wiki:UndertakerRelease1.1

The VAMOS team is pleased to announce undertaker 1.1. The undertaker tool is a result of the VAMOS[1] research project. Please visit our project site at:

http://vamos.informatik.uni-erlangen.de/trac/undertaker

What is undertaker?


The undertaker is a tool for static code analysis for code with C preprocessor directives that can be used in various modes. The most prominent one checks every single preprocessor block within the file whether it can be selected or deselected, which in many cases is a great asset for code maintenance.

Some preprocessor blocks are only seemingly conditional. In many cases, it turns out that additional constraints from the project's configuration model causes such #ifdef blocks to be in fact unconditionally selected or unselected. We call such block "dead" and "undead" conditional blocks.

Undertaker provides tools to extract the configuration model from the Linux configuration tooling Kconfig and to perform this check on whole source trees.

New in 1.1 is the support for #define and #undef directives in CPP Code.

 ,----
 | #undef A
 | #ifdef A
 | // Block 1
 | #endif
 `----

Here we identify Block 1 as an dead code-block, because it will never be compiled into the resulting binary. This analysis can be done completly without any information about the configuration model.

We have already performed a check on the v2.6.38 tree and provide easy access to the results via an online interface[2]. There is also a cpio archive with the report files.

What undertaker is not?


It isn't an automatic patch generator. Because of peculiarities in the Kconfig semantics, (ignored) coding guidelines and simply engineering issues, the reports might contain false negatives. Note that our philosophy is that we prefer false negatives over false positives, i.e., we prefer to miss reports than reports that are no issue at all.

What else can i do with undertaker?


You can extract boolean formulas (with or without model) for a given line of sourcecode in a file or for a given symbol. There is also an integration for emacs for interactive browsing of block and symbol preconditions.

Additional uses are currently under development.

[1] http://www4.informatik.uni-erlangen.de/Research/VAMOS/ [2] http://www4.informatik.uni-erlangen.de/Research/VAMOS/linux-trees/

Last modified 9 years ago Last modified on 03/22/11 14:05:38
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