[webkit-dev] Static source code analysis

[Ferenc, Rudolf]

Dear all,

My colleague Péter Siket and me are also members of the Open Source Laboratory 
at the Department of Software Engineering, University of Szeged, Hungary. We are 
performing R&D in static source code analysis and started to examine the source 
code of WebKit. In our preliminary checks we found four bugs (one missing 
initialization and three unchecked malloc-s), which are easy to fix. We reported 
these bugs in Bugzilla:
https://bugs.webkit.org/show_bug.cgi?id=19286
https://bugs.webkit.org/show_bug.cgi?id=19287

Sincerely,
   Rudolf Ferenc
   Department of Software Engineering, University of Szeged, Hungary
   http://www.inf.u-szeged.hu/sed/
   http://www.inf.u-szeged.hu/opensource/


Akos Kiss wrote:
> -------- Eredeti üzenet --------
> Tárgy: [webkit-dev] interested in js speed-up
> Dátum: Tue, 04 Mar 2008 09:32:26 +0100
> Feladó: Akos Kiss <akiss at inf.u-szeged.hu>
> Címzett: webkit-dev at lists.webkit.org
> 
> Dear all,
> (sorry, I don't know whom to contact directly)
> 
> we have a small team at the Department of Software Engineering,
> University of Szeged, Hungary, and we got interested in speeding up the
> JavaScript engine of WebKit. We would be happy to use our compiler
> background for the benefit of the project.
> 
> http://gcc.gnu.org/projects/cfo.html
> http://www.inf.u-szeged.hu/symbian-gcc/
> http://www.inf.u-szeged.hu/gcc-arm/
> http://www.inf.u-szeged.hu/csibe/
> 
> We have compiled a small list of enhancement possibilities, see below.
> Please consider it as the view of an outsider.
> 
> ---
> 1) Optimizing the AST
>   a) either during AST building
>   b) or the already built, complete AST, possibly in a background thread.
> 
> Comment: The execution model of the JS engine is quite simple. It simply
> builds an AST from the source and executes it. Thus, there are no CFG,
> basic blocks, use-definition chains, etc., which are common in
> traditional optimizing compilers. This either makes the possible
> optimizations less powerful or requires significan effort to implement
> such analysis techniques.
> 
> 2) Optimizing the AST execution.
> 
> Comment: Not enough knowledge on the internals.
> 
> 3) JIT compiling the AST to another language.
>   a) JIT compilation to native code.
> 
> Comment: Furthermore, the engine is currently platform independent. This
> would require platform-specific code on a per platform basis.
> 
>   b) JIT compilation to Java bytecode or ActionScript bytecode.
> 
> Comment: Huge work. Currently available compiler implementations do not
> fit to the architecture of the JS engine.
> 
>   c) JIT compilation to a new intermediate language.
> 
> Comment: Is it a good idea to come up with yet-another-bytecode?
> Interesting: According to the homepage, there are plans to use a
> bytecode interpreter in the JS engine. However, it is not specified what
> kind of bytecode is meant: Java, ActionScript, or a new one?
> ---
> 
> So, this is our view. But before starting any work, we would like to
> hear the opinion of the developers. What do you think of the above? Did
> we left out something important? Do you think that we can contribute
> somehow?
> 
> Best regards,
> 
> Akos Kiss
> Department of Software Engineering, University of Szeged, Hungary
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