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Cppcheck - A tool for static C/C++ code analysis
Overview
Cppcheck is an analysis tool for C/C++ code. Unlike C/C++ compilers and many other analysis tools, we don't detect syntax errors. Cppcheck only detects the types of bugs that the compilers normally fail to detect. The goal is no false positives.
We recommend that you enable as many warnings as possible in your compiler.
If you use Visual C++: you should use warning level 4.
If you use GCC: take a look at Warning options - using GCC
If you use another compiler: look in the manual.
Supported platforms:
- You can check non-standard code that includes various compiler extensions, inline assembly code, etc.
- Cppcheck is supposed to be compilable by any C++ compiler which handles the latest C++ standard.
- Cppcheck is supposed to work on any platform that has sufficient cpu and memory.
Accuracy
Cppcheck is far from finished, it is continuosly improved to make it more accurate.
Cppcheck is rarely wrong about reported errors. But there are many bugs that it doesn't detect.
You will find more bugs in your software by testing your software carefully, than by using Cppcheck.
You will find more bugs in your software by instrumenting your software (with for example valgrind), than by using Cppcheck.
It is unlikely that you will find all the bugs in your software through testing and instrumenting. Cppcheck can detect some of the bugs that you have missed.
Plugins
There are plugins for:
- Code::Blocks
- Codelite - Integrated
- Eclipse - http://cppcheclipse.googlecode.com/
- Hudson - http://wiki.hudson-ci.org/display/HUDSON/Cppcheck+Plugin
No plugin exists for Visual Studio - but you can add cppcheck as an external tool.
Checks
Auto Variables
A pointer to a variable is only valid as long as the variable is in scope. Check:
- returning a pointer to variable
- assigning address of an variable to an effective parameter of a function
Bounds checking
out of bounds checking
Class
Check the code for each class.
- Missing constructors
- Are all variables initialized by the constructors?
- Warn if memset, memcpy etc are used on a class
- If it's a base class, check that the destructor is virtual
- The operator= should return a constant reference to itself
- Are there unused private functions
Deprecated functions
Warn if any of these deprecated functions are used:
- mktemp
- gets
- scanf
Exception Safety
Checking exception safety
- Throwing exceptions in destructors
- Unsafe use of 'new'
- Unsafe reallocation
- Throwing exception during invalid state
Memory leaks (function variables)
Is there any allocated memory when a function goes out of scope
Memory leaks (class variables)
If the constructor allocate memory then the destructor must deallocate it.
Memory leaks (struct members)
Don't forget to deallocate struct members
Other
Other checks
- bad usage of the function 'sprintf' (overlapping data)
- division with zero
- null pointer dereferencing
- using uninitialized variables and data
- C-style pointer cast in cpp file
- redundant if
- bad usage of the function 'strtol'
- unsigned division
- unused struct member
- passing parameter by value
- Incomplete statement
- check how signed char variables are used
- variable scope can be limited
- condition that is always true/false
- unusal pointer arithmetic. For example: "abc" + 'd'
- optimisation: detect post increment/decrement
STL usage
Check for invalid usage of STL:
- out of bounds errors
- misuse of iterators when iterating through a container
- mismatching containers in calls
- dereferencing an erased iterator
- for vectors: using iterator/pointer after push_back has been used
- dangerous usage of find
- optimisation: using empty() instead of size()
Unused functions
Check for functions that are never called
Forum, chat
IRC channel:
channel: #cppcheck
server: irc.freenode.net
Forum: http://apps.sourceforge.net/phpbb/cppcheck///
Future releases
The plan is to release a new version every 1-2 months.
Version 1.41 is planned to be released on March 7th.
Bugs and feature requests
Use Trac to report any problems: http://apps.sourceforge.net/trac/cppcheck/
Defects are for severe bugs such as:
- False positives (when "--all" is not used)
- Cppcheck hangs/crashes
- Bug in any of the core classes (Tokenizer/Token/Preprocessor)
- Fail to compile
Enhancements are for issues such as:
- Fail to detect bug
- Change the output of Cppcheck
- Suggestion for a new check
Contribute
You are welcome to contribute. Help is needed.
- Testing - Pick a project and test it's source with latest version. Write tickets to Trac about issues you find from Cppcheck. If you test open source projects and write bug reports to them, check the issues in Found bugs section, and write links to the bug reports you have created e.g. to our forum, so we can keep a track about them.
- Developing - Pick a ticket from Trac, write a test case for it (and write a comment to the ticket that test case has been created). Or pick a test case that fails and try to fix it. Make a patch and submit it to Trac either inline if it is small, or attach it as a file.
- Marketing - Write articles, reviews or tell your friends about us. The more users we have, the more people we have testing and the better we can become.
- Design - Invent new good checks and create tickets to Trac about them.
- Integration - Write a plugin to your favorite IDE or create a package for your distribution or operating system.
- Technical Writer - Write better documentation for the bugs we find. Currently only a few bugs have any documentation at all.
Getting the source code
Latest version can be found in the git
git clone git://github.com/danmar/cppcheck.git
You can also download the latest sources in a zip or tgz archive:
1. goto this webpage: http://github.com/danmar/cppcheck/ 2. click the "download" button. And choose the file format you want.
Found bugs
Cppcheck is continuously tested against various open source projects.
It's a good way to find the false positives that Cppcheck gives.
