PVS-Studio, a solution for developers of modern resource-intensive applications

1. PVS-Studio, a solution for developers of modern resource-intensive applications OOO “Program Verification Systems” (Co Ltd) www.viva64.com

2. PVS-Studio Overview PVS-Studio is a static analyzer that detects errors in source code of C, C++, C++11, C++/CX applications. There are sets of rules included into PVS-Studio: • General-purpose diagnosis • Detection of possible optimizations • Diagnosis of 64-bit errors (Viva64) • Diagnosis of parallel errors (VivaMP)

3. Examples of errors we detect

4. Priority of & and! operations ReturntoCastleWolfenstein – computer game, first person shooter, developed by idSoftware company. Game engine is available under GPL license. #define SVF_CASTAI 0x00000010 if ( !ent->r.svFlags& SVF_CASTAI ) if ( ! (ent->r.svFlags & SVF_CASTAI) )

5. Usage of && instead of & Stickies– yellow sticky notes, just only on your monitor. #define REO_INPLACEACTIVE (0x02000000L) #define REO_OPEN (0x04000000L) if (reObj.dwFlags&& REO_INPLACEACTIVE) m_pRichEditOle->InPlaceDeactivate(); if(reObj.dwFlags&& REO_OPEN) hr = reObj.poleobj->Close(OLECLOSE_NOSAVE);

6. Undefined behavior Miranda IM (Miranda Instant Messenger) – instant messaging software for Microsoft Windows. while (*(n = ++s + strspn(s, EZXML_WS)) && *n != '>') {

7. Usage of `delete` for an array Chromium – open source web browser developed by Google. The development of GoogleChrome browser is based upon Chromium. auto_ptr<VARIANT> child_array(new VARIANT[child_count]); You should not useauto_ptr with arrays. Only one element is destroyed inside auto_ptr destructor: ~auto_ptr() { delete _Myptr; } For example you can use boost::scoped_array as an alternative.

8. Condition is always true WinDjView is fast and small app for viewing files of DjVu format. inline boolIsValidChar(int c) { return c == 0x9 || 0xA || c == 0xD || c >= 0x20 && c <= 0xD7FF || c >= 0xE000 && c <= 0xFFFD || c >= 0x10000 && c <= 0x10FFFF; }

9. Code formatting differs from it’s own logic Squirrel – interpreted programming language, which is developed to be used as a scripting language in real time applications such as computer games. if(pushval != 0) if(pushval) v->GetUp(-1) = t; else v->Pop(1); v->Pop(1); - will never be reached

10. Incidental local variable declaration FCE Ultra – open source Nintendo Entertainment System console emulator intiNesSaveAs(char* name) { ... fp = fopen(name,"wb"); int x = 0; if (!fp) int x = 1; ... }

11. Using char asunsigned char // check each line for illegal utf8 sequences. // If one is found, we treatthe file as ASCII, // otherwise we assumean UTF8 file. char * utf8CheckBuf = lineptr; while ((bUTF8)&&(*utf8CheckBuf)) { if ((*utf8CheckBuf == 0xC0)|| (*utf8CheckBuf == 0xC1)|| (*utf8CheckBuf >= 0xF5)) { bUTF8 = false; break; } TortoiseSVN — client of Subversion revision control system, implemented as Windows shell extension.

12. Incidental use of octal values oCell._luminance = uint16(0.2220f*iPixel._red + 0.7067f*iPixel._blue + 0.0713f*iPixel._green); .... oCell._luminance = 2220*iPixel._red + 7067*iPixel._blue + 0713*iPixel._green; eLynx Image Processing SDK and Lab

13. One variable is used for two loops Lugaru— first commercial game developed by WolfireGamesindependent team. static inti,j,k,l,m; ... for(j=0; j<numrepeats; j++){ ... for(i=0; i<num_joints; i++){ ... for(j=0;j<num_joints;j++){ if(joints[j].locked)freely=0; } ... } ... }

14. Array overrun LAME – free app for MP3 audio encoding. #define SBMAX_l22 int l[1+SBMAX_l]; for (r0 = 0; r0 < 16; r0++) { ... for (r1 = 0; r1 < 8; r1++) { int a2 = gfc->scalefac_band.l[r0 + r1 + 2];

