1171 lines
48 KiB
C++
1171 lines
48 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2022 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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#include "checkmemoryleak.h"
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#include "astutils.h"
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#include "errorlogger.h"
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#include "library.h"
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#include "settings.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "tokenize.h"
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#include <algorithm>
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#include <unordered_set>
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#include <utility>
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#include <vector>
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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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CheckMemoryLeakInFunction instance1;
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CheckMemoryLeakInClass instance2;
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CheckMemoryLeakStructMember instance3;
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CheckMemoryLeakNoVar instance4;
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}
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// CWE ID used:
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static const CWE CWE398(398U); // Indicator of Poor Code Quality
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static const CWE CWE401(401U); // Improper Release of Memory Before Removing Last Reference ('Memory Leak')
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static const CWE CWE771(771U); // Missing Reference to Active Allocated Resource
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static const CWE CWE772(772U); // Missing Release of Resource after Effective Lifetime
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/** List of functions that can be ignored when searching for memory leaks.
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* These functions don't take the address of the given pointer
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* This list contains function names with const parameters e.g.: atof(const char *)
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* TODO: This list should be replaced by <leak-ignore/> in .cfg files.
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*/
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static const std::unordered_set<std::string> call_func_white_list = {
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"_open", "_wopen", "access", "adjtime", "asctime_r", "asprintf", "chdir", "chmod", "chown"
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, "creat", "ctime_r", "execl", "execle", "execlp", "execv", "execve", "fchmod", "fcntl"
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, "fdatasync", "fclose", "flock", "fmemopen", "fnmatch", "fopen", "fopencookie", "for", "free"
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, "freopen", "fseeko", "fstat", "fsync", "ftello", "ftruncate", "getgrnam", "gethostbyaddr", "gethostbyname"
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, "getnetbyname", "getopt", "getopt_long", "getprotobyname", "getpwnam", "getservbyname", "getservbyport"
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, "glob", "gmtime", "gmtime_r", "if", "index", "inet_addr", "inet_aton", "inet_network", "initgroups"
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, "ioctl", "link", "localtime_r", "lockf", "lseek", "lstat", "mkdir", "mkfifo", "mknod", "mkstemp"
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, "obstack_printf", "obstack_vprintf", "open", "opendir", "parse_printf_format", "pathconf"
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, "perror", "popen", "posix_fadvise", "posix_fallocate", "pread", "psignal", "pwrite", "read", "readahead"
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, "readdir", "readdir_r", "readlink", "readv", "realloc", "regcomp", "return", "rewinddir", "rindex"
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, "rmdir", "scandir", "seekdir", "setbuffer", "sethostname", "setlinebuf", "sizeof", "strdup"
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, "stat", "stpcpy", "strcasecmp", "stricmp", "strncasecmp", "switch"
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, "symlink", "sync_file_range", "telldir", "tempnam", "time", "typeid", "unlink"
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, "utime", "utimes", "vasprintf", "while", "wordexp", "write", "writev"
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};
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//---------------------------------------------------------------------------
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CheckMemoryLeak::AllocType CheckMemoryLeak::getAllocationType(const Token *tok2, nonneg int varid, std::list<const Function*> *callstack) const
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{
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// What we may have...
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// * var = (char *)malloc(10);
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// * var = new char[10];
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// * var = strdup("hello");
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// * var = strndup("hello", 3);
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if (tok2 && tok2->str() == "(") {
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tok2 = tok2->link();
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tok2 = tok2 ? tok2->next() : nullptr;
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}
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if (!tok2)
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return No;
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if (tok2->str() == "::")
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tok2 = tok2->next();
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if (!tok2->isName())
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return No;
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if (!Token::Match(tok2, "%name% ::|. %type%")) {
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// Using realloc..
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AllocType reallocType = getReallocationType(tok2, varid);
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if (reallocType != No)
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return reallocType;
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if (mTokenizer_->isCPP() && tok2->str() == "new") {
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if (tok2->strAt(1) == "(" && !Token::Match(tok2->next(),"( std| ::| nothrow )"))
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return No;
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if (tok2->astOperand1() && (tok2->astOperand1()->str() == "[" || (tok2->astOperand1()->astOperand1() && tok2->astOperand1()->astOperand1()->str() == "[")))
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return NewArray;
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const Token *typeTok = tok2->next();
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while (Token::Match(typeTok, "%name% :: %name%"))
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typeTok = typeTok->tokAt(2);
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const Scope* classScope = nullptr;
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if (typeTok->type() && typeTok->type()->isClassType()) {
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classScope = typeTok->type()->classScope;
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} else if (typeTok->function() && typeTok->function()->isConstructor()) {
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classScope = typeTok->function()->nestedIn;
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}
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if (classScope && classScope->numConstructors > 0)
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return No;
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return New;
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}
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if (mSettings_->posix()) {
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if (Token::Match(tok2, "open|openat|creat|mkstemp|mkostemp|socket (")) {
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// simple sanity check of function parameters..
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// TODO: Make such check for all these functions
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const int num = numberOfArguments(tok2);
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if (tok2->str() == "open" && num != 2 && num != 3)
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return No;
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// is there a user function with this name?
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if (tok2->function())
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return No;
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return Fd;
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}
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if (Token::simpleMatch(tok2, "popen ("))
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return Pipe;
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}
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// Does tok2 point on a Library allocation function?
