Match(tok->tokAt(2), "malloc ( %num% )") && (MathLib::toLongNumber(tok->strAt(4)) % sz) != 0) { mismatchSizeError(tok->tokAt(4), tok->strAt(4)); } if (alloc == CheckMemoryLeak::No) { alloc = getReallocationType(tok->tokAt(2), varid); if (alloc != CheckMemoryLeak::No) { addtoken("realloc"); addtoken(";"); realloc = true; tok = tok->tokAt(2); continue; } } // don't check classes.. if (alloc == CheckMemoryLeak::New) { if (Token::Match(tok->tokAt(2), "new %type% [(;]")) { if (isclass(_tokenizer, tok->tokAt(3))) { alloc = No; } } } if (alloc != No) { if (! realloc) addtoken("alloc"); if (alloctype != No && alloctype != alloc) alloc = Many; if (alloc != Many && dealloctype != No && dealloctype != Many && dealloctype != alloc) { callstack.push_back(tok); mismatchAllocDealloc(callstack, Token::findmatch(_tokenizer->tokens(), "%varid%", varid)->str()); callstack.pop_back(); } alloctype = alloc; } // assignment.. else { // is the pointer in rhs? bool rhs = false; for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == ";") break; if (Token::Match(tok2, "[=+] %varid%", varid)) { rhs = true; break; } } addtoken((rhs ? "use" : "assign")); } } if (Token::Match(tok->previous(), "[;{})=] %var%") || Token::Match(tok->previous(), "|= %var%")) { AllocType dealloc = getDeallocationType(tok, varid); if (dealloc != No && tok->str() == "fcloseall" && alloctype != dealloc) dealloc = No; else if (dealloc != No) { addtoken("dealloc"); if (dealloctype != No && dealloctype != dealloc) dealloc = Many; if (dealloc != Many && alloctype != No && alloctype != Many && alloctype != dealloc) { callstack.push_back(tok); mismatchAllocDealloc(callstack, Token::findmatch(_tokenizer->tokens(), "%varid%", varid)->str()); callstack.pop_back(); } dealloctype = dealloc; continue; } } // if else switch if (tok->str() == "if") { if (alloctype == Fd) { if (Token::Match(tok, "if ( 0 <= %varid% )", varid) || Token::Match(tok, "if ( %varid% != -1 )", varid)) { addtoken("if(var)"); tok = tok->next()->link(); continue; } else if (Token::Match(tok, "if ( %varid% == -1 )", varid) || Token::Match(tok, "if ( %varid% < 0 )", varid)) { addtoken("if(!var)"); tok = tok->next()->link(); continue; } } if (Token::Match(tok, "if ( %varid% )", varid)) { addtoken("if(var)"); // Make sure the "use" will not be added tok = tok->next()->link(); } else if (Token::simpleMatch(tok, "if (") && notvar(tok->tokAt(2), varid, true)) { addtoken("if(!var)"); } else { // Check if the condition depends on var somehow.. bool dep = false; int innerParlevel = 0; for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "(") ++innerParlevel; if (tok2->str() == ")") { --innerParlevel; if (innerParlevel <= 0) break; } if (Token::Match(tok2, "close|pclose|fclose|closedir ( %varid% )", varid)) { addtoken("dealloc"); addtoken(";"); dep = true; break; } if (alloctype == Fd && Token::Match(tok2, "%varid% !=|>=", varid)) { dep = true; } if (innerParlevel > 0 && Token::Match(tok2, "! %varid%", varid)) { dep = true; break; } } if (Token::Match(tok, "if ( ! %varid% &&", varid)) { addtoken("if(!var)"); } else if (tok->next() && tok->next()->link() && Token::Match(tok->next()->link()->tokAt(-3), "&& ! %varid%", varid)) { addtoken("if(!var)"); } else { addtoken((dep ? "ifv" : "if")); } tok = tok->next(); if (tok->link()) tok = tok->link(); } } } if ((tok->str() == "else") || (tok->str() == "switch")) { addtoken(tok->str().c_str()); } else if ((tok->str() == "case")) { addtoken("case"); addtoken(";"); } else if ((tok->str() == "default")) { addtoken("default"); addtoken(";"); } // Loops.. else if ((tok->str() == "for") || (tok->str() == "while")) { isloop = true; if (Token::simpleMatch(tok, "while ( true )") || Token::simpleMatch(tok, "for ( ; ; )")) { addtoken("while1"); tok = tok->next()->link(); continue; } else if (alloctype == Fd && varid) { if (Token::Match(tok, "while ( 0 <= %varid% )", varid) || Token::Match(tok, "while ( %varid% != -1 )", varid)) { addtoken("while(var)"); tok = tok->next()->link(); continue; } else if (Token::Match(tok, "while ( %varid% == -1 )", varid) || Token::Match(tok, "while ( %varid% < 0 )", varid)) { addtoken("while(!var)"); tok = tok->next()->link(); continue; } } else if (varid && Token::Match(tok, "while ( %varid% )", varid)) { addtoken("while(var)"); tok = tok->next()->link(); continue; } else if (varid && Token::simpleMatch(tok, "while (") && notvar(tok->tokAt(2), varid, true)) { addtoken("while(!var)"); tok = tok->next()->link(); continue; } addtoken("loop"); } else if ((tok->str() == "do")) { addtoken("do"); } if (varid > 0 && isloop && notvar(tok, varid)) { addtoken("!var"); } // continue / break.. if (tok->str() == "continue") { addtoken("continue"); } else if (tok->str() == "break") { addtoken("break"); } else if (tok->str() == "goto") { addtoken("goto"); } // Return.. else if (tok->str() == "return") { addtoken("return"); if (varid == 0) { addtoken(";"); while (tok && tok->str() != ";") tok = tok->next(); if (!tok) break; continue; } // Returning a auto_ptr of this allocated variable.. if (Token::simpleMatch(tok->next(), "std :: auto_ptr <")) { const Token *tok2 = tok->tokAt(5); while (tok2 && tok2->str() != ">") tok2 = tok2->next(); if (Token::Match(tok2, "> ( %varid% )", varid)) { addtoken("use"); tok = tok2->tokAt(3); } } else if (varid && Token::Match(tok, "return &| %varid%", varid)) { addtoken("use"); } else if (varid && Token::Match(tok, "return strcpy|strncpy|memcpy ( %varid%", varid)) { addtoken("use"); tok = tok->tokAt(2); } else { for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next()) { if (tok2->str() == ";") break; if (tok2->varId() == varid) { addtoken("use"); tok = tok2; break; } } } } // throw.. else if (Token::Match(tok, "try|throw|catch")) addtoken(tok->strAt(0)); // Assignment.. if (varid) { if (Token::Match(tok, "[)=] %varid% [+;)]", varid) || Token::Match(tok, "%var% + %varid%", varid) || Token::Match(tok, "%varid% +=|-=", varid) || Token::Match(tok, "+=|<< %varid% ;", varid) || Token::Match(tok, "= strcpy|strcat|memmove|memcpy ( %varid% ,", varid)) { addtoken("use"); } else if (Token::Match(tok->previous(), "[;{}=(,+-*/] %varid% [", varid)) { addtoken("use_"); } } // Investigate function calls.. if (Token::Match(tok, "%var% (")) { // A function call should normally be followed by ";" if (Token::simpleMatch(tok->next()->link(), ") {")) { if (!Token::Match(tok, "if|for|while|switch")) { addtoken("exit"); addtoken(";"); tok = tok->next()->link(); continue; } } // Inside class function.. if the var is passed as a parameter then // just add a "::use" // The "::use" means that a member function was probably called but it wasn't analyzed further else if (classmember) { int innerParlevel = 1; for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) { if (tok2->str() == "(") ++innerParlevel; else if (tok2->str() == ")") { --innerParlevel; if (innerParlevel <= 0) break; } if (tok2->varId() == varid) { addtoken("::use"); break; } } } else { if (varid > 0 && Token::Match(tok, "%var% ( close|fclose|pclose ( %varid% ) ) ;", varid)) { addtoken("dealloc"); tok = tok->next()->link(); continue; } const char *str = call_func(tok, callstack, varid, alloctype, dealloctype, sz); if (str) { if (varid == 0) { addtoken(str); } else if (str != std::string("alloc") || Token::Match(tok->tokAt(-2), "%varid% =", varid)) { addtoken(str); } } else if (varid > 0 && getReallocationType(tok, varid) != No && tok->tokAt(2)->varId() == varid) { addtoken("if"); addtoken("{"); addtoken("dealloc"); addtoken(";"); addtoken("}"); tok = tok->next()->link(); continue; } } } // Callback.. bool matchFirst = Token::Match(tok, "( %var%"); if (matchFirst || Token::Match(tok, "( * %var%")) { int tokIdx = matchFirst ? 2 : 3; while (Token::Match(tok->tokAt(tokIdx), ". %var%")) tokIdx += 2; if (Token::simpleMatch(tok->tokAt(tokIdx), ") (")) { for (const Token *tok2 = tok->tokAt(tokIdx + 2); tok2; tok2 = tok2->next()) { if (Token::Match(tok2, "[;{]")) break; else if (tok2->varId() == varid) { addtoken("use"); break; } } } } // Linux lists.. if (varid > 0 && Token::Match(tok, "[=(,] & %varid% [.[,)]", varid)) { addtoken("&use"); } } return rethead; } void CheckMemoryLeakInFunction::simplifycode(Token *tok) { // Replace "throw" that is not in a try block with "return" int indentlevel = 0; int trylevel = -1; for (Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "{") ++indentlevel; else if (tok2->str() == "}") { --indentlevel; if (indentlevel <= trylevel) trylevel = -1; } else if (trylevel == -1 && tok2->str() == "try") trylevel = indentlevel; else if (trylevel == -1 && tok2->str() == "throw") tok2->str("return"); } // reduce "if callfunc {" => "if {" for (Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (Token::Match(tok2, "if|ifv callfunc {")) tok2->deleteNext(); } // remove redundant braces.. for (Token *start = tok; start; start = start->next()) { if (Token::simpleMatch(start, "; {")) { // the "link" doesn't work here. Find the end brace.. unsigned int indent = 0; for (Token *end = start; end; end = end->next()) { if (end->str() == "{") ++indent; else if (end->str() == "}") { if (indent <= 1) { if (indent == 1 && Token::Match(end->previous(), "[;{}] } %any%")) { start->deleteNext(); end->deleteThis(); } break; } --indent; } } } } // reduce the code.. bool done = false; while (! done) { //tok->printOut("simplifycode loop.."); done = true; // simplify "while1" contents.. for (Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (Token::simpleMatch(tok2, "while1 {")) { unsigned int innerIndentlevel = 0; for (Token *tok3 = tok2->tokAt(2); tok3; tok3 = tok3->next()) { if (tok3->str() == "{") ++innerIndentlevel; else if (tok3->str() == "}") { if (innerIndentlevel == 0) break; --innerIndentlevel; } while (innerIndentlevel == 0 && Token::Match(tok3, "[{};] if|ifv|else { continue ; }")) { Token::eraseTokens(tok3, tok3->tokAt(6)); if (Token::simpleMatch(tok3->next(), "else")) tok3->deleteNext(); } } if (Token::Match(tok2, "while1 { if { dealloc ; return ; } }")) { tok2->str(";"); Token::eraseTokens(tok2, tok2->tokAt(4)); Token::eraseTokens(tok2->tokAt(4), tok2->tokAt(7)); } } } for (Token *tok2 = tok; tok2; tok2 = tok2 ? tok2->next() : NULL) { // Delete extra ";" while (Token::Match(tok2, "[;{}] ;")) { tok2->deleteNext(); done = false; } // Replace "{ }" with ";" if (Token::simpleMatch(tok2->next(), "{ }")) { tok2->eraseTokens(tok2, tok2->tokAt(3)); tok2->insertToken(";"); done = false; } // Delete braces around a single instruction.. if (Token::Match(tok2->next(), "{ %var% ; }")) { tok2->deleteNext(); Token::eraseTokens(tok2->tokAt(2), tok2->tokAt(4)); done = false; } if (Token::Match(tok2->next(), "{ %var% %var% ; }")) { tok2->deleteNext(); Token::eraseTokens(tok2->tokAt(3), tok2->tokAt(5)); done = false; } // reduce "; callfunc ; %var%" else if (Token::Match(tok2, "; callfunc ; %type%")) { tok2->deleteNext(); done = false; } // Reduce "if if|callfunc" => "if" else if (Token::Match(tok2, "if if|callfunc")) { tok2->deleteNext(); done = false; } else if (tok2->next() && tok2->next()->str() == "if") { // Delete empty if that is not followed by an else if (Token::Match(tok2->next(), "if ; !!else")) { tok2->deleteNext(); done = false; } // Reduce "if X ; else X ;" => "X ;" else if (Token::Match(tok2->next(), "if %var% ; else %var% ;") && std::string(tok2->strAt(2)) == std::string(tok2->strAt(5))) { Token::eraseTokens(tok2, tok2->tokAt(5)); done = false; } // Two "if alloc ;" after one another.. perhaps only one of them can be executed each time else if (!