15. Priority of * and ++ operations eMuleis a client for ED2K file sharing network. STDMETHODIMP CCustomAutoComplete::Next(..., ULONG *pceltFetched) { ... if (pceltFetched != NULL) *pceltFetched++; ... } (*pceltFetched)++;

16. Comparison mistake WinMerge — free open source software intended for the comparison and synchronization of files and directories. BUFFERTYPE m_nBufferType[2]; ... // Handle unnamed buffers if ((m_nBufferType[nBuffer] == BUFFER_UNNAMED) || (m_nBufferType[nBuffer] == BUFFER_UNNAMED)) nSaveErrorCode = SAVE_NO_FILENAME; By reviewing the code close by, this should contain: (m_nBufferType[0] == BUFFER_UNNAMED) || (m_nBufferType[1] == BUFFER_UNNAMED)

17. Forgotten array index void lNormalizeVector_32f_P3IM(..., Ipp32s* mask, ...) { Ipp32s i; Ipp32f norm; for(i=0; i<len; i++) { if(mask<0) continue; ... } } if(mask[i]<0) continue; IPP Samplesaresamples demonstrating how to work with Intel Performance Primitives Library 7.0.

18. Identical source code branches Notepad++ - free text editor for Windows supporting syntax highlight for a variety of programming languages. if (!_isVertical) Flags |= DT_BOTTOM; else Flags |= DT_BOTTOM; if (!_isVertical) Flags |=DT_VCENTER; else Flags |= DT_BOTTOM;

19. Calling incorrect function with similar name What a beautiful comment. But it is sad that here we’re doing not what was intended. /** Deletes all previous field specifiers. * This should be used when dealing * with clients that send multiple NEP_PACKET_SPEC * messages, so only the lastPacketSpec is taken * into account. */ intNEPContext::resetClientFieldSpecs(){ this->fspecs.empty(); return OP_SUCCESS; } /* End of resetClientFieldSpecs() */ Nmap Security Scanner – free utility intended for diverse customizable scanning of IP-networks with any number of objects and for identification of the statuses of the objects belonging to the network which is being scanned.

20. Dangerous ?: operator NewtonGameDynamics– a well known physics engine which allows for reliable and fast simulation of environmental object’s physical behavior. den = dgFloat32 (1.0e-24f) * (den > dgFloat32(0.0f)) ? dgFloat32(1.0f) : dgFloat32(-1.0f); The priority of ?: is lower than that of multiplication operator *.

21. And so on, and so on… if((t=(char *)realloc( next->name, strlen(name+1)))) FCE Ultra if((t=(char *)realloc( next->name, strlen(name)+1))) minX=max(0,minX+mcLeftStart-2); minY=max(0,minY+mcTopStart-2); maxX=min((int)width,maxX+mcRightEnd-1); maxY=min((int)height,maxX+mcBottomEnd-1); minX=max(0,minX+mcLeftStart-2); minY=max(0,minY+mcTopStart-2); maxX=min((int)width,maxX+mcRightEnd-1); maxY=min((int)height,maxY+mcBottomEnd-1);

22. Low level memory management operations ID_INLINE mat3_t::mat3_t( float src[3][3] ) { memcpy( mat, src, sizeof( src ) ); } Return to Castle Wolfenstein ID_INLINE mat3_t::mat3_t( float (&src)[3][3] ) { memcpy( mat, src, sizeof( src ) ); } itemInfo_t *itemInfo; memset( itemInfo, 0, sizeof( &itemInfo ) ); memset( itemInfo, 0, sizeof( *itemInfo ) );

23. Low level memory management operations CxImage – open image processing library. memset(tcmpt->stepsizes, 0, sizeof(tcmpt->numstepsizes * sizeof(uint_fast16_t))); memset(tcmpt->stepsizes, 0, tcmpt->numstepsizes * sizeof(uint_fast16_t));

24. Low level memory management operations A beautiful example of 64-bit error: dgInt32 faceOffsetHitogram[256]; dgSubMesh* mainSegmenst[256]; memset (faceOffsetHitogram, 0, sizeof (faceOffsetHitogram)); memset (mainSegmenst, 0, sizeof (faceOffsetHitogram)); This code was duplicated but was not entirely corrected. As a result the size of pointer will not be equal to the size of dgInt32 type on Win64 and we will flush only a fraction of mainSegmenst array.