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const int alloctype = mSettings_->library.getAllocId(tok2, -1);
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if (alloctype > 0) {
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if (alloctype == mSettings_->library.deallocId("free"))
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return Malloc;
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if (alloctype == mSettings_->library.deallocId("fclose"))
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return File;
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return Library::ismemory(alloctype) ? OtherMem : OtherRes;
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}
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}
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while (Token::Match(tok2,"%name% ::|. %type%"))
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tok2 = tok2->tokAt(2);
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// User function
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const Function* func = tok2->function();
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if (func == nullptr)
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return No;
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// Prevent recursion
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if (callstack && std::find(callstack->cbegin(), callstack->cend(), func) != callstack->cend())
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return No;
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std::list<const Function*> cs;
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if (!callstack)
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callstack = &cs;
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callstack->push_back(func);
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return functionReturnType(func, callstack);
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}
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CheckMemoryLeak::AllocType CheckMemoryLeak::getReallocationType(const Token *tok2, nonneg int varid) const
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{
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// What we may have...
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// * var = (char *)realloc(..;
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if (tok2 && tok2->str() == "(") {
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tok2 = tok2->link();
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tok2 = tok2 ? tok2->next() : nullptr;
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}
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if (!tok2)
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return No;
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if (!Token::Match(tok2, "%name% ("))
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return No;
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const Library::AllocFunc *f = mSettings_->library.getReallocFuncInfo(tok2);
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if (!(f && f->reallocArg > 0 && f->reallocArg <= numberOfArguments(tok2)))
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return No;
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const auto args = getArguments(tok2);
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if (args.size() < (f->reallocArg))
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return No;
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const Token* arg = args.at(f->reallocArg - 1);
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while (arg && arg->isCast())
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arg = arg->astOperand1();
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while (arg && arg->isUnaryOp("*"))
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arg = arg->astOperand1();
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if (varid > 0 && !Token::Match(arg, "%varid% [,)]", varid))
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return No;
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const int realloctype = mSettings_->library.getReallocId(tok2, -1);
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if (realloctype > 0) {
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if (realloctype == mSettings_->library.deallocId("free"))
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return Malloc;
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if (realloctype == mSettings_->library.deallocId("fclose"))
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return File;
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return Library::ismemory(realloctype) ? OtherMem : OtherRes;
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}
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return No;
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}
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CheckMemoryLeak::AllocType CheckMemoryLeak::getDeallocationType(const Token *tok, nonneg int varid) const
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{
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if (mTokenizer_->isCPP() && tok->str() == "delete" && tok->astOperand1()) {
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const Token* vartok = tok->astOperand1();
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if (Token::Match(vartok, ".|::"))
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vartok = vartok->astOperand2();
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if (vartok && vartok->varId() == varid) {
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if (tok->strAt(1) == "[")
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return NewArray;
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return New;
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}
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}
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if (tok->str() == "::")
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tok = tok->next();
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if (Token::Match(tok, "%name% (")) {
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if (Token::simpleMatch(tok, "fcloseall ( )"))
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return File;
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int argNr = 1;
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for (const Token* tok2 = tok->tokAt(2); tok2; tok2 = tok2->nextArgument()) {
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const Token* vartok = tok2;
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while (Token::Match(vartok, "%name% .|::"))
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vartok = vartok->tokAt(2);
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if (Token::Match(vartok, "%varid% )|,|-", varid)) {
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if (tok->str() == "realloc" && Token::simpleMatch(vartok->next(), ", 0 )"))
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return Malloc;
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if (mSettings_->posix()) {
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if (tok->str() == "close")
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return Fd;
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if (tok->str() == "pclose")
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return Pipe;
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}
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// Does tok point on a Library deallocation function?
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const int dealloctype = mSettings_->library.getDeallocId(tok, argNr);
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if (dealloctype > 0) {
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if (dealloctype == mSettings_->library.deallocId("free"))
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return Malloc;
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if (dealloctype == mSettings_->library.deallocId("fclose"))
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return File;
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return Library::ismemory(dealloctype) ? OtherMem : OtherRes;
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}
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}
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argNr++;
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}
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}
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return No;
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}
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bool CheckMemoryLeak::isReopenStandardStream(const Token *tok) const
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{
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if (getReallocationType(tok, 0) == File) {
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const Library::AllocFunc *f = mSettings_->library.getReallocFuncInfo(tok);
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if (f && f->reallocArg > 0 && f->reallocArg <= numberOfArguments(tok)) {
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const Token* arg = getArguments(tok).at(f->reallocArg - 1);
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if (Token::Match(arg, "stdin|stdout|stderr"))
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return true;
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}
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}