_settings->inconclusive && Token::Match(tok2, "[;{}] if alloc ; if alloc ;")) { Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } else if (Token::Match(tok2, "; if ; else assign|use ; assign|use") || Token::Match(tok2, "; if assign|use ; else ; assign|use")) { Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } // Reduce "if return ; alloc ;" => "alloc ;" else if (Token::Match(tok2, "[;{}] if return ; alloc|return ;")) { Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } // "[;{}] if alloc ; else return ;" => "[;{}] alloc ;" else if (Token::Match(tok2, "[;{}] if alloc ; else return ;")) { tok2->deleteNext(); // Remove "if" Token::eraseTokens(tok2->next(), tok2->tokAt(5)); // Remove "; else return" done = false; } // Reduce "if ; else %var% ;" => "if %var% ;" else if (Token::Match(tok2->next(), "if ; else %var% ;")) { Token::eraseTokens(tok2->next(), tok2->tokAt(4)); done = false; } // Reduce "if ; else" => "if" else if (Token::simpleMatch(tok2->next(), "if ; else")) { Token::eraseTokens(tok2->next(), tok2->tokAt(4)); done = false; } // Reduce "if return ; else|if return|continue ;" => "if return ;" else if (Token::Match(tok2->next(), "if return ; else|if return|continue|break ;")) { Token::eraseTokens(tok2->tokAt(3), tok2->tokAt(6)); done = false; } // Reduce "if continue|break ; else|if return ;" => "if return ;" else if (Token::Match(tok2->next(), "if continue|break ; if|else return ;")) { Token::eraseTokens(tok2->next(), tok2->tokAt(5)); done = false; } // Delete "if { dealloc|assign|use ; return ; }" else if (Token::Match(tok2, "[;{}] if { dealloc|assign|use ; return ; }")) { Token::eraseTokens(tok2, tok2->tokAt(8)); if (Token::simpleMatch(tok2->next(), "else")) tok2->deleteNext(); done = false; } // Remove "if { dealloc ; callfunc ; } !!else" else if (Token::Match(tok2->next(), "if { dealloc|assign ; callfunc ; } !!else")) { Token::eraseTokens(tok2, tok2->tokAt(8)); done = false; } // Reducing if.. else if (_settings->inconclusive) { if (Token::Match(tok2, "[;{}] if { assign|dealloc|use ; return ; } !!else")) { Token::eraseTokens(tok2, tok2->tokAt(8)); done = false; } } continue; } // Reduce "alloc while(!var) alloc ;" => "alloc ;" if (Token::Match(tok2, "[;{}] alloc ; while(!var) alloc ;")) { Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } // Reduce "ifv return;" => "if return use;" if (Token::simpleMatch(tok2, "ifv return ;")) { tok2->str("if"); tok2->next()->insertToken("use"); done = false; } // Reduce "if(var) dealloc ;" and "if(var) use ;" that is not followed by an else.. if (Token::Match(tok2, "[;{}] if(var) assign|dealloc|use ; !!else")) { Token::eraseTokens(tok2, tok2->tokAt(2)); done = false; } // Reduce "; if(!var) alloc ; !!else" => "; dealloc ; alloc ;" if (Token::Match(tok2, "; if(!var) alloc ; !!else")) { // Remove the "if(!var)" Token::eraseTokens(tok2, tok2->tokAt(2)); // Insert "dealloc ;" before the "alloc ;" tok2->insertToken(";"); tok2->insertToken("dealloc"); done = false; } // Reduce "; if(!var) exit ;" => ";" if (Token::Match(tok2, "; if(!var) exit ;")) { Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Remove "catch ;" if (Token::simpleMatch(tok2->next(), "catch ;")) { Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Reduce "if* ;".. if (Token::Match(tok2->next(), "if(var)|if(!var)|ifv ;")) { // Followed by else.. if (Token::simpleMatch(tok2->tokAt(3), "else")) { tok2 = tok2->next(); if (tok2->str() == "if(var)") tok2->str("if(!var)"); else if (tok2->str() == "if(!var)") tok2->str("if(var)"); // remove the "; else" Token::eraseTokens(tok2, tok2->tokAt(3)); } else { // remove the "if* ;" Token::eraseTokens(tok2, tok2->tokAt(3)); } done = false; } // Reduce "else ;" => ";" if (Token::simpleMatch(tok2->next(), "else ;")) { Token::eraseTokens(tok2, tok2->tokAt(2)); done = false; } // Reduce "while1 ;" => "use ;" if (Token::simpleMatch(tok2, "while1 ;")) { tok2->str("use"); done = false; } // Reduce "while1 if break ;" => ";" if (Token::simpleMatch(tok2, "while1 if break ;")) { tok2->str(";"); Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Delete if block: "alloc; if return use ;" if (Token::Match(tok2, "alloc ; if return use ; !!else")) { Token::eraseTokens(tok2, tok2->tokAt(5)); done = false; } // Reduce "alloc|dealloc|use|callfunc ; exit ;" => "; exit ;" if (Token::Match(tok2, "[;{}] alloc|dealloc|use|callfunc ; exit ;")) { tok2->deleteNext(); done = false; } // Reduce "if loop ; exit ;" => "; exit ;" if (Token::Match(tok2, "if loop ; exit ;")) { tok2->deleteThis(); tok2->deleteThis(); done = false; } // Reduce "alloc|dealloc|use ; if(var) exit ;" if (Token::Match(tok2, "alloc|dealloc|use ; if(var) exit ;")) { tok2->deleteThis(); done = false; } // Remove "if exit ;" if (Token::simpleMatch(tok2, "if exit ;")) { tok2->deleteThis(); tok2->deleteThis(); done = false; } // Remove the "if break|continue ;" that follows "dealloc ; alloc ;" if (! _settings->inconclusive && Token::Match(tok2, "dealloc ; alloc ; if break|continue ;")) { tok2 = tok2->tokAt(3); Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Reduce "do { dealloc ; alloc ; } while(var) ;" => ";" if (Token::simpleMatch(tok2->next(), "do { dealloc ; alloc ; } while(var) ;")) { Token::eraseTokens(tok2, tok2->tokAt(9)); done = false; } // Reduce "do { alloc ; } " => "alloc ;" /** @todo If the loop "do { alloc ; }" can be executed twice, reduce it to "loop alloc ;" */ if (Token::simpleMatch(tok2->next(), "do { alloc ; }")) { Token::eraseTokens(tok2, tok2->tokAt(3)); Token::eraseTokens(tok2->tokAt(2), tok2->tokAt(4)); done = false; } // Reduce "loop break ; => ";" if (Token::Match(tok2->next(), "loop break|continue ;")) { Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Reduce "loop|do ;" => ";" if (Token::Match(tok2, "loop|do ;")) { tok2->deleteThis(); done = false; } // Reduce "loop if break ; => ";" if (Token::Match(tok2->next(), "loop if break|continue ; !!else")) { Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } // Reduce "loop { assign|dealloc|use ; alloc ; if break ; }" to "assign|dealloc|use ; alloc ;" if (Token::Match(tok2->next(), "loop { assign|dealloc|use ; alloc ; if break|continue ; }")) { // erase "loop {" Token::eraseTokens(tok2, tok2->tokAt(3)); // erase "if break|continue ; }" tok2 = tok2->tokAt(4); Token::eraseTokens(tok2, tok2->tokAt(5)); done = false; } // Replace "loop { X ; break ; }" with "X ;" if (Token::Match(tok2->next(), "loop { %var% ; break ; }")) { Token::eraseTokens(tok2, tok2->tokAt(3)); Token::eraseTokens(tok2->tokAt(2), tok2->tokAt(6)); done = false; } // Replace "do ; loop ;" with ";" if (Token::Match(tok2->next(), "%any% ; loop ;")) { if (tok2->next()->str() == "do") tok2->deleteNext(); else tok2 = tok2->next(); Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Replace "do ; loop !var ;" with ";" if (Token::Match(tok2->next(), "%any% ; loop !var ;")) { if (tok2->next()->str() == "do") tok2->deleteNext(); else tok2 = tok2->next(); Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } // Replace "loop if return ;" with "if return ;" if (Token::simpleMatch(tok2->next(), "loop if return")) { Token::eraseTokens(tok2, tok2->tokAt(2)); done = false; } // Delete if block in "alloc ; if(!var) return ;" if (Token::Match(tok2, "alloc ; if(!var) return ;")) { Token::eraseTokens(tok2, tok2->tokAt(4)); done = false; } // Delete if block: "alloc; if return use ;" if (Token::Match(tok2, "alloc ; if return use ; !!else")) { Token::eraseTokens(tok2, tok2->tokAt(5)); done = false; } // Reduce "[;{}] return ; %var%" => "[;{}] return ;" if (Token::Match(tok2, "[;{}] return ; %var%")) { Token::eraseTokens(tok2->tokAt(2), tok2->tokAt(4)); done = false; } // Reduce "[;{}] return use ; %var%" => "[;{}] return use ;" if (Token::Match(tok2, "[;{}] return use ; %var%")) { Token::eraseTokens(tok2->tokAt(3), tok2->tokAt(5)); done = false; } // Reduce "if(var) return use ;" => "return use ;" if (Token::Match(tok2->next(), "if(var) return use ; !!else")) { Token::eraseTokens(tok2, tok2->tokAt(2)); done = false; } // Reduce "if(var) assign|dealloc|use ;" => "assign|dealloc|use ;" if (Token::Match(tok2->next(), "if(var) assign|dealloc|use ; !!else")) { Token::eraseTokens(tok2, tok2->tokAt(2)); done = false; } // malloc - realloc => alloc ; dealloc ; alloc ; // Reduce "[;{}] alloc ; dealloc ; alloc ;" => "[;{}] alloc ;" if (Token::Match(tok2, "[;{}] alloc ; dealloc ; alloc ;")) { Token::eraseTokens(tok2->next(), tok2->tokAt(6)); done = false; } // Delete second use in "use ; use ;" while (Token::Match(tok2, "[;{}] use ; use ;")) { Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Delete first part in "use ; dealloc ;" if (Token::Match(tok2, "[;{}] use ; dealloc ;")) { Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Delete first part in "use ; return use ;" if (Token::Match(tok2, "[;{}] use ; return use ;")) { Token::eraseTokens(tok2, tok2->tokAt(2)); done = false; } // Delete "callfunc ;" that is followed by "use|if|callfunc" // If the function doesn't throw exception or exit the application, then the "callfunc" is not needed if (Token::Match(tok2, "callfunc ; use|if|callfunc")) { tok2->deleteThis(); done = false; } // Delete second case in "case ; case ;" while (Token::simpleMatch(tok2, "case ; case ;")) { Token::eraseTokens(tok2, tok2->tokAt(3)); done = false; } // Replace switch with if (if not complicated) if (Token::simpleMatch(tok2, "switch {")) { // Right now, I just handle if there are a few case and perhaps a default. bool valid = false; bool incase = false; for (const Token * _tok = tok2->tokAt(2); _tok; _tok = _tok->next()) { if (_tok->str() == "{") break; else if (_tok->str() == "}") { valid = true; break; } else if (_tok->str() == "switch") break; else if (_tok->str() == "loop") break; else if (incase && _tok->str() == "case") break; else if (Token::Match(_tok, "return !!;")) break; if (Token::Match(_tok, "if return|break use| ;")) _tok = _tok->tokAt(2); incase |= (_tok->str() == "case"); incase &= (_tok->str() != "break" && _tok->str() != "return"); } if (!incase && valid) { done = false; tok2->str(";"); Token::eraseTokens(tok2, tok2->tokAt(2)); tok2 = tok2->next(); bool first = true; while (Token::Match(tok2, "case|default")) { const bool def(tok2->str() == "default"); tok2->str(first ? "if" : "}"); if (first) { first = false; tok2->insertToken("{"); } else { // Insert "else [if] { tok2->insertToken("{"); if (! def) tok2->insertToken("if"); tok2->insertToken("else"); tok2 = tok2->next(); } while (tok2) { if (tok2->str() == "}") break; if (Token::Match(tok2, "break|return ;")) break; if (Token::Match(tok2, "if return|break use| ;")) tok2 = tok2->tokAt(2); else tok2 = tok2->next(); } if (Token::simpleMatch(tok2, "break ;")) { tok2->str(";"); tok2 = tok2->tokAt(2); } else if (tok2 && tok2->str() == "return") { tok2 = tok2->tokAt(2); } } } } } // If "--all" is given, remove all "callfunc".. if (done && _settings->inconclusive) { for (Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "callfunc") { tok2->deleteThis(); done = false; } } } } } const Token *CheckMemoryLeakInFunction::findleak(const Token *tokens) { const Token *result; if ((result = Token::findmatch(tokens, "loop