25. Low level memory management operations #define CONT_MAP_MAX 50 int _iContMap[CONT_MAP_MAX]; ... memset(_iContMap, -1, CONT_MAP_MAX); memset(_iContMap, -1, CONT_MAP_MAX * sizeof(int));

26. Low level memory management operations OGRE — open source Object-OrientedGraphicsRenderingEngine written in C++. Real w, x, y, z; ... inline Quaternion(Real* valptr) { memcpy(&w, valptr, sizeof(Real)*4); } Yes, at present this is not a mistake. But it is a landmine!

27. And a whole lot of other errors in well known projects • WinMerge • Chromium, Return to Castle Wolfenstein, etc • Miranda IM • Intel IPP Samples • Fennec Media Project • Ultimate Toolbox • Loki • eMule Plus, Pixie, VirtualDub, WinMerge, XUIFramework • Chromium • Qt • Apache HTTP Server • TortoiseSVN Here are the links to the articles containing descriptions of the errors: http://www.viva64.com/en/pvs-studio/

28. Types of detectable errors • copy-paste errors; • Incorrect formatting strings (printf); • buffer overflow; • Incorrect utilization of STL,WinAPI; • ... • errors concerning the migration of 32-bit applications to 64-bit systems (Viva64); • errors concerning the incorrect usage of OpenMP;

29. Integration • Visual Studio 2005+; • Embarcadero RAD Studio 2009+; • MinGW.

30. PVS-Studio Features • Incremental Analysis – verification of newly compiled files; • Verification of files which were recently modified several days ago; • Verification of files by their filenames from within the text file list; • continuous integration systems support; • version control systems integration; • ability to operate fro m command line interface; • «False Alarms» marking; • saving and loading of analysis results; • utilizing all available cores and processors; • interactive filters; • Russian and English online documentation; • Pdf documentation;

31. Integration withVisual Studio

32. Integration with Embarcadero RAD Studio

33. Incremental Analysis – verification of newly compiled files • you just work with Visual Studio as usual; • compile by F7; • the verification of newly compiled files will start in background automatically; • At the end of verification the notification will appear, allowing you to inspect detected errors;

34. VCSand CIsupport(revision control, continuous integration) • launching from command line: • sending the results by mail: • commands for launching from CruiseControl.Net, Hudson, Microsoft TFS are readily available "C:\Program Files (x86)\PVS-Studio\x64\PVS-Studio.exe" --sln-file "C:\Users\evg\Documents\ OmniSample\OmniSample (vs2008).sln" --plog-file "C:\Users\evg\Documents\result.plog" --vcinstalldir"C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC" --platform "x64" --configuration "Release” cmd.exe /c type result-log.plog.only_new_messages.txt

35. Interactive filters • filtering messages without restarting the analysis • Filtering by errors’ code, by filenames (including masks), by messages’ text, by warning levels; • displaying/hiding false alarms.

36. Integrated help reference(description of the errors)

37. PVS-Studio Advantages • Easy-to-download! You may download the PVS-Studio distribution package without registering and filling in any forms. • Easy-to-try! The PVS-Studio program is implemented as a plug-in for Visual Studio and Embarcadero RAD Studio. • Easy-to-buy! Unlike other code analyzers, we have simple pricing and licensing policy. • Easy-to-support! It is the analyzer's developers who directly communicate with users, which enables you to quickly get answers to even complicated questions related to programming.

38. Pricing policy • a license for a team of no more than five developers is €5250; • prolongation for one year – 80% of base price; • the site license for teams with 10+ developers;

39. Information about company OOO “Program Verification Systems” (Co Ltd) 300027, Russia, Tula, Metallurgov70-1-88. www.viva64.com support@viva64.com Working time: 09:00 – 18:00 (GMT +3:00)