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return false;
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}
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bool CheckMemoryLeak::isOpenDevNull(const Token *tok) const
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{
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if (mSettings_->posix() && tok->str() == "open" && numberOfArguments(tok) == 2) {
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const Token* arg = getArguments(tok).at(0);
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if (Token::simpleMatch(arg, "\"/dev/null\""))
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return true;
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}
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return false;
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}
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//--------------------------------------------------------------------------
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//--------------------------------------------------------------------------
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void CheckMemoryLeak::memoryLeak(const Token *tok, const std::string &varname, AllocType alloctype) const
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{
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if (alloctype == CheckMemoryLeak::File ||
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alloctype == CheckMemoryLeak::Pipe ||
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alloctype == CheckMemoryLeak::Fd ||
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alloctype == CheckMemoryLeak::OtherRes)
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resourceLeakError(tok, varname);
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else
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memleakError(tok, varname);
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}
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//---------------------------------------------------------------------------
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void CheckMemoryLeak::reportErr(const Token *tok, Severity::SeverityType severity, const std::string &id, const std::string &msg, const CWE &cwe) const
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{
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std::list<const Token *> callstack;
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if (tok)
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callstack.push_back(tok);
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reportErr(callstack, severity, id, msg, cwe);
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}
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void CheckMemoryLeak::reportErr(const std::list<const Token *> &callstack, Severity::SeverityType severity, const std::string &id, const std::string &msg, const CWE &cwe) const
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{
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const ErrorMessage errmsg(callstack, mTokenizer_ ? &mTokenizer_->list : nullptr, severity, id, msg, cwe, Certainty::normal);
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if (mErrorLogger_)
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mErrorLogger_->reportErr(errmsg);
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else
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Check::reportError(errmsg);
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}
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void CheckMemoryLeak::memleakError(const Token *tok, const std::string &varname) const
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{
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reportErr(tok, Severity::error, "memleak", "$symbol:" + varname + "\nMemory leak: $symbol", CWE(401U));
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}
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void CheckMemoryLeak::memleakUponReallocFailureError(const Token *tok, const std::string &reallocfunction, const std::string &varname) const
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{
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reportErr(tok, Severity::error, "memleakOnRealloc", "$symbol:" + varname + "\nCommon " + reallocfunction + " mistake: \'$symbol\' nulled but not freed upon failure", CWE(401U));
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}
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void CheckMemoryLeak::resourceLeakError(const Token *tok, const std::string &varname) const
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{
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std::string errmsg("Resource leak");
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if (!varname.empty())
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errmsg = "$symbol:" + varname + '\n' + errmsg + ": $symbol";
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reportErr(tok, Severity::error, "resourceLeak", errmsg, CWE(775U));
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}
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void CheckMemoryLeak::deallocDeallocError(const Token *tok, const std::string &varname) const
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{
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reportErr(tok, Severity::error, "deallocDealloc", "$symbol:" + varname + "\nDeallocating a deallocated pointer: $symbol", CWE(415U));
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}
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void CheckMemoryLeak::deallocuseError(const Token *tok, const std::string &varname) const
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{
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reportErr(tok, Severity::error, "deallocuse", "$symbol:" + varname + "\nDereferencing '$symbol' after it is deallocated / released", CWE(416U));
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}
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void CheckMemoryLeak::mismatchSizeError(const Token *tok, const std::string &sz) const
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{
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reportErr(tok, Severity::error, "mismatchSize", "The allocated size " + sz + " is not a multiple of the underlying type's size.", CWE(131U));
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}
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void CheckMemoryLeak::mismatchAllocDealloc(const std::list<const Token *> &callstack, const std::string &varname) const
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{
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reportErr(callstack, Severity::error, "mismatchAllocDealloc", "$symbol:" + varname + "\nMismatching allocation and deallocation: $symbol", CWE(762U));
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}
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CheckMemoryLeak::AllocType CheckMemoryLeak::functionReturnType(const Function* func, std::list<const Function*> *callstack) const
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{
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if (!func || !func->hasBody() || !func->functionScope)
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return No;
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// Get return pointer..
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const Variable* var = nullptr;
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for (const Token *tok2 = func->functionScope->bodyStart; tok2 != func->functionScope->bodyEnd; tok2 = tok2->next()) {
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if (const Token *endOfLambda = findLambdaEndToken(tok2))
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tok2 = endOfLambda;
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if (tok2->str() == "{" && !tok2->scope()->isExecutable())
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tok2 = tok2->link();
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if (tok2->str() == "return") {
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const AllocType allocType = getAllocationType(tok2->next(), 0, callstack);
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if (allocType != No)
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return allocType;
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if (tok2->scope() != func->functionScope || !tok2->astOperand1())
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return No;
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const Token* tok = tok2->astOperand1();
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if (Token::Match(tok, ".|::"))
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tok = tok->astOperand2() ? tok->astOperand2() : tok->astOperand1();
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if (tok)
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var = tok->variable();
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break;
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}
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}
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// Not returning pointer value..
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if (!var)
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return No;
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// If variable is not local then alloctype shall be "No"
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// Todo: there can be false negatives about mismatching allocation/deallocation.