alloc ;")) != NULL) { return result; } if (Token::Match(tokens, "alloc ; if|if(var)|ifv break|continue|return ;")) { return tokens->tokAt(3); } if ((result = Token::findmatch(tokens, "alloc ; if|if(var)|ifv return ;")) != NULL) { return result->tokAt(3); } if ((result = Token::findmatch(tokens, "alloc ; alloc|assign|return callfunc| ;")) != NULL) { return result->tokAt(2); } if ((result = Token::findmatch(tokens, "alloc ; if assign ;")) != NULL) { return result->tokAt(3); } if ((result = Token::findmatch(tokens, "alloc ; }")) != NULL) { if (result->tokAt(3) == NULL) return result->tokAt(2); } // No deallocation / usage => report leak at the last token if (!Token::findmatch(tokens, "dealloc|use")) { const Token *last = tokens; while (last->next()) last = last->next(); // check if we call exit before the end of the funcion Token *tok2 = last->previous(); if (tok2) { if (Token::simpleMatch(tok2, ";")) { const Token *tok3 = tok2->previous(); if (tok3 && Token::simpleMatch(tok3, "exit")) { return NULL; } } } return last; } return NULL; } // Check for memory leaks for a function variable. void CheckMemoryLeakInFunction::checkScope(const Token *Tok1, const std::string &varname, unsigned int varid, bool classmember, unsigned int sz) { std::list callstack; AllocType alloctype = No; AllocType dealloctype = No; const Token *result; Token *tok = getcode(Tok1, callstack, varid, alloctype, dealloctype, classmember, sz); //tok->printOut((std::string("Checkmemoryleak: getcode result for: ") + varname).c_str()); // Simplify the code and check if freed memory is used.. for (Token *tok2 = tok; tok2; tok2 = tok2->next()) { while (Token::Match(tok2, "[;{}] ;")) Token::eraseTokens(tok2, tok2->tokAt(2)); } if ((result = Token::findmatch(tok, "[;{}] dealloc ; use_ ;")) != NULL) { deallocuseError(result->tokAt(3), varname); } // Replace "&use" with "use". Replace "use_" with ";" for (Token *tok2 = tok; tok2; tok2 = tok2->next()) { if (tok2->str() == "&use") tok2->str("use"); else if (tok2->str() == "use_") tok2->str(";"); else if (tok2->str() == "::use") // Some kind of member function usage. Not analyzed very well. tok2->str("use"); else if (tok2->str() == "recursive") tok2->str("use"); else if (tok2->str() == "dealloc_") tok2->str("dealloc"); else if (tok2->str() == "realloc") { tok2->str("dealloc"); tok2->insertToken("alloc"); tok2->insertToken(";"); } } // If the variable is not allocated at all => no memory leak if (Token::findmatch(tok, "alloc") == 0) { Tokenizer::deleteTokens(tok); return; } simplifycode(tok); if (_settings->_debug && _settings->_verbose) { tok->printOut(("Checkmemoryleak: simplifycode result for: " + varname).c_str()); } // If the variable is not allocated at all => no memory leak if (Token::findmatch(tok, "alloc") == 0) { Tokenizer::deleteTokens(tok); return; } /** @todo handle "goto" */ if (Token::findmatch(tok, "goto")) { Tokenizer::deleteTokens(tok); return; } if ((result = findleak(tok)) != NULL) { memoryLeak(result, varname, alloctype); } else if ((result = Token::findmatch(tok, "dealloc ; dealloc ;")) != NULL) { deallocDeallocError(result->tokAt(2), varname); } // detect cases that "simplifycode" don't handle well.. else if (_settings->_debug) { Token *first = tok; while (first && first->str() == ";") first = first->next(); bool noerr = false; noerr |= Token::simpleMatch(first, "alloc ; }"); noerr |= Token::simpleMatch(first, "alloc ; dealloc ; }"); noerr |= Token::simpleMatch(first, "alloc ; return use ; }"); noerr |= Token::simpleMatch(first, "alloc ; use ; }"); noerr |= Token::simpleMatch(first, "alloc ; use ; return ; }"); noerr |= Token::simpleMatch(first, "if alloc ; dealloc ; }"); noerr |= Token::simpleMatch(first, "if alloc ; return use ; }"); noerr |= Token::simpleMatch(first, "if alloc ; use ; }"); noerr |= Token::simpleMatch(first, "alloc ; ifv return ; dealloc ; }"); noerr |= Token::simpleMatch(first, "alloc ; if return ; dealloc; }"); // Unhandled case.. if (! noerr) { std::cout << "Token listing..\n "; for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) std::cout << " " << tok2->str(); std::cout << "\n"; } } Tokenizer::deleteTokens(tok); } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Check for memory leaks due to improper realloc() usage. // Below, "a" may be set to null without being freed if realloc() cannot // allocate the requested memory: // a = malloc(10); a = realloc(a, 100); //--------------------------------------------------------------------------- void CheckMemoryLeakInFunction::checkReallocUsage() { const Token *tok = _tokenizer->tokens(); for (; tok; tok = tok->next()) { if (Token::Match(tok, "%var% = realloc|g_try_realloc ( %var% ,")) { if (tok->varId() == tok->tokAt(4)->varId()) { memleakUponReallocFailureError(tok, tok->str()); } } } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Checks for memory leaks inside function.. //--------------------------------------------------------------------------- void CheckMemoryLeakInFunction::parseFunctionScope(const Token *tok, const Token *tok1, const bool classmember) { // Check locking/unlocking of global resources.. checkScope(tok->next(), "", 0, classmember, 1); // Locate parameters and check their usage.. for (const Token *tok2 = tok1; tok2; tok2 = tok2->next()) { if (tok2 == tok) break; if (tok2->str() == ")") break; if (Token::Match(tok2, "[(,] %type% * %var% [,)]") && tok2->next()->isStandardType()) { const std::string varname(tok2->strAt(3)); const unsigned int varid = tok2->tokAt(3)->varId(); const unsigned int sz = _tokenizer->sizeOfType(tok->next()); checkScope(tok->next(), varname, varid, classmember, sz); } } // Locate variable declarations and check their usage.. unsigned int indentlevel = 0; do { if (tok->str() == "{") ++indentlevel; else if (tok->str() == "}") { if (indentlevel <= 1) break; --indentlevel; } // Skip these weird blocks... "( { ... } )" if (Token::simpleMatch(tok, "( {")) { tok = tok->link(); if (!tok) break; continue; } if (!Token::Match(tok, "[{};] %type%")) continue; // Don't check static/extern variables if (Token::Match(tok->next(), "static|extern")) continue; // return/else is not part of a variable declaration.. if (Token::Match(tok->next(), "return|else")) continue; unsigned int sz = _tokenizer->sizeOfType(tok->next()); if (sz < 1) sz = 1; if (Token::Match(tok, "[{};] %type% * const| %var% [;=]")) { const Token *vartok = tok->tokAt(tok->tokAt(3)->str() != "const" ? 