Direkt zum Hauptbereich

Static analysis tool: cppcheck

This post shall be the start of a loose series on static code analysis tools that I've been using when professionally coding.
The tools should be compared against the same code base, so that one could get an impression what the benefits and flaws of a certain tool are.

Please put your questions/suggestions into the comments.

Today's tool should be cppcheck.

Supported Languages

  • C
  • C++
Dependencies (besides gcc)
  • libprce
Special features
  • custom rules for checking can be applied as prce-compatible regular expressions

Testing

  • Under test shall be the unmodified code of busybox version 1.29.2 as to be found as yocto-poky layer at gitrev 3541f019a505d18263fad0b46b88d470e3fd9d62.
  • As configuration for yocto the standard configuration is used.
  • cppcheck is used in version 1.87

Number of total findings in code: 308
Number of different finding types: 26

Findings in details class vs. count

nullPointer 3
memleakOnRealloc 2
nullPointerArithmeticRedundantCheck 2
shiftNegative 1
uninitvar 69
redundantAssignInSwitch 2
va_end_missing 2
invalidPrintfArgType_sint 35
invalidScanfArgType_int 22
signConversion 2
identicalConditionAfterEarlyExit 1
bufferAccessOutOfBounds 1
integerOverflow 2
uselessAssignmentPtrArg 1
invalidscanf 6
wrongPrintfScanfArgNum 1
shiftTooManyBitsSigned 13
leakNoVarFunctionCall 1
selfAssignment 71
constStatement 1
invalidPrintfArgType_uint 43
nullPointerRedundantCheck 3
resourceLeak 1
ignoredReturnValue 2
shiftTooManyBits 3
allocaCalled 18

Conclusion

Overall nive performance and quality of findings. Finds many common mistakes done when writing C-code.

Pros
  • Easy to build
  • Good quality of findings
  • Find the important stuff like shiftTooManyBits or integerOverflow
  • Extendible by custom rules
  • Relatively fast while executing 
Cons
  • Not many
  • Custom rules are hard to write (prce-regex in single-line mode (sic))
BTW if you want to use cppcheck out of the box in your YOCTO build see here
Labels:

Kommentare

Kommentar veröffentlichen

Beliebte Posts aus diesem Blog

Speedup python on embedded systems

Have you ever considered to use python as a scripting language in an embedded system? I've been using this on recent projects although it wasn't my first choice. If I had to choose a scripting language to be used in embedded I always had a strong preference for shell/bash or lua, because they are either builtin or designed to have a significant lower footprint compared to others. Nevertheless the choice was python3 (was out of my hands to decide). When putting together the first builds using YOCTO I realized that there are two sides to python. the starting phase, where the app is initializing the execution phase, where the app just processes new data In the 2nd phase python3 has good tradeoffs between maintainability of code vs. execution speed, so there is nothing to moan about. Startup is the worst But the 1st phase where the python3-interpreter is starting is really bad. So I did some research where is might be coming from. Just to give a comparison of
Kommentar veröffentlichen
Mehr anzeigen

Making go not a no-go

Anyone that dealt with container engines came across go - a wonderful language, that was built to provide a right way of what C++ intended to do. The language itself is pretty straight forward and upstream poky support is given since ages... In the go world one would just run 1 2 go get github.com/foo/bar go build github.com/foo/bar and magically the go ecosystem would pull all the needed sources and build them into an executable. This is where the issues start... In the Openembedded world, one would have  one provider (aka recipe) for each dependency each recipe comes with a (remote) artifact (e.g. tarball, git repo, a.s.o.) which can be archived (so one can build the same software at a later point in time without any online connectivity) dedicated license information all this information is pretty useful when working is an environment (aka company) that has restrictions, such as reproducible builds license compliance security compliance (for instance no unpatched CVE) but when us
Kommentar veröffentlichen
Mehr anzeigen

Using bbclass based on conditions

When you are working with YOCTO build system, you might be aware of the construct .bbclass. For those who are not: these are code snippets which will be injected into the recipe itself. Mostly they add new tasks or provide some generalization for things you often. A good example might be pypi.bbclass. In your recipe you write usually something likes this SRC_URI = "https://www.foo.org/foo.tar.gz" When it comes to python packages a way more elegant way is to use pypi.org . And here does the pypi.bbclass provide some magic - you recipe will just look like this inherit pypi   PYPI_PACKAGE = "foo" the bbclass pypi will automatically translate the variable name PYPI_PACKAGE into a valid URL to fetch the package. Also it will set some internal variables such as HOMEPAGE or S to the correct settings. You see life can be convenient when you know how to do it. If you want to apply a bbclass you can either insert inherit foo.bbclass into each recipe or you
Kommentar veröffentlichen
Mehr anzeigen