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// => Generate "alloc ; use ;" if variable is not local?
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if (!var->isLocal() || var->isStatic())
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return No;
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// Check if return pointer is allocated..
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AllocType allocType = No;
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nonneg int const varid = var->declarationId();
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for (const Token* tok = func->functionScope->bodyStart; tok != func->functionScope->bodyEnd; tok = tok->next()) {
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if (Token::Match(tok, "%varid% =", varid)) {
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allocType = getAllocationType(tok->tokAt(2), varid, callstack);
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}
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if (Token::Match(tok, "= %varid% ;", varid)) {
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return No;
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}
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if (!mTokenizer_->isC() && Token::Match(tok, "[(,] %varid% [,)]", varid)) {
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return No;
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}
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if (Token::Match(tok, "[(,] & %varid% [.,)]", varid)) {
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return No;
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}
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if (Token::Match(tok, "[;{}] %varid% .", varid)) {
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return No;
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}
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if (allocType == No && tok->str() == "return")
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return No;
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}
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return allocType;
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}
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static bool notvar(const Token *tok, nonneg int varid)
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{
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if (!tok)
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return false;
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if (Token::Match(tok, "&&|;"))
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return notvar(tok->astOperand1(),varid) || notvar(tok->astOperand2(),varid);
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if (tok->str() == "(" && Token::Match(tok->astOperand1(), "UNLIKELY|LIKELY"))
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return notvar(tok->astOperand2(), varid);
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const Token *vartok = astIsVariableComparison(tok, "==", "0");
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return vartok && (vartok->varId() == varid);
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}
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static bool ifvar(const Token *tok, nonneg int varid, const std::string &comp, const std::string &rhs)
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{
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if (!Token::simpleMatch(tok, "if ("))
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return false;
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const Token *condition = tok->next()->astOperand2();
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if (condition && condition->str() == "(" && Token::Match(condition->astOperand1(), "UNLIKELY|LIKELY"))
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condition = condition->astOperand2();
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if (!condition || condition->str() == "&&")
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return false;
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const Token *vartok = astIsVariableComparison(condition, comp, rhs);
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return (vartok && vartok->varId() == varid);
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}
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|
|
bool CheckMemoryLeakInFunction::test_white_list(const std::string &funcname, const Settings *settings, bool cpp)
|
|
{
|
|
return ((call_func_white_list.find(funcname)!=call_func_white_list.end()) || settings->library.isLeakIgnore(funcname) || (cpp && funcname == "delete"));
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// 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()
|
|
{
|
|
// only check functions
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
|
|
// Search for the "var = realloc(var, 100" pattern within this function
|
|
for (const Token *tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (tok->varId() > 0 && Token::Match(tok, "%name% =")) {
|
|
// Get the parenthesis in "realloc("
|
|
const Token* parTok = tok->next()->astOperand2();
|
|
// Skip casts
|
|
while (parTok && parTok->isCast())
|
|
parTok = parTok->astOperand1();
|
|
if (!parTok)
|
|
continue;
|
|
|
|
const Token *const reallocTok = parTok->astOperand1();
|
|
if (!reallocTok)
|
|
continue;
|
|
const Library::AllocFunc* f = mSettings->library.getReallocFuncInfo(reallocTok);
|
|
if (!(f && f->arg == -1 && mSettings->library.isnotnoreturn(reallocTok)))
|
|
continue;
|
|
|
|
const AllocType allocType = getReallocationType(reallocTok, tok->varId());
|
|
if (!((allocType == Malloc || allocType == OtherMem)))
|
|
continue;
|
|
const Token* arg = getArguments(reallocTok).at(f->reallocArg - 1);
|
|
while (arg && arg->isCast())
|
|
arg = arg->astOperand1();
|
|
const Token* tok2 = tok;
|
|
while (arg && arg->isUnaryOp("*") && tok2 && tok2->astParent() && tok2->astParent()->isUnaryOp("*")) {
|
|
arg = arg->astOperand1();
|
|
tok2 = tok2->astParent();
|
|
}
|
|
|
|
if (!arg || !tok2)
|
|
continue;
|
|
|
|
if (!(tok->varId() == arg->varId() && tok->variable() && !tok->variable()->isArgument()))
|
|
continue;
|
|
|
|
// Check that another copy of the pointer wasn't saved earlier in the function
|
|
if (Token::findmatch(scope->bodyStart, "%name% = %varid% ;", tok, tok->varId()) ||
|
|
Token::findmatch(scope->bodyStart, "[{};] %varid% = *| %var% .| %var%| [;=]", tok, tok->varId()))
|
|
continue;
|
|
|
|
// Check if the argument is known to be null, which means it is not a memory leak
|
|
if (arg->hasKnownIntValue() && arg->getKnownIntValue() == 0) {
|
|
continue;
|
|
}
|
|
|
|
const Token* tokEndRealloc = reallocTok->linkAt(1);
|
|
// Check that the allocation isn't followed immediately by an 'if (!var) { error(); }' that might handle failure
|
|
if (Token::simpleMatch(tokEndRealloc->next(), "; if (") &&
|
|
notvar(tokEndRealloc->tokAt(3)->astOperand2(), tok->varId())) {
|
|
const Token* tokEndBrace = tokEndRealloc->linkAt(3)->linkAt(1);
|
|
if (tokEndBrace && mTokenizer->isScopeNoReturn(tokEndBrace))
|
|
continue;
|
|
}
|
|
|
|
memleakUponReallocFailureError(tok, reallocTok->str(), tok->str());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
//---------------------------------------------------------------------------
|
|
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Checks for memory leaks in classes..
|
|
//---------------------------------------------------------------------------
|
|
|
|
|
|
void CheckMemoryLeakInClass::check()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
// only check classes and structures
|
|
for (const Scope * scope : symbolDatabase->classAndStructScopes) {
|
|
for (const Variable &var : scope->varlist) {
|
|
if (!var.isStatic() && (var.isPointer() || var.isPointerArray())) {
|
|
// allocation but no deallocation of private variables in public function..
|
|
const Token *tok = var.typeStartToken();
|
|
// Either it is of standard type or a non-derived type
|
|
if (tok->isStandardType() || (var.type() && var.type()->derivedFrom.empty())) {
|
|
if (var.isPrivate())
|
|
checkPublicFunctions(scope, var.nameToken());
|
|
|
|
variable(scope, var.nameToken());
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void CheckMemoryLeakInClass::variable(const Scope *scope, const Token *tokVarname)
|
|
{
|
|
const std::string& varname = tokVarname->str();
|
|
const int varid = tokVarname->varId();
|
|
const std::string& classname = scope->className;
|
|
|
|
// Check if member variable has been allocated and deallocated..
|
|
CheckMemoryLeak::AllocType memberAlloc = CheckMemoryLeak::No;
|
|
CheckMemoryLeak::AllocType memberDealloc = CheckMemoryLeak::No;
|
|
|
|
bool allocInConstructor = false;
|
|
bool deallocInDestructor = false;
|
|
|
|
// Inspect member functions
|
|
for (const Function &func : scope->functionList) {
|
|
const bool constructor = func.isConstructor();
|
|
const bool destructor = func.isDestructor();
|
|
if (!func.hasBody()) {
|
|
if (destructor && !func.isDefault()) { // implementation for destructor is not seen and not defaulted => assume it deallocates all variables properly
|
|
deallocInDestructor = true;
|
|
memberDealloc = CheckMemoryLeak::Many;
|
|
}
|
|
continue;
|
|
}
|
|
bool body = false;
|
|
const Token *end = func.functionScope->bodyEnd;
|
|
for (const Token *tok = func.arg->link(); tok != end; tok = tok->next()) {
|
|
if (tok == func.functionScope->bodyStart)
|
|
body = true;
|
|
else {
|
|
if (!body) {
|
|
if (!Token::Match(tok, ":|, %varid% (", varid))
|
|
continue;
|
|
}
|
|
|
|
// Allocate..