3 : 4); checkScope(tok->next(), vartok->str(), vartok->varId(), classmember, sz); } else if (Token::Match(tok, "[{};] %type% %type% * const| %var% [;=]")) { const Token *vartok = tok->tokAt(tok->tokAt(4)->str() != "const" ? 4 : 5); checkScope(tok->next(), vartok->str(), vartok->varId(), classmember, sz); } else if (Token::Match(tok, "[{};] int %var% [;=]")) { const Token *vartok = tok->tokAt(2); checkScope(tok->next(), vartok->str(), vartok->varId(), classmember, sz); } } while (0 != (tok = tok->next())); } void CheckMemoryLeakInFunction::check() { // Parse the tokens and fill the "noreturn" parse_noreturn(); bool classmember = false; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() == "(") { tok = tok->link(); } // Found a function scope if (Token::Match(tok, ") const| {")) { const Token * const tok1 = tok->link(); while (tok->str() != "{") tok = tok->next(); parseFunctionScope(tok, tok1, classmember); tok = tok->link(); continue; } if (tok->str() == "::") classmember = true; if (Token::Match(tok, "[;}]")) classmember = false; } } //--------------------------------------------------------------------------- //--------------------------------------------------------------------------- // Checks for memory leaks in classes.. //--------------------------------------------------------------------------- void CheckMemoryLeakInClass::check() { for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() == "{") tok = tok->link(); else if (Token::Match(tok, "class %var% [{:]")) { std::vector classname; classname.push_back(tok->strAt(1)); parseClass(tok, classname); } } } void CheckMemoryLeakInClass::parseClass(const Token *tok1, std::vector &classname) { // Go into class. while (tok1 && tok1->str() != "{") tok1 = tok1->next(); tok1 = tok1 ? tok1->next() : 0; // are we parsing the private scope of the class? bool privateScope = true; unsigned int indentlevel = 0; for (const Token *tok = tok1; tok; tok = tok->next()) { if (tok->str() == "{") ++indentlevel; else if (tok->str() == "}") { if (indentlevel == 0) return; --indentlevel; } else if (tok->isName() && tok->str().find(":") != std::string::npos) privateScope = bool(tok->str() == "private:"); // Only parse this particular class.. not subclasses if (indentlevel > 0) continue; // skip static variables.. if (Token::Match(tok, "static %type% * %var% ;")) { tok = tok->tokAt(4); } // Declaring subclass.. recursive checking if (Token::Match(tok, "class %var% [{:]")) { classname.push_back(tok->strAt(1)); parseClass(tok, classname); classname.pop_back(); } // Declaring member variable.. check allocations and deallocations if (Token::Match(tok->previous(), ";|{|}|private:|protected:|public: %type% * %var% ;")) { // allocation but no deallocation of private variables in public function.. if (privateScope && tok->isStandardType()) checkPublicFunctions(tok1, tok->tokAt(2)->varId()); if (!isclass(_tokenizer, tok)) variable(classname.back(), tok->tokAt(2)); } } } void CheckMemoryLeakInClass::variable(const std::string &classname, const Token *tokVarname) { if (!_settings->inconclusive) return; const std::string varname = tokVarname->strAt(0); // Check if member variable has been allocated and deallocated.. CheckMemoryLeak::AllocType Alloc = CheckMemoryLeak::No; CheckMemoryLeak::AllocType Dealloc = CheckMemoryLeak::No; bool allocInConstructor = false; bool deallocInDestructor = false; // Loop through all tokens. Inspect member functions int indent_ = 0; const Token *functionToken = _tokenizer->findClassFunction(_tokenizer->tokens(), classname.c_str(), "~| %var%", indent_); while (functionToken) { const bool constructor(Token::Match(functionToken, (classname + " (").c_str()) || Token::Match(functionToken, (classname + " :: " + classname + " (").c_str())); const bool destructor(functionToken->str() == "~" || functionToken->tokAt(2)->str() == "~"); unsigned int indent = 0; bool initlist = false; for (const Token *tok = functionToken; tok; tok = tok->next()) { if (tok->str() == "{") ++indent; else if (tok->str() == "}") { if (indent <= 1) break; --indent; } else if (indent == 0 && Token::simpleMatch(tok, ") :")) initlist = true; else if (initlist || indent > 0) { if (indent == 0) { if (!Token::Match(tok, (":|, " + varname + " (").c_str())) continue; } // Allocate.. if (indent == 0 || Token::Match(tok, (varname + " =").c_str())) { AllocType alloc = getAllocationType(tok->tokAt((indent > 0) ? 