|
|
if (!body || Token::Match(tok, "%varid% =|[", varid)) {
|
|
// var1 = var2 = ...
|
|
// bail out
|
|
if (tok->strAt(-1) == "=")
|
|
return;
|
|
|
|
// Foo::var1 = ..
|
|
// bail out when not same class
|
|
if (tok->strAt(-1) == "::" &&
|
|
tok->strAt(-2) != scope->className)
|
|
return;
|
|
|
|
const Token* allocTok = tok->tokAt(body ? 2 : 3);
|
|
if (tok->astParent() && tok->astParent()->str() == "[" && tok->astParent()->astParent())
|
|
allocTok = tok->astParent()->astParent()->astOperand2();
|
|
|
|
AllocType alloc = getAllocationType(allocTok, 0);
|
|
if (alloc != CheckMemoryLeak::No) {
|
|
if (constructor)
|
|
allocInConstructor = true;
|
|
|
|
if (memberAlloc != No && memberAlloc != alloc)
|
|
alloc = CheckMemoryLeak::Many;
|
|
|
|
if (alloc != CheckMemoryLeak::Many && memberDealloc != CheckMemoryLeak::No && memberDealloc != CheckMemoryLeak::Many && memberDealloc != alloc) {
|
|
mismatchAllocDealloc({tok}, classname + "::" + varname);
|
|
}
|
|
|
|
memberAlloc = alloc;
|
|
}
|
|
}
|
|
|
|
if (!body)
|
|
continue;
|
|
|
|
// Deallocate..
|
|
AllocType dealloc = getDeallocationType(tok, varid);
|
|
// some usage in the destructor => assume it's related
|
|
// to deallocation
|
|
if (destructor && tok->str() == varname)
|
|
dealloc = CheckMemoryLeak::Many;
|
|
if (dealloc != CheckMemoryLeak::No) {
|
|
if (destructor)
|
|
deallocInDestructor = true;
|
|
|
|
if (dealloc != CheckMemoryLeak::Many && memberAlloc != CheckMemoryLeak::No && memberAlloc != Many && memberAlloc != dealloc) {
|
|
mismatchAllocDealloc({tok}, classname + "::" + varname);
|
|
}
|
|
|
|
// several types of allocation/deallocation?
|
|
if (memberDealloc != CheckMemoryLeak::No && memberDealloc != dealloc)
|
|
dealloc = CheckMemoryLeak::Many;
|
|
|
|
memberDealloc = dealloc;
|
|
}
|
|
|
|
// Function call .. possible deallocation
|
|
else if (Token::Match(tok->previous(), "[{};] %name% (")) {
|
|
if (!CheckMemoryLeakInFunction::test_white_list(tok->str(), mSettings, mTokenizer->isCPP())) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (allocInConstructor && !deallocInDestructor) {
|
|
unsafeClassError(tokVarname, classname, classname + "::" + varname /*, memberAlloc*/);
|
|
} else if (memberAlloc != CheckMemoryLeak::No && memberDealloc == CheckMemoryLeak::No) {
|
|
unsafeClassError(tokVarname, classname, classname + "::" + varname /*, memberAlloc*/);
|
|
}
|
|
}
|
|
|
|
void CheckMemoryLeakInClass::unsafeClassError(const Token *tok, const std::string &classname, const std::string &varname)
|
|
{
|
|
if (!mSettings->severity.isEnabled(Severity::style))
|
|
return;
|
|
|
|
reportError(tok, Severity::style, "unsafeClassCanLeak",
|
|
"$symbol:" + classname + "\n"
|
|
"$symbol:" + varname + "\n"
|
|
"Class '" + classname + "' is unsafe, '" + varname + "' can leak by wrong usage.\n"
|
|
"The class '" + classname + "' is unsafe, wrong usage can cause memory/resource leaks for '" + varname + "'. This can for instance be fixed by adding proper cleanup in the destructor.", CWE398, Certainty::normal);
|
|
}
|
|
|
|
|
|
void CheckMemoryLeakInClass::checkPublicFunctions(const Scope *scope, const Token *classtok)
|
|
{
|
|
// Check that public functions deallocate the pointers that they allocate.
|
|
// There is no checking how these functions are used and therefore it
|
|
// isn't established if there is real leaks or not.
|
|
if (!mSettings->severity.isEnabled(Severity::warning))
|
|
return;
|
|
|
|
const int varid = classtok->varId();
|
|
|
|
// Parse public functions..
|
|
// If they allocate member variables, they should also deallocate
|
|
for (const Function &func : scope->functionList) {
|
|
if ((func.type == Function::eFunction || func.type == Function::eOperatorEqual) &&
|
|
func.access == AccessControl::Public && func.hasBody()) {
|
|
const Token *tok2 = func.functionScope->bodyStart->next();
|
|
if (Token::Match(tok2, "%varid% =", varid)) {
|
|
const CheckMemoryLeak::AllocType alloc = getAllocationType(tok2->tokAt(2), varid);
|
|
if (alloc != CheckMemoryLeak::No)
|
|
publicAllocationError(tok2, tok2->str());
|
|
} else if (Token::Match(tok2, "%type% :: %varid% =", varid) &&
|
|
tok2->str() == scope->className) {
|
|
const CheckMemoryLeak::AllocType alloc = getAllocationType(tok2->tokAt(4), varid);
|
|
if (alloc != CheckMemoryLeak::No)
|
|
publicAllocationError(tok2, tok2->strAt(2));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckMemoryLeakInClass::publicAllocationError(const Token *tok, const std::string &varname)
|
|
{
|
|
reportError(tok, Severity::warning, "publicAllocationError", "$symbol:" + varname + "\nPossible leak in public function. The pointer '$symbol' is not deallocated before it is allocated.", CWE398, Certainty::normal);
|
|
}
|
|
|
|
|
|
void CheckMemoryLeakStructMember::check()
|
|
{
|
|
if (mSettings->clang)
|
|
return;
|
|
|
|
const SymbolDatabase* symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
for (const Variable* var : symbolDatabase->variableList()) {
|
|
if (!var || (!var->isLocal() && !(var->isArgument() && var->scope())) || var->isStatic())
|
|
continue;
|
|
if (var->isReference() || (var->valueType() && var->valueType()->pointer > 1))
|
|
continue;
|
|
if (var->typeEndToken()->isStandardType())
|
|
continue;
|
|
if (var->scope()->hasInlineOrLambdaFunction())
|
|
continue;
|
|
checkStructVariable(var);
|
|
}
|
|
}
|
|
|
|
bool CheckMemoryLeakStructMember::isMalloc(const Variable *variable)
|
|
{
|
|
const int declarationId(variable->declarationId());
|
|
bool alloc = false;
|
|
for (const Token *tok2 = variable->nameToken(); tok2 && tok2 != variable->scope()->bodyEnd; tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "= %varid% [;=]", declarationId)) {
|
|
return false;
|
|
} else if (Token::Match(tok2, "%varid% = malloc|kmalloc (", declarationId)) {
|
|
alloc = true;
|
|
}
|
|
}
|
|
return alloc;
|
|
}
|
|
|
|
void CheckMemoryLeakStructMember::checkStructVariable(const Variable * const variable)
|
|
{
|
|
// Is struct variable a pointer?
|
|
if (variable->isArrayOrPointer()) {
|
|
// Check that variable is allocated with malloc
|
|
if (!isMalloc(variable))
|
|
return;
|
|
} else if (!mTokenizer->isC() && (!variable->typeScope() || variable->typeScope()->getDestructor())) {
|
|
// For non-C code a destructor might cleanup members
|
|
return;
|
|
}
|
|
|
|
// Check struct..
|
|
int indentlevel2 = 0;
|
|
|
|
auto deallocInFunction = [this](const Token* tok, int structid) -> bool {
|
|
// Calling non-function / function that doesn't deallocate?
|
|
if (CheckMemoryLeakInFunction::test_white_list(tok->str(), mSettings, mTokenizer->isCPP()))
|
|
return false;
|
|
|
|
// Check if the struct is used..
|
|
bool deallocated = false;
|
|
const Token* const end = tok->linkAt(1);
|
|
for (const Token* tok2 = tok; tok2 != end; tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "[(,] &| %varid% [,)]", structid)) {
|
|
/** @todo check if the function deallocates the memory */
|
|
deallocated = true;
|
|
break;
|
|
}
|
|
|
|
if (Token::Match(tok2, "[(,] &| %varid% . %name% [,)]", structid)) {
|
|
/** @todo check if the function deallocates the memory */
|
|
deallocated = true;
|
|
break;
|
|
}
|
|
};
|
|
|
|
return deallocated;
|
|
};
|
|
|
|
// return { memberTok, rhsTok }
|
|
auto isMemberAssignment = [](const Token* varTok, int varId) -> std::pair<const Token*, const Token*> {
|
|
if (varTok->varId() != varId)
|
|
return {};
|
|
const Token* top = varTok;
|
|
while (top->astParent()) {
|
|
if (Token::Match(top->astParent(), "(|["))
|
|
return {};
|
|
top = top->astParent();
|
|
}
|
|
if (!Token::simpleMatch(top, "=") || !precedes(varTok, top))
|
|
return {};
|
|
const Token* dot = top->astOperand1();
|
|
while (dot && dot->str() != ".")
|
|
dot = dot->astOperand1();
|
|
if (!dot)
|
|
return {};
|
|
return { dot->astOperand2(), top->next() };
|
|
};
|
|
std::pair<const Token*, const Token*> assignToks;
|
|
|
|
const Token* tokStart = variable->nameToken();
|
|
if (variable->isArgument() && variable->scope())
|
|
tokStart = variable->scope()->bodyStart->next();
|
|
for (const Token *tok2 = tokStart; tok2 && tok2 != variable->scope()->bodyEnd; 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% [,)]", variable->declarationId()))
|
|
break;
|
|
|
|
// Struct member is allocated => check if it is also properly deallocated..
|
|
else if ((assignToks = isMemberAssignment(tok2, variable->declarationId())).first && assignToks.first->varId()) {
|
|
if (getAllocationType(assignToks.second, assignToks.first->varId()) == AllocType::No)
|
|
continue;
|
|
|
|
if (variable->isArgument() && variable->valueType() && variable->valueType()->type == ValueType::UNKNOWN_TYPE && assignToks.first->astParent()) {
|
|
const Token* accessTok = assignToks.first->astParent();
|
|
while (Token::simpleMatch(accessTok->astOperand1(), "."))
|
|
accessTok = accessTok->astOperand1();
|
|
if (Token::simpleMatch(accessTok, ".") && accessTok->originalName() == "->")
|
|
continue;
|
|
}
|
|
|
|
const int structid(variable->declarationId());
|
|
const int structmemberid(assignToks.first->varId());
|
|
|
|
// This struct member is allocated.. check that it is deallocated
|
|
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, variable->name() + "." + tok2->strAt(2), Malloc);
|
|
break;
|
|
}
|
|
--indentlevel3;
|
|
}
|
|
|
|
// Deallocating the struct member..