2 : 3), 0); if (alloc != CheckMemoryLeak::No) { if (constructor) allocInConstructor = true; if (Alloc != No && Alloc != alloc) alloc = CheckMemoryLeak::Many; std::list callstack; if (alloc != CheckMemoryLeak::Many && Dealloc != CheckMemoryLeak::No && Dealloc != CheckMemoryLeak::Many && Dealloc != alloc) { callstack.push_back(tok); mismatchAllocDealloc(callstack, classname + "::" + varname); callstack.pop_back(); } Alloc = alloc; } } if (indent == 0) continue; // Deallocate.. const char *varnames[3] = { "var", 0, 0 }; varnames[0] = varname.c_str(); AllocType dealloc = getDeallocationType(tok, varnames); if (dealloc == No) { varnames[0] = "this"; varnames[1] = varname.c_str(); dealloc = getDeallocationType(tok, varnames); } if (dealloc != CheckMemoryLeak::No) { if (destructor) deallocInDestructor = true; // several types of allocation/deallocation? if (Dealloc != CheckMemoryLeak::No && Dealloc != dealloc) dealloc = CheckMemoryLeak::Many; std::list callstack; if (dealloc != CheckMemoryLeak::Many && Alloc != CheckMemoryLeak::No && Alloc != Many && Alloc != dealloc) { callstack.push_back(tok); mismatchAllocDealloc(callstack, classname + "::" + varname); callstack.pop_back(); } Dealloc = dealloc; } // Function call in destructor .. possible deallocation else if (destructor && Token::Match(tok->previous(), "[{};] %var% (")) { if (!std::bsearch(tok->str().c_str(), call_func_white_list, sizeof(call_func_white_list) / sizeof(call_func_white_list[0]), sizeof(call_func_white_list[0]), call_func_white_list_compare)) { return; } } } } functionToken = _tokenizer->Tokenizer::findClassFunction(functionToken->next(), classname.c_str(), "~| %var%", indent_); } if (allocInConstructor && !deallocInDestructor) { memoryLeak(tokVarname, (classname + "::" + varname).c_str(), Alloc); } else if (Alloc != CheckMemoryLeak::No && Dealloc == CheckMemoryLeak::No) { memoryLeak(tokVarname, (classname + "::" + varname).c_str(), Alloc); } } void CheckMemoryLeakInClass::checkPublicFunctions(const Token *classtok, const unsigned int varid) { // Check that public functions deallocate the pointers that they allocate. // There is no checking how these functions are used and therefore it // isn't established if there is real leaks or not. if (!_settings->_checkCodingStyle) return; // Parse public functions.. // If they allocate member variables, they should also deallocate bool publicScope = false; for (const Token *tok = classtok; tok; tok = tok->next()) { if (tok->str() == "{") tok = tok->link(); else if (tok->str() == "}") break; else if (tok->isName() && tok->str().find(":") != std::string::npos) publicScope = bool(tok->str() == "public:"); // scope of public function.. // TODO: parse into any function scope that is not a constructor else if (publicScope && (Token::Match(tok, "void %type% (") || Token::simpleMatch(tok, "operator = ("))) { tok = tok->tokAt(2)->link(); if (Token::Match(tok, ") const| {")) { const Token *tok2 = tok; while (tok2->str() != "{") tok2 = tok2->next(); if (Token::Match(tok2, "{ %varid% =", varid)) { const CheckMemoryLeak::AllocType alloc = getAllocationType(tok2->tokAt(3), varid); if (alloc != CheckMemoryLeak::No) publicAllocationError(tok2, tok2->strAt(1)); } } } } } void CheckMemoryLeakInClass::publicAllocationError(const Token *tok, const std::string &varname) { reportError(tok, Severity::style, "publicAllocationError", "Possible leak in public function. The pointer '" + varname + "' is not deallocated before it is allocated."); } void CheckMemoryLeakStructMember::check() { // This should be in the CheckMemoryLeak base class std::set ignoredFunctions; ignoredFunctions.insert("if"); ignoredFunctions.insert("for"); ignoredFunctions.insert("while"); ignoredFunctions.insert("malloc"); unsigned int indentlevel1 = 0; for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) { if (tok->str() == "{") ++indentlevel1; else if (tok->str() == "}") --indentlevel1; // Locate struct variables.. if (indentlevel1 > 0 && Token::Match(tok, "struct|;|{|} %type% * %var% [=;]")) { const Token * const vartok = tok->tokAt(3); if (vartok->varId() == 0) continue; // Check that struct is allocated.. { const unsigned int varid(vartok->varId()); bool alloc = false; unsigned int indentlevel2 = 0; for (const Token *tok2 = vartok; tok2; tok2 = tok2->next()) { if (tok2->str() == "{") ++indentlevel2; else if (tok2->str() == "}") { if (indentlevel2 == 0) break; --indentlevel2; } else if (Token::Match(tok2, "= %varid% [;=]", varid)) { alloc = false; break; } else if (Token::Match(tok2, "%varid% = malloc|kmalloc (", varid)) { alloc = true; } } if (!alloc) continue; } // Check struct.. unsigned int indentlevel2 = 0; for (const Token *tok2 = vartok; tok2; tok2 = tok2->next()) { if (tok2->str() == "{") ++indentlevel2; else if (tok2->str() == "}") { if (indentlevel2 == 0) break; --indentlevel2; } // Unknown usage of struct /** @todo Check how the struct is used. Only bail out if necessary */ else if (Token::Match(tok2, "[(,] %varid% [,)]", vartok->varId())) break; // Struct member is allocated => check if it is also properly deallocated.. else if (Token::Match(tok2, "%varid% . %var% = malloc|strdup|kmalloc (", vartok->varId())) { const unsigned int structid(vartok->varId()); const unsigned int structmemberid(tok2->tokAt(2)->varId()); // This struct member is allocated.. check that it is deallocated unsigned int indentlevel3 = indentlevel2; for (const Token *tok3 = tok2; tok3; tok3 = tok3->next()) { if (tok3->str() == "{") ++indentlevel3; else if (tok3->str() == "}") { if (indentlevel3 == 0) { memoryLeak(tok3, (vartok->str() + "." + tok2->strAt(2)).c_str(), Malloc); break; } --indentlevel3; } // Deallocating the struct member.. else if (Token::Match(tok3, "free|kfree ( %var% . %varid% )", structmemberid)) { // If the deallocation happens at the base level, don't check this member anymore if (indentlevel3 == 0) break; // deallocating and then returning from function in a conditional block => // skip ahead out of the block bool ret = false; while (tok3) { // debug info const std::string tok3str_(tok3->str()); if (tok3->str() == "return") ret = true; else if (tok3->str() == "{" || tok3->str() == "}") break; tok3 = tok3->next(); } if (!ret || !tok3 || tok3->str() != "}") break; --indentlevel3; continue; } // Deallocating the struct.. else if (indentlevel2 == 0 && Token::Match(tok3, "free|kfree ( %varid% )", structid)) { memoryLeak(tok3, (vartok->str() + "." + tok2->strAt(2)).c_str(), Malloc); break; } // failed allocation => skip code.. else if (Token::Match(tok3, "if ( ! %var% . %varid% )", structmemberid)) { // Goto the ")" tok3 = tok3->next()->link(); // make sure we have ") {".. it should be if (!Token::simpleMatch(tok3, ") {")) break; // Goto the "}" tok3 = tok3->next()->link(); } // succeeded allocation else if (Token::Match(tok3, "if ( %var% . %varid% ) {", structmemberid)) { // goto the ")" tok3 = tok3->next()->link(); // check if the variable is deallocated or returned.. unsigned int indentlevel4 = 0; for (const Token *tok4 = tok3; tok4; tok4 = tok4->next()) { if (tok4->str() == "{") ++indentlevel4; else if (tok4->str() == "}") { --indentlevel4; if (indentlevel4 == 0) break; } else if (Token::Match(tok4, "free|kfree ( %var% . %varid% )", structmemberid)) { break; } } // was there a proper deallocation? if (indentlevel4 > 0) break; } // Returning from function.. else if (tok3->str() == "return") { // Returning from function without deallocating struct member? if (!Token::Match(tok3, "return %varid% ;", structid)) { memoryLeak(tok3, (vartok->str() + "." + tok2->strAt(2)).c_str(), Malloc); } break; } // goto isn't handled well.. bail out even though there might be leaks else if (tok3->str() == "goto") break; // using struct in a function call.. else if (Token::Match(tok3, "%var% (")) { // Calling non-function / function that doesn't deallocate? if (ignoredFunctions.find(tok3->str()) != ignoredFunctions.end()) continue; // Check if the struct is used.. bool deallocated = false; unsigned int parlevel = 0; for (const Token *tok4 = tok3; tok4; tok4 = tok4->next()) { if (tok4->str() == "(") ++parlevel; else if (tok4->str() == ")") { if (parlevel <= 1) break; --parlevel; } if (Token::Match(tok4, "[(,] %varid% [,)]", structid)) { /** @todo check if the function deallocates the memory */ deallocated = true; break; } } if (deallocated) break; } } } } } } } /** @brief Experimental class for detecting memory leaks. The ExecutionPath functionality is used */ class CheckLocalLeaks : public ExecutionPath { public: /** Startup constructor */ CheckLocalLeaks(Check *c) : ExecutionPath(c, 0), allocated(false) { } /** Debugging : print checks */ static void printOut(const std::list &checks) { std::ostringstream ostr; ostr << "CheckLocalLeaks::printOut" << std::endl; for (std::list::const_iterator it = checks.begin(); it != checks.end(); ++it) { CheckLocalLeaks *c = dynamic_cast(*it); if (c) { ostr << std::hex << c << ": varId=" << c->varId << " allocated=" << (c->allocated ? "true" : "false") << std::endl; } } std::cout << ostr.str(); } private: ExecutionPath *copy() { return new CheckLocalLeaks(*this); } /** start checking of given variable */ CheckLocalLeaks(Check *c, unsigned int v, const std::string &s) : ExecutionPath(c, v), allocated(false), varname(s) { } /** is other execution path equal? */ bool is_equal(const ExecutionPath *e) const { const CheckLocalLeaks *c = static_cast(e); return (allocated == c->allocated && varname == c->varname); } /** Is variable allocated? */ bool allocated; /** Name of variable */ const std::string varname; /** no implementation => compiler error if used */ void operator=(const CheckLocalLeaks &); /** Allocation is detected */ static void alloc(std::list &checks, const unsigned int varid) { if (varid == 0) return; std::list::iterator it; for (it = checks.begin(); it != checks.end(); ++it) { CheckLocalLeaks *C = dynamic_cast(*it); if (C && C->varId == varid) C->allocated = true; } } /** Deallocation is detected */ static void dealloc(std::list &checks, const Token *tok) { if (tok->varId() == 0) return; std::list::iterator it; for (it = checks.begin(); it != checks.end(); ++it) { CheckLocalLeaks *C = dynamic_cast(*it); if (C && C->varId == tok->varId()) C->allocated = false; } } /** return */ static void ret(const std::list &checks, const Token *tok) { std::list::const_iterator it; for (it = checks.begin(); it != checks.end(); ++it) { CheckLocalLeaks *C = dynamic_cast(*it); if (C && C->allocated) { CheckMemoryLeakInFunction *checkMemleak = reinterpret_cast(C->owner); if (checkMemleak) { checkMemleak->memleakError(tok, C->varname); break; } } } } /** parse the tokens */ const Token *parse(const Token &tok, std::list &checks) const { //std::cout << "CheckLocalLeaks::parse " << tok.str() << std::endl; //printOut(checks); if (!Token::Match(tok.previous(), "[;{}]")) return &tok; if (Token::Match(&tok, "%type% * %var% ;")) { const Token * vartok = tok.tokAt(2); if (vartok->varId() != 0) checks.push_back(new CheckLocalLeaks(owner, vartok->varId(), vartok->str())); return vartok->next(); } if (Token::Match(&tok, "%var% = new")) { alloc(checks, tok.varId()); // goto end of statement const Token *tok2 = &tok; while (tok2 && tok2->str() != ";") tok2 = tok2->next(); return tok2; } if (Token::Match(&tok, "delete %var% ;")) { dealloc(checks, tok.next()); return tok.tokAt(2); } if (Token::Match(&tok, "delete [ ] %var% ;")) { dealloc(checks, tok.tokAt(3)); return tok.tokAt(4); } if (tok.str() == "return") { ret(checks, &tok); } return &tok; } /** going out of scope - all execution paths end */ void end(const std::list &checks, const Token *tok) const { ret(checks, tok); } }; void CheckMemoryLeakInFunction::localleaks() { // Check this scope.. CheckLocalLeaks c(this); checkExecutionPaths(_tokenizer->tokens(), &c); }