|
|
else if (getDeallocationType(tok3, structmemberid) != AllocType::No) {
|
|
// 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) {
|
|
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 (Token::Match(tok3, "free|kfree ( %varid% )", structid)) {
|
|
if (indentlevel2 == 0)
|
|
memoryLeak(tok3, variable->name() + "." + tok2->strAt(2), Malloc);
|
|
break;
|
|
}
|
|
|
|
// failed allocation => skip code..
|
|
else if (Token::simpleMatch(tok3, "if (") &&
|
|
notvar(tok3->next()->astOperand2(), 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 (ifvar(tok3, structmemberid, "!=", "0")) {
|
|
// goto the ")"
|
|
tok3 = tok3->next()->link();
|
|
|
|
// check if the variable is deallocated or returned..
|
|
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) &&
|
|
!Token::Match(tok3, "return & %varid%", structid) &&
|
|
!(Token::Match(tok3, "return %varid% . %var%", structid) && tok3->tokAt(3)->varId() == structmemberid) &&
|
|
!(Token::Match(tok3, "return %name% (") && tok3->astOperand1() && deallocInFunction(tok3->astOperand1(), structid))) {
|
|
memoryLeak(tok3, variable->name() + "." + tok2->strAt(2), Malloc);
|
|
}
|
|
break;
|
|
}
|
|
|
|
// struct assignment..
|
|
else if (Token::Match(tok3, "= %varid% ;", structid)) {
|
|
break;
|
|
} else if (Token::Match(tok3, "= %var% . %varid% ;", structmemberid)) {
|
|
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, "%name% (")) {
|
|
if (deallocInFunction(tok3, structid))
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
void CheckMemoryLeakNoVar::check()
|
|
{
|
|
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
|
|
|
|
// only check functions
|
|
for (const Scope * scope : symbolDatabase->functionScopes) {
|
|
|
|
// Checks if a call to an allocation function like malloc() is made and its return value is not assigned.
|
|
checkForUnusedReturnValue(scope);
|
|
|
|
// Checks to see if a function is called with memory allocated for an argument that
|
|
// could be leaked if a function called for another argument throws.
|
|
checkForUnsafeArgAlloc(scope);
|
|
|
|
// Check for leaks where a the return value of an allocation function like malloc() is an input argument,
|
|
// for example f(malloc(1)), where f is known to not release the input argument.
|
|
checkForUnreleasedInputArgument(scope);
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Checks if an input argument to a function is the return value of an allocation function
|
|
// like malloc(), and the function does not release it.
|
|
//---------------------------------------------------------------------------
|
|
void CheckMemoryLeakNoVar::checkForUnreleasedInputArgument(const Scope *scope)
|
|
{
|
|
// parse the executable scope until tok is reached...
|
|
for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
|
|
// allocating memory in parameter for function call..
|
|
if (tok->varId() || !Token::Match(tok, "%name% ("))
|
|
continue;
|
|
|
|
// check if the output of the function is assigned
|
|
const Token* tok2 = tok->next()->astParent();
|
|
while (tok2 && (tok2->isCast() || Token::Match(tok2, "?|:")))
|
|
tok2 = tok2->astParent();
|
|
if (Token::Match(tok2, "%assign%")) // TODO: check if function returns allocated resource
|
|
continue;
|
|
if (Token::simpleMatch(tok->astTop(), "return"))
|
|
continue;
|
|
|
|
const std::string& functionName = tok->str();
|
|
if ((mTokenizer->isCPP() && functionName == "delete") ||
|
|
functionName == "free" ||
|
|
functionName == "fclose" ||
|
|
functionName == "realloc" ||
|
|
functionName == "return")
|
|
continue;
|
|
|
|
if (Token::simpleMatch(tok->next()->astParent(), "(")) // passed to another function
|
|
continue;
|
|
if (!tok->isKeyword() && mSettings->library.isNotLibraryFunction(tok))
|
|
continue;
|
|
if (!CheckMemoryLeakInFunction::test_white_list(functionName, mSettings, mTokenizer->isCPP()))
|
|
continue;
|
|
|
|
const std::vector<const Token *> args = getArguments(tok);
|
|
for (const Token* arg : args) {
|
|
if (arg->isOp() && !(tok->isKeyword() && arg->str() == "*")) // e.g. switch (*new int)
|
|
continue;
|
|
while (arg->astOperand1()) {
|
|
if (mTokenizer->isCPP() && Token::simpleMatch(arg, "new"))
|
|
break;
|
|
arg = arg->astOperand1();
|
|
}
|
|
const AllocType alloc = getAllocationType(arg, 0);
|
|
if (alloc == No)
|
|
continue;
|
|
if ((alloc == New || alloc == NewArray) && arg->next() && !(arg->next()->isStandardType() || mSettings->library.detectContainerOrIterator(arg)))
|
|
continue;
|
|
if (isReopenStandardStream(arg))
|
|
continue;
|
|
functionCallLeak(arg, arg->str(), functionName);
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Checks if a call to an allocation function like malloc() is made and its return value is not assigned.
|
|
//---------------------------------------------------------------------------
|
|
void CheckMemoryLeakNoVar::checkForUnusedReturnValue(const Scope *scope)
|
|
{
|
|
for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
|
|
const bool isNew = mTokenizer->isCPP() && tok->str() == "new";
|
|
if (!isNew && !Token::Match(tok, "%name% ("))
|
|
continue;
|
|
|
|
if (tok->varId())
|
|
continue;
|
|
|
|
const AllocType allocType = getAllocationType(tok, 0);
|
|
if (allocType == No)
|
|
continue;
|
|
|
|
if (tok != tok->next()->astOperand1() && !isNew)
|
|
continue;
|
|
|
|
if (isReopenStandardStream(tok))
|
|
continue;
|
|
if (isOpenDevNull(tok))
|
|
continue;
|
|
|
|
// get ast parent, skip casts
|
|
const Token *parent = isNew ? tok->astParent() : tok->next()->astParent();
|
|
while (parent && parent->isCast())
|
|
parent = parent->astParent();
|
|
|
|
bool warn = true;
|
|
if (isNew) {
|
|
const Token* typeTok = tok->next();
|
|
warn = typeTok && (typeTok->isStandardType() || mSettings->library.detectContainer(typeTok));
|
|
}
|
|
|
|
if (!parent && warn) {
|
|
// Check if we are in a C++11 constructor
|
|
const Token * closingBrace = Token::findmatch(tok, "}|;");
|
|
if (closingBrace->str() == "}" && Token::Match(closingBrace->link()->tokAt(-1), "%name%") && (!isNew && precedes(tok, closingBrace->link())))
|
|
continue;
|
|
returnValueNotUsedError(tok, tok->str());
|
|
} else if (Token::Match(parent, "%comp%|!|,|%oror%|&&|:")) {
|
|
if (parent->astParent() && parent->str() == ",")
|
|
continue;
|
|
if (parent->str() == ":") {
|
|
if (!(Token::simpleMatch(parent->astParent(), "?") && !parent->astParent()->astParent()))
|
|
continue;
|
|
}
|
|
returnValueNotUsedError(tok, tok->str());
|
|
}
|
|
}
|
|
}
|
|
|
|
//---------------------------------------------------------------------------
|
|
// Check if an exception could cause a leak in an argument constructed with
|
|
// shared_ptr/unique_ptr. For example, in the following code, it is possible
|
|
// that if g() throws an exception, the memory allocated by "new int(42)"
|
|
// could be leaked. See stackoverflow.com/questions/19034538/
|
|
// why-is-there-memory-leak-while-using-shared-ptr-as-a-function-parameter
|
|
//
|
|
// void x() {
|
|
// f(shared_ptr<int>(new int(42)), g());
|
|
// }
|
|
//---------------------------------------------------------------------------
|
|
void CheckMemoryLeakNoVar::checkForUnsafeArgAlloc(const Scope *scope)
|
|
{
|
|
// This test only applies to C++ source
|
|
if (!mTokenizer->isCPP() || !mSettings->certainty.isEnabled(Certainty::inconclusive) || !mSettings->severity.isEnabled(Severity::warning))
|
|
return;
|
|
|
|
for (const Token *tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
|
|
if (Token::Match(tok, "%name% (")) {
|
|
const Token *endParamToken = tok->next()->link();
|
|
const Token* pointerType = nullptr;
|
|
const Token* functionCalled = nullptr;
|
|
|
|
// Scan through the arguments to the function call
|
|
for (const Token *tok2 = tok->tokAt(2); tok2 && tok2 != endParamToken; tok2 = tok2->nextArgument()) {
|
|
const Function *func = tok2->function();
|
|
const bool isNothrow = func && (func->isAttributeNothrow() || func->isThrow());
|
|
|
|
if (Token::Match(tok2, "shared_ptr|unique_ptr <") && Token::Match(tok2->next()->link(), "> ( new %name%")) {
|
|
pointerType = tok2;
|
|
} else if (!isNothrow) {
|
|
if (Token::Match(tok2, "%name% ("))
|
|
functionCalled = tok2;
|
|
else if (tok2->isName() && Token::simpleMatch(tok2->next()->link(), "> ("))
|
|
functionCalled = tok2;
|
|
}
|
|
}
|
|
|
|
if (pointerType && functionCalled) {
|
|
std::string functionName = functionCalled->str();
|
|
if (functionCalled->strAt(1) == "<") {
|
|
functionName += '<';
|
|
for (const Token* tok2 = functionCalled->tokAt(2); tok2 != functionCalled->next()->link(); tok2 = tok2->next())
|
|
functionName += tok2->str();
|
|
functionName += '>';
|
|
}
|
|
std::string objectTypeName;
|
|
for (const Token* tok2 = pointerType->tokAt(2); tok2 != pointerType->next()->link(); tok2 = tok2->next())
|
|
objectTypeName += tok2->str();
|
|
|
|
unsafeArgAllocError(tok, functionName, pointerType->str(), objectTypeName);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void CheckMemoryLeakNoVar::functionCallLeak(const Token *loc, const std::string &alloc, const std::string &functionCall)
|
|
{
|
|
reportError(loc, Severity::error, "leakNoVarFunctionCall", "Allocation with " + alloc + ", " + functionCall + " doesn't release it.", CWE772, Certainty::normal);
|
|
}
|
|
|
|
void CheckMemoryLeakNoVar::returnValueNotUsedError(const Token *tok, const std::string &alloc)
|
|
{
|
|
reportError(tok, Severity::error, "leakReturnValNotUsed", "$symbol:" + alloc + "\nReturn value of allocation function '$symbol' is not stored.", CWE771, Certainty::normal);
|
|
}
|
|
|
|
void CheckMemoryLeakNoVar::unsafeArgAllocError(const Token *tok, const std::string &funcName, const std::string &ptrType, const std::string& objType)
|
|
{
|
|
const std::string factoryFunc = ptrType == "shared_ptr" ? "make_shared" : "make_unique";
|
|
reportError(tok, Severity::warning, "leakUnsafeArgAlloc",
|
|
"$symbol:" + funcName + "\n"
|
|
"Unsafe allocation. If $symbol() throws, memory could be leaked. Use " + factoryFunc + "<" + objType + ">() instead.",
|
|
CWE401,
|
|
Certainty::inconclusive); // Inconclusive because funcName may never throw
|